Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * 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"

/**

 * calc_data_len - calculate how much real data is stored in a buffer.

 * @ubi: UBI device description object

 * @buf: a buffer with the contents of the physical eraseblock

 * @length: the buffer length

 *

 * This function calculates how much "real data" is stored in @buf and returnes

 * the length. Continuous 0xFF bytes at the end of the buffer are not

 * considered as "real data".

 */

int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,

                      int length)

{

        int i;

        ubi_assert(length % ubi->min_io_size == 0);

        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;

}

/**

 * ubi_check_volume - check the contents of a static volume.

 * @ubi: UBI device description object

 * @vol_id: ID of the volume to check

 *

 * This function checks if static volume @vol_id is corrupted by fully reading

 * it and checking data CRC. This function returns %0 if the volume is not

 * corrupted, %1 if it is corrupted and a negative error code in case of

 * failure. Dynamic volumes are not checked and zero is returned immediately.

 */

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_id, i, buf, 0, size, 1);

                if (err) {

                        if (err == -EBADMSG)

                                err = 1;

                        break;

                }

        }

        vfree(buf);

        return err;

}

/**

 * ubi_calculate_rsvd_pool - calculate how many PEBs must be reserved for bad

 * eraseblock handling.

 * @ubi: UBI device description object

 */

void ubi_calculate_reserved(struct ubi_device *ubi)

{

        ubi->beb_rsvd_level = ubi->good_peb_count/100;

        ubi->beb_rsvd_level *= CONFIG_MTD_UBI_BEB_RESERVE;

        if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS)

                ubi->beb_rsvd_level = MIN_RESEVED_PEBS;

}