From: Simon Glass <sjg@chromium.org>
Date: Wed, 29 Apr 2015 02:25:14 +0000 (-0600)
Subject: x86: Add an mfence macro
X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=837a136fc7cfb712858502a03c8d0ae91bea6e0d;p=u-boot.git

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>
---

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
  *