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-rw-r--r--arch/x86/realmode/rm/wakeup.h2
-rw-r--r--arch/x86/realmode/rm/wakeup_asm.S29
2 files changed, 21 insertions, 10 deletions
diff --git a/arch/x86/realmode/rm/wakeup.h b/arch/x86/realmode/rm/wakeup.h
index 9317e0042f24..7dd86a419f5d 100644
--- a/arch/x86/realmode/rm/wakeup.h
+++ b/arch/x86/realmode/rm/wakeup.h
@@ -36,5 +36,7 @@ extern struct wakeup_header wakeup_header;
/* Wakeup behavior bits */
#define WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE 0
+#define WAKEUP_BEHAVIOR_RESTORE_CR4 1
+#define WAKEUP_BEHAVIOR_RESTORE_EFER 2
#endif /* ARCH_X86_KERNEL_ACPI_RM_WAKEUP_H */
diff --git a/arch/x86/realmode/rm/wakeup_asm.S b/arch/x86/realmode/rm/wakeup_asm.S
index 8905166b0bbb..e56479e58053 100644
--- a/arch/x86/realmode/rm/wakeup_asm.S
+++ b/arch/x86/realmode/rm/wakeup_asm.S
@@ -74,9 +74,18 @@ ENTRY(wakeup_start)
lidtl wakeup_idt
- /* Clear the EFLAGS */
- pushl $0
+ /* Clear the EFLAGS but remember if we have EFLAGS.ID */
+ movl $X86_EFLAGS_ID, %ecx
+ pushl %ecx
popfl
+ pushfl
+ popl %edi
+ pushl $0
+ popfl
+ pushfl
+ popl %edx
+ xorl %edx, %edi
+ andl %ecx, %edi /* %edi is zero iff CPUID & %cr4 are missing */
/* Check header signature... */
movl signature, %eax
@@ -93,8 +102,8 @@ ENTRY(wakeup_start)
/* Restore MISC_ENABLE before entering protected mode, in case
BIOS decided to clear XD_DISABLE during S3. */
- movl pmode_behavior, %eax
- btl $WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE, %eax
+ movl pmode_behavior, %edi
+ btl $WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE, %edi
jnc 1f
movl pmode_misc_en, %eax
@@ -110,15 +119,15 @@ ENTRY(wakeup_start)
movl pmode_cr3, %eax
movl %eax, %cr3
- movl pmode_cr4, %ecx
- jecxz 1f
- movl %ecx, %cr4
+ btl $WAKEUP_BEHAVIOR_RESTORE_CR4, %edi
+ jz 1f
+ movl pmode_cr4, %eax
+ movl %eax, %cr4
1:
+ btl $WAKEUP_BEHAVIOR_RESTORE_EFER, %edi
+ jz 1f
movl pmode_efer, %eax
movl pmode_efer + 4, %edx
- movl %eax, %ecx
- orl %edx, %ecx
- jz 1f
movl $MSR_EFER, %ecx
wrmsr
1: