From patchwork Fri Jan 1 09:39:40 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 7938801 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: X-Original-To: patchwork-linux-sh@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 27014BEEE5 for ; Fri, 1 Jan 2016 09:40:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5642220523 for ; Fri, 1 Jan 2016 09:40:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 69D8620520 for ; Fri, 1 Jan 2016 09:40:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751450AbcAAJjy (ORCPT ); Fri, 1 Jan 2016 04:39:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53442 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751292AbcAAJjv (ORCPT ); Fri, 1 Jan 2016 04:39:51 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id 9D3CD550BA; Fri, 1 Jan 2016 09:39:49 +0000 (UTC) Received: from redhat.com (vpn1-7-173.ams2.redhat.com [10.36.7.173]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id u019des0016184; Fri, 1 Jan 2016 04:39:41 -0500 Date: Fri, 1 Jan 2016 11:39:40 +0200 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Arnd Bergmann , linux-arch@vger.kernel.org, Andrew Cooper , virtualization@lists.linux-foundation.org, Stefano Stabellini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , David Miller , linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, x86@kernel.org, user-mode-linux-devel@lists.sourceforge.net, adi-buildroot-devel@lists.sourceforge.net, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, xen-devel@lists.xenproject.org, Alexander Duyck Subject: [PATCH v2 30/32] virtio_ring: update weak barriers to use __smp_xxx Message-ID: <1451572003-2440-31-git-send-email-mst@redhat.com> References: <1451572003-2440-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1451572003-2440-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP virtio ring uses smp_wmb on SMP and wmb on !SMP, the reason for the later being that it might be talking to another kernel on the same SMP machine. This is exactly what __smp_XXX barriers do, so switch to these instead of homegrown ifdef hacks. Cc: Peter Zijlstra Cc: Alexander Duyck Signed-off-by: Michael S. Tsirkin --- include/linux/virtio_ring.h | 25 ++++--------------------- 1 file changed, 4 insertions(+), 21 deletions(-) diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h index 67e06fe..f3fa55b 100644 --- a/include/linux/virtio_ring.h +++ b/include/linux/virtio_ring.h @@ -12,7 +12,7 @@ * anyone care? * * For virtio_pci on SMP, we don't need to order with respect to MMIO - * accesses through relaxed memory I/O windows, so smp_mb() et al are + * accesses through relaxed memory I/O windows, so virt_mb() et al are * sufficient. * * For using virtio to talk to real devices (eg. other heterogeneous @@ -21,11 +21,10 @@ * actually quite cheap. */ -#ifdef CONFIG_SMP static inline void virtio_mb(bool weak_barriers) { if (weak_barriers) - smp_mb(); + virt_mb(); else mb(); } @@ -33,7 +32,7 @@ static inline void virtio_mb(bool weak_barriers) static inline void virtio_rmb(bool weak_barriers) { if (weak_barriers) - smp_rmb(); + virt_rmb(); else rmb(); } @@ -41,26 +40,10 @@ static inline void virtio_rmb(bool weak_barriers) static inline void virtio_wmb(bool weak_barriers) { if (weak_barriers) - smp_wmb(); + virt_wmb(); else wmb(); } -#else -static inline void virtio_mb(bool weak_barriers) -{ - mb(); -} - -static inline void virtio_rmb(bool weak_barriers) -{ - rmb(); -} - -static inline void virtio_wmb(bool weak_barriers) -{ - wmb(); -} -#endif struct virtio_device; struct virtqueue;