xref: /openbmc/linux/drivers/mtd/ubi/build.c (revision feac8c8b)
1 /*
2  * Copyright (c) International Business Machines Corp., 2006
3  * Copyright (c) Nokia Corporation, 2007
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13  * the GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  *
19  * Author: Artem Bityutskiy (Битюцкий Артём),
20  *         Frank Haverkamp
21  */
22 
23 /*
24  * This file includes UBI initialization and building of UBI devices.
25  *
26  * When UBI is initialized, it attaches all the MTD devices specified as the
27  * module load parameters or the kernel boot parameters. If MTD devices were
28  * specified, UBI does not attach any MTD device, but it is possible to do
29  * later using the "UBI control device".
30  */
31 
32 #include <linux/err.h>
33 #include <linux/module.h>
34 #include <linux/moduleparam.h>
35 #include <linux/stringify.h>
36 #include <linux/namei.h>
37 #include <linux/stat.h>
38 #include <linux/miscdevice.h>
39 #include <linux/mtd/partitions.h>
40 #include <linux/log2.h>
41 #include <linux/kthread.h>
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
44 #include <linux/major.h>
45 #include "ubi.h"
46 
47 /* Maximum length of the 'mtd=' parameter */
48 #define MTD_PARAM_LEN_MAX 64
49 
50 /* Maximum number of comma-separated items in the 'mtd=' parameter */
51 #define MTD_PARAM_MAX_COUNT 4
52 
53 /* Maximum value for the number of bad PEBs per 1024 PEBs */
54 #define MAX_MTD_UBI_BEB_LIMIT 768
55 
56 #ifdef CONFIG_MTD_UBI_MODULE
57 #define ubi_is_module() 1
58 #else
59 #define ubi_is_module() 0
60 #endif
61 
62 /**
63  * struct mtd_dev_param - MTD device parameter description data structure.
64  * @name: MTD character device node path, MTD device name, or MTD device number
65  *        string
66  * @vid_hdr_offs: VID header offset
67  * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
68  */
69 struct mtd_dev_param {
70 	char name[MTD_PARAM_LEN_MAX];
71 	int ubi_num;
72 	int vid_hdr_offs;
73 	int max_beb_per1024;
74 };
75 
76 /* Numbers of elements set in the @mtd_dev_param array */
77 static int mtd_devs;
78 
79 /* MTD devices specification parameters */
80 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
81 #ifdef CONFIG_MTD_UBI_FASTMAP
82 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
83 static bool fm_autoconvert;
84 static bool fm_debug;
85 #endif
86 
87 /* Slab cache for wear-leveling entries */
88 struct kmem_cache *ubi_wl_entry_slab;
89 
90 /* UBI control character device */
91 static struct miscdevice ubi_ctrl_cdev = {
92 	.minor = MISC_DYNAMIC_MINOR,
93 	.name = "ubi_ctrl",
94 	.fops = &ubi_ctrl_cdev_operations,
95 };
96 
97 /* All UBI devices in system */
98 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
99 
100 /* Serializes UBI devices creations and removals */
101 DEFINE_MUTEX(ubi_devices_mutex);
102 
103 /* Protects @ubi_devices and @ubi->ref_count */
104 static DEFINE_SPINLOCK(ubi_devices_lock);
105 
106 /* "Show" method for files in '/<sysfs>/class/ubi/' */
107 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
108 static ssize_t version_show(struct class *class, struct class_attribute *attr,
109 			    char *buf)
110 {
111 	return sprintf(buf, "%d\n", UBI_VERSION);
112 }
113 static CLASS_ATTR_RO(version);
114 
115 static struct attribute *ubi_class_attrs[] = {
116 	&class_attr_version.attr,
117 	NULL,
118 };
119 ATTRIBUTE_GROUPS(ubi_class);
120 
121 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
122 struct class ubi_class = {
123 	.name		= UBI_NAME_STR,
124 	.owner		= THIS_MODULE,
125 	.class_groups	= ubi_class_groups,
126 };
127 
128 static ssize_t dev_attribute_show(struct device *dev,
129 				  struct device_attribute *attr, char *buf);
130 
131 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
132 static struct device_attribute dev_eraseblock_size =
133 	__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
134 static struct device_attribute dev_avail_eraseblocks =
135 	__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
136 static struct device_attribute dev_total_eraseblocks =
137 	__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
138 static struct device_attribute dev_volumes_count =
139 	__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
140 static struct device_attribute dev_max_ec =
141 	__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
142 static struct device_attribute dev_reserved_for_bad =
143 	__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
144 static struct device_attribute dev_bad_peb_count =
145 	__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
146 static struct device_attribute dev_max_vol_count =
147 	__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
148 static struct device_attribute dev_min_io_size =
149 	__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
150 static struct device_attribute dev_bgt_enabled =
151 	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
152 static struct device_attribute dev_mtd_num =
153 	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
154 static struct device_attribute dev_ro_mode =
155 	__ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
156 
157 /**
158  * ubi_volume_notify - send a volume change notification.
159  * @ubi: UBI device description object
160  * @vol: volume description object of the changed volume
161  * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
162  *
163  * This is a helper function which notifies all subscribers about a volume
164  * change event (creation, removal, re-sizing, re-naming, updating). Returns
165  * zero in case of success and a negative error code in case of failure.
166  */
167 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
168 {
169 	int ret;
170 	struct ubi_notification nt;
171 
172 	ubi_do_get_device_info(ubi, &nt.di);
173 	ubi_do_get_volume_info(ubi, vol, &nt.vi);
174 
175 	switch (ntype) {
176 	case UBI_VOLUME_ADDED:
177 	case UBI_VOLUME_REMOVED:
178 	case UBI_VOLUME_RESIZED:
179 	case UBI_VOLUME_RENAMED:
180 		ret = ubi_update_fastmap(ubi);
181 		if (ret)
182 			ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
183 	}
184 
185 	return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
186 }
187 
188 /**
189  * ubi_notify_all - send a notification to all volumes.
190  * @ubi: UBI device description object
191  * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
192  * @nb: the notifier to call
193  *
194  * This function walks all volumes of UBI device @ubi and sends the @ntype
195  * notification for each volume. If @nb is %NULL, then all registered notifiers
196  * are called, otherwise only the @nb notifier is called. Returns the number of
197  * sent notifications.
198  */
199 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
200 {
201 	struct ubi_notification nt;
202 	int i, count = 0;
203 
204 	ubi_do_get_device_info(ubi, &nt.di);
205 
206 	mutex_lock(&ubi->device_mutex);
207 	for (i = 0; i < ubi->vtbl_slots; i++) {
208 		/*
209 		 * Since the @ubi->device is locked, and we are not going to
210 		 * change @ubi->volumes, we do not have to lock
211 		 * @ubi->volumes_lock.
212 		 */
213 		if (!ubi->volumes[i])
214 			continue;
215 
216 		ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
217 		if (nb)
218 			nb->notifier_call(nb, ntype, &nt);
219 		else
220 			blocking_notifier_call_chain(&ubi_notifiers, ntype,
221 						     &nt);
222 		count += 1;
223 	}
224 	mutex_unlock(&ubi->device_mutex);
225 
226 	return count;
227 }
228 
229 /**
230  * ubi_enumerate_volumes - send "add" notification for all existing volumes.
231  * @nb: the notifier to call
232  *
233  * This function walks all UBI devices and volumes and sends the
234  * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
235  * registered notifiers are called, otherwise only the @nb notifier is called.
236  * Returns the number of sent notifications.
237  */
238 int ubi_enumerate_volumes(struct notifier_block *nb)
239 {
240 	int i, count = 0;
241 
242 	/*
243 	 * Since the @ubi_devices_mutex is locked, and we are not going to
244 	 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
245 	 */
246 	for (i = 0; i < UBI_MAX_DEVICES; i++) {
247 		struct ubi_device *ubi = ubi_devices[i];
248 
249 		if (!ubi)
250 			continue;
251 		count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
252 	}
253 
254 	return count;
255 }
256 
257 /**
258  * ubi_get_device - get UBI device.
259  * @ubi_num: UBI device number
260  *
261  * This function returns UBI device description object for UBI device number
262  * @ubi_num, or %NULL if the device does not exist. This function increases the
263  * device reference count to prevent removal of the device. In other words, the
264  * device cannot be removed if its reference count is not zero.
265  */
266 struct ubi_device *ubi_get_device(int ubi_num)
267 {
268 	struct ubi_device *ubi;
269 
270 	spin_lock(&ubi_devices_lock);
271 	ubi = ubi_devices[ubi_num];
272 	if (ubi) {
273 		ubi_assert(ubi->ref_count >= 0);
274 		ubi->ref_count += 1;
275 		get_device(&ubi->dev);
276 	}
277 	spin_unlock(&ubi_devices_lock);
278 
279 	return ubi;
280 }
281 
282 /**
283  * ubi_put_device - drop an UBI device reference.
284  * @ubi: UBI device description object
285  */
286 void ubi_put_device(struct ubi_device *ubi)
287 {
288 	spin_lock(&ubi_devices_lock);
289 	ubi->ref_count -= 1;
290 	put_device(&ubi->dev);
291 	spin_unlock(&ubi_devices_lock);
292 }
293 
294 /**
295  * ubi_get_by_major - get UBI device by character device major number.
296  * @major: major number
297  *
298  * This function is similar to 'ubi_get_device()', but it searches the device
299  * by its major number.
300  */
301 struct ubi_device *ubi_get_by_major(int major)
302 {
303 	int i;
304 	struct ubi_device *ubi;
305 
306 	spin_lock(&ubi_devices_lock);
307 	for (i = 0; i < UBI_MAX_DEVICES; i++) {
308 		ubi = ubi_devices[i];
309 		if (ubi && MAJOR(ubi->cdev.dev) == major) {
310 			ubi_assert(ubi->ref_count >= 0);
311 			ubi->ref_count += 1;
312 			get_device(&ubi->dev);
313 			spin_unlock(&ubi_devices_lock);
314 			return ubi;
315 		}
316 	}
317 	spin_unlock(&ubi_devices_lock);
318 
319 	return NULL;
320 }
321 
322 /**
323  * ubi_major2num - get UBI device number by character device major number.
324  * @major: major number
325  *
326  * This function searches UBI device number object by its major number. If UBI
327  * device was not found, this function returns -ENODEV, otherwise the UBI device
328  * number is returned.
329  */
330 int ubi_major2num(int major)
331 {
332 	int i, ubi_num = -ENODEV;
333 
334 	spin_lock(&ubi_devices_lock);
335 	for (i = 0; i < UBI_MAX_DEVICES; i++) {
336 		struct ubi_device *ubi = ubi_devices[i];
337 
338 		if (ubi && MAJOR(ubi->cdev.dev) == major) {
339 			ubi_num = ubi->ubi_num;
340 			break;
341 		}
342 	}
343 	spin_unlock(&ubi_devices_lock);
344 
345 	return ubi_num;
346 }
347 
348 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
349 static ssize_t dev_attribute_show(struct device *dev,
350 				  struct device_attribute *attr, char *buf)
351 {
352 	ssize_t ret;
353 	struct ubi_device *ubi;
354 
355 	/*
356 	 * The below code looks weird, but it actually makes sense. We get the
357 	 * UBI device reference from the contained 'struct ubi_device'. But it
358 	 * is unclear if the device was removed or not yet. Indeed, if the
359 	 * device was removed before we increased its reference count,
360 	 * 'ubi_get_device()' will return -ENODEV and we fail.
361 	 *
362 	 * Remember, 'struct ubi_device' is freed in the release function, so
363 	 * we still can use 'ubi->ubi_num'.
364 	 */
365 	ubi = container_of(dev, struct ubi_device, dev);
366 	ubi = ubi_get_device(ubi->ubi_num);
367 	if (!ubi)
368 		return -ENODEV;
369 
370 	if (attr == &dev_eraseblock_size)
371 		ret = sprintf(buf, "%d\n", ubi->leb_size);
372 	else if (attr == &dev_avail_eraseblocks)
373 		ret = sprintf(buf, "%d\n", ubi->avail_pebs);
374 	else if (attr == &dev_total_eraseblocks)
375 		ret = sprintf(buf, "%d\n", ubi->good_peb_count);
376 	else if (attr == &dev_volumes_count)
377 		ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
378 	else if (attr == &dev_max_ec)
379 		ret = sprintf(buf, "%d\n", ubi->max_ec);
380 	else if (attr == &dev_reserved_for_bad)
381 		ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
382 	else if (attr == &dev_bad_peb_count)
383 		ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
384 	else if (attr == &dev_max_vol_count)
385 		ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
386 	else if (attr == &dev_min_io_size)
387 		ret = sprintf(buf, "%d\n", ubi->min_io_size);
388 	else if (attr == &dev_bgt_enabled)
389 		ret = sprintf(buf, "%d\n", ubi->thread_enabled);
390 	else if (attr == &dev_mtd_num)
391 		ret = sprintf(buf, "%d\n", ubi->mtd->index);
392 	else if (attr == &dev_ro_mode)
393 		ret = sprintf(buf, "%d\n", ubi->ro_mode);
394 	else
395 		ret = -EINVAL;
396 
397 	ubi_put_device(ubi);
398 	return ret;
399 }
400 
401 static struct attribute *ubi_dev_attrs[] = {
402 	&dev_eraseblock_size.attr,
403 	&dev_avail_eraseblocks.attr,
404 	&dev_total_eraseblocks.attr,
405 	&dev_volumes_count.attr,
406 	&dev_max_ec.attr,
407 	&dev_reserved_for_bad.attr,
408 	&dev_bad_peb_count.attr,
409 	&dev_max_vol_count.attr,
410 	&dev_min_io_size.attr,
411 	&dev_bgt_enabled.attr,
412 	&dev_mtd_num.attr,
413 	&dev_ro_mode.attr,
414 	NULL
415 };
416 ATTRIBUTE_GROUPS(ubi_dev);
417 
418 static void dev_release(struct device *dev)
419 {
420 	struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
421 
422 	kfree(ubi);
423 }
424 
425 /**
426  * kill_volumes - destroy all user volumes.
427  * @ubi: UBI device description object
428  */
429 static void kill_volumes(struct ubi_device *ubi)
430 {
431 	int i;
432 
433 	for (i = 0; i < ubi->vtbl_slots; i++)
434 		if (ubi->volumes[i])
435 			ubi_free_volume(ubi, ubi->volumes[i]);
436 }
437 
438 /**
439  * uif_init - initialize user interfaces for an UBI device.
440  * @ubi: UBI device description object
441  *
442  * This function initializes various user interfaces for an UBI device. If the
443  * initialization fails at an early stage, this function frees all the
444  * resources it allocated, returns an error.
445  *
446  * This function returns zero in case of success and a negative error code in
447  * case of failure.
448  */
449 static int uif_init(struct ubi_device *ubi)
450 {
451 	int i, err;
452 	dev_t dev;
453 
454 	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
455 
456 	/*
457 	 * Major numbers for the UBI character devices are allocated
458 	 * dynamically. Major numbers of volume character devices are
459 	 * equivalent to ones of the corresponding UBI character device. Minor
460 	 * numbers of UBI character devices are 0, while minor numbers of
461 	 * volume character devices start from 1. Thus, we allocate one major
462 	 * number and ubi->vtbl_slots + 1 minor numbers.
463 	 */
464 	err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
465 	if (err) {
466 		ubi_err(ubi, "cannot register UBI character devices");
467 		return err;
468 	}
469 
470 	ubi->dev.devt = dev;
471 
472 	ubi_assert(MINOR(dev) == 0);
473 	cdev_init(&ubi->cdev, &ubi_cdev_operations);
474 	dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
475 	ubi->cdev.owner = THIS_MODULE;
476 
477 	dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
478 	err = cdev_device_add(&ubi->cdev, &ubi->dev);
479 	if (err)
480 		goto out_unreg;
481 
482 	for (i = 0; i < ubi->vtbl_slots; i++)
483 		if (ubi->volumes[i]) {
484 			err = ubi_add_volume(ubi, ubi->volumes[i]);
485 			if (err) {
486 				ubi_err(ubi, "cannot add volume %d", i);
487 				goto out_volumes;
488 			}
489 		}
490 
491 	return 0;
492 
493 out_volumes:
494 	kill_volumes(ubi);
495 	cdev_device_del(&ubi->cdev, &ubi->dev);
496 out_unreg:
497 	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
498 	ubi_err(ubi, "cannot initialize UBI %s, error %d",
499 		ubi->ubi_name, err);
500 	return err;
501 }
502 
503 /**
504  * uif_close - close user interfaces for an UBI device.
505  * @ubi: UBI device description object
506  *
507  * Note, since this function un-registers UBI volume device objects (@vol->dev),
508  * the memory allocated voe the volumes is freed as well (in the release
509  * function).
510  */
511 static void uif_close(struct ubi_device *ubi)
512 {
513 	kill_volumes(ubi);
514 	cdev_device_del(&ubi->cdev, &ubi->dev);
515 	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
516 }
517 
518 /**
519  * ubi_free_internal_volumes - free internal volumes.
520  * @ubi: UBI device description object
521  */
522 void ubi_free_internal_volumes(struct ubi_device *ubi)
523 {
524 	int i;
525 
526 	for (i = ubi->vtbl_slots;
527 	     i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
528 		ubi_eba_replace_table(ubi->volumes[i], NULL);
529 		kfree(ubi->volumes[i]);
530 	}
531 }
532 
533 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
534 {
535 	int limit, device_pebs;
536 	uint64_t device_size;
537 
538 	if (!max_beb_per1024) {
539 		/*
540 		 * Since max_beb_per1024 has not been set by the user in either
541 		 * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
542 		 * limit if it is supported by the device.
543 		 */
544 		limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
545 		if (limit < 0)
546 			return 0;
547 		return limit;
548 	}
549 
550 	/*
551 	 * Here we are using size of the entire flash chip and
552 	 * not just the MTD partition size because the maximum
553 	 * number of bad eraseblocks is a percentage of the
554 	 * whole device and bad eraseblocks are not fairly
555 	 * distributed over the flash chip. So the worst case
556 	 * is that all the bad eraseblocks of the chip are in
557 	 * the MTD partition we are attaching (ubi->mtd).
558 	 */
559 	device_size = mtd_get_device_size(ubi->mtd);
560 	device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
561 	limit = mult_frac(device_pebs, max_beb_per1024, 1024);
562 
563 	/* Round it up */
564 	if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
565 		limit += 1;
566 
567 	return limit;
568 }
569 
570 /**
571  * io_init - initialize I/O sub-system for a given UBI device.
572  * @ubi: UBI device description object
573  * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
574  *
575  * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
576  * assumed:
577  *   o EC header is always at offset zero - this cannot be changed;
578  *   o VID header starts just after the EC header at the closest address
579  *     aligned to @io->hdrs_min_io_size;
580  *   o data starts just after the VID header at the closest address aligned to
581  *     @io->min_io_size
582  *
583  * This function returns zero in case of success and a negative error code in
584  * case of failure.
585  */
586 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
587 {
588 	dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
589 	dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
590 
591 	if (ubi->mtd->numeraseregions != 0) {
592 		/*
593 		 * Some flashes have several erase regions. Different regions
594 		 * may have different eraseblock size and other
595 		 * characteristics. It looks like mostly multi-region flashes
596 		 * have one "main" region and one or more small regions to
597 		 * store boot loader code or boot parameters or whatever. I
598 		 * guess we should just pick the largest region. But this is
599 		 * not implemented.
600 		 */
601 		ubi_err(ubi, "multiple regions, not implemented");
602 		return -EINVAL;
603 	}
604 
605 	if (ubi->vid_hdr_offset < 0)
606 		return -EINVAL;
607 
608 	/*
609 	 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
610 	 * physical eraseblocks maximum.
611 	 */
612 
613 	ubi->peb_size   = ubi->mtd->erasesize;
614 	ubi->peb_count  = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
615 	ubi->flash_size = ubi->mtd->size;
616 
617 	if (mtd_can_have_bb(ubi->mtd)) {
618 		ubi->bad_allowed = 1;
619 		ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
620 	}
621 
622 	if (ubi->mtd->type == MTD_NORFLASH) {
623 		ubi_assert(ubi->mtd->writesize == 1);
624 		ubi->nor_flash = 1;
625 	}
626 
627 	ubi->min_io_size = ubi->mtd->writesize;
628 	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
629 
630 	/*
631 	 * Make sure minimal I/O unit is power of 2. Note, there is no
632 	 * fundamental reason for this assumption. It is just an optimization
633 	 * which allows us to avoid costly division operations.
634 	 */
635 	if (!is_power_of_2(ubi->min_io_size)) {
636 		ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
637 			ubi->min_io_size);
638 		return -EINVAL;
639 	}
640 
641 	ubi_assert(ubi->hdrs_min_io_size > 0);
642 	ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
643 	ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
644 
645 	ubi->max_write_size = ubi->mtd->writebufsize;
646 	/*
647 	 * Maximum write size has to be greater or equivalent to min. I/O
648 	 * size, and be multiple of min. I/O size.
649 	 */
650 	if (ubi->max_write_size < ubi->min_io_size ||
651 	    ubi->max_write_size % ubi->min_io_size ||
652 	    !is_power_of_2(ubi->max_write_size)) {
653 		ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
654 			ubi->max_write_size, ubi->min_io_size);
655 		return -EINVAL;
656 	}
657 
658 	/* Calculate default aligned sizes of EC and VID headers */
659 	ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
660 	ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
661 
662 	dbg_gen("min_io_size      %d", ubi->min_io_size);
663 	dbg_gen("max_write_size   %d", ubi->max_write_size);
664 	dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
665 	dbg_gen("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
666 	dbg_gen("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
667 
668 	if (ubi->vid_hdr_offset == 0)
669 		/* Default offset */
670 		ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
671 				      ubi->ec_hdr_alsize;
672 	else {
673 		ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
674 						~(ubi->hdrs_min_io_size - 1);
675 		ubi->vid_hdr_shift = ubi->vid_hdr_offset -
676 						ubi->vid_hdr_aloffset;
677 	}
678 
679 	/* Similar for the data offset */
680 	ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
681 	ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
682 
683 	dbg_gen("vid_hdr_offset   %d", ubi->vid_hdr_offset);
684 	dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
685 	dbg_gen("vid_hdr_shift    %d", ubi->vid_hdr_shift);
686 	dbg_gen("leb_start        %d", ubi->leb_start);
687 
688 	/* The shift must be aligned to 32-bit boundary */
689 	if (ubi->vid_hdr_shift % 4) {
690 		ubi_err(ubi, "unaligned VID header shift %d",
691 			ubi->vid_hdr_shift);
692 		return -EINVAL;
693 	}
694 
695 	/* Check sanity */
696 	if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
697 	    ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
698 	    ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
699 	    ubi->leb_start & (ubi->min_io_size - 1)) {
700 		ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
701 			ubi->vid_hdr_offset, ubi->leb_start);
702 		return -EINVAL;
703 	}
704 
705 	/*
706 	 * Set maximum amount of physical erroneous eraseblocks to be 10%.
707 	 * Erroneous PEB are those which have read errors.
708 	 */
709 	ubi->max_erroneous = ubi->peb_count / 10;
710 	if (ubi->max_erroneous < 16)
711 		ubi->max_erroneous = 16;
712 	dbg_gen("max_erroneous    %d", ubi->max_erroneous);
713 
714 	/*
715 	 * It may happen that EC and VID headers are situated in one minimal
716 	 * I/O unit. In this case we can only accept this UBI image in
717 	 * read-only mode.
718 	 */
719 	if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
720 		ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
721 		ubi->ro_mode = 1;
722 	}
723 
724 	ubi->leb_size = ubi->peb_size - ubi->leb_start;
725 
726 	if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
727 		ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
728 			ubi->mtd->index);
729 		ubi->ro_mode = 1;
730 	}
731 
732 	/*
733 	 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
734 	 * unfortunately, MTD does not provide this information. We should loop
735 	 * over all physical eraseblocks and invoke mtd->block_is_bad() for
736 	 * each physical eraseblock. So, we leave @ubi->bad_peb_count
737 	 * uninitialized so far.
738 	 */
739 
740 	return 0;
741 }
742 
743 /**
744  * autoresize - re-size the volume which has the "auto-resize" flag set.
745  * @ubi: UBI device description object
746  * @vol_id: ID of the volume to re-size
747  *
748  * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
749  * the volume table to the largest possible size. See comments in ubi-header.h
750  * for more description of the flag. Returns zero in case of success and a
751  * negative error code in case of failure.
752  */
753 static int autoresize(struct ubi_device *ubi, int vol_id)
754 {
755 	struct ubi_volume_desc desc;
756 	struct ubi_volume *vol = ubi->volumes[vol_id];
757 	int err, old_reserved_pebs = vol->reserved_pebs;
758 
759 	if (ubi->ro_mode) {
760 		ubi_warn(ubi, "skip auto-resize because of R/O mode");
761 		return 0;
762 	}
763 
764 	/*
765 	 * Clear the auto-resize flag in the volume in-memory copy of the
766 	 * volume table, and 'ubi_resize_volume()' will propagate this change
767 	 * to the flash.
768 	 */
769 	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
770 
771 	if (ubi->avail_pebs == 0) {
772 		struct ubi_vtbl_record vtbl_rec;
773 
774 		/*
775 		 * No available PEBs to re-size the volume, clear the flag on
776 		 * flash and exit.
777 		 */
778 		vtbl_rec = ubi->vtbl[vol_id];
779 		err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
780 		if (err)
781 			ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
782 				vol_id);
783 	} else {
784 		desc.vol = vol;
785 		err = ubi_resize_volume(&desc,
786 					old_reserved_pebs + ubi->avail_pebs);
787 		if (err)
788 			ubi_err(ubi, "cannot auto-resize volume %d",
789 				vol_id);
790 	}
791 
792 	if (err)
793 		return err;
794 
795 	ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
796 		vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
797 	return 0;
798 }
799 
800 /**
801  * ubi_attach_mtd_dev - attach an MTD device.
802  * @mtd: MTD device description object
803  * @ubi_num: number to assign to the new UBI device
804  * @vid_hdr_offset: VID header offset
805  * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
806  *
807  * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
808  * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
809  * which case this function finds a vacant device number and assigns it
810  * automatically. Returns the new UBI device number in case of success and a
811  * negative error code in case of failure.
812  *
813  * Note, the invocations of this function has to be serialized by the
814  * @ubi_devices_mutex.
815  */
816 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
817 		       int vid_hdr_offset, int max_beb_per1024)
818 {
819 	struct ubi_device *ubi;
820 	int i, err;
821 
822 	if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
823 		return -EINVAL;
824 
825 	if (!max_beb_per1024)
826 		max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
827 
828 	/*
829 	 * Check if we already have the same MTD device attached.
830 	 *
831 	 * Note, this function assumes that UBI devices creations and deletions
832 	 * are serialized, so it does not take the &ubi_devices_lock.
833 	 */
834 	for (i = 0; i < UBI_MAX_DEVICES; i++) {
835 		ubi = ubi_devices[i];
836 		if (ubi && mtd->index == ubi->mtd->index) {
837 			pr_err("ubi: mtd%d is already attached to ubi%d\n",
838 				mtd->index, i);
839 			return -EEXIST;
840 		}
841 	}
842 
843 	/*
844 	 * Make sure this MTD device is not emulated on top of an UBI volume
845 	 * already. Well, generally this recursion works fine, but there are
846 	 * different problems like the UBI module takes a reference to itself
847 	 * by attaching (and thus, opening) the emulated MTD device. This
848 	 * results in inability to unload the module. And in general it makes
849 	 * no sense to attach emulated MTD devices, so we prohibit this.
850 	 */
851 	if (mtd->type == MTD_UBIVOLUME) {
852 		pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
853 			mtd->index);
854 		return -EINVAL;
855 	}
856 
857 	if (ubi_num == UBI_DEV_NUM_AUTO) {
858 		/* Search for an empty slot in the @ubi_devices array */
859 		for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
860 			if (!ubi_devices[ubi_num])
861 				break;
862 		if (ubi_num == UBI_MAX_DEVICES) {
863 			pr_err("ubi: only %d UBI devices may be created\n",
864 				UBI_MAX_DEVICES);
865 			return -ENFILE;
866 		}
867 	} else {
868 		if (ubi_num >= UBI_MAX_DEVICES)
869 			return -EINVAL;
870 
871 		/* Make sure ubi_num is not busy */
872 		if (ubi_devices[ubi_num]) {
873 			pr_err("ubi: ubi%i already exists\n", ubi_num);
874 			return -EEXIST;
875 		}
876 	}
877 
878 	ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
879 	if (!ubi)
880 		return -ENOMEM;
881 
882 	device_initialize(&ubi->dev);
883 	ubi->dev.release = dev_release;
884 	ubi->dev.class = &ubi_class;
885 	ubi->dev.groups = ubi_dev_groups;
886 
887 	ubi->mtd = mtd;
888 	ubi->ubi_num = ubi_num;
889 	ubi->vid_hdr_offset = vid_hdr_offset;
890 	ubi->autoresize_vol_id = -1;
891 
892 #ifdef CONFIG_MTD_UBI_FASTMAP
893 	ubi->fm_pool.used = ubi->fm_pool.size = 0;
894 	ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
895 
896 	/*
897 	 * fm_pool.max_size is 5% of the total number of PEBs but it's also
898 	 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
899 	 */
900 	ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
901 		ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
902 	ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
903 		UBI_FM_MIN_POOL_SIZE);
904 
905 	ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
906 	ubi->fm_disabled = !fm_autoconvert;
907 	if (fm_debug)
908 		ubi_enable_dbg_chk_fastmap(ubi);
909 
910 	if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
911 	    <= UBI_FM_MAX_START) {
912 		ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
913 			UBI_FM_MAX_START);
914 		ubi->fm_disabled = 1;
915 	}
916 
917 	ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
918 	ubi_msg(ubi, "default fastmap WL pool size: %d",
919 		ubi->fm_wl_pool.max_size);
920 #else
921 	ubi->fm_disabled = 1;
922 #endif
923 	mutex_init(&ubi->buf_mutex);
924 	mutex_init(&ubi->ckvol_mutex);
925 	mutex_init(&ubi->device_mutex);
926 	spin_lock_init(&ubi->volumes_lock);
927 	init_rwsem(&ubi->fm_protect);
928 	init_rwsem(&ubi->fm_eba_sem);
929 
930 	ubi_msg(ubi, "attaching mtd%d", mtd->index);
931 
932 	err = io_init(ubi, max_beb_per1024);
933 	if (err)
934 		goto out_free;
935 
936 	err = -ENOMEM;
937 	ubi->peb_buf = vmalloc(ubi->peb_size);
938 	if (!ubi->peb_buf)
939 		goto out_free;
940 
941 #ifdef CONFIG_MTD_UBI_FASTMAP
942 	ubi->fm_size = ubi_calc_fm_size(ubi);
943 	ubi->fm_buf = vzalloc(ubi->fm_size);
944 	if (!ubi->fm_buf)
945 		goto out_free;
946 #endif
947 	err = ubi_attach(ubi, 0);
948 	if (err) {
949 		ubi_err(ubi, "failed to attach mtd%d, error %d",
950 			mtd->index, err);
951 		goto out_free;
952 	}
953 
954 	if (ubi->autoresize_vol_id != -1) {
955 		err = autoresize(ubi, ubi->autoresize_vol_id);
956 		if (err)
957 			goto out_detach;
958 	}
959 
960 	/* Make device "available" before it becomes accessible via sysfs */
961 	ubi_devices[ubi_num] = ubi;
962 
963 	err = uif_init(ubi);
964 	if (err)
965 		goto out_detach;
966 
967 	err = ubi_debugfs_init_dev(ubi);
968 	if (err)
969 		goto out_uif;
970 
971 	ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
972 	if (IS_ERR(ubi->bgt_thread)) {
973 		err = PTR_ERR(ubi->bgt_thread);
974 		ubi_err(ubi, "cannot spawn \"%s\", error %d",
975 			ubi->bgt_name, err);
976 		goto out_debugfs;
977 	}
978 
979 	ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
980 		mtd->index, mtd->name, ubi->flash_size >> 20);
981 	ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
982 		ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
983 	ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
984 		ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
985 	ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
986 		ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
987 	ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
988 		ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
989 	ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
990 		ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
991 		ubi->vtbl_slots);
992 	ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
993 		ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
994 		ubi->image_seq);
995 	ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
996 		ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
997 
998 	/*
999 	 * The below lock makes sure we do not race with 'ubi_thread()' which
1000 	 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1001 	 */
1002 	spin_lock(&ubi->wl_lock);
1003 	ubi->thread_enabled = 1;
1004 	wake_up_process(ubi->bgt_thread);
1005 	spin_unlock(&ubi->wl_lock);
1006 
1007 	ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1008 	return ubi_num;
1009 
1010 out_debugfs:
1011 	ubi_debugfs_exit_dev(ubi);
1012 out_uif:
1013 	uif_close(ubi);
1014 out_detach:
1015 	ubi_devices[ubi_num] = NULL;
1016 	ubi_wl_close(ubi);
1017 	ubi_free_internal_volumes(ubi);
1018 	vfree(ubi->vtbl);
1019 out_free:
1020 	vfree(ubi->peb_buf);
1021 	vfree(ubi->fm_buf);
1022 	put_device(&ubi->dev);
1023 	return err;
1024 }
1025 
1026 /**
1027  * ubi_detach_mtd_dev - detach an MTD device.
1028  * @ubi_num: UBI device number to detach from
1029  * @anyway: detach MTD even if device reference count is not zero
1030  *
1031  * This function destroys an UBI device number @ubi_num and detaches the
1032  * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1033  * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1034  * exist.
1035  *
1036  * Note, the invocations of this function has to be serialized by the
1037  * @ubi_devices_mutex.
1038  */
1039 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1040 {
1041 	struct ubi_device *ubi;
1042 
1043 	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1044 		return -EINVAL;
1045 
1046 	ubi = ubi_get_device(ubi_num);
1047 	if (!ubi)
1048 		return -EINVAL;
1049 
1050 	spin_lock(&ubi_devices_lock);
1051 	put_device(&ubi->dev);
1052 	ubi->ref_count -= 1;
1053 	if (ubi->ref_count) {
1054 		if (!anyway) {
1055 			spin_unlock(&ubi_devices_lock);
1056 			return -EBUSY;
1057 		}
1058 		/* This may only happen if there is a bug */
1059 		ubi_err(ubi, "%s reference count %d, destroy anyway",
1060 			ubi->ubi_name, ubi->ref_count);
1061 	}
1062 	ubi_devices[ubi_num] = NULL;
1063 	spin_unlock(&ubi_devices_lock);
1064 
1065 	ubi_assert(ubi_num == ubi->ubi_num);
1066 	ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1067 	ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1068 #ifdef CONFIG_MTD_UBI_FASTMAP
1069 	/* If we don't write a new fastmap at detach time we lose all
1070 	 * EC updates that have been made since the last written fastmap.
1071 	 * In case of fastmap debugging we omit the update to simulate an
1072 	 * unclean shutdown. */
1073 	if (!ubi_dbg_chk_fastmap(ubi))
1074 		ubi_update_fastmap(ubi);
1075 #endif
1076 	/*
1077 	 * Before freeing anything, we have to stop the background thread to
1078 	 * prevent it from doing anything on this device while we are freeing.
1079 	 */
1080 	if (ubi->bgt_thread)
1081 		kthread_stop(ubi->bgt_thread);
1082 
1083 	ubi_debugfs_exit_dev(ubi);
1084 	uif_close(ubi);
1085 
1086 	ubi_wl_close(ubi);
1087 	ubi_free_internal_volumes(ubi);
1088 	vfree(ubi->vtbl);
1089 	put_mtd_device(ubi->mtd);
1090 	vfree(ubi->peb_buf);
1091 	vfree(ubi->fm_buf);
1092 	ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1093 	put_device(&ubi->dev);
1094 	return 0;
1095 }
1096 
1097 /**
1098  * open_mtd_by_chdev - open an MTD device by its character device node path.
1099  * @mtd_dev: MTD character device node path
1100  *
1101  * This helper function opens an MTD device by its character node device path.
1102  * Returns MTD device description object in case of success and a negative
1103  * error code in case of failure.
1104  */
1105 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1106 {
1107 	int err, minor;
1108 	struct path path;
1109 	struct kstat stat;
1110 
1111 	/* Probably this is an MTD character device node path */
1112 	err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1113 	if (err)
1114 		return ERR_PTR(err);
1115 
1116 	err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1117 	path_put(&path);
1118 	if (err)
1119 		return ERR_PTR(err);
1120 
1121 	/* MTD device number is defined by the major / minor numbers */
1122 	if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1123 		return ERR_PTR(-EINVAL);
1124 
1125 	minor = MINOR(stat.rdev);
1126 
1127 	if (minor & 1)
1128 		/*
1129 		 * Just do not think the "/dev/mtdrX" devices support is need,
1130 		 * so do not support them to avoid doing extra work.
1131 		 */
1132 		return ERR_PTR(-EINVAL);
1133 
1134 	return get_mtd_device(NULL, minor / 2);
1135 }
1136 
1137 /**
1138  * open_mtd_device - open MTD device by name, character device path, or number.
1139  * @mtd_dev: name, character device node path, or MTD device device number
1140  *
1141  * This function tries to open and MTD device described by @mtd_dev string,
1142  * which is first treated as ASCII MTD device number, and if it is not true, it
1143  * is treated as MTD device name, and if that is also not true, it is treated
1144  * as MTD character device node path. Returns MTD device description object in
1145  * case of success and a negative error code in case of failure.
1146  */
1147 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1148 {
1149 	struct mtd_info *mtd;
1150 	int mtd_num;
1151 	char *endp;
1152 
1153 	mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1154 	if (*endp != '\0' || mtd_dev == endp) {
1155 		/*
1156 		 * This does not look like an ASCII integer, probably this is
1157 		 * MTD device name.
1158 		 */
1159 		mtd = get_mtd_device_nm(mtd_dev);
1160 		if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV)
1161 			/* Probably this is an MTD character device node path */
1162 			mtd = open_mtd_by_chdev(mtd_dev);
1163 	} else
1164 		mtd = get_mtd_device(NULL, mtd_num);
1165 
1166 	return mtd;
1167 }
1168 
1169 static int __init ubi_init(void)
1170 {
1171 	int err, i, k;
1172 
1173 	/* Ensure that EC and VID headers have correct size */
1174 	BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1175 	BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1176 
1177 	if (mtd_devs > UBI_MAX_DEVICES) {
1178 		pr_err("UBI error: too many MTD devices, maximum is %d\n",
1179 		       UBI_MAX_DEVICES);
1180 		return -EINVAL;
1181 	}
1182 
1183 	/* Create base sysfs directory and sysfs files */
1184 	err = class_register(&ubi_class);
1185 	if (err < 0)
1186 		return err;
1187 
1188 	err = misc_register(&ubi_ctrl_cdev);
1189 	if (err) {
1190 		pr_err("UBI error: cannot register device\n");
1191 		goto out;
1192 	}
1193 
1194 	ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1195 					      sizeof(struct ubi_wl_entry),
1196 					      0, 0, NULL);
1197 	if (!ubi_wl_entry_slab) {
1198 		err = -ENOMEM;
1199 		goto out_dev_unreg;
1200 	}
1201 
1202 	err = ubi_debugfs_init();
1203 	if (err)
1204 		goto out_slab;
1205 
1206 
1207 	/* Attach MTD devices */
1208 	for (i = 0; i < mtd_devs; i++) {
1209 		struct mtd_dev_param *p = &mtd_dev_param[i];
1210 		struct mtd_info *mtd;
1211 
1212 		cond_resched();
1213 
1214 		mtd = open_mtd_device(p->name);
1215 		if (IS_ERR(mtd)) {
1216 			err = PTR_ERR(mtd);
1217 			pr_err("UBI error: cannot open mtd %s, error %d\n",
1218 			       p->name, err);
1219 			/* See comment below re-ubi_is_module(). */
1220 			if (ubi_is_module())
1221 				goto out_detach;
1222 			continue;
1223 		}
1224 
1225 		mutex_lock(&ubi_devices_mutex);
1226 		err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1227 					 p->vid_hdr_offs, p->max_beb_per1024);
1228 		mutex_unlock(&ubi_devices_mutex);
1229 		if (err < 0) {
1230 			pr_err("UBI error: cannot attach mtd%d\n",
1231 			       mtd->index);
1232 			put_mtd_device(mtd);
1233 
1234 			/*
1235 			 * Originally UBI stopped initializing on any error.
1236 			 * However, later on it was found out that this
1237 			 * behavior is not very good when UBI is compiled into
1238 			 * the kernel and the MTD devices to attach are passed
1239 			 * through the command line. Indeed, UBI failure
1240 			 * stopped whole boot sequence.
1241 			 *
1242 			 * To fix this, we changed the behavior for the
1243 			 * non-module case, but preserved the old behavior for
1244 			 * the module case, just for compatibility. This is a
1245 			 * little inconsistent, though.
1246 			 */
1247 			if (ubi_is_module())
1248 				goto out_detach;
1249 		}
1250 	}
1251 
1252 	err = ubiblock_init();
1253 	if (err) {
1254 		pr_err("UBI error: block: cannot initialize, error %d\n", err);
1255 
1256 		/* See comment above re-ubi_is_module(). */
1257 		if (ubi_is_module())
1258 			goto out_detach;
1259 	}
1260 
1261 	return 0;
1262 
1263 out_detach:
1264 	for (k = 0; k < i; k++)
1265 		if (ubi_devices[k]) {
1266 			mutex_lock(&ubi_devices_mutex);
1267 			ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1268 			mutex_unlock(&ubi_devices_mutex);
1269 		}
1270 	ubi_debugfs_exit();
1271 out_slab:
1272 	kmem_cache_destroy(ubi_wl_entry_slab);
1273 out_dev_unreg:
1274 	misc_deregister(&ubi_ctrl_cdev);
1275 out:
1276 	class_unregister(&ubi_class);
1277 	pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1278 	return err;
1279 }
1280 late_initcall(ubi_init);
1281 
1282 static void __exit ubi_exit(void)
1283 {
1284 	int i;
1285 
1286 	ubiblock_exit();
1287 
1288 	for (i = 0; i < UBI_MAX_DEVICES; i++)
1289 		if (ubi_devices[i]) {
1290 			mutex_lock(&ubi_devices_mutex);
1291 			ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1292 			mutex_unlock(&ubi_devices_mutex);
1293 		}
1294 	ubi_debugfs_exit();
1295 	kmem_cache_destroy(ubi_wl_entry_slab);
1296 	misc_deregister(&ubi_ctrl_cdev);
1297 	class_unregister(&ubi_class);
1298 }
1299 module_exit(ubi_exit);
1300 
1301 /**
1302  * bytes_str_to_int - convert a number of bytes string into an integer.
1303  * @str: the string to convert
1304  *
1305  * This function returns positive resulting integer in case of success and a
1306  * negative error code in case of failure.
1307  */
1308 static int bytes_str_to_int(const char *str)
1309 {
1310 	char *endp;
1311 	unsigned long result;
1312 
1313 	result = simple_strtoul(str, &endp, 0);
1314 	if (str == endp || result >= INT_MAX) {
1315 		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1316 		return -EINVAL;
1317 	}
1318 
1319 	switch (*endp) {
1320 	case 'G':
1321 		result *= 1024;
1322 	case 'M':
1323 		result *= 1024;
1324 	case 'K':
1325 		result *= 1024;
1326 		if (endp[1] == 'i' && endp[2] == 'B')
1327 			endp += 2;
1328 	case '\0':
1329 		break;
1330 	default:
1331 		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1332 		return -EINVAL;
1333 	}
1334 
1335 	return result;
1336 }
1337 
1338 /**
1339  * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1340  * @val: the parameter value to parse
1341  * @kp: not used
1342  *
1343  * This function returns zero in case of success and a negative error code in
1344  * case of error.
1345  */
1346 static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1347 {
1348 	int i, len;
1349 	struct mtd_dev_param *p;
1350 	char buf[MTD_PARAM_LEN_MAX];
1351 	char *pbuf = &buf[0];
1352 	char *tokens[MTD_PARAM_MAX_COUNT], *token;
1353 
1354 	if (!val)
1355 		return -EINVAL;
1356 
1357 	if (mtd_devs == UBI_MAX_DEVICES) {
1358 		pr_err("UBI error: too many parameters, max. is %d\n",
1359 		       UBI_MAX_DEVICES);
1360 		return -EINVAL;
1361 	}
1362 
1363 	len = strnlen(val, MTD_PARAM_LEN_MAX);
1364 	if (len == MTD_PARAM_LEN_MAX) {
1365 		pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1366 		       val, MTD_PARAM_LEN_MAX);
1367 		return -EINVAL;
1368 	}
1369 
1370 	if (len == 0) {
1371 		pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1372 		return 0;
1373 	}
1374 
1375 	strcpy(buf, val);
1376 
1377 	/* Get rid of the final newline */
1378 	if (buf[len - 1] == '\n')
1379 		buf[len - 1] = '\0';
1380 
1381 	for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1382 		tokens[i] = strsep(&pbuf, ",");
1383 
1384 	if (pbuf) {
1385 		pr_err("UBI error: too many arguments at \"%s\"\n", val);
1386 		return -EINVAL;
1387 	}
1388 
1389 	p = &mtd_dev_param[mtd_devs];
1390 	strcpy(&p->name[0], tokens[0]);
1391 
1392 	token = tokens[1];
1393 	if (token) {
1394 		p->vid_hdr_offs = bytes_str_to_int(token);
1395 
1396 		if (p->vid_hdr_offs < 0)
1397 			return p->vid_hdr_offs;
1398 	}
1399 
1400 	token = tokens[2];
1401 	if (token) {
1402 		int err = kstrtoint(token, 10, &p->max_beb_per1024);
1403 
1404 		if (err) {
1405 			pr_err("UBI error: bad value for max_beb_per1024 parameter: %s",
1406 			       token);
1407 			return -EINVAL;
1408 		}
1409 	}
1410 
1411 	token = tokens[3];
1412 	if (token) {
1413 		int err = kstrtoint(token, 10, &p->ubi_num);
1414 
1415 		if (err) {
1416 			pr_err("UBI error: bad value for ubi_num parameter: %s",
1417 			       token);
1418 			return -EINVAL;
1419 		}
1420 	} else
1421 		p->ubi_num = UBI_DEV_NUM_AUTO;
1422 
1423 	mtd_devs += 1;
1424 	return 0;
1425 }
1426 
1427 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1428 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1429 		      "Multiple \"mtd\" parameters may be specified.\n"
1430 		      "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1431 		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1432 		      "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1433 		      __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1434 		      "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1435 		      "\n"
1436 		      "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1437 		      "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"
1438 		      "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"
1439 		      "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"
1440 		      "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1441 #ifdef CONFIG_MTD_UBI_FASTMAP
1442 module_param(fm_autoconvert, bool, 0644);
1443 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1444 module_param(fm_debug, bool, 0);
1445 MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1446 #endif
1447 MODULE_VERSION(__stringify(UBI_VERSION));
1448 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1449 MODULE_AUTHOR("Artem Bityutskiy");
1450 MODULE_LICENSE("GPL");
1451