drivers/mtd/ubi/ubi.h

   1 /*
   2  * Copyright (c) International Business Machines Corp., 2006
   3  * Copyright (c) Nokia Corporation, 2006, 2007
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  13  * the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18  *
  19  * Author: Artem Bityutskiy (Битюцкий Артём)
  20  */
  21
  22 #ifndef __UBI_UBI_H__
  23 #define __UBI_UBI_H__
  24
  25 #include <linux/init.h>
  26 #include <linux/types.h>
  27 #include <linux/list.h>
  28 #include <linux/rbtree.h>
  29 #include <linux/sched.h>
  30 #include <linux/wait.h>
  31 #include <linux/mutex.h>
  32 #include <linux/rwsem.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/fs.h>
  35 #include <linux/cdev.h>
  36 #include <linux/device.h>
  37 #include <linux/string.h>
  38 #include <linux/vmalloc.h>
  39 #include <linux/mtd/mtd.h>
  40 #include <linux/mtd/ubi.h>
  41
  42 #include "ubi-media.h"
  43 #include "scan.h"
  44 #include "debug.h"
  45
  46 /* Maximum number of supported UBI devices */
  47 #define UBI_MAX_DEVICES 32
  48
  49 /* UBI name used for character devices, sysfs, etc */
  50 #define UBI_NAME_STR "ubi"
  51
  52 /* Normal UBI messages */
  53 #define ubi_msg(fmt, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__)
  54 /* UBI warning messages */
  55 #define ubi_warn(fmt, ...) printk(KERN_WARNING "UBI warning: %s: " fmt "\n", \
  56                                   __func__, ##__VA_ARGS__)
  57 /* UBI error messages */
  58 #define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \
  59                                  __func__, ##__VA_ARGS__)
  60
  61 /* Lowest number PEBs reserved for bad PEB handling */
  62 #define MIN_RESEVED_PEBS 2
  63
  64 /* Background thread name pattern */
  65 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
  66
  67 /* This marker in the EBA table means that the LEB is um-mapped */
  68 #define UBI_LEB_UNMAPPED -1
  69
  70 /*
  71  * In case of errors, UBI tries to repeat the operation several times before
  72  * returning error. The below constant defines how many times UBI re-tries.
  73  */
  74 #define UBI_IO_RETRIES 3
  75
  76 /*
  77  * Error codes returned by the I/O unit.
  78  *
  79  * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only
  80  * 0xFF bytes
  81  * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a
  82  * valid erase counter header, and the rest are %0xFF bytes
  83  * UBI_IO_BAD_EC_HDR: the erase counter header is corrupted (bad magic or CRC)
  84  * UBI_IO_BAD_VID_HDR: the volume identifier header is corrupted (bad magic or
  85  * CRC)
  86  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
  87  */
  88 enum {
  89         UBI_IO_PEB_EMPTY = 1,
  90         UBI_IO_PEB_FREE,
  91         UBI_IO_BAD_EC_HDR,
  92         UBI_IO_BAD_VID_HDR,
  93         UBI_IO_BITFLIPS
  94 };
  95
  96 /**
  97  * struct ubi_wl_entry - wear-leveling entry.
  98  * @rb: link in the corresponding RB-tree
  99  * @ec: erase counter
 100  * @pnum: physical eraseblock number
 101  *
 102  * This data structure is used in the WL unit. Each physical eraseblock has a
 103  * corresponding &struct wl_entry object which may be kept in different
 104  * RB-trees. See WL unit for details.
 105  */
 106 struct ubi_wl_entry {
 107         struct rb_node rb;
 108         int ec;
 109         int pnum;
 110 };
 111
 112 /**
 113  * struct ubi_ltree_entry - an entry in the lock tree.
 114  * @rb: links RB-tree nodes
 115  * @vol_id: volume ID of the locked logical eraseblock
 116  * @lnum: locked logical eraseblock number
 117  * @users: how many tasks are using this logical eraseblock or wait for it
 118  * @mutex: read/write mutex to implement read/write access serialization to
 119  *         the (@vol_id, @lnum) logical eraseblock
 120  *
 121  * This data structure is used in the EBA unit to implement per-LEB locking.
 122  * When a logical eraseblock is being locked - corresponding
 123  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
 124  * See EBA unit for details.
 125  */
 126 struct ubi_ltree_entry {
 127         struct rb_node rb;
 128         int vol_id;
 129         int lnum;
 130         int users;
 131         struct rw_semaphore mutex;
 132 };
 133
 134 struct ubi_volume_desc;
 135
 136 /**
 137  * struct ubi_volume - UBI volume description data structure.
 138  * @dev: device object to make use of the the Linux device model
 139  * @cdev: character device object to create character device
 140  * @ubi: reference to the UBI device description object
 141  * @vol_id: volume ID
 142  * @ref_count: volume reference count
 143  * @readers: number of users holding this volume in read-only mode
 144  * @writers: number of users holding this volume in read-write mode
 145  * @exclusive: whether somebody holds this volume in exclusive mode
 146  *
 147  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
 148  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
 149  * @usable_leb_size: logical eraseblock size without padding
 150  * @used_ebs: how many logical eraseblocks in this volume contain data
 151  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
 152  * @used_bytes: how many bytes of data this volume contains
 153  * @alignment: volume alignment
 154  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
 155  *            satisfy the requested alignment
 156  * @name_len: volume name length
 157  * @name: volume name
 158  *
 159  * @upd_ebs: how many eraseblocks are expected to be updated
 160  * @ch_lnum: LEB number which is being changing by the atomic LEB change
 161  *           operation
 162  * @ch_dtype: data persistency type which is being changing by the atomic LEB
 163  *            change operation
 164  * @upd_bytes: how many bytes are expected to be received for volume update or
 165  *             atomic LEB change
 166  * @upd_received: how many bytes were already received for volume update or
 167  *                atomic LEB change
 168  * @upd_buf: update buffer which is used to collect update data or data for
 169  *           atomic LEB change
 170  *
 171  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
 172  * @checked: %1 if this static volume was checked
 173  * @corrupted: %1 if the volume is corrupted (static volumes only)
 174  * @upd_marker: %1 if the update marker is set for this volume
 175  * @updating: %1 if the volume is being updated
 176  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
 177  *
 178  * @gluebi_desc: gluebi UBI volume descriptor
 179  * @gluebi_refcount: reference count of the gluebi MTD device
 180  * @gluebi_mtd: MTD device description object of the gluebi MTD device
 181  *
 182  * The @corrupted field indicates that the volume's contents is corrupted.
 183  * Since UBI protects only static volumes, this field is not relevant to
 184  * dynamic volumes - it is user's responsibility to assure their data
 185  * integrity.
 186  *
 187  * The @upd_marker flag indicates that this volume is either being updated at
 188  * the moment or is damaged because of an unclean reboot.
 189  */
 190 struct ubi_volume {
 191         struct device dev;
 192         struct cdev cdev;
 193         struct ubi_device *ubi;
 194         int vol_id;
 195         int ref_count;
 196         int readers;
 197         int writers;
 198         int exclusive;
 199
 200         int reserved_pebs;
 201         int vol_type;
 202         int usable_leb_size;
 203         int used_ebs;
 204         int last_eb_bytes;
 205         long long used_bytes;
 206         int alignment;
 207         int data_pad;
 208         int name_len;
 209         char name[UBI_VOL_NAME_MAX+1];
 210
 211         int upd_ebs;
 212         int ch_lnum;
 213         int ch_dtype;
 214         long long upd_bytes;
 215         long long upd_received;
 216         void *upd_buf;
 217
 218         int *eba_tbl;
 219         unsigned int checked:1;
 220         unsigned int corrupted:1;
 221         unsigned int upd_marker:1;
 222         unsigned int updating:1;
 223         unsigned int changing_leb:1;
 224
 225 #ifdef CONFIG_MTD_UBI_GLUEBI
 226         /*
 227          * Gluebi-related stuff may be compiled out.
 228          * TODO: this should not be built into UBI but should be a separate
 229          * ubimtd driver which works on top of UBI and emulates MTD devices.
 230          */
 231         struct ubi_volume_desc *gluebi_desc;
 232         int gluebi_refcount;
 233         struct mtd_info gluebi_mtd;
 234 #endif
 235 };
 236
 237 /**
 238  * struct ubi_volume_desc - descriptor of the UBI volume returned when it is
 239  * opened.
 240  * @vol: reference to the corresponding volume description object
 241  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
 242  */
 243 struct ubi_volume_desc {
 244         struct ubi_volume *vol;
 245         int mode;
 246 };
 247
 248 struct ubi_wl_entry;
 249
 250 /**
 251  * struct ubi_device - UBI device description structure
 252  * @dev: UBI device object to use the the Linux device model
 253  * @cdev: character device object to create character device
 254  * @ubi_num: UBI device number
 255  * @ubi_name: UBI device name
 256  * @vol_count: number of volumes in this UBI device
 257  * @volumes: volumes of this UBI device
 258  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
 259  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
 260  *                @vol->readers, @vol->writers, @vol->exclusive,
 261  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
 262  * @ref_count: count of references on the UBI device
 263  *
 264  * @rsvd_pebs: count of reserved physical eraseblocks
 265  * @avail_pebs: count of available physical eraseblocks
 266  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
 267  *                 handling
 268  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
 269  *
 270  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
 271  *                     of UBI ititializetion
 272  * @vtbl_slots: how many slots are available in the volume table
 273  * @vtbl_size: size of the volume table in bytes
 274  * @vtbl: in-RAM volume table copy
 275  * @volumes_mutex: protects on-flash volume table and serializes volume
 276  *                 changes, like creation, deletion, update, resize
 277  *
 278  * @max_ec: current highest erase counter value
 279  * @mean_ec: current mean erase counter value
 280  *
 281  * @global_sqnum: global sequence number
 282  * @ltree_lock: protects the lock tree and @global_sqnum
 283  * @ltree: the lock tree
 284  * @alc_mutex: serializes "atomic LEB change" operations
 285  *
 286  * @used: RB-tree of used physical eraseblocks
 287  * @free: RB-tree of free physical eraseblocks
 288  * @scrub: RB-tree of physical eraseblocks which need scrubbing
 289  * @prot: protection trees
 290  * @prot.pnum: protection tree indexed by physical eraseblock numbers
 291  * @prot.aec: protection tree indexed by absolute erase counter value
 292  * @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from,
 293  *           @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works
 294  *           fields
 295  * @move_mutex: serializes eraseblock moves
 296  * @wl_scheduled: non-zero if the wear-leveling was scheduled
 297  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
 298  *             physical eraseblock
 299  * @abs_ec: absolute erase counter
 300  * @move_from: physical eraseblock from where the data is being moved
 301  * @move_to: physical eraseblock where the data is being moved to
 302  * @move_to_put: if the "to" PEB was put
 303  * @works: list of pending works
 304  * @works_count: count of pending works
 305  * @bgt_thread: background thread description object
 306  * @thread_enabled: if the background thread is enabled
 307  * @bgt_name: background thread name
 308  *
 309  * @flash_size: underlying MTD device size (in bytes)
 310  * @peb_count: count of physical eraseblocks on the MTD device
 311  * @peb_size: physical eraseblock size
 312  * @bad_peb_count: count of bad physical eraseblocks
 313  * @good_peb_count: count of good physical eraseblocks
 314  * @min_io_size: minimal input/output unit size of the underlying MTD device
 315  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
 316  * @ro_mode: if the UBI device is in read-only mode
 317  * @leb_size: logical eraseblock size
 318  * @leb_start: starting offset of logical eraseblocks within physical
 319  * eraseblocks
 320  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
 321  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
 322  * @vid_hdr_offset: starting offset of the volume identifier header (might be
 323  * unaligned)
 324  * @vid_hdr_aloffset: starting offset of the VID header aligned to
 325  * @hdrs_min_io_size
 326  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
 327  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
 328  *               not
 329  * @mtd: MTD device descriptor
 330  *
 331  * @peb_buf1: a buffer of PEB size used for different purposes
 332  * @peb_buf2: another buffer of PEB size used for different purposes
 333  * @buf_mutex: proptects @peb_buf1 and @peb_buf2
 334  * @dbg_peb_buf: buffer of PEB size used for debugging
 335  * @dbg_buf_mutex: proptects @dbg_peb_buf
 336  */
 337 struct ubi_device {
 338         struct cdev cdev;
 339         struct device dev;
 340         int ubi_num;
 341         char ubi_name[sizeof(UBI_NAME_STR)+5];
 342         int vol_count;
 343         struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
 344         spinlock_t volumes_lock;
 345         int ref_count;
 346
 347         int rsvd_pebs;
 348         int avail_pebs;
 349         int beb_rsvd_pebs;
 350         int beb_rsvd_level;
 351
 352         int autoresize_vol_id;
 353         int vtbl_slots;
 354         int vtbl_size;
 355         struct ubi_vtbl_record *vtbl;
 356         struct mutex volumes_mutex;
 357
 358         int max_ec;
 359         /* TODO: mean_ec is not updated run-time, fix */
 360         int mean_ec;
 361
 362         /* EBA unit's stuff */
 363         unsigned long long global_sqnum;
 364         spinlock_t ltree_lock;
 365         struct rb_root ltree;
 366         struct mutex alc_mutex;
 367
 368         /* Wear-leveling unit's stuff */
 369         struct rb_root used;
 370         struct rb_root free;
 371         struct rb_root scrub;
 372         struct {
 373                 struct rb_root pnum;
 374                 struct rb_root aec;
 375         } prot;
 376         spinlock_t wl_lock;
 377         struct mutex move_mutex;
 378         struct rw_semaphore work_sem;
 379         int wl_scheduled;
 380         struct ubi_wl_entry **lookuptbl;
 381         unsigned long long abs_ec;
 382         struct ubi_wl_entry *move_from;
 383         struct ubi_wl_entry *move_to;
 384         int move_to_put;
 385         struct list_head works;
 386         int works_count;
 387         struct task_struct *bgt_thread;
 388         int thread_enabled;
 389         char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
 390
 391         /* I/O unit's stuff */
 392         long long flash_size;
 393         int peb_count;
 394         int peb_size;
 395         int bad_peb_count;
 396         int good_peb_count;
 397         int min_io_size;
 398         int hdrs_min_io_size;
 399         int ro_mode;
 400         int leb_size;
 401         int leb_start;
 402         int ec_hdr_alsize;
 403         int vid_hdr_alsize;
 404         int vid_hdr_offset;
 405         int vid_hdr_aloffset;
 406         int vid_hdr_shift;
 407         int bad_allowed;
 408         struct mtd_info *mtd;
 409
 410         void *peb_buf1;
 411         void *peb_buf2;
 412         struct mutex buf_mutex;
 413         struct mutex ckvol_mutex;
 414 #ifdef CONFIG_MTD_UBI_DEBUG
 415         void *dbg_peb_buf;
 416         struct mutex dbg_buf_mutex;
 417 #endif
 418 };
 419
 420 extern struct kmem_cache *ubi_wl_entry_slab;
 421 extern struct file_operations ubi_ctrl_cdev_operations;
 422 extern struct file_operations ubi_cdev_operations;
 423 extern struct file_operations ubi_vol_cdev_operations;
 424 extern struct class *ubi_class;
 425 extern struct mutex ubi_devices_mutex;
 426
 427 /* vtbl.c */
 428 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 429                            struct ubi_vtbl_record *vtbl_rec);
 430 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
 431
 432 /* vmt.c */
 433 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
 434 int ubi_remove_volume(struct ubi_volume_desc *desc);
 435 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
 436 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 437 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
 438
 439 /* upd.c */
 440 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
 441                      long long bytes);
 442 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
 443                          const void __user *buf, int count);
 444 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 445                          const struct ubi_leb_change_req *req);
 446 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
 447                              const void __user *buf, int count);
 448
 449 /* misc.c */
 450 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length);
 451 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 452 void ubi_calculate_reserved(struct ubi_device *ubi);
 453
 454 /* gluebi.c */
 455 #ifdef CONFIG_MTD_UBI_GLUEBI
 456 int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol);
 457 int ubi_destroy_gluebi(struct ubi_volume *vol);
 458 void ubi_gluebi_updated(struct ubi_volume *vol);
 459 #else
 460 #define ubi_create_gluebi(ubi, vol) 0
 461 #define ubi_destroy_gluebi(vol) 0
 462 #define ubi_gluebi_updated(vol)
 463 #endif
 464
 465 /* eba.c */
 466 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
 467                       int lnum);
 468 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 469                      void *buf, int offset, int len, int check);
 470 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
 471                       const void *buf, int offset, int len, int dtype);
 472 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
 473                          int lnum, const void *buf, int len, int dtype,
 474                          int used_ebs);
 475 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
 476                               int lnum, const void *buf, int len, int dtype);
 477 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 478                      struct ubi_vid_hdr *vid_hdr);
 479 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 480 void ubi_eba_close(const struct ubi_device *ubi);
 481
 482 /* wl.c */
 483 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
 484 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
 485 int ubi_wl_flush(struct ubi_device *ubi);
 486 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
 487 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 488 void ubi_wl_close(struct ubi_device *ubi);
 489 int ubi_thread(void *u);
 490
 491 /* io.c */
 492 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
 493                 int len);
 494 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
 495                  int len);
 496 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
 497 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
 498 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
 499 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 500                        struct ubi_ec_hdr *ec_hdr, int verbose);
 501 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
 502                         struct ubi_ec_hdr *ec_hdr);
 503 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 504                         struct ubi_vid_hdr *vid_hdr, int verbose);
 505 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
 506                          struct ubi_vid_hdr *vid_hdr);
 507
 508 /* build.c */
 509 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
 510 int ubi_detach_mtd_dev(int ubi_num, int anyway);
 511 struct ubi_device *ubi_get_device(int ubi_num);
 512 void ubi_put_device(struct ubi_device *ubi);
 513 struct ubi_device *ubi_get_by_major(int major);
 514 int ubi_major2num(int major);
 515
 516 /*
 517  * ubi_rb_for_each_entry - walk an RB-tree.
 518  * @rb: a pointer to type 'struct rb_node' to to use as a loop counter
 519  * @pos: a pointer to RB-tree entry type to use as a loop counter
 520  * @root: RB-tree's root
 521  * @member: the name of the 'struct rb_node' within the RB-tree entry
 522  */
 523 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
 524         for (rb = rb_first(root),                                            \
 525              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
 526              rb;                                                             \
 527              rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member))
 528
 529 /**
 530  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
 531  * @ubi: UBI device description object
 532  * @gfp_flags: GFP flags to allocate with
 533  *
 534  * This function returns a pointer to the newly allocated and zero-filled
 535  * volume identifier header object in case of success and %NULL in case of
 536  * failure.
 537  */
 538 static inline struct ubi_vid_hdr *
 539 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
 540 {
 541         void *vid_hdr;
 542
 543         vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
 544         if (!vid_hdr)
 545                 return NULL;
 546
 547         /*
 548          * VID headers may be stored at un-aligned flash offsets, so we shift
 549          * the pointer.
 550          */
 551         return vid_hdr + ubi->vid_hdr_shift;
 552 }
 553
 554 /**
 555  * ubi_free_vid_hdr - free a volume identifier header object.
 556  * @ubi: UBI device description object
 557  * @vid_hdr: the object to free
 558  */
 559 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
 560                                     struct ubi_vid_hdr *vid_hdr)
 561 {
 562         void *p = vid_hdr;
 563
 564         if (!p)
 565                 return;
 566
 567         kfree(p - ubi->vid_hdr_shift);
 568 }
 569
 570 /*
 571  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
 572  * the beginning of the logical eraseblock, not to the beginning of the
 573  * physical eraseblock.
 574  */
 575 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
 576                                    int pnum, int offset, int len)
 577 {
 578         ubi_assert(offset >= 0);
 579         return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
 580 }
 581
 582 /*
 583  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
 584  * the beginning of the logical eraseblock, not to the beginning of the
 585  * physical eraseblock.
 586  */
 587 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
 588                                     int pnum, int offset, int len)
 589 {
 590         ubi_assert(offset >= 0);
 591         return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
 592 }
 593
 594 /**
 595  * ubi_ro_mode - switch to read-only mode.
 596  * @ubi: UBI device description object
 597  */
 598 static inline void ubi_ro_mode(struct ubi_device *ubi)
 599 {
 600         if (!ubi->ro_mode) {
 601                 ubi->ro_mode = 1;
 602                 ubi_warn("switch to read-only mode");
 603         }
 604 }
 605
 606 /**
 607  * vol_id2idx - get table index by volume ID.
 608  * @ubi: UBI device description object
 609  * @vol_id: volume ID
 610  */
 611 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
 612 {
 613         if (vol_id >= UBI_INTERNAL_VOL_START)
 614                 return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
 615         else
 616                 return vol_id;
 617 }
 618
 619 /**
 620  * idx2vol_id - get volume ID by table index.
 621  * @ubi: UBI device description object
 622  * @idx: table index
 623  */
 624 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
 625 {
 626         if (idx >= ubi->vtbl_slots)
 627                 return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
 628         else
 629                 return idx;
 630 }
 631
 632 #endif /* !__UBI_UBI_H__ */