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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AA447C433E0 for ; Fri, 3 Jul 2020 08:24:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D9242070C for ; Fri, 3 Jul 2020 08:24:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725984AbgGCIY2 (ORCPT ); Fri, 3 Jul 2020 04:24:28 -0400 Received: from foss.arm.com ([217.140.110.172]:36410 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725779AbgGCIY1 (ORCPT ); Fri, 3 Jul 2020 04:24:27 -0400 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 6DB4A2F; Fri, 3 Jul 2020 01:24:27 -0700 (PDT) Received: from [10.57.21.32] (unknown [10.57.21.32]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 91FAE3F73C; Fri, 3 Jul 2020 01:24:25 -0700 (PDT) Subject: Re: [PATCH v3 1/4] iommu/arm-smmu: Add SMMU ID2 register fixup hook To: Tomasz Nowicki , will@kernel.org, joro@8bytes.org, gregory.clement@bootlin.com, robh+dt@kernel.org, hannah@marvell.com Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, catalin.marinas@arm.com, nadavh@marvell.com, linux-arm-kernel@lists.infradead.org, mw@semihalf.com References: <20200702201633.22693-1-tn@semihalf.com> <20200702201633.22693-2-tn@semihalf.com> From: Robin Murphy Message-ID: Date: Fri, 3 Jul 2020 09:24:24 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200702201633.22693-2-tn@semihalf.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 2020-07-02 21:16, Tomasz Nowicki wrote: > We already have 'cfg_probe' hook which meant to override and apply > workarounds while probing ID registers. However, 'cfg_probe' is called > at the very end and therefore for some cases fixing up things becomes complex > or requires exporting of SMMU driver structures. Hence, seems it is better and > cleaner to do ID fixup right away. In preparation for adding Marvell > errata add an extra ID2 fixup hook. Hmm, the intent of ->cfg_probe was very much to give impl a chance to adjust the detected features before we start consuming them, with this exact case in mind. Since the Cavium quirk isn't actually doing that - it just needs to run *anywhere* in the whole probe process - I'm under no illusion that I put the hook in exactly the right place first time around ;) The diff below should be more on the mark... Robin. ----->8----- diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 243bc4cb2705..884ffca5b1eb 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1891,6 +1891,9 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) smmu->features |= ARM_SMMU_FEAT_FMT_AARCH64_64K; } + if (smmu->impl && smmu->impl->cfg_probe) + return smmu->impl->cfg_probe(smmu); + /* Now we've corralled the various formats, what'll it do? */ if (smmu->features & ARM_SMMU_FEAT_FMT_AARCH32_S) smmu->pgsize_bitmap |= SZ_4K | SZ_64K | SZ_1M | SZ_16M; @@ -1909,7 +1912,6 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) dev_notice(smmu->dev, "\tSupported page sizes: 0x%08lx\n", smmu->pgsize_bitmap); - if (smmu->features & ARM_SMMU_FEAT_TRANS_S1) dev_notice(smmu->dev, "\tStage-1: %lu-bit VA -> %lu-bit IPA\n", smmu->va_size, smmu->ipa_size); @@ -1918,9 +1920,6 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu) dev_notice(smmu->dev, "\tStage-2: %lu-bit IPA -> %lu-bit PA\n", smmu->ipa_size, smmu->pa_size); - if (smmu->impl && smmu->impl->cfg_probe) - return smmu->impl->cfg_probe(smmu); - return 0; }