Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751773AbaDVNYT (ORCPT ); Tue, 22 Apr 2014 09:24:19 -0400 Received: from mail-yh0-f46.google.com ([209.85.213.46]:46102 "EHLO mail-yh0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751188AbaDVNYM (ORCPT ); Tue, 22 Apr 2014 09:24:12 -0400 MIME-Version: 1.0 In-Reply-To: <20140314141050.c8bedcb66532d277c496796d@samsung.com> References: <20140314141050.c8bedcb66532d277c496796d@samsung.com> From: Shaik Ameer Basha Date: Tue, 22 Apr 2014 18:53:51 +0530 Message-ID: Subject: Re: [PATCH v11 20/27] iommu/exynos: allow having multiple System MMUs for a master H/W To: Cho KyongHo Cc: Linux ARM Kernel , Linux DeviceTree , Linux IOMMU , Linux Kernel , Linux Samsung SOC , Antonios Motakis , Grant Grundler , Joerg Roedel , Kukjin Kim , Prathyush , Rahul Sharma , Sachin Kamat , Sylwester Nawrocki , Tomasz Figa , Varun Sethi Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi KyongHo Cho, On Fri, Mar 14, 2014 at 10:40 AM, Cho KyongHo wrote: > Some master device descriptor like fimc-is which is an abstraction > of very complex H/W may have multiple System MMUs. For those devices, > the design of the link between System MMU and its master H/W is needed > to be reconsidered. > > A link structure, sysmmu_list_data is introduced that provides a link > to master H/W and that has a pointer to the device descriptor of a > System MMU. Given a device descriptor of a master H/W, it is possible > to traverse all System MMUs that must be controlled along with the > master H/W. > > Signed-off-by: Cho KyongHo > --- > drivers/iommu/exynos-iommu.c | 534 ++++++++++++++++++++++++++---------------- > 1 file changed, 333 insertions(+), 201 deletions(-) > > diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c > index 84ba29a..7489343 100644 > --- a/drivers/iommu/exynos-iommu.c > +++ b/drivers/iommu/exynos-iommu.c > @@ -128,6 +128,10 @@ > #define __master_clk_disable(data) __clk_gate_ctrl(data, clk_master, dis) > [snip] > +static int __init __sysmmu_init_master(struct device *dev) > +{ > + int ret; > + int i = 0; > + struct device_node *node; > + > + while ((node = of_parse_phandle(dev->of_node, "mmu-masters", i++))) { > struct platform_device *master = of_find_device_by_node(node); > + struct exynos_iommu_owner *owner; > + struct sysmmu_list_data *list_data; > > if (!master) { > dev_err(dev, "%s: mmu-master '%s' not found\n", > __func__, node->name); > - return -EINVAL; > + ret = -EINVAL; > + goto err; > } > > - if (master->dev.archdata.iommu != NULL) { > - dev_err(dev, "%s: '%s' is master of other MMU\n", > - __func__, node->name); > - return -EINVAL; > + owner = master->dev.archdata.iommu; > + if (!owner) { > + owner = devm_kzalloc(dev, sizeof(*owner), GFP_KERNEL); > + if (!owner) { > + dev_err(dev, > + "%s: Failed to allocate owner structure\n", > + __func__); > + ret = -ENOMEM; > + goto err; > + } > + > + INIT_LIST_HEAD(&owner->mmu_list); > + INIT_LIST_HEAD(&owner->client); > + owner->dev = &master->dev; > + spin_lock_init(&owner->lock); > + > + master->dev.archdata.iommu = owner; > } > > + list_data = devm_kzalloc(dev, sizeof(*list_data), GFP_KERNEL); > + if (!list_data) { > + dev_err(dev, > + "%s: Failed to allocate sysmmu_list_data\n", > + __func__); > + ret = -ENOMEM; > + goto err; > + } > + > + INIT_LIST_HEAD(&list_data->entry); > + list_data->sysmmu = dev; > + > /* > - * archdata.iommu will be initialized with exynos_iommu_client > - * in sysmmu_hook_driver_register(). > + * System MMUs are attached in the order of the presence > + * in device tree > */ > - master->dev.archdata.iommu = dev; > + list_add_tail(&list_data->entry, &owner->mmu_list); > } > > - data->sysmmu = dev; > - rwlock_init(&data->lock); > + return 0; > +err: > + while ((node = of_parse_phandle(dev->of_node, "mmu-masters", i++))) { Don't we need to reinitialize variable 'i' here before using? i = 0; Regards, Shaik Ameer Basha > + struct platform_device *master = of_find_device_by_node(node); > + struct exynos_iommu_owner *owner; > + struct sysmmu_list_data *list_data; > > - platform_set_drvdata(pdev, data); > + if (!master) > + continue; > > - pm_runtime_enable(dev); > - data->runtime_active = !pm_runtime_enabled(dev); > + owner = master->dev.archdata.iommu; > + if (!owner) > + continue; > > - dev_dbg(dev, "Probed and initialized\n"); > - return 0; > + for_each_sysmmu_list(owner->dev, list_data) { > + if (list_data->sysmmu == dev) { > + list_del(&list_data->entry); > + kfree(list_data); > + break; > + } > + } > + } > + > + return ret; > } > [snip] -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/