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