[U-Boot] [PATCH 12/20] x86: Add an mfence macro

[Simon Glass]

Provide access to this x86 instruction from C code.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 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 c839291..37aa6b9 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\t\n" : : : "memory");
+}
+
 /**
  * cpu_enable_paging_pae() - Enable PAE-paging
  *
-- 
2.2.0.rc0.207.ga3a616c