1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (c) International Business Machines Corp., 2006
4 * Copyright (c) Nokia Corporation, 2007
6 * Author: Artem Bityutskiy (Битюцкий Артём),
11 * This file includes UBI initialization and building of UBI devices.
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".
19 #include <linux/err.h>
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <linux/stringify.h>
23 #include <linux/namei.h>
24 #include <linux/stat.h>
25 #include <linux/miscdevice.h>
26 #include <linux/mtd/partitions.h>
27 #include <linux/log2.h>
28 #include <linux/kthread.h>
29 #include <linux/kernel.h>
30 #include <linux/slab.h>
31 #include <linux/major.h>
34 /* Maximum length of the 'mtd=' parameter */
35 #define MTD_PARAM_LEN_MAX 64
37 /* Maximum number of comma-separated items in the 'mtd=' parameter */
38 #define MTD_PARAM_MAX_COUNT 6
40 /* Maximum value for the number of bad PEBs per 1024 PEBs */
41 #define MAX_MTD_UBI_BEB_LIMIT 768
43 #ifdef CONFIG_MTD_UBI_MODULE
44 #define ubi_is_module() 1
46 #define ubi_is_module() 0
50 * struct mtd_dev_param - MTD device parameter description data structure.
51 * @name: MTD character device node path, MTD device name, or MTD device number
53 * @ubi_num: UBI number
54 * @vid_hdr_offs: VID header offset
55 * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
56 * @enable_fm: enable fastmap when value is non-zero
57 * @need_resv_pool: reserve pool->max_size pebs when value is none-zero
59 struct mtd_dev_param {
60 char name[MTD_PARAM_LEN_MAX];
68 /* Numbers of elements set in the @mtd_dev_param array */
71 /* MTD devices specification parameters */
72 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
73 #ifdef CONFIG_MTD_UBI_FASTMAP
74 /* UBI module parameter to enable fastmap automatically on non-fastmap images */
75 static bool fm_autoconvert;
79 /* Slab cache for wear-leveling entries */
80 struct kmem_cache *ubi_wl_entry_slab;
82 /* UBI control character device */
83 static struct miscdevice ubi_ctrl_cdev = {
84 .minor = MISC_DYNAMIC_MINOR,
86 .fops = &ubi_ctrl_cdev_operations,
89 /* All UBI devices in system */
90 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
92 /* Serializes UBI devices creations and removals */
93 DEFINE_MUTEX(ubi_devices_mutex);
95 /* Protects @ubi_devices and @ubi->ref_count */
96 static DEFINE_SPINLOCK(ubi_devices_lock);
98 /* "Show" method for files in '/<sysfs>/class/ubi/' */
99 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
100 static ssize_t version_show(const struct class *class, const struct class_attribute *attr,
103 return sprintf(buf, "%d\n", UBI_VERSION);
105 static CLASS_ATTR_RO(version);
107 static struct attribute *ubi_class_attrs[] = {
108 &class_attr_version.attr,
111 ATTRIBUTE_GROUPS(ubi_class);
113 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
114 struct class ubi_class = {
115 .name = UBI_NAME_STR,
116 .class_groups = ubi_class_groups,
119 static ssize_t dev_attribute_show(struct device *dev,
120 struct device_attribute *attr, char *buf);
122 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
123 static struct device_attribute dev_eraseblock_size =
124 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
125 static struct device_attribute dev_avail_eraseblocks =
126 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
127 static struct device_attribute dev_total_eraseblocks =
128 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
129 static struct device_attribute dev_volumes_count =
130 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
131 static struct device_attribute dev_max_ec =
132 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
133 static struct device_attribute dev_reserved_for_bad =
134 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
135 static struct device_attribute dev_bad_peb_count =
136 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
137 static struct device_attribute dev_max_vol_count =
138 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
139 static struct device_attribute dev_min_io_size =
140 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
141 static struct device_attribute dev_bgt_enabled =
142 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
143 static struct device_attribute dev_mtd_num =
144 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
145 static struct device_attribute dev_ro_mode =
146 __ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
149 * ubi_volume_notify - send a volume change notification.
150 * @ubi: UBI device description object
151 * @vol: volume description object of the changed volume
152 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
154 * This is a helper function which notifies all subscribers about a volume
155 * change event (creation, removal, re-sizing, re-naming, updating). Returns
156 * zero in case of success and a negative error code in case of failure.
158 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
161 struct ubi_notification nt;
163 ubi_do_get_device_info(ubi, &nt.di);
164 ubi_do_get_volume_info(ubi, vol, &nt.vi);
167 case UBI_VOLUME_ADDED:
168 case UBI_VOLUME_REMOVED:
169 case UBI_VOLUME_RESIZED:
170 case UBI_VOLUME_RENAMED:
171 ret = ubi_update_fastmap(ubi);
173 ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
176 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
180 * ubi_notify_all - send a notification to all volumes.
181 * @ubi: UBI device description object
182 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
183 * @nb: the notifier to call
185 * This function walks all volumes of UBI device @ubi and sends the @ntype
186 * notification for each volume. If @nb is %NULL, then all registered notifiers
187 * are called, otherwise only the @nb notifier is called. Returns the number of
188 * sent notifications.
190 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
192 struct ubi_notification nt;
195 ubi_do_get_device_info(ubi, &nt.di);
197 mutex_lock(&ubi->device_mutex);
198 for (i = 0; i < ubi->vtbl_slots; i++) {
200 * Since the @ubi->device is locked, and we are not going to
201 * change @ubi->volumes, we do not have to lock
202 * @ubi->volumes_lock.
204 if (!ubi->volumes[i])
207 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
209 nb->notifier_call(nb, ntype, &nt);
211 blocking_notifier_call_chain(&ubi_notifiers, ntype,
215 mutex_unlock(&ubi->device_mutex);
221 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
222 * @nb: the notifier to call
224 * This function walks all UBI devices and volumes and sends the
225 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
226 * registered notifiers are called, otherwise only the @nb notifier is called.
227 * Returns the number of sent notifications.
229 int ubi_enumerate_volumes(struct notifier_block *nb)
234 * Since the @ubi_devices_mutex is locked, and we are not going to
235 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
237 for (i = 0; i < UBI_MAX_DEVICES; i++) {
238 struct ubi_device *ubi = ubi_devices[i];
242 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
249 * ubi_get_device - get UBI device.
250 * @ubi_num: UBI device number
252 * This function returns UBI device description object for UBI device number
253 * @ubi_num, or %NULL if the device does not exist. This function increases the
254 * device reference count to prevent removal of the device. In other words, the
255 * device cannot be removed if its reference count is not zero.
257 struct ubi_device *ubi_get_device(int ubi_num)
259 struct ubi_device *ubi;
261 spin_lock(&ubi_devices_lock);
262 ubi = ubi_devices[ubi_num];
264 ubi_assert(ubi->ref_count >= 0);
266 get_device(&ubi->dev);
268 spin_unlock(&ubi_devices_lock);
274 * ubi_put_device - drop an UBI device reference.
275 * @ubi: UBI device description object
277 void ubi_put_device(struct ubi_device *ubi)
279 spin_lock(&ubi_devices_lock);
281 put_device(&ubi->dev);
282 spin_unlock(&ubi_devices_lock);
286 * ubi_get_by_major - get UBI device by character device major number.
287 * @major: major number
289 * This function is similar to 'ubi_get_device()', but it searches the device
290 * by its major number.
292 struct ubi_device *ubi_get_by_major(int major)
295 struct ubi_device *ubi;
297 spin_lock(&ubi_devices_lock);
298 for (i = 0; i < UBI_MAX_DEVICES; i++) {
299 ubi = ubi_devices[i];
300 if (ubi && MAJOR(ubi->cdev.dev) == major) {
301 ubi_assert(ubi->ref_count >= 0);
303 get_device(&ubi->dev);
304 spin_unlock(&ubi_devices_lock);
308 spin_unlock(&ubi_devices_lock);
314 * ubi_major2num - get UBI device number by character device major number.
315 * @major: major number
317 * This function searches UBI device number object by its major number. If UBI
318 * device was not found, this function returns -ENODEV, otherwise the UBI device
319 * number is returned.
321 int ubi_major2num(int major)
323 int i, ubi_num = -ENODEV;
325 spin_lock(&ubi_devices_lock);
326 for (i = 0; i < UBI_MAX_DEVICES; i++) {
327 struct ubi_device *ubi = ubi_devices[i];
329 if (ubi && MAJOR(ubi->cdev.dev) == major) {
330 ubi_num = ubi->ubi_num;
334 spin_unlock(&ubi_devices_lock);
339 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
340 static ssize_t dev_attribute_show(struct device *dev,
341 struct device_attribute *attr, char *buf)
344 struct ubi_device *ubi;
347 * The below code looks weird, but it actually makes sense. We get the
348 * UBI device reference from the contained 'struct ubi_device'. But it
349 * is unclear if the device was removed or not yet. Indeed, if the
350 * device was removed before we increased its reference count,
351 * 'ubi_get_device()' will return -ENODEV and we fail.
353 * Remember, 'struct ubi_device' is freed in the release function, so
354 * we still can use 'ubi->ubi_num'.
356 ubi = container_of(dev, struct ubi_device, dev);
358 if (attr == &dev_eraseblock_size)
359 ret = sprintf(buf, "%d\n", ubi->leb_size);
360 else if (attr == &dev_avail_eraseblocks)
361 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
362 else if (attr == &dev_total_eraseblocks)
363 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
364 else if (attr == &dev_volumes_count)
365 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
366 else if (attr == &dev_max_ec)
367 ret = sprintf(buf, "%d\n", ubi->max_ec);
368 else if (attr == &dev_reserved_for_bad)
369 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
370 else if (attr == &dev_bad_peb_count)
371 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
372 else if (attr == &dev_max_vol_count)
373 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
374 else if (attr == &dev_min_io_size)
375 ret = sprintf(buf, "%d\n", ubi->min_io_size);
376 else if (attr == &dev_bgt_enabled)
377 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
378 else if (attr == &dev_mtd_num)
379 ret = sprintf(buf, "%d\n", ubi->mtd->index);
380 else if (attr == &dev_ro_mode)
381 ret = sprintf(buf, "%d\n", ubi->ro_mode);
388 static struct attribute *ubi_dev_attrs[] = {
389 &dev_eraseblock_size.attr,
390 &dev_avail_eraseblocks.attr,
391 &dev_total_eraseblocks.attr,
392 &dev_volumes_count.attr,
394 &dev_reserved_for_bad.attr,
395 &dev_bad_peb_count.attr,
396 &dev_max_vol_count.attr,
397 &dev_min_io_size.attr,
398 &dev_bgt_enabled.attr,
403 ATTRIBUTE_GROUPS(ubi_dev);
405 static void dev_release(struct device *dev)
407 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
413 * kill_volumes - destroy all user volumes.
414 * @ubi: UBI device description object
416 static void kill_volumes(struct ubi_device *ubi)
420 for (i = 0; i < ubi->vtbl_slots; i++)
422 ubi_free_volume(ubi, ubi->volumes[i]);
426 * uif_init - initialize user interfaces for an UBI device.
427 * @ubi: UBI device description object
429 * This function initializes various user interfaces for an UBI device. If the
430 * initialization fails at an early stage, this function frees all the
431 * resources it allocated, returns an error.
433 * This function returns zero in case of success and a negative error code in
436 static int uif_init(struct ubi_device *ubi)
441 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
444 * Major numbers for the UBI character devices are allocated
445 * dynamically. Major numbers of volume character devices are
446 * equivalent to ones of the corresponding UBI character device. Minor
447 * numbers of UBI character devices are 0, while minor numbers of
448 * volume character devices start from 1. Thus, we allocate one major
449 * number and ubi->vtbl_slots + 1 minor numbers.
451 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
453 ubi_err(ubi, "cannot register UBI character devices");
459 ubi_assert(MINOR(dev) == 0);
460 cdev_init(&ubi->cdev, &ubi_cdev_operations);
461 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
462 ubi->cdev.owner = THIS_MODULE;
464 dev_set_name(&ubi->dev, UBI_NAME_STR "%d", ubi->ubi_num);
465 err = cdev_device_add(&ubi->cdev, &ubi->dev);
469 for (i = 0; i < ubi->vtbl_slots; i++)
470 if (ubi->volumes[i]) {
471 err = ubi_add_volume(ubi, ubi->volumes[i]);
473 ubi_err(ubi, "cannot add volume %d", i);
474 ubi->volumes[i] = NULL;
483 cdev_device_del(&ubi->cdev, &ubi->dev);
485 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
486 ubi_err(ubi, "cannot initialize UBI %s, error %d",
492 * uif_close - close user interfaces for an UBI device.
493 * @ubi: UBI device description object
495 * Note, since this function un-registers UBI volume device objects (@vol->dev),
496 * the memory allocated voe the volumes is freed as well (in the release
499 static void uif_close(struct ubi_device *ubi)
502 cdev_device_del(&ubi->cdev, &ubi->dev);
503 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
507 * ubi_free_volumes_from - free volumes from specific index.
508 * @ubi: UBI device description object
509 * @from: the start index used for volume free.
511 static void ubi_free_volumes_from(struct ubi_device *ubi, int from)
515 for (i = from; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
516 if (!ubi->volumes[i])
518 ubi_eba_replace_table(ubi->volumes[i], NULL);
519 ubi_fastmap_destroy_checkmap(ubi->volumes[i]);
520 kfree(ubi->volumes[i]);
521 ubi->volumes[i] = NULL;
526 * ubi_free_all_volumes - free all volumes.
527 * @ubi: UBI device description object
529 void ubi_free_all_volumes(struct ubi_device *ubi)
531 ubi_free_volumes_from(ubi, 0);
535 * ubi_free_internal_volumes - free internal volumes.
536 * @ubi: UBI device description object
538 void ubi_free_internal_volumes(struct ubi_device *ubi)
540 ubi_free_volumes_from(ubi, ubi->vtbl_slots);
543 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
545 int limit, device_pebs;
546 uint64_t device_size;
548 if (!max_beb_per1024) {
550 * Since max_beb_per1024 has not been set by the user in either
551 * the cmdline or Kconfig, use mtd_max_bad_blocks to set the
552 * limit if it is supported by the device.
554 limit = mtd_max_bad_blocks(ubi->mtd, 0, ubi->mtd->size);
561 * Here we are using size of the entire flash chip and
562 * not just the MTD partition size because the maximum
563 * number of bad eraseblocks is a percentage of the
564 * whole device and bad eraseblocks are not fairly
565 * distributed over the flash chip. So the worst case
566 * is that all the bad eraseblocks of the chip are in
567 * the MTD partition we are attaching (ubi->mtd).
569 device_size = mtd_get_device_size(ubi->mtd);
570 device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
571 limit = mult_frac(device_pebs, max_beb_per1024, 1024);
574 if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
581 * io_init - initialize I/O sub-system for a given UBI device.
582 * @ubi: UBI device description object
583 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
585 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
587 * o EC header is always at offset zero - this cannot be changed;
588 * o VID header starts just after the EC header at the closest address
589 * aligned to @io->hdrs_min_io_size;
590 * o data starts just after the VID header at the closest address aligned to
593 * This function returns zero in case of success and a negative error code in
596 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
598 dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
599 dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
601 if (ubi->mtd->numeraseregions != 0) {
603 * Some flashes have several erase regions. Different regions
604 * may have different eraseblock size and other
605 * characteristics. It looks like mostly multi-region flashes
606 * have one "main" region and one or more small regions to
607 * store boot loader code or boot parameters or whatever. I
608 * guess we should just pick the largest region. But this is
611 ubi_err(ubi, "multiple regions, not implemented");
615 if (ubi->vid_hdr_offset < 0)
619 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
620 * physical eraseblocks maximum.
623 ubi->peb_size = ubi->mtd->erasesize;
624 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
625 ubi->flash_size = ubi->mtd->size;
627 if (mtd_can_have_bb(ubi->mtd)) {
628 ubi->bad_allowed = 1;
629 ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
632 if (ubi->mtd->type == MTD_NORFLASH)
635 ubi->min_io_size = ubi->mtd->writesize;
636 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
639 * Make sure minimal I/O unit is power of 2. Note, there is no
640 * fundamental reason for this assumption. It is just an optimization
641 * which allows us to avoid costly division operations.
643 if (!is_power_of_2(ubi->min_io_size)) {
644 ubi_err(ubi, "min. I/O unit (%d) is not power of 2",
649 ubi_assert(ubi->hdrs_min_io_size > 0);
650 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
651 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
653 ubi->max_write_size = ubi->mtd->writebufsize;
655 * Maximum write size has to be greater or equivalent to min. I/O
656 * size, and be multiple of min. I/O size.
658 if (ubi->max_write_size < ubi->min_io_size ||
659 ubi->max_write_size % ubi->min_io_size ||
660 !is_power_of_2(ubi->max_write_size)) {
661 ubi_err(ubi, "bad write buffer size %d for %d min. I/O unit",
662 ubi->max_write_size, ubi->min_io_size);
666 /* Calculate default aligned sizes of EC and VID headers */
667 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
668 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
670 dbg_gen("min_io_size %d", ubi->min_io_size);
671 dbg_gen("max_write_size %d", ubi->max_write_size);
672 dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
673 dbg_gen("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
674 dbg_gen("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
676 if (ubi->vid_hdr_offset == 0)
678 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
681 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
682 ~(ubi->hdrs_min_io_size - 1);
683 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
684 ubi->vid_hdr_aloffset;
688 * Memory allocation for VID header is ubi->vid_hdr_alsize
689 * which is described in comments in io.c.
690 * Make sure VID header shift + UBI_VID_HDR_SIZE not exceeds
691 * ubi->vid_hdr_alsize, so that all vid header operations
692 * won't access memory out of bounds.
694 if ((ubi->vid_hdr_shift + UBI_VID_HDR_SIZE) > ubi->vid_hdr_alsize) {
695 ubi_err(ubi, "Invalid VID header offset %d, VID header shift(%d)"
696 " + VID header size(%zu) > VID header aligned size(%d).",
697 ubi->vid_hdr_offset, ubi->vid_hdr_shift,
698 UBI_VID_HDR_SIZE, ubi->vid_hdr_alsize);
702 /* Similar for the data offset */
703 ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
704 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
706 dbg_gen("vid_hdr_offset %d", ubi->vid_hdr_offset);
707 dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
708 dbg_gen("vid_hdr_shift %d", ubi->vid_hdr_shift);
709 dbg_gen("leb_start %d", ubi->leb_start);
711 /* The shift must be aligned to 32-bit boundary */
712 if (ubi->vid_hdr_shift % 4) {
713 ubi_err(ubi, "unaligned VID header shift %d",
719 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
720 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
721 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
722 ubi->leb_start & (ubi->min_io_size - 1)) {
723 ubi_err(ubi, "bad VID header (%d) or data offsets (%d)",
724 ubi->vid_hdr_offset, ubi->leb_start);
729 * Set maximum amount of physical erroneous eraseblocks to be 10%.
730 * Erroneous PEB are those which have read errors.
732 ubi->max_erroneous = ubi->peb_count / 10;
733 if (ubi->max_erroneous < 16)
734 ubi->max_erroneous = 16;
735 dbg_gen("max_erroneous %d", ubi->max_erroneous);
738 * It may happen that EC and VID headers are situated in one minimal
739 * I/O unit. In this case we can only accept this UBI image in
742 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
743 ubi_warn(ubi, "EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
747 ubi->leb_size = ubi->peb_size - ubi->leb_start;
749 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
750 ubi_msg(ubi, "MTD device %d is write-protected, attach in read-only mode",
756 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
757 * unfortunately, MTD does not provide this information. We should loop
758 * over all physical eraseblocks and invoke mtd->block_is_bad() for
759 * each physical eraseblock. So, we leave @ubi->bad_peb_count
760 * uninitialized so far.
767 * autoresize - re-size the volume which has the "auto-resize" flag set.
768 * @ubi: UBI device description object
769 * @vol_id: ID of the volume to re-size
771 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
772 * the volume table to the largest possible size. See comments in ubi-header.h
773 * for more description of the flag. Returns zero in case of success and a
774 * negative error code in case of failure.
776 static int autoresize(struct ubi_device *ubi, int vol_id)
778 struct ubi_volume_desc desc;
779 struct ubi_volume *vol = ubi->volumes[vol_id];
780 int err, old_reserved_pebs = vol->reserved_pebs;
783 ubi_warn(ubi, "skip auto-resize because of R/O mode");
788 * Clear the auto-resize flag in the volume in-memory copy of the
789 * volume table, and 'ubi_resize_volume()' will propagate this change
792 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
794 if (ubi->avail_pebs == 0) {
795 struct ubi_vtbl_record vtbl_rec;
798 * No available PEBs to re-size the volume, clear the flag on
801 vtbl_rec = ubi->vtbl[vol_id];
802 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
804 ubi_err(ubi, "cannot clean auto-resize flag for volume %d",
808 err = ubi_resize_volume(&desc,
809 old_reserved_pebs + ubi->avail_pebs);
811 ubi_err(ubi, "cannot auto-resize volume %d",
818 ubi_msg(ubi, "volume %d (\"%s\") re-sized from %d to %d LEBs",
819 vol_id, vol->name, old_reserved_pebs, vol->reserved_pebs);
824 * ubi_attach_mtd_dev - attach an MTD device.
825 * @mtd: MTD device description object
826 * @ubi_num: number to assign to the new UBI device
827 * @vid_hdr_offset: VID header offset
828 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
829 * @disable_fm: whether disable fastmap
830 * @need_resv_pool: whether reserve pebs to fill fm_pool
832 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
833 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
834 * which case this function finds a vacant device number and assigns it
835 * automatically. Returns the new UBI device number in case of success and a
836 * negative error code in case of failure.
838 * If @disable_fm is true, ubi doesn't create new fastmap even the module param
839 * 'fm_autoconvert' is set, and existed old fastmap will be destroyed after
840 * doing full scanning.
842 * Note, the invocations of this function has to be serialized by the
843 * @ubi_devices_mutex.
845 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
846 int vid_hdr_offset, int max_beb_per1024, bool disable_fm,
849 struct ubi_device *ubi;
852 if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
855 if (!max_beb_per1024)
856 max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
859 * Check if we already have the same MTD device attached.
861 * Note, this function assumes that UBI devices creations and deletions
862 * are serialized, so it does not take the &ubi_devices_lock.
864 for (i = 0; i < UBI_MAX_DEVICES; i++) {
865 ubi = ubi_devices[i];
866 if (ubi && mtd->index == ubi->mtd->index) {
867 pr_err("ubi: mtd%d is already attached to ubi%d\n",
874 * Make sure this MTD device is not emulated on top of an UBI volume
875 * already. Well, generally this recursion works fine, but there are
876 * different problems like the UBI module takes a reference to itself
877 * by attaching (and thus, opening) the emulated MTD device. This
878 * results in inability to unload the module. And in general it makes
879 * no sense to attach emulated MTD devices, so we prohibit this.
881 if (mtd->type == MTD_UBIVOLUME) {
882 pr_err("ubi: refuse attaching mtd%d - it is already emulated on top of UBI\n",
888 * Both UBI and UBIFS have been designed for SLC NAND and NOR flashes.
889 * MLC NAND is different and needs special care, otherwise UBI or UBIFS
890 * will die soon and you will lose all your data.
891 * Relax this rule if the partition we're attaching to operates in SLC
894 if (mtd->type == MTD_MLCNANDFLASH &&
895 !(mtd->flags & MTD_SLC_ON_MLC_EMULATION)) {
896 pr_err("ubi: refuse attaching mtd%d - MLC NAND is not supported\n",
901 /* UBI cannot work on flashes with zero erasesize. */
902 if (!mtd->erasesize) {
903 pr_err("ubi: refuse attaching mtd%d - zero erasesize flash is not supported\n",
908 if (ubi_num == UBI_DEV_NUM_AUTO) {
909 /* Search for an empty slot in the @ubi_devices array */
910 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
911 if (!ubi_devices[ubi_num])
913 if (ubi_num == UBI_MAX_DEVICES) {
914 pr_err("ubi: only %d UBI devices may be created\n",
919 if (ubi_num >= UBI_MAX_DEVICES)
922 /* Make sure ubi_num is not busy */
923 if (ubi_devices[ubi_num]) {
924 pr_err("ubi: ubi%i already exists\n", ubi_num);
929 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
933 device_initialize(&ubi->dev);
934 ubi->dev.release = dev_release;
935 ubi->dev.class = &ubi_class;
936 ubi->dev.groups = ubi_dev_groups;
937 ubi->dev.parent = &mtd->dev;
940 ubi->ubi_num = ubi_num;
941 ubi->vid_hdr_offset = vid_hdr_offset;
942 ubi->autoresize_vol_id = -1;
944 #ifdef CONFIG_MTD_UBI_FASTMAP
945 ubi->fm_pool.used = ubi->fm_pool.size = 0;
946 ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
949 * fm_pool.max_size is 5% of the total number of PEBs but it's also
950 * between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
952 ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
953 ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
954 ubi->fm_pool.max_size = max(ubi->fm_pool.max_size,
955 UBI_FM_MIN_POOL_SIZE);
957 ubi->fm_wl_pool.max_size = ubi->fm_pool.max_size / 2;
958 ubi->fm_pool_rsv_cnt = need_resv_pool ? ubi->fm_pool.max_size : 0;
959 ubi->fm_disabled = (!fm_autoconvert || disable_fm) ? 1 : 0;
961 ubi_enable_dbg_chk_fastmap(ubi);
963 if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
964 <= UBI_FM_MAX_START) {
965 ubi_err(ubi, "More than %i PEBs are needed for fastmap, sorry.",
967 ubi->fm_disabled = 1;
970 ubi_msg(ubi, "default fastmap pool size: %d", ubi->fm_pool.max_size);
971 ubi_msg(ubi, "default fastmap WL pool size: %d",
972 ubi->fm_wl_pool.max_size);
974 ubi->fm_disabled = 1;
976 mutex_init(&ubi->buf_mutex);
977 mutex_init(&ubi->ckvol_mutex);
978 mutex_init(&ubi->device_mutex);
979 spin_lock_init(&ubi->volumes_lock);
980 init_rwsem(&ubi->fm_protect);
981 init_rwsem(&ubi->fm_eba_sem);
983 ubi_msg(ubi, "attaching mtd%d", mtd->index);
985 err = io_init(ubi, max_beb_per1024);
990 ubi->peb_buf = vmalloc(ubi->peb_size);
994 #ifdef CONFIG_MTD_UBI_FASTMAP
995 ubi->fm_size = ubi_calc_fm_size(ubi);
996 ubi->fm_buf = vzalloc(ubi->fm_size);
1000 err = ubi_attach(ubi, disable_fm ? 1 : 0);
1002 ubi_err(ubi, "failed to attach mtd%d, error %d",
1007 if (ubi->autoresize_vol_id != -1) {
1008 err = autoresize(ubi, ubi->autoresize_vol_id);
1013 err = uif_init(ubi);
1017 err = ubi_debugfs_init_dev(ubi);
1021 ubi->bgt_thread = kthread_create(ubi_thread, ubi, "%s", ubi->bgt_name);
1022 if (IS_ERR(ubi->bgt_thread)) {
1023 err = PTR_ERR(ubi->bgt_thread);
1024 ubi_err(ubi, "cannot spawn \"%s\", error %d",
1025 ubi->bgt_name, err);
1029 ubi_msg(ubi, "attached mtd%d (name \"%s\", size %llu MiB)",
1030 mtd->index, mtd->name, ubi->flash_size >> 20);
1031 ubi_msg(ubi, "PEB size: %d bytes (%d KiB), LEB size: %d bytes",
1032 ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
1033 ubi_msg(ubi, "min./max. I/O unit sizes: %d/%d, sub-page size %d",
1034 ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
1035 ubi_msg(ubi, "VID header offset: %d (aligned %d), data offset: %d",
1036 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
1037 ubi_msg(ubi, "good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
1038 ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
1039 ubi_msg(ubi, "user volume: %d, internal volumes: %d, max. volumes count: %d",
1040 ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
1042 ubi_msg(ubi, "max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
1043 ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
1045 ubi_msg(ubi, "available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
1046 ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
1049 * The below lock makes sure we do not race with 'ubi_thread()' which
1050 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1052 spin_lock(&ubi->wl_lock);
1053 ubi->thread_enabled = 1;
1054 wake_up_process(ubi->bgt_thread);
1055 spin_unlock(&ubi->wl_lock);
1057 ubi_devices[ubi_num] = ubi;
1058 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1062 ubi_debugfs_exit_dev(ubi);
1067 ubi_free_all_volumes(ubi);
1070 vfree(ubi->peb_buf);
1072 put_device(&ubi->dev);
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
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
1086 * Note, the invocations of this function has to be serialized by the
1087 * @ubi_devices_mutex.
1089 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1091 struct ubi_device *ubi;
1093 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1096 ubi = ubi_get_device(ubi_num);
1100 spin_lock(&ubi_devices_lock);
1101 put_device(&ubi->dev);
1102 ubi->ref_count -= 1;
1103 if (ubi->ref_count) {
1105 spin_unlock(&ubi_devices_lock);
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);
1112 ubi_devices[ubi_num] = NULL;
1113 spin_unlock(&ubi_devices_lock);
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);
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.
1130 if (ubi->bgt_thread)
1131 kthread_stop(ubi->bgt_thread);
1133 #ifdef CONFIG_MTD_UBI_FASTMAP
1134 cancel_work_sync(&ubi->fm_work);
1136 ubi_debugfs_exit_dev(ubi);
1140 ubi_free_internal_volumes(ubi);
1142 vfree(ubi->peb_buf);
1144 ubi_msg(ubi, "mtd%d is detached", ubi->mtd->index);
1145 put_mtd_device(ubi->mtd);
1146 put_device(&ubi->dev);
1151 * open_mtd_by_chdev - open an MTD device by its character device node path.
1152 * @mtd_dev: MTD character device node path
1154 * This helper function opens an MTD device by its character node device path.
1155 * Returns MTD device description object in case of success and a negative
1156 * error code in case of failure.
1158 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1164 /* Probably this is an MTD character device node path */
1165 err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1167 return ERR_PTR(err);
1169 err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
1172 return ERR_PTR(err);
1174 /* MTD device number is defined by the major / minor numbers */
1175 if (MAJOR(stat.rdev) != MTD_CHAR_MAJOR || !S_ISCHR(stat.mode))
1176 return ERR_PTR(-EINVAL);
1178 minor = MINOR(stat.rdev);
1182 * Just do not think the "/dev/mtdrX" devices support is need,
1183 * so do not support them to avoid doing extra work.
1185 return ERR_PTR(-EINVAL);
1187 return get_mtd_device(NULL, minor / 2);
1191 * open_mtd_device - open MTD device by name, character device path, or number.
1192 * @mtd_dev: name, character device node path, or MTD device device number
1194 * This function tries to open and MTD device described by @mtd_dev string,
1195 * which is first treated as ASCII MTD device number, and if it is not true, it
1196 * is treated as MTD device name, and if that is also not true, it is treated
1197 * as MTD character device node path. Returns MTD device description object in
1198 * case of success and a negative error code in case of failure.
1200 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1202 struct mtd_info *mtd;
1206 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1207 if (*endp != '\0' || mtd_dev == endp) {
1209 * This does not look like an ASCII integer, probably this is
1212 mtd = get_mtd_device_nm(mtd_dev);
1213 if (PTR_ERR(mtd) == -ENODEV)
1214 /* Probably this is an MTD character device node path */
1215 mtd = open_mtd_by_chdev(mtd_dev);
1217 mtd = get_mtd_device(NULL, mtd_num);
1222 static int __init ubi_init(void)
1226 /* Ensure that EC and VID headers have correct size */
1227 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1228 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1230 if (mtd_devs > UBI_MAX_DEVICES) {
1231 pr_err("UBI error: too many MTD devices, maximum is %d\n",
1236 /* Create base sysfs directory and sysfs files */
1237 err = class_register(&ubi_class);
1241 err = misc_register(&ubi_ctrl_cdev);
1243 pr_err("UBI error: cannot register device\n");
1247 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1248 sizeof(struct ubi_wl_entry),
1250 if (!ubi_wl_entry_slab) {
1255 err = ubi_debugfs_init();
1260 /* Attach MTD devices */
1261 for (i = 0; i < mtd_devs; i++) {
1262 struct mtd_dev_param *p = &mtd_dev_param[i];
1263 struct mtd_info *mtd;
1267 mtd = open_mtd_device(p->name);
1270 pr_err("UBI error: cannot open mtd %s, error %d\n",
1272 /* See comment below re-ubi_is_module(). */
1273 if (ubi_is_module())
1278 mutex_lock(&ubi_devices_mutex);
1279 err = ubi_attach_mtd_dev(mtd, p->ubi_num,
1280 p->vid_hdr_offs, p->max_beb_per1024,
1282 p->need_resv_pool != 0);
1283 mutex_unlock(&ubi_devices_mutex);
1285 pr_err("UBI error: cannot attach mtd%d\n",
1287 put_mtd_device(mtd);
1290 * Originally UBI stopped initializing on any error.
1291 * However, later on it was found out that this
1292 * behavior is not very good when UBI is compiled into
1293 * the kernel and the MTD devices to attach are passed
1294 * through the command line. Indeed, UBI failure
1295 * stopped whole boot sequence.
1297 * To fix this, we changed the behavior for the
1298 * non-module case, but preserved the old behavior for
1299 * the module case, just for compatibility. This is a
1300 * little inconsistent, though.
1302 if (ubi_is_module())
1307 err = ubiblock_init();
1309 pr_err("UBI error: block: cannot initialize, error %d\n", err);
1311 /* See comment above re-ubi_is_module(). */
1312 if (ubi_is_module())
1319 for (k = 0; k < i; k++)
1320 if (ubi_devices[k]) {
1321 mutex_lock(&ubi_devices_mutex);
1322 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1323 mutex_unlock(&ubi_devices_mutex);
1327 kmem_cache_destroy(ubi_wl_entry_slab);
1329 misc_deregister(&ubi_ctrl_cdev);
1331 class_unregister(&ubi_class);
1332 pr_err("UBI error: cannot initialize UBI, error %d\n", err);
1335 late_initcall(ubi_init);
1337 static void __exit ubi_exit(void)
1343 for (i = 0; i < UBI_MAX_DEVICES; i++)
1344 if (ubi_devices[i]) {
1345 mutex_lock(&ubi_devices_mutex);
1346 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1347 mutex_unlock(&ubi_devices_mutex);
1350 kmem_cache_destroy(ubi_wl_entry_slab);
1351 misc_deregister(&ubi_ctrl_cdev);
1352 class_unregister(&ubi_class);
1354 module_exit(ubi_exit);
1357 * bytes_str_to_int - convert a number of bytes string into an integer.
1358 * @str: the string to convert
1360 * This function returns positive resulting integer in case of success and a
1361 * negative error code in case of failure.
1363 static int bytes_str_to_int(const char *str)
1366 unsigned long result;
1368 result = simple_strtoul(str, &endp, 0);
1369 if (str == endp || result >= INT_MAX) {
1370 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1387 pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
1395 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1396 * @val: the parameter value to parse
1399 * This function returns zero in case of success and a negative error code in
1402 static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp)
1405 struct mtd_dev_param *p;
1406 char buf[MTD_PARAM_LEN_MAX];
1407 char *pbuf = &buf[0];
1408 char *tokens[MTD_PARAM_MAX_COUNT], *token;
1413 if (mtd_devs == UBI_MAX_DEVICES) {
1414 pr_err("UBI error: too many parameters, max. is %d\n",
1419 len = strnlen(val, MTD_PARAM_LEN_MAX);
1420 if (len == MTD_PARAM_LEN_MAX) {
1421 pr_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
1422 val, MTD_PARAM_LEN_MAX);
1427 pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
1433 /* Get rid of the final newline */
1434 if (buf[len - 1] == '\n')
1435 buf[len - 1] = '\0';
1437 for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1438 tokens[i] = strsep(&pbuf, ",");
1441 pr_err("UBI error: too many arguments at \"%s\"\n", val);
1445 p = &mtd_dev_param[mtd_devs];
1446 strcpy(&p->name[0], tokens[0]);
1450 p->vid_hdr_offs = bytes_str_to_int(token);
1452 if (p->vid_hdr_offs < 0)
1453 return p->vid_hdr_offs;
1458 int err = kstrtoint(token, 10, &p->max_beb_per1024);
1461 pr_err("UBI error: bad value for max_beb_per1024 parameter: %s\n",
1469 int err = kstrtoint(token, 10, &p->ubi_num);
1472 pr_err("UBI error: bad value for ubi_num parameter: %s\n",
1477 p->ubi_num = UBI_DEV_NUM_AUTO;
1481 int err = kstrtoint(token, 10, &p->enable_fm);
1484 pr_err("UBI error: bad value for enable_fm parameter: %s\n",
1493 int err = kstrtoint(token, 10, &p->need_resv_pool);
1496 pr_err("UBI error: bad value for need_resv_pool parameter: %s\n",
1501 p->need_resv_pool = 0;
1507 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 0400);
1508 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024[,ubi_num]]].\n"
1509 "Multiple \"mtd\" parameters may be specified.\n"
1510 "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1511 "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1512 "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1513 __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1514 "Optional \"ubi_num\" parameter specifies UBI device number which have to be assigned to the newly created UBI device (assigned automatically by default)\n"
1515 "Optional \"enable_fm\" parameter determines whether to enable fastmap during attach. If the value is non-zero, fastmap is enabled. Default value is 0.\n"
1516 "Optional \"need_resv_pool\" parameter determines whether to reserve pool->max_size pebs during attach. If the value is non-zero, peb reservation is enabled. Default value is 0.\n"
1518 "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1519 "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"
1520 "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"
1521 "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"
1522 "example 5: mtd=1,0,0,5 mtd=2,0,0,6,1 - attach MTD device /dev/mtd1 to UBI 5 and disable fastmap; attach MTD device /dev/mtd2 to UBI 6 and enable fastmap.(only works when fastmap is enabled and fm_autoconvert=Y).\n"
1523 "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1524 #ifdef CONFIG_MTD_UBI_FASTMAP
1525 module_param(fm_autoconvert, bool, 0644);
1526 MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
1527 module_param(fm_debug, bool, 0);
1528 MODULE_PARM_DESC(fm_debug, "Set this parameter to enable fastmap debugging by default. Warning, this will make fastmap slow!");
1530 MODULE_VERSION(__stringify(UBI_VERSION));
1531 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1532 MODULE_AUTHOR("Artem Bityutskiy");
1533 MODULE_LICENSE("GPL");