[deliverable/linux.git] / drivers / mtd / mtd_blkdevs.c

/*
 * (C) 2003 David Woodhouse <dwmw2@infradead.org>
 *
 * Interface to Linux 2.5 block layer for MTD 'translation layers'.
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/fs.h>
#include <linux/mtd/blktrans.h>
#include <linux/mtd/mtd.h>
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/freezer.h>
#include <linux/spinlock.h>
#include <linux/hdreg.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
#include <asm/uaccess.h>

#include "mtdcore.h"

static LIST_HEAD(blktrans_majors);

struct mtd_blkcore_priv {
	struct task_struct *thread;
	struct request_queue *rq;
	spinlock_t queue_lock;
};

static int do_blktrans_request(struct mtd_blktrans_ops *tr,
			       struct mtd_blktrans_dev *dev,
			       struct request *req)
{
	unsigned long block, nsect;
	char *buf;

	block = blk_rq_pos(req) << 9 >> tr->blkshift;
	nsect = blk_rq_cur_bytes(req) >> tr->blkshift;

	buf = req->buffer;

	if (!blk_fs_request(req))
		return -EIO;

	if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
	    get_capacity(req->rq_disk))
		return -EIO;

	if (blk_discard_rq(req))
		return tr->discard(dev, block, nsect);

	switch(rq_data_dir(req)) {
	case READ:
		for (; nsect > 0; nsect--, block++, buf += tr->blksize)
			if (tr->readsect(dev, block, buf))
				return -EIO;
		return 0;

	case WRITE:
		if (!tr->writesect)
			return -EIO;

		for (; nsect > 0; nsect--, block++, buf += tr->blksize)
			if (tr->writesect(dev, block, buf))
				return -EIO;
		return 0;

	default:
		printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
		return -EIO;
	}
}

static int mtd_blktrans_thread(void *arg)
{
	struct mtd_blktrans_ops *tr = arg;
	struct request_queue *rq = tr->blkcore_priv->rq;
	struct request *req = NULL;

	/* we might get involved when memory gets low, so use PF_MEMALLOC */
	current->flags |= PF_MEMALLOC;

	spin_lock_irq(rq->queue_lock);

	while (!kthread_should_stop()) {
		struct mtd_blktrans_dev *dev;
		int res;

		if (!req && !(req = blk_fetch_request(rq))) {
			set_current_state(TASK_INTERRUPTIBLE);
			spin_unlock_irq(rq->queue_lock);
			schedule();
			spin_lock_irq(rq->queue_lock);
			continue;
		}

		dev = req->rq_disk->private_data;
		tr = dev->tr;

		spin_unlock_irq(rq->queue_lock);

		mutex_lock(&dev->lock);
		res = do_blktrans_request(tr, dev, req);
		mutex_unlock(&dev->lock);

		spin_lock_irq(rq->queue_lock);

		if (!__blk_end_request_cur(req, res))
			req = NULL;
	}

	if (req)
		__blk_end_request_all(req, -EIO);

	spin_unlock_irq(rq->queue_lock);

	return 0;
}

static void mtd_blktrans_request(struct request_queue *rq)
{
	struct mtd_blktrans_ops *tr = rq->queuedata;
	wake_up_process(tr->blkcore_priv->thread);
}


static int blktrans_open(struct block_device *bdev, fmode_t mode)
{
	struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
	struct mtd_blktrans_ops *tr = dev->tr;
	int ret = -ENODEV;

	if (!get_mtd_device(NULL, dev->mtd->index))
		goto out;

	if (!try_module_get(tr->owner))
		goto out_tr;

	/* FIXME: Locking. A hot pluggable device can go away
	   (del_mtd_device can be called for it) without its module
	   being unloaded. */
	dev->mtd->usecount++;

	ret = 0;
	if (tr->open && (ret = tr->open(dev))) {
		dev->mtd->usecount--;
		put_mtd_device(dev->mtd);
	out_tr:
		module_put(tr->owner);
	}
 out:
	return ret;
}

static int blktrans_release(struct gendisk *disk, fmode_t mode)
{
	struct mtd_blktrans_dev *dev = disk->private_data;
	struct mtd_blktrans_ops *tr = dev->tr;
	int ret = 0;

	if (tr->release)
		ret = tr->release(dev);

	if (!ret) {
		dev->mtd->usecount--;
		put_mtd_device(dev->mtd);
		module_put(tr->owner);
	}

	return ret;
}

static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;

	if (dev->tr->getgeo)
		return dev->tr->getgeo(dev, geo);
	return -ENOTTY;
}

static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
			      unsigned int cmd, unsigned long arg)
{
	struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
	struct mtd_blktrans_ops *tr = dev->tr;

	switch (cmd) {
	case BLKFLSBUF:
		if (tr->flush)
			return tr->flush(dev);
		/* The core code did the work, we had nothing to do. */
		return 0;
	default:
		return -ENOTTY;
	}
}

static const struct block_device_operations mtd_blktrans_ops = {
	.owner		= THIS_MODULE,
	.open		= blktrans_open,
	.release	= blktrans_release,
	.locked_ioctl	= blktrans_ioctl,
	.getgeo		= blktrans_getgeo,
};

int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
{
	struct mtd_blktrans_ops *tr = new->tr;
	struct mtd_blktrans_dev *d;
	int last_devnum = -1;
	struct gendisk *gd;

	if (mutex_trylock(&mtd_table_mutex)) {
		mutex_unlock(&mtd_table_mutex);
		BUG();
	}

	list_for_each_entry(d, &tr->devs, list) {
		if (new->devnum == -1) {
			/* Use first free number */
			if (d->devnum != last_devnum+1) {
				/* Found a free devnum. Plug it in here */
				new->devnum = last_devnum+1;
				list_add_tail(&new->list, &d->list);
				goto added;
			}
		} else if (d->devnum == new->devnum) {
			/* Required number taken */
			return -EBUSY;
		} else if (d->devnum > new->devnum) {
			/* Required number was free */
			list_add_tail(&new->list, &d->list);
			goto added;
		}
		last_devnum = d->devnum;
	}
	if (new->devnum == -1)
		new->devnum = last_devnum+1;

	if ((new->devnum << tr->part_bits) > 256) {
		return -EBUSY;
	}

	list_add_tail(&new->list, &tr->devs);
 added:
	mutex_init(&new->lock);
	if (!tr->writesect)
		new->readonly = 1;

	gd = alloc_disk(1 << tr->part_bits);
	if (!gd) {
		list_del(&new->list);
		return -ENOMEM;
	}
	gd->major = tr->major;
	gd->first_minor = (new->devnum) << tr->part_bits;
	gd->fops = &mtd_blktrans_ops;

	if (tr->part_bits)
		if (new->devnum < 26)
			snprintf(gd->disk_name, sizeof(gd->disk_name),
				 "%s%c", tr->name, 'a' + new->devnum);
		else
			snprintf(gd->disk_name, sizeof(gd->disk_name),
				 "%s%c%c", tr->name,
				 'a' - 1 + new->devnum / 26,
				 'a' + new->devnum % 26);
	else
		snprintf(gd->disk_name, sizeof(gd->disk_name),
			 "%s%d", tr->name, new->devnum);

	/* 2.5 has capacity in units of 512 bytes while still
	   having BLOCK_SIZE_BITS set to 10. Just to keep us amused. */
	set_capacity(gd, (new->size * tr->blksize) >> 9);

	gd->private_data = new;
	new->blkcore_priv = gd;
	gd->queue = tr->blkcore_priv->rq;
	gd->driverfs_dev = &new->mtd->dev;

	if (new->readonly)
		set_disk_ro(gd, 1);

	add_disk(gd);

	return 0;
}

int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
{
	if (mutex_trylock(&mtd_table_mutex)) {
		mutex_unlock(&mtd_table_mutex);
		BUG();
	}

	list_del(&old->list);

	del_gendisk(old->blkcore_priv);
	put_disk(old->blkcore_priv);

	return 0;
}

static void blktrans_notify_remove(struct mtd_info *mtd)
{
	struct mtd_blktrans_ops *tr;
	struct mtd_blktrans_dev *dev, *next;

	list_for_each_entry(tr, &blktrans_majors, list)
		list_for_each_entry_safe(dev, next, &tr->devs, list)
			if (dev->mtd == mtd)
				tr->remove_dev(dev);
}

static void blktrans_notify_add(struct mtd_info *mtd)
{
	struct mtd_blktrans_ops *tr;

	if (mtd->type == MTD_ABSENT)
		return;

	list_for_each_entry(tr, &blktrans_majors, list)
		tr->add_mtd(tr, mtd);
}

static struct mtd_notifier blktrans_notifier = {
	.add = blktrans_notify_add,
	.remove = blktrans_notify_remove,
};

int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
{
	int ret, i;

	/* Register the notifier if/when the first device type is
	   registered, to prevent the link/init ordering from fucking
	   us over. */
	if (!blktrans_notifier.list.next)
		register_mtd_user(&blktrans_notifier);

	tr->blkcore_priv = kzalloc(sizeof(*tr->blkcore_priv), GFP_KERNEL);
	if (!tr->blkcore_priv)
		return -ENOMEM;

	mutex_lock(&mtd_table_mutex);

	ret = register_blkdev(tr->major, tr->name);
	if (ret) {
		printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
		       tr->name, tr->major, ret);
		kfree(tr->blkcore_priv);
		mutex_unlock(&mtd_table_mutex);
		return ret;
	}
	spin_lock_init(&tr->blkcore_priv->queue_lock);

	tr->blkcore_priv->rq = blk_init_queue(mtd_blktrans_request, &tr->blkcore_priv->queue_lock);
	if (!tr->blkcore_priv->rq) {
		unregister_blkdev(tr->major, tr->name);
		kfree(tr->blkcore_priv);
		mutex_unlock(&mtd_table_mutex);
		return -ENOMEM;
	}

	tr->blkcore_priv->rq->queuedata = tr;
	blk_queue_logical_block_size(tr->blkcore_priv->rq, tr->blksize);
	if (tr->discard)
		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
					tr->blkcore_priv->rq);

	tr->blkshift = ffs(tr->blksize) - 1;

	tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr,
			"%sd", tr->name);
	if (IS_ERR(tr->blkcore_priv->thread)) {
		int ret = PTR_ERR(tr->blkcore_priv->thread);
		blk_cleanup_queue(tr->blkcore_priv->rq);
		unregister_blkdev(tr->major, tr->name);
		kfree(tr->blkcore_priv);
		mutex_unlock(&mtd_table_mutex);
		return ret;
	}

	INIT_LIST_HEAD(&tr->devs);
	list_add(&tr->list, &blktrans_majors);

	for (i=0; i<MAX_MTD_DEVICES; i++) {
		if (mtd_table[i] && mtd_table[i]->type != MTD_ABSENT)
			tr->add_mtd(tr, mtd_table[i]);
	}

	mutex_unlock(&mtd_table_mutex);

	return 0;
}

int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
{
	struct mtd_blktrans_dev *dev, *next;

	mutex_lock(&mtd_table_mutex);

	/* Clean up the kernel thread */
	kthread_stop(tr->blkcore_priv->thread);

	/* Remove it from the list of active majors */
	list_del(&tr->list);

	list_for_each_entry_safe(dev, next, &tr->devs, list)
		tr->remove_dev(dev);

	blk_cleanup_queue(tr->blkcore_priv->rq);
	unregister_blkdev(tr->major, tr->name);

	mutex_unlock(&mtd_table_mutex);

	kfree(tr->blkcore_priv);

	BUG_ON(!list_empty(&tr->devs));
	return 0;
}

static void __exit mtd_blktrans_exit(void)
{
	/* No race here -- if someone's currently in register_mtd_blktrans
	   we're screwed anyway. */
	if (blktrans_notifier.list.next)
		unregister_mtd_user(&blktrans_notifier);
}

module_exit(mtd_blktrans_exit);

EXPORT_SYMBOL_GPL(register_mtd_blktrans);
EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);

MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	2	* (C) 2003 David Woodhouse <dwmw2@infradead.org>
	3	*
	4	* Interface to Linux 2.5 block layer for MTD 'translation layers'.
	5	*
	6	*/
	7
	8	#include <linux/kernel.h>
	9	#include <linux/slab.h>
	10	#include <linux/module.h>
	11	#include <linux/list.h>
	12	#include <linux/fs.h>
	13	#include <linux/mtd/blktrans.h>
	14	#include <linux/mtd/mtd.h>
	15	#include <linux/blkdev.h>
	16	#include <linux/blkpg.h>
83144186	17	#include <linux/freezer.h>
1da177e4 LT	18	#include <linux/spinlock.h>
	19	#include <linux/hdreg.h>
	20	#include <linux/init.h>
48b19268	21	#include <linux/mutex.h>
99f9b243	22	#include <linux/kthread.h>
1da177e4	23	#include <asm/uaccess.h>
1da177e4	24
356d70f1	25	#include "mtdcore.h"
1da177e4	26
356d70f1	27	static LIST_HEAD(blktrans_majors);
1da177e4 LT	28
1da177e4 LT	29	struct mtd_blkcore_priv {
3e67fe45	30	struct task_struct *thread;
1da177e4 LT	31	struct request_queue *rq;
	32	spinlock_t queue_lock;
	33	};
	34
	35	static int do_blktrans_request(struct mtd_blktrans_ops *tr,
	36	struct mtd_blktrans_dev *dev,
	37	struct request *req)
	38	{
	39	unsigned long block, nsect;
	40	char *buf;
	41
83096ebf	42	block = blk_rq_pos(req) << 9 >> tr->blkshift;
1011c1b9	43	nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
19187672	44
1da177e4 LT	45	buf = req->buffer;
1da177e4 LT	46
4aff5e23	47	if (!blk_fs_request(req))
f06d9a2b	48	return -EIO;
1da177e4	49
83096ebf TH	50	if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
83096ebf TH	51	get_capacity(req->rq_disk))
f06d9a2b	52	return -EIO;
1da177e4	53
c15227de CH	54	if (blk_discard_rq(req))
	55	return tr->discard(dev, block, nsect);
	56
1da177e4 LT	57	switch(rq_data_dir(req)) {
1da177e4 LT	58	case READ:
19187672	59	for (; nsect > 0; nsect--, block++, buf += tr->blksize)
1da177e4	60	if (tr->readsect(dev, block, buf))
f06d9a2b TH	61	return -EIO;
f06d9a2b TH	62	return 0;
1da177e4 LT	63
	64	case WRITE:
	65	if (!tr->writesect)
f06d9a2b	66	return -EIO;
1da177e4	67
19187672	68	for (; nsect > 0; nsect--, block++, buf += tr->blksize)
1da177e4	69	if (tr->writesect(dev, block, buf))
f06d9a2b TH	70	return -EIO;
f06d9a2b TH	71	return 0;
1da177e4 LT	72
1da177e4 LT	73	default:
9a292308	74	printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
f06d9a2b	75	return -EIO;
1da177e4 LT	76	}
	77	}
	78
	79	static int mtd_blktrans_thread(void *arg)
	80	{
	81	struct mtd_blktrans_ops *tr = arg;
	82	struct request_queue *rq = tr->blkcore_priv->rq;
1498ada7	83	struct request *req = NULL;
1da177e4 LT	84
1da177e4 LT	85	/* we might get involved when memory gets low, so use PF_MEMALLOC */
83144186	86	current->flags \|= PF_MEMALLOC;
1da177e4	87
1da177e4	88	spin_lock_irq(rq->queue_lock);
1498ada7	89
3e67fe45	90	while (!kthread_should_stop()) {
1da177e4	91	struct mtd_blktrans_dev *dev;
f06d9a2b	92	int res;
1da177e4	93
9934c8c0	94	if (!req && !(req = blk_fetch_request(rq))) {
1da177e4	95	set_current_state(TASK_INTERRUPTIBLE);
1da177e4	96	spin_unlock_irq(rq->queue_lock);
1da177e4	97	schedule();
1da177e4	98	spin_lock_irq(rq->queue_lock);
1da177e4 LT	99	continue;
	100	}
	101
	102	dev = req->rq_disk->private_data;
	103	tr = dev->tr;
	104
	105	spin_unlock_irq(rq->queue_lock);
	106
48b19268	107	mutex_lock(&dev->lock);
1da177e4	108	res = do_blktrans_request(tr, dev, req);
48b19268	109	mutex_unlock(&dev->lock);
1da177e4 LT	110
	111	spin_lock_irq(rq->queue_lock);
	112
1498ada7 TH	113	if (!__blk_end_request_cur(req, res))
1498ada7 TH	114	req = NULL;
1da177e4	115	}
1498ada7 TH	116
	117	if (req)
	118	__blk_end_request_all(req, -EIO);
	119
1da177e4 LT	120	spin_unlock_irq(rq->queue_lock);
1da177e4 LT	121
3e67fe45	122	return 0;
1da177e4 LT	123	}
	124
	125	static void mtd_blktrans_request(struct request_queue *rq)
	126	{
	127	struct mtd_blktrans_ops *tr = rq->queuedata;
3e67fe45	128	wake_up_process(tr->blkcore_priv->thread);
1da177e4 LT	129	}
	130
	131
af0e2a0a	132	static int blktrans_open(struct block_device *bdev, fmode_t mode)
1da177e4	133	{
af0e2a0a AV	134	struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
af0e2a0a AV	135	struct mtd_blktrans_ops *tr = dev->tr;
1da177e4 LT	136	int ret = -ENODEV;
1da177e4 LT	137
8022c13c	138	if (!get_mtd_device(NULL, dev->mtd->index))
1da177e4 LT	139	goto out;
	140
	141	if (!try_module_get(tr->owner))
	142	goto out_tr;
	143
97894cda	144	/* FIXME: Locking. A hot pluggable device can go away
1da177e4 LT	145	(del_mtd_device can be called for it) without its module
	146	being unloaded. */
	147	dev->mtd->usecount++;
	148
	149	ret = 0;
	150	if (tr->open && (ret = tr->open(dev))) {
	151	dev->mtd->usecount--;
8022c13c	152	put_mtd_device(dev->mtd);
1da177e4 LT	153	out_tr:
	154	module_put(tr->owner);
	155	}
	156	out:
	157	return ret;
	158	}
	159
af0e2a0a	160	static int blktrans_release(struct gendisk *disk, fmode_t mode)
1da177e4	161	{
af0e2a0a AV	162	struct mtd_blktrans_dev *dev = disk->private_data;
af0e2a0a AV	163	struct mtd_blktrans_ops *tr = dev->tr;
1da177e4 LT	164	int ret = 0;
1da177e4 LT	165
1da177e4 LT	166	if (tr->release)
	167	ret = tr->release(dev);
	168
	169	if (!ret) {
	170	dev->mtd->usecount--;
8022c13c	171	put_mtd_device(dev->mtd);
1da177e4 LT	172	module_put(tr->owner);
	173	}
	174
	175	return ret;
	176	}
	177
a885c8c4 CH	178	static int blktrans_getgeo(struct block_device bdev, struct hd_geometry geo)
	179	{
	180	struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
	181
	182	if (dev->tr->getgeo)
	183	return dev->tr->getgeo(dev, geo);
	184	return -ENOTTY;
	185	}
1da177e4	186
af0e2a0a	187	static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
1da177e4 LT	188	unsigned int cmd, unsigned long arg)
1da177e4 LT	189	{
af0e2a0a	190	struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
1da177e4 LT	191	struct mtd_blktrans_ops *tr = dev->tr;
	192
	193	switch (cmd) {
	194	case BLKFLSBUF:
	195	if (tr->flush)
	196	return tr->flush(dev);
	197	/* The core code did the work, we had nothing to do. */
	198	return 0;
1da177e4 LT	199	default:
	200	return -ENOTTY;
	201	}
	202	}
	203
83d5cde4	204	static const struct block_device_operations mtd_blktrans_ops = {
1da177e4	205	.owner = THIS_MODULE,
af0e2a0a AV	206	.open = blktrans_open,
	207	.release = blktrans_release,
	208	.locked_ioctl = blktrans_ioctl,
a885c8c4	209	.getgeo = blktrans_getgeo,
1da177e4 LT	210	};
	211
	212	int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
	213	{
	214	struct mtd_blktrans_ops *tr = new->tr;
71a928c0	215	struct mtd_blktrans_dev *d;
1da177e4 LT	216	int last_devnum = -1;
	217	struct gendisk *gd;
	218
b3561ea9	219	if (mutex_trylock(&mtd_table_mutex)) {
48b19268	220	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	221	BUG();
	222	}
	223
71a928c0	224	list_for_each_entry(d, &tr->devs, list) {
1da177e4 LT	225	if (new->devnum == -1) {
	226	/* Use first free number */
	227	if (d->devnum != last_devnum+1) {
	228	/* Found a free devnum. Plug it in here */
	229	new->devnum = last_devnum+1;
	230	list_add_tail(&new->list, &d->list);
	231	goto added;
	232	}
	233	} else if (d->devnum == new->devnum) {
	234	/* Required number taken */
	235	return -EBUSY;
	236	} else if (d->devnum > new->devnum) {
	237	/* Required number was free */
	238	list_add_tail(&new->list, &d->list);
	239	goto added;
97894cda	240	}
1da177e4 LT	241	last_devnum = d->devnum;
	242	}
	243	if (new->devnum == -1)
	244	new->devnum = last_devnum+1;
	245
	246	if ((new->devnum << tr->part_bits) > 256) {
	247	return -EBUSY;
	248	}
	249
1da177e4 LT	250	list_add_tail(&new->list, &tr->devs);
1da177e4 LT	251	added:
ce37ab42	252	mutex_init(&new->lock);
1da177e4 LT	253	if (!tr->writesect)
	254	new->readonly = 1;
	255
	256	gd = alloc_disk(1 << tr->part_bits);
	257	if (!gd) {
	258	list_del(&new->list);
	259	return -ENOMEM;
	260	}
	261	gd->major = tr->major;
	262	gd->first_minor = (new->devnum) << tr->part_bits;
	263	gd->fops = &mtd_blktrans_ops;
97894cda	264
65a8de36 TP	265	if (tr->part_bits)
	266	if (new->devnum < 26)
	267	snprintf(gd->disk_name, sizeof(gd->disk_name),
	268	"%s%c", tr->name, 'a' + new->devnum);
	269	else
	270	snprintf(gd->disk_name, sizeof(gd->disk_name),
	271	"%s%c%c", tr->name,
	272	'a' - 1 + new->devnum / 26,
	273	'a' + new->devnum % 26);
	274	else
	275	snprintf(gd->disk_name, sizeof(gd->disk_name),
	276	"%s%d", tr->name, new->devnum);
1da177e4 LT	277
	278	/* 2.5 has capacity in units of 512 bytes while still
	279	having BLOCK_SIZE_BITS set to 10. Just to keep us amused. */
19187672	280	set_capacity(gd, (new->size * tr->blksize) >> 9);
1da177e4 LT	281
	282	gd->private_data = new;
	283	new->blkcore_priv = gd;
	284	gd->queue = tr->blkcore_priv->rq;
d694846b	285	gd->driverfs_dev = &new->mtd->dev;
1da177e4 LT	286
	287	if (new->readonly)
	288	set_disk_ro(gd, 1);
	289
	290	add_disk(gd);
97894cda	291
1da177e4 LT	292	return 0;
	293	}
	294
	295	int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
	296	{
b3561ea9	297	if (mutex_trylock(&mtd_table_mutex)) {
48b19268	298	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	299	BUG();
	300	}
	301
	302	list_del(&old->list);
	303
	304	del_gendisk(old->blkcore_priv);
	305	put_disk(old->blkcore_priv);
97894cda	306
1da177e4 LT	307	return 0;
	308	}
	309
	310	static void blktrans_notify_remove(struct mtd_info *mtd)
	311	{
71a928c0 CM	312	struct mtd_blktrans_ops *tr;
71a928c0 CM	313	struct mtd_blktrans_dev dev, next;
1da177e4	314
71a928c0 CM	315	list_for_each_entry(tr, &blktrans_majors, list)
71a928c0 CM	316	list_for_each_entry_safe(dev, next, &tr->devs, list)
1da177e4 LT	317	if (dev->mtd == mtd)
1da177e4 LT	318	tr->remove_dev(dev);
1da177e4 LT	319	}
	320
	321	static void blktrans_notify_add(struct mtd_info *mtd)
	322	{
71a928c0	323	struct mtd_blktrans_ops *tr;
1da177e4 LT	324
	325	if (mtd->type == MTD_ABSENT)
	326	return;
	327
71a928c0	328	list_for_each_entry(tr, &blktrans_majors, list)
1da177e4	329	tr->add_mtd(tr, mtd);
1da177e4 LT	330	}
	331
	332	static struct mtd_notifier blktrans_notifier = {
	333	.add = blktrans_notify_add,
	334	.remove = blktrans_notify_remove,
	335	};
97894cda	336
1da177e4 LT	337	int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
	338	{
	339	int ret, i;
	340
97894cda	341	/* Register the notifier if/when the first device type is
1da177e4 LT	342	registered, to prevent the link/init ordering from fucking
	343	us over. */
	344	if (!blktrans_notifier.list.next)
	345	register_mtd_user(&blktrans_notifier);
	346
95b93a0c	347	tr->blkcore_priv = kzalloc(sizeof(*tr->blkcore_priv), GFP_KERNEL);
1da177e4 LT	348	if (!tr->blkcore_priv)
	349	return -ENOMEM;
	350
48b19268	351	mutex_lock(&mtd_table_mutex);
1da177e4 LT	352
	353	ret = register_blkdev(tr->major, tr->name);
	354	if (ret) {
	355	printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
	356	tr->name, tr->major, ret);
	357	kfree(tr->blkcore_priv);
48b19268	358	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	359	return ret;
	360	}
	361	spin_lock_init(&tr->blkcore_priv->queue_lock);
1da177e4 LT	362
	363	tr->blkcore_priv->rq = blk_init_queue(mtd_blktrans_request, &tr->blkcore_priv->queue_lock);
	364	if (!tr->blkcore_priv->rq) {
	365	unregister_blkdev(tr->major, tr->name);
	366	kfree(tr->blkcore_priv);
48b19268	367	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	368	return -ENOMEM;
	369	}
	370
	371	tr->blkcore_priv->rq->queuedata = tr;
e1defc4f	372	blk_queue_logical_block_size(tr->blkcore_priv->rq, tr->blksize);
eae9acd1	373	if (tr->discard)
c15227de CH	374	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
c15227de CH	375	tr->blkcore_priv->rq);
eae9acd1	376
19187672	377	tr->blkshift = ffs(tr->blksize) - 1;
1da177e4	378
3e67fe45 CH	379	tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr,
	380	"%sd", tr->name);
	381	if (IS_ERR(tr->blkcore_priv->thread)) {
2cf3a114	382	int ret = PTR_ERR(tr->blkcore_priv->thread);
1da177e4 LT	383	blk_cleanup_queue(tr->blkcore_priv->rq);
	384	unregister_blkdev(tr->major, tr->name);
	385	kfree(tr->blkcore_priv);
48b19268	386	mutex_unlock(&mtd_table_mutex);
2cf3a114	387	return ret;
97894cda	388	}
1da177e4	389
1da177e4 LT	390	INIT_LIST_HEAD(&tr->devs);
	391	list_add(&tr->list, &blktrans_majors);
	392
	393	for (i=0; i<MAX_MTD_DEVICES; i++) {
	394	if (mtd_table[i] && mtd_table[i]->type != MTD_ABSENT)
	395	tr->add_mtd(tr, mtd_table[i]);
	396	}
	397
48b19268	398	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	399
	400	return 0;
	401	}
	402
	403	int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
	404	{
71a928c0	405	struct mtd_blktrans_dev dev, next;
1da177e4	406
48b19268	407	mutex_lock(&mtd_table_mutex);
1da177e4 LT	408
1da177e4 LT	409	/* Clean up the kernel thread */
3e67fe45	410	kthread_stop(tr->blkcore_priv->thread);
1da177e4 LT	411
	412	/* Remove it from the list of active majors */
	413	list_del(&tr->list);
	414
71a928c0	415	list_for_each_entry_safe(dev, next, &tr->devs, list)
1da177e4	416	tr->remove_dev(dev);
1da177e4	417
1da177e4 LT	418	blk_cleanup_queue(tr->blkcore_priv->rq);
	419	unregister_blkdev(tr->major, tr->name);
	420
48b19268	421	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	422
	423	kfree(tr->blkcore_priv);
	424
373ebfbf	425	BUG_ON(!list_empty(&tr->devs));
1da177e4 LT	426	return 0;
	427	}
	428
	429	static void __exit mtd_blktrans_exit(void)
	430	{
	431	/* No race here -- if someone's currently in register_mtd_blktrans
	432	we're screwed anyway. */
	433	if (blktrans_notifier.list.next)
	434	unregister_mtd_user(&blktrans_notifier);
	435	}
	436
	437	module_exit(mtd_blktrans_exit);
	438
	439	EXPORT_SYMBOL_GPL(register_mtd_blktrans);
	440	EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
	441	EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
	442	EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
	443
	444	MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
	445	MODULE_LICENSE("GPL");
	446	MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");