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/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	*/
60	struct 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 */
70	static int mtd_devs;
71
72	/* MTD devices specification parameters */
73	static 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 */
76	static bool fm_autoconvert;
77	static bool fm_debug;
78	#endif
79
80	/* Slab cache for wear-leveling entries */
81	struct kmem_cache *ubi_wl_entry_slab;
82
83	/* UBI control character device */
84	static 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 */
91	static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
92
93	/* Serializes UBI devices creations and removals */
94	DEFINE_MUTEX(ubi_devices_mutex);
95
96	/* Protects @ubi_devices, @ubi->ref_count and @ubi->is_dead */
97	static DEFINE_SPINLOCK(ubi_devices_lock);
98
99	/* "Show" method for files in '/<sysfs>/class/ubi/' */
100	/* UBI version attribute ('/<sysfs>/class/ubi/version') */
101	static ssize_t version_show(const struct class *class, const struct class_attribute *attr,
102	char *buf)
103	{
104	return sprintf(buf, fmt: "%d\n", UBI_VERSION);
105	}
106	static CLASS_ATTR_RO(version);
107
108	static struct attribute *ubi_class_attrs[] = {
109	&class_attr_version.attr,
110	NULL,
111	};
112	ATTRIBUTE_GROUPS(ubi_class);
113
114	/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
115	const struct class ubi_class = {
116	.name = UBI_NAME_STR,
117	.class_groups = ubi_class_groups,
118	};
119
120	static 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') */
124	static struct device_attribute dev_eraseblock_size =
125	__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
126	static struct device_attribute dev_avail_eraseblocks =
127	__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
128	static struct device_attribute dev_total_eraseblocks =
129	__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
130	static struct device_attribute dev_volumes_count =
131	__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
132	static struct device_attribute dev_max_ec =
133	__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
134	static struct device_attribute dev_reserved_for_bad =
135	__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
136	static struct device_attribute dev_bad_peb_count =
137	__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
138	static struct device_attribute dev_max_vol_count =
139	__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
140	static struct device_attribute dev_min_io_size =
141	__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
142	static struct device_attribute dev_bgt_enabled =
143	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
144	static struct device_attribute dev_mtd_num =
145	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
146	static 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	*/
159	int 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, di: &nt.di);
165	ubi_do_get_volume_info(ubi, vol, vi: &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, fmt: "Unable to write a new fastmap: %i", ret);
175	}
176
177	return blocking_notifier_call_chain(nh: &ubi_notifiers, val: ntype, v: &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	*/
191	int 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, di: &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, vol: ubi->volumes[i], vi: &nt.vi);
209	if (nb)
210	nb->notifier_call(nb, ntype, &nt);
211	else
212	blocking_notifier_call_chain(nh: &ubi_notifiers, val: ntype,
213	v: &nt);
214	count += 1;
215	}
216	mutex_unlock(lock: &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	*/
230	int 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, ntype: 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	*/
258	struct ubi_device *ubi_get_device(int ubi_num)
259	{
260	struct ubi_device *ubi;
261
262	spin_lock(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(dev: &ubi->dev);
271	}
272	spin_unlock(lock: &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	*/
281	void ubi_put_device(struct ubi_device *ubi)
282	{
283	spin_lock(lock: &ubi_devices_lock);
284	ubi->ref_count -= 1;
285	put_device(dev: &ubi->dev);
286	spin_unlock(lock: &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	*/
296	struct ubi_device *ubi_get_by_major(int major)
297	{
298	int i;
299	struct ubi_device *ubi;
300
301	spin_lock(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(dev: &ubi->dev);
308	spin_unlock(lock: &ubi_devices_lock);
309	return ubi;
310	}
311	}
312	spin_unlock(lock: &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	*/
325	int ubi_major2num(int major)
326	{
327	int i, ubi_num = -ENODEV;
328
329	spin_lock(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(lock: &ubi_devices_lock);
339
340	return ubi_num;
341	}
342
343	/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
344	static 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, fmt: "%d\n", ubi->leb_size);
364	else if (attr == &dev_avail_eraseblocks)
365	ret = sprintf(buf, fmt: "%d\n", ubi->avail_pebs);
366	else if (attr == &dev_total_eraseblocks)
367	ret = sprintf(buf, fmt: "%d\n", ubi->good_peb_count);
368	else if (attr == &dev_volumes_count)
369	ret = sprintf(buf, fmt: "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
370	else if (attr == &dev_max_ec)
371	ret = sprintf(buf, fmt: "%d\n", ubi->max_ec);
372	else if (attr == &dev_reserved_for_bad)
373	ret = sprintf(buf, fmt: "%d\n", ubi->beb_rsvd_pebs);
374	else if (attr == &dev_bad_peb_count)
375	ret = sprintf(buf, fmt: "%d\n", ubi->bad_peb_count);
376	else if (attr == &dev_max_vol_count)
377	ret = sprintf(buf, fmt: "%d\n", ubi->vtbl_slots);
378	else if (attr == &dev_min_io_size)
379	ret = sprintf(buf, fmt: "%d\n", ubi->min_io_size);
380	else if (attr == &dev_bgt_enabled)
381	ret = sprintf(buf, fmt: "%d\n", ubi->thread_enabled);
382	else if (attr == &dev_mtd_num)
383	ret = sprintf(buf, fmt: "%d\n", ubi->mtd->index);
384	else if (attr == &dev_ro_mode)
385	ret = sprintf(buf, fmt: "%d\n", ubi->ro_mode);
386	else
387	ret = -EINVAL;
388
389	return ret;
390	}
391
392	static 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	};
407	ATTRIBUTE_GROUPS(ubi_dev);
408
409	static void dev_release(struct device *dev)
410	{
411	struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
412
413	kfree(objp: ubi);
414	}
415
416	/**
417	* kill_volumes - destroy all user volumes.
418	* @ubi: UBI device description object
419	*/
420	static 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, vol: 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	*/
440	static int uif_init(struct ubi_device *ubi)
441	{
442	int i, err;
443	dev_t dev;
444
445	sprintf(buf: 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, fmt: "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(dev: &ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
469	err = cdev_device_add(cdev: &ubi->cdev, dev: &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, vol: ubi->volumes[i]);
476	if (err) {
477	ubi_err(ubi, fmt: "cannot add volume %d", i);
478	ubi->volumes[i] = NULL;
479	goto out_volumes;
480	}
481	}
482
483	return 0;
484
485	out_volumes:
486	kill_volumes(ubi);
487	cdev_device_del(cdev: &ubi->cdev, dev: &ubi->dev);
488	out_unreg:
489	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
490	ubi_err(ubi, fmt: "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	*/
503	static void uif_close(struct ubi_device *ubi)
504	{
505	kill_volumes(ubi);
506	cdev_device_del(cdev: &ubi->cdev, dev: &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	*/
515	static 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(vol: ubi->volumes[i], NULL);
523	ubi_fastmap_destroy_checkmap(vol: ubi->volumes[i]);
524	kfree(objp: 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	*/
533	void ubi_free_all_volumes(struct ubi_device *ubi)
534	{
535	ubi_free_volumes_from(ubi, from: 0);
536	}
537
538	/**
539	* ubi_free_internal_volumes - free internal volumes.
540	* @ubi: UBI device description object
541	*/
542	void ubi_free_internal_volumes(struct ubi_device *ubi)
543	{
544	ubi_free_volumes_from(ubi, from: ubi->vtbl_slots);
545	}
546
547	static 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(mtd: ubi->mtd, ofs: 0, len: 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(mtd: ubi->mtd);
574	device_pebs = mtd_div_by_eb(sz: device_size, mtd: 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	*/
600	static 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, fmt: "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(sz: ubi->mtd->size, mtd: ubi->mtd);
629	ubi->flash_size = ubi->mtd->size;
630
631	if (mtd_can_have_bb(mtd: 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(n: ubi->min_io_size)) {
648	ubi_err(ubi, fmt: "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(n: ubi->max_write_size)) {
665	ubi_err(ubi, fmt: "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, fmt: "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, fmt: "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, fmt: "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, fmt: "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, fmt: "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	*/
780	static 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, fmt: "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, idx: vol_id, vtbl_rec: &vtbl_rec);
807	if (err)
808	ubi_err(ubi, fmt: "cannot clean auto-resize flag for volume %d",
809	vol_id);
810	} else {
811	desc.vol = vol;
812	err = ubi_resize_volume(desc: &desc,
813	reserved_pebs: old_reserved_pebs + ubi->avail_pebs);
814	if (err)
815	ubi_err(ubi, fmt: "cannot auto-resize volume %d",
816	vol_id);
817	}
818
819	if (err)
820	return err;
821
822	ubi_msg(ubi, fmt: "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	*/
849	int 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(dev: &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(sz: ubi->mtd->size, mtd: ubi->mtd)
968	<= UBI_FM_MAX_START) {
969	ubi_err(ubi, fmt: "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, fmt: "default fastmap pool size: %d", ubi->fm_pool.max_size);
975	ubi_msg(ubi, fmt: "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, fmt: "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, force_scan: disable_fm ? 1 : 0);
1005	if (err) {
1006	ubi_err(ubi, fmt: "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, vol_id: 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(ptr: ubi->bgt_thread)) {
1027	err = PTR_ERR(ptr: ubi->bgt_thread);
1028	ubi_err(ubi, fmt: "cannot spawn \"%s\", error %d",
1029	ubi->bgt_name, err);
1030	goto out_debugfs;
1031	}
1032
1033	ubi_msg(ubi, fmt: "attached mtd%d (name \"%s\", size %llu MiB)",
1034	mtd->index, mtd->name, ubi->flash_size >> 20);
1035	ubi_msg(ubi, fmt: "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, fmt: "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, fmt: "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, fmt: "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, fmt: "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, fmt: "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, fmt: "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(lock: &ubi->wl_lock);
1057	ubi->thread_enabled = 1;
1058	wake_up_process(tsk: ubi->bgt_thread);
1059	spin_unlock(lock: &ubi->wl_lock);
1060
1061	ubi_devices[ubi_num] = ubi;
1062	ubi_notify_all(ubi, ntype: UBI_VOLUME_ADDED, NULL);
1063	return ubi_num;
1064
1065	out_debugfs:
1066	ubi_debugfs_exit_dev(ubi);
1067	out_uif:
1068	uif_close(ubi);
1069	out_detach:
1070	ubi_wl_close(ubi);
1071	ubi_free_all_volumes(ubi);
1072	vfree(addr: ubi->vtbl);
1073	out_free:
1074	vfree(addr: ubi->peb_buf);
1075	vfree(addr: ubi->fm_buf);
1076	put_device(dev: &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	*/
1093	int 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(lock: &ubi_devices_lock);
1105	ubi->ref_count -= 1;
1106	if (ubi->ref_count) {
1107	if (!anyway) {
1108	spin_unlock(lock: &ubi_devices_lock);
1109	return -EBUSY;
1110	}
1111	/* This may only happen if there is a bug */
1112	ubi_err(ubi, fmt: "%s reference count %d, destroy anyway",
1113	ubi->ubi_name, ubi->ref_count);
1114	}
1115	ubi->is_dead = true;
1116	spin_unlock(lock: &ubi_devices_lock);
1117
1118	ubi_notify_all(ubi, ntype: UBI_VOLUME_SHUTDOWN, NULL);
1119
1120	spin_lock(lock: &ubi_devices_lock);
1121	put_device(dev: &ubi->dev);
1122	ubi_devices[ubi_num] = NULL;
1123	spin_unlock(lock: &ubi_devices_lock);
1124
1125	ubi_assert(ubi_num == ubi->ubi_num);
1126	ubi_notify_all(ubi, ntype: UBI_VOLUME_REMOVED, NULL);
1127	ubi_msg(ubi, fmt: "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(k: ubi->bgt_thread);
1142
1143	#ifdef CONFIG_MTD_UBI_FASTMAP
1144	cancel_work_sync(work: &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(addr: ubi->vtbl);
1152	vfree(addr: ubi->peb_buf);
1153	vfree(addr: ubi->fm_buf);
1154	ubi_msg(ubi, fmt: "mtd%d is detached", ubi->mtd->index);
1155	put_mtd_device(mtd: ubi->mtd);
1156	put_device(dev: &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	*/
1168	static 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(error: 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(error: 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(error: -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(error: -EINVAL);
1196
1197	return get_mtd_device(NULL, num: 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	*/
1210	static 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(name: mtd_dev);
1223	if (PTR_ERR(ptr: 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, num: mtd_num);
1228
1229	return mtd;
1230	}
1231
1232	static 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(device: 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(lock: &ubi_devices_mutex, SINGLE_DEPTH_NESTING);
1250	err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO, vid_hdr_offset: 0, max_beb_per1024: 0, disable_fm: false, need_resv_pool: false);
1251	mutex_unlock(lock: &ubi_devices_mutex);
1252	if (err < 0)
1253	__put_mtd_device(mtd);
1254	}
1255
1256	static void ubi_notify_remove(struct mtd_info *mtd)
1257	{
1258	/* do nothing for now */
1259	}
1260
1261	static struct mtd_notifier ubi_mtd_notifier = {
1262	.add = ubi_notify_add,
1263	.remove = ubi_notify_remove,
1264	};
1265
1266	static 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(mtd_dev: p->name);
1278	if (IS_ERR(ptr: mtd)) {
1279	err = PTR_ERR(ptr: 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, ubi_num: p->ubi_num,
1290	vid_hdr_offset: p->vid_hdr_offs, max_beb_per1024: p->max_beb_per1024,
1291	disable_fm: p->enable_fm == 0,
1292	need_resv_pool: p->need_resv_pool != 0);
1293	mutex_unlock(lock: &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
1319	out_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_num: ubi_devices[k]->ubi_num, anyway: 1);
1324	mutex_unlock(lock: &ubi_devices_mutex);
1325	}
1326	return err;
1327	}
1328	#ifndef CONFIG_MTD_UBI_MODULE
1329	late_initcall(ubi_init_attach);
1330	#endif
1331
1332	static 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(class: &ubi_class);
1348	if (err < 0)
1349	return err;
1350
1351	err = misc_register(misc: &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_debugfs;
1376	}
1377
1378	register_mtd_user(new: &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
1388	out_mtd_notifier:
1389	unregister_mtd_user(old: &ubi_mtd_notifier);
1390	ubiblock_exit();
1391	out_debugfs:
1392	ubi_debugfs_exit();
1393	out_slab:
1394	kmem_cache_destroy(s: ubi_wl_entry_slab);
1395	out_dev_unreg:
1396	misc_deregister(misc: &ubi_ctrl_cdev);
1397	out:
1398	class_unregister(class: &ubi_class);
1399	pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1400	return err;
1401	}
1402	device_initcall(ubi_init);
1403
1404
1405	static void __exit ubi_exit(void)
1406	{
1407	int i;
1408
1409	ubiblock_exit();
1410	unregister_mtd_user(old: &ubi_mtd_notifier);
1411
1412	for (i = 0; i < UBI_MAX_DEVICES; i++)
1413	if (ubi_devices[i]) {
1414	mutex_lock(&ubi_devices_mutex);
1415	ubi_detach_mtd_dev(ubi_num: ubi_devices[i]->ubi_num, anyway: 1);
1416	mutex_unlock(lock: &ubi_devices_mutex);
1417	}
1418	ubi_debugfs_exit();
1419	kmem_cache_destroy(s: ubi_wl_entry_slab);
1420	misc_deregister(misc: &ubi_ctrl_cdev);
1421	class_unregister(class: &ubi_class);
1422	}
1423	module_exit(ubi_exit);
1424
1425	/**
1426	* bytes_str_to_int - convert a number of bytes string into an integer.
1427	* @str: the string to convert
1428	*
1429	* This function returns positive resulting integer in case of success and a
1430	* negative error code in case of failure.
1431	*/
1432	static int bytes_str_to_int(const char *str)
1433	{
1434	char *endp;
1435	unsigned long result;
1436
1437	result = simple_strtoul(str, &endp, 0);
1438	if (str == endp || result >= INT_MAX) {
1439	pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1440	return -EINVAL;
1441	}
1442
1443	switch (*endp) {
1444	case 'G':
1445	result *= 1024;
1446	fallthrough;
1447	case 'M':
1448	result *= 1024;
1449	fallthrough;
1450	case 'K':
1451	result *= 1024;
1452	break;
1453	case '\0':
1454	break;
1455	default:
1456	pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1457	return -EINVAL;
1458	}
1459
1460	return result;
1461	}
1462
1463	/**
1464	* ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1465	* @val: the parameter value to parse
1466	* @kp: not used
1467	*
1468	* This function returns zero in case of success and a negative error code in
1469	* case of error.
1470	*/
1471	static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1472	{
1473	int i, len;
1474	struct mtd_dev_param *p;
1475	char buf[MTD_PARAM_LEN_MAX];
1476	char *pbuf = &buf[0];
1477	char *tokens[MTD_PARAM_MAX_COUNT], *token;
1478
1479	if (!val)
1480	return -EINVAL;
1481
1482	if (mtd_devs == UBI_MAX_DEVICES) {
1483	pr_err("UBI error: too many parameters, max. is %d\n",
1484	UBI_MAX_DEVICES);
1485	return -EINVAL;
1486	}
1487
1488	len = strnlen(p: val, MTD_PARAM_LEN_MAX);
1489	if (len == MTD_PARAM_LEN_MAX) {
1490	pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1491	val, MTD_PARAM_LEN_MAX);
1492	return -EINVAL;
1493	}
1494
1495	if (len == 0) {
1496	pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1497	return 0;
1498	}
1499
1500	strcpy(p: buf, q: val);
1501
1502	/* Get rid of the final newline */
1503	if (buf[len - 1] == '\n')
1504	buf[len - 1] = '\0';
1505
1506	for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1507	tokens[i] = strsep(&pbuf, ",");
1508
1509	if (pbuf) {
1510	pr_err("UBI error: too many arguments at \"%s\"\n", val);
1511	return -EINVAL;
1512	}
1513
1514	p = &mtd_dev_param[mtd_devs];
1515	strcpy(p: &p->name[0], q: tokens[0]);
1516
1517	token = tokens[1];
1518	if (token) {
1519	p->vid_hdr_offs = bytes_str_to_int(str: token);
1520
1521	if (p->vid_hdr_offs < 0)
1522	return p->vid_hdr_offs;
1523	}
1524
1525	token = tokens[2];
1526	if (token) {
1527	int err = kstrtoint(s: token, base: 10, res: &p->max_beb_per1024);
1528
1529	if (err) {
1530	pr_err("UBI error: bad value for max_beb_per1024 parameter: %s\n",
1531	token);
1532	return -EINVAL;
1533	}
1534	}
1535
1536	token = tokens[3];
1537	if (token) {
1538	int err = kstrtoint(s: token, base: 10, res: &p->ubi_num);
1539
1540	if (err || p->ubi_num < UBI_DEV_NUM_AUTO) {
1541	pr_err("UBI error: bad value for ubi_num parameter: %s\n",
1542	token);
1543	return -EINVAL;
1544	}
1545	} else
1546	p->ubi_num = UBI_DEV_NUM_AUTO;
1547
1548	token = tokens[4];
1549	if (token) {
1550	int err = kstrtoint(s: token, base: 10, res: &p->enable_fm);
1551
1552	if (err) {
1553	pr_err("UBI error: bad value for enable_fm parameter: %s\n",
1554	token);
1555	return -EINVAL;
1556	}
1557	} else
1558	p->enable_fm = 0;
1559
1560	token = tokens[5];
1561	if (token) {
1562	int err = kstrtoint(s: token, base: 10, res: &p->need_resv_pool);
1563
1564	if (err) {
1565	pr_err("UBI error: bad value for need_resv_pool parameter: %s\n",
1566	token);
1567	return -EINVAL;
1568	}
1569	} else
1570	p->need_resv_pool = 0;
1571
1572	mtd_devs += 1;
1573	return 0;
1574	}
1575
1576	module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1577	MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1578	"Multiple \"mtd\" parameters may be specified.\n"
1579	"MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1580	"Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1581	"Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1582	__stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1583	"Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1584	"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"
1585	"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"
1586	"\n"
1587	"Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1588	"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"
1589	"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"
1590	"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"
1591	"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"
1592	"\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1593	#ifdef CONFIG_MTD_UBI_FASTMAP
1594	module_param(fm_autoconvert, bool, 0644);
1595	MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1596	module_param(fm_debug, bool, 0);
1597	MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1598	#endif
1599	MODULE_VERSION(__stringify(UBI_VERSION));
1600	MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1601	MODULE_AUTHOR("Artem Bityutskiy");
1602	MODULE_LICENSE("GPL");
1603