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 /* 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 * @leb_start: starting offset of logical eraseblocks within physical 120 * eraseblocks 121 * @min_io_size: minimal I/O unit size 122 * @max_write_size: maximum amount of bytes the underlying flash can write at a 123 * time (MTD write buffer size) 124 * @ro_mode: if this device is in read-only mode 125 * @cdev: UBI character device major and minor numbers 126 * 127 * Note, @leb_size is the logical eraseblock size offered by the UBI device. 128 * Volumes of this UBI device may have smaller logical eraseblock size if their 129 * alignment is not equivalent to %1. 130 * 131 * The @max_write_size field describes flash write maximum write unit. For 132 * example, NOR flash allows for changing individual bytes, so @min_io_size is 133 * %1. However, it does not mean than NOR flash has to write data byte-by-byte. 134 * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when 135 * writing large chunks of data, they write 64-bytes at a time. Obviously, this 136 * improves write throughput. 137 * 138 * Also, the MTD device may have N interleaved (striped) flash chips 139 * underneath, in which case @min_io_size can be physical min. I/O size of 140 * single flash chip, while @max_write_size can be N * @min_io_size. 141 * 142 * The @max_write_size field is always greater or equivalent to @min_io_size. 143 * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In 144 * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND 145 * page size. 146 */ 147 struct ubi_device_info { 148 int ubi_num; 149 int leb_size; 150 int leb_start; 151 int min_io_size; 152 int max_write_size; 153 int ro_mode; 154 dev_t cdev; 155 }; 156 157 /* 158 * Volume notification types. 159 * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a 160 * volume was created) 161 * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached 162 * or a volume was removed) 163 * @UBI_VOLUME_RESIZED: a volume has been re-sized 164 * @UBI_VOLUME_RENAMED: a volume has been re-named 165 * @UBI_VOLUME_UPDATED: data has been written to a volume 166 * 167 * These constants define which type of event has happened when a volume 168 * notification function is invoked. 169 */ 170 enum { 171 UBI_VOLUME_ADDED, 172 UBI_VOLUME_REMOVED, 173 UBI_VOLUME_RESIZED, 174 UBI_VOLUME_RENAMED, 175 UBI_VOLUME_UPDATED, 176 }; 177 178 /* 179 * struct ubi_notification - UBI notification description structure. 180 * @di: UBI device description object 181 * @vi: UBI volume description object 182 * 183 * UBI notifiers are called with a pointer to an object of this type. The 184 * object describes the notification. Namely, it provides a description of the 185 * UBI device and UBI volume the notification informs about. 186 */ 187 struct ubi_notification { 188 struct ubi_device_info di; 189 struct ubi_volume_info vi; 190 }; 191 192 /* UBI descriptor given to users when they open UBI volumes */ 193 struct ubi_volume_desc; 194 195 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di); 196 void ubi_get_volume_info(struct ubi_volume_desc *desc, 197 struct ubi_volume_info *vi); 198 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode); 199 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, 200 int mode); 201 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode); 202 203 int ubi_register_volume_notifier(struct notifier_block *nb, 204 int ignore_existing); 205 int ubi_unregister_volume_notifier(struct notifier_block *nb); 206 207 void ubi_close_volume(struct ubi_volume_desc *desc); 208 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, 209 int len, int check); 210 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, 211 int offset, int len, int dtype); 212 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, 213 int len, int dtype); 214 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum); 215 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum); 216 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype); 217 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum); 218 int ubi_sync(int ubi_num); 219 220 /* 221 * This function is the same as the 'ubi_leb_read()' function, but it does not 222 * provide the checking capability. 223 */ 224 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf, 225 int offset, int len) 226 { 227 return ubi_leb_read(desc, lnum, buf, offset, len, 0); 228 } 229 230 /* 231 * This function is the same as the 'ubi_leb_write()' functions, but it does 232 * not have the data type argument. 233 */ 234 static inline int ubi_write(struct ubi_volume_desc *desc, int lnum, 235 const void *buf, int offset, int len) 236 { 237 return ubi_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN); 238 } 239 240 /* 241 * This function is the same as the 'ubi_leb_change()' functions, but it does 242 * not have the data type argument. 243 */ 244 static inline int ubi_change(struct ubi_volume_desc *desc, int lnum, 245 const void *buf, int len) 246 { 247 return ubi_leb_change(desc, lnum, buf, len, UBI_UNKNOWN); 248 } 249 250 #endif /* !__LINUX_UBI_H__ */ 251