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/memchr_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/memchr_32.c')
-rw-r--r-- | kernel/arch/tile/lib/memchr_32.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/kernel/arch/tile/lib/memchr_32.c b/kernel/arch/tile/lib/memchr_32.c new file mode 100644 index 000000000..cc3d9badf --- /dev/null +++ b/kernel/arch/tile/lib/memchr_32.c @@ -0,0 +1,71 @@ +/* + * 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> + +void *memchr(const void *s, int c, size_t n) +{ + const uint32_t *last_word_ptr; + const uint32_t *p; + const char *last_byte_ptr; + uintptr_t s_int; + uint32_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 uint32_t *)(s_int & -4); + + /* Create four copies of the byte for which we are looking. */ + goal = 0x01010101 * (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 32. + */ + before_mask = (1 << (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 uint32_t *)((uintptr_t) last_byte_ptr & -4); + + while ((bits = __insn_seqb(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); |