1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Copyright (c) International Business Machines Corp., 2006 4 * 5 * Author: Artem Bityutskiy (Битюцкий Артём) 6 */ 7 8 #ifndef __LINUX_UBI_H__ 9 #define __LINUX_UBI_H__ 10 11 #include <linux/types.h> 12 #ifndef __UBOOT__ 13 #include <linux/ioctl.h> 14 #include <linux/scatterlist.h> 15 #include <mtd/ubi-user.h> 16 #endif 17 18 /* All voumes/LEBs */ 19 #define UBI_ALL -1 20 21 /* 22 * Maximum number of scatter gather list entries, 23 * we use only 64 to have a lower memory foot print. 24 */ 25 #define UBI_MAX_SG_COUNT 64 26 27 /* 28 * enum ubi_open_mode - UBI volume open mode constants. 29 * 30 * UBI_READONLY: read-only mode 31 * UBI_READWRITE: read-write mode 32 * UBI_EXCLUSIVE: exclusive mode 33 * UBI_METAONLY: modify only the volume meta-data, 34 * i.e. the data stored in the volume table, but not in any of volume LEBs. 35 */ 36 enum { 37 UBI_READONLY = 1, 38 UBI_READWRITE, 39 UBI_EXCLUSIVE, 40 UBI_METAONLY 41 }; 42 43 /** 44 * struct ubi_volume_info - UBI volume description data structure. 45 * @vol_id: volume ID 46 * @ubi_num: UBI device number this volume belongs to 47 * @size: how many physical eraseblocks are reserved for this volume 48 * @used_bytes: how many bytes of data this volume contains 49 * @used_ebs: how many physical eraseblocks of this volume actually contain any 50 * data 51 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 52 * @corrupted: non-zero if the volume is corrupted (static volumes only) 53 * @upd_marker: non-zero if the volume has update marker set 54 * @alignment: volume alignment 55 * @usable_leb_size: how many bytes are available in logical eraseblocks of 56 * this volume 57 * @name_len: volume name length 58 * @name: volume name 59 * @cdev: UBI volume character device major and minor numbers 60 * 61 * The @corrupted flag is only relevant to static volumes and is always zero 62 * for dynamic ones. This is because UBI does not care about dynamic volume 63 * data protection and only cares about protecting static volume data. 64 * 65 * The @upd_marker flag is set if the volume update operation was interrupted. 66 * Before touching the volume data during the update operation, UBI first sets 67 * the update marker flag for this volume. If the volume update operation was 68 * further interrupted, the update marker indicates this. If the update marker 69 * is set, the contents of the volume is certainly damaged and a new volume 70 * update operation has to be started. 71 * 72 * To put it differently, @corrupted and @upd_marker fields have different 73 * semantics: 74 * o the @corrupted flag means that this static volume is corrupted for some 75 * reasons, but not because an interrupted volume update 76 * o the @upd_marker field means that the volume is damaged because of an 77 * interrupted update operation. 78 * 79 * I.e., the @corrupted flag is never set if the @upd_marker flag is set. 80 * 81 * The @used_bytes and @used_ebs fields are only really needed for static 82 * volumes and contain the number of bytes stored in this static volume and how 83 * many eraseblock this data occupies. In case of dynamic volumes, the 84 * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs 85 * field is equivalent to @size. 86 * 87 * In general, logical eraseblock size is a property of the UBI device, not 88 * of the UBI volume. Indeed, the logical eraseblock size depends on the 89 * physical eraseblock size and on how much bytes UBI headers consume. But 90 * because of the volume alignment (@alignment), the usable size of logical 91 * eraseblocks if a volume may be less. The following equation is true: 92 * @usable_leb_size = LEB size - (LEB size mod @alignment), 93 * where LEB size is the logical eraseblock size defined by the UBI device. 94 * 95 * The alignment is multiple to the minimal flash input/output unit size or %1 96 * if all the available space is used. 97 * 98 * To put this differently, alignment may be considered is a way to change 99 * volume logical eraseblock sizes. 100 */ 101 struct ubi_volume_info { 102 int ubi_num; 103 int vol_id; 104 int size; 105 long long used_bytes; 106 int used_ebs; 107 int vol_type; 108 int corrupted; 109 int upd_marker; 110 int alignment; 111 int usable_leb_size; 112 int name_len; 113 const char *name; 114 dev_t cdev; 115 }; 116 117 /** 118 * struct ubi_sgl - UBI scatter gather list data structure. 119 * @list_pos: current position in @sg[] 120 * @page_pos: current position in @sg[@list_pos] 121 * @sg: the scatter gather list itself 122 * 123 * ubi_sgl is a wrapper around a scatter list which keeps track of the 124 * current position in the list and the current list item such that 125 * it can be used across multiple ubi_leb_read_sg() calls. 126 */ 127 struct ubi_sgl { 128 int list_pos; 129 int page_pos; 130 #ifndef __UBOOT__ 131 struct scatterlist sg[UBI_MAX_SG_COUNT]; 132 #endif 133 }; 134 135 /** 136 * ubi_sgl_init - initialize an UBI scatter gather list data structure. 137 * @usgl: the UBI scatter gather struct itself 138 * 139 * Please note that you still have to use sg_init_table() or any adequate 140 * function to initialize the unterlaying struct scatterlist. 141 */ 142 static inline void ubi_sgl_init(struct ubi_sgl *usgl) 143 { 144 usgl->list_pos = 0; 145 usgl->page_pos = 0; 146 } 147 148 /** 149 * struct ubi_device_info - UBI device description data structure. 150 * @ubi_num: ubi device number 151 * @leb_size: logical eraseblock size on this UBI device 152 * @leb_start: starting offset of logical eraseblocks within physical 153 * eraseblocks 154 * @min_io_size: minimal I/O unit size 155 * @max_write_size: maximum amount of bytes the underlying flash can write at a 156 * time (MTD write buffer size) 157 * @ro_mode: if this device is in read-only mode 158 * @cdev: UBI character device major and minor numbers 159 * 160 * Note, @leb_size is the logical eraseblock size offered by the UBI device. 161 * Volumes of this UBI device may have smaller logical eraseblock size if their 162 * alignment is not equivalent to %1. 163 * 164 * The @max_write_size field describes flash write maximum write unit. For 165 * example, NOR flash allows for changing individual bytes, so @min_io_size is 166 * %1. However, it does not mean than NOR flash has to write data byte-by-byte. 167 * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when 168 * writing large chunks of data, they write 64-bytes at a time. Obviously, this 169 * improves write throughput. 170 * 171 * Also, the MTD device may have N interleaved (striped) flash chips 172 * underneath, in which case @min_io_size can be physical min. I/O size of 173 * single flash chip, while @max_write_size can be N * @min_io_size. 174 * 175 * The @max_write_size field is always greater or equivalent to @min_io_size. 176 * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In 177 * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND 178 * page size. 179 */ 180 struct ubi_device_info { 181 int ubi_num; 182 int leb_size; 183 int leb_start; 184 int min_io_size; 185 int max_write_size; 186 int ro_mode; 187 #ifndef __UBOOT__ 188 dev_t cdev; 189 #endif 190 }; 191 192 /* 193 * Volume notification types. 194 * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a 195 * volume was created) 196 * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached 197 * or a volume was removed) 198 * @UBI_VOLUME_RESIZED: a volume has been re-sized 199 * @UBI_VOLUME_RENAMED: a volume has been re-named 200 * @UBI_VOLUME_UPDATED: data has been written to a volume 201 * 202 * These constants define which type of event has happened when a volume 203 * notification function is invoked. 204 */ 205 enum { 206 UBI_VOLUME_ADDED, 207 UBI_VOLUME_REMOVED, 208 UBI_VOLUME_RESIZED, 209 UBI_VOLUME_RENAMED, 210 UBI_VOLUME_UPDATED, 211 }; 212 213 /* 214 * struct ubi_notification - UBI notification description structure. 215 * @di: UBI device description object 216 * @vi: UBI volume description object 217 * 218 * UBI notifiers are called with a pointer to an object of this type. The 219 * object describes the notification. Namely, it provides a description of the 220 * UBI device and UBI volume the notification informs about. 221 */ 222 struct ubi_notification { 223 struct ubi_device_info di; 224 struct ubi_volume_info vi; 225 }; 226 227 /* UBI descriptor given to users when they open UBI volumes */ 228 struct ubi_volume_desc; 229 230 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di); 231 void ubi_get_volume_info(struct ubi_volume_desc *desc, 232 struct ubi_volume_info *vi); 233 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode); 234 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, 235 int mode); 236 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode); 237 238 #ifndef __UBOOT__ 239 typedef int (*notifier_fn_t)(void *nb, 240 unsigned long action, void *data); 241 242 struct notifier_block { 243 notifier_fn_t notifier_call; 244 struct notifier_block *next; 245 void *next; 246 int priority; 247 }; 248 249 int ubi_register_volume_notifier(struct notifier_block *nb, 250 int ignore_existing); 251 int ubi_unregister_volume_notifier(struct notifier_block *nb); 252 #endif 253 254 void ubi_close_volume(struct ubi_volume_desc *desc); 255 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, 256 int len, int check); 257 int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl, 258 int offset, int len, int check); 259 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, 260 int offset, int len); 261 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, 262 int len); 263 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum); 264 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum); 265 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum); 266 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum); 267 int ubi_sync(int ubi_num); 268 int ubi_flush(int ubi_num, int vol_id, int lnum); 269 270 /* 271 * This function is the same as the 'ubi_leb_read()' function, but it does not 272 * provide the checking capability. 273 */ 274 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf, 275 int offset, int len) 276 { 277 return ubi_leb_read(desc, lnum, buf, offset, len, 0); 278 } 279 280 /* 281 * This function is the same as the 'ubi_leb_read_sg()' function, but it does 282 * not provide the checking capability. 283 */ 284 static inline int ubi_read_sg(struct ubi_volume_desc *desc, int lnum, 285 struct ubi_sgl *sgl, int offset, int len) 286 { 287 return ubi_leb_read_sg(desc, lnum, sgl, offset, len, 0); 288 } 289 #endif /* !__LINUX_UBI_H__ */ 290