iommu/mediatek: Do no use dev->archdata.iommu

The iommu private pointer is already used in the Mediatek IOMMU v1
driver, so move the dma_iommu_mapping pointer into 'struct
mtk_iommu_data' and do not use dev->archdata.iommu anymore.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20200625130836.1916-9-joro@8bytes.org

drivers/iommu/mtk_iommu.h

@@ -62,6 +62,8 @@ struct mtk_iommu_data {
 	struct iommu_device		iommu;
 	const struct mtk_iommu_plat_data *plat_data;
 
+	struct dma_iommu_mapping	*mapping; /* For mtk_iommu_v1.c */
+
 	struct list_head		list;
 	struct mtk_smi_larb_iommu	larb_imu[MTK_LARB_NR_MAX];
 };

drivers/iommu/mtk_iommu_v1.c

@@ -269,7 +269,7 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
 	int ret;
 
 	/* Only allow the domain created internally. */
-	mtk_mapping = data->dev->archdata.iommu;
+	mtk_mapping = data->mapping;
 	if (mtk_mapping->domain != domain)
 		return 0;
 
@@ -369,7 +369,6 @@ static int mtk_iommu_create_mapping(struct device *dev,
 	struct mtk_iommu_data *data;
 	struct platform_device *m4updev;
 	struct dma_iommu_mapping *mtk_mapping;
-	struct device *m4udev;
 	int ret;
 
 	if (args->args_count != 1) {
@@ -401,8 +400,7 @@ static int mtk_iommu_create_mapping(struct device *dev,
 		return ret;
 
 	data = dev_iommu_priv_get(dev);
-	m4udev = data->dev;
-	mtk_mapping = m4udev->archdata.iommu;
+	mtk_mapping = data->mapping;
 	if (!mtk_mapping) {
 		/* MTK iommu support 4GB iova address space. */
 		mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
@@ -410,7 +408,7 @@ static int mtk_iommu_create_mapping(struct device *dev,
 		if (IS_ERR(mtk_mapping))
 			return PTR_ERR(mtk_mapping);
 
-		m4udev->archdata.iommu = mtk_mapping;
+		data->mapping = mtk_mapping;
 	}
 
 	return 0;
@@ -459,7 +457,7 @@ static void mtk_iommu_probe_finalize(struct device *dev)
 	int err;
 
 	data        = dev_iommu_priv_get(dev);
-	mtk_mapping = data->dev->archdata.iommu;
+	mtk_mapping = data->mapping;
 
 	err = arm_iommu_attach_device(dev, mtk_mapping);
 	if (err)