From 837a136fc7cfb712858502a03c8d0ae91bea6e0d Mon Sep 17 00:00:00 2001
From: Simon Glass <sjg@chromium.org>
Date: Tue, 28 Apr 2015 20:25:14 -0600
Subject: [PATCH] x86: Add an mfence macro

Provide access to this x86 instruction from C code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
---
 arch/x86/include/asm/cpu.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index c8392915f1..08284ee295 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -151,6 +151,11 @@ static inline int flag_is_changeable_p(uint32_t flag)
 	return ((f1^f2) & flag) != 0;
 }
 
+static inline void mfence(void)
+{
+	__asm__ __volatile__("mfence" : : : "memory");
+}
+
 /**
  * cpu_enable_paging_pae() - Enable PAE-paging
  *
-- 
2.39.5