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/mtd/mtd.h>
  39
  40 #include <mtd/ubi-header.h>
  41 #include <linux/mtd/ubi.h>
  42
  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                                   __FUNCTION__, ##__VA_ARGS__)
  57 /* UBI error messages */
  58 #define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \
  59                                  __FUNCTION__, ##__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 extern int ubi_devices_cnt;
  97 extern struct ubi_device *ubi_devices[];
  98
  99 struct ubi_volume_desc;
 100
 101 /**
 102  * struct ubi_volume - UBI volume description data structure.
 103  * @dev: device object to make use of the the Linux device model
 104  * @cdev: character device object to create character device
 105  * @ubi: reference to the UBI device description object
 106  * @vol_id: volume ID
 107  * @readers: number of users holding this volume in read-only mode
 108  * @writers: number of users holding this volume in read-write mode
 109  * @exclusive: whether somebody holds this volume in exclusive mode
 110  * @removed: if the volume was removed
 111  * @checked: if this static volume was checked
 112  *
 113  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
 114  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
 115  * @usable_leb_size: logical eraseblock size without padding
 116  * @used_ebs: how many logical eraseblocks in this volume contain data
 117  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
 118  * @used_bytes: how many bytes of data this volume contains
 119  * @upd_marker: non-zero if the update marker is set for this volume
 120  * @corrupted: non-zero if the volume is corrupted (static volumes only)
 121  * @alignment: volume alignment
 122  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
 123  * satisfy the requested alignment
 124  * @name_len: volume name length
 125  * @name: volume name
 126  *
 127  * @updating: whether the volume is being updated
 128  * @upd_ebs: how many eraseblocks are expected to be updated
 129  * @upd_bytes: how many bytes are expected to be received
 130  * @upd_received: how many update bytes were already received
 131  * @upd_buf: update buffer which is used to collect update data
 132  *
 133  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
 134  *
 135  * @gluebi_desc: gluebi UBI volume descriptor
 136  * @gluebi_refcount: reference count of the gluebi MTD device
 137  * @gluebi_mtd: MTD device description object of the gluebi MTD device
 138  *
 139  * The @corrupted field indicates that the volume's contents is corrupted.
 140  * Since UBI protects only static volumes, this field is not relevant to
 141  * dynamic volumes - it is user's responsibility to assure their data
 142  * integrity.
 143  *
 144  * The @upd_marker flag indicates that this volume is either being updated at
 145  * the moment or is damaged because of an unclean reboot.
 146  */
 147 struct ubi_volume {
 148         struct device dev;
 149         struct cdev cdev;
 150         struct ubi_device *ubi;
 151         int vol_id;
 152         int readers;
 153         int writers;
 154         int exclusive;
 155         int removed;
 156         int checked;
 157
 158         int reserved_pebs;
 159         int vol_type;
 160         int usable_leb_size;
 161         int used_ebs;
 162         int last_eb_bytes;
 163         long long used_bytes;
 164         int upd_marker;
 165         int corrupted;
 166         int alignment;
 167         int data_pad;
 168         int name_len;
 169         char name[UBI_VOL_NAME_MAX+1];
 170
 171         int updating;
 172         int upd_ebs;
 173         long long upd_bytes;
 174         long long upd_received;
 175         void *upd_buf;
 176
 177         int *eba_tbl;
 178
 179 #ifdef CONFIG_MTD_UBI_GLUEBI
 180         /* Gluebi-related stuff may be compiled out */
 181         struct ubi_volume_desc *gluebi_desc;
 182         int gluebi_refcount;
 183         struct mtd_info gluebi_mtd;
 184 #endif
 185 };
 186
 187 /**
 188  * struct ubi_volume_desc - descriptor of the UBI volume returned when it is
 189  * opened.
 190  * @vol: reference to the corresponding volume description object
 191  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
 192  */
 193 struct ubi_volume_desc {
 194         struct ubi_volume *vol;
 195         int mode;
 196 };
 197
 198 struct ubi_wl_entry;
 199
 200 /**
 201  * struct ubi_device - UBI device description structure
 202  * @dev: class device object to use the the Linux device model
 203  * @cdev: character device object to create character device
 204  * @ubi_num: UBI device number
 205  * @ubi_name: UBI device name
 206  * @major: character device major number
 207  * @vol_count: number of volumes in this UBI device
 208  * @volumes: volumes of this UBI device
 209  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
 210  * @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count, @vol->readers,
 211  * @vol->writers, @vol->exclusive, @vol->removed, @vol->mapping and
 212  * @vol->eba_tbl.
 213  *
 214  * @rsvd_pebs: count of reserved physical eraseblocks
 215  * @avail_pebs: count of available physical eraseblocks
 216  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
 217  * handling
 218  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
 219  *
 220  * @vtbl_slots: how many slots are available in the volume table
 221  * @vtbl_size: size of the volume table in bytes
 222  * @vtbl: in-RAM volume table copy
 223  *
 224  * @max_ec: current highest erase counter value
 225  * @mean_ec: current mean erase counter value
 226  *
 227  * global_sqnum: global sequence number
 228  * @ltree_lock: protects the lock tree and @global_sqnum
 229  * @ltree: the lock tree
 230  * @vtbl_mutex: protects on-flash volume table
 231  *
 232  * @used: RB-tree of used physical eraseblocks
 233  * @free: RB-tree of free physical eraseblocks
 234  * @scrub: RB-tree of physical eraseblocks which need scrubbing
 235  * @prot: protection trees
 236  * @prot.pnum: protection tree indexed by physical eraseblock numbers
 237  * @prot.aec: protection tree indexed by absolute erase counter value
 238  * @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from,
 239  * @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works
 240  * fields
 241  * @wl_scheduled: non-zero if the wear-leveling was scheduled
 242  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
 243  * physical eraseblock
 244  * @abs_ec: absolute erase counter
 245  * @move_from: physical eraseblock from where the data is being moved
 246  * @move_to: physical eraseblock where the data is being moved to
 247  * @move_from_put: if the "from" PEB was put
 248  * @move_to_put: if the "to" PEB was put
 249  * @works: list of pending works
 250  * @works_count: count of pending works
 251  * @bgt_thread: background thread description object
 252  * @thread_enabled: if the background thread is enabled
 253  * @bgt_name: background thread name
 254  *
 255  * @flash_size: underlying MTD device size (in bytes)
 256  * @peb_count: count of physical eraseblocks on the MTD device
 257  * @peb_size: physical eraseblock size
 258  * @bad_peb_count: count of bad physical eraseblocks
 259  * @good_peb_count: count of good physical eraseblocks
 260  * @min_io_size: minimal input/output unit size of the underlying MTD device
 261  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
 262  * @ro_mode: if the UBI device is in read-only mode
 263  * @leb_size: logical eraseblock size
 264  * @leb_start: starting offset of logical eraseblocks within physical
 265  * eraseblocks
 266  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
 267  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
 268  * @vid_hdr_offset: starting offset of the volume identifier header (might be
 269  * unaligned)
 270  * @vid_hdr_aloffset: starting offset of the VID header aligned to
 271  * @hdrs_min_io_size
 272  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
 273  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
 274  * not
 275  * @mtd: MTD device descriptor
 276  */
 277 struct ubi_device {
 278         struct cdev cdev;
 279         struct device dev;
 280         int ubi_num;
 281         char ubi_name[sizeof(UBI_NAME_STR)+5];
 282         int major;
 283         int vol_count;
 284         struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
 285         spinlock_t volumes_lock;
 286
 287         int rsvd_pebs;
 288         int avail_pebs;
 289         int beb_rsvd_pebs;
 290         int beb_rsvd_level;
 291
 292         int vtbl_slots;
 293         int vtbl_size;
 294         struct ubi_vtbl_record *vtbl;
 295         struct mutex vtbl_mutex;
 296
 297         int max_ec;
 298         int mean_ec;
 299
 300         /* EBA unit's stuff */
 301         unsigned long long global_sqnum;
 302         spinlock_t ltree_lock;
 303         struct rb_root ltree;
 304
 305         /* Wear-leveling unit's stuff */
 306         struct rb_root used;
 307         struct rb_root free;
 308         struct rb_root scrub;
 309         struct {
 310                 struct rb_root pnum;
 311                 struct rb_root aec;
 312         } prot;
 313         spinlock_t wl_lock;
 314         int wl_scheduled;
 315         struct ubi_wl_entry **lookuptbl;
 316         unsigned long long abs_ec;
 317         struct ubi_wl_entry *move_from;
 318         struct ubi_wl_entry *move_to;
 319         int move_from_put;
 320         int move_to_put;
 321         struct list_head works;
 322         int works_count;
 323         struct task_struct *bgt_thread;
 324         int thread_enabled;
 325         char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
 326
 327         /* I/O unit's stuff */
 328         long long flash_size;
 329         int peb_count;
 330         int peb_size;
 331         int bad_peb_count;
 332         int good_peb_count;
 333         int min_io_size;
 334         int hdrs_min_io_size;
 335         int ro_mode;
 336         int leb_size;
 337         int leb_start;
 338         int ec_hdr_alsize;
 339         int vid_hdr_alsize;
 340         int vid_hdr_offset;
 341         int vid_hdr_aloffset;
 342         int vid_hdr_shift;
 343         int bad_allowed;
 344         struct mtd_info *mtd;
 345 };
 346
 347 extern struct file_operations ubi_cdev_operations;
 348 extern struct file_operations ubi_vol_cdev_operations;
 349 extern struct class *ubi_class;
 350
 351 /* vtbl.c */
 352 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 353                            struct ubi_vtbl_record *vtbl_rec);
 354 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
 355
 356 /* vmt.c */
 357 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
 358 int ubi_remove_volume(struct ubi_volume_desc *desc);
 359 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
 360 int ubi_add_volume(struct ubi_device *ubi, int vol_id);
 361 void ubi_free_volume(struct ubi_device *ubi, int vol_id);
 362
 363 /* upd.c */
 364 int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes);
 365 int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
 366                          const void __user *buf, int count);
 367
 368 /* misc.c */
 369 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length);
 370 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 371 void ubi_calculate_reserved(struct ubi_device *ubi);
 372
 373 /* gluebi.c */
 374 #ifdef CONFIG_MTD_UBI_GLUEBI
 375 int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol);
 376 int ubi_destroy_gluebi(struct ubi_volume *vol);
 377 #else
 378 #define ubi_create_gluebi(ubi, vol) 0
 379 #define ubi_destroy_gluebi(vol) 0
 380 #endif
 381
 382 /* eba.c */
 383 int ubi_eba_unmap_leb(struct ubi_device *ubi, int vol_id, int lnum);
 384 int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
 385                      int offset, int len, int check);
 386 int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum,
 387                       const void *buf, int offset, int len, int dtype);
 388 int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum,
 389                          const void *buf, int len, int dtype,
 390                          int used_ebs);
 391 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
 392                               const void *buf, int len, int dtype);
 393 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 394                      struct ubi_vid_hdr *vid_hdr);
 395 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 396 void ubi_eba_close(const struct ubi_device *ubi);
 397
 398 /* wl.c */
 399 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
 400 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
 401 int ubi_wl_flush(struct ubi_device *ubi);
 402 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
 403 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 404 void ubi_wl_close(struct ubi_device *ubi);
 405
 406 /* io.c */
 407 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
 408                 int len);
 409 int ubi_io_write(const struct ubi_device *ubi, const void *buf, int pnum,
 410                  int offset, int len);
 411 int ubi_io_sync_erase(const struct ubi_device *ubi, int pnum, int torture);
 412 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
 413 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
 414 int ubi_io_read_ec_hdr(const struct ubi_device *ubi, int pnum,
 415                        struct ubi_ec_hdr *ec_hdr, int verbose);
 416 int ubi_io_write_ec_hdr(const struct ubi_device *ubi, int pnum,
 417                         struct ubi_ec_hdr *ec_hdr);
 418 int ubi_io_read_vid_hdr(const struct ubi_device *ubi, int pnum,
 419                         struct ubi_vid_hdr *vid_hdr, int verbose);
 420 int ubi_io_write_vid_hdr(const struct ubi_device *ubi, int pnum,
 421                          struct ubi_vid_hdr *vid_hdr);
 422
 423 /*
 424  * ubi_rb_for_each_entry - walk an RB-tree.
 425  * @rb: a pointer to type 'struct rb_node' to to use as a loop counter
 426  * @pos: a pointer to RB-tree entry type to use as a loop counter
 427  * @root: RB-tree's root
 428  * @member: the name of the 'struct rb_node' within the RB-tree entry
 429  */
 430 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
 431         for (rb = rb_first(root),                                            \
 432              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
 433              rb;                                                             \
 434              rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member))
 435
 436 /**
 437  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
 438  * @ubi: UBI device description object
 439  *
 440  * This function returns a pointer to the newly allocated and zero-filled
 441  * volume identifier header object in case of success and %NULL in case of
 442  * failure.
 443  */
 444 static inline struct ubi_vid_hdr *ubi_zalloc_vid_hdr(const struct ubi_device *ubi)
 445 {
 446         void *vid_hdr;
 447
 448         vid_hdr = kzalloc(ubi->vid_hdr_alsize, GFP_KERNEL);
 449         if (!vid_hdr)
 450                 return NULL;
 451
 452         /*
 453          * VID headers may be stored at un-aligned flash offsets, so we shift
 454          * the pointer.
 455          */
 456         return vid_hdr + ubi->vid_hdr_shift;
 457 }
 458
 459 /**
 460  * ubi_free_vid_hdr - free a volume identifier header object.
 461  * @ubi: UBI device description object
 462  * @vid_hdr: the object to free
 463  */
 464 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
 465                                     struct ubi_vid_hdr *vid_hdr)
 466 {
 467         void *p = vid_hdr;
 468
 469         if (!p)
 470                 return;
 471
 472         kfree(p - ubi->vid_hdr_shift);
 473 }
 474
 475 /*
 476  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
 477  * the beginning of the logical eraseblock, not to the beginning of the
 478  * physical eraseblock.
 479  */
 480 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
 481                                    int pnum, int offset, int len)
 482 {
 483         ubi_assert(offset >= 0);
 484         return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
 485 }
 486
 487 /*
 488  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
 489  * the beginning of the logical eraseblock, not to the beginning of the
 490  * physical eraseblock.
 491  */
 492 static inline int ubi_io_write_data(const struct ubi_device *ubi, const void *buf,
 493                                     int pnum, int offset, int len)
 494 {
 495         ubi_assert(offset >= 0);
 496         return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
 497 }
 498
 499 /**
 500  * ubi_ro_mode - switch to read-only mode.
 501  * @ubi: UBI device description object
 502  */
 503 static inline void ubi_ro_mode(struct ubi_device *ubi)
 504 {
 505         ubi->ro_mode = 1;
 506         ubi_warn("switch to read-only mode");
 507 }
 508
 509 /**
 510  * vol_id2idx - get table index by volume ID.
 511  * @ubi: UBI device description object
 512  * @vol_id: volume ID
 513  */
 514 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
 515 {
 516         if (vol_id >= UBI_INTERNAL_VOL_START)
 517                 return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
 518         else
 519                 return vol_id;
 520 }
 521
 522 /**
 523  * idx2vol_id - get volume ID by table index.
 524  * @ubi: UBI device description object
 525  * @idx: table index
 526  */
 527 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
 528 {
 529         if (idx >= ubi->vtbl_slots)
 530                 return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
 531         else
 532                 return idx;
 533 }
 534
 535 #endif /* !__UBI_UBI_H__ */