1 files changed, 66 insertions, 2 deletions

diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index 58390c7..f15c898 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -100,16 +100,78 @@
  *	seek to perform this action quickly but should wait until
  *	any pending driver I/O is completed.
  *
+ * void (*fasync)(struct tty_struct *, int on)
+ *
+ *	Notify line discipline when signal-driven I/O is enabled or
+ *	disabled.
+ *
  * void (*dcd_change)(struct tty_struct *tty, unsigned int status)
  *
  *	Tells the discipline that the DCD pin has changed its status.
  *	Used exclusively by the N_PPS (Pulse-Per-Second) line discipline.
+ *
+ * int	(*receive_buf2)(struct tty_struct *, const unsigned char *cp,
+ *			char *fp, int count);
+ *
+ *	This function is called by the low-level tty driver to send
+ *	characters received by the hardware to the line discpline for
+ *	processing.  <cp> is a pointer to the buffer of input
+ *	character received by the device.  <fp> is a pointer to a
+ *	pointer of flag bytes which indicate whether a character was
+ *	received with a parity error, etc.
+ *	If assigned, prefer this function for automatic flow control.
  */
 
 #include <linux/fs.h>
 #include <linux/wait.h>
 #include <linux/wait.h>
 
+
+/*
+ * the semaphore definition
+ */
+struct ld_semaphore {
+	long			count;
+	raw_spinlock_t		wait_lock;
+	unsigned int		wait_readers;
+	struct list_head	read_wait;
+	struct list_head	write_wait;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
+};
+
+extern void __init_ldsem(struct ld_semaphore *sem, const char *name,
+			 struct lock_class_key *key);
+
+#define init_ldsem(sem)						\
+do {								\
+	static struct lock_class_key __key;			\
+								\
+	__init_ldsem((sem), #sem, &__key);			\
+} while (0)
+
+
+extern int ldsem_down_read(struct ld_semaphore *sem, long timeout);
+extern int ldsem_down_read_trylock(struct ld_semaphore *sem);
+extern int ldsem_down_write(struct ld_semaphore *sem, long timeout);
+extern int ldsem_down_write_trylock(struct ld_semaphore *sem);
+extern void ldsem_up_read(struct ld_semaphore *sem);
+extern void ldsem_up_write(struct ld_semaphore *sem);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+extern int ldsem_down_read_nested(struct ld_semaphore *sem, int subclass,
+				  long timeout);
+extern int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
+				   long timeout);
+#else
+# define ldsem_down_read_nested(sem, subclass, timeout)		\
+		ldsem_down_read(sem, timeout)
+# define ldsem_down_write_nested(sem, subclass, timeout)	\
+		ldsem_down_write(sem, timeout)
+#endif
+
+
 struct tty_ldisc_ops {
 	int	magic;
 	char	*name;
@@ -143,6 +205,9 @@ struct tty_ldisc_ops {
 			       char *fp, int count);
 	void	(*write_wakeup)(struct tty_struct *);
 	void	(*dcd_change)(struct tty_struct *, unsigned int);
+	void	(*fasync)(struct tty_struct *tty, int on);
+	int	(*receive_buf2)(struct tty_struct *, const unsigned char *cp,
+				char *fp, int count);
 
 	struct  module *owner;
 
@@ -151,8 +216,7 @@ struct tty_ldisc_ops {
 
 struct tty_ldisc {
 	struct tty_ldisc_ops *ops;
-	atomic_t users;
-	wait_queue_head_t wq_idle;
+	struct tty_struct *tty;
 };
 
 #define TTY_LDISC_MAGIC	0x5403