1 /* 2 * Copyright © International Business Machines Corp., 2006 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See 12 * the GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 * 18 * Author: Artem Bityutskiy (Битюцкий Артём) 19 */ 20 21 #ifndef __UBI_USER_H__ 22 #define __UBI_USER_H__ 23 24 /* 25 * UBI device creation (the same as MTD device attachment) 26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 27 * 28 * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI 29 * control device. The caller has to properly fill and pass 30 * &struct ubi_attach_req object - UBI will attach the MTD device specified in 31 * the request and return the newly created UBI device number as the ioctl 32 * return value. 33 * 34 * UBI device deletion (the same as MTD device detachment) 35 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 36 * 37 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI 38 * control device. 39 * 40 * UBI volume creation 41 * ~~~~~~~~~~~~~~~~~~~ 42 * 43 * UBI volumes are created via the %UBI_IOCMKVOL ioctl command of UBI character 44 * device. A &struct ubi_mkvol_req object has to be properly filled and a 45 * pointer to it has to be passed to the ioctl. 46 * 47 * UBI volume deletion 48 * ~~~~~~~~~~~~~~~~~~~ 49 * 50 * To delete a volume, the %UBI_IOCRMVOL ioctl command of the UBI character 51 * device should be used. A pointer to the 32-bit volume ID hast to be passed 52 * to the ioctl. 53 * 54 * UBI volume re-size 55 * ~~~~~~~~~~~~~~~~~~ 56 * 57 * To re-size a volume, the %UBI_IOCRSVOL ioctl command of the UBI character 58 * device should be used. A &struct ubi_rsvol_req object has to be properly 59 * filled and a pointer to it has to be passed to the ioctl. 60 * 61 * UBI volumes re-name 62 * ~~~~~~~~~~~~~~~~~~~ 63 * 64 * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command 65 * of the UBI character device should be used. A &struct ubi_rnvol_req object 66 * has to be properly filled and a pointer to it has to be passed to the ioctl. 67 * 68 * UBI volume update 69 * ~~~~~~~~~~~~~~~~~ 70 * 71 * Volume update should be done via the %UBI_IOCVOLUP ioctl command of the 72 * corresponding UBI volume character device. A pointer to a 64-bit update 73 * size should be passed to the ioctl. After this, UBI expects user to write 74 * this number of bytes to the volume character device. The update is finished 75 * when the claimed number of bytes is passed. So, the volume update sequence 76 * is something like: 77 * 78 * fd = open("/dev/my_volume"); 79 * ioctl(fd, UBI_IOCVOLUP, &image_size); 80 * write(fd, buf, image_size); 81 * close(fd); 82 * 83 * Logical eraseblock erase 84 * ~~~~~~~~~~~~~~~~~~~~~~~~ 85 * 86 * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the 87 * corresponding UBI volume character device should be used. This command 88 * unmaps the requested logical eraseblock, makes sure the corresponding 89 * physical eraseblock is successfully erased, and returns. 90 * 91 * Atomic logical eraseblock change 92 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 93 * 94 * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH 95 * ioctl command of the corresponding UBI volume character device. A pointer to 96 * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the 97 * user is expected to write the requested amount of bytes (similarly to what 98 * should be done in case of the "volume update" ioctl). 99 * 100 * Logical eraseblock map 101 * ~~~~~~~~~~~~~~~~~~~~~ 102 * 103 * To map a logical eraseblock to a physical eraseblock, the %UBI_IOCEBMAP 104 * ioctl command should be used. A pointer to a &struct ubi_map_req object is 105 * expected to be passed. The ioctl maps the requested logical eraseblock to 106 * a physical eraseblock and returns. Only non-mapped logical eraseblocks can 107 * be mapped. If the logical eraseblock specified in the request is already 108 * mapped to a physical eraseblock, the ioctl fails and returns error. 109 * 110 * Logical eraseblock unmap 111 * ~~~~~~~~~~~~~~~~~~~~~~~~ 112 * 113 * To unmap a logical eraseblock to a physical eraseblock, the %UBI_IOCEBUNMAP 114 * ioctl command should be used. The ioctl unmaps the logical eraseblocks, 115 * schedules corresponding physical eraseblock for erasure, and returns. Unlike 116 * the "LEB erase" command, it does not wait for the physical eraseblock being 117 * erased. Note, the side effect of this is that if an unclean reboot happens 118 * after the unmap ioctl returns, you may find the LEB mapped again to the same 119 * physical eraseblock after the UBI is run again. 120 * 121 * Check if logical eraseblock is mapped 122 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 123 * 124 * To check if a logical eraseblock is mapped to a physical eraseblock, the 125 * %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is 126 * not mapped, and %1 if it is mapped. 127 * 128 * Set an UBI volume property 129 * ~~~~~~~~~~~~~~~~~~~~~~~~~ 130 * 131 * To set an UBI volume property the %UBI_IOCSETPROP ioctl command should be 132 * used. A pointer to a &struct ubi_set_vol_prop_req object is expected to be 133 * passed. The object describes which property should be set, and to which value 134 * it should be set. 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, int32_t) 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, int32_t) 169 #define UBI_IOCFDET _IOW(UBI_CTRL_IOC_MAGIC, 99, int32_t) 170 171 /* ioctl commands of UBI volume character devices */ 172 173 #define UBI_VOL_IOC_MAGIC 'O' 174 175 /* Start UBI volume update */ 176 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t) 177 /* LEB erasure command, used for debugging, disabled by default */ 178 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t) 179 /* Atomic LEB change command */ 180 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, int32_t) 181 /* Map LEB command */ 182 #define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req) 183 /* Unmap LEB command */ 184 #define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, int32_t) 185 /* Check if LEB is mapped command */ 186 #define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, int32_t) 187 /* Set an UBI volume property */ 188 #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \ 189 struct ubi_set_vol_prop_req) 190 191 /* Maximum MTD device name length supported by UBI */ 192 #define MAX_UBI_MTD_NAME_LEN 127 193 194 /* Maximum amount of UBI volumes that can be re-named at one go */ 195 #define UBI_MAX_RNVOL 32 196 197 /* 198 * UBI volume type constants. 199 * 200 * @UBI_DYNAMIC_VOLUME: dynamic volume 201 * @UBI_STATIC_VOLUME: static volume 202 */ 203 enum { 204 UBI_DYNAMIC_VOLUME = 3, 205 UBI_STATIC_VOLUME = 4, 206 }; 207 208 /* 209 * UBI set volume property ioctl constants. 210 * 211 * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0) 212 * user to directly write and erase individual 213 * eraseblocks on dynamic volumes 214 */ 215 enum { 216 UBI_VOL_PROP_DIRECT_WRITE = 1, 217 }; 218 219 /** 220 * struct ubi_attach_req - attach MTD device request. 221 * @ubi_num: UBI device number to create 222 * @mtd_num: MTD device number to attach 223 * @vid_hdr_offset: VID header offset (use defaults if %0) 224 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs 225 * @padding: reserved for future, not used, has to be zeroed 226 * 227 * This data structure is used to specify MTD device UBI has to attach and the 228 * parameters it has to use. The number which should be assigned to the new UBI 229 * device is passed in @ubi_num. UBI may automatically assign the number if 230 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in 231 * @ubi_num. 232 * 233 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default 234 * offset of the VID header within physical eraseblocks. The default offset is 235 * the next min. I/O unit after the EC header. For example, it will be offset 236 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or 237 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages. 238 * 239 * But in rare cases, if this optimizes things, the VID header may be placed to 240 * a different offset. For example, the boot-loader might do things faster if 241 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages. 242 * As the boot-loader would not normally need to read EC headers (unless it 243 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird 244 * example, but it real-life example. So, in this example, @vid_hdr_offer would 245 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes 246 * aligned, which is OK, as UBI is clever enough to realize this is 4th 247 * sub-page of the first page and add needed padding. 248 * 249 * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the 250 * UBI device per 1024 eraseblocks. This value is often given in an other form 251 * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The 252 * maximum expected bad eraseblocks per 1024 is then: 253 * 1024 * (1 - MinNVB / MaxNVB) 254 * Which gives 20 for most NAND devices. This limit is used in order to derive 255 * amount of eraseblock UBI reserves for handling new bad blocks. If the device 256 * has more bad eraseblocks than this limit, UBI does not reserve any physical 257 * eraseblocks for new bad eraseblocks, but attempts to use available 258 * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the 259 * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used. 260 */ 261 struct ubi_attach_req { 262 int32_t ubi_num; 263 int32_t mtd_num; 264 int32_t vid_hdr_offset; 265 int16_t max_beb_per1024; 266 int8_t padding[10]; 267 }; 268 269 /** 270 * struct ubi_mkvol_req - volume description data structure used in 271 * volume creation requests. 272 * @vol_id: volume number 273 * @alignment: volume alignment 274 * @bytes: volume size in bytes 275 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 276 * @padding1: reserved for future, not used, has to be zeroed 277 * @name_len: volume name length 278 * @padding2: reserved for future, not used, has to be zeroed 279 * @name: volume name 280 * 281 * This structure is used by user-space programs when creating new volumes. The 282 * @used_bytes field is only necessary when creating static volumes. 283 * 284 * The @alignment field specifies the required alignment of the volume logical 285 * eraseblock. This means, that the size of logical eraseblocks will be aligned 286 * to this number, i.e., 287 * (UBI device logical eraseblock size) mod (@alignment) = 0. 288 * 289 * To put it differently, the logical eraseblock of this volume may be slightly 290 * shortened in order to make it properly aligned. The alignment has to be 291 * multiple of the flash minimal input/output unit, or %1 to utilize the entire 292 * available space of logical eraseblocks. 293 * 294 * The @alignment field may be useful, for example, when one wants to maintain 295 * a block device on top of an UBI volume. In this case, it is desirable to fit 296 * an integer number of blocks in logical eraseblocks of this UBI volume. With 297 * alignment it is possible to update this volume using plane UBI volume image 298 * BLOBs, without caring about how to properly align them. 299 */ 300 struct ubi_mkvol_req { 301 int32_t vol_id; 302 int32_t alignment; 303 int64_t bytes; 304 int8_t vol_type; 305 int8_t padding1; 306 int16_t name_len; 307 int8_t padding2[4]; 308 char name[UBI_MAX_VOLUME_NAME + 1]; 309 } __attribute__((packed)); 310 311 /** 312 * struct ubi_rsvol_req - a data structure used in volume re-size requests. 313 * @vol_id: ID of the volume to re-size 314 * @bytes: new size of the volume in bytes 315 * 316 * Re-sizing is possible for both dynamic and static volumes. But while dynamic 317 * volumes may be re-sized arbitrarily, static volumes cannot be made to be 318 * smaller than the number of bytes they bear. To arbitrarily shrink a static 319 * volume, it must be wiped out first (by means of volume update operation with 320 * zero number of bytes). 321 */ 322 struct ubi_rsvol_req { 323 int64_t bytes; 324 int32_t vol_id; 325 } __attribute__((packed)); 326 327 /** 328 * struct ubi_rnvol_req - volumes re-name request. 329 * @count: count of volumes to re-name 330 * @padding1: reserved for future, not used, has to be zeroed 331 * @vol_id: ID of the volume to re-name 332 * @name_len: name length 333 * @padding2: reserved for future, not used, has to be zeroed 334 * @name: new volume name 335 * 336 * UBI allows to re-name up to %32 volumes at one go. The count of volumes to 337 * re-name is specified in the @count field. The ID of the volumes to re-name 338 * and the new names are specified in the @vol_id and @name fields. 339 * 340 * The UBI volume re-name operation is atomic, which means that should power cut 341 * happen, the volumes will have either old name or new name. So the possible 342 * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes 343 * A and B one may create temporary volumes %A1 and %B1 with the new contents, 344 * then atomically re-name A1->A and B1->B, in which case old %A and %B will 345 * be removed. 346 * 347 * If it is not desirable to remove old A and B, the re-name request has to 348 * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1 349 * become A and B, and old A and B will become A1 and B1. 350 * 351 * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1 352 * and B1 become A and B, and old A and B become X and Y. 353 * 354 * In other words, in case of re-naming into an existing volume name, the 355 * existing volume is removed, unless it is re-named as well at the same 356 * re-name request. 357 */ 358 struct ubi_rnvol_req { 359 int32_t count; 360 int8_t padding1[12]; 361 struct { 362 int32_t vol_id; 363 int16_t name_len; 364 int8_t padding2[2]; 365 char name[UBI_MAX_VOLUME_NAME + 1]; 366 } ents[UBI_MAX_RNVOL]; 367 } __attribute__((packed)); 368 369 /** 370 * struct ubi_leb_change_req - a data structure used in atomic LEB change 371 * requests. 372 * @lnum: logical eraseblock number to change 373 * @bytes: how many bytes will be written to the logical eraseblock 374 * @dtype: pass "3" for better compatibility with old kernels 375 * @padding: reserved for future, not used, has to be zeroed 376 * 377 * The @dtype field used to inform UBI about what kind of data will be written 378 * to the LEB: long term (value 1), short term (value 2), unknown (value 3). 379 * UBI tried to pick a PEB with lower erase counter for short term data and a 380 * PEB with higher erase counter for long term data. But this was not really 381 * used because users usually do not know this and could easily mislead UBI. We 382 * removed this feature in May 2012. UBI currently just ignores the @dtype 383 * field. But for better compatibility with older kernels it is recommended to 384 * set @dtype to 3 (unknown). 385 */ 386 struct ubi_leb_change_req { 387 int32_t lnum; 388 int32_t bytes; 389 int8_t dtype; /* obsolete, do not use! */ 390 int8_t padding[7]; 391 } __attribute__((packed)); 392 393 /** 394 * struct ubi_map_req - a data structure used in map LEB requests. 395 * @dtype: pass "3" for better compatibility with old kernels 396 * @lnum: logical eraseblock number to unmap 397 * @padding: reserved for future, not used, has to be zeroed 398 */ 399 struct ubi_map_req { 400 int32_t lnum; 401 int8_t dtype; /* obsolete, do not use! */ 402 int8_t padding[3]; 403 } __attribute__((packed)); 404 405 406 /** 407 * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume 408 * property. 409 * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE) 410 * @padding: reserved for future, not used, has to be zeroed 411 * @value: value to set 412 */ 413 struct ubi_set_vol_prop_req { 414 uint8_t property; 415 uint8_t padding[7]; 416 uint64_t value; 417 } __attribute__((packed)); 418 419 #endif /* __UBI_USER_H__ */ 420
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