[net-next-2.6.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;
		rq_flush_dcache_pages(req);
		return 0;

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

		rq_flush_dcache_pages(req);
		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;

	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)
{
	struct mtd_info *mtd;
	int ret;

	/* 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)) {
		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);

	mtd_for_each_device(mtd)
		if (mtd->type != MTD_ABSENT)
			tr->add_mtd(tr, mtd);

	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
1122a26f 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	61	return -EIO;
2d4dc890	62	rq_flush_dcache_pages(req);
f06d9a2b	63	return 0;
1da177e4 LT	64
	65	case WRITE:
	66	if (!tr->writesect)
f06d9a2b	67	return -EIO;
1da177e4	68
2d4dc890	69	rq_flush_dcache_pages(req);
19187672	70	for (; nsect > 0; nsect--, block++, buf += tr->blksize)
1da177e4	71	if (tr->writesect(dev, block, buf))
f06d9a2b TH	72	return -EIO;
f06d9a2b TH	73	return 0;
1da177e4 LT	74
1da177e4 LT	75	default:
9a292308	76	printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
f06d9a2b	77	return -EIO;
1da177e4 LT	78	}
	79	}
	80
	81	static int mtd_blktrans_thread(void *arg)
	82	{
	83	struct mtd_blktrans_ops *tr = arg;
	84	struct request_queue *rq = tr->blkcore_priv->rq;
1498ada7	85	struct request *req = NULL;
1da177e4	86
1da177e4	87	spin_lock_irq(rq->queue_lock);
1498ada7	88
3e67fe45	89	while (!kthread_should_stop()) {
1da177e4	90	struct mtd_blktrans_dev *dev;
f06d9a2b	91	int res;
1da177e4	92
9934c8c0	93	if (!req && !(req = blk_fetch_request(rq))) {
1da177e4	94	set_current_state(TASK_INTERRUPTIBLE);
1da177e4	95	spin_unlock_irq(rq->queue_lock);
1da177e4	96	schedule();
1da177e4	97	spin_lock_irq(rq->queue_lock);
1da177e4 LT	98	continue;
	99	}
	100
	101	dev = req->rq_disk->private_data;
	102	tr = dev->tr;
	103
	104	spin_unlock_irq(rq->queue_lock);
	105
48b19268	106	mutex_lock(&dev->lock);
1da177e4	107	res = do_blktrans_request(tr, dev, req);
48b19268	108	mutex_unlock(&dev->lock);
1da177e4 LT	109
	110	spin_lock_irq(rq->queue_lock);
	111
1498ada7 TH	112	if (!__blk_end_request_cur(req, res))
1498ada7 TH	113	req = NULL;
1da177e4	114	}
1498ada7 TH	115
	116	if (req)
	117	__blk_end_request_all(req, -EIO);
	118
1da177e4 LT	119	spin_unlock_irq(rq->queue_lock);
1da177e4 LT	120
3e67fe45	121	return 0;
1da177e4 LT	122	}
	123
	124	static void mtd_blktrans_request(struct request_queue *rq)
	125	{
	126	struct mtd_blktrans_ops *tr = rq->queuedata;
3e67fe45	127	wake_up_process(tr->blkcore_priv->thread);
1da177e4 LT	128	}
	129
	130
af0e2a0a	131	static int blktrans_open(struct block_device *bdev, fmode_t mode)
1da177e4	132	{
af0e2a0a AV	133	struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
af0e2a0a AV	134	struct mtd_blktrans_ops *tr = dev->tr;
1da177e4 LT	135	int ret = -ENODEV;
1da177e4 LT	136
8022c13c	137	if (!get_mtd_device(NULL, dev->mtd->index))
1da177e4 LT	138	goto out;
	139
	140	if (!try_module_get(tr->owner))
	141	goto out_tr;
	142
97894cda	143	/* FIXME: Locking. A hot pluggable device can go away
1da177e4 LT	144	(del_mtd_device can be called for it) without its module
	145	being unloaded. */
	146	dev->mtd->usecount++;
	147
	148	ret = 0;
	149	if (tr->open && (ret = tr->open(dev))) {
	150	dev->mtd->usecount--;
8022c13c	151	put_mtd_device(dev->mtd);
1da177e4 LT	152	out_tr:
	153	module_put(tr->owner);
	154	}
	155	out:
	156	return ret;
	157	}
	158
af0e2a0a	159	static int blktrans_release(struct gendisk *disk, fmode_t mode)
1da177e4	160	{
af0e2a0a AV	161	struct mtd_blktrans_dev *dev = disk->private_data;
af0e2a0a AV	162	struct mtd_blktrans_ops *tr = dev->tr;
1da177e4 LT	163	int ret = 0;
1da177e4 LT	164
1da177e4 LT	165	if (tr->release)
	166	ret = tr->release(dev);
	167
	168	if (!ret) {
	169	dev->mtd->usecount--;
8022c13c	170	put_mtd_device(dev->mtd);
1da177e4 LT	171	module_put(tr->owner);
	172	}
	173
	174	return ret;
	175	}
	176
a885c8c4 CH	177	static int blktrans_getgeo(struct block_device bdev, struct hd_geometry geo)
	178	{
	179	struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
	180
	181	if (dev->tr->getgeo)
	182	return dev->tr->getgeo(dev, geo);
	183	return -ENOTTY;
	184	}
1da177e4	185
af0e2a0a	186	static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
1da177e4 LT	187	unsigned int cmd, unsigned long arg)
1da177e4 LT	188	{
af0e2a0a	189	struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
1da177e4 LT	190	struct mtd_blktrans_ops *tr = dev->tr;
	191
	192	switch (cmd) {
	193	case BLKFLSBUF:
	194	if (tr->flush)
	195	return tr->flush(dev);
	196	/* The core code did the work, we had nothing to do. */
	197	return 0;
1da177e4 LT	198	default:
	199	return -ENOTTY;
	200	}
	201	}
	202
83d5cde4	203	static const struct block_device_operations mtd_blktrans_ops = {
1da177e4	204	.owner = THIS_MODULE,
af0e2a0a AV	205	.open = blktrans_open,
	206	.release = blktrans_release,
	207	.locked_ioctl = blktrans_ioctl,
a885c8c4	208	.getgeo = blktrans_getgeo,
1da177e4 LT	209	};
	210
	211	int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
	212	{
	213	struct mtd_blktrans_ops *tr = new->tr;
71a928c0	214	struct mtd_blktrans_dev *d;
1da177e4 LT	215	int last_devnum = -1;
	216	struct gendisk *gd;
	217
b3561ea9	218	if (mutex_trylock(&mtd_table_mutex)) {
48b19268	219	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	220	BUG();
	221	}
	222
71a928c0	223	list_for_each_entry(d, &tr->devs, list) {
1da177e4 LT	224	if (new->devnum == -1) {
	225	/* Use first free number */
	226	if (d->devnum != last_devnum+1) {
	227	/* Found a free devnum. Plug it in here */
	228	new->devnum = last_devnum+1;
	229	list_add_tail(&new->list, &d->list);
	230	goto added;
	231	}
	232	} else if (d->devnum == new->devnum) {
	233	/* Required number taken */
	234	return -EBUSY;
	235	} else if (d->devnum > new->devnum) {
	236	/* Required number was free */
	237	list_add_tail(&new->list, &d->list);
	238	goto added;
97894cda	239	}
1da177e4 LT	240	last_devnum = d->devnum;
	241	}
	242	if (new->devnum == -1)
	243	new->devnum = last_devnum+1;
	244
	245	if ((new->devnum << tr->part_bits) > 256) {
	246	return -EBUSY;
	247	}
	248
1da177e4 LT	249	list_add_tail(&new->list, &tr->devs);
1da177e4 LT	250	added:
ce37ab42	251	mutex_init(&new->lock);
1da177e4 LT	252	if (!tr->writesect)
	253	new->readonly = 1;
	254
	255	gd = alloc_disk(1 << tr->part_bits);
	256	if (!gd) {
	257	list_del(&new->list);
	258	return -ENOMEM;
	259	}
	260	gd->major = tr->major;
	261	gd->first_minor = (new->devnum) << tr->part_bits;
	262	gd->fops = &mtd_blktrans_ops;
97894cda	263
65a8de36 TP	264	if (tr->part_bits)
	265	if (new->devnum < 26)
	266	snprintf(gd->disk_name, sizeof(gd->disk_name),
	267	"%s%c", tr->name, 'a' + new->devnum);
	268	else
	269	snprintf(gd->disk_name, sizeof(gd->disk_name),
	270	"%s%c%c", tr->name,
	271	'a' - 1 + new->devnum / 26,
	272	'a' + new->devnum % 26);
	273	else
	274	snprintf(gd->disk_name, sizeof(gd->disk_name),
	275	"%s%d", tr->name, new->devnum);
1da177e4 LT	276
	277	/* 2.5 has capacity in units of 512 bytes while still
	278	having BLOCK_SIZE_BITS set to 10. Just to keep us amused. */
19187672	279	set_capacity(gd, (new->size * tr->blksize) >> 9);
1da177e4 LT	280
	281	gd->private_data = new;
	282	new->blkcore_priv = gd;
	283	gd->queue = tr->blkcore_priv->rq;
d694846b	284	gd->driverfs_dev = &new->mtd->dev;
1da177e4 LT	285
	286	if (new->readonly)
	287	set_disk_ro(gd, 1);
	288
	289	add_disk(gd);
97894cda	290
1da177e4 LT	291	return 0;
	292	}
	293
	294	int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
	295	{
b3561ea9	296	if (mutex_trylock(&mtd_table_mutex)) {
48b19268	297	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	298	BUG();
	299	}
	300
	301	list_del(&old->list);
	302
	303	del_gendisk(old->blkcore_priv);
	304	put_disk(old->blkcore_priv);
97894cda	305
1da177e4 LT	306	return 0;
	307	}
	308
	309	static void blktrans_notify_remove(struct mtd_info *mtd)
	310	{
71a928c0 CM	311	struct mtd_blktrans_ops *tr;
71a928c0 CM	312	struct mtd_blktrans_dev dev, next;
1da177e4	313
71a928c0 CM	314	list_for_each_entry(tr, &blktrans_majors, list)
71a928c0 CM	315	list_for_each_entry_safe(dev, next, &tr->devs, list)
1da177e4 LT	316	if (dev->mtd == mtd)
1da177e4 LT	317	tr->remove_dev(dev);
1da177e4 LT	318	}
	319
	320	static void blktrans_notify_add(struct mtd_info *mtd)
	321	{
71a928c0	322	struct mtd_blktrans_ops *tr;
1da177e4 LT	323
	324	if (mtd->type == MTD_ABSENT)
	325	return;
	326
71a928c0	327	list_for_each_entry(tr, &blktrans_majors, list)
1da177e4	328	tr->add_mtd(tr, mtd);
1da177e4 LT	329	}
	330
	331	static struct mtd_notifier blktrans_notifier = {
	332	.add = blktrans_notify_add,
	333	.remove = blktrans_notify_remove,
	334	};
97894cda	335
1da177e4 LT	336	int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
1da177e4 LT	337	{
f1332ba2 BH	338	struct mtd_info *mtd;
f1332ba2 BH	339	int ret;
1da177e4	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)
1122a26f CH	374	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
1122a26f 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)) {
6f4e137e	382	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
f1332ba2 BH	393	mtd_for_each_device(mtd)
	394	if (mtd->type != MTD_ABSENT)
	395	tr->add_mtd(tr, mtd);
1da177e4	396
48b19268	397	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	398
	399	return 0;
	400	}
	401
	402	int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
	403	{
71a928c0	404	struct mtd_blktrans_dev dev, next;
1da177e4	405
48b19268	406	mutex_lock(&mtd_table_mutex);
1da177e4 LT	407
1da177e4 LT	408	/* Clean up the kernel thread */
3e67fe45	409	kthread_stop(tr->blkcore_priv->thread);
1da177e4 LT	410
	411	/* Remove it from the list of active majors */
	412	list_del(&tr->list);
	413
71a928c0	414	list_for_each_entry_safe(dev, next, &tr->devs, list)
1da177e4	415	tr->remove_dev(dev);
1da177e4	416
1da177e4 LT	417	blk_cleanup_queue(tr->blkcore_priv->rq);
	418	unregister_blkdev(tr->major, tr->name);
	419
48b19268	420	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	421
	422	kfree(tr->blkcore_priv);
	423
373ebfbf	424	BUG_ON(!list_empty(&tr->devs));
1da177e4 LT	425	return 0;
	426	}
	427
	428	static void __exit mtd_blktrans_exit(void)
	429	{
	430	/* No race here -- if someone's currently in register_mtd_blktrans
	431	we're screwed anyway. */
	432	if (blktrans_notifier.list.next)
	433	unregister_mtd_user(&blktrans_notifier);
	434	}
	435
	436	module_exit(mtd_blktrans_exit);
	437
	438	EXPORT_SYMBOL_GPL(register_mtd_blktrans);
	439	EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
	440	EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
	441	EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
	442
	443	MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
	444	MODULE_LICENSE("GPL");
	445	MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");