From: Simon Glass <sjg@chromium.org>
Date: Wed, 10 Oct 2012 13:12:53 +0000 (+0000)
Subject: x86: Add initial memory barrier macros
X-Git-Tag: v2013.01-rc2~103^2~8
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8a487a4417221412d1cd23d4e08253fc9413be51;p=platform%2Fkernel%2Fu-boot.git

x86: Add initial memory barrier macros

These are available on other architectures, so add them on x86.

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

diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index 9b757d4..b12bdd8 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -234,4 +234,12 @@ static inline phys_addr_t virt_to_phys(void * vaddr)
 	return (phys_addr_t)(vaddr);
 }
 
+/*
+ * TODO: The kernel offers some more advanced versions of barriers, it might
+ * have some advantages to use them instead of the simple one here.
+ */
+#define dmb()		__asm__ __volatile__ ("" : : : "memory")
+#define __iormb()	dmb()
+#define __iowmb()	dmb()
+
 #endif