diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
---|---|---|
committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/tile/lib/strchr_32.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/tile/lib/strchr_32.c')
-rw-r--r-- | kernel/arch/tile/lib/strchr_32.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/kernel/arch/tile/lib/strchr_32.c b/kernel/arch/tile/lib/strchr_32.c new file mode 100644 index 000000000..841fe6963 --- /dev/null +++ b/kernel/arch/tile/lib/strchr_32.c @@ -0,0 +1,64 @@ +/* + * Copyright 2010 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> + +char *strchr(const char *s, int c) +{ + int z, g; + + /* Get an aligned pointer. */ + const uintptr_t s_int = (uintptr_t) s; + const uint32_t *p = (const uint32_t *)(s_int & -4); + + /* Create four copies of the byte for which we are looking. */ + const uint32_t goal = 0x01010101 * (uint8_t) c; + + /* Read the first aligned word, but force bytes before the string to + * match neither zero nor goal (we make sure the high bit of each + * byte is 1, and the low 7 bits are all the opposite of the goal + * byte). + * + * Note that this shift count expression works because we know shift + * counts are taken mod 32. + */ + const uint32_t before_mask = (1 << (s_int << 3)) - 1; + uint32_t v = (*p | before_mask) ^ (goal & __insn_shrib(before_mask, 1)); + + uint32_t zero_matches, goal_matches; + while (1) { + /* Look for a terminating '\0'. */ + zero_matches = __insn_seqb(v, 0); + + /* Look for the goal byte. */ + goal_matches = __insn_seqb(v, goal); + + if (__builtin_expect(zero_matches | goal_matches, 0)) + break; + + v = *++p; + } + + z = __insn_ctz(zero_matches); + g = __insn_ctz(goal_matches); + + /* If we found c before '\0' we got a match. Note that if c == '\0' + * then g == z, and we correctly return the address of the '\0' + * rather than NULL. + */ + return (g <= z) ? ((char *)p) + (g >> 3) : NULL; +} +EXPORT_SYMBOL(strchr); |