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/*

 * Simple MTD partitioning layer

 *

 * (C) 2000 Nicolas Pitre <nico@cam.org>

 *

 * This code is GPL

 *

 * $Id: mtdpart.c,v 1.1.1.1 2004-04-15 01:51:43 phoenix Exp $

 *

 *      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/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;

        int registered;

};

/*

 * 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_point (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->point (part->master, from + part->offset,

                                    len, retlen, buf);

}

static void part_unpoint (struct mtd_info *mtd, u_char *addr, loff_t from, size_t len)

{

        struct mtd_part *part = PART(mtd);

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

}

static int part_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,

                        size_t *retlen, u_char *buf, u_char *eccbuf, int oobsel)

{

        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_ecc (part->master, from + part->offset,

                                        len, retlen, buf, eccbuf, oobsel);

}

static int part_read_oob (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_oob (part->master, from + part->offset,

                                        len, retlen, buf);

}

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_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_user_prot_reg (part->master, from,

                                        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_write_ecc (struct mtd_info *mtd, loff_t to, size_t len,

                        size_t *retlen, const u_char *buf,

                         u_char *eccbuf, int oobsel)

{

        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_ecc (part->master, to + part->offset,

                                        len, retlen, buf, eccbuf, oobsel);

}

static int part_write_oob (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_oob (part->master, to + part->offset,

                                        len, retlen, buf);

}

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_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_writev_ecc (struct mtd_info *mtd,  const struct iovec *vecs,

                         unsigned long count, loff_t to, size_t *retlen,

                         u_char *eccbuf, int oobsel)

{

        struct mtd_part *part = PART(mtd);

        if (!(mtd->flags & MTD_WRITEABLE))

                return -EROFS;

        return part->master->writev_ecc (part->master, vecs, count,

                                        to + part->offset, retlen,

                                        eccbuf, oobsel);

}

static int part_readv_ecc (struct mtd_info *mtd,  struct iovec *vecs,

                         unsigned long count, loff_t from, size_t *retlen,

                         u_char *eccbuf, int oobsel)

{

        struct mtd_part *part = PART(mtd);

        return part->master->readv_ecc (part->master, vecs, count,

                                        from + part->offset, retlen,

                                        eccbuf, oobsel);

}

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);

                        if(slave->registered)

                                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->point && master->unpoint){

                        slave->mtd.point = part_point;

                        slave->mtd.unpoint = part_unpoint;

                }

                if (master->read_ecc)

                        slave->mtd.read_ecc = part_read_ecc;

                if (master->write_ecc)

                        slave->mtd.write_ecc = part_write_ecc;

                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->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->writev_ecc)

                        slave->mtd.writev_ecc = part_writev_ecc;

                if (master->readv_ecc)

                        slave->mtd.readv_ecc = part_readv_ecc;

                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->offset == MTDPART_OFS_NXTBLK) {

                        u_int32_t emask = master->erasesize-1;

                        slave->offset = (cur_offset + emask) & ~emask;

                        if (slave->offset != cur_offset) {

                                printk(KERN_NOTICE "Moving partition %d: "

                                       "0x%08x -> 0x%08x\n", i,

                                       cur_offset, slave->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);

                }

                if(parts[i].mtdp)

                {       /* store the object pointer (caller may or may not register it */

                        *parts[i].mtdp = &slave->mtd;

                        slave->registered = 0;

                }

                else

                {

                        /* register our partition */

                        add_mtd_device(&slave->mtd);

                        slave->registered = 1;

                }

        }

        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");