LXR linux/arch/x86/power/hibernate_asm

   1/*
   2 * Hibernation support for x86-64
   3 *
   4 * Distribute under GPLv2.
   5 *
   6 * Copyright 2007 Rafael J. Wysocki <rjw@sisk.pl>
   7 * Copyright 2005 Andi Kleen <ak@suse.de>
   8 * Copyright 2004 Pavel Machek <pavel@suse.cz>
   9 *
  10 * swsusp_arch_resume must not use any stack or any nonlocal variables while
  11 * copying pages:
  12 *
  13 * Its rewriting one kernel image with another. What is stack in "old"
  14 * image could very well be data page in "new" image, and overwriting
  15 * your own stack under you is bad idea.
  16 */
  17
  18        .text
  19#include <linux/linkage.h>
  20#include <asm/segment.h>
  21#include <asm/page_types.h>
  22#include <asm/asm-offsets.h>
  23#include <asm/processor-flags.h>
  24#include <asm/frame.h>
  25
  26ENTRY(swsusp_arch_suspend)
  27        FRAME_BEGIN
  28        movq    $saved_context, %rax
  29        movq    %rsp, pt_regs_sp(%rax)
  30        movq    %rbp, pt_regs_bp(%rax)
  31        movq    %rsi, pt_regs_si(%rax)
  32        movq    %rdi, pt_regs_di(%rax)
  33        movq    %rbx, pt_regs_bx(%rax)
  34        movq    %rcx, pt_regs_cx(%rax)
  35        movq    %rdx, pt_regs_dx(%rax)
  36        movq    %r8, pt_regs_r8(%rax)
  37        movq    %r9, pt_regs_r9(%rax)
  38        movq    %r10, pt_regs_r10(%rax)
  39        movq    %r11, pt_regs_r11(%rax)
  40        movq    %r12, pt_regs_r12(%rax)
  41        movq    %r13, pt_regs_r13(%rax)
  42        movq    %r14, pt_regs_r14(%rax)
  43        movq    %r15, pt_regs_r15(%rax)
  44        pushfq
  45        popq    pt_regs_flags(%rax)
  46
  47        /* save the address of restore_registers */
  48        movq    $restore_registers, %rax
  49        movq    %rax, restore_jump_address(%rip)
  50        /* save cr3 */
  51        movq    %cr3, %rax
  52        movq    %rax, restore_cr3(%rip)
  53
  54        call swsusp_save
  55        FRAME_END
  56        ret
  57ENDPROC(swsusp_arch_suspend)
  58
  59ENTRY(restore_image)
  60        /* switch to temporary page tables */
  61        movq    $__PAGE_OFFSET, %rdx
  62        movq    temp_level4_pgt(%rip), %rax
  63        subq    %rdx, %rax
  64        movq    %rax, %cr3
  65        /* Flush TLB */
  66        movq    mmu_cr4_features(%rip), %rax
  67        movq    %rax, %rdx
  68        andq    $~(X86_CR4_PGE), %rdx
  69        movq    %rdx, %cr4;  # turn off PGE
  70        movq    %cr3, %rcx;  # flush TLB
  71        movq    %rcx, %cr3;
  72        movq    %rax, %cr4;  # turn PGE back on
  73
  74        /* prepare to jump to the image kernel */
  75        movq    restore_jump_address(%rip), %rax
  76        movq    restore_cr3(%rip), %rbx
  77
  78        /* prepare to copy image data to their original locations */
  79        movq    restore_pblist(%rip), %rdx
  80        movq    relocated_restore_code(%rip), %rcx
  81        jmpq    *%rcx
  82
  83        /* code below has been relocated to a safe page */
  84ENTRY(core_restore_code)
  85.Lloop:
  86        testq   %rdx, %rdx
  87        jz      .Ldone
  88
  89        /* get addresses from the pbe and copy the page */
  90        movq    pbe_address(%rdx), %rsi
  91        movq    pbe_orig_address(%rdx), %rdi
  92        movq    $(PAGE_SIZE >> 3), %rcx
  93        rep
  94        movsq
  95
  96        /* progress to the next pbe */
  97        movq    pbe_next(%rdx), %rdx
  98        jmp     .Lloop
  99.Ldone:
 100        /* jump to the restore_registers address from the image header */
 101        jmpq    *%rax
 102        /*
 103         * NOTE: This assumes that the boot kernel's text mapping covers the
 104         * image kernel's page containing restore_registers and the address of
 105         * this page is the same as in the image kernel's text mapping (it
 106         * should always be true, because the text mapping is linear, starting
 107         * from 0, and is supposed to cover the entire kernel text for every
 108         * kernel).
 109         *
 110         * code below belongs to the image kernel
 111         */
 112
 113ENTRY(restore_registers)
 114        FRAME_BEGIN
 115        /* go back to the original page tables */
 116        movq    %rbx, %cr3
 117
 118        /* Flush TLB, including "global" things (vmalloc) */
 119        movq    mmu_cr4_features(%rip), %rax
 120        movq    %rax, %rdx
 121        andq    $~(X86_CR4_PGE), %rdx
 122        movq    %rdx, %cr4;  # turn off PGE
 123        movq    %cr3, %rcx;  # flush TLB
 124        movq    %rcx, %cr3
 125        movq    %rax, %cr4;  # turn PGE back on
 126
 127        /* We don't restore %rax, it must be 0 anyway */
 128        movq    $saved_context, %rax
 129        movq    pt_regs_sp(%rax), %rsp
 130        movq    pt_regs_bp(%rax), %rbp
 131        movq    pt_regs_si(%rax), %rsi
 132        movq    pt_regs_di(%rax), %rdi
 133        movq    pt_regs_bx(%rax), %rbx
 134        movq    pt_regs_cx(%rax), %rcx
 135        movq    pt_regs_dx(%rax), %rdx
 136        movq    pt_regs_r8(%rax), %r8
 137        movq    pt_regs_r9(%rax), %r9
 138        movq    pt_regs_r10(%rax), %r10
 139        movq    pt_regs_r11(%rax), %r11
 140        movq    pt_regs_r12(%rax), %r12
 141        movq    pt_regs_r13(%rax), %r13
 142        movq    pt_regs_r14(%rax), %r14
 143        movq    pt_regs_r15(%rax), %r15
 144        pushq   pt_regs_flags(%rax)
 145        popfq
 146
 147        /* Saved in save_processor_state. */
 148        lgdt    saved_context_gdt_desc(%rax)
 149
 150        xorq    %rax, %rax
 151
 152        /* tell the hibernation core that we've just restored the memory */
 153        movq    %rax, in_suspend(%rip)
 154
 155        FRAME_END
 156        ret
 157ENDPROC(restore_registers)
 158