1 files changed, 7 insertions, 0 deletions

diff --git a/arch/um/include/sysdep-x86_64/barrier.h b/arch/um/include/sysdep-x86_64/barrier.h
new file mode 100644
index 000000000000..7b610befdc8f
--- /dev/null
+++ b/arch/um/include/sysdep-x86_64/barrier.h
@@ -0,0 +1,7 @@
+#ifndef __SYSDEP_X86_64_BARRIER_H
+#define __SYSDEP_X86_64_BARRIER_H
+
+/* Copied from include/asm-x86_64 for use by userspace. */
+#define mb()    asm volatile("mfence":::"memory")
+
+#endif