Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752881AbeAQMS0 (ORCPT + 1 other); Wed, 17 Jan 2018 07:18:26 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:39688 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752268AbeAQMSZ (ORCPT ); Wed, 17 Jan 2018 07:18:25 -0500 Subject: Re: [PATCH v2 01/13] iommu/rockchip: Request irqs in rk_iommu_probe() To: Jeffy Chen , linux-kernel@vger.kernel.org Cc: jcliang@chromium.org, xxm@rock-chips.com, tfiga@chromium.org, Heiko Stuebner , linux-rockchip@lists.infradead.org, iommu@lists.linux-foundation.org, Joerg Roedel , linux-arm-kernel@lists.infradead.org References: <20180116132540.18939-1-jeffy.chen@rock-chips.com> <20180116132540.18939-2-jeffy.chen@rock-chips.com> From: Robin Murphy Message-ID: <0b341bbd-6823-a041-9cac-e35bdc9e9bdc@arm.com> Date: Wed, 17 Jan 2018 12:18:21 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20180116132540.18939-2-jeffy.chen@rock-chips.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On 16/01/18 13:25, Jeffy Chen wrote: > Suggested-by: Robin Murphy > Signed-off-by: Jeffy Chen > --- > > Changes in v2: None > > drivers/iommu/rockchip-iommu.c | 38 +++++++++++--------------------------- > 1 file changed, 11 insertions(+), 27 deletions(-) > > diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c > index 9d991c2d8767..4a12d4746095 100644 > --- a/drivers/iommu/rockchip-iommu.c > +++ b/drivers/iommu/rockchip-iommu.c > @@ -18,6 +18,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -91,7 +92,6 @@ struct rk_iommu { > void __iomem **bases; > int num_mmu; > int *irq; Nit: irq seems to be redundant now as well. > - int num_irq; > bool reset_disabled; > struct iommu_device iommu; > struct list_head node; /* entry in rk_iommu_domain.iommus */ > @@ -830,13 +830,6 @@ static int rk_iommu_attach_device(struct iommu_domain *domain, > > iommu->domain = domain; > > - for (i = 0; i < iommu->num_irq; i++) { > - ret = devm_request_irq(iommu->dev, iommu->irq[i], rk_iommu_irq, > - IRQF_SHARED, dev_name(dev), iommu); > - if (ret) > - return ret; > - } > - > for (i = 0; i < iommu->num_mmu; i++) { > rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR, > rk_domain->dt_dma); > @@ -885,9 +878,6 @@ static void rk_iommu_detach_device(struct iommu_domain *domain, > } > rk_iommu_disable_stall(iommu); > > - for (i = 0; i < iommu->num_irq; i++) > - devm_free_irq(iommu->dev, iommu->irq[i], iommu); > - > iommu->domain = NULL; > > dev_dbg(dev, "Detached from iommu domain\n"); > @@ -1138,7 +1128,7 @@ static int rk_iommu_probe(struct platform_device *pdev) > struct rk_iommu *iommu; > struct resource *res; > int num_res = pdev->num_resources; > - int err, i; > + int err, i, irq, num_irq; > > iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL); > if (!iommu) > @@ -1165,23 +1155,17 @@ static int rk_iommu_probe(struct platform_device *pdev) > if (iommu->num_mmu == 0) > return PTR_ERR(iommu->bases[0]); > > - iommu->num_irq = platform_irq_count(pdev); > - if (iommu->num_irq < 0) > - return iommu->num_irq; > - if (iommu->num_irq == 0) > - return -ENXIO; > - > - iommu->irq = devm_kcalloc(dev, iommu->num_irq, sizeof(*iommu->irq), > - GFP_KERNEL); > - if (!iommu->irq) > - return -ENOMEM; > - > - for (i = 0; i < iommu->num_irq; i++) { > - iommu->irq[i] = platform_get_irq(pdev, i); > - if (iommu->irq[i] < 0) { > - dev_err(dev, "Failed to get IRQ, %d\n", iommu->irq[i]); > + num_irq = of_irq_count(dev->of_node); To follow up on the other reply, I'm not sure you really need to count the IRQs beforehand at all - you're going to be looping through platform_get_irq() and handling errors anyway, so you may as well just start at 0 and keep going until -ENOENT (or use platform_get_resource() to double-check whether an index should be valid, as we do in arm_smmu). Otherwise, it looks like everything that the IRQ handler needs in the iommu struct (dev, num_mmu and bases) is already initialised by this point, so we should be OK with respect to races. Robin. > + for (i = 0; i < num_irq; i++) { > + irq = platform_get_irq(pdev, i); > + if (irq < 0) { > + dev_err(dev, "Failed to get IRQ, %d\n", irq); > return -ENXIO; > } > + err = devm_request_irq(iommu->dev, irq, rk_iommu_irq, > + IRQF_SHARED, dev_name(dev), iommu); > + if (err) > + return err; > } > > iommu->reset_disabled = device_property_read_bool(dev, >