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