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=unavailable 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 D796AC433DF for ; Tue, 23 Jun 2020 11:30:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B337C206C3 for ; Tue, 23 Jun 2020 11:30:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732416AbgFWLaa (ORCPT ); Tue, 23 Jun 2020 07:30:30 -0400 Received: from foss.arm.com ([217.140.110.172]:58868 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732191AbgFWLaV (ORCPT ); Tue, 23 Jun 2020 07:30:21 -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 477CD1F1; Tue, 23 Jun 2020 04:30:20 -0700 (PDT) Received: from [10.57.9.128] (unknown [10.57.9.128]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CB48E3F6CF; Tue, 23 Jun 2020 04:30:17 -0700 (PDT) Subject: Re: [PATCH v6 3/4] iommu/arm-smmu: Add global/context fault implementation hooks To: Thierry Reding , Krishna Reddy Cc: snikam@nvidia.com, mperttunen@nvidia.com, bhuntsman@nvidia.com, will@kernel.org, joro@8bytes.org, linux-kernel@vger.kernel.org, praithatha@nvidia.com, talho@nvidia.com, iommu@lists.linux-foundation.org, nicolinc@nvidia.com, linux-tegra@vger.kernel.org, yhsu@nvidia.com, treding@nvidia.com, linux-arm-kernel@lists.infradead.org, bbiswas@nvidia.com References: <20200604234414.21912-1-vdumpa@nvidia.com> <20200604234414.21912-4-vdumpa@nvidia.com> <20200623083643.GB4098287@ulmo> From: Robin Murphy Message-ID: <2dda4530-39cc-d549-1124-26337dd9afbe@arm.com> Date: Tue, 23 Jun 2020 12:30:16 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200623083643.GB4098287@ulmo> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-06-23 09:36, Thierry Reding wrote: [...] >> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c >> index 243bc4cb2705b..d720e1e191176 100644 >> --- a/drivers/iommu/arm-smmu.c >> +++ b/drivers/iommu/arm-smmu.c >> @@ -673,6 +673,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain, >> enum io_pgtable_fmt fmt; >> struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); >> struct arm_smmu_cfg *cfg = &smmu_domain->cfg; >> + irqreturn_t (*context_fault)(int irq, void *dev); >> >> mutex_lock(&smmu_domain->init_mutex); >> if (smmu_domain->smmu) >> @@ -835,7 +836,9 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain, >> * handler seeing a half-initialised domain state. >> */ >> irq = smmu->irqs[smmu->num_global_irqs + cfg->irptndx]; >> - ret = devm_request_irq(smmu->dev, irq, arm_smmu_context_fault, >> + context_fault = (smmu->impl && smmu->impl->context_fault) ? >> + smmu->impl->context_fault : arm_smmu_context_fault; > > A simpler way might have been to assign arm_smmu_context_fault to all > implementations. That way we wouldn't have to perform this check here > and instead just always using smmu->impl->context_fault. But smmu->impl can still be NULL... Everything in impl, including the presence of impl itself, is optional, so the notion of overriding a default with the same default doesn't really make much sense, and would go against the pattern everywhere else. Robin. >> + ret = devm_request_irq(smmu->dev, irq, context_fault, >> IRQF_SHARED, "arm-smmu-context-fault", domain); >> if (ret < 0) { >> dev_err(smmu->dev, "failed to request context IRQ %d (%u)\n", >> @@ -2107,6 +2110,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev) >> struct arm_smmu_device *smmu; >> struct device *dev = &pdev->dev; >> int num_irqs, i, err; >> + irqreturn_t (*global_fault)(int irq, void *dev); >> >> smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL); >> if (!smmu) { >> @@ -2193,9 +2197,12 @@ static int arm_smmu_device_probe(struct platform_device *pdev) >> smmu->num_context_irqs = smmu->num_context_banks; >> } >> >> + global_fault = (smmu->impl && smmu->impl->global_fault) ? >> + smmu->impl->global_fault : arm_smmu_global_fault; >> + > > Same as above. > > Thierry >