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Merge branch 'x86-mem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 

* 'x86-mem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-64, mem: Convert memmove() to assembly file and fix return value bug
This commit is contained in:
Linus Torvalds 2011-03-15 19:41:42 -07:00
parent 209b6c8fa7 9599ec0471
commit d5d42399bd
3 changed files with 198 additions and 192 deletions
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1
arch/x86/kernel/x8664_ksyms_64.c
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@ -52,6 +52,7 @@ extern void *__memcpy(void *, const void *, __kernel_size_t);
EXPORT_SYMBOL(memset);
EXPORT_SYMBOL(memcpy);
EXPORT_SYMBOL(__memcpy);
EXPORT_SYMBOL(memmove);
EXPORT_SYMBOL(empty_zero_page);
#ifndef CONFIG_PARAVIRT

197
arch/x86/lib/memmove_64.S Normal file
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@ -0,0 +1,197 @@
/*
* Normally compiler builtins are used, but sometimes the compiler calls out
* of line code. Based on asm-i386/string.h.
*
* This assembly file is re-written from memmove_64.c file.
* - Copyright 2011 Fenghua Yu <fenghua.yu@intel.com>
*/
#define _STRING_C
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#undef memmove
/*
* Implement memmove(). This can handle overlap between src and dst.
*
* Input:
* rdi: dest
* rsi: src
* rdx: count
*
* Output:
* rax: dest
*/
ENTRY(memmove)
CFI_STARTPROC
/* Handle more 32bytes in loop */
mov %rdi, %rax
cmp $0x20, %rdx
jb 1f
/* Decide forward/backward copy mode */
cmp %rdi, %rsi
jb 2f
/*
* movsq instruction have many startup latency
* so we handle small size by general register.
*/
cmp $680, %rdx
jb 3f
/*
* movsq instruction is only good for aligned case.
*/
cmpb %dil, %sil
je 4f
3:
sub $0x20, %rdx
/*
* We gobble 32byts forward in each loop.
*/
5:
sub $0x20, %rdx
movq 0*8(%rsi), %r11
movq 1*8(%rsi), %r10
movq 2*8(%rsi), %r9
movq 3*8(%rsi), %r8
leaq 4*8(%rsi), %rsi
movq %r11, 0*8(%rdi)
movq %r10, 1*8(%rdi)
movq %r9, 2*8(%rdi)
movq %r8, 3*8(%rdi)
leaq 4*8(%rdi), %rdi
jae 5b
addq $0x20, %rdx
jmp 1f
/*
* Handle data forward by movsq.
*/
.p2align 4
4:
movq %rdx, %rcx
movq -8(%rsi, %rdx), %r11
lea -8(%rdi, %rdx), %r10
shrq $3, %rcx
rep movsq
movq %r11, (%r10)
jmp 13f
/*
* Handle data backward by movsq.
*/
.p2align 4
7:
movq %rdx, %rcx
movq (%rsi), %r11
movq %rdi, %r10
leaq -8(%rsi, %rdx), %rsi
leaq -8(%rdi, %rdx), %rdi
shrq $3, %rcx
std
rep movsq
cld
movq %r11, (%r10)
jmp 13f
/*
* Start to prepare for backward copy.
*/
.p2align 4
2:
cmp $680, %rdx
jb 6f
cmp %dil, %sil
je 7b
6:
/*
* Calculate copy position to tail.
*/
addq %rdx, %rsi
addq %rdx, %rdi
subq $0x20, %rdx
/*
* We gobble 32byts backward in each loop.
*/
8:
subq $0x20, %rdx
movq -1*8(%rsi), %r11
movq -2*8(%rsi), %r10
movq -3*8(%rsi), %r9
movq -4*8(%rsi), %r8
leaq -4*8(%rsi), %rsi
movq %r11, -1*8(%rdi)
movq %r10, -2*8(%rdi)
movq %r9, -3*8(%rdi)
movq %r8, -4*8(%rdi)
leaq -4*8(%rdi), %rdi
jae 8b
/*
* Calculate copy position to head.
*/
addq $0x20, %rdx
subq %rdx, %rsi
subq %rdx, %rdi
1:
cmpq $16, %rdx
jb 9f
/*
* Move data from 16 bytes to 31 bytes.
*/
movq 0*8(%rsi), %r11
movq 1*8(%rsi), %r10
movq -2*8(%rsi, %rdx), %r9
movq -1*8(%rsi, %rdx), %r8
movq %r11, 0*8(%rdi)
movq %r10, 1*8(%rdi)
movq %r9, -2*8(%rdi, %rdx)
movq %r8, -1*8(%rdi, %rdx)
jmp 13f
.p2align 4
9:
cmpq $8, %rdx
jb 10f
/*
* Move data from 8 bytes to 15 bytes.
*/
movq 0*8(%rsi), %r11
movq -1*8(%rsi, %rdx), %r10
movq %r11, 0*8(%rdi)
movq %r10, -1*8(%rdi, %rdx)
jmp 13f
10:
cmpq $4, %rdx
jb 11f
/*
* Move data from 4 bytes to 7 bytes.
*/
movl (%rsi), %r11d
movl -4(%rsi, %rdx), %r10d
movl %r11d, (%rdi)
movl %r10d, -4(%rdi, %rdx)
jmp 13f
11:
cmp $2, %rdx
jb 12f
/*
* Move data from 2 bytes to 3 bytes.
*/
movw (%rsi), %r11w
movw -2(%rsi, %rdx), %r10w
movw %r11w, (%rdi)
movw %r10w, -2(%rdi, %rdx)
jmp 13f
12:
cmp $1, %rdx
jb 13f
/*
* Move data for 1 byte.
*/
movb (%rsi), %r11b
movb %r11b, (%rdi)
13:
retq
CFI_ENDPROC
ENDPROC(memmove)

192
arch/x86/lib/memmove_64.c
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@ -1,192 +0,0 @@
/* Normally compiler builtins are used, but sometimes the compiler calls out
of line code. Based on asm-i386/string.h.
*/
#define _STRING_C
#include <linux/string.h>
#include <linux/module.h>
#undef memmove
void *memmove(void *dest, const void *src, size_t count)
{
unsigned long d0,d1,d2,d3,d4,d5,d6,d7;
char *ret;
__asm__ __volatile__(
/* Handle more 32bytes in loop */
"mov %2, %3\n\t"
"cmp $0x20, %0\n\t"
"jb 1f\n\t"
/* Decide forward/backward copy mode */
"cmp %2, %1\n\t"
"jb 2f\n\t"
/*
* movsq instruction have many startup latency
* so we handle small size by general register.
*/
"cmp $680, %0\n\t"
"jb 3f\n\t"
/*
* movsq instruction is only good for aligned case.
*/
"cmpb %%dil, %%sil\n\t"
"je 4f\n\t"
"3:\n\t"
"sub $0x20, %0\n\t"
/*
* We gobble 32byts forward in each loop.
*/
"5:\n\t"
"sub $0x20, %0\n\t"
"movq 0*8(%1), %4\n\t"
"movq 1*8(%1), %5\n\t"
"movq 2*8(%1), %6\n\t"
"movq 3*8(%1), %7\n\t"
"leaq 4*8(%1), %1\n\t"
"movq %4, 0*8(%2)\n\t"
"movq %5, 1*8(%2)\n\t"
"movq %6, 2*8(%2)\n\t"
"movq %7, 3*8(%2)\n\t"
"leaq 4*8(%2), %2\n\t"
"jae 5b\n\t"
"addq $0x20, %0\n\t"
"jmp 1f\n\t"
/*
* Handle data forward by movsq.
*/
".p2align 4\n\t"
"4:\n\t"
"movq %0, %8\n\t"
"movq -8(%1, %0), %4\n\t"
"lea -8(%2, %0), %5\n\t"
"shrq $3, %8\n\t"
"rep movsq\n\t"
"movq %4, (%5)\n\t"
"jmp 13f\n\t"
/*
* Handle data backward by movsq.
*/
".p2align 4\n\t"
"7:\n\t"
"movq %0, %8\n\t"
"movq (%1), %4\n\t"
"movq %2, %5\n\t"
"leaq -8(%1, %0), %1\n\t"
"leaq -8(%2, %0), %2\n\t"
"shrq $3, %8\n\t"
"std\n\t"
"rep movsq\n\t"
"cld\n\t"
"movq %4, (%5)\n\t"
"jmp 13f\n\t"
/*
* Start to prepare for backward copy.
*/
".p2align 4\n\t"
"2:\n\t"
"cmp $680, %0\n\t"
"jb 6f \n\t"
"cmp %%dil, %%sil\n\t"
"je 7b \n\t"
"6:\n\t"
/*
* Calculate copy position to tail.
*/
"addq %0, %1\n\t"
"addq %0, %2\n\t"
"subq $0x20, %0\n\t"
/*
* We gobble 32byts backward in each loop.
*/
"8:\n\t"
"subq $0x20, %0\n\t"
"movq -1*8(%1), %4\n\t"
"movq -2*8(%1), %5\n\t"
"movq -3*8(%1), %6\n\t"
"movq -4*8(%1), %7\n\t"
"leaq -4*8(%1), %1\n\t"
"movq %4, -1*8(%2)\n\t"
"movq %5, -2*8(%2)\n\t"
"movq %6, -3*8(%2)\n\t"
"movq %7, -4*8(%2)\n\t"
"leaq -4*8(%2), %2\n\t"
"jae 8b\n\t"
/*
* Calculate copy position to head.
*/
"addq $0x20, %0\n\t"
"subq %0, %1\n\t"
"subq %0, %2\n\t"
"1:\n\t"
"cmpq $16, %0\n\t"
"jb 9f\n\t"
/*
* Move data from 16 bytes to 31 bytes.
*/
"movq 0*8(%1), %4\n\t"
"movq 1*8(%1), %5\n\t"
"movq -2*8(%1, %0), %6\n\t"
"movq -1*8(%1, %0), %7\n\t"
"movq %4, 0*8(%2)\n\t"
"movq %5, 1*8(%2)\n\t"
"movq %6, -2*8(%2, %0)\n\t"
"movq %7, -1*8(%2, %0)\n\t"
"jmp 13f\n\t"
".p2align 4\n\t"
"9:\n\t"
"cmpq $8, %0\n\t"
"jb 10f\n\t"
/*
* Move data from 8 bytes to 15 bytes.
*/
"movq 0*8(%1), %4\n\t"
"movq -1*8(%1, %0), %5\n\t"
"movq %4, 0*8(%2)\n\t"
"movq %5, -1*8(%2, %0)\n\t"
"jmp 13f\n\t"
"10:\n\t"
"cmpq $4, %0\n\t"
"jb 11f\n\t"
/*
* Move data from 4 bytes to 7 bytes.
*/
"movl (%1), %4d\n\t"
"movl -4(%1, %0), %5d\n\t"
"movl %4d, (%2)\n\t"
"movl %5d, -4(%2, %0)\n\t"
"jmp 13f\n\t"
"11:\n\t"
"cmp $2, %0\n\t"
"jb 12f\n\t"
/*
* Move data from 2 bytes to 3 bytes.
*/
"movw (%1), %4w\n\t"
"movw -2(%1, %0), %5w\n\t"
"movw %4w, (%2)\n\t"
"movw %5w, -2(%2, %0)\n\t"
"jmp 13f\n\t"
"12:\n\t"
"cmp $1, %0\n\t"
"jb 13f\n\t"
/*
* Move data for 1 byte.
*/
"movb (%1), %4b\n\t"
"movb %4b, (%2)\n\t"
"13:\n\t"
: "=&d" (d0), "=&S" (d1), "=&D" (d2), "=&a" (ret) ,
"=r"(d3), "=r"(d4), "=r"(d5), "=r"(d6), "=&c" (d7)
:"0" (count),
"1" (src),
"2" (dest)
:"memory");
return ret;
}
EXPORT_SYMBOL(memmove);