60 строки
969 B
ArmAsm
60 строки
969 B
ArmAsm
|
#include <linux/linkage.h>
|
||
|
|
#include <asm/dwarf2.h>
|
||
|
|
|
||
|
/*
|
||
|
|
* Zero a page.
|
||
|
|
* rdi 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
|
||
|
|
.Lloop:
|
||
|
|
decl %ecx
|
||
|
|
#define PUT(x) movq %rax,x*8(%rdi)
|
||
|
|
movq %rax,(%rdi)
|
||
|
|
PUT(1)
|
||
|
|
PUT(2)
|
||
|
|
PUT(3)
|
||
|
|
PUT(4)
|
||
|
|
PUT(5)
|
||
|
|
PUT(6)
|
||
|
|
PUT(7)
|
||
|
|
leaq 64(%rdi),%rdi
|
||
|
|
jnz .Lloop
|
||
|
|
nop
|
||
|
|
ret
|
||
|
|
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 1b
|
||
|
|
.byte X86_FEATURE_REP_GOOD
|
||
|
|
.byte .Lclear_page_end - clear_page
|
||
|
|
.byte 2b - 1b
|
||
|
|
.previous
|