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 by character device major number.
163 * @major: major number
165 * This function is similar to 'ubi_get_device()', but it searches the device
166 * by its major number.
168 struct ubi_device *ubi_get_by_major(int major)
171 struct ubi_device *ubi;
173 spin_lock(&ubi_devices_lock);
174 for (i = 0; i < UBI_MAX_DEVICES; i++) {
175 ubi = ubi_devices[i];
176 if (ubi && MAJOR(ubi->cdev.dev) == major) {
177 ubi_assert(ubi->ref_count >= 0);
179 get_device(&ubi->dev);
180 spin_unlock(&ubi_devices_lock);
184 spin_unlock(&ubi_devices_lock);
190 * ubi_major2num - get UBI device number by character device major number.
191 * @major: major number
193 * This function searches UBI device number object by its major number. If UBI
194 * device was not found, this function returns -ENODEV, otherwise the UBI device
195 * number is returned.
197 int ubi_major2num(int major)
199 int i, ubi_num = -ENODEV;
201 spin_lock(&ubi_devices_lock);
202 for (i = 0; i < UBI_MAX_DEVICES; i++) {
203 struct ubi_device *ubi = ubi_devices[i];
205 if (ubi && MAJOR(ubi->cdev.dev) == major) {
206 ubi_num = ubi->ubi_num;
210 spin_unlock(&ubi_devices_lock);
215 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
216 static ssize_t dev_attribute_show(struct device *dev,
217 struct device_attribute *attr, char *buf)
220 struct ubi_device *ubi;
223 * The below code looks weird, but it actually makes sense. We get the
224 * UBI device reference from the contained 'struct ubi_device'. But it
225 * is unclear if the device was removed or not yet. Indeed, if the
226 * device was removed before we increased its reference count,
227 * 'ubi_get_device()' will return -ENODEV and we fail.
229 * Remember, 'struct ubi_device' is freed in the release function, so
230 * we still can use 'ubi->ubi_num'.
232 ubi = container_of(dev, struct ubi_device, dev);
233 ubi = ubi_get_device(ubi->ubi_num);
237 if (attr == &dev_eraseblock_size)
238 ret = sprintf(buf, "%d\n", ubi->leb_size);
239 else if (attr == &dev_avail_eraseblocks)
240 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
241 else if (attr == &dev_total_eraseblocks)
242 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
243 else if (attr == &dev_volumes_count)
244 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
245 else if (attr == &dev_max_ec)
246 ret = sprintf(buf, "%d\n", ubi->max_ec);
247 else if (attr == &dev_reserved_for_bad)
248 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
249 else if (attr == &dev_bad_peb_count)
250 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
251 else if (attr == &dev_max_vol_count)
252 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
253 else if (attr == &dev_min_io_size)
254 ret = sprintf(buf, "%d\n", ubi->min_io_size);
255 else if (attr == &dev_bgt_enabled)
256 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
257 else if (attr == &dev_mtd_num)
258 ret = sprintf(buf, "%d\n", ubi->mtd->index);
266 static void dev_release(struct device *dev)
268 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
274 * ubi_sysfs_init - initialize sysfs for an UBI device.
275 * @ubi: UBI device description object
277 * This function returns zero in case of success and a negative error code in
280 static int ubi_sysfs_init(struct ubi_device *ubi)
284 ubi->dev.release = dev_release;
285 ubi->dev.devt = ubi->cdev.dev;
286 ubi->dev.class = ubi_class;
287 dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
288 err = device_register(&ubi->dev);
292 err = device_create_file(&ubi->dev, &dev_eraseblock_size);
295 err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
298 err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
301 err = device_create_file(&ubi->dev, &dev_volumes_count);
304 err = device_create_file(&ubi->dev, &dev_max_ec);
307 err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
310 err = device_create_file(&ubi->dev, &dev_bad_peb_count);
313 err = device_create_file(&ubi->dev, &dev_max_vol_count);
316 err = device_create_file(&ubi->dev, &dev_min_io_size);
319 err = device_create_file(&ubi->dev, &dev_bgt_enabled);
322 err = device_create_file(&ubi->dev, &dev_mtd_num);
327 * ubi_sysfs_close - close sysfs for an UBI device.
328 * @ubi: UBI device description object
330 static void ubi_sysfs_close(struct ubi_device *ubi)
332 device_remove_file(&ubi->dev, &dev_mtd_num);
333 device_remove_file(&ubi->dev, &dev_bgt_enabled);
334 device_remove_file(&ubi->dev, &dev_min_io_size);
335 device_remove_file(&ubi->dev, &dev_max_vol_count);
336 device_remove_file(&ubi->dev, &dev_bad_peb_count);
337 device_remove_file(&ubi->dev, &dev_reserved_for_bad);
338 device_remove_file(&ubi->dev, &dev_max_ec);
339 device_remove_file(&ubi->dev, &dev_volumes_count);
340 device_remove_file(&ubi->dev, &dev_total_eraseblocks);
341 device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
342 device_remove_file(&ubi->dev, &dev_eraseblock_size);
343 device_unregister(&ubi->dev);
347 * kill_volumes - destroy all volumes.
348 * @ubi: UBI device description object
350 static void kill_volumes(struct ubi_device *ubi)
354 for (i = 0; i < ubi->vtbl_slots; i++)
356 ubi_free_volume(ubi, ubi->volumes[i]);
360 * free_user_volumes - free all user volumes.
361 * @ubi: UBI device description object
363 * Normally the volumes are freed at the release function of the volume device
364 * objects. However, on error paths the volumes have to be freed before the
365 * device objects have been initialized.
367 static void free_user_volumes(struct ubi_device *ubi)
371 for (i = 0; i < ubi->vtbl_slots; i++)
372 if (ubi->volumes[i]) {
373 kfree(ubi->volumes[i]->eba_tbl);
374 kfree(ubi->volumes[i]);
379 * uif_init - initialize user interfaces for an UBI device.
380 * @ubi: UBI device description object
382 * This function returns zero in case of success and a negative error code in
383 * case of failure. Note, this function destroys all volumes if it fails.
385 static int uif_init(struct ubi_device *ubi)
390 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
393 * Major numbers for the UBI character devices are allocated
394 * dynamically. Major numbers of volume character devices are
395 * equivalent to ones of the corresponding UBI character device. Minor
396 * numbers of UBI character devices are 0, while minor numbers of
397 * volume character devices start from 1. Thus, we allocate one major
398 * number and ubi->vtbl_slots + 1 minor numbers.
400 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
402 ubi_err("cannot register UBI character devices");
406 ubi_assert(MINOR(dev) == 0);
407 cdev_init(&ubi->cdev, &ubi_cdev_operations);
408 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
409 ubi->cdev.owner = THIS_MODULE;
411 err = cdev_add(&ubi->cdev, dev, 1);
413 ubi_err("cannot add character device");
417 err = ubi_sysfs_init(ubi);
421 for (i = 0; i < ubi->vtbl_slots; i++)
422 if (ubi->volumes[i]) {
423 err = ubi_add_volume(ubi, ubi->volumes[i]);
425 ubi_err("cannot add volume %d", i);
435 ubi_sysfs_close(ubi);
436 cdev_del(&ubi->cdev);
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 = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
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 * Set maximum amount of physical erroneous eraseblocks to be 10%.
637 * Erroneous PEB are those which have read errors.
639 ubi->max_erroneous = ubi->peb_count / 10;
640 if (ubi->max_erroneous < 16)
641 ubi->max_erroneous = 16;
642 dbg_msg("max_erroneous %d", ubi->max_erroneous);
645 * It may happen that EC and VID headers are situated in one minimal
646 * I/O unit. In this case we can only accept this UBI image in
649 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
650 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
651 "switch to read-only mode");
655 ubi->leb_size = ubi->peb_size - ubi->leb_start;
657 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
658 ubi_msg("MTD device %d is write-protected, attach in "
659 "read-only mode", ubi->mtd->index);
663 ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
664 ubi->peb_size, ubi->peb_size >> 10);
665 ubi_msg("logical eraseblock size: %d bytes", ubi->leb_size);
666 ubi_msg("smallest flash I/O unit: %d", ubi->min_io_size);
667 if (ubi->hdrs_min_io_size != ubi->min_io_size)
668 ubi_msg("sub-page size: %d",
669 ubi->hdrs_min_io_size);
670 ubi_msg("VID header offset: %d (aligned %d)",
671 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
672 ubi_msg("data offset: %d", ubi->leb_start);
675 * Note, ideally, we have to initialize ubi->bad_peb_count here. But
676 * unfortunately, MTD does not provide this information. We should loop
677 * over all physical eraseblocks and invoke mtd->block_is_bad() for
678 * each physical eraseblock. So, we skip ubi->bad_peb_count
679 * uninitialized and initialize it after scanning.
686 * autoresize - re-size the volume which has the "auto-resize" flag set.
687 * @ubi: UBI device description object
688 * @vol_id: ID of the volume to re-size
690 * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
691 * the volume table to the largest possible size. See comments in ubi-header.h
692 * for more description of the flag. Returns zero in case of success and a
693 * negative error code in case of failure.
695 static int autoresize(struct ubi_device *ubi, int vol_id)
697 struct ubi_volume_desc desc;
698 struct ubi_volume *vol = ubi->volumes[vol_id];
699 int err, old_reserved_pebs = vol->reserved_pebs;
702 * Clear the auto-resize flag in the volume in-memory copy of the
703 * volume table, and 'ubi_resize_volume()' will propagate this change
706 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
708 if (ubi->avail_pebs == 0) {
709 struct ubi_vtbl_record vtbl_rec;
712 * No available PEBs to re-size the volume, clear the flag on
715 memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
716 sizeof(struct ubi_vtbl_record));
717 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
719 ubi_err("cannot clean auto-resize flag for volume %d",
723 err = ubi_resize_volume(&desc,
724 old_reserved_pebs + ubi->avail_pebs);
726 ubi_err("cannot auto-resize volume %d", vol_id);
732 ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
733 vol->name, old_reserved_pebs, vol->reserved_pebs);
738 * ubi_attach_mtd_dev - attach an MTD device.
739 * @mtd: MTD device description object
740 * @ubi_num: number to assign to the new UBI device
741 * @vid_hdr_offset: VID header offset
743 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
744 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
745 * which case this function finds a vacant device number and assigns it
746 * automatically. Returns the new UBI device number in case of success and a
747 * negative error code in case of failure.
749 * Note, the invocations of this function has to be serialized by the
750 * @ubi_devices_mutex.
752 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
754 struct ubi_device *ubi;
755 int i, err, do_free = 1;
758 * Check if we already have the same MTD device attached.
760 * Note, this function assumes that UBI devices creations and deletions
761 * are serialized, so it does not take the &ubi_devices_lock.
763 for (i = 0; i < UBI_MAX_DEVICES; i++) {
764 ubi = ubi_devices[i];
765 if (ubi && mtd->index == ubi->mtd->index) {
766 dbg_err("mtd%d is already attached to ubi%d",
773 * Make sure this MTD device is not emulated on top of an UBI volume
774 * already. Well, generally this recursion works fine, but there are
775 * different problems like the UBI module takes a reference to itself
776 * by attaching (and thus, opening) the emulated MTD device. This
777 * results in inability to unload the module. And in general it makes
778 * no sense to attach emulated MTD devices, so we prohibit this.
780 if (mtd->type == MTD_UBIVOLUME) {
781 ubi_err("refuse attaching mtd%d - it is already emulated on "
782 "top of UBI", mtd->index);
786 if (ubi_num == UBI_DEV_NUM_AUTO) {
787 /* Search for an empty slot in the @ubi_devices array */
788 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
789 if (!ubi_devices[ubi_num])
791 if (ubi_num == UBI_MAX_DEVICES) {
792 dbg_err("only %d UBI devices may be created",
797 if (ubi_num >= UBI_MAX_DEVICES)
800 /* Make sure ubi_num is not busy */
801 if (ubi_devices[ubi_num]) {
802 dbg_err("ubi%d already exists", ubi_num);
807 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
812 ubi->ubi_num = ubi_num;
813 ubi->vid_hdr_offset = vid_hdr_offset;
814 ubi->autoresize_vol_id = -1;
816 mutex_init(&ubi->buf_mutex);
817 mutex_init(&ubi->ckvol_mutex);
818 mutex_init(&ubi->device_mutex);
819 spin_lock_init(&ubi->volumes_lock);
821 ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
828 ubi->peb_buf1 = vmalloc(ubi->peb_size);
832 ubi->peb_buf2 = vmalloc(ubi->peb_size);
836 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
837 mutex_init(&ubi->dbg_buf_mutex);
838 ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
839 if (!ubi->dbg_peb_buf)
843 err = attach_by_scanning(ubi);
845 dbg_err("failed to attach by scanning, error %d", err);
849 if (ubi->autoresize_vol_id != -1) {
850 err = autoresize(ubi, ubi->autoresize_vol_id);
859 ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
860 if (IS_ERR(ubi->bgt_thread)) {
861 err = PTR_ERR(ubi->bgt_thread);
862 ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
867 ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
868 ubi_msg("MTD device name: \"%s\"", mtd->name);
869 ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20);
870 ubi_msg("number of good PEBs: %d", ubi->good_peb_count);
871 ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count);
872 ubi_msg("max. allowed volumes: %d", ubi->vtbl_slots);
873 ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD);
874 ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
875 ubi_msg("number of user volumes: %d",
876 ubi->vol_count - UBI_INT_VOL_COUNT);
877 ubi_msg("available PEBs: %d", ubi->avail_pebs);
878 ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
879 ubi_msg("number of PEBs reserved for bad PEB handling: %d",
881 ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
884 * The below lock makes sure we do not race with 'ubi_thread()' which
885 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
887 spin_lock(&ubi->wl_lock);
888 if (!DBG_DISABLE_BGT)
889 ubi->thread_enabled = 1;
890 wake_up_process(ubi->bgt_thread);
891 spin_unlock(&ubi->wl_lock);
893 ubi_devices[ubi_num] = ubi;
903 free_user_volumes(ubi);
904 free_internal_volumes(ubi);
907 vfree(ubi->peb_buf1);
908 vfree(ubi->peb_buf2);
909 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
910 vfree(ubi->dbg_peb_buf);
917 * ubi_detach_mtd_dev - detach an MTD device.
918 * @ubi_num: UBI device number to detach from
919 * @anyway: detach MTD even if device reference count is not zero
921 * This function destroys an UBI device number @ubi_num and detaches the
922 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
923 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
926 * Note, the invocations of this function has to be serialized by the
927 * @ubi_devices_mutex.
929 int ubi_detach_mtd_dev(int ubi_num, int anyway)
931 struct ubi_device *ubi;
933 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
936 spin_lock(&ubi_devices_lock);
937 ubi = ubi_devices[ubi_num];
939 spin_unlock(&ubi_devices_lock);
943 if (ubi->ref_count) {
945 spin_unlock(&ubi_devices_lock);
948 /* This may only happen if there is a bug */
949 ubi_err("%s reference count %d, destroy anyway",
950 ubi->ubi_name, ubi->ref_count);
952 ubi_devices[ubi_num] = NULL;
953 spin_unlock(&ubi_devices_lock);
955 ubi_assert(ubi_num == ubi->ubi_num);
956 dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
959 * Before freeing anything, we have to stop the background thread to
960 * prevent it from doing anything on this device while we are freeing.
963 kthread_stop(ubi->bgt_thread);
966 * Get a reference to the device in order to prevent 'dev_release()'
967 * from freeing @ubi object.
969 get_device(&ubi->dev);
973 free_internal_volumes(ubi);
975 put_mtd_device(ubi->mtd);
976 vfree(ubi->peb_buf1);
977 vfree(ubi->peb_buf2);
978 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
979 vfree(ubi->dbg_peb_buf);
981 ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
982 put_device(&ubi->dev);
987 * find_mtd_device - open an MTD device by its name or number.
988 * @mtd_dev: name or number of the device
990 * This function tries to open and MTD device described by @mtd_dev string,
991 * which is first treated as an ASCII number, and if it is not true, it is
992 * treated as MTD device name. Returns MTD device description object in case of
993 * success and a negative error code in case of failure.
995 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
997 struct mtd_info *mtd;
1001 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1002 if (*endp != '\0' || mtd_dev == endp) {
1004 * This does not look like an ASCII integer, probably this is
1007 mtd = get_mtd_device_nm(mtd_dev);
1009 mtd = get_mtd_device(NULL, mtd_num);
1014 static int __init ubi_init(void)
1018 /* Ensure that EC and VID headers have correct size */
1019 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1020 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1022 if (mtd_devs > UBI_MAX_DEVICES) {
1023 ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
1027 /* Create base sysfs directory and sysfs files */
1028 ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
1029 if (IS_ERR(ubi_class)) {
1030 err = PTR_ERR(ubi_class);
1031 ubi_err("cannot create UBI class");
1035 err = class_create_file(ubi_class, &ubi_version);
1037 ubi_err("cannot create sysfs file");
1041 err = misc_register(&ubi_ctrl_cdev);
1043 ubi_err("cannot register device");
1047 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1048 sizeof(struct ubi_wl_entry),
1050 if (!ubi_wl_entry_slab)
1053 /* Attach MTD devices */
1054 for (i = 0; i < mtd_devs; i++) {
1055 struct mtd_dev_param *p = &mtd_dev_param[i];
1056 struct mtd_info *mtd;
1060 mtd = open_mtd_device(p->name);
1066 mutex_lock(&ubi_devices_mutex);
1067 err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
1069 mutex_unlock(&ubi_devices_mutex);
1071 put_mtd_device(mtd);
1072 ubi_err("cannot attach mtd%d", mtd->index);
1080 for (k = 0; k < i; k++)
1081 if (ubi_devices[k]) {
1082 mutex_lock(&ubi_devices_mutex);
1083 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1084 mutex_unlock(&ubi_devices_mutex);
1086 kmem_cache_destroy(ubi_wl_entry_slab);
1088 misc_deregister(&ubi_ctrl_cdev);
1090 class_remove_file(ubi_class, &ubi_version);
1092 class_destroy(ubi_class);
1094 ubi_err("UBI error: cannot initialize UBI, error %d", err);
1097 module_init(ubi_init);
1099 static void __exit ubi_exit(void)
1103 for (i = 0; i < UBI_MAX_DEVICES; i++)
1104 if (ubi_devices[i]) {
1105 mutex_lock(&ubi_devices_mutex);
1106 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1107 mutex_unlock(&ubi_devices_mutex);
1109 kmem_cache_destroy(ubi_wl_entry_slab);
1110 misc_deregister(&ubi_ctrl_cdev);
1111 class_remove_file(ubi_class, &ubi_version);
1112 class_destroy(ubi_class);
1114 module_exit(ubi_exit);
1117 * bytes_str_to_int - convert a number of bytes string into an integer.
1118 * @str: the string to convert
1120 * This function returns positive resulting integer in case of success and a
1121 * negative error code in case of failure.
1123 static int __init bytes_str_to_int(const char *str)
1126 unsigned long result;
1128 result = simple_strtoul(str, &endp, 0);
1129 if (str == endp || result < 0) {
1130 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1142 if (endp[1] == 'i' && endp[2] == 'B')
1147 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1156 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1157 * @val: the parameter value to parse
1160 * This function returns zero in case of success and a negative error code in
1163 static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1166 struct mtd_dev_param *p;
1167 char buf[MTD_PARAM_LEN_MAX];
1168 char *pbuf = &buf[0];
1169 char *tokens[2] = {NULL, NULL};
1174 if (mtd_devs == UBI_MAX_DEVICES) {
1175 printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
1180 len = strnlen(val, MTD_PARAM_LEN_MAX);
1181 if (len == MTD_PARAM_LEN_MAX) {
1182 printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
1183 "max. is %d\n", val, MTD_PARAM_LEN_MAX);
1188 printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
1195 /* Get rid of the final newline */
1196 if (buf[len - 1] == '\n')
1197 buf[len - 1] = '\0';
1199 for (i = 0; i < 2; i++)
1200 tokens[i] = strsep(&pbuf, ",");
1203 printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
1208 p = &mtd_dev_param[mtd_devs];
1209 strcpy(&p->name[0], tokens[0]);
1212 p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
1214 if (p->vid_hdr_offs < 0)
1215 return p->vid_hdr_offs;
1221 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1222 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
1223 "mtd=<name|num>[,<vid_hdr_offs>].\n"
1224 "Multiple \"mtd\" parameters may be specified.\n"
1225 "MTD devices may be specified by their number or name.\n"
1226 "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
1227 "header position and data starting position to be used "
1229 "Example: mtd=content,1984 mtd=4 - attach MTD device"
1230 "with name \"content\" using VID header offset 1984, and "
1231 "MTD device number 4 with default VID header offset.");
1233 MODULE_VERSION(__stringify(UBI_VERSION));
1234 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1235 MODULE_AUTHOR("Artem Bityutskiy");
1236 MODULE_LICENSE("GPL");