Viewing file:  ubi.h (7.1 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* 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__ */
|