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

/*
 * $Id: mtd_blkdevs.c,v 1.27 2005/11/07 11:14:20 gleixner Exp $
 *
 * (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/spinlock.h>
#include <linux/hdreg.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>

static LIST_HEAD(blktrans_majors);

extern struct mutex mtd_table_mutex;
extern struct mtd_info *mtd_table[];

struct mtd_blkcore_priv {
	struct completion thread_dead;
	int exiting;
	wait_queue_head_t thread_wq;
	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 = req->sector << 9 >> tr->blkshift;
	nsect = req->current_nr_sectors << 9 >> tr->blkshift;

	buf = req->buffer;

	if (!blk_fs_request(req))
		return 0;

	if (req->sector + req->current_nr_sectors > get_capacity(req->rq_disk))
		return 0;

	switch(rq_data_dir(req)) {
	case READ:
		for (; nsect > 0; nsect--, block++, buf += tr->blksize)
			if (tr->readsect(dev, block, buf))
				return 0;
		return 1;

	case WRITE:
		if (!tr->writesect)
			return 0;

		for (; nsect > 0; nsect--, block++, buf += tr->blksize)
			if (tr->writesect(dev, block, buf))
				return 0;
		return 1;

	default:
		printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
		return 0;
	}
}

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

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

	daemonize("%sd", tr->name);

	/* daemonize() doesn't do this for us since some kernel threads
	   actually want to deal with signals. We can't just call
	   exit_sighand() since that'll cause an oops when we finally
	   do exit. */
	spin_lock_irq(&current->sighand->siglock);
	sigfillset(&current->blocked);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	spin_lock_irq(rq->queue_lock);

	while (!tr->blkcore_priv->exiting) {
		struct request *req;
		struct mtd_blktrans_dev *dev;
		int res = 0;
		DECLARE_WAITQUEUE(wait, current);

		req = elv_next_request(rq);

		if (!req) {
			add_wait_queue(&tr->blkcore_priv->thread_wq, &wait);
			set_current_state(TASK_INTERRUPTIBLE);

			spin_unlock_irq(rq->queue_lock);

			schedule();
			remove_wait_queue(&tr->blkcore_priv->thread_wq, &wait);

			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);

		end_request(req, res);
	}
	spin_unlock_irq(rq->queue_lock);

	complete_and_exit(&tr->blkcore_priv->thread_dead, 0);
}

static void mtd_blktrans_request(struct request_queue *rq)
{
	struct mtd_blktrans_ops *tr = rq->queuedata;
	wake_up(&tr->blkcore_priv->thread_wq);
}


static int blktrans_open(struct inode *i, struct file *f)
{
	struct mtd_blktrans_dev *dev;
	struct mtd_blktrans_ops *tr;
	int ret = -ENODEV;

	dev = i->i_bdev->bd_disk->private_data;
	tr = dev->tr;

	if (!try_module_get(dev->mtd->owner))
		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--;
		module_put(dev->mtd->owner);
	out_tr:
		module_put(tr->owner);
	}
 out:
	return ret;
}

static int blktrans_release(struct inode *i, struct file *f)
{
	struct mtd_blktrans_dev *dev;
	struct mtd_blktrans_ops *tr;
	int ret = 0;

	dev = i->i_bdev->bd_disk->private_data;
	tr = dev->tr;

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

	if (!ret) {
		dev->mtd->usecount--;
		module_put(dev->mtd->owner);
		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 inode *inode, struct file *file,
			      unsigned int cmd, unsigned long arg)
{
	struct mtd_blktrans_dev *dev = inode->i_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;
	}
}

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

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

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

	list_for_each(this, &tr->devs) {
		struct mtd_blktrans_dev *d = list_entry(this, struct mtd_blktrans_dev, 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;
	}

	mutex_init(&new->lock);
	list_add_tail(&new->list, &tr->devs);
 added:
	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;

	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 list_head *this, *this2, *next;

	list_for_each(this, &blktrans_majors) {
		struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list);

		list_for_each_safe(this2, next, &tr->devs) {
			struct mtd_blktrans_dev *dev = list_entry(this2, struct mtd_blktrans_dev, list);

			if (dev->mtd == mtd)
				tr->remove_dev(dev);
		}
	}
}

static void blktrans_notify_add(struct mtd_info *mtd)
{
	struct list_head *this;

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

	list_for_each(this, &blktrans_majors) {
		struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, 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 = kmalloc(sizeof(*tr->blkcore_priv), GFP_KERNEL);
	if (!tr->blkcore_priv)
		return -ENOMEM;

	memset(tr->blkcore_priv, 0, sizeof(*tr->blkcore_priv));

	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);
	init_completion(&tr->blkcore_priv->thread_dead);
	init_waitqueue_head(&tr->blkcore_priv->thread_wq);

	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_hardsect_size(tr->blkcore_priv->rq, tr->blksize);
	tr->blkshift = ffs(tr->blksize) - 1;

	ret = kernel_thread(mtd_blktrans_thread, tr, CLONE_KERNEL);
	if (ret < 0) {
		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 list_head *this, *next;

	mutex_lock(&mtd_table_mutex);

	/* Clean up the kernel thread */
	tr->blkcore_priv->exiting = 1;
	wake_up(&tr->blkcore_priv->thread_wq);
	wait_for_completion(&tr->blkcore_priv->thread_dead);

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

	list_for_each_safe(this, next, &tr->devs) {
		struct mtd_blktrans_dev *dev = list_entry(this, struct mtd_blktrans_dev, 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	/*
97894cda	2	* $Id: mtd_blkdevs.c,v 1.27 2005/11/07 11:14:20 gleixner Exp $
1da177e4 LT	3	*
	4	* (C) 2003 David Woodhouse <dwmw2@infradead.org>
	5	*
	6	* Interface to Linux 2.5 block layer for MTD 'translation layers'.
	7	*
	8	*/
	9
	10	#include <linux/kernel.h>
	11	#include <linux/slab.h>
	12	#include <linux/module.h>
	13	#include <linux/list.h>
	14	#include <linux/fs.h>
	15	#include <linux/mtd/blktrans.h>
	16	#include <linux/mtd/mtd.h>
	17	#include <linux/blkdev.h>
	18	#include <linux/blkpg.h>
	19	#include <linux/spinlock.h>
	20	#include <linux/hdreg.h>
	21	#include <linux/init.h>
48b19268	22	#include <linux/mutex.h>
1da177e4	23	#include <asm/uaccess.h>
1da177e4 LT	24
	25	static LIST_HEAD(blktrans_majors);
	26
48b19268	27	extern struct mutex mtd_table_mutex;
1da177e4 LT	28	extern struct mtd_info *mtd_table[];
	29
	30	struct mtd_blkcore_priv {
	31	struct completion thread_dead;
	32	int exiting;
	33	wait_queue_head_t thread_wq;
	34	struct request_queue *rq;
	35	spinlock_t queue_lock;
	36	};
	37
	38	static int do_blktrans_request(struct mtd_blktrans_ops *tr,
	39	struct mtd_blktrans_dev *dev,
	40	struct request *req)
	41	{
	42	unsigned long block, nsect;
	43	char *buf;
	44
19187672 RP	45	block = req->sector << 9 >> tr->blkshift;
	46	nsect = req->current_nr_sectors << 9 >> tr->blkshift;
	47
1da177e4 LT	48	buf = req->buffer;
1da177e4 LT	49
4aff5e23	50	if (!blk_fs_request(req))
1da177e4 LT	51	return 0;
1da177e4 LT	52
19187672	53	if (req->sector + req->current_nr_sectors > get_capacity(req->rq_disk))
1da177e4 LT	54	return 0;
	55
	56	switch(rq_data_dir(req)) {
	57	case READ:
19187672	58	for (; nsect > 0; nsect--, block++, buf += tr->blksize)
1da177e4 LT	59	if (tr->readsect(dev, block, buf))
	60	return 0;
	61	return 1;
	62
	63	case WRITE:
	64	if (!tr->writesect)
	65	return 0;
	66
19187672	67	for (; nsect > 0; nsect--, block++, buf += tr->blksize)
1da177e4 LT	68	if (tr->writesect(dev, block, buf))
	69	return 0;
	70	return 1;
	71
	72	default:
9a292308	73	printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
1da177e4 LT	74	return 0;
	75	}
	76	}
	77
	78	static int mtd_blktrans_thread(void *arg)
	79	{
	80	struct mtd_blktrans_ops *tr = arg;
	81	struct request_queue *rq = tr->blkcore_priv->rq;
	82
	83	/* we might get involved when memory gets low, so use PF_MEMALLOC */
	84	current->flags \|= PF_MEMALLOC \| PF_NOFREEZE;
	85
	86	daemonize("%sd", tr->name);
	87
	88	/* daemonize() doesn't do this for us since some kernel threads
97894cda	89	actually want to deal with signals. We can't just call
1da177e4 LT	90	exit_sighand() since that'll cause an oops when we finally
	91	do exit. */
	92	spin_lock_irq(&current->sighand->siglock);
	93	sigfillset(&current->blocked);
	94	recalc_sigpending();
	95	spin_unlock_irq(&current->sighand->siglock);
	96
	97	spin_lock_irq(rq->queue_lock);
97894cda	98
1da177e4 LT	99	while (!tr->blkcore_priv->exiting) {
	100	struct request *req;
	101	struct mtd_blktrans_dev *dev;
	102	int res = 0;
	103	DECLARE_WAITQUEUE(wait, current);
	104
	105	req = elv_next_request(rq);
	106
	107	if (!req) {
	108	add_wait_queue(&tr->blkcore_priv->thread_wq, &wait);
	109	set_current_state(TASK_INTERRUPTIBLE);
	110
	111	spin_unlock_irq(rq->queue_lock);
	112
	113	schedule();
	114	remove_wait_queue(&tr->blkcore_priv->thread_wq, &wait);
	115
	116	spin_lock_irq(rq->queue_lock);
	117
	118	continue;
	119	}
	120
	121	dev = req->rq_disk->private_data;
	122	tr = dev->tr;
	123
	124	spin_unlock_irq(rq->queue_lock);
	125
48b19268	126	mutex_lock(&dev->lock);
1da177e4	127	res = do_blktrans_request(tr, dev, req);
48b19268	128	mutex_unlock(&dev->lock);
1da177e4 LT	129
	130	spin_lock_irq(rq->queue_lock);
	131
	132	end_request(req, res);
	133	}
	134	spin_unlock_irq(rq->queue_lock);
	135
	136	complete_and_exit(&tr->blkcore_priv->thread_dead, 0);
	137	}
	138
	139	static void mtd_blktrans_request(struct request_queue *rq)
	140	{
	141	struct mtd_blktrans_ops *tr = rq->queuedata;
	142	wake_up(&tr->blkcore_priv->thread_wq);
	143	}
	144
	145
	146	static int blktrans_open(struct inode i, struct file f)
	147	{
	148	struct mtd_blktrans_dev *dev;
	149	struct mtd_blktrans_ops *tr;
	150	int ret = -ENODEV;
	151
	152	dev = i->i_bdev->bd_disk->private_data;
	153	tr = dev->tr;
	154
	155	if (!try_module_get(dev->mtd->owner))
	156	goto out;
	157
	158	if (!try_module_get(tr->owner))
	159	goto out_tr;
	160
97894cda	161	/* FIXME: Locking. A hot pluggable device can go away
1da177e4 LT	162	(del_mtd_device can be called for it) without its module
	163	being unloaded. */
	164	dev->mtd->usecount++;
	165
	166	ret = 0;
	167	if (tr->open && (ret = tr->open(dev))) {
	168	dev->mtd->usecount--;
	169	module_put(dev->mtd->owner);
	170	out_tr:
	171	module_put(tr->owner);
	172	}
	173	out:
	174	return ret;
	175	}
	176
	177	static int blktrans_release(struct inode i, struct file f)
	178	{
	179	struct mtd_blktrans_dev *dev;
	180	struct mtd_blktrans_ops *tr;
	181	int ret = 0;
	182
	183	dev = i->i_bdev->bd_disk->private_data;
	184	tr = dev->tr;
	185
	186	if (tr->release)
	187	ret = tr->release(dev);
	188
	189	if (!ret) {
	190	dev->mtd->usecount--;
	191	module_put(dev->mtd->owner);
	192	module_put(tr->owner);
	193	}
	194
	195	return ret;
	196	}
	197
a885c8c4 CH	198	static int blktrans_getgeo(struct block_device bdev, struct hd_geometry geo)
	199	{
	200	struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data;
	201
	202	if (dev->tr->getgeo)
	203	return dev->tr->getgeo(dev, geo);
	204	return -ENOTTY;
	205	}
1da177e4	206
97894cda	207	static int blktrans_ioctl(struct inode inode, struct file file,
1da177e4 LT	208	unsigned int cmd, unsigned long arg)
	209	{
	210	struct mtd_blktrans_dev *dev = inode->i_bdev->bd_disk->private_data;
	211	struct mtd_blktrans_ops *tr = dev->tr;
	212
	213	switch (cmd) {
	214	case BLKFLSBUF:
	215	if (tr->flush)
	216	return tr->flush(dev);
	217	/* The core code did the work, we had nothing to do. */
	218	return 0;
1da177e4 LT	219	default:
	220	return -ENOTTY;
	221	}
	222	}
	223
	224	struct block_device_operations mtd_blktrans_ops = {
	225	.owner = THIS_MODULE,
	226	.open = blktrans_open,
	227	.release = blktrans_release,
	228	.ioctl = blktrans_ioctl,
a885c8c4	229	.getgeo = blktrans_getgeo,
1da177e4 LT	230	};
	231
	232	int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
	233	{
	234	struct mtd_blktrans_ops *tr = new->tr;
	235	struct list_head *this;
	236	int last_devnum = -1;
	237	struct gendisk *gd;
	238
48b19268 IM	239	if (!!mutex_trylock(&mtd_table_mutex)) {
48b19268 IM	240	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	241	BUG();
	242	}
	243
	244	list_for_each(this, &tr->devs) {
	245	struct mtd_blktrans_dev *d = list_entry(this, struct mtd_blktrans_dev, list);
	246	if (new->devnum == -1) {
	247	/* Use first free number */
	248	if (d->devnum != last_devnum+1) {
	249	/* Found a free devnum. Plug it in here */
	250	new->devnum = last_devnum+1;
	251	list_add_tail(&new->list, &d->list);
	252	goto added;
	253	}
	254	} else if (d->devnum == new->devnum) {
	255	/* Required number taken */
	256	return -EBUSY;
	257	} else if (d->devnum > new->devnum) {
	258	/* Required number was free */
	259	list_add_tail(&new->list, &d->list);
	260	goto added;
97894cda	261	}
1da177e4 LT	262	last_devnum = d->devnum;
	263	}
	264	if (new->devnum == -1)
	265	new->devnum = last_devnum+1;
	266
	267	if ((new->devnum << tr->part_bits) > 256) {
	268	return -EBUSY;
	269	}
	270
48b19268	271	mutex_init(&new->lock);
1da177e4 LT	272	list_add_tail(&new->list, &tr->devs);
	273	added:
	274	if (!tr->writesect)
	275	new->readonly = 1;
	276
	277	gd = alloc_disk(1 << tr->part_bits);
	278	if (!gd) {
	279	list_del(&new->list);
	280	return -ENOMEM;
	281	}
	282	gd->major = tr->major;
	283	gd->first_minor = (new->devnum) << tr->part_bits;
	284	gd->fops = &mtd_blktrans_ops;
97894cda	285
65a8de36 TP	286	if (tr->part_bits)
	287	if (new->devnum < 26)
	288	snprintf(gd->disk_name, sizeof(gd->disk_name),
	289	"%s%c", tr->name, 'a' + new->devnum);
	290	else
	291	snprintf(gd->disk_name, sizeof(gd->disk_name),
	292	"%s%c%c", tr->name,
	293	'a' - 1 + new->devnum / 26,
	294	'a' + new->devnum % 26);
	295	else
	296	snprintf(gd->disk_name, sizeof(gd->disk_name),
	297	"%s%d", tr->name, new->devnum);
1da177e4 LT	298
	299	/* 2.5 has capacity in units of 512 bytes while still
	300	having BLOCK_SIZE_BITS set to 10. Just to keep us amused. */
19187672	301	set_capacity(gd, (new->size * tr->blksize) >> 9);
1da177e4 LT	302
	303	gd->private_data = new;
	304	new->blkcore_priv = gd;
	305	gd->queue = tr->blkcore_priv->rq;
	306
	307	if (new->readonly)
	308	set_disk_ro(gd, 1);
	309
	310	add_disk(gd);
97894cda	311
1da177e4 LT	312	return 0;
	313	}
	314
	315	int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
	316	{
48b19268 IM	317	if (!!mutex_trylock(&mtd_table_mutex)) {
48b19268 IM	318	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	319	BUG();
	320	}
	321
	322	list_del(&old->list);
	323
	324	del_gendisk(old->blkcore_priv);
	325	put_disk(old->blkcore_priv);
97894cda	326
1da177e4 LT	327	return 0;
	328	}
	329
	330	static void blktrans_notify_remove(struct mtd_info *mtd)
	331	{
	332	struct list_head this, this2, *next;
	333
	334	list_for_each(this, &blktrans_majors) {
	335	struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list);
	336
	337	list_for_each_safe(this2, next, &tr->devs) {
	338	struct mtd_blktrans_dev *dev = list_entry(this2, struct mtd_blktrans_dev, list);
	339
	340	if (dev->mtd == mtd)
	341	tr->remove_dev(dev);
	342	}
	343	}
	344	}
	345
	346	static void blktrans_notify_add(struct mtd_info *mtd)
	347	{
	348	struct list_head *this;
	349
	350	if (mtd->type == MTD_ABSENT)
	351	return;
	352
	353	list_for_each(this, &blktrans_majors) {
	354	struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list);
	355
	356	tr->add_mtd(tr, mtd);
	357	}
	358
	359	}
	360
	361	static struct mtd_notifier blktrans_notifier = {
	362	.add = blktrans_notify_add,
	363	.remove = blktrans_notify_remove,
	364	};
97894cda	365
1da177e4 LT	366	int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
	367	{
	368	int ret, i;
	369
97894cda	370	/* Register the notifier if/when the first device type is
1da177e4 LT	371	registered, to prevent the link/init ordering from fucking
	372	us over. */
	373	if (!blktrans_notifier.list.next)
	374	register_mtd_user(&blktrans_notifier);
	375
	376	tr->blkcore_priv = kmalloc(sizeof(*tr->blkcore_priv), GFP_KERNEL);
	377	if (!tr->blkcore_priv)
	378	return -ENOMEM;
	379
	380	memset(tr->blkcore_priv, 0, sizeof(*tr->blkcore_priv));
	381
48b19268	382	mutex_lock(&mtd_table_mutex);
1da177e4 LT	383
	384	ret = register_blkdev(tr->major, tr->name);
	385	if (ret) {
	386	printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
	387	tr->name, tr->major, ret);
	388	kfree(tr->blkcore_priv);
48b19268	389	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	390	return ret;
	391	}
	392	spin_lock_init(&tr->blkcore_priv->queue_lock);
	393	init_completion(&tr->blkcore_priv->thread_dead);
	394	init_waitqueue_head(&tr->blkcore_priv->thread_wq);
	395
	396	tr->blkcore_priv->rq = blk_init_queue(mtd_blktrans_request, &tr->blkcore_priv->queue_lock);
	397	if (!tr->blkcore_priv->rq) {
	398	unregister_blkdev(tr->major, tr->name);
	399	kfree(tr->blkcore_priv);
48b19268	400	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	401	return -ENOMEM;
	402	}
	403
	404	tr->blkcore_priv->rq->queuedata = tr;
19187672 RP	405	blk_queue_hardsect_size(tr->blkcore_priv->rq, tr->blksize);
19187672 RP	406	tr->blkshift = ffs(tr->blksize) - 1;
1da177e4 LT	407
	408	ret = kernel_thread(mtd_blktrans_thread, tr, CLONE_KERNEL);
	409	if (ret < 0) {
	410	blk_cleanup_queue(tr->blkcore_priv->rq);
	411	unregister_blkdev(tr->major, tr->name);
	412	kfree(tr->blkcore_priv);
48b19268	413	mutex_unlock(&mtd_table_mutex);
1da177e4	414	return ret;
97894cda	415	}
1da177e4	416
1da177e4 LT	417	INIT_LIST_HEAD(&tr->devs);
	418	list_add(&tr->list, &blktrans_majors);
	419
	420	for (i=0; i<MAX_MTD_DEVICES; i++) {
	421	if (mtd_table[i] && mtd_table[i]->type != MTD_ABSENT)
	422	tr->add_mtd(tr, mtd_table[i]);
	423	}
	424
48b19268	425	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	426
	427	return 0;
	428	}
	429
	430	int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
	431	{
	432	struct list_head this, next;
	433
48b19268	434	mutex_lock(&mtd_table_mutex);
1da177e4 LT	435
	436	/* Clean up the kernel thread */
	437	tr->blkcore_priv->exiting = 1;
	438	wake_up(&tr->blkcore_priv->thread_wq);
	439	wait_for_completion(&tr->blkcore_priv->thread_dead);
	440
	441	/* Remove it from the list of active majors */
	442	list_del(&tr->list);
	443
	444	list_for_each_safe(this, next, &tr->devs) {
	445	struct mtd_blktrans_dev *dev = list_entry(this, struct mtd_blktrans_dev, list);
	446	tr->remove_dev(dev);
	447	}
	448
1da177e4 LT	449	blk_cleanup_queue(tr->blkcore_priv->rq);
	450	unregister_blkdev(tr->major, tr->name);
	451
48b19268	452	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	453
	454	kfree(tr->blkcore_priv);
	455
373ebfbf	456	BUG_ON(!list_empty(&tr->devs));
1da177e4 LT	457	return 0;
	458	}
	459
	460	static void __exit mtd_blktrans_exit(void)
	461	{
	462	/* No race here -- if someone's currently in register_mtd_blktrans
	463	we're screwed anyway. */
	464	if (blktrans_notifier.list.next)
	465	unregister_mtd_user(&blktrans_notifier);
	466	}
	467
	468	module_exit(mtd_blktrans_exit);
	469
	470	EXPORT_SYMBOL_GPL(register_mtd_blktrans);
	471	EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
	472	EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
	473	EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
	474
	475	MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
	476	MODULE_LICENSE("GPL");
	477	MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");