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/* Written 2003 by Andi Kleen, based on a kernel by Evandro Menezes */
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/alternative-asm.h>
ALIGN
copy_page_c:
CFI_STARTPROC
movl $4096/8,%ecx
rep movsq
ret
CFI_ENDPROC
ENDPROC(copy_page_c)
/* Don't use streaming store because it's better when the target
ends up in cache. */
/* Could vary the prefetch distance based on SMP/UP */
ENTRY(copy_page)
CFI_STARTPROC
subq $2*8,%rsp
CFI_ADJUST_CFA_OFFSET 2*8
movq %rbx,(%rsp)
CFI_REL_OFFSET rbx, 0
movq %r12,1*8(%rsp)
CFI_REL_OFFSET r12, 1*8
movl $(4096/64)-5,%ecx
.p2align 4
.Loop64:
dec %rcx
movq (%rsi), %rax
movq 8 (%rsi), %rbx
movq 16 (%rsi), %rdx
movq 24 (%rsi), %r8
movq 32 (%rsi), %r9
movq 40 (%rsi), %r10
movq 48 (%rsi), %r11
movq 56 (%rsi), %r12
prefetcht0 5*64(%rsi)
movq %rax, (%rdi)
movq %rbx, 8 (%rdi)
movq %rdx, 16 (%rdi)
movq %r8, 24 (%rdi)
movq %r9, 32 (%rdi)
movq %r10, 40 (%rdi)
movq %r11, 48 (%rdi)
movq %r12, 56 (%rdi)
leaq 64 (%rsi), %rsi
leaq 64 (%rdi), %rdi
jnz .Loop64
movl $5,%ecx
.p2align 4
.Loop2:
decl %ecx
movq (%rsi), %rax
movq 8 (%rsi), %rbx
movq 16 (%rsi), %rdx
movq 24 (%rsi), %r8
movq 32 (%rsi), %r9
movq 40 (%rsi), %r10
movq 48 (%rsi), %r11
movq 56 (%rsi), %r12
movq %rax, (%rdi)
movq %rbx, 8 (%rdi)
movq %rdx, 16 (%rdi)
movq %r8, 24 (%rdi)
movq %r9, 32 (%rdi)
movq %r10, 40 (%rdi)
movq %r11, 48 (%rdi)
movq %r12, 56 (%rdi)
leaq 64(%rdi),%rdi
leaq 64(%rsi),%rsi
jnz .Loop2
movq (%rsp),%rbx
CFI_RESTORE rbx
movq 1*8(%rsp),%r12
CFI_RESTORE r12
addq $2*8,%rsp
CFI_ADJUST_CFA_OFFSET -2*8
ret
.Lcopy_page_end:
CFI_ENDPROC
ENDPROC(copy_page)
/* Some CPUs run faster using the string copy 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 (copy_page_c - copy_page) - (2f - 1b) /* offset */
2:
.previous
.section .altinstructions,"a"
altinstruction_entry copy_page, 1b, X86_FEATURE_REP_GOOD, \
.Lcopy_page_end-copy_page, 2b-1b
.previous
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