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. At the
  25  * moment UBI devices may only be added while UBI is initialized, but dynamic
  26  * device add/remove functionality is planned. Also, at the moment we only
  27  * attach UBI devices by scanning, which will become a bottleneck when flashes
  28  * reach certain large size. Then one may improve UBI and add other methods.
  29  */
  30
  31 #include <linux/err.h>
  32 #include <linux/module.h>
  33 #include <linux/moduleparam.h>
  34 #include <linux/stringify.h>
  35 #include <linux/stat.h>
  36 #include <linux/log2.h>
  37 #include "ubi.h"
  38
  39 /* Maximum length of the 'mtd=' parameter */
  40 #define MTD_PARAM_LEN_MAX 64
  41
  42 /**
  43  * struct mtd_dev_param - MTD device parameter description data structure.
  44  * @name: MTD device name or number string
  45  * @vid_hdr_offs: VID header offset
  46  * @data_offs: data offset
  47  */
  48 struct mtd_dev_param
  49 {
  50         char name[MTD_PARAM_LEN_MAX];
  51         int vid_hdr_offs;
  52         int data_offs;
  53 };
  54
  55 /* Numbers of elements set in the @mtd_dev_param array */
  56 static int mtd_devs = 0;
  57
  58 /* MTD devices specification parameters */
  59 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
  60
  61 /* Number of UBI devices in system */
  62 int ubi_devices_cnt;
  63
  64 /* All UBI devices in system */
  65 struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
  66
  67 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
  68 struct class *ubi_class;
  69
  70 /* "Show" method for files in '/<sysfs>/class/ubi/' */
  71 static ssize_t ubi_version_show(struct class *class, char *buf)
  72 {
  73         return sprintf(buf, "%d\n", UBI_VERSION);
  74 }
  75
  76 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
  77 static struct class_attribute ubi_version =
  78         __ATTR(version, S_IRUGO, ubi_version_show, NULL);
  79
  80 static ssize_t dev_attribute_show(struct device *dev,
  81                                   struct device_attribute *attr, char *buf);
  82
  83 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
  84 static struct device_attribute dev_eraseblock_size =
  85         __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
  86 static struct device_attribute dev_avail_eraseblocks =
  87         __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
  88 static struct device_attribute dev_total_eraseblocks =
  89         __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
  90 static struct device_attribute dev_volumes_count =
  91         __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
  92 static struct device_attribute dev_max_ec =
  93         __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
  94 static struct device_attribute dev_reserved_for_bad =
  95         __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
  96 static struct device_attribute dev_bad_peb_count =
  97         __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
  98 static struct device_attribute dev_max_vol_count =
  99         __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
 100 static struct device_attribute dev_min_io_size =
 101         __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
 102 static struct device_attribute dev_bgt_enabled =
 103         __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
 104
 105 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
 106 static ssize_t dev_attribute_show(struct device *dev,
 107                                   struct device_attribute *attr, char *buf)
 108 {
 109         const struct ubi_device *ubi;
 110
 111         ubi = container_of(dev, struct ubi_device, dev);
 112         if (attr == &dev_eraseblock_size)
 113                 return sprintf(buf, "%d\n", ubi->leb_size);
 114         else if (attr == &dev_avail_eraseblocks)
 115                 return sprintf(buf, "%d\n", ubi->avail_pebs);
 116         else if (attr == &dev_total_eraseblocks)
 117                 return sprintf(buf, "%d\n", ubi->good_peb_count);
 118         else if (attr == &dev_volumes_count)
 119                 return sprintf(buf, "%d\n", ubi->vol_count);
 120         else if (attr == &dev_max_ec)
 121                 return sprintf(buf, "%d\n", ubi->max_ec);
 122         else if (attr == &dev_reserved_for_bad)
 123                 return sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
 124         else if (attr == &dev_bad_peb_count)
 125                 return sprintf(buf, "%d\n", ubi->bad_peb_count);
 126         else if (attr == &dev_max_vol_count)
 127                 return sprintf(buf, "%d\n", ubi->vtbl_slots);
 128         else if (attr == &dev_min_io_size)
 129                 return sprintf(buf, "%d\n", ubi->min_io_size);
 130         else if (attr == &dev_bgt_enabled)
 131                 return sprintf(buf, "%d\n", ubi->thread_enabled);
 132         else
 133                 BUG();
 134
 135         return 0;
 136 }
 137
 138 /* Fake "release" method for UBI devices */
 139 static void dev_release(struct device *dev) { }
 140
 141 /**
 142  * ubi_sysfs_init - initialize sysfs for an UBI device.
 143  * @ubi: UBI device description object
 144  *
 145  * This function returns zero in case of success and a negative error code in
 146  * case of failure.
 147  */
 148 static int ubi_sysfs_init(struct ubi_device *ubi)
 149 {
 150         int err;
 151
 152         ubi->dev.release = dev_release;
 153         ubi->dev.devt = MKDEV(ubi->major, 0);
 154         ubi->dev.class = ubi_class;
 155         sprintf(&ubi->dev.bus_id[0], UBI_NAME_STR"%d", ubi->ubi_num);
 156         err = device_register(&ubi->dev);
 157         if (err)
 158                 goto out;
 159
 160         err = device_create_file(&ubi->dev, &dev_eraseblock_size);
 161         if (err)
 162                 goto out_unregister;
 163         err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
 164         if (err)
 165                 goto out_eraseblock_size;
 166         err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
 167         if (err)
 168                 goto out_avail_eraseblocks;
 169         err = device_create_file(&ubi->dev, &dev_volumes_count);
 170         if (err)
 171                 goto out_total_eraseblocks;
 172         err = device_create_file(&ubi->dev, &dev_max_ec);
 173         if (err)
 174                 goto out_volumes_count;
 175         err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
 176         if (err)
 177                 goto out_volumes_max_ec;
 178         err = device_create_file(&ubi->dev, &dev_bad_peb_count);
 179         if (err)
 180                 goto out_reserved_for_bad;
 181         err = device_create_file(&ubi->dev, &dev_max_vol_count);
 182         if (err)
 183                 goto out_bad_peb_count;
 184         err = device_create_file(&ubi->dev, &dev_min_io_size);
 185         if (err)
 186                 goto out_max_vol_count;
 187         err = device_create_file(&ubi->dev, &dev_bgt_enabled);
 188         if (err)
 189                 goto out_min_io_size;
 190
 191         return 0;
 192
 193 out_min_io_size:
 194         device_remove_file(&ubi->dev, &dev_min_io_size);
 195 out_max_vol_count:
 196         device_remove_file(&ubi->dev, &dev_max_vol_count);
 197 out_bad_peb_count:
 198         device_remove_file(&ubi->dev, &dev_bad_peb_count);
 199 out_reserved_for_bad:
 200         device_remove_file(&ubi->dev, &dev_reserved_for_bad);
 201 out_volumes_max_ec:
 202         device_remove_file(&ubi->dev, &dev_max_ec);
 203 out_volumes_count:
 204         device_remove_file(&ubi->dev, &dev_volumes_count);
 205 out_total_eraseblocks:
 206         device_remove_file(&ubi->dev, &dev_total_eraseblocks);
 207 out_avail_eraseblocks:
 208         device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
 209 out_eraseblock_size:
 210         device_remove_file(&ubi->dev, &dev_eraseblock_size);
 211 out_unregister:
 212         device_unregister(&ubi->dev);
 213 out:
 214         ubi_err("failed to initialize sysfs for %s", ubi->ubi_name);
 215         return err;
 216 }
 217
 218 /**
 219  * ubi_sysfs_close - close sysfs for an UBI device.
 220  * @ubi: UBI device description object
 221  */
 222 static void ubi_sysfs_close(struct ubi_device *ubi)
 223 {
 224         device_remove_file(&ubi->dev, &dev_bgt_enabled);
 225         device_remove_file(&ubi->dev, &dev_min_io_size);
 226         device_remove_file(&ubi->dev, &dev_max_vol_count);
 227         device_remove_file(&ubi->dev, &dev_bad_peb_count);
 228         device_remove_file(&ubi->dev, &dev_reserved_for_bad);
 229         device_remove_file(&ubi->dev, &dev_max_ec);
 230         device_remove_file(&ubi->dev, &dev_volumes_count);
 231         device_remove_file(&ubi->dev, &dev_total_eraseblocks);
 232         device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
 233         device_remove_file(&ubi->dev, &dev_eraseblock_size);
 234         device_unregister(&ubi->dev);
 235 }
 236
 237 /**
 238  * kill_volumes - destroy all volumes.
 239  * @ubi: UBI device description object
 240  */
 241 static void kill_volumes(struct ubi_device *ubi)
 242 {
 243         int i;
 244
 245         for (i = 0; i < ubi->vtbl_slots; i++)
 246                 if (ubi->volumes[i])
 247                         ubi_free_volume(ubi, i);
 248 }
 249
 250 /**
 251  * uif_init - initialize user interfaces for an UBI device.
 252  * @ubi: UBI device description object
 253  *
 254  * This function returns zero in case of success and a negative error code in
 255  * case of failure.
 256  */
 257 static int uif_init(struct ubi_device *ubi)
 258 {
 259         int i, err;
 260         dev_t dev;
 261
 262         mutex_init(&ubi->vtbl_mutex);
 263         spin_lock_init(&ubi->volumes_lock);
 264
 265         sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
 266
 267         /*
 268          * Major numbers for the UBI character devices are allocated
 269          * dynamically. Major numbers of volume character devices are
 270          * equivalent to ones of the corresponding UBI character device. Minor
 271          * numbers of UBI character devices are 0, while minor numbers of
 272          * volume character devices start from 1. Thus, we allocate one major
 273          * number and ubi->vtbl_slots + 1 minor numbers.
 274          */
 275         err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
 276         if (err) {
 277                 ubi_err("cannot register UBI character devices");
 278                 return err;
 279         }
 280
 281         cdev_init(&ubi->cdev, &ubi_cdev_operations);
 282         ubi->major = MAJOR(dev);
 283         dbg_msg("%s major is %u", ubi->ubi_name, ubi->major);
 284         ubi->cdev.owner = THIS_MODULE;
 285
 286         dev = MKDEV(ubi->major, 0);
 287         err = cdev_add(&ubi->cdev, dev, 1);
 288         if (err) {
 289                 ubi_err("cannot add character device %s", ubi->ubi_name);
 290                 goto out_unreg;
 291         }
 292
 293         err = ubi_sysfs_init(ubi);
 294         if (err)
 295                 goto out_cdev;
 296
 297         for (i = 0; i < ubi->vtbl_slots; i++)
 298                 if (ubi->volumes[i]) {
 299                         err = ubi_add_volume(ubi, i);
 300                         if (err)
 301                                 goto out_volumes;
 302                 }
 303
 304         return 0;
 305
 306 out_volumes:
 307         kill_volumes(ubi);
 308         ubi_sysfs_close(ubi);
 309 out_cdev:
 310         cdev_del(&ubi->cdev);
 311 out_unreg:
 312         unregister_chrdev_region(MKDEV(ubi->major, 0),
 313                                  ubi->vtbl_slots + 1);
 314         return err;
 315 }
 316
 317 /**
 318  * uif_close - close user interfaces for an UBI device.
 319  * @ubi: UBI device description object
 320  */
 321 static void uif_close(struct ubi_device *ubi)
 322 {
 323         kill_volumes(ubi);
 324         ubi_sysfs_close(ubi);
 325         cdev_del(&ubi->cdev);
 326         unregister_chrdev_region(MKDEV(ubi->major, 0), ubi->vtbl_slots + 1);
 327 }
 328
 329 /**
 330  * attach_by_scanning - attach an MTD device using scanning method.
 331  * @ubi: UBI device descriptor
 332  *
 333  * This function returns zero in case of success and a negative error code in
 334  * case of failure.
 335  *
 336  * Note, currently this is the only method to attach UBI devices. Hopefully in
 337  * the future we'll have more scalable attaching methods and avoid full media
 338  * scanning. But even in this case scanning will be needed as a fall-back
 339  * attaching method if there are some on-flash table corruptions.
 340  */
 341 static int attach_by_scanning(struct ubi_device *ubi)
 342 {
 343         int err;
 344         struct ubi_scan_info *si;
 345
 346         si = ubi_scan(ubi);
 347         if (IS_ERR(si))
 348                 return PTR_ERR(si);
 349
 350         ubi->bad_peb_count = si->bad_peb_count;
 351         ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
 352         ubi->max_ec = si->max_ec;
 353         ubi->mean_ec = si->mean_ec;
 354
 355         err = ubi_read_volume_table(ubi, si);
 356         if (err)
 357                 goto out_si;
 358
 359         err = ubi_wl_init_scan(ubi, si);
 360         if (err)
 361                 goto out_vtbl;
 362
 363         err = ubi_eba_init_scan(ubi, si);
 364         if (err)
 365                 goto out_wl;
 366
 367         ubi_scan_destroy_si(si);
 368         return 0;
 369
 370 out_wl:
 371         ubi_wl_close(ubi);
 372 out_vtbl:
 373         vfree(ubi->vtbl);
 374 out_si:
 375         ubi_scan_destroy_si(si);
 376         return err;
 377 }
 378
 379 /**
 380  * io_init - initialize I/O unit for a given UBI device.
 381  * @ubi: UBI device description object
 382  *
 383  * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
 384  * assumed:
 385  *   o EC header is always at offset zero - this cannot be changed;
 386  *   o VID header starts just after the EC header at the closest address
 387  *   aligned to @io->@hdrs_min_io_size;
 388  *   o data starts just after the VID header at the closest address aligned to
 389  *     @io->@min_io_size
 390  *
 391  * This function returns zero in case of success and a negative error code in
 392  * case of failure.
 393  */
 394 static int io_init(struct ubi_device *ubi)
 395 {
 396         if (ubi->mtd->numeraseregions != 0) {
 397                 /*
 398                  * Some flashes have several erase regions. Different regions
 399                  * may have different eraseblock size and other
 400                  * characteristics. It looks like mostly multi-region flashes
 401                  * have one "main" region and one or more small regions to
 402                  * store boot loader code or boot parameters or whatever. I
 403                  * guess we should just pick the largest region. But this is
 404                  * not implemented.
 405                  */
 406                 ubi_err("multiple regions, not implemented");
 407                 return -EINVAL;
 408         }
 409
 410         /*
 411          * Note, in this implementation we support MTD devices with 0x7FFFFFFF
 412          * physical eraseblocks maximum.
 413          */
 414
 415         ubi->peb_size   = ubi->mtd->erasesize;
 416         ubi->peb_count  = ubi->mtd->size / ubi->mtd->erasesize;
 417         ubi->flash_size = ubi->mtd->size;
 418
 419         if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
 420                 ubi->bad_allowed = 1;
 421
 422         ubi->min_io_size = ubi->mtd->writesize;
 423         ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
 424
 425         /* Make sure minimal I/O unit is power of 2 */
 426         if (!is_power_of_2(ubi->min_io_size)) {
 427                 ubi_err("bad min. I/O unit");
 428                 return -EINVAL;
 429         }
 430
 431         ubi_assert(ubi->hdrs_min_io_size > 0);
 432         ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
 433         ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
 434
 435         /* Calculate default aligned sizes of EC and VID headers */
 436         ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
 437         ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
 438
 439         dbg_msg("min_io_size      %d", ubi->min_io_size);
 440         dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
 441         dbg_msg("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
 442         dbg_msg("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
 443
 444         if (ubi->vid_hdr_offset == 0)
 445                 /* Default offset */
 446                 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
 447                                       ubi->ec_hdr_alsize;
 448         else {
 449                 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
 450                                                 ~(ubi->hdrs_min_io_size - 1);
 451                 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
 452                                                 ubi->vid_hdr_aloffset;
 453         }
 454
 455         /* Similar for the data offset */
 456         if (ubi->leb_start == 0) {
 457                 ubi->leb_start = ubi->vid_hdr_offset + ubi->vid_hdr_alsize;
 458                 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
 459         }
 460
 461         dbg_msg("vid_hdr_offset   %d", ubi->vid_hdr_offset);
 462         dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
 463         dbg_msg("vid_hdr_shift    %d", ubi->vid_hdr_shift);
 464         dbg_msg("leb_start        %d", ubi->leb_start);
 465
 466         /* The shift must be aligned to 32-bit boundary */
 467         if (ubi->vid_hdr_shift % 4) {
 468                 ubi_err("unaligned VID header shift %d",
 469                         ubi->vid_hdr_shift);
 470                 return -EINVAL;
 471         }
 472
 473         /* Check sanity */
 474         if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
 475             ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
 476             ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
 477             ubi->leb_start % ubi->min_io_size) {
 478                 ubi_err("bad VID header (%d) or data offsets (%d)",
 479                         ubi->vid_hdr_offset, ubi->leb_start);
 480                 return -EINVAL;
 481         }
 482
 483         /*
 484          * It may happen that EC and VID headers are situated in one minimal
 485          * I/O unit. In this case we can only accept this UBI image in
 486          * read-only mode.
 487          */
 488         if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
 489                 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
 490                          "switch to read-only mode");
 491                 ubi->ro_mode = 1;
 492         }
 493
 494         ubi->leb_size = ubi->peb_size - ubi->leb_start;
 495
 496         if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
 497                 ubi_msg("MTD device %d is write-protected, attach in "
 498                         "read-only mode", ubi->mtd->index);
 499                 ubi->ro_mode = 1;
 500         }
 501
 502         dbg_msg("leb_size         %d", ubi->leb_size);
 503         dbg_msg("ro_mode          %d", ubi->ro_mode);
 504
 505         /*
 506          * Note, ideally, we have to initialize ubi->bad_peb_count here. But
 507          * unfortunately, MTD does not provide this information. We should loop
 508          * over all physical eraseblocks and invoke mtd->block_is_bad() for
 509          * each physical eraseblock. So, we skip ubi->bad_peb_count
 510          * uninitialized and initialize it after scanning.
 511          */
 512
 513         return 0;
 514 }
 515
 516 /**
 517  * attach_mtd_dev - attach an MTD device.
 518  * @mtd_dev: MTD device name or number string
 519  * @vid_hdr_offset: VID header offset
 520  * @data_offset: data offset
 521  *
 522  * This function attaches an MTD device to UBI. It first treats @mtd_dev as the
 523  * MTD device name, and tries to open it by this name. If it is unable to open,
 524  * it tries to convert @mtd_dev to an integer and open the MTD device by its
 525  * number. Returns zero in case of success and a negative error code in case of
 526  * failure.
 527  */
 528 static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
 529                           int data_offset)
 530 {
 531         struct ubi_device *ubi;
 532         struct mtd_info *mtd;
 533         int i, err;
 534
 535         mtd = get_mtd_device_nm(mtd_dev);
 536         if (IS_ERR(mtd)) {
 537                 int mtd_num;
 538                 char *endp;
 539
 540                 if (PTR_ERR(mtd) != -ENODEV)
 541                         return PTR_ERR(mtd);
 542
 543                 /*
 544                  * Probably this is not MTD device name but MTD device number -
 545                  * check this out.
 546                  */
 547                 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
 548                 if (*endp != '\0' || mtd_dev == endp) {
 549                         ubi_err("incorrect MTD device: \"%s\"", mtd_dev);
 550                         return -ENODEV;
 551                 }
 552
 553                 mtd = get_mtd_device(NULL, mtd_num);
 554                 if (IS_ERR(mtd))
 555                         return PTR_ERR(mtd);
 556         }
 557
 558         /* Check if we already have the same MTD device attached */
 559         for (i = 0; i < ubi_devices_cnt; i++)
 560                 if (ubi_devices[i]->mtd->index == mtd->index) {
 561                         ubi_err("mtd%d is already attached to ubi%d",
 562                                 mtd->index, i);
 563                         err = -EINVAL;
 564                         goto out_mtd;
 565                 }
 566
 567         ubi = ubi_devices[ubi_devices_cnt] = kzalloc(sizeof(struct ubi_device),
 568                                                       GFP_KERNEL);
 569         if (!ubi) {
 570                 err = -ENOMEM;
 571                 goto out_mtd;
 572         }
 573
 574         ubi->ubi_num = ubi_devices_cnt;
 575         ubi->mtd = mtd;
 576
 577         dbg_msg("attaching mtd%d to ubi%d: VID header offset %d data offset %d",
 578                 ubi->mtd->index, ubi_devices_cnt, vid_hdr_offset, data_offset);
 579
 580         ubi->vid_hdr_offset = vid_hdr_offset;
 581         ubi->leb_start = data_offset;
 582         err = io_init(ubi);
 583         if (err)
 584                 goto out_free;
 585
 586         err = attach_by_scanning(ubi);
 587         if (err) {
 588                 dbg_err("failed to attach by scanning, error %d", err);
 589                 goto out_free;
 590         }
 591
 592         err = uif_init(ubi);
 593         if (err)
 594                 goto out_detach;
 595
 596         ubi_msg("attached mtd%d to ubi%d", ubi->mtd->index, ubi_devices_cnt);
 597         ubi_msg("MTD device name:            \"%s\"", ubi->mtd->name);
 598         ubi_msg("MTD device size:            %llu MiB", ubi->flash_size >> 20);
 599         ubi_msg("physical eraseblock size:   %d bytes (%d KiB)",
 600                 ubi->peb_size, ubi->peb_size >> 10);
 601         ubi_msg("logical eraseblock size:    %d bytes", ubi->leb_size);
 602         ubi_msg("number of good PEBs:        %d", ubi->good_peb_count);
 603         ubi_msg("number of bad PEBs:         %d", ubi->bad_peb_count);
 604         ubi_msg("smallest flash I/O unit:    %d", ubi->min_io_size);
 605         ubi_msg("VID header offset:          %d (aligned %d)",
 606                 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
 607         ubi_msg("data offset:                %d", ubi->leb_start);
 608         ubi_msg("max. allowed volumes:       %d", ubi->vtbl_slots);
 609         ubi_msg("wear-leveling threshold:    %d", CONFIG_MTD_UBI_WL_THRESHOLD);
 610         ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
 611         ubi_msg("number of user volumes:     %d",
 612                 ubi->vol_count - UBI_INT_VOL_COUNT);
 613         ubi_msg("available PEBs:             %d", ubi->avail_pebs);
 614         ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
 615         ubi_msg("number of PEBs reserved for bad PEB handling: %d",
 616                 ubi->beb_rsvd_pebs);
 617         ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
 618
 619         /* Enable the background thread */
 620         if (!DBG_DISABLE_BGT) {
 621                 ubi->thread_enabled = 1;
 622                 wake_up_process(ubi->bgt_thread);
 623         }
 624
 625         ubi_devices_cnt += 1;
 626         return 0;
 627
 628 out_detach:
 629         ubi_eba_close(ubi);
 630         ubi_wl_close(ubi);
 631         vfree(ubi->vtbl);
 632 out_free:
 633         kfree(ubi);
 634 out_mtd:
 635         put_mtd_device(mtd);
 636         ubi_devices[ubi_devices_cnt] = NULL;
 637         return err;
 638 }
 639
 640 /**
 641  * detach_mtd_dev - detach an MTD device.
 642  * @ubi: UBI device description object
 643  */
 644 static void detach_mtd_dev(struct ubi_device *ubi)
 645 {
 646         int ubi_num = ubi->ubi_num, mtd_num = ubi->mtd->index;
 647
 648         dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
 649         uif_close(ubi);
 650         ubi_eba_close(ubi);
 651         ubi_wl_close(ubi);
 652         vfree(ubi->vtbl);
 653         put_mtd_device(ubi->mtd);
 654         kfree(ubi_devices[ubi_num]);
 655         ubi_devices[ubi_num] = NULL;
 656         ubi_devices_cnt -= 1;
 657         ubi_assert(ubi_devices_cnt >= 0);
 658         ubi_msg("mtd%d is detached from ubi%d", mtd_num, ubi_num);
 659 }
 660
 661 static int __init ubi_init(void)
 662 {
 663         int err, i, k;
 664
 665         /* Ensure that EC and VID headers have correct size */
 666         BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
 667         BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
 668
 669         if (mtd_devs > UBI_MAX_DEVICES) {
 670                 printk("UBI error: too many MTD devices, maximum is %d\n",
 671                        UBI_MAX_DEVICES);
 672                 return -EINVAL;
 673         }
 674
 675         ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
 676         if (IS_ERR(ubi_class))
 677                 return PTR_ERR(ubi_class);
 678
 679         err = class_create_file(ubi_class, &ubi_version);
 680         if (err)
 681                 goto out_class;
 682
 683         /* Attach MTD devices */
 684         for (i = 0; i < mtd_devs; i++) {
 685                 struct mtd_dev_param *p = &mtd_dev_param[i];
 686
 687                 cond_resched();
 688                 err = attach_mtd_dev(p->name, p->vid_hdr_offs, p->data_offs);
 689                 if (err)
 690                         goto out_detach;
 691         }
 692
 693         return 0;
 694
 695 out_detach:
 696         for (k = 0; k < i; k++)
 697                 detach_mtd_dev(ubi_devices[k]);
 698         class_remove_file(ubi_class, &ubi_version);
 699 out_class:
 700         class_destroy(ubi_class);
 701         return err;
 702 }
 703 module_init(ubi_init);
 704
 705 static void __exit ubi_exit(void)
 706 {
 707         int i, n = ubi_devices_cnt;
 708
 709         for (i = 0; i < n; i++)
 710                 detach_mtd_dev(ubi_devices[i]);
 711         class_remove_file(ubi_class, &ubi_version);
 712         class_destroy(ubi_class);
 713 }
 714 module_exit(ubi_exit);
 715
 716 /**
 717  * bytes_str_to_int - convert a string representing number of bytes to an
 718  * integer.
 719  * @str: the string to convert
 720  *
 721  * This function returns positive resulting integer in case of success and a
 722  * negative error code in case of failure.
 723  */
 724 static int __init bytes_str_to_int(const char *str)
 725 {
 726         char *endp;
 727         unsigned long result;
 728
 729         result = simple_strtoul(str, &endp, 0);
 730         if (str == endp || result < 0) {
 731                 printk("UBI error: incorrect bytes count: \"%s\"\n", str);
 732                 return -EINVAL;
 733         }
 734
 735         switch (*endp) {
 736         case 'G':
 737                 result *= 1024;
 738         case 'M':
 739                 result *= 1024;
 740         case 'K':
 741         case 'k':
 742                 result *= 1024;
 743                 if (endp[1] == 'i' && (endp[2] == '\0' ||
 744                           endp[2] == 'B'  || endp[2] == 'b'))
 745                         endp += 2;
 746         case '\0':
 747                 break;
 748         default:
 749                 printk("UBI error: incorrect bytes count: \"%s\"\n", str);
 750                 return -EINVAL;
 751         }
 752
 753         return result;
 754 }
 755
 756 /**
 757  * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
 758  * @val: the parameter value to parse
 759  * @kp: not used
 760  *
 761  * This function returns zero in case of success and a negative error code in
 762  * case of error.
 763  */
 764 static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
 765 {
 766         int i, len;
 767         struct mtd_dev_param *p;
 768         char buf[MTD_PARAM_LEN_MAX];
 769         char *pbuf = &buf[0];
 770         char *tokens[3] = {NULL, NULL, NULL};
 771
 772         if (mtd_devs == UBI_MAX_DEVICES) {
 773                 printk("UBI error: too many parameters, max. is %d\n",
 774                        UBI_MAX_DEVICES);
 775                 return -EINVAL;
 776         }
 777
 778         len = strnlen(val, MTD_PARAM_LEN_MAX);
 779         if (len == MTD_PARAM_LEN_MAX) {
 780                 printk("UBI error: parameter \"%s\" is too long, max. is %d\n",
 781                        val, MTD_PARAM_LEN_MAX);
 782                 return -EINVAL;
 783         }
 784
 785         if (len == 0) {
 786                 printk("UBI warning: empty 'mtd=' parameter - ignored\n");
 787                 return 0;
 788         }
 789
 790         strcpy(buf, val);
 791
 792         /* Get rid of the final newline */
 793         if (buf[len - 1] == '\n')
 794                 buf[len - 1] = '\0';
 795
 796         for (i = 0; i < 3; i++)
 797                 tokens[i] = strsep(&pbuf, ",");
 798
 799         if (pbuf) {
 800                 printk("UBI error: too many arguments at \"%s\"\n", val);
 801                 return -EINVAL;
 802         }
 803
 804         p = &mtd_dev_param[mtd_devs];
 805         strcpy(&p->name[0], tokens[0]);
 806
 807         if (tokens[1])
 808                 p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
 809         if (tokens[2])
 810                 p->data_offs = bytes_str_to_int(tokens[2]);
 811
 812         if (p->vid_hdr_offs < 0)
 813                 return p->vid_hdr_offs;
 814         if (p->data_offs < 0)
 815                 return p->data_offs;
 816
 817         mtd_devs += 1;
 818         return 0;
 819 }
 820
 821 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
 822 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
 823                       "mtd=<name|num>[,<vid_hdr_offs>,<data_offs>]. "
 824                       "Multiple \"mtd\" parameters may be specified.\n"
 825                       "MTD devices may be specified by their number or name. "
 826                       "Optional \"vid_hdr_offs\" and \"data_offs\" parameters "
 827                       "specify UBI VID header position and data starting "
 828                       "position to be used by UBI.\n"
 829                       "Example: mtd=content,1984,2048 mtd=4 - attach MTD device"
 830                       "with name content using VID header offset 1984 and data "
 831                       "start 2048, and MTD device number 4 using default "
 832                       "offsets");
 833
 834 MODULE_VERSION(__stringify(UBI_VERSION));
 835 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
 836 MODULE_AUTHOR("Artem Bityutskiy");
 837 MODULE_LICENSE("GPL");