• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* SPDX-License-Identifier: GPL-2.0+ */
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/types.h>
12 #ifndef __UBOOT__
13 #include <linux/ioctl.h>
14 #include <linux/scatterlist.h>
15 #include <mtd/ubi-user.h>
16 #endif
17 
18 /* All voumes/LEBs */
19 #define UBI_ALL -1
20 
21 /*
22  * Maximum number of scatter gather list entries,
23  * we use only 64 to have a lower memory foot print.
24  */
25 #define UBI_MAX_SG_COUNT 64
26 
27 /*
28  * enum ubi_open_mode - UBI volume open mode constants.
29  *
30  * UBI_READONLY: read-only mode
31  * UBI_READWRITE: read-write mode
32  * UBI_EXCLUSIVE: exclusive mode
33  * UBI_METAONLY: modify only the volume meta-data,
34  *  i.e. the data stored in the volume table, but not in any of volume LEBs.
35  */
36 enum {
37 	UBI_READONLY = 1,
38 	UBI_READWRITE,
39 	UBI_EXCLUSIVE,
40 	UBI_METAONLY
41 };
42 
43 /**
44  * struct ubi_volume_info - UBI volume description data structure.
45  * @vol_id: volume ID
46  * @ubi_num: UBI device number this volume belongs to
47  * @size: how many physical eraseblocks are reserved for this volume
48  * @used_bytes: how many bytes of data this volume contains
49  * @used_ebs: how many physical eraseblocks of this volume actually contain any
50  *            data
51  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
52  * @corrupted: non-zero if the volume is corrupted (static volumes only)
53  * @upd_marker: non-zero if the volume has update marker set
54  * @alignment: volume alignment
55  * @usable_leb_size: how many bytes are available in logical eraseblocks of
56  *                   this volume
57  * @name_len: volume name length
58  * @name: volume name
59  * @cdev: UBI volume character device major and minor numbers
60  *
61  * The @corrupted flag is only relevant to static volumes and is always zero
62  * for dynamic ones. This is because UBI does not care about dynamic volume
63  * data protection and only cares about protecting static volume data.
64  *
65  * The @upd_marker flag is set if the volume update operation was interrupted.
66  * Before touching the volume data during the update operation, UBI first sets
67  * the update marker flag for this volume. If the volume update operation was
68  * further interrupted, the update marker indicates this. If the update marker
69  * is set, the contents of the volume is certainly damaged and a new volume
70  * update operation has to be started.
71  *
72  * To put it differently, @corrupted and @upd_marker fields have different
73  * semantics:
74  *     o the @corrupted flag means that this static volume is corrupted for some
75  *       reasons, but not because an interrupted volume update
76  *     o the @upd_marker field means that the volume is damaged because of an
77  *       interrupted update operation.
78  *
79  * I.e., the @corrupted flag is never set if the @upd_marker flag is set.
80  *
81  * The @used_bytes and @used_ebs fields are only really needed for static
82  * volumes and contain the number of bytes stored in this static volume and how
83  * many eraseblock this data occupies. In case of dynamic volumes, the
84  * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs
85  * field is equivalent to @size.
86  *
87  * In general, logical eraseblock size is a property of the UBI device, not
88  * of the UBI volume. Indeed, the logical eraseblock size depends on the
89  * physical eraseblock size and on how much bytes UBI headers consume. But
90  * because of the volume alignment (@alignment), the usable size of logical
91  * eraseblocks if a volume may be less. The following equation is true:
92  *	@usable_leb_size = LEB size - (LEB size mod @alignment),
93  * where LEB size is the logical eraseblock size defined by the UBI device.
94  *
95  * The alignment is multiple to the minimal flash input/output unit size or %1
96  * if all the available space is used.
97  *
98  * To put this differently, alignment may be considered is a way to change
99  * volume logical eraseblock sizes.
100  */
101 struct ubi_volume_info {
102 	int ubi_num;
103 	int vol_id;
104 	int size;
105 	long long used_bytes;
106 	int used_ebs;
107 	int vol_type;
108 	int corrupted;
109 	int upd_marker;
110 	int alignment;
111 	int usable_leb_size;
112 	int name_len;
113 	const char *name;
114 	dev_t cdev;
115 };
116 
117 /**
118  * struct ubi_sgl - UBI scatter gather list data structure.
119  * @list_pos: current position in @sg[]
120  * @page_pos: current position in @sg[@list_pos]
121  * @sg: the scatter gather list itself
122  *
123  * ubi_sgl is a wrapper around a scatter list which keeps track of the
124  * current position in the list and the current list item such that
125  * it can be used across multiple ubi_leb_read_sg() calls.
126  */
127 struct ubi_sgl {
128 	int list_pos;
129 	int page_pos;
130 #ifndef __UBOOT__
131 	struct scatterlist sg[UBI_MAX_SG_COUNT];
132 #endif
133 };
134 
135 /**
136  * ubi_sgl_init - initialize an UBI scatter gather list data structure.
137  * @usgl: the UBI scatter gather struct itself
138  *
139  * Please note that you still have to use sg_init_table() or any adequate
140  * function to initialize the unterlaying struct scatterlist.
141  */
ubi_sgl_init(struct ubi_sgl * usgl)142 static inline void ubi_sgl_init(struct ubi_sgl *usgl)
143 {
144 	usgl->list_pos = 0;
145 	usgl->page_pos = 0;
146 }
147 
148 /**
149  * struct ubi_device_info - UBI device description data structure.
150  * @ubi_num: ubi device number
151  * @leb_size: logical eraseblock size on this UBI device
152  * @leb_start: starting offset of logical eraseblocks within physical
153  *             eraseblocks
154  * @min_io_size: minimal I/O unit size
155  * @max_write_size: maximum amount of bytes the underlying flash can write at a
156  *                  time (MTD write buffer size)
157  * @ro_mode: if this device is in read-only mode
158  * @cdev: UBI character device major and minor numbers
159  *
160  * Note, @leb_size is the logical eraseblock size offered by the UBI device.
161  * Volumes of this UBI device may have smaller logical eraseblock size if their
162  * alignment is not equivalent to %1.
163  *
164  * The @max_write_size field describes flash write maximum write unit. For
165  * example, NOR flash allows for changing individual bytes, so @min_io_size is
166  * %1. However, it does not mean than NOR flash has to write data byte-by-byte.
167  * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when
168  * writing large chunks of data, they write 64-bytes at a time. Obviously, this
169  * improves write throughput.
170  *
171  * Also, the MTD device may have N interleaved (striped) flash chips
172  * underneath, in which case @min_io_size can be physical min. I/O size of
173  * single flash chip, while @max_write_size can be N * @min_io_size.
174  *
175  * The @max_write_size field is always greater or equivalent to @min_io_size.
176  * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In
177  * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND
178  * page size.
179  */
180 struct ubi_device_info {
181 	int ubi_num;
182 	int leb_size;
183 	int leb_start;
184 	int min_io_size;
185 	int max_write_size;
186 	int ro_mode;
187 #ifndef __UBOOT__
188 	dev_t cdev;
189 #endif
190 };
191 
192 /*
193  * Volume notification types.
194  * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a
195  *                    volume was created)
196  * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached
197  *			or a volume was removed)
198  * @UBI_VOLUME_RESIZED: a volume has been re-sized
199  * @UBI_VOLUME_RENAMED: a volume has been re-named
200  * @UBI_VOLUME_UPDATED: data has been written to a volume
201  *
202  * These constants define which type of event has happened when a volume
203  * notification function is invoked.
204  */
205 enum {
206 	UBI_VOLUME_ADDED,
207 	UBI_VOLUME_REMOVED,
208 	UBI_VOLUME_RESIZED,
209 	UBI_VOLUME_RENAMED,
210 	UBI_VOLUME_UPDATED,
211 };
212 
213 /*
214  * struct ubi_notification - UBI notification description structure.
215  * @di: UBI device description object
216  * @vi: UBI volume description object
217  *
218  * UBI notifiers are called with a pointer to an object of this type. The
219  * object describes the notification. Namely, it provides a description of the
220  * UBI device and UBI volume the notification informs about.
221  */
222 struct ubi_notification {
223 	struct ubi_device_info di;
224 	struct ubi_volume_info vi;
225 };
226 
227 /* UBI descriptor given to users when they open UBI volumes */
228 struct ubi_volume_desc;
229 
230 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di);
231 void ubi_get_volume_info(struct ubi_volume_desc *desc,
232 			 struct ubi_volume_info *vi);
233 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);
234 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
235 					   int mode);
236 struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode);
237 
238 #ifndef __UBOOT__
239 typedef	int (*notifier_fn_t)(void *nb,
240 			unsigned long action, void *data);
241 
242 struct notifier_block {
243 	notifier_fn_t notifier_call;
244 	struct notifier_block *next;
245 	void *next;
246 	int priority;
247 };
248 
249 int ubi_register_volume_notifier(struct notifier_block *nb,
250 				 int ignore_existing);
251 int ubi_unregister_volume_notifier(struct notifier_block *nb);
252 #endif
253 
254 void ubi_close_volume(struct ubi_volume_desc *desc);
255 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
256 		 int len, int check);
257 int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl,
258 		   int offset, int len, int check);
259 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
260 		  int offset, int len);
261 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
262 		   int len);
263 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);
264 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);
265 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum);
266 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
267 int ubi_sync(int ubi_num);
268 int ubi_flush(int ubi_num, int vol_id, int lnum);
269 
270 /*
271  * This function is the same as the 'ubi_leb_read()' function, but it does not
272  * provide the checking capability.
273  */
ubi_read(struct ubi_volume_desc * desc,int lnum,char * buf,int offset,int len)274 static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf,
275 			   int offset, int len)
276 {
277 	return ubi_leb_read(desc, lnum, buf, offset, len, 0);
278 }
279 
280 /*
281  * This function is the same as the 'ubi_leb_read_sg()' function, but it does
282  * not provide the checking capability.
283  */
ubi_read_sg(struct ubi_volume_desc * desc,int lnum,struct ubi_sgl * sgl,int offset,int len)284 static inline int ubi_read_sg(struct ubi_volume_desc *desc, int lnum,
285 			      struct ubi_sgl *sgl, int offset, int len)
286 {
287 	return ubi_leb_read_sg(desc, lnum, sgl, offset, len, 0);
288 }
289 #endif /* !__LINUX_UBI_H__ */
290