2 * Core registration and callback routines for MTD
5 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
6 * Copyright © 2006 Red Hat UK Limited
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
24 #include <linux/module.h>
25 #include <linux/kernel.h>
26 #include <linux/ptrace.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/timer.h>
30 #include <linux/major.h>
32 #include <linux/err.h>
33 #include <linux/ioctl.h>
34 #include <linux/init.h>
36 #include <linux/proc_fs.h>
37 #include <linux/idr.h>
38 #include <linux/backing-dev.h>
39 #include <linux/gfp.h>
40 #include <linux/slab.h>
41 #include <linux/reboot.h>
42 #include <linux/kconfig.h>
43 #include <linux/leds.h>
45 #include <linux/mtd/mtd.h>
46 #include <linux/mtd/partitions.h>
50 static struct backing_dev_info mtd_bdi
= {
53 #ifdef CONFIG_PM_SLEEP
55 static int mtd_cls_suspend(struct device
*dev
)
57 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
59 return mtd
? mtd_suspend(mtd
) : 0;
62 static int mtd_cls_resume(struct device
*dev
)
64 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
71 static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops
, mtd_cls_suspend
, mtd_cls_resume
);
72 #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
74 #define MTD_CLS_PM_OPS NULL
77 static struct class mtd_class
= {
83 static DEFINE_IDR(mtd_idr
);
85 /* These are exported solely for the purpose of mtd_blkdevs.c. You
86 should not use them for _anything_ else */
87 DEFINE_MUTEX(mtd_table_mutex
);
88 EXPORT_SYMBOL_GPL(mtd_table_mutex
);
90 struct mtd_info
*__mtd_next_device(int i
)
92 return idr_get_next(&mtd_idr
, &i
);
94 EXPORT_SYMBOL_GPL(__mtd_next_device
);
96 static LIST_HEAD(mtd_notifiers
);
99 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
101 /* REVISIT once MTD uses the driver model better, whoever allocates
102 * the mtd_info will probably want to use the release() hook...
104 static void mtd_release(struct device
*dev
)
106 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
107 dev_t index
= MTD_DEVT(mtd
->index
);
109 /* remove /dev/mtdXro node */
110 device_destroy(&mtd_class
, index
+ 1);
113 static ssize_t
mtd_type_show(struct device
*dev
,
114 struct device_attribute
*attr
, char *buf
)
116 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
141 case MTD_MLCNANDFLASH
:
148 return snprintf(buf
, PAGE_SIZE
, "%s\n", type
);
150 static DEVICE_ATTR(type
, S_IRUGO
, mtd_type_show
, NULL
);
152 static ssize_t
mtd_flags_show(struct device
*dev
,
153 struct device_attribute
*attr
, char *buf
)
155 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
157 return snprintf(buf
, PAGE_SIZE
, "0x%lx\n", (unsigned long)mtd
->flags
);
160 static DEVICE_ATTR(flags
, S_IRUGO
, mtd_flags_show
, NULL
);
162 static ssize_t
mtd_size_show(struct device
*dev
,
163 struct device_attribute
*attr
, char *buf
)
165 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
167 return snprintf(buf
, PAGE_SIZE
, "%llu\n",
168 (unsigned long long)mtd
->size
);
171 static DEVICE_ATTR(size
, S_IRUGO
, mtd_size_show
, NULL
);
173 static ssize_t
mtd_erasesize_show(struct device
*dev
,
174 struct device_attribute
*attr
, char *buf
)
176 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
178 return snprintf(buf
, PAGE_SIZE
, "%lu\n", (unsigned long)mtd
->erasesize
);
181 static DEVICE_ATTR(erasesize
, S_IRUGO
, mtd_erasesize_show
, NULL
);
183 static ssize_t
mtd_writesize_show(struct device
*dev
,
184 struct device_attribute
*attr
, char *buf
)
186 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
188 return snprintf(buf
, PAGE_SIZE
, "%lu\n", (unsigned long)mtd
->writesize
);
191 static DEVICE_ATTR(writesize
, S_IRUGO
, mtd_writesize_show
, NULL
);
193 static ssize_t
mtd_subpagesize_show(struct device
*dev
,
194 struct device_attribute
*attr
, char *buf
)
196 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
197 unsigned int subpagesize
= mtd
->writesize
>> mtd
->subpage_sft
;
199 return snprintf(buf
, PAGE_SIZE
, "%u\n", subpagesize
);
202 static DEVICE_ATTR(subpagesize
, S_IRUGO
, mtd_subpagesize_show
, NULL
);
204 static ssize_t
mtd_oobsize_show(struct device
*dev
,
205 struct device_attribute
*attr
, char *buf
)
207 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
209 return snprintf(buf
, PAGE_SIZE
, "%lu\n", (unsigned long)mtd
->oobsize
);
212 static DEVICE_ATTR(oobsize
, S_IRUGO
, mtd_oobsize_show
, NULL
);
214 static ssize_t
mtd_numeraseregions_show(struct device
*dev
,
215 struct device_attribute
*attr
, char *buf
)
217 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
219 return snprintf(buf
, PAGE_SIZE
, "%u\n", mtd
->numeraseregions
);
222 static DEVICE_ATTR(numeraseregions
, S_IRUGO
, mtd_numeraseregions_show
,
225 static ssize_t
mtd_name_show(struct device
*dev
,
226 struct device_attribute
*attr
, char *buf
)
228 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
230 return snprintf(buf
, PAGE_SIZE
, "%s\n", mtd
->name
);
233 static DEVICE_ATTR(name
, S_IRUGO
, mtd_name_show
, NULL
);
235 static ssize_t
mtd_ecc_strength_show(struct device
*dev
,
236 struct device_attribute
*attr
, char *buf
)
238 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
240 return snprintf(buf
, PAGE_SIZE
, "%u\n", mtd
->ecc_strength
);
242 static DEVICE_ATTR(ecc_strength
, S_IRUGO
, mtd_ecc_strength_show
, NULL
);
244 static ssize_t
mtd_bitflip_threshold_show(struct device
*dev
,
245 struct device_attribute
*attr
,
248 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
250 return snprintf(buf
, PAGE_SIZE
, "%u\n", mtd
->bitflip_threshold
);
253 static ssize_t
mtd_bitflip_threshold_store(struct device
*dev
,
254 struct device_attribute
*attr
,
255 const char *buf
, size_t count
)
257 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
258 unsigned int bitflip_threshold
;
261 retval
= kstrtouint(buf
, 0, &bitflip_threshold
);
265 mtd
->bitflip_threshold
= bitflip_threshold
;
268 static DEVICE_ATTR(bitflip_threshold
, S_IRUGO
| S_IWUSR
,
269 mtd_bitflip_threshold_show
,
270 mtd_bitflip_threshold_store
);
272 static ssize_t
mtd_ecc_step_size_show(struct device
*dev
,
273 struct device_attribute
*attr
, char *buf
)
275 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
277 return snprintf(buf
, PAGE_SIZE
, "%u\n", mtd
->ecc_step_size
);
280 static DEVICE_ATTR(ecc_step_size
, S_IRUGO
, mtd_ecc_step_size_show
, NULL
);
282 static ssize_t
mtd_ecc_stats_corrected_show(struct device
*dev
,
283 struct device_attribute
*attr
, char *buf
)
285 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
286 struct mtd_ecc_stats
*ecc_stats
= &mtd
->ecc_stats
;
288 return snprintf(buf
, PAGE_SIZE
, "%u\n", ecc_stats
->corrected
);
290 static DEVICE_ATTR(corrected_bits
, S_IRUGO
,
291 mtd_ecc_stats_corrected_show
, NULL
);
293 static ssize_t
mtd_ecc_stats_errors_show(struct device
*dev
,
294 struct device_attribute
*attr
, char *buf
)
296 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
297 struct mtd_ecc_stats
*ecc_stats
= &mtd
->ecc_stats
;
299 return snprintf(buf
, PAGE_SIZE
, "%u\n", ecc_stats
->failed
);
301 static DEVICE_ATTR(ecc_failures
, S_IRUGO
, mtd_ecc_stats_errors_show
, NULL
);
303 static ssize_t
mtd_badblocks_show(struct device
*dev
,
304 struct device_attribute
*attr
, char *buf
)
306 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
307 struct mtd_ecc_stats
*ecc_stats
= &mtd
->ecc_stats
;
309 return snprintf(buf
, PAGE_SIZE
, "%u\n", ecc_stats
->badblocks
);
311 static DEVICE_ATTR(bad_blocks
, S_IRUGO
, mtd_badblocks_show
, NULL
);
313 static ssize_t
mtd_bbtblocks_show(struct device
*dev
,
314 struct device_attribute
*attr
, char *buf
)
316 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
317 struct mtd_ecc_stats
*ecc_stats
= &mtd
->ecc_stats
;
319 return snprintf(buf
, PAGE_SIZE
, "%u\n", ecc_stats
->bbtblocks
);
321 static DEVICE_ATTR(bbt_blocks
, S_IRUGO
, mtd_bbtblocks_show
, NULL
);
323 static struct attribute
*mtd_attrs
[] = {
325 &dev_attr_flags
.attr
,
327 &dev_attr_erasesize
.attr
,
328 &dev_attr_writesize
.attr
,
329 &dev_attr_subpagesize
.attr
,
330 &dev_attr_oobsize
.attr
,
331 &dev_attr_numeraseregions
.attr
,
333 &dev_attr_ecc_strength
.attr
,
334 &dev_attr_ecc_step_size
.attr
,
335 &dev_attr_corrected_bits
.attr
,
336 &dev_attr_ecc_failures
.attr
,
337 &dev_attr_bad_blocks
.attr
,
338 &dev_attr_bbt_blocks
.attr
,
339 &dev_attr_bitflip_threshold
.attr
,
342 ATTRIBUTE_GROUPS(mtd
);
344 static struct device_type mtd_devtype
= {
346 .groups
= mtd_groups
,
347 .release
= mtd_release
,
351 unsigned mtd_mmap_capabilities(struct mtd_info
*mtd
)
355 return NOMMU_MAP_COPY
| NOMMU_MAP_DIRECT
| NOMMU_MAP_EXEC
|
356 NOMMU_MAP_READ
| NOMMU_MAP_WRITE
;
358 return NOMMU_MAP_COPY
| NOMMU_MAP_DIRECT
| NOMMU_MAP_EXEC
|
361 return NOMMU_MAP_COPY
;
364 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities
);
367 static int mtd_reboot_notifier(struct notifier_block
*n
, unsigned long state
,
370 struct mtd_info
*mtd
;
372 mtd
= container_of(n
, struct mtd_info
, reboot_notifier
);
379 * add_mtd_device - register an MTD device
380 * @mtd: pointer to new MTD device info structure
382 * Add a device to the list of MTD devices present in the system, and
383 * notify each currently active MTD 'user' of its arrival. Returns
384 * zero on success or non-zero on failure.
387 int add_mtd_device(struct mtd_info
*mtd
)
389 struct mtd_notifier
*not;
393 * May occur, for instance, on buggy drivers which call
394 * mtd_device_parse_register() multiple times on the same master MTD,
395 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
397 if (WARN_ONCE(mtd
->backing_dev_info
, "MTD already registered\n"))
400 mtd
->backing_dev_info
= &mtd_bdi
;
402 BUG_ON(mtd
->writesize
== 0);
403 mutex_lock(&mtd_table_mutex
);
405 i
= idr_alloc(&mtd_idr
, mtd
, 0, 0, GFP_KERNEL
);
414 /* default value if not set by driver */
415 if (mtd
->bitflip_threshold
== 0)
416 mtd
->bitflip_threshold
= mtd
->ecc_strength
;
418 if (is_power_of_2(mtd
->erasesize
))
419 mtd
->erasesize_shift
= ffs(mtd
->erasesize
) - 1;
421 mtd
->erasesize_shift
= 0;
423 if (is_power_of_2(mtd
->writesize
))
424 mtd
->writesize_shift
= ffs(mtd
->writesize
) - 1;
426 mtd
->writesize_shift
= 0;
428 mtd
->erasesize_mask
= (1 << mtd
->erasesize_shift
) - 1;
429 mtd
->writesize_mask
= (1 << mtd
->writesize_shift
) - 1;
431 /* Some chips always power up locked. Unlock them now */
432 if ((mtd
->flags
& MTD_WRITEABLE
) && (mtd
->flags
& MTD_POWERUP_LOCK
)) {
433 error
= mtd_unlock(mtd
, 0, mtd
->size
);
434 if (error
&& error
!= -EOPNOTSUPP
)
436 "%s: unlock failed, writes may not work\n",
438 /* Ignore unlock failures? */
442 /* Caller should have set dev.parent to match the
443 * physical device, if appropriate.
445 mtd
->dev
.type
= &mtd_devtype
;
446 mtd
->dev
.class = &mtd_class
;
447 mtd
->dev
.devt
= MTD_DEVT(i
);
448 dev_set_name(&mtd
->dev
, "mtd%d", i
);
449 dev_set_drvdata(&mtd
->dev
, mtd
);
450 of_node_get(mtd_get_of_node(mtd
));
451 error
= device_register(&mtd
->dev
);
455 device_create(&mtd_class
, mtd
->dev
.parent
, MTD_DEVT(i
) + 1, NULL
,
458 pr_debug("mtd: Giving out device %d to %s\n", i
, mtd
->name
);
459 /* No need to get a refcount on the module containing
460 the notifier, since we hold the mtd_table_mutex */
461 list_for_each_entry(not, &mtd_notifiers
, list
)
464 mutex_unlock(&mtd_table_mutex
);
465 /* We _know_ we aren't being removed, because
466 our caller is still holding us here. So none
467 of this try_ nonsense, and no bitching about it
469 __module_get(THIS_MODULE
);
473 of_node_put(mtd_get_of_node(mtd
));
474 idr_remove(&mtd_idr
, i
);
476 mutex_unlock(&mtd_table_mutex
);
481 * del_mtd_device - unregister an MTD device
482 * @mtd: pointer to MTD device info structure
484 * Remove a device from the list of MTD devices present in the system,
485 * and notify each currently active MTD 'user' of its departure.
486 * Returns zero on success or 1 on failure, which currently will happen
487 * if the requested device does not appear to be present in the list.
490 int del_mtd_device(struct mtd_info
*mtd
)
493 struct mtd_notifier
*not;
495 mutex_lock(&mtd_table_mutex
);
497 if (idr_find(&mtd_idr
, mtd
->index
) != mtd
) {
502 /* No need to get a refcount on the module containing
503 the notifier, since we hold the mtd_table_mutex */
504 list_for_each_entry(not, &mtd_notifiers
, list
)
508 printk(KERN_NOTICE
"Removing MTD device #%d (%s) with use count %d\n",
509 mtd
->index
, mtd
->name
, mtd
->usecount
);
512 device_unregister(&mtd
->dev
);
514 idr_remove(&mtd_idr
, mtd
->index
);
515 of_node_put(mtd_get_of_node(mtd
));
517 module_put(THIS_MODULE
);
522 mutex_unlock(&mtd_table_mutex
);
526 static int mtd_add_device_partitions(struct mtd_info
*mtd
,
527 struct mtd_partitions
*parts
)
529 const struct mtd_partition
*real_parts
= parts
->parts
;
530 int nbparts
= parts
->nr_parts
;
533 if (nbparts
== 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER
)) {
534 ret
= add_mtd_device(mtd
);
540 ret
= add_mtd_partitions(mtd
, real_parts
, nbparts
);
541 if (ret
&& IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER
))
550 * Set a few defaults based on the parent devices, if not provided by the
553 static void mtd_set_dev_defaults(struct mtd_info
*mtd
)
555 if (mtd
->dev
.parent
) {
556 if (!mtd
->owner
&& mtd
->dev
.parent
->driver
)
557 mtd
->owner
= mtd
->dev
.parent
->driver
->owner
;
559 mtd
->name
= dev_name(mtd
->dev
.parent
);
561 pr_debug("mtd device won't show a device symlink in sysfs\n");
566 * mtd_device_parse_register - parse partitions and register an MTD device.
568 * @mtd: the MTD device to register
569 * @types: the list of MTD partition probes to try, see
570 * 'parse_mtd_partitions()' for more information
571 * @parser_data: MTD partition parser-specific data
572 * @parts: fallback partition information to register, if parsing fails;
573 * only valid if %nr_parts > %0
574 * @nr_parts: the number of partitions in parts, if zero then the full
575 * MTD device is registered if no partition info is found
577 * This function aggregates MTD partitions parsing (done by
578 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
579 * basically follows the most common pattern found in many MTD drivers:
581 * * It first tries to probe partitions on MTD device @mtd using parsers
582 * specified in @types (if @types is %NULL, then the default list of parsers
583 * is used, see 'parse_mtd_partitions()' for more information). If none are
584 * found this functions tries to fallback to information specified in
586 * * If any partitioning info was found, this function registers the found
587 * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
588 * as a whole is registered first.
589 * * If no partitions were found this function just registers the MTD device
592 * Returns zero in case of success and a negative error code in case of failure.
594 int mtd_device_parse_register(struct mtd_info
*mtd
, const char * const *types
,
595 struct mtd_part_parser_data
*parser_data
,
596 const struct mtd_partition
*parts
,
599 struct mtd_partitions parsed
;
602 mtd_set_dev_defaults(mtd
);
604 memset(&parsed
, 0, sizeof(parsed
));
606 ret
= parse_mtd_partitions(mtd
, types
, &parsed
, parser_data
);
607 if ((ret
< 0 || parsed
.nr_parts
== 0) && parts
&& nr_parts
) {
608 /* Fall back to driver-provided partitions */
609 parsed
= (struct mtd_partitions
){
611 .nr_parts
= nr_parts
,
613 } else if (ret
< 0) {
614 /* Didn't come up with parsed OR fallback partitions */
615 pr_info("mtd: failed to find partitions; one or more parsers reports errors (%d)\n",
617 /* Don't abort on errors; we can still use unpartitioned MTD */
618 memset(&parsed
, 0, sizeof(parsed
));
621 ret
= mtd_add_device_partitions(mtd
, &parsed
);
626 * FIXME: some drivers unfortunately call this function more than once.
627 * So we have to check if we've already assigned the reboot notifier.
629 * Generally, we can make multiple calls work for most cases, but it
630 * does cause problems with parse_mtd_partitions() above (e.g.,
631 * cmdlineparts will register partitions more than once).
633 WARN_ONCE(mtd
->_reboot
&& mtd
->reboot_notifier
.notifier_call
,
634 "MTD already registered\n");
635 if (mtd
->_reboot
&& !mtd
->reboot_notifier
.notifier_call
) {
636 mtd
->reboot_notifier
.notifier_call
= mtd_reboot_notifier
;
637 register_reboot_notifier(&mtd
->reboot_notifier
);
641 /* Cleanup any parsed partitions */
642 mtd_part_parser_cleanup(&parsed
);
645 EXPORT_SYMBOL_GPL(mtd_device_parse_register
);
648 * mtd_device_unregister - unregister an existing MTD device.
650 * @master: the MTD device to unregister. This will unregister both the master
651 * and any partitions if registered.
653 int mtd_device_unregister(struct mtd_info
*master
)
658 unregister_reboot_notifier(&master
->reboot_notifier
);
660 err
= del_mtd_partitions(master
);
664 if (!device_is_registered(&master
->dev
))
667 return del_mtd_device(master
);
669 EXPORT_SYMBOL_GPL(mtd_device_unregister
);
672 * register_mtd_user - register a 'user' of MTD devices.
673 * @new: pointer to notifier info structure
675 * Registers a pair of callbacks function to be called upon addition
676 * or removal of MTD devices. Causes the 'add' callback to be immediately
677 * invoked for each MTD device currently present in the system.
679 void register_mtd_user (struct mtd_notifier
*new)
681 struct mtd_info
*mtd
;
683 mutex_lock(&mtd_table_mutex
);
685 list_add(&new->list
, &mtd_notifiers
);
687 __module_get(THIS_MODULE
);
689 mtd_for_each_device(mtd
)
692 mutex_unlock(&mtd_table_mutex
);
694 EXPORT_SYMBOL_GPL(register_mtd_user
);
697 * unregister_mtd_user - unregister a 'user' of MTD devices.
698 * @old: pointer to notifier info structure
700 * Removes a callback function pair from the list of 'users' to be
701 * notified upon addition or removal of MTD devices. Causes the
702 * 'remove' callback to be immediately invoked for each MTD device
703 * currently present in the system.
705 int unregister_mtd_user (struct mtd_notifier
*old
)
707 struct mtd_info
*mtd
;
709 mutex_lock(&mtd_table_mutex
);
711 module_put(THIS_MODULE
);
713 mtd_for_each_device(mtd
)
716 list_del(&old
->list
);
717 mutex_unlock(&mtd_table_mutex
);
720 EXPORT_SYMBOL_GPL(unregister_mtd_user
);
723 * get_mtd_device - obtain a validated handle for an MTD device
724 * @mtd: last known address of the required MTD device
725 * @num: internal device number of the required MTD device
727 * Given a number and NULL address, return the num'th entry in the device
728 * table, if any. Given an address and num == -1, search the device table
729 * for a device with that address and return if it's still present. Given
730 * both, return the num'th driver only if its address matches. Return
733 struct mtd_info
*get_mtd_device(struct mtd_info
*mtd
, int num
)
735 struct mtd_info
*ret
= NULL
, *other
;
738 mutex_lock(&mtd_table_mutex
);
741 mtd_for_each_device(other
) {
747 } else if (num
>= 0) {
748 ret
= idr_find(&mtd_idr
, num
);
749 if (mtd
&& mtd
!= ret
)
758 err
= __get_mtd_device(ret
);
762 mutex_unlock(&mtd_table_mutex
);
765 EXPORT_SYMBOL_GPL(get_mtd_device
);
768 int __get_mtd_device(struct mtd_info
*mtd
)
772 if (!try_module_get(mtd
->owner
))
775 if (mtd
->_get_device
) {
776 err
= mtd
->_get_device(mtd
);
779 module_put(mtd
->owner
);
786 EXPORT_SYMBOL_GPL(__get_mtd_device
);
789 * get_mtd_device_nm - obtain a validated handle for an MTD device by
791 * @name: MTD device name to open
793 * This function returns MTD device description structure in case of
794 * success and an error code in case of failure.
796 struct mtd_info
*get_mtd_device_nm(const char *name
)
799 struct mtd_info
*mtd
= NULL
, *other
;
801 mutex_lock(&mtd_table_mutex
);
803 mtd_for_each_device(other
) {
804 if (!strcmp(name
, other
->name
)) {
813 err
= __get_mtd_device(mtd
);
817 mutex_unlock(&mtd_table_mutex
);
821 mutex_unlock(&mtd_table_mutex
);
824 EXPORT_SYMBOL_GPL(get_mtd_device_nm
);
826 void put_mtd_device(struct mtd_info
*mtd
)
828 mutex_lock(&mtd_table_mutex
);
829 __put_mtd_device(mtd
);
830 mutex_unlock(&mtd_table_mutex
);
833 EXPORT_SYMBOL_GPL(put_mtd_device
);
835 void __put_mtd_device(struct mtd_info
*mtd
)
838 BUG_ON(mtd
->usecount
< 0);
840 if (mtd
->_put_device
)
841 mtd
->_put_device(mtd
);
843 module_put(mtd
->owner
);
845 EXPORT_SYMBOL_GPL(__put_mtd_device
);
848 * Erase is an asynchronous operation. Device drivers are supposed
849 * to call instr->callback() whenever the operation completes, even
850 * if it completes with a failure.
851 * Callers are supposed to pass a callback function and wait for it
852 * to be called before writing to the block.
854 int mtd_erase(struct mtd_info
*mtd
, struct erase_info
*instr
)
856 if (instr
->addr
>= mtd
->size
|| instr
->len
> mtd
->size
- instr
->addr
)
858 if (!(mtd
->flags
& MTD_WRITEABLE
))
860 instr
->fail_addr
= MTD_FAIL_ADDR_UNKNOWN
;
862 instr
->state
= MTD_ERASE_DONE
;
863 mtd_erase_callback(instr
);
866 ledtrig_mtd_activity();
867 return mtd
->_erase(mtd
, instr
);
869 EXPORT_SYMBOL_GPL(mtd_erase
);
872 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
874 int mtd_point(struct mtd_info
*mtd
, loff_t from
, size_t len
, size_t *retlen
,
875 void **virt
, resource_size_t
*phys
)
883 if (from
< 0 || from
>= mtd
->size
|| len
> mtd
->size
- from
)
887 return mtd
->_point(mtd
, from
, len
, retlen
, virt
, phys
);
889 EXPORT_SYMBOL_GPL(mtd_point
);
891 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
892 int mtd_unpoint(struct mtd_info
*mtd
, loff_t from
, size_t len
)
896 if (from
< 0 || from
>= mtd
->size
|| len
> mtd
->size
- from
)
900 return mtd
->_unpoint(mtd
, from
, len
);
902 EXPORT_SYMBOL_GPL(mtd_unpoint
);
905 * Allow NOMMU mmap() to directly map the device (if not NULL)
906 * - return the address to which the offset maps
907 * - return -ENOSYS to indicate refusal to do the mapping
909 unsigned long mtd_get_unmapped_area(struct mtd_info
*mtd
, unsigned long len
,
910 unsigned long offset
, unsigned long flags
)
912 if (!mtd
->_get_unmapped_area
)
914 if (offset
>= mtd
->size
|| len
> mtd
->size
- offset
)
916 return mtd
->_get_unmapped_area(mtd
, len
, offset
, flags
);
918 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area
);
920 int mtd_read(struct mtd_info
*mtd
, loff_t from
, size_t len
, size_t *retlen
,
925 if (from
< 0 || from
>= mtd
->size
|| len
> mtd
->size
- from
)
930 ledtrig_mtd_activity();
932 * In the absence of an error, drivers return a non-negative integer
933 * representing the maximum number of bitflips that were corrected on
934 * any one ecc region (if applicable; zero otherwise).
936 ret_code
= mtd
->_read(mtd
, from
, len
, retlen
, buf
);
937 if (unlikely(ret_code
< 0))
939 if (mtd
->ecc_strength
== 0)
940 return 0; /* device lacks ecc */
941 return ret_code
>= mtd
->bitflip_threshold
? -EUCLEAN
: 0;
943 EXPORT_SYMBOL_GPL(mtd_read
);
945 int mtd_write(struct mtd_info
*mtd
, loff_t to
, size_t len
, size_t *retlen
,
949 if (to
< 0 || to
>= mtd
->size
|| len
> mtd
->size
- to
)
951 if (!mtd
->_write
|| !(mtd
->flags
& MTD_WRITEABLE
))
955 ledtrig_mtd_activity();
956 return mtd
->_write(mtd
, to
, len
, retlen
, buf
);
958 EXPORT_SYMBOL_GPL(mtd_write
);
961 * In blackbox flight recorder like scenarios we want to make successful writes
962 * in interrupt context. panic_write() is only intended to be called when its
963 * known the kernel is about to panic and we need the write to succeed. Since
964 * the kernel is not going to be running for much longer, this function can
965 * break locks and delay to ensure the write succeeds (but not sleep).
967 int mtd_panic_write(struct mtd_info
*mtd
, loff_t to
, size_t len
, size_t *retlen
,
971 if (!mtd
->_panic_write
)
973 if (to
< 0 || to
>= mtd
->size
|| len
> mtd
->size
- to
)
975 if (!(mtd
->flags
& MTD_WRITEABLE
))
979 return mtd
->_panic_write(mtd
, to
, len
, retlen
, buf
);
981 EXPORT_SYMBOL_GPL(mtd_panic_write
);
983 int mtd_read_oob(struct mtd_info
*mtd
, loff_t from
, struct mtd_oob_ops
*ops
)
986 ops
->retlen
= ops
->oobretlen
= 0;
990 ledtrig_mtd_activity();
992 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
993 * similar to mtd->_read(), returning a non-negative integer
994 * representing max bitflips. In other cases, mtd->_read_oob() may
995 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
997 ret_code
= mtd
->_read_oob(mtd
, from
, ops
);
998 if (unlikely(ret_code
< 0))
1000 if (mtd
->ecc_strength
== 0)
1001 return 0; /* device lacks ecc */
1002 return ret_code
>= mtd
->bitflip_threshold
? -EUCLEAN
: 0;
1004 EXPORT_SYMBOL_GPL(mtd_read_oob
);
1006 int mtd_write_oob(struct mtd_info
*mtd
, loff_t to
,
1007 struct mtd_oob_ops
*ops
)
1009 ops
->retlen
= ops
->oobretlen
= 0;
1010 if (!mtd
->_write_oob
)
1012 if (!(mtd
->flags
& MTD_WRITEABLE
))
1014 ledtrig_mtd_activity();
1015 return mtd
->_write_oob(mtd
, to
, ops
);
1017 EXPORT_SYMBOL_GPL(mtd_write_oob
);
1020 * Method to access the protection register area, present in some flash
1021 * devices. The user data is one time programmable but the factory data is read
1024 int mtd_get_fact_prot_info(struct mtd_info
*mtd
, size_t len
, size_t *retlen
,
1025 struct otp_info
*buf
)
1027 if (!mtd
->_get_fact_prot_info
)
1031 return mtd
->_get_fact_prot_info(mtd
, len
, retlen
, buf
);
1033 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info
);
1035 int mtd_read_fact_prot_reg(struct mtd_info
*mtd
, loff_t from
, size_t len
,
1036 size_t *retlen
, u_char
*buf
)
1039 if (!mtd
->_read_fact_prot_reg
)
1043 return mtd
->_read_fact_prot_reg(mtd
, from
, len
, retlen
, buf
);
1045 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg
);
1047 int mtd_get_user_prot_info(struct mtd_info
*mtd
, size_t len
, size_t *retlen
,
1048 struct otp_info
*buf
)
1050 if (!mtd
->_get_user_prot_info
)
1054 return mtd
->_get_user_prot_info(mtd
, len
, retlen
, buf
);
1056 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info
);
1058 int mtd_read_user_prot_reg(struct mtd_info
*mtd
, loff_t from
, size_t len
,
1059 size_t *retlen
, u_char
*buf
)
1062 if (!mtd
->_read_user_prot_reg
)
1066 return mtd
->_read_user_prot_reg(mtd
, from
, len
, retlen
, buf
);
1068 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg
);
1070 int mtd_write_user_prot_reg(struct mtd_info
*mtd
, loff_t to
, size_t len
,
1071 size_t *retlen
, u_char
*buf
)
1076 if (!mtd
->_write_user_prot_reg
)
1080 ret
= mtd
->_write_user_prot_reg(mtd
, to
, len
, retlen
, buf
);
1085 * If no data could be written at all, we are out of memory and
1086 * must return -ENOSPC.
1088 return (*retlen
) ? 0 : -ENOSPC
;
1090 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg
);
1092 int mtd_lock_user_prot_reg(struct mtd_info
*mtd
, loff_t from
, size_t len
)
1094 if (!mtd
->_lock_user_prot_reg
)
1098 return mtd
->_lock_user_prot_reg(mtd
, from
, len
);
1100 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg
);
1102 /* Chip-supported device locking */
1103 int mtd_lock(struct mtd_info
*mtd
, loff_t ofs
, uint64_t len
)
1107 if (ofs
< 0 || ofs
>= mtd
->size
|| len
> mtd
->size
- ofs
)
1111 return mtd
->_lock(mtd
, ofs
, len
);
1113 EXPORT_SYMBOL_GPL(mtd_lock
);
1115 int mtd_unlock(struct mtd_info
*mtd
, loff_t ofs
, uint64_t len
)
1119 if (ofs
< 0 || ofs
>= mtd
->size
|| len
> mtd
->size
- ofs
)
1123 return mtd
->_unlock(mtd
, ofs
, len
);
1125 EXPORT_SYMBOL_GPL(mtd_unlock
);
1127 int mtd_is_locked(struct mtd_info
*mtd
, loff_t ofs
, uint64_t len
)
1129 if (!mtd
->_is_locked
)
1131 if (ofs
< 0 || ofs
>= mtd
->size
|| len
> mtd
->size
- ofs
)
1135 return mtd
->_is_locked(mtd
, ofs
, len
);
1137 EXPORT_SYMBOL_GPL(mtd_is_locked
);
1139 int mtd_block_isreserved(struct mtd_info
*mtd
, loff_t ofs
)
1141 if (ofs
< 0 || ofs
>= mtd
->size
)
1143 if (!mtd
->_block_isreserved
)
1145 return mtd
->_block_isreserved(mtd
, ofs
);
1147 EXPORT_SYMBOL_GPL(mtd_block_isreserved
);
1149 int mtd_block_isbad(struct mtd_info
*mtd
, loff_t ofs
)
1151 if (ofs
< 0 || ofs
>= mtd
->size
)
1153 if (!mtd
->_block_isbad
)
1155 return mtd
->_block_isbad(mtd
, ofs
);
1157 EXPORT_SYMBOL_GPL(mtd_block_isbad
);
1159 int mtd_block_markbad(struct mtd_info
*mtd
, loff_t ofs
)
1161 if (!mtd
->_block_markbad
)
1163 if (ofs
< 0 || ofs
>= mtd
->size
)
1165 if (!(mtd
->flags
& MTD_WRITEABLE
))
1167 return mtd
->_block_markbad(mtd
, ofs
);
1169 EXPORT_SYMBOL_GPL(mtd_block_markbad
);
1172 * default_mtd_writev - the default writev method
1173 * @mtd: mtd device description object pointer
1174 * @vecs: the vectors to write
1175 * @count: count of vectors in @vecs
1176 * @to: the MTD device offset to write to
1177 * @retlen: on exit contains the count of bytes written to the MTD device.
1179 * This function returns zero in case of success and a negative error code in
1182 static int default_mtd_writev(struct mtd_info
*mtd
, const struct kvec
*vecs
,
1183 unsigned long count
, loff_t to
, size_t *retlen
)
1186 size_t totlen
= 0, thislen
;
1189 for (i
= 0; i
< count
; i
++) {
1190 if (!vecs
[i
].iov_len
)
1192 ret
= mtd_write(mtd
, to
, vecs
[i
].iov_len
, &thislen
,
1195 if (ret
|| thislen
!= vecs
[i
].iov_len
)
1197 to
+= vecs
[i
].iov_len
;
1204 * mtd_writev - the vector-based MTD write method
1205 * @mtd: mtd device description object pointer
1206 * @vecs: the vectors to write
1207 * @count: count of vectors in @vecs
1208 * @to: the MTD device offset to write to
1209 * @retlen: on exit contains the count of bytes written to the MTD device.
1211 * This function returns zero in case of success and a negative error code in
1214 int mtd_writev(struct mtd_info
*mtd
, const struct kvec
*vecs
,
1215 unsigned long count
, loff_t to
, size_t *retlen
)
1218 if (!(mtd
->flags
& MTD_WRITEABLE
))
1221 return default_mtd_writev(mtd
, vecs
, count
, to
, retlen
);
1222 return mtd
->_writev(mtd
, vecs
, count
, to
, retlen
);
1224 EXPORT_SYMBOL_GPL(mtd_writev
);
1227 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1228 * @mtd: mtd device description object pointer
1229 * @size: a pointer to the ideal or maximum size of the allocation, points
1230 * to the actual allocation size on success.
1232 * This routine attempts to allocate a contiguous kernel buffer up to
1233 * the specified size, backing off the size of the request exponentially
1234 * until the request succeeds or until the allocation size falls below
1235 * the system page size. This attempts to make sure it does not adversely
1236 * impact system performance, so when allocating more than one page, we
1237 * ask the memory allocator to avoid re-trying, swapping, writing back
1238 * or performing I/O.
1240 * Note, this function also makes sure that the allocated buffer is aligned to
1241 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1243 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1244 * to handle smaller (i.e. degraded) buffer allocations under low- or
1245 * fragmented-memory situations where such reduced allocations, from a
1246 * requested ideal, are allowed.
1248 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1250 void *mtd_kmalloc_up_to(const struct mtd_info
*mtd
, size_t *size
)
1252 gfp_t flags
= __GFP_NOWARN
| __GFP_DIRECT_RECLAIM
| __GFP_NORETRY
;
1253 size_t min_alloc
= max_t(size_t, mtd
->writesize
, PAGE_SIZE
);
1256 *size
= min_t(size_t, *size
, KMALLOC_MAX_SIZE
);
1258 while (*size
> min_alloc
) {
1259 kbuf
= kmalloc(*size
, flags
);
1264 *size
= ALIGN(*size
, mtd
->writesize
);
1268 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1269 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1271 return kmalloc(*size
, GFP_KERNEL
);
1273 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to
);
1275 #ifdef CONFIG_PROC_FS
1277 /*====================================================================*/
1278 /* Support for /proc/mtd */
1280 static int mtd_proc_show(struct seq_file
*m
, void *v
)
1282 struct mtd_info
*mtd
;
1284 seq_puts(m
, "dev: size erasesize name\n");
1285 mutex_lock(&mtd_table_mutex
);
1286 mtd_for_each_device(mtd
) {
1287 seq_printf(m
, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1288 mtd
->index
, (unsigned long long)mtd
->size
,
1289 mtd
->erasesize
, mtd
->name
);
1291 mutex_unlock(&mtd_table_mutex
);
1295 static int mtd_proc_open(struct inode
*inode
, struct file
*file
)
1297 return single_open(file
, mtd_proc_show
, NULL
);
1300 static const struct file_operations mtd_proc_ops
= {
1301 .open
= mtd_proc_open
,
1303 .llseek
= seq_lseek
,
1304 .release
= single_release
,
1306 #endif /* CONFIG_PROC_FS */
1308 /*====================================================================*/
1311 static int __init
mtd_bdi_init(struct backing_dev_info
*bdi
, const char *name
)
1315 ret
= bdi_init(bdi
);
1317 ret
= bdi_register(bdi
, NULL
, "%s", name
);
1325 static struct proc_dir_entry
*proc_mtd
;
1327 static int __init
init_mtd(void)
1331 ret
= class_register(&mtd_class
);
1335 ret
= mtd_bdi_init(&mtd_bdi
, "mtd");
1339 proc_mtd
= proc_create("mtd", 0, NULL
, &mtd_proc_ops
);
1341 ret
= init_mtdchar();
1349 remove_proc_entry("mtd", NULL
);
1351 class_unregister(&mtd_class
);
1353 pr_err("Error registering mtd class or bdi: %d\n", ret
);
1357 static void __exit
cleanup_mtd(void)
1361 remove_proc_entry("mtd", NULL
);
1362 class_unregister(&mtd_class
);
1363 bdi_destroy(&mtd_bdi
);
1364 idr_destroy(&mtd_idr
);
1367 module_init(init_mtd
);
1368 module_exit(cleanup_mtd
);
1370 MODULE_LICENSE("GPL");
1371 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1372 MODULE_DESCRIPTION("Core MTD registration and access routines");