From patchwork Mon Feb 8 16:02:06 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Campbell X-Patchwork-Id: 8251631 Return-Path: X-Original-To: patchwork-xen-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 09FC99F319 for ; Mon, 8 Feb 2016 16:06:41 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7DF44202EC for ; Mon, 8 Feb 2016 16:06:38 +0000 (UTC) Received: from lists.xen.org (lists.xenproject.org [50.57.142.19]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6455820254 for ; Mon, 8 Feb 2016 16:06:37 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aSoGX-0000M9-Rj; Mon, 08 Feb 2016 16:02:17 +0000 Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aSoGV-0000Lz-UO for xen-devel@lists.xenproject.org; Mon, 08 Feb 2016 16:02:16 +0000 Received: from [193.109.254.147] by server-8.bemta-14.messagelabs.com id B3/1D-24450-70CB8B65; Mon, 08 Feb 2016 16:02:15 +0000 X-Env-Sender: prvs=839b4a21d=Ian.Campbell@citrix.com X-Msg-Ref: server-13.tower-27.messagelabs.com!1454947333!22315114!1 X-Originating-IP: [66.165.176.63] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogNjYuMTY1LjE3Ni42MyA9PiAzMDYwNDg=\n, received_headers: No Received headers X-StarScan-Received: X-StarScan-Version: 7.35.1; banners=-,-,- X-VirusChecked: Checked Received: (qmail 32277 invoked from network); 8 Feb 2016 16:02:14 -0000 Received: from smtp02.citrix.com (HELO SMTP02.CITRIX.COM) (66.165.176.63) by server-13.tower-27.messagelabs.com with RC4-SHA encrypted SMTP; 8 Feb 2016 16:02:14 -0000 X-IronPort-AV: E=Sophos;i="5.22,416,1449532800"; d="scan'208";a="336784303" From: Ian Campbell To: Stefano Stabellini Date: Mon, 8 Feb 2016 16:02:06 +0000 Message-ID: <1454947330-29993-1-git-send-email-ian.campbell@citrix.com> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 X-DLP: MIA1 Cc: Russell King , Ian Campbell , Catalin Marinas , Will Deacon , xen-devel@lists.xenproject.org, linux-arm-kernel@lists.infradead.org Subject: [Xen-devel] [PATCH v2] xen/arm: correctly handle DMA mapping of compound pages X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 Currently xen_dma_map_page concludes that DMA to anything other than the head page of a compound page must be foreign, since the PFN of the page is that of the head. Fix the check to instead consider the whole of a compound page to be local if the PFN of the head passes the 1:1 check. We can never see a compound page which is a mixture of foreign and local sub-pages. The comment already correctly described the intention, but fixup the spelling and some grammar. This fixes the various SSH protocol errors which we have been seeing on the cubietrucks in our automated test infrastructure. This has been broken since commit 3567258d281b ("xen/arm: use hypercall to flush caches in map_page"), which was in v3.19-rc1. NB arch/arm64/.../xen/page-coherent.h also includes this file. Signed-off-by: Ian Campbell Cc: xen-devel@lists.xenproject.org Cc: linux-arm-kernel@lists.infradead.org Cc: stable@vger.kernel.org # v3.19+ Reviewed-by: Stefano Stabellini --- v2: Placate checkpatch Handle 64K pages Add some ()s --- arch/arm/include/asm/xen/page-coherent.h | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h index 0375c8c..9408a99 100644 --- a/arch/arm/include/asm/xen/page-coherent.h +++ b/arch/arm/include/asm/xen/page-coherent.h @@ -35,14 +35,21 @@ static inline void xen_dma_map_page(struct device *hwdev, struct page *page, dma_addr_t dev_addr, unsigned long offset, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs) { - bool local = XEN_PFN_DOWN(dev_addr) == page_to_xen_pfn(page); + unsigned long page_pfn = page_to_xen_pfn(page); + unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr); + unsigned long compound_pages = + (1<map_page(hwdev, page, offset, size, dir, attrs);