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

/*
 * $Id: mtdcore.c,v 1.47 2005/11/07 11:14:20 gleixner Exp $
 *
 * Core registration and callback routines for MTD
 * drivers and users.
 *
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/init.h>
#include <linux/mtd/compatmac.h>
#include <linux/proc_fs.h>

#include <linux/mtd/mtd.h>

/* These are exported solely for the purpose of mtd_blkdevs.c. You
   should not use them for _anything_ else */
DEFINE_MUTEX(mtd_table_mutex);
struct mtd_info *mtd_table[MAX_MTD_DEVICES];

EXPORT_SYMBOL_GPL(mtd_table_mutex);
EXPORT_SYMBOL_GPL(mtd_table);

static LIST_HEAD(mtd_notifiers);

/**
 *	add_mtd_device - register an MTD device
 *	@mtd: pointer to new MTD device info structure
 *
 *	Add a device to the list of MTD devices present in the system, and
 *	notify each currently active MTD 'user' of its arrival. Returns
 *	zero on success or 1 on failure, which currently will only happen
 *	if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
 */

int add_mtd_device(struct mtd_info *mtd)
{
	int i;

	BUG_ON(mtd->writesize == 0);
	mutex_lock(&mtd_table_mutex);

	for (i=0; i < MAX_MTD_DEVICES; i++)
		if (!mtd_table[i]) {
			struct list_head *this;

			mtd_table[i] = mtd;
			mtd->index = i;
			mtd->usecount = 0;

			DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
			/* No need to get a refcount on the module containing
			   the notifier, since we hold the mtd_table_mutex */
			list_for_each(this, &mtd_notifiers) {
				struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
				not->add(mtd);
			}

			mutex_unlock(&mtd_table_mutex);
			/* We _know_ we aren't being removed, because
			   our caller is still holding us here. So none
			   of this try_ nonsense, and no bitching about it
			   either. :) */
			__module_get(THIS_MODULE);
			return 0;
		}

	mutex_unlock(&mtd_table_mutex);
	return 1;
}

/**
 *	del_mtd_device - unregister an MTD device
 *	@mtd: pointer to MTD device info structure
 *
 *	Remove a device from the list of MTD devices present in the system,
 *	and notify each currently active MTD 'user' of its departure.
 *	Returns zero on success or 1 on failure, which currently will happen
 *	if the requested device does not appear to be present in the list.
 */

int del_mtd_device (struct mtd_info *mtd)
{
	int ret;

	mutex_lock(&mtd_table_mutex);

	if (mtd_table[mtd->index] != mtd) {
		ret = -ENODEV;
	} else if (mtd->usecount) {
		printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
		       mtd->index, mtd->name, mtd->usecount);
		ret = -EBUSY;
	} else {
		struct list_head *this;

		/* No need to get a refcount on the module containing
		   the notifier, since we hold the mtd_table_mutex */
		list_for_each(this, &mtd_notifiers) {
			struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
			not->remove(mtd);
		}

		mtd_table[mtd->index] = NULL;

		module_put(THIS_MODULE);
		ret = 0;
	}

	mutex_unlock(&mtd_table_mutex);
	return ret;
}

/**
 *	register_mtd_user - register a 'user' of MTD devices.
 *	@new: pointer to notifier info structure
 *
 *	Registers a pair of callbacks function to be called upon addition
 *	or removal of MTD devices. Causes the 'add' callback to be immediately
 *	invoked for each MTD device currently present in the system.
 */

void register_mtd_user (struct mtd_notifier *new)
{
	int i;

	mutex_lock(&mtd_table_mutex);

	list_add(&new->list, &mtd_notifiers);

 	__module_get(THIS_MODULE);

	for (i=0; i< MAX_MTD_DEVICES; i++)
		if (mtd_table[i])
			new->add(mtd_table[i]);

	mutex_unlock(&mtd_table_mutex);
}

/**
 *	unregister_mtd_user - unregister a 'user' of MTD devices.
 *	@old: pointer to notifier info structure
 *
 *	Removes a callback function pair from the list of 'users' to be
 *	notified upon addition or removal of MTD devices. Causes the
 *	'remove' callback to be immediately invoked for each MTD device
 *	currently present in the system.
 */

int unregister_mtd_user (struct mtd_notifier *old)
{
	int i;

	mutex_lock(&mtd_table_mutex);

	module_put(THIS_MODULE);

	for (i=0; i< MAX_MTD_DEVICES; i++)
		if (mtd_table[i])
			old->remove(mtd_table[i]);

	list_del(&old->list);
	mutex_unlock(&mtd_table_mutex);
	return 0;
}


/**
 *	get_mtd_device - obtain a validated handle for an MTD device
 *	@mtd: last known address of the required MTD device
 *	@num: internal device number of the required MTD device
 *
 *	Given a number and NULL address, return the num'th entry in the device
 *	table, if any.	Given an address and num == -1, search the device table
 *	for a device with that address and return if it's still present. Given
 *	both, return the num'th driver only if its address matches. Return NULL
 *	if not.
 */

struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
{
	struct mtd_info *ret = NULL;
	int i;

	mutex_lock(&mtd_table_mutex);

	if (num == -1) {
		for (i=0; i< MAX_MTD_DEVICES; i++)
			if (mtd_table[i] == mtd)
				ret = mtd_table[i];
	} else if (num < MAX_MTD_DEVICES) {
		ret = mtd_table[num];
		if (mtd && mtd != ret)
			ret = NULL;
	}

	if (ret && !try_module_get(ret->owner))
		ret = NULL;

	if (ret)
		ret->usecount++;

	mutex_unlock(&mtd_table_mutex);
	return ret;
}

void put_mtd_device(struct mtd_info *mtd)
{
	int c;

	mutex_lock(&mtd_table_mutex);
	c = --mtd->usecount;
	mutex_unlock(&mtd_table_mutex);
	BUG_ON(c < 0);

	module_put(mtd->owner);
}

/* default_mtd_writev - default mtd writev method for MTD devices that
 *			dont implement their own
 */

int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
		       unsigned long count, loff_t to, size_t *retlen)
{
	unsigned long i;
	size_t totlen = 0, thislen;
	int ret = 0;

	if(!mtd->write) {
		ret = -EROFS;
	} else {
		for (i=0; i<count; i++) {
			if (!vecs[i].iov_len)
				continue;
			ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
			totlen += thislen;
			if (ret || thislen != vecs[i].iov_len)
				break;
			to += vecs[i].iov_len;
		}
	}
	if (retlen)
		*retlen = totlen;
	return ret;
}

EXPORT_SYMBOL(add_mtd_device);
EXPORT_SYMBOL(del_mtd_device);
EXPORT_SYMBOL(get_mtd_device);
EXPORT_SYMBOL(put_mtd_device);
EXPORT_SYMBOL(register_mtd_user);
EXPORT_SYMBOL(unregister_mtd_user);
EXPORT_SYMBOL(default_mtd_writev);

#ifdef CONFIG_PROC_FS

/*====================================================================*/
/* Support for /proc/mtd */

static struct proc_dir_entry *proc_mtd;

static inline int mtd_proc_info (char *buf, int i)
{
	struct mtd_info *this = mtd_table[i];

	if (!this)
		return 0;

	return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
		       this->erasesize, this->name);
}

static int mtd_read_proc (char *page, char **start, off_t off, int count,
			  int *eof, void *data_unused)
{
	int len, l, i;
        off_t   begin = 0;

	mutex_lock(&mtd_table_mutex);

	len = sprintf(page, "dev:    size   erasesize  name\n");
        for (i=0; i< MAX_MTD_DEVICES; i++) {

                l = mtd_proc_info(page + len, i);
                len += l;
                if (len+begin > off+count)
                        goto done;
                if (len+begin < off) {
                        begin += len;
                        len = 0;
                }
        }

        *eof = 1;

done:
	mutex_unlock(&mtd_table_mutex);
        if (off >= len+begin)
                return 0;
        *start = page + (off-begin);
        return ((count < begin+len-off) ? count : begin+len-off);
}

/*====================================================================*/
/* Init code */

static int __init init_mtd(void)
{
	if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
		proc_mtd->read_proc = mtd_read_proc;
	return 0;
}

static void __exit cleanup_mtd(void)
{
        if (proc_mtd)
		remove_proc_entry( "mtd", NULL);
}

module_init(init_mtd);
module_exit(cleanup_mtd);

#endif /* CONFIG_PROC_FS */


MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Core MTD registration and access routines");
Commit	Line	Data
1da177e4	1	/*
97894cda	2	* $Id: mtdcore.c,v 1.47 2005/11/07 11:14:20 gleixner Exp $
1da177e4 LT	3	*
	4	* Core registration and callback routines for MTD
	5	* drivers and users.
	6	*
	7	*/
	8
	9	#include <linux/config.h>
	10	#include <linux/module.h>
	11	#include <linux/kernel.h>
	12	#include <linux/sched.h>
	13	#include <linux/ptrace.h>
	14	#include <linux/slab.h>
	15	#include <linux/string.h>
	16	#include <linux/timer.h>
	17	#include <linux/major.h>
	18	#include <linux/fs.h>
	19	#include <linux/ioctl.h>
	20	#include <linux/init.h>
	21	#include <linux/mtd/compatmac.h>
1da177e4	22	#include <linux/proc_fs.h>
1da177e4 LT	23
	24	#include <linux/mtd/mtd.h>
	25
97894cda	26	/* These are exported solely for the purpose of mtd_blkdevs.c. You
1da177e4	27	should not use them for _anything_ else */
48b19268	28	DEFINE_MUTEX(mtd_table_mutex);
1da177e4 LT	29	struct mtd_info *mtd_table[MAX_MTD_DEVICES];
	30
	31	EXPORT_SYMBOL_GPL(mtd_table_mutex);
	32	EXPORT_SYMBOL_GPL(mtd_table);
	33
	34	static LIST_HEAD(mtd_notifiers);
	35
	36	/**
	37	* add_mtd_device - register an MTD device
	38	* @mtd: pointer to new MTD device info structure
	39	*
	40	* Add a device to the list of MTD devices present in the system, and
	41	* notify each currently active MTD 'user' of its arrival. Returns
	42	* zero on success or 1 on failure, which currently will only happen
	43	* if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
	44	*/
	45
	46	int add_mtd_device(struct mtd_info *mtd)
	47	{
	48	int i;
	49
783ed81f	50	BUG_ON(mtd->writesize == 0);
48b19268	51	mutex_lock(&mtd_table_mutex);
1da177e4 LT	52
	53	for (i=0; i < MAX_MTD_DEVICES; i++)
	54	if (!mtd_table[i]) {
	55	struct list_head *this;
	56
	57	mtd_table[i] = mtd;
	58	mtd->index = i;
	59	mtd->usecount = 0;
	60
	61	DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
	62	/* No need to get a refcount on the module containing
	63	the notifier, since we hold the mtd_table_mutex */
	64	list_for_each(this, &mtd_notifiers) {
	65	struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
	66	not->add(mtd);
	67	}
97894cda	68
48b19268	69	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	70	/* We _know_ we aren't being removed, because
	71	our caller is still holding us here. So none
	72	of this try_ nonsense, and no bitching about it
	73	either. :) */
	74	__module_get(THIS_MODULE);
	75	return 0;
	76	}
97894cda	77
48b19268	78	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	79	return 1;
	80	}
	81
	82	/**
	83	* del_mtd_device - unregister an MTD device
	84	* @mtd: pointer to MTD device info structure
	85	*
	86	* Remove a device from the list of MTD devices present in the system,
	87	* and notify each currently active MTD 'user' of its departure.
	88	* Returns zero on success or 1 on failure, which currently will happen
	89	* if the requested device does not appear to be present in the list.
	90	*/
	91
	92	int del_mtd_device (struct mtd_info *mtd)
	93	{
	94	int ret;
97894cda	95
48b19268	96	mutex_lock(&mtd_table_mutex);
1da177e4 LT	97
	98	if (mtd_table[mtd->index] != mtd) {
	99	ret = -ENODEV;
	100	} else if (mtd->usecount) {
97894cda	101	printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
1da177e4 LT	102	mtd->index, mtd->name, mtd->usecount);
	103	ret = -EBUSY;
	104	} else {
	105	struct list_head *this;
	106
	107	/* No need to get a refcount on the module containing
	108	the notifier, since we hold the mtd_table_mutex */
	109	list_for_each(this, &mtd_notifiers) {
	110	struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
	111	not->remove(mtd);
	112	}
	113
	114	mtd_table[mtd->index] = NULL;
	115
	116	module_put(THIS_MODULE);
	117	ret = 0;
	118	}
	119
48b19268	120	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	121	return ret;
	122	}
	123
	124	/**
	125	* register_mtd_user - register a 'user' of MTD devices.
	126	* @new: pointer to notifier info structure
	127	*
	128	* Registers a pair of callbacks function to be called upon addition
	129	* or removal of MTD devices. Causes the 'add' callback to be immediately
	130	* invoked for each MTD device currently present in the system.
	131	*/
	132
	133	void register_mtd_user (struct mtd_notifier *new)
	134	{
	135	int i;
	136
48b19268	137	mutex_lock(&mtd_table_mutex);
1da177e4 LT	138
	139	list_add(&new->list, &mtd_notifiers);
	140
	141	__module_get(THIS_MODULE);
97894cda	142
1da177e4 LT	143	for (i=0; i< MAX_MTD_DEVICES; i++)
	144	if (mtd_table[i])
	145	new->add(mtd_table[i]);
	146
48b19268	147	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	148	}
	149
	150	/**
49450795 AB	151	* unregister_mtd_user - unregister a 'user' of MTD devices.
49450795 AB	152	* @old: pointer to notifier info structure
1da177e4 LT	153	*
	154	* Removes a callback function pair from the list of 'users' to be
	155	* notified upon addition or removal of MTD devices. Causes the
	156	* 'remove' callback to be immediately invoked for each MTD device
	157	* currently present in the system.
	158	*/
	159
	160	int unregister_mtd_user (struct mtd_notifier *old)
	161	{
	162	int i;
	163
48b19268	164	mutex_lock(&mtd_table_mutex);
1da177e4 LT	165
	166	module_put(THIS_MODULE);
	167
	168	for (i=0; i< MAX_MTD_DEVICES; i++)
	169	if (mtd_table[i])
	170	old->remove(mtd_table[i]);
97894cda	171
1da177e4	172	list_del(&old->list);
48b19268	173	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	174	return 0;
	175	}
	176
	177
	178	/**
	179	* get_mtd_device - obtain a validated handle for an MTD device
	180	* @mtd: last known address of the required MTD device
	181	* @num: internal device number of the required MTD device
	182	*
	183	* Given a number and NULL address, return the num'th entry in the device
	184	* table, if any. Given an address and num == -1, search the device table
	185	* for a device with that address and return if it's still present. Given
	186	* both, return the num'th driver only if its address matches. Return NULL
	187	* if not.
	188	*/
97894cda	189
1da177e4 LT	190	struct mtd_info get_mtd_device(struct mtd_info mtd, int num)
	191	{
	192	struct mtd_info *ret = NULL;
	193	int i;
	194
48b19268	195	mutex_lock(&mtd_table_mutex);
1da177e4 LT	196
	197	if (num == -1) {
	198	for (i=0; i< MAX_MTD_DEVICES; i++)
	199	if (mtd_table[i] == mtd)
	200	ret = mtd_table[i];
	201	} else if (num < MAX_MTD_DEVICES) {
	202	ret = mtd_table[num];
	203	if (mtd && mtd != ret)
	204	ret = NULL;
	205	}
	206
	207	if (ret && !try_module_get(ret->owner))
	208	ret = NULL;
	209
	210	if (ret)
	211	ret->usecount++;
	212
48b19268	213	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	214	return ret;
	215	}
	216
	217	void put_mtd_device(struct mtd_info *mtd)
	218	{
	219	int c;
	220
48b19268	221	mutex_lock(&mtd_table_mutex);
1da177e4	222	c = --mtd->usecount;
48b19268	223	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	224	BUG_ON(c < 0);
	225
	226	module_put(mtd->owner);
	227	}
	228
	229	/* default_mtd_writev - default mtd writev method for MTD devices that
	230	* dont implement their own
	231	*/
	232
	233	int default_mtd_writev(struct mtd_info mtd, const struct kvec vecs,
	234	unsigned long count, loff_t to, size_t *retlen)
	235	{
	236	unsigned long i;
	237	size_t totlen = 0, thislen;
	238	int ret = 0;
	239
	240	if(!mtd->write) {
	241	ret = -EROFS;
	242	} else {
	243	for (i=0; i<count; i++) {
	244	if (!vecs[i].iov_len)
	245	continue;
	246	ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
	247	totlen += thislen;
	248	if (ret \|\| thislen != vecs[i].iov_len)
	249	break;
	250	to += vecs[i].iov_len;
	251	}
	252	}
	253	if (retlen)
	254	*retlen = totlen;
	255	return ret;
	256	}
	257
1da177e4 LT	258	EXPORT_SYMBOL(add_mtd_device);
	259	EXPORT_SYMBOL(del_mtd_device);
	260	EXPORT_SYMBOL(get_mtd_device);
	261	EXPORT_SYMBOL(put_mtd_device);
	262	EXPORT_SYMBOL(register_mtd_user);
	263	EXPORT_SYMBOL(unregister_mtd_user);
	264	EXPORT_SYMBOL(default_mtd_writev);
1da177e4	265
2d2dce0e PM	266	#ifdef CONFIG_PROC_FS
2d2dce0e PM	267
1da177e4 LT	268	/====================================================================/
	269	/* Support for /proc/mtd */
	270
1da177e4 LT	271	static struct proc_dir_entry *proc_mtd;
	272
	273	static inline int mtd_proc_info (char *buf, int i)
	274	{
	275	struct mtd_info *this = mtd_table[i];
	276
	277	if (!this)
	278	return 0;
	279
	280	return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
	281	this->erasesize, this->name);
	282	}
	283
	284	static int mtd_read_proc (char page, char *start, off_t off, int count,
	285	int eof, void data_unused)
	286	{
	287	int len, l, i;
	288	off_t begin = 0;
	289
48b19268	290	mutex_lock(&mtd_table_mutex);
1da177e4 LT	291
	292	len = sprintf(page, "dev: size erasesize name\n");
	293	for (i=0; i< MAX_MTD_DEVICES; i++) {
	294
	295	l = mtd_proc_info(page + len, i);
	296	len += l;
	297	if (len+begin > off+count)
	298	goto done;
	299	if (len+begin < off) {
	300	begin += len;
	301	len = 0;
	302	}
	303	}
	304
	305	*eof = 1;
	306
	307	done:
48b19268	308	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	309	if (off >= len+begin)
	310	return 0;
	311	*start = page + (off-begin);
	312	return ((count < begin+len-off) ? count : begin+len-off);
	313	}
	314
1da177e4 LT	315	/====================================================================/
	316	/* Init code */
	317
	318	static int __init init_mtd(void)
	319	{
1da177e4 LT	320	if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
1da177e4 LT	321	proc_mtd->read_proc = mtd_read_proc;
1da177e4 LT	322	return 0;
	323	}
	324
	325	static void __exit cleanup_mtd(void)
	326	{
1da177e4 LT	327	if (proc_mtd)
1da177e4 LT	328	remove_proc_entry( "mtd", NULL);
1da177e4 LT	329	}
	330
	331	module_init(init_mtd);
	332	module_exit(cleanup_mtd);
	333
2d2dce0e PM	334	#endif /* CONFIG_PROC_FS */
2d2dce0e PM	335
1da177e4 LT	336
	337	MODULE_LICENSE("GPL");
	338	MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
	339	MODULE_DESCRIPTION("Core MTD registration and access routines");