Commit 73201dbe authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

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: default avatarH. 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
parent 5a5a51db

arch/x86/kernel/acpi/sleep.c

+10 −5
Original line number Diff line number Diff line
@@ -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,

	if (!rdmsr_safe(MSR_EFER,

			&header->pmode_efer_low,

			&header->pmode_efer_high))

		header->pmode_efer_low = header->pmode_efer_high = 0;

		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))

arch/x86/realmode/rm/wakeup.h

+2 −0
Original line number Diff line number Diff line
@@ -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 */

arch/x86/realmode/rm/wakeup_asm.S

+19 −10
Original line number Diff line number Diff line
@@ -74,9 +74,18 @@ ENTRY(wakeup_start) 


	lidtl	wakeup_idt



	/* Clear the EFLAGS */

	/* 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:

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