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Copy pathcopy_user_nocache_64.S
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copy_user_nocache_64.S
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/*
* Copyright 2008 Vitaly Mayatskikh <[email protected]>
* Copyright 2002 Andi Kleen, SuSE Labs.
* Subject to the GNU Public License v2.
*
* Functions to copy from and to user space.
*/
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#define FIX_ALIGNMENT 1
#include <asm/current.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
.macro ALIGN_DESTINATION
#ifdef FIX_ALIGNMENT
/* check for bad alignment of destination */
movl %edi,%ecx
andl $7,%ecx
jz 102f /* already aligned */
subl $8,%ecx
negl %ecx
subl %ecx,%edx
100: movb (%rsi),%al
101: movb %al,(%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz 100b
102:
.section .fixup,"ax"
103: addl %ecx,%edx /* ecx is zerorest also */
jmp copy_user_handle_tail
.previous
.section __ex_table,"a"
.align 8
.quad 100b,103b
.quad 101b,103b
.previous
#endif
.endm
/*
* copy_user_nocache - Uncached memory copy with exception handling
* This will force destination/source out of cache for more performance.
*/
ENTRY(__copy_user_nocache)
CFI_STARTPROC
cmpl $8,%edx
jb 20f /* less then 8 bytes, go to byte copy loop */
ALIGN_DESTINATION
movl %edx,%ecx
andl $63,%edx
shrl $6,%ecx
jz 17f
1: movq (%rsi),%r8
2: movq 1*8(%rsi),%r9
3: movq 2*8(%rsi),%r10
4: movq 3*8(%rsi),%r11
5: movnti %r8,(%rdi)
6: movnti %r9,1*8(%rdi)
7: movnti %r10,2*8(%rdi)
8: movnti %r11,3*8(%rdi)
9: movq 4*8(%rsi),%r8
10: movq 5*8(%rsi),%r9
11: movq 6*8(%rsi),%r10
12: movq 7*8(%rsi),%r11
13: movnti %r8,4*8(%rdi)
14: movnti %r9,5*8(%rdi)
15: movnti %r10,6*8(%rdi)
16: movnti %r11,7*8(%rdi)
leaq 64(%rsi),%rsi
leaq 64(%rdi),%rdi
decl %ecx
jnz 1b
17: movl %edx,%ecx
andl $7,%edx
shrl $3,%ecx
jz 20f
18: movq (%rsi),%r8
19: movnti %r8,(%rdi)
leaq 8(%rsi),%rsi
leaq 8(%rdi),%rdi
decl %ecx
jnz 18b
20: andl %edx,%edx
jz 23f
movl %edx,%ecx
21: movb (%rsi),%al
22: movb %al,(%rdi)
incq %rsi
incq %rdi
decl %ecx
jnz 21b
23: xorl %eax,%eax
sfence
ret
.section .fixup,"ax"
30: shll $6,%ecx
addl %ecx,%edx
jmp 60f
40: lea (%rdx,%rcx,8),%rdx
jmp 60f
50: movl %ecx,%edx
60: sfence
jmp copy_user_handle_tail
.previous
.section __ex_table,"a"
.quad 1b,30b
.quad 2b,30b
.quad 3b,30b
.quad 4b,30b
.quad 5b,30b
.quad 6b,30b
.quad 7b,30b
.quad 8b,30b
.quad 9b,30b
.quad 10b,30b
.quad 11b,30b
.quad 12b,30b
.quad 13b,30b
.quad 14b,30b
.quad 15b,30b
.quad 16b,30b
.quad 18b,40b
.quad 19b,40b
.quad 21b,50b
.quad 22b,50b
.previous
CFI_ENDPROC
ENDPROC(__copy_user_nocache)