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Diffstat (limited to 'arch/x86_64/lib/clear_page.S')
-rw-r--r--arch/x86_64/lib/clear_page.S47
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 1f81b79b796..9a10a78bb4a 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