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path: root/arch/x86/kernel/suspend_asm_64.S
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Diffstat (limited to 'arch/x86/kernel/suspend_asm_64.S')
-rw-r--r--arch/x86/kernel/suspend_asm_64.S49
1 files changed, 39 insertions, 10 deletions
diff --git a/arch/x86/kernel/suspend_asm_64.S b/arch/x86/kernel/suspend_asm_64.S
index 16d183f67bc..48344b666d2 100644
--- 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