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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 data type hint constants.
200 *
201 * UBI_LONGTERM: long-term data
202 * UBI_SHORTTERM: short-term data
203 * UBI_UNKNOWN: data persistence is unknown
204 *
205 * These constants are used when data is written to UBI volumes in order to
206 * help the UBI wear-leveling unit to find more appropriate physical
207 * eraseblocks.
208 */
209enum {
210 UBI_LONGTERM = 1,
211 UBI_SHORTTERM = 2,
212 UBI_UNKNOWN = 3,
213};
214
215/*
216 * UBI volume type constants.
217 *
218 * @UBI_DYNAMIC_VOLUME: dynamic volume
219 * @UBI_STATIC_VOLUME: static volume
220 */
221enum {
222 UBI_DYNAMIC_VOLUME = 3,
223 UBI_STATIC_VOLUME = 4,
224};
225
226/*
227 * UBI set volume property ioctl constants.
228 *
229 * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0)
230 * user to directly write and erase individual
231 * eraseblocks on dynamic volumes
232 */
233enum {
234 UBI_VOL_PROP_DIRECT_WRITE = 1,
235};
236
237/**
238 * struct ubi_attach_req - attach MTD device request.
239 * @ubi_num: UBI device number to create
240 * @mtd_num: MTD device number to attach
241 * @vid_hdr_offset: VID header offset (use defaults if %0)
242 * @padding: reserved for future, not used, has to be zeroed
243 *
244 * This data structure is used to specify MTD device UBI has to attach and the
245 * parameters it has to use. The number which should be assigned to the new UBI
246 * device is passed in @ubi_num. UBI may automatically assign the number if
247 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in
248 * @ubi_num.
249 *
250 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default
251 * offset of the VID header within physical eraseblocks. The default offset is
252 * the next min. I/O unit after the EC header. For example, it will be offset
253 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or
254 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages.
255 *
256 * But in rare cases, if this optimizes things, the VID header may be placed to
257 * a different offset. For example, the boot-loader might do things faster if
258 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages.
259 * As the boot-loader would not normally need to read EC headers (unless it
260 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird
261 * example, but it real-life example. So, in this example, @vid_hdr_offer would
262 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
263 * aligned, which is OK, as UBI is clever enough to realize this is 4th
264 * sub-page of the first page and add needed padding.
265 */
266struct ubi_attach_req {
267 __s32 ubi_num;
268 __s32 mtd_num;
269 __s32 vid_hdr_offset;
270 __s8 padding[12];
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 */
304struct 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 */
326struct 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 */
362struct 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: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
379 * @padding: reserved for future, not used, has to be zeroed
380 */
381struct ubi_leb_change_req {
382 __s32 lnum;
383 __s32 bytes;
384 __s8 dtype;
385 __s8 padding[7];
386} __packed;
387
388/**
389 * struct ubi_map_req - a data structure used in map LEB requests.
390 * @lnum: logical eraseblock number to unmap
391 * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
392 * @padding: reserved for future, not used, has to be zeroed
393 */
394struct ubi_map_req {
395 __s32 lnum;
396 __s8 dtype;
397 __s8 padding[3];
398} __packed;
399
400
401/**
402 * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume
403 * property.
404 * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE)
405 * @padding: reserved for future, not used, has to be zeroed
406 * @value: value to set
407 */
408struct ubi_set_vol_prop_req {
409 __u8 property;
410 __u8 padding[7];
411 __u64 value;
412} __packed;
413
414#endif /* __UBI_USER_H__ */