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
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 1b8e5a0..11676cf 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -43,17 +43,22 @@
header->video_mode = saved_video_mode;
+ header->pmode_behavior = 0;
+
#ifndef CONFIG_64BIT
store_gdt((struct desc_ptr *)&header->pmode_gdt);
- if (rdmsr_safe(MSR_EFER, &header->pmode_efer_low,
- &header->pmode_efer_high))
- header->pmode_efer_low = header->pmode_efer_high = 0;
+ if (!rdmsr_safe(MSR_EFER,
+ &header->pmode_efer_low,
+ &header->pmode_efer_high))
+ header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_EFER);
#endif /* !CONFIG_64BIT */
header->pmode_cr0 = read_cr0();
- header->pmode_cr4 = read_cr4_safe();
- header->pmode_behavior = 0;
+ if (__this_cpu_read(cpu_info.cpuid_level) >= 0) {
+ header->pmode_cr4 = read_cr4();
+ header->pmode_behavior |= (1 << WAKEUP_BEHAVIOR_RESTORE_CR4);
+ }
if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
&header->pmode_misc_en_low,
&header->pmode_misc_en_high))