Re: [PATCH 5/9] iommu: add qcom_iommu

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On Mon, Mar 13, 2017 at 9:38 AM,  <sricharan@xxxxxxxxxxxxxx> wrote:
> Hi Rob,
>
> [..]
>
>
>> +static int qcom_iommu_init_domain(struct iommu_domain *domain,
>> +                                 struct qcom_iommu_dev *qcom_iommu,
>> +                                 struct iommu_fwspec *fwspec)
>> +{
>> +       struct qcom_iommu_domain *qcom_domain =
>> to_qcom_iommu_domain(domain);
>> +       struct io_pgtable_ops *pgtbl_ops;
>> +       struct io_pgtable_cfg pgtbl_cfg;
>> +       int i, ret = 0;
>> +       u32 reg;
>> +
>> +       mutex_lock(&qcom_domain->init_mutex);
>> +       if (qcom_domain->iommu)
>> +               goto out_unlock;
>> +
>> +       pgtbl_cfg = (struct io_pgtable_cfg) {
>> +               .pgsize_bitmap  = qcom_iommu_ops.pgsize_bitmap,
>> +               .ias            = 32,
>> +               .oas            = 40,
>> +               .tlb            = &qcom_gather_ops,
>> +               .iommu_dev      = qcom_iommu->dev,
>> +       };
>> +
>> +       qcom_domain->iommu = qcom_iommu;
>> +       pgtbl_ops = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &pgtbl_cfg,
>> fwspec);
>
>
> So why not pass in the ctx pointer itself
> that we get below as a cookie ? That would basically
> avoid iterating through the list in the tlb_ops ?

The issue is that one domain might be attached to a device with multiple ctx's.

Although perhaps __to_ctx() could be made a bit more clever.  I was
mostly in "make it work, optimize later" mode ;-)

Note also, I'm thinking (both for qcom_iommu and arm-smmu) that we
want to move pgtbl alloc into _domain_alloc().. or at least that would
allow the driver to iommu_map/unmap() before attaching the domain.
(Partly this depends on how the iommu task and/or dynamic domain stuff
works out.. but one way or another we want to be able to map things to
pagetables that aren't the currently attached pagetables)

> [..]
>
>
>> +static int qcom_iommu_add_device(struct device *dev)
>> +{
>> +       struct qcom_iommu_dev *qcom_iommu = __to_iommu(dev->iommu_fwspec);
>> +       struct iommu_group *group;
>> +       struct device_link *link;
>> +
>> +       if (!qcom_iommu)
>> +               return -ENODEV;
>> +
>> +       group = iommu_group_get_for_dev(dev);
>> +       if (IS_ERR_OR_NULL(group))
>> +               return PTR_ERR_OR_ZERO(group);
>> +
>> +       iommu_group_put(group);
>> +       iommu_device_link(&qcom_iommu->iommu, dev);
>> +
>> +       /*
>> +        * Establish the link between iommu and master, so that the
>> +        * iommu gets runtime enabled/disabled as per the master's
>> +        * needs.
>> +        */
>> +       link = device_link_add(dev, qcom_iommu->dev, DL_FLAG_PM_RUNTIME);
>> +       if (!link) {
>> +               dev_warn(qcom_iommu->dev, "Unable to create device link
>> between %s and %s\n",
>> +                        dev_name(qcom_iommu->dev), dev_name(dev));
>> +               /* TODO fatal or ignore? */
>> +       }
>
>
> Yes, should be fatal when depend on master's pm_runtime to call
> the iommu's runtime. The iommu may remain unclocked if the link
> is not there. Might have to fixed in my patch as well.

ok, I've made it -ENODEV

>
>> +
>> +       return 0;
>> +}
>> +
>> +static void qcom_iommu_remove_device(struct device *dev)
>> +{
>> +       struct qcom_iommu_dev *qcom_iommu = __to_iommu(dev->iommu_fwspec);
>> +
>> +       if (!qcom_iommu)
>> +               return;
>> +
>> +       iommu_group_remove_device(dev);
>> +       iommu_device_unlink(&qcom_iommu->iommu, dev);
>> +       iommu_fwspec_free(dev);
>> +}
>> +
>> +static struct iommu_group *qcom_iommu_device_group(struct device *dev)
>> +{
>> +       struct iommu_fwspec *fwspec = dev->iommu_fwspec;
>> +       struct iommu_group *group = NULL;
>> +       unsigned i;
>> +
>> +       for (i = 0; i < fwspec->num_ids; i++) {
>> +               struct qcom_iommu_ctx *ctx = __to_ctx(fwspec,
>> fwspec->ids[i]);
>> +
>> +               if (group && ctx->group && group != ctx->group)
>> +                       return ERR_PTR(-EINVAL);
>> +
>> +               group = ctx->group;
>> +       }
>
>
> I think in this case, the master may devices may not populate the
> same asid/ctx bank more than once intentionally or is this to
> catch accidental wrong DT entry. Just thinking
> if we ever need this logic to get an already existing group in
> our case, simply create a new group always ?

mostly just to catch wrong DT entry.. I don't think we'd need it
anyways.  Perhaps it justifies a WARN_ON()?

>> +
>> +       if (group)
>> +               return iommu_group_ref_get(group);
>> +
>> +       group = generic_device_group(dev);
>> +
>> +       for (i = 0; i < fwspec->num_ids; i++) {
>> +               struct qcom_iommu_ctx *ctx = __to_ctx(fwspec,
>> fwspec->ids[i]);
>> +               ctx->group = iommu_group_ref_get(group);
>> +       }
>> +
>> +       return group;
>> +}
>> +
>> +static int qcom_iommu_of_xlate(struct device *dev, struct of_phandle_args
>> *args)
>> +{
>> +       struct platform_device *iommu_pdev;
>> +
>> +       if (args->args_count != 1) {
>> +               dev_err(dev, "incorrect number of iommu params found for
>> %s "
>> +                       "(found %d, expected 1)\n",
>> +                       args->np->full_name, args->args_count);
>> +               return -EINVAL;
>> +       }
>> +
>> +       if (!dev->iommu_fwspec->iommu_priv) {
>> +               iommu_pdev = of_find_device_by_node(args->np);
>> +               if (WARN_ON(!iommu_pdev))
>> +                       return -EINVAL;
>> +
>> +               dev->iommu_fwspec->iommu_priv =
>> platform_get_drvdata(iommu_pdev);
>> +       }
>> +
>> +       return iommu_fwspec_add_ids(dev, &args->args[0], 1);
>> +}
>> +
>> +static const struct iommu_ops qcom_iommu_ops = {
>> +       .capable        = qcom_iommu_capable,
>> +       .domain_alloc   = qcom_iommu_domain_alloc,
>> +       .domain_free    = qcom_iommu_domain_free,
>> +       .attach_dev     = qcom_iommu_attach_dev,
>> +       .detach_dev     = qcom_iommu_detach_dev,
>> +       .map            = qcom_iommu_map,
>> +       .unmap          = qcom_iommu_unmap,
>> +       .map_sg         = default_iommu_map_sg,
>> +       .iova_to_phys   = qcom_iommu_iova_to_phys,
>> +       .add_device     = qcom_iommu_add_device,
>> +       .remove_device  = qcom_iommu_remove_device,
>> +       .device_group   = qcom_iommu_device_group,
>> +       .of_xlate       = qcom_iommu_of_xlate,
>> +       .pgsize_bitmap  = SZ_4K | SZ_64K | SZ_1M | SZ_16M,
>> +};
>> +
>> +static int qcom_iommu_enable_clocks(struct qcom_iommu_dev *qcom_iommu)
>> +{
>> +       int ret;
>> +
>> +       ret = clk_prepare_enable(qcom_iommu->iface_clk);
>> +       if (ret) {
>> +               dev_err(qcom_iommu->dev, "Couldn't enable iface_clk\n");
>> +               return ret;
>> +       }
>> +
>> +       ret = clk_prepare_enable(qcom_iommu->bus_clk);
>> +       if (ret) {
>> +               dev_err(qcom_iommu->dev, "Couldn't enable bus_clk\n");
>> +               clk_disable_unprepare(qcom_iommu->iface_clk);
>> +               return ret;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static void qcom_iommu_disable_clocks(struct qcom_iommu_dev *qcom_iommu)
>> +{
>> +       clk_disable_unprepare(qcom_iommu->bus_clk);
>> +       clk_disable_unprepare(qcom_iommu->iface_clk);
>> +}
>> +
>> +static int qcom_iommu_ctx_probe(struct platform_device *pdev)
>> +{
>> +       struct qcom_iommu_ctx *ctx;
>> +       struct device *dev = &pdev->dev;
>> +       struct qcom_iommu_dev *qcom_iommu = dev_get_drvdata(dev->parent);
>> +       struct resource *res;
>> +       int ret;
>> +       u32 reg;
>> +
>> +       ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
>> +       if (!ctx) {
>> +               dev_err(dev, "failed to allocate qcom_iommu_context\n");
>> +               return -ENOMEM;
>> +       }
>> +
>> +       ctx->dev = dev;
>> +       platform_set_drvdata(pdev, ctx);
>> +
>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +       ctx->base = devm_ioremap_resource(dev, res);
>> +       if (IS_ERR(ctx->base))
>> +               return PTR_ERR(ctx->base);
>> +
>> +       ctx->irq = platform_get_irq(pdev, 0);
>> +       if (ctx->irq < 0) {
>> +               dev_err(dev, "failed to get irq\n");
>> +               return -ENODEV;
>> +       }
>> +
>> +       ret = devm_request_irq(dev, ctx->irq,
>> +                              qcom_iommu_fault,
>> +                              IRQF_SHARED,
>> +                              "qcom-iommu-fault",
>> +                              ctx);
>> +       if (ret) {
>> +               dev_err(dev, "failed to request IRQ %u\n", ctx->irq);
>> +               return ret;
>> +       }
>> +
>> +       /* read the "reg" property directly to get the relative address
>> +        * of the context bank, and calculate the asid from that:
>> +        */
>> +       if (of_property_read_u32_index(dev->of_node, "reg", 0, &reg)) {
>> +               dev_err(dev, "missing reg property\n");
>> +               return -ENODEV;
>> +       }
>> +
>> +       ctx->asid = reg / 0x1000;
>
>
> hmm, are doing new set of bindings only because of the local_base issue ?

not *just* because of local_base.. actually the bigger reason right
now is so we know which context banks are secure vs not.  I was
thinking that we would later add secure cb support to qcom_iommu.
(But I have really no idea how we'll handle that on arm-smmu for later
devices)

BR,
-R

> Regards,
>  Sricharan
>
>
>
>> +
>> +       dev_info(dev, "found asid %u\n", ctx->asid);
>> +
>> +       list_add_tail(&ctx->node, &qcom_iommu->context_list);
>> +
>> +       return 0;
>> +}
>> +
>> +static int qcom_iommu_ctx_remove(struct platform_device *pdev)
>> +{
>> +       struct qcom_iommu_ctx *ctx = platform_get_drvdata(pdev);
>> +
>> +       if (!ctx)
>> +               return 0;
>> +
>> +       iommu_group_put(ctx->group);
>> +       platform_set_drvdata(pdev, NULL);
>> +
>> +       return 0;
>> +}
>> +
>> +static const struct of_device_id ctx_of_match[] = {
>> +       { .compatible = "qcom,msm-iommu-v1-ns" },
>> +       { .compatible = "qcom,msm-iommu-v1-sec" },
>> +       { /* sentinel */ }
>> +};
>> +
>> +static struct platform_driver qcom_iommu_ctx_driver = {
>> +       .driver = {
>> +               .name           = "qcom-iommu-ctx",
>> +               .of_match_table = of_match_ptr(ctx_of_match),
>> +       },
>> +       .probe  = qcom_iommu_ctx_probe,
>> +       .remove = qcom_iommu_ctx_remove,
>> +};
>> +module_platform_driver(qcom_iommu_ctx_driver);
>> +
>> +static int qcom_iommu_device_probe(struct platform_device *pdev)
>> +{
>> +       struct qcom_iommu_dev *qcom_iommu;
>> +       struct device *dev = &pdev->dev;
>> +       struct resource *res;
>> +       int ret;
>> +
>> +       qcom_iommu = devm_kzalloc(dev, sizeof(*qcom_iommu), GFP_KERNEL);
>> +       if (!qcom_iommu) {
>> +               dev_err(dev, "failed to allocate qcom_iommu_device\n");
>> +               return -ENOMEM;
>> +       }
>> +       qcom_iommu->dev = dev;
>> +
>> +       INIT_LIST_HEAD(&qcom_iommu->context_list);
>> +
>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +       if (res)
>> +               qcom_iommu->local_base = devm_ioremap_resource(dev, res);
>> +
>> +       qcom_iommu->iface_clk = devm_clk_get(dev, "iface_clk");
>> +       if (IS_ERR(qcom_iommu->iface_clk)) {
>> +               dev_err(dev, "failed to get iface_clk\n");
>> +               return PTR_ERR(qcom_iommu->iface_clk);
>> +       }
>> +
>> +       qcom_iommu->bus_clk = devm_clk_get(dev, "bus_clk");
>> +       if (IS_ERR(qcom_iommu->bus_clk)) {
>> +               dev_err(dev, "failed to get bus_clk\n");
>> +               return PTR_ERR(qcom_iommu->bus_clk);
>> +       }
>> +
>> +       if (of_property_read_u32(dev->of_node, "qcom,iommu-secure-id",
>> +                                &qcom_iommu->sec_id)) {
>> +               dev_err(dev, "missing qcom,iommu-secure-id property\n");
>> +               return -ENODEV;
>> +       }
>> +
>> +       platform_set_drvdata(pdev, qcom_iommu);
>> +
>> +       /* register context bank devices, which are child nodes: */
>> +       ret = of_platform_populate(dev->of_node, ctx_of_match, NULL, dev);
>> +       if (ret) {
>> +               dev_err(dev, "Failed to populate iommu contexts\n");
>> +               return ret;
>> +       }
>> +
>> +       ret = iommu_device_sysfs_add(&qcom_iommu->iommu, dev, NULL,
>> +                                    "smmu.%pa", &res->start);
>> +       if (ret) {
>> +               dev_err(dev, "Failed to register iommu in sysfs\n");
>> +               return ret;
>> +       }
>> +
>> +       iommu_device_set_ops(&qcom_iommu->iommu, &qcom_iommu_ops);
>> +       iommu_device_set_fwnode(&qcom_iommu->iommu, dev->fwnode);
>> +
>> +       ret = iommu_device_register(&qcom_iommu->iommu);
>> +       if (ret) {
>> +               dev_err(dev, "Failed to register iommu\n");
>> +               return ret;
>> +       }
>> +
>> +       pm_runtime_enable(dev);
>> +       bus_set_iommu(&platform_bus_type, &qcom_iommu_ops);
>> +
>> +       if (qcom_iommu->local_base) {
>> +               pm_runtime_get_sync(dev);
>> +               writel_relaxed(0xffffffff, qcom_iommu->local_base +
>> SMMU_INTR_SEL_NS);
>> +               pm_runtime_put_sync(dev);
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static int qcom_iommu_device_remove(struct platform_device *pdev)
>> +{
>> +       pm_runtime_force_suspend(&pdev->dev);
>> +       platform_set_drvdata(pdev, NULL);
>> +
>> +       return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM
>> +static int qcom_iommu_resume(struct device *dev)
>> +{
>> +       struct platform_device *pdev = to_platform_device(dev);
>> +       struct qcom_iommu_dev *qcom_iommu = platform_get_drvdata(pdev);
>> +
>> +       return qcom_iommu_enable_clocks(qcom_iommu);
>> +}
>> +
>> +static int qcom_iommu_suspend(struct device *dev)
>> +{
>> +       struct platform_device *pdev = to_platform_device(dev);
>> +       struct qcom_iommu_dev *qcom_iommu = platform_get_drvdata(pdev);
>> +
>> +       qcom_iommu_disable_clocks(qcom_iommu);
>> +
>> +       return 0;
>> +}
>> +#endif
>> +
>> +static const struct dev_pm_ops qcom_iommu_pm_ops = {
>> +       SET_RUNTIME_PM_OPS(qcom_iommu_suspend, qcom_iommu_resume, NULL)
>> +       SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
>> +                               pm_runtime_force_resume)
>> +};
>> +
>> +static const struct of_device_id qcom_iommu_of_match[] = {
>> +       { .compatible = "qcom,msm-iommu-v1" },
>> +       { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, qcom_iommu_of_match);
>> +
>> +static struct platform_driver qcom_iommu_driver = {
>> +       .driver = {
>> +               .name           = "qcom-iommu",
>> +               .of_match_table = of_match_ptr(qcom_iommu_of_match),
>> +               .pm             = &qcom_iommu_pm_ops,
>> +       },
>> +       .probe  = qcom_iommu_device_probe,
>> +       .remove = qcom_iommu_device_remove,
>> +};
>> +module_platform_driver(qcom_iommu_driver);
>> +
>> +IOMMU_OF_DECLARE(qcom_iommu_dev, "qcom,msm-iommu-v1", NULL);
>> +
>> +MODULE_DESCRIPTION("IOMMU API for QCOM IOMMU v1 implementations");
>> +MODULE_LICENSE("GPL v2");
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