diff options
Diffstat (limited to 'arch/x86_64/lib/clear_page.S')
| -rw-r--r-- | arch/x86_64/lib/clear_page.S | 47 |
1 files changed, 28 insertions, 19 deletions
diff --git a/arch/x86_64/lib/clear_page.S b/arch/x86_64/lib/clear_page.S index 1f81b79b796c..9a10a78bb4a4 100644 --- a/arch/x86_64/lib/clear_page.S +++ b/arch/x86_64/lib/clear_page.S @@ -1,10 +1,22 @@ +#include <linux/linkage.h> +#include <asm/dwarf2.h> + /* * Zero a page. * rdi page */ - .globl clear_page - .p2align 4 -clear_page: + ALIGN +clear_page_c: + CFI_STARTPROC + movl $4096/8,%ecx + xorl %eax,%eax + rep stosq + ret + CFI_ENDPROC +ENDPROC(clear_page) + +ENTRY(clear_page) + CFI_STARTPROC xorl %eax,%eax movl $4096/64,%ecx .p2align 4 @@ -23,28 +35,25 @@ clear_page: jnz .Lloop nop ret -clear_page_end: + CFI_ENDPROC +.Lclear_page_end: +ENDPROC(clear_page) /* Some CPUs run faster using the string instructions. It is also a lot simpler. Use this when possible */ #include <asm/cpufeature.h> + .section .altinstr_replacement,"ax" +1: .byte 0xeb /* jmp <disp8> */ + .byte (clear_page_c - clear_page) - (2f - 1b) /* offset */ +2: + .previous .section .altinstructions,"a" .align 8 - .quad clear_page - .quad clear_page_c - .byte X86_FEATURE_REP_GOOD - .byte clear_page_end-clear_page - .byte clear_page_c_end-clear_page_c - .previous - - .section .altinstr_replacement,"ax" -clear_page_c: - movl $4096/8,%ecx - xorl %eax,%eax - rep - stosq - ret -clear_page_c_end: + .quad clear_page + .quad 1b + .byte X86_FEATURE_REP_GOOD + .byte .Lclear_page_end - clear_page + .byte 2b - 1b .previous |