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  *
 148  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
 149  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
 150  * @usable_leb_size: logical eraseblock size without padding
 151  * @used_ebs: how many logical eraseblocks in this volume contain data
 152  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
 153  * @used_bytes: how many bytes of data this volume contains
 154  * @alignment: volume alignment
 155  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
 156  *            satisfy the requested alignment
 157  * @name_len: volume name length
 158  * @name: volume name
 159  *
 160  * @upd_ebs: how many eraseblocks are expected to be updated
 161  * @ch_lnum: LEB number which is being changing by the atomic LEB change
 162  *           operation
 163  * @ch_dtype: data persistency type which is being changing by the atomic LEB
 164  *            change operation
 165  * @upd_bytes: how many bytes are expected to be received for volume update or
 166  *             atomic LEB change
 167  * @upd_received: how many bytes were already received for volume update or
 168  *                atomic LEB change
 169  * @upd_buf: update buffer which is used to collect update data or data for
 170  *           atomic LEB change
 171  *
 172  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
 173  * @checked: %1 if this static volume was checked
 174  * @corrupted: %1 if the volume is corrupted (static volumes only)
 175  * @upd_marker: %1 if the update marker is set for this volume
 176  * @updating: %1 if the volume is being updated
 177  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
 178  *
 179  * @gluebi_desc: gluebi UBI volume descriptor
 180  * @gluebi_refcount: reference count of the gluebi MTD device
 181  * @gluebi_mtd: MTD device description object of the gluebi MTD device
 182  *
 183  * The @corrupted field indicates that the volume's contents is corrupted.
 184  * Since UBI protects only static volumes, this field is not relevant to
 185  * dynamic volumes - it is user's responsibility to assure their data
 186  * integrity.
 187  *
 188  * The @upd_marker flag indicates that this volume is either being updated at
 189  * the moment or is damaged because of an unclean reboot.
 190  */
 191 struct ubi_volume {
 192         struct device dev;
 193         struct cdev cdev;
 194         struct ubi_device *ubi;
 195         int vol_id;
 196         int ref_count;
 197         int readers;
 198         int writers;
 199         int exclusive;
 200
 201         int reserved_pebs;
 202         int vol_type;
 203         int usable_leb_size;
 204         int used_ebs;
 205         int last_eb_bytes;
 206         long long used_bytes;
 207         int alignment;
 208         int data_pad;
 209         int name_len;
 210         char name[UBI_VOL_NAME_MAX+1];
 211
 212         int upd_ebs;
 213         int ch_lnum;
 214         int ch_dtype;
 215         long long upd_bytes;
 216         long long upd_received;
 217         void *upd_buf;
 218
 219         int *eba_tbl;
 220 <<<<<<< HEAD:drivers/mtd/ubi/ubi.h
 221         int checked:1;
 222         int corrupted:1;
 223         int upd_marker:1;
 224         int updating:1;
 225         int changing_leb:1;
 226 =======
 227         unsigned int checked:1;
 228         unsigned int corrupted:1;
 229         unsigned int upd_marker:1;
 230         unsigned int updating:1;
 231         unsigned int changing_leb:1;
 232 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/mtd/ubi/ubi.h
 233
 234 #ifdef CONFIG_MTD_UBI_GLUEBI
 235         /*
 236          * Gluebi-related stuff may be compiled out.
 237          * TODO: this should not be built into UBI but should be a separate
 238          * ubimtd driver which works on top of UBI and emulates MTD devices.
 239          */
 240         struct ubi_volume_desc *gluebi_desc;
 241         int gluebi_refcount;
 242         struct mtd_info gluebi_mtd;
 243 #endif
 244 };
 245
 246 /**
 247  * struct ubi_volume_desc - descriptor of the UBI volume returned when it is
 248  * opened.
 249  * @vol: reference to the corresponding volume description object
 250  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
 251  */
 252 struct ubi_volume_desc {
 253         struct ubi_volume *vol;
 254         int mode;
 255 };
 256
 257 struct ubi_wl_entry;
 258
 259 /**
 260  * struct ubi_device - UBI device description structure
 261  * @dev: UBI device object to use the the Linux device model
 262  * @cdev: character device object to create character device
 263  * @ubi_num: UBI device number
 264  * @ubi_name: UBI device name
 265  * @vol_count: number of volumes in this UBI device
 266  * @volumes: volumes of this UBI device
 267  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
 268  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
 269  *                @vol->readers, @vol->writers, @vol->exclusive,
 270  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
 271  * @ref_count: count of references on the UBI device
 272  *
 273  * @rsvd_pebs: count of reserved physical eraseblocks
 274  * @avail_pebs: count of available physical eraseblocks
 275  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
 276  *                 handling
 277  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
 278  *
 279  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
 280  *                     of UBI ititializetion
 281  * @vtbl_slots: how many slots are available in the volume table
 282  * @vtbl_size: size of the volume table in bytes
 283  * @vtbl: in-RAM volume table copy
 284  * @volumes_mutex: protects on-flash volume table and serializes volume
 285  *                 changes, like creation, deletion, update, resize
 286  *
 287  * @max_ec: current highest erase counter value
 288  * @mean_ec: current mean erase counter value
 289  *
 290  * @global_sqnum: global sequence number
 291  * @ltree_lock: protects the lock tree and @global_sqnum
 292  * @ltree: the lock tree
 293  * @alc_mutex: serializes "atomic LEB change" operations
 294  *
 295  * @used: RB-tree of used physical eraseblocks
 296  * @free: RB-tree of free physical eraseblocks
 297  * @scrub: RB-tree of physical eraseblocks which need scrubbing
 298  * @prot: protection trees
 299  * @prot.pnum: protection tree indexed by physical eraseblock numbers
 300  * @prot.aec: protection tree indexed by absolute erase counter value
 301  * @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from,
 302  *           @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works
 303  *           fields
 304  * @move_mutex: serializes eraseblock moves
 305  * @wl_scheduled: non-zero if the wear-leveling was scheduled
 306  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
 307  *             physical eraseblock
 308  * @abs_ec: absolute erase counter
 309  * @move_from: physical eraseblock from where the data is being moved
 310  * @move_to: physical eraseblock where the data is being moved to
 311  * @move_to_put: if the "to" PEB was put
 312  * @works: list of pending works
 313  * @works_count: count of pending works
 314  * @bgt_thread: background thread description object
 315  * @thread_enabled: if the background thread is enabled
 316  * @bgt_name: background thread name
 317  *
 318  * @flash_size: underlying MTD device size (in bytes)
 319  * @peb_count: count of physical eraseblocks on the MTD device
 320  * @peb_size: physical eraseblock size
 321  * @bad_peb_count: count of bad physical eraseblocks
 322  * @good_peb_count: count of good physical eraseblocks
 323  * @min_io_size: minimal input/output unit size of the underlying MTD device
 324  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
 325  * @ro_mode: if the UBI device is in read-only mode
 326  * @leb_size: logical eraseblock size
 327  * @leb_start: starting offset of logical eraseblocks within physical
 328  * eraseblocks
 329  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
 330  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
 331  * @vid_hdr_offset: starting offset of the volume identifier header (might be
 332  * unaligned)
 333  * @vid_hdr_aloffset: starting offset of the VID header aligned to
 334  * @hdrs_min_io_size
 335  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
 336  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
 337  *               not
 338  * @mtd: MTD device descriptor
 339  *
 340  * @peb_buf1: a buffer of PEB size used for different purposes
 341  * @peb_buf2: another buffer of PEB size used for different purposes
 342  * @buf_mutex: proptects @peb_buf1 and @peb_buf2
 343  * @dbg_peb_buf: buffer of PEB size used for debugging
 344  * @dbg_buf_mutex: proptects @dbg_peb_buf
 345  */
 346 struct ubi_device {
 347         struct cdev cdev;
 348         struct device dev;
 349         int ubi_num;
 350         char ubi_name[sizeof(UBI_NAME_STR)+5];
 351         int vol_count;
 352         struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
 353         spinlock_t volumes_lock;
 354         int ref_count;
 355
 356         int rsvd_pebs;
 357         int avail_pebs;
 358         int beb_rsvd_pebs;
 359         int beb_rsvd_level;
 360
 361         int autoresize_vol_id;
 362         int vtbl_slots;
 363         int vtbl_size;
 364         struct ubi_vtbl_record *vtbl;
 365         struct mutex volumes_mutex;
 366
 367         int max_ec;
 368         /* TODO: mean_ec is not updated run-time, fix */
 369         int mean_ec;
 370
 371         /* EBA unit's stuff */
 372         unsigned long long global_sqnum;
 373         spinlock_t ltree_lock;
 374         struct rb_root ltree;
 375         struct mutex alc_mutex;
 376
 377         /* Wear-leveling unit's stuff */
 378         struct rb_root used;
 379         struct rb_root free;
 380         struct rb_root scrub;
 381         struct {
 382                 struct rb_root pnum;
 383                 struct rb_root aec;
 384         } prot;
 385         spinlock_t wl_lock;
 386         struct mutex move_mutex;
 387         struct rw_semaphore work_sem;
 388         int wl_scheduled;
 389         struct ubi_wl_entry **lookuptbl;
 390         unsigned long long abs_ec;
 391         struct ubi_wl_entry *move_from;
 392         struct ubi_wl_entry *move_to;
 393         int move_to_put;
 394         struct list_head works;
 395         int works_count;
 396         struct task_struct *bgt_thread;
 397         int thread_enabled;
 398         char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
 399
 400         /* I/O unit's stuff */
 401         long long flash_size;
 402         int peb_count;
 403         int peb_size;
 404         int bad_peb_count;
 405         int good_peb_count;
 406         int min_io_size;
 407         int hdrs_min_io_size;
 408         int ro_mode;
 409         int leb_size;
 410         int leb_start;
 411         int ec_hdr_alsize;
 412         int vid_hdr_alsize;
 413         int vid_hdr_offset;
 414         int vid_hdr_aloffset;
 415         int vid_hdr_shift;
 416         int bad_allowed;
 417         struct mtd_info *mtd;
 418
 419         void *peb_buf1;
 420         void *peb_buf2;
 421         struct mutex buf_mutex;
 422         struct mutex ckvol_mutex;
 423 #ifdef CONFIG_MTD_UBI_DEBUG
 424         void *dbg_peb_buf;
 425         struct mutex dbg_buf_mutex;
 426 #endif
 427 };
 428
 429 extern struct kmem_cache *ubi_wl_entry_slab;
 430 extern struct file_operations ubi_ctrl_cdev_operations;
 431 extern struct file_operations ubi_cdev_operations;
 432 extern struct file_operations ubi_vol_cdev_operations;
 433 extern struct class *ubi_class;
 434 extern struct mutex ubi_devices_mutex;
 435
 436 /* vtbl.c */
 437 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 438                            struct ubi_vtbl_record *vtbl_rec);
 439 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
 440
 441 /* vmt.c */
 442 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
 443 int ubi_remove_volume(struct ubi_volume_desc *desc);
 444 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
 445 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 446 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 447
 448 /* upd.c */
 449 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
 450                      long long bytes);
 451 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
 452                          const void __user *buf, int count);
 453 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 454                          const struct ubi_leb_change_req *req);
 455 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
 456                              const void __user *buf, int count);
 457
 458 /* misc.c */
 459 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length);
 460 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 461 void ubi_calculate_reserved(struct ubi_device *ubi);
 462
 463 /* gluebi.c */
 464 #ifdef CONFIG_MTD_UBI_GLUEBI
 465 int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol);
 466 int ubi_destroy_gluebi(struct ubi_volume *vol);
 467 void ubi_gluebi_updated(struct ubi_volume *vol);
 468 #else
 469 #define ubi_create_gluebi(ubi, vol) 0
 470 #define ubi_destroy_gluebi(vol) 0
 471 #define ubi_gluebi_updated(vol)
 472 #endif
 473
 474 /* eba.c */
 475 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 476                       int lnum);
 477 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 478                      void *buf, int offset, int len, int check);
 479 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 480                       const void *buf, int offset, int len, int dtype);
 481 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 482                          int lnum, const void *buf, int len, int dtype,
 483                          int used_ebs);
 484 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 485                               int lnum, const void *buf, int len, int dtype);
 486 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 487                      struct ubi_vid_hdr *vid_hdr);
 488 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 489 void ubi_eba_close(const struct ubi_device *ubi);
 490
 491 /* wl.c */
 492 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
 493 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
 494 int ubi_wl_flush(struct ubi_device *ubi);
 495 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
 496 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 497 void ubi_wl_close(struct ubi_device *ubi);
 498 int ubi_thread(void *u);
 499
 500 /* io.c */
 501 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
 502                 int len);
 503 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
 504                  int len);
 505 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
 506 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
 507 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
 508 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 509                        struct ubi_ec_hdr *ec_hdr, int verbose);
 510 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
 511                         struct ubi_ec_hdr *ec_hdr);
 512 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 513                         struct ubi_vid_hdr *vid_hdr, int verbose);
 514 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
 515                          struct ubi_vid_hdr *vid_hdr);
 516
 517 /* build.c */
 518 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
 519 int ubi_detach_mtd_dev(int ubi_num, int anyway);
 520 struct ubi_device *ubi_get_device(int ubi_num);
 521 void ubi_put_device(struct ubi_device *ubi);
 522 struct ubi_device *ubi_get_by_major(int major);
 523 int ubi_major2num(int major);
 524
 525 /*
 526  * ubi_rb_for_each_entry - walk an RB-tree.
 527  * @rb: a pointer to type 'struct rb_node' to to use as a loop counter
 528  * @pos: a pointer to RB-tree entry type to use as a loop counter
 529  * @root: RB-tree's root
 530  * @member: the name of the 'struct rb_node' within the RB-tree entry
 531  */
 532 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
 533         for (rb = rb_first(root),                                            \
 534              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
 535              rb;                                                             \
 536              rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member))
 537
 538 /**
 539  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
 540  * @ubi: UBI device description object
 541  * @gfp_flags: GFP flags to allocate with
 542  *
 543  * This function returns a pointer to the newly allocated and zero-filled
 544  * volume identifier header object in case of success and %NULL in case of
 545  * failure.
 546  */
 547 static inline struct ubi_vid_hdr *
 548 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
 549 {
 550         void *vid_hdr;
 551
 552         vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
 553         if (!vid_hdr)
 554                 return NULL;
 555
 556         /*
 557          * VID headers may be stored at un-aligned flash offsets, so we shift
 558          * the pointer.
 559          */
 560         return vid_hdr + ubi->vid_hdr_shift;
 561 }
 562
 563 /**
 564  * ubi_free_vid_hdr - free a volume identifier header object.
 565  * @ubi: UBI device description object
 566  * @vid_hdr: the object to free
 567  */
 568 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
 569                                     struct ubi_vid_hdr *vid_hdr)
 570 {
 571         void *p = vid_hdr;
 572
 573         if (!p)
 574                 return;
 575
 576         kfree(p - ubi->vid_hdr_shift);
 577 }
 578
 579 /*
 580  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
 581  * the beginning of the logical eraseblock, not to the beginning of the
 582  * physical eraseblock.
 583  */
 584 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
 585                                    int pnum, int offset, int len)
 586 {
 587         ubi_assert(offset >= 0);
 588         return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
 589 }
 590
 591 /*
 592  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
 593  * the beginning of the logical eraseblock, not to the beginning of the
 594  * physical eraseblock.
 595  */
 596 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
 597                                     int pnum, int offset, int len)
 598 {
 599         ubi_assert(offset >= 0);
 600         return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
 601 }
 602
 603 /**
 604  * ubi_ro_mode - switch to read-only mode.
 605  * @ubi: UBI device description object
 606  */
 607 static inline void ubi_ro_mode(struct ubi_device *ubi)
 608 {
 609         if (!ubi->ro_mode) {
 610                 ubi->ro_mode = 1;
 611                 ubi_warn("switch to read-only mode");
 612         }
 613 }
 614
 615 /**
 616  * vol_id2idx - get table index by volume ID.
 617  * @ubi: UBI device description object
 618  * @vol_id: volume ID
 619  */
 620 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
 621 {
 622         if (vol_id >= UBI_INTERNAL_VOL_START)
 623                 return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
 624         else
 625                 return vol_id;
 626 }
 627
 628 /**
 629  * idx2vol_id - get volume ID by table index.
 630  * @ubi: UBI device description object
 631  * @idx: table index
 632  */
 633 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
 634 {
 635         if (idx >= ubi->vtbl_slots)
 636                 return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
 637         else
 638                 return idx;
 639 }
 640
 641 #endif /* !__UBI_UBI_H__ */