[src/trunk]: src/sys/arch/xen/xen xbdback(4): Membar audit.

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6d77233b0fbb
branches:  trunk
changeset: 373714:6d77233b0fbb
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sat Feb 25 00:33:15 2023 +0000

description:
xbdback(4): Membar audit.

After consuming request slots, must issue xen_wmb notifying the other
side that we've consumed them in RING_FINAL_CHECK_FOR_REQUESTS.

diffstat:

 sys/arch/xen/xen/xbdback_xenbus.c |  5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diffs (26 lines):

diff -r 1b174c4a92de -r 6d77233b0fbb sys/arch/xen/xen/xbdback_xenbus.c
--- a/sys/arch/xen/xen/xbdback_xenbus.c Sat Feb 25 00:33:03 2023 +0000
+++ b/sys/arch/xen/xen/xbdback_xenbus.c Sat Feb 25 00:33:15 2023 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: xbdback_xenbus.c,v 1.101 2022/09/01 15:33:23 bouyer Exp $      */
+/*      $NetBSD: xbdback_xenbus.c,v 1.102 2023/02/25 00:33:15 riastradh Exp $      */
 
 /*
  * Copyright (c) 2006 Manuel Bouyer.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.101 2022/09/01 15:33:23 bouyer Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.102 2023/02/25 00:33:15 riastradh Exp $");
 
 #include <sys/buf.h>
 #include <sys/condvar.h>
@@ -1065,6 +1065,7 @@
 {
        int work_to_do;
 
+       xen_wmb();
        RING_FINAL_CHECK_FOR_REQUESTS(&xbdi->xbdi_ring.ring_n, work_to_do);
        if (work_to_do)
                xbdi->xbdi_cont = xbdback_co_main;