summaryrefslogtreecommitdiffstats
path: root/include/linux/mtd/ubi.h
blob: 6913b71d9ab2b1654d6332fc56af8485154943ec (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
/*
 * Copyright (c) International Business Machines Corp., 2006
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
 * the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Author: Artem Bityutskiy (Битюцкий Артём)
 */

#ifndef __LINUX_UBI_H__
#define __LINUX_UBI_H__

#include <asm/ioctl.h>
#include <linux/types.h>
#include <mtd/ubi-user.h>

/*
 * enum ubi_open_mode - UBI volume open mode constants.
 *
 * UBI_READONLY: read-only mode
 * UBI_READWRITE: read-write mode
 * UBI_EXCLUSIVE: exclusive mode
 */
enum {
	UBI_READONLY = 1,
	UBI_READWRITE,
	UBI_EXCLUSIVE
};

/**
 * struct ubi_volume_info - UBI volume description data structure.
 * @vol_id: volume ID
 * @ubi_num: UBI device number this volume belongs to
 * @size: how many physical eraseblocks are reserved for this volume
 * @used_bytes: how many bytes of data this volume contains
 * @used_ebs: how many physical eraseblocks of this volume actually contain any
 *            data
 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
 * @corrupted: non-zero if the volume is corrupted (static volumes only)
 * @upd_marker: non-zero if the volume has update marker set
 * @alignment: volume alignment
 * @usable_leb_size: how many bytes are available in logical eraseblocks of
 *                   this volume
 * @name_len: volume name length
 * @name: volume name
 * @cdev: UBI volume character device major and minor numbers
 *
 * The @corrupted flag is only relevant to static volumes and is always zero
 * for dynamic ones. This is because UBI does not care about dynamic volume
 * data protection and only cares about protecting static volume data.
 *
 * The @upd_marker flag is set if the volume update operation was interrupted.
 * Before touching the volume data during the update operation, UBI first sets
 * the update marker flag for this volume. If the volume update operation was
 * further interrupted, the update marker indicates this. If the update marker
 * is set, the contents of the volume is certainly damaged and a new volume
 * update operation has to be started.
 *
 * To put it differently, @corrupted and @upd_marker fields have different
 * semantics:
 *     o the @corrupted flag means that this static volume is corrupted for some
 *       reasons, but not because an interrupted volume update
 *     o the @upd_marker field means that the volume is damaged because of an
 *       interrupted update operation.
 *
 * I.e., the @corrupted flag is never set if the @upd_marker flag is set.
 *
 * The @used_bytes and @used_ebs fields are only really needed for static
 * volumes and contain the number of bytes stored in this static volume and how
 * many eraseblock this data occupies. In case of dynamic volumes, the
 * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs
 * field is equivalent to @size.
 *
 * In general, logical eraseblock size is a property of the UBI device, not
 * of the UBI volume. Indeed, the logical eraseblock size depends on the
 * physical eraseblock size and on how much bytes UBI headers consume. But
 * because of the volume alignment (@alignment), the usable size of logical
 * eraseblocks if a volume may be less. The following equation is true:
 * 	@usable_leb_size = LEB size - (LEB size mod @alignment),
 * where LEB size is the logical eraseblock size defined by the UBI device.
 *
 * The alignment is multiple to the minimal flash input/output unit size or %1
 * if all the available space is used.
 *
 * To put this differently, alignment may be considered is a way to change
 * volume logical eraseblock sizes.
 */
struct ubi_volume_info {
	int ubi_num;
	int vol_id;
	int size;
	long long used_bytes;
	int used_ebs;
	int vol_type;
	int corrupted;
	int upd_marker;
	int alignment;
	int usable_leb_size;
	int name_len;
	const char *name;
	dev_t cdev;
};

/**
 * struct ubi_device_info - UBI device description data structure.
 * @ubi_num: ubi device number
 * @leb_size: logical eraseblock size on this UBI device
 * @min_io_size: minimal I/O unit size
 * @ro_mode: if this device is in read-only mode
 * @cdev: UBI character device major and minor numbers
 *
 * Note, @leb_size is the logical eraseblock size offered by the UBI device.
 * Volumes of this UBI device may have smaller logical eraseblock size if their
 * alignment is not equivalent to %1.
 */
struct ubi_device_info {
	int ubi_num;
	int leb_size;
	int min_io_size;
	int ro_mode;
	dev_t cdev;
};

/*
 * enum - volume notification types.
 * @UBI_VOLUME_ADDED: volume has been added
 * @UBI_VOLUME_REMOVED: start volume volume
 * @UBI_VOLUME_RESIZED: volume size has been re-sized
 * @UBI_VOLUME_RENAMED: volume name has been re-named
 * @UBI_VOLUME_UPDATED: volume name has been updated
 *
 * These constants define which type of event has happened when a volume
 * notification function is invoked.
 */
enum {
	UBI_VOLUME_ADDED,
	UBI_VOLUME_REMOVED,
	UBI_VOLUME_RESIZED,
	UBI_VOLUME_RENAMED,
	UBI_VOLUME_UPDATED,
};

/*
 * struct ubi_notification - UBI notification description structure.
 * @di: UBI device description object
 * @vi: UBI volume description object
 *
 * UBI notifiers are called with a pointer to an object of this type. The
 * object describes the notification. Namely, it provides a description of the
 * UBI device and UBI volume the notification informs about.
 */
struct ubi_notification {
	struct ubi_device_info di;
	struct ubi_volume_info vi;
};

/* UBI descriptor given to users when they open UBI volumes */
struct ubi_volume_desc;

int ubi_get_device_info(int ubi_num, struct ubi_device_info *di);
void ubi_get_volume_info(struct ubi_volume_desc *desc,
			 struct ubi_volume_info *vi);
struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);
struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
					   int mode);
int ubi_register_volume_notifier(struct notifier_block *nb,
				 int ignore_existing);
int ubi_unregister_volume_notifier(struct notifier_block *nb);

void ubi_close_volume(struct ubi_volume_desc *desc);
int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
		 int len, int check);
int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
		  int offset, int len, int dtype);
int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
		   int len, int dtype);
int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);
int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);
int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);
int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
int ubi_sync(int ubi_num);

/*
 * This function is the same as the 'ubi_leb_read()' function, but it does not
 * provide the checking capability.
 */
static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf,
			   int offset, int len)
{
	return ubi_leb_read(desc, lnum, buf, offset, len, 0);
}

/*
 * This function is the same as the 'ubi_leb_write()' functions, but it does
 * not have the data type argument.
 */
static inline int ubi_write(struct ubi_volume_desc *desc, int lnum,
			    const void *buf, int offset, int len)
{
	return ubi_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);
}

/*
 * This function is the same as the 'ubi_leb_change()' functions, but it does
 * not have the data type argument.
 */
static inline int ubi_change(struct ubi_volume_desc *desc, int lnum,
				    const void *buf, int len)
{
	return ubi_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);
}

#endif /* !__LINUX_UBI_H__ */