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/* Written 2003 by Andi Kleen, based on a kernel by Evandro Menezes */
/* 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 */
.globl copy_page
.p2align 4
copy_page:
subq $3*8,%rsp
movq %rbx,(%rsp)
movq %r12,1*8(%rsp)
movq %r13,2*8(%rsp)
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
movq 1*8(%rsp),%r12
movq 2*8(%rsp),%r13
addq $3*8,%rsp
ret
/* Some CPUs run faster using the string copy instructions.
It is also a lot simpler. Use this when possible */
#include <asm/cpufeature.h>
.section .altinstructions,"a"
.align 8
.quad copy_page
.quad copy_page_c
.byte X86_FEATURE_REP_GOOD
.byte copy_page_c_end-copy_page_c
.byte copy_page_c_end-copy_page_c
.previous
.section .altinstr_replacement,"ax"
copy_page_c:
movl $4096/8,%ecx
rep
movsq
ret
copy_page_c_end:
.previous
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