[PATCH v8 14/14] iommu/rockchip: Support sharing IOMMU between masters

[Jeffy Chen]

There would be some masters sharing the same IOMMU device. Put them in
the same iommu group and share the same iommu domain.

Signed-off-by: Jeffy Chen <jeffy.chen at rock-chips.com>
Reviewed-by: Robin Murphy <robin.murphy at arm.com>
---

Changes in v8: None
Changes in v7:
Use iommu_group_ref_get to avoid ref leak

Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3:
Remove rk_iommudata->domain.

Changes in v2: None

 drivers/iommu/rockchip-iommu.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 9f6f74689464..5fc8656c60f9 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -104,6 +104,7 @@ struct rk_iommu {
 	struct iommu_device iommu;
 	struct list_head node; /* entry in rk_iommu_domain.iommus */
 	struct iommu_domain *domain; /* domain to which iommu is attached */
+	struct iommu_group *group;
 };
 
 struct rk_iommudata {
@@ -1073,6 +1074,15 @@ static void rk_iommu_remove_device(struct device *dev)
 	iommu_group_remove_device(dev);
 }
 
+static struct iommu_group *rk_iommu_device_group(struct device *dev)
+{
+	struct rk_iommu *iommu;
+
+	iommu = rk_iommu_from_dev(dev);
+
+	return iommu_group_ref_get(iommu->group);
+}
+
 static int rk_iommu_of_xlate(struct device *dev,
 			     struct of_phandle_args *args)
 {
@@ -1104,7 +1114,7 @@ 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,
+	.device_group = rk_iommu_device_group,
 	.pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP,
 	.of_xlate = rk_iommu_of_xlate,
 };
@@ -1173,9 +1183,15 @@ static int rk_iommu_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
+	iommu->group = iommu_group_alloc();
+	if (IS_ERR(iommu->group)) {
+		err = PTR_ERR(iommu->group);
+		goto err_unprepare_clocks;
+	}
+
 	err = iommu_device_sysfs_add(&iommu->iommu, dev, NULL, dev_name(dev));
 	if (err)
-		goto err_unprepare_clocks;
+		goto err_put_group;
 
 	iommu_device_set_ops(&iommu->iommu, &rk_iommu_ops);
 	iommu_device_set_fwnode(&iommu->iommu, &dev->of_node->fwnode);
@@ -1199,6 +1215,8 @@ static int rk_iommu_probe(struct platform_device *pdev)
 	return 0;
 err_remove_sysfs:
 	iommu_device_sysfs_remove(&iommu->iommu);
+err_put_group:
+	iommu_group_put(iommu->group);
 err_unprepare_clocks:
 	clk_bulk_unprepare(iommu->num_clocks, iommu->clocks);
 	return err;
-- 
2.11.0