From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9C27C4161D for ; Tue, 20 Nov 2018 16:08:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 637A520831 for ; Tue, 20 Nov 2018 16:07:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 637A520831 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726914AbeKUChr (ORCPT ); Tue, 20 Nov 2018 21:37:47 -0500 Received: from verein.lst.de ([213.95.11.211]:46087 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725887AbeKUChq (ORCPT ); Tue, 20 Nov 2018 21:37:46 -0500 Received: by newverein.lst.de (Postfix, from userid 2407) id C597D68BDF; Tue, 20 Nov 2018 17:07:53 +0100 (CET) Date: Tue, 20 Nov 2018 17:07:53 +0100 From: Christoph Hellwig To: Robin Murphy Cc: hch@lst.de, konrad.wilk@oracle.com, m.szyprowski@samsung.com, john.stultz@linaro.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] swiotlb: Skip cache maintenance on map error Message-ID: <20181120160753.GB2492@lst.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 20, 2018 at 02:09:53PM +0000, Robin Murphy wrote: > If swiotlb_bounce_page() failed, calling arch_sync_dma_for_device() may > lead to such delights as performing cache maintenance on whatever > address phys_to_virt(SWIOTLB_MAP_ERROR) looks like, which is typically > outside the kernel memory map and goes about as well as expected. > > Don't do that. > > Fixes: a4a4330db46a ("swiotlb: add support for non-coherent DMA") > Signed-off-by: Robin Murphy Looks good, Reviewed-by: Christoph Hellwig