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