From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934093Ab3LIQvG (ORCPT ); Mon, 9 Dec 2013 11:51:06 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:17908 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933883Ab3LIQvA (ORCPT ); Mon, 9 Dec 2013 11:51:00 -0500 X-IronPort-AV: E=Sophos;i="4.93,859,1378857600"; d="scan'208";a="80081945" Message-ID: <1386607857.7812.66.camel@kazak.uk.xensource.com> Subject: Re: [PATCH] xen/arm64: do not call the swiotlb functions twice From: Ian Campbell To: Stefano Stabellini CC: , , , , , Date: Mon, 9 Dec 2013 16:50:57 +0000 In-Reply-To: <1386605160-3185-1-git-send-email-stefano.stabellini@eu.citrix.com> References: <1386605160-3185-1-git-send-email-stefano.stabellini@eu.citrix.com> Organization: Citrix Systems, Inc. Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4-3 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.2.80] X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2013-12-09 at 16:06 +0000, Stefano Stabellini wrote: > On arm64 the dma_map_ops implementation is based on the swiotlb. > swiotlb-xen, used by default in dom0 on Xen, is also based on the > swiotlb. > > Avoid calling into the default arm64 dma_map_ops functions from > xen_dma_map_page, xen_dma_unmap_page, xen_dma_sync_single_for_cpu, and > xen_dma_sync_single_for_device otherwise we end up calling into the > swiotlb twice. > > When arm64 gets a non-swiotlb based implementation of dma_map_ops, we'll > probably have to reintroduce dma_map_ops calls in page-coherent.h. > > Signed-off-by: Stefano Stabellini > CC: catalin.marinas@arm.com > CC: Will.Deacon@arm.com Tested-by: Ian Campbell Ian.