[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / block / virtio_blk.c

//#define DEBUG
#include <linux/spinlock.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/virtio.h>
#include <linux/virtio_blk.h>
#include <linux/scatterlist.h>

#define VIRTIO_MAX_SG	(3+MAX_PHYS_SEGMENTS)
#define PART_BITS 4

static int major, index;

struct virtio_blk
{
	spinlock_t lock;

	struct virtio_device *vdev;
	struct virtqueue *vq;

	/* The disk structure for the kernel. */
	struct gendisk *disk;

	/* Request tracking. */
	struct list_head reqs;

	mempool_t *pool;

	/* Scatterlist: can be too big for stack. */
	struct scatterlist sg[VIRTIO_MAX_SG];
};

struct virtblk_req
{
	struct list_head list;
	struct request *req;
	struct virtio_blk_outhdr out_hdr;
	u8 status;
};

static void blk_done(struct virtqueue *vq)
{
	struct virtio_blk *vblk = vq->vdev->priv;
	struct virtblk_req *vbr;
	unsigned int len;
	unsigned long flags;

	spin_lock_irqsave(&vblk->lock, flags);
	while ((vbr = vblk->vq->vq_ops->get_buf(vblk->vq, &len)) != NULL) {
		int error;
		switch (vbr->status) {
		case VIRTIO_BLK_S_OK:
			error = 0;
			break;
		case VIRTIO_BLK_S_UNSUPP:
			error = -ENOTTY;
			break;
		default:
			error = -EIO;
			break;
		}

		__blk_end_request(vbr->req, error, blk_rq_bytes(vbr->req));
		list_del(&vbr->list);
		mempool_free(vbr, vblk->pool);
	}
	/* In case queue is stopped waiting for more buffers. */
	blk_start_queue(vblk->disk->queue);
	spin_unlock_irqrestore(&vblk->lock, flags);
}

static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
		   struct request *req)
{
	unsigned long num, out, in;
	struct virtblk_req *vbr;

	vbr = mempool_alloc(vblk->pool, GFP_ATOMIC);
	if (!vbr)
		/* When another request finishes we'll try again. */
		return false;

	vbr->req = req;
	if (blk_fs_request(vbr->req)) {
		vbr->out_hdr.type = 0;
		vbr->out_hdr.sector = vbr->req->sector;
		vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
	} else if (blk_pc_request(vbr->req)) {
		vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD;
		vbr->out_hdr.sector = 0;
		vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
	} else {
		/* We don't put anything else in the queue. */
		BUG();
	}

	if (blk_barrier_rq(vbr->req))
		vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER;

	/* This init could be done at vblk creation time */
	sg_init_table(vblk->sg, VIRTIO_MAX_SG);
	sg_set_buf(&vblk->sg[0], &vbr->out_hdr, sizeof(vbr->out_hdr));
	num = blk_rq_map_sg(q, vbr->req, vblk->sg+1);
	sg_set_buf(&vblk->sg[num+1], &vbr->status, sizeof(vbr->status));

	if (rq_data_dir(vbr->req) == WRITE) {
		vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
		out = 1 + num;
		in = 1;
	} else {
		vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
		out = 1;
		in = 1 + num;
	}

	if (vblk->vq->vq_ops->add_buf(vblk->vq, vblk->sg, out, in, vbr)) {
		mempool_free(vbr, vblk->pool);
		return false;
	}

	list_add_tail(&vbr->list, &vblk->reqs);
	return true;
}

static void do_virtblk_request(struct request_queue *q)
{
	struct virtio_blk *vblk = NULL;
	struct request *req;
	unsigned int issued = 0;

	while ((req = elv_next_request(q)) != NULL) {
		vblk = req->rq_disk->private_data;
		BUG_ON(req->nr_phys_segments > ARRAY_SIZE(vblk->sg));

		/* If this request fails, stop queue and wait for something to
		   finish to restart it. */
		if (!do_req(q, vblk, req)) {
			blk_stop_queue(q);
			break;
		}
		blkdev_dequeue_request(req);
		issued++;
	}

	if (issued)
		vblk->vq->vq_ops->kick(vblk->vq);
}

static int virtblk_ioctl(struct inode *inode, struct file *filp,
			 unsigned cmd, unsigned long data)
{
	return scsi_cmd_ioctl(inode->i_bdev->bd_disk->queue,
			      inode->i_bdev->bd_disk, filp->f_mode, cmd,
			      (void __user *)data);
}

/* We provide getgeo only to please some old bootloader/partitioning tools */
static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
{
	struct virtio_blk *vblk = bd->bd_disk->private_data;
	struct virtio_blk_geometry vgeo;
	int err;

	/* see if the host passed in geometry config */
	err = virtio_config_val(vblk->vdev, VIRTIO_BLK_F_GEOMETRY,
				offsetof(struct virtio_blk_config, geometry),
				&vgeo);

	if (!err) {
		geo->heads = vgeo.heads;
		geo->sectors = vgeo.sectors;
		geo->cylinders = vgeo.cylinders;
	} else {
		/* some standard values, similar to sd */
		geo->heads = 1 << 6;
		geo->sectors = 1 << 5;
		geo->cylinders = get_capacity(bd->bd_disk) >> 11;
	}
	return 0;
}

static struct block_device_operations virtblk_fops = {
	.ioctl  = virtblk_ioctl,
	.owner  = THIS_MODULE,
	.getgeo = virtblk_getgeo,
};

static int index_to_minor(int index)
{
	return index << PART_BITS;
}

static int virtblk_probe(struct virtio_device *vdev)
{
	struct virtio_blk *vblk;
	int err;
	u64 cap;
	u32 v;
	u32 blk_size;

	if (index_to_minor(index) >= 1 << MINORBITS)
		return -ENOSPC;

	vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
	if (!vblk) {
		err = -ENOMEM;
		goto out;
	}

	INIT_LIST_HEAD(&vblk->reqs);
	spin_lock_init(&vblk->lock);
	vblk->vdev = vdev;

	/* We expect one virtqueue, for output. */
	vblk->vq = vdev->config->find_vq(vdev, 0, blk_done);
	if (IS_ERR(vblk->vq)) {
		err = PTR_ERR(vblk->vq);
		goto out_free_vblk;
	}

	vblk->pool = mempool_create_kmalloc_pool(1,sizeof(struct virtblk_req));
	if (!vblk->pool) {
		err = -ENOMEM;
		goto out_free_vq;
	}

	/* FIXME: How many partitions?  How long is a piece of string? */
	vblk->disk = alloc_disk(1 << PART_BITS);
	if (!vblk->disk) {
		err = -ENOMEM;
		goto out_mempool;
	}

	vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock);
	if (!vblk->disk->queue) {
		err = -ENOMEM;
		goto out_put_disk;
	}

	if (index < 26) {
		sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26);
	} else if (index < (26 + 1) * 26) {
		sprintf(vblk->disk->disk_name, "vd%c%c",
			'a' + index / 26 - 1, 'a' + index % 26);
	} else {
		const unsigned int m1 = (index / 26 - 1) / 26 - 1;
		const unsigned int m2 = (index / 26 - 1) % 26;
		const unsigned int m3 =  index % 26;
		sprintf(vblk->disk->disk_name, "vd%c%c%c",
			'a' + m1, 'a' + m2, 'a' + m3);
	}

	vblk->disk->major = major;
	vblk->disk->first_minor = index_to_minor(index);
	vblk->disk->private_data = vblk;
	vblk->disk->fops = &virtblk_fops;
	vblk->disk->driverfs_dev = &vdev->dev;
	index++;

	/* If barriers are supported, tell block layer that queue is ordered */
	if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER))
		blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL);

	/* If disk is read-only in the host, the guest should obey */
	if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
		set_disk_ro(vblk->disk, 1);

	/* Host must always specify the capacity. */
	vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
			  &cap, sizeof(cap));

	/* If capacity is too big, truncate with warning. */
	if ((sector_t)cap != cap) {
		dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
			 (unsigned long long)cap);
		cap = (sector_t)-1;
	}
	set_capacity(vblk->disk, cap);

	/* Host can optionally specify maximum segment size and number of
	 * segments. */
	err = virtio_config_val(vdev, VIRTIO_BLK_F_SIZE_MAX,
				offsetof(struct virtio_blk_config, size_max),
				&v);
	if (!err)
		blk_queue_max_segment_size(vblk->disk->queue, v);

	err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
				offsetof(struct virtio_blk_config, seg_max),
				&v);
	if (!err)
		blk_queue_max_hw_segments(vblk->disk->queue, v);

	/* Host can optionally specify the block size of the device */
	err = virtio_config_val(vdev, VIRTIO_BLK_F_BLK_SIZE,
				offsetof(struct virtio_blk_config, blk_size),
				&blk_size);
	if (!err)
		blk_queue_hardsect_size(vblk->disk->queue, blk_size);

	add_disk(vblk->disk);
	return 0;

out_put_disk:
	put_disk(vblk->disk);
out_mempool:
	mempool_destroy(vblk->pool);
out_free_vq:
	vdev->config->del_vq(vblk->vq);
out_free_vblk:
	kfree(vblk);
out:
	return err;
}

static void virtblk_remove(struct virtio_device *vdev)
{
	struct virtio_blk *vblk = vdev->priv;

	/* Nothing should be pending. */
	BUG_ON(!list_empty(&vblk->reqs));

	/* Stop all the virtqueues. */
	vdev->config->reset(vdev);

	del_gendisk(vblk->disk);
	blk_cleanup_queue(vblk->disk->queue);
	put_disk(vblk->disk);
	mempool_destroy(vblk->pool);
	vdev->config->del_vq(vblk->vq);
	kfree(vblk);
}

static struct virtio_device_id id_table[] = {
	{ VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
	{ 0 },
};

static unsigned int features[] = {
	VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX,
	VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
};

static struct virtio_driver virtio_blk = {
	.feature_table = features,
	.feature_table_size = ARRAY_SIZE(features),
	.driver.name =	KBUILD_MODNAME,
	.driver.owner =	THIS_MODULE,
	.id_table =	id_table,
	.probe =	virtblk_probe,
	.remove =	__devexit_p(virtblk_remove),
};

static int __init init(void)
{
	major = register_blkdev(0, "virtblk");
	if (major < 0)
		return major;
	return register_virtio_driver(&virtio_blk);
}

static void __exit fini(void)
{
	unregister_blkdev(major, "virtblk");
	unregister_virtio_driver(&virtio_blk);
}
module_init(init);
module_exit(fini);

MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION("Virtio block driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
e467cde2 RR	1	//#define DEBUG
	2	#include <linux/spinlock.h>
	3	#include <linux/blkdev.h>
	4	#include <linux/hdreg.h>
	5	#include <linux/virtio.h>
	6	#include <linux/virtio_blk.h>
3d1266c7 JA	7	#include <linux/scatterlist.h>
	8
	9	#define VIRTIO_MAX_SG (3+MAX_PHYS_SEGMENTS)
4f3bf19c	10	#define PART_BITS 4
e467cde2	11
d50ed907	12	static int major, index;
4f3bf19c	13
e467cde2 RR	14	struct virtio_blk
	15	{
	16	spinlock_t lock;
	17
	18	struct virtio_device *vdev;
	19	struct virtqueue *vq;
	20
	21	/* The disk structure for the kernel. */
	22	struct gendisk *disk;
	23
	24	/* Request tracking. */
	25	struct list_head reqs;
	26
	27	mempool_t *pool;
	28
	29	/* Scatterlist: can be too big for stack. */
3d1266c7	30	struct scatterlist sg[VIRTIO_MAX_SG];
e467cde2 RR	31	};
	32
	33	struct virtblk_req
	34	{
	35	struct list_head list;
	36	struct request *req;
	37	struct virtio_blk_outhdr out_hdr;
cb38fa23	38	u8 status;
e467cde2 RR	39	};
e467cde2 RR	40
18445c4d	41	static void blk_done(struct virtqueue *vq)
e467cde2 RR	42	{
	43	struct virtio_blk *vblk = vq->vdev->priv;
	44	struct virtblk_req *vbr;
	45	unsigned int len;
	46	unsigned long flags;
	47
	48	spin_lock_irqsave(&vblk->lock, flags);
	49	while ((vbr = vblk->vq->vq_ops->get_buf(vblk->vq, &len)) != NULL) {
8316982a	50	int error;
cb38fa23	51	switch (vbr->status) {
e467cde2	52	case VIRTIO_BLK_S_OK:
8316982a	53	error = 0;
e467cde2 RR	54	break;
e467cde2 RR	55	case VIRTIO_BLK_S_UNSUPP:
8316982a	56	error = -ENOTTY;
e467cde2 RR	57	break;
e467cde2 RR	58	default:
8316982a	59	error = -EIO;
e467cde2 RR	60	break;
	61	}
	62
8316982a	63	__blk_end_request(vbr->req, error, blk_rq_bytes(vbr->req));
e467cde2 RR	64	list_del(&vbr->list);
	65	mempool_free(vbr, vblk->pool);
	66	}
	67	/* In case queue is stopped waiting for more buffers. */
	68	blk_start_queue(vblk->disk->queue);
	69	spin_unlock_irqrestore(&vblk->lock, flags);
e467cde2 RR	70	}
	71
	72	static bool do_req(struct request_queue q, struct virtio_blk vblk,
	73	struct request *req)
	74	{
	75	unsigned long num, out, in;
	76	struct virtblk_req *vbr;
	77
	78	vbr = mempool_alloc(vblk->pool, GFP_ATOMIC);
	79	if (!vbr)
	80	/* When another request finishes we'll try again. */
	81	return false;
	82
	83	vbr->req = req;
	84	if (blk_fs_request(vbr->req)) {
	85	vbr->out_hdr.type = 0;
	86	vbr->out_hdr.sector = vbr->req->sector;
766ca442	87	vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
e467cde2 RR	88	} else if (blk_pc_request(vbr->req)) {
	89	vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD;
	90	vbr->out_hdr.sector = 0;
766ca442	91	vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
e467cde2 RR	92	} else {
	93	/* We don't put anything else in the queue. */
	94	BUG();
	95	}
	96
	97	if (blk_barrier_rq(vbr->req))
	98	vbr->out_hdr.type \|= VIRTIO_BLK_T_BARRIER;
	99
3d1266c7 JA	100	/* This init could be done at vblk creation time */
3d1266c7 JA	101	sg_init_table(vblk->sg, VIRTIO_MAX_SG);
e467cde2 RR	102	sg_set_buf(&vblk->sg[0], &vbr->out_hdr, sizeof(vbr->out_hdr));
e467cde2 RR	103	num = blk_rq_map_sg(q, vbr->req, vblk->sg+1);
cb38fa23	104	sg_set_buf(&vblk->sg[num+1], &vbr->status, sizeof(vbr->status));
e467cde2 RR	105
	106	if (rq_data_dir(vbr->req) == WRITE) {
	107	vbr->out_hdr.type \|= VIRTIO_BLK_T_OUT;
	108	out = 1 + num;
	109	in = 1;
	110	} else {
	111	vbr->out_hdr.type \|= VIRTIO_BLK_T_IN;
	112	out = 1;
	113	in = 1 + num;
	114	}
	115
	116	if (vblk->vq->vq_ops->add_buf(vblk->vq, vblk->sg, out, in, vbr)) {
	117	mempool_free(vbr, vblk->pool);
	118	return false;
	119	}
	120
	121	list_add_tail(&vbr->list, &vblk->reqs);
	122	return true;
	123	}
	124
	125	static void do_virtblk_request(struct request_queue *q)
	126	{
	127	struct virtio_blk *vblk = NULL;
	128	struct request *req;
	129	unsigned int issued = 0;
	130
	131	while ((req = elv_next_request(q)) != NULL) {
	132	vblk = req->rq_disk->private_data;
	133	BUG_ON(req->nr_phys_segments > ARRAY_SIZE(vblk->sg));
	134
	135	/* If this request fails, stop queue and wait for something to
	136	finish to restart it. */
	137	if (!do_req(q, vblk, req)) {
	138	blk_stop_queue(q);
	139	break;
	140	}
	141	blkdev_dequeue_request(req);
	142	issued++;
	143	}
	144
	145	if (issued)
	146	vblk->vq->vq_ops->kick(vblk->vq);
	147	}
	148
	149	static int virtblk_ioctl(struct inode inode, struct file filp,
	150	unsigned cmd, unsigned long data)
	151	{
74f3c8af AV	152	return scsi_cmd_ioctl(inode->i_bdev->bd_disk->queue,
74f3c8af AV	153	inode->i_bdev->bd_disk, filp->f_mode, cmd,
e467cde2 RR	154	(void __user *)data);
	155	}
	156
135da0b0 CB	157	/* We provide getgeo only to please some old bootloader/partitioning tools */
	158	static int virtblk_getgeo(struct block_device bd, struct hd_geometry geo)
	159	{
48e4043d RH	160	struct virtio_blk *vblk = bd->bd_disk->private_data;
	161	struct virtio_blk_geometry vgeo;
	162	int err;
	163
	164	/* see if the host passed in geometry config */
	165	err = virtio_config_val(vblk->vdev, VIRTIO_BLK_F_GEOMETRY,
	166	offsetof(struct virtio_blk_config, geometry),
	167	&vgeo);
	168
	169	if (!err) {
	170	geo->heads = vgeo.heads;
	171	geo->sectors = vgeo.sectors;
	172	geo->cylinders = vgeo.cylinders;
	173	} else {
	174	/* some standard values, similar to sd */
	175	geo->heads = 1 << 6;
	176	geo->sectors = 1 << 5;
	177	geo->cylinders = get_capacity(bd->bd_disk) >> 11;
	178	}
135da0b0 CB	179	return 0;
	180	}
	181
e467cde2	182	static struct block_device_operations virtblk_fops = {
135da0b0 CB	183	.ioctl = virtblk_ioctl,
	184	.owner = THIS_MODULE,
	185	.getgeo = virtblk_getgeo,
e467cde2 RR	186	};
e467cde2 RR	187
d50ed907 CB	188	static int index_to_minor(int index)
	189	{
	190	return index << PART_BITS;
	191	}
	192
e467cde2 RR	193	static int virtblk_probe(struct virtio_device *vdev)
	194	{
	195	struct virtio_blk *vblk;
4f3bf19c	196	int err;
e467cde2 RR	197	u64 cap;
e467cde2 RR	198	u32 v;
066f4d82	199	u32 blk_size;
e467cde2	200
d50ed907	201	if (index_to_minor(index) >= 1 << MINORBITS)
4f3bf19c CB	202	return -ENOSPC;
4f3bf19c CB	203
e467cde2 RR	204	vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
	205	if (!vblk) {
	206	err = -ENOMEM;
	207	goto out;
	208	}
	209
	210	INIT_LIST_HEAD(&vblk->reqs);
	211	spin_lock_init(&vblk->lock);
	212	vblk->vdev = vdev;
	213
	214	/* We expect one virtqueue, for output. */
a586d4f6	215	vblk->vq = vdev->config->find_vq(vdev, 0, blk_done);
e467cde2 RR	216	if (IS_ERR(vblk->vq)) {
	217	err = PTR_ERR(vblk->vq);
	218	goto out_free_vblk;
	219	}
	220
	221	vblk->pool = mempool_create_kmalloc_pool(1,sizeof(struct virtblk_req));
	222	if (!vblk->pool) {
	223	err = -ENOMEM;
	224	goto out_free_vq;
	225	}
	226
e467cde2	227	/* FIXME: How many partitions? How long is a piece of string? */
4f3bf19c	228	vblk->disk = alloc_disk(1 << PART_BITS);
e467cde2 RR	229	if (!vblk->disk) {
e467cde2 RR	230	err = -ENOMEM;
4f3bf19c	231	goto out_mempool;
e467cde2 RR	232	}
	233
	234	vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock);
	235	if (!vblk->disk->queue) {
	236	err = -ENOMEM;
	237	goto out_put_disk;
	238	}
	239
d50ed907 CB	240	if (index < 26) {
	241	sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26);
	242	} else if (index < (26 + 1) * 26) {
	243	sprintf(vblk->disk->disk_name, "vd%c%c",
	244	'a' + index / 26 - 1, 'a' + index % 26);
	245	} else {
	246	const unsigned int m1 = (index / 26 - 1) / 26 - 1;
	247	const unsigned int m2 = (index / 26 - 1) % 26;
	248	const unsigned int m3 = index % 26;
	249	sprintf(vblk->disk->disk_name, "vd%c%c%c",
	250	'a' + m1, 'a' + m2, 'a' + m3);
	251	}
	252
e467cde2	253	vblk->disk->major = major;
d50ed907	254	vblk->disk->first_minor = index_to_minor(index);
e467cde2 RR	255	vblk->disk->private_data = vblk;
e467cde2 RR	256	vblk->disk->fops = &virtblk_fops;
c4839346	257	vblk->disk->driverfs_dev = &vdev->dev;
d50ed907	258	index++;
4f3bf19c	259
e467cde2	260	/* If barriers are supported, tell block layer that queue is ordered */
c45a6816	261	if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER))
e467cde2 RR	262	blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL);
e467cde2 RR	263
3ef53609 CB	264	/* If disk is read-only in the host, the guest should obey */
	265	if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
	266	set_disk_ro(vblk->disk, 1);
	267
a586d4f6	268	/* Host must always specify the capacity. */
72e61eb4 RR	269	vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity),
72e61eb4 RR	270	&cap, sizeof(cap));
e467cde2 RR	271
	272	/* If capacity is too big, truncate with warning. */
	273	if ((sector_t)cap != cap) {
	274	dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
	275	(unsigned long long)cap);
	276	cap = (sector_t)-1;
	277	}
	278	set_capacity(vblk->disk, cap);
	279
a586d4f6 RR	280	/* Host can optionally specify maximum segment size and number of
	281	* segments. */
	282	err = virtio_config_val(vdev, VIRTIO_BLK_F_SIZE_MAX,
	283	offsetof(struct virtio_blk_config, size_max),
	284	&v);
e467cde2 RR	285	if (!err)
e467cde2 RR	286	blk_queue_max_segment_size(vblk->disk->queue, v);
e467cde2	287
a586d4f6 RR	288	err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
	289	offsetof(struct virtio_blk_config, seg_max),
	290	&v);
e467cde2 RR	291	if (!err)
e467cde2 RR	292	blk_queue_max_hw_segments(vblk->disk->queue, v);
e467cde2	293
066f4d82 CB	294	/* Host can optionally specify the block size of the device */
	295	err = virtio_config_val(vdev, VIRTIO_BLK_F_BLK_SIZE,
	296	offsetof(struct virtio_blk_config, blk_size),
	297	&blk_size);
	298	if (!err)
	299	blk_queue_hardsect_size(vblk->disk->queue, blk_size);
	300
e467cde2 RR	301	add_disk(vblk->disk);
	302	return 0;
	303
	304	out_put_disk:
	305	put_disk(vblk->disk);
e467cde2 RR	306	out_mempool:
	307	mempool_destroy(vblk->pool);
	308	out_free_vq:
	309	vdev->config->del_vq(vblk->vq);
	310	out_free_vblk:
	311	kfree(vblk);
	312	out:
	313	return err;
	314	}
	315
	316	static void virtblk_remove(struct virtio_device *vdev)
	317	{
	318	struct virtio_blk *vblk = vdev->priv;
e467cde2	319
6e5aa7ef	320	/* Nothing should be pending. */
e467cde2	321	BUG_ON(!list_empty(&vblk->reqs));
6e5aa7ef RR	322
	323	/* Stop all the virtqueues. */
	324	vdev->config->reset(vdev);
	325
ac9d463a	326	del_gendisk(vblk->disk);
e467cde2 RR	327	blk_cleanup_queue(vblk->disk->queue);
e467cde2 RR	328	put_disk(vblk->disk);
e467cde2	329	mempool_destroy(vblk->pool);
74b2553f	330	vdev->config->del_vq(vblk->vq);
e467cde2 RR	331	kfree(vblk);
	332	}
	333
	334	static struct virtio_device_id id_table[] = {
	335	{ VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
	336	{ 0 },
	337	};
	338
c45a6816 RR	339	static unsigned int features[] = {
c45a6816 RR	340	VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX,
066f4d82	341	VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
c45a6816 RR	342	};
c45a6816 RR	343
e467cde2	344	static struct virtio_driver virtio_blk = {
c45a6816 RR	345	.feature_table = features,
c45a6816 RR	346	.feature_table_size = ARRAY_SIZE(features),
e467cde2 RR	347	.driver.name = KBUILD_MODNAME,
	348	.driver.owner = THIS_MODULE,
	349	.id_table = id_table,
	350	.probe = virtblk_probe,
	351	.remove = __devexit_p(virtblk_remove),
	352	};
	353
	354	static int __init init(void)
	355	{
4f3bf19c CB	356	major = register_blkdev(0, "virtblk");
	357	if (major < 0)
	358	return major;
e467cde2 RR	359	return register_virtio_driver(&virtio_blk);
	360	}
	361
	362	static void __exit fini(void)
	363	{
4f3bf19c	364	unregister_blkdev(major, "virtblk");
e467cde2 RR	365	unregister_virtio_driver(&virtio_blk);
	366	}
	367	module_init(init);
	368	module_exit(fini);
	369
	370	MODULE_DEVICE_TABLE(virtio, id_table);
	371	MODULE_DESCRIPTION("Virtio block driver");
	372	MODULE_LICENSE("GPL");