From owner-svn-src-all@FreeBSD.ORG Sat Nov 15 03:39:59 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 1E8A32BF; Sat, 15 Nov 2014 03:39:59 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 0B921C6B; Sat, 15 Nov 2014 03:39:59 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id sAF3dwau039720; Sat, 15 Nov 2014 03:39:58 GMT (envelope-from ian@FreeBSD.org) Received: (from ian@localhost) by svn.freebsd.org (8.14.9/8.14.9/Submit) id sAF3dwbg039719; Sat, 15 Nov 2014 03:39:58 GMT (envelope-from ian@FreeBSD.org) Message-Id: <201411150339.sAF3dwbg039719@svn.freebsd.org> X-Authentication-Warning: svn.freebsd.org: ian set sender to ian@FreeBSD.org using -f From: Ian Lepore Date: Sat, 15 Nov 2014 03:39:58 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r274538 - head/sys/arm/arm X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 15 Nov 2014 03:39:59 -0000 Author: ian Date: Sat Nov 15 03:39:58 2014 New Revision: 274538 URL: https://svnweb.freebsd.org/changeset/base/274538 Log: When doing busdma sync ops for BUSDMA_COHERENT memory, there is no need for cache maintenance operations, but ensure that all prior writes have reached memory when doing a PREWRITE sync. Submitted by: Michal Meloun Modified: head/sys/arm/arm/busdma_machdep-v6.c Modified: head/sys/arm/arm/busdma_machdep-v6.c ============================================================================== --- head/sys/arm/arm/busdma_machdep-v6.c Sat Nov 15 03:34:34 2014 (r274537) +++ head/sys/arm/arm/busdma_machdep-v6.c Sat Nov 15 03:39:58 2014 (r274538) @@ -1385,8 +1385,18 @@ _bus_dmamap_sync(bus_dma_tag_t dmat, bus dmat->bounce_zone->total_bounced++; } } - if (map->flags & DMAMAP_COHERENT) + + /* + * For COHERENT memory no cache maintenance is necessary, but ensure all + * writes have reached memory for the PREWRITE case. + */ + if (map->flags & DMAMAP_COHERENT) { + if (op & BUS_DMASYNC_PREWRITE) { + dsb(); + cpu_l2cache_drain_writebuf(); + } return; + } if (map->sync_count != 0) { if (!pmap_dmap_iscurrent(map->pmap))