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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) International Business Machines Corp., 2006
4  * Copyright (c) Nokia Corporation, 2007
5  *
6  * Author: Artem Bityutskiy (Битюцкий Артём),
7  *         Frank Haverkamp
8  */
9 
10 /*
11  * This file includes UBI initialization and building of UBI devices.
12  *
13  * When UBI is initialized, it attaches all the MTD devices specified as the
14  * module load parameters or the kernel boot parameters. If MTD devices were
15  * specified, UBI does not attach any MTD device, but it is possible to do
16  * later using the "UBI control device".
17  */
18 
19 #ifndef __UBOOT__
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <linux/stringify.h>
23 #include <linux/namei.h>
24 #include <linux/stat.h>
25 #include <linux/miscdevice.h>
26 #include <linux/log2.h>
27 #include <linux/kthread.h>
28 #include <linux/kernel.h>
29 #include <linux/slab.h>
30 #include <linux/major.h>
31 #else
32 #include <linux/bug.h>
33 #include <linux/log2.h>
34 #endif
35 #include <linux/err.h>
36 #include <ubi_uboot.h>
37 #include <linux/mtd/partitions.h>
38 
39 #include "ubi.h"
40 
41 /* Maximum length of the 'mtd=' parameter */
42 #define MTD_PARAM_LEN_MAX 64
43 
44 /* Maximum number of comma-separated items in the 'mtd=' parameter */
45 #define MTD_PARAM_MAX_COUNT 4
46 
47 /* Maximum value for the number of bad PEBs per 1024 PEBs */
48 #define MAX_MTD_UBI_BEB_LIMIT 768
49 
50 #ifdef CONFIG_MTD_UBI_MODULE
51 #define ubi_is_module() 1
52 #else
53 #define ubi_is_module() 0
54 #endif
55 
56 #if (CONFIG_SYS_MALLOC_LEN < (512 << 10))
57 #error Malloc area too small for UBI, increase CONFIG_SYS_MALLOC_LEN to >= 512k
58 #endif
59 
60 /**
61  * struct mtd_dev_param - MTD device parameter description data structure.
62  * @name: MTD character device node path, MTD device name, or MTD device number
63  *        string
64  * @vid_hdr_offs: VID header offset
65  * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
66  */
67 struct mtd_dev_param {
68 	char name[MTD_PARAM_LEN_MAX];
69 	int ubi_num;
70 	int vid_hdr_offs;
71 	int max_beb_per1024;
72 };
73 
74 /* Numbers of elements set in the @mtd_dev_param array */
75 static int __initdata mtd_devs;
76 
77 /* MTD devices specification parameters */
78 static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
79 #ifndef __UBOOT__
80 #ifdef CONFIG_MTD_UBI_FASTMAP
81 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
82 static bool fm_autoconvert;
83 static bool fm_debug;
84 #endif
85 #else
86 #ifdef CONFIG_MTD_UBI_FASTMAP
87 #if !defined(CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT)
88 #define CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT 0
89 #endif
90 static bool fm_autoconvert = CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT;
91 #if !defined(CONFIG_MTD_UBI_FM_DEBUG)
92 #define CONFIG_MTD_UBI_FM_DEBUG 0
93 #endif
94 static bool fm_debug = CONFIG_MTD_UBI_FM_DEBUG;
95 #endif
96 #endif
97 
98 /* Slab cache for wear-leveling entries */
99 struct kmem_cache *ubi_wl_entry_slab;
100 
101 #ifndef __UBOOT__
102 /* UBI control character device */
103 static struct miscdevice ubi_ctrl_cdev = {
104 	.minor = MISC_DYNAMIC_MINOR,
105 	.name = "ubi_ctrl",
106 	.fops = &ubi_ctrl_cdev_operations,
107 };
108 #endif
109 
110 /* All UBI devices in system */
111 #ifndef __UBOOT__
112 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
113 #else
114 struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
115 #endif
116 
117 #ifndef __UBOOT__
118 /* Serializes UBI devices creations and removals */
119 DEFINE_MUTEX(ubi_devices_mutex);
120 
121 /* Protects @ubi_devices and @ubi->ref_count */
122 static DEFINE_SPINLOCK(ubi_devices_lock);
123 
124 /* "Show" method for files in '/<sysfs>/class/ubi/' */
ubi_version_show(struct class * class,struct class_attribute * attr,char * buf)125 static ssize_t ubi_version_show(struct class *class,
126 				struct class_attribute *attr, char *buf)
127 {
128 	return sprintf(buf, "%d\n", UBI_VERSION);
129 }
130 
131 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
132 static struct class_attribute ubi_class_attrs[] = {
133 	__ATTR(version, S_IRUGO, ubi_version_show, NULL),
134 	__ATTR_NULL
135 };
136 
137 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
138 struct class ubi_class = {
139 	.name		= UBI_NAME_STR,
140 	.owner		= THIS_MODULE,
141 	.class_attrs	= ubi_class_attrs,
142 };
143 
144 static ssize_t dev_attribute_show(struct device *dev,
145 				  struct device_attribute *attr, char *buf);
146 
147 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
148 static struct device_attribute dev_eraseblock_size =
149 	__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
150 static struct device_attribute dev_avail_eraseblocks =
151 	__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
152 static struct device_attribute dev_total_eraseblocks =
153 	__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
154 static struct device_attribute dev_volumes_count =
155 	__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
156 static struct device_attribute dev_max_ec =
157 	__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
158 static struct device_attribute dev_reserved_for_bad =
159 	__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
160 static struct device_attribute dev_bad_peb_count =
161 	__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
162 static struct device_attribute dev_max_vol_count =
163 	__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
164 static struct device_attribute dev_min_io_size =
165 	__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
166 static struct device_attribute dev_bgt_enabled =
167 	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
168 static struct device_attribute dev_mtd_num =
169 	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
170 #endif
171 
172 /**
173  * ubi_volume_notify - send a volume change notification.
174  * @ubi: UBI device description object
175  * @vol: volume description object of the changed volume
176  * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
177  *
178  * This is a helper function which notifies all subscribers about a volume
179  * change event (creation, removal, re-sizing, re-naming, updating). Returns
180  * zero in case of success and a negative error code in case of failure.
181  */
ubi_volume_notify(struct ubi_device * ubi,struct ubi_volume * vol,int ntype)182 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
183 {
184 	int ret;
185 	struct ubi_notification nt;
186 
187 	ubi_do_get_device_info(ubi, &nt.di);
188 	ubi_do_get_volume_info(ubi, vol, &nt.vi);
189 
190 	switch (ntype) {
191 	case UBI_VOLUME_ADDED:
192 	case UBI_VOLUME_REMOVED:
193 	case UBI_VOLUME_RESIZED:
194 	case UBI_VOLUME_RENAMED:
195 		ret = ubi_update_fastmap(ubi);
196 		if (ret)
197 			ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
198 	}
199 
200 	return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
201 }
202 
203 /**
204  * ubi_notify_all - send a notification to all volumes.
205  * @ubi: UBI device description object
206  * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
207  * @nb: the notifier to call
208  *
209  * This function walks all volumes of UBI device @ubi and sends the @ntype
210  * notification for each volume. If @nb is %NULL, then all registered notifiers
211  * are called, otherwise only the @nb notifier is called. Returns the number of
212  * sent notifications.
213  */
ubi_notify_all(struct ubi_device * ubi,int ntype,struct notifier_block * nb)214 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
215 {
216 	struct ubi_notification nt;
217 	int i, count = 0;
218 #ifndef __UBOOT__
219 	int ret;
220 #endif
221 
222 	ubi_do_get_device_info(ubi, &nt.di);
223 
224 	mutex_lock(&ubi->device_mutex);
225 	for (i = 0; i < ubi->vtbl_slots; i++) {
226 		/*
227 		 * Since the @ubi->device is locked, and we are not going to
228 		 * change @ubi->volumes, we do not have to lock
229 		 * @ubi->volumes_lock.
230 		 */
231 		if (!ubi->volumes[i])
232 			continue;
233 
234 		ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
235 #ifndef __UBOOT__
236 		if (nb)
237 			nb->notifier_call(nb, ntype, &nt);
238 		else
239 			ret = blocking_notifier_call_chain(&ubi_notifiers, ntype,
240 						     &nt);
241 #endif
242 		count += 1;
243 	}
244 	mutex_unlock(&ubi->device_mutex);
245 
246 	return count;
247 }
248 
249 /**
250  * ubi_enumerate_volumes - send "add" notification for all existing volumes.
251  * @nb: the notifier to call
252  *
253  * This function walks all UBI devices and volumes and sends the
254  * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
255  * registered notifiers are called, otherwise only the @nb notifier is called.
256  * Returns the number of sent notifications.
257  */
ubi_enumerate_volumes(struct notifier_block * nb)258 int ubi_enumerate_volumes(struct notifier_block *nb)
259 {
260 	int i, count = 0;
261 
262 	/*
263 	 * Since the @ubi_devices_mutex is locked, and we are not going to
264 	 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
265 	 */
266 	for (i = 0; i < UBI_MAX_DEVICES; i++) {
267 		struct ubi_device *ubi = ubi_devices[i];
268 
269 		if (!ubi)
270 			continue;
271 		count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
272 	}
273 
274 	return count;
275 }
276 
277 /**
278  * ubi_get_device - get UBI device.
279  * @ubi_num: UBI device number
280  *
281  * This function returns UBI device description object for UBI device number
282  * @ubi_num, or %NULL if the device does not exist. This function increases the
283  * device reference count to prevent removal of the device. In other words, the
284  * device cannot be removed if its reference count is not zero.
285  */
ubi_get_device(int ubi_num)286 struct ubi_device *ubi_get_device(int ubi_num)
287 {
288 	struct ubi_device *ubi;
289 
290 	spin_lock(&ubi_devices_lock);
291 	ubi = ubi_devices[ubi_num];
292 	if (ubi) {
293 		ubi_assert(ubi->ref_count >= 0);
294 		ubi->ref_count += 1;
295 		get_device(&ubi->dev);
296 	}
297 	spin_unlock(&ubi_devices_lock);
298 
299 	return ubi;
300 }
301 
302 /**
303  * ubi_put_device - drop an UBI device reference.
304  * @ubi: UBI device description object
305  */
ubi_put_device(struct ubi_device * ubi)306 void ubi_put_device(struct ubi_device *ubi)
307 {
308 	spin_lock(&ubi_devices_lock);
309 	ubi->ref_count -= 1;
310 	put_device(&ubi->dev);
311 	spin_unlock(&ubi_devices_lock);
312 }
313 
314 /**
315  * ubi_get_by_major - get UBI device by character device major number.
316  * @major: major number
317  *
318  * This function is similar to 'ubi_get_device()', but it searches the device
319  * by its major number.
320  */
ubi_get_by_major(int major)321 struct ubi_device *ubi_get_by_major(int major)
322 {
323 	int i;
324 	struct ubi_device *ubi;
325 
326 	spin_lock(&ubi_devices_lock);
327 	for (i = 0; i < UBI_MAX_DEVICES; i++) {
328 		ubi = ubi_devices[i];
329 		if (ubi && MAJOR(ubi->cdev.dev) == major) {
330 			ubi_assert(ubi->ref_count >= 0);
331 			ubi->ref_count += 1;
332 			get_device(&ubi->dev);
333 			spin_unlock(&ubi_devices_lock);
334 			return ubi;
335 		}
336 	}
337 	spin_unlock(&ubi_devices_lock);
338 
339 	return NULL;
340 }
341 
342 /**
343  * ubi_major2num - get UBI device number by character device major number.
344  * @major: major number
345  *
346  * This function searches UBI device number object by its major number. If UBI
347  * device was not found, this function returns -ENODEV, otherwise the UBI device
348  * number is returned.
349  */
ubi_major2num(int major)350 int ubi_major2num(int major)
351 {
352 	int i, ubi_num = -ENODEV;
353 
354 	spin_lock(&ubi_devices_lock);
355 	for (i = 0; i < UBI_MAX_DEVICES; i++) {
356 		struct ubi_device *ubi = ubi_devices[i];
357 
358 		if (ubi && MAJOR(ubi->cdev.dev) == major) {
359 			ubi_num = ubi->ubi_num;
360 			break;
361 		}
362 	}
363 	spin_unlock(&ubi_devices_lock);
364 
365 	return ubi_num;
366 }
367 
368 #ifndef __UBOOT__
369 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
dev_attribute_show(struct device * dev,struct device_attribute * attr,char * buf)370 static ssize_t dev_attribute_show(struct device *dev,
371 				  struct device_attribute *attr, char *buf)
372 {
373 	ssize_t ret;
374 	struct ubi_device *ubi;
375 
376 	/*
377 	 * The below code looks weird, but it actually makes sense. We get the
378 	 * UBI device reference from the contained 'struct ubi_device'. But it
379 	 * is unclear if the device was removed or not yet. Indeed, if the
380 	 * device was removed before we increased its reference count,
381 	 * 'ubi_get_device()' will return -ENODEV and we fail.
382 	 *
383 	 * Remember, 'struct ubi_device' is freed in the release function, so
384 	 * we still can use 'ubi->ubi_num'.
385 	 */
386 	ubi = container_of(dev, struct ubi_device, dev);
387 	ubi = ubi_get_device(ubi->ubi_num);
388 	if (!ubi)
389 		return -ENODEV;
390 
391 	if (attr == &dev_eraseblock_size)
392 		ret = sprintf(buf, "%d\n", ubi->leb_size);
393 	else if (attr == &dev_avail_eraseblocks)
394 		ret = sprintf(buf, "%d\n", ubi->avail_pebs);
395 	else if (attr == &dev_total_eraseblocks)
396 		ret = sprintf(buf, "%d\n", ubi->good_peb_count);
397 	else if (attr == &dev_volumes_count)
398 		ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
399 	else if (attr == &dev_max_ec)
400 		ret = sprintf(buf, "%d\n", ubi->max_ec);
401 	else if (attr == &dev_reserved_for_bad)
402 		ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
403 	else if (attr == &dev_bad_peb_count)
404 		ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
405 	else if (attr == &dev_max_vol_count)
406 		ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
407 	else if (attr == &dev_min_io_size)
408 		ret = sprintf(buf, "%d\n", ubi->min_io_size);
409 	else if (attr == &dev_bgt_enabled)
410 		ret = sprintf(buf, "%d\n", ubi->thread_enabled);
411 	else if (attr == &dev_mtd_num)
412 		ret = sprintf(buf, "%d\n", ubi->mtd->index);
413 	else
414 		ret = -EINVAL;
415 
416 	ubi_put_device(ubi);
417 	return ret;
418 }
419 
420 static struct attribute *ubi_dev_attrs[] = {
421 	&dev_eraseblock_size.attr,
422 	&dev_avail_eraseblocks.attr,
423 	&dev_total_eraseblocks.attr,
424 	&dev_volumes_count.attr,
425 	&dev_max_ec.attr,
426 	&dev_reserved_for_bad.attr,
427 	&dev_bad_peb_count.attr,
428 	&dev_max_vol_count.attr,
429 	&dev_min_io_size.attr,
430 	&dev_bgt_enabled.attr,
431 	&dev_mtd_num.attr,
432 	NULL
433 };
434 ATTRIBUTE_GROUPS(ubi_dev);
435 
dev_release(struct device * dev)436 static void dev_release(struct device *dev)
437 {
438 	struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
439 
440 	kfree(ubi);
441 }
442 
443 /**
444  * ubi_sysfs_init - initialize sysfs for an UBI device.
445  * @ubi: UBI device description object
446  * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
447  *       taken
448  *
449  * This function returns zero in case of success and a negative error code in
450  * case of failure.
451  */
ubi_sysfs_init(struct ubi_device * ubi,int * ref)452 static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
453 {
454 	int err;
455 
456 	ubi->dev.release = dev_release;
457 	ubi->dev.devt = ubi->cdev.dev;
458 	ubi->dev.class = &ubi_class;
459 	ubi->dev.groups = ubi_dev_groups;
460 	dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
461 	err = device_register(&ubi->dev);
462 	if (err)
463 		return err;
464 
465 	*ref = 1;
466 	return 0;
467 }
468 
469 /**
470  * ubi_sysfs_close - close sysfs for an UBI device.
471  * @ubi: UBI device description object
472  */
ubi_sysfs_close(struct ubi_device * ubi)473 static void ubi_sysfs_close(struct ubi_device *ubi)
474 {
475 	device_unregister(&ubi->dev);
476 }
477 #endif
478 
479 /**
480  * kill_volumes - destroy all user volumes.
481  * @ubi: UBI device description object
482  */
kill_volumes(struct ubi_device * ubi)483 static void kill_volumes(struct ubi_device *ubi)
484 {
485 	int i;
486 
487 	for (i = 0; i < ubi->vtbl_slots; i++)
488 		if (ubi->volumes[i])
489 			ubi_free_volume(ubi, ubi->volumes[i]);
490 }
491 
492 /**
493  * uif_init - initialize user interfaces for an UBI device.
494  * @ubi: UBI device description object
495  * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
496  *       taken, otherwise set to %0
497  *
498  * This function initializes various user interfaces for an UBI device. If the
499  * initialization fails at an early stage, this function frees all the
500  * resources it allocated, returns an error, and @ref is set to %0. However,
501  * if the initialization fails after the UBI device was registered in the
502  * driver core subsystem, this function takes a reference to @ubi->dev, because
503  * otherwise the release function ('dev_release()') would free whole @ubi
504  * object. The @ref argument is set to %1 in this case. The caller has to put
505  * this reference.
506  *
507  * This function returns zero in case of success and a negative error code in
508  * case of failure.
509  */
uif_init(struct ubi_device * ubi,int * ref)510 static int uif_init(struct ubi_device *ubi, int *ref)
511 {
512 	int i, err;
513 #ifndef __UBOOT__
514 	dev_t dev;
515 #endif
516 
517 	*ref = 0;
518 	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
519 
520 	/*
521 	 * Major numbers for the UBI character devices are allocated
522 	 * dynamically. Major numbers of volume character devices are
523 	 * equivalent to ones of the corresponding UBI character device. Minor
524 	 * numbers of UBI character devices are 0, while minor numbers of
525 	 * volume character devices start from 1. Thus, we allocate one major
526 	 * number and ubi->vtbl_slots + 1 minor numbers.
527 	 */
528 	err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
529 	if (err) {
530 		ubi_err(ubi, "cannot register UBI character devices");
531 		return err;
532 	}
533 
534 	ubi_assert(MINOR(dev) == 0);
535 	cdev_init(&ubi->cdev, &ubi_cdev_operations);
536 	dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
537 	ubi->cdev.owner = THIS_MODULE;
538 
539 	err = cdev_add(&ubi->cdev, dev, 1);
540 	if (err) {
541 		ubi_err(ubi, "cannot add character device");
542 		goto out_unreg;
543 	}
544 
545 	err = ubi_sysfs_init(ubi, ref);
546 	if (err)
547 		goto out_sysfs;
548 
549 	for (i = 0; i < ubi->vtbl_slots; i++)
550 		if (ubi->volumes[i]) {
551 			err = ubi_add_volume(ubi, ubi->volumes[i]);
552 			if (err) {
553 				ubi_err(ubi, "cannot add volume %d", i);
554 				goto out_volumes;
555 			}
556 		}
557 
558 	return 0;
559 
560 out_volumes:
561 	kill_volumes(ubi);
562 out_sysfs:
563 	if (*ref)
564 		get_device(&ubi->dev);
565 	ubi_sysfs_close(ubi);
566 	cdev_del(&ubi->cdev);
567 out_unreg:
568 	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
569 	ubi_err(ubi, "cannot initialize UBI %s, error %d",
570 		ubi->ubi_name, err);
571 	return err;
572 }
573 
574 /**
575  * uif_close - close user interfaces for an UBI device.
576  * @ubi: UBI device description object
577  *
578  * Note, since this function un-registers UBI volume device objects (@vol->dev),
579  * the memory allocated voe the volumes is freed as well (in the release
580  * function).
581  */
uif_close(struct ubi_device * ubi)582 static void uif_close(struct ubi_device *ubi)
583 {
584 	kill_volumes(ubi);
585 	ubi_sysfs_close(ubi);
586 	cdev_del(&ubi->cdev);
587 	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
588 }
589 
590 /**
591  * ubi_free_internal_volumes - free internal volumes.
592  * @ubi: UBI device description object
593  */
ubi_free_internal_volumes(struct ubi_device * ubi)594 void ubi_free_internal_volumes(struct ubi_device *ubi)
595 {
596 	int i;
597 
598 	for (i = ubi->vtbl_slots;
599 	     i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
600 		kfree(ubi->volumes[i]->eba_tbl);
601 		kfree(ubi->volumes[i]);
602 	}
603 }
604 
get_bad_peb_limit(const struct ubi_device * ubi,int max_beb_per1024)605 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
606 {
607 	int limit, device_pebs;
608 	uint64_t device_size;
609 
610 	if (!max_beb_per1024)
611 		return 0;
612 
613 	/*
614 	 * Here we are using size of the entire flash chip and
615 	 * not just the MTD partition size because the maximum
616 	 * number of bad eraseblocks is a percentage of the
617 	 * whole device and bad eraseblocks are not fairly
618 	 * distributed over the flash chip. So the worst case
619 	 * is that all the bad eraseblocks of the chip are in
620 	 * the MTD partition we are attaching (ubi->mtd).
621 	 */
622 	device_size = mtd_get_device_size(ubi->mtd);
623 	device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
624 	limit = mult_frac(device_pebs, max_beb_per1024, 1024);
625 
626 	/* Round it up */
627 	if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
628 		limit += 1;
629 
630 	return limit;
631 }
632 
633 /**
634  * io_init - initialize I/O sub-system for a given UBI device.
635  * @ubi: UBI device description object
636  * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
637  *
638  * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
639  * assumed:
640  *   o EC header is always at offset zero - this cannot be changed;
641  *   o VID header starts just after the EC header at the closest address
642  *     aligned to @io->hdrs_min_io_size;
643  *   o data starts just after the VID header at the closest address aligned to
644  *     @io->min_io_size
645  *
646  * This function returns zero in case of success and a negative error code in
647  * case of failure.
648  */
io_init(struct ubi_device * ubi,int max_beb_per1024)649 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
650 {
651 	dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
652 	dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
653 
654 	if (ubi->mtd->numeraseregions != 0) {
655 		/*
656 		 * Some flashes have several erase regions. Different regions
657 		 * may have different eraseblock size and other
658 		 * characteristics. It looks like mostly multi-region flashes
659 		 * have one "main" region and one or more small regions to
660 		 * store boot loader code or boot parameters or whatever. I
661 		 * guess we should just pick the largest region. But this is
662 		 * not implemented.
663 		 */
664 		ubi_err(ubi, "multiple regions, not implemented");
665 		return -EINVAL;
666 	}
667 
668 	if (ubi->vid_hdr_offset < 0)
669 		return -EINVAL;
670 
671 	/*
672 	 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
673 	 * physical eraseblocks maximum.
674 	 */
675 
676 	ubi->peb_size   = ubi->mtd->erasesize;
677 	ubi->peb_count  = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
678 	ubi->flash_size = ubi->mtd->size;
679 
680 	if (mtd_can_have_bb(ubi->mtd)) {
681 		ubi->bad_allowed = 1;
682 		ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
683 	}
684 
685 	if (ubi->mtd->type == MTD_NORFLASH) {
686 		ubi_assert(ubi->mtd->writesize == 1);
687 		ubi->nor_flash = 1;
688 	}
689 
690 	ubi->min_io_size = ubi->mtd->writesize;
691 	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
692 
693 	/*
694 	 * Make sure minimal I/O unit is power of 2. Note, there is no
695 	 * fundamental reason for this assumption. It is just an optimization
696 	 * which allows us to avoid costly division operations.
697 	 */
698 	if (!is_power_of_2(ubi->min_io_size)) {
699 		ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
700 			ubi->min_io_size);
701 		return -EINVAL;
702 	}
703 
704 	ubi_assert(ubi->hdrs_min_io_size > 0);
705 	ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
706 	ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
707 
708 	ubi->max_write_size = ubi->mtd->writebufsize;
709 	/*
710 	 * Maximum write size has to be greater or equivalent to min. I/O
711 	 * size, and be multiple of min. I/O size.
712 	 */
713 	if (ubi->max_write_size < ubi->min_io_size ||
714 	    ubi->max_write_size % ubi->min_io_size ||
715 	    !is_power_of_2(ubi->max_write_size)) {
716 		ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
717 			ubi->max_write_size, ubi->min_io_size);
718 		return -EINVAL;
719 	}
720 
721 	/* Calculate default aligned sizes of EC and VID headers */
722 	ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
723 	ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
724 
725 	dbg_gen("min_io_size      %d", ubi->min_io_size);
726 	dbg_gen("max_write_size   %d", ubi->max_write_size);
727 	dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
728 	dbg_gen("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
729 	dbg_gen("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
730 
731 	if (ubi->vid_hdr_offset == 0)
732 		/* Default offset */
733 		ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
734 				      ubi->ec_hdr_alsize;
735 	else {
736 		ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
737 						~(ubi->hdrs_min_io_size - 1);
738 		ubi->vid_hdr_shift = ubi->vid_hdr_offset -
739 						ubi->vid_hdr_aloffset;
740 	}
741 
742 	/* Similar for the data offset */
743 	ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
744 	ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
745 
746 	dbg_gen("vid_hdr_offset   %d", ubi->vid_hdr_offset);
747 	dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
748 	dbg_gen("vid_hdr_shift    %d", ubi->vid_hdr_shift);
749 	dbg_gen("leb_start        %d", ubi->leb_start);
750 
751 	/* The shift must be aligned to 32-bit boundary */
752 	if (ubi->vid_hdr_shift % 4) {
753 		ubi_err(ubi, "unaligned VID header shift %d",
754 			ubi->vid_hdr_shift);
755 		return -EINVAL;
756 	}
757 
758 	/* Check sanity */
759 	if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
760 	    ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
761 	    ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
762 	    ubi->leb_start & (ubi->min_io_size - 1)) {
763 		ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
764 			ubi->vid_hdr_offset, ubi->leb_start);
765 		return -EINVAL;
766 	}
767 
768 	/*
769 	 * Set maximum amount of physical erroneous eraseblocks to be 10%.
770 	 * Erroneous PEB are those which have read errors.
771 	 */
772 	ubi->max_erroneous = ubi->peb_count / 10;
773 	if (ubi->max_erroneous < 16)
774 		ubi->max_erroneous = 16;
775 	dbg_gen("max_erroneous    %d", ubi->max_erroneous);
776 
777 	/*
778 	 * It may happen that EC and VID headers are situated in one minimal
779 	 * I/O unit. In this case we can only accept this UBI image in
780 	 * read-only mode.
781 	 */
782 	if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
783 		ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
784 		ubi->ro_mode = 1;
785 	}
786 
787 	ubi->leb_size = ubi->peb_size - ubi->leb_start;
788 
789 	if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
790 		ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
791 			ubi->mtd->index);
792 		ubi->ro_mode = 1;
793 	}
794 
795 	/*
796 	 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
797 	 * unfortunately, MTD does not provide this information. We should loop
798 	 * over all physical eraseblocks and invoke mtd->block_is_bad() for
799 	 * each physical eraseblock. So, we leave @ubi->bad_peb_count
800 	 * uninitialized so far.
801 	 */
802 
803 	return 0;
804 }
805 
806 /**
807  * autoresize - re-size the volume which has the "auto-resize" flag set.
808  * @ubi: UBI device description object
809  * @vol_id: ID of the volume to re-size
810  *
811  * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
812  * the volume table to the largest possible size. See comments in ubi-header.h
813  * for more description of the flag. Returns zero in case of success and a
814  * negative error code in case of failure.
815  */
autoresize(struct ubi_device * ubi,int vol_id)816 static int autoresize(struct ubi_device *ubi, int vol_id)
817 {
818 	struct ubi_volume_desc desc;
819 	struct ubi_volume *vol = ubi->volumes[vol_id];
820 	int err, old_reserved_pebs = vol->reserved_pebs;
821 
822 	if (ubi->ro_mode) {
823 		ubi_warn(ubi, "skip auto-resize because of R/O mode");
824 		return 0;
825 	}
826 
827 	/*
828 	 * Clear the auto-resize flag in the volume in-memory copy of the
829 	 * volume table, and 'ubi_resize_volume()' will propagate this change
830 	 * to the flash.
831 	 */
832 	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
833 
834 	if (ubi->avail_pebs == 0) {
835 		struct ubi_vtbl_record vtbl_rec;
836 
837 		/*
838 		 * No available PEBs to re-size the volume, clear the flag on
839 		 * flash and exit.
840 		 */
841 		vtbl_rec = ubi->vtbl[vol_id];
842 		err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
843 		if (err)
844 			ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
845 				vol_id);
846 	} else {
847 		desc.vol = vol;
848 		err = ubi_resize_volume(&desc,
849 					old_reserved_pebs + ubi->avail_pebs);
850 		if (err)
851 			ubi_err(ubi, "cannot auto-resize volume %d",
852 				vol_id);
853 	}
854 
855 	if (err)
856 		return err;
857 
858 	ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
859 		vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
860 	return 0;
861 }
862 
863 /**
864  * ubi_attach_mtd_dev - attach an MTD device.
865  * @mtd: MTD device description object
866  * @ubi_num: number to assign to the new UBI device
867  * @vid_hdr_offset: VID header offset
868  * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
869  *
870  * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
871  * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
872  * which case this function finds a vacant device number and assigns it
873  * automatically. Returns the new UBI device number in case of success and a
874  * negative error code in case of failure.
875  *
876  * Note, the invocations of this function has to be serialized by the
877  * @ubi_devices_mutex.
878  */
ubi_attach_mtd_dev(struct mtd_info * mtd,int ubi_num,int vid_hdr_offset,int max_beb_per1024)879 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
880 		       int vid_hdr_offset, int max_beb_per1024)
881 {
882 	struct ubi_device *ubi;
883 	int i, err, ref = 0;
884 
885 	if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
886 		return -EINVAL;
887 
888 	if (!max_beb_per1024)
889 		max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
890 
891 	/*
892 	 * Check if we already have the same MTD device attached.
893 	 *
894 	 * Note, this function assumes that UBI devices creations and deletions
895 	 * are serialized, so it does not take the &ubi_devices_lock.
896 	 */
897 	for (i = 0; i < UBI_MAX_DEVICES; i++) {
898 		ubi = ubi_devices[i];
899 		if (ubi && mtd->index == ubi->mtd->index) {
900 			ubi_err(ubi, "mtd%d is already attached to ubi%d",
901 				mtd->index, i);
902 			return -EEXIST;
903 		}
904 	}
905 
906 	/*
907 	 * Make sure this MTD device is not emulated on top of an UBI volume
908 	 * already. Well, generally this recursion works fine, but there are
909 	 * different problems like the UBI module takes a reference to itself
910 	 * by attaching (and thus, opening) the emulated MTD device. This
911 	 * results in inability to unload the module. And in general it makes
912 	 * no sense to attach emulated MTD devices, so we prohibit this.
913 	 */
914 	if (mtd->type == MTD_UBIVOLUME) {
915 		ubi_err(ubi, "refuse attaching mtd%d - it is already emulated on top of UBI",
916 			mtd->index);
917 		return -EINVAL;
918 	}
919 
920 	if (ubi_num == UBI_DEV_NUM_AUTO) {
921 		/* Search for an empty slot in the @ubi_devices array */
922 		for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
923 			if (!ubi_devices[ubi_num])
924 				break;
925 		if (ubi_num == UBI_MAX_DEVICES) {
926 			ubi_err(ubi, "only %d UBI devices may be created",
927 				UBI_MAX_DEVICES);
928 			return -ENFILE;
929 		}
930 	} else {
931 		if (ubi_num >= UBI_MAX_DEVICES)
932 			return -EINVAL;
933 
934 		/* Make sure ubi_num is not busy */
935 		if (ubi_devices[ubi_num]) {
936 			ubi_err(ubi, "already exists");
937 			return -EEXIST;
938 		}
939 	}
940 
941 	ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
942 	if (!ubi)
943 		return -ENOMEM;
944 
945 	ubi->mtd = mtd;
946 	ubi->ubi_num = ubi_num;
947 	ubi->vid_hdr_offset = vid_hdr_offset;
948 	ubi->autoresize_vol_id = -1;
949 
950 #ifdef CONFIG_MTD_UBI_FASTMAP
951 	ubi->fm_pool.used = ubi->fm_pool.size = 0;
952 	ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
953 
954 	/*
955 	 * fm_pool.max_size is 5% of the total number of PEBs but it's also
956 	 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
957 	 */
958 	ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
959 		ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
960 	ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
961 		UBI_FM_MIN_POOL_SIZE);
962 
963 	ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
964 	ubi->fm_disabled = !fm_autoconvert;
965 	if (fm_debug)
966 		ubi_enable_dbg_chk_fastmap(ubi);
967 
968 	if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
969 	    <= UBI_FM_MAX_START) {
970 		ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
971 			UBI_FM_MAX_START);
972 		ubi->fm_disabled = 1;
973 	}
974 
975 	ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
976 	ubi_msg(ubi, "default fastmap WL pool size: %d",
977 		ubi->fm_wl_pool.max_size);
978 #else
979 	ubi->fm_disabled = 1;
980 #endif
981 	mutex_init(&ubi->buf_mutex);
982 	mutex_init(&ubi->ckvol_mutex);
983 	mutex_init(&ubi->device_mutex);
984 	spin_lock_init(&ubi->volumes_lock);
985 	init_rwsem(&ubi->fm_protect);
986 	init_rwsem(&ubi->fm_eba_sem);
987 
988 	ubi_msg(ubi, "attaching mtd%d", mtd->index);
989 
990 	err = io_init(ubi, max_beb_per1024);
991 	if (err)
992 		goto out_free;
993 
994 	err = -ENOMEM;
995 	ubi->peb_buf = vmalloc(ubi->peb_size);
996 	if (!ubi->peb_buf)
997 		goto out_free;
998 
999 #ifdef CONFIG_MTD_UBI_FASTMAP
1000 	ubi->fm_size = ubi_calc_fm_size(ubi);
1001 	ubi->fm_buf = vzalloc(ubi->fm_size);
1002 	if (!ubi->fm_buf)
1003 		goto out_free;
1004 #endif
1005 	err = ubi_attach(ubi, 0);
1006 	if (err) {
1007 		ubi_err(ubi, "failed to attach mtd%d, error %d",
1008 			mtd->index, err);
1009 		goto out_free;
1010 	}
1011 
1012 	if (ubi->autoresize_vol_id != -1) {
1013 		err = autoresize(ubi, ubi->autoresize_vol_id);
1014 		if (err)
1015 			goto out_detach;
1016 	}
1017 
1018 	err = uif_init(ubi, &ref);
1019 	if (err)
1020 		goto out_detach;
1021 
1022 	err = ubi_debugfs_init_dev(ubi);
1023 	if (err)
1024 		goto out_uif;
1025 
1026 	ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
1027 	if (IS_ERR(ubi->bgt_thread)) {
1028 		err = PTR_ERR(ubi->bgt_thread);
1029 		ubi_err(ubi, "cannot spawn \"%s\", error %d",
1030 			ubi->bgt_name, err);
1031 		goto out_debugfs;
1032 	}
1033 
1034 	ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
1035 		mtd->index, mtd->name, ubi->flash_size >> 20);
1036 	ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
1037 		ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
1038 	ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
1039 		ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1040 	ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1041 		ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1042 	ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1043 		ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1044 	ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1045 		ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1046 		ubi->vtbl_slots);
1047 	ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1048 		ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1049 		ubi->image_seq);
1050 	ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1051 		ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1052 
1053 	/*
1054 	 * The below lock makes sure we do not race with 'ubi_thread()' which
1055 	 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1056 	 */
1057 	spin_lock(&ubi->wl_lock);
1058 	ubi->thread_enabled = 1;
1059 #ifndef __UBOOT__
1060 	wake_up_process(ubi->bgt_thread);
1061 #else
1062 	ubi_do_worker(ubi);
1063 #endif
1064 
1065 	spin_unlock(&ubi->wl_lock);
1066 
1067 	ubi_devices[ubi_num] = ubi;
1068 	ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1069 	return ubi_num;
1070 
1071 out_debugfs:
1072 	ubi_debugfs_exit_dev(ubi);
1073 out_uif:
1074 	get_device(&ubi->dev);
1075 	ubi_assert(ref);
1076 	uif_close(ubi);
1077 out_detach:
1078 	ubi_wl_close(ubi);
1079 	ubi_free_internal_volumes(ubi);
1080 	vfree(ubi->vtbl);
1081 out_free:
1082 	vfree(ubi->peb_buf);
1083 	vfree(ubi->fm_buf);
1084 	if (ref)
1085 		put_device(&ubi->dev);
1086 	else
1087 		kfree(ubi);
1088 	return err;
1089 }
1090 
1091 /**
1092  * ubi_detach_mtd_dev - detach an MTD device.
1093  * @ubi_num: UBI device number to detach from
1094  * @anyway: detach MTD even if device reference count is not zero
1095  *
1096  * This function destroys an UBI device number @ubi_num and detaches the
1097  * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1098  * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1099  * exist.
1100  *
1101  * Note, the invocations of this function has to be serialized by the
1102  * @ubi_devices_mutex.
1103  */
ubi_detach_mtd_dev(int ubi_num,int anyway)1104 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1105 {
1106 	struct ubi_device *ubi;
1107 
1108 	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1109 		return -EINVAL;
1110 
1111 	ubi = ubi_get_device(ubi_num);
1112 	if (!ubi)
1113 		return -EINVAL;
1114 
1115 	spin_lock(&ubi_devices_lock);
1116 	put_device(&ubi->dev);
1117 	ubi->ref_count -= 1;
1118 	if (ubi->ref_count) {
1119 		if (!anyway) {
1120 			spin_unlock(&ubi_devices_lock);
1121 			return -EBUSY;
1122 		}
1123 		/* This may only happen if there is a bug */
1124 		ubi_err(ubi, "%s reference count %d, destroy anyway",
1125 			ubi->ubi_name, ubi->ref_count);
1126 	}
1127 	ubi_devices[ubi_num] = NULL;
1128 	spin_unlock(&ubi_devices_lock);
1129 
1130 	ubi_assert(ubi_num == ubi->ubi_num);
1131 	ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1132 	ubi_msg(ubi, "detaching mtd%d", ubi->mtd->index);
1133 #ifdef CONFIG_MTD_UBI_FASTMAP
1134 	/* If we don't write a new fastmap at detach time we lose all
1135 	 * EC updates that have been made since the last written fastmap.
1136 	 * In case of fastmap debugging we omit the update to simulate an
1137 	 * unclean shutdown. */
1138 	if (!ubi_dbg_chk_fastmap(ubi))
1139 		ubi_update_fastmap(ubi);
1140 #endif
1141 	/*
1142 	 * Before freeing anything, we have to stop the background thread to
1143 	 * prevent it from doing anything on this device while we are freeing.
1144 	 */
1145 	if (ubi->bgt_thread)
1146 		kthread_stop(ubi->bgt_thread);
1147 
1148 	/*
1149 	 * Get a reference to the device in order to prevent 'dev_release()'
1150 	 * from freeing the @ubi object.
1151 	 */
1152 	get_device(&ubi->dev);
1153 
1154 	ubi_debugfs_exit_dev(ubi);
1155 	uif_close(ubi);
1156 
1157 	ubi_wl_close(ubi);
1158 	ubi_free_internal_volumes(ubi);
1159 	vfree(ubi->vtbl);
1160 	put_mtd_device(ubi->mtd);
1161 	vfree(ubi->peb_buf);
1162 	vfree(ubi->fm_buf);
1163 	ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1164 	put_device(&ubi->dev);
1165 	return 0;
1166 }
1167 
1168 #ifndef __UBOOT__
1169 /**
1170  * open_mtd_by_chdev - open an MTD device by its character device node path.
1171  * @mtd_dev: MTD character device node path
1172  *
1173  * This helper function opens an MTD device by its character node device path.
1174  * Returns MTD device description object in case of success and a negative
1175  * error code in case of failure.
1176  */
open_mtd_by_chdev(const char * mtd_dev)1177 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1178 {
1179 	int err, major, minor, mode;
1180 	struct path path;
1181 
1182 	/* Probably this is an MTD character device node path */
1183 	err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1184 	if (err)
1185 		return ERR_PTR(err);
1186 
1187 	/* MTD device number is defined by the major / minor numbers */
1188 	major = imajor(d_backing_inode(path.dentry));
1189 	minor = iminor(d_backing_inode(path.dentry));
1190 	mode = d_backing_inode(path.dentry)->i_mode;
1191 	path_put(&path);
1192 	if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))
1193 		return ERR_PTR(-EINVAL);
1194 
1195 	if (minor & 1)
1196 		/*
1197 		 * Just do not think the "/dev/mtdrX" devices support is need,
1198 		 * so do not support them to avoid doing extra work.
1199 		 */
1200 		return ERR_PTR(-EINVAL);
1201 
1202 	return get_mtd_device(NULL, minor / 2);
1203 }
1204 #endif
1205 
1206 /**
1207  * open_mtd_device - open MTD device by name, character device path, or number.
1208  * @mtd_dev: name, character device node path, or MTD device device number
1209  *
1210  * This function tries to open and MTD device described by @mtd_dev string,
1211  * which is first treated as ASCII MTD device number, and if it is not true, it
1212  * is treated as MTD device name, and if that is also not true, it is treated
1213  * as MTD character device node path. Returns MTD device description object in
1214  * case of success and a negative error code in case of failure.
1215  */
open_mtd_device(const char * mtd_dev)1216 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1217 {
1218 	struct mtd_info *mtd;
1219 	int mtd_num;
1220 	char *endp;
1221 
1222 	mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1223 	if (*endp != '\0' || mtd_dev == endp) {
1224 		/*
1225 		 * This does not look like an ASCII integer, probably this is
1226 		 * MTD device name.
1227 		 */
1228 		mtd = get_mtd_device_nm(mtd_dev);
1229 #ifndef __UBOOT__
1230 		if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV)
1231 			/* Probably this is an MTD character device node path */
1232 			mtd = open_mtd_by_chdev(mtd_dev);
1233 #endif
1234 	} else
1235 		mtd = get_mtd_device(NULL, mtd_num);
1236 
1237 	return mtd;
1238 }
1239 
1240 #ifndef __UBOOT__
ubi_init(void)1241 static int __init ubi_init(void)
1242 #else
1243 int ubi_init(void)
1244 #endif
1245 {
1246 	int err, i, k;
1247 
1248 	/* Ensure that EC and VID headers have correct size */
1249 	BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1250 	BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1251 
1252 	if (mtd_devs > UBI_MAX_DEVICES) {
1253 		pr_err("UBI error: too many MTD devices, maximum is %d\n",
1254 		       UBI_MAX_DEVICES);
1255 		return -EINVAL;
1256 	}
1257 
1258 	/* Create base sysfs directory and sysfs files */
1259 	err = class_register(&ubi_class);
1260 	if (err < 0)
1261 		return err;
1262 
1263 	err = misc_register(&ubi_ctrl_cdev);
1264 	if (err) {
1265 		pr_err("UBI error: cannot register device\n");
1266 		goto out;
1267 	}
1268 
1269 	ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1270 					      sizeof(struct ubi_wl_entry),
1271 					      0, 0, NULL);
1272 	if (!ubi_wl_entry_slab) {
1273 		err = -ENOMEM;
1274 		goto out_dev_unreg;
1275 	}
1276 
1277 	err = ubi_debugfs_init();
1278 	if (err)
1279 		goto out_slab;
1280 
1281 
1282 	/* Attach MTD devices */
1283 	for (i = 0; i < mtd_devs; i++) {
1284 		struct mtd_dev_param *p = &mtd_dev_param[i];
1285 		struct mtd_info *mtd;
1286 
1287 		cond_resched();
1288 
1289 		mtd = open_mtd_device(p->name);
1290 		if (IS_ERR(mtd)) {
1291 			err = PTR_ERR(mtd);
1292 			pr_err("UBI error: cannot open mtd %s, error %d\n",
1293 			       p->name, err);
1294 			/* See comment below re-ubi_is_module(). */
1295 			if (ubi_is_module())
1296 				goto out_detach;
1297 			continue;
1298 		}
1299 
1300 		mutex_lock(&ubi_devices_mutex);
1301 		err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1302 					 p->vid_hdr_offs, p->max_beb_per1024);
1303 		mutex_unlock(&ubi_devices_mutex);
1304 		if (err < 0) {
1305 			pr_err("UBI error: cannot attach mtd%d\n",
1306 			       mtd->index);
1307 			put_mtd_device(mtd);
1308 
1309 			/*
1310 			 * Originally UBI stopped initializing on any error.
1311 			 * However, later on it was found out that this
1312 			 * behavior is not very good when UBI is compiled into
1313 			 * the kernel and the MTD devices to attach are passed
1314 			 * through the command line. Indeed, UBI failure
1315 			 * stopped whole boot sequence.
1316 			 *
1317 			 * To fix this, we changed the behavior for the
1318 			 * non-module case, but preserved the old behavior for
1319 			 * the module case, just for compatibility. This is a
1320 			 * little inconsistent, though.
1321 			 */
1322 			if (ubi_is_module())
1323 				goto out_detach;
1324 		}
1325 	}
1326 
1327 	err = ubiblock_init();
1328 	if (err) {
1329 		pr_err("UBI error: block: cannot initialize, error %d\n", err);
1330 
1331 		/* See comment above re-ubi_is_module(). */
1332 		if (ubi_is_module())
1333 			goto out_detach;
1334 	}
1335 
1336 	return 0;
1337 
1338 out_detach:
1339 	for (k = 0; k < i; k++)
1340 		if (ubi_devices[k]) {
1341 			mutex_lock(&ubi_devices_mutex);
1342 			ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1343 			mutex_unlock(&ubi_devices_mutex);
1344 		}
1345 	ubi_debugfs_exit();
1346 out_slab:
1347 	kmem_cache_destroy(ubi_wl_entry_slab);
1348 out_dev_unreg:
1349 	misc_deregister(&ubi_ctrl_cdev);
1350 out:
1351 #ifdef __UBOOT__
1352 	/* Reset any globals that the driver depends on being zeroed */
1353 	mtd_devs = 0;
1354 #endif
1355 	class_unregister(&ubi_class);
1356 	pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1357 	return err;
1358 }
1359 late_initcall(ubi_init);
1360 
1361 #ifndef __UBOOT__
ubi_exit(void)1362 static void __exit ubi_exit(void)
1363 #else
1364 void ubi_exit(void)
1365 #endif
1366 {
1367 	int i;
1368 
1369 	ubiblock_exit();
1370 
1371 	for (i = 0; i < UBI_MAX_DEVICES; i++)
1372 		if (ubi_devices[i]) {
1373 			mutex_lock(&ubi_devices_mutex);
1374 			ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1375 			mutex_unlock(&ubi_devices_mutex);
1376 		}
1377 	ubi_debugfs_exit();
1378 	kmem_cache_destroy(ubi_wl_entry_slab);
1379 	misc_deregister(&ubi_ctrl_cdev);
1380 	class_unregister(&ubi_class);
1381 #ifdef __UBOOT__
1382 	/* Reset any globals that the driver depends on being zeroed */
1383 	mtd_devs = 0;
1384 #endif
1385 }
1386 module_exit(ubi_exit);
1387 
1388 /**
1389  * bytes_str_to_int - convert a number of bytes string into an integer.
1390  * @str: the string to convert
1391  *
1392  * This function returns positive resulting integer in case of success and a
1393  * negative error code in case of failure.
1394  */
bytes_str_to_int(const char * str)1395 static int __init bytes_str_to_int(const char *str)
1396 {
1397 	char *endp;
1398 	unsigned long result;
1399 
1400 	result = simple_strtoul(str, &endp, 0);
1401 	if (str == endp || result >= INT_MAX) {
1402 		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1403 		return -EINVAL;
1404 	}
1405 
1406 	switch (*endp) {
1407 	case 'G':
1408 		result *= 1024;
1409 	case 'M':
1410 		result *= 1024;
1411 	case 'K':
1412 		result *= 1024;
1413 		if (endp[1] == 'i' && endp[2] == 'B')
1414 			endp += 2;
1415 	case '\0':
1416 		break;
1417 	default:
1418 		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1419 		return -EINVAL;
1420 	}
1421 
1422 	return result;
1423 }
1424 
kstrtoint(const char * s,unsigned int base,int * res)1425 int kstrtoint(const char *s, unsigned int base, int *res)
1426 {
1427 	unsigned long long tmp;
1428 
1429 	tmp = simple_strtoull(s, NULL, base);
1430 	if (tmp != (unsigned long long)(int)tmp)
1431 		return -ERANGE;
1432 
1433 	return (int)tmp;
1434 }
1435 
1436 /**
1437  * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1438  * @val: the parameter value to parse
1439  * @kp: not used
1440  *
1441  * This function returns zero in case of success and a negative error code in
1442  * case of error.
1443  */
1444 #ifndef __UBOOT__
ubi_mtd_param_parse(const char * val,struct kernel_param * kp)1445 static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1446 #else
1447 int ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1448 #endif
1449 {
1450 	int i, len;
1451 	struct mtd_dev_param *p;
1452 	char buf[MTD_PARAM_LEN_MAX];
1453 	char *pbuf = &buf[0];
1454 	char *tokens[MTD_PARAM_MAX_COUNT], *token;
1455 
1456 	if (!val)
1457 		return -EINVAL;
1458 
1459 	if (mtd_devs == UBI_MAX_DEVICES) {
1460 		pr_err("UBI error: too many parameters, max. is %d\n",
1461 		       UBI_MAX_DEVICES);
1462 		return -EINVAL;
1463 	}
1464 
1465 	len = strnlen(val, MTD_PARAM_LEN_MAX);
1466 	if (len == MTD_PARAM_LEN_MAX) {
1467 		pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1468 		       val, MTD_PARAM_LEN_MAX);
1469 		return -EINVAL;
1470 	}
1471 
1472 	if (len == 0) {
1473 		pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1474 		return 0;
1475 	}
1476 
1477 	strcpy(buf, val);
1478 
1479 	/* Get rid of the final newline */
1480 	if (buf[len - 1] == '\n')
1481 		buf[len - 1] = '\0';
1482 
1483 	for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1484 		tokens[i] = strsep(&pbuf, ",");
1485 
1486 	if (pbuf) {
1487 		pr_err("UBI error: too many arguments at \"%s\"\n", val);
1488 		return -EINVAL;
1489 	}
1490 
1491 	p = &mtd_dev_param[mtd_devs];
1492 	strcpy(&p->name[0], tokens[0]);
1493 
1494 	token = tokens[1];
1495 	if (token) {
1496 		p->vid_hdr_offs = bytes_str_to_int(token);
1497 
1498 		if (p->vid_hdr_offs < 0)
1499 			return p->vid_hdr_offs;
1500 	}
1501 
1502 	token = tokens[2];
1503 	if (token) {
1504 		int err = kstrtoint(token, 10, &p->max_beb_per1024);
1505 
1506 		if (err) {
1507 			pr_err("UBI error: bad value for max_beb_per1024 parameter: %s",
1508 			       token);
1509 			return -EINVAL;
1510 		}
1511 	}
1512 
1513 	token = tokens[3];
1514 	if (token) {
1515 		int err = kstrtoint(token, 10, &p->ubi_num);
1516 
1517 		if (err) {
1518 			pr_err("UBI error: bad value for ubi_num parameter: %s",
1519 			       token);
1520 			return -EINVAL;
1521 		}
1522 	} else
1523 		p->ubi_num = UBI_DEV_NUM_AUTO;
1524 
1525 	mtd_devs += 1;
1526 	return 0;
1527 }
1528 
1529 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1530 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1531 		      "Multiple \"mtd\" parameters may be specified.\n"
1532 		      "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1533 		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1534 		      "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1535 		      __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1536 		      "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1537 		      "\n"
1538 		      "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1539 		      "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"
1540 		      "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"
1541 		      "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"
1542 		      "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1543 #ifdef CONFIG_MTD_UBI_FASTMAP
1544 module_param(fm_autoconvert, bool, 0644);
1545 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1546 module_param(fm_debug, bool, 0);
1547 MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1548 #endif
1549 MODULE_VERSION(__stringify(UBI_VERSION));
1550 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1551 MODULE_AUTHOR("Artem Bityutskiy");
1552 MODULE_LICENSE("GPL");
1553