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Diffstat (limited to 'drivers/mtd/ubi/ubi.h')
| -rw-r--r-- | drivers/mtd/ubi/ubi.h | 641 |
1 files changed, 641 insertions, 0 deletions
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h new file mode 100644 index 0000000..bf77a15 --- /dev/null +++ b/drivers/mtd/ubi/ubi.h @@ -0,0 +1,641 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * Copyright (c) Nokia Corporation, 2006, 2007 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +#ifndef __UBI_UBI_H__ +#define __UBI_UBI_H__ + +#ifdef UBI_LINUX +#include <linux/init.h> +#include <linux/types.h> +#include <linux/list.h> +#include <linux/rbtree.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/mutex.h> +#include <linux/rwsem.h> +#include <linux/spinlock.h> +#include <linux/fs.h> +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/string.h> +#include <linux/vmalloc.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/ubi.h> +#endif + +#include <linux/types.h> +#include <linux/list.h> +#include <linux/rbtree.h> +#include <linux/string.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/ubi.h> + +#include "ubi-media.h" +#include "scan.h" +#include "debug.h" + +/* Maximum number of supported UBI devices */ +#define UBI_MAX_DEVICES 32 + +/* UBI name used for character devices, sysfs, etc */ +#define UBI_NAME_STR "ubi" + +/* Normal UBI messages */ +#define ubi_msg(fmt, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__) +/* UBI warning messages */ +#define ubi_warn(fmt, ...) printk(KERN_WARNING "UBI warning: %s: " fmt "\n", \ + __func__, ##__VA_ARGS__) +/* UBI error messages */ +#define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \ + __func__, ##__VA_ARGS__) + +/* Lowest number PEBs reserved for bad PEB handling */ +#define MIN_RESEVED_PEBS 2 + +/* Background thread name pattern */ +#define UBI_BGT_NAME_PATTERN "ubi_bgt%dd" + +/* This marker in the EBA table means that the LEB is um-mapped */ +#define UBI_LEB_UNMAPPED -1 + +/* + * In case of errors, UBI tries to repeat the operation several times before + * returning error. The below constant defines how many times UBI re-tries. + */ +#define UBI_IO_RETRIES 3 + +/* + * Error codes returned by the I/O unit. + * + * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only + * 0xFF bytes + * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a + * valid erase counter header, and the rest are %0xFF bytes + * UBI_IO_BAD_EC_HDR: the erase counter header is corrupted (bad magic or CRC) + * UBI_IO_BAD_VID_HDR: the volume identifier header is corrupted (bad magic or + * CRC) + * UBI_IO_BITFLIPS: bit-flips were detected and corrected + */ +enum { + UBI_IO_PEB_EMPTY = 1, + UBI_IO_PEB_FREE, + UBI_IO_BAD_EC_HDR, + UBI_IO_BAD_VID_HDR, + UBI_IO_BITFLIPS +}; + +/** + * struct ubi_wl_entry - wear-leveling entry. + * @rb: link in the corresponding RB-tree + * @ec: erase counter + * @pnum: physical eraseblock number + * + * This data structure is used in the WL unit. Each physical eraseblock has a + * corresponding &struct wl_entry object which may be kept in different + * RB-trees. See WL unit for details. + */ +struct ubi_wl_entry { + struct rb_node rb; + int ec; + int pnum; +}; + +/** + * struct ubi_ltree_entry - an entry in the lock tree. + * @rb: links RB-tree nodes + * @vol_id: volume ID of the locked logical eraseblock + * @lnum: locked logical eraseblock number + * @users: how many tasks are using this logical eraseblock or wait for it + * @mutex: read/write mutex to implement read/write access serialization to + * the (@vol_id, @lnum) logical eraseblock + * + * This data structure is used in the EBA unit to implement per-LEB locking. + * When a logical eraseblock is being locked - corresponding + * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree). + * See EBA unit for details. + */ +struct ubi_ltree_entry { + struct rb_node rb; + int vol_id; + int lnum; + int users; + struct rw_semaphore mutex; +}; + +struct ubi_volume_desc; + +/** + * struct ubi_volume - UBI volume description data structure. + * @dev: device object to make use of the the Linux device model + * @cdev: character device object to create character device + * @ubi: reference to the UBI device description object + * @vol_id: volume ID + * @ref_count: volume reference count + * @readers: number of users holding this volume in read-only mode + * @writers: number of users holding this volume in read-write mode + * @exclusive: whether somebody holds this volume in exclusive mode + * + * @reserved_pebs: how many physical eraseblocks are reserved for this volume + * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) + * @usable_leb_size: logical eraseblock size without padding + * @used_ebs: how many logical eraseblocks in this volume contain data + * @last_eb_bytes: how many bytes are stored in the last logical eraseblock + * @used_bytes: how many bytes of data this volume contains + * @alignment: volume alignment + * @data_pad: how many bytes are not used at the end of physical eraseblocks to + * satisfy the requested alignment + * @name_len: volume name length + * @name: volume name + * + * @upd_ebs: how many eraseblocks are expected to be updated + * @ch_lnum: LEB number which is being changing by the atomic LEB change + * operation + * @ch_dtype: data persistency type which is being changing by the atomic LEB + * change operation + * @upd_bytes: how many bytes are expected to be received for volume update or + * atomic LEB change + * @upd_received: how many bytes were already received for volume update or + * atomic LEB change + * @upd_buf: update buffer which is used to collect update data or data for + * atomic LEB change + * + * @eba_tbl: EBA table of this volume (LEB->PEB mapping) + * @checked: %1 if this static volume was checked + * @corrupted: %1 if the volume is corrupted (static volumes only) + * @upd_marker: %1 if the update marker is set for this volume + * @updating: %1 if the volume is being updated + * @changing_leb: %1 if the atomic LEB change ioctl command is in progress + * + * @gluebi_desc: gluebi UBI volume descriptor + * @gluebi_refcount: reference count of the gluebi MTD device + * @gluebi_mtd: MTD device description object of the gluebi MTD device + * + * The @corrupted field indicates that the volume's contents is corrupted. + * Since UBI protects only static volumes, this field is not relevant to + * dynamic volumes - it is user's responsibility to assure their data + * integrity. + * + * The @upd_marker flag indicates that this volume is either being updated at + * the moment or is damaged because of an unclean reboot. + */ +struct ubi_volume { + struct device dev; + struct cdev cdev; + struct ubi_device *ubi; + int vol_id; + int ref_count; + int readers; + int writers; + int exclusive; + + int reserved_pebs; + int vol_type; + int usable_leb_size; + int used_ebs; + int last_eb_bytes; + long long used_bytes; + int alignment; + int data_pad; + int name_len; + char name[UBI_VOL_NAME_MAX+1]; + + int upd_ebs; + int ch_lnum; + int ch_dtype; + long long upd_bytes; + long long upd_received; + void *upd_buf; + + int *eba_tbl; + unsigned int checked:1; + unsigned int corrupted:1; + unsigned int upd_marker:1; + unsigned int updating:1; + unsigned int changing_leb:1; + +#ifdef CONFIG_MTD_UBI_GLUEBI + /* + * Gluebi-related stuff may be compiled out. + * TODO: this should not be built into UBI but should be a separate + * ubimtd driver which works on top of UBI and emulates MTD devices. + */ + struct ubi_volume_desc *gluebi_desc; + int gluebi_refcount; + struct mtd_info gluebi_mtd; +#endif +}; + +/** + * struct ubi_volume_desc - descriptor of the UBI volume returned when it is + * opened. + * @vol: reference to the corresponding volume description object + * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE) + */ +struct ubi_volume_desc { + struct ubi_volume *vol; + int mode; +}; + +struct ubi_wl_entry; + +/** + * struct ubi_device - UBI device description structure + * @dev: UBI device object to use the the Linux device model + * @cdev: character device object to create character device + * @ubi_num: UBI device number + * @ubi_name: UBI device name + * @vol_count: number of volumes in this UBI device + * @volumes: volumes of this UBI device + * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs, + * @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count, + * @vol->readers, @vol->writers, @vol->exclusive, + * @vol->ref_count, @vol->mapping and @vol->eba_tbl. + * @ref_count: count of references on the UBI device + * + * @rsvd_pebs: count of reserved physical eraseblocks + * @avail_pebs: count of available physical eraseblocks + * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB + * handling + * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling + * + * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end + * of UBI ititializetion + * @vtbl_slots: how many slots are available in the volume table + * @vtbl_size: size of the volume table in bytes + * @vtbl: in-RAM volume table copy + * @volumes_mutex: protects on-flash volume table and serializes volume + * changes, like creation, deletion, update, resize + * + * @max_ec: current highest erase counter value + * @mean_ec: current mean erase counter value + * + * @global_sqnum: global sequence number + * @ltree_lock: protects the lock tree and @global_sqnum + * @ltree: the lock tree + * @alc_mutex: serializes "atomic LEB change" operations + * + * @used: RB-tree of used physical eraseblocks + * @free: RB-tree of free physical eraseblocks + * @scrub: RB-tree of physical eraseblocks which need scrubbing + * @prot: protection trees + * @prot.pnum: protection tree indexed by physical eraseblock numbers + * @prot.aec: protection tree indexed by absolute erase counter value + * @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from, + * @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works + * fields + * @move_mutex: serializes eraseblock moves + * @wl_scheduled: non-zero if the wear-leveling was scheduled + * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any + * physical eraseblock + * @abs_ec: absolute erase counter + * @move_from: physical eraseblock from where the data is being moved + * @move_to: physical eraseblock where the data is being moved to + * @move_to_put: if the "to" PEB was put + * @works: list of pending works + * @works_count: count of pending works + * @bgt_thread: background thread description object + * @thread_enabled: if the background thread is enabled + * @bgt_name: background thread name + * + * @flash_size: underlying MTD device size (in bytes) + * @peb_count: count of physical eraseblocks on the MTD device + * @peb_size: physical eraseblock size + * @bad_peb_count: count of bad physical eraseblocks + * @good_peb_count: count of good physical eraseblocks + * @min_io_size: minimal input/output unit size of the underlying MTD device + * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers + * @ro_mode: if the UBI device is in read-only mode + * @leb_size: logical eraseblock size + * @leb_start: starting offset of logical eraseblocks within physical + * eraseblocks + * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size + * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size + * @vid_hdr_offset: starting offset of the volume identifier header (might be + * unaligned) + * @vid_hdr_aloffset: starting offset of the VID header aligned to + * @hdrs_min_io_size + * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset + * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or + * not + * @mtd: MTD device descriptor + * + * @peb_buf1: a buffer of PEB size used for different purposes + * @peb_buf2: another buffer of PEB size used for different purposes + * @buf_mutex: proptects @peb_buf1 and @peb_buf2 + * @dbg_peb_buf: buffer of PEB size used for debugging + * @dbg_buf_mutex: proptects @dbg_peb_buf + */ +struct ubi_device { + struct cdev cdev; + struct device dev; + int ubi_num; + char ubi_name[sizeof(UBI_NAME_STR)+5]; + int vol_count; + struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT]; + spinlock_t volumes_lock; + int ref_count; + + int rsvd_pebs; + int avail_pebs; + int beb_rsvd_pebs; + int beb_rsvd_level; + + int autoresize_vol_id; + int vtbl_slots; + int vtbl_size; + struct ubi_vtbl_record *vtbl; + struct mutex volumes_mutex; + + int max_ec; + /* TODO: mean_ec is not updated run-time, fix */ + int mean_ec; + + /* EBA unit's stuff */ + unsigned long long global_sqnum; + spinlock_t ltree_lock; + struct rb_root ltree; + struct mutex alc_mutex; + + /* Wear-leveling unit's stuff */ + struct rb_root used; + struct rb_root free; + struct rb_root scrub; + struct { + struct rb_root pnum; + struct rb_root aec; + } prot; + spinlock_t wl_lock; + struct mutex move_mutex; + struct rw_semaphore work_sem; + int wl_scheduled; + struct ubi_wl_entry **lookuptbl; + unsigned long long abs_ec; + struct ubi_wl_entry *move_from; + struct ubi_wl_entry *move_to; + int move_to_put; + struct list_head works; + int works_count; + struct task_struct *bgt_thread; + int thread_enabled; + char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2]; + + /* I/O unit's stuff */ + long long flash_size; + int peb_count; + int peb_size; + int bad_peb_count; + int good_peb_count; + int min_io_size; + int hdrs_min_io_size; + int ro_mode; + int leb_size; + int leb_start; + int ec_hdr_alsize; + int vid_hdr_alsize; + int vid_hdr_offset; + int vid_hdr_aloffset; + int vid_hdr_shift; + int bad_allowed; + struct mtd_info *mtd; + + void *peb_buf1; + void *peb_buf2; + struct mutex buf_mutex; + struct mutex ckvol_mutex; +#ifdef CONFIG_MTD_UBI_DEBUG + void *dbg_peb_buf; + struct mutex dbg_buf_mutex; +#endif +}; + +extern struct kmem_cache *ubi_wl_entry_slab; +extern struct file_operations ubi_ctrl_cdev_operations; +extern struct file_operations ubi_cdev_operations; +extern struct file_operations ubi_vol_cdev_operations; +extern struct class *ubi_class; +extern struct mutex ubi_devices_mutex; + +/* vtbl.c */ +int ubi_change_vtbl_record(struct ubi_device *ubi, int idx, + struct ubi_vtbl_record *vtbl_rec); +int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si); + +/* vmt.c */ +int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req); +int ubi_remove_volume(struct ubi_volume_desc *desc); +int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs); +int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol); +void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol); + +/* upd.c */ +int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol, + long long bytes); +int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol, + const void __user *buf, int count); +int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol, + const struct ubi_leb_change_req *req); +int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol, + const void __user *buf, int count); + +/* misc.c */ +int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length); +int ubi_check_volume(struct ubi_device *ubi, int vol_id); +void ubi_calculate_reserved(struct ubi_device *ubi); + +/* gluebi.c */ +#ifdef CONFIG_MTD_UBI_GLUEBI +int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol); +int ubi_destroy_gluebi(struct ubi_volume *vol); +void ubi_gluebi_updated(struct ubi_volume *vol); +#else +#define ubi_create_gluebi(ubi, vol) 0 +#define ubi_destroy_gluebi(vol) 0 +#define ubi_gluebi_updated(vol) +#endif + +/* eba.c */ +int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol, + int lnum); +int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, + void *buf, int offset, int len, int check); +int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, + const void *buf, int offset, int len, int dtype); +int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol, + int lnum, const void *buf, int len, int dtype, + int used_ebs); +int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol, + int lnum, const void *buf, int len, int dtype); +int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to, + struct ubi_vid_hdr *vid_hdr); +int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si); +void ubi_eba_close(const struct ubi_device *ubi); + +/* wl.c */ +int ubi_wl_get_peb(struct ubi_device *ubi, int dtype); +int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture); +int ubi_wl_flush(struct ubi_device *ubi); +int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum); +int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si); +void ubi_wl_close(struct ubi_device *ubi); +int ubi_thread(void *u); + +/* io.c */ +int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset, + int len); +int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset, + int len); +int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture); +int ubi_io_is_bad(const struct ubi_device *ubi, int pnum); +int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum); +int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum, + struct ubi_ec_hdr *ec_hdr, int verbose); +int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum, + struct ubi_ec_hdr *ec_hdr); +int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum, + struct ubi_vid_hdr *vid_hdr, int verbose); +int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum, + struct ubi_vid_hdr *vid_hdr); + +/* build.c */ +int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset); +int ubi_detach_mtd_dev(int ubi_num, int anyway); +struct ubi_device *ubi_get_device(int ubi_num); +void ubi_put_device(struct ubi_device *ubi); +struct ubi_device *ubi_get_by_major(int major); +int ubi_major2num(int major); + +/* + * ubi_rb_for_each_entry - walk an RB-tree. + * @rb: a pointer to type 'struct rb_node' to to use as a loop counter + * @pos: a pointer to RB-tree entry type to use as a loop counter + * @root: RB-tree's root + * @member: the name of the 'struct rb_node' within the RB-tree entry + */ +#define ubi_rb_for_each_entry(rb, pos, root, member) \ + for (rb = rb_first(root), \ + pos = (rb ? container_of(rb, typeof(*pos), member) : NULL); \ + rb; \ + rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member)) + +/** + * ubi_zalloc_vid_hdr - allocate a volume identifier header object. + * @ubi: UBI device description object + * @gfp_flags: GFP flags to allocate with + * + * This function returns a pointer to the newly allocated and zero-filled + * volume identifier header object in case of success and %NULL in case of + * failure. + */ +static inline struct ubi_vid_hdr * +ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags) +{ + void *vid_hdr; + + vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags); + if (!vid_hdr) + return NULL; + + /* + * VID headers may be stored at un-aligned flash offsets, so we shift + * the pointer. + */ + return vid_hdr + ubi->vid_hdr_shift; +} + +/** + * ubi_free_vid_hdr - free a volume identifier header object. + * @ubi: UBI device description object + * @vid_hdr: the object to free + */ +static inline void ubi_free_vid_hdr(const struct ubi_device *ubi, + struct ubi_vid_hdr *vid_hdr) +{ + void *p = vid_hdr; + + if (!p) + return; + + kfree(p - ubi->vid_hdr_shift); +} + +/* + * This function is equivalent to 'ubi_io_read()', but @offset is relative to + * the beginning of the logical eraseblock, not to the beginning of the + * physical eraseblock. + */ +static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf, + int pnum, int offset, int len) +{ + ubi_assert(offset >= 0); + return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len); +} + +/* + * This function is equivalent to 'ubi_io_write()', but @offset is relative to + * the beginning of the logical eraseblock, not to the beginning of the + * physical eraseblock. + */ +static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf, + int pnum, int offset, int len) +{ + ubi_assert(offset >= 0); + return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len); +} + +/** + * ubi_ro_mode - switch to read-only mode. + * @ubi: UBI device description object + */ +static inline void ubi_ro_mode(struct ubi_device *ubi) +{ + if (!ubi->ro_mode) { + ubi->ro_mode = 1; + ubi_warn("switch to read-only mode"); + } +} + +/** + * vol_id2idx - get table index by volume ID. + * @ubi: UBI device description object + * @vol_id: volume ID + */ +static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id) +{ + if (vol_id >= UBI_INTERNAL_VOL_START) + return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots; + else + return vol_id; +} + +/** + * idx2vol_id - get volume ID by table index. + * @ubi: UBI device description object + * @idx: table index + */ +static inline int idx2vol_id(const struct ubi_device *ubi, int idx) +{ + if (idx >= ubi->vtbl_slots) + return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START; + else + return idx; +} + +#endif /* !__UBI_UBI_H__ */ |