diff options
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/copy_user_64.S | 10 | ||||
| -rw-r--r-- | arch/x86/lib/memmove_64.S | 13 |
2 files changed, 14 insertions, 9 deletions
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index 4fc5c2de2de4..01c5de4c279b 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -7,6 +7,8 @@ */ #include <linux/linkage.h> +#include <asm/cpufeatures.h> +#include <asm/alternative.h> #include <asm/asm.h> #include <asm/export.h> @@ -29,7 +31,7 @@ */ SYM_FUNC_START(rep_movs_alternative) cmpq $64,%rcx - jae .Lunrolled + jae .Llarge cmp $8,%ecx jae .Lword @@ -65,6 +67,12 @@ SYM_FUNC_START(rep_movs_alternative) _ASM_EXTABLE_UA( 2b, .Lcopy_user_tail) _ASM_EXTABLE_UA( 3b, .Lcopy_user_tail) +.Llarge: +0: ALTERNATIVE "jmp .Lunrolled", "rep movsb", X86_FEATURE_ERMS +1: RET + + _ASM_EXTABLE_UA( 0b, 1b) + .p2align 4 .Lunrolled: 10: movq (%rsi),%r8 diff --git a/arch/x86/lib/memmove_64.S b/arch/x86/lib/memmove_64.S index 02661861e5dd..0559b206fb11 100644 --- a/arch/x86/lib/memmove_64.S +++ b/arch/x86/lib/memmove_64.S @@ -38,10 +38,12 @@ SYM_FUNC_START(__memmove) cmp %rdi, %r8 jg 2f - /* FSRM implies ERMS => no length checks, do the copy directly */ +#define CHECK_LEN cmp $0x20, %rdx; jb 1f +#define MEMMOVE_BYTES movq %rdx, %rcx; rep movsb; RET .Lmemmove_begin_forward: - ALTERNATIVE "cmp $0x20, %rdx; jb 1f", "", X86_FEATURE_FSRM - ALTERNATIVE "", "jmp .Lmemmove_erms", X86_FEATURE_ERMS + ALTERNATIVE_2 __stringify(CHECK_LEN), \ + __stringify(CHECK_LEN; MEMMOVE_BYTES), X86_FEATURE_ERMS, \ + __stringify(MEMMOVE_BYTES), X86_FEATURE_FSRM /* * movsq instruction have many startup latency @@ -207,11 +209,6 @@ SYM_FUNC_START(__memmove) movb %r11b, (%rdi) 13: RET - -.Lmemmove_erms: - movq %rdx, %rcx - rep movsb - RET SYM_FUNC_END(__memmove) EXPORT_SYMBOL(__memmove) |