x86/efi: Save and restore FPU context around efi_calls (i386)

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 i386 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, 15 insertions, 2 deletions

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 0b19187cc882..1eb5f6433ad8 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -34,10 +34,23 @@ extern unsigned long asmlinkage efi_call_phys(void *, ...);
 
 /* Use this macro if your virtual returns a non-void value */
 #define efi_call_virt(f, args...) \
-        ((efi_##f##_t __attribute__((regparm(0)))*)efi.systab->runtime->f)(args)
+({                                                                      \
+        efi_status_t __s;                                               \
+        kernel_fpu_begin();                                             \
+        __s = ((efi_##f##_t __attribute__((regparm(0)))*)               \
+                efi.systab->runtime->f)(args);                          \
+        kernel_fpu_end();                                               \
+        __s;                                                            \
+})
 
 /* Use this macro if your virtual call does not return any value */
-#define __efi_call_virt(f, args...) efi_call_virt(f, args)
+#define __efi_call_virt(f, args...) \
+({                                                                      \
+        kernel_fpu_begin();                                             \
+        ((efi_##f##_t __attribute__((regparm(0)))*)                     \
+                efi.systab->runtime->f)(args);                          \
+        kernel_fpu_end();                                               \
+})
 
 #define efi_ioremap(addr, size, type, attr)     ioremap_cache(addr, size)