[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>

diff --git a/arch/x86_64/kernel/suspend.c b/arch/x86_64/kernel/suspend.c
index 91f7e678bae72e7f5e951919633ff15d6f12451a..fe865ea4df52c3dfaf29e36884d1554094596d90 100644 (file)
--- 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));

diff --git a/include/asm-x86_64/suspend.h b/include/asm-x86_64/suspend.h
index bc7f81715e5e42acbafe9494f4c954277208fd9b..a42306c220d6dcd74851850af0e6090d86eca592 100644 (file)
--- a/include/asm-x86_64/suspend.h
+++ b/include/asm-x86_64/suspend.h
@@ -17,6 +17,7 @@ struct saved_context {
        u16 ds, es, fs, gs, ss;
        unsigned long gs_base, gs_kernel_base, fs_base;
        unsigned long cr0, cr2, cr3, cr4, cr8;
+       unsigned long efer;
        u16 gdt_pad;
        u16 gdt_limit;
        unsigned long gdt_base;