From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752832AbeEKLeN (ORCPT ); Fri, 11 May 2018 07:34:13 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:40354 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752219AbeEKLeL (ORCPT ); Fri, 11 May 2018 07:34:11 -0400 Subject: Re: [PATCH v1 6/9] iommu/tegra: gart: Ignore devices without IOMMU phandle in DT To: Dmitry Osipenko , Joerg Roedel , Thierry Reding , Jonathan Hunter Cc: linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20180508181700.5169-1-digetx@gmail.com> <20180508181700.5169-7-digetx@gmail.com> From: Robin Murphy Message-ID: Date: Fri, 11 May 2018 12:34:08 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180508181700.5169-7-digetx@gmail.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 Hi Dmitry, On 08/05/18 19:16, Dmitry Osipenko wrote: > GART can't handle all devices, ignore devices that aren't related to GART. > Device tree must explicitly assign GART IOMMU to the devices. > > Signed-off-by: Dmitry Osipenko > --- > drivers/iommu/tegra-gart.c | 33 ++++++++++++++++++++++++++++++++- > 1 file changed, 32 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c > index 39305224c48d..5b2d27620350 100644 > --- a/drivers/iommu/tegra-gart.c > +++ b/drivers/iommu/tegra-gart.c > @@ -366,6 +366,26 @@ static void gart_iommu_remove_device(struct device *dev) > iommu_device_unlink(&gart_handle->iommu, dev); > } > > +static int gart_iommu_check_device(struct gart_device *gart, > + struct device *dev); > + > +struct iommu_group *gart_iommu_device_group(struct device *dev) > +{ > + int err; > + > + err = gart_iommu_check_device(gart_handle, dev); > + if (err) > + return ERR_PTR(err); > + > + return generic_device_group(dev); > +} > + > +static int gart_iommu_of_xlate(struct device *dev, > + struct of_phandle_args *args) > +{ > + return 0; > +} > + > static const struct iommu_ops gart_iommu_ops = { > .capable = gart_iommu_capable, > .domain_alloc = gart_iommu_domain_alloc, > @@ -374,14 +394,24 @@ static const struct iommu_ops gart_iommu_ops = { > .detach_dev = gart_iommu_detach_dev, > .add_device = gart_iommu_add_device, > .remove_device = gart_iommu_remove_device, > - .device_group = generic_device_group, > + .device_group = gart_iommu_device_group, > .map = gart_iommu_map, > .map_sg = default_iommu_map_sg, > .unmap = gart_iommu_unmap, > .iova_to_phys = gart_iommu_iova_to_phys, > .pgsize_bitmap = GART_IOMMU_PGSIZES, > + .of_xlate = gart_iommu_of_xlate, > }; > > +static int gart_iommu_check_device(struct gart_device *gart, > + struct device *dev) > +{ > + if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &gart_iommu_ops) > + return -ENODEV; Conceptually, it would be better to verify this in .add_device *before* calling iommu_group_get_for_dev(). That would also align with what other drivers do, and let you save introducing the .device_group callback until the real implementation in the later patch. Robin. > + > + return 0; > +} > + > static int tegra_gart_suspend(struct device *dev) > { > struct gart_device *gart = dev_get_drvdata(dev); > @@ -462,6 +492,7 @@ static int tegra_gart_probe(struct platform_device *pdev) > } > > iommu_device_set_ops(&gart->iommu, &gart_iommu_ops); > + iommu_device_set_fwnode(&gart->iommu, dev->fwnode); > > ret = iommu_device_register(&gart->iommu); > if (ret) { >