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>

2 files changed, 36 insertions, 65 deletions

diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index 3dab13b4a211..f59609f20270 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/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 {
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index b8aeb0768483..884c80cb795e 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/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))