ubi-user.h (18556B) - Raw
1 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ 2 /* 3 * Copyright © International Business Machines Corp., 2006 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 13 * the GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 * 19 * Author: Artem Bityutskiy (Битюцкий Артём) 20 */ 21 22 #ifndef __UBI_USER_H__ 23 #define __UBI_USER_H__ 24 25 #include <linux/types.h> 26 27 /* 28 * UBI device creation (the same as MTD device attachment) 29 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 30 * 31 * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI 32 * control device. The caller has to properly fill and pass 33 * &struct ubi_attach_req object - UBI will attach the MTD device specified in 34 * the request and return the newly created UBI device number as the ioctl 35 * return value. 36 * 37 * UBI device deletion (the same as MTD device detachment) 38 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 39 * 40 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI 41 * control device. 42 * 43 * UBI volume creation 44 * ~~~~~~~~~~~~~~~~~~~ 45 * 46 * UBI volumes are created via the %UBI_IOCMKVOL ioctl command of UBI character 47 * device. A &struct ubi_mkvol_req object has to be properly filled and a 48 * pointer to it has to be passed to the ioctl. 49 * 50 * UBI volume deletion 51 * ~~~~~~~~~~~~~~~~~~~ 52 * 53 * To delete a volume, the %UBI_IOCRMVOL ioctl command of the UBI character 54 * device should be used. A pointer to the 32-bit volume ID hast to be passed 55 * to the ioctl. 56 * 57 * UBI volume re-size 58 * ~~~~~~~~~~~~~~~~~~ 59 * 60 * To re-size a volume, the %UBI_IOCRSVOL ioctl command of the UBI character 61 * device should be used. A &struct ubi_rsvol_req object has to be properly 62 * filled and a pointer to it has to be passed to the ioctl. 63 * 64 * UBI volumes re-name 65 * ~~~~~~~~~~~~~~~~~~~ 66 * 67 * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command 68 * of the UBI character device should be used. A &struct ubi_rnvol_req object 69 * has to be properly filled and a pointer to it has to be passed to the ioctl. 70 * 71 * UBI volume update 72 * ~~~~~~~~~~~~~~~~~ 73 * 74 * Volume update should be done via the %UBI_IOCVOLUP ioctl command of the 75 * corresponding UBI volume character device. A pointer to a 64-bit update 76 * size should be passed to the ioctl. After this, UBI expects user to write 77 * this number of bytes to the volume character device. The update is finished 78 * when the claimed number of bytes is passed. So, the volume update sequence 79 * is something like: 80 * 81 * fd = open("/dev/my_volume"); 82 * ioctl(fd, UBI_IOCVOLUP, &image_size); 83 * write(fd, buf, image_size); 84 * close(fd); 85 * 86 * Logical eraseblock erase 87 * ~~~~~~~~~~~~~~~~~~~~~~~~ 88 * 89 * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the 90 * corresponding UBI volume character device should be used. This command 91 * unmaps the requested logical eraseblock, makes sure the corresponding 92 * physical eraseblock is successfully erased, and returns. 93 * 94 * Atomic logical eraseblock change 95 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 96 * 97 * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH 98 * ioctl command of the corresponding UBI volume character device. A pointer to 99 * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the 100 * user is expected to write the requested amount of bytes (similarly to what 101 * should be done in case of the "volume update" ioctl). 102 * 103 * Logical eraseblock map 104 * ~~~~~~~~~~~~~~~~~~~~~ 105 * 106 * To map a logical eraseblock to a physical eraseblock, the %UBI_IOCEBMAP 107 * ioctl command should be used. A pointer to a &struct ubi_map_req object is 108 * expected to be passed. The ioctl maps the requested logical eraseblock to 109 * a physical eraseblock and returns. Only non-mapped logical eraseblocks can 110 * be mapped. If the logical eraseblock specified in the request is already 111 * mapped to a physical eraseblock, the ioctl fails and returns error. 112 * 113 * Logical eraseblock unmap 114 * ~~~~~~~~~~~~~~~~~~~~~~~~ 115 * 116 * To unmap a logical eraseblock to a physical eraseblock, the %UBI_IOCEBUNMAP 117 * ioctl command should be used. The ioctl unmaps the logical eraseblocks, 118 * schedules corresponding physical eraseblock for erasure, and returns. Unlike 119 * the "LEB erase" command, it does not wait for the physical eraseblock being 120 * erased. Note, the side effect of this is that if an unclean reboot happens 121 * after the unmap ioctl returns, you may find the LEB mapped again to the same 122 * physical eraseblock after the UBI is run again. 123 * 124 * Check if logical eraseblock is mapped 125 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 126 * 127 * To check if a logical eraseblock is mapped to a physical eraseblock, the 128 * %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is 129 * not mapped, and %1 if it is mapped. 130 * 131 * Set an UBI volume property 132 * ~~~~~~~~~~~~~~~~~~~~~~~~~ 133 * 134 * To set an UBI volume property the %UBI_IOCSETPROP ioctl command should be 135 * used. A pointer to a &struct ubi_set_vol_prop_req object is expected to be 136 * passed. The object describes which property should be set, and to which value 137 * it should be set. 138 * 139 * Block devices on UBI volumes 140 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 141 * 142 * To create a R/O block device on top of an UBI volume the %UBI_IOCVOLCRBLK 143 * should be used. A pointer to a &struct ubi_blkcreate_req object is expected 144 * to be passed, which is not used and reserved for future usage. 145 * 146 * Conversely, to remove a block device the %UBI_IOCVOLRMBLK should be used, 147 * which takes no arguments. 148 */ 149 150 /* 151 * When a new UBI volume or UBI device is created, users may either specify the 152 * volume/device number they want to create or to let UBI automatically assign 153 * the number using these constants. 154 */ 155 #define UBI_VOL_NUM_AUTO (-1) 156 #define UBI_DEV_NUM_AUTO (-1) 157 158 /* Maximum volume name length */ 159 #define UBI_MAX_VOLUME_NAME 127 160 161 /* ioctl commands of UBI character devices */ 162 163 #define UBI_IOC_MAGIC 'o' 164 165 /* Create an UBI volume */ 166 #define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req) 167 /* Remove an UBI volume */ 168 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, __s32) 169 /* Re-size an UBI volume */ 170 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req) 171 /* Re-name volumes */ 172 #define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req) 173 174 /* Read the specified PEB and scrub it if there are bitflips */ 175 #define UBI_IOCRPEB _IOW(UBI_IOC_MAGIC, 4, __s32) 176 /* Force scrubbing on the specified PEB */ 177 #define UBI_IOCSPEB _IOW(UBI_IOC_MAGIC, 5, __s32) 178 179 /* ioctl commands of the UBI control character device */ 180 181 #define UBI_CTRL_IOC_MAGIC 'o' 182 183 /* Attach an MTD device */ 184 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req) 185 /* Detach an MTD device */ 186 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, __s32) 187 188 /* ioctl commands of UBI volume character devices */ 189 190 #define UBI_VOL_IOC_MAGIC 'O' 191 192 /* Start UBI volume update 193 * Note: This actually takes a pointer (__s64*), but we can't change 194 * that without breaking the ABI on 32bit systems 195 */ 196 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, __s64) 197 /* LEB erasure command, used for debugging, disabled by default */ 198 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, __s32) 199 /* Atomic LEB change command */ 200 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, __s32) 201 /* Map LEB command */ 202 #define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req) 203 /* Unmap LEB command */ 204 #define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, __s32) 205 /* Check if LEB is mapped command */ 206 #define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, __s32) 207 /* Set an UBI volume property */ 208 #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \ 209 struct ubi_set_vol_prop_req) 210 /* Create a R/O block device on top of an UBI volume */ 211 #define UBI_IOCVOLCRBLK _IOW(UBI_VOL_IOC_MAGIC, 7, struct ubi_blkcreate_req) 212 /* Remove the R/O block device */ 213 #define UBI_IOCVOLRMBLK _IO(UBI_VOL_IOC_MAGIC, 8) 214 215 /* Maximum MTD device name length supported by UBI */ 216 #define MAX_UBI_MTD_NAME_LEN 127 217 218 /* Maximum amount of UBI volumes that can be re-named at one go */ 219 #define UBI_MAX_RNVOL 32 220 221 /* 222 * UBI volume type constants. 223 * 224 * @UBI_DYNAMIC_VOLUME: dynamic volume 225 * @UBI_STATIC_VOLUME: static volume 226 */ 227 enum { 228 UBI_DYNAMIC_VOLUME = 3, 229 UBI_STATIC_VOLUME = 4, 230 }; 231 232 /* 233 * UBI set volume property ioctl constants. 234 * 235 * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0) 236 * user to directly write and erase individual 237 * eraseblocks on dynamic volumes 238 */ 239 enum { 240 UBI_VOL_PROP_DIRECT_WRITE = 1, 241 }; 242 243 /** 244 * struct ubi_attach_req - attach MTD device request. 245 * @ubi_num: UBI device number to create 246 * @mtd_num: MTD device number to attach 247 * @vid_hdr_offset: VID header offset (use defaults if %0) 248 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs 249 * @padding: reserved for future, not used, has to be zeroed 250 * @disable_fm: whether disable fastmap 251 * @need_resv_pool: whether reserve free pebs for filling pool/wl_pool 252 * 253 * This data structure is used to specify MTD device UBI has to attach and the 254 * parameters it has to use. The number which should be assigned to the new UBI 255 * device is passed in @ubi_num. UBI may automatically assign the number if 256 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in 257 * @ubi_num. 258 * 259 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default 260 * offset of the VID header within physical eraseblocks. The default offset is 261 * the next min. I/O unit after the EC header. For example, it will be offset 262 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or 263 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages. 264 * 265 * But in rare cases, if this optimizes things, the VID header may be placed to 266 * a different offset. For example, the boot-loader might do things faster if 267 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages. 268 * As the boot-loader would not normally need to read EC headers (unless it 269 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird 270 * example, but it real-life example. So, in this example, @vid_hdr_offer would 271 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes 272 * aligned, which is OK, as UBI is clever enough to realize this is 4th 273 * sub-page of the first page and add needed padding. 274 * 275 * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the 276 * UBI device per 1024 eraseblocks. This value is often given in an other form 277 * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The 278 * maximum expected bad eraseblocks per 1024 is then: 279 * 1024 * (1 - MinNVB / MaxNVB) 280 * Which gives 20 for most NAND devices. This limit is used in order to derive 281 * amount of eraseblock UBI reserves for handling new bad blocks. If the device 282 * has more bad eraseblocks than this limit, UBI does not reserve any physical 283 * eraseblocks for new bad eraseblocks, but attempts to use available 284 * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the 285 * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used. 286 * 287 * If @disable_fm is not zero, ubi doesn't create new fastmap even the module 288 * param 'fm_autoconvert' is set, and existed old fastmap will be destroyed 289 * after doing full scanning. 290 */ 291 struct ubi_attach_req { 292 __s32 ubi_num; 293 __s32 mtd_num; 294 __s32 vid_hdr_offset; 295 __s16 max_beb_per1024; 296 __s8 disable_fm; 297 __s8 need_resv_pool; 298 __s8 padding[8]; 299 }; 300 301 /* 302 * UBI volume flags. 303 * 304 * @UBI_VOL_SKIP_CRC_CHECK_FLG: skip the CRC check done on a static volume at 305 * open time. Only valid for static volumes and 306 * should only be used if the volume user has a 307 * way to verify data integrity 308 */ 309 enum { 310 UBI_VOL_SKIP_CRC_CHECK_FLG = 0x1, 311 }; 312 313 #define UBI_VOL_VALID_FLGS (UBI_VOL_SKIP_CRC_CHECK_FLG) 314 315 /** 316 * struct ubi_mkvol_req - volume description data structure used in 317 * volume creation requests. 318 * @vol_id: volume number 319 * @alignment: volume alignment 320 * @bytes: volume size in bytes 321 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 322 * @flags: volume flags (%UBI_VOL_SKIP_CRC_CHECK_FLG) 323 * @name_len: volume name length 324 * @padding2: reserved for future, not used, has to be zeroed 325 * @name: volume name 326 * 327 * This structure is used by user-space programs when creating new volumes. The 328 * @used_bytes field is only necessary when creating static volumes. 329 * 330 * The @alignment field specifies the required alignment of the volume logical 331 * eraseblock. This means, that the size of logical eraseblocks will be aligned 332 * to this number, i.e., 333 * (UBI device logical eraseblock size) mod (@alignment) = 0. 334 * 335 * To put it differently, the logical eraseblock of this volume may be slightly 336 * shortened in order to make it properly aligned. The alignment has to be 337 * multiple of the flash minimal input/output unit, or %1 to utilize the entire 338 * available space of logical eraseblocks. 339 * 340 * The @alignment field may be useful, for example, when one wants to maintain 341 * a block device on top of an UBI volume. In this case, it is desirable to fit 342 * an integer number of blocks in logical eraseblocks of this UBI volume. With 343 * alignment it is possible to update this volume using plane UBI volume image 344 * BLOBs, without caring about how to properly align them. 345 */ 346 struct ubi_mkvol_req { 347 __s32 vol_id; 348 __s32 alignment; 349 __s64 bytes; 350 __s8 vol_type; 351 __u8 flags; 352 __s16 name_len; 353 __s8 padding2[4]; 354 char name[UBI_MAX_VOLUME_NAME + 1]; 355 } __attribute__((packed)); 356 357 /** 358 * struct ubi_rsvol_req - a data structure used in volume re-size requests. 359 * @vol_id: ID of the volume to re-size 360 * @bytes: new size of the volume in bytes 361 * 362 * Re-sizing is possible for both dynamic and static volumes. But while dynamic 363 * volumes may be re-sized arbitrarily, static volumes cannot be made to be 364 * smaller than the number of bytes they bear. To arbitrarily shrink a static 365 * volume, it must be wiped out first (by means of volume update operation with 366 * zero number of bytes). 367 */ 368 struct ubi_rsvol_req { 369 __s64 bytes; 370 __s32 vol_id; 371 } __attribute__((packed)); 372 373 /** 374 * struct ubi_rnvol_req - volumes re-name request. 375 * @count: count of volumes to re-name 376 * @padding1: reserved for future, not used, has to be zeroed 377 * @vol_id: ID of the volume to re-name 378 * @name_len: name length 379 * @padding2: reserved for future, not used, has to be zeroed 380 * @name: new volume name 381 * 382 * UBI allows to re-name up to %32 volumes at one go. The count of volumes to 383 * re-name is specified in the @count field. The ID of the volumes to re-name 384 * and the new names are specified in the @vol_id and @name fields. 385 * 386 * The UBI volume re-name operation is atomic, which means that should power cut 387 * happen, the volumes will have either old name or new name. So the possible 388 * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes 389 * A and B one may create temporary volumes %A1 and %B1 with the new contents, 390 * then atomically re-name A1->A and B1->B, in which case old %A and %B will 391 * be removed. 392 * 393 * If it is not desirable to remove old A and B, the re-name request has to 394 * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1 395 * become A and B, and old A and B will become A1 and B1. 396 * 397 * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1 398 * and B1 become A and B, and old A and B become X and Y. 399 * 400 * In other words, in case of re-naming into an existing volume name, the 401 * existing volume is removed, unless it is re-named as well at the same 402 * re-name request. 403 */ 404 struct ubi_rnvol_req { 405 __s32 count; 406 __s8 padding1[12]; 407 struct { 408 __s32 vol_id; 409 __s16 name_len; 410 __s8 padding2[2]; 411 char name[UBI_MAX_VOLUME_NAME + 1]; 412 } ents[UBI_MAX_RNVOL]; 413 } __attribute__((packed)); 414 415 /** 416 * struct ubi_leb_change_req - a data structure used in atomic LEB change 417 * requests. 418 * @lnum: logical eraseblock number to change 419 * @bytes: how many bytes will be written to the logical eraseblock 420 * @dtype: pass "3" for better compatibility with old kernels 421 * @padding: reserved for future, not used, has to be zeroed 422 * 423 * The @dtype field used to inform UBI about what kind of data will be written 424 * to the LEB: long term (value 1), short term (value 2), unknown (value 3). 425 * UBI tried to pick a PEB with lower erase counter for short term data and a 426 * PEB with higher erase counter for long term data. But this was not really 427 * used because users usually do not know this and could easily mislead UBI. We 428 * removed this feature in May 2012. UBI currently just ignores the @dtype 429 * field. But for better compatibility with older kernels it is recommended to 430 * set @dtype to 3 (unknown). 431 */ 432 struct ubi_leb_change_req { 433 __s32 lnum; 434 __s32 bytes; 435 __s8 dtype; /* obsolete, do not use! */ 436 __s8 padding[7]; 437 } __attribute__((packed)); 438 439 /** 440 * struct ubi_map_req - a data structure used in map LEB requests. 441 * @dtype: pass "3" for better compatibility with old kernels 442 * @lnum: logical eraseblock number to unmap 443 * @padding: reserved for future, not used, has to be zeroed 444 */ 445 struct ubi_map_req { 446 __s32 lnum; 447 __s8 dtype; /* obsolete, do not use! */ 448 __s8 padding[3]; 449 } __attribute__((packed)); 450 451 452 /** 453 * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume 454 * property. 455 * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE) 456 * @padding: reserved for future, not used, has to be zeroed 457 * @value: value to set 458 */ 459 struct ubi_set_vol_prop_req { 460 __u8 property; 461 __u8 padding[7]; 462 __u64 value; 463 } __attribute__((packed)); 464 465 /** 466 * struct ubi_blkcreate_req - a data structure used in block creation requests. 467 * @padding: reserved for future, not used, has to be zeroed 468 */ 469 struct ubi_blkcreate_req { 470 __s8 padding[128]; 471 } __attribute__((packed)); 472 473 #endif /* __UBI_USER_H__ */