[RFC PATCH 31/34] iommu/exynos: Create iommu_device in struct exynos_iommu_owner

[Joerg Roedel <joro@xxxxxxxxxx>]

From: Joerg Roedel <jroedel@xxxxxxx>

The 'struct exynos_iommu_owner' is an umbrella for multiple SYSMMU
instances attached to one master. As such all these instances are
handled the same, they are all configured with the same iommu_domain,
for example.

The IOMMU core code expects each device to have only one IOMMU
attached, so create the IOMMU-device for the umbrella instead of each
hardware SYSMMU.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
 drivers/iommu/exynos-iommu.c | 96 +++++++++++++++++++++++++++---------
 1 file changed, 73 insertions(+), 23 deletions(-)

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 186ff5cc975c..86ecccbf0438 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -235,6 +235,8 @@ struct exynos_iommu_owner {
 	struct list_head controllers;	/* list of sysmmu_drvdata.owner_node */
 	struct iommu_domain *domain;	/* domain this device is attached */
 	struct mutex rpm_lock;		/* for runtime pm of all sysmmus */
+
+	struct iommu_device iommu;	/* IOMMU core handle */
 };
 
 /*
@@ -274,8 +276,6 @@ struct sysmmu_drvdata {
 	struct list_head owner_node;	/* node for owner controllers list */
 	phys_addr_t pgtable;		/* assigned page table structure */
 	unsigned int version;		/* our version */
-
-	struct iommu_device iommu;	/* IOMMU core handle */
 };
 
 static struct exynos_iommu_domain *to_exynos_domain(struct iommu_domain *dom)
@@ -625,18 +625,6 @@ static int exynos_sysmmu_probe(struct platform_device *pdev)
 	data->sysmmu = dev;
 	spin_lock_init(&data->lock);
 
-	ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL,
-				     dev_name(data->sysmmu));
-	if (ret)
-		return ret;
-
-	iommu_device_set_ops(&data->iommu, &exynos_iommu_ops);
-	iommu_device_set_fwnode(&data->iommu, &dev->of_node->fwnode);
-
-	ret = iommu_device_register(&data->iommu);
-	if (ret)
-		return ret;
-
 	platform_set_drvdata(pdev, data);
 
 	__sysmmu_get_version(data);
@@ -1261,6 +1249,8 @@ static int exynos_iommu_add_device(struct device *dev)
 	}
 	iommu_group_put(group);
 
+	iommu_device_link(&owner->iommu, dev);
+
 	return 0;
 }
 
@@ -1282,18 +1272,82 @@ static void exynos_iommu_remove_device(struct device *dev)
 			iommu_group_put(group);
 		}
 	}
+	iommu_device_unlink(&owner->iommu, dev);
 	iommu_group_remove_device(dev);
 
 	list_for_each_entry(data, &owner->controllers, owner_node)
 		device_link_del(data->link);
 }
 
+static int exynos_iommu_device_init(struct exynos_iommu_owner *owner)
+{
+	static u32 counter = 0;
+	int ret;
+
+	/*
+	 * Create a virtual IOMMU device. In reality it is an umbrella for a
+	 * number of SYSMMU platform devices, but that also means that any
+	 * master can have more than one real IOMMU device. This drivers handles
+	 * all the real devices for one master synchronously, so they appear as
+	 * one anyway.
+	 */
+	ret = iommu_device_sysfs_add(&owner->iommu, NULL, NULL,
+				     "sysmmu-owner-%d", counter++);
+	if (ret)
+		return ret;
+
+	iommu_device_set_ops(&owner->iommu, &exynos_iommu_ops);
+
+	return 0;
+}
+
+static void exynos_iommu_device_remove(struct exynos_iommu_owner *owner)
+{
+	iommu_device_set_ops(&owner->iommu, NULL);
+	iommu_device_sysfs_remove(&owner->iommu);
+}
+
+static int exynos_owner_init(struct device *dev)
+{
+	struct exynos_iommu_owner *owner = dev->archdata.iommu;
+	int ret;
+
+	if (owner)
+		return 0;
+
+	owner = kzalloc(sizeof(*owner), GFP_KERNEL);
+	if (!owner)
+		return -ENOMEM;
+
+	ret = exynos_iommu_device_init(owner);
+	if (ret)
+		goto out_free_owner;
+
+	ret = iommu_device_register(&owner->iommu);
+	if (ret)
+		goto out_remove_iommu_device;
+
+	INIT_LIST_HEAD(&owner->controllers);
+	mutex_init(&owner->rpm_lock);
+	dev->archdata.iommu = owner;
+
+	return 0;
+
+out_remove_iommu_device:
+	exynos_iommu_device_remove(owner);
+out_free_owner:
+	kfree(owner);
+
+	return ret;
+}
+
 static int exynos_iommu_of_xlate(struct device *dev,
 				 struct of_phandle_args *spec)
 {
-	struct exynos_iommu_owner *owner = dev->archdata.iommu;
 	struct platform_device *sysmmu = of_find_device_by_node(spec->np);
 	struct sysmmu_drvdata *data, *entry;
+	struct exynos_iommu_owner *owner;
+	int ret;
 
 	if (!sysmmu)
 		return -ENODEV;
@@ -1302,15 +1356,11 @@ static int exynos_iommu_of_xlate(struct device *dev,
 	if (!data)
 		return -ENODEV;
 
-	if (!owner) {
-		owner = kzalloc(sizeof(*owner), GFP_KERNEL);
-		if (!owner)
-			return -ENOMEM;
+	ret = exynos_owner_init(dev);
+	if (ret)
+		return ret;
 
-		INIT_LIST_HEAD(&owner->controllers);
-		mutex_init(&owner->rpm_lock);
-		dev->archdata.iommu = owner;
-	}
+	owner = dev->archdata.iommu;
 
 	list_for_each_entry(entry, &owner->controllers, owner_node)
 		if (entry == data)
-- 
2.17.1