/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright (c) International Business Machines Corp., 2006 * * Author: Artem Bityutskiy (Битюцкий Артём) */ #ifndef __LINUX_UBI_H__ #define __LINUX_UBI_H__ #include <linux/ioctl.h> #include <linux/types.h> #include <linux/scatterlist.h> #include <mtd/ubi-user.h> /* All voumes/LEBs */ #define UBI_ALL … /* * Maximum number of scatter gather list entries, * we use only 64 to have a lower memory foot print. */ #define UBI_MAX_SG_COUNT … /* * enum ubi_open_mode - UBI volume open mode constants. * * UBI_READONLY: read-only mode * UBI_READWRITE: read-write mode * UBI_EXCLUSIVE: exclusive mode * UBI_METAONLY: modify only the volume meta-data, * i.e. the data stored in the volume table, but not in any of volume LEBs. */ enum { … }; /** * struct ubi_volume_info - UBI volume description data structure. * @vol_id: volume ID * @ubi_num: UBI device number this volume belongs to * @size: how many physical eraseblocks are reserved for this volume * @used_bytes: how many bytes of data this volume contains * @used_ebs: how many physical eraseblocks of this volume actually contain any * data * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) * @corrupted: non-zero if the volume is corrupted (static volumes only) * @upd_marker: non-zero if the volume has update marker set * @alignment: volume alignment * @usable_leb_size: how many bytes are available in logical eraseblocks of * this volume * @name_len: volume name length * @name: volume name * @cdev: UBI volume character device major and minor numbers * * The @corrupted flag is only relevant to static volumes and is always zero * for dynamic ones. This is because UBI does not care about dynamic volume * data protection and only cares about protecting static volume data. * * The @upd_marker flag is set if the volume update operation was interrupted. * Before touching the volume data during the update operation, UBI first sets * the update marker flag for this volume. If the volume update operation was * further interrupted, the update marker indicates this. If the update marker * is set, the contents of the volume is certainly damaged and a new volume * update operation has to be started. * * To put it differently, @corrupted and @upd_marker fields have different * semantics: * o the @corrupted flag means that this static volume is corrupted for some * reasons, but not because an interrupted volume update * o the @upd_marker field means that the volume is damaged because of an * interrupted update operation. * * I.e., the @corrupted flag is never set if the @upd_marker flag is set. * * The @used_bytes and @used_ebs fields are only really needed for static * volumes and contain the number of bytes stored in this static volume and how * many eraseblock this data occupies. In case of dynamic volumes, the * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs * field is equivalent to @size. * * In general, logical eraseblock size is a property of the UBI device, not * of the UBI volume. Indeed, the logical eraseblock size depends on the * physical eraseblock size and on how much bytes UBI headers consume. But * because of the volume alignment (@alignment), the usable size of logical * eraseblocks if a volume may be less. The following equation is true: * @usable_leb_size = LEB size - (LEB size mod @alignment), * where LEB size is the logical eraseblock size defined by the UBI device. * * The alignment is multiple to the minimal flash input/output unit size or %1 * if all the available space is used. * * To put this differently, alignment may be considered is a way to change * volume logical eraseblock sizes. */ struct ubi_volume_info { … }; /** * struct ubi_sgl - UBI scatter gather list data structure. * @list_pos: current position in @sg[] * @page_pos: current position in @sg[@list_pos] * @sg: the scatter gather list itself * * ubi_sgl is a wrapper around a scatter list which keeps track of the * current position in the list and the current list item such that * it can be used across multiple ubi_leb_read_sg() calls. */ struct ubi_sgl { … }; /** * ubi_sgl_init - initialize an UBI scatter gather list data structure. * @usgl: the UBI scatter gather struct itself * * Please note that you still have to use sg_init_table() or any adequate * function to initialize the unterlaying struct scatterlist. */ static inline void ubi_sgl_init(struct ubi_sgl *usgl) { … } /** * struct ubi_device_info - UBI device description data structure. * @ubi_num: ubi device number * @leb_size: logical eraseblock size on this UBI device * @leb_start: starting offset of logical eraseblocks within physical * eraseblocks * @min_io_size: minimal I/O unit size * @max_write_size: maximum amount of bytes the underlying flash can write at a * time (MTD write buffer size) * @ro_mode: if this device is in read-only mode * @cdev: UBI character device major and minor numbers * * Note, @leb_size is the logical eraseblock size offered by the UBI device. * Volumes of this UBI device may have smaller logical eraseblock size if their * alignment is not equivalent to %1. * * The @max_write_size field describes flash write maximum write unit. For * example, NOR flash allows for changing individual bytes, so @min_io_size is * %1. However, it does not mean than NOR flash has to write data byte-by-byte. * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when * writing large chunks of data, they write 64-bytes at a time. Obviously, this * improves write throughput. * * Also, the MTD device may have N interleaved (striped) flash chips * underneath, in which case @min_io_size can be physical min. I/O size of * single flash chip, while @max_write_size can be N * @min_io_size. * * The @max_write_size field is always greater or equivalent to @min_io_size. * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND * page size. */ struct ubi_device_info { … }; /* * Volume notification types. * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a * volume was created) * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached * or a volume was removed) * @UBI_VOLUME_RESIZED: a volume has been re-sized * @UBI_VOLUME_RENAMED: a volume has been re-named * @UBI_VOLUME_SHUTDOWN: a volume is going to removed, shutdown users * @UBI_VOLUME_UPDATED: data has been written to a volume * * These constants define which type of event has happened when a volume * notification function is invoked. */ enum { … }; /* * struct ubi_notification - UBI notification description structure. * @di: UBI device description object * @vi: UBI volume description object * * UBI notifiers are called with a pointer to an object of this type. The * object describes the notification. Namely, it provides a description of the * UBI device and UBI volume the notification informs about. */ struct ubi_notification { … }; /* UBI descriptor given to users when they open UBI volumes */ struct ubi_volume_desc; int ubi_get_device_info(int ubi_num, struct ubi_device_info *di); void ubi_get_volume_info(struct ubi_volume_desc *desc, struct ubi_volume_info *vi); struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode); struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, int mode); struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode); int ubi_register_volume_notifier(struct notifier_block *nb, int ignore_existing); int ubi_unregister_volume_notifier(struct notifier_block *nb); void ubi_close_volume(struct ubi_volume_desc *desc); int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, int len, int check); int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl, int offset, int len, int check); int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, int offset, int len); int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, int len); int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum); int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum); int ubi_leb_map(struct ubi_volume_desc *desc, int lnum); int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum); int ubi_sync(int ubi_num); int ubi_flush(int ubi_num, int vol_id, int lnum); /* * This function is the same as the 'ubi_leb_read()' function, but it does not * provide the checking capability. */ static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, int len) { … } /* * This function is the same as the 'ubi_leb_read_sg()' function, but it does * not provide the checking capability. */ static inline int ubi_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl, int offset, int len) { … } #endif /* !__LINUX_UBI_H__ */
Codebase Browser
linux