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".
32 #include <linux/err.h>
33 #include <linux/module.h>
34 #include <linux/moduleparam.h>
35 #include <linux/stringify.h>
36 #include <linux/namei.h>
37 #include <linux/stat.h>
38 #include <linux/miscdevice.h>
39 #include <linux/mtd/partitions.h>
40 #include <linux/log2.h>
41 #include <linux/kthread.h>
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
46 /* Maximum length of the 'mtd=' parameter */
47 #define MTD_PARAM_LEN_MAX 64
49 /* Maximum number of comma-separated items in the 'mtd=' parameter */
50 #define MTD_PARAM_MAX_COUNT 3
52 /* Maximum value for the number of bad PEBs per 1024 PEBs */
53 #define MAX_MTD_UBI_BEB_LIMIT 768
55 #ifdef CONFIG_MTD_UBI_MODULE
56 #define ubi_is_module() 1
58 #define ubi_is_module() 0
62 * struct mtd_dev_param - MTD device parameter description data structure.
63 * @name: MTD character device node path, MTD device name, or MTD device number
65 * @vid_hdr_offs: VID header offset
66 * @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
68 struct mtd_dev_param {
69 char name[MTD_PARAM_LEN_MAX];
74 /* Numbers of elements set in the @mtd_dev_param array */
75 static int __initdata mtd_devs;
77 /* MTD devices specification parameters */
78 static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
80 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
81 struct class *ubi_class;
83 /* Slab cache for wear-leveling entries */
84 struct kmem_cache *ubi_wl_entry_slab;
86 /* UBI control character device */
87 static struct miscdevice ubi_ctrl_cdev = {
88 .minor = MISC_DYNAMIC_MINOR,
90 .fops = &ubi_ctrl_cdev_operations,
93 /* All UBI devices in system */
94 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
96 /* Serializes UBI devices creations and removals */
97 DEFINE_MUTEX(ubi_devices_mutex);
99 /* Protects @ubi_devices and @ubi->ref_count */
100 static DEFINE_SPINLOCK(ubi_devices_lock);
102 /* "Show" method for files in '/<sysfs>/class/ubi/' */
103 static ssize_t ubi_version_show(struct class *class,
104 struct class_attribute *attr, char *buf)
106 return sprintf(buf, "%d\n", UBI_VERSION);
109 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
110 static struct class_attribute ubi_version =
111 __ATTR(version, S_IRUGO, ubi_version_show, NULL);
113 static ssize_t dev_attribute_show(struct device *dev,
114 struct device_attribute *attr, char *buf);
116 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
117 static struct device_attribute dev_eraseblock_size =
118 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
119 static struct device_attribute dev_avail_eraseblocks =
120 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
121 static struct device_attribute dev_total_eraseblocks =
122 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
123 static struct device_attribute dev_volumes_count =
124 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
125 static struct device_attribute dev_max_ec =
126 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
127 static struct device_attribute dev_reserved_for_bad =
128 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
129 static struct device_attribute dev_bad_peb_count =
130 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
131 static struct device_attribute dev_max_vol_count =
132 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
133 static struct device_attribute dev_min_io_size =
134 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
135 static struct device_attribute dev_bgt_enabled =
136 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
137 static struct device_attribute dev_mtd_num =
138 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
141 * ubi_volume_notify - send a volume change notification.
142 * @ubi: UBI device description object
143 * @vol: volume description object of the changed volume
144 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
146 * This is a helper function which notifies all subscribers about a volume
147 * change event (creation, removal, re-sizing, re-naming, updating). Returns
148 * zero in case of success and a negative error code in case of failure.
150 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
152 struct ubi_notification nt;
154 ubi_do_get_device_info(ubi, &nt.di);
155 ubi_do_get_volume_info(ubi, vol, &nt.vi);
156 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
160 * ubi_notify_all - send a notification to all volumes.
161 * @ubi: UBI device description object
162 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
163 * @nb: the notifier to call
165 * This function walks all volumes of UBI device @ubi and sends the @ntype
166 * notification for each volume. If @nb is %NULL, then all registered notifiers
167 * are called, otherwise only the @nb notifier is called. Returns the number of
168 * sent notifications.
170 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
172 struct ubi_notification nt;
175 ubi_do_get_device_info(ubi, &nt.di);
177 mutex_lock(&ubi->device_mutex);
178 for (i = 0; i < ubi->vtbl_slots; i++) {
180 * Since the @ubi->device is locked, and we are not going to
181 * change @ubi->volumes, we do not have to lock
182 * @ubi->volumes_lock.
184 if (!ubi->volumes[i])
187 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
189 nb->notifier_call(nb, ntype, &nt);
191 blocking_notifier_call_chain(&ubi_notifiers, ntype,
195 mutex_unlock(&ubi->device_mutex);
201 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
202 * @nb: the notifier to call
204 * This function walks all UBI devices and volumes and sends the
205 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
206 * registered notifiers are called, otherwise only the @nb notifier is called.
207 * Returns the number of sent notifications.
209 int ubi_enumerate_volumes(struct notifier_block *nb)
214 * Since the @ubi_devices_mutex is locked, and we are not going to
215 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
217 for (i = 0; i < UBI_MAX_DEVICES; i++) {
218 struct ubi_device *ubi = ubi_devices[i];
222 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
229 * ubi_get_device - get UBI device.
230 * @ubi_num: UBI device number
232 * This function returns UBI device description object for UBI device number
233 * @ubi_num, or %NULL if the device does not exist. This function increases the
234 * device reference count to prevent removal of the device. In other words, the
235 * device cannot be removed if its reference count is not zero.
237 struct ubi_device *ubi_get_device(int ubi_num)
239 struct ubi_device *ubi;
241 spin_lock(&ubi_devices_lock);
242 ubi = ubi_devices[ubi_num];
244 ubi_assert(ubi->ref_count >= 0);
246 get_device(&ubi->dev);
248 spin_unlock(&ubi_devices_lock);
254 * ubi_put_device - drop an UBI device reference.
255 * @ubi: UBI device description object
257 void ubi_put_device(struct ubi_device *ubi)
259 spin_lock(&ubi_devices_lock);
261 put_device(&ubi->dev);
262 spin_unlock(&ubi_devices_lock);
266 * ubi_get_by_major - get UBI device by character device major number.
267 * @major: major number
269 * This function is similar to 'ubi_get_device()', but it searches the device
270 * by its major number.
272 struct ubi_device *ubi_get_by_major(int major)
275 struct ubi_device *ubi;
277 spin_lock(&ubi_devices_lock);
278 for (i = 0; i < UBI_MAX_DEVICES; i++) {
279 ubi = ubi_devices[i];
280 if (ubi && MAJOR(ubi->cdev.dev) == major) {
281 ubi_assert(ubi->ref_count >= 0);
283 get_device(&ubi->dev);
284 spin_unlock(&ubi_devices_lock);
288 spin_unlock(&ubi_devices_lock);
294 * ubi_major2num - get UBI device number by character device major number.
295 * @major: major number
297 * This function searches UBI device number object by its major number. If UBI
298 * device was not found, this function returns -ENODEV, otherwise the UBI device
299 * number is returned.
301 int ubi_major2num(int major)
303 int i, ubi_num = -ENODEV;
305 spin_lock(&ubi_devices_lock);
306 for (i = 0; i < UBI_MAX_DEVICES; i++) {
307 struct ubi_device *ubi = ubi_devices[i];
309 if (ubi && MAJOR(ubi->cdev.dev) == major) {
310 ubi_num = ubi->ubi_num;
314 spin_unlock(&ubi_devices_lock);
319 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
320 static ssize_t dev_attribute_show(struct device *dev,
321 struct device_attribute *attr, char *buf)
324 struct ubi_device *ubi;
327 * The below code looks weird, but it actually makes sense. We get the
328 * UBI device reference from the contained 'struct ubi_device'. But it
329 * is unclear if the device was removed or not yet. Indeed, if the
330 * device was removed before we increased its reference count,
331 * 'ubi_get_device()' will return -ENODEV and we fail.
333 * Remember, 'struct ubi_device' is freed in the release function, so
334 * we still can use 'ubi->ubi_num'.
336 ubi = container_of(dev, struct ubi_device, dev);
337 ubi = ubi_get_device(ubi->ubi_num);
341 if (attr == &dev_eraseblock_size)
342 ret = sprintf(buf, "%d\n", ubi->leb_size);
343 else if (attr == &dev_avail_eraseblocks)
344 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
345 else if (attr == &dev_total_eraseblocks)
346 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
347 else if (attr == &dev_volumes_count)
348 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
349 else if (attr == &dev_max_ec)
350 ret = sprintf(buf, "%d\n", ubi->max_ec);
351 else if (attr == &dev_reserved_for_bad)
352 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
353 else if (attr == &dev_bad_peb_count)
354 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
355 else if (attr == &dev_max_vol_count)
356 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
357 else if (attr == &dev_min_io_size)
358 ret = sprintf(buf, "%d\n", ubi->min_io_size);
359 else if (attr == &dev_bgt_enabled)
360 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
361 else if (attr == &dev_mtd_num)
362 ret = sprintf(buf, "%d\n", ubi->mtd->index);
370 static void dev_release(struct device *dev)
372 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
378 * ubi_sysfs_init - initialize sysfs for an UBI device.
379 * @ubi: UBI device description object
380 * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
383 * This function returns zero in case of success and a negative error code in
386 static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
390 ubi->dev.release = dev_release;
391 ubi->dev.devt = ubi->cdev.dev;
392 ubi->dev.class = ubi_class;
393 dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
394 err = device_register(&ubi->dev);
399 err = device_create_file(&ubi->dev, &dev_eraseblock_size);
402 err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
405 err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
408 err = device_create_file(&ubi->dev, &dev_volumes_count);
411 err = device_create_file(&ubi->dev, &dev_max_ec);
414 err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
417 err = device_create_file(&ubi->dev, &dev_bad_peb_count);
420 err = device_create_file(&ubi->dev, &dev_max_vol_count);
423 err = device_create_file(&ubi->dev, &dev_min_io_size);
426 err = device_create_file(&ubi->dev, &dev_bgt_enabled);
429 err = device_create_file(&ubi->dev, &dev_mtd_num);
434 * ubi_sysfs_close - close sysfs for an UBI device.
435 * @ubi: UBI device description object
437 static void ubi_sysfs_close(struct ubi_device *ubi)
439 device_remove_file(&ubi->dev, &dev_mtd_num);
440 device_remove_file(&ubi->dev, &dev_bgt_enabled);
441 device_remove_file(&ubi->dev, &dev_min_io_size);
442 device_remove_file(&ubi->dev, &dev_max_vol_count);
443 device_remove_file(&ubi->dev, &dev_bad_peb_count);
444 device_remove_file(&ubi->dev, &dev_reserved_for_bad);
445 device_remove_file(&ubi->dev, &dev_max_ec);
446 device_remove_file(&ubi->dev, &dev_volumes_count);
447 device_remove_file(&ubi->dev, &dev_total_eraseblocks);
448 device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
449 device_remove_file(&ubi->dev, &dev_eraseblock_size);
450 device_unregister(&ubi->dev);
454 * kill_volumes - destroy all user volumes.
455 * @ubi: UBI device description object
457 static void kill_volumes(struct ubi_device *ubi)
461 for (i = 0; i < ubi->vtbl_slots; i++)
463 ubi_free_volume(ubi, ubi->volumes[i]);
467 * uif_init - initialize user interfaces for an UBI device.
468 * @ubi: UBI device description object
469 * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
470 * taken, otherwise set to %0
472 * This function initializes various user interfaces for an UBI device. If the
473 * initialization fails at an early stage, this function frees all the
474 * resources it allocated, returns an error, and @ref is set to %0. However,
475 * if the initialization fails after the UBI device was registered in the
476 * driver core subsystem, this function takes a reference to @ubi->dev, because
477 * otherwise the release function ('dev_release()') would free whole @ubi
478 * object. The @ref argument is set to %1 in this case. The caller has to put
481 * This function returns zero in case of success and a negative error code in
484 static int uif_init(struct ubi_device *ubi, int *ref)
490 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
493 * Major numbers for the UBI character devices are allocated
494 * dynamically. Major numbers of volume character devices are
495 * equivalent to ones of the corresponding UBI character device. Minor
496 * numbers of UBI character devices are 0, while minor numbers of
497 * volume character devices start from 1. Thus, we allocate one major
498 * number and ubi->vtbl_slots + 1 minor numbers.
500 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
502 ubi_err("cannot register UBI character devices");
506 ubi_assert(MINOR(dev) == 0);
507 cdev_init(&ubi->cdev, &ubi_cdev_operations);
508 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
509 ubi->cdev.owner = THIS_MODULE;
511 err = cdev_add(&ubi->cdev, dev, 1);
513 ubi_err("cannot add character device");
517 err = ubi_sysfs_init(ubi, ref);
521 for (i = 0; i < ubi->vtbl_slots; i++)
522 if (ubi->volumes[i]) {
523 err = ubi_add_volume(ubi, ubi->volumes[i]);
525 ubi_err("cannot add volume %d", i);
536 get_device(&ubi->dev);
537 ubi_sysfs_close(ubi);
538 cdev_del(&ubi->cdev);
540 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
541 ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
546 * uif_close - close user interfaces for an UBI device.
547 * @ubi: UBI device description object
549 * Note, since this function un-registers UBI volume device objects (@vol->dev),
550 * the memory allocated voe the volumes is freed as well (in the release
553 static void uif_close(struct ubi_device *ubi)
556 ubi_sysfs_close(ubi);
557 cdev_del(&ubi->cdev);
558 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
562 * ubi_free_internal_volumes - free internal volumes.
563 * @ubi: UBI device description object
565 void ubi_free_internal_volumes(struct ubi_device *ubi)
569 for (i = ubi->vtbl_slots;
570 i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
571 kfree(ubi->volumes[i]->eba_tbl);
572 kfree(ubi->volumes[i]);
576 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
578 int limit, device_pebs;
579 uint64_t device_size;
581 if (!max_beb_per1024)
585 * Here we are using size of the entire flash chip and
586 * not just the MTD partition size because the maximum
587 * number of bad eraseblocks is a percentage of the
588 * whole device and bad eraseblocks are not fairly
589 * distributed over the flash chip. So the worst case
590 * is that all the bad eraseblocks of the chip are in
591 * the MTD partition we are attaching (ubi->mtd).
593 device_size = mtd_get_device_size(ubi->mtd);
594 device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
595 limit = mult_frac(device_pebs, max_beb_per1024, 1024);
598 if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
605 * io_init - initialize I/O sub-system for a given UBI device.
606 * @ubi: UBI device description object
607 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
609 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
611 * o EC header is always at offset zero - this cannot be changed;
612 * o VID header starts just after the EC header at the closest address
613 * aligned to @io->hdrs_min_io_size;
614 * o data starts just after the VID header at the closest address aligned to
617 * This function returns zero in case of success and a negative error code in
620 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
622 if (ubi->mtd->numeraseregions != 0) {
624 * Some flashes have several erase regions. Different regions
625 * may have different eraseblock size and other
626 * characteristics. It looks like mostly multi-region flashes
627 * have one "main" region and one or more small regions to
628 * store boot loader code or boot parameters or whatever. I
629 * guess we should just pick the largest region. But this is
632 ubi_err("multiple regions, not implemented");
636 if (ubi->vid_hdr_offset < 0)
640 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
641 * physical eraseblocks maximum.
644 ubi->peb_size = ubi->mtd->erasesize;
645 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
646 ubi->flash_size = ubi->mtd->size;
648 if (mtd_can_have_bb(ubi->mtd)) {
649 ubi->bad_allowed = 1;
650 ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
653 if (ubi->mtd->type == MTD_NORFLASH) {
654 ubi_assert(ubi->mtd->writesize == 1);
658 ubi->min_io_size = ubi->mtd->writesize;
659 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
662 * Make sure minimal I/O unit is power of 2. Note, there is no
663 * fundamental reason for this assumption. It is just an optimization
664 * which allows us to avoid costly division operations.
666 if (!is_power_of_2(ubi->min_io_size)) {
667 ubi_err("min. I/O unit (%d) is not power of 2",
672 ubi_assert(ubi->hdrs_min_io_size > 0);
673 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
674 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
676 ubi->max_write_size = ubi->mtd->writebufsize;
678 * Maximum write size has to be greater or equivalent to min. I/O
679 * size, and be multiple of min. I/O size.
681 if (ubi->max_write_size < ubi->min_io_size ||
682 ubi->max_write_size % ubi->min_io_size ||
683 !is_power_of_2(ubi->max_write_size)) {
684 ubi_err("bad write buffer size %d for %d min. I/O unit",
685 ubi->max_write_size, ubi->min_io_size);
689 /* Calculate default aligned sizes of EC and VID headers */
690 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
691 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
693 dbg_msg("min_io_size %d", ubi->min_io_size);
694 dbg_msg("max_write_size %d", ubi->max_write_size);
695 dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
696 dbg_msg("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
697 dbg_msg("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
699 if (ubi->vid_hdr_offset == 0)
701 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
704 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
705 ~(ubi->hdrs_min_io_size - 1);
706 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
707 ubi->vid_hdr_aloffset;
710 /* Similar for the data offset */
711 ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
712 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
714 dbg_msg("vid_hdr_offset %d", ubi->vid_hdr_offset);
715 dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
716 dbg_msg("vid_hdr_shift %d", ubi->vid_hdr_shift);
717 dbg_msg("leb_start %d", ubi->leb_start);
719 /* The shift must be aligned to 32-bit boundary */
720 if (ubi->vid_hdr_shift % 4) {
721 ubi_err("unaligned VID header shift %d",
727 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
728 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
729 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
730 ubi->leb_start & (ubi->min_io_size - 1)) {
731 ubi_err("bad VID header (%d) or data offsets (%d)",
732 ubi->vid_hdr_offset, ubi->leb_start);
737 * Set maximum amount of physical erroneous eraseblocks to be 10%.
738 * Erroneous PEB are those which have read errors.
740 ubi->max_erroneous = ubi->peb_count / 10;
741 if (ubi->max_erroneous < 16)
742 ubi->max_erroneous = 16;
743 dbg_msg("max_erroneous %d", ubi->max_erroneous);
746 * It may happen that EC and VID headers are situated in one minimal
747 * I/O unit. In this case we can only accept this UBI image in
750 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
751 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
752 "switch to read-only mode");
756 ubi->leb_size = ubi->peb_size - ubi->leb_start;
758 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
759 ubi_msg("MTD device %d is write-protected, attach in "
760 "read-only mode", ubi->mtd->index);
764 ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
765 ubi->peb_size, ubi->peb_size >> 10);
766 ubi_msg("logical eraseblock size: %d bytes", ubi->leb_size);
767 ubi_msg("smallest flash I/O unit: %d", ubi->min_io_size);
768 if (ubi->hdrs_min_io_size != ubi->min_io_size)
769 ubi_msg("sub-page size: %d",
770 ubi->hdrs_min_io_size);
771 ubi_msg("VID header offset: %d (aligned %d)",
772 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
773 ubi_msg("data offset: %d", ubi->leb_start);
776 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
777 * unfortunately, MTD does not provide this information. We should loop
778 * over all physical eraseblocks and invoke mtd->block_is_bad() for
779 * each physical eraseblock. So, we leave @ubi->bad_peb_count
780 * uninitialized so far.
787 * autoresize - re-size the volume which has the "auto-resize" flag set.
788 * @ubi: UBI device description object
789 * @vol_id: ID of the volume to re-size
791 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
792 * the volume table to the largest possible size. See comments in ubi-header.h
793 * for more description of the flag. Returns zero in case of success and a
794 * negative error code in case of failure.
796 static int autoresize(struct ubi_device *ubi, int vol_id)
798 struct ubi_volume_desc desc;
799 struct ubi_volume *vol = ubi->volumes[vol_id];
800 int err, old_reserved_pebs = vol->reserved_pebs;
803 ubi_warn("skip auto-resize because of R/O mode");
808 * Clear the auto-resize flag in the volume in-memory copy of the
809 * volume table, and 'ubi_resize_volume()' will propagate this change
812 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
814 if (ubi->avail_pebs == 0) {
815 struct ubi_vtbl_record vtbl_rec;
818 * No available PEBs to re-size the volume, clear the flag on
821 memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
822 sizeof(struct ubi_vtbl_record));
823 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
825 ubi_err("cannot clean auto-resize flag for volume %d",
829 err = ubi_resize_volume(&desc,
830 old_reserved_pebs + ubi->avail_pebs);
832 ubi_err("cannot auto-resize volume %d", vol_id);
838 ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
839 vol->name, old_reserved_pebs, vol->reserved_pebs);
844 * ubi_attach_mtd_dev - attach an MTD device.
845 * @mtd: MTD device description object
846 * @ubi_num: number to assign to the new UBI device
847 * @vid_hdr_offset: VID header offset
848 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
850 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
851 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
852 * which case this function finds a vacant device number and assigns it
853 * automatically. Returns the new UBI device number in case of success and a
854 * negative error code in case of failure.
856 * Note, the invocations of this function has to be serialized by the
857 * @ubi_devices_mutex.
859 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
860 int vid_hdr_offset, int max_beb_per1024)
862 struct ubi_device *ubi;
865 if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
868 if (!max_beb_per1024)
869 max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
872 * Check if we already have the same MTD device attached.
874 * Note, this function assumes that UBI devices creations and deletions
875 * are serialized, so it does not take the &ubi_devices_lock.
877 for (i = 0; i < UBI_MAX_DEVICES; i++) {
878 ubi = ubi_devices[i];
879 if (ubi && mtd->index == ubi->mtd->index) {
880 ubi_err("mtd%d is already attached to ubi%d",
887 * Make sure this MTD device is not emulated on top of an UBI volume
888 * already. Well, generally this recursion works fine, but there are
889 * different problems like the UBI module takes a reference to itself
890 * by attaching (and thus, opening) the emulated MTD device. This
891 * results in inability to unload the module. And in general it makes
892 * no sense to attach emulated MTD devices, so we prohibit this.
894 if (mtd->type == MTD_UBIVOLUME) {
895 ubi_err("refuse attaching mtd%d - it is already emulated on "
896 "top of UBI", mtd->index);
900 if (ubi_num == UBI_DEV_NUM_AUTO) {
901 /* Search for an empty slot in the @ubi_devices array */
902 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
903 if (!ubi_devices[ubi_num])
905 if (ubi_num == UBI_MAX_DEVICES) {
906 ubi_err("only %d UBI devices may be created",
911 if (ubi_num >= UBI_MAX_DEVICES)
914 /* Make sure ubi_num is not busy */
915 if (ubi_devices[ubi_num]) {
916 ubi_err("ubi%d already exists", ubi_num);
921 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
926 ubi->ubi_num = ubi_num;
927 ubi->vid_hdr_offset = vid_hdr_offset;
928 ubi->autoresize_vol_id = -1;
930 mutex_init(&ubi->buf_mutex);
931 mutex_init(&ubi->ckvol_mutex);
932 mutex_init(&ubi->device_mutex);
933 spin_lock_init(&ubi->volumes_lock);
935 ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
936 dbg_msg("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
937 dbg_msg("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
939 err = io_init(ubi, max_beb_per1024);
944 ubi->peb_buf = vmalloc(ubi->peb_size);
948 err = ubi_debugging_init_dev(ubi);
952 err = ubi_attach(ubi);
954 ubi_err("failed to attach mtd%d, error %d", mtd->index, err);
958 if (ubi->autoresize_vol_id != -1) {
959 err = autoresize(ubi, ubi->autoresize_vol_id);
964 err = uif_init(ubi, &ref);
968 err = ubi_debugfs_init_dev(ubi);
972 ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
973 if (IS_ERR(ubi->bgt_thread)) {
974 err = PTR_ERR(ubi->bgt_thread);
975 ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
980 ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
981 ubi_msg("MTD device name: \"%s\"", mtd->name);
982 ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20);
983 ubi_msg("number of good PEBs: %d", ubi->good_peb_count);
984 ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count);
985 ubi_msg("number of corrupted PEBs: %d", ubi->corr_peb_count);
986 ubi_msg("max. allowed volumes: %d", ubi->vtbl_slots);
987 ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD);
988 ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
989 ubi_msg("number of user volumes: %d",
990 ubi->vol_count - UBI_INT_VOL_COUNT);
991 ubi_msg("available PEBs: %d", ubi->avail_pebs);
992 ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
993 ubi_msg("number of PEBs reserved for bad PEB handling: %d",
995 ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
996 ubi_msg("image sequence number: %u", ubi->image_seq);
999 * The below lock makes sure we do not race with 'ubi_thread()' which
1000 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
1002 spin_lock(&ubi->wl_lock);
1003 ubi->thread_enabled = 1;
1004 wake_up_process(ubi->bgt_thread);
1005 spin_unlock(&ubi->wl_lock);
1007 ubi_devices[ubi_num] = ubi;
1008 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1012 ubi_debugfs_exit_dev(ubi);
1014 get_device(&ubi->dev);
1019 ubi_free_internal_volumes(ubi);
1022 ubi_debugging_exit_dev(ubi);
1024 vfree(ubi->peb_buf);
1026 put_device(&ubi->dev);
1033 * ubi_detach_mtd_dev - detach an MTD device.
1034 * @ubi_num: UBI device number to detach from
1035 * @anyway: detach MTD even if device reference count is not zero
1037 * This function destroys an UBI device number @ubi_num and detaches the
1038 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1039 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1042 * Note, the invocations of this function has to be serialized by the
1043 * @ubi_devices_mutex.
1045 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1047 struct ubi_device *ubi;
1049 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1052 ubi = ubi_get_device(ubi_num);
1056 spin_lock(&ubi_devices_lock);
1057 put_device(&ubi->dev);
1058 ubi->ref_count -= 1;
1059 if (ubi->ref_count) {
1061 spin_unlock(&ubi_devices_lock);
1064 /* This may only happen if there is a bug */
1065 ubi_err("%s reference count %d, destroy anyway",
1066 ubi->ubi_name, ubi->ref_count);
1068 ubi_devices[ubi_num] = NULL;
1069 spin_unlock(&ubi_devices_lock);
1071 ubi_assert(ubi_num == ubi->ubi_num);
1072 ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1073 dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
1076 * Before freeing anything, we have to stop the background thread to
1077 * prevent it from doing anything on this device while we are freeing.
1079 if (ubi->bgt_thread)
1080 kthread_stop(ubi->bgt_thread);
1083 * Get a reference to the device in order to prevent 'dev_release()'
1084 * from freeing the @ubi object.
1086 get_device(&ubi->dev);
1088 ubi_debugfs_exit_dev(ubi);
1091 ubi_free_internal_volumes(ubi);
1093 put_mtd_device(ubi->mtd);
1094 ubi_debugging_exit_dev(ubi);
1095 vfree(ubi->peb_buf);
1096 ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
1097 put_device(&ubi->dev);
1102 * open_mtd_by_chdev - open an MTD device by its character device node path.
1103 * @mtd_dev: MTD character device node path
1105 * This helper function opens an MTD device by its character node device path.
1106 * Returns MTD device description object in case of success and a negative
1107 * error code in case of failure.
1109 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1111 int err, major, minor, mode;
1114 /* Probably this is an MTD character device node path */
1115 err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1117 return ERR_PTR(err);
1119 /* MTD device number is defined by the major / minor numbers */
1120 major = imajor(path.dentry->d_inode);
1121 minor = iminor(path.dentry->d_inode);
1122 mode = path.dentry->d_inode->i_mode;
1124 if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))
1125 return ERR_PTR(-EINVAL);
1129 * Just do not think the "/dev/mtdrX" devices support is need,
1130 * so do not support them to avoid doing extra work.
1132 return ERR_PTR(-EINVAL);
1134 return get_mtd_device(NULL, minor / 2);
1138 * open_mtd_device - open MTD device by name, character device path, or number.
1139 * @mtd_dev: name, character device node path, or MTD device device number
1141 * This function tries to open and MTD device described by @mtd_dev string,
1142 * which is first treated as ASCII MTD device number, and if it is not true, it
1143 * is treated as MTD device name, and if that is also not true, it is treated
1144 * as MTD character device node path. Returns MTD device description object in
1145 * case of success and a negative error code in case of failure.
1147 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1149 struct mtd_info *mtd;
1153 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1154 if (*endp != '\0' || mtd_dev == endp) {
1156 * This does not look like an ASCII integer, probably this is
1159 mtd = get_mtd_device_nm(mtd_dev);
1160 if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV)
1161 /* Probably this is an MTD character device node path */
1162 mtd = open_mtd_by_chdev(mtd_dev);
1164 mtd = get_mtd_device(NULL, mtd_num);
1169 static int __init ubi_init(void)
1173 /* Ensure that EC and VID headers have correct size */
1174 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1175 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1177 if (mtd_devs > UBI_MAX_DEVICES) {
1178 ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
1182 /* Create base sysfs directory and sysfs files */
1183 ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
1184 if (IS_ERR(ubi_class)) {
1185 err = PTR_ERR(ubi_class);
1186 ubi_err("cannot create UBI class");
1190 err = class_create_file(ubi_class, &ubi_version);
1192 ubi_err("cannot create sysfs file");
1196 err = misc_register(&ubi_ctrl_cdev);
1198 ubi_err("cannot register device");
1202 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1203 sizeof(struct ubi_wl_entry),
1205 if (!ubi_wl_entry_slab)
1208 err = ubi_debugfs_init();
1213 /* Attach MTD devices */
1214 for (i = 0; i < mtd_devs; i++) {
1215 struct mtd_dev_param *p = &mtd_dev_param[i];
1216 struct mtd_info *mtd;
1220 mtd = open_mtd_device(p->name);
1226 mutex_lock(&ubi_devices_mutex);
1227 err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
1228 p->vid_hdr_offs, p->max_beb_per1024);
1229 mutex_unlock(&ubi_devices_mutex);
1231 ubi_err("cannot attach mtd%d", mtd->index);
1232 put_mtd_device(mtd);
1235 * Originally UBI stopped initializing on any error.
1236 * However, later on it was found out that this
1237 * behavior is not very good when UBI is compiled into
1238 * the kernel and the MTD devices to attach are passed
1239 * through the command line. Indeed, UBI failure
1240 * stopped whole boot sequence.
1242 * To fix this, we changed the behavior for the
1243 * non-module case, but preserved the old behavior for
1244 * the module case, just for compatibility. This is a
1245 * little inconsistent, though.
1247 if (ubi_is_module())
1255 for (k = 0; k < i; k++)
1256 if (ubi_devices[k]) {
1257 mutex_lock(&ubi_devices_mutex);
1258 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1259 mutex_unlock(&ubi_devices_mutex);
1263 kmem_cache_destroy(ubi_wl_entry_slab);
1265 misc_deregister(&ubi_ctrl_cdev);
1267 class_remove_file(ubi_class, &ubi_version);
1269 class_destroy(ubi_class);
1271 ubi_err("UBI error: cannot initialize UBI, error %d", err);
1274 module_init(ubi_init);
1276 static void __exit ubi_exit(void)
1280 for (i = 0; i < UBI_MAX_DEVICES; i++)
1281 if (ubi_devices[i]) {
1282 mutex_lock(&ubi_devices_mutex);
1283 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1284 mutex_unlock(&ubi_devices_mutex);
1287 kmem_cache_destroy(ubi_wl_entry_slab);
1288 misc_deregister(&ubi_ctrl_cdev);
1289 class_remove_file(ubi_class, &ubi_version);
1290 class_destroy(ubi_class);
1292 module_exit(ubi_exit);
1295 * bytes_str_to_int - convert a number of bytes string into an integer.
1296 * @str: the string to convert
1298 * This function returns positive resulting integer in case of success and a
1299 * negative error code in case of failure.
1301 static int __init bytes_str_to_int(const char *str)
1304 unsigned long result;
1306 result = simple_strtoul(str, &endp, 0);
1307 if (str == endp || result >= INT_MAX) {
1308 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1320 if (endp[1] == 'i' && endp[2] == 'B')
1325 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1334 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1335 * @val: the parameter value to parse
1338 * This function returns zero in case of success and a negative error code in
1341 static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1344 struct mtd_dev_param *p;
1345 char buf[MTD_PARAM_LEN_MAX];
1346 char *pbuf = &buf[0];
1347 char *tokens[MTD_PARAM_MAX_COUNT];
1352 if (mtd_devs == UBI_MAX_DEVICES) {
1353 printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
1358 len = strnlen(val, MTD_PARAM_LEN_MAX);
1359 if (len == MTD_PARAM_LEN_MAX) {
1360 printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
1361 "max. is %d\n", val, MTD_PARAM_LEN_MAX);
1366 printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
1373 /* Get rid of the final newline */
1374 if (buf[len - 1] == '\n')
1375 buf[len - 1] = '\0';
1377 for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1378 tokens[i] = strsep(&pbuf, ",");
1381 printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
1386 p = &mtd_dev_param[mtd_devs];
1387 strcpy(&p->name[0], tokens[0]);
1390 p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
1392 if (p->vid_hdr_offs < 0)
1393 return p->vid_hdr_offs;
1396 int err = kstrtoint(tokens[2], 10, &p->max_beb_per1024);
1399 printk(KERN_ERR "UBI error: bad value for "
1400 "max_beb_per1024 parameter: %s", tokens[2]);
1409 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1410 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024]].\n"
1411 "Multiple \"mtd\" parameters may be specified.\n"
1412 "MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
1413 "Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
1414 "Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
1415 __stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
1417 "Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
1418 "Example 2: mtd=content,1984 mtd=4 - attach MTD device with name \"content\" using VID header offset 1984, and MTD device number 4 with default VID header offset.\n"
1419 "Example 3: mtd=/dev/mtd1,0,25 - attach MTD device /dev/mtd1 using default VID header offset and reserve 25*nand_size_in_blocks/1024 erase blocks for bad block handling.\n"
1420 "\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
1422 MODULE_VERSION(__stringify(UBI_VERSION));
1423 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1424 MODULE_AUTHOR("Artem Bityutskiy");
1425 MODULE_LICENSE("GPL");