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x86, suspend: On wakeup always initialize cr4 and EFER

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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
This commit is contained in:
H. Peter Anvin 2012-09-26 15:02:34 -07:00
parent 5a5a51db78
commit 73201dbec6
3 changed files with 31 additions and 15 deletions
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15
arch/x86/kernel/acpi/sleep.c
View file

@ -43,17 +43,22 @@ int acpi_suspend_lowlevel(void)
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))

2
arch/x86/realmode/rm/wakeup.h
View file

@ -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 */

29
arch/x86/realmode/rm/wakeup_asm.S
View file

@ -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: