Commit 1396adc3 authored Oct 01, 2012 by H. Peter Anvin Committed by Ingo Molnar Oct 02, 2012

x86, suspend: Correct the restore of CR4, EFER; skip computing EFLAGS.ID



The patch:

    73201dbe x86, suspend: On wakeup always initialize cr4 and EFER

... was incorrectly committed in an intermediate (unfinished) form.

- We need to test CF, not ZF, for a bit test with btl.
- We don't actually need to compute the existence of EFLAGS.ID,
  since we set a flag at suspend time if CR4 should be restored.

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


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent b2cc2a07

arch/x86/realmode/rm/wakeup_asm.S

+3 −12

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

		lidtl wakeup_idt

		/* Clear the EFLAGS but remember if we have EFLAGS.ID */
		movl $X86_EFLAGS_ID, %ecx
		pushl %ecx
		popfl
		pushfl
		popl %edi
		/* Clear the EFLAGS */
		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
		@@ -120,12 +111,12 @@ ENTRY(wakeup_start)
		movl %eax, %cr3

		btl $WAKEUP_BEHAVIOR_RESTORE_CR4, %edi
		jz 1f
		jnc 1f
		movl pmode_cr4, %eax
		movl %eax, %cr4
		1:
		btl $WAKEUP_BEHAVIOR_RESTORE_EFER, %edi
		jz 1f
		jnc 1f
		movl pmode_efer, %eax
		movl pmode_efer + 4, %edx
		movl $MSR_EFER, %ecx