drivers/mtd/ubi/build.c

   1 /*
   2  * Copyright (c) International Business Machines Corp., 2006
   3  * Copyright (c) Nokia Corporation, 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  *         Frank Haverkamp
  21  */
  22
  23 /*
  24  * This file includes UBI initialization and building of UBI devices.
  25  *
  26  * When UBI is initialized, it attaches all the MTD devices specified as the
  27  * module load parameters or the kernel boot parameters. If MTD devices were
  28  * specified, UBI does not attach any MTD device, but it is possible to do
  29  * later using the "UBI control device".
  30  *
  31  * At the moment we only attach UBI devices by scanning, which will become a
  32  * bottleneck when flashes reach certain large size. Then one may improve UBI
  33  * and add other methods, although it does not seem to be easy to do.
  34  */
  35
  36 #include <linux/err.h>
  37 #include <linux/module.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/stringify.h>
  40 #include <linux/stat.h>
  41 #include <linux/miscdevice.h>
  42 #include <linux/log2.h>
  43 #include <linux/kthread.h>
  44 #include "ubi.h"
  45
  46 /* Maximum length of the 'mtd=' parameter */
  47 #define MTD_PARAM_LEN_MAX 64
  48
  49 /**
  50  * struct mtd_dev_param - MTD device parameter description data structure.
  51  * @name: MTD device name or number string
  52  * @vid_hdr_offs: VID header offset
  53  */
  54 struct mtd_dev_param {
  55         char name[MTD_PARAM_LEN_MAX];
  56         int vid_hdr_offs;
  57 };
  58
  59 /* Numbers of elements set in the @mtd_dev_param array */
  60 static int mtd_devs;
  61
  62 /* MTD devices specification parameters */
  63 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
  64
  65 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
  66 struct class *ubi_class;
  67
  68 /* Slab cache for wear-leveling entries */
  69 struct kmem_cache *ubi_wl_entry_slab;
  70
  71 /* UBI control character device */
  72 static struct miscdevice ubi_ctrl_cdev = {
  73         .minor = MISC_DYNAMIC_MINOR,
  74         .name = "ubi_ctrl",
  75         .fops = &ubi_ctrl_cdev_operations,
  76 };
  77
  78 /* All UBI devices in system */
  79 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
  80
  81 /* Serializes UBI devices creations and removals */
  82 DEFINE_MUTEX(ubi_devices_mutex);
  83
  84 /* Protects @ubi_devices and @ubi->ref_count */
  85 static DEFINE_SPINLOCK(ubi_devices_lock);
  86
  87 /* "Show" method for files in '/<sysfs>/class/ubi/' */
  88 static ssize_t ubi_version_show(struct class *class, char *buf)
  89 {
  90         return sprintf(buf, "%d\n", UBI_VERSION);
  91 }
  92
  93 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
  94 static struct class_attribute ubi_version =
  95         __ATTR(version, S_IRUGO, ubi_version_show, NULL);
  96
  97 static ssize_t dev_attribute_show(struct device *dev,
  98                                   struct device_attribute *attr, char *buf);
  99
 100 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
 101 static struct device_attribute dev_eraseblock_size =
 102         __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
 103 static struct device_attribute dev_avail_eraseblocks =
 104         __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
 105 static struct device_attribute dev_total_eraseblocks =
 106         __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
 107 static struct device_attribute dev_volumes_count =
 108         __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
 109 static struct device_attribute dev_max_ec =
 110         __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
 111 static struct device_attribute dev_reserved_for_bad =
 112         __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
 113 static struct device_attribute dev_bad_peb_count =
 114         __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
 115 static struct device_attribute dev_max_vol_count =
 116         __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
 117 static struct device_attribute dev_min_io_size =
 118         __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
 119 static struct device_attribute dev_bgt_enabled =
 120         __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
 121 static struct device_attribute dev_mtd_num =
 122         __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
 123
 124 /**
 125  * ubi_get_device - get UBI device.
 126  * @ubi_num: UBI device number
 127  *
 128  * This function returns UBI device description object for UBI device number
 129  * @ubi_num, or %NULL if the device does not exist. This function increases the
 130  * device reference count to prevent removal of the device. In other words, the
 131  * device cannot be removed if its reference count is not zero.
 132  */
 133 struct ubi_device *ubi_get_device(int ubi_num)
 134 {
 135         struct ubi_device *ubi;
 136
 137         spin_lock(&ubi_devices_lock);
 138         ubi = ubi_devices[ubi_num];
 139         if (ubi) {
 140                 ubi_assert(ubi->ref_count >= 0);
 141                 ubi->ref_count += 1;
 142                 get_device(&ubi->dev);
 143         }
 144         spin_unlock(&ubi_devices_lock);
 145
 146         return ubi;
 147 }
 148
 149 /**
 150  * ubi_put_device - drop an UBI device reference.
 151  * @ubi: UBI device description object
 152  */
 153 void ubi_put_device(struct ubi_device *ubi)
 154 {
 155         spin_lock(&ubi_devices_lock);
 156         ubi->ref_count -= 1;
 157         put_device(&ubi->dev);
 158         spin_unlock(&ubi_devices_lock);
 159 }
 160
 161 /**
 162  * ubi_get_by_major - get UBI device by character device major number.
 163  * @major: major number
 164  *
 165  * This function is similar to 'ubi_get_device()', but it searches the device
 166  * by its major number.
 167  */
 168 struct ubi_device *ubi_get_by_major(int major)
 169 {
 170         int i;
 171         struct ubi_device *ubi;
 172
 173         spin_lock(&ubi_devices_lock);
 174         for (i = 0; i < UBI_MAX_DEVICES; i++) {
 175                 ubi = ubi_devices[i];
 176                 if (ubi && MAJOR(ubi->cdev.dev) == major) {
 177                         ubi_assert(ubi->ref_count >= 0);
 178                         ubi->ref_count += 1;
 179                         get_device(&ubi->dev);
 180                         spin_unlock(&ubi_devices_lock);
 181                         return ubi;
 182                 }
 183         }
 184         spin_unlock(&ubi_devices_lock);
 185
 186         return NULL;
 187 }
 188
 189 /**
 190  * ubi_major2num - get UBI device number by character device major number.
 191  * @major: major number
 192  *
 193  * This function searches UBI device number object by its major number. If UBI
 194  * device was not found, this function returns -ENODEV, otherwise the UBI device
 195  * number is returned.
 196  */
 197 int ubi_major2num(int major)
 198 {
 199         int i, ubi_num = -ENODEV;
 200
 201         spin_lock(&ubi_devices_lock);
 202         for (i = 0; i < UBI_MAX_DEVICES; i++) {
 203                 struct ubi_device *ubi = ubi_devices[i];
 204
 205                 if (ubi && MAJOR(ubi->cdev.dev) == major) {
 206                         ubi_num = ubi->ubi_num;
 207                         break;
 208                 }
 209         }
 210         spin_unlock(&ubi_devices_lock);
 211
 212         return ubi_num;
 213 }
 214
 215 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
 216 static ssize_t dev_attribute_show(struct device *dev,
 217                                   struct device_attribute *attr, char *buf)
 218 {
 219         ssize_t ret;
 220         struct ubi_device *ubi;
 221
 222         /*
 223          * The below code looks weird, but it actually makes sense. We get the
 224          * UBI device reference from the contained 'struct ubi_device'. But it
 225          * is unclear if the device was removed or not yet. Indeed, if the
 226          * device was removed before we increased its reference count,
 227          * 'ubi_get_device()' will return -ENODEV and we fail.
 228          *
 229          * Remember, 'struct ubi_device' is freed in the release function, so
 230          * we still can use 'ubi->ubi_num'.
 231          */
 232         ubi = container_of(dev, struct ubi_device, dev);
 233         ubi = ubi_get_device(ubi->ubi_num);
 234         if (!ubi)
 235                 return -ENODEV;
 236
 237         if (attr == &dev_eraseblock_size)
 238                 ret = sprintf(buf, "%d\n", ubi->leb_size);
 239         else if (attr == &dev_avail_eraseblocks)
 240                 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
 241         else if (attr == &dev_total_eraseblocks)
 242                 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
 243         else if (attr == &dev_volumes_count)
 244                 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
 245         else if (attr == &dev_max_ec)
 246                 ret = sprintf(buf, "%d\n", ubi->max_ec);
 247         else if (attr == &dev_reserved_for_bad)
 248                 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
 249         else if (attr == &dev_bad_peb_count)
 250                 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
 251         else if (attr == &dev_max_vol_count)
 252                 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
 253         else if (attr == &dev_min_io_size)
 254                 ret = sprintf(buf, "%d\n", ubi->min_io_size);
 255         else if (attr == &dev_bgt_enabled)
 256                 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
 257         else if (attr == &dev_mtd_num)
 258                 ret = sprintf(buf, "%d\n", ubi->mtd->index);
 259         else
 260                 ret = -EINVAL;
 261
 262         ubi_put_device(ubi);
 263         return ret;
 264 }
 265
 266 static void dev_release(struct device *dev)
 267 {
 268         struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
 269
 270         kfree(ubi);
 271 }
 272
 273 /**
 274  * ubi_sysfs_init - initialize sysfs for an UBI device.
 275  * @ubi: UBI device description object
 276  *
 277  * This function returns zero in case of success and a negative error code in
 278  * case of failure.
 279  */
 280 static int ubi_sysfs_init(struct ubi_device *ubi)
 281 {
 282         int err;
 283
 284         ubi->dev.release = dev_release;
 285         ubi->dev.devt = ubi->cdev.dev;
 286         ubi->dev.class = ubi_class;
 287         dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
 288         err = device_register(&ubi->dev);
 289         if (err)
 290                 return err;
 291
 292         err = device_create_file(&ubi->dev, &dev_eraseblock_size);
 293         if (err)
 294                 return err;
 295         err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
 296         if (err)
 297                 return err;
 298         err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
 299         if (err)
 300                 return err;
 301         err = device_create_file(&ubi->dev, &dev_volumes_count);
 302         if (err)
 303                 return err;
 304         err = device_create_file(&ubi->dev, &dev_max_ec);
 305         if (err)
 306                 return err;
 307         err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
 308         if (err)
 309                 return err;
 310         err = device_create_file(&ubi->dev, &dev_bad_peb_count);
 311         if (err)
 312                 return err;
 313         err = device_create_file(&ubi->dev, &dev_max_vol_count);
 314         if (err)
 315                 return err;
 316         err = device_create_file(&ubi->dev, &dev_min_io_size);
 317         if (err)
 318                 return err;
 319         err = device_create_file(&ubi->dev, &dev_bgt_enabled);
 320         if (err)
 321                 return err;
 322         err = device_create_file(&ubi->dev, &dev_mtd_num);
 323         return err;
 324 }
 325
 326 /**
 327  * ubi_sysfs_close - close sysfs for an UBI device.
 328  * @ubi: UBI device description object
 329  */
 330 static void ubi_sysfs_close(struct ubi_device *ubi)
 331 {
 332         device_remove_file(&ubi->dev, &dev_mtd_num);
 333         device_remove_file(&ubi->dev, &dev_bgt_enabled);
 334         device_remove_file(&ubi->dev, &dev_min_io_size);
 335         device_remove_file(&ubi->dev, &dev_max_vol_count);
 336         device_remove_file(&ubi->dev, &dev_bad_peb_count);
 337         device_remove_file(&ubi->dev, &dev_reserved_for_bad);
 338         device_remove_file(&ubi->dev, &dev_max_ec);
 339         device_remove_file(&ubi->dev, &dev_volumes_count);
 340         device_remove_file(&ubi->dev, &dev_total_eraseblocks);
 341         device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
 342         device_remove_file(&ubi->dev, &dev_eraseblock_size);
 343         device_unregister(&ubi->dev);
 344 }
 345
 346 /**
 347  * kill_volumes - destroy all volumes.
 348  * @ubi: UBI device description object
 349  */
 350 static void kill_volumes(struct ubi_device *ubi)
 351 {
 352         int i;
 353
 354         for (i = 0; i < ubi->vtbl_slots; i++)
 355                 if (ubi->volumes[i])
 356                         ubi_free_volume(ubi, ubi->volumes[i]);
 357 }
 358
 359 /**
 360  * free_user_volumes - free all user volumes.
 361  * @ubi: UBI device description object
 362  *
 363  * Normally the volumes are freed at the release function of the volume device
 364  * objects. However, on error paths the volumes have to be freed before the
 365  * device objects have been initialized.
 366  */
 367 static void free_user_volumes(struct ubi_device *ubi)
 368 {
 369         int i;
 370
 371         for (i = 0; i < ubi->vtbl_slots; i++)
 372                 if (ubi->volumes[i]) {
 373                         kfree(ubi->volumes[i]->eba_tbl);
 374                         kfree(ubi->volumes[i]);
 375                 }
 376 }
 377
 378 /**
 379  * uif_init - initialize user interfaces for an UBI device.
 380  * @ubi: UBI device description object
 381  *
 382  * This function returns zero in case of success and a negative error code in
 383  * case of failure. Note, this function destroys all volumes if it failes.
 384  */
 385 static int uif_init(struct ubi_device *ubi)
 386 {
 387         int i, err;
 388         dev_t dev;
 389
 390         sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
 391
 392         /*
 393          * Major numbers for the UBI character devices are allocated
 394          * dynamically. Major numbers of volume character devices are
 395          * equivalent to ones of the corresponding UBI character device. Minor
 396          * numbers of UBI character devices are 0, while minor numbers of
 397          * volume character devices start from 1. Thus, we allocate one major
 398          * number and ubi->vtbl_slots + 1 minor numbers.
 399          */
 400         err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
 401         if (err) {
 402                 ubi_err("cannot register UBI character devices");
 403                 return err;
 404         }
 405
 406         ubi_assert(MINOR(dev) == 0);
 407         cdev_init(&ubi->cdev, &ubi_cdev_operations);
 408         dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
 409         ubi->cdev.owner = THIS_MODULE;
 410
 411         err = cdev_add(&ubi->cdev, dev, 1);
 412         if (err) {
 413                 ubi_err("cannot add character device");
 414                 goto out_unreg;
 415         }
 416
 417         err = ubi_sysfs_init(ubi);
 418         if (err)
 419                 goto out_sysfs;
 420
 421         for (i = 0; i < ubi->vtbl_slots; i++)
 422                 if (ubi->volumes[i]) {
 423                         err = ubi_add_volume(ubi, ubi->volumes[i]);
 424                         if (err) {
 425                                 ubi_err("cannot add volume %d", i);
 426                                 goto out_volumes;
 427                         }
 428                 }
 429
 430         return 0;
 431
 432 out_volumes:
 433         kill_volumes(ubi);
 434 out_sysfs:
 435         ubi_sysfs_close(ubi);
 436         cdev_del(&ubi->cdev);
 437 out_unreg:
 438         unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
 439         ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
 440         return err;
 441 }
 442
 443 /**
 444  * uif_close - close user interfaces for an UBI device.
 445  * @ubi: UBI device description object
 446  *
 447  * Note, since this function un-registers UBI volume device objects (@vol->dev),
 448  * the memory allocated voe the volumes is freed as well (in the release
 449  * function).
 450  */
 451 static void uif_close(struct ubi_device *ubi)
 452 {
 453         kill_volumes(ubi);
 454         ubi_sysfs_close(ubi);
 455         cdev_del(&ubi->cdev);
 456         unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
 457 }
 458
 459 /**
 460  * free_internal_volumes - free internal volumes.
 461  * @ubi: UBI device description object
 462  */
 463 static void free_internal_volumes(struct ubi_device *ubi)
 464 {
 465         int i;
 466
 467         for (i = ubi->vtbl_slots;
 468              i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
 469                 kfree(ubi->volumes[i]->eba_tbl);
 470                 kfree(ubi->volumes[i]);
 471         }
 472 }
 473
 474 /**
 475  * attach_by_scanning - attach an MTD device using scanning method.
 476  * @ubi: UBI device descriptor
 477  *
 478  * This function returns zero in case of success and a negative error code in
 479  * case of failure.
 480  *
 481  * Note, currently this is the only method to attach UBI devices. Hopefully in
 482  * the future we'll have more scalable attaching methods and avoid full media
 483  * scanning. But even in this case scanning will be needed as a fall-back
 484  * attaching method if there are some on-flash table corruptions.
 485  */
 486 static int attach_by_scanning(struct ubi_device *ubi)
 487 {
 488         int err;
 489         struct ubi_scan_info *si;
 490
 491         si = ubi_scan(ubi);
 492         if (IS_ERR(si))
 493                 return PTR_ERR(si);
 494
 495         ubi->bad_peb_count = si->bad_peb_count;
 496         ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
 497         ubi->max_ec = si->max_ec;
 498         ubi->mean_ec = si->mean_ec;
 499
 500         err = ubi_read_volume_table(ubi, si);
 501         if (err)
 502                 goto out_si;
 503
 504         err = ubi_wl_init_scan(ubi, si);
 505         if (err)
 506                 goto out_vtbl;
 507
 508         err = ubi_eba_init_scan(ubi, si);
 509         if (err)
 510                 goto out_wl;
 511
 512         ubi_scan_destroy_si(si);
 513         return 0;
 514
 515 out_wl:
 516         ubi_wl_close(ubi);
 517 out_vtbl:
 518         free_internal_volumes(ubi);
 519         vfree(ubi->vtbl);
 520 out_si:
 521         ubi_scan_destroy_si(si);
 522         return err;
 523 }
 524
 525 /**
 526  * io_init - initialize I/O sub-system for a given UBI device.
 527  * @ubi: UBI device description object
 528  *
 529  * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
 530  * assumed:
 531  *   o EC header is always at offset zero - this cannot be changed;
 532  *   o VID header starts just after the EC header at the closest address
 533  *     aligned to @io->hdrs_min_io_size;
 534  *   o data starts just after the VID header at the closest address aligned to
 535  *     @io->min_io_size
 536  *
 537  * This function returns zero in case of success and a negative error code in
 538  * case of failure.
 539  */
 540 static int io_init(struct ubi_device *ubi)
 541 {
 542         if (ubi->mtd->numeraseregions != 0) {
 543                 /*
 544                  * Some flashes have several erase regions. Different regions
 545                  * may have different eraseblock size and other
 546                  * characteristics. It looks like mostly multi-region flashes
 547                  * have one "main" region and one or more small regions to
 548                  * store boot loader code or boot parameters or whatever. I
 549                  * guess we should just pick the largest region. But this is
 550                  * not implemented.
 551                  */
 552                 ubi_err("multiple regions, not implemented");
 553                 return -EINVAL;
 554         }
 555
 556         if (ubi->vid_hdr_offset < 0)
 557                 return -EINVAL;
 558
 559         /*
 560          * Note, in this implementation we support MTD devices with 0x7FFFFFFF
 561          * physical eraseblocks maximum.
 562          */
 563
 564         ubi->peb_size   = ubi->mtd->erasesize;
 565         ubi->peb_count  = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
 566         ubi->flash_size = ubi->mtd->size;
 567
 568         if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
 569                 ubi->bad_allowed = 1;
 570
 571         ubi->min_io_size = ubi->mtd->writesize;
 572         ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
 573
 574         /*
 575          * Make sure minimal I/O unit is power of 2. Note, there is no
 576          * fundamental reason for this assumption. It is just an optimization
 577          * which allows us to avoid costly division operations.
 578          */
 579         if (!is_power_of_2(ubi->min_io_size)) {
 580                 ubi_err("min. I/O unit (%d) is not power of 2",
 581                         ubi->min_io_size);
 582                 return -EINVAL;
 583         }
 584
 585         ubi_assert(ubi->hdrs_min_io_size > 0);
 586         ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
 587         ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
 588
 589         /* Calculate default aligned sizes of EC and VID headers */
 590         ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
 591         ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
 592
 593         dbg_msg("min_io_size      %d", ubi->min_io_size);
 594         dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
 595         dbg_msg("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
 596         dbg_msg("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
 597
 598         if (ubi->vid_hdr_offset == 0)
 599                 /* Default offset */
 600                 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
 601                                       ubi->ec_hdr_alsize;
 602         else {
 603                 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
 604                                                 ~(ubi->hdrs_min_io_size - 1);
 605                 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
 606                                                 ubi->vid_hdr_aloffset;
 607         }
 608
 609         /* Similar for the data offset */
 610         ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
 611         ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
 612
 613         dbg_msg("vid_hdr_offset   %d", ubi->vid_hdr_offset);
 614         dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
 615         dbg_msg("vid_hdr_shift    %d", ubi->vid_hdr_shift);
 616         dbg_msg("leb_start        %d", ubi->leb_start);
 617
 618         /* The shift must be aligned to 32-bit boundary */
 619         if (ubi->vid_hdr_shift % 4) {
 620                 ubi_err("unaligned VID header shift %d",
 621                         ubi->vid_hdr_shift);
 622                 return -EINVAL;
 623         }
 624
 625         /* Check sanity */
 626         if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
 627             ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
 628             ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
 629             ubi->leb_start & (ubi->min_io_size - 1)) {
 630                 ubi_err("bad VID header (%d) or data offsets (%d)",
 631                         ubi->vid_hdr_offset, ubi->leb_start);
 632                 return -EINVAL;
 633         }
 634
 635         /*
 636          * It may happen that EC and VID headers are situated in one minimal
 637          * I/O unit. In this case we can only accept this UBI image in
 638          * read-only mode.
 639          */
 640         if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
 641                 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
 642                          "switch to read-only mode");
 643                 ubi->ro_mode = 1;
 644         }
 645
 646         ubi->leb_size = ubi->peb_size - ubi->leb_start;
 647
 648         if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
 649                 ubi_msg("MTD device %d is write-protected, attach in "
 650                         "read-only mode", ubi->mtd->index);
 651                 ubi->ro_mode = 1;
 652         }
 653
 654         ubi_msg("physical eraseblock size:   %d bytes (%d KiB)",
 655                 ubi->peb_size, ubi->peb_size >> 10);
 656         ubi_msg("logical eraseblock size:    %d bytes", ubi->leb_size);
 657         ubi_msg("smallest flash I/O unit:    %d", ubi->min_io_size);
 658         if (ubi->hdrs_min_io_size != ubi->min_io_size)
 659                 ubi_msg("sub-page size:              %d",
 660                         ubi->hdrs_min_io_size);
 661         ubi_msg("VID header offset:          %d (aligned %d)",
 662                 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
 663         ubi_msg("data offset:                %d", ubi->leb_start);
 664
 665         /*
 666          * Note, ideally, we have to initialize ubi->bad_peb_count here. But
 667          * unfortunately, MTD does not provide this information. We should loop
 668          * over all physical eraseblocks and invoke mtd->block_is_bad() for
 669          * each physical eraseblock. So, we skip ubi->bad_peb_count
 670          * uninitialized and initialize it after scanning.
 671          */
 672
 673         return 0;
 674 }
 675
 676 /**
 677  * autoresize - re-size the volume which has the "auto-resize" flag set.
 678  * @ubi: UBI device description object
 679  * @vol_id: ID of the volume to re-size
 680  *
 681  * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
 682  * the volume table to the largest possible size. See comments in ubi-header.h
 683  * for more description of the flag. Returns zero in case of success and a
 684  * negative error code in case of failure.
 685  */
 686 static int autoresize(struct ubi_device *ubi, int vol_id)
 687 {
 688         struct ubi_volume_desc desc;
 689         struct ubi_volume *vol = ubi->volumes[vol_id];
 690         int err, old_reserved_pebs = vol->reserved_pebs;
 691
 692         /*
 693          * Clear the auto-resize flag in the volume in-memory copy of the
 694          * volume table, and 'ubi_resize_volume()' will propagate this change
 695          * to the flash.
 696          */
 697         ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
 698
 699         if (ubi->avail_pebs == 0) {
 700                 struct ubi_vtbl_record vtbl_rec;
 701
 702                 /*
 703                  * No available PEBs to re-size the volume, clear the flag on
 704                  * flash and exit.
 705                  */
 706                 memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
 707                        sizeof(struct ubi_vtbl_record));
 708                 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
 709                 if (err)
 710                         ubi_err("cannot clean auto-resize flag for volume %d",
 711                                 vol_id);
 712         } else {
 713                 desc.vol = vol;
 714                 err = ubi_resize_volume(&desc,
 715                                         old_reserved_pebs + ubi->avail_pebs);
 716                 if (err)
 717                         ubi_err("cannot auto-resize volume %d", vol_id);
 718         }
 719
 720         if (err)
 721                 return err;
 722
 723         ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
 724                 vol->name, old_reserved_pebs, vol->reserved_pebs);
 725         return 0;
 726 }
 727
 728 /**
 729  * ubi_attach_mtd_dev - attach an MTD device.
 730  * @mtd: MTD device description object
 731  * @ubi_num: number to assign to the new UBI device
 732  * @vid_hdr_offset: VID header offset
 733  *
 734  * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
 735  * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
 736  * which case this function finds a vacant device number and assigns it
 737  * automatically. Returns the new UBI device number in case of success and a
 738  * negative error code in case of failure.
 739  *
 740  * Note, the invocations of this function has to be serialized by the
 741  * @ubi_devices_mutex.
 742  */
 743 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 744 {
 745         struct ubi_device *ubi;
 746         int i, err, do_free = 1;
 747
 748         /*
 749          * Check if we already have the same MTD device attached.
 750          *
 751          * Note, this function assumes that UBI devices creations and deletions
 752          * are serialized, so it does not take the &ubi_devices_lock.
 753          */
 754         for (i = 0; i < UBI_MAX_DEVICES; i++) {
 755                 ubi = ubi_devices[i];
 756                 if (ubi && mtd->index == ubi->mtd->index) {
 757                         dbg_err("mtd%d is already attached to ubi%d",
 758                                 mtd->index, i);
 759                         return -EEXIST;
 760                 }
 761         }
 762
 763         /*
 764          * Make sure this MTD device is not emulated on top of an UBI volume
 765          * already. Well, generally this recursion works fine, but there are
 766          * different problems like the UBI module takes a reference to itself
 767          * by attaching (and thus, opening) the emulated MTD device. This
 768          * results in inability to unload the module. And in general it makes
 769          * no sense to attach emulated MTD devices, so we prohibit this.
 770          */
 771         if (mtd->type == MTD_UBIVOLUME) {
 772                 ubi_err("refuse attaching mtd%d - it is already emulated on "
 773                         "top of UBI", mtd->index);
 774                 return -EINVAL;
 775         }
 776
 777         if (ubi_num == UBI_DEV_NUM_AUTO) {
 778                 /* Search for an empty slot in the @ubi_devices array */
 779                 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
 780                         if (!ubi_devices[ubi_num])
 781                                 break;
 782                 if (ubi_num == UBI_MAX_DEVICES) {
 783                         dbg_err("only %d UBI devices may be created",
 784                                 UBI_MAX_DEVICES);
 785                         return -ENFILE;
 786                 }
 787         } else {
 788                 if (ubi_num >= UBI_MAX_DEVICES)
 789                         return -EINVAL;
 790
 791                 /* Make sure ubi_num is not busy */
 792                 if (ubi_devices[ubi_num]) {
 793                         dbg_err("ubi%d already exists", ubi_num);
 794                         return -EEXIST;
 795                 }
 796         }
 797
 798         ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
 799         if (!ubi)
 800                 return -ENOMEM;
 801
 802         ubi->mtd = mtd;
 803         ubi->ubi_num = ubi_num;
 804         ubi->vid_hdr_offset = vid_hdr_offset;
 805         ubi->autoresize_vol_id = -1;
 806
 807         mutex_init(&ubi->buf_mutex);
 808         mutex_init(&ubi->ckvol_mutex);
 809         mutex_init(&ubi->mult_mutex);
 810         mutex_init(&ubi->volumes_mutex);
 811         spin_lock_init(&ubi->volumes_lock);
 812
 813         ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
 814
 815         err = io_init(ubi);
 816         if (err)
 817                 goto out_free;
 818
 819         err = -ENOMEM;
 820         ubi->peb_buf1 = vmalloc(ubi->peb_size);
 821         if (!ubi->peb_buf1)
 822                 goto out_free;
 823
 824         ubi->peb_buf2 = vmalloc(ubi->peb_size);
 825         if (!ubi->peb_buf2)
 826                 goto out_free;
 827
 828 #ifdef CONFIG_MTD_UBI_DEBUG
 829         mutex_init(&ubi->dbg_buf_mutex);
 830         ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
 831         if (!ubi->dbg_peb_buf)
 832                 goto out_free;
 833 #endif
 834
 835         err = attach_by_scanning(ubi);
 836         if (err) {
 837                 dbg_err("failed to attach by scanning, error %d", err);
 838                 goto out_free;
 839         }
 840
 841         if (ubi->autoresize_vol_id != -1) {
 842                 err = autoresize(ubi, ubi->autoresize_vol_id);
 843                 if (err)
 844                         goto out_detach;
 845         }
 846
 847         err = uif_init(ubi);
 848         if (err)
 849                 goto out_nofree;
 850
 851         ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
 852         if (IS_ERR(ubi->bgt_thread)) {
 853                 err = PTR_ERR(ubi->bgt_thread);
 854                 ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
 855                         err);
 856                 goto out_uif;
 857         }
 858
 859         ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
 860         ubi_msg("MTD device name:            \"%s\"", mtd->name);
 861         ubi_msg("MTD device size:            %llu MiB", ubi->flash_size >> 20);
 862         ubi_msg("number of good PEBs:        %d", ubi->good_peb_count);
 863         ubi_msg("number of bad PEBs:         %d", ubi->bad_peb_count);
 864         ubi_msg("max. allowed volumes:       %d", ubi->vtbl_slots);
 865         ubi_msg("wear-leveling threshold:    %d", CONFIG_MTD_UBI_WL_THRESHOLD);
 866         ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
 867         ubi_msg("number of user volumes:     %d",
 868                 ubi->vol_count - UBI_INT_VOL_COUNT);
 869         ubi_msg("available PEBs:             %d", ubi->avail_pebs);
 870         ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
 871         ubi_msg("number of PEBs reserved for bad PEB handling: %d",
 872                 ubi->beb_rsvd_pebs);
 873         ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
 874
 875         if (!DBG_DISABLE_BGT)
 876                 ubi->thread_enabled = 1;
 877         wake_up_process(ubi->bgt_thread);
 878
 879         ubi_devices[ubi_num] = ubi;
 880         return ubi_num;
 881
 882 out_uif:
 883         uif_close(ubi);
 884 out_nofree:
 885         do_free = 0;
 886 out_detach:
 887         ubi_wl_close(ubi);
 888         if (do_free)
 889                 free_user_volumes(ubi);
 890         free_internal_volumes(ubi);
 891         vfree(ubi->vtbl);
 892 out_free:
 893         vfree(ubi->peb_buf1);
 894         vfree(ubi->peb_buf2);
 895 #ifdef CONFIG_MTD_UBI_DEBUG
 896         vfree(ubi->dbg_peb_buf);
 897 #endif
 898         kfree(ubi);
 899         return err;
 900 }
 901
 902 /**
 903  * ubi_detach_mtd_dev - detach an MTD device.
 904  * @ubi_num: UBI device number to detach from
 905  * @anyway: detach MTD even if device reference count is not zero
 906  *
 907  * This function destroys an UBI device number @ubi_num and detaches the
 908  * underlying MTD device. Returns zero in case of success and %-EBUSY if the
 909  * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
 910  * exist.
 911  *
 912  * Note, the invocations of this function has to be serialized by the
 913  * @ubi_devices_mutex.
 914  */
 915 int ubi_detach_mtd_dev(int ubi_num, int anyway)
 916 {
 917         struct ubi_device *ubi;
 918
 919         if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
 920                 return -EINVAL;
 921
 922         spin_lock(&ubi_devices_lock);
 923         ubi = ubi_devices[ubi_num];
 924         if (!ubi) {
 925                 spin_unlock(&ubi_devices_lock);
 926                 return -EINVAL;
 927         }
 928
 929         if (ubi->ref_count) {
 930                 if (!anyway) {
 931                         spin_unlock(&ubi_devices_lock);
 932                         return -EBUSY;
 933                 }
 934                 /* This may only happen if there is a bug */
 935                 ubi_err("%s reference count %d, destroy anyway",
 936                         ubi->ubi_name, ubi->ref_count);
 937         }
 938         ubi_devices[ubi_num] = NULL;
 939         spin_unlock(&ubi_devices_lock);
 940
 941         ubi_assert(ubi_num == ubi->ubi_num);
 942         dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
 943
 944         /*
 945          * Before freeing anything, we have to stop the background thread to
 946          * prevent it from doing anything on this device while we are freeing.
 947          */
 948         if (ubi->bgt_thread)
 949                 kthread_stop(ubi->bgt_thread);
 950
 951         /*
 952          * Get a reference to the device in order to prevent 'dev_release()'
 953          * from freeing @ubi object.
 954          */
 955         get_device(&ubi->dev);
 956
 957         uif_close(ubi);
 958         ubi_wl_close(ubi);
 959         free_internal_volumes(ubi);
 960         vfree(ubi->vtbl);
 961         put_mtd_device(ubi->mtd);
 962         vfree(ubi->peb_buf1);
 963         vfree(ubi->peb_buf2);
 964 #ifdef CONFIG_MTD_UBI_DEBUG
 965         vfree(ubi->dbg_peb_buf);
 966 #endif
 967         ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
 968         put_device(&ubi->dev);
 969         return 0;
 970 }
 971
 972 /**
 973  * find_mtd_device - open an MTD device by its name or number.
 974  * @mtd_dev: name or number of the device
 975  *
 976  * This function tries to open and MTD device described by @mtd_dev string,
 977  * which is first treated as an ASCII number, and if it is not true, it is
 978  * treated as MTD device name. Returns MTD device description object in case of
 979  * success and a negative error code in case of failure.
 980  */
 981 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
 982 {
 983         struct mtd_info *mtd;
 984         int mtd_num;
 985         char *endp;
 986
 987         mtd_num = simple_strtoul(mtd_dev, &endp, 0);
 988         if (*endp != '\0' || mtd_dev == endp) {
 989                 /*
 990                  * This does not look like an ASCII integer, probably this is
 991                  * MTD device name.
 992                  */
 993                 mtd = get_mtd_device_nm(mtd_dev);
 994         } else
 995                 mtd = get_mtd_device(NULL, mtd_num);
 996
 997         return mtd;
 998 }
 999
1000 static int __init ubi_init(void)
1001 {
1002         int err, i, k;
1003
1004         /* Ensure that EC and VID headers have correct size */
1005         BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1006         BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1007
1008         if (mtd_devs > UBI_MAX_DEVICES) {
1009                 ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
1010                 return -EINVAL;
1011         }
1012
1013         /* Create base sysfs directory and sysfs files */
1014         ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
1015         if (IS_ERR(ubi_class)) {
1016                 err = PTR_ERR(ubi_class);
1017                 ubi_err("cannot create UBI class");
1018                 goto out;
1019         }
1020
1021         err = class_create_file(ubi_class, &ubi_version);
1022         if (err) {
1023                 ubi_err("cannot create sysfs file");
1024                 goto out_class;
1025         }
1026
1027         err = misc_register(&ubi_ctrl_cdev);
1028         if (err) {
1029                 ubi_err("cannot register device");
1030                 goto out_version;
1031         }
1032
1033         ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1034                                               sizeof(struct ubi_wl_entry),
1035                                               0, 0, NULL);
1036         if (!ubi_wl_entry_slab)
1037                 goto out_dev_unreg;
1038
1039         /* Attach MTD devices */
1040         for (i = 0; i < mtd_devs; i++) {
1041                 struct mtd_dev_param *p = &mtd_dev_param[i];
1042                 struct mtd_info *mtd;
1043
1044                 cond_resched();
1045
1046                 mtd = open_mtd_device(p->name);
1047                 if (IS_ERR(mtd)) {
1048                         err = PTR_ERR(mtd);
1049                         goto out_detach;
1050                 }
1051
1052                 mutex_lock(&ubi_devices_mutex);
1053                 err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
1054                                          p->vid_hdr_offs);
1055                 mutex_unlock(&ubi_devices_mutex);
1056                 if (err < 0) {
1057                         put_mtd_device(mtd);
1058                         ubi_err("cannot attach mtd%d", mtd->index);
1059                         goto out_detach;
1060                 }
1061         }
1062
1063         return 0;
1064
1065 out_detach:
1066         for (k = 0; k < i; k++)
1067                 if (ubi_devices[k]) {
1068                         mutex_lock(&ubi_devices_mutex);
1069                         ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1070                         mutex_unlock(&ubi_devices_mutex);
1071                 }
1072         kmem_cache_destroy(ubi_wl_entry_slab);
1073 out_dev_unreg:
1074         misc_deregister(&ubi_ctrl_cdev);
1075 out_version:
1076         class_remove_file(ubi_class, &ubi_version);
1077 out_class:
1078         class_destroy(ubi_class);
1079 out:
1080         ubi_err("UBI error: cannot initialize UBI, error %d", err);
1081         return err;
1082 }
1083 module_init(ubi_init);
1084
1085 static void __exit ubi_exit(void)
1086 {
1087         int i;
1088
1089         for (i = 0; i < UBI_MAX_DEVICES; i++)
1090                 if (ubi_devices[i]) {
1091                         mutex_lock(&ubi_devices_mutex);
1092                         ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1093                         mutex_unlock(&ubi_devices_mutex);
1094                 }
1095         kmem_cache_destroy(ubi_wl_entry_slab);
1096         misc_deregister(&ubi_ctrl_cdev);
1097         class_remove_file(ubi_class, &ubi_version);
1098         class_destroy(ubi_class);
1099 }
1100 module_exit(ubi_exit);
1101
1102 /**
1103  * bytes_str_to_int - convert a number of bytes string into an integer.
1104  * @str: the string to convert
1105  *
1106  * This function returns positive resulting integer in case of success and a
1107  * negative error code in case of failure.
1108  */
1109 static int __init bytes_str_to_int(const char *str)
1110 {
1111         char *endp;
1112         unsigned long result;
1113
1114         result = simple_strtoul(str, &endp, 0);
1115         if (str == endp || result < 0) {
1116                 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1117                        str);
1118                 return -EINVAL;
1119         }
1120
1121         switch (*endp) {
1122         case 'G':
1123                 result *= 1024;
1124         case 'M':
1125                 result *= 1024;
1126         case 'K':
1127                 result *= 1024;
1128                 if (endp[1] == 'i' && endp[2] == 'B')
1129                         endp += 2;
1130         case '\0':
1131                 break;
1132         default:
1133                 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1134                        str);
1135                 return -EINVAL;
1136         }
1137
1138         return result;
1139 }
1140
1141 /**
1142  * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1143  * @val: the parameter value to parse
1144  * @kp: not used
1145  *
1146  * This function returns zero in case of success and a negative error code in
1147  * case of error.
1148  */
1149 static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1150 {
1151         int i, len;
1152         struct mtd_dev_param *p;
1153         char buf[MTD_PARAM_LEN_MAX];
1154         char *pbuf = &buf[0];
1155         char *tokens[2] = {NULL, NULL};
1156
1157         if (!val)
1158                 return -EINVAL;
1159
1160         if (mtd_devs == UBI_MAX_DEVICES) {
1161                 printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
1162                        UBI_MAX_DEVICES);
1163                 return -EINVAL;
1164         }
1165
1166         len = strnlen(val, MTD_PARAM_LEN_MAX);
1167         if (len == MTD_PARAM_LEN_MAX) {
1168                 printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
1169                        "max. is %d\n", val, MTD_PARAM_LEN_MAX);
1170                 return -EINVAL;
1171         }
1172
1173         if (len == 0) {
1174                 printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
1175                        "ignored\n");
1176                 return 0;
1177         }
1178
1179         strcpy(buf, val);
1180
1181         /* Get rid of the final newline */
1182         if (buf[len - 1] == '\n')
1183                 buf[len - 1] = '\0';
1184
1185         for (i = 0; i < 2; i++)
1186                 tokens[i] = strsep(&pbuf, ",");
1187
1188         if (pbuf) {
1189                 printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
1190                        val);
1191                 return -EINVAL;
1192         }
1193
1194         p = &mtd_dev_param[mtd_devs];
1195         strcpy(&p->name[0], tokens[0]);
1196
1197         if (tokens[1])
1198                 p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
1199
1200         if (p->vid_hdr_offs < 0)
1201                 return p->vid_hdr_offs;
1202
1203         mtd_devs += 1;
1204         return 0;
1205 }
1206
1207 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1208 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
1209                       "mtd=<name|num>[,<vid_hdr_offs>].\n"
1210                       "Multiple \"mtd\" parameters may be specified.\n"
1211                       "MTD devices may be specified by their number or name.\n"
1212                       "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
1213                       "header position and data starting position to be used "
1214                       "by UBI.\n"
1215                       "Example: mtd=content,1984 mtd=4 - attach MTD device"
1216                       "with name \"content\" using VID header offset 1984, and "
1217                       "MTD device number 4 with default VID header offset.");
1218
1219 MODULE_VERSION(__stringify(UBI_VERSION));
1220 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1221 MODULE_AUTHOR("Artem Bityutskiy");
1222 MODULE_LICENSE("GPL");