1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
2 | /* |
3 | * Copyright (c) International Business Machines Corp., 2006 |
4 | * |
5 | * Author: Artem Bityutskiy (Битюцкий Артём) |
6 | */ |
7 | |
8 | #ifndef __LINUX_UBI_H__ |
9 | #define __LINUX_UBI_H__ |
10 | |
11 | #include <linux/ioctl.h> |
12 | #include <linux/types.h> |
13 | #include <linux/scatterlist.h> |
14 | #include <mtd/ubi-user.h> |
15 | |
16 | /* All voumes/LEBs */ |
17 | #define UBI_ALL -1 |
18 | |
19 | /* |
20 | * Maximum number of scatter gather list entries, |
21 | * we use only 64 to have a lower memory foot print. |
22 | */ |
23 | #define UBI_MAX_SG_COUNT 64 |
24 | |
25 | /* |
26 | * enum ubi_open_mode - UBI volume open mode constants. |
27 | * |
28 | * UBI_READONLY: read-only mode |
29 | * UBI_READWRITE: read-write mode |
30 | * UBI_EXCLUSIVE: exclusive mode |
31 | * UBI_METAONLY: modify only the volume meta-data, |
32 | * i.e. the data stored in the volume table, but not in any of volume LEBs. |
33 | */ |
34 | enum { |
35 | UBI_READONLY = 1, |
36 | UBI_READWRITE, |
37 | UBI_EXCLUSIVE, |
38 | UBI_METAONLY |
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 | struct device *dev; |
114 | }; |
115 | |
116 | /** |
117 | * struct ubi_sgl - UBI scatter gather list data structure. |
118 | * @list_pos: current position in @sg[] |
119 | * @page_pos: current position in @sg[@list_pos] |
120 | * @sg: the scatter gather list itself |
121 | * |
122 | * ubi_sgl is a wrapper around a scatter list which keeps track of the |
123 | * current position in the list and the current list item such that |
124 | * it can be used across multiple ubi_leb_read_sg() calls. |
125 | */ |
126 | struct ubi_sgl { |
127 | int list_pos; |
128 | int page_pos; |
129 | struct scatterlist sg[UBI_MAX_SG_COUNT]; |
130 | }; |
131 | |
132 | /** |
133 | * ubi_sgl_init - initialize an UBI scatter gather list data structure. |
134 | * @usgl: the UBI scatter gather struct itself |
135 | * |
136 | * Please note that you still have to use sg_init_table() or any adequate |
137 | * function to initialize the unterlaying struct scatterlist. |
138 | */ |
139 | static inline void ubi_sgl_init(struct ubi_sgl *usgl) |
140 | { |
141 | usgl->list_pos = 0; |
142 | usgl->page_pos = 0; |
143 | } |
144 | |
145 | /** |
146 | * struct ubi_device_info - UBI device description data structure. |
147 | * @ubi_num: ubi device number |
148 | * @leb_size: logical eraseblock size on this UBI device |
149 | * @leb_start: starting offset of logical eraseblocks within physical |
150 | * eraseblocks |
151 | * @min_io_size: minimal I/O unit size |
152 | * @max_write_size: maximum amount of bytes the underlying flash can write at a |
153 | * time (MTD write buffer size) |
154 | * @ro_mode: if this device is in read-only mode |
155 | * @cdev: UBI character device major and minor numbers |
156 | * |
157 | * Note, @leb_size is the logical eraseblock size offered by the UBI device. |
158 | * Volumes of this UBI device may have smaller logical eraseblock size if their |
159 | * alignment is not equivalent to %1. |
160 | * |
161 | * The @max_write_size field describes flash write maximum write unit. For |
162 | * example, NOR flash allows for changing individual bytes, so @min_io_size is |
163 | * %1. However, it does not mean than NOR flash has to write data byte-by-byte. |
164 | * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when |
165 | * writing large chunks of data, they write 64-bytes at a time. Obviously, this |
166 | * improves write throughput. |
167 | * |
168 | * Also, the MTD device may have N interleaved (striped) flash chips |
169 | * underneath, in which case @min_io_size can be physical min. I/O size of |
170 | * single flash chip, while @max_write_size can be N * @min_io_size. |
171 | * |
172 | * The @max_write_size field is always greater or equivalent to @min_io_size. |
173 | * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In |
174 | * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND |
175 | * page size. |
176 | */ |
177 | struct ubi_device_info { |
178 | int ubi_num; |
179 | int leb_size; |
180 | int leb_start; |
181 | int min_io_size; |
182 | int max_write_size; |
183 | int ro_mode; |
184 | dev_t cdev; |
185 | }; |
186 | |
187 | /* |
188 | * Volume notification types. |
189 | * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a |
190 | * volume was created) |
191 | * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached |
192 | * or a volume was removed) |
193 | * @UBI_VOLUME_RESIZED: a volume has been re-sized |
194 | * @UBI_VOLUME_RENAMED: a volume has been re-named |
195 | * @UBI_VOLUME_UPDATED: data has been written to a volume |
196 | * |
197 | * These constants define which type of event has happened when a volume |
198 | * notification function is invoked. |
199 | */ |
200 | enum { |
201 | UBI_VOLUME_ADDED, |
202 | UBI_VOLUME_REMOVED, |
203 | UBI_VOLUME_RESIZED, |
204 | UBI_VOLUME_RENAMED, |
205 | UBI_VOLUME_UPDATED, |
206 | }; |
207 | |
208 | /* |
209 | * struct ubi_notification - UBI notification description structure. |
210 | * @di: UBI device description object |
211 | * @vi: UBI volume description object |
212 | * |
213 | * UBI notifiers are called with a pointer to an object of this type. The |
214 | * object describes the notification. Namely, it provides a description of the |
215 | * UBI device and UBI volume the notification informs about. |
216 | */ |
217 | struct ubi_notification { |
218 | struct ubi_device_info di; |
219 | struct ubi_volume_info vi; |
220 | }; |
221 | |
222 | /* UBI descriptor given to users when they open UBI volumes */ |
223 | struct ubi_volume_desc; |
224 | |
225 | int ubi_get_device_info(int ubi_num, struct ubi_device_info *di); |
226 | void ubi_get_volume_info(struct ubi_volume_desc *desc, |
227 | struct ubi_volume_info *vi); |
228 | struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode); |
229 | struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, |
230 | int mode); |
231 | struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode); |
232 | |
233 | int ubi_register_volume_notifier(struct notifier_block *nb, |
234 | int ignore_existing); |
235 | int ubi_unregister_volume_notifier(struct notifier_block *nb); |
236 | |
237 | void ubi_close_volume(struct ubi_volume_desc *desc); |
238 | int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, |
239 | int len, int check); |
240 | int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl, |
241 | int offset, int len, int check); |
242 | int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, |
243 | int offset, int len); |
244 | int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, |
245 | int len); |
246 | int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum); |
247 | int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum); |
248 | int ubi_leb_map(struct ubi_volume_desc *desc, int lnum); |
249 | int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum); |
250 | int ubi_sync(int ubi_num); |
251 | int ubi_flush(int ubi_num, int vol_id, int lnum); |
252 | |
253 | /* |
254 | * This function is the same as the 'ubi_leb_read()' function, but it does not |
255 | * provide the checking capability. |
256 | */ |
257 | static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf, |
258 | int offset, int len) |
259 | { |
260 | return ubi_leb_read(desc, lnum, buf, offset, len, check: 0); |
261 | } |
262 | |
263 | /* |
264 | * This function is the same as the 'ubi_leb_read_sg()' function, but it does |
265 | * not provide the checking capability. |
266 | */ |
267 | static inline int ubi_read_sg(struct ubi_volume_desc *desc, int lnum, |
268 | struct ubi_sgl *sgl, int offset, int len) |
269 | { |
270 | return ubi_leb_read_sg(desc, lnum, sgl, offset, len, check: 0); |
271 | } |
272 | #endif /* !__LINUX_UBI_H__ */ |
273 | |