iommu/exynos: Use first SYSMMU in controllers list for IOMMU core

On Exynos platforms there can be more than one SYSMMU (IOMMU) for one
DMA master device. Since the IOMMU core code expects only one hardware
IOMMU, use the first SYSMMU in the list.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20200429133712.31431-31-joro@8bytes.orgSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/exynos-iommu.c

@@ -1261,6 +1261,11 @@ static int exynos_iommu_add_device(struct device *dev)
 	}
 	iommu_group_put(group);
 
+	/* There is always at least one entry, see exynos_iommu_of_xlate() */
+	data = list_first_entry(&owner->controllers,
+				struct sysmmu_drvdata, owner_node);
+	iommu_device_link(&data->iommu, dev);
+
 	return 0;
 }
 
@@ -1286,6 +1291,11 @@ static void exynos_iommu_remove_device(struct device *dev)
 
 	list_for_each_entry(data, &owner->controllers, owner_node)
 		device_link_del(data->link);
+
+	/* There is always at least one entry, see exynos_iommu_of_xlate() */
+	data = list_first_entry(&owner->controllers,
+				struct sysmmu_drvdata, owner_node);
+	iommu_device_unlink(&data->iommu, dev);
 }
 
 static int exynos_iommu_of_xlate(struct device *dev,