arch/tile: finish enabling support for TILE-Gx 64-bit chip

This support was partially present in the existing code (look for
"__tilegx__" ifdefs) but with this change you can build a working
kernel using the TILE-Gx toolchain and ARCH=tilegx.

Most of these files are new, generally adding a foo_64.c file
where previously there was just a foo_32.c file.

The ARCH=tilegx directive redirects to arch/tile, not arch/tilegx,
using the existing SRCARCH mechanism in the top-level Makefile.

Changes to existing files:

- <asm/bitops.h> and <asm/bitops_32.h> changed to factor the
  include of <asm-generic/bitops/non-atomic.h> in the common header.

- <asm/compat.h> and arch/tile/kernel/compat.c changed to remove
  the "const" markers I had put on compat_sys_execve() when trying
  to match some recent similar changes to the non-compat execve.
  It turns out the compat version wasn't "upgraded" to use const.

- <asm/opcode-tile_64.h> and <asm/opcode_constants_64.h> were
  previously included accidentally, with the 32-bit contents.  Now
  they have the proper 64-bit contents.

Finally, I had to hack the existing hacky drivers/input/input-compat.h
to add yet another "#ifdef" for INPUT_COMPAT_TEST (same as x86_64).

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> [drivers/input]

1 files changed, 71 insertions, 0 deletions

diff --git a/arch/tile/lib/memchr_64.c b/arch/tile/lib/memchr_64.c
new file mode 100644
index 000000000000..84fdc8d8e735
--- /dev/null
+++ b/arch/tile/lib/memchr_64.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2011 Tilera Corporation. 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
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   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, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+
+void *memchr(const void *s, int c, size_t n)
+{
+	const uint64_t *last_word_ptr;
+	const uint64_t *p;
+	const char *last_byte_ptr;
+	uintptr_t s_int;
+	uint64_t goal, before_mask, v, bits;
+	char *ret;
+
+	if (__builtin_expect(n == 0, 0)) {
+		/* Don't dereference any memory if the array is empty. */
+		return NULL;
+	}
+
+	/* Get an aligned pointer. */
+	s_int = (uintptr_t) s;
+	p = (const uint64_t *)(s_int & -8);
+
+	/* Create eight copies of the byte for which we are looking. */
+	goal = 0x0101010101010101ULL * (uint8_t) c;
+
+	/* Read the first word, but munge it so that bytes before the array
+	 * will not match goal.
+	 *
+	 * Note that this shift count expression works because we know
+	 * shift counts are taken mod 64.
+	 */
+	before_mask = (1ULL << (s_int << 3)) - 1;
+	v = (*p | before_mask) ^ (goal & before_mask);
+
+	/* Compute the address of the last byte. */
+	last_byte_ptr = (const char *)s + n - 1;
+
+	/* Compute the address of the word containing the last byte. */
+	last_word_ptr = (const uint64_t *)((uintptr_t) last_byte_ptr & -8);
+
+	while ((bits = __insn_v1cmpeq(v, goal)) == 0) {
+		if (__builtin_expect(p == last_word_ptr, 0)) {
+			/* We already read the last word in the array,
+			 * so give up.
+			 */
+			return NULL;
+		}
+		v = *++p;
+	}
+
+	/* We found a match, but it might be in a byte past the end
+	 * of the array.
+	 */
+	ret = ((char *)p) + (__insn_ctz(bits) >> 3);
+	return (ret <= last_byte_ptr) ? ret : NULL;
+}
+EXPORT_SYMBOL(memchr);