1 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
2 /*
3 * Copyright © International Business Machines Corp., 2006
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 *
19 * Author: Artem Bityutskiy (Битюцкий Артём)
20 */
21
22 #ifndef __UBI_USER_H__
23 #define __UBI_USER_H__
24
25 #include <linux/types.h>
26
27 /*
28 * UBI device creation (the same as MTD device attachment)
29 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
30 *
31 * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI
32 * control device. The caller has to properly fill and pass
33 * &struct ubi_attach_req object - UBI will attach the MTD device specified in
34 * the request and return the newly created UBI device number as the ioctl
35 * return value.
36 *
37 * UBI device deletion (the same as MTD device detachment)
38 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
39 *
40 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI
41 * control device.
42 *
43 * UBI volume creation
44 * ~~~~~~~~~~~~~~~~~~~
45 *
46 * UBI volumes are created via the %UBI_IOCMKVOL ioctl command of UBI character
47 * device. A &struct ubi_mkvol_req object has to be properly filled and a
48 * pointer to it has to be passed to the ioctl.
49 *
50 * UBI volume deletion
51 * ~~~~~~~~~~~~~~~~~~~
52 *
53 * To delete a volume, the %UBI_IOCRMVOL ioctl command of the UBI character
54 * device should be used. A pointer to the 32-bit volume ID hast to be passed
55 * to the ioctl.
56 *
57 * UBI volume re-size
58 * ~~~~~~~~~~~~~~~~~~
59 *
60 * To re-size a volume, the %UBI_IOCRSVOL ioctl command of the UBI character
61 * device should be used. A &struct ubi_rsvol_req object has to be properly
62 * filled and a pointer to it has to be passed to the ioctl.
63 *
64 * UBI volumes re-name
65 * ~~~~~~~~~~~~~~~~~~~
66 *
67 * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command
68 * of the UBI character device should be used. A &struct ubi_rnvol_req object
69 * has to be properly filled and a pointer to it has to be passed to the ioctl.
70 *
71 * UBI volume update
72 * ~~~~~~~~~~~~~~~~~
73 *
74 * Volume update should be done via the %UBI_IOCVOLUP ioctl command of the
75 * corresponding UBI volume character device. A pointer to a 64-bit update
76 * size should be passed to the ioctl. After this, UBI expects user to write
77 * this number of bytes to the volume character device. The update is finished
78 * when the claimed number of bytes is passed. So, the volume update sequence
79 * is something like:
80 *
81 * fd = open("/dev/my_volume");
82 * ioctl(fd, UBI_IOCVOLUP, &image_size);
83 * write(fd, buf, image_size);
84 * close(fd);
85 *
86 * Logical eraseblock erase
87 * ~~~~~~~~~~~~~~~~~~~~~~~~
88 *
89 * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the
90 * corresponding UBI volume character device should be used. This command
91 * unmaps the requested logical eraseblock, makes sure the corresponding
92 * physical eraseblock is successfully erased, and returns.
93 *
94 * Atomic logical eraseblock change
95 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
96 *
97 * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH
98 * ioctl command of the corresponding UBI volume character device. A pointer to
99 * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the
100 * user is expected to write the requested amount of bytes (similarly to what
101 * should be done in case of the "volume update" ioctl).
102 *
103 * Logical eraseblock map
104 * ~~~~~~~~~~~~~~~~~~~~~
105 *
106 * To map a logical eraseblock to a physical eraseblock, the %UBI_IOCEBMAP
107 * ioctl command should be used. A pointer to a &struct ubi_map_req object is
108 * expected to be passed. The ioctl maps the requested logical eraseblock to
109 * a physical eraseblock and returns. Only non-mapped logical eraseblocks can
110 * be mapped. If the logical eraseblock specified in the request is already
111 * mapped to a physical eraseblock, the ioctl fails and returns error.
112 *
113 * Logical eraseblock unmap
114 * ~~~~~~~~~~~~~~~~~~~~~~~~
115 *
116 * To unmap a logical eraseblock to a physical eraseblock, the %UBI_IOCEBUNMAP
117 * ioctl command should be used. The ioctl unmaps the logical eraseblocks,
118 * schedules corresponding physical eraseblock for erasure, and returns. Unlike
119 * the "LEB erase" command, it does not wait for the physical eraseblock being
120 * erased. Note, the side effect of this is that if an unclean reboot happens
121 * after the unmap ioctl returns, you may find the LEB mapped again to the same
122 * physical eraseblock after the UBI is run again.
123 *
124 * Check if logical eraseblock is mapped
125 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
126 *
127 * To check if a logical eraseblock is mapped to a physical eraseblock, the
128 * %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is
129 * not mapped, and %1 if it is mapped.
130 *
131 * Set an UBI volume property
132 * ~~~~~~~~~~~~~~~~~~~~~~~~~
133 *
134 * To set an UBI volume property the %UBI_IOCSETPROP ioctl command should be
135 * used. A pointer to a &struct ubi_set_vol_prop_req object is expected to be
136 * passed. The object describes which property should be set, and to which value
137 * it should be set.
138 *
139 * Block devices on UBI volumes
140 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
141 *
142 * To create a R/O block device on top of an UBI volume the %UBI_IOCVOLCRBLK
143 * should be used. A pointer to a &struct ubi_blkcreate_req object is expected
144 * to be passed, which is not used and reserved for future usage.
145 *
146 * Conversely, to remove a block device the %UBI_IOCVOLRMBLK should be used,
147 * which takes no arguments.
148 */
149
150 /*
151 * When a new UBI volume or UBI device is created, users may either specify the
152 * volume/device number they want to create or to let UBI automatically assign
153 * the number using these constants.
154 */
155 #define UBI_VOL_NUM_AUTO (-1)
156 #define UBI_DEV_NUM_AUTO (-1)
157
158 /* Maximum volume name length */
159 #define UBI_MAX_VOLUME_NAME 127
160
161 /* ioctl commands of UBI character devices */
162
163 #define UBI_IOC_MAGIC 'o'
164
165 /* Create an UBI volume */
166 #define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req)
167 /* Remove an UBI volume */
168 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, __s32)
169 /* Re-size an UBI volume */
170 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)
171 /* Re-name volumes */
172 #define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req)
173
174 /* Read the specified PEB and scrub it if there are bitflips */
175 #define UBI_IOCRPEB _IOW(UBI_IOC_MAGIC, 4, __s32)
176 /* Force scrubbing on the specified PEB */
177 #define UBI_IOCSPEB _IOW(UBI_IOC_MAGIC, 5, __s32)
178
179 /* ioctl commands of the UBI control character device */
180
181 #define UBI_CTRL_IOC_MAGIC 'o'
182
183 /* Attach an MTD device */
184 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req)
185 /* Detach an MTD device */
186 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, __s32)
187
188 /* ioctl commands of UBI volume character devices */
189
190 #define UBI_VOL_IOC_MAGIC 'O'
191
192 /* Start UBI volume update
193 * Note: This actually takes a pointer (__s64*), but we can't change
194 * that without breaking the ABI on 32bit systems
195 */
196 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, __s64)
197 /* LEB erasure command, used for debugging, disabled by default */
198 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, __s32)
199 /* Atomic LEB change command */
200 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, __s32)
201 /* Map LEB command */
202 #define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req)
203 /* Unmap LEB command */
204 #define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, __s32)
205 /* Check if LEB is mapped command */
206 #define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, __s32)
207 /* Set an UBI volume property */
208 #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \
209 struct ubi_set_vol_prop_req)
210 /* Create a R/O block device on top of an UBI volume */
211 #define UBI_IOCVOLCRBLK _IOW(UBI_VOL_IOC_MAGIC, 7, struct ubi_blkcreate_req)
212 /* Remove the R/O block device */
213 #define UBI_IOCVOLRMBLK _IO(UBI_VOL_IOC_MAGIC, 8)
214
215 /* Maximum MTD device name length supported by UBI */
216 #define MAX_UBI_MTD_NAME_LEN 127
217
218 /* Maximum amount of UBI volumes that can be re-named at one go */
219 #define UBI_MAX_RNVOL 32
220
221 /*
222 * UBI volume type constants.
223 *
224 * @UBI_DYNAMIC_VOLUME: dynamic volume
225 * @UBI_STATIC_VOLUME: static volume
226 */
227 enum {
228 UBI_DYNAMIC_VOLUME = 3,
229 UBI_STATIC_VOLUME = 4,
230 };
231
232 /*
233 * UBI set volume property ioctl constants.
234 *
235 * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0)
236 * user to directly write and erase individual
237 * eraseblocks on dynamic volumes
238 */
239 enum {
240 UBI_VOL_PROP_DIRECT_WRITE = 1,
241 };
242
243 /**
244 * struct ubi_attach_req - attach MTD device request.
245 * @ubi_num: UBI device number to create
246 * @mtd_num: MTD device number to attach
247 * @vid_hdr_offset: VID header offset (use defaults if %0)
248 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
249 * @padding: reserved for future, not used, has to be zeroed
250 *
251 * This data structure is used to specify MTD device UBI has to attach and the
252 * parameters it has to use. The number which should be assigned to the new UBI
253 * device is passed in @ubi_num. UBI may automatically assign the number if
254 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in
255 * @ubi_num.
256 *
257 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default
258 * offset of the VID header within physical eraseblocks. The default offset is
259 * the next min. I/O unit after the EC header. For example, it will be offset
260 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or
261 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages.
262 *
263 * But in rare cases, if this optimizes things, the VID header may be placed to
264 * a different offset. For example, the boot-loader might do things faster if
265 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages.
266 * As the boot-loader would not normally need to read EC headers (unless it
267 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird
268 * example, but it real-life example. So, in this example, @vid_hdr_offer would
269 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
270 * aligned, which is OK, as UBI is clever enough to realize this is 4th
271 * sub-page of the first page and add needed padding.
272 *
273 * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the
274 * UBI device per 1024 eraseblocks. This value is often given in an other form
275 * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The
276 * maximum expected bad eraseblocks per 1024 is then:
277 * 1024 * (1 - MinNVB / MaxNVB)
278 * Which gives 20 for most NAND devices. This limit is used in order to derive
279 * amount of eraseblock UBI reserves for handling new bad blocks. If the device
280 * has more bad eraseblocks than this limit, UBI does not reserve any physical
281 * eraseblocks for new bad eraseblocks, but attempts to use available
282 * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the
283 * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used.
284 */
285 struct ubi_attach_req {
286 __s32 ubi_num;
287 __s32 mtd_num;
288 __s32 vid_hdr_offset;
289 __s16 max_beb_per1024;
290 __s8 padding[10];
291 };
292
293 /*
294 * UBI volume flags.
295 *
296 * @UBI_VOL_SKIP_CRC_CHECK_FLG: skip the CRC check done on a static volume at
297 * open time. Only valid for static volumes and
298 * should only be used if the volume user has a
299 * way to verify data integrity
300 */
301 enum {
302 UBI_VOL_SKIP_CRC_CHECK_FLG = 0x1,
303 };
304
305 #define UBI_VOL_VALID_FLGS (UBI_VOL_SKIP_CRC_CHECK_FLG)
306
307 /**
308 * struct ubi_mkvol_req - volume description data structure used in
309 * volume creation requests.
310 * @vol_id: volume number
311 * @alignment: volume alignment
312 * @bytes: volume size in bytes
313 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
314 * @flags: volume flags (%UBI_VOL_SKIP_CRC_CHECK_FLG)
315 * @name_len: volume name length
316 * @padding2: reserved for future, not used, has to be zeroed
317 * @name: volume name
318 *
319 * This structure is used by user-space programs when creating new volumes. The
320 * @used_bytes field is only necessary when creating static volumes.
321 *
322 * The @alignment field specifies the required alignment of the volume logical
323 * eraseblock. This means, that the size of logical eraseblocks will be aligned
324 * to this number, i.e.,
325 * (UBI device logical eraseblock size) mod (@alignment) = 0.
326 *
327 * To put it differently, the logical eraseblock of this volume may be slightly
328 * shortened in order to make it properly aligned. The alignment has to be
329 * multiple of the flash minimal input/output unit, or %1 to utilize the entire
330 * available space of logical eraseblocks.
331 *
332 * The @alignment field may be useful, for example, when one wants to maintain
333 * a block device on top of an UBI volume. In this case, it is desirable to fit
334 * an integer number of blocks in logical eraseblocks of this UBI volume. With
335 * alignment it is possible to update this volume using plane UBI volume image
336 * BLOBs, without caring about how to properly align them.
337 */
338 struct ubi_mkvol_req {
339 __s32 vol_id;
340 __s32 alignment;
341 __s64 bytes;
342 __s8 vol_type;
343 __u8 flags;
344 __s16 name_len;
345 __s8 padding2[4];
346 char name[UBI_MAX_VOLUME_NAME + 1];
347 } __packed;
348
349 /**
350 * struct ubi_rsvol_req - a data structure used in volume re-size requests.
351 * @vol_id: ID of the volume to re-size
352 * @bytes: new size of the volume in bytes
353 *
354 * Re-sizing is possible for both dynamic and static volumes. But while dynamic
355 * volumes may be re-sized arbitrarily, static volumes cannot be made to be
356 * smaller than the number of bytes they bear. To arbitrarily shrink a static
357 * volume, it must be wiped out first (by means of volume update operation with
358 * zero number of bytes).
359 */
360 struct ubi_rsvol_req {
361 __s64 bytes;
362 __s32 vol_id;
363 } __packed;
364
365 /**
366 * struct ubi_rnvol_req - volumes re-name request.
367 * @count: count of volumes to re-name
368 * @padding1: reserved for future, not used, has to be zeroed
369 * @vol_id: ID of the volume to re-name
370 * @name_len: name length
371 * @padding2: reserved for future, not used, has to be zeroed
372 * @name: new volume name
373 *
374 * UBI allows to re-name up to %32 volumes at one go. The count of volumes to
375 * re-name is specified in the @count field. The ID of the volumes to re-name
376 * and the new names are specified in the @vol_id and @name fields.
377 *
378 * The UBI volume re-name operation is atomic, which means that should power cut
379 * happen, the volumes will have either old name or new name. So the possible
380 * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes
381 * A and B one may create temporary volumes %A1 and %B1 with the new contents,
382 * then atomically re-name A1->A and B1->B, in which case old %A and %B will
383 * be removed.
384 *
385 * If it is not desirable to remove old A and B, the re-name request has to
386 * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1
387 * become A and B, and old A and B will become A1 and B1.
388 *
389 * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1
390 * and B1 become A and B, and old A and B become X and Y.
391 *
392 * In other words, in case of re-naming into an existing volume name, the
393 * existing volume is removed, unless it is re-named as well at the same
394 * re-name request.
395 */
396 struct ubi_rnvol_req {
397 __s32 count;
398 __s8 padding1[12];
399 struct {
400 __s32 vol_id;
401 __s16 name_len;
402 __s8 padding2[2];
403 char name[UBI_MAX_VOLUME_NAME + 1];
404 } ents[UBI_MAX_RNVOL];
405 } __packed;
406
407 /**
408 * struct ubi_leb_change_req - a data structure used in atomic LEB change
409 * requests.
410 * @lnum: logical eraseblock number to change
411 * @bytes: how many bytes will be written to the logical eraseblock
412 * @dtype: pass "3" for better compatibility with old kernels
413 * @padding: reserved for future, not used, has to be zeroed
414 *
415 * The @dtype field used to inform UBI about what kind of data will be written
416 * to the LEB: long term (value 1), short term (value 2), unknown (value 3).
417 * UBI tried to pick a PEB with lower erase counter for short term data and a
418 * PEB with higher erase counter for long term data. But this was not really
419 * used because users usually do not know this and could easily mislead UBI. We
420 * removed this feature in May 2012. UBI currently just ignores the @dtype
421 * field. But for better compatibility with older kernels it is recommended to
422 * set @dtype to 3 (unknown).
423 */
424 struct ubi_leb_change_req {
425 __s32 lnum;
426 __s32 bytes;
427 __s8 dtype; /* obsolete, do not use! */
428 __s8 padding[7];
429 } __packed;
430
431 /**
432 * struct ubi_map_req - a data structure used in map LEB requests.
433 * @dtype: pass "3" for better compatibility with old kernels
434 * @lnum: logical eraseblock number to unmap
435 * @padding: reserved for future, not used, has to be zeroed
436 */
437 struct ubi_map_req {
438 __s32 lnum;
439 __s8 dtype; /* obsolete, do not use! */
440 __s8 padding[3];
441 } __packed;
442
443
444 /**
445 * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume
446 * property.
447 * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE)
448 * @padding: reserved for future, not used, has to be zeroed
449 * @value: value to set
450 */
451 struct ubi_set_vol_prop_req {
452 __u8 property;
453 __u8 padding[7];
454 __u64 value;
455 } __packed;
456
457 /**
458 * struct ubi_blkcreate_req - a data structure used in block creation requests.
459 * @padding: reserved for future, not used, has to be zeroed
460 */
461 struct ubi_blkcreate_req {
462 __s8 padding[128];
463 } __packed;
464
465 #endif /* __UBI_USER_H__ */