swim3: use blk_mq_alloc_disk

Use the blk_mq_alloc_disk API to simplify the gendisk and request_queue
allocation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/swim3.c

@@ -1202,30 +1202,27 @@ static int swim3_attach(struct macio_dev *mdev,
 			return rc;
 	}
 
-	disk = alloc_disk(1);
-	if (disk == NULL) {
-		rc = -ENOMEM;
-		goto out_unregister;
-	}
-
 	fs = &floppy_states[floppy_count];
 	memset(fs, 0, sizeof(*fs));
 
-	disk->queue = blk_mq_init_sq_queue(&fs->tag_set, &swim3_mq_ops, 2,
-						BLK_MQ_F_SHOULD_MERGE);
-	if (IS_ERR(disk->queue)) {
-		rc = PTR_ERR(disk->queue);
-		disk->queue = NULL;
-		goto out_put_disk;
+	rc = blk_mq_alloc_sq_tag_set(&fs->tag_set, &swim3_mq_ops, 2,
+			BLK_MQ_F_SHOULD_MERGE);
+	if (rc)
+		goto out_unregister;
+
+	disk = blk_mq_alloc_disk(&fs->tag_set, fs);
+	if (IS_ERR(disk)) {
+		rc = PTR_ERR(disk);
+		goto out_free_tag_set;
 	}
-	disk->queue->queuedata = fs;
 
 	rc = swim3_add_device(mdev, floppy_count);
 	if (rc)
-		goto out_cleanup_queue;
+		goto out_cleanup_disk;
 
 	disk->major = FLOPPY_MAJOR;
 	disk->first_minor = floppy_count;
+	disk->minors = 1;
 	disk->fops = &floppy_fops;
 	disk->private_data = fs;
 	disk->events = DISK_EVENT_MEDIA_CHANGE;
@@ -1237,12 +1234,10 @@ static int swim3_attach(struct macio_dev *mdev,
 	disks[floppy_count++] = disk;
 	return 0;
 
-out_cleanup_queue:
-	blk_cleanup_queue(disk->queue);
-	disk->queue = NULL;
+out_cleanup_disk:
+	blk_cleanup_disk(disk);
+out_free_tag_set:
 	blk_mq_free_tag_set(&fs->tag_set);
-out_put_disk:
-	put_disk(disk);
 out_unregister:
 	if (floppy_count == 0)
 		unregister_blkdev(FLOPPY_MAJOR, "fd");