arch/x86/lib/copy_page_64.S

   1 /* Written 2003 by Andi Kleen, based on a kernel by Evandro Menezes */
   2
   3 #include <linux/linkage.h>
   4 #include <asm/cpufeatures.h>
   5 #include <asm/alternative-asm.h>
   6 #include <asm/export.h>
   7
   8 /*
   9  * Some CPUs run faster using the string copy instructions (sane microcode).
  10  * It is also a lot simpler. Use this when possible. But, don't use streaming
  11  * copy unless the CPU indicates X86_FEATURE_REP_GOOD. Could vary the
  12  * prefetch distance based on SMP/UP.
  13  */
  14         ALIGN
  15 ENTRY(copy_page)
  16         ALTERNATIVE "jmp copy_page_regs", "", X86_FEATURE_REP_GOOD
  17         movl    $4096/8, %ecx
  18         rep     movsq
  19         ret
  20 ENDPROC(copy_page)
  21 EXPORT_SYMBOL(copy_page)
  22
  23 ENTRY(copy_page_regs)
  24         subq    $2*8,   %rsp
  25         movq    %rbx,   (%rsp)
  26         movq    %r12,   1*8(%rsp)
  27
  28         movl    $(4096/64)-5,   %ecx
  29         .p2align 4
  30 .Loop64:
  31         dec     %rcx
  32         movq    0x8*0(%rsi), %rax
  33         movq    0x8*1(%rsi), %rbx
  34         movq    0x8*2(%rsi), %rdx
  35         movq    0x8*3(%rsi), %r8
  36         movq    0x8*4(%rsi), %r9
  37         movq    0x8*5(%rsi), %r10
  38         movq    0x8*6(%rsi), %r11
  39         movq    0x8*7(%rsi), %r12
  40
  41         prefetcht0 5*64(%rsi)
  42
  43         movq    %rax, 0x8*0(%rdi)
  44         movq    %rbx, 0x8*1(%rdi)
  45         movq    %rdx, 0x8*2(%rdi)
  46         movq    %r8,  0x8*3(%rdi)
  47         movq    %r9,  0x8*4(%rdi)
  48         movq    %r10, 0x8*5(%rdi)
  49         movq    %r11, 0x8*6(%rdi)
  50         movq    %r12, 0x8*7(%rdi)
  51
  52         leaq    64 (%rsi), %rsi
  53         leaq    64 (%rdi), %rdi
  54
  55         jnz     .Loop64
  56
  57         movl    $5, %ecx
  58         .p2align 4
  59 .Loop2:
  60         decl    %ecx
  61
  62         movq    0x8*0(%rsi), %rax
  63         movq    0x8*1(%rsi), %rbx
  64         movq    0x8*2(%rsi), %rdx
  65         movq    0x8*3(%rsi), %r8
  66         movq    0x8*4(%rsi), %r9
  67         movq    0x8*5(%rsi), %r10
  68         movq    0x8*6(%rsi), %r11
  69         movq    0x8*7(%rsi), %r12
  70
  71         movq    %rax, 0x8*0(%rdi)
  72         movq    %rbx, 0x8*1(%rdi)
  73         movq    %rdx, 0x8*2(%rdi)
  74         movq    %r8,  0x8*3(%rdi)
  75         movq    %r9,  0x8*4(%rdi)
  76         movq    %r10, 0x8*5(%rdi)
  77         movq    %r11, 0x8*6(%rdi)
  78         movq    %r12, 0x8*7(%rdi)
  79
  80         leaq    64(%rdi), %rdi
  81         leaq    64(%rsi), %rsi
  82         jnz     .Loop2
  83
  84         movq    (%rsp), %rbx
  85         movq    1*8(%rsp), %r12
  86         addq    $2*8, %rsp
  87         ret
  88 ENDPROC(copy_page_regs)