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