From: Rafael J. Wysocki <rjw@xxxxxxx>
Since we already pass the address of restore_registers() in the image header,
we can also pass the value of the CR3 register from before the hibernation in
the same way. This will allow us to avoid using init_level4_pgt page tables
during the restore.
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
Acked-by: Pavel Machek <pavel@xxxxxx>
---
arch/x86_64/kernel/suspend.c | 16 ++++++++++++----
arch/x86_64/kernel/suspend_asm.S | 8 +++++---
2 files changed, 17 insertions(+), 7 deletions(-)
Index: linux-2.6.23-rc3/arch/x86_64/kernel/suspend.c
===================================================================
--- linux-2.6.23-rc3.orig/arch/x86_64/kernel/suspend.c 2007-08-25 22:11:43.000000000 +0200
+++ linux-2.6.23-rc3/arch/x86_64/kernel/suspend.c 2007-08-25 22:51:56.000000000 +0200
@@ -150,6 +150,12 @@ extern int restore_image(void);
*/
unsigned long restore_jump_address;
+/*
+ * Value of the cr3 register from before the hibernation (this value is passed
+ * in the image header).
+ */
+unsigned long restore_cr3;
+
pgd_t *temp_level4_pgt;
void *relocated_restore_code;
@@ -248,7 +254,8 @@ int pfn_is_nosave(unsigned long pfn)
struct restore_data_record {
unsigned long jump_address;
- unsigned long control;
+ unsigned long cr3;
+ unsigned long magic;
};
#define RESTORE_MAGIC 0x0123456789ABCDEFUL
@@ -265,7 +272,8 @@ int arch_hibernation_header_save(void *a
if (max_size < sizeof(struct restore_data_record))
return -EOVERFLOW;
rdr->jump_address = restore_jump_address;
- rdr->control = (restore_jump_address ^ RESTORE_MAGIC);
+ rdr->cr3 = restore_cr3;
+ rdr->magic = RESTORE_MAGIC;
return 0;
}
@@ -279,7 +287,7 @@ int arch_hibernation_header_restore(void
struct restore_data_record *rdr = addr;
restore_jump_address = rdr->jump_address;
- return (rdr->control == (restore_jump_address ^ RESTORE_MAGIC)) ?
- 0 : -EINVAL;
+ restore_cr3 = rdr->cr3;
+ return (rdr->magic == RESTORE_MAGIC) ? 0 : -EINVAL;
}
#endif /* CONFIG_HIBERNATION */
Index: linux-2.6.23-rc3/arch/x86_64/kernel/suspend_asm.S
===================================================================
--- linux-2.6.23-rc3.orig/arch/x86_64/kernel/suspend_asm.S 2007-08-25 22:10:25.000000000 +0200
+++ linux-2.6.23-rc3/arch/x86_64/kernel/suspend_asm.S 2007-08-25 22:51:56.000000000 +0200
@@ -39,6 +39,9 @@ ENTRY(swsusp_arch_suspend)
/* 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
@@ -60,6 +63,7 @@ ENTRY(restore_image)
/* 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
@@ -98,9 +102,7 @@ done:
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
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