x86/efi: Save and restore FPU context around efi_calls (x86_64)

Do a complete FPU context save/restore around the EFI calls. This required
as runtime EFI firmware may potentially use the FPU.

This change covers only the x86_64 configuration.

Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 19292e7cae58..0b19187cc882 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -1,6 +1,7 @@
 #ifndef _ASM_X86_EFI_H
 #define _ASM_X86_EFI_H
 
+#include <asm/i387.h>
 /*
  * We map the EFI regions needed for runtime services non-contiguously,
  * with preserved alignment on virtual addresses starting from -4G down
@@ -54,7 +55,9 @@ extern u64 asmlinkage efi_call(void *fp, ...);
                                                                         \
         efi_sync_low_kernel_mappings();                                 \
         preempt_disable();                                              \
+        __kernel_fpu_begin();                                           \
         __s = efi_call((void *)efi.systab->runtime->f, __VA_ARGS__);    \
+        __kernel_fpu_end();                                             \
         preempt_enable();                                               \
         __s;                                                            \
 })