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=-4.2 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 1DF60C04EBF for ; Wed, 5 Dec 2018 14:43:14 +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 D5A2120892 for ; Wed, 5 Dec 2018 14:43:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="pwJFqGNP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D5A2120892 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org 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=f/1nlYKZnwuD73vKxsHmeZ+h5yNdSceLiwyqJnr9haY=; b=pwJFqGNPclPP1I 58mRNUYjvGUtpB9+jql7mLZVLkVSWPdHhro35x8CT83DfnRS9zfL/65fuSSBre38ocsjN88d3ua/R VuwNlNW96EqEa3Xs+yETSBA9zEaN7bvAaWIAE83+vTRH2d0mju7WiXH6uk+SdN8hZPveV3XF7M+u7 DdlyEZW8mzNb5CyUe+pGtWE3yFF9w+z4Ggrd0EdrLpe/oI+W8rteeV6dsiWmzXEnXwIF5+NVhItgw 6wVeQFPK4TZHbMC35kbogs971MIZgeK5PLimFUydP1HSZhd4zNrAqgpyBBKAsmJTsCsaDUWnCG2Vo z/JRfwxpB1u/IyX3R3sg==; 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 1gUYON-0007gj-Rk; Wed, 05 Dec 2018 14:43:11 +0000 Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gUYOK-0007gE-O2; Wed, 05 Dec 2018 14:43:08 +0000 Date: Wed, 5 Dec 2018 06:43:08 -0800 From: Christoph Hellwig To: Robin Murphy Subject: Re: [PATCH v4 3/3] iommu/io-pgtable-arm-v7s: Request DMA32 memory, and improve debugging Message-ID: <20181205144308.GA28409@infradead.org> References: <20181205054828.183476-1-drinkcat@chromium.org> <20181205054828.183476-4-drinkcat@chromium.org> <20181205135406.GA29031@infradead.org> <1d211576-9153-cca1-5cd0-8c9881bd3fa4@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1d211576-9153-cca1-5cd0-8c9881bd3fa4@arm.com> User-Agent: Mutt/1.9.2 (2017-12-15) 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: Michal Hocko , Will Deacon , Levin Alexander , linux-mm@kvack.org, Christoph Lameter , Nicolas Boichat , Huaisheng Ye , Joerg Roedel , Matthew Wilcox , Christoph Hellwig , Yong Wu , David Rientjes , yingjoe.chen@mediatek.com, Vlastimil Babka , Tomasz Figa , Mike Rapoport , Matthias Brugger , Joonsoo Kim , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Pekka Enberg , iommu@lists.linux-foundation.org, Andrew Morton , Mel Gorman 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 05, 2018 at 02:40:06PM +0000, Robin Murphy wrote: > 32-bit Arm doesn't have ZONE_DMA32, but has (or at least had at the time) a > 2GB ZONE_DMA. Whether we actually need that or not depends on how this all > interacts with LPAE and highmem, but I'm not sure of those details off-hand. Well, arm32 can't address more than 32-bits in the linear kernel mapping, so GFP_KERNEL should be perfectly fine there if the limit really is 32-bits and not 31 or smaller because someone stole a bit or two somewhere. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel