drivers/mtd/mtdpart.c - fp2-dev/kernel/msm - Gitiles

 /*
  * Simple MTD partitioning layer
  *
  * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
  *
  * This code is GPL
  *
  * 	02-21-2002	Thomas Gleixner <gleixner@autronix.de>
  *			added support for read_oob, write_oob
  */

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/list.h>
 #include <linux/kmod.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
 #include <linux/mtd/compatmac.h>

 /* Our partition linked list */
 static LIST_HEAD(mtd_partitions);

 /* Our partition node structure */
 struct mtd_part {
 	struct mtd_info mtd;
 	struct mtd_info *master;
 	uint64_t offset;
 	struct list_head list;
 };

 /*
  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  * the pointer to that structure with this macro.
  */
 #define PART(x)  ((struct mtd_part *)(x))


 /*
  * MTD methods which simply translate the effective address and pass through
  * to the _real_ device.
  */

 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
 		size_t *retlen, u_char *buf)
 {
 	struct mtd_part *part = PART(mtd);
 	struct mtd_ecc_stats stats;
 	int res;

 	stats = part->master->ecc_stats;

 	if (from >= mtd->size)
 		len = 0;
 	else if (from + len > mtd->size)
 		len = mtd->size - from;
 	res = part->master->read(part->master, from + part->offset,
 				   len, retlen, buf);
 	if (unlikely(res)) {
 		if (res == -EUCLEAN)
 			mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
 		if (res == -EBADMSG)
 			mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
 	}
 	return res;
 }

 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
 		size_t *retlen, void **virt, resource_size_t *phys)
 {
 	struct mtd_part *part = PART(mtd);
 	if (from >= mtd->size)
 		len = 0;
 	else if (from + len > mtd->size)
 		len = mtd->size - from;
 	return part->master->point (part->master, from + part->offset,
 				    len, retlen, virt, phys);
 }

 static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
 {
 	struct mtd_part *part = PART(mtd);

 	part->master->unpoint(part->master, from + part->offset, len);
 }

 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
 					    unsigned long len,
 					    unsigned long offset,
 					    unsigned long flags)
 {
 	struct mtd_part *part = PART(mtd);

 	offset += part->offset;
 	return part->master->get_unmapped_area(part->master, len, offset,
 					       flags);
 }

 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 		struct mtd_oob_ops *ops)
 {
 	struct mtd_part *part = PART(mtd);
 	int res;

 	if (from >= mtd->size)
 		return -EINVAL;
 	if (ops->datbuf && from + ops->len > mtd->size)
 		return -EINVAL;
 	res = part->master->read_oob(part->master, from + part->offset, ops);

 	if (unlikely(res)) {
 		if (res == -EUCLEAN)
 			mtd->ecc_stats.corrected++;
 		if (res == -EBADMSG)
 			mtd->ecc_stats.failed++;
 	}
 	return res;
 }

 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 		size_t len, size_t *retlen, u_char *buf)
 {
 	struct mtd_part *part = PART(mtd);
 	return part->master->read_user_prot_reg(part->master, from,
 					len, retlen, buf);
 }

 static int part_get_user_prot_info(struct mtd_info *mtd,
 		struct otp_info *buf, size_t len)
 {
 	struct mtd_part *part = PART(mtd);
 	return part->master->get_user_prot_info(part->master, buf, len);
 }

 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 		size_t len, size_t *retlen, u_char *buf)
 {
 	struct mtd_part *part = PART(mtd);
 	return part->master->read_fact_prot_reg(part->master, from,
 					len, retlen, buf);
 }

 static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
 		size_t len)
 {
 	struct mtd_part *part = PART(mtd);
 	return part->master->get_fact_prot_info(part->master, buf, len);
 }

 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 		size_t *retlen, const u_char *buf)
 {
 	struct mtd_part *part = PART(mtd);
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
 	if (to >= mtd->size)
 		len = 0;
 	else if (to + len > mtd->size)
 		len = mtd->size - to;
 	return part->master->write(part->master, to + part->offset,
 				    len, retlen, buf);
 }

 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 		size_t *retlen, const u_char *buf)
 {
 	struct mtd_part *part = PART(mtd);
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
 	if (to >= mtd->size)
 		len = 0;
 	else if (to + len > mtd->size)
 		len = mtd->size - to;
 	return part->master->panic_write(part->master, to + part->offset,
 				    len, retlen, buf);
 }

 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 		struct mtd_oob_ops *ops)
 {
 	struct mtd_part *part = PART(mtd);

 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;

 	if (to >= mtd->size)
 		return -EINVAL;
 	if (ops->datbuf && to + ops->len > mtd->size)
 		return -EINVAL;
 	return part->master->write_oob(part->master, to + part->offset, ops);
 }

 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 		size_t len, size_t *retlen, u_char *buf)
 {
 	struct mtd_part *part = PART(mtd);
 	return part->master->write_user_prot_reg(part->master, from,
 					len, retlen, buf);
 }

 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 		size_t len)
 {
 	struct mtd_part *part = PART(mtd);
 	return part->master->lock_user_prot_reg(part->master, from, len);
 }

 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 		unsigned long count, loff_t to, size_t *retlen)
 {
 	struct mtd_part *part = PART(mtd);
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
 	return part->master->writev(part->master, vecs, count,
 					to + part->offset, retlen);
 }

 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 {
 	struct mtd_part *part = PART(mtd);
 	int ret;
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
 	if (instr->addr >= mtd->size)
 		return -EINVAL;
 	instr->addr += part->offset;
 	ret = part->master->erase(part->master, instr);
 	if (ret) {
 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 			instr->fail_addr -= part->offset;
 		instr->addr -= part->offset;
 	}
 	return ret;
 }

 void mtd_erase_callback(struct erase_info *instr)
 {
 	if (instr->mtd->erase == part_erase) {
 		struct mtd_part *part = PART(instr->mtd);

 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 			instr->fail_addr -= part->offset;
 		instr->addr -= part->offset;
 	}
 	if (instr->callback)
 		instr->callback(instr);
 }
 EXPORT_SYMBOL_GPL(mtd_erase_callback);

 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
 	struct mtd_part *part = PART(mtd);
 	if ((len + ofs) > mtd->size)
 		return -EINVAL;
 	return part->master->lock(part->master, ofs + part->offset, len);
 }

 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
 	struct mtd_part *part = PART(mtd);
 	if ((len + ofs) > mtd->size)
 		return -EINVAL;
 	return part->master->unlock(part->master, ofs + part->offset, len);
 }

 static void part_sync(struct mtd_info *mtd)
 {
 	struct mtd_part *part = PART(mtd);
 	part->master->sync(part->master);
 }

 static int part_suspend(struct mtd_info *mtd)
 {
 	struct mtd_part *part = PART(mtd);
 	return part->master->suspend(part->master);
 }

 static void part_resume(struct mtd_info *mtd)
 {
 	struct mtd_part *part = PART(mtd);
 	part->master->resume(part->master);
 }

 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 {
 	struct mtd_part *part = PART(mtd);
 	if (ofs >= mtd->size)
 		return -EINVAL;
 	ofs += part->offset;
 	return part->master->block_isbad(part->master, ofs);
 }

 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 {
 	struct mtd_part *part = PART(mtd);
 	int res;

 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
 	if (ofs >= mtd->size)
 		return -EINVAL;
 	ofs += part->offset;
 	res = part->master->block_markbad(part->master, ofs);
 	if (!res)
 		mtd->ecc_stats.badblocks++;
 	return res;
 }

 /*
  * This function unregisters and destroy all slave MTD objects which are
  * attached to the given master MTD object.
  */

 int del_mtd_partitions(struct mtd_info *master)
 {
 	struct mtd_part *slave, *next;

 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 		if (slave->master == master) {
 			list_del(&slave->list);
 			del_mtd_device(&slave->mtd);
 			kfree(slave);
 		}

 	return 0;
 }
 EXPORT_SYMBOL(del_mtd_partitions);

 static struct mtd_part *add_one_partition(struct mtd_info *master,
 		const struct mtd_partition *part, int partno,
 		uint64_t cur_offset)
 {
 	struct mtd_part *slave;

 	/* allocate the partition structure */
 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 	if (!slave) {
 		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 			master->name);
 		del_mtd_partitions(master);
 		return NULL;
 	}
 	list_add(&slave->list, &mtd_partitions);

 	/* set up the MTD object for this partition */
 	slave->mtd.type = master->type;
 	slave->mtd.flags = master->flags & ~part->mask_flags;
 	slave->mtd.size = part->size;
 	slave->mtd.writesize = master->writesize;
 	slave->mtd.oobsize = master->oobsize;
 	slave->mtd.oobavail = master->oobavail;
 	slave->mtd.subpage_sft = master->subpage_sft;

 	slave->mtd.name = part->name;
 	slave->mtd.owner = master->owner;
 	slave->mtd.backing_dev_info = master->backing_dev_info;

 	/* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
 	 * to have the same data be in two different partitions.
 	 */
 	slave->mtd.dev.parent = master->dev.parent;

 	slave->mtd.read = part_read;
 	slave->mtd.write = part_write;

 	if (master->panic_write)
 		slave->mtd.panic_write = part_panic_write;

 	if (master->point && master->unpoint) {
 		slave->mtd.point = part_point;
 		slave->mtd.unpoint = part_unpoint;
 	}

 	if (master->get_unmapped_area)
 		slave->mtd.get_unmapped_area = part_get_unmapped_area;
 	if (master->read_oob)
 		slave->mtd.read_oob = part_read_oob;
 	if (master->write_oob)
 		slave->mtd.write_oob = part_write_oob;
 	if (master->read_user_prot_reg)
 		slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
 	if (master->read_fact_prot_reg)
 		slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
 	if (master->write_user_prot_reg)
 		slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
 	if (master->lock_user_prot_reg)
 		slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
 	if (master->get_user_prot_info)
 		slave->mtd.get_user_prot_info = part_get_user_prot_info;
 	if (master->get_fact_prot_info)
 		slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
 	if (master->sync)
 		slave->mtd.sync = part_sync;
 	if (!partno && !master->dev.class && master->suspend && master->resume) {
 			slave->mtd.suspend = part_suspend;
 			slave->mtd.resume = part_resume;
 	}
 	if (master->writev)
 		slave->mtd.writev = part_writev;
 	if (master->lock)
 		slave->mtd.lock = part_lock;
 	if (master->unlock)
 		slave->mtd.unlock = part_unlock;
 	if (master->block_isbad)
 		slave->mtd.block_isbad = part_block_isbad;
 	if (master->block_markbad)
 		slave->mtd.block_markbad = part_block_markbad;
 	slave->mtd.erase = part_erase;
 	slave->master = master;
 	slave->offset = part->offset;

 	if (slave->offset == MTDPART_OFS_APPEND)
 		slave->offset = cur_offset;
 	if (slave->offset == MTDPART_OFS_NXTBLK) {
 		slave->offset = cur_offset;
 		if (mtd_mod_by_eb(cur_offset, master) != 0) {
 			/* Round up to next erasesize */
 			slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 			printk(KERN_NOTICE "Moving partition %d: "
 			       "0x%012llx -> 0x%012llx\n", partno,
 			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 		}
 	}
 	if (slave->mtd.size == MTDPART_SIZ_FULL)
 		slave->mtd.size = master->size - slave->offset;

 	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);

 	/* let's do some sanity checks */
 	if (slave->offset >= master->size) {
 		/* let's register it anyway to preserve ordering */
 		slave->offset = 0;
 		slave->mtd.size = 0;
 		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 			part->name);
 		goto out_register;
 	}
 	if (slave->offset + slave->mtd.size > master->size) {
 		slave->mtd.size = master->size - slave->offset;
 		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 			part->name, master->name, (unsigned long long)slave->mtd.size);
 	}
 	if (master->numeraseregions > 1) {
 		/* Deal with variable erase size stuff */
 		int i, max = master->numeraseregions;
 		u64 end = slave->offset + slave->mtd.size;
 		struct mtd_erase_region_info *regions = master->eraseregions;

 		/* Find the first erase regions which is part of this
 		 * partition. */
 		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 			;
 		/* The loop searched for the region _behind_ the first one */
 		if (i > 0)
 			i--;

 		/* Pick biggest erasesize */
 		for (; i < max && regions[i].offset < end; i++) {
 			if (slave->mtd.erasesize < regions[i].erasesize) {
 				slave->mtd.erasesize = regions[i].erasesize;
 			}
 		}
 		BUG_ON(slave->mtd.erasesize == 0);
 	} else {
 		/* Single erase size */
 		slave->mtd.erasesize = master->erasesize;
 	}

 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
 	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 		/* Doesn't start on a boundary of major erase size */
 		/* FIXME: Let it be writable if it is on a boundary of
 		 * _minor_ erase size though */
 		slave->mtd.flags &= ~MTD_WRITEABLE;
 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 			part->name);
 	}
 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
 	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 		slave->mtd.flags &= ~MTD_WRITEABLE;
 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 			part->name);
 	}

 	slave->mtd.ecclayout = master->ecclayout;
 	if (master->block_isbad) {
 		uint64_t offs = 0;

 		while (offs < slave->mtd.size) {
 			if (master->block_isbad(master,
 						offs + slave->offset))
 				slave->mtd.ecc_stats.badblocks++;
 			offs += slave->mtd.erasesize;
 		}
 	}

 out_register:
 	/* register our partition */
 	add_mtd_device(&slave->mtd);

 	return slave;
 }

 /*
  * This function, given a master MTD object and a partition table, creates
  * and registers slave MTD objects which are bound to the master according to
  * the partition definitions.
  *
  * We don't register the master, or expect the caller to have done so,
  * for reasons of data integrity.
  */

 int add_mtd_partitions(struct mtd_info *master,
 		       const struct mtd_partition *parts,
 		       int nbparts)
 {
 	struct mtd_part *slave;
 	uint64_t cur_offset = 0;
 	int i;

 	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);

 	for (i = 0; i < nbparts; i++) {
 		slave = add_one_partition(master, parts + i, i, cur_offset);
 		if (!slave)
 			return -ENOMEM;
 		cur_offset = slave->offset + slave->mtd.size;
 	}

 	return 0;
 }
 EXPORT_SYMBOL(add_mtd_partitions);

 static DEFINE_SPINLOCK(part_parser_lock);
 static LIST_HEAD(part_parsers);

 static struct mtd_part_parser *get_partition_parser(const char *name)
 {
 	struct mtd_part_parser *p, *ret = NULL;

 	spin_lock(&part_parser_lock);

 	list_for_each_entry(p, &part_parsers, list)
 		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 			ret = p;
 			break;
 		}

 	spin_unlock(&part_parser_lock);

 	return ret;
 }

 int register_mtd_parser(struct mtd_part_parser *p)
 {
 	spin_lock(&part_parser_lock);
 	list_add(&p->list, &part_parsers);
 	spin_unlock(&part_parser_lock);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(register_mtd_parser);

 int deregister_mtd_parser(struct mtd_part_parser *p)
 {
 	spin_lock(&part_parser_lock);
 	list_del(&p->list);
 	spin_unlock(&part_parser_lock);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(deregister_mtd_parser);

 int parse_mtd_partitions(struct mtd_info *master, const char **types,
 			 struct mtd_partition **pparts, unsigned long origin)
 {
 	struct mtd_part_parser *parser;
 	int ret = 0;

 	for ( ; ret <= 0 && *types; types++) {
 		parser = get_partition_parser(*types);
 		if (!parser && !request_module("%s", *types))
 				parser = get_partition_parser(*types);
 		if (!parser) {
 			printk(KERN_NOTICE "%s partition parsing not available\n",
 			       *types);
 			continue;
 		}
 		ret = (*parser->parse_fn)(master, pparts, origin);
 		if (ret > 0) {
 			printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 			       ret, parser->name, master->name);
 		}
 		put_partition_parser(parser);
 	}
 	return ret;
 }
 EXPORT_SYMBOL_GPL(parse_mtd_partitions);
	/*
	* Simple MTD partitioning layer
	*
	* (C) 2000 Nicolas Pitre <nico@fluxnic.net>
	*
	* This code is GPL
	*
	* 02-21-2002 Thomas Gleixner <gleixner@autronix.de>
	* added support for read_oob, write_oob
	*/

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/list.h>
	#include <linux/kmod.h>
	#include <linux/mtd/mtd.h>
	#include <linux/mtd/partitions.h>
	#include <linux/mtd/compatmac.h>

	/* Our partition linked list */
	static LIST_HEAD(mtd_partitions);

	/* Our partition node structure */
	struct mtd_part {
	struct mtd_info mtd;
	struct mtd_info *master;
	uint64_t offset;
	struct list_head list;
	};

	/*
	* Given a pointer to the MTD object in the mtd_part structure, we can retrieve
	* the pointer to that structure with this macro.
	*/
	#define PART(x) ((struct mtd_part *)(x))


	/*
	* MTD methods which simply translate the effective address and pass through
	* to the _real_ device.
	*/

	static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
	size_t retlen, u_char buf)
	{
	struct mtd_part *part = PART(mtd);
	struct mtd_ecc_stats stats;
	int res;

	stats = part->master->ecc_stats;

	if (from >= mtd->size)
	len = 0;
	else if (from + len > mtd->size)
	len = mtd->size - from;
	res = part->master->read(part->master, from + part->offset,
	len, retlen, buf);
	if (unlikely(res)) {
	if (res == -EUCLEAN)
	mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
	if (res == -EBADMSG)
	mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
	}
	return res;
	}

	static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
	size_t retlen, void virt, resource_size_t phys)
	{
	struct mtd_part *part = PART(mtd);
	if (from >= mtd->size)
	len = 0;
	else if (from + len > mtd->size)
	len = mtd->size - from;
	return part->master->point (part->master, from + part->offset,
	len, retlen, virt, phys);
	}

	static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
	{
	struct mtd_part *part = PART(mtd);

	part->master->unpoint(part->master, from + part->offset, len);
	}

	static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
	unsigned long len,
	unsigned long offset,
	unsigned long flags)
	{
	struct mtd_part *part = PART(mtd);

	offset += part->offset;
	return part->master->get_unmapped_area(part->master, len, offset,
	flags);
	}

	static int part_read_oob(struct mtd_info *mtd, loff_t from,
	struct mtd_oob_ops *ops)
	{
	struct mtd_part *part = PART(mtd);
	int res;

	if (from >= mtd->size)
	return -EINVAL;
	if (ops->datbuf && from + ops->len > mtd->size)
	return -EINVAL;
	res = part->master->read_oob(part->master, from + part->offset, ops);

	if (unlikely(res)) {
	if (res == -EUCLEAN)
	mtd->ecc_stats.corrected++;
	if (res == -EBADMSG)
	mtd->ecc_stats.failed++;
	}
	return res;
	}

	static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
	size_t len, size_t retlen, u_char buf)
	{
	struct mtd_part *part = PART(mtd);
	return part->master->read_user_prot_reg(part->master, from,
	len, retlen, buf);
	}

	static int part_get_user_prot_info(struct mtd_info *mtd,
	struct otp_info *buf, size_t len)
	{
	struct mtd_part *part = PART(mtd);
	return part->master->get_user_prot_info(part->master, buf, len);
	}

	static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
	size_t len, size_t retlen, u_char buf)
	{
	struct mtd_part *part = PART(mtd);
	return part->master->read_fact_prot_reg(part->master, from,
	len, retlen, buf);
	}

	static int part_get_fact_prot_info(struct mtd_info mtd, struct otp_info buf,
	size_t len)
	{
	struct mtd_part *part = PART(mtd);
	return part->master->get_fact_prot_info(part->master, buf, len);
	}

	static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
	size_t retlen, const u_char buf)
	{
	struct mtd_part *part = PART(mtd);
	if (!(mtd->flags & MTD_WRITEABLE))
	return -EROFS;
	if (to >= mtd->size)
	len = 0;
	else if (to + len > mtd->size)
	len = mtd->size - to;
	return part->master->write(part->master, to + part->offset,
	len, retlen, buf);
	}

	static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
	size_t retlen, const u_char buf)
	{
	struct mtd_part *part = PART(mtd);
	if (!(mtd->flags & MTD_WRITEABLE))
	return -EROFS;
	if (to >= mtd->size)
	len = 0;
	else if (to + len > mtd->size)
	len = mtd->size - to;
	return part->master->panic_write(part->master, to + part->offset,
	len, retlen, buf);
	}

	static int part_write_oob(struct mtd_info *mtd, loff_t to,
	struct mtd_oob_ops *ops)
	{
	struct mtd_part *part = PART(mtd);

	if (!(mtd->flags & MTD_WRITEABLE))
	return -EROFS;

	if (to >= mtd->size)
	return -EINVAL;
	if (ops->datbuf && to + ops->len > mtd->size)
	return -EINVAL;
	return part->master->write_oob(part->master, to + part->offset, ops);
	}

	static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
	size_t len, size_t retlen, u_char buf)
	{
	struct mtd_part *part = PART(mtd);
	return part->master->write_user_prot_reg(part->master, from,
	len, retlen, buf);
	}

	static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
	size_t len)
	{
	struct mtd_part *part = PART(mtd);
	return part->master->lock_user_prot_reg(part->master, from, len);
	}

	static int part_writev(struct mtd_info mtd, const struct kvec vecs,
	unsigned long count, loff_t to, size_t *retlen)
	{
	struct mtd_part *part = PART(mtd);
	if (!(mtd->flags & MTD_WRITEABLE))
	return -EROFS;
	return part->master->writev(part->master, vecs, count,
	to + part->offset, retlen);
	}

	static int part_erase(struct mtd_info mtd, struct erase_info instr)
	{
	struct mtd_part *part = PART(mtd);
	int ret;
	if (!(mtd->flags & MTD_WRITEABLE))
	return -EROFS;
	if (instr->addr >= mtd->size)
	return -EINVAL;
	instr->addr += part->offset;
	ret = part->master->erase(part->master, instr);
	if (ret) {
	if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
	instr->fail_addr -= part->offset;
	instr->addr -= part->offset;
	}
	return ret;
	}

	void mtd_erase_callback(struct erase_info *instr)
	{
	if (instr->mtd->erase == part_erase) {
	struct mtd_part *part = PART(instr->mtd);

	if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
	instr->fail_addr -= part->offset;
	instr->addr -= part->offset;
	}
	if (instr->callback)
	instr->callback(instr);
	}
	EXPORT_SYMBOL_GPL(mtd_erase_callback);

	static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
	{
	struct mtd_part *part = PART(mtd);
	if ((len + ofs) > mtd->size)
	return -EINVAL;
	return part->master->lock(part->master, ofs + part->offset, len);
	}

	static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
	{
	struct mtd_part *part = PART(mtd);
	if ((len + ofs) > mtd->size)
	return -EINVAL;
	return part->master->unlock(part->master, ofs + part->offset, len);
	}

	static void part_sync(struct mtd_info *mtd)
	{
	struct mtd_part *part = PART(mtd);
	part->master->sync(part->master);
	}

	static int part_suspend(struct mtd_info *mtd)
	{
	struct mtd_part *part = PART(mtd);
	return part->master->suspend(part->master);
	}

	static void part_resume(struct mtd_info *mtd)
	{
	struct mtd_part *part = PART(mtd);
	part->master->resume(part->master);
	}

	static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
	{
	struct mtd_part *part = PART(mtd);
	if (ofs >= mtd->size)
	return -EINVAL;
	ofs += part->offset;
	return part->master->block_isbad(part->master, ofs);
	}

	static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
	{
	struct mtd_part *part = PART(mtd);
	int res;

	if (!(mtd->flags & MTD_WRITEABLE))
	return -EROFS;
	if (ofs >= mtd->size)
	return -EINVAL;
	ofs += part->offset;
	res = part->master->block_markbad(part->master, ofs);
	if (!res)
	mtd->ecc_stats.badblocks++;
	return res;
	}

	/*
	* This function unregisters and destroy all slave MTD objects which are
	* attached to the given master MTD object.
	*/

	int del_mtd_partitions(struct mtd_info *master)
	{
	struct mtd_part slave, next;

	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
	if (slave->master == master) {
	list_del(&slave->list);
	del_mtd_device(&slave->mtd);
	kfree(slave);
	}

	return 0;
	}
	EXPORT_SYMBOL(del_mtd_partitions);

	static struct mtd_part add_one_partition(struct mtd_info master,
	const struct mtd_partition *part, int partno,
	uint64_t cur_offset)
	{
	struct mtd_part *slave;

	/* allocate the partition structure */
	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
	if (!slave) {
	printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
	master->name);
	del_mtd_partitions(master);
	return NULL;
	}
	list_add(&slave->list, &mtd_partitions);

	/* set up the MTD object for this partition */
	slave->mtd.type = master->type;
	slave->mtd.flags = master->flags & ~part->mask_flags;
	slave->mtd.size = part->size;
	slave->mtd.writesize = master->writesize;
	slave->mtd.oobsize = master->oobsize;
	slave->mtd.oobavail = master->oobavail;
	slave->mtd.subpage_sft = master->subpage_sft;

	slave->mtd.name = part->name;
	slave->mtd.owner = master->owner;
	slave->mtd.backing_dev_info = master->backing_dev_info;

	/* NOTE: we don't arrange MTDs as a tree; it'd be error-prone
	* to have the same data be in two different partitions.
	*/
	slave->mtd.dev.parent = master->dev.parent;

	slave->mtd.read = part_read;
	slave->mtd.write = part_write;

	if (master->panic_write)
	slave->mtd.panic_write = part_panic_write;

	if (master->point && master->unpoint) {
	slave->mtd.point = part_point;
	slave->mtd.unpoint = part_unpoint;
	}

	if (master->get_unmapped_area)
	slave->mtd.get_unmapped_area = part_get_unmapped_area;
	if (master->read_oob)
	slave->mtd.read_oob = part_read_oob;
	if (master->write_oob)
	slave->mtd.write_oob = part_write_oob;
	if (master->read_user_prot_reg)
	slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
	if (master->read_fact_prot_reg)
	slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
	if (master->write_user_prot_reg)
	slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
	if (master->lock_user_prot_reg)
	slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
	if (master->get_user_prot_info)
	slave->mtd.get_user_prot_info = part_get_user_prot_info;
	if (master->get_fact_prot_info)
	slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
	if (master->sync)
	slave->mtd.sync = part_sync;
	if (!partno && !master->dev.class && master->suspend && master->resume) {
	slave->mtd.suspend = part_suspend;
	slave->mtd.resume = part_resume;
	}
	if (master->writev)
	slave->mtd.writev = part_writev;
	if (master->lock)
	slave->mtd.lock = part_lock;
	if (master->unlock)
	slave->mtd.unlock = part_unlock;
	if (master->block_isbad)
	slave->mtd.block_isbad = part_block_isbad;
	if (master->block_markbad)
	slave->mtd.block_markbad = part_block_markbad;
	slave->mtd.erase = part_erase;
	slave->master = master;
	slave->offset = part->offset;

	if (slave->offset == MTDPART_OFS_APPEND)
	slave->offset = cur_offset;
	if (slave->offset == MTDPART_OFS_NXTBLK) {
	slave->offset = cur_offset;
	if (mtd_mod_by_eb(cur_offset, master) != 0) {
	/* Round up to next erasesize */
	slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
	printk(KERN_NOTICE "Moving partition %d: "
	"0x%012llx -> 0x%012llx\n", partno,
	(unsigned long long)cur_offset, (unsigned long long)slave->offset);
	}
	}
	if (slave->mtd.size == MTDPART_SIZ_FULL)
	slave->mtd.size = master->size - slave->offset;

	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
	(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);

	/* let's do some sanity checks */
	if (slave->offset >= master->size) {
	/* let's register it anyway to preserve ordering */
	slave->offset = 0;
	slave->mtd.size = 0;
	printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
	part->name);
	goto out_register;
	}
	if (slave->offset + slave->mtd.size > master->size) {
	slave->mtd.size = master->size - slave->offset;
	printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
	part->name, master->name, (unsigned long long)slave->mtd.size);
	}
	if (master->numeraseregions > 1) {
	/* Deal with variable erase size stuff */
	int i, max = master->numeraseregions;
	u64 end = slave->offset + slave->mtd.size;
	struct mtd_erase_region_info *regions = master->eraseregions;

	/* Find the first erase regions which is part of this
	* partition. */
	for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
	;
	/* The loop searched for the region _behind_ the first one */
	if (i > 0)
	i--;

	/* Pick biggest erasesize */
	for (; i < max && regions[i].offset < end; i++) {
	if (slave->mtd.erasesize < regions[i].erasesize) {
	slave->mtd.erasesize = regions[i].erasesize;
	}
	}
	BUG_ON(slave->mtd.erasesize == 0);
	} else {
	/* Single erase size */
	slave->mtd.erasesize = master->erasesize;
	}

	if ((slave->mtd.flags & MTD_WRITEABLE) &&
	mtd_mod_by_eb(slave->offset, &slave->mtd)) {
	/* Doesn't start on a boundary of major erase size */
	/* FIXME: Let it be writable if it is on a boundary of
	* _minor_ erase size though */
	slave->mtd.flags &= ~MTD_WRITEABLE;
	printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
	part->name);
	}
	if ((slave->mtd.flags & MTD_WRITEABLE) &&
	mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
	slave->mtd.flags &= ~MTD_WRITEABLE;
	printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
	part->name);
	}

	slave->mtd.ecclayout = master->ecclayout;
	if (master->block_isbad) {
	uint64_t offs = 0;

	while (offs < slave->mtd.size) {
	if (master->block_isbad(master,
	offs + slave->offset))
	slave->mtd.ecc_stats.badblocks++;
	offs += slave->mtd.erasesize;
	}
	}

	out_register:
	/* register our partition */
	add_mtd_device(&slave->mtd);

	return slave;
	}

	/*
	* This function, given a master MTD object and a partition table, creates
	* and registers slave MTD objects which are bound to the master according to
	* the partition definitions.
	*
	* We don't register the master, or expect the caller to have done so,
	* for reasons of data integrity.
	*/

	int add_mtd_partitions(struct mtd_info *master,
	const struct mtd_partition *parts,
	int nbparts)
	{
	struct mtd_part *slave;
	uint64_t cur_offset = 0;
	int i;

	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);

	for (i = 0; i < nbparts; i++) {
	slave = add_one_partition(master, parts + i, i, cur_offset);
	if (!slave)
	return -ENOMEM;
	cur_offset = slave->offset + slave->mtd.size;
	}

	return 0;
	}
	EXPORT_SYMBOL(add_mtd_partitions);

	static DEFINE_SPINLOCK(part_parser_lock);
	static LIST_HEAD(part_parsers);

	static struct mtd_part_parser get_partition_parser(const char name)
	{
	struct mtd_part_parser p, ret = NULL;

	spin_lock(&part_parser_lock);

	list_for_each_entry(p, &part_parsers, list)
	if (!strcmp(p->name, name) && try_module_get(p->owner)) {
	ret = p;
	break;
	}

	spin_unlock(&part_parser_lock);

	return ret;
	}

	int register_mtd_parser(struct mtd_part_parser *p)
	{
	spin_lock(&part_parser_lock);
	list_add(&p->list, &part_parsers);
	spin_unlock(&part_parser_lock);

	return 0;
	}
	EXPORT_SYMBOL_GPL(register_mtd_parser);

	int deregister_mtd_parser(struct mtd_part_parser *p)
	{
	spin_lock(&part_parser_lock);
	list_del(&p->list);
	spin_unlock(&part_parser_lock);
	return 0;
	}
	EXPORT_SYMBOL_GPL(deregister_mtd_parser);

	int parse_mtd_partitions(struct mtd_info master, const char *types,
	struct mtd_partition **pparts, unsigned long origin)
	{
	struct mtd_part_parser *parser;
	int ret = 0;

	for ( ; ret <= 0 && *types; types++) {
	parser = get_partition_parser(*types);
	if (!parser && !request_module("%s", *types))
	parser = get_partition_parser(*types);
	if (!parser) {
	printk(KERN_NOTICE "%s partition parsing not available\n",
	*types);
	continue;
	}
	ret = (*parser->parse_fn)(master, pparts, origin);
	if (ret > 0) {
	printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
	ret, parser->name, master->name);
	}
	put_partition_parser(parser);
	}
	return ret;
	}
	EXPORT_SYMBOL_GPL(parse_mtd_partitions);