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 #include <asm/pgtable.h>
  44
  45 #include "ubi-media.h"
  46 #include "scan.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_FF: the read region of flash contains only 0xFFs
  89  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
  90  *                     integrity error reported by the MTD driver
  91  *                     (uncorrectable ECC error in case of NAND)
  92  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
  93  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
  94  *                         data integrity error reported by the MTD driver
  95  *                         (uncorrectable ECC error in case of NAND)
  96  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
  97  *
  98  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
  99  * be or'ed with other error code. But this is a big change because there are
 100  * may callers, so it does not worth the risk of introducing a bug
 101  */
 102 enum {
 103         UBI_IO_FF = 1,
 104         UBI_IO_FF_BITFLIPS,
 105         UBI_IO_BAD_HDR,
 106         UBI_IO_BAD_HDR_EBADMSG,
 107         UBI_IO_BITFLIPS,
 108 };
 109
 110 /*
 111  * Return codes of the 'ubi_eba_copy_leb()' function.
 112  *
 113  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
 114  *                   PEB was put meanwhile, or there is I/O on the source PEB
 115  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
 116  *                     PEB
 117  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
 118  *                     PEB
 119  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
 120  *                     PEB
 121  * MOVE_CANCEL_BITFLIPS: canceled because a bit-flip was detected in the
 122  *                       target PEB
 123  */
 124 enum {
 125         MOVE_CANCEL_RACE = 1,
 126         MOVE_SOURCE_RD_ERR,
 127         MOVE_TARGET_RD_ERR,
 128         MOVE_TARGET_WR_ERR,
 129         MOVE_CANCEL_BITFLIPS,
 130 };
 131
 132 /**
 133  * struct ubi_wl_entry - wear-leveling entry.
 134  * @u.rb: link in the corresponding (free/used) RB-tree
 135  * @u.list: link in the protection queue
 136  * @ec: erase counter
 137  * @pnum: physical eraseblock number
 138  *
 139  * This data structure is used in the WL sub-system. Each physical eraseblock
 140  * has a corresponding &struct wl_entry object which may be kept in different
 141  * RB-trees. See WL sub-system for details.
 142  */
 143 struct ubi_wl_entry {
 144         union {
 145                 struct rb_node rb;
 146                 struct list_head list;
 147         } u;
 148         int ec;
 149         int pnum;
 150 };
 151
 152 /**
 153  * struct ubi_ltree_entry - an entry in the lock tree.
 154  * @rb: links RB-tree nodes
 155  * @vol_id: volume ID of the locked logical eraseblock
 156  * @lnum: locked logical eraseblock number
 157  * @users: how many tasks are using this logical eraseblock or wait for it
 158  * @mutex: read/write mutex to implement read/write access serialization to
 159  *         the (@vol_id, @lnum) logical eraseblock
 160  *
 161  * This data structure is used in the EBA sub-system to implement per-LEB
 162  * locking. When a logical eraseblock is being locked - corresponding
 163  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
 164  * See EBA sub-system for details.
 165  */
 166 struct ubi_ltree_entry {
 167         struct rb_node rb;
 168         int vol_id;
 169         int lnum;
 170         int users;
 171         struct rw_semaphore mutex;
 172 };
 173
 174 /**
 175  * struct ubi_rename_entry - volume re-name description data structure.
 176  * @new_name_len: new volume name length
 177  * @new_name: new volume name
 178  * @remove: if not zero, this volume should be removed, not re-named
 179  * @desc: descriptor of the volume
 180  * @list: links re-name entries into a list
 181  *
 182  * This data structure is utilized in the multiple volume re-name code. Namely,
 183  * UBI first creates a list of &struct ubi_rename_entry objects from the
 184  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
 185  * the job.
 186  */
 187 struct ubi_rename_entry {
 188         int new_name_len;
 189         char new_name[UBI_VOL_NAME_MAX + 1];
 190         int remove;
 191         struct ubi_volume_desc *desc;
 192         struct list_head list;
 193 };
 194
 195 struct ubi_volume_desc;
 196
 197 /**
 198  * struct ubi_volume - UBI volume description data structure.
 199  * @dev: device object to make use of the the Linux device model
 200  * @cdev: character device object to create character device
 201  * @ubi: reference to the UBI device description object
 202  * @vol_id: volume ID
 203  * @ref_count: volume reference count
 204  * @readers: number of users holding this volume in read-only mode
 205  * @writers: number of users holding this volume in read-write mode
 206  * @exclusive: whether somebody holds this volume in exclusive mode
 207  *
 208  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
 209  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
 210  * @usable_leb_size: logical eraseblock size without padding
 211  * @used_ebs: how many logical eraseblocks in this volume contain data
 212  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
 213  * @used_bytes: how many bytes of data this volume contains
 214  * @alignment: volume alignment
 215  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
 216  *            satisfy the requested alignment
 217  * @name_len: volume name length
 218  * @name: volume name
 219  *
 220  * @upd_ebs: how many eraseblocks are expected to be updated
 221  * @ch_lnum: LEB number which is being changing by the atomic LEB change
 222  *           operation
 223  * @ch_dtype: data persistency type which is being changing by the atomic LEB
 224  *            change operation
 225  * @upd_bytes: how many bytes are expected to be received for volume update or
 226  *             atomic LEB change
 227  * @upd_received: how many bytes were already received for volume update or
 228  *                atomic LEB change
 229  * @upd_buf: update buffer which is used to collect update data or data for
 230  *           atomic LEB change
 231  *
 232  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
 233  * @checked: %1 if this static volume was checked
 234  * @corrupted: %1 if the volume is corrupted (static volumes only)
 235  * @upd_marker: %1 if the update marker is set for this volume
 236  * @updating: %1 if the volume is being updated
 237  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
 238  * @direct_writes: %1 if direct writes are enabled for this volume
 239  *
 240  * The @corrupted field indicates that the volume's contents is corrupted.
 241  * Since UBI protects only static volumes, this field is not relevant to
 242  * dynamic volumes - it is user's responsibility to assure their data
 243  * integrity.
 244  *
 245  * The @upd_marker flag indicates that this volume is either being updated at
 246  * the moment or is damaged because of an unclean reboot.
 247  */
 248 struct ubi_volume {
 249         struct device dev;
 250         struct cdev cdev;
 251         struct ubi_device *ubi;
 252         int vol_id;
 253         int ref_count;
 254         int readers;
 255         int writers;
 256         int exclusive;
 257
 258         int reserved_pebs;
 259         int vol_type;
 260         int usable_leb_size;
 261         int used_ebs;
 262         int last_eb_bytes;
 263         long long used_bytes;
 264         int alignment;
 265         int data_pad;
 266         int name_len;
 267         char name[UBI_VOL_NAME_MAX + 1];
 268
 269         int upd_ebs;
 270         int ch_lnum;
 271         int ch_dtype;
 272         long long upd_bytes;
 273         long long upd_received;
 274         void *upd_buf;
 275
 276         int *eba_tbl;
 277         unsigned int checked:1;
 278         unsigned int corrupted:1;
 279         unsigned int upd_marker:1;
 280         unsigned int updating:1;
 281         unsigned int changing_leb:1;
 282         unsigned int direct_writes:1;
 283 };
 284
 285 /**
 286  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
 287  * @vol: reference to the corresponding volume description object
 288  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
 289  */
 290 struct ubi_volume_desc {
 291         struct ubi_volume *vol;
 292         int mode;
 293 };
 294
 295 struct ubi_wl_entry;
 296
 297 /**
 298  * struct ubi_device - UBI device description structure
 299  * @dev: UBI device object to use the the Linux device model
 300  * @cdev: character device object to create character device
 301  * @ubi_num: UBI device number
 302  * @ubi_name: UBI device name
 303  * @vol_count: number of volumes in this UBI device
 304  * @volumes: volumes of this UBI device
 305  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
 306  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
 307  *                @vol->readers, @vol->writers, @vol->exclusive,
 308  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
 309  * @ref_count: count of references on the UBI device
 310  * @image_seq: image sequence number recorded on EC headers
 311  *
 312  * @rsvd_pebs: count of reserved physical eraseblocks
 313  * @avail_pebs: count of available physical eraseblocks
 314  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
 315  *                 handling
 316  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
 317  *
 318  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
 319  *                     of UBI initialization
 320  * @vtbl_slots: how many slots are available in the volume table
 321  * @vtbl_size: size of the volume table in bytes
 322  * @vtbl: in-RAM volume table copy
 323  * @device_mutex: protects on-flash volume table and serializes volume
 324  *                creation, deletion, update, re-size, re-name and set
 325  *                property
 326  *
 327  * @max_ec: current highest erase counter value
 328  * @mean_ec: current mean erase counter value
 329  *
 330  * @global_sqnum: global sequence number
 331  * @ltree_lock: protects the lock tree and @global_sqnum
 332  * @ltree: the lock tree
 333  * @alc_mutex: serializes "atomic LEB change" operations
 334  *
 335  * @used: RB-tree of used physical eraseblocks
 336  * @erroneous: RB-tree of erroneous used physical eraseblocks
 337  * @free: RB-tree of free physical eraseblocks
 338  * @scrub: RB-tree of physical eraseblocks which need scrubbing
 339  * @pq: protection queue (contain physical eraseblocks which are temporarily
 340  *      protected from the wear-leveling worker)
 341  * @pq_head: protection queue head
 342  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
 343  *           @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
 344  *           @erroneous, and @erroneous_peb_count fields
 345  * @move_mutex: serializes eraseblock moves
 346  * @work_sem: synchronizes the WL worker with use tasks
 347  * @wl_scheduled: non-zero if the wear-leveling was scheduled
 348  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
 349  *             physical eraseblock
 350  * @move_from: physical eraseblock from where the data is being moved
 351  * @move_to: physical eraseblock where the data is being moved to
 352  * @move_to_put: if the "to" PEB was put
 353  * @works: list of pending works
 354  * @works_count: count of pending works
 355  * @bgt_thread: background thread description object
 356  * @thread_enabled: if the background thread is enabled
 357  * @bgt_name: background thread name
 358  *
 359  * @flash_size: underlying MTD device size (in bytes)
 360  * @peb_count: count of physical eraseblocks on the MTD device
 361  * @peb_size: physical eraseblock size
 362  * @bad_peb_count: count of bad physical eraseblocks
 363  * @good_peb_count: count of good physical eraseblocks
 364  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
 365  *                  used by UBI)
 366  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
 367  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
 368  * @min_io_size: minimal input/output unit size of the underlying MTD device
 369  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
 370  * @ro_mode: if the UBI device is in read-only mode
 371  * @leb_size: logical eraseblock size
 372  * @leb_start: starting offset of logical eraseblocks within physical
 373  *             eraseblocks
 374  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
 375  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
 376  * @vid_hdr_offset: starting offset of the volume identifier header (might be
 377  *                  unaligned)
 378  * @vid_hdr_aloffset: starting offset of the VID header aligned to
 379  * @hdrs_min_io_size
 380  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
 381  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
 382  *               not
 383  * @nor_flash: non-zero if working on top of NOR flash
 384  * @max_write_size: maximum amount of bytes the underlying flash can write at a
 385  *                  time (MTD write buffer size)
 386  * @mtd: MTD device descriptor
 387  *
 388  * @peb_buf1: a buffer of PEB size used for different purposes
 389  * @peb_buf2: another buffer of PEB size used for different purposes
 390  * @buf_mutex: protects @peb_buf1 and @peb_buf2
 391  * @ckvol_mutex: serializes static volume checking when opening
 392  *
 393  * @dbg: debugging information for this UBI device
 394  */
 395 struct ubi_device {
 396         struct cdev cdev;
 397         struct device dev;
 398         int ubi_num;
 399         char ubi_name[sizeof(UBI_NAME_STR)+5];
 400         int vol_count;
 401         struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
 402         spinlock_t volumes_lock;
 403         int ref_count;
 404         int image_seq;
 405
 406         int rsvd_pebs;
 407         int avail_pebs;
 408         int beb_rsvd_pebs;
 409         int beb_rsvd_level;
 410
 411         int autoresize_vol_id;
 412         int vtbl_slots;
 413         int vtbl_size;
 414         struct ubi_vtbl_record *vtbl;
 415         struct mutex device_mutex;
 416
 417         int max_ec;
 418         /* Note, mean_ec is not updated run-time - should be fixed */
 419         int mean_ec;
 420
 421         /* EBA sub-system's stuff */
 422         unsigned long long global_sqnum;
 423         spinlock_t ltree_lock;
 424         struct rb_root ltree;
 425         struct mutex alc_mutex;
 426
 427         /* Wear-leveling sub-system's stuff */
 428         struct rb_root used;
 429         struct rb_root erroneous;
 430         struct rb_root free;
 431         struct rb_root scrub;
 432         struct list_head pq[UBI_PROT_QUEUE_LEN];
 433         int pq_head;
 434         spinlock_t wl_lock;
 435         struct mutex move_mutex;
 436         struct rw_semaphore work_sem;
 437         int wl_scheduled;
 438         struct ubi_wl_entry **lookuptbl;
 439         struct ubi_wl_entry *move_from;
 440         struct ubi_wl_entry *move_to;
 441         int move_to_put;
 442         struct list_head works;
 443         int works_count;
 444         struct task_struct *bgt_thread;
 445         int thread_enabled;
 446         char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
 447
 448         /* I/O sub-system's stuff */
 449         long long flash_size;
 450         int peb_count;
 451         int peb_size;
 452         int bad_peb_count;
 453         int good_peb_count;
 454         int corr_peb_count;
 455         int erroneous_peb_count;
 456         int max_erroneous;
 457         int min_io_size;
 458         int hdrs_min_io_size;
 459         int ro_mode;
 460         int leb_size;
 461         int leb_start;
 462         int ec_hdr_alsize;
 463         int vid_hdr_alsize;
 464         int vid_hdr_offset;
 465         int vid_hdr_aloffset;
 466         int vid_hdr_shift;
 467         unsigned int bad_allowed:1;
 468         unsigned int nor_flash:1;
 469         int max_write_size;
 470         struct mtd_info *mtd;
 471
 472         void *peb_buf1;
 473         void *peb_buf2;
 474         struct mutex buf_mutex;
 475         struct mutex ckvol_mutex;
 476
 477         struct ubi_debug_info *dbg;
 478 };
 479
 480 #include "debug.h"
 481
 482 extern struct kmem_cache *ubi_wl_entry_slab;
 483 extern const struct file_operations ubi_ctrl_cdev_operations;
 484 extern const struct file_operations ubi_cdev_operations;
 485 extern const struct file_operations ubi_vol_cdev_operations;
 486 extern struct class *ubi_class;
 487 extern struct mutex ubi_devices_mutex;
 488 extern struct blocking_notifier_head ubi_notifiers;
 489
 490 /* vtbl.c */
 491 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 492                            struct ubi_vtbl_record *vtbl_rec);
 493 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
 494                             struct list_head *rename_list);
 495 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
 496
 497 /* vmt.c */
 498 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
 499 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
 500 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
 501 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
 502 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 503 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 504
 505 /* upd.c */
 506 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
 507                      long long bytes);
 508 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
 509                          const void __user *buf, int count);
 510 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 511                          const struct ubi_leb_change_req *req);
 512 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
 513                              const void __user *buf, int count);
 514
 515 /* misc.c */
 516 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
 517                       int length);
 518 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 519 void ubi_calculate_reserved(struct ubi_device *ubi);
 520 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
 521
 522 /* eba.c */
 523 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 524                       int lnum);
 525 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 526                      void *buf, int offset, int len, int check);
 527 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 528                       const void *buf, int offset, int len, int dtype);
 529 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 530                          int lnum, const void *buf, int len, int dtype,
 531                          int used_ebs);
 532 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 533                               int lnum, const void *buf, int len, int dtype);
 534 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 535                      struct ubi_vid_hdr *vid_hdr);
 536 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 537
 538 /* wl.c */
 539 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
 540 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
 541 int ubi_wl_flush(struct ubi_device *ubi);
 542 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
 543 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 544 void ubi_wl_close(struct ubi_device *ubi);
 545 int ubi_thread(void *u);
 546
 547 /* io.c */
 548 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
 549                 int len);
 550 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
 551                  int len);
 552 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
 553 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
 554 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
 555 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 556                        struct ubi_ec_hdr *ec_hdr, int verbose);
 557 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
 558                         struct ubi_ec_hdr *ec_hdr);
 559 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 560                         struct ubi_vid_hdr *vid_hdr, int verbose);
 561 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
 562                          struct ubi_vid_hdr *vid_hdr);
 563
 564 /* build.c */
 565 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
 566 int ubi_detach_mtd_dev(int ubi_num, int anyway);
 567 struct ubi_device *ubi_get_device(int ubi_num);
 568 void ubi_put_device(struct ubi_device *ubi);
 569 struct ubi_device *ubi_get_by_major(int major);
 570 int ubi_major2num(int major);
 571 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
 572                       int ntype);
 573 int ubi_notify_all(struct ubi_device *ubi, int ntype,
 574                    struct notifier_block *nb);
 575 int ubi_enumerate_volumes(struct notifier_block *nb);
 576
 577 /* kapi.c */
 578 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
 579 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
 580                             struct ubi_volume_info *vi);
 581
 582 /*
 583  * ubi_rb_for_each_entry - walk an RB-tree.
 584  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
 585  * @pos: a pointer to RB-tree entry type to use as a loop counter
 586  * @root: RB-tree's root
 587  * @member: the name of the 'struct rb_node' within the RB-tree entry
 588  */
 589 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
 590         for (rb = rb_first(root),                                            \
 591              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
 592              rb;                                                             \
 593              rb = rb_next(rb),                                               \
 594              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
 595
 596 /**
 597  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
 598  * @ubi: UBI device description object
 599  * @gfp_flags: GFP flags to allocate with
 600  *
 601  * This function returns a pointer to the newly allocated and zero-filled
 602  * volume identifier header object in case of success and %NULL in case of
 603  * failure.
 604  */
 605 static inline struct ubi_vid_hdr *
 606 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
 607 {
 608         void *vid_hdr;
 609
 610         vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
 611         if (!vid_hdr)
 612                 return NULL;
 613
 614         /*
 615          * VID headers may be stored at un-aligned flash offsets, so we shift
 616          * the pointer.
 617          */
 618         return vid_hdr + ubi->vid_hdr_shift;
 619 }
 620
 621 /**
 622  * ubi_free_vid_hdr - free a volume identifier header object.
 623  * @ubi: UBI device description object
 624  * @vid_hdr: the object to free
 625  */
 626 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
 627                                     struct ubi_vid_hdr *vid_hdr)
 628 {
 629         void *p = vid_hdr;
 630
 631         if (!p)
 632                 return;
 633
 634         kfree(p - ubi->vid_hdr_shift);
 635 }
 636
 637 /*
 638  * This function is equivalent to 'ubi_io_read()', 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_read_data(const struct ubi_device *ubi, void *buf,
 643                                    int pnum, int offset, int len)
 644 {
 645         ubi_assert(offset >= 0);
 646         return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
 647 }
 648
 649 /*
 650  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
 651  * the beginning of the logical eraseblock, not to the beginning of the
 652  * physical eraseblock.
 653  */
 654 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
 655                                     int pnum, int offset, int len)
 656 {
 657         ubi_assert(offset >= 0);
 658         return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
 659 }
 660
 661 /**
 662  * ubi_ro_mode - switch to read-only mode.
 663  * @ubi: UBI device description object
 664  */
 665 static inline void ubi_ro_mode(struct ubi_device *ubi)
 666 {
 667         if (!ubi->ro_mode) {
 668                 ubi->ro_mode = 1;
 669                 ubi_warn("switch to read-only mode");
 670                 ubi_dbg_dump_stack();
 671         }
 672 }
 673
 674 /**
 675  * vol_id2idx - get table index by volume ID.
 676  * @ubi: UBI device description object
 677  * @vol_id: volume ID
 678  */
 679 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
 680 {
 681         if (vol_id >= UBI_INTERNAL_VOL_START)
 682                 return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
 683         else
 684                 return vol_id;
 685 }
 686
 687 /**
 688  * idx2vol_id - get volume ID by table index.
 689  * @ubi: UBI device description object
 690  * @idx: table index
 691  */
 692 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
 693 {
 694         if (idx >= ubi->vtbl_slots)
 695                 return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
 696         else
 697                 return idx;
 698 }
 699
 700 #endif /* !__UBI_UBI_H__ */