// SPDX-License-Identifier: GPL-2.0+
/*
 * Simple MTD partitioning layer
 *
 * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
 * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
 * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
 *
 */

#ifndef __UBOOT__
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/kmod.h>
#endif

#include <common.h>
#include <malloc.h>
#include <linux/errno.h>
#include <linux/compat.h>
#include <ubi_uboot.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/err.h>
#include <linux/sizes.h>

#include "mtdcore.h"

#ifndef __UBOOT__
static DEFINE_MUTEX(mtd_partitions_mutex);
#else
DEFINE_MUTEX(mtd_partitions_mutex);
#endif

#ifdef __UBOOT__
/* from mm/util.c */

/**
 * kstrdup - allocate space for and copy an existing string
 * @s: the string to duplicate
 * @gfp: the GFP mask used in the kmalloc() call when allocating memory
 */
char *kstrdup(const char *s, gfp_t gfp)
{
        size_t len;
        char *buf;

        if (!s)
                return NULL;

        len = strlen(s) + 1;
        buf = kmalloc(len, gfp);
        if (buf)
                memcpy(buf, s, len);
        return buf;
}
#endif

#define MTD_SIZE_REMAINING              (~0LLU)
#define MTD_OFFSET_NOT_SPECIFIED        (~0LLU)

bool mtd_partitions_used(struct mtd_info *master)
{
        struct mtd_info *slave;

        list_for_each_entry(slave, &master->partitions, node) {
                if (slave->usecount)
                        return true;
        }

        return false;
}

/**
 * mtd_parse_partition - Parse @mtdparts partition definition, fill @partition
 *                       with it and update the @mtdparts string pointer.
 *
 * The partition name is allocated and must be freed by the caller.
 *
 * This function is widely inspired from part_parse (mtdparts.c).
 *
 * @mtdparts: String describing the partition with mtdparts command syntax
 * @partition: MTD partition structure to fill
 *
 * @return 0 on success, an error otherwise.
 */
static int mtd_parse_partition(const char **_mtdparts,
                               struct mtd_partition *partition)
{
        const char *mtdparts = *_mtdparts;
        const char *name = NULL;
        int name_len;
        char *buf;

        /* Ensure the partition structure is empty */
        memset(partition, 0, sizeof(struct mtd_partition));

        /* Fetch the partition size */
        if (*mtdparts == '-') {
                /* Assign all remaining space to this partition */
                partition->size = MTD_SIZE_REMAINING;
                mtdparts++;
        } else {
                partition->size = ustrtoull(mtdparts, (char **)&mtdparts, 0);
                if (partition->size < SZ_4K) {
                        printf("Minimum partition size 4kiB, %lldB requested\n",
                               partition->size);
                        return -EINVAL;
                }
        }

        /* Check for the offset */
        partition->offset = MTD_OFFSET_NOT_SPECIFIED;
        if (*mtdparts == '@') {
                mtdparts++;
                partition->offset = ustrtoull(mtdparts, (char **)&mtdparts, 0);
        }

        /* Now look for the name */
        if (*mtdparts == '(') {
                name = ++mtdparts;
                mtdparts = strchr(name, ')');
                if (!mtdparts) {
                        printf("No closing ')' found in partition name\n");
                        return -EINVAL;
                }
                name_len = mtdparts - name + 1;
                if ((name_len - 1) == 0) {
                        printf("Empty partition name\n");
                        return -EINVAL;
                }
                mtdparts++;
        } else {
                /* Name will be of the form size@offset */
                name_len = 22;
        }

        /* Check if the partition is read-only */
        if (strncmp(mtdparts, "ro", 2) == 0) {
                partition->mask_flags |= MTD_WRITEABLE;
                mtdparts += 2;
        }

        /* Check for a potential next partition definition */
        if (*mtdparts == ',') {
                if (partition->size == MTD_SIZE_REMAINING) {
                        printf("No partitions allowed after a fill-up\n");
                        return -EINVAL;
                }
                ++mtdparts;
        } else if ((*mtdparts == ';') || (*mtdparts == '\0')) {
                /* NOP */
        } else {
                printf("Unexpected character '%c' in mtdparts\n", *mtdparts);
                return -EINVAL;
        }

        /*
         * Allocate a buffer for the name and either copy the provided name or
         * auto-generate it with the form 'size@offset'.
         */
        buf = malloc(name_len);
        if (!buf)
                return -ENOMEM;

        if (name)
                strncpy(buf, name, name_len - 1);
        else
                snprintf(buf, name_len, "0x%08llx@0x%08llx",
                         partition->size, partition->offset);

        buf[name_len - 1] = '\0';
        partition->name = buf;

        *_mtdparts = mtdparts;

        return 0;
}

/**
 * mtd_parse_partitions - Create a partition array from an mtdparts definition
 *
 * Stateless function that takes a @parent MTD device, a string @_mtdparts
 * describing the partitions (with the "mtdparts" command syntax) and creates
 * the corresponding MTD partition structure array @_parts. Both the name and
 * the structure partition itself must be freed freed, the caller may use
 * @mtd_free_parsed_partitions() for this purpose.
 *
 * @parent: MTD device which contains the partitions
 * @_mtdparts: Pointer to a string describing the partitions with "mtdparts"
 *             command syntax.
 * @_parts: Allocated array containing the partitions, must be freed by the
 *          caller.
 * @_nparts: Size of @_parts array.
 *
 * @return 0 on success, an error otherwise.
 */
int mtd_parse_partitions(struct mtd_info *parent, const char **_mtdparts,
                         struct mtd_partition **_parts, int *_nparts)
{
        struct mtd_partition partition = {}, *parts;
        const char *mtdparts = *_mtdparts;
        int cur_off = 0, cur_sz = 0;
        int nparts = 0;
        int ret, idx;
        u64 sz;

        /* First, iterate over the partitions until we know their number */
        while (mtdparts[0] != '\0' && mtdparts[0] != ';') {
                ret = mtd_parse_partition(&mtdparts, &partition);
                if (ret)
                        return ret;

                free((char *)partition.name);
                nparts++;
        }

        /* Allocate an array of partitions to give back to the caller */
        parts = malloc(sizeof(*parts) * nparts);
        if (!parts) {
                printf("Not enough space to save partitions meta-data\n");
                return -ENOMEM;
        }

        /* Iterate again over each partition to save the data in our array */
        for (idx = 0; idx < nparts; idx++) {
                ret = mtd_parse_partition(_mtdparts, &parts[idx]);
                if (ret)
                        return ret;

                if (parts[idx].size == MTD_SIZE_REMAINING)
                        parts[idx].size = parent->size - cur_sz;
                cur_sz += parts[idx].size;

                sz = parts[idx].size;
                if (sz < parent->writesize || do_div(sz, parent->writesize)) {
                        printf("Partition size must be a multiple of %d\n",
                               parent->writesize);
                        return -EINVAL;
                }

                if (parts[idx].offset == MTD_OFFSET_NOT_SPECIFIED)
                        parts[idx].offset = cur_off;
                cur_off += parts[idx].size;

                parts[idx].ecclayout = parent->ecclayout;
        }

        /* Offset by one mtdparts to point to the next device if any */
        if (*_mtdparts[0] == ';')
                (*_mtdparts)++;

        *_parts = parts;
        *_nparts = nparts;

        return 0;
}

/**
 * mtd_free_parsed_partitions - Free dynamically allocated partitions
 *
 * Each successful call to @mtd_parse_partitions must be followed by a call to
 * @mtd_free_parsed_partitions to free any allocated array during the parsing
 * process.
 *
 * @parts: Array containing the partitions that will be freed.
 * @nparts: Size of @parts array.
 */
void mtd_free_parsed_partitions(struct mtd_partition *parts,
                                unsigned int nparts)
{
        int i;

        for (i = 0; i < nparts; i++)
                free((char *)parts[i].name);

        free(parts);
}

/*
 * 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_ecc_stats stats;
        int res;

        stats = mtd->parent->ecc_stats;
        res = mtd->parent->_read(mtd->parent, from + mtd->offset, len,
                                 retlen, buf);
        if (unlikely(mtd_is_eccerr(res)))
                mtd->ecc_stats.failed +=
                        mtd->parent->ecc_stats.failed - stats.failed;
        else
                mtd->ecc_stats.corrected +=
                        mtd->parent->ecc_stats.corrected - stats.corrected;
        return res;
}

#ifndef __UBOOT__
static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
                size_t *retlen, void **virt, resource_size_t *phys)
{
        return mtd->parent->_point(mtd->parent, from + mtd->offset, len,
                                   retlen, virt, phys);
}

static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
        return mtd->parent->_unpoint(mtd->parent, from + mtd->offset, len);
}
#endif

static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
                                            unsigned long len,
                                            unsigned long offset,
                                            unsigned long flags)
{
        offset += mtd->offset;
        return mtd->parent->_get_unmapped_area(mtd->parent, len, offset, flags);
}

static int part_read_oob(struct mtd_info *mtd, loff_t from,
                struct mtd_oob_ops *ops)
{
        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 = mtd->parent->_read_oob(mtd->parent, from + mtd->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)
{
        return mtd->parent->_read_user_prot_reg(mtd->parent, from, len,
                                                retlen, buf);
}

static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
                                   size_t *retlen, struct otp_info *buf)
{
        return mtd->parent->_get_user_prot_info(mtd->parent, 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)
{
        return mtd->parent->_read_fact_prot_reg(mtd->parent, from, len,
                                                retlen, buf);
}

static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
                                   size_t *retlen, struct otp_info *buf)
{
        return mtd->parent->_get_fact_prot_info(mtd->parent, len, retlen,
                                                buf);
}

static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
                size_t *retlen, const u_char *buf)
{
        return mtd->parent->_write(mtd->parent, to + mtd->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)
{
        return mtd->parent->_panic_write(mtd->parent, to + mtd->offset, len,
                                         retlen, buf);
}

static int part_write_oob(struct mtd_info *mtd, loff_t to,
                struct mtd_oob_ops *ops)
{
        if (to >= mtd->size)
                return -EINVAL;
        if (ops->datbuf && to + ops->len > mtd->size)
                return -EINVAL;
        return mtd->parent->_write_oob(mtd->parent, to + mtd->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)
{
        return mtd->parent->_write_user_prot_reg(mtd->parent, from, len,
                                                 retlen, buf);
}

static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
                size_t len)
{
        return mtd->parent->_lock_user_prot_reg(mtd->parent, from, len);
}

#ifndef __UBOOT__
static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
                unsigned long count, loff_t to, size_t *retlen)
{
        return mtd->parent->_writev(mtd->parent, vecs, count,
                                    to + mtd->offset, retlen);
}
#endif

static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
{
        int ret;

        instr->addr += mtd->offset;
        ret = mtd->parent->_erase(mtd->parent, instr);
        if (ret) {
                if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
                        instr->fail_addr -= mtd->offset;
                instr->addr -= mtd->offset;
        }
        return ret;
}

void mtd_erase_callback(struct erase_info *instr)
{
        if (instr->mtd->_erase == part_erase) {
                if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
                        instr->fail_addr -= instr->mtd->offset;
                instr->addr -= instr->mtd->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)
{
        return mtd->parent->_lock(mtd->parent, ofs + mtd->offset, len);
}

static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
        return mtd->parent->_unlock(mtd->parent, ofs + mtd->offset, len);
}

static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
        return mtd->parent->_is_locked(mtd->parent, ofs + mtd->offset, len);
}

static void part_sync(struct mtd_info *mtd)
{
        mtd->parent->_sync(mtd->parent);
}

#ifndef __UBOOT__
static int part_suspend(struct mtd_info *mtd)
{
        return mtd->parent->_suspend(mtd->parent);
}

static void part_resume(struct mtd_info *mtd)
{
        mtd->parent->_resume(mtd->parent);
}
#endif

static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
{
        ofs += mtd->offset;
        return mtd->parent->_block_isreserved(mtd->parent, ofs);
}

static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
{
        ofs += mtd->offset;
        return mtd->parent->_block_isbad(mtd->parent, ofs);
}

static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
        int res;

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

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

/*
 * This function unregisters and destroy all slave MTD objects which are
 * attached to the given master MTD object, recursively.
 */
static int do_del_mtd_partitions(struct mtd_info *master)
{
        struct mtd_info *slave, *next;
        int ret, err = 0;

        list_for_each_entry_safe(slave, next, &master->partitions, node) {
                if (mtd_has_partitions(slave))
                        del_mtd_partitions(slave);

                debug("Deleting %s MTD partition\n", slave->name);
                ret = del_mtd_device(slave);
                if (ret < 0) {
                        printf("Error when deleting partition \"%s\" (%d)\n",
                               slave->name, ret);
                        err = ret;
                        continue;
                }

                list_del(&slave->node);
                free_partition(slave);
        }

        return err;
}

int del_mtd_partitions(struct mtd_info *master)
{
        int ret;

        debug("Deleting MTD partitions on \"%s\":\n", master->name);

        mutex_lock(&mtd_partitions_mutex);
        ret = do_del_mtd_partitions(master);
        mutex_unlock(&mtd_partitions_mutex);

        return ret;
}

static struct mtd_info *allocate_partition(struct mtd_info *master,
                                           const struct mtd_partition *part,
                                           int partno, uint64_t cur_offset)
{
        struct mtd_info *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->type = master->type;
        slave->flags = master->flags & ~part->mask_flags;
        slave->size = part->size;
        slave->writesize = master->writesize;
        slave->writebufsize = master->writebufsize;
        slave->oobsize = master->oobsize;
        slave->oobavail = master->oobavail;
        slave->subpage_sft = master->subpage_sft;

        slave->name = name;
        slave->owner = master->owner;
#ifndef __UBOOT__
        slave->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->dev.parent = master->dev.parent;
#endif

        if (master->_read)
                slave->_read = part_read;
        if (master->_write)
                slave->_write = part_write;

        if (master->_panic_write)
                slave->_panic_write = part_panic_write;

#ifndef __UBOOT__
        if (master->_point && master->_unpoint) {
                slave->_point = part_point;
                slave->_unpoint = part_unpoint;
        }
#endif

        if (master->_get_unmapped_area)
                slave->_get_unmapped_area = part_get_unmapped_area;
        if (master->_read_oob)
                slave->_read_oob = part_read_oob;
        if (master->_write_oob)
                slave->_write_oob = part_write_oob;
        if (master->_read_user_prot_reg)
                slave->_read_user_prot_reg = part_read_user_prot_reg;
        if (master->_read_fact_prot_reg)
                slave->_read_fact_prot_reg = part_read_fact_prot_reg;
        if (master->_write_user_prot_reg)
                slave->_write_user_prot_reg = part_write_user_prot_reg;
        if (master->_lock_user_prot_reg)
                slave->_lock_user_prot_reg = part_lock_user_prot_reg;
        if (master->_get_user_prot_info)
                slave->_get_user_prot_info = part_get_user_prot_info;
        if (master->_get_fact_prot_info)
                slave->_get_fact_prot_info = part_get_fact_prot_info;
        if (master->_sync)
                slave->_sync = part_sync;
#ifndef __UBOOT__
        if (!partno && !master->dev.class && master->_suspend &&
            master->_resume) {
                slave->_suspend = part_suspend;
                slave->_resume = part_resume;
        }
        if (master->_writev)
                slave->_writev = part_writev;
#endif
        if (master->_lock)
                slave->_lock = part_lock;
        if (master->_unlock)
                slave->_unlock = part_unlock;
        if (master->_is_locked)
                slave->_is_locked = part_is_locked;
        if (master->_block_isreserved)
                slave->_block_isreserved = part_block_isreserved;
        if (master->_block_isbad)
                slave->_block_isbad = part_block_isbad;
        if (master->_block_markbad)
                slave->_block_markbad = part_block_markbad;
        slave->_erase = part_erase;
        slave->parent = master;
        slave->offset = part->offset;
        INIT_LIST_HEAD(&slave->partitions);
        INIT_LIST_HEAD(&slave->node);

        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;
                        debug("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->size) {
                        slave->size = master->size - slave->offset
                                                        - slave->size;
                } else {
                        debug("mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
                                part->name, master->size - slave->offset,
                                slave->size);
                        /* register to preserve ordering */
                        goto out_register;
                }
        }
        if (slave->size == MTDPART_SIZ_FULL)
                slave->size = master->size - slave->offset;

        debug("0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
                (unsigned long long)(slave->offset + slave->size), slave->name);

        /* let's do some sanity checks */
        if (slave->offset >= master->size) {
                /* let's register it anyway to preserve ordering */
                slave->offset = 0;
                slave->size = 0;
                printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
                        part->name);
                goto out_register;
        }
        if (slave->offset + slave->size > master->size) {
                slave->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, slave->size);
        }
        if (master->numeraseregions > 1) {
                /* Deal with variable erase size stuff */
                int i, max = master->numeraseregions;
                u64 end = slave->offset + slave->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->erasesize < regions[i].erasesize)
                                slave->erasesize = regions[i].erasesize;
                }
                WARN_ON(slave->erasesize == 0);
        } else {
                /* Single erase size */
                slave->erasesize = master->erasesize;
        }

        if ((slave->flags & MTD_WRITEABLE) &&
            mtd_mod_by_eb(slave->offset, slave)) {
                /* 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->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->flags & MTD_WRITEABLE) &&
            mtd_mod_by_eb(slave->size, slave)) {
                slave->flags &= ~MTD_WRITEABLE;
                printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
                        part->name);
        }

        slave->ecclayout = master->ecclayout;
        slave->ecc_step_size = master->ecc_step_size;
        slave->ecc_strength = master->ecc_strength;
        slave->bitflip_threshold = master->bitflip_threshold;

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

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

out_register:
        return slave;
}

#ifndef __UBOOT__
int mtd_add_partition(struct mtd_info *master, const char *name,
                      long long offset, long long length)
{
        struct mtd_partition part;
        struct mtd_info *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, &master->partitions, node) {
                if (start >= p->offset &&
                    (start < (p->offset + p->size)))
                        goto err_inv;

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

        list_add_tail(&new->node, &master->partitions);
        mutex_unlock(&mtd_partitions_mutex);

        add_mtd_device(new);

        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_info *slave, *next;
        int ret = -EINVAL;

        mutex_lock(&mtd_partitions_mutex);
        list_for_each_entry_safe(slave, next, &master->partitions, node)
                if (slave->index == partno) {
                        ret = del_mtd_device(slave);
                        if (ret < 0)
                                break;

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

        return ret;
}
EXPORT_SYMBOL_GPL(mtd_del_partition);
#endif

/*
 * 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_info *slave;
        uint64_t cur_offset = 0;
        int i;

        debug("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_tail(&slave->node, &master->partitions);
                mutex_unlock(&mtd_partitions_mutex);

                add_mtd_device(slave);

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

        return 0;
}

#ifndef __UBOOT__
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)

void register_mtd_parser(struct mtd_part_parser *p)
{
        spin_lock(&part_parser_lock);
        list_add(&p->list, &part_parsers);
        spin_unlock(&part_parser_lock);
}
EXPORT_SYMBOL_GPL(register_mtd_parser);

void deregister_mtd_parser(struct mtd_part_parser *p)
{
        spin_lock(&part_parser_lock);
        list_del(&p->list);
        spin_unlock(&part_parser_lock);
}
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 * const default_mtd_part_types[] = {
        "cmdlinepart",
        "ofpart",
        NULL
};

/**
 * parse_mtd_partitions - parse MTD partitions
 * @master: the master partition (describes whole MTD device)
 * @types: names of partition parsers to try or %NULL
 * @pparts: array of partitions found is returned here
 * @data: MTD partition parser-specific data
 *
 * This function tries to find partition on MTD device @master. It uses MTD
 * partition parsers, specified in @types. However, if @types is %NULL, then
 * the default list of parsers is used. The default list contains only the
 * "cmdlinepart" and "ofpart" parsers ATM.
 * Note: If there are more then one parser in @types, the kernel only takes the
 * partitions parsed out by the first parser.
 *
 * This function may return:
 * o a negative error code in case of failure
 * o zero if no partitions were found
 * o a positive number of found partitions, in which case on exit @pparts will
 *   point to an array containing this number of &struct mtd_info objects.
 */
int parse_mtd_partitions(struct mtd_info *master, const char *const *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;
}
#endif

/* 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->parent->size;

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