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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-26 17:25:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-26 17:25:38 -0700
commite404f91ed2180dfecbab15dd4d39c543353385fb (patch)
treec256e29b1c738d5e5b5478f19b369b1fd90bd1e2 /arch/tile/lib/memmove.c
parent18a043f9413277523cf5011e594caa1747db4948 (diff)
parente18105c128734b1671739ad4d85e216ebec28c61 (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.c63
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);