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/stat.h>
41 #include <linux/miscdevice.h>
42 #include <linux/log2.h>
43 #include <linux/kthread.h>
46 /* Maximum length of the 'mtd=' parameter */
47 #define MTD_PARAM_LEN_MAX 64
50 * struct mtd_dev_param - MTD device parameter description data structure.
51 * @name: MTD device name or number string
52 * @vid_hdr_offs: VID header offset
54 struct mtd_dev_param {
55 char name[MTD_PARAM_LEN_MAX];
59 /* Numbers of elements set in the @mtd_dev_param array */
62 /* MTD devices specification parameters */
63 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
65 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
66 struct class *ubi_class;
68 /* Slab cache for wear-leveling entries */
69 struct kmem_cache *ubi_wl_entry_slab;
71 /* UBI control character device */
72 static struct miscdevice ubi_ctrl_cdev = {
73 .minor = MISC_DYNAMIC_MINOR,
75 .fops = &ubi_ctrl_cdev_operations,
78 /* All UBI devices in system */
79 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
81 /* Serializes UBI devices creations and removals */
82 DEFINE_MUTEX(ubi_devices_mutex);
84 /* Protects @ubi_devices and @ubi->ref_count */
85 static DEFINE_SPINLOCK(ubi_devices_lock);
87 /* "Show" method for files in '/<sysfs>/class/ubi/' */
88 static ssize_t ubi_version_show(struct class *class, char *buf)
90 return sprintf(buf, "%d\n", UBI_VERSION);
93 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
94 static struct class_attribute ubi_version =
95 __ATTR(version, S_IRUGO, ubi_version_show, NULL);
97 static ssize_t dev_attribute_show(struct device *dev,
98 struct device_attribute *attr, char *buf);
100 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
101 static struct device_attribute dev_eraseblock_size =
102 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
103 static struct device_attribute dev_avail_eraseblocks =
104 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
105 static struct device_attribute dev_total_eraseblocks =
106 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
107 static struct device_attribute dev_volumes_count =
108 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
109 static struct device_attribute dev_max_ec =
110 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
111 static struct device_attribute dev_reserved_for_bad =
112 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
113 static struct device_attribute dev_bad_peb_count =
114 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
115 static struct device_attribute dev_max_vol_count =
116 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
117 static struct device_attribute dev_min_io_size =
118 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
119 static struct device_attribute dev_bgt_enabled =
120 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
121 static struct device_attribute dev_mtd_num =
122 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
125 * ubi_get_device - get UBI device.
126 * @ubi_num: UBI device number
128 * This function returns UBI device description object for UBI device number
129 * @ubi_num, or %NULL if the device does not exist. This function increases the
130 * device reference count to prevent removal of the device. In other words, the
131 * device cannot be removed if its reference count is not zero.
133 struct ubi_device *ubi_get_device(int ubi_num)
135 struct ubi_device *ubi;
137 spin_lock(&ubi_devices_lock);
138 ubi = ubi_devices[ubi_num];
140 ubi_assert(ubi->ref_count >= 0);
142 get_device(&ubi->dev);
144 spin_unlock(&ubi_devices_lock);
150 * ubi_put_device - drop an UBI device reference.
151 * @ubi: UBI device description object
153 void ubi_put_device(struct ubi_device *ubi)
155 spin_lock(&ubi_devices_lock);
157 put_device(&ubi->dev);
158 spin_unlock(&ubi_devices_lock);
162 * ubi_get_by_major - get UBI device description object by character device
164 * @major: major number
166 * This function is similar to 'ubi_get_device()', but it searches the device
167 * by its major number.
169 struct ubi_device *ubi_get_by_major(int major)
172 struct ubi_device *ubi;
174 spin_lock(&ubi_devices_lock);
175 for (i = 0; i < UBI_MAX_DEVICES; i++) {
176 ubi = ubi_devices[i];
177 if (ubi && MAJOR(ubi->cdev.dev) == major) {
178 ubi_assert(ubi->ref_count >= 0);
180 get_device(&ubi->dev);
181 spin_unlock(&ubi_devices_lock);
185 spin_unlock(&ubi_devices_lock);
191 * ubi_major2num - get UBI device number by character device major number.
192 * @major: major number
194 * This function searches UBI device number object by its major number. If UBI
195 * device was not found, this function returns -ENODEV, otherwise the UBI device
196 * number is returned.
198 int ubi_major2num(int major)
200 int i, ubi_num = -ENODEV;
202 spin_lock(&ubi_devices_lock);
203 for (i = 0; i < UBI_MAX_DEVICES; i++) {
204 struct ubi_device *ubi = ubi_devices[i];
206 if (ubi && MAJOR(ubi->cdev.dev) == major) {
207 ubi_num = ubi->ubi_num;
211 spin_unlock(&ubi_devices_lock);
216 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
217 static ssize_t dev_attribute_show(struct device *dev,
218 struct device_attribute *attr, char *buf)
221 struct ubi_device *ubi;
224 * The below code looks weird, but it actually makes sense. We get the
225 * UBI device reference from the contained 'struct ubi_device'. But it
226 * is unclear if the device was removed or not yet. Indeed, if the
227 * device was removed before we increased its reference count,
228 * 'ubi_get_device()' will return -ENODEV and we fail.
230 * Remember, 'struct ubi_device' is freed in the release function, so
231 * we still can use 'ubi->ubi_num'.
233 ubi = container_of(dev, struct ubi_device, dev);
234 ubi = ubi_get_device(ubi->ubi_num);
238 if (attr == &dev_eraseblock_size)
239 ret = sprintf(buf, "%d\n", ubi->leb_size);
240 else if (attr == &dev_avail_eraseblocks)
241 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
242 else if (attr == &dev_total_eraseblocks)
243 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
244 else if (attr == &dev_volumes_count)
245 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
246 else if (attr == &dev_max_ec)
247 ret = sprintf(buf, "%d\n", ubi->max_ec);
248 else if (attr == &dev_reserved_for_bad)
249 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
250 else if (attr == &dev_bad_peb_count)
251 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
252 else if (attr == &dev_max_vol_count)
253 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
254 else if (attr == &dev_min_io_size)
255 ret = sprintf(buf, "%d\n", ubi->min_io_size);
256 else if (attr == &dev_bgt_enabled)
257 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
258 else if (attr == &dev_mtd_num)
259 ret = sprintf(buf, "%d\n", ubi->mtd->index);
267 /* Fake "release" method for UBI devices */
268 static void dev_release(struct device *dev) { }
271 * ubi_sysfs_init - initialize sysfs for an UBI device.
272 * @ubi: UBI device description object
274 * This function returns zero in case of success and a negative error code in
277 static int ubi_sysfs_init(struct ubi_device *ubi)
281 ubi->dev.release = dev_release;
282 ubi->dev.devt = ubi->cdev.dev;
283 ubi->dev.class = ubi_class;
284 sprintf(&ubi->dev.bus_id[0], UBI_NAME_STR"%d", ubi->ubi_num);
285 err = device_register(&ubi->dev);
289 err = device_create_file(&ubi->dev, &dev_eraseblock_size);
292 err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
295 err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
298 err = device_create_file(&ubi->dev, &dev_volumes_count);
301 err = device_create_file(&ubi->dev, &dev_max_ec);
304 err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
307 err = device_create_file(&ubi->dev, &dev_bad_peb_count);
310 err = device_create_file(&ubi->dev, &dev_max_vol_count);
313 err = device_create_file(&ubi->dev, &dev_min_io_size);
316 err = device_create_file(&ubi->dev, &dev_bgt_enabled);
319 err = device_create_file(&ubi->dev, &dev_mtd_num);
324 * ubi_sysfs_close - close sysfs for an UBI device.
325 * @ubi: UBI device description object
327 static void ubi_sysfs_close(struct ubi_device *ubi)
329 device_remove_file(&ubi->dev, &dev_mtd_num);
330 device_remove_file(&ubi->dev, &dev_bgt_enabled);
331 device_remove_file(&ubi->dev, &dev_min_io_size);
332 device_remove_file(&ubi->dev, &dev_max_vol_count);
333 device_remove_file(&ubi->dev, &dev_bad_peb_count);
334 device_remove_file(&ubi->dev, &dev_reserved_for_bad);
335 device_remove_file(&ubi->dev, &dev_max_ec);
336 device_remove_file(&ubi->dev, &dev_volumes_count);
337 device_remove_file(&ubi->dev, &dev_total_eraseblocks);
338 device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
339 device_remove_file(&ubi->dev, &dev_eraseblock_size);
340 device_unregister(&ubi->dev);
344 * kill_volumes - destroy all volumes.
345 * @ubi: UBI device description object
347 static void kill_volumes(struct ubi_device *ubi)
351 for (i = 0; i < ubi->vtbl_slots; i++)
353 ubi_free_volume(ubi, ubi->volumes[i]);
357 * free_user_volumes - free all user volumes.
358 * @ubi: UBI device description object
360 * Normally the volumes are freed at the release function of the volume device
361 * objects. However, on error paths the volumes have to be freed before the
362 * device objects have been initialized.
364 static void free_user_volumes(struct ubi_device *ubi)
368 for (i = 0; i < ubi->vtbl_slots; i++)
369 if (ubi->volumes[i]) {
370 kfree(ubi->volumes[i]->eba_tbl);
371 kfree(ubi->volumes[i]);
376 * uif_init - initialize user interfaces for an UBI device.
377 * @ubi: UBI device description object
379 * This function returns zero in case of success and a negative error code in
380 * case of failure. Note, this function destroys all volumes if it failes.
382 static int uif_init(struct ubi_device *ubi)
384 int i, err, do_free = 0;
387 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
390 * Major numbers for the UBI character devices are allocated
391 * dynamically. Major numbers of volume character devices are
392 * equivalent to ones of the corresponding UBI character device. Minor
393 * numbers of UBI character devices are 0, while minor numbers of
394 * volume character devices start from 1. Thus, we allocate one major
395 * number and ubi->vtbl_slots + 1 minor numbers.
397 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
399 ubi_err("cannot register UBI character devices");
403 ubi_assert(MINOR(dev) == 0);
404 cdev_init(&ubi->cdev, &ubi_cdev_operations);
405 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
406 ubi->cdev.owner = THIS_MODULE;
408 err = cdev_add(&ubi->cdev, dev, 1);
410 ubi_err("cannot add character device");
414 err = ubi_sysfs_init(ubi);
418 for (i = 0; i < ubi->vtbl_slots; i++)
419 if (ubi->volumes[i]) {
420 err = ubi_add_volume(ubi, ubi->volumes[i]);
422 ubi_err("cannot add volume %d", i);
433 ubi_sysfs_close(ubi);
434 cdev_del(&ubi->cdev);
437 free_user_volumes(ubi);
438 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
439 ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
444 * uif_close - close user interfaces for an UBI device.
445 * @ubi: UBI device description object
447 * Note, since this function un-registers UBI volume device objects (@vol->dev),
448 * the memory allocated voe the volumes is freed as well (in the release
451 static void uif_close(struct ubi_device *ubi)
454 ubi_sysfs_close(ubi);
455 cdev_del(&ubi->cdev);
456 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
460 * free_internal_volumes - free internal volumes.
461 * @ubi: UBI device description object
463 static void free_internal_volumes(struct ubi_device *ubi)
467 for (i = ubi->vtbl_slots;
468 i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
469 kfree(ubi->volumes[i]->eba_tbl);
470 kfree(ubi->volumes[i]);
475 * attach_by_scanning - attach an MTD device using scanning method.
476 * @ubi: UBI device descriptor
478 * This function returns zero in case of success and a negative error code in
481 * Note, currently this is the only method to attach UBI devices. Hopefully in
482 * the future we'll have more scalable attaching methods and avoid full media
483 * scanning. But even in this case scanning will be needed as a fall-back
484 * attaching method if there are some on-flash table corruptions.
486 static int attach_by_scanning(struct ubi_device *ubi)
489 struct ubi_scan_info *si;
495 ubi->bad_peb_count = si->bad_peb_count;
496 ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
497 ubi->max_ec = si->max_ec;
498 ubi->mean_ec = si->mean_ec;
500 err = ubi_read_volume_table(ubi, si);
504 err = ubi_wl_init_scan(ubi, si);
508 err = ubi_eba_init_scan(ubi, si);
512 ubi_scan_destroy_si(si);
518 free_internal_volumes(ubi);
521 ubi_scan_destroy_si(si);
526 * io_init - initialize I/O sub-system for a given UBI device.
527 * @ubi: UBI device description object
529 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
531 * o EC header is always at offset zero - this cannot be changed;
532 * o VID header starts just after the EC header at the closest address
533 * aligned to @io->hdrs_min_io_size;
534 * o data starts just after the VID header at the closest address aligned to
537 * This function returns zero in case of success and a negative error code in
540 static int io_init(struct ubi_device *ubi)
542 if (ubi->mtd->numeraseregions != 0) {
544 * Some flashes have several erase regions. Different regions
545 * may have different eraseblock size and other
546 * characteristics. It looks like mostly multi-region flashes
547 * have one "main" region and one or more small regions to
548 * store boot loader code or boot parameters or whatever. I
549 * guess we should just pick the largest region. But this is
552 ubi_err("multiple regions, not implemented");
556 if (ubi->vid_hdr_offset < 0)
560 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
561 * physical eraseblocks maximum.
564 ubi->peb_size = ubi->mtd->erasesize;
565 ubi->peb_count = ubi->mtd->size / ubi->mtd->erasesize;
566 ubi->flash_size = ubi->mtd->size;
568 if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
569 ubi->bad_allowed = 1;
571 ubi->min_io_size = ubi->mtd->writesize;
572 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
575 * Make sure minimal I/O unit is power of 2. Note, there is no
576 * fundamental reason for this assumption. It is just an optimization
577 * which allows us to avoid costly division operations.
579 if (!is_power_of_2(ubi->min_io_size)) {
580 ubi_err("min. I/O unit (%d) is not power of 2",
585 ubi_assert(ubi->hdrs_min_io_size > 0);
586 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
587 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
589 /* Calculate default aligned sizes of EC and VID headers */
590 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
591 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
593 dbg_msg("min_io_size %d", ubi->min_io_size);
594 dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
595 dbg_msg("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
596 dbg_msg("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
598 if (ubi->vid_hdr_offset == 0)
600 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
603 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
604 ~(ubi->hdrs_min_io_size - 1);
605 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
606 ubi->vid_hdr_aloffset;
609 /* Similar for the data offset */
610 ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
611 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
613 dbg_msg("vid_hdr_offset %d", ubi->vid_hdr_offset);
614 dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
615 dbg_msg("vid_hdr_shift %d", ubi->vid_hdr_shift);
616 dbg_msg("leb_start %d", ubi->leb_start);
618 /* The shift must be aligned to 32-bit boundary */
619 if (ubi->vid_hdr_shift % 4) {
620 ubi_err("unaligned VID header shift %d",
626 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
627 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
628 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
629 ubi->leb_start & (ubi->min_io_size - 1)) {
630 ubi_err("bad VID header (%d) or data offsets (%d)",
631 ubi->vid_hdr_offset, ubi->leb_start);
636 * It may happen that EC and VID headers are situated in one minimal
637 * I/O unit. In this case we can only accept this UBI image in
640 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
641 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
642 "switch to read-only mode");
646 ubi->leb_size = ubi->peb_size - ubi->leb_start;
648 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
649 ubi_msg("MTD device %d is write-protected, attach in "
650 "read-only mode", ubi->mtd->index);
654 ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
655 ubi->peb_size, ubi->peb_size >> 10);
656 ubi_msg("logical eraseblock size: %d bytes", ubi->leb_size);
657 ubi_msg("smallest flash I/O unit: %d", ubi->min_io_size);
658 if (ubi->hdrs_min_io_size != ubi->min_io_size)
659 ubi_msg("sub-page size: %d",
660 ubi->hdrs_min_io_size);
661 ubi_msg("VID header offset: %d (aligned %d)",
662 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
663 ubi_msg("data offset: %d", ubi->leb_start);
666 * Note, ideally, we have to initialize ubi->bad_peb_count here. But
667 * unfortunately, MTD does not provide this information. We should loop
668 * over all physical eraseblocks and invoke mtd->block_is_bad() for
669 * each physical eraseblock. So, we skip ubi->bad_peb_count
670 * uninitialized and initialize it after scanning.
677 * autoresize - re-size the volume which has the "auto-resize" flag set.
678 * @ubi: UBI device description object
679 * @vol_id: ID of the volume to re-size
681 * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
682 * the volume table to the largest possible size. See comments in ubi-header.h
683 * for more description of the flag. Returns zero in case of success and a
684 * negative error code in case of failure.
686 static int autoresize(struct ubi_device *ubi, int vol_id)
688 struct ubi_volume_desc desc;
689 struct ubi_volume *vol = ubi->volumes[vol_id];
690 int err, old_reserved_pebs = vol->reserved_pebs;
693 * Clear the auto-resize flag in the volume in-memory copy of the
694 * volume table, and 'ubi_resize_volume()' will propagate this change
697 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
699 if (ubi->avail_pebs == 0) {
700 struct ubi_vtbl_record vtbl_rec;
703 * No available PEBs to re-size the volume, clear the flag on
706 memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
707 sizeof(struct ubi_vtbl_record));
708 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
710 ubi_err("cannot clean auto-resize flag for volume %d",
714 err = ubi_resize_volume(&desc,
715 old_reserved_pebs + ubi->avail_pebs);
717 ubi_err("cannot auto-resize volume %d", vol_id);
723 ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
724 vol->name, old_reserved_pebs, vol->reserved_pebs);
729 * ubi_attach_mtd_dev - attach an MTD device.
730 * @mtd_dev: MTD device description object
731 * @ubi_num: number to assign to the new UBI device
732 * @vid_hdr_offset: VID header offset
734 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
735 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
736 * which case this function finds a vacant device number and assigns it
737 * automatically. Returns the new UBI device number in case of success and a
738 * negative error code in case of failure.
740 * Note, the invocations of this function has to be serialized by the
741 * @ubi_devices_mutex.
743 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
745 struct ubi_device *ubi;
746 int i, err, do_free = 1;
749 * Check if we already have the same MTD device attached.
751 * Note, this function assumes that UBI devices creations and deletions
752 * are serialized, so it does not take the &ubi_devices_lock.
754 for (i = 0; i < UBI_MAX_DEVICES; i++) {
755 ubi = ubi_devices[i];
756 if (ubi && mtd->index == ubi->mtd->index) {
757 dbg_err("mtd%d is already attached to ubi%d",
764 * Make sure this MTD device is not emulated on top of an UBI volume
765 * already. Well, generally this recursion works fine, but there are
766 * different problems like the UBI module takes a reference to itself
767 * by attaching (and thus, opening) the emulated MTD device. This
768 * results in inability to unload the module. And in general it makes
769 * no sense to attach emulated MTD devices, so we prohibit this.
771 if (mtd->type == MTD_UBIVOLUME) {
772 ubi_err("refuse attaching mtd%d - it is already emulated on "
773 "top of UBI", mtd->index);
777 if (ubi_num == UBI_DEV_NUM_AUTO) {
778 /* Search for an empty slot in the @ubi_devices array */
779 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
780 if (!ubi_devices[ubi_num])
782 if (ubi_num == UBI_MAX_DEVICES) {
783 dbg_err("only %d UBI devices may be created",
788 if (ubi_num >= UBI_MAX_DEVICES)
791 /* Make sure ubi_num is not busy */
792 if (ubi_devices[ubi_num]) {
793 dbg_err("ubi%d already exists", ubi_num);
798 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
803 ubi->ubi_num = ubi_num;
804 ubi->vid_hdr_offset = vid_hdr_offset;
805 ubi->autoresize_vol_id = -1;
807 mutex_init(&ubi->buf_mutex);
808 mutex_init(&ubi->ckvol_mutex);
809 mutex_init(&ubi->mult_mutex);
810 mutex_init(&ubi->volumes_mutex);
811 spin_lock_init(&ubi->volumes_lock);
813 ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
819 ubi->peb_buf1 = vmalloc(ubi->peb_size);
823 ubi->peb_buf2 = vmalloc(ubi->peb_size);
827 #ifdef CONFIG_MTD_UBI_DEBUG
828 mutex_init(&ubi->dbg_buf_mutex);
829 ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
830 if (!ubi->dbg_peb_buf)
834 err = attach_by_scanning(ubi);
836 dbg_err("failed to attach by scanning, error %d", err);
840 if (ubi->autoresize_vol_id != -1) {
841 err = autoresize(ubi, ubi->autoresize_vol_id);
850 ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
851 if (IS_ERR(ubi->bgt_thread)) {
852 err = PTR_ERR(ubi->bgt_thread);
853 ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
858 ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
859 ubi_msg("MTD device name: \"%s\"", mtd->name);
860 ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20);
861 ubi_msg("number of good PEBs: %d", ubi->good_peb_count);
862 ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count);
863 ubi_msg("max. allowed volumes: %d", ubi->vtbl_slots);
864 ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD);
865 ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
866 ubi_msg("number of user volumes: %d",
867 ubi->vol_count - UBI_INT_VOL_COUNT);
868 ubi_msg("available PEBs: %d", ubi->avail_pebs);
869 ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
870 ubi_msg("number of PEBs reserved for bad PEB handling: %d",
872 ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
874 /* Enable the background thread */
875 if (!DBG_DISABLE_BGT) {
876 ubi->thread_enabled = 1;
877 wake_up_process(ubi->bgt_thread);
880 ubi_devices[ubi_num] = ubi;
890 free_user_volumes(ubi);
891 free_internal_volumes(ubi);
894 vfree(ubi->peb_buf1);
895 vfree(ubi->peb_buf2);
896 #ifdef CONFIG_MTD_UBI_DEBUG
897 vfree(ubi->dbg_peb_buf);
904 * ubi_detach_mtd_dev - detach an MTD device.
905 * @ubi_num: UBI device number to detach from
906 * @anyway: detach MTD even if device reference count is not zero
908 * This function destroys an UBI device number @ubi_num and detaches the
909 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
910 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
913 * Note, the invocations of this function has to be serialized by the
914 * @ubi_devices_mutex.
916 int ubi_detach_mtd_dev(int ubi_num, int anyway)
918 struct ubi_device *ubi;
920 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
923 spin_lock(&ubi_devices_lock);
924 ubi = ubi_devices[ubi_num];
926 spin_unlock(&ubi_devices_lock);
930 if (ubi->ref_count) {
932 spin_unlock(&ubi_devices_lock);
935 /* This may only happen if there is a bug */
936 ubi_err("%s reference count %d, destroy anyway",
937 ubi->ubi_name, ubi->ref_count);
939 ubi_devices[ubi_num] = NULL;
940 spin_unlock(&ubi_devices_lock);
942 ubi_assert(ubi_num == ubi->ubi_num);
943 dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
946 * Before freeing anything, we have to stop the background thread to
947 * prevent it from doing anything on this device while we are freeing.
950 kthread_stop(ubi->bgt_thread);
954 free_internal_volumes(ubi);
956 put_mtd_device(ubi->mtd);
957 vfree(ubi->peb_buf1);
958 vfree(ubi->peb_buf2);
959 #ifdef CONFIG_MTD_UBI_DEBUG
960 vfree(ubi->dbg_peb_buf);
962 ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
968 * find_mtd_device - open an MTD device by its name or number.
969 * @mtd_dev: name or number of the device
971 * This function tries to open and MTD device described by @mtd_dev string,
972 * which is first treated as an ASCII number, and if it is not true, it is
973 * treated as MTD device name. Returns MTD device description object in case of
974 * success and a negative error code in case of failure.
976 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
978 struct mtd_info *mtd;
982 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
983 if (*endp != '\0' || mtd_dev == endp) {
985 * This does not look like an ASCII integer, probably this is
988 mtd = get_mtd_device_nm(mtd_dev);
990 mtd = get_mtd_device(NULL, mtd_num);
995 static int __init ubi_init(void)
999 /* Ensure that EC and VID headers have correct size */
1000 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1001 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1003 if (mtd_devs > UBI_MAX_DEVICES) {
1004 ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
1008 /* Create base sysfs directory and sysfs files */
1009 ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
1010 if (IS_ERR(ubi_class)) {
1011 err = PTR_ERR(ubi_class);
1012 ubi_err("cannot create UBI class");
1016 err = class_create_file(ubi_class, &ubi_version);
1018 ubi_err("cannot create sysfs file");
1022 err = misc_register(&ubi_ctrl_cdev);
1024 ubi_err("cannot register device");
1028 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1029 sizeof(struct ubi_wl_entry),
1031 if (!ubi_wl_entry_slab)
1034 /* Attach MTD devices */
1035 for (i = 0; i < mtd_devs; i++) {
1036 struct mtd_dev_param *p = &mtd_dev_param[i];
1037 struct mtd_info *mtd;
1041 mtd = open_mtd_device(p->name);
1047 mutex_lock(&ubi_devices_mutex);
1048 err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
1050 mutex_unlock(&ubi_devices_mutex);
1052 put_mtd_device(mtd);
1053 ubi_err("cannot attach mtd%d", mtd->index);
1061 for (k = 0; k < i; k++)
1062 if (ubi_devices[k]) {
1063 mutex_lock(&ubi_devices_mutex);
1064 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1065 mutex_unlock(&ubi_devices_mutex);
1067 kmem_cache_destroy(ubi_wl_entry_slab);
1069 misc_deregister(&ubi_ctrl_cdev);
1071 class_remove_file(ubi_class, &ubi_version);
1073 class_destroy(ubi_class);
1075 ubi_err("UBI error: cannot initialize UBI, error %d", err);
1078 module_init(ubi_init);
1080 static void __exit ubi_exit(void)
1084 for (i = 0; i < UBI_MAX_DEVICES; i++)
1085 if (ubi_devices[i]) {
1086 mutex_lock(&ubi_devices_mutex);
1087 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1088 mutex_unlock(&ubi_devices_mutex);
1090 kmem_cache_destroy(ubi_wl_entry_slab);
1091 misc_deregister(&ubi_ctrl_cdev);
1092 class_remove_file(ubi_class, &ubi_version);
1093 class_destroy(ubi_class);
1095 module_exit(ubi_exit);
1098 * bytes_str_to_int - convert a string representing number of bytes to an
1100 * @str: the string to convert
1102 * This function returns positive resulting integer in case of success and a
1103 * negative error code in case of failure.
1105 static int __init bytes_str_to_int(const char *str)
1108 unsigned long result;
1110 result = simple_strtoul(str, &endp, 0);
1111 if (str == endp || result < 0) {
1112 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1124 if (endp[1] == 'i' && endp[2] == 'B')
1129 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1138 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1139 * @val: the parameter value to parse
1142 * This function returns zero in case of success and a negative error code in
1145 static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1148 struct mtd_dev_param *p;
1149 char buf[MTD_PARAM_LEN_MAX];
1150 char *pbuf = &buf[0];
1151 char *tokens[2] = {NULL, NULL};
1156 if (mtd_devs == UBI_MAX_DEVICES) {
1157 printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
1162 len = strnlen(val, MTD_PARAM_LEN_MAX);
1163 if (len == MTD_PARAM_LEN_MAX) {
1164 printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
1165 "max. is %d\n", val, MTD_PARAM_LEN_MAX);
1170 printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
1177 /* Get rid of the final newline */
1178 if (buf[len - 1] == '\n')
1179 buf[len - 1] = '\0';
1181 for (i = 0; i < 2; i++)
1182 tokens[i] = strsep(&pbuf, ",");
1185 printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
1190 p = &mtd_dev_param[mtd_devs];
1191 strcpy(&p->name[0], tokens[0]);
1194 p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
1196 if (p->vid_hdr_offs < 0)
1197 return p->vid_hdr_offs;
1203 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1204 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
1205 "mtd=<name|num>[,<vid_hdr_offs>].\n"
1206 "Multiple \"mtd\" parameters may be specified.\n"
1207 "MTD devices may be specified by their number or name.\n"
1208 "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
1209 "header position and data starting position to be used "
1211 "Example: mtd=content,1984 mtd=4 - attach MTD device"
1212 "with name \"content\" using VID header offset 1984, and "
1213 "MTD device number 4 with default VID header offset.");
1215 MODULE_VERSION(__stringify(UBI_VERSION));
1216 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1217 MODULE_AUTHOR("Artem Bityutskiy");
1218 MODULE_LICENSE("GPL");