From 1c1ef02b3dfb227b0b9065e6df5fe483a17bf622 Mon Sep 17 00:00:00 2001
From: Christian Hergert <chergert@redhat.com>
Date: Tue, 23 Aug 2016 10:08:37 -0700
Subject: [PATCH] util: add full memory barrier fallback

---
 lib/util/util.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/util/util.h b/lib/util/util.h
index 6062d439..7c19c327 100644
--- a/lib/util/util.h
+++ b/lib/util/util.h
@@ -33,4 +33,12 @@
 #define read_barrier()           asm volatile("dsb" ::: "memory")
 #endif
 
+/*
+ * Fallback to a full memory barrier if the architecture is not yet
+ * supported with a lighter read barrier.
+ */
+#ifndef read_barrier
+#define read_barrier()           __sync_synchronize()
+#endif
+
 #endif /* SP_UTIL_H */