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