On Fri, Mar 23, 2018 at 1:40 AM Jeffy Chen [off-list ref]
wrote:

Converts the rockchip-iommu driver to use the OF_IOMMU infrastructure,
which allows attaching master devices to their IOMMUs automatically
according to DT properties.

Signed-off-by: Jeffy Chen <redacted>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---

Changes in v8: None
Changes in v7: None
Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3:
Add struct rk_iommudata.
Squash iommu/rockchip: Use iommu_group_get_for_dev() for add_device

Changes in v2: None

  drivers/iommu/rockchip-iommu.c | 135

++++++++++++-----------------------------

  1 file changed, 40 insertions(+), 95 deletions(-)

b/drivers/iommu/rockchip-iommu.c

*/

  };

+struct rk_iommudata {
+       struct rk_iommu *iommu;
+};

Why do we need this struct?  Can't we just assign a pointer to struct
rk_iommu directly to dev->archdata.iommu?

+
  static struct device *dma_dev;

  static inline void rk_table_flush(struct rk_iommu_domain *dom,

dma_addr_t dma,

*domain, unsigned long _iova,

  static struct rk_iommu *rk_iommu_from_dev(struct device *dev)
  {
-       struct iommu_group *group;
-       struct device *iommu_dev;
-       struct rk_iommu *rk_iommu;
+       struct rk_iommudata *data = dev->archdata.iommu;

-       group = iommu_group_get(dev);
-       if (!group)
-               return NULL;
-       iommu_dev = iommu_group_get_iommudata(group);
-       rk_iommu = dev_get_drvdata(iommu_dev);
-       iommu_group_put(group);
-
-       return rk_iommu;
+       return data ? data->iommu : NULL;
  }

iommu_domain *domain)

                 iommu_put_dma_cookie(&rk_domain->domain);
  }

-static bool rk_iommu_is_dev_iommu_master(struct device *dev)
-{
-       struct device_node *np = dev->of_node;
-       int ret;
-
-       /*
-        * An iommu master has an iommus property containing a list of

phandles

-        * to iommu nodes, each with an #iommu-cells property with value

0.

-        */
-       ret = of_count_phandle_with_args(np, "iommus", "#iommu-cells");
-       return (ret > 0);
-}
-
-static int rk_iommu_group_set_iommudata(struct iommu_group *group,
-                                       struct device *dev)
+static int rk_iommu_add_device(struct device *dev)
  {
-       struct device_node *np = dev->of_node;
-       struct platform_device *pd;
-       int ret;
-       struct of_phandle_args args;
+       struct iommu_group *group;
+       struct rk_iommu *iommu;

-       /*
-        * An iommu master has an iommus property containing a list of

phandles

-        * to iommu nodes, each with an #iommu-cells property with value

0.

-        */
-       ret = of_parse_phandle_with_args(np, "iommus", "#iommu-cells", 0,
-                                        &args);
-       if (ret) {
-               dev_err(dev, "of_parse_phandle_with_args(%pOF) => %d\n",
-                       np, ret);
-               return ret;
-       }
-       if (args.args_count != 0) {
-               dev_err(dev, "incorrect number of iommu params found for

%pOF (found %d, expected 0)\n",

-                       args.np, args.args_count);
-               return -EINVAL;
-       }
+       iommu = rk_iommu_from_dev(dev);
+       if (!iommu)
+               return -ENODEV;

-       pd = of_find_device_by_node(args.np);
-       of_node_put(args.np);
-       if (!pd) {
-               dev_err(dev, "iommu %pOF not found\n", args.np);
-               return -EPROBE_DEFER;
-       }
+       group = iommu_group_get_for_dev(dev);
+       if (IS_ERR(group))
+               return PTR_ERR(group);
+       iommu_group_put(group);

-       /* TODO(djkurtz): handle multiple slave iommus for a single

master */

-       iommu_group_set_iommudata(group, &pd->dev, NULL);
+       iommu_device_link(&iommu->iommu, dev);

         return 0;
  }

-static int rk_iommu_add_device(struct device *dev)
+static void rk_iommu_remove_device(struct device *dev)
  {
-       struct iommu_group *group;
         struct rk_iommu *iommu;
-       int ret;
-
-       if (!rk_iommu_is_dev_iommu_master(dev))
-               return -ENODEV;
-
-       group = iommu_group_get(dev);
-       if (!group) {
-               group = iommu_group_alloc();
-               if (IS_ERR(group)) {
-                       dev_err(dev, "Failed to allocate IOMMU group\n");
-                       return PTR_ERR(group);
-               }
-       }
-
-       ret = iommu_group_add_device(group, dev);
-       if (ret)
-               goto err_put_group;
-
-       ret = rk_iommu_group_set_iommudata(group, dev);
-       if (ret)
-               goto err_remove_device;

         iommu = rk_iommu_from_dev(dev);
-       if (iommu)
-               iommu_device_link(&iommu->iommu, dev);

-       iommu_group_put(group);
-
-       return 0;
-
-err_remove_device:
+       iommu_device_unlink(&iommu->iommu, dev);
         iommu_group_remove_device(dev);
-err_put_group:
-       iommu_group_put(group);
-       return ret;
  }

-static void rk_iommu_remove_device(struct device *dev)
+static int rk_iommu_of_xlate(struct device *dev,
+                            struct of_phandle_args *args)
  {
-       struct rk_iommu *iommu;
+       struct platform_device *iommu_dev;
+       struct rk_iommudata *data;

-       if (!rk_iommu_is_dev_iommu_master(dev))
-               return;
+       data = devm_kzalloc(dma_dev, sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;

-       iommu = rk_iommu_from_dev(dev);
-       if (iommu)
-               iommu_device_unlink(&iommu->iommu, dev);
+       iommu_dev = of_find_device_by_node(args->np);

-       iommu_group_remove_device(dev);
+       data->iommu = platform_get_drvdata(iommu_dev);
+       dev->archdata.iommu = data;
+
+       of_dev_put(iommu_dev);
+
+       return 0;
  }

*pdev)

                 goto err_unprepare_clocks;

+IOMMU_OF_DECLARE(rk_iommu_of, "rockchip,iommu");
+
  MODULE_DESCRIPTION("IOMMU API for Rockchip");
  MODULE_AUTHOR("Simon Xue [off-list ref] and Daniel Kurtz <

djkurtz@chromium.org>");

  MODULE_ALIAS("platform:rockchip-iommu");
--
2.11.0