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001: /*
002:  * Copyright © International Business Machines Corp., 2006
003:  *
004:  * This program is free software; you can redistribute it and/or modify
005:  * it under the terms of the GNU General Public License as published by
006:  * the Free Software Foundation; either version 2 of the License, or
007:  * (at your option) any later version.
008:  *
009:  * This program is distributed in the hope that it will be useful,
010:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
011:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
012:  * the GNU General Public License for more details.
013:  *
014:  * You should have received a copy of the GNU General Public License
015:  * along with this program; if not, write to the Free Software
016:  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
017:  *
018:  * Author: Artem Bityutskiy (Битюцкий Артём)
019:  */
020: 
021: #ifndef __UBI_USER_H__
022: #define __UBI_USER_H__
023: 
024: #include <linux/types.h>
025: 
026: /*
027:  * UBI device creation (the same as MTD device attachment)
028:  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
029:  *
030:  * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI
031:  * control device. The caller has to properly fill and pass
032:  * &struct ubi_attach_req object - UBI will attach the MTD device specified in
033:  * the request and return the newly created UBI device number as the ioctl
034:  * return value.
035:  *
036:  * UBI device deletion (the same as MTD device detachment)
037:  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
038:  *
039:  * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI
040:  * control device.
041:  *
042:  * UBI volume creation
043:  * ~~~~~~~~~~~~~~~~~~~
044:  *
045:  * UBI volumes are created via the %UBI_IOCMKVOL ioctl command of UBI character
046:  * device. A &struct ubi_mkvol_req object has to be properly filled and a
047:  * pointer to it has to be passed to the ioctl.
048:  *
049:  * UBI volume deletion
050:  * ~~~~~~~~~~~~~~~~~~~
051:  *
052:  * To delete a volume, the %UBI_IOCRMVOL ioctl command of the UBI character
053:  * device should be used. A pointer to the 32-bit volume ID hast to be passed
054:  * to the ioctl.
055:  *
056:  * UBI volume re-size
057:  * ~~~~~~~~~~~~~~~~~~
058:  *
059:  * To re-size a volume, the %UBI_IOCRSVOL ioctl command of the UBI character
060:  * device should be used. A &struct ubi_rsvol_req object has to be properly
061:  * filled and a pointer to it has to be passed to the ioctl.
062:  *
063:  * UBI volumes re-name
064:  * ~~~~~~~~~~~~~~~~~~~
065:  *
066:  * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command
067:  * of the UBI character device should be used. A &struct ubi_rnvol_req object
068:  * has to be properly filled and a pointer to it has to be passed to the ioctl.
069:  *
070:  * UBI volume update
071:  * ~~~~~~~~~~~~~~~~~
072:  *
073:  * Volume update should be done via the %UBI_IOCVOLUP ioctl command of the
074:  * corresponding UBI volume character device. A pointer to a 64-bit update
075:  * size should be passed to the ioctl. After this, UBI expects user to write
076:  * this number of bytes to the volume character device. The update is finished
077:  * when the claimed number of bytes is passed. So, the volume update sequence
078:  * is something like:
079:  *
080:  * fd = open("/dev/my_volume");
081:  * ioctl(fd, UBI_IOCVOLUP, &image_size);
082:  * write(fd, buf, image_size);
083:  * close(fd);
084:  *
085:  * Logical eraseblock erase
086:  * ~~~~~~~~~~~~~~~~~~~~~~~~
087:  *
088:  * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the
089:  * corresponding UBI volume character device should be used. This command
090:  * unmaps the requested logical eraseblock, makes sure the corresponding
091:  * physical eraseblock is successfully erased, and returns.
092:  *
093:  * Atomic logical eraseblock change
094:  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
095:  *
096:  * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH
097:  * ioctl command of the corresponding UBI volume character device. A pointer to
098:  * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the
099:  * 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:  */
209: enum {
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:  */
221: enum {
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:  */
233: enum {
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:  */
266: struct 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:  */
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: } __attribute__((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: } __attribute__((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: } __attribute__((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:  */
381: struct ubi_leb_change_req {
382:         __s32 lnum;
383:         __s32 bytes;
384:         __s8  dtype;
385:         __s8  padding[7];
386: } __attribute__((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:  */
394: struct ubi_map_req {
395:         __s32 lnum;
396:         __s8  dtype;
397:         __s8  padding[3];
398: } __attribute__((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:  */
408: struct ubi_set_vol_prop_req {
409:         __u8  property;
410:         __u8  padding[7];
411:         __u64 value;
412: }  __attribute__((packed));
413: 
414: #endif /* __UBI_USER_H__ */
415: 

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