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