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/namei.h>
  41#include <linux/stat.h>
  42#include <linux/miscdevice.h>
  43#include <linux/log2.h>
  44#include <linux/kthread.h>
  45#include <linux/kernel.h>
  46#include <linux/slab.h>
  47#include "ubi.h"
  48
  49/* Maximum length of the 'mtd=' parameter */
  50#define MTD_PARAM_LEN_MAX 64
  51
  52#ifdef CONFIG_MTD_UBI_MODULE
  53#define ubi_is_module() 1
  54#else
  55#define ubi_is_module() 0
  56#endif
  57
  58/**
  59 * struct mtd_dev_param - MTD device parameter description data structure.
  60 * @name: MTD character device node path, MTD device name, or MTD device number
  61 *        string
  62 * @vid_hdr_offs: VID header offset
  63 */
  64struct mtd_dev_param {
  65	char name[MTD_PARAM_LEN_MAX];
  66	int vid_hdr_offs;
  67};
  68
  69/* Numbers of elements set in the @mtd_dev_param array */
  70static int __initdata mtd_devs;
  71
  72/* MTD devices specification parameters */
  73static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
  74
  75/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
  76struct class *ubi_class;
  77
  78/* Slab cache for wear-leveling entries */
  79struct kmem_cache *ubi_wl_entry_slab;
  80
  81/* UBI control character device */
  82static struct miscdevice ubi_ctrl_cdev = {
  83	.minor = MISC_DYNAMIC_MINOR,
  84	.name = "ubi_ctrl",
  85	.fops = &ubi_ctrl_cdev_operations,
  86};
  87
  88/* All UBI devices in system */
  89static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
  90
  91/* Serializes UBI devices creations and removals */
  92DEFINE_MUTEX(ubi_devices_mutex);
  93
  94/* Protects @ubi_devices and @ubi->ref_count */
  95static DEFINE_SPINLOCK(ubi_devices_lock);
  96
  97/* "Show" method for files in '/<sysfs>/class/ubi/' */
  98static ssize_t ubi_version_show(struct class *class,
  99				struct class_attribute *attr, char *buf)
 100{
 101	return sprintf(buf, "%d\n", UBI_VERSION);
 102}
 103
 104/* UBI version attribute ('/<sysfs>/class/ubi/version') */
 105static struct class_attribute ubi_version =
 106	__ATTR(version, S_IRUGO, ubi_version_show, NULL);
 107
 108static ssize_t dev_attribute_show(struct device *dev,
 109				  struct device_attribute *attr, char *buf);
 110
 111/* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
 112static struct device_attribute dev_eraseblock_size =
 113	__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
 114static struct device_attribute dev_avail_eraseblocks =
 115	__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
 116static struct device_attribute dev_total_eraseblocks =
 117	__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
 118static struct device_attribute dev_volumes_count =
 119	__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
 120static struct device_attribute dev_max_ec =
 121	__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
 122static struct device_attribute dev_reserved_for_bad =
 123	__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
 124static struct device_attribute dev_bad_peb_count =
 125	__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
 126static struct device_attribute dev_max_vol_count =
 127	__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
 128static struct device_attribute dev_min_io_size =
 129	__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
 130static struct device_attribute dev_bgt_enabled =
 131	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
 132static struct device_attribute dev_mtd_num =
 133	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
 134
 135/**
 136 * ubi_volume_notify - send a volume change notification.
 137 * @ubi: UBI device description object
 138 * @vol: volume description object of the changed volume
 139 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
 140 *
 141 * This is a helper function which notifies all subscribers about a volume
 142 * change event (creation, removal, re-sizing, re-naming, updating). Returns
 143 * zero in case of success and a negative error code in case of failure.
 144 */
 145int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
 146{
 147	struct ubi_notification nt;
 148
 149	ubi_do_get_device_info(ubi, &nt.di);
 150	ubi_do_get_volume_info(ubi, vol, &nt.vi);
 151	return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
 152}
 153
 154/**
 155 * ubi_notify_all - send a notification to all volumes.
 156 * @ubi: UBI device description object
 157 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
 158 * @nb: the notifier to call
 159 *
 160 * This function walks all volumes of UBI device @ubi and sends the @ntype
 161 * notification for each volume. If @nb is %NULL, then all registered notifiers
 162 * are called, otherwise only the @nb notifier is called. Returns the number of
 163 * sent notifications.
 164 */
 165int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
 166{
 167	struct ubi_notification nt;
 168	int i, count = 0;
 169
 170	ubi_do_get_device_info(ubi, &nt.di);
 171
 172	mutex_lock(&ubi->device_mutex);
 173	for (i = 0; i < ubi->vtbl_slots; i++) {
 174		/*
 175		 * Since the @ubi->device is locked, and we are not going to
 176		 * change @ubi->volumes, we do not have to lock
 177		 * @ubi->volumes_lock.
 178		 */
 179		if (!ubi->volumes[i])
 180			continue;
 181
 182		ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
 183		if (nb)
 184			nb->notifier_call(nb, ntype, &nt);
 185		else
 186			blocking_notifier_call_chain(&ubi_notifiers, ntype,
 187						     &nt);
 188		count += 1;
 189	}
 190	mutex_unlock(&ubi->device_mutex);
 191
 192	return count;
 193}
 194
 195/**
 196 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
 197 * @nb: the notifier to call
 198 *
 199 * This function walks all UBI devices and volumes and sends the
 200 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
 201 * registered notifiers are called, otherwise only the @nb notifier is called.
 202 * Returns the number of sent notifications.
 203 */
 204int ubi_enumerate_volumes(struct notifier_block *nb)
 205{
 206	int i, count = 0;
 207
 208	/*
 209	 * Since the @ubi_devices_mutex is locked, and we are not going to
 210	 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
 211	 */
 212	for (i = 0; i < UBI_MAX_DEVICES; i++) {
 213		struct ubi_device *ubi = ubi_devices[i];
 214
 215		if (!ubi)
 216			continue;
 217		count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
 218	}
 219
 220	return count;
 221}
 222
 223/**
 224 * ubi_get_device - get UBI device.
 225 * @ubi_num: UBI device number
 226 *
 227 * This function returns UBI device description object for UBI device number
 228 * @ubi_num, or %NULL if the device does not exist. This function increases the
 229 * device reference count to prevent removal of the device. In other words, the
 230 * device cannot be removed if its reference count is not zero.
 231 */
 232struct ubi_device *ubi_get_device(int ubi_num)
 233{
 234	struct ubi_device *ubi;
 235
 236	spin_lock(&ubi_devices_lock);
 237	ubi = ubi_devices[ubi_num];
 238	if (ubi) {
 239		ubi_assert(ubi->ref_count >= 0);
 240		ubi->ref_count += 1;
 241		get_device(&ubi->dev);
 242	}
 243	spin_unlock(&ubi_devices_lock);
 244
 245	return ubi;
 246}
 247
 248/**
 249 * ubi_put_device - drop an UBI device reference.
 250 * @ubi: UBI device description object
 251 */
 252void ubi_put_device(struct ubi_device *ubi)
 253{
 254	spin_lock(&ubi_devices_lock);
 255	ubi->ref_count -= 1;
 256	put_device(&ubi->dev);
 257	spin_unlock(&ubi_devices_lock);
 258}
 259
 260/**
 261 * ubi_get_by_major - get UBI device by character device major number.
 262 * @major: major number
 263 *
 264 * This function is similar to 'ubi_get_device()', but it searches the device
 265 * by its major number.
 266 */
 267struct ubi_device *ubi_get_by_major(int major)
 268{
 269	int i;
 270	struct ubi_device *ubi;
 271
 272	spin_lock(&ubi_devices_lock);
 273	for (i = 0; i < UBI_MAX_DEVICES; i++) {
 274		ubi = ubi_devices[i];
 275		if (ubi && MAJOR(ubi->cdev.dev) == major) {
 276			ubi_assert(ubi->ref_count >= 0);
 277			ubi->ref_count += 1;
 278			get_device(&ubi->dev);
 279			spin_unlock(&ubi_devices_lock);
 280			return ubi;
 281		}
 282	}
 283	spin_unlock(&ubi_devices_lock);
 284
 285	return NULL;
 286}
 287
 288/**
 289 * ubi_major2num - get UBI device number by character device major number.
 290 * @major: major number
 291 *
 292 * This function searches UBI device number object by its major number. If UBI
 293 * device was not found, this function returns -ENODEV, otherwise the UBI device
 294 * number is returned.
 295 */
 296int ubi_major2num(int major)
 297{
 298	int i, ubi_num = -ENODEV;
 299
 300	spin_lock(&ubi_devices_lock);
 301	for (i = 0; i < UBI_MAX_DEVICES; i++) {
 302		struct ubi_device *ubi = ubi_devices[i];
 303
 304		if (ubi && MAJOR(ubi->cdev.dev) == major) {
 305			ubi_num = ubi->ubi_num;
 306			break;
 307		}
 308	}
 309	spin_unlock(&ubi_devices_lock);
 310
 311	return ubi_num;
 312}
 313
 314/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
 315static ssize_t dev_attribute_show(struct device *dev,
 316				  struct device_attribute *attr, char *buf)
 317{
 318	ssize_t ret;
 319	struct ubi_device *ubi;
 320
 321	/*
 322	 * The below code looks weird, but it actually makes sense. We get the
 323	 * UBI device reference from the contained 'struct ubi_device'. But it
 324	 * is unclear if the device was removed or not yet. Indeed, if the
 325	 * device was removed before we increased its reference count,
 326	 * 'ubi_get_device()' will return -ENODEV and we fail.
 327	 *
 328	 * Remember, 'struct ubi_device' is freed in the release function, so
 329	 * we still can use 'ubi->ubi_num'.
 330	 */
 331	ubi = container_of(dev, struct ubi_device, dev);
 332	ubi = ubi_get_device(ubi->ubi_num);
 333	if (!ubi)
 334		return -ENODEV;
 335
 336	if (attr == &dev_eraseblock_size)
 337		ret = sprintf(buf, "%d\n", ubi->leb_size);
 338	else if (attr == &dev_avail_eraseblocks)
 339		ret = sprintf(buf, "%d\n", ubi->avail_pebs);
 340	else if (attr == &dev_total_eraseblocks)
 341		ret = sprintf(buf, "%d\n", ubi->good_peb_count);
 342	else if (attr == &dev_volumes_count)
 343		ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
 344	else if (attr == &dev_max_ec)
 345		ret = sprintf(buf, "%d\n", ubi->max_ec);
 346	else if (attr == &dev_reserved_for_bad)
 347		ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
 348	else if (attr == &dev_bad_peb_count)
 349		ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
 350	else if (attr == &dev_max_vol_count)
 351		ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
 352	else if (attr == &dev_min_io_size)
 353		ret = sprintf(buf, "%d\n", ubi->min_io_size);
 354	else if (attr == &dev_bgt_enabled)
 355		ret = sprintf(buf, "%d\n", ubi->thread_enabled);
 356	else if (attr == &dev_mtd_num)
 357		ret = sprintf(buf, "%d\n", ubi->mtd->index);
 358	else
 359		ret = -EINVAL;
 360
 361	ubi_put_device(ubi);
 362	return ret;
 363}
 364
 365static void dev_release(struct device *dev)
 366{
 367	struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
 368
 369	kfree(ubi);
 370}
 371
 372/**
 373 * ubi_sysfs_init - initialize sysfs for an UBI device.
 374 * @ubi: UBI device description object
 375 * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
 376 *       taken
 377 *
 378 * This function returns zero in case of success and a negative error code in
 379 * case of failure.
 380 */
 381static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
 382{
 383	int err;
 384
 385	ubi->dev.release = dev_release;
 386	ubi->dev.devt = ubi->cdev.dev;
 387	ubi->dev.class = ubi_class;
 388	dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
 389	err = device_register(&ubi->dev);
 390	if (err)
 391		return err;
 392
 393	*ref = 1;
 394	err = device_create_file(&ubi->dev, &dev_eraseblock_size);
 395	if (err)
 396		return err;
 397	err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
 398	if (err)
 399		return err;
 400	err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
 401	if (err)
 402		return err;
 403	err = device_create_file(&ubi->dev, &dev_volumes_count);
 404	if (err)
 405		return err;
 406	err = device_create_file(&ubi->dev, &dev_max_ec);
 407	if (err)
 408		return err;
 409	err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
 410	if (err)
 411		return err;
 412	err = device_create_file(&ubi->dev, &dev_bad_peb_count);
 413	if (err)
 414		return err;
 415	err = device_create_file(&ubi->dev, &dev_max_vol_count);
 416	if (err)
 417		return err;
 418	err = device_create_file(&ubi->dev, &dev_min_io_size);
 419	if (err)
 420		return err;
 421	err = device_create_file(&ubi->dev, &dev_bgt_enabled);
 422	if (err)
 423		return err;
 424	err = device_create_file(&ubi->dev, &dev_mtd_num);
 425	return err;
 426}
 427
 428/**
 429 * ubi_sysfs_close - close sysfs for an UBI device.
 430 * @ubi: UBI device description object
 431 */
 432static void ubi_sysfs_close(struct ubi_device *ubi)
 433{
 434	device_remove_file(&ubi->dev, &dev_mtd_num);
 435	device_remove_file(&ubi->dev, &dev_bgt_enabled);
 436	device_remove_file(&ubi->dev, &dev_min_io_size);
 437	device_remove_file(&ubi->dev, &dev_max_vol_count);
 438	device_remove_file(&ubi->dev, &dev_bad_peb_count);
 439	device_remove_file(&ubi->dev, &dev_reserved_for_bad);
 440	device_remove_file(&ubi->dev, &dev_max_ec);
 441	device_remove_file(&ubi->dev, &dev_volumes_count);
 442	device_remove_file(&ubi->dev, &dev_total_eraseblocks);
 443	device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
 444	device_remove_file(&ubi->dev, &dev_eraseblock_size);
 445	device_unregister(&ubi->dev);
 446}
 447
 448/**
 449 * kill_volumes - destroy all user volumes.
 450 * @ubi: UBI device description object
 451 */
 452static void kill_volumes(struct ubi_device *ubi)
 453{
 454	int i;
 455
 456	for (i = 0; i < ubi->vtbl_slots; i++)
 457		if (ubi->volumes[i])
 458			ubi_free_volume(ubi, ubi->volumes[i]);
 459}
 460
 461/**
 462 * uif_init - initialize user interfaces for an UBI device.
 463 * @ubi: UBI device description object
 464 * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
 465 *       taken, otherwise set to %0
 466 *
 467 * This function initializes various user interfaces for an UBI device. If the
 468 * initialization fails at an early stage, this function frees all the
 469 * resources it allocated, returns an error, and @ref is set to %0. However,
 470 * if the initialization fails after the UBI device was registered in the
 471 * driver core subsystem, this function takes a reference to @ubi->dev, because
 472 * otherwise the release function ('dev_release()') would free whole @ubi
 473 * object. The @ref argument is set to %1 in this case. The caller has to put
 474 * this reference.
 475 *
 476 * This function returns zero in case of success and a negative error code in
 477 * case of failure.
 478 */
 479static int uif_init(struct ubi_device *ubi, int *ref)
 480{
 481	int i, err;
 482	dev_t dev;
 483
 484	*ref = 0;
 485	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
 486
 487	/*
 488	 * Major numbers for the UBI character devices are allocated
 489	 * dynamically. Major numbers of volume character devices are
 490	 * equivalent to ones of the corresponding UBI character device. Minor
 491	 * numbers of UBI character devices are 0, while minor numbers of
 492	 * volume character devices start from 1. Thus, we allocate one major
 493	 * number and ubi->vtbl_slots + 1 minor numbers.
 494	 */
 495	err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
 496	if (err) {
 497		ubi_err("cannot register UBI character devices");
 498		return err;
 499	}
 500
 501	ubi_assert(MINOR(dev) == 0);
 502	cdev_init(&ubi->cdev, &ubi_cdev_operations);
 503	dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
 504	ubi->cdev.owner = THIS_MODULE;
 505
 506	err = cdev_add(&ubi->cdev, dev, 1);
 507	if (err) {
 508		ubi_err("cannot add character device");
 509		goto out_unreg;
 510	}
 511
 512	err = ubi_sysfs_init(ubi, ref);
 513	if (err)
 514		goto out_sysfs;
 515
 516	for (i = 0; i < ubi->vtbl_slots; i++)
 517		if (ubi->volumes[i]) {
 518			err = ubi_add_volume(ubi, ubi->volumes[i]);
 519			if (err) {
 520				ubi_err("cannot add volume %d", i);
 521				goto out_volumes;
 522			}
 523		}
 524
 525	return 0;
 526
 527out_volumes:
 528	kill_volumes(ubi);
 529out_sysfs:
 530	if (*ref)
 531		get_device(&ubi->dev);
 532	ubi_sysfs_close(ubi);
 533	cdev_del(&ubi->cdev);
 534out_unreg:
 535	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
 536	ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
 537	return err;
 538}
 539
 540/**
 541 * uif_close - close user interfaces for an UBI device.
 542 * @ubi: UBI device description object
 543 *
 544 * Note, since this function un-registers UBI volume device objects (@vol->dev),
 545 * the memory allocated voe the volumes is freed as well (in the release
 546 * function).
 547 */
 548static void uif_close(struct ubi_device *ubi)
 549{
 550	kill_volumes(ubi);
 551	ubi_sysfs_close(ubi);
 552	cdev_del(&ubi->cdev);
 553	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
 554}
 555
 556/**
 557 * free_internal_volumes - free internal volumes.
 558 * @ubi: UBI device description object
 559 */
 560static void free_internal_volumes(struct ubi_device *ubi)
 561{
 562	int i;
 563
 564	for (i = ubi->vtbl_slots;
 565	     i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
 566		kfree(ubi->volumes[i]->eba_tbl);
 567		kfree(ubi->volumes[i]);
 568	}
 569}
 570
 571/**
 572 * attach_by_scanning - attach an MTD device using scanning method.
 573 * @ubi: UBI device descriptor
 574 *
 575 * This function returns zero in case of success and a negative error code in
 576 * case of failure.
 577 *
 578 * Note, currently this is the only method to attach UBI devices. Hopefully in
 579 * the future we'll have more scalable attaching methods and avoid full media
 580 * scanning. But even in this case scanning will be needed as a fall-back
 581 * attaching method if there are some on-flash table corruptions.
 582 */
 583static int attach_by_scanning(struct ubi_device *ubi)
 584{
 585	int err;
 586	struct ubi_scan_info *si;
 587
 588	si = ubi_scan(ubi);
 589	if (IS_ERR(si))
 590		return PTR_ERR(si);
 591
 592	ubi->bad_peb_count = si->bad_peb_count;
 593	ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
 594	ubi->corr_peb_count = si->corr_peb_count;
 595	ubi->max_ec = si->max_ec;
 596	ubi->mean_ec = si->mean_ec;
 597	ubi_msg("max. sequence number:       %llu", si->max_sqnum);
 598
 599	err = ubi_read_volume_table(ubi, si);
 600	if (err)
 601		goto out_si;
 602
 603	err = ubi_wl_init_scan(ubi, si);
 604	if (err)
 605		goto out_vtbl;
 606
 607	err = ubi_eba_init_scan(ubi, si);
 608	if (err)
 609		goto out_wl;
 610
 611	ubi_scan_destroy_si(si);
 612	return 0;
 613
 614out_wl:
 615	ubi_wl_close(ubi);
 616out_vtbl:
 617	free_internal_volumes(ubi);
 618	vfree(ubi->vtbl);
 619out_si:
 620	ubi_scan_destroy_si(si);
 621	return err;
 622}
 623
 624/**
 625 * io_init - initialize I/O sub-system for a given UBI device.
 626 * @ubi: UBI device description object
 627 *
 628 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
 629 * assumed:
 630 *   o EC header is always at offset zero - this cannot be changed;
 631 *   o VID header starts just after the EC header at the closest address
 632 *     aligned to @io->hdrs_min_io_size;
 633 *   o data starts just after the VID header at the closest address aligned to
 634 *     @io->min_io_size
 635 *
 636 * This function returns zero in case of success and a negative error code in
 637 * case of failure.
 638 */
 639static int io_init(struct ubi_device *ubi)
 640{
 641	if (ubi->mtd->numeraseregions != 0) {
 642		/*
 643		 * Some flashes have several erase regions. Different regions
 644		 * may have different eraseblock size and other
 645		 * characteristics. It looks like mostly multi-region flashes
 646		 * have one "main" region and one or more small regions to
 647		 * store boot loader code or boot parameters or whatever. I
 648		 * guess we should just pick the largest region. But this is
 649		 * not implemented.
 650		 */
 651		ubi_err("multiple regions, not implemented");
 652		return -EINVAL;
 653	}
 654
 655	if (ubi->vid_hdr_offset < 0)
 656		return -EINVAL;
 657
 658	/*
 659	 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
 660	 * physical eraseblocks maximum.
 661	 */
 662
 663	ubi->peb_size   = ubi->mtd->erasesize;
 664	ubi->peb_count  = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
 665	ubi->flash_size = ubi->mtd->size;
 666
 667	if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
 668		ubi->bad_allowed = 1;
 669
 670	if (ubi->mtd->type == MTD_NORFLASH) {
 671		ubi_assert(ubi->mtd->writesize == 1);
 672		ubi->nor_flash = 1;
 673	}
 674
 675	ubi->min_io_size = ubi->mtd->writesize;
 676	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
 677
 678	/*
 679	 * Make sure minimal I/O unit is power of 2. Note, there is no
 680	 * fundamental reason for this assumption. It is just an optimization
 681	 * which allows us to avoid costly division operations.
 682	 */
 683	if (!is_power_of_2(ubi->min_io_size)) {
 684		ubi_err("min. I/O unit (%d) is not power of 2",
 685			ubi->min_io_size);
 686		return -EINVAL;
 687	}
 688
 689	ubi_assert(ubi->hdrs_min_io_size > 0);
 690	ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
 691	ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
 692
 693	ubi->max_write_size = ubi->mtd->writebufsize;
 694	/*
 695	 * Maximum write size has to be greater or equivalent to min. I/O
 696	 * size, and be multiple of min. I/O size.
 697	 */
 698	if (ubi->max_write_size < ubi->min_io_size ||
 699	    ubi->max_write_size % ubi->min_io_size ||
 700	    !is_power_of_2(ubi->max_write_size)) {
 701		ubi_err("bad write buffer size %d for %d min. I/O unit",
 702			ubi->max_write_size, ubi->min_io_size);
 703		return -EINVAL;
 704	}
 705
 706	/* Calculate default aligned sizes of EC and VID headers */
 707	ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
 708	ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
 709
 710	dbg_msg("min_io_size      %d", ubi->min_io_size);
 711	dbg_msg("max_write_size   %d", ubi->max_write_size);
 712	dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
 713	dbg_msg("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
 714	dbg_msg("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
 715
 716	if (ubi->vid_hdr_offset == 0)
 717		/* Default offset */
 718		ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
 719				      ubi->ec_hdr_alsize;
 720	else {
 721		ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
 722						~(ubi->hdrs_min_io_size - 1);
 723		ubi->vid_hdr_shift = ubi->vid_hdr_offset -
 724						ubi->vid_hdr_aloffset;
 725	}
 726
 727	/* Similar for the data offset */
 728	ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
 729	ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
 730
 731	dbg_msg("vid_hdr_offset   %d", ubi->vid_hdr_offset);
 732	dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
 733	dbg_msg("vid_hdr_shift    %d", ubi->vid_hdr_shift);
 734	dbg_msg("leb_start        %d", ubi->leb_start);
 735
 736	/* The shift must be aligned to 32-bit boundary */
 737	if (ubi->vid_hdr_shift % 4) {
 738		ubi_err("unaligned VID header shift %d",
 739			ubi->vid_hdr_shift);
 740		return -EINVAL;
 741	}
 742
 743	/* Check sanity */
 744	if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
 745	    ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
 746	    ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
 747	    ubi->leb_start & (ubi->min_io_size - 1)) {
 748		ubi_err("bad VID header (%d) or data offsets (%d)",
 749			ubi->vid_hdr_offset, ubi->leb_start);
 750		return -EINVAL;
 751	}
 752
 753	/*
 754	 * Set maximum amount of physical erroneous eraseblocks to be 10%.
 755	 * Erroneous PEB are those which have read errors.
 756	 */
 757	ubi->max_erroneous = ubi->peb_count / 10;
 758	if (ubi->max_erroneous < 16)
 759		ubi->max_erroneous = 16;
 760	dbg_msg("max_erroneous    %d", ubi->max_erroneous);
 761
 762	/*
 763	 * It may happen that EC and VID headers are situated in one minimal
 764	 * I/O unit. In this case we can only accept this UBI image in
 765	 * read-only mode.
 766	 */
 767	if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
 768		ubi_warn("EC and VID headers are in the same minimal I/O unit, "
 769			 "switch to read-only mode");
 770		ubi->ro_mode = 1;
 771	}
 772
 773	ubi->leb_size = ubi->peb_size - ubi->leb_start;
 774
 775	if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
 776		ubi_msg("MTD device %d is write-protected, attach in "
 777			"read-only mode", ubi->mtd->index);
 778		ubi->ro_mode = 1;
 779	}
 780
 781	ubi_msg("physical eraseblock size:   %d bytes (%d KiB)",
 782		ubi->peb_size, ubi->peb_size >> 10);
 783	ubi_msg("logical eraseblock size:    %d bytes", ubi->leb_size);
 784	ubi_msg("smallest flash I/O unit:    %d", ubi->min_io_size);
 785	if (ubi->hdrs_min_io_size != ubi->min_io_size)
 786		ubi_msg("sub-page size:              %d",
 787			ubi->hdrs_min_io_size);
 788	ubi_msg("VID header offset:          %d (aligned %d)",
 789		ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
 790	ubi_msg("data offset:                %d", ubi->leb_start);
 791
 792	/*
 793	 * Note, ideally, we have to initialize ubi->bad_peb_count here. But
 794	 * unfortunately, MTD does not provide this information. We should loop
 795	 * over all physical eraseblocks and invoke mtd->block_is_bad() for
 796	 * each physical eraseblock. So, we skip ubi->bad_peb_count
 797	 * uninitialized and initialize it after scanning.
 798	 */
 799
 800	return 0;
 801}
 802
 803/**
 804 * autoresize - re-size the volume which has the "auto-resize" flag set.
 805 * @ubi: UBI device description object
 806 * @vol_id: ID of the volume to re-size
 807 *
 808 * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
 809 * the volume table to the largest possible size. See comments in ubi-header.h
 810 * for more description of the flag. Returns zero in case of success and a
 811 * negative error code in case of failure.
 812 */
 813static int autoresize(struct ubi_device *ubi, int vol_id)
 814{
 815	struct ubi_volume_desc desc;
 816	struct ubi_volume *vol = ubi->volumes[vol_id];
 817	int err, old_reserved_pebs = vol->reserved_pebs;
 818
 
 
 
 
 
 819	/*
 820	 * Clear the auto-resize flag in the volume in-memory copy of the
 821	 * volume table, and 'ubi_resize_volume()' will propagate this change
 822	 * to the flash.
 823	 */
 824	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
 825
 826	if (ubi->avail_pebs == 0) {
 827		struct ubi_vtbl_record vtbl_rec;
 828
 829		/*
 830		 * No available PEBs to re-size the volume, clear the flag on
 831		 * flash and exit.
 832		 */
 833		memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
 834		       sizeof(struct ubi_vtbl_record));
 835		err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
 836		if (err)
 837			ubi_err("cannot clean auto-resize flag for volume %d",
 838				vol_id);
 839	} else {
 840		desc.vol = vol;
 841		err = ubi_resize_volume(&desc,
 842					old_reserved_pebs + ubi->avail_pebs);
 843		if (err)
 844			ubi_err("cannot auto-resize volume %d", vol_id);
 845	}
 846
 847	if (err)
 848		return err;
 849
 850	ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
 851		vol->name, old_reserved_pebs, vol->reserved_pebs);
 852	return 0;
 853}
 854
 855/**
 856 * ubi_attach_mtd_dev - attach an MTD device.
 857 * @mtd: MTD device description object
 858 * @ubi_num: number to assign to the new UBI device
 859 * @vid_hdr_offset: VID header offset
 860 *
 861 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
 862 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
 863 * which case this function finds a vacant device number and assigns it
 864 * automatically. Returns the new UBI device number in case of success and a
 865 * negative error code in case of failure.
 866 *
 867 * Note, the invocations of this function has to be serialized by the
 868 * @ubi_devices_mutex.
 869 */
 870int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
 871{
 872	struct ubi_device *ubi;
 873	int i, err, ref = 0;
 874
 875	/*
 876	 * Check if we already have the same MTD device attached.
 877	 *
 878	 * Note, this function assumes that UBI devices creations and deletions
 879	 * are serialized, so it does not take the &ubi_devices_lock.
 880	 */
 881	for (i = 0; i < UBI_MAX_DEVICES; i++) {
 882		ubi = ubi_devices[i];
 883		if (ubi && mtd->index == ubi->mtd->index) {
 884			dbg_err("mtd%d is already attached to ubi%d",
 885				mtd->index, i);
 886			return -EEXIST;
 887		}
 888	}
 889
 890	/*
 891	 * Make sure this MTD device is not emulated on top of an UBI volume
 892	 * already. Well, generally this recursion works fine, but there are
 893	 * different problems like the UBI module takes a reference to itself
 894	 * by attaching (and thus, opening) the emulated MTD device. This
 895	 * results in inability to unload the module. And in general it makes
 896	 * no sense to attach emulated MTD devices, so we prohibit this.
 897	 */
 898	if (mtd->type == MTD_UBIVOLUME) {
 899		ubi_err("refuse attaching mtd%d - it is already emulated on "
 900			"top of UBI", mtd->index);
 901		return -EINVAL;
 902	}
 903
 904	if (ubi_num == UBI_DEV_NUM_AUTO) {
 905		/* Search for an empty slot in the @ubi_devices array */
 906		for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
 907			if (!ubi_devices[ubi_num])
 908				break;
 909		if (ubi_num == UBI_MAX_DEVICES) {
 910			dbg_err("only %d UBI devices may be created",
 911				UBI_MAX_DEVICES);
 912			return -ENFILE;
 913		}
 914	} else {
 915		if (ubi_num >= UBI_MAX_DEVICES)
 916			return -EINVAL;
 917
 918		/* Make sure ubi_num is not busy */
 919		if (ubi_devices[ubi_num]) {
 920			dbg_err("ubi%d already exists", ubi_num);
 921			return -EEXIST;
 922		}
 923	}
 924
 925	ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
 926	if (!ubi)
 927		return -ENOMEM;
 928
 929	ubi->mtd = mtd;
 930	ubi->ubi_num = ubi_num;
 931	ubi->vid_hdr_offset = vid_hdr_offset;
 932	ubi->autoresize_vol_id = -1;
 933
 934	mutex_init(&ubi->buf_mutex);
 935	mutex_init(&ubi->ckvol_mutex);
 936	mutex_init(&ubi->device_mutex);
 937	spin_lock_init(&ubi->volumes_lock);
 938
 939	ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
 940	dbg_msg("sizeof(struct ubi_scan_leb) %zu", sizeof(struct ubi_scan_leb));
 941	dbg_msg("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
 942
 943	err = io_init(ubi);
 944	if (err)
 945		goto out_free;
 946
 947	err = -ENOMEM;
 948	ubi->peb_buf1 = vmalloc(ubi->peb_size);
 949	if (!ubi->peb_buf1)
 950		goto out_free;
 951
 952	ubi->peb_buf2 = vmalloc(ubi->peb_size);
 953	if (!ubi->peb_buf2)
 954		goto out_free;
 955
 956	err = ubi_debugging_init_dev(ubi);
 957	if (err)
 958		goto out_free;
 959
 960	err = attach_by_scanning(ubi);
 961	if (err) {
 962		dbg_err("failed to attach by scanning, error %d", err);
 963		goto out_debugging;
 964	}
 965
 966	if (ubi->autoresize_vol_id != -1) {
 967		err = autoresize(ubi, ubi->autoresize_vol_id);
 968		if (err)
 969			goto out_detach;
 970	}
 971
 972	err = uif_init(ubi, &ref);
 973	if (err)
 974		goto out_detach;
 975
 976	err = ubi_debugfs_init_dev(ubi);
 977	if (err)
 978		goto out_uif;
 979
 980	ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
 981	if (IS_ERR(ubi->bgt_thread)) {
 982		err = PTR_ERR(ubi->bgt_thread);
 983		ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
 984			err);
 985		goto out_debugfs;
 986	}
 987
 988	ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
 989	ubi_msg("MTD device name:            \"%s\"", mtd->name);
 990	ubi_msg("MTD device size:            %llu MiB", ubi->flash_size >> 20);
 991	ubi_msg("number of good PEBs:        %d", ubi->good_peb_count);
 992	ubi_msg("number of bad PEBs:         %d", ubi->bad_peb_count);
 993	ubi_msg("number of corrupted PEBs:   %d", ubi->corr_peb_count);
 994	ubi_msg("max. allowed volumes:       %d", ubi->vtbl_slots);
 995	ubi_msg("wear-leveling threshold:    %d", CONFIG_MTD_UBI_WL_THRESHOLD);
 996	ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
 997	ubi_msg("number of user volumes:     %d",
 998		ubi->vol_count - UBI_INT_VOL_COUNT);
 999	ubi_msg("available PEBs:             %d", ubi->avail_pebs);
1000	ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
1001	ubi_msg("number of PEBs reserved for bad PEB handling: %d",
1002		ubi->beb_rsvd_pebs);
1003	ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
1004	ubi_msg("image sequence number:  %d", ubi->image_seq);
1005
1006	/*
1007	 * The below lock makes sure we do not race with 'ubi_thread()' which
1008	 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1009	 */
1010	spin_lock(&ubi->wl_lock);
1011	ubi->thread_enabled = 1;
1012	wake_up_process(ubi->bgt_thread);
1013	spin_unlock(&ubi->wl_lock);
1014
1015	ubi_devices[ubi_num] = ubi;
1016	ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1017	return ubi_num;
1018
1019out_debugfs:
1020	ubi_debugfs_exit_dev(ubi);
1021out_uif:
1022	get_device(&ubi->dev);
1023	ubi_assert(ref);
1024	uif_close(ubi);
1025out_detach:
1026	ubi_wl_close(ubi);
1027	free_internal_volumes(ubi);
1028	vfree(ubi->vtbl);
1029out_debugging:
1030	ubi_debugging_exit_dev(ubi);
1031out_free:
1032	vfree(ubi->peb_buf1);
1033	vfree(ubi->peb_buf2);
1034	if (ref)
1035		put_device(&ubi->dev);
1036	else
1037		kfree(ubi);
1038	return err;
1039}
1040
1041/**
1042 * ubi_detach_mtd_dev - detach an MTD device.
1043 * @ubi_num: UBI device number to detach from
1044 * @anyway: detach MTD even if device reference count is not zero
1045 *
1046 * This function destroys an UBI device number @ubi_num and detaches the
1047 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1048 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1049 * exist.
1050 *
1051 * Note, the invocations of this function has to be serialized by the
1052 * @ubi_devices_mutex.
1053 */
1054int ubi_detach_mtd_dev(int ubi_num, int anyway)
1055{
1056	struct ubi_device *ubi;
1057
1058	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1059		return -EINVAL;
1060
1061	ubi = ubi_get_device(ubi_num);
1062	if (!ubi)
1063		return -EINVAL;
1064
1065	spin_lock(&ubi_devices_lock);
1066	put_device(&ubi->dev);
1067	ubi->ref_count -= 1;
1068	if (ubi->ref_count) {
1069		if (!anyway) {
1070			spin_unlock(&ubi_devices_lock);
1071			return -EBUSY;
1072		}
1073		/* This may only happen if there is a bug */
1074		ubi_err("%s reference count %d, destroy anyway",
1075			ubi->ubi_name, ubi->ref_count);
1076	}
1077	ubi_devices[ubi_num] = NULL;
1078	spin_unlock(&ubi_devices_lock);
1079
1080	ubi_assert(ubi_num == ubi->ubi_num);
1081	ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1082	dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
1083
1084	/*
1085	 * Before freeing anything, we have to stop the background thread to
1086	 * prevent it from doing anything on this device while we are freeing.
1087	 */
1088	if (ubi->bgt_thread)
1089		kthread_stop(ubi->bgt_thread);
1090
1091	/*
1092	 * Get a reference to the device in order to prevent 'dev_release()'
1093	 * from freeing the @ubi object.
1094	 */
1095	get_device(&ubi->dev);
1096
1097	ubi_debugfs_exit_dev(ubi);
1098	uif_close(ubi);
1099	ubi_wl_close(ubi);
1100	free_internal_volumes(ubi);
1101	vfree(ubi->vtbl);
1102	put_mtd_device(ubi->mtd);
1103	ubi_debugging_exit_dev(ubi);
1104	vfree(ubi->peb_buf1);
1105	vfree(ubi->peb_buf2);
1106	ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
1107	put_device(&ubi->dev);
1108	return 0;
1109}
1110
1111/**
1112 * open_mtd_by_chdev - open an MTD device by its character device node path.
1113 * @mtd_dev: MTD character device node path
1114 *
1115 * This helper function opens an MTD device by its character node device path.
1116 * Returns MTD device description object in case of success and a negative
1117 * error code in case of failure.
1118 */
1119static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1120{
1121	int err, major, minor, mode;
1122	struct path path;
1123
1124	/* Probably this is an MTD character device node path */
1125	err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1126	if (err)
1127		return ERR_PTR(err);
1128
1129	/* MTD device number is defined by the major / minor numbers */
1130	major = imajor(path.dentry->d_inode);
1131	minor = iminor(path.dentry->d_inode);
1132	mode = path.dentry->d_inode->i_mode;
1133	path_put(&path);
1134	if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))
1135		return ERR_PTR(-EINVAL);
1136
1137	if (minor & 1)
1138		/*
1139		 * Just do not think the "/dev/mtdrX" devices support is need,
1140		 * so do not support them to avoid doing extra work.
1141		 */
1142		return ERR_PTR(-EINVAL);
1143
1144	return get_mtd_device(NULL, minor / 2);
1145}
1146
1147/**
1148 * open_mtd_device - open MTD device by name, character device path, or number.
1149 * @mtd_dev: name, character device node path, or MTD device device number
1150 *
1151 * This function tries to open and MTD device described by @mtd_dev string,
1152 * which is first treated as ASCII MTD device number, and if it is not true, it
1153 * is treated as MTD device name, and if that is also not true, it is treated
1154 * as MTD character device node path. Returns MTD device description object in
1155 * case of success and a negative error code in case of failure.
1156 */
1157static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1158{
1159	struct mtd_info *mtd;
1160	int mtd_num;
1161	char *endp;
1162
1163	mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1164	if (*endp != '\0' || mtd_dev == endp) {
1165		/*
1166		 * This does not look like an ASCII integer, probably this is
1167		 * MTD device name.
1168		 */
1169		mtd = get_mtd_device_nm(mtd_dev);
1170		if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV)
1171			/* Probably this is an MTD character device node path */
1172			mtd = open_mtd_by_chdev(mtd_dev);
1173	} else
1174		mtd = get_mtd_device(NULL, mtd_num);
1175
1176	return mtd;
1177}
1178
1179static int __init ubi_init(void)
1180{
1181	int err, i, k;
1182
1183	/* Ensure that EC and VID headers have correct size */
1184	BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1185	BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1186
1187	if (mtd_devs > UBI_MAX_DEVICES) {
1188		ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
1189		return -EINVAL;
1190	}
1191
1192	/* Create base sysfs directory and sysfs files */
1193	ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
1194	if (IS_ERR(ubi_class)) {
1195		err = PTR_ERR(ubi_class);
1196		ubi_err("cannot create UBI class");
1197		goto out;
1198	}
1199
1200	err = class_create_file(ubi_class, &ubi_version);
1201	if (err) {
1202		ubi_err("cannot create sysfs file");
1203		goto out_class;
1204	}
1205
1206	err = misc_register(&ubi_ctrl_cdev);
1207	if (err) {
1208		ubi_err("cannot register device");
1209		goto out_version;
1210	}
1211
1212	ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1213					      sizeof(struct ubi_wl_entry),
1214					      0, 0, NULL);
1215	if (!ubi_wl_entry_slab)
1216		goto out_dev_unreg;
1217
1218	err = ubi_debugfs_init();
1219	if (err)
1220		goto out_slab;
1221
1222
1223	/* Attach MTD devices */
1224	for (i = 0; i < mtd_devs; i++) {
1225		struct mtd_dev_param *p = &mtd_dev_param[i];
1226		struct mtd_info *mtd;
1227
1228		cond_resched();
1229
1230		mtd = open_mtd_device(p->name);
1231		if (IS_ERR(mtd)) {
1232			err = PTR_ERR(mtd);
1233			goto out_detach;
1234		}
1235
1236		mutex_lock(&ubi_devices_mutex);
1237		err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
1238					 p->vid_hdr_offs);
1239		mutex_unlock(&ubi_devices_mutex);
1240		if (err < 0) {
1241			ubi_err("cannot attach mtd%d", mtd->index);
1242			put_mtd_device(mtd);
1243
1244			/*
1245			 * Originally UBI stopped initializing on any error.
1246			 * However, later on it was found out that this
1247			 * behavior is not very good when UBI is compiled into
1248			 * the kernel and the MTD devices to attach are passed
1249			 * through the command line. Indeed, UBI failure
1250			 * stopped whole boot sequence.
1251			 *
1252			 * To fix this, we changed the behavior for the
1253			 * non-module case, but preserved the old behavior for
1254			 * the module case, just for compatibility. This is a
1255			 * little inconsistent, though.
1256			 */
1257			if (ubi_is_module())
1258				goto out_detach;
1259		}
1260	}
1261
1262	return 0;
1263
1264out_detach:
1265	for (k = 0; k < i; k++)
1266		if (ubi_devices[k]) {
1267			mutex_lock(&ubi_devices_mutex);
1268			ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1269			mutex_unlock(&ubi_devices_mutex);
1270		}
1271	ubi_debugfs_exit();
1272out_slab:
1273	kmem_cache_destroy(ubi_wl_entry_slab);
1274out_dev_unreg:
1275	misc_deregister(&ubi_ctrl_cdev);
1276out_version:
1277	class_remove_file(ubi_class, &ubi_version);
1278out_class:
1279	class_destroy(ubi_class);
1280out:
1281	ubi_err("UBI error: cannot initialize UBI, error %d", err);
1282	return err;
1283}
1284module_init(ubi_init);
1285
1286static void __exit ubi_exit(void)
1287{
1288	int i;
1289
1290	for (i = 0; i < UBI_MAX_DEVICES; i++)
1291		if (ubi_devices[i]) {
1292			mutex_lock(&ubi_devices_mutex);
1293			ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1294			mutex_unlock(&ubi_devices_mutex);
1295		}
1296	ubi_debugfs_exit();
1297	kmem_cache_destroy(ubi_wl_entry_slab);
1298	misc_deregister(&ubi_ctrl_cdev);
1299	class_remove_file(ubi_class, &ubi_version);
1300	class_destroy(ubi_class);
1301}
1302module_exit(ubi_exit);
1303
1304/**
1305 * bytes_str_to_int - convert a number of bytes string into an integer.
1306 * @str: the string to convert
1307 *
1308 * This function returns positive resulting integer in case of success and a
1309 * negative error code in case of failure.
1310 */
1311static int __init bytes_str_to_int(const char *str)
1312{
1313	char *endp;
1314	unsigned long result;
1315
1316	result = simple_strtoul(str, &endp, 0);
1317	if (str == endp || result >= INT_MAX) {
1318		printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1319		       str);
1320		return -EINVAL;
1321	}
1322
1323	switch (*endp) {
1324	case 'G':
1325		result *= 1024;
1326	case 'M':
1327		result *= 1024;
1328	case 'K':
1329		result *= 1024;
1330		if (endp[1] == 'i' && endp[2] == 'B')
1331			endp += 2;
1332	case '\0':
1333		break;
1334	default:
1335		printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1336		       str);
1337		return -EINVAL;
1338	}
1339
1340	return result;
1341}
1342
1343/**
1344 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1345 * @val: the parameter value to parse
1346 * @kp: not used
1347 *
1348 * This function returns zero in case of success and a negative error code in
1349 * case of error.
1350 */
1351static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1352{
1353	int i, len;
1354	struct mtd_dev_param *p;
1355	char buf[MTD_PARAM_LEN_MAX];
1356	char *pbuf = &buf[0];
1357	char *tokens[2] = {NULL, NULL};
1358
1359	if (!val)
1360		return -EINVAL;
1361
1362	if (mtd_devs == UBI_MAX_DEVICES) {
1363		printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
1364		       UBI_MAX_DEVICES);
1365		return -EINVAL;
1366	}
1367
1368	len = strnlen(val, MTD_PARAM_LEN_MAX);
1369	if (len == MTD_PARAM_LEN_MAX) {
1370		printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
1371		       "max. is %d\n", val, MTD_PARAM_LEN_MAX);
1372		return -EINVAL;
1373	}
1374
1375	if (len == 0) {
1376		printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
1377		       "ignored\n");
1378		return 0;
1379	}
1380
1381	strcpy(buf, val);
1382
1383	/* Get rid of the final newline */
1384	if (buf[len - 1] == '\n')
1385		buf[len - 1] = '\0';
1386
1387	for (i = 0; i < 2; i++)
1388		tokens[i] = strsep(&pbuf, ",");
1389
1390	if (pbuf) {
1391		printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
1392		       val);
1393		return -EINVAL;
1394	}
1395
1396	p = &mtd_dev_param[mtd_devs];
1397	strcpy(&p->name[0], tokens[0]);
1398
1399	if (tokens[1])
1400		p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
1401
1402	if (p->vid_hdr_offs < 0)
1403		return p->vid_hdr_offs;
1404
1405	mtd_devs += 1;
1406	return 0;
1407}
1408
1409module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1410MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
1411		      "mtd=<name|num|path>[,<vid_hdr_offs>].\n"
1412		      "Multiple \"mtd\" parameters may be specified.\n"
1413		      "MTD devices may be specified by their number, name, or "
1414		      "path to the MTD character device node.\n"
1415		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
1416		      "header position to be used by UBI.\n"
1417		      "Example 1: mtd=/dev/mtd0 - attach MTD device "
1418		      "/dev/mtd0.\n"
1419		      "Example 2: mtd=content,1984 mtd=4 - attach MTD device "
1420		      "with name \"content\" using VID header offset 1984, and "
1421		      "MTD device number 4 with default VID header offset.");
1422
1423MODULE_VERSION(__stringify(UBI_VERSION));
1424MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1425MODULE_AUTHOR("Artem Bityutskiy");
1426MODULE_LICENSE("GPL");