[PATCH v2 11/13] iommu/rockchip: Use OF_IOMMU to attach devices automatically

Jeffy Chen
2018-01-16T13:25:38Z

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>
---

Changes in v2: None

drivers/iommu/rockchip-iommu.c | 116 +++++++++++------------------------------
1 file changed, 31 insertions(+), 85 deletions(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 51e4f982c4a6..c2d3ac82184e 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_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
@@ -874,18 +875,7 @@ 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;
-
- 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 dev->archdata.iommu;
}

static void rk_iommu_detach_device(struct iommu_domain *domain,
@@ -1065,74 +1055,22 @@ 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)
-{
- struct device_node *np = dev->of_node;
- struct platform_device *pd;
- int ret;
- struct of_phandle_args args;
-
- /*
- * 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;
- }
-
- 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;
- }
-
- /* TODO(djkurtz): handle multiple slave iommus for a single master */
- iommu_group_set_iommudata(group, &pd->dev, NULL);
-
- return 0;
-}
-
static int rk_iommu_add_device(struct device *dev)
{
struct iommu_group *group;
struct rk_iommu *iommu;

- if (!rk_iommu_is_dev_iommu_master(dev))
+ iommu = rk_iommu_from_dev(dev);
+ if (!iommu)
return -ENODEV;

group = iommu_group_get_for_dev(dev);
if (IS_ERR(group))
return PTR_ERR(group);
+ iommu_group_put(group);

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

- iommu_group_put(group);
return 0;
}

@@ -1140,37 +1078,40 @@ static void rk_iommu_remove_device(struct device *dev)
{
struct rk_iommu *iommu;

- if (!rk_iommu_is_dev_iommu_master(dev))
- return;
-
iommu = rk_iommu_from_dev(dev);
- if (iommu)
- iommu_device_unlink(&iommu->iommu, dev);
+ if (!iommu)
+ return;

+ iommu_device_unlink(&iommu->iommu, dev);
iommu_group_remove_device(dev);
}

static struct iommu_group *rk_iommu_device_group(struct device *dev)
{
struct iommu_group *group;
- int ret;

group = iommu_group_get(dev);
- if (!group) {
+ if (!group)
group = iommu_group_alloc();
- if (IS_ERR(group))
- return group;
- }
-
- ret = rk_iommu_group_set_iommudata(group, dev);
- if (ret)
- goto err_put_group;

return group;
+}

-err_put_group:
- iommu_group_put(group);
- return ERR_PTR(ret);
+static int rk_iommu_of_xlate(struct device *dev,
+ struct of_phandle_args *args)
+{
+ struct platform_device *iommu_dev;
+
+ iommu_dev = of_find_device_by_node(args->np);
+ if (!iommu_dev) {
+ dev_err(dev, "iommu %pOF not found\n", args->np);
+ return -ENODEV;
+ }
+
+ dev->archdata.iommu = platform_get_drvdata(iommu_dev);
+ of_dev_put(iommu_dev);
+
+ return 0;
}

static const struct iommu_ops rk_iommu_ops = {
@@ -1186,6 +1127,7 @@ static const struct iommu_ops rk_iommu_ops = {
.iova_to_phys = rk_iommu_iova_to_phys,
.device_group = rk_iommu_device_group,
.pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP,
+ .of_xlate = rk_iommu_of_xlate,
};

static int rk_iommu_probe(struct platform_device *pdev)
@@ -1246,6 +1188,8 @@ static int rk_iommu_probe(struct platform_device *pdev)
goto err_put_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;
@@ -1307,6 +1251,8 @@ static void __exit rk_iommu_exit(void)
subsys_initcall(rk_iommu_init);
module_exit(rk_iommu_exit);

+IOMMU_OF_DECLARE(rk_iommu_of, "rockchip,iommu", NULL);
+
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