x86, fpu: Use static_cpu_has() to implement use_xsave()

use_xsave() is now just a special case of static_cpu_has(), so use
static_cpu_has().

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1273135546-29690-2-git-send-email-avi@redhat.com>

arch/x86/include/asm/i387.h

@@ -18,6 +18,7 @@
 #include <linux/hardirq.h>
 #include <linux/slab.h>
 #include <asm/asm.h>
+#include <asm/cpufeature.h>
 #include <asm/processor.h>
 #include <asm/sigcontext.h>
 #include <asm/user.h>
@@ -57,16 +58,9 @@ extern int restore_i387_xstate_ia32(void __user *buf);
 
 #define X87_FSW_ES (1 << 7)	/* Exception Summary */
 
-static inline bool use_xsave(void)
+static __always_inline __pure bool use_xsave(void)
 {
-	u8 has_xsave;
-
-	alternative_io("mov $0, %0",
-		       "mov $1, %0",
-		       X86_FEATURE_XSAVE,
-		       "=qm" (has_xsave));
-
-	return has_xsave;
+	return static_cpu_has(X86_FEATURE_XSAVE);
 }
 
 #ifdef CONFIG_X86_64