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-rw-r--r--arch/x86_64/lib/copy_page.S87
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/x86_64/lib/copy_page.S b/arch/x86_64/lib/copy_page.S
index 621a197..8fa19d9 100644
--- a/arch/x86_64/lib/copy_page.S
+++ b/arch/x86_64/lib/copy_page.S
@@ -8,7 +8,94 @@
.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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