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 ( ) 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 /* ioctl commands of the UBI control character device */ 175 176 #define UBI_CTRL_IOC_MAGIC 'o' 177 178 /* Attach an MTD device */ 179 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req) 180 /* Detach an MTD device */ 181 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, __s32) 182 183 /* ioctl commands of UBI volume character devices */ 184 185 #define UBI_VOL_IOC_MAGIC 'O' 186 187 /* Start UBI volume update 188 * Note: This actually takes a pointer (__s64*), but we can't change 189 * that without breaking the ABI on 32bit systems 190 */ 191 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, __s64) 192 /* LEB erasure command, used for debugging, disabled by default */ 193 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, __s32) 194 /* Atomic LEB change command */ 195 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, __s32) 196 /* Map LEB command */ 197 #define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req) 198 /* Unmap LEB command */ 199 #define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, __s32) 200 /* Check if LEB is mapped command */ 201 #define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, __s32) 202 /* Set an UBI volume property */ 203 #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \ 204 struct ubi_set_vol_prop_req) 205 /* Create a R/O block device on top of an UBI volume */ 206 #define UBI_IOCVOLCRBLK _IOW(UBI_VOL_IOC_MAGIC, 7, struct ubi_blkcreate_req) 207 /* Remove the R/O block device */ 208 #define UBI_IOCVOLRMBLK _IO(UBI_VOL_IOC_MAGIC, 8) 209 210 /* Maximum MTD device name length supported by UBI */ 211 #define MAX_UBI_MTD_NAME_LEN 127 212 213 /* Maximum amount of UBI volumes that can be re-named at one go */ 214 #define UBI_MAX_RNVOL 32 215 216 /* 217 * UBI volume type constants. 218 * 219 * @UBI_DYNAMIC_VOLUME: dynamic volume 220 * @UBI_STATIC_VOLUME: static volume 221 */ 222 enum { 223 UBI_DYNAMIC_VOLUME = 3, 224 UBI_STATIC_VOLUME = 4, 225 }; 226 227 /* 228 * UBI set volume property ioctl constants. 229 * 230 * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0) 231 * user to directly write and erase individual 232 * eraseblocks on dynamic volumes 233 */ 234 enum { 235 UBI_VOL_PROP_DIRECT_WRITE = 1, 236 }; 237 238 /** 239 * struct ubi_attach_req - attach MTD device request. 240 * @ubi_num: UBI device number to create 241 * @mtd_num: MTD device number to attach 242 * @vid_hdr_offset: VID header offset (use defaults if %0) 243 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs 244 * @padding: reserved for future, not used, has to be zeroed 245 * 246 * This data structure is used to specify MTD device UBI has to attach and the 247 * parameters it has to use. The number which should be assigned to the new UBI 248 * device is passed in @ubi_num. UBI may automatically assign the number if 249 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in 250 * @ubi_num. 251 * 252 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default 253 * offset of the VID header within physical eraseblocks. The default offset is 254 * the next min. I/O unit after the EC header. For example, it will be offset 255 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or 256 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages. 257 * 258 * But in rare cases, if this optimizes things, the VID header may be placed to 259 * a different offset. For example, the boot-loader might do things faster if 260 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages. 261 * As the boot-loader would not normally need to read EC headers (unless it 262 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird 263 * example, but it real-life example. So, in this example, @vid_hdr_offer would 264 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes 265 * aligned, which is OK, as UBI is clever enough to realize this is 4th 266 * sub-page of the first page and add needed padding. 267 * 268 * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the 269 * UBI device per 1024 eraseblocks. This value is often given in an other form 270 * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The 271 * maximum expected bad eraseblocks per 1024 is then: 272 * 1024 * (1 - MinNVB / MaxNVB) 273 * Which gives 20 for most NAND devices. This limit is used in order to derive 274 * amount of eraseblock UBI reserves for handling new bad blocks. If the device 275 * has more bad eraseblocks than this limit, UBI does not reserve any physical 276 * eraseblocks for new bad eraseblocks, but attempts to use available 277 * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the 278 * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used. 279 */ 280 struct ubi_attach_req { 281 __s32 ubi_num; 282 __s32 mtd_num; 283 __s32 vid_hdr_offset; 284 __s16 max_beb_per1024; 285 __s8 padding[10]; 286 }; 287 288 /** 289 * struct ubi_mkvol_req - volume description data structure used in 290 * volume creation requests. 291 * @vol_id: volume number 292 * @alignment: volume alignment 293 * @bytes: volume size in bytes 294 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 295 * @padding1: reserved for future, not used, has to be zeroed 296 * @name_len: volume name length 297 * @padding2: reserved for future, not used, has to be zeroed 298 * @name: volume name 299 * 300 * This structure is used by user-space programs when creating new volumes. The 301 * @used_bytes field is only necessary when creating static volumes. 302 * 303 * The @alignment field specifies the required alignment of the volume logical 304 * eraseblock. This means, that the size of logical eraseblocks will be aligned 305 * to this number, i.e., 306 * (UBI device logical eraseblock size) mod (@alignment) = 0. 307 * 308 * To put it differently, the logical eraseblock of this volume may be slightly 309 * shortened in order to make it properly aligned. The alignment has to be 310 * multiple of the flash minimal input/output unit, or %1 to utilize the entire 311 * available space of logical eraseblocks. 312 * 313 * The @alignment field may be useful, for example, when one wants to maintain 314 * a block device on top of an UBI volume. In this case, it is desirable to fit 315 * an integer number of blocks in logical eraseblocks of this UBI volume. With 316 * alignment it is possible to update this volume using plane UBI volume image 317 * BLOBs, without caring about how to properly align them. 318 */ 319 struct ubi_mkvol_req { 320 __s32 vol_id; 321 __s32 alignment; 322 __s64 bytes; 323 __s8 vol_type; 324 __s8 padding1; 325 __s16 name_len; 326 __s8 padding2[4]; 327 char name[UBI_MAX_VOLUME_NAME + 1]; 328 } __packed; 329 330 /** 331 * struct ubi_rsvol_req - a data structure used in volume re-size requests. 332 * @vol_id: ID of the volume to re-size 333 * @bytes: new size of the volume in bytes 334 * 335 * Re-sizing is possible for both dynamic and static volumes. But while dynamic 336 * volumes may be re-sized arbitrarily, static volumes cannot be made to be 337 * smaller than the number of bytes they bear. To arbitrarily shrink a static 338 * volume, it must be wiped out first (by means of volume update operation with 339 * zero number of bytes). 340 */ 341 struct ubi_rsvol_req { 342 __s64 bytes; 343 __s32 vol_id; 344 } __packed; 345 346 /** 347 * struct ubi_rnvol_req - volumes re-name request. 348 * @count: count of volumes to re-name 349 * @padding1: reserved for future, not used, has to be zeroed 350 * @vol_id: ID of the volume to re-name 351 * @name_len: name length 352 * @padding2: reserved for future, not used, has to be zeroed 353 * @name: new volume name 354 * 355 * UBI allows to re-name up to %32 volumes at one go. The count of volumes to 356 * re-name is specified in the @count field. The ID of the volumes to re-name 357 * and the new names are specified in the @vol_id and @name fields. 358 * 359 * The UBI volume re-name operation is atomic, which means that should power cut 360 * happen, the volumes will have either old name or new name. So the possible 361 * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes 362 * A and B one may create temporary volumes %A1 and %B1 with the new contents, 363 * then atomically re-name A1->A and B1->B, in which case old %A and %B will 364 * be removed. 365 * 366 * If it is not desirable to remove old A and B, the re-name request has to 367 * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1 368 * become A and B, and old A and B will become A1 and B1. 369 * 370 * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1 371 * and B1 become A and B, and old A and B become X and Y. 372 * 373 * In other words, in case of re-naming into an existing volume name, the 374 * existing volume is removed, unless it is re-named as well at the same 375 * re-name request. 376 */ 377 struct ubi_rnvol_req { 378 __s32 count; 379 __s8 padding1[12]; 380 struct { 381 __s32 vol_id; 382 __s16 name_len; 383 __s8 padding2[2]; 384 char name[UBI_MAX_VOLUME_NAME + 1]; 385 } ents[UBI_MAX_RNVOL]; 386 } __packed; 387 388 /** 389 * struct ubi_leb_change_req - a data structure used in atomic LEB change 390 * requests. 391 * @lnum: logical eraseblock number to change 392 * @bytes: how many bytes will be written to the logical eraseblock 393 * @dtype: pass "3" for better compatibility with old kernels 394 * @padding: reserved for future, not used, has to be zeroed 395 * 396 * The @dtype field used to inform UBI about what kind of data will be written 397 * to the LEB: long term (value 1), short term (value 2), unknown (value 3). 398 * UBI tried to pick a PEB with lower erase counter for short term data and a 399 * PEB with higher erase counter for long term data. But this was not really 400 * used because users usually do not know this and could easily mislead UBI. We 401 * removed this feature in May 2012. UBI currently just ignores the @dtype 402 * field. But for better compatibility with older kernels it is recommended to 403 * set @dtype to 3 (unknown). 404 */ 405 struct ubi_leb_change_req { 406 __s32 lnum; 407 __s32 bytes; 408 __s8 dtype; /* obsolete, do not use! */ 409 __s8 padding[7]; 410 } __packed; 411 412 /** 413 * struct ubi_map_req - a data structure used in map LEB requests. 414 * @dtype: pass "3" for better compatibility with old kernels 415 * @lnum: logical eraseblock number to unmap 416 * @padding: reserved for future, not used, has to be zeroed 417 */ 418 struct ubi_map_req { 419 __s32 lnum; 420 __s8 dtype; /* obsolete, do not use! */ 421 __s8 padding[3]; 422 } __packed; 423 424 425 /** 426 * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume 427 * property. 428 * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE) 429 * @padding: reserved for future, not used, has to be zeroed 430 * @value: value to set 431 */ 432 struct ubi_set_vol_prop_req { 433 __u8 property; 434 __u8 padding[7]; 435 __u64 value; 436 } __packed; 437 438 /** 439 * struct ubi_blkcreate_req - a data structure used in block creation requests. 440 * @padding: reserved for future, not used, has to be zeroed 441 */ 442 struct ubi_blkcreate_req { 443 __s8 padding[128]; 444 } __packed; 445 446 #endif /* __UBI_USER_H__ */ 447
