On 3/30/2017 7:16 PM, Rob Clark wrote:
On Thu, Mar 30, 2017 at 2:19 AM, Archit Taneja <arch...@codeaurora.org> wrote:
Hi,

On 03/14/2017 08:48 PM, Rob Clark wrote:

An iommu driver for Qualcomm "B" family devices which do not completely
implement the ARM SMMU spec.  These devices have context-bank register
layout that is similar to ARM SMMU, but no global register space (or at
least not one that is accessible).

Signed-off-by: Rob Clark <robdcl...@gmail.com>
Signed-off-by: Stanimir Varbanov <stanimir.varba...@linaro.org>
---
 drivers/iommu/Kconfig         |  10 +
 drivers/iommu/Makefile        |   1 +
 drivers/iommu/arm-smmu-regs.h |   2 +
 drivers/iommu/qcom_iommu.c    | 818
++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 831 insertions(+)
 create mode 100644 drivers/iommu/qcom_iommu.c


<snip>

+
+static int qcom_iommu_add_device(struct device *dev)
+{
+       struct qcom_iommu_dev *qcom_iommu = __to_iommu(dev->iommu_fwspec);


__to_iommu() has a WARN_ON() that gets triggered here for all devices on
the platform bus that aren't backed by our iommu. We should return -ENODEV
for all of them without throwing a warning.

+       struct iommu_group *group;
+       struct device_link *link;
+


We could do something like:

if (fwspec && fwspec->ops == &qcom_iommu_ops)
        qcom_iommu = __to_iommu(fwspec);
else
        qcom_iommu = NULL;

thanks.. I wonder how I wasn't hitting that?

There's an additional commit in your branch which unintentionally
avoids calling add_device() being called for all devs.

https://github.com/freedreno/kernel-msm/commit/e2444266e37a85ad5188a4511ab26cc4b0f85641

Thanks,
Archit

I'll incorporate this (plus small dt bindings doc update) into next
version.. probably won't have time to send until the weekend or next
week

BR,
-R


Thanks,
Archit


+       if (!qcom_iommu)
+               return -ENODEV;
+
+       /*
+        * 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_err(qcom_iommu->dev, "Unable to create device link
between %s and %s\n",
+                       dev_name(qcom_iommu->dev), dev_name(dev));
+               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);
+
+       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;
+       }
+
+       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)
+               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;      /* context banks are 0x1000 apart
*/
+
+       dev_dbg(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);
+
+       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)
+               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");
+       if (IS_ERR(qcom_iommu->iface_clk)) {
+               dev_err(dev, "failed to get iface clock\n");
+               return PTR_ERR(qcom_iommu->iface_clk);
+       }
+
+       qcom_iommu->bus_clk = devm_clk_get(dev, "bus");
+       if (IS_ERR(qcom_iommu->bus_clk)) {
+               dev_err(dev, "failed to get bus clock\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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