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