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/*
* Simple MTD partitioning layer
*
* (C) 2000 Nicolas Pitre <nico@cam.org>
*
* This code is GPL
*
* $Id: mtdpart.c,v 1.23 2001/10/02 15:05:11 dwmw2 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;
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");
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