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59e97e4d6f
This save a few bytes on x86-64 and means that future patches can apply alternatives to unrelocated code. Signed-off-by: Andy Lutomirski <luto@mit.edu> Link: http://lkml.kernel.org/r/ff64a6b9a1a3860ca4a7b8b6dc7b4754f9491cd7.1310563276.git.luto@mit.edu Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
117 lines
2.3 KiB
ArmAsm
117 lines
2.3 KiB
ArmAsm
/* Written 2003 by Andi Kleen, based on a kernel by Evandro Menezes */
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#include <linux/linkage.h>
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#include <asm/dwarf2.h>
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#include <asm/alternative-asm.h>
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ALIGN
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copy_page_c:
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CFI_STARTPROC
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movl $4096/8,%ecx
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rep movsq
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ret
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CFI_ENDPROC
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ENDPROC(copy_page_c)
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/* Don't use streaming store because it's better when the target
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ends up in cache. */
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/* Could vary the prefetch distance based on SMP/UP */
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ENTRY(copy_page)
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CFI_STARTPROC
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subq $3*8,%rsp
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CFI_ADJUST_CFA_OFFSET 3*8
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movq %rbx,(%rsp)
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CFI_REL_OFFSET rbx, 0
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movq %r12,1*8(%rsp)
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CFI_REL_OFFSET r12, 1*8
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movq %r13,2*8(%rsp)
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CFI_REL_OFFSET r13, 2*8
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movl $(4096/64)-5,%ecx
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.p2align 4
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.Loop64:
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dec %rcx
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movq (%rsi), %rax
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movq 8 (%rsi), %rbx
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movq 16 (%rsi), %rdx
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movq 24 (%rsi), %r8
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movq 32 (%rsi), %r9
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movq 40 (%rsi), %r10
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movq 48 (%rsi), %r11
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movq 56 (%rsi), %r12
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prefetcht0 5*64(%rsi)
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movq %rax, (%rdi)
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movq %rbx, 8 (%rdi)
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movq %rdx, 16 (%rdi)
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movq %r8, 24 (%rdi)
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movq %r9, 32 (%rdi)
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movq %r10, 40 (%rdi)
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movq %r11, 48 (%rdi)
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movq %r12, 56 (%rdi)
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leaq 64 (%rsi), %rsi
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leaq 64 (%rdi), %rdi
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jnz .Loop64
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movl $5,%ecx
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.p2align 4
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.Loop2:
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decl %ecx
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movq (%rsi), %rax
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movq 8 (%rsi), %rbx
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movq 16 (%rsi), %rdx
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movq 24 (%rsi), %r8
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movq 32 (%rsi), %r9
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movq 40 (%rsi), %r10
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movq 48 (%rsi), %r11
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movq 56 (%rsi), %r12
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movq %rax, (%rdi)
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movq %rbx, 8 (%rdi)
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movq %rdx, 16 (%rdi)
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movq %r8, 24 (%rdi)
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movq %r9, 32 (%rdi)
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movq %r10, 40 (%rdi)
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movq %r11, 48 (%rdi)
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movq %r12, 56 (%rdi)
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leaq 64(%rdi),%rdi
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leaq 64(%rsi),%rsi
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jnz .Loop2
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movq (%rsp),%rbx
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CFI_RESTORE rbx
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movq 1*8(%rsp),%r12
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CFI_RESTORE r12
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movq 2*8(%rsp),%r13
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CFI_RESTORE r13
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addq $3*8,%rsp
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CFI_ADJUST_CFA_OFFSET -3*8
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ret
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.Lcopy_page_end:
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CFI_ENDPROC
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ENDPROC(copy_page)
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/* Some CPUs run faster using the string copy instructions.
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It is also a lot simpler. Use this when possible */
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#include <asm/cpufeature.h>
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.section .altinstr_replacement,"ax"
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1: .byte 0xeb /* jmp <disp8> */
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.byte (copy_page_c - copy_page) - (2f - 1b) /* offset */
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2:
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.previous
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.section .altinstructions,"a"
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altinstruction_entry copy_page, 1b, X86_FEATURE_REP_GOOD, \
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.Lcopy_page_end-copy_page, 2b-1b
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.previous
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