Merge branch 'master' into for-linus

25 files changed, 25745 insertions, 0 deletions

diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
new file mode 100644
index 0000000..c43ef48
--- /dev/null
+++ b/drivers/tty/Makefile
@@ -0,0 +1,11 @@
+obj-y				+= tty_io.o n_tty.o tty_ioctl.o tty_ldisc.o \
+				   tty_buffer.o tty_port.o tty_mutex.o
+obj-$(CONFIG_LEGACY_PTYS)	+= pty.o
+obj-$(CONFIG_UNIX98_PTYS)	+= pty.o
+obj-$(CONFIG_AUDIT)		+= tty_audit.o
+obj-$(CONFIG_MAGIC_SYSRQ)	+= sysrq.o
+obj-$(CONFIG_N_HDLC)		+= n_hdlc.o
+obj-$(CONFIG_N_GSM)		+= n_gsm.o
+obj-$(CONFIG_R3964)		+= n_r3964.o
+
+obj-y				+= vt/
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
new file mode 100644
index 0000000..81b4658
--- /dev/null
+++ b/drivers/tty/n_gsm.c
@@ -0,0 +1,2764 @@
+/*
+ * n_gsm.c GSM 0710 tty multiplexor
+ * Copyright (c) 2009/10 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *	* THIS IS A DEVELOPMENT SNAPSHOT IT IS NOT A FINAL RELEASE *
+ *
+ * TO DO:
+ *	Mostly done:	ioctls for setting modes/timing
+ *	Partly done: 	hooks so you can pull off frames to non tty devs
+ *	Restart DLCI 0 when it closes ?
+ *	Test basic encoding
+ *	Improve the tx engine
+ *	Resolve tx side locking by adding a queue_head and routing
+ *		all control traffic via it
+ *	General tidy/document
+ *	Review the locking/move to refcounts more (mux now moved to an
+ *		alloc/free model ready)
+ *	Use newest tty open/close port helpers and install hooks
+ *	What to do about power functions ?
+ *	Termios setting and negotiation
+ *	Do we need a 'which mux are you' ioctl to correlate mux and tty sets
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/ctype.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/bitops.h>
+#include <linux/file.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/tty_flip.h>
+#include <linux/tty_driver.h>
+#include <linux/serial.h>
+#include <linux/kfifo.h>
+#include <linux/skbuff.h>
+#include <linux/gsmmux.h>
+
+static int debug;
+module_param(debug, int, 0600);
+
+#define T1	(HZ/10)
+#define T2	(HZ/3)
+#define N2	3
+
+/* Use long timers for testing at low speed with debug on */
+#ifdef DEBUG_TIMING
+#define T1	HZ
+#define T2	(2 * HZ)
+#endif
+
+/* Semi-arbitary buffer size limits. 0710 is normally run with 32-64 byte
+   limits so this is plenty */
+#define MAX_MRU 512
+#define MAX_MTU 512
+
+/*
+ *	Each block of data we have queued to go out is in the form of
+ *	a gsm_msg which holds everything we need in a link layer independant
+ *	format
+ */
+
+struct gsm_msg {
+	struct gsm_msg *next;
+	u8 addr;		/* DLCI address + flags */
+	u8 ctrl;		/* Control byte + flags */
+	unsigned int len;	/* Length of data block (can be zero) */
+	unsigned char *data;	/* Points into buffer but not at the start */
+	unsigned char buffer[0];
+};
+
+/*
+ *	Each active data link has a gsm_dlci structure associated which ties
+ *	the link layer to an optional tty (if the tty side is open). To avoid
+ *	complexity right now these are only ever freed up when the mux is
+ *	shut down.
+ *
+ *	At the moment we don't free DLCI objects until the mux is torn down
+ *	this avoid object life time issues but might be worth review later.
+ */
+
+struct gsm_dlci {
+	struct gsm_mux *gsm;
+	int addr;
+	int state;
+#define DLCI_CLOSED		0
+#define DLCI_OPENING		1	/* Sending SABM not seen UA */
+#define DLCI_OPEN		2	/* SABM/UA complete */
+#define DLCI_CLOSING		3	/* Sending DISC not seen UA/DM */
+
+	/* Link layer */
+	spinlock_t lock;	/* Protects the internal state */
+	struct timer_list t1;	/* Retransmit timer for SABM and UA */
+	int retries;
+	/* Uplink tty if active */
+	struct tty_port port;	/* The tty bound to this DLCI if there is one */
+	struct kfifo *fifo;	/* Queue fifo for the DLCI */
+	struct kfifo _fifo;	/* For new fifo API porting only */
+	int adaption;		/* Adaption layer in use */
+	u32 modem_rx;		/* Our incoming virtual modem lines */
+	u32 modem_tx;		/* Our outgoing modem lines */
+	int dead;		/* Refuse re-open */
+	/* Flow control */
+	int throttled;		/* Private copy of throttle state */
+	int constipated;	/* Throttle status for outgoing */
+	/* Packetised I/O */
+	struct sk_buff *skb;	/* Frame being sent */
+	struct sk_buff_head skb_list;	/* Queued frames */
+	/* Data handling callback */
+	void (*data)(struct gsm_dlci *dlci, u8 *data, int len);
+};
+
+/* DLCI 0, 62/63 are special or reseved see gsmtty_open */
+
+#define NUM_DLCI		64
+
+/*
+ *	DLCI 0 is used to pass control blocks out of band of the data
+ *	flow (and with a higher link priority). One command can be outstanding
+ *	at a time and we use this structure to manage them. They are created
+ *	and destroyed by the user context, and updated by the receive paths
+ *	and timers
+ */
+
+struct gsm_control {
+	u8 cmd;		/* Command we are issuing */
+	u8 *data;	/* Data for the command in case we retransmit */
+	int len;	/* Length of block for retransmission */
+	int done;	/* Done flag */
+	int error;	/* Error if any */
+};
+
+/*
+ *	Each GSM mux we have is represented by this structure. If we are
+ *	operating as an ldisc then we use this structure as our ldisc
+ *	state. We need to sort out lifetimes and locking with respect
+ *	to the gsm mux array. For now we don't free DLCI objects that
+ *	have been instantiated until the mux itself is terminated.
+ *
+ *	To consider further: tty open versus mux shutdown.
+ */
+
+struct gsm_mux {
+	struct tty_struct *tty;		/* The tty our ldisc is bound to */
+	spinlock_t lock;
+
+	/* Events on the GSM channel */
+	wait_queue_head_t event;
+
+	/* Bits for GSM mode decoding */
+
+	/* Framing Layer */
+	unsigned char *buf;
+	int state;
+#define GSM_SEARCH		0
+#define GSM_START		1
+#define GSM_ADDRESS		2
+#define GSM_CONTROL		3
+#define GSM_LEN			4
+#define GSM_DATA		5
+#define GSM_FCS			6
+#define GSM_OVERRUN		7
+	unsigned int len;
+	unsigned int address;
+	unsigned int count;
+	int escape;
+	int encoding;
+	u8 control;
+	u8 fcs;
+	u8 *txframe;			/* TX framing buffer */
+
+	/* Methods for the receiver side */
+	void (*receive)(struct gsm_mux *gsm, u8 ch);
+	void (*error)(struct gsm_mux *gsm, u8 ch, u8 flag);
+	/* And transmit side */
+	int (*output)(struct gsm_mux *mux, u8 *data, int len);
+
+	/* Link Layer */
+	unsigned int mru;
+	unsigned int mtu;
+	int initiator;			/* Did we initiate connection */
+	int dead;			/* Has the mux been shut down */
+	struct gsm_dlci *dlci[NUM_DLCI];
+	int constipated;		/* Asked by remote to shut up */
+
+	spinlock_t tx_lock;
+	unsigned int tx_bytes;		/* TX data outstanding */
+#define TX_THRESH_HI		8192
+#define TX_THRESH_LO		2048
+	struct gsm_msg *tx_head;	/* Pending data packets */
+	struct gsm_msg *tx_tail;
+
+	/* Control messages */
+	struct timer_list t2_timer;	/* Retransmit timer for commands */
+	int cretries;			/* Command retry counter */
+	struct gsm_control *pending_cmd;/* Our current pending command */
+	spinlock_t control_lock;	/* Protects the pending command */
+
+	/* Configuration */
+	int adaption;		/* 1 or 2 supported */
+	u8 ftype;		/* UI or UIH */
+	int t1, t2;		/* Timers in 1/100th of a sec */
+	int n2;			/* Retry count */
+
+	/* Statistics (not currently exposed) */
+	unsigned long bad_fcs;
+	unsigned long malformed;
+	unsigned long io_error;
+	unsigned long bad_size;
+	unsigned long unsupported;
+};
+
+
+/*
+ *	Mux objects - needed so that we can translate a tty index into the
+ *	relevant mux and DLCI.
+ */
+
+#define MAX_MUX		4			/* 256 minors */
+static struct gsm_mux *gsm_mux[MAX_MUX];	/* GSM muxes */
+static spinlock_t gsm_mux_lock;
+
+/*
+ *	This section of the driver logic implements the GSM encodings
+ *	both the basic and the 'advanced'. Reliable transport is not
+ *	supported.
+ */
+
+#define CR			0x02
+#define EA			0x01
+#define	PF			0x10
+
+/* I is special: the rest are ..*/
+#define RR			0x01
+#define UI			0x03
+#define RNR			0x05
+#define REJ			0x09
+#define DM			0x0F
+#define SABM			0x2F
+#define DISC			0x43
+#define UA			0x63
+#define	UIH			0xEF
+
+/* Channel commands */
+#define CMD_NSC			0x09
+#define CMD_TEST		0x11
+#define CMD_PSC			0x21
+#define CMD_RLS			0x29
+#define CMD_FCOFF		0x31
+#define CMD_PN			0x41
+#define CMD_RPN			0x49
+#define CMD_FCON		0x51
+#define CMD_CLD			0x61
+#define CMD_SNC			0x69
+#define CMD_MSC			0x71
+
+/* Virtual modem bits */
+#define MDM_FC			0x01
+#define MDM_RTC			0x02
+#define MDM_RTR			0x04
+#define MDM_IC			0x20
+#define MDM_DV			0x40
+
+#define GSM0_SOF		0xF9
+#define GSM1_SOF 		0x7E
+#define GSM1_ESCAPE		0x7D
+#define GSM1_ESCAPE_BITS	0x20
+#define XON			0x11
+#define XOFF			0x13
+
+static const struct tty_port_operations gsm_port_ops;
+
+/*
+ *	CRC table for GSM 0710
+ */
+
+static const u8 gsm_fcs8[256] = {
+	0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75,
+	0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B,
+	0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69,
+	0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67,
+	0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D,
+	0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43,
+	0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51,
+	0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F,
+	0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05,
+	0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B,
+	0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19,
+	0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17,
+	0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D,
+	0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33,
+	0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21,
+	0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F,
+	0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95,
+	0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B,
+	0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89,
+	0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87,
+	0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD,
+	0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3,
+	0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1,
+	0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF,
+	0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5,
+	0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB,
+	0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9,
+	0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7,
+	0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD,
+	0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3,
+	0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1,
+	0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
+};
+
+#define INIT_FCS	0xFF
+#define GOOD_FCS	0xCF
+
+/**
+ *	gsm_fcs_add	-	update FCS
+ *	@fcs: Current FCS
+ *	@c: Next data
+ *
+ *	Update the FCS to include c. Uses the algorithm in the specification
+ *	notes.
+ */
+
+static inline u8 gsm_fcs_add(u8 fcs, u8 c)
+{
+	return gsm_fcs8[fcs ^ c];
+}
+
+/**
+ *	gsm_fcs_add_block	-	update FCS for a block
+ *	@fcs: Current FCS
+ *	@c: buffer of data
+ *	@len: length of buffer
+ *
+ *	Update the FCS to include c. Uses the algorithm in the specification
+ *	notes.
+ */
+
+static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len)
+{
+	while (len--)
+		fcs = gsm_fcs8[fcs ^ *c++];
+	return fcs;
+}
+
+/**
+ *	gsm_read_ea		-	read a byte into an EA
+ *	@val: variable holding value
+ *	c: byte going into the EA
+ *
+ *	Processes one byte of an EA. Updates the passed variable
+ *	and returns 1 if the EA is now completely read
+ */
+
+static int gsm_read_ea(unsigned int *val, u8 c)
+{
+	/* Add the next 7 bits into the value */
+	*val <<= 7;
+	*val |= c >> 1;
+	/* Was this the last byte of the EA 1 = yes*/
+	return c & EA;
+}
+
+/**
+ *	gsm_encode_modem	-	encode modem data bits
+ *	@dlci: DLCI to encode from
+ *
+ *	Returns the correct GSM encoded modem status bits (6 bit field) for
+ *	the current status of the DLCI and attached tty object
+ */
+
+static u8 gsm_encode_modem(const struct gsm_dlci *dlci)
+{
+	u8 modembits = 0;
+	/* FC is true flow control not modem bits */
+	if (dlci->throttled)
+		modembits |= MDM_FC;
+	if (dlci->modem_tx & TIOCM_DTR)
+		modembits |= MDM_RTC;
+	if (dlci->modem_tx & TIOCM_RTS)
+		modembits |= MDM_RTR;
+	if (dlci->modem_tx & TIOCM_RI)
+		modembits |= MDM_IC;
+	if (dlci->modem_tx & TIOCM_CD)
+		modembits |= MDM_DV;
+	return modembits;
+}
+
+/**
+ *	gsm_print_packet	-	display a frame for debug
+ *	@hdr: header to print before decode
+ *	@addr: address EA from the frame
+ *	@cr: C/R bit from the frame
+ *	@control: control including PF bit
+ *	@data: following data bytes
+ *	@dlen: length of data
+ *
+ *	Displays a packet in human readable format for debugging purposes. The
+ *	style is based on amateur radio LAP-B dump display.
+ */
+
+static void gsm_print_packet(const char *hdr, int addr, int cr,
+					u8 control, const u8 *data, int dlen)
+{
+	if (!(debug & 1))
+		return;
+
+	printk(KERN_INFO "%s %d) %c: ", hdr, addr, "RC"[cr]);
+
+	switch (control & ~PF) {
+	case SABM:
+		printk(KERN_CONT "SABM");
+		break;
+	case UA:
+		printk(KERN_CONT "UA");
+		break;
+	case DISC:
+		printk(KERN_CONT "DISC");
+		break;
+	case DM:
+		printk(KERN_CONT "DM");
+		break;
+	case UI:
+		printk(KERN_CONT "UI");
+		break;
+	case UIH:
+		printk(KERN_CONT "UIH");
+		break;
+	default:
+		if (!(control & 0x01)) {
+			printk(KERN_CONT "I N(S)%d N(R)%d",
+				(control & 0x0E) >> 1, (control & 0xE)>> 5);
+		} else switch (control & 0x0F) {
+		case RR:
+			printk("RR(%d)", (control & 0xE0) >> 5);
+			break;
+		case RNR:
+			printk("RNR(%d)", (control & 0xE0) >> 5);
+			break;
+		case REJ:
+			printk("REJ(%d)", (control & 0xE0) >> 5);
+			break;
+		default:
+			printk(KERN_CONT "[%02X]", control);
+		}
+	}
+
+	if (control & PF)
+		printk(KERN_CONT "(P)");
+	else
+		printk(KERN_CONT "(F)");
+
+	if (dlen) {
+		int ct = 0;
+		while (dlen--) {
+			if (ct % 8 == 0)
+				printk(KERN_CONT "\n    ");
+			printk(KERN_CONT "%02X ", *data++);
+			ct++;
+		}
+	}
+	printk(KERN_CONT "\n");
+}
+
+
+/*
+ *	Link level transmission side
+ */
+
+/**
+ *	gsm_stuff_packet	-	bytestuff a packet
+ *	@ibuf: input
+ *	@obuf: output
+ *	@len: length of input
+ *
+ *	Expand a buffer by bytestuffing it. The worst case size change
+ *	is doubling and the caller is responsible for handing out
+ *	suitable sized buffers.
+ */
+
+static int gsm_stuff_frame(const u8 *input, u8 *output, int len)
+{
+	int olen = 0;
+	while (len--) {
+		if (*input == GSM1_SOF || *input == GSM1_ESCAPE
+		    || *input == XON || *input == XOFF) {
+			*output++ = GSM1_ESCAPE;
+			*output++ = *input++ ^ GSM1_ESCAPE_BITS;
+			olen++;
+		} else
+			*output++ = *input++;
+		olen++;
+	}
+	return olen;
+}
+
+static void hex_packet(const unsigned char *p, int len)
+{
+	int i;
+	for (i = 0; i < len; i++) {
+		if (i && (i % 16) == 0)
+			printk("\n");
+		printk("%02X ", *p++);
+	}
+	printk("\n");
+}
+
+/**
+ *	gsm_send	-	send a control frame
+ *	@gsm: our GSM mux
+ *	@addr: address for control frame
+ *	@cr: command/response bit
+ *	@control:  control byte including PF bit
+ *
+ *	Format up and transmit a control frame. These do not go via the
+ *	queueing logic as they should be transmitted ahead of data when
+ *	they are needed.
+ *
+ *	FIXME: Lock versus data TX path
+ */
+
+static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
+{
+	int len;
+	u8 cbuf[10];
+	u8 ibuf[3];
+
+	switch (gsm->encoding) {
+	case 0:
+		cbuf[0] = GSM0_SOF;
+		cbuf[1] = (addr << 2) | (cr << 1) | EA;
+		cbuf[2] = control;
+		cbuf[3] = EA;	/* Length of data = 0 */
+		cbuf[4] = 0xFF - gsm_fcs_add_block(INIT_FCS, cbuf + 1, 3);
+		cbuf[5] = GSM0_SOF;
+		len = 6;
+		break;
+	case 1:
+	case 2:
+		/* Control frame + packing (but not frame stuffing) in mode 1 */
+		ibuf[0] = (addr << 2) | (cr << 1) | EA;
+		ibuf[1] = control;
+		ibuf[2] = 0xFF - gsm_fcs_add_block(INIT_FCS, ibuf, 2);
+		/* Stuffing may double the size worst case */
+		len = gsm_stuff_frame(ibuf, cbuf + 1, 3);
+		/* Now add the SOF markers */
+		cbuf[0] = GSM1_SOF;
+		cbuf[len + 1] = GSM1_SOF;
+		/* FIXME: we can omit the lead one in many cases */
+		len += 2;
+		break;
+	default:
+		WARN_ON(1);
+		return;
+	}
+	gsm->output(gsm, cbuf, len);
+	gsm_print_packet("-->", addr, cr, control, NULL, 0);
+}
+
+/**
+ *	gsm_response	-	send a control response
+ *	@gsm: our GSM mux
+ *	@addr: address for control frame
+ *	@control:  control byte including PF bit
+ *
+ *	Format up and transmit a link level response frame.
+ */
+
+static inline void gsm_response(struct gsm_mux *gsm, int addr, int control)
+{
+	gsm_send(gsm, addr, 0, control);
+}
+
+/**
+ *	gsm_command	-	send a control command
+ *	@gsm: our GSM mux
+ *	@addr: address for control frame
+ *	@control:  control byte including PF bit
+ *
+ *	Format up and transmit a link level command frame.
+ */
+
+static inline void gsm_command(struct gsm_mux *gsm, int addr, int control)
+{
+	gsm_send(gsm, addr, 1, control);
+}
+
+/* Data transmission */
+
+#define HDR_LEN		6	/* ADDR CTRL [LEN.2] DATA FCS */
+
+/**
+ *	gsm_data_alloc		-	allocate data frame
+ *	@gsm: GSM mux
+ *	@addr: DLCI address
+ *	@len: length excluding header and FCS
+ *	@ctrl: control byte
+ *
+ *	Allocate a new data buffer for sending frames with data. Space is left
+ *	at the front for header bytes but that is treated as an implementation
+ *	detail and not for the high level code to use
+ */
+
+static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len,
+								u8 ctrl)
+{
+	struct gsm_msg *m = kmalloc(sizeof(struct gsm_msg) + len + HDR_LEN,
+								GFP_ATOMIC);
+	if (m == NULL)
+		return NULL;
+	m->data = m->buffer + HDR_LEN - 1;	/* Allow for FCS */
+	m->len = len;
+	m->addr = addr;
+	m->ctrl = ctrl;
+	m->next = NULL;
+	return m;
+}
+
+/**
+ *	gsm_data_kick		-	poke the queue
+ *	@gsm: GSM Mux
+ *
+ *	The tty device has called us to indicate that room has appeared in
+ *	the transmit queue. Ram more data into the pipe if we have any
+ *
+ *	FIXME: lock against link layer control transmissions
+ */
+
+static void gsm_data_kick(struct gsm_mux *gsm)
+{
+	struct gsm_msg *msg = gsm->tx_head;
+	int len;
+	int skip_sof = 0;
+
+	/* FIXME: We need to apply this solely to data messages */
+	if (gsm->constipated)
+		return;
+
+	while (gsm->tx_head != NULL) {
+		msg = gsm->tx_head;
+		if (gsm->encoding != 0) {
+			gsm->txframe[0] = GSM1_SOF;
+			len = gsm_stuff_frame(msg->data,
+						gsm->txframe + 1, msg->len);
+			gsm->txframe[len + 1] = GSM1_SOF;
+			len += 2;
+		} else {
+			gsm->txframe[0] = GSM0_SOF;
+			memcpy(gsm->txframe + 1 , msg->data, msg->len);
+			gsm->txframe[msg->len + 1] = GSM0_SOF;
+			len = msg->len + 2;
+		}
+
+		if (debug & 4) {
+			printk("gsm_data_kick: \n");
+			hex_packet(gsm->txframe, len);
+		}
+
+		if (gsm->output(gsm, gsm->txframe + skip_sof,
+						len - skip_sof) < 0)
+			break;
+		/* FIXME: Can eliminate one SOF in many more cases */
+		gsm->tx_head = msg->next;
+		if (gsm->tx_head == NULL)
+			gsm->tx_tail = NULL;
+		gsm->tx_bytes -= msg->len;
+		kfree(msg);
+		/* For a burst of frames skip the extra SOF within the
+		   burst */
+		skip_sof = 1;
+	}
+}
+
+/**
+ *	__gsm_data_queue		-	queue a UI or UIH frame
+ *	@dlci: DLCI sending the data
+ *	@msg: message queued
+ *
+ *	Add data to the transmit queue and try and get stuff moving
+ *	out of the mux tty if not already doing so. The Caller must hold
+ *	the gsm tx lock.
+ */
+
+static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
+{
+	struct gsm_mux *gsm = dlci->gsm;
+	u8 *dp = msg->data;
+	u8 *fcs = dp + msg->len;
+
+	/* Fill in the header */
+	if (gsm->encoding == 0) {
+		if (msg->len < 128)
+			*--dp = (msg->len << 1) | EA;
+		else {
+			*--dp = ((msg->len & 127) << 1) | EA;
+			*--dp = (msg->len >> 6) & 0xfe;
+		}
+	}
+
+	*--dp = msg->ctrl;
+	if (gsm->initiator)
+		*--dp = (msg->addr << 2) | 2 | EA;
+	else
+		*--dp = (msg->addr << 2) | EA;
+	*fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp);
+	/* Ugly protocol layering violation */
+	if (msg->ctrl == UI || msg->ctrl == (UI|PF))
+		*fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len);
+	*fcs = 0xFF - *fcs;
+
+	gsm_print_packet("Q> ", msg->addr, gsm->initiator, msg->ctrl,
+							msg->data, msg->len);
+
+	/* Move the header back and adjust the length, also allow for the FCS
+	   now tacked on the end */
+	msg->len += (msg->data - dp) + 1;
+	msg->data = dp;
+
+	/* Add to the actual output queue */
+	if (gsm->tx_tail)
+		gsm->tx_tail->next = msg;
+	else
+		gsm->tx_head = msg;
+	gsm->tx_tail = msg;
+	gsm->tx_bytes += msg->len;
+	gsm_data_kick(gsm);
+}
+
+/**
+ *	gsm_data_queue		-	queue a UI or UIH frame
+ *	@dlci: DLCI sending the data
+ *	@msg: message queued
+ *
+ *	Add data to the transmit queue and try and get stuff moving
+ *	out of the mux tty if not already doing so. Take the
+ *	the gsm tx lock and dlci lock.
+ */
+
+static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
+	__gsm_data_queue(dlci, msg);
+	spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
+}
+
+/**
+ *	gsm_dlci_data_output	-	try and push data out of a DLCI
+ *	@gsm: mux
+ *	@dlci: the DLCI to pull data from
+ *
+ *	Pull data from a DLCI and send it into the transmit queue if there
+ *	is data. Keep to the MRU of the mux. This path handles the usual tty
+ *	interface which is a byte stream with optional modem data.
+ *
+ *	Caller must hold the tx_lock of the mux.
+ */
+
+static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
+{
+	struct gsm_msg *msg;
+	u8 *dp;
+	int len, size;
+	int h = dlci->adaption - 1;
+
+	len = kfifo_len(dlci->fifo);
+	if (len == 0)
+		return 0;
+
+	/* MTU/MRU count only the data bits */
+	if (len > gsm->mtu)
+		len = gsm->mtu;
+
+	size = len + h;
+
+	msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype);
+	/* FIXME: need a timer or something to kick this so it can't
+	   get stuck with no work outstanding and no buffer free */
+	if (msg == NULL)
+		return -ENOMEM;
+	dp = msg->data;
+	switch (dlci->adaption) {
+	case 1:	/* Unstructured */
+		break;
+	case 2:	/* Unstructed with modem bits. Always one byte as we never
+		   send inline break data */
+		*dp += gsm_encode_modem(dlci);
+		len--;
+		break;
+	}
+	WARN_ON(kfifo_out_locked(dlci->fifo, dp , len, &dlci->lock) != len);
+	__gsm_data_queue(dlci, msg);
+	/* Bytes of data we used up */
+	return size;
+}
+
+/**
+ *	gsm_dlci_data_output_framed  -	try and push data out of a DLCI
+ *	@gsm: mux
+ *	@dlci: the DLCI to pull data from
+ *
+ *	Pull data from a DLCI and send it into the transmit queue if there
+ *	is data. Keep to the MRU of the mux. This path handles framed data
+ *	queued as skbuffs to the DLCI.
+ *
+ *	Caller must hold the tx_lock of the mux.
+ */
+
+static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
+						struct gsm_dlci *dlci)
+{
+	struct gsm_msg *msg;
+	u8 *dp;
+	int len, size;
+	int last = 0, first = 0;
+	int overhead = 0;
+
+	/* One byte per frame is used for B/F flags */
+	if (dlci->adaption == 4)
+		overhead = 1;
+
+	/* dlci->skb is locked by tx_lock */
+	if (dlci->skb == NULL) {
+		dlci->skb = skb_dequeue(&dlci->skb_list);
+		if (dlci->skb == NULL)
+			return 0;
+		first = 1;
+	}
+	len = dlci->skb->len + overhead;
+
+	/* MTU/MRU count only the data bits */
+	if (len > gsm->mtu) {
+		if (dlci->adaption == 3) {
+			/* Over long frame, bin it */
+			kfree_skb(dlci->skb);
+			dlci->skb = NULL;
+			return 0;
+		}
+		len = gsm->mtu;
+	} else
+		last = 1;
+
+	size = len + overhead;
+	msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype);
+
+	/* FIXME: need a timer or something to kick this so it can't
+	   get stuck with no work outstanding and no buffer free */
+	if (msg == NULL)
+		return -ENOMEM;
+	dp = msg->data;
+
+	if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */
+		/* Flag byte to carry the start/end info */
+		*dp++ = last << 7 | first << 6 | 1;	/* EA */
+		len--;
+	}
+	memcpy(dp, skb_pull(dlci->skb, len), len);
+	__gsm_data_queue(dlci, msg);
+	if (last)
+		dlci->skb = NULL;
+	return size;
+}
+
+/**
+ *	gsm_dlci_data_sweep		-	look for data to send
+ *	@gsm: the GSM mux
+ *
+ *	Sweep the GSM mux channels in priority order looking for ones with
+ *	data to send. We could do with optimising this scan a bit. We aim
+ *	to fill the queue totally or up to TX_THRESH_HI bytes. Once we hit
+ *	TX_THRESH_LO we get called again
+ *
+ *	FIXME: We should round robin between groups and in theory you can
+ *	renegotiate DLCI priorities with optional stuff. Needs optimising.
+ */
+
+static void gsm_dlci_data_sweep(struct gsm_mux *gsm)
+{
+	int len;
+	/* Priority ordering: We should do priority with RR of the groups */
+	int i = 1;
+
+	while (i < NUM_DLCI) {
+		struct gsm_dlci *dlci;
+
+		if (gsm->tx_bytes > TX_THRESH_HI)
+			break;
+		dlci = gsm->dlci[i];
+		if (dlci == NULL || dlci->constipated) {
+			i++;
+			continue;
+		}
+		if (dlci->adaption < 3)
+			len = gsm_dlci_data_output(gsm, dlci);
+		else
+			len = gsm_dlci_data_output_framed(gsm, dlci);
+		if (len < 0)
+			break;
+		/* DLCI empty - try the next */
+		if (len == 0)
+			i++;
+	}
+}
+
+/**
+ *	gsm_dlci_data_kick	-	transmit if possible
+ *	@dlci: DLCI to kick
+ *
+ *	Transmit data from this DLCI if the queue is empty. We can't rely on
+ *	a tty wakeup except when we filled the pipe so we need to fire off
+ *	new data ourselves in other cases.
+ */
+
+static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
+	/* If we have nothing running then we need to fire up */
+	if (dlci->gsm->tx_bytes == 0)
+		gsm_dlci_data_output(dlci->gsm, dlci);
+	else if (dlci->gsm->tx_bytes < TX_THRESH_LO)
+		gsm_dlci_data_sweep(dlci->gsm);
+	spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
+}
+
+/*
+ *	Control message processing
+ */
+
+
+/**
+ *	gsm_control_reply	-	send a response frame to a control
+ *	@gsm: gsm channel
+ *	@cmd: the command to use
+ *	@data: data to follow encoded info
+ *	@dlen: length of data
+ *
+ *	Encode up and queue a UI/UIH frame containing our response.
+ */
+
+static void gsm_control_reply(struct gsm_mux *gsm, int cmd, u8 *data,
+					int dlen)
+{
+	struct gsm_msg *msg;
+	msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype);
+	msg->data[0] = (cmd & 0xFE) << 1 | EA;	/* Clear C/R */
+	msg->data[1] = (dlen << 1) | EA;
+	memcpy(msg->data + 2, data, dlen);
+	gsm_data_queue(gsm->dlci[0], msg);
+}
+
+/**
+ *	gsm_process_modem	-	process received modem status
+ *	@tty: virtual tty bound to the DLCI
+ *	@dlci: DLCI to affect
+ *	@modem: modem bits (full EA)
+ *
+ *	Used when a modem control message or line state inline in adaption
+ *	layer 2 is processed. Sort out the local modem state and throttles
+ */
+
+static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci,
+							u32 modem)
+{
+	int  mlines = 0;
+	u8 brk = modem >> 6;
+
+	/* Flow control/ready to communicate */
+	if (modem & MDM_FC) {
+		/* Need to throttle our output on this device */
+		dlci->constipated = 1;
+	}
+	if (modem & MDM_RTC) {
+		mlines |= TIOCM_DSR | TIOCM_DTR;
+		dlci->constipated = 0;
+		gsm_dlci_data_kick(dlci);
+	}
+	/* Map modem bits */
+	if (modem & MDM_RTR)
+		mlines |= TIOCM_RTS | TIOCM_CTS;
+	if (modem & MDM_IC)
+		mlines |= TIOCM_RI;
+	if (modem & MDM_DV)
+		mlines |= TIOCM_CD;
+
+	/* Carrier drop -> hangup */
+	if (tty) {
+		if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD))
+			if (!(tty->termios->c_cflag & CLOCAL))
+				tty_hangup(tty);
+		if (brk & 0x01)
+			tty_insert_flip_char(tty, 0, TTY_BREAK);
+	}
+	dlci->modem_rx = mlines;
+}
+
+/**
+ *	gsm_control_modem	-	modem status received
+ *	@gsm: GSM channel
+ *	@data: data following command
+ *	@clen: command length
+ *
+ *	We have received a modem status control message. This is used by
+ *	the GSM mux protocol to pass virtual modem line status and optionally
+ *	to indicate break signals. Unpack it, convert to Linux representation
+ *	and if need be stuff a break message down the tty.
+ */
+
+static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen)
+{
+	unsigned int addr = 0;
+	unsigned int modem = 0;
+	struct gsm_dlci *dlci;
+	int len = clen;
+	u8 *dp = data;
+	struct tty_struct *tty;
+
+	while (gsm_read_ea(&addr, *dp++) == 0) {
+		len--;
+		if (len == 0)
+			return;
+	}
+	/* Must be at least one byte following the EA */
+	len--;
+	if (len <= 0)
+		return;
+
+	addr >>= 1;
+	/* Closed port, or invalid ? */
+	if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL)
+		return;
+	dlci = gsm->dlci[addr];
+
+	while (gsm_read_ea(&modem, *dp++) == 0) {
+		len--;
+		if (len == 0)
+			return;
+	}
+	tty = tty_port_tty_get(&dlci->port);
+	gsm_process_modem(tty, dlci, modem);
+	if (tty) {
+		tty_wakeup(tty);
+		tty_kref_put(tty);
+	}
+	gsm_control_reply(gsm, CMD_MSC, data, clen);
+}
+
+/**
+ *	gsm_control_rls		-	remote line status
+ *	@gsm: GSM channel
+ *	@data: data bytes
+ *	@clen: data length
+ *
+ *	The modem sends us a two byte message on the control channel whenever
+ *	it wishes to send us an error state from the virtual link. Stuff
+ *	this into the uplink tty if present
+ */
+
+static void gsm_control_rls(struct gsm_mux *gsm, u8 *data, int clen)
+{
+	struct tty_struct *tty;
+	unsigned int addr = 0 ;
+	u8 bits;
+	int len = clen;
+	u8 *dp = data;
+
+	while (gsm_read_ea(&addr, *dp++) == 0) {
+		len--;
+		if (len == 0)
+			return;
+	}
+	/* Must be at least one byte following ea */
+	len--;
+	if (len <= 0)
+		return;
+	addr >>= 1;
+	/* Closed port, or invalid ? */
+	if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL)
+		return;
+	/* No error ? */
+	bits = *dp;
+	if ((bits & 1) == 0)
+		return;
+	/* See if we have an uplink tty */
+	tty = tty_port_tty_get(&gsm->dlci[addr]->port);
+
+	if (tty) {
+		if (bits & 2)
+			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		if (bits & 4)
+			tty_insert_flip_char(tty, 0, TTY_PARITY);
+		if (bits & 8)
+			tty_insert_flip_char(tty, 0, TTY_FRAME);
+		tty_flip_buffer_push(tty);
+		tty_kref_put(tty);
+	}
+	gsm_control_reply(gsm, CMD_RLS, data, clen);
+}
+
+static void gsm_dlci_begin_close(struct gsm_dlci *dlci);
+
+/**
+ *	gsm_control_message	-	DLCI 0 control processing
+ *	@gsm: our GSM mux
+ *	@command:  the command EA
+ *	@data: data beyond the command/length EAs
+ *	@clen: length
+ *
+ *	Input processor for control messages from the other end of the link.
+ *	Processes the incoming request and queues a response frame or an
+ *	NSC response if not supported
+ */
+
+static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
+							u8 *data, int clen)
+{
+	u8 buf[1];
+	switch (command) {
+	case CMD_CLD: {
+		struct gsm_dlci *dlci = gsm->dlci[0];
+		/* Modem wishes to close down */
+		if (dlci) {
+			dlci->dead = 1;
+			gsm->dead = 1;
+			gsm_dlci_begin_close(dlci);
+		}
+		}
+		break;
+	case CMD_TEST:
+		/* Modem wishes to test, reply with the data */
+		gsm_control_reply(gsm, CMD_TEST, data, clen);
+		break;
+	case CMD_FCON:
+		/* Modem wants us to STFU */
+		gsm->constipated = 1;
+		gsm_control_reply(gsm, CMD_FCON, NULL, 0);
+		break;
+	case CMD_FCOFF:
+		/* Modem can accept data again */
+		gsm->constipated = 0;
+		gsm_control_reply(gsm, CMD_FCOFF, NULL, 0);
+		/* Kick the link in case it is idling */
+		gsm_data_kick(gsm);
+		break;
+	case CMD_MSC:
+		/* Out of band modem line change indicator for a DLCI */
+		gsm_control_modem(gsm, data, clen);
+		break;
+	case CMD_RLS:
+		/* Out of band error reception for a DLCI */
+		gsm_control_rls(gsm, data, clen);
+		break;
+	case CMD_PSC:
+		/* Modem wishes to enter power saving state */
+		gsm_control_reply(gsm, CMD_PSC, NULL, 0);
+		break;
+		/* Optional unsupported commands */
+	case CMD_PN:	/* Parameter negotiation */
+	case CMD_RPN:	/* Remote port negotation */
+	case CMD_SNC:	/* Service negotation command */
+	default:
+		/* Reply to bad commands with an NSC */
+		buf[0] = command;
+		gsm_control_reply(gsm, CMD_NSC, buf, 1);
+		break;
+	}
+}
+
+/**
+ *	gsm_control_response	-	process a response to our control
+ *	@gsm: our GSM mux
+ *	@command: the command (response) EA
+ *	@data: data beyond the command/length EA
+ *	@clen: length
+ *
+ *	Process a response to an outstanding command. We only allow a single
+ *	control message in flight so this is fairly easy. All the clean up
+ *	is done by the caller, we just update the fields, flag it as done
+ *	and return
+ */
+
+static void gsm_control_response(struct gsm_mux *gsm, unsigned int command,
+							u8 *data, int clen)
+{
+	struct gsm_control *ctrl;
+	unsigned long flags;
+
+	spin_lock_irqsave(&gsm->control_lock, flags);
+
+	ctrl = gsm->pending_cmd;
+	/* Does the reply match our command */
+	command |= 1;
+	if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) {
+		/* Our command was replied to, kill the retry timer */
+		del_timer(&gsm->t2_timer);
+		gsm->pending_cmd = NULL;
+		/* Rejected by the other end */
+		if (command == CMD_NSC)
+			ctrl->error = -EOPNOTSUPP;
+		ctrl->done = 1;
+		wake_up(&gsm->event);
+	}
+	spin_unlock_irqrestore(&gsm->control_lock, flags);
+}
+
+/**
+ *	gsm_control_transmit 	-	send control packet
+ *	@gsm: gsm mux
+ *	@ctrl: frame to send
+ *
+ *	Send out a pending control command (called under control lock)
+ */
+
+static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl)
+{
+	struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 1,
+							gsm->ftype|PF);
+	if (msg == NULL)
+		return;
+	msg->data[0] = (ctrl->cmd << 1) | 2 | EA;	/* command */
+	memcpy(msg->data + 1, ctrl->data, ctrl->len);
+	gsm_data_queue(gsm->dlci[0], msg);
+}
+
+/**
+ *	gsm_control_retransmit	-	retransmit a control frame
+ *	@data: pointer to our gsm object
+ *
+ *	Called off the T2 timer expiry in order to retransmit control frames
+ *	that have been lost in the system somewhere. The control_lock protects
+ *	us from colliding with another sender or a receive completion event.
+ *	In that situation the timer may still occur in a small window but
+ *	gsm->pending_cmd will be NULL and we just let the timer expire.
+ */
+
+static void gsm_control_retransmit(unsigned long data)
+{
+	struct gsm_mux *gsm = (struct gsm_mux *)data;
+	struct gsm_control *ctrl;
+	unsigned long flags;
+	spin_lock_irqsave(&gsm->control_lock, flags);
+	ctrl = gsm->pending_cmd;
+	if (ctrl) {
+		gsm->cretries--;
+		if (gsm->cretries == 0) {
+			gsm->pending_cmd = NULL;
+			ctrl->error = -ETIMEDOUT;
+			ctrl->done = 1;
+			spin_unlock_irqrestore(&gsm->control_lock, flags);
+			wake_up(&gsm->event);
+			return;
+		}
+		gsm_control_transmit(gsm, ctrl);
+		mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
+	}
+	spin_unlock_irqrestore(&gsm->control_lock, flags);
+}
+
+/**
+ *	gsm_control_send	-	send a control frame on DLCI 0
+ *	@gsm: the GSM channel
+ *	@command: command  to send including CR bit
+ *	@data: bytes of data (must be kmalloced)
+ *	@len: length of the block to send
+ *
+ *	Queue and dispatch a control command. Only one command can be
+ *	active at a time. In theory more can be outstanding but the matching
+ *	gets really complicated so for now stick to one outstanding.
+ */
+
+static struct gsm_control *gsm_control_send(struct gsm_mux *gsm,
+		unsigned int command, u8 *data, int clen)
+{
+	struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control),
+						GFP_KERNEL);
+	unsigned long flags;
+	if (ctrl == NULL)
+		return NULL;
+retry:
+	wait_event(gsm->event, gsm->pending_cmd == NULL);
+	spin_lock_irqsave(&gsm->control_lock, flags);
+	if (gsm->pending_cmd != NULL) {
+		spin_unlock_irqrestore(&gsm->control_lock, flags);
+		goto retry;
+	}
+	ctrl->cmd = command;
+	ctrl->data = data;
+	ctrl->len = clen;
+	gsm->pending_cmd = ctrl;
+	gsm->cretries = gsm->n2;
+	mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
+	gsm_control_transmit(gsm, ctrl);
+	spin_unlock_irqrestore(&gsm->control_lock, flags);
+	return ctrl;
+}
+
+/**
+ *	gsm_control_wait	-	wait for a control to finish
+ *	@gsm: GSM mux
+ *	@control: control we are waiting on
+ *
+ *	Waits for the control to complete or time out. Frees any used
+ *	resources and returns 0 for success, or an error if the remote
+ *	rejected or ignored the request.
+ */
+
+static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control)
+{
+	int err;
+	wait_event(gsm->event, control->done == 1);
+	err = control->error;
+	kfree(control);
+	return err;
+}
+
+
+/*
+ *	DLCI level handling: Needs krefs
+ */
+
+/*
+ *	State transitions and timers
+ */
+
+/**
+ *	gsm_dlci_close		-	a DLCI has closed
+ *	@dlci: DLCI that closed
+ *
+ *	Perform processing when moving a DLCI into closed state. If there
+ *	is an attached tty this is hung up
+ */
+
+static void gsm_dlci_close(struct gsm_dlci *dlci)
+{
+	del_timer(&dlci->t1);
+	if (debug & 8)
+		printk("DLCI %d goes closed.\n", dlci->addr);
+	dlci->state = DLCI_CLOSED;
+	if (dlci->addr != 0) {
+		struct tty_struct  *tty = tty_port_tty_get(&dlci->port);
+		if (tty) {
+			tty_hangup(tty);
+			tty_kref_put(tty);
+		}
+		kfifo_reset(dlci->fifo);
+	} else
+		dlci->gsm->dead = 1;
+	wake_up(&dlci->gsm->event);
+	/* A DLCI 0 close is a MUX termination so we need to kick that
+	   back to userspace somehow */
+}
+
+/**
+ *	gsm_dlci_open		-	a DLCI has opened
+ *	@dlci: DLCI that opened
+ *
+ *	Perform processing when moving a DLCI into open state.
+ */
+
+static void gsm_dlci_open(struct gsm_dlci *dlci)
+{
+	/* Note that SABM UA .. SABM UA first UA lost can mean that we go
+	   open -> open */
+	del_timer(&dlci->t1);
+	/* This will let a tty open continue */
+	dlci->state = DLCI_OPEN;
+	if (debug & 8)
+		printk("DLCI %d goes open.\n", dlci->addr);
+	wake_up(&dlci->gsm->event);
+}
+
+/**
+ *	gsm_dlci_t1		-	T1 timer expiry
+ *	@dlci: DLCI that opened
+ *
+ *	The T1 timer handles retransmits of control frames (essentially of
+ *	SABM and DISC). We resend the command until the retry count runs out
+ *	in which case an opening port goes back to closed and a closing port
+ *	is simply put into closed state (any further frames from the other
+ *	end will get a DM response)
+ */
+
+static void gsm_dlci_t1(unsigned long data)
+{
+	struct gsm_dlci *dlci = (struct gsm_dlci *)data;
+	struct gsm_mux *gsm = dlci->gsm;
+
+	switch (dlci->state) {
+	case DLCI_OPENING:
+		dlci->retries--;
+		if (dlci->retries) {
+			gsm_command(dlci->gsm, dlci->addr, SABM|PF);
+			mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+		} else
+			gsm_dlci_close(dlci);
+		break;
+	case DLCI_CLOSING:
+		dlci->retries--;
+		if (dlci->retries) {
+			gsm_command(dlci->gsm, dlci->addr, DISC|PF);
+			mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+		} else
+			gsm_dlci_close(dlci);
+		break;
+	}
+}
+
+/**
+ *	gsm_dlci_begin_open	-	start channel open procedure
+ *	@dlci: DLCI to open
+ *
+ *	Commence opening a DLCI from the Linux side. We issue SABM messages
+ *	to the modem which should then reply with a UA, at which point we
+ *	will move into open state. Opening is done asynchronously with retry
+ *	running off timers and the responses.
+ */
+
+static void gsm_dlci_begin_open(struct gsm_dlci *dlci)
+{
+	struct gsm_mux *gsm = dlci->gsm;
+	if (dlci->state == DLCI_OPEN || dlci->state == DLCI_OPENING)
+		return;
+	dlci->retries = gsm->n2;
+	dlci->state = DLCI_OPENING;
+	gsm_command(dlci->gsm, dlci->addr, SABM|PF);
+	mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+}
+
+/**
+ *	gsm_dlci_begin_close	-	start channel open procedure
+ *	@dlci: DLCI to open
+ *
+ *	Commence closing a DLCI from the Linux side. We issue DISC messages
+ *	to the modem which should then reply with a UA, at which point we
+ *	will move into closed state. Closing is done asynchronously with retry
+ *	off timers. We may also receive a DM reply from the other end which
+ *	indicates the channel was already closed.
+ */
+
+static void gsm_dlci_begin_close(struct gsm_dlci *dlci)
+{
+	struct gsm_mux *gsm = dlci->gsm;
+	if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING)
+		return;
+	dlci->retries = gsm->n2;
+	dlci->state = DLCI_CLOSING;
+	gsm_command(dlci->gsm, dlci->addr, DISC|PF);
+	mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+}
+
+/**
+ *	gsm_dlci_data		-	data arrived
+ *	@dlci: channel
+ *	@data: block of bytes received
+ *	@len: length of received block
+ *
+ *	A UI or UIH frame has arrived which contains data for a channel
+ *	other than the control channel. If the relevant virtual tty is
+ *	open we shovel the bits down it, if not we drop them.
+ */
+
+static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int len)
+{
+	/* krefs .. */
+	struct tty_port *port = &dlci->port;
+	struct tty_struct *tty = tty_port_tty_get(port);
+	unsigned int modem = 0;
+
+	if (debug & 16)
+		printk("%d bytes for tty %p\n", len, tty);
+	if (tty) {
+		switch (dlci->adaption)  {
+			/* Unsupported types */
+			/* Packetised interruptible data */
+			case 4:
+				break;
+			/* Packetised uininterruptible voice/data */
+			case 3:
+				break;
+			/* Asynchronous serial with line state in each frame */
+			case 2:
+				while (gsm_read_ea(&modem, *data++) == 0) {
+					len--;
+					if (len == 0)
+						return;
+				}
+				gsm_process_modem(tty, dlci, modem);
+			/* Line state will go via DLCI 0 controls only */
+			case 1:
+			default:
+				tty_insert_flip_string(tty, data, len);
+				tty_flip_buffer_push(tty);
+		}
+		tty_kref_put(tty);
+	}
+}
+
+/**
+ *	gsm_dlci_control	-	data arrived on control channel
+ *	@dlci: channel
+ *	@data: block of bytes received
+ *	@len: length of received block
+ *
+ *	A UI or UIH frame has arrived which contains data for DLCI 0 the
+ *	control channel. This should contain a command EA followed by
+ *	control data bytes. The command EA contains a command/response bit
+ *	and we divide up the work accordingly.
+ */
+
+static void gsm_dlci_command(struct gsm_dlci *dlci, u8 *data, int len)
+{
+	/* See what command is involved */
+	unsigned int command = 0;
+	while (len-- > 0) {
+		if (gsm_read_ea(&command, *data++) == 1) {
+			int clen = *data++;
+			len--;
+			/* FIXME: this is properly an EA */
+			clen >>= 1;
+			/* Malformed command ? */
+			if (clen > len)
+				return;
+			if (command & 1)
+				gsm_control_message(dlci->gsm, command,
+								data, clen);
+			else
+				gsm_control_response(dlci->gsm, command,
+								data, clen);
+			return;
+		}
+	}
+}
+
+/*
+ *	Allocate/Free DLCI channels
+ */
+
+/**
+ *	gsm_dlci_alloc		-	allocate a DLCI
+ *	@gsm: GSM mux
+ *	@addr: address of the DLCI
+ *
+ *	Allocate and install a new DLCI object into the GSM mux.
+ *
+ *	FIXME: review locking races
+ */
+
+static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr)
+{
+	struct gsm_dlci *dlci = kzalloc(sizeof(struct gsm_dlci), GFP_ATOMIC);
+	if (dlci == NULL)
+		return NULL;
+	spin_lock_init(&dlci->lock);
+	dlci->fifo = &dlci->_fifo;
+	if (kfifo_alloc(&dlci->_fifo, 4096, GFP_KERNEL) < 0) {
+		kfree(dlci);
+		return NULL;
+	}
+
+	skb_queue_head_init(&dlci->skb_list);
+	init_timer(&dlci->t1);
+	dlci->t1.function = gsm_dlci_t1;
+	dlci->t1.data = (unsigned long)dlci;
+	tty_port_init(&dlci->port);
+	dlci->port.ops = &gsm_port_ops;
+	dlci->gsm = gsm;
+	dlci->addr = addr;
+	dlci->adaption = gsm->adaption;
+	dlci->state = DLCI_CLOSED;
+	if (addr)
+		dlci->data = gsm_dlci_data;
+	else
+		dlci->data = gsm_dlci_command;
+	gsm->dlci[addr] = dlci;
+	return dlci;
+}
+
+/**
+ *	gsm_dlci_free		-	release DLCI
+ *	@dlci: DLCI to destroy
+ *
+ *	Free up a DLCI. Currently to keep the lifetime rules sane we only
+ *	clean up DLCI objects when the MUX closes rather than as the port
+ *	is closed down on both the tty and mux levels.
+ *
+ *	Can sleep.
+ */
+static void gsm_dlci_free(struct gsm_dlci *dlci)
+{
+	struct tty_struct *tty = tty_port_tty_get(&dlci->port);
+	if (tty) {
+		tty_vhangup(tty);
+		tty_kref_put(tty);
+	}
+	del_timer_sync(&dlci->t1);
+	dlci->gsm->dlci[dlci->addr] = NULL;
+	kfifo_free(dlci->fifo);
+	kfree(dlci);
+}
+
+
+/*
+ *	LAPBish link layer logic
+ */
+
+/**
+ *	gsm_queue		-	a GSM frame is ready to process
+ *	@gsm: pointer to our gsm mux
+ *
+ *	At this point in time a frame has arrived and been demangled from
+ *	the line encoding. All the differences between the encodings have
+ *	been handled below us and the frame is unpacked into the structures.
+ *	The fcs holds the header FCS but any data FCS must be added here.
+ */
+
+static void gsm_queue(struct gsm_mux *gsm)
+{
+	struct gsm_dlci *dlci;
+	u8 cr;
+	int address;
+	/* We have to sneak a look at the packet body to do the FCS.
+	   A somewhat layering violation in the spec */
+
+	if ((gsm->control & ~PF) == UI)
+		gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len);
+	if (gsm->fcs != GOOD_FCS) {
+		gsm->bad_fcs++;
+		if (debug & 4)
+			printk("BAD FCS %02x\n", gsm->fcs);
+		return;
+	}
+	address = gsm->address >> 1;
+	if (address >= NUM_DLCI)
+		goto invalid;
+
+	cr = gsm->address & 1;		/* C/R bit */
+
+	gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len);
+
+	cr ^= 1 - gsm->initiator;	/* Flip so 1 always means command */
+	dlci = gsm->dlci[address];
+
+	switch (gsm->control) {
+	case SABM|PF:
+		if (cr == 0)
+			goto invalid;
+		if (dlci == NULL)
+			dlci = gsm_dlci_alloc(gsm, address);
+		if (dlci == NULL)
+			return;
+		if (dlci->dead)
+			gsm_response(gsm, address, DM);
+		else {
+			gsm_response(gsm, address, UA);
+			gsm_dlci_open(dlci);
+		}
+		break;
+	case DISC|PF:
+		if (cr == 0)
+			goto invalid;
+		if (dlci == NULL || dlci->state == DLCI_CLOSED) {
+			gsm_response(gsm, address, DM);
+			return;
+		}
+		/* Real close complete */
+		gsm_response(gsm, address, UA);
+		gsm_dlci_close(dlci);
+		break;
+	case UA:
+	case UA|PF:
+		if (cr == 0 || dlci == NULL)
+			break;
+		switch (dlci->state) {
+		case DLCI_CLOSING:
+			gsm_dlci_close(dlci);
+			break;
+		case DLCI_OPENING:
+			gsm_dlci_open(dlci);
+			break;
+		}
+		break;
+	case DM:	/* DM can be valid unsolicited */
+	case DM|PF:
+		if (cr)
+			goto invalid;
+		if (dlci == NULL)
+			return;
+		gsm_dlci_close(dlci);
+		break;
+	case UI:
+	case UI|PF:
+	case UIH:
+	case UIH|PF:
+#if 0
+		if (cr)
+			goto invalid;
+#endif
+		if (dlci == NULL || dlci->state != DLCI_OPEN) {
+			gsm_command(gsm, address, DM|PF);
+			return;
+		}
+		dlci->data(dlci, gsm->buf, gsm->len);
+		break;
+	default:
+		goto invalid;
+	}
+	return;
+invalid:
+	gsm->malformed++;
+	return;
+}
+
+
+/**
+ *	gsm0_receive	-	perform processing for non-transparency
+ *	@gsm: gsm data for this ldisc instance
+ *	@c: character
+ *
+ *	Receive bytes in gsm mode 0
+ */
+
+static void gsm0_receive(struct gsm_mux *gsm, unsigned char c)
+{
+	switch (gsm->state) {
+	case GSM_SEARCH:	/* SOF marker */
+		if (c == GSM0_SOF) {
+			gsm->state = GSM_ADDRESS;
+			gsm->address = 0;
+			gsm->len = 0;
+			gsm->fcs = INIT_FCS;
+		}
+		break;		/* Address EA */
+	case GSM_ADDRESS:
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		if (gsm_read_ea(&gsm->address, c))
+			gsm->state = GSM_CONTROL;
+		break;
+	case GSM_CONTROL:	/* Control Byte */
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		gsm->control = c;
+		gsm->state = GSM_LEN;
+		break;
+	case GSM_LEN:		/* Length EA */
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		if (gsm_read_ea(&gsm->len, c)) {
+			if (gsm->len > gsm->mru) {
+				gsm->bad_size++;
+				gsm->state = GSM_SEARCH;
+				break;
+			}
+			gsm->count = 0;
+			gsm->state = GSM_DATA;
+		}
+		break;
+	case GSM_DATA:		/* Data */
+		gsm->buf[gsm->count++] = c;
+		if (gsm->count == gsm->len)
+			gsm->state = GSM_FCS;
+		break;
+	case GSM_FCS:		/* FCS follows the packet */
+		gsm->fcs = c;
+		gsm_queue(gsm);
+		/* And then back for the next frame */
+		gsm->state = GSM_SEARCH;
+		break;
+	}
+}
+
+/**
+ *	gsm0_receive	-	perform processing for non-transparency
+ *	@gsm: gsm data for this ldisc instance
+ *	@c: character
+ *
+ *	Receive bytes in mode 1 (Advanced option)
+ */
+
+static void gsm1_receive(struct gsm_mux *gsm, unsigned char c)
+{
+	if (c == GSM1_SOF) {
+		/* EOF is only valid in frame if we have got to the data state
+		   and received at least one byte (the FCS) */
+		if (gsm->state == GSM_DATA && gsm->count) {
+			/* Extract the FCS */
+			gsm->count--;
+			gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]);
+			gsm->len = gsm->count;
+			gsm_queue(gsm);
+			gsm->state  = GSM_START;
+			return;
+		}
+		/* Any partial frame was a runt so go back to start */
+		if (gsm->state != GSM_START) {
+			gsm->malformed++;
+			gsm->state = GSM_START;
+		}
+		/* A SOF in GSM_START means we are still reading idling or
+		   framing bytes */
+		return;
+	}
+
+	if (c == GSM1_ESCAPE) {
+		gsm->escape = 1;
+		return;
+	}
+
+	/* Only an unescaped SOF gets us out of GSM search */
+	if (gsm->state == GSM_SEARCH)
+		return;
+
+	if (gsm->escape) {
+		c ^= GSM1_ESCAPE_BITS;
+		gsm->escape = 0;
+	}
+	switch (gsm->state) {
+	case GSM_START:		/* First byte after SOF */
+		gsm->address = 0;
+		gsm->state = GSM_ADDRESS;
+		gsm->fcs = INIT_FCS;
+		/* Drop through */
+	case GSM_ADDRESS:	/* Address continuation */
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		if (gsm_read_ea(&gsm->address, c))
+			gsm->state = GSM_CONTROL;
+		break;
+	case GSM_CONTROL:	/* Control Byte */
+		gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+		gsm->control = c;
+		gsm->count = 0;
+		gsm->state = GSM_DATA;
+		break;
+	case GSM_DATA:		/* Data */
+		if (gsm->count > gsm->mru ) {	/* Allow one for the FCS */
+			gsm->state = GSM_OVERRUN;
+			gsm->bad_size++;
+		} else
+			gsm->buf[gsm->count++] = c;
+		break;
+	case GSM_OVERRUN:	/* Over-long - eg a dropped SOF */
+		break;
+	}
+}
+
+/**
+ *	gsm_error		-	handle tty error
+ *	@gsm: ldisc data
+ *	@data: byte received (may be invalid)
+ *	@flag: error received
+ *
+ *	Handle an error in the receipt of data for a frame. Currently we just
+ *	go back to hunting for a SOF.
+ *
+ *	FIXME: better diagnostics ?
+ */
+
+static void gsm_error(struct gsm_mux *gsm,
+				unsigned char data, unsigned char flag)
+{
+	gsm->state = GSM_SEARCH;
+	gsm->io_error++;
+}
+
+/**
+ *	gsm_cleanup_mux		-	generic GSM protocol cleanup
+ *	@gsm: our mux
+ *
+ *	Clean up the bits of the mux which are the same for all framing
+ *	protocols. Remove the mux from the mux table, stop all the timers
+ *	and then shut down each device hanging up the channels as we go.
+ */
+
+void gsm_cleanup_mux(struct gsm_mux *gsm)
+{
+	int i;
+	struct gsm_dlci *dlci = gsm->dlci[0];
+	struct gsm_msg *txq;
+
+	gsm->dead = 1;
+
+	spin_lock(&gsm_mux_lock);
+	for (i = 0; i < MAX_MUX; i++) {
+		if (gsm_mux[i] == gsm) {
+			gsm_mux[i] = NULL;
+			break;
+		}
+	}
+	spin_unlock(&gsm_mux_lock);
+	WARN_ON(i == MAX_MUX);
+
+	del_timer_sync(&gsm->t2_timer);
+	/* Now we are sure T2 has stopped */
+	if (dlci) {
+		dlci->dead = 1;
+		gsm_dlci_begin_close(dlci);
+		wait_event_interruptible(gsm->event,
+					dlci->state == DLCI_CLOSED);
+	}
+	/* Free up any link layer users */
+	for (i = 0; i < NUM_DLCI; i++)
+		if (gsm->dlci[i])
+			gsm_dlci_free(gsm->dlci[i]);
+	/* Now wipe the queues */
+	for (txq = gsm->tx_head; txq != NULL; txq = gsm->tx_head) {
+		gsm->tx_head = txq->next;
+		kfree(txq);
+	}
+	gsm->tx_tail = NULL;
+}
+EXPORT_SYMBOL_GPL(gsm_cleanup_mux);
+
+/**
+ *	gsm_activate_mux	-	generic GSM setup
+ *	@gsm: our mux
+ *
+ *	Set up the bits of the mux which are the same for all framing
+ *	protocols. Add the mux to the mux table so it can be opened and
+ *	finally kick off connecting to DLCI 0 on the modem.
+ */
+
+int gsm_activate_mux(struct gsm_mux *gsm)
+{
+	struct gsm_dlci *dlci;
+	int i = 0;
+
+	init_timer(&gsm->t2_timer);
+	gsm->t2_timer.function = gsm_control_retransmit;
+	gsm->t2_timer.data = (unsigned long)gsm;
+	init_waitqueue_head(&gsm->event);
+	spin_lock_init(&gsm->control_lock);
+	spin_lock_init(&gsm->tx_lock);
+
+	if (gsm->encoding == 0)
+		gsm->receive = gsm0_receive;
+	else
+		gsm->receive = gsm1_receive;
+	gsm->error = gsm_error;
+
+	spin_lock(&gsm_mux_lock);
+	for (i = 0; i < MAX_MUX; i++) {
+		if (gsm_mux[i] == NULL) {
+			gsm_mux[i] = gsm;
+			break;
+		}
+	}
+	spin_unlock(&gsm_mux_lock);
+	if (i == MAX_MUX)
+		return -EBUSY;
+
+	dlci = gsm_dlci_alloc(gsm, 0);
+	if (dlci == NULL)
+		return -ENOMEM;
+	gsm->dead = 0;		/* Tty opens are now permissible */
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gsm_activate_mux);
+
+/**
+ *	gsm_free_mux		-	free up a mux
+ *	@mux: mux to free
+ *
+ *	Dispose of allocated resources for a dead mux. No refcounting
+ *	at present so the mux must be truely dead.
+ */
+void gsm_free_mux(struct gsm_mux *gsm)
+{
+	kfree(gsm->txframe);
+	kfree(gsm->buf);
+	kfree(gsm);
+}
+EXPORT_SYMBOL_GPL(gsm_free_mux);
+
+/**
+ *	gsm_alloc_mux		-	allocate a mux
+ *
+ *	Creates a new mux ready for activation.
+ */
+
+struct gsm_mux *gsm_alloc_mux(void)
+{
+	struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL);
+	if (gsm == NULL)
+		return NULL;
+	gsm->buf = kmalloc(MAX_MRU + 1, GFP_KERNEL);
+	if (gsm->buf == NULL) {
+		kfree(gsm);
+		return NULL;
+	}
+	gsm->txframe = kmalloc(2 * MAX_MRU + 2, GFP_KERNEL);
+	if (gsm->txframe == NULL) {
+		kfree(gsm->buf);
+		kfree(gsm);
+		return NULL;
+	}
+	spin_lock_init(&gsm->lock);
+
+	gsm->t1 = T1;
+	gsm->t2 = T2;
+	gsm->n2 = N2;
+	gsm->ftype = UIH;
+	gsm->initiator = 0;
+	gsm->adaption = 1;
+	gsm->encoding = 1;
+	gsm->mru = 64;	/* Default to encoding 1 so these should be 64 */
+	gsm->mtu = 64;
+	gsm->dead = 1;	/* Avoid early tty opens */
+
+	return gsm;
+}
+EXPORT_SYMBOL_GPL(gsm_alloc_mux);
+
+
+
+
+/**
+ *	gsmld_output		-	write to link
+ *	@gsm: our mux
+ *	@data: bytes to output
+ *	@len: size
+ *
+ *	Write a block of data from the GSM mux to the data channel. This
+ *	will eventually be serialized from above but at the moment isn't.
+ */
+
+static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len)
+{
+	if (tty_write_room(gsm->tty) < len) {
+		set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags);
+		return -ENOSPC;
+	}
+	if (debug & 4) {
+		printk("-->%d bytes out\n", len);
+		hex_packet(data, len);
+	}
+	gsm->tty->ops->write(gsm->tty, data, len);
+	return len;
+}
+
+/**
+ *	gsmld_attach_gsm	-	mode set up
+ *	@tty: our tty structure
+ *	@gsm: our mux
+ *
+ *	Set up the MUX for basic mode and commence connecting to the
+ *	modem. Currently called from the line discipline set up but
+ *	will need moving to an ioctl path.
+ */
+
+static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
+{
+	int ret;
+
+	gsm->tty = tty_kref_get(tty);
+	gsm->output = gsmld_output;
+	ret =  gsm_activate_mux(gsm);
+	if (ret != 0)
+		tty_kref_put(gsm->tty);
+	return ret;
+}
+
+
+/**
+ *	gsmld_detach_gsm	-	stop doing 0710 mux
+ *	@tty: tty atttached to the mux
+ *	@gsm: mux
+ *
+ *	Shutdown and then clean up the resources used by the line discipline
+ */
+
+static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
+{
+	WARN_ON(tty != gsm->tty);
+	gsm_cleanup_mux(gsm);
+	tty_kref_put(gsm->tty);
+	gsm->tty = NULL;
+}
+
+static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+			      char *fp, int count)
+{
+	struct gsm_mux *gsm = tty->disc_data;
+	const unsigned char *dp;
+	char *f;
+	int i;
+	char buf[64];
+	char flags;
+
+	if (debug & 4) {
+		printk("Inbytes %dd\n", count);
+		hex_packet(cp, count);
+	}
+
+	for (i = count, dp = cp, f = fp; i; i--, dp++) {
+		flags = *f++;
+		switch (flags) {
+		case TTY_NORMAL:
+			gsm->receive(gsm, *dp);
+			break;
+		case TTY_OVERRUN:
+		case TTY_BREAK:
+		case TTY_PARITY:
+		case TTY_FRAME:
+			gsm->error(gsm, *dp, flags);
+			break;
+		default:
+			printk(KERN_ERR "%s: unknown flag %d\n",
+			       tty_name(tty, buf), flags);
+			break;
+		}
+	}
+	/* FASYNC if needed ? */
+	/* If clogged call tty_throttle(tty); */
+}
+
+/**
+ *	gsmld_chars_in_buffer	-	report available bytes
+ *	@tty: tty device
+ *
+ *	Report the number of characters buffered to be delivered to user
+ *	at this instant in time.
+ *
+ *	Locking: gsm lock
+ */
+
+static ssize_t gsmld_chars_in_buffer(struct tty_struct *tty)
+{
+	return 0;
+}
+
+/**
+ *	gsmld_flush_buffer	-	clean input queue
+ *	@tty:	terminal device
+ *
+ *	Flush the input buffer. Called when the line discipline is
+ *	being closed, when the tty layer wants the buffer flushed (eg
+ *	at hangup).
+ */
+
+static void gsmld_flush_buffer(struct tty_struct *tty)
+{
+}
+
+/**
+ *	gsmld_close		-	close the ldisc for this tty
+ *	@tty: device
+ *
+ *	Called from the terminal layer when this line discipline is
+ *	being shut down, either because of a close or becsuse of a
+ *	discipline change. The function will not be called while other
+ *	ldisc methods are in progress.
+ */
+
+static void gsmld_close(struct tty_struct *tty)
+{
+	struct gsm_mux *gsm = tty->disc_data;
+
+	gsmld_detach_gsm(tty, gsm);
+
+	gsmld_flush_buffer(tty);
+	/* Do other clean up here */
+	gsm_free_mux(gsm);
+}
+
+/**
+ *	gsmld_open		-	open an ldisc
+ *	@tty: terminal to open
+ *
+ *	Called when this line discipline is being attached to the
+ *	terminal device. Can sleep. Called serialized so that no
+ *	other events will occur in parallel. No further open will occur
+ *	until a close.
+ */
+
+static int gsmld_open(struct tty_struct *tty)
+{
+	struct gsm_mux *gsm;
+
+	if (tty->ops->write == NULL)
+		return -EINVAL;
+
+	/* Attach our ldisc data */
+	gsm = gsm_alloc_mux();
+	if (gsm == NULL)
+		return -ENOMEM;
+
+	tty->disc_data = gsm;
+	tty->receive_room = 65536;
+
+	/* Attach the initial passive connection */
+	gsm->encoding = 1;
+	return gsmld_attach_gsm(tty, gsm);
+}
+
+/**
+ *	gsmld_write_wakeup	-	asynchronous I/O notifier
+ *	@tty: tty device
+ *
+ *	Required for the ptys, serial driver etc. since processes
+ *	that attach themselves to the master and rely on ASYNC
+ *	IO must be woken up
+ */
+
+static void gsmld_write_wakeup(struct tty_struct *tty)
+{
+	struct gsm_mux *gsm = tty->disc_data;
+	unsigned long flags;
+
+	/* Queue poll */
+	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	gsm_data_kick(gsm);
+	if (gsm->tx_bytes < TX_THRESH_LO) {
+		spin_lock_irqsave(&gsm->tx_lock, flags);
+		gsm_dlci_data_sweep(gsm);
+		spin_unlock_irqrestore(&gsm->tx_lock, flags);
+	}
+}
+
+/**
+ *	gsmld_read		-	read function for tty
+ *	@tty: tty device
+ *	@file: file object
+ *	@buf: userspace buffer pointer
+ *	@nr: size of I/O
+ *
+ *	Perform reads for the line discipline. We are guaranteed that the
+ *	line discipline will not be closed under us but we may get multiple
+ *	parallel readers and must handle this ourselves. We may also get
+ *	a hangup. Always called in user context, may sleep.
+ *
+ *	This code must be sure never to sleep through a hangup.
+ */
+
+static ssize_t gsmld_read(struct tty_struct *tty, struct file *file,
+			 unsigned char __user *buf, size_t nr)
+{
+	return -EOPNOTSUPP;
+}
+
+/**
+ *	gsmld_write		-	write function for tty
+ *	@tty: tty device
+ *	@file: file object
+ *	@buf: userspace buffer pointer
+ *	@nr: size of I/O
+ *
+ *	Called when the owner of the device wants to send a frame
+ *	itself (or some other control data). The data is transferred
+ *	as-is and must be properly framed and checksummed as appropriate
+ *	by userspace. Frames are either sent whole or not at all as this
+ *	avoids pain user side.
+ */
+
+static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
+			   const unsigned char *buf, size_t nr)
+{
+	int space = tty_write_room(tty);
+	if (space >= nr)
+		return tty->ops->write(tty, buf, nr);
+	set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	return -ENOBUFS;
+}
+
+/**
+ *	gsmld_poll		-	poll method for N_GSM0710
+ *	@tty: terminal device
+ *	@file: file accessing it
+ *	@wait: poll table
+ *
+ *	Called when the line discipline is asked to poll() for data or
+ *	for special events. This code is not serialized with respect to
+ *	other events save open/close.
+ *
+ *	This code must be sure never to sleep through a hangup.
+ *	Called without the kernel lock held - fine
+ */
+
+static unsigned int gsmld_poll(struct tty_struct *tty, struct file *file,
+							poll_table *wait)
+{
+	unsigned int mask = 0;
+	struct gsm_mux *gsm = tty->disc_data;
+
+	poll_wait(file, &tty->read_wait, wait);
+	poll_wait(file, &tty->write_wait, wait);
+	if (tty_hung_up_p(file))
+		mask |= POLLHUP;
+	if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0)
+		mask |= POLLOUT | POLLWRNORM;
+	if (gsm->dead)
+		mask |= POLLHUP;
+	return mask;
+}
+
+static int gsmld_config(struct tty_struct *tty, struct gsm_mux *gsm,
+							struct gsm_config *c)
+{
+	int need_close = 0;
+	int need_restart = 0;
+
+	/* Stuff we don't support yet - UI or I frame transport, windowing */
+	if ((c->adaption !=1 && c->adaption != 2) || c->k)
+		return -EOPNOTSUPP;
+	/* Check the MRU/MTU range looks sane */
+	if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8)
+		return -EINVAL;
+	if (c->n2 < 3)
+		return -EINVAL;
+	if (c->encapsulation > 1)	/* Basic, advanced, no I */
+		return -EINVAL;
+	if (c->initiator > 1)
+		return -EINVAL;
+	if (c->i == 0 || c->i > 2)	/* UIH and UI only */
+		return -EINVAL;
+	/*
+	 *	See what is needed for reconfiguration
+	 */
+
+	/* Timing fields */
+	if (c->t1 != 0 && c->t1 != gsm->t1)
+		need_restart = 1;
+	if (c->t2 != 0 && c->t2 != gsm->t2)
+		need_restart = 1;
+	if (c->encapsulation != gsm->encoding)
+		need_restart = 1;
+	if (c->adaption != gsm->adaption)
+		need_restart = 1;
+	/* Requires care */
+	if (c->initiator != gsm->initiator)
+		need_close = 1;
+	if (c->mru != gsm->mru)
+		need_restart = 1;
+	if (c->mtu != gsm->mtu)
+		need_restart = 1;
+
+	/*
+	 *	Close down what is needed, restart and initiate the new
+	 *	configuration
+	 */
+
+	if (need_close || need_restart) {
+		gsm_dlci_begin_close(gsm->dlci[0]);
+		/* This will timeout if the link is down due to N2 expiring */
+		wait_event_interruptible(gsm->event,
+				gsm->dlci[0]->state == DLCI_CLOSED);
+		if (signal_pending(current))
+			return -EINTR;
+	}
+	if (need_restart)
+		gsm_cleanup_mux(gsm);
+
+	gsm->initiator = c->initiator;
+	gsm->mru = c->mru;
+	gsm->encoding = c->encapsulation;
+	gsm->adaption = c->adaption;
+	gsm->n2 = c->n2;
+
+	if (c->i == 1)
+		gsm->ftype = UIH;
+	else if (c->i == 2)
+		gsm->ftype = UI;
+
+	if (c->t1)
+		gsm->t1 = c->t1;
+	if (c->t2)
+		gsm->t2 = c->t2;
+
+	/* FIXME: We need to separate activation/deactivation from adding
+	   and removing from the mux array */
+	if (need_restart)
+		gsm_activate_mux(gsm);
+	if (gsm->initiator && need_close)
+		gsm_dlci_begin_open(gsm->dlci[0]);
+	return 0;
+}
+
+static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
+		       unsigned int cmd, unsigned long arg)
+{
+	struct gsm_config c;
+	struct gsm_mux *gsm = tty->disc_data;
+
+	switch (cmd) {
+	case GSMIOC_GETCONF:
+		memset(&c, 0, sizeof(c));
+		c.adaption = gsm->adaption;
+		c.encapsulation = gsm->encoding;
+		c.initiator = gsm->initiator;
+		c.t1 = gsm->t1;
+		c.t2 = gsm->t2;
+		c.t3 = 0;	/* Not supported */
+		c.n2 = gsm->n2;
+		if (gsm->ftype == UIH)
+			c.i = 1;
+		else
+			c.i = 2;
+		printk("Ftype %d i %d\n", gsm->ftype, c.i);
+		c.mru = gsm->mru;
+		c.mtu = gsm->mtu;
+		c.k = 0;
+		if (copy_to_user((void *)arg, &c, sizeof(c)))
+			return -EFAULT;
+		return 0;
+	case GSMIOC_SETCONF:
+		if (copy_from_user(&c, (void *)arg, sizeof(c)))
+			return -EFAULT;
+		return gsmld_config(tty, gsm, &c);
+	default:
+		return n_tty_ioctl_helper(tty, file, cmd, arg);
+	}
+}
+
+
+/* Line discipline for real tty */
+struct tty_ldisc_ops tty_ldisc_packet = {
+	.owner		 = THIS_MODULE,
+	.magic           = TTY_LDISC_MAGIC,
+	.name            = "n_gsm",
+	.open            = gsmld_open,
+	.close           = gsmld_close,
+	.flush_buffer    = gsmld_flush_buffer,
+	.chars_in_buffer = gsmld_chars_in_buffer,
+	.read            = gsmld_read,
+	.write           = gsmld_write,
+	.ioctl           = gsmld_ioctl,
+	.poll            = gsmld_poll,
+	.receive_buf     = gsmld_receive_buf,
+	.write_wakeup    = gsmld_write_wakeup
+};
+
+/*
+ *	Virtual tty side
+ */
+
+#define TX_SIZE		512
+
+static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk)
+{
+	u8 modembits[5];
+	struct gsm_control *ctrl;
+	int len = 2;
+
+	if (brk)
+		len++;
+
+	modembits[0] = len << 1 | EA;		/* Data bytes */
+	modembits[1] = dlci->addr << 2 | 3;	/* DLCI, EA, 1 */
+	modembits[2] = gsm_encode_modem(dlci) << 1 | EA;
+	if (brk)
+		modembits[3] = brk << 4 | 2 | EA;	/* Valid, EA */
+	ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len + 1);
+	if (ctrl == NULL)
+		return -ENOMEM;
+	return gsm_control_wait(dlci->gsm, ctrl);
+}
+
+static int gsm_carrier_raised(struct tty_port *port)
+{
+	struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
+	/* Not yet open so no carrier info */
+	if (dlci->state != DLCI_OPEN)
+		return 0;
+	if (debug & 2)
+		return 1;
+	return dlci->modem_rx & TIOCM_CD;
+}
+
+static void gsm_dtr_rts(struct tty_port *port, int onoff)
+{
+	struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
+	unsigned int modem_tx = dlci->modem_tx;
+	if (onoff)
+		modem_tx |= TIOCM_DTR | TIOCM_RTS;
+	else
+		modem_tx &= ~(TIOCM_DTR | TIOCM_RTS);
+	if (modem_tx != dlci->modem_tx) {
+		dlci->modem_tx = modem_tx;
+		gsmtty_modem_update(dlci, 0);
+	}
+}
+
+static const struct tty_port_operations gsm_port_ops = {
+	.carrier_raised = gsm_carrier_raised,
+	.dtr_rts = gsm_dtr_rts,
+};
+
+
+static int gsmtty_open(struct tty_struct *tty, struct file *filp)
+{
+	struct gsm_mux *gsm;
+	struct gsm_dlci *dlci;
+	struct tty_port *port;
+	unsigned int line = tty->index;
+	unsigned int mux = line >> 6;
+
+	line = line & 0x3F;
+
+	if (mux >= MAX_MUX)
+		return -ENXIO;
+	/* FIXME: we need to lock gsm_mux for lifetimes of ttys eventually */
+	if (gsm_mux[mux] == NULL)
+		return -EUNATCH;
+	if (line == 0 || line > 61)	/* 62/63 reserved */
+		return -ECHRNG;
+	gsm = gsm_mux[mux];
+	if (gsm->dead)
+		return -EL2HLT;
+	dlci = gsm->dlci[line];
+	if (dlci == NULL)
+		dlci = gsm_dlci_alloc(gsm, line);
+	if (dlci == NULL)
+		return -ENOMEM;
+	port = &dlci->port;
+	port->count++;
+	tty->driver_data = dlci;
+	tty_port_tty_set(port, tty);
+
+	dlci->modem_rx = 0;
+	/* We could in theory open and close before we wait - eg if we get
+	   a DM straight back. This is ok as that will have caused a hangup */
+	set_bit(ASYNCB_INITIALIZED, &port->flags);
+	/* Start sending off SABM messages */
+	gsm_dlci_begin_open(dlci);
+	/* And wait for virtual carrier */
+	return tty_port_block_til_ready(port, tty, filp);
+}
+
+static void gsmtty_close(struct tty_struct *tty, struct file *filp)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (dlci == NULL)
+		return;
+	if (tty_port_close_start(&dlci->port, tty, filp) == 0)
+		return;
+	gsm_dlci_begin_close(dlci);
+	tty_port_close_end(&dlci->port, tty);
+	tty_port_tty_set(&dlci->port, NULL);
+}
+
+static void gsmtty_hangup(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	tty_port_hangup(&dlci->port);
+	gsm_dlci_begin_close(dlci);
+}
+
+static int gsmtty_write(struct tty_struct *tty, const unsigned char *buf,
+								    int len)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	/* Stuff the bytes into the fifo queue */
+	int sent = kfifo_in_locked(dlci->fifo, buf, len, &dlci->lock);
+	/* Need to kick the channel */
+	gsm_dlci_data_kick(dlci);
+	return sent;
+}
+
+static int gsmtty_write_room(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	return TX_SIZE - kfifo_len(dlci->fifo);
+}
+
+static int gsmtty_chars_in_buffer(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	return kfifo_len(dlci->fifo);
+}
+
+static void gsmtty_flush_buffer(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	/* Caution needed: If we implement reliable transport classes
+	   then the data being transmitted can't simply be junked once
+	   it has first hit the stack. Until then we can just blow it
+	   away */
+	kfifo_reset(dlci->fifo);
+	/* Need to unhook this DLCI from the transmit queue logic */
+}
+
+static void gsmtty_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+	/* The FIFO handles the queue so the kernel will do the right
+	   thing waiting on chars_in_buffer before calling us. No work
+	   to do here */
+}
+
+static int gsmtty_tiocmget(struct tty_struct *tty, struct file *filp)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	return dlci->modem_rx;
+}
+
+static int gsmtty_tiocmset(struct tty_struct *tty, struct file *filp,
+	unsigned int set, unsigned int clear)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	unsigned int modem_tx = dlci->modem_tx;
+
+	modem_tx &= clear;
+	modem_tx |= set;
+
+	if (modem_tx != dlci->modem_tx) {
+		dlci->modem_tx = modem_tx;
+		return gsmtty_modem_update(dlci, 0);
+	}
+	return 0;
+}
+
+
+static int gsmtty_ioctl(struct tty_struct *tty, struct file *filp,
+			unsigned int cmd, unsigned long arg)
+{
+	return -ENOIOCTLCMD;
+}
+
+static void gsmtty_set_termios(struct tty_struct *tty, struct ktermios *old)
+{
+	/* For the moment its fixed. In actual fact the speed information
+	   for the virtual channel can be propogated in both directions by
+	   the RPN control message. This however rapidly gets nasty as we
+	   then have to remap modem signals each way according to whether
+	   our virtual cable is null modem etc .. */
+	tty_termios_copy_hw(tty->termios, old);
+}
+
+static void gsmtty_throttle(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (tty->termios->c_cflag & CRTSCTS)
+		dlci->modem_tx &= ~TIOCM_DTR;
+	dlci->throttled = 1;
+	/* Send an MSC with DTR cleared */
+	gsmtty_modem_update(dlci, 0);
+}
+
+static void gsmtty_unthrottle(struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	if (tty->termios->c_cflag & CRTSCTS)
+		dlci->modem_tx |= TIOCM_DTR;
+	dlci->throttled = 0;
+	/* Send an MSC with DTR set */
+	gsmtty_modem_update(dlci, 0);
+}
+
+static int gsmtty_break_ctl(struct tty_struct *tty, int state)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	int encode = 0;	/* Off */
+
+	if (state == -1)	/* "On indefinitely" - we can't encode this
+				    properly */
+		encode = 0x0F;
+	else if (state > 0) {
+		encode = state / 200;	/* mS to encoding */
+		if (encode > 0x0F)
+			encode = 0x0F;	/* Best effort */
+	}
+	return gsmtty_modem_update(dlci, encode);
+}
+
+static struct tty_driver *gsm_tty_driver;
+
+/* Virtual ttys for the demux */
+static const struct tty_operations gsmtty_ops = {
+	.open			= gsmtty_open,
+	.close			= gsmtty_close,
+	.write			= gsmtty_write,
+	.write_room		= gsmtty_write_room,
+	.chars_in_buffer	= gsmtty_chars_in_buffer,
+	.flush_buffer		= gsmtty_flush_buffer,
+	.ioctl			= gsmtty_ioctl,
+	.throttle		= gsmtty_throttle,
+	.unthrottle		= gsmtty_unthrottle,
+	.set_termios		= gsmtty_set_termios,
+	.hangup			= gsmtty_hangup,
+	.wait_until_sent	= gsmtty_wait_until_sent,
+	.tiocmget		= gsmtty_tiocmget,
+	.tiocmset		= gsmtty_tiocmset,
+	.break_ctl		= gsmtty_break_ctl,
+};
+
+
+
+static int __init gsm_init(void)
+{
+	/* Fill in our line protocol discipline, and register it */
+	int status = tty_register_ldisc(N_GSM0710, &tty_ldisc_packet);
+	if (status != 0) {
+		printk(KERN_ERR "n_gsm: can't register line discipline (err = %d)\n", status);
+		return status;
+	}
+
+	gsm_tty_driver = alloc_tty_driver(256);
+	if (!gsm_tty_driver) {
+		tty_unregister_ldisc(N_GSM0710);
+		printk(KERN_ERR "gsm_init: tty allocation failed.\n");
+		return -EINVAL;
+	}
+	gsm_tty_driver->owner	= THIS_MODULE;
+	gsm_tty_driver->driver_name	= "gsmtty";
+	gsm_tty_driver->name		= "gsmtty";
+	gsm_tty_driver->major		= 0;	/* Dynamic */
+	gsm_tty_driver->minor_start	= 0;
+	gsm_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
+	gsm_tty_driver->subtype	= SERIAL_TYPE_NORMAL;
+	gsm_tty_driver->flags	= TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV
+							| TTY_DRIVER_HARDWARE_BREAK;
+	gsm_tty_driver->init_termios	= tty_std_termios;
+	/* Fixme */
+	gsm_tty_driver->init_termios.c_lflag &= ~ECHO;
+	tty_set_operations(gsm_tty_driver, &gsmtty_ops);
+
+	spin_lock_init(&gsm_mux_lock);
+
+	if (tty_register_driver(gsm_tty_driver)) {
+		put_tty_driver(gsm_tty_driver);
+		tty_unregister_ldisc(N_GSM0710);
+		printk(KERN_ERR "gsm_init: tty registration failed.\n");
+		return -EBUSY;
+	}
+	printk(KERN_INFO "gsm_init: loaded as %d,%d.\n", gsm_tty_driver->major, gsm_tty_driver->minor_start);
+	return 0;
+}
+
+static void __exit gsm_exit(void)
+{
+	int status = tty_unregister_ldisc(N_GSM0710);
+	if (status != 0)
+		printk(KERN_ERR "n_gsm: can't unregister line discipline (err = %d)\n", status);
+	tty_unregister_driver(gsm_tty_driver);
+	put_tty_driver(gsm_tty_driver);
+	printk(KERN_INFO "gsm_init: unloaded.\n");
+}
+
+module_init(gsm_init);
+module_exit(gsm_exit);
+
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_LDISC(N_GSM0710);
diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
new file mode 100644
index 0000000..47d3228
--- /dev/null
+++ b/drivers/tty/n_hdlc.c
@@ -0,0 +1,1007 @@
+/* generic HDLC line discipline for Linux
+ *
+ * Written by Paul Fulghum paulkf@microgate.com
+ * for Microgate Corporation
+ *
+ * Microgate and SyncLink are registered trademarks of Microgate Corporation
+ *
+ * Adapted from ppp.c, written by Michael Callahan <callahan@maths.ox.ac.uk>,
+ *	Al Longyear <longyear@netcom.com>,
+ *	Paul Mackerras <Paul.Mackerras@cs.anu.edu.au>
+ *
+ * Original release 01/11/99
+ *
+ * This code is released under the GNU General Public License (GPL)
+ *
+ * This module implements the tty line discipline N_HDLC for use with
+ * tty device drivers that support bit-synchronous HDLC communications.
+ *
+ * All HDLC data is frame oriented which means:
+ *
+ * 1. tty write calls represent one complete transmit frame of data
+ *    The device driver should accept the complete frame or none of 
+ *    the frame (busy) in the write method. Each write call should have
+ *    a byte count in the range of 2-65535 bytes (2 is min HDLC frame
+ *    with 1 addr byte and 1 ctrl byte). The max byte count of 65535
+ *    should include any crc bytes required. For example, when using
+ *    CCITT CRC32, 4 crc bytes are required, so the maximum size frame
+ *    the application may transmit is limited to 65531 bytes. For CCITT
+ *    CRC16, the maximum application frame size would be 65533.
+ *
+ *
+ * 2. receive callbacks from the device driver represents
+ *    one received frame. The device driver should bypass
+ *    the tty flip buffer and call the line discipline receive
+ *    callback directly to avoid fragmenting or concatenating
+ *    multiple frames into a single receive callback.
+ *
+ *    The HDLC line discipline queues the receive frames in separate
+ *    buffers so complete receive frames can be returned by the
+ *    tty read calls.
+ *
+ * 3. tty read calls returns an entire frame of data or nothing.
+ *    
+ * 4. all send and receive data is considered raw. No processing
+ *    or translation is performed by the line discipline, regardless
+ *    of the tty flags
+ *
+ * 5. When line discipline is queried for the amount of receive
+ *    data available (FIOC), 0 is returned if no data available,
+ *    otherwise the count of the next available frame is returned.
+ *    (instead of the sum of all received frame counts).
+ *
+ * These conventions allow the standard tty programming interface
+ * to be used for synchronous HDLC applications when used with
+ * this line discipline (or another line discipline that is frame
+ * oriented such as N_PPP).
+ *
+ * The SyncLink driver (synclink.c) implements both asynchronous
+ * (using standard line discipline N_TTY) and synchronous HDLC
+ * (using N_HDLC) communications, with the latter using the above
+ * conventions.
+ *
+ * This implementation is very basic and does not maintain
+ * any statistics. The main point is to enforce the raw data
+ * and frame orientation of HDLC communications.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define HDLC_MAGIC 0x239e
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+
+#undef VERSION
+#define VERSION(major,minor,patch) (((((major)<<8)+(minor))<<8)+(patch))
+
+#include <linux/poll.h>
+#include <linux/in.h>
+#include <linux/ioctl.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/errno.h>
+#include <linux/smp_lock.h>
+#include <linux/string.h>	/* used in new tty drivers */
+#include <linux/signal.h>	/* used in new tty drivers */
+#include <linux/if.h>
+#include <linux/bitops.h>
+
+#include <asm/system.h>
+#include <asm/termios.h>
+#include <asm/uaccess.h>
+
+/*
+ * Buffers for individual HDLC frames
+ */
+#define MAX_HDLC_FRAME_SIZE 65535 
+#define DEFAULT_RX_BUF_COUNT 10
+#define MAX_RX_BUF_COUNT 60
+#define DEFAULT_TX_BUF_COUNT 3
+
+struct n_hdlc_buf {
+	struct n_hdlc_buf *link;
+	int		  count;
+	char		  buf[1];
+};
+
+#define	N_HDLC_BUF_SIZE	(sizeof(struct n_hdlc_buf) + maxframe)
+
+struct n_hdlc_buf_list {
+	struct n_hdlc_buf *head;
+	struct n_hdlc_buf *tail;
+	int		  count;
+	spinlock_t	  spinlock;
+};
+
+/**
+ * struct n_hdlc - per device instance data structure
+ * @magic - magic value for structure
+ * @flags - miscellaneous control flags
+ * @tty - ptr to TTY structure
+ * @backup_tty - TTY to use if tty gets closed
+ * @tbusy - reentrancy flag for tx wakeup code
+ * @woke_up - FIXME: describe this field
+ * @tbuf - currently transmitting tx buffer
+ * @tx_buf_list - list of pending transmit frame buffers
+ * @rx_buf_list - list of received frame buffers
+ * @tx_free_buf_list - list unused transmit frame buffers
+ * @rx_free_buf_list - list unused received frame buffers
+ */
+struct n_hdlc {
+	int			magic;
+	__u32			flags;
+	struct tty_struct	*tty;
+	struct tty_struct	*backup_tty;
+	int			tbusy;
+	int			woke_up;
+	struct n_hdlc_buf	*tbuf;
+	struct n_hdlc_buf_list	tx_buf_list;
+	struct n_hdlc_buf_list	rx_buf_list;
+	struct n_hdlc_buf_list	tx_free_buf_list;
+	struct n_hdlc_buf_list	rx_free_buf_list;
+};
+
+/*
+ * HDLC buffer list manipulation functions
+ */
+static void n_hdlc_buf_list_init(struct n_hdlc_buf_list *list);
+static void n_hdlc_buf_put(struct n_hdlc_buf_list *list,
+			   struct n_hdlc_buf *buf);
+static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *list);
+
+/* Local functions */
+
+static struct n_hdlc *n_hdlc_alloc (void);
+
+/* debug level can be set by insmod for debugging purposes */
+#define DEBUG_LEVEL_INFO	1
+static int debuglevel;
+
+/* max frame size for memory allocations */
+static int maxframe = 4096;
+
+/* TTY callbacks */
+
+static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
+			   __u8 __user *buf, size_t nr);
+static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
+			    const unsigned char *buf, size_t nr);
+static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
+			    unsigned int cmd, unsigned long arg);
+static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
+				    poll_table *wait);
+static int n_hdlc_tty_open(struct tty_struct *tty);
+static void n_hdlc_tty_close(struct tty_struct *tty);
+static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *cp,
+			       char *fp, int count);
+static void n_hdlc_tty_wakeup(struct tty_struct *tty);
+
+#define bset(p,b)	((p)[(b) >> 5] |= (1 << ((b) & 0x1f)))
+
+#define tty2n_hdlc(tty)	((struct n_hdlc *) ((tty)->disc_data))
+#define n_hdlc2tty(n_hdlc)	((n_hdlc)->tty)
+
+static void flush_rx_queue(struct tty_struct *tty)
+{
+	struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
+	struct n_hdlc_buf *buf;
+
+	while ((buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list)))
+		n_hdlc_buf_put(&n_hdlc->rx_free_buf_list, buf);
+}
+
+static void flush_tx_queue(struct tty_struct *tty)
+{
+	struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
+	struct n_hdlc_buf *buf;
+	unsigned long flags;
+
+	while ((buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list)))
+		n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, buf);
+ 	spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
+	if (n_hdlc->tbuf) {
+		n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, n_hdlc->tbuf);
+		n_hdlc->tbuf = NULL;
+	}
+	spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+}
+
+static struct tty_ldisc_ops n_hdlc_ldisc = {
+	.owner		= THIS_MODULE,
+	.magic		= TTY_LDISC_MAGIC,
+	.name		= "hdlc",
+	.open		= n_hdlc_tty_open,
+	.close		= n_hdlc_tty_close,
+	.read		= n_hdlc_tty_read,
+	.write		= n_hdlc_tty_write,
+	.ioctl		= n_hdlc_tty_ioctl,
+	.poll		= n_hdlc_tty_poll,
+	.receive_buf	= n_hdlc_tty_receive,
+	.write_wakeup	= n_hdlc_tty_wakeup,
+	.flush_buffer   = flush_rx_queue,
+};
+
+/**
+ * n_hdlc_release - release an n_hdlc per device line discipline info structure
+ * @n_hdlc - per device line discipline info structure
+ */
+static void n_hdlc_release(struct n_hdlc *n_hdlc)
+{
+	struct tty_struct *tty = n_hdlc2tty (n_hdlc);
+	struct n_hdlc_buf *buf;
+	
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_release() called\n",__FILE__,__LINE__);
+		
+	/* Ensure that the n_hdlcd process is not hanging on select()/poll() */
+	wake_up_interruptible (&tty->read_wait);
+	wake_up_interruptible (&tty->write_wait);
+
+	if (tty->disc_data == n_hdlc)
+		tty->disc_data = NULL;	/* Break the tty->n_hdlc link */
+
+	/* Release transmit and receive buffers */
+	for(;;) {
+		buf = n_hdlc_buf_get(&n_hdlc->rx_free_buf_list);
+		if (buf) {
+			kfree(buf);
+		} else
+			break;
+	}
+	for(;;) {
+		buf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list);
+		if (buf) {
+			kfree(buf);
+		} else
+			break;
+	}
+	for(;;) {
+		buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);
+		if (buf) {
+			kfree(buf);
+		} else
+			break;
+	}
+	for(;;) {
+		buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
+		if (buf) {
+			kfree(buf);
+		} else
+			break;
+	}
+	kfree(n_hdlc->tbuf);
+	kfree(n_hdlc);
+	
+}	/* end of n_hdlc_release() */
+
+/**
+ * n_hdlc_tty_close - line discipline close
+ * @tty - pointer to tty info structure
+ *
+ * Called when the line discipline is changed to something
+ * else, the tty is closed, or the tty detects a hangup.
+ */
+static void n_hdlc_tty_close(struct tty_struct *tty)
+{
+	struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_tty_close() called\n",__FILE__,__LINE__);
+		
+	if (n_hdlc != NULL) {
+		if (n_hdlc->magic != HDLC_MAGIC) {
+			printk (KERN_WARNING"n_hdlc: trying to close unopened tty!\n");
+			return;
+		}
+#if defined(TTY_NO_WRITE_SPLIT)
+		clear_bit(TTY_NO_WRITE_SPLIT,&tty->flags);
+#endif
+		tty->disc_data = NULL;
+		if (tty == n_hdlc->backup_tty)
+			n_hdlc->backup_tty = NULL;
+		if (tty != n_hdlc->tty)
+			return;
+		if (n_hdlc->backup_tty) {
+			n_hdlc->tty = n_hdlc->backup_tty;
+		} else {
+			n_hdlc_release (n_hdlc);
+		}
+	}
+	
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_tty_close() success\n",__FILE__,__LINE__);
+		
+}	/* end of n_hdlc_tty_close() */
+
+/**
+ * n_hdlc_tty_open - called when line discipline changed to n_hdlc
+ * @tty - pointer to tty info structure
+ *
+ * Returns 0 if success, otherwise error code
+ */
+static int n_hdlc_tty_open (struct tty_struct *tty)
+{
+	struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_tty_open() called (device=%s)\n",
+		__FILE__,__LINE__,
+		tty->name);
+		
+	/* There should not be an existing table for this slot. */
+	if (n_hdlc) {
+		printk (KERN_ERR"n_hdlc_tty_open:tty already associated!\n" );
+		return -EEXIST;
+	}
+	
+	n_hdlc = n_hdlc_alloc();
+	if (!n_hdlc) {
+		printk (KERN_ERR "n_hdlc_alloc failed\n");
+		return -ENFILE;
+	}
+		
+	tty->disc_data = n_hdlc;
+	n_hdlc->tty    = tty;
+	tty->receive_room = 65536;
+	
+#if defined(TTY_NO_WRITE_SPLIT)
+	/* change tty_io write() to not split large writes into 8K chunks */
+	set_bit(TTY_NO_WRITE_SPLIT,&tty->flags);
+#endif
+	
+	/* flush receive data from driver */
+	tty_driver_flush_buffer(tty);
+		
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_tty_open() success\n",__FILE__,__LINE__);
+		
+	return 0;
+	
+}	/* end of n_tty_hdlc_open() */
+
+/**
+ * n_hdlc_send_frames - send frames on pending send buffer list
+ * @n_hdlc - pointer to ldisc instance data
+ * @tty - pointer to tty instance data
+ *
+ * Send frames on pending send buffer list until the driver does not accept a
+ * frame (busy) this function is called after adding a frame to the send buffer
+ * list and by the tty wakeup callback.
+ */
+static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
+{
+	register int actual;
+	unsigned long flags;
+	struct n_hdlc_buf *tbuf;
+
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_send_frames() called\n",__FILE__,__LINE__);
+ check_again:
+		
+ 	spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
+	if (n_hdlc->tbusy) {
+		n_hdlc->woke_up = 1;
+ 		spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+		return;
+	}
+	n_hdlc->tbusy = 1;
+	n_hdlc->woke_up = 0;
+	spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+
+	/* get current transmit buffer or get new transmit */
+	/* buffer from list of pending transmit buffers */
+		
+	tbuf = n_hdlc->tbuf;
+	if (!tbuf)
+		tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
+		
+	while (tbuf) {
+		if (debuglevel >= DEBUG_LEVEL_INFO)	
+			printk("%s(%d)sending frame %p, count=%d\n",
+				__FILE__,__LINE__,tbuf,tbuf->count);
+			
+		/* Send the next block of data to device */
+		tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
+		actual = tty->ops->write(tty, tbuf->buf, tbuf->count);
+
+		/* rollback was possible and has been done */
+		if (actual == -ERESTARTSYS) {
+			n_hdlc->tbuf = tbuf;
+			break;
+		}
+		/* if transmit error, throw frame away by */
+		/* pretending it was accepted by driver */
+		if (actual < 0)
+			actual = tbuf->count;
+		
+		if (actual == tbuf->count) {
+			if (debuglevel >= DEBUG_LEVEL_INFO)	
+				printk("%s(%d)frame %p completed\n",
+					__FILE__,__LINE__,tbuf);
+					
+			/* free current transmit buffer */
+			n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, tbuf);
+			
+			/* this tx buffer is done */
+			n_hdlc->tbuf = NULL;
+			
+			/* wait up sleeping writers */
+			wake_up_interruptible(&tty->write_wait);
+	
+			/* get next pending transmit buffer */
+			tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
+		} else {
+			if (debuglevel >= DEBUG_LEVEL_INFO)	
+				printk("%s(%d)frame %p pending\n",
+					__FILE__,__LINE__,tbuf);
+					
+			/* buffer not accepted by driver */
+			/* set this buffer as pending buffer */
+			n_hdlc->tbuf = tbuf;
+			break;
+		}
+	}
+	
+	if (!tbuf)
+		tty->flags  &= ~(1 << TTY_DO_WRITE_WAKEUP);
+	
+	/* Clear the re-entry flag */
+	spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
+	n_hdlc->tbusy = 0;
+	spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags); 
+	
+        if (n_hdlc->woke_up)
+	  goto check_again;
+
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_send_frames() exit\n",__FILE__,__LINE__);
+		
+}	/* end of n_hdlc_send_frames() */
+
+/**
+ * n_hdlc_tty_wakeup - Callback for transmit wakeup
+ * @tty	- pointer to associated tty instance data
+ *
+ * Called when low level device driver can accept more send data.
+ */
+static void n_hdlc_tty_wakeup(struct tty_struct *tty)
+{
+	struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
+
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_tty_wakeup() called\n",__FILE__,__LINE__);
+		
+	if (!n_hdlc)
+		return;
+
+	if (tty != n_hdlc->tty) {
+		tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
+		return;
+	}
+
+	n_hdlc_send_frames (n_hdlc, tty);
+		
+}	/* end of n_hdlc_tty_wakeup() */
+
+/**
+ * n_hdlc_tty_receive - Called by tty driver when receive data is available
+ * @tty	- pointer to tty instance data
+ * @data - pointer to received data
+ * @flags - pointer to flags for data
+ * @count - count of received data in bytes
+ *
+ * Called by tty low level driver when receive data is available. Data is
+ * interpreted as one HDLC frame.
+ */
+static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data,
+			       char *flags, int count)
+{
+	register struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+	register struct n_hdlc_buf *buf;
+
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_tty_receive() called count=%d\n",
+			__FILE__,__LINE__, count);
+		
+	/* This can happen if stuff comes in on the backup tty */
+	if (!n_hdlc || tty != n_hdlc->tty)
+		return;
+		
+	/* verify line is using HDLC discipline */
+	if (n_hdlc->magic != HDLC_MAGIC) {
+		printk("%s(%d) line not using HDLC discipline\n",
+			__FILE__,__LINE__);
+		return;
+	}
+	
+	if ( count>maxframe ) {
+		if (debuglevel >= DEBUG_LEVEL_INFO)	
+			printk("%s(%d) rx count>maxframesize, data discarded\n",
+			       __FILE__,__LINE__);
+		return;
+	}
+
+	/* get a free HDLC buffer */	
+	buf = n_hdlc_buf_get(&n_hdlc->rx_free_buf_list);
+	if (!buf) {
+		/* no buffers in free list, attempt to allocate another rx buffer */
+		/* unless the maximum count has been reached */
+		if (n_hdlc->rx_buf_list.count < MAX_RX_BUF_COUNT)
+			buf = kmalloc(N_HDLC_BUF_SIZE, GFP_ATOMIC);
+	}
+	
+	if (!buf) {
+		if (debuglevel >= DEBUG_LEVEL_INFO)	
+			printk("%s(%d) no more rx buffers, data discarded\n",
+			       __FILE__,__LINE__);
+		return;
+	}
+		
+	/* copy received data to HDLC buffer */
+	memcpy(buf->buf,data,count);
+	buf->count=count;
+
+	/* add HDLC buffer to list of received frames */
+	n_hdlc_buf_put(&n_hdlc->rx_buf_list, buf);
+	
+	/* wake up any blocked reads and perform async signalling */
+	wake_up_interruptible (&tty->read_wait);
+	if (n_hdlc->tty->fasync != NULL)
+		kill_fasync (&n_hdlc->tty->fasync, SIGIO, POLL_IN);
+
+}	/* end of n_hdlc_tty_receive() */
+
+/**
+ * n_hdlc_tty_read - Called to retrieve one frame of data (if available)
+ * @tty - pointer to tty instance data
+ * @file - pointer to open file object
+ * @buf - pointer to returned data buffer
+ * @nr - size of returned data buffer
+ * 	
+ * Returns the number of bytes returned or error code.
+ */
+static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
+			   __u8 __user *buf, size_t nr)
+{
+	struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
+	int ret;
+	struct n_hdlc_buf *rbuf;
+
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_tty_read() called\n",__FILE__,__LINE__);
+		
+	/* Validate the pointers */
+	if (!n_hdlc)
+		return -EIO;
+
+	/* verify user access to buffer */
+	if (!access_ok(VERIFY_WRITE, buf, nr)) {
+		printk(KERN_WARNING "%s(%d) n_hdlc_tty_read() can't verify user "
+		"buffer\n", __FILE__, __LINE__);
+		return -EFAULT;
+	}
+
+	tty_lock();
+
+	for (;;) {
+		if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
+			tty_unlock();
+			return -EIO;
+		}
+
+		n_hdlc = tty2n_hdlc (tty);
+		if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC ||
+			 tty != n_hdlc->tty) {
+			tty_unlock();
+			return 0;
+		}
+
+		rbuf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);
+		if (rbuf)
+			break;
+			
+		/* no data */
+		if (file->f_flags & O_NONBLOCK) {
+			tty_unlock();
+			return -EAGAIN;
+		}
+			
+		interruptible_sleep_on (&tty->read_wait);
+		if (signal_pending(current)) {
+			tty_unlock();
+			return -EINTR;
+		}
+	}
+		
+	if (rbuf->count > nr)
+		/* frame too large for caller's buffer (discard frame) */
+		ret = -EOVERFLOW;
+	else {
+		/* Copy the data to the caller's buffer */
+		if (copy_to_user(buf, rbuf->buf, rbuf->count))
+			ret = -EFAULT;
+		else
+			ret = rbuf->count;
+	}
+	
+	/* return HDLC buffer to free list unless the free list */
+	/* count has exceeded the default value, in which case the */
+	/* buffer is freed back to the OS to conserve memory */
+	if (n_hdlc->rx_free_buf_list.count > DEFAULT_RX_BUF_COUNT)
+		kfree(rbuf);
+	else	
+		n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,rbuf);
+	tty_unlock();
+	return ret;
+	
+}	/* end of n_hdlc_tty_read() */
+
+/**
+ * n_hdlc_tty_write - write a single frame of data to device
+ * @tty	- pointer to associated tty device instance data
+ * @file - pointer to file object data
+ * @data - pointer to transmit data (one frame)
+ * @count - size of transmit frame in bytes
+ * 		
+ * Returns the number of bytes written (or error code).
+ */
+static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
+			    const unsigned char *data, size_t count)
+{
+	struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+	int error = 0;
+	DECLARE_WAITQUEUE(wait, current);
+	struct n_hdlc_buf *tbuf;
+
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_tty_write() called count=%Zd\n",
+			__FILE__,__LINE__,count);
+		
+	/* Verify pointers */
+	if (!n_hdlc)
+		return -EIO;
+
+	if (n_hdlc->magic != HDLC_MAGIC)
+		return -EIO;
+
+	/* verify frame size */
+	if (count > maxframe ) {
+		if (debuglevel & DEBUG_LEVEL_INFO)
+			printk (KERN_WARNING
+				"n_hdlc_tty_write: truncating user packet "
+				"from %lu to %d\n", (unsigned long) count,
+				maxframe );
+		count = maxframe;
+	}
+	
+	tty_lock();
+
+	add_wait_queue(&tty->write_wait, &wait);
+	set_current_state(TASK_INTERRUPTIBLE);
+	
+	/* Allocate transmit buffer */
+	/* sleep until transmit buffer available */		
+	while (!(tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list))) {
+		if (file->f_flags & O_NONBLOCK) {
+			error = -EAGAIN;
+			break;
+		}
+		schedule();
+			
+		n_hdlc = tty2n_hdlc (tty);
+		if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC || 
+		    tty != n_hdlc->tty) {
+			printk("n_hdlc_tty_write: %p invalid after wait!\n", n_hdlc);
+			error = -EIO;
+			break;
+		}
+			
+		if (signal_pending(current)) {
+			error = -EINTR;
+			break;
+		}
+	}
+
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&tty->write_wait, &wait);
+
+	if (!error) {		
+		/* Retrieve the user's buffer */
+		memcpy(tbuf->buf, data, count);
+
+		/* Send the data */
+		tbuf->count = error = count;
+		n_hdlc_buf_put(&n_hdlc->tx_buf_list,tbuf);
+		n_hdlc_send_frames(n_hdlc,tty);
+	}
+	tty_unlock();
+	return error;
+	
+}	/* end of n_hdlc_tty_write() */
+
+/**
+ * n_hdlc_tty_ioctl - process IOCTL system call for the tty device.
+ * @tty - pointer to tty instance data
+ * @file - pointer to open file object for device
+ * @cmd - IOCTL command code
+ * @arg - argument for IOCTL call (cmd dependent)
+ *
+ * Returns command dependent result.
+ */
+static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
+			    unsigned int cmd, unsigned long arg)
+{
+	struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+	int error = 0;
+	int count;
+	unsigned long flags;
+	
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_tty_ioctl() called %d\n",
+			__FILE__,__LINE__,cmd);
+		
+	/* Verify the status of the device */
+	if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC)
+		return -EBADF;
+
+	switch (cmd) {
+	case FIONREAD:
+		/* report count of read data available */
+		/* in next available frame (if any) */
+		spin_lock_irqsave(&n_hdlc->rx_buf_list.spinlock,flags);
+		if (n_hdlc->rx_buf_list.head)
+			count = n_hdlc->rx_buf_list.head->count;
+		else
+			count = 0;
+		spin_unlock_irqrestore(&n_hdlc->rx_buf_list.spinlock,flags);
+		error = put_user(count, (int __user *)arg);
+		break;
+
+	case TIOCOUTQ:
+		/* get the pending tx byte count in the driver */
+		count = tty_chars_in_buffer(tty);
+		/* add size of next output frame in queue */
+		spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock,flags);
+		if (n_hdlc->tx_buf_list.head)
+			count += n_hdlc->tx_buf_list.head->count;
+		spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock,flags);
+		error = put_user(count, (int __user *)arg);
+		break;
+
+	case TCFLSH:
+		switch (arg) {
+		case TCIOFLUSH:
+		case TCOFLUSH:
+			flush_tx_queue(tty);
+		}
+		/* fall through to default */
+
+	default:
+		error = n_tty_ioctl_helper(tty, file, cmd, arg);
+		break;
+	}
+	return error;
+	
+}	/* end of n_hdlc_tty_ioctl() */
+
+/**
+ * n_hdlc_tty_poll - TTY callback for poll system call
+ * @tty - pointer to tty instance data
+ * @filp - pointer to open file object for device
+ * @poll_table - wait queue for operations
+ * 
+ * Determine which operations (read/write) will not block and return info
+ * to caller.
+ * Returns a bit mask containing info on which ops will not block.
+ */
+static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
+				    poll_table *wait)
+{
+	struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+	unsigned int mask = 0;
+
+	if (debuglevel >= DEBUG_LEVEL_INFO)	
+		printk("%s(%d)n_hdlc_tty_poll() called\n",__FILE__,__LINE__);
+		
+	if (n_hdlc && n_hdlc->magic == HDLC_MAGIC && tty == n_hdlc->tty) {
+		/* queue current process into any wait queue that */
+		/* may awaken in the future (read and write) */
+
+		poll_wait(filp, &tty->read_wait, wait);
+		poll_wait(filp, &tty->write_wait, wait);
+
+		/* set bits for operations that won't block */
+		if (n_hdlc->rx_buf_list.head)
+			mask |= POLLIN | POLLRDNORM;	/* readable */
+		if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+			mask |= POLLHUP;
+		if (tty_hung_up_p(filp))
+			mask |= POLLHUP;
+		if (!tty_is_writelocked(tty) &&
+				n_hdlc->tx_free_buf_list.head)
+			mask |= POLLOUT | POLLWRNORM;	/* writable */
+	}
+	return mask;
+}	/* end of n_hdlc_tty_poll() */
+
+/**
+ * n_hdlc_alloc - allocate an n_hdlc instance data structure
+ *
+ * Returns a pointer to newly created structure if success, otherwise %NULL
+ */
+static struct n_hdlc *n_hdlc_alloc(void)
+{
+	struct n_hdlc_buf *buf;
+	int i;
+	struct n_hdlc *n_hdlc = kmalloc(sizeof(*n_hdlc), GFP_KERNEL);
+
+	if (!n_hdlc)
+		return NULL;
+
+	memset(n_hdlc, 0, sizeof(*n_hdlc));
+
+	n_hdlc_buf_list_init(&n_hdlc->rx_free_buf_list);
+	n_hdlc_buf_list_init(&n_hdlc->tx_free_buf_list);
+	n_hdlc_buf_list_init(&n_hdlc->rx_buf_list);
+	n_hdlc_buf_list_init(&n_hdlc->tx_buf_list);
+	
+	/* allocate free rx buffer list */
+	for(i=0;i<DEFAULT_RX_BUF_COUNT;i++) {
+		buf = kmalloc(N_HDLC_BUF_SIZE, GFP_KERNEL);
+		if (buf)
+			n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,buf);
+		else if (debuglevel >= DEBUG_LEVEL_INFO)	
+			printk("%s(%d)n_hdlc_alloc(), kalloc() failed for rx buffer %d\n",__FILE__,__LINE__, i);
+	}
+	
+	/* allocate free tx buffer list */
+	for(i=0;i<DEFAULT_TX_BUF_COUNT;i++) {
+		buf = kmalloc(N_HDLC_BUF_SIZE, GFP_KERNEL);
+		if (buf)
+			n_hdlc_buf_put(&n_hdlc->tx_free_buf_list,buf);
+		else if (debuglevel >= DEBUG_LEVEL_INFO)	
+			printk("%s(%d)n_hdlc_alloc(), kalloc() failed for tx buffer %d\n",__FILE__,__LINE__, i);
+	}
+	
+	/* Initialize the control block */
+	n_hdlc->magic  = HDLC_MAGIC;
+	n_hdlc->flags  = 0;
+	
+	return n_hdlc;
+	
+}	/* end of n_hdlc_alloc() */
+
+/**
+ * n_hdlc_buf_list_init - initialize specified HDLC buffer list
+ * @list - pointer to buffer list
+ */
+static void n_hdlc_buf_list_init(struct n_hdlc_buf_list *list)
+{
+	memset(list, 0, sizeof(*list));
+	spin_lock_init(&list->spinlock);
+}	/* end of n_hdlc_buf_list_init() */
+
+/**
+ * n_hdlc_buf_put - add specified HDLC buffer to tail of specified list
+ * @list - pointer to buffer list
+ * @buf	- pointer to buffer
+ */
+static void n_hdlc_buf_put(struct n_hdlc_buf_list *list,
+			   struct n_hdlc_buf *buf)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&list->spinlock,flags);
+	
+	buf->link=NULL;
+	if (list->tail)
+		list->tail->link = buf;
+	else
+		list->head = buf;
+	list->tail = buf;
+	(list->count)++;
+	
+	spin_unlock_irqrestore(&list->spinlock,flags);
+	
+}	/* end of n_hdlc_buf_put() */
+
+/**
+ * n_hdlc_buf_get - remove and return an HDLC buffer from list
+ * @list - pointer to HDLC buffer list
+ * 
+ * Remove and return an HDLC buffer from the head of the specified HDLC buffer
+ * list.
+ * Returns a pointer to HDLC buffer if available, otherwise %NULL.
+ */
+static struct n_hdlc_buf* n_hdlc_buf_get(struct n_hdlc_buf_list *list)
+{
+	unsigned long flags;
+	struct n_hdlc_buf *buf;
+	spin_lock_irqsave(&list->spinlock,flags);
+	
+	buf = list->head;
+	if (buf) {
+		list->head = buf->link;
+		(list->count)--;
+	}
+	if (!list->head)
+		list->tail = NULL;
+	
+	spin_unlock_irqrestore(&list->spinlock,flags);
+	return buf;
+	
+}	/* end of n_hdlc_buf_get() */
+
+static char hdlc_banner[] __initdata =
+	KERN_INFO "HDLC line discipline maxframe=%u\n";
+static char hdlc_register_ok[] __initdata =
+	KERN_INFO "N_HDLC line discipline registered.\n";
+static char hdlc_register_fail[] __initdata =
+	KERN_ERR "error registering line discipline: %d\n";
+static char hdlc_init_fail[] __initdata =
+	KERN_INFO "N_HDLC: init failure %d\n";
+
+static int __init n_hdlc_init(void)
+{
+	int status;
+
+	/* range check maxframe arg */
+	if (maxframe < 4096)
+		maxframe = 4096;
+	else if (maxframe > 65535)
+		maxframe = 65535;
+
+	printk(hdlc_banner, maxframe);
+
+	status = tty_register_ldisc(N_HDLC, &n_hdlc_ldisc);
+	if (!status)
+		printk(hdlc_register_ok);
+	else
+		printk(hdlc_register_fail, status);
+
+	if (status)
+		printk(hdlc_init_fail, status);
+	return status;
+	
+}	/* end of init_module() */
+
+static char hdlc_unregister_ok[] __exitdata =
+	KERN_INFO "N_HDLC: line discipline unregistered\n";
+static char hdlc_unregister_fail[] __exitdata =
+	KERN_ERR "N_HDLC: can't unregister line discipline (err = %d)\n";
+
+static void __exit n_hdlc_exit(void)
+{
+	/* Release tty registration of line discipline */
+	int status = tty_unregister_ldisc(N_HDLC);
+
+	if (status)
+		printk(hdlc_unregister_fail, status);
+	else
+		printk(hdlc_unregister_ok);
+}
+
+module_init(n_hdlc_init);
+module_exit(n_hdlc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul Fulghum paulkf@microgate.com");
+module_param(debuglevel, int, 0);
+module_param(maxframe, int, 0);
+MODULE_ALIAS_LDISC(N_HDLC);
diff --git a/drivers/tty/n_r3964.c b/drivers/tty/n_r3964.c
new file mode 100644
index 0000000..88dda0c
--- /dev/null
+++ b/drivers/tty/n_r3964.c
@@ -0,0 +1,1264 @@
+/* r3964 linediscipline for linux
+ *
+ * -----------------------------------------------------------
+ * Copyright by 
+ * Philips Automation Projects
+ * Kassel (Germany)
+ * -----------------------------------------------------------
+ * This software may be used and distributed according to the terms of
+ * the GNU General Public License, incorporated herein by reference.
+ *
+ * Author:
+ * L. Haag
+ *
+ * $Log: n_r3964.c,v $
+ * Revision 1.10  2001/03/18 13:02:24  dwmw2
+ * Fix timer usage, use spinlocks properly.
+ *
+ * Revision 1.9  2001/03/18 12:52:14  dwmw2
+ * Merge changes in 2.4.2
+ *
+ * Revision 1.8  2000/03/23 14:14:54  dwmw2
+ * Fix race in sleeping in r3964_read()
+ *
+ * Revision 1.7  1999/28/08 11:41:50  dwmw2
+ * Port to 2.3 kernel
+ *
+ * Revision 1.6  1998/09/30 00:40:40  dwmw2
+ * Fixed compilation on 2.0.x kernels
+ * Updated to newly registered tty-ldisc number 9
+ *
+ * Revision 1.5  1998/09/04 21:57:36  dwmw2
+ * Signal handling bug fixes, port to 2.1.x.
+ *
+ * Revision 1.4  1998/04/02 20:26:59  lhaag
+ * select, blocking, ...
+ *
+ * Revision 1.3  1998/02/12 18:58:43  root
+ * fixed some memory leaks
+ * calculation of checksum characters
+ *
+ * Revision 1.2  1998/02/07 13:03:34  root
+ * ioctl read_telegram
+ *
+ * Revision 1.1  1998/02/06 19:21:03  root
+ * Initial revision
+ *
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/in.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/tty.h>
+#include <linux/errno.h>
+#include <linux/string.h>	/* used in new tty drivers */
+#include <linux/signal.h>	/* used in new tty drivers */
+#include <linux/ioctl.h>
+#include <linux/n_r3964.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+
+/*#define DEBUG_QUEUE*/
+
+/* Log successful handshake and protocol operations  */
+/*#define DEBUG_PROTO_S*/
+
+/* Log handshake and protocol errors: */
+/*#define DEBUG_PROTO_E*/
+
+/* Log Linediscipline operations (open, close, read, write...): */
+/*#define DEBUG_LDISC*/
+
+/* Log module and memory operations (init, cleanup; kmalloc, kfree): */
+/*#define DEBUG_MODUL*/
+
+/* Macro helpers for debug output: */
+#define TRACE(format, args...) printk("r3964: " format "\n" , ## args)
+
+#ifdef DEBUG_MODUL
+#define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_M(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_PROTO_S
+#define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_PS(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_PROTO_E
+#define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_PE(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_LDISC
+#define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_L(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_QUEUE
+#define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_Q(fmt, arg...) do {} while (0)
+#endif
+static void add_tx_queue(struct r3964_info *, struct r3964_block_header *);
+static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code);
+static void put_char(struct r3964_info *pInfo, unsigned char ch);
+static void trigger_transmit(struct r3964_info *pInfo);
+static void retry_transmit(struct r3964_info *pInfo);
+static void transmit_block(struct r3964_info *pInfo);
+static void receive_char(struct r3964_info *pInfo, const unsigned char c);
+static void receive_error(struct r3964_info *pInfo, const char flag);
+static void on_timeout(unsigned long priv);
+static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg);
+static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
+		unsigned char __user * buf);
+static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
+		int error_code, struct r3964_block_header *pBlock);
+static struct r3964_message *remove_msg(struct r3964_info *pInfo,
+		struct r3964_client_info *pClient);
+static void remove_client_block(struct r3964_info *pInfo,
+		struct r3964_client_info *pClient);
+
+static int r3964_open(struct tty_struct *tty);
+static void r3964_close(struct tty_struct *tty);
+static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
+		unsigned char __user * buf, size_t nr);
+static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
+		const unsigned char *buf, size_t nr);
+static int r3964_ioctl(struct tty_struct *tty, struct file *file,
+		unsigned int cmd, unsigned long arg);
+static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old);
+static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
+		struct poll_table_struct *wait);
+static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+		char *fp, int count);
+
+static struct tty_ldisc_ops tty_ldisc_N_R3964 = {
+	.owner = THIS_MODULE,
+	.magic = TTY_LDISC_MAGIC,
+	.name = "R3964",
+	.open = r3964_open,
+	.close = r3964_close,
+	.read = r3964_read,
+	.write = r3964_write,
+	.ioctl = r3964_ioctl,
+	.set_termios = r3964_set_termios,
+	.poll = r3964_poll,
+	.receive_buf = r3964_receive_buf,
+};
+
+static void dump_block(const unsigned char *block, unsigned int length)
+{
+	unsigned int i, j;
+	char linebuf[16 * 3 + 1];
+
+	for (i = 0; i < length; i += 16) {
+		for (j = 0; (j < 16) && (j + i < length); j++) {
+			sprintf(linebuf + 3 * j, "%02x ", block[i + j]);
+		}
+		linebuf[3 * j] = '\0';
+		TRACE_PS("%s", linebuf);
+	}
+}
+
+/*************************************************************
+ * Driver initialisation
+ *************************************************************/
+
+/*************************************************************
+ * Module support routines
+ *************************************************************/
+
+static void __exit r3964_exit(void)
+{
+	int status;
+
+	TRACE_M("cleanup_module()");
+
+	status = tty_unregister_ldisc(N_R3964);
+
+	if (status != 0) {
+		printk(KERN_ERR "r3964: error unregistering linediscipline: "
+				"%d\n", status);
+	} else {
+		TRACE_L("linediscipline successfully unregistered");
+	}
+}
+
+static int __init r3964_init(void)
+{
+	int status;
+
+	printk("r3964: Philips r3964 Driver $Revision: 1.10 $\n");
+
+	/*
+	 * Register the tty line discipline
+	 */
+
+	status = tty_register_ldisc(N_R3964, &tty_ldisc_N_R3964);
+	if (status == 0) {
+		TRACE_L("line discipline %d registered", N_R3964);
+		TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags,
+			tty_ldisc_N_R3964.num);
+		TRACE_L("open=%p", tty_ldisc_N_R3964.open);
+		TRACE_L("tty_ldisc_N_R3964 = %p", &tty_ldisc_N_R3964);
+	} else {
+		printk(KERN_ERR "r3964: error registering line discipline: "
+				"%d\n", status);
+	}
+	return status;
+}
+
+module_init(r3964_init);
+module_exit(r3964_exit);
+
+/*************************************************************
+ * Protocol implementation routines
+ *************************************************************/
+
+static void add_tx_queue(struct r3964_info *pInfo,
+			 struct r3964_block_header *pHeader)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&pInfo->lock, flags);
+
+	pHeader->next = NULL;
+
+	if (pInfo->tx_last == NULL) {
+		pInfo->tx_first = pInfo->tx_last = pHeader;
+	} else {
+		pInfo->tx_last->next = pHeader;
+		pInfo->tx_last = pHeader;
+	}
+
+	spin_unlock_irqrestore(&pInfo->lock, flags);
+
+	TRACE_Q("add_tx_queue %p, length %d, tx_first = %p",
+		pHeader, pHeader->length, pInfo->tx_first);
+}
+
+static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
+{
+	struct r3964_block_header *pHeader;
+	unsigned long flags;
+#ifdef DEBUG_QUEUE
+	struct r3964_block_header *pDump;
+#endif
+
+	pHeader = pInfo->tx_first;
+
+	if (pHeader == NULL)
+		return;
+
+#ifdef DEBUG_QUEUE
+	printk("r3964: remove_from_tx_queue: %p, length %u - ",
+		pHeader, pHeader->length);
+	for (pDump = pHeader; pDump; pDump = pDump->next)
+		printk("%p ", pDump);
+	printk("\n");
+#endif
+
+	if (pHeader->owner) {
+		if (error_code) {
+			add_msg(pHeader->owner, R3964_MSG_ACK, 0,
+				error_code, NULL);
+		} else {
+			add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length,
+				error_code, NULL);
+		}
+		wake_up_interruptible(&pInfo->read_wait);
+	}
+
+	spin_lock_irqsave(&pInfo->lock, flags);
+
+	pInfo->tx_first = pHeader->next;
+	if (pInfo->tx_first == NULL) {
+		pInfo->tx_last = NULL;
+	}
+
+	spin_unlock_irqrestore(&pInfo->lock, flags);
+
+	kfree(pHeader);
+	TRACE_M("remove_from_tx_queue - kfree %p", pHeader);
+
+	TRACE_Q("remove_from_tx_queue: tx_first = %p, tx_last = %p",
+		pInfo->tx_first, pInfo->tx_last);
+}
+
+static void add_rx_queue(struct r3964_info *pInfo,
+			 struct r3964_block_header *pHeader)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&pInfo->lock, flags);
+
+	pHeader->next = NULL;
+
+	if (pInfo->rx_last == NULL) {
+		pInfo->rx_first = pInfo->rx_last = pHeader;
+	} else {
+		pInfo->rx_last->next = pHeader;
+		pInfo->rx_last = pHeader;
+	}
+	pInfo->blocks_in_rx_queue++;
+
+	spin_unlock_irqrestore(&pInfo->lock, flags);
+
+	TRACE_Q("add_rx_queue: %p, length = %d, rx_first = %p, count = %d",
+		pHeader, pHeader->length,
+		pInfo->rx_first, pInfo->blocks_in_rx_queue);
+}
+
+static void remove_from_rx_queue(struct r3964_info *pInfo,
+				 struct r3964_block_header *pHeader)
+{
+	unsigned long flags;
+	struct r3964_block_header *pFind;
+
+	if (pHeader == NULL)
+		return;
+
+	TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
+		pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
+	TRACE_Q("remove_from_rx_queue: %p, length %u",
+		pHeader, pHeader->length);
+
+	spin_lock_irqsave(&pInfo->lock, flags);
+
+	if (pInfo->rx_first == pHeader) {
+		/* Remove the first block in the linked list: */
+		pInfo->rx_first = pHeader->next;
+
+		if (pInfo->rx_first == NULL) {
+			pInfo->rx_last = NULL;
+		}
+		pInfo->blocks_in_rx_queue--;
+	} else {
+		/* Find block to remove: */
+		for (pFind = pInfo->rx_first; pFind; pFind = pFind->next) {
+			if (pFind->next == pHeader) {
+				/* Got it. */
+				pFind->next = pHeader->next;
+				pInfo->blocks_in_rx_queue--;
+				if (pFind->next == NULL) {
+					/* Oh, removed the last one! */
+					pInfo->rx_last = pFind;
+				}
+				break;
+			}
+		}
+	}
+
+	spin_unlock_irqrestore(&pInfo->lock, flags);
+
+	kfree(pHeader);
+	TRACE_M("remove_from_rx_queue - kfree %p", pHeader);
+
+	TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
+		pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
+}
+
+static void put_char(struct r3964_info *pInfo, unsigned char ch)
+{
+	struct tty_struct *tty = pInfo->tty;
+	/* FIXME: put_char should not be called from an IRQ */
+	tty_put_char(tty, ch);
+	pInfo->bcc ^= ch;
+}
+
+static void flush(struct r3964_info *pInfo)
+{
+	struct tty_struct *tty = pInfo->tty;
+
+	if (tty == NULL || tty->ops->flush_chars == NULL)
+		return;
+	tty->ops->flush_chars(tty);
+}
+
+static void trigger_transmit(struct r3964_info *pInfo)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&pInfo->lock, flags);
+
+	if ((pInfo->state == R3964_IDLE) && (pInfo->tx_first != NULL)) {
+		pInfo->state = R3964_TX_REQUEST;
+		pInfo->nRetry = 0;
+		pInfo->flags &= ~R3964_ERROR;
+		mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
+
+		spin_unlock_irqrestore(&pInfo->lock, flags);
+
+		TRACE_PS("trigger_transmit - sent STX");
+
+		put_char(pInfo, STX);
+		flush(pInfo);
+
+		pInfo->bcc = 0;
+	} else {
+		spin_unlock_irqrestore(&pInfo->lock, flags);
+	}
+}
+
+static void retry_transmit(struct r3964_info *pInfo)
+{
+	if (pInfo->nRetry < R3964_MAX_RETRIES) {
+		TRACE_PE("transmission failed. Retry #%d", pInfo->nRetry);
+		pInfo->bcc = 0;
+		put_char(pInfo, STX);
+		flush(pInfo);
+		pInfo->state = R3964_TX_REQUEST;
+		pInfo->nRetry++;
+		mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
+	} else {
+		TRACE_PE("transmission failed after %d retries",
+			 R3964_MAX_RETRIES);
+
+		remove_from_tx_queue(pInfo, R3964_TX_FAIL);
+
+		put_char(pInfo, NAK);
+		flush(pInfo);
+		pInfo->state = R3964_IDLE;
+
+		trigger_transmit(pInfo);
+	}
+}
+
+static void transmit_block(struct r3964_info *pInfo)
+{
+	struct tty_struct *tty = pInfo->tty;
+	struct r3964_block_header *pBlock = pInfo->tx_first;
+	int room = 0;
+
+	if (tty == NULL || pBlock == NULL) {
+		return;
+	}
+
+	room = tty_write_room(tty);
+
+	TRACE_PS("transmit_block %p, room %d, length %d",
+		 pBlock, room, pBlock->length);
+
+	while (pInfo->tx_position < pBlock->length) {
+		if (room < 2)
+			break;
+
+		if (pBlock->data[pInfo->tx_position] == DLE) {
+			/* send additional DLE char: */
+			put_char(pInfo, DLE);
+		}
+		put_char(pInfo, pBlock->data[pInfo->tx_position++]);
+
+		room--;
+	}
+
+	if ((pInfo->tx_position == pBlock->length) && (room >= 3)) {
+		put_char(pInfo, DLE);
+		put_char(pInfo, ETX);
+		if (pInfo->flags & R3964_BCC) {
+			put_char(pInfo, pInfo->bcc);
+		}
+		pInfo->state = R3964_WAIT_FOR_TX_ACK;
+		mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
+	}
+	flush(pInfo);
+}
+
+static void on_receive_block(struct r3964_info *pInfo)
+{
+	unsigned int length;
+	struct r3964_client_info *pClient;
+	struct r3964_block_header *pBlock;
+
+	length = pInfo->rx_position;
+
+	/* compare byte checksum characters: */
+	if (pInfo->flags & R3964_BCC) {
+		if (pInfo->bcc != pInfo->last_rx) {
+			TRACE_PE("checksum error - got %x but expected %x",
+				 pInfo->last_rx, pInfo->bcc);
+			pInfo->flags |= R3964_CHECKSUM;
+		}
+	}
+
+	/* check for errors (parity, overrun,...): */
+	if (pInfo->flags & R3964_ERROR) {
+		TRACE_PE("on_receive_block - transmission failed error %x",
+			 pInfo->flags & R3964_ERROR);
+
+		put_char(pInfo, NAK);
+		flush(pInfo);
+		if (pInfo->nRetry < R3964_MAX_RETRIES) {
+			pInfo->state = R3964_WAIT_FOR_RX_REPEAT;
+			pInfo->nRetry++;
+			mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC);
+		} else {
+			TRACE_PE("on_receive_block - failed after max retries");
+			pInfo->state = R3964_IDLE;
+		}
+		return;
+	}
+
+	/* received block; submit DLE: */
+	put_char(pInfo, DLE);
+	flush(pInfo);
+	del_timer_sync(&pInfo->tmr);
+	TRACE_PS(" rx success: got %d chars", length);
+
+	/* prepare struct r3964_block_header: */
+	pBlock = kmalloc(length + sizeof(struct r3964_block_header),
+			GFP_KERNEL);
+	TRACE_M("on_receive_block - kmalloc %p", pBlock);
+
+	if (pBlock == NULL)
+		return;
+
+	pBlock->length = length;
+	pBlock->data = ((unsigned char *)pBlock) +
+			sizeof(struct r3964_block_header);
+	pBlock->locks = 0;
+	pBlock->next = NULL;
+	pBlock->owner = NULL;
+
+	memcpy(pBlock->data, pInfo->rx_buf, length);
+
+	/* queue block into rx_queue: */
+	add_rx_queue(pInfo, pBlock);
+
+	/* notify attached client processes: */
+	for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
+		if (pClient->sig_flags & R3964_SIG_DATA) {
+			add_msg(pClient, R3964_MSG_DATA, length, R3964_OK,
+				pBlock);
+		}
+	}
+	wake_up_interruptible(&pInfo->read_wait);
+
+	pInfo->state = R3964_IDLE;
+
+	trigger_transmit(pInfo);
+}
+
+static void receive_char(struct r3964_info *pInfo, const unsigned char c)
+{
+	switch (pInfo->state) {
+	case R3964_TX_REQUEST:
+		if (c == DLE) {
+			TRACE_PS("TX_REQUEST - got DLE");
+
+			pInfo->state = R3964_TRANSMITTING;
+			pInfo->tx_position = 0;
+
+			transmit_block(pInfo);
+		} else if (c == STX) {
+			if (pInfo->nRetry == 0) {
+				TRACE_PE("TX_REQUEST - init conflict");
+				if (pInfo->priority == R3964_SLAVE) {
+					goto start_receiving;
+				}
+			} else {
+				TRACE_PE("TX_REQUEST - secondary init "
+					"conflict!? Switching to SLAVE mode "
+					"for next rx.");
+				goto start_receiving;
+			}
+		} else {
+			TRACE_PE("TX_REQUEST - char != DLE: %x", c);
+			retry_transmit(pInfo);
+		}
+		break;
+	case R3964_TRANSMITTING:
+		if (c == NAK) {
+			TRACE_PE("TRANSMITTING - got NAK");
+			retry_transmit(pInfo);
+		} else {
+			TRACE_PE("TRANSMITTING - got invalid char");
+
+			pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
+			mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
+		}
+		break;
+	case R3964_WAIT_FOR_TX_ACK:
+		if (c == DLE) {
+			TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
+			remove_from_tx_queue(pInfo, R3964_OK);
+
+			pInfo->state = R3964_IDLE;
+			trigger_transmit(pInfo);
+		} else {
+			retry_transmit(pInfo);
+		}
+		break;
+	case R3964_WAIT_FOR_RX_REPEAT:
+		/* FALLTHROUGH */
+	case R3964_IDLE:
+		if (c == STX) {
+			/* Prevent rx_queue from overflow: */
+			if (pInfo->blocks_in_rx_queue >=
+			    R3964_MAX_BLOCKS_IN_RX_QUEUE) {
+				TRACE_PE("IDLE - got STX but no space in "
+						"rx_queue!");
+				pInfo->state = R3964_WAIT_FOR_RX_BUF;
+				mod_timer(&pInfo->tmr,
+					  jiffies + R3964_TO_NO_BUF);
+				break;
+			}
+start_receiving:
+			/* Ok, start receiving: */
+			TRACE_PS("IDLE - got STX");
+			pInfo->rx_position = 0;
+			pInfo->last_rx = 0;
+			pInfo->flags &= ~R3964_ERROR;
+			pInfo->state = R3964_RECEIVING;
+			mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
+			pInfo->nRetry = 0;
+			put_char(pInfo, DLE);
+			flush(pInfo);
+			pInfo->bcc = 0;
+		}
+		break;
+	case R3964_RECEIVING:
+		if (pInfo->rx_position < RX_BUF_SIZE) {
+			pInfo->bcc ^= c;
+
+			if (c == DLE) {
+				if (pInfo->last_rx == DLE) {
+					pInfo->last_rx = 0;
+					goto char_to_buf;
+				}
+				pInfo->last_rx = DLE;
+				break;
+			} else if ((c == ETX) && (pInfo->last_rx == DLE)) {
+				if (pInfo->flags & R3964_BCC) {
+					pInfo->state = R3964_WAIT_FOR_BCC;
+					mod_timer(&pInfo->tmr,
+						  jiffies + R3964_TO_ZVZ);
+				} else {
+					on_receive_block(pInfo);
+				}
+			} else {
+				pInfo->last_rx = c;
+char_to_buf:
+				pInfo->rx_buf[pInfo->rx_position++] = c;
+				mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
+			}
+		}
+		/* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
+		break;
+	case R3964_WAIT_FOR_BCC:
+		pInfo->last_rx = c;
+		on_receive_block(pInfo);
+		break;
+	}
+}
+
+static void receive_error(struct r3964_info *pInfo, const char flag)
+{
+	switch (flag) {
+	case TTY_NORMAL:
+		break;
+	case TTY_BREAK:
+		TRACE_PE("received break");
+		pInfo->flags |= R3964_BREAK;
+		break;
+	case TTY_PARITY:
+		TRACE_PE("parity error");
+		pInfo->flags |= R3964_PARITY;
+		break;
+	case TTY_FRAME:
+		TRACE_PE("frame error");
+		pInfo->flags |= R3964_FRAME;
+		break;
+	case TTY_OVERRUN:
+		TRACE_PE("frame overrun");
+		pInfo->flags |= R3964_OVERRUN;
+		break;
+	default:
+		TRACE_PE("receive_error - unknown flag %d", flag);
+		pInfo->flags |= R3964_UNKNOWN;
+		break;
+	}
+}
+
+static void on_timeout(unsigned long priv)
+{
+	struct r3964_info *pInfo = (void *)priv;
+
+	switch (pInfo->state) {
+	case R3964_TX_REQUEST:
+		TRACE_PE("TX_REQUEST - timeout");
+		retry_transmit(pInfo);
+		break;
+	case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
+		put_char(pInfo, NAK);
+		flush(pInfo);
+		retry_transmit(pInfo);
+		break;
+	case R3964_WAIT_FOR_TX_ACK:
+		TRACE_PE("WAIT_FOR_TX_ACK - timeout");
+		retry_transmit(pInfo);
+		break;
+	case R3964_WAIT_FOR_RX_BUF:
+		TRACE_PE("WAIT_FOR_RX_BUF - timeout");
+		put_char(pInfo, NAK);
+		flush(pInfo);
+		pInfo->state = R3964_IDLE;
+		break;
+	case R3964_RECEIVING:
+		TRACE_PE("RECEIVING - timeout after %d chars",
+			 pInfo->rx_position);
+		put_char(pInfo, NAK);
+		flush(pInfo);
+		pInfo->state = R3964_IDLE;
+		break;
+	case R3964_WAIT_FOR_RX_REPEAT:
+		TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
+		pInfo->state = R3964_IDLE;
+		break;
+	case R3964_WAIT_FOR_BCC:
+		TRACE_PE("WAIT_FOR_BCC - timeout");
+		put_char(pInfo, NAK);
+		flush(pInfo);
+		pInfo->state = R3964_IDLE;
+		break;
+	}
+}
+
+static struct r3964_client_info *findClient(struct r3964_info *pInfo,
+		struct pid *pid)
+{
+	struct r3964_client_info *pClient;
+
+	for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
+		if (pClient->pid == pid) {
+			return pClient;
+		}
+	}
+	return NULL;
+}
+
+static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg)
+{
+	struct r3964_client_info *pClient;
+	struct r3964_client_info **ppClient;
+	struct r3964_message *pMsg;
+
+	if ((arg & R3964_SIG_ALL) == 0) {
+		/* Remove client from client list */
+		for (ppClient = &pInfo->firstClient; *ppClient;
+		     ppClient = &(*ppClient)->next) {
+			pClient = *ppClient;
+
+			if (pClient->pid == pid) {
+				TRACE_PS("removing client %d from client list",
+					 pid_nr(pid));
+				*ppClient = pClient->next;
+				while (pClient->msg_count) {
+					pMsg = remove_msg(pInfo, pClient);
+					if (pMsg) {
+						kfree(pMsg);
+						TRACE_M("enable_signals - msg "
+							"kfree %p", pMsg);
+					}
+				}
+				put_pid(pClient->pid);
+				kfree(pClient);
+				TRACE_M("enable_signals - kfree %p", pClient);
+				return 0;
+			}
+		}
+		return -EINVAL;
+	} else {
+		pClient = findClient(pInfo, pid);
+		if (pClient) {
+			/* update signal options */
+			pClient->sig_flags = arg;
+		} else {
+			/* add client to client list */
+			pClient = kmalloc(sizeof(struct r3964_client_info),
+					GFP_KERNEL);
+			TRACE_M("enable_signals - kmalloc %p", pClient);
+			if (pClient == NULL)
+				return -ENOMEM;
+
+			TRACE_PS("add client %d to client list", pid_nr(pid));
+			spin_lock_init(&pClient->lock);
+			pClient->sig_flags = arg;
+			pClient->pid = get_pid(pid);
+			pClient->next = pInfo->firstClient;
+			pClient->first_msg = NULL;
+			pClient->last_msg = NULL;
+			pClient->next_block_to_read = NULL;
+			pClient->msg_count = 0;
+			pInfo->firstClient = pClient;
+		}
+	}
+
+	return 0;
+}
+
+static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
+			 unsigned char __user * buf)
+{
+	struct r3964_client_info *pClient;
+	struct r3964_block_header *block;
+
+	if (!buf) {
+		return -EINVAL;
+	}
+
+	pClient = findClient(pInfo, pid);
+	if (pClient == NULL) {
+		return -EINVAL;
+	}
+
+	block = pClient->next_block_to_read;
+	if (!block) {
+		return 0;
+	} else {
+		if (copy_to_user(buf, block->data, block->length))
+			return -EFAULT;
+
+		remove_client_block(pInfo, pClient);
+		return block->length;
+	}
+
+	return -EINVAL;
+}
+
+static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
+		int error_code, struct r3964_block_header *pBlock)
+{
+	struct r3964_message *pMsg;
+	unsigned long flags;
+
+	if (pClient->msg_count < R3964_MAX_MSG_COUNT - 1) {
+queue_the_message:
+
+		pMsg = kmalloc(sizeof(struct r3964_message),
+				error_code ? GFP_ATOMIC : GFP_KERNEL);
+		TRACE_M("add_msg - kmalloc %p", pMsg);
+		if (pMsg == NULL) {
+			return;
+		}
+
+		spin_lock_irqsave(&pClient->lock, flags);
+
+		pMsg->msg_id = msg_id;
+		pMsg->arg = arg;
+		pMsg->error_code = error_code;
+		pMsg->block = pBlock;
+		pMsg->next = NULL;
+
+		if (pClient->last_msg == NULL) {
+			pClient->first_msg = pClient->last_msg = pMsg;
+		} else {
+			pClient->last_msg->next = pMsg;
+			pClient->last_msg = pMsg;
+		}
+
+		pClient->msg_count++;
+
+		if (pBlock != NULL) {
+			pBlock->locks++;
+		}
+		spin_unlock_irqrestore(&pClient->lock, flags);
+	} else {
+		if ((pClient->last_msg->msg_id == R3964_MSG_ACK)
+		    && (pClient->last_msg->error_code == R3964_OVERFLOW)) {
+			pClient->last_msg->arg++;
+			TRACE_PE("add_msg - inc prev OVERFLOW-msg");
+		} else {
+			msg_id = R3964_MSG_ACK;
+			arg = 0;
+			error_code = R3964_OVERFLOW;
+			pBlock = NULL;
+			TRACE_PE("add_msg - queue OVERFLOW-msg");
+			goto queue_the_message;
+		}
+	}
+	/* Send SIGIO signal to client process: */
+	if (pClient->sig_flags & R3964_USE_SIGIO) {
+		kill_pid(pClient->pid, SIGIO, 1);
+	}
+}
+
+static struct r3964_message *remove_msg(struct r3964_info *pInfo,
+					struct r3964_client_info *pClient)
+{
+	struct r3964_message *pMsg = NULL;
+	unsigned long flags;
+
+	if (pClient->first_msg) {
+		spin_lock_irqsave(&pClient->lock, flags);
+
+		pMsg = pClient->first_msg;
+		pClient->first_msg = pMsg->next;
+		if (pClient->first_msg == NULL) {
+			pClient->last_msg = NULL;
+		}
+
+		pClient->msg_count--;
+		if (pMsg->block) {
+			remove_client_block(pInfo, pClient);
+			pClient->next_block_to_read = pMsg->block;
+		}
+		spin_unlock_irqrestore(&pClient->lock, flags);
+	}
+	return pMsg;
+}
+
+static void remove_client_block(struct r3964_info *pInfo,
+				struct r3964_client_info *pClient)
+{
+	struct r3964_block_header *block;
+
+	TRACE_PS("remove_client_block PID %d", pid_nr(pClient->pid));
+
+	block = pClient->next_block_to_read;
+	if (block) {
+		block->locks--;
+		if (block->locks == 0) {
+			remove_from_rx_queue(pInfo, block);
+		}
+	}
+	pClient->next_block_to_read = NULL;
+}
+
+/*************************************************************
+ * Line discipline routines
+ *************************************************************/
+
+static int r3964_open(struct tty_struct *tty)
+{
+	struct r3964_info *pInfo;
+
+	TRACE_L("open");
+	TRACE_L("tty=%p, PID=%d, disc_data=%p",
+		tty, current->pid, tty->disc_data);
+
+	pInfo = kmalloc(sizeof(struct r3964_info), GFP_KERNEL);
+	TRACE_M("r3964_open - info kmalloc %p", pInfo);
+
+	if (!pInfo) {
+		printk(KERN_ERR "r3964: failed to alloc info structure\n");
+		return -ENOMEM;
+	}
+
+	pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
+	TRACE_M("r3964_open - rx_buf kmalloc %p", pInfo->rx_buf);
+
+	if (!pInfo->rx_buf) {
+		printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
+		kfree(pInfo);
+		TRACE_M("r3964_open - info kfree %p", pInfo);
+		return -ENOMEM;
+	}
+
+	pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
+	TRACE_M("r3964_open - tx_buf kmalloc %p", pInfo->tx_buf);
+
+	if (!pInfo->tx_buf) {
+		printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
+		kfree(pInfo->rx_buf);
+		TRACE_M("r3964_open - rx_buf kfree %p", pInfo->rx_buf);
+		kfree(pInfo);
+		TRACE_M("r3964_open - info kfree %p", pInfo);
+		return -ENOMEM;
+	}
+
+	spin_lock_init(&pInfo->lock);
+	pInfo->tty = tty;
+	init_waitqueue_head(&pInfo->read_wait);
+	pInfo->priority = R3964_MASTER;
+	pInfo->rx_first = pInfo->rx_last = NULL;
+	pInfo->tx_first = pInfo->tx_last = NULL;
+	pInfo->rx_position = 0;
+	pInfo->tx_position = 0;
+	pInfo->last_rx = 0;
+	pInfo->blocks_in_rx_queue = 0;
+	pInfo->firstClient = NULL;
+	pInfo->state = R3964_IDLE;
+	pInfo->flags = R3964_DEBUG;
+	pInfo->nRetry = 0;
+
+	tty->disc_data = pInfo;
+	tty->receive_room = 65536;
+
+	setup_timer(&pInfo->tmr, on_timeout, (unsigned long)pInfo);
+
+	return 0;
+}
+
+static void r3964_close(struct tty_struct *tty)
+{
+	struct r3964_info *pInfo = tty->disc_data;
+	struct r3964_client_info *pClient, *pNext;
+	struct r3964_message *pMsg;
+	struct r3964_block_header *pHeader, *pNextHeader;
+	unsigned long flags;
+
+	TRACE_L("close");
+
+	/*
+	 * Make sure that our task queue isn't activated.  If it
+	 * is, take it out of the linked list.
+	 */
+	del_timer_sync(&pInfo->tmr);
+
+	/* Remove client-structs and message queues: */
+	pClient = pInfo->firstClient;
+	while (pClient) {
+		pNext = pClient->next;
+		while (pClient->msg_count) {
+			pMsg = remove_msg(pInfo, pClient);
+			if (pMsg) {
+				kfree(pMsg);
+				TRACE_M("r3964_close - msg kfree %p", pMsg);
+			}
+		}
+		put_pid(pClient->pid);
+		kfree(pClient);
+		TRACE_M("r3964_close - client kfree %p", pClient);
+		pClient = pNext;
+	}
+	/* Remove jobs from tx_queue: */
+	spin_lock_irqsave(&pInfo->lock, flags);
+	pHeader = pInfo->tx_first;
+	pInfo->tx_first = pInfo->tx_last = NULL;
+	spin_unlock_irqrestore(&pInfo->lock, flags);
+
+	while (pHeader) {
+		pNextHeader = pHeader->next;
+		kfree(pHeader);
+		pHeader = pNextHeader;
+	}
+
+	/* Free buffers: */
+	wake_up_interruptible(&pInfo->read_wait);
+	kfree(pInfo->rx_buf);
+	TRACE_M("r3964_close - rx_buf kfree %p", pInfo->rx_buf);
+	kfree(pInfo->tx_buf);
+	TRACE_M("r3964_close - tx_buf kfree %p", pInfo->tx_buf);
+	kfree(pInfo);
+	TRACE_M("r3964_close - info kfree %p", pInfo);
+}
+
+static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
+			  unsigned char __user * buf, size_t nr)
+{
+	struct r3964_info *pInfo = tty->disc_data;
+	struct r3964_client_info *pClient;
+	struct r3964_message *pMsg;
+	struct r3964_client_message theMsg;
+	int ret;
+
+	TRACE_L("read()");
+
+	tty_lock();
+
+	pClient = findClient(pInfo, task_pid(current));
+	if (pClient) {
+		pMsg = remove_msg(pInfo, pClient);
+		if (pMsg == NULL) {
+			/* no messages available. */
+			if (file->f_flags & O_NONBLOCK) {
+				ret = -EAGAIN;
+				goto unlock;
+			}
+			/* block until there is a message: */
+			wait_event_interruptible_tty(pInfo->read_wait,
+					(pMsg = remove_msg(pInfo, pClient)));
+		}
+
+		/* If we still haven't got a message, we must have been signalled */
+
+		if (!pMsg) {
+			ret = -EINTR;
+			goto unlock;
+		}
+
+		/* deliver msg to client process: */
+		theMsg.msg_id = pMsg->msg_id;
+		theMsg.arg = pMsg->arg;
+		theMsg.error_code = pMsg->error_code;
+		ret = sizeof(struct r3964_client_message);
+
+		kfree(pMsg);
+		TRACE_M("r3964_read - msg kfree %p", pMsg);
+
+		if (copy_to_user(buf, &theMsg, ret)) {
+			ret = -EFAULT;
+			goto unlock;
+		}
+
+		TRACE_PS("read - return %d", ret);
+		goto unlock;
+	}
+	ret = -EPERM;
+unlock:
+	tty_unlock();
+	return ret;
+}
+
+static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
+			   const unsigned char *data, size_t count)
+{
+	struct r3964_info *pInfo = tty->disc_data;
+	struct r3964_block_header *pHeader;
+	struct r3964_client_info *pClient;
+	unsigned char *new_data;
+
+	TRACE_L("write request, %d characters", count);
+/* 
+ * Verify the pointers 
+ */
+
+	if (!pInfo)
+		return -EIO;
+
+/*
+ * Ensure that the caller does not wish to send too much.
+ */
+	if (count > R3964_MTU) {
+		if (pInfo->flags & R3964_DEBUG) {
+			TRACE_L(KERN_WARNING "r3964_write: truncating user "
+				"packet from %u to mtu %d", count, R3964_MTU);
+		}
+		count = R3964_MTU;
+	}
+/*
+ * Allocate a buffer for the data and copy it from the buffer with header prepended
+ */
+	new_data = kmalloc(count + sizeof(struct r3964_block_header),
+			GFP_KERNEL);
+	TRACE_M("r3964_write - kmalloc %p", new_data);
+	if (new_data == NULL) {
+		if (pInfo->flags & R3964_DEBUG) {
+			printk(KERN_ERR "r3964_write: no memory\n");
+		}
+		return -ENOSPC;
+	}
+
+	pHeader = (struct r3964_block_header *)new_data;
+	pHeader->data = new_data + sizeof(struct r3964_block_header);
+	pHeader->length = count;
+	pHeader->locks = 0;
+	pHeader->owner = NULL;
+
+	tty_lock();
+
+	pClient = findClient(pInfo, task_pid(current));
+	if (pClient) {
+		pHeader->owner = pClient;
+	}
+
+	memcpy(pHeader->data, data, count);	/* We already verified this */
+
+	if (pInfo->flags & R3964_DEBUG) {
+		dump_block(pHeader->data, count);
+	}
+
+/*
+ * Add buffer to transmit-queue:
+ */
+	add_tx_queue(pInfo, pHeader);
+	trigger_transmit(pInfo);
+
+	tty_unlock();
+
+	return 0;
+}
+
+static int r3964_ioctl(struct tty_struct *tty, struct file *file,
+		unsigned int cmd, unsigned long arg)
+{
+	struct r3964_info *pInfo = tty->disc_data;
+	if (pInfo == NULL)
+		return -EINVAL;
+	switch (cmd) {
+	case R3964_ENABLE_SIGNALS:
+		return enable_signals(pInfo, task_pid(current), arg);
+	case R3964_SETPRIORITY:
+		if (arg < R3964_MASTER || arg > R3964_SLAVE)
+			return -EINVAL;
+		pInfo->priority = arg & 0xff;
+		return 0;
+	case R3964_USE_BCC:
+		if (arg)
+			pInfo->flags |= R3964_BCC;
+		else
+			pInfo->flags &= ~R3964_BCC;
+		return 0;
+	case R3964_READ_TELEGRAM:
+		return read_telegram(pInfo, task_pid(current),
+				(unsigned char __user *)arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old)
+{
+	TRACE_L("set_termios");
+}
+
+/* Called without the kernel lock held - fine */
+static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
+			struct poll_table_struct *wait)
+{
+	struct r3964_info *pInfo = tty->disc_data;
+	struct r3964_client_info *pClient;
+	struct r3964_message *pMsg = NULL;
+	unsigned long flags;
+	int result = POLLOUT;
+
+	TRACE_L("POLL");
+
+	pClient = findClient(pInfo, task_pid(current));
+	if (pClient) {
+		poll_wait(file, &pInfo->read_wait, wait);
+		spin_lock_irqsave(&pInfo->lock, flags);
+		pMsg = pClient->first_msg;
+		spin_unlock_irqrestore(&pInfo->lock, flags);
+		if (pMsg)
+			result |= POLLIN | POLLRDNORM;
+	} else {
+		result = -EINVAL;
+	}
+	return result;
+}
+
+static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+			char *fp, int count)
+{
+	struct r3964_info *pInfo = tty->disc_data;
+	const unsigned char *p;
+	char *f, flags = 0;
+	int i;
+
+	for (i = count, p = cp, f = fp; i; i--, p++) {
+		if (f)
+			flags = *f++;
+		if (flags == TTY_NORMAL) {
+			receive_char(pInfo, *p);
+		} else {
+			receive_error(pInfo, flags);
+		}
+
+	}
+}
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_LDISC(N_R3964);
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
new file mode 100644
index 0000000..428f4fe
--- /dev/null
+++ b/drivers/tty/n_tty.c
@@ -0,0 +1,2121 @@
+/*
+ * n_tty.c --- implements the N_TTY line discipline.
+ *
+ * This code used to be in tty_io.c, but things are getting hairy
+ * enough that it made sense to split things off.  (The N_TTY
+ * processing has changed so much that it's hardly recognizable,
+ * anyway...)
+ *
+ * Note that the open routine for N_TTY is guaranteed never to return
+ * an error.  This is because Linux will fall back to setting a line
+ * to N_TTY if it can not switch to any other line discipline.
+ *
+ * Written by Theodore Ts'o, Copyright 1994.
+ *
+ * This file also contains code originally written by Linus Torvalds,
+ * Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994.
+ *
+ * This file may be redistributed under the terms of the GNU General Public
+ * License.
+ *
+ * Reduced memory usage for older ARM systems  - Russell King.
+ *
+ * 2000/01/20   Fixed SMP locking on put_tty_queue using bits of
+ *		the patch by Andrew J. Kroll <ag784@freenet.buffalo.edu>
+ *		who actually finally proved there really was a race.
+ *
+ * 2002/03/18   Implemented n_tty_wakeup to send SIGIO POLL_OUTs to
+ *		waiting writing processes-Sapan Bhatia <sapan@corewars.org>.
+ *		Also fixed a bug in BLOCKING mode where n_tty_write returns
+ *		EAGAIN
+ */
+
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/timer.h>
+#include <linux/ctype.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/bitops.h>
+#include <linux/audit.h>
+#include <linux/file.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+
+#include <asm/system.h>
+
+/* number of characters left in xmit buffer before select has we have room */
+#define WAKEUP_CHARS 256
+
+/*
+ * This defines the low- and high-watermarks for throttling and
+ * unthrottling the TTY driver.  These watermarks are used for
+ * controlling the space in the read buffer.
+ */
+#define TTY_THRESHOLD_THROTTLE		128 /* now based on remaining room */
+#define TTY_THRESHOLD_UNTHROTTLE 	128
+
+/*
+ * Special byte codes used in the echo buffer to represent operations
+ * or special handling of characters.  Bytes in the echo buffer that
+ * are not part of such special blocks are treated as normal character
+ * codes.
+ */
+#define ECHO_OP_START 0xff
+#define ECHO_OP_MOVE_BACK_COL 0x80
+#define ECHO_OP_SET_CANON_COL 0x81
+#define ECHO_OP_ERASE_TAB 0x82
+
+static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
+			       unsigned char __user *ptr)
+{
+	tty_audit_add_data(tty, &x, 1);
+	return put_user(x, ptr);
+}
+
+/**
+ *	n_tty_set__room	-	receive space
+ *	@tty: terminal
+ *
+ *	Called by the driver to find out how much data it is
+ *	permitted to feed to the line discipline without any being lost
+ *	and thus to manage flow control. Not serialized. Answers for the
+ *	"instant".
+ */
+
+static void n_tty_set_room(struct tty_struct *tty)
+{
+	/* tty->read_cnt is not read locked ? */
+	int	left = N_TTY_BUF_SIZE - tty->read_cnt - 1;
+
+	/*
+	 * If we are doing input canonicalization, and there are no
+	 * pending newlines, let characters through without limit, so
+	 * that erase characters will be handled.  Other excess
+	 * characters will be beeped.
+	 */
+	if (left <= 0)
+		left = tty->icanon && !tty->canon_data;
+	tty->receive_room = left;
+}
+
+static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty)
+{
+	if (tty->read_cnt < N_TTY_BUF_SIZE) {
+		tty->read_buf[tty->read_head] = c;
+		tty->read_head = (tty->read_head + 1) & (N_TTY_BUF_SIZE-1);
+		tty->read_cnt++;
+	}
+}
+
+/**
+ *	put_tty_queue		-	add character to tty
+ *	@c: character
+ *	@tty: tty device
+ *
+ *	Add a character to the tty read_buf queue. This is done under the
+ *	read_lock to serialize character addition and also to protect us
+ *	against parallel reads or flushes
+ */
+
+static void put_tty_queue(unsigned char c, struct tty_struct *tty)
+{
+	unsigned long flags;
+	/*
+	 *	The problem of stomping on the buffers ends here.
+	 *	Why didn't anyone see this one coming? --AJK
+	*/
+	spin_lock_irqsave(&tty->read_lock, flags);
+	put_tty_queue_nolock(c, tty);
+	spin_unlock_irqrestore(&tty->read_lock, flags);
+}
+
+/**
+ *	check_unthrottle	-	allow new receive data
+ *	@tty; tty device
+ *
+ *	Check whether to call the driver unthrottle functions
+ *
+ *	Can sleep, may be called under the atomic_read_lock mutex but
+ *	this is not guaranteed.
+ */
+static void check_unthrottle(struct tty_struct *tty)
+{
+	if (tty->count)
+		tty_unthrottle(tty);
+}
+
+/**
+ *	reset_buffer_flags	-	reset buffer state
+ *	@tty: terminal to reset
+ *
+ *	Reset the read buffer counters, clear the flags,
+ *	and make sure the driver is unthrottled. Called
+ *	from n_tty_open() and n_tty_flush_buffer().
+ *
+ *	Locking: tty_read_lock for read fields.
+ */
+
+static void reset_buffer_flags(struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tty->read_lock, flags);
+	tty->read_head = tty->read_tail = tty->read_cnt = 0;
+	spin_unlock_irqrestore(&tty->read_lock, flags);
+
+	mutex_lock(&tty->echo_lock);
+	tty->echo_pos = tty->echo_cnt = tty->echo_overrun = 0;
+	mutex_unlock(&tty->echo_lock);
+
+	tty->canon_head = tty->canon_data = tty->erasing = 0;
+	memset(&tty->read_flags, 0, sizeof tty->read_flags);
+	n_tty_set_room(tty);
+	check_unthrottle(tty);
+}
+
+/**
+ *	n_tty_flush_buffer	-	clean input queue
+ *	@tty:	terminal device
+ *
+ *	Flush the input buffer. Called when the line discipline is
+ *	being closed, when the tty layer wants the buffer flushed (eg
+ *	at hangup) or when the N_TTY line discipline internally has to
+ *	clean the pending queue (for example some signals).
+ *
+ *	Locking: ctrl_lock, read_lock.
+ */
+
+static void n_tty_flush_buffer(struct tty_struct *tty)
+{
+	unsigned long flags;
+	/* clear everything and unthrottle the driver */
+	reset_buffer_flags(tty);
+
+	if (!tty->link)
+		return;
+
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	if (tty->link->packet) {
+		tty->ctrl_status |= TIOCPKT_FLUSHREAD;
+		wake_up_interruptible(&tty->link->read_wait);
+	}
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+}
+
+/**
+ *	n_tty_chars_in_buffer	-	report available bytes
+ *	@tty: tty device
+ *
+ *	Report the number of characters buffered to be delivered to user
+ *	at this instant in time.
+ *
+ *	Locking: read_lock
+ */
+
+static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
+{
+	unsigned long flags;
+	ssize_t n = 0;
+
+	spin_lock_irqsave(&tty->read_lock, flags);
+	if (!tty->icanon) {
+		n = tty->read_cnt;
+	} else if (tty->canon_data) {
+		n = (tty->canon_head > tty->read_tail) ?
+			tty->canon_head - tty->read_tail :
+			tty->canon_head + (N_TTY_BUF_SIZE - tty->read_tail);
+	}
+	spin_unlock_irqrestore(&tty->read_lock, flags);
+	return n;
+}
+
+/**
+ *	is_utf8_continuation	-	utf8 multibyte check
+ *	@c: byte to check
+ *
+ *	Returns true if the utf8 character 'c' is a multibyte continuation
+ *	character. We use this to correctly compute the on screen size
+ *	of the character when printing
+ */
+
+static inline int is_utf8_continuation(unsigned char c)
+{
+	return (c & 0xc0) == 0x80;
+}
+
+/**
+ *	is_continuation		-	multibyte check
+ *	@c: byte to check
+ *
+ *	Returns true if the utf8 character 'c' is a multibyte continuation
+ *	character and the terminal is in unicode mode.
+ */
+
+static inline int is_continuation(unsigned char c, struct tty_struct *tty)
+{
+	return I_IUTF8(tty) && is_utf8_continuation(c);
+}
+
+/**
+ *	do_output_char			-	output one character
+ *	@c: character (or partial unicode symbol)
+ *	@tty: terminal device
+ *	@space: space available in tty driver write buffer
+ *
+ *	This is a helper function that handles one output character
+ *	(including special characters like TAB, CR, LF, etc.),
+ *	doing OPOST processing and putting the results in the
+ *	tty driver's write buffer.
+ *
+ *	Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY
+ *	and NLDLY.  They simply aren't relevant in the world today.
+ *	If you ever need them, add them here.
+ *
+ *	Returns the number of bytes of buffer space used or -1 if
+ *	no space left.
+ *
+ *	Locking: should be called under the output_lock to protect
+ *		 the column state and space left in the buffer
+ */
+
+static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
+{
+	int	spaces;
+
+	if (!space)
+		return -1;
+
+	switch (c) {
+	case '\n':
+		if (O_ONLRET(tty))
+			tty->column = 0;
+		if (O_ONLCR(tty)) {
+			if (space < 2)
+				return -1;
+			tty->canon_column = tty->column = 0;
+			tty->ops->write(tty, "\r\n", 2);
+			return 2;
+		}
+		tty->canon_column = tty->column;
+		break;
+	case '\r':
+		if (O_ONOCR(tty) && tty->column == 0)
+			return 0;
+		if (O_OCRNL(tty)) {
+			c = '\n';
+			if (O_ONLRET(tty))
+				tty->canon_column = tty->column = 0;
+			break;
+		}
+		tty->canon_column = tty->column = 0;
+		break;
+	case '\t':
+		spaces = 8 - (tty->column & 7);
+		if (O_TABDLY(tty) == XTABS) {
+			if (space < spaces)
+				return -1;
+			tty->column += spaces;
+			tty->ops->write(tty, "        ", spaces);
+			return spaces;
+		}
+		tty->column += spaces;
+		break;
+	case '\b':
+		if (tty->column > 0)
+			tty->column--;
+		break;
+	default:
+		if (!iscntrl(c)) {
+			if (O_OLCUC(tty))
+				c = toupper(c);
+			if (!is_continuation(c, tty))
+				tty->column++;
+		}
+		break;
+	}
+
+	tty_put_char(tty, c);
+	return 1;
+}
+
+/**
+ *	process_output			-	output post processor
+ *	@c: character (or partial unicode symbol)
+ *	@tty: terminal device
+ *
+ *	Output one character with OPOST processing.
+ *	Returns -1 when the output device is full and the character
+ *	must be retried.
+ *
+ *	Locking: output_lock to protect column state and space left
+ *		 (also, this is called from n_tty_write under the
+ *		  tty layer write lock)
+ */
+
+static int process_output(unsigned char c, struct tty_struct *tty)
+{
+	int	space, retval;
+
+	mutex_lock(&tty->output_lock);
+
+	space = tty_write_room(tty);
+	retval = do_output_char(c, tty, space);
+
+	mutex_unlock(&tty->output_lock);
+	if (retval < 0)
+		return -1;
+	else
+		return 0;
+}
+
+/**
+ *	process_output_block		-	block post processor
+ *	@tty: terminal device
+ *	@buf: character buffer
+ *	@nr: number of bytes to output
+ *
+ *	Output a block of characters with OPOST processing.
+ *	Returns the number of characters output.
+ *
+ *	This path is used to speed up block console writes, among other
+ *	things when processing blocks of output data. It handles only
+ *	the simple cases normally found and helps to generate blocks of
+ *	symbols for the console driver and thus improve performance.
+ *
+ *	Locking: output_lock to protect column state and space left
+ *		 (also, this is called from n_tty_write under the
+ *		  tty layer write lock)
+ */
+
+static ssize_t process_output_block(struct tty_struct *tty,
+				    const unsigned char *buf, unsigned int nr)
+{
+	int	space;
+	int 	i;
+	const unsigned char *cp;
+
+	mutex_lock(&tty->output_lock);
+
+	space = tty_write_room(tty);
+	if (!space) {
+		mutex_unlock(&tty->output_lock);
+		return 0;
+	}
+	if (nr > space)
+		nr = space;
+
+	for (i = 0, cp = buf; i < nr; i++, cp++) {
+		unsigned char c = *cp;
+
+		switch (c) {
+		case '\n':
+			if (O_ONLRET(tty))
+				tty->column = 0;
+			if (O_ONLCR(tty))
+				goto break_out;
+			tty->canon_column = tty->column;
+			break;
+		case '\r':
+			if (O_ONOCR(tty) && tty->column == 0)
+				goto break_out;
+			if (O_OCRNL(tty))
+				goto break_out;
+			tty->canon_column = tty->column = 0;
+			break;
+		case '\t':
+			goto break_out;
+		case '\b':
+			if (tty->column > 0)
+				tty->column--;
+			break;
+		default:
+			if (!iscntrl(c)) {
+				if (O_OLCUC(tty))
+					goto break_out;
+				if (!is_continuation(c, tty))
+					tty->column++;
+			}
+			break;
+		}
+	}
+break_out:
+	i = tty->ops->write(tty, buf, i);
+
+	mutex_unlock(&tty->output_lock);
+	return i;
+}
+
+/**
+ *	process_echoes	-	write pending echo characters
+ *	@tty: terminal device
+ *
+ *	Write previously buffered echo (and other ldisc-generated)
+ *	characters to the tty.
+ *
+ *	Characters generated by the ldisc (including echoes) need to
+ *	be buffered because the driver's write buffer can fill during
+ *	heavy program output.  Echoing straight to the driver will
+ *	often fail under these conditions, causing lost characters and
+ *	resulting mismatches of ldisc state information.
+ *
+ *	Since the ldisc state must represent the characters actually sent
+ *	to the driver at the time of the write, operations like certain
+ *	changes in column state are also saved in the buffer and executed
+ *	here.
+ *
+ *	A circular fifo buffer is used so that the most recent characters
+ *	are prioritized.  Also, when control characters are echoed with a
+ *	prefixed "^", the pair is treated atomically and thus not separated.
+ *
+ *	Locking: output_lock to protect column state and space left,
+ *		 echo_lock to protect the echo buffer
+ */
+
+static void process_echoes(struct tty_struct *tty)
+{
+	int	space, nr;
+	unsigned char c;
+	unsigned char *cp, *buf_end;
+
+	if (!tty->echo_cnt)
+		return;
+
+	mutex_lock(&tty->output_lock);
+	mutex_lock(&tty->echo_lock);
+
+	space = tty_write_room(tty);
+
+	buf_end = tty->echo_buf + N_TTY_BUF_SIZE;
+	cp = tty->echo_buf + tty->echo_pos;
+	nr = tty->echo_cnt;
+	while (nr > 0) {
+		c = *cp;
+		if (c == ECHO_OP_START) {
+			unsigned char op;
+			unsigned char *opp;
+			int no_space_left = 0;
+
+			/*
+			 * If the buffer byte is the start of a multi-byte
+			 * operation, get the next byte, which is either the
+			 * op code or a control character value.
+			 */
+			opp = cp + 1;
+			if (opp == buf_end)
+				opp -= N_TTY_BUF_SIZE;
+			op = *opp;
+
+			switch (op) {
+				unsigned int num_chars, num_bs;
+
+			case ECHO_OP_ERASE_TAB:
+				if (++opp == buf_end)
+					opp -= N_TTY_BUF_SIZE;
+				num_chars = *opp;
+
+				/*
+				 * Determine how many columns to go back
+				 * in order to erase the tab.
+				 * This depends on the number of columns
+				 * used by other characters within the tab
+				 * area.  If this (modulo 8) count is from
+				 * the start of input rather than from a
+				 * previous tab, we offset by canon column.
+				 * Otherwise, tab spacing is normal.
+				 */
+				if (!(num_chars & 0x80))
+					num_chars += tty->canon_column;
+				num_bs = 8 - (num_chars & 7);
+
+				if (num_bs > space) {
+					no_space_left = 1;
+					break;
+				}
+				space -= num_bs;
+				while (num_bs--) {
+					tty_put_char(tty, '\b');
+					if (tty->column > 0)
+						tty->column--;
+				}
+				cp += 3;
+				nr -= 3;
+				break;
+
+			case ECHO_OP_SET_CANON_COL:
+				tty->canon_column = tty->column;
+				cp += 2;
+				nr -= 2;
+				break;
+
+			case ECHO_OP_MOVE_BACK_COL:
+				if (tty->column > 0)
+					tty->column--;
+				cp += 2;
+				nr -= 2;
+				break;
+
+			case ECHO_OP_START:
+				/* This is an escaped echo op start code */
+				if (!space) {
+					no_space_left = 1;
+					break;
+				}
+				tty_put_char(tty, ECHO_OP_START);
+				tty->column++;
+				space--;
+				cp += 2;
+				nr -= 2;
+				break;
+
+			default:
+				/*
+				 * If the op is not a special byte code,
+				 * it is a ctrl char tagged to be echoed
+				 * as "^X" (where X is the letter
+				 * representing the control char).
+				 * Note that we must ensure there is
+				 * enough space for the whole ctrl pair.
+				 *
+				 */
+				if (space < 2) {
+					no_space_left = 1;
+					break;
+				}
+				tty_put_char(tty, '^');
+				tty_put_char(tty, op ^ 0100);
+				tty->column += 2;
+				space -= 2;
+				cp += 2;
+				nr -= 2;
+			}
+
+			if (no_space_left)
+				break;
+		} else {
+			if (O_OPOST(tty) &&
+			    !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
+				int retval = do_output_char(c, tty, space);
+				if (retval < 0)
+					break;
+				space -= retval;
+			} else {
+				if (!space)
+					break;
+				tty_put_char(tty, c);
+				space -= 1;
+			}
+			cp += 1;
+			nr -= 1;
+		}
+
+		/* When end of circular buffer reached, wrap around */
+		if (cp >= buf_end)
+			cp -= N_TTY_BUF_SIZE;
+	}
+
+	if (nr == 0) {
+		tty->echo_pos = 0;
+		tty->echo_cnt = 0;
+		tty->echo_overrun = 0;
+	} else {
+		int num_processed = tty->echo_cnt - nr;
+		tty->echo_pos += num_processed;
+		tty->echo_pos &= N_TTY_BUF_SIZE - 1;
+		tty->echo_cnt = nr;
+		if (num_processed > 0)
+			tty->echo_overrun = 0;
+	}
+
+	mutex_unlock(&tty->echo_lock);
+	mutex_unlock(&tty->output_lock);
+
+	if (tty->ops->flush_chars)
+		tty->ops->flush_chars(tty);
+}
+
+/**
+ *	add_echo_byte	-	add a byte to the echo buffer
+ *	@c: unicode byte to echo
+ *	@tty: terminal device
+ *
+ *	Add a character or operation byte to the echo buffer.
+ *
+ *	Should be called under the echo lock to protect the echo buffer.
+ */
+
+static void add_echo_byte(unsigned char c, struct tty_struct *tty)
+{
+	int	new_byte_pos;
+
+	if (tty->echo_cnt == N_TTY_BUF_SIZE) {
+		/* Circular buffer is already at capacity */
+		new_byte_pos = tty->echo_pos;
+
+		/*
+		 * Since the buffer start position needs to be advanced,
+		 * be sure to step by a whole operation byte group.
+		 */
+		if (tty->echo_buf[tty->echo_pos] == ECHO_OP_START) {
+			if (tty->echo_buf[(tty->echo_pos + 1) &
+					  (N_TTY_BUF_SIZE - 1)] ==
+						ECHO_OP_ERASE_TAB) {
+				tty->echo_pos += 3;
+				tty->echo_cnt -= 2;
+			} else {
+				tty->echo_pos += 2;
+				tty->echo_cnt -= 1;
+			}
+		} else {
+			tty->echo_pos++;
+		}
+		tty->echo_pos &= N_TTY_BUF_SIZE - 1;
+
+		tty->echo_overrun = 1;
+	} else {
+		new_byte_pos = tty->echo_pos + tty->echo_cnt;
+		new_byte_pos &= N_TTY_BUF_SIZE - 1;
+		tty->echo_cnt++;
+	}
+
+	tty->echo_buf[new_byte_pos] = c;
+}
+
+/**
+ *	echo_move_back_col	-	add operation to move back a column
+ *	@tty: terminal device
+ *
+ *	Add an operation to the echo buffer to move back one column.
+ *
+ *	Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_move_back_col(struct tty_struct *tty)
+{
+	mutex_lock(&tty->echo_lock);
+
+	add_echo_byte(ECHO_OP_START, tty);
+	add_echo_byte(ECHO_OP_MOVE_BACK_COL, tty);
+
+	mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ *	echo_set_canon_col	-	add operation to set the canon column
+ *	@tty: terminal device
+ *
+ *	Add an operation to the echo buffer to set the canon column
+ *	to the current column.
+ *
+ *	Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_set_canon_col(struct tty_struct *tty)
+{
+	mutex_lock(&tty->echo_lock);
+
+	add_echo_byte(ECHO_OP_START, tty);
+	add_echo_byte(ECHO_OP_SET_CANON_COL, tty);
+
+	mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ *	echo_erase_tab	-	add operation to erase a tab
+ *	@num_chars: number of character columns already used
+ *	@after_tab: true if num_chars starts after a previous tab
+ *	@tty: terminal device
+ *
+ *	Add an operation to the echo buffer to erase a tab.
+ *
+ *	Called by the eraser function, which knows how many character
+ *	columns have been used since either a previous tab or the start
+ *	of input.  This information will be used later, along with
+ *	canon column (if applicable), to go back the correct number
+ *	of columns.
+ *
+ *	Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_erase_tab(unsigned int num_chars, int after_tab,
+			   struct tty_struct *tty)
+{
+	mutex_lock(&tty->echo_lock);
+
+	add_echo_byte(ECHO_OP_START, tty);
+	add_echo_byte(ECHO_OP_ERASE_TAB, tty);
+
+	/* We only need to know this modulo 8 (tab spacing) */
+	num_chars &= 7;
+
+	/* Set the high bit as a flag if num_chars is after a previous tab */
+	if (after_tab)
+		num_chars |= 0x80;
+
+	add_echo_byte(num_chars, tty);
+
+	mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ *	echo_char_raw	-	echo a character raw
+ *	@c: unicode byte to echo
+ *	@tty: terminal device
+ *
+ *	Echo user input back onto the screen. This must be called only when
+ *	L_ECHO(tty) is true. Called from the driver receive_buf path.
+ *
+ *	This variant does not treat control characters specially.
+ *
+ *	Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_char_raw(unsigned char c, struct tty_struct *tty)
+{
+	mutex_lock(&tty->echo_lock);
+
+	if (c == ECHO_OP_START) {
+		add_echo_byte(ECHO_OP_START, tty);
+		add_echo_byte(ECHO_OP_START, tty);
+	} else {
+		add_echo_byte(c, tty);
+	}
+
+	mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ *	echo_char	-	echo a character
+ *	@c: unicode byte to echo
+ *	@tty: terminal device
+ *
+ *	Echo user input back onto the screen. This must be called only when
+ *	L_ECHO(tty) is true. Called from the driver receive_buf path.
+ *
+ *	This variant tags control characters to be echoed as "^X"
+ *	(where X is the letter representing the control char).
+ *
+ *	Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_char(unsigned char c, struct tty_struct *tty)
+{
+	mutex_lock(&tty->echo_lock);
+
+	if (c == ECHO_OP_START) {
+		add_echo_byte(ECHO_OP_START, tty);
+		add_echo_byte(ECHO_OP_START, tty);
+	} else {
+		if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t')
+			add_echo_byte(ECHO_OP_START, tty);
+		add_echo_byte(c, tty);
+	}
+
+	mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ *	finish_erasing		-	complete erase
+ *	@tty: tty doing the erase
+ */
+
+static inline void finish_erasing(struct tty_struct *tty)
+{
+	if (tty->erasing) {
+		echo_char_raw('/', tty);
+		tty->erasing = 0;
+	}
+}
+
+/**
+ *	eraser		-	handle erase function
+ *	@c: character input
+ *	@tty: terminal device
+ *
+ *	Perform erase and necessary output when an erase character is
+ *	present in the stream from the driver layer. Handles the complexities
+ *	of UTF-8 multibyte symbols.
+ *
+ *	Locking: read_lock for tty buffers
+ */
+
+static void eraser(unsigned char c, struct tty_struct *tty)
+{
+	enum { ERASE, WERASE, KILL } kill_type;
+	int head, seen_alnums, cnt;
+	unsigned long flags;
+
+	/* FIXME: locking needed ? */
+	if (tty->read_head == tty->canon_head) {
+		/* process_output('\a', tty); */ /* what do you think? */
+		return;
+	}
+	if (c == ERASE_CHAR(tty))
+		kill_type = ERASE;
+	else if (c == WERASE_CHAR(tty))
+		kill_type = WERASE;
+	else {
+		if (!L_ECHO(tty)) {
+			spin_lock_irqsave(&tty->read_lock, flags);
+			tty->read_cnt -= ((tty->read_head - tty->canon_head) &
+					  (N_TTY_BUF_SIZE - 1));
+			tty->read_head = tty->canon_head;
+			spin_unlock_irqrestore(&tty->read_lock, flags);
+			return;
+		}
+		if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) {
+			spin_lock_irqsave(&tty->read_lock, flags);
+			tty->read_cnt -= ((tty->read_head - tty->canon_head) &
+					  (N_TTY_BUF_SIZE - 1));
+			tty->read_head = tty->canon_head;
+			spin_unlock_irqrestore(&tty->read_lock, flags);
+			finish_erasing(tty);
+			echo_char(KILL_CHAR(tty), tty);
+			/* Add a newline if ECHOK is on and ECHOKE is off. */
+			if (L_ECHOK(tty))
+				echo_char_raw('\n', tty);
+			return;
+		}
+		kill_type = KILL;
+	}
+
+	seen_alnums = 0;
+	/* FIXME: Locking ?? */
+	while (tty->read_head != tty->canon_head) {
+		head = tty->read_head;
+
+		/* erase a single possibly multibyte character */
+		do {
+			head = (head - 1) & (N_TTY_BUF_SIZE-1);
+			c = tty->read_buf[head];
+		} while (is_continuation(c, tty) && head != tty->canon_head);
+
+		/* do not partially erase */
+		if (is_continuation(c, tty))
+			break;
+
+		if (kill_type == WERASE) {
+			/* Equivalent to BSD's ALTWERASE. */
+			if (isalnum(c) || c == '_')
+				seen_alnums++;
+			else if (seen_alnums)
+				break;
+		}
+		cnt = (tty->read_head - head) & (N_TTY_BUF_SIZE-1);
+		spin_lock_irqsave(&tty->read_lock, flags);
+		tty->read_head = head;
+		tty->read_cnt -= cnt;
+		spin_unlock_irqrestore(&tty->read_lock, flags);
+		if (L_ECHO(tty)) {
+			if (L_ECHOPRT(tty)) {
+				if (!tty->erasing) {
+					echo_char_raw('\\', tty);
+					tty->erasing = 1;
+				}
+				/* if cnt > 1, output a multi-byte character */
+				echo_char(c, tty);
+				while (--cnt > 0) {
+					head = (head+1) & (N_TTY_BUF_SIZE-1);
+					echo_char_raw(tty->read_buf[head], tty);
+					echo_move_back_col(tty);
+				}
+			} else if (kill_type == ERASE && !L_ECHOE(tty)) {
+				echo_char(ERASE_CHAR(tty), tty);
+			} else if (c == '\t') {
+				unsigned int num_chars = 0;
+				int after_tab = 0;
+				unsigned long tail = tty->read_head;
+
+				/*
+				 * Count the columns used for characters
+				 * since the start of input or after a
+				 * previous tab.
+				 * This info is used to go back the correct
+				 * number of columns.
+				 */
+				while (tail != tty->canon_head) {
+					tail = (tail-1) & (N_TTY_BUF_SIZE-1);
+					c = tty->read_buf[tail];
+					if (c == '\t') {
+						after_tab = 1;
+						break;
+					} else if (iscntrl(c)) {
+						if (L_ECHOCTL(tty))
+							num_chars += 2;
+					} else if (!is_continuation(c, tty)) {
+						num_chars++;
+					}
+				}
+				echo_erase_tab(num_chars, after_tab, tty);
+			} else {
+				if (iscntrl(c) && L_ECHOCTL(tty)) {
+					echo_char_raw('\b', tty);
+					echo_char_raw(' ', tty);
+					echo_char_raw('\b', tty);
+				}
+				if (!iscntrl(c) || L_ECHOCTL(tty)) {
+					echo_char_raw('\b', tty);
+					echo_char_raw(' ', tty);
+					echo_char_raw('\b', tty);
+				}
+			}
+		}
+		if (kill_type == ERASE)
+			break;
+	}
+	if (tty->read_head == tty->canon_head && L_ECHO(tty))
+		finish_erasing(tty);
+}
+
+/**
+ *	isig		-	handle the ISIG optio
+ *	@sig: signal
+ *	@tty: terminal
+ *	@flush: force flush
+ *
+ *	Called when a signal is being sent due to terminal input. This
+ *	may caus terminal flushing to take place according to the termios
+ *	settings and character used. Called from the driver receive_buf
+ *	path so serialized.
+ *
+ *	Locking: ctrl_lock, read_lock (both via flush buffer)
+ */
+
+static inline void isig(int sig, struct tty_struct *tty, int flush)
+{
+	if (tty->pgrp)
+		kill_pgrp(tty->pgrp, sig, 1);
+	if (flush || !L_NOFLSH(tty)) {
+		n_tty_flush_buffer(tty);
+		tty_driver_flush_buffer(tty);
+	}
+}
+
+/**
+ *	n_tty_receive_break	-	handle break
+ *	@tty: terminal
+ *
+ *	An RS232 break event has been hit in the incoming bitstream. This
+ *	can cause a variety of events depending upon the termios settings.
+ *
+ *	Called from the receive_buf path so single threaded.
+ */
+
+static inline void n_tty_receive_break(struct tty_struct *tty)
+{
+	if (I_IGNBRK(tty))
+		return;
+	if (I_BRKINT(tty)) {
+		isig(SIGINT, tty, 1);
+		return;
+	}
+	if (I_PARMRK(tty)) {
+		put_tty_queue('\377', tty);
+		put_tty_queue('\0', tty);
+	}
+	put_tty_queue('\0', tty);
+	wake_up_interruptible(&tty->read_wait);
+}
+
+/**
+ *	n_tty_receive_overrun	-	handle overrun reporting
+ *	@tty: terminal
+ *
+ *	Data arrived faster than we could process it. While the tty
+ *	driver has flagged this the bits that were missed are gone
+ *	forever.
+ *
+ *	Called from the receive_buf path so single threaded. Does not
+ *	need locking as num_overrun and overrun_time are function
+ *	private.
+ */
+
+static inline void n_tty_receive_overrun(struct tty_struct *tty)
+{
+	char buf[64];
+
+	tty->num_overrun++;
+	if (time_before(tty->overrun_time, jiffies - HZ) ||
+			time_after(tty->overrun_time, jiffies)) {
+		printk(KERN_WARNING "%s: %d input overrun(s)\n",
+			tty_name(tty, buf),
+			tty->num_overrun);
+		tty->overrun_time = jiffies;
+		tty->num_overrun = 0;
+	}
+}
+
+/**
+ *	n_tty_receive_parity_error	-	error notifier
+ *	@tty: terminal device
+ *	@c: character
+ *
+ *	Process a parity error and queue the right data to indicate
+ *	the error case if necessary. Locking as per n_tty_receive_buf.
+ */
+static inline void n_tty_receive_parity_error(struct tty_struct *tty,
+					      unsigned char c)
+{
+	if (I_IGNPAR(tty))
+		return;
+	if (I_PARMRK(tty)) {
+		put_tty_queue('\377', tty);
+		put_tty_queue('\0', tty);
+		put_tty_queue(c, tty);
+	} else	if (I_INPCK(tty))
+		put_tty_queue('\0', tty);
+	else
+		put_tty_queue(c, tty);
+	wake_up_interruptible(&tty->read_wait);
+}
+
+/**
+ *	n_tty_receive_char	-	perform processing
+ *	@tty: terminal device
+ *	@c: character
+ *
+ *	Process an individual character of input received from the driver.
+ *	This is serialized with respect to itself by the rules for the
+ *	driver above.
+ */
+
+static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
+{
+	unsigned long flags;
+	int parmrk;
+
+	if (tty->raw) {
+		put_tty_queue(c, tty);
+		return;
+	}
+
+	if (I_ISTRIP(tty))
+		c &= 0x7f;
+	if (I_IUCLC(tty) && L_IEXTEN(tty))
+		c = tolower(c);
+
+	if (L_EXTPROC(tty)) {
+		put_tty_queue(c, tty);
+		return;
+	}
+
+	if (tty->stopped && !tty->flow_stopped && I_IXON(tty) &&
+	    I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty) &&
+	    c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && c != SUSP_CHAR(tty)) {
+		start_tty(tty);
+		process_echoes(tty);
+	}
+
+	if (tty->closing) {
+		if (I_IXON(tty)) {
+			if (c == START_CHAR(tty)) {
+				start_tty(tty);
+				process_echoes(tty);
+			} else if (c == STOP_CHAR(tty))
+				stop_tty(tty);
+		}
+		return;
+	}
+
+	/*
+	 * If the previous character was LNEXT, or we know that this
+	 * character is not one of the characters that we'll have to
+	 * handle specially, do shortcut processing to speed things
+	 * up.
+	 */
+	if (!test_bit(c, tty->process_char_map) || tty->lnext) {
+		tty->lnext = 0;
+		parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
+		if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
+			/* beep if no space */
+			if (L_ECHO(tty))
+				process_output('\a', tty);
+			return;
+		}
+		if (L_ECHO(tty)) {
+			finish_erasing(tty);
+			/* Record the column of first canon char. */
+			if (tty->canon_head == tty->read_head)
+				echo_set_canon_col(tty);
+			echo_char(c, tty);
+			process_echoes(tty);
+		}
+		if (parmrk)
+			put_tty_queue(c, tty);
+		put_tty_queue(c, tty);
+		return;
+	}
+
+	if (I_IXON(tty)) {
+		if (c == START_CHAR(tty)) {
+			start_tty(tty);
+			process_echoes(tty);
+			return;
+		}
+		if (c == STOP_CHAR(tty)) {
+			stop_tty(tty);
+			return;
+		}
+	}
+
+	if (L_ISIG(tty)) {
+		int signal;
+		signal = SIGINT;
+		if (c == INTR_CHAR(tty))
+			goto send_signal;
+		signal = SIGQUIT;
+		if (c == QUIT_CHAR(tty))
+			goto send_signal;
+		signal = SIGTSTP;
+		if (c == SUSP_CHAR(tty)) {
+send_signal:
+			/*
+			 * Note that we do not use isig() here because we want
+			 * the order to be:
+			 * 1) flush, 2) echo, 3) signal
+			 */
+			if (!L_NOFLSH(tty)) {
+				n_tty_flush_buffer(tty);
+				tty_driver_flush_buffer(tty);
+			}
+			if (I_IXON(tty))
+				start_tty(tty);
+			if (L_ECHO(tty)) {
+				echo_char(c, tty);
+				process_echoes(tty);
+			}
+			if (tty->pgrp)
+				kill_pgrp(tty->pgrp, signal, 1);
+			return;
+		}
+	}
+
+	if (c == '\r') {
+		if (I_IGNCR(tty))
+			return;
+		if (I_ICRNL(tty))
+			c = '\n';
+	} else if (c == '\n' && I_INLCR(tty))
+		c = '\r';
+
+	if (tty->icanon) {
+		if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
+		    (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
+			eraser(c, tty);
+			process_echoes(tty);
+			return;
+		}
+		if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
+			tty->lnext = 1;
+			if (L_ECHO(tty)) {
+				finish_erasing(tty);
+				if (L_ECHOCTL(tty)) {
+					echo_char_raw('^', tty);
+					echo_char_raw('\b', tty);
+					process_echoes(tty);
+				}
+			}
+			return;
+		}
+		if (c == REPRINT_CHAR(tty) && L_ECHO(tty) &&
+		    L_IEXTEN(tty)) {
+			unsigned long tail = tty->canon_head;
+
+			finish_erasing(tty);
+			echo_char(c, tty);
+			echo_char_raw('\n', tty);
+			while (tail != tty->read_head) {
+				echo_char(tty->read_buf[tail], tty);
+				tail = (tail+1) & (N_TTY_BUF_SIZE-1);
+			}
+			process_echoes(tty);
+			return;
+		}
+		if (c == '\n') {
+			if (tty->read_cnt >= N_TTY_BUF_SIZE) {
+				if (L_ECHO(tty))
+					process_output('\a', tty);
+				return;
+			}
+			if (L_ECHO(tty) || L_ECHONL(tty)) {
+				echo_char_raw('\n', tty);
+				process_echoes(tty);
+			}
+			goto handle_newline;
+		}
+		if (c == EOF_CHAR(tty)) {
+			if (tty->read_cnt >= N_TTY_BUF_SIZE)
+				return;
+			if (tty->canon_head != tty->read_head)
+				set_bit(TTY_PUSH, &tty->flags);
+			c = __DISABLED_CHAR;
+			goto handle_newline;
+		}
+		if ((c == EOL_CHAR(tty)) ||
+		    (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
+			parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty))
+				 ? 1 : 0;
+			if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk)) {
+				if (L_ECHO(tty))
+					process_output('\a', tty);
+				return;
+			}
+			/*
+			 * XXX are EOL_CHAR and EOL2_CHAR echoed?!?
+			 */
+			if (L_ECHO(tty)) {
+				/* Record the column of first canon char. */
+				if (tty->canon_head == tty->read_head)
+					echo_set_canon_col(tty);
+				echo_char(c, tty);
+				process_echoes(tty);
+			}
+			/*
+			 * XXX does PARMRK doubling happen for
+			 * EOL_CHAR and EOL2_CHAR?
+			 */
+			if (parmrk)
+				put_tty_queue(c, tty);
+
+handle_newline:
+			spin_lock_irqsave(&tty->read_lock, flags);
+			set_bit(tty->read_head, tty->read_flags);
+			put_tty_queue_nolock(c, tty);
+			tty->canon_head = tty->read_head;
+			tty->canon_data++;
+			spin_unlock_irqrestore(&tty->read_lock, flags);
+			kill_fasync(&tty->fasync, SIGIO, POLL_IN);
+			if (waitqueue_active(&tty->read_wait))
+				wake_up_interruptible(&tty->read_wait);
+			return;
+		}
+	}
+
+	parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
+	if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
+		/* beep if no space */
+		if (L_ECHO(tty))
+			process_output('\a', tty);
+		return;
+	}
+	if (L_ECHO(tty)) {
+		finish_erasing(tty);
+		if (c == '\n')
+			echo_char_raw('\n', tty);
+		else {
+			/* Record the column of first canon char. */
+			if (tty->canon_head == tty->read_head)
+				echo_set_canon_col(tty);
+			echo_char(c, tty);
+		}
+		process_echoes(tty);
+	}
+
+	if (parmrk)
+		put_tty_queue(c, tty);
+
+	put_tty_queue(c, tty);
+}
+
+
+/**
+ *	n_tty_write_wakeup	-	asynchronous I/O notifier
+ *	@tty: tty device
+ *
+ *	Required for the ptys, serial driver etc. since processes
+ *	that attach themselves to the master and rely on ASYNC
+ *	IO must be woken up
+ */
+
+static void n_tty_write_wakeup(struct tty_struct *tty)
+{
+	if (tty->fasync && test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags))
+		kill_fasync(&tty->fasync, SIGIO, POLL_OUT);
+}
+
+/**
+ *	n_tty_receive_buf	-	data receive
+ *	@tty: terminal device
+ *	@cp: buffer
+ *	@fp: flag buffer
+ *	@count: characters
+ *
+ *	Called by the terminal driver when a block of characters has
+ *	been received. This function must be called from soft contexts
+ *	not from interrupt context. The driver is responsible for making
+ *	calls one at a time and in order (or using flush_to_ldisc)
+ */
+
+static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+			      char *fp, int count)
+{
+	const unsigned char *p;
+	char *f, flags = TTY_NORMAL;
+	int	i;
+	char	buf[64];
+	unsigned long cpuflags;
+
+	if (!tty->read_buf)
+		return;
+
+	if (tty->real_raw) {
+		spin_lock_irqsave(&tty->read_lock, cpuflags);
+		i = min(N_TTY_BUF_SIZE - tty->read_cnt,
+			N_TTY_BUF_SIZE - tty->read_head);
+		i = min(count, i);
+		memcpy(tty->read_buf + tty->read_head, cp, i);
+		tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
+		tty->read_cnt += i;
+		cp += i;
+		count -= i;
+
+		i = min(N_TTY_BUF_SIZE - tty->read_cnt,
+			N_TTY_BUF_SIZE - tty->read_head);
+		i = min(count, i);
+		memcpy(tty->read_buf + tty->read_head, cp, i);
+		tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
+		tty->read_cnt += i;
+		spin_unlock_irqrestore(&tty->read_lock, cpuflags);
+	} else {
+		for (i = count, p = cp, f = fp; i; i--, p++) {
+			if (f)
+				flags = *f++;
+			switch (flags) {
+			case TTY_NORMAL:
+				n_tty_receive_char(tty, *p);
+				break;
+			case TTY_BREAK:
+				n_tty_receive_break(tty);
+				break;
+			case TTY_PARITY:
+			case TTY_FRAME:
+				n_tty_receive_parity_error(tty, *p);
+				break;
+			case TTY_OVERRUN:
+				n_tty_receive_overrun(tty);
+				break;
+			default:
+				printk(KERN_ERR "%s: unknown flag %d\n",
+				       tty_name(tty, buf), flags);
+				break;
+			}
+		}
+		if (tty->ops->flush_chars)
+			tty->ops->flush_chars(tty);
+	}
+
+	n_tty_set_room(tty);
+
+	if ((!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) ||
+		L_EXTPROC(tty)) {
+		kill_fasync(&tty->fasync, SIGIO, POLL_IN);
+		if (waitqueue_active(&tty->read_wait))
+			wake_up_interruptible(&tty->read_wait);
+	}
+
+	/*
+	 * Check the remaining room for the input canonicalization
+	 * mode.  We don't want to throttle the driver if we're in
+	 * canonical mode and don't have a newline yet!
+	 */
+	if (tty->receive_room < TTY_THRESHOLD_THROTTLE)
+		tty_throttle(tty);
+}
+
+int is_ignored(int sig)
+{
+	return (sigismember(&current->blocked, sig) ||
+		current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
+}
+
+/**
+ *	n_tty_set_termios	-	termios data changed
+ *	@tty: terminal
+ *	@old: previous data
+ *
+ *	Called by the tty layer when the user changes termios flags so
+ *	that the line discipline can plan ahead. This function cannot sleep
+ *	and is protected from re-entry by the tty layer. The user is
+ *	guaranteed that this function will not be re-entered or in progress
+ *	when the ldisc is closed.
+ *
+ *	Locking: Caller holds tty->termios_mutex
+ */
+
+static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
+{
+	int canon_change = 1;
+	BUG_ON(!tty);
+
+	if (old)
+		canon_change = (old->c_lflag ^ tty->termios->c_lflag) & ICANON;
+	if (canon_change) {
+		memset(&tty->read_flags, 0, sizeof tty->read_flags);
+		tty->canon_head = tty->read_tail;
+		tty->canon_data = 0;
+		tty->erasing = 0;
+	}
+
+	if (canon_change && !L_ICANON(tty) && tty->read_cnt)
+		wake_up_interruptible(&tty->read_wait);
+
+	tty->icanon = (L_ICANON(tty) != 0);
+	if (test_bit(TTY_HW_COOK_IN, &tty->flags)) {
+		tty->raw = 1;
+		tty->real_raw = 1;
+		n_tty_set_room(tty);
+		return;
+	}
+	if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) ||
+	    I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) ||
+	    I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) ||
+	    I_PARMRK(tty)) {
+		memset(tty->process_char_map, 0, 256/8);
+
+		if (I_IGNCR(tty) || I_ICRNL(tty))
+			set_bit('\r', tty->process_char_map);
+		if (I_INLCR(tty))
+			set_bit('\n', tty->process_char_map);
+
+		if (L_ICANON(tty)) {
+			set_bit(ERASE_CHAR(tty), tty->process_char_map);
+			set_bit(KILL_CHAR(tty), tty->process_char_map);
+			set_bit(EOF_CHAR(tty), tty->process_char_map);
+			set_bit('\n', tty->process_char_map);
+			set_bit(EOL_CHAR(tty), tty->process_char_map);
+			if (L_IEXTEN(tty)) {
+				set_bit(WERASE_CHAR(tty),
+					tty->process_char_map);
+				set_bit(LNEXT_CHAR(tty),
+					tty->process_char_map);
+				set_bit(EOL2_CHAR(tty),
+					tty->process_char_map);
+				if (L_ECHO(tty))
+					set_bit(REPRINT_CHAR(tty),
+						tty->process_char_map);
+			}
+		}
+		if (I_IXON(tty)) {
+			set_bit(START_CHAR(tty), tty->process_char_map);
+			set_bit(STOP_CHAR(tty), tty->process_char_map);
+		}
+		if (L_ISIG(tty)) {
+			set_bit(INTR_CHAR(tty), tty->process_char_map);
+			set_bit(QUIT_CHAR(tty), tty->process_char_map);
+			set_bit(SUSP_CHAR(tty), tty->process_char_map);
+		}
+		clear_bit(__DISABLED_CHAR, tty->process_char_map);
+		tty->raw = 0;
+		tty->real_raw = 0;
+	} else {
+		tty->raw = 1;
+		if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) &&
+		    (I_IGNPAR(tty) || !I_INPCK(tty)) &&
+		    (tty->driver->flags & TTY_DRIVER_REAL_RAW))
+			tty->real_raw = 1;
+		else
+			tty->real_raw = 0;
+	}
+	n_tty_set_room(tty);
+	/* The termios change make the tty ready for I/O */
+	wake_up_interruptible(&tty->write_wait);
+	wake_up_interruptible(&tty->read_wait);
+}
+
+/**
+ *	n_tty_close		-	close the ldisc for this tty
+ *	@tty: device
+ *
+ *	Called from the terminal layer when this line discipline is
+ *	being shut down, either because of a close or becsuse of a
+ *	discipline change. The function will not be called while other
+ *	ldisc methods are in progress.
+ */
+
+static void n_tty_close(struct tty_struct *tty)
+{
+	n_tty_flush_buffer(tty);
+	if (tty->read_buf) {
+		kfree(tty->read_buf);
+		tty->read_buf = NULL;
+	}
+	if (tty->echo_buf) {
+		kfree(tty->echo_buf);
+		tty->echo_buf = NULL;
+	}
+}
+
+/**
+ *	n_tty_open		-	open an ldisc
+ *	@tty: terminal to open
+ *
+ *	Called when this line discipline is being attached to the
+ *	terminal device. Can sleep. Called serialized so that no
+ *	other events will occur in parallel. No further open will occur
+ *	until a close.
+ */
+
+static int n_tty_open(struct tty_struct *tty)
+{
+	if (!tty)
+		return -EINVAL;
+
+	/* These are ugly. Currently a malloc failure here can panic */
+	if (!tty->read_buf) {
+		tty->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
+		if (!tty->read_buf)
+			return -ENOMEM;
+	}
+	if (!tty->echo_buf) {
+		tty->echo_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
+
+		if (!tty->echo_buf)
+			return -ENOMEM;
+	}
+	reset_buffer_flags(tty);
+	tty->column = 0;
+	n_tty_set_termios(tty, NULL);
+	tty->minimum_to_wake = 1;
+	tty->closing = 0;
+	return 0;
+}
+
+static inline int input_available_p(struct tty_struct *tty, int amt)
+{
+	tty_flush_to_ldisc(tty);
+	if (tty->icanon && !L_EXTPROC(tty)) {
+		if (tty->canon_data)
+			return 1;
+	} else if (tty->read_cnt >= (amt ? amt : 1))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * 	copy_from_read_buf	-	copy read data directly
+ *	@tty: terminal device
+ *	@b: user data
+ *	@nr: size of data
+ *
+ *	Helper function to speed up n_tty_read.  It is only called when
+ *	ICANON is off; it copies characters straight from the tty queue to
+ *	user space directly.  It can be profitably called twice; once to
+ *	drain the space from the tail pointer to the (physical) end of the
+ *	buffer, and once to drain the space from the (physical) beginning of
+ *	the buffer to head pointer.
+ *
+ *	Called under the tty->atomic_read_lock sem
+ *
+ */
+
+static int copy_from_read_buf(struct tty_struct *tty,
+				      unsigned char __user **b,
+				      size_t *nr)
+
+{
+	int retval;
+	size_t n;
+	unsigned long flags;
+
+	retval = 0;
+	spin_lock_irqsave(&tty->read_lock, flags);
+	n = min(tty->read_cnt, N_TTY_BUF_SIZE - tty->read_tail);
+	n = min(*nr, n);
+	spin_unlock_irqrestore(&tty->read_lock, flags);
+	if (n) {
+		retval = copy_to_user(*b, &tty->read_buf[tty->read_tail], n);
+		n -= retval;
+		tty_audit_add_data(tty, &tty->read_buf[tty->read_tail], n);
+		spin_lock_irqsave(&tty->read_lock, flags);
+		tty->read_tail = (tty->read_tail + n) & (N_TTY_BUF_SIZE-1);
+		tty->read_cnt -= n;
+		/* Turn single EOF into zero-length read */
+		if (L_EXTPROC(tty) && tty->icanon && n == 1) {
+			if (!tty->read_cnt && (*b)[n-1] == EOF_CHAR(tty))
+				n--;
+		}
+		spin_unlock_irqrestore(&tty->read_lock, flags);
+		*b += n;
+		*nr -= n;
+	}
+	return retval;
+}
+
+extern ssize_t redirected_tty_write(struct file *, const char __user *,
+							size_t, loff_t *);
+
+/**
+ *	job_control		-	check job control
+ *	@tty: tty
+ *	@file: file handle
+ *
+ *	Perform job control management checks on this file/tty descriptor
+ *	and if appropriate send any needed signals and return a negative
+ *	error code if action should be taken.
+ *
+ *	FIXME:
+ *	Locking: None - redirected write test is safe, testing
+ *	current->signal should possibly lock current->sighand
+ *	pgrp locking ?
+ */
+
+static int job_control(struct tty_struct *tty, struct file *file)
+{
+	/* Job control check -- must be done at start and after
+	   every sleep (POSIX.1 7.1.1.4). */
+	/* NOTE: not yet done after every sleep pending a thorough
+	   check of the logic of this change. -- jlc */
+	/* don't stop on /dev/console */
+	if (file->f_op->write != redirected_tty_write &&
+	    current->signal->tty == tty) {
+		if (!tty->pgrp)
+			printk(KERN_ERR "n_tty_read: no tty->pgrp!\n");
+		else if (task_pgrp(current) != tty->pgrp) {
+			if (is_ignored(SIGTTIN) ||
+			    is_current_pgrp_orphaned())
+				return -EIO;
+			kill_pgrp(task_pgrp(current), SIGTTIN, 1);
+			set_thread_flag(TIF_SIGPENDING);
+			return -ERESTARTSYS;
+		}
+	}
+	return 0;
+}
+
+
+/**
+ *	n_tty_read		-	read function for tty
+ *	@tty: tty device
+ *	@file: file object
+ *	@buf: userspace buffer pointer
+ *	@nr: size of I/O
+ *
+ *	Perform reads for the line discipline. We are guaranteed that the
+ *	line discipline will not be closed under us but we may get multiple
+ *	parallel readers and must handle this ourselves. We may also get
+ *	a hangup. Always called in user context, may sleep.
+ *
+ *	This code must be sure never to sleep through a hangup.
+ */
+
+static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
+			 unsigned char __user *buf, size_t nr)
+{
+	unsigned char __user *b = buf;
+	DECLARE_WAITQUEUE(wait, current);
+	int c;
+	int minimum, time;
+	ssize_t retval = 0;
+	ssize_t size;
+	long timeout;
+	unsigned long flags;
+	int packet;
+
+do_it_again:
+
+	BUG_ON(!tty->read_buf);
+
+	c = job_control(tty, file);
+	if (c < 0)
+		return c;
+
+	minimum = time = 0;
+	timeout = MAX_SCHEDULE_TIMEOUT;
+	if (!tty->icanon) {
+		time = (HZ / 10) * TIME_CHAR(tty);
+		minimum = MIN_CHAR(tty);
+		if (minimum) {
+			if (time)
+				tty->minimum_to_wake = 1;
+			else if (!waitqueue_active(&tty->read_wait) ||
+				 (tty->minimum_to_wake > minimum))
+				tty->minimum_to_wake = minimum;
+		} else {
+			timeout = 0;
+			if (time) {
+				timeout = time;
+				time = 0;
+			}
+			tty->minimum_to_wake = minimum = 1;
+		}
+	}
+
+	/*
+	 *	Internal serialization of reads.
+	 */
+	if (file->f_flags & O_NONBLOCK) {
+		if (!mutex_trylock(&tty->atomic_read_lock))
+			return -EAGAIN;
+	} else {
+		if (mutex_lock_interruptible(&tty->atomic_read_lock))
+			return -ERESTARTSYS;
+	}
+	packet = tty->packet;
+
+	add_wait_queue(&tty->read_wait, &wait);
+	while (nr) {
+		/* First test for status change. */
+		if (packet && tty->link->ctrl_status) {
+			unsigned char cs;
+			if (b != buf)
+				break;
+			spin_lock_irqsave(&tty->link->ctrl_lock, flags);
+			cs = tty->link->ctrl_status;
+			tty->link->ctrl_status = 0;
+			spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
+			if (tty_put_user(tty, cs, b++)) {
+				retval = -EFAULT;
+				b--;
+				break;
+			}
+			nr--;
+			break;
+		}
+		/* This statement must be first before checking for input
+		   so that any interrupt will set the state back to
+		   TASK_RUNNING. */
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		if (((minimum - (b - buf)) < tty->minimum_to_wake) &&
+		    ((minimum - (b - buf)) >= 1))
+			tty->minimum_to_wake = (minimum - (b - buf));
+
+		if (!input_available_p(tty, 0)) {
+			if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
+				retval = -EIO;
+				break;
+			}
+			if (tty_hung_up_p(file))
+				break;
+			if (!timeout)
+				break;
+			if (file->f_flags & O_NONBLOCK) {
+				retval = -EAGAIN;
+				break;
+			}
+			if (signal_pending(current)) {
+				retval = -ERESTARTSYS;
+				break;
+			}
+			/* FIXME: does n_tty_set_room need locking ? */
+			n_tty_set_room(tty);
+			timeout = schedule_timeout(timeout);
+			continue;
+		}
+		__set_current_state(TASK_RUNNING);
+
+		/* Deal with packet mode. */
+		if (packet && b == buf) {
+			if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
+				retval = -EFAULT;
+				b--;
+				break;
+			}
+			nr--;
+		}
+
+		if (tty->icanon && !L_EXTPROC(tty)) {
+			/* N.B. avoid overrun if nr == 0 */
+			while (nr && tty->read_cnt) {
+				int eol;
+
+				eol = test_and_clear_bit(tty->read_tail,
+						tty->read_flags);
+				c = tty->read_buf[tty->read_tail];
+				spin_lock_irqsave(&tty->read_lock, flags);
+				tty->read_tail = ((tty->read_tail+1) &
+						  (N_TTY_BUF_SIZE-1));
+				tty->read_cnt--;
+				if (eol) {
+					/* this test should be redundant:
+					 * we shouldn't be reading data if
+					 * canon_data is 0
+					 */
+					if (--tty->canon_data < 0)
+						tty->canon_data = 0;
+				}
+				spin_unlock_irqrestore(&tty->read_lock, flags);
+
+				if (!eol || (c != __DISABLED_CHAR)) {
+					if (tty_put_user(tty, c, b++)) {
+						retval = -EFAULT;
+						b--;
+						break;
+					}
+					nr--;
+				}
+				if (eol) {
+					tty_audit_push(tty);
+					break;
+				}
+			}
+			if (retval)
+				break;
+		} else {
+			int uncopied;
+			/* The copy function takes the read lock and handles
+			   locking internally for this case */
+			uncopied = copy_from_read_buf(tty, &b, &nr);
+			uncopied += copy_from_read_buf(tty, &b, &nr);
+			if (uncopied) {
+				retval = -EFAULT;
+				break;
+			}
+		}
+
+		/* If there is enough space in the read buffer now, let the
+		 * low-level driver know. We use n_tty_chars_in_buffer() to
+		 * check the buffer, as it now knows about canonical mode.
+		 * Otherwise, if the driver is throttled and the line is
+		 * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
+		 * we won't get any more characters.
+		 */
+		if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) {
+			n_tty_set_room(tty);
+			check_unthrottle(tty);
+		}
+
+		if (b - buf >= minimum)
+			break;
+		if (time)
+			timeout = time;
+	}
+	mutex_unlock(&tty->atomic_read_lock);
+	remove_wait_queue(&tty->read_wait, &wait);
+
+	if (!waitqueue_active(&tty->read_wait))
+		tty->minimum_to_wake = minimum;
+
+	__set_current_state(TASK_RUNNING);
+	size = b - buf;
+	if (size) {
+		retval = size;
+		if (nr)
+			clear_bit(TTY_PUSH, &tty->flags);
+	} else if (test_and_clear_bit(TTY_PUSH, &tty->flags))
+		 goto do_it_again;
+
+	n_tty_set_room(tty);
+	return retval;
+}
+
+/**
+ *	n_tty_write		-	write function for tty
+ *	@tty: tty device
+ *	@file: file object
+ *	@buf: userspace buffer pointer
+ *	@nr: size of I/O
+ *
+ *	Write function of the terminal device.  This is serialized with
+ *	respect to other write callers but not to termios changes, reads
+ *	and other such events.  Since the receive code will echo characters,
+ *	thus calling driver write methods, the output_lock is used in
+ *	the output processing functions called here as well as in the
+ *	echo processing function to protect the column state and space
+ *	left in the buffer.
+ *
+ *	This code must be sure never to sleep through a hangup.
+ *
+ *	Locking: output_lock to protect column state and space left
+ *		 (note that the process_output*() functions take this
+ *		  lock themselves)
+ */
+
+static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
+			   const unsigned char *buf, size_t nr)
+{
+	const unsigned char *b = buf;
+	DECLARE_WAITQUEUE(wait, current);
+	int c;
+	ssize_t retval = 0;
+
+	/* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
+	if (L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) {
+		retval = tty_check_change(tty);
+		if (retval)
+			return retval;
+	}
+
+	/* Write out any echoed characters that are still pending */
+	process_echoes(tty);
+
+	add_wait_queue(&tty->write_wait, &wait);
+	while (1) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+		if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) {
+			retval = -EIO;
+			break;
+		}
+		if (O_OPOST(tty) && !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
+			while (nr > 0) {
+				ssize_t num = process_output_block(tty, b, nr);
+				if (num < 0) {
+					if (num == -EAGAIN)
+						break;
+					retval = num;
+					goto break_out;
+				}
+				b += num;
+				nr -= num;
+				if (nr == 0)
+					break;
+				c = *b;
+				if (process_output(c, tty) < 0)
+					break;
+				b++; nr--;
+			}
+			if (tty->ops->flush_chars)
+				tty->ops->flush_chars(tty);
+		} else {
+			while (nr > 0) {
+				c = tty->ops->write(tty, b, nr);
+				if (c < 0) {
+					retval = c;
+					goto break_out;
+				}
+				if (!c)
+					break;
+				b += c;
+				nr -= c;
+			}
+		}
+		if (!nr)
+			break;
+		if (file->f_flags & O_NONBLOCK) {
+			retval = -EAGAIN;
+			break;
+		}
+		schedule();
+	}
+break_out:
+	__set_current_state(TASK_RUNNING);
+	remove_wait_queue(&tty->write_wait, &wait);
+	if (b - buf != nr && tty->fasync)
+		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	return (b - buf) ? b - buf : retval;
+}
+
+/**
+ *	n_tty_poll		-	poll method for N_TTY
+ *	@tty: terminal device
+ *	@file: file accessing it
+ *	@wait: poll table
+ *
+ *	Called when the line discipline is asked to poll() for data or
+ *	for special events. This code is not serialized with respect to
+ *	other events save open/close.
+ *
+ *	This code must be sure never to sleep through a hangup.
+ *	Called without the kernel lock held - fine
+ */
+
+static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
+							poll_table *wait)
+{
+	unsigned int mask = 0;
+
+	poll_wait(file, &tty->read_wait, wait);
+	poll_wait(file, &tty->write_wait, wait);
+	if (input_available_p(tty, TIME_CHAR(tty) ? 0 : MIN_CHAR(tty)))
+		mask |= POLLIN | POLLRDNORM;
+	if (tty->packet && tty->link->ctrl_status)
+		mask |= POLLPRI | POLLIN | POLLRDNORM;
+	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+		mask |= POLLHUP;
+	if (tty_hung_up_p(file))
+		mask |= POLLHUP;
+	if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) {
+		if (MIN_CHAR(tty) && !TIME_CHAR(tty))
+			tty->minimum_to_wake = MIN_CHAR(tty);
+		else
+			tty->minimum_to_wake = 1;
+	}
+	if (tty->ops->write && !tty_is_writelocked(tty) &&
+			tty_chars_in_buffer(tty) < WAKEUP_CHARS &&
+			tty_write_room(tty) > 0)
+		mask |= POLLOUT | POLLWRNORM;
+	return mask;
+}
+
+static unsigned long inq_canon(struct tty_struct *tty)
+{
+	int nr, head, tail;
+
+	if (!tty->canon_data)
+		return 0;
+	head = tty->canon_head;
+	tail = tty->read_tail;
+	nr = (head - tail) & (N_TTY_BUF_SIZE-1);
+	/* Skip EOF-chars.. */
+	while (head != tail) {
+		if (test_bit(tail, tty->read_flags) &&
+		    tty->read_buf[tail] == __DISABLED_CHAR)
+			nr--;
+		tail = (tail+1) & (N_TTY_BUF_SIZE-1);
+	}
+	return nr;
+}
+
+static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
+		       unsigned int cmd, unsigned long arg)
+{
+	int retval;
+
+	switch (cmd) {
+	case TIOCOUTQ:
+		return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
+	case TIOCINQ:
+		/* FIXME: Locking */
+		retval = tty->read_cnt;
+		if (L_ICANON(tty))
+			retval = inq_canon(tty);
+		return put_user(retval, (unsigned int __user *) arg);
+	default:
+		return n_tty_ioctl_helper(tty, file, cmd, arg);
+	}
+}
+
+struct tty_ldisc_ops tty_ldisc_N_TTY = {
+	.magic           = TTY_LDISC_MAGIC,
+	.name            = "n_tty",
+	.open            = n_tty_open,
+	.close           = n_tty_close,
+	.flush_buffer    = n_tty_flush_buffer,
+	.chars_in_buffer = n_tty_chars_in_buffer,
+	.read            = n_tty_read,
+	.write           = n_tty_write,
+	.ioctl           = n_tty_ioctl,
+	.set_termios     = n_tty_set_termios,
+	.poll            = n_tty_poll,
+	.receive_buf     = n_tty_receive_buf,
+	.write_wakeup    = n_tty_write_wakeup
+};
+
+/**
+ *	n_tty_inherit_ops	-	inherit N_TTY methods
+ *	@ops: struct tty_ldisc_ops where to save N_TTY methods
+ *
+ *	Used by a generic struct tty_ldisc_ops to easily inherit N_TTY
+ *	methods.
+ */
+
+void n_tty_inherit_ops(struct tty_ldisc_ops *ops)
+{
+	*ops = tty_ldisc_N_TTY;
+	ops->owner = NULL;
+	ops->refcount = ops->flags = 0;
+}
+EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
new file mode 100644
index 0000000..923a485
--- /dev/null
+++ b/drivers/tty/pty.c
@@ -0,0 +1,777 @@
+/*
+ *  linux/drivers/char/pty.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  Added support for a Unix98-style ptmx device.
+ *    -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
+ *
+ *  When reading this code see also fs/devpts. In particular note that the
+ *  driver_data field is used by the devpts side as a binding to the devpts
+ *  inode.
+ */
+
+#include <linux/module.h>
+
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/major.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/smp_lock.h>
+#include <linux/sysctl.h>
+#include <linux/device.h>
+#include <linux/uaccess.h>
+#include <linux/bitops.h>
+#include <linux/devpts_fs.h>
+#include <linux/slab.h>
+
+#include <asm/system.h>
+
+#ifdef CONFIG_UNIX98_PTYS
+static struct tty_driver *ptm_driver;
+static struct tty_driver *pts_driver;
+#endif
+
+static void pty_close(struct tty_struct *tty, struct file *filp)
+{
+	BUG_ON(!tty);
+	if (tty->driver->subtype == PTY_TYPE_MASTER)
+		WARN_ON(tty->count > 1);
+	else {
+		if (tty->count > 2)
+			return;
+	}
+	wake_up_interruptible(&tty->read_wait);
+	wake_up_interruptible(&tty->write_wait);
+	tty->packet = 0;
+	if (!tty->link)
+		return;
+	tty->link->packet = 0;
+	set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
+	wake_up_interruptible(&tty->link->read_wait);
+	wake_up_interruptible(&tty->link->write_wait);
+	if (tty->driver->subtype == PTY_TYPE_MASTER) {
+		set_bit(TTY_OTHER_CLOSED, &tty->flags);
+#ifdef CONFIG_UNIX98_PTYS
+		if (tty->driver == ptm_driver)
+			devpts_pty_kill(tty->link);
+#endif
+		tty_unlock();
+		tty_vhangup(tty->link);
+		tty_lock();
+	}
+}
+
+/*
+ * The unthrottle routine is called by the line discipline to signal
+ * that it can receive more characters.  For PTY's, the TTY_THROTTLED
+ * flag is always set, to force the line discipline to always call the
+ * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
+ * characters in the queue.  This is necessary since each time this
+ * happens, we need to wake up any sleeping processes that could be
+ * (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
+ * for the pty buffer to be drained.
+ */
+static void pty_unthrottle(struct tty_struct *tty)
+{
+	tty_wakeup(tty->link);
+	set_bit(TTY_THROTTLED, &tty->flags);
+}
+
+/**
+ *	pty_space	-	report space left for writing
+ *	@to: tty we are writing into
+ *
+ *	The tty buffers allow 64K but we sneak a peak and clip at 8K this
+ *	allows a lot of overspill room for echo and other fun messes to
+ *	be handled properly
+ */
+
+static int pty_space(struct tty_struct *to)
+{
+	int n = 8192 - to->buf.memory_used;
+	if (n < 0)
+		return 0;
+	return n;
+}
+
+/**
+ *	pty_write		-	write to a pty
+ *	@tty: the tty we write from
+ *	@buf: kernel buffer of data
+ *	@count: bytes to write
+ *
+ *	Our "hardware" write method. Data is coming from the ldisc which
+ *	may be in a non sleeping state. We simply throw this at the other
+ *	end of the link as if we were an IRQ handler receiving stuff for
+ *	the other side of the pty/tty pair.
+ */
+
+static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
+{
+	struct tty_struct *to = tty->link;
+
+	if (tty->stopped)
+		return 0;
+
+	if (c > 0) {
+		/* Stuff the data into the input queue of the other end */
+		c = tty_insert_flip_string(to, buf, c);
+		/* And shovel */
+		if (c) {
+			tty_flip_buffer_push(to);
+			tty_wakeup(tty);
+		}
+	}
+	return c;
+}
+
+/**
+ *	pty_write_room	-	write space
+ *	@tty: tty we are writing from
+ *
+ *	Report how many bytes the ldisc can send into the queue for
+ *	the other device.
+ */
+
+static int pty_write_room(struct tty_struct *tty)
+{
+	if (tty->stopped)
+		return 0;
+	return pty_space(tty->link);
+}
+
+/**
+ *	pty_chars_in_buffer	-	characters currently in our tx queue
+ *	@tty: our tty
+ *
+ *	Report how much we have in the transmit queue. As everything is
+ *	instantly at the other end this is easy to implement.
+ */
+
+static int pty_chars_in_buffer(struct tty_struct *tty)
+{
+	return 0;
+}
+
+/* Set the lock flag on a pty */
+static int pty_set_lock(struct tty_struct *tty, int __user *arg)
+{
+	int val;
+	if (get_user(val, arg))
+		return -EFAULT;
+	if (val)
+		set_bit(TTY_PTY_LOCK, &tty->flags);
+	else
+		clear_bit(TTY_PTY_LOCK, &tty->flags);
+	return 0;
+}
+
+/* Send a signal to the slave */
+static int pty_signal(struct tty_struct *tty, int sig)
+{
+	unsigned long flags;
+	struct pid *pgrp;
+
+	if (tty->link) {
+		spin_lock_irqsave(&tty->link->ctrl_lock, flags);
+		pgrp = get_pid(tty->link->pgrp);
+		spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
+
+		kill_pgrp(pgrp, sig, 1);
+		put_pid(pgrp);
+	}
+	return 0;
+}
+
+static void pty_flush_buffer(struct tty_struct *tty)
+{
+	struct tty_struct *to = tty->link;
+	unsigned long flags;
+
+	if (!to)
+		return;
+	/* tty_buffer_flush(to); FIXME */
+	if (to->packet) {
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
+		tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
+		wake_up_interruptible(&to->read_wait);
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	}
+}
+
+static int pty_open(struct tty_struct *tty, struct file *filp)
+{
+	int	retval = -ENODEV;
+
+	if (!tty || !tty->link)
+		goto out;
+
+	retval = -EIO;
+	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+		goto out;
+	if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
+		goto out;
+	if (tty->link->count != 1)
+		goto out;
+
+	clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
+	set_bit(TTY_THROTTLED, &tty->flags);
+	retval = 0;
+out:
+	return retval;
+}
+
+static void pty_set_termios(struct tty_struct *tty,
+					struct ktermios *old_termios)
+{
+	tty->termios->c_cflag &= ~(CSIZE | PARENB);
+	tty->termios->c_cflag |= (CS8 | CREAD);
+}
+
+/**
+ *	pty_do_resize		-	resize event
+ *	@tty: tty being resized
+ *	@ws: window size being set.
+ *
+ *	Update the termios variables and send the necessary signals to
+ *	peform a terminal resize correctly
+ */
+
+int pty_resize(struct tty_struct *tty,  struct winsize *ws)
+{
+	struct pid *pgrp, *rpgrp;
+	unsigned long flags;
+	struct tty_struct *pty = tty->link;
+
+	/* For a PTY we need to lock the tty side */
+	mutex_lock(&tty->termios_mutex);
+	if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
+		goto done;
+
+	/* Get the PID values and reference them so we can
+	   avoid holding the tty ctrl lock while sending signals.
+	   We need to lock these individually however. */
+
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	pgrp = get_pid(tty->pgrp);
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+	spin_lock_irqsave(&pty->ctrl_lock, flags);
+	rpgrp = get_pid(pty->pgrp);
+	spin_unlock_irqrestore(&pty->ctrl_lock, flags);
+
+	if (pgrp)
+		kill_pgrp(pgrp, SIGWINCH, 1);
+	if (rpgrp != pgrp && rpgrp)
+		kill_pgrp(rpgrp, SIGWINCH, 1);
+
+	put_pid(pgrp);
+	put_pid(rpgrp);
+
+	tty->winsize = *ws;
+	pty->winsize = *ws;	/* Never used so will go away soon */
+done:
+	mutex_unlock(&tty->termios_mutex);
+	return 0;
+}
+
+/* Traditional BSD devices */
+#ifdef CONFIG_LEGACY_PTYS
+
+static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct tty_struct *o_tty;
+	int idx = tty->index;
+	int retval;
+
+	o_tty = alloc_tty_struct();
+	if (!o_tty)
+		return -ENOMEM;
+	if (!try_module_get(driver->other->owner)) {
+		/* This cannot in fact currently happen */
+		free_tty_struct(o_tty);
+		return -ENOMEM;
+	}
+	initialize_tty_struct(o_tty, driver->other, idx);
+
+	/* We always use new tty termios data so we can do this
+	   the easy way .. */
+	retval = tty_init_termios(tty);
+	if (retval)
+		goto free_mem_out;
+
+	retval = tty_init_termios(o_tty);
+	if (retval) {
+		tty_free_termios(tty);
+		goto free_mem_out;
+	}
+
+	/*
+	 * Everything allocated ... set up the o_tty structure.
+	 */
+	driver->other->ttys[idx] = o_tty;
+	tty_driver_kref_get(driver->other);
+	if (driver->subtype == PTY_TYPE_MASTER)
+		o_tty->count++;
+	/* Establish the links in both directions */
+	tty->link   = o_tty;
+	o_tty->link = tty;
+
+	tty_driver_kref_get(driver);
+	tty->count++;
+	driver->ttys[idx] = tty;
+	return 0;
+free_mem_out:
+	module_put(o_tty->driver->owner);
+	free_tty_struct(o_tty);
+	return -ENOMEM;
+}
+
+static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file,
+			 unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
+		return pty_set_lock(tty, (int __user *) arg);
+	case TIOCSIG:    /* Send signal to other side of pty */
+		return pty_signal(tty, (int) arg);
+	}
+	return -ENOIOCTLCMD;
+}
+
+static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
+module_param(legacy_count, int, 0);
+
+/*
+ * The master side of a pty can do TIOCSPTLCK and thus
+ * has pty_bsd_ioctl.
+ */
+static const struct tty_operations master_pty_ops_bsd = {
+	.install = pty_install,
+	.open = pty_open,
+	.close = pty_close,
+	.write = pty_write,
+	.write_room = pty_write_room,
+	.flush_buffer = pty_flush_buffer,
+	.chars_in_buffer = pty_chars_in_buffer,
+	.unthrottle = pty_unthrottle,
+	.set_termios = pty_set_termios,
+	.ioctl = pty_bsd_ioctl,
+	.resize = pty_resize
+};
+
+static const struct tty_operations slave_pty_ops_bsd = {
+	.install = pty_install,
+	.open = pty_open,
+	.close = pty_close,
+	.write = pty_write,
+	.write_room = pty_write_room,
+	.flush_buffer = pty_flush_buffer,
+	.chars_in_buffer = pty_chars_in_buffer,
+	.unthrottle = pty_unthrottle,
+	.set_termios = pty_set_termios,
+	.resize = pty_resize
+};
+
+static void __init legacy_pty_init(void)
+{
+	struct tty_driver *pty_driver, *pty_slave_driver;
+
+	if (legacy_count <= 0)
+		return;
+
+	pty_driver = alloc_tty_driver(legacy_count);
+	if (!pty_driver)
+		panic("Couldn't allocate pty driver");
+
+	pty_slave_driver = alloc_tty_driver(legacy_count);
+	if (!pty_slave_driver)
+		panic("Couldn't allocate pty slave driver");
+
+	pty_driver->owner = THIS_MODULE;
+	pty_driver->driver_name = "pty_master";
+	pty_driver->name = "pty";
+	pty_driver->major = PTY_MASTER_MAJOR;
+	pty_driver->minor_start = 0;
+	pty_driver->type = TTY_DRIVER_TYPE_PTY;
+	pty_driver->subtype = PTY_TYPE_MASTER;
+	pty_driver->init_termios = tty_std_termios;
+	pty_driver->init_termios.c_iflag = 0;
+	pty_driver->init_termios.c_oflag = 0;
+	pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+	pty_driver->init_termios.c_lflag = 0;
+	pty_driver->init_termios.c_ispeed = 38400;
+	pty_driver->init_termios.c_ospeed = 38400;
+	pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
+	pty_driver->other = pty_slave_driver;
+	tty_set_operations(pty_driver, &master_pty_ops_bsd);
+
+	pty_slave_driver->owner = THIS_MODULE;
+	pty_slave_driver->driver_name = "pty_slave";
+	pty_slave_driver->name = "ttyp";
+	pty_slave_driver->major = PTY_SLAVE_MAJOR;
+	pty_slave_driver->minor_start = 0;
+	pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
+	pty_slave_driver->subtype = PTY_TYPE_SLAVE;
+	pty_slave_driver->init_termios = tty_std_termios;
+	pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+	pty_slave_driver->init_termios.c_ispeed = 38400;
+	pty_slave_driver->init_termios.c_ospeed = 38400;
+	pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
+					TTY_DRIVER_REAL_RAW;
+	pty_slave_driver->other = pty_driver;
+	tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
+
+	if (tty_register_driver(pty_driver))
+		panic("Couldn't register pty driver");
+	if (tty_register_driver(pty_slave_driver))
+		panic("Couldn't register pty slave driver");
+}
+#else
+static inline void legacy_pty_init(void) { }
+#endif
+
+/* Unix98 devices */
+#ifdef CONFIG_UNIX98_PTYS
+/*
+ * sysctl support for setting limits on the number of Unix98 ptys allocated.
+ * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
+ */
+int pty_limit = NR_UNIX98_PTY_DEFAULT;
+static int pty_limit_min;
+static int pty_limit_max = NR_UNIX98_PTY_MAX;
+static int pty_count;
+
+static struct cdev ptmx_cdev;
+
+static struct ctl_table pty_table[] = {
+	{
+		.procname	= "max",
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.data		= &pty_limit,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &pty_limit_min,
+		.extra2		= &pty_limit_max,
+	}, {
+		.procname	= "nr",
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.data		= &pty_count,
+		.proc_handler	= proc_dointvec,
+	}, 
+	{}
+};
+
+static struct ctl_table pty_kern_table[] = {
+	{
+		.procname	= "pty",
+		.mode		= 0555,
+		.child		= pty_table,
+	},
+	{}
+};
+
+static struct ctl_table pty_root_table[] = {
+	{
+		.procname	= "kernel",
+		.mode		= 0555,
+		.child		= pty_kern_table,
+	},
+	{}
+};
+
+
+static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
+			    unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
+		return pty_set_lock(tty, (int __user *)arg);
+	case TIOCGPTN: /* Get PT Number */
+		return put_user(tty->index, (unsigned int __user *)arg);
+	case TIOCSIG:    /* Send signal to other side of pty */
+		return pty_signal(tty, (int) arg);
+	}
+
+	return -ENOIOCTLCMD;
+}
+
+/**
+ *	ptm_unix98_lookup	-	find a pty master
+ *	@driver: ptm driver
+ *	@idx: tty index
+ *
+ *	Look up a pty master device. Called under the tty_mutex for now.
+ *	This provides our locking.
+ */
+
+static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
+		struct inode *ptm_inode, int idx)
+{
+	struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
+	if (tty)
+		tty = tty->link;
+	return tty;
+}
+
+/**
+ *	pts_unix98_lookup	-	find a pty slave
+ *	@driver: pts driver
+ *	@idx: tty index
+ *
+ *	Look up a pty master device. Called under the tty_mutex for now.
+ *	This provides our locking.
+ */
+
+static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
+		struct inode *pts_inode, int idx)
+{
+	struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
+	/* Master must be open before slave */
+	if (!tty)
+		return ERR_PTR(-EIO);
+	return tty;
+}
+
+static void pty_unix98_shutdown(struct tty_struct *tty)
+{
+	/* We have our own method as we don't use the tty index */
+	kfree(tty->termios);
+}
+
+/* We have no need to install and remove our tty objects as devpts does all
+   the work for us */
+
+static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct tty_struct *o_tty;
+	int idx = tty->index;
+
+	o_tty = alloc_tty_struct();
+	if (!o_tty)
+		return -ENOMEM;
+	if (!try_module_get(driver->other->owner)) {
+		/* This cannot in fact currently happen */
+		free_tty_struct(o_tty);
+		return -ENOMEM;
+	}
+	initialize_tty_struct(o_tty, driver->other, idx);
+
+	tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
+	if (tty->termios == NULL)
+		goto free_mem_out;
+	*tty->termios = driver->init_termios;
+	tty->termios_locked = tty->termios + 1;
+
+	o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
+	if (o_tty->termios == NULL)
+		goto free_mem_out;
+	*o_tty->termios = driver->other->init_termios;
+	o_tty->termios_locked = o_tty->termios + 1;
+
+	tty_driver_kref_get(driver->other);
+	if (driver->subtype == PTY_TYPE_MASTER)
+		o_tty->count++;
+	/* Establish the links in both directions */
+	tty->link   = o_tty;
+	o_tty->link = tty;
+	/*
+	 * All structures have been allocated, so now we install them.
+	 * Failures after this point use release_tty to clean up, so
+	 * there's no need to null out the local pointers.
+	 */
+	tty_driver_kref_get(driver);
+	tty->count++;
+	pty_count++;
+	return 0;
+free_mem_out:
+	kfree(o_tty->termios);
+	module_put(o_tty->driver->owner);
+	free_tty_struct(o_tty);
+	kfree(tty->termios);
+	return -ENOMEM;
+}
+
+static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
+{
+	pty_count--;
+}
+
+static const struct tty_operations ptm_unix98_ops = {
+	.lookup = ptm_unix98_lookup,
+	.install = pty_unix98_install,
+	.remove = pty_unix98_remove,
+	.open = pty_open,
+	.close = pty_close,
+	.write = pty_write,
+	.write_room = pty_write_room,
+	.flush_buffer = pty_flush_buffer,
+	.chars_in_buffer = pty_chars_in_buffer,
+	.unthrottle = pty_unthrottle,
+	.set_termios = pty_set_termios,
+	.ioctl = pty_unix98_ioctl,
+	.shutdown = pty_unix98_shutdown,
+	.resize = pty_resize
+};
+
+static const struct tty_operations pty_unix98_ops = {
+	.lookup = pts_unix98_lookup,
+	.install = pty_unix98_install,
+	.remove = pty_unix98_remove,
+	.open = pty_open,
+	.close = pty_close,
+	.write = pty_write,
+	.write_room = pty_write_room,
+	.flush_buffer = pty_flush_buffer,
+	.chars_in_buffer = pty_chars_in_buffer,
+	.unthrottle = pty_unthrottle,
+	.set_termios = pty_set_termios,
+	.shutdown = pty_unix98_shutdown
+};
+
+/**
+ *	ptmx_open		-	open a unix 98 pty master
+ *	@inode: inode of device file
+ *	@filp: file pointer to tty
+ *
+ *	Allocate a unix98 pty master device from the ptmx driver.
+ *
+ *	Locking: tty_mutex protects the init_dev work. tty->count should
+ * 		protect the rest.
+ *		allocated_ptys_lock handles the list of free pty numbers
+ */
+
+static int ptmx_open(struct inode *inode, struct file *filp)
+{
+	struct tty_struct *tty;
+	int retval;
+	int index;
+
+	nonseekable_open(inode, filp);
+
+	/* find a device that is not in use. */
+	tty_lock();
+	index = devpts_new_index(inode);
+	tty_unlock();
+	if (index < 0)
+		return index;
+
+	mutex_lock(&tty_mutex);
+	tty_lock();
+	tty = tty_init_dev(ptm_driver, index, 1);
+	mutex_unlock(&tty_mutex);
+
+	if (IS_ERR(tty)) {
+		retval = PTR_ERR(tty);
+		goto out;
+	}
+
+	set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
+
+	retval = tty_add_file(tty, filp);
+	if (retval)
+		goto out;
+
+	retval = devpts_pty_new(inode, tty->link);
+	if (retval)
+		goto out1;
+
+	retval = ptm_driver->ops->open(tty, filp);
+	if (retval)
+		goto out2;
+out1:
+	tty_unlock();
+	return retval;
+out2:
+	tty_unlock();
+	tty_release(inode, filp);
+	return retval;
+out:
+	devpts_kill_index(inode, index);
+	tty_unlock();
+	return retval;
+}
+
+static struct file_operations ptmx_fops;
+
+static void __init unix98_pty_init(void)
+{
+	ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
+	if (!ptm_driver)
+		panic("Couldn't allocate Unix98 ptm driver");
+	pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
+	if (!pts_driver)
+		panic("Couldn't allocate Unix98 pts driver");
+
+	ptm_driver->owner = THIS_MODULE;
+	ptm_driver->driver_name = "pty_master";
+	ptm_driver->name = "ptm";
+	ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
+	ptm_driver->minor_start = 0;
+	ptm_driver->type = TTY_DRIVER_TYPE_PTY;
+	ptm_driver->subtype = PTY_TYPE_MASTER;
+	ptm_driver->init_termios = tty_std_termios;
+	ptm_driver->init_termios.c_iflag = 0;
+	ptm_driver->init_termios.c_oflag = 0;
+	ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+	ptm_driver->init_termios.c_lflag = 0;
+	ptm_driver->init_termios.c_ispeed = 38400;
+	ptm_driver->init_termios.c_ospeed = 38400;
+	ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
+		TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
+	ptm_driver->other = pts_driver;
+	tty_set_operations(ptm_driver, &ptm_unix98_ops);
+
+	pts_driver->owner = THIS_MODULE;
+	pts_driver->driver_name = "pty_slave";
+	pts_driver->name = "pts";
+	pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
+	pts_driver->minor_start = 0;
+	pts_driver->type = TTY_DRIVER_TYPE_PTY;
+	pts_driver->subtype = PTY_TYPE_SLAVE;
+	pts_driver->init_termios = tty_std_termios;
+	pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+	pts_driver->init_termios.c_ispeed = 38400;
+	pts_driver->init_termios.c_ospeed = 38400;
+	pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
+		TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
+	pts_driver->other = ptm_driver;
+	tty_set_operations(pts_driver, &pty_unix98_ops);
+
+	if (tty_register_driver(ptm_driver))
+		panic("Couldn't register Unix98 ptm driver");
+	if (tty_register_driver(pts_driver))
+		panic("Couldn't register Unix98 pts driver");
+
+	register_sysctl_table(pty_root_table);
+
+	/* Now create the /dev/ptmx special device */
+	tty_default_fops(&ptmx_fops);
+	ptmx_fops.open = ptmx_open;
+
+	cdev_init(&ptmx_cdev, &ptmx_fops);
+	if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
+	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
+		panic("Couldn't register /dev/ptmx driver\n");
+	device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
+}
+
+#else
+static inline void unix98_pty_init(void) { }
+#endif
+
+static int __init pty_init(void)
+{
+	legacy_pty_init();
+	unix98_pty_init();
+	return 0;
+}
+module_init(pty_init);
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
new file mode 100644
index 0000000..c556ed9
--- /dev/null
+++ b/drivers/tty/sysrq.c
@@ -0,0 +1,890 @@
+/*
+ *	Linux Magic System Request Key Hacks
+ *
+ *	(c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ *	based on ideas by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>
+ *
+ *	(c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
+ *	overhauled to use key registration
+ *	based upon discusions in irc://irc.openprojects.net/#kernelnewbies
+ *
+ *	Copyright (c) 2010 Dmitry Torokhov
+ *	Input handler conversion
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/kdev_t.h>
+#include <linux/major.h>
+#include <linux/reboot.h>
+#include <linux/sysrq.h>
+#include <linux/kbd_kern.h>
+#include <linux/proc_fs.h>
+#include <linux/nmi.h>
+#include <linux/quotaops.h>
+#include <linux/perf_event.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/suspend.h>
+#include <linux/writeback.h>
+#include <linux/buffer_head.h>		/* for fsync_bdev() */
+#include <linux/swap.h>
+#include <linux/spinlock.h>
+#include <linux/vt_kern.h>
+#include <linux/workqueue.h>
+#include <linux/hrtimer.h>
+#include <linux/oom.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+
+#include <asm/ptrace.h>
+#include <asm/irq_regs.h>
+
+/* Whether we react on sysrq keys or just ignore them */
+static int __read_mostly sysrq_enabled = 1;
+static bool __read_mostly sysrq_always_enabled;
+
+static bool sysrq_on(void)
+{
+	return sysrq_enabled || sysrq_always_enabled;
+}
+
+/*
+ * A value of 1 means 'all', other nonzero values are an op mask:
+ */
+static bool sysrq_on_mask(int mask)
+{
+	return sysrq_always_enabled ||
+	       sysrq_enabled == 1 ||
+	       (sysrq_enabled & mask);
+}
+
+static int __init sysrq_always_enabled_setup(char *str)
+{
+	sysrq_always_enabled = true;
+	pr_info("sysrq always enabled.\n");
+
+	return 1;
+}
+
+__setup("sysrq_always_enabled", sysrq_always_enabled_setup);
+
+
+static void sysrq_handle_loglevel(int key)
+{
+	int i;
+
+	i = key - '0';
+	console_loglevel = 7;
+	printk("Loglevel set to %d\n", i);
+	console_loglevel = i;
+}
+static struct sysrq_key_op sysrq_loglevel_op = {
+	.handler	= sysrq_handle_loglevel,
+	.help_msg	= "loglevel(0-9)",
+	.action_msg	= "Changing Loglevel",
+	.enable_mask	= SYSRQ_ENABLE_LOG,
+};
+
+#ifdef CONFIG_VT
+static void sysrq_handle_SAK(int key)
+{
+	struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
+	schedule_work(SAK_work);
+}
+static struct sysrq_key_op sysrq_SAK_op = {
+	.handler	= sysrq_handle_SAK,
+	.help_msg	= "saK",
+	.action_msg	= "SAK",
+	.enable_mask	= SYSRQ_ENABLE_KEYBOARD,
+};
+#else
+#define sysrq_SAK_op (*(struct sysrq_key_op *)NULL)
+#endif
+
+#ifdef CONFIG_VT
+static void sysrq_handle_unraw(int key)
+{
+	struct kbd_struct *kbd = &kbd_table[fg_console];
+
+	if (kbd)
+		kbd->kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
+}
+static struct sysrq_key_op sysrq_unraw_op = {
+	.handler	= sysrq_handle_unraw,
+	.help_msg	= "unRaw",
+	.action_msg	= "Keyboard mode set to system default",
+	.enable_mask	= SYSRQ_ENABLE_KEYBOARD,
+};
+#else
+#define sysrq_unraw_op (*(struct sysrq_key_op *)NULL)
+#endif /* CONFIG_VT */
+
+static void sysrq_handle_crash(int key)
+{
+	char *killer = NULL;
+
+	panic_on_oops = 1;	/* force panic */
+	wmb();
+	*killer = 1;
+}
+static struct sysrq_key_op sysrq_crash_op = {
+	.handler	= sysrq_handle_crash,
+	.help_msg	= "Crash",
+	.action_msg	= "Trigger a crash",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+
+static void sysrq_handle_reboot(int key)
+{
+	lockdep_off();
+	local_irq_enable();
+	emergency_restart();
+}
+static struct sysrq_key_op sysrq_reboot_op = {
+	.handler	= sysrq_handle_reboot,
+	.help_msg	= "reBoot",
+	.action_msg	= "Resetting",
+	.enable_mask	= SYSRQ_ENABLE_BOOT,
+};
+
+static void sysrq_handle_sync(int key)
+{
+	emergency_sync();
+}
+static struct sysrq_key_op sysrq_sync_op = {
+	.handler	= sysrq_handle_sync,
+	.help_msg	= "Sync",
+	.action_msg	= "Emergency Sync",
+	.enable_mask	= SYSRQ_ENABLE_SYNC,
+};
+
+static void sysrq_handle_show_timers(int key)
+{
+	sysrq_timer_list_show();
+}
+
+static struct sysrq_key_op sysrq_show_timers_op = {
+	.handler	= sysrq_handle_show_timers,
+	.help_msg	= "show-all-timers(Q)",
+	.action_msg	= "Show clockevent devices & pending hrtimers (no others)",
+};
+
+static void sysrq_handle_mountro(int key)
+{
+	emergency_remount();
+}
+static struct sysrq_key_op sysrq_mountro_op = {
+	.handler	= sysrq_handle_mountro,
+	.help_msg	= "Unmount",
+	.action_msg	= "Emergency Remount R/O",
+	.enable_mask	= SYSRQ_ENABLE_REMOUNT,
+};
+
+#ifdef CONFIG_LOCKDEP
+static void sysrq_handle_showlocks(int key)
+{
+	debug_show_all_locks();
+}
+
+static struct sysrq_key_op sysrq_showlocks_op = {
+	.handler	= sysrq_handle_showlocks,
+	.help_msg	= "show-all-locks(D)",
+	.action_msg	= "Show Locks Held",
+};
+#else
+#define sysrq_showlocks_op (*(struct sysrq_key_op *)NULL)
+#endif
+
+#ifdef CONFIG_SMP
+static DEFINE_SPINLOCK(show_lock);
+
+static void showacpu(void *dummy)
+{
+	unsigned long flags;
+
+	/* Idle CPUs have no interesting backtrace. */
+	if (idle_cpu(smp_processor_id()))
+		return;
+
+	spin_lock_irqsave(&show_lock, flags);
+	printk(KERN_INFO "CPU%d:\n", smp_processor_id());
+	show_stack(NULL, NULL);
+	spin_unlock_irqrestore(&show_lock, flags);
+}
+
+static void sysrq_showregs_othercpus(struct work_struct *dummy)
+{
+	smp_call_function(showacpu, NULL, 0);
+}
+
+static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus);
+
+static void sysrq_handle_showallcpus(int key)
+{
+	/*
+	 * Fall back to the workqueue based printing if the
+	 * backtrace printing did not succeed or the
+	 * architecture has no support for it:
+	 */
+	if (!trigger_all_cpu_backtrace()) {
+		struct pt_regs *regs = get_irq_regs();
+
+		if (regs) {
+			printk(KERN_INFO "CPU%d:\n", smp_processor_id());
+			show_regs(regs);
+		}
+		schedule_work(&sysrq_showallcpus);
+	}
+}
+
+static struct sysrq_key_op sysrq_showallcpus_op = {
+	.handler	= sysrq_handle_showallcpus,
+	.help_msg	= "show-backtrace-all-active-cpus(L)",
+	.action_msg	= "Show backtrace of all active CPUs",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+#endif
+
+static void sysrq_handle_showregs(int key)
+{
+	struct pt_regs *regs = get_irq_regs();
+	if (regs)
+		show_regs(regs);
+	perf_event_print_debug();
+}
+static struct sysrq_key_op sysrq_showregs_op = {
+	.handler	= sysrq_handle_showregs,
+	.help_msg	= "show-registers(P)",
+	.action_msg	= "Show Regs",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+
+static void sysrq_handle_showstate(int key)
+{
+	show_state();
+}
+static struct sysrq_key_op sysrq_showstate_op = {
+	.handler	= sysrq_handle_showstate,
+	.help_msg	= "show-task-states(T)",
+	.action_msg	= "Show State",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+
+static void sysrq_handle_showstate_blocked(int key)
+{
+	show_state_filter(TASK_UNINTERRUPTIBLE);
+}
+static struct sysrq_key_op sysrq_showstate_blocked_op = {
+	.handler	= sysrq_handle_showstate_blocked,
+	.help_msg	= "show-blocked-tasks(W)",
+	.action_msg	= "Show Blocked State",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+
+#ifdef CONFIG_TRACING
+#include <linux/ftrace.h>
+
+static void sysrq_ftrace_dump(int key)
+{
+	ftrace_dump(DUMP_ALL);
+}
+static struct sysrq_key_op sysrq_ftrace_dump_op = {
+	.handler	= sysrq_ftrace_dump,
+	.help_msg	= "dump-ftrace-buffer(Z)",
+	.action_msg	= "Dump ftrace buffer",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+#else
+#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)NULL)
+#endif
+
+static void sysrq_handle_showmem(int key)
+{
+	show_mem();
+}
+static struct sysrq_key_op sysrq_showmem_op = {
+	.handler	= sysrq_handle_showmem,
+	.help_msg	= "show-memory-usage(M)",
+	.action_msg	= "Show Memory",
+	.enable_mask	= SYSRQ_ENABLE_DUMP,
+};
+
+/*
+ * Signal sysrq helper function.  Sends a signal to all user processes.
+ */
+static void send_sig_all(int sig)
+{
+	struct task_struct *p;
+
+	for_each_process(p) {
+		if (p->mm && !is_global_init(p))
+			/* Not swapper, init nor kernel thread */
+			force_sig(sig, p);
+	}
+}
+
+static void sysrq_handle_term(int key)
+{
+	send_sig_all(SIGTERM);
+	console_loglevel = 8;
+}
+static struct sysrq_key_op sysrq_term_op = {
+	.handler	= sysrq_handle_term,
+	.help_msg	= "terminate-all-tasks(E)",
+	.action_msg	= "Terminate All Tasks",
+	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
+};
+
+static void moom_callback(struct work_struct *ignored)
+{
+	out_of_memory(node_zonelist(0, GFP_KERNEL), GFP_KERNEL, 0, NULL);
+}
+
+static DECLARE_WORK(moom_work, moom_callback);
+
+static void sysrq_handle_moom(int key)
+{
+	schedule_work(&moom_work);
+}
+static struct sysrq_key_op sysrq_moom_op = {
+	.handler	= sysrq_handle_moom,
+	.help_msg	= "memory-full-oom-kill(F)",
+	.action_msg	= "Manual OOM execution",
+	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
+};
+
+#ifdef CONFIG_BLOCK
+static void sysrq_handle_thaw(int key)
+{
+	emergency_thaw_all();
+}
+static struct sysrq_key_op sysrq_thaw_op = {
+	.handler	= sysrq_handle_thaw,
+	.help_msg	= "thaw-filesystems(J)",
+	.action_msg	= "Emergency Thaw of all frozen filesystems",
+	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
+};
+#endif
+
+static void sysrq_handle_kill(int key)
+{
+	send_sig_all(SIGKILL);
+	console_loglevel = 8;
+}
+static struct sysrq_key_op sysrq_kill_op = {
+	.handler	= sysrq_handle_kill,
+	.help_msg	= "kill-all-tasks(I)",
+	.action_msg	= "Kill All Tasks",
+	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
+};
+
+static void sysrq_handle_unrt(int key)
+{
+	normalize_rt_tasks();
+}
+static struct sysrq_key_op sysrq_unrt_op = {
+	.handler	= sysrq_handle_unrt,
+	.help_msg	= "nice-all-RT-tasks(N)",
+	.action_msg	= "Nice All RT Tasks",
+	.enable_mask	= SYSRQ_ENABLE_RTNICE,
+};
+
+/* Key Operations table and lock */
+static DEFINE_SPINLOCK(sysrq_key_table_lock);
+
+static struct sysrq_key_op *sysrq_key_table[36] = {
+	&sysrq_loglevel_op,		/* 0 */
+	&sysrq_loglevel_op,		/* 1 */
+	&sysrq_loglevel_op,		/* 2 */
+	&sysrq_loglevel_op,		/* 3 */
+	&sysrq_loglevel_op,		/* 4 */
+	&sysrq_loglevel_op,		/* 5 */
+	&sysrq_loglevel_op,		/* 6 */
+	&sysrq_loglevel_op,		/* 7 */
+	&sysrq_loglevel_op,		/* 8 */
+	&sysrq_loglevel_op,		/* 9 */
+
+	/*
+	 * a: Don't use for system provided sysrqs, it is handled specially on
+	 * sparc and will never arrive.
+	 */
+	NULL,				/* a */
+	&sysrq_reboot_op,		/* b */
+	&sysrq_crash_op,		/* c & ibm_emac driver debug */
+	&sysrq_showlocks_op,		/* d */
+	&sysrq_term_op,			/* e */
+	&sysrq_moom_op,			/* f */
+	/* g: May be registered for the kernel debugger */
+	NULL,				/* g */
+	NULL,				/* h - reserved for help */
+	&sysrq_kill_op,			/* i */
+#ifdef CONFIG_BLOCK
+	&sysrq_thaw_op,			/* j */
+#else
+	NULL,				/* j */
+#endif
+	&sysrq_SAK_op,			/* k */
+#ifdef CONFIG_SMP
+	&sysrq_showallcpus_op,		/* l */
+#else
+	NULL,				/* l */
+#endif
+	&sysrq_showmem_op,		/* m */
+	&sysrq_unrt_op,			/* n */
+	/* o: This will often be registered as 'Off' at init time */
+	NULL,				/* o */
+	&sysrq_showregs_op,		/* p */
+	&sysrq_show_timers_op,		/* q */
+	&sysrq_unraw_op,		/* r */
+	&sysrq_sync_op,			/* s */
+	&sysrq_showstate_op,		/* t */
+	&sysrq_mountro_op,		/* u */
+	/* v: May be registered for frame buffer console restore */
+	NULL,				/* v */
+	&sysrq_showstate_blocked_op,	/* w */
+	/* x: May be registered on ppc/powerpc for xmon */
+	NULL,				/* x */
+	/* y: May be registered on sparc64 for global register dump */
+	NULL,				/* y */
+	&sysrq_ftrace_dump_op,		/* z */
+};
+
+/* key2index calculation, -1 on invalid index */
+static int sysrq_key_table_key2index(int key)
+{
+	int retval;
+
+	if ((key >= '0') && (key <= '9'))
+		retval = key - '0';
+	else if ((key >= 'a') && (key <= 'z'))
+		retval = key + 10 - 'a';
+	else
+		retval = -1;
+	return retval;
+}
+
+/*
+ * get and put functions for the table, exposed to modules.
+ */
+struct sysrq_key_op *__sysrq_get_key_op(int key)
+{
+        struct sysrq_key_op *op_p = NULL;
+        int i;
+
+	i = sysrq_key_table_key2index(key);
+	if (i != -1)
+	        op_p = sysrq_key_table[i];
+
+        return op_p;
+}
+
+static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
+{
+        int i = sysrq_key_table_key2index(key);
+
+        if (i != -1)
+                sysrq_key_table[i] = op_p;
+}
+
+void __handle_sysrq(int key, bool check_mask)
+{
+	struct sysrq_key_op *op_p;
+	int orig_log_level;
+	int i;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sysrq_key_table_lock, flags);
+	/*
+	 * Raise the apparent loglevel to maximum so that the sysrq header
+	 * is shown to provide the user with positive feedback.  We do not
+	 * simply emit this at KERN_EMERG as that would change message
+	 * routing in the consumers of /proc/kmsg.
+	 */
+	orig_log_level = console_loglevel;
+	console_loglevel = 7;
+	printk(KERN_INFO "SysRq : ");
+
+        op_p = __sysrq_get_key_op(key);
+        if (op_p) {
+		/*
+		 * Should we check for enabled operations (/proc/sysrq-trigger
+		 * should not) and is the invoked operation enabled?
+		 */
+		if (!check_mask || sysrq_on_mask(op_p->enable_mask)) {
+			printk("%s\n", op_p->action_msg);
+			console_loglevel = orig_log_level;
+			op_p->handler(key);
+		} else {
+			printk("This sysrq operation is disabled.\n");
+		}
+	} else {
+		printk("HELP : ");
+		/* Only print the help msg once per handler */
+		for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) {
+			if (sysrq_key_table[i]) {
+				int j;
+
+				for (j = 0; sysrq_key_table[i] !=
+						sysrq_key_table[j]; j++)
+					;
+				if (j != i)
+					continue;
+				printk("%s ", sysrq_key_table[i]->help_msg);
+			}
+		}
+		printk("\n");
+		console_loglevel = orig_log_level;
+	}
+	spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
+}
+
+void handle_sysrq(int key)
+{
+	if (sysrq_on())
+		__handle_sysrq(key, true);
+}
+EXPORT_SYMBOL(handle_sysrq);
+
+#ifdef CONFIG_INPUT
+
+/* Simple translation table for the SysRq keys */
+static const unsigned char sysrq_xlate[KEY_CNT] =
+        "\000\0331234567890-=\177\t"                    /* 0x00 - 0x0f */
+        "qwertyuiop[]\r\000as"                          /* 0x10 - 0x1f */
+        "dfghjkl;'`\000\\zxcv"                          /* 0x20 - 0x2f */
+        "bnm,./\000*\000 \000\201\202\203\204\205"      /* 0x30 - 0x3f */
+        "\206\207\210\211\212\000\000789-456+1"         /* 0x40 - 0x4f */
+        "230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */
+        "\r\000/";                                      /* 0x60 - 0x6f */
+
+struct sysrq_state {
+	struct input_handle handle;
+	struct work_struct reinject_work;
+	unsigned long key_down[BITS_TO_LONGS(KEY_CNT)];
+	unsigned int alt;
+	unsigned int alt_use;
+	bool active;
+	bool need_reinject;
+};
+
+static void sysrq_reinject_alt_sysrq(struct work_struct *work)
+{
+	struct sysrq_state *sysrq =
+			container_of(work, struct sysrq_state, reinject_work);
+	struct input_handle *handle = &sysrq->handle;
+	unsigned int alt_code = sysrq->alt_use;
+
+	if (sysrq->need_reinject) {
+		/* Simulate press and release of Alt + SysRq */
+		input_inject_event(handle, EV_KEY, alt_code, 1);
+		input_inject_event(handle, EV_KEY, KEY_SYSRQ, 1);
+		input_inject_event(handle, EV_SYN, SYN_REPORT, 1);
+
+		input_inject_event(handle, EV_KEY, KEY_SYSRQ, 0);
+		input_inject_event(handle, EV_KEY, alt_code, 0);
+		input_inject_event(handle, EV_SYN, SYN_REPORT, 1);
+	}
+}
+
+static bool sysrq_filter(struct input_handle *handle,
+			 unsigned int type, unsigned int code, int value)
+{
+	struct sysrq_state *sysrq = handle->private;
+	bool was_active = sysrq->active;
+	bool suppress;
+
+	switch (type) {
+
+	case EV_SYN:
+		suppress = false;
+		break;
+
+	case EV_KEY:
+		switch (code) {
+
+		case KEY_LEFTALT:
+		case KEY_RIGHTALT:
+			if (!value) {
+				/* One of ALTs is being released */
+				if (sysrq->active && code == sysrq->alt_use)
+					sysrq->active = false;
+
+				sysrq->alt = KEY_RESERVED;
+
+			} else if (value != 2) {
+				sysrq->alt = code;
+				sysrq->need_reinject = false;
+			}
+			break;
+
+		case KEY_SYSRQ:
+			if (value == 1 && sysrq->alt != KEY_RESERVED) {
+				sysrq->active = true;
+				sysrq->alt_use = sysrq->alt;
+				/*
+				 * If nothing else will be pressed we'll need
+				 * to * re-inject Alt-SysRq keysroke.
+				 */
+				sysrq->need_reinject = true;
+			}
+
+			/*
+			 * Pretend that sysrq was never pressed at all. This
+			 * is needed to properly handle KGDB which will try
+			 * to release all keys after exiting debugger. If we
+			 * do not clear key bit it KGDB will end up sending
+			 * release events for Alt and SysRq, potentially
+			 * triggering print screen function.
+			 */
+			if (sysrq->active)
+				clear_bit(KEY_SYSRQ, handle->dev->key);
+
+			break;
+
+		default:
+			if (sysrq->active && value && value != 2) {
+				sysrq->need_reinject = false;
+				__handle_sysrq(sysrq_xlate[code], true);
+			}
+			break;
+		}
+
+		suppress = sysrq->active;
+
+		if (!sysrq->active) {
+			/*
+			 * If we are not suppressing key presses keep track of
+			 * keyboard state so we can release keys that have been
+			 * pressed before entering SysRq mode.
+			 */
+			if (value)
+				set_bit(code, sysrq->key_down);
+			else
+				clear_bit(code, sysrq->key_down);
+
+			if (was_active)
+				schedule_work(&sysrq->reinject_work);
+
+		} else if (value == 0 &&
+			   test_and_clear_bit(code, sysrq->key_down)) {
+			/*
+			 * Pass on release events for keys that was pressed before
+			 * entering SysRq mode.
+			 */
+			suppress = false;
+		}
+		break;
+
+	default:
+		suppress = sysrq->active;
+		break;
+	}
+
+	return suppress;
+}
+
+static int sysrq_connect(struct input_handler *handler,
+			 struct input_dev *dev,
+			 const struct input_device_id *id)
+{
+	struct sysrq_state *sysrq;
+	int error;
+
+	sysrq = kzalloc(sizeof(struct sysrq_state), GFP_KERNEL);
+	if (!sysrq)
+		return -ENOMEM;
+
+	INIT_WORK(&sysrq->reinject_work, sysrq_reinject_alt_sysrq);
+
+	sysrq->handle.dev = dev;
+	sysrq->handle.handler = handler;
+	sysrq->handle.name = "sysrq";
+	sysrq->handle.private = sysrq;
+
+	error = input_register_handle(&sysrq->handle);
+	if (error) {
+		pr_err("Failed to register input sysrq handler, error %d\n",
+			error);
+		goto err_free;
+	}
+
+	error = input_open_device(&sysrq->handle);
+	if (error) {
+		pr_err("Failed to open input device, error %d\n", error);
+		goto err_unregister;
+	}
+
+	return 0;
+
+ err_unregister:
+	input_unregister_handle(&sysrq->handle);
+ err_free:
+	kfree(sysrq);
+	return error;
+}
+
+static void sysrq_disconnect(struct input_handle *handle)
+{
+	struct sysrq_state *sysrq = handle->private;
+
+	input_close_device(handle);
+	cancel_work_sync(&sysrq->reinject_work);
+	input_unregister_handle(handle);
+	kfree(sysrq);
+}
+
+/*
+ * We are matching on KEY_LEFTALT instead of KEY_SYSRQ because not all
+ * keyboards have SysRq key predefined and so user may add it to keymap
+ * later, but we expect all such keyboards to have left alt.
+ */
+static const struct input_device_id sysrq_ids[] = {
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
+				INPUT_DEVICE_ID_MATCH_KEYBIT,
+		.evbit = { BIT_MASK(EV_KEY) },
+		.keybit = { BIT_MASK(KEY_LEFTALT) },
+	},
+	{ },
+};
+
+static struct input_handler sysrq_handler = {
+	.filter		= sysrq_filter,
+	.connect	= sysrq_connect,
+	.disconnect	= sysrq_disconnect,
+	.name		= "sysrq",
+	.id_table	= sysrq_ids,
+};
+
+static bool sysrq_handler_registered;
+
+static inline void sysrq_register_handler(void)
+{
+	int error;
+
+	error = input_register_handler(&sysrq_handler);
+	if (error)
+		pr_err("Failed to register input handler, error %d", error);
+	else
+		sysrq_handler_registered = true;
+}
+
+static inline void sysrq_unregister_handler(void)
+{
+	if (sysrq_handler_registered) {
+		input_unregister_handler(&sysrq_handler);
+		sysrq_handler_registered = false;
+	}
+}
+
+#else
+
+static inline void sysrq_register_handler(void)
+{
+}
+
+static inline void sysrq_unregister_handler(void)
+{
+}
+
+#endif /* CONFIG_INPUT */
+
+int sysrq_toggle_support(int enable_mask)
+{
+	bool was_enabled = sysrq_on();
+
+	sysrq_enabled = enable_mask;
+
+	if (was_enabled != sysrq_on()) {
+		if (sysrq_on())
+			sysrq_register_handler();
+		else
+			sysrq_unregister_handler();
+	}
+
+	return 0;
+}
+
+static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
+                                struct sysrq_key_op *remove_op_p)
+{
+	int retval;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sysrq_key_table_lock, flags);
+	if (__sysrq_get_key_op(key) == remove_op_p) {
+		__sysrq_put_key_op(key, insert_op_p);
+		retval = 0;
+	} else {
+		retval = -1;
+	}
+	spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
+	return retval;
+}
+
+int register_sysrq_key(int key, struct sysrq_key_op *op_p)
+{
+	return __sysrq_swap_key_ops(key, op_p, NULL);
+}
+EXPORT_SYMBOL(register_sysrq_key);
+
+int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
+{
+	return __sysrq_swap_key_ops(key, NULL, op_p);
+}
+EXPORT_SYMBOL(unregister_sysrq_key);
+
+#ifdef CONFIG_PROC_FS
+/*
+ * writing 'C' to /proc/sysrq-trigger is like sysrq-C
+ */
+static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
+				   size_t count, loff_t *ppos)
+{
+	if (count) {
+		char c;
+
+		if (get_user(c, buf))
+			return -EFAULT;
+		__handle_sysrq(c, false);
+	}
+
+	return count;
+}
+
+static const struct file_operations proc_sysrq_trigger_operations = {
+	.write		= write_sysrq_trigger,
+	.llseek		= noop_llseek,
+};
+
+static void sysrq_init_procfs(void)
+{
+	if (!proc_create("sysrq-trigger", S_IWUSR, NULL,
+			 &proc_sysrq_trigger_operations))
+		pr_err("Failed to register proc interface\n");
+}
+
+#else
+
+static inline void sysrq_init_procfs(void)
+{
+}
+
+#endif /* CONFIG_PROC_FS */
+
+static int __init sysrq_init(void)
+{
+	sysrq_init_procfs();
+
+	if (sysrq_on())
+		sysrq_register_handler();
+
+	return 0;
+}
+module_init(sysrq_init);
diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c
new file mode 100644
index 0000000..f64582b
--- /dev/null
+++ b/drivers/tty/tty_audit.c
@@ -0,0 +1,358 @@
+/*
+ * Creating audit events from TTY input.
+ *
+ * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.  This copyrighted
+ * material is made available to anyone wishing to use, modify, copy, or
+ * redistribute it subject to the terms and conditions of the GNU General
+ * Public License v.2.
+ *
+ * Authors: Miloslav Trmac <mitr@redhat.com>
+ */
+
+#include <linux/audit.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+
+struct tty_audit_buf {
+	atomic_t count;
+	struct mutex mutex;	/* Protects all data below */
+	int major, minor;	/* The TTY which the data is from */
+	unsigned icanon:1;
+	size_t valid;
+	unsigned char *data;	/* Allocated size N_TTY_BUF_SIZE */
+};
+
+static struct tty_audit_buf *tty_audit_buf_alloc(int major, int minor,
+						 int icanon)
+{
+	struct tty_audit_buf *buf;
+
+	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		goto err;
+	buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
+	if (!buf->data)
+		goto err_buf;
+	atomic_set(&buf->count, 1);
+	mutex_init(&buf->mutex);
+	buf->major = major;
+	buf->minor = minor;
+	buf->icanon = icanon;
+	buf->valid = 0;
+	return buf;
+
+err_buf:
+	kfree(buf);
+err:
+	return NULL;
+}
+
+static void tty_audit_buf_free(struct tty_audit_buf *buf)
+{
+	WARN_ON(buf->valid != 0);
+	kfree(buf->data);
+	kfree(buf);
+}
+
+static void tty_audit_buf_put(struct tty_audit_buf *buf)
+{
+	if (atomic_dec_and_test(&buf->count))
+		tty_audit_buf_free(buf);
+}
+
+static void tty_audit_log(const char *description, struct task_struct *tsk,
+			  uid_t loginuid, unsigned sessionid, int major,
+			  int minor, unsigned char *data, size_t size)
+{
+	struct audit_buffer *ab;
+
+	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_TTY);
+	if (ab) {
+		char name[sizeof(tsk->comm)];
+		uid_t uid = task_uid(tsk);
+
+		audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u "
+				 "major=%d minor=%d comm=", description,
+				 tsk->pid, uid, loginuid, sessionid,
+				 major, minor);
+		get_task_comm(name, tsk);
+		audit_log_untrustedstring(ab, name);
+		audit_log_format(ab, " data=");
+		audit_log_n_hex(ab, data, size);
+		audit_log_end(ab);
+	}
+}
+
+/**
+ *	tty_audit_buf_push	-	Push buffered data out
+ *
+ *	Generate an audit message from the contents of @buf, which is owned by
+ *	@tsk with @loginuid.  @buf->mutex must be locked.
+ */
+static void tty_audit_buf_push(struct task_struct *tsk, uid_t loginuid,
+			       unsigned int sessionid,
+			       struct tty_audit_buf *buf)
+{
+	if (buf->valid == 0)
+		return;
+	if (audit_enabled == 0)
+		return;
+	tty_audit_log("tty", tsk, loginuid, sessionid, buf->major, buf->minor,
+		      buf->data, buf->valid);
+	buf->valid = 0;
+}
+
+/**
+ *	tty_audit_buf_push_current	-	Push buffered data out
+ *
+ *	Generate an audit message from the contents of @buf, which is owned by
+ *	the current task.  @buf->mutex must be locked.
+ */
+static void tty_audit_buf_push_current(struct tty_audit_buf *buf)
+{
+	uid_t auid = audit_get_loginuid(current);
+	unsigned int sessionid = audit_get_sessionid(current);
+	tty_audit_buf_push(current, auid, sessionid, buf);
+}
+
+/**
+ *	tty_audit_exit	-	Handle a task exit
+ *
+ *	Make sure all buffered data is written out and deallocate the buffer.
+ *	Only needs to be called if current->signal->tty_audit_buf != %NULL.
+ */
+void tty_audit_exit(void)
+{
+	struct tty_audit_buf *buf;
+
+	spin_lock_irq(&current->sighand->siglock);
+	buf = current->signal->tty_audit_buf;
+	current->signal->tty_audit_buf = NULL;
+	spin_unlock_irq(&current->sighand->siglock);
+	if (!buf)
+		return;
+
+	mutex_lock(&buf->mutex);
+	tty_audit_buf_push_current(buf);
+	mutex_unlock(&buf->mutex);
+
+	tty_audit_buf_put(buf);
+}
+
+/**
+ *	tty_audit_fork	-	Copy TTY audit state for a new task
+ *
+ *	Set up TTY audit state in @sig from current.  @sig needs no locking.
+ */
+void tty_audit_fork(struct signal_struct *sig)
+{
+	spin_lock_irq(&current->sighand->siglock);
+	sig->audit_tty = current->signal->audit_tty;
+	spin_unlock_irq(&current->sighand->siglock);
+}
+
+/**
+ *	tty_audit_tiocsti	-	Log TIOCSTI
+ */
+void tty_audit_tiocsti(struct tty_struct *tty, char ch)
+{
+	struct tty_audit_buf *buf;
+	int major, minor, should_audit;
+
+	spin_lock_irq(&current->sighand->siglock);
+	should_audit = current->signal->audit_tty;
+	buf = current->signal->tty_audit_buf;
+	if (buf)
+		atomic_inc(&buf->count);
+	spin_unlock_irq(&current->sighand->siglock);
+
+	major = tty->driver->major;
+	minor = tty->driver->minor_start + tty->index;
+	if (buf) {
+		mutex_lock(&buf->mutex);
+		if (buf->major == major && buf->minor == minor)
+			tty_audit_buf_push_current(buf);
+		mutex_unlock(&buf->mutex);
+		tty_audit_buf_put(buf);
+	}
+
+	if (should_audit && audit_enabled) {
+		uid_t auid;
+		unsigned int sessionid;
+
+		auid = audit_get_loginuid(current);
+		sessionid = audit_get_sessionid(current);
+		tty_audit_log("ioctl=TIOCSTI", current, auid, sessionid, major,
+			      minor, &ch, 1);
+	}
+}
+
+/**
+ * tty_audit_push_task	-	Flush task's pending audit data
+ * @tsk:		task pointer
+ * @loginuid:		sender login uid
+ * @sessionid:		sender session id
+ *
+ * Called with a ref on @tsk held. Try to lock sighand and get a
+ * reference to the tty audit buffer if available.
+ * Flush the buffer or return an appropriate error code.
+ */
+int tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid)
+{
+	struct tty_audit_buf *buf = ERR_PTR(-EPERM);
+	unsigned long flags;
+
+	if (!lock_task_sighand(tsk, &flags))
+		return -ESRCH;
+
+	if (tsk->signal->audit_tty) {
+		buf = tsk->signal->tty_audit_buf;
+		if (buf)
+			atomic_inc(&buf->count);
+	}
+	unlock_task_sighand(tsk, &flags);
+
+	/*
+	 * Return 0 when signal->audit_tty set
+	 * but tsk->signal->tty_audit_buf == NULL.
+	 */
+	if (!buf || IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	mutex_lock(&buf->mutex);
+	tty_audit_buf_push(tsk, loginuid, sessionid, buf);
+	mutex_unlock(&buf->mutex);
+
+	tty_audit_buf_put(buf);
+	return 0;
+}
+
+/**
+ *	tty_audit_buf_get	-	Get an audit buffer.
+ *
+ *	Get an audit buffer for @tty, allocate it if necessary.  Return %NULL
+ *	if TTY auditing is disabled or out of memory.  Otherwise, return a new
+ *	reference to the buffer.
+ */
+static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty)
+{
+	struct tty_audit_buf *buf, *buf2;
+
+	buf = NULL;
+	buf2 = NULL;
+	spin_lock_irq(&current->sighand->siglock);
+	if (likely(!current->signal->audit_tty))
+		goto out;
+	buf = current->signal->tty_audit_buf;
+	if (buf) {
+		atomic_inc(&buf->count);
+		goto out;
+	}
+	spin_unlock_irq(&current->sighand->siglock);
+
+	buf2 = tty_audit_buf_alloc(tty->driver->major,
+				   tty->driver->minor_start + tty->index,
+				   tty->icanon);
+	if (buf2 == NULL) {
+		audit_log_lost("out of memory in TTY auditing");
+		return NULL;
+	}
+
+	spin_lock_irq(&current->sighand->siglock);
+	if (!current->signal->audit_tty)
+		goto out;
+	buf = current->signal->tty_audit_buf;
+	if (!buf) {
+		current->signal->tty_audit_buf = buf2;
+		buf = buf2;
+		buf2 = NULL;
+	}
+	atomic_inc(&buf->count);
+	/* Fall through */
+ out:
+	spin_unlock_irq(&current->sighand->siglock);
+	if (buf2)
+		tty_audit_buf_free(buf2);
+	return buf;
+}
+
+/**
+ *	tty_audit_add_data	-	Add data for TTY auditing.
+ *
+ *	Audit @data of @size from @tty, if necessary.
+ */
+void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
+			size_t size)
+{
+	struct tty_audit_buf *buf;
+	int major, minor;
+
+	if (unlikely(size == 0))
+		return;
+
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY
+	    && tty->driver->subtype == PTY_TYPE_MASTER)
+		return;
+
+	buf = tty_audit_buf_get(tty);
+	if (!buf)
+		return;
+
+	mutex_lock(&buf->mutex);
+	major = tty->driver->major;
+	minor = tty->driver->minor_start + tty->index;
+	if (buf->major != major || buf->minor != minor
+	    || buf->icanon != tty->icanon) {
+		tty_audit_buf_push_current(buf);
+		buf->major = major;
+		buf->minor = minor;
+		buf->icanon = tty->icanon;
+	}
+	do {
+		size_t run;
+
+		run = N_TTY_BUF_SIZE - buf->valid;
+		if (run > size)
+			run = size;
+		memcpy(buf->data + buf->valid, data, run);
+		buf->valid += run;
+		data += run;
+		size -= run;
+		if (buf->valid == N_TTY_BUF_SIZE)
+			tty_audit_buf_push_current(buf);
+	} while (size != 0);
+	mutex_unlock(&buf->mutex);
+	tty_audit_buf_put(buf);
+}
+
+/**
+ *	tty_audit_push	-	Push buffered data out
+ *
+ *	Make sure no audit data is pending for @tty on the current process.
+ */
+void tty_audit_push(struct tty_struct *tty)
+{
+	struct tty_audit_buf *buf;
+
+	spin_lock_irq(&current->sighand->siglock);
+	if (likely(!current->signal->audit_tty)) {
+		spin_unlock_irq(&current->sighand->siglock);
+		return;
+	}
+	buf = current->signal->tty_audit_buf;
+	if (buf)
+		atomic_inc(&buf->count);
+	spin_unlock_irq(&current->sighand->siglock);
+
+	if (buf) {
+		int major, minor;
+
+		major = tty->driver->major;
+		minor = tty->driver->minor_start + tty->index;
+		mutex_lock(&buf->mutex);
+		if (buf->major == major && buf->minor == minor)
+			tty_audit_buf_push_current(buf);
+		mutex_unlock(&buf->mutex);
+		tty_audit_buf_put(buf);
+	}
+}
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
new file mode 100644
index 0000000..d8210ca
--- /dev/null
+++ b/drivers/tty/tty_buffer.c
@@ -0,0 +1,534 @@
+/*
+ * Tty buffer allocation management
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+
+/**
+ *	tty_buffer_free_all		-	free buffers used by a tty
+ *	@tty: tty to free from
+ *
+ *	Remove all the buffers pending on a tty whether queued with data
+ *	or in the free ring. Must be called when the tty is no longer in use
+ *
+ *	Locking: none
+ */
+
+void tty_buffer_free_all(struct tty_struct *tty)
+{
+	struct tty_buffer *thead;
+	while ((thead = tty->buf.head) != NULL) {
+		tty->buf.head = thead->next;
+		kfree(thead);
+	}
+	while ((thead = tty->buf.free) != NULL) {
+		tty->buf.free = thead->next;
+		kfree(thead);
+	}
+	tty->buf.tail = NULL;
+	tty->buf.memory_used = 0;
+}
+
+/**
+ *	tty_buffer_alloc	-	allocate a tty buffer
+ *	@tty: tty device
+ *	@size: desired size (characters)
+ *
+ *	Allocate a new tty buffer to hold the desired number of characters.
+ *	Return NULL if out of memory or the allocation would exceed the
+ *	per device queue
+ *
+ *	Locking: Caller must hold tty->buf.lock
+ */
+
+static struct tty_buffer *tty_buffer_alloc(struct tty_struct *tty, size_t size)
+{
+	struct tty_buffer *p;
+
+	if (tty->buf.memory_used + size > 65536)
+		return NULL;
+	p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC);
+	if (p == NULL)
+		return NULL;
+	p->used = 0;
+	p->size = size;
+	p->next = NULL;
+	p->commit = 0;
+	p->read = 0;
+	p->char_buf_ptr = (char *)(p->data);
+	p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size;
+	tty->buf.memory_used += size;
+	return p;
+}
+
+/**
+ *	tty_buffer_free		-	free a tty buffer
+ *	@tty: tty owning the buffer
+ *	@b: the buffer to free
+ *
+ *	Free a tty buffer, or add it to the free list according to our
+ *	internal strategy
+ *
+ *	Locking: Caller must hold tty->buf.lock
+ */
+
+static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
+{
+	/* Dumb strategy for now - should keep some stats */
+	tty->buf.memory_used -= b->size;
+	WARN_ON(tty->buf.memory_used < 0);
+
+	if (b->size >= 512)
+		kfree(b);
+	else {
+		b->next = tty->buf.free;
+		tty->buf.free = b;
+	}
+}
+
+/**
+ *	__tty_buffer_flush		-	flush full tty buffers
+ *	@tty: tty to flush
+ *
+ *	flush all the buffers containing receive data. Caller must
+ *	hold the buffer lock and must have ensured no parallel flush to
+ *	ldisc is running.
+ *
+ *	Locking: Caller must hold tty->buf.lock
+ */
+
+static void __tty_buffer_flush(struct tty_struct *tty)
+{
+	struct tty_buffer *thead;
+
+	while ((thead = tty->buf.head) != NULL) {
+		tty->buf.head = thead->next;
+		tty_buffer_free(tty, thead);
+	}
+	tty->buf.tail = NULL;
+}
+
+/**
+ *	tty_buffer_flush		-	flush full tty buffers
+ *	@tty: tty to flush
+ *
+ *	flush all the buffers containing receive data. If the buffer is
+ *	being processed by flush_to_ldisc then we defer the processing
+ *	to that function
+ *
+ *	Locking: none
+ */
+
+void tty_buffer_flush(struct tty_struct *tty)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&tty->buf.lock, flags);
+
+	/* If the data is being pushed to the tty layer then we can't
+	   process it here. Instead set a flag and the flush_to_ldisc
+	   path will process the flush request before it exits */
+	if (test_bit(TTY_FLUSHING, &tty->flags)) {
+		set_bit(TTY_FLUSHPENDING, &tty->flags);
+		spin_unlock_irqrestore(&tty->buf.lock, flags);
+		wait_event(tty->read_wait,
+				test_bit(TTY_FLUSHPENDING, &tty->flags) == 0);
+		return;
+	} else
+		__tty_buffer_flush(tty);
+	spin_unlock_irqrestore(&tty->buf.lock, flags);
+}
+
+/**
+ *	tty_buffer_find		-	find a free tty buffer
+ *	@tty: tty owning the buffer
+ *	@size: characters wanted
+ *
+ *	Locate an existing suitable tty buffer or if we are lacking one then
+ *	allocate a new one. We round our buffers off in 256 character chunks
+ *	to get better allocation behaviour.
+ *
+ *	Locking: Caller must hold tty->buf.lock
+ */
+
+static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
+{
+	struct tty_buffer **tbh = &tty->buf.free;
+	while ((*tbh) != NULL) {
+		struct tty_buffer *t = *tbh;
+		if (t->size >= size) {
+			*tbh = t->next;
+			t->next = NULL;
+			t->used = 0;
+			t->commit = 0;
+			t->read = 0;
+			tty->buf.memory_used += t->size;
+			return t;
+		}
+		tbh = &((*tbh)->next);
+	}
+	/* Round the buffer size out */
+	size = (size + 0xFF) & ~0xFF;
+	return tty_buffer_alloc(tty, size);
+	/* Should possibly check if this fails for the largest buffer we
+	   have queued and recycle that ? */
+}
+
+/**
+ *	tty_buffer_request_room		-	grow tty buffer if needed
+ *	@tty: tty structure
+ *	@size: size desired
+ *
+ *	Make at least size bytes of linear space available for the tty
+ *	buffer. If we fail return the size we managed to find.
+ *
+ *	Locking: Takes tty->buf.lock
+ */
+int tty_buffer_request_room(struct tty_struct *tty, size_t size)
+{
+	struct tty_buffer *b, *n;
+	int left;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tty->buf.lock, flags);
+
+	/* OPTIMISATION: We could keep a per tty "zero" sized buffer to
+	   remove this conditional if its worth it. This would be invisible
+	   to the callers */
+	if ((b = tty->buf.tail) != NULL)
+		left = b->size - b->used;
+	else
+		left = 0;
+
+	if (left < size) {
+		/* This is the slow path - looking for new buffers to use */
+		if ((n = tty_buffer_find(tty, size)) != NULL) {
+			if (b != NULL) {
+				b->next = n;
+				b->commit = b->used;
+			} else
+				tty->buf.head = n;
+			tty->buf.tail = n;
+		} else
+			size = left;
+	}
+
+	spin_unlock_irqrestore(&tty->buf.lock, flags);
+	return size;
+}
+EXPORT_SYMBOL_GPL(tty_buffer_request_room);
+
+/**
+ *	tty_insert_flip_string_fixed_flag - Add characters to the tty buffer
+ *	@tty: tty structure
+ *	@chars: characters
+ *	@flag: flag value for each character
+ *	@size: size
+ *
+ *	Queue a series of bytes to the tty buffering. All the characters
+ *	passed are marked with the supplied flag. Returns the number added.
+ *
+ *	Locking: Called functions may take tty->buf.lock
+ */
+
+int tty_insert_flip_string_fixed_flag(struct tty_struct *tty,
+		const unsigned char *chars, char flag, size_t size)
+{
+	int copied = 0;
+	do {
+		int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
+		int space = tty_buffer_request_room(tty, goal);
+		struct tty_buffer *tb = tty->buf.tail;
+		/* If there is no space then tb may be NULL */
+		if (unlikely(space == 0))
+			break;
+		memcpy(tb->char_buf_ptr + tb->used, chars, space);
+		memset(tb->flag_buf_ptr + tb->used, flag, space);
+		tb->used += space;
+		copied += space;
+		chars += space;
+		/* There is a small chance that we need to split the data over
+		   several buffers. If this is the case we must loop */
+	} while (unlikely(size > copied));
+	return copied;
+}
+EXPORT_SYMBOL(tty_insert_flip_string_fixed_flag);
+
+/**
+ *	tty_insert_flip_string_flags	-	Add characters to the tty buffer
+ *	@tty: tty structure
+ *	@chars: characters
+ *	@flags: flag bytes
+ *	@size: size
+ *
+ *	Queue a series of bytes to the tty buffering. For each character
+ *	the flags array indicates the status of the character. Returns the
+ *	number added.
+ *
+ *	Locking: Called functions may take tty->buf.lock
+ */
+
+int tty_insert_flip_string_flags(struct tty_struct *tty,
+		const unsigned char *chars, const char *flags, size_t size)
+{
+	int copied = 0;
+	do {
+		int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
+		int space = tty_buffer_request_room(tty, goal);
+		struct tty_buffer *tb = tty->buf.tail;
+		/* If there is no space then tb may be NULL */
+		if (unlikely(space == 0))
+			break;
+		memcpy(tb->char_buf_ptr + tb->used, chars, space);
+		memcpy(tb->flag_buf_ptr + tb->used, flags, space);
+		tb->used += space;
+		copied += space;
+		chars += space;
+		flags += space;
+		/* There is a small chance that we need to split the data over
+		   several buffers. If this is the case we must loop */
+	} while (unlikely(size > copied));
+	return copied;
+}
+EXPORT_SYMBOL(tty_insert_flip_string_flags);
+
+/**
+ *	tty_schedule_flip	-	push characters to ldisc
+ *	@tty: tty to push from
+ *
+ *	Takes any pending buffers and transfers their ownership to the
+ *	ldisc side of the queue. It then schedules those characters for
+ *	processing by the line discipline.
+ *
+ *	Locking: Takes tty->buf.lock
+ */
+
+void tty_schedule_flip(struct tty_struct *tty)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&tty->buf.lock, flags);
+	if (tty->buf.tail != NULL)
+		tty->buf.tail->commit = tty->buf.tail->used;
+	spin_unlock_irqrestore(&tty->buf.lock, flags);
+	schedule_delayed_work(&tty->buf.work, 1);
+}
+EXPORT_SYMBOL(tty_schedule_flip);
+
+/**
+ *	tty_prepare_flip_string		-	make room for characters
+ *	@tty: tty
+ *	@chars: return pointer for character write area
+ *	@size: desired size
+ *
+ *	Prepare a block of space in the buffer for data. Returns the length
+ *	available and buffer pointer to the space which is now allocated and
+ *	accounted for as ready for normal characters. This is used for drivers
+ *	that need their own block copy routines into the buffer. There is no
+ *	guarantee the buffer is a DMA target!
+ *
+ *	Locking: May call functions taking tty->buf.lock
+ */
+
+int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars,
+								size_t size)
+{
+	int space = tty_buffer_request_room(tty, size);
+	if (likely(space)) {
+		struct tty_buffer *tb = tty->buf.tail;
+		*chars = tb->char_buf_ptr + tb->used;
+		memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
+		tb->used += space;
+	}
+	return space;
+}
+EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
+
+/**
+ *	tty_prepare_flip_string_flags	-	make room for characters
+ *	@tty: tty
+ *	@chars: return pointer for character write area
+ *	@flags: return pointer for status flag write area
+ *	@size: desired size
+ *
+ *	Prepare a block of space in the buffer for data. Returns the length
+ *	available and buffer pointer to the space which is now allocated and
+ *	accounted for as ready for characters. This is used for drivers
+ *	that need their own block copy routines into the buffer. There is no
+ *	guarantee the buffer is a DMA target!
+ *
+ *	Locking: May call functions taking tty->buf.lock
+ */
+
+int tty_prepare_flip_string_flags(struct tty_struct *tty,
+			unsigned char **chars, char **flags, size_t size)
+{
+	int space = tty_buffer_request_room(tty, size);
+	if (likely(space)) {
+		struct tty_buffer *tb = tty->buf.tail;
+		*chars = tb->char_buf_ptr + tb->used;
+		*flags = tb->flag_buf_ptr + tb->used;
+		tb->used += space;
+	}
+	return space;
+}
+EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
+
+
+
+/**
+ *	flush_to_ldisc
+ *	@work: tty structure passed from work queue.
+ *
+ *	This routine is called out of the software interrupt to flush data
+ *	from the buffer chain to the line discipline.
+ *
+ *	Locking: holds tty->buf.lock to guard buffer list. Drops the lock
+ *	while invoking the line discipline receive_buf method. The
+ *	receive_buf method is single threaded for each tty instance.
+ */
+
+static void flush_to_ldisc(struct work_struct *work)
+{
+	struct tty_struct *tty =
+		container_of(work, struct tty_struct, buf.work.work);
+	unsigned long 	flags;
+	struct tty_ldisc *disc;
+
+	disc = tty_ldisc_ref(tty);
+	if (disc == NULL)	/*  !TTY_LDISC */
+		return;
+
+	spin_lock_irqsave(&tty->buf.lock, flags);
+
+	if (!test_and_set_bit(TTY_FLUSHING, &tty->flags)) {
+		struct tty_buffer *head, *tail = tty->buf.tail;
+		int seen_tail = 0;
+		while ((head = tty->buf.head) != NULL) {
+			int count;
+			char *char_buf;
+			unsigned char *flag_buf;
+
+			count = head->commit - head->read;
+			if (!count) {
+				if (head->next == NULL)
+					break;
+				/*
+				  There's a possibility tty might get new buffer
+				  added during the unlock window below. We could
+				  end up spinning in here forever hogging the CPU
+				  completely. To avoid this let's have a rest each
+				  time we processed the tail buffer.
+				*/
+				if (tail == head)
+					seen_tail = 1;
+				tty->buf.head = head->next;
+				tty_buffer_free(tty, head);
+				continue;
+			}
+			/* Ldisc or user is trying to flush the buffers
+			   we are feeding to the ldisc, stop feeding the
+			   line discipline as we want to empty the queue */
+			if (test_bit(TTY_FLUSHPENDING, &tty->flags))
+				break;
+			if (!tty->receive_room || seen_tail) {
+				schedule_delayed_work(&tty->buf.work, 1);
+				break;
+			}
+			if (count > tty->receive_room)
+				count = tty->receive_room;
+			char_buf = head->char_buf_ptr + head->read;
+			flag_buf = head->flag_buf_ptr + head->read;
+			head->read += count;
+			spin_unlock_irqrestore(&tty->buf.lock, flags);
+			disc->ops->receive_buf(tty, char_buf,
+							flag_buf, count);
+			spin_lock_irqsave(&tty->buf.lock, flags);
+		}
+		clear_bit(TTY_FLUSHING, &tty->flags);
+	}
+
+	/* We may have a deferred request to flush the input buffer,
+	   if so pull the chain under the lock and empty the queue */
+	if (test_bit(TTY_FLUSHPENDING, &tty->flags)) {
+		__tty_buffer_flush(tty);
+		clear_bit(TTY_FLUSHPENDING, &tty->flags);
+		wake_up(&tty->read_wait);
+	}
+	spin_unlock_irqrestore(&tty->buf.lock, flags);
+
+	tty_ldisc_deref(disc);
+}
+
+/**
+ *	tty_flush_to_ldisc
+ *	@tty: tty to push
+ *
+ *	Push the terminal flip buffers to the line discipline.
+ *
+ *	Must not be called from IRQ context.
+ */
+void tty_flush_to_ldisc(struct tty_struct *tty)
+{
+	flush_delayed_work(&tty->buf.work);
+}
+
+/**
+ *	tty_flip_buffer_push	-	terminal
+ *	@tty: tty to push
+ *
+ *	Queue a push of the terminal flip buffers to the line discipline. This
+ *	function must not be called from IRQ context if tty->low_latency is set.
+ *
+ *	In the event of the queue being busy for flipping the work will be
+ *	held off and retried later.
+ *
+ *	Locking: tty buffer lock. Driver locks in low latency mode.
+ */
+
+void tty_flip_buffer_push(struct tty_struct *tty)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&tty->buf.lock, flags);
+	if (tty->buf.tail != NULL)
+		tty->buf.tail->commit = tty->buf.tail->used;
+	spin_unlock_irqrestore(&tty->buf.lock, flags);
+
+	if (tty->low_latency)
+		flush_to_ldisc(&tty->buf.work.work);
+	else
+		schedule_delayed_work(&tty->buf.work, 1);
+}
+EXPORT_SYMBOL(tty_flip_buffer_push);
+
+/**
+ *	tty_buffer_init		-	prepare a tty buffer structure
+ *	@tty: tty to initialise
+ *
+ *	Set up the initial state of the buffer management for a tty device.
+ *	Must be called before the other tty buffer functions are used.
+ *
+ *	Locking: none
+ */
+
+void tty_buffer_init(struct tty_struct *tty)
+{
+	spin_lock_init(&tty->buf.lock);
+	tty->buf.head = NULL;
+	tty->buf.tail = NULL;
+	tty->buf.free = NULL;
+	tty->buf.memory_used = 0;
+	INIT_DELAYED_WORK(&tty->buf.work, flush_to_ldisc);
+}
+
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
new file mode 100644
index 0000000..c05c5af
--- /dev/null
+++ b/drivers/tty/tty_io.c
@@ -0,0 +1,3263 @@
+/*
+ *  linux/drivers/char/tty_io.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+/*
+ * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
+ * or rs-channels. It also implements echoing, cooked mode etc.
+ *
+ * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
+ *
+ * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
+ * tty_struct and tty_queue structures.  Previously there was an array
+ * of 256 tty_struct's which was statically allocated, and the
+ * tty_queue structures were allocated at boot time.  Both are now
+ * dynamically allocated only when the tty is open.
+ *
+ * Also restructured routines so that there is more of a separation
+ * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
+ * the low-level tty routines (serial.c, pty.c, console.c).  This
+ * makes for cleaner and more compact code.  -TYT, 9/17/92
+ *
+ * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
+ * which can be dynamically activated and de-activated by the line
+ * discipline handling modules (like SLIP).
+ *
+ * NOTE: pay no attention to the line discipline code (yet); its
+ * interface is still subject to change in this version...
+ * -- TYT, 1/31/92
+ *
+ * Added functionality to the OPOST tty handling.  No delays, but all
+ * other bits should be there.
+ *	-- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
+ *
+ * Rewrote canonical mode and added more termios flags.
+ * 	-- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
+ *
+ * Reorganized FASYNC support so mouse code can share it.
+ *	-- ctm@ardi.com, 9Sep95
+ *
+ * New TIOCLINUX variants added.
+ *	-- mj@k332.feld.cvut.cz, 19-Nov-95
+ *
+ * Restrict vt switching via ioctl()
+ *      -- grif@cs.ucr.edu, 5-Dec-95
+ *
+ * Move console and virtual terminal code to more appropriate files,
+ * implement CONFIG_VT and generalize console device interface.
+ *	-- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
+ *
+ * Rewrote tty_init_dev and tty_release_dev to eliminate races.
+ *	-- Bill Hawes <whawes@star.net>, June 97
+ *
+ * Added devfs support.
+ *      -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
+ *
+ * Added support for a Unix98-style ptmx device.
+ *      -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
+ *
+ * Reduced memory usage for older ARM systems
+ *      -- Russell King <rmk@arm.linux.org.uk>
+ *
+ * Move do_SAK() into process context.  Less stack use in devfs functions.
+ * alloc_tty_struct() always uses kmalloc()
+ *			 -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
+ */
+
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/devpts_fs.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/console.h>
+#include <linux/timer.h>
+#include <linux/ctype.h>
+#include <linux/kd.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/smp_lock.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/seq_file.h>
+#include <linux/serial.h>
+
+#include <linux/uaccess.h>
+#include <asm/system.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+
+#include <linux/kmod.h>
+#include <linux/nsproxy.h>
+
+#undef TTY_DEBUG_HANGUP
+
+#define TTY_PARANOIA_CHECK 1
+#define CHECK_TTY_COUNT 1
+
+struct ktermios tty_std_termios = {	/* for the benefit of tty drivers  */
+	.c_iflag = ICRNL | IXON,
+	.c_oflag = OPOST | ONLCR,
+	.c_cflag = B38400 | CS8 | CREAD | HUPCL,
+	.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
+		   ECHOCTL | ECHOKE | IEXTEN,
+	.c_cc = INIT_C_CC,
+	.c_ispeed = 38400,
+	.c_ospeed = 38400
+};
+
+EXPORT_SYMBOL(tty_std_termios);
+
+/* This list gets poked at by procfs and various bits of boot up code. This
+   could do with some rationalisation such as pulling the tty proc function
+   into this file */
+
+LIST_HEAD(tty_drivers);			/* linked list of tty drivers */
+
+/* Mutex to protect creating and releasing a tty. This is shared with
+   vt.c for deeply disgusting hack reasons */
+DEFINE_MUTEX(tty_mutex);
+EXPORT_SYMBOL(tty_mutex);
+
+/* Spinlock to protect the tty->tty_files list */
+DEFINE_SPINLOCK(tty_files_lock);
+
+static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
+static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *);
+ssize_t redirected_tty_write(struct file *, const char __user *,
+							size_t, loff_t *);
+static unsigned int tty_poll(struct file *, poll_table *);
+static int tty_open(struct inode *, struct file *);
+long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+#ifdef CONFIG_COMPAT
+static long tty_compat_ioctl(struct file *file, unsigned int cmd,
+				unsigned long arg);
+#else
+#define tty_compat_ioctl NULL
+#endif
+static int __tty_fasync(int fd, struct file *filp, int on);
+static int tty_fasync(int fd, struct file *filp, int on);
+static void release_tty(struct tty_struct *tty, int idx);
+static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
+static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
+
+/**
+ *	alloc_tty_struct	-	allocate a tty object
+ *
+ *	Return a new empty tty structure. The data fields have not
+ *	been initialized in any way but has been zeroed
+ *
+ *	Locking: none
+ */
+
+struct tty_struct *alloc_tty_struct(void)
+{
+	return kzalloc(sizeof(struct tty_struct), GFP_KERNEL);
+}
+
+/**
+ *	free_tty_struct		-	free a disused tty
+ *	@tty: tty struct to free
+ *
+ *	Free the write buffers, tty queue and tty memory itself.
+ *
+ *	Locking: none. Must be called after tty is definitely unused
+ */
+
+void free_tty_struct(struct tty_struct *tty)
+{
+	if (tty->dev)
+		put_device(tty->dev);
+	kfree(tty->write_buf);
+	tty_buffer_free_all(tty);
+	kfree(tty);
+}
+
+static inline struct tty_struct *file_tty(struct file *file)
+{
+	return ((struct tty_file_private *)file->private_data)->tty;
+}
+
+/* Associate a new file with the tty structure */
+int tty_add_file(struct tty_struct *tty, struct file *file)
+{
+	struct tty_file_private *priv;
+
+	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->tty = tty;
+	priv->file = file;
+	file->private_data = priv;
+
+	spin_lock(&tty_files_lock);
+	list_add(&priv->list, &tty->tty_files);
+	spin_unlock(&tty_files_lock);
+
+	return 0;
+}
+
+/* Delete file from its tty */
+void tty_del_file(struct file *file)
+{
+	struct tty_file_private *priv = file->private_data;
+
+	spin_lock(&tty_files_lock);
+	list_del(&priv->list);
+	spin_unlock(&tty_files_lock);
+	file->private_data = NULL;
+	kfree(priv);
+}
+
+
+#define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
+
+/**
+ *	tty_name	-	return tty naming
+ *	@tty: tty structure
+ *	@buf: buffer for output
+ *
+ *	Convert a tty structure into a name. The name reflects the kernel
+ *	naming policy and if udev is in use may not reflect user space
+ *
+ *	Locking: none
+ */
+
+char *tty_name(struct tty_struct *tty, char *buf)
+{
+	if (!tty) /* Hmm.  NULL pointer.  That's fun. */
+		strcpy(buf, "NULL tty");
+	else
+		strcpy(buf, tty->name);
+	return buf;
+}
+
+EXPORT_SYMBOL(tty_name);
+
+int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
+			      const char *routine)
+{
+#ifdef TTY_PARANOIA_CHECK
+	if (!tty) {
+		printk(KERN_WARNING
+			"null TTY for (%d:%d) in %s\n",
+			imajor(inode), iminor(inode), routine);
+		return 1;
+	}
+	if (tty->magic != TTY_MAGIC) {
+		printk(KERN_WARNING
+			"bad magic number for tty struct (%d:%d) in %s\n",
+			imajor(inode), iminor(inode), routine);
+		return 1;
+	}
+#endif
+	return 0;
+}
+
+static int check_tty_count(struct tty_struct *tty, const char *routine)
+{
+#ifdef CHECK_TTY_COUNT
+	struct list_head *p;
+	int count = 0;
+
+	spin_lock(&tty_files_lock);
+	list_for_each(p, &tty->tty_files) {
+		count++;
+	}
+	spin_unlock(&tty_files_lock);
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_SLAVE &&
+	    tty->link && tty->link->count)
+		count++;
+	if (tty->count != count) {
+		printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) "
+				    "!= #fd's(%d) in %s\n",
+		       tty->name, tty->count, count, routine);
+		return count;
+	}
+#endif
+	return 0;
+}
+
+/**
+ *	get_tty_driver		-	find device of a tty
+ *	@dev_t: device identifier
+ *	@index: returns the index of the tty
+ *
+ *	This routine returns a tty driver structure, given a device number
+ *	and also passes back the index number.
+ *
+ *	Locking: caller must hold tty_mutex
+ */
+
+static struct tty_driver *get_tty_driver(dev_t device, int *index)
+{
+	struct tty_driver *p;
+
+	list_for_each_entry(p, &tty_drivers, tty_drivers) {
+		dev_t base = MKDEV(p->major, p->minor_start);
+		if (device < base || device >= base + p->num)
+			continue;
+		*index = device - base;
+		return tty_driver_kref_get(p);
+	}
+	return NULL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+/**
+ *	tty_find_polling_driver	-	find device of a polled tty
+ *	@name: name string to match
+ *	@line: pointer to resulting tty line nr
+ *
+ *	This routine returns a tty driver structure, given a name
+ *	and the condition that the tty driver is capable of polled
+ *	operation.
+ */
+struct tty_driver *tty_find_polling_driver(char *name, int *line)
+{
+	struct tty_driver *p, *res = NULL;
+	int tty_line = 0;
+	int len;
+	char *str, *stp;
+
+	for (str = name; *str; str++)
+		if ((*str >= '0' && *str <= '9') || *str == ',')
+			break;
+	if (!*str)
+		return NULL;
+
+	len = str - name;
+	tty_line = simple_strtoul(str, &str, 10);
+
+	mutex_lock(&tty_mutex);
+	/* Search through the tty devices to look for a match */
+	list_for_each_entry(p, &tty_drivers, tty_drivers) {
+		if (strncmp(name, p->name, len) != 0)
+			continue;
+		stp = str;
+		if (*stp == ',')
+			stp++;
+		if (*stp == '\0')
+			stp = NULL;
+
+		if (tty_line >= 0 && tty_line < p->num && p->ops &&
+		    p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) {
+			res = tty_driver_kref_get(p);
+			*line = tty_line;
+			break;
+		}
+	}
+	mutex_unlock(&tty_mutex);
+
+	return res;
+}
+EXPORT_SYMBOL_GPL(tty_find_polling_driver);
+#endif
+
+/**
+ *	tty_check_change	-	check for POSIX terminal changes
+ *	@tty: tty to check
+ *
+ *	If we try to write to, or set the state of, a terminal and we're
+ *	not in the foreground, send a SIGTTOU.  If the signal is blocked or
+ *	ignored, go ahead and perform the operation.  (POSIX 7.2)
+ *
+ *	Locking: ctrl_lock
+ */
+
+int tty_check_change(struct tty_struct *tty)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (current->signal->tty != tty)
+		return 0;
+
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+
+	if (!tty->pgrp) {
+		printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n");
+		goto out_unlock;
+	}
+	if (task_pgrp(current) == tty->pgrp)
+		goto out_unlock;
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	if (is_ignored(SIGTTOU))
+		goto out;
+	if (is_current_pgrp_orphaned()) {
+		ret = -EIO;
+		goto out;
+	}
+	kill_pgrp(task_pgrp(current), SIGTTOU, 1);
+	set_thread_flag(TIF_SIGPENDING);
+	ret = -ERESTARTSYS;
+out:
+	return ret;
+out_unlock:
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	return ret;
+}
+
+EXPORT_SYMBOL(tty_check_change);
+
+static ssize_t hung_up_tty_read(struct file *file, char __user *buf,
+				size_t count, loff_t *ppos)
+{
+	return 0;
+}
+
+static ssize_t hung_up_tty_write(struct file *file, const char __user *buf,
+				 size_t count, loff_t *ppos)
+{
+	return -EIO;
+}
+
+/* No kernel lock held - none needed ;) */
+static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait)
+{
+	return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM;
+}
+
+static long hung_up_tty_ioctl(struct file *file, unsigned int cmd,
+		unsigned long arg)
+{
+	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
+}
+
+static long hung_up_tty_compat_ioctl(struct file *file,
+				     unsigned int cmd, unsigned long arg)
+{
+	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
+}
+
+static const struct file_operations tty_fops = {
+	.llseek		= no_llseek,
+	.read		= tty_read,
+	.write		= tty_write,
+	.poll		= tty_poll,
+	.unlocked_ioctl	= tty_ioctl,
+	.compat_ioctl	= tty_compat_ioctl,
+	.open		= tty_open,
+	.release	= tty_release,
+	.fasync		= tty_fasync,
+};
+
+static const struct file_operations console_fops = {
+	.llseek		= no_llseek,
+	.read		= tty_read,
+	.write		= redirected_tty_write,
+	.poll		= tty_poll,
+	.unlocked_ioctl	= tty_ioctl,
+	.compat_ioctl	= tty_compat_ioctl,
+	.open		= tty_open,
+	.release	= tty_release,
+	.fasync		= tty_fasync,
+};
+
+static const struct file_operations hung_up_tty_fops = {
+	.llseek		= no_llseek,
+	.read		= hung_up_tty_read,
+	.write		= hung_up_tty_write,
+	.poll		= hung_up_tty_poll,
+	.unlocked_ioctl	= hung_up_tty_ioctl,
+	.compat_ioctl	= hung_up_tty_compat_ioctl,
+	.release	= tty_release,
+};
+
+static DEFINE_SPINLOCK(redirect_lock);
+static struct file *redirect;
+
+/**
+ *	tty_wakeup	-	request more data
+ *	@tty: terminal
+ *
+ *	Internal and external helper for wakeups of tty. This function
+ *	informs the line discipline if present that the driver is ready
+ *	to receive more output data.
+ */
+
+void tty_wakeup(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld;
+
+	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
+		ld = tty_ldisc_ref(tty);
+		if (ld) {
+			if (ld->ops->write_wakeup)
+				ld->ops->write_wakeup(tty);
+			tty_ldisc_deref(ld);
+		}
+	}
+	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
+}
+
+EXPORT_SYMBOL_GPL(tty_wakeup);
+
+/**
+ *	__tty_hangup		-	actual handler for hangup events
+ *	@work: tty device
+ *
+ *	This can be called by the "eventd" kernel thread.  That is process
+ *	synchronous but doesn't hold any locks, so we need to make sure we
+ *	have the appropriate locks for what we're doing.
+ *
+ *	The hangup event clears any pending redirections onto the hung up
+ *	device. It ensures future writes will error and it does the needed
+ *	line discipline hangup and signal delivery. The tty object itself
+ *	remains intact.
+ *
+ *	Locking:
+ *		BTM
+ *		  redirect lock for undoing redirection
+ *		  file list lock for manipulating list of ttys
+ *		  tty_ldisc_lock from called functions
+ *		  termios_mutex resetting termios data
+ *		  tasklist_lock to walk task list for hangup event
+ *		    ->siglock to protect ->signal/->sighand
+ */
+void __tty_hangup(struct tty_struct *tty)
+{
+	struct file *cons_filp = NULL;
+	struct file *filp, *f = NULL;
+	struct task_struct *p;
+	struct tty_file_private *priv;
+	int    closecount = 0, n;
+	unsigned long flags;
+	int refs = 0;
+
+	if (!tty)
+		return;
+
+
+	spin_lock(&redirect_lock);
+	if (redirect && file_tty(redirect) == tty) {
+		f = redirect;
+		redirect = NULL;
+	}
+	spin_unlock(&redirect_lock);
+
+	tty_lock();
+
+	/* inuse_filps is protected by the single tty lock,
+	   this really needs to change if we want to flush the
+	   workqueue with the lock held */
+	check_tty_count(tty, "tty_hangup");
+
+	spin_lock(&tty_files_lock);
+	/* This breaks for file handles being sent over AF_UNIX sockets ? */
+	list_for_each_entry(priv, &tty->tty_files, list) {
+		filp = priv->file;
+		if (filp->f_op->write == redirected_tty_write)
+			cons_filp = filp;
+		if (filp->f_op->write != tty_write)
+			continue;
+		closecount++;
+		__tty_fasync(-1, filp, 0);	/* can't block */
+		filp->f_op = &hung_up_tty_fops;
+	}
+	spin_unlock(&tty_files_lock);
+
+	tty_ldisc_hangup(tty);
+
+	read_lock(&tasklist_lock);
+	if (tty->session) {
+		do_each_pid_task(tty->session, PIDTYPE_SID, p) {
+			spin_lock_irq(&p->sighand->siglock);
+			if (p->signal->tty == tty) {
+				p->signal->tty = NULL;
+				/* We defer the dereferences outside fo
+				   the tasklist lock */
+				refs++;
+			}
+			if (!p->signal->leader) {
+				spin_unlock_irq(&p->sighand->siglock);
+				continue;
+			}
+			__group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);
+			__group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);
+			put_pid(p->signal->tty_old_pgrp);  /* A noop */
+			spin_lock_irqsave(&tty->ctrl_lock, flags);
+			if (tty->pgrp)
+				p->signal->tty_old_pgrp = get_pid(tty->pgrp);
+			spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+			spin_unlock_irq(&p->sighand->siglock);
+		} while_each_pid_task(tty->session, PIDTYPE_SID, p);
+	}
+	read_unlock(&tasklist_lock);
+
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	clear_bit(TTY_THROTTLED, &tty->flags);
+	clear_bit(TTY_PUSH, &tty->flags);
+	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+	put_pid(tty->session);
+	put_pid(tty->pgrp);
+	tty->session = NULL;
+	tty->pgrp = NULL;
+	tty->ctrl_status = 0;
+	set_bit(TTY_HUPPED, &tty->flags);
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+	/* Account for the p->signal references we killed */
+	while (refs--)
+		tty_kref_put(tty);
+
+	/*
+	 * If one of the devices matches a console pointer, we
+	 * cannot just call hangup() because that will cause
+	 * tty->count and state->count to go out of sync.
+	 * So we just call close() the right number of times.
+	 */
+	if (cons_filp) {
+		if (tty->ops->close)
+			for (n = 0; n < closecount; n++)
+				tty->ops->close(tty, cons_filp);
+	} else if (tty->ops->hangup)
+		(tty->ops->hangup)(tty);
+	/*
+	 * We don't want to have driver/ldisc interactions beyond
+	 * the ones we did here. The driver layer expects no
+	 * calls after ->hangup() from the ldisc side. However we
+	 * can't yet guarantee all that.
+	 */
+	set_bit(TTY_HUPPED, &tty->flags);
+	tty_ldisc_enable(tty);
+
+	tty_unlock();
+
+	if (f)
+		fput(f);
+}
+
+static void do_tty_hangup(struct work_struct *work)
+{
+	struct tty_struct *tty =
+		container_of(work, struct tty_struct, hangup_work);
+
+	__tty_hangup(tty);
+}
+
+/**
+ *	tty_hangup		-	trigger a hangup event
+ *	@tty: tty to hangup
+ *
+ *	A carrier loss (virtual or otherwise) has occurred on this like
+ *	schedule a hangup sequence to run after this event.
+ */
+
+void tty_hangup(struct tty_struct *tty)
+{
+#ifdef TTY_DEBUG_HANGUP
+	char	buf[64];
+	printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf));
+#endif
+	schedule_work(&tty->hangup_work);
+}
+
+EXPORT_SYMBOL(tty_hangup);
+
+/**
+ *	tty_vhangup		-	process vhangup
+ *	@tty: tty to hangup
+ *
+ *	The user has asked via system call for the terminal to be hung up.
+ *	We do this synchronously so that when the syscall returns the process
+ *	is complete. That guarantee is necessary for security reasons.
+ */
+
+void tty_vhangup(struct tty_struct *tty)
+{
+#ifdef TTY_DEBUG_HANGUP
+	char	buf[64];
+
+	printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf));
+#endif
+	__tty_hangup(tty);
+}
+
+EXPORT_SYMBOL(tty_vhangup);
+
+
+/**
+ *	tty_vhangup_self	-	process vhangup for own ctty
+ *
+ *	Perform a vhangup on the current controlling tty
+ */
+
+void tty_vhangup_self(void)
+{
+	struct tty_struct *tty;
+
+	tty = get_current_tty();
+	if (tty) {
+		tty_vhangup(tty);
+		tty_kref_put(tty);
+	}
+}
+
+/**
+ *	tty_hung_up_p		-	was tty hung up
+ *	@filp: file pointer of tty
+ *
+ *	Return true if the tty has been subject to a vhangup or a carrier
+ *	loss
+ */
+
+int tty_hung_up_p(struct file *filp)
+{
+	return (filp->f_op == &hung_up_tty_fops);
+}
+
+EXPORT_SYMBOL(tty_hung_up_p);
+
+static void session_clear_tty(struct pid *session)
+{
+	struct task_struct *p;
+	do_each_pid_task(session, PIDTYPE_SID, p) {
+		proc_clear_tty(p);
+	} while_each_pid_task(session, PIDTYPE_SID, p);
+}
+
+/**
+ *	disassociate_ctty	-	disconnect controlling tty
+ *	@on_exit: true if exiting so need to "hang up" the session
+ *
+ *	This function is typically called only by the session leader, when
+ *	it wants to disassociate itself from its controlling tty.
+ *
+ *	It performs the following functions:
+ * 	(1)  Sends a SIGHUP and SIGCONT to the foreground process group
+ * 	(2)  Clears the tty from being controlling the session
+ * 	(3)  Clears the controlling tty for all processes in the
+ * 		session group.
+ *
+ *	The argument on_exit is set to 1 if called when a process is
+ *	exiting; it is 0 if called by the ioctl TIOCNOTTY.
+ *
+ *	Locking:
+ *		BTM is taken for hysterical raisins, and held when
+ *		  called from no_tty().
+ *		  tty_mutex is taken to protect tty
+ *		  ->siglock is taken to protect ->signal/->sighand
+ *		  tasklist_lock is taken to walk process list for sessions
+ *		    ->siglock is taken to protect ->signal/->sighand
+ */
+
+void disassociate_ctty(int on_exit)
+{
+	struct tty_struct *tty;
+	struct pid *tty_pgrp = NULL;
+
+	if (!current->signal->leader)
+		return;
+
+	tty = get_current_tty();
+	if (tty) {
+		tty_pgrp = get_pid(tty->pgrp);
+		if (on_exit) {
+			if (tty->driver->type != TTY_DRIVER_TYPE_PTY)
+				tty_vhangup(tty);
+		}
+		tty_kref_put(tty);
+	} else if (on_exit) {
+		struct pid *old_pgrp;
+		spin_lock_irq(&current->sighand->siglock);
+		old_pgrp = current->signal->tty_old_pgrp;
+		current->signal->tty_old_pgrp = NULL;
+		spin_unlock_irq(&current->sighand->siglock);
+		if (old_pgrp) {
+			kill_pgrp(old_pgrp, SIGHUP, on_exit);
+			kill_pgrp(old_pgrp, SIGCONT, on_exit);
+			put_pid(old_pgrp);
+		}
+		return;
+	}
+	if (tty_pgrp) {
+		kill_pgrp(tty_pgrp, SIGHUP, on_exit);
+		if (!on_exit)
+			kill_pgrp(tty_pgrp, SIGCONT, on_exit);
+		put_pid(tty_pgrp);
+	}
+
+	spin_lock_irq(&current->sighand->siglock);
+	put_pid(current->signal->tty_old_pgrp);
+	current->signal->tty_old_pgrp = NULL;
+	spin_unlock_irq(&current->sighand->siglock);
+
+	tty = get_current_tty();
+	if (tty) {
+		unsigned long flags;
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
+		put_pid(tty->session);
+		put_pid(tty->pgrp);
+		tty->session = NULL;
+		tty->pgrp = NULL;
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+		tty_kref_put(tty);
+	} else {
+#ifdef TTY_DEBUG_HANGUP
+		printk(KERN_DEBUG "error attempted to write to tty [0x%p]"
+		       " = NULL", tty);
+#endif
+	}
+
+	/* Now clear signal->tty under the lock */
+	read_lock(&tasklist_lock);
+	session_clear_tty(task_session(current));
+	read_unlock(&tasklist_lock);
+}
+
+/**
+ *
+ *	no_tty	- Ensure the current process does not have a controlling tty
+ */
+void no_tty(void)
+{
+	struct task_struct *tsk = current;
+	tty_lock();
+	disassociate_ctty(0);
+	tty_unlock();
+	proc_clear_tty(tsk);
+}
+
+
+/**
+ *	stop_tty	-	propagate flow control
+ *	@tty: tty to stop
+ *
+ *	Perform flow control to the driver. For PTY/TTY pairs we
+ *	must also propagate the TIOCKPKT status. May be called
+ *	on an already stopped device and will not re-call the driver
+ *	method.
+ *
+ *	This functionality is used by both the line disciplines for
+ *	halting incoming flow and by the driver. It may therefore be
+ *	called from any context, may be under the tty atomic_write_lock
+ *	but not always.
+ *
+ *	Locking:
+ *		Uses the tty control lock internally
+ */
+
+void stop_tty(struct tty_struct *tty)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	if (tty->stopped) {
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+		return;
+	}
+	tty->stopped = 1;
+	if (tty->link && tty->link->packet) {
+		tty->ctrl_status &= ~TIOCPKT_START;
+		tty->ctrl_status |= TIOCPKT_STOP;
+		wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
+	}
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	if (tty->ops->stop)
+		(tty->ops->stop)(tty);
+}
+
+EXPORT_SYMBOL(stop_tty);
+
+/**
+ *	start_tty	-	propagate flow control
+ *	@tty: tty to start
+ *
+ *	Start a tty that has been stopped if at all possible. Perform
+ *	any necessary wakeups and propagate the TIOCPKT status. If this
+ *	is the tty was previous stopped and is being started then the
+ *	driver start method is invoked and the line discipline woken.
+ *
+ *	Locking:
+ *		ctrl_lock
+ */
+
+void start_tty(struct tty_struct *tty)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	if (!tty->stopped || tty->flow_stopped) {
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+		return;
+	}
+	tty->stopped = 0;
+	if (tty->link && tty->link->packet) {
+		tty->ctrl_status &= ~TIOCPKT_STOP;
+		tty->ctrl_status |= TIOCPKT_START;
+		wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
+	}
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	if (tty->ops->start)
+		(tty->ops->start)(tty);
+	/* If we have a running line discipline it may need kicking */
+	tty_wakeup(tty);
+}
+
+EXPORT_SYMBOL(start_tty);
+
+/**
+ *	tty_read	-	read method for tty device files
+ *	@file: pointer to tty file
+ *	@buf: user buffer
+ *	@count: size of user buffer
+ *	@ppos: unused
+ *
+ *	Perform the read system call function on this terminal device. Checks
+ *	for hung up devices before calling the line discipline method.
+ *
+ *	Locking:
+ *		Locks the line discipline internally while needed. Multiple
+ *	read calls may be outstanding in parallel.
+ */
+
+static ssize_t tty_read(struct file *file, char __user *buf, size_t count,
+			loff_t *ppos)
+{
+	int i;
+	struct inode *inode = file->f_path.dentry->d_inode;
+	struct tty_struct *tty = file_tty(file);
+	struct tty_ldisc *ld;
+
+	if (tty_paranoia_check(tty, inode, "tty_read"))
+		return -EIO;
+	if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
+		return -EIO;
+
+	/* We want to wait for the line discipline to sort out in this
+	   situation */
+	ld = tty_ldisc_ref_wait(tty);
+	if (ld->ops->read)
+		i = (ld->ops->read)(tty, file, buf, count);
+	else
+		i = -EIO;
+	tty_ldisc_deref(ld);
+	if (i > 0)
+		inode->i_atime = current_fs_time(inode->i_sb);
+	return i;
+}
+
+void tty_write_unlock(struct tty_struct *tty)
+{
+	mutex_unlock(&tty->atomic_write_lock);
+	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
+}
+
+int tty_write_lock(struct tty_struct *tty, int ndelay)
+{
+	if (!mutex_trylock(&tty->atomic_write_lock)) {
+		if (ndelay)
+			return -EAGAIN;
+		if (mutex_lock_interruptible(&tty->atomic_write_lock))
+			return -ERESTARTSYS;
+	}
+	return 0;
+}
+
+/*
+ * Split writes up in sane blocksizes to avoid
+ * denial-of-service type attacks
+ */
+static inline ssize_t do_tty_write(
+	ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t),
+	struct tty_struct *tty,
+	struct file *file,
+	const char __user *buf,
+	size_t count)
+{
+	ssize_t ret, written = 0;
+	unsigned int chunk;
+
+	ret = tty_write_lock(tty, file->f_flags & O_NDELAY);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * We chunk up writes into a temporary buffer. This
+	 * simplifies low-level drivers immensely, since they
+	 * don't have locking issues and user mode accesses.
+	 *
+	 * But if TTY_NO_WRITE_SPLIT is set, we should use a
+	 * big chunk-size..
+	 *
+	 * The default chunk-size is 2kB, because the NTTY
+	 * layer has problems with bigger chunks. It will
+	 * claim to be able to handle more characters than
+	 * it actually does.
+	 *
+	 * FIXME: This can probably go away now except that 64K chunks
+	 * are too likely to fail unless switched to vmalloc...
+	 */
+	chunk = 2048;
+	if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags))
+		chunk = 65536;
+	if (count < chunk)
+		chunk = count;
+
+	/* write_buf/write_cnt is protected by the atomic_write_lock mutex */
+	if (tty->write_cnt < chunk) {
+		unsigned char *buf_chunk;
+
+		if (chunk < 1024)
+			chunk = 1024;
+
+		buf_chunk = kmalloc(chunk, GFP_KERNEL);
+		if (!buf_chunk) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		kfree(tty->write_buf);
+		tty->write_cnt = chunk;
+		tty->write_buf = buf_chunk;
+	}
+
+	/* Do the write .. */
+	for (;;) {
+		size_t size = count;
+		if (size > chunk)
+			size = chunk;
+		ret = -EFAULT;
+		if (copy_from_user(tty->write_buf, buf, size))
+			break;
+		ret = write(tty, file, tty->write_buf, size);
+		if (ret <= 0)
+			break;
+		written += ret;
+		buf += ret;
+		count -= ret;
+		if (!count)
+			break;
+		ret = -ERESTARTSYS;
+		if (signal_pending(current))
+			break;
+		cond_resched();
+	}
+	if (written) {
+		struct inode *inode = file->f_path.dentry->d_inode;
+		inode->i_mtime = current_fs_time(inode->i_sb);
+		ret = written;
+	}
+out:
+	tty_write_unlock(tty);
+	return ret;
+}
+
+/**
+ * tty_write_message - write a message to a certain tty, not just the console.
+ * @tty: the destination tty_struct
+ * @msg: the message to write
+ *
+ * This is used for messages that need to be redirected to a specific tty.
+ * We don't put it into the syslog queue right now maybe in the future if
+ * really needed.
+ *
+ * We must still hold the BTM and test the CLOSING flag for the moment.
+ */
+
+void tty_write_message(struct tty_struct *tty, char *msg)
+{
+	if (tty) {
+		mutex_lock(&tty->atomic_write_lock);
+		tty_lock();
+		if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) {
+			tty_unlock();
+			tty->ops->write(tty, msg, strlen(msg));
+		} else
+			tty_unlock();
+		tty_write_unlock(tty);
+	}
+	return;
+}
+
+
+/**
+ *	tty_write		-	write method for tty device file
+ *	@file: tty file pointer
+ *	@buf: user data to write
+ *	@count: bytes to write
+ *	@ppos: unused
+ *
+ *	Write data to a tty device via the line discipline.
+ *
+ *	Locking:
+ *		Locks the line discipline as required
+ *		Writes to the tty driver are serialized by the atomic_write_lock
+ *	and are then processed in chunks to the device. The line discipline
+ *	write method will not be invoked in parallel for each device.
+ */
+
+static ssize_t tty_write(struct file *file, const char __user *buf,
+						size_t count, loff_t *ppos)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	struct tty_struct *tty = file_tty(file);
+ 	struct tty_ldisc *ld;
+	ssize_t ret;
+
+	if (tty_paranoia_check(tty, inode, "tty_write"))
+		return -EIO;
+	if (!tty || !tty->ops->write ||
+		(test_bit(TTY_IO_ERROR, &tty->flags)))
+			return -EIO;
+	/* Short term debug to catch buggy drivers */
+	if (tty->ops->write_room == NULL)
+		printk(KERN_ERR "tty driver %s lacks a write_room method.\n",
+			tty->driver->name);
+	ld = tty_ldisc_ref_wait(tty);
+	if (!ld->ops->write)
+		ret = -EIO;
+	else
+		ret = do_tty_write(ld->ops->write, tty, file, buf, count);
+	tty_ldisc_deref(ld);
+	return ret;
+}
+
+ssize_t redirected_tty_write(struct file *file, const char __user *buf,
+						size_t count, loff_t *ppos)
+{
+	struct file *p = NULL;
+
+	spin_lock(&redirect_lock);
+	if (redirect) {
+		get_file(redirect);
+		p = redirect;
+	}
+	spin_unlock(&redirect_lock);
+
+	if (p) {
+		ssize_t res;
+		res = vfs_write(p, buf, count, &p->f_pos);
+		fput(p);
+		return res;
+	}
+	return tty_write(file, buf, count, ppos);
+}
+
+static char ptychar[] = "pqrstuvwxyzabcde";
+
+/**
+ *	pty_line_name	-	generate name for a pty
+ *	@driver: the tty driver in use
+ *	@index: the minor number
+ *	@p: output buffer of at least 6 bytes
+ *
+ *	Generate a name from a driver reference and write it to the output
+ *	buffer.
+ *
+ *	Locking: None
+ */
+static void pty_line_name(struct tty_driver *driver, int index, char *p)
+{
+	int i = index + driver->name_base;
+	/* ->name is initialized to "ttyp", but "tty" is expected */
+	sprintf(p, "%s%c%x",
+		driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name,
+		ptychar[i >> 4 & 0xf], i & 0xf);
+}
+
+/**
+ *	tty_line_name	-	generate name for a tty
+ *	@driver: the tty driver in use
+ *	@index: the minor number
+ *	@p: output buffer of at least 7 bytes
+ *
+ *	Generate a name from a driver reference and write it to the output
+ *	buffer.
+ *
+ *	Locking: None
+ */
+static void tty_line_name(struct tty_driver *driver, int index, char *p)
+{
+	sprintf(p, "%s%d", driver->name, index + driver->name_base);
+}
+
+/**
+ *	tty_driver_lookup_tty() - find an existing tty, if any
+ *	@driver: the driver for the tty
+ *	@idx:	 the minor number
+ *
+ *	Return the tty, if found or ERR_PTR() otherwise.
+ *
+ *	Locking: tty_mutex must be held. If tty is found, the mutex must
+ *	be held until the 'fast-open' is also done. Will change once we
+ *	have refcounting in the driver and per driver locking
+ */
+static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
+		struct inode *inode, int idx)
+{
+	struct tty_struct *tty;
+
+	if (driver->ops->lookup)
+		return driver->ops->lookup(driver, inode, idx);
+
+	tty = driver->ttys[idx];
+	return tty;
+}
+
+/**
+ *	tty_init_termios	-  helper for termios setup
+ *	@tty: the tty to set up
+ *
+ *	Initialise the termios structures for this tty. Thus runs under
+ *	the tty_mutex currently so we can be relaxed about ordering.
+ */
+
+int tty_init_termios(struct tty_struct *tty)
+{
+	struct ktermios *tp;
+	int idx = tty->index;
+
+	tp = tty->driver->termios[idx];
+	if (tp == NULL) {
+		tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
+		if (tp == NULL)
+			return -ENOMEM;
+		memcpy(tp, &tty->driver->init_termios,
+						sizeof(struct ktermios));
+		tty->driver->termios[idx] = tp;
+	}
+	tty->termios = tp;
+	tty->termios_locked = tp + 1;
+
+	/* Compatibility until drivers always set this */
+	tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
+	tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tty_init_termios);
+
+/**
+ *	tty_driver_install_tty() - install a tty entry in the driver
+ *	@driver: the driver for the tty
+ *	@tty: the tty
+ *
+ *	Install a tty object into the driver tables. The tty->index field
+ *	will be set by the time this is called. This method is responsible
+ *	for ensuring any need additional structures are allocated and
+ *	configured.
+ *
+ *	Locking: tty_mutex for now
+ */
+static int tty_driver_install_tty(struct tty_driver *driver,
+						struct tty_struct *tty)
+{
+	int idx = tty->index;
+	int ret;
+
+	if (driver->ops->install) {
+		ret = driver->ops->install(driver, tty);
+		return ret;
+	}
+
+	if (tty_init_termios(tty) == 0) {
+		tty_driver_kref_get(driver);
+		tty->count++;
+		driver->ttys[idx] = tty;
+		return 0;
+	}
+	return -ENOMEM;
+}
+
+/**
+ *	tty_driver_remove_tty() - remove a tty from the driver tables
+ *	@driver: the driver for the tty
+ *	@idx:	 the minor number
+ *
+ *	Remvoe a tty object from the driver tables. The tty->index field
+ *	will be set by the time this is called.
+ *
+ *	Locking: tty_mutex for now
+ */
+static void tty_driver_remove_tty(struct tty_driver *driver,
+						struct tty_struct *tty)
+{
+	if (driver->ops->remove)
+		driver->ops->remove(driver, tty);
+	else
+		driver->ttys[tty->index] = NULL;
+}
+
+/*
+ * 	tty_reopen()	- fast re-open of an open tty
+ * 	@tty	- the tty to open
+ *
+ *	Return 0 on success, -errno on error.
+ *
+ *	Locking: tty_mutex must be held from the time the tty was found
+ *		 till this open completes.
+ */
+static int tty_reopen(struct tty_struct *tty)
+{
+	struct tty_driver *driver = tty->driver;
+
+	if (test_bit(TTY_CLOSING, &tty->flags))
+		return -EIO;
+
+	if (driver->type == TTY_DRIVER_TYPE_PTY &&
+	    driver->subtype == PTY_TYPE_MASTER) {
+		/*
+		 * special case for PTY masters: only one open permitted,
+		 * and the slave side open count is incremented as well.
+		 */
+		if (tty->count)
+			return -EIO;
+
+		tty->link->count++;
+	}
+	tty->count++;
+	tty->driver = driver; /* N.B. why do this every time?? */
+
+	mutex_lock(&tty->ldisc_mutex);
+	WARN_ON(!test_bit(TTY_LDISC, &tty->flags));
+	mutex_unlock(&tty->ldisc_mutex);
+
+	return 0;
+}
+
+/**
+ *	tty_init_dev		-	initialise a tty device
+ *	@driver: tty driver we are opening a device on
+ *	@idx: device index
+ *	@ret_tty: returned tty structure
+ *	@first_ok: ok to open a new device (used by ptmx)
+ *
+ *	Prepare a tty device. This may not be a "new" clean device but
+ *	could also be an active device. The pty drivers require special
+ *	handling because of this.
+ *
+ *	Locking:
+ *		The function is called under the tty_mutex, which
+ *	protects us from the tty struct or driver itself going away.
+ *
+ *	On exit the tty device has the line discipline attached and
+ *	a reference count of 1. If a pair was created for pty/tty use
+ *	and the other was a pty master then it too has a reference count of 1.
+ *
+ * WSH 06/09/97: Rewritten to remove races and properly clean up after a
+ * failed open.  The new code protects the open with a mutex, so it's
+ * really quite straightforward.  The mutex locking can probably be
+ * relaxed for the (most common) case of reopening a tty.
+ */
+
+struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
+								int first_ok)
+{
+	struct tty_struct *tty;
+	int retval;
+
+	/* Check if pty master is being opened multiple times */
+	if (driver->subtype == PTY_TYPE_MASTER &&
+		(driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) {
+		return ERR_PTR(-EIO);
+	}
+
+	/*
+	 * First time open is complex, especially for PTY devices.
+	 * This code guarantees that either everything succeeds and the
+	 * TTY is ready for operation, or else the table slots are vacated
+	 * and the allocated memory released.  (Except that the termios
+	 * and locked termios may be retained.)
+	 */
+
+	if (!try_module_get(driver->owner))
+		return ERR_PTR(-ENODEV);
+
+	tty = alloc_tty_struct();
+	if (!tty)
+		goto fail_no_mem;
+	initialize_tty_struct(tty, driver, idx);
+
+	retval = tty_driver_install_tty(driver, tty);
+	if (retval < 0) {
+		free_tty_struct(tty);
+		module_put(driver->owner);
+		return ERR_PTR(retval);
+	}
+
+	/*
+	 * Structures all installed ... call the ldisc open routines.
+	 * If we fail here just call release_tty to clean up.  No need
+	 * to decrement the use counts, as release_tty doesn't care.
+	 */
+	retval = tty_ldisc_setup(tty, tty->link);
+	if (retval)
+		goto release_mem_out;
+	return tty;
+
+fail_no_mem:
+	module_put(driver->owner);
+	return ERR_PTR(-ENOMEM);
+
+	/* call the tty release_tty routine to clean out this slot */
+release_mem_out:
+	if (printk_ratelimit())
+		printk(KERN_INFO "tty_init_dev: ldisc open failed, "
+				 "clearing slot %d\n", idx);
+	release_tty(tty, idx);
+	return ERR_PTR(retval);
+}
+
+void tty_free_termios(struct tty_struct *tty)
+{
+	struct ktermios *tp;
+	int idx = tty->index;
+	/* Kill this flag and push into drivers for locking etc */
+	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
+		/* FIXME: Locking on ->termios array */
+		tp = tty->termios;
+		tty->driver->termios[idx] = NULL;
+		kfree(tp);
+	}
+}
+EXPORT_SYMBOL(tty_free_termios);
+
+void tty_shutdown(struct tty_struct *tty)
+{
+	tty_driver_remove_tty(tty->driver, tty);
+	tty_free_termios(tty);
+}
+EXPORT_SYMBOL(tty_shutdown);
+
+/**
+ *	release_one_tty		-	release tty structure memory
+ *	@kref: kref of tty we are obliterating
+ *
+ *	Releases memory associated with a tty structure, and clears out the
+ *	driver table slots. This function is called when a device is no longer
+ *	in use. It also gets called when setup of a device fails.
+ *
+ *	Locking:
+ *		tty_mutex - sometimes only
+ *		takes the file list lock internally when working on the list
+ *	of ttys that the driver keeps.
+ *
+ *	This method gets called from a work queue so that the driver private
+ *	cleanup ops can sleep (needed for USB at least)
+ */
+static void release_one_tty(struct work_struct *work)
+{
+	struct tty_struct *tty =
+		container_of(work, struct tty_struct, hangup_work);
+	struct tty_driver *driver = tty->driver;
+
+	if (tty->ops->cleanup)
+		tty->ops->cleanup(tty);
+
+	tty->magic = 0;
+	tty_driver_kref_put(driver);
+	module_put(driver->owner);
+
+	spin_lock(&tty_files_lock);
+	list_del_init(&tty->tty_files);
+	spin_unlock(&tty_files_lock);
+
+	put_pid(tty->pgrp);
+	put_pid(tty->session);
+	free_tty_struct(tty);
+}
+
+static void queue_release_one_tty(struct kref *kref)
+{
+	struct tty_struct *tty = container_of(kref, struct tty_struct, kref);
+
+	if (tty->ops->shutdown)
+		tty->ops->shutdown(tty);
+	else
+		tty_shutdown(tty);
+
+	/* The hangup queue is now free so we can reuse it rather than
+	   waste a chunk of memory for each port */
+	INIT_WORK(&tty->hangup_work, release_one_tty);
+	schedule_work(&tty->hangup_work);
+}
+
+/**
+ *	tty_kref_put		-	release a tty kref
+ *	@tty: tty device
+ *
+ *	Release a reference to a tty device and if need be let the kref
+ *	layer destruct the object for us
+ */
+
+void tty_kref_put(struct tty_struct *tty)
+{
+	if (tty)
+		kref_put(&tty->kref, queue_release_one_tty);
+}
+EXPORT_SYMBOL(tty_kref_put);
+
+/**
+ *	release_tty		-	release tty structure memory
+ *
+ *	Release both @tty and a possible linked partner (think pty pair),
+ *	and decrement the refcount of the backing module.
+ *
+ *	Locking:
+ *		tty_mutex - sometimes only
+ *		takes the file list lock internally when working on the list
+ *	of ttys that the driver keeps.
+ *		FIXME: should we require tty_mutex is held here ??
+ *
+ */
+static void release_tty(struct tty_struct *tty, int idx)
+{
+	/* This should always be true but check for the moment */
+	WARN_ON(tty->index != idx);
+
+	if (tty->link)
+		tty_kref_put(tty->link);
+	tty_kref_put(tty);
+}
+
+/**
+ *	tty_release		-	vfs callback for close
+ *	@inode: inode of tty
+ *	@filp: file pointer for handle to tty
+ *
+ *	Called the last time each file handle is closed that references
+ *	this tty. There may however be several such references.
+ *
+ *	Locking:
+ *		Takes bkl. See tty_release_dev
+ *
+ * Even releasing the tty structures is a tricky business.. We have
+ * to be very careful that the structures are all released at the
+ * same time, as interrupts might otherwise get the wrong pointers.
+ *
+ * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
+ * lead to double frees or releasing memory still in use.
+ */
+
+int tty_release(struct inode *inode, struct file *filp)
+{
+	struct tty_struct *tty = file_tty(filp);
+	struct tty_struct *o_tty;
+	int	pty_master, tty_closing, o_tty_closing, do_sleep;
+	int	devpts;
+	int	idx;
+	char	buf[64];
+
+	if (tty_paranoia_check(tty, inode, "tty_release_dev"))
+		return 0;
+
+	tty_lock();
+	check_tty_count(tty, "tty_release_dev");
+
+	__tty_fasync(-1, filp, 0);
+
+	idx = tty->index;
+	pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+		      tty->driver->subtype == PTY_TYPE_MASTER);
+	devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0;
+	o_tty = tty->link;
+
+#ifdef TTY_PARANOIA_CHECK
+	if (idx < 0 || idx >= tty->driver->num) {
+		printk(KERN_DEBUG "tty_release_dev: bad idx when trying to "
+				  "free (%s)\n", tty->name);
+		tty_unlock();
+		return 0;
+	}
+	if (!devpts) {
+		if (tty != tty->driver->ttys[idx]) {
+			tty_unlock();
+			printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty "
+			       "for (%s)\n", idx, tty->name);
+			return 0;
+		}
+		if (tty->termios != tty->driver->termios[idx]) {
+			tty_unlock();
+			printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios "
+			       "for (%s)\n",
+			       idx, tty->name);
+			return 0;
+		}
+	}
+#endif
+
+#ifdef TTY_DEBUG_HANGUP
+	printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...",
+	       tty_name(tty, buf), tty->count);
+#endif
+
+#ifdef TTY_PARANOIA_CHECK
+	if (tty->driver->other &&
+	     !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+		if (o_tty != tty->driver->other->ttys[idx]) {
+			tty_unlock();
+			printk(KERN_DEBUG "tty_release_dev: other->table[%d] "
+					  "not o_tty for (%s)\n",
+			       idx, tty->name);
+			return 0 ;
+		}
+		if (o_tty->termios != tty->driver->other->termios[idx]) {
+			tty_unlock();
+			printk(KERN_DEBUG "tty_release_dev: other->termios[%d] "
+					  "not o_termios for (%s)\n",
+			       idx, tty->name);
+			return 0;
+		}
+		if (o_tty->link != tty) {
+			tty_unlock();
+			printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n");
+			return 0;
+		}
+	}
+#endif
+	if (tty->ops->close)
+		tty->ops->close(tty, filp);
+
+	tty_unlock();
+	/*
+	 * Sanity check: if tty->count is going to zero, there shouldn't be
+	 * any waiters on tty->read_wait or tty->write_wait.  We test the
+	 * wait queues and kick everyone out _before_ actually starting to
+	 * close.  This ensures that we won't block while releasing the tty
+	 * structure.
+	 *
+	 * The test for the o_tty closing is necessary, since the master and
+	 * slave sides may close in any order.  If the slave side closes out
+	 * first, its count will be one, since the master side holds an open.
+	 * Thus this test wouldn't be triggered at the time the slave closes,
+	 * so we do it now.
+	 *
+	 * Note that it's possible for the tty to be opened again while we're
+	 * flushing out waiters.  By recalculating the closing flags before
+	 * each iteration we avoid any problems.
+	 */
+	while (1) {
+		/* Guard against races with tty->count changes elsewhere and
+		   opens on /dev/tty */
+
+		mutex_lock(&tty_mutex);
+		tty_lock();
+		tty_closing = tty->count <= 1;
+		o_tty_closing = o_tty &&
+			(o_tty->count <= (pty_master ? 1 : 0));
+		do_sleep = 0;
+
+		if (tty_closing) {
+			if (waitqueue_active(&tty->read_wait)) {
+				wake_up_poll(&tty->read_wait, POLLIN);
+				do_sleep++;
+			}
+			if (waitqueue_active(&tty->write_wait)) {
+				wake_up_poll(&tty->write_wait, POLLOUT);
+				do_sleep++;
+			}
+		}
+		if (o_tty_closing) {
+			if (waitqueue_active(&o_tty->read_wait)) {
+				wake_up_poll(&o_tty->read_wait, POLLIN);
+				do_sleep++;
+			}
+			if (waitqueue_active(&o_tty->write_wait)) {
+				wake_up_poll(&o_tty->write_wait, POLLOUT);
+				do_sleep++;
+			}
+		}
+		if (!do_sleep)
+			break;
+
+		printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue "
+				    "active!\n", tty_name(tty, buf));
+		tty_unlock();
+		mutex_unlock(&tty_mutex);
+		schedule();
+	}
+
+	/*
+	 * The closing flags are now consistent with the open counts on
+	 * both sides, and we've completed the last operation that could
+	 * block, so it's safe to proceed with closing.
+	 */
+	if (pty_master) {
+		if (--o_tty->count < 0) {
+			printk(KERN_WARNING "tty_release_dev: bad pty slave count "
+					    "(%d) for %s\n",
+			       o_tty->count, tty_name(o_tty, buf));
+			o_tty->count = 0;
+		}
+	}
+	if (--tty->count < 0) {
+		printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n",
+		       tty->count, tty_name(tty, buf));
+		tty->count = 0;
+	}
+
+	/*
+	 * We've decremented tty->count, so we need to remove this file
+	 * descriptor off the tty->tty_files list; this serves two
+	 * purposes:
+	 *  - check_tty_count sees the correct number of file descriptors
+	 *    associated with this tty.
+	 *  - do_tty_hangup no longer sees this file descriptor as
+	 *    something that needs to be handled for hangups.
+	 */
+	tty_del_file(filp);
+
+	/*
+	 * Perform some housekeeping before deciding whether to return.
+	 *
+	 * Set the TTY_CLOSING flag if this was the last open.  In the
+	 * case of a pty we may have to wait around for the other side
+	 * to close, and TTY_CLOSING makes sure we can't be reopened.
+	 */
+	if (tty_closing)
+		set_bit(TTY_CLOSING, &tty->flags);
+	if (o_tty_closing)
+		set_bit(TTY_CLOSING, &o_tty->flags);
+
+	/*
+	 * If _either_ side is closing, make sure there aren't any
+	 * processes that still think tty or o_tty is their controlling
+	 * tty.
+	 */
+	if (tty_closing || o_tty_closing) {
+		read_lock(&tasklist_lock);
+		session_clear_tty(tty->session);
+		if (o_tty)
+			session_clear_tty(o_tty->session);
+		read_unlock(&tasklist_lock);
+	}
+
+	mutex_unlock(&tty_mutex);
+
+	/* check whether both sides are closing ... */
+	if (!tty_closing || (o_tty && !o_tty_closing)) {
+		tty_unlock();
+		return 0;
+	}
+
+#ifdef TTY_DEBUG_HANGUP
+	printk(KERN_DEBUG "freeing tty structure...");
+#endif
+	/*
+	 * Ask the line discipline code to release its structures
+	 */
+	tty_ldisc_release(tty, o_tty);
+	/*
+	 * The release_tty function takes care of the details of clearing
+	 * the slots and preserving the termios structure.
+	 */
+	release_tty(tty, idx);
+
+	/* Make this pty number available for reallocation */
+	if (devpts)
+		devpts_kill_index(inode, idx);
+	tty_unlock();
+	return 0;
+}
+
+/**
+ *	tty_open		-	open a tty device
+ *	@inode: inode of device file
+ *	@filp: file pointer to tty
+ *
+ *	tty_open and tty_release keep up the tty count that contains the
+ *	number of opens done on a tty. We cannot use the inode-count, as
+ *	different inodes might point to the same tty.
+ *
+ *	Open-counting is needed for pty masters, as well as for keeping
+ *	track of serial lines: DTR is dropped when the last close happens.
+ *	(This is not done solely through tty->count, now.  - Ted 1/27/92)
+ *
+ *	The termios state of a pty is reset on first open so that
+ *	settings don't persist across reuse.
+ *
+ *	Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work.
+ *		 tty->count should protect the rest.
+ *		 ->siglock protects ->signal/->sighand
+ */
+
+static int tty_open(struct inode *inode, struct file *filp)
+{
+	struct tty_struct *tty = NULL;
+	int noctty, retval;
+	struct tty_driver *driver;
+	int index;
+	dev_t device = inode->i_rdev;
+	unsigned saved_flags = filp->f_flags;
+
+	nonseekable_open(inode, filp);
+
+retry_open:
+	noctty = filp->f_flags & O_NOCTTY;
+	index  = -1;
+	retval = 0;
+
+	mutex_lock(&tty_mutex);
+	tty_lock();
+
+	if (device == MKDEV(TTYAUX_MAJOR, 0)) {
+		tty = get_current_tty();
+		if (!tty) {
+			tty_unlock();
+			mutex_unlock(&tty_mutex);
+			return -ENXIO;
+		}
+		driver = tty_driver_kref_get(tty->driver);
+		index = tty->index;
+		filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
+		/* noctty = 1; */
+		/* FIXME: Should we take a driver reference ? */
+		tty_kref_put(tty);
+		goto got_driver;
+	}
+#ifdef CONFIG_VT
+	if (device == MKDEV(TTY_MAJOR, 0)) {
+		extern struct tty_driver *console_driver;
+		driver = tty_driver_kref_get(console_driver);
+		index = fg_console;
+		noctty = 1;
+		goto got_driver;
+	}
+#endif
+	if (device == MKDEV(TTYAUX_MAJOR, 1)) {
+		struct tty_driver *console_driver = console_device(&index);
+		if (console_driver) {
+			driver = tty_driver_kref_get(console_driver);
+			if (driver) {
+				/* Don't let /dev/console block */
+				filp->f_flags |= O_NONBLOCK;
+				noctty = 1;
+				goto got_driver;
+			}
+		}
+		tty_unlock();
+		mutex_unlock(&tty_mutex);
+		return -ENODEV;
+	}
+
+	driver = get_tty_driver(device, &index);
+	if (!driver) {
+		tty_unlock();
+		mutex_unlock(&tty_mutex);
+		return -ENODEV;
+	}
+got_driver:
+	if (!tty) {
+		/* check whether we're reopening an existing tty */
+		tty = tty_driver_lookup_tty(driver, inode, index);
+
+		if (IS_ERR(tty)) {
+			tty_unlock();
+			mutex_unlock(&tty_mutex);
+			return PTR_ERR(tty);
+		}
+	}
+
+	if (tty) {
+		retval = tty_reopen(tty);
+		if (retval)
+			tty = ERR_PTR(retval);
+	} else
+		tty = tty_init_dev(driver, index, 0);
+
+	mutex_unlock(&tty_mutex);
+	tty_driver_kref_put(driver);
+	if (IS_ERR(tty)) {
+		tty_unlock();
+		return PTR_ERR(tty);
+	}
+
+	retval = tty_add_file(tty, filp);
+	if (retval) {
+		tty_unlock();
+		return retval;
+	}
+
+	check_tty_count(tty, "tty_open");
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+		noctty = 1;
+#ifdef TTY_DEBUG_HANGUP
+	printk(KERN_DEBUG "opening %s...", tty->name);
+#endif
+	if (!retval) {
+		if (tty->ops->open)
+			retval = tty->ops->open(tty, filp);
+		else
+			retval = -ENODEV;
+	}
+	filp->f_flags = saved_flags;
+
+	if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) &&
+						!capable(CAP_SYS_ADMIN))
+		retval = -EBUSY;
+
+	if (retval) {
+#ifdef TTY_DEBUG_HANGUP
+		printk(KERN_DEBUG "error %d in opening %s...", retval,
+		       tty->name);
+#endif
+		tty_unlock(); /* need to call tty_release without BTM */
+		tty_release(inode, filp);
+		if (retval != -ERESTARTSYS)
+			return retval;
+
+		if (signal_pending(current))
+			return retval;
+
+		schedule();
+		/*
+		 * Need to reset f_op in case a hangup happened.
+		 */
+		tty_lock();
+		if (filp->f_op == &hung_up_tty_fops)
+			filp->f_op = &tty_fops;
+		tty_unlock();
+		goto retry_open;
+	}
+	tty_unlock();
+
+
+	mutex_lock(&tty_mutex);
+	tty_lock();
+	spin_lock_irq(&current->sighand->siglock);
+	if (!noctty &&
+	    current->signal->leader &&
+	    !current->signal->tty &&
+	    tty->session == NULL)
+		__proc_set_tty(current, tty);
+	spin_unlock_irq(&current->sighand->siglock);
+	tty_unlock();
+	mutex_unlock(&tty_mutex);
+	return 0;
+}
+
+
+
+/**
+ *	tty_poll	-	check tty status
+ *	@filp: file being polled
+ *	@wait: poll wait structures to update
+ *
+ *	Call the line discipline polling method to obtain the poll
+ *	status of the device.
+ *
+ *	Locking: locks called line discipline but ldisc poll method
+ *	may be re-entered freely by other callers.
+ */
+
+static unsigned int tty_poll(struct file *filp, poll_table *wait)
+{
+	struct tty_struct *tty = file_tty(filp);
+	struct tty_ldisc *ld;
+	int ret = 0;
+
+	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll"))
+		return 0;
+
+	ld = tty_ldisc_ref_wait(tty);
+	if (ld->ops->poll)
+		ret = (ld->ops->poll)(tty, filp, wait);
+	tty_ldisc_deref(ld);
+	return ret;
+}
+
+static int __tty_fasync(int fd, struct file *filp, int on)
+{
+	struct tty_struct *tty = file_tty(filp);
+	unsigned long flags;
+	int retval = 0;
+
+	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync"))
+		goto out;
+
+	retval = fasync_helper(fd, filp, on, &tty->fasync);
+	if (retval <= 0)
+		goto out;
+
+	if (on) {
+		enum pid_type type;
+		struct pid *pid;
+		if (!waitqueue_active(&tty->read_wait))
+			tty->minimum_to_wake = 1;
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
+		if (tty->pgrp) {
+			pid = tty->pgrp;
+			type = PIDTYPE_PGID;
+		} else {
+			pid = task_pid(current);
+			type = PIDTYPE_PID;
+		}
+		get_pid(pid);
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+		retval = __f_setown(filp, pid, type, 0);
+		put_pid(pid);
+		if (retval)
+			goto out;
+	} else {
+		if (!tty->fasync && !waitqueue_active(&tty->read_wait))
+			tty->minimum_to_wake = N_TTY_BUF_SIZE;
+	}
+	retval = 0;
+out:
+	return retval;
+}
+
+static int tty_fasync(int fd, struct file *filp, int on)
+{
+	int retval;
+	tty_lock();
+	retval = __tty_fasync(fd, filp, on);
+	tty_unlock();
+	return retval;
+}
+
+/**
+ *	tiocsti			-	fake input character
+ *	@tty: tty to fake input into
+ *	@p: pointer to character
+ *
+ *	Fake input to a tty device. Does the necessary locking and
+ *	input management.
+ *
+ *	FIXME: does not honour flow control ??
+ *
+ *	Locking:
+ *		Called functions take tty_ldisc_lock
+ *		current->signal->tty check is safe without locks
+ *
+ *	FIXME: may race normal receive processing
+ */
+
+static int tiocsti(struct tty_struct *tty, char __user *p)
+{
+	char ch, mbz = 0;
+	struct tty_ldisc *ld;
+
+	if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (get_user(ch, p))
+		return -EFAULT;
+	tty_audit_tiocsti(tty, ch);
+	ld = tty_ldisc_ref_wait(tty);
+	ld->ops->receive_buf(tty, &ch, &mbz, 1);
+	tty_ldisc_deref(ld);
+	return 0;
+}
+
+/**
+ *	tiocgwinsz		-	implement window query ioctl
+ *	@tty; tty
+ *	@arg: user buffer for result
+ *
+ *	Copies the kernel idea of the window size into the user buffer.
+ *
+ *	Locking: tty->termios_mutex is taken to ensure the winsize data
+ *		is consistent.
+ */
+
+static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
+{
+	int err;
+
+	mutex_lock(&tty->termios_mutex);
+	err = copy_to_user(arg, &tty->winsize, sizeof(*arg));
+	mutex_unlock(&tty->termios_mutex);
+
+	return err ? -EFAULT: 0;
+}
+
+/**
+ *	tty_do_resize		-	resize event
+ *	@tty: tty being resized
+ *	@rows: rows (character)
+ *	@cols: cols (character)
+ *
+ *	Update the termios variables and send the necessary signals to
+ *	peform a terminal resize correctly
+ */
+
+int tty_do_resize(struct tty_struct *tty, struct winsize *ws)
+{
+	struct pid *pgrp;
+	unsigned long flags;
+
+	/* Lock the tty */
+	mutex_lock(&tty->termios_mutex);
+	if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
+		goto done;
+	/* Get the PID values and reference them so we can
+	   avoid holding the tty ctrl lock while sending signals */
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	pgrp = get_pid(tty->pgrp);
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+	if (pgrp)
+		kill_pgrp(pgrp, SIGWINCH, 1);
+	put_pid(pgrp);
+
+	tty->winsize = *ws;
+done:
+	mutex_unlock(&tty->termios_mutex);
+	return 0;
+}
+
+/**
+ *	tiocswinsz		-	implement window size set ioctl
+ *	@tty; tty side of tty
+ *	@arg: user buffer for result
+ *
+ *	Copies the user idea of the window size to the kernel. Traditionally
+ *	this is just advisory information but for the Linux console it
+ *	actually has driver level meaning and triggers a VC resize.
+ *
+ *	Locking:
+ *		Driver dependant. The default do_resize method takes the
+ *	tty termios mutex and ctrl_lock. The console takes its own lock
+ *	then calls into the default method.
+ */
+
+static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg)
+{
+	struct winsize tmp_ws;
+	if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
+		return -EFAULT;
+
+	if (tty->ops->resize)
+		return tty->ops->resize(tty, &tmp_ws);
+	else
+		return tty_do_resize(tty, &tmp_ws);
+}
+
+/**
+ *	tioccons	-	allow admin to move logical console
+ *	@file: the file to become console
+ *
+ *	Allow the adminstrator to move the redirected console device
+ *
+ *	Locking: uses redirect_lock to guard the redirect information
+ */
+
+static int tioccons(struct file *file)
+{
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (file->f_op->write == redirected_tty_write) {
+		struct file *f;
+		spin_lock(&redirect_lock);
+		f = redirect;
+		redirect = NULL;
+		spin_unlock(&redirect_lock);
+		if (f)
+			fput(f);
+		return 0;
+	}
+	spin_lock(&redirect_lock);
+	if (redirect) {
+		spin_unlock(&redirect_lock);
+		return -EBUSY;
+	}
+	get_file(file);
+	redirect = file;
+	spin_unlock(&redirect_lock);
+	return 0;
+}
+
+/**
+ *	fionbio		-	non blocking ioctl
+ *	@file: file to set blocking value
+ *	@p: user parameter
+ *
+ *	Historical tty interfaces had a blocking control ioctl before
+ *	the generic functionality existed. This piece of history is preserved
+ *	in the expected tty API of posix OS's.
+ *
+ *	Locking: none, the open file handle ensures it won't go away.
+ */
+
+static int fionbio(struct file *file, int __user *p)
+{
+	int nonblock;
+
+	if (get_user(nonblock, p))
+		return -EFAULT;
+
+	spin_lock(&file->f_lock);
+	if (nonblock)
+		file->f_flags |= O_NONBLOCK;
+	else
+		file->f_flags &= ~O_NONBLOCK;
+	spin_unlock(&file->f_lock);
+	return 0;
+}
+
+/**
+ *	tiocsctty	-	set controlling tty
+ *	@tty: tty structure
+ *	@arg: user argument
+ *
+ *	This ioctl is used to manage job control. It permits a session
+ *	leader to set this tty as the controlling tty for the session.
+ *
+ *	Locking:
+ *		Takes tty_mutex() to protect tty instance
+ *		Takes tasklist_lock internally to walk sessions
+ *		Takes ->siglock() when updating signal->tty
+ */
+
+static int tiocsctty(struct tty_struct *tty, int arg)
+{
+	int ret = 0;
+	if (current->signal->leader && (task_session(current) == tty->session))
+		return ret;
+
+	mutex_lock(&tty_mutex);
+	/*
+	 * The process must be a session leader and
+	 * not have a controlling tty already.
+	 */
+	if (!current->signal->leader || current->signal->tty) {
+		ret = -EPERM;
+		goto unlock;
+	}
+
+	if (tty->session) {
+		/*
+		 * This tty is already the controlling
+		 * tty for another session group!
+		 */
+		if (arg == 1 && capable(CAP_SYS_ADMIN)) {
+			/*
+			 * Steal it away
+			 */
+			read_lock(&tasklist_lock);
+			session_clear_tty(tty->session);
+			read_unlock(&tasklist_lock);
+		} else {
+			ret = -EPERM;
+			goto unlock;
+		}
+	}
+	proc_set_tty(current, tty);
+unlock:
+	mutex_unlock(&tty_mutex);
+	return ret;
+}
+
+/**
+ *	tty_get_pgrp	-	return a ref counted pgrp pid
+ *	@tty: tty to read
+ *
+ *	Returns a refcounted instance of the pid struct for the process
+ *	group controlling the tty.
+ */
+
+struct pid *tty_get_pgrp(struct tty_struct *tty)
+{
+	unsigned long flags;
+	struct pid *pgrp;
+
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	pgrp = get_pid(tty->pgrp);
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+	return pgrp;
+}
+EXPORT_SYMBOL_GPL(tty_get_pgrp);
+
+/**
+ *	tiocgpgrp		-	get process group
+ *	@tty: tty passed by user
+ *	@real_tty: tty side of the tty pased by the user if a pty else the tty
+ *	@p: returned pid
+ *
+ *	Obtain the process group of the tty. If there is no process group
+ *	return an error.
+ *
+ *	Locking: none. Reference to current->signal->tty is safe.
+ */
+
+static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+	struct pid *pid;
+	int ret;
+	/*
+	 * (tty == real_tty) is a cheap way of
+	 * testing if the tty is NOT a master pty.
+	 */
+	if (tty == real_tty && current->signal->tty != real_tty)
+		return -ENOTTY;
+	pid = tty_get_pgrp(real_tty);
+	ret =  put_user(pid_vnr(pid), p);
+	put_pid(pid);
+	return ret;
+}
+
+/**
+ *	tiocspgrp		-	attempt to set process group
+ *	@tty: tty passed by user
+ *	@real_tty: tty side device matching tty passed by user
+ *	@p: pid pointer
+ *
+ *	Set the process group of the tty to the session passed. Only
+ *	permitted where the tty session is our session.
+ *
+ *	Locking: RCU, ctrl lock
+ */
+
+static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+	struct pid *pgrp;
+	pid_t pgrp_nr;
+	int retval = tty_check_change(real_tty);
+	unsigned long flags;
+
+	if (retval == -EIO)
+		return -ENOTTY;
+	if (retval)
+		return retval;
+	if (!current->signal->tty ||
+	    (current->signal->tty != real_tty) ||
+	    (real_tty->session != task_session(current)))
+		return -ENOTTY;
+	if (get_user(pgrp_nr, p))
+		return -EFAULT;
+	if (pgrp_nr < 0)
+		return -EINVAL;
+	rcu_read_lock();
+	pgrp = find_vpid(pgrp_nr);
+	retval = -ESRCH;
+	if (!pgrp)
+		goto out_unlock;
+	retval = -EPERM;
+	if (session_of_pgrp(pgrp) != task_session(current))
+		goto out_unlock;
+	retval = 0;
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	put_pid(real_tty->pgrp);
+	real_tty->pgrp = get_pid(pgrp);
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+out_unlock:
+	rcu_read_unlock();
+	return retval;
+}
+
+/**
+ *	tiocgsid		-	get session id
+ *	@tty: tty passed by user
+ *	@real_tty: tty side of the tty pased by the user if a pty else the tty
+ *	@p: pointer to returned session id
+ *
+ *	Obtain the session id of the tty. If there is no session
+ *	return an error.
+ *
+ *	Locking: none. Reference to current->signal->tty is safe.
+ */
+
+static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+	/*
+	 * (tty == real_tty) is a cheap way of
+	 * testing if the tty is NOT a master pty.
+	*/
+	if (tty == real_tty && current->signal->tty != real_tty)
+		return -ENOTTY;
+	if (!real_tty->session)
+		return -ENOTTY;
+	return put_user(pid_vnr(real_tty->session), p);
+}
+
+/**
+ *	tiocsetd	-	set line discipline
+ *	@tty: tty device
+ *	@p: pointer to user data
+ *
+ *	Set the line discipline according to user request.
+ *
+ *	Locking: see tty_set_ldisc, this function is just a helper
+ */
+
+static int tiocsetd(struct tty_struct *tty, int __user *p)
+{
+	int ldisc;
+	int ret;
+
+	if (get_user(ldisc, p))
+		return -EFAULT;
+
+	ret = tty_set_ldisc(tty, ldisc);
+
+	return ret;
+}
+
+/**
+ *	send_break	-	performed time break
+ *	@tty: device to break on
+ *	@duration: timeout in mS
+ *
+ *	Perform a timed break on hardware that lacks its own driver level
+ *	timed break functionality.
+ *
+ *	Locking:
+ *		atomic_write_lock serializes
+ *
+ */
+
+static int send_break(struct tty_struct *tty, unsigned int duration)
+{
+	int retval;
+
+	if (tty->ops->break_ctl == NULL)
+		return 0;
+
+	if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK)
+		retval = tty->ops->break_ctl(tty, duration);
+	else {
+		/* Do the work ourselves */
+		if (tty_write_lock(tty, 0) < 0)
+			return -EINTR;
+		retval = tty->ops->break_ctl(tty, -1);
+		if (retval)
+			goto out;
+		if (!signal_pending(current))
+			msleep_interruptible(duration);
+		retval = tty->ops->break_ctl(tty, 0);
+out:
+		tty_write_unlock(tty);
+		if (signal_pending(current))
+			retval = -EINTR;
+	}
+	return retval;
+}
+
+/**
+ *	tty_tiocmget		-	get modem status
+ *	@tty: tty device
+ *	@file: user file pointer
+ *	@p: pointer to result
+ *
+ *	Obtain the modem status bits from the tty driver if the feature
+ *	is supported. Return -EINVAL if it is not available.
+ *
+ *	Locking: none (up to the driver)
+ */
+
+static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p)
+{
+	int retval = -EINVAL;
+
+	if (tty->ops->tiocmget) {
+		retval = tty->ops->tiocmget(tty, file);
+
+		if (retval >= 0)
+			retval = put_user(retval, p);
+	}
+	return retval;
+}
+
+/**
+ *	tty_tiocmset		-	set modem status
+ *	@tty: tty device
+ *	@file: user file pointer
+ *	@cmd: command - clear bits, set bits or set all
+ *	@p: pointer to desired bits
+ *
+ *	Set the modem status bits from the tty driver if the feature
+ *	is supported. Return -EINVAL if it is not available.
+ *
+ *	Locking: none (up to the driver)
+ */
+
+static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd,
+	     unsigned __user *p)
+{
+	int retval;
+	unsigned int set, clear, val;
+
+	if (tty->ops->tiocmset == NULL)
+		return -EINVAL;
+
+	retval = get_user(val, p);
+	if (retval)
+		return retval;
+	set = clear = 0;
+	switch (cmd) {
+	case TIOCMBIS:
+		set = val;
+		break;
+	case TIOCMBIC:
+		clear = val;
+		break;
+	case TIOCMSET:
+		set = val;
+		clear = ~val;
+		break;
+	}
+	set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+	clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+	return tty->ops->tiocmset(tty, file, set, clear);
+}
+
+static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
+{
+	int retval = -EINVAL;
+	struct serial_icounter_struct icount;
+	memset(&icount, 0, sizeof(icount));
+	if (tty->ops->get_icount)
+		retval = tty->ops->get_icount(tty, &icount);
+	if (retval != 0)
+		return retval;
+	if (copy_to_user(arg, &icount, sizeof(icount)))
+		return -EFAULT;
+	return 0;
+}
+
+struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
+{
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+		tty = tty->link;
+	return tty;
+}
+EXPORT_SYMBOL(tty_pair_get_tty);
+
+struct tty_struct *tty_pair_get_pty(struct tty_struct *tty)
+{
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+	    return tty;
+	return tty->link;
+}
+EXPORT_SYMBOL(tty_pair_get_pty);
+
+/*
+ * Split this up, as gcc can choke on it otherwise..
+ */
+long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct tty_struct *tty = file_tty(file);
+	struct tty_struct *real_tty;
+	void __user *p = (void __user *)arg;
+	int retval;
+	struct tty_ldisc *ld;
+	struct inode *inode = file->f_dentry->d_inode;
+
+	if (tty_paranoia_check(tty, inode, "tty_ioctl"))
+		return -EINVAL;
+
+	real_tty = tty_pair_get_tty(tty);
+
+	/*
+	 * Factor out some common prep work
+	 */
+	switch (cmd) {
+	case TIOCSETD:
+	case TIOCSBRK:
+	case TIOCCBRK:
+	case TCSBRK:
+	case TCSBRKP:
+		retval = tty_check_change(tty);
+		if (retval)
+			return retval;
+		if (cmd != TIOCCBRK) {
+			tty_wait_until_sent(tty, 0);
+			if (signal_pending(current))
+				return -EINTR;
+		}
+		break;
+	}
+
+	/*
+	 *	Now do the stuff.
+	 */
+	switch (cmd) {
+	case TIOCSTI:
+		return tiocsti(tty, p);
+	case TIOCGWINSZ:
+		return tiocgwinsz(real_tty, p);
+	case TIOCSWINSZ:
+		return tiocswinsz(real_tty, p);
+	case TIOCCONS:
+		return real_tty != tty ? -EINVAL : tioccons(file);
+	case FIONBIO:
+		return fionbio(file, p);
+	case TIOCEXCL:
+		set_bit(TTY_EXCLUSIVE, &tty->flags);
+		return 0;
+	case TIOCNXCL:
+		clear_bit(TTY_EXCLUSIVE, &tty->flags);
+		return 0;
+	case TIOCNOTTY:
+		if (current->signal->tty != tty)
+			return -ENOTTY;
+		no_tty();
+		return 0;
+	case TIOCSCTTY:
+		return tiocsctty(tty, arg);
+	case TIOCGPGRP:
+		return tiocgpgrp(tty, real_tty, p);
+	case TIOCSPGRP:
+		return tiocspgrp(tty, real_tty, p);
+	case TIOCGSID:
+		return tiocgsid(tty, real_tty, p);
+	case TIOCGETD:
+		return put_user(tty->ldisc->ops->num, (int __user *)p);
+	case TIOCSETD:
+		return tiocsetd(tty, p);
+	/*
+	 * Break handling
+	 */
+	case TIOCSBRK:	/* Turn break on, unconditionally */
+		if (tty->ops->break_ctl)
+			return tty->ops->break_ctl(tty, -1);
+		return 0;
+	case TIOCCBRK:	/* Turn break off, unconditionally */
+		if (tty->ops->break_ctl)
+			return tty->ops->break_ctl(tty, 0);
+		return 0;
+	case TCSBRK:   /* SVID version: non-zero arg --> no break */
+		/* non-zero arg means wait for all output data
+		 * to be sent (performed above) but don't send break.
+		 * This is used by the tcdrain() termios function.
+		 */
+		if (!arg)
+			return send_break(tty, 250);
+		return 0;
+	case TCSBRKP:	/* support for POSIX tcsendbreak() */
+		return send_break(tty, arg ? arg*100 : 250);
+
+	case TIOCMGET:
+		return tty_tiocmget(tty, file, p);
+	case TIOCMSET:
+	case TIOCMBIC:
+	case TIOCMBIS:
+		return tty_tiocmset(tty, file, cmd, p);
+	case TIOCGICOUNT:
+		retval = tty_tiocgicount(tty, p);
+		/* For the moment allow fall through to the old method */
+        	if (retval != -EINVAL)
+			return retval;
+		break;
+	case TCFLSH:
+		switch (arg) {
+		case TCIFLUSH:
+		case TCIOFLUSH:
+		/* flush tty buffer and allow ldisc to process ioctl */
+			tty_buffer_flush(tty);
+			break;
+		}
+		break;
+	}
+	if (tty->ops->ioctl) {
+		retval = (tty->ops->ioctl)(tty, file, cmd, arg);
+		if (retval != -ENOIOCTLCMD)
+			return retval;
+	}
+	ld = tty_ldisc_ref_wait(tty);
+	retval = -EINVAL;
+	if (ld->ops->ioctl) {
+		retval = ld->ops->ioctl(tty, file, cmd, arg);
+		if (retval == -ENOIOCTLCMD)
+			retval = -EINVAL;
+	}
+	tty_ldisc_deref(ld);
+	return retval;
+}
+
+#ifdef CONFIG_COMPAT
+static long tty_compat_ioctl(struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	struct inode *inode = file->f_dentry->d_inode;
+	struct tty_struct *tty = file_tty(file);
+	struct tty_ldisc *ld;
+	int retval = -ENOIOCTLCMD;
+
+	if (tty_paranoia_check(tty, inode, "tty_ioctl"))
+		return -EINVAL;
+
+	if (tty->ops->compat_ioctl) {
+		retval = (tty->ops->compat_ioctl)(tty, file, cmd, arg);
+		if (retval != -ENOIOCTLCMD)
+			return retval;
+	}
+
+	ld = tty_ldisc_ref_wait(tty);
+	if (ld->ops->compat_ioctl)
+		retval = ld->ops->compat_ioctl(tty, file, cmd, arg);
+	tty_ldisc_deref(ld);
+
+	return retval;
+}
+#endif
+
+/*
+ * This implements the "Secure Attention Key" ---  the idea is to
+ * prevent trojan horses by killing all processes associated with this
+ * tty when the user hits the "Secure Attention Key".  Required for
+ * super-paranoid applications --- see the Orange Book for more details.
+ *
+ * This code could be nicer; ideally it should send a HUP, wait a few
+ * seconds, then send a INT, and then a KILL signal.  But you then
+ * have to coordinate with the init process, since all processes associated
+ * with the current tty must be dead before the new getty is allowed
+ * to spawn.
+ *
+ * Now, if it would be correct ;-/ The current code has a nasty hole -
+ * it doesn't catch files in flight. We may send the descriptor to ourselves
+ * via AF_UNIX socket, close it and later fetch from socket. FIXME.
+ *
+ * Nasty bug: do_SAK is being called in interrupt context.  This can
+ * deadlock.  We punt it up to process context.  AKPM - 16Mar2001
+ */
+void __do_SAK(struct tty_struct *tty)
+{
+#ifdef TTY_SOFT_SAK
+	tty_hangup(tty);
+#else
+	struct task_struct *g, *p;
+	struct pid *session;
+	int		i;
+	struct file	*filp;
+	struct fdtable *fdt;
+
+	if (!tty)
+		return;
+	session = tty->session;
+
+	tty_ldisc_flush(tty);
+
+	tty_driver_flush_buffer(tty);
+
+	read_lock(&tasklist_lock);
+	/* Kill the entire session */
+	do_each_pid_task(session, PIDTYPE_SID, p) {
+		printk(KERN_NOTICE "SAK: killed process %d"
+			" (%s): task_session(p)==tty->session\n",
+			task_pid_nr(p), p->comm);
+		send_sig(SIGKILL, p, 1);
+	} while_each_pid_task(session, PIDTYPE_SID, p);
+	/* Now kill any processes that happen to have the
+	 * tty open.
+	 */
+	do_each_thread(g, p) {
+		if (p->signal->tty == tty) {
+			printk(KERN_NOTICE "SAK: killed process %d"
+			    " (%s): task_session(p)==tty->session\n",
+			    task_pid_nr(p), p->comm);
+			send_sig(SIGKILL, p, 1);
+			continue;
+		}
+		task_lock(p);
+		if (p->files) {
+			/*
+			 * We don't take a ref to the file, so we must
+			 * hold ->file_lock instead.
+			 */
+			spin_lock(&p->files->file_lock);
+			fdt = files_fdtable(p->files);
+			for (i = 0; i < fdt->max_fds; i++) {
+				filp = fcheck_files(p->files, i);
+				if (!filp)
+					continue;
+				if (filp->f_op->read == tty_read &&
+				    file_tty(filp) == tty) {
+					printk(KERN_NOTICE "SAK: killed process %d"
+					    " (%s): fd#%d opened to the tty\n",
+					    task_pid_nr(p), p->comm, i);
+					force_sig(SIGKILL, p);
+					break;
+				}
+			}
+			spin_unlock(&p->files->file_lock);
+		}
+		task_unlock(p);
+	} while_each_thread(g, p);
+	read_unlock(&tasklist_lock);
+#endif
+}
+
+static void do_SAK_work(struct work_struct *work)
+{
+	struct tty_struct *tty =
+		container_of(work, struct tty_struct, SAK_work);
+	__do_SAK(tty);
+}
+
+/*
+ * The tq handling here is a little racy - tty->SAK_work may already be queued.
+ * Fortunately we don't need to worry, because if ->SAK_work is already queued,
+ * the values which we write to it will be identical to the values which it
+ * already has. --akpm
+ */
+void do_SAK(struct tty_struct *tty)
+{
+	if (!tty)
+		return;
+	schedule_work(&tty->SAK_work);
+}
+
+EXPORT_SYMBOL(do_SAK);
+
+static int dev_match_devt(struct device *dev, void *data)
+{
+	dev_t *devt = data;
+	return dev->devt == *devt;
+}
+
+/* Must put_device() after it's unused! */
+static struct device *tty_get_device(struct tty_struct *tty)
+{
+	dev_t devt = tty_devnum(tty);
+	return class_find_device(tty_class, NULL, &devt, dev_match_devt);
+}
+
+
+/**
+ *	initialize_tty_struct
+ *	@tty: tty to initialize
+ *
+ *	This subroutine initializes a tty structure that has been newly
+ *	allocated.
+ *
+ *	Locking: none - tty in question must not be exposed at this point
+ */
+
+void initialize_tty_struct(struct tty_struct *tty,
+		struct tty_driver *driver, int idx)
+{
+	memset(tty, 0, sizeof(struct tty_struct));
+	kref_init(&tty->kref);
+	tty->magic = TTY_MAGIC;
+	tty_ldisc_init(tty);
+	tty->session = NULL;
+	tty->pgrp = NULL;
+	tty->overrun_time = jiffies;
+	tty->buf.head = tty->buf.tail = NULL;
+	tty_buffer_init(tty);
+	mutex_init(&tty->termios_mutex);
+	mutex_init(&tty->ldisc_mutex);
+	init_waitqueue_head(&tty->write_wait);
+	init_waitqueue_head(&tty->read_wait);
+	INIT_WORK(&tty->hangup_work, do_tty_hangup);
+	mutex_init(&tty->atomic_read_lock);
+	mutex_init(&tty->atomic_write_lock);
+	mutex_init(&tty->output_lock);
+	mutex_init(&tty->echo_lock);
+	spin_lock_init(&tty->read_lock);
+	spin_lock_init(&tty->ctrl_lock);
+	INIT_LIST_HEAD(&tty->tty_files);
+	INIT_WORK(&tty->SAK_work, do_SAK_work);
+
+	tty->driver = driver;
+	tty->ops = driver->ops;
+	tty->index = idx;
+	tty_line_name(driver, idx, tty->name);
+	tty->dev = tty_get_device(tty);
+}
+
+/**
+ *	tty_put_char	-	write one character to a tty
+ *	@tty: tty
+ *	@ch: character
+ *
+ *	Write one byte to the tty using the provided put_char method
+ *	if present. Returns the number of characters successfully output.
+ *
+ *	Note: the specific put_char operation in the driver layer may go
+ *	away soon. Don't call it directly, use this method
+ */
+
+int tty_put_char(struct tty_struct *tty, unsigned char ch)
+{
+	if (tty->ops->put_char)
+		return tty->ops->put_char(tty, ch);
+	return tty->ops->write(tty, &ch, 1);
+}
+EXPORT_SYMBOL_GPL(tty_put_char);
+
+struct class *tty_class;
+
+/**
+ *	tty_register_device - register a tty device
+ *	@driver: the tty driver that describes the tty device
+ *	@index: the index in the tty driver for this tty device
+ *	@device: a struct device that is associated with this tty device.
+ *		This field is optional, if there is no known struct device
+ *		for this tty device it can be set to NULL safely.
+ *
+ *	Returns a pointer to the struct device for this tty device
+ *	(or ERR_PTR(-EFOO) on error).
+ *
+ *	This call is required to be made to register an individual tty device
+ *	if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set.  If
+ *	that bit is not set, this function should not be called by a tty
+ *	driver.
+ *
+ *	Locking: ??
+ */
+
+struct device *tty_register_device(struct tty_driver *driver, unsigned index,
+				   struct device *device)
+{
+	char name[64];
+	dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
+
+	if (index >= driver->num) {
+		printk(KERN_ERR "Attempt to register invalid tty line number "
+		       " (%d).\n", index);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (driver->type == TTY_DRIVER_TYPE_PTY)
+		pty_line_name(driver, index, name);
+	else
+		tty_line_name(driver, index, name);
+
+	return device_create(tty_class, device, dev, NULL, name);
+}
+EXPORT_SYMBOL(tty_register_device);
+
+/**
+ * 	tty_unregister_device - unregister a tty device
+ * 	@driver: the tty driver that describes the tty device
+ * 	@index: the index in the tty driver for this tty device
+ *
+ * 	If a tty device is registered with a call to tty_register_device() then
+ *	this function must be called when the tty device is gone.
+ *
+ *	Locking: ??
+ */
+
+void tty_unregister_device(struct tty_driver *driver, unsigned index)
+{
+	device_destroy(tty_class,
+		MKDEV(driver->major, driver->minor_start) + index);
+}
+EXPORT_SYMBOL(tty_unregister_device);
+
+struct tty_driver *alloc_tty_driver(int lines)
+{
+	struct tty_driver *driver;
+
+	driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL);
+	if (driver) {
+		kref_init(&driver->kref);
+		driver->magic = TTY_DRIVER_MAGIC;
+		driver->num = lines;
+		/* later we'll move allocation of tables here */
+	}
+	return driver;
+}
+EXPORT_SYMBOL(alloc_tty_driver);
+
+static void destruct_tty_driver(struct kref *kref)
+{
+	struct tty_driver *driver = container_of(kref, struct tty_driver, kref);
+	int i;
+	struct ktermios *tp;
+	void *p;
+
+	if (driver->flags & TTY_DRIVER_INSTALLED) {
+		/*
+		 * Free the termios and termios_locked structures because
+		 * we don't want to get memory leaks when modular tty
+		 * drivers are removed from the kernel.
+		 */
+		for (i = 0; i < driver->num; i++) {
+			tp = driver->termios[i];
+			if (tp) {
+				driver->termios[i] = NULL;
+				kfree(tp);
+			}
+			if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV))
+				tty_unregister_device(driver, i);
+		}
+		p = driver->ttys;
+		proc_tty_unregister_driver(driver);
+		driver->ttys = NULL;
+		driver->termios = NULL;
+		kfree(p);
+		cdev_del(&driver->cdev);
+	}
+	kfree(driver);
+}
+
+void tty_driver_kref_put(struct tty_driver *driver)
+{
+	kref_put(&driver->kref, destruct_tty_driver);
+}
+EXPORT_SYMBOL(tty_driver_kref_put);
+
+void tty_set_operations(struct tty_driver *driver,
+			const struct tty_operations *op)
+{
+	driver->ops = op;
+};
+EXPORT_SYMBOL(tty_set_operations);
+
+void put_tty_driver(struct tty_driver *d)
+{
+	tty_driver_kref_put(d);
+}
+EXPORT_SYMBOL(put_tty_driver);
+
+/*
+ * Called by a tty driver to register itself.
+ */
+int tty_register_driver(struct tty_driver *driver)
+{
+	int error;
+	int i;
+	dev_t dev;
+	void **p = NULL;
+	struct device *d;
+
+	if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
+		p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL);
+		if (!p)
+			return -ENOMEM;
+	}
+
+	if (!driver->major) {
+		error = alloc_chrdev_region(&dev, driver->minor_start,
+						driver->num, driver->name);
+		if (!error) {
+			driver->major = MAJOR(dev);
+			driver->minor_start = MINOR(dev);
+		}
+	} else {
+		dev = MKDEV(driver->major, driver->minor_start);
+		error = register_chrdev_region(dev, driver->num, driver->name);
+	}
+	if (error < 0) {
+		kfree(p);
+		return error;
+	}
+
+	if (p) {
+		driver->ttys = (struct tty_struct **)p;
+		driver->termios = (struct ktermios **)(p + driver->num);
+	} else {
+		driver->ttys = NULL;
+		driver->termios = NULL;
+	}
+
+	cdev_init(&driver->cdev, &tty_fops);
+	driver->cdev.owner = driver->owner;
+	error = cdev_add(&driver->cdev, dev, driver->num);
+	if (error) {
+		unregister_chrdev_region(dev, driver->num);
+		driver->ttys = NULL;
+		driver->termios = NULL;
+		kfree(p);
+		return error;
+	}
+
+	mutex_lock(&tty_mutex);
+	list_add(&driver->tty_drivers, &tty_drivers);
+	mutex_unlock(&tty_mutex);
+
+	if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) {
+		for (i = 0; i < driver->num; i++) {
+			d = tty_register_device(driver, i, NULL);
+			if (IS_ERR(d)) {
+				error = PTR_ERR(d);
+				goto err;
+			}
+		}
+	}
+	proc_tty_register_driver(driver);
+	driver->flags |= TTY_DRIVER_INSTALLED;
+	return 0;
+
+err:
+	for (i--; i >= 0; i--)
+		tty_unregister_device(driver, i);
+
+	mutex_lock(&tty_mutex);
+	list_del(&driver->tty_drivers);
+	mutex_unlock(&tty_mutex);
+
+	unregister_chrdev_region(dev, driver->num);
+	driver->ttys = NULL;
+	driver->termios = NULL;
+	kfree(p);
+	return error;
+}
+
+EXPORT_SYMBOL(tty_register_driver);
+
+/*
+ * Called by a tty driver to unregister itself.
+ */
+int tty_unregister_driver(struct tty_driver *driver)
+{
+#if 0
+	/* FIXME */
+	if (driver->refcount)
+		return -EBUSY;
+#endif
+	unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
+				driver->num);
+	mutex_lock(&tty_mutex);
+	list_del(&driver->tty_drivers);
+	mutex_unlock(&tty_mutex);
+	return 0;
+}
+
+EXPORT_SYMBOL(tty_unregister_driver);
+
+dev_t tty_devnum(struct tty_struct *tty)
+{
+	return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
+}
+EXPORT_SYMBOL(tty_devnum);
+
+void proc_clear_tty(struct task_struct *p)
+{
+	unsigned long flags;
+	struct tty_struct *tty;
+	spin_lock_irqsave(&p->sighand->siglock, flags);
+	tty = p->signal->tty;
+	p->signal->tty = NULL;
+	spin_unlock_irqrestore(&p->sighand->siglock, flags);
+	tty_kref_put(tty);
+}
+
+/* Called under the sighand lock */
+
+static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+{
+	if (tty) {
+		unsigned long flags;
+		/* We should not have a session or pgrp to put here but.... */
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
+		put_pid(tty->session);
+		put_pid(tty->pgrp);
+		tty->pgrp = get_pid(task_pgrp(tsk));
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+		tty->session = get_pid(task_session(tsk));
+		if (tsk->signal->tty) {
+			printk(KERN_DEBUG "tty not NULL!!\n");
+			tty_kref_put(tsk->signal->tty);
+		}
+	}
+	put_pid(tsk->signal->tty_old_pgrp);
+	tsk->signal->tty = tty_kref_get(tty);
+	tsk->signal->tty_old_pgrp = NULL;
+}
+
+static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+{
+	spin_lock_irq(&tsk->sighand->siglock);
+	__proc_set_tty(tsk, tty);
+	spin_unlock_irq(&tsk->sighand->siglock);
+}
+
+struct tty_struct *get_current_tty(void)
+{
+	struct tty_struct *tty;
+	unsigned long flags;
+
+	spin_lock_irqsave(&current->sighand->siglock, flags);
+	tty = tty_kref_get(current->signal->tty);
+	spin_unlock_irqrestore(&current->sighand->siglock, flags);
+	return tty;
+}
+EXPORT_SYMBOL_GPL(get_current_tty);
+
+void tty_default_fops(struct file_operations *fops)
+{
+	*fops = tty_fops;
+}
+
+/*
+ * Initialize the console device. This is called *early*, so
+ * we can't necessarily depend on lots of kernel help here.
+ * Just do some early initializations, and do the complex setup
+ * later.
+ */
+void __init console_init(void)
+{
+	initcall_t *call;
+
+	/* Setup the default TTY line discipline. */
+	tty_ldisc_begin();
+
+	/*
+	 * set up the console device so that later boot sequences can
+	 * inform about problems etc..
+	 */
+	call = __con_initcall_start;
+	while (call < __con_initcall_end) {
+		(*call)();
+		call++;
+	}
+}
+
+static char *tty_devnode(struct device *dev, mode_t *mode)
+{
+	if (!mode)
+		return NULL;
+	if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) ||
+	    dev->devt == MKDEV(TTYAUX_MAJOR, 2))
+		*mode = 0666;
+	return NULL;
+}
+
+static int __init tty_class_init(void)
+{
+	tty_class = class_create(THIS_MODULE, "tty");
+	if (IS_ERR(tty_class))
+		return PTR_ERR(tty_class);
+	tty_class->devnode = tty_devnode;
+	return 0;
+}
+
+postcore_initcall(tty_class_init);
+
+/* 3/2004 jmc: why do these devices exist? */
+
+static struct cdev tty_cdev, console_cdev;
+
+/*
+ * Ok, now we can initialize the rest of the tty devices and can count
+ * on memory allocations, interrupts etc..
+ */
+int __init tty_init(void)
+{
+	cdev_init(&tty_cdev, &tty_fops);
+	if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
+	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
+		panic("Couldn't register /dev/tty driver\n");
+	device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL,
+			      "tty");
+
+	cdev_init(&console_cdev, &console_fops);
+	if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
+	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
+		panic("Couldn't register /dev/console driver\n");
+	device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
+			      "console");
+
+#ifdef CONFIG_VT
+	vty_init(&console_fops);
+#endif
+	return 0;
+}
+
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
new file mode 100644
index 0000000..0c18899
--- /dev/null
+++ b/drivers/tty/tty_ioctl.c
@@ -0,0 +1,1179 @@
+/*
+ *  linux/drivers/char/tty_ioctl.c
+ *
+ *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
+ *
+ * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
+ * which can be dynamically activated and de-activated by the line
+ * discipline handling modules (like SLIP).
+ */
+
+#include <linux/types.h>
+#include <linux/termios.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/tty.h>
+#include <linux/fcntl.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/mutex.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#undef TTY_DEBUG_WAIT_UNTIL_SENT
+
+#undef	DEBUG
+
+/*
+ * Internal flag options for termios setting behavior
+ */
+#define TERMIOS_FLUSH	1
+#define TERMIOS_WAIT	2
+#define TERMIOS_TERMIO	4
+#define TERMIOS_OLD	8
+
+
+/**
+ *	tty_chars_in_buffer	-	characters pending
+ *	@tty: terminal
+ *
+ *	Return the number of bytes of data in the device private
+ *	output queue. If no private method is supplied there is assumed
+ *	to be no queue on the device.
+ */
+
+int tty_chars_in_buffer(struct tty_struct *tty)
+{
+	if (tty->ops->chars_in_buffer)
+		return tty->ops->chars_in_buffer(tty);
+	else
+		return 0;
+}
+EXPORT_SYMBOL(tty_chars_in_buffer);
+
+/**
+ *	tty_write_room		-	write queue space
+ *	@tty: terminal
+ *
+ *	Return the number of bytes that can be queued to this device
+ *	at the present time. The result should be treated as a guarantee
+ *	and the driver cannot offer a value it later shrinks by more than
+ *	the number of bytes written. If no method is provided 2K is always
+ *	returned and data may be lost as there will be no flow control.
+ */
+ 
+int tty_write_room(struct tty_struct *tty)
+{
+	if (tty->ops->write_room)
+		return tty->ops->write_room(tty);
+	return 2048;
+}
+EXPORT_SYMBOL(tty_write_room);
+
+/**
+ *	tty_driver_flush_buffer	-	discard internal buffer
+ *	@tty: terminal
+ *
+ *	Discard the internal output buffer for this device. If no method
+ *	is provided then either the buffer cannot be hardware flushed or
+ *	there is no buffer driver side.
+ */
+void tty_driver_flush_buffer(struct tty_struct *tty)
+{
+	if (tty->ops->flush_buffer)
+		tty->ops->flush_buffer(tty);
+}
+EXPORT_SYMBOL(tty_driver_flush_buffer);
+
+/**
+ *	tty_throttle		-	flow control
+ *	@tty: terminal
+ *
+ *	Indicate that a tty should stop transmitting data down the stack.
+ *	Takes the termios mutex to protect against parallel throttle/unthrottle
+ *	and also to ensure the driver can consistently reference its own
+ *	termios data at this point when implementing software flow control.
+ */
+
+void tty_throttle(struct tty_struct *tty)
+{
+	mutex_lock(&tty->termios_mutex);
+	/* check TTY_THROTTLED first so it indicates our state */
+	if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
+	    tty->ops->throttle)
+		tty->ops->throttle(tty);
+	mutex_unlock(&tty->termios_mutex);
+}
+EXPORT_SYMBOL(tty_throttle);
+
+/**
+ *	tty_unthrottle		-	flow control
+ *	@tty: terminal
+ *
+ *	Indicate that a tty may continue transmitting data down the stack.
+ *	Takes the termios mutex to protect against parallel throttle/unthrottle
+ *	and also to ensure the driver can consistently reference its own
+ *	termios data at this point when implementing software flow control.
+ *
+ *	Drivers should however remember that the stack can issue a throttle,
+ *	then change flow control method, then unthrottle.
+ */
+
+void tty_unthrottle(struct tty_struct *tty)
+{
+	mutex_lock(&tty->termios_mutex);
+	if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
+	    tty->ops->unthrottle)
+		tty->ops->unthrottle(tty);
+	mutex_unlock(&tty->termios_mutex);
+}
+EXPORT_SYMBOL(tty_unthrottle);
+
+/**
+ *	tty_wait_until_sent	-	wait for I/O to finish
+ *	@tty: tty we are waiting for
+ *	@timeout: how long we will wait
+ *
+ *	Wait for characters pending in a tty driver to hit the wire, or
+ *	for a timeout to occur (eg due to flow control)
+ *
+ *	Locking: none
+ */
+
+void tty_wait_until_sent(struct tty_struct *tty, long timeout)
+{
+#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
+	char buf[64];
+
+	printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
+#endif
+	if (!timeout)
+		timeout = MAX_SCHEDULE_TIMEOUT;
+	if (wait_event_interruptible_timeout(tty->write_wait,
+			!tty_chars_in_buffer(tty), timeout) >= 0) {
+		if (tty->ops->wait_until_sent)
+			tty->ops->wait_until_sent(tty, timeout);
+	}
+}
+EXPORT_SYMBOL(tty_wait_until_sent);
+
+
+/*
+ *		Termios Helper Methods
+ */
+
+static void unset_locked_termios(struct ktermios *termios,
+				 struct ktermios *old,
+				 struct ktermios *locked)
+{
+	int	i;
+
+#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
+
+	if (!locked) {
+		printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
+		return;
+	}
+
+	NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
+	NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
+	NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
+	NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
+	termios->c_line = locked->c_line ? old->c_line : termios->c_line;
+	for (i = 0; i < NCCS; i++)
+		termios->c_cc[i] = locked->c_cc[i] ?
+			old->c_cc[i] : termios->c_cc[i];
+	/* FIXME: What should we do for i/ospeed */
+}
+
+/*
+ * Routine which returns the baud rate of the tty
+ *
+ * Note that the baud_table needs to be kept in sync with the
+ * include/asm/termbits.h file.
+ */
+static const speed_t baud_table[] = {
+	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
+	9600, 19200, 38400, 57600, 115200, 230400, 460800,
+#ifdef __sparc__
+	76800, 153600, 307200, 614400, 921600
+#else
+	500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
+	2500000, 3000000, 3500000, 4000000
+#endif
+};
+
+#ifndef __sparc__
+static const tcflag_t baud_bits[] = {
+	B0, B50, B75, B110, B134, B150, B200, B300, B600,
+	B1200, B1800, B2400, B4800, B9600, B19200, B38400,
+	B57600, B115200, B230400, B460800, B500000, B576000,
+	B921600, B1000000, B1152000, B1500000, B2000000, B2500000,
+	B3000000, B3500000, B4000000
+};
+#else
+static const tcflag_t baud_bits[] = {
+	B0, B50, B75, B110, B134, B150, B200, B300, B600,
+	B1200, B1800, B2400, B4800, B9600, B19200, B38400,
+	B57600, B115200, B230400, B460800, B76800, B153600,
+	B307200, B614400, B921600
+};
+#endif
+
+static int n_baud_table = ARRAY_SIZE(baud_table);
+
+/**
+ *	tty_termios_baud_rate
+ *	@termios: termios structure
+ *
+ *	Convert termios baud rate data into a speed. This should be called
+ *	with the termios lock held if this termios is a terminal termios
+ *	structure. May change the termios data. Device drivers can call this
+ *	function but should use ->c_[io]speed directly as they are updated.
+ *
+ *	Locking: none
+ */
+
+speed_t tty_termios_baud_rate(struct ktermios *termios)
+{
+	unsigned int cbaud;
+
+	cbaud = termios->c_cflag & CBAUD;
+
+#ifdef BOTHER
+	/* Magic token for arbitary speed via c_ispeed/c_ospeed */
+	if (cbaud == BOTHER)
+		return termios->c_ospeed;
+#endif
+	if (cbaud & CBAUDEX) {
+		cbaud &= ~CBAUDEX;
+
+		if (cbaud < 1 || cbaud + 15 > n_baud_table)
+			termios->c_cflag &= ~CBAUDEX;
+		else
+			cbaud += 15;
+	}
+	return baud_table[cbaud];
+}
+EXPORT_SYMBOL(tty_termios_baud_rate);
+
+/**
+ *	tty_termios_input_baud_rate
+ *	@termios: termios structure
+ *
+ *	Convert termios baud rate data into a speed. This should be called
+ *	with the termios lock held if this termios is a terminal termios
+ *	structure. May change the termios data. Device drivers can call this
+ *	function but should use ->c_[io]speed directly as they are updated.
+ *
+ *	Locking: none
+ */
+
+speed_t tty_termios_input_baud_rate(struct ktermios *termios)
+{
+#ifdef IBSHIFT
+	unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
+
+	if (cbaud == B0)
+		return tty_termios_baud_rate(termios);
+
+	/* Magic token for arbitary speed via c_ispeed*/
+	if (cbaud == BOTHER)
+		return termios->c_ispeed;
+
+	if (cbaud & CBAUDEX) {
+		cbaud &= ~CBAUDEX;
+
+		if (cbaud < 1 || cbaud + 15 > n_baud_table)
+			termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
+		else
+			cbaud += 15;
+	}
+	return baud_table[cbaud];
+#else
+	return tty_termios_baud_rate(termios);
+#endif
+}
+EXPORT_SYMBOL(tty_termios_input_baud_rate);
+
+/**
+ *	tty_termios_encode_baud_rate
+ *	@termios: ktermios structure holding user requested state
+ *	@ispeed: input speed
+ *	@ospeed: output speed
+ *
+ *	Encode the speeds set into the passed termios structure. This is
+ *	used as a library helper for drivers os that they can report back
+ *	the actual speed selected when it differs from the speed requested
+ *
+ *	For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
+ *	we need to carefully set the bits when the user does not get the
+ *	desired speed. We allow small margins and preserve as much of possible
+ *	of the input intent to keep compatibility.
+ *
+ *	Locking: Caller should hold termios lock. This is already held
+ *	when calling this function from the driver termios handler.
+ *
+ *	The ifdefs deal with platforms whose owners have yet to update them
+ *	and will all go away once this is done.
+ */
+
+void tty_termios_encode_baud_rate(struct ktermios *termios,
+				  speed_t ibaud, speed_t obaud)
+{
+	int i = 0;
+	int ifound = -1, ofound = -1;
+	int iclose = ibaud/50, oclose = obaud/50;
+	int ibinput = 0;
+
+	if (obaud == 0)			/* CD dropped 		  */
+		ibaud = 0;		/* Clear ibaud to be sure */
+
+	termios->c_ispeed = ibaud;
+	termios->c_ospeed = obaud;
+
+#ifdef BOTHER
+	/* If the user asked for a precise weird speed give a precise weird
+	   answer. If they asked for a Bfoo speed they many have problems
+	   digesting non-exact replies so fuzz a bit */
+
+	if ((termios->c_cflag & CBAUD) == BOTHER)
+		oclose = 0;
+	if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
+		iclose = 0;
+	if ((termios->c_cflag >> IBSHIFT) & CBAUD)
+		ibinput = 1;	/* An input speed was specified */
+#endif
+	termios->c_cflag &= ~CBAUD;
+
+	/*
+	 *	Our goal is to find a close match to the standard baud rate
+	 *	returned. Walk the baud rate table and if we get a very close
+	 *	match then report back the speed as a POSIX Bxxxx value by
+	 *	preference
+	 */
+
+	do {
+		if (obaud - oclose <= baud_table[i] &&
+		    obaud + oclose >= baud_table[i]) {
+			termios->c_cflag |= baud_bits[i];
+			ofound = i;
+		}
+		if (ibaud - iclose <= baud_table[i] &&
+		    ibaud + iclose >= baud_table[i]) {
+			/* For the case input == output don't set IBAUD bits
+			   if the user didn't do so */
+			if (ofound == i && !ibinput)
+				ifound  = i;
+#ifdef IBSHIFT
+			else {
+				ifound = i;
+				termios->c_cflag |= (baud_bits[i] << IBSHIFT);
+			}
+#endif
+		}
+	} while (++i < n_baud_table);
+
+	/*
+	 *	If we found no match then use BOTHER if provided or warn
+	 *	the user their platform maintainer needs to wake up if not.
+	 */
+#ifdef BOTHER
+	if (ofound == -1)
+		termios->c_cflag |= BOTHER;
+	/* Set exact input bits only if the input and output differ or the
+	   user already did */
+	if (ifound == -1 && (ibaud != obaud || ibinput))
+		termios->c_cflag |= (BOTHER << IBSHIFT);
+#else
+	if (ifound == -1 || ofound == -1) {
+		printk_once(KERN_WARNING "tty: Unable to return correct "
+			  "speed data as your architecture needs updating.\n");
+	}
+#endif
+}
+EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
+
+/**
+ *	tty_encode_baud_rate		-	set baud rate of the tty
+ *	@ibaud: input baud rate
+ *	@obad: output baud rate
+ *
+ *	Update the current termios data for the tty with the new speed
+ *	settings. The caller must hold the termios_mutex for the tty in
+ *	question.
+ */
+
+void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
+{
+	tty_termios_encode_baud_rate(tty->termios, ibaud, obaud);
+}
+EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
+
+/**
+ *	tty_get_baud_rate	-	get tty bit rates
+ *	@tty: tty to query
+ *
+ *	Returns the baud rate as an integer for this terminal. The
+ *	termios lock must be held by the caller and the terminal bit
+ *	flags may be updated.
+ *
+ *	Locking: none
+ */
+
+speed_t tty_get_baud_rate(struct tty_struct *tty)
+{
+	speed_t baud = tty_termios_baud_rate(tty->termios);
+
+	if (baud == 38400 && tty->alt_speed) {
+		if (!tty->warned) {
+			printk(KERN_WARNING "Use of setserial/setrocket to "
+					    "set SPD_* flags is deprecated\n");
+			tty->warned = 1;
+		}
+		baud = tty->alt_speed;
+	}
+
+	return baud;
+}
+EXPORT_SYMBOL(tty_get_baud_rate);
+
+/**
+ *	tty_termios_copy_hw	-	copy hardware settings
+ *	@new: New termios
+ *	@old: Old termios
+ *
+ *	Propogate the hardware specific terminal setting bits from
+ *	the old termios structure to the new one. This is used in cases
+ *	where the hardware does not support reconfiguration or as a helper
+ *	in some cases where only minimal reconfiguration is supported
+ */
+
+void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
+{
+	/* The bits a dumb device handles in software. Smart devices need
+	   to always provide a set_termios method */
+	new->c_cflag &= HUPCL | CREAD | CLOCAL;
+	new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
+	new->c_ispeed = old->c_ispeed;
+	new->c_ospeed = old->c_ospeed;
+}
+EXPORT_SYMBOL(tty_termios_copy_hw);
+
+/**
+ *	tty_termios_hw_change	-	check for setting change
+ *	@a: termios
+ *	@b: termios to compare
+ *
+ *	Check if any of the bits that affect a dumb device have changed
+ *	between the two termios structures, or a speed change is needed.
+ */
+
+int tty_termios_hw_change(struct ktermios *a, struct ktermios *b)
+{
+	if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
+		return 1;
+	if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
+		return 1;
+	return 0;
+}
+EXPORT_SYMBOL(tty_termios_hw_change);
+
+/**
+ *	change_termios		-	update termios values
+ *	@tty: tty to update
+ *	@new_termios: desired new value
+ *
+ *	Perform updates to the termios values set on this terminal. There
+ *	is a bit of layering violation here with n_tty in terms of the
+ *	internal knowledge of this function.
+ *
+ *	Locking: termios_mutex
+ */
+
+static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
+{
+	struct ktermios old_termios;
+	struct tty_ldisc *ld;
+	unsigned long flags;
+
+	/*
+	 *	Perform the actual termios internal changes under lock.
+	 */
+
+
+	/* FIXME: we need to decide on some locking/ordering semantics
+	   for the set_termios notification eventually */
+	mutex_lock(&tty->termios_mutex);
+	old_termios = *tty->termios;
+	*tty->termios = *new_termios;
+	unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
+
+	/* See if packet mode change of state. */
+	if (tty->link && tty->link->packet) {
+		int extproc = (old_termios.c_lflag & EXTPROC) |
+				(tty->termios->c_lflag & EXTPROC);
+		int old_flow = ((old_termios.c_iflag & IXON) &&
+				(old_termios.c_cc[VSTOP] == '\023') &&
+				(old_termios.c_cc[VSTART] == '\021'));
+		int new_flow = (I_IXON(tty) &&
+				STOP_CHAR(tty) == '\023' &&
+				START_CHAR(tty) == '\021');
+		if ((old_flow != new_flow) || extproc) {
+			spin_lock_irqsave(&tty->ctrl_lock, flags);
+			if (old_flow != new_flow) {
+				tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
+				if (new_flow)
+					tty->ctrl_status |= TIOCPKT_DOSTOP;
+				else
+					tty->ctrl_status |= TIOCPKT_NOSTOP;
+			}
+			if (extproc)
+				tty->ctrl_status |= TIOCPKT_IOCTL;
+			spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+			wake_up_interruptible(&tty->link->read_wait);
+		}
+	}
+
+	if (tty->ops->set_termios)
+		(*tty->ops->set_termios)(tty, &old_termios);
+	else
+		tty_termios_copy_hw(tty->termios, &old_termios);
+
+	ld = tty_ldisc_ref(tty);
+	if (ld != NULL) {
+		if (ld->ops->set_termios)
+			(ld->ops->set_termios)(tty, &old_termios);
+		tty_ldisc_deref(ld);
+	}
+	mutex_unlock(&tty->termios_mutex);
+}
+
+/**
+ *	set_termios		-	set termios values for a tty
+ *	@tty: terminal device
+ *	@arg: user data
+ *	@opt: option information
+ *
+ *	Helper function to prepare termios data and run necessary other
+ *	functions before using change_termios to do the actual changes.
+ *
+ *	Locking:
+ *		Called functions take ldisc and termios_mutex locks
+ */
+
+static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
+{
+	struct ktermios tmp_termios;
+	struct tty_ldisc *ld;
+	int retval = tty_check_change(tty);
+
+	if (retval)
+		return retval;
+
+	mutex_lock(&tty->termios_mutex);
+	memcpy(&tmp_termios, tty->termios, sizeof(struct ktermios));
+	mutex_unlock(&tty->termios_mutex);
+
+	if (opt & TERMIOS_TERMIO) {
+		if (user_termio_to_kernel_termios(&tmp_termios,
+						(struct termio __user *)arg))
+			return -EFAULT;
+#ifdef TCGETS2
+	} else if (opt & TERMIOS_OLD) {
+		if (user_termios_to_kernel_termios_1(&tmp_termios,
+						(struct termios __user *)arg))
+			return -EFAULT;
+	} else {
+		if (user_termios_to_kernel_termios(&tmp_termios,
+						(struct termios2 __user *)arg))
+			return -EFAULT;
+	}
+#else
+	} else if (user_termios_to_kernel_termios(&tmp_termios,
+					(struct termios __user *)arg))
+		return -EFAULT;
+#endif
+
+	/* If old style Bfoo values are used then load c_ispeed/c_ospeed
+	 * with the real speed so its unconditionally usable */
+	tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
+	tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
+
+	ld = tty_ldisc_ref(tty);
+
+	if (ld != NULL) {
+		if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
+		tty_ldisc_deref(ld);
+	}
+
+	if (opt & TERMIOS_WAIT) {
+		tty_wait_until_sent(tty, 0);
+		if (signal_pending(current))
+			return -EINTR;
+	}
+
+	change_termios(tty, &tmp_termios);
+
+	/* FIXME: Arguably if tmp_termios == tty->termios AND the
+	   actual requested termios was not tmp_termios then we may
+	   want to return an error as no user requested change has
+	   succeeded */
+	return 0;
+}
+
+static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
+{
+	mutex_lock(&tty->termios_mutex);
+	memcpy(kterm, tty->termios, sizeof(struct ktermios));
+	mutex_unlock(&tty->termios_mutex);
+}
+
+static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
+{
+	mutex_lock(&tty->termios_mutex);
+	memcpy(kterm, tty->termios_locked, sizeof(struct ktermios));
+	mutex_unlock(&tty->termios_mutex);
+}
+
+static int get_termio(struct tty_struct *tty, struct termio __user *termio)
+{
+	struct ktermios kterm;
+	copy_termios(tty, &kterm);
+	if (kernel_termios_to_user_termio(termio, &kterm))
+		return -EFAULT;
+	return 0;
+}
+
+
+#ifdef TCGETX
+
+/**
+ *	set_termiox	-	set termiox fields if possible
+ *	@tty: terminal
+ *	@arg: termiox structure from user
+ *	@opt: option flags for ioctl type
+ *
+ *	Implement the device calling points for the SYS5 termiox ioctl
+ *	interface in Linux
+ */
+
+static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
+{
+	struct termiox tnew;
+	struct tty_ldisc *ld;
+
+	if (tty->termiox == NULL)
+		return -EINVAL;
+	if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
+		return -EFAULT;
+
+	ld = tty_ldisc_ref(tty);
+	if (ld != NULL) {
+		if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
+		tty_ldisc_deref(ld);
+	}
+	if (opt & TERMIOS_WAIT) {
+		tty_wait_until_sent(tty, 0);
+		if (signal_pending(current))
+			return -EINTR;
+	}
+
+	mutex_lock(&tty->termios_mutex);
+	if (tty->ops->set_termiox)
+		tty->ops->set_termiox(tty, &tnew);
+	mutex_unlock(&tty->termios_mutex);
+	return 0;
+}
+
+#endif
+
+
+#ifdef TIOCGETP
+/*
+ * These are deprecated, but there is limited support..
+ *
+ * The "sg_flags" translation is a joke..
+ */
+static int get_sgflags(struct tty_struct *tty)
+{
+	int flags = 0;
+
+	if (!(tty->termios->c_lflag & ICANON)) {
+		if (tty->termios->c_lflag & ISIG)
+			flags |= 0x02;		/* cbreak */
+		else
+			flags |= 0x20;		/* raw */
+	}
+	if (tty->termios->c_lflag & ECHO)
+		flags |= 0x08;			/* echo */
+	if (tty->termios->c_oflag & OPOST)
+		if (tty->termios->c_oflag & ONLCR)
+			flags |= 0x10;		/* crmod */
+	return flags;
+}
+
+static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
+{
+	struct sgttyb tmp;
+
+	mutex_lock(&tty->termios_mutex);
+	tmp.sg_ispeed = tty->termios->c_ispeed;
+	tmp.sg_ospeed = tty->termios->c_ospeed;
+	tmp.sg_erase = tty->termios->c_cc[VERASE];
+	tmp.sg_kill = tty->termios->c_cc[VKILL];
+	tmp.sg_flags = get_sgflags(tty);
+	mutex_unlock(&tty->termios_mutex);
+
+	return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
+}
+
+static void set_sgflags(struct ktermios *termios, int flags)
+{
+	termios->c_iflag = ICRNL | IXON;
+	termios->c_oflag = 0;
+	termios->c_lflag = ISIG | ICANON;
+	if (flags & 0x02) {	/* cbreak */
+		termios->c_iflag = 0;
+		termios->c_lflag &= ~ICANON;
+	}
+	if (flags & 0x08) {		/* echo */
+		termios->c_lflag |= ECHO | ECHOE | ECHOK |
+				    ECHOCTL | ECHOKE | IEXTEN;
+	}
+	if (flags & 0x10) {		/* crmod */
+		termios->c_oflag |= OPOST | ONLCR;
+	}
+	if (flags & 0x20) {	/* raw */
+		termios->c_iflag = 0;
+		termios->c_lflag &= ~(ISIG | ICANON);
+	}
+	if (!(termios->c_lflag & ICANON)) {
+		termios->c_cc[VMIN] = 1;
+		termios->c_cc[VTIME] = 0;
+	}
+}
+
+/**
+ *	set_sgttyb		-	set legacy terminal values
+ *	@tty: tty structure
+ *	@sgttyb: pointer to old style terminal structure
+ *
+ *	Updates a terminal from the legacy BSD style terminal information
+ *	structure.
+ *
+ *	Locking: termios_mutex
+ */
+
+static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
+{
+	int retval;
+	struct sgttyb tmp;
+	struct ktermios termios;
+
+	retval = tty_check_change(tty);
+	if (retval)
+		return retval;
+
+	if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
+		return -EFAULT;
+
+	mutex_lock(&tty->termios_mutex);
+	termios = *tty->termios;
+	termios.c_cc[VERASE] = tmp.sg_erase;
+	termios.c_cc[VKILL] = tmp.sg_kill;
+	set_sgflags(&termios, tmp.sg_flags);
+	/* Try and encode into Bfoo format */
+#ifdef BOTHER
+	tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
+						termios.c_ospeed);
+#endif
+	mutex_unlock(&tty->termios_mutex);
+	change_termios(tty, &termios);
+	return 0;
+}
+#endif
+
+#ifdef TIOCGETC
+static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
+{
+	struct tchars tmp;
+
+	mutex_lock(&tty->termios_mutex);
+	tmp.t_intrc = tty->termios->c_cc[VINTR];
+	tmp.t_quitc = tty->termios->c_cc[VQUIT];
+	tmp.t_startc = tty->termios->c_cc[VSTART];
+	tmp.t_stopc = tty->termios->c_cc[VSTOP];
+	tmp.t_eofc = tty->termios->c_cc[VEOF];
+	tmp.t_brkc = tty->termios->c_cc[VEOL2];	/* what is brkc anyway? */
+	mutex_unlock(&tty->termios_mutex);
+	return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
+}
+
+static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
+{
+	struct tchars tmp;
+
+	if (copy_from_user(&tmp, tchars, sizeof(tmp)))
+		return -EFAULT;
+	mutex_lock(&tty->termios_mutex);
+	tty->termios->c_cc[VINTR] = tmp.t_intrc;
+	tty->termios->c_cc[VQUIT] = tmp.t_quitc;
+	tty->termios->c_cc[VSTART] = tmp.t_startc;
+	tty->termios->c_cc[VSTOP] = tmp.t_stopc;
+	tty->termios->c_cc[VEOF] = tmp.t_eofc;
+	tty->termios->c_cc[VEOL2] = tmp.t_brkc;	/* what is brkc anyway? */
+	mutex_unlock(&tty->termios_mutex);
+	return 0;
+}
+#endif
+
+#ifdef TIOCGLTC
+static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
+{
+	struct ltchars tmp;
+
+	mutex_lock(&tty->termios_mutex);
+	tmp.t_suspc = tty->termios->c_cc[VSUSP];
+	/* what is dsuspc anyway? */
+	tmp.t_dsuspc = tty->termios->c_cc[VSUSP];
+	tmp.t_rprntc = tty->termios->c_cc[VREPRINT];
+	/* what is flushc anyway? */
+	tmp.t_flushc = tty->termios->c_cc[VEOL2];
+	tmp.t_werasc = tty->termios->c_cc[VWERASE];
+	tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
+	mutex_unlock(&tty->termios_mutex);
+	return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
+}
+
+static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
+{
+	struct ltchars tmp;
+
+	if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
+		return -EFAULT;
+
+	mutex_lock(&tty->termios_mutex);
+	tty->termios->c_cc[VSUSP] = tmp.t_suspc;
+	/* what is dsuspc anyway? */
+	tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;
+	tty->termios->c_cc[VREPRINT] = tmp.t_rprntc;
+	/* what is flushc anyway? */
+	tty->termios->c_cc[VEOL2] = tmp.t_flushc;
+	tty->termios->c_cc[VWERASE] = tmp.t_werasc;
+	tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
+	mutex_unlock(&tty->termios_mutex);
+	return 0;
+}
+#endif
+
+/**
+ *	send_prio_char		-	send priority character
+ *
+ *	Send a high priority character to the tty even if stopped
+ *
+ *	Locking: none for xchar method, write ordering for write method.
+ */
+
+static int send_prio_char(struct tty_struct *tty, char ch)
+{
+	int	was_stopped = tty->stopped;
+
+	if (tty->ops->send_xchar) {
+		tty->ops->send_xchar(tty, ch);
+		return 0;
+	}
+
+	if (tty_write_lock(tty, 0) < 0)
+		return -ERESTARTSYS;
+
+	if (was_stopped)
+		start_tty(tty);
+	tty->ops->write(tty, &ch, 1);
+	if (was_stopped)
+		stop_tty(tty);
+	tty_write_unlock(tty);
+	return 0;
+}
+
+/**
+ *	tty_change_softcar	-	carrier change ioctl helper
+ *	@tty: tty to update
+ *	@arg: enable/disable CLOCAL
+ *
+ *	Perform a change to the CLOCAL state and call into the driver
+ *	layer to make it visible. All done with the termios mutex
+ */
+
+static int tty_change_softcar(struct tty_struct *tty, int arg)
+{
+	int ret = 0;
+	int bit = arg ? CLOCAL : 0;
+	struct ktermios old;
+
+	mutex_lock(&tty->termios_mutex);
+	old = *tty->termios;
+	tty->termios->c_cflag &= ~CLOCAL;
+	tty->termios->c_cflag |= bit;
+	if (tty->ops->set_termios)
+		tty->ops->set_termios(tty, &old);
+	if ((tty->termios->c_cflag & CLOCAL) != bit)
+		ret = -EINVAL;
+	mutex_unlock(&tty->termios_mutex);
+	return ret;
+}
+
+/**
+ *	tty_mode_ioctl		-	mode related ioctls
+ *	@tty: tty for the ioctl
+ *	@file: file pointer for the tty
+ *	@cmd: command
+ *	@arg: ioctl argument
+ *
+ *	Perform non line discipline specific mode control ioctls. This
+ *	is designed to be called by line disciplines to ensure they provide
+ *	consistent mode setting.
+ */
+
+int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
+			unsigned int cmd, unsigned long arg)
+{
+	struct tty_struct *real_tty;
+	void __user *p = (void __user *)arg;
+	int ret = 0;
+	struct ktermios kterm;
+
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+		real_tty = tty->link;
+	else
+		real_tty = tty;
+
+	switch (cmd) {
+#ifdef TIOCGETP
+	case TIOCGETP:
+		return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
+	case TIOCSETP:
+	case TIOCSETN:
+		return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
+#endif
+#ifdef TIOCGETC
+	case TIOCGETC:
+		return get_tchars(real_tty, p);
+	case TIOCSETC:
+		return set_tchars(real_tty, p);
+#endif
+#ifdef TIOCGLTC
+	case TIOCGLTC:
+		return get_ltchars(real_tty, p);
+	case TIOCSLTC:
+		return set_ltchars(real_tty, p);
+#endif
+	case TCSETSF:
+		return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
+	case TCSETSW:
+		return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
+	case TCSETS:
+		return set_termios(real_tty, p, TERMIOS_OLD);
+#ifndef TCGETS2
+	case TCGETS:
+		copy_termios(real_tty, &kterm);
+		if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
+			ret = -EFAULT;
+		return ret;
+#else
+	case TCGETS:
+		copy_termios(real_tty, &kterm);
+		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
+			ret = -EFAULT;
+		return ret;
+	case TCGETS2:
+		copy_termios(real_tty, &kterm);
+		if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
+			ret = -EFAULT;
+		return ret;
+	case TCSETSF2:
+		return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
+	case TCSETSW2:
+		return set_termios(real_tty, p, TERMIOS_WAIT);
+	case TCSETS2:
+		return set_termios(real_tty, p, 0);
+#endif
+	case TCGETA:
+		return get_termio(real_tty, p);
+	case TCSETAF:
+		return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
+	case TCSETAW:
+		return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
+	case TCSETA:
+		return set_termios(real_tty, p, TERMIOS_TERMIO);
+#ifndef TCGETS2
+	case TIOCGLCKTRMIOS:
+		copy_termios_locked(real_tty, &kterm);
+		if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
+			ret = -EFAULT;
+		return ret;
+	case TIOCSLCKTRMIOS:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		copy_termios_locked(real_tty, &kterm);
+		if (user_termios_to_kernel_termios(&kterm,
+					       (struct termios __user *) arg))
+			return -EFAULT;
+		mutex_lock(&real_tty->termios_mutex);
+		memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
+		mutex_unlock(&real_tty->termios_mutex);
+		return 0;
+#else
+	case TIOCGLCKTRMIOS:
+		copy_termios_locked(real_tty, &kterm);
+		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
+			ret = -EFAULT;
+		return ret;
+	case TIOCSLCKTRMIOS:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		copy_termios_locked(real_tty, &kterm);
+		if (user_termios_to_kernel_termios_1(&kterm,
+					       (struct termios __user *) arg))
+			return -EFAULT;
+		mutex_lock(&real_tty->termios_mutex);
+		memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
+		mutex_unlock(&real_tty->termios_mutex);
+		return ret;
+#endif
+#ifdef TCGETX
+	case TCGETX: {
+		struct termiox ktermx;
+		if (real_tty->termiox == NULL)
+			return -EINVAL;
+		mutex_lock(&real_tty->termios_mutex);
+		memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
+		mutex_unlock(&real_tty->termios_mutex);
+		if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
+			ret = -EFAULT;
+		return ret;
+	}
+	case TCSETX:
+		return set_termiox(real_tty, p, 0);
+	case TCSETXW:
+		return set_termiox(real_tty, p, TERMIOS_WAIT);
+	case TCSETXF:
+		return set_termiox(real_tty, p, TERMIOS_FLUSH);
+#endif		
+	case TIOCGSOFTCAR:
+		copy_termios(real_tty, &kterm);
+		ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
+						(int __user *)arg);
+		return ret;
+	case TIOCSSOFTCAR:
+		if (get_user(arg, (unsigned int __user *) arg))
+			return -EFAULT;
+		return tty_change_softcar(real_tty, arg);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+EXPORT_SYMBOL_GPL(tty_mode_ioctl);
+
+int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
+{
+	struct tty_ldisc *ld;
+	int retval = tty_check_change(tty);
+	if (retval)
+		return retval;
+
+	ld = tty_ldisc_ref_wait(tty);
+	switch (arg) {
+	case TCIFLUSH:
+		if (ld && ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
+		break;
+	case TCIOFLUSH:
+		if (ld && ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
+		/* fall through */
+	case TCOFLUSH:
+		tty_driver_flush_buffer(tty);
+		break;
+	default:
+		tty_ldisc_deref(ld);
+		return -EINVAL;
+	}
+	tty_ldisc_deref(ld);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tty_perform_flush);
+
+int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
+		       unsigned int cmd, unsigned long arg)
+{
+	unsigned long flags;
+	int retval;
+
+	switch (cmd) {
+	case TCXONC:
+		retval = tty_check_change(tty);
+		if (retval)
+			return retval;
+		switch (arg) {
+		case TCOOFF:
+			if (!tty->flow_stopped) {
+				tty->flow_stopped = 1;
+				stop_tty(tty);
+			}
+			break;
+		case TCOON:
+			if (tty->flow_stopped) {
+				tty->flow_stopped = 0;
+				start_tty(tty);
+			}
+			break;
+		case TCIOFF:
+			if (STOP_CHAR(tty) != __DISABLED_CHAR)
+				return send_prio_char(tty, STOP_CHAR(tty));
+			break;
+		case TCION:
+			if (START_CHAR(tty) != __DISABLED_CHAR)
+				return send_prio_char(tty, START_CHAR(tty));
+			break;
+		default:
+			return -EINVAL;
+		}
+		return 0;
+	case TCFLSH:
+		return tty_perform_flush(tty, arg);
+	case TIOCPKT:
+	{
+		int pktmode;
+
+		if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
+		    tty->driver->subtype != PTY_TYPE_MASTER)
+			return -ENOTTY;
+		if (get_user(pktmode, (int __user *) arg))
+			return -EFAULT;
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
+		if (pktmode) {
+			if (!tty->packet) {
+				tty->packet = 1;
+				tty->link->ctrl_status = 0;
+			}
+		} else
+			tty->packet = 0;
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+		return 0;
+	}
+	default:
+		/* Try the mode commands */
+		return tty_mode_ioctl(tty, file, cmd, arg);
+	}
+}
+EXPORT_SYMBOL(n_tty_ioctl_helper);
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
new file mode 100644
index 0000000..d8e96b0
--- /dev/null
+++ b/drivers/tty/tty_ldisc.c
@@ -0,0 +1,950 @@
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/devpts_fs.h>
+#include <linux/file.h>
+#include <linux/console.h>
+#include <linux/timer.h>
+#include <linux/ctype.h>
+#include <linux/kd.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/seq_file.h>
+
+#include <linux/uaccess.h>
+#include <asm/system.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+
+#include <linux/smp_lock.h>	/* For the moment */
+
+#include <linux/kmod.h>
+#include <linux/nsproxy.h>
+
+/*
+ *	This guards the refcounted line discipline lists. The lock
+ *	must be taken with irqs off because there are hangup path
+ *	callers who will do ldisc lookups and cannot sleep.
+ */
+
+static DEFINE_SPINLOCK(tty_ldisc_lock);
+static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
+static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_idle);
+/* Line disc dispatch table */
+static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
+
+static inline struct tty_ldisc *get_ldisc(struct tty_ldisc *ld)
+{
+	if (ld)
+		atomic_inc(&ld->users);
+	return ld;
+}
+
+static void put_ldisc(struct tty_ldisc *ld)
+{
+	unsigned long flags;
+
+	if (WARN_ON_ONCE(!ld))
+		return;
+
+	/*
+	 * If this is the last user, free the ldisc, and
+	 * release the ldisc ops.
+	 *
+	 * We really want an "atomic_dec_and_lock_irqsave()",
+	 * but we don't have it, so this does it by hand.
+	 */
+	local_irq_save(flags);
+	if (atomic_dec_and_lock(&ld->users, &tty_ldisc_lock)) {
+		struct tty_ldisc_ops *ldo = ld->ops;
+
+		ldo->refcount--;
+		module_put(ldo->owner);
+		spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+		kfree(ld);
+		return;
+	}
+	local_irq_restore(flags);
+	wake_up(&tty_ldisc_idle);
+}
+
+/**
+ *	tty_register_ldisc	-	install a line discipline
+ *	@disc: ldisc number
+ *	@new_ldisc: pointer to the ldisc object
+ *
+ *	Installs a new line discipline into the kernel. The discipline
+ *	is set up as unreferenced and then made available to the kernel
+ *	from this point onwards.
+ *
+ *	Locking:
+ *		takes tty_ldisc_lock to guard against ldisc races
+ */
+
+int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (disc < N_TTY || disc >= NR_LDISCS)
+		return -EINVAL;
+
+	spin_lock_irqsave(&tty_ldisc_lock, flags);
+	tty_ldiscs[disc] = new_ldisc;
+	new_ldisc->num = disc;
+	new_ldisc->refcount = 0;
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(tty_register_ldisc);
+
+/**
+ *	tty_unregister_ldisc	-	unload a line discipline
+ *	@disc: ldisc number
+ *	@new_ldisc: pointer to the ldisc object
+ *
+ *	Remove a line discipline from the kernel providing it is not
+ *	currently in use.
+ *
+ *	Locking:
+ *		takes tty_ldisc_lock to guard against ldisc races
+ */
+
+int tty_unregister_ldisc(int disc)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (disc < N_TTY || disc >= NR_LDISCS)
+		return -EINVAL;
+
+	spin_lock_irqsave(&tty_ldisc_lock, flags);
+	if (tty_ldiscs[disc]->refcount)
+		ret = -EBUSY;
+	else
+		tty_ldiscs[disc] = NULL;
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(tty_unregister_ldisc);
+
+static struct tty_ldisc_ops *get_ldops(int disc)
+{
+	unsigned long flags;
+	struct tty_ldisc_ops *ldops, *ret;
+
+	spin_lock_irqsave(&tty_ldisc_lock, flags);
+	ret = ERR_PTR(-EINVAL);
+	ldops = tty_ldiscs[disc];
+	if (ldops) {
+		ret = ERR_PTR(-EAGAIN);
+		if (try_module_get(ldops->owner)) {
+			ldops->refcount++;
+			ret = ldops;
+		}
+	}
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+	return ret;
+}
+
+static void put_ldops(struct tty_ldisc_ops *ldops)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tty_ldisc_lock, flags);
+	ldops->refcount--;
+	module_put(ldops->owner);
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+}
+
+/**
+ *	tty_ldisc_get		-	take a reference to an ldisc
+ *	@disc: ldisc number
+ *
+ *	Takes a reference to a line discipline. Deals with refcounts and
+ *	module locking counts. Returns NULL if the discipline is not available.
+ *	Returns a pointer to the discipline and bumps the ref count if it is
+ *	available
+ *
+ *	Locking:
+ *		takes tty_ldisc_lock to guard against ldisc races
+ */
+
+static struct tty_ldisc *tty_ldisc_get(int disc)
+{
+	struct tty_ldisc *ld;
+	struct tty_ldisc_ops *ldops;
+
+	if (disc < N_TTY || disc >= NR_LDISCS)
+		return ERR_PTR(-EINVAL);
+
+	/*
+	 * Get the ldisc ops - we may need to request them to be loaded
+	 * dynamically and try again.
+	 */
+	ldops = get_ldops(disc);
+	if (IS_ERR(ldops)) {
+		request_module("tty-ldisc-%d", disc);
+		ldops = get_ldops(disc);
+		if (IS_ERR(ldops))
+			return ERR_CAST(ldops);
+	}
+
+	ld = kmalloc(sizeof(struct tty_ldisc), GFP_KERNEL);
+	if (ld == NULL) {
+		put_ldops(ldops);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ld->ops = ldops;
+	atomic_set(&ld->users, 1);
+	return ld;
+}
+
+static void *tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
+{
+	return (*pos < NR_LDISCS) ? pos : NULL;
+}
+
+static void *tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	(*pos)++;
+	return (*pos < NR_LDISCS) ? pos : NULL;
+}
+
+static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
+{
+}
+
+static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
+{
+	int i = *(loff_t *)v;
+	struct tty_ldisc_ops *ldops;
+
+	ldops = get_ldops(i);
+	if (IS_ERR(ldops))
+		return 0;
+	seq_printf(m, "%-10s %2d\n", ldops->name ? ldops->name : "???", i);
+	put_ldops(ldops);
+	return 0;
+}
+
+static const struct seq_operations tty_ldiscs_seq_ops = {
+	.start	= tty_ldiscs_seq_start,
+	.next	= tty_ldiscs_seq_next,
+	.stop	= tty_ldiscs_seq_stop,
+	.show	= tty_ldiscs_seq_show,
+};
+
+static int proc_tty_ldiscs_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &tty_ldiscs_seq_ops);
+}
+
+const struct file_operations tty_ldiscs_proc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= proc_tty_ldiscs_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+/**
+ *	tty_ldisc_assign	-	set ldisc on a tty
+ *	@tty: tty to assign
+ *	@ld: line discipline
+ *
+ *	Install an instance of a line discipline into a tty structure. The
+ *	ldisc must have a reference count above zero to ensure it remains.
+ *	The tty instance refcount starts at zero.
+ *
+ *	Locking:
+ *		Caller must hold references
+ */
+
+static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+	tty->ldisc = ld;
+}
+
+/**
+ *	tty_ldisc_try		-	internal helper
+ *	@tty: the tty
+ *
+ *	Make a single attempt to grab and bump the refcount on
+ *	the tty ldisc. Return 0 on failure or 1 on success. This is
+ *	used to implement both the waiting and non waiting versions
+ *	of tty_ldisc_ref
+ *
+ *	Locking: takes tty_ldisc_lock
+ */
+
+static struct tty_ldisc *tty_ldisc_try(struct tty_struct *tty)
+{
+	unsigned long flags;
+	struct tty_ldisc *ld;
+
+	spin_lock_irqsave(&tty_ldisc_lock, flags);
+	ld = NULL;
+	if (test_bit(TTY_LDISC, &tty->flags))
+		ld = get_ldisc(tty->ldisc);
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+	return ld;
+}
+
+/**
+ *	tty_ldisc_ref_wait	-	wait for the tty ldisc
+ *	@tty: tty device
+ *
+ *	Dereference the line discipline for the terminal and take a
+ *	reference to it. If the line discipline is in flux then
+ *	wait patiently until it changes.
+ *
+ *	Note: Must not be called from an IRQ/timer context. The caller
+ *	must also be careful not to hold other locks that will deadlock
+ *	against a discipline change, such as an existing ldisc reference
+ *	(which we check for)
+ *
+ *	Locking: call functions take tty_ldisc_lock
+ */
+
+struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld;
+
+	/* wait_event is a macro */
+	wait_event(tty_ldisc_wait, (ld = tty_ldisc_try(tty)) != NULL);
+	return ld;
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
+
+/**
+ *	tty_ldisc_ref		-	get the tty ldisc
+ *	@tty: tty device
+ *
+ *	Dereference the line discipline for the terminal and take a
+ *	reference to it. If the line discipline is in flux then
+ *	return NULL. Can be called from IRQ and timer functions.
+ *
+ *	Locking: called functions take tty_ldisc_lock
+ */
+
+struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
+{
+	return tty_ldisc_try(tty);
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_ref);
+
+/**
+ *	tty_ldisc_deref		-	free a tty ldisc reference
+ *	@ld: reference to free up
+ *
+ *	Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May
+ *	be called in IRQ context.
+ *
+ *	Locking: takes tty_ldisc_lock
+ */
+
+void tty_ldisc_deref(struct tty_ldisc *ld)
+{
+	put_ldisc(ld);
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_deref);
+
+static inline void tty_ldisc_put(struct tty_ldisc *ld)
+{
+	put_ldisc(ld);
+}
+
+/**
+ *	tty_ldisc_enable	-	allow ldisc use
+ *	@tty: terminal to activate ldisc on
+ *
+ *	Set the TTY_LDISC flag when the line discipline can be called
+ *	again. Do necessary wakeups for existing sleepers. Clear the LDISC
+ *	changing flag to indicate any ldisc change is now over.
+ *
+ *	Note: nobody should set the TTY_LDISC bit except via this function.
+ *	Clearing directly is allowed.
+ */
+
+void tty_ldisc_enable(struct tty_struct *tty)
+{
+	set_bit(TTY_LDISC, &tty->flags);
+	clear_bit(TTY_LDISC_CHANGING, &tty->flags);
+	wake_up(&tty_ldisc_wait);
+}
+
+/**
+ *	tty_ldisc_flush	-	flush line discipline queue
+ *	@tty: tty
+ *
+ *	Flush the line discipline queue (if any) for this tty. If there
+ *	is no line discipline active this is a no-op.
+ */
+
+void tty_ldisc_flush(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld = tty_ldisc_ref(tty);
+	if (ld) {
+		if (ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
+		tty_ldisc_deref(ld);
+	}
+	tty_buffer_flush(tty);
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_flush);
+
+/**
+ *	tty_set_termios_ldisc		-	set ldisc field
+ *	@tty: tty structure
+ *	@num: line discipline number
+ *
+ *	This is probably overkill for real world processors but
+ *	they are not on hot paths so a little discipline won't do
+ *	any harm.
+ *
+ *	Locking: takes termios_mutex
+ */
+
+static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
+{
+	mutex_lock(&tty->termios_mutex);
+	tty->termios->c_line = num;
+	mutex_unlock(&tty->termios_mutex);
+}
+
+/**
+ *	tty_ldisc_open		-	open a line discipline
+ *	@tty: tty we are opening the ldisc on
+ *	@ld: discipline to open
+ *
+ *	A helper opening method. Also a convenient debugging and check
+ *	point.
+ *
+ *	Locking: always called with BTM already held.
+ */
+
+static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+	WARN_ON(test_and_set_bit(TTY_LDISC_OPEN, &tty->flags));
+	if (ld->ops->open) {
+		int ret;
+                /* BTM here locks versus a hangup event */
+		WARN_ON(!tty_locked());
+		ret = ld->ops->open(tty);
+		return ret;
+	}
+	return 0;
+}
+
+/**
+ *	tty_ldisc_close		-	close a line discipline
+ *	@tty: tty we are opening the ldisc on
+ *	@ld: discipline to close
+ *
+ *	A helper close method. Also a convenient debugging and check
+ *	point.
+ */
+
+static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+	WARN_ON(!test_bit(TTY_LDISC_OPEN, &tty->flags));
+	clear_bit(TTY_LDISC_OPEN, &tty->flags);
+	if (ld->ops->close)
+		ld->ops->close(tty);
+}
+
+/**
+ *	tty_ldisc_restore	-	helper for tty ldisc change
+ *	@tty: tty to recover
+ *	@old: previous ldisc
+ *
+ *	Restore the previous line discipline or N_TTY when a line discipline
+ *	change fails due to an open error
+ */
+
+static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
+{
+	char buf[64];
+	struct tty_ldisc *new_ldisc;
+	int r;
+
+	/* There is an outstanding reference here so this is safe */
+	old = tty_ldisc_get(old->ops->num);
+	WARN_ON(IS_ERR(old));
+	tty_ldisc_assign(tty, old);
+	tty_set_termios_ldisc(tty, old->ops->num);
+	if (tty_ldisc_open(tty, old) < 0) {
+		tty_ldisc_put(old);
+		/* This driver is always present */
+		new_ldisc = tty_ldisc_get(N_TTY);
+		if (IS_ERR(new_ldisc))
+			panic("n_tty: get");
+		tty_ldisc_assign(tty, new_ldisc);
+		tty_set_termios_ldisc(tty, N_TTY);
+		r = tty_ldisc_open(tty, new_ldisc);
+		if (r < 0)
+			panic("Couldn't open N_TTY ldisc for "
+			      "%s --- error %d.",
+			      tty_name(tty, buf), r);
+	}
+}
+
+/**
+ *	tty_ldisc_halt		-	shut down the line discipline
+ *	@tty: tty device
+ *
+ *	Shut down the line discipline and work queue for this tty device.
+ *	The TTY_LDISC flag being cleared ensures no further references can
+ *	be obtained while the delayed work queue halt ensures that no more
+ *	data is fed to the ldisc.
+ *
+ *	You need to do a 'flush_scheduled_work()' (outside the ldisc_mutex)
+ *	in order to make sure any currently executing ldisc work is also
+ *	flushed.
+ */
+
+static int tty_ldisc_halt(struct tty_struct *tty)
+{
+	clear_bit(TTY_LDISC, &tty->flags);
+	return cancel_delayed_work_sync(&tty->buf.work);
+}
+
+/**
+ *	tty_ldisc_wait_idle	-	wait for the ldisc to become idle
+ *	@tty: tty to wait for
+ *
+ *	Wait for the line discipline to become idle. The discipline must
+ *	have been halted for this to guarantee it remains idle.
+ */
+static int tty_ldisc_wait_idle(struct tty_struct *tty)
+{
+	int ret;
+	ret = wait_event_interruptible_timeout(tty_ldisc_idle,
+			atomic_read(&tty->ldisc->users) == 1, 5 * HZ);
+	if (ret < 0)
+		return ret;
+	return ret > 0 ? 0 : -EBUSY;
+}
+
+/**
+ *	tty_set_ldisc		-	set line discipline
+ *	@tty: the terminal to set
+ *	@ldisc: the line discipline
+ *
+ *	Set the discipline of a tty line. Must be called from a process
+ *	context. The ldisc change logic has to protect itself against any
+ *	overlapping ldisc change (including on the other end of pty pairs),
+ *	the close of one side of a tty/pty pair, and eventually hangup.
+ *
+ *	Locking: takes tty_ldisc_lock, termios_mutex
+ */
+
+int tty_set_ldisc(struct tty_struct *tty, int ldisc)
+{
+	int retval;
+	struct tty_ldisc *o_ldisc, *new_ldisc;
+	int work, o_work = 0;
+	struct tty_struct *o_tty;
+
+	new_ldisc = tty_ldisc_get(ldisc);
+	if (IS_ERR(new_ldisc))
+		return PTR_ERR(new_ldisc);
+
+	tty_lock();
+	/*
+	 *	We need to look at the tty locking here for pty/tty pairs
+	 *	when both sides try to change in parallel.
+	 */
+
+	o_tty = tty->link;	/* o_tty is the pty side or NULL */
+
+
+	/*
+	 *	Check the no-op case
+	 */
+
+	if (tty->ldisc->ops->num == ldisc) {
+		tty_unlock();
+		tty_ldisc_put(new_ldisc);
+		return 0;
+	}
+
+	tty_unlock();
+	/*
+	 *	Problem: What do we do if this blocks ?
+	 *	We could deadlock here
+	 */
+
+	tty_wait_until_sent(tty, 0);
+
+	tty_lock();
+	mutex_lock(&tty->ldisc_mutex);
+
+	/*
+	 *	We could be midstream of another ldisc change which has
+	 *	dropped the lock during processing. If so we need to wait.
+	 */
+
+	while (test_bit(TTY_LDISC_CHANGING, &tty->flags)) {
+		mutex_unlock(&tty->ldisc_mutex);
+		tty_unlock();
+		wait_event(tty_ldisc_wait,
+			test_bit(TTY_LDISC_CHANGING, &tty->flags) == 0);
+		tty_lock();
+		mutex_lock(&tty->ldisc_mutex);
+	}
+
+	set_bit(TTY_LDISC_CHANGING, &tty->flags);
+
+	/*
+	 *	No more input please, we are switching. The new ldisc
+	 *	will update this value in the ldisc open function
+	 */
+
+	tty->receive_room = 0;
+
+	o_ldisc = tty->ldisc;
+
+	tty_unlock();
+	/*
+	 *	Make sure we don't change while someone holds a
+	 *	reference to the line discipline. The TTY_LDISC bit
+	 *	prevents anyone taking a reference once it is clear.
+	 *	We need the lock to avoid racing reference takers.
+	 *
+	 *	We must clear the TTY_LDISC bit here to avoid a livelock
+	 *	with a userspace app continually trying to use the tty in
+	 *	parallel to the change and re-referencing the tty.
+	 */
+
+	work = tty_ldisc_halt(tty);
+	if (o_tty)
+		o_work = tty_ldisc_halt(o_tty);
+
+	/*
+	 * Wait for ->hangup_work and ->buf.work handlers to terminate.
+	 * We must drop the mutex here in case a hangup is also in process.
+	 */
+
+	mutex_unlock(&tty->ldisc_mutex);
+
+	flush_scheduled_work();
+
+	retval = tty_ldisc_wait_idle(tty);
+
+	tty_lock();
+	mutex_lock(&tty->ldisc_mutex);
+
+	/* handle wait idle failure locked */
+	if (retval) {
+		tty_ldisc_put(new_ldisc);
+		goto enable;
+	}
+
+	if (test_bit(TTY_HUPPED, &tty->flags)) {
+		/* We were raced by the hangup method. It will have stomped
+		   the ldisc data and closed the ldisc down */
+		clear_bit(TTY_LDISC_CHANGING, &tty->flags);
+		mutex_unlock(&tty->ldisc_mutex);
+		tty_ldisc_put(new_ldisc);
+		tty_unlock();
+		return -EIO;
+	}
+
+	/* Shutdown the current discipline. */
+	tty_ldisc_close(tty, o_ldisc);
+
+	/* Now set up the new line discipline. */
+	tty_ldisc_assign(tty, new_ldisc);
+	tty_set_termios_ldisc(tty, ldisc);
+
+	retval = tty_ldisc_open(tty, new_ldisc);
+	if (retval < 0) {
+		/* Back to the old one or N_TTY if we can't */
+		tty_ldisc_put(new_ldisc);
+		tty_ldisc_restore(tty, o_ldisc);
+	}
+
+	/* At this point we hold a reference to the new ldisc and a
+	   a reference to the old ldisc. If we ended up flipping back
+	   to the existing ldisc we have two references to it */
+
+	if (tty->ldisc->ops->num != o_ldisc->ops->num && tty->ops->set_ldisc)
+		tty->ops->set_ldisc(tty);
+
+	tty_ldisc_put(o_ldisc);
+
+enable:
+	/*
+	 *	Allow ldisc referencing to occur again
+	 */
+
+	tty_ldisc_enable(tty);
+	if (o_tty)
+		tty_ldisc_enable(o_tty);
+
+	/* Restart the work queue in case no characters kick it off. Safe if
+	   already running */
+	if (work)
+		schedule_delayed_work(&tty->buf.work, 1);
+	if (o_work)
+		schedule_delayed_work(&o_tty->buf.work, 1);
+	mutex_unlock(&tty->ldisc_mutex);
+	tty_unlock();
+	return retval;
+}
+
+/**
+ *	tty_reset_termios	-	reset terminal state
+ *	@tty: tty to reset
+ *
+ *	Restore a terminal to the driver default state.
+ */
+
+static void tty_reset_termios(struct tty_struct *tty)
+{
+	mutex_lock(&tty->termios_mutex);
+	*tty->termios = tty->driver->init_termios;
+	tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
+	tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
+	mutex_unlock(&tty->termios_mutex);
+}
+
+
+/**
+ *	tty_ldisc_reinit	-	reinitialise the tty ldisc
+ *	@tty: tty to reinit
+ *	@ldisc: line discipline to reinitialize
+ *
+ *	Switch the tty to a line discipline and leave the ldisc
+ *	state closed
+ */
+
+static int tty_ldisc_reinit(struct tty_struct *tty, int ldisc)
+{
+	struct tty_ldisc *ld = tty_ldisc_get(ldisc);
+
+	if (IS_ERR(ld))
+		return -1;
+
+	tty_ldisc_close(tty, tty->ldisc);
+	tty_ldisc_put(tty->ldisc);
+	tty->ldisc = NULL;
+	/*
+	 *	Switch the line discipline back
+	 */
+	tty_ldisc_assign(tty, ld);
+	tty_set_termios_ldisc(tty, ldisc);
+
+	return 0;
+}
+
+/**
+ *	tty_ldisc_hangup		-	hangup ldisc reset
+ *	@tty: tty being hung up
+ *
+ *	Some tty devices reset their termios when they receive a hangup
+ *	event. In that situation we must also switch back to N_TTY properly
+ *	before we reset the termios data.
+ *
+ *	Locking: We can take the ldisc mutex as the rest of the code is
+ *	careful to allow for this.
+ *
+ *	In the pty pair case this occurs in the close() path of the
+ *	tty itself so we must be careful about locking rules.
+ */
+
+void tty_ldisc_hangup(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld;
+	int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
+	int err = 0;
+
+	/*
+	 * FIXME! What are the locking issues here? This may me overdoing
+	 * things... This question is especially important now that we've
+	 * removed the irqlock.
+	 */
+	ld = tty_ldisc_ref(tty);
+	if (ld != NULL) {
+		/* We may have no line discipline at this point */
+		if (ld->ops->flush_buffer)
+			ld->ops->flush_buffer(tty);
+		tty_driver_flush_buffer(tty);
+		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
+		    ld->ops->write_wakeup)
+			ld->ops->write_wakeup(tty);
+		if (ld->ops->hangup)
+			ld->ops->hangup(tty);
+		tty_ldisc_deref(ld);
+	}
+	/*
+	 * FIXME: Once we trust the LDISC code better we can wait here for
+	 * ldisc completion and fix the driver call race
+	 */
+	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
+	wake_up_interruptible_poll(&tty->read_wait, POLLIN);
+	/*
+	 * Shutdown the current line discipline, and reset it to
+	 * N_TTY if need be.
+	 *
+	 * Avoid racing set_ldisc or tty_ldisc_release
+	 */
+	mutex_lock(&tty->ldisc_mutex);
+
+	/*
+	 * this is like tty_ldisc_halt, but we need to give up
+	 * the BTM before calling cancel_delayed_work_sync,
+	 * which may need to wait for another function taking the BTM
+	 */
+	clear_bit(TTY_LDISC, &tty->flags);
+	tty_unlock();
+	cancel_delayed_work_sync(&tty->buf.work);
+	mutex_unlock(&tty->ldisc_mutex);
+
+	tty_lock();
+	mutex_lock(&tty->ldisc_mutex);
+
+	/* At this point we have a closed ldisc and we want to
+	   reopen it. We could defer this to the next open but
+	   it means auditing a lot of other paths so this is
+	   a FIXME */
+	if (tty->ldisc) {	/* Not yet closed */
+		if (reset == 0) {
+
+			if (!tty_ldisc_reinit(tty, tty->termios->c_line))
+				err = tty_ldisc_open(tty, tty->ldisc);
+			else
+				err = 1;
+		}
+		/* If the re-open fails or we reset then go to N_TTY. The
+		   N_TTY open cannot fail */
+		if (reset || err) {
+			BUG_ON(tty_ldisc_reinit(tty, N_TTY));
+			WARN_ON(tty_ldisc_open(tty, tty->ldisc));
+		}
+		tty_ldisc_enable(tty);
+	}
+	mutex_unlock(&tty->ldisc_mutex);
+	if (reset)
+		tty_reset_termios(tty);
+}
+
+/**
+ *	tty_ldisc_setup			-	open line discipline
+ *	@tty: tty being shut down
+ *	@o_tty: pair tty for pty/tty pairs
+ *
+ *	Called during the initial open of a tty/pty pair in order to set up the
+ *	line disciplines and bind them to the tty. This has no locking issues
+ *	as the device isn't yet active.
+ */
+
+int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)
+{
+	struct tty_ldisc *ld = tty->ldisc;
+	int retval;
+
+	retval = tty_ldisc_open(tty, ld);
+	if (retval)
+		return retval;
+
+	if (o_tty) {
+		retval = tty_ldisc_open(o_tty, o_tty->ldisc);
+		if (retval) {
+			tty_ldisc_close(tty, ld);
+			return retval;
+		}
+		tty_ldisc_enable(o_tty);
+	}
+	tty_ldisc_enable(tty);
+	return 0;
+}
+/**
+ *	tty_ldisc_release		-	release line discipline
+ *	@tty: tty being shut down
+ *	@o_tty: pair tty for pty/tty pairs
+ *
+ *	Called during the final close of a tty/pty pair in order to shut down
+ *	the line discpline layer. On exit the ldisc assigned is N_TTY and the
+ *	ldisc has not been opened.
+ */
+
+void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
+{
+	/*
+	 * Prevent flush_to_ldisc() from rescheduling the work for later.  Then
+	 * kill any delayed work. As this is the final close it does not
+	 * race with the set_ldisc code path.
+	 */
+
+	tty_unlock();
+	tty_ldisc_halt(tty);
+	flush_scheduled_work();
+	tty_lock();
+
+	mutex_lock(&tty->ldisc_mutex);
+	/*
+	 * Now kill off the ldisc
+	 */
+	tty_ldisc_close(tty, tty->ldisc);
+	tty_ldisc_put(tty->ldisc);
+	/* Force an oops if we mess this up */
+	tty->ldisc = NULL;
+
+	/* Ensure the next open requests the N_TTY ldisc */
+	tty_set_termios_ldisc(tty, N_TTY);
+	mutex_unlock(&tty->ldisc_mutex);
+
+	/* This will need doing differently if we need to lock */
+	if (o_tty)
+		tty_ldisc_release(o_tty, NULL);
+
+	/* And the memory resources remaining (buffers, termios) will be
+	   disposed of when the kref hits zero */
+}
+
+/**
+ *	tty_ldisc_init		-	ldisc setup for new tty
+ *	@tty: tty being allocated
+ *
+ *	Set up the line discipline objects for a newly allocated tty. Note that
+ *	the tty structure is not completely set up when this call is made.
+ */
+
+void tty_ldisc_init(struct tty_struct *tty)
+{
+	struct tty_ldisc *ld = tty_ldisc_get(N_TTY);
+	if (IS_ERR(ld))
+		panic("n_tty: init_tty");
+	tty_ldisc_assign(tty, ld);
+}
+
+void tty_ldisc_begin(void)
+{
+	/* Setup the default TTY line discipline. */
+	(void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
+}
diff --git a/drivers/tty/tty_mutex.c b/drivers/tty/tty_mutex.c
new file mode 100644
index 0000000..1336975
--- /dev/null
+++ b/drivers/tty/tty_mutex.c
@@ -0,0 +1,47 @@
+/*
+ * drivers/char/tty_lock.c
+ */
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/semaphore.h>
+#include <linux/sched.h>
+
+/*
+ * The 'big tty mutex'
+ *
+ * This mutex is taken and released by tty_lock() and tty_unlock(),
+ * replacing the older big kernel lock.
+ * It can no longer be taken recursively, and does not get
+ * released implicitly while sleeping.
+ *
+ * Don't use in new code.
+ */
+static DEFINE_MUTEX(big_tty_mutex);
+struct task_struct *__big_tty_mutex_owner;
+EXPORT_SYMBOL_GPL(__big_tty_mutex_owner);
+
+/*
+ * Getting the big tty mutex.
+ */
+void __lockfunc tty_lock(void)
+{
+	struct task_struct *task = current;
+
+	WARN_ON(__big_tty_mutex_owner == task);
+
+	mutex_lock(&big_tty_mutex);
+	__big_tty_mutex_owner = task;
+}
+EXPORT_SYMBOL(tty_lock);
+
+void __lockfunc tty_unlock(void)
+{
+	struct task_struct *task = current;
+
+	WARN_ON(__big_tty_mutex_owner != task);
+	__big_tty_mutex_owner = NULL;
+
+	mutex_unlock(&big_tty_mutex);
+}
+EXPORT_SYMBOL(tty_unlock);
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
new file mode 100644
index 0000000..33d37d2
--- /dev/null
+++ b/drivers/tty/tty_port.c
@@ -0,0 +1,446 @@
+/*
+ * Tty port functions
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+
+void tty_port_init(struct tty_port *port)
+{
+	memset(port, 0, sizeof(*port));
+	init_waitqueue_head(&port->open_wait);
+	init_waitqueue_head(&port->close_wait);
+	init_waitqueue_head(&port->delta_msr_wait);
+	mutex_init(&port->mutex);
+	mutex_init(&port->buf_mutex);
+	spin_lock_init(&port->lock);
+	port->close_delay = (50 * HZ) / 100;
+	port->closing_wait = (3000 * HZ) / 100;
+	kref_init(&port->kref);
+}
+EXPORT_SYMBOL(tty_port_init);
+
+int tty_port_alloc_xmit_buf(struct tty_port *port)
+{
+	/* We may sleep in get_zeroed_page() */
+	mutex_lock(&port->buf_mutex);
+	if (port->xmit_buf == NULL)
+		port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
+	mutex_unlock(&port->buf_mutex);
+	if (port->xmit_buf == NULL)
+		return -ENOMEM;
+	return 0;
+}
+EXPORT_SYMBOL(tty_port_alloc_xmit_buf);
+
+void tty_port_free_xmit_buf(struct tty_port *port)
+{
+	mutex_lock(&port->buf_mutex);
+	if (port->xmit_buf != NULL) {
+		free_page((unsigned long)port->xmit_buf);
+		port->xmit_buf = NULL;
+	}
+	mutex_unlock(&port->buf_mutex);
+}
+EXPORT_SYMBOL(tty_port_free_xmit_buf);
+
+static void tty_port_destructor(struct kref *kref)
+{
+	struct tty_port *port = container_of(kref, struct tty_port, kref);
+	if (port->xmit_buf)
+		free_page((unsigned long)port->xmit_buf);
+	if (port->ops->destruct)
+		port->ops->destruct(port);
+	else
+		kfree(port);
+}
+
+void tty_port_put(struct tty_port *port)
+{
+	if (port)
+		kref_put(&port->kref, tty_port_destructor);
+}
+EXPORT_SYMBOL(tty_port_put);
+
+/**
+ *	tty_port_tty_get	-	get a tty reference
+ *	@port: tty port
+ *
+ *	Return a refcount protected tty instance or NULL if the port is not
+ *	associated with a tty (eg due to close or hangup)
+ */
+
+struct tty_struct *tty_port_tty_get(struct tty_port *port)
+{
+	unsigned long flags;
+	struct tty_struct *tty;
+
+	spin_lock_irqsave(&port->lock, flags);
+	tty = tty_kref_get(port->tty);
+	spin_unlock_irqrestore(&port->lock, flags);
+	return tty;
+}
+EXPORT_SYMBOL(tty_port_tty_get);
+
+/**
+ *	tty_port_tty_set	-	set the tty of a port
+ *	@port: tty port
+ *	@tty: the tty
+ *
+ *	Associate the port and tty pair. Manages any internal refcounts.
+ *	Pass NULL to deassociate a port
+ */
+
+void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (port->tty)
+		tty_kref_put(port->tty);
+	port->tty = tty_kref_get(tty);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+EXPORT_SYMBOL(tty_port_tty_set);
+
+static void tty_port_shutdown(struct tty_port *port)
+{
+	mutex_lock(&port->mutex);
+	if (port->ops->shutdown && !port->console &&
+		test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags))
+			port->ops->shutdown(port);
+	mutex_unlock(&port->mutex);
+}
+
+/**
+ *	tty_port_hangup		-	hangup helper
+ *	@port: tty port
+ *
+ *	Perform port level tty hangup flag and count changes. Drop the tty
+ *	reference.
+ */
+
+void tty_port_hangup(struct tty_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	port->count = 0;
+	port->flags &= ~ASYNC_NORMAL_ACTIVE;
+	if (port->tty) {
+		set_bit(TTY_IO_ERROR, &port->tty->flags);
+		tty_kref_put(port->tty);
+	}
+	port->tty = NULL;
+	spin_unlock_irqrestore(&port->lock, flags);
+	wake_up_interruptible(&port->open_wait);
+	wake_up_interruptible(&port->delta_msr_wait);
+	tty_port_shutdown(port);
+}
+EXPORT_SYMBOL(tty_port_hangup);
+
+/**
+ *	tty_port_carrier_raised	-	carrier raised check
+ *	@port: tty port
+ *
+ *	Wrapper for the carrier detect logic. For the moment this is used
+ *	to hide some internal details. This will eventually become entirely
+ *	internal to the tty port.
+ */
+
+int tty_port_carrier_raised(struct tty_port *port)
+{
+	if (port->ops->carrier_raised == NULL)
+		return 1;
+	return port->ops->carrier_raised(port);
+}
+EXPORT_SYMBOL(tty_port_carrier_raised);
+
+/**
+ *	tty_port_raise_dtr_rts	-	Raise DTR/RTS
+ *	@port: tty port
+ *
+ *	Wrapper for the DTR/RTS raise logic. For the moment this is used
+ *	to hide some internal details. This will eventually become entirely
+ *	internal to the tty port.
+ */
+
+void tty_port_raise_dtr_rts(struct tty_port *port)
+{
+	if (port->ops->dtr_rts)
+		port->ops->dtr_rts(port, 1);
+}
+EXPORT_SYMBOL(tty_port_raise_dtr_rts);
+
+/**
+ *	tty_port_lower_dtr_rts	-	Lower DTR/RTS
+ *	@port: tty port
+ *
+ *	Wrapper for the DTR/RTS raise logic. For the moment this is used
+ *	to hide some internal details. This will eventually become entirely
+ *	internal to the tty port.
+ */
+
+void tty_port_lower_dtr_rts(struct tty_port *port)
+{
+	if (port->ops->dtr_rts)
+		port->ops->dtr_rts(port, 0);
+}
+EXPORT_SYMBOL(tty_port_lower_dtr_rts);
+
+/**
+ *	tty_port_block_til_ready	-	Waiting logic for tty open
+ *	@port: the tty port being opened
+ *	@tty: the tty device being bound
+ *	@filp: the file pointer of the opener
+ *
+ *	Implement the core POSIX/SuS tty behaviour when opening a tty device.
+ *	Handles:
+ *		- hangup (both before and during)
+ *		- non blocking open
+ *		- rts/dtr/dcd
+ *		- signals
+ *		- port flags and counts
+ *
+ *	The passed tty_port must implement the carrier_raised method if it can
+ *	do carrier detect and the dtr_rts method if it supports software
+ *	management of these lines. Note that the dtr/rts raise is done each
+ *	iteration as a hangup may have previously dropped them while we wait.
+ */
+
+int tty_port_block_til_ready(struct tty_port *port,
+				struct tty_struct *tty, struct file *filp)
+{
+	int do_clocal = 0, retval;
+	unsigned long flags;
+	DEFINE_WAIT(wait);
+	int cd;
+
+	/* block if port is in the process of being closed */
+	if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
+		wait_event_interruptible_tty(port->close_wait,
+				!(port->flags & ASYNC_CLOSING));
+		if (port->flags & ASYNC_HUP_NOTIFY)
+			return -EAGAIN;
+		else
+			return -ERESTARTSYS;
+	}
+
+	/* if non-blocking mode is set we can pass directly to open unless
+	   the port has just hung up or is in another error state */
+	if (tty->flags & (1 << TTY_IO_ERROR)) {
+		port->flags |= ASYNC_NORMAL_ACTIVE;
+		return 0;
+	}
+	if (filp->f_flags & O_NONBLOCK) {
+		/* Indicate we are open */
+		if (tty->termios->c_cflag & CBAUD)
+			tty_port_raise_dtr_rts(port);
+		port->flags |= ASYNC_NORMAL_ACTIVE;
+		return 0;
+	}
+
+	if (C_CLOCAL(tty))
+		do_clocal = 1;
+
+	/* Block waiting until we can proceed. We may need to wait for the
+	   carrier, but we must also wait for any close that is in progress
+	   before the next open may complete */
+
+	retval = 0;
+
+	/* The port lock protects the port counts */
+	spin_lock_irqsave(&port->lock, flags);
+	if (!tty_hung_up_p(filp))
+		port->count--;
+	port->blocked_open++;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	while (1) {
+		/* Indicate we are open */
+		if (tty->termios->c_cflag & CBAUD)
+			tty_port_raise_dtr_rts(port);
+
+		prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);
+		/* Check for a hangup or uninitialised port.
+							Return accordingly */
+		if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) {
+			if (port->flags & ASYNC_HUP_NOTIFY)
+				retval = -EAGAIN;
+			else
+				retval = -ERESTARTSYS;
+			break;
+		}
+		/* Probe the carrier. For devices with no carrier detect this
+		   will always return true */
+		cd = tty_port_carrier_raised(port);
+		if (!(port->flags & ASYNC_CLOSING) &&
+				(do_clocal || cd))
+			break;
+		if (signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			break;
+		}
+		tty_unlock();
+		schedule();
+		tty_lock();
+	}
+	finish_wait(&port->open_wait, &wait);
+
+	/* Update counts. A parallel hangup will have set count to zero and
+	   we must not mess that up further */
+	spin_lock_irqsave(&port->lock, flags);
+	if (!tty_hung_up_p(filp))
+		port->count++;
+	port->blocked_open--;
+	if (retval == 0)
+		port->flags |= ASYNC_NORMAL_ACTIVE;
+	spin_unlock_irqrestore(&port->lock, flags);
+	return retval;
+}
+EXPORT_SYMBOL(tty_port_block_til_ready);
+
+int tty_port_close_start(struct tty_port *port,
+				struct tty_struct *tty, struct file *filp)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (tty_hung_up_p(filp)) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		return 0;
+	}
+
+	if (tty->count == 1 && port->count != 1) {
+		printk(KERN_WARNING
+		    "tty_port_close_start: tty->count = 1 port count = %d.\n",
+								port->count);
+		port->count = 1;
+	}
+	if (--port->count < 0) {
+		printk(KERN_WARNING "tty_port_close_start: count = %d\n",
+								port->count);
+		port->count = 0;
+	}
+
+	if (port->count) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		if (port->ops->drop)
+			port->ops->drop(port);
+		return 0;
+	}
+	set_bit(ASYNCB_CLOSING, &port->flags);
+	tty->closing = 1;
+	spin_unlock_irqrestore(&port->lock, flags);
+	/* Don't block on a stalled port, just pull the chain */
+	if (tty->flow_stopped)
+		tty_driver_flush_buffer(tty);
+	if (test_bit(ASYNCB_INITIALIZED, &port->flags) &&
+			port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
+		tty_wait_until_sent(tty, port->closing_wait);
+	if (port->drain_delay) {
+		unsigned int bps = tty_get_baud_rate(tty);
+		long timeout;
+
+		if (bps > 1200)
+			timeout = max_t(long,
+				(HZ * 10 * port->drain_delay) / bps, HZ / 10);
+		else
+			timeout = 2 * HZ;
+		schedule_timeout_interruptible(timeout);
+	}
+	/* Flush the ldisc buffering */
+	tty_ldisc_flush(tty);
+
+	/* Drop DTR/RTS if HUPCL is set. This causes any attached modem to
+	   hang up the line */
+	if (tty->termios->c_cflag & HUPCL)
+		tty_port_lower_dtr_rts(port);
+
+	/* Don't call port->drop for the last reference. Callers will want
+	   to drop the last active reference in ->shutdown() or the tty
+	   shutdown path */
+	return 1;
+}
+EXPORT_SYMBOL(tty_port_close_start);
+
+void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	tty->closing = 0;
+
+	if (port->blocked_open) {
+		spin_unlock_irqrestore(&port->lock, flags);
+		if (port->close_delay) {
+			msleep_interruptible(
+				jiffies_to_msecs(port->close_delay));
+		}
+		spin_lock_irqsave(&port->lock, flags);
+		wake_up_interruptible(&port->open_wait);
+	}
+	port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING);
+	wake_up_interruptible(&port->close_wait);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+EXPORT_SYMBOL(tty_port_close_end);
+
+void tty_port_close(struct tty_port *port, struct tty_struct *tty,
+							struct file *filp)
+{
+	if (tty_port_close_start(port, tty, filp) == 0)
+		return;
+	tty_port_shutdown(port);
+	set_bit(TTY_IO_ERROR, &tty->flags);
+	tty_port_close_end(port, tty);
+	tty_port_tty_set(port, NULL);
+}
+EXPORT_SYMBOL(tty_port_close);
+
+int tty_port_open(struct tty_port *port, struct tty_struct *tty,
+							struct file *filp)
+{
+	spin_lock_irq(&port->lock);
+	if (!tty_hung_up_p(filp))
+		++port->count;
+	spin_unlock_irq(&port->lock);
+	tty_port_tty_set(port, tty);
+
+	/*
+	 * Do the device-specific open only if the hardware isn't
+	 * already initialized. Serialize open and shutdown using the
+	 * port mutex.
+	 */
+
+	mutex_lock(&port->mutex);
+
+	if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) {
+		clear_bit(TTY_IO_ERROR, &tty->flags);
+		if (port->ops->activate) {
+			int retval = port->ops->activate(port, tty);
+			if (retval) {
+				mutex_unlock(&port->mutex);
+				return retval;
+			}
+		}
+		set_bit(ASYNCB_INITIALIZED, &port->flags);
+	}
+	mutex_unlock(&port->mutex);
+	return tty_port_block_til_ready(port, tty, filp);
+}
+
+EXPORT_SYMBOL(tty_port_open);
diff --git a/drivers/tty/vt/.gitignore b/drivers/tty/vt/.gitignore
new file mode 100644
index 0000000..83683a2
--- /dev/null
+++ b/drivers/tty/vt/.gitignore
@@ -0,0 +1,2 @@
+consolemap_deftbl.c
+defkeymap.c
diff --git a/drivers/tty/vt/Makefile b/drivers/tty/vt/Makefile
new file mode 100644
index 0000000..14a51c9
--- /dev/null
+++ b/drivers/tty/vt/Makefile
@@ -0,0 +1,34 @@
+#
+# This file contains the font map for the default (hardware) font
+#
+FONTMAPFILE = cp437.uni
+
+obj-$(CONFIG_VT)			+= vt_ioctl.o vc_screen.o \
+					   selection.o keyboard.o
+obj-$(CONFIG_CONSOLE_TRANSLATIONS)	+= consolemap.o consolemap_deftbl.o
+obj-$(CONFIG_HW_CONSOLE)		+= vt.o defkeymap.o
+
+# Files generated that shall be removed upon make clean
+clean-files := consolemap_deftbl.c defkeymap.c
+
+quiet_cmd_conmk = CONMK   $@
+      cmd_conmk = scripts/conmakehash $< > $@
+
+$(obj)/consolemap_deftbl.c: $(src)/$(FONTMAPFILE)
+	$(call cmd,conmk)
+
+$(obj)/defkeymap.o:  $(obj)/defkeymap.c
+
+# Uncomment if you're changing the keymap and have an appropriate
+# loadkeys version for the map. By default, we'll use the shipped
+# versions.
+# GENERATE_KEYMAP := 1
+
+ifdef GENERATE_KEYMAP
+
+$(obj)/defkeymap.c: $(obj)/%.c: $(src)/%.map
+	loadkeys --mktable $< > $@.tmp
+	sed -e 's/^static *//' $@.tmp > $@
+	rm $@.tmp
+
+endif
diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
new file mode 100644
index 0000000..45d3e80
--- /dev/null
+++ b/drivers/tty/vt/consolemap.c
@@ -0,0 +1,745 @@
+/*
+ * consolemap.c
+ *
+ * Mapping from internal code (such as Latin-1 or Unicode or IBM PC code)
+ * to font positions.
+ *
+ * aeb, 950210
+ *
+ * Support for multiple unimaps by Jakub Jelinek <jj@ultra.linux.cz>, July 1998
+ *
+ * Fix bug in inverse translation. Stanislav Voronyi <stas@cnti.uanet.kharkov.ua>, Dec 1998
+ */
+
+#include <linux/module.h>
+#include <linux/kd.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/tty.h>
+#include <asm/uaccess.h>
+#include <linux/consolemap.h>
+#include <linux/vt_kern.h>
+
+static unsigned short translations[][256] = {
+  /* 8-bit Latin-1 mapped to Unicode -- trivial mapping */
+  {
+    0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
+    0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
+    0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
+    0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f,
+    0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
+    0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
+    0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
+    0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
+    0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
+    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
+    0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
+    0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
+    0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
+    0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
+    0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
+    0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x007f,
+    0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087,
+    0x0088, 0x0089, 0x008a, 0x008b, 0x008c, 0x008d, 0x008e, 0x008f,
+    0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097,
+    0x0098, 0x0099, 0x009a, 0x009b, 0x009c, 0x009d, 0x009e, 0x009f,
+    0x00a0, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
+    0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x00ad, 0x00ae, 0x00af,
+    0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
+    0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
+    0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
+    0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
+    0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
+    0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
+    0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7,
+    0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
+    0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
+    0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff
+  }, 
+  /* VT100 graphics mapped to Unicode */
+  {
+    0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
+    0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
+    0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
+    0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f,
+    0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
+    0x0028, 0x0029, 0x002a, 0x2192, 0x2190, 0x2191, 0x2193, 0x002f,
+    0x2588, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
+    0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
+    0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
+    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
+    0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
+    0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x00a0,
+    0x25c6, 0x2592, 0x2409, 0x240c, 0x240d, 0x240a, 0x00b0, 0x00b1,
+    0x2591, 0x240b, 0x2518, 0x2510, 0x250c, 0x2514, 0x253c, 0x23ba,
+    0x23bb, 0x2500, 0x23bc, 0x23bd, 0x251c, 0x2524, 0x2534, 0x252c,
+    0x2502, 0x2264, 0x2265, 0x03c0, 0x2260, 0x00a3, 0x00b7, 0x007f,
+    0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087,
+    0x0088, 0x0089, 0x008a, 0x008b, 0x008c, 0x008d, 0x008e, 0x008f,
+    0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097,
+    0x0098, 0x0099, 0x009a, 0x009b, 0x009c, 0x009d, 0x009e, 0x009f,
+    0x00a0, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
+    0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x00ad, 0x00ae, 0x00af,
+    0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
+    0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
+    0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
+    0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
+    0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
+    0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
+    0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7,
+    0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
+    0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
+    0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff
+  },
+  /* IBM Codepage 437 mapped to Unicode */
+  {
+    0x0000, 0x263a, 0x263b, 0x2665, 0x2666, 0x2663, 0x2660, 0x2022, 
+    0x25d8, 0x25cb, 0x25d9, 0x2642, 0x2640, 0x266a, 0x266b, 0x263c,
+    0x25b6, 0x25c0, 0x2195, 0x203c, 0x00b6, 0x00a7, 0x25ac, 0x21a8,
+    0x2191, 0x2193, 0x2192, 0x2190, 0x221f, 0x2194, 0x25b2, 0x25bc,
+    0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
+    0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
+    0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
+    0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
+    0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
+    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
+    0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
+    0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
+    0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
+    0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
+    0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
+    0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x2302,
+    0x00c7, 0x00fc, 0x00e9, 0x00e2, 0x00e4, 0x00e0, 0x00e5, 0x00e7,
+    0x00ea, 0x00eb, 0x00e8, 0x00ef, 0x00ee, 0x00ec, 0x00c4, 0x00c5,
+    0x00c9, 0x00e6, 0x00c6, 0x00f4, 0x00f6, 0x00f2, 0x00fb, 0x00f9,
+    0x00ff, 0x00d6, 0x00dc, 0x00a2, 0x00a3, 0x00a5, 0x20a7, 0x0192,
+    0x00e1, 0x00ed, 0x00f3, 0x00fa, 0x00f1, 0x00d1, 0x00aa, 0x00ba,
+    0x00bf, 0x2310, 0x00ac, 0x00bd, 0x00bc, 0x00a1, 0x00ab, 0x00bb,
+    0x2591, 0x2592, 0x2593, 0x2502, 0x2524, 0x2561, 0x2562, 0x2556,
+    0x2555, 0x2563, 0x2551, 0x2557, 0x255d, 0x255c, 0x255b, 0x2510,
+    0x2514, 0x2534, 0x252c, 0x251c, 0x2500, 0x253c, 0x255e, 0x255f,
+    0x255a, 0x2554, 0x2569, 0x2566, 0x2560, 0x2550, 0x256c, 0x2567,
+    0x2568, 0x2564, 0x2565, 0x2559, 0x2558, 0x2552, 0x2553, 0x256b,
+    0x256a, 0x2518, 0x250c, 0x2588, 0x2584, 0x258c, 0x2590, 0x2580,
+    0x03b1, 0x00df, 0x0393, 0x03c0, 0x03a3, 0x03c3, 0x00b5, 0x03c4,
+    0x03a6, 0x0398, 0x03a9, 0x03b4, 0x221e, 0x03c6, 0x03b5, 0x2229,
+    0x2261, 0x00b1, 0x2265, 0x2264, 0x2320, 0x2321, 0x00f7, 0x2248,
+    0x00b0, 0x2219, 0x00b7, 0x221a, 0x207f, 0x00b2, 0x25a0, 0x00a0
+  }, 
+  /* User mapping -- default to codes for direct font mapping */
+  {
+    0xf000, 0xf001, 0xf002, 0xf003, 0xf004, 0xf005, 0xf006, 0xf007,
+    0xf008, 0xf009, 0xf00a, 0xf00b, 0xf00c, 0xf00d, 0xf00e, 0xf00f,
+    0xf010, 0xf011, 0xf012, 0xf013, 0xf014, 0xf015, 0xf016, 0xf017,
+    0xf018, 0xf019, 0xf01a, 0xf01b, 0xf01c, 0xf01d, 0xf01e, 0xf01f,
+    0xf020, 0xf021, 0xf022, 0xf023, 0xf024, 0xf025, 0xf026, 0xf027,
+    0xf028, 0xf029, 0xf02a, 0xf02b, 0xf02c, 0xf02d, 0xf02e, 0xf02f,
+    0xf030, 0xf031, 0xf032, 0xf033, 0xf034, 0xf035, 0xf036, 0xf037,
+    0xf038, 0xf039, 0xf03a, 0xf03b, 0xf03c, 0xf03d, 0xf03e, 0xf03f,
+    0xf040, 0xf041, 0xf042, 0xf043, 0xf044, 0xf045, 0xf046, 0xf047,
+    0xf048, 0xf049, 0xf04a, 0xf04b, 0xf04c, 0xf04d, 0xf04e, 0xf04f,
+    0xf050, 0xf051, 0xf052, 0xf053, 0xf054, 0xf055, 0xf056, 0xf057,
+    0xf058, 0xf059, 0xf05a, 0xf05b, 0xf05c, 0xf05d, 0xf05e, 0xf05f,
+    0xf060, 0xf061, 0xf062, 0xf063, 0xf064, 0xf065, 0xf066, 0xf067,
+    0xf068, 0xf069, 0xf06a, 0xf06b, 0xf06c, 0xf06d, 0xf06e, 0xf06f,
+    0xf070, 0xf071, 0xf072, 0xf073, 0xf074, 0xf075, 0xf076, 0xf077,
+    0xf078, 0xf079, 0xf07a, 0xf07b, 0xf07c, 0xf07d, 0xf07e, 0xf07f,
+    0xf080, 0xf081, 0xf082, 0xf083, 0xf084, 0xf085, 0xf086, 0xf087,
+    0xf088, 0xf089, 0xf08a, 0xf08b, 0xf08c, 0xf08d, 0xf08e, 0xf08f,
+    0xf090, 0xf091, 0xf092, 0xf093, 0xf094, 0xf095, 0xf096, 0xf097,
+    0xf098, 0xf099, 0xf09a, 0xf09b, 0xf09c, 0xf09d, 0xf09e, 0xf09f,
+    0xf0a0, 0xf0a1, 0xf0a2, 0xf0a3, 0xf0a4, 0xf0a5, 0xf0a6, 0xf0a7,
+    0xf0a8, 0xf0a9, 0xf0aa, 0xf0ab, 0xf0ac, 0xf0ad, 0xf0ae, 0xf0af,
+    0xf0b0, 0xf0b1, 0xf0b2, 0xf0b3, 0xf0b4, 0xf0b5, 0xf0b6, 0xf0b7,
+    0xf0b8, 0xf0b9, 0xf0ba, 0xf0bb, 0xf0bc, 0xf0bd, 0xf0be, 0xf0bf,
+    0xf0c0, 0xf0c1, 0xf0c2, 0xf0c3, 0xf0c4, 0xf0c5, 0xf0c6, 0xf0c7,
+    0xf0c8, 0xf0c9, 0xf0ca, 0xf0cb, 0xf0cc, 0xf0cd, 0xf0ce, 0xf0cf,
+    0xf0d0, 0xf0d1, 0xf0d2, 0xf0d3, 0xf0d4, 0xf0d5, 0xf0d6, 0xf0d7,
+    0xf0d8, 0xf0d9, 0xf0da, 0xf0db, 0xf0dc, 0xf0dd, 0xf0de, 0xf0df,
+    0xf0e0, 0xf0e1, 0xf0e2, 0xf0e3, 0xf0e4, 0xf0e5, 0xf0e6, 0xf0e7,
+    0xf0e8, 0xf0e9, 0xf0ea, 0xf0eb, 0xf0ec, 0xf0ed, 0xf0ee, 0xf0ef,
+    0xf0f0, 0xf0f1, 0xf0f2, 0xf0f3, 0xf0f4, 0xf0f5, 0xf0f6, 0xf0f7,
+    0xf0f8, 0xf0f9, 0xf0fa, 0xf0fb, 0xf0fc, 0xf0fd, 0xf0fe, 0xf0ff
+  }
+};
+
+/* The standard kernel character-to-font mappings are not invertible
+   -- this is just a best effort. */
+
+#define MAX_GLYPH 512		/* Max possible glyph value */
+
+static int inv_translate[MAX_NR_CONSOLES];
+
+struct uni_pagedir {
+	u16 		**uni_pgdir[32];
+	unsigned long	refcount;
+	unsigned long	sum;
+	unsigned char	*inverse_translations[4];
+	u16		*inverse_trans_unicode;
+	int		readonly;
+};
+
+static struct uni_pagedir *dflt;
+
+static void set_inverse_transl(struct vc_data *conp, struct uni_pagedir *p, int i)
+{
+	int j, glyph;
+	unsigned short *t = translations[i];
+	unsigned char *q;
+	
+	if (!p) return;
+	q = p->inverse_translations[i];
+
+	if (!q) {
+		q = p->inverse_translations[i] = (unsigned char *) 
+			kmalloc(MAX_GLYPH, GFP_KERNEL);
+		if (!q) return;
+	}
+	memset(q, 0, MAX_GLYPH);
+
+	for (j = 0; j < E_TABSZ; j++) {
+		glyph = conv_uni_to_pc(conp, t[j]);
+		if (glyph >= 0 && glyph < MAX_GLYPH && q[glyph] < 32) {
+			/* prefer '-' above SHY etc. */
+		  	q[glyph] = j;
+		}
+	}
+}
+
+static void set_inverse_trans_unicode(struct vc_data *conp,
+				      struct uni_pagedir *p)
+{
+	int i, j, k, glyph;
+	u16 **p1, *p2;
+	u16 *q;
+
+	if (!p) return;
+	q = p->inverse_trans_unicode;
+	if (!q) {
+		q = p->inverse_trans_unicode =
+			kmalloc(MAX_GLYPH * sizeof(u16), GFP_KERNEL);
+		if (!q)
+			return;
+	}
+	memset(q, 0, MAX_GLYPH * sizeof(u16));
+
+	for (i = 0; i < 32; i++) {
+		p1 = p->uni_pgdir[i];
+		if (!p1)
+			continue;
+		for (j = 0; j < 32; j++) {
+			p2 = p1[j];
+			if (!p2)
+				continue;
+			for (k = 0; k < 64; k++) {
+				glyph = p2[k];
+				if (glyph >= 0 && glyph < MAX_GLYPH
+					       && q[glyph] < 32)
+		  			q[glyph] = (i << 11) + (j << 6) + k;
+			}
+		}
+	}
+}
+
+unsigned short *set_translate(int m, struct vc_data *vc)
+{
+	inv_translate[vc->vc_num] = m;
+	return translations[m];
+}
+
+/*
+ * Inverse translation is impossible for several reasons:
+ * 1. The font<->character maps are not 1-1.
+ * 2. The text may have been written while a different translation map
+ *    was active.
+ * Still, it is now possible to a certain extent to cut and paste non-ASCII.
+ */
+u16 inverse_translate(struct vc_data *conp, int glyph, int use_unicode)
+{
+	struct uni_pagedir *p;
+	int m;
+	if (glyph < 0 || glyph >= MAX_GLYPH)
+		return 0;
+	else if (!(p = (struct uni_pagedir *)*conp->vc_uni_pagedir_loc))
+		return glyph;
+	else if (use_unicode) {
+		if (!p->inverse_trans_unicode)
+			return glyph;
+		else
+			return p->inverse_trans_unicode[glyph];
+	} else {
+		m = inv_translate[conp->vc_num];
+		if (!p->inverse_translations[m])
+			return glyph;
+		else
+			return p->inverse_translations[m][glyph];
+	}
+}
+EXPORT_SYMBOL_GPL(inverse_translate);
+
+static void update_user_maps(void)
+{
+	int i;
+	struct uni_pagedir *p, *q = NULL;
+	
+	for (i = 0; i < MAX_NR_CONSOLES; i++) {
+		if (!vc_cons_allocated(i))
+			continue;
+		p = (struct uni_pagedir *)*vc_cons[i].d->vc_uni_pagedir_loc;
+		if (p && p != q) {
+			set_inverse_transl(vc_cons[i].d, p, USER_MAP);
+			set_inverse_trans_unicode(vc_cons[i].d, p);
+			q = p;
+		}
+	}
+}
+
+/*
+ * Load customizable translation table
+ * arg points to a 256 byte translation table.
+ *
+ * The "old" variants are for translation directly to font (using the
+ * 0xf000-0xf0ff "transparent" Unicodes) whereas the "new" variants set
+ * Unicodes explicitly.
+ */
+int con_set_trans_old(unsigned char __user * arg)
+{
+	int i;
+	unsigned short *p = translations[USER_MAP];
+
+	if (!access_ok(VERIFY_READ, arg, E_TABSZ))
+		return -EFAULT;
+
+	for (i=0; i<E_TABSZ ; i++) {
+		unsigned char uc;
+		__get_user(uc, arg+i);
+		p[i] = UNI_DIRECT_BASE | uc;
+	}
+
+	update_user_maps();
+	return 0;
+}
+
+int con_get_trans_old(unsigned char __user * arg)
+{
+	int i, ch;
+	unsigned short *p = translations[USER_MAP];
+
+	if (!access_ok(VERIFY_WRITE, arg, E_TABSZ))
+		return -EFAULT;
+
+	for (i=0; i<E_TABSZ ; i++)
+	  {
+	    ch = conv_uni_to_pc(vc_cons[fg_console].d, p[i]);
+	    __put_user((ch & ~0xff) ? 0 : ch, arg+i);
+	  }
+	return 0;
+}
+
+int con_set_trans_new(ushort __user * arg)
+{
+	int i;
+	unsigned short *p = translations[USER_MAP];
+
+	if (!access_ok(VERIFY_READ, arg, E_TABSZ*sizeof(unsigned short)))
+		return -EFAULT;
+
+	for (i=0; i<E_TABSZ ; i++) {
+		unsigned short us;
+		__get_user(us, arg+i);
+		p[i] = us;
+	}
+
+	update_user_maps();
+	return 0;
+}
+
+int con_get_trans_new(ushort __user * arg)
+{
+	int i;
+	unsigned short *p = translations[USER_MAP];
+
+	if (!access_ok(VERIFY_WRITE, arg, E_TABSZ*sizeof(unsigned short)))
+		return -EFAULT;
+
+	for (i=0; i<E_TABSZ ; i++)
+	  __put_user(p[i], arg+i);
+	
+	return 0;
+}
+
+/*
+ * Unicode -> current font conversion 
+ *
+ * A font has at most 512 chars, usually 256.
+ * But one font position may represent several Unicode chars.
+ * A hashtable is somewhat of a pain to deal with, so use a
+ * "paged table" instead.  Simulation has shown the memory cost of
+ * this 3-level paged table scheme to be comparable to a hash table.
+ */
+
+extern u8 dfont_unicount[];	/* Defined in console_defmap.c */
+extern u16 dfont_unitable[];
+
+static void con_release_unimap(struct uni_pagedir *p)
+{
+	u16 **p1;
+	int i, j;
+
+	if (p == dflt) dflt = NULL;  
+	for (i = 0; i < 32; i++) {
+		if ((p1 = p->uni_pgdir[i]) != NULL) {
+			for (j = 0; j < 32; j++)
+				kfree(p1[j]);
+			kfree(p1);
+		}
+		p->uni_pgdir[i] = NULL;
+	}
+	for (i = 0; i < 4; i++) {
+		kfree(p->inverse_translations[i]);
+		p->inverse_translations[i] = NULL;
+	}
+	if (p->inverse_trans_unicode) {
+		kfree(p->inverse_trans_unicode);
+		p->inverse_trans_unicode = NULL;
+	}
+}
+
+void con_free_unimap(struct vc_data *vc)
+{
+	struct uni_pagedir *p;
+
+	p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
+	if (!p)
+		return;
+	*vc->vc_uni_pagedir_loc = 0;
+	if (--p->refcount)
+		return;
+	con_release_unimap(p);
+	kfree(p);
+}
+  
+static int con_unify_unimap(struct vc_data *conp, struct uni_pagedir *p)
+{
+	int i, j, k;
+	struct uni_pagedir *q;
+	
+	for (i = 0; i < MAX_NR_CONSOLES; i++) {
+		if (!vc_cons_allocated(i))
+			continue;
+		q = (struct uni_pagedir *)*vc_cons[i].d->vc_uni_pagedir_loc;
+		if (!q || q == p || q->sum != p->sum)
+			continue;
+		for (j = 0; j < 32; j++) {
+			u16 **p1, **q1;
+			p1 = p->uni_pgdir[j]; q1 = q->uni_pgdir[j];
+			if (!p1 && !q1)
+				continue;
+			if (!p1 || !q1)
+				break;
+			for (k = 0; k < 32; k++) {
+				if (!p1[k] && !q1[k])
+					continue;
+				if (!p1[k] || !q1[k])
+					break;
+				if (memcmp(p1[k], q1[k], 64*sizeof(u16)))
+					break;
+			}
+			if (k < 32)
+				break;
+		}
+		if (j == 32) {
+			q->refcount++;
+			*conp->vc_uni_pagedir_loc = (unsigned long)q;
+			con_release_unimap(p);
+			kfree(p);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static int
+con_insert_unipair(struct uni_pagedir *p, u_short unicode, u_short fontpos)
+{
+	int i, n;
+	u16 **p1, *p2;
+
+	if (!(p1 = p->uni_pgdir[n = unicode >> 11])) {
+		p1 = p->uni_pgdir[n] = kmalloc(32*sizeof(u16 *), GFP_KERNEL);
+		if (!p1) return -ENOMEM;
+		for (i = 0; i < 32; i++)
+			p1[i] = NULL;
+	}
+
+	if (!(p2 = p1[n = (unicode >> 6) & 0x1f])) {
+		p2 = p1[n] = kmalloc(64*sizeof(u16), GFP_KERNEL);
+		if (!p2) return -ENOMEM;
+		memset(p2, 0xff, 64*sizeof(u16)); /* No glyphs for the characters (yet) */
+	}
+
+	p2[unicode & 0x3f] = fontpos;
+	
+	p->sum += (fontpos << 20) + unicode;
+
+	return 0;
+}
+
+/* ui is a leftover from using a hashtable, but might be used again */
+int con_clear_unimap(struct vc_data *vc, struct unimapinit *ui)
+{
+	struct uni_pagedir *p, *q;
+  
+	p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
+	if (p && p->readonly) return -EIO;
+	if (!p || --p->refcount) {
+		q = kzalloc(sizeof(*p), GFP_KERNEL);
+		if (!q) {
+			if (p) p->refcount++;
+			return -ENOMEM;
+		}
+		q->refcount=1;
+		*vc->vc_uni_pagedir_loc = (unsigned long)q;
+	} else {
+		if (p == dflt) dflt = NULL;
+		p->refcount++;
+		p->sum = 0;
+		con_release_unimap(p);
+	}
+	return 0;
+}
+
+int con_set_unimap(struct vc_data *vc, ushort ct, struct unipair __user *list)
+{
+	int err = 0, err1, i;
+	struct uni_pagedir *p, *q;
+
+	p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
+	if (p->readonly) return -EIO;
+	
+	if (!ct) return 0;
+	
+	if (p->refcount > 1) {
+		int j, k;
+		u16 **p1, *p2, l;
+		
+		err1 = con_clear_unimap(vc, NULL);
+		if (err1) return err1;
+		
+		q = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
+		for (i = 0, l = 0; i < 32; i++)
+		if ((p1 = p->uni_pgdir[i]))
+			for (j = 0; j < 32; j++)
+			if ((p2 = p1[j]))
+				for (k = 0; k < 64; k++, l++)
+				if (p2[k] != 0xffff) {
+					err1 = con_insert_unipair(q, l, p2[k]);
+					if (err1) {
+						p->refcount++;
+						*vc->vc_uni_pagedir_loc = (unsigned long)p;
+						con_release_unimap(q);
+						kfree(q);
+						return err1; 
+					}
+              			}
+              	p = q;
+	} else if (p == dflt)
+		dflt = NULL;
+	
+	while (ct--) {
+		unsigned short unicode, fontpos;
+		__get_user(unicode, &list->unicode);
+		__get_user(fontpos, &list->fontpos);
+		if ((err1 = con_insert_unipair(p, unicode,fontpos)) != 0)
+			err = err1;
+		list++;
+	}
+	
+	if (con_unify_unimap(vc, p))
+		return err;
+
+	for (i = 0; i <= 3; i++)
+		set_inverse_transl(vc, p, i); /* Update all inverse translations */
+	set_inverse_trans_unicode(vc, p);
+  
+	return err;
+}
+
+/* Loads the unimap for the hardware font, as defined in uni_hash.tbl.
+   The representation used was the most compact I could come up
+   with.  This routine is executed at sys_setup time, and when the
+   PIO_FONTRESET ioctl is called. */
+
+int con_set_default_unimap(struct vc_data *vc)
+{
+	int i, j, err = 0, err1;
+	u16 *q;
+	struct uni_pagedir *p;
+
+	if (dflt) {
+		p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
+		if (p == dflt)
+			return 0;
+		dflt->refcount++;
+		*vc->vc_uni_pagedir_loc = (unsigned long)dflt;
+		if (p && --p->refcount) {
+			con_release_unimap(p);
+			kfree(p);
+		}
+		return 0;
+	}
+	
+	/* The default font is always 256 characters */
+
+	err = con_clear_unimap(vc, NULL);
+	if (err) return err;
+    
+	p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
+	q = dfont_unitable;
+	
+	for (i = 0; i < 256; i++)
+		for (j = dfont_unicount[i]; j; j--) {
+			err1 = con_insert_unipair(p, *(q++), i);
+			if (err1)
+				err = err1;
+		}
+			
+	if (con_unify_unimap(vc, p)) {
+		dflt = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
+		return err;
+	}
+
+	for (i = 0; i <= 3; i++)
+		set_inverse_transl(vc, p, i);	/* Update all inverse translations */
+	set_inverse_trans_unicode(vc, p);
+	dflt = p;
+	return err;
+}
+EXPORT_SYMBOL(con_set_default_unimap);
+
+int con_copy_unimap(struct vc_data *dst_vc, struct vc_data *src_vc)
+{
+	struct uni_pagedir *q;
+
+	if (!*src_vc->vc_uni_pagedir_loc)
+		return -EINVAL;
+	if (*dst_vc->vc_uni_pagedir_loc == *src_vc->vc_uni_pagedir_loc)
+		return 0;
+	con_free_unimap(dst_vc);
+	q = (struct uni_pagedir *)*src_vc->vc_uni_pagedir_loc;
+	q->refcount++;
+	*dst_vc->vc_uni_pagedir_loc = (long)q;
+	return 0;
+}
+
+int con_get_unimap(struct vc_data *vc, ushort ct, ushort __user *uct, struct unipair __user *list)
+{
+	int i, j, k, ect;
+	u16 **p1, *p2;
+	struct uni_pagedir *p;
+
+	ect = 0;
+	if (*vc->vc_uni_pagedir_loc) {
+		p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
+		for (i = 0; i < 32; i++)
+		if ((p1 = p->uni_pgdir[i]))
+			for (j = 0; j < 32; j++)
+			if ((p2 = *(p1++)))
+				for (k = 0; k < 64; k++) {
+					if (*p2 < MAX_GLYPH && ect++ < ct) {
+						__put_user((u_short)((i<<11)+(j<<6)+k),
+							   &list->unicode);
+						__put_user((u_short) *p2, 
+							   &list->fontpos);
+						list++;
+					}
+					p2++;
+				}
+	}
+	__put_user(ect, uct);
+	return ((ect <= ct) ? 0 : -ENOMEM);
+}
+
+void con_protect_unimap(struct vc_data *vc, int rdonly)
+{
+	struct uni_pagedir *p = (struct uni_pagedir *)*vc->vc_uni_pagedir_loc;
+	
+	if (p)
+		p->readonly = rdonly;
+}
+
+/*
+ * Always use USER_MAP. These functions are used by the keyboard,
+ * which shouldn't be affected by G0/G1 switching, etc.
+ * If the user map still contains default values, i.e. the
+ * direct-to-font mapping, then assume user is using Latin1.
+ */
+/* may be called during an interrupt */
+u32 conv_8bit_to_uni(unsigned char c)
+{
+	unsigned short uni = translations[USER_MAP][c];
+	return uni == (0xf000 | c) ? c : uni;
+}
+
+int conv_uni_to_8bit(u32 uni)
+{
+	int c;
+	for (c = 0; c < 0x100; c++)
+		if (translations[USER_MAP][c] == uni ||
+		   (translations[USER_MAP][c] == (c | 0xf000) && uni == c))
+			return c;
+	return -1;
+}
+
+int
+conv_uni_to_pc(struct vc_data *conp, long ucs) 
+{
+	int h;
+	u16 **p1, *p2;
+	struct uni_pagedir *p;
+  
+	/* Only 16-bit codes supported at this time */
+	if (ucs > 0xffff)
+		return -4;		/* Not found */
+	else if (ucs < 0x20)
+		return -1;		/* Not a printable character */
+	else if (ucs == 0xfeff || (ucs >= 0x200b && ucs <= 0x200f))
+		return -2;			/* Zero-width space */
+	/*
+	 * UNI_DIRECT_BASE indicates the start of the region in the User Zone
+	 * which always has a 1:1 mapping to the currently loaded font.  The
+	 * UNI_DIRECT_MASK indicates the bit span of the region.
+	 */
+	else if ((ucs & ~UNI_DIRECT_MASK) == UNI_DIRECT_BASE)
+		return ucs & UNI_DIRECT_MASK;
+  
+	if (!*conp->vc_uni_pagedir_loc)
+		return -3;
+
+	p = (struct uni_pagedir *)*conp->vc_uni_pagedir_loc;  
+	if ((p1 = p->uni_pgdir[ucs >> 11]) &&
+	    (p2 = p1[(ucs >> 6) & 0x1f]) &&
+	    (h = p2[ucs & 0x3f]) < MAX_GLYPH)
+		return h;
+
+	return -4;		/* not found */
+}
+
+/*
+ * This is called at sys_setup time, after memory and the console are
+ * initialized.  It must be possible to call kmalloc(..., GFP_KERNEL)
+ * from this function, hence the call from sys_setup.
+ */
+void __init 
+console_map_init(void)
+{
+	int i;
+	
+	for (i = 0; i < MAX_NR_CONSOLES; i++)
+		if (vc_cons_allocated(i) && !*vc_cons[i].d->vc_uni_pagedir_loc)
+			con_set_default_unimap(vc_cons[i].d);
+}
+
+EXPORT_SYMBOL(con_copy_unimap);
diff --git a/drivers/tty/vt/cp437.uni b/drivers/tty/vt/cp437.uni
new file mode 100644
index 0000000..bc61634
--- /dev/null
+++ b/drivers/tty/vt/cp437.uni
@@ -0,0 +1,291 @@
+#
+# Unicode table for IBM Codepage 437.  Note that there are many more
+# substitutions that could be conceived (for example, thick-line
+# graphs probably should be replaced with double-line ones, accented
+# Latin characters should replaced with their nonaccented versions,
+# and some upper case Greek characters could be replaced by Latin), however,
+# I have limited myself to the Unicodes used by the kernel ISO 8859-1,
+# DEC VT, and IBM CP 437 tables.
+#
+# --------------------------------
+#
+# Basic IBM dingbats, some of which will never have a purpose clear
+# to mankind
+#
+0x00	U+0000
+0x01	U+263a
+0x02	U+263b
+0x03	U+2665
+0x04	U+2666 U+25c6
+0x05	U+2663
+0x06	U+2660
+0x07	U+2022
+0x08	U+25d8
+0x09	U+25cb
+0x0a	U+25d9
+0x0b	U+2642
+0x0c	U+2640
+0x0d	U+266a
+0x0e	U+266b
+0x0f	U+263c U+00a4
+0x10	U+25b6 U+25ba
+0x11	U+25c0 U+25c4
+0x12	U+2195
+0x13	U+203c
+0x14	U+00b6
+0x15	U+00a7
+0x16	U+25ac
+0x17	U+21a8
+0x18	U+2191
+0x19	U+2193
+0x1a	U+2192
+0x1b	U+2190
+0x1c	U+221f
+0x1d	U+2194
+0x1e	U+25b2
+0x1f	U+25bc
+#
+# The ASCII range is identity-mapped, but some of the characters also
+# have to act as substitutes, especially the upper-case characters.
+#
+0x20	U+0020
+0x21	U+0021
+0x22	U+0022 U+00a8
+0x23	U+0023
+0x24	U+0024
+0x25	U+0025
+0x26	U+0026
+0x27	U+0027 U+00b4
+0x28	U+0028
+0x29	U+0029
+0x2a	U+002a
+0x2b	U+002b
+0x2c	U+002c U+00b8
+0x2d	U+002d U+00ad
+0x2e	U+002e
+0x2f	U+002f
+0x30	U+0030
+0x31	U+0031
+0x32	U+0032
+0x33	U+0033
+0x34	U+0034
+0x35	U+0035
+0x36	U+0036
+0x37	U+0037
+0x38	U+0038
+0x39	U+0039
+0x3a	U+003a
+0x3b	U+003b
+0x3c	U+003c
+0x3d	U+003d
+0x3e	U+003e
+0x3f	U+003f
+0x40	U+0040
+0x41	U+0041 U+00c0 U+00c1 U+00c2 U+00c3
+0x42	U+0042
+0x43	U+0043 U+00a9
+0x44	U+0044 U+00d0
+0x45	U+0045 U+00c8 U+00ca U+00cb
+0x46	U+0046
+0x47	U+0047
+0x48	U+0048
+0x49	U+0049 U+00cc U+00cd U+00ce U+00cf
+0x4a	U+004a
+0x4b	U+004b U+212a
+0x4c	U+004c
+0x4d	U+004d
+0x4e	U+004e
+0x4f	U+004f U+00d2 U+00d3 U+00d4 U+00d5
+0x50	U+0050
+0x51	U+0051
+0x52	U+0052 U+00ae
+0x53	U+0053
+0x54	U+0054
+0x55	U+0055 U+00d9 U+00da U+00db
+0x56	U+0056
+0x57	U+0057
+0x58	U+0058
+0x59	U+0059 U+00dd
+0x5a	U+005a
+0x5b	U+005b
+0x5c	U+005c
+0x5d	U+005d
+0x5e	U+005e
+0x5f	U+005f U+23bd U+f804
+0x60	U+0060
+0x61	U+0061 U+00e3
+0x62	U+0062
+0x63	U+0063
+0x64	U+0064
+0x65	U+0065
+0x66	U+0066
+0x67	U+0067
+0x68	U+0068
+0x69	U+0069
+0x6a	U+006a
+0x6b	U+006b
+0x6c	U+006c
+0x6d	U+006d
+0x6e	U+006e
+0x6f	U+006f U+00f5
+0x70	U+0070
+0x71	U+0071
+0x72	U+0072
+0x73	U+0073
+0x74	U+0074
+0x75	U+0075
+0x76	U+0076
+0x77	U+0077
+0x78	U+0078 U+00d7
+0x79	U+0079 U+00fd
+0x7a	U+007a
+0x7b	U+007b
+0x7c	U+007c U+00a6
+0x7d	U+007d
+0x7e	U+007e
+#
+# Okay, what on Earth is this one supposed to be used for?
+#
+0x7f	U+2302
+#
+# Non-English characters, mostly lower case letters...
+#
+0x80	U+00c7
+0x81	U+00fc
+0x82	U+00e9
+0x83	U+00e2
+0x84	U+00e4
+0x85	U+00e0
+0x86	U+00e5
+0x87	U+00e7
+0x88	U+00ea
+0x89	U+00eb
+0x8a	U+00e8
+0x8b	U+00ef
+0x8c	U+00ee
+0x8d	U+00ec
+0x8e	U+00c4
+0x8f	U+00c5 U+212b
+0x90	U+00c9
+0x91	U+00e6
+0x92	U+00c6
+0x93	U+00f4
+0x94	U+00f6
+0x95	U+00f2
+0x96	U+00fb
+0x97	U+00f9
+0x98	U+00ff
+0x99	U+00d6
+0x9a	U+00dc
+0x9b	U+00a2
+0x9c	U+00a3
+0x9d	U+00a5
+0x9e	U+20a7
+0x9f	U+0192
+0xa0	U+00e1
+0xa1	U+00ed
+0xa2	U+00f3
+0xa3	U+00fa
+0xa4	U+00f1
+0xa5	U+00d1
+0xa6	U+00aa
+0xa7	U+00ba
+0xa8	U+00bf
+0xa9	U+2310
+0xaa	U+00ac
+0xab	U+00bd
+0xac	U+00bc
+0xad	U+00a1
+0xae	U+00ab
+0xaf	U+00bb
+#
+# Block graphics
+#
+0xb0	U+2591
+0xb1	U+2592
+0xb2	U+2593
+0xb3	U+2502
+0xb4	U+2524
+0xb5	U+2561
+0xb6	U+2562
+0xb7	U+2556
+0xb8	U+2555
+0xb9	U+2563
+0xba	U+2551
+0xbb	U+2557
+0xbc	U+255d
+0xbd	U+255c
+0xbe	U+255b
+0xbf	U+2510
+0xc0	U+2514
+0xc1	U+2534
+0xc2	U+252c
+0xc3	U+251c
+0xc4	U+2500
+0xc5	U+253c
+0xc6	U+255e
+0xc7	U+255f
+0xc8	U+255a
+0xc9	U+2554
+0xca	U+2569
+0xcb	U+2566
+0xcc	U+2560
+0xcd	U+2550
+0xce	U+256c
+0xcf	U+2567
+0xd0	U+2568
+0xd1	U+2564
+0xd2	U+2565
+0xd3	U+2559
+0xd4	U+2558
+0xd5	U+2552
+0xd6	U+2553
+0xd7	U+256b
+0xd8	U+256a
+0xd9	U+2518
+0xda	U+250c
+0xdb	U+2588
+0xdc	U+2584
+0xdd	U+258c
+0xde	U+2590
+0xdf	U+2580
+#
+# Greek letters and mathematical symbols
+#
+0xe0	U+03b1
+0xe1	U+03b2 U+00df
+0xe2	U+0393
+0xe3	U+03c0
+0xe4	U+03a3
+0xe5	U+03c3
+0xe6	U+00b5 U+03bc
+0xe7	U+03c4
+0xe8	U+03a6 U+00d8
+0xe9	U+0398
+0xea	U+03a9 U+2126
+0xeb	U+03b4 U+00f0
+0xec	U+221e
+0xed	U+03c6 U+00f8
+0xee	U+03b5 U+2208
+0xef	U+2229
+0xf0	U+2261
+0xf1	U+00b1
+0xf2	U+2265
+0xf3	U+2264
+0xf4	U+2320
+0xf5	U+2321
+0xf6	U+00f7
+0xf7	U+2248
+0xf8	U+00b0
+0xf9	U+2219
+0xfa	U+00b7
+0xfb	U+221a
+0xfc	U+207f
+0xfd	U+00b2
+#
+# Square bullet, non-spacing blank
+# Mapping U+fffd to the square bullet means it is the substitution
+# character
+# 
+0xfe	U+25a0 U+fffd
+0xff	U+00a0
diff --git a/drivers/tty/vt/defkeymap.c_shipped b/drivers/tty/vt/defkeymap.c_shipped
new file mode 100644
index 0000000..d2208dfe
--- /dev/null
+++ b/drivers/tty/vt/defkeymap.c_shipped
@@ -0,0 +1,262 @@
+/* Do not edit this file! It was automatically generated by   */
+/*    loadkeys --mktable defkeymap.map > defkeymap.c          */
+
+#include <linux/types.h>
+#include <linux/keyboard.h>
+#include <linux/kd.h>
+
+u_short plain_map[NR_KEYS] = {
+	0xf200,	0xf01b,	0xf031,	0xf032,	0xf033,	0xf034,	0xf035,	0xf036,
+	0xf037,	0xf038,	0xf039,	0xf030,	0xf02d,	0xf03d,	0xf07f,	0xf009,
+	0xfb71,	0xfb77,	0xfb65,	0xfb72,	0xfb74,	0xfb79,	0xfb75,	0xfb69,
+	0xfb6f,	0xfb70,	0xf05b,	0xf05d,	0xf201,	0xf702,	0xfb61,	0xfb73,
+	0xfb64,	0xfb66,	0xfb67,	0xfb68,	0xfb6a,	0xfb6b,	0xfb6c,	0xf03b,
+	0xf027,	0xf060,	0xf700,	0xf05c,	0xfb7a,	0xfb78,	0xfb63,	0xfb76,
+	0xfb62,	0xfb6e,	0xfb6d,	0xf02c,	0xf02e,	0xf02f,	0xf700,	0xf30c,
+	0xf703,	0xf020,	0xf207,	0xf100,	0xf101,	0xf102,	0xf103,	0xf104,
+	0xf105,	0xf106,	0xf107,	0xf108,	0xf109,	0xf208,	0xf209,	0xf307,
+	0xf308,	0xf309,	0xf30b,	0xf304,	0xf305,	0xf306,	0xf30a,	0xf301,
+	0xf302,	0xf303,	0xf300,	0xf310,	0xf206,	0xf200,	0xf03c,	0xf10a,
+	0xf10b,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf01c,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf601,	0xf602,	0xf117,	0xf600,	0xf119,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+u_short shift_map[NR_KEYS] = {
+	0xf200,	0xf01b,	0xf021,	0xf040,	0xf023,	0xf024,	0xf025,	0xf05e,
+	0xf026,	0xf02a,	0xf028,	0xf029,	0xf05f,	0xf02b,	0xf07f,	0xf009,
+	0xfb51,	0xfb57,	0xfb45,	0xfb52,	0xfb54,	0xfb59,	0xfb55,	0xfb49,
+	0xfb4f,	0xfb50,	0xf07b,	0xf07d,	0xf201,	0xf702,	0xfb41,	0xfb53,
+	0xfb44,	0xfb46,	0xfb47,	0xfb48,	0xfb4a,	0xfb4b,	0xfb4c,	0xf03a,
+	0xf022,	0xf07e,	0xf700,	0xf07c,	0xfb5a,	0xfb58,	0xfb43,	0xfb56,
+	0xfb42,	0xfb4e,	0xfb4d,	0xf03c,	0xf03e,	0xf03f,	0xf700,	0xf30c,
+	0xf703,	0xf020,	0xf207,	0xf10a,	0xf10b,	0xf10c,	0xf10d,	0xf10e,
+	0xf10f,	0xf110,	0xf111,	0xf112,	0xf113,	0xf213,	0xf203,	0xf307,
+	0xf308,	0xf309,	0xf30b,	0xf304,	0xf305,	0xf306,	0xf30a,	0xf301,
+	0xf302,	0xf303,	0xf300,	0xf310,	0xf206,	0xf200,	0xf03e,	0xf10a,
+	0xf10b,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf200,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf20b,	0xf601,	0xf602,	0xf117,	0xf600,	0xf20a,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+u_short altgr_map[NR_KEYS] = {
+	0xf200,	0xf200,	0xf200,	0xf040,	0xf200,	0xf024,	0xf200,	0xf200,
+	0xf07b,	0xf05b,	0xf05d,	0xf07d,	0xf05c,	0xf200,	0xf200,	0xf200,
+	0xfb71,	0xfb77,	0xf918,	0xfb72,	0xfb74,	0xfb79,	0xfb75,	0xfb69,
+	0xfb6f,	0xfb70,	0xf200,	0xf07e,	0xf201,	0xf702,	0xf914,	0xfb73,
+	0xf917,	0xf919,	0xfb67,	0xfb68,	0xfb6a,	0xfb6b,	0xfb6c,	0xf200,
+	0xf200,	0xf200,	0xf700,	0xf200,	0xfb7a,	0xfb78,	0xf916,	0xfb76,
+	0xf915,	0xfb6e,	0xfb6d,	0xf200,	0xf200,	0xf200,	0xf700,	0xf30c,
+	0xf703,	0xf200,	0xf207,	0xf50c,	0xf50d,	0xf50e,	0xf50f,	0xf510,
+	0xf511,	0xf512,	0xf513,	0xf514,	0xf515,	0xf208,	0xf202,	0xf911,
+	0xf912,	0xf913,	0xf30b,	0xf90e,	0xf90f,	0xf910,	0xf30a,	0xf90b,
+	0xf90c,	0xf90d,	0xf90a,	0xf310,	0xf206,	0xf200,	0xf07c,	0xf516,
+	0xf517,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf200,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf601,	0xf602,	0xf117,	0xf600,	0xf119,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+u_short ctrl_map[NR_KEYS] = {
+	0xf200,	0xf200,	0xf200,	0xf000,	0xf01b,	0xf01c,	0xf01d,	0xf01e,
+	0xf01f,	0xf07f,	0xf200,	0xf200,	0xf01f,	0xf200,	0xf008,	0xf200,
+	0xf011,	0xf017,	0xf005,	0xf012,	0xf014,	0xf019,	0xf015,	0xf009,
+	0xf00f,	0xf010,	0xf01b,	0xf01d,	0xf201,	0xf702,	0xf001,	0xf013,
+	0xf004,	0xf006,	0xf007,	0xf008,	0xf00a,	0xf00b,	0xf00c,	0xf200,
+	0xf007,	0xf000,	0xf700,	0xf01c,	0xf01a,	0xf018,	0xf003,	0xf016,
+	0xf002,	0xf00e,	0xf00d,	0xf200,	0xf20e,	0xf07f,	0xf700,	0xf30c,
+	0xf703,	0xf000,	0xf207,	0xf100,	0xf101,	0xf102,	0xf103,	0xf104,
+	0xf105,	0xf106,	0xf107,	0xf108,	0xf109,	0xf208,	0xf204,	0xf307,
+	0xf308,	0xf309,	0xf30b,	0xf304,	0xf305,	0xf306,	0xf30a,	0xf301,
+	0xf302,	0xf303,	0xf300,	0xf310,	0xf206,	0xf200,	0xf200,	0xf10a,
+	0xf10b,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf01c,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf601,	0xf602,	0xf117,	0xf600,	0xf119,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+u_short shift_ctrl_map[NR_KEYS] = {
+	0xf200,	0xf200,	0xf200,	0xf000,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf01f,	0xf200,	0xf200,	0xf200,
+	0xf011,	0xf017,	0xf005,	0xf012,	0xf014,	0xf019,	0xf015,	0xf009,
+	0xf00f,	0xf010,	0xf200,	0xf200,	0xf201,	0xf702,	0xf001,	0xf013,
+	0xf004,	0xf006,	0xf007,	0xf008,	0xf00a,	0xf00b,	0xf00c,	0xf200,
+	0xf200,	0xf200,	0xf700,	0xf200,	0xf01a,	0xf018,	0xf003,	0xf016,
+	0xf002,	0xf00e,	0xf00d,	0xf200,	0xf200,	0xf200,	0xf700,	0xf30c,
+	0xf703,	0xf200,	0xf207,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf208,	0xf200,	0xf307,
+	0xf308,	0xf309,	0xf30b,	0xf304,	0xf305,	0xf306,	0xf30a,	0xf301,
+	0xf302,	0xf303,	0xf300,	0xf310,	0xf206,	0xf200,	0xf200,	0xf200,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf200,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf601,	0xf602,	0xf117,	0xf600,	0xf119,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+u_short alt_map[NR_KEYS] = {
+	0xf200,	0xf81b,	0xf831,	0xf832,	0xf833,	0xf834,	0xf835,	0xf836,
+	0xf837,	0xf838,	0xf839,	0xf830,	0xf82d,	0xf83d,	0xf87f,	0xf809,
+	0xf871,	0xf877,	0xf865,	0xf872,	0xf874,	0xf879,	0xf875,	0xf869,
+	0xf86f,	0xf870,	0xf85b,	0xf85d,	0xf80d,	0xf702,	0xf861,	0xf873,
+	0xf864,	0xf866,	0xf867,	0xf868,	0xf86a,	0xf86b,	0xf86c,	0xf83b,
+	0xf827,	0xf860,	0xf700,	0xf85c,	0xf87a,	0xf878,	0xf863,	0xf876,
+	0xf862,	0xf86e,	0xf86d,	0xf82c,	0xf82e,	0xf82f,	0xf700,	0xf30c,
+	0xf703,	0xf820,	0xf207,	0xf500,	0xf501,	0xf502,	0xf503,	0xf504,
+	0xf505,	0xf506,	0xf507,	0xf508,	0xf509,	0xf208,	0xf209,	0xf907,
+	0xf908,	0xf909,	0xf30b,	0xf904,	0xf905,	0xf906,	0xf30a,	0xf901,
+	0xf902,	0xf903,	0xf900,	0xf310,	0xf206,	0xf200,	0xf83c,	0xf50a,
+	0xf50b,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf01c,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf210,	0xf211,	0xf117,	0xf600,	0xf119,	0xf115,	0xf116,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+u_short ctrl_alt_map[NR_KEYS] = {
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf811,	0xf817,	0xf805,	0xf812,	0xf814,	0xf819,	0xf815,	0xf809,
+	0xf80f,	0xf810,	0xf200,	0xf200,	0xf201,	0xf702,	0xf801,	0xf813,
+	0xf804,	0xf806,	0xf807,	0xf808,	0xf80a,	0xf80b,	0xf80c,	0xf200,
+	0xf200,	0xf200,	0xf700,	0xf200,	0xf81a,	0xf818,	0xf803,	0xf816,
+	0xf802,	0xf80e,	0xf80d,	0xf200,	0xf200,	0xf200,	0xf700,	0xf30c,
+	0xf703,	0xf200,	0xf207,	0xf500,	0xf501,	0xf502,	0xf503,	0xf504,
+	0xf505,	0xf506,	0xf507,	0xf508,	0xf509,	0xf208,	0xf200,	0xf307,
+	0xf308,	0xf309,	0xf30b,	0xf304,	0xf305,	0xf306,	0xf30a,	0xf301,
+	0xf302,	0xf303,	0xf300,	0xf20c,	0xf206,	0xf200,	0xf200,	0xf50a,
+	0xf50b,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+	0xf30e,	0xf702,	0xf30d,	0xf200,	0xf701,	0xf205,	0xf114,	0xf603,
+	0xf118,	0xf601,	0xf602,	0xf117,	0xf600,	0xf119,	0xf115,	0xf20c,
+	0xf11a,	0xf10c,	0xf10d,	0xf11b,	0xf11c,	0xf110,	0xf311,	0xf11d,
+	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,	0xf200,
+};
+
+ushort *key_maps[MAX_NR_KEYMAPS] = {
+	plain_map, shift_map, altgr_map, NULL,
+	ctrl_map, shift_ctrl_map, NULL, NULL,
+	alt_map, NULL, NULL, NULL,
+	ctrl_alt_map, NULL
+};
+
+unsigned int keymap_count = 7;
+
+/*
+ * Philosophy: most people do not define more strings, but they who do
+ * often want quite a lot of string space. So, we statically allocate
+ * the default and allocate dynamically in chunks of 512 bytes.
+ */
+
+char func_buf[] = {
+	'\033', '[', '[', 'A', 0, 
+	'\033', '[', '[', 'B', 0, 
+	'\033', '[', '[', 'C', 0, 
+	'\033', '[', '[', 'D', 0, 
+	'\033', '[', '[', 'E', 0, 
+	'\033', '[', '1', '7', '~', 0, 
+	'\033', '[', '1', '8', '~', 0, 
+	'\033', '[', '1', '9', '~', 0, 
+	'\033', '[', '2', '0', '~', 0, 
+	'\033', '[', '2', '1', '~', 0, 
+	'\033', '[', '2', '3', '~', 0, 
+	'\033', '[', '2', '4', '~', 0, 
+	'\033', '[', '2', '5', '~', 0, 
+	'\033', '[', '2', '6', '~', 0, 
+	'\033', '[', '2', '8', '~', 0, 
+	'\033', '[', '2', '9', '~', 0, 
+	'\033', '[', '3', '1', '~', 0, 
+	'\033', '[', '3', '2', '~', 0, 
+	'\033', '[', '3', '3', '~', 0, 
+	'\033', '[', '3', '4', '~', 0, 
+	'\033', '[', '1', '~', 0, 
+	'\033', '[', '2', '~', 0, 
+	'\033', '[', '3', '~', 0, 
+	'\033', '[', '4', '~', 0, 
+	'\033', '[', '5', '~', 0, 
+	'\033', '[', '6', '~', 0, 
+	'\033', '[', 'M', 0, 
+	'\033', '[', 'P', 0, 
+};
+
+char *funcbufptr = func_buf;
+int funcbufsize = sizeof(func_buf);
+int funcbufleft = 0;          /* space left */
+
+char *func_table[MAX_NR_FUNC] = {
+	func_buf + 0,
+	func_buf + 5,
+	func_buf + 10,
+	func_buf + 15,
+	func_buf + 20,
+	func_buf + 25,
+	func_buf + 31,
+	func_buf + 37,
+	func_buf + 43,
+	func_buf + 49,
+	func_buf + 55,
+	func_buf + 61,
+	func_buf + 67,
+	func_buf + 73,
+	func_buf + 79,
+	func_buf + 85,
+	func_buf + 91,
+	func_buf + 97,
+	func_buf + 103,
+	func_buf + 109,
+	func_buf + 115,
+	func_buf + 120,
+	func_buf + 125,
+	func_buf + 130,
+	func_buf + 135,
+	func_buf + 140,
+	func_buf + 145,
+	NULL,
+	NULL,
+	func_buf + 149,
+	NULL,
+};
+
+struct kbdiacruc accent_table[MAX_DIACR] = {
+	{'`', 'A', 0300},	{'`', 'a', 0340},
+	{'\'', 'A', 0301},	{'\'', 'a', 0341},
+	{'^', 'A', 0302},	{'^', 'a', 0342},
+	{'~', 'A', 0303},	{'~', 'a', 0343},
+	{'"', 'A', 0304},	{'"', 'a', 0344},
+	{'O', 'A', 0305},	{'o', 'a', 0345},
+	{'0', 'A', 0305},	{'0', 'a', 0345},
+	{'A', 'A', 0305},	{'a', 'a', 0345},
+	{'A', 'E', 0306},	{'a', 'e', 0346},
+	{',', 'C', 0307},	{',', 'c', 0347},
+	{'`', 'E', 0310},	{'`', 'e', 0350},
+	{'\'', 'E', 0311},	{'\'', 'e', 0351},
+	{'^', 'E', 0312},	{'^', 'e', 0352},
+	{'"', 'E', 0313},	{'"', 'e', 0353},
+	{'`', 'I', 0314},	{'`', 'i', 0354},
+	{'\'', 'I', 0315},	{'\'', 'i', 0355},
+	{'^', 'I', 0316},	{'^', 'i', 0356},
+	{'"', 'I', 0317},	{'"', 'i', 0357},
+	{'-', 'D', 0320},	{'-', 'd', 0360},
+	{'~', 'N', 0321},	{'~', 'n', 0361},
+	{'`', 'O', 0322},	{'`', 'o', 0362},
+	{'\'', 'O', 0323},	{'\'', 'o', 0363},
+	{'^', 'O', 0324},	{'^', 'o', 0364},
+	{'~', 'O', 0325},	{'~', 'o', 0365},
+	{'"', 'O', 0326},	{'"', 'o', 0366},
+	{'/', 'O', 0330},	{'/', 'o', 0370},
+	{'`', 'U', 0331},	{'`', 'u', 0371},
+	{'\'', 'U', 0332},	{'\'', 'u', 0372},
+	{'^', 'U', 0333},	{'^', 'u', 0373},
+	{'"', 'U', 0334},	{'"', 'u', 0374},
+	{'\'', 'Y', 0335},	{'\'', 'y', 0375},
+	{'T', 'H', 0336},	{'t', 'h', 0376},
+	{'s', 's', 0337},	{'"', 'y', 0377},
+	{'s', 'z', 0337},	{'i', 'j', 0377},
+};
+
+unsigned int accent_table_size = 68;
diff --git a/drivers/tty/vt/defkeymap.map b/drivers/tty/vt/defkeymap.map
new file mode 100644
index 0000000..50b30ca
--- /dev/null
+++ b/drivers/tty/vt/defkeymap.map
@@ -0,0 +1,357 @@
+# Default kernel keymap. This uses 7 modifier combinations.
+keymaps 0-2,4-5,8,12
+# Change the above line into
+#	keymaps 0-2,4-6,8,12
+# in case you want the entries
+#	altgr   control keycode  83 = Boot            
+#	altgr   control keycode 111 = Boot            
+# below.
+#
+# In fact AltGr is used very little, and one more keymap can
+# be saved by mapping AltGr to Alt (and adapting a few entries):
+# keycode 100 = Alt
+#
+keycode   1 = Escape           Escape          
+	alt     keycode   1 = Meta_Escape     
+keycode   2 = one              exclam          
+	alt     keycode   2 = Meta_one        
+keycode   3 = two              at               at              
+	control	keycode   3 = nul             
+	shift	control	keycode   3 = nul             
+	alt	keycode   3 = Meta_two        
+keycode   4 = three            numbersign      
+	control keycode   4 = Escape          
+	alt     keycode   4 = Meta_three      
+keycode   5 = four             dollar           dollar          
+	control keycode   5 = Control_backslash
+	alt     keycode   5 = Meta_four       
+keycode   6 = five             percent         
+	control keycode   6 = Control_bracketright
+	alt     keycode   6 = Meta_five       
+keycode   7 = six              asciicircum     
+	control keycode   7 = Control_asciicircum
+	alt     keycode   7 = Meta_six        
+keycode   8 = seven            ampersand        braceleft       
+	control keycode   8 = Control_underscore
+	alt     keycode   8 = Meta_seven      
+keycode   9 = eight            asterisk         bracketleft     
+	control keycode   9 = Delete          
+	alt     keycode   9 = Meta_eight      
+keycode  10 = nine             parenleft        bracketright    
+	alt     keycode  10 = Meta_nine       
+keycode  11 = zero             parenright       braceright      
+	alt     keycode  11 = Meta_zero       
+keycode  12 = minus            underscore       backslash       
+	control	keycode  12 = Control_underscore
+	shift	control	keycode  12 = Control_underscore
+	alt	keycode  12 = Meta_minus      
+keycode  13 = equal            plus            
+	alt     keycode  13 = Meta_equal      
+keycode  14 = Delete           Delete          
+	control keycode  14 = BackSpace
+	alt     keycode  14 = Meta_Delete     
+keycode  15 = Tab              Tab             
+	alt     keycode  15 = Meta_Tab        
+keycode  16 = q               
+keycode  17 = w               
+keycode  18 = e
+	altgr   keycode  18 = Hex_E   
+keycode  19 = r               
+keycode  20 = t               
+keycode  21 = y               
+keycode  22 = u               
+keycode  23 = i               
+keycode  24 = o               
+keycode  25 = p               
+keycode  26 = bracketleft      braceleft       
+	control keycode  26 = Escape          
+	alt     keycode  26 = Meta_bracketleft
+keycode  27 = bracketright     braceright       asciitilde      
+	control keycode  27 = Control_bracketright
+	alt     keycode  27 = Meta_bracketright
+keycode  28 = Return          
+	alt     keycode  28 = Meta_Control_m  
+keycode  29 = Control         
+keycode  30 = a
+	altgr   keycode  30 = Hex_A
+keycode  31 = s               
+keycode  32 = d
+	altgr   keycode  32 = Hex_D   
+keycode  33 = f
+	altgr   keycode  33 = Hex_F               
+keycode  34 = g               
+keycode  35 = h               
+keycode  36 = j               
+keycode  37 = k               
+keycode  38 = l               
+keycode  39 = semicolon        colon           
+	alt     keycode  39 = Meta_semicolon  
+keycode  40 = apostrophe       quotedbl        
+	control keycode  40 = Control_g       
+	alt     keycode  40 = Meta_apostrophe 
+keycode  41 = grave            asciitilde      
+	control keycode  41 = nul             
+	alt     keycode  41 = Meta_grave      
+keycode  42 = Shift           
+keycode  43 = backslash        bar             
+	control keycode  43 = Control_backslash
+	alt     keycode  43 = Meta_backslash  
+keycode  44 = z               
+keycode  45 = x               
+keycode  46 = c
+	altgr   keycode  46 = Hex_C   
+keycode  47 = v               
+keycode  48 = b
+	altgr   keycode  48 = Hex_B
+keycode  49 = n               
+keycode  50 = m               
+keycode  51 = comma            less            
+	alt     keycode  51 = Meta_comma      
+keycode  52 = period           greater         
+	control keycode  52 = Compose         
+	alt     keycode  52 = Meta_period     
+keycode  53 = slash            question        
+	control keycode  53 = Delete          
+	alt     keycode  53 = Meta_slash      
+keycode  54 = Shift           
+keycode  55 = KP_Multiply     
+keycode  56 = Alt             
+keycode  57 = space            space           
+	control keycode  57 = nul             
+	alt     keycode  57 = Meta_space      
+keycode  58 = Caps_Lock       
+keycode  59 = F1               F11              Console_13      
+	control keycode  59 = F1              
+	alt     keycode  59 = Console_1       
+	control alt     keycode  59 = Console_1       
+keycode  60 = F2               F12              Console_14      
+	control keycode  60 = F2              
+	alt     keycode  60 = Console_2       
+	control alt     keycode  60 = Console_2       
+keycode  61 = F3               F13              Console_15      
+	control keycode  61 = F3              
+	alt     keycode  61 = Console_3       
+	control alt     keycode  61 = Console_3       
+keycode  62 = F4               F14              Console_16      
+	control keycode  62 = F4              
+	alt     keycode  62 = Console_4       
+	control alt     keycode  62 = Console_4       
+keycode  63 = F5               F15              Console_17      
+	control keycode  63 = F5              
+	alt     keycode  63 = Console_5       
+	control alt     keycode  63 = Console_5       
+keycode  64 = F6               F16              Console_18      
+	control keycode  64 = F6              
+	alt     keycode  64 = Console_6       
+	control alt     keycode  64 = Console_6       
+keycode  65 = F7               F17              Console_19      
+	control keycode  65 = F7              
+	alt     keycode  65 = Console_7       
+	control alt     keycode  65 = Console_7       
+keycode  66 = F8               F18              Console_20      
+	control keycode  66 = F8              
+	alt     keycode  66 = Console_8       
+	control alt     keycode  66 = Console_8       
+keycode  67 = F9               F19              Console_21      
+	control keycode  67 = F9              
+	alt     keycode  67 = Console_9       
+	control alt     keycode  67 = Console_9       
+keycode  68 = F10              F20              Console_22      
+	control keycode  68 = F10             
+	alt     keycode  68 = Console_10      
+	control alt     keycode  68 = Console_10      
+keycode  69 = Num_Lock
+	shift   keycode  69 = Bare_Num_Lock
+keycode  70 = Scroll_Lock      Show_Memory      Show_Registers  
+	control keycode  70 = Show_State      
+	alt     keycode  70 = Scroll_Lock     
+keycode  71 = KP_7            
+	alt     keycode  71 = Ascii_7         
+	altgr   keycode  71 = Hex_7         
+keycode  72 = KP_8            
+	alt     keycode  72 = Ascii_8         
+	altgr   keycode  72 = Hex_8         
+keycode  73 = KP_9            
+	alt     keycode  73 = Ascii_9         
+	altgr   keycode  73 = Hex_9         
+keycode  74 = KP_Subtract     
+keycode  75 = KP_4            
+	alt     keycode  75 = Ascii_4         
+	altgr   keycode  75 = Hex_4         
+keycode  76 = KP_5            
+	alt     keycode  76 = Ascii_5         
+	altgr   keycode  76 = Hex_5         
+keycode  77 = KP_6            
+	alt     keycode  77 = Ascii_6         
+	altgr   keycode  77 = Hex_6         
+keycode  78 = KP_Add          
+keycode  79 = KP_1            
+	alt     keycode  79 = Ascii_1         
+	altgr   keycode  79 = Hex_1         
+keycode  80 = KP_2            
+	alt     keycode  80 = Ascii_2         
+	altgr   keycode  80 = Hex_2         
+keycode  81 = KP_3            
+	alt     keycode  81 = Ascii_3         
+	altgr   keycode  81 = Hex_3         
+keycode  82 = KP_0            
+	alt     keycode  82 = Ascii_0         
+	altgr   keycode  82 = Hex_0         
+keycode  83 = KP_Period       
+#	altgr   control keycode  83 = Boot            
+	control alt     keycode  83 = Boot            
+keycode  84 = Last_Console    
+keycode  85 =
+keycode  86 = less             greater          bar             
+	alt     keycode  86 = Meta_less       
+keycode  87 = F11              F11              Console_23      
+	control keycode  87 = F11             
+	alt     keycode  87 = Console_11      
+	control alt     keycode  87 = Console_11      
+keycode  88 = F12              F12              Console_24      
+	control keycode  88 = F12             
+	alt     keycode  88 = Console_12      
+	control alt     keycode  88 = Console_12      
+keycode  89 =
+keycode  90 =
+keycode  91 =
+keycode  92 =
+keycode  93 =
+keycode  94 =
+keycode  95 =
+keycode  96 = KP_Enter        
+keycode  97 = Control         
+keycode  98 = KP_Divide       
+keycode  99 = Control_backslash
+	control keycode  99 = Control_backslash
+	alt     keycode  99 = Control_backslash
+keycode 100 = AltGr           
+keycode 101 = Break           
+keycode 102 = Find            
+keycode 103 = Up              
+keycode 104 = Prior           
+	shift   keycode 104 = Scroll_Backward 
+keycode 105 = Left            
+	alt     keycode 105 = Decr_Console
+keycode 106 = Right           
+	alt     keycode 106 = Incr_Console
+keycode 107 = Select          
+keycode 108 = Down            
+keycode 109 = Next            
+	shift   keycode 109 = Scroll_Forward  
+keycode 110 = Insert          
+keycode 111 = Remove          
+#	altgr   control keycode 111 = Boot            
+	control alt     keycode 111 = Boot            
+keycode 112 = Macro           
+keycode 113 = F13             
+keycode 114 = F14             
+keycode 115 = Help            
+keycode 116 = Do              
+keycode 117 = F17             
+keycode 118 = KP_MinPlus      
+keycode 119 = Pause           
+keycode 120 =
+keycode 121 =
+keycode 122 =
+keycode 123 =
+keycode 124 =
+keycode 125 =
+keycode 126 =
+keycode 127 =
+string F1 = "\033[[A"
+string F2 = "\033[[B"
+string F3 = "\033[[C"
+string F4 = "\033[[D"
+string F5 = "\033[[E"
+string F6 = "\033[17~"
+string F7 = "\033[18~"
+string F8 = "\033[19~"
+string F9 = "\033[20~"
+string F10 = "\033[21~"
+string F11 = "\033[23~"
+string F12 = "\033[24~"
+string F13 = "\033[25~"
+string F14 = "\033[26~"
+string F15 = "\033[28~"
+string F16 = "\033[29~"
+string F17 = "\033[31~"
+string F18 = "\033[32~"
+string F19 = "\033[33~"
+string F20 = "\033[34~"
+string Find = "\033[1~"
+string Insert = "\033[2~"
+string Remove = "\033[3~"
+string Select = "\033[4~"
+string Prior = "\033[5~"
+string Next = "\033[6~"
+string Macro = "\033[M"
+string Pause = "\033[P"
+compose '`' 'A' to 'À'
+compose '`' 'a' to 'à'
+compose '\'' 'A' to 'Á'
+compose '\'' 'a' to 'á'
+compose '^' 'A' to 'Â'
+compose '^' 'a' to 'â'
+compose '~' 'A' to 'Ã'
+compose '~' 'a' to 'ã'
+compose '"' 'A' to 'Ä'
+compose '"' 'a' to 'ä'
+compose 'O' 'A' to 'Å'
+compose 'o' 'a' to 'å'
+compose '0' 'A' to 'Å'
+compose '0' 'a' to 'å'
+compose 'A' 'A' to 'Å'
+compose 'a' 'a' to 'å'
+compose 'A' 'E' to 'Æ'
+compose 'a' 'e' to 'æ'
+compose ',' 'C' to 'Ç'
+compose ',' 'c' to 'ç'
+compose '`' 'E' to 'È'
+compose '`' 'e' to 'è'
+compose '\'' 'E' to 'É'
+compose '\'' 'e' to 'é'
+compose '^' 'E' to 'Ê'
+compose '^' 'e' to 'ê'
+compose '"' 'E' to 'Ë'
+compose '"' 'e' to 'ë'
+compose '`' 'I' to 'Ì'
+compose '`' 'i' to 'ì'
+compose '\'' 'I' to 'Í'
+compose '\'' 'i' to 'í'
+compose '^' 'I' to 'Î'
+compose '^' 'i' to 'î'
+compose '"' 'I' to 'Ï'
+compose '"' 'i' to 'ï'
+compose '-' 'D' to 'Ð'
+compose '-' 'd' to 'ð'
+compose '~' 'N' to 'Ñ'
+compose '~' 'n' to 'ñ'
+compose '`' 'O' to 'Ò'
+compose '`' 'o' to 'ò'
+compose '\'' 'O' to 'Ó'
+compose '\'' 'o' to 'ó'
+compose '^' 'O' to 'Ô'
+compose '^' 'o' to 'ô'
+compose '~' 'O' to 'Õ'
+compose '~' 'o' to 'õ'
+compose '"' 'O' to 'Ö'
+compose '"' 'o' to 'ö'
+compose '/' 'O' to 'Ø'
+compose '/' 'o' to 'ø'
+compose '`' 'U' to 'Ù'
+compose '`' 'u' to 'ù'
+compose '\'' 'U' to 'Ú'
+compose '\'' 'u' to 'ú'
+compose '^' 'U' to 'Û'
+compose '^' 'u' to 'û'
+compose '"' 'U' to 'Ü'
+compose '"' 'u' to 'ü'
+compose '\'' 'Y' to 'Ý'
+compose '\'' 'y' to 'ý'
+compose 'T' 'H' to 'Þ'
+compose 't' 'h' to 'þ'
+compose 's' 's' to 'ß'
+compose '"' 'y' to 'ÿ'
+compose 's' 'z' to 'ß'
+compose 'i' 'j' to 'ÿ'
diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c
new file mode 100644
index 0000000..e95d787
--- /dev/null
+++ b/drivers/tty/vt/keyboard.c
@@ -0,0 +1,1454 @@
+/*
+ * linux/drivers/char/keyboard.c
+ *
+ * Written for linux by Johan Myreen as a translation from
+ * the assembly version by Linus (with diacriticals added)
+ *
+ * Some additional features added by Christoph Niemann (ChN), March 1993
+ *
+ * Loadable keymaps by Risto Kankkunen, May 1993
+ *
+ * Diacriticals redone & other small changes, aeb@cwi.nl, June 1993
+ * Added decr/incr_console, dynamic keymaps, Unicode support,
+ * dynamic function/string keys, led setting,  Sept 1994
+ * `Sticky' modifier keys, 951006.
+ *
+ * 11-11-96: SAK should now work in the raw mode (Martin Mares)
+ *
+ * Modified to provide 'generic' keyboard support by Hamish Macdonald
+ * Merge with the m68k keyboard driver and split-off of the PC low-level
+ * parts by Geert Uytterhoeven, May 1997
+ *
+ * 27-05-97: Added support for the Magic SysRq Key (Martin Mares)
+ * 30-07-98: Dead keys redone, aeb@cwi.nl.
+ * 21-08-02: Converted to input API, major cleanup. (Vojtech Pavlik)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/consolemap.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/irq.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/kbd_diacr.h>
+#include <linux/vt_kern.h>
+#include <linux/input.h>
+#include <linux/reboot.h>
+#include <linux/notifier.h>
+#include <linux/jiffies.h>
+
+extern void ctrl_alt_del(void);
+
+/*
+ * Exported functions/variables
+ */
+
+#define KBD_DEFMODE ((1 << VC_REPEAT) | (1 << VC_META))
+
+/*
+ * Some laptops take the 789uiojklm,. keys as number pad when NumLock is on.
+ * This seems a good reason to start with NumLock off. On HIL keyboards
+ * of PARISC machines however there is no NumLock key and everyone expects the keypad
+ * to be used for numbers.
+ */
+
+#if defined(CONFIG_PARISC) && (defined(CONFIG_KEYBOARD_HIL) || defined(CONFIG_KEYBOARD_HIL_OLD))
+#define KBD_DEFLEDS (1 << VC_NUMLOCK)
+#else
+#define KBD_DEFLEDS 0
+#endif
+
+#define KBD_DEFLOCK 0
+
+void compute_shiftstate(void);
+
+/*
+ * Handler Tables.
+ */
+
+#define K_HANDLERS\
+	k_self,		k_fn,		k_spec,		k_pad,\
+	k_dead,		k_cons,		k_cur,		k_shift,\
+	k_meta,		k_ascii,	k_lock,		k_lowercase,\
+	k_slock,	k_dead2,	k_brl,		k_ignore
+
+typedef void (k_handler_fn)(struct vc_data *vc, unsigned char value,
+			    char up_flag);
+static k_handler_fn K_HANDLERS;
+static k_handler_fn *k_handler[16] = { K_HANDLERS };
+
+#define FN_HANDLERS\
+	fn_null,	fn_enter,	fn_show_ptregs,	fn_show_mem,\
+	fn_show_state,	fn_send_intr,	fn_lastcons,	fn_caps_toggle,\
+	fn_num,		fn_hold,	fn_scroll_forw,	fn_scroll_back,\
+	fn_boot_it,	fn_caps_on,	fn_compose,	fn_SAK,\
+	fn_dec_console, fn_inc_console, fn_spawn_con,	fn_bare_num
+
+typedef void (fn_handler_fn)(struct vc_data *vc);
+static fn_handler_fn FN_HANDLERS;
+static fn_handler_fn *fn_handler[] = { FN_HANDLERS };
+
+/*
+ * Variables exported for vt_ioctl.c
+ */
+
+/* maximum values each key_handler can handle */
+const int max_vals[] = {
+	255, ARRAY_SIZE(func_table) - 1, ARRAY_SIZE(fn_handler) - 1, NR_PAD - 1,
+	NR_DEAD - 1, 255, 3, NR_SHIFT - 1, 255, NR_ASCII - 1, NR_LOCK - 1,
+	255, NR_LOCK - 1, 255, NR_BRL - 1
+};
+
+const int NR_TYPES = ARRAY_SIZE(max_vals);
+
+struct kbd_struct kbd_table[MAX_NR_CONSOLES];
+EXPORT_SYMBOL_GPL(kbd_table);
+static struct kbd_struct *kbd = kbd_table;
+
+struct vt_spawn_console vt_spawn_con = {
+	.lock = __SPIN_LOCK_UNLOCKED(vt_spawn_con.lock),
+	.pid  = NULL,
+	.sig  = 0,
+};
+
+/*
+ * Variables exported for vt.c
+ */
+
+int shift_state = 0;
+
+/*
+ * Internal Data.
+ */
+
+static struct input_handler kbd_handler;
+static DEFINE_SPINLOCK(kbd_event_lock);
+static unsigned long key_down[BITS_TO_LONGS(KEY_CNT)];	/* keyboard key bitmap */
+static unsigned char shift_down[NR_SHIFT];		/* shift state counters.. */
+static bool dead_key_next;
+static int npadch = -1;					/* -1 or number assembled on pad */
+static unsigned int diacr;
+static char rep;					/* flag telling character repeat */
+
+static unsigned char ledstate = 0xff;			/* undefined */
+static unsigned char ledioctl;
+
+static struct ledptr {
+	unsigned int *addr;
+	unsigned int mask;
+	unsigned char valid:1;
+} ledptrs[3];
+
+/*
+ * Notifier list for console keyboard events
+ */
+static ATOMIC_NOTIFIER_HEAD(keyboard_notifier_list);
+
+int register_keyboard_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&keyboard_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(register_keyboard_notifier);
+
+int unregister_keyboard_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&keyboard_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_keyboard_notifier);
+
+/*
+ * Translation of scancodes to keycodes. We set them on only the first
+ * keyboard in the list that accepts the scancode and keycode.
+ * Explanation for not choosing the first attached keyboard anymore:
+ *  USB keyboards for example have two event devices: one for all "normal"
+ *  keys and one for extra function keys (like "volume up", "make coffee",
+ *  etc.). So this means that scancodes for the extra function keys won't
+ *  be valid for the first event device, but will be for the second.
+ */
+
+struct getset_keycode_data {
+	struct input_keymap_entry ke;
+	int error;
+};
+
+static int getkeycode_helper(struct input_handle *handle, void *data)
+{
+	struct getset_keycode_data *d = data;
+
+	d->error = input_get_keycode(handle->dev, &d->ke);
+
+	return d->error == 0; /* stop as soon as we successfully get one */
+}
+
+int getkeycode(unsigned int scancode)
+{
+	struct getset_keycode_data d = {
+		.ke	= {
+			.flags		= 0,
+			.len		= sizeof(scancode),
+			.keycode	= 0,
+		},
+		.error	= -ENODEV,
+	};
+
+	memcpy(d.ke.scancode, &scancode, sizeof(scancode));
+
+	input_handler_for_each_handle(&kbd_handler, &d, getkeycode_helper);
+
+	return d.error ?: d.ke.keycode;
+}
+
+static int setkeycode_helper(struct input_handle *handle, void *data)
+{
+	struct getset_keycode_data *d = data;
+
+	d->error = input_set_keycode(handle->dev, &d->ke);
+
+	return d->error == 0; /* stop as soon as we successfully set one */
+}
+
+int setkeycode(unsigned int scancode, unsigned int keycode)
+{
+	struct getset_keycode_data d = {
+		.ke	= {
+			.flags		= 0,
+			.len		= sizeof(scancode),
+			.keycode	= keycode,
+		},
+		.error	= -ENODEV,
+	};
+
+	memcpy(d.ke.scancode, &scancode, sizeof(scancode));
+
+	input_handler_for_each_handle(&kbd_handler, &d, setkeycode_helper);
+
+	return d.error;
+}
+
+/*
+ * Making beeps and bells. Note that we prefer beeps to bells, but when
+ * shutting the sound off we do both.
+ */
+
+static int kd_sound_helper(struct input_handle *handle, void *data)
+{
+	unsigned int *hz = data;
+	struct input_dev *dev = handle->dev;
+
+	if (test_bit(EV_SND, dev->evbit)) {
+		if (test_bit(SND_TONE, dev->sndbit)) {
+			input_inject_event(handle, EV_SND, SND_TONE, *hz);
+			if (*hz)
+				return 0;
+		}
+		if (test_bit(SND_BELL, dev->sndbit))
+			input_inject_event(handle, EV_SND, SND_BELL, *hz ? 1 : 0);
+	}
+
+	return 0;
+}
+
+static void kd_nosound(unsigned long ignored)
+{
+	static unsigned int zero;
+
+	input_handler_for_each_handle(&kbd_handler, &zero, kd_sound_helper);
+}
+
+static DEFINE_TIMER(kd_mksound_timer, kd_nosound, 0, 0);
+
+void kd_mksound(unsigned int hz, unsigned int ticks)
+{
+	del_timer_sync(&kd_mksound_timer);
+
+	input_handler_for_each_handle(&kbd_handler, &hz, kd_sound_helper);
+
+	if (hz && ticks)
+		mod_timer(&kd_mksound_timer, jiffies + ticks);
+}
+EXPORT_SYMBOL(kd_mksound);
+
+/*
+ * Setting the keyboard rate.
+ */
+
+static int kbd_rate_helper(struct input_handle *handle, void *data)
+{
+	struct input_dev *dev = handle->dev;
+	struct kbd_repeat *rep = data;
+
+	if (test_bit(EV_REP, dev->evbit)) {
+
+		if (rep[0].delay > 0)
+			input_inject_event(handle,
+					   EV_REP, REP_DELAY, rep[0].delay);
+		if (rep[0].period > 0)
+			input_inject_event(handle,
+					   EV_REP, REP_PERIOD, rep[0].period);
+
+		rep[1].delay = dev->rep[REP_DELAY];
+		rep[1].period = dev->rep[REP_PERIOD];
+	}
+
+	return 0;
+}
+
+int kbd_rate(struct kbd_repeat *rep)
+{
+	struct kbd_repeat data[2] = { *rep };
+
+	input_handler_for_each_handle(&kbd_handler, data, kbd_rate_helper);
+	*rep = data[1];	/* Copy currently used settings */
+
+	return 0;
+}
+
+/*
+ * Helper Functions.
+ */
+static void put_queue(struct vc_data *vc, int ch)
+{
+	struct tty_struct *tty = vc->port.tty;
+
+	if (tty) {
+		tty_insert_flip_char(tty, ch, 0);
+		con_schedule_flip(tty);
+	}
+}
+
+static void puts_queue(struct vc_data *vc, char *cp)
+{
+	struct tty_struct *tty = vc->port.tty;
+
+	if (!tty)
+		return;
+
+	while (*cp) {
+		tty_insert_flip_char(tty, *cp, 0);
+		cp++;
+	}
+	con_schedule_flip(tty);
+}
+
+static void applkey(struct vc_data *vc, int key, char mode)
+{
+	static char buf[] = { 0x1b, 'O', 0x00, 0x00 };
+
+	buf[1] = (mode ? 'O' : '[');
+	buf[2] = key;
+	puts_queue(vc, buf);
+}
+
+/*
+ * Many other routines do put_queue, but I think either
+ * they produce ASCII, or they produce some user-assigned
+ * string, and in both cases we might assume that it is
+ * in utf-8 already.
+ */
+static void to_utf8(struct vc_data *vc, uint c)
+{
+	if (c < 0x80)
+		/*  0******* */
+		put_queue(vc, c);
+	else if (c < 0x800) {
+		/* 110***** 10****** */
+		put_queue(vc, 0xc0 | (c >> 6));
+		put_queue(vc, 0x80 | (c & 0x3f));
+	} else if (c < 0x10000) {
+		if (c >= 0xD800 && c < 0xE000)
+			return;
+		if (c == 0xFFFF)
+			return;
+		/* 1110**** 10****** 10****** */
+		put_queue(vc, 0xe0 | (c >> 12));
+		put_queue(vc, 0x80 | ((c >> 6) & 0x3f));
+		put_queue(vc, 0x80 | (c & 0x3f));
+	} else if (c < 0x110000) {
+		/* 11110*** 10****** 10****** 10****** */
+		put_queue(vc, 0xf0 | (c >> 18));
+		put_queue(vc, 0x80 | ((c >> 12) & 0x3f));
+		put_queue(vc, 0x80 | ((c >> 6) & 0x3f));
+		put_queue(vc, 0x80 | (c & 0x3f));
+	}
+}
+
+/*
+ * Called after returning from RAW mode or when changing consoles - recompute
+ * shift_down[] and shift_state from key_down[] maybe called when keymap is
+ * undefined, so that shiftkey release is seen
+ */
+void compute_shiftstate(void)
+{
+	unsigned int i, j, k, sym, val;
+
+	shift_state = 0;
+	memset(shift_down, 0, sizeof(shift_down));
+
+	for (i = 0; i < ARRAY_SIZE(key_down); i++) {
+
+		if (!key_down[i])
+			continue;
+
+		k = i * BITS_PER_LONG;
+
+		for (j = 0; j < BITS_PER_LONG; j++, k++) {
+
+			if (!test_bit(k, key_down))
+				continue;
+
+			sym = U(key_maps[0][k]);
+			if (KTYP(sym) != KT_SHIFT && KTYP(sym) != KT_SLOCK)
+				continue;
+
+			val = KVAL(sym);
+			if (val == KVAL(K_CAPSSHIFT))
+				val = KVAL(K_SHIFT);
+
+			shift_down[val]++;
+			shift_state |= (1 << val);
+		}
+	}
+}
+
+/*
+ * We have a combining character DIACR here, followed by the character CH.
+ * If the combination occurs in the table, return the corresponding value.
+ * Otherwise, if CH is a space or equals DIACR, return DIACR.
+ * Otherwise, conclude that DIACR was not combining after all,
+ * queue it and return CH.
+ */
+static unsigned int handle_diacr(struct vc_data *vc, unsigned int ch)
+{
+	unsigned int d = diacr;
+	unsigned int i;
+
+	diacr = 0;
+
+	if ((d & ~0xff) == BRL_UC_ROW) {
+		if ((ch & ~0xff) == BRL_UC_ROW)
+			return d | ch;
+	} else {
+		for (i = 0; i < accent_table_size; i++)
+			if (accent_table[i].diacr == d && accent_table[i].base == ch)
+				return accent_table[i].result;
+	}
+
+	if (ch == ' ' || ch == (BRL_UC_ROW|0) || ch == d)
+		return d;
+
+	if (kbd->kbdmode == VC_UNICODE)
+		to_utf8(vc, d);
+	else {
+		int c = conv_uni_to_8bit(d);
+		if (c != -1)
+			put_queue(vc, c);
+	}
+
+	return ch;
+}
+
+/*
+ * Special function handlers
+ */
+static void fn_enter(struct vc_data *vc)
+{
+	if (diacr) {
+		if (kbd->kbdmode == VC_UNICODE)
+			to_utf8(vc, diacr);
+		else {
+			int c = conv_uni_to_8bit(diacr);
+			if (c != -1)
+				put_queue(vc, c);
+		}
+		diacr = 0;
+	}
+
+	put_queue(vc, 13);
+	if (vc_kbd_mode(kbd, VC_CRLF))
+		put_queue(vc, 10);
+}
+
+static void fn_caps_toggle(struct vc_data *vc)
+{
+	if (rep)
+		return;
+
+	chg_vc_kbd_led(kbd, VC_CAPSLOCK);
+}
+
+static void fn_caps_on(struct vc_data *vc)
+{
+	if (rep)
+		return;
+
+	set_vc_kbd_led(kbd, VC_CAPSLOCK);
+}
+
+static void fn_show_ptregs(struct vc_data *vc)
+{
+	struct pt_regs *regs = get_irq_regs();
+
+	if (regs)
+		show_regs(regs);
+}
+
+static void fn_hold(struct vc_data *vc)
+{
+	struct tty_struct *tty = vc->port.tty;
+
+	if (rep || !tty)
+		return;
+
+	/*
+	 * Note: SCROLLOCK will be set (cleared) by stop_tty (start_tty);
+	 * these routines are also activated by ^S/^Q.
+	 * (And SCROLLOCK can also be set by the ioctl KDSKBLED.)
+	 */
+	if (tty->stopped)
+		start_tty(tty);
+	else
+		stop_tty(tty);
+}
+
+static void fn_num(struct vc_data *vc)
+{
+	if (vc_kbd_mode(kbd, VC_APPLIC))
+		applkey(vc, 'P', 1);
+	else
+		fn_bare_num(vc);
+}
+
+/*
+ * Bind this to Shift-NumLock if you work in application keypad mode
+ * but want to be able to change the NumLock flag.
+ * Bind this to NumLock if you prefer that the NumLock key always
+ * changes the NumLock flag.
+ */
+static void fn_bare_num(struct vc_data *vc)
+{
+	if (!rep)
+		chg_vc_kbd_led(kbd, VC_NUMLOCK);
+}
+
+static void fn_lastcons(struct vc_data *vc)
+{
+	/* switch to the last used console, ChN */
+	set_console(last_console);
+}
+
+static void fn_dec_console(struct vc_data *vc)
+{
+	int i, cur = fg_console;
+
+	/* Currently switching?  Queue this next switch relative to that. */
+	if (want_console != -1)
+		cur = want_console;
+
+	for (i = cur - 1; i != cur; i--) {
+		if (i == -1)
+			i = MAX_NR_CONSOLES - 1;
+		if (vc_cons_allocated(i))
+			break;
+	}
+	set_console(i);
+}
+
+static void fn_inc_console(struct vc_data *vc)
+{
+	int i, cur = fg_console;
+
+	/* Currently switching?  Queue this next switch relative to that. */
+	if (want_console != -1)
+		cur = want_console;
+
+	for (i = cur+1; i != cur; i++) {
+		if (i == MAX_NR_CONSOLES)
+			i = 0;
+		if (vc_cons_allocated(i))
+			break;
+	}
+	set_console(i);
+}
+
+static void fn_send_intr(struct vc_data *vc)
+{
+	struct tty_struct *tty = vc->port.tty;
+
+	if (!tty)
+		return;
+	tty_insert_flip_char(tty, 0, TTY_BREAK);
+	con_schedule_flip(tty);
+}
+
+static void fn_scroll_forw(struct vc_data *vc)
+{
+	scrollfront(vc, 0);
+}
+
+static void fn_scroll_back(struct vc_data *vc)
+{
+	scrollback(vc, 0);
+}
+
+static void fn_show_mem(struct vc_data *vc)
+{
+	show_mem();
+}
+
+static void fn_show_state(struct vc_data *vc)
+{
+	show_state();
+}
+
+static void fn_boot_it(struct vc_data *vc)
+{
+	ctrl_alt_del();
+}
+
+static void fn_compose(struct vc_data *vc)
+{
+	dead_key_next = true;
+}
+
+static void fn_spawn_con(struct vc_data *vc)
+{
+	spin_lock(&vt_spawn_con.lock);
+	if (vt_spawn_con.pid)
+		if (kill_pid(vt_spawn_con.pid, vt_spawn_con.sig, 1)) {
+			put_pid(vt_spawn_con.pid);
+			vt_spawn_con.pid = NULL;
+		}
+	spin_unlock(&vt_spawn_con.lock);
+}
+
+static void fn_SAK(struct vc_data *vc)
+{
+	struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
+	schedule_work(SAK_work);
+}
+
+static void fn_null(struct vc_data *vc)
+{
+	compute_shiftstate();
+}
+
+/*
+ * Special key handlers
+ */
+static void k_ignore(struct vc_data *vc, unsigned char value, char up_flag)
+{
+}
+
+static void k_spec(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	if (up_flag)
+		return;
+	if (value >= ARRAY_SIZE(fn_handler))
+		return;
+	if ((kbd->kbdmode == VC_RAW ||
+	     kbd->kbdmode == VC_MEDIUMRAW) &&
+	     value != KVAL(K_SAK))
+		return;		/* SAK is allowed even in raw mode */
+	fn_handler[value](vc);
+}
+
+static void k_lowercase(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	pr_err("k_lowercase was called - impossible\n");
+}
+
+static void k_unicode(struct vc_data *vc, unsigned int value, char up_flag)
+{
+	if (up_flag)
+		return;		/* no action, if this is a key release */
+
+	if (diacr)
+		value = handle_diacr(vc, value);
+
+	if (dead_key_next) {
+		dead_key_next = false;
+		diacr = value;
+		return;
+	}
+	if (kbd->kbdmode == VC_UNICODE)
+		to_utf8(vc, value);
+	else {
+		int c = conv_uni_to_8bit(value);
+		if (c != -1)
+			put_queue(vc, c);
+	}
+}
+
+/*
+ * Handle dead key. Note that we now may have several
+ * dead keys modifying the same character. Very useful
+ * for Vietnamese.
+ */
+static void k_deadunicode(struct vc_data *vc, unsigned int value, char up_flag)
+{
+	if (up_flag)
+		return;
+
+	diacr = (diacr ? handle_diacr(vc, value) : value);
+}
+
+static void k_self(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	k_unicode(vc, conv_8bit_to_uni(value), up_flag);
+}
+
+static void k_dead2(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	k_deadunicode(vc, value, up_flag);
+}
+
+/*
+ * Obsolete - for backwards compatibility only
+ */
+static void k_dead(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	static const unsigned char ret_diacr[NR_DEAD] = {'`', '\'', '^', '~', '"', ',' };
+
+	k_deadunicode(vc, ret_diacr[value], up_flag);
+}
+
+static void k_cons(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	if (up_flag)
+		return;
+
+	set_console(value);
+}
+
+static void k_fn(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	if (up_flag)
+		return;
+
+	if ((unsigned)value < ARRAY_SIZE(func_table)) {
+		if (func_table[value])
+			puts_queue(vc, func_table[value]);
+	} else
+		pr_err("k_fn called with value=%d\n", value);
+}
+
+static void k_cur(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	static const char cur_chars[] = "BDCA";
+
+	if (up_flag)
+		return;
+
+	applkey(vc, cur_chars[value], vc_kbd_mode(kbd, VC_CKMODE));
+}
+
+static void k_pad(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	static const char pad_chars[] = "0123456789+-*/\015,.?()#";
+	static const char app_map[] = "pqrstuvwxylSRQMnnmPQS";
+
+	if (up_flag)
+		return;		/* no action, if this is a key release */
+
+	/* kludge... shift forces cursor/number keys */
+	if (vc_kbd_mode(kbd, VC_APPLIC) && !shift_down[KG_SHIFT]) {
+		applkey(vc, app_map[value], 1);
+		return;
+	}
+
+	if (!vc_kbd_led(kbd, VC_NUMLOCK)) {
+
+		switch (value) {
+		case KVAL(K_PCOMMA):
+		case KVAL(K_PDOT):
+			k_fn(vc, KVAL(K_REMOVE), 0);
+			return;
+		case KVAL(K_P0):
+			k_fn(vc, KVAL(K_INSERT), 0);
+			return;
+		case KVAL(K_P1):
+			k_fn(vc, KVAL(K_SELECT), 0);
+			return;
+		case KVAL(K_P2):
+			k_cur(vc, KVAL(K_DOWN), 0);
+			return;
+		case KVAL(K_P3):
+			k_fn(vc, KVAL(K_PGDN), 0);
+			return;
+		case KVAL(K_P4):
+			k_cur(vc, KVAL(K_LEFT), 0);
+			return;
+		case KVAL(K_P6):
+			k_cur(vc, KVAL(K_RIGHT), 0);
+			return;
+		case KVAL(K_P7):
+			k_fn(vc, KVAL(K_FIND), 0);
+			return;
+		case KVAL(K_P8):
+			k_cur(vc, KVAL(K_UP), 0);
+			return;
+		case KVAL(K_P9):
+			k_fn(vc, KVAL(K_PGUP), 0);
+			return;
+		case KVAL(K_P5):
+			applkey(vc, 'G', vc_kbd_mode(kbd, VC_APPLIC));
+			return;
+		}
+	}
+
+	put_queue(vc, pad_chars[value]);
+	if (value == KVAL(K_PENTER) && vc_kbd_mode(kbd, VC_CRLF))
+		put_queue(vc, 10);
+}
+
+static void k_shift(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	int old_state = shift_state;
+
+	if (rep)
+		return;
+	/*
+	 * Mimic typewriter:
+	 * a CapsShift key acts like Shift but undoes CapsLock
+	 */
+	if (value == KVAL(K_CAPSSHIFT)) {
+		value = KVAL(K_SHIFT);
+		if (!up_flag)
+			clr_vc_kbd_led(kbd, VC_CAPSLOCK);
+	}
+
+	if (up_flag) {
+		/*
+		 * handle the case that two shift or control
+		 * keys are depressed simultaneously
+		 */
+		if (shift_down[value])
+			shift_down[value]--;
+	} else
+		shift_down[value]++;
+
+	if (shift_down[value])
+		shift_state |= (1 << value);
+	else
+		shift_state &= ~(1 << value);
+
+	/* kludge */
+	if (up_flag && shift_state != old_state && npadch != -1) {
+		if (kbd->kbdmode == VC_UNICODE)
+			to_utf8(vc, npadch);
+		else
+			put_queue(vc, npadch & 0xff);
+		npadch = -1;
+	}
+}
+
+static void k_meta(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	if (up_flag)
+		return;
+
+	if (vc_kbd_mode(kbd, VC_META)) {
+		put_queue(vc, '\033');
+		put_queue(vc, value);
+	} else
+		put_queue(vc, value | 0x80);
+}
+
+static void k_ascii(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	int base;
+
+	if (up_flag)
+		return;
+
+	if (value < 10) {
+		/* decimal input of code, while Alt depressed */
+		base = 10;
+	} else {
+		/* hexadecimal input of code, while AltGr depressed */
+		value -= 10;
+		base = 16;
+	}
+
+	if (npadch == -1)
+		npadch = value;
+	else
+		npadch = npadch * base + value;
+}
+
+static void k_lock(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	if (up_flag || rep)
+		return;
+
+	chg_vc_kbd_lock(kbd, value);
+}
+
+static void k_slock(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	k_shift(vc, value, up_flag);
+	if (up_flag || rep)
+		return;
+
+	chg_vc_kbd_slock(kbd, value);
+	/* try to make Alt, oops, AltGr and such work */
+	if (!key_maps[kbd->lockstate ^ kbd->slockstate]) {
+		kbd->slockstate = 0;
+		chg_vc_kbd_slock(kbd, value);
+	}
+}
+
+/* by default, 300ms interval for combination release */
+static unsigned brl_timeout = 300;
+MODULE_PARM_DESC(brl_timeout, "Braille keys release delay in ms (0 for commit on first key release)");
+module_param(brl_timeout, uint, 0644);
+
+static unsigned brl_nbchords = 1;
+MODULE_PARM_DESC(brl_nbchords, "Number of chords that produce a braille pattern (0 for dead chords)");
+module_param(brl_nbchords, uint, 0644);
+
+static void k_brlcommit(struct vc_data *vc, unsigned int pattern, char up_flag)
+{
+	static unsigned long chords;
+	static unsigned committed;
+
+	if (!brl_nbchords)
+		k_deadunicode(vc, BRL_UC_ROW | pattern, up_flag);
+	else {
+		committed |= pattern;
+		chords++;
+		if (chords == brl_nbchords) {
+			k_unicode(vc, BRL_UC_ROW | committed, up_flag);
+			chords = 0;
+			committed = 0;
+		}
+	}
+}
+
+static void k_brl(struct vc_data *vc, unsigned char value, char up_flag)
+{
+	static unsigned pressed, committing;
+	static unsigned long releasestart;
+
+	if (kbd->kbdmode != VC_UNICODE) {
+		if (!up_flag)
+			pr_warning("keyboard mode must be unicode for braille patterns\n");
+		return;
+	}
+
+	if (!value) {
+		k_unicode(vc, BRL_UC_ROW, up_flag);
+		return;
+	}
+
+	if (value > 8)
+		return;
+
+	if (!up_flag) {
+		pressed |= 1 << (value - 1);
+		if (!brl_timeout)
+			committing = pressed;
+	} else if (brl_timeout) {
+		if (!committing ||
+		    time_after(jiffies,
+			       releasestart + msecs_to_jiffies(brl_timeout))) {
+			committing = pressed;
+			releasestart = jiffies;
+		}
+		pressed &= ~(1 << (value - 1));
+		if (!pressed && committing) {
+			k_brlcommit(vc, committing, 0);
+			committing = 0;
+		}
+	} else {
+		if (committing) {
+			k_brlcommit(vc, committing, 0);
+			committing = 0;
+		}
+		pressed &= ~(1 << (value - 1));
+	}
+}
+
+/*
+ * The leds display either (i) the status of NumLock, CapsLock, ScrollLock,
+ * or (ii) whatever pattern of lights people want to show using KDSETLED,
+ * or (iii) specified bits of specified words in kernel memory.
+ */
+unsigned char getledstate(void)
+{
+	return ledstate;
+}
+
+void setledstate(struct kbd_struct *kbd, unsigned int led)
+{
+	if (!(led & ~7)) {
+		ledioctl = led;
+		kbd->ledmode = LED_SHOW_IOCTL;
+	} else
+		kbd->ledmode = LED_SHOW_FLAGS;
+
+	set_leds();
+}
+
+static inline unsigned char getleds(void)
+{
+	struct kbd_struct *kbd = kbd_table + fg_console;
+	unsigned char leds;
+	int i;
+
+	if (kbd->ledmode == LED_SHOW_IOCTL)
+		return ledioctl;
+
+	leds = kbd->ledflagstate;
+
+	if (kbd->ledmode == LED_SHOW_MEM) {
+		for (i = 0; i < 3; i++)
+			if (ledptrs[i].valid) {
+				if (*ledptrs[i].addr & ledptrs[i].mask)
+					leds |= (1 << i);
+				else
+					leds &= ~(1 << i);
+			}
+	}
+	return leds;
+}
+
+static int kbd_update_leds_helper(struct input_handle *handle, void *data)
+{
+	unsigned char leds = *(unsigned char *)data;
+
+	if (test_bit(EV_LED, handle->dev->evbit)) {
+		input_inject_event(handle, EV_LED, LED_SCROLLL, !!(leds & 0x01));
+		input_inject_event(handle, EV_LED, LED_NUML,    !!(leds & 0x02));
+		input_inject_event(handle, EV_LED, LED_CAPSL,   !!(leds & 0x04));
+		input_inject_event(handle, EV_SYN, SYN_REPORT, 0);
+	}
+
+	return 0;
+}
+
+/*
+ * This is the tasklet that updates LED state on all keyboards
+ * attached to the box. The reason we use tasklet is that we
+ * need to handle the scenario when keyboard handler is not
+ * registered yet but we already getting updates form VT to
+ * update led state.
+ */
+static void kbd_bh(unsigned long dummy)
+{
+	unsigned char leds = getleds();
+
+	if (leds != ledstate) {
+		input_handler_for_each_handle(&kbd_handler, &leds,
+					      kbd_update_leds_helper);
+		ledstate = leds;
+	}
+}
+
+DECLARE_TASKLET_DISABLED(keyboard_tasklet, kbd_bh, 0);
+
+#if defined(CONFIG_X86) || defined(CONFIG_IA64) || defined(CONFIG_ALPHA) ||\
+    defined(CONFIG_MIPS) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) ||\
+    defined(CONFIG_PARISC) || defined(CONFIG_SUPERH) ||\
+    (defined(CONFIG_ARM) && defined(CONFIG_KEYBOARD_ATKBD) && !defined(CONFIG_ARCH_RPC)) ||\
+    defined(CONFIG_AVR32)
+
+#define HW_RAW(dev) (test_bit(EV_MSC, dev->evbit) && test_bit(MSC_RAW, dev->mscbit) &&\
+			((dev)->id.bustype == BUS_I8042) && ((dev)->id.vendor == 0x0001) && ((dev)->id.product == 0x0001))
+
+static const unsigned short x86_keycodes[256] =
+	{ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
+	 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
+	 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
+	 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
+	 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
+	 80, 81, 82, 83, 84,118, 86, 87, 88,115,120,119,121,112,123, 92,
+	284,285,309,  0,312, 91,327,328,329,331,333,335,336,337,338,339,
+	367,288,302,304,350, 89,334,326,267,126,268,269,125,347,348,349,
+	360,261,262,263,268,376,100,101,321,316,373,286,289,102,351,355,
+	103,104,105,275,287,279,258,106,274,107,294,364,358,363,362,361,
+	291,108,381,281,290,272,292,305,280, 99,112,257,306,359,113,114,
+	264,117,271,374,379,265,266, 93, 94, 95, 85,259,375,260, 90,116,
+	377,109,111,277,278,282,283,295,296,297,299,300,301,293,303,307,
+	308,310,313,314,315,317,318,319,320,357,322,323,324,325,276,330,
+	332,340,365,342,343,344,345,346,356,270,341,368,369,370,371,372 };
+
+#ifdef CONFIG_SPARC
+static int sparc_l1_a_state;
+extern void sun_do_break(void);
+#endif
+
+static int emulate_raw(struct vc_data *vc, unsigned int keycode,
+		       unsigned char up_flag)
+{
+	int code;
+
+	switch (keycode) {
+
+	case KEY_PAUSE:
+		put_queue(vc, 0xe1);
+		put_queue(vc, 0x1d | up_flag);
+		put_queue(vc, 0x45 | up_flag);
+		break;
+
+	case KEY_HANGEUL:
+		if (!up_flag)
+			put_queue(vc, 0xf2);
+		break;
+
+	case KEY_HANJA:
+		if (!up_flag)
+			put_queue(vc, 0xf1);
+		break;
+
+	case KEY_SYSRQ:
+		/*
+		 * Real AT keyboards (that's what we're trying
+		 * to emulate here emit 0xe0 0x2a 0xe0 0x37 when
+		 * pressing PrtSc/SysRq alone, but simply 0x54
+		 * when pressing Alt+PrtSc/SysRq.
+		 */
+		if (test_bit(KEY_LEFTALT, key_down) ||
+		    test_bit(KEY_RIGHTALT, key_down)) {
+			put_queue(vc, 0x54 | up_flag);
+		} else {
+			put_queue(vc, 0xe0);
+			put_queue(vc, 0x2a | up_flag);
+			put_queue(vc, 0xe0);
+			put_queue(vc, 0x37 | up_flag);
+		}
+		break;
+
+	default:
+		if (keycode > 255)
+			return -1;
+
+		code = x86_keycodes[keycode];
+		if (!code)
+			return -1;
+
+		if (code & 0x100)
+			put_queue(vc, 0xe0);
+		put_queue(vc, (code & 0x7f) | up_flag);
+
+		break;
+	}
+
+	return 0;
+}
+
+#else
+
+#define HW_RAW(dev)	0
+
+static int emulate_raw(struct vc_data *vc, unsigned int keycode, unsigned char up_flag)
+{
+	if (keycode > 127)
+		return -1;
+
+	put_queue(vc, keycode | up_flag);
+	return 0;
+}
+#endif
+
+static void kbd_rawcode(unsigned char data)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+
+	kbd = kbd_table + vc->vc_num;
+	if (kbd->kbdmode == VC_RAW)
+		put_queue(vc, data);
+}
+
+static void kbd_keycode(unsigned int keycode, int down, int hw_raw)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+	unsigned short keysym, *key_map;
+	unsigned char type;
+	bool raw_mode;
+	struct tty_struct *tty;
+	int shift_final;
+	struct keyboard_notifier_param param = { .vc = vc, .value = keycode, .down = down };
+	int rc;
+
+	tty = vc->port.tty;
+
+	if (tty && (!tty->driver_data)) {
+		/* No driver data? Strange. Okay we fix it then. */
+		tty->driver_data = vc;
+	}
+
+	kbd = kbd_table + vc->vc_num;
+
+#ifdef CONFIG_SPARC
+	if (keycode == KEY_STOP)
+		sparc_l1_a_state = down;
+#endif
+
+	rep = (down == 2);
+
+	raw_mode = (kbd->kbdmode == VC_RAW);
+	if (raw_mode && !hw_raw)
+		if (emulate_raw(vc, keycode, !down << 7))
+			if (keycode < BTN_MISC && printk_ratelimit())
+				pr_warning("can't emulate rawmode for keycode %d\n",
+					   keycode);
+
+#ifdef CONFIG_SPARC
+	if (keycode == KEY_A && sparc_l1_a_state) {
+		sparc_l1_a_state = false;
+		sun_do_break();
+	}
+#endif
+
+	if (kbd->kbdmode == VC_MEDIUMRAW) {
+		/*
+		 * This is extended medium raw mode, with keys above 127
+		 * encoded as 0, high 7 bits, low 7 bits, with the 0 bearing
+		 * the 'up' flag if needed. 0 is reserved, so this shouldn't
+		 * interfere with anything else. The two bytes after 0 will
+		 * always have the up flag set not to interfere with older
+		 * applications. This allows for 16384 different keycodes,
+		 * which should be enough.
+		 */
+		if (keycode < 128) {
+			put_queue(vc, keycode | (!down << 7));
+		} else {
+			put_queue(vc, !down << 7);
+			put_queue(vc, (keycode >> 7) | 0x80);
+			put_queue(vc, keycode | 0x80);
+		}
+		raw_mode = true;
+	}
+
+	if (down)
+		set_bit(keycode, key_down);
+	else
+		clear_bit(keycode, key_down);
+
+	if (rep &&
+	    (!vc_kbd_mode(kbd, VC_REPEAT) ||
+	     (tty && !L_ECHO(tty) && tty_chars_in_buffer(tty)))) {
+		/*
+		 * Don't repeat a key if the input buffers are not empty and the
+		 * characters get aren't echoed locally. This makes key repeat
+		 * usable with slow applications and under heavy loads.
+		 */
+		return;
+	}
+
+	param.shift = shift_final = (shift_state | kbd->slockstate) ^ kbd->lockstate;
+	param.ledstate = kbd->ledflagstate;
+	key_map = key_maps[shift_final];
+
+	rc = atomic_notifier_call_chain(&keyboard_notifier_list,
+					KBD_KEYCODE, &param);
+	if (rc == NOTIFY_STOP || !key_map) {
+		atomic_notifier_call_chain(&keyboard_notifier_list,
+					   KBD_UNBOUND_KEYCODE, &param);
+		compute_shiftstate();
+		kbd->slockstate = 0;
+		return;
+	}
+
+	if (keycode < NR_KEYS)
+		keysym = key_map[keycode];
+	else if (keycode >= KEY_BRL_DOT1 && keycode <= KEY_BRL_DOT8)
+		keysym = U(K(KT_BRL, keycode - KEY_BRL_DOT1 + 1));
+	else
+		return;
+
+	type = KTYP(keysym);
+
+	if (type < 0xf0) {
+		param.value = keysym;
+		rc = atomic_notifier_call_chain(&keyboard_notifier_list,
+						KBD_UNICODE, &param);
+		if (rc != NOTIFY_STOP)
+			if (down && !raw_mode)
+				to_utf8(vc, keysym);
+		return;
+	}
+
+	type -= 0xf0;
+
+	if (type == KT_LETTER) {
+		type = KT_LATIN;
+		if (vc_kbd_led(kbd, VC_CAPSLOCK)) {
+			key_map = key_maps[shift_final ^ (1 << KG_SHIFT)];
+			if (key_map)
+				keysym = key_map[keycode];
+		}
+	}
+
+	param.value = keysym;
+	rc = atomic_notifier_call_chain(&keyboard_notifier_list,
+					KBD_KEYSYM, &param);
+	if (rc == NOTIFY_STOP)
+		return;
+
+	if (raw_mode && type != KT_SPEC && type != KT_SHIFT)
+		return;
+
+	(*k_handler[type])(vc, keysym & 0xff, !down);
+
+	param.ledstate = kbd->ledflagstate;
+	atomic_notifier_call_chain(&keyboard_notifier_list, KBD_POST_KEYSYM, &param);
+
+	if (type != KT_SLOCK)
+		kbd->slockstate = 0;
+}
+
+static void kbd_event(struct input_handle *handle, unsigned int event_type,
+		      unsigned int event_code, int value)
+{
+	/* We are called with interrupts disabled, just take the lock */
+	spin_lock(&kbd_event_lock);
+
+	if (event_type == EV_MSC && event_code == MSC_RAW && HW_RAW(handle->dev))
+		kbd_rawcode(value);
+	if (event_type == EV_KEY)
+		kbd_keycode(event_code, value, HW_RAW(handle->dev));
+
+	spin_unlock(&kbd_event_lock);
+
+	tasklet_schedule(&keyboard_tasklet);
+	do_poke_blanked_console = 1;
+	schedule_console_callback();
+}
+
+static bool kbd_match(struct input_handler *handler, struct input_dev *dev)
+{
+	int i;
+
+	if (test_bit(EV_SND, dev->evbit))
+		return true;
+
+	if (test_bit(EV_KEY, dev->evbit)) {
+		for (i = KEY_RESERVED; i < BTN_MISC; i++)
+			if (test_bit(i, dev->keybit))
+				return true;
+		for (i = KEY_BRL_DOT1; i <= KEY_BRL_DOT10; i++)
+			if (test_bit(i, dev->keybit))
+				return true;
+	}
+
+	return false;
+}
+
+/*
+ * When a keyboard (or other input device) is found, the kbd_connect
+ * function is called. The function then looks at the device, and if it
+ * likes it, it can open it and get events from it. In this (kbd_connect)
+ * function, we should decide which VT to bind that keyboard to initially.
+ */
+static int kbd_connect(struct input_handler *handler, struct input_dev *dev,
+			const struct input_device_id *id)
+{
+	struct input_handle *handle;
+	int error;
+
+	handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
+	if (!handle)
+		return -ENOMEM;
+
+	handle->dev = dev;
+	handle->handler = handler;
+	handle->name = "kbd";
+
+	error = input_register_handle(handle);
+	if (error)
+		goto err_free_handle;
+
+	error = input_open_device(handle);
+	if (error)
+		goto err_unregister_handle;
+
+	return 0;
+
+ err_unregister_handle:
+	input_unregister_handle(handle);
+ err_free_handle:
+	kfree(handle);
+	return error;
+}
+
+static void kbd_disconnect(struct input_handle *handle)
+{
+	input_close_device(handle);
+	input_unregister_handle(handle);
+	kfree(handle);
+}
+
+/*
+ * Start keyboard handler on the new keyboard by refreshing LED state to
+ * match the rest of the system.
+ */
+static void kbd_start(struct input_handle *handle)
+{
+	tasklet_disable(&keyboard_tasklet);
+
+	if (ledstate != 0xff)
+		kbd_update_leds_helper(handle, &ledstate);
+
+	tasklet_enable(&keyboard_tasklet);
+}
+
+static const struct input_device_id kbd_ids[] = {
+	{
+                .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
+                .evbit = { BIT_MASK(EV_KEY) },
+        },
+
+	{
+                .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
+                .evbit = { BIT_MASK(EV_SND) },
+        },
+
+	{ },    /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(input, kbd_ids);
+
+static struct input_handler kbd_handler = {
+	.event		= kbd_event,
+	.match		= kbd_match,
+	.connect	= kbd_connect,
+	.disconnect	= kbd_disconnect,
+	.start		= kbd_start,
+	.name		= "kbd",
+	.id_table	= kbd_ids,
+};
+
+int __init kbd_init(void)
+{
+	int i;
+	int error;
+
+        for (i = 0; i < MAX_NR_CONSOLES; i++) {
+		kbd_table[i].ledflagstate = KBD_DEFLEDS;
+		kbd_table[i].default_ledflagstate = KBD_DEFLEDS;
+		kbd_table[i].ledmode = LED_SHOW_FLAGS;
+		kbd_table[i].lockstate = KBD_DEFLOCK;
+		kbd_table[i].slockstate = 0;
+		kbd_table[i].modeflags = KBD_DEFMODE;
+		kbd_table[i].kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
+	}
+
+	error = input_register_handler(&kbd_handler);
+	if (error)
+		return error;
+
+	tasklet_enable(&keyboard_tasklet);
+	tasklet_schedule(&keyboard_tasklet);
+
+	return 0;
+}
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c
new file mode 100644
index 0000000..ebae344
--- /dev/null
+++ b/drivers/tty/vt/selection.c
@@ -0,0 +1,348 @@
+/*
+ * linux/drivers/char/selection.c
+ *
+ * This module exports the functions:
+ *
+ *     'int set_selection(struct tiocl_selection __user *, struct tty_struct *)'
+ *     'void clear_selection(void)'
+ *     'int paste_selection(struct tty_struct *)'
+ *     'int sel_loadlut(char __user *)'
+ *
+ * Now that /dev/vcs exists, most of this can disappear again.
+ */
+
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <asm/uaccess.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/consolemap.h>
+#include <linux/selection.h>
+#include <linux/tiocl.h>
+#include <linux/console.h>
+#include <linux/smp_lock.h>
+
+/* Don't take this from <ctype.h>: 011-015 on the screen aren't spaces */
+#define isspace(c)	((c) == ' ')
+
+extern void poke_blanked_console(void);
+
+/* Variables for selection control. */
+/* Use a dynamic buffer, instead of static (Dec 1994) */
+struct vc_data *sel_cons;		/* must not be deallocated */
+static int use_unicode;
+static volatile int sel_start = -1; 	/* cleared by clear_selection */
+static int sel_end;
+static int sel_buffer_lth;
+static char *sel_buffer;
+
+/* clear_selection, highlight and highlight_pointer can be called
+   from interrupt (via scrollback/front) */
+
+/* set reverse video on characters s-e of console with selection. */
+static inline void highlight(const int s, const int e)
+{
+	invert_screen(sel_cons, s, e-s+2, 1);
+}
+
+/* use complementary color to show the pointer */
+static inline void highlight_pointer(const int where)
+{
+	complement_pos(sel_cons, where);
+}
+
+static u16
+sel_pos(int n)
+{
+	return inverse_translate(sel_cons, screen_glyph(sel_cons, n),
+				use_unicode);
+}
+
+/* remove the current selection highlight, if any,
+   from the console holding the selection. */
+void
+clear_selection(void) {
+	highlight_pointer(-1); /* hide the pointer */
+	if (sel_start != -1) {
+		highlight(sel_start, sel_end);
+		sel_start = -1;
+	}
+}
+
+/*
+ * User settable table: what characters are to be considered alphabetic?
+ * 256 bits
+ */
+static u32 inwordLut[8]={
+  0x00000000, /* control chars     */
+  0x03FF0000, /* digits            */
+  0x87FFFFFE, /* uppercase and '_' */
+  0x07FFFFFE, /* lowercase         */
+  0x00000000,
+  0x00000000,
+  0xFF7FFFFF, /* latin-1 accented letters, not multiplication sign */
+  0xFF7FFFFF  /* latin-1 accented letters, not division sign */
+};
+
+static inline int inword(const u16 c) {
+	return c > 0xff || (( inwordLut[c>>5] >> (c & 0x1F) ) & 1);
+}
+
+/* set inwordLut contents. Invoked by ioctl(). */
+int sel_loadlut(char __user *p)
+{
+	return copy_from_user(inwordLut, (u32 __user *)(p+4), 32) ? -EFAULT : 0;
+}
+
+/* does screen address p correspond to character at LH/RH edge of screen? */
+static inline int atedge(const int p, int size_row)
+{
+	return (!(p % size_row)	|| !((p + 2) % size_row));
+}
+
+/* constrain v such that v <= u */
+static inline unsigned short limit(const unsigned short v, const unsigned short u)
+{
+	return (v > u) ? u : v;
+}
+
+/* stores the char in UTF8 and returns the number of bytes used (1-3) */
+static int store_utf8(u16 c, char *p)
+{
+	if (c < 0x80) {
+		/*  0******* */
+		p[0] = c;
+		return 1;
+	} else if (c < 0x800) {
+		/* 110***** 10****** */
+		p[0] = 0xc0 | (c >> 6);
+		p[1] = 0x80 | (c & 0x3f);
+		return 2;
+    	} else {
+		/* 1110**** 10****** 10****** */
+		p[0] = 0xe0 | (c >> 12);
+		p[1] = 0x80 | ((c >> 6) & 0x3f);
+		p[2] = 0x80 | (c & 0x3f);
+		return 3;
+    	}
+}
+
+/* set the current selection. Invoked by ioctl() or by kernel code. */
+int set_selection(const struct tiocl_selection __user *sel, struct tty_struct *tty)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+	int sel_mode, new_sel_start, new_sel_end, spc;
+	char *bp, *obp;
+	int i, ps, pe, multiplier;
+	u16 c;
+	struct kbd_struct *kbd = kbd_table + fg_console;
+
+	poke_blanked_console();
+
+	{ unsigned short xs, ys, xe, ye;
+
+	  if (!access_ok(VERIFY_READ, sel, sizeof(*sel)))
+		return -EFAULT;
+	  __get_user(xs, &sel->xs);
+	  __get_user(ys, &sel->ys);
+	  __get_user(xe, &sel->xe);
+	  __get_user(ye, &sel->ye);
+	  __get_user(sel_mode, &sel->sel_mode);
+	  xs--; ys--; xe--; ye--;
+	  xs = limit(xs, vc->vc_cols - 1);
+	  ys = limit(ys, vc->vc_rows - 1);
+	  xe = limit(xe, vc->vc_cols - 1);
+	  ye = limit(ye, vc->vc_rows - 1);
+	  ps = ys * vc->vc_size_row + (xs << 1);
+	  pe = ye * vc->vc_size_row + (xe << 1);
+
+	  if (sel_mode == TIOCL_SELCLEAR) {
+	      /* useful for screendump without selection highlights */
+	      clear_selection();
+	      return 0;
+	  }
+
+	  if (mouse_reporting() && (sel_mode & TIOCL_SELMOUSEREPORT)) {
+	      mouse_report(tty, sel_mode & TIOCL_SELBUTTONMASK, xs, ys);
+	      return 0;
+	  }
+        }
+
+	if (ps > pe)	/* make sel_start <= sel_end */
+	{
+		int tmp = ps;
+		ps = pe;
+		pe = tmp;
+	}
+
+	if (sel_cons != vc_cons[fg_console].d) {
+		clear_selection();
+		sel_cons = vc_cons[fg_console].d;
+	}
+	use_unicode = kbd && kbd->kbdmode == VC_UNICODE;
+
+	switch (sel_mode)
+	{
+		case TIOCL_SELCHAR:	/* character-by-character selection */
+			new_sel_start = ps;
+			new_sel_end = pe;
+			break;
+		case TIOCL_SELWORD:	/* word-by-word selection */
+			spc = isspace(sel_pos(ps));
+			for (new_sel_start = ps; ; ps -= 2)
+			{
+				if ((spc && !isspace(sel_pos(ps))) ||
+				    (!spc && !inword(sel_pos(ps))))
+					break;
+				new_sel_start = ps;
+				if (!(ps % vc->vc_size_row))
+					break;
+			}
+			spc = isspace(sel_pos(pe));
+			for (new_sel_end = pe; ; pe += 2)
+			{
+				if ((spc && !isspace(sel_pos(pe))) ||
+				    (!spc && !inword(sel_pos(pe))))
+					break;
+				new_sel_end = pe;
+				if (!((pe + 2) % vc->vc_size_row))
+					break;
+			}
+			break;
+		case TIOCL_SELLINE:	/* line-by-line selection */
+			new_sel_start = ps - ps % vc->vc_size_row;
+			new_sel_end = pe + vc->vc_size_row
+				    - pe % vc->vc_size_row - 2;
+			break;
+		case TIOCL_SELPOINTER:
+			highlight_pointer(pe);
+			return 0;
+		default:
+			return -EINVAL;
+	}
+
+	/* remove the pointer */
+	highlight_pointer(-1);
+
+	/* select to end of line if on trailing space */
+	if (new_sel_end > new_sel_start &&
+		!atedge(new_sel_end, vc->vc_size_row) &&
+		isspace(sel_pos(new_sel_end))) {
+		for (pe = new_sel_end + 2; ; pe += 2)
+			if (!isspace(sel_pos(pe)) ||
+			    atedge(pe, vc->vc_size_row))
+				break;
+		if (isspace(sel_pos(pe)))
+			new_sel_end = pe;
+	}
+	if (sel_start == -1)	/* no current selection */
+		highlight(new_sel_start, new_sel_end);
+	else if (new_sel_start == sel_start)
+	{
+		if (new_sel_end == sel_end)	/* no action required */
+			return 0;
+		else if (new_sel_end > sel_end)	/* extend to right */
+			highlight(sel_end + 2, new_sel_end);
+		else				/* contract from right */
+			highlight(new_sel_end + 2, sel_end);
+	}
+	else if (new_sel_end == sel_end)
+	{
+		if (new_sel_start < sel_start)	/* extend to left */
+			highlight(new_sel_start, sel_start - 2);
+		else				/* contract from left */
+			highlight(sel_start, new_sel_start - 2);
+	}
+	else	/* some other case; start selection from scratch */
+	{
+		clear_selection();
+		highlight(new_sel_start, new_sel_end);
+	}
+	sel_start = new_sel_start;
+	sel_end = new_sel_end;
+
+	/* Allocate a new buffer before freeing the old one ... */
+	multiplier = use_unicode ? 3 : 1;  /* chars can take up to 3 bytes */
+	bp = kmalloc(((sel_end-sel_start)/2+1)*multiplier, GFP_KERNEL);
+	if (!bp) {
+		printk(KERN_WARNING "selection: kmalloc() failed\n");
+		clear_selection();
+		return -ENOMEM;
+	}
+	kfree(sel_buffer);
+	sel_buffer = bp;
+
+	obp = bp;
+	for (i = sel_start; i <= sel_end; i += 2) {
+		c = sel_pos(i);
+		if (use_unicode)
+			bp += store_utf8(c, bp);
+		else
+			*bp++ = c;
+		if (!isspace(c))
+			obp = bp;
+		if (! ((i + 2) % vc->vc_size_row)) {
+			/* strip trailing blanks from line and add newline,
+			   unless non-space at end of line. */
+			if (obp != bp) {
+				bp = obp;
+				*bp++ = '\r';
+			}
+			obp = bp;
+		}
+	}
+	sel_buffer_lth = bp - sel_buffer;
+	return 0;
+}
+
+/* Insert the contents of the selection buffer into the
+ * queue of the tty associated with the current console.
+ * Invoked by ioctl().
+ */
+int paste_selection(struct tty_struct *tty)
+{
+	struct vc_data *vc = tty->driver_data;
+	int	pasted = 0;
+	unsigned int count;
+	struct  tty_ldisc *ld;
+	DECLARE_WAITQUEUE(wait, current);
+
+	/* always called with BTM from vt_ioctl */
+	WARN_ON(!tty_locked());
+
+	acquire_console_sem();
+	poke_blanked_console();
+	release_console_sem();
+
+	ld = tty_ldisc_ref(tty);
+	if (!ld) {
+		tty_unlock();
+		ld = tty_ldisc_ref_wait(tty);
+		tty_lock();
+	}
+
+	add_wait_queue(&vc->paste_wait, &wait);
+	while (sel_buffer && sel_buffer_lth > pasted) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (test_bit(TTY_THROTTLED, &tty->flags)) {
+			schedule();
+			continue;
+		}
+		count = sel_buffer_lth - pasted;
+		count = min(count, tty->receive_room);
+		tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted,
+								NULL, count);
+		pasted += count;
+	}
+	remove_wait_queue(&vc->paste_wait, &wait);
+	__set_current_state(TASK_RUNNING);
+
+	tty_ldisc_deref(ld);
+	return 0;
+}
diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c
new file mode 100644
index 0000000..eab3a1f
--- /dev/null
+++ b/drivers/tty/vt/vc_screen.c
@@ -0,0 +1,644 @@
+/*
+ * linux/drivers/char/vc_screen.c
+ *
+ * Provide access to virtual console memory.
+ * /dev/vcs0: the screen as it is being viewed right now (possibly scrolled)
+ * /dev/vcsN: the screen of /dev/ttyN (1 <= N <= 63)
+ *            [minor: N]
+ *
+ * /dev/vcsaN: idem, but including attributes, and prefixed with
+ *	the 4 bytes lines,columns,x,y (as screendump used to give).
+ *	Attribute/character pair is in native endianity.
+ *            [minor: N+128]
+ *
+ * This replaces screendump and part of selection, so that the system
+ * administrator can control access using file system permissions.
+ *
+ * aeb@cwi.nl - efter Friedas begravelse - 950211
+ *
+ * machek@k332.feld.cvut.cz - modified not to send characters to wrong console
+ *	 - fixed some fatal off-by-one bugs (0-- no longer == -1 -> looping and looping and looping...)
+ *	 - making it shorter - scr_readw are macros which expand in PRETTY long code
+ */
+
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/interrupt.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+#include <linux/kbd_kern.h>
+#include <linux/console.h>
+#include <linux/device.h>
+#include <linux/smp_lock.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/signal.h>
+#include <linux/slab.h>
+#include <linux/notifier.h>
+
+#include <asm/uaccess.h>
+#include <asm/byteorder.h>
+#include <asm/unaligned.h>
+
+#undef attr
+#undef org
+#undef addr
+#define HEADER_SIZE	4
+
+struct vcs_poll_data {
+	struct notifier_block notifier;
+	unsigned int cons_num;
+	bool seen_last_update;
+	wait_queue_head_t waitq;
+	struct fasync_struct *fasync;
+};
+
+static int
+vcs_notifier(struct notifier_block *nb, unsigned long code, void *_param)
+{
+	struct vt_notifier_param *param = _param;
+	struct vc_data *vc = param->vc;
+	struct vcs_poll_data *poll =
+		container_of(nb, struct vcs_poll_data, notifier);
+	int currcons = poll->cons_num;
+
+	if (code != VT_UPDATE)
+		return NOTIFY_DONE;
+
+	if (currcons == 0)
+		currcons = fg_console;
+	else
+		currcons--;
+	if (currcons != vc->vc_num)
+		return NOTIFY_DONE;
+
+	poll->seen_last_update = false;
+	wake_up_interruptible(&poll->waitq);
+	kill_fasync(&poll->fasync, SIGIO, POLL_IN);
+	return NOTIFY_OK;
+}
+
+static void
+vcs_poll_data_free(struct vcs_poll_data *poll)
+{
+	unregister_vt_notifier(&poll->notifier);
+	kfree(poll);
+}
+
+static struct vcs_poll_data *
+vcs_poll_data_get(struct file *file)
+{
+	struct vcs_poll_data *poll = file->private_data;
+
+	if (poll)
+		return poll;
+
+	poll = kzalloc(sizeof(*poll), GFP_KERNEL);
+	if (!poll)
+		return NULL;
+	poll->cons_num = iminor(file->f_path.dentry->d_inode) & 127;
+	init_waitqueue_head(&poll->waitq);
+	poll->notifier.notifier_call = vcs_notifier;
+	if (register_vt_notifier(&poll->notifier) != 0) {
+		kfree(poll);
+		return NULL;
+	}
+
+	/*
+	 * This code may be called either through ->poll() or ->fasync().
+	 * If we have two threads using the same file descriptor, they could
+	 * both enter this function, both notice that the structure hasn't
+	 * been allocated yet and go ahead allocating it in parallel, but
+	 * only one of them must survive and be shared otherwise we'd leak
+	 * memory with a dangling notifier callback.
+	 */
+	spin_lock(&file->f_lock);
+	if (!file->private_data) {
+		file->private_data = poll;
+	} else {
+		/* someone else raced ahead of us */
+		vcs_poll_data_free(poll);
+		poll = file->private_data;
+	}
+	spin_unlock(&file->f_lock);
+
+	return poll;
+}
+
+static int
+vcs_size(struct inode *inode)
+{
+	int size;
+	int minor = iminor(inode);
+	int currcons = minor & 127;
+	struct vc_data *vc;
+
+	if (currcons == 0)
+		currcons = fg_console;
+	else
+		currcons--;
+	if (!vc_cons_allocated(currcons))
+		return -ENXIO;
+	vc = vc_cons[currcons].d;
+
+	size = vc->vc_rows * vc->vc_cols;
+
+	if (minor & 128)
+		size = 2*size + HEADER_SIZE;
+	return size;
+}
+
+static loff_t vcs_lseek(struct file *file, loff_t offset, int orig)
+{
+	int size;
+
+	mutex_lock(&con_buf_mtx);
+	size = vcs_size(file->f_path.dentry->d_inode);
+	switch (orig) {
+		default:
+			mutex_unlock(&con_buf_mtx);
+			return -EINVAL;
+		case 2:
+			offset += size;
+			break;
+		case 1:
+			offset += file->f_pos;
+		case 0:
+			break;
+	}
+	if (offset < 0 || offset > size) {
+		mutex_unlock(&con_buf_mtx);
+		return -EINVAL;
+	}
+	file->f_pos = offset;
+	mutex_unlock(&con_buf_mtx);
+	return file->f_pos;
+}
+
+
+static ssize_t
+vcs_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	unsigned int currcons = iminor(inode);
+	struct vc_data *vc;
+	struct vcs_poll_data *poll;
+	long pos;
+	long viewed, attr, read;
+	int col, maxcol;
+	unsigned short *org = NULL;
+	ssize_t ret;
+
+	mutex_lock(&con_buf_mtx);
+
+	pos = *ppos;
+
+	/* Select the proper current console and verify
+	 * sanity of the situation under the console lock.
+	 */
+	acquire_console_sem();
+
+	attr = (currcons & 128);
+	currcons = (currcons & 127);
+	if (currcons == 0) {
+		currcons = fg_console;
+		viewed = 1;
+	} else {
+		currcons--;
+		viewed = 0;
+	}
+	ret = -ENXIO;
+	if (!vc_cons_allocated(currcons))
+		goto unlock_out;
+	vc = vc_cons[currcons].d;
+
+	ret = -EINVAL;
+	if (pos < 0)
+		goto unlock_out;
+	poll = file->private_data;
+	if (count && poll)
+		poll->seen_last_update = true;
+	read = 0;
+	ret = 0;
+	while (count) {
+		char *con_buf0, *con_buf_start;
+		long this_round, size;
+		ssize_t orig_count;
+		long p = pos;
+
+		/* Check whether we are above size each round,
+		 * as copy_to_user at the end of this loop
+		 * could sleep.
+		 */
+		size = vcs_size(inode);
+		if (pos >= size)
+			break;
+		if (count > size - pos)
+			count = size - pos;
+
+		this_round = count;
+		if (this_round > CON_BUF_SIZE)
+			this_round = CON_BUF_SIZE;
+
+		/* Perform the whole read into the local con_buf.
+		 * Then we can drop the console spinlock and safely
+		 * attempt to move it to userspace.
+		 */
+
+		con_buf_start = con_buf0 = con_buf;
+		orig_count = this_round;
+		maxcol = vc->vc_cols;
+		if (!attr) {
+			org = screen_pos(vc, p, viewed);
+			col = p % maxcol;
+			p += maxcol - col;
+			while (this_round-- > 0) {
+				*con_buf0++ = (vcs_scr_readw(vc, org++) & 0xff);
+				if (++col == maxcol) {
+					org = screen_pos(vc, p, viewed);
+					col = 0;
+					p += maxcol;
+				}
+			}
+		} else {
+			if (p < HEADER_SIZE) {
+				size_t tmp_count;
+
+				con_buf0[0] = (char)vc->vc_rows;
+				con_buf0[1] = (char)vc->vc_cols;
+				getconsxy(vc, con_buf0 + 2);
+
+				con_buf_start += p;
+				this_round += p;
+				if (this_round > CON_BUF_SIZE) {
+					this_round = CON_BUF_SIZE;
+					orig_count = this_round - p;
+				}
+
+				tmp_count = HEADER_SIZE;
+				if (tmp_count > this_round)
+					tmp_count = this_round;
+
+				/* Advance state pointers and move on. */
+				this_round -= tmp_count;
+				p = HEADER_SIZE;
+				con_buf0 = con_buf + HEADER_SIZE;
+				/* If this_round >= 0, then p is even... */
+			} else if (p & 1) {
+				/* Skip first byte for output if start address is odd
+				 * Update region sizes up/down depending on free
+				 * space in buffer.
+				 */
+				con_buf_start++;
+				if (this_round < CON_BUF_SIZE)
+					this_round++;
+				else
+					orig_count--;
+			}
+			if (this_round > 0) {
+				unsigned short *tmp_buf = (unsigned short *)con_buf0;
+
+				p -= HEADER_SIZE;
+				p /= 2;
+				col = p % maxcol;
+
+				org = screen_pos(vc, p, viewed);
+				p += maxcol - col;
+
+				/* Buffer has even length, so we can always copy
+				 * character + attribute. We do not copy last byte
+				 * to userspace if this_round is odd.
+				 */
+				this_round = (this_round + 1) >> 1;
+
+				while (this_round) {
+					*tmp_buf++ = vcs_scr_readw(vc, org++);
+					this_round --;
+					if (++col == maxcol) {
+						org = screen_pos(vc, p, viewed);
+						col = 0;
+						p += maxcol;
+					}
+				}
+			}
+		}
+
+		/* Finally, release the console semaphore while we push
+		 * all the data to userspace from our temporary buffer.
+		 *
+		 * AKPM: Even though it's a semaphore, we should drop it because
+		 * the pagefault handling code may want to call printk().
+		 */
+
+		release_console_sem();
+		ret = copy_to_user(buf, con_buf_start, orig_count);
+		acquire_console_sem();
+
+		if (ret) {
+			read += (orig_count - ret);
+			ret = -EFAULT;
+			break;
+		}
+		buf += orig_count;
+		pos += orig_count;
+		read += orig_count;
+		count -= orig_count;
+	}
+	*ppos += read;
+	if (read)
+		ret = read;
+unlock_out:
+	release_console_sem();
+	mutex_unlock(&con_buf_mtx);
+	return ret;
+}
+
+static ssize_t
+vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	unsigned int currcons = iminor(inode);
+	struct vc_data *vc;
+	long pos;
+	long viewed, attr, size, written;
+	char *con_buf0;
+	int col, maxcol;
+	u16 *org0 = NULL, *org = NULL;
+	size_t ret;
+
+	mutex_lock(&con_buf_mtx);
+
+	pos = *ppos;
+
+	/* Select the proper current console and verify
+	 * sanity of the situation under the console lock.
+	 */
+	acquire_console_sem();
+
+	attr = (currcons & 128);
+	currcons = (currcons & 127);
+
+	if (currcons == 0) {
+		currcons = fg_console;
+		viewed = 1;
+	} else {
+		currcons--;
+		viewed = 0;
+	}
+	ret = -ENXIO;
+	if (!vc_cons_allocated(currcons))
+		goto unlock_out;
+	vc = vc_cons[currcons].d;
+
+	size = vcs_size(inode);
+	ret = -EINVAL;
+	if (pos < 0 || pos > size)
+		goto unlock_out;
+	if (count > size - pos)
+		count = size - pos;
+	written = 0;
+	while (count) {
+		long this_round = count;
+		size_t orig_count;
+		long p;
+
+		if (this_round > CON_BUF_SIZE)
+			this_round = CON_BUF_SIZE;
+
+		/* Temporarily drop the console lock so that we can read
+		 * in the write data from userspace safely.
+		 */
+		release_console_sem();
+		ret = copy_from_user(con_buf, buf, this_round);
+		acquire_console_sem();
+
+		if (ret) {
+			this_round -= ret;
+			if (!this_round) {
+				/* Abort loop if no data were copied. Otherwise
+				 * fail with -EFAULT.
+				 */
+				if (written)
+					break;
+				ret = -EFAULT;
+				goto unlock_out;
+			}
+		}
+
+		/* The vcs_size might have changed while we slept to grab
+		 * the user buffer, so recheck.
+		 * Return data written up to now on failure.
+		 */
+		size = vcs_size(inode);
+		if (pos >= size)
+			break;
+		if (this_round > size - pos)
+			this_round = size - pos;
+
+		/* OK, now actually push the write to the console
+		 * under the lock using the local kernel buffer.
+		 */
+
+		con_buf0 = con_buf;
+		orig_count = this_round;
+		maxcol = vc->vc_cols;
+		p = pos;
+		if (!attr) {
+			org0 = org = screen_pos(vc, p, viewed);
+			col = p % maxcol;
+			p += maxcol - col;
+
+			while (this_round > 0) {
+				unsigned char c = *con_buf0++;
+
+				this_round--;
+				vcs_scr_writew(vc,
+					       (vcs_scr_readw(vc, org) & 0xff00) | c, org);
+				org++;
+				if (++col == maxcol) {
+					org = screen_pos(vc, p, viewed);
+					col = 0;
+					p += maxcol;
+				}
+			}
+		} else {
+			if (p < HEADER_SIZE) {
+				char header[HEADER_SIZE];
+
+				getconsxy(vc, header + 2);
+				while (p < HEADER_SIZE && this_round > 0) {
+					this_round--;
+					header[p++] = *con_buf0++;
+				}
+				if (!viewed)
+					putconsxy(vc, header + 2);
+			}
+			p -= HEADER_SIZE;
+			col = (p/2) % maxcol;
+			if (this_round > 0) {
+				org0 = org = screen_pos(vc, p/2, viewed);
+				if ((p & 1) && this_round > 0) {
+					char c;
+
+					this_round--;
+					c = *con_buf0++;
+#ifdef __BIG_ENDIAN
+					vcs_scr_writew(vc, c |
+					     (vcs_scr_readw(vc, org) & 0xff00), org);
+#else
+					vcs_scr_writew(vc, (c << 8) |
+					     (vcs_scr_readw(vc, org) & 0xff), org);
+#endif
+					org++;
+					p++;
+					if (++col == maxcol) {
+						org = screen_pos(vc, p/2, viewed);
+						col = 0;
+					}
+				}
+				p /= 2;
+				p += maxcol - col;
+			}
+			while (this_round > 1) {
+				unsigned short w;
+
+				w = get_unaligned(((unsigned short *)con_buf0));
+				vcs_scr_writew(vc, w, org++);
+				con_buf0 += 2;
+				this_round -= 2;
+				if (++col == maxcol) {
+					org = screen_pos(vc, p, viewed);
+					col = 0;
+					p += maxcol;
+				}
+			}
+			if (this_round > 0) {
+				unsigned char c;
+
+				c = *con_buf0++;
+#ifdef __BIG_ENDIAN
+				vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff) | (c << 8), org);
+#else
+				vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff00) | c, org);
+#endif
+			}
+		}
+		count -= orig_count;
+		written += orig_count;
+		buf += orig_count;
+		pos += orig_count;
+		if (org0)
+			update_region(vc, (unsigned long)(org0), org - org0);
+	}
+	*ppos += written;
+	ret = written;
+	if (written)
+		vcs_scr_updated(vc);
+
+unlock_out:
+	release_console_sem();
+
+	mutex_unlock(&con_buf_mtx);
+
+	return ret;
+}
+
+static unsigned int
+vcs_poll(struct file *file, poll_table *wait)
+{
+	struct vcs_poll_data *poll = vcs_poll_data_get(file);
+	int ret = DEFAULT_POLLMASK|POLLERR|POLLPRI;
+
+	if (poll) {
+		poll_wait(file, &poll->waitq, wait);
+		if (poll->seen_last_update)
+			ret = DEFAULT_POLLMASK;
+	}
+	return ret;
+}
+
+static int
+vcs_fasync(int fd, struct file *file, int on)
+{
+	struct vcs_poll_data *poll = file->private_data;
+
+	if (!poll) {
+		/* don't allocate anything if all we want is disable fasync */
+		if (!on)
+			return 0;
+		poll = vcs_poll_data_get(file);
+		if (!poll)
+			return -ENOMEM;
+	}
+
+	return fasync_helper(fd, file, on, &poll->fasync);
+}
+
+static int
+vcs_open(struct inode *inode, struct file *filp)
+{
+	unsigned int currcons = iminor(inode) & 127;
+	int ret = 0;
+	
+	tty_lock();
+	if(currcons && !vc_cons_allocated(currcons-1))
+		ret = -ENXIO;
+	tty_unlock();
+	return ret;
+}
+
+static int vcs_release(struct inode *inode, struct file *file)
+{
+	struct vcs_poll_data *poll = file->private_data;
+
+	if (poll)
+		vcs_poll_data_free(poll);
+	return 0;
+}
+
+static const struct file_operations vcs_fops = {
+	.llseek		= vcs_lseek,
+	.read		= vcs_read,
+	.write		= vcs_write,
+	.poll		= vcs_poll,
+	.fasync		= vcs_fasync,
+	.open		= vcs_open,
+	.release	= vcs_release,
+};
+
+static struct class *vc_class;
+
+void vcs_make_sysfs(int index)
+{
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 1), NULL,
+		      "vcs%u", index + 1);
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, index + 129), NULL,
+		      "vcsa%u", index + 1);
+}
+
+void vcs_remove_sysfs(int index)
+{
+	device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 1));
+	device_destroy(vc_class, MKDEV(VCS_MAJOR, index + 129));
+}
+
+int __init vcs_init(void)
+{
+	unsigned int i;
+
+	if (register_chrdev(VCS_MAJOR, "vcs", &vcs_fops))
+		panic("unable to get major %d for vcs device", VCS_MAJOR);
+	vc_class = class_create(THIS_MODULE, "vc");
+
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 0), NULL, "vcs");
+	device_create(vc_class, NULL, MKDEV(VCS_MAJOR, 128), NULL, "vcsa");
+	for (i = 0; i < MIN_NR_CONSOLES; i++)
+		vcs_make_sysfs(i);
+	return 0;
+}
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
new file mode 100644
index 0000000..a8ec48e
--- /dev/null
+++ b/drivers/tty/vt/vt.c
@@ -0,0 +1,4209 @@
+/*
+ *  linux/drivers/char/vt.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+/*
+ * Hopefully this will be a rather complete VT102 implementation.
+ *
+ * Beeping thanks to John T Kohl.
+ *
+ * Virtual Consoles, Screen Blanking, Screen Dumping, Color, Graphics
+ *   Chars, and VT100 enhancements by Peter MacDonald.
+ *
+ * Copy and paste function by Andrew Haylett,
+ *   some enhancements by Alessandro Rubini.
+ *
+ * Code to check for different video-cards mostly by Galen Hunt,
+ * <g-hunt@ee.utah.edu>
+ *
+ * Rudimentary ISO 10646/Unicode/UTF-8 character set support by
+ * Markus Kuhn, <mskuhn@immd4.informatik.uni-erlangen.de>.
+ *
+ * Dynamic allocation of consoles, aeb@cwi.nl, May 1994
+ * Resizing of consoles, aeb, 940926
+ *
+ * Code for xterm like mouse click reporting by Peter Orbaek 20-Jul-94
+ * <poe@daimi.aau.dk>
+ *
+ * User-defined bell sound, new setterm control sequences and printk
+ * redirection by Martin Mares <mj@k332.feld.cvut.cz> 19-Nov-95
+ *
+ * APM screenblank bug fixed Takashi Manabe <manabe@roy.dsl.tutics.tut.jp>
+ *
+ * Merge with the abstract console driver by Geert Uytterhoeven
+ * <geert@linux-m68k.org>, Jan 1997.
+ *
+ *   Original m68k console driver modifications by
+ *
+ *     - Arno Griffioen <arno@usn.nl>
+ *     - David Carter <carter@cs.bris.ac.uk>
+ * 
+ *   The abstract console driver provides a generic interface for a text
+ *   console. It supports VGA text mode, frame buffer based graphical consoles
+ *   and special graphics processors that are only accessible through some
+ *   registers (e.g. a TMS340x0 GSP).
+ *
+ *   The interface to the hardware is specified using a special structure
+ *   (struct consw) which contains function pointers to console operations
+ *   (see <linux/console.h> for more information).
+ *
+ * Support for changeable cursor shape
+ * by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>, August 1997
+ *
+ * Ported to i386 and con_scrolldelta fixed
+ * by Emmanuel Marty <core@ggi-project.org>, April 1998
+ *
+ * Resurrected character buffers in videoram plus lots of other trickery
+ * by Martin Mares <mj@atrey.karlin.mff.cuni.cz>, July 1998
+ *
+ * Removed old-style timers, introduced console_timer, made timer
+ * deletion SMP-safe.  17Jun00, Andrew Morton
+ *
+ * Removed console_lock, enabled interrupts across all console operations
+ * 13 March 2001, Andrew Morton
+ *
+ * Fixed UTF-8 mode so alternate charset modes always work according
+ * to control sequences interpreted in do_con_trol function
+ * preserving backward VT100 semigraphics compatibility,
+ * malformed UTF sequences represented as sequences of replacement glyphs,
+ * original codes or '?' as a last resort if replacement glyph is undefined
+ * by Adam Tla/lka <atlka@pg.gda.pl>, Aug 2006
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/kd.h>
+#include <linux/slab.h>
+#include <linux/major.h>
+#include <linux/mm.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+#include <linux/smp_lock.h>
+#include <linux/tiocl.h>
+#include <linux/kbd_kern.h>
+#include <linux/consolemap.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/pm.h>
+#include <linux/font.h>
+#include <linux/bitops.h>
+#include <linux/notifier.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <asm/system.h>
+#include <linux/uaccess.h>
+#include <linux/kdb.h>
+#include <linux/ctype.h>
+
+#define MAX_NR_CON_DRIVER 16
+
+#define CON_DRIVER_FLAG_MODULE 1
+#define CON_DRIVER_FLAG_INIT   2
+#define CON_DRIVER_FLAG_ATTR   4
+
+struct con_driver {
+	const struct consw *con;
+	const char *desc;
+	struct device *dev;
+	int node;
+	int first;
+	int last;
+	int flag;
+};
+
+static struct con_driver registered_con_driver[MAX_NR_CON_DRIVER];
+const struct consw *conswitchp;
+
+/* A bitmap for codes <32. A bit of 1 indicates that the code
+ * corresponding to that bit number invokes some special action
+ * (such as cursor movement) and should not be displayed as a
+ * glyph unless the disp_ctrl mode is explicitly enabled.
+ */
+#define CTRL_ACTION 0x0d00ff81
+#define CTRL_ALWAYS 0x0800f501	/* Cannot be overridden by disp_ctrl */
+
+/*
+ * Here is the default bell parameters: 750HZ, 1/8th of a second
+ */
+#define DEFAULT_BELL_PITCH	750
+#define DEFAULT_BELL_DURATION	(HZ/8)
+
+struct vc vc_cons [MAX_NR_CONSOLES];
+
+#ifndef VT_SINGLE_DRIVER
+static const struct consw *con_driver_map[MAX_NR_CONSOLES];
+#endif
+
+static int con_open(struct tty_struct *, struct file *);
+static void vc_init(struct vc_data *vc, unsigned int rows,
+		    unsigned int cols, int do_clear);
+static void gotoxy(struct vc_data *vc, int new_x, int new_y);
+static void save_cur(struct vc_data *vc);
+static void reset_terminal(struct vc_data *vc, int do_clear);
+static void con_flush_chars(struct tty_struct *tty);
+static int set_vesa_blanking(char __user *p);
+static void set_cursor(struct vc_data *vc);
+static void hide_cursor(struct vc_data *vc);
+static void console_callback(struct work_struct *ignored);
+static void blank_screen_t(unsigned long dummy);
+static void set_palette(struct vc_data *vc);
+
+static int printable;		/* Is console ready for printing? */
+int default_utf8 = true;
+module_param(default_utf8, int, S_IRUGO | S_IWUSR);
+int global_cursor_default = -1;
+module_param(global_cursor_default, int, S_IRUGO | S_IWUSR);
+
+static int cur_default = CUR_DEFAULT;
+module_param(cur_default, int, S_IRUGO | S_IWUSR);
+
+/*
+ * ignore_poke: don't unblank the screen when things are typed.  This is
+ * mainly for the privacy of braille terminal users.
+ */
+static int ignore_poke;
+
+int do_poke_blanked_console;
+int console_blanked;
+
+static int vesa_blank_mode; /* 0:none 1:suspendV 2:suspendH 3:powerdown */
+static int vesa_off_interval;
+static int blankinterval = 10*60;
+core_param(consoleblank, blankinterval, int, 0444);
+
+static DECLARE_WORK(console_work, console_callback);
+
+/*
+ * fg_console is the current virtual console,
+ * last_console is the last used one,
+ * want_console is the console we want to switch to,
+ * saved_* variants are for save/restore around kernel debugger enter/leave
+ */
+int fg_console;
+int last_console;
+int want_console = -1;
+static int saved_fg_console;
+static int saved_last_console;
+static int saved_want_console;
+static int saved_vc_mode;
+static int saved_console_blanked;
+
+/*
+ * For each existing display, we have a pointer to console currently visible
+ * on that display, allowing consoles other than fg_console to be refreshed
+ * appropriately. Unless the low-level driver supplies its own display_fg
+ * variable, we use this one for the "master display".
+ */
+static struct vc_data *master_display_fg;
+
+/*
+ * Unfortunately, we need to delay tty echo when we're currently writing to the
+ * console since the code is (and always was) not re-entrant, so we schedule
+ * all flip requests to process context with schedule-task() and run it from
+ * console_callback().
+ */
+
+/*
+ * For the same reason, we defer scrollback to the console callback.
+ */
+static int scrollback_delta;
+
+/*
+ * Hook so that the power management routines can (un)blank
+ * the console on our behalf.
+ */
+int (*console_blank_hook)(int);
+
+static DEFINE_TIMER(console_timer, blank_screen_t, 0, 0);
+static int blank_state;
+static int blank_timer_expired;
+enum {
+	blank_off = 0,
+	blank_normal_wait,
+	blank_vesa_wait,
+};
+
+/*
+ * Notifier list for console events.
+ */
+static ATOMIC_NOTIFIER_HEAD(vt_notifier_list);
+
+int register_vt_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&vt_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(register_vt_notifier);
+
+int unregister_vt_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&vt_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_vt_notifier);
+
+static void notify_write(struct vc_data *vc, unsigned int unicode)
+{
+	struct vt_notifier_param param = { .vc = vc, unicode = unicode };
+	atomic_notifier_call_chain(&vt_notifier_list, VT_WRITE, &param);
+}
+
+static void notify_update(struct vc_data *vc)
+{
+	struct vt_notifier_param param = { .vc = vc };
+	atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, &param);
+}
+/*
+ *	Low-Level Functions
+ */
+
+#define IS_FG(vc)	((vc)->vc_num == fg_console)
+
+#ifdef VT_BUF_VRAM_ONLY
+#define DO_UPDATE(vc)	0
+#else
+#define DO_UPDATE(vc)	(CON_IS_VISIBLE(vc) && !console_blanked)
+#endif
+
+static inline unsigned short *screenpos(struct vc_data *vc, int offset, int viewed)
+{
+	unsigned short *p;
+	
+	if (!viewed)
+		p = (unsigned short *)(vc->vc_origin + offset);
+	else if (!vc->vc_sw->con_screen_pos)
+		p = (unsigned short *)(vc->vc_visible_origin + offset);
+	else
+		p = vc->vc_sw->con_screen_pos(vc, offset);
+	return p;
+}
+
+/* Called  from the keyboard irq path.. */
+static inline void scrolldelta(int lines)
+{
+	/* FIXME */
+	/* scrolldelta needs some kind of consistency lock, but the BKL was
+	   and still is not protecting versus the scheduled back end */
+	scrollback_delta += lines;
+	schedule_console_callback();
+}
+
+void schedule_console_callback(void)
+{
+	schedule_work(&console_work);
+}
+
+static void scrup(struct vc_data *vc, unsigned int t, unsigned int b, int nr)
+{
+	unsigned short *d, *s;
+
+	if (t+nr >= b)
+		nr = b - t - 1;
+	if (b > vc->vc_rows || t >= b || nr < 1)
+		return;
+	if (CON_IS_VISIBLE(vc) && vc->vc_sw->con_scroll(vc, t, b, SM_UP, nr))
+		return;
+	d = (unsigned short *)(vc->vc_origin + vc->vc_size_row * t);
+	s = (unsigned short *)(vc->vc_origin + vc->vc_size_row * (t + nr));
+	scr_memmovew(d, s, (b - t - nr) * vc->vc_size_row);
+	scr_memsetw(d + (b - t - nr) * vc->vc_cols, vc->vc_video_erase_char,
+		    vc->vc_size_row * nr);
+}
+
+static void scrdown(struct vc_data *vc, unsigned int t, unsigned int b, int nr)
+{
+	unsigned short *s;
+	unsigned int step;
+
+	if (t+nr >= b)
+		nr = b - t - 1;
+	if (b > vc->vc_rows || t >= b || nr < 1)
+		return;
+	if (CON_IS_VISIBLE(vc) && vc->vc_sw->con_scroll(vc, t, b, SM_DOWN, nr))
+		return;
+	s = (unsigned short *)(vc->vc_origin + vc->vc_size_row * t);
+	step = vc->vc_cols * nr;
+	scr_memmovew(s + step, s, (b - t - nr) * vc->vc_size_row);
+	scr_memsetw(s, vc->vc_video_erase_char, 2 * step);
+}
+
+static void do_update_region(struct vc_data *vc, unsigned long start, int count)
+{
+#ifndef VT_BUF_VRAM_ONLY
+	unsigned int xx, yy, offset;
+	u16 *p;
+
+	p = (u16 *) start;
+	if (!vc->vc_sw->con_getxy) {
+		offset = (start - vc->vc_origin) / 2;
+		xx = offset % vc->vc_cols;
+		yy = offset / vc->vc_cols;
+	} else {
+		int nxx, nyy;
+		start = vc->vc_sw->con_getxy(vc, start, &nxx, &nyy);
+		xx = nxx; yy = nyy;
+	}
+	for(;;) {
+		u16 attrib = scr_readw(p) & 0xff00;
+		int startx = xx;
+		u16 *q = p;
+		while (xx < vc->vc_cols && count) {
+			if (attrib != (scr_readw(p) & 0xff00)) {
+				if (p > q)
+					vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
+				startx = xx;
+				q = p;
+				attrib = scr_readw(p) & 0xff00;
+			}
+			p++;
+			xx++;
+			count--;
+		}
+		if (p > q)
+			vc->vc_sw->con_putcs(vc, q, p-q, yy, startx);
+		if (!count)
+			break;
+		xx = 0;
+		yy++;
+		if (vc->vc_sw->con_getxy) {
+			p = (u16 *)start;
+			start = vc->vc_sw->con_getxy(vc, start, NULL, NULL);
+		}
+	}
+#endif
+}
+
+void update_region(struct vc_data *vc, unsigned long start, int count)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (DO_UPDATE(vc)) {
+		hide_cursor(vc);
+		do_update_region(vc, start, count);
+		set_cursor(vc);
+	}
+}
+
+/* Structure of attributes is hardware-dependent */
+
+static u8 build_attr(struct vc_data *vc, u8 _color, u8 _intensity, u8 _blink,
+    u8 _underline, u8 _reverse, u8 _italic)
+{
+	if (vc->vc_sw->con_build_attr)
+		return vc->vc_sw->con_build_attr(vc, _color, _intensity,
+		       _blink, _underline, _reverse, _italic);
+
+#ifndef VT_BUF_VRAM_ONLY
+/*
+ * ++roman: I completely changed the attribute format for monochrome
+ * mode (!can_do_color). The formerly used MDA (monochrome display
+ * adapter) format didn't allow the combination of certain effects.
+ * Now the attribute is just a bit vector:
+ *  Bit 0..1: intensity (0..2)
+ *  Bit 2   : underline
+ *  Bit 3   : reverse
+ *  Bit 7   : blink
+ */
+	{
+	u8 a = _color;
+	if (!vc->vc_can_do_color)
+		return _intensity |
+		       (_italic ? 2 : 0) |
+		       (_underline ? 4 : 0) |
+		       (_reverse ? 8 : 0) |
+		       (_blink ? 0x80 : 0);
+	if (_italic)
+		a = (a & 0xF0) | vc->vc_itcolor;
+	else if (_underline)
+		a = (a & 0xf0) | vc->vc_ulcolor;
+	else if (_intensity == 0)
+		a = (a & 0xf0) | vc->vc_ulcolor;
+	if (_reverse)
+		a = ((a) & 0x88) | ((((a) >> 4) | ((a) << 4)) & 0x77);
+	if (_blink)
+		a ^= 0x80;
+	if (_intensity == 2)
+		a ^= 0x08;
+	if (vc->vc_hi_font_mask == 0x100)
+		a <<= 1;
+	return a;
+	}
+#else
+	return 0;
+#endif
+}
+
+static void update_attr(struct vc_data *vc)
+{
+	vc->vc_attr = build_attr(vc, vc->vc_color, vc->vc_intensity,
+	              vc->vc_blink, vc->vc_underline,
+	              vc->vc_reverse ^ vc->vc_decscnm, vc->vc_italic);
+	vc->vc_video_erase_char = (build_attr(vc, vc->vc_color, 1, vc->vc_blink, 0, vc->vc_decscnm, 0) << 8) | ' ';
+}
+
+/* Note: inverting the screen twice should revert to the original state */
+void invert_screen(struct vc_data *vc, int offset, int count, int viewed)
+{
+	unsigned short *p;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	count /= 2;
+	p = screenpos(vc, offset, viewed);
+	if (vc->vc_sw->con_invert_region)
+		vc->vc_sw->con_invert_region(vc, p, count);
+#ifndef VT_BUF_VRAM_ONLY
+	else {
+		u16 *q = p;
+		int cnt = count;
+		u16 a;
+
+		if (!vc->vc_can_do_color) {
+			while (cnt--) {
+			    a = scr_readw(q);
+			    a ^= 0x0800;
+			    scr_writew(a, q);
+			    q++;
+			}
+		} else if (vc->vc_hi_font_mask == 0x100) {
+			while (cnt--) {
+				a = scr_readw(q);
+				a = ((a) & 0x11ff) | (((a) & 0xe000) >> 4) | (((a) & 0x0e00) << 4);
+				scr_writew(a, q);
+				q++;
+			}
+		} else {
+			while (cnt--) {
+				a = scr_readw(q);
+				a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) | (((a) & 0x0700) << 4);
+				scr_writew(a, q);
+				q++;
+			}
+		}
+	}
+#endif
+	if (DO_UPDATE(vc))
+		do_update_region(vc, (unsigned long) p, count);
+}
+
+/* used by selection: complement pointer position */
+void complement_pos(struct vc_data *vc, int offset)
+{
+	static int old_offset = -1;
+	static unsigned short old;
+	static unsigned short oldx, oldy;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (old_offset != -1 && old_offset >= 0 &&
+	    old_offset < vc->vc_screenbuf_size) {
+		scr_writew(old, screenpos(vc, old_offset, 1));
+		if (DO_UPDATE(vc))
+			vc->vc_sw->con_putc(vc, old, oldy, oldx);
+	}
+
+	old_offset = offset;
+
+	if (offset != -1 && offset >= 0 &&
+	    offset < vc->vc_screenbuf_size) {
+		unsigned short new;
+		unsigned short *p;
+		p = screenpos(vc, offset, 1);
+		old = scr_readw(p);
+		new = old ^ vc->vc_complement_mask;
+		scr_writew(new, p);
+		if (DO_UPDATE(vc)) {
+			oldx = (offset >> 1) % vc->vc_cols;
+			oldy = (offset >> 1) / vc->vc_cols;
+			vc->vc_sw->con_putc(vc, new, oldy, oldx);
+		}
+	}
+
+}
+
+static void insert_char(struct vc_data *vc, unsigned int nr)
+{
+	unsigned short *p, *q = (unsigned short *)vc->vc_pos;
+
+	p = q + vc->vc_cols - nr - vc->vc_x;
+	while (--p >= q)
+		scr_writew(scr_readw(p), p + nr);
+	scr_memsetw(q, vc->vc_video_erase_char, nr * 2);
+	vc->vc_need_wrap = 0;
+	if (DO_UPDATE(vc)) {
+		unsigned short oldattr = vc->vc_attr;
+		vc->vc_sw->con_bmove(vc, vc->vc_y, vc->vc_x, vc->vc_y, vc->vc_x + nr, 1,
+				     vc->vc_cols - vc->vc_x - nr);
+		vc->vc_attr = vc->vc_video_erase_char >> 8;
+		while (nr--)
+			vc->vc_sw->con_putc(vc, vc->vc_video_erase_char, vc->vc_y, vc->vc_x + nr);
+		vc->vc_attr = oldattr;
+	}
+}
+
+static void delete_char(struct vc_data *vc, unsigned int nr)
+{
+	unsigned int i = vc->vc_x;
+	unsigned short *p = (unsigned short *)vc->vc_pos;
+
+	while (++i <= vc->vc_cols - nr) {
+		scr_writew(scr_readw(p+nr), p);
+		p++;
+	}
+	scr_memsetw(p, vc->vc_video_erase_char, nr * 2);
+	vc->vc_need_wrap = 0;
+	if (DO_UPDATE(vc)) {
+		unsigned short oldattr = vc->vc_attr;
+		vc->vc_sw->con_bmove(vc, vc->vc_y, vc->vc_x + nr, vc->vc_y, vc->vc_x, 1,
+				     vc->vc_cols - vc->vc_x - nr);
+		vc->vc_attr = vc->vc_video_erase_char >> 8;
+		while (nr--)
+			vc->vc_sw->con_putc(vc, vc->vc_video_erase_char, vc->vc_y,
+				     vc->vc_cols - 1 - nr);
+		vc->vc_attr = oldattr;
+	}
+}
+
+static int softcursor_original;
+
+static void add_softcursor(struct vc_data *vc)
+{
+	int i = scr_readw((u16 *) vc->vc_pos);
+	u32 type = vc->vc_cursor_type;
+
+	if (! (type & 0x10)) return;
+	if (softcursor_original != -1) return;
+	softcursor_original = i;
+	i |= ((type >> 8) & 0xff00 );
+	i ^= ((type) & 0xff00 );
+	if ((type & 0x20) && ((softcursor_original & 0x7000) == (i & 0x7000))) i ^= 0x7000;
+	if ((type & 0x40) && ((i & 0x700) == ((i & 0x7000) >> 4))) i ^= 0x0700;
+	scr_writew(i, (u16 *) vc->vc_pos);
+	if (DO_UPDATE(vc))
+		vc->vc_sw->con_putc(vc, i, vc->vc_y, vc->vc_x);
+}
+
+static void hide_softcursor(struct vc_data *vc)
+{
+	if (softcursor_original != -1) {
+		scr_writew(softcursor_original, (u16 *)vc->vc_pos);
+		if (DO_UPDATE(vc))
+			vc->vc_sw->con_putc(vc, softcursor_original,
+					vc->vc_y, vc->vc_x);
+		softcursor_original = -1;
+	}
+}
+
+static void hide_cursor(struct vc_data *vc)
+{
+	if (vc == sel_cons)
+		clear_selection();
+	vc->vc_sw->con_cursor(vc, CM_ERASE);
+	hide_softcursor(vc);
+}
+
+static void set_cursor(struct vc_data *vc)
+{
+	if (!IS_FG(vc) || console_blanked ||
+	    vc->vc_mode == KD_GRAPHICS)
+		return;
+	if (vc->vc_deccm) {
+		if (vc == sel_cons)
+			clear_selection();
+		add_softcursor(vc);
+		if ((vc->vc_cursor_type & 0x0f) != 1)
+			vc->vc_sw->con_cursor(vc, CM_DRAW);
+	} else
+		hide_cursor(vc);
+}
+
+static void set_origin(struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (!CON_IS_VISIBLE(vc) ||
+	    !vc->vc_sw->con_set_origin ||
+	    !vc->vc_sw->con_set_origin(vc))
+		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
+	vc->vc_visible_origin = vc->vc_origin;
+	vc->vc_scr_end = vc->vc_origin + vc->vc_screenbuf_size;
+	vc->vc_pos = vc->vc_origin + vc->vc_size_row * vc->vc_y + 2 * vc->vc_x;
+}
+
+static inline void save_screen(struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (vc->vc_sw->con_save_screen)
+		vc->vc_sw->con_save_screen(vc);
+}
+
+/*
+ *	Redrawing of screen
+ */
+
+static void clear_buffer_attributes(struct vc_data *vc)
+{
+	unsigned short *p = (unsigned short *)vc->vc_origin;
+	int count = vc->vc_screenbuf_size / 2;
+	int mask = vc->vc_hi_font_mask | 0xff;
+
+	for (; count > 0; count--, p++) {
+		scr_writew((scr_readw(p)&mask) | (vc->vc_video_erase_char & ~mask), p);
+	}
+}
+
+void redraw_screen(struct vc_data *vc, int is_switch)
+{
+	int redraw = 0;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (!vc) {
+		/* strange ... */
+		/* printk("redraw_screen: tty %d not allocated ??\n", new_console+1); */
+		return;
+	}
+
+	if (is_switch) {
+		struct vc_data *old_vc = vc_cons[fg_console].d;
+		if (old_vc == vc)
+			return;
+		if (!CON_IS_VISIBLE(vc))
+			redraw = 1;
+		*vc->vc_display_fg = vc;
+		fg_console = vc->vc_num;
+		hide_cursor(old_vc);
+		if (!CON_IS_VISIBLE(old_vc)) {
+			save_screen(old_vc);
+			set_origin(old_vc);
+		}
+	} else {
+		hide_cursor(vc);
+		redraw = 1;
+	}
+
+	if (redraw) {
+		int update;
+		int old_was_color = vc->vc_can_do_color;
+
+		set_origin(vc);
+		update = vc->vc_sw->con_switch(vc);
+		set_palette(vc);
+		/*
+		 * If console changed from mono<->color, the best we can do
+		 * is to clear the buffer attributes. As it currently stands,
+		 * rebuilding new attributes from the old buffer is not doable
+		 * without overly complex code.
+		 */
+		if (old_was_color != vc->vc_can_do_color) {
+			update_attr(vc);
+			clear_buffer_attributes(vc);
+		}
+
+		/* Forcibly update if we're panicing */
+		if ((update && vc->vc_mode != KD_GRAPHICS) ||
+		    vt_force_oops_output(vc))
+			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
+	}
+	set_cursor(vc);
+	if (is_switch) {
+		set_leds();
+		compute_shiftstate();
+		notify_update(vc);
+	}
+}
+
+/*
+ *	Allocation, freeing and resizing of VTs.
+ */
+
+int vc_cons_allocated(unsigned int i)
+{
+	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
+}
+
+static void visual_init(struct vc_data *vc, int num, int init)
+{
+	/* ++Geert: vc->vc_sw->con_init determines console size */
+	if (vc->vc_sw)
+		module_put(vc->vc_sw->owner);
+	vc->vc_sw = conswitchp;
+#ifndef VT_SINGLE_DRIVER
+	if (con_driver_map[num])
+		vc->vc_sw = con_driver_map[num];
+#endif
+	__module_get(vc->vc_sw->owner);
+	vc->vc_num = num;
+	vc->vc_display_fg = &master_display_fg;
+	vc->vc_uni_pagedir_loc = &vc->vc_uni_pagedir;
+	vc->vc_uni_pagedir = 0;
+	vc->vc_hi_font_mask = 0;
+	vc->vc_complement_mask = 0;
+	vc->vc_can_do_color = 0;
+	vc->vc_panic_force_write = false;
+	vc->vc_sw->con_init(vc, init);
+	if (!vc->vc_complement_mask)
+		vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;
+	vc->vc_s_complement_mask = vc->vc_complement_mask;
+	vc->vc_size_row = vc->vc_cols << 1;
+	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
+}
+
+int vc_allocate(unsigned int currcons)	/* return 0 on success */
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (currcons >= MAX_NR_CONSOLES)
+		return -ENXIO;
+	if (!vc_cons[currcons].d) {
+	    struct vc_data *vc;
+	    struct vt_notifier_param param;
+
+	    /* prevent users from taking too much memory */
+	    if (currcons >= MAX_NR_USER_CONSOLES && !capable(CAP_SYS_RESOURCE))
+	      return -EPERM;
+
+	    /* due to the granularity of kmalloc, we waste some memory here */
+	    /* the alloc is done in two steps, to optimize the common situation
+	       of a 25x80 console (structsize=216, screenbuf_size=4000) */
+	    /* although the numbers above are not valid since long ago, the
+	       point is still up-to-date and the comment still has its value
+	       even if only as a historical artifact.  --mj, July 1998 */
+	    param.vc = vc = kzalloc(sizeof(struct vc_data), GFP_KERNEL);
+	    if (!vc)
+		return -ENOMEM;
+	    vc_cons[currcons].d = vc;
+	    tty_port_init(&vc->port);
+	    INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
+	    visual_init(vc, currcons, 1);
+	    if (!*vc->vc_uni_pagedir_loc)
+		con_set_default_unimap(vc);
+	    vc->vc_screenbuf = kmalloc(vc->vc_screenbuf_size, GFP_KERNEL);
+	    if (!vc->vc_screenbuf) {
+		kfree(vc);
+		vc_cons[currcons].d = NULL;
+		return -ENOMEM;
+	    }
+
+	    /* If no drivers have overridden us and the user didn't pass a
+	       boot option, default to displaying the cursor */
+	    if (global_cursor_default == -1)
+		    global_cursor_default = 1;
+
+	    vc_init(vc, vc->vc_rows, vc->vc_cols, 1);
+	    vcs_make_sysfs(currcons);
+	    atomic_notifier_call_chain(&vt_notifier_list, VT_ALLOCATE, &param);
+	}
+	return 0;
+}
+
+static inline int resize_screen(struct vc_data *vc, int width, int height,
+				int user)
+{
+	/* Resizes the resolution of the display adapater */
+	int err = 0;
+
+	if (vc->vc_mode != KD_GRAPHICS && vc->vc_sw->con_resize)
+		err = vc->vc_sw->con_resize(vc, width, height, user);
+
+	return err;
+}
+
+/*
+ * Change # of rows and columns (0 means unchanged/the size of fg_console)
+ * [this is to be used together with some user program
+ * like resize that changes the hardware videomode]
+ */
+#define VC_RESIZE_MAXCOL (32767)
+#define VC_RESIZE_MAXROW (32767)
+
+/**
+ *	vc_do_resize	-	resizing method for the tty
+ *	@tty: tty being resized
+ *	@real_tty: real tty (different to tty if a pty/tty pair)
+ *	@vc: virtual console private data
+ *	@cols: columns
+ *	@lines: lines
+ *
+ *	Resize a virtual console, clipping according to the actual constraints.
+ *	If the caller passes a tty structure then update the termios winsize
+ *	information and perform any necessary signal handling.
+ *
+ *	Caller must hold the console semaphore. Takes the termios mutex and
+ *	ctrl_lock of the tty IFF a tty is passed.
+ */
+
+static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
+				unsigned int cols, unsigned int lines)
+{
+	unsigned long old_origin, new_origin, new_scr_end, rlth, rrem, err = 0;
+	unsigned long end;
+	unsigned int old_cols, old_rows, old_row_size, old_screen_size;
+	unsigned int new_cols, new_rows, new_row_size, new_screen_size;
+	unsigned int user;
+	unsigned short *newscreen;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (!vc)
+		return -ENXIO;
+
+	user = vc->vc_resize_user;
+	vc->vc_resize_user = 0;
+
+	if (cols > VC_RESIZE_MAXCOL || lines > VC_RESIZE_MAXROW)
+		return -EINVAL;
+
+	new_cols = (cols ? cols : vc->vc_cols);
+	new_rows = (lines ? lines : vc->vc_rows);
+	new_row_size = new_cols << 1;
+	new_screen_size = new_row_size * new_rows;
+
+	if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
+		return 0;
+
+	newscreen = kmalloc(new_screen_size, GFP_USER);
+	if (!newscreen)
+		return -ENOMEM;
+
+	old_rows = vc->vc_rows;
+	old_cols = vc->vc_cols;
+	old_row_size = vc->vc_size_row;
+	old_screen_size = vc->vc_screenbuf_size;
+
+	err = resize_screen(vc, new_cols, new_rows, user);
+	if (err) {
+		kfree(newscreen);
+		return err;
+	}
+
+	vc->vc_rows = new_rows;
+	vc->vc_cols = new_cols;
+	vc->vc_size_row = new_row_size;
+	vc->vc_screenbuf_size = new_screen_size;
+
+	rlth = min(old_row_size, new_row_size);
+	rrem = new_row_size - rlth;
+	old_origin = vc->vc_origin;
+	new_origin = (long) newscreen;
+	new_scr_end = new_origin + new_screen_size;
+
+	if (vc->vc_y > new_rows) {
+		if (old_rows - vc->vc_y < new_rows) {
+			/*
+			 * Cursor near the bottom, copy contents from the
+			 * bottom of buffer
+			 */
+			old_origin += (old_rows - new_rows) * old_row_size;
+		} else {
+			/*
+			 * Cursor is in no man's land, copy 1/2 screenful
+			 * from the top and bottom of cursor position
+			 */
+			old_origin += (vc->vc_y - new_rows/2) * old_row_size;
+		}
+	}
+
+	end = old_origin + old_row_size * min(old_rows, new_rows);
+
+	update_attr(vc);
+
+	while (old_origin < end) {
+		scr_memcpyw((unsigned short *) new_origin,
+			    (unsigned short *) old_origin, rlth);
+		if (rrem)
+			scr_memsetw((void *)(new_origin + rlth),
+				    vc->vc_video_erase_char, rrem);
+		old_origin += old_row_size;
+		new_origin += new_row_size;
+	}
+	if (new_scr_end > new_origin)
+		scr_memsetw((void *)new_origin, vc->vc_video_erase_char,
+			    new_scr_end - new_origin);
+	kfree(vc->vc_screenbuf);
+	vc->vc_screenbuf = newscreen;
+	vc->vc_screenbuf_size = new_screen_size;
+	set_origin(vc);
+
+	/* do part of a reset_terminal() */
+	vc->vc_top = 0;
+	vc->vc_bottom = vc->vc_rows;
+	gotoxy(vc, vc->vc_x, vc->vc_y);
+	save_cur(vc);
+
+	if (tty) {
+		/* Rewrite the requested winsize data with the actual
+		   resulting sizes */
+		struct winsize ws;
+		memset(&ws, 0, sizeof(ws));
+		ws.ws_row = vc->vc_rows;
+		ws.ws_col = vc->vc_cols;
+		ws.ws_ypixel = vc->vc_scan_lines;
+		tty_do_resize(tty, &ws);
+	}
+
+	if (CON_IS_VISIBLE(vc))
+		update_screen(vc);
+	vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num);
+	return err;
+}
+
+/**
+ *	vc_resize		-	resize a VT
+ *	@vc: virtual console
+ *	@cols: columns
+ *	@rows: rows
+ *
+ *	Resize a virtual console as seen from the console end of things. We
+ *	use the common vc_do_resize methods to update the structures. The
+ *	caller must hold the console sem to protect console internals and
+ *	vc->port.tty
+ */
+
+int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int rows)
+{
+	return vc_do_resize(vc->port.tty, vc, cols, rows);
+}
+
+/**
+ *	vt_resize		-	resize a VT
+ *	@tty: tty to resize
+ *	@ws: winsize attributes
+ *
+ *	Resize a virtual terminal. This is called by the tty layer as we
+ *	register our own handler for resizing. The mutual helper does all
+ *	the actual work.
+ *
+ *	Takes the console sem and the called methods then take the tty
+ *	termios_mutex and the tty ctrl_lock in that order.
+ */
+static int vt_resize(struct tty_struct *tty, struct winsize *ws)
+{
+	struct vc_data *vc = tty->driver_data;
+	int ret;
+
+	acquire_console_sem();
+	ret = vc_do_resize(tty, vc, ws->ws_col, ws->ws_row);
+	release_console_sem();
+	return ret;
+}
+
+void vc_deallocate(unsigned int currcons)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (vc_cons_allocated(currcons)) {
+		struct vc_data *vc = vc_cons[currcons].d;
+		struct vt_notifier_param param = { .vc = vc };
+
+		atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
+		vcs_remove_sysfs(currcons);
+		vc->vc_sw->con_deinit(vc);
+		put_pid(vc->vt_pid);
+		module_put(vc->vc_sw->owner);
+		kfree(vc->vc_screenbuf);
+		if (currcons >= MIN_NR_CONSOLES)
+			kfree(vc);
+		vc_cons[currcons].d = NULL;
+	}
+}
+
+/*
+ *	VT102 emulator
+ */
+
+#define set_kbd(vc, x)	set_vc_kbd_mode(kbd_table + (vc)->vc_num, (x))
+#define clr_kbd(vc, x)	clr_vc_kbd_mode(kbd_table + (vc)->vc_num, (x))
+#define is_kbd(vc, x)	vc_kbd_mode(kbd_table + (vc)->vc_num, (x))
+
+#define decarm		VC_REPEAT
+#define decckm		VC_CKMODE
+#define kbdapplic	VC_APPLIC
+#define lnm		VC_CRLF
+
+/*
+ * this is what the terminal answers to a ESC-Z or csi0c query.
+ */
+#define VT100ID "\033[?1;2c"
+#define VT102ID "\033[?6c"
+
+unsigned char color_table[] = { 0, 4, 2, 6, 1, 5, 3, 7,
+				       8,12,10,14, 9,13,11,15 };
+
+/* the default colour table, for VGA+ colour systems */
+int default_red[] = {0x00,0xaa,0x00,0xaa,0x00,0xaa,0x00,0xaa,
+    0x55,0xff,0x55,0xff,0x55,0xff,0x55,0xff};
+int default_grn[] = {0x00,0x00,0xaa,0x55,0x00,0x00,0xaa,0xaa,
+    0x55,0x55,0xff,0xff,0x55,0x55,0xff,0xff};
+int default_blu[] = {0x00,0x00,0x00,0x00,0xaa,0xaa,0xaa,0xaa,
+    0x55,0x55,0x55,0x55,0xff,0xff,0xff,0xff};
+
+module_param_array(default_red, int, NULL, S_IRUGO | S_IWUSR);
+module_param_array(default_grn, int, NULL, S_IRUGO | S_IWUSR);
+module_param_array(default_blu, int, NULL, S_IRUGO | S_IWUSR);
+
+/*
+ * gotoxy() must verify all boundaries, because the arguments
+ * might also be negative. If the given position is out of
+ * bounds, the cursor is placed at the nearest margin.
+ */
+static void gotoxy(struct vc_data *vc, int new_x, int new_y)
+{
+	int min_y, max_y;
+
+	if (new_x < 0)
+		vc->vc_x = 0;
+	else {
+		if (new_x >= vc->vc_cols)
+			vc->vc_x = vc->vc_cols - 1;
+		else
+			vc->vc_x = new_x;
+	}
+
+ 	if (vc->vc_decom) {
+		min_y = vc->vc_top;
+		max_y = vc->vc_bottom;
+	} else {
+		min_y = 0;
+		max_y = vc->vc_rows;
+	}
+	if (new_y < min_y)
+		vc->vc_y = min_y;
+	else if (new_y >= max_y)
+		vc->vc_y = max_y - 1;
+	else
+		vc->vc_y = new_y;
+	vc->vc_pos = vc->vc_origin + vc->vc_y * vc->vc_size_row + (vc->vc_x<<1);
+	vc->vc_need_wrap = 0;
+}
+
+/* for absolute user moves, when decom is set */
+static void gotoxay(struct vc_data *vc, int new_x, int new_y)
+{
+	gotoxy(vc, new_x, vc->vc_decom ? (vc->vc_top + new_y) : new_y);
+}
+
+void scrollback(struct vc_data *vc, int lines)
+{
+	if (!lines)
+		lines = vc->vc_rows / 2;
+	scrolldelta(-lines);
+}
+
+void scrollfront(struct vc_data *vc, int lines)
+{
+	if (!lines)
+		lines = vc->vc_rows / 2;
+	scrolldelta(lines);
+}
+
+static void lf(struct vc_data *vc)
+{
+    	/* don't scroll if above bottom of scrolling region, or
+	 * if below scrolling region
+	 */
+    	if (vc->vc_y + 1 == vc->vc_bottom)
+		scrup(vc, vc->vc_top, vc->vc_bottom, 1);
+	else if (vc->vc_y < vc->vc_rows - 1) {
+	    	vc->vc_y++;
+		vc->vc_pos += vc->vc_size_row;
+	}
+	vc->vc_need_wrap = 0;
+	notify_write(vc, '\n');
+}
+
+static void ri(struct vc_data *vc)
+{
+    	/* don't scroll if below top of scrolling region, or
+	 * if above scrolling region
+	 */
+	if (vc->vc_y == vc->vc_top)
+		scrdown(vc, vc->vc_top, vc->vc_bottom, 1);
+	else if (vc->vc_y > 0) {
+		vc->vc_y--;
+		vc->vc_pos -= vc->vc_size_row;
+	}
+	vc->vc_need_wrap = 0;
+}
+
+static inline void cr(struct vc_data *vc)
+{
+	vc->vc_pos -= vc->vc_x << 1;
+	vc->vc_need_wrap = vc->vc_x = 0;
+	notify_write(vc, '\r');
+}
+
+static inline void bs(struct vc_data *vc)
+{
+	if (vc->vc_x) {
+		vc->vc_pos -= 2;
+		vc->vc_x--;
+		vc->vc_need_wrap = 0;
+		notify_write(vc, '\b');
+	}
+}
+
+static inline void del(struct vc_data *vc)
+{
+	/* ignored */
+}
+
+static void csi_J(struct vc_data *vc, int vpar)
+{
+	unsigned int count;
+	unsigned short * start;
+
+	switch (vpar) {
+		case 0:	/* erase from cursor to end of display */
+			count = (vc->vc_scr_end - vc->vc_pos) >> 1;
+			start = (unsigned short *)vc->vc_pos;
+			if (DO_UPDATE(vc)) {
+				/* do in two stages */
+				vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1,
+					      vc->vc_cols - vc->vc_x);
+				vc->vc_sw->con_clear(vc, vc->vc_y + 1, 0,
+					      vc->vc_rows - vc->vc_y - 1,
+					      vc->vc_cols);
+			}
+			break;
+		case 1:	/* erase from start to cursor */
+			count = ((vc->vc_pos - vc->vc_origin) >> 1) + 1;
+			start = (unsigned short *)vc->vc_origin;
+			if (DO_UPDATE(vc)) {
+				/* do in two stages */
+				vc->vc_sw->con_clear(vc, 0, 0, vc->vc_y,
+					      vc->vc_cols);
+				vc->vc_sw->con_clear(vc, vc->vc_y, 0, 1,
+					      vc->vc_x + 1);
+			}
+			break;
+		case 2: /* erase whole display */
+			count = vc->vc_cols * vc->vc_rows;
+			start = (unsigned short *)vc->vc_origin;
+			if (DO_UPDATE(vc))
+				vc->vc_sw->con_clear(vc, 0, 0,
+					      vc->vc_rows,
+					      vc->vc_cols);
+			break;
+		default:
+			return;
+	}
+	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
+	vc->vc_need_wrap = 0;
+}
+
+static void csi_K(struct vc_data *vc, int vpar)
+{
+	unsigned int count;
+	unsigned short * start;
+
+	switch (vpar) {
+		case 0:	/* erase from cursor to end of line */
+			count = vc->vc_cols - vc->vc_x;
+			start = (unsigned short *)vc->vc_pos;
+			if (DO_UPDATE(vc))
+				vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1,
+						     vc->vc_cols - vc->vc_x);
+			break;
+		case 1:	/* erase from start of line to cursor */
+			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
+			count = vc->vc_x + 1;
+			if (DO_UPDATE(vc))
+				vc->vc_sw->con_clear(vc, vc->vc_y, 0, 1,
+						     vc->vc_x + 1);
+			break;
+		case 2: /* erase whole line */
+			start = (unsigned short *)(vc->vc_pos - (vc->vc_x << 1));
+			count = vc->vc_cols;
+			if (DO_UPDATE(vc))
+				vc->vc_sw->con_clear(vc, vc->vc_y, 0, 1,
+					      vc->vc_cols);
+			break;
+		default:
+			return;
+	}
+	scr_memsetw(start, vc->vc_video_erase_char, 2 * count);
+	vc->vc_need_wrap = 0;
+}
+
+static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
+{					  /* not vt100? */
+	int count;
+
+	if (!vpar)
+		vpar++;
+	count = (vpar > vc->vc_cols - vc->vc_x) ? (vc->vc_cols - vc->vc_x) : vpar;
+
+	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
+	if (DO_UPDATE(vc))
+		vc->vc_sw->con_clear(vc, vc->vc_y, vc->vc_x, 1, count);
+	vc->vc_need_wrap = 0;
+}
+
+static void default_attr(struct vc_data *vc)
+{
+	vc->vc_intensity = 1;
+	vc->vc_italic = 0;
+	vc->vc_underline = 0;
+	vc->vc_reverse = 0;
+	vc->vc_blink = 0;
+	vc->vc_color = vc->vc_def_color;
+}
+
+/* console_sem is held */
+static void csi_m(struct vc_data *vc)
+{
+	int i;
+
+	for (i = 0; i <= vc->vc_npar; i++)
+		switch (vc->vc_par[i]) {
+			case 0:	/* all attributes off */
+				default_attr(vc);
+				break;
+			case 1:
+				vc->vc_intensity = 2;
+				break;
+			case 2:
+				vc->vc_intensity = 0;
+				break;
+			case 3:
+				vc->vc_italic = 1;
+				break;
+			case 4:
+				vc->vc_underline = 1;
+				break;
+			case 5:
+				vc->vc_blink = 1;
+				break;
+			case 7:
+				vc->vc_reverse = 1;
+				break;
+			case 10: /* ANSI X3.64-1979 (SCO-ish?)
+				  * Select primary font, don't display
+				  * control chars if defined, don't set
+				  * bit 8 on output.
+				  */
+				vc->vc_translate = set_translate(vc->vc_charset == 0
+						? vc->vc_G0_charset
+						: vc->vc_G1_charset, vc);
+				vc->vc_disp_ctrl = 0;
+				vc->vc_toggle_meta = 0;
+				break;
+			case 11: /* ANSI X3.64-1979 (SCO-ish?)
+				  * Select first alternate font, lets
+				  * chars < 32 be displayed as ROM chars.
+				  */
+				vc->vc_translate = set_translate(IBMPC_MAP, vc);
+				vc->vc_disp_ctrl = 1;
+				vc->vc_toggle_meta = 0;
+				break;
+			case 12: /* ANSI X3.64-1979 (SCO-ish?)
+				  * Select second alternate font, toggle
+				  * high bit before displaying as ROM char.
+				  */
+				vc->vc_translate = set_translate(IBMPC_MAP, vc);
+				vc->vc_disp_ctrl = 1;
+				vc->vc_toggle_meta = 1;
+				break;
+			case 21:
+			case 22:
+				vc->vc_intensity = 1;
+				break;
+			case 23:
+				vc->vc_italic = 0;
+				break;
+			case 24:
+				vc->vc_underline = 0;
+				break;
+			case 25:
+				vc->vc_blink = 0;
+				break;
+			case 27:
+				vc->vc_reverse = 0;
+				break;
+			case 38: /* ANSI X3.64-1979 (SCO-ish?)
+				  * Enables underscore, white foreground
+				  * with white underscore (Linux - use
+				  * default foreground).
+				  */
+				vc->vc_color = (vc->vc_def_color & 0x0f) | (vc->vc_color & 0xf0);
+				vc->vc_underline = 1;
+				break;
+			case 39: /* ANSI X3.64-1979 (SCO-ish?)
+				  * Disable underline option.
+				  * Reset colour to default? It did this
+				  * before...
+				  */
+				vc->vc_color = (vc->vc_def_color & 0x0f) | (vc->vc_color & 0xf0);
+				vc->vc_underline = 0;
+				break;
+			case 49:
+				vc->vc_color = (vc->vc_def_color & 0xf0) | (vc->vc_color & 0x0f);
+				break;
+			default:
+				if (vc->vc_par[i] >= 30 && vc->vc_par[i] <= 37)
+					vc->vc_color = color_table[vc->vc_par[i] - 30]
+						| (vc->vc_color & 0xf0);
+				else if (vc->vc_par[i] >= 40 && vc->vc_par[i] <= 47)
+					vc->vc_color = (color_table[vc->vc_par[i] - 40] << 4)
+						| (vc->vc_color & 0x0f);
+				break;
+		}
+	update_attr(vc);
+}
+
+static void respond_string(const char *p, struct tty_struct *tty)
+{
+	while (*p) {
+		tty_insert_flip_char(tty, *p, 0);
+		p++;
+	}
+	con_schedule_flip(tty);
+}
+
+static void cursor_report(struct vc_data *vc, struct tty_struct *tty)
+{
+	char buf[40];
+
+	sprintf(buf, "\033[%d;%dR", vc->vc_y + (vc->vc_decom ? vc->vc_top + 1 : 1), vc->vc_x + 1);
+	respond_string(buf, tty);
+}
+
+static inline void status_report(struct tty_struct *tty)
+{
+	respond_string("\033[0n", tty);	/* Terminal ok */
+}
+
+static inline void respond_ID(struct tty_struct * tty)
+{
+	respond_string(VT102ID, tty);
+}
+
+void mouse_report(struct tty_struct *tty, int butt, int mrx, int mry)
+{
+	char buf[8];
+
+	sprintf(buf, "\033[M%c%c%c", (char)(' ' + butt), (char)('!' + mrx),
+		(char)('!' + mry));
+	respond_string(buf, tty);
+}
+
+/* invoked via ioctl(TIOCLINUX) and through set_selection */
+int mouse_reporting(void)
+{
+	return vc_cons[fg_console].d->vc_report_mouse;
+}
+
+/* console_sem is held */
+static void set_mode(struct vc_data *vc, int on_off)
+{
+	int i;
+
+	for (i = 0; i <= vc->vc_npar; i++)
+		if (vc->vc_ques) {
+			switch(vc->vc_par[i]) {	/* DEC private modes set/reset */
+			case 1:			/* Cursor keys send ^[Ox/^[[x */
+				if (on_off)
+					set_kbd(vc, decckm);
+				else
+					clr_kbd(vc, decckm);
+				break;
+			case 3:	/* 80/132 mode switch unimplemented */
+				vc->vc_deccolm = on_off;
+#if 0
+				vc_resize(deccolm ? 132 : 80, vc->vc_rows);
+				/* this alone does not suffice; some user mode
+				   utility has to change the hardware regs */
+#endif
+				break;
+			case 5:			/* Inverted screen on/off */
+				if (vc->vc_decscnm != on_off) {
+					vc->vc_decscnm = on_off;
+					invert_screen(vc, 0, vc->vc_screenbuf_size, 0);
+					update_attr(vc);
+				}
+				break;
+			case 6:			/* Origin relative/absolute */
+				vc->vc_decom = on_off;
+				gotoxay(vc, 0, 0);
+				break;
+			case 7:			/* Autowrap on/off */
+				vc->vc_decawm = on_off;
+				break;
+			case 8:			/* Autorepeat on/off */
+				if (on_off)
+					set_kbd(vc, decarm);
+				else
+					clr_kbd(vc, decarm);
+				break;
+			case 9:
+				vc->vc_report_mouse = on_off ? 1 : 0;
+				break;
+			case 25:		/* Cursor on/off */
+				vc->vc_deccm = on_off;
+				break;
+			case 1000:
+				vc->vc_report_mouse = on_off ? 2 : 0;
+				break;
+			}
+		} else {
+			switch(vc->vc_par[i]) {	/* ANSI modes set/reset */
+			case 3:			/* Monitor (display ctrls) */
+				vc->vc_disp_ctrl = on_off;
+				break;
+			case 4:			/* Insert Mode on/off */
+				vc->vc_decim = on_off;
+				break;
+			case 20:		/* Lf, Enter == CrLf/Lf */
+				if (on_off)
+					set_kbd(vc, lnm);
+				else
+					clr_kbd(vc, lnm);
+				break;
+			}
+		}
+}
+
+/* console_sem is held */
+static void setterm_command(struct vc_data *vc)
+{
+	switch(vc->vc_par[0]) {
+		case 1:	/* set color for underline mode */
+			if (vc->vc_can_do_color &&
+					vc->vc_par[1] < 16) {
+				vc->vc_ulcolor = color_table[vc->vc_par[1]];
+				if (vc->vc_underline)
+					update_attr(vc);
+			}
+			break;
+		case 2:	/* set color for half intensity mode */
+			if (vc->vc_can_do_color &&
+					vc->vc_par[1] < 16) {
+				vc->vc_halfcolor = color_table[vc->vc_par[1]];
+				if (vc->vc_intensity == 0)
+					update_attr(vc);
+			}
+			break;
+		case 8:	/* store colors as defaults */
+			vc->vc_def_color = vc->vc_attr;
+			if (vc->vc_hi_font_mask == 0x100)
+				vc->vc_def_color >>= 1;
+			default_attr(vc);
+			update_attr(vc);
+			break;
+		case 9:	/* set blanking interval */
+			blankinterval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60;
+			poke_blanked_console();
+			break;
+		case 10: /* set bell frequency in Hz */
+			if (vc->vc_npar >= 1)
+				vc->vc_bell_pitch = vc->vc_par[1];
+			else
+				vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
+			break;
+		case 11: /* set bell duration in msec */
+			if (vc->vc_npar >= 1)
+				vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?
+					vc->vc_par[1] * HZ / 1000 : 0;
+			else
+				vc->vc_bell_duration = DEFAULT_BELL_DURATION;
+			break;
+		case 12: /* bring specified console to the front */
+			if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))
+				set_console(vc->vc_par[1] - 1);
+			break;
+		case 13: /* unblank the screen */
+			poke_blanked_console();
+			break;
+		case 14: /* set vesa powerdown interval */
+			vesa_off_interval = ((vc->vc_par[1] < 60) ? vc->vc_par[1] : 60) * 60 * HZ;
+			break;
+		case 15: /* activate the previous console */
+			set_console(last_console);
+			break;
+	}
+}
+
+/* console_sem is held */
+static void csi_at(struct vc_data *vc, unsigned int nr)
+{
+	if (nr > vc->vc_cols - vc->vc_x)
+		nr = vc->vc_cols - vc->vc_x;
+	else if (!nr)
+		nr = 1;
+	insert_char(vc, nr);
+}
+
+/* console_sem is held */
+static void csi_L(struct vc_data *vc, unsigned int nr)
+{
+	if (nr > vc->vc_rows - vc->vc_y)
+		nr = vc->vc_rows - vc->vc_y;
+	else if (!nr)
+		nr = 1;
+	scrdown(vc, vc->vc_y, vc->vc_bottom, nr);
+	vc->vc_need_wrap = 0;
+}
+
+/* console_sem is held */
+static void csi_P(struct vc_data *vc, unsigned int nr)
+{
+	if (nr > vc->vc_cols - vc->vc_x)
+		nr = vc->vc_cols - vc->vc_x;
+	else if (!nr)
+		nr = 1;
+	delete_char(vc, nr);
+}
+
+/* console_sem is held */
+static void csi_M(struct vc_data *vc, unsigned int nr)
+{
+	if (nr > vc->vc_rows - vc->vc_y)
+		nr = vc->vc_rows - vc->vc_y;
+	else if (!nr)
+		nr=1;
+	scrup(vc, vc->vc_y, vc->vc_bottom, nr);
+	vc->vc_need_wrap = 0;
+}
+
+/* console_sem is held (except via vc_init->reset_terminal */
+static void save_cur(struct vc_data *vc)
+{
+	vc->vc_saved_x		= vc->vc_x;
+	vc->vc_saved_y		= vc->vc_y;
+	vc->vc_s_intensity	= vc->vc_intensity;
+	vc->vc_s_italic         = vc->vc_italic;
+	vc->vc_s_underline	= vc->vc_underline;
+	vc->vc_s_blink		= vc->vc_blink;
+	vc->vc_s_reverse	= vc->vc_reverse;
+	vc->vc_s_charset	= vc->vc_charset;
+	vc->vc_s_color		= vc->vc_color;
+	vc->vc_saved_G0		= vc->vc_G0_charset;
+	vc->vc_saved_G1		= vc->vc_G1_charset;
+}
+
+/* console_sem is held */
+static void restore_cur(struct vc_data *vc)
+{
+	gotoxy(vc, vc->vc_saved_x, vc->vc_saved_y);
+	vc->vc_intensity	= vc->vc_s_intensity;
+	vc->vc_italic		= vc->vc_s_italic;
+	vc->vc_underline	= vc->vc_s_underline;
+	vc->vc_blink		= vc->vc_s_blink;
+	vc->vc_reverse		= vc->vc_s_reverse;
+	vc->vc_charset		= vc->vc_s_charset;
+	vc->vc_color		= vc->vc_s_color;
+	vc->vc_G0_charset	= vc->vc_saved_G0;
+	vc->vc_G1_charset	= vc->vc_saved_G1;
+	vc->vc_translate	= set_translate(vc->vc_charset ? vc->vc_G1_charset : vc->vc_G0_charset, vc);
+	update_attr(vc);
+	vc->vc_need_wrap = 0;
+}
+
+enum { ESnormal, ESesc, ESsquare, ESgetpars, ESgotpars, ESfunckey,
+	EShash, ESsetG0, ESsetG1, ESpercent, ESignore, ESnonstd,
+	ESpalette };
+
+/* console_sem is held (except via vc_init()) */
+static void reset_terminal(struct vc_data *vc, int do_clear)
+{
+	vc->vc_top		= 0;
+	vc->vc_bottom		= vc->vc_rows;
+	vc->vc_state		= ESnormal;
+	vc->vc_ques		= 0;
+	vc->vc_translate	= set_translate(LAT1_MAP, vc);
+	vc->vc_G0_charset	= LAT1_MAP;
+	vc->vc_G1_charset	= GRAF_MAP;
+	vc->vc_charset		= 0;
+	vc->vc_need_wrap	= 0;
+	vc->vc_report_mouse	= 0;
+	vc->vc_utf              = default_utf8;
+	vc->vc_utf_count	= 0;
+
+	vc->vc_disp_ctrl	= 0;
+	vc->vc_toggle_meta	= 0;
+
+	vc->vc_decscnm		= 0;
+	vc->vc_decom		= 0;
+	vc->vc_decawm		= 1;
+	vc->vc_deccm		= global_cursor_default;
+	vc->vc_decim		= 0;
+
+	set_kbd(vc, decarm);
+	clr_kbd(vc, decckm);
+	clr_kbd(vc, kbdapplic);
+	clr_kbd(vc, lnm);
+	kbd_table[vc->vc_num].lockstate = 0;
+	kbd_table[vc->vc_num].slockstate = 0;
+	kbd_table[vc->vc_num].ledmode = LED_SHOW_FLAGS;
+	kbd_table[vc->vc_num].ledflagstate = kbd_table[vc->vc_num].default_ledflagstate;
+	/* do not do set_leds here because this causes an endless tasklet loop
+	   when the keyboard hasn't been initialized yet */
+
+	vc->vc_cursor_type = cur_default;
+	vc->vc_complement_mask = vc->vc_s_complement_mask;
+
+	default_attr(vc);
+	update_attr(vc);
+
+	vc->vc_tab_stop[0]	= 0x01010100;
+	vc->vc_tab_stop[1]	=
+	vc->vc_tab_stop[2]	=
+	vc->vc_tab_stop[3]	=
+	vc->vc_tab_stop[4]	=
+	vc->vc_tab_stop[5]	=
+	vc->vc_tab_stop[6]	=
+	vc->vc_tab_stop[7]	= 0x01010101;
+
+	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
+	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
+
+	gotoxy(vc, 0, 0);
+	save_cur(vc);
+	if (do_clear)
+	    csi_J(vc, 2);
+}
+
+/* console_sem is held */
+static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
+{
+	/*
+	 *  Control characters can be used in the _middle_
+	 *  of an escape sequence.
+	 */
+	switch (c) {
+	case 0:
+		return;
+	case 7:
+		if (vc->vc_bell_duration)
+			kd_mksound(vc->vc_bell_pitch, vc->vc_bell_duration);
+		return;
+	case 8:
+		bs(vc);
+		return;
+	case 9:
+		vc->vc_pos -= (vc->vc_x << 1);
+		while (vc->vc_x < vc->vc_cols - 1) {
+			vc->vc_x++;
+			if (vc->vc_tab_stop[vc->vc_x >> 5] & (1 << (vc->vc_x & 31)))
+				break;
+		}
+		vc->vc_pos += (vc->vc_x << 1);
+		notify_write(vc, '\t');
+		return;
+	case 10: case 11: case 12:
+		lf(vc);
+		if (!is_kbd(vc, lnm))
+			return;
+	case 13:
+		cr(vc);
+		return;
+	case 14:
+		vc->vc_charset = 1;
+		vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
+		vc->vc_disp_ctrl = 1;
+		return;
+	case 15:
+		vc->vc_charset = 0;
+		vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
+		vc->vc_disp_ctrl = 0;
+		return;
+	case 24: case 26:
+		vc->vc_state = ESnormal;
+		return;
+	case 27:
+		vc->vc_state = ESesc;
+		return;
+	case 127:
+		del(vc);
+		return;
+	case 128+27:
+		vc->vc_state = ESsquare;
+		return;
+	}
+	switch(vc->vc_state) {
+	case ESesc:
+		vc->vc_state = ESnormal;
+		switch (c) {
+		case '[':
+			vc->vc_state = ESsquare;
+			return;
+		case ']':
+			vc->vc_state = ESnonstd;
+			return;
+		case '%':
+			vc->vc_state = ESpercent;
+			return;
+		case 'E':
+			cr(vc);
+			lf(vc);
+			return;
+		case 'M':
+			ri(vc);
+			return;
+		case 'D':
+			lf(vc);
+			return;
+		case 'H':
+			vc->vc_tab_stop[vc->vc_x >> 5] |= (1 << (vc->vc_x & 31));
+			return;
+		case 'Z':
+			respond_ID(tty);
+			return;
+		case '7':
+			save_cur(vc);
+			return;
+		case '8':
+			restore_cur(vc);
+			return;
+		case '(':
+			vc->vc_state = ESsetG0;
+			return;
+		case ')':
+			vc->vc_state = ESsetG1;
+			return;
+		case '#':
+			vc->vc_state = EShash;
+			return;
+		case 'c':
+			reset_terminal(vc, 1);
+			return;
+		case '>':  /* Numeric keypad */
+			clr_kbd(vc, kbdapplic);
+			return;
+		case '=':  /* Appl. keypad */
+			set_kbd(vc, kbdapplic);
+			return;
+		}
+		return;
+	case ESnonstd:
+		if (c=='P') {   /* palette escape sequence */
+			for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
+				vc->vc_par[vc->vc_npar] = 0;
+			vc->vc_npar = 0;
+			vc->vc_state = ESpalette;
+			return;
+		} else if (c=='R') {   /* reset palette */
+			reset_palette(vc);
+			vc->vc_state = ESnormal;
+		} else
+			vc->vc_state = ESnormal;
+		return;
+	case ESpalette:
+		if (isxdigit(c)) {
+			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
+			if (vc->vc_npar == 7) {
+				int i = vc->vc_par[0] * 3, j = 1;
+				vc->vc_palette[i] = 16 * vc->vc_par[j++];
+				vc->vc_palette[i++] += vc->vc_par[j++];
+				vc->vc_palette[i] = 16 * vc->vc_par[j++];
+				vc->vc_palette[i++] += vc->vc_par[j++];
+				vc->vc_palette[i] = 16 * vc->vc_par[j++];
+				vc->vc_palette[i] += vc->vc_par[j];
+				set_palette(vc);
+				vc->vc_state = ESnormal;
+			}
+		} else
+			vc->vc_state = ESnormal;
+		return;
+	case ESsquare:
+		for (vc->vc_npar = 0; vc->vc_npar < NPAR; vc->vc_npar++)
+			vc->vc_par[vc->vc_npar] = 0;
+		vc->vc_npar = 0;
+		vc->vc_state = ESgetpars;
+		if (c == '[') { /* Function key */
+			vc->vc_state=ESfunckey;
+			return;
+		}
+		vc->vc_ques = (c == '?');
+		if (vc->vc_ques)
+			return;
+	case ESgetpars:
+		if (c == ';' && vc->vc_npar < NPAR - 1) {
+			vc->vc_npar++;
+			return;
+		} else if (c>='0' && c<='9') {
+			vc->vc_par[vc->vc_npar] *= 10;
+			vc->vc_par[vc->vc_npar] += c - '0';
+			return;
+		} else
+			vc->vc_state = ESgotpars;
+	case ESgotpars:
+		vc->vc_state = ESnormal;
+		switch(c) {
+		case 'h':
+			set_mode(vc, 1);
+			return;
+		case 'l':
+			set_mode(vc, 0);
+			return;
+		case 'c':
+			if (vc->vc_ques) {
+				if (vc->vc_par[0])
+					vc->vc_cursor_type = vc->vc_par[0] | (vc->vc_par[1] << 8) | (vc->vc_par[2] << 16);
+				else
+					vc->vc_cursor_type = cur_default;
+				return;
+			}
+			break;
+		case 'm':
+			if (vc->vc_ques) {
+				clear_selection();
+				if (vc->vc_par[0])
+					vc->vc_complement_mask = vc->vc_par[0] << 8 | vc->vc_par[1];
+				else
+					vc->vc_complement_mask = vc->vc_s_complement_mask;
+				return;
+			}
+			break;
+		case 'n':
+			if (!vc->vc_ques) {
+				if (vc->vc_par[0] == 5)
+					status_report(tty);
+				else if (vc->vc_par[0] == 6)
+					cursor_report(vc, tty);
+			}
+			return;
+		}
+		if (vc->vc_ques) {
+			vc->vc_ques = 0;
+			return;
+		}
+		switch(c) {
+		case 'G': case '`':
+			if (vc->vc_par[0])
+				vc->vc_par[0]--;
+			gotoxy(vc, vc->vc_par[0], vc->vc_y);
+			return;
+		case 'A':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->vc_x, vc->vc_y - vc->vc_par[0]);
+			return;
+		case 'B': case 'e':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->vc_x, vc->vc_y + vc->vc_par[0]);
+			return;
+		case 'C': case 'a':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->vc_x + vc->vc_par[0], vc->vc_y);
+			return;
+		case 'D':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, vc->vc_x - vc->vc_par[0], vc->vc_y);
+			return;
+		case 'E':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, 0, vc->vc_y + vc->vc_par[0]);
+			return;
+		case 'F':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			gotoxy(vc, 0, vc->vc_y - vc->vc_par[0]);
+			return;
+		case 'd':
+			if (vc->vc_par[0])
+				vc->vc_par[0]--;
+			gotoxay(vc, vc->vc_x ,vc->vc_par[0]);
+			return;
+		case 'H': case 'f':
+			if (vc->vc_par[0])
+				vc->vc_par[0]--;
+			if (vc->vc_par[1])
+				vc->vc_par[1]--;
+			gotoxay(vc, vc->vc_par[1], vc->vc_par[0]);
+			return;
+		case 'J':
+			csi_J(vc, vc->vc_par[0]);
+			return;
+		case 'K':
+			csi_K(vc, vc->vc_par[0]);
+			return;
+		case 'L':
+			csi_L(vc, vc->vc_par[0]);
+			return;
+		case 'M':
+			csi_M(vc, vc->vc_par[0]);
+			return;
+		case 'P':
+			csi_P(vc, vc->vc_par[0]);
+			return;
+		case 'c':
+			if (!vc->vc_par[0])
+				respond_ID(tty);
+			return;
+		case 'g':
+			if (!vc->vc_par[0])
+				vc->vc_tab_stop[vc->vc_x >> 5] &= ~(1 << (vc->vc_x & 31));
+			else if (vc->vc_par[0] == 3) {
+				vc->vc_tab_stop[0] =
+					vc->vc_tab_stop[1] =
+					vc->vc_tab_stop[2] =
+					vc->vc_tab_stop[3] =
+					vc->vc_tab_stop[4] =
+					vc->vc_tab_stop[5] =
+					vc->vc_tab_stop[6] =
+					vc->vc_tab_stop[7] = 0;
+			}
+			return;
+		case 'm':
+			csi_m(vc);
+			return;
+		case 'q': /* DECLL - but only 3 leds */
+			/* map 0,1,2,3 to 0,1,2,4 */
+			if (vc->vc_par[0] < 4)
+				setledstate(kbd_table + vc->vc_num,
+					    (vc->vc_par[0] < 3) ? vc->vc_par[0] : 4);
+			return;
+		case 'r':
+			if (!vc->vc_par[0])
+				vc->vc_par[0]++;
+			if (!vc->vc_par[1])
+				vc->vc_par[1] = vc->vc_rows;
+			/* Minimum allowed region is 2 lines */
+			if (vc->vc_par[0] < vc->vc_par[1] &&
+			    vc->vc_par[1] <= vc->vc_rows) {
+				vc->vc_top = vc->vc_par[0] - 1;
+				vc->vc_bottom = vc->vc_par[1];
+				gotoxay(vc, 0, 0);
+			}
+			return;
+		case 's':
+			save_cur(vc);
+			return;
+		case 'u':
+			restore_cur(vc);
+			return;
+		case 'X':
+			csi_X(vc, vc->vc_par[0]);
+			return;
+		case '@':
+			csi_at(vc, vc->vc_par[0]);
+			return;
+		case ']': /* setterm functions */
+			setterm_command(vc);
+			return;
+		}
+		return;
+	case ESpercent:
+		vc->vc_state = ESnormal;
+		switch (c) {
+		case '@':  /* defined in ISO 2022 */
+			vc->vc_utf = 0;
+			return;
+		case 'G':  /* prelim official escape code */
+		case '8':  /* retained for compatibility */
+			vc->vc_utf = 1;
+			return;
+		}
+		return;
+	case ESfunckey:
+		vc->vc_state = ESnormal;
+		return;
+	case EShash:
+		vc->vc_state = ESnormal;
+		if (c == '8') {
+			/* DEC screen alignment test. kludge :-) */
+			vc->vc_video_erase_char =
+				(vc->vc_video_erase_char & 0xff00) | 'E';
+			csi_J(vc, 2);
+			vc->vc_video_erase_char =
+				(vc->vc_video_erase_char & 0xff00) | ' ';
+			do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2);
+		}
+		return;
+	case ESsetG0:
+		if (c == '0')
+			vc->vc_G0_charset = GRAF_MAP;
+		else if (c == 'B')
+			vc->vc_G0_charset = LAT1_MAP;
+		else if (c == 'U')
+			vc->vc_G0_charset = IBMPC_MAP;
+		else if (c == 'K')
+			vc->vc_G0_charset = USER_MAP;
+		if (vc->vc_charset == 0)
+			vc->vc_translate = set_translate(vc->vc_G0_charset, vc);
+		vc->vc_state = ESnormal;
+		return;
+	case ESsetG1:
+		if (c == '0')
+			vc->vc_G1_charset = GRAF_MAP;
+		else if (c == 'B')
+			vc->vc_G1_charset = LAT1_MAP;
+		else if (c == 'U')
+			vc->vc_G1_charset = IBMPC_MAP;
+		else if (c == 'K')
+			vc->vc_G1_charset = USER_MAP;
+		if (vc->vc_charset == 1)
+			vc->vc_translate = set_translate(vc->vc_G1_charset, vc);
+		vc->vc_state = ESnormal;
+		return;
+	default:
+		vc->vc_state = ESnormal;
+	}
+}
+
+/* This is a temporary buffer used to prepare a tty console write
+ * so that we can easily avoid touching user space while holding the
+ * console spinlock.  It is allocated in con_init and is shared by
+ * this code and the vc_screen read/write tty calls.
+ *
+ * We have to allocate this statically in the kernel data section
+ * since console_init (and thus con_init) are called before any
+ * kernel memory allocation is available.
+ */
+char con_buf[CON_BUF_SIZE];
+DEFINE_MUTEX(con_buf_mtx);
+
+/* is_double_width() is based on the wcwidth() implementation by
+ * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
+ * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
+ */
+struct interval {
+	uint32_t first;
+	uint32_t last;
+};
+
+static int bisearch(uint32_t ucs, const struct interval *table, int max)
+{
+	int min = 0;
+	int mid;
+
+	if (ucs < table[0].first || ucs > table[max].last)
+		return 0;
+	while (max >= min) {
+		mid = (min + max) / 2;
+		if (ucs > table[mid].last)
+			min = mid + 1;
+		else if (ucs < table[mid].first)
+			max = mid - 1;
+		else
+			return 1;
+	}
+	return 0;
+}
+
+static int is_double_width(uint32_t ucs)
+{
+	static const struct interval double_width[] = {
+		{ 0x1100, 0x115F }, { 0x2329, 0x232A }, { 0x2E80, 0x303E },
+		{ 0x3040, 0xA4CF }, { 0xAC00, 0xD7A3 }, { 0xF900, 0xFAFF },
+		{ 0xFE10, 0xFE19 }, { 0xFE30, 0xFE6F }, { 0xFF00, 0xFF60 },
+		{ 0xFFE0, 0xFFE6 }, { 0x20000, 0x2FFFD }, { 0x30000, 0x3FFFD }
+	};
+	return bisearch(ucs, double_width, ARRAY_SIZE(double_width) - 1);
+}
+
+/* acquires console_sem */
+static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
+{
+#ifdef VT_BUF_VRAM_ONLY
+#define FLUSH do { } while(0);
+#else
+#define FLUSH if (draw_x >= 0) { \
+	vc->vc_sw->con_putcs(vc, (u16 *)draw_from, (u16 *)draw_to - (u16 *)draw_from, vc->vc_y, draw_x); \
+	draw_x = -1; \
+	}
+#endif
+
+	int c, tc, ok, n = 0, draw_x = -1;
+	unsigned int currcons;
+	unsigned long draw_from = 0, draw_to = 0;
+	struct vc_data *vc;
+	unsigned char vc_attr;
+	struct vt_notifier_param param;
+	uint8_t rescan;
+	uint8_t inverse;
+	uint8_t width;
+	u16 himask, charmask;
+
+	if (in_interrupt())
+		return count;
+
+	might_sleep();
+
+	acquire_console_sem();
+	vc = tty->driver_data;
+	if (vc == NULL) {
+		printk(KERN_ERR "vt: argh, driver_data is NULL !\n");
+		release_console_sem();
+		return 0;
+	}
+
+	currcons = vc->vc_num;
+	if (!vc_cons_allocated(currcons)) {
+	    /* could this happen? */
+		printk_once("con_write: tty %d not allocated\n", currcons+1);
+	    release_console_sem();
+	    return 0;
+	}
+
+	himask = vc->vc_hi_font_mask;
+	charmask = himask ? 0x1ff : 0xff;
+
+	/* undraw cursor first */
+	if (IS_FG(vc))
+		hide_cursor(vc);
+
+	param.vc = vc;
+
+	while (!tty->stopped && count) {
+		int orig = *buf;
+		c = orig;
+		buf++;
+		n++;
+		count--;
+		rescan = 0;
+		inverse = 0;
+		width = 1;
+
+		/* Do no translation at all in control states */
+		if (vc->vc_state != ESnormal) {
+			tc = c;
+		} else if (vc->vc_utf && !vc->vc_disp_ctrl) {
+		    /* Combine UTF-8 into Unicode in vc_utf_char.
+		     * vc_utf_count is the number of continuation bytes still
+		     * expected to arrive.
+		     * vc_npar is the number of continuation bytes arrived so
+		     * far
+		     */
+rescan_last_byte:
+		    if ((c & 0xc0) == 0x80) {
+			/* Continuation byte received */
+			static const uint32_t utf8_length_changes[] = { 0x0000007f, 0x000007ff, 0x0000ffff, 0x001fffff, 0x03ffffff, 0x7fffffff };
+			if (vc->vc_utf_count) {
+			    vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f);
+			    vc->vc_npar++;
+			    if (--vc->vc_utf_count) {
+				/* Still need some bytes */
+				continue;
+			    }
+			    /* Got a whole character */
+			    c = vc->vc_utf_char;
+			    /* Reject overlong sequences */
+			    if (c <= utf8_length_changes[vc->vc_npar - 1] ||
+					c > utf8_length_changes[vc->vc_npar])
+				c = 0xfffd;
+			} else {
+			    /* Unexpected continuation byte */
+			    vc->vc_utf_count = 0;
+			    c = 0xfffd;
+			}
+		    } else {
+			/* Single ASCII byte or first byte of a sequence received */
+			if (vc->vc_utf_count) {
+			    /* Continuation byte expected */
+			    rescan = 1;
+			    vc->vc_utf_count = 0;
+			    c = 0xfffd;
+			} else if (c > 0x7f) {
+			    /* First byte of a multibyte sequence received */
+			    vc->vc_npar = 0;
+			    if ((c & 0xe0) == 0xc0) {
+				vc->vc_utf_count = 1;
+				vc->vc_utf_char = (c & 0x1f);
+			    } else if ((c & 0xf0) == 0xe0) {
+				vc->vc_utf_count = 2;
+				vc->vc_utf_char = (c & 0x0f);
+			    } else if ((c & 0xf8) == 0xf0) {
+				vc->vc_utf_count = 3;
+				vc->vc_utf_char = (c & 0x07);
+			    } else if ((c & 0xfc) == 0xf8) {
+				vc->vc_utf_count = 4;
+				vc->vc_utf_char = (c & 0x03);
+			    } else if ((c & 0xfe) == 0xfc) {
+				vc->vc_utf_count = 5;
+				vc->vc_utf_char = (c & 0x01);
+			    } else {
+				/* 254 and 255 are invalid */
+				c = 0xfffd;
+			    }
+			    if (vc->vc_utf_count) {
+				/* Still need some bytes */
+				continue;
+			    }
+			}
+			/* Nothing to do if an ASCII byte was received */
+		    }
+		    /* End of UTF-8 decoding. */
+		    /* c is the received character, or U+FFFD for invalid sequences. */
+		    /* Replace invalid Unicode code points with U+FFFD too */
+		    if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff)
+			c = 0xfffd;
+		    tc = c;
+		} else {	/* no utf or alternate charset mode */
+		    tc = vc_translate(vc, c);
+		}
+
+		param.c = tc;
+		if (atomic_notifier_call_chain(&vt_notifier_list, VT_PREWRITE,
+					&param) == NOTIFY_STOP)
+			continue;
+
+                /* If the original code was a control character we
+                 * only allow a glyph to be displayed if the code is
+                 * not normally used (such as for cursor movement) or
+                 * if the disp_ctrl mode has been explicitly enabled.
+                 * Certain characters (as given by the CTRL_ALWAYS
+                 * bitmap) are always displayed as control characters,
+                 * as the console would be pretty useless without
+                 * them; to display an arbitrary font position use the
+                 * direct-to-font zone in UTF-8 mode.
+                 */
+                ok = tc && (c >= 32 ||
+			    !(vc->vc_disp_ctrl ? (CTRL_ALWAYS >> c) & 1 :
+				  vc->vc_utf || ((CTRL_ACTION >> c) & 1)))
+			&& (c != 127 || vc->vc_disp_ctrl)
+			&& (c != 128+27);
+
+		if (vc->vc_state == ESnormal && ok) {
+			if (vc->vc_utf && !vc->vc_disp_ctrl) {
+				if (is_double_width(c))
+					width = 2;
+			}
+			/* Now try to find out how to display it */
+			tc = conv_uni_to_pc(vc, tc);
+			if (tc & ~charmask) {
+				if (tc == -1 || tc == -2) {
+				    continue; /* nothing to display */
+				}
+				/* Glyph not found */
+				if ((!(vc->vc_utf && !vc->vc_disp_ctrl) || c < 128) && !(c & ~charmask)) {
+				    /* In legacy mode use the glyph we get by a 1:1 mapping.
+				       This would make absolutely no sense with Unicode in mind,
+				       but do this for ASCII characters since a font may lack
+				       Unicode mapping info and we don't want to end up with
+				       having question marks only. */
+				    tc = c;
+				} else {
+				    /* Display U+FFFD. If it's not found, display an inverse question mark. */
+				    tc = conv_uni_to_pc(vc, 0xfffd);
+				    if (tc < 0) {
+					inverse = 1;
+					tc = conv_uni_to_pc(vc, '?');
+					if (tc < 0) tc = '?';
+				    }
+				}
+			}
+
+			if (!inverse) {
+				vc_attr = vc->vc_attr;
+			} else {
+				/* invert vc_attr */
+				if (!vc->vc_can_do_color) {
+					vc_attr = (vc->vc_attr) ^ 0x08;
+				} else if (vc->vc_hi_font_mask == 0x100) {
+					vc_attr = ((vc->vc_attr) & 0x11) | (((vc->vc_attr) & 0xe0) >> 4) | (((vc->vc_attr) & 0x0e) << 4);
+				} else {
+					vc_attr = ((vc->vc_attr) & 0x88) | (((vc->vc_attr) & 0x70) >> 4) | (((vc->vc_attr) & 0x07) << 4);
+				}
+				FLUSH
+			}
+
+			while (1) {
+				if (vc->vc_need_wrap || vc->vc_decim)
+					FLUSH
+				if (vc->vc_need_wrap) {
+					cr(vc);
+					lf(vc);
+				}
+				if (vc->vc_decim)
+					insert_char(vc, 1);
+				scr_writew(himask ?
+					     ((vc_attr << 8) & ~himask) + ((tc & 0x100) ? himask : 0) + (tc & 0xff) :
+					     (vc_attr << 8) + tc,
+					   (u16 *) vc->vc_pos);
+				if (DO_UPDATE(vc) && draw_x < 0) {
+					draw_x = vc->vc_x;
+					draw_from = vc->vc_pos;
+				}
+				if (vc->vc_x == vc->vc_cols - 1) {
+					vc->vc_need_wrap = vc->vc_decawm;
+					draw_to = vc->vc_pos + 2;
+				} else {
+					vc->vc_x++;
+					draw_to = (vc->vc_pos += 2);
+				}
+
+				if (!--width) break;
+
+				tc = conv_uni_to_pc(vc, ' '); /* A space is printed in the second column */
+				if (tc < 0) tc = ' ';
+			}
+			notify_write(vc, c);
+
+			if (inverse) {
+				FLUSH
+			}
+
+			if (rescan) {
+				rescan = 0;
+				inverse = 0;
+				width = 1;
+				c = orig;
+				goto rescan_last_byte;
+			}
+			continue;
+		}
+		FLUSH
+		do_con_trol(tty, vc, orig);
+	}
+	FLUSH
+	console_conditional_schedule();
+	release_console_sem();
+	notify_update(vc);
+	return n;
+#undef FLUSH
+}
+
+/*
+ * This is the console switching callback.
+ *
+ * Doing console switching in a process context allows
+ * us to do the switches asynchronously (needed when we want
+ * to switch due to a keyboard interrupt).  Synchronization
+ * with other console code and prevention of re-entrancy is
+ * ensured with console_sem.
+ */
+static void console_callback(struct work_struct *ignored)
+{
+	acquire_console_sem();
+
+	if (want_console >= 0) {
+		if (want_console != fg_console &&
+		    vc_cons_allocated(want_console)) {
+			hide_cursor(vc_cons[fg_console].d);
+			change_console(vc_cons[want_console].d);
+			/* we only changed when the console had already
+			   been allocated - a new console is not created
+			   in an interrupt routine */
+		}
+		want_console = -1;
+	}
+	if (do_poke_blanked_console) { /* do not unblank for a LED change */
+		do_poke_blanked_console = 0;
+		poke_blanked_console();
+	}
+	if (scrollback_delta) {
+		struct vc_data *vc = vc_cons[fg_console].d;
+		clear_selection();
+		if (vc->vc_mode == KD_TEXT)
+			vc->vc_sw->con_scrolldelta(vc, scrollback_delta);
+		scrollback_delta = 0;
+	}
+	if (blank_timer_expired) {
+		do_blank_screen(0);
+		blank_timer_expired = 0;
+	}
+	notify_update(vc_cons[fg_console].d);
+
+	release_console_sem();
+}
+
+int set_console(int nr)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+
+	if (!vc_cons_allocated(nr) || vt_dont_switch ||
+		(vc->vt_mode.mode == VT_AUTO && vc->vc_mode == KD_GRAPHICS)) {
+
+		/*
+		 * Console switch will fail in console_callback() or
+		 * change_console() so there is no point scheduling
+		 * the callback
+		 *
+		 * Existing set_console() users don't check the return
+		 * value so this shouldn't break anything
+		 */
+		return -EINVAL;
+	}
+
+	want_console = nr;
+	schedule_console_callback();
+
+	return 0;
+}
+
+struct tty_driver *console_driver;
+
+#ifdef CONFIG_VT_CONSOLE
+
+/**
+ * vt_kmsg_redirect() - Sets/gets the kernel message console
+ * @new:	The new virtual terminal number or -1 if the console should stay
+ * 		unchanged
+ *
+ * By default, the kernel messages are always printed on the current virtual
+ * console. However, the user may modify that default with the
+ * TIOCL_SETKMSGREDIRECT ioctl call.
+ *
+ * This function sets the kernel message console to be @new. It returns the old
+ * virtual console number. The virtual terminal number 0 (both as parameter and
+ * return value) means no redirection (i.e. always printed on the currently
+ * active console).
+ *
+ * The parameter -1 means that only the current console is returned, but the
+ * value is not modified. You may use the macro vt_get_kmsg_redirect() in that
+ * case to make the code more understandable.
+ *
+ * When the kernel is compiled without CONFIG_VT_CONSOLE, this function ignores
+ * the parameter and always returns 0.
+ */
+int vt_kmsg_redirect(int new)
+{
+	static int kmsg_con;
+
+	if (new != -1)
+		return xchg(&kmsg_con, new);
+	else
+		return kmsg_con;
+}
+
+/*
+ *	Console on virtual terminal
+ *
+ * The console must be locked when we get here.
+ */
+
+static void vt_console_print(struct console *co, const char *b, unsigned count)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+	unsigned char c;
+	static DEFINE_SPINLOCK(printing_lock);
+	const ushort *start;
+	ushort cnt = 0;
+	ushort myx;
+	int kmsg_console;
+
+	/* console busy or not yet initialized */
+	if (!printable)
+		return;
+	if (!spin_trylock(&printing_lock))
+		return;
+
+	kmsg_console = vt_get_kmsg_redirect();
+	if (kmsg_console && vc_cons_allocated(kmsg_console - 1))
+		vc = vc_cons[kmsg_console - 1].d;
+
+	/* read `x' only after setting currcons properly (otherwise
+	   the `x' macro will read the x of the foreground console). */
+	myx = vc->vc_x;
+
+	if (!vc_cons_allocated(fg_console)) {
+		/* impossible */
+		/* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */
+		goto quit;
+	}
+
+	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
+		goto quit;
+
+	/* undraw cursor first */
+	if (IS_FG(vc))
+		hide_cursor(vc);
+
+	start = (ushort *)vc->vc_pos;
+
+	/* Contrived structure to try to emulate original need_wrap behaviour
+	 * Problems caused when we have need_wrap set on '\n' character */
+	while (count--) {
+		c = *b++;
+		if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) {
+			if (cnt > 0) {
+				if (CON_IS_VISIBLE(vc))
+					vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
+				vc->vc_x += cnt;
+				if (vc->vc_need_wrap)
+					vc->vc_x--;
+				cnt = 0;
+			}
+			if (c == 8) {		/* backspace */
+				bs(vc);
+				start = (ushort *)vc->vc_pos;
+				myx = vc->vc_x;
+				continue;
+			}
+			if (c != 13)
+				lf(vc);
+			cr(vc);
+			start = (ushort *)vc->vc_pos;
+			myx = vc->vc_x;
+			if (c == 10 || c == 13)
+				continue;
+		}
+		scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos);
+		notify_write(vc, c);
+		cnt++;
+		if (myx == vc->vc_cols - 1) {
+			vc->vc_need_wrap = 1;
+			continue;
+		}
+		vc->vc_pos += 2;
+		myx++;
+	}
+	if (cnt > 0) {
+		if (CON_IS_VISIBLE(vc))
+			vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x);
+		vc->vc_x += cnt;
+		if (vc->vc_x == vc->vc_cols) {
+			vc->vc_x--;
+			vc->vc_need_wrap = 1;
+		}
+	}
+	set_cursor(vc);
+	notify_update(vc);
+
+quit:
+	spin_unlock(&printing_lock);
+}
+
+static struct tty_driver *vt_console_device(struct console *c, int *index)
+{
+	*index = c->index ? c->index-1 : fg_console;
+	return console_driver;
+}
+
+static struct console vt_console_driver = {
+	.name		= "tty",
+	.write		= vt_console_print,
+	.device		= vt_console_device,
+	.unblank	= unblank_screen,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+};
+#endif
+
+/*
+ *	Handling of Linux-specific VC ioctls
+ */
+
+/*
+ * Generally a bit racy with respect to console_sem().
+ *
+ * There are some functions which don't need it.
+ *
+ * There are some functions which can sleep for arbitrary periods
+ * (paste_selection) but we don't need the lock there anyway.
+ *
+ * set_selection has locking, and definitely needs it
+ */
+
+int tioclinux(struct tty_struct *tty, unsigned long arg)
+{
+	char type, data;
+	char __user *p = (char __user *)arg;
+	int lines;
+	int ret;
+
+	if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (get_user(type, p))
+		return -EFAULT;
+	ret = 0;
+
+	switch (type)
+	{
+		case TIOCL_SETSEL:
+			acquire_console_sem();
+			ret = set_selection((struct tiocl_selection __user *)(p+1), tty);
+			release_console_sem();
+			break;
+		case TIOCL_PASTESEL:
+			ret = paste_selection(tty);
+			break;
+		case TIOCL_UNBLANKSCREEN:
+			acquire_console_sem();
+			unblank_screen();
+			release_console_sem();
+			break;
+		case TIOCL_SELLOADLUT:
+			ret = sel_loadlut(p);
+			break;
+		case TIOCL_GETSHIFTSTATE:
+
+	/*
+	 * Make it possible to react to Shift+Mousebutton.
+	 * Note that 'shift_state' is an undocumented
+	 * kernel-internal variable; programs not closely
+	 * related to the kernel should not use this.
+	 */
+	 		data = shift_state;
+			ret = __put_user(data, p);
+			break;
+		case TIOCL_GETMOUSEREPORTING:
+			data = mouse_reporting();
+			ret = __put_user(data, p);
+			break;
+		case TIOCL_SETVESABLANK:
+			ret = set_vesa_blanking(p);
+			break;
+		case TIOCL_GETKMSGREDIRECT:
+			data = vt_get_kmsg_redirect();
+			ret = __put_user(data, p);
+			break;
+		case TIOCL_SETKMSGREDIRECT:
+			if (!capable(CAP_SYS_ADMIN)) {
+				ret = -EPERM;
+			} else {
+				if (get_user(data, p+1))
+					ret = -EFAULT;
+				else
+					vt_kmsg_redirect(data);
+			}
+			break;
+		case TIOCL_GETFGCONSOLE:
+			ret = fg_console;
+			break;
+		case TIOCL_SCROLLCONSOLE:
+			if (get_user(lines, (s32 __user *)(p+4))) {
+				ret = -EFAULT;
+			} else {
+				scrollfront(vc_cons[fg_console].d, lines);
+				ret = 0;
+			}
+			break;
+		case TIOCL_BLANKSCREEN:	/* until explicitly unblanked, not only poked */
+			acquire_console_sem();
+			ignore_poke = 1;
+			do_blank_screen(0);
+			release_console_sem();
+			break;
+		case TIOCL_BLANKEDSCREEN:
+			ret = console_blanked;
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+	}
+	return ret;
+}
+
+/*
+ * /dev/ttyN handling
+ */
+
+static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
+{
+	int	retval;
+
+	retval = do_con_write(tty, buf, count);
+	con_flush_chars(tty);
+
+	return retval;
+}
+
+static int con_put_char(struct tty_struct *tty, unsigned char ch)
+{
+	if (in_interrupt())
+		return 0;	/* n_r3964 calls put_char() from interrupt context */
+	return do_con_write(tty, &ch, 1);
+}
+
+static int con_write_room(struct tty_struct *tty)
+{
+	if (tty->stopped)
+		return 0;
+	return 32768;		/* No limit, really; we're not buffering */
+}
+
+static int con_chars_in_buffer(struct tty_struct *tty)
+{
+	return 0;		/* we're not buffering */
+}
+
+/*
+ * con_throttle and con_unthrottle are only used for
+ * paste_selection(), which has to stuff in a large number of
+ * characters...
+ */
+static void con_throttle(struct tty_struct *tty)
+{
+}
+
+static void con_unthrottle(struct tty_struct *tty)
+{
+	struct vc_data *vc = tty->driver_data;
+
+	wake_up_interruptible(&vc->paste_wait);
+}
+
+/*
+ * Turn the Scroll-Lock LED on when the tty is stopped
+ */
+static void con_stop(struct tty_struct *tty)
+{
+	int console_num;
+	if (!tty)
+		return;
+	console_num = tty->index;
+	if (!vc_cons_allocated(console_num))
+		return;
+	set_vc_kbd_led(kbd_table + console_num, VC_SCROLLOCK);
+	set_leds();
+}
+
+/*
+ * Turn the Scroll-Lock LED off when the console is started
+ */
+static void con_start(struct tty_struct *tty)
+{
+	int console_num;
+	if (!tty)
+		return;
+	console_num = tty->index;
+	if (!vc_cons_allocated(console_num))
+		return;
+	clr_vc_kbd_led(kbd_table + console_num, VC_SCROLLOCK);
+	set_leds();
+}
+
+static void con_flush_chars(struct tty_struct *tty)
+{
+	struct vc_data *vc;
+
+	if (in_interrupt())	/* from flush_to_ldisc */
+		return;
+
+	/* if we race with con_close(), vt may be null */
+	acquire_console_sem();
+	vc = tty->driver_data;
+	if (vc)
+		set_cursor(vc);
+	release_console_sem();
+}
+
+/*
+ * Allocate the console screen memory.
+ */
+static int con_open(struct tty_struct *tty, struct file *filp)
+{
+	unsigned int currcons = tty->index;
+	int ret = 0;
+
+	acquire_console_sem();
+	if (tty->driver_data == NULL) {
+		ret = vc_allocate(currcons);
+		if (ret == 0) {
+			struct vc_data *vc = vc_cons[currcons].d;
+
+			/* Still being freed */
+			if (vc->port.tty) {
+				release_console_sem();
+				return -ERESTARTSYS;
+			}
+			tty->driver_data = vc;
+			vc->port.tty = tty;
+
+			if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
+				tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;
+				tty->winsize.ws_col = vc_cons[currcons].d->vc_cols;
+			}
+			if (vc->vc_utf)
+				tty->termios->c_iflag |= IUTF8;
+			else
+				tty->termios->c_iflag &= ~IUTF8;
+			release_console_sem();
+			return ret;
+		}
+	}
+	release_console_sem();
+	return ret;
+}
+
+static void con_close(struct tty_struct *tty, struct file *filp)
+{
+	/* Nothing to do - we defer to shutdown */
+}
+
+static void con_shutdown(struct tty_struct *tty)
+{
+	struct vc_data *vc = tty->driver_data;
+	BUG_ON(vc == NULL);
+	acquire_console_sem();
+	vc->port.tty = NULL;
+	release_console_sem();
+	tty_shutdown(tty);
+}
+
+static int default_italic_color    = 2; // green (ASCII)
+static int default_underline_color = 3; // cyan (ASCII)
+module_param_named(italic, default_italic_color, int, S_IRUGO | S_IWUSR);
+module_param_named(underline, default_underline_color, int, S_IRUGO | S_IWUSR);
+
+static void vc_init(struct vc_data *vc, unsigned int rows,
+		    unsigned int cols, int do_clear)
+{
+	int j, k ;
+
+	vc->vc_cols = cols;
+	vc->vc_rows = rows;
+	vc->vc_size_row = cols << 1;
+	vc->vc_screenbuf_size = vc->vc_rows * vc->vc_size_row;
+
+	set_origin(vc);
+	vc->vc_pos = vc->vc_origin;
+	reset_vc(vc);
+	for (j=k=0; j<16; j++) {
+		vc->vc_palette[k++] = default_red[j] ;
+		vc->vc_palette[k++] = default_grn[j] ;
+		vc->vc_palette[k++] = default_blu[j] ;
+	}
+	vc->vc_def_color       = 0x07;   /* white */
+	vc->vc_ulcolor         = default_underline_color;
+	vc->vc_itcolor         = default_italic_color;
+	vc->vc_halfcolor       = 0x08;   /* grey */
+	init_waitqueue_head(&vc->paste_wait);
+	reset_terminal(vc, do_clear);
+}
+
+/*
+ * This routine initializes console interrupts, and does nothing
+ * else. If you want the screen to clear, call tty_write with
+ * the appropriate escape-sequence.
+ */
+
+static int __init con_init(void)
+{
+	const char *display_desc = NULL;
+	struct vc_data *vc;
+	unsigned int currcons = 0, i;
+
+	acquire_console_sem();
+
+	if (conswitchp)
+		display_desc = conswitchp->con_startup();
+	if (!display_desc) {
+		fg_console = 0;
+		release_console_sem();
+		return 0;
+	}
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == NULL) {
+			con_driver->con = conswitchp;
+			con_driver->desc = display_desc;
+			con_driver->flag = CON_DRIVER_FLAG_INIT;
+			con_driver->first = 0;
+			con_driver->last = MAX_NR_CONSOLES - 1;
+			break;
+		}
+	}
+
+	for (i = 0; i < MAX_NR_CONSOLES; i++)
+		con_driver_map[i] = conswitchp;
+
+	if (blankinterval) {
+		blank_state = blank_normal_wait;
+		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
+	}
+
+	for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
+		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
+		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
+		tty_port_init(&vc->port);
+		visual_init(vc, currcons, 1);
+		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
+		vc_init(vc, vc->vc_rows, vc->vc_cols,
+			currcons || !vc->vc_sw->con_save_screen);
+	}
+	currcons = fg_console = 0;
+	master_display_fg = vc = vc_cons[currcons].d;
+	set_origin(vc);
+	save_screen(vc);
+	gotoxy(vc, vc->vc_x, vc->vc_y);
+	csi_J(vc, 0);
+	update_screen(vc);
+	printk("Console: %s %s %dx%d",
+		vc->vc_can_do_color ? "colour" : "mono",
+		display_desc, vc->vc_cols, vc->vc_rows);
+	printable = 1;
+	printk("\n");
+
+	release_console_sem();
+
+#ifdef CONFIG_VT_CONSOLE
+	register_console(&vt_console_driver);
+#endif
+	return 0;
+}
+console_initcall(con_init);
+
+static const struct tty_operations con_ops = {
+	.open = con_open,
+	.close = con_close,
+	.write = con_write,
+	.write_room = con_write_room,
+	.put_char = con_put_char,
+	.flush_chars = con_flush_chars,
+	.chars_in_buffer = con_chars_in_buffer,
+	.ioctl = vt_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = vt_compat_ioctl,
+#endif
+	.stop = con_stop,
+	.start = con_start,
+	.throttle = con_throttle,
+	.unthrottle = con_unthrottle,
+	.resize = vt_resize,
+	.shutdown = con_shutdown
+};
+
+static struct cdev vc0_cdev;
+
+int __init vty_init(const struct file_operations *console_fops)
+{
+	cdev_init(&vc0_cdev, console_fops);
+	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
+	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
+		panic("Couldn't register /dev/tty0 driver\n");
+	device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+
+	vcs_init();
+
+	console_driver = alloc_tty_driver(MAX_NR_CONSOLES);
+	if (!console_driver)
+		panic("Couldn't allocate console driver\n");
+	console_driver->owner = THIS_MODULE;
+	console_driver->name = "tty";
+	console_driver->name_base = 1;
+	console_driver->major = TTY_MAJOR;
+	console_driver->minor_start = 1;
+	console_driver->type = TTY_DRIVER_TYPE_CONSOLE;
+	console_driver->init_termios = tty_std_termios;
+	if (default_utf8)
+		console_driver->init_termios.c_iflag |= IUTF8;
+	console_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
+	tty_set_operations(console_driver, &con_ops);
+	if (tty_register_driver(console_driver))
+		panic("Couldn't register console driver\n");
+	kbd_init();
+	console_map_init();
+#ifdef CONFIG_MDA_CONSOLE
+	mda_console_init();
+#endif
+	return 0;
+}
+
+#ifndef VT_SINGLE_DRIVER
+
+static struct class *vtconsole_class;
+
+static int bind_con_driver(const struct consw *csw, int first, int last,
+			   int deflt)
+{
+	struct module *owner = csw->owner;
+	const char *desc = NULL;
+	struct con_driver *con_driver;
+	int i, j = -1, k = -1, retval = -ENODEV;
+
+	if (!try_module_get(owner))
+		return -ENODEV;
+
+	acquire_console_sem();
+
+	/* check if driver is registered */
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == csw) {
+			desc = con_driver->desc;
+			retval = 0;
+			break;
+		}
+	}
+
+	if (retval)
+		goto err;
+
+	if (!(con_driver->flag & CON_DRIVER_FLAG_INIT)) {
+		csw->con_startup();
+		con_driver->flag |= CON_DRIVER_FLAG_INIT;
+	}
+
+	if (deflt) {
+		if (conswitchp)
+			module_put(conswitchp->owner);
+
+		__module_get(owner);
+		conswitchp = csw;
+	}
+
+	first = max(first, con_driver->first);
+	last = min(last, con_driver->last);
+
+	for (i = first; i <= last; i++) {
+		int old_was_color;
+		struct vc_data *vc = vc_cons[i].d;
+
+		if (con_driver_map[i])
+			module_put(con_driver_map[i]->owner);
+		__module_get(owner);
+		con_driver_map[i] = csw;
+
+		if (!vc || !vc->vc_sw)
+			continue;
+
+		j = i;
+
+		if (CON_IS_VISIBLE(vc)) {
+			k = i;
+			save_screen(vc);
+		}
+
+		old_was_color = vc->vc_can_do_color;
+		vc->vc_sw->con_deinit(vc);
+		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
+		visual_init(vc, i, 0);
+		set_origin(vc);
+		update_attr(vc);
+
+		/* If the console changed between mono <-> color, then
+		 * the attributes in the screenbuf will be wrong.  The
+		 * following resets all attributes to something sane.
+		 */
+		if (old_was_color != vc->vc_can_do_color)
+			clear_buffer_attributes(vc);
+	}
+
+	printk("Console: switching ");
+	if (!deflt)
+		printk("consoles %d-%d ", first+1, last+1);
+	if (j >= 0) {
+		struct vc_data *vc = vc_cons[j].d;
+
+		printk("to %s %s %dx%d\n",
+		       vc->vc_can_do_color ? "colour" : "mono",
+		       desc, vc->vc_cols, vc->vc_rows);
+
+		if (k >= 0) {
+			vc = vc_cons[k].d;
+			update_screen(vc);
+		}
+	} else
+		printk("to %s\n", desc);
+
+	retval = 0;
+err:
+	release_console_sem();
+	module_put(owner);
+	return retval;
+};
+
+#ifdef CONFIG_VT_HW_CONSOLE_BINDING
+static int con_is_graphics(const struct consw *csw, int first, int last)
+{
+	int i, retval = 0;
+
+	for (i = first; i <= last; i++) {
+		struct vc_data *vc = vc_cons[i].d;
+
+		if (vc && vc->vc_mode == KD_GRAPHICS) {
+			retval = 1;
+			break;
+		}
+	}
+
+	return retval;
+}
+
+/**
+ * unbind_con_driver - unbind a console driver
+ * @csw: pointer to console driver to unregister
+ * @first: first in range of consoles that @csw should be unbound from
+ * @last: last in range of consoles that @csw should be unbound from
+ * @deflt: should next bound console driver be default after @csw is unbound?
+ *
+ * To unbind a driver from all possible consoles, pass 0 as @first and
+ * %MAX_NR_CONSOLES as @last.
+ *
+ * @deflt controls whether the console that ends up replacing @csw should be
+ * the default console.
+ *
+ * RETURNS:
+ * -ENODEV if @csw isn't a registered console driver or can't be unregistered
+ * or 0 on success.
+ */
+int unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
+{
+	struct module *owner = csw->owner;
+	const struct consw *defcsw = NULL;
+	struct con_driver *con_driver = NULL, *con_back = NULL;
+	int i, retval = -ENODEV;
+
+	if (!try_module_get(owner))
+		return -ENODEV;
+
+	acquire_console_sem();
+
+	/* check if driver is registered and if it is unbindable */
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == csw &&
+		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
+			retval = 0;
+			break;
+		}
+	}
+
+	if (retval) {
+		release_console_sem();
+		goto err;
+	}
+
+	retval = -ENODEV;
+
+	/* check if backup driver exists */
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		con_back = &registered_con_driver[i];
+
+		if (con_back->con &&
+		    !(con_back->flag & CON_DRIVER_FLAG_MODULE)) {
+			defcsw = con_back->con;
+			retval = 0;
+			break;
+		}
+	}
+
+	if (retval) {
+		release_console_sem();
+		goto err;
+	}
+
+	if (!con_is_bound(csw)) {
+		release_console_sem();
+		goto err;
+	}
+
+	first = max(first, con_driver->first);
+	last = min(last, con_driver->last);
+
+	for (i = first; i <= last; i++) {
+		if (con_driver_map[i] == csw) {
+			module_put(csw->owner);
+			con_driver_map[i] = NULL;
+		}
+	}
+
+	if (!con_is_bound(defcsw)) {
+		const struct consw *defconsw = conswitchp;
+
+		defcsw->con_startup();
+		con_back->flag |= CON_DRIVER_FLAG_INIT;
+		/*
+		 * vgacon may change the default driver to point
+		 * to dummycon, we restore it here...
+		 */
+		conswitchp = defconsw;
+	}
+
+	if (!con_is_bound(csw))
+		con_driver->flag &= ~CON_DRIVER_FLAG_INIT;
+
+	release_console_sem();
+	/* ignore return value, binding should not fail */
+	bind_con_driver(defcsw, first, last, deflt);
+err:
+	module_put(owner);
+	return retval;
+
+}
+EXPORT_SYMBOL(unbind_con_driver);
+
+static int vt_bind(struct con_driver *con)
+{
+	const struct consw *defcsw = NULL, *csw = NULL;
+	int i, more = 1, first = -1, last = -1, deflt = 0;
+
+ 	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
+	    con_is_graphics(con->con, con->first, con->last))
+		goto err;
+
+	csw = con->con;
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con = &registered_con_driver[i];
+
+		if (con->con && !(con->flag & CON_DRIVER_FLAG_MODULE)) {
+			defcsw = con->con;
+			break;
+		}
+	}
+
+	if (!defcsw)
+		goto err;
+
+	while (more) {
+		more = 0;
+
+		for (i = con->first; i <= con->last; i++) {
+			if (con_driver_map[i] == defcsw) {
+				if (first == -1)
+					first = i;
+				last = i;
+				more = 1;
+			} else if (first != -1)
+				break;
+		}
+
+		if (first == 0 && last == MAX_NR_CONSOLES -1)
+			deflt = 1;
+
+		if (first != -1)
+			bind_con_driver(csw, first, last, deflt);
+
+		first = -1;
+		last = -1;
+		deflt = 0;
+	}
+
+err:
+	return 0;
+}
+
+static int vt_unbind(struct con_driver *con)
+{
+	const struct consw *csw = NULL;
+	int i, more = 1, first = -1, last = -1, deflt = 0;
+
+ 	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
+	    con_is_graphics(con->con, con->first, con->last))
+		goto err;
+
+	csw = con->con;
+
+	while (more) {
+		more = 0;
+
+		for (i = con->first; i <= con->last; i++) {
+			if (con_driver_map[i] == csw) {
+				if (first == -1)
+					first = i;
+				last = i;
+				more = 1;
+			} else if (first != -1)
+				break;
+		}
+
+		if (first == 0 && last == MAX_NR_CONSOLES -1)
+			deflt = 1;
+
+		if (first != -1)
+			unbind_con_driver(csw, first, last, deflt);
+
+		first = -1;
+		last = -1;
+		deflt = 0;
+	}
+
+err:
+	return 0;
+}
+#else
+static inline int vt_bind(struct con_driver *con)
+{
+	return 0;
+}
+static inline int vt_unbind(struct con_driver *con)
+{
+	return 0;
+}
+#endif /* CONFIG_VT_HW_CONSOLE_BINDING */
+
+static ssize_t store_bind(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct con_driver *con = dev_get_drvdata(dev);
+	int bind = simple_strtoul(buf, NULL, 0);
+
+	if (bind)
+		vt_bind(con);
+	else
+		vt_unbind(con);
+
+	return count;
+}
+
+static ssize_t show_bind(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct con_driver *con = dev_get_drvdata(dev);
+	int bind = con_is_bound(con->con);
+
+	return snprintf(buf, PAGE_SIZE, "%i\n", bind);
+}
+
+static ssize_t show_name(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct con_driver *con = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%s %s\n",
+			(con->flag & CON_DRIVER_FLAG_MODULE) ? "(M)" : "(S)",
+			 con->desc);
+
+}
+
+static struct device_attribute device_attrs[] = {
+	__ATTR(bind, S_IRUGO|S_IWUSR, show_bind, store_bind),
+	__ATTR(name, S_IRUGO, show_name, NULL),
+};
+
+static int vtconsole_init_device(struct con_driver *con)
+{
+	int i;
+	int error = 0;
+
+	con->flag |= CON_DRIVER_FLAG_ATTR;
+	dev_set_drvdata(con->dev, con);
+	for (i = 0; i < ARRAY_SIZE(device_attrs); i++) {
+		error = device_create_file(con->dev, &device_attrs[i]);
+		if (error)
+			break;
+	}
+
+	if (error) {
+		while (--i >= 0)
+			device_remove_file(con->dev, &device_attrs[i]);
+		con->flag &= ~CON_DRIVER_FLAG_ATTR;
+	}
+
+	return error;
+}
+
+static void vtconsole_deinit_device(struct con_driver *con)
+{
+	int i;
+
+	if (con->flag & CON_DRIVER_FLAG_ATTR) {
+		for (i = 0; i < ARRAY_SIZE(device_attrs); i++)
+			device_remove_file(con->dev, &device_attrs[i]);
+		con->flag &= ~CON_DRIVER_FLAG_ATTR;
+	}
+}
+
+/**
+ * con_is_bound - checks if driver is bound to the console
+ * @csw: console driver
+ *
+ * RETURNS: zero if unbound, nonzero if bound
+ *
+ * Drivers can call this and if zero, they should release
+ * all resources allocated on con_startup()
+ */
+int con_is_bound(const struct consw *csw)
+{
+	int i, bound = 0;
+
+	for (i = 0; i < MAX_NR_CONSOLES; i++) {
+		if (con_driver_map[i] == csw) {
+			bound = 1;
+			break;
+		}
+	}
+
+	return bound;
+}
+EXPORT_SYMBOL(con_is_bound);
+
+/**
+ * con_debug_enter - prepare the console for the kernel debugger
+ * @sw: console driver
+ *
+ * Called when the console is taken over by the kernel debugger, this
+ * function needs to save the current console state, then put the console
+ * into a state suitable for the kernel debugger.
+ *
+ * RETURNS:
+ * Zero on success, nonzero if a failure occurred when trying to prepare
+ * the console for the debugger.
+ */
+int con_debug_enter(struct vc_data *vc)
+{
+	int ret = 0;
+
+	saved_fg_console = fg_console;
+	saved_last_console = last_console;
+	saved_want_console = want_console;
+	saved_vc_mode = vc->vc_mode;
+	saved_console_blanked = console_blanked;
+	vc->vc_mode = KD_TEXT;
+	console_blanked = 0;
+	if (vc->vc_sw->con_debug_enter)
+		ret = vc->vc_sw->con_debug_enter(vc);
+#ifdef CONFIG_KGDB_KDB
+	/* Set the initial LINES variable if it is not already set */
+	if (vc->vc_rows < 999) {
+		int linecount;
+		char lns[4];
+		const char *setargs[3] = {
+			"set",
+			"LINES",
+			lns,
+		};
+		if (kdbgetintenv(setargs[0], &linecount)) {
+			snprintf(lns, 4, "%i", vc->vc_rows);
+			kdb_set(2, setargs);
+		}
+	}
+#endif /* CONFIG_KGDB_KDB */
+	return ret;
+}
+EXPORT_SYMBOL_GPL(con_debug_enter);
+
+/**
+ * con_debug_leave - restore console state
+ * @sw: console driver
+ *
+ * Restore the console state to what it was before the kernel debugger
+ * was invoked.
+ *
+ * RETURNS:
+ * Zero on success, nonzero if a failure occurred when trying to restore
+ * the console.
+ */
+int con_debug_leave(void)
+{
+	struct vc_data *vc;
+	int ret = 0;
+
+	fg_console = saved_fg_console;
+	last_console = saved_last_console;
+	want_console = saved_want_console;
+	console_blanked = saved_console_blanked;
+	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
+
+	vc = vc_cons[fg_console].d;
+	if (vc->vc_sw->con_debug_leave)
+		ret = vc->vc_sw->con_debug_leave(vc);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(con_debug_leave);
+
+/**
+ * register_con_driver - register console driver to console layer
+ * @csw: console driver
+ * @first: the first console to take over, minimum value is 0
+ * @last: the last console to take over, maximum value is MAX_NR_CONSOLES -1
+ *
+ * DESCRIPTION: This function registers a console driver which can later
+ * bind to a range of consoles specified by @first and @last. It will
+ * also initialize the console driver by calling con_startup().
+ */
+int register_con_driver(const struct consw *csw, int first, int last)
+{
+	struct module *owner = csw->owner;
+	struct con_driver *con_driver;
+	const char *desc;
+	int i, retval = 0;
+
+	if (!try_module_get(owner))
+		return -ENODEV;
+
+	acquire_console_sem();
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		con_driver = &registered_con_driver[i];
+
+		/* already registered */
+		if (con_driver->con == csw)
+			retval = -EINVAL;
+	}
+
+	if (retval)
+		goto err;
+
+	desc = csw->con_startup();
+
+	if (!desc)
+		goto err;
+
+	retval = -EINVAL;
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == NULL) {
+			con_driver->con = csw;
+			con_driver->desc = desc;
+			con_driver->node = i;
+			con_driver->flag = CON_DRIVER_FLAG_MODULE |
+			                   CON_DRIVER_FLAG_INIT;
+			con_driver->first = first;
+			con_driver->last = last;
+			retval = 0;
+			break;
+		}
+	}
+
+	if (retval)
+		goto err;
+
+	con_driver->dev = device_create(vtconsole_class, NULL,
+						MKDEV(0, con_driver->node),
+						NULL, "vtcon%i",
+						con_driver->node);
+
+	if (IS_ERR(con_driver->dev)) {
+		printk(KERN_WARNING "Unable to create device for %s; "
+		       "errno = %ld\n", con_driver->desc,
+		       PTR_ERR(con_driver->dev));
+		con_driver->dev = NULL;
+	} else {
+		vtconsole_init_device(con_driver);
+	}
+
+err:
+	release_console_sem();
+	module_put(owner);
+	return retval;
+}
+EXPORT_SYMBOL(register_con_driver);
+
+/**
+ * unregister_con_driver - unregister console driver from console layer
+ * @csw: console driver
+ *
+ * DESCRIPTION: All drivers that registers to the console layer must
+ * call this function upon exit, or if the console driver is in a state
+ * where it won't be able to handle console services, such as the
+ * framebuffer console without loaded framebuffer drivers.
+ *
+ * The driver must unbind first prior to unregistration.
+ */
+int unregister_con_driver(const struct consw *csw)
+{
+	int i, retval = -ENODEV;
+
+	acquire_console_sem();
+
+	/* cannot unregister a bound driver */
+	if (con_is_bound(csw))
+		goto err;
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con_driver = &registered_con_driver[i];
+
+		if (con_driver->con == csw &&
+		    con_driver->flag & CON_DRIVER_FLAG_MODULE) {
+			vtconsole_deinit_device(con_driver);
+			device_destroy(vtconsole_class,
+				       MKDEV(0, con_driver->node));
+			con_driver->con = NULL;
+			con_driver->desc = NULL;
+			con_driver->dev = NULL;
+			con_driver->node = 0;
+			con_driver->flag = 0;
+			con_driver->first = 0;
+			con_driver->last = 0;
+			retval = 0;
+			break;
+		}
+	}
+err:
+	release_console_sem();
+	return retval;
+}
+EXPORT_SYMBOL(unregister_con_driver);
+
+/*
+ *	If we support more console drivers, this function is used
+ *	when a driver wants to take over some existing consoles
+ *	and become default driver for newly opened ones.
+ *
+ *      take_over_console is basically a register followed by unbind
+ */
+int take_over_console(const struct consw *csw, int first, int last, int deflt)
+{
+	int err;
+
+	err = register_con_driver(csw, first, last);
+
+	if (!err)
+		bind_con_driver(csw, first, last, deflt);
+
+	return err;
+}
+
+/*
+ * give_up_console is a wrapper to unregister_con_driver. It will only
+ * work if driver is fully unbound.
+ */
+void give_up_console(const struct consw *csw)
+{
+	unregister_con_driver(csw);
+}
+
+static int __init vtconsole_class_init(void)
+{
+	int i;
+
+	vtconsole_class = class_create(THIS_MODULE, "vtconsole");
+	if (IS_ERR(vtconsole_class)) {
+		printk(KERN_WARNING "Unable to create vt console class; "
+		       "errno = %ld\n", PTR_ERR(vtconsole_class));
+		vtconsole_class = NULL;
+	}
+
+	/* Add system drivers to sysfs */
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con = &registered_con_driver[i];
+
+		if (con->con && !con->dev) {
+			con->dev = device_create(vtconsole_class, NULL,
+							 MKDEV(0, con->node),
+							 NULL, "vtcon%i",
+							 con->node);
+
+			if (IS_ERR(con->dev)) {
+				printk(KERN_WARNING "Unable to create "
+				       "device for %s; errno = %ld\n",
+				       con->desc, PTR_ERR(con->dev));
+				con->dev = NULL;
+			} else {
+				vtconsole_init_device(con);
+			}
+		}
+	}
+
+	return 0;
+}
+postcore_initcall(vtconsole_class_init);
+
+#endif
+
+/*
+ *	Screen blanking
+ */
+
+static int set_vesa_blanking(char __user *p)
+{
+	unsigned int mode;
+
+	if (get_user(mode, p + 1))
+		return -EFAULT;
+
+	vesa_blank_mode = (mode < 4) ? mode : 0;
+	return 0;
+}
+
+void do_blank_screen(int entering_gfx)
+{
+	struct vc_data *vc = vc_cons[fg_console].d;
+	int i;
+
+	WARN_CONSOLE_UNLOCKED();
+
+	if (console_blanked) {
+		if (blank_state == blank_vesa_wait) {
+			blank_state = blank_off;
+			vc->vc_sw->con_blank(vc, vesa_blank_mode + 1, 0);
+		}
+		return;
+	}
+
+	/* entering graphics mode? */
+	if (entering_gfx) {
+		hide_cursor(vc);
+		save_screen(vc);
+		vc->vc_sw->con_blank(vc, -1, 1);
+		console_blanked = fg_console + 1;
+		blank_state = blank_off;
+		set_origin(vc);
+		return;
+	}
+
+	if (blank_state != blank_normal_wait)
+		return;
+	blank_state = blank_off;
+
+	/* don't blank graphics */
+	if (vc->vc_mode != KD_TEXT) {
+		console_blanked = fg_console + 1;
+		return;
+	}
+
+	hide_cursor(vc);
+	del_timer_sync(&console_timer);
+	blank_timer_expired = 0;
+
+	save_screen(vc);
+	/* In case we need to reset origin, blanking hook returns 1 */
+	i = vc->vc_sw->con_blank(vc, vesa_off_interval ? 1 : (vesa_blank_mode + 1), 0);
+	console_blanked = fg_console + 1;
+	if (i)
+		set_origin(vc);
+
+	if (console_blank_hook && console_blank_hook(1))
+		return;
+
+	if (vesa_off_interval && vesa_blank_mode) {
+		blank_state = blank_vesa_wait;
+		mod_timer(&console_timer, jiffies + vesa_off_interval);
+	}
+	vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num);
+}
+EXPORT_SYMBOL(do_blank_screen);
+
+/*
+ * Called by timer as well as from vt_console_driver
+ */
+void do_unblank_screen(int leaving_gfx)
+{
+	struct vc_data *vc;
+
+	/* This should now always be called from a "sane" (read: can schedule)
+	 * context for the sake of the low level drivers, except in the special
+	 * case of oops_in_progress
+	 */
+	if (!oops_in_progress)
+		might_sleep();
+
+	WARN_CONSOLE_UNLOCKED();
+
+	ignore_poke = 0;
+	if (!console_blanked)
+		return;
+	if (!vc_cons_allocated(fg_console)) {
+		/* impossible */
+		printk("unblank_screen: tty %d not allocated ??\n", fg_console+1);
+		return;
+	}
+	vc = vc_cons[fg_console].d;
+	/* Try to unblank in oops case too */
+	if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc))
+		return; /* but leave console_blanked != 0 */
+
+	if (blankinterval) {
+		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
+		blank_state = blank_normal_wait;
+	}
+
+	console_blanked = 0;
+	if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc))
+		/* Low-level driver cannot restore -> do it ourselves */
+		update_screen(vc);
+	if (console_blank_hook)
+		console_blank_hook(0);
+	set_palette(vc);
+	set_cursor(vc);
+	vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num);
+}
+EXPORT_SYMBOL(do_unblank_screen);
+
+/*
+ * This is called by the outside world to cause a forced unblank, mostly for
+ * oopses. Currently, I just call do_unblank_screen(0), but we could eventually
+ * call it with 1 as an argument and so force a mode restore... that may kill
+ * X or at least garbage the screen but would also make the Oops visible...
+ */
+void unblank_screen(void)
+{
+	do_unblank_screen(0);
+}
+
+/*
+ * We defer the timer blanking to work queue so it can take the console mutex
+ * (console operations can still happen at irq time, but only from printk which
+ * has the console mutex. Not perfect yet, but better than no locking
+ */
+static void blank_screen_t(unsigned long dummy)
+{
+	if (unlikely(!keventd_up())) {
+		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
+		return;
+	}
+	blank_timer_expired = 1;
+	schedule_work(&console_work);
+}
+
+void poke_blanked_console(void)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	/* Add this so we quickly catch whoever might call us in a non
+	 * safe context. Nowadays, unblank_screen() isn't to be called in
+	 * atomic contexts and is allowed to schedule (with the special case
+	 * of oops_in_progress, but that isn't of any concern for this
+	 * function. --BenH.
+	 */
+	might_sleep();
+
+	/* This isn't perfectly race free, but a race here would be mostly harmless,
+	 * at worse, we'll do a spurrious blank and it's unlikely
+	 */
+	del_timer(&console_timer);
+	blank_timer_expired = 0;
+
+	if (ignore_poke || !vc_cons[fg_console].d || vc_cons[fg_console].d->vc_mode == KD_GRAPHICS)
+		return;
+	if (console_blanked)
+		unblank_screen();
+	else if (blankinterval) {
+		mod_timer(&console_timer, jiffies + (blankinterval * HZ));
+		blank_state = blank_normal_wait;
+	}
+}
+
+/*
+ *	Palettes
+ */
+
+static void set_palette(struct vc_data *vc)
+{
+	WARN_CONSOLE_UNLOCKED();
+
+	if (vc->vc_mode != KD_GRAPHICS)
+		vc->vc_sw->con_set_palette(vc, color_table);
+}
+
+static int set_get_cmap(unsigned char __user *arg, int set)
+{
+    int i, j, k;
+
+    WARN_CONSOLE_UNLOCKED();
+
+    for (i = 0; i < 16; i++)
+	if (set) {
+	    get_user(default_red[i], arg++);
+	    get_user(default_grn[i], arg++);
+	    get_user(default_blu[i], arg++);
+	} else {
+	    put_user(default_red[i], arg++);
+	    put_user(default_grn[i], arg++);
+	    put_user(default_blu[i], arg++);
+	}
+    if (set) {
+	for (i = 0; i < MAX_NR_CONSOLES; i++)
+	    if (vc_cons_allocated(i)) {
+		for (j = k = 0; j < 16; j++) {
+		    vc_cons[i].d->vc_palette[k++] = default_red[j];
+		    vc_cons[i].d->vc_palette[k++] = default_grn[j];
+		    vc_cons[i].d->vc_palette[k++] = default_blu[j];
+		}
+		set_palette(vc_cons[i].d);
+	    }
+    }
+    return 0;
+}
+
+/*
+ * Load palette into the DAC registers. arg points to a colour
+ * map, 3 bytes per colour, 16 colours, range from 0 to 255.
+ */
+
+int con_set_cmap(unsigned char __user *arg)
+{
+	int rc;
+
+	acquire_console_sem();
+	rc = set_get_cmap (arg,1);
+	release_console_sem();
+
+	return rc;
+}
+
+int con_get_cmap(unsigned char __user *arg)
+{
+	int rc;
+
+	acquire_console_sem();
+	rc = set_get_cmap (arg,0);
+	release_console_sem();
+
+	return rc;
+}
+
+void reset_palette(struct vc_data *vc)
+{
+	int j, k;
+	for (j=k=0; j<16; j++) {
+		vc->vc_palette[k++] = default_red[j];
+		vc->vc_palette[k++] = default_grn[j];
+		vc->vc_palette[k++] = default_blu[j];
+	}
+	set_palette(vc);
+}
+
+/*
+ *  Font switching
+ *
+ *  Currently we only support fonts up to 32 pixels wide, at a maximum height
+ *  of 32 pixels. Userspace fontdata is stored with 32 bytes (shorts/ints, 
+ *  depending on width) reserved for each character which is kinda wasty, but 
+ *  this is done in order to maintain compatibility with the EGA/VGA fonts. It 
+ *  is upto the actual low-level console-driver convert data into its favorite
+ *  format (maybe we should add a `fontoffset' field to the `display'
+ *  structure so we won't have to convert the fontdata all the time.
+ *  /Jes
+ */
+
+#define max_font_size 65536
+
+static int con_font_get(struct vc_data *vc, struct console_font_op *op)
+{
+	struct console_font font;
+	int rc = -EINVAL;
+	int c;
+
+	if (vc->vc_mode != KD_TEXT)
+		return -EINVAL;
+
+	if (op->data) {
+		font.data = kmalloc(max_font_size, GFP_KERNEL);
+		if (!font.data)
+			return -ENOMEM;
+	} else
+		font.data = NULL;
+
+	acquire_console_sem();
+	if (vc->vc_sw->con_font_get)
+		rc = vc->vc_sw->con_font_get(vc, &font);
+	else
+		rc = -ENOSYS;
+	release_console_sem();
+
+	if (rc)
+		goto out;
+
+	c = (font.width+7)/8 * 32 * font.charcount;
+
+	if (op->data && font.charcount > op->charcount)
+		rc = -ENOSPC;
+	if (!(op->flags & KD_FONT_FLAG_OLD)) {
+		if (font.width > op->width || font.height > op->height) 
+			rc = -ENOSPC;
+	} else {
+		if (font.width != 8)
+			rc = -EIO;
+		else if ((op->height && font.height > op->height) ||
+			 font.height > 32)
+			rc = -ENOSPC;
+	}
+	if (rc)
+		goto out;
+
+	op->height = font.height;
+	op->width = font.width;
+	op->charcount = font.charcount;
+
+	if (op->data && copy_to_user(op->data, font.data, c))
+		rc = -EFAULT;
+
+out:
+	kfree(font.data);
+	return rc;
+}
+
+static int con_font_set(struct vc_data *vc, struct console_font_op *op)
+{
+	struct console_font font;
+	int rc = -EINVAL;
+	int size;
+
+	if (vc->vc_mode != KD_TEXT)
+		return -EINVAL;
+	if (!op->data)
+		return -EINVAL;
+	if (op->charcount > 512)
+		return -EINVAL;
+	if (!op->height) {		/* Need to guess font height [compat] */
+		int h, i;
+		u8 __user *charmap = op->data;
+		u8 tmp;
+		
+		/* If from KDFONTOP ioctl, don't allow things which can be done in userland,
+		   so that we can get rid of this soon */
+		if (!(op->flags & KD_FONT_FLAG_OLD))
+			return -EINVAL;
+		for (h = 32; h > 0; h--)
+			for (i = 0; i < op->charcount; i++) {
+				if (get_user(tmp, &charmap[32*i+h-1]))
+					return -EFAULT;
+				if (tmp)
+					goto nonzero;
+			}
+		return -EINVAL;
+	nonzero:
+		op->height = h;
+	}
+	if (op->width <= 0 || op->width > 32 || op->height > 32)
+		return -EINVAL;
+	size = (op->width+7)/8 * 32 * op->charcount;
+	if (size > max_font_size)
+		return -ENOSPC;
+	font.charcount = op->charcount;
+	font.height = op->height;
+	font.width = op->width;
+	font.data = memdup_user(op->data, size);
+	if (IS_ERR(font.data))
+		return PTR_ERR(font.data);
+	acquire_console_sem();
+	if (vc->vc_sw->con_font_set)
+		rc = vc->vc_sw->con_font_set(vc, &font, op->flags);
+	else
+		rc = -ENOSYS;
+	release_console_sem();
+	kfree(font.data);
+	return rc;
+}
+
+static int con_font_default(struct vc_data *vc, struct console_font_op *op)
+{
+	struct console_font font = {.width = op->width, .height = op->height};
+	char name[MAX_FONT_NAME];
+	char *s = name;
+	int rc;
+
+	if (vc->vc_mode != KD_TEXT)
+		return -EINVAL;
+
+	if (!op->data)
+		s = NULL;
+	else if (strncpy_from_user(name, op->data, MAX_FONT_NAME - 1) < 0)
+		return -EFAULT;
+	else
+		name[MAX_FONT_NAME - 1] = 0;
+
+	acquire_console_sem();
+	if (vc->vc_sw->con_font_default)
+		rc = vc->vc_sw->con_font_default(vc, &font, s);
+	else
+		rc = -ENOSYS;
+	release_console_sem();
+	if (!rc) {
+		op->width = font.width;
+		op->height = font.height;
+	}
+	return rc;
+}
+
+static int con_font_copy(struct vc_data *vc, struct console_font_op *op)
+{
+	int con = op->height;
+	int rc;
+
+	if (vc->vc_mode != KD_TEXT)
+		return -EINVAL;
+
+	acquire_console_sem();
+	if (!vc->vc_sw->con_font_copy)
+		rc = -ENOSYS;
+	else if (con < 0 || !vc_cons_allocated(con))
+		rc = -ENOTTY;
+	else if (con == vc->vc_num)	/* nothing to do */
+		rc = 0;
+	else
+		rc = vc->vc_sw->con_font_copy(vc, con);
+	release_console_sem();
+	return rc;
+}
+
+int con_font_op(struct vc_data *vc, struct console_font_op *op)
+{
+	switch (op->op) {
+	case KD_FONT_OP_SET:
+		return con_font_set(vc, op);
+	case KD_FONT_OP_GET:
+		return con_font_get(vc, op);
+	case KD_FONT_OP_SET_DEFAULT:
+		return con_font_default(vc, op);
+	case KD_FONT_OP_COPY:
+		return con_font_copy(vc, op);
+	}
+	return -ENOSYS;
+}
+
+/*
+ *	Interface exported to selection and vcs.
+ */
+
+/* used by selection */
+u16 screen_glyph(struct vc_data *vc, int offset)
+{
+	u16 w = scr_readw(screenpos(vc, offset, 1));
+	u16 c = w & 0xff;
+
+	if (w & vc->vc_hi_font_mask)
+		c |= 0x100;
+	return c;
+}
+EXPORT_SYMBOL_GPL(screen_glyph);
+
+/* used by vcs - note the word offset */
+unsigned short *screen_pos(struct vc_data *vc, int w_offset, int viewed)
+{
+	return screenpos(vc, 2 * w_offset, viewed);
+}
+
+void getconsxy(struct vc_data *vc, unsigned char *p)
+{
+	p[0] = vc->vc_x;
+	p[1] = vc->vc_y;
+}
+
+void putconsxy(struct vc_data *vc, unsigned char *p)
+{
+	hide_cursor(vc);
+	gotoxy(vc, p[0], p[1]);
+	set_cursor(vc);
+}
+
+u16 vcs_scr_readw(struct vc_data *vc, const u16 *org)
+{
+	if ((unsigned long)org == vc->vc_pos && softcursor_original != -1)
+		return softcursor_original;
+	return scr_readw(org);
+}
+
+void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
+{
+	scr_writew(val, org);
+	if ((unsigned long)org == vc->vc_pos) {
+		softcursor_original = -1;
+		add_softcursor(vc);
+	}
+}
+
+void vcs_scr_updated(struct vc_data *vc)
+{
+	notify_update(vc);
+}
+
+/*
+ *	Visible symbols for modules
+ */
+
+EXPORT_SYMBOL(color_table);
+EXPORT_SYMBOL(default_red);
+EXPORT_SYMBOL(default_grn);
+EXPORT_SYMBOL(default_blu);
+EXPORT_SYMBOL(update_region);
+EXPORT_SYMBOL(redraw_screen);
+EXPORT_SYMBOL(vc_resize);
+EXPORT_SYMBOL(fg_console);
+EXPORT_SYMBOL(console_blank_hook);
+EXPORT_SYMBOL(console_blanked);
+EXPORT_SYMBOL(vc_cons);
+EXPORT_SYMBOL(global_cursor_default);
+#ifndef VT_SINGLE_DRIVER
+EXPORT_SYMBOL(take_over_console);
+EXPORT_SYMBOL(give_up_console);
+#endif
diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
new file mode 100644
index 0000000..6b68a0f
--- /dev/null
+++ b/drivers/tty/vt/vt_ioctl.c
@@ -0,0 +1,1788 @@
+/*
+ *  linux/drivers/char/vt_ioctl.c
+ *
+ *  Copyright (C) 1992 obz under the linux copyright
+ *
+ *  Dynamic diacritical handling - aeb@cwi.nl - Dec 1993
+ *  Dynamic keymap and string allocation - aeb@cwi.nl - May 1994
+ *  Restrict VT switching via ioctl() - grif@cs.ucr.edu - Dec 1995
+ *  Some code moved for less code duplication - Andi Kleen - Mar 1997
+ *  Check put/get_user, cleanups - acme@conectiva.com.br - Jun 2001
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/tty.h>
+#include <linux/timer.h>
+#include <linux/kernel.h>
+#include <linux/compat.h>
+#include <linux/module.h>
+#include <linux/kd.h>
+#include <linux/vt.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/major.h>
+#include <linux/fs.h>
+#include <linux/console.h>
+#include <linux/consolemap.h>
+#include <linux/signal.h>
+#include <linux/smp_lock.h>
+#include <linux/timex.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/kbd_diacr.h>
+#include <linux/selection.h>
+
+char vt_dont_switch;
+extern struct tty_driver *console_driver;
+
+#define VT_IS_IN_USE(i)	(console_driver->ttys[i] && console_driver->ttys[i]->count)
+#define VT_BUSY(i)	(VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
+
+/*
+ * Console (vt and kd) routines, as defined by USL SVR4 manual, and by
+ * experimentation and study of X386 SYSV handling.
+ *
+ * One point of difference: SYSV vt's are /dev/vtX, which X >= 0, and
+ * /dev/console is a separate ttyp. Under Linux, /dev/tty0 is /dev/console,
+ * and the vc start at /dev/ttyX, X >= 1. We maintain that here, so we will
+ * always treat our set of vt as numbered 1..MAX_NR_CONSOLES (corresponding to
+ * ttys 0..MAX_NR_CONSOLES-1). Explicitly naming VT 0 is illegal, but using
+ * /dev/tty0 (fg_console) as a target is legal, since an implicit aliasing
+ * to the current console is done by the main ioctl code.
+ */
+
+#ifdef CONFIG_X86
+#include <linux/syscalls.h>
+#endif
+
+static void complete_change_console(struct vc_data *vc);
+
+/*
+ *	User space VT_EVENT handlers
+ */
+
+struct vt_event_wait {
+	struct list_head list;
+	struct vt_event event;
+	int done;
+};
+
+static LIST_HEAD(vt_events);
+static DEFINE_SPINLOCK(vt_event_lock);
+static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
+
+/**
+ *	vt_event_post
+ *	@event: the event that occurred
+ *	@old: old console
+ *	@new: new console
+ *
+ *	Post an VT event to interested VT handlers
+ */
+
+void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
+{
+	struct list_head *pos, *head;
+	unsigned long flags;
+	int wake = 0;
+
+	spin_lock_irqsave(&vt_event_lock, flags);
+	head = &vt_events;
+
+	list_for_each(pos, head) {
+		struct vt_event_wait *ve = list_entry(pos,
+						struct vt_event_wait, list);
+		if (!(ve->event.event & event))
+			continue;
+		ve->event.event = event;
+		/* kernel view is consoles 0..n-1, user space view is
+		   console 1..n with 0 meaning current, so we must bias */
+		ve->event.oldev = old + 1;
+		ve->event.newev = new + 1;
+		wake = 1;
+		ve->done = 1;
+	}
+	spin_unlock_irqrestore(&vt_event_lock, flags);
+	if (wake)
+		wake_up_interruptible(&vt_event_waitqueue);
+}
+
+/**
+ *	vt_event_wait		-	wait for an event
+ *	@vw: our event
+ *
+ *	Waits for an event to occur which completes our vt_event_wait
+ *	structure. On return the structure has wv->done set to 1 for success
+ *	or 0 if some event such as a signal ended the wait.
+ */
+
+static void vt_event_wait(struct vt_event_wait *vw)
+{
+	unsigned long flags;
+	/* Prepare the event */
+	INIT_LIST_HEAD(&vw->list);
+	vw->done = 0;
+	/* Queue our event */
+	spin_lock_irqsave(&vt_event_lock, flags);
+	list_add(&vw->list, &vt_events);
+	spin_unlock_irqrestore(&vt_event_lock, flags);
+	/* Wait for it to pass */
+	wait_event_interruptible_tty(vt_event_waitqueue, vw->done);
+	/* Dequeue it */
+	spin_lock_irqsave(&vt_event_lock, flags);
+	list_del(&vw->list);
+	spin_unlock_irqrestore(&vt_event_lock, flags);
+}
+
+/**
+ *	vt_event_wait_ioctl	-	event ioctl handler
+ *	@arg: argument to ioctl
+ *
+ *	Implement the VT_WAITEVENT ioctl using the VT event interface
+ */
+
+static int vt_event_wait_ioctl(struct vt_event __user *event)
+{
+	struct vt_event_wait vw;
+
+	if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
+		return -EFAULT;
+	/* Highest supported event for now */
+	if (vw.event.event & ~VT_MAX_EVENT)
+		return -EINVAL;
+
+	vt_event_wait(&vw);
+	/* If it occurred report it */
+	if (vw.done) {
+		if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
+			return -EFAULT;
+		return 0;
+	}
+	return -EINTR;
+}
+
+/**
+ *	vt_waitactive	-	active console wait
+ *	@event: event code
+ *	@n: new console
+ *
+ *	Helper for event waits. Used to implement the legacy
+ *	event waiting ioctls in terms of events
+ */
+
+int vt_waitactive(int n)
+{
+	struct vt_event_wait vw;
+	do {
+		if (n == fg_console + 1)
+			break;
+		vw.event.event = VT_EVENT_SWITCH;
+		vt_event_wait(&vw);
+		if (vw.done == 0)
+			return -EINTR;
+	} while (vw.event.newev != n);
+	return 0;
+}
+
+/*
+ * these are the valid i/o ports we're allowed to change. they map all the
+ * video ports
+ */
+#define GPFIRST 0x3b4
+#define GPLAST 0x3df
+#define GPNUM (GPLAST - GPFIRST + 1)
+
+#define i (tmp.kb_index)
+#define s (tmp.kb_table)
+#define v (tmp.kb_value)
+static inline int
+do_kdsk_ioctl(int cmd, struct kbentry __user *user_kbe, int perm, struct kbd_struct *kbd)
+{
+	struct kbentry tmp;
+	ushort *key_map, val, ov;
+
+	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
+		return -EFAULT;
+
+	if (!capable(CAP_SYS_TTY_CONFIG))
+		perm = 0;
+
+	switch (cmd) {
+	case KDGKBENT:
+		key_map = key_maps[s];
+		if (key_map) {
+		    val = U(key_map[i]);
+		    if (kbd->kbdmode != VC_UNICODE && KTYP(val) >= NR_TYPES)
+			val = K_HOLE;
+		} else
+		    val = (i ? K_HOLE : K_NOSUCHMAP);
+		return put_user(val, &user_kbe->kb_value);
+	case KDSKBENT:
+		if (!perm)
+			return -EPERM;
+		if (!i && v == K_NOSUCHMAP) {
+			/* deallocate map */
+			key_map = key_maps[s];
+			if (s && key_map) {
+			    key_maps[s] = NULL;
+			    if (key_map[0] == U(K_ALLOCATED)) {
+					kfree(key_map);
+					keymap_count--;
+			    }
+			}
+			break;
+		}
+
+		if (KTYP(v) < NR_TYPES) {
+		    if (KVAL(v) > max_vals[KTYP(v)])
+				return -EINVAL;
+		} else
+		    if (kbd->kbdmode != VC_UNICODE)
+				return -EINVAL;
+
+		/* ++Geert: non-PC keyboards may generate keycode zero */
+#if !defined(__mc68000__) && !defined(__powerpc__)
+		/* assignment to entry 0 only tests validity of args */
+		if (!i)
+			break;
+#endif
+
+		if (!(key_map = key_maps[s])) {
+			int j;
+
+			if (keymap_count >= MAX_NR_OF_USER_KEYMAPS &&
+			    !capable(CAP_SYS_RESOURCE))
+				return -EPERM;
+
+			key_map = kmalloc(sizeof(plain_map),
+						     GFP_KERNEL);
+			if (!key_map)
+				return -ENOMEM;
+			key_maps[s] = key_map;
+			key_map[0] = U(K_ALLOCATED);
+			for (j = 1; j < NR_KEYS; j++)
+				key_map[j] = U(K_HOLE);
+			keymap_count++;
+		}
+		ov = U(key_map[i]);
+		if (v == ov)
+			break;	/* nothing to do */
+		/*
+		 * Attention Key.
+		 */
+		if (((ov == K_SAK) || (v == K_SAK)) && !capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		key_map[i] = U(v);
+		if (!s && (KTYP(ov) == KT_SHIFT || KTYP(v) == KT_SHIFT))
+			compute_shiftstate();
+		break;
+	}
+	return 0;
+}
+#undef i
+#undef s
+#undef v
+
+static inline int 
+do_kbkeycode_ioctl(int cmd, struct kbkeycode __user *user_kbkc, int perm)
+{
+	struct kbkeycode tmp;
+	int kc = 0;
+
+	if (copy_from_user(&tmp, user_kbkc, sizeof(struct kbkeycode)))
+		return -EFAULT;
+	switch (cmd) {
+	case KDGETKEYCODE:
+		kc = getkeycode(tmp.scancode);
+		if (kc >= 0)
+			kc = put_user(kc, &user_kbkc->keycode);
+		break;
+	case KDSETKEYCODE:
+		if (!perm)
+			return -EPERM;
+		kc = setkeycode(tmp.scancode, tmp.keycode);
+		break;
+	}
+	return kc;
+}
+
+static inline int
+do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
+{
+	struct kbsentry *kbs;
+	char *p;
+	u_char *q;
+	u_char __user *up;
+	int sz;
+	int delta;
+	char *first_free, *fj, *fnw;
+	int i, j, k;
+	int ret;
+
+	if (!capable(CAP_SYS_TTY_CONFIG))
+		perm = 0;
+
+	kbs = kmalloc(sizeof(*kbs), GFP_KERNEL);
+	if (!kbs) {
+		ret = -ENOMEM;
+		goto reterr;
+	}
+
+	/* we mostly copy too much here (512bytes), but who cares ;) */
+	if (copy_from_user(kbs, user_kdgkb, sizeof(struct kbsentry))) {
+		ret = -EFAULT;
+		goto reterr;
+	}
+	kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0';
+	i = kbs->kb_func;
+
+	switch (cmd) {
+	case KDGKBSENT:
+		sz = sizeof(kbs->kb_string) - 1; /* sz should have been
+						  a struct member */
+		up = user_kdgkb->kb_string;
+		p = func_table[i];
+		if(p)
+			for ( ; *p && sz; p++, sz--)
+				if (put_user(*p, up++)) {
+					ret = -EFAULT;
+					goto reterr;
+				}
+		if (put_user('\0', up)) {
+			ret = -EFAULT;
+			goto reterr;
+		}
+		kfree(kbs);
+		return ((p && *p) ? -EOVERFLOW : 0);
+	case KDSKBSENT:
+		if (!perm) {
+			ret = -EPERM;
+			goto reterr;
+		}
+
+		q = func_table[i];
+		first_free = funcbufptr + (funcbufsize - funcbufleft);
+		for (j = i+1; j < MAX_NR_FUNC && !func_table[j]; j++) 
+			;
+		if (j < MAX_NR_FUNC)
+			fj = func_table[j];
+		else
+			fj = first_free;
+
+		delta = (q ? -strlen(q) : 1) + strlen(kbs->kb_string);
+		if (delta <= funcbufleft) { 	/* it fits in current buf */
+		    if (j < MAX_NR_FUNC) {
+			memmove(fj + delta, fj, first_free - fj);
+			for (k = j; k < MAX_NR_FUNC; k++)
+			    if (func_table[k])
+				func_table[k] += delta;
+		    }
+		    if (!q)
+		      func_table[i] = fj;
+		    funcbufleft -= delta;
+		} else {			/* allocate a larger buffer */
+		    sz = 256;
+		    while (sz < funcbufsize - funcbufleft + delta)
+		      sz <<= 1;
+		    fnw = kmalloc(sz, GFP_KERNEL);
+		    if(!fnw) {
+		      ret = -ENOMEM;
+		      goto reterr;
+		    }
+
+		    if (!q)
+		      func_table[i] = fj;
+		    if (fj > funcbufptr)
+			memmove(fnw, funcbufptr, fj - funcbufptr);
+		    for (k = 0; k < j; k++)
+		      if (func_table[k])
+			func_table[k] = fnw + (func_table[k] - funcbufptr);
+
+		    if (first_free > fj) {
+			memmove(fnw + (fj - funcbufptr) + delta, fj, first_free - fj);
+			for (k = j; k < MAX_NR_FUNC; k++)
+			  if (func_table[k])
+			    func_table[k] = fnw + (func_table[k] - funcbufptr) + delta;
+		    }
+		    if (funcbufptr != func_buf)
+		      kfree(funcbufptr);
+		    funcbufptr = fnw;
+		    funcbufleft = funcbufleft - delta + sz - funcbufsize;
+		    funcbufsize = sz;
+		}
+		strcpy(func_table[i], kbs->kb_string);
+		break;
+	}
+	ret = 0;
+reterr:
+	kfree(kbs);
+	return ret;
+}
+
+static inline int 
+do_fontx_ioctl(int cmd, struct consolefontdesc __user *user_cfd, int perm, struct console_font_op *op)
+{
+	struct consolefontdesc cfdarg;
+	int i;
+
+	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct consolefontdesc))) 
+		return -EFAULT;
+ 	
+	switch (cmd) {
+	case PIO_FONTX:
+		if (!perm)
+			return -EPERM;
+		op->op = KD_FONT_OP_SET;
+		op->flags = KD_FONT_FLAG_OLD;
+		op->width = 8;
+		op->height = cfdarg.charheight;
+		op->charcount = cfdarg.charcount;
+		op->data = cfdarg.chardata;
+		return con_font_op(vc_cons[fg_console].d, op);
+	case GIO_FONTX: {
+		op->op = KD_FONT_OP_GET;
+		op->flags = KD_FONT_FLAG_OLD;
+		op->width = 8;
+		op->height = cfdarg.charheight;
+		op->charcount = cfdarg.charcount;
+		op->data = cfdarg.chardata;
+		i = con_font_op(vc_cons[fg_console].d, op);
+		if (i)
+			return i;
+		cfdarg.charheight = op->height;
+		cfdarg.charcount = op->charcount;
+		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct consolefontdesc)))
+			return -EFAULT;
+		return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+static inline int 
+do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_data *vc)
+{
+	struct unimapdesc tmp;
+
+	if (copy_from_user(&tmp, user_ud, sizeof tmp))
+		return -EFAULT;
+	if (tmp.entries)
+		if (!access_ok(VERIFY_WRITE, tmp.entries,
+				tmp.entry_ct*sizeof(struct unipair)))
+			return -EFAULT;
+	switch (cmd) {
+	case PIO_UNIMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
+	case GIO_UNIMAP:
+		if (!perm && fg_console != vc->vc_num)
+			return -EPERM;
+		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp.entries);
+	}
+	return 0;
+}
+
+
+
+/*
+ * We handle the console-specific ioctl's here.  We allow the
+ * capability to modify any console, not just the fg_console. 
+ */
+int vt_ioctl(struct tty_struct *tty, struct file * file,
+	     unsigned int cmd, unsigned long arg)
+{
+	struct vc_data *vc = tty->driver_data;
+	struct console_font_op op;	/* used in multiple places here */
+	struct kbd_struct * kbd;
+	unsigned int console;
+	unsigned char ucval;
+	unsigned int uival;
+	void __user *up = (void __user *)arg;
+	int i, perm;
+	int ret = 0;
+
+	console = vc->vc_num;
+
+	tty_lock();
+
+	if (!vc_cons_allocated(console)) { 	/* impossible? */
+		ret = -ENOIOCTLCMD;
+		goto out;
+	}
+
+
+	/*
+	 * To have permissions to do most of the vt ioctls, we either have
+	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
+	 */
+	perm = 0;
+	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
+		perm = 1;
+ 
+	kbd = kbd_table + console;
+	switch (cmd) {
+	case TIOCLINUX:
+		ret = tioclinux(tty, arg);
+		break;
+	case KIOCSOUND:
+		if (!perm)
+			goto eperm;
+		/*
+		 * The use of PIT_TICK_RATE is historic, it used to be
+		 * the platform-dependent CLOCK_TICK_RATE between 2.6.12
+		 * and 2.6.36, which was a minor but unfortunate ABI
+		 * change.
+		 */
+		if (arg)
+			arg = PIT_TICK_RATE / arg;
+		kd_mksound(arg, 0);
+		break;
+
+	case KDMKTONE:
+		if (!perm)
+			goto eperm;
+	{
+		unsigned int ticks, count;
+		
+		/*
+		 * Generate the tone for the appropriate number of ticks.
+		 * If the time is zero, turn off sound ourselves.
+		 */
+		ticks = HZ * ((arg >> 16) & 0xffff) / 1000;
+		count = ticks ? (arg & 0xffff) : 0;
+		if (count)
+			count = PIT_TICK_RATE / count;
+		kd_mksound(count, ticks);
+		break;
+	}
+
+	case KDGKBTYPE:
+		/*
+		 * this is naive.
+		 */
+		ucval = KB_101;
+		goto setchar;
+
+		/*
+		 * These cannot be implemented on any machine that implements
+		 * ioperm() in user level (such as Alpha PCs) or not at all.
+		 *
+		 * XXX: you should never use these, just call ioperm directly..
+		 */
+#ifdef CONFIG_X86
+	case KDADDIO:
+	case KDDELIO:
+		/*
+		 * KDADDIO and KDDELIO may be able to add ports beyond what
+		 * we reject here, but to be safe...
+		 */
+		if (arg < GPFIRST || arg > GPLAST) {
+			ret = -EINVAL;
+			break;
+		}
+		ret = sys_ioperm(arg, 1, (cmd == KDADDIO)) ? -ENXIO : 0;
+		break;
+
+	case KDENABIO:
+	case KDDISABIO:
+		ret = sys_ioperm(GPFIRST, GPNUM,
+				  (cmd == KDENABIO)) ? -ENXIO : 0;
+		break;
+#endif
+
+	/* Linux m68k/i386 interface for setting the keyboard delay/repeat rate */
+		
+	case KDKBDREP:
+	{
+		struct kbd_repeat kbrep;
+		
+		if (!capable(CAP_SYS_TTY_CONFIG))
+			goto eperm;
+
+		if (copy_from_user(&kbrep, up, sizeof(struct kbd_repeat))) {
+			ret =  -EFAULT;
+			break;
+		}
+		ret = kbd_rate(&kbrep);
+		if (ret)
+			break;
+		if (copy_to_user(up, &kbrep, sizeof(struct kbd_repeat)))
+			ret = -EFAULT;
+		break;
+	}
+
+	case KDSETMODE:
+		/*
+		 * currently, setting the mode from KD_TEXT to KD_GRAPHICS
+		 * doesn't do a whole lot. i'm not sure if it should do any
+		 * restoration of modes or what...
+		 *
+		 * XXX It should at least call into the driver, fbdev's definitely
+		 * need to restore their engine state. --BenH
+		 */
+		if (!perm)
+			goto eperm;
+		switch (arg) {
+		case KD_GRAPHICS:
+			break;
+		case KD_TEXT0:
+		case KD_TEXT1:
+			arg = KD_TEXT;
+		case KD_TEXT:
+			break;
+		default:
+			ret = -EINVAL;
+			goto out;
+		}
+		if (vc->vc_mode == (unsigned char) arg)
+			break;
+		vc->vc_mode = (unsigned char) arg;
+		if (console != fg_console)
+			break;
+		/*
+		 * explicitly blank/unblank the screen if switching modes
+		 */
+		acquire_console_sem();
+		if (arg == KD_TEXT)
+			do_unblank_screen(1);
+		else
+			do_blank_screen(1);
+		release_console_sem();
+		break;
+
+	case KDGETMODE:
+		uival = vc->vc_mode;
+		goto setint;
+
+	case KDMAPDISP:
+	case KDUNMAPDISP:
+		/*
+		 * these work like a combination of mmap and KDENABIO.
+		 * this could be easily finished.
+		 */
+		ret = -EINVAL;
+		break;
+
+	case KDSKBMODE:
+		if (!perm)
+			goto eperm;
+		switch(arg) {
+		  case K_RAW:
+			kbd->kbdmode = VC_RAW;
+			break;
+		  case K_MEDIUMRAW:
+			kbd->kbdmode = VC_MEDIUMRAW;
+			break;
+		  case K_XLATE:
+			kbd->kbdmode = VC_XLATE;
+			compute_shiftstate();
+			break;
+		  case K_UNICODE:
+			kbd->kbdmode = VC_UNICODE;
+			compute_shiftstate();
+			break;
+		  default:
+			ret = -EINVAL;
+			goto out;
+		}
+		tty_ldisc_flush(tty);
+		break;
+
+	case KDGKBMODE:
+		uival = ((kbd->kbdmode == VC_RAW) ? K_RAW :
+				 (kbd->kbdmode == VC_MEDIUMRAW) ? K_MEDIUMRAW :
+				 (kbd->kbdmode == VC_UNICODE) ? K_UNICODE :
+				 K_XLATE);
+		goto setint;
+
+	/* this could be folded into KDSKBMODE, but for compatibility
+	   reasons it is not so easy to fold KDGKBMETA into KDGKBMODE */
+	case KDSKBMETA:
+		switch(arg) {
+		  case K_METABIT:
+			clr_vc_kbd_mode(kbd, VC_META);
+			break;
+		  case K_ESCPREFIX:
+			set_vc_kbd_mode(kbd, VC_META);
+			break;
+		  default:
+			ret = -EINVAL;
+		}
+		break;
+
+	case KDGKBMETA:
+		uival = (vc_kbd_mode(kbd, VC_META) ? K_ESCPREFIX : K_METABIT);
+	setint:
+		ret = put_user(uival, (int __user *)arg);
+		break;
+
+	case KDGETKEYCODE:
+	case KDSETKEYCODE:
+		if(!capable(CAP_SYS_TTY_CONFIG))
+			perm = 0;
+		ret = do_kbkeycode_ioctl(cmd, up, perm);
+		break;
+
+	case KDGKBENT:
+	case KDSKBENT:
+		ret = do_kdsk_ioctl(cmd, up, perm, kbd);
+		break;
+
+	case KDGKBSENT:
+	case KDSKBSENT:
+		ret = do_kdgkb_ioctl(cmd, up, perm);
+		break;
+
+	case KDGKBDIACR:
+	{
+		struct kbdiacrs __user *a = up;
+		struct kbdiacr diacr;
+		int i;
+
+		if (put_user(accent_table_size, &a->kb_cnt)) {
+			ret = -EFAULT;
+			break;
+		}
+		for (i = 0; i < accent_table_size; i++) {
+			diacr.diacr = conv_uni_to_8bit(accent_table[i].diacr);
+			diacr.base = conv_uni_to_8bit(accent_table[i].base);
+			diacr.result = conv_uni_to_8bit(accent_table[i].result);
+			if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr))) {
+				ret = -EFAULT;
+				break;
+			}
+		}
+		break;
+	}
+	case KDGKBDIACRUC:
+	{
+		struct kbdiacrsuc __user *a = up;
+
+		if (put_user(accent_table_size, &a->kb_cnt))
+			ret = -EFAULT;
+		else if (copy_to_user(a->kbdiacruc, accent_table,
+				accent_table_size*sizeof(struct kbdiacruc)))
+			ret = -EFAULT;
+		break;
+	}
+
+	case KDSKBDIACR:
+	{
+		struct kbdiacrs __user *a = up;
+		struct kbdiacr diacr;
+		unsigned int ct;
+		int i;
+
+		if (!perm)
+			goto eperm;
+		if (get_user(ct,&a->kb_cnt)) {
+			ret = -EFAULT;
+			break;
+		}
+		if (ct >= MAX_DIACR) {
+			ret = -EINVAL;
+			break;
+		}
+		accent_table_size = ct;
+		for (i = 0; i < ct; i++) {
+			if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr))) {
+				ret = -EFAULT;
+				break;
+			}
+			accent_table[i].diacr = conv_8bit_to_uni(diacr.diacr);
+			accent_table[i].base = conv_8bit_to_uni(diacr.base);
+			accent_table[i].result = conv_8bit_to_uni(diacr.result);
+		}
+		break;
+	}
+
+	case KDSKBDIACRUC:
+	{
+		struct kbdiacrsuc __user *a = up;
+		unsigned int ct;
+
+		if (!perm)
+			goto eperm;
+		if (get_user(ct,&a->kb_cnt)) {
+			ret = -EFAULT;
+			break;
+		}
+		if (ct >= MAX_DIACR) {
+			ret = -EINVAL;
+			break;
+		}
+		accent_table_size = ct;
+		if (copy_from_user(accent_table, a->kbdiacruc, ct*sizeof(struct kbdiacruc)))
+			ret = -EFAULT;
+		break;
+	}
+
+	/* the ioctls below read/set the flags usually shown in the leds */
+	/* don't use them - they will go away without warning */
+	case KDGKBLED:
+		ucval = kbd->ledflagstate | (kbd->default_ledflagstate << 4);
+		goto setchar;
+
+	case KDSKBLED:
+		if (!perm)
+			goto eperm;
+		if (arg & ~0x77) {
+			ret = -EINVAL;
+			break;
+		}
+		kbd->ledflagstate = (arg & 7);
+		kbd->default_ledflagstate = ((arg >> 4) & 7);
+		set_leds();
+		break;
+
+	/* the ioctls below only set the lights, not the functions */
+	/* for those, see KDGKBLED and KDSKBLED above */
+	case KDGETLED:
+		ucval = getledstate();
+	setchar:
+		ret = put_user(ucval, (char __user *)arg);
+		break;
+
+	case KDSETLED:
+		if (!perm)
+			goto eperm;
+		setledstate(kbd, arg);
+		break;
+
+	/*
+	 * A process can indicate its willingness to accept signals
+	 * generated by pressing an appropriate key combination.
+	 * Thus, one can have a daemon that e.g. spawns a new console
+	 * upon a keypress and then changes to it.
+	 * See also the kbrequest field of inittab(5).
+	 */
+	case KDSIGACCEPT:
+	{
+		if (!perm || !capable(CAP_KILL))
+			goto eperm;
+		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
+			ret = -EINVAL;
+		else {
+			spin_lock_irq(&vt_spawn_con.lock);
+			put_pid(vt_spawn_con.pid);
+			vt_spawn_con.pid = get_pid(task_pid(current));
+			vt_spawn_con.sig = arg;
+			spin_unlock_irq(&vt_spawn_con.lock);
+		}
+		break;
+	}
+
+	case VT_SETMODE:
+	{
+		struct vt_mode tmp;
+
+		if (!perm)
+			goto eperm;
+		if (copy_from_user(&tmp, up, sizeof(struct vt_mode))) {
+			ret = -EFAULT;
+			goto out;
+		}
+		if (tmp.mode != VT_AUTO && tmp.mode != VT_PROCESS) {
+			ret = -EINVAL;
+			goto out;
+		}
+		acquire_console_sem();
+		vc->vt_mode = tmp;
+		/* the frsig is ignored, so we set it to 0 */
+		vc->vt_mode.frsig = 0;
+		put_pid(vc->vt_pid);
+		vc->vt_pid = get_pid(task_pid(current));
+		/* no switch is required -- saw@shade.msu.ru */
+		vc->vt_newvt = -1;
+		release_console_sem();
+		break;
+	}
+
+	case VT_GETMODE:
+	{
+		struct vt_mode tmp;
+		int rc;
+
+		acquire_console_sem();
+		memcpy(&tmp, &vc->vt_mode, sizeof(struct vt_mode));
+		release_console_sem();
+
+		rc = copy_to_user(up, &tmp, sizeof(struct vt_mode));
+		if (rc)
+			ret = -EFAULT;
+		break;
+	}
+
+	/*
+	 * Returns global vt state. Note that VT 0 is always open, since
+	 * it's an alias for the current VT, and people can't use it here.
+	 * We cannot return state for more than 16 VTs, since v_state is short.
+	 */
+	case VT_GETSTATE:
+	{
+		struct vt_stat __user *vtstat = up;
+		unsigned short state, mask;
+
+		if (put_user(fg_console + 1, &vtstat->v_active))
+			ret = -EFAULT;
+		else {
+			state = 1;	/* /dev/tty0 is always open */
+			for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
+							++i, mask <<= 1)
+				if (VT_IS_IN_USE(i))
+					state |= mask;
+			ret = put_user(state, &vtstat->v_state);
+		}
+		break;
+	}
+
+	/*
+	 * Returns the first available (non-opened) console.
+	 */
+	case VT_OPENQRY:
+		for (i = 0; i < MAX_NR_CONSOLES; ++i)
+			if (! VT_IS_IN_USE(i))
+				break;
+		uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
+		goto setint;		 
+
+	/*
+	 * ioctl(fd, VT_ACTIVATE, num) will cause us to switch to vt # num,
+	 * with num >= 1 (switches to vt 0, our console, are not allowed, just
+	 * to preserve sanity).
+	 */
+	case VT_ACTIVATE:
+		if (!perm)
+			goto eperm;
+		if (arg == 0 || arg > MAX_NR_CONSOLES)
+			ret =  -ENXIO;
+		else {
+			arg--;
+			acquire_console_sem();
+			ret = vc_allocate(arg);
+			release_console_sem();
+			if (ret)
+				break;
+			set_console(arg);
+		}
+		break;
+
+	case VT_SETACTIVATE:
+	{
+		struct vt_setactivate vsa;
+
+		if (!perm)
+			goto eperm;
+
+		if (copy_from_user(&vsa, (struct vt_setactivate __user *)arg,
+					sizeof(struct vt_setactivate))) {
+			ret = -EFAULT;
+			goto out;
+		}
+		if (vsa.console == 0 || vsa.console > MAX_NR_CONSOLES)
+			ret = -ENXIO;
+		else {
+			vsa.console--;
+			acquire_console_sem();
+			ret = vc_allocate(vsa.console);
+			if (ret == 0) {
+				struct vc_data *nvc;
+				/* This is safe providing we don't drop the
+				   console sem between vc_allocate and
+				   finishing referencing nvc */
+				nvc = vc_cons[vsa.console].d;
+				nvc->vt_mode = vsa.mode;
+				nvc->vt_mode.frsig = 0;
+				put_pid(nvc->vt_pid);
+				nvc->vt_pid = get_pid(task_pid(current));
+			}
+			release_console_sem();
+			if (ret)
+				break;
+			/* Commence switch and lock */
+			set_console(arg);
+		}
+	}
+
+	/*
+	 * wait until the specified VT has been activated
+	 */
+	case VT_WAITACTIVE:
+		if (!perm)
+			goto eperm;
+		if (arg == 0 || arg > MAX_NR_CONSOLES)
+			ret = -ENXIO;
+		else
+			ret = vt_waitactive(arg);
+		break;
+
+	/*
+	 * If a vt is under process control, the kernel will not switch to it
+	 * immediately, but postpone the operation until the process calls this
+	 * ioctl, allowing the switch to complete.
+	 *
+	 * According to the X sources this is the behavior:
+	 *	0:	pending switch-from not OK
+	 *	1:	pending switch-from OK
+	 *	2:	completed switch-to OK
+	 */
+	case VT_RELDISP:
+		if (!perm)
+			goto eperm;
+
+		if (vc->vt_mode.mode != VT_PROCESS) {
+			ret = -EINVAL;
+			break;
+		}
+		/*
+		 * Switching-from response
+		 */
+		acquire_console_sem();
+		if (vc->vt_newvt >= 0) {
+			if (arg == 0)
+				/*
+				 * Switch disallowed, so forget we were trying
+				 * to do it.
+				 */
+				vc->vt_newvt = -1;
+
+			else {
+				/*
+				 * The current vt has been released, so
+				 * complete the switch.
+				 */
+				int newvt;
+				newvt = vc->vt_newvt;
+				vc->vt_newvt = -1;
+				ret = vc_allocate(newvt);
+				if (ret) {
+					release_console_sem();
+					break;
+				}
+				/*
+				 * When we actually do the console switch,
+				 * make sure we are atomic with respect to
+				 * other console switches..
+				 */
+				complete_change_console(vc_cons[newvt].d);
+			}
+		} else {
+			/*
+			 * Switched-to response
+			 */
+			/*
+			 * If it's just an ACK, ignore it
+			 */
+			if (arg != VT_ACKACQ)
+				ret = -EINVAL;
+		}
+		release_console_sem();
+		break;
+
+	 /*
+	  * Disallocate memory associated to VT (but leave VT1)
+	  */
+	 case VT_DISALLOCATE:
+		if (arg > MAX_NR_CONSOLES) {
+			ret = -ENXIO;
+			break;
+		}
+		if (arg == 0) {
+		    /* deallocate all unused consoles, but leave 0 */
+			acquire_console_sem();
+			for (i=1; i<MAX_NR_CONSOLES; i++)
+				if (! VT_BUSY(i))
+					vc_deallocate(i);
+			release_console_sem();
+		} else {
+			/* deallocate a single console, if possible */
+			arg--;
+			if (VT_BUSY(arg))
+				ret = -EBUSY;
+			else if (arg) {			      /* leave 0 */
+				acquire_console_sem();
+				vc_deallocate(arg);
+				release_console_sem();
+			}
+		}
+		break;
+
+	case VT_RESIZE:
+	{
+		struct vt_sizes __user *vtsizes = up;
+		struct vc_data *vc;
+
+		ushort ll,cc;
+		if (!perm)
+			goto eperm;
+		if (get_user(ll, &vtsizes->v_rows) ||
+		    get_user(cc, &vtsizes->v_cols))
+			ret = -EFAULT;
+		else {
+			acquire_console_sem();
+			for (i = 0; i < MAX_NR_CONSOLES; i++) {
+				vc = vc_cons[i].d;
+
+				if (vc) {
+					vc->vc_resize_user = 1;
+					vc_resize(vc_cons[i].d, cc, ll);
+				}
+			}
+			release_console_sem();
+		}
+		break;
+	}
+
+	case VT_RESIZEX:
+	{
+		struct vt_consize __user *vtconsize = up;
+		ushort ll,cc,vlin,clin,vcol,ccol;
+		if (!perm)
+			goto eperm;
+		if (!access_ok(VERIFY_READ, vtconsize,
+				sizeof(struct vt_consize))) {
+			ret = -EFAULT;
+			break;
+		}
+		/* FIXME: Should check the copies properly */
+		__get_user(ll, &vtconsize->v_rows);
+		__get_user(cc, &vtconsize->v_cols);
+		__get_user(vlin, &vtconsize->v_vlin);
+		__get_user(clin, &vtconsize->v_clin);
+		__get_user(vcol, &vtconsize->v_vcol);
+		__get_user(ccol, &vtconsize->v_ccol);
+		vlin = vlin ? vlin : vc->vc_scan_lines;
+		if (clin) {
+			if (ll) {
+				if (ll != vlin/clin) {
+					/* Parameters don't add up */
+					ret = -EINVAL;
+					break;
+				}
+			} else 
+				ll = vlin/clin;
+		}
+		if (vcol && ccol) {
+			if (cc) {
+				if (cc != vcol/ccol) {
+					ret = -EINVAL;
+					break;
+				}
+			} else
+				cc = vcol/ccol;
+		}
+
+		if (clin > 32) {
+			ret =  -EINVAL;
+			break;
+		}
+		    
+		for (i = 0; i < MAX_NR_CONSOLES; i++) {
+			if (!vc_cons[i].d)
+				continue;
+			acquire_console_sem();
+			if (vlin)
+				vc_cons[i].d->vc_scan_lines = vlin;
+			if (clin)
+				vc_cons[i].d->vc_font.height = clin;
+			vc_cons[i].d->vc_resize_user = 1;
+			vc_resize(vc_cons[i].d, cc, ll);
+			release_console_sem();
+		}
+		break;
+	}
+
+	case PIO_FONT: {
+		if (!perm)
+			goto eperm;
+		op.op = KD_FONT_OP_SET;
+		op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC;	/* Compatibility */
+		op.width = 8;
+		op.height = 0;
+		op.charcount = 256;
+		op.data = up;
+		ret = con_font_op(vc_cons[fg_console].d, &op);
+		break;
+	}
+
+	case GIO_FONT: {
+		op.op = KD_FONT_OP_GET;
+		op.flags = KD_FONT_FLAG_OLD;
+		op.width = 8;
+		op.height = 32;
+		op.charcount = 256;
+		op.data = up;
+		ret = con_font_op(vc_cons[fg_console].d, &op);
+		break;
+	}
+
+	case PIO_CMAP:
+                if (!perm)
+			ret = -EPERM;
+		else
+	                ret = con_set_cmap(up);
+		break;
+
+	case GIO_CMAP:
+                ret = con_get_cmap(up);
+		break;
+
+	case PIO_FONTX:
+	case GIO_FONTX:
+		ret = do_fontx_ioctl(cmd, up, perm, &op);
+		break;
+
+	case PIO_FONTRESET:
+	{
+		if (!perm)
+			goto eperm;
+
+#ifdef BROKEN_GRAPHICS_PROGRAMS
+		/* With BROKEN_GRAPHICS_PROGRAMS defined, the default
+		   font is not saved. */
+		ret = -ENOSYS;
+		break;
+#else
+		{
+		op.op = KD_FONT_OP_SET_DEFAULT;
+		op.data = NULL;
+		ret = con_font_op(vc_cons[fg_console].d, &op);
+		if (ret)
+			break;
+		con_set_default_unimap(vc_cons[fg_console].d);
+		break;
+		}
+#endif
+	}
+
+	case KDFONTOP: {
+		if (copy_from_user(&op, up, sizeof(op))) {
+			ret = -EFAULT;
+			break;
+		}
+		if (!perm && op.op != KD_FONT_OP_GET)
+			goto eperm;
+		ret = con_font_op(vc, &op);
+		if (ret)
+			break;
+		if (copy_to_user(up, &op, sizeof(op)))
+			ret = -EFAULT;
+		break;
+	}
+
+	case PIO_SCRNMAP:
+		if (!perm)
+			ret = -EPERM;
+		else
+			ret = con_set_trans_old(up);
+		break;
+
+	case GIO_SCRNMAP:
+		ret = con_get_trans_old(up);
+		break;
+
+	case PIO_UNISCRNMAP:
+		if (!perm)
+			ret = -EPERM;
+		else
+			ret = con_set_trans_new(up);
+		break;
+
+	case GIO_UNISCRNMAP:
+		ret = con_get_trans_new(up);
+		break;
+
+	case PIO_UNIMAPCLR:
+	      { struct unimapinit ui;
+		if (!perm)
+			goto eperm;
+		ret = copy_from_user(&ui, up, sizeof(struct unimapinit));
+		if (ret)
+			ret = -EFAULT;
+		else
+			con_clear_unimap(vc, &ui);
+		break;
+	      }
+
+	case PIO_UNIMAP:
+	case GIO_UNIMAP:
+		ret = do_unimap_ioctl(cmd, up, perm, vc);
+		break;
+
+	case VT_LOCKSWITCH:
+		if (!capable(CAP_SYS_TTY_CONFIG))
+			goto eperm;
+		vt_dont_switch = 1;
+		break;
+	case VT_UNLOCKSWITCH:
+		if (!capable(CAP_SYS_TTY_CONFIG))
+			goto eperm;
+		vt_dont_switch = 0;
+		break;
+	case VT_GETHIFONTMASK:
+		ret = put_user(vc->vc_hi_font_mask,
+					(unsigned short __user *)arg);
+		break;
+	case VT_WAITEVENT:
+		ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
+		break;
+	default:
+		ret = -ENOIOCTLCMD;
+	}
+out:
+	tty_unlock();
+	return ret;
+eperm:
+	ret = -EPERM;
+	goto out;
+}
+
+void reset_vc(struct vc_data *vc)
+{
+	vc->vc_mode = KD_TEXT;
+	kbd_table[vc->vc_num].kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
+	vc->vt_mode.mode = VT_AUTO;
+	vc->vt_mode.waitv = 0;
+	vc->vt_mode.relsig = 0;
+	vc->vt_mode.acqsig = 0;
+	vc->vt_mode.frsig = 0;
+	put_pid(vc->vt_pid);
+	vc->vt_pid = NULL;
+	vc->vt_newvt = -1;
+	if (!in_interrupt())    /* Via keyboard.c:SAK() - akpm */
+		reset_palette(vc);
+}
+
+void vc_SAK(struct work_struct *work)
+{
+	struct vc *vc_con =
+		container_of(work, struct vc, SAK_work);
+	struct vc_data *vc;
+	struct tty_struct *tty;
+
+	acquire_console_sem();
+	vc = vc_con->d;
+	if (vc) {
+		tty = vc->port.tty;
+		/*
+		 * SAK should also work in all raw modes and reset
+		 * them properly.
+		 */
+		if (tty)
+			__do_SAK(tty);
+		reset_vc(vc);
+	}
+	release_console_sem();
+}
+
+#ifdef CONFIG_COMPAT
+
+struct compat_consolefontdesc {
+	unsigned short charcount;       /* characters in font (256 or 512) */
+	unsigned short charheight;      /* scan lines per character (1-32) */
+	compat_caddr_t chardata;	/* font data in expanded form */
+};
+
+static inline int
+compat_fontx_ioctl(int cmd, struct compat_consolefontdesc __user *user_cfd,
+			 int perm, struct console_font_op *op)
+{
+	struct compat_consolefontdesc cfdarg;
+	int i;
+
+	if (copy_from_user(&cfdarg, user_cfd, sizeof(struct compat_consolefontdesc)))
+		return -EFAULT;
+
+	switch (cmd) {
+	case PIO_FONTX:
+		if (!perm)
+			return -EPERM;
+		op->op = KD_FONT_OP_SET;
+		op->flags = KD_FONT_FLAG_OLD;
+		op->width = 8;
+		op->height = cfdarg.charheight;
+		op->charcount = cfdarg.charcount;
+		op->data = compat_ptr(cfdarg.chardata);
+		return con_font_op(vc_cons[fg_console].d, op);
+	case GIO_FONTX:
+		op->op = KD_FONT_OP_GET;
+		op->flags = KD_FONT_FLAG_OLD;
+		op->width = 8;
+		op->height = cfdarg.charheight;
+		op->charcount = cfdarg.charcount;
+		op->data = compat_ptr(cfdarg.chardata);
+		i = con_font_op(vc_cons[fg_console].d, op);
+		if (i)
+			return i;
+		cfdarg.charheight = op->height;
+		cfdarg.charcount = op->charcount;
+		if (copy_to_user(user_cfd, &cfdarg, sizeof(struct compat_consolefontdesc)))
+			return -EFAULT;
+		return 0;
+	}
+	return -EINVAL;
+}
+
+struct compat_console_font_op {
+	compat_uint_t op;        /* operation code KD_FONT_OP_* */
+	compat_uint_t flags;     /* KD_FONT_FLAG_* */
+	compat_uint_t width, height;     /* font size */
+	compat_uint_t charcount;
+	compat_caddr_t data;    /* font data with height fixed to 32 */
+};
+
+static inline int
+compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
+			 int perm, struct console_font_op *op, struct vc_data *vc)
+{
+	int i;
+
+	if (copy_from_user(op, fontop, sizeof(struct compat_console_font_op)))
+		return -EFAULT;
+	if (!perm && op->op != KD_FONT_OP_GET)
+		return -EPERM;
+	op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
+	op->flags |= KD_FONT_FLAG_OLD;
+	i = con_font_op(vc, op);
+	if (i)
+		return i;
+	((struct compat_console_font_op *)op)->data = (unsigned long)op->data;
+	if (copy_to_user(fontop, op, sizeof(struct compat_console_font_op)))
+		return -EFAULT;
+	return 0;
+}
+
+struct compat_unimapdesc {
+	unsigned short entry_ct;
+	compat_caddr_t entries;
+};
+
+static inline int
+compat_unimap_ioctl(unsigned int cmd, struct compat_unimapdesc __user *user_ud,
+			 int perm, struct vc_data *vc)
+{
+	struct compat_unimapdesc tmp;
+	struct unipair __user *tmp_entries;
+
+	if (copy_from_user(&tmp, user_ud, sizeof tmp))
+		return -EFAULT;
+	tmp_entries = compat_ptr(tmp.entries);
+	if (tmp_entries)
+		if (!access_ok(VERIFY_WRITE, tmp_entries,
+				tmp.entry_ct*sizeof(struct unipair)))
+			return -EFAULT;
+	switch (cmd) {
+	case PIO_UNIMAP:
+		if (!perm)
+			return -EPERM;
+		return con_set_unimap(vc, tmp.entry_ct, tmp_entries);
+	case GIO_UNIMAP:
+		if (!perm && fg_console != vc->vc_num)
+			return -EPERM;
+		return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct), tmp_entries);
+	}
+	return 0;
+}
+
+long vt_compat_ioctl(struct tty_struct *tty, struct file * file,
+	     unsigned int cmd, unsigned long arg)
+{
+	struct vc_data *vc = tty->driver_data;
+	struct console_font_op op;	/* used in multiple places here */
+	struct kbd_struct *kbd;
+	unsigned int console;
+	void __user *up = (void __user *)arg;
+	int perm;
+	int ret = 0;
+
+	console = vc->vc_num;
+
+	tty_lock();
+
+	if (!vc_cons_allocated(console)) { 	/* impossible? */
+		ret = -ENOIOCTLCMD;
+		goto out;
+	}
+
+	/*
+	 * To have permissions to do most of the vt ioctls, we either have
+	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
+	 */
+	perm = 0;
+	if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
+		perm = 1;
+
+	kbd = kbd_table + console;
+	switch (cmd) {
+	/*
+	 * these need special handlers for incompatible data structures
+	 */
+	case PIO_FONTX:
+	case GIO_FONTX:
+		ret = compat_fontx_ioctl(cmd, up, perm, &op);
+		break;
+
+	case KDFONTOP:
+		ret = compat_kdfontop_ioctl(up, perm, &op, vc);
+		break;
+
+	case PIO_UNIMAP:
+	case GIO_UNIMAP:
+		ret = compat_unimap_ioctl(cmd, up, perm, vc);
+		break;
+
+	/*
+	 * all these treat 'arg' as an integer
+	 */
+	case KIOCSOUND:
+	case KDMKTONE:
+#ifdef CONFIG_X86
+	case KDADDIO:
+	case KDDELIO:
+#endif
+	case KDSETMODE:
+	case KDMAPDISP:
+	case KDUNMAPDISP:
+	case KDSKBMODE:
+	case KDSKBMETA:
+	case KDSKBLED:
+	case KDSETLED:
+	case KDSIGACCEPT:
+	case VT_ACTIVATE:
+	case VT_WAITACTIVE:
+	case VT_RELDISP:
+	case VT_DISALLOCATE:
+	case VT_RESIZE:
+	case VT_RESIZEX:
+		goto fallback;
+
+	/*
+	 * the rest has a compatible data structure behind arg,
+	 * but we have to convert it to a proper 64 bit pointer.
+	 */
+	default:
+		arg = (unsigned long)compat_ptr(arg);
+		goto fallback;
+	}
+out:
+	tty_unlock();
+	return ret;
+
+fallback:
+	tty_unlock();
+	return vt_ioctl(tty, file, cmd, arg);
+}
+
+
+#endif /* CONFIG_COMPAT */
+
+
+/*
+ * Performs the back end of a vt switch. Called under the console
+ * semaphore.
+ */
+static void complete_change_console(struct vc_data *vc)
+{
+	unsigned char old_vc_mode;
+	int old = fg_console;
+
+	last_console = fg_console;
+
+	/*
+	 * If we're switching, we could be going from KD_GRAPHICS to
+	 * KD_TEXT mode or vice versa, which means we need to blank or
+	 * unblank the screen later.
+	 */
+	old_vc_mode = vc_cons[fg_console].d->vc_mode;
+	switch_screen(vc);
+
+	/*
+	 * This can't appear below a successful kill_pid().  If it did,
+	 * then the *blank_screen operation could occur while X, having
+	 * received acqsig, is waking up on another processor.  This
+	 * condition can lead to overlapping accesses to the VGA range
+	 * and the framebuffer (causing system lockups).
+	 *
+	 * To account for this we duplicate this code below only if the
+	 * controlling process is gone and we've called reset_vc.
+	 */
+	if (old_vc_mode != vc->vc_mode) {
+		if (vc->vc_mode == KD_TEXT)
+			do_unblank_screen(1);
+		else
+			do_blank_screen(1);
+	}
+
+	/*
+	 * If this new console is under process control, send it a signal
+	 * telling it that it has acquired. Also check if it has died and
+	 * clean up (similar to logic employed in change_console())
+	 */
+	if (vc->vt_mode.mode == VT_PROCESS) {
+		/*
+		 * Send the signal as privileged - kill_pid() will
+		 * tell us if the process has gone or something else
+		 * is awry
+		 */
+		if (kill_pid(vc->vt_pid, vc->vt_mode.acqsig, 1) != 0) {
+		/*
+		 * The controlling process has died, so we revert back to
+		 * normal operation. In this case, we'll also change back
+		 * to KD_TEXT mode. I'm not sure if this is strictly correct
+		 * but it saves the agony when the X server dies and the screen
+		 * remains blanked due to KD_GRAPHICS! It would be nice to do
+		 * this outside of VT_PROCESS but there is no single process
+		 * to account for and tracking tty count may be undesirable.
+		 */
+			reset_vc(vc);
+
+			if (old_vc_mode != vc->vc_mode) {
+				if (vc->vc_mode == KD_TEXT)
+					do_unblank_screen(1);
+				else
+					do_blank_screen(1);
+			}
+		}
+	}
+
+	/*
+	 * Wake anyone waiting for their VT to activate
+	 */
+	vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
+	return;
+}
+
+/*
+ * Performs the front-end of a vt switch
+ */
+void change_console(struct vc_data *new_vc)
+{
+	struct vc_data *vc;
+
+	if (!new_vc || new_vc->vc_num == fg_console || vt_dont_switch)
+		return;
+
+	/*
+	 * If this vt is in process mode, then we need to handshake with
+	 * that process before switching. Essentially, we store where that
+	 * vt wants to switch to and wait for it to tell us when it's done
+	 * (via VT_RELDISP ioctl).
+	 *
+	 * We also check to see if the controlling process still exists.
+	 * If it doesn't, we reset this vt to auto mode and continue.
+	 * This is a cheap way to track process control. The worst thing
+	 * that can happen is: we send a signal to a process, it dies, and
+	 * the switch gets "lost" waiting for a response; hopefully, the
+	 * user will try again, we'll detect the process is gone (unless
+	 * the user waits just the right amount of time :-) and revert the
+	 * vt to auto control.
+	 */
+	vc = vc_cons[fg_console].d;
+	if (vc->vt_mode.mode == VT_PROCESS) {
+		/*
+		 * Send the signal as privileged - kill_pid() will
+		 * tell us if the process has gone or something else
+		 * is awry.
+		 *
+		 * We need to set vt_newvt *before* sending the signal or we
+		 * have a race.
+		 */
+		vc->vt_newvt = new_vc->vc_num;
+		if (kill_pid(vc->vt_pid, vc->vt_mode.relsig, 1) == 0) {
+			/*
+			 * It worked. Mark the vt to switch to and
+			 * return. The process needs to send us a
+			 * VT_RELDISP ioctl to complete the switch.
+			 */
+			return;
+		}
+
+		/*
+		 * The controlling process has died, so we revert back to
+		 * normal operation. In this case, we'll also change back
+		 * to KD_TEXT mode. I'm not sure if this is strictly correct
+		 * but it saves the agony when the X server dies and the screen
+		 * remains blanked due to KD_GRAPHICS! It would be nice to do
+		 * this outside of VT_PROCESS but there is no single process
+		 * to account for and tracking tty count may be undesirable.
+		 */
+		reset_vc(vc);
+
+		/*
+		 * Fall through to normal (VT_AUTO) handling of the switch...
+		 */
+	}
+
+	/*
+	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
+	 */
+	if (vc->vc_mode == KD_GRAPHICS)
+		return;
+
+	complete_change_console(new_vc);
+}
+
+/* Perform a kernel triggered VT switch for suspend/resume */
+
+static int disable_vt_switch;
+
+int vt_move_to_console(unsigned int vt, int alloc)
+{
+	int prev;
+
+	acquire_console_sem();
+	/* Graphics mode - up to X */
+	if (disable_vt_switch) {
+		release_console_sem();
+		return 0;
+	}
+	prev = fg_console;
+
+	if (alloc && vc_allocate(vt)) {
+		/* we can't have a free VC for now. Too bad,
+		 * we don't want to mess the screen for now. */
+		release_console_sem();
+		return -ENOSPC;
+	}
+
+	if (set_console(vt)) {
+		/*
+		 * We're unable to switch to the SUSPEND_CONSOLE.
+		 * Let the calling function know so it can decide
+		 * what to do.
+		 */
+		release_console_sem();
+		return -EIO;
+	}
+	release_console_sem();
+	tty_lock();
+	if (vt_waitactive(vt + 1)) {
+		pr_debug("Suspend: Can't switch VCs.");
+		tty_unlock();
+		return -EINTR;
+	}
+	tty_unlock();
+	return prev;
+}
+
+/*
+ * Normally during a suspend, we allocate a new console and switch to it.
+ * When we resume, we switch back to the original console.  This switch
+ * can be slow, so on systems where the framebuffer can handle restoration
+ * of video registers anyways, there's little point in doing the console
+ * switch.  This function allows you to disable it by passing it '0'.
+ */
+void pm_set_vt_switch(int do_switch)
+{
+	acquire_console_sem();
+	disable_vt_switch = !do_switch;
+	release_console_sem();
+}
+EXPORT_SYMBOL(pm_set_vt_switch);