2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2007
5 * SPDX-License-Identifier: GPL-2.0+
7 * Author: Artem Bityutskiy (Битюцкий Артём),
12 * This file includes UBI initialization and building of UBI devices.
14 * When UBI is initialized, it attaches all the MTD devices specified as the
15 * module load parameters or the kernel boot parameters. If MTD devices were
16 * specified, UBI does not attach any MTD device, but it is possible to do
17 * later using the "UBI control device".
19 * At the moment we only attach UBI devices by scanning, which will become a
20 * bottleneck when flashes reach certain large size. Then one may improve UBI
21 * and add other methods, although it does not seem to be easy to do.
25 #include <linux/err.h>
26 #include <linux/module.h>
27 #include <linux/moduleparam.h>
28 #include <linux/stringify.h>
29 #include <linux/stat.h>
30 #include <linux/miscdevice.h>
31 #include <linux/log2.h>
32 #include <linux/kthread.h>
34 #include <ubi_uboot.h>
37 #if (CONFIG_SYS_MALLOC_LEN < (512 << 10))
38 #error Malloc area too small for UBI, increase CONFIG_SYS_MALLOC_LEN to >= 512k
41 /* Maximum length of the 'mtd=' parameter */
42 #define MTD_PARAM_LEN_MAX 64
45 * struct mtd_dev_param - MTD device parameter description data structure.
46 * @name: MTD device name or number string
47 * @vid_hdr_offs: VID header offset
51 char name
[MTD_PARAM_LEN_MAX
];
55 /* Numbers of elements set in the @mtd_dev_param array */
56 static int mtd_devs
= 0;
58 /* MTD devices specification parameters */
59 static struct mtd_dev_param mtd_dev_param
[UBI_MAX_DEVICES
];
61 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
62 struct class *ubi_class
;
65 /* Slab cache for wear-leveling entries */
66 struct kmem_cache
*ubi_wl_entry_slab
;
68 /* UBI control character device */
69 static struct miscdevice ubi_ctrl_cdev
= {
70 .minor
= MISC_DYNAMIC_MINOR
,
72 .fops
= &ubi_ctrl_cdev_operations
,
76 /* All UBI devices in system */
77 struct ubi_device
*ubi_devices
[UBI_MAX_DEVICES
];
80 /* Serializes UBI devices creations and removals */
81 DEFINE_MUTEX(ubi_devices_mutex
);
83 /* Protects @ubi_devices and @ubi->ref_count */
84 static DEFINE_SPINLOCK(ubi_devices_lock
);
86 /* "Show" method for files in '/<sysfs>/class/ubi/' */
87 static ssize_t
ubi_version_show(struct class *class, char *buf
)
89 return sprintf(buf
, "%d\n", UBI_VERSION
);
92 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
93 static struct class_attribute ubi_version
=
94 __ATTR(version
, S_IRUGO
, ubi_version_show
, NULL
);
96 static ssize_t
dev_attribute_show(struct device
*dev
,
97 struct device_attribute
*attr
, char *buf
);
99 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
100 static struct device_attribute dev_eraseblock_size
=
101 __ATTR(eraseblock_size
, S_IRUGO
, dev_attribute_show
, NULL
);
102 static struct device_attribute dev_avail_eraseblocks
=
103 __ATTR(avail_eraseblocks
, S_IRUGO
, dev_attribute_show
, NULL
);
104 static struct device_attribute dev_total_eraseblocks
=
105 __ATTR(total_eraseblocks
, S_IRUGO
, dev_attribute_show
, NULL
);
106 static struct device_attribute dev_volumes_count
=
107 __ATTR(volumes_count
, S_IRUGO
, dev_attribute_show
, NULL
);
108 static struct device_attribute dev_max_ec
=
109 __ATTR(max_ec
, S_IRUGO
, dev_attribute_show
, NULL
);
110 static struct device_attribute dev_reserved_for_bad
=
111 __ATTR(reserved_for_bad
, S_IRUGO
, dev_attribute_show
, NULL
);
112 static struct device_attribute dev_bad_peb_count
=
113 __ATTR(bad_peb_count
, S_IRUGO
, dev_attribute_show
, NULL
);
114 static struct device_attribute dev_max_vol_count
=
115 __ATTR(max_vol_count
, S_IRUGO
, dev_attribute_show
, NULL
);
116 static struct device_attribute dev_min_io_size
=
117 __ATTR(min_io_size
, S_IRUGO
, dev_attribute_show
, NULL
);
118 static struct device_attribute dev_bgt_enabled
=
119 __ATTR(bgt_enabled
, S_IRUGO
, dev_attribute_show
, NULL
);
120 static struct device_attribute dev_mtd_num
=
121 __ATTR(mtd_num
, S_IRUGO
, dev_attribute_show
, NULL
);
125 * ubi_get_device - get UBI device.
126 * @ubi_num: UBI device number
128 * This function returns UBI device description object for UBI device number
129 * @ubi_num, or %NULL if the device does not exist. This function increases the
130 * device reference count to prevent removal of the device. In other words, the
131 * device cannot be removed if its reference count is not zero.
133 struct ubi_device
*ubi_get_device(int ubi_num
)
135 struct ubi_device
*ubi
;
137 spin_lock(&ubi_devices_lock
);
138 ubi
= ubi_devices
[ubi_num
];
140 ubi_assert(ubi
->ref_count
>= 0);
142 get_device(&ubi
->dev
);
144 spin_unlock(&ubi_devices_lock
);
150 * ubi_put_device - drop an UBI device reference.
151 * @ubi: UBI device description object
153 void ubi_put_device(struct ubi_device
*ubi
)
155 spin_lock(&ubi_devices_lock
);
157 put_device(&ubi
->dev
);
158 spin_unlock(&ubi_devices_lock
);
162 * ubi_get_by_major - get UBI device description object by character device
164 * @major: major number
166 * This function is similar to 'ubi_get_device()', but it searches the device
167 * by its major number.
169 struct ubi_device
*ubi_get_by_major(int major
)
172 struct ubi_device
*ubi
;
174 spin_lock(&ubi_devices_lock
);
175 for (i
= 0; i
< UBI_MAX_DEVICES
; i
++) {
176 ubi
= ubi_devices
[i
];
177 if (ubi
&& MAJOR(ubi
->cdev
.dev
) == major
) {
178 ubi_assert(ubi
->ref_count
>= 0);
180 get_device(&ubi
->dev
);
181 spin_unlock(&ubi_devices_lock
);
185 spin_unlock(&ubi_devices_lock
);
191 * ubi_major2num - get UBI device number by character device major number.
192 * @major: major number
194 * This function searches UBI device number object by its major number. If UBI
195 * device was not found, this function returns -ENODEV, otherwise the UBI device
196 * number is returned.
198 int ubi_major2num(int major
)
200 int i
, ubi_num
= -ENODEV
;
202 spin_lock(&ubi_devices_lock
);
203 for (i
= 0; i
< UBI_MAX_DEVICES
; i
++) {
204 struct ubi_device
*ubi
= ubi_devices
[i
];
206 if (ubi
&& MAJOR(ubi
->cdev
.dev
) == major
) {
207 ubi_num
= ubi
->ubi_num
;
211 spin_unlock(&ubi_devices_lock
);
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
);
346 * kill_volumes - destroy all volumes.
347 * @ubi: UBI device description object
349 static void kill_volumes(struct ubi_device
*ubi
)
353 for (i
= 0; i
< ubi
->vtbl_slots
; i
++)
355 ubi_free_volume(ubi
, ubi
->volumes
[i
]);
359 * uif_init - initialize user interfaces for an UBI device.
360 * @ubi: UBI device description object
362 * This function returns zero in case of success and a negative error code in
365 static int uif_init(struct ubi_device
*ubi
)
372 sprintf(ubi
->ubi_name
, UBI_NAME_STR
"%d", ubi
->ubi_num
);
375 * Major numbers for the UBI character devices are allocated
376 * dynamically. Major numbers of volume character devices are
377 * equivalent to ones of the corresponding UBI character device. Minor
378 * numbers of UBI character devices are 0, while minor numbers of
379 * volume character devices start from 1. Thus, we allocate one major
380 * number and ubi->vtbl_slots + 1 minor numbers.
382 err
= alloc_chrdev_region(&dev
, 0, ubi
->vtbl_slots
+ 1, ubi
->ubi_name
);
384 ubi_err("cannot register UBI character devices");
388 ubi_assert(MINOR(dev
) == 0);
389 cdev_init(&ubi
->cdev
, &ubi_cdev_operations
);
390 dbg_msg("%s major is %u", ubi
->ubi_name
, MAJOR(dev
));
391 ubi
->cdev
.owner
= THIS_MODULE
;
393 err
= cdev_add(&ubi
->cdev
, dev
, 1);
395 ubi_err("cannot add character device");
399 err
= ubi_sysfs_init(ubi
);
403 for (i
= 0; i
< ubi
->vtbl_slots
; i
++)
404 if (ubi
->volumes
[i
]) {
405 err
= ubi_add_volume(ubi
, ubi
->volumes
[i
]);
407 ubi_err("cannot add volume %d", i
);
417 ubi_sysfs_close(ubi
);
418 cdev_del(&ubi
->cdev
);
420 unregister_chrdev_region(ubi
->cdev
.dev
, ubi
->vtbl_slots
+ 1);
421 ubi_err("cannot initialize UBI %s, error %d", ubi
->ubi_name
, err
);
426 * uif_close - close user interfaces for an UBI device.
427 * @ubi: UBI device description object
429 static void uif_close(struct ubi_device
*ubi
)
432 ubi_sysfs_close(ubi
);
433 cdev_del(&ubi
->cdev
);
434 unregister_chrdev_region(ubi
->cdev
.dev
, ubi
->vtbl_slots
+ 1);
438 * attach_by_scanning - attach an MTD device using scanning method.
439 * @ubi: UBI device descriptor
441 * This function returns zero in case of success and a negative error code in
444 * Note, currently this is the only method to attach UBI devices. Hopefully in
445 * the future we'll have more scalable attaching methods and avoid full media
446 * scanning. But even in this case scanning will be needed as a fall-back
447 * attaching method if there are some on-flash table corruptions.
449 static int attach_by_scanning(struct ubi_device
*ubi
)
452 struct ubi_scan_info
*si
;
458 ubi
->bad_peb_count
= si
->bad_peb_count
;
459 ubi
->good_peb_count
= ubi
->peb_count
- ubi
->bad_peb_count
;
460 ubi
->max_ec
= si
->max_ec
;
461 ubi
->mean_ec
= si
->mean_ec
;
463 err
= ubi_read_volume_table(ubi
, si
);
467 err
= ubi_eba_init_scan(ubi
, si
);
471 err
= ubi_wl_init_scan(ubi
, si
);
475 ubi_scan_destroy_si(si
);
483 ubi_scan_destroy_si(si
);
488 * io_init - initialize I/O unit for a given UBI device.
489 * @ubi: UBI device description object
491 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
493 * o EC header is always at offset zero - this cannot be changed;
494 * o VID header starts just after the EC header at the closest address
495 * aligned to @io->hdrs_min_io_size;
496 * o data starts just after the VID header at the closest address aligned to
499 * This function returns zero in case of success and a negative error code in
502 static int io_init(struct ubi_device
*ubi
)
504 if (ubi
->mtd
->numeraseregions
!= 0) {
506 * Some flashes have several erase regions. Different regions
507 * may have different eraseblock size and other
508 * characteristics. It looks like mostly multi-region flashes
509 * have one "main" region and one or more small regions to
510 * store boot loader code or boot parameters or whatever. I
511 * guess we should just pick the largest region. But this is
514 ubi_err("multiple regions, not implemented");
518 if (ubi
->vid_hdr_offset
< 0)
522 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
523 * physical eraseblocks maximum.
526 ubi
->peb_size
= ubi
->mtd
->erasesize
;
527 ubi
->peb_count
= mtd_div_by_eb(ubi
->mtd
->size
, ubi
->mtd
);
528 ubi
->flash_size
= ubi
->mtd
->size
;
530 if (mtd_can_have_bb(ubi
->mtd
))
531 ubi
->bad_allowed
= 1;
533 ubi
->min_io_size
= ubi
->mtd
->writesize
;
534 ubi
->hdrs_min_io_size
= ubi
->mtd
->writesize
>> ubi
->mtd
->subpage_sft
;
537 * Make sure minimal I/O unit is power of 2. Note, there is no
538 * fundamental reason for this assumption. It is just an optimization
539 * which allows us to avoid costly division operations.
541 if (!is_power_of_2(ubi
->min_io_size
)) {
542 ubi_err("min. I/O unit (%d) is not power of 2",
547 ubi_assert(ubi
->hdrs_min_io_size
> 0);
548 ubi_assert(ubi
->hdrs_min_io_size
<= ubi
->min_io_size
);
549 ubi_assert(ubi
->min_io_size
% ubi
->hdrs_min_io_size
== 0);
551 /* Calculate default aligned sizes of EC and VID headers */
552 ubi
->ec_hdr_alsize
= ALIGN(UBI_EC_HDR_SIZE
, ubi
->hdrs_min_io_size
);
553 ubi
->vid_hdr_alsize
= ALIGN(UBI_VID_HDR_SIZE
, ubi
->hdrs_min_io_size
);
555 dbg_msg("min_io_size %d", ubi
->min_io_size
);
556 dbg_msg("hdrs_min_io_size %d", ubi
->hdrs_min_io_size
);
557 dbg_msg("ec_hdr_alsize %d", ubi
->ec_hdr_alsize
);
558 dbg_msg("vid_hdr_alsize %d", ubi
->vid_hdr_alsize
);
560 if (ubi
->vid_hdr_offset
== 0)
562 ubi
->vid_hdr_offset
= ubi
->vid_hdr_aloffset
=
565 ubi
->vid_hdr_aloffset
= ubi
->vid_hdr_offset
&
566 ~(ubi
->hdrs_min_io_size
- 1);
567 ubi
->vid_hdr_shift
= ubi
->vid_hdr_offset
-
568 ubi
->vid_hdr_aloffset
;
571 /* Similar for the data offset */
572 ubi
->leb_start
= ubi
->vid_hdr_offset
+ UBI_EC_HDR_SIZE
;
573 ubi
->leb_start
= ALIGN(ubi
->leb_start
, ubi
->min_io_size
);
575 dbg_msg("vid_hdr_offset %d", ubi
->vid_hdr_offset
);
576 dbg_msg("vid_hdr_aloffset %d", ubi
->vid_hdr_aloffset
);
577 dbg_msg("vid_hdr_shift %d", ubi
->vid_hdr_shift
);
578 dbg_msg("leb_start %d", ubi
->leb_start
);
580 /* The shift must be aligned to 32-bit boundary */
581 if (ubi
->vid_hdr_shift
% 4) {
582 ubi_err("unaligned VID header shift %d",
588 if (ubi
->vid_hdr_offset
< UBI_EC_HDR_SIZE
||
589 ubi
->leb_start
< ubi
->vid_hdr_offset
+ UBI_VID_HDR_SIZE
||
590 ubi
->leb_start
> ubi
->peb_size
- UBI_VID_HDR_SIZE
||
591 ubi
->leb_start
& (ubi
->min_io_size
- 1)) {
592 ubi_err("bad VID header (%d) or data offsets (%d)",
593 ubi
->vid_hdr_offset
, ubi
->leb_start
);
598 * It may happen that EC and VID headers are situated in one minimal
599 * I/O unit. In this case we can only accept this UBI image in
602 if (ubi
->vid_hdr_offset
+ UBI_VID_HDR_SIZE
<= ubi
->hdrs_min_io_size
) {
603 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
604 "switch to read-only mode");
608 ubi
->leb_size
= ubi
->peb_size
- ubi
->leb_start
;
610 if (!(ubi
->mtd
->flags
& MTD_WRITEABLE
)) {
611 ubi_msg("MTD device %d is write-protected, attach in "
612 "read-only mode", ubi
->mtd
->index
);
616 ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
617 ubi
->peb_size
, ubi
->peb_size
>> 10);
618 ubi_msg("logical eraseblock size: %d bytes", ubi
->leb_size
);
619 ubi_msg("smallest flash I/O unit: %d", ubi
->min_io_size
);
620 if (ubi
->hdrs_min_io_size
!= ubi
->min_io_size
)
621 ubi_msg("sub-page size: %d",
622 ubi
->hdrs_min_io_size
);
623 ubi_msg("VID header offset: %d (aligned %d)",
624 ubi
->vid_hdr_offset
, ubi
->vid_hdr_aloffset
);
625 ubi_msg("data offset: %d", ubi
->leb_start
);
628 * Note, ideally, we have to initialize ubi->bad_peb_count here. But
629 * unfortunately, MTD does not provide this information. We should loop
630 * over all physical eraseblocks and invoke mtd->block_is_bad() for
631 * each physical eraseblock. So, we skip ubi->bad_peb_count
632 * uninitialized and initialize it after scanning.
639 * autoresize - re-size the volume which has the "auto-resize" flag set.
640 * @ubi: UBI device description object
641 * @vol_id: ID of the volume to re-size
643 * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
644 * the volume table to the largest possible size. See comments in ubi-header.h
645 * for more description of the flag. Returns zero in case of success and a
646 * negative error code in case of failure.
648 static int autoresize(struct ubi_device
*ubi
, int vol_id
)
650 struct ubi_volume_desc desc
;
651 struct ubi_volume
*vol
= ubi
->volumes
[vol_id
];
652 int err
, old_reserved_pebs
= vol
->reserved_pebs
;
655 * Clear the auto-resize flag in the volume in-memory copy of the
656 * volume table, and 'ubi_resize_volume()' will propogate this change
659 ubi
->vtbl
[vol_id
].flags
&= ~UBI_VTBL_AUTORESIZE_FLG
;
661 if (ubi
->avail_pebs
== 0) {
662 struct ubi_vtbl_record vtbl_rec
;
665 * No avalilable PEBs to re-size the volume, clear the flag on
668 memcpy(&vtbl_rec
, &ubi
->vtbl
[vol_id
],
669 sizeof(struct ubi_vtbl_record
));
670 err
= ubi_change_vtbl_record(ubi
, vol_id
, &vtbl_rec
);
672 ubi_err("cannot clean auto-resize flag for volume %d",
676 err
= ubi_resize_volume(&desc
,
677 old_reserved_pebs
+ ubi
->avail_pebs
);
679 ubi_err("cannot auto-resize volume %d", vol_id
);
685 ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id
,
686 vol
->name
, old_reserved_pebs
, vol
->reserved_pebs
);
691 * ubi_attach_mtd_dev - attach an MTD device.
692 * @mtd_dev: MTD device description object
693 * @ubi_num: number to assign to the new UBI device
694 * @vid_hdr_offset: VID header offset
696 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
697 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
698 * which case this function finds a vacant device nubert and assings it
699 * automatically. Returns the new UBI device number in case of success and a
700 * negative error code in case of failure.
702 * Note, the invocations of this function has to be serialized by the
703 * @ubi_devices_mutex.
705 int ubi_attach_mtd_dev(struct mtd_info
*mtd
, int ubi_num
, int vid_hdr_offset
)
707 struct ubi_device
*ubi
;
711 * Check if we already have the same MTD device attached.
713 * Note, this function assumes that UBI devices creations and deletions
714 * are serialized, so it does not take the &ubi_devices_lock.
716 for (i
= 0; i
< UBI_MAX_DEVICES
; i
++) {
717 ubi
= ubi_devices
[i
];
718 if (ubi
&& mtd
->index
== ubi
->mtd
->index
) {
719 dbg_err("mtd%d is already attached to ubi%d",
726 * Make sure this MTD device is not emulated on top of an UBI volume
727 * already. Well, generally this recursion works fine, but there are
728 * different problems like the UBI module takes a reference to itself
729 * by attaching (and thus, opening) the emulated MTD device. This
730 * results in inability to unload the module. And in general it makes
731 * no sense to attach emulated MTD devices, so we prohibit this.
733 if (mtd
->type
== MTD_UBIVOLUME
) {
734 ubi_err("refuse attaching mtd%d - it is already emulated on "
735 "top of UBI", mtd
->index
);
739 if (ubi_num
== UBI_DEV_NUM_AUTO
) {
740 /* Search for an empty slot in the @ubi_devices array */
741 for (ubi_num
= 0; ubi_num
< UBI_MAX_DEVICES
; ubi_num
++)
742 if (!ubi_devices
[ubi_num
])
744 if (ubi_num
== UBI_MAX_DEVICES
) {
745 dbg_err("only %d UBI devices may be created", UBI_MAX_DEVICES
);
749 if (ubi_num
>= UBI_MAX_DEVICES
)
752 /* Make sure ubi_num is not busy */
753 if (ubi_devices
[ubi_num
]) {
754 dbg_err("ubi%d already exists", ubi_num
);
759 ubi
= kzalloc(sizeof(struct ubi_device
), GFP_KERNEL
);
764 ubi
->ubi_num
= ubi_num
;
765 ubi
->vid_hdr_offset
= vid_hdr_offset
;
766 ubi
->autoresize_vol_id
= -1;
768 mutex_init(&ubi
->buf_mutex
);
769 mutex_init(&ubi
->ckvol_mutex
);
770 mutex_init(&ubi
->volumes_mutex
);
771 spin_lock_init(&ubi
->volumes_lock
);
773 ubi_msg("attaching mtd%d to ubi%d", mtd
->index
, ubi_num
);
780 ubi
->peb_buf1
= vmalloc(ubi
->peb_size
);
784 ubi
->peb_buf2
= vmalloc(ubi
->peb_size
);
788 #ifdef CONFIG_MTD_UBI_DEBUG
789 mutex_init(&ubi
->dbg_buf_mutex
);
790 ubi
->dbg_peb_buf
= vmalloc(ubi
->peb_size
);
791 if (!ubi
->dbg_peb_buf
)
795 err
= attach_by_scanning(ubi
);
797 dbg_err("failed to attach by scanning, error %d", err
);
801 if (ubi
->autoresize_vol_id
!= -1) {
802 err
= autoresize(ubi
, ubi
->autoresize_vol_id
);
811 ubi
->bgt_thread
= kthread_create(ubi_thread
, ubi
, ubi
->bgt_name
);
812 if (IS_ERR(ubi
->bgt_thread
)) {
813 err
= PTR_ERR(ubi
->bgt_thread
);
814 ubi_err("cannot spawn \"%s\", error %d", ubi
->bgt_name
,
819 ubi_msg("attached mtd%d to ubi%d", mtd
->index
, ubi_num
);
820 ubi_msg("MTD device name: \"%s\"", mtd
->name
);
821 ubi_msg("MTD device size: %llu MiB", ubi
->flash_size
>> 20);
822 ubi_msg("number of good PEBs: %d", ubi
->good_peb_count
);
823 ubi_msg("number of bad PEBs: %d", ubi
->bad_peb_count
);
824 ubi_msg("max. allowed volumes: %d", ubi
->vtbl_slots
);
825 ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD
);
826 ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT
);
827 ubi_msg("number of user volumes: %d",
828 ubi
->vol_count
- UBI_INT_VOL_COUNT
);
829 ubi_msg("available PEBs: %d", ubi
->avail_pebs
);
830 ubi_msg("total number of reserved PEBs: %d", ubi
->rsvd_pebs
);
831 ubi_msg("number of PEBs reserved for bad PEB handling: %d",
833 ubi_msg("max/mean erase counter: %d/%d", ubi
->max_ec
, ubi
->mean_ec
);
835 /* Enable the background thread */
836 if (!DBG_DISABLE_BGT
) {
837 ubi
->thread_enabled
= 1;
838 wake_up_process(ubi
->bgt_thread
);
841 ubi_devices
[ubi_num
] = ubi
;
851 vfree(ubi
->peb_buf1
);
852 vfree(ubi
->peb_buf2
);
853 #ifdef CONFIG_MTD_UBI_DEBUG
854 vfree(ubi
->dbg_peb_buf
);
861 * ubi_detach_mtd_dev - detach an MTD device.
862 * @ubi_num: UBI device number to detach from
863 * @anyway: detach MTD even if device reference count is not zero
865 * This function destroys an UBI device number @ubi_num and detaches the
866 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
867 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
870 * Note, the invocations of this function has to be serialized by the
871 * @ubi_devices_mutex.
873 int ubi_detach_mtd_dev(int ubi_num
, int anyway
)
875 struct ubi_device
*ubi
;
877 if (ubi_num
< 0 || ubi_num
>= UBI_MAX_DEVICES
)
880 spin_lock(&ubi_devices_lock
);
881 ubi
= ubi_devices
[ubi_num
];
883 spin_unlock(&ubi_devices_lock
);
887 if (ubi
->ref_count
) {
889 spin_unlock(&ubi_devices_lock
);
892 /* This may only happen if there is a bug */
893 ubi_err("%s reference count %d, destroy anyway",
894 ubi
->ubi_name
, ubi
->ref_count
);
896 ubi_devices
[ubi_num
] = NULL
;
897 spin_unlock(&ubi_devices_lock
);
899 ubi_assert(ubi_num
== ubi
->ubi_num
);
900 dbg_msg("detaching mtd%d from ubi%d", ubi
->mtd
->index
, ubi_num
);
903 * Before freeing anything, we have to stop the background thread to
904 * prevent it from doing anything on this device while we are freeing.
907 kthread_stop(ubi
->bgt_thread
);
913 put_mtd_device(ubi
->mtd
);
914 vfree(ubi
->peb_buf1
);
915 vfree(ubi
->peb_buf2
);
916 #ifdef CONFIG_MTD_UBI_DEBUG
917 vfree(ubi
->dbg_peb_buf
);
919 ubi_msg("mtd%d is detached from ubi%d", ubi
->mtd
->index
, ubi
->ubi_num
);
925 * find_mtd_device - open an MTD device by its name or number.
926 * @mtd_dev: name or number of the device
928 * This function tries to open and MTD device described by @mtd_dev string,
929 * which is first treated as an ASCII number, and if it is not true, it is
930 * treated as MTD device name. Returns MTD device description object in case of
931 * success and a negative error code in case of failure.
933 static struct mtd_info
* __init
open_mtd_device(const char *mtd_dev
)
935 struct mtd_info
*mtd
;
939 mtd_num
= simple_strtoul(mtd_dev
, &endp
, 0);
940 if (*endp
!= '\0' || mtd_dev
== endp
) {
942 * This does not look like an ASCII integer, probably this is
945 mtd
= get_mtd_device_nm(mtd_dev
);
947 mtd
= get_mtd_device(NULL
, mtd_num
);
952 int __init
ubi_init(void)
956 /* Ensure that EC and VID headers have correct size */
957 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr
) != 64);
958 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr
) != 64);
960 if (mtd_devs
> UBI_MAX_DEVICES
) {
961 ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES
);
965 /* Create base sysfs directory and sysfs files */
966 ubi_class
= class_create(THIS_MODULE
, UBI_NAME_STR
);
967 if (IS_ERR(ubi_class
)) {
968 err
= PTR_ERR(ubi_class
);
969 ubi_err("cannot create UBI class");
973 err
= class_create_file(ubi_class
, &ubi_version
);
975 ubi_err("cannot create sysfs file");
979 err
= misc_register(&ubi_ctrl_cdev
);
981 ubi_err("cannot register device");
986 ubi_wl_entry_slab
= kmem_cache_create("ubi_wl_entry_slab",
987 sizeof(struct ubi_wl_entry
),
989 if (!ubi_wl_entry_slab
)
993 /* Attach MTD devices */
994 for (i
= 0; i
< mtd_devs
; i
++) {
995 struct mtd_dev_param
*p
= &mtd_dev_param
[i
];
996 struct mtd_info
*mtd
;
1000 mtd
= open_mtd_device(p
->name
);
1006 mutex_lock(&ubi_devices_mutex
);
1007 err
= ubi_attach_mtd_dev(mtd
, UBI_DEV_NUM_AUTO
,
1009 mutex_unlock(&ubi_devices_mutex
);
1011 put_mtd_device(mtd
);
1012 ubi_err("cannot attach mtd%d", mtd
->index
);
1020 for (k
= 0; k
< i
; k
++)
1021 if (ubi_devices
[k
]) {
1022 mutex_lock(&ubi_devices_mutex
);
1023 ubi_detach_mtd_dev(ubi_devices
[k
]->ubi_num
, 1);
1024 mutex_unlock(&ubi_devices_mutex
);
1027 kmem_cache_destroy(ubi_wl_entry_slab
);
1030 misc_deregister(&ubi_ctrl_cdev
);
1032 class_remove_file(ubi_class
, &ubi_version
);
1034 class_destroy(ubi_class
);
1037 ubi_err("UBI error: cannot initialize UBI, error %d", err
);
1040 module_init(ubi_init
);
1042 void __exit
ubi_exit(void)
1046 for (i
= 0; i
< UBI_MAX_DEVICES
; i
++)
1047 if (ubi_devices
[i
]) {
1048 mutex_lock(&ubi_devices_mutex
);
1049 ubi_detach_mtd_dev(ubi_devices
[i
]->ubi_num
, 1);
1050 mutex_unlock(&ubi_devices_mutex
);
1052 kmem_cache_destroy(ubi_wl_entry_slab
);
1053 misc_deregister(&ubi_ctrl_cdev
);
1054 class_remove_file(ubi_class
, &ubi_version
);
1055 class_destroy(ubi_class
);
1058 module_exit(ubi_exit
);
1061 * bytes_str_to_int - convert a string representing number of bytes to an
1063 * @str: the string to convert
1065 * This function returns positive resulting integer in case of success and a
1066 * negative error code in case of failure.
1068 static int __init
bytes_str_to_int(const char *str
)
1071 unsigned long result
;
1073 result
= simple_strtoul(str
, &endp
, 0);
1074 if (str
== endp
|| result
< 0) {
1075 printk(KERN_ERR
"UBI error: incorrect bytes count: \"%s\"\n",
1087 if (endp
[1] == 'i' && endp
[2] == 'B')
1092 printk(KERN_ERR
"UBI error: incorrect bytes count: \"%s\"\n",
1101 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1102 * @val: the parameter value to parse
1105 * This function returns zero in case of success and a negative error code in
1108 int __init
ubi_mtd_param_parse(const char *val
, struct kernel_param
*kp
)
1111 struct mtd_dev_param
*p
;
1112 char buf
[MTD_PARAM_LEN_MAX
];
1113 char *pbuf
= &buf
[0];
1114 char *tokens
[2] = {NULL
, NULL
};
1119 if (mtd_devs
== UBI_MAX_DEVICES
) {
1120 printk(KERN_ERR
"UBI error: too many parameters, max. is %d\n",
1125 len
= strnlen(val
, MTD_PARAM_LEN_MAX
);
1126 if (len
== MTD_PARAM_LEN_MAX
) {
1127 printk(KERN_ERR
"UBI error: parameter \"%s\" is too long, "
1128 "max. is %d\n", val
, MTD_PARAM_LEN_MAX
);
1133 printk(KERN_WARNING
"UBI warning: empty 'mtd=' parameter - "
1140 /* Get rid of the final newline */
1141 if (buf
[len
- 1] == '\n')
1142 buf
[len
- 1] = '\0';
1144 for (i
= 0; i
< 2; i
++)
1145 tokens
[i
] = strsep(&pbuf
, ",");
1148 printk(KERN_ERR
"UBI error: too many arguments at \"%s\"\n",
1153 p
= &mtd_dev_param
[mtd_devs
];
1154 strcpy(&p
->name
[0], tokens
[0]);
1157 p
->vid_hdr_offs
= bytes_str_to_int(tokens
[1]);
1159 if (p
->vid_hdr_offs
< 0)
1160 return p
->vid_hdr_offs
;
1166 module_param_call(mtd
, ubi_mtd_param_parse
, NULL
, NULL
, 000);
1167 MODULE_PARM_DESC(mtd
, "MTD devices to attach. Parameter format: "
1168 "mtd=<name|num>[,<vid_hdr_offs>].\n"
1169 "Multiple \"mtd\" parameters may be specified.\n"
1170 "MTD devices may be specified by their number or name.\n"
1171 "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
1172 "header position and data starting position to be used "
1174 "Example: mtd=content,1984 mtd=4 - attach MTD device"
1175 "with name \"content\" using VID header offset 1984, and "
1176 "MTD device number 4 with default VID header offset.");
1178 MODULE_VERSION(__stringify(UBI_VERSION
));
1179 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1180 MODULE_AUTHOR("Artem Bityutskiy");
1181 MODULE_LICENSE("GPL");