1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (c) International Business Machines Corp., 2006
   4 * Copyright (c) Nokia Corporation, 2007
   5 *
   6 * Author: Artem Bityutskiy (Битюцкий Артём),
   7 *         Frank Haverkamp
   8 */
   9
  10/*
  11 * This file includes UBI initialization and building of UBI devices.
  12 *
  13 * When UBI is initialized, it attaches all the MTD devices specified as the
  14 * module load parameters or the kernel boot parameters. If MTD devices were
  15 * specified, UBI does not attach any MTD device, but it is possible to do
  16 * later using the "UBI control device".
  17 */
  18
  19#include <linux/err.h>
  20#include <linux/module.h>
  21#include <linux/moduleparam.h>
  22#include <linux/stringify.h>
  23#include <linux/namei.h>
  24#include <linux/stat.h>
  25#include <linux/miscdevice.h>
  26#include <linux/mtd/partitions.h>
  27#include <linux/log2.h>
  28#include <linux/kthread.h>
  29#include <linux/kernel.h>
  30#include <linux/slab.h>
  31#include <linux/major.h>
  32#include "ubi.h"
  33
  34/* Maximum length of the 'mtd=' parameter */
  35#define MTD_PARAM_LEN_MAX 64
  36
  37/* Maximum number of comma-separated items in the 'mtd=' parameter */
  38#define MTD_PARAM_MAX_COUNT 4
  39
  40/* Maximum value for the number of bad PEBs per 1024 PEBs */
  41#define MAX_MTD_UBI_BEB_LIMIT 768
  42
  43#ifdef CONFIG_MTD_UBI_MODULE
  44#define ubi_is_module() 1
  45#else
  46#define ubi_is_module() 0
  47#endif
  48
  49/**
  50 * struct mtd_dev_param - MTD device parameter description data structure.
  51 * @name: MTD character device node path, MTD device name, or MTD device number
  52 *        string
  53 * @ubi_num: UBI number
  54 * @vid_hdr_offs: VID header offset
  55 * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
  56 */
  57struct mtd_dev_param {
  58	char name[MTD_PARAM_LEN_MAX];
  59	int ubi_num;
  60	int vid_hdr_offs;
  61	int max_beb_per1024;
  62};
  63
  64/* Numbers of elements set in the @mtd_dev_param array */
  65static int mtd_devs;
  66
  67/* MTD devices specification parameters */
  68static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
  69#ifdef CONFIG_MTD_UBI_FASTMAP
  70/* UBI module parameter to enable fastmap automatically on non-fastmap images */
  71static bool fm_autoconvert;
  72static bool fm_debug;
  73#endif
  74
  75/* Slab cache for wear-leveling entries */
  76struct kmem_cache *ubi_wl_entry_slab;
  77
  78/* UBI control character device */
  79static struct miscdevice ubi_ctrl_cdev = {
  80	.minor = MISC_DYNAMIC_MINOR,
  81	.name = "ubi_ctrl",
  82	.fops = &ubi_ctrl_cdev_operations,
  83};
  84
  85/* All UBI devices in system */
  86static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
  87
  88/* Serializes UBI devices creations and removals */
  89DEFINE_MUTEX(ubi_devices_mutex);
  90
  91/* Protects @ubi_devices and @ubi->ref_count */
  92static DEFINE_SPINLOCK(ubi_devices_lock);
  93
  94/* "Show" method for files in '/<sysfs>/class/ubi/' */
  95/* UBI version attribute ('/<sysfs>/class/ubi/version') */
  96static ssize_t version_show(struct class *class, struct class_attribute *attr,
  97			    char *buf)
  98{
  99	return sprintf(buf, "%d\n", UBI_VERSION);
 100}
 101static CLASS_ATTR_RO(version);
 102
 103static struct attribute *ubi_class_attrs[] = {
 104	&class_attr_version.attr,
 105	NULL,
 106};
 107ATTRIBUTE_GROUPS(ubi_class);
 108
 109/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
 110struct class ubi_class = {
 111	.name		= UBI_NAME_STR,
 112	.owner		= THIS_MODULE,
 113	.class_groups	= ubi_class_groups,
 114};
 115
 116static ssize_t dev_attribute_show(struct device *dev,
 117				  struct device_attribute *attr, char *buf);
 118
 119/* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
 120static struct device_attribute dev_eraseblock_size =
 121	__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
 122static struct device_attribute dev_avail_eraseblocks =
 123	__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
 124static struct device_attribute dev_total_eraseblocks =
 125	__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
 126static struct device_attribute dev_volumes_count =
 127	__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
 128static struct device_attribute dev_max_ec =
 129	__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
 130static struct device_attribute dev_reserved_for_bad =
 131	__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
 132static struct device_attribute dev_bad_peb_count =
 133	__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
 134static struct device_attribute dev_max_vol_count =
 135	__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
 136static struct device_attribute dev_min_io_size =
 137	__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
 138static struct device_attribute dev_bgt_enabled =
 139	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
 140static struct device_attribute dev_mtd_num =
 141	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
 142static struct device_attribute dev_ro_mode =
 143	__ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
 144
 145/**
 146 * ubi_volume_notify - send a volume change notification.
 147 * @ubi: UBI device description object
 148 * @vol: volume description object of the changed volume
 149 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
 150 *
 151 * This is a helper function which notifies all subscribers about a volume
 152 * change event (creation, removal, re-sizing, re-naming, updating). Returns
 153 * zero in case of success and a negative error code in case of failure.
 154 */
 155int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
 156{
 157	int ret;
 158	struct ubi_notification nt;
 159
 160	ubi_do_get_device_info(ubi, &nt.di);
 161	ubi_do_get_volume_info(ubi, vol, &nt.vi);
 162
 163	switch (ntype) {
 164	case UBI_VOLUME_ADDED:
 165	case UBI_VOLUME_REMOVED:
 166	case UBI_VOLUME_RESIZED:
 167	case UBI_VOLUME_RENAMED:
 168		ret = ubi_update_fastmap(ubi);
 169		if (ret)
 170			ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
 171	}
 172
 173	return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
 174}
 175
 176/**
 177 * ubi_notify_all - send a notification to all volumes.
 178 * @ubi: UBI device description object
 179 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
 180 * @nb: the notifier to call
 181 *
 182 * This function walks all volumes of UBI device @ubi and sends the @ntype
 183 * notification for each volume. If @nb is %NULL, then all registered notifiers
 184 * are called, otherwise only the @nb notifier is called. Returns the number of
 185 * sent notifications.
 186 */
 187int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
 188{
 189	struct ubi_notification nt;
 190	int i, count = 0;
 191
 192	ubi_do_get_device_info(ubi, &nt.di);
 193
 194	mutex_lock(&ubi->device_mutex);
 195	for (i = 0; i < ubi->vtbl_slots; i++) {
 196		/*
 197		 * Since the @ubi->device is locked, and we are not going to
 198		 * change @ubi->volumes, we do not have to lock
 199		 * @ubi->volumes_lock.
 200		 */
 201		if (!ubi->volumes[i])
 202			continue;
 203
 204		ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
 205		if (nb)
 206			nb->notifier_call(nb, ntype, &nt);
 207		else
 208			blocking_notifier_call_chain(&ubi_notifiers, ntype,
 209						     &nt);
 210		count += 1;
 211	}
 212	mutex_unlock(&ubi->device_mutex);
 213
 214	return count;
 215}
 216
 217/**
 218 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
 219 * @nb: the notifier to call
 220 *
 221 * This function walks all UBI devices and volumes and sends the
 222 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
 223 * registered notifiers are called, otherwise only the @nb notifier is called.
 224 * Returns the number of sent notifications.
 225 */
 226int ubi_enumerate_volumes(struct notifier_block *nb)
 227{
 228	int i, count = 0;
 229
 230	/*
 231	 * Since the @ubi_devices_mutex is locked, and we are not going to
 232	 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
 233	 */
 234	for (i = 0; i < UBI_MAX_DEVICES; i++) {
 235		struct ubi_device *ubi = ubi_devices[i];
 236
 237		if (!ubi)
 238			continue;
 239		count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
 240	}
 241
 242	return count;
 243}
 244
 245/**
 246 * ubi_get_device - get UBI device.
 247 * @ubi_num: UBI device number
 248 *
 249 * This function returns UBI device description object for UBI device number
 250 * @ubi_num, or %NULL if the device does not exist. This function increases the
 251 * device reference count to prevent removal of the device. In other words, the
 252 * device cannot be removed if its reference count is not zero.
 253 */
 254struct ubi_device *ubi_get_device(int ubi_num)
 255{
 256	struct ubi_device *ubi;
 257
 258	spin_lock(&ubi_devices_lock);
 259	ubi = ubi_devices[ubi_num];
 260	if (ubi) {
 261		ubi_assert(ubi->ref_count >= 0);
 262		ubi->ref_count += 1;
 263		get_device(&ubi->dev);
 264	}
 265	spin_unlock(&ubi_devices_lock);
 266
 267	return ubi;
 268}
 269
 270/**
 271 * ubi_put_device - drop an UBI device reference.
 272 * @ubi: UBI device description object
 273 */
 274void ubi_put_device(struct ubi_device *ubi)
 275{
 276	spin_lock(&ubi_devices_lock);
 277	ubi->ref_count -= 1;
 278	put_device(&ubi->dev);
 279	spin_unlock(&ubi_devices_lock);
 280}
 281
 282/**
 283 * ubi_get_by_major - get UBI device by character device major number.
 284 * @major: major number
 285 *
 286 * This function is similar to 'ubi_get_device()', but it searches the device
 287 * by its major number.
 288 */
 289struct ubi_device *ubi_get_by_major(int major)
 290{
 291	int i;
 292	struct ubi_device *ubi;
 293
 294	spin_lock(&ubi_devices_lock);
 295	for (i = 0; i < UBI_MAX_DEVICES; i++) {
 296		ubi = ubi_devices[i];
 297		if (ubi && MAJOR(ubi->cdev.dev) == major) {
 298			ubi_assert(ubi->ref_count >= 0);
 299			ubi->ref_count += 1;
 300			get_device(&ubi->dev);
 301			spin_unlock(&ubi_devices_lock);
 302			return ubi;
 303		}
 304	}
 305	spin_unlock(&ubi_devices_lock);
 306
 307	return NULL;
 308}
 309
 310/**
 311 * ubi_major2num - get UBI device number by character device major number.
 312 * @major: major number
 313 *
 314 * This function searches UBI device number object by its major number. If UBI
 315 * device was not found, this function returns -ENODEV, otherwise the UBI device
 316 * number is returned.
 317 */
 318int ubi_major2num(int major)
 319{
 320	int i, ubi_num = -ENODEV;
 321
 322	spin_lock(&ubi_devices_lock);
 323	for (i = 0; i < UBI_MAX_DEVICES; i++) {
 324		struct ubi_device *ubi = ubi_devices[i];
 325
 326		if (ubi && MAJOR(ubi->cdev.dev) == major) {
 327			ubi_num = ubi->ubi_num;
 328			break;
 329		}
 330	}
 331	spin_unlock(&ubi_devices_lock);
 332
 333	return ubi_num;
 334}
 335
 336/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
 337static ssize_t dev_attribute_show(struct device *dev,
 338				  struct device_attribute *attr, char *buf)
 339{
 340	ssize_t ret;
 341	struct ubi_device *ubi;
 342
 343	/*
 344	 * The below code looks weird, but it actually makes sense. We get the
 345	 * UBI device reference from the contained 'struct ubi_device'. But it
 346	 * is unclear if the device was removed or not yet. Indeed, if the
 347	 * device was removed before we increased its reference count,
 348	 * 'ubi_get_device()' will return -ENODEV and we fail.
 349	 *
 350	 * Remember, 'struct ubi_device' is freed in the release function, so
 351	 * we still can use 'ubi->ubi_num'.
 352	 */
 353	ubi = container_of(dev, struct ubi_device, dev);
 
 
 
 354
 355	if (attr == &dev_eraseblock_size)
 356		ret = sprintf(buf, "%d\n", ubi->leb_size);
 357	else if (attr == &dev_avail_eraseblocks)
 358		ret = sprintf(buf, "%d\n", ubi->avail_pebs);
 359	else if (attr == &dev_total_eraseblocks)
 360		ret = sprintf(buf, "%d\n", ubi->good_peb_count);
 361	else if (attr == &dev_volumes_count)
 362		ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
 363	else if (attr == &dev_max_ec)
 364		ret = sprintf(buf, "%d\n", ubi->max_ec);
 365	else if (attr == &dev_reserved_for_bad)
 366		ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
 367	else if (attr == &dev_bad_peb_count)
 368		ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
 369	else if (attr == &dev_max_vol_count)
 370		ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
 371	else if (attr == &dev_min_io_size)
 372		ret = sprintf(buf, "%d\n", ubi->min_io_size);
 373	else if (attr == &dev_bgt_enabled)
 374		ret = sprintf(buf, "%d\n", ubi->thread_enabled);
 375	else if (attr == &dev_mtd_num)
 376		ret = sprintf(buf, "%d\n", ubi->mtd->index);
 377	else if (attr == &dev_ro_mode)
 378		ret = sprintf(buf, "%d\n", ubi->ro_mode);
 379	else
 380		ret = -EINVAL;
 381
 
 382	return ret;
 383}
 384
 385static struct attribute *ubi_dev_attrs[] = {
 386	&dev_eraseblock_size.attr,
 387	&dev_avail_eraseblocks.attr,
 388	&dev_total_eraseblocks.attr,
 389	&dev_volumes_count.attr,
 390	&dev_max_ec.attr,
 391	&dev_reserved_for_bad.attr,
 392	&dev_bad_peb_count.attr,
 393	&dev_max_vol_count.attr,
 394	&dev_min_io_size.attr,
 395	&dev_bgt_enabled.attr,
 396	&dev_mtd_num.attr,
 397	&dev_ro_mode.attr,
 398	NULL
 399};
 400ATTRIBUTE_GROUPS(ubi_dev);
 401
 402static void dev_release(struct device *dev)
 403{
 404	struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
 405
 406	kfree(ubi);
 407}
 408
 409/**
 410 * kill_volumes - destroy all user volumes.
 411 * @ubi: UBI device description object
 412 */
 413static void kill_volumes(struct ubi_device *ubi)
 414{
 415	int i;
 416
 417	for (i = 0; i < ubi->vtbl_slots; i++)
 418		if (ubi->volumes[i])
 419			ubi_free_volume(ubi, ubi->volumes[i]);
 420}
 421
 422/**
 423 * uif_init - initialize user interfaces for an UBI device.
 424 * @ubi: UBI device description object
 425 *
 426 * This function initializes various user interfaces for an UBI device. If the
 427 * initialization fails at an early stage, this function frees all the
 428 * resources it allocated, returns an error.
 429 *
 430 * This function returns zero in case of success and a negative error code in
 431 * case of failure.
 432 */
 433static int uif_init(struct ubi_device *ubi)
 434{
 435	int i, err;
 436	dev_t dev;
 437
 438	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
 439
 440	/*
 441	 * Major numbers for the UBI character devices are allocated
 442	 * dynamically. Major numbers of volume character devices are
 443	 * equivalent to ones of the corresponding UBI character device. Minor
 444	 * numbers of UBI character devices are 0, while minor numbers of
 445	 * volume character devices start from 1. Thus, we allocate one major
 446	 * number and ubi->vtbl_slots + 1 minor numbers.
 447	 */
 448	err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
 449	if (err) {
 450		ubi_err(ubi, "cannot register UBI character devices");
 451		return err;
 452	}
 453
 454	ubi->dev.devt = dev;
 455
 456	ubi_assert(MINOR(dev) == 0);
 457	cdev_init(&ubi->cdev, &ubi_cdev_operations);
 458	dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
 459	ubi->cdev.owner = THIS_MODULE;
 460
 461	dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
 462	err = cdev_device_add(&ubi->cdev, &ubi->dev);
 463	if (err)
 464		goto out_unreg;
 465
 466	for (i = 0; i < ubi->vtbl_slots; i++)
 467		if (ubi->volumes[i]) {
 468			err = ubi_add_volume(ubi, ubi->volumes[i]);
 469			if (err) {
 470				ubi_err(ubi, "cannot add volume %d", i);
 471				goto out_volumes;
 472			}
 473		}
 474
 475	return 0;
 476
 477out_volumes:
 478	kill_volumes(ubi);
 479	cdev_device_del(&ubi->cdev, &ubi->dev);
 480out_unreg:
 481	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
 482	ubi_err(ubi, "cannot initialize UBI %s, error %d",
 483		ubi->ubi_name, err);
 484	return err;
 485}
 486
 487/**
 488 * uif_close - close user interfaces for an UBI device.
 489 * @ubi: UBI device description object
 490 *
 491 * Note, since this function un-registers UBI volume device objects (@vol->dev),
 492 * the memory allocated voe the volumes is freed as well (in the release
 493 * function).
 494 */
 495static void uif_close(struct ubi_device *ubi)
 496{
 497	kill_volumes(ubi);
 498	cdev_device_del(&ubi->cdev, &ubi->dev);
 499	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
 500}
 501
 502/**
 503 * ubi_free_volumes_from - free volumes from specific index.
 504 * @ubi: UBI device description object
 505 * @from: the start index used for volume free.
 506 */
 507static void ubi_free_volumes_from(struct ubi_device *ubi, int from)
 508{
 509	int i;
 510
 511	for (i = from; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
 512		if (!ubi->volumes[i])
 513			continue;
 514		ubi_eba_replace_table(ubi->volumes[i], NULL);
 515		ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
 516		kfree(ubi->volumes[i]);
 517		ubi->volumes[i] = NULL;
 518	}
 519}
 520
 521/**
 522 * ubi_free_all_volumes - free all volumes.
 523 * @ubi: UBI device description object
 524 */
 525void ubi_free_all_volumes(struct ubi_device *ubi)
 526{
 527	ubi_free_volumes_from(ubi, 0);
 528}
 529
 530/**
 531 * ubi_free_internal_volumes - free internal volumes.
 532 * @ubi: UBI device description object
 533 */
 534void ubi_free_internal_volumes(struct ubi_device *ubi)
 535{
 536	ubi_free_volumes_from(ubi, ubi->vtbl_slots);
 537}
 538
 539static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
 540{
 541	int limit, device_pebs;
 542	uint64_t device_size;
 543
 544	if (!max_beb_per1024) {
 545		/*
 546		 * Since max_beb_per1024 has not been set by the user in either
 547		 * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
 548		 * limit if it is supported by the device.
 549		 */
 550		limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
 551		if (limit < 0)
 552			return 0;
 553		return limit;
 554	}
 555
 556	/*
 557	 * Here we are using size of the entire flash chip and
 558	 * not just the MTD partition size because the maximum
 559	 * number of bad eraseblocks is a percentage of the
 560	 * whole device and bad eraseblocks are not fairly
 561	 * distributed over the flash chip. So the worst case
 562	 * is that all the bad eraseblocks of the chip are in
 563	 * the MTD partition we are attaching (ubi->mtd).
 564	 */
 565	device_size = mtd_get_device_size(ubi->mtd);
 566	device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
 567	limit = mult_frac(device_pebs, max_beb_per1024, 1024);
 568
 569	/* Round it up */
 570	if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
 571		limit += 1;
 572
 573	return limit;
 574}
 575
 576/**
 577 * io_init - initialize I/O sub-system for a given UBI device.
 578 * @ubi: UBI device description object
 579 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
 580 *
 581 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
 582 * assumed:
 583 *   o EC header is always at offset zero - this cannot be changed;
 584 *   o VID header starts just after the EC header at the closest address
 585 *     aligned to @io->hdrs_min_io_size;
 586 *   o data starts just after the VID header at the closest address aligned to
 587 *     @io->min_io_size
 588 *
 589 * This function returns zero in case of success and a negative error code in
 590 * case of failure.
 591 */
 592static int io_init(struct ubi_device *ubi, int max_beb_per1024)
 593{
 594	dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
 595	dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
 596
 597	if (ubi->mtd->numeraseregions != 0) {
 598		/*
 599		 * Some flashes have several erase regions. Different regions
 600		 * may have different eraseblock size and other
 601		 * characteristics. It looks like mostly multi-region flashes
 602		 * have one "main" region and one or more small regions to
 603		 * store boot loader code or boot parameters or whatever. I
 604		 * guess we should just pick the largest region. But this is
 605		 * not implemented.
 606		 */
 607		ubi_err(ubi, "multiple regions, not implemented");
 608		return -EINVAL;
 609	}
 610
 611	if (ubi->vid_hdr_offset < 0)
 612		return -EINVAL;
 613
 614	/*
 615	 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
 616	 * physical eraseblocks maximum.
 617	 */
 618
 619	ubi->peb_size   = ubi->mtd->erasesize;
 620	ubi->peb_count  = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
 621	ubi->flash_size = ubi->mtd->size;
 622
 623	if (mtd_can_have_bb(ubi->mtd)) {
 624		ubi->bad_allowed = 1;
 625		ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
 626	}
 627
 628	if (ubi->mtd->type == MTD_NORFLASH)
 629		ubi->nor_flash = 1;
 630
 631	ubi->min_io_size = ubi->mtd->writesize;
 632	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
 633
 634	/*
 635	 * Make sure minimal I/O unit is power of 2. Note, there is no
 636	 * fundamental reason for this assumption. It is just an optimization
 637	 * which allows us to avoid costly division operations.
 638	 */
 639	if (!is_power_of_2(ubi->min_io_size)) {
 640		ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
 641			ubi->min_io_size);
 642		return -EINVAL;
 643	}
 644
 645	ubi_assert(ubi->hdrs_min_io_size > 0);
 646	ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
 647	ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
 648
 649	ubi->max_write_size = ubi->mtd->writebufsize;
 650	/*
 651	 * Maximum write size has to be greater or equivalent to min. I/O
 652	 * size, and be multiple of min. I/O size.
 653	 */
 654	if (ubi->max_write_size < ubi->min_io_size ||
 655	    ubi->max_write_size % ubi->min_io_size ||
 656	    !is_power_of_2(ubi->max_write_size)) {
 657		ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
 658			ubi->max_write_size, ubi->min_io_size);
 659		return -EINVAL;
 660	}
 661
 662	/* Calculate default aligned sizes of EC and VID headers */
 663	ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
 664	ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
 665
 666	dbg_gen("min_io_size      %d", ubi->min_io_size);
 667	dbg_gen("max_write_size   %d", ubi->max_write_size);
 668	dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
 669	dbg_gen("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
 670	dbg_gen("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
 671
 672	if (ubi->vid_hdr_offset == 0)
 673		/* Default offset */
 674		ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
 675				      ubi->ec_hdr_alsize;
 676	else {
 677		ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
 678						~(ubi->hdrs_min_io_size - 1);
 679		ubi->vid_hdr_shift = ubi->vid_hdr_offset -
 680						ubi->vid_hdr_aloffset;
 681	}
 682
 683	/* Similar for the data offset */
 684	ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
 685	ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
 686
 687	dbg_gen("vid_hdr_offset   %d", ubi->vid_hdr_offset);
 688	dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
 689	dbg_gen("vid_hdr_shift    %d", ubi->vid_hdr_shift);
 690	dbg_gen("leb_start        %d", ubi->leb_start);
 691
 692	/* The shift must be aligned to 32-bit boundary */
 693	if (ubi->vid_hdr_shift % 4) {
 694		ubi_err(ubi, "unaligned VID header shift %d",
 695			ubi->vid_hdr_shift);
 696		return -EINVAL;
 697	}
 698
 699	/* Check sanity */
 700	if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
 701	    ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
 702	    ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
 703	    ubi->leb_start & (ubi->min_io_size - 1)) {
 704		ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
 705			ubi->vid_hdr_offset, ubi->leb_start);
 706		return -EINVAL;
 707	}
 708
 709	/*
 710	 * Set maximum amount of physical erroneous eraseblocks to be 10%.
 711	 * Erroneous PEB are those which have read errors.
 712	 */
 713	ubi->max_erroneous = ubi->peb_count / 10;
 714	if (ubi->max_erroneous < 16)
 715		ubi->max_erroneous = 16;
 716	dbg_gen("max_erroneous    %d", ubi->max_erroneous);
 717
 718	/*
 719	 * It may happen that EC and VID headers are situated in one minimal
 720	 * I/O unit. In this case we can only accept this UBI image in
 721	 * read-only mode.
 722	 */
 723	if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
 724		ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
 725		ubi->ro_mode = 1;
 726	}
 727
 728	ubi->leb_size = ubi->peb_size - ubi->leb_start;
 729
 730	if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
 731		ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
 732			ubi->mtd->index);
 733		ubi->ro_mode = 1;
 734	}
 735
 736	/*
 737	 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
 738	 * unfortunately, MTD does not provide this information. We should loop
 739	 * over all physical eraseblocks and invoke mtd->block_is_bad() for
 740	 * each physical eraseblock. So, we leave @ubi->bad_peb_count
 741	 * uninitialized so far.
 742	 */
 743
 744	return 0;
 745}
 746
 747/**
 748 * autoresize - re-size the volume which has the "auto-resize" flag set.
 749 * @ubi: UBI device description object
 750 * @vol_id: ID of the volume to re-size
 751 *
 752 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
 753 * the volume table to the largest possible size. See comments in ubi-header.h
 754 * for more description of the flag. Returns zero in case of success and a
 755 * negative error code in case of failure.
 756 */
 757static int autoresize(struct ubi_device *ubi, int vol_id)
 758{
 759	struct ubi_volume_desc desc;
 760	struct ubi_volume *vol = ubi->volumes[vol_id];
 761	int err, old_reserved_pebs = vol->reserved_pebs;
 762
 763	if (ubi->ro_mode) {
 764		ubi_warn(ubi, "skip auto-resize because of R/O mode");
 765		return 0;
 766	}
 767
 768	/*
 769	 * Clear the auto-resize flag in the volume in-memory copy of the
 770	 * volume table, and 'ubi_resize_volume()' will propagate this change
 771	 * to the flash.
 772	 */
 773	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
 774
 775	if (ubi->avail_pebs == 0) {
 776		struct ubi_vtbl_record vtbl_rec;
 777
 778		/*
 779		 * No available PEBs to re-size the volume, clear the flag on
 780		 * flash and exit.
 781		 */
 782		vtbl_rec = ubi->vtbl[vol_id];
 783		err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
 784		if (err)
 785			ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
 786				vol_id);
 787	} else {
 788		desc.vol = vol;
 789		err = ubi_resize_volume(&desc,
 790					old_reserved_pebs + ubi->avail_pebs);
 791		if (err)
 792			ubi_err(ubi, "cannot auto-resize volume %d",
 793				vol_id);
 794	}
 795
 796	if (err)
 797		return err;
 798
 799	ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
 800		vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
 801	return 0;
 802}
 803
 804/**
 805 * ubi_attach_mtd_dev - attach an MTD device.
 806 * @mtd: MTD device description object
 807 * @ubi_num: number to assign to the new UBI device
 808 * @vid_hdr_offset: VID header offset
 809 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
 810 * @disable_fm: whether disable fastmap
 811 *
 812 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
 813 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
 814 * which case this function finds a vacant device number and assigns it
 815 * automatically. Returns the new UBI device number in case of success and a
 816 * negative error code in case of failure.
 817 *
 818 * If @disable_fm is true, ubi doesn't create new fastmap even the module param
 819 * 'fm_autoconvert' is set, and existed old fastmap will be destroyed after
 820 * doing full scanning.
 821 *
 822 * Note, the invocations of this function has to be serialized by the
 823 * @ubi_devices_mutex.
 824 */
 825int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
 826		       int vid_hdr_offset, int max_beb_per1024, bool disable_fm)
 827{
 828	struct ubi_device *ubi;
 829	int i, err;
 830
 831	if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
 832		return -EINVAL;
 833
 834	if (!max_beb_per1024)
 835		max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
 836
 837	/*
 838	 * Check if we already have the same MTD device attached.
 839	 *
 840	 * Note, this function assumes that UBI devices creations and deletions
 841	 * are serialized, so it does not take the &ubi_devices_lock.
 842	 */
 843	for (i = 0; i < UBI_MAX_DEVICES; i++) {
 844		ubi = ubi_devices[i];
 845		if (ubi && mtd->index == ubi->mtd->index) {
 846			pr_err("ubi: mtd%d is already attached to ubi%d\n",
 847				mtd->index, i);
 848			return -EEXIST;
 849		}
 850	}
 851
 852	/*
 853	 * Make sure this MTD device is not emulated on top of an UBI volume
 854	 * already. Well, generally this recursion works fine, but there are
 855	 * different problems like the UBI module takes a reference to itself
 856	 * by attaching (and thus, opening) the emulated MTD device. This
 857	 * results in inability to unload the module. And in general it makes
 858	 * no sense to attach emulated MTD devices, so we prohibit this.
 859	 */
 860	if (mtd->type == MTD_UBIVOLUME) {
 861		pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
 862			mtd->index);
 863		return -EINVAL;
 864	}
 865
 866	/*
 867	 * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
 868	 * MLC NAND is different and needs special care, otherwise UBI or UBIFS
 869	 * will die soon and you will lose all your data.
 870	 * Relax this rule if the partition we're attaching to operates in SLC
 871	 * mode.
 872	 */
 873	if (mtd->type == MTD_MLCNANDFLASH &&
 874	    !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
 875		pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
 876			mtd->index);
 877		return -EINVAL;
 878	}
 879
 880	if (ubi_num == UBI_DEV_NUM_AUTO) {
 881		/* Search for an empty slot in the @ubi_devices array */
 882		for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
 883			if (!ubi_devices[ubi_num])
 884				break;
 885		if (ubi_num == UBI_MAX_DEVICES) {
 886			pr_err("ubi: only %d UBI devices may be created\n",
 887				UBI_MAX_DEVICES);
 888			return -ENFILE;
 889		}
 890	} else {
 891		if (ubi_num >= UBI_MAX_DEVICES)
 892			return -EINVAL;
 893
 894		/* Make sure ubi_num is not busy */
 895		if (ubi_devices[ubi_num]) {
 896			pr_err("ubi: ubi%i already exists\n", ubi_num);
 897			return -EEXIST;
 898		}
 899	}
 900
 901	ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
 902	if (!ubi)
 903		return -ENOMEM;
 904
 905	device_initialize(&ubi->dev);
 906	ubi->dev.release = dev_release;
 907	ubi->dev.class = &ubi_class;
 908	ubi->dev.groups = ubi_dev_groups;
 909
 910	ubi->mtd = mtd;
 911	ubi->ubi_num = ubi_num;
 912	ubi->vid_hdr_offset = vid_hdr_offset;
 913	ubi->autoresize_vol_id = -1;
 914
 915#ifdef CONFIG_MTD_UBI_FASTMAP
 916	ubi->fm_pool.used = ubi->fm_pool.size = 0;
 917	ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
 918
 919	/*
 920	 * fm_pool.max_size is 5% of the total number of PEBs but it's also
 921	 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
 922	 */
 923	ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
 924		ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
 925	ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
 926		UBI_FM_MIN_POOL_SIZE);
 927
 928	ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
 929	ubi->fm_disabled = (!fm_autoconvert || disable_fm) ? 1 : 0;
 930	if (fm_debug)
 931		ubi_enable_dbg_chk_fastmap(ubi);
 932
 933	if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
 934	    <= UBI_FM_MAX_START) {
 935		ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
 936			UBI_FM_MAX_START);
 937		ubi->fm_disabled = 1;
 938	}
 939
 940	ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
 941	ubi_msg(ubi, "default fastmap WL pool size: %d",
 942		ubi->fm_wl_pool.max_size);
 943#else
 944	ubi->fm_disabled = 1;
 945#endif
 946	mutex_init(&ubi->buf_mutex);
 947	mutex_init(&ubi->ckvol_mutex);
 948	mutex_init(&ubi->device_mutex);
 949	spin_lock_init(&ubi->volumes_lock);
 950	init_rwsem(&ubi->fm_protect);
 951	init_rwsem(&ubi->fm_eba_sem);
 952
 953	ubi_msg(ubi, "attaching mtd%d", mtd->index);
 954
 955	err = io_init(ubi, max_beb_per1024);
 956	if (err)
 957		goto out_free;
 958
 959	err = -ENOMEM;
 960	ubi->peb_buf = vmalloc(ubi->peb_size);
 961	if (!ubi->peb_buf)
 962		goto out_free;
 963
 964#ifdef CONFIG_MTD_UBI_FASTMAP
 965	ubi->fm_size = ubi_calc_fm_size(ubi);
 966	ubi->fm_buf = vzalloc(ubi->fm_size);
 967	if (!ubi->fm_buf)
 968		goto out_free;
 969#endif
 970	err = ubi_attach(ubi, disable_fm ? 1 : 0);
 971	if (err) {
 972		ubi_err(ubi, "failed to attach mtd%d, error %d",
 973			mtd->index, err);
 974		goto out_free;
 975	}
 976
 977	if (ubi->autoresize_vol_id != -1) {
 978		err = autoresize(ubi, ubi->autoresize_vol_id);
 979		if (err)
 980			goto out_detach;
 981	}
 982
 
 
 
 983	err = uif_init(ubi);
 984	if (err)
 985		goto out_detach;
 986
 987	err = ubi_debugfs_init_dev(ubi);
 988	if (err)
 989		goto out_uif;
 990
 991	ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
 992	if (IS_ERR(ubi->bgt_thread)) {
 993		err = PTR_ERR(ubi->bgt_thread);
 994		ubi_err(ubi, "cannot spawn \"%s\", error %d",
 995			ubi->bgt_name, err);
 996		goto out_debugfs;
 997	}
 998
 999	ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
1000		mtd->index, mtd->name, ubi->flash_size >> 20);
1001	ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
1002		ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
1003	ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
1004		ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1005	ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1006		ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1007	ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1008		ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1009	ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1010		ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1011		ubi->vtbl_slots);
1012	ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1013		ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1014		ubi->image_seq);
1015	ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1016		ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1017
1018	/*
1019	 * The below lock makes sure we do not race with 'ubi_thread()' which
1020	 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1021	 */
1022	spin_lock(&ubi->wl_lock);
1023	ubi->thread_enabled = 1;
1024	wake_up_process(ubi->bgt_thread);
1025	spin_unlock(&ubi->wl_lock);
1026
1027	ubi_devices[ubi_num] = ubi;
1028	ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1029	return ubi_num;
1030
1031out_debugfs:
1032	ubi_debugfs_exit_dev(ubi);
1033out_uif:
1034	uif_close(ubi);
1035out_detach:
 
1036	ubi_wl_close(ubi);
1037	ubi_free_all_volumes(ubi);
1038	vfree(ubi->vtbl);
1039out_free:
1040	vfree(ubi->peb_buf);
1041	vfree(ubi->fm_buf);
1042	put_device(&ubi->dev);
1043	return err;
1044}
1045
1046/**
1047 * ubi_detach_mtd_dev - detach an MTD device.
1048 * @ubi_num: UBI device number to detach from
1049 * @anyway: detach MTD even if device reference count is not zero
1050 *
1051 * This function destroys an UBI device number @ubi_num and detaches the
1052 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1053 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1054 * exist.
1055 *
1056 * Note, the invocations of this function has to be serialized by the
1057 * @ubi_devices_mutex.
1058 */
1059int ubi_detach_mtd_dev(int ubi_num, int anyway)
1060{
1061	struct ubi_device *ubi;
1062
1063	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1064		return -EINVAL;
1065
1066	ubi = ubi_get_device(ubi_num);
1067	if (!ubi)
1068		return -EINVAL;
1069
1070	spin_lock(&ubi_devices_lock);
1071	put_device(&ubi->dev);
1072	ubi->ref_count -= 1;
1073	if (ubi->ref_count) {
1074		if (!anyway) {
1075			spin_unlock(&ubi_devices_lock);
1076			return -EBUSY;
1077		}
1078		/* This may only happen if there is a bug */
1079		ubi_err(ubi, "%s reference count %d, destroy anyway",
1080			ubi->ubi_name, ubi->ref_count);
1081	}
1082	ubi_devices[ubi_num] = NULL;
1083	spin_unlock(&ubi_devices_lock);
1084
1085	ubi_assert(ubi_num == ubi->ubi_num);
1086	ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1087	ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1088#ifdef CONFIG_MTD_UBI_FASTMAP
1089	/* If we don't write a new fastmap at detach time we lose all
1090	 * EC updates that have been made since the last written fastmap.
1091	 * In case of fastmap debugging we omit the update to simulate an
1092	 * unclean shutdown. */
1093	if (!ubi_dbg_chk_fastmap(ubi))
1094		ubi_update_fastmap(ubi);
1095#endif
1096	/*
1097	 * Before freeing anything, we have to stop the background thread to
1098	 * prevent it from doing anything on this device while we are freeing.
1099	 */
1100	if (ubi->bgt_thread)
1101		kthread_stop(ubi->bgt_thread);
1102
1103#ifdef CONFIG_MTD_UBI_FASTMAP
1104	cancel_work_sync(&ubi->fm_work);
1105#endif
1106	ubi_debugfs_exit_dev(ubi);
1107	uif_close(ubi);
1108
1109	ubi_wl_close(ubi);
1110	ubi_free_internal_volumes(ubi);
1111	vfree(ubi->vtbl);
1112	vfree(ubi->peb_buf);
1113	vfree(ubi->fm_buf);
1114	ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1115	put_mtd_device(ubi->mtd);
1116	put_device(&ubi->dev);
1117	return 0;
1118}
1119
1120/**
1121 * open_mtd_by_chdev - open an MTD device by its character device node path.
1122 * @mtd_dev: MTD character device node path
1123 *
1124 * This helper function opens an MTD device by its character node device path.
1125 * Returns MTD device description object in case of success and a negative
1126 * error code in case of failure.
1127 */
1128static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1129{
1130	int err, minor;
1131	struct path path;
1132	struct kstat stat;
1133
1134	/* Probably this is an MTD character device node path */
1135	err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1136	if (err)
1137		return ERR_PTR(err);
1138
1139	err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1140	path_put(&path);
1141	if (err)
1142		return ERR_PTR(err);
1143
1144	/* MTD device number is defined by the major / minor numbers */
1145	if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1146		return ERR_PTR(-EINVAL);
1147
1148	minor = MINOR(stat.rdev);
1149
1150	if (minor & 1)
1151		/*
1152		 * Just do not think the "/dev/mtdrX" devices support is need,
1153		 * so do not support them to avoid doing extra work.
1154		 */
1155		return ERR_PTR(-EINVAL);
1156
1157	return get_mtd_device(NULL, minor / 2);
1158}
1159
1160/**
1161 * open_mtd_device - open MTD device by name, character device path, or number.
1162 * @mtd_dev: name, character device node path, or MTD device device number
1163 *
1164 * This function tries to open and MTD device described by @mtd_dev string,
1165 * which is first treated as ASCII MTD device number, and if it is not true, it
1166 * is treated as MTD device name, and if that is also not true, it is treated
1167 * as MTD character device node path. Returns MTD device description object in
1168 * case of success and a negative error code in case of failure.
1169 */
1170static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1171{
1172	struct mtd_info *mtd;
1173	int mtd_num;
1174	char *endp;
1175
1176	mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1177	if (*endp != '\0' || mtd_dev == endp) {
1178		/*
1179		 * This does not look like an ASCII integer, probably this is
1180		 * MTD device name.
1181		 */
1182		mtd = get_mtd_device_nm(mtd_dev);
1183		if (PTR_ERR(mtd) == -ENODEV)
1184			/* Probably this is an MTD character device node path */
1185			mtd = open_mtd_by_chdev(mtd_dev);
1186	} else
1187		mtd = get_mtd_device(NULL, mtd_num);
1188
1189	return mtd;
1190}
1191
1192static int __init ubi_init(void)
1193{
1194	int err, i, k;
1195
1196	/* Ensure that EC and VID headers have correct size */
1197	BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1198	BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1199
1200	if (mtd_devs > UBI_MAX_DEVICES) {
1201		pr_err("UBI error: too many MTD devices, maximum is %d\n",
1202		       UBI_MAX_DEVICES);
1203		return -EINVAL;
1204	}
1205
1206	/* Create base sysfs directory and sysfs files */
1207	err = class_register(&ubi_class);
1208	if (err < 0)
1209		return err;
1210
1211	err = misc_register(&ubi_ctrl_cdev);
1212	if (err) {
1213		pr_err("UBI error: cannot register device\n");
1214		goto out;
1215	}
1216
1217	ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1218					      sizeof(struct ubi_wl_entry),
1219					      0, 0, NULL);
1220	if (!ubi_wl_entry_slab) {
1221		err = -ENOMEM;
1222		goto out_dev_unreg;
1223	}
1224
1225	err = ubi_debugfs_init();
1226	if (err)
1227		goto out_slab;
1228
1229
1230	/* Attach MTD devices */
1231	for (i = 0; i < mtd_devs; i++) {
1232		struct mtd_dev_param *p = &mtd_dev_param[i];
1233		struct mtd_info *mtd;
1234
1235		cond_resched();
1236
1237		mtd = open_mtd_device(p->name);
1238		if (IS_ERR(mtd)) {
1239			err = PTR_ERR(mtd);
1240			pr_err("UBI error: cannot open mtd %s, error %d\n",
1241			       p->name, err);
1242			/* See comment below re-ubi_is_module(). */
1243			if (ubi_is_module())
1244				goto out_detach;
1245			continue;
1246		}
1247
1248		mutex_lock(&ubi_devices_mutex);
1249		err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1250					 p->vid_hdr_offs, p->max_beb_per1024,
1251					 false);
1252		mutex_unlock(&ubi_devices_mutex);
1253		if (err < 0) {
1254			pr_err("UBI error: cannot attach mtd%d\n",
1255			       mtd->index);
1256			put_mtd_device(mtd);
1257
1258			/*
1259			 * Originally UBI stopped initializing on any error.
1260			 * However, later on it was found out that this
1261			 * behavior is not very good when UBI is compiled into
1262			 * the kernel and the MTD devices to attach are passed
1263			 * through the command line. Indeed, UBI failure
1264			 * stopped whole boot sequence.
1265			 *
1266			 * To fix this, we changed the behavior for the
1267			 * non-module case, but preserved the old behavior for
1268			 * the module case, just for compatibility. This is a
1269			 * little inconsistent, though.
1270			 */
1271			if (ubi_is_module())
1272				goto out_detach;
1273		}
1274	}
1275
1276	err = ubiblock_init();
1277	if (err) {
1278		pr_err("UBI error: block: cannot initialize, error %d\n", err);
1279
1280		/* See comment above re-ubi_is_module(). */
1281		if (ubi_is_module())
1282			goto out_detach;
1283	}
1284
1285	return 0;
1286
1287out_detach:
1288	for (k = 0; k < i; k++)
1289		if (ubi_devices[k]) {
1290			mutex_lock(&ubi_devices_mutex);
1291			ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1292			mutex_unlock(&ubi_devices_mutex);
1293		}
1294	ubi_debugfs_exit();
1295out_slab:
1296	kmem_cache_destroy(ubi_wl_entry_slab);
1297out_dev_unreg:
1298	misc_deregister(&ubi_ctrl_cdev);
1299out:
1300	class_unregister(&ubi_class);
1301	pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1302	return err;
1303}
1304late_initcall(ubi_init);
1305
1306static void __exit ubi_exit(void)
1307{
1308	int i;
1309
1310	ubiblock_exit();
1311
1312	for (i = 0; i < UBI_MAX_DEVICES; i++)
1313		if (ubi_devices[i]) {
1314			mutex_lock(&ubi_devices_mutex);
1315			ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1316			mutex_unlock(&ubi_devices_mutex);
1317		}
1318	ubi_debugfs_exit();
1319	kmem_cache_destroy(ubi_wl_entry_slab);
1320	misc_deregister(&ubi_ctrl_cdev);
1321	class_unregister(&ubi_class);
1322}
1323module_exit(ubi_exit);
1324
1325/**
1326 * bytes_str_to_int - convert a number of bytes string into an integer.
1327 * @str: the string to convert
1328 *
1329 * This function returns positive resulting integer in case of success and a
1330 * negative error code in case of failure.
1331 */
1332static int bytes_str_to_int(const char *str)
1333{
1334	char *endp;
1335	unsigned long result;
1336
1337	result = simple_strtoul(str, &endp, 0);
1338	if (str == endp || result >= INT_MAX) {
1339		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1340		return -EINVAL;
1341	}
1342
1343	switch (*endp) {
1344	case 'G':
1345		result *= 1024;
1346		fallthrough;
1347	case 'M':
1348		result *= 1024;
1349		fallthrough;
1350	case 'K':
1351		result *= 1024;
1352		break;
1353	case '\0':
1354		break;
1355	default:
1356		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1357		return -EINVAL;
1358	}
1359
1360	return result;
1361}
1362
1363/**
1364 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1365 * @val: the parameter value to parse
1366 * @kp: not used
1367 *
1368 * This function returns zero in case of success and a negative error code in
1369 * case of error.
1370 */
1371static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1372{
1373	int i, len;
1374	struct mtd_dev_param *p;
1375	char buf[MTD_PARAM_LEN_MAX];
1376	char *pbuf = &buf[0];
1377	char *tokens[MTD_PARAM_MAX_COUNT], *token;
1378
1379	if (!val)
1380		return -EINVAL;
1381
1382	if (mtd_devs == UBI_MAX_DEVICES) {
1383		pr_err("UBI error: too many parameters, max. is %d\n",
1384		       UBI_MAX_DEVICES);
1385		return -EINVAL;
1386	}
1387
1388	len = strnlen(val, MTD_PARAM_LEN_MAX);
1389	if (len == MTD_PARAM_LEN_MAX) {
1390		pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1391		       val, MTD_PARAM_LEN_MAX);
1392		return -EINVAL;
1393	}
1394
1395	if (len == 0) {
1396		pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1397		return 0;
1398	}
1399
1400	strcpy(buf, val);
1401
1402	/* Get rid of the final newline */
1403	if (buf[len - 1] == '\n')
1404		buf[len - 1] = '\0';
1405
1406	for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1407		tokens[i] = strsep(&pbuf, ",");
1408
1409	if (pbuf) {
1410		pr_err("UBI error: too many arguments at \"%s\"\n", val);
1411		return -EINVAL;
1412	}
1413
1414	p = &mtd_dev_param[mtd_devs];
1415	strcpy(&p->name[0], tokens[0]);
1416
1417	token = tokens[1];
1418	if (token) {
1419		p->vid_hdr_offs = bytes_str_to_int(token);
1420
1421		if (p->vid_hdr_offs < 0)
1422			return p->vid_hdr_offs;
1423	}
1424
1425	token = tokens[2];
1426	if (token) {
1427		int err = kstrtoint(token, 10, &p->max_beb_per1024);
1428
1429		if (err) {
1430			pr_err("UBI error: bad value for max_beb_per1024 parameter: %s",
1431			       token);
1432			return -EINVAL;
1433		}
1434	}
1435
1436	token = tokens[3];
1437	if (token) {
1438		int err = kstrtoint(token, 10, &p->ubi_num);
1439
1440		if (err) {
1441			pr_err("UBI error: bad value for ubi_num parameter: %s",
1442			       token);
1443			return -EINVAL;
1444		}
1445	} else
1446		p->ubi_num = UBI_DEV_NUM_AUTO;
1447
1448	mtd_devs += 1;
1449	return 0;
1450}
1451
1452module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1453MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1454		      "Multiple \"mtd\" parameters may be specified.\n"
1455		      "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1456		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1457		      "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1458		      __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1459		      "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1460		      "\n"
1461		      "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1462		      "Example 2: mtd=content,1984 mtd=4 - attach MTD device with name \"content\" using VID header offset 1984, and MTD device number 4 with default VID header offset.\n"
1463		      "Example 3: mtd=/dev/mtd1,0,25 - attach MTD device /dev/mtd1 using default VID header offset and reserve 25*nand_size_in_blocks/1024 erase blocks for bad block handling.\n"
1464		      "Example 4: mtd=/dev/mtd1,0,0,5 - attach MTD device /dev/mtd1 to UBI 5 and using default values for the other fields.\n"
1465		      "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1466#ifdef CONFIG_MTD_UBI_FASTMAP
1467module_param(fm_autoconvert, bool, 0644);
1468MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1469module_param(fm_debug, bool, 0);
1470MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1471#endif
1472MODULE_VERSION(__stringify(UBI_VERSION));
1473MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1474MODULE_AUTHOR("Artem Bityutskiy");
1475MODULE_LICENSE("GPL");