/* * Simple MTD partitioning layer * * (C) 2000 Nicolas Pitre <nico@cam.org> * * This code is GPL * * $Id: mtdpart.c,v 1.1 2002/05/22 12:38:56 wookey Exp $ */#include <linux/module.h>#include <linux/types.h>#include <linux/kernel.h>#include <linux/slab.h>#include <linux/list.h>#include <linux/mtd/mtd.h>#include <linux/mtd/partitions.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;	u_int32_t offset;	int index;	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);	if (from >= mtd->size)		len = 0;	else if (from + len > mtd->size)		len = mtd->size - from;	return part->master->read (part->master, from + part->offset, 					len, retlen, buf);}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_writev (struct mtd_info *mtd,  const struct iovec *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_readv (struct mtd_info *mtd,  struct iovec *vecs,			 unsigned long count, loff_t from, size_t *retlen){	struct mtd_part *part = PART(mtd);	return part->master->readv (part->master, vecs, count,					from + part->offset, retlen);}static int part_erase (struct mtd_info *mtd, struct erase_info *instr){	struct mtd_part *part = PART(mtd);	if (!(mtd->flags & MTD_WRITEABLE))		return -EROFS;	if (instr->addr >= mtd->size)		return -EINVAL;	instr->addr += part->offset;	return part->master->erase(part->master, instr);}static int part_lock (struct mtd_info *mtd, loff_t ofs, size_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, size_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);}/*  * 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 list_head *node;	struct mtd_part *slave;	for (node = mtd_partitions.next;	     node != &mtd_partitions;	     node = node->next) {		slave = list_entry(node, struct mtd_part, list);		if (slave->master == master) {			struct list_head *prev = node->prev;			__list_del(prev, node->next);			del_mtd_device(&slave->mtd);			kfree(slave);			node = prev;		}	}	return 0;}/* * 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, 		       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++) {		/* allocate the partition structure */		slave = kmalloc (sizeof(*slave), GFP_KERNEL);		if (!slave) {			printk ("memory allocation error while creating partitions for \"%s\"\n",				master->name);			del_mtd_partitions(master);			return -ENOMEM;		}		memset(slave, 0, sizeof(*slave));		list_add(&slave->list, &mtd_partitions);		/* set up the MTD object for this partition */		slave->mtd.type = master->type;		slave->mtd.flags = master->flags & ~parts[i].mask_flags;		slave->mtd.size = parts[i].size;		slave->mtd.oobblock = master->oobblock;		slave->mtd.oobsize = master->oobsize;		slave->mtd.ecctype = master->ecctype;		slave->mtd.eccsize = master->eccsize;		slave->mtd.name = parts[i].name;		slave->mtd.bank_size = master->bank_size;		slave->mtd.module = master->module;		slave->mtd.read = part_read;		slave->mtd.write = part_write;		if (master->sync)			slave->mtd.sync = part_sync;		if (!i && master->suspend && master->resume) {				slave->mtd.suspend = part_suspend;				slave->mtd.resume = part_resume;		}		if (master->writev)			slave->mtd.writev = part_writev;		if (master->readv)			slave->mtd.readv = part_readv;		if (master->lock)			slave->mtd.lock = part_lock;		if (master->unlock)			slave->mtd.unlock = part_unlock;/* cdhm: fix add oob functions to partitions */		if (master->read_oob)			slave->mtd.read_oob = master->read_oob;		if (master->write_oob)			slave->mtd.write_oob = master->write_oob;/* cdhm: end of fix */		slave->mtd.erase = part_erase;		slave->master = master;		slave->offset = parts[i].offset;		slave->index = i;		if (slave->offset == MTDPART_OFS_APPEND)			slave->offset = cur_offset;		if (slave->mtd.size == MTDPART_SIZ_FULL)			slave->mtd.size = master->size - slave->offset;		cur_offset = slave->offset + slave->mtd.size;			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 ("mtd: partition \"%s\" is out of reach -- disabled\n",				parts[i].name);		}		if (slave->offset + slave->mtd.size > master->size) {			slave->mtd.size = master->size - slave->offset;			printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",				parts[i].name, master->name, slave->mtd.size);		}		if (master->numeraseregions>1) {			/* Deal with variable erase size stuff */			int i;			struct mtd_erase_region_info *regions = master->eraseregions;						/* Find the first erase regions which is part of this partition. */			for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)				;			for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {				if (slave->mtd.erasesize < regions[i].erasesize) {					slave->mtd.erasesize = regions[i].erasesize;				}			}		} 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 ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",				parts[i].name);		}		if ((slave->mtd.flags & MTD_WRITEABLE) && 		    (slave->mtd.size % slave->mtd.erasesize)) {			slave->mtd.flags &= ~MTD_WRITEABLE;			printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",				parts[i].name);		}		/* register our partition */		add_mtd_device(&slave->mtd);	}	return 0;}EXPORT_SYMBOL(add_mtd_partitions);EXPORT_SYMBOL(del_mtd_partitions);MODULE_LICENSE("GPL");MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>");MODULE_DESCRIPTION("Generic support for partitioning of MTD devices");