x86: Create clflush() inline, remove hardcoded wbinvd

Create an inline function for clflush(), with the proper arguments,
and use it instead of hard-coding the instruction.

This also removes one instance of hard-coded wbinvd, based on a patch
by Bauder de Oliveira Costa.

[ tglx: arch/x86 adaptation ]

Cc: Andi Kleen <andi@firstfloor.org>
Cc: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/mm/pageattr_64.c b/arch/x86/mm/pageattr_64.c
index 93d795d..8a4f65b 100644
--- a/arch/x86/mm/pageattr_64.c
+++ b/arch/x86/mm/pageattr_64.c
@@ -65,7 +65,7 @@
 {
 	int i;
 	for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
-		asm volatile("clflush (%0)" :: "r" (adr + i));
+		clflush(adr+i);
 }
 
 static void flush_kernel_map(void *arg)