ubi.h 10.0 KB

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