iommu/mediatek: Convert M4Uv1 to iommu_fwspec

Our per-device data consists of the M4U instance and firmware-provided
list of LARB IDs, which is a perfect fit for the generic iommu_fwspec
machinery. Use that directly instead of the custom archdata code - while
we can't rely on the of_xlate() mechanism to initialise things until the
32-bit ARM DMA code learns about groups and default domains, it still
results in a reasonable simplification overall.

CC: Honghui Zhang <honghui.zhang@mediatek.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Honghui Zhang <honghui.zhang@mediatek.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/mtk_iommu.h

@@ -34,12 +34,6 @@ struct mtk_iommu_suspend_reg {
 	u32				int_main_control;
 };
 
-struct mtk_iommu_client_priv {
-	struct list_head		client;
-	unsigned int			mtk_m4u_id;
-	struct device			*m4udev;
-};
-
 struct mtk_iommu_domain;
 
 struct mtk_iommu_data {

drivers/iommu/mtk_iommu_v1.c

@@ -204,14 +204,14 @@ static irqreturn_t mtk_iommu_isr(int irq, void *dev_id)
 static void mtk_iommu_config(struct mtk_iommu_data *data,
 			     struct device *dev, bool enable)
 {
-	struct mtk_iommu_client_priv *head, *cur, *next;
 	struct mtk_smi_larb_iommu    *larb_mmu;
 	unsigned int                 larbid, portid;
+	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
+	int i;
 
-	head = dev->archdata.iommu;
-	list_for_each_entry_safe(cur, next, &head->client, client) {
-		larbid = mt2701_m4u_to_larb(cur->mtk_m4u_id);
-		portid = mt2701_m4u_to_port(cur->mtk_m4u_id);
+	for (i = 0; i < fwspec->num_ids; ++i) {
+		larbid = mt2701_m4u_to_larb(fwspec->ids[i]);
+		portid = mt2701_m4u_to_port(fwspec->ids[i]);
 		larb_mmu = &data->smi_imu.larb_imu[larbid];
 
 		dev_dbg(dev, "%s iommu port: %d\n",
@@ -271,14 +271,12 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
 				   struct device *dev)
 {
 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
-	struct mtk_iommu_client_priv *priv = dev->archdata.iommu;
-	struct mtk_iommu_data *data;
+	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
 	int ret;
 
-	if (!priv)
+	if (!data)
 		return -ENODEV;
 
-	data = dev_get_drvdata(priv->m4udev);
 	if (!data->m4u_dom) {
 		data->m4u_dom = dom;
 		ret = mtk_iommu_domain_finalise(data);
@@ -295,13 +293,11 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
 static void mtk_iommu_detach_device(struct iommu_domain *domain,
 				    struct device *dev)
 {
-	struct mtk_iommu_client_priv *priv = dev->archdata.iommu;
-	struct mtk_iommu_data *data;
+	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
 
-	if (!priv)
+	if (!data)
 		return;
 
-	data = dev_get_drvdata(priv->m4udev);
 	mtk_iommu_config(data, dev, false);
 }
 
@@ -366,6 +362,8 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
 	return pa;
 }
 
+static struct iommu_ops mtk_iommu_ops;
+
 /*
  * MTK generation one iommu HW only support one iommu domain, and all the client
  * sharing the same iova address space.
@@ -373,7 +371,7 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
 static int mtk_iommu_create_mapping(struct device *dev,
 				    struct of_phandle_args *args)
 {
-	struct mtk_iommu_client_priv *head, *priv, *next;
+	struct mtk_iommu_data *data;
 	struct platform_device *m4updev;
 	struct dma_iommu_mapping *mtk_mapping;
 	struct device *m4udev;
@@ -385,41 +383,37 @@ static int mtk_iommu_create_mapping(struct device *dev,
 		return -EINVAL;
 	}
 
-	if (!dev->archdata.iommu) {
+	if (!dev->iommu_fwspec) {
+		ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_ops);
+		if (ret)
+			return ret;
+	} else if (dev->iommu_fwspec->ops != &mtk_iommu_ops) {
+		return -EINVAL;
+	}
+
+	if (!dev->iommu_fwspec->iommu_priv) {
 		/* Get the m4u device */
 		m4updev = of_find_device_by_node(args->np);
 		if (WARN_ON(!m4updev))
 			return -EINVAL;
 
-		head = kzalloc(sizeof(*head), GFP_KERNEL);
-		if (!head)
-			return -ENOMEM;
-
-		dev->archdata.iommu = head;
-		INIT_LIST_HEAD(&head->client);
-		head->m4udev = &m4updev->dev;
-	} else {
-		head = dev->archdata.iommu;
+		dev->iommu_fwspec->iommu_priv = platform_get_drvdata(m4updev);
 	}
 
-	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
-	if (!priv) {
-		ret = -ENOMEM;
-		goto err_free_mem;
-	}
-	priv->mtk_m4u_id = args->args[0];
-	list_add_tail(&priv->client, &head->client);
+	ret = iommu_fwspec_add_ids(dev, args->args, 1);
+	if (ret)
+		return ret;
 
-	m4udev = head->m4udev;
+	data = dev->iommu_fwspec->iommu_priv;
+	m4udev = data->dev;
 	mtk_mapping = m4udev->archdata.iommu;
 	if (!mtk_mapping) {
 		/* MTK iommu support 4GB iova address space. */
 		mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
 						0, 1ULL << 32);
-		if (IS_ERR(mtk_mapping)) {
-			ret = PTR_ERR(mtk_mapping);
-			goto err_free_mem;
-		}
+		if (IS_ERR(mtk_mapping))
+			return PTR_ERR(mtk_mapping);
+
 		m4udev->archdata.iommu = mtk_mapping;
 	}
 
@@ -432,11 +426,6 @@ static int mtk_iommu_create_mapping(struct device *dev,
 err_release_mapping:
 	arm_iommu_release_mapping(mtk_mapping);
 	m4udev->archdata.iommu = NULL;
-err_free_mem:
-	list_for_each_entry_safe(priv, next, &head->client, client)
-		kfree(priv);
-	kfree(head);
-	dev->archdata.iommu = NULL;
 	return ret;
 }
 
@@ -458,8 +447,8 @@ static int mtk_iommu_add_device(struct device *dev)
 		of_node_put(iommu_spec.np);
 	}
 
-	if (!dev->archdata.iommu) /* Not a iommu client device */
-		return -ENODEV;
+	if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
+		return -ENODEV; /* Not a iommu client device */
 
 	group = iommu_group_get_for_dev(dev);
 	if (IS_ERR(group))
@@ -471,33 +460,21 @@ static int mtk_iommu_add_device(struct device *dev)
 
 static void mtk_iommu_remove_device(struct device *dev)
 {
-	struct mtk_iommu_client_priv *head, *cur, *next;
-
-	head = dev->archdata.iommu;
-	if (!head)
+	if (!dev->iommu_fwspec || dev->iommu_fwspec->ops != &mtk_iommu_ops)
 		return;
 
-	list_for_each_entry_safe(cur, next, &head->client, client) {
-		list_del(&cur->client);
-		kfree(cur);
-	}
-	kfree(head);
-	dev->archdata.iommu = NULL;
-
 	iommu_group_remove_device(dev);
+	iommu_fwspec_free(dev);
 }
 
 static struct iommu_group *mtk_iommu_device_group(struct device *dev)
 {
-	struct mtk_iommu_data *data;
-	struct mtk_iommu_client_priv *priv;
+	struct mtk_iommu_data *data = dev->iommu_fwspec->iommu_priv;
 
-	priv = dev->archdata.iommu;
-	if (!priv)
+	if (!data)
 		return ERR_PTR(-ENODEV);
 
 	/* All the client devices are in the same m4u iommu-group */
-	data = dev_get_drvdata(priv->m4udev);
 	if (!data->m4u_group) {
 		data->m4u_group = iommu_group_alloc();
 		if (IS_ERR(data->m4u_group))