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>
35 #include <linux/proc_fs.h>
36 #include <linux/idr.h>
37 #include <linux/backing-dev.h>
38 #include <linux/gfp.h>
39 #include <linux/slab.h>
40 #include <linux/reboot.h>
41 #include <linux/kconfig.h>
43 #include <linux/mtd/mtd.h>
44 #include <linux/mtd/partitions.h>
48 static struct backing_dev_info mtd_bdi = {
51 static int mtd_cls_suspend(struct device *dev, pm_message_t state);
52 static int mtd_cls_resume(struct device *dev);
54 static struct class mtd_class = {
57 .suspend = mtd_cls_suspend,
58 .resume = mtd_cls_resume,
61 static DEFINE_IDR(mtd_idr);
63 /* These are exported solely for the purpose of mtd_blkdevs.c. You
64 should not use them for _anything_ else */
65 DEFINE_MUTEX(mtd_table_mutex);
66 EXPORT_SYMBOL_GPL(mtd_table_mutex);
68 struct mtd_info *__mtd_next_device(int i)
70 return idr_get_next(&mtd_idr, &i);
72 EXPORT_SYMBOL_GPL(__mtd_next_device);
74 static LIST_HEAD(mtd_notifiers);
77 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
79 /* REVISIT once MTD uses the driver model better, whoever allocates
80 * the mtd_info will probably want to use the release() hook...
82 static void mtd_release(struct device *dev)
84 struct mtd_info *mtd = dev_get_drvdata(dev);
85 dev_t index = MTD_DEVT(mtd->index);
87 /* remove /dev/mtdXro node */
88 device_destroy(&mtd_class, index + 1);
91 static int mtd_cls_suspend(struct device *dev, pm_message_t state)
93 struct mtd_info *mtd = dev_get_drvdata(dev);
95 return mtd ? mtd_suspend(mtd) : 0;
98 static int mtd_cls_resume(struct device *dev)
100 struct mtd_info *mtd = dev_get_drvdata(dev);
107 static ssize_t mtd_type_show(struct device *dev,
108 struct device_attribute *attr, char *buf)
110 struct mtd_info *mtd = dev_get_drvdata(dev);
135 case MTD_MLCNANDFLASH:
142 return snprintf(buf, PAGE_SIZE, "%s\n", type);
144 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
146 static ssize_t mtd_flags_show(struct device *dev,
147 struct device_attribute *attr, char *buf)
149 struct mtd_info *mtd = dev_get_drvdata(dev);
151 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
154 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
156 static ssize_t mtd_size_show(struct device *dev,
157 struct device_attribute *attr, char *buf)
159 struct mtd_info *mtd = dev_get_drvdata(dev);
161 return snprintf(buf, PAGE_SIZE, "%llu\n",
162 (unsigned long long)mtd->size);
165 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
167 static ssize_t mtd_erasesize_show(struct device *dev,
168 struct device_attribute *attr, char *buf)
170 struct mtd_info *mtd = dev_get_drvdata(dev);
172 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
175 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
177 static ssize_t mtd_writesize_show(struct device *dev,
178 struct device_attribute *attr, char *buf)
180 struct mtd_info *mtd = dev_get_drvdata(dev);
182 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
185 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
187 static ssize_t mtd_subpagesize_show(struct device *dev,
188 struct device_attribute *attr, char *buf)
190 struct mtd_info *mtd = dev_get_drvdata(dev);
191 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
193 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
196 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
198 static ssize_t mtd_oobsize_show(struct device *dev,
199 struct device_attribute *attr, char *buf)
201 struct mtd_info *mtd = dev_get_drvdata(dev);
203 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
206 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
208 static ssize_t mtd_numeraseregions_show(struct device *dev,
209 struct device_attribute *attr, char *buf)
211 struct mtd_info *mtd = dev_get_drvdata(dev);
213 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
216 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
219 static ssize_t mtd_name_show(struct device *dev,
220 struct device_attribute *attr, char *buf)
222 struct mtd_info *mtd = dev_get_drvdata(dev);
224 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
227 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
229 static ssize_t mtd_ecc_strength_show(struct device *dev,
230 struct device_attribute *attr, char *buf)
232 struct mtd_info *mtd = dev_get_drvdata(dev);
234 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
236 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
238 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
239 struct device_attribute *attr,
242 struct mtd_info *mtd = dev_get_drvdata(dev);
244 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
247 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
248 struct device_attribute *attr,
249 const char *buf, size_t count)
251 struct mtd_info *mtd = dev_get_drvdata(dev);
252 unsigned int bitflip_threshold;
255 retval = kstrtouint(buf, 0, &bitflip_threshold);
259 mtd->bitflip_threshold = bitflip_threshold;
262 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
263 mtd_bitflip_threshold_show,
264 mtd_bitflip_threshold_store);
266 static ssize_t mtd_ecc_step_size_show(struct device *dev,
267 struct device_attribute *attr, char *buf)
269 struct mtd_info *mtd = dev_get_drvdata(dev);
271 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
274 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
276 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
277 struct device_attribute *attr, char *buf)
279 struct mtd_info *mtd = dev_get_drvdata(dev);
280 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
282 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
284 static DEVICE_ATTR(corrected_bits, S_IRUGO,
285 mtd_ecc_stats_corrected_show, NULL);
287 static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
288 struct device_attribute *attr, char *buf)
290 struct mtd_info *mtd = dev_get_drvdata(dev);
291 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
293 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
295 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
297 static ssize_t mtd_badblocks_show(struct device *dev,
298 struct device_attribute *attr, char *buf)
300 struct mtd_info *mtd = dev_get_drvdata(dev);
301 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
303 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
305 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
307 static ssize_t mtd_bbtblocks_show(struct device *dev,
308 struct device_attribute *attr, char *buf)
310 struct mtd_info *mtd = dev_get_drvdata(dev);
311 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
313 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
315 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
317 static struct attribute *mtd_attrs[] = {
319 &dev_attr_flags.attr,
321 &dev_attr_erasesize.attr,
322 &dev_attr_writesize.attr,
323 &dev_attr_subpagesize.attr,
324 &dev_attr_oobsize.attr,
325 &dev_attr_numeraseregions.attr,
327 &dev_attr_ecc_strength.attr,
328 &dev_attr_ecc_step_size.attr,
329 &dev_attr_corrected_bits.attr,
330 &dev_attr_ecc_failures.attr,
331 &dev_attr_bad_blocks.attr,
332 &dev_attr_bbt_blocks.attr,
333 &dev_attr_bitflip_threshold.attr,
336 ATTRIBUTE_GROUPS(mtd);
338 static struct device_type mtd_devtype = {
340 .groups = mtd_groups,
341 .release = mtd_release,
345 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
349 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
350 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
352 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
355 return NOMMU_MAP_COPY;
358 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
361 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
364 struct mtd_info *mtd;
366 mtd = container_of(n, struct mtd_info, reboot_notifier);
373 * add_mtd_device - register an MTD device
374 * @mtd: pointer to new MTD device info structure
376 * Add a device to the list of MTD devices present in the system, and
377 * notify each currently active MTD 'user' of its arrival. Returns
378 * zero on success or 1 on failure, which currently will only happen
379 * if there is insufficient memory or a sysfs error.
382 int add_mtd_device(struct mtd_info *mtd)
384 struct mtd_notifier *not;
387 mtd->backing_dev_info = &mtd_bdi;
389 BUG_ON(mtd->writesize == 0);
390 mutex_lock(&mtd_table_mutex);
392 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
399 /* default value if not set by driver */
400 if (mtd->bitflip_threshold == 0)
401 mtd->bitflip_threshold = mtd->ecc_strength;
403 if (is_power_of_2(mtd->erasesize))
404 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
406 mtd->erasesize_shift = 0;
408 if (is_power_of_2(mtd->writesize))
409 mtd->writesize_shift = ffs(mtd->writesize) - 1;
411 mtd->writesize_shift = 0;
413 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
414 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
416 /* Some chips always power up locked. Unlock them now */
417 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
418 error = mtd_unlock(mtd, 0, mtd->size);
419 if (error && error != -EOPNOTSUPP)
421 "%s: unlock failed, writes may not work\n",
425 /* Caller should have set dev.parent to match the
428 mtd->dev.type = &mtd_devtype;
429 mtd->dev.class = &mtd_class;
430 mtd->dev.devt = MTD_DEVT(i);
431 dev_set_name(&mtd->dev, "mtd%d", i);
432 dev_set_drvdata(&mtd->dev, mtd);
433 if (device_register(&mtd->dev) != 0)
436 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
439 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
440 /* No need to get a refcount on the module containing
441 the notifier, since we hold the mtd_table_mutex */
442 list_for_each_entry(not, &mtd_notifiers, list)
445 mutex_unlock(&mtd_table_mutex);
446 /* We _know_ we aren't being removed, because
447 our caller is still holding us here. So none
448 of this try_ nonsense, and no bitching about it
450 __module_get(THIS_MODULE);
454 idr_remove(&mtd_idr, i);
456 mutex_unlock(&mtd_table_mutex);
461 * del_mtd_device - unregister an MTD device
462 * @mtd: pointer to MTD device info structure
464 * Remove a device from the list of MTD devices present in the system,
465 * and notify each currently active MTD 'user' of its departure.
466 * Returns zero on success or 1 on failure, which currently will happen
467 * if the requested device does not appear to be present in the list.
470 int del_mtd_device(struct mtd_info *mtd)
473 struct mtd_notifier *not;
475 mutex_lock(&mtd_table_mutex);
477 if (idr_find(&mtd_idr, mtd->index) != mtd) {
482 /* No need to get a refcount on the module containing
483 the notifier, since we hold the mtd_table_mutex */
484 list_for_each_entry(not, &mtd_notifiers, list)
488 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
489 mtd->index, mtd->name, mtd->usecount);
492 device_unregister(&mtd->dev);
494 idr_remove(&mtd_idr, mtd->index);
496 module_put(THIS_MODULE);
501 mutex_unlock(&mtd_table_mutex);
505 static int mtd_add_device_partitions(struct mtd_info *mtd,
506 struct mtd_partition *real_parts,
511 if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
512 ret = add_mtd_device(mtd);
518 ret = add_mtd_partitions(mtd, real_parts, nbparts);
519 if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
529 * mtd_device_parse_register - parse partitions and register an MTD device.
531 * @mtd: the MTD device to register
532 * @types: the list of MTD partition probes to try, see
533 * 'parse_mtd_partitions()' for more information
534 * @parser_data: MTD partition parser-specific data
535 * @parts: fallback partition information to register, if parsing fails;
536 * only valid if %nr_parts > %0
537 * @nr_parts: the number of partitions in parts, if zero then the full
538 * MTD device is registered if no partition info is found
540 * This function aggregates MTD partitions parsing (done by
541 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
542 * basically follows the most common pattern found in many MTD drivers:
544 * * It first tries to probe partitions on MTD device @mtd using parsers
545 * specified in @types (if @types is %NULL, then the default list of parsers
546 * is used, see 'parse_mtd_partitions()' for more information). If none are
547 * found this functions tries to fallback to information specified in
549 * * If any partitioning info was found, this function registers the found
550 * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
551 * as a whole is registered first.
552 * * If no partitions were found this function just registers the MTD device
555 * Returns zero in case of success and a negative error code in case of failure.
557 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
558 struct mtd_part_parser_data *parser_data,
559 const struct mtd_partition *parts,
563 struct mtd_partition *real_parts = NULL;
565 ret = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
566 if (ret <= 0 && nr_parts && parts) {
567 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
576 ret = mtd_add_device_partitions(mtd, real_parts, ret);
579 * FIXME: some drivers unfortunately call this function more than once.
580 * So we have to check if we've already assigned the reboot notifier.
582 * Generally, we can make multiple calls work for most cases, but it
583 * does cause problems with parse_mtd_partitions() above (e.g.,
584 * cmdlineparts will register partitions more than once).
586 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
587 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
588 register_reboot_notifier(&mtd->reboot_notifier);
594 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
597 * mtd_device_unregister - unregister an existing MTD device.
599 * @master: the MTD device to unregister. This will unregister both the master
600 * and any partitions if registered.
602 int mtd_device_unregister(struct mtd_info *master)
607 unregister_reboot_notifier(&master->reboot_notifier);
609 err = del_mtd_partitions(master);
613 if (!device_is_registered(&master->dev))
616 return del_mtd_device(master);
618 EXPORT_SYMBOL_GPL(mtd_device_unregister);
621 * register_mtd_user - register a 'user' of MTD devices.
622 * @new: pointer to notifier info structure
624 * Registers a pair of callbacks function to be called upon addition
625 * or removal of MTD devices. Causes the 'add' callback to be immediately
626 * invoked for each MTD device currently present in the system.
628 void register_mtd_user (struct mtd_notifier *new)
630 struct mtd_info *mtd;
632 mutex_lock(&mtd_table_mutex);
634 list_add(&new->list, &mtd_notifiers);
636 __module_get(THIS_MODULE);
638 mtd_for_each_device(mtd)
641 mutex_unlock(&mtd_table_mutex);
643 EXPORT_SYMBOL_GPL(register_mtd_user);
646 * unregister_mtd_user - unregister a 'user' of MTD devices.
647 * @old: pointer to notifier info structure
649 * Removes a callback function pair from the list of 'users' to be
650 * notified upon addition or removal of MTD devices. Causes the
651 * 'remove' callback to be immediately invoked for each MTD device
652 * currently present in the system.
654 int unregister_mtd_user (struct mtd_notifier *old)
656 struct mtd_info *mtd;
658 mutex_lock(&mtd_table_mutex);
660 module_put(THIS_MODULE);
662 mtd_for_each_device(mtd)
665 list_del(&old->list);
666 mutex_unlock(&mtd_table_mutex);
669 EXPORT_SYMBOL_GPL(unregister_mtd_user);
672 * get_mtd_device - obtain a validated handle for an MTD device
673 * @mtd: last known address of the required MTD device
674 * @num: internal device number of the required MTD device
676 * Given a number and NULL address, return the num'th entry in the device
677 * table, if any. Given an address and num == -1, search the device table
678 * for a device with that address and return if it's still present. Given
679 * both, return the num'th driver only if its address matches. Return
682 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
684 struct mtd_info *ret = NULL, *other;
687 mutex_lock(&mtd_table_mutex);
690 mtd_for_each_device(other) {
696 } else if (num >= 0) {
697 ret = idr_find(&mtd_idr, num);
698 if (mtd && mtd != ret)
707 err = __get_mtd_device(ret);
711 mutex_unlock(&mtd_table_mutex);
714 EXPORT_SYMBOL_GPL(get_mtd_device);
717 int __get_mtd_device(struct mtd_info *mtd)
721 if (!try_module_get(mtd->owner))
724 if (mtd->_get_device) {
725 err = mtd->_get_device(mtd);
728 module_put(mtd->owner);
735 EXPORT_SYMBOL_GPL(__get_mtd_device);
738 * get_mtd_device_nm - obtain a validated handle for an MTD device by
740 * @name: MTD device name to open
742 * This function returns MTD device description structure in case of
743 * success and an error code in case of failure.
745 struct mtd_info *get_mtd_device_nm(const char *name)
748 struct mtd_info *mtd = NULL, *other;
750 mutex_lock(&mtd_table_mutex);
752 mtd_for_each_device(other) {
753 if (!strcmp(name, other->name)) {
762 err = __get_mtd_device(mtd);
766 mutex_unlock(&mtd_table_mutex);
770 mutex_unlock(&mtd_table_mutex);
773 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
775 void put_mtd_device(struct mtd_info *mtd)
777 mutex_lock(&mtd_table_mutex);
778 __put_mtd_device(mtd);
779 mutex_unlock(&mtd_table_mutex);
782 EXPORT_SYMBOL_GPL(put_mtd_device);
784 void __put_mtd_device(struct mtd_info *mtd)
787 BUG_ON(mtd->usecount < 0);
789 if (mtd->_put_device)
790 mtd->_put_device(mtd);
792 module_put(mtd->owner);
794 EXPORT_SYMBOL_GPL(__put_mtd_device);
797 * Erase is an asynchronous operation. Device drivers are supposed
798 * to call instr->callback() whenever the operation completes, even
799 * if it completes with a failure.
800 * Callers are supposed to pass a callback function and wait for it
801 * to be called before writing to the block.
803 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
805 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
807 if (!(mtd->flags & MTD_WRITEABLE))
809 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
811 instr->state = MTD_ERASE_DONE;
812 mtd_erase_callback(instr);
815 return mtd->_erase(mtd, instr);
817 EXPORT_SYMBOL_GPL(mtd_erase);
820 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
822 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
823 void **virt, resource_size_t *phys)
831 if (from < 0 || from >= mtd->size || len > mtd->size - from)
835 return mtd->_point(mtd, from, len, retlen, virt, phys);
837 EXPORT_SYMBOL_GPL(mtd_point);
839 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
840 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
844 if (from < 0 || from >= mtd->size || len > mtd->size - from)
848 return mtd->_unpoint(mtd, from, len);
850 EXPORT_SYMBOL_GPL(mtd_unpoint);
853 * Allow NOMMU mmap() to directly map the device (if not NULL)
854 * - return the address to which the offset maps
855 * - return -ENOSYS to indicate refusal to do the mapping
857 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
858 unsigned long offset, unsigned long flags)
860 if (!mtd->_get_unmapped_area)
862 if (offset >= mtd->size || len > mtd->size - offset)
864 return mtd->_get_unmapped_area(mtd, len, offset, flags);
866 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
868 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
873 if (from < 0 || from >= mtd->size || len > mtd->size - from)
879 * In the absence of an error, drivers return a non-negative integer
880 * representing the maximum number of bitflips that were corrected on
881 * any one ecc region (if applicable; zero otherwise).
883 ret_code = mtd->_read(mtd, from, len, retlen, buf);
884 if (unlikely(ret_code < 0))
886 if (mtd->ecc_strength == 0)
887 return 0; /* device lacks ecc */
888 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
890 EXPORT_SYMBOL_GPL(mtd_read);
892 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
896 if (to < 0 || to >= mtd->size || len > mtd->size - to)
898 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
902 return mtd->_write(mtd, to, len, retlen, buf);
904 EXPORT_SYMBOL_GPL(mtd_write);
907 * In blackbox flight recorder like scenarios we want to make successful writes
908 * in interrupt context. panic_write() is only intended to be called when its
909 * known the kernel is about to panic and we need the write to succeed. Since
910 * the kernel is not going to be running for much longer, this function can
911 * break locks and delay to ensure the write succeeds (but not sleep).
913 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
917 if (!mtd->_panic_write)
919 if (to < 0 || to >= mtd->size || len > mtd->size - to)
921 if (!(mtd->flags & MTD_WRITEABLE))
925 return mtd->_panic_write(mtd, to, len, retlen, buf);
927 EXPORT_SYMBOL_GPL(mtd_panic_write);
929 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
932 ops->retlen = ops->oobretlen = 0;
936 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
937 * similar to mtd->_read(), returning a non-negative integer
938 * representing max bitflips. In other cases, mtd->_read_oob() may
939 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
941 ret_code = mtd->_read_oob(mtd, from, ops);
942 if (unlikely(ret_code < 0))
944 if (mtd->ecc_strength == 0)
945 return 0; /* device lacks ecc */
946 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
948 EXPORT_SYMBOL_GPL(mtd_read_oob);
951 * Method to access the protection register area, present in some flash
952 * devices. The user data is one time programmable but the factory data is read
955 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
956 struct otp_info *buf)
958 if (!mtd->_get_fact_prot_info)
962 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
964 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
966 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
967 size_t *retlen, u_char *buf)
970 if (!mtd->_read_fact_prot_reg)
974 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
976 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
978 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
979 struct otp_info *buf)
981 if (!mtd->_get_user_prot_info)
985 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
987 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
989 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
990 size_t *retlen, u_char *buf)
993 if (!mtd->_read_user_prot_reg)
997 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
999 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1001 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1002 size_t *retlen, u_char *buf)
1007 if (!mtd->_write_user_prot_reg)
1011 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1016 * If no data could be written at all, we are out of memory and
1017 * must return -ENOSPC.
1019 return (*retlen) ? 0 : -ENOSPC;
1021 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1023 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1025 if (!mtd->_lock_user_prot_reg)
1029 return mtd->_lock_user_prot_reg(mtd, from, len);
1031 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1033 /* Chip-supported device locking */
1034 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1038 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1042 return mtd->_lock(mtd, ofs, len);
1044 EXPORT_SYMBOL_GPL(mtd_lock);
1046 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1050 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1054 return mtd->_unlock(mtd, ofs, len);
1056 EXPORT_SYMBOL_GPL(mtd_unlock);
1058 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1060 if (!mtd->_is_locked)
1062 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1066 return mtd->_is_locked(mtd, ofs, len);
1068 EXPORT_SYMBOL_GPL(mtd_is_locked);
1070 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1072 if (ofs < 0 || ofs >= mtd->size)
1074 if (!mtd->_block_isreserved)
1076 return mtd->_block_isreserved(mtd, ofs);
1078 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1080 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1082 if (ofs < 0 || ofs >= mtd->size)
1084 if (!mtd->_block_isbad)
1086 return mtd->_block_isbad(mtd, ofs);
1088 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1090 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1092 if (!mtd->_block_markbad)
1094 if (ofs < 0 || ofs >= mtd->size)
1096 if (!(mtd->flags & MTD_WRITEABLE))
1098 return mtd->_block_markbad(mtd, ofs);
1100 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1103 * default_mtd_writev - the default writev method
1104 * @mtd: mtd device description object pointer
1105 * @vecs: the vectors to write
1106 * @count: count of vectors in @vecs
1107 * @to: the MTD device offset to write to
1108 * @retlen: on exit contains the count of bytes written to the MTD device.
1110 * This function returns zero in case of success and a negative error code in
1113 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1114 unsigned long count, loff_t to, size_t *retlen)
1117 size_t totlen = 0, thislen;
1120 for (i = 0; i < count; i++) {
1121 if (!vecs[i].iov_len)
1123 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1126 if (ret || thislen != vecs[i].iov_len)
1128 to += vecs[i].iov_len;
1135 * mtd_writev - the vector-based MTD write method
1136 * @mtd: mtd device description object pointer
1137 * @vecs: the vectors to write
1138 * @count: count of vectors in @vecs
1139 * @to: the MTD device offset to write to
1140 * @retlen: on exit contains the count of bytes written to the MTD device.
1142 * This function returns zero in case of success and a negative error code in
1145 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1146 unsigned long count, loff_t to, size_t *retlen)
1149 if (!(mtd->flags & MTD_WRITEABLE))
1152 return default_mtd_writev(mtd, vecs, count, to, retlen);
1153 return mtd->_writev(mtd, vecs, count, to, retlen);
1155 EXPORT_SYMBOL_GPL(mtd_writev);
1158 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1159 * @mtd: mtd device description object pointer
1160 * @size: a pointer to the ideal or maximum size of the allocation, points
1161 * to the actual allocation size on success.
1163 * This routine attempts to allocate a contiguous kernel buffer up to
1164 * the specified size, backing off the size of the request exponentially
1165 * until the request succeeds or until the allocation size falls below
1166 * the system page size. This attempts to make sure it does not adversely
1167 * impact system performance, so when allocating more than one page, we
1168 * ask the memory allocator to avoid re-trying, swapping, writing back
1169 * or performing I/O.
1171 * Note, this function also makes sure that the allocated buffer is aligned to
1172 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1174 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1175 * to handle smaller (i.e. degraded) buffer allocations under low- or
1176 * fragmented-memory situations where such reduced allocations, from a
1177 * requested ideal, are allowed.
1179 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1181 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1183 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
1184 __GFP_NORETRY | __GFP_NO_KSWAPD;
1185 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1188 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1190 while (*size > min_alloc) {
1191 kbuf = kmalloc(*size, flags);
1196 *size = ALIGN(*size, mtd->writesize);
1200 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1201 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1203 return kmalloc(*size, GFP_KERNEL);
1205 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1207 #ifdef CONFIG_PROC_FS
1209 /*====================================================================*/
1210 /* Support for /proc/mtd */
1212 static int mtd_proc_show(struct seq_file *m, void *v)
1214 struct mtd_info *mtd;
1216 seq_puts(m, "dev: size erasesize name\n");
1217 mutex_lock(&mtd_table_mutex);
1218 mtd_for_each_device(mtd) {
1219 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1220 mtd->index, (unsigned long long)mtd->size,
1221 mtd->erasesize, mtd->name);
1223 mutex_unlock(&mtd_table_mutex);
1227 static int mtd_proc_open(struct inode *inode, struct file *file)
1229 return single_open(file, mtd_proc_show, NULL);
1232 static const struct file_operations mtd_proc_ops = {
1233 .open = mtd_proc_open,
1235 .llseek = seq_lseek,
1236 .release = single_release,
1238 #endif /* CONFIG_PROC_FS */
1240 /*====================================================================*/
1243 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1247 ret = bdi_init(bdi);
1249 ret = bdi_register(bdi, NULL, "%s", name);
1257 static struct proc_dir_entry *proc_mtd;
1259 static int __init init_mtd(void)
1263 ret = class_register(&mtd_class);
1267 ret = mtd_bdi_init(&mtd_bdi, "mtd");
1271 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1273 ret = init_mtdchar();
1281 remove_proc_entry("mtd", NULL);
1283 class_unregister(&mtd_class);
1285 pr_err("Error registering mtd class or bdi: %d\n", ret);
1289 static void __exit cleanup_mtd(void)
1293 remove_proc_entry("mtd", NULL);
1294 class_unregister(&mtd_class);
1295 bdi_destroy(&mtd_bdi);
1298 module_init(init_mtd);
1299 module_exit(cleanup_mtd);
1301 MODULE_LICENSE("GPL");
1302 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1303 MODULE_DESCRIPTION("Core MTD registration and access routines");