xref: /openbmc/u-boot/include/linux/mtd/ubi.h (revision efc05ae1)
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  * 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  * @min_io_size: minimal I/O unit size
120  * @ro_mode: if this device is in read-only mode
121  * @cdev: UBI character device major and minor numbers
122  *
123  * Note, @leb_size is the logical eraseblock size offered by the UBI device.
124  * Volumes of this UBI device may have smaller logical eraseblock size if their
125  * alignment is not equivalent to %1.
126  */
127 struct ubi_device_info {
128 	int ubi_num;
129 	int leb_size;
130 	int min_io_size;
131 	int ro_mode;
132 	dev_t cdev;
133 };
134 
135 /* UBI descriptor given to users when they open UBI volumes */
136 struct ubi_volume_desc;
137 
138 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di);
139 void ubi_get_volume_info(struct ubi_volume_desc *desc,
140 			 struct ubi_volume_info *vi);
141 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);
142 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
143 					   int mode);
144 void ubi_close_volume(struct ubi_volume_desc *desc);
145 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
146 		 int len, int check);
147 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
148 		  int offset, int len, int dtype);
149 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
150 		   int len, int dtype);
151 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);
152 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);
153 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);
154 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
155 
156 /*
157  * This function is the same as the 'ubi_leb_read()' function, but it does not
158  * provide the checking capability.
159  */
160 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf,
161 			   int offset, int len)
162 {
163 	return ubi_leb_read(desc, lnum, buf, offset, len, 0);
164 }
165 
166 /*
167  * This function is the same as the 'ubi_leb_write()' functions, but it does
168  * not have the data type argument.
169  */
170 static inline int ubi_write(struct ubi_volume_desc *desc, int lnum,
171 			    const void *buf, int offset, int len)
172 {
173 	return ubi_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);
174 }
175 
176 /*
177  * This function is the same as the 'ubi_leb_change()' functions, but it does
178  * not have the data type argument.
179  */
180 static inline int ubi_change(struct ubi_volume_desc *desc, int lnum,
181 				    const void *buf, int len)
182 {
183 	return ubi_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);
184 }
185 
186 #endif /* !__LINUX_UBI_H__ */
187