include/linux/mtd/ubi.h

   1 /*
   2  * Copyright (c) International Business Machines Corp., 2006
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  12  * the GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  *
  18  * Author: Artem Bityutskiy (Битюцкий Артём)
  19  */
  20
  21 #ifndef __LINUX_UBI_H__
  22 #define __LINUX_UBI_H__
  23
  24 #include <asm/ioctl.h>
  25 #include <linux/types.h>
  26 #include <mtd/ubi-user.h>
  27
  28 /*
  29  * enum ubi_open_mode - UBI volume open mode constants.
  30  *
  31  * UBI_READONLY: read-only mode
  32  * UBI_READWRITE: read-write mode
  33  * UBI_EXCLUSIVE: exclusive mode
  34  */
  35 enum {
  36         UBI_READONLY = 1,
  37         UBI_READWRITE,
  38         UBI_EXCLUSIVE
  39 };
  40
  41 /**
  42  * struct ubi_volume_info - UBI volume description data structure.
  43  * @vol_id: volume ID
  44  * @ubi_num: UBI device number this volume belongs to
  45  * @size: how many physical eraseblocks are reserved for this volume
  46  * @used_bytes: how many bytes of data this volume contains
  47  * @used_ebs: how many physical eraseblocks of this volume actually contain any
  48  *            data
  49  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
  50  * @corrupted: non-zero if the volume is corrupted (static volumes only)
  51  * @upd_marker: non-zero if the volume has update marker set
  52  * @alignment: volume alignment
  53  * @usable_leb_size: how many bytes are available in logical eraseblocks of
  54  *                   this volume
  55  * @name_len: volume name length
  56  * @name: volume name
  57  * @cdev: UBI volume character device major and minor numbers
  58  *
  59  * The @corrupted flag is only relevant to static volumes and is always zero
  60  * for dynamic ones. This is because UBI does not care about dynamic volume
  61  * data protection and only cares about protecting static volume data.
  62  *
  63  * The @upd_marker flag is set if the volume update operation was interrupted.
  64  * Before touching the volume data during the update operation, UBI first sets
  65  * the update marker flag for this volume. If the volume update operation was
  66  * further interrupted, the update marker indicates this. If the update marker
  67  * is set, the contents of the volume is certainly damaged and a new volume
  68  * update operation has to be started.
  69  *
  70  * To put it differently, @corrupted and @upd_marker fields have different
  71  * semantics:
  72  *     o the @corrupted flag means that this static volume is corrupted for some
  73  *       reasons, but not because an interrupted volume update
  74  *     o the @upd_marker field means that the volume is damaged because of an
  75  *       interrupted update operation.
  76  *
  77  * I.e., the @corrupted flag is never set if the @upd_marker flag is set.
  78  *
  79  * The @used_bytes and @used_ebs fields are only really needed for static
  80  * volumes and contain the number of bytes stored in this static volume and how
  81  * many eraseblock this data occupies. In case of dynamic volumes, the
  82  * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs
  83  * field is equivalent to @size.
  84  *
  85  * In general, logical eraseblock size is a property of the UBI device, not
  86  * of the UBI volume. Indeed, the logical eraseblock size depends on the
  87  * physical eraseblock size and on how much bytes UBI headers consume. But
  88  * because of the volume alignment (@alignment), the usable size of logical
  89  * eraseblocks if a volume may be less. The following equation is true:
  90  *      @usable_leb_size = LEB size - (LEB size mod @alignment),
  91  * where LEB size is the logical eraseblock size defined by the UBI device.
  92  *
  93  * The alignment is multiple to the minimal flash input/output unit size or %1
  94  * if all the available space is used.
  95  *
  96  * To put this differently, alignment may be considered is a way to change
  97  * volume logical eraseblock sizes.
  98  */
  99 struct ubi_volume_info {
 100         int ubi_num;
 101         int vol_id;
 102         int size;
 103         long long used_bytes;
 104         int used_ebs;
 105         int vol_type;
 106         int corrupted;
 107         int upd_marker;
 108         int alignment;
 109         int usable_leb_size;
 110         int name_len;
 111         const char *name;
 112         dev_t cdev;
 113 };
 114
 115 /**
 116  * struct ubi_device_info - UBI device description data structure.
 117  * @ubi_num: ubi device number
 118  * @leb_size: logical eraseblock size on this UBI device
 119  * @min_io_size: minimal I/O unit size
 120  * @ro_mode: if this device is in read-only mode
 121  * @cdev: UBI character device major and minor numbers
 122  *
 123  * Note, @leb_size is the logical eraseblock size offered by the UBI device.
 124  * Volumes of this UBI device may have smaller logical eraseblock size if their
 125  * alignment is not equivalent to %1.
 126  */
 127 struct ubi_device_info {
 128         int ubi_num;
 129         int leb_size;
 130         int min_io_size;
 131         int ro_mode;
 132         dev_t cdev;
 133 };
 134
 135 /* UBI descriptor given to users when they open UBI volumes */
 136 struct ubi_volume_desc;
 137
 138 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di);
 139 void ubi_get_volume_info(struct ubi_volume_desc *desc,
 140                          struct ubi_volume_info *vi);
 141 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);
 142 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
 143                                            int mode);
 144 void ubi_close_volume(struct ubi_volume_desc *desc);
 145 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
 146                  int len, int check);
 147 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
 148                   int offset, int len, int dtype);
 149 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
 150                    int len, int dtype);
 151 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);
 152 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);
 153 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);
 154 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
 155 int ubi_sync(int ubi_num);
 156
 157 /*
 158  * This function is the same as the 'ubi_leb_read()' function, but it does not
 159  * provide the checking capability.
 160  */
 161 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf,
 162                            int offset, int len)
 163 {
 164         return ubi_leb_read(desc, lnum, buf, offset, len, 0);
 165 }
 166
 167 /*
 168  * This function is the same as the 'ubi_leb_write()' functions, but it does
 169  * not have the data type argument.
 170  */
 171 static inline int ubi_write(struct ubi_volume_desc *desc, int lnum,
 172                             const void *buf, int offset, int len)
 173 {
 174         return ubi_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);
 175 }
 176
 177 /*
 178  * This function is the same as the 'ubi_leb_change()' functions, but it does
 179  * not have the data type argument.
 180  */
 181 static inline int ubi_change(struct ubi_volume_desc *desc, int lnum,
 182                                     const void *buf, int len)
 183 {
 184         return ubi_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);
 185 }
 186
 187 #endif /* !__LINUX_UBI_H__ */