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-rw-r--r--arch/x86_64/lib/copy_page.S53
1 files changed, 36 insertions, 17 deletions
diff --git a/arch/x86_64/lib/copy_page.S b/arch/x86_64/lib/copy_page.S
index 8fa19d96a7ee..0ebb03b60e79 100644
--- a/arch/x86_64/lib/copy_page.S
+++ b/arch/x86_64/lib/copy_page.S
@@ -1,17 +1,33 @@
1/* Written 2003 by Andi Kleen, based on a kernel by Evandro Menezes */ 1/* Written 2003 by Andi Kleen, based on a kernel by Evandro Menezes */
2 2
3#include <linux/config.h>
4#include <linux/linkage.h>
5#include <asm/dwarf2.h>
6
7 ALIGN
8copy_page_c:
9 CFI_STARTPROC
10 movl $4096/8,%ecx
11 rep movsq
12 ret
13 CFI_ENDPROC
14ENDPROC(copy_page_c)
15
3/* Don't use streaming store because it's better when the target 16/* Don't use streaming store because it's better when the target
4 ends up in cache. */ 17 ends up in cache. */
5 18
6/* Could vary the prefetch distance based on SMP/UP */ 19/* Could vary the prefetch distance based on SMP/UP */
7 20
8 .globl copy_page 21ENTRY(copy_page)
9 .p2align 4 22 CFI_STARTPROC
10copy_page:
11 subq $3*8,%rsp 23 subq $3*8,%rsp
24 CFI_ADJUST_CFA_OFFSET 3*8
12 movq %rbx,(%rsp) 25 movq %rbx,(%rsp)
26 CFI_REL_OFFSET rbx, 0
13 movq %r12,1*8(%rsp) 27 movq %r12,1*8(%rsp)
28 CFI_REL_OFFSET r12, 1*8
14 movq %r13,2*8(%rsp) 29 movq %r13,2*8(%rsp)
30 CFI_REL_OFFSET r13, 2*8
15 31
16 movl $(4096/64)-5,%ecx 32 movl $(4096/64)-5,%ecx
17 .p2align 4 33 .p2align 4
@@ -72,30 +88,33 @@ copy_page:
72 jnz .Loop2 88 jnz .Loop2
73 89
74 movq (%rsp),%rbx 90 movq (%rsp),%rbx
91 CFI_RESTORE rbx
75 movq 1*8(%rsp),%r12 92 movq 1*8(%rsp),%r12
93 CFI_RESTORE r12
76 movq 2*8(%rsp),%r13 94 movq 2*8(%rsp),%r13
95 CFI_RESTORE r13
77 addq $3*8,%rsp 96 addq $3*8,%rsp
97 CFI_ADJUST_CFA_OFFSET -3*8
78 ret 98 ret
99.Lcopy_page_end:
100 CFI_ENDPROC
101ENDPROC(copy_page)
79 102
80 /* Some CPUs run faster using the string copy instructions. 103 /* Some CPUs run faster using the string copy instructions.
81 It is also a lot simpler. Use this when possible */ 104 It is also a lot simpler. Use this when possible */
82 105
83#include <asm/cpufeature.h> 106#include <asm/cpufeature.h>
84 107
108 .section .altinstr_replacement,"ax"
1091: .byte 0xeb /* jmp <disp8> */
110 .byte (copy_page_c - copy_page) - (2f - 1b) /* offset */
1112:
112 .previous
85 .section .altinstructions,"a" 113 .section .altinstructions,"a"
86 .align 8 114 .align 8
87 .quad copy_page 115 .quad copy_page
88 .quad copy_page_c 116 .quad 1b
89 .byte X86_FEATURE_REP_GOOD 117 .byte X86_FEATURE_REP_GOOD
90 .byte copy_page_c_end-copy_page_c 118 .byte .Lcopy_page_end - copy_page
91 .byte copy_page_c_end-copy_page_c 119 .byte 2b - 1b
92 .previous
93
94 .section .altinstr_replacement,"ax"
95copy_page_c:
96 movl $4096/8,%ecx
97 rep
98 movsq
99 ret
100copy_page_c_end:
101 .previous 120 .previous