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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 D3185C19759 for ; Thu, 1 Aug 2019 14:09:35 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 AC76620679 for ; Thu, 1 Aug 2019 14:09:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AC76620679 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id EBA101970; Thu, 1 Aug 2019 14:09:30 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 355EB2397 for ; Thu, 1 Aug 2019 14:08:25 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 989AD5F4 for ; Thu, 1 Aug 2019 14:08:24 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 7FDE168AFE; Thu, 1 Aug 2019 16:08:20 +0200 (CEST) Date: Thu, 1 Aug 2019 16:08:20 +0200 From: Christoph Hellwig To: Nicolas Saenz Julienne Subject: Re: [PATCH 8/8] mm: comment arm64's usage of 'enum zone_type' Message-ID: <20190801140820.GC23435@lst.de> References: <20190731154752.16557-1-nsaenzjulienne@suse.de> <20190731154752.16557-9-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190731154752.16557-9-nsaenzjulienne@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: phill@raspberryi.org, devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, f.fainelli@gmail.com, will@kernel.org, eric@anholt.net, marc.zyngier@arm.com, catalin.marinas@arm.com, frowand.list@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, robh+dt@kernel.org, wahrenst@gmx.net, mbrugger@suse.com, akpm@linux-foundation.org, Robin Murphy , hch@lst.de, linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Wed, Jul 31, 2019 at 05:47:51PM +0200, Nicolas Saenz Julienne wrote: > + * Architecture Limit > + * ---------------------------------- > + * parisc, ia64, sparc, arm64 <4G > + * s390, powerpc <2G > + * arm Various > + * alpha Unlimited or 0-16MB. > * > * i386, x86_64 and multiple other arches > - * <16M. > + * <16M. powerpc is also Various now, arm64 isn't really < 4G, ia64 only uses ZONE_DMA32 these days, and parisc doesn't seem to use neither ZONE_DMA nor ZONE_DMA32. Based on that I'm not sure the list really makes much sense. > */ > ZONE_DMA, > #endif > #ifdef CONFIG_ZONE_DMA32 > /* > - * x86_64 needs two ZONE_DMAs because it supports devices that are > - * only able to do DMA to the lower 16M but also 32 bit devices that > - * can only do DMA areas below 4G. > + * x86_64 and arm64 need two ZONE_DMAs because they support devices > + * that are only able to DMA a fraction of the 32 bit addressable > + * memory area, but also devices that are limited to that whole 32 bit > + * area. > */ > ZONE_DMA32, Maybe just say various architectures instead of mentioning specific ones? Something like "Some 64-bit platforms need.." _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu