Merge Qualcom Hexagon architecture

This is the fifth version of the patchset (with one tiny whitespace fix)
to the Linux kernel to support the Qualcomm Hexagon architecture.

Between now and the next pull requests, Richard Kuo should have his key
signed, etc., and should be back on kernel.org.  In the meantime, this
got merged as a emailed patch-series.

* Hexagon: (36 commits)
  Add extra arch overrides to asm-generic/checksum.h
  Hexagon: Add self to MAINTAINERS
  Hexagon: Add basic stacktrace functionality for Hexagon architecture.
  Hexagon: Add configuration and makefiles for the Hexagon architecture.
  Hexagon: Comet platform support
  Hexagon: kgdb support files
  Hexagon: Add page-fault support.
  Hexagon: Add page table header files & etc.
  Hexagon: Add ioremap support
  Hexagon: Provide DMA implementation
  Hexagon: Implement basic TLB management routines for Hexagon.
  Hexagon: Implement basic cache-flush support
  Hexagon: Provide basic implementation and/or stubs for I/O routines.
  Hexagon: Add user access functions
  Hexagon: Add locking types and functions
  Hexagon: Add SMP support
  Hexagon: Provide basic debugging and system trap support.
  Hexagon: Add ptrace support
  Hexagon: Add time and timer functions
  Hexagon: Add interrupts
  ...

1 files changed, 203 insertions, 0 deletions

diff --git a/arch/hexagon/lib/checksum.c b/arch/hexagon/lib/checksum.c
new file mode 100644
index 0000000..9300552
--- /dev/null
+++ b/arch/hexagon/lib/checksum.c
@@ -0,0 +1,203 @@
+/*
+ * Checksum functions for Hexagon
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/*  This was derived from arch/alpha/lib/checksum.c  */
+
+
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include <asm/byteorder.h>
+#include <net/checksum.h>
+#include <linux/uaccess.h>
+#include <asm/intrinsics.h>
+
+
+/*  Vector value operations  */
+#define SIGN(x, y)	((0x8000ULL*x)<<y)
+#define CARRY(x, y)	((0x0002ULL*x)<<y)
+#define SELECT(x, y)	((0x0001ULL*x)<<y)
+
+#define VR_NEGATE(a, b, c, d)	(SIGN(a, 48) + SIGN(b, 32) + SIGN(c, 16) \
+	+ SIGN(d, 0))
+#define VR_CARRY(a, b, c, d)	(CARRY(a, 48) + CARRY(b, 32) + CARRY(c, 16) \
+	+ CARRY(d, 0))
+#define VR_SELECT(a, b, c, d)	(SELECT(a, 48) + SELECT(b, 32) + SELECT(c, 16) \
+	+ SELECT(d, 0))
+
+
+/* optimized HEXAGON V3 intrinsic version */
+static inline unsigned short from64to16(u64 x)
+{
+	u64 sum;
+
+	sum = HEXAGON_P_vrmpyh_PP(x^VR_NEGATE(1, 1, 1, 1),
+			     VR_SELECT(1, 1, 1, 1));
+	sum += VR_CARRY(0, 0, 1, 0);
+	sum = HEXAGON_P_vrmpyh_PP(sum, VR_SELECT(0, 0, 1, 1));
+
+	return 0xFFFF & sum;
+}
+
+/*
+ * computes the checksum of the TCP/UDP pseudo-header
+ * returns a 16-bit checksum, already complemented.
+ */
+__sum16 csum_tcpudp_magic(unsigned long saddr, unsigned long daddr,
+			  unsigned short len, unsigned short proto,
+			  __wsum sum)
+{
+	return (__force __sum16)~from64to16(
+		(__force u64)saddr + (__force u64)daddr +
+		(__force u64)sum + ((len + proto) << 8));
+}
+
+__wsum csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr,
+			  unsigned short len, unsigned short proto,
+			  __wsum sum)
+{
+	u64 result;
+
+	result = (__force u64)saddr + (__force u64)daddr +
+		 (__force u64)sum + ((len + proto) << 8);
+
+	/* Fold down to 32-bits so we don't lose in the typedef-less
+	   network stack.  */
+	/* 64 to 33 */
+	result = (result & 0xffffffffUL) + (result >> 32);
+	/* 33 to 32 */
+	result = (result & 0xffffffffUL) + (result >> 32);
+	return (__force __wsum)result;
+}
+EXPORT_SYMBOL(csum_tcpudp_nofold);
+
+/*
+ * Do a 64-bit checksum on an arbitrary memory area..
+ *
+ * This isn't a great routine, but it's not _horrible_ either. The
+ * inner loop could be unrolled a bit further, and there are better
+ * ways to do the carry, but this is reasonable.
+ */
+
+/* optimized HEXAGON intrinsic version, with over read fixed */
+unsigned int do_csum(const void *voidptr, int len)
+{
+	u64 sum0, sum1, x0, x1, *ptr8_o, *ptr8_e, *ptr8;
+	int i, start, mid, end, mask;
+	const char *ptr = voidptr;
+	unsigned short *ptr2;
+	unsigned int *ptr4;
+
+	if (len <= 0)
+		return 0;
+
+	start = 0xF & (16-(((int) ptr) & 0xF)) ;
+	mask  = 0x7fffffffUL >> HEXAGON_R_cl0_R(len);
+	start = start & mask ;
+
+	mid = len - start;
+	end = mid & 0xF;
+	mid = mid>>4;
+	sum0 = mid << 18;
+	sum1 = 0;
+
+	if (start & 1)
+		sum0 += (u64) (ptr[0] << 8);
+	ptr2 = (unsigned short *) &ptr[start & 1];
+	if (start & 2)
+		sum1 += (u64) ptr2[0];
+	ptr4 = (unsigned int *) &ptr[start & 3];
+	if (start & 4) {
+		sum0 = HEXAGON_P_vrmpyhacc_PP(sum0,
+			VR_NEGATE(0, 0, 1, 1)^((u64)ptr4[0]),
+			VR_SELECT(0, 0, 1, 1));
+		sum0 += VR_SELECT(0, 0, 1, 0);
+	}
+	ptr8 = (u64 *) &ptr[start & 7];
+	if (start & 8) {
+		sum1 = HEXAGON_P_vrmpyhacc_PP(sum1,
+			VR_NEGATE(1, 1, 1, 1)^(ptr8[0]),
+			VR_SELECT(1, 1, 1, 1));
+		sum1 += VR_CARRY(0, 0, 1, 0);
+	}
+	ptr8_o = (u64 *) (ptr + start);
+	ptr8_e = (u64 *) (ptr + start + 8);
+
+	if (mid) {
+		x0 = *ptr8_e; ptr8_e += 2;
+		x1 = *ptr8_o; ptr8_o += 2;
+		if (mid > 1)
+			for (i = 0; i < mid-1; i++) {
+				sum0 = HEXAGON_P_vrmpyhacc_PP(sum0,
+					x0^VR_NEGATE(1, 1, 1, 1),
+					VR_SELECT(1, 1, 1, 1));
+				sum1 = HEXAGON_P_vrmpyhacc_PP(sum1,
+					x1^VR_NEGATE(1, 1, 1, 1),
+					VR_SELECT(1, 1, 1, 1));
+				x0 = *ptr8_e; ptr8_e += 2;
+				x1 = *ptr8_o; ptr8_o += 2;
+			}
+		sum0 = HEXAGON_P_vrmpyhacc_PP(sum0, x0^VR_NEGATE(1, 1, 1, 1),
+			VR_SELECT(1, 1, 1, 1));
+		sum1 = HEXAGON_P_vrmpyhacc_PP(sum1, x1^VR_NEGATE(1, 1, 1, 1),
+			VR_SELECT(1, 1, 1, 1));
+	}
+
+	ptr4 = (unsigned int *) &ptr[start + (mid * 16) + (end & 8)];
+	if (end & 4) {
+		sum1 = HEXAGON_P_vrmpyhacc_PP(sum1,
+			VR_NEGATE(0, 0, 1, 1)^((u64)ptr4[0]),
+			VR_SELECT(0, 0, 1, 1));
+		sum1 += VR_SELECT(0, 0, 1, 0);
+	}
+	ptr2 = (unsigned short *) &ptr[start + (mid * 16) + (end & 12)];
+	if (end & 2)
+		sum0 += (u64) ptr2[0];
+
+	if (end & 1)
+		sum1 += (u64) ptr[start + (mid * 16) + (end & 14)];
+
+	ptr8 = (u64 *) &ptr[start + (mid * 16)];
+	if (end & 8) {
+		sum0 = HEXAGON_P_vrmpyhacc_PP(sum0,
+			VR_NEGATE(1, 1, 1, 1)^(ptr8[0]),
+			VR_SELECT(1, 1, 1, 1));
+		sum0 += VR_CARRY(0, 0, 1, 0);
+	}
+	sum0 = HEXAGON_P_vrmpyh_PP((sum0+sum1)^VR_NEGATE(0, 0, 0, 1),
+		VR_SELECT(0, 0, 1, 1));
+	sum0 += VR_NEGATE(0, 0, 0, 1);
+	sum0 = HEXAGON_P_vrmpyh_PP(sum0, VR_SELECT(0, 0, 1, 1));
+
+	if (start & 1)
+		sum0 = (sum0 << 8) | (0xFF & (sum0 >> 8));
+
+	return 0xFFFF & sum0;
+}
+
+/*
+ * copy from ds while checksumming, otherwise like csum_partial
+ */
+__wsum
+csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
+{
+	memcpy(dst, src, len);
+	return csum_partial(dst, len, sum);
+}