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 extern int ubi_devices_cnt;
  98 extern struct ubi_device *ubi_devices[];
  99
 100 struct ubi_volume_desc;
 101
 102 /**
 103  * struct ubi_volume - UBI volume description data structure.
 104  * @dev: device object to make use of the the Linux device model
 105  * @cdev: character device object to create character device
 106  * @ubi: reference to the UBI device description object
 107  * @vol_id: volume ID
 108  * @readers: number of users holding this volume in read-only mode
 109  * @writers: number of users holding this volume in read-write mode
 110  * @exclusive: whether somebody holds this volume in exclusive mode
 111  * @removed: if the volume was removed
 112  * @checked: if this static volume was checked
 113  *
 114  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
 115  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
 116  * @usable_leb_size: logical eraseblock size without padding
 117  * @used_ebs: how many logical eraseblocks in this volume contain data
 118  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
 119  * @used_bytes: how many bytes of data this volume contains
 120  * @upd_marker: non-zero if the update marker is set for this volume
 121  * @corrupted: non-zero if the volume is corrupted (static volumes only)
 122  * @alignment: volume alignment
 123  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
 124  * satisfy the requested alignment
 125  * @name_len: volume name length
 126  * @name: volume name
 127  *
 128  * @updating: whether the volume is being updated
 129  * @upd_ebs: how many eraseblocks are expected to be updated
 130  * @upd_bytes: how many bytes are expected to be received
 131  * @upd_received: how many update bytes were already received
 132  * @upd_buf: update buffer which is used to collect update data
 133  *
 134  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
 135  *
 136  * @gluebi_desc: gluebi UBI volume descriptor
 137  * @gluebi_refcount: reference count of the gluebi MTD device
 138  * @gluebi_mtd: MTD device description object of the gluebi MTD device
 139  *
 140  * The @corrupted field indicates that the volume's contents is corrupted.
 141  * Since UBI protects only static volumes, this field is not relevant to
 142  * dynamic volumes - it is user's responsibility to assure their data
 143  * integrity.
 144  *
 145  * The @upd_marker flag indicates that this volume is either being updated at
 146  * the moment or is damaged because of an unclean reboot.
 147  */
 148 struct ubi_volume {
 149         struct device dev;
 150         struct cdev cdev;
 151         struct ubi_device *ubi;
 152         int vol_id;
 153         int readers;
 154         int writers;
 155         int exclusive;
 156         int removed;
 157         int checked;
 158
 159         int reserved_pebs;
 160         int vol_type;
 161         int usable_leb_size;
 162         int used_ebs;
 163         int last_eb_bytes;
 164         long long used_bytes;
 165         int upd_marker;
 166         int corrupted;
 167         int alignment;
 168         int data_pad;
 169         int name_len;
 170         char name[UBI_VOL_NAME_MAX+1];
 171
 172         int updating;
 173         int upd_ebs;
 174         long long upd_bytes;
 175         long long upd_received;
 176         void *upd_buf;
 177
 178         int *eba_tbl;
 179
 180 #ifdef CONFIG_MTD_UBI_GLUEBI
 181         /* Gluebi-related stuff may be compiled out */
 182         struct ubi_volume_desc *gluebi_desc;
 183         int gluebi_refcount;
 184         struct mtd_info gluebi_mtd;
 185 #endif
 186 };
 187
 188 /**
 189  * struct ubi_volume_desc - descriptor of the UBI volume returned when it is
 190  * opened.
 191  * @vol: reference to the corresponding volume description object
 192  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
 193  */
 194 struct ubi_volume_desc {
 195         struct ubi_volume *vol;
 196         int mode;
 197 };
 198
 199 struct ubi_wl_entry;
 200
 201 /**
 202  * struct ubi_device - UBI device description structure
 203  * @dev: class device object to use the the Linux device model
 204  * @cdev: character device object to create character device
 205  * @ubi_num: UBI device number
 206  * @ubi_name: UBI device name
 207  * @major: character device major number
 208  * @vol_count: number of volumes in this UBI device
 209  * @volumes: volumes of this UBI device
 210  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
 211  * @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count, @vol->readers,
 212  * @vol->writers, @vol->exclusive, @vol->removed, @vol->mapping and
 213  * @vol->eba_tbl.
 214  *
 215  * @rsvd_pebs: count of reserved physical eraseblocks
 216  * @avail_pebs: count of available physical eraseblocks
 217  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
 218  * handling
 219  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
 220  *
 221  * @vtbl_slots: how many slots are available in the volume table
 222  * @vtbl_size: size of the volume table in bytes
 223  * @vtbl: in-RAM volume table copy
 224  * @vtbl_mutex: protects on-flash volume table
 225  *
 226  * @max_ec: current highest erase counter value
 227  * @mean_ec: current mean erase counter value
 228  *
 229  * @global_sqnum: global sequence number
 230  * @ltree_lock: protects the lock tree and @global_sqnum
 231  * @ltree: the lock tree
 232  * @alc_mutex: serializes "atomic LEB change" operations
 233  *
 234  * @used: RB-tree of used physical eraseblocks
 235  * @free: RB-tree of free physical eraseblocks
 236  * @scrub: RB-tree of physical eraseblocks which need scrubbing
 237  * @prot: protection trees
 238  * @prot.pnum: protection tree indexed by physical eraseblock numbers
 239  * @prot.aec: protection tree indexed by absolute erase counter value
 240  * @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from,
 241  * @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works
 242  * fields
 243  * @wl_scheduled: non-zero if the wear-leveling was scheduled
 244  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
 245  * physical eraseblock
 246  * @abs_ec: absolute erase counter
 247  * @move_from: physical eraseblock from where the data is being moved
 248  * @move_to: physical eraseblock where the data is being moved to
 249  * @move_from_put: if the "from" PEB was put
 250  * @move_to_put: if the "to" PEB was put
 251  * @works: list of pending works
 252  * @works_count: count of pending works
 253  * @bgt_thread: background thread description object
 254  * @thread_enabled: if the background thread is enabled
 255  * @bgt_name: background thread name
 256  *
 257  * @flash_size: underlying MTD device size (in bytes)
 258  * @peb_count: count of physical eraseblocks on the MTD device
 259  * @peb_size: physical eraseblock size
 260  * @bad_peb_count: count of bad physical eraseblocks
 261  * @good_peb_count: count of good physical eraseblocks
 262  * @min_io_size: minimal input/output unit size of the underlying MTD device
 263  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
 264  * @ro_mode: if the UBI device is in read-only mode
 265  * @leb_size: logical eraseblock size
 266  * @leb_start: starting offset of logical eraseblocks within physical
 267  * eraseblocks
 268  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
 269  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
 270  * @vid_hdr_offset: starting offset of the volume identifier header (might be
 271  * unaligned)
 272  * @vid_hdr_aloffset: starting offset of the VID header aligned to
 273  * @hdrs_min_io_size
 274  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
 275  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
 276  * not
 277  * @mtd: MTD device descriptor
 278  *
 279  * @peb_buf1: a buffer of PEB size used for different purposes
 280  * @peb_buf2: another buffer of PEB size used for different purposes
 281  * @buf_mutex: proptects @peb_buf1 and @peb_buf2
 282  * @dbg_peb_buf:  buffer of PEB size used for debugging
 283  * @dbg_buf_mutex: proptects @dbg_peb_buf
 284  */
 285 struct ubi_device {
 286         struct cdev cdev;
 287         struct device dev;
 288         int ubi_num;
 289         char ubi_name[sizeof(UBI_NAME_STR)+5];
 290         int major;
 291         int vol_count;
 292         struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
 293         spinlock_t volumes_lock;
 294
 295         int rsvd_pebs;
 296         int avail_pebs;
 297         int beb_rsvd_pebs;
 298         int beb_rsvd_level;
 299
 300         int vtbl_slots;
 301         int vtbl_size;
 302         struct ubi_vtbl_record *vtbl;
 303         struct mutex vtbl_mutex;
 304
 305         int max_ec;
 306         int mean_ec;
 307
 308         /* EBA unit's stuff */
 309         unsigned long long global_sqnum;
 310         spinlock_t ltree_lock;
 311         struct rb_root ltree;
 312         struct mutex alc_mutex;
 313
 314         /* Wear-leveling unit's stuff */
 315         struct rb_root used;
 316         struct rb_root free;
 317         struct rb_root scrub;
 318         struct {
 319                 struct rb_root pnum;
 320                 struct rb_root aec;
 321         } prot;
 322         spinlock_t wl_lock;
 323         int wl_scheduled;
 324         struct ubi_wl_entry **lookuptbl;
 325         unsigned long long abs_ec;
 326         struct ubi_wl_entry *move_from;
 327         struct ubi_wl_entry *move_to;
 328         int move_from_put;
 329         int move_to_put;
 330         struct list_head works;
 331         int works_count;
 332         struct task_struct *bgt_thread;
 333         int thread_enabled;
 334         char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
 335
 336         /* I/O unit's stuff */
 337         long long flash_size;
 338         int peb_count;
 339         int peb_size;
 340         int bad_peb_count;
 341         int good_peb_count;
 342         int min_io_size;
 343         int hdrs_min_io_size;
 344         int ro_mode;
 345         int leb_size;
 346         int leb_start;
 347         int ec_hdr_alsize;
 348         int vid_hdr_alsize;
 349         int vid_hdr_offset;
 350         int vid_hdr_aloffset;
 351         int vid_hdr_shift;
 352         int bad_allowed;
 353         struct mtd_info *mtd;
 354
 355         void *peb_buf1;
 356         void *peb_buf2;
 357         struct mutex buf_mutex;
 358 #ifdef CONFIG_MTD_UBI_DEBUG
 359         void *dbg_peb_buf;
 360         struct mutex dbg_buf_mutex;
 361 #endif
 362 };
 363
 364 extern struct file_operations ubi_cdev_operations;
 365 extern struct file_operations ubi_vol_cdev_operations;
 366 extern struct class *ubi_class;
 367
 368 /* vtbl.c */
 369 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
 370                            struct ubi_vtbl_record *vtbl_rec);
 371 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
 372
 373 /* vmt.c */
 374 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
 375 int ubi_remove_volume(struct ubi_volume_desc *desc);
 376 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
 377 int ubi_add_volume(struct ubi_device *ubi, int vol_id);
 378 void ubi_free_volume(struct ubi_device *ubi, int vol_id);
 379
 380 /* upd.c */
 381 int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes);
 382 int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
 383                          const void __user *buf, int count);
 384
 385 /* misc.c */
 386 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length);
 387 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
 388 void ubi_calculate_reserved(struct ubi_device *ubi);
 389
 390 /* gluebi.c */
 391 #ifdef CONFIG_MTD_UBI_GLUEBI
 392 int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol);
 393 int ubi_destroy_gluebi(struct ubi_volume *vol);
 394 void ubi_gluebi_updated(struct ubi_volume *vol);
 395 #else
 396 #define ubi_create_gluebi(ubi, vol) 0
 397 #define ubi_destroy_gluebi(vol) 0
 398 #define ubi_gluebi_updated(vol)
 399 #endif
 400
 401 /* eba.c */
 402 int ubi_eba_unmap_leb(struct ubi_device *ubi, int vol_id, int lnum);
 403 int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
 404                      int offset, int len, int check);
 405 int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum,
 406                       const void *buf, int offset, int len, int dtype);
 407 int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum,
 408                          const void *buf, int len, int dtype,
 409                          int used_ebs);
 410 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
 411                               const void *buf, int len, int dtype);
 412 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
 413                      struct ubi_vid_hdr *vid_hdr);
 414 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 415 void ubi_eba_close(const struct ubi_device *ubi);
 416
 417 /* wl.c */
 418 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
 419 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
 420 int ubi_wl_flush(struct ubi_device *ubi);
 421 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
 422 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
 423 void ubi_wl_close(struct ubi_device *ubi);
 424
 425 /* io.c */
 426 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
 427                 int len);
 428 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
 429                  int len);
 430 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
 431 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
 432 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
 433 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
 434                        struct ubi_ec_hdr *ec_hdr, int verbose);
 435 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
 436                         struct ubi_ec_hdr *ec_hdr);
 437 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
 438                         struct ubi_vid_hdr *vid_hdr, int verbose);
 439 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
 440                          struct ubi_vid_hdr *vid_hdr);
 441
 442 /*
 443  * ubi_rb_for_each_entry - walk an RB-tree.
 444  * @rb: a pointer to type 'struct rb_node' to to use as a loop counter
 445  * @pos: a pointer to RB-tree entry type to use as a loop counter
 446  * @root: RB-tree's root
 447  * @member: the name of the 'struct rb_node' within the RB-tree entry
 448  */
 449 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
 450         for (rb = rb_first(root),                                            \
 451              pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
 452              rb;                                                             \
 453              rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member))
 454
 455 /**
 456  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
 457  * @ubi: UBI device description object
 458  * @gfp_flags: GFP flags to allocate with
 459  *
 460  * This function returns a pointer to the newly allocated and zero-filled
 461  * volume identifier header object in case of success and %NULL in case of
 462  * failure.
 463  */
 464 static inline struct ubi_vid_hdr *
 465 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
 466 {
 467         void *vid_hdr;
 468
 469         vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
 470         if (!vid_hdr)
 471                 return NULL;
 472
 473         /*
 474          * VID headers may be stored at un-aligned flash offsets, so we shift
 475          * the pointer.
 476          */
 477         return vid_hdr + ubi->vid_hdr_shift;
 478 }
 479
 480 /**
 481  * ubi_free_vid_hdr - free a volume identifier header object.
 482  * @ubi: UBI device description object
 483  * @vid_hdr: the object to free
 484  */
 485 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
 486                                     struct ubi_vid_hdr *vid_hdr)
 487 {
 488         void *p = vid_hdr;
 489
 490         if (!p)
 491                 return;
 492
 493         kfree(p - ubi->vid_hdr_shift);
 494 }
 495
 496 /*
 497  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
 498  * the beginning of the logical eraseblock, not to the beginning of the
 499  * physical eraseblock.
 500  */
 501 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
 502                                    int pnum, int offset, int len)
 503 {
 504         ubi_assert(offset >= 0);
 505         return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
 506 }
 507
 508 /*
 509  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
 510  * the beginning of the logical eraseblock, not to the beginning of the
 511  * physical eraseblock.
 512  */
 513 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
 514                                     int pnum, int offset, int len)
 515 {
 516         ubi_assert(offset >= 0);
 517         return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
 518 }
 519
 520 /**
 521  * ubi_ro_mode - switch to read-only mode.
 522  * @ubi: UBI device description object
 523  */
 524 static inline void ubi_ro_mode(struct ubi_device *ubi)
 525 {
 526         ubi->ro_mode = 1;
 527         ubi_warn("switch to read-only mode");
 528 }
 529
 530 /**
 531  * vol_id2idx - get table index by volume ID.
 532  * @ubi: UBI device description object
 533  * @vol_id: volume ID
 534  */
 535 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
 536 {
 537         if (vol_id >= UBI_INTERNAL_VOL_START)
 538                 return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
 539         else
 540                 return vol_id;
 541 }
 542
 543 /**
 544  * idx2vol_id - get volume ID by table index.
 545  * @ubi: UBI device description object
 546  * @idx: table index
 547  */
 548 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
 549 {
 550         if (idx >= ubi->vtbl_slots)
 551                 return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
 552         else
 553                 return idx;
 554 }
 555
 556 #endif /* !__UBI_UBI_H__ */