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 */
69struct 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 */
77static int __initdata mtd_devs;
78
79/* MTD devices specification parameters */
80static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
81#ifdef CONFIG_MTD_UBI_FASTMAP
82/* UBI module parameter to enable fastmap automatically on non-fastmap images */
83static bool fm_autoconvert;
84static bool fm_debug;
85#endif
86/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
87struct class *ubi_class;
88
89/* Slab cache for wear-leveling entries */
90struct kmem_cache *ubi_wl_entry_slab;
91
92/* UBI control character device */
93static struct miscdevice ubi_ctrl_cdev = {
94	.minor = MISC_DYNAMIC_MINOR,
95	.name = "ubi_ctrl",
96	.fops = &ubi_ctrl_cdev_operations,
97};
98
99/* All UBI devices in system */
100static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
101
102/* Serializes UBI devices creations and removals */
103DEFINE_MUTEX(ubi_devices_mutex);
104
105/* Protects @ubi_devices and @ubi->ref_count */
106static DEFINE_SPINLOCK(ubi_devices_lock);
107
108/* "Show" method for files in '/<sysfs>/class/ubi/' */
109static ssize_t ubi_version_show(struct class *class,
110				struct class_attribute *attr, char *buf)
111{
112	return sprintf(buf, "%d\n", UBI_VERSION);
113}
114
115/* UBI version attribute ('/<sysfs>/class/ubi/version') */
116static struct class_attribute ubi_version =
117	__ATTR(version, S_IRUGO, ubi_version_show, NULL);
118
119static ssize_t dev_attribute_show(struct device *dev,
120				  struct device_attribute *attr, char *buf);
121
122/* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
123static struct device_attribute dev_eraseblock_size =
124	__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
125static struct device_attribute dev_avail_eraseblocks =
126	__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
127static struct device_attribute dev_total_eraseblocks =
128	__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
129static struct device_attribute dev_volumes_count =
130	__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
131static struct device_attribute dev_max_ec =
132	__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
133static struct device_attribute dev_reserved_for_bad =
134	__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
135static struct device_attribute dev_bad_peb_count =
136	__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
137static struct device_attribute dev_max_vol_count =
138	__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
139static struct device_attribute dev_min_io_size =
140	__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
141static struct device_attribute dev_bgt_enabled =
142	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
143static struct device_attribute dev_mtd_num =
144	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
145
146/**
147 * ubi_volume_notify - send a volume change notification.
148 * @ubi: UBI device description object
149 * @vol: volume description object of the changed volume
150 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
151 *
152 * This is a helper function which notifies all subscribers about a volume
153 * change event (creation, removal, re-sizing, re-naming, updating). Returns
154 * zero in case of success and a negative error code in case of failure.
155 */
156int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
157{
158	int ret;
159	struct ubi_notification nt;
160
161	ubi_do_get_device_info(ubi, &nt.di);
162	ubi_do_get_volume_info(ubi, vol, &nt.vi);
163
164	switch (ntype) {
165	case UBI_VOLUME_ADDED:
166	case UBI_VOLUME_REMOVED:
167	case UBI_VOLUME_RESIZED:
168	case UBI_VOLUME_RENAMED:
169		ret = ubi_update_fastmap(ubi);
170		if (ret)
171			ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
172	}
173
174	return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
175}
176
177/**
178 * ubi_notify_all - send a notification to all volumes.
179 * @ubi: UBI device description object
180 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
181 * @nb: the notifier to call
182 *
183 * This function walks all volumes of UBI device @ubi and sends the @ntype
184 * notification for each volume. If @nb is %NULL, then all registered notifiers
185 * are called, otherwise only the @nb notifier is called. Returns the number of
186 * sent notifications.
187 */
188int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
189{
190	struct ubi_notification nt;
191	int i, count = 0;
192
193	ubi_do_get_device_info(ubi, &nt.di);
194
195	mutex_lock(&ubi->device_mutex);
196	for (i = 0; i < ubi->vtbl_slots; i++) {
197		/*
198		 * Since the @ubi->device is locked, and we are not going to
199		 * change @ubi->volumes, we do not have to lock
200		 * @ubi->volumes_lock.
201		 */
202		if (!ubi->volumes[i])
203			continue;
204
205		ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
206		if (nb)
207			nb->notifier_call(nb, ntype, &nt);
208		else
209			blocking_notifier_call_chain(&ubi_notifiers, ntype,
210						     &nt);
211		count += 1;
212	}
213	mutex_unlock(&ubi->device_mutex);
214
215	return count;
216}
217
218/**
219 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
220 * @nb: the notifier to call
221 *
222 * This function walks all UBI devices and volumes and sends the
223 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
224 * registered notifiers are called, otherwise only the @nb notifier is called.
225 * Returns the number of sent notifications.
226 */
227int ubi_enumerate_volumes(struct notifier_block *nb)
228{
229	int i, count = 0;
230
231	/*
232	 * Since the @ubi_devices_mutex is locked, and we are not going to
233	 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
234	 */
235	for (i = 0; i < UBI_MAX_DEVICES; i++) {
236		struct ubi_device *ubi = ubi_devices[i];
237
238		if (!ubi)
239			continue;
240		count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
241	}
242
243	return count;
244}
245
246/**
247 * ubi_get_device - get UBI device.
248 * @ubi_num: UBI device number
249 *
250 * This function returns UBI device description object for UBI device number
251 * @ubi_num, or %NULL if the device does not exist. This function increases the
252 * device reference count to prevent removal of the device. In other words, the
253 * device cannot be removed if its reference count is not zero.
254 */
255struct ubi_device *ubi_get_device(int ubi_num)
256{
257	struct ubi_device *ubi;
258
259	spin_lock(&ubi_devices_lock);
260	ubi = ubi_devices[ubi_num];
261	if (ubi) {
262		ubi_assert(ubi->ref_count >= 0);
263		ubi->ref_count += 1;
264		get_device(&ubi->dev);
265	}
266	spin_unlock(&ubi_devices_lock);
267
268	return ubi;
269}
270
271/**
272 * ubi_put_device - drop an UBI device reference.
273 * @ubi: UBI device description object
274 */
275void ubi_put_device(struct ubi_device *ubi)
276{
277	spin_lock(&ubi_devices_lock);
278	ubi->ref_count -= 1;
279	put_device(&ubi->dev);
280	spin_unlock(&ubi_devices_lock);
281}
282
283/**
284 * ubi_get_by_major - get UBI device by character device major number.
285 * @major: major number
286 *
287 * This function is similar to 'ubi_get_device()', but it searches the device
288 * by its major number.
289 */
290struct ubi_device *ubi_get_by_major(int major)
291{
292	int i;
293	struct ubi_device *ubi;
294
295	spin_lock(&ubi_devices_lock);
296	for (i = 0; i < UBI_MAX_DEVICES; i++) {
297		ubi = ubi_devices[i];
298		if (ubi && MAJOR(ubi->cdev.dev) == major) {
299			ubi_assert(ubi->ref_count >= 0);
300			ubi->ref_count += 1;
301			get_device(&ubi->dev);
302			spin_unlock(&ubi_devices_lock);
303			return ubi;
304		}
305	}
306	spin_unlock(&ubi_devices_lock);
307
308	return NULL;
309}
310
311/**
312 * ubi_major2num - get UBI device number by character device major number.
313 * @major: major number
314 *
315 * This function searches UBI device number object by its major number. If UBI
316 * device was not found, this function returns -ENODEV, otherwise the UBI device
317 * number is returned.
318 */
319int ubi_major2num(int major)
320{
321	int i, ubi_num = -ENODEV;
322
323	spin_lock(&ubi_devices_lock);
324	for (i = 0; i < UBI_MAX_DEVICES; i++) {
325		struct ubi_device *ubi = ubi_devices[i];
326
327		if (ubi && MAJOR(ubi->cdev.dev) == major) {
328			ubi_num = ubi->ubi_num;
329			break;
330		}
331	}
332	spin_unlock(&ubi_devices_lock);
333
334	return ubi_num;
335}
336
337/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
338static ssize_t dev_attribute_show(struct device *dev,
339				  struct device_attribute *attr, char *buf)
340{
341	ssize_t ret;
342	struct ubi_device *ubi;
343
344	/*
345	 * The below code looks weird, but it actually makes sense. We get the
346	 * UBI device reference from the contained 'struct ubi_device'. But it
347	 * is unclear if the device was removed or not yet. Indeed, if the
348	 * device was removed before we increased its reference count,
349	 * 'ubi_get_device()' will return -ENODEV and we fail.
350	 *
351	 * Remember, 'struct ubi_device' is freed in the release function, so
352	 * we still can use 'ubi->ubi_num'.
353	 */
354	ubi = container_of(dev, struct ubi_device, dev);
355	ubi = ubi_get_device(ubi->ubi_num);
356	if (!ubi)
357		return -ENODEV;
358
359	if (attr == &dev_eraseblock_size)
360		ret = sprintf(buf, "%d\n", ubi->leb_size);
361	else if (attr == &dev_avail_eraseblocks)
362		ret = sprintf(buf, "%d\n", ubi->avail_pebs);
363	else if (attr == &dev_total_eraseblocks)
364		ret = sprintf(buf, "%d\n", ubi->good_peb_count);
365	else if (attr == &dev_volumes_count)
366		ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
367	else if (attr == &dev_max_ec)
368		ret = sprintf(buf, "%d\n", ubi->max_ec);
369	else if (attr == &dev_reserved_for_bad)
370		ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
371	else if (attr == &dev_bad_peb_count)
372		ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
373	else if (attr == &dev_max_vol_count)
374		ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
375	else if (attr == &dev_min_io_size)
376		ret = sprintf(buf, "%d\n", ubi->min_io_size);
377	else if (attr == &dev_bgt_enabled)
378		ret = sprintf(buf, "%d\n", ubi->thread_enabled);
379	else if (attr == &dev_mtd_num)
380		ret = sprintf(buf, "%d\n", ubi->mtd->index);
381	else
382		ret = -EINVAL;
383
384	ubi_put_device(ubi);
385	return ret;
386}
387
388static void dev_release(struct device *dev)
389{
390	struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
391
392	kfree(ubi);
393}
394
395/**
396 * ubi_sysfs_init - initialize sysfs for an UBI device.
397 * @ubi: UBI device description object
398 * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
399 *       taken
400 *
401 * This function returns zero in case of success and a negative error code in
402 * case of failure.
403 */
404static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
405{
406	int err;
407
408	ubi->dev.release = dev_release;
409	ubi->dev.devt = ubi->cdev.dev;
410	ubi->dev.class = ubi_class;
411	dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
412	err = device_register(&ubi->dev);
413	if (err)
414		return err;
415
416	*ref = 1;
417	err = device_create_file(&ubi->dev, &dev_eraseblock_size);
418	if (err)
419		return err;
420	err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
421	if (err)
422		return err;
423	err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
424	if (err)
425		return err;
426	err = device_create_file(&ubi->dev, &dev_volumes_count);
427	if (err)
428		return err;
429	err = device_create_file(&ubi->dev, &dev_max_ec);
430	if (err)
431		return err;
432	err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
433	if (err)
434		return err;
435	err = device_create_file(&ubi->dev, &dev_bad_peb_count);
436	if (err)
437		return err;
438	err = device_create_file(&ubi->dev, &dev_max_vol_count);
439	if (err)
440		return err;
441	err = device_create_file(&ubi->dev, &dev_min_io_size);
442	if (err)
443		return err;
444	err = device_create_file(&ubi->dev, &dev_bgt_enabled);
445	if (err)
446		return err;
447	err = device_create_file(&ubi->dev, &dev_mtd_num);
448	return err;
449}
450
451/**
452 * ubi_sysfs_close - close sysfs for an UBI device.
453 * @ubi: UBI device description object
454 */
455static void ubi_sysfs_close(struct ubi_device *ubi)
456{
457	device_remove_file(&ubi->dev, &dev_mtd_num);
458	device_remove_file(&ubi->dev, &dev_bgt_enabled);
459	device_remove_file(&ubi->dev, &dev_min_io_size);
460	device_remove_file(&ubi->dev, &dev_max_vol_count);
461	device_remove_file(&ubi->dev, &dev_bad_peb_count);
462	device_remove_file(&ubi->dev, &dev_reserved_for_bad);
463	device_remove_file(&ubi->dev, &dev_max_ec);
464	device_remove_file(&ubi->dev, &dev_volumes_count);
465	device_remove_file(&ubi->dev, &dev_total_eraseblocks);
466	device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
467	device_remove_file(&ubi->dev, &dev_eraseblock_size);
468	device_unregister(&ubi->dev);
469}
470
471/**
472 * kill_volumes - destroy all user volumes.
473 * @ubi: UBI device description object
474 */
475static void kill_volumes(struct ubi_device *ubi)
476{
477	int i;
478
479	for (i = 0; i < ubi->vtbl_slots; i++)
480		if (ubi->volumes[i])
481			ubi_free_volume(ubi, ubi->volumes[i]);
482}
483
484/**
485 * uif_init - initialize user interfaces for an UBI device.
486 * @ubi: UBI device description object
487 * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
488 *       taken, otherwise set to %0
489 *
490 * This function initializes various user interfaces for an UBI device. If the
491 * initialization fails at an early stage, this function frees all the
492 * resources it allocated, returns an error, and @ref is set to %0. However,
493 * if the initialization fails after the UBI device was registered in the
494 * driver core subsystem, this function takes a reference to @ubi->dev, because
495 * otherwise the release function ('dev_release()') would free whole @ubi
496 * object. The @ref argument is set to %1 in this case. The caller has to put
497 * this reference.
498 *
499 * This function returns zero in case of success and a negative error code in
500 * case of failure.
501 */
502static int uif_init(struct ubi_device *ubi, int *ref)
503{
504	int i, err;
505	dev_t dev;
506
507	*ref = 0;
508	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
509
510	/*
511	 * Major numbers for the UBI character devices are allocated
512	 * dynamically. Major numbers of volume character devices are
513	 * equivalent to ones of the corresponding UBI character device. Minor
514	 * numbers of UBI character devices are 0, while minor numbers of
515	 * volume character devices start from 1. Thus, we allocate one major
516	 * number and ubi->vtbl_slots + 1 minor numbers.
517	 */
518	err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
519	if (err) {
520		ubi_err(ubi, "cannot register UBI character devices");
521		return err;
522	}
523
524	ubi_assert(MINOR(dev) == 0);
525	cdev_init(&ubi->cdev, &ubi_cdev_operations);
526	dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
527	ubi->cdev.owner = THIS_MODULE;
528
529	err = cdev_add(&ubi->cdev, dev, 1);
530	if (err) {
531		ubi_err(ubi, "cannot add character device");
532		goto out_unreg;
533	}
534
535	err = ubi_sysfs_init(ubi, ref);
536	if (err)
537		goto out_sysfs;
538
539	for (i = 0; i < ubi->vtbl_slots; i++)
540		if (ubi->volumes[i]) {
541			err = ubi_add_volume(ubi, ubi->volumes[i]);
542			if (err) {
543				ubi_err(ubi, "cannot add volume %d", i);
544				goto out_volumes;
545			}
546		}
547
548	return 0;
549
550out_volumes:
551	kill_volumes(ubi);
552out_sysfs:
553	if (*ref)
554		get_device(&ubi->dev);
555	ubi_sysfs_close(ubi);
556	cdev_del(&ubi->cdev);
557out_unreg:
558	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
559	ubi_err(ubi, "cannot initialize UBI %s, error %d",
560		ubi->ubi_name, err);
561	return err;
562}
563
564/**
565 * uif_close - close user interfaces for an UBI device.
566 * @ubi: UBI device description object
567 *
568 * Note, since this function un-registers UBI volume device objects (@vol->dev),
569 * the memory allocated voe the volumes is freed as well (in the release
570 * function).
571 */
572static void uif_close(struct ubi_device *ubi)
573{
574	kill_volumes(ubi);
575	ubi_sysfs_close(ubi);
576	cdev_del(&ubi->cdev);
577	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
578}
579
580/**
581 * ubi_free_internal_volumes - free internal volumes.
582 * @ubi: UBI device description object
583 */
584void ubi_free_internal_volumes(struct ubi_device *ubi)
585{
586	int i;
587
588	for (i = ubi->vtbl_slots;
589	     i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
590		kfree(ubi->volumes[i]->eba_tbl);
591		kfree(ubi->volumes[i]);
592	}
593}
594
595static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
596{
597	int limit, device_pebs;
598	uint64_t device_size;
599
600	if (!max_beb_per1024)
601		return 0;
602
603	/*
604	 * Here we are using size of the entire flash chip and
605	 * not just the MTD partition size because the maximum
606	 * number of bad eraseblocks is a percentage of the
607	 * whole device and bad eraseblocks are not fairly
608	 * distributed over the flash chip. So the worst case
609	 * is that all the bad eraseblocks of the chip are in
610	 * the MTD partition we are attaching (ubi->mtd).
611	 */
612	device_size = mtd_get_device_size(ubi->mtd);
613	device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
614	limit = mult_frac(device_pebs, max_beb_per1024, 1024);
615
616	/* Round it up */
617	if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
618		limit += 1;
619
620	return limit;
621}
622
623/**
624 * io_init - initialize I/O sub-system for a given UBI device.
625 * @ubi: UBI device description object
626 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
627 *
628 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
629 * assumed:
630 *   o EC header is always at offset zero - this cannot be changed;
631 *   o VID header starts just after the EC header at the closest address
632 *     aligned to @io->hdrs_min_io_size;
633 *   o data starts just after the VID header at the closest address aligned to
634 *     @io->min_io_size
635 *
636 * This function returns zero in case of success and a negative error code in
637 * case of failure.
638 */
639static int io_init(struct ubi_device *ubi, int max_beb_per1024)
640{
641	dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
642	dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
643
644	if (ubi->mtd->numeraseregions != 0) {
645		/*
646		 * Some flashes have several erase regions. Different regions
647		 * may have different eraseblock size and other
648		 * characteristics. It looks like mostly multi-region flashes
649		 * have one "main" region and one or more small regions to
650		 * store boot loader code or boot parameters or whatever. I
651		 * guess we should just pick the largest region. But this is
652		 * not implemented.
653		 */
654		ubi_err(ubi, "multiple regions, not implemented");
655		return -EINVAL;
656	}
657
658	if (ubi->vid_hdr_offset < 0)
659		return -EINVAL;
660
661	/*
662	 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
663	 * physical eraseblocks maximum.
664	 */
665
666	ubi->peb_size   = ubi->mtd->erasesize;
667	ubi->peb_count  = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
668	ubi->flash_size = ubi->mtd->size;
669
670	if (mtd_can_have_bb(ubi->mtd)) {
671		ubi->bad_allowed = 1;
672		ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
673	}
674
675	if (ubi->mtd->type == MTD_NORFLASH) {
676		ubi_assert(ubi->mtd->writesize == 1);
677		ubi->nor_flash = 1;
678	}
679
680	ubi->min_io_size = ubi->mtd->writesize;
681	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
682
683	/*
684	 * Make sure minimal I/O unit is power of 2. Note, there is no
685	 * fundamental reason for this assumption. It is just an optimization
686	 * which allows us to avoid costly division operations.
687	 */
688	if (!is_power_of_2(ubi->min_io_size)) {
689		ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
690			ubi->min_io_size);
691		return -EINVAL;
692	}
693
694	ubi_assert(ubi->hdrs_min_io_size > 0);
695	ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
696	ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
697
698	ubi->max_write_size = ubi->mtd->writebufsize;
699	/*
700	 * Maximum write size has to be greater or equivalent to min. I/O
701	 * size, and be multiple of min. I/O size.
702	 */
703	if (ubi->max_write_size < ubi->min_io_size ||
704	    ubi->max_write_size % ubi->min_io_size ||
705	    !is_power_of_2(ubi->max_write_size)) {
706		ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
707			ubi->max_write_size, ubi->min_io_size);
708		return -EINVAL;
709	}
710
711	/* Calculate default aligned sizes of EC and VID headers */
712	ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
713	ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
714
715	dbg_gen("min_io_size      %d", ubi->min_io_size);
716	dbg_gen("max_write_size   %d", ubi->max_write_size);
717	dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
718	dbg_gen("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
719	dbg_gen("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
720
721	if (ubi->vid_hdr_offset == 0)
722		/* Default offset */
723		ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
724				      ubi->ec_hdr_alsize;
725	else {
726		ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
727						~(ubi->hdrs_min_io_size - 1);
728		ubi->vid_hdr_shift = ubi->vid_hdr_offset -
729						ubi->vid_hdr_aloffset;
730	}
731
732	/* Similar for the data offset */
733	ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
734	ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
735
736	dbg_gen("vid_hdr_offset   %d", ubi->vid_hdr_offset);
737	dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
738	dbg_gen("vid_hdr_shift    %d", ubi->vid_hdr_shift);
739	dbg_gen("leb_start        %d", ubi->leb_start);
740
741	/* The shift must be aligned to 32-bit boundary */
742	if (ubi->vid_hdr_shift % 4) {
743		ubi_err(ubi, "unaligned VID header shift %d",
744			ubi->vid_hdr_shift);
745		return -EINVAL;
746	}
747
748	/* Check sanity */
749	if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
750	    ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
751	    ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
752	    ubi->leb_start & (ubi->min_io_size - 1)) {
753		ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
754			ubi->vid_hdr_offset, ubi->leb_start);
755		return -EINVAL;
756	}
757
758	/*
759	 * Set maximum amount of physical erroneous eraseblocks to be 10%.
760	 * Erroneous PEB are those which have read errors.
761	 */
762	ubi->max_erroneous = ubi->peb_count / 10;
763	if (ubi->max_erroneous < 16)
764		ubi->max_erroneous = 16;
765	dbg_gen("max_erroneous    %d", ubi->max_erroneous);
766
767	/*
768	 * It may happen that EC and VID headers are situated in one minimal
769	 * I/O unit. In this case we can only accept this UBI image in
770	 * read-only mode.
771	 */
772	if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
773		ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
774		ubi->ro_mode = 1;
775	}
776
777	ubi->leb_size = ubi->peb_size - ubi->leb_start;
778
779	if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
780		ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
781			ubi->mtd->index);
782		ubi->ro_mode = 1;
783	}
784
785	/*
786	 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
787	 * unfortunately, MTD does not provide this information. We should loop
788	 * over all physical eraseblocks and invoke mtd->block_is_bad() for
789	 * each physical eraseblock. So, we leave @ubi->bad_peb_count
790	 * uninitialized so far.
791	 */
792
793	return 0;
794}
795
796/**
797 * autoresize - re-size the volume which has the "auto-resize" flag set.
798 * @ubi: UBI device description object
799 * @vol_id: ID of the volume to re-size
800 *
801 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
802 * the volume table to the largest possible size. See comments in ubi-header.h
803 * for more description of the flag. Returns zero in case of success and a
804 * negative error code in case of failure.
805 */
806static int autoresize(struct ubi_device *ubi, int vol_id)
807{
808	struct ubi_volume_desc desc;
809	struct ubi_volume *vol = ubi->volumes[vol_id];
810	int err, old_reserved_pebs = vol->reserved_pebs;
811
812	if (ubi->ro_mode) {
813		ubi_warn(ubi, "skip auto-resize because of R/O mode");
814		return 0;
815	}
816
817	/*
818	 * Clear the auto-resize flag in the volume in-memory copy of the
819	 * volume table, and 'ubi_resize_volume()' will propagate this change
820	 * to the flash.
821	 */
822	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
823
824	if (ubi->avail_pebs == 0) {
825		struct ubi_vtbl_record vtbl_rec;
826
827		/*
828		 * No available PEBs to re-size the volume, clear the flag on
829		 * flash and exit.
830		 */
831		vtbl_rec = ubi->vtbl[vol_id];
832		err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
833		if (err)
834			ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
835				vol_id);
836	} else {
837		desc.vol = vol;
838		err = ubi_resize_volume(&desc,
839					old_reserved_pebs + ubi->avail_pebs);
840		if (err)
841			ubi_err(ubi, "cannot auto-resize volume %d",
842				vol_id);
843	}
844
845	if (err)
846		return err;
847
848	ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
849		vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
850	return 0;
851}
852
853/**
854 * ubi_attach_mtd_dev - attach an MTD device.
855 * @mtd: MTD device description object
856 * @ubi_num: number to assign to the new UBI device
857 * @vid_hdr_offset: VID header offset
858 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
859 *
860 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
861 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
862 * which case this function finds a vacant device number and assigns it
863 * automatically. Returns the new UBI device number in case of success and a
864 * negative error code in case of failure.
865 *
866 * Note, the invocations of this function has to be serialized by the
867 * @ubi_devices_mutex.
868 */
869int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
870		       int vid_hdr_offset, int max_beb_per1024)
871{
872	struct ubi_device *ubi;
873	int i, err, ref = 0;
874
875	if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
876		return -EINVAL;
877
878	if (!max_beb_per1024)
879		max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
880
881	/*
882	 * Check if we already have the same MTD device attached.
883	 *
884	 * Note, this function assumes that UBI devices creations and deletions
885	 * are serialized, so it does not take the &ubi_devices_lock.
886	 */
887	for (i = 0; i < UBI_MAX_DEVICES; i++) {
888		ubi = ubi_devices[i];
889		if (ubi && mtd->index == ubi->mtd->index) {
890			ubi_err(ubi, "mtd%d is already attached to ubi%d",
891				mtd->index, i);
892			return -EEXIST;
893		}
894	}
895
896	/*
897	 * Make sure this MTD device is not emulated on top of an UBI volume
898	 * already. Well, generally this recursion works fine, but there are
899	 * different problems like the UBI module takes a reference to itself
900	 * by attaching (and thus, opening) the emulated MTD device. This
901	 * results in inability to unload the module. And in general it makes
902	 * no sense to attach emulated MTD devices, so we prohibit this.
903	 */
904	if (mtd->type == MTD_UBIVOLUME) {
905		ubi_err(ubi, "refuse attaching mtd%d - it is already emulated on top of UBI",
906			mtd->index);
907		return -EINVAL;
908	}
909
910	if (ubi_num == UBI_DEV_NUM_AUTO) {
911		/* Search for an empty slot in the @ubi_devices array */
912		for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
913			if (!ubi_devices[ubi_num])
914				break;
915		if (ubi_num == UBI_MAX_DEVICES) {
916			ubi_err(ubi, "only %d UBI devices may be created",
917				UBI_MAX_DEVICES);
918			return -ENFILE;
919		}
920	} else {
921		if (ubi_num >= UBI_MAX_DEVICES)
922			return -EINVAL;
923
924		/* Make sure ubi_num is not busy */
925		if (ubi_devices[ubi_num]) {
926			ubi_err(ubi, "already exists");
927			return -EEXIST;
928		}
929	}
930
931	ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
932	if (!ubi)
933		return -ENOMEM;
934
935	ubi->mtd = mtd;
936	ubi->ubi_num = ubi_num;
937	ubi->vid_hdr_offset = vid_hdr_offset;
938	ubi->autoresize_vol_id = -1;
939
940#ifdef CONFIG_MTD_UBI_FASTMAP
941	ubi->fm_pool.used = ubi->fm_pool.size = 0;
942	ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
943
944	/*
945	 * fm_pool.max_size is 5% of the total number of PEBs but it's also
946	 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
947	 */
948	ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
949		ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
950	if (ubi->fm_pool.max_size < UBI_FM_MIN_POOL_SIZE)
951		ubi->fm_pool.max_size = UBI_FM_MIN_POOL_SIZE;
952
953	ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
954	ubi->fm_disabled = !fm_autoconvert;
955	if (fm_debug)
956		ubi_enable_dbg_chk_fastmap(ubi);
957
958	if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
959	    <= UBI_FM_MAX_START) {
960		ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
961			UBI_FM_MAX_START);
962		ubi->fm_disabled = 1;
963	}
964
965	ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
966	ubi_msg(ubi, "default fastmap WL pool size: %d",
967		ubi->fm_wl_pool.max_size);
968#else
969	ubi->fm_disabled = 1;
970#endif
971	mutex_init(&ubi->buf_mutex);
972	mutex_init(&ubi->ckvol_mutex);
973	mutex_init(&ubi->device_mutex);
974	spin_lock_init(&ubi->volumes_lock);
975	init_rwsem(&ubi->fm_protect);
976	init_rwsem(&ubi->fm_eba_sem);
977
978	ubi_msg(ubi, "attaching mtd%d", mtd->index);
979
980	err = io_init(ubi, max_beb_per1024);
981	if (err)
982		goto out_free;
983
984	err = -ENOMEM;
985	ubi->peb_buf = vmalloc(ubi->peb_size);
986	if (!ubi->peb_buf)
987		goto out_free;
988
989#ifdef CONFIG_MTD_UBI_FASTMAP
990	ubi->fm_size = ubi_calc_fm_size(ubi);
991	ubi->fm_buf = vzalloc(ubi->fm_size);
992	if (!ubi->fm_buf)
993		goto out_free;
994#endif
995	err = ubi_attach(ubi, 0);
996	if (err) {
997		ubi_err(ubi, "failed to attach mtd%d, error %d",
998			mtd->index, err);
999		goto out_free;
1000	}
1001
1002	if (ubi->autoresize_vol_id != -1) {
1003		err = autoresize(ubi, ubi->autoresize_vol_id);
1004		if (err)
1005			goto out_detach;
1006	}
1007
1008	err = uif_init(ubi, &ref);
1009	if (err)
1010		goto out_detach;
1011
1012	err = ubi_debugfs_init_dev(ubi);
1013	if (err)
1014		goto out_uif;
1015
1016	ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
1017	if (IS_ERR(ubi->bgt_thread)) {
1018		err = PTR_ERR(ubi->bgt_thread);
1019		ubi_err(ubi, "cannot spawn \"%s\", error %d",
1020			ubi->bgt_name, err);
1021		goto out_debugfs;
1022	}
1023
1024	ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
1025		mtd->index, mtd->name, ubi->flash_size >> 20);
1026	ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
1027		ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
1028	ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
1029		ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1030	ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1031		ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1032	ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1033		ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1034	ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1035		ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1036		ubi->vtbl_slots);
1037	ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1038		ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1039		ubi->image_seq);
1040	ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1041		ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1042
1043	/*
1044	 * The below lock makes sure we do not race with 'ubi_thread()' which
1045	 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1046	 */
1047	spin_lock(&ubi->wl_lock);
1048	ubi->thread_enabled = 1;
1049	wake_up_process(ubi->bgt_thread);
1050	spin_unlock(&ubi->wl_lock);
1051
1052	ubi_devices[ubi_num] = ubi;
1053	ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1054	return ubi_num;
1055
1056out_debugfs:
1057	ubi_debugfs_exit_dev(ubi);
1058out_uif:
1059	get_device(&ubi->dev);
1060	ubi_assert(ref);
1061	uif_close(ubi);
1062out_detach:
1063	ubi_wl_close(ubi);
1064	ubi_free_internal_volumes(ubi);
1065	vfree(ubi->vtbl);
1066out_free:
1067	vfree(ubi->peb_buf);
1068	vfree(ubi->fm_buf);
1069	if (ref)
1070		put_device(&ubi->dev);
1071	else
1072		kfree(ubi);
1073	return err;
1074}
1075
1076/**
1077 * ubi_detach_mtd_dev - detach an MTD device.
1078 * @ubi_num: UBI device number to detach from
1079 * @anyway: detach MTD even if device reference count is not zero
1080 *
1081 * This function destroys an UBI device number @ubi_num and detaches the
1082 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1083 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1084 * exist.
1085 *
1086 * Note, the invocations of this function has to be serialized by the
1087 * @ubi_devices_mutex.
1088 */
1089int ubi_detach_mtd_dev(int ubi_num, int anyway)
1090{
1091	struct ubi_device *ubi;
1092
1093	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1094		return -EINVAL;
1095
1096	ubi = ubi_get_device(ubi_num);
1097	if (!ubi)
1098		return -EINVAL;
1099
1100	spin_lock(&ubi_devices_lock);
1101	put_device(&ubi->dev);
1102	ubi->ref_count -= 1;
1103	if (ubi->ref_count) {
1104		if (!anyway) {
1105			spin_unlock(&ubi_devices_lock);
1106			return -EBUSY;
1107		}
1108		/* This may only happen if there is a bug */
1109		ubi_err(ubi, "%s reference count %d, destroy anyway",
1110			ubi->ubi_name, ubi->ref_count);
1111	}
1112	ubi_devices[ubi_num] = NULL;
1113	spin_unlock(&ubi_devices_lock);
1114
1115	ubi_assert(ubi_num == ubi->ubi_num);
1116	ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1117	ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1118#ifdef CONFIG_MTD_UBI_FASTMAP
1119	/* If we don't write a new fastmap at detach time we lose all
1120	 * EC updates that have been made since the last written fastmap.
1121	 * In case of fastmap debugging we omit the update to simulate an
1122	 * unclean shutdown. */
1123	if (!ubi_dbg_chk_fastmap(ubi))
1124		ubi_update_fastmap(ubi);
1125#endif
1126	/*
1127	 * Before freeing anything, we have to stop the background thread to
1128	 * prevent it from doing anything on this device while we are freeing.
1129	 */
1130	if (ubi->bgt_thread)
1131		kthread_stop(ubi->bgt_thread);
1132
1133	/*
1134	 * Get a reference to the device in order to prevent 'dev_release()'
1135	 * from freeing the @ubi object.
1136	 */
1137	get_device(&ubi->dev);
1138
1139	ubi_debugfs_exit_dev(ubi);
1140	uif_close(ubi);
1141
1142	ubi_wl_close(ubi);
1143	ubi_free_internal_volumes(ubi);
1144	vfree(ubi->vtbl);
1145	put_mtd_device(ubi->mtd);
1146	vfree(ubi->peb_buf);
1147	vfree(ubi->fm_buf);
1148	ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1149	put_device(&ubi->dev);
1150	return 0;
1151}
1152
1153/**
1154 * open_mtd_by_chdev - open an MTD device by its character device node path.
1155 * @mtd_dev: MTD character device node path
1156 *
1157 * This helper function opens an MTD device by its character node device path.
1158 * Returns MTD device description object in case of success and a negative
1159 * error code in case of failure.
1160 */
1161static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1162{
1163	int err, major, minor, mode;
1164	struct path path;
1165
1166	/* Probably this is an MTD character device node path */
1167	err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1168	if (err)
1169		return ERR_PTR(err);
1170
1171	/* MTD device number is defined by the major / minor numbers */
1172	major = imajor(d_backing_inode(path.dentry));
1173	minor = iminor(d_backing_inode(path.dentry));
1174	mode = d_backing_inode(path.dentry)->i_mode;
1175	path_put(&path);
1176	if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))
1177		return ERR_PTR(-EINVAL);
1178
1179	if (minor & 1)
1180		/*
1181		 * Just do not think the "/dev/mtdrX" devices support is need,
1182		 * so do not support them to avoid doing extra work.
1183		 */
1184		return ERR_PTR(-EINVAL);
1185
1186	return get_mtd_device(NULL, minor / 2);
1187}
1188
1189/**
1190 * open_mtd_device - open MTD device by name, character device path, or number.
1191 * @mtd_dev: name, character device node path, or MTD device device number
1192 *
1193 * This function tries to open and MTD device described by @mtd_dev string,
1194 * which is first treated as ASCII MTD device number, and if it is not true, it
1195 * is treated as MTD device name, and if that is also not true, it is treated
1196 * as MTD character device node path. Returns MTD device description object in
1197 * case of success and a negative error code in case of failure.
1198 */
1199static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1200{
1201	struct mtd_info *mtd;
1202	int mtd_num;
1203	char *endp;
1204
1205	mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1206	if (*endp != '\0' || mtd_dev == endp) {
1207		/*
1208		 * This does not look like an ASCII integer, probably this is
1209		 * MTD device name.
1210		 */
1211		mtd = get_mtd_device_nm(mtd_dev);
1212		if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV)
1213			/* Probably this is an MTD character device node path */
1214			mtd = open_mtd_by_chdev(mtd_dev);
1215	} else
1216		mtd = get_mtd_device(NULL, mtd_num);
1217
1218	return mtd;
1219}
1220
1221static int __init ubi_init(void)
1222{
1223	int err, i, k;
1224
1225	/* Ensure that EC and VID headers have correct size */
1226	BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1227	BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1228
1229	if (mtd_devs > UBI_MAX_DEVICES) {
1230		pr_err("UBI error: too many MTD devices, maximum is %d",
1231		       UBI_MAX_DEVICES);
1232		return -EINVAL;
1233	}
1234
1235	/* Create base sysfs directory and sysfs files */
1236	ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
1237	if (IS_ERR(ubi_class)) {
1238		err = PTR_ERR(ubi_class);
1239		pr_err("UBI error: cannot create UBI class");
1240		goto out;
1241	}
1242
1243	err = class_create_file(ubi_class, &ubi_version);
1244	if (err) {
1245		pr_err("UBI error: cannot create sysfs file");
1246		goto out_class;
1247	}
1248
1249	err = misc_register(&ubi_ctrl_cdev);
1250	if (err) {
1251		pr_err("UBI error: cannot register device");
1252		goto out_version;
1253	}
1254
1255	ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1256					      sizeof(struct ubi_wl_entry),
1257					      0, 0, NULL);
1258	if (!ubi_wl_entry_slab) {
1259		err = -ENOMEM;
1260		goto out_dev_unreg;
1261	}
1262
1263	err = ubi_debugfs_init();
1264	if (err)
1265		goto out_slab;
1266
1267
1268	/* Attach MTD devices */
1269	for (i = 0; i < mtd_devs; i++) {
1270		struct mtd_dev_param *p = &mtd_dev_param[i];
1271		struct mtd_info *mtd;
1272
1273		cond_resched();
1274
1275		mtd = open_mtd_device(p->name);
1276		if (IS_ERR(mtd)) {
1277			err = PTR_ERR(mtd);
1278			pr_err("UBI error: cannot open mtd %s, error %d",
1279			       p->name, err);
1280			/* See comment below re-ubi_is_module(). */
1281			if (ubi_is_module())
1282				goto out_detach;
1283			continue;
1284		}
1285
1286		mutex_lock(&ubi_devices_mutex);
1287		err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1288					 p->vid_hdr_offs, p->max_beb_per1024);
1289		mutex_unlock(&ubi_devices_mutex);
1290		if (err < 0) {
1291			pr_err("UBI error: cannot attach mtd%d",
1292			       mtd->index);
1293			put_mtd_device(mtd);
1294
1295			/*
1296			 * Originally UBI stopped initializing on any error.
1297			 * However, later on it was found out that this
1298			 * behavior is not very good when UBI is compiled into
1299			 * the kernel and the MTD devices to attach are passed
1300			 * through the command line. Indeed, UBI failure
1301			 * stopped whole boot sequence.
1302			 *
1303			 * To fix this, we changed the behavior for the
1304			 * non-module case, but preserved the old behavior for
1305			 * the module case, just for compatibility. This is a
1306			 * little inconsistent, though.
1307			 */
1308			if (ubi_is_module())
1309				goto out_detach;
1310		}
1311	}
1312
1313	err = ubiblock_init();
1314	if (err) {
1315		pr_err("UBI error: block: cannot initialize, error %d", err);
1316
1317		/* See comment above re-ubi_is_module(). */
1318		if (ubi_is_module())
1319			goto out_detach;
1320	}
1321
1322	return 0;
1323
1324out_detach:
1325	for (k = 0; k < i; k++)
1326		if (ubi_devices[k]) {
1327			mutex_lock(&ubi_devices_mutex);
1328			ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1329			mutex_unlock(&ubi_devices_mutex);
1330		}
1331	ubi_debugfs_exit();
1332out_slab:
1333	kmem_cache_destroy(ubi_wl_entry_slab);
1334out_dev_unreg:
1335	misc_deregister(&ubi_ctrl_cdev);
1336out_version:
1337	class_remove_file(ubi_class, &ubi_version);
1338out_class:
1339	class_destroy(ubi_class);
1340out:
1341	pr_err("UBI error: cannot initialize UBI, error %d", err);
1342	return err;
1343}
1344late_initcall(ubi_init);
1345
1346static void __exit ubi_exit(void)
1347{
1348	int i;
1349
1350	ubiblock_exit();
1351
1352	for (i = 0; i < UBI_MAX_DEVICES; i++)
1353		if (ubi_devices[i]) {
1354			mutex_lock(&ubi_devices_mutex);
1355			ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1356			mutex_unlock(&ubi_devices_mutex);
1357		}
1358	ubi_debugfs_exit();
1359	kmem_cache_destroy(ubi_wl_entry_slab);
1360	misc_deregister(&ubi_ctrl_cdev);
1361	class_remove_file(ubi_class, &ubi_version);
1362	class_destroy(ubi_class);
1363}
1364module_exit(ubi_exit);
1365
1366/**
1367 * bytes_str_to_int - convert a number of bytes string into an integer.
1368 * @str: the string to convert
1369 *
1370 * This function returns positive resulting integer in case of success and a
1371 * negative error code in case of failure.
1372 */
1373static int __init bytes_str_to_int(const char *str)
1374{
1375	char *endp;
1376	unsigned long result;
1377
1378	result = simple_strtoul(str, &endp, 0);
1379	if (str == endp || result >= INT_MAX) {
1380		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1381		return -EINVAL;
1382	}
1383
1384	switch (*endp) {
1385	case 'G':
1386		result *= 1024;
1387	case 'M':
1388		result *= 1024;
1389	case 'K':
1390		result *= 1024;
1391		if (endp[1] == 'i' && endp[2] == 'B')
1392			endp += 2;
1393	case '\0':
1394		break;
1395	default:
1396		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1397		return -EINVAL;
1398	}
1399
1400	return result;
1401}
1402
1403/**
1404 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1405 * @val: the parameter value to parse
1406 * @kp: not used
1407 *
1408 * This function returns zero in case of success and a negative error code in
1409 * case of error.
1410 */
1411static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1412{
1413	int i, len;
1414	struct mtd_dev_param *p;
1415	char buf[MTD_PARAM_LEN_MAX];
1416	char *pbuf = &buf[0];
1417	char *tokens[MTD_PARAM_MAX_COUNT], *token;
1418
1419	if (!val)
1420		return -EINVAL;
1421
1422	if (mtd_devs == UBI_MAX_DEVICES) {
1423		pr_err("UBI error: too many parameters, max. is %d\n",
1424		       UBI_MAX_DEVICES);
1425		return -EINVAL;
1426	}
1427
1428	len = strnlen(val, MTD_PARAM_LEN_MAX);
1429	if (len == MTD_PARAM_LEN_MAX) {
1430		pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1431		       val, MTD_PARAM_LEN_MAX);
1432		return -EINVAL;
1433	}
1434
1435	if (len == 0) {
1436		pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1437		return 0;
1438	}
1439
1440	strcpy(buf, val);
1441
1442	/* Get rid of the final newline */
1443	if (buf[len - 1] == '\n')
1444		buf[len - 1] = '\0';
1445
1446	for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1447		tokens[i] = strsep(&pbuf, ",");
1448
1449	if (pbuf) {
1450		pr_err("UBI error: too many arguments at \"%s\"\n", val);
1451		return -EINVAL;
1452	}
1453
1454	p = &mtd_dev_param[mtd_devs];
1455	strcpy(&p->name[0], tokens[0]);
1456
1457	token = tokens[1];
1458	if (token) {
1459		p->vid_hdr_offs = bytes_str_to_int(token);
1460
1461		if (p->vid_hdr_offs < 0)
1462			return p->vid_hdr_offs;
1463	}
1464
1465	token = tokens[2];
1466	if (token) {
1467		int err = kstrtoint(token, 10, &p->max_beb_per1024);
1468
1469		if (err) {
1470			pr_err("UBI error: bad value for max_beb_per1024 parameter: %s",
1471			       token);
1472			return -EINVAL;
1473		}
1474	}
1475
1476	token = tokens[3];
1477	if (token) {
1478		int err = kstrtoint(token, 10, &p->ubi_num);
1479
1480		if (err) {
1481			pr_err("UBI error: bad value for ubi_num parameter: %s",
1482			       token);
1483			return -EINVAL;
1484		}
1485	} else
1486		p->ubi_num = UBI_DEV_NUM_AUTO;
1487
1488	mtd_devs += 1;
1489	return 0;
1490}
1491
1492module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1493MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1494		      "Multiple \"mtd\" parameters may be specified.\n"
1495		      "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1496		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1497		      "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1498		      __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1499		      "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1500		      "\n"
1501		      "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1502		      "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"
1503		      "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"
1504		      "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"
1505		      "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1506#ifdef CONFIG_MTD_UBI_FASTMAP
1507module_param(fm_autoconvert, bool, 0644);
1508MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1509module_param(fm_debug, bool, 0);
1510MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1511#endif
1512MODULE_VERSION(__stringify(UBI_VERSION));
1513MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1514MODULE_AUTHOR("Artem Bityutskiy");
1515MODULE_LICENSE("GPL");
1516