From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966842AbeCALDq (ORCPT ); Thu, 1 Mar 2018 06:03:46 -0500 Received: from foss.arm.com ([217.140.101.70]:36144 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967574AbeCALDl (ORCPT ); Thu, 1 Mar 2018 06:03:41 -0500 Subject: Re: [RESEND PATCH v6 14/14] iommu/rockchip: Support sharing IOMMU between masters 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: <20180301101837.27969-1-jeffy.chen@rock-chips.com> <20180301101837.27969-15-jeffy.chen@rock-chips.com> From: Robin Murphy Message-ID: <44efebd3-ab48-4e12-cf92-66b6563f7644@arm.com> Date: Thu, 1 Mar 2018 11:03:38 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180301101837.27969-15-jeffy.chen@rock-chips.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/03/18 10:18, Jeffy Chen wrote: > There would be some masters sharing the same IOMMU device. Put them in > the same iommu group and share the same iommu domain. > > Signed-off-by: Jeffy Chen > Reviewed-by: Robin Murphy > --- > > Changes in v6: None > Changes in v5: None > Changes in v4: None > Changes in v3: > Remove rk_iommudata->domain. > > Changes in v2: None > > drivers/iommu/rockchip-iommu.c | 22 ++++++++++++++++++++-- > 1 file changed, 20 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c > index 0e0a42f41818..f4ce7706fc34 100644 > --- a/drivers/iommu/rockchip-iommu.c > +++ b/drivers/iommu/rockchip-iommu.c > @@ -104,6 +104,7 @@ struct rk_iommu { > struct iommu_device iommu; > struct list_head node; /* entry in rk_iommu_domain.iommus */ > struct iommu_domain *domain; /* domain to which iommu is attached */ > + struct iommu_group *group; > }; > > struct rk_iommudata { > @@ -1083,6 +1084,15 @@ static void rk_iommu_remove_device(struct device *dev) > iommu_group_remove_device(dev); > } > > +static struct iommu_group *rk_iommu_device_group(struct device *dev) > +{ > + struct rk_iommu *iommu; > + > + iommu = rk_iommu_from_dev(dev); > + > + return iommu->group; Oops, seems I overlooked this in my previous review - it should really be: return iommu_group_get(iommu->group); or the refcounting will be unbalanced on those future systems where it really will be called more than once. Robin. > +} > + > static int rk_iommu_of_xlate(struct device *dev, > struct of_phandle_args *args) > { > @@ -1114,7 +1124,7 @@ static const struct iommu_ops rk_iommu_ops = { > .add_device = rk_iommu_add_device, > .remove_device = rk_iommu_remove_device, > .iova_to_phys = rk_iommu_iova_to_phys, > - .device_group = generic_device_group, > + .device_group = rk_iommu_device_group, > .pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP, > .of_xlate = rk_iommu_of_xlate, > }; > @@ -1183,9 +1193,15 @@ static int rk_iommu_probe(struct platform_device *pdev) > if (err) > return err; > > + iommu->group = iommu_group_alloc(); > + if (IS_ERR(iommu->group)) { > + err = PTR_ERR(iommu->group); > + goto err_unprepare_clocks; > + } > + > err = iommu_device_sysfs_add(&iommu->iommu, dev, NULL, dev_name(dev)); > if (err) > - goto err_unprepare_clocks; > + goto err_put_group; > > iommu_device_set_ops(&iommu->iommu, &rk_iommu_ops); > iommu_device_set_fwnode(&iommu->iommu, &dev->of_node->fwnode); > @@ -1209,6 +1225,8 @@ static int rk_iommu_probe(struct platform_device *pdev) > return 0; > err_remove_sysfs: > iommu_device_sysfs_remove(&iommu->iommu); > +err_put_group: > + iommu_group_put(iommu->group); > err_unprepare_clocks: > clk_bulk_unprepare(iommu->num_clocks, iommu->clocks); > return err; >