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