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.
37 #include <linux/err.h>
38 #include <linux/module.h>
39 #include <linux/moduleparam.h>
40 #include <linux/stringify.h>
41 #include <linux/stat.h>
42 #include <linux/miscdevice.h>
43 #include <linux/log2.h>
44 #include <linux/kthread.h>
46 #include <ubi_uboot.h>
49 #if (CONFIG_SYS_MALLOC_LEN < (512 << 10))
50 #error Malloc area too small for UBI, increase CONFIG_SYS_MALLOC_LEN to >= 512k
53 /* Maximum length of the 'mtd=' parameter */
54 #define MTD_PARAM_LEN_MAX 64
57 * struct mtd_dev_param - MTD device parameter description data structure.
58 * @name: MTD device name or number string
59 * @vid_hdr_offs: VID header offset
63 char name
[MTD_PARAM_LEN_MAX
];
67 /* Numbers of elements set in the @mtd_dev_param array */
68 static int mtd_devs
= 0;
70 /* MTD devices specification parameters */
71 static struct mtd_dev_param mtd_dev_param
[UBI_MAX_DEVICES
];
73 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
74 struct class *ubi_class
;
77 /* Slab cache for wear-leveling entries */
78 struct kmem_cache
*ubi_wl_entry_slab
;
80 /* UBI control character device */
81 static struct miscdevice ubi_ctrl_cdev
= {
82 .minor
= MISC_DYNAMIC_MINOR
,
84 .fops
= &ubi_ctrl_cdev_operations
,
88 /* All UBI devices in system */
89 struct ubi_device
*ubi_devices
[UBI_MAX_DEVICES
];
92 /* Serializes UBI devices creations and removals */
93 DEFINE_MUTEX(ubi_devices_mutex
);
95 /* Protects @ubi_devices and @ubi->ref_count */
96 static DEFINE_SPINLOCK(ubi_devices_lock
);
98 /* "Show" method for files in '/<sysfs>/class/ubi/' */
99 static ssize_t
ubi_version_show(struct class *class, char *buf
)
101 return sprintf(buf
, "%d\n", UBI_VERSION
);
104 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
105 static struct class_attribute ubi_version
=
106 __ATTR(version
, S_IRUGO
, ubi_version_show
, NULL
);
108 static ssize_t
dev_attribute_show(struct device
*dev
,
109 struct device_attribute
*attr
, char *buf
);
111 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
112 static struct device_attribute dev_eraseblock_size
=
113 __ATTR(eraseblock_size
, S_IRUGO
, dev_attribute_show
, NULL
);
114 static struct device_attribute dev_avail_eraseblocks
=
115 __ATTR(avail_eraseblocks
, S_IRUGO
, dev_attribute_show
, NULL
);
116 static struct device_attribute dev_total_eraseblocks
=
117 __ATTR(total_eraseblocks
, S_IRUGO
, dev_attribute_show
, NULL
);
118 static struct device_attribute dev_volumes_count
=
119 __ATTR(volumes_count
, S_IRUGO
, dev_attribute_show
, NULL
);
120 static struct device_attribute dev_max_ec
=
121 __ATTR(max_ec
, S_IRUGO
, dev_attribute_show
, NULL
);
122 static struct device_attribute dev_reserved_for_bad
=
123 __ATTR(reserved_for_bad
, S_IRUGO
, dev_attribute_show
, NULL
);
124 static struct device_attribute dev_bad_peb_count
=
125 __ATTR(bad_peb_count
, S_IRUGO
, dev_attribute_show
, NULL
);
126 static struct device_attribute dev_max_vol_count
=
127 __ATTR(max_vol_count
, S_IRUGO
, dev_attribute_show
, NULL
);
128 static struct device_attribute dev_min_io_size
=
129 __ATTR(min_io_size
, S_IRUGO
, dev_attribute_show
, NULL
);
130 static struct device_attribute dev_bgt_enabled
=
131 __ATTR(bgt_enabled
, S_IRUGO
, dev_attribute_show
, NULL
);
132 static struct device_attribute dev_mtd_num
=
133 __ATTR(mtd_num
, S_IRUGO
, dev_attribute_show
, NULL
);
137 * ubi_get_device - get UBI device.
138 * @ubi_num: UBI device number
140 * This function returns UBI device description object for UBI device number
141 * @ubi_num, or %NULL if the device does not exist. This function increases the
142 * device reference count to prevent removal of the device. In other words, the
143 * device cannot be removed if its reference count is not zero.
145 struct ubi_device
*ubi_get_device(int ubi_num
)
147 struct ubi_device
*ubi
;
149 spin_lock(&ubi_devices_lock
);
150 ubi
= ubi_devices
[ubi_num
];
152 ubi_assert(ubi
->ref_count
>= 0);
154 get_device(&ubi
->dev
);
156 spin_unlock(&ubi_devices_lock
);
162 * ubi_put_device - drop an UBI device reference.
163 * @ubi: UBI device description object
165 void ubi_put_device(struct ubi_device
*ubi
)
167 spin_lock(&ubi_devices_lock
);
169 put_device(&ubi
->dev
);
170 spin_unlock(&ubi_devices_lock
);
174 * ubi_get_by_major - get UBI device description object by character device
176 * @major: major number
178 * This function is similar to 'ubi_get_device()', but it searches the device
179 * by its major number.
181 struct ubi_device
*ubi_get_by_major(int major
)
184 struct ubi_device
*ubi
;
186 spin_lock(&ubi_devices_lock
);
187 for (i
= 0; i
< UBI_MAX_DEVICES
; i
++) {
188 ubi
= ubi_devices
[i
];
189 if (ubi
&& MAJOR(ubi
->cdev
.dev
) == major
) {
190 ubi_assert(ubi
->ref_count
>= 0);
192 get_device(&ubi
->dev
);
193 spin_unlock(&ubi_devices_lock
);
197 spin_unlock(&ubi_devices_lock
);
203 * ubi_major2num - get UBI device number by character device major number.
204 * @major: major number
206 * This function searches UBI device number object by its major number. If UBI
207 * device was not found, this function returns -ENODEV, otherwise the UBI device
208 * number is returned.
210 int ubi_major2num(int major
)
212 int i
, ubi_num
= -ENODEV
;
214 spin_lock(&ubi_devices_lock
);
215 for (i
= 0; i
< UBI_MAX_DEVICES
; i
++) {
216 struct ubi_device
*ubi
= ubi_devices
[i
];
218 if (ubi
&& MAJOR(ubi
->cdev
.dev
) == major
) {
219 ubi_num
= ubi
->ubi_num
;
223 spin_unlock(&ubi_devices_lock
);
229 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
230 static ssize_t
dev_attribute_show(struct device
*dev
,
231 struct device_attribute
*attr
, char *buf
)
234 struct ubi_device
*ubi
;
237 * The below code looks weird, but it actually makes sense. We get the
238 * UBI device reference from the contained 'struct ubi_device'. But it
239 * is unclear if the device was removed or not yet. Indeed, if the
240 * device was removed before we increased its reference count,
241 * 'ubi_get_device()' will return -ENODEV and we fail.
243 * Remember, 'struct ubi_device' is freed in the release function, so
244 * we still can use 'ubi->ubi_num'.
246 ubi
= container_of(dev
, struct ubi_device
, dev
);
247 ubi
= ubi_get_device(ubi
->ubi_num
);
251 if (attr
== &dev_eraseblock_size
)
252 ret
= sprintf(buf
, "%d\n", ubi
->leb_size
);
253 else if (attr
== &dev_avail_eraseblocks
)
254 ret
= sprintf(buf
, "%d\n", ubi
->avail_pebs
);
255 else if (attr
== &dev_total_eraseblocks
)
256 ret
= sprintf(buf
, "%d\n", ubi
->good_peb_count
);
257 else if (attr
== &dev_volumes_count
)
258 ret
= sprintf(buf
, "%d\n", ubi
->vol_count
- UBI_INT_VOL_COUNT
);
259 else if (attr
== &dev_max_ec
)
260 ret
= sprintf(buf
, "%d\n", ubi
->max_ec
);
261 else if (attr
== &dev_reserved_for_bad
)
262 ret
= sprintf(buf
, "%d\n", ubi
->beb_rsvd_pebs
);
263 else if (attr
== &dev_bad_peb_count
)
264 ret
= sprintf(buf
, "%d\n", ubi
->bad_peb_count
);
265 else if (attr
== &dev_max_vol_count
)
266 ret
= sprintf(buf
, "%d\n", ubi
->vtbl_slots
);
267 else if (attr
== &dev_min_io_size
)
268 ret
= sprintf(buf
, "%d\n", ubi
->min_io_size
);
269 else if (attr
== &dev_bgt_enabled
)
270 ret
= sprintf(buf
, "%d\n", ubi
->thread_enabled
);
271 else if (attr
== &dev_mtd_num
)
272 ret
= sprintf(buf
, "%d\n", ubi
->mtd
->index
);
280 /* Fake "release" method for UBI devices */
281 static void dev_release(struct device
*dev
) { }
284 * ubi_sysfs_init - initialize sysfs for an UBI device.
285 * @ubi: UBI device description object
287 * This function returns zero in case of success and a negative error code in
290 static int ubi_sysfs_init(struct ubi_device
*ubi
)
294 ubi
->dev
.release
= dev_release
;
295 ubi
->dev
.devt
= ubi
->cdev
.dev
;
296 ubi
->dev
.class = ubi_class
;
297 sprintf(&ubi
->dev
.bus_id
[0], UBI_NAME_STR
"%d", ubi
->ubi_num
);
298 err
= device_register(&ubi
->dev
);
302 err
= device_create_file(&ubi
->dev
, &dev_eraseblock_size
);
305 err
= device_create_file(&ubi
->dev
, &dev_avail_eraseblocks
);
308 err
= device_create_file(&ubi
->dev
, &dev_total_eraseblocks
);
311 err
= device_create_file(&ubi
->dev
, &dev_volumes_count
);
314 err
= device_create_file(&ubi
->dev
, &dev_max_ec
);
317 err
= device_create_file(&ubi
->dev
, &dev_reserved_for_bad
);
320 err
= device_create_file(&ubi
->dev
, &dev_bad_peb_count
);
323 err
= device_create_file(&ubi
->dev
, &dev_max_vol_count
);
326 err
= device_create_file(&ubi
->dev
, &dev_min_io_size
);
329 err
= device_create_file(&ubi
->dev
, &dev_bgt_enabled
);
332 err
= device_create_file(&ubi
->dev
, &dev_mtd_num
);
337 * ubi_sysfs_close - close sysfs for an UBI device.
338 * @ubi: UBI device description object
340 static void ubi_sysfs_close(struct ubi_device
*ubi
)
342 device_remove_file(&ubi
->dev
, &dev_mtd_num
);
343 device_remove_file(&ubi
->dev
, &dev_bgt_enabled
);
344 device_remove_file(&ubi
->dev
, &dev_min_io_size
);
345 device_remove_file(&ubi
->dev
, &dev_max_vol_count
);
346 device_remove_file(&ubi
->dev
, &dev_bad_peb_count
);
347 device_remove_file(&ubi
->dev
, &dev_reserved_for_bad
);
348 device_remove_file(&ubi
->dev
, &dev_max_ec
);
349 device_remove_file(&ubi
->dev
, &dev_volumes_count
);
350 device_remove_file(&ubi
->dev
, &dev_total_eraseblocks
);
351 device_remove_file(&ubi
->dev
, &dev_avail_eraseblocks
);
352 device_remove_file(&ubi
->dev
, &dev_eraseblock_size
);
353 device_unregister(&ubi
->dev
);
358 * kill_volumes - destroy all volumes.
359 * @ubi: UBI device description object
361 static void kill_volumes(struct ubi_device
*ubi
)
365 for (i
= 0; i
< ubi
->vtbl_slots
; i
++)
367 ubi_free_volume(ubi
, ubi
->volumes
[i
]);
371 * uif_init - initialize user interfaces for an UBI device.
372 * @ubi: UBI device description object
374 * This function returns zero in case of success and a negative error code in
377 static int uif_init(struct ubi_device
*ubi
)
384 sprintf(ubi
->ubi_name
, UBI_NAME_STR
"%d", ubi
->ubi_num
);
387 * Major numbers for the UBI character devices are allocated
388 * dynamically. Major numbers of volume character devices are
389 * equivalent to ones of the corresponding UBI character device. Minor
390 * numbers of UBI character devices are 0, while minor numbers of
391 * volume character devices start from 1. Thus, we allocate one major
392 * number and ubi->vtbl_slots + 1 minor numbers.
394 err
= alloc_chrdev_region(&dev
, 0, ubi
->vtbl_slots
+ 1, ubi
->ubi_name
);
396 ubi_err("cannot register UBI character devices");
400 ubi_assert(MINOR(dev
) == 0);
401 cdev_init(&ubi
->cdev
, &ubi_cdev_operations
);
402 dbg_msg("%s major is %u", ubi
->ubi_name
, MAJOR(dev
));
403 ubi
->cdev
.owner
= THIS_MODULE
;
405 err
= cdev_add(&ubi
->cdev
, dev
, 1);
407 ubi_err("cannot add character device");
411 err
= ubi_sysfs_init(ubi
);
415 for (i
= 0; i
< ubi
->vtbl_slots
; i
++)
416 if (ubi
->volumes
[i
]) {
417 err
= ubi_add_volume(ubi
, ubi
->volumes
[i
]);
419 ubi_err("cannot add volume %d", i
);
429 ubi_sysfs_close(ubi
);
430 cdev_del(&ubi
->cdev
);
432 unregister_chrdev_region(ubi
->cdev
.dev
, ubi
->vtbl_slots
+ 1);
433 ubi_err("cannot initialize UBI %s, error %d", ubi
->ubi_name
, err
);
438 * uif_close - close user interfaces for an UBI device.
439 * @ubi: UBI device description object
441 static void uif_close(struct ubi_device
*ubi
)
444 ubi_sysfs_close(ubi
);
445 cdev_del(&ubi
->cdev
);
446 unregister_chrdev_region(ubi
->cdev
.dev
, ubi
->vtbl_slots
+ 1);
450 * attach_by_scanning - attach an MTD device using scanning method.
451 * @ubi: UBI device descriptor
453 * This function returns zero in case of success and a negative error code in
456 * Note, currently this is the only method to attach UBI devices. Hopefully in
457 * the future we'll have more scalable attaching methods and avoid full media
458 * scanning. But even in this case scanning will be needed as a fall-back
459 * attaching method if there are some on-flash table corruptions.
461 static int attach_by_scanning(struct ubi_device
*ubi
)
464 struct ubi_scan_info
*si
;
470 ubi
->bad_peb_count
= si
->bad_peb_count
;
471 ubi
->good_peb_count
= ubi
->peb_count
- ubi
->bad_peb_count
;
472 ubi
->max_ec
= si
->max_ec
;
473 ubi
->mean_ec
= si
->mean_ec
;
475 err
= ubi_read_volume_table(ubi
, si
);
479 err
= ubi_eba_init_scan(ubi
, si
);
483 err
= ubi_wl_init_scan(ubi
, si
);
487 ubi_scan_destroy_si(si
);
495 ubi_scan_destroy_si(si
);
500 * io_init - initialize I/O unit for a given UBI device.
501 * @ubi: UBI device description object
503 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
505 * o EC header is always at offset zero - this cannot be changed;
506 * o VID header starts just after the EC header at the closest address
507 * aligned to @io->hdrs_min_io_size;
508 * o data starts just after the VID header at the closest address aligned to
511 * This function returns zero in case of success and a negative error code in
514 static int io_init(struct ubi_device
*ubi
)
516 if (ubi
->mtd
->numeraseregions
!= 0) {
518 * Some flashes have several erase regions. Different regions
519 * may have different eraseblock size and other
520 * characteristics. It looks like mostly multi-region flashes
521 * have one "main" region and one or more small regions to
522 * store boot loader code or boot parameters or whatever. I
523 * guess we should just pick the largest region. But this is
526 ubi_err("multiple regions, not implemented");
530 if (ubi
->vid_hdr_offset
< 0)
534 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
535 * physical eraseblocks maximum.
538 ubi
->peb_size
= ubi
->mtd
->erasesize
;
539 ubi
->peb_count
= mtd_div_by_eb(ubi
->mtd
->size
, ubi
->mtd
);
540 ubi
->flash_size
= ubi
->mtd
->size
;
542 if (mtd_can_have_bb(ubi
->mtd
))
543 ubi
->bad_allowed
= 1;
545 ubi
->min_io_size
= ubi
->mtd
->writesize
;
546 ubi
->hdrs_min_io_size
= ubi
->mtd
->writesize
>> ubi
->mtd
->subpage_sft
;
549 * Make sure minimal I/O unit is power of 2. Note, there is no
550 * fundamental reason for this assumption. It is just an optimization
551 * which allows us to avoid costly division operations.
553 if (!is_power_of_2(ubi
->min_io_size
)) {
554 ubi_err("min. I/O unit (%d) is not power of 2",
559 ubi_assert(ubi
->hdrs_min_io_size
> 0);
560 ubi_assert(ubi
->hdrs_min_io_size
<= ubi
->min_io_size
);
561 ubi_assert(ubi
->min_io_size
% ubi
->hdrs_min_io_size
== 0);
563 /* Calculate default aligned sizes of EC and VID headers */
564 ubi
->ec_hdr_alsize
= ALIGN(UBI_EC_HDR_SIZE
, ubi
->hdrs_min_io_size
);
565 ubi
->vid_hdr_alsize
= ALIGN(UBI_VID_HDR_SIZE
, ubi
->hdrs_min_io_size
);
567 dbg_msg("min_io_size %d", ubi
->min_io_size
);
568 dbg_msg("hdrs_min_io_size %d", ubi
->hdrs_min_io_size
);
569 dbg_msg("ec_hdr_alsize %d", ubi
->ec_hdr_alsize
);
570 dbg_msg("vid_hdr_alsize %d", ubi
->vid_hdr_alsize
);
572 if (ubi
->vid_hdr_offset
== 0)
574 ubi
->vid_hdr_offset
= ubi
->vid_hdr_aloffset
=
577 ubi
->vid_hdr_aloffset
= ubi
->vid_hdr_offset
&
578 ~(ubi
->hdrs_min_io_size
- 1);
579 ubi
->vid_hdr_shift
= ubi
->vid_hdr_offset
-
580 ubi
->vid_hdr_aloffset
;
583 /* Similar for the data offset */
584 ubi
->leb_start
= ubi
->vid_hdr_offset
+ UBI_EC_HDR_SIZE
;
585 ubi
->leb_start
= ALIGN(ubi
->leb_start
, ubi
->min_io_size
);
587 dbg_msg("vid_hdr_offset %d", ubi
->vid_hdr_offset
);
588 dbg_msg("vid_hdr_aloffset %d", ubi
->vid_hdr_aloffset
);
589 dbg_msg("vid_hdr_shift %d", ubi
->vid_hdr_shift
);
590 dbg_msg("leb_start %d", ubi
->leb_start
);
592 /* The shift must be aligned to 32-bit boundary */
593 if (ubi
->vid_hdr_shift
% 4) {
594 ubi_err("unaligned VID header shift %d",
600 if (ubi
->vid_hdr_offset
< UBI_EC_HDR_SIZE
||
601 ubi
->leb_start
< ubi
->vid_hdr_offset
+ UBI_VID_HDR_SIZE
||
602 ubi
->leb_start
> ubi
->peb_size
- UBI_VID_HDR_SIZE
||
603 ubi
->leb_start
& (ubi
->min_io_size
- 1)) {
604 ubi_err("bad VID header (%d) or data offsets (%d)",
605 ubi
->vid_hdr_offset
, ubi
->leb_start
);
610 * It may happen that EC and VID headers are situated in one minimal
611 * I/O unit. In this case we can only accept this UBI image in
614 if (ubi
->vid_hdr_offset
+ UBI_VID_HDR_SIZE
<= ubi
->hdrs_min_io_size
) {
615 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
616 "switch to read-only mode");
620 ubi
->leb_size
= ubi
->peb_size
- ubi
->leb_start
;
622 if (!(ubi
->mtd
->flags
& MTD_WRITEABLE
)) {
623 ubi_msg("MTD device %d is write-protected, attach in "
624 "read-only mode", ubi
->mtd
->index
);
628 ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
629 ubi
->peb_size
, ubi
->peb_size
>> 10);
630 ubi_msg("logical eraseblock size: %d bytes", ubi
->leb_size
);
631 ubi_msg("smallest flash I/O unit: %d", ubi
->min_io_size
);
632 if (ubi
->hdrs_min_io_size
!= ubi
->min_io_size
)
633 ubi_msg("sub-page size: %d",
634 ubi
->hdrs_min_io_size
);
635 ubi_msg("VID header offset: %d (aligned %d)",
636 ubi
->vid_hdr_offset
, ubi
->vid_hdr_aloffset
);
637 ubi_msg("data offset: %d", ubi
->leb_start
);
640 * Note, ideally, we have to initialize ubi->bad_peb_count here. But
641 * unfortunately, MTD does not provide this information. We should loop
642 * over all physical eraseblocks and invoke mtd->block_is_bad() for
643 * each physical eraseblock. So, we skip ubi->bad_peb_count
644 * uninitialized and initialize it after scanning.
651 * autoresize - re-size the volume which has the "auto-resize" flag set.
652 * @ubi: UBI device description object
653 * @vol_id: ID of the volume to re-size
655 * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
656 * the volume table to the largest possible size. See comments in ubi-header.h
657 * for more description of the flag. Returns zero in case of success and a
658 * negative error code in case of failure.
660 static int autoresize(struct ubi_device
*ubi
, int vol_id
)
662 struct ubi_volume_desc desc
;
663 struct ubi_volume
*vol
= ubi
->volumes
[vol_id
];
664 int err
, old_reserved_pebs
= vol
->reserved_pebs
;
667 * Clear the auto-resize flag in the volume in-memory copy of the
668 * volume table, and 'ubi_resize_volume()' will propogate this change
671 ubi
->vtbl
[vol_id
].flags
&= ~UBI_VTBL_AUTORESIZE_FLG
;
673 if (ubi
->avail_pebs
== 0) {
674 struct ubi_vtbl_record vtbl_rec
;
677 * No avalilable PEBs to re-size the volume, clear the flag on
680 memcpy(&vtbl_rec
, &ubi
->vtbl
[vol_id
],
681 sizeof(struct ubi_vtbl_record
));
682 err
= ubi_change_vtbl_record(ubi
, vol_id
, &vtbl_rec
);
684 ubi_err("cannot clean auto-resize flag for volume %d",
688 err
= ubi_resize_volume(&desc
,
689 old_reserved_pebs
+ ubi
->avail_pebs
);
691 ubi_err("cannot auto-resize volume %d", vol_id
);
697 ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id
,
698 vol
->name
, old_reserved_pebs
, vol
->reserved_pebs
);
703 * ubi_attach_mtd_dev - attach an MTD device.
704 * @mtd_dev: MTD device description object
705 * @ubi_num: number to assign to the new UBI device
706 * @vid_hdr_offset: VID header offset
708 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
709 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
710 * which case this function finds a vacant device nubert and assings it
711 * automatically. Returns the new UBI device number in case of success and a
712 * negative error code in case of failure.
714 * Note, the invocations of this function has to be serialized by the
715 * @ubi_devices_mutex.
717 int ubi_attach_mtd_dev(struct mtd_info
*mtd
, int ubi_num
, int vid_hdr_offset
)
719 struct ubi_device
*ubi
;
723 * Check if we already have the same MTD device attached.
725 * Note, this function assumes that UBI devices creations and deletions
726 * are serialized, so it does not take the &ubi_devices_lock.
728 for (i
= 0; i
< UBI_MAX_DEVICES
; i
++) {
729 ubi
= ubi_devices
[i
];
730 if (ubi
&& mtd
->index
== ubi
->mtd
->index
) {
731 dbg_err("mtd%d is already attached to ubi%d",
738 * Make sure this MTD device is not emulated on top of an UBI volume
739 * already. Well, generally this recursion works fine, but there are
740 * different problems like the UBI module takes a reference to itself
741 * by attaching (and thus, opening) the emulated MTD device. This
742 * results in inability to unload the module. And in general it makes
743 * no sense to attach emulated MTD devices, so we prohibit this.
745 if (mtd
->type
== MTD_UBIVOLUME
) {
746 ubi_err("refuse attaching mtd%d - it is already emulated on "
747 "top of UBI", mtd
->index
);
751 if (ubi_num
== UBI_DEV_NUM_AUTO
) {
752 /* Search for an empty slot in the @ubi_devices array */
753 for (ubi_num
= 0; ubi_num
< UBI_MAX_DEVICES
; ubi_num
++)
754 if (!ubi_devices
[ubi_num
])
756 if (ubi_num
== UBI_MAX_DEVICES
) {
757 dbg_err("only %d UBI devices may be created", UBI_MAX_DEVICES
);
761 if (ubi_num
>= UBI_MAX_DEVICES
)
764 /* Make sure ubi_num is not busy */
765 if (ubi_devices
[ubi_num
]) {
766 dbg_err("ubi%d already exists", ubi_num
);
771 ubi
= kzalloc(sizeof(struct ubi_device
), GFP_KERNEL
);
776 ubi
->ubi_num
= ubi_num
;
777 ubi
->vid_hdr_offset
= vid_hdr_offset
;
778 ubi
->autoresize_vol_id
= -1;
780 mutex_init(&ubi
->buf_mutex
);
781 mutex_init(&ubi
->ckvol_mutex
);
782 mutex_init(&ubi
->volumes_mutex
);
783 spin_lock_init(&ubi
->volumes_lock
);
785 ubi_msg("attaching mtd%d to ubi%d", mtd
->index
, ubi_num
);
792 ubi
->peb_buf1
= vmalloc(ubi
->peb_size
);
796 ubi
->peb_buf2
= vmalloc(ubi
->peb_size
);
800 #ifdef CONFIG_MTD_UBI_DEBUG
801 mutex_init(&ubi
->dbg_buf_mutex
);
802 ubi
->dbg_peb_buf
= vmalloc(ubi
->peb_size
);
803 if (!ubi
->dbg_peb_buf
)
807 err
= attach_by_scanning(ubi
);
809 dbg_err("failed to attach by scanning, error %d", err
);
813 if (ubi
->autoresize_vol_id
!= -1) {
814 err
= autoresize(ubi
, ubi
->autoresize_vol_id
);
823 ubi
->bgt_thread
= kthread_create(ubi_thread
, ubi
, ubi
->bgt_name
);
824 if (IS_ERR(ubi
->bgt_thread
)) {
825 err
= PTR_ERR(ubi
->bgt_thread
);
826 ubi_err("cannot spawn \"%s\", error %d", ubi
->bgt_name
,
831 ubi_msg("attached mtd%d to ubi%d", mtd
->index
, ubi_num
);
832 ubi_msg("MTD device name: \"%s\"", mtd
->name
);
833 ubi_msg("MTD device size: %llu MiB", ubi
->flash_size
>> 20);
834 ubi_msg("number of good PEBs: %d", ubi
->good_peb_count
);
835 ubi_msg("number of bad PEBs: %d", ubi
->bad_peb_count
);
836 ubi_msg("max. allowed volumes: %d", ubi
->vtbl_slots
);
837 ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD
);
838 ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT
);
839 ubi_msg("number of user volumes: %d",
840 ubi
->vol_count
- UBI_INT_VOL_COUNT
);
841 ubi_msg("available PEBs: %d", ubi
->avail_pebs
);
842 ubi_msg("total number of reserved PEBs: %d", ubi
->rsvd_pebs
);
843 ubi_msg("number of PEBs reserved for bad PEB handling: %d",
845 ubi_msg("max/mean erase counter: %d/%d", ubi
->max_ec
, ubi
->mean_ec
);
847 /* Enable the background thread */
848 if (!DBG_DISABLE_BGT
) {
849 ubi
->thread_enabled
= 1;
850 wake_up_process(ubi
->bgt_thread
);
853 ubi_devices
[ubi_num
] = ubi
;
863 vfree(ubi
->peb_buf1
);
864 vfree(ubi
->peb_buf2
);
865 #ifdef CONFIG_MTD_UBI_DEBUG
866 vfree(ubi
->dbg_peb_buf
);
873 * ubi_detach_mtd_dev - detach an MTD device.
874 * @ubi_num: UBI device number to detach from
875 * @anyway: detach MTD even if device reference count is not zero
877 * This function destroys an UBI device number @ubi_num and detaches the
878 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
879 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
882 * Note, the invocations of this function has to be serialized by the
883 * @ubi_devices_mutex.
885 int ubi_detach_mtd_dev(int ubi_num
, int anyway
)
887 struct ubi_device
*ubi
;
889 if (ubi_num
< 0 || ubi_num
>= UBI_MAX_DEVICES
)
892 spin_lock(&ubi_devices_lock
);
893 ubi
= ubi_devices
[ubi_num
];
895 spin_unlock(&ubi_devices_lock
);
899 if (ubi
->ref_count
) {
901 spin_unlock(&ubi_devices_lock
);
904 /* This may only happen if there is a bug */
905 ubi_err("%s reference count %d, destroy anyway",
906 ubi
->ubi_name
, ubi
->ref_count
);
908 ubi_devices
[ubi_num
] = NULL
;
909 spin_unlock(&ubi_devices_lock
);
911 ubi_assert(ubi_num
== ubi
->ubi_num
);
912 dbg_msg("detaching mtd%d from ubi%d", ubi
->mtd
->index
, ubi_num
);
915 * Before freeing anything, we have to stop the background thread to
916 * prevent it from doing anything on this device while we are freeing.
919 kthread_stop(ubi
->bgt_thread
);
925 put_mtd_device(ubi
->mtd
);
926 vfree(ubi
->peb_buf1
);
927 vfree(ubi
->peb_buf2
);
928 #ifdef CONFIG_MTD_UBI_DEBUG
929 vfree(ubi
->dbg_peb_buf
);
931 ubi_msg("mtd%d is detached from ubi%d", ubi
->mtd
->index
, ubi
->ubi_num
);
937 * find_mtd_device - open an MTD device by its name or number.
938 * @mtd_dev: name or number of the device
940 * This function tries to open and MTD device described by @mtd_dev string,
941 * which is first treated as an ASCII number, and if it is not true, it is
942 * treated as MTD device name. Returns MTD device description object in case of
943 * success and a negative error code in case of failure.
945 static struct mtd_info
* __init
open_mtd_device(const char *mtd_dev
)
947 struct mtd_info
*mtd
;
951 mtd_num
= simple_strtoul(mtd_dev
, &endp
, 0);
952 if (*endp
!= '\0' || mtd_dev
== endp
) {
954 * This does not look like an ASCII integer, probably this is
957 mtd
= get_mtd_device_nm(mtd_dev
);
959 mtd
= get_mtd_device(NULL
, mtd_num
);
964 int __init
ubi_init(void)
968 /* Ensure that EC and VID headers have correct size */
969 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr
) != 64);
970 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr
) != 64);
972 if (mtd_devs
> UBI_MAX_DEVICES
) {
973 ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES
);
977 /* Create base sysfs directory and sysfs files */
978 ubi_class
= class_create(THIS_MODULE
, UBI_NAME_STR
);
979 if (IS_ERR(ubi_class
)) {
980 err
= PTR_ERR(ubi_class
);
981 ubi_err("cannot create UBI class");
985 err
= class_create_file(ubi_class
, &ubi_version
);
987 ubi_err("cannot create sysfs file");
991 err
= misc_register(&ubi_ctrl_cdev
);
993 ubi_err("cannot register device");
998 ubi_wl_entry_slab
= kmem_cache_create("ubi_wl_entry_slab",
999 sizeof(struct ubi_wl_entry
),
1001 if (!ubi_wl_entry_slab
)
1005 /* Attach MTD devices */
1006 for (i
= 0; i
< mtd_devs
; i
++) {
1007 struct mtd_dev_param
*p
= &mtd_dev_param
[i
];
1008 struct mtd_info
*mtd
;
1012 mtd
= open_mtd_device(p
->name
);
1018 mutex_lock(&ubi_devices_mutex
);
1019 err
= ubi_attach_mtd_dev(mtd
, UBI_DEV_NUM_AUTO
,
1021 mutex_unlock(&ubi_devices_mutex
);
1023 put_mtd_device(mtd
);
1024 ubi_err("cannot attach mtd%d", mtd
->index
);
1032 for (k
= 0; k
< i
; k
++)
1033 if (ubi_devices
[k
]) {
1034 mutex_lock(&ubi_devices_mutex
);
1035 ubi_detach_mtd_dev(ubi_devices
[k
]->ubi_num
, 1);
1036 mutex_unlock(&ubi_devices_mutex
);
1039 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
);
1049 ubi_err("UBI error: cannot initialize UBI, error %d", err
);
1052 module_init(ubi_init
);
1054 void __exit
ubi_exit(void)
1058 for (i
= 0; i
< UBI_MAX_DEVICES
; i
++)
1059 if (ubi_devices
[i
]) {
1060 mutex_lock(&ubi_devices_mutex
);
1061 ubi_detach_mtd_dev(ubi_devices
[i
]->ubi_num
, 1);
1062 mutex_unlock(&ubi_devices_mutex
);
1064 kmem_cache_destroy(ubi_wl_entry_slab
);
1065 misc_deregister(&ubi_ctrl_cdev
);
1066 class_remove_file(ubi_class
, &ubi_version
);
1067 class_destroy(ubi_class
);
1070 module_exit(ubi_exit
);
1073 * bytes_str_to_int - convert a string representing number of bytes to an
1075 * @str: the string to convert
1077 * This function returns positive resulting integer in case of success and a
1078 * negative error code in case of failure.
1080 static int __init
bytes_str_to_int(const char *str
)
1083 unsigned long result
;
1085 result
= simple_strtoul(str
, &endp
, 0);
1086 if (str
== endp
|| result
< 0) {
1087 printk(KERN_ERR
"UBI error: incorrect bytes count: \"%s\"\n",
1099 if (endp
[1] == 'i' && endp
[2] == 'B')
1104 printk(KERN_ERR
"UBI error: incorrect bytes count: \"%s\"\n",
1113 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1114 * @val: the parameter value to parse
1117 * This function returns zero in case of success and a negative error code in
1120 int __init
ubi_mtd_param_parse(const char *val
, struct kernel_param
*kp
)
1123 struct mtd_dev_param
*p
;
1124 char buf
[MTD_PARAM_LEN_MAX
];
1125 char *pbuf
= &buf
[0];
1126 char *tokens
[2] = {NULL
, NULL
};
1131 if (mtd_devs
== UBI_MAX_DEVICES
) {
1132 printk(KERN_ERR
"UBI error: too many parameters, max. is %d\n",
1137 len
= strnlen(val
, MTD_PARAM_LEN_MAX
);
1138 if (len
== MTD_PARAM_LEN_MAX
) {
1139 printk(KERN_ERR
"UBI error: parameter \"%s\" is too long, "
1140 "max. is %d\n", val
, MTD_PARAM_LEN_MAX
);
1145 printk(KERN_WARNING
"UBI warning: empty 'mtd=' parameter - "
1152 /* Get rid of the final newline */
1153 if (buf
[len
- 1] == '\n')
1154 buf
[len
- 1] = '\0';
1156 for (i
= 0; i
< 2; i
++)
1157 tokens
[i
] = strsep(&pbuf
, ",");
1160 printk(KERN_ERR
"UBI error: too many arguments at \"%s\"\n",
1165 p
= &mtd_dev_param
[mtd_devs
];
1166 strcpy(&p
->name
[0], tokens
[0]);
1169 p
->vid_hdr_offs
= bytes_str_to_int(tokens
[1]);
1171 if (p
->vid_hdr_offs
< 0)
1172 return p
->vid_hdr_offs
;
1178 module_param_call(mtd
, ubi_mtd_param_parse
, NULL
, NULL
, 000);
1179 MODULE_PARM_DESC(mtd
, "MTD devices to attach. Parameter format: "
1180 "mtd=<name|num>[,<vid_hdr_offs>].\n"
1181 "Multiple \"mtd\" parameters may be specified.\n"
1182 "MTD devices may be specified by their number or name.\n"
1183 "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
1184 "header position and data starting position to be used "
1186 "Example: mtd=content,1984 mtd=4 - attach MTD device"
1187 "with name \"content\" using VID header offset 1984, and "
1188 "MTD device number 4 with default VID header offset.");
1190 MODULE_VERSION(__stringify(UBI_VERSION
));
1191 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1192 MODULE_AUTHOR("Artem Bityutskiy");
1193 MODULE_LICENSE("GPL");