mtdpart.c

基于linux-2.6.28的mtd驱动

		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);
			if (slave->registered)
				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,
		u_int32_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.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->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->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;
	slave->index = partno;

	if (slave->offset == MTDPART_OFS_APPEND)
		slave->offset = cur_offset;
	if (slave->offset == MTDPART_OFS_NXTBLK) {
		slave->offset = cur_offset;
		if ((cur_offset % master->erasesize) != 0) {
			/* Round up to next erasesize */
			slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
			printk(KERN_NOTICE "Moving partition %d: "
			       "0x%08x -> 0x%08x\n", partno,
			       cur_offset, slave->offset);
		}
	}
	if (slave->mtd.size == MTDPART_SIZ_FULL)
		slave->mtd.size = master->size - slave->offset;

	printk(KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
		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 %#x\n",
			part->name, master->name, slave->mtd.size);
	}
	if (master->numeraseregions > 1) {
		/* Deal with variable erase size stuff */
		int i, max = master->numeraseregions;
		u32 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 */
		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) &&
	    (slave->offset % slave->mtd.erasesize)) {
		/* 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) &&
	    (slave->mtd.size % slave->mtd.erasesize)) {
		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) {
		uint32_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:
	if (part->mtdp) {
		/* store the object pointer (caller may or may not register it*/
		*part->mtdp = &slave->mtd;
		slave->registered = 0;
	} else {
		/* register our partition */
		add_mtd_device(&slave->mtd);
		slave->registered = 1;
	}
	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.
 * (Q: should we register the master MTD object as well?)
 */

int add_mtd_partitions(struct mtd_info *master,
		       const struct mtd_partition *parts,
		       int nbparts)
{
	struct mtd_part *slave;
	u_int32_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);