[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;

			/* Some chips always power up locked. Unlock them now */
			if ((mtd->flags & MTD_WRITEABLE)
			    && (mtd->flags & MTD_STUPID_LOCK) && mtd->unlock) {
				if (mtd->unlock(mtd, 0, mtd->size))
					printk(KERN_WARNING
					       "%s: unlock failed, "
					       "writes may not work\n",
					       mtd->name);
			}

			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
187ef152 HS	60	/* Some chips always power up locked. Unlock them now */
	61	if ((mtd->flags & MTD_WRITEABLE)
	62	&& (mtd->flags & MTD_STUPID_LOCK) && mtd->unlock) {
	63	if (mtd->unlock(mtd, 0, mtd->size))
	64	printk(KERN_WARNING
	65	"%s: unlock failed, "
	66	"writes may not work\n",
	67	mtd->name);
	68	}
	69
1da177e4 LT	70	DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name);
	71	/* No need to get a refcount on the module containing
	72	the notifier, since we hold the mtd_table_mutex */
	73	list_for_each(this, &mtd_notifiers) {
	74	struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
	75	not->add(mtd);
	76	}
97894cda	77
48b19268	78	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	79	/* We _know_ we aren't being removed, because
	80	our caller is still holding us here. So none
	81	of this try_ nonsense, and no bitching about it
	82	either. :) */
	83	__module_get(THIS_MODULE);
	84	return 0;
	85	}
97894cda	86
48b19268	87	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	88	return 1;
	89	}
	90
	91	/**
	92	* del_mtd_device - unregister an MTD device
	93	* @mtd: pointer to MTD device info structure
	94	*
	95	* Remove a device from the list of MTD devices present in the system,
	96	* and notify each currently active MTD 'user' of its departure.
	97	* Returns zero on success or 1 on failure, which currently will happen
	98	* if the requested device does not appear to be present in the list.
	99	*/
	100
	101	int del_mtd_device (struct mtd_info *mtd)
	102	{
	103	int ret;
97894cda	104
48b19268	105	mutex_lock(&mtd_table_mutex);
1da177e4 LT	106
	107	if (mtd_table[mtd->index] != mtd) {
	108	ret = -ENODEV;
	109	} else if (mtd->usecount) {
97894cda	110	printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
1da177e4 LT	111	mtd->index, mtd->name, mtd->usecount);
	112	ret = -EBUSY;
	113	} else {
	114	struct list_head *this;
	115
	116	/* No need to get a refcount on the module containing
	117	the notifier, since we hold the mtd_table_mutex */
	118	list_for_each(this, &mtd_notifiers) {
	119	struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
	120	not->remove(mtd);
	121	}
	122
	123	mtd_table[mtd->index] = NULL;
	124
	125	module_put(THIS_MODULE);
	126	ret = 0;
	127	}
	128
48b19268	129	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	130	return ret;
	131	}
	132
	133	/**
	134	* register_mtd_user - register a 'user' of MTD devices.
	135	* @new: pointer to notifier info structure
	136	*
	137	* Registers a pair of callbacks function to be called upon addition
	138	* or removal of MTD devices. Causes the 'add' callback to be immediately
	139	* invoked for each MTD device currently present in the system.
	140	*/
	141
	142	void register_mtd_user (struct mtd_notifier *new)
	143	{
	144	int i;
	145
48b19268	146	mutex_lock(&mtd_table_mutex);
1da177e4 LT	147
	148	list_add(&new->list, &mtd_notifiers);
	149
	150	__module_get(THIS_MODULE);
97894cda	151
1da177e4 LT	152	for (i=0; i< MAX_MTD_DEVICES; i++)
	153	if (mtd_table[i])
	154	new->add(mtd_table[i]);
	155
48b19268	156	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	157	}
	158
	159	/**
49450795 AB	160	* unregister_mtd_user - unregister a 'user' of MTD devices.
49450795 AB	161	* @old: pointer to notifier info structure
1da177e4 LT	162	*
	163	* Removes a callback function pair from the list of 'users' to be
	164	* notified upon addition or removal of MTD devices. Causes the
	165	* 'remove' callback to be immediately invoked for each MTD device
	166	* currently present in the system.
	167	*/
	168
	169	int unregister_mtd_user (struct mtd_notifier *old)
	170	{
	171	int i;
	172
48b19268	173	mutex_lock(&mtd_table_mutex);
1da177e4 LT	174
	175	module_put(THIS_MODULE);
	176
	177	for (i=0; i< MAX_MTD_DEVICES; i++)
	178	if (mtd_table[i])
	179	old->remove(mtd_table[i]);
97894cda	180
1da177e4	181	list_del(&old->list);
48b19268	182	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	183	return 0;
	184	}
	185
	186
	187	/**
	188	* get_mtd_device - obtain a validated handle for an MTD device
	189	* @mtd: last known address of the required MTD device
	190	* @num: internal device number of the required MTD device
	191	*
	192	* Given a number and NULL address, return the num'th entry in the device
	193	* table, if any. Given an address and num == -1, search the device table
	194	* for a device with that address and return if it's still present. Given
	195	* both, return the num'th driver only if its address matches. Return NULL
	196	* if not.
	197	*/
97894cda	198
1da177e4 LT	199	struct mtd_info get_mtd_device(struct mtd_info mtd, int num)
	200	{
	201	struct mtd_info *ret = NULL;
	202	int i;
	203
48b19268	204	mutex_lock(&mtd_table_mutex);
1da177e4 LT	205
	206	if (num == -1) {
	207	for (i=0; i< MAX_MTD_DEVICES; i++)
	208	if (mtd_table[i] == mtd)
	209	ret = mtd_table[i];
	210	} else if (num < MAX_MTD_DEVICES) {
	211	ret = mtd_table[num];
	212	if (mtd && mtd != ret)
	213	ret = NULL;
	214	}
	215
	216	if (ret && !try_module_get(ret->owner))
	217	ret = NULL;
	218
	219	if (ret)
	220	ret->usecount++;
	221
48b19268	222	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	223	return ret;
	224	}
	225
	226	void put_mtd_device(struct mtd_info *mtd)
	227	{
	228	int c;
	229
48b19268	230	mutex_lock(&mtd_table_mutex);
1da177e4	231	c = --mtd->usecount;
48b19268	232	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	233	BUG_ON(c < 0);
	234
	235	module_put(mtd->owner);
	236	}
	237
	238	/* default_mtd_writev - default mtd writev method for MTD devices that
	239	* dont implement their own
	240	*/
	241
	242	int default_mtd_writev(struct mtd_info mtd, const struct kvec vecs,
	243	unsigned long count, loff_t to, size_t *retlen)
	244	{
	245	unsigned long i;
	246	size_t totlen = 0, thislen;
	247	int ret = 0;
	248
	249	if(!mtd->write) {
	250	ret = -EROFS;
	251	} else {
	252	for (i=0; i<count; i++) {
	253	if (!vecs[i].iov_len)
	254	continue;
	255	ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
	256	totlen += thislen;
	257	if (ret \|\| thislen != vecs[i].iov_len)
	258	break;
	259	to += vecs[i].iov_len;
	260	}
	261	}
	262	if (retlen)
	263	*retlen = totlen;
	264	return ret;
	265	}
	266
1da177e4 LT	267	EXPORT_SYMBOL(add_mtd_device);
	268	EXPORT_SYMBOL(del_mtd_device);
	269	EXPORT_SYMBOL(get_mtd_device);
	270	EXPORT_SYMBOL(put_mtd_device);
	271	EXPORT_SYMBOL(register_mtd_user);
	272	EXPORT_SYMBOL(unregister_mtd_user);
	273	EXPORT_SYMBOL(default_mtd_writev);
1da177e4	274
2d2dce0e PM	275	#ifdef CONFIG_PROC_FS
2d2dce0e PM	276
1da177e4 LT	277	/====================================================================/
	278	/* Support for /proc/mtd */
	279
1da177e4 LT	280	static struct proc_dir_entry *proc_mtd;
	281
	282	static inline int mtd_proc_info (char *buf, int i)
	283	{
	284	struct mtd_info *this = mtd_table[i];
	285
	286	if (!this)
	287	return 0;
	288
	289	return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size,
	290	this->erasesize, this->name);
	291	}
	292
	293	static int mtd_read_proc (char page, char *start, off_t off, int count,
	294	int eof, void data_unused)
	295	{
	296	int len, l, i;
	297	off_t begin = 0;
	298
48b19268	299	mutex_lock(&mtd_table_mutex);
1da177e4 LT	300
	301	len = sprintf(page, "dev: size erasesize name\n");
	302	for (i=0; i< MAX_MTD_DEVICES; i++) {
	303
	304	l = mtd_proc_info(page + len, i);
	305	len += l;
	306	if (len+begin > off+count)
	307	goto done;
	308	if (len+begin < off) {
	309	begin += len;
	310	len = 0;
	311	}
	312	}
	313
	314	*eof = 1;
	315
	316	done:
48b19268	317	mutex_unlock(&mtd_table_mutex);
1da177e4 LT	318	if (off >= len+begin)
	319	return 0;
	320	*start = page + (off-begin);
	321	return ((count < begin+len-off) ? count : begin+len-off);
	322	}
	323
1da177e4 LT	324	/====================================================================/
	325	/* Init code */
	326
	327	static int __init init_mtd(void)
	328	{
1da177e4 LT	329	if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
1da177e4 LT	330	proc_mtd->read_proc = mtd_read_proc;
1da177e4 LT	331	return 0;
	332	}
	333
	334	static void __exit cleanup_mtd(void)
	335	{
1da177e4 LT	336	if (proc_mtd)
1da177e4 LT	337	remove_proc_entry( "mtd", NULL);
1da177e4 LT	338	}
	339
	340	module_init(init_mtd);
	341	module_exit(cleanup_mtd);
	342
2d2dce0e PM	343	#endif /* CONFIG_PROC_FS */
2d2dce0e PM	344
1da177e4 LT	345
	346	MODULE_LICENSE("GPL");
	347	MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
	348	MODULE_DESCRIPTION("Core MTD registration and access routines");