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  * MOVE_RETRY: retry scrubbing the PEB
 124  */
 125 enum {
 126         MOVE_CANCEL_RACE = 1,
 127         MOVE_SOURCE_RD_ERR,
 128         MOVE_TARGET_RD_ERR,
 129         MOVE_TARGET_WR_ERR,
 130         MOVE_CANCEL_BITFLIPS,
 131         MOVE_RETRY,
 132 };
 133
 134 /**
 135  * struct ubi_wl_entry - wear-leveling entry.
 136  * @u.rb: link in the corresponding (free/used) RB-tree
 137  * @u.list: link in the protection queue
 138  * @ec: erase counter
 139  * @pnum: physical eraseblock number
 140  *
 141  * This data structure is used in the WL sub-system. Each physical eraseblock
 142  * has a corresponding &struct wl_entry object which may be kept in different
 143  * RB-trees. See WL sub-system for details.
 144  */
 145 struct ubi_wl_entry {
 146         union {
 147                 struct rb_node rb;
 148                 struct list_head list;
 149         } u;
 150         int ec;
 151         int pnum;
 152 };
 153
 154 /**
 155  * struct ubi_ltree_entry - an entry in the lock tree.
 156  * @rb: links RB-tree nodes
 157  * @vol_id: volume ID of the locked logical eraseblock
 158  * @lnum: locked logical eraseblock number
 159  * @users: how many tasks are using this logical eraseblock or wait for it
 160  * @mutex: read/write mutex to implement read/write access serialization to
 161  *         the (@vol_id, @lnum) logical eraseblock
 162  *
 163  * This data structure is used in the EBA sub-system to implement per-LEB
 164  * locking. When a logical eraseblock is being locked - corresponding
 165  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
 166  * See EBA sub-system for details.
 167  */
 168 struct ubi_ltree_entry {
 169         struct rb_node rb;
 170         int vol_id;
 171         int lnum;
 172         int users;
 173         struct rw_semaphore mutex;
 174 };
 175
 176 /**
 177  * struct ubi_rename_entry - volume re-name description data structure.
 178  * @new_name_len: new volume name length
 179  * @new_name: new volume name
 180  * @remove: if not zero, this volume should be removed, not re-named
 181  * @desc: descriptor of the volume
 182  * @list: links re-name entries into a list
 183  *
 184  * This data structure is utilized in the multiple volume re-name code. Namely,
 185  * UBI first creates a list of &struct ubi_rename_entry objects from the
 186  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
 187  * the job.
 188  */
 189 struct ubi_rename_entry {
 190         int new_name_len;
 191         char new_name[UBI_VOL_NAME_MAX + 1];
 192         int remove;
 193         struct ubi_volume_desc *desc;
 194         struct list_head list;
 195 };
 196
 197 struct ubi_volume_desc;
 198
 199 /**
 200  * struct ubi_volume - UBI volume description data structure.
 201  * @dev: device object to make use of the the Linux device model
 202  * @cdev: character device object to create character device
 203  * @ubi: reference to the UBI device description object
 204  * @vol_id: volume ID
 205  * @ref_count: volume reference count
 206  * @readers: number of users holding this volume in read-only mode
 207  * @writers: number of users holding this volume in read-write mode
 208  * @exclusive: whether somebody holds this volume in exclusive mode
 209  *
 210  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
 211  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
 212  * @usable_leb_size: logical eraseblock size without padding
 213  * @used_ebs: how many logical eraseblocks in this volume contain data
 214  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
 215  * @used_bytes: how many bytes of data this volume contains
 216  * @alignment: volume alignment
 217  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
 218  *            satisfy the requested alignment
 219  * @name_len: volume name length
 220  * @name: volume name
 221  *
 222  * @upd_ebs: how many eraseblocks are expected to be updated
 223  * @ch_lnum: LEB number which is being changing by the atomic LEB change
 224  *           operation
 225  * @ch_dtype: data persistency type which is being changing by the atomic LEB
 226  *            change operation
 227  * @upd_bytes: how many bytes are expected to be received for volume update or
 228  *             atomic LEB change
 229  * @upd_received: how many bytes were already received for volume update or
 230  *                atomic LEB change
 231  * @upd_buf: update buffer which is used to collect update data or data for
 232  *           atomic LEB change
 233  *
 234  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
 235  * @checked: %1 if this static volume was checked
 236  * @corrupted: %1 if the volume is corrupted (static volumes only)
 237  * @upd_marker: %1 if the update marker is set for this volume
 238  * @updating: %1 if the volume is being updated
 239  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
 240  * @direct_writes: %1 if direct writes are enabled for this volume
 241  *
 242  * The @corrupted field indicates that the volume's contents is corrupted.
 243  * Since UBI protects only static volumes, this field is not relevant to
 244  * dynamic volumes - it is user's responsibility to assure their data
 245  * integrity.
 246  *
 247  * The @upd_marker flag indicates that this volume is either being updated at
 248  * the moment or is damaged because of an unclean reboot.
 249  */
 250 struct ubi_volume {
 251         struct device dev;
 252         struct cdev cdev;
 253         struct ubi_device *ubi;
 254         int vol_id;
 255         int ref_count;
 256         int readers;
 257         int writers;
 258         int exclusive;
 259
 260         int reserved_pebs;
 261         int vol_type;
 262         int usable_leb_size;
 263         int used_ebs;
 264         int last_eb_bytes;
 265         long long used_bytes;
 266         int alignment;
 267         int data_pad;
 268         int name_len;
 269         char name[UBI_VOL_NAME_MAX + 1];
 270
 271         int upd_ebs;
 272         int ch_lnum;
 273         int ch_dtype;
 274         long long upd_bytes;
 275         long long upd_received;
 276         void *upd_buf;
 277
 278         int *eba_tbl;
 279         unsigned int checked:1;
 280         unsigned int corrupted:1;
 281         unsigned int upd_marker:1;
 282         unsigned int updating:1;
 283         unsigned int changing_leb:1;
 284         unsigned int direct_writes:1;
 285 };
 286
 287 /**
 288  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
 289  * @vol: reference to the corresponding volume description object
 290  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
 291  */
 292 struct ubi_volume_desc {
 293         struct ubi_volume *vol;
 294         int mode;
 295 };
 296
 297 struct ubi_wl_entry;
 298
 299 /**
 300  * struct ubi_device - UBI device description structure
 301  * @dev: UBI device object to use the the Linux device model
 302  * @cdev: character device object to create character device
 303  * @ubi_num: UBI device number
 304  * @ubi_name: UBI device name
 305  * @vol_count: number of volumes in this UBI device
 306  * @volumes: volumes of this UBI device
 307  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
 308  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
 309  *                @vol->readers, @vol->writers, @vol->exclusive,
 310  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
 311  * @ref_count: count of references on the UBI device
 312  * @image_seq: image sequence number recorded on EC headers
 313  *
 314  * @rsvd_pebs: count of reserved physical eraseblocks
 315  * @avail_pebs: count of available physical eraseblocks
 316  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
 317  *                 handling
 318  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
 319  *
 320  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
 321  *                     of UBI initialization
 322  * @vtbl_slots: how many slots are available in the volume table
 323  * @vtbl_size: size of the volume table in bytes
 324  * @vtbl: in-RAM volume table copy
 325  * @device_mutex: protects on-flash volume table and serializes volume
 326  *                creation, deletion, update, re-size, re-name and set
 327  *                property
 328  *
 329  * @max_ec: current highest erase counter value
 330  * @mean_ec: current mean erase counter value
 331  *
 332  * @global_sqnum: global sequence number
 333  * @ltree_lock: protects the lock tree and @global_sqnum
 334  * @ltree: the lock tree
 335  * @alc_mutex: serializes "atomic LEB change" operations
 336  *
 337  * @used: RB-tree of used physical eraseblocks
 338  * @erroneous: RB-tree of erroneous used physical eraseblocks
 339  * @free: RB-tree of free physical eraseblocks
 340  * @scrub: RB-tree of physical eraseblocks which need scrubbing
 341  * @pq: protection queue (contain physical eraseblocks which are temporarily
 342  *      protected from the wear-leveling worker)
 343  * @pq_head: protection queue head
 344  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
 345  *           @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
 346  *           @erroneous, and @erroneous_peb_count fields
 347  * @move_mutex: serializes eraseblock moves
 348  * @work_sem: synchronizes the WL worker with use tasks
 349  * @wl_scheduled: non-zero if the wear-leveling was scheduled
 350  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
 351  *             physical eraseblock
 352  * @move_from: physical eraseblock from where the data is being moved
 353  * @move_to: physical eraseblock where the data is being moved to
 354  * @move_to_put: if the "to" PEB was put
 355  * @works: list of pending works
 356  * @works_count: count of pending works
 357  * @bgt_thread: background thread description object
 358  * @thread_enabled: if the background thread is enabled
 359  * @bgt_name: background thread name
 360  *
 361  * @flash_size: underlying MTD device size (in bytes)
 362  * @peb_count: count of physical eraseblocks on the MTD device
 363  * @peb_size: physical eraseblock size
 364  * @bad_peb_count: count of bad physical eraseblocks
 365  * @good_peb_count: count of good physical eraseblocks
 366  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
 367  *                  used by UBI)
 368  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
 369  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
 370  * @min_io_size: minimal input/output unit size of the underlying MTD device
 371  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
 372  * @ro_mode: if the UBI device is in read-only mode
 373  * @leb_size: logical eraseblock size
 374  * @leb_start: starting offset of logical eraseblocks within physical
 375  *             eraseblocks
 376  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
 377  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
 378  * @vid_hdr_offset: starting offset of the volume identifier header (might be
 379  *                  unaligned)
 380  * @vid_hdr_aloffset: starting offset of the VID header aligned to
 381  * @hdrs_min_io_size
 382  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
 383  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
 384  *               not
 385  * @nor_flash: non-zero if working on top of NOR flash
 386  * @max_write_size: maximum amount of bytes the underlying flash can write at a
 387  *                  time (MTD write buffer size)
 388  * @mtd: MTD device descriptor
 389  *
 390  * @peb_buf1: a buffer of PEB size used for different purposes
 391  * @peb_buf2: another buffer of PEB size used for different purposes
 392  * @buf_mutex: protects @peb_buf1 and @peb_buf2
 393  * @ckvol_mutex: serializes static volume checking when opening
 394  *
 395  * @dbg: debugging information for this UBI device
 396  */
 397 struct ubi_device {
 398         struct cdev cdev;
 399         struct device dev;
 400         int ubi_num;
 401         char ubi_name[sizeof(UBI_NAME_STR)+5];
 402         int vol_count;
 403         struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
 404         spinlock_t volumes_lock;
 405         int ref_count;
 406         int image_seq;
 407
 408         int rsvd_pebs;
 409         int avail_pebs;
 410         int beb_rsvd_pebs;
 411         int beb_rsvd_level;
 412
 413         int autoresize_vol_id;
 414         int vtbl_slots;
 415         int vtbl_size;
 416         struct ubi_vtbl_record *vtbl;
 417         struct mutex device_mutex;
 418
 419         int max_ec;
 420         /* Note, mean_ec is not updated run-time - should be fixed */
 421         int mean_ec;
 422
 423         /* EBA sub-system's stuff */
 424         unsigned long long global_sqnum;
 425         spinlock_t ltree_lock;
 426         struct rb_root ltree;
 427         struct mutex alc_mutex;
 428
 429         /* Wear-leveling sub-system's stuff */
 430         struct rb_root used;
 431         struct rb_root erroneous;
 432         struct rb_root free;
 433         struct rb_root scrub;
 434         struct list_head pq[UBI_PROT_QUEUE_LEN];
 435         int pq_head;
 436         spinlock_t wl_lock;
 437         struct mutex move_mutex;
 438         struct rw_semaphore work_sem;
 439         int wl_scheduled;
 440         struct ubi_wl_entry **lookuptbl;
 441         struct ubi_wl_entry *move_from;
 442         struct ubi_wl_entry *move_to;
 443         int move_to_put;
 444         struct list_head works;
 445         int works_count;
 446         struct task_struct *bgt_thread;
 447         int thread_enabled;
 448         char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
 449
 450         /* I/O sub-system's stuff */
 451         long long flash_size;
 452         int peb_count;
 453         int peb_size;
 454         int bad_peb_count;
 455         int good_peb_count;
 456         int corr_peb_count;
 457         int erroneous_peb_count;
 458         int max_erroneous;
 459         int min_io_size;
 460         int hdrs_min_io_size;
 461         int ro_mode;
 462         int leb_size;
 463         int leb_start;
 464         int ec_hdr_alsize;
 465         int vid_hdr_alsize;
 466         int vid_hdr_offset;
 467         int vid_hdr_aloffset;
 468         int vid_hdr_shift;
 469         unsigned int bad_allowed:1;
 470         unsigned int nor_flash:1;
 471         int max_write_size;
 472         struct mtd_info *mtd;
 473
 474         void *peb_buf1;
 475         void *peb_buf2;
 476         struct mutex buf_mutex;
 477         struct mutex ckvol_mutex;
 478
 479         struct ubi_debug_info *dbg;
 480 };
 481
 482 #include "debug.h"
 483
 484 extern struct kmem_cache *ubi_wl_entry_slab;
 485 extern const struct file_operations ubi_ctrl_cdev_operations;
 486 extern const struct file_operations ubi_cdev_operations;
 487 extern const struct file_operations ubi_vol_cdev_operations;
 488 extern struct class *ubi_class;
 489 extern struct mutex ubi_devices_mutex;
 490 extern struct blocking_notifier_head ubi_notifiers;
 491
 492 /* vtbl.c */
 493 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 494                            struct ubi_vtbl_record *vtbl_rec);
 495 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
 496                             struct list_head *rename_list);
 497 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
 498
 499 /* vmt.c */
 500 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
 501 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
 502 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
 503 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
 504 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 505 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 506
 507 /* upd.c */
 508 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
 509                      long long bytes);
 510 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
 511                          const void __user *buf, int count);
 512 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 513                          const struct ubi_leb_change_req *req);
 514 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
 515                              const void __user *buf, int count);
 516
 517 /* misc.c */
 518 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
 519                       int length);
 520 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 521 void ubi_calculate_reserved(struct ubi_device *ubi);
 522 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
 523
 524 /* eba.c */
 525 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 526                       int lnum);
 527 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 528                      void *buf, int offset, int len, int check);
 529 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 530                       const void *buf, int offset, int len, int dtype);
 531 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 532                          int lnum, const void *buf, int len, int dtype,
 533                          int used_ebs);
 534 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 535                               int lnum, const void *buf, int len, int dtype);
 536 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 537                      struct ubi_vid_hdr *vid_hdr);
 538 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 539
 540 /* wl.c */
 541 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
 542 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
 543 int ubi_wl_flush(struct ubi_device *ubi);
 544 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
 545 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 546 void ubi_wl_close(struct ubi_device *ubi);
 547 int ubi_thread(void *u);
 548
 549 /* io.c */
 550 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
 551                 int len);
 552 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
 553                  int len);
 554 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
 555 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
 556 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
 557 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 558                        struct ubi_ec_hdr *ec_hdr, int verbose);
 559 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
 560                         struct ubi_ec_hdr *ec_hdr);
 561 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 562                         struct ubi_vid_hdr *vid_hdr, int verbose);
 563 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
 564                          struct ubi_vid_hdr *vid_hdr);
 565
 566 /* build.c */
 567 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
 568 int ubi_detach_mtd_dev(int ubi_num, int anyway);
 569 struct ubi_device *ubi_get_device(int ubi_num);
 570 void ubi_put_device(struct ubi_device *ubi);
 571 struct ubi_device *ubi_get_by_major(int major);
 572 int ubi_major2num(int major);
 573 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
 574                       int ntype);
 575 int ubi_notify_all(struct ubi_device *ubi, int ntype,
 576                    struct notifier_block *nb);
 577 int ubi_enumerate_volumes(struct notifier_block *nb);
 578
 579 /* kapi.c */
 580 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
 581 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
 582                             struct ubi_volume_info *vi);
 583
 584 /*
 585  * ubi_rb_for_each_entry - walk an RB-tree.
 586  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
 587  * @pos: a pointer to RB-tree entry type to use as a loop counter
 588  * @root: RB-tree's root
 589  * @member: the name of the 'struct rb_node' within the RB-tree entry
 590  */
 591 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
 592         for (rb = rb_first(root),                                            \
 593              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
 594              rb;                                                             \
 595              rb = rb_next(rb),                                               \
 596              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
 597
 598 /**
 599  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
 600  * @ubi: UBI device description object
 601  * @gfp_flags: GFP flags to allocate with
 602  *
 603  * This function returns a pointer to the newly allocated and zero-filled
 604  * volume identifier header object in case of success and %NULL in case of
 605  * failure.
 606  */
 607 static inline struct ubi_vid_hdr *
 608 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
 609 {
 610         void *vid_hdr;
 611
 612         vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
 613         if (!vid_hdr)
 614                 return NULL;
 615
 616         /*
 617          * VID headers may be stored at un-aligned flash offsets, so we shift
 618          * the pointer.
 619          */
 620         return vid_hdr + ubi->vid_hdr_shift;
 621 }
 622
 623 /**
 624  * ubi_free_vid_hdr - free a volume identifier header object.
 625  * @ubi: UBI device description object
 626  * @vid_hdr: the object to free
 627  */
 628 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
 629                                     struct ubi_vid_hdr *vid_hdr)
 630 {
 631         void *p = vid_hdr;
 632
 633         if (!p)
 634                 return;
 635
 636         kfree(p - ubi->vid_hdr_shift);
 637 }
 638
 639 /*
 640  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
 641  * the beginning of the logical eraseblock, not to the beginning of the
 642  * physical eraseblock.
 643  */
 644 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
 645                                    int pnum, int offset, int len)
 646 {
 647         ubi_assert(offset >= 0);
 648         return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
 649 }
 650
 651 /*
 652  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
 653  * the beginning of the logical eraseblock, not to the beginning of the
 654  * physical eraseblock.
 655  */
 656 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
 657                                     int pnum, int offset, int len)
 658 {
 659         ubi_assert(offset >= 0);
 660         return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
 661 }
 662
 663 /**
 664  * ubi_ro_mode - switch to read-only mode.
 665  * @ubi: UBI device description object
 666  */
 667 static inline void ubi_ro_mode(struct ubi_device *ubi)
 668 {
 669         if (!ubi->ro_mode) {
 670                 ubi->ro_mode = 1;
 671                 ubi_warn("switch to read-only mode");
 672                 ubi_dbg_dump_stack();
 673         }
 674 }
 675
 676 /**
 677  * vol_id2idx - get table index by volume ID.
 678  * @ubi: UBI device description object
 679  * @vol_id: volume ID
 680  */
 681 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
 682 {
 683         if (vol_id >= UBI_INTERNAL_VOL_START)
 684                 return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
 685         else
 686                 return vol_id;
 687 }
 688
 689 /**
 690  * idx2vol_id - get volume ID by table index.
 691  * @ubi: UBI device description object
 692  * @idx: table index
 693  */
 694 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
 695 {
 696         if (idx >= ubi->vtbl_slots)
 697                 return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
 698         else
 699                 return idx;
 700 }
 701
 702 #endif /* !__UBI_UBI_H__ */