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