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Diffstat (limited to 'include/linux/mtd/ubi.h')
| -rw-r--r-- | include/linux/mtd/ubi.h | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/include/linux/mtd/ubi.h b/include/linux/mtd/ubi.h new file mode 100644 index 000000000..7d48ea368 --- /dev/null +++ b/include/linux/mtd/ubi.h @@ -0,0 +1,271 @@ +/* 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 -1 + +/* + * Maximum number of scatter gather list entries, + * we use only 64 to have a lower memory foot print. + */ +#define UBI_MAX_SG_COUNT 64 + +/* + * 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 { + UBI_READONLY = 1, + UBI_READWRITE, + UBI_EXCLUSIVE, + UBI_METAONLY +}; + +/** + * 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 { + int ubi_num; + int vol_id; + int size; + long long used_bytes; + int used_ebs; + int vol_type; + int corrupted; + int upd_marker; + int alignment; + int usable_leb_size; + int name_len; + const char *name; + dev_t cdev; +}; + +/** + * 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 { + int list_pos; + int page_pos; + struct scatterlist sg[UBI_MAX_SG_COUNT]; +}; + +/** + * 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) +{ + usgl->list_pos = 0; + usgl->page_pos = 0; +} + +/** + * 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 { + int ubi_num; + int leb_size; + int leb_start; + int min_io_size; + int max_write_size; + int ro_mode; + dev_t cdev; +}; + +/* + * 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_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 { + UBI_VOLUME_ADDED, + UBI_VOLUME_REMOVED, + UBI_VOLUME_RESIZED, + UBI_VOLUME_RENAMED, + UBI_VOLUME_UPDATED, +}; + +/* + * 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 { + struct ubi_device_info di; + struct ubi_volume_info vi; +}; + +/* 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) +{ + return ubi_leb_read(desc, lnum, buf, offset, len, 0); +} + +/* + * 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) +{ + return ubi_leb_read_sg(desc, lnum, sgl, offset, len, 0); +} +#endif /* !__LINUX_UBI_H__ */ |