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 #include "debug.h"
  48
  49 /* Maximum number of supported UBI devices */
  50 #define UBI_MAX_DEVICES 32
  51
  52 /* UBI name used for character devices, sysfs, etc */
  53 #define UBI_NAME_STR "ubi"
  54
  55 /* Normal UBI messages */
  56 #define ubi_msg(fmt, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__)
  57 /* UBI warning messages */
  58 #define ubi_warn(fmt, ...) printk(KERN_WARNING "UBI warning: %s: " fmt "\n", \
  59                                   __func__, ##__VA_ARGS__)
  60 /* UBI error messages */
  61 #define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \
  62                                  __func__, ##__VA_ARGS__)
  63
  64 /* Lowest number PEBs reserved for bad PEB handling */
  65 #define MIN_RESEVED_PEBS 2
  66
  67 /* Background thread name pattern */
  68 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
  69
  70 /* This marker in the EBA table means that the LEB is um-mapped */
  71 #define UBI_LEB_UNMAPPED -1
  72
  73 /*
  74  * In case of errors, UBI tries to repeat the operation several times before
  75  * returning error. The below constant defines how many times UBI re-tries.
  76  */
  77 #define UBI_IO_RETRIES 3
  78
  79 /*
  80  * Length of the protection queue. The length is effectively equivalent to the
  81  * number of (global) erase cycles PEBs are protected from the wear-leveling
  82  * worker.
  83  */
  84 #define UBI_PROT_QUEUE_LEN 10
  85
  86 /*
  87  * Error codes returned by the I/O sub-system.
  88  *
  89  * UBI_IO_FF: the read region of flash contains only 0xFFs
  90  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
  91  *                     integrity error reported by the MTD driver
  92  *                     (uncorrectable ECC error in case of NAND)
  93  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
  94  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
  95  *                         data integrity error reported by the MTD driver
  96  *                         (uncorrectable ECC error in case of NAND)
  97  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
  98  *
  99  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
 100  * be or'ed with other error code. But this is a big change because there are
 101  * may callers, so it does not worth the risk of introducing a bug
 102  */
 103 enum {
 104         UBI_IO_FF = 1,
 105         UBI_IO_FF_BITFLIPS,
 106         UBI_IO_BAD_HDR,
 107         UBI_IO_BAD_HDR_EBADMSG,
 108         UBI_IO_BITFLIPS,
 109 };
 110
 111 /*
 112  * Return codes of the 'ubi_eba_copy_leb()' function.
 113  *
 114  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
 115  *                   PEB was put meanwhile, or there is I/O on the source PEB
 116  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
 117  *                     PEB
 118  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
 119  *                     PEB
 120  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
 121  *                     PEB
 122  * MOVE_CANCEL_BITFLIPS: canceled because a bit-flip was detected in the
 123  *                       target 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 };
 132
 133 /**
 134  * struct ubi_wl_entry - wear-leveling entry.
 135  * @u.rb: link in the corresponding (free/used) RB-tree
 136  * @u.list: link in the protection queue
 137  * @ec: erase counter
 138  * @pnum: physical eraseblock number
 139  *
 140  * This data structure is used in the WL sub-system. Each physical eraseblock
 141  * has a corresponding &struct wl_entry object which may be kept in different
 142  * RB-trees. See WL sub-system for details.
 143  */
 144 struct ubi_wl_entry {
 145         union {
 146                 struct rb_node rb;
 147                 struct list_head list;
 148         } u;
 149         int ec;
 150         int pnum;
 151 };
 152
 153 /**
 154  * struct ubi_ltree_entry - an entry in the lock tree.
 155  * @rb: links RB-tree nodes
 156  * @vol_id: volume ID of the locked logical eraseblock
 157  * @lnum: locked logical eraseblock number
 158  * @users: how many tasks are using this logical eraseblock or wait for it
 159  * @mutex: read/write mutex to implement read/write access serialization to
 160  *         the (@vol_id, @lnum) logical eraseblock
 161  *
 162  * This data structure is used in the EBA sub-system to implement per-LEB
 163  * locking. When a logical eraseblock is being locked - corresponding
 164  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
 165  * See EBA sub-system for details.
 166  */
 167 struct ubi_ltree_entry {
 168         struct rb_node rb;
 169         int vol_id;
 170         int lnum;
 171         int users;
 172         struct rw_semaphore mutex;
 173 };
 174
 175 /**
 176  * struct ubi_rename_entry - volume re-name description data structure.
 177  * @new_name_len: new volume name length
 178  * @new_name: new volume name
 179  * @remove: if not zero, this volume should be removed, not re-named
 180  * @desc: descriptor of the volume
 181  * @list: links re-name entries into a list
 182  *
 183  * This data structure is utilized in the multiple volume re-name code. Namely,
 184  * UBI first creates a list of &struct ubi_rename_entry objects from the
 185  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
 186  * the job.
 187  */
 188 struct ubi_rename_entry {
 189         int new_name_len;
 190         char new_name[UBI_VOL_NAME_MAX + 1];
 191         int remove;
 192         struct ubi_volume_desc *desc;
 193         struct list_head list;
 194 };
 195
 196 struct ubi_volume_desc;
 197
 198 /**
 199  * struct ubi_volume - UBI volume description data structure.
 200  * @dev: device object to make use of the the Linux device model
 201  * @cdev: character device object to create character device
 202  * @ubi: reference to the UBI device description object
 203  * @vol_id: volume ID
 204  * @ref_count: volume reference count
 205  * @readers: number of users holding this volume in read-only mode
 206  * @writers: number of users holding this volume in read-write mode
 207  * @exclusive: whether somebody holds this volume in exclusive mode
 208  *
 209  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
 210  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
 211  * @usable_leb_size: logical eraseblock size without padding
 212  * @used_ebs: how many logical eraseblocks in this volume contain data
 213  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
 214  * @used_bytes: how many bytes of data this volume contains
 215  * @alignment: volume alignment
 216  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
 217  *            satisfy the requested alignment
 218  * @name_len: volume name length
 219  * @name: volume name
 220  *
 221  * @upd_ebs: how many eraseblocks are expected to be updated
 222  * @ch_lnum: LEB number which is being changing by the atomic LEB change
 223  *           operation
 224  * @ch_dtype: data persistency type which is being changing by the atomic LEB
 225  *            change operation
 226  * @upd_bytes: how many bytes are expected to be received for volume update or
 227  *             atomic LEB change
 228  * @upd_received: how many bytes were already received for volume update or
 229  *                atomic LEB change
 230  * @upd_buf: update buffer which is used to collect update data or data for
 231  *           atomic LEB change
 232  *
 233  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
 234  * @checked: %1 if this static volume was checked
 235  * @corrupted: %1 if the volume is corrupted (static volumes only)
 236  * @upd_marker: %1 if the update marker is set for this volume
 237  * @updating: %1 if the volume is being updated
 238  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
 239  * @direct_writes: %1 if direct writes are enabled for this volume
 240  *
 241  * The @corrupted field indicates that the volume's contents is corrupted.
 242  * Since UBI protects only static volumes, this field is not relevant to
 243  * dynamic volumes - it is user's responsibility to assure their data
 244  * integrity.
 245  *
 246  * The @upd_marker flag indicates that this volume is either being updated at
 247  * the moment or is damaged because of an unclean reboot.
 248  */
 249 struct ubi_volume {
 250         struct device dev;
 251         struct cdev cdev;
 252         struct ubi_device *ubi;
 253         int vol_id;
 254         int ref_count;
 255         int readers;
 256         int writers;
 257         int exclusive;
 258
 259         int reserved_pebs;
 260         int vol_type;
 261         int usable_leb_size;
 262         int used_ebs;
 263         int last_eb_bytes;
 264         long long used_bytes;
 265         int alignment;
 266         int data_pad;
 267         int name_len;
 268         char name[UBI_VOL_NAME_MAX + 1];
 269
 270         int upd_ebs;
 271         int ch_lnum;
 272         int ch_dtype;
 273         long long upd_bytes;
 274         long long upd_received;
 275         void *upd_buf;
 276
 277         int *eba_tbl;
 278         unsigned int checked:1;
 279         unsigned int corrupted:1;
 280         unsigned int upd_marker:1;
 281         unsigned int updating:1;
 282         unsigned int changing_leb:1;
 283         unsigned int direct_writes:1;
 284 };
 285
 286 /**
 287  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
 288  * @vol: reference to the corresponding volume description object
 289  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
 290  */
 291 struct ubi_volume_desc {
 292         struct ubi_volume *vol;
 293         int mode;
 294 };
 295
 296 struct ubi_wl_entry;
 297
 298 /**
 299  * struct ubi_device - UBI device description structure
 300  * @dev: UBI device object to use the the Linux device model
 301  * @cdev: character device object to create character device
 302  * @ubi_num: UBI device number
 303  * @ubi_name: UBI device name
 304  * @vol_count: number of volumes in this UBI device
 305  * @volumes: volumes of this UBI device
 306  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
 307  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
 308  *                @vol->readers, @vol->writers, @vol->exclusive,
 309  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
 310  * @ref_count: count of references on the UBI device
 311  * @image_seq: image sequence number recorded on EC headers
 312  *
 313  * @rsvd_pebs: count of reserved physical eraseblocks
 314  * @avail_pebs: count of available physical eraseblocks
 315  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
 316  *                 handling
 317  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
 318  *
 319  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
 320  *                     of UBI initialization
 321  * @vtbl_slots: how many slots are available in the volume table
 322  * @vtbl_size: size of the volume table in bytes
 323  * @vtbl: in-RAM volume table copy
 324  * @device_mutex: protects on-flash volume table and serializes volume
 325  *                creation, deletion, update, re-size, re-name and set
 326  *                property
 327  *
 328  * @max_ec: current highest erase counter value
 329  * @mean_ec: current mean erase counter value
 330  *
 331  * @global_sqnum: global sequence number
 332  * @ltree_lock: protects the lock tree and @global_sqnum
 333  * @ltree: the lock tree
 334  * @alc_mutex: serializes "atomic LEB change" operations
 335  *
 336  * @used: RB-tree of used physical eraseblocks
 337  * @erroneous: RB-tree of erroneous used physical eraseblocks
 338  * @free: RB-tree of free physical eraseblocks
 339  * @scrub: RB-tree of physical eraseblocks which need scrubbing
 340  * @pq: protection queue (contain physical eraseblocks which are temporarily
 341  *      protected from the wear-leveling worker)
 342  * @pq_head: protection queue head
 343  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
 344  *           @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
 345  *           @erroneous, and @erroneous_peb_count fields
 346  * @move_mutex: serializes eraseblock moves
 347  * @work_sem: synchronizes the WL worker with use tasks
 348  * @wl_scheduled: non-zero if the wear-leveling was scheduled
 349  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
 350  *             physical eraseblock
 351  * @move_from: physical eraseblock from where the data is being moved
 352  * @move_to: physical eraseblock where the data is being moved to
 353  * @move_to_put: if the "to" PEB was put
 354  * @works: list of pending works
 355  * @works_count: count of pending works
 356  * @bgt_thread: background thread description object
 357  * @thread_enabled: if the background thread is enabled
 358  * @bgt_name: background thread name
 359  *
 360  * @flash_size: underlying MTD device size (in bytes)
 361  * @peb_count: count of physical eraseblocks on the MTD device
 362  * @peb_size: physical eraseblock size
 363  * @bad_peb_count: count of bad physical eraseblocks
 364  * @good_peb_count: count of good physical eraseblocks
 365  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
 366  *                  used by UBI)
 367  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
 368  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
 369  * @min_io_size: minimal input/output unit size of the underlying MTD device
 370  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
 371  * @ro_mode: if the UBI device is in read-only mode
 372  * @leb_size: logical eraseblock size
 373  * @leb_start: starting offset of logical eraseblocks within physical
 374  *             eraseblocks
 375  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
 376  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
 377  * @vid_hdr_offset: starting offset of the volume identifier header (might be
 378  *                  unaligned)
 379  * @vid_hdr_aloffset: starting offset of the VID header aligned to
 380  * @hdrs_min_io_size
 381  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
 382  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
 383  *               not
 384  * @nor_flash: non-zero if working on top of NOR flash
 385  * @max_write_size: maximum amount of bytes the underlying flash can write at a
 386  *                  time (MTD write buffer size)
 387  * @mtd: MTD device descriptor
 388  *
 389  * @peb_buf1: a buffer of PEB size used for different purposes
 390  * @peb_buf2: another buffer of PEB size used for different purposes
 391  * @buf_mutex: protects @peb_buf1 and @peb_buf2
 392  * @ckvol_mutex: serializes static volume checking when opening
 393  */
 394 struct ubi_device {
 395         struct cdev cdev;
 396         struct device dev;
 397         int ubi_num;
 398         char ubi_name[sizeof(UBI_NAME_STR)+5];
 399         int vol_count;
 400         struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
 401         spinlock_t volumes_lock;
 402         int ref_count;
 403         int image_seq;
 404
 405         int rsvd_pebs;
 406         int avail_pebs;
 407         int beb_rsvd_pebs;
 408         int beb_rsvd_level;
 409
 410         int autoresize_vol_id;
 411         int vtbl_slots;
 412         int vtbl_size;
 413         struct ubi_vtbl_record *vtbl;
 414         struct mutex device_mutex;
 415
 416         int max_ec;
 417         /* Note, mean_ec is not updated run-time - should be fixed */
 418         int mean_ec;
 419
 420         /* EBA sub-system's stuff */
 421         unsigned long long global_sqnum;
 422         spinlock_t ltree_lock;
 423         struct rb_root ltree;
 424         struct mutex alc_mutex;
 425
 426         /* Wear-leveling sub-system's stuff */
 427         struct rb_root used;
 428         struct rb_root erroneous;
 429         struct rb_root free;
 430         struct rb_root scrub;
 431         struct list_head pq[UBI_PROT_QUEUE_LEN];
 432         int pq_head;
 433         spinlock_t wl_lock;
 434         struct mutex move_mutex;
 435         struct rw_semaphore work_sem;
 436         int wl_scheduled;
 437         struct ubi_wl_entry **lookuptbl;
 438         struct ubi_wl_entry *move_from;
 439         struct ubi_wl_entry *move_to;
 440         int move_to_put;
 441         struct list_head works;
 442         int works_count;
 443         struct task_struct *bgt_thread;
 444         int thread_enabled;
 445         char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
 446
 447         /* I/O sub-system's stuff */
 448         long long flash_size;
 449         int peb_count;
 450         int peb_size;
 451         int bad_peb_count;
 452         int good_peb_count;
 453         int corr_peb_count;
 454         int erroneous_peb_count;
 455         int max_erroneous;
 456         int min_io_size;
 457         int hdrs_min_io_size;
 458         int ro_mode;
 459         int leb_size;
 460         int leb_start;
 461         int ec_hdr_alsize;
 462         int vid_hdr_alsize;
 463         int vid_hdr_offset;
 464         int vid_hdr_aloffset;
 465         int vid_hdr_shift;
 466         unsigned int bad_allowed:1;
 467         unsigned int nor_flash:1;
 468         int max_write_size;
 469         struct mtd_info *mtd;
 470
 471         void *peb_buf1;
 472         void *peb_buf2;
 473         struct mutex buf_mutex;
 474         struct mutex ckvol_mutex;
 475 };
 476
 477 extern struct kmem_cache *ubi_wl_entry_slab;
 478 extern const struct file_operations ubi_ctrl_cdev_operations;
 479 extern const struct file_operations ubi_cdev_operations;
 480 extern const struct file_operations ubi_vol_cdev_operations;
 481 extern struct class *ubi_class;
 482 extern struct mutex ubi_devices_mutex;
 483 extern struct blocking_notifier_head ubi_notifiers;
 484
 485 /* vtbl.c */
 486 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 487                            struct ubi_vtbl_record *vtbl_rec);
 488 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
 489                             struct list_head *rename_list);
 490 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
 491
 492 /* vmt.c */
 493 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
 494 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
 495 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
 496 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
 497 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 498 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 499
 500 /* upd.c */
 501 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
 502                      long long bytes);
 503 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
 504                          const void __user *buf, int count);
 505 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 506                          const struct ubi_leb_change_req *req);
 507 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
 508                              const void __user *buf, int count);
 509
 510 /* misc.c */
 511 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
 512                       int length);
 513 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 514 void ubi_calculate_reserved(struct ubi_device *ubi);
 515 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
 516
 517 /* eba.c */
 518 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 519                       int lnum);
 520 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 521                      void *buf, int offset, int len, int check);
 522 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 523                       const void *buf, int offset, int len, int dtype);
 524 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 525                          int lnum, const void *buf, int len, int dtype,
 526                          int used_ebs);
 527 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 528                               int lnum, const void *buf, int len, int dtype);
 529 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 530                      struct ubi_vid_hdr *vid_hdr);
 531 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 532
 533 /* wl.c */
 534 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
 535 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
 536 int ubi_wl_flush(struct ubi_device *ubi);
 537 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
 538 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 539 void ubi_wl_close(struct ubi_device *ubi);
 540 int ubi_thread(void *u);
 541
 542 /* io.c */
 543 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
 544                 int len);
 545 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
 546                  int len);
 547 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
 548 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
 549 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
 550 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 551                        struct ubi_ec_hdr *ec_hdr, int verbose);
 552 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
 553                         struct ubi_ec_hdr *ec_hdr);
 554 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 555                         struct ubi_vid_hdr *vid_hdr, int verbose);
 556 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
 557                          struct ubi_vid_hdr *vid_hdr);
 558
 559 /* build.c */
 560 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
 561 int ubi_detach_mtd_dev(int ubi_num, int anyway);
 562 struct ubi_device *ubi_get_device(int ubi_num);
 563 void ubi_put_device(struct ubi_device *ubi);
 564 struct ubi_device *ubi_get_by_major(int major);
 565 int ubi_major2num(int major);
 566 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
 567                       int ntype);
 568 int ubi_notify_all(struct ubi_device *ubi, int ntype,
 569                    struct notifier_block *nb);
 570 int ubi_enumerate_volumes(struct notifier_block *nb);
 571
 572 /* kapi.c */
 573 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
 574 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
 575                             struct ubi_volume_info *vi);
 576
 577 /*
 578  * ubi_rb_for_each_entry - walk an RB-tree.
 579  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
 580  * @pos: a pointer to RB-tree entry type to use as a loop counter
 581  * @root: RB-tree's root
 582  * @member: the name of the 'struct rb_node' within the RB-tree entry
 583  */
 584 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
 585         for (rb = rb_first(root),                                            \
 586              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
 587              rb;                                                             \
 588              rb = rb_next(rb),                                               \
 589              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
 590
 591 /**
 592  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
 593  * @ubi: UBI device description object
 594  * @gfp_flags: GFP flags to allocate with
 595  *
 596  * This function returns a pointer to the newly allocated and zero-filled
 597  * volume identifier header object in case of success and %NULL in case of
 598  * failure.
 599  */
 600 static inline struct ubi_vid_hdr *
 601 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
 602 {
 603         void *vid_hdr;
 604
 605         vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
 606         if (!vid_hdr)
 607                 return NULL;
 608
 609         /*
 610          * VID headers may be stored at un-aligned flash offsets, so we shift
 611          * the pointer.
 612          */
 613         return vid_hdr + ubi->vid_hdr_shift;
 614 }
 615
 616 /**
 617  * ubi_free_vid_hdr - free a volume identifier header object.
 618  * @ubi: UBI device description object
 619  * @vid_hdr: the object to free
 620  */
 621 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
 622                                     struct ubi_vid_hdr *vid_hdr)
 623 {
 624         void *p = vid_hdr;
 625
 626         if (!p)
 627                 return;
 628
 629         kfree(p - ubi->vid_hdr_shift);
 630 }
 631
 632 /*
 633  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
 634  * the beginning of the logical eraseblock, not to the beginning of the
 635  * physical eraseblock.
 636  */
 637 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
 638                                    int pnum, int offset, int len)
 639 {
 640         ubi_assert(offset >= 0);
 641         return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
 642 }
 643
 644 /*
 645  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
 646  * the beginning of the logical eraseblock, not to the beginning of the
 647  * physical eraseblock.
 648  */
 649 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
 650                                     int pnum, int offset, int len)
 651 {
 652         ubi_assert(offset >= 0);
 653         return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
 654 }
 655
 656 /**
 657  * ubi_ro_mode - switch to read-only mode.
 658  * @ubi: UBI device description object
 659  */
 660 static inline void ubi_ro_mode(struct ubi_device *ubi)
 661 {
 662         if (!ubi->ro_mode) {
 663                 ubi->ro_mode = 1;
 664                 ubi_warn("switch to read-only mode");
 665         }
 666 }
 667
 668 /**
 669  * vol_id2idx - get table index by volume ID.
 670  * @ubi: UBI device description object
 671  * @vol_id: volume ID
 672  */
 673 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
 674 {
 675         if (vol_id >= UBI_INTERNAL_VOL_START)
 676                 return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
 677         else
 678                 return vol_id;
 679 }
 680
 681 /**
 682  * idx2vol_id - get volume ID by table index.
 683  * @ubi: UBI device description object
 684  * @idx: table index
 685  */
 686 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
 687 {
 688         if (idx >= ubi->vtbl_slots)
 689                 return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
 690         else
 691                 return idx;
 692 }
 693
 694 #endif /* !__UBI_UBI_H__ */