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
56 char name[MTD_PARAM_LEN_MAX];
60 /* Numbers of elements set in the @mtd_dev_param array */
61 static int mtd_devs = 0;
63 /* MTD devices specification parameters */
64 static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
66 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
67 struct class *ubi_class;
69 /* Slab cache for wear-leveling entries */
70 struct kmem_cache *ubi_wl_entry_slab;
72 /* UBI control character device */
73 static struct miscdevice ubi_ctrl_cdev = {
74 .minor = MISC_DYNAMIC_MINOR,
76 .fops = &ubi_ctrl_cdev_operations,
79 /* All UBI devices in system */
80 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
82 /* Serializes UBI devices creations and removals */
83 DEFINE_MUTEX(ubi_devices_mutex);
85 /* Protects @ubi_devices and @ubi->ref_count */
86 static DEFINE_SPINLOCK(ubi_devices_lock);
88 /* "Show" method for files in '/<sysfs>/class/ubi/' */
89 static ssize_t ubi_version_show(struct class *class, char *buf)
91 return sprintf(buf, "%d\n", UBI_VERSION);
94 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
95 static struct class_attribute ubi_version =
96 __ATTR(version, S_IRUGO, ubi_version_show, NULL);
98 static ssize_t dev_attribute_show(struct device *dev,
99 struct device_attribute *attr, char *buf);
101 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
102 static struct device_attribute dev_eraseblock_size =
103 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
104 static struct device_attribute dev_avail_eraseblocks =
105 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
106 static struct device_attribute dev_total_eraseblocks =
107 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
108 static struct device_attribute dev_volumes_count =
109 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
110 static struct device_attribute dev_max_ec =
111 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
112 static struct device_attribute dev_reserved_for_bad =
113 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
114 static struct device_attribute dev_bad_peb_count =
115 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
116 static struct device_attribute dev_max_vol_count =
117 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
118 static struct device_attribute dev_min_io_size =
119 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
120 static struct device_attribute dev_bgt_enabled =
121 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
122 static struct device_attribute dev_mtd_num =
123 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
126 * ubi_get_device - get UBI device.
127 * @ubi_num: UBI device number
129 * This function returns UBI device description object for UBI device number
130 * @ubi_num, or %NULL if the device does not exist. This function increases the
131 * device reference count to prevent removal of the device. In other words, the
132 * device cannot be removed if its reference count is not zero.
134 struct ubi_device *ubi_get_device(int ubi_num)
136 struct ubi_device *ubi;
138 spin_lock(&ubi_devices_lock);
139 ubi = ubi_devices[ubi_num];
141 ubi_assert(ubi->ref_count >= 0);
143 get_device(&ubi->dev);
145 spin_unlock(&ubi_devices_lock);
151 * ubi_put_device - drop an UBI device reference.
152 * @ubi: UBI device description object
154 void ubi_put_device(struct ubi_device *ubi)
156 spin_lock(&ubi_devices_lock);
158 put_device(&ubi->dev);
159 spin_unlock(&ubi_devices_lock);
163 * ubi_get_by_major - get UBI device description object by character device
165 * @major: major number
167 * This function is similar to 'ubi_get_device()', but it searches the device
168 * by its major number.
170 struct ubi_device *ubi_get_by_major(int major)
173 struct ubi_device *ubi;
175 spin_lock(&ubi_devices_lock);
176 for (i = 0; i < UBI_MAX_DEVICES; i++) {
177 ubi = ubi_devices[i];
178 if (ubi && MAJOR(ubi->cdev.dev) == major) {
179 ubi_assert(ubi->ref_count >= 0);
181 get_device(&ubi->dev);
182 spin_unlock(&ubi_devices_lock);
186 spin_unlock(&ubi_devices_lock);
192 * ubi_major2num - get UBI device number by character device major number.
193 * @major: major number
195 * This function searches UBI device number object by its major number. If UBI
196 * device was not found, this function returns -ENODEV, otherwise the UBI device
197 * number is returned.
199 int ubi_major2num(int major)
201 int i, ubi_num = -ENODEV;
203 spin_lock(&ubi_devices_lock);
204 for (i = 0; i < UBI_MAX_DEVICES; i++) {
205 struct ubi_device *ubi = ubi_devices[i];
207 if (ubi && MAJOR(ubi->cdev.dev) == major) {
208 ubi_num = ubi->ubi_num;
212 spin_unlock(&ubi_devices_lock);
217 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
218 static ssize_t dev_attribute_show(struct device *dev,
219 struct device_attribute *attr, char *buf)
222 struct ubi_device *ubi;
225 * The below code looks weird, but it actually makes sense. We get the
226 * UBI device reference from the contained 'struct ubi_device'. But it
227 * is unclear if the device was removed or not yet. Indeed, if the
228 * device was removed before we increased its reference count,
229 * 'ubi_get_device()' will return -ENODEV and we fail.
231 * Remember, 'struct ubi_device' is freed in the release function, so
232 * we still can use 'ubi->ubi_num'.
234 ubi = container_of(dev, struct ubi_device, dev);
235 ubi = ubi_get_device(ubi->ubi_num);
239 if (attr == &dev_eraseblock_size)
240 ret = sprintf(buf, "%d\n", ubi->leb_size);
241 else if (attr == &dev_avail_eraseblocks)
242 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
243 else if (attr == &dev_total_eraseblocks)
244 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
245 else if (attr == &dev_volumes_count)
246 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
247 else if (attr == &dev_max_ec)
248 ret = sprintf(buf, "%d\n", ubi->max_ec);
249 else if (attr == &dev_reserved_for_bad)
250 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
251 else if (attr == &dev_bad_peb_count)
252 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
253 else if (attr == &dev_max_vol_count)
254 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
255 else if (attr == &dev_min_io_size)
256 ret = sprintf(buf, "%d\n", ubi->min_io_size);
257 else if (attr == &dev_bgt_enabled)
258 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
259 else if (attr == &dev_mtd_num)
260 ret = sprintf(buf, "%d\n", ubi->mtd->index);
268 /* Fake "release" method for UBI devices */
269 static void dev_release(struct device *dev) { }
272 * ubi_sysfs_init - initialize sysfs for an UBI device.
273 * @ubi: UBI device description object
275 * This function returns zero in case of success and a negative error code in
278 static int ubi_sysfs_init(struct ubi_device *ubi)
282 ubi->dev.release = dev_release;
283 ubi->dev.devt = ubi->cdev.dev;
284 ubi->dev.class = ubi_class;
285 sprintf(&ubi->dev.bus_id[0], UBI_NAME_STR"%d", ubi->ubi_num);
286 err = device_register(&ubi->dev);
290 err = device_create_file(&ubi->dev, &dev_eraseblock_size);
293 err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
296 err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
299 err = device_create_file(&ubi->dev, &dev_volumes_count);
302 err = device_create_file(&ubi->dev, &dev_max_ec);
305 err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
308 err = device_create_file(&ubi->dev, &dev_bad_peb_count);
311 err = device_create_file(&ubi->dev, &dev_max_vol_count);
314 err = device_create_file(&ubi->dev, &dev_min_io_size);
317 err = device_create_file(&ubi->dev, &dev_bgt_enabled);
320 err = device_create_file(&ubi->dev, &dev_mtd_num);
325 * ubi_sysfs_close - close sysfs for an UBI device.
326 * @ubi: UBI device description object
328 static void ubi_sysfs_close(struct ubi_device *ubi)
330 device_remove_file(&ubi->dev, &dev_mtd_num);
331 device_remove_file(&ubi->dev, &dev_bgt_enabled);
332 device_remove_file(&ubi->dev, &dev_min_io_size);
333 device_remove_file(&ubi->dev, &dev_max_vol_count);
334 device_remove_file(&ubi->dev, &dev_bad_peb_count);
335 device_remove_file(&ubi->dev, &dev_reserved_for_bad);
336 device_remove_file(&ubi->dev, &dev_max_ec);
337 device_remove_file(&ubi->dev, &dev_volumes_count);
338 device_remove_file(&ubi->dev, &dev_total_eraseblocks);
339 device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
340 device_remove_file(&ubi->dev, &dev_eraseblock_size);
341 device_unregister(&ubi->dev);
345 * kill_volumes - destroy all volumes.
346 * @ubi: UBI device description object
348 static void kill_volumes(struct ubi_device *ubi)
352 for (i = 0; i < ubi->vtbl_slots; i++)
354 ubi_free_volume(ubi, ubi->volumes[i]);
358 * uif_init - initialize user interfaces for an UBI device.
359 * @ubi: UBI device description object
361 * This function returns zero in case of success and a negative error code in
364 static int uif_init(struct ubi_device *ubi)
369 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
372 * Major numbers for the UBI character devices are allocated
373 * dynamically. Major numbers of volume character devices are
374 * equivalent to ones of the corresponding UBI character device. Minor
375 * numbers of UBI character devices are 0, while minor numbers of
376 * volume character devices start from 1. Thus, we allocate one major
377 * number and ubi->vtbl_slots + 1 minor numbers.
379 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
381 ubi_err("cannot register UBI character devices");
385 ubi_assert(MINOR(dev) == 0);
386 cdev_init(&ubi->cdev, &ubi_cdev_operations);
387 dbg_msg("%s major is %u", ubi->ubi_name, MAJOR(dev));
388 ubi->cdev.owner = THIS_MODULE;
390 err = cdev_add(&ubi->cdev, dev, 1);
392 ubi_err("cannot add character device");
396 err = ubi_sysfs_init(ubi);
400 for (i = 0; i < ubi->vtbl_slots; i++)
401 if (ubi->volumes[i]) {
402 err = ubi_add_volume(ubi, ubi->volumes[i]);
404 ubi_err("cannot add volume %d", i);
414 ubi_sysfs_close(ubi);
415 cdev_del(&ubi->cdev);
417 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
418 ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
423 * uif_close - close user interfaces for an UBI device.
424 * @ubi: UBI device description object
426 * Note, since this function un-registers UBI volume device objects (@vol->dev),
427 * the memory allocated voe the volumes is freed as well (in the release
430 static void uif_close(struct ubi_device *ubi)
433 ubi_sysfs_close(ubi);
434 cdev_del(&ubi->cdev);
435 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
439 * free_internal_volumes - free internal volumes.
440 * @ubi: UBI device description object
442 static void free_internal_volumes(struct ubi_device *ubi)
446 for (i = ubi->vtbl_slots;
447 i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
448 kfree(ubi->volumes[i]->eba_tbl);
449 kfree(ubi->volumes[i]);
454 * attach_by_scanning - attach an MTD device using scanning method.
455 * @ubi: UBI device descriptor
457 * This function returns zero in case of success and a negative error code in
460 * Note, currently this is the only method to attach UBI devices. Hopefully in
461 * the future we'll have more scalable attaching methods and avoid full media
462 * scanning. But even in this case scanning will be needed as a fall-back
463 * attaching method if there are some on-flash table corruptions.
465 static int attach_by_scanning(struct ubi_device *ubi)
468 struct ubi_scan_info *si;
474 ubi->bad_peb_count = si->bad_peb_count;
475 ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
476 ubi->max_ec = si->max_ec;
477 ubi->mean_ec = si->mean_ec;
479 err = ubi_read_volume_table(ubi, si);
483 err = ubi_wl_init_scan(ubi, si);
487 err = ubi_eba_init_scan(ubi, si);
491 ubi_scan_destroy_si(si);
497 free_internal_volumes(ubi);
500 ubi_scan_destroy_si(si);
505 * io_init - initialize I/O unit for a given UBI device.
506 * @ubi: UBI device description object
508 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
510 * o EC header is always at offset zero - this cannot be changed;
511 * o VID header starts just after the EC header at the closest address
512 * aligned to @io->hdrs_min_io_size;
513 * o data starts just after the VID header at the closest address aligned to
516 * This function returns zero in case of success and a negative error code in
519 static int io_init(struct ubi_device *ubi)
521 if (ubi->mtd->numeraseregions != 0) {
523 * Some flashes have several erase regions. Different regions
524 * may have different eraseblock size and other
525 * characteristics. It looks like mostly multi-region flashes
526 * have one "main" region and one or more small regions to
527 * store boot loader code or boot parameters or whatever. I
528 * guess we should just pick the largest region. But this is
531 ubi_err("multiple regions, not implemented");
535 if (ubi->vid_hdr_offset < 0)
539 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
540 * physical eraseblocks maximum.
543 ubi->peb_size = ubi->mtd->erasesize;
544 ubi->peb_count = ubi->mtd->size / ubi->mtd->erasesize;
545 ubi->flash_size = ubi->mtd->size;
547 if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
548 ubi->bad_allowed = 1;
550 ubi->min_io_size = ubi->mtd->writesize;
551 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
554 * Make sure minimal I/O unit is power of 2. Note, there is no
555 * fundamental reason for this assumption. It is just an optimization
556 * which allows us to avoid costly division operations.
558 if (!is_power_of_2(ubi->min_io_size)) {
559 ubi_err("min. I/O unit (%d) is not power of 2",
564 ubi_assert(ubi->hdrs_min_io_size > 0);
565 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
566 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
568 /* Calculate default aligned sizes of EC and VID headers */
569 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
570 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
572 dbg_msg("min_io_size %d", ubi->min_io_size);
573 dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
574 dbg_msg("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
575 dbg_msg("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
577 if (ubi->vid_hdr_offset == 0)
579 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
582 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
583 ~(ubi->hdrs_min_io_size - 1);
584 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
585 ubi->vid_hdr_aloffset;
588 /* Similar for the data offset */
589 ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
590 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
592 dbg_msg("vid_hdr_offset %d", ubi->vid_hdr_offset);
593 dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
594 dbg_msg("vid_hdr_shift %d", ubi->vid_hdr_shift);
595 dbg_msg("leb_start %d", ubi->leb_start);
597 /* The shift must be aligned to 32-bit boundary */
598 if (ubi->vid_hdr_shift % 4) {
599 ubi_err("unaligned VID header shift %d",
605 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
606 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
607 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
608 ubi->leb_start & (ubi->min_io_size - 1)) {
609 ubi_err("bad VID header (%d) or data offsets (%d)",
610 ubi->vid_hdr_offset, ubi->leb_start);
615 * It may happen that EC and VID headers are situated in one minimal
616 * I/O unit. In this case we can only accept this UBI image in
619 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
620 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
621 "switch to read-only mode");
625 ubi->leb_size = ubi->peb_size - ubi->leb_start;
627 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
628 ubi_msg("MTD device %d is write-protected, attach in "
629 "read-only mode", ubi->mtd->index);
633 ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
634 ubi->peb_size, ubi->peb_size >> 10);
635 ubi_msg("logical eraseblock size: %d bytes", ubi->leb_size);
636 ubi_msg("smallest flash I/O unit: %d", ubi->min_io_size);
637 if (ubi->hdrs_min_io_size != ubi->min_io_size)
638 ubi_msg("sub-page size: %d",
639 ubi->hdrs_min_io_size);
640 ubi_msg("VID header offset: %d (aligned %d)",
641 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
642 ubi_msg("data offset: %d", ubi->leb_start);
645 * Note, ideally, we have to initialize ubi->bad_peb_count here. But
646 * unfortunately, MTD does not provide this information. We should loop
647 * over all physical eraseblocks and invoke mtd->block_is_bad() for
648 * each physical eraseblock. So, we skip ubi->bad_peb_count
649 * uninitialized and initialize it after scanning.
656 * autoresize - re-size the volume which has the "auto-resize" flag set.
657 * @ubi: UBI device description object
658 * @vol_id: ID of the volume to re-size
660 * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
661 * the volume table to the largest possible size. See comments in ubi-header.h
662 * for more description of the flag. Returns zero in case of success and a
663 * negative error code in case of failure.
665 static int autoresize(struct ubi_device *ubi, int vol_id)
667 struct ubi_volume_desc desc;
668 struct ubi_volume *vol = ubi->volumes[vol_id];
669 int err, old_reserved_pebs = vol->reserved_pebs;
672 * Clear the auto-resize flag in the volume in-memory copy of the
673 * volume table, and 'ubi_resize_volume()' will propagate this change
676 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
678 if (ubi->avail_pebs == 0) {
679 struct ubi_vtbl_record vtbl_rec;
682 * No available PEBs to re-size the volume, clear the flag on
685 memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
686 sizeof(struct ubi_vtbl_record));
687 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
689 ubi_err("cannot clean auto-resize flag for volume %d",
693 err = ubi_resize_volume(&desc,
694 old_reserved_pebs + ubi->avail_pebs);
696 ubi_err("cannot auto-resize volume %d", vol_id);
702 ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
703 vol->name, old_reserved_pebs, vol->reserved_pebs);
708 * ubi_attach_mtd_dev - attach an MTD device.
709 * @mtd_dev: MTD device description object
710 * @ubi_num: number to assign to the new UBI device
711 * @vid_hdr_offset: VID header offset
713 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
714 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
715 * which case this function finds a vacant device number and assigns it
716 * automatically. Returns the new UBI device number in case of success and a
717 * negative error code in case of failure.
719 * Note, the invocations of this function has to be serialized by the
720 * @ubi_devices_mutex.
722 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
724 struct ubi_device *ubi;
728 * Check if we already have the same MTD device attached.
730 * Note, this function assumes that UBI devices creations and deletions
731 * are serialized, so it does not take the &ubi_devices_lock.
733 for (i = 0; i < UBI_MAX_DEVICES; i++) {
734 ubi = ubi_devices[i];
735 if (ubi && mtd->index == ubi->mtd->index) {
736 dbg_err("mtd%d is already attached to ubi%d",
743 * Make sure this MTD device is not emulated on top of an UBI volume
744 * already. Well, generally this recursion works fine, but there are
745 * different problems like the UBI module takes a reference to itself
746 * by attaching (and thus, opening) the emulated MTD device. This
747 * results in inability to unload the module. And in general it makes
748 * no sense to attach emulated MTD devices, so we prohibit this.
750 if (mtd->type == MTD_UBIVOLUME) {
751 ubi_err("refuse attaching mtd%d - it is already emulated on "
752 "top of UBI", mtd->index);
756 if (ubi_num == UBI_DEV_NUM_AUTO) {
757 /* Search for an empty slot in the @ubi_devices array */
758 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
759 if (!ubi_devices[ubi_num])
761 if (ubi_num == UBI_MAX_DEVICES) {
762 dbg_err("only %d UBI devices may be created", UBI_MAX_DEVICES);
766 if (ubi_num >= UBI_MAX_DEVICES)
769 /* Make sure ubi_num is not busy */
770 if (ubi_devices[ubi_num]) {
771 dbg_err("ubi%d already exists", ubi_num);
776 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
781 ubi->ubi_num = ubi_num;
782 ubi->vid_hdr_offset = vid_hdr_offset;
783 ubi->autoresize_vol_id = -1;
785 mutex_init(&ubi->buf_mutex);
786 mutex_init(&ubi->ckvol_mutex);
787 mutex_init(&ubi->volumes_mutex);
788 spin_lock_init(&ubi->volumes_lock);
790 ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
796 ubi->peb_buf1 = vmalloc(ubi->peb_size);
800 ubi->peb_buf2 = vmalloc(ubi->peb_size);
804 #ifdef CONFIG_MTD_UBI_DEBUG
805 mutex_init(&ubi->dbg_buf_mutex);
806 ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
807 if (!ubi->dbg_peb_buf)
811 err = attach_by_scanning(ubi);
813 dbg_err("failed to attach by scanning, error %d", err);
817 if (ubi->autoresize_vol_id != -1) {
818 err = autoresize(ubi, ubi->autoresize_vol_id);
827 ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
828 if (IS_ERR(ubi->bgt_thread)) {
829 err = PTR_ERR(ubi->bgt_thread);
830 ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
835 ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
836 ubi_msg("MTD device name: \"%s\"", mtd->name);
837 ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20);
838 ubi_msg("number of good PEBs: %d", ubi->good_peb_count);
839 ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count);
840 ubi_msg("max. allowed volumes: %d", ubi->vtbl_slots);
841 ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD);
842 ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
843 ubi_msg("number of user volumes: %d",
844 ubi->vol_count - UBI_INT_VOL_COUNT);
845 ubi_msg("available PEBs: %d", ubi->avail_pebs);
846 ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
847 ubi_msg("number of PEBs reserved for bad PEB handling: %d",
849 ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
851 /* Enable the background thread */
852 if (!DBG_DISABLE_BGT) {
853 ubi->thread_enabled = 1;
854 wake_up_process(ubi->bgt_thread);
857 ubi_devices[ubi_num] = ubi;
864 free_internal_volumes(ubi);
867 vfree(ubi->peb_buf1);
868 vfree(ubi->peb_buf2);
869 #ifdef CONFIG_MTD_UBI_DEBUG
870 vfree(ubi->dbg_peb_buf);
877 * ubi_detach_mtd_dev - detach an MTD device.
878 * @ubi_num: UBI device number to detach from
879 * @anyway: detach MTD even if device reference count is not zero
881 * This function destroys an UBI device number @ubi_num and detaches the
882 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
883 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
886 * Note, the invocations of this function has to be serialized by the
887 * @ubi_devices_mutex.
889 int ubi_detach_mtd_dev(int ubi_num, int anyway)
891 struct ubi_device *ubi;
893 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
896 spin_lock(&ubi_devices_lock);
897 ubi = ubi_devices[ubi_num];
899 spin_unlock(&ubi_devices_lock);
903 if (ubi->ref_count) {
905 spin_unlock(&ubi_devices_lock);
908 /* This may only happen if there is a bug */
909 ubi_err("%s reference count %d, destroy anyway",
910 ubi->ubi_name, ubi->ref_count);
912 ubi_devices[ubi_num] = NULL;
913 spin_unlock(&ubi_devices_lock);
915 ubi_assert(ubi_num == ubi->ubi_num);
916 dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
919 * Before freeing anything, we have to stop the background thread to
920 * prevent it from doing anything on this device while we are freeing.
923 kthread_stop(ubi->bgt_thread);
927 free_internal_volumes(ubi);
929 put_mtd_device(ubi->mtd);
930 vfree(ubi->peb_buf1);
931 vfree(ubi->peb_buf2);
932 #ifdef CONFIG_MTD_UBI_DEBUG
933 vfree(ubi->dbg_peb_buf);
935 ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
941 * find_mtd_device - open an MTD device by its name or number.
942 * @mtd_dev: name or number of the device
944 * This function tries to open and MTD device described by @mtd_dev string,
945 * which is first treated as an ASCII number, and if it is not true, it is
946 * treated as MTD device name. Returns MTD device description object in case of
947 * success and a negative error code in case of failure.
949 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
951 struct mtd_info *mtd;
955 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
956 if (*endp != '\0' || mtd_dev == endp) {
958 * This does not look like an ASCII integer, probably this is
961 mtd = get_mtd_device_nm(mtd_dev);
963 mtd = get_mtd_device(NULL, mtd_num);
968 static int __init ubi_init(void)
972 /* Ensure that EC and VID headers have correct size */
973 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
974 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
976 if (mtd_devs > UBI_MAX_DEVICES) {
977 ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
981 /* Create base sysfs directory and sysfs files */
982 ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
983 if (IS_ERR(ubi_class)) {
984 err = PTR_ERR(ubi_class);
985 ubi_err("cannot create UBI class");
989 err = class_create_file(ubi_class, &ubi_version);
991 ubi_err("cannot create sysfs file");
995 err = misc_register(&ubi_ctrl_cdev);
997 ubi_err("cannot register device");
1001 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1002 sizeof(struct ubi_wl_entry),
1004 if (!ubi_wl_entry_slab)
1007 /* Attach MTD devices */
1008 for (i = 0; i < mtd_devs; i++) {
1009 struct mtd_dev_param *p = &mtd_dev_param[i];
1010 struct mtd_info *mtd;
1014 mtd = open_mtd_device(p->name);
1020 mutex_lock(&ubi_devices_mutex);
1021 err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
1023 mutex_unlock(&ubi_devices_mutex);
1025 put_mtd_device(mtd);
1026 ubi_err("cannot attach mtd%d", mtd->index);
1034 for (k = 0; k < i; k++)
1035 if (ubi_devices[k]) {
1036 mutex_lock(&ubi_devices_mutex);
1037 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1038 mutex_unlock(&ubi_devices_mutex);
1040 kmem_cache_destroy(ubi_wl_entry_slab);
1042 misc_deregister(&ubi_ctrl_cdev);
1044 class_remove_file(ubi_class, &ubi_version);
1046 class_destroy(ubi_class);
1048 ubi_err("UBI error: cannot initialize UBI, error %d", err);
1051 module_init(ubi_init);
1053 static void __exit ubi_exit(void)
1057 for (i = 0; i < UBI_MAX_DEVICES; i++)
1058 if (ubi_devices[i]) {
1059 mutex_lock(&ubi_devices_mutex);
1060 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1061 mutex_unlock(&ubi_devices_mutex);
1063 kmem_cache_destroy(ubi_wl_entry_slab);
1064 misc_deregister(&ubi_ctrl_cdev);
1065 class_remove_file(ubi_class, &ubi_version);
1066 class_destroy(ubi_class);
1068 module_exit(ubi_exit);
1071 * bytes_str_to_int - convert a string representing number of bytes to an
1073 * @str: the string to convert
1075 * This function returns positive resulting integer in case of success and a
1076 * negative error code in case of failure.
1078 static int __init bytes_str_to_int(const char *str)
1081 unsigned long result;
1083 result = simple_strtoul(str, &endp, 0);
1084 if (str == endp || result < 0) {
1085 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1097 if (endp[1] == 'i' && endp[2] == 'B')
1102 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1111 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1112 * @val: the parameter value to parse
1115 * This function returns zero in case of success and a negative error code in
1118 static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1121 struct mtd_dev_param *p;
1122 char buf[MTD_PARAM_LEN_MAX];
1123 char *pbuf = &buf[0];
1124 char *tokens[2] = {NULL, NULL};
1129 if (mtd_devs == UBI_MAX_DEVICES) {
1130 printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
1135 len = strnlen(val, MTD_PARAM_LEN_MAX);
1136 if (len == MTD_PARAM_LEN_MAX) {
1137 printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
1138 "max. is %d\n", val, MTD_PARAM_LEN_MAX);
1143 printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
1150 /* Get rid of the final newline */
1151 if (buf[len - 1] == '\n')
1152 buf[len - 1] = '\0';
1154 for (i = 0; i < 2; i++)
1155 tokens[i] = strsep(&pbuf, ",");
1158 printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
1163 p = &mtd_dev_param[mtd_devs];
1164 strcpy(&p->name[0], tokens[0]);
1167 p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
1169 if (p->vid_hdr_offs < 0)
1170 return p->vid_hdr_offs;
1176 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1177 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
1178 "mtd=<name|num>[,<vid_hdr_offs>].\n"
1179 "Multiple \"mtd\" parameters may be specified.\n"
1180 "MTD devices may be specified by their number or name.\n"
1181 "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
1182 "header position and data starting position to be used "
1184 "Example: mtd=content,1984 mtd=4 - attach MTD device"
1185 "with name \"content\" using VID header offset 1984, and "
1186 "MTD device number 4 with default VID header offset.");
1188 MODULE_VERSION(__stringify(UBI_VERSION));
1189 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1190 MODULE_AUTHOR("Artem Bityutskiy");
1191 MODULE_LICENSE("GPL");