diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c
index a7f3fc342d87..dd5b5a17ece0 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c
@@ -222,8 +222,11 @@ nv50_instobj_acquire(struct nvkm_memory *memory)
 	void __iomem *map = NULL;
 
 	/* Already mapped? */
-	if (refcount_inc_not_zero(&iobj->maps))
+	if (refcount_inc_not_zero(&iobj->maps)) {
+		/* read barrier match the wmb on refcount set */
+		smp_rmb();
 		return iobj->map;
+	}
 
 	/* Take the lock, and re-check that another thread hasn't
 	 * already mapped the object in the meantime.
@@ -250,6 +253,8 @@ nv50_instobj_acquire(struct nvkm_memory *memory)
 			iobj->base.memory.ptrs = &nv50_instobj_fast;
 		else
 			iobj->base.memory.ptrs = &nv50_instobj_slow;
+		/* barrier to ensure the ptrs are written before refcount is set */
+		smp_wmb();
 		refcount_set(&iobj->maps, 1);
 	}