From e4bf8fd0cb0e4d9899e1ead86737575b3c5deba9 Mon Sep 17 00:00:00 2001
From: kettenis <kettenis@openbsd.org>
Date: Thu, 29 Dec 2022 11:30:58 +0000
Subject: [PATCH] Use an iorw fence since we're syncing cpu access and device
 access to memory.

ok miod@
---
 sys/arch/riscv64/riscv64/bus_dma.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/arch/riscv64/riscv64/bus_dma.c b/sys/arch/riscv64/riscv64/bus_dma.c
index 08935d266c6..7659eb5be28 100644
--- a/sys/arch/riscv64/riscv64/bus_dma.c
+++ b/sys/arch/riscv64/riscv64/bus_dma.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bus_dma.c,v 1.5 2021/05/14 06:48:52 jsg Exp $	*/
+/*	$OpenBSD: bus_dma.c,v 1.6 2022/12/29 11:30:58 kettenis Exp $	*/
 
 /*
  * Copyright (c) 2003-2004 Opsycon AB  (www.opsycon.se / www.opsycon.com)
@@ -401,7 +401,7 @@ _dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t addr,
 	 * and return.
 	 */
 	if (t->_flags & BUS_DMA_COHERENT) {
-		membar_sync();
+		__asm volatile ("fence iorw,iorw" ::: "memory");
 		return;
 	}
 
-- 
2.20.1