[PATCH 1/2] iommu/mediatek: Convert M4Uv2 to iommu_fwspec

[Robin Murphy]

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 as a simpler alternative to the custom
archdata code.

CC: Yong Wu <yong.wu at mediatek.com>
Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---

These are fairly mechanical cleanups, so I'm pretty confident, but it
still bears mentioning that they're only compile-tested as I don't have
the relevant hardware.

Robin.

 drivers/iommu/mtk_iommu.c | 75 ++++++++++++-----------------------------------
 1 file changed, 18 insertions(+), 57 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index b12c12d74c33..13bb57995cd3 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -195,14 +195,14 @@ 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 = MTK_M4U_TO_LARB(cur->mtk_m4u_id);
-		portid = MTK_M4U_TO_PORT(cur->mtk_m4u_id);
+	for (i = 0; i < fwspec->num_ids; ++i) {
+		larbid = MTK_M4U_TO_LARB(fwspec->ids[i]);
+		portid = MTK_M4U_TO_PORT(fwspec->ids[i]);
 		larb_mmu = &data->smi_imu.larb_imu[larbid];
 
 		dev_dbg(dev, "%s iommu port: %d\n",
@@ -282,14 +282,12 @@ 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);
@@ -310,13 +308,11 @@ 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);
 }
 
@@ -366,8 +362,8 @@ static int mtk_iommu_add_device(struct device *dev)
 {
 	struct iommu_group *group;
 
-	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))
@@ -379,33 +375,21 @@ 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))
@@ -416,7 +400,6 @@ static struct iommu_group *mtk_iommu_device_group(struct device *dev)
 
 static int mtk_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
 {
-	struct mtk_iommu_client_priv *head, *priv, *next;
 	struct platform_device *m4updev;
 
 	if (args->args_count != 1) {
@@ -425,38 +408,16 @@ static int mtk_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
 		return -EINVAL;
 	}
 
-	if (!dev->archdata.iommu) {
+	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)
-		goto err_free_mem;
-
-	priv->mtk_m4u_id = args->args[0];
-	list_add_tail(&priv->client, &head->client);
-
-	return 0;
-
-err_free_mem:
-	list_for_each_entry_safe(priv, next, &head->client, client)
-		kfree(priv);
-	kfree(head);
-	dev->archdata.iommu = NULL;
-	return -ENOMEM;
+	return iommu_fwspec_add_ids(dev, args->args, 1);
 }
 
 static struct iommu_ops mtk_iommu_ops = {
-- 
1.9.1