From fd783df94bf9d3403fb9cdfaf994aaea362d7a22 Mon Sep 17 00:00:00 2001
From: jsg <jsg@openbsd.org>
Date: Tue, 21 Oct 2025 03:06:42 +0000
Subject: [PATCH] if an MD version of smp_mb() is not defined, use mb()

---
 sys/dev/pci/drm/include/linux/atomic.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sys/dev/pci/drm/include/linux/atomic.h b/sys/dev/pci/drm/include/linux/atomic.h
index 1d2f54b424c..70ac8b40f04 100644
--- a/sys/dev/pci/drm/include/linux/atomic.h
+++ b/sys/dev/pci/drm/include/linux/atomic.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: atomic.h,v 1.29 2025/10/21 02:55:48 jsg Exp $ */
+/* $OpenBSD: atomic.h,v 1.30 2025/10/21 03:06:42 jsg Exp $ */
 /**
  * \file drm_atomic.h
  * Atomic operations used in the DRM which may or may not be provided by the OS.
@@ -467,6 +467,10 @@ find_next_bit(const volatile void *p, int max, int b)
 #define smp_wmb()	wmb()
 #endif
 
+#ifndef smp_mb
+#define smp_mb()	mb()
+#endif
+
 #ifndef mmiowb
 #define mmiowb()	wmb()
 #endif