arch/x86/lib/msr-reg.S

   1 #include <linux/linkage.h>
   2 #include <linux/errno.h>
   3 #include <asm/asm.h>
   4 #include <asm/msr.h>
   5
   6 #ifdef CONFIG_X86_64
   7 /*
   8  * int {rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
   9  *
  10  * reg layout: u32 gprs[eax, ecx, edx, ebx, esp, ebp, esi, edi]
  11  *
  12  */
  13 .macro op_safe_regs op
  14 ENTRY(\op\()_safe_regs)
  15         pushq %rbx
  16         pushq %r12
  17         movq    %rdi, %r10      /* Save pointer */
  18         xorl    %r11d, %r11d    /* Return value */
  19         movl    (%rdi), %eax
  20         movl    4(%rdi), %ecx
  21         movl    8(%rdi), %edx
  22         movl    12(%rdi), %ebx
  23         movl    20(%rdi), %r12d
  24         movl    24(%rdi), %esi
  25         movl    28(%rdi), %edi
  26 1:      \op
  27 2:      movl    %eax, (%r10)
  28         movl    %r11d, %eax     /* Return value */
  29         movl    %ecx, 4(%r10)
  30         movl    %edx, 8(%r10)
  31         movl    %ebx, 12(%r10)
  32         movl    %r12d, 20(%r10)
  33         movl    %esi, 24(%r10)
  34         movl    %edi, 28(%r10)
  35         popq %r12
  36         popq %rbx
  37         ret
  38 3:
  39         movl    $-EIO, %r11d
  40         jmp     2b
  41
  42         _ASM_EXTABLE(1b, 3b)
  43 ENDPROC(\op\()_safe_regs)
  44 .endm
  45
  46 #else /* X86_32 */
  47
  48 .macro op_safe_regs op
  49 ENTRY(\op\()_safe_regs)
  50         pushl %ebx
  51         pushl %ebp
  52         pushl %esi
  53         pushl %edi
  54         pushl $0              /* Return value */
  55         pushl %eax
  56         movl    4(%eax), %ecx
  57         movl    8(%eax), %edx
  58         movl    12(%eax), %ebx
  59         movl    20(%eax), %ebp
  60         movl    24(%eax), %esi
  61         movl    28(%eax), %edi
  62         movl    (%eax), %eax
  63 1:      \op
  64 2:      pushl %eax
  65         movl    4(%esp), %eax
  66         popl (%eax)
  67         addl    $4, %esp
  68         movl    %ecx, 4(%eax)
  69         movl    %edx, 8(%eax)
  70         movl    %ebx, 12(%eax)
  71         movl    %ebp, 20(%eax)
  72         movl    %esi, 24(%eax)
  73         movl    %edi, 28(%eax)
  74         popl %eax
  75         popl %edi
  76         popl %esi
  77         popl %ebp
  78         popl %ebx
  79         ret
  80 3:
  81         movl    $-EIO, 4(%esp)
  82         jmp     2b
  83
  84         _ASM_EXTABLE(1b, 3b)
  85 ENDPROC(\op\()_safe_regs)
  86 .endm
  87
  88 #endif
  89
  90 op_safe_regs rdmsr
  91 op_safe_regs wrmsr
  92