1 /*
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 __LINUX_UBI_H__
22 #define __LINUX_UBI_H__
23
24 #include <linux/ioctl.h>
25 #include <linux/types.h>
26 #include <mtd/ubi-user.h>
27
28 /*
29 * enum ubi_open_mode - UBI volume open mode constants.
30 *
31 * UBI_READONLY: read-only mode
32 * UBI_READWRITE: read-write mode
33 * UBI_EXCLUSIVE: exclusive mode
34 */
35 enum {
36 UBI_READONLY = 1,
37 UBI_READWRITE,
38 UBI_EXCLUSIVE
39 };
40
41 /**
42 * struct ubi_volume_info - UBI volume description data structure.
43 * @vol_id: volume ID
44 * @ubi_num: UBI device number this volume belongs to
45 * @size: how many physical eraseblocks are reserved for this volume
46 * @used_bytes: how many bytes of data this volume contains
47 * @used_ebs: how many physical eraseblocks of this volume actually contain any
48 * data
49 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
50 * @corrupted: non-zero if the volume is corrupted (static volumes only)
51 * @upd_marker: non-zero if the volume has update marker set
52 * @alignment: volume alignment
53 * @usable_leb_size: how many bytes are available in logical eraseblocks of
54 * this volume
55 * @name_len: volume name length
56 * @name: volume name
57 * @cdev: UBI volume character device major and minor numbers
58 *
59 * The @corrupted flag is only relevant to static volumes and is always zero
60 * for dynamic ones. This is because UBI does not care about dynamic volume
61 * data protection and only cares about protecting static volume data.
62 *
63 * The @upd_marker flag is set if the volume update operation was interrupted.
64 * Before touching the volume data during the update operation, UBI first sets
65 * the update marker flag for this volume. If the volume update operation was
66 * further interrupted, the update marker indicates this. If the update marker
67 * is set, the contents of the volume is certainly damaged and a new volume
68 * update operation has to be started.
69 *
70 * To put it differently, @corrupted and @upd_marker fields have different
71 * semantics:
72 * o the @corrupted flag means that this static volume is corrupted for some
73 * reasons, but not because an interrupted volume update
74 * o the @upd_marker field means that the volume is damaged because of an
75 * interrupted update operation.
76 *
77 * I.e., the @corrupted flag is never set if the @upd_marker flag is set.
78 *
79 * The @used_bytes and @used_ebs fields are only really needed for static
80 * volumes and contain the number of bytes stored in this static volume and how
81 * many eraseblock this data occupies. In case of dynamic volumes, the
82 * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs
83 * field is equivalent to @size.
84 *
85 * In general, logical eraseblock size is a property of the UBI device, not
86 * of the UBI volume. Indeed, the logical eraseblock size depends on the
87 * physical eraseblock size and on how much bytes UBI headers consume. But
88 * because of the volume alignment (@alignment), the usable size of logical
89 * eraseblocks if a volume may be less. The following equation is true:
90 * @usable_leb_size = LEB size - (LEB size mod @alignment),
91 * where LEB size is the logical eraseblock size defined by the UBI device.
92 *
93 * The alignment is multiple to the minimal flash input/output unit size or %1
94 * if all the available space is used.
95 *
96 * To put this differently, alignment may be considered is a way to change
97 * volume logical eraseblock sizes.
98 */
99 struct ubi_volume_info {
100 int ubi_num;
101 int vol_id;
102 int size;
103 long long used_bytes;
104 int used_ebs;
105 int vol_type;
106 int corrupted;
107 int upd_marker;
108 int alignment;
109 int usable_leb_size;
110 int name_len;
111 const char *name;
112 dev_t cdev;
113 };
114
115 /**
116 * struct ubi_device_info - UBI device description data structure.
117 * @ubi_num: ubi device number
118 * @leb_size: logical eraseblock size on this UBI device
119 * @leb_start: starting offset of logical eraseblocks within physical
120 * eraseblocks
121 * @min_io_size: minimal I/O unit size
122 * @max_write_size: maximum amount of bytes the underlying flash can write at a
123 * time (MTD write buffer size)
124 * @ro_mode: if this device is in read-only mode
125 * @cdev: UBI character device major and minor numbers
126 *
127 * Note, @leb_size is the logical eraseblock size offered by the UBI device.
128 * Volumes of this UBI device may have smaller logical eraseblock size if their
129 * alignment is not equivalent to %1.
130 *
131 * The @max_write_size field describes flash write maximum write unit. For
132 * example, NOR flash allows for changing individual bytes, so @min_io_size is
133 * %1. However, it does not mean than NOR flash has to write data byte-by-byte.
134 * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when
135 * writing large chunks of data, they write 64-bytes at a time. Obviously, this
136 * improves write throughput.
137 *
138 * Also, the MTD device may have N interleaved (striped) flash chips
139 * underneath, in which case @min_io_size can be physical min. I/O size of
140 * single flash chip, while @max_write_size can be N * @min_io_size.
141 *
142 * The @max_write_size field is always greater or equivalent to @min_io_size.
143 * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In
144 * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND
145 * page size.
146 */
147 struct ubi_device_info {
148 int ubi_num;
149 int leb_size;
150 int leb_start;
151 int min_io_size;
152 int max_write_size;
153 int ro_mode;
154 dev_t cdev;
155 };
156
157 /*
158 * Volume notification types.
159 * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a
160 * volume was created)
161 * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached
162 * or a volume was removed)
163 * @UBI_VOLUME_RESIZED: a volume has been re-sized
164 * @UBI_VOLUME_RENAMED: a volume has been re-named
165 * @UBI_VOLUME_UPDATED: data has been written to a volume
166 *
167 * These constants define which type of event has happened when a volume
168 * notification function is invoked.
169 */
170 enum {
171 UBI_VOLUME_ADDED,
172 UBI_VOLUME_REMOVED,
173 UBI_VOLUME_RESIZED,
174 UBI_VOLUME_RENAMED,
175 UBI_VOLUME_UPDATED,
176 };
177
178 /*
179 * struct ubi_notification - UBI notification description structure.
180 * @di: UBI device description object
181 * @vi: UBI volume description object
182 *
183 * UBI notifiers are called with a pointer to an object of this type. The
184 * object describes the notification. Namely, it provides a description of the
185 * UBI device and UBI volume the notification informs about.
186 */
187 struct ubi_notification {
188 struct ubi_device_info di;
189 struct ubi_volume_info vi;
190 };
191
192 /* UBI descriptor given to users when they open UBI volumes */
193 struct ubi_volume_desc;
194
195 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di);
196 void ubi_get_volume_info(struct ubi_volume_desc *desc,
197 struct ubi_volume_info *vi);
198 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);
199 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
200 int mode);
201 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode);
202
203 int ubi_register_volume_notifier(struct notifier_block *nb,
204 int ignore_existing);
205 int ubi_unregister_volume_notifier(struct notifier_block *nb);
206
207 void ubi_close_volume(struct ubi_volume_desc *desc);
208 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
209 int len, int check);
210 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
211 int offset, int len, int dtype);
212 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
213 int len, int dtype);
214 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);
215 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);
216 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);
217 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
218 int ubi_sync(int ubi_num);
219
220 /*
221 * This function is the same as the 'ubi_leb_read()' function, but it does not
222 * provide the checking capability.
223 */
ubi_read(struct ubi_volume_desc * desc,int lnum,char * buf,int offset,int len)224 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf,
225 int offset, int len)
226 {
227 return ubi_leb_read(desc, lnum, buf, offset, len, 0);
228 }
229
230 /*
231 * This function is the same as the 'ubi_leb_write()' functions, but it does
232 * not have the data type argument.
233 */
ubi_write(struct ubi_volume_desc * desc,int lnum,const void * buf,int offset,int len)234 static inline int ubi_write(struct ubi_volume_desc *desc, int lnum,
235 const void *buf, int offset, int len)
236 {
237 return ubi_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);
238 }
239
240 /*
241 * This function is the same as the 'ubi_leb_change()' functions, but it does
242 * not have the data type argument.
243 */
ubi_change(struct ubi_volume_desc * desc,int lnum,const void * buf,int len)244 static inline int ubi_change(struct ubi_volume_desc *desc, int lnum,
245 const void *buf, int len)
246 {
247 return ubi_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);
248 }
249
250 #endif /* !__LINUX_UBI_H__ */
251