1 /* 2 * Copyright (c) International Business Machines Corp., 2006 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 * 6 * Author: Artem Bityutskiy (Битюцкий Артём) 7 */ 8 9 #ifndef __LINUX_UBI_H__ 10 #define __LINUX_UBI_H__ 11 12 #include <linux/types.h> 13 #ifndef __UBOOT__ 14 #include <linux/ioctl.h> 15 #include <linux/scatterlist.h> 16 #include <mtd/ubi-user.h> 17 #endif 18 19 /* All voumes/LEBs */ 20 #define UBI_ALL -1 21 22 /* 23 * Maximum number of scatter gather list entries, 24 * we use only 64 to have a lower memory foot print. 25 */ 26 #define UBI_MAX_SG_COUNT 64 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 * UBI_METAONLY: modify only the volume meta-data, 35 * i.e. the data stored in the volume table, but not in any of volume LEBs. 36 */ 37 enum { 38 UBI_READONLY = 1, 39 UBI_READWRITE, 40 UBI_EXCLUSIVE, 41 UBI_METAONLY 42 }; 43 44 /** 45 * struct ubi_volume_info - UBI volume description data structure. 46 * @vol_id: volume ID 47 * @ubi_num: UBI device number this volume belongs to 48 * @size: how many physical eraseblocks are reserved for this volume 49 * @used_bytes: how many bytes of data this volume contains 50 * @used_ebs: how many physical eraseblocks of this volume actually contain any 51 * data 52 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 53 * @corrupted: non-zero if the volume is corrupted (static volumes only) 54 * @upd_marker: non-zero if the volume has update marker set 55 * @alignment: volume alignment 56 * @usable_leb_size: how many bytes are available in logical eraseblocks of 57 * this volume 58 * @name_len: volume name length 59 * @name: volume name 60 * @cdev: UBI volume character device major and minor numbers 61 * 62 * The @corrupted flag is only relevant to static volumes and is always zero 63 * for dynamic ones. This is because UBI does not care about dynamic volume 64 * data protection and only cares about protecting static volume data. 65 * 66 * The @upd_marker flag is set if the volume update operation was interrupted. 67 * Before touching the volume data during the update operation, UBI first sets 68 * the update marker flag for this volume. If the volume update operation was 69 * further interrupted, the update marker indicates this. If the update marker 70 * is set, the contents of the volume is certainly damaged and a new volume 71 * update operation has to be started. 72 * 73 * To put it differently, @corrupted and @upd_marker fields have different 74 * semantics: 75 * o the @corrupted flag means that this static volume is corrupted for some 76 * reasons, but not because an interrupted volume update 77 * o the @upd_marker field means that the volume is damaged because of an 78 * interrupted update operation. 79 * 80 * I.e., the @corrupted flag is never set if the @upd_marker flag is set. 81 * 82 * The @used_bytes and @used_ebs fields are only really needed for static 83 * volumes and contain the number of bytes stored in this static volume and how 84 * many eraseblock this data occupies. In case of dynamic volumes, the 85 * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs 86 * field is equivalent to @size. 87 * 88 * In general, logical eraseblock size is a property of the UBI device, not 89 * of the UBI volume. Indeed, the logical eraseblock size depends on the 90 * physical eraseblock size and on how much bytes UBI headers consume. But 91 * because of the volume alignment (@alignment), the usable size of logical 92 * eraseblocks if a volume may be less. The following equation is true: 93 * @usable_leb_size = LEB size - (LEB size mod @alignment), 94 * where LEB size is the logical eraseblock size defined by the UBI device. 95 * 96 * The alignment is multiple to the minimal flash input/output unit size or %1 97 * if all the available space is used. 98 * 99 * To put this differently, alignment may be considered is a way to change 100 * volume logical eraseblock sizes. 101 */ 102 struct ubi_volume_info { 103 int ubi_num; 104 int vol_id; 105 int size; 106 long long used_bytes; 107 int used_ebs; 108 int vol_type; 109 int corrupted; 110 int upd_marker; 111 int alignment; 112 int usable_leb_size; 113 int name_len; 114 const char *name; 115 dev_t cdev; 116 }; 117 118 /** 119 * struct ubi_sgl - UBI scatter gather list data structure. 120 * @list_pos: current position in @sg[] 121 * @page_pos: current position in @sg[@list_pos] 122 * @sg: the scatter gather list itself 123 * 124 * ubi_sgl is a wrapper around a scatter list which keeps track of the 125 * current position in the list and the current list item such that 126 * it can be used across multiple ubi_leb_read_sg() calls. 127 */ 128 struct ubi_sgl { 129 int list_pos; 130 int page_pos; 131 #ifndef __UBOOT__ 132 struct scatterlist sg[UBI_MAX_SG_COUNT]; 133 #endif 134 }; 135 136 /** 137 * ubi_sgl_init - initialize an UBI scatter gather list data structure. 138 * @usgl: the UBI scatter gather struct itself 139 * 140 * Please note that you still have to use sg_init_table() or any adequate 141 * function to initialize the unterlaying struct scatterlist. 142 */ 143 static inline void ubi_sgl_init(struct ubi_sgl *usgl) 144 { 145 usgl->list_pos = 0; 146 usgl->page_pos = 0; 147 } 148 149 /** 150 * struct ubi_device_info - UBI device description data structure. 151 * @ubi_num: ubi device number 152 * @leb_size: logical eraseblock size on this UBI device 153 * @leb_start: starting offset of logical eraseblocks within physical 154 * eraseblocks 155 * @min_io_size: minimal I/O unit size 156 * @max_write_size: maximum amount of bytes the underlying flash can write at a 157 * time (MTD write buffer size) 158 * @ro_mode: if this device is in read-only mode 159 * @cdev: UBI character device major and minor numbers 160 * 161 * Note, @leb_size is the logical eraseblock size offered by the UBI device. 162 * Volumes of this UBI device may have smaller logical eraseblock size if their 163 * alignment is not equivalent to %1. 164 * 165 * The @max_write_size field describes flash write maximum write unit. For 166 * example, NOR flash allows for changing individual bytes, so @min_io_size is 167 * %1. However, it does not mean than NOR flash has to write data byte-by-byte. 168 * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when 169 * writing large chunks of data, they write 64-bytes at a time. Obviously, this 170 * improves write throughput. 171 * 172 * Also, the MTD device may have N interleaved (striped) flash chips 173 * underneath, in which case @min_io_size can be physical min. I/O size of 174 * single flash chip, while @max_write_size can be N * @min_io_size. 175 * 176 * The @max_write_size field is always greater or equivalent to @min_io_size. 177 * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In 178 * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND 179 * page size. 180 */ 181 struct ubi_device_info { 182 int ubi_num; 183 int leb_size; 184 int leb_start; 185 int min_io_size; 186 int max_write_size; 187 int ro_mode; 188 #ifndef __UBOOT__ 189 dev_t cdev; 190 #endif 191 }; 192 193 /* 194 * Volume notification types. 195 * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a 196 * volume was created) 197 * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached 198 * or a volume was removed) 199 * @UBI_VOLUME_RESIZED: a volume has been re-sized 200 * @UBI_VOLUME_RENAMED: a volume has been re-named 201 * @UBI_VOLUME_UPDATED: data has been written to a volume 202 * 203 * These constants define which type of event has happened when a volume 204 * notification function is invoked. 205 */ 206 enum { 207 UBI_VOLUME_ADDED, 208 UBI_VOLUME_REMOVED, 209 UBI_VOLUME_RESIZED, 210 UBI_VOLUME_RENAMED, 211 UBI_VOLUME_UPDATED, 212 }; 213 214 /* 215 * struct ubi_notification - UBI notification description structure. 216 * @di: UBI device description object 217 * @vi: UBI volume description object 218 * 219 * UBI notifiers are called with a pointer to an object of this type. The 220 * object describes the notification. Namely, it provides a description of the 221 * UBI device and UBI volume the notification informs about. 222 */ 223 struct ubi_notification { 224 struct ubi_device_info di; 225 struct ubi_volume_info vi; 226 }; 227 228 /* UBI descriptor given to users when they open UBI volumes */ 229 struct ubi_volume_desc; 230 231 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di); 232 void ubi_get_volume_info(struct ubi_volume_desc *desc, 233 struct ubi_volume_info *vi); 234 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode); 235 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, 236 int mode); 237 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode); 238 239 #ifndef __UBOOT__ 240 typedef int (*notifier_fn_t)(void *nb, 241 unsigned long action, void *data); 242 243 struct notifier_block { 244 notifier_fn_t notifier_call; 245 struct notifier_block *next; 246 void *next; 247 int priority; 248 }; 249 250 int ubi_register_volume_notifier(struct notifier_block *nb, 251 int ignore_existing); 252 int ubi_unregister_volume_notifier(struct notifier_block *nb); 253 #endif 254 255 void ubi_close_volume(struct ubi_volume_desc *desc); 256 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, 257 int len, int check); 258 int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl, 259 int offset, int len, int check); 260 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, 261 int offset, int len); 262 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, 263 int len); 264 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum); 265 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum); 266 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum); 267 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum); 268 int ubi_sync(int ubi_num); 269 int ubi_flush(int ubi_num, int vol_id, int lnum); 270 271 /* 272 * This function is the same as the 'ubi_leb_read()' function, but it does not 273 * provide the checking capability. 274 */ 275 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf, 276 int offset, int len) 277 { 278 return ubi_leb_read(desc, lnum, buf, offset, len, 0); 279 } 280 281 /* 282 * This function is the same as the 'ubi_leb_read_sg()' function, but it does 283 * not provide the checking capability. 284 */ 285 static inline int ubi_read_sg(struct ubi_volume_desc *desc, int lnum, 286 struct ubi_sgl *sgl, int offset, int len) 287 { 288 return ubi_leb_read_sg(desc, lnum, sgl, offset, len, 0); 289 } 290 #endif /* !__LINUX_UBI_H__ */ 291