misc.c

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/*
 * Copyright (c) International Business Machines Corp., 2006
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Author: Artem Bityutskiy (Битюцкий Артём)
 */

/* Here we keep miscellaneous functions which are used all over the UBI code */

#include "ubi.h"

int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
              int length)
{
    int i;

    ubi_assert(!(length & (ubi->min_io_size - 1)));

    for (i = length - 1; i >= 0; i--)
        if (((const uint8_t *)buf)[i] != 0xFF)
            break;

    /* The resulting length must be aligned to the minimum flash I/O size */
    length = ALIGN(i + 1, ubi->min_io_size);
    return length;
}

int ubi_check_volume(struct ubi_device *ubi, int vol_id)
{
    void *buf;
    int err = 0, i;
    struct ubi_volume *vol = ubi->volumes[vol_id];

    if (vol->vol_type != UBI_STATIC_VOLUME)
        return 0;

    buf = vmalloc(vol->usable_leb_size);
    if (!buf)
        return -ENOMEM;

    for (i = 0; i < vol->used_ebs; i++) {
        int size;

        if (i == vol->used_ebs - 1)
            size = vol->last_eb_bytes;
        else
            size = vol->usable_leb_size;

        err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
        if (err) {
            if (mtd_is_eccerr(err))
                err = 1;
            break;
        }
    }

    vfree(buf);
    return err;
}

void ubi_update_reserved(struct ubi_device *ubi)
{
    int need = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;

    if (need <= 0 || ubi->avail_pebs == 0)
        return;

    need = min_t(int, need, ubi->avail_pebs);
    ubi->avail_pebs -= need;
    ubi->rsvd_pebs += need;
    ubi->beb_rsvd_pebs += need;
    ubi_msg("reserved more %d PEBs for bad PEB handling", need);
}

void ubi_calculate_reserved(struct ubi_device *ubi)
{
    /*
     * Calculate the actual number of PEBs currently needed to be reserved
     * for future bad eraseblock handling.
     */
    ubi->beb_rsvd_level = ubi->bad_peb_limit - ubi->bad_peb_count;
    if (ubi->beb_rsvd_level < 0) {
        ubi->beb_rsvd_level = 0;
        ubi_warn("number of bad PEBs (%d) is above the expected limit (%d), not reserving any PEBs for bad PEB handling, will use available PEBs (if any)",
             ubi->bad_peb_count, ubi->bad_peb_limit);
    }
}

int ubi_check_pattern(const void *buf, uint8_t patt, int size)
{
    int i;

    for (i = 0; i < size; i++)
        if (((const uint8_t *)buf)[i] != patt)
            return 0;
    return 1;
}