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 #ifdef CONFIG_PM_SLEEP
53 static int mtd_cls_suspend(struct device *dev)
55 struct mtd_info *mtd = dev_get_drvdata(dev);
57 return mtd ? mtd_suspend(mtd) : 0;
60 static int mtd_cls_resume(struct device *dev)
62 struct mtd_info *mtd = dev_get_drvdata(dev);
69 static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
70 #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
72 #define MTD_CLS_PM_OPS NULL
75 static struct class mtd_class = {
81 static DEFINE_IDR(mtd_idr);
83 /* These are exported solely for the purpose of mtd_blkdevs.c. You
84 should not use them for _anything_ else */
85 DEFINE_MUTEX(mtd_table_mutex);
86 EXPORT_SYMBOL_GPL(mtd_table_mutex);
88 struct mtd_info *__mtd_next_device(int i)
90 return idr_get_next(&mtd_idr, &i);
92 EXPORT_SYMBOL_GPL(__mtd_next_device);
94 static LIST_HEAD(mtd_notifiers);
97 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
99 /* REVISIT once MTD uses the driver model better, whoever allocates
100 * the mtd_info will probably want to use the release() hook...
102 static void mtd_release(struct device *dev)
104 struct mtd_info *mtd = dev_get_drvdata(dev);
105 dev_t index = MTD_DEVT(mtd->index);
107 /* remove /dev/mtdXro node */
108 device_destroy(&mtd_class, index + 1);
111 static ssize_t mtd_type_show(struct device *dev,
112 struct device_attribute *attr, char *buf)
114 struct mtd_info *mtd = dev_get_drvdata(dev);
139 case MTD_MLCNANDFLASH:
146 return snprintf(buf, PAGE_SIZE, "%s\n", type);
148 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
150 static ssize_t mtd_flags_show(struct device *dev,
151 struct device_attribute *attr, char *buf)
153 struct mtd_info *mtd = dev_get_drvdata(dev);
155 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
158 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
160 static ssize_t mtd_size_show(struct device *dev,
161 struct device_attribute *attr, char *buf)
163 struct mtd_info *mtd = dev_get_drvdata(dev);
165 return snprintf(buf, PAGE_SIZE, "%llu\n",
166 (unsigned long long)mtd->size);
169 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
171 static ssize_t mtd_erasesize_show(struct device *dev,
172 struct device_attribute *attr, char *buf)
174 struct mtd_info *mtd = dev_get_drvdata(dev);
176 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
179 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
181 static ssize_t mtd_writesize_show(struct device *dev,
182 struct device_attribute *attr, char *buf)
184 struct mtd_info *mtd = dev_get_drvdata(dev);
186 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
189 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
191 static ssize_t mtd_subpagesize_show(struct device *dev,
192 struct device_attribute *attr, char *buf)
194 struct mtd_info *mtd = dev_get_drvdata(dev);
195 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
197 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
200 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
202 static ssize_t mtd_oobsize_show(struct device *dev,
203 struct device_attribute *attr, char *buf)
205 struct mtd_info *mtd = dev_get_drvdata(dev);
207 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
210 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
212 static ssize_t mtd_numeraseregions_show(struct device *dev,
213 struct device_attribute *attr, char *buf)
215 struct mtd_info *mtd = dev_get_drvdata(dev);
217 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
220 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
223 static ssize_t mtd_name_show(struct device *dev,
224 struct device_attribute *attr, char *buf)
226 struct mtd_info *mtd = dev_get_drvdata(dev);
228 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
231 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
233 static ssize_t mtd_ecc_strength_show(struct device *dev,
234 struct device_attribute *attr, char *buf)
236 struct mtd_info *mtd = dev_get_drvdata(dev);
238 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
240 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
242 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
243 struct device_attribute *attr,
246 struct mtd_info *mtd = dev_get_drvdata(dev);
248 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
251 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
252 struct device_attribute *attr,
253 const char *buf, size_t count)
255 struct mtd_info *mtd = dev_get_drvdata(dev);
256 unsigned int bitflip_threshold;
259 retval = kstrtouint(buf, 0, &bitflip_threshold);
263 mtd->bitflip_threshold = bitflip_threshold;
266 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
267 mtd_bitflip_threshold_show,
268 mtd_bitflip_threshold_store);
270 static ssize_t mtd_ecc_step_size_show(struct device *dev,
271 struct device_attribute *attr, char *buf)
273 struct mtd_info *mtd = dev_get_drvdata(dev);
275 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
278 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
280 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
281 struct device_attribute *attr, char *buf)
283 struct mtd_info *mtd = dev_get_drvdata(dev);
284 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
286 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
288 static DEVICE_ATTR(corrected_bits, S_IRUGO,
289 mtd_ecc_stats_corrected_show, NULL);
291 static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
292 struct device_attribute *attr, char *buf)
294 struct mtd_info *mtd = dev_get_drvdata(dev);
295 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
297 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
299 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
301 static ssize_t mtd_badblocks_show(struct device *dev,
302 struct device_attribute *attr, char *buf)
304 struct mtd_info *mtd = dev_get_drvdata(dev);
305 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
307 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
309 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
311 static ssize_t mtd_bbtblocks_show(struct device *dev,
312 struct device_attribute *attr, char *buf)
314 struct mtd_info *mtd = dev_get_drvdata(dev);
315 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
317 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
319 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
321 static struct attribute *mtd_attrs[] = {
323 &dev_attr_flags.attr,
325 &dev_attr_erasesize.attr,
326 &dev_attr_writesize.attr,
327 &dev_attr_subpagesize.attr,
328 &dev_attr_oobsize.attr,
329 &dev_attr_numeraseregions.attr,
331 &dev_attr_ecc_strength.attr,
332 &dev_attr_ecc_step_size.attr,
333 &dev_attr_corrected_bits.attr,
334 &dev_attr_ecc_failures.attr,
335 &dev_attr_bad_blocks.attr,
336 &dev_attr_bbt_blocks.attr,
337 &dev_attr_bitflip_threshold.attr,
340 ATTRIBUTE_GROUPS(mtd);
342 static struct device_type mtd_devtype = {
344 .groups = mtd_groups,
345 .release = mtd_release,
349 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
353 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
354 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
356 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
359 return NOMMU_MAP_COPY;
362 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
365 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
368 struct mtd_info *mtd;
370 mtd = container_of(n, struct mtd_info, reboot_notifier);
377 * add_mtd_device - register an MTD device
378 * @mtd: pointer to new MTD device info structure
380 * Add a device to the list of MTD devices present in the system, and
381 * notify each currently active MTD 'user' of its arrival. Returns
382 * zero on success or non-zero on failure.
385 int add_mtd_device(struct mtd_info *mtd)
387 struct mtd_notifier *not;
390 mtd->backing_dev_info = &mtd_bdi;
392 BUG_ON(mtd->writesize == 0);
393 mutex_lock(&mtd_table_mutex);
395 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
404 /* default value if not set by driver */
405 if (mtd->bitflip_threshold == 0)
406 mtd->bitflip_threshold = mtd->ecc_strength;
408 if (is_power_of_2(mtd->erasesize))
409 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
411 mtd->erasesize_shift = 0;
413 if (is_power_of_2(mtd->writesize))
414 mtd->writesize_shift = ffs(mtd->writesize) - 1;
416 mtd->writesize_shift = 0;
418 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
419 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
421 if (mtd->dev.parent) {
422 if (!mtd->owner && mtd->dev.parent->driver)
423 mtd->owner = mtd->dev.parent->driver->owner;
425 mtd->name = dev_name(mtd->dev.parent);
427 pr_debug("mtd device won't show a device symlink in sysfs\n");
430 /* Some chips always power up locked. Unlock them now */
431 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
432 error = mtd_unlock(mtd, 0, mtd->size);
433 if (error && error != -EOPNOTSUPP)
435 "%s: unlock failed, writes may not work\n",
437 /* Ignore unlock failures? */
441 /* Caller should have set dev.parent to match the
442 * physical device, if appropriate.
444 mtd->dev.type = &mtd_devtype;
445 mtd->dev.class = &mtd_class;
446 mtd->dev.devt = MTD_DEVT(i);
447 dev_set_name(&mtd->dev, "mtd%d", i);
448 dev_set_drvdata(&mtd->dev, mtd);
449 error = device_register(&mtd->dev);
453 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
456 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
457 /* No need to get a refcount on the module containing
458 the notifier, since we hold the mtd_table_mutex */
459 list_for_each_entry(not, &mtd_notifiers, list)
462 mutex_unlock(&mtd_table_mutex);
463 /* We _know_ we aren't being removed, because
464 our caller is still holding us here. So none
465 of this try_ nonsense, and no bitching about it
467 __module_get(THIS_MODULE);
471 idr_remove(&mtd_idr, i);
473 mutex_unlock(&mtd_table_mutex);
478 * del_mtd_device - unregister an MTD device
479 * @mtd: pointer to MTD device info structure
481 * Remove a device from the list of MTD devices present in the system,
482 * and notify each currently active MTD 'user' of its departure.
483 * Returns zero on success or 1 on failure, which currently will happen
484 * if the requested device does not appear to be present in the list.
487 int del_mtd_device(struct mtd_info *mtd)
490 struct mtd_notifier *not;
492 mutex_lock(&mtd_table_mutex);
494 if (idr_find(&mtd_idr, mtd->index) != mtd) {
499 /* No need to get a refcount on the module containing
500 the notifier, since we hold the mtd_table_mutex */
501 list_for_each_entry(not, &mtd_notifiers, list)
505 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
506 mtd->index, mtd->name, mtd->usecount);
509 device_unregister(&mtd->dev);
511 idr_remove(&mtd_idr, mtd->index);
513 module_put(THIS_MODULE);
518 mutex_unlock(&mtd_table_mutex);
522 static int mtd_add_device_partitions(struct mtd_info *mtd,
523 struct mtd_partition *real_parts,
528 if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
529 ret = add_mtd_device(mtd);
535 ret = add_mtd_partitions(mtd, real_parts, nbparts);
536 if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
546 * mtd_device_parse_register - parse partitions and register an MTD device.
548 * @mtd: the MTD device to register
549 * @types: the list of MTD partition probes to try, see
550 * 'parse_mtd_partitions()' for more information
551 * @parser_data: MTD partition parser-specific data
552 * @parts: fallback partition information to register, if parsing fails;
553 * only valid if %nr_parts > %0
554 * @nr_parts: the number of partitions in parts, if zero then the full
555 * MTD device is registered if no partition info is found
557 * This function aggregates MTD partitions parsing (done by
558 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
559 * basically follows the most common pattern found in many MTD drivers:
561 * * It first tries to probe partitions on MTD device @mtd using parsers
562 * specified in @types (if @types is %NULL, then the default list of parsers
563 * is used, see 'parse_mtd_partitions()' for more information). If none are
564 * found this functions tries to fallback to information specified in
566 * * If any partitioning info was found, this function registers the found
567 * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
568 * as a whole is registered first.
569 * * If no partitions were found this function just registers the MTD device
572 * Returns zero in case of success and a negative error code in case of failure.
574 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
575 struct mtd_part_parser_data *parser_data,
576 const struct mtd_partition *parts,
580 struct mtd_partition *real_parts = NULL;
582 ret = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
583 if (ret <= 0 && nr_parts && parts) {
584 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
591 /* Didn't come up with either parsed OR fallback partitions */
593 pr_info("mtd: failed to find partitions\n");
597 ret = mtd_add_device_partitions(mtd, real_parts, ret);
602 * FIXME: some drivers unfortunately call this function more than once.
603 * So we have to check if we've already assigned the reboot notifier.
605 * Generally, we can make multiple calls work for most cases, but it
606 * does cause problems with parse_mtd_partitions() above (e.g.,
607 * cmdlineparts will register partitions more than once).
609 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
610 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
611 register_reboot_notifier(&mtd->reboot_notifier);
618 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
621 * mtd_device_unregister - unregister an existing MTD device.
623 * @master: the MTD device to unregister. This will unregister both the master
624 * and any partitions if registered.
626 int mtd_device_unregister(struct mtd_info *master)
631 unregister_reboot_notifier(&master->reboot_notifier);
633 err = del_mtd_partitions(master);
637 if (!device_is_registered(&master->dev))
640 return del_mtd_device(master);
642 EXPORT_SYMBOL_GPL(mtd_device_unregister);
645 * register_mtd_user - register a 'user' of MTD devices.
646 * @new: pointer to notifier info structure
648 * Registers a pair of callbacks function to be called upon addition
649 * or removal of MTD devices. Causes the 'add' callback to be immediately
650 * invoked for each MTD device currently present in the system.
652 void register_mtd_user (struct mtd_notifier *new)
654 struct mtd_info *mtd;
656 mutex_lock(&mtd_table_mutex);
658 list_add(&new->list, &mtd_notifiers);
660 __module_get(THIS_MODULE);
662 mtd_for_each_device(mtd)
665 mutex_unlock(&mtd_table_mutex);
667 EXPORT_SYMBOL_GPL(register_mtd_user);
670 * unregister_mtd_user - unregister a 'user' of MTD devices.
671 * @old: pointer to notifier info structure
673 * Removes a callback function pair from the list of 'users' to be
674 * notified upon addition or removal of MTD devices. Causes the
675 * 'remove' callback to be immediately invoked for each MTD device
676 * currently present in the system.
678 int unregister_mtd_user (struct mtd_notifier *old)
680 struct mtd_info *mtd;
682 mutex_lock(&mtd_table_mutex);
684 module_put(THIS_MODULE);
686 mtd_for_each_device(mtd)
689 list_del(&old->list);
690 mutex_unlock(&mtd_table_mutex);
693 EXPORT_SYMBOL_GPL(unregister_mtd_user);
696 * get_mtd_device - obtain a validated handle for an MTD device
697 * @mtd: last known address of the required MTD device
698 * @num: internal device number of the required MTD device
700 * Given a number and NULL address, return the num'th entry in the device
701 * table, if any. Given an address and num == -1, search the device table
702 * for a device with that address and return if it's still present. Given
703 * both, return the num'th driver only if its address matches. Return
706 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
708 struct mtd_info *ret = NULL, *other;
711 mutex_lock(&mtd_table_mutex);
714 mtd_for_each_device(other) {
720 } else if (num >= 0) {
721 ret = idr_find(&mtd_idr, num);
722 if (mtd && mtd != ret)
731 err = __get_mtd_device(ret);
735 mutex_unlock(&mtd_table_mutex);
738 EXPORT_SYMBOL_GPL(get_mtd_device);
741 int __get_mtd_device(struct mtd_info *mtd)
745 if (!try_module_get(mtd->owner))
748 if (mtd->_get_device) {
749 err = mtd->_get_device(mtd);
752 module_put(mtd->owner);
759 EXPORT_SYMBOL_GPL(__get_mtd_device);
762 * get_mtd_device_nm - obtain a validated handle for an MTD device by
764 * @name: MTD device name to open
766 * This function returns MTD device description structure in case of
767 * success and an error code in case of failure.
769 struct mtd_info *get_mtd_device_nm(const char *name)
772 struct mtd_info *mtd = NULL, *other;
774 mutex_lock(&mtd_table_mutex);
776 mtd_for_each_device(other) {
777 if (!strcmp(name, other->name)) {
786 err = __get_mtd_device(mtd);
790 mutex_unlock(&mtd_table_mutex);
794 mutex_unlock(&mtd_table_mutex);
797 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
799 void put_mtd_device(struct mtd_info *mtd)
801 mutex_lock(&mtd_table_mutex);
802 __put_mtd_device(mtd);
803 mutex_unlock(&mtd_table_mutex);
806 EXPORT_SYMBOL_GPL(put_mtd_device);
808 void __put_mtd_device(struct mtd_info *mtd)
811 BUG_ON(mtd->usecount < 0);
813 if (mtd->_put_device)
814 mtd->_put_device(mtd);
816 module_put(mtd->owner);
818 EXPORT_SYMBOL_GPL(__put_mtd_device);
821 * Erase is an asynchronous operation. Device drivers are supposed
822 * to call instr->callback() whenever the operation completes, even
823 * if it completes with a failure.
824 * Callers are supposed to pass a callback function and wait for it
825 * to be called before writing to the block.
827 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
829 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
831 if (!(mtd->flags & MTD_WRITEABLE))
833 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
835 instr->state = MTD_ERASE_DONE;
836 mtd_erase_callback(instr);
839 return mtd->_erase(mtd, instr);
841 EXPORT_SYMBOL_GPL(mtd_erase);
844 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
846 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
847 void **virt, resource_size_t *phys)
855 if (from < 0 || from >= mtd->size || len > mtd->size - from)
859 return mtd->_point(mtd, from, len, retlen, virt, phys);
861 EXPORT_SYMBOL_GPL(mtd_point);
863 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
864 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
868 if (from < 0 || from >= mtd->size || len > mtd->size - from)
872 return mtd->_unpoint(mtd, from, len);
874 EXPORT_SYMBOL_GPL(mtd_unpoint);
877 * Allow NOMMU mmap() to directly map the device (if not NULL)
878 * - return the address to which the offset maps
879 * - return -ENOSYS to indicate refusal to do the mapping
881 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
882 unsigned long offset, unsigned long flags)
884 if (!mtd->_get_unmapped_area)
886 if (offset >= mtd->size || len > mtd->size - offset)
888 return mtd->_get_unmapped_area(mtd, len, offset, flags);
890 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
892 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
897 if (from < 0 || from >= mtd->size || len > mtd->size - from)
903 * In the absence of an error, drivers return a non-negative integer
904 * representing the maximum number of bitflips that were corrected on
905 * any one ecc region (if applicable; zero otherwise).
907 ret_code = mtd->_read(mtd, from, len, retlen, buf);
908 if (unlikely(ret_code < 0))
910 if (mtd->ecc_strength == 0)
911 return 0; /* device lacks ecc */
912 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
914 EXPORT_SYMBOL_GPL(mtd_read);
916 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
920 if (to < 0 || to >= mtd->size || len > mtd->size - to)
922 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
926 return mtd->_write(mtd, to, len, retlen, buf);
928 EXPORT_SYMBOL_GPL(mtd_write);
931 * In blackbox flight recorder like scenarios we want to make successful writes
932 * in interrupt context. panic_write() is only intended to be called when its
933 * known the kernel is about to panic and we need the write to succeed. Since
934 * the kernel is not going to be running for much longer, this function can
935 * break locks and delay to ensure the write succeeds (but not sleep).
937 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
941 if (!mtd->_panic_write)
943 if (to < 0 || to >= mtd->size || len > mtd->size - to)
945 if (!(mtd->flags & MTD_WRITEABLE))
949 return mtd->_panic_write(mtd, to, len, retlen, buf);
951 EXPORT_SYMBOL_GPL(mtd_panic_write);
953 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
956 ops->retlen = ops->oobretlen = 0;
960 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
961 * similar to mtd->_read(), returning a non-negative integer
962 * representing max bitflips. In other cases, mtd->_read_oob() may
963 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
965 ret_code = mtd->_read_oob(mtd, from, ops);
966 if (unlikely(ret_code < 0))
968 if (mtd->ecc_strength == 0)
969 return 0; /* device lacks ecc */
970 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
972 EXPORT_SYMBOL_GPL(mtd_read_oob);
975 * Method to access the protection register area, present in some flash
976 * devices. The user data is one time programmable but the factory data is read
979 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
980 struct otp_info *buf)
982 if (!mtd->_get_fact_prot_info)
986 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
988 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
990 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
991 size_t *retlen, u_char *buf)
994 if (!mtd->_read_fact_prot_reg)
998 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1000 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1002 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1003 struct otp_info *buf)
1005 if (!mtd->_get_user_prot_info)
1009 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1011 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1013 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1014 size_t *retlen, u_char *buf)
1017 if (!mtd->_read_user_prot_reg)
1021 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1023 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1025 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1026 size_t *retlen, u_char *buf)
1031 if (!mtd->_write_user_prot_reg)
1035 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1040 * If no data could be written at all, we are out of memory and
1041 * must return -ENOSPC.
1043 return (*retlen) ? 0 : -ENOSPC;
1045 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1047 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1049 if (!mtd->_lock_user_prot_reg)
1053 return mtd->_lock_user_prot_reg(mtd, from, len);
1055 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1057 /* Chip-supported device locking */
1058 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1062 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1066 return mtd->_lock(mtd, ofs, len);
1068 EXPORT_SYMBOL_GPL(mtd_lock);
1070 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1074 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1078 return mtd->_unlock(mtd, ofs, len);
1080 EXPORT_SYMBOL_GPL(mtd_unlock);
1082 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1084 if (!mtd->_is_locked)
1086 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1090 return mtd->_is_locked(mtd, ofs, len);
1092 EXPORT_SYMBOL_GPL(mtd_is_locked);
1094 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1096 if (ofs < 0 || ofs >= mtd->size)
1098 if (!mtd->_block_isreserved)
1100 return mtd->_block_isreserved(mtd, ofs);
1102 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1104 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1106 if (ofs < 0 || ofs >= mtd->size)
1108 if (!mtd->_block_isbad)
1110 return mtd->_block_isbad(mtd, ofs);
1112 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1114 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1116 if (!mtd->_block_markbad)
1118 if (ofs < 0 || ofs >= mtd->size)
1120 if (!(mtd->flags & MTD_WRITEABLE))
1122 return mtd->_block_markbad(mtd, ofs);
1124 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1127 * default_mtd_writev - the default writev method
1128 * @mtd: mtd device description object pointer
1129 * @vecs: the vectors to write
1130 * @count: count of vectors in @vecs
1131 * @to: the MTD device offset to write to
1132 * @retlen: on exit contains the count of bytes written to the MTD device.
1134 * This function returns zero in case of success and a negative error code in
1137 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1138 unsigned long count, loff_t to, size_t *retlen)
1141 size_t totlen = 0, thislen;
1144 for (i = 0; i < count; i++) {
1145 if (!vecs[i].iov_len)
1147 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1150 if (ret || thislen != vecs[i].iov_len)
1152 to += vecs[i].iov_len;
1159 * mtd_writev - the vector-based MTD write method
1160 * @mtd: mtd device description object pointer
1161 * @vecs: the vectors to write
1162 * @count: count of vectors in @vecs
1163 * @to: the MTD device offset to write to
1164 * @retlen: on exit contains the count of bytes written to the MTD device.
1166 * This function returns zero in case of success and a negative error code in
1169 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1170 unsigned long count, loff_t to, size_t *retlen)
1173 if (!(mtd->flags & MTD_WRITEABLE))
1176 return default_mtd_writev(mtd, vecs, count, to, retlen);
1177 return mtd->_writev(mtd, vecs, count, to, retlen);
1179 EXPORT_SYMBOL_GPL(mtd_writev);
1182 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1183 * @mtd: mtd device description object pointer
1184 * @size: a pointer to the ideal or maximum size of the allocation, points
1185 * to the actual allocation size on success.
1187 * This routine attempts to allocate a contiguous kernel buffer up to
1188 * the specified size, backing off the size of the request exponentially
1189 * until the request succeeds or until the allocation size falls below
1190 * the system page size. This attempts to make sure it does not adversely
1191 * impact system performance, so when allocating more than one page, we
1192 * ask the memory allocator to avoid re-trying, swapping, writing back
1193 * or performing I/O.
1195 * Note, this function also makes sure that the allocated buffer is aligned to
1196 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1198 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1199 * to handle smaller (i.e. degraded) buffer allocations under low- or
1200 * fragmented-memory situations where such reduced allocations, from a
1201 * requested ideal, are allowed.
1203 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1205 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1207 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
1208 __GFP_NORETRY | __GFP_NO_KSWAPD;
1209 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1212 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1214 while (*size > min_alloc) {
1215 kbuf = kmalloc(*size, flags);
1220 *size = ALIGN(*size, mtd->writesize);
1224 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1225 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1227 return kmalloc(*size, GFP_KERNEL);
1229 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1231 #ifdef CONFIG_PROC_FS
1233 /*====================================================================*/
1234 /* Support for /proc/mtd */
1236 static int mtd_proc_show(struct seq_file *m, void *v)
1238 struct mtd_info *mtd;
1240 seq_puts(m, "dev: size erasesize name\n");
1241 mutex_lock(&mtd_table_mutex);
1242 mtd_for_each_device(mtd) {
1243 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1244 mtd->index, (unsigned long long)mtd->size,
1245 mtd->erasesize, mtd->name);
1247 mutex_unlock(&mtd_table_mutex);
1251 static int mtd_proc_open(struct inode *inode, struct file *file)
1253 return single_open(file, mtd_proc_show, NULL);
1256 static const struct file_operations mtd_proc_ops = {
1257 .open = mtd_proc_open,
1259 .llseek = seq_lseek,
1260 .release = single_release,
1262 #endif /* CONFIG_PROC_FS */
1264 /*====================================================================*/
1267 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1271 ret = bdi_init(bdi);
1273 ret = bdi_register(bdi, NULL, "%s", name);
1281 static struct proc_dir_entry *proc_mtd;
1283 static int __init init_mtd(void)
1287 ret = class_register(&mtd_class);
1291 ret = mtd_bdi_init(&mtd_bdi, "mtd");
1295 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1297 ret = init_mtdchar();
1305 remove_proc_entry("mtd", NULL);
1307 class_unregister(&mtd_class);
1309 pr_err("Error registering mtd class or bdi: %d\n", ret);
1313 static void __exit cleanup_mtd(void)
1317 remove_proc_entry("mtd", NULL);
1318 class_unregister(&mtd_class);
1319 bdi_destroy(&mtd_bdi);
1320 idr_destroy(&mtd_idr);
1323 module_init(init_mtd);
1324 module_exit(cleanup_mtd);
1326 MODULE_LICENSE("GPL");
1327 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1328 MODULE_DESCRIPTION("Core MTD registration and access routines");