vfio/mtty: Use mdev_get_type_group_id()

The type_group_id directly gives the single or dual port index, no
need for string searching.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJason Gunthorpe <jgg@nvidia.com>
Message-Id: <12-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

samples/vfio-mdev/mtty.c

@@ -711,23 +711,7 @@ static ssize_t mdev_access(struct mdev_device *mdev, u8 *buf, size_t count,
 static int mtty_create(struct kobject *kobj, struct mdev_device *mdev)
 {
 	struct mdev_state *mdev_state;
-	char name[MTTY_STRING_LEN];
-	int nr_ports = 0, i;
-
-	if (!mdev)
-		return -EINVAL;
-
-	for (i = 0; i < 2; i++) {
-		snprintf(name, MTTY_STRING_LEN, "%s-%d",
-			dev_driver_string(mdev_parent_dev(mdev)), i + 1);
-		if (!strcmp(kobj->name, name)) {
-			nr_ports = i + 1;
-			break;
-		}
-	}
-
-	if (!nr_ports)
-		return -EINVAL;
+	int nr_ports = mdev_get_type_group_id(mdev) + 1;
 
 	mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
 	if (mdev_state == NULL)
@@ -1311,18 +1295,11 @@ static const struct attribute_group *mdev_dev_groups[] = {
 static ssize_t
 name_show(struct kobject *kobj, struct device *dev, char *buf)
 {
-	char name[MTTY_STRING_LEN];
-	int i;
-	const char *name_str[2] = {"Single port serial", "Dual port serial"};
+	static const char *name_str[2] = { "Single port serial",
+					   "Dual port serial" };
 
-	for (i = 0; i < 2; i++) {
-		snprintf(name, MTTY_STRING_LEN, "%s-%d",
-			 dev_driver_string(dev), i + 1);
-		if (!strcmp(kobj->name, name))
-			return sprintf(buf, "%s\n", name_str[i]);
-	}
-
-	return -EINVAL;
+	return sysfs_emit(buf, "%s\n",
+			  name_str[mtype_get_type_group_id(kobj)]);
 }
 
 static MDEV_TYPE_ATTR_RO(name);
@@ -1330,22 +1307,9 @@ static MDEV_TYPE_ATTR_RO(name);
 static ssize_t
 available_instances_show(struct kobject *kobj, struct device *dev, char *buf)
 {
-	char name[MTTY_STRING_LEN];
-	int i;
 	struct mdev_state *mds;
-	int ports = 0, used = 0;
-
-	for (i = 0; i < 2; i++) {
-		snprintf(name, MTTY_STRING_LEN, "%s-%d",
-			 dev_driver_string(dev), i + 1);
-		if (!strcmp(kobj->name, name)) {
-			ports = i + 1;
-			break;
-		}
-	}
-
-	if (!ports)
-		return -EINVAL;
+	unsigned int ports = mtype_get_type_group_id(kobj) + 1;
+	int used = 0;
 
 	list_for_each_entry(mds, &mdev_devices_list, next)
 		used += mds->nr_ports;