drivers/mtd/ubi/ubi.h

   1 /*
   2  * Copyright (c) International Business Machines Corp., 2006
   3  * Copyright (c) Nokia Corporation, 2006, 2007
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  13  * the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18  *
  19  * Author: Artem Bityutskiy (Битюцкий Артём)
  20  */
  21
  22 #ifndef __UBI_UBI_H__
  23 #define __UBI_UBI_H__
  24
  25 #include <linux/init.h>
  26 #include <linux/types.h>
  27 #include <linux/list.h>
  28 #include <linux/rbtree.h>
  29 #include <linux/sched.h>
  30 #include <linux/wait.h>
  31 #include <linux/mutex.h>
  32 #include <linux/rwsem.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/fs.h>
  35 #include <linux/cdev.h>
  36 #include <linux/device.h>
  37 #include <linux/slab.h>
  38 #include <linux/string.h>
  39 #include <linux/vmalloc.h>
  40 #include <linux/notifier.h>
  41 #include <linux/mtd/mtd.h>
  42 #include <linux/mtd/ubi.h>
  43
  44 #include "ubi-media.h"
  45 #include "scan.h"
  46 #include "debug.h"
  47
  48 /* Maximum number of supported UBI devices */
  49 #define UBI_MAX_DEVICES 32
  50
  51 /* UBI name used for character devices, sysfs, etc */
  52 #define UBI_NAME_STR "ubi"
  53
  54 /* Normal UBI messages */
  55 #define ubi_msg(fmt, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__)
  56 /* UBI warning messages */
  57 #define ubi_warn(fmt, ...) printk(KERN_WARNING "UBI warning: %s: " fmt "\n", \
  58                                   __func__, ##__VA_ARGS__)
  59 /* UBI error messages */
  60 #define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \
  61                                  __func__, ##__VA_ARGS__)
  62
  63 /* Lowest number PEBs reserved for bad PEB handling */
  64 #define MIN_RESEVED_PEBS 2
  65
  66 /* Background thread name pattern */
  67 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
  68
  69 /* This marker in the EBA table means that the LEB is um-mapped */
  70 #define UBI_LEB_UNMAPPED -1
  71
  72 /*
  73  * In case of errors, UBI tries to repeat the operation several times before
  74  * returning error. The below constant defines how many times UBI re-tries.
  75  */
  76 #define UBI_IO_RETRIES 3
  77
  78 /*
  79  * Length of the protection queue. The length is effectively equivalent to the
  80  * number of (global) erase cycles PEBs are protected from the wear-leveling
  81  * worker.
  82  */
  83 #define UBI_PROT_QUEUE_LEN 10
  84
  85 /*
  86  * Error codes returned by the I/O sub-system.
  87  *
  88  * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only
  89  *                   %0xFF bytes
  90  * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a
  91  *                  valid erase counter header, and the rest are %0xFF bytes
  92  * UBI_IO_BAD_EC_HDR: the erase counter header is corrupted (bad magic or CRC)
  93  * UBI_IO_BAD_VID_HDR: the volume identifier header is corrupted (bad magic or
  94  *                     CRC)
  95  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
  96  */
  97 enum {
  98         UBI_IO_PEB_EMPTY = 1,
  99         UBI_IO_PEB_FREE,
 100         UBI_IO_BAD_EC_HDR,
 101         UBI_IO_BAD_VID_HDR,
 102         UBI_IO_BITFLIPS
 103 };
 104
 105 /*
 106  * Return codes of the 'ubi_eba_copy_leb()' function.
 107  *
 108  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
 109  *                   PEB was put meanwhile, or there is I/O on the source PEB
 110  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
 111  *                     PEB
 112  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
 113  *                     PEB
 114  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
 115  *                     PEB
 116  * MOVE_CANCEL_BITFLIPS: canceled because a bit-flip was detected in the
 117  *                       target PEB
 118  */
 119 enum {
 120         MOVE_CANCEL_RACE = 1,
 121         MOVE_SOURCE_RD_ERR,
 122         MOVE_TARGET_RD_ERR,
 123         MOVE_TARGET_WR_ERR,
 124         MOVE_CANCEL_BITFLIPS,
 125 };
 126
 127 /**
 128  * struct ubi_wl_entry - wear-leveling entry.
 129  * @u.rb: link in the corresponding (free/used) RB-tree
 130  * @u.list: link in the protection queue
 131  * @ec: erase counter
 132  * @pnum: physical eraseblock number
 133  *
 134  * This data structure is used in the WL sub-system. Each physical eraseblock
 135  * has a corresponding &struct wl_entry object which may be kept in different
 136  * RB-trees. See WL sub-system for details.
 137  */
 138 struct ubi_wl_entry {
 139         union {
 140                 struct rb_node rb;
 141                 struct list_head list;
 142         } u;
 143         int ec;
 144         int pnum;
 145 };
 146
 147 /**
 148  * struct ubi_ltree_entry - an entry in the lock tree.
 149  * @rb: links RB-tree nodes
 150  * @vol_id: volume ID of the locked logical eraseblock
 151  * @lnum: locked logical eraseblock number
 152  * @users: how many tasks are using this logical eraseblock or wait for it
 153  * @mutex: read/write mutex to implement read/write access serialization to
 154  *         the (@vol_id, @lnum) logical eraseblock
 155  *
 156  * This data structure is used in the EBA sub-system to implement per-LEB
 157  * locking. When a logical eraseblock is being locked - corresponding
 158  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
 159  * See EBA sub-system for details.
 160  */
 161 struct ubi_ltree_entry {
 162         struct rb_node rb;
 163         int vol_id;
 164         int lnum;
 165         int users;
 166         struct rw_semaphore mutex;
 167 };
 168
 169 /**
 170  * struct ubi_rename_entry - volume re-name description data structure.
 171  * @new_name_len: new volume name length
 172  * @new_name: new volume name
 173  * @remove: if not zero, this volume should be removed, not re-named
 174  * @desc: descriptor of the volume
 175  * @list: links re-name entries into a list
 176  *
 177  * This data structure is utilized in the multiple volume re-name code. Namely,
 178  * UBI first creates a list of &struct ubi_rename_entry objects from the
 179  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
 180  * the job.
 181  */
 182 struct ubi_rename_entry {
 183         int new_name_len;
 184         char new_name[UBI_VOL_NAME_MAX + 1];
 185         int remove;
 186         struct ubi_volume_desc *desc;
 187         struct list_head list;
 188 };
 189
 190 struct ubi_volume_desc;
 191
 192 /**
 193  * struct ubi_volume - UBI volume description data structure.
 194  * @dev: device object to make use of the the Linux device model
 195  * @cdev: character device object to create character device
 196  * @ubi: reference to the UBI device description object
 197  * @vol_id: volume ID
 198  * @ref_count: volume reference count
 199  * @readers: number of users holding this volume in read-only mode
 200  * @writers: number of users holding this volume in read-write mode
 201  * @exclusive: whether somebody holds this volume in exclusive mode
 202  *
 203  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
 204  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
 205  * @usable_leb_size: logical eraseblock size without padding
 206  * @used_ebs: how many logical eraseblocks in this volume contain data
 207  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
 208  * @used_bytes: how many bytes of data this volume contains
 209  * @alignment: volume alignment
 210  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
 211  *            satisfy the requested alignment
 212  * @name_len: volume name length
 213  * @name: volume name
 214  *
 215  * @upd_ebs: how many eraseblocks are expected to be updated
 216  * @ch_lnum: LEB number which is being changing by the atomic LEB change
 217  *           operation
 218  * @ch_dtype: data persistency type which is being changing by the atomic LEB
 219  *            change operation
 220  * @upd_bytes: how many bytes are expected to be received for volume update or
 221  *             atomic LEB change
 222  * @upd_received: how many bytes were already received for volume update or
 223  *                atomic LEB change
 224  * @upd_buf: update buffer which is used to collect update data or data for
 225  *           atomic LEB change
 226  *
 227  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
 228  * @checked: %1 if this static volume was checked
 229  * @corrupted: %1 if the volume is corrupted (static volumes only)
 230  * @upd_marker: %1 if the update marker is set for this volume
 231  * @updating: %1 if the volume is being updated
 232  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
 233  * @direct_writes: %1 if direct writes are enabled for this volume
 234  *
 235  * The @corrupted field indicates that the volume's contents is corrupted.
 236  * Since UBI protects only static volumes, this field is not relevant to
 237  * dynamic volumes - it is user's responsibility to assure their data
 238  * integrity.
 239  *
 240  * The @upd_marker flag indicates that this volume is either being updated at
 241  * the moment or is damaged because of an unclean reboot.
 242  */
 243 struct ubi_volume {
 244         struct device dev;
 245         struct cdev cdev;
 246         struct ubi_device *ubi;
 247         int vol_id;
 248         int ref_count;
 249         int readers;
 250         int writers;
 251         int exclusive;
 252
 253         int reserved_pebs;
 254         int vol_type;
 255         int usable_leb_size;
 256         int used_ebs;
 257         int last_eb_bytes;
 258         long long used_bytes;
 259         int alignment;
 260         int data_pad;
 261         int name_len;
 262         char name[UBI_VOL_NAME_MAX + 1];
 263
 264         int upd_ebs;
 265         int ch_lnum;
 266         int ch_dtype;
 267         long long upd_bytes;
 268         long long upd_received;
 269         void *upd_buf;
 270
 271         int *eba_tbl;
 272         unsigned int checked:1;
 273         unsigned int corrupted:1;
 274         unsigned int upd_marker:1;
 275         unsigned int updating:1;
 276         unsigned int changing_leb:1;
 277         unsigned int direct_writes:1;
 278 };
 279
 280 /**
 281  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
 282  * @vol: reference to the corresponding volume description object
 283  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
 284  */
 285 struct ubi_volume_desc {
 286         struct ubi_volume *vol;
 287         int mode;
 288 };
 289
 290 struct ubi_wl_entry;
 291
 292 /**
 293  * struct ubi_device - UBI device description structure
 294  * @dev: UBI device object to use the the Linux device model
 295  * @cdev: character device object to create character device
 296  * @ubi_num: UBI device number
 297  * @ubi_name: UBI device name
 298  * @vol_count: number of volumes in this UBI device
 299  * @volumes: volumes of this UBI device
 300  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
 301  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
 302  *                @vol->readers, @vol->writers, @vol->exclusive,
 303  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
 304  * @ref_count: count of references on the UBI device
 305  * @image_seq: image sequence number recorded on EC headers
 306  *
 307  * @rsvd_pebs: count of reserved physical eraseblocks
 308  * @avail_pebs: count of available physical eraseblocks
 309  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
 310  *                 handling
 311  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
 312  *
 313  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
 314  *                     of UBI initialization
 315  * @vtbl_slots: how many slots are available in the volume table
 316  * @vtbl_size: size of the volume table in bytes
 317  * @vtbl: in-RAM volume table copy
 318  * @device_mutex: protects on-flash volume table and serializes volume
 319  *                creation, deletion, update, re-size, re-name and set
 320  *                property
 321  *
 322  * @max_ec: current highest erase counter value
 323  * @mean_ec: current mean erase counter value
 324  *
 325  * @global_sqnum: global sequence number
 326  * @ltree_lock: protects the lock tree and @global_sqnum
 327  * @ltree: the lock tree
 328  * @alc_mutex: serializes "atomic LEB change" operations
 329  *
 330  * @used: RB-tree of used physical eraseblocks
 331  * @erroneous: RB-tree of erroneous used physical eraseblocks
 332  * @free: RB-tree of free physical eraseblocks
 333  * @scrub: RB-tree of physical eraseblocks which need scrubbing
 334  * @pq: protection queue (contain physical eraseblocks which are temporarily
 335  *      protected from the wear-leveling worker)
 336  * @pq_head: protection queue head
 337  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
 338  *           @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
 339  *           @erroneous, and @erroneous_peb_count fields
 340  * @move_mutex: serializes eraseblock moves
 341  * @work_sem: synchronizes the WL worker with use tasks
 342  * @wl_scheduled: non-zero if the wear-leveling was scheduled
 343  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
 344  *             physical eraseblock
 345  * @move_from: physical eraseblock from where the data is being moved
 346  * @move_to: physical eraseblock where the data is being moved to
 347  * @move_to_put: if the "to" PEB was put
 348  * @works: list of pending works
 349  * @works_count: count of pending works
 350  * @bgt_thread: background thread description object
 351  * @thread_enabled: if the background thread is enabled
 352  * @bgt_name: background thread name
 353  *
 354  * @flash_size: underlying MTD device size (in bytes)
 355  * @peb_count: count of physical eraseblocks on the MTD device
 356  * @peb_size: physical eraseblock size
 357  * @bad_peb_count: count of bad physical eraseblocks
 358  * @good_peb_count: count of good physical eraseblocks
 359  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
 360  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
 361  * @min_io_size: minimal input/output unit size of the underlying MTD device
 362  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
 363  * @ro_mode: if the UBI device is in read-only mode
 364  * @leb_size: logical eraseblock size
 365  * @leb_start: starting offset of logical eraseblocks within physical
 366  *             eraseblocks
 367  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
 368  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
 369  * @vid_hdr_offset: starting offset of the volume identifier header (might be
 370  *                  unaligned)
 371  * @vid_hdr_aloffset: starting offset of the VID header aligned to
 372  * @hdrs_min_io_size
 373  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
 374  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
 375  *               not
 376  * @nor_flash: non-zero if working on top of NOR flash
 377  * @mtd: MTD device descriptor
 378  *
 379  * @peb_buf1: a buffer of PEB size used for different purposes
 380  * @peb_buf2: another buffer of PEB size used for different purposes
 381  * @buf_mutex: protects @peb_buf1 and @peb_buf2
 382  * @ckvol_mutex: serializes static volume checking when opening
 383  * @dbg_peb_buf: buffer of PEB size used for debugging
 384  * @dbg_buf_mutex: protects @dbg_peb_buf
 385  */
 386 struct ubi_device {
 387         struct cdev cdev;
 388         struct device dev;
 389         int ubi_num;
 390         char ubi_name[sizeof(UBI_NAME_STR)+5];
 391         int vol_count;
 392         struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
 393         spinlock_t volumes_lock;
 394         int ref_count;
 395         int image_seq;
 396
 397         int rsvd_pebs;
 398         int avail_pebs;
 399         int beb_rsvd_pebs;
 400         int beb_rsvd_level;
 401
 402         int autoresize_vol_id;
 403         int vtbl_slots;
 404         int vtbl_size;
 405         struct ubi_vtbl_record *vtbl;
 406         struct mutex device_mutex;
 407
 408         int max_ec;
 409         /* Note, mean_ec is not updated run-time - should be fixed */
 410         int mean_ec;
 411
 412         /* EBA sub-system's stuff */
 413         unsigned long long global_sqnum;
 414         spinlock_t ltree_lock;
 415         struct rb_root ltree;
 416         struct mutex alc_mutex;
 417
 418         /* Wear-leveling sub-system's stuff */
 419         struct rb_root used;
 420         struct rb_root erroneous;
 421         struct rb_root free;
 422         struct rb_root scrub;
 423         struct list_head pq[UBI_PROT_QUEUE_LEN];
 424         int pq_head;
 425         spinlock_t wl_lock;
 426         struct mutex move_mutex;
 427         struct rw_semaphore work_sem;
 428         int wl_scheduled;
 429         struct ubi_wl_entry **lookuptbl;
 430         struct ubi_wl_entry *move_from;
 431         struct ubi_wl_entry *move_to;
 432         int move_to_put;
 433         struct list_head works;
 434         int works_count;
 435         struct task_struct *bgt_thread;
 436         int thread_enabled;
 437         char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
 438
 439         /* I/O sub-system's stuff */
 440         long long flash_size;
 441         int peb_count;
 442         int peb_size;
 443         int bad_peb_count;
 444         int good_peb_count;
 445         int erroneous_peb_count;
 446         int max_erroneous;
 447         int min_io_size;
 448         int hdrs_min_io_size;
 449         int ro_mode;
 450         int leb_size;
 451         int leb_start;
 452         int ec_hdr_alsize;
 453         int vid_hdr_alsize;
 454         int vid_hdr_offset;
 455         int vid_hdr_aloffset;
 456         int vid_hdr_shift;
 457         unsigned int bad_allowed:1;
 458         unsigned int nor_flash:1;
 459         struct mtd_info *mtd;
 460
 461         void *peb_buf1;
 462         void *peb_buf2;
 463         struct mutex buf_mutex;
 464         struct mutex ckvol_mutex;
 465 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
 466         void *dbg_peb_buf;
 467         struct mutex dbg_buf_mutex;
 468 #endif
 469 };
 470
 471 extern struct kmem_cache *ubi_wl_entry_slab;
 472 extern const struct file_operations ubi_ctrl_cdev_operations;
 473 extern const struct file_operations ubi_cdev_operations;
 474 extern const struct file_operations ubi_vol_cdev_operations;
 475 extern struct class *ubi_class;
 476 extern struct mutex ubi_devices_mutex;
 477 extern struct blocking_notifier_head ubi_notifiers;
 478
 479 /* vtbl.c */
 480 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 481                            struct ubi_vtbl_record *vtbl_rec);
 482 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
 483                             struct list_head *rename_list);
 484 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
 485
 486 /* vmt.c */
 487 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
 488 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
 489 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
 490 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
 491 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 492 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 493
 494 /* upd.c */
 495 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
 496                      long long bytes);
 497 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
 498                          const void __user *buf, int count);
 499 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 500                          const struct ubi_leb_change_req *req);
 501 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
 502                              const void __user *buf, int count);
 503
 504 /* misc.c */
 505 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
 506                       int length);
 507 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 508 void ubi_calculate_reserved(struct ubi_device *ubi);
 509
 510 /* eba.c */
 511 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 512                       int lnum);
 513 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 514                      void *buf, int offset, int len, int check);
 515 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 516                       const void *buf, int offset, int len, int dtype);
 517 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 518                          int lnum, const void *buf, int len, int dtype,
 519                          int used_ebs);
 520 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 521                               int lnum, const void *buf, int len, int dtype);
 522 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 523                      struct ubi_vid_hdr *vid_hdr);
 524 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 525
 526 /* wl.c */
 527 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
 528 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
 529 int ubi_wl_flush(struct ubi_device *ubi);
 530 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
 531 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 532 void ubi_wl_close(struct ubi_device *ubi);
 533 int ubi_thread(void *u);
 534
 535 /* io.c */
 536 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
 537                 int len);
 538 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
 539                  int len);
 540 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
 541 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
 542 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
 543 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 544                        struct ubi_ec_hdr *ec_hdr, int verbose);
 545 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
 546                         struct ubi_ec_hdr *ec_hdr);
 547 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 548                         struct ubi_vid_hdr *vid_hdr, int verbose);
 549 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
 550                          struct ubi_vid_hdr *vid_hdr);
 551
 552 /* build.c */
 553 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
 554 int ubi_detach_mtd_dev(int ubi_num, int anyway);
 555 struct ubi_device *ubi_get_device(int ubi_num);
 556 void ubi_put_device(struct ubi_device *ubi);
 557 struct ubi_device *ubi_get_by_major(int major);
 558 int ubi_major2num(int major);
 559 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
 560                       int ntype);
 561 int ubi_notify_all(struct ubi_device *ubi, int ntype,
 562                    struct notifier_block *nb);
 563 int ubi_enumerate_volumes(struct notifier_block *nb);
 564
 565 /* kapi.c */
 566 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
 567 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
 568                             struct ubi_volume_info *vi);
 569
 570 /*
 571  * ubi_rb_for_each_entry - walk an RB-tree.
 572  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
 573  * @pos: a pointer to RB-tree entry type to use as a loop counter
 574  * @root: RB-tree's root
 575  * @member: the name of the 'struct rb_node' within the RB-tree entry
 576  */
 577 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
 578         for (rb = rb_first(root),                                            \
 579              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
 580              rb;                                                             \
 581              rb = rb_next(rb),                                               \
 582              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
 583
 584 /**
 585  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
 586  * @ubi: UBI device description object
 587  * @gfp_flags: GFP flags to allocate with
 588  *
 589  * This function returns a pointer to the newly allocated and zero-filled
 590  * volume identifier header object in case of success and %NULL in case of
 591  * failure.
 592  */
 593 static inline struct ubi_vid_hdr *
 594 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
 595 {
 596         void *vid_hdr;
 597
 598         vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
 599         if (!vid_hdr)
 600                 return NULL;
 601
 602         /*
 603          * VID headers may be stored at un-aligned flash offsets, so we shift
 604          * the pointer.
 605          */
 606         return vid_hdr + ubi->vid_hdr_shift;
 607 }
 608
 609 /**
 610  * ubi_free_vid_hdr - free a volume identifier header object.
 611  * @ubi: UBI device description object
 612  * @vid_hdr: the object to free
 613  */
 614 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
 615                                     struct ubi_vid_hdr *vid_hdr)
 616 {
 617         void *p = vid_hdr;
 618
 619         if (!p)
 620                 return;
 621
 622         kfree(p - ubi->vid_hdr_shift);
 623 }
 624
 625 /*
 626  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
 627  * the beginning of the logical eraseblock, not to the beginning of the
 628  * physical eraseblock.
 629  */
 630 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
 631                                    int pnum, int offset, int len)
 632 {
 633         ubi_assert(offset >= 0);
 634         return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
 635 }
 636
 637 /*
 638  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
 639  * the beginning of the logical eraseblock, not to the beginning of the
 640  * physical eraseblock.
 641  */
 642 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
 643                                     int pnum, int offset, int len)
 644 {
 645         ubi_assert(offset >= 0);
 646         return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
 647 }
 648
 649 /**
 650  * ubi_ro_mode - switch to read-only mode.
 651  * @ubi: UBI device description object
 652  */
 653 static inline void ubi_ro_mode(struct ubi_device *ubi)
 654 {
 655         if (!ubi->ro_mode) {
 656                 ubi->ro_mode = 1;
 657                 ubi_warn("switch to read-only mode");
 658         }
 659 }
 660
 661 /**
 662  * vol_id2idx - get table index by volume ID.
 663  * @ubi: UBI device description object
 664  * @vol_id: volume ID
 665  */
 666 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
 667 {
 668         if (vol_id >= UBI_INTERNAL_VOL_START)
 669                 return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
 670         else
 671                 return vol_id;
 672 }
 673
 674 /**
 675  * idx2vol_id - get volume ID by table index.
 676  * @ubi: UBI device description object
 677  * @idx: table index
 678  */
 679 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
 680 {
 681         if (idx >= ubi->vtbl_slots)
 682                 return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
 683         else
 684                 return idx;
 685 }
 686
 687 #endif /* !__UBI_UBI_H__ */