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>
42 #include <linux/mtd/mtd.h>
43 #include <linux/mtd/partitions.h>
48 * backing device capabilities for non-mappable devices (such as NAND flash)
49 * - permits private mappings, copies are taken of the data
51 static struct backing_dev_info mtd_bdi_unmappable = {
52 .capabilities = BDI_CAP_MAP_COPY,
56 * backing device capabilities for R/O mappable devices (such as ROM)
57 * - permits private mappings, copies are taken of the data
58 * - permits non-writable shared mappings
60 static struct backing_dev_info mtd_bdi_ro_mappable = {
61 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
62 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
66 * backing device capabilities for writable mappable devices (such as RAM)
67 * - permits private mappings, copies are taken of the data
68 * - permits non-writable shared mappings
70 static struct backing_dev_info mtd_bdi_rw_mappable = {
71 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
72 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
76 static int mtd_cls_suspend(struct device *dev, pm_message_t state);
77 static int mtd_cls_resume(struct device *dev);
79 static struct class mtd_class = {
82 .suspend = mtd_cls_suspend,
83 .resume = mtd_cls_resume,
86 static DEFINE_IDR(mtd_idr);
88 /* These are exported solely for the purpose of mtd_blkdevs.c. You
89 should not use them for _anything_ else */
90 DEFINE_MUTEX(mtd_table_mutex);
91 EXPORT_SYMBOL_GPL(mtd_table_mutex);
93 struct mtd_info *__mtd_next_device(int i)
95 return idr_get_next(&mtd_idr, &i);
97 EXPORT_SYMBOL_GPL(__mtd_next_device);
99 static LIST_HEAD(mtd_notifiers);
102 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
104 /* REVISIT once MTD uses the driver model better, whoever allocates
105 * the mtd_info will probably want to use the release() hook...
107 static void mtd_release(struct device *dev)
109 struct mtd_info *mtd = dev_get_drvdata(dev);
110 dev_t index = MTD_DEVT(mtd->index);
112 /* remove /dev/mtdXro node */
113 device_destroy(&mtd_class, index + 1);
116 static int mtd_cls_suspend(struct device *dev, pm_message_t state)
118 struct mtd_info *mtd = dev_get_drvdata(dev);
120 return mtd ? mtd_suspend(mtd) : 0;
123 static int mtd_cls_resume(struct device *dev)
125 struct mtd_info *mtd = dev_get_drvdata(dev);
132 static ssize_t mtd_type_show(struct device *dev,
133 struct device_attribute *attr, char *buf)
135 struct mtd_info *mtd = dev_get_drvdata(dev);
160 case MTD_MLCNANDFLASH:
167 return snprintf(buf, PAGE_SIZE, "%s\n", type);
169 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
171 static ssize_t mtd_flags_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, "0x%lx\n", (unsigned long)mtd->flags);
179 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
181 static ssize_t mtd_size_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, "%llu\n",
187 (unsigned long long)mtd->size);
190 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
192 static ssize_t mtd_erasesize_show(struct device *dev,
193 struct device_attribute *attr, char *buf)
195 struct mtd_info *mtd = dev_get_drvdata(dev);
197 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
200 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
202 static ssize_t mtd_writesize_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->writesize);
210 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
212 static ssize_t mtd_subpagesize_show(struct device *dev,
213 struct device_attribute *attr, char *buf)
215 struct mtd_info *mtd = dev_get_drvdata(dev);
216 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
218 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
221 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
223 static ssize_t mtd_oobsize_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, "%lu\n", (unsigned long)mtd->oobsize);
231 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
233 static ssize_t mtd_numeraseregions_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->numeraseregions);
241 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
244 static ssize_t mtd_name_show(struct device *dev,
245 struct device_attribute *attr, char *buf)
247 struct mtd_info *mtd = dev_get_drvdata(dev);
249 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
252 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
254 static ssize_t mtd_ecc_strength_show(struct device *dev,
255 struct device_attribute *attr, char *buf)
257 struct mtd_info *mtd = dev_get_drvdata(dev);
259 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
261 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
263 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
264 struct device_attribute *attr,
267 struct mtd_info *mtd = dev_get_drvdata(dev);
269 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
272 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
273 struct device_attribute *attr,
274 const char *buf, size_t count)
276 struct mtd_info *mtd = dev_get_drvdata(dev);
277 unsigned int bitflip_threshold;
280 retval = kstrtouint(buf, 0, &bitflip_threshold);
284 mtd->bitflip_threshold = bitflip_threshold;
287 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
288 mtd_bitflip_threshold_show,
289 mtd_bitflip_threshold_store);
291 static ssize_t mtd_ecc_step_size_show(struct device *dev,
292 struct device_attribute *attr, char *buf)
294 struct mtd_info *mtd = dev_get_drvdata(dev);
296 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
299 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
301 static ssize_t mtd_ecc_stats_corrected_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->corrected);
309 static DEVICE_ATTR(corrected_bits, S_IRUGO,
310 mtd_ecc_stats_corrected_show, NULL);
312 static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
313 struct device_attribute *attr, char *buf)
315 struct mtd_info *mtd = dev_get_drvdata(dev);
316 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
318 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
320 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
322 static ssize_t mtd_badblocks_show(struct device *dev,
323 struct device_attribute *attr, char *buf)
325 struct mtd_info *mtd = dev_get_drvdata(dev);
326 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
328 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
330 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
332 static ssize_t mtd_bbtblocks_show(struct device *dev,
333 struct device_attribute *attr, char *buf)
335 struct mtd_info *mtd = dev_get_drvdata(dev);
336 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
338 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
340 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
342 static struct attribute *mtd_attrs[] = {
344 &dev_attr_flags.attr,
346 &dev_attr_erasesize.attr,
347 &dev_attr_writesize.attr,
348 &dev_attr_subpagesize.attr,
349 &dev_attr_oobsize.attr,
350 &dev_attr_numeraseregions.attr,
352 &dev_attr_ecc_strength.attr,
353 &dev_attr_ecc_step_size.attr,
354 &dev_attr_corrected_bits.attr,
355 &dev_attr_ecc_failures.attr,
356 &dev_attr_bad_blocks.attr,
357 &dev_attr_bbt_blocks.attr,
358 &dev_attr_bitflip_threshold.attr,
361 ATTRIBUTE_GROUPS(mtd);
363 static struct device_type mtd_devtype = {
365 .groups = mtd_groups,
366 .release = mtd_release,
369 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
372 struct mtd_info *mtd;
374 mtd = container_of(n, struct mtd_info, reboot_notifier);
381 * add_mtd_device - register an MTD device
382 * @mtd: pointer to new MTD device info structure
384 * Add a device to the list of MTD devices present in the system, and
385 * notify each currently active MTD 'user' of its arrival. Returns
386 * zero on success or 1 on failure, which currently will only happen
387 * if there is insufficient memory or a sysfs error.
390 int add_mtd_device(struct mtd_info *mtd)
392 struct mtd_notifier *not;
395 if (!mtd->backing_dev_info) {
398 mtd->backing_dev_info = &mtd_bdi_rw_mappable;
401 mtd->backing_dev_info = &mtd_bdi_ro_mappable;
404 mtd->backing_dev_info = &mtd_bdi_unmappable;
409 BUG_ON(mtd->writesize == 0);
410 mutex_lock(&mtd_table_mutex);
412 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
419 /* default value if not set by driver */
420 if (mtd->bitflip_threshold == 0)
421 mtd->bitflip_threshold = mtd->ecc_strength;
423 if (is_power_of_2(mtd->erasesize))
424 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
426 mtd->erasesize_shift = 0;
428 if (is_power_of_2(mtd->writesize))
429 mtd->writesize_shift = ffs(mtd->writesize) - 1;
431 mtd->writesize_shift = 0;
433 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
434 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
436 /* Some chips always power up locked. Unlock them now */
437 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
438 error = mtd_unlock(mtd, 0, mtd->size);
439 if (error && error != -EOPNOTSUPP)
441 "%s: unlock failed, writes may not work\n",
445 /* Caller should have set dev.parent to match the
448 mtd->dev.type = &mtd_devtype;
449 mtd->dev.class = &mtd_class;
450 mtd->dev.devt = MTD_DEVT(i);
451 dev_set_name(&mtd->dev, "mtd%d", i);
452 dev_set_drvdata(&mtd->dev, mtd);
453 if (device_register(&mtd->dev) != 0)
456 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
459 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
460 /* No need to get a refcount on the module containing
461 the notifier, since we hold the mtd_table_mutex */
462 list_for_each_entry(not, &mtd_notifiers, list)
465 mutex_unlock(&mtd_table_mutex);
466 /* We _know_ we aren't being removed, because
467 our caller is still holding us here. So none
468 of this try_ nonsense, and no bitching about it
470 __module_get(THIS_MODULE);
474 idr_remove(&mtd_idr, i);
476 mutex_unlock(&mtd_table_mutex);
481 * del_mtd_device - unregister an MTD device
482 * @mtd: pointer to MTD device info structure
484 * Remove a device from the list of MTD devices present in the system,
485 * and notify each currently active MTD 'user' of its departure.
486 * Returns zero on success or 1 on failure, which currently will happen
487 * if the requested device does not appear to be present in the list.
490 int del_mtd_device(struct mtd_info *mtd)
493 struct mtd_notifier *not;
495 mutex_lock(&mtd_table_mutex);
497 if (idr_find(&mtd_idr, mtd->index) != mtd) {
502 /* No need to get a refcount on the module containing
503 the notifier, since we hold the mtd_table_mutex */
504 list_for_each_entry(not, &mtd_notifiers, list)
508 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
509 mtd->index, mtd->name, mtd->usecount);
512 device_unregister(&mtd->dev);
514 idr_remove(&mtd_idr, mtd->index);
516 module_put(THIS_MODULE);
521 mutex_unlock(&mtd_table_mutex);
526 * mtd_device_parse_register - parse partitions and register an MTD device.
528 * @mtd: the MTD device to register
529 * @types: the list of MTD partition probes to try, see
530 * 'parse_mtd_partitions()' for more information
531 * @parser_data: MTD partition parser-specific data
532 * @parts: fallback partition information to register, if parsing fails;
533 * only valid if %nr_parts > %0
534 * @nr_parts: the number of partitions in parts, if zero then the full
535 * MTD device is registered if no partition info is found
537 * This function aggregates MTD partitions parsing (done by
538 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
539 * basically follows the most common pattern found in many MTD drivers:
541 * * It first tries to probe partitions on MTD device @mtd using parsers
542 * specified in @types (if @types is %NULL, then the default list of parsers
543 * is used, see 'parse_mtd_partitions()' for more information). If none are
544 * found this functions tries to fallback to information specified in
546 * * If any partitioning info was found, this function registers the found
548 * * If no partitions were found this function just registers the MTD device
551 * Returns zero in case of success and a negative error code in case of failure.
553 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
554 struct mtd_part_parser_data *parser_data,
555 const struct mtd_partition *parts,
559 struct mtd_partition *real_parts;
561 err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
562 if (err <= 0 && nr_parts && parts) {
563 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
572 err = add_mtd_partitions(mtd, real_parts, err);
574 } else if (err == 0) {
575 err = add_mtd_device(mtd);
581 * FIXME: some drivers unfortunately call this function more than once.
582 * So we have to check if we've already assigned the reboot notifier.
584 * Generally, we can make multiple calls work for most cases, but it
585 * does cause problems with parse_mtd_partitions() above (e.g.,
586 * cmdlineparts will register partitions more than once).
588 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
589 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
590 register_reboot_notifier(&mtd->reboot_notifier);
595 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
598 * mtd_device_unregister - unregister an existing MTD device.
600 * @master: the MTD device to unregister. This will unregister both the master
601 * and any partitions if registered.
603 int mtd_device_unregister(struct mtd_info *master)
608 unregister_reboot_notifier(&master->reboot_notifier);
610 err = del_mtd_partitions(master);
614 if (!device_is_registered(&master->dev))
617 return del_mtd_device(master);
619 EXPORT_SYMBOL_GPL(mtd_device_unregister);
622 * register_mtd_user - register a 'user' of MTD devices.
623 * @new: pointer to notifier info structure
625 * Registers a pair of callbacks function to be called upon addition
626 * or removal of MTD devices. Causes the 'add' callback to be immediately
627 * invoked for each MTD device currently present in the system.
629 void register_mtd_user (struct mtd_notifier *new)
631 struct mtd_info *mtd;
633 mutex_lock(&mtd_table_mutex);
635 list_add(&new->list, &mtd_notifiers);
637 __module_get(THIS_MODULE);
639 mtd_for_each_device(mtd)
642 mutex_unlock(&mtd_table_mutex);
644 EXPORT_SYMBOL_GPL(register_mtd_user);
647 * unregister_mtd_user - unregister a 'user' of MTD devices.
648 * @old: pointer to notifier info structure
650 * Removes a callback function pair from the list of 'users' to be
651 * notified upon addition or removal of MTD devices. Causes the
652 * 'remove' callback to be immediately invoked for each MTD device
653 * currently present in the system.
655 int unregister_mtd_user (struct mtd_notifier *old)
657 struct mtd_info *mtd;
659 mutex_lock(&mtd_table_mutex);
661 module_put(THIS_MODULE);
663 mtd_for_each_device(mtd)
666 list_del(&old->list);
667 mutex_unlock(&mtd_table_mutex);
670 EXPORT_SYMBOL_GPL(unregister_mtd_user);
673 * get_mtd_device - obtain a validated handle for an MTD device
674 * @mtd: last known address of the required MTD device
675 * @num: internal device number of the required MTD device
677 * Given a number and NULL address, return the num'th entry in the device
678 * table, if any. Given an address and num == -1, search the device table
679 * for a device with that address and return if it's still present. Given
680 * both, return the num'th driver only if its address matches. Return
683 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
685 struct mtd_info *ret = NULL, *other;
688 mutex_lock(&mtd_table_mutex);
691 mtd_for_each_device(other) {
697 } else if (num >= 0) {
698 ret = idr_find(&mtd_idr, num);
699 if (mtd && mtd != ret)
708 err = __get_mtd_device(ret);
712 mutex_unlock(&mtd_table_mutex);
715 EXPORT_SYMBOL_GPL(get_mtd_device);
718 int __get_mtd_device(struct mtd_info *mtd)
722 if (!try_module_get(mtd->owner))
725 if (mtd->_get_device) {
726 err = mtd->_get_device(mtd);
729 module_put(mtd->owner);
736 EXPORT_SYMBOL_GPL(__get_mtd_device);
739 * get_mtd_device_nm - obtain a validated handle for an MTD device by
741 * @name: MTD device name to open
743 * This function returns MTD device description structure in case of
744 * success and an error code in case of failure.
746 struct mtd_info *get_mtd_device_nm(const char *name)
749 struct mtd_info *mtd = NULL, *other;
751 mutex_lock(&mtd_table_mutex);
753 mtd_for_each_device(other) {
754 if (!strcmp(name, other->name)) {
763 err = __get_mtd_device(mtd);
767 mutex_unlock(&mtd_table_mutex);
771 mutex_unlock(&mtd_table_mutex);
774 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
776 void put_mtd_device(struct mtd_info *mtd)
778 mutex_lock(&mtd_table_mutex);
779 __put_mtd_device(mtd);
780 mutex_unlock(&mtd_table_mutex);
783 EXPORT_SYMBOL_GPL(put_mtd_device);
785 void __put_mtd_device(struct mtd_info *mtd)
788 BUG_ON(mtd->usecount < 0);
790 if (mtd->_put_device)
791 mtd->_put_device(mtd);
793 module_put(mtd->owner);
795 EXPORT_SYMBOL_GPL(__put_mtd_device);
798 * Erase is an asynchronous operation. Device drivers are supposed
799 * to call instr->callback() whenever the operation completes, even
800 * if it completes with a failure.
801 * Callers are supposed to pass a callback function and wait for it
802 * to be called before writing to the block.
804 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
806 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
808 if (!(mtd->flags & MTD_WRITEABLE))
810 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
812 instr->state = MTD_ERASE_DONE;
813 mtd_erase_callback(instr);
816 return mtd->_erase(mtd, instr);
818 EXPORT_SYMBOL_GPL(mtd_erase);
821 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
823 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
824 void **virt, resource_size_t *phys)
832 if (from < 0 || from >= mtd->size || len > mtd->size - from)
836 return mtd->_point(mtd, from, len, retlen, virt, phys);
838 EXPORT_SYMBOL_GPL(mtd_point);
840 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
841 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
845 if (from < 0 || from >= mtd->size || len > mtd->size - from)
849 return mtd->_unpoint(mtd, from, len);
851 EXPORT_SYMBOL_GPL(mtd_unpoint);
854 * Allow NOMMU mmap() to directly map the device (if not NULL)
855 * - return the address to which the offset maps
856 * - return -ENOSYS to indicate refusal to do the mapping
858 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
859 unsigned long offset, unsigned long flags)
861 if (!mtd->_get_unmapped_area)
863 if (offset >= mtd->size || len > mtd->size - offset)
865 return mtd->_get_unmapped_area(mtd, len, offset, flags);
867 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
869 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
874 if (from < 0 || from >= mtd->size || len > mtd->size - from)
880 * In the absence of an error, drivers return a non-negative integer
881 * representing the maximum number of bitflips that were corrected on
882 * any one ecc region (if applicable; zero otherwise).
884 ret_code = mtd->_read(mtd, from, len, retlen, buf);
885 if (unlikely(ret_code < 0))
887 if (mtd->ecc_strength == 0)
888 return 0; /* device lacks ecc */
889 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
891 EXPORT_SYMBOL_GPL(mtd_read);
893 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
897 if (to < 0 || to >= mtd->size || len > mtd->size - to)
899 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
903 return mtd->_write(mtd, to, len, retlen, buf);
905 EXPORT_SYMBOL_GPL(mtd_write);
908 * In blackbox flight recorder like scenarios we want to make successful writes
909 * in interrupt context. panic_write() is only intended to be called when its
910 * known the kernel is about to panic and we need the write to succeed. Since
911 * the kernel is not going to be running for much longer, this function can
912 * break locks and delay to ensure the write succeeds (but not sleep).
914 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
918 if (!mtd->_panic_write)
920 if (to < 0 || to >= mtd->size || len > mtd->size - to)
922 if (!(mtd->flags & MTD_WRITEABLE))
926 return mtd->_panic_write(mtd, to, len, retlen, buf);
928 EXPORT_SYMBOL_GPL(mtd_panic_write);
930 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
933 ops->retlen = ops->oobretlen = 0;
937 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
938 * similar to mtd->_read(), returning a non-negative integer
939 * representing max bitflips. In other cases, mtd->_read_oob() may
940 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
942 ret_code = mtd->_read_oob(mtd, from, ops);
943 if (unlikely(ret_code < 0))
945 if (mtd->ecc_strength == 0)
946 return 0; /* device lacks ecc */
947 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
949 EXPORT_SYMBOL_GPL(mtd_read_oob);
952 * Method to access the protection register area, present in some flash
953 * devices. The user data is one time programmable but the factory data is read
956 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
957 struct otp_info *buf)
959 if (!mtd->_get_fact_prot_info)
963 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
965 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
967 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
968 size_t *retlen, u_char *buf)
971 if (!mtd->_read_fact_prot_reg)
975 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
977 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
979 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
980 struct otp_info *buf)
982 if (!mtd->_get_user_prot_info)
986 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
988 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
990 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
991 size_t *retlen, u_char *buf)
994 if (!mtd->_read_user_prot_reg)
998 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1000 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1002 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1003 size_t *retlen, u_char *buf)
1008 if (!mtd->_write_user_prot_reg)
1012 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1017 * If no data could be written at all, we are out of memory and
1018 * must return -ENOSPC.
1020 return (*retlen) ? 0 : -ENOSPC;
1022 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1024 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1026 if (!mtd->_lock_user_prot_reg)
1030 return mtd->_lock_user_prot_reg(mtd, from, len);
1032 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1034 /* Chip-supported device locking */
1035 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1039 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1043 return mtd->_lock(mtd, ofs, len);
1045 EXPORT_SYMBOL_GPL(mtd_lock);
1047 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1051 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1055 return mtd->_unlock(mtd, ofs, len);
1057 EXPORT_SYMBOL_GPL(mtd_unlock);
1059 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1061 if (!mtd->_is_locked)
1063 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1067 return mtd->_is_locked(mtd, ofs, len);
1069 EXPORT_SYMBOL_GPL(mtd_is_locked);
1071 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1073 if (ofs < 0 || ofs >= mtd->size)
1075 if (!mtd->_block_isreserved)
1077 return mtd->_block_isreserved(mtd, ofs);
1079 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1081 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1083 if (ofs < 0 || ofs >= mtd->size)
1085 if (!mtd->_block_isbad)
1087 return mtd->_block_isbad(mtd, ofs);
1089 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1091 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1093 if (!mtd->_block_markbad)
1095 if (ofs < 0 || ofs >= mtd->size)
1097 if (!(mtd->flags & MTD_WRITEABLE))
1099 return mtd->_block_markbad(mtd, ofs);
1101 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1104 * default_mtd_writev - the default writev method
1105 * @mtd: mtd device description object pointer
1106 * @vecs: the vectors to write
1107 * @count: count of vectors in @vecs
1108 * @to: the MTD device offset to write to
1109 * @retlen: on exit contains the count of bytes written to the MTD device.
1111 * This function returns zero in case of success and a negative error code in
1114 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1115 unsigned long count, loff_t to, size_t *retlen)
1118 size_t totlen = 0, thislen;
1121 for (i = 0; i < count; i++) {
1122 if (!vecs[i].iov_len)
1124 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1127 if (ret || thislen != vecs[i].iov_len)
1129 to += vecs[i].iov_len;
1136 * mtd_writev - the vector-based MTD write method
1137 * @mtd: mtd device description object pointer
1138 * @vecs: the vectors to write
1139 * @count: count of vectors in @vecs
1140 * @to: the MTD device offset to write to
1141 * @retlen: on exit contains the count of bytes written to the MTD device.
1143 * This function returns zero in case of success and a negative error code in
1146 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1147 unsigned long count, loff_t to, size_t *retlen)
1150 if (!(mtd->flags & MTD_WRITEABLE))
1153 return default_mtd_writev(mtd, vecs, count, to, retlen);
1154 return mtd->_writev(mtd, vecs, count, to, retlen);
1156 EXPORT_SYMBOL_GPL(mtd_writev);
1159 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1160 * @mtd: mtd device description object pointer
1161 * @size: a pointer to the ideal or maximum size of the allocation, points
1162 * to the actual allocation size on success.
1164 * This routine attempts to allocate a contiguous kernel buffer up to
1165 * the specified size, backing off the size of the request exponentially
1166 * until the request succeeds or until the allocation size falls below
1167 * the system page size. This attempts to make sure it does not adversely
1168 * impact system performance, so when allocating more than one page, we
1169 * ask the memory allocator to avoid re-trying, swapping, writing back
1170 * or performing I/O.
1172 * Note, this function also makes sure that the allocated buffer is aligned to
1173 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1175 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1176 * to handle smaller (i.e. degraded) buffer allocations under low- or
1177 * fragmented-memory situations where such reduced allocations, from a
1178 * requested ideal, are allowed.
1180 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1182 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1184 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
1185 __GFP_NORETRY | __GFP_NO_KSWAPD;
1186 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1189 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1191 while (*size > min_alloc) {
1192 kbuf = kmalloc(*size, flags);
1197 *size = ALIGN(*size, mtd->writesize);
1201 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1202 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1204 return kmalloc(*size, GFP_KERNEL);
1206 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1208 #ifdef CONFIG_PROC_FS
1210 /*====================================================================*/
1211 /* Support for /proc/mtd */
1213 static int mtd_proc_show(struct seq_file *m, void *v)
1215 struct mtd_info *mtd;
1217 seq_puts(m, "dev: size erasesize name\n");
1218 mutex_lock(&mtd_table_mutex);
1219 mtd_for_each_device(mtd) {
1220 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1221 mtd->index, (unsigned long long)mtd->size,
1222 mtd->erasesize, mtd->name);
1224 mutex_unlock(&mtd_table_mutex);
1228 static int mtd_proc_open(struct inode *inode, struct file *file)
1230 return single_open(file, mtd_proc_show, NULL);
1233 static const struct file_operations mtd_proc_ops = {
1234 .open = mtd_proc_open,
1236 .llseek = seq_lseek,
1237 .release = single_release,
1239 #endif /* CONFIG_PROC_FS */
1241 /*====================================================================*/
1244 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1248 ret = bdi_init(bdi);
1250 ret = bdi_register(bdi, NULL, "%s", name);
1258 static struct proc_dir_entry *proc_mtd;
1260 static int __init init_mtd(void)
1264 ret = class_register(&mtd_class);
1268 ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
1272 ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
1276 ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
1280 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1282 ret = init_mtdchar();
1290 remove_proc_entry("mtd", NULL);
1292 bdi_destroy(&mtd_bdi_ro_mappable);
1294 bdi_destroy(&mtd_bdi_unmappable);
1296 class_unregister(&mtd_class);
1298 pr_err("Error registering mtd class or bdi: %d\n", ret);
1302 static void __exit cleanup_mtd(void)
1306 remove_proc_entry("mtd", NULL);
1307 class_unregister(&mtd_class);
1308 bdi_destroy(&mtd_bdi_unmappable);
1309 bdi_destroy(&mtd_bdi_ro_mappable);
1310 bdi_destroy(&mtd_bdi_rw_mappable);
1313 module_init(init_mtd);
1314 module_exit(cleanup_mtd);
1316 MODULE_LICENSE("GPL");
1317 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1318 MODULE_DESCRIPTION("Core MTD registration and access routines");