arch/x86/power/hibernate_asm_32.S

   1 /*
   2  * This may not use any stack, nor any variable that is not "NoSave":
   3  *
   4  * Its rewriting one kernel image with another. What is stack in "old"
   5  * image could very well be data page in "new" image, and overwriting
   6  * your own stack under you is bad idea.
   7  */
   8
   9 #include <linux/linkage.h>
  10 #include <asm/segment.h>
  11 #include <asm/page_types.h>
  12 #include <asm/asm-offsets.h>
  13 #include <asm/processor-flags.h>
  14
  15 .text
  16
  17 ENTRY(swsusp_arch_suspend)
  18         movl %esp, saved_context_esp
  19         movl %ebx, saved_context_ebx
  20         movl %ebp, saved_context_ebp
  21         movl %esi, saved_context_esi
  22         movl %edi, saved_context_edi
  23         pushfl
  24         popl saved_context_eflags
  25
  26         call swsusp_save
  27         ret
  28
  29 ENTRY(restore_image)
  30         movl    mmu_cr4_features, %ecx
  31         movl    resume_pg_dir, %eax
  32         subl    $__PAGE_OFFSET, %eax
  33         movl    %eax, %cr3
  34
  35         jecxz   1f      # cr4 Pentium and higher, skip if zero
  36         andl    $~(X86_CR4_PGE), %ecx
  37         movl    %ecx, %cr4;  # turn off PGE
  38         movl    %cr3, %eax;  # flush TLB
  39         movl    %eax, %cr3
  40 1:
  41         movl    restore_pblist, %edx
  42         .p2align 4,,7
  43
  44 copy_loop:
  45         testl   %edx, %edx
  46         jz      done
  47
  48         movl    pbe_address(%edx), %esi
  49         movl    pbe_orig_address(%edx), %edi
  50
  51         movl    $1024, %ecx
  52         rep
  53         movsl
  54
  55         movl    pbe_next(%edx), %edx
  56         jmp     copy_loop
  57         .p2align 4,,7
  58
  59 done:
  60         /* go back to the original page tables */
  61         movl    $swapper_pg_dir, %eax
  62         subl    $__PAGE_OFFSET, %eax
  63         movl    %eax, %cr3
  64         movl    mmu_cr4_features, %ecx
  65         jecxz   1f      # cr4 Pentium and higher, skip if zero
  66         movl    %ecx, %cr4;  # turn PGE back on
  67 1:
  68
  69         movl saved_context_esp, %esp
  70         movl saved_context_ebp, %ebp
  71         movl saved_context_ebx, %ebx
  72         movl saved_context_esi, %esi
  73         movl saved_context_edi, %edi
  74
  75         pushl saved_context_eflags
  76         popfl
  77
  78         /* Saved in save_processor_state. */
  79         movl $saved_context, %eax
  80         lgdt saved_context_gdt_desc(%eax)
  81
  82         xorl    %eax, %eax
  83
  84         ret