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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 5D1A9C7618B for ; Wed, 24 Jul 2019 13:57:06 +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 357FC21926 for ; Wed, 24 Jul 2019 13:57:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="PwLMi3H+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 357FC21926 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=xQrxWl+uXTs94GmkoHQ32+7FNwO0krRIbVBdMFUYIBo=; b=PwLMi3H+6vRkQm rFNfS0bVKOvHoBw0kTqtfCbOBezABhSzrdqogtKrv1EvFrTlO6jsloC89sm9Y3nNBg++cJhn2aV+X gm7+k0zf4qgKMgHnlSovUWD77AcXpI6QGBuvW+Wg+OMGbEvjgibWqBrep670I6x/pVyKQYDwedaS0 0raJGGrWdWCc3rz4CxyX9i1tYSGSwubDNF7DA/VEf+FzqpNx4p5WrslgabFTP1GmBeTQ1fFOrqSHn EAk9A5CzlXEg7vrfls7hHoxLWAPVOkcy9AqfXPn8OkmPtqSe5gU9xtxGUwXixSoCAGSgUmq8JiCxF Lw40RmmjxqL2un4+Ebhg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hqHlR-0003zT-IW; Wed, 24 Jul 2019 13:57:05 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hqHlO-0003yL-Cn for linux-arm-kernel@lists.infradead.org; Wed, 24 Jul 2019 13:57:04 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 4D0A368B20; Wed, 24 Jul 2019 15:56:57 +0200 (CEST) Date: Wed, 24 Jul 2019 15:56:57 +0200 From: Christoph Hellwig To: Catalin Marinas Subject: Re: [RFC 3/4] dma-direct: add dma_direct_min_mask Message-ID: <20190724135657.GA9075@lst.de> References: <20190717153135.15507-1-nsaenzjulienne@suse.de> <20190717153135.15507-4-nsaenzjulienne@suse.de> <20190718091526.GA25321@lst.de> <13dd1a4f33fcf814545f0d93f18429e853de9eaf.camel@suse.de> <58753252bd7964e3b9e9558b633bd325c4a898a1.camel@suse.de> <20190724135124.GA44864@arrakis.emea.arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190724135124.GA44864@arrakis.emea.arm.com> 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-20190724_065702_580846_3F152B6E X-CRM114-Status: GOOD ( 11.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stefan.wahren@i2se.com, f.fainelli@gmail.com, Robin Murphy , phil@raspberrypi.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Jisheng.Zhang@synaptics.com, mbrugger@suse.com, Nicolas Saenz Julienne , will@kernel.org, Christoph Hellwig , linux-arm-kernel@lists.infradead.org, Marek Szyprowski 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 Archived-At: List-Archive: On Wed, Jul 24, 2019 at 02:51:24PM +0100, Catalin Marinas wrote: > I think it may be better if we have both ZONE_DMA and ZONE_DMA32 on > arm64. ZONE_DMA would be based on the smallest dma-ranges as described > in the DT while DMA32 covers the first naturally aligned 4GB of RAM > (unchanged). When a smaller ZONE_DMA is not needed, it could be expanded > to cover what would normally be ZONE_DMA32 (or could we have ZONE_DMA as > 0-bytes? I don't think GFP_DMA can still allocate memory in this case). > > We'd probably have to define ARCH_ZONE_DMA_BITS for arm64 to something > smaller than 32-bit but sufficient to cover the known platforms like > RPi4 (the current 24 is too small, so maybe 30). AFAICT, > __dma_direct_optimal_gfp_mask() figures out whether GFP_DMA or GFP_DMA32 > should be passed. ARCH_ZONE_DMA_BITS should probably become a variable. That way we can just initialize it to the default 24 bits in kernel/dma/direct.c and allow architectures to override it in their early boot code. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel