linux/arch/tile/lib/strlen_64.c
Chris Metcalf 18aecc2b64 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]
2011-05-12 15:52:12 -04:00

39 lines
1.1 KiB
C

/*
* 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>
#undef strlen
size_t strlen(const char *s)
{
/* Get an aligned pointer. */
const uintptr_t s_int = (uintptr_t) s;
const uint64_t *p = (const uint64_t *)(s_int & -8);
/* Read the first word, but force bytes before the string to be nonzero.
* This expression works because we know shift counts are taken mod 64.
*/
uint64_t v = *p | ((1ULL << (s_int << 3)) - 1);
uint64_t bits;
while ((bits = __insn_v1cmpeqi(v, 0)) == 0)
v = *++p;
return ((const char *)p) + (__insn_ctz(bits) >> 3) - s;
}
EXPORT_SYMBOL(strlen);