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Kyungmin Park47ae6692008-11-19 16:36:36 +01001/*
2 * Copyright (c) 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/*
25 * UBI device creation (the same as MTD device attachment)
26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
27 *
28 * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI
29 * control device. The caller has to properly fill and pass
30 * &struct ubi_attach_req object - UBI will attach the MTD device specified in
31 * the request and return the newly created UBI device number as the ioctl
32 * return value.
33 *
34 * UBI device deletion (the same as MTD device detachment)
35 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
36 *
37 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI
38 * control device.
39 *
40 * UBI volume creation
41 * ~~~~~~~~~~~~~~~~~~~
42 *
43 * UBI volumes are created via the %UBI_IOCMKVOL IOCTL command of UBI character
44 * device. A &struct ubi_mkvol_req object has to be properly filled and a
45 * pointer to it has to be passed to the IOCTL.
46 *
47 * UBI volume deletion
48 * ~~~~~~~~~~~~~~~~~~~
49 *
50 * To delete a volume, the %UBI_IOCRMVOL IOCTL command of the UBI character
51 * device should be used. A pointer to the 32-bit volume ID hast to be passed
52 * to the IOCTL.
53 *
54 * UBI volume re-size
55 * ~~~~~~~~~~~~~~~~~~
56 *
57 * To re-size a volume, the %UBI_IOCRSVOL IOCTL command of the UBI character
58 * device should be used. A &struct ubi_rsvol_req object has to be properly
59 * filled and a pointer to it has to be passed to the IOCTL.
60 *
61 * UBI volume update
62 * ~~~~~~~~~~~~~~~~~
63 *
64 * Volume update should be done via the %UBI_IOCVOLUP IOCTL command of the
65 * corresponding UBI volume character device. A pointer to a 64-bit update
66 * size should be passed to the IOCTL. After this, UBI expects user to write
67 * this number of bytes to the volume character device. The update is finished
68 * when the claimed number of bytes is passed. So, the volume update sequence
69 * is something like:
70 *
71 * fd = open("/dev/my_volume");
72 * ioctl(fd, UBI_IOCVOLUP, &image_size);
73 * write(fd, buf, image_size);
74 * close(fd);
75 *
76 * Atomic eraseblock change
77 * ~~~~~~~~~~~~~~~~~~~~~~~~
78 *
79 * Atomic eraseblock change operation is done via the %UBI_IOCEBCH IOCTL
80 * command of the corresponding UBI volume character device. A pointer to
81 * &struct ubi_leb_change_req has to be passed to the IOCTL. Then the user is
82 * expected to write the requested amount of bytes. This is similar to the
83 * "volume update" IOCTL.
84 */
85
86/*
87 * When a new UBI volume or UBI device is created, users may either specify the
88 * volume/device number they want to create or to let UBI automatically assign
89 * the number using these constants.
90 */
91#define UBI_VOL_NUM_AUTO (-1)
92#define UBI_DEV_NUM_AUTO (-1)
93
94/* Maximum volume name length */
95#define UBI_MAX_VOLUME_NAME 127
96
97/* IOCTL commands of UBI character devices */
98
99#define UBI_IOC_MAGIC 'o'
100
101/* Create an UBI volume */
102#define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req)
103/* Remove an UBI volume */
104#define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t)
105/* Re-size an UBI volume */
106#define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)
107
108/* IOCTL commands of the UBI control character device */
109
110#define UBI_CTRL_IOC_MAGIC 'o'
111
112/* Attach an MTD device */
113#define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req)
114/* Detach an MTD device */
115#define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, int32_t)
116
117/* IOCTL commands of UBI volume character devices */
118
119#define UBI_VOL_IOC_MAGIC 'O'
120
121/* Start UBI volume update */
122#define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t)
123/* An eraseblock erasure command, used for debugging, disabled by default */
124#define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t)
125/* An atomic eraseblock change command */
126#define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, int32_t)
127
128/* Maximum MTD device name length supported by UBI */
129#define MAX_UBI_MTD_NAME_LEN 127
130
131/*
132 * UBI data type hint constants.
133 *
134 * UBI_LONGTERM: long-term data
135 * UBI_SHORTTERM: short-term data
136 * UBI_UNKNOWN: data persistence is unknown
137 *
138 * These constants are used when data is written to UBI volumes in order to
139 * help the UBI wear-leveling unit to find more appropriate physical
140 * eraseblocks.
141 */
142enum {
143 UBI_LONGTERM = 1,
144 UBI_SHORTTERM = 2,
145 UBI_UNKNOWN = 3,
146};
147
148/*
149 * UBI volume type constants.
150 *
151 * @UBI_DYNAMIC_VOLUME: dynamic volume
152 * @UBI_STATIC_VOLUME: static volume
153 */
154enum {
155 UBI_DYNAMIC_VOLUME = 3,
156 UBI_STATIC_VOLUME = 4,
157};
158
159/**
160 * struct ubi_attach_req - attach MTD device request.
161 * @ubi_num: UBI device number to create
162 * @mtd_num: MTD device number to attach
163 * @vid_hdr_offset: VID header offset (use defaults if %0)
164 * @padding: reserved for future, not used, has to be zeroed
165 *
166 * This data structure is used to specify MTD device UBI has to attach and the
167 * parameters it has to use. The number which should be assigned to the new UBI
168 * device is passed in @ubi_num. UBI may automatically assign the number if
169 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in
170 * @ubi_num.
171 *
172 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default
173 * offset of the VID header within physical eraseblocks. The default offset is
174 * the next min. I/O unit after the EC header. For example, it will be offset
175 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or
176 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages.
177 *
178 * But in rare cases, if this optimizes things, the VID header may be placed to
179 * a different offset. For example, the boot-loader might do things faster if the
180 * VID header sits at the end of the first 2KiB NAND page with 4 sub-pages. As
181 * the boot-loader would not normally need to read EC headers (unless it needs
182 * UBI in RW mode), it might be faster to calculate ECC. This is weird example,
183 * but it real-life example. So, in this example, @vid_hdr_offer would be
184 * 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
185 * aligned, which is OK, as UBI is clever enough to realize this is 4th sub-page
186 * of the first page and add needed padding.
187 */
188struct ubi_attach_req {
189 int32_t ubi_num;
190 int32_t mtd_num;
191 int32_t vid_hdr_offset;
192 uint8_t padding[12];
193};
194
195/**
196 * struct ubi_mkvol_req - volume description data structure used in
197 * volume creation requests.
198 * @vol_id: volume number
199 * @alignment: volume alignment
200 * @bytes: volume size in bytes
201 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
202 * @padding1: reserved for future, not used, has to be zeroed
203 * @name_len: volume name length
204 * @padding2: reserved for future, not used, has to be zeroed
205 * @name: volume name
206 *
207 * This structure is used by user-space programs when creating new volumes. The
208 * @used_bytes field is only necessary when creating static volumes.
209 *
210 * The @alignment field specifies the required alignment of the volume logical
211 * eraseblock. This means, that the size of logical eraseblocks will be aligned
212 * to this number, i.e.,
213 * (UBI device logical eraseblock size) mod (@alignment) = 0.
214 *
215 * To put it differently, the logical eraseblock of this volume may be slightly
216 * shortened in order to make it properly aligned. The alignment has to be
217 * multiple of the flash minimal input/output unit, or %1 to utilize the entire
218 * available space of logical eraseblocks.
219 *
220 * The @alignment field may be useful, for example, when one wants to maintain
221 * a block device on top of an UBI volume. In this case, it is desirable to fit
222 * an integer number of blocks in logical eraseblocks of this UBI volume. With
223 * alignment it is possible to update this volume using plane UBI volume image
224 * BLOBs, without caring about how to properly align them.
225 */
226struct ubi_mkvol_req {
227 int32_t vol_id;
228 int32_t alignment;
229 int64_t bytes;
230 int8_t vol_type;
231 int8_t padding1;
232 int16_t name_len;
233 int8_t padding2[4];
234 char name[UBI_MAX_VOLUME_NAME + 1];
235} __attribute__ ((packed));
236
237/**
238 * struct ubi_rsvol_req - a data structure used in volume re-size requests.
239 * @vol_id: ID of the volume to re-size
240 * @bytes: new size of the volume in bytes
241 *
242 * Re-sizing is possible for both dynamic and static volumes. But while dynamic
243 * volumes may be re-sized arbitrarily, static volumes cannot be made to be
244 * smaller then the number of bytes they bear. To arbitrarily shrink a static
245 * volume, it must be wiped out first (by means of volume update operation with
246 * zero number of bytes).
247 */
248struct ubi_rsvol_req {
249 int64_t bytes;
250 int32_t vol_id;
251} __attribute__ ((packed));
252
253/**
254 * struct ubi_leb_change_req - a data structure used in atomic logical
255 * eraseblock change requests.
256 * @lnum: logical eraseblock number to change
257 * @bytes: how many bytes will be written to the logical eraseblock
258 * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
259 * @padding: reserved for future, not used, has to be zeroed
260 */
261struct ubi_leb_change_req {
262 int32_t lnum;
263 int32_t bytes;
264 uint8_t dtype;
265 uint8_t padding[7];
266} __attribute__ ((packed));
267
268#endif /* __UBI_USER_H__ */