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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 <asm/ioctl.h>
25#include <linux/types.h>
26#include <mtd/ubi-user.h>
27
28/*
29 * UBI data type hint constants.
30 *
31 * UBI_LONGTERM: long-term data
32 * UBI_SHORTTERM: short-term data
33 * UBI_UNKNOWN: data persistence is unknown
34 *
35 * These constants are used when data is written to UBI volumes in order to
36 * help the UBI wear-leveling unit to find more appropriate physical
37 * eraseblocks.
38 */
39enum {
40 UBI_LONGTERM = 1,
41 UBI_SHORTTERM,
42 UBI_UNKNOWN
43};
44
45/*
46 * enum ubi_open_mode - UBI volume open mode constants.
47 *
48 * UBI_READONLY: read-only mode
49 * UBI_READWRITE: read-write mode
50 * UBI_EXCLUSIVE: exclusive mode
51 */
52enum {
53 UBI_READONLY = 1,
54 UBI_READWRITE,
55 UBI_EXCLUSIVE
56};
57
58/**
59 * struct ubi_volume_info - UBI volume description data structure.
60 * @vol_id: volume ID
61 * @ubi_num: UBI device number this volume belongs to
62 * @size: how many physical eraseblocks are reserved for this volume
63 * @used_bytes: how many bytes of data this volume contains
64 * @used_ebs: how many physical eraseblocks of this volume actually contain any
65 * data
66 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
67 * @corrupted: non-zero if the volume is corrupted (static volumes only)
68 * @upd_marker: non-zero if the volume has update marker set
69 * @alignment: volume alignment
70 * @usable_leb_size: how many bytes are available in logical eraseblocks of
71 * this volume
72 * @name_len: volume name length
73 * @name: volume name
74 * @cdev: UBI volume character device major and minor numbers
75 *
76 * The @corrupted flag is only relevant to static volumes and is always zero
77 * for dynamic ones. This is because UBI does not care about dynamic volume
78 * data protection and only cares about protecting static volume data.
79 *
80 * The @upd_marker flag is set if the volume update operation was interrupted.
81 * Before touching the volume data during the update operation, UBI first sets
82 * the update marker flag for this volume. If the volume update operation was
83 * further interrupted, the update marker indicates this. If the update marker
84 * is set, the contents of the volume is certainly damaged and a new volume
85 * update operation has to be started.
86 *
87 * To put it differently, @corrupted and @upd_marker fields have different
88 * semantics:
89 * o the @corrupted flag means that this static volume is corrupted for some
90 * reasons, but not because an interrupted volume update
91 * o the @upd_marker field means that the volume is damaged because of an
92 * interrupted update operation.
93 *
94 * I.e., the @corrupted flag is never set if the @upd_marker flag is set.
95 *
96 * The @used_bytes and @used_ebs fields are only really needed for static
97 * volumes and contain the number of bytes stored in this static volume and how
98 * many eraseblock this data occupies. In case of dynamic volumes, the
99 * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs
100 * field is equivalent to @size.
101 *
102 * In general, logical eraseblock size is a property of the UBI device, not
103 * of the UBI volume. Indeed, the logical eraseblock size depends on the
104 * physical eraseblock size and on how much bytes UBI headers consume. But
105 * because of the volume alignment (@alignment), the usable size of logical
106 * eraseblocks if a volume may be less. The following equation is true:
107 * @usable_leb_size = LEB size - (LEB size mod @alignment),
108 * where LEB size is the logical eraseblock size defined by the UBI device.
109 *
110 * The alignment is multiple to the minimal flash input/output unit size or %1
111 * if all the available space is used.
112 *
113 * To put this differently, alignment may be considered is a way to change
114 * volume logical eraseblock sizes.
115 */
116struct ubi_volume_info {
117 int ubi_num;
118 int vol_id;
119 int size;
120 long long used_bytes;
121 int used_ebs;
122 int vol_type;
123 int corrupted;
124 int upd_marker;
125 int alignment;
126 int usable_leb_size;
127 int name_len;
128 const char *name;
129 dev_t cdev;
130};
131
132/**
133 * struct ubi_device_info - UBI device description data structure.
134 * @ubi_num: ubi device number
135 * @leb_size: logical eraseblock size on this UBI device
136 * @min_io_size: minimal I/O unit size
137 * @ro_mode: if this device is in read-only mode
138 * @cdev: UBI character device major and minor numbers
139 *
140 * Note, @leb_size is the logical eraseblock size offered by the UBI device.
141 * Volumes of this UBI device may have smaller logical eraseblock size if their
142 * alignment is not equivalent to %1.
143 */
144struct ubi_device_info {
145 int ubi_num;
146 int leb_size;
147 int min_io_size;
148 int ro_mode;
149 dev_t cdev;
150};
151
152/* UBI descriptor given to users when they open UBI volumes */
153struct ubi_volume_desc;
154
155int ubi_get_device_info(int ubi_num, struct ubi_device_info *di);
156void ubi_get_volume_info(struct ubi_volume_desc *desc,
157 struct ubi_volume_info *vi);
158struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);
159struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
160 int mode);
161void ubi_close_volume(struct ubi_volume_desc *desc);
162int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
163 int len, int check);
164int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
165 int offset, int len, int dtype);
166int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
167 int len, int dtype);
168int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);
169int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);
170int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
171
172/*
173 * This function is the same as the 'ubi_leb_read()' function, but it does not
174 * provide the checking capability.
175 */
176static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf,
177 int offset, int len)
178{
179 return ubi_leb_read(desc, lnum, buf, offset, len, 0);
180}
181
182/*
183 * This function is the same as the 'ubi_leb_write()' functions, but it does
184 * not have the data type argument.
185 */
186static inline int ubi_write(struct ubi_volume_desc *desc, int lnum,
187 const void *buf, int offset, int len)
188{
189 return ubi_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);
190}
191
192/*
193 * This function is the same as the 'ubi_leb_change()' functions, but it does
194 * not have the data type argument.
195 */
196static inline int ubi_change(struct ubi_volume_desc *desc, int lnum,
197 const void *buf, int len)
198{
199 return ubi_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);
200}
201
202#endif /* !__LINUX_UBI_H__ */