[PATCH v8 11/14] iommu/rockchip: Use OF_IOMMU to attach devices automatically

Jeffy Chen
2018-03-23T07:38:11Z

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 <jeffy.chen-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Reviewed-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
---

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(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 7970d21b9858..bd8580b897e9 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -19,6 +19,7 @@
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_iommu.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
@@ -104,6 +105,10 @@ struct rk_iommu {
struct iommu_domain *domain; /* domain to which iommu is attached */
};

+struct rk_iommudata {
+ struct rk_iommu *iommu;
+};
+
static struct device *dma_dev;

static inline void rk_table_flush(struct rk_iommu_domain *dom, dma_addr_t dma,
@@ -807,18 +812,9 @@ static size_t rk_iommu_unmap(struct iommu_domain *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;
}

static int rk_iommu_attach_device(struct iommu_domain *domain,
@@ -989,110 +985,53 @@ static void rk_iommu_domain_free(struct 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;
}

static const struct iommu_ops rk_iommu_ops = {
@@ -1106,7 +1045,9 @@ 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,
.pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP,
+ .of_xlate = rk_iommu_of_xlate,
};

static int rk_iommu_probe(struct platform_device *pdev)
@@ -1178,6 +1119,8 @@ static int rk_iommu_probe(struct platform_device *pdev)
goto err_unprepare_clocks;

iommu_device_set_ops(&iommu->iommu, &rk_iommu_ops);
+ iommu_device_set_fwnode(&iommu->iommu, &dev->of_node->fwnode);
+
err = iommu_device_register(&iommu->iommu);
if (err)
goto err_remove_sysfs;
@@ -1250,6 +1193,8 @@ static int __init rk_iommu_init(void)
}
subsys_initcall(rk_iommu_init);

+IOMMU_OF_DECLARE(rk_iommu_of, "rockchip,iommu");
+
MODULE_DESCRIPTION("IOMMU API for Rockchip");
MODULE_AUTHOR("Simon Xue <xxm-TNX95d0MmH7DzftRWevZcw@public.gmane.org> and Daniel Kurtz <djkurtz-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>");
MODULE_ALIAS("platform:rockchip-iommu");
--
2.11.0