diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-26 17:25:38 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-26 17:25:38 -0700 |
commit | e404f91ed2180dfecbab15dd4d39c543353385fb (patch) | |
tree | c256e29b1c738d5e5b5478f19b369b1fd90bd1e2 /arch/tile/lib/memmove.c | |
parent | 18a043f9413277523cf5011e594caa1747db4948 (diff) | |
parent | e18105c128734b1671739ad4d85e216ebec28c61 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/tile: convert a BUG_ON to BUILD_BUG_ON
arch/tile: make ptrace() work properly for TILE-Gx COMPAT mode
arch/tile: support new info op generated by compiler
arch/tile: minor whitespace/naming changes for string support files
arch/tile: enable single-step support for TILE-Gx
arch/tile: parameterize system PLs to support KVM port
arch/tile: add Tilera's <arch/sim.h> header as an open-source header
arch/tile: Bomb C99 comments to C89 comments in tile's <arch/sim_def.h>
arch/tile: prevent corrupt top frame from causing backtracer runaway
arch/tile: various top-level Makefile cleanups
arch/tile: change lower bound on syscall error return to -4095
arch/tile: properly export __mb_incoherent for modules
arch/tile: provide a definition of MAP_STACK
kmemleak: add TILE to the list of supported architectures.
char: hvc: check for error case
arch/tile: Add a warning if we try to allocate too much vmalloc memory.
arch/tile: update some comments to clarify register usage.
arch/tile: use better "punctuation" for VMSPLIT_3_5G and friends
arch/tile: Use <asm-generic/syscalls.h>
tile: replace some BUG_ON checks with BUILD_BUG_ON checks
Diffstat (limited to 'arch/tile/lib/memmove.c')
-rw-r--r-- | arch/tile/lib/memmove.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/tile/lib/memmove.c b/arch/tile/lib/memmove.c new file mode 100644 index 000000000000..fd615ae6ade7 --- /dev/null +++ b/arch/tile/lib/memmove.c @@ -0,0 +1,63 @@ +/* + * 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 *memmove(void *dest, const void *src, size_t n) +{ + if ((const char *)src >= (char *)dest + n + || (char *)dest >= (const char *)src + n) { + /* We found no overlap, so let memcpy do all the heavy + * lifting (prefetching, etc.) + */ + return memcpy(dest, src, n); + } + + if (n != 0) { + const uint8_t *in; + uint8_t x; + uint8_t *out; + int stride; + + if (src < dest) { + /* copy backwards */ + in = (const uint8_t *)src + n - 1; + out = (uint8_t *)dest + n - 1; + stride = -1; + } else { + /* copy forwards */ + in = (const uint8_t *)src; + out = (uint8_t *)dest; + stride = 1; + } + + /* Manually software-pipeline this loop. */ + x = *in; + in += stride; + + while (--n != 0) { + *out = x; + out += stride; + x = *in; + in += stride; + } + + *out = x; + } + + return dest; +} +EXPORT_SYMBOL(memmove); |