[mirror_ubuntu-artful-kernel.git] / drivers / mtd / devices / block2mtd.c

/*
 * $Id: block2mtd.c,v 1.30 2005/11/29 14:48:32 gleixner Exp $
 *
 * 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/buffer_head.h>
#include <linux/mutex.h>
#include <linux/mount.h>

#define VERSION "$Revision: 1.30 $"


#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;

	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);
		close_bdev_excl(dev->blkdev);
	}

	kfree(dev);
}


/* FIXME: ensure that mtd->size % erase_size == 0 */
static struct block2mtd_dev *add_device(char *devname, int erase_size)
{
	struct block_device *bdev;
	struct block2mtd_dev *dev;

	if (!devname)
		return NULL;

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

	/* Get a handle on the device */
	bdev = open_bdev_excl(devname, O_RDWR, NULL);
#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 = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
		}
	}
#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 */
	dev->mtd.name = kmalloc(sizeof("block2mtd: ") + strlen(devname),
			GFP_KERNEL);
	if (!dev->mtd.name)
		goto devinit_err;

	sprintf(dev->mtd.name, "block2mtd: %s", devname);

	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 = default_mtd_writev;
	dev->mtd.sync = block2mtd_sync;
	dev->mtd.read = block2mtd_read;
	dev->mtd.priv = dev;
	dev->mtd.owner = THIS_MODULE;

	if (add_mtd_device(&dev->mtd)) {
		/* Device didnt 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;
	INFO("version " VERSION);

#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);
		del_mtd_device(&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	/*
2b9175c1	2	* $Id: block2mtd.c,v 1.30 2005/11/29 14:48:32 gleixner Exp $
1da177e4 LT	3	*
	4	* block2mtd.c - create an mtd from a block device
	5	*
	6	* Copyright (C) 2001,2002 Simon Evans <spse@secret.org.uk>
2b54aaef	7	* Copyright (C) 2004-2006 Joern Engel <joern@wh.fh-wedel.de>
1da177e4 LT	8	*
	9	* Licence: GPL
	10	*/
1da177e4 LT	11	#include <linux/module.h>
	12	#include <linux/fs.h>
	13	#include <linux/blkdev.h>
	14	#include <linux/bio.h>
	15	#include <linux/pagemap.h>
	16	#include <linux/list.h>
	17	#include <linux/init.h>
	18	#include <linux/mtd/mtd.h>
	19	#include <linux/buffer_head.h>
48b19268	20	#include <linux/mutex.h>
c4e7fb31	21	#include <linux/mount.h>
1da177e4	22
2b9175c1	23	#define VERSION "$Revision: 1.30 $"
1da177e4 LT	24
	25
	26	#define ERROR(fmt, args...) printk(KERN_ERR "block2mtd: " fmt "\n" , ## args)
	27	#define INFO(fmt, args...) printk(KERN_INFO "block2mtd: " fmt "\n" , ## args)
	28
	29
	30	/* Info for the block device */
	31	struct block2mtd_dev {
	32	struct list_head list;
	33	struct block_device *blkdev;
	34	struct mtd_info mtd;
48b19268	35	struct mutex write_mutex;
1da177e4 LT	36	};
	37
	38
	39	/* Static info about the MTD, used in cleanup_module */
	40	static LIST_HEAD(blkmtd_device_list);
	41
	42
6fe6900e	43	static struct page page_read(struct address_space mapping, int index)
1da177e4	44	{
6fe6900e	45	return read_mapping_page(mapping, index, NULL);
1da177e4 LT	46	}
1da177e4 LT	47
1da177e4 LT	48	/* erase a specified part of the device */
	49	static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
	50	{
	51	struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
	52	struct page *page;
	53	int index = to >> PAGE_SHIFT; // page index
	54	int pages = len >> PAGE_SHIFT;
	55	u_long *p;
	56	u_long *max;
	57
	58	while (pages) {
21d31f1f	59	page = page_read(mapping, index);
1da177e4 LT	60	if (!page)
	61	return -ENOMEM;
	62	if (IS_ERR(page))
	63	return PTR_ERR(page);
	64
0ffb74cc JE	65	max = page_address(page) + PAGE_SIZE;
0ffb74cc JE	66	for (p=page_address(page); p<max; p++)
1da177e4 LT	67	if (*p != -1UL) {
	68	lock_page(page);
	69	memset(page_address(page), 0xff, PAGE_SIZE);
	70	set_page_dirty(page);
	71	unlock_page(page);
	72	break;
	73	}
	74
	75	page_cache_release(page);
	76	pages--;
	77	index++;
	78	}
	79	return 0;
	80	}
	81	static int block2mtd_erase(struct mtd_info mtd, struct erase_info instr)
	82	{
	83	struct block2mtd_dev *dev = mtd->priv;
	84	size_t from = instr->addr;
	85	size_t len = instr->len;
	86	int err;
	87
	88	instr->state = MTD_ERASING;
48b19268	89	mutex_lock(&dev->write_mutex);
1da177e4	90	err = _block2mtd_erase(dev, from, len);
48b19268	91	mutex_unlock(&dev->write_mutex);
1da177e4 LT	92	if (err) {
	93	ERROR("erase failed err = %d", err);
	94	instr->state = MTD_ERASE_FAILED;
	95	} else
	96	instr->state = MTD_ERASE_DONE;
	97
	98	instr->state = MTD_ERASE_DONE;
	99	mtd_erase_callback(instr);
	100	return err;
	101	}
	102
	103
	104	static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
	105	size_t retlen, u_char buf)
	106	{
	107	struct block2mtd_dev *dev = mtd->priv;
	108	struct page *page;
	109	int index = from >> PAGE_SHIFT;
711c11b7	110	int offset = from & (PAGE_SIZE-1);
1da177e4 LT	111	int cpylen;
	112
	113	if (from > mtd->size)
	114	return -EINVAL;
	115	if (from + len > mtd->size)
	116	len = mtd->size - from;
	117
	118	if (retlen)
	119	*retlen = 0;
	120
	121	while (len) {
	122	if ((offset + len) > PAGE_SIZE)
	123	cpylen = PAGE_SIZE - offset; // multiple pages
	124	else
	125	cpylen = len; // this page
	126	len = len - cpylen;
	127
21d31f1f	128	page = page_read(dev->blkdev->bd_inode->i_mapping, index);
1da177e4 LT	129	if (!page)
	130	return -ENOMEM;
	131	if (IS_ERR(page))
	132	return PTR_ERR(page);
	133
	134	memcpy(buf, page_address(page) + offset, cpylen);
	135	page_cache_release(page);
	136
	137	if (retlen)
	138	*retlen += cpylen;
	139	buf += cpylen;
	140	offset = 0;
	141	index++;
	142	}
	143	return 0;
	144	}
	145
	146
	147	/* write data to the underlying device */
	148	static int _block2mtd_write(struct block2mtd_dev dev, const u_char buf,
	149	loff_t to, size_t len, size_t *retlen)
	150	{
	151	struct page *page;
	152	struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
	153	int index = to >> PAGE_SHIFT; // page index
	154	int offset = to & ~PAGE_MASK; // page offset
	155	int cpylen;
	156
	157	if (retlen)
	158	*retlen = 0;
	159	while (len) {
e5580fbe	160	if ((offset+len) > PAGE_SIZE)
1da177e4 LT	161	cpylen = PAGE_SIZE - offset; // multiple pages
	162	else
	163	cpylen = len; // this page
	164	len = len - cpylen;
	165
21d31f1f	166	page = page_read(mapping, index);
1da177e4 LT	167	if (!page)
	168	return -ENOMEM;
	169	if (IS_ERR(page))
	170	return PTR_ERR(page);
	171
	172	if (memcmp(page_address(page)+offset, buf, cpylen)) {
	173	lock_page(page);
	174	memcpy(page_address(page) + offset, buf, cpylen);
	175	set_page_dirty(page);
	176	unlock_page(page);
	177	}
	178	page_cache_release(page);
	179
	180	if (retlen)
	181	*retlen += cpylen;
	182
	183	buf += cpylen;
	184	offset = 0;
	185	index++;
	186	}
	187	return 0;
	188	}
c4e7fb31 VH	189
c4e7fb31 VH	190
1da177e4 LT	191	static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
	192	size_t retlen, const u_char buf)
	193	{
	194	struct block2mtd_dev *dev = mtd->priv;
	195	int err;
	196
	197	if (!len)
	198	return 0;
	199	if (to >= mtd->size)
	200	return -ENOSPC;
	201	if (to + len > mtd->size)
	202	len = mtd->size - to;
	203
48b19268	204	mutex_lock(&dev->write_mutex);
1da177e4	205	err = _block2mtd_write(dev, buf, to, len, retlen);
48b19268	206	mutex_unlock(&dev->write_mutex);
1da177e4 LT	207	if (err > 0)
	208	err = 0;
	209	return err;
	210	}
	211
	212
	213	/* sync the device - wait until the write queue is empty */
	214	static void block2mtd_sync(struct mtd_info *mtd)
	215	{
	216	struct block2mtd_dev *dev = mtd->priv;
	217	sync_blockdev(dev->blkdev);
	218	return;
	219	}
	220
	221
	222	static void block2mtd_free_device(struct block2mtd_dev *dev)
	223	{
	224	if (!dev)
	225	return;
	226
	227	kfree(dev->mtd.name);
	228
	229	if (dev->blkdev) {
fc0ecff6 AM	230	invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
fc0ecff6 AM	231	0, -1);
1da177e4 LT	232	close_bdev_excl(dev->blkdev);
	233	}
	234
	235	kfree(dev);
	236	}
	237
	238
	239	/* FIXME: ensure that mtd->size % erase_size == 0 */
	240	static struct block2mtd_dev add_device(char devname, int erase_size)
	241	{
	242	struct block_device *bdev;
	243	struct block2mtd_dev *dev;
	244
	245	if (!devname)
	246	return NULL;
	247
95b93a0c	248	dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
1da177e4 LT	249	if (!dev)
1da177e4 LT	250	return NULL;
1da177e4 LT	251
	252	/* Get a handle on the device */
	253	bdev = open_bdev_excl(devname, O_RDWR, NULL);
c4e7fb31 VH	254	#ifndef MODULE
	255	if (IS_ERR(bdev)) {
	256
	257	/* We might not have rootfs mounted at this point. Try
	258	to resolve the device name by other means. */
	259
8870530a JE	260	dev_t devt = name_to_dev_t(devname);
	261	if (devt) {
	262	bdev = open_by_devnum(devt, FMODE_WRITE \| FMODE_READ);
c4e7fb31 VH	263	}
	264	}
	265	#endif
	266
1da177e4 LT	267	if (IS_ERR(bdev)) {
	268	ERROR("error: cannot open device %s", devname);
	269	goto devinit_err;
	270	}
	271	dev->blkdev = bdev;
	272
	273	if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
	274	ERROR("attempting to use an MTD device as a block device");
	275	goto devinit_err;
	276	}
	277
48b19268	278	mutex_init(&dev->write_mutex);
1da177e4 LT	279
	280	/* Setup the MTD structure */
	281	/* make the name contain the block device in */
	282	dev->mtd.name = kmalloc(sizeof("block2mtd: ") + strlen(devname),
	283	GFP_KERNEL);
	284	if (!dev->mtd.name)
	285	goto devinit_err;
	286
	287	sprintf(dev->mtd.name, "block2mtd: %s", devname);
	288
	289	dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
	290	dev->mtd.erasesize = erase_size;
17ffc7ba	291	dev->mtd.writesize = 1;
21c8db9e	292	dev->mtd.type = MTD_RAM;
1da177e4 LT	293	dev->mtd.flags = MTD_CAP_RAM;
	294	dev->mtd.erase = block2mtd_erase;
	295	dev->mtd.write = block2mtd_write;
	296	dev->mtd.writev = default_mtd_writev;
	297	dev->mtd.sync = block2mtd_sync;
	298	dev->mtd.read = block2mtd_read;
1da177e4 LT	299	dev->mtd.priv = dev;
	300	dev->mtd.owner = THIS_MODULE;
	301
	302	if (add_mtd_device(&dev->mtd)) {
	303	/* Device didnt get added, so free the entry */
	304	goto devinit_err;
	305	}
	306	list_add(&dev->list, &blkmtd_device_list);
	307	INFO("mtd%d: [%s] erase_size = %dKiB [%d]", dev->mtd.index,
0bc88c59	308	dev->mtd.name + strlen("block2mtd: "),
1da177e4 LT	309	dev->mtd.erasesize >> 10, dev->mtd.erasesize);
	310	return dev;
	311
	312	devinit_err:
	313	block2mtd_free_device(dev);
	314	return NULL;
	315	}
	316
	317
954c2422 JE	318	/* This function works similar to reguler strtoul. In addition, it
	319	* allows some suffixes for a more human-readable number format:
	320	* ki, Ki, kiB, KiB - multiply result with 1024
	321	* Mi, MiB - multiply result with 1024^2
	322	* Gi, GiB - multiply result with 1024^3
	323	*/
1da177e4 LT	324	static int ustrtoul(const char cp, char *endp, unsigned int base)
	325	{
	326	unsigned long result = simple_strtoul(cp, endp, base);
	327	switch (**endp) {
	328	case 'G' :
	329	result *= 1024;
	330	case 'M':
	331	result *= 1024;
954c2422	332	case 'K':
1da177e4 LT	333	case 'k':
	334	result *= 1024;
	335	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
954c2422 JE	336	if ((*endp)[1] == 'i') {
	337	if ((*endp)[2] == 'B')
	338	(*endp) += 3;
	339	else
	340	(*endp) += 2;
	341	}
1da177e4 LT	342	}
	343	return result;
	344	}
	345
	346
cc71229f	347	static int parse_num(size_t num, const char token)
1da177e4 LT	348	{
1da177e4 LT	349	char *endp;
cc71229f	350	size_t n;
1da177e4	351
cc71229f	352	n = (size_t) ustrtoul(token, &endp, 0);
1da177e4 LT	353	if (*endp)
	354	return -EINVAL;
	355
cc71229f	356	*num = n;
1da177e4 LT	357	return 0;
	358	}
	359
	360
1da177e4 LT	361	static inline void kill_final_newline(char *str)
	362	{
	363	char *newline = strrchr(str, '\n');
	364	if (newline && !newline[1])
	365	*newline = 0;
	366	}
	367
	368
0bc88c59 SC	369	#define parse_err(fmt, args...) do { \
	370	ERROR(fmt, ## args); \
	371	return 0; \
1da177e4 LT	372	} while (0)
1da177e4 LT	373
c4e7fb31 VH	374	#ifndef MODULE
c4e7fb31 VH	375	static int block2mtd_init_called = 0;
4839f048	376	static char block2mtd_paramline[80 + 12]; /* 80 for device, 12 for erase size */
c4e7fb31 VH	377	#endif
	378
	379
	380	static int block2mtd_setup2(const char *val)
1da177e4	381	{
c4e7fb31	382	char buf[80 + 12]; /* 80 for device, 12 for erase size */
a6550e57	383	char *str = buf;
1da177e4 LT	384	char *token[2];
1da177e4 LT	385	char *name;
cc71229f	386	size_t erase_size = PAGE_SIZE;
1da177e4 LT	387	int i, ret;
	388
	389	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
	390	parse_err("parameter too long");
	391
	392	strcpy(str, val);
	393	kill_final_newline(str);
	394
a6550e57	395	for (i = 0; i < 2; i++)
1da177e4 LT	396	token[i] = strsep(&str, ",");
	397
	398	if (str)
	399	parse_err("too many arguments");
	400
	401	if (!token[0])
	402	parse_err("no argument");
	403
c4e7fb31 VH	404	name = token[0];
	405	if (strlen(name) + 1 > 80)
	406	parse_err("device name too long");
1da177e4 LT	407
1da177e4 LT	408	if (token[1]) {
cc71229f	409	ret = parse_num(&erase_size, token[1]);
a6550e57	410	if (ret) {
1da177e4	411	parse_err("illegal erase size");
a6550e57	412	}
1da177e4 LT	413	}
	414
	415	add_device(name, erase_size);
	416
	417	return 0;
	418	}
	419
	420
c4e7fb31 VH	421	static int block2mtd_setup(const char val, struct kernel_param kp)
	422	{
	423	#ifdef MODULE
	424	return block2mtd_setup2(val);
	425	#else
	426	/* If more parameters are later passed in via
	427	/sys/module/block2mtd/parameters/block2mtd
	428	and block2mtd_init() has already been called,
	429	we can parse the argument now. */
	430
	431	if (block2mtd_init_called)
	432	return block2mtd_setup2(val);
	433
	434	/* During early boot stage, we only save the parameters
	435	here. We must parse them later: if the param passed
	436	from kernel boot command line, block2mtd_setup() is
	437	called so early that it is not possible to resolve
	438	the device (even kmalloc() fails). Deter that work to
	439	block2mtd_setup2(). */
	440
	441	strlcpy(block2mtd_paramline, val, sizeof(block2mtd_paramline));
	442
	443	return 0;
	444	#endif
	445	}
	446
	447
1da177e4 LT	448	module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
	449	MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>]\"");
	450
	451	static int __init block2mtd_init(void)
	452	{
c4e7fb31	453	int ret = 0;
1da177e4	454	INFO("version " VERSION);
c4e7fb31 VH	455
	456	#ifndef MODULE
	457	if (strlen(block2mtd_paramline))
	458	ret = block2mtd_setup2(block2mtd_paramline);
	459	block2mtd_init_called = 1;
	460	#endif
	461
	462	return ret;
1da177e4 LT	463	}
	464
	465
	466	static void __devexit block2mtd_exit(void)
	467	{
	468	struct list_head pos, next;
	469
	470	/* Remove the MTD devices */
	471	list_for_each_safe(pos, next, &blkmtd_device_list) {
	472	struct block2mtd_dev dev = list_entry(pos, typeof(dev), list);
	473	block2mtd_sync(&dev->mtd);
	474	del_mtd_device(&dev->mtd);
	475	INFO("mtd%d: [%s] removed", dev->mtd.index,
0bc88c59	476	dev->mtd.name + strlen("block2mtd: "));
1da177e4 LT	477	list_del(&dev->list);
	478	block2mtd_free_device(dev);
	479	}
	480	}
	481
	482
	483	module_init(block2mtd_init);
	484	module_exit(block2mtd_exit);
	485
	486	MODULE_LICENSE("GPL");
2b54aaef	487	MODULE_AUTHOR("Joern Engel <joern@lazybastard.org>");
1da177e4	488	MODULE_DESCRIPTION("Emulate an MTD using a block device");