v4.19.13 snapshot.
diff --git a/arch/nds32/include/asm/barrier.h b/arch/nds32/include/asm/barrier.h
new file mode 100644
index 0000000..faafc37
--- /dev/null
+++ b/arch/nds32/include/asm/barrier.h
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#ifndef __NDS32_ASM_BARRIER_H
+#define __NDS32_ASM_BARRIER_H
+
+#ifndef __ASSEMBLY__
+#define mb() asm volatile("msync all":::"memory")
+#define rmb() asm volatile("msync all":::"memory")
+#define wmb() asm volatile("msync store":::"memory")
+#include <asm-generic/barrier.h>
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __NDS32_ASM_BARRIER_H */