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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)

 */

#ifndef __LINUX_UBI_H__

#define __LINUX_UBI_H__

#include <asm/ioctl.h>

#include <linux/types.h>

#include <mtd/ubi-user.h>

/*

 * UBI data type hint constants.

 *

 * UBI_LONGTERM: long-term data

 * UBI_SHORTTERM: short-term data

 * UBI_UNKNOWN: data persistence is unknown

 *

 * These constants are used when data is written to UBI volumes in order to

 * help the UBI wear-leveling unit to find more appropriate physical

 * eraseblocks.

 */

enum {

        UBI_LONGTERM = 1,

        UBI_SHORTTERM,

        UBI_UNKNOWN

};

/*

 * enum ubi_open_mode - UBI volume open mode constants.

 *

 * UBI_READONLY: read-only mode

 * UBI_READWRITE: read-write mode

 * UBI_EXCLUSIVE: exclusive mode

 */

enum {

        UBI_READONLY = 1,

        UBI_READWRITE,

        UBI_EXCLUSIVE

};

/**

 * struct ubi_volume_info - UBI volume description data structure.

 * @vol_id: volume ID

 * @ubi_num: UBI device number this volume belongs to

 * @size: how many physical eraseblocks are reserved for this volume

 * @used_bytes: how many bytes of data this volume contains

 * @used_ebs: how many physical eraseblocks of this volume actually contain any

 * data

 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)

 * @corrupted: non-zero if the volume is corrupted (static volumes only)

 * @upd_marker: non-zero if the volume has update marker set

 * @alignment: volume alignment

 * @usable_leb_size: how many bytes are available in logical eraseblocks of

 * this volume

 * @name_len: volume name length

 * @name: volume name

 * @cdev: UBI volume character device major and minor numbers

 *

 * The @corrupted flag is only relevant to static volumes and is always zero

 * for dynamic ones. This is because UBI does not care about dynamic volume

 * data protection and only cares about protecting static volume data.

 *

 * The @upd_marker flag is set if the volume update operation was interrupted.

 * Before touching the volume data during the update operation, UBI first sets

 * the update marker flag for this volume. If the volume update operation was

 * further interrupted, the update marker indicates this. If the update marker

 * is set, the contents of the volume is certainly damaged and a new volume

 * update operation has to be started.

 *

 * To put it differently, @corrupted and @upd_marker fields have different

 * semantics:

 *     o the @corrupted flag means that this static volume is corrupted for some

 *       reasons, but not because an interrupted volume update

 *     o the @upd_marker field means that the volume is damaged because of an

 *       interrupted update operation.

 *

 * I.e., the @corrupted flag is never set if the @upd_marker flag is set.

 *

 * The @used_bytes and @used_ebs fields are only really needed for static

 * volumes and contain the number of bytes stored in this static volume and how

 * many eraseblock this data occupies. In case of dynamic volumes, the

 * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs

 * field is equivalent to @size.

 *

 * In general, logical eraseblock size is a property of the UBI device, not

 * of the UBI volume. Indeed, the logical eraseblock size depends on the

 * physical eraseblock size and on how much bytes UBI headers consume. But

 * because of the volume alignment (@alignment), the usable size of logical

 * eraseblocks if a volume may be less. The following equation is true:

 *      @usable_leb_size = LEB size - (LEB size mod @alignment),

 * where LEB size is the logical eraseblock size defined by the UBI device.

 *

 * The alignment is multiple to the minimal flash input/output unit size or %1

 * if all the available space is used.

 *

 * To put this differently, alignment may be considered is a way to change

 * volume logical eraseblock sizes.

 */

struct ubi_volume_info {

        int ubi_num;

        int vol_id;

        int size;

        long long used_bytes;

        int used_ebs;

        int vol_type;

        int corrupted;

        int upd_marker;

        int alignment;

        int usable_leb_size;

        int name_len;

        const char *name;

        dev_t cdev;

};

/**

 * struct ubi_device_info - UBI device description data structure.

 * @ubi_num: ubi device number

 * @leb_size: logical eraseblock size on this UBI device

 * @min_io_size: minimal I/O unit size

 * @ro_mode: if this device is in read-only mode

 * @cdev: UBI character device major and minor numbers

 *

 * Note, @leb_size is the logical eraseblock size offered by the UBI device.

 * Volumes of this UBI device may have smaller logical eraseblock size if their

 * alignment is not equivalent to %1.

 */

struct ubi_device_info {

        int ubi_num;

        int leb_size;

        int min_io_size;

        int ro_mode;

        dev_t cdev;

};

/* UBI descriptor given to users when they open UBI volumes */

struct ubi_volume_desc;

int ubi_get_device_info(int ubi_num, struct ubi_device_info *di);

void ubi_get_volume_info(struct ubi_volume_desc *desc,

                         struct ubi_volume_info *vi);

struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);

struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,

                                           int mode);

void ubi_close_volume(struct ubi_volume_desc *desc);

int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,

                 int len, int check);

int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,

                  int offset, int len, int dtype);

int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,

                   int len, int dtype);

int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);

int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);

int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);

/*

 * This function is the same as the 'ubi_leb_read()' function, but it does not

 * provide the checking capability.

 */

static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf,

                           int offset, int len)

{

        return ubi_leb_read(desc, lnum, buf, offset, len, 0);

}

/*

 * This function is the same as the 'ubi_leb_write()' functions, but it does

 * not have the data type argument.

 */

static inline int ubi_write(struct ubi_volume_desc *desc, int lnum,

                            const void *buf, int offset, int len)

{

        return ubi_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);

}

/*

 * This function is the same as the 'ubi_leb_change()' functions, but it does

 * not have the data type argument.

 */

static inline int ubi_change(struct ubi_volume_desc *desc, int lnum,

                                    const void *buf, int len)

{

        return ubi_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);

}

#endif /* !__LINUX_UBI_H__ */