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 <linux/scatterlist.h> 27 #include <mtd/ubi-user.h> 28 29 /* All voumes/LEBs */ 30 #define UBI_ALL -1 31 32 /* 33 * Maximum number of scatter gather list entries, 34 * we use only 64 to have a lower memory foot print. 35 */ 36 #define UBI_MAX_SG_COUNT 64 37 38 /* 39 * enum ubi_open_mode - UBI volume open mode constants. 40 * 41 * UBI_READONLY: read-only mode 42 * UBI_READWRITE: read-write mode 43 * UBI_EXCLUSIVE: exclusive mode 44 * UBI_METAONLY: modify only the volume meta-data, 45 * i.e. the data stored in the volume table, but not in any of volume LEBs. 46 */ 47 enum { 48 UBI_READONLY = 1, 49 UBI_READWRITE, 50 UBI_EXCLUSIVE, 51 UBI_METAONLY 52 }; 53 54 /** 55 * struct ubi_volume_info - UBI volume description data structure. 56 * @vol_id: volume ID 57 * @ubi_num: UBI device number this volume belongs to 58 * @size: how many physical eraseblocks are reserved for this volume 59 * @used_bytes: how many bytes of data this volume contains 60 * @used_ebs: how many physical eraseblocks of this volume actually contain any 61 * data 62 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 63 * @corrupted: non-zero if the volume is corrupted (static volumes only) 64 * @upd_marker: non-zero if the volume has update marker set 65 * @alignment: volume alignment 66 * @usable_leb_size: how many bytes are available in logical eraseblocks of 67 * this volume 68 * @name_len: volume name length 69 * @name: volume name 70 * @cdev: UBI volume character device major and minor numbers 71 * 72 * The @corrupted flag is only relevant to static volumes and is always zero 73 * for dynamic ones. This is because UBI does not care about dynamic volume 74 * data protection and only cares about protecting static volume data. 75 * 76 * The @upd_marker flag is set if the volume update operation was interrupted. 77 * Before touching the volume data during the update operation, UBI first sets 78 * the update marker flag for this volume. If the volume update operation was 79 * further interrupted, the update marker indicates this. If the update marker 80 * is set, the contents of the volume is certainly damaged and a new volume 81 * update operation has to be started. 82 * 83 * To put it differently, @corrupted and @upd_marker fields have different 84 * semantics: 85 * o the @corrupted flag means that this static volume is corrupted for some 86 * reasons, but not because an interrupted volume update 87 * o the @upd_marker field means that the volume is damaged because of an 88 * interrupted update operation. 89 * 90 * I.e., the @corrupted flag is never set if the @upd_marker flag is set. 91 * 92 * The @used_bytes and @used_ebs fields are only really needed for static 93 * volumes and contain the number of bytes stored in this static volume and how 94 * many eraseblock this data occupies. In case of dynamic volumes, the 95 * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs 96 * field is equivalent to @size. 97 * 98 * In general, logical eraseblock size is a property of the UBI device, not 99 * of the UBI volume. Indeed, the logical eraseblock size depends on the 100 * physical eraseblock size and on how much bytes UBI headers consume. But 101 * because of the volume alignment (@alignment), the usable size of logical 102 * eraseblocks if a volume may be less. The following equation is true: 103 * @usable_leb_size = LEB size - (LEB size mod @alignment), 104 * where LEB size is the logical eraseblock size defined by the UBI device. 105 * 106 * The alignment is multiple to the minimal flash input/output unit size or %1 107 * if all the available space is used. 108 * 109 * To put this differently, alignment may be considered is a way to change 110 * volume logical eraseblock sizes. 111 */ 112 struct ubi_volume_info { 113 int ubi_num; 114 int vol_id; 115 int size; 116 long long used_bytes; 117 int used_ebs; 118 int vol_type; 119 int corrupted; 120 int upd_marker; 121 int alignment; 122 int usable_leb_size; 123 int name_len; 124 const char *name; 125 dev_t cdev; 126 }; 127 128 /** 129 * struct ubi_sgl - UBI scatter gather list data structure. 130 * @list_pos: current position in @sg[] 131 * @page_pos: current position in @sg[@list_pos] 132 * @sg: the scatter gather list itself 133 * 134 * ubi_sgl is a wrapper around a scatter list which keeps track of the 135 * current position in the list and the current list item such that 136 * it can be used across multiple ubi_leb_read_sg() calls. 137 */ 138 struct ubi_sgl { 139 int list_pos; 140 int page_pos; 141 struct scatterlist sg[UBI_MAX_SG_COUNT]; 142 }; 143 144 /** 145 * ubi_sgl_init - initialize an UBI scatter gather list data structure. 146 * @usgl: the UBI scatter gather struct itself 147 * 148 * Please note that you still have to use sg_init_table() or any adequate 149 * function to initialize the unterlaying struct scatterlist. 150 */ 151 static inline void ubi_sgl_init(struct ubi_sgl *usgl) 152 { 153 usgl->list_pos = 0; 154 usgl->page_pos = 0; 155 } 156 157 /** 158 * struct ubi_device_info - UBI device description data structure. 159 * @ubi_num: ubi device number 160 * @leb_size: logical eraseblock size on this UBI device 161 * @leb_start: starting offset of logical eraseblocks within physical 162 * eraseblocks 163 * @min_io_size: minimal I/O unit size 164 * @max_write_size: maximum amount of bytes the underlying flash can write at a 165 * time (MTD write buffer size) 166 * @ro_mode: if this device is in read-only mode 167 * @cdev: UBI character device major and minor numbers 168 * 169 * Note, @leb_size is the logical eraseblock size offered by the UBI device. 170 * Volumes of this UBI device may have smaller logical eraseblock size if their 171 * alignment is not equivalent to %1. 172 * 173 * The @max_write_size field describes flash write maximum write unit. For 174 * example, NOR flash allows for changing individual bytes, so @min_io_size is 175 * %1. However, it does not mean than NOR flash has to write data byte-by-byte. 176 * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when 177 * writing large chunks of data, they write 64-bytes at a time. Obviously, this 178 * improves write throughput. 179 * 180 * Also, the MTD device may have N interleaved (striped) flash chips 181 * underneath, in which case @min_io_size can be physical min. I/O size of 182 * single flash chip, while @max_write_size can be N * @min_io_size. 183 * 184 * The @max_write_size field is always greater or equivalent to @min_io_size. 185 * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In 186 * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND 187 * page size. 188 */ 189 struct ubi_device_info { 190 int ubi_num; 191 int leb_size; 192 int leb_start; 193 int min_io_size; 194 int max_write_size; 195 int ro_mode; 196 dev_t cdev; 197 }; 198 199 /* 200 * Volume notification types. 201 * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a 202 * volume was created) 203 * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached 204 * or a volume was removed) 205 * @UBI_VOLUME_RESIZED: a volume has been re-sized 206 * @UBI_VOLUME_RENAMED: a volume has been re-named 207 * @UBI_VOLUME_UPDATED: data has been written to a volume 208 * 209 * These constants define which type of event has happened when a volume 210 * notification function is invoked. 211 */ 212 enum { 213 UBI_VOLUME_ADDED, 214 UBI_VOLUME_REMOVED, 215 UBI_VOLUME_RESIZED, 216 UBI_VOLUME_RENAMED, 217 UBI_VOLUME_UPDATED, 218 }; 219 220 /* 221 * struct ubi_notification - UBI notification description structure. 222 * @di: UBI device description object 223 * @vi: UBI volume description object 224 * 225 * UBI notifiers are called with a pointer to an object of this type. The 226 * object describes the notification. Namely, it provides a description of the 227 * UBI device and UBI volume the notification informs about. 228 */ 229 struct ubi_notification { 230 struct ubi_device_info di; 231 struct ubi_volume_info vi; 232 }; 233 234 /* UBI descriptor given to users when they open UBI volumes */ 235 struct ubi_volume_desc; 236 237 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di); 238 void ubi_get_volume_info(struct ubi_volume_desc *desc, 239 struct ubi_volume_info *vi); 240 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode); 241 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, 242 int mode); 243 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode); 244 245 int ubi_register_volume_notifier(struct notifier_block *nb, 246 int ignore_existing); 247 int ubi_unregister_volume_notifier(struct notifier_block *nb); 248 249 void ubi_close_volume(struct ubi_volume_desc *desc); 250 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, 251 int len, int check); 252 int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl, 253 int offset, int len, int check); 254 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, 255 int offset, int len); 256 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, 257 int len); 258 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum); 259 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum); 260 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum); 261 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum); 262 int ubi_sync(int ubi_num); 263 int ubi_flush(int ubi_num, int vol_id, int lnum); 264 265 /* 266 * This function is the same as the 'ubi_leb_read()' function, but it does not 267 * provide the checking capability. 268 */ 269 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf, 270 int offset, int len) 271 { 272 return ubi_leb_read(desc, lnum, buf, offset, len, 0); 273 } 274 275 /* 276 * This function is the same as the 'ubi_leb_read_sg()' function, but it does 277 * not provide the checking capability. 278 */ 279 static inline int ubi_read_sg(struct ubi_volume_desc *desc, int lnum, 280 struct ubi_sgl *sgl, int offset, int len) 281 { 282 return ubi_leb_read_sg(desc, lnum, sgl, offset, len, 0); 283 } 284 #endif /* !__LINUX_UBI_H__ */ 285