xref: /openbmc/linux/include/linux/mtd/ubi.h (revision b6dcefde)
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 /*
136  * enum - volume notification types.
137  * @UBI_VOLUME_ADDED: volume has been added
138  * @UBI_VOLUME_REMOVED: start volume volume
139  * @UBI_VOLUME_RESIZED: volume size has been re-sized
140  * @UBI_VOLUME_RENAMED: volume name has been re-named
141  * @UBI_VOLUME_UPDATED: volume name has been updated
142  *
143  * These constants define which type of event has happened when a volume
144  * notification function is invoked.
145  */
146 enum {
147 	UBI_VOLUME_ADDED,
148 	UBI_VOLUME_REMOVED,
149 	UBI_VOLUME_RESIZED,
150 	UBI_VOLUME_RENAMED,
151 	UBI_VOLUME_UPDATED,
152 };
153 
154 /*
155  * struct ubi_notification - UBI notification description structure.
156  * @di: UBI device description object
157  * @vi: UBI volume description object
158  *
159  * UBI notifiers are called with a pointer to an object of this type. The
160  * object describes the notification. Namely, it provides a description of the
161  * UBI device and UBI volume the notification informs about.
162  */
163 struct ubi_notification {
164 	struct ubi_device_info di;
165 	struct ubi_volume_info vi;
166 };
167 
168 /* UBI descriptor given to users when they open UBI volumes */
169 struct ubi_volume_desc;
170 
171 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di);
172 void ubi_get_volume_info(struct ubi_volume_desc *desc,
173 			 struct ubi_volume_info *vi);
174 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);
175 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
176 					   int mode);
177 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode);
178 
179 int ubi_register_volume_notifier(struct notifier_block *nb,
180 				 int ignore_existing);
181 int ubi_unregister_volume_notifier(struct notifier_block *nb);
182 
183 void ubi_close_volume(struct ubi_volume_desc *desc);
184 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
185 		 int len, int check);
186 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
187 		  int offset, int len, int dtype);
188 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
189 		   int len, int dtype);
190 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);
191 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);
192 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);
193 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
194 int ubi_sync(int ubi_num);
195 
196 /*
197  * This function is the same as the 'ubi_leb_read()' function, but it does not
198  * provide the checking capability.
199  */
200 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf,
201 			   int offset, int len)
202 {
203 	return ubi_leb_read(desc, lnum, buf, offset, len, 0);
204 }
205 
206 /*
207  * This function is the same as the 'ubi_leb_write()' functions, but it does
208  * not have the data type argument.
209  */
210 static inline int ubi_write(struct ubi_volume_desc *desc, int lnum,
211 			    const void *buf, int offset, int len)
212 {
213 	return ubi_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);
214 }
215 
216 /*
217  * This function is the same as the 'ubi_leb_change()' functions, but it does
218  * not have the data type argument.
219  */
220 static inline int ubi_change(struct ubi_volume_desc *desc, int lnum,
221 				    const void *buf, int len)
222 {
223 	return ubi_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);
224 }
225 
226 #endif /* !__LINUX_UBI_H__ */
227