2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2007
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Author: Artem Bityutskiy (Битюцкий Артём),
24 * This file includes UBI initialization and building of UBI devices.
26 * When UBI is initialized, it attaches all the MTD devices specified as the
27 * module load parameters or the kernel boot parameters. If MTD devices were
28 * specified, UBI does not attach any MTD device, but it is possible to do
29 * later using the "UBI control device".
31 * At the moment we only attach UBI devices by scanning, which will become a
32 * bottleneck when flashes reach certain large size. Then one may improve UBI
33 * and add other methods, although it does not seem to be easy to do.
36 #include <linux/err.h>
37 #include <linux/module.h>
38 #include <linux/moduleparam.h>
39 #include <linux/stringify.h>
40 #include <linux/namei.h>
41 #include <linux/stat.h>
42 #include <linux/miscdevice.h>
43 #include <linux/log2.h>
44 #include <linux/kthread.h>
45 #include <linux/reboot.h>
46 #include <linux/kernel.h>
49 /* Maximum length of the 'mtd=' parameter */
50 #define MTD_PARAM_LEN_MAX 64
53 * struct mtd_dev_param - MTD device parameter description data structure.
54 * @name: MTD character device node path, MTD device name, or MTD device number
56 * @vid_hdr_offs: VID header offset
58 struct mtd_dev_param {
59 char name[MTD_PARAM_LEN_MAX];
63 /* Numbers of elements set in the @mtd_dev_param array */
64 static int __initdata mtd_devs;
66 /* MTD devices specification parameters */
67 static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
69 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
70 struct class *ubi_class;
72 /* Slab cache for wear-leveling entries */
73 struct kmem_cache *ubi_wl_entry_slab;
75 /* UBI control character device */
76 static struct miscdevice ubi_ctrl_cdev = {
77 .minor = MISC_DYNAMIC_MINOR,
79 .fops = &ubi_ctrl_cdev_operations,
82 /* All UBI devices in system */
83 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
85 /* Serializes UBI devices creations and removals */
86 DEFINE_MUTEX(ubi_devices_mutex);
88 /* Protects @ubi_devices and @ubi->ref_count */
89 static DEFINE_SPINLOCK(ubi_devices_lock);
91 /* "Show" method for files in '/<sysfs>/class/ubi/' */
92 static ssize_t ubi_version_show(struct class *class, struct class_attribute *attr,
95 return sprintf(buf, "%d\n", UBI_VERSION);
98 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
99 static struct class_attribute ubi_version =
100 __ATTR(version, S_IRUGO, ubi_version_show, NULL);
102 static ssize_t dev_attribute_show(struct device *dev,
103 struct device_attribute *attr, char *buf);
105 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
106 static struct device_attribute dev_eraseblock_size =
107 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
108 static struct device_attribute dev_avail_eraseblocks =
109 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
110 static struct device_attribute dev_total_eraseblocks =
111 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
112 static struct device_attribute dev_volumes_count =
113 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
114 static struct device_attribute dev_max_ec =
115 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
116 static struct device_attribute dev_reserved_for_bad =
117 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
118 static struct device_attribute dev_bad_peb_count =
119 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
120 static struct device_attribute dev_max_vol_count =
121 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
122 static struct device_attribute dev_min_io_size =
123 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
124 static struct device_attribute dev_bgt_enabled =
125 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
126 static struct device_attribute dev_mtd_num =
127 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
130 * ubi_volume_notify - send a volume change notification.
131 * @ubi: UBI device description object
132 * @vol: volume description object of the changed volume
133 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
135 * This is a helper function which notifies all subscribers about a volume
136 * change event (creation, removal, re-sizing, re-naming, updating). Returns
137 * zero in case of success and a negative error code in case of failure.
139 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
141 struct ubi_notification nt;
143 ubi_do_get_device_info(ubi, &nt.di);
144 ubi_do_get_volume_info(ubi, vol, &nt.vi);
145 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
149 * ubi_notify_all - send a notification to all volumes.
150 * @ubi: UBI device description object
151 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
152 * @nb: the notifier to call
154 * This function walks all volumes of UBI device @ubi and sends the @ntype
155 * notification for each volume. If @nb is %NULL, then all registered notifiers
156 * are called, otherwise only the @nb notifier is called. Returns the number of
157 * sent notifications.
159 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
161 struct ubi_notification nt;
164 ubi_do_get_device_info(ubi, &nt.di);
166 mutex_lock(&ubi->device_mutex);
167 for (i = 0; i < ubi->vtbl_slots; i++) {
169 * Since the @ubi->device is locked, and we are not going to
170 * change @ubi->volumes, we do not have to lock
171 * @ubi->volumes_lock.
173 if (!ubi->volumes[i])
176 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
178 nb->notifier_call(nb, ntype, &nt);
180 blocking_notifier_call_chain(&ubi_notifiers, ntype,
184 mutex_unlock(&ubi->device_mutex);
190 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
191 * @nb: the notifier to call
193 * This function walks all UBI devices and volumes and sends the
194 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
195 * registered notifiers are called, otherwise only the @nb notifier is called.
196 * Returns the number of sent notifications.
198 int ubi_enumerate_volumes(struct notifier_block *nb)
203 * Since the @ubi_devices_mutex is locked, and we are not going to
204 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
206 for (i = 0; i < UBI_MAX_DEVICES; i++) {
207 struct ubi_device *ubi = ubi_devices[i];
211 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
218 * ubi_get_device - get UBI device.
219 * @ubi_num: UBI device number
221 * This function returns UBI device description object for UBI device number
222 * @ubi_num, or %NULL if the device does not exist. This function increases the
223 * device reference count to prevent removal of the device. In other words, the
224 * device cannot be removed if its reference count is not zero.
226 struct ubi_device *ubi_get_device(int ubi_num)
228 struct ubi_device *ubi;
230 spin_lock(&ubi_devices_lock);
231 ubi = ubi_devices[ubi_num];
233 ubi_assert(ubi->ref_count >= 0);
235 get_device(&ubi->dev);
237 spin_unlock(&ubi_devices_lock);
243 * ubi_put_device - drop an UBI device reference.
244 * @ubi: UBI device description object
246 void ubi_put_device(struct ubi_device *ubi)
248 spin_lock(&ubi_devices_lock);
250 put_device(&ubi->dev);
251 spin_unlock(&ubi_devices_lock);
255 * ubi_get_by_major - get UBI device by character device major number.
256 * @major: major number
258 * This function is similar to 'ubi_get_device()', but it searches the device
259 * by its major number.
261 struct ubi_device *ubi_get_by_major(int major)
264 struct ubi_device *ubi;
266 spin_lock(&ubi_devices_lock);
267 for (i = 0; i < UBI_MAX_DEVICES; i++) {
268 ubi = ubi_devices[i];
269 if (ubi && MAJOR(ubi->cdev.dev) == major) {
270 ubi_assert(ubi->ref_count >= 0);
272 get_device(&ubi->dev);
273 spin_unlock(&ubi_devices_lock);
277 spin_unlock(&ubi_devices_lock);
283 * ubi_major2num - get UBI device number by character device major number.
284 * @major: major number
286 * This function searches UBI device number object by its major number. If UBI
287 * device was not found, this function returns -ENODEV, otherwise the UBI device
288 * number is returned.
290 int ubi_major2num(int major)
292 int i, ubi_num = -ENODEV;
294 spin_lock(&ubi_devices_lock);
295 for (i = 0; i < UBI_MAX_DEVICES; i++) {
296 struct ubi_device *ubi = ubi_devices[i];
298 if (ubi && MAJOR(ubi->cdev.dev) == major) {
299 ubi_num = ubi->ubi_num;
303 spin_unlock(&ubi_devices_lock);
308 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
309 static ssize_t dev_attribute_show(struct device *dev,
310 struct device_attribute *attr, char *buf)
313 struct ubi_device *ubi;
316 * The below code looks weird, but it actually makes sense. We get the
317 * UBI device reference from the contained 'struct ubi_device'. But it
318 * is unclear if the device was removed or not yet. Indeed, if the
319 * device was removed before we increased its reference count,
320 * 'ubi_get_device()' will return -ENODEV and we fail.
322 * Remember, 'struct ubi_device' is freed in the release function, so
323 * we still can use 'ubi->ubi_num'.
325 ubi = container_of(dev, struct ubi_device, dev);
326 ubi = ubi_get_device(ubi->ubi_num);
330 if (attr == &dev_eraseblock_size)
331 ret = sprintf(buf, "%d\n", ubi->leb_size);
332 else if (attr == &dev_avail_eraseblocks)
333 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
334 else if (attr == &dev_total_eraseblocks)
335 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
336 else if (attr == &dev_volumes_count)
337 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
338 else if (attr == &dev_max_ec)
339 ret = sprintf(buf, "%d\n", ubi->max_ec);
340 else if (attr == &dev_reserved_for_bad)
341 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
342 else if (attr == &dev_bad_peb_count)
343 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
344 else if (attr == &dev_max_vol_count)
345 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
346 else if (attr == &dev_min_io_size)
347 ret = sprintf(buf, "%d\n", ubi->min_io_size);
348 else if (attr == &dev_bgt_enabled)
349 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
350 else if (attr == &dev_mtd_num)
351 ret = sprintf(buf, "%d\n", ubi->mtd->index);
359 static void dev_release(struct device *dev)
361 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
367 * ubi_sysfs_init - initialize sysfs for an UBI device.
368 * @ubi: UBI device description object
369 * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
372 * This function returns zero in case of success and a negative error code in
375 static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
379 ubi->dev.release = dev_release;
380 ubi->dev.devt = ubi->cdev.dev;
381 ubi->dev.class = ubi_class;
382 dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
383 err = device_register(&ubi->dev);
388 err = device_create_file(&ubi->dev, &dev_eraseblock_size);
391 err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
394 err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
397 err = device_create_file(&ubi->dev, &dev_volumes_count);
400 err = device_create_file(&ubi->dev, &dev_max_ec);
403 err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
406 err = device_create_file(&ubi->dev, &dev_bad_peb_count);
409 err = device_create_file(&ubi->dev, &dev_max_vol_count);
412 err = device_create_file(&ubi->dev, &dev_min_io_size);
415 err = device_create_file(&ubi->dev, &dev_bgt_enabled);
418 err = device_create_file(&ubi->dev, &dev_mtd_num);
423 * ubi_sysfs_close - close sysfs for an UBI device.
424 * @ubi: UBI device description object
426 static void ubi_sysfs_close(struct ubi_device *ubi)
428 device_remove_file(&ubi->dev, &dev_mtd_num);
429 device_remove_file(&ubi->dev, &dev_bgt_enabled);
430 device_remove_file(&ubi->dev, &dev_min_io_size);
431 device_remove_file(&ubi->dev, &dev_max_vol_count);
432 device_remove_file(&ubi->dev, &dev_bad_peb_count);
433 device_remove_file(&ubi->dev, &dev_reserved_for_bad);
434 device_remove_file(&ubi->dev, &dev_max_ec);
435 device_remove_file(&ubi->dev, &dev_volumes_count);
436 device_remove_file(&ubi->dev, &dev_total_eraseblocks);
437 device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
438 device_remove_file(&ubi->dev, &dev_eraseblock_size);
439 device_unregister(&ubi->dev);
443 * kill_volumes - destroy all user volumes.
444 * @ubi: UBI device description object
446 static void kill_volumes(struct ubi_device *ubi)
450 for (i = 0; i < ubi->vtbl_slots; i++)
452 ubi_free_volume(ubi, ubi->volumes[i]);
456 * uif_init - initialize user interfaces for an UBI device.
457 * @ubi: UBI device description object
458 * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
459 * taken, otherwise set to %0
461 * This function initializes various user interfaces for an UBI device. If the
462 * initialization fails at an early stage, this function frees all the
463 * resources it allocated, returns an error, and @ref is set to %0. However,
464 * if the initialization fails after the UBI device was registered in the
465 * driver core subsystem, this function takes a reference to @ubi->dev, because
466 * otherwise the release function ('dev_release()') would free whole @ubi
467 * object. The @ref argument is set to %1 in this case. The caller has to put
470 * This function returns zero in case of success and a negative error code in
473 static int uif_init(struct ubi_device *ubi, int *ref)
479 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
482 * Major numbers for the UBI character devices are allocated
483 * dynamically. Major numbers of volume character devices are
484 * equivalent to ones of the corresponding UBI character device. Minor
485 * numbers of UBI character devices are 0, while minor numbers of
486 * volume character devices start from 1. Thus, we allocate one major
487 * number and ubi->vtbl_slots + 1 minor numbers.
489 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
491 ubi_err("cannot register UBI character devices");
495 ubi_assert(MINOR(dev) == 0);
496 cdev_init(&ubi->cdev, &ubi_cdev_operations);
497 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
498 ubi->cdev.owner = THIS_MODULE;
500 err = cdev_add(&ubi->cdev, dev, 1);
502 ubi_err("cannot add character device");
506 err = ubi_sysfs_init(ubi, ref);
510 for (i = 0; i < ubi->vtbl_slots; i++)
511 if (ubi->volumes[i]) {
512 err = ubi_add_volume(ubi, ubi->volumes[i]);
514 ubi_err("cannot add volume %d", i);
525 get_device(&ubi->dev);
526 ubi_sysfs_close(ubi);
527 cdev_del(&ubi->cdev);
529 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
530 ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
535 * uif_close - close user interfaces for an UBI device.
536 * @ubi: UBI device description object
538 * Note, since this function un-registers UBI volume device objects (@vol->dev),
539 * the memory allocated voe the volumes is freed as well (in the release
542 static void uif_close(struct ubi_device *ubi)
545 ubi_sysfs_close(ubi);
546 cdev_del(&ubi->cdev);
547 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
551 * free_internal_volumes - free internal volumes.
552 * @ubi: UBI device description object
554 static void free_internal_volumes(struct ubi_device *ubi)
558 for (i = ubi->vtbl_slots;
559 i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
560 kfree(ubi->volumes[i]->eba_tbl);
561 kfree(ubi->volumes[i]);
566 * attach_by_scanning - attach an MTD device using scanning method.
567 * @ubi: UBI device descriptor
569 * This function returns zero in case of success and a negative error code in
572 * Note, currently this is the only method to attach UBI devices. Hopefully in
573 * the future we'll have more scalable attaching methods and avoid full media
574 * scanning. But even in this case scanning will be needed as a fall-back
575 * attaching method if there are some on-flash table corruptions.
577 static int attach_by_scanning(struct ubi_device *ubi)
580 struct ubi_scan_info *si;
586 ubi->bad_peb_count = si->bad_peb_count;
587 ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
588 ubi->max_ec = si->max_ec;
589 ubi->mean_ec = si->mean_ec;
591 err = ubi_read_volume_table(ubi, si);
595 err = ubi_wl_init_scan(ubi, si);
599 err = ubi_eba_init_scan(ubi, si);
603 ubi_scan_destroy_si(si);
609 free_internal_volumes(ubi);
612 ubi_scan_destroy_si(si);
617 * io_init - initialize I/O sub-system for a given UBI device.
618 * @ubi: UBI device description object
620 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
622 * o EC header is always at offset zero - this cannot be changed;
623 * o VID header starts just after the EC header at the closest address
624 * aligned to @io->hdrs_min_io_size;
625 * o data starts just after the VID header at the closest address aligned to
628 * This function returns zero in case of success and a negative error code in
631 static int io_init(struct ubi_device *ubi)
633 if (ubi->mtd->numeraseregions != 0) {
635 * Some flashes have several erase regions. Different regions
636 * may have different eraseblock size and other
637 * characteristics. It looks like mostly multi-region flashes
638 * have one "main" region and one or more small regions to
639 * store boot loader code or boot parameters or whatever. I
640 * guess we should just pick the largest region. But this is
643 ubi_err("multiple regions, not implemented");
647 if (ubi->vid_hdr_offset < 0)
651 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
652 * physical eraseblocks maximum.
655 ubi->peb_size = ubi->mtd->erasesize;
656 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
657 ubi->flash_size = ubi->mtd->size;
659 if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
660 ubi->bad_allowed = 1;
662 if (ubi->mtd->type == MTD_NORFLASH) {
663 ubi_assert(ubi->mtd->writesize == 1);
667 ubi->min_io_size = ubi->mtd->writesize;
668 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
671 * Make sure minimal I/O unit is power of 2. Note, there is no
672 * fundamental reason for this assumption. It is just an optimization
673 * which allows us to avoid costly division operations.
675 if (!is_power_of_2(ubi->min_io_size)) {
676 ubi_err("min. I/O unit (%d) is not power of 2",
681 ubi_assert(ubi->hdrs_min_io_size > 0);
682 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
683 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
685 /* Calculate default aligned sizes of EC and VID headers */
686 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
687 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
689 dbg_msg("min_io_size %d", ubi->min_io_size);
690 dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
691 dbg_msg("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
692 dbg_msg("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
694 if (ubi->vid_hdr_offset == 0)
696 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
699 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
700 ~(ubi->hdrs_min_io_size - 1);
701 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
702 ubi->vid_hdr_aloffset;
705 /* Similar for the data offset */
706 ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
707 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
709 dbg_msg("vid_hdr_offset %d", ubi->vid_hdr_offset);
710 dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
711 dbg_msg("vid_hdr_shift %d", ubi->vid_hdr_shift);
712 dbg_msg("leb_start %d", ubi->leb_start);
714 /* The shift must be aligned to 32-bit boundary */
715 if (ubi->vid_hdr_shift % 4) {
716 ubi_err("unaligned VID header shift %d",
722 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
723 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
724 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
725 ubi->leb_start & (ubi->min_io_size - 1)) {
726 ubi_err("bad VID header (%d) or data offsets (%d)",
727 ubi->vid_hdr_offset, ubi->leb_start);
732 * Set maximum amount of physical erroneous eraseblocks to be 10%.
733 * Erroneous PEB are those which have read errors.
735 ubi->max_erroneous = ubi->peb_count / 10;
736 if (ubi->max_erroneous < 16)
737 ubi->max_erroneous = 16;
738 dbg_msg("max_erroneous %d", ubi->max_erroneous);
741 * It may happen that EC and VID headers are situated in one minimal
742 * I/O unit. In this case we can only accept this UBI image in
745 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
746 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
747 "switch to read-only mode");
751 ubi->leb_size = ubi->peb_size - ubi->leb_start;
753 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
754 ubi_msg("MTD device %d is write-protected, attach in "
755 "read-only mode", ubi->mtd->index);
759 ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
760 ubi->peb_size, ubi->peb_size >> 10);
761 ubi_msg("logical eraseblock size: %d bytes", ubi->leb_size);
762 ubi_msg("smallest flash I/O unit: %d", ubi->min_io_size);
763 if (ubi->hdrs_min_io_size != ubi->min_io_size)
764 ubi_msg("sub-page size: %d",
765 ubi->hdrs_min_io_size);
766 ubi_msg("VID header offset: %d (aligned %d)",
767 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
768 ubi_msg("data offset: %d", ubi->leb_start);
771 * Note, ideally, we have to initialize ubi->bad_peb_count here. But
772 * unfortunately, MTD does not provide this information. We should loop
773 * over all physical eraseblocks and invoke mtd->block_is_bad() for
774 * each physical eraseblock. So, we skip ubi->bad_peb_count
775 * uninitialized and initialize it after scanning.
782 * autoresize - re-size the volume which has the "auto-resize" flag set.
783 * @ubi: UBI device description object
784 * @vol_id: ID of the volume to re-size
786 * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
787 * the volume table to the largest possible size. See comments in ubi-header.h
788 * for more description of the flag. Returns zero in case of success and a
789 * negative error code in case of failure.
791 static int autoresize(struct ubi_device *ubi, int vol_id)
793 struct ubi_volume_desc desc;
794 struct ubi_volume *vol = ubi->volumes[vol_id];
795 int err, old_reserved_pebs = vol->reserved_pebs;
798 * Clear the auto-resize flag in the volume in-memory copy of the
799 * volume table, and 'ubi_resize_volume()' will propagate this change
802 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
804 if (ubi->avail_pebs == 0) {
805 struct ubi_vtbl_record vtbl_rec;
808 * No available PEBs to re-size the volume, clear the flag on
811 memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
812 sizeof(struct ubi_vtbl_record));
813 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
815 ubi_err("cannot clean auto-resize flag for volume %d",
819 err = ubi_resize_volume(&desc,
820 old_reserved_pebs + ubi->avail_pebs);
822 ubi_err("cannot auto-resize volume %d", vol_id);
828 ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
829 vol->name, old_reserved_pebs, vol->reserved_pebs);
834 * ubi_reboot_notifier - halt UBI transactions immediately prior to a reboot.
835 * @n: reboot notifier object
836 * @state: SYS_RESTART, SYS_HALT, or SYS_POWER_OFF
837 * @cmd: pointer to command string for RESTART2
839 * This function stops the UBI background thread so that the flash device
840 * remains quiescent when Linux restarts the system. Any queued work will be
841 * discarded, but this function will block until do_work() finishes if an
842 * operation is already in progress.
844 * This function solves a real-life problem observed on NOR flashes when an
845 * PEB erase operation starts, then the system is rebooted before the erase is
846 * finishes, and the boot loader gets confused and dies. So we prefer to finish
847 * the ongoing operation before rebooting.
849 static int ubi_reboot_notifier(struct notifier_block *n, unsigned long state,
852 struct ubi_device *ubi;
854 ubi = container_of(n, struct ubi_device, reboot_notifier);
856 kthread_stop(ubi->bgt_thread);
857 ubi_sync(ubi->ubi_num);
862 * ubi_attach_mtd_dev - attach an MTD device.
863 * @mtd: MTD device description object
864 * @ubi_num: number to assign to the new UBI device
865 * @vid_hdr_offset: VID header offset
867 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
868 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
869 * which case this function finds a vacant device number and assigns it
870 * automatically. Returns the new UBI device number in case of success and a
871 * negative error code in case of failure.
873 * Note, the invocations of this function has to be serialized by the
874 * @ubi_devices_mutex.
876 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
878 struct ubi_device *ubi;
882 * Check if we already have the same MTD device attached.
884 * Note, this function assumes that UBI devices creations and deletions
885 * are serialized, so it does not take the &ubi_devices_lock.
887 for (i = 0; i < UBI_MAX_DEVICES; i++) {
888 ubi = ubi_devices[i];
889 if (ubi && mtd->index == ubi->mtd->index) {
890 dbg_err("mtd%d is already attached to ubi%d",
897 * Make sure this MTD device is not emulated on top of an UBI volume
898 * already. Well, generally this recursion works fine, but there are
899 * different problems like the UBI module takes a reference to itself
900 * by attaching (and thus, opening) the emulated MTD device. This
901 * results in inability to unload the module. And in general it makes
902 * no sense to attach emulated MTD devices, so we prohibit this.
904 if (mtd->type == MTD_UBIVOLUME) {
905 ubi_err("refuse attaching mtd%d - it is already emulated on "
906 "top of UBI", mtd->index);
910 if (ubi_num == UBI_DEV_NUM_AUTO) {
911 /* Search for an empty slot in the @ubi_devices array */
912 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
913 if (!ubi_devices[ubi_num])
915 if (ubi_num == UBI_MAX_DEVICES) {
916 dbg_err("only %d UBI devices may be created",
921 if (ubi_num >= UBI_MAX_DEVICES)
924 /* Make sure ubi_num is not busy */
925 if (ubi_devices[ubi_num]) {
926 dbg_err("ubi%d already exists", ubi_num);
931 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
936 ubi->ubi_num = ubi_num;
937 ubi->vid_hdr_offset = vid_hdr_offset;
938 ubi->autoresize_vol_id = -1;
940 mutex_init(&ubi->buf_mutex);
941 mutex_init(&ubi->ckvol_mutex);
942 mutex_init(&ubi->device_mutex);
943 spin_lock_init(&ubi->volumes_lock);
945 ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
952 ubi->peb_buf1 = vmalloc(ubi->peb_size);
956 ubi->peb_buf2 = vmalloc(ubi->peb_size);
960 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
961 mutex_init(&ubi->dbg_buf_mutex);
962 ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
963 if (!ubi->dbg_peb_buf)
967 err = attach_by_scanning(ubi);
969 dbg_err("failed to attach by scanning, error %d", err);
973 if (ubi->autoresize_vol_id != -1) {
974 err = autoresize(ubi, ubi->autoresize_vol_id);
979 err = uif_init(ubi, &ref);
983 ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
984 if (IS_ERR(ubi->bgt_thread)) {
985 err = PTR_ERR(ubi->bgt_thread);
986 ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
991 ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
992 ubi_msg("MTD device name: \"%s\"", mtd->name);
993 ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20);
994 ubi_msg("number of good PEBs: %d", ubi->good_peb_count);
995 ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count);
996 ubi_msg("max. allowed volumes: %d", ubi->vtbl_slots);
997 ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD);
998 ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
999 ubi_msg("number of user volumes: %d",
1000 ubi->vol_count - UBI_INT_VOL_COUNT);
1001 ubi_msg("available PEBs: %d", ubi->avail_pebs);
1002 ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
1003 ubi_msg("number of PEBs reserved for bad PEB handling: %d",
1004 ubi->beb_rsvd_pebs);
1005 ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
1006 ubi_msg("image sequence number: %d", ubi->image_seq);
1009 * The below lock makes sure we do not race with 'ubi_thread()' which
1010 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1012 spin_lock(&ubi->wl_lock);
1013 if (!DBG_DISABLE_BGT)
1014 ubi->thread_enabled = 1;
1015 wake_up_process(ubi->bgt_thread);
1016 spin_unlock(&ubi->wl_lock);
1018 /* Flash device priority is 0 - UBI needs to shut down first */
1019 ubi->reboot_notifier.priority = 1;
1020 ubi->reboot_notifier.notifier_call = ubi_reboot_notifier;
1021 register_reboot_notifier(&ubi->reboot_notifier);
1023 ubi_devices[ubi_num] = ubi;
1024 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1031 free_internal_volumes(ubi);
1034 vfree(ubi->peb_buf1);
1035 vfree(ubi->peb_buf2);
1036 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1037 vfree(ubi->dbg_peb_buf);
1040 put_device(&ubi->dev);
1047 * ubi_detach_mtd_dev - detach an MTD device.
1048 * @ubi_num: UBI device number to detach from
1049 * @anyway: detach MTD even if device reference count is not zero
1051 * This function destroys an UBI device number @ubi_num and detaches the
1052 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1053 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1056 * Note, the invocations of this function has to be serialized by the
1057 * @ubi_devices_mutex.
1059 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1061 struct ubi_device *ubi;
1063 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1066 ubi = ubi_get_device(ubi_num);
1070 spin_lock(&ubi_devices_lock);
1071 put_device(&ubi->dev);
1072 ubi->ref_count -= 1;
1073 if (ubi->ref_count) {
1075 spin_unlock(&ubi_devices_lock);
1078 /* This may only happen if there is a bug */
1079 ubi_err("%s reference count %d, destroy anyway",
1080 ubi->ubi_name, ubi->ref_count);
1082 ubi_devices[ubi_num] = NULL;
1083 spin_unlock(&ubi_devices_lock);
1085 ubi_assert(ubi_num == ubi->ubi_num);
1086 ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1087 dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
1090 * Before freeing anything, we have to stop the background thread to
1091 * prevent it from doing anything on this device while we are freeing.
1093 unregister_reboot_notifier(&ubi->reboot_notifier);
1094 if (ubi->bgt_thread)
1095 kthread_stop(ubi->bgt_thread);
1098 * Get a reference to the device in order to prevent 'dev_release()'
1099 * from freeing the @ubi object.
1101 get_device(&ubi->dev);
1105 free_internal_volumes(ubi);
1107 put_mtd_device(ubi->mtd);
1108 vfree(ubi->peb_buf1);
1109 vfree(ubi->peb_buf2);
1110 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1111 vfree(ubi->dbg_peb_buf);
1113 ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
1114 put_device(&ubi->dev);
1119 * open_mtd_by_chdev - open an MTD device by its character device node path.
1120 * @mtd_dev: MTD character device node path
1122 * This helper function opens an MTD device by its character node device path.
1123 * Returns MTD device description object in case of success and a negative
1124 * error code in case of failure.
1126 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1128 int err, major, minor, mode;
1131 /* Probably this is an MTD character device node path */
1132 err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1134 return ERR_PTR(err);
1136 /* MTD device number is defined by the major / minor numbers */
1137 major = imajor(path.dentry->d_inode);
1138 minor = iminor(path.dentry->d_inode);
1139 mode = path.dentry->d_inode->i_mode;
1141 if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))
1142 return ERR_PTR(-EINVAL);
1146 * Just do not think the "/dev/mtdrX" devices support is need,
1147 * so do not support them to avoid doing extra work.
1149 return ERR_PTR(-EINVAL);
1151 return get_mtd_device(NULL, minor / 2);
1155 * open_mtd_device - open MTD device by name, character device path, or number.
1156 * @mtd_dev: name, character device node path, or MTD device device number
1158 * This function tries to open and MTD device described by @mtd_dev string,
1159 * which is first treated as ASCII MTD device number, and if it is not true, it
1160 * is treated as MTD device name, and if that is also not true, it is treated
1161 * as MTD character device node path. Returns MTD device description object in
1162 * case of success and a negative error code in case of failure.
1164 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1166 struct mtd_info *mtd;
1170 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1171 if (*endp != '\0' || mtd_dev == endp) {
1173 * This does not look like an ASCII integer, probably this is
1176 mtd = get_mtd_device_nm(mtd_dev);
1177 if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV)
1178 /* Probably this is an MTD character device node path */
1179 mtd = open_mtd_by_chdev(mtd_dev);
1181 mtd = get_mtd_device(NULL, mtd_num);
1186 static int __init ubi_init(void)
1190 /* Ensure that EC and VID headers have correct size */
1191 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1192 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1194 if (mtd_devs > UBI_MAX_DEVICES) {
1195 ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
1199 /* Create base sysfs directory and sysfs files */
1200 ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
1201 if (IS_ERR(ubi_class)) {
1202 err = PTR_ERR(ubi_class);
1203 ubi_err("cannot create UBI class");
1207 err = class_create_file(ubi_class, &ubi_version);
1209 ubi_err("cannot create sysfs file");
1213 err = misc_register(&ubi_ctrl_cdev);
1215 ubi_err("cannot register device");
1219 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1220 sizeof(struct ubi_wl_entry),
1222 if (!ubi_wl_entry_slab)
1225 /* Attach MTD devices */
1226 for (i = 0; i < mtd_devs; i++) {
1227 struct mtd_dev_param *p = &mtd_dev_param[i];
1228 struct mtd_info *mtd;
1232 mtd = open_mtd_device(p->name);
1238 mutex_lock(&ubi_devices_mutex);
1239 err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
1241 mutex_unlock(&ubi_devices_mutex);
1243 put_mtd_device(mtd);
1244 ubi_err("cannot attach mtd%d", mtd->index);
1252 for (k = 0; k < i; k++)
1253 if (ubi_devices[k]) {
1254 mutex_lock(&ubi_devices_mutex);
1255 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1256 mutex_unlock(&ubi_devices_mutex);
1258 kmem_cache_destroy(ubi_wl_entry_slab);
1260 misc_deregister(&ubi_ctrl_cdev);
1262 class_remove_file(ubi_class, &ubi_version);
1264 class_destroy(ubi_class);
1266 ubi_err("UBI error: cannot initialize UBI, error %d", err);
1269 module_init(ubi_init);
1271 static void __exit ubi_exit(void)
1275 for (i = 0; i < UBI_MAX_DEVICES; i++)
1276 if (ubi_devices[i]) {
1277 mutex_lock(&ubi_devices_mutex);
1278 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1279 mutex_unlock(&ubi_devices_mutex);
1281 kmem_cache_destroy(ubi_wl_entry_slab);
1282 misc_deregister(&ubi_ctrl_cdev);
1283 class_remove_file(ubi_class, &ubi_version);
1284 class_destroy(ubi_class);
1286 module_exit(ubi_exit);
1289 * bytes_str_to_int - convert a number of bytes string into an integer.
1290 * @str: the string to convert
1292 * This function returns positive resulting integer in case of success and a
1293 * negative error code in case of failure.
1295 static int __init bytes_str_to_int(const char *str)
1298 unsigned long result;
1300 result = simple_strtoul(str, &endp, 0);
1301 if (str == endp || result >= INT_MAX) {
1302 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1314 if (endp[1] == 'i' && endp[2] == 'B')
1319 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1328 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1329 * @val: the parameter value to parse
1332 * This function returns zero in case of success and a negative error code in
1335 static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1338 struct mtd_dev_param *p;
1339 char buf[MTD_PARAM_LEN_MAX];
1340 char *pbuf = &buf[0];
1341 char *tokens[2] = {NULL, NULL};
1346 if (mtd_devs == UBI_MAX_DEVICES) {
1347 printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
1352 len = strnlen(val, MTD_PARAM_LEN_MAX);
1353 if (len == MTD_PARAM_LEN_MAX) {
1354 printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
1355 "max. is %d\n", val, MTD_PARAM_LEN_MAX);
1360 printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
1367 /* Get rid of the final newline */
1368 if (buf[len - 1] == '\n')
1369 buf[len - 1] = '\0';
1371 for (i = 0; i < 2; i++)
1372 tokens[i] = strsep(&pbuf, ",");
1375 printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
1380 p = &mtd_dev_param[mtd_devs];
1381 strcpy(&p->name[0], tokens[0]);
1384 p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
1386 if (p->vid_hdr_offs < 0)
1387 return p->vid_hdr_offs;
1393 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1394 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
1395 "mtd=<name|num|path>[,<vid_hdr_offs>].\n"
1396 "Multiple \"mtd\" parameters may be specified.\n"
1397 "MTD devices may be specified by their number, name, or "
1398 "path to the MTD character device node.\n"
1399 "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
1400 "header position to be used by UBI.\n"
1401 "Example 1: mtd=/dev/mtd0 - attach MTD device "
1403 "Example 2: mtd=content,1984 mtd=4 - attach MTD device "
1404 "with name \"content\" using VID header offset 1984, and "
1405 "MTD device number 4 with default VID header offset.");
1407 MODULE_VERSION(__stringify(UBI_VERSION));
1408 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1409 MODULE_AUTHOR("Artem Bityutskiy");
1410 MODULE_LICENSE("GPL");