1 /* 2 * Copyright © International Business Machines Corp., 2006 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 * 6 * Author: Artem Bityutskiy (Битюцкий Артём) 7 */ 8 9 #ifndef __UBI_USER_H__ 10 #define __UBI_USER_H__ 11 12 #include <linux/types.h> 13 14 /* 15 * UBI device creation (the same as MTD device attachment) 16 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 17 * 18 * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI 19 * control device. The caller has to properly fill and pass 20 * &struct ubi_attach_req object - UBI will attach the MTD device specified in 21 * the request and return the newly created UBI device number as the ioctl 22 * return value. 23 * 24 * UBI device deletion (the same as MTD device detachment) 25 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 26 * 27 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI 28 * control device. 29 * 30 * UBI volume creation 31 * ~~~~~~~~~~~~~~~~~~~ 32 * 33 * UBI volumes are created via the %UBI_IOCMKVOL ioctl command of UBI character 34 * device. A &struct ubi_mkvol_req object has to be properly filled and a 35 * pointer to it has to be passed to the ioctl. 36 * 37 * UBI volume deletion 38 * ~~~~~~~~~~~~~~~~~~~ 39 * 40 * To delete a volume, the %UBI_IOCRMVOL ioctl command of the UBI character 41 * device should be used. A pointer to the 32-bit volume ID hast to be passed 42 * to the ioctl. 43 * 44 * UBI volume re-size 45 * ~~~~~~~~~~~~~~~~~~ 46 * 47 * To re-size a volume, the %UBI_IOCRSVOL ioctl command of the UBI character 48 * device should be used. A &struct ubi_rsvol_req object has to be properly 49 * filled and a pointer to it has to be passed to the ioctl. 50 * 51 * UBI volumes re-name 52 * ~~~~~~~~~~~~~~~~~~~ 53 * 54 * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command 55 * of the UBI character device should be used. A &struct ubi_rnvol_req object 56 * has to be properly filled and a pointer to it has to be passed to the ioctl. 57 * 58 * UBI volume update 59 * ~~~~~~~~~~~~~~~~~ 60 * 61 * Volume update should be done via the %UBI_IOCVOLUP ioctl command of the 62 * corresponding UBI volume character device. A pointer to a 64-bit update 63 * size should be passed to the ioctl. After this, UBI expects user to write 64 * this number of bytes to the volume character device. The update is finished 65 * when the claimed number of bytes is passed. So, the volume update sequence 66 * is something like: 67 * 68 * fd = open("/dev/my_volume"); 69 * ioctl(fd, UBI_IOCVOLUP, &image_size); 70 * write(fd, buf, image_size); 71 * close(fd); 72 * 73 * Logical eraseblock erase 74 * ~~~~~~~~~~~~~~~~~~~~~~~~ 75 * 76 * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the 77 * corresponding UBI volume character device should be used. This command 78 * unmaps the requested logical eraseblock, makes sure the corresponding 79 * physical eraseblock is successfully erased, and returns. 80 * 81 * Atomic logical eraseblock change 82 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 83 * 84 * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH 85 * ioctl command of the corresponding UBI volume character device. A pointer to 86 * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the 87 * user is expected to write the requested amount of bytes (similarly to what 88 * should be done in case of the "volume update" ioctl). 89 * 90 * Logical eraseblock map 91 * ~~~~~~~~~~~~~~~~~~~~~ 92 * 93 * To map a logical eraseblock to a physical eraseblock, the %UBI_IOCEBMAP 94 * ioctl command should be used. A pointer to a &struct ubi_map_req object is 95 * expected to be passed. The ioctl maps the requested logical eraseblock to 96 * a physical eraseblock and returns. Only non-mapped logical eraseblocks can 97 * be mapped. If the logical eraseblock specified in the request is already 98 * mapped to a physical eraseblock, the ioctl fails and returns error. 99 * 100 * Logical eraseblock unmap 101 * ~~~~~~~~~~~~~~~~~~~~~~~~ 102 * 103 * To unmap a logical eraseblock to a physical eraseblock, the %UBI_IOCEBUNMAP 104 * ioctl command should be used. The ioctl unmaps the logical eraseblocks, 105 * schedules corresponding physical eraseblock for erasure, and returns. Unlike 106 * the "LEB erase" command, it does not wait for the physical eraseblock being 107 * erased. Note, the side effect of this is that if an unclean reboot happens 108 * after the unmap ioctl returns, you may find the LEB mapped again to the same 109 * physical eraseblock after the UBI is run again. 110 * 111 * Check if logical eraseblock is mapped 112 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 113 * 114 * To check if a logical eraseblock is mapped to a physical eraseblock, the 115 * %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is 116 * not mapped, and %1 if it is mapped. 117 * 118 * Set an UBI volume property 119 * ~~~~~~~~~~~~~~~~~~~~~~~~~ 120 * 121 * To set an UBI volume property the %UBI_IOCSETPROP ioctl command should be 122 * used. A pointer to a &struct ubi_set_vol_prop_req object is expected to be 123 * passed. The object describes which property should be set, and to which value 124 * it should be set. 125 * 126 * Block devices on UBI volumes 127 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 128 * 129 * To create a R/O block device on top of an UBI volume the %UBI_IOCVOLCRBLK 130 * should be used. A pointer to a &struct ubi_blkcreate_req object is expected 131 * to be passed, which is not used and reserved for future usage. 132 * 133 * Conversely, to remove a block device the %UBI_IOCVOLRMBLK should be used, 134 * which takes no arguments. 135 */ 136 137 /* 138 * When a new UBI volume or UBI device is created, users may either specify the 139 * volume/device number they want to create or to let UBI automatically assign 140 * the number using these constants. 141 */ 142 #define UBI_VOL_NUM_AUTO (-1) 143 #define UBI_DEV_NUM_AUTO (-1) 144 145 /* Maximum volume name length */ 146 #define UBI_MAX_VOLUME_NAME 127 147 148 /* ioctl commands of UBI character devices */ 149 150 #define UBI_IOC_MAGIC 'o' 151 152 /* Create an UBI volume */ 153 #define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req) 154 /* Remove an UBI volume */ 155 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, __s32) 156 /* Re-size an UBI volume */ 157 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req) 158 /* Re-name volumes */ 159 #define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req) 160 161 /* ioctl commands of the UBI control character device */ 162 163 #define UBI_CTRL_IOC_MAGIC 'o' 164 165 /* Attach an MTD device */ 166 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req) 167 /* Detach an MTD device */ 168 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, __s32) 169 170 /* ioctl commands of UBI volume character devices */ 171 172 #define UBI_VOL_IOC_MAGIC 'O' 173 174 /* Start UBI volume update 175 * Note: This actually takes a pointer (__s64*), but we can't change 176 * that without breaking the ABI on 32bit systems 177 */ 178 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, __s64) 179 /* LEB erasure command, used for debugging, disabled by default */ 180 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, __s32) 181 /* Atomic LEB change command */ 182 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, __s32) 183 /* Map LEB command */ 184 #define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req) 185 /* Unmap LEB command */ 186 #define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, __s32) 187 /* Check if LEB is mapped command */ 188 #define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, __s32) 189 /* Set an UBI volume property */ 190 #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \ 191 struct ubi_set_vol_prop_req) 192 /* Create a R/O block device on top of an UBI volume */ 193 #define UBI_IOCVOLCRBLK _IOW(UBI_VOL_IOC_MAGIC, 7, struct ubi_blkcreate_req) 194 /* Remove the R/O block device */ 195 #define UBI_IOCVOLRMBLK _IO(UBI_VOL_IOC_MAGIC, 8) 196 197 /* Maximum MTD device name length supported by UBI */ 198 #define MAX_UBI_MTD_NAME_LEN 127 199 200 /* Maximum amount of UBI volumes that can be re-named at one go */ 201 #define UBI_MAX_RNVOL 32 202 203 /* 204 * UBI volume type constants. 205 * 206 * @UBI_DYNAMIC_VOLUME: dynamic volume 207 * @UBI_STATIC_VOLUME: static volume 208 */ 209 enum { 210 UBI_DYNAMIC_VOLUME = 3, 211 UBI_STATIC_VOLUME = 4, 212 }; 213 214 /* 215 * UBI set volume property ioctl constants. 216 * 217 * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0) 218 * user to directly write and erase individual 219 * eraseblocks on dynamic volumes 220 */ 221 enum { 222 UBI_VOL_PROP_DIRECT_WRITE = 1, 223 }; 224 225 /** 226 * struct ubi_attach_req - attach MTD device request. 227 * @ubi_num: UBI device number to create 228 * @mtd_num: MTD device number to attach 229 * @vid_hdr_offset: VID header offset (use defaults if %0) 230 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs 231 * @padding: reserved for future, not used, has to be zeroed 232 * 233 * This data structure is used to specify MTD device UBI has to attach and the 234 * parameters it has to use. The number which should be assigned to the new UBI 235 * device is passed in @ubi_num. UBI may automatically assign the number if 236 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in 237 * @ubi_num. 238 * 239 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default 240 * offset of the VID header within physical eraseblocks. The default offset is 241 * the next min. I/O unit after the EC header. For example, it will be offset 242 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or 243 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages. 244 * 245 * But in rare cases, if this optimizes things, the VID header may be placed to 246 * a different offset. For example, the boot-loader might do things faster if 247 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages. 248 * As the boot-loader would not normally need to read EC headers (unless it 249 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird 250 * example, but it real-life example. So, in this example, @vid_hdr_offer would 251 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes 252 * aligned, which is OK, as UBI is clever enough to realize this is 4th 253 * sub-page of the first page and add needed padding. 254 * 255 * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the 256 * UBI device per 1024 eraseblocks. This value is often given in an other form 257 * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The 258 * maximum expected bad eraseblocks per 1024 is then: 259 * 1024 * (1 - MinNVB / MaxNVB) 260 * Which gives 20 for most NAND devices. This limit is used in order to derive 261 * amount of eraseblock UBI reserves for handling new bad blocks. If the device 262 * has more bad eraseblocks than this limit, UBI does not reserve any physical 263 * eraseblocks for new bad eraseblocks, but attempts to use available 264 * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the 265 * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used. 266 */ 267 struct ubi_attach_req { 268 __s32 ubi_num; 269 __s32 mtd_num; 270 __s32 vid_hdr_offset; 271 __s16 max_beb_per1024; 272 __s8 padding[10]; 273 }; 274 275 /** 276 * struct ubi_mkvol_req - volume description data structure used in 277 * volume creation requests. 278 * @vol_id: volume number 279 * @alignment: volume alignment 280 * @bytes: volume size in bytes 281 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 282 * @padding1: reserved for future, not used, has to be zeroed 283 * @name_len: volume name length 284 * @padding2: reserved for future, not used, has to be zeroed 285 * @name: volume name 286 * 287 * This structure is used by user-space programs when creating new volumes. The 288 * @used_bytes field is only necessary when creating static volumes. 289 * 290 * The @alignment field specifies the required alignment of the volume logical 291 * eraseblock. This means, that the size of logical eraseblocks will be aligned 292 * to this number, i.e., 293 * (UBI device logical eraseblock size) mod (@alignment) = 0. 294 * 295 * To put it differently, the logical eraseblock of this volume may be slightly 296 * shortened in order to make it properly aligned. The alignment has to be 297 * multiple of the flash minimal input/output unit, or %1 to utilize the entire 298 * available space of logical eraseblocks. 299 * 300 * The @alignment field may be useful, for example, when one wants to maintain 301 * a block device on top of an UBI volume. In this case, it is desirable to fit 302 * an integer number of blocks in logical eraseblocks of this UBI volume. With 303 * alignment it is possible to update this volume using plane UBI volume image 304 * BLOBs, without caring about how to properly align them. 305 */ 306 struct ubi_mkvol_req { 307 __s32 vol_id; 308 __s32 alignment; 309 __s64 bytes; 310 __s8 vol_type; 311 __s8 padding1; 312 __s16 name_len; 313 __s8 padding2[4]; 314 char name[UBI_MAX_VOLUME_NAME + 1]; 315 } __packed; 316 317 /** 318 * struct ubi_rsvol_req - a data structure used in volume re-size requests. 319 * @vol_id: ID of the volume to re-size 320 * @bytes: new size of the volume in bytes 321 * 322 * Re-sizing is possible for both dynamic and static volumes. But while dynamic 323 * volumes may be re-sized arbitrarily, static volumes cannot be made to be 324 * smaller than the number of bytes they bear. To arbitrarily shrink a static 325 * volume, it must be wiped out first (by means of volume update operation with 326 * zero number of bytes). 327 */ 328 struct ubi_rsvol_req { 329 __s64 bytes; 330 __s32 vol_id; 331 } __packed; 332 333 /** 334 * struct ubi_rnvol_req - volumes re-name request. 335 * @count: count of volumes to re-name 336 * @padding1: reserved for future, not used, has to be zeroed 337 * @vol_id: ID of the volume to re-name 338 * @name_len: name length 339 * @padding2: reserved for future, not used, has to be zeroed 340 * @name: new volume name 341 * 342 * UBI allows to re-name up to %32 volumes at one go. The count of volumes to 343 * re-name is specified in the @count field. The ID of the volumes to re-name 344 * and the new names are specified in the @vol_id and @name fields. 345 * 346 * The UBI volume re-name operation is atomic, which means that should power cut 347 * happen, the volumes will have either old name or new name. So the possible 348 * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes 349 * A and B one may create temporary volumes %A1 and %B1 with the new contents, 350 * then atomically re-name A1->A and B1->B, in which case old %A and %B will 351 * be removed. 352 * 353 * If it is not desirable to remove old A and B, the re-name request has to 354 * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1 355 * become A and B, and old A and B will become A1 and B1. 356 * 357 * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1 358 * and B1 become A and B, and old A and B become X and Y. 359 * 360 * In other words, in case of re-naming into an existing volume name, the 361 * existing volume is removed, unless it is re-named as well at the same 362 * re-name request. 363 */ 364 struct ubi_rnvol_req { 365 __s32 count; 366 __s8 padding1[12]; 367 struct { 368 __s32 vol_id; 369 __s16 name_len; 370 __s8 padding2[2]; 371 char name[UBI_MAX_VOLUME_NAME + 1]; 372 } ents[UBI_MAX_RNVOL]; 373 } __packed; 374 375 /** 376 * struct ubi_leb_change_req - a data structure used in atomic LEB change 377 * requests. 378 * @lnum: logical eraseblock number to change 379 * @bytes: how many bytes will be written to the logical eraseblock 380 * @dtype: pass "3" for better compatibility with old kernels 381 * @padding: reserved for future, not used, has to be zeroed 382 * 383 * The @dtype field used to inform UBI about what kind of data will be written 384 * to the LEB: long term (value 1), short term (value 2), unknown (value 3). 385 * UBI tried to pick a PEB with lower erase counter for short term data and a 386 * PEB with higher erase counter for long term data. But this was not really 387 * used because users usually do not know this and could easily mislead UBI. We 388 * removed this feature in May 2012. UBI currently just ignores the @dtype 389 * field. But for better compatibility with older kernels it is recommended to 390 * set @dtype to 3 (unknown). 391 */ 392 struct ubi_leb_change_req { 393 __s32 lnum; 394 __s32 bytes; 395 __s8 dtype; /* obsolete, do not use! */ 396 __s8 padding[7]; 397 } __packed; 398 399 /** 400 * struct ubi_map_req - a data structure used in map LEB requests. 401 * @dtype: pass "3" for better compatibility with old kernels 402 * @lnum: logical eraseblock number to unmap 403 * @padding: reserved for future, not used, has to be zeroed 404 */ 405 struct ubi_map_req { 406 __s32 lnum; 407 __s8 dtype; /* obsolete, do not use! */ 408 __s8 padding[3]; 409 } __packed; 410 411 412 /** 413 * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume 414 * property. 415 * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE) 416 * @padding: reserved for future, not used, has to be zeroed 417 * @value: value to set 418 */ 419 struct ubi_set_vol_prop_req { 420 __u8 property; 421 __u8 padding[7]; 422 __u64 value; 423 } __packed; 424 425 /** 426 * struct ubi_blkcreate_req - a data structure used in block creation requests. 427 * @padding: reserved for future, not used, has to be zeroed 428 */ 429 struct ubi_blkcreate_req { 430 __s8 padding[128]; 431 } __packed; 432 433 #endif /* __UBI_USER_H__ */ 434