[PATCH] x86-64: Add EFER to the register set saved by save_processor_state

EFER varies like %cr4 depending on the cpu capabilities, and which cpu
capabilities we want to make use of.  So save/restore it make certain
we have the same EFER value when we are done.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86_64/kernel/suspend.c b/arch/x86_64/kernel/suspend.c
index 91f7e678bae7..fe865ea4df52 100644
--- a/arch/x86_64/kernel/suspend.c
+++ b/arch/x86_64/kernel/suspend.c
@@ -33,7 +33,6 @@ void __save_processor_state(struct saved_context *ctxt)
         asm volatile ("str %0"  : "=m" (ctxt->tr));
 
         /* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
-        /* EFER should be constant for kernel version, no need to handle it. */
         /*
          * segment registers
          */
@@ -50,6 +49,7 @@ void __save_processor_state(struct saved_context *ctxt)
         /*
          * control registers 
          */
+        rdmsrl(MSR_EFER, ctxt->efer);
         asm volatile ("movq %%cr0, %0" : "=r" (ctxt->cr0));
         asm volatile ("movq %%cr2, %0" : "=r" (ctxt->cr2));
         asm volatile ("movq %%cr3, %0" : "=r" (ctxt->cr3));
@@ -75,6 +75,7 @@ void __restore_processor_state(struct saved_context *ctxt)
         /*
          * control registers
          */
+        wrmsrl(MSR_EFER, ctxt->efer);
         asm volatile ("movq %0, %%cr8" :: "r" (ctxt->cr8));
         asm volatile ("movq %0, %%cr4" :: "r" (ctxt->cr4));
         asm volatile ("movq %0, %%cr3" :: "r" (ctxt->cr3));