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;
391 * May occur, for instance, on buggy drivers which call
392 * mtd_device_parse_register() multiple times on the same master MTD,
393 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
395 if (WARN_ONCE(mtd->backing_dev_info, "MTD already registered\n"))
398 mtd->backing_dev_info = &mtd_bdi;
400 BUG_ON(mtd->writesize == 0);
401 mutex_lock(&mtd_table_mutex);
403 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
412 /* default value if not set by driver */
413 if (mtd->bitflip_threshold == 0)
414 mtd->bitflip_threshold = mtd->ecc_strength;
416 if (is_power_of_2(mtd->erasesize))
417 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
419 mtd->erasesize_shift = 0;
421 if (is_power_of_2(mtd->writesize))
422 mtd->writesize_shift = ffs(mtd->writesize) - 1;
424 mtd->writesize_shift = 0;
426 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
427 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
429 if (mtd->dev.parent) {
430 if (!mtd->owner && mtd->dev.parent->driver)
431 mtd->owner = mtd->dev.parent->driver->owner;
433 mtd->name = dev_name(mtd->dev.parent);
435 pr_debug("mtd device won't show a device symlink in sysfs\n");
438 /* Some chips always power up locked. Unlock them now */
439 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
440 error = mtd_unlock(mtd, 0, mtd->size);
441 if (error && error != -EOPNOTSUPP)
443 "%s: unlock failed, writes may not work\n",
445 /* Ignore unlock failures? */
449 /* Caller should have set dev.parent to match the
450 * physical device, if appropriate.
452 mtd->dev.type = &mtd_devtype;
453 mtd->dev.class = &mtd_class;
454 mtd->dev.devt = MTD_DEVT(i);
455 dev_set_name(&mtd->dev, "mtd%d", i);
456 dev_set_drvdata(&mtd->dev, mtd);
457 error = device_register(&mtd->dev);
461 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
464 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
465 /* No need to get a refcount on the module containing
466 the notifier, since we hold the mtd_table_mutex */
467 list_for_each_entry(not, &mtd_notifiers, list)
470 mutex_unlock(&mtd_table_mutex);
471 /* We _know_ we aren't being removed, because
472 our caller is still holding us here. So none
473 of this try_ nonsense, and no bitching about it
475 __module_get(THIS_MODULE);
479 idr_remove(&mtd_idr, i);
481 mutex_unlock(&mtd_table_mutex);
486 * del_mtd_device - unregister an MTD device
487 * @mtd: pointer to MTD device info structure
489 * Remove a device from the list of MTD devices present in the system,
490 * and notify each currently active MTD 'user' of its departure.
491 * Returns zero on success or 1 on failure, which currently will happen
492 * if the requested device does not appear to be present in the list.
495 int del_mtd_device(struct mtd_info *mtd)
498 struct mtd_notifier *not;
500 mutex_lock(&mtd_table_mutex);
502 if (idr_find(&mtd_idr, mtd->index) != mtd) {
507 /* No need to get a refcount on the module containing
508 the notifier, since we hold the mtd_table_mutex */
509 list_for_each_entry(not, &mtd_notifiers, list)
513 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
514 mtd->index, mtd->name, mtd->usecount);
517 device_unregister(&mtd->dev);
519 idr_remove(&mtd_idr, mtd->index);
521 module_put(THIS_MODULE);
526 mutex_unlock(&mtd_table_mutex);
530 static int mtd_add_device_partitions(struct mtd_info *mtd,
531 struct mtd_partition *real_parts,
536 if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
537 ret = add_mtd_device(mtd);
543 ret = add_mtd_partitions(mtd, real_parts, nbparts);
544 if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
554 * mtd_device_parse_register - parse partitions and register an MTD device.
556 * @mtd: the MTD device to register
557 * @types: the list of MTD partition probes to try, see
558 * 'parse_mtd_partitions()' for more information
559 * @parser_data: MTD partition parser-specific data
560 * @parts: fallback partition information to register, if parsing fails;
561 * only valid if %nr_parts > %0
562 * @nr_parts: the number of partitions in parts, if zero then the full
563 * MTD device is registered if no partition info is found
565 * This function aggregates MTD partitions parsing (done by
566 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
567 * basically follows the most common pattern found in many MTD drivers:
569 * * It first tries to probe partitions on MTD device @mtd using parsers
570 * specified in @types (if @types is %NULL, then the default list of parsers
571 * is used, see 'parse_mtd_partitions()' for more information). If none are
572 * found this functions tries to fallback to information specified in
574 * * If any partitioning info was found, this function registers the found
575 * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
576 * as a whole is registered first.
577 * * If no partitions were found this function just registers the MTD device
580 * Returns zero in case of success and a negative error code in case of failure.
582 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
583 struct mtd_part_parser_data *parser_data,
584 const struct mtd_partition *parts,
588 struct mtd_partition *real_parts = NULL;
590 ret = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
591 if (ret <= 0 && nr_parts && parts) {
592 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
599 /* Didn't come up with either parsed OR fallback partitions */
601 pr_info("mtd: failed to find partitions; one or more parsers reports errors (%d)\n",
603 /* Don't abort on errors; we can still use unpartitioned MTD */
607 ret = mtd_add_device_partitions(mtd, real_parts, ret);
612 * FIXME: some drivers unfortunately call this function more than once.
613 * So we have to check if we've already assigned the reboot notifier.
615 * Generally, we can make multiple calls work for most cases, but it
616 * does cause problems with parse_mtd_partitions() above (e.g.,
617 * cmdlineparts will register partitions more than once).
619 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
620 "MTD already registered\n");
621 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
622 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
623 register_reboot_notifier(&mtd->reboot_notifier);
630 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
633 * mtd_device_unregister - unregister an existing MTD device.
635 * @master: the MTD device to unregister. This will unregister both the master
636 * and any partitions if registered.
638 int mtd_device_unregister(struct mtd_info *master)
643 unregister_reboot_notifier(&master->reboot_notifier);
645 err = del_mtd_partitions(master);
649 if (!device_is_registered(&master->dev))
652 return del_mtd_device(master);
654 EXPORT_SYMBOL_GPL(mtd_device_unregister);
657 * register_mtd_user - register a 'user' of MTD devices.
658 * @new: pointer to notifier info structure
660 * Registers a pair of callbacks function to be called upon addition
661 * or removal of MTD devices. Causes the 'add' callback to be immediately
662 * invoked for each MTD device currently present in the system.
664 void register_mtd_user (struct mtd_notifier *new)
666 struct mtd_info *mtd;
668 mutex_lock(&mtd_table_mutex);
670 list_add(&new->list, &mtd_notifiers);
672 __module_get(THIS_MODULE);
674 mtd_for_each_device(mtd)
677 mutex_unlock(&mtd_table_mutex);
679 EXPORT_SYMBOL_GPL(register_mtd_user);
682 * unregister_mtd_user - unregister a 'user' of MTD devices.
683 * @old: pointer to notifier info structure
685 * Removes a callback function pair from the list of 'users' to be
686 * notified upon addition or removal of MTD devices. Causes the
687 * 'remove' callback to be immediately invoked for each MTD device
688 * currently present in the system.
690 int unregister_mtd_user (struct mtd_notifier *old)
692 struct mtd_info *mtd;
694 mutex_lock(&mtd_table_mutex);
696 module_put(THIS_MODULE);
698 mtd_for_each_device(mtd)
701 list_del(&old->list);
702 mutex_unlock(&mtd_table_mutex);
705 EXPORT_SYMBOL_GPL(unregister_mtd_user);
708 * get_mtd_device - obtain a validated handle for an MTD device
709 * @mtd: last known address of the required MTD device
710 * @num: internal device number of the required MTD device
712 * Given a number and NULL address, return the num'th entry in the device
713 * table, if any. Given an address and num == -1, search the device table
714 * for a device with that address and return if it's still present. Given
715 * both, return the num'th driver only if its address matches. Return
718 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
720 struct mtd_info *ret = NULL, *other;
723 mutex_lock(&mtd_table_mutex);
726 mtd_for_each_device(other) {
732 } else if (num >= 0) {
733 ret = idr_find(&mtd_idr, num);
734 if (mtd && mtd != ret)
743 err = __get_mtd_device(ret);
747 mutex_unlock(&mtd_table_mutex);
750 EXPORT_SYMBOL_GPL(get_mtd_device);
753 int __get_mtd_device(struct mtd_info *mtd)
757 if (!try_module_get(mtd->owner))
760 if (mtd->_get_device) {
761 err = mtd->_get_device(mtd);
764 module_put(mtd->owner);
771 EXPORT_SYMBOL_GPL(__get_mtd_device);
774 * get_mtd_device_nm - obtain a validated handle for an MTD device by
776 * @name: MTD device name to open
778 * This function returns MTD device description structure in case of
779 * success and an error code in case of failure.
781 struct mtd_info *get_mtd_device_nm(const char *name)
784 struct mtd_info *mtd = NULL, *other;
786 mutex_lock(&mtd_table_mutex);
788 mtd_for_each_device(other) {
789 if (!strcmp(name, other->name)) {
798 err = __get_mtd_device(mtd);
802 mutex_unlock(&mtd_table_mutex);
806 mutex_unlock(&mtd_table_mutex);
809 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
811 void put_mtd_device(struct mtd_info *mtd)
813 mutex_lock(&mtd_table_mutex);
814 __put_mtd_device(mtd);
815 mutex_unlock(&mtd_table_mutex);
818 EXPORT_SYMBOL_GPL(put_mtd_device);
820 void __put_mtd_device(struct mtd_info *mtd)
823 BUG_ON(mtd->usecount < 0);
825 if (mtd->_put_device)
826 mtd->_put_device(mtd);
828 module_put(mtd->owner);
830 EXPORT_SYMBOL_GPL(__put_mtd_device);
833 * Erase is an asynchronous operation. Device drivers are supposed
834 * to call instr->callback() whenever the operation completes, even
835 * if it completes with a failure.
836 * Callers are supposed to pass a callback function and wait for it
837 * to be called before writing to the block.
839 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
841 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
843 if (!(mtd->flags & MTD_WRITEABLE))
845 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
847 instr->state = MTD_ERASE_DONE;
848 mtd_erase_callback(instr);
851 return mtd->_erase(mtd, instr);
853 EXPORT_SYMBOL_GPL(mtd_erase);
856 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
858 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
859 void **virt, resource_size_t *phys)
867 if (from < 0 || from >= mtd->size || len > mtd->size - from)
871 return mtd->_point(mtd, from, len, retlen, virt, phys);
873 EXPORT_SYMBOL_GPL(mtd_point);
875 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
876 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
880 if (from < 0 || from >= mtd->size || len > mtd->size - from)
884 return mtd->_unpoint(mtd, from, len);
886 EXPORT_SYMBOL_GPL(mtd_unpoint);
889 * Allow NOMMU mmap() to directly map the device (if not NULL)
890 * - return the address to which the offset maps
891 * - return -ENOSYS to indicate refusal to do the mapping
893 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
894 unsigned long offset, unsigned long flags)
896 if (!mtd->_get_unmapped_area)
898 if (offset >= mtd->size || len > mtd->size - offset)
900 return mtd->_get_unmapped_area(mtd, len, offset, flags);
902 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
904 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
909 if (from < 0 || from >= mtd->size || len > mtd->size - from)
915 * In the absence of an error, drivers return a non-negative integer
916 * representing the maximum number of bitflips that were corrected on
917 * any one ecc region (if applicable; zero otherwise).
919 ret_code = mtd->_read(mtd, from, len, retlen, buf);
920 if (unlikely(ret_code < 0))
922 if (mtd->ecc_strength == 0)
923 return 0; /* device lacks ecc */
924 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
926 EXPORT_SYMBOL_GPL(mtd_read);
928 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
932 if (to < 0 || to >= mtd->size || len > mtd->size - to)
934 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
938 return mtd->_write(mtd, to, len, retlen, buf);
940 EXPORT_SYMBOL_GPL(mtd_write);
943 * In blackbox flight recorder like scenarios we want to make successful writes
944 * in interrupt context. panic_write() is only intended to be called when its
945 * known the kernel is about to panic and we need the write to succeed. Since
946 * the kernel is not going to be running for much longer, this function can
947 * break locks and delay to ensure the write succeeds (but not sleep).
949 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
953 if (!mtd->_panic_write)
955 if (to < 0 || to >= mtd->size || len > mtd->size - to)
957 if (!(mtd->flags & MTD_WRITEABLE))
961 return mtd->_panic_write(mtd, to, len, retlen, buf);
963 EXPORT_SYMBOL_GPL(mtd_panic_write);
965 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
968 ops->retlen = ops->oobretlen = 0;
972 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
973 * similar to mtd->_read(), returning a non-negative integer
974 * representing max bitflips. In other cases, mtd->_read_oob() may
975 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
977 ret_code = mtd->_read_oob(mtd, from, ops);
978 if (unlikely(ret_code < 0))
980 if (mtd->ecc_strength == 0)
981 return 0; /* device lacks ecc */
982 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
984 EXPORT_SYMBOL_GPL(mtd_read_oob);
987 * Method to access the protection register area, present in some flash
988 * devices. The user data is one time programmable but the factory data is read
991 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
992 struct otp_info *buf)
994 if (!mtd->_get_fact_prot_info)
998 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1000 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1002 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1003 size_t *retlen, u_char *buf)
1006 if (!mtd->_read_fact_prot_reg)
1010 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1012 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1014 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1015 struct otp_info *buf)
1017 if (!mtd->_get_user_prot_info)
1021 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1023 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1025 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1026 size_t *retlen, u_char *buf)
1029 if (!mtd->_read_user_prot_reg)
1033 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1035 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1037 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1038 size_t *retlen, u_char *buf)
1043 if (!mtd->_write_user_prot_reg)
1047 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1052 * If no data could be written at all, we are out of memory and
1053 * must return -ENOSPC.
1055 return (*retlen) ? 0 : -ENOSPC;
1057 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1059 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1061 if (!mtd->_lock_user_prot_reg)
1065 return mtd->_lock_user_prot_reg(mtd, from, len);
1067 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1069 /* Chip-supported device locking */
1070 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1074 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1078 return mtd->_lock(mtd, ofs, len);
1080 EXPORT_SYMBOL_GPL(mtd_lock);
1082 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1086 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1090 return mtd->_unlock(mtd, ofs, len);
1092 EXPORT_SYMBOL_GPL(mtd_unlock);
1094 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1096 if (!mtd->_is_locked)
1098 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1102 return mtd->_is_locked(mtd, ofs, len);
1104 EXPORT_SYMBOL_GPL(mtd_is_locked);
1106 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1108 if (ofs < 0 || ofs >= mtd->size)
1110 if (!mtd->_block_isreserved)
1112 return mtd->_block_isreserved(mtd, ofs);
1114 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1116 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1118 if (ofs < 0 || ofs >= mtd->size)
1120 if (!mtd->_block_isbad)
1122 return mtd->_block_isbad(mtd, ofs);
1124 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1126 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1128 if (!mtd->_block_markbad)
1130 if (ofs < 0 || ofs >= mtd->size)
1132 if (!(mtd->flags & MTD_WRITEABLE))
1134 return mtd->_block_markbad(mtd, ofs);
1136 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1139 * default_mtd_writev - the default writev method
1140 * @mtd: mtd device description object pointer
1141 * @vecs: the vectors to write
1142 * @count: count of vectors in @vecs
1143 * @to: the MTD device offset to write to
1144 * @retlen: on exit contains the count of bytes written to the MTD device.
1146 * This function returns zero in case of success and a negative error code in
1149 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1150 unsigned long count, loff_t to, size_t *retlen)
1153 size_t totlen = 0, thislen;
1156 for (i = 0; i < count; i++) {
1157 if (!vecs[i].iov_len)
1159 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1162 if (ret || thislen != vecs[i].iov_len)
1164 to += vecs[i].iov_len;
1171 * mtd_writev - the vector-based MTD write method
1172 * @mtd: mtd device description object pointer
1173 * @vecs: the vectors to write
1174 * @count: count of vectors in @vecs
1175 * @to: the MTD device offset to write to
1176 * @retlen: on exit contains the count of bytes written to the MTD device.
1178 * This function returns zero in case of success and a negative error code in
1181 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1182 unsigned long count, loff_t to, size_t *retlen)
1185 if (!(mtd->flags & MTD_WRITEABLE))
1188 return default_mtd_writev(mtd, vecs, count, to, retlen);
1189 return mtd->_writev(mtd, vecs, count, to, retlen);
1191 EXPORT_SYMBOL_GPL(mtd_writev);
1194 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1195 * @mtd: mtd device description object pointer
1196 * @size: a pointer to the ideal or maximum size of the allocation, points
1197 * to the actual allocation size on success.
1199 * This routine attempts to allocate a contiguous kernel buffer up to
1200 * the specified size, backing off the size of the request exponentially
1201 * until the request succeeds or until the allocation size falls below
1202 * the system page size. This attempts to make sure it does not adversely
1203 * impact system performance, so when allocating more than one page, we
1204 * ask the memory allocator to avoid re-trying, swapping, writing back
1205 * or performing I/O.
1207 * Note, this function also makes sure that the allocated buffer is aligned to
1208 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1210 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1211 * to handle smaller (i.e. degraded) buffer allocations under low- or
1212 * fragmented-memory situations where such reduced allocations, from a
1213 * requested ideal, are allowed.
1215 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1217 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1219 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1220 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1223 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1225 while (*size > min_alloc) {
1226 kbuf = kmalloc(*size, flags);
1231 *size = ALIGN(*size, mtd->writesize);
1235 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1236 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1238 return kmalloc(*size, GFP_KERNEL);
1240 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1242 #ifdef CONFIG_PROC_FS
1244 /*====================================================================*/
1245 /* Support for /proc/mtd */
1247 static int mtd_proc_show(struct seq_file *m, void *v)
1249 struct mtd_info *mtd;
1251 seq_puts(m, "dev: size erasesize name\n");
1252 mutex_lock(&mtd_table_mutex);
1253 mtd_for_each_device(mtd) {
1254 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1255 mtd->index, (unsigned long long)mtd->size,
1256 mtd->erasesize, mtd->name);
1258 mutex_unlock(&mtd_table_mutex);
1262 static int mtd_proc_open(struct inode *inode, struct file *file)
1264 return single_open(file, mtd_proc_show, NULL);
1267 static const struct file_operations mtd_proc_ops = {
1268 .open = mtd_proc_open,
1270 .llseek = seq_lseek,
1271 .release = single_release,
1273 #endif /* CONFIG_PROC_FS */
1275 /*====================================================================*/
1278 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1282 ret = bdi_init(bdi);
1284 ret = bdi_register(bdi, NULL, "%s", name);
1292 static struct proc_dir_entry *proc_mtd;
1294 static int __init init_mtd(void)
1298 ret = class_register(&mtd_class);
1302 ret = mtd_bdi_init(&mtd_bdi, "mtd");
1306 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1308 ret = init_mtdchar();
1316 remove_proc_entry("mtd", NULL);
1318 class_unregister(&mtd_class);
1320 pr_err("Error registering mtd class or bdi: %d\n", ret);
1324 static void __exit cleanup_mtd(void)
1328 remove_proc_entry("mtd", NULL);
1329 class_unregister(&mtd_class);
1330 bdi_destroy(&mtd_bdi);
1331 idr_destroy(&mtd_idr);
1334 module_init(init_mtd);
1335 module_exit(cleanup_mtd);
1337 MODULE_LICENSE("GPL");
1338 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1339 MODULE_DESCRIPTION("Core MTD registration and access routines");