1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 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/ioctl.h> 12 #include <linux/types.h> 13 #include <linux/scatterlist.h> 14 #include <mtd/ubi-user.h> 15 16 /* All voumes/LEBs */ 17 #define UBI_ALL -1 18 19 /* 20 * Maximum number of scatter gather list entries, 21 * we use only 64 to have a lower memory foot print. 22 */ 23 #define UBI_MAX_SG_COUNT 64 24 25 /* 26 * enum ubi_open_mode - UBI volume open mode constants. 27 * 28 * UBI_READONLY: read-only mode 29 * UBI_READWRITE: read-write mode 30 * UBI_EXCLUSIVE: exclusive mode 31 * UBI_METAONLY: modify only the volume meta-data, 32 * i.e. the data stored in the volume table, but not in any of volume LEBs. 33 */ 34 enum { 35 UBI_READONLY = 1, 36 UBI_READWRITE, 37 UBI_EXCLUSIVE, 38 UBI_METAONLY 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 struct device *dev; 114 }; 115 116 /** 117 * struct ubi_sgl - UBI scatter gather list data structure. 118 * @list_pos: current position in @sg[] 119 * @page_pos: current position in @sg[@list_pos] 120 * @sg: the scatter gather list itself 121 * 122 * ubi_sgl is a wrapper around a scatter list which keeps track of the 123 * current position in the list and the current list item such that 124 * it can be used across multiple ubi_leb_read_sg() calls. 125 */ 126 struct ubi_sgl { 127 int list_pos; 128 int page_pos; 129 struct scatterlist sg[UBI_MAX_SG_COUNT]; 130 }; 131 132 /** 133 * ubi_sgl_init - initialize an UBI scatter gather list data structure. 134 * @usgl: the UBI scatter gather struct itself 135 * 136 * Please note that you still have to use sg_init_table() or any adequate 137 * function to initialize the unterlaying struct scatterlist. 138 */ 139 static inline void ubi_sgl_init(struct ubi_sgl *usgl) 140 { 141 usgl->list_pos = 0; 142 usgl->page_pos = 0; 143 } 144 145 /** 146 * struct ubi_device_info - UBI device description data structure. 147 * @ubi_num: ubi device number 148 * @leb_size: logical eraseblock size on this UBI device 149 * @leb_start: starting offset of logical eraseblocks within physical 150 * eraseblocks 151 * @min_io_size: minimal I/O unit size 152 * @max_write_size: maximum amount of bytes the underlying flash can write at a 153 * time (MTD write buffer size) 154 * @ro_mode: if this device is in read-only mode 155 * @cdev: UBI character device major and minor numbers 156 * 157 * Note, @leb_size is the logical eraseblock size offered by the UBI device. 158 * Volumes of this UBI device may have smaller logical eraseblock size if their 159 * alignment is not equivalent to %1. 160 * 161 * The @max_write_size field describes flash write maximum write unit. For 162 * example, NOR flash allows for changing individual bytes, so @min_io_size is 163 * %1. However, it does not mean than NOR flash has to write data byte-by-byte. 164 * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when 165 * writing large chunks of data, they write 64-bytes at a time. Obviously, this 166 * improves write throughput. 167 * 168 * Also, the MTD device may have N interleaved (striped) flash chips 169 * underneath, in which case @min_io_size can be physical min. I/O size of 170 * single flash chip, while @max_write_size can be N * @min_io_size. 171 * 172 * The @max_write_size field is always greater or equivalent to @min_io_size. 173 * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In 174 * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND 175 * page size. 176 */ 177 struct ubi_device_info { 178 int ubi_num; 179 int leb_size; 180 int leb_start; 181 int min_io_size; 182 int max_write_size; 183 int ro_mode; 184 dev_t cdev; 185 }; 186 187 /* 188 * Volume notification types. 189 * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a 190 * volume was created) 191 * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached 192 * or a volume was removed) 193 * @UBI_VOLUME_RESIZED: a volume has been re-sized 194 * @UBI_VOLUME_RENAMED: a volume has been re-named 195 * @UBI_VOLUME_UPDATED: data has been written to a volume 196 * 197 * These constants define which type of event has happened when a volume 198 * notification function is invoked. 199 */ 200 enum { 201 UBI_VOLUME_ADDED, 202 UBI_VOLUME_REMOVED, 203 UBI_VOLUME_RESIZED, 204 UBI_VOLUME_RENAMED, 205 UBI_VOLUME_UPDATED, 206 }; 207 208 /* 209 * struct ubi_notification - UBI notification description structure. 210 * @di: UBI device description object 211 * @vi: UBI volume description object 212 * 213 * UBI notifiers are called with a pointer to an object of this type. The 214 * object describes the notification. Namely, it provides a description of the 215 * UBI device and UBI volume the notification informs about. 216 */ 217 struct ubi_notification { 218 struct ubi_device_info di; 219 struct ubi_volume_info vi; 220 }; 221 222 /* UBI descriptor given to users when they open UBI volumes */ 223 struct ubi_volume_desc; 224 225 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di); 226 void ubi_get_volume_info(struct ubi_volume_desc *desc, 227 struct ubi_volume_info *vi); 228 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode); 229 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, 230 int mode); 231 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode); 232 233 int ubi_register_volume_notifier(struct notifier_block *nb, 234 int ignore_existing); 235 int ubi_unregister_volume_notifier(struct notifier_block *nb); 236 237 void ubi_close_volume(struct ubi_volume_desc *desc); 238 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, 239 int len, int check); 240 int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl, 241 int offset, int len, int check); 242 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, 243 int offset, int len); 244 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, 245 int len); 246 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum); 247 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum); 248 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum); 249 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum); 250 int ubi_sync(int ubi_num); 251 int ubi_flush(int ubi_num, int vol_id, int lnum); 252 253 /* 254 * This function is the same as the 'ubi_leb_read()' function, but it does not 255 * provide the checking capability. 256 */ 257 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf, 258 int offset, int len) 259 { 260 return ubi_leb_read(desc, lnum, buf, offset, len, 0); 261 } 262 263 /* 264 * This function is the same as the 'ubi_leb_read_sg()' function, but it does 265 * not provide the checking capability. 266 */ 267 static inline int ubi_read_sg(struct ubi_volume_desc *desc, int lnum, 268 struct ubi_sgl *sgl, int offset, int len) 269 { 270 return ubi_leb_read_sg(desc, lnum, sgl, offset, len, 0); 271 } 272 #endif /* !__LINUX_UBI_H__ */ 273