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Diffstat (limited to 'arch/x86/lib/memcpy_64.S')
-rw-r--r--arch/x86/lib/memcpy_64.S23
1 files changed, 8 insertions, 15 deletions
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index ad5441ed1b57..f82e884928af 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -20,12 +20,11 @@
20/* 20/*
21 * memcpy_c() - fast string ops (REP MOVSQ) based variant. 21 * memcpy_c() - fast string ops (REP MOVSQ) based variant.
22 * 22 *
23 * Calls to this get patched into the kernel image via the 23 * This gets patched over the unrolled variant (below) via the
24 * alternative instructions framework: 24 * alternative instructions framework:
25 */ 25 */
26 ALIGN 26 .section .altinstr_replacement, "ax", @progbits
27memcpy_c: 27.Lmemcpy_c:
28 CFI_STARTPROC
29 movq %rdi, %rax 28 movq %rdi, %rax
30 29
31 movl %edx, %ecx 30 movl %edx, %ecx
@@ -35,8 +34,8 @@ memcpy_c:
35 movl %edx, %ecx 34 movl %edx, %ecx
36 rep movsb 35 rep movsb
37 ret 36 ret
38 CFI_ENDPROC 37.Lmemcpy_e:
39ENDPROC(memcpy_c) 38 .previous
40 39
41ENTRY(__memcpy) 40ENTRY(__memcpy)
42ENTRY(memcpy) 41ENTRY(memcpy)
@@ -128,16 +127,10 @@ ENDPROC(__memcpy)
128 * It is also a lot simpler. Use this when possible: 127 * It is also a lot simpler. Use this when possible:
129 */ 128 */
130 129
131 .section .altinstr_replacement, "ax"
1321: .byte 0xeb /* jmp <disp8> */
133 .byte (memcpy_c - memcpy) - (2f - 1b) /* offset */
1342:
135 .previous
136
137 .section .altinstructions, "a" 130 .section .altinstructions, "a"
138 .align 8 131 .align 8
139 .quad memcpy 132 .quad memcpy
140 .quad 1b 133 .quad .Lmemcpy_c
141 .byte X86_FEATURE_REP_GOOD 134 .byte X86_FEATURE_REP_GOOD
142 135
143 /* 136 /*
@@ -145,6 +138,6 @@ ENDPROC(__memcpy)
145 * so it is silly to overwrite itself with nops - reboot is the 138 * so it is silly to overwrite itself with nops - reboot is the
146 * only outcome... 139 * only outcome...
147 */ 140 */
148 .byte 2b - 1b 141 .byte .Lmemcpy_e - .Lmemcpy_c
149 .byte 2b - 1b 142 .byte .Lmemcpy_e - .Lmemcpy_c
150 .previous 143 .previous