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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 B17FFC04EB8 for ; Wed, 12 Dec 2018 07:37:27 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 78AC320851 for ; Wed, 12 Dec 2018 07:37:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ijG7og9A" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 78AC320851 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-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uxafGQZJ7oxq/4JFU/Vn/rvYJLSvK49NoGv+70Nz/Zk=; b=ijG7og9Aw12wEE LlDgYoiLU7n7r1JgMI8ZUa15GznLUSywzA139lXVhz69unxLTDOqr0Kc+23kQZkSkuV2BBpu4Vogf pUjWpRqh7gZL+iIrjvfWRmZQ657K//bcF5qg4xerQBzERLaDCufVkE6UEGKT02UZko5ob93AK13uG uBWfeya9mbusi8cCn4pW463lu6k9rYgdQrYqrZt0gN7uDL/n8axTllGAqipOcbSDXJWSaFhJCRPLk XWRNxpyPYjDnkvXsW7QsZ2eIwkIRKbwt+odRa0nfE9wbvTVq4bAx7oetOcRqRww0ksDiEL3qTLf+I xAFR7NhGnfHO7rEXgNEw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gWz54-0006at-RO; Wed, 12 Dec 2018 07:37:18 +0000 Received: from verein.lst.de ([213.95.11.211] helo=newverein.lst.de) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gWz51-0006Xs-C6 for linux-arm-kernel@lists.infradead.org; Wed, 12 Dec 2018 07:37:16 +0000 Received: by newverein.lst.de (Postfix, from userid 2407) id DD30068D8D; Wed, 12 Dec 2018 08:37:03 +0100 (CET) Date: Wed, 12 Dec 2018 08:37:03 +0100 From: Christoph Hellwig To: Chintan Pandya Subject: Re: [PATCH] arm64: dma-mapping: Fix FORCE_CONTIGUOUS buffer clearing Message-ID: <20181212073703.GA29091@lst.de> References: <9bd208e9187db7a934428fe44ae0906028a8c9c3.1544469820.git.robin.murphy@arm.com> <9f6d3b29-7ca6-c78f-c4b6-f10dd318b1d9@codeaurora.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <9f6d3b29-7ca6-c78f-c4b6-f10dd318b1d9@codeaurora.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181211_233715_560724_08A20D4E X-CRM114-Status: UNSURE ( 7.72 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: catalin.marinas@arm.com, will.deacon@arm.com, Robin Murphy , hch@lst.de, linux-arm-kernel@lists.infradead.org, m.szyprowski@samsung.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Dec 12, 2018 at 01:01:41PM +0530, Chintan Pandya wrote: >> if (addr) { >> - memset(addr, 0, size); >> if (!coherent) >> __dma_flush_area(page_to_virt(page), iosize); >> + memset(addr, 0, size); > > For coherent case, we still skip flushing/invalidating dirty kernel > mappings. Isn't it a problem ? For the dma coherent case there is no need to writeback and/or invalidate the kernel mapping. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel