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 (���������������� ����������),
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/of.h>
31#include <linux/slab.h>
32#include <linux/major.h>
33#include "ubi.h"
34
35/* Maximum length of the 'mtd=' parameter */
36#define MTD_PARAM_LEN_MAX 64
37
38/* Maximum number of comma-separated items in the 'mtd=' parameter */
39#define MTD_PARAM_MAX_COUNT 6
40
41/* Maximum value for the number of bad PEBs per 1024 PEBs */
42#define MAX_MTD_UBI_BEB_LIMIT 768
43
44#ifdef CONFIG_MTD_UBI_MODULE
45#define ubi_is_module() 1
46#else
47#define ubi_is_module() 0
48#endif
49
50/**
51 * struct mtd_dev_param - MTD device parameter description data structure.
52 * @name: MTD character device node path, MTD device name, or MTD device number
53 *        string
54 * @ubi_num: UBI number
55 * @vid_hdr_offs: VID header offset
56 * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
57 * @enable_fm: enable fastmap when value is non-zero
58 * @need_resv_pool: reserve pool->max_size pebs when value is none-zero
59 */
60struct mtd_dev_param {
61	char name[MTD_PARAM_LEN_MAX];
62	int ubi_num;
63	int vid_hdr_offs;
64	int max_beb_per1024;
65	int enable_fm;
66	int need_resv_pool;
67};
68
69/* Numbers of elements set in the @mtd_dev_param array */
70static int mtd_devs;
71
72/* MTD devices specification parameters */
73static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
74#ifdef CONFIG_MTD_UBI_FASTMAP
75/* UBI module parameter to enable fastmap automatically on non-fastmap images */
76static bool fm_autoconvert;
77static bool fm_debug;
78#endif
79
80/* Slab cache for wear-leveling entries */
81struct kmem_cache *ubi_wl_entry_slab;
82
83/* UBI control character device */
84static struct miscdevice ubi_ctrl_cdev = {
85	.minor = MISC_DYNAMIC_MINOR,
86	.name = "ubi_ctrl",
87	.fops = &ubi_ctrl_cdev_operations,
88};
89
90/* All UBI devices in system */
91static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
92
93/* Serializes UBI devices creations and removals */
94DEFINE_MUTEX(ubi_devices_mutex);
95
96/* Protects @ubi_devices, @ubi->ref_count and @ubi->is_dead */
97static DEFINE_SPINLOCK(ubi_devices_lock);
98
99/* "Show" method for files in '/<sysfs>/class/ubi/' */
100/* UBI version attribute ('/<sysfs>/class/ubi/version') */
101static ssize_t version_show(const struct class *class, const struct class_attribute *attr,
102			    char *buf)
103{
104	return sprintf(buf, "%d\n", UBI_VERSION);
105}
106static CLASS_ATTR_RO(version);
107
108static struct attribute *ubi_class_attrs[] = {
109	&class_attr_version.attr,
110	NULL,
111};
112ATTRIBUTE_GROUPS(ubi_class);
113
114/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
115struct class ubi_class = {
116	.name		= UBI_NAME_STR,
117	.class_groups	= ubi_class_groups,
118};
119
120static ssize_t dev_attribute_show(struct device *dev,
121				  struct device_attribute *attr, char *buf);
122
123/* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
124static struct device_attribute dev_eraseblock_size =
125	__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
126static struct device_attribute dev_avail_eraseblocks =
127	__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
128static struct device_attribute dev_total_eraseblocks =
129	__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
130static struct device_attribute dev_volumes_count =
131	__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
132static struct device_attribute dev_max_ec =
133	__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
134static struct device_attribute dev_reserved_for_bad =
135	__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
136static struct device_attribute dev_bad_peb_count =
137	__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
138static struct device_attribute dev_max_vol_count =
139	__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
140static struct device_attribute dev_min_io_size =
141	__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
142static struct device_attribute dev_bgt_enabled =
143	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
144static struct device_attribute dev_mtd_num =
145	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
146static struct device_attribute dev_ro_mode =
147	__ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
148
149/**
150 * ubi_volume_notify - send a volume change notification.
151 * @ubi: UBI device description object
152 * @vol: volume description object of the changed volume
153 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
154 *
155 * This is a helper function which notifies all subscribers about a volume
156 * change event (creation, removal, re-sizing, re-naming, updating). Returns
157 * zero in case of success and a negative error code in case of failure.
158 */
159int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
160{
161	int ret;
162	struct ubi_notification nt;
163
164	ubi_do_get_device_info(ubi, &nt.di);
165	ubi_do_get_volume_info(ubi, vol, &nt.vi);
166
167	switch (ntype) {
168	case UBI_VOLUME_ADDED:
169	case UBI_VOLUME_REMOVED:
170	case UBI_VOLUME_RESIZED:
171	case UBI_VOLUME_RENAMED:
172		ret = ubi_update_fastmap(ubi);
173		if (ret)
174			ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
175	}
176
177	return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
178}
179
180/**
181 * ubi_notify_all - send a notification to all volumes.
182 * @ubi: UBI device description object
183 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
184 * @nb: the notifier to call
185 *
186 * This function walks all volumes of UBI device @ubi and sends the @ntype
187 * notification for each volume. If @nb is %NULL, then all registered notifiers
188 * are called, otherwise only the @nb notifier is called. Returns the number of
189 * sent notifications.
190 */
191int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
192{
193	struct ubi_notification nt;
194	int i, count = 0;
195
196	ubi_do_get_device_info(ubi, &nt.di);
197
198	mutex_lock(&ubi->device_mutex);
199	for (i = 0; i < ubi->vtbl_slots; i++) {
200		/*
201		 * Since the @ubi->device is locked, and we are not going to
202		 * change @ubi->volumes, we do not have to lock
203		 * @ubi->volumes_lock.
204		 */
205		if (!ubi->volumes[i])
206			continue;
207
208		ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
209		if (nb)
210			nb->notifier_call(nb, ntype, &nt);
211		else
212			blocking_notifier_call_chain(&ubi_notifiers, ntype,
213						     &nt);
214		count += 1;
215	}
216	mutex_unlock(&ubi->device_mutex);
217
218	return count;
219}
220
221/**
222 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
223 * @nb: the notifier to call
224 *
225 * This function walks all UBI devices and volumes and sends the
226 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
227 * registered notifiers are called, otherwise only the @nb notifier is called.
228 * Returns the number of sent notifications.
229 */
230int ubi_enumerate_volumes(struct notifier_block *nb)
231{
232	int i, count = 0;
233
234	/*
235	 * Since the @ubi_devices_mutex is locked, and we are not going to
236	 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
237	 */
238	for (i = 0; i < UBI_MAX_DEVICES; i++) {
239		struct ubi_device *ubi = ubi_devices[i];
240
241		if (!ubi)
242			continue;
243		count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
244	}
245
246	return count;
247}
248
249/**
250 * ubi_get_device - get UBI device.
251 * @ubi_num: UBI device number
252 *
253 * This function returns UBI device description object for UBI device number
254 * @ubi_num, or %NULL if the device does not exist. This function increases the
255 * device reference count to prevent removal of the device. In other words, the
256 * device cannot be removed if its reference count is not zero.
257 */
258struct ubi_device *ubi_get_device(int ubi_num)
259{
260	struct ubi_device *ubi;
261
262	spin_lock(&ubi_devices_lock);
263	ubi = ubi_devices[ubi_num];
264	if (ubi && ubi->is_dead)
265		ubi = NULL;
266
267	if (ubi) {
268		ubi_assert(ubi->ref_count >= 0);
269		ubi->ref_count += 1;
270		get_device(&ubi->dev);
271	}
272	spin_unlock(&ubi_devices_lock);
273
274	return ubi;
275}
276
277/**
278 * ubi_put_device - drop an UBI device reference.
279 * @ubi: UBI device description object
280 */
281void ubi_put_device(struct ubi_device *ubi)
282{
283	spin_lock(&ubi_devices_lock);
284	ubi->ref_count -= 1;
285	put_device(&ubi->dev);
286	spin_unlock(&ubi_devices_lock);
287}
288
289/**
290 * ubi_get_by_major - get UBI device by character device major number.
291 * @major: major number
292 *
293 * This function is similar to 'ubi_get_device()', but it searches the device
294 * by its major number.
295 */
296struct ubi_device *ubi_get_by_major(int major)
297{
298	int i;
299	struct ubi_device *ubi;
300
301	spin_lock(&ubi_devices_lock);
302	for (i = 0; i < UBI_MAX_DEVICES; i++) {
303		ubi = ubi_devices[i];
304		if (ubi && !ubi->is_dead && MAJOR(ubi->cdev.dev) == major) {
305			ubi_assert(ubi->ref_count >= 0);
306			ubi->ref_count += 1;
307			get_device(&ubi->dev);
308			spin_unlock(&ubi_devices_lock);
309			return ubi;
310		}
311	}
312	spin_unlock(&ubi_devices_lock);
313
314	return NULL;
315}
316
317/**
318 * ubi_major2num - get UBI device number by character device major number.
319 * @major: major number
320 *
321 * This function searches UBI device number object by its major number. If UBI
322 * device was not found, this function returns -ENODEV, otherwise the UBI device
323 * number is returned.
324 */
325int ubi_major2num(int major)
326{
327	int i, ubi_num = -ENODEV;
328
329	spin_lock(&ubi_devices_lock);
330	for (i = 0; i < UBI_MAX_DEVICES; i++) {
331		struct ubi_device *ubi = ubi_devices[i];
332
333		if (ubi && !ubi->is_dead && MAJOR(ubi->cdev.dev) == major) {
334			ubi_num = ubi->ubi_num;
335			break;
336		}
337	}
338	spin_unlock(&ubi_devices_lock);
339
340	return ubi_num;
341}
342
343/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
344static ssize_t dev_attribute_show(struct device *dev,
345				  struct device_attribute *attr, char *buf)
346{
347	ssize_t ret;
348	struct ubi_device *ubi;
349
350	/*
351	 * The below code looks weird, but it actually makes sense. We get the
352	 * UBI device reference from the contained 'struct ubi_device'. But it
353	 * is unclear if the device was removed or not yet. Indeed, if the
354	 * device was removed before we increased its reference count,
355	 * 'ubi_get_device()' will return -ENODEV and we fail.
356	 *
357	 * Remember, 'struct ubi_device' is freed in the release function, so
358	 * we still can use 'ubi->ubi_num'.
359	 */
360	ubi = container_of(dev, struct ubi_device, dev);
361
362	if (attr == &dev_eraseblock_size)
363		ret = sprintf(buf, "%d\n", ubi->leb_size);
364	else if (attr == &dev_avail_eraseblocks)
365		ret = sprintf(buf, "%d\n", ubi->avail_pebs);
366	else if (attr == &dev_total_eraseblocks)
367		ret = sprintf(buf, "%d\n", ubi->good_peb_count);
368	else if (attr == &dev_volumes_count)
369		ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
370	else if (attr == &dev_max_ec)
371		ret = sprintf(buf, "%d\n", ubi->max_ec);
372	else if (attr == &dev_reserved_for_bad)
373		ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
374	else if (attr == &dev_bad_peb_count)
375		ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
376	else if (attr == &dev_max_vol_count)
377		ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
378	else if (attr == &dev_min_io_size)
379		ret = sprintf(buf, "%d\n", ubi->min_io_size);
380	else if (attr == &dev_bgt_enabled)
381		ret = sprintf(buf, "%d\n", ubi->thread_enabled);
382	else if (attr == &dev_mtd_num)
383		ret = sprintf(buf, "%d\n", ubi->mtd->index);
384	else if (attr == &dev_ro_mode)
385		ret = sprintf(buf, "%d\n", ubi->ro_mode);
386	else
387		ret = -EINVAL;
388
389	return ret;
390}
391
392static struct attribute *ubi_dev_attrs[] = {
393	&dev_eraseblock_size.attr,
394	&dev_avail_eraseblocks.attr,
395	&dev_total_eraseblocks.attr,
396	&dev_volumes_count.attr,
397	&dev_max_ec.attr,
398	&dev_reserved_for_bad.attr,
399	&dev_bad_peb_count.attr,
400	&dev_max_vol_count.attr,
401	&dev_min_io_size.attr,
402	&dev_bgt_enabled.attr,
403	&dev_mtd_num.attr,
404	&dev_ro_mode.attr,
405	NULL
406};
407ATTRIBUTE_GROUPS(ubi_dev);
408
409static void dev_release(struct device *dev)
410{
411	struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
412
413	kfree(ubi);
414}
415
416/**
417 * kill_volumes - destroy all user volumes.
418 * @ubi: UBI device description object
419 */
420static void kill_volumes(struct ubi_device *ubi)
421{
422	int i;
423
424	for (i = 0; i < ubi->vtbl_slots; i++)
425		if (ubi->volumes[i])
426			ubi_free_volume(ubi, ubi->volumes[i]);
427}
428
429/**
430 * uif_init - initialize user interfaces for an UBI device.
431 * @ubi: UBI device description object
432 *
433 * This function initializes various user interfaces for an UBI device. If the
434 * initialization fails at an early stage, this function frees all the
435 * resources it allocated, returns an error.
436 *
437 * This function returns zero in case of success and a negative error code in
438 * case of failure.
439 */
440static int uif_init(struct ubi_device *ubi)
441{
442	int i, err;
443	dev_t dev;
444
445	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
446
447	/*
448	 * Major numbers for the UBI character devices are allocated
449	 * dynamically. Major numbers of volume character devices are
450	 * equivalent to ones of the corresponding UBI character device. Minor
451	 * numbers of UBI character devices are 0, while minor numbers of
452	 * volume character devices start from 1. Thus, we allocate one major
453	 * number and ubi->vtbl_slots + 1 minor numbers.
454	 */
455	err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
456	if (err) {
457		ubi_err(ubi, "cannot register UBI character devices");
458		return err;
459	}
460
461	ubi->dev.devt = dev;
462
463	ubi_assert(MINOR(dev) == 0);
464	cdev_init(&ubi->cdev, &ubi_cdev_operations);
465	dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
466	ubi->cdev.owner = THIS_MODULE;
467
468	dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
469	err = cdev_device_add(&ubi->cdev, &ubi->dev);
470	if (err)
471		goto out_unreg;
472
473	for (i = 0; i < ubi->vtbl_slots; i++)
474		if (ubi->volumes[i]) {
475			err = ubi_add_volume(ubi, ubi->volumes[i]);
476			if (err) {
477				ubi_err(ubi, "cannot add volume %d", i);
478				ubi->volumes[i] = NULL;
479				goto out_volumes;
480			}
481		}
482
483	return 0;
484
485out_volumes:
486	kill_volumes(ubi);
487	cdev_device_del(&ubi->cdev, &ubi->dev);
488out_unreg:
489	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
490	ubi_err(ubi, "cannot initialize UBI %s, error %d",
491		ubi->ubi_name, err);
492	return err;
493}
494
495/**
496 * uif_close - close user interfaces for an UBI device.
497 * @ubi: UBI device description object
498 *
499 * Note, since this function un-registers UBI volume device objects (@vol->dev),
500 * the memory allocated voe the volumes is freed as well (in the release
501 * function).
502 */
503static void uif_close(struct ubi_device *ubi)
504{
505	kill_volumes(ubi);
506	cdev_device_del(&ubi->cdev, &ubi->dev);
507	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
508}
509
510/**
511 * ubi_free_volumes_from - free volumes from specific index.
512 * @ubi: UBI device description object
513 * @from: the start index used for volume free.
514 */
515static void ubi_free_volumes_from(struct ubi_device *ubi, int from)
516{
517	int i;
518
519	for (i = from; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
520		if (!ubi->volumes[i] || ubi->volumes[i]->is_dead)
521			continue;
522		ubi_eba_replace_table(ubi->volumes[i], NULL);
523		ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
524		kfree(ubi->volumes[i]);
525		ubi->volumes[i] = NULL;
526	}
527}
528
529/**
530 * ubi_free_all_volumes - free all volumes.
531 * @ubi: UBI device description object
532 */
533void ubi_free_all_volumes(struct ubi_device *ubi)
534{
535	ubi_free_volumes_from(ubi, 0);
536}
537
538/**
539 * ubi_free_internal_volumes - free internal volumes.
540 * @ubi: UBI device description object
541 */
542void ubi_free_internal_volumes(struct ubi_device *ubi)
543{
544	ubi_free_volumes_from(ubi, ubi->vtbl_slots);
545}
546
547static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
548{
549	int limit, device_pebs;
550	uint64_t device_size;
551
552	if (!max_beb_per1024) {
553		/*
554		 * Since max_beb_per1024 has not been set by the user in either
555		 * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
556		 * limit if it is supported by the device.
557		 */
558		limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
559		if (limit < 0)
560			return 0;
561		return limit;
562	}
563
564	/*
565	 * Here we are using size of the entire flash chip and
566	 * not just the MTD partition size because the maximum
567	 * number of bad eraseblocks is a percentage of the
568	 * whole device and bad eraseblocks are not fairly
569	 * distributed over the flash chip. So the worst case
570	 * is that all the bad eraseblocks of the chip are in
571	 * the MTD partition we are attaching (ubi->mtd).
572	 */
573	device_size = mtd_get_device_size(ubi->mtd);
574	device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
575	limit = mult_frac(device_pebs, max_beb_per1024, 1024);
576
577	/* Round it up */
578	if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
579		limit += 1;
580
581	return limit;
582}
583
584/**
585 * io_init - initialize I/O sub-system for a given UBI device.
586 * @ubi: UBI device description object
587 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
588 *
589 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
590 * assumed:
591 *   o EC header is always at offset zero - this cannot be changed;
592 *   o VID header starts just after the EC header at the closest address
593 *     aligned to @io->hdrs_min_io_size;
594 *   o data starts just after the VID header at the closest address aligned to
595 *     @io->min_io_size
596 *
597 * This function returns zero in case of success and a negative error code in
598 * case of failure.
599 */
600static int io_init(struct ubi_device *ubi, int max_beb_per1024)
601{
602	dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
603	dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
604
605	if (ubi->mtd->numeraseregions != 0) {
606		/*
607		 * Some flashes have several erase regions. Different regions
608		 * may have different eraseblock size and other
609		 * characteristics. It looks like mostly multi-region flashes
610		 * have one "main" region and one or more small regions to
611		 * store boot loader code or boot parameters or whatever. I
612		 * guess we should just pick the largest region. But this is
613		 * not implemented.
614		 */
615		ubi_err(ubi, "multiple regions, not implemented");
616		return -EINVAL;
617	}
618
619	if (ubi->vid_hdr_offset < 0)
620		return -EINVAL;
621
622	/*
623	 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
624	 * physical eraseblocks maximum.
625	 */
626
627	ubi->peb_size   = ubi->mtd->erasesize;
628	ubi->peb_count  = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
629	ubi->flash_size = ubi->mtd->size;
630
631	if (mtd_can_have_bb(ubi->mtd)) {
632		ubi->bad_allowed = 1;
633		ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
634	}
635
636	if (ubi->mtd->type == MTD_NORFLASH)
637		ubi->nor_flash = 1;
638
639	ubi->min_io_size = ubi->mtd->writesize;
640	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
641
642	/*
643	 * Make sure minimal I/O unit is power of 2. Note, there is no
644	 * fundamental reason for this assumption. It is just an optimization
645	 * which allows us to avoid costly division operations.
646	 */
647	if (!is_power_of_2(ubi->min_io_size)) {
648		ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
649			ubi->min_io_size);
650		return -EINVAL;
651	}
652
653	ubi_assert(ubi->hdrs_min_io_size > 0);
654	ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
655	ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
656
657	ubi->max_write_size = ubi->mtd->writebufsize;
658	/*
659	 * Maximum write size has to be greater or equivalent to min. I/O
660	 * size, and be multiple of min. I/O size.
661	 */
662	if (ubi->max_write_size < ubi->min_io_size ||
663	    ubi->max_write_size % ubi->min_io_size ||
664	    !is_power_of_2(ubi->max_write_size)) {
665		ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
666			ubi->max_write_size, ubi->min_io_size);
667		return -EINVAL;
668	}
669
670	/* Calculate default aligned sizes of EC and VID headers */
671	ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
672	ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
673
674	dbg_gen("min_io_size      %d", ubi->min_io_size);
675	dbg_gen("max_write_size   %d", ubi->max_write_size);
676	dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
677	dbg_gen("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
678	dbg_gen("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
679
680	if (ubi->vid_hdr_offset == 0)
681		/* Default offset */
682		ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
683				      ubi->ec_hdr_alsize;
684	else {
685		ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
686						~(ubi->hdrs_min_io_size - 1);
687		ubi->vid_hdr_shift = ubi->vid_hdr_offset -
688						ubi->vid_hdr_aloffset;
689	}
690
691	/*
692	 * Memory allocation for VID header is ubi->vid_hdr_alsize
693	 * which is described in comments in io.c.
694	 * Make sure VID header shift + UBI_VID_HDR_SIZE not exceeds
695	 * ubi->vid_hdr_alsize, so that all vid header operations
696	 * won't access memory out of bounds.
697	 */
698	if ((ubi->vid_hdr_shift + UBI_VID_HDR_SIZE) > ubi->vid_hdr_alsize) {
699		ubi_err(ubi, "Invalid VID header offset %d, VID header shift(%d)"
700			" + VID header size(%zu) > VID header aligned size(%d).",
701			ubi->vid_hdr_offset, ubi->vid_hdr_shift,
702			UBI_VID_HDR_SIZE, ubi->vid_hdr_alsize);
703		return -EINVAL;
704	}
705
706	/* Similar for the data offset */
707	ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
708	ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
709
710	dbg_gen("vid_hdr_offset   %d", ubi->vid_hdr_offset);
711	dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
712	dbg_gen("vid_hdr_shift    %d", ubi->vid_hdr_shift);
713	dbg_gen("leb_start        %d", ubi->leb_start);
714
715	/* The shift must be aligned to 32-bit boundary */
716	if (ubi->vid_hdr_shift % 4) {
717		ubi_err(ubi, "unaligned VID header shift %d",
718			ubi->vid_hdr_shift);
719		return -EINVAL;
720	}
721
722	/* Check sanity */
723	if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
724	    ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
725	    ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
726	    ubi->leb_start & (ubi->min_io_size - 1)) {
727		ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
728			ubi->vid_hdr_offset, ubi->leb_start);
729		return -EINVAL;
730	}
731
732	/*
733	 * Set maximum amount of physical erroneous eraseblocks to be 10%.
734	 * Erroneous PEB are those which have read errors.
735	 */
736	ubi->max_erroneous = ubi->peb_count / 10;
737	if (ubi->max_erroneous < 16)
738		ubi->max_erroneous = 16;
739	dbg_gen("max_erroneous    %d", ubi->max_erroneous);
740
741	/*
742	 * It may happen that EC and VID headers are situated in one minimal
743	 * I/O unit. In this case we can only accept this UBI image in
744	 * read-only mode.
745	 */
746	if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
747		ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
748		ubi->ro_mode = 1;
749	}
750
751	ubi->leb_size = ubi->peb_size - ubi->leb_start;
752
753	if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
754		ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
755			ubi->mtd->index);
756		ubi->ro_mode = 1;
757	}
758
759	/*
760	 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
761	 * unfortunately, MTD does not provide this information. We should loop
762	 * over all physical eraseblocks and invoke mtd->block_is_bad() for
763	 * each physical eraseblock. So, we leave @ubi->bad_peb_count
764	 * uninitialized so far.
765	 */
766
767	return 0;
768}
769
770/**
771 * autoresize - re-size the volume which has the "auto-resize" flag set.
772 * @ubi: UBI device description object
773 * @vol_id: ID of the volume to re-size
774 *
775 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
776 * the volume table to the largest possible size. See comments in ubi-header.h
777 * for more description of the flag. Returns zero in case of success and a
778 * negative error code in case of failure.
779 */
780static int autoresize(struct ubi_device *ubi, int vol_id)
781{
782	struct ubi_volume_desc desc;
783	struct ubi_volume *vol = ubi->volumes[vol_id];
784	int err, old_reserved_pebs = vol->reserved_pebs;
785
786	if (ubi->ro_mode) {
787		ubi_warn(ubi, "skip auto-resize because of R/O mode");
788		return 0;
789	}
790
791	/*
792	 * Clear the auto-resize flag in the volume in-memory copy of the
793	 * volume table, and 'ubi_resize_volume()' will propagate this change
794	 * to the flash.
795	 */
796	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
797
798	if (ubi->avail_pebs == 0) {
799		struct ubi_vtbl_record vtbl_rec;
800
801		/*
802		 * No available PEBs to re-size the volume, clear the flag on
803		 * flash and exit.
804		 */
805		vtbl_rec = ubi->vtbl[vol_id];
806		err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
807		if (err)
808			ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
809				vol_id);
810	} else {
811		desc.vol = vol;
812		err = ubi_resize_volume(&desc,
813					old_reserved_pebs + ubi->avail_pebs);
814		if (err)
815			ubi_err(ubi, "cannot auto-resize volume %d",
816				vol_id);
817	}
818
819	if (err)
820		return err;
821
822	ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
823		vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
824	return 0;
825}
826
827/**
828 * ubi_attach_mtd_dev - attach an MTD device.
829 * @mtd: MTD device description object
830 * @ubi_num: number to assign to the new UBI device
831 * @vid_hdr_offset: VID header offset
832 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
833 * @disable_fm: whether disable fastmap
834 * @need_resv_pool: whether reserve pebs to fill fm_pool
835 *
836 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
837 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
838 * which case this function finds a vacant device number and assigns it
839 * automatically. Returns the new UBI device number in case of success and a
840 * negative error code in case of failure.
841 *
842 * If @disable_fm is true, ubi doesn't create new fastmap even the module param
843 * 'fm_autoconvert' is set, and existed old fastmap will be destroyed after
844 * doing full scanning.
845 *
846 * Note, the invocations of this function has to be serialized by the
847 * @ubi_devices_mutex.
848 */
849int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
850		       int vid_hdr_offset, int max_beb_per1024, bool disable_fm,
851		       bool need_resv_pool)
852{
853	struct ubi_device *ubi;
854	int i, err;
855
856	if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
857		return -EINVAL;
858
859	if (!max_beb_per1024)
860		max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
861
862	/*
863	 * Check if we already have the same MTD device attached.
864	 *
865	 * Note, this function assumes that UBI devices creations and deletions
866	 * are serialized, so it does not take the &ubi_devices_lock.
867	 */
868	for (i = 0; i < UBI_MAX_DEVICES; i++) {
869		ubi = ubi_devices[i];
870		if (ubi && mtd->index == ubi->mtd->index) {
871			pr_err("ubi: mtd%d is already attached to ubi%d\n",
872				mtd->index, i);
873			return -EEXIST;
874		}
875	}
876
877	/*
878	 * Make sure this MTD device is not emulated on top of an UBI volume
879	 * already. Well, generally this recursion works fine, but there are
880	 * different problems like the UBI module takes a reference to itself
881	 * by attaching (and thus, opening) the emulated MTD device. This
882	 * results in inability to unload the module. And in general it makes
883	 * no sense to attach emulated MTD devices, so we prohibit this.
884	 */
885	if (mtd->type == MTD_UBIVOLUME) {
886		pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
887			mtd->index);
888		return -EINVAL;
889	}
890
891	/*
892	 * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
893	 * MLC NAND is different and needs special care, otherwise UBI or UBIFS
894	 * will die soon and you will lose all your data.
895	 * Relax this rule if the partition we're attaching to operates in SLC
896	 * mode.
897	 */
898	if (mtd->type == MTD_MLCNANDFLASH &&
899	    !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
900		pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
901			mtd->index);
902		return -EINVAL;
903	}
904
905	/* UBI cannot work on flashes with zero erasesize. */
906	if (!mtd->erasesize) {
907		pr_err("ubi: refuse attaching mtd%d - zero erasesize flash is not supported\n",
908			mtd->index);
909		return -EINVAL;
910	}
911
912	if (ubi_num == UBI_DEV_NUM_AUTO) {
913		/* Search for an empty slot in the @ubi_devices array */
914		for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
915			if (!ubi_devices[ubi_num])
916				break;
917		if (ubi_num == UBI_MAX_DEVICES) {
918			pr_err("ubi: only %d UBI devices may be created\n",
919				UBI_MAX_DEVICES);
920			return -ENFILE;
921		}
922	} else {
923		if (ubi_num >= UBI_MAX_DEVICES)
924			return -EINVAL;
925
926		/* Make sure ubi_num is not busy */
927		if (ubi_devices[ubi_num]) {
928			pr_err("ubi: ubi%i already exists\n", ubi_num);
929			return -EEXIST;
930		}
931	}
932
933	ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
934	if (!ubi)
935		return -ENOMEM;
936
937	device_initialize(&ubi->dev);
938	ubi->dev.release = dev_release;
939	ubi->dev.class = &ubi_class;
940	ubi->dev.groups = ubi_dev_groups;
941	ubi->dev.parent = &mtd->dev;
942
943	ubi->mtd = mtd;
944	ubi->ubi_num = ubi_num;
945	ubi->vid_hdr_offset = vid_hdr_offset;
946	ubi->autoresize_vol_id = -1;
947
948#ifdef CONFIG_MTD_UBI_FASTMAP
949	ubi->fm_pool.used = ubi->fm_pool.size = 0;
950	ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
951
952	/*
953	 * fm_pool.max_size is 5% of the total number of PEBs but it's also
954	 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
955	 */
956	ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
957		ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
958	ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
959		UBI_FM_MIN_POOL_SIZE);
960
961	ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
962	ubi->fm_pool_rsv_cnt = need_resv_pool ? ubi->fm_pool.max_size : 0;
963	ubi->fm_disabled = (!fm_autoconvert || disable_fm) ? 1 : 0;
964	if (fm_debug)
965		ubi_enable_dbg_chk_fastmap(ubi);
966
967	if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
968	    <= UBI_FM_MAX_START) {
969		ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
970			UBI_FM_MAX_START);
971		ubi->fm_disabled = 1;
972	}
973
974	ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
975	ubi_msg(ubi, "default fastmap WL pool size: %d",
976		ubi->fm_wl_pool.max_size);
977#else
978	ubi->fm_disabled = 1;
979#endif
980	mutex_init(&ubi->buf_mutex);
981	mutex_init(&ubi->ckvol_mutex);
982	mutex_init(&ubi->device_mutex);
983	spin_lock_init(&ubi->volumes_lock);
984	init_rwsem(&ubi->fm_protect);
985	init_rwsem(&ubi->fm_eba_sem);
986
987	ubi_msg(ubi, "attaching mtd%d", mtd->index);
988
989	err = io_init(ubi, max_beb_per1024);
990	if (err)
991		goto out_free;
992
993	err = -ENOMEM;
994	ubi->peb_buf = vmalloc(ubi->peb_size);
995	if (!ubi->peb_buf)
996		goto out_free;
997
998#ifdef CONFIG_MTD_UBI_FASTMAP
999	ubi->fm_size = ubi_calc_fm_size(ubi);
1000	ubi->fm_buf = vzalloc(ubi->fm_size);
1001	if (!ubi->fm_buf)
1002		goto out_free;
1003#endif
1004	err = ubi_attach(ubi, disable_fm ? 1 : 0);
1005	if (err) {
1006		ubi_err(ubi, "failed to attach mtd%d, error %d",
1007			mtd->index, err);
1008		goto out_free;
1009	}
1010
1011	if (ubi->autoresize_vol_id != -1) {
1012		err = autoresize(ubi, ubi->autoresize_vol_id);
1013		if (err)
1014			goto out_detach;
1015	}
1016
1017	err = uif_init(ubi);
1018	if (err)
1019		goto out_detach;
1020
1021	err = ubi_debugfs_init_dev(ubi);
1022	if (err)
1023		goto out_uif;
1024
1025	ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
1026	if (IS_ERR(ubi->bgt_thread)) {
1027		err = PTR_ERR(ubi->bgt_thread);
1028		ubi_err(ubi, "cannot spawn \"%s\", error %d",
1029			ubi->bgt_name, err);
1030		goto out_debugfs;
1031	}
1032
1033	ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
1034		mtd->index, mtd->name, ubi->flash_size >> 20);
1035	ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
1036		ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
1037	ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
1038		ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1039	ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1040		ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1041	ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1042		ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1043	ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1044		ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1045		ubi->vtbl_slots);
1046	ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1047		ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1048		ubi->image_seq);
1049	ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1050		ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1051
1052	/*
1053	 * The below lock makes sure we do not race with 'ubi_thread()' which
1054	 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1055	 */
1056	spin_lock(&ubi->wl_lock);
1057	ubi->thread_enabled = 1;
1058	wake_up_process(ubi->bgt_thread);
1059	spin_unlock(&ubi->wl_lock);
1060
1061	ubi_devices[ubi_num] = ubi;
1062	ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1063	return ubi_num;
1064
1065out_debugfs:
1066	ubi_debugfs_exit_dev(ubi);
1067out_uif:
1068	uif_close(ubi);
1069out_detach:
1070	ubi_wl_close(ubi);
1071	ubi_free_all_volumes(ubi);
1072	vfree(ubi->vtbl);
1073out_free:
1074	vfree(ubi->peb_buf);
1075	vfree(ubi->fm_buf);
1076	put_device(&ubi->dev);
1077	return err;
1078}
1079
1080/**
1081 * ubi_detach_mtd_dev - detach an MTD device.
1082 * @ubi_num: UBI device number to detach from
1083 * @anyway: detach MTD even if device reference count is not zero
1084 *
1085 * This function destroys an UBI device number @ubi_num and detaches the
1086 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1087 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1088 * exist.
1089 *
1090 * Note, the invocations of this function has to be serialized by the
1091 * @ubi_devices_mutex.
1092 */
1093int ubi_detach_mtd_dev(int ubi_num, int anyway)
1094{
1095	struct ubi_device *ubi;
1096
1097	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1098		return -EINVAL;
1099
1100	ubi = ubi_get_device(ubi_num);
1101	if (!ubi)
1102		return -EINVAL;
1103
1104	spin_lock(&ubi_devices_lock);
1105	ubi->ref_count -= 1;
1106	if (ubi->ref_count) {
1107		if (!anyway) {
1108			spin_unlock(&ubi_devices_lock);
1109			return -EBUSY;
1110		}
1111		/* This may only happen if there is a bug */
1112		ubi_err(ubi, "%s reference count %d, destroy anyway",
1113			ubi->ubi_name, ubi->ref_count);
1114	}
1115	ubi->is_dead = true;
1116	spin_unlock(&ubi_devices_lock);
1117
1118	ubi_notify_all(ubi, UBI_VOLUME_SHUTDOWN, NULL);
1119
1120	spin_lock(&ubi_devices_lock);
1121	put_device(&ubi->dev);
1122	ubi_devices[ubi_num] = NULL;
1123	spin_unlock(&ubi_devices_lock);
1124
1125	ubi_assert(ubi_num == ubi->ubi_num);
1126	ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1127	ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1128#ifdef CONFIG_MTD_UBI_FASTMAP
1129	/* If we don't write a new fastmap at detach time we lose all
1130	 * EC updates that have been made since the last written fastmap.
1131	 * In case of fastmap debugging we omit the update to simulate an
1132	 * unclean shutdown. */
1133	if (!ubi_dbg_chk_fastmap(ubi))
1134		ubi_update_fastmap(ubi);
1135#endif
1136	/*
1137	 * Before freeing anything, we have to stop the background thread to
1138	 * prevent it from doing anything on this device while we are freeing.
1139	 */
1140	if (ubi->bgt_thread)
1141		kthread_stop(ubi->bgt_thread);
1142
1143#ifdef CONFIG_MTD_UBI_FASTMAP
1144	cancel_work_sync(&ubi->fm_work);
1145#endif
1146	ubi_debugfs_exit_dev(ubi);
1147	uif_close(ubi);
1148
1149	ubi_wl_close(ubi);
1150	ubi_free_internal_volumes(ubi);
1151	vfree(ubi->vtbl);
1152	vfree(ubi->peb_buf);
1153	vfree(ubi->fm_buf);
1154	ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1155	put_mtd_device(ubi->mtd);
1156	put_device(&ubi->dev);
1157	return 0;
1158}
1159
1160/**
1161 * open_mtd_by_chdev - open an MTD device by its character device node path.
1162 * @mtd_dev: MTD character device node path
1163 *
1164 * This helper function opens an MTD device by its character node device path.
1165 * Returns MTD device description object in case of success and a negative
1166 * error code in case of failure.
1167 */
1168static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1169{
1170	int err, minor;
1171	struct path path;
1172	struct kstat stat;
1173
1174	/* Probably this is an MTD character device node path */
1175	err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1176	if (err)
1177		return ERR_PTR(err);
1178
1179	err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1180	path_put(&path);
1181	if (err)
1182		return ERR_PTR(err);
1183
1184	/* MTD device number is defined by the major / minor numbers */
1185	if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1186		return ERR_PTR(-EINVAL);
1187
1188	minor = MINOR(stat.rdev);
1189
1190	if (minor & 1)
1191		/*
1192		 * Just do not think the "/dev/mtdrX" devices support is need,
1193		 * so do not support them to avoid doing extra work.
1194		 */
1195		return ERR_PTR(-EINVAL);
1196
1197	return get_mtd_device(NULL, minor / 2);
1198}
1199
1200/**
1201 * open_mtd_device - open MTD device by name, character device path, or number.
1202 * @mtd_dev: name, character device node path, or MTD device device number
1203 *
1204 * This function tries to open and MTD device described by @mtd_dev string,
1205 * which is first treated as ASCII MTD device number, and if it is not true, it
1206 * is treated as MTD device name, and if that is also not true, it is treated
1207 * as MTD character device node path. Returns MTD device description object in
1208 * case of success and a negative error code in case of failure.
1209 */
1210static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1211{
1212	struct mtd_info *mtd;
1213	int mtd_num;
1214	char *endp;
1215
1216	mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1217	if (*endp != '\0' || mtd_dev == endp) {
1218		/*
1219		 * This does not look like an ASCII integer, probably this is
1220		 * MTD device name.
1221		 */
1222		mtd = get_mtd_device_nm(mtd_dev);
1223		if (PTR_ERR(mtd) == -ENODEV)
1224			/* Probably this is an MTD character device node path */
1225			mtd = open_mtd_by_chdev(mtd_dev);
1226	} else
1227		mtd = get_mtd_device(NULL, mtd_num);
1228
1229	return mtd;
1230}
1231
1232static void ubi_notify_add(struct mtd_info *mtd)
1233{
1234	struct device_node *np = mtd_get_of_node(mtd);
1235	int err;
1236
1237	if (!of_device_is_compatible(np, "linux,ubi"))
1238		return;
1239
1240	/*
1241	 * we are already holding &mtd_table_mutex, but still need
1242	 * to bump refcount
1243	 */
1244	err = __get_mtd_device(mtd);
1245	if (err)
1246		return;
1247
1248	/* called while holding mtd_table_mutex */
1249	mutex_lock_nested(&ubi_devices_mutex, SINGLE_DEPTH_NESTING);
1250	err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO, 0, 0, false, false);
1251	mutex_unlock(&ubi_devices_mutex);
1252	if (err < 0)
1253		__put_mtd_device(mtd);
1254}
1255
1256static void ubi_notify_remove(struct mtd_info *mtd)
1257{
1258	/* do nothing for now */
1259}
1260
1261static struct mtd_notifier ubi_mtd_notifier = {
1262	.add = ubi_notify_add,
1263	.remove = ubi_notify_remove,
1264};
1265
1266static int __init ubi_init_attach(void)
1267{
1268	int err, i, k;
1269
1270	/* Attach MTD devices */
1271	for (i = 0; i < mtd_devs; i++) {
1272		struct mtd_dev_param *p = &mtd_dev_param[i];
1273		struct mtd_info *mtd;
1274
1275		cond_resched();
1276
1277		mtd = open_mtd_device(p->name);
1278		if (IS_ERR(mtd)) {
1279			err = PTR_ERR(mtd);
1280			pr_err("UBI error: cannot open mtd %s, error %d\n",
1281			       p->name, err);
1282			/* See comment below re-ubi_is_module(). */
1283			if (ubi_is_module())
1284				goto out_detach;
1285			continue;
1286		}
1287
1288		mutex_lock(&ubi_devices_mutex);
1289		err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1290					 p->vid_hdr_offs, p->max_beb_per1024,
1291					 p->enable_fm == 0,
1292					 p->need_resv_pool != 0);
1293		mutex_unlock(&ubi_devices_mutex);
1294		if (err < 0) {
1295			pr_err("UBI error: cannot attach mtd%d\n",
1296			       mtd->index);
1297			put_mtd_device(mtd);
1298
1299			/*
1300			 * Originally UBI stopped initializing on any error.
1301			 * However, later on it was found out that this
1302			 * behavior is not very good when UBI is compiled into
1303			 * the kernel and the MTD devices to attach are passed
1304			 * through the command line. Indeed, UBI failure
1305			 * stopped whole boot sequence.
1306			 *
1307			 * To fix this, we changed the behavior for the
1308			 * non-module case, but preserved the old behavior for
1309			 * the module case, just for compatibility. This is a
1310			 * little inconsistent, though.
1311			 */
1312			if (ubi_is_module())
1313				goto out_detach;
1314		}
1315	}
1316
1317	return 0;
1318
1319out_detach:
1320	for (k = 0; k < i; k++)
1321		if (ubi_devices[k]) {
1322			mutex_lock(&ubi_devices_mutex);
1323			ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1324			mutex_unlock(&ubi_devices_mutex);
1325		}
1326	return err;
1327}
1328#ifndef CONFIG_MTD_UBI_MODULE
1329late_initcall(ubi_init_attach);
1330#endif
1331
1332static int __init ubi_init(void)
1333{
1334	int err;
1335
1336	/* Ensure that EC and VID headers have correct size */
1337	BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1338	BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1339
1340	if (mtd_devs > UBI_MAX_DEVICES) {
1341		pr_err("UBI error: too many MTD devices, maximum is %d\n",
1342		       UBI_MAX_DEVICES);
1343		return -EINVAL;
1344	}
1345
1346	/* Create base sysfs directory and sysfs files */
1347	err = class_register(&ubi_class);
1348	if (err < 0)
1349		return err;
1350
1351	err = misc_register(&ubi_ctrl_cdev);
1352	if (err) {
1353		pr_err("UBI error: cannot register device\n");
1354		goto out;
1355	}
1356
1357	ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1358					      sizeof(struct ubi_wl_entry),
1359					      0, 0, NULL);
1360	if (!ubi_wl_entry_slab) {
1361		err = -ENOMEM;
1362		goto out_dev_unreg;
1363	}
1364
1365	err = ubi_debugfs_init();
1366	if (err)
1367		goto out_slab;
1368
1369	err = ubiblock_init();
1370	if (err) {
1371		pr_err("UBI error: block: cannot initialize, error %d\n", err);
1372
1373		/* See comment above re-ubi_is_module(). */
1374		if (ubi_is_module())
1375			goto out_slab;
1376	}
1377
1378	register_mtd_user(&ubi_mtd_notifier);
1379
1380	if (ubi_is_module()) {
1381		err = ubi_init_attach();
1382		if (err)
1383			goto out_mtd_notifier;
1384	}
1385
1386	return 0;
1387
1388out_mtd_notifier:
1389	unregister_mtd_user(&ubi_mtd_notifier);
1390out_slab:
1391	kmem_cache_destroy(ubi_wl_entry_slab);
1392out_dev_unreg:
1393	misc_deregister(&ubi_ctrl_cdev);
1394out:
1395	class_unregister(&ubi_class);
1396	pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1397	return err;
1398}
1399device_initcall(ubi_init);
1400
1401
1402static void __exit ubi_exit(void)
1403{
1404	int i;
1405
1406	ubiblock_exit();
1407	unregister_mtd_user(&ubi_mtd_notifier);
1408
1409	for (i = 0; i < UBI_MAX_DEVICES; i++)
1410		if (ubi_devices[i]) {
1411			mutex_lock(&ubi_devices_mutex);
1412			ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1413			mutex_unlock(&ubi_devices_mutex);
1414		}
1415	ubi_debugfs_exit();
1416	kmem_cache_destroy(ubi_wl_entry_slab);
1417	misc_deregister(&ubi_ctrl_cdev);
1418	class_unregister(&ubi_class);
1419}
1420module_exit(ubi_exit);
1421
1422/**
1423 * bytes_str_to_int - convert a number of bytes string into an integer.
1424 * @str: the string to convert
1425 *
1426 * This function returns positive resulting integer in case of success and a
1427 * negative error code in case of failure.
1428 */
1429static int bytes_str_to_int(const char *str)
1430{
1431	char *endp;
1432	unsigned long result;
1433
1434	result = simple_strtoul(str, &endp, 0);
1435	if (str == endp || result >= INT_MAX) {
1436		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1437		return -EINVAL;
1438	}
1439
1440	switch (*endp) {
1441	case 'G':
1442		result *= 1024;
1443		fallthrough;
1444	case 'M':
1445		result *= 1024;
1446		fallthrough;
1447	case 'K':
1448		result *= 1024;
1449		break;
1450	case '\0':
1451		break;
1452	default:
1453		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1454		return -EINVAL;
1455	}
1456
1457	return result;
1458}
1459
1460/**
1461 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1462 * @val: the parameter value to parse
1463 * @kp: not used
1464 *
1465 * This function returns zero in case of success and a negative error code in
1466 * case of error.
1467 */
1468static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1469{
1470	int i, len;
1471	struct mtd_dev_param *p;
1472	char buf[MTD_PARAM_LEN_MAX];
1473	char *pbuf = &buf[0];
1474	char *tokens[MTD_PARAM_MAX_COUNT], *token;
1475
1476	if (!val)
1477		return -EINVAL;
1478
1479	if (mtd_devs == UBI_MAX_DEVICES) {
1480		pr_err("UBI error: too many parameters, max. is %d\n",
1481		       UBI_MAX_DEVICES);
1482		return -EINVAL;
1483	}
1484
1485	len = strnlen(val, MTD_PARAM_LEN_MAX);
1486	if (len == MTD_PARAM_LEN_MAX) {
1487		pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1488		       val, MTD_PARAM_LEN_MAX);
1489		return -EINVAL;
1490	}
1491
1492	if (len == 0) {
1493		pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1494		return 0;
1495	}
1496
1497	strcpy(buf, val);
1498
1499	/* Get rid of the final newline */
1500	if (buf[len - 1] == '\n')
1501		buf[len - 1] = '\0';
1502
1503	for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1504		tokens[i] = strsep(&pbuf, ",");
1505
1506	if (pbuf) {
1507		pr_err("UBI error: too many arguments at \"%s\"\n", val);
1508		return -EINVAL;
1509	}
1510
1511	p = &mtd_dev_param[mtd_devs];
1512	strcpy(&p->name[0], tokens[0]);
1513
1514	token = tokens[1];
1515	if (token) {
1516		p->vid_hdr_offs = bytes_str_to_int(token);
1517
1518		if (p->vid_hdr_offs < 0)
1519			return p->vid_hdr_offs;
1520	}
1521
1522	token = tokens[2];
1523	if (token) {
1524		int err = kstrtoint(token, 10, &p->max_beb_per1024);
1525
1526		if (err) {
1527			pr_err("UBI error: bad value for max_beb_per1024 parameter: %s\n",
1528			       token);
1529			return -EINVAL;
1530		}
1531	}
1532
1533	token = tokens[3];
1534	if (token) {
1535		int err = kstrtoint(token, 10, &p->ubi_num);
1536
1537		if (err) {
1538			pr_err("UBI error: bad value for ubi_num parameter: %s\n",
1539			       token);
1540			return -EINVAL;
1541		}
1542	} else
1543		p->ubi_num = UBI_DEV_NUM_AUTO;
1544
1545	token = tokens[4];
1546	if (token) {
1547		int err = kstrtoint(token, 10, &p->enable_fm);
1548
1549		if (err) {
1550			pr_err("UBI error: bad value for enable_fm parameter: %s\n",
1551				token);
1552			return -EINVAL;
1553		}
1554	} else
1555		p->enable_fm = 0;
1556
1557	token = tokens[5];
1558	if (token) {
1559		int err = kstrtoint(token, 10, &p->need_resv_pool);
1560
1561		if (err) {
1562			pr_err("UBI error: bad value for need_resv_pool parameter: %s\n",
1563				token);
1564			return -EINVAL;
1565		}
1566	} else
1567		p->need_resv_pool = 0;
1568
1569	mtd_devs += 1;
1570	return 0;
1571}
1572
1573module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1574MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1575		      "Multiple \"mtd\" parameters may be specified.\n"
1576		      "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1577		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1578		      "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1579		      __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1580		      "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1581		      "Optional \"enable_fm\" parameter determines whether to enable fastmap during attach. If the value is non-zero, fastmap is enabled. Default value is 0.\n"
1582		      "Optional \"need_resv_pool\" parameter determines whether to reserve pool->max_size pebs during attach. If the value is non-zero, peb reservation is enabled. Default value is 0.\n"
1583		      "\n"
1584		      "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1585		      "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"
1586		      "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"
1587		      "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"
1588		      "example 5: mtd=1,0,0,5 mtd=2,0,0,6,1 - attach MTD device /dev/mtd1 to UBI 5 and disable fastmap; attach MTD device /dev/mtd2 to UBI 6 and enable fastmap.(only works when fastmap is enabled and fm_autoconvert=Y).\n"
1589		      "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1590#ifdef CONFIG_MTD_UBI_FASTMAP
1591module_param(fm_autoconvert, bool, 0644);
1592MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1593module_param(fm_debug, bool, 0);
1594MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1595#endif
1596MODULE_VERSION(__stringify(UBI_VERSION));
1597MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1598MODULE_AUTHOR("Artem Bityutskiy");
1599MODULE_LICENSE("GPL");
1600