[deliverable/linux.git] / drivers / mtd / devices / block2mtd.c

/*
 * block2mtd.c - create an mtd from a block device
 *
 * Copyright (C) 2001,2002	Simon Evans <spse@secret.org.uk>
 * Copyright (C) 2004-2006	Joern Engel <joern@wh.fh-wedel.de>
 *
 * Licence: GPL
 */
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/pagemap.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/mutex.h>
#include <linux/mount.h>
#include <linux/slab.h>

#define ERROR(fmt, args...) printk(KERN_ERR "block2mtd: " fmt "\n" , ## args)
#define INFO(fmt, args...) printk(KERN_INFO "block2mtd: " fmt "\n" , ## args)


/* Info for the block device */
struct block2mtd_dev {
	struct list_head list;
	struct block_device *blkdev;
	struct mtd_info mtd;
	struct mutex write_mutex;
};


/* Static info about the MTD, used in cleanup_module */
static LIST_HEAD(blkmtd_device_list);


static struct page *page_read(struct address_space *mapping, int index)
{
	return read_mapping_page(mapping, index, NULL);
}

/* erase a specified part of the device */
static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
{
	struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
	struct page *page;
	int index = to >> PAGE_SHIFT;	// page index
	int pages = len >> PAGE_SHIFT;
	u_long *p;
	u_long *max;

	while (pages) {
		page = page_read(mapping, index);
		if (!page)
			return -ENOMEM;
		if (IS_ERR(page))
			return PTR_ERR(page);

		max = page_address(page) + PAGE_SIZE;
		for (p=page_address(page); p<max; p++)
			if (*p != -1UL) {
				lock_page(page);
				memset(page_address(page), 0xff, PAGE_SIZE);
				set_page_dirty(page);
				unlock_page(page);
				break;
			}

		page_cache_release(page);
		pages--;
		index++;
	}
	return 0;
}
static int block2mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
{
	struct block2mtd_dev *dev = mtd->priv;
	size_t from = instr->addr;
	size_t len = instr->len;
	int err;

	instr->state = MTD_ERASING;
	mutex_lock(&dev->write_mutex);
	err = _block2mtd_erase(dev, from, len);
	mutex_unlock(&dev->write_mutex);
	if (err) {
		ERROR("erase failed err = %d", err);
		instr->state = MTD_ERASE_FAILED;
	} else
		instr->state = MTD_ERASE_DONE;

	mtd_erase_callback(instr);
	return err;
}


static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
		size_t *retlen, u_char *buf)
{
	struct block2mtd_dev *dev = mtd->priv;
	struct page *page;
	int index = from >> PAGE_SHIFT;
	int offset = from & (PAGE_SIZE-1);
	int cpylen;

	if (from > mtd->size)
		return -EINVAL;
	if (from + len > mtd->size)
		len = mtd->size - from;

	if (retlen)
		*retlen = 0;

	while (len) {
		if ((offset + len) > PAGE_SIZE)
			cpylen = PAGE_SIZE - offset;	// multiple pages
		else
			cpylen = len;	// this page
		len = len - cpylen;

		page = page_read(dev->blkdev->bd_inode->i_mapping, index);
		if (!page)
			return -ENOMEM;
		if (IS_ERR(page))
			return PTR_ERR(page);

		memcpy(buf, page_address(page) + offset, cpylen);
		page_cache_release(page);

		if (retlen)
			*retlen += cpylen;
		buf += cpylen;
		offset = 0;
		index++;
	}
	return 0;
}


/* write data to the underlying device */
static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
		loff_t to, size_t len, size_t *retlen)
{
	struct page *page;
	struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
	int index = to >> PAGE_SHIFT;	// page index
	int offset = to & ~PAGE_MASK;	// page offset
	int cpylen;

	if (retlen)
		*retlen = 0;
	while (len) {
		if ((offset+len) > PAGE_SIZE)
			cpylen = PAGE_SIZE - offset;	// multiple pages
		else
			cpylen = len;			// this page
		len = len - cpylen;

		page = page_read(mapping, index);
		if (!page)
			return -ENOMEM;
		if (IS_ERR(page))
			return PTR_ERR(page);

		if (memcmp(page_address(page)+offset, buf, cpylen)) {
			lock_page(page);
			memcpy(page_address(page) + offset, buf, cpylen);
			set_page_dirty(page);
			unlock_page(page);
		}
		page_cache_release(page);

		if (retlen)
			*retlen += cpylen;

		buf += cpylen;
		offset = 0;
		index++;
	}
	return 0;
}


static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
		size_t *retlen, const u_char *buf)
{
	struct block2mtd_dev *dev = mtd->priv;
	int err;

	if (!len)
		return 0;
	if (to >= mtd->size)
		return -ENOSPC;
	if (to + len > mtd->size)
		len = mtd->size - to;

	mutex_lock(&dev->write_mutex);
	err = _block2mtd_write(dev, buf, to, len, retlen);
	mutex_unlock(&dev->write_mutex);
	if (err > 0)
		err = 0;
	return err;
}


/* sync the device - wait until the write queue is empty */
static void block2mtd_sync(struct mtd_info *mtd)
{
	struct block2mtd_dev *dev = mtd->priv;
	sync_blockdev(dev->blkdev);
	return;
}


static void block2mtd_free_device(struct block2mtd_dev *dev)
{
	if (!dev)
		return;

	kfree(dev->mtd.name);

	if (dev->blkdev) {
		invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
					0, -1);
		blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
	}

	kfree(dev);
}


/* FIXME: ensure that mtd->size % erase_size == 0 */
static struct block2mtd_dev *add_device(char *devname, int erase_size)
{
	const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
	struct block_device *bdev;
	struct block2mtd_dev *dev;
	char *name;

	if (!devname)
		return NULL;

	dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
	if (!dev)
		return NULL;

	/* Get a handle on the device */
	bdev = blkdev_get_by_path(devname, mode, dev);
#ifndef MODULE
	if (IS_ERR(bdev)) {

		/* We might not have rootfs mounted at this point. Try
		   to resolve the device name by other means. */

		dev_t devt = name_to_dev_t(devname);
		if (devt)
			bdev = blkdev_get_by_dev(devt, mode, dev);
	}
#endif

	if (IS_ERR(bdev)) {
		ERROR("error: cannot open device %s", devname);
		goto devinit_err;
	}
	dev->blkdev = bdev;

	if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
		ERROR("attempting to use an MTD device as a block device");
		goto devinit_err;
	}

	mutex_init(&dev->write_mutex);

	/* Setup the MTD structure */
	/* make the name contain the block device in */
	name = kasprintf(GFP_KERNEL, "block2mtd: %s", devname);
	if (!name)
		goto devinit_err;

	dev->mtd.name = name;

	dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
	dev->mtd.erasesize = erase_size;
	dev->mtd.writesize = 1;
	dev->mtd.type = MTD_RAM;
	dev->mtd.flags = MTD_CAP_RAM;
	dev->mtd._erase = block2mtd_erase;
	dev->mtd._write = block2mtd_write;
	dev->mtd._writev = mtd_writev;
	dev->mtd._sync = block2mtd_sync;
	dev->mtd._read = block2mtd_read;
	dev->mtd.priv = dev;
	dev->mtd.owner = THIS_MODULE;

	if (mtd_device_register(&dev->mtd, NULL, 0)) {
		/* Device didn't get added, so free the entry */
		goto devinit_err;
	}
	list_add(&dev->list, &blkmtd_device_list);
	INFO("mtd%d: [%s] erase_size = %dKiB [%d]", dev->mtd.index,
			dev->mtd.name + strlen("block2mtd: "),
			dev->mtd.erasesize >> 10, dev->mtd.erasesize);
	return dev;

devinit_err:
	block2mtd_free_device(dev);
	return NULL;
}


/* This function works similar to reguler strtoul.  In addition, it
 * allows some suffixes for a more human-readable number format:
 * ki, Ki, kiB, KiB	- multiply result with 1024
 * Mi, MiB		- multiply result with 1024^2
 * Gi, GiB		- multiply result with 1024^3
 */
static int ustrtoul(const char *cp, char **endp, unsigned int base)
{
	unsigned long result = simple_strtoul(cp, endp, base);
	switch (**endp) {
	case 'G' :
		result *= 1024;
	case 'M':
		result *= 1024;
	case 'K':
	case 'k':
		result *= 1024;
	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
		if ((*endp)[1] == 'i') {
			if ((*endp)[2] == 'B')
				(*endp) += 3;
			else
				(*endp) += 2;
		}
	}
	return result;
}


static int parse_num(size_t *num, const char *token)
{
	char *endp;
	size_t n;

	n = (size_t) ustrtoul(token, &endp, 0);
	if (*endp)
		return -EINVAL;

	*num = n;
	return 0;
}


static inline void kill_final_newline(char *str)
{
	char *newline = strrchr(str, '\n');
	if (newline && !newline[1])
		*newline = 0;
}


#define parse_err(fmt, args...) do {	\
	ERROR(fmt, ## args);		\
	return 0;			\
} while (0)

#ifndef MODULE
static int block2mtd_init_called = 0;
static char block2mtd_paramline[80 + 12]; /* 80 for device, 12 for erase size */
#endif


static int block2mtd_setup2(const char *val)
{
	char buf[80 + 12]; /* 80 for device, 12 for erase size */
	char *str = buf;
	char *token[2];
	char *name;
	size_t erase_size = PAGE_SIZE;
	int i, ret;

	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
		parse_err("parameter too long");

	strcpy(str, val);
	kill_final_newline(str);

	for (i = 0; i < 2; i++)
		token[i] = strsep(&str, ",");

	if (str)
		parse_err("too many arguments");

	if (!token[0])
		parse_err("no argument");

	name = token[0];
	if (strlen(name) + 1 > 80)
		parse_err("device name too long");

	if (token[1]) {
		ret = parse_num(&erase_size, token[1]);
		if (ret) {
			parse_err("illegal erase size");
		}
	}

	add_device(name, erase_size);

	return 0;
}


static int block2mtd_setup(const char *val, struct kernel_param *kp)
{
#ifdef MODULE
	return block2mtd_setup2(val);
#else
	/* If more parameters are later passed in via
	   /sys/module/block2mtd/parameters/block2mtd
	   and block2mtd_init() has already been called,
	   we can parse the argument now. */

	if (block2mtd_init_called)
		return block2mtd_setup2(val);

	/* During early boot stage, we only save the parameters
	   here. We must parse them later: if the param passed
	   from kernel boot command line, block2mtd_setup() is
	   called so early that it is not possible to resolve
	   the device (even kmalloc() fails). Deter that work to
	   block2mtd_setup2(). */

	strlcpy(block2mtd_paramline, val, sizeof(block2mtd_paramline));

	return 0;
#endif
}


module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>]\"");

static int __init block2mtd_init(void)
{
	int ret = 0;

#ifndef MODULE
	if (strlen(block2mtd_paramline))
		ret = block2mtd_setup2(block2mtd_paramline);
	block2mtd_init_called = 1;
#endif

	return ret;
}


static void __devexit block2mtd_exit(void)
{
	struct list_head *pos, *next;

	/* Remove the MTD devices */
	list_for_each_safe(pos, next, &blkmtd_device_list) {
		struct block2mtd_dev *dev = list_entry(pos, typeof(*dev), list);
		block2mtd_sync(&dev->mtd);
		mtd_device_unregister(&dev->mtd);
		INFO("mtd%d: [%s] removed", dev->mtd.index,
				dev->mtd.name + strlen("block2mtd: "));
		list_del(&dev->list);
		block2mtd_free_device(dev);
	}
}


module_init(block2mtd_init);
module_exit(block2mtd_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joern Engel <joern@lazybastard.org>");
MODULE_DESCRIPTION("Emulate an MTD using a block device");
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	2	* block2mtd.c - create an mtd from a block device
	3	*
	4	* Copyright (C) 2001,2002 Simon Evans <spse@secret.org.uk>
2b54aaef	5	* Copyright (C) 2004-2006 Joern Engel <joern@wh.fh-wedel.de>
1da177e4 LT	6	*
	7	* Licence: GPL
	8	*/
1da177e4 LT	9	#include <linux/module.h>
	10	#include <linux/fs.h>
	11	#include <linux/blkdev.h>
	12	#include <linux/bio.h>
	13	#include <linux/pagemap.h>
	14	#include <linux/list.h>
	15	#include <linux/init.h>
	16	#include <linux/mtd/mtd.h>
48b19268	17	#include <linux/mutex.h>
c4e7fb31	18	#include <linux/mount.h>
5a0e3ad6	19	#include <linux/slab.h>
1da177e4	20
1da177e4 LT	21	#define ERROR(fmt, args...) printk(KERN_ERR "block2mtd: " fmt "\n" , ## args)
	22	#define INFO(fmt, args...) printk(KERN_INFO "block2mtd: " fmt "\n" , ## args)
	23
	24
	25	/* Info for the block device */
	26	struct block2mtd_dev {
	27	struct list_head list;
	28	struct block_device *blkdev;
	29	struct mtd_info mtd;
48b19268	30	struct mutex write_mutex;
1da177e4 LT	31	};
	32
	33
	34	/* Static info about the MTD, used in cleanup_module */
	35	static LIST_HEAD(blkmtd_device_list);
	36
	37
6fe6900e	38	static struct page page_read(struct address_space mapping, int index)
1da177e4	39	{
6fe6900e	40	return read_mapping_page(mapping, index, NULL);
1da177e4 LT	41	}
1da177e4 LT	42
1da177e4 LT	43	/* erase a specified part of the device */
	44	static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
	45	{
	46	struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
	47	struct page *page;
	48	int index = to >> PAGE_SHIFT; // page index
	49	int pages = len >> PAGE_SHIFT;
	50	u_long *p;
	51	u_long *max;
	52
	53	while (pages) {
21d31f1f	54	page = page_read(mapping, index);
1da177e4 LT	55	if (!page)
	56	return -ENOMEM;
	57	if (IS_ERR(page))
	58	return PTR_ERR(page);
	59
0ffb74cc JE	60	max = page_address(page) + PAGE_SIZE;
0ffb74cc JE	61	for (p=page_address(page); p<max; p++)
1da177e4 LT	62	if (*p != -1UL) {
	63	lock_page(page);
	64	memset(page_address(page), 0xff, PAGE_SIZE);
	65	set_page_dirty(page);
	66	unlock_page(page);
	67	break;
	68	}
	69
	70	page_cache_release(page);
	71	pages--;
	72	index++;
	73	}
	74	return 0;
	75	}
	76	static int block2mtd_erase(struct mtd_info mtd, struct erase_info instr)
	77	{
	78	struct block2mtd_dev *dev = mtd->priv;
	79	size_t from = instr->addr;
	80	size_t len = instr->len;
	81	int err;
	82
	83	instr->state = MTD_ERASING;
48b19268	84	mutex_lock(&dev->write_mutex);
1da177e4	85	err = _block2mtd_erase(dev, from, len);
48b19268	86	mutex_unlock(&dev->write_mutex);
1da177e4 LT	87	if (err) {
	88	ERROR("erase failed err = %d", err);
	89	instr->state = MTD_ERASE_FAILED;
	90	} else
	91	instr->state = MTD_ERASE_DONE;
	92
1da177e4 LT	93	mtd_erase_callback(instr);
	94	return err;
	95	}
	96
	97
	98	static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
	99	size_t retlen, u_char buf)
	100	{
	101	struct block2mtd_dev *dev = mtd->priv;
	102	struct page *page;
	103	int index = from >> PAGE_SHIFT;
711c11b7	104	int offset = from & (PAGE_SIZE-1);
1da177e4 LT	105	int cpylen;
	106
	107	if (from > mtd->size)
	108	return -EINVAL;
	109	if (from + len > mtd->size)
	110	len = mtd->size - from;
	111
	112	if (retlen)
	113	*retlen = 0;
	114
	115	while (len) {
	116	if ((offset + len) > PAGE_SIZE)
	117	cpylen = PAGE_SIZE - offset; // multiple pages
	118	else
	119	cpylen = len; // this page
	120	len = len - cpylen;
	121
21d31f1f	122	page = page_read(dev->blkdev->bd_inode->i_mapping, index);
1da177e4 LT	123	if (!page)
	124	return -ENOMEM;
	125	if (IS_ERR(page))
	126	return PTR_ERR(page);
	127
	128	memcpy(buf, page_address(page) + offset, cpylen);
	129	page_cache_release(page);
	130
	131	if (retlen)
	132	*retlen += cpylen;
	133	buf += cpylen;
	134	offset = 0;
	135	index++;
	136	}
	137	return 0;
	138	}
	139
	140
	141	/* write data to the underlying device */
	142	static int _block2mtd_write(struct block2mtd_dev dev, const u_char buf,
	143	loff_t to, size_t len, size_t *retlen)
	144	{
	145	struct page *page;
	146	struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
	147	int index = to >> PAGE_SHIFT; // page index
	148	int offset = to & ~PAGE_MASK; // page offset
	149	int cpylen;
	150
	151	if (retlen)
	152	*retlen = 0;
	153	while (len) {
e5580fbe	154	if ((offset+len) > PAGE_SIZE)
1da177e4 LT	155	cpylen = PAGE_SIZE - offset; // multiple pages
	156	else
	157	cpylen = len; // this page
	158	len = len - cpylen;
	159
21d31f1f	160	page = page_read(mapping, index);
1da177e4 LT	161	if (!page)
	162	return -ENOMEM;
	163	if (IS_ERR(page))
	164	return PTR_ERR(page);
	165
	166	if (memcmp(page_address(page)+offset, buf, cpylen)) {
	167	lock_page(page);
	168	memcpy(page_address(page) + offset, buf, cpylen);
	169	set_page_dirty(page);
	170	unlock_page(page);
	171	}
	172	page_cache_release(page);
	173
	174	if (retlen)
	175	*retlen += cpylen;
	176
	177	buf += cpylen;
	178	offset = 0;
	179	index++;
	180	}
	181	return 0;
	182	}
c4e7fb31 VH	183
c4e7fb31 VH	184
1da177e4 LT	185	static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
	186	size_t retlen, const u_char buf)
	187	{
	188	struct block2mtd_dev *dev = mtd->priv;
	189	int err;
	190
	191	if (!len)
	192	return 0;
	193	if (to >= mtd->size)
	194	return -ENOSPC;
	195	if (to + len > mtd->size)
	196	len = mtd->size - to;
	197
48b19268	198	mutex_lock(&dev->write_mutex);
1da177e4	199	err = _block2mtd_write(dev, buf, to, len, retlen);
48b19268	200	mutex_unlock(&dev->write_mutex);
1da177e4 LT	201	if (err > 0)
	202	err = 0;
	203	return err;
	204	}
	205
	206
	207	/* sync the device - wait until the write queue is empty */
	208	static void block2mtd_sync(struct mtd_info *mtd)
	209	{
	210	struct block2mtd_dev *dev = mtd->priv;
	211	sync_blockdev(dev->blkdev);
	212	return;
	213	}
	214
	215
	216	static void block2mtd_free_device(struct block2mtd_dev *dev)
	217	{
	218	if (!dev)
	219	return;
	220
	221	kfree(dev->mtd.name);
	222
	223	if (dev->blkdev) {
fc0ecff6 AM	224	invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
fc0ecff6 AM	225	0, -1);
e525fd89	226	blkdev_put(dev->blkdev, FMODE_READ\|FMODE_WRITE\|FMODE_EXCL);
1da177e4 LT	227	}
	228
	229	kfree(dev);
	230	}
	231
	232
	233	/* FIXME: ensure that mtd->size % erase_size == 0 */
	234	static struct block2mtd_dev add_device(char devname, int erase_size)
	235	{
e525fd89	236	const fmode_t mode = FMODE_READ \| FMODE_WRITE \| FMODE_EXCL;
1da177e4 LT	237	struct block_device *bdev;
1da177e4 LT	238	struct block2mtd_dev *dev;
eadcf0d7	239	char *name;
1da177e4 LT	240
	241	if (!devname)
	242	return NULL;
	243
95b93a0c	244	dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
1da177e4 LT	245	if (!dev)
1da177e4 LT	246	return NULL;
1da177e4 LT	247
1da177e4 LT	248	/* Get a handle on the device */
d4d77629	249	bdev = blkdev_get_by_path(devname, mode, dev);
c4e7fb31 VH	250	#ifndef MODULE
	251	if (IS_ERR(bdev)) {
	252
	253	/* We might not have rootfs mounted at this point. Try
	254	to resolve the device name by other means. */
	255
8870530a	256	dev_t devt = name_to_dev_t(devname);
e525fd89	257	if (devt)
d4d77629	258	bdev = blkdev_get_by_dev(devt, mode, dev);
c4e7fb31 VH	259	}
	260	#endif
	261
1da177e4 LT	262	if (IS_ERR(bdev)) {
	263	ERROR("error: cannot open device %s", devname);
	264	goto devinit_err;
	265	}
	266	dev->blkdev = bdev;
	267
	268	if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
	269	ERROR("attempting to use an MTD device as a block device");
	270	goto devinit_err;
	271	}
	272
48b19268	273	mutex_init(&dev->write_mutex);
1da177e4 LT	274
	275	/* Setup the MTD structure */
	276	/* make the name contain the block device in */
4d682420	277	name = kasprintf(GFP_KERNEL, "block2mtd: %s", devname);
eadcf0d7	278	if (!name)
1da177e4 LT	279	goto devinit_err;
1da177e4 LT	280
eadcf0d7	281	dev->mtd.name = name;
1da177e4 LT	282
	283	dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
	284	dev->mtd.erasesize = erase_size;
17ffc7ba	285	dev->mtd.writesize = 1;
21c8db9e	286	dev->mtd.type = MTD_RAM;
1da177e4	287	dev->mtd.flags = MTD_CAP_RAM;
3c3c10bb AB	288	dev->mtd._erase = block2mtd_erase;
	289	dev->mtd._write = block2mtd_write;
	290	dev->mtd._writev = mtd_writev;
	291	dev->mtd._sync = block2mtd_sync;
	292	dev->mtd._read = block2mtd_read;
1da177e4 LT	293	dev->mtd.priv = dev;
	294	dev->mtd.owner = THIS_MODULE;
	295
ee0e87b1	296	if (mtd_device_register(&dev->mtd, NULL, 0)) {
25985edc	297	/* Device didn't get added, so free the entry */
1da177e4 LT	298	goto devinit_err;
	299	}
	300	list_add(&dev->list, &blkmtd_device_list);
	301	INFO("mtd%d: [%s] erase_size = %dKiB [%d]", dev->mtd.index,
0bc88c59	302	dev->mtd.name + strlen("block2mtd: "),
1da177e4 LT	303	dev->mtd.erasesize >> 10, dev->mtd.erasesize);
	304	return dev;
	305
	306	devinit_err:
	307	block2mtd_free_device(dev);
	308	return NULL;
	309	}
	310
	311
954c2422 JE	312	/* This function works similar to reguler strtoul. In addition, it
	313	* allows some suffixes for a more human-readable number format:
	314	* ki, Ki, kiB, KiB - multiply result with 1024
	315	* Mi, MiB - multiply result with 1024^2
	316	* Gi, GiB - multiply result with 1024^3
	317	*/
1da177e4 LT	318	static int ustrtoul(const char cp, char *endp, unsigned int base)
	319	{
	320	unsigned long result = simple_strtoul(cp, endp, base);
	321	switch (**endp) {
	322	case 'G' :
	323	result *= 1024;
	324	case 'M':
	325	result *= 1024;
954c2422	326	case 'K':
1da177e4 LT	327	case 'k':
	328	result *= 1024;
	329	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
954c2422 JE	330	if ((*endp)[1] == 'i') {
	331	if ((*endp)[2] == 'B')
	332	(*endp) += 3;
	333	else
	334	(*endp) += 2;
	335	}
1da177e4 LT	336	}
	337	return result;
	338	}
	339
	340
cc71229f	341	static int parse_num(size_t num, const char token)
1da177e4 LT	342	{
1da177e4 LT	343	char *endp;
cc71229f	344	size_t n;
1da177e4	345
cc71229f	346	n = (size_t) ustrtoul(token, &endp, 0);
1da177e4 LT	347	if (*endp)
	348	return -EINVAL;
	349
cc71229f	350	*num = n;
1da177e4 LT	351	return 0;
	352	}
	353
	354
1da177e4 LT	355	static inline void kill_final_newline(char *str)
	356	{
	357	char *newline = strrchr(str, '\n');
	358	if (newline && !newline[1])
	359	*newline = 0;
	360	}
	361
	362
0bc88c59 SC	363	#define parse_err(fmt, args...) do { \
	364	ERROR(fmt, ## args); \
	365	return 0; \
1da177e4 LT	366	} while (0)
1da177e4 LT	367
c4e7fb31 VH	368	#ifndef MODULE
c4e7fb31 VH	369	static int block2mtd_init_called = 0;
4839f048	370	static char block2mtd_paramline[80 + 12]; /* 80 for device, 12 for erase size */
c4e7fb31 VH	371	#endif
	372
	373
	374	static int block2mtd_setup2(const char *val)
1da177e4	375	{
c4e7fb31	376	char buf[80 + 12]; /* 80 for device, 12 for erase size */
a6550e57	377	char *str = buf;
1da177e4 LT	378	char *token[2];
1da177e4 LT	379	char *name;
cc71229f	380	size_t erase_size = PAGE_SIZE;
1da177e4 LT	381	int i, ret;
	382
	383	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
	384	parse_err("parameter too long");
	385
	386	strcpy(str, val);
	387	kill_final_newline(str);
	388
a6550e57	389	for (i = 0; i < 2; i++)
1da177e4 LT	390	token[i] = strsep(&str, ",");
	391
	392	if (str)
	393	parse_err("too many arguments");
	394
	395	if (!token[0])
	396	parse_err("no argument");
	397
c4e7fb31 VH	398	name = token[0];
	399	if (strlen(name) + 1 > 80)
	400	parse_err("device name too long");
1da177e4 LT	401
1da177e4 LT	402	if (token[1]) {
cc71229f	403	ret = parse_num(&erase_size, token[1]);
a6550e57	404	if (ret) {
1da177e4	405	parse_err("illegal erase size");
a6550e57	406	}
1da177e4 LT	407	}
	408
	409	add_device(name, erase_size);
	410
	411	return 0;
	412	}
	413
	414
c4e7fb31 VH	415	static int block2mtd_setup(const char val, struct kernel_param kp)
	416	{
	417	#ifdef MODULE
	418	return block2mtd_setup2(val);
	419	#else
	420	/* If more parameters are later passed in via
	421	/sys/module/block2mtd/parameters/block2mtd
	422	and block2mtd_init() has already been called,
	423	we can parse the argument now. */
	424
	425	if (block2mtd_init_called)
	426	return block2mtd_setup2(val);
	427
	428	/* During early boot stage, we only save the parameters
	429	here. We must parse them later: if the param passed
	430	from kernel boot command line, block2mtd_setup() is
	431	called so early that it is not possible to resolve
	432	the device (even kmalloc() fails). Deter that work to
	433	block2mtd_setup2(). */
	434
	435	strlcpy(block2mtd_paramline, val, sizeof(block2mtd_paramline));
	436
	437	return 0;
	438	#endif
	439	}
	440
	441
1da177e4 LT	442	module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
	443	MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>]\"");
	444
	445	static int __init block2mtd_init(void)
	446	{
c4e7fb31	447	int ret = 0;
c4e7fb31 VH	448
	449	#ifndef MODULE
	450	if (strlen(block2mtd_paramline))
	451	ret = block2mtd_setup2(block2mtd_paramline);
	452	block2mtd_init_called = 1;
	453	#endif
	454
	455	return ret;
1da177e4 LT	456	}
	457
	458
	459	static void __devexit block2mtd_exit(void)
	460	{
	461	struct list_head pos, next;
	462
	463	/* Remove the MTD devices */
	464	list_for_each_safe(pos, next, &blkmtd_device_list) {
	465	struct block2mtd_dev dev = list_entry(pos, typeof(dev), list);
	466	block2mtd_sync(&dev->mtd);
ee0e87b1	467	mtd_device_unregister(&dev->mtd);
1da177e4	468	INFO("mtd%d: [%s] removed", dev->mtd.index,
0bc88c59	469	dev->mtd.name + strlen("block2mtd: "));
1da177e4 LT	470	list_del(&dev->list);
	471	block2mtd_free_device(dev);
	472	}
	473	}
	474
	475
	476	module_init(block2mtd_init);
	477	module_exit(block2mtd_exit);
	478
	479	MODULE_LICENSE("GPL");
2b54aaef	480	MODULE_AUTHOR("Joern Engel <joern@lazybastard.org>");
1da177e4	481	MODULE_DESCRIPTION("Emulate an MTD using a block device");