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 <linux/ioctl.h> 25 #include <linux/types.h> 26 #include <mtd/ubi-user.h> 27 28 /* All voumes/LEBs */ 29 #define UBI_ALL -1 30 31 /* 32 * enum ubi_open_mode - UBI volume open mode constants. 33 * 34 * UBI_READONLY: read-only mode 35 * UBI_READWRITE: read-write mode 36 * UBI_EXCLUSIVE: exclusive mode 37 * UBI_METAONLY: modify only the volume meta-data, 38 * i.e. the data stored in the volume table, but not in any of volume LEBs. 39 */ 40 enum { 41 UBI_READONLY = 1, 42 UBI_READWRITE, 43 UBI_EXCLUSIVE, 44 UBI_METAONLY 45 }; 46 47 /** 48 * struct ubi_volume_info - UBI volume description data structure. 49 * @vol_id: volume ID 50 * @ubi_num: UBI device number this volume belongs to 51 * @size: how many physical eraseblocks are reserved for this volume 52 * @used_bytes: how many bytes of data this volume contains 53 * @used_ebs: how many physical eraseblocks of this volume actually contain any 54 * data 55 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 56 * @corrupted: non-zero if the volume is corrupted (static volumes only) 57 * @upd_marker: non-zero if the volume has update marker set 58 * @alignment: volume alignment 59 * @usable_leb_size: how many bytes are available in logical eraseblocks of 60 * this volume 61 * @name_len: volume name length 62 * @name: volume name 63 * @cdev: UBI volume character device major and minor numbers 64 * 65 * The @corrupted flag is only relevant to static volumes and is always zero 66 * for dynamic ones. This is because UBI does not care about dynamic volume 67 * data protection and only cares about protecting static volume data. 68 * 69 * The @upd_marker flag is set if the volume update operation was interrupted. 70 * Before touching the volume data during the update operation, UBI first sets 71 * the update marker flag for this volume. If the volume update operation was 72 * further interrupted, the update marker indicates this. If the update marker 73 * is set, the contents of the volume is certainly damaged and a new volume 74 * update operation has to be started. 75 * 76 * To put it differently, @corrupted and @upd_marker fields have different 77 * semantics: 78 * o the @corrupted flag means that this static volume is corrupted for some 79 * reasons, but not because an interrupted volume update 80 * o the @upd_marker field means that the volume is damaged because of an 81 * interrupted update operation. 82 * 83 * I.e., the @corrupted flag is never set if the @upd_marker flag is set. 84 * 85 * The @used_bytes and @used_ebs fields are only really needed for static 86 * volumes and contain the number of bytes stored in this static volume and how 87 * many eraseblock this data occupies. In case of dynamic volumes, the 88 * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs 89 * field is equivalent to @size. 90 * 91 * In general, logical eraseblock size is a property of the UBI device, not 92 * of the UBI volume. Indeed, the logical eraseblock size depends on the 93 * physical eraseblock size and on how much bytes UBI headers consume. But 94 * because of the volume alignment (@alignment), the usable size of logical 95 * eraseblocks if a volume may be less. The following equation is true: 96 * @usable_leb_size = LEB size - (LEB size mod @alignment), 97 * where LEB size is the logical eraseblock size defined by the UBI device. 98 * 99 * The alignment is multiple to the minimal flash input/output unit size or %1 100 * if all the available space is used. 101 * 102 * To put this differently, alignment may be considered is a way to change 103 * volume logical eraseblock sizes. 104 */ 105 struct ubi_volume_info { 106 int ubi_num; 107 int vol_id; 108 int size; 109 long long used_bytes; 110 int used_ebs; 111 int vol_type; 112 int corrupted; 113 int upd_marker; 114 int alignment; 115 int usable_leb_size; 116 int name_len; 117 const char *name; 118 dev_t cdev; 119 }; 120 121 /** 122 * struct ubi_device_info - UBI device description data structure. 123 * @ubi_num: ubi device number 124 * @leb_size: logical eraseblock size on this UBI device 125 * @leb_start: starting offset of logical eraseblocks within physical 126 * eraseblocks 127 * @min_io_size: minimal I/O unit size 128 * @max_write_size: maximum amount of bytes the underlying flash can write at a 129 * time (MTD write buffer size) 130 * @ro_mode: if this device is in read-only mode 131 * @cdev: UBI character device major and minor numbers 132 * 133 * Note, @leb_size is the logical eraseblock size offered by the UBI device. 134 * Volumes of this UBI device may have smaller logical eraseblock size if their 135 * alignment is not equivalent to %1. 136 * 137 * The @max_write_size field describes flash write maximum write unit. For 138 * example, NOR flash allows for changing individual bytes, so @min_io_size is 139 * %1. However, it does not mean than NOR flash has to write data byte-by-byte. 140 * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when 141 * writing large chunks of data, they write 64-bytes at a time. Obviously, this 142 * improves write throughput. 143 * 144 * Also, the MTD device may have N interleaved (striped) flash chips 145 * underneath, in which case @min_io_size can be physical min. I/O size of 146 * single flash chip, while @max_write_size can be N * @min_io_size. 147 * 148 * The @max_write_size field is always greater or equivalent to @min_io_size. 149 * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In 150 * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND 151 * page size. 152 */ 153 struct ubi_device_info { 154 int ubi_num; 155 int leb_size; 156 int leb_start; 157 int min_io_size; 158 int max_write_size; 159 int ro_mode; 160 dev_t cdev; 161 }; 162 163 /* 164 * Volume notification types. 165 * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a 166 * volume was created) 167 * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached 168 * or a volume was removed) 169 * @UBI_VOLUME_RESIZED: a volume has been re-sized 170 * @UBI_VOLUME_RENAMED: a volume has been re-named 171 * @UBI_VOLUME_UPDATED: data has been written to a volume 172 * 173 * These constants define which type of event has happened when a volume 174 * notification function is invoked. 175 */ 176 enum { 177 UBI_VOLUME_ADDED, 178 UBI_VOLUME_REMOVED, 179 UBI_VOLUME_RESIZED, 180 UBI_VOLUME_RENAMED, 181 UBI_VOLUME_UPDATED, 182 }; 183 184 /* 185 * struct ubi_notification - UBI notification description structure. 186 * @di: UBI device description object 187 * @vi: UBI volume description object 188 * 189 * UBI notifiers are called with a pointer to an object of this type. The 190 * object describes the notification. Namely, it provides a description of the 191 * UBI device and UBI volume the notification informs about. 192 */ 193 struct ubi_notification { 194 struct ubi_device_info di; 195 struct ubi_volume_info vi; 196 }; 197 198 /* UBI descriptor given to users when they open UBI volumes */ 199 struct ubi_volume_desc; 200 201 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di); 202 void ubi_get_volume_info(struct ubi_volume_desc *desc, 203 struct ubi_volume_info *vi); 204 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode); 205 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, 206 int mode); 207 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode); 208 209 int ubi_register_volume_notifier(struct notifier_block *nb, 210 int ignore_existing); 211 int ubi_unregister_volume_notifier(struct notifier_block *nb); 212 213 void ubi_close_volume(struct ubi_volume_desc *desc); 214 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, 215 int len, int check); 216 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, 217 int offset, int len); 218 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, 219 int len); 220 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum); 221 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum); 222 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum); 223 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum); 224 int ubi_sync(int ubi_num); 225 int ubi_flush(int ubi_num, int vol_id, int lnum); 226 227 /* 228 * This function is the same as the 'ubi_leb_read()' function, but it does not 229 * provide the checking capability. 230 */ 231 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf, 232 int offset, int len) 233 { 234 return ubi_leb_read(desc, lnum, buf, offset, len, 0); 235 } 236 #endif /* !__LINUX_UBI_H__ */ 237