Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6

[linux-2.6] / arch / x86 / kernel / suspend_asm_64.S

diff --git a/arch/x86/kernel/suspend_asm_64.S b/arch/x86/kernel/suspend_asm_64.S
index 16d183f67bc1e66e790f6160ae54a436554b9041..48344b666d2c2e60f56d3393d82ecc48e0b9388f 100644 (file)
--- a/arch/x86/kernel/suspend_asm_64.S
+++ b/arch/x86/kernel/suspend_asm_64.S
@@ -2,8 +2,8 @@
  *
  * Distribute under GPLv2.
  *
- * swsusp_arch_resume may not use any stack, nor any variable that is
- * not "NoSave" during copying pages:
+ * swsusp_arch_resume must not use any stack or any nonlocal variables while
+ * copying pages:
  *
  * Its rewriting one kernel image with another. What is stack in "old"
  * image could very well be data page in "new" image, and overwriting
@@ -36,6 +36,13 @@ ENTRY(swsusp_arch_suspend)
        movq %r15, saved_context_r15(%rip)
        pushfq ; popq saved_context_eflags(%rip)
 
+       /* save the address of restore_registers */
+       movq    $restore_registers, %rax
+       movq    %rax, restore_jump_address(%rip)
+       /* save cr3 */
+       movq    %cr3, %rax
+       movq    %rax, restore_cr3(%rip)
+
        call swsusp_save
        ret
 
@@ -54,7 +61,17 @@ ENTRY(restore_image)
        movq    %rcx, %cr3;
        movq    %rax, %cr4;  # turn PGE back on
 
+       /* prepare to jump to the image kernel */
+       movq    restore_jump_address(%rip), %rax
+       movq    restore_cr3(%rip), %rbx
+
+       /* prepare to copy image data to their original locations */
        movq    restore_pblist(%rip), %rdx
+       movq    relocated_restore_code(%rip), %rcx
+       jmpq    *%rcx
+
+       /* code below has been relocated to a safe page */
+ENTRY(core_restore_code)
 loop:
        testq   %rdx, %rdx
        jz      done
@@ -62,7 +79,7 @@ loop:
        /* get addresses from the pbe and copy the page */
        movq    pbe_address(%rdx), %rsi
        movq    pbe_orig_address(%rdx), %rdi
-       movq    $512, %rcx
+       movq    $(PAGE_SIZE >> 3), %rcx
        rep
        movsq
 
@@ -70,10 +87,22 @@ loop:
        movq    pbe_next(%rdx), %rdx
        jmp     loop
 done:
+       /* jump to the restore_registers address from the image header */
+       jmpq    *%rax
+       /*
+        * NOTE: This assumes that the boot kernel's text mapping covers the
+        * image kernel's page containing restore_registers and the address of
+        * this page is the same as in the image kernel's text mapping (it
+        * should always be true, because the text mapping is linear, starting
+        * from 0, and is supposed to cover the entire kernel text for every
+        * kernel).
+        *
+        * code below belongs to the image kernel
+        */
+
+ENTRY(restore_registers)
        /* go back to the original page tables */
-       movq    $(init_level4_pgt - __START_KERNEL_map), %rax
-       addq    phys_base(%rip), %rax
-       movq    %rax, %cr3
+       movq    %rbx, %cr3
 
        /* Flush TLB, including "global" things (vmalloc) */
        movq    mmu_cr4_features(%rip), %rax
@@ -84,12 +113,9 @@ done:
        movq    %rcx, %cr3
        movq    %rax, %cr4;  # turn PGE back on
 
-       movl    $24, %eax
-       movl    %eax, %ds
-
        movq saved_context_esp(%rip), %rsp
        movq saved_context_ebp(%rip), %rbp
-       /* Don't restore %rax, it must be 0 anyway */
+       /* restore GPRs (we don't restore %rax, it must be 0 anyway) */
        movq saved_context_ebx(%rip), %rbx
        movq saved_context_ecx(%rip), %rcx
        movq saved_context_edx(%rip), %rdx
@@ -107,4 +133,7 @@ done:
 
        xorq    %rax, %rax
 
+       /* tell the hibernation core that we've just restored the memory */
+       movq    %rax, in_suspend(%rip)
+
        ret