mtdpart.c

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/*
 * Simple MTD partitioning layer
 *
 * Copyright © 2000 Nicolas Pitre <[email protected]>
 * Copyright © 2002 Thomas Gleixner <[email protected]>
 * Copyright © 2000-2010 David Woodhouse <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#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/err.h>

#include "mtdcore.h"

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

/* 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;
    res = part->master->_read(part->master, from + part->offset, len,
                  retlen, buf);
    if (unlikely(mtd_is_eccerr(res)))
        mtd->ecc_stats.failed +=
            part->master->ecc_stats.failed - stats.failed;
    else
        mtd->ecc_stats.corrected +=
            part->master->ecc_stats.corrected - stats.corrected;
    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);

    return part->master->_point(part->master, from + part->offset, len,
                    retlen, virt, phys);
}

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

    return 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;

    /*
     * If OOB is also requested, make sure that we do not read past the end
     * of this partition.
     */
    if (ops->oobbuf) {
        size_t len, pages;

        if (ops->mode == MTD_OPS_AUTO_OOB)
            len = mtd->oobavail;
        else
            len = mtd->oobsize;
        pages = mtd_div_by_ws(mtd->size, mtd);
        pages -= mtd_div_by_ws(from, mtd);
        if (ops->ooboffs + ops->ooblen > pages * len)
            return -EINVAL;
    }

    res = part->master->_read_oob(part->master, from + part->offset, ops);
    if (unlikely(res)) {
        if (mtd_is_bitflip(res))
            mtd->ecc_stats.corrected++;
        if (mtd_is_eccerr(res))
            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);
    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);
    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 (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);
    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;

    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);
    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);
    return part->master->_unlock(part->master, ofs + part->offset, len);
}

static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
    struct mtd_part *part = PART(mtd);
    return part->master->_is_locked(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);
    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;

    ofs += part->offset;
    res = part->master->_block_markbad(part->master, ofs);
    if (!res)
        mtd->ecc_stats.badblocks++;
    return res;
}

static inline void free_partition(struct mtd_part *p)
{
    kfree(p->mtd.name);
    kfree(p);
}

/*
 * 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;
    int ret, err = 0;

    mutex_lock(&mtd_partitions_mutex);
    list_for_each_entry_safe(slave, next, &mtd_partitions, list)
        if (slave->master == master) {
            ret = del_mtd_device(&slave->mtd);
            if (ret < 0) {
                err = ret;
                continue;
            }
            list_del(&slave->list);
            free_partition(slave);
        }
    mutex_unlock(&mtd_partitions_mutex);

    return err;
}

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

    /* allocate the partition structure */
    slave = kzalloc(sizeof(*slave), GFP_KERNEL);
    name = kstrdup(part->name, GFP_KERNEL);
    if (!name || !slave) {
        printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
               master->name);
        kfree(name);
        kfree(slave);
        return ERR_PTR(-ENOMEM);
    }

    /* 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.writebufsize = master->writebufsize;
    slave->mtd.oobsize = master->oobsize;
    slave->mtd.oobavail = master->oobavail;
    slave->mtd.subpage_sft = master->subpage_sft;

    slave->mtd.name = 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->_is_locked)
        slave->mtd._is_locked = part_is_locked;
    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->offset == MTDPART_OFS_RETAIN) {
        slave->offset = cur_offset;
        if (master->size - slave->offset >= slave->mtd.size) {
            slave->mtd.size = master->size - slave->offset
                            - slave->mtd.size;
        } else {
            printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
                part->name, master->size - slave->offset,
                slave->mtd.size);
            /* register to preserve ordering */
            goto out_register;
        }
    }
    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;
    slave->mtd.ecc_strength = master->ecc_strength;
    slave->mtd.bitflip_threshold = master->bitflip_threshold;

    if (master->_block_isbad) {
        uint64_t offs = 0;

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

out_register:
    return slave;
}

int mtd_add_partition(struct mtd_info *master, char *name,
              long long offset, long long length)
{
    struct mtd_partition part;
    struct mtd_part *p, *new;
    uint64_t start, end;
    int ret = 0;

    /* the direct offset is expected */
    if (offset == MTDPART_OFS_APPEND ||
        offset == MTDPART_OFS_NXTBLK)
        return -EINVAL;

    if (length == MTDPART_SIZ_FULL)
        length = master->size - offset;

    if (length <= 0)
        return -EINVAL;

    part.name = name;
    part.size = length;
    part.offset = offset;
    part.mask_flags = 0;
    part.ecclayout = NULL;

    new = allocate_partition(master, &part, -1, offset);
    if (IS_ERR(new))
        return PTR_ERR(new);

    start = offset;
    end = offset + length;

    mutex_lock(&mtd_partitions_mutex);
    list_for_each_entry(p, &mtd_partitions, list)
        if (p->master == master) {
            if ((start >= p->offset) &&
                (start < (p->offset + p->mtd.size)))
                goto err_inv;

            if ((end >= p->offset) &&
                (end < (p->offset + p->mtd.size)))
                goto err_inv;
        }

    list_add(&new->list, &mtd_partitions);
    mutex_unlock(&mtd_partitions_mutex);

    add_mtd_device(&new->mtd);

    return ret;
err_inv:
    mutex_unlock(&mtd_partitions_mutex);
    free_partition(new);
    return -EINVAL;
}
EXPORT_SYMBOL_GPL(mtd_add_partition);

int mtd_del_partition(struct mtd_info *master, int partno)
{
    struct mtd_part *slave, *next;
    int ret = -EINVAL;

    mutex_lock(&mtd_partitions_mutex);
    list_for_each_entry_safe(slave, next, &mtd_partitions, list)
        if ((slave->master == master) &&
            (slave->mtd.index == partno)) {
            ret = del_mtd_device(&slave->mtd);
            if (ret < 0)
                break;

            list_del(&slave->list);
            free_partition(slave);
            break;
        }
    mutex_unlock(&mtd_partitions_mutex);

    return ret;
}
EXPORT_SYMBOL_GPL(mtd_del_partition);

/*
 * 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 = allocate_partition(master, parts + i, i, cur_offset);
        if (IS_ERR(slave))
            return PTR_ERR(slave);

        mutex_lock(&mtd_partitions_mutex);
        list_add(&slave->list, &mtd_partitions);
        mutex_unlock(&mtd_partitions_mutex);

        add_mtd_device(&slave->mtd);

        cur_offset = slave->offset + slave->mtd.size;
    }

    return 0;
}

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;
}

#define put_partition_parser(p) do { module_put((p)->owner); } while (0)

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);

/*
 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 * are changing this array!
 */
static const char *default_mtd_part_types[] = {
    "cmdlinepart",
    "ofpart",
    NULL
};

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

    if (!types)
        types = default_mtd_part_types;

    for ( ; ret <= 0 && *types; types++) {
        parser = get_partition_parser(*types);
        if (!parser && !request_module("%s", *types))
            parser = get_partition_parser(*types);
        if (!parser)
            continue;
        ret = (*parser->parse_fn)(master, pparts, data);
        put_partition_parser(parser);
        if (ret > 0) {
            printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
                   ret, parser->name, master->name);
            break;
        }
    }
    return ret;
}

int mtd_is_partition(const struct mtd_info *mtd)
{
    struct mtd_part *part;
    int ispart = 0;

    mutex_lock(&mtd_partitions_mutex);
    list_for_each_entry(part, &mtd_partitions, list)
        if (&part->mtd == mtd) {
            ispart = 1;
            break;
        }
    mutex_unlock(&mtd_partitions_mutex);

    return ispart;
}
EXPORT_SYMBOL_GPL(mtd_is_partition);

/* Returns the size of the entire flash chip */
uint64_t mtd_get_device_size(const struct mtd_info *mtd)
{
    if (!mtd_is_partition(mtd))
        return mtd->size;

    return PART(mtd)->master->size;
}
EXPORT_SYMBOL_GPL(mtd_get_device_size);