From: Julien Grall <julien.grall@citrix.com>
Date: Thu, 15 Oct 2015 17:10:15 +0000 (+0100)
Subject: xen: replace barrier by __compiler_membar
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=46bb8cb06523023c96d6b6d873c73d3efed31639;p=people%2Fjulieng%2Ffreebsd.git

xen: replace barrier by __compiler_membar
---

diff --git a/sys/x86/include/xen/xen-os.h b/sys/x86/include/xen/xen-os.h
index dc1ad682e7db..b313a139b1b1 100644
--- a/sys/x86/include/xen/xen-os.h
+++ b/sys/x86/include/xen/xen-os.h
@@ -40,9 +40,6 @@ static inline void rep_nop(void)
 }
 #define cpu_relax() rep_nop()
 
-/* This is a barrier for the compiler only, NOT the processor! */
-#define barrier() __asm__ __volatile__("": : :"memory")
-
 #endif /* !__ASSEMBLY__ */
 
 #endif /* _MACHINE_X86_XEN_XEN_OS_H_ */
diff --git a/sys/xen/blkif.h b/sys/xen/blkif.h
index 8a19d5d01d87..721bb93c3c48 100644
--- a/sys/xen/blkif.h
+++ b/sys/xen/blkif.h
@@ -120,7 +120,7 @@ static void inline blkif_get_x86_32_req(blkif_request_t *dst, blkif_x86_32_reque
 	dst->handle = src->handle;
 	dst->id = src->id;
 	dst->sector_number = src->sector_number;
-	barrier();
+	__compiler_membar();
 	if (n > dst->nr_segments)
 		n = dst->nr_segments;
 	for (i = 0; i < n; i++)
@@ -135,7 +135,7 @@ static void inline blkif_get_x86_64_req(blkif_request_t *dst, blkif_x86_64_reque
 	dst->handle = src->handle;
 	dst->id = src->id;
 	dst->sector_number = src->sector_number;
-	barrier();
+	__compiler_membar();
 	if (n > dst->nr_segments)
 		n = dst->nr_segments;
 	for (i = 0; i < n; i++)