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=-5.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 97D55C433E0 for ; Thu, 4 Feb 2021 12:01:37 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 8DF3264DD9 for ; Thu, 4 Feb 2021 12:01:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8DF3264DD9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4DWcbK14NJzDwv3 for ; Thu, 4 Feb 2021 23:01:33 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=robin.murphy@arm.com; receiver=) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 4DWcKY4qPQzDwv0 for ; Thu, 4 Feb 2021 22:49:34 +1100 (AEDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E69ABD6E; Thu, 4 Feb 2021 03:49:31 -0800 (PST) Received: from [10.57.49.26] (unknown [10.57.49.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6C76A3F73B; Thu, 4 Feb 2021 03:49:25 -0800 (PST) Subject: Re: [PATCH RFC v1 2/6] swiotlb: convert variables to arrays To: Christoph Hellwig , Dongli Zhang References: <20210203233709.19819-1-dongli.zhang@oracle.com> <20210203233709.19819-3-dongli.zhang@oracle.com> <20210204072947.GA29812@lst.de> From: Robin Murphy Message-ID: Date: Thu, 4 Feb 2021 11:49:23 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210204072947.GA29812@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ulf.hansson@linaro.org, airlied@linux.ie, joonas.lahtinen@linux.intel.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, bhelgaas@google.com, paulus@samba.org, hpa@zytor.com, mingo@kernel.org, m.szyprowski@samsung.com, sstabellini@kernel.org, adrian.hunter@intel.com, x86@kernel.org, joe.jin@oracle.com, peterz@infradead.org, mingo@redhat.com, bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, matthew.auld@intel.com, thomas.lendacky@amd.com, konrad.wilk@oracle.com, intel-gfx@lists.freedesktop.org, jani.nikula@linux.intel.com, bp@alien8.de, rodrigo.vivi@intel.com, nouveau@lists.freedesktop.org, Claire Chang , boris.ostrovsky@oracle.com, chris@chris-wilson.co.uk, jgross@suse.com, tsbogend@alpha.franken.de, linux-mmc@vger.kernel.org, linux-mips@vger.kernel.org, iommu@lists.linux-foundation.org, tglx@linutronix.de, bauerman@linux.ibm.com, daniel@ffwll.ch, akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org, rppt@kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 2021-02-04 07:29, Christoph Hellwig wrote: > On Wed, Feb 03, 2021 at 03:37:05PM -0800, Dongli Zhang wrote: >> This patch converts several swiotlb related variables to arrays, in >> order to maintain stat/status for different swiotlb buffers. Here are >> variables involved: >> >> - io_tlb_start and io_tlb_end >> - io_tlb_nslabs and io_tlb_used >> - io_tlb_list >> - io_tlb_index >> - max_segment >> - io_tlb_orig_addr >> - no_iotlb_memory >> >> There is no functional change and this is to prepare to enable 64-bit >> swiotlb. > > Claire Chang (on Cc) already posted a patch like this a month ago, > which looks much better because it actually uses a struct instead > of all the random variables. Indeed, I skimmed the cover letter and immediately thought that this whole thing is just the restricted DMA pool concept[1] again, only from a slightly different angle. Robin. [1] https://lore.kernel.org/linux-iommu/20210106034124.30560-1-tientzu@chromium.org/