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authorH. Peter Anvin <hpa@linux.intel.com>2012-09-26 15:02:34 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2012-09-26 15:06:22 -0700
commit73201dbec64aebf6b0dca855b523f437972dc7bb (patch)
treefdedca7d530ffda4fcb53cb084ad993555c2f948 /arch/x86/realmode/rm
parent5a5a51db78ef24aa61a4cb2ae36f07f6fa37356d (diff)
downloadlinux-73201dbec64aebf6b0dca855b523f437972dc7bb.tar.bz2
x86, suspend: On wakeup always initialize cr4 and EFER
We already have a flag word to indicate the existence of MISC_ENABLES, so use the same flag word to indicate existence of cr4 and EFER, and always restore them if they exist. That way if something passes a nonzero value when the value *should* be zero, we will still initialize it. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Link: http://lkml.kernel.org/r/1348529239-17943-1-git-send-email-hpa@linux.intel.com
Diffstat (limited to 'arch/x86/realmode/rm')
-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: