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 */ 138 139 /* 140 * When a new UBI volume or UBI device is created, users may either specify the 141 * volume/device number they want to create or to let UBI automatically assign 142 * the number using these constants. 143 */ 144 #define UBI_VOL_NUM_AUTO (-1) 145 #define UBI_DEV_NUM_AUTO (-1) 146 147 /* Maximum volume name length */ 148 #define UBI_MAX_VOLUME_NAME 127 149 150 /* ioctl commands of UBI character devices */ 151 152 #define UBI_IOC_MAGIC 'o' 153 154 /* Create an UBI volume */ 155 #define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req) 156 /* Remove an UBI volume */ 157 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, __s32) 158 /* Re-size an UBI volume */ 159 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req) 160 /* Re-name volumes */ 161 #define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req) 162 163 /* ioctl commands of the UBI control character device */ 164 165 #define UBI_CTRL_IOC_MAGIC 'o' 166 167 /* Attach an MTD device */ 168 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req) 169 /* Detach an MTD device */ 170 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, __s32) 171 172 /* ioctl commands of UBI volume character devices */ 173 174 #define UBI_VOL_IOC_MAGIC 'O' 175 176 /* Start UBI volume update 177 * Note: This actually takes a pointer (__s64*), but we can't change 178 * that without breaking the ABI on 32bit systems 179 */ 180 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, __s64) 181 /* LEB erasure command, used for debugging, disabled by default */ 182 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, __s32) 183 /* Atomic LEB change command */ 184 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, __s32) 185 /* Map LEB command */ 186 #define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req) 187 /* Unmap LEB command */ 188 #define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, __s32) 189 /* Check if LEB is mapped command */ 190 #define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, __s32) 191 /* Set an UBI volume property */ 192 #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \ 193 struct ubi_set_vol_prop_req) 194 195 /* Maximum MTD device name length supported by UBI */ 196 #define MAX_UBI_MTD_NAME_LEN 127 197 198 /* Maximum amount of UBI volumes that can be re-named at one go */ 199 #define UBI_MAX_RNVOL 32 200 201 /* 202 * UBI volume type constants. 203 * 204 * @UBI_DYNAMIC_VOLUME: dynamic volume 205 * @UBI_STATIC_VOLUME: static volume 206 */ 207 enum { 208 UBI_DYNAMIC_VOLUME = 3, 209 UBI_STATIC_VOLUME = 4, 210 }; 211 212 /* 213 * UBI set volume property ioctl constants. 214 * 215 * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0) 216 * user to directly write and erase individual 217 * eraseblocks on dynamic volumes 218 */ 219 enum { 220 UBI_VOL_PROP_DIRECT_WRITE = 1, 221 }; 222 223 /** 224 * struct ubi_attach_req - attach MTD device request. 225 * @ubi_num: UBI device number to create 226 * @mtd_num: MTD device number to attach 227 * @vid_hdr_offset: VID header offset (use defaults if %0) 228 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs 229 * @padding: reserved for future, not used, has to be zeroed 230 * 231 * This data structure is used to specify MTD device UBI has to attach and the 232 * parameters it has to use. The number which should be assigned to the new UBI 233 * device is passed in @ubi_num. UBI may automatically assign the number if 234 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in 235 * @ubi_num. 236 * 237 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default 238 * offset of the VID header within physical eraseblocks. The default offset is 239 * the next min. I/O unit after the EC header. For example, it will be offset 240 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or 241 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages. 242 * 243 * But in rare cases, if this optimizes things, the VID header may be placed to 244 * a different offset. For example, the boot-loader might do things faster if 245 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages. 246 * As the boot-loader would not normally need to read EC headers (unless it 247 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird 248 * example, but it real-life example. So, in this example, @vid_hdr_offer would 249 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes 250 * aligned, which is OK, as UBI is clever enough to realize this is 4th 251 * sub-page of the first page and add needed padding. 252 * 253 * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the 254 * UBI device per 1024 eraseblocks. This value is often given in an other form 255 * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The 256 * maximum expected bad eraseblocks per 1024 is then: 257 * 1024 * (1 - MinNVB / MaxNVB) 258 * Which gives 20 for most NAND devices. This limit is used in order to derive 259 * amount of eraseblock UBI reserves for handling new bad blocks. If the device 260 * has more bad eraseblocks than this limit, UBI does not reserve any physical 261 * eraseblocks for new bad eraseblocks, but attempts to use available 262 * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the 263 * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used. 264 */ 265 struct ubi_attach_req { 266 __s32 ubi_num; 267 __s32 mtd_num; 268 __s32 vid_hdr_offset; 269 __s16 max_beb_per1024; 270 __s8 padding[10]; 271 }; 272 273 /** 274 * struct ubi_mkvol_req - volume description data structure used in 275 * volume creation requests. 276 * @vol_id: volume number 277 * @alignment: volume alignment 278 * @bytes: volume size in bytes 279 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 280 * @padding1: reserved for future, not used, has to be zeroed 281 * @name_len: volume name length 282 * @padding2: reserved for future, not used, has to be zeroed 283 * @name: volume name 284 * 285 * This structure is used by user-space programs when creating new volumes. The 286 * @used_bytes field is only necessary when creating static volumes. 287 * 288 * The @alignment field specifies the required alignment of the volume logical 289 * eraseblock. This means, that the size of logical eraseblocks will be aligned 290 * to this number, i.e., 291 * (UBI device logical eraseblock size) mod (@alignment) = 0. 292 * 293 * To put it differently, the logical eraseblock of this volume may be slightly 294 * shortened in order to make it properly aligned. The alignment has to be 295 * multiple of the flash minimal input/output unit, or %1 to utilize the entire 296 * available space of logical eraseblocks. 297 * 298 * The @alignment field may be useful, for example, when one wants to maintain 299 * a block device on top of an UBI volume. In this case, it is desirable to fit 300 * an integer number of blocks in logical eraseblocks of this UBI volume. With 301 * alignment it is possible to update this volume using plane UBI volume image 302 * BLOBs, without caring about how to properly align them. 303 */ 304 struct ubi_mkvol_req { 305 __s32 vol_id; 306 __s32 alignment; 307 __s64 bytes; 308 __s8 vol_type; 309 __s8 padding1; 310 __s16 name_len; 311 __s8 padding2[4]; 312 char name[UBI_MAX_VOLUME_NAME + 1]; 313 } __packed; 314 315 /** 316 * struct ubi_rsvol_req - a data structure used in volume re-size requests. 317 * @vol_id: ID of the volume to re-size 318 * @bytes: new size of the volume in bytes 319 * 320 * Re-sizing is possible for both dynamic and static volumes. But while dynamic 321 * volumes may be re-sized arbitrarily, static volumes cannot be made to be 322 * smaller than the number of bytes they bear. To arbitrarily shrink a static 323 * volume, it must be wiped out first (by means of volume update operation with 324 * zero number of bytes). 325 */ 326 struct ubi_rsvol_req { 327 __s64 bytes; 328 __s32 vol_id; 329 } __packed; 330 331 /** 332 * struct ubi_rnvol_req - volumes re-name request. 333 * @count: count of volumes to re-name 334 * @padding1: reserved for future, not used, has to be zeroed 335 * @vol_id: ID of the volume to re-name 336 * @name_len: name length 337 * @padding2: reserved for future, not used, has to be zeroed 338 * @name: new volume name 339 * 340 * UBI allows to re-name up to %32 volumes at one go. The count of volumes to 341 * re-name is specified in the @count field. The ID of the volumes to re-name 342 * and the new names are specified in the @vol_id and @name fields. 343 * 344 * The UBI volume re-name operation is atomic, which means that should power cut 345 * happen, the volumes will have either old name or new name. So the possible 346 * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes 347 * A and B one may create temporary volumes %A1 and %B1 with the new contents, 348 * then atomically re-name A1->A and B1->B, in which case old %A and %B will 349 * be removed. 350 * 351 * If it is not desirable to remove old A and B, the re-name request has to 352 * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1 353 * become A and B, and old A and B will become A1 and B1. 354 * 355 * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1 356 * and B1 become A and B, and old A and B become X and Y. 357 * 358 * In other words, in case of re-naming into an existing volume name, the 359 * existing volume is removed, unless it is re-named as well at the same 360 * re-name request. 361 */ 362 struct ubi_rnvol_req { 363 __s32 count; 364 __s8 padding1[12]; 365 struct { 366 __s32 vol_id; 367 __s16 name_len; 368 __s8 padding2[2]; 369 char name[UBI_MAX_VOLUME_NAME + 1]; 370 } ents[UBI_MAX_RNVOL]; 371 } __packed; 372 373 /** 374 * struct ubi_leb_change_req - a data structure used in atomic LEB change 375 * requests. 376 * @lnum: logical eraseblock number to change 377 * @bytes: how many bytes will be written to the logical eraseblock 378 * @dtype: pass "3" for better compatibility with old kernels 379 * @padding: reserved for future, not used, has to be zeroed 380 * 381 * The @dtype field used to inform UBI about what kind of data will be written 382 * to the LEB: long term (value 1), short term (value 2), unknown (value 3). 383 * UBI tried to pick a PEB with lower erase counter for short term data and a 384 * PEB with higher erase counter for long term data. But this was not really 385 * used because users usually do not know this and could easily mislead UBI. We 386 * removed this feature in May 2012. UBI currently just ignores the @dtype 387 * field. But for better compatibility with older kernels it is recommended to 388 * set @dtype to 3 (unknown). 389 */ 390 struct ubi_leb_change_req { 391 __s32 lnum; 392 __s32 bytes; 393 __s8 dtype; /* obsolete, do not use! */ 394 __s8 padding[7]; 395 } __packed; 396 397 /** 398 * struct ubi_map_req - a data structure used in map LEB requests. 399 * @dtype: pass "3" for better compatibility with old kernels 400 * @lnum: logical eraseblock number to unmap 401 * @padding: reserved for future, not used, has to be zeroed 402 */ 403 struct ubi_map_req { 404 __s32 lnum; 405 __s8 dtype; /* obsolete, do not use! */ 406 __s8 padding[3]; 407 } __packed; 408 409 410 /** 411 * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume 412 * property. 413 * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE) 414 * @padding: reserved for future, not used, has to be zeroed 415 * @value: value to set 416 */ 417 struct ubi_set_vol_prop_req { 418 __u8 property; 419 __u8 padding[7]; 420 __u64 value; 421 } __packed; 422 423 #endif /* __UBI_USER_H__ */ 424