iommu: Add sysfs attribyte for domain type

While we could print it at setup time, this is an easier way to match
each device to their default IOMMU allocation type.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/iommu.c

@@ -294,11 +294,39 @@ static ssize_t iommu_group_show_resv_regions(struct iommu_group *group,
 	return (str - buf);
 }
 
+static ssize_t iommu_group_show_type(struct iommu_group *group,
+				     char *buf)
+{
+	char *type = "unknown\n";
+
+	if (group->default_domain) {
+		switch (group->default_domain->type) {
+		case IOMMU_DOMAIN_BLOCKED:
+			type = "blocked\n";
+			break;
+		case IOMMU_DOMAIN_IDENTITY:
+			type = "identity\n";
+			break;
+		case IOMMU_DOMAIN_UNMANAGED:
+			type = "unmanaged\n";
+			break;
+		case IOMMU_DOMAIN_DMA:
+			type = "DMA";
+			break;
+		}
+	}
+	strcpy(buf, type);
+
+	return strlen(type);
+}
+
 static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL);
 
 static IOMMU_GROUP_ATTR(reserved_regions, 0444,
 			iommu_group_show_resv_regions, NULL);
 
+static IOMMU_GROUP_ATTR(type, 0444, iommu_group_show_type, NULL);
+
 static void iommu_group_release(struct kobject *kobj)
 {
 	struct iommu_group *group = to_iommu_group(kobj);
@@ -380,6 +408,10 @@ struct iommu_group *iommu_group_alloc(void)
 	if (ret)
 		return ERR_PTR(ret);
 
+	ret = iommu_group_create_file(group, &iommu_group_attr_type);
+	if (ret)
+		return ERR_PTR(ret);
+
 	pr_debug("Allocated group %d\n", group->id);
 
 	return group;