2 * Core registration and callback routines for MTD
5 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
6 * Copyright © 2006 Red Hat UK Limited
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
24 #include <linux/module.h>
25 #include <linux/kernel.h>
26 #include <linux/ptrace.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/timer.h>
30 #include <linux/major.h>
32 #include <linux/err.h>
33 #include <linux/ioctl.h>
34 #include <linux/init.h>
36 #include <linux/proc_fs.h>
37 #include <linux/idr.h>
38 #include <linux/backing-dev.h>
39 #include <linux/gfp.h>
40 #include <linux/slab.h>
41 #include <linux/reboot.h>
42 #include <linux/kconfig.h>
43 #include <linux/leds.h>
45 #include <linux/mtd/mtd.h>
46 #include <linux/mtd/partitions.h>
50 static struct backing_dev_info mtd_bdi = {
53 #ifdef CONFIG_PM_SLEEP
55 static int mtd_cls_suspend(struct device *dev)
57 struct mtd_info *mtd = dev_get_drvdata(dev);
59 return mtd ? mtd_suspend(mtd) : 0;
62 static int mtd_cls_resume(struct device *dev)
64 struct mtd_info *mtd = dev_get_drvdata(dev);
71 static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
72 #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
74 #define MTD_CLS_PM_OPS NULL
77 static struct class mtd_class = {
83 static DEFINE_IDR(mtd_idr);
85 /* These are exported solely for the purpose of mtd_blkdevs.c. You
86 should not use them for _anything_ else */
87 DEFINE_MUTEX(mtd_table_mutex);
88 EXPORT_SYMBOL_GPL(mtd_table_mutex);
90 struct mtd_info *__mtd_next_device(int i)
92 return idr_get_next(&mtd_idr, &i);
94 EXPORT_SYMBOL_GPL(__mtd_next_device);
96 static LIST_HEAD(mtd_notifiers);
99 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
101 /* REVISIT once MTD uses the driver model better, whoever allocates
102 * the mtd_info will probably want to use the release() hook...
104 static void mtd_release(struct device *dev)
106 struct mtd_info *mtd = dev_get_drvdata(dev);
107 dev_t index = MTD_DEVT(mtd->index);
109 /* remove /dev/mtdXro node */
110 device_destroy(&mtd_class, index + 1);
113 static ssize_t mtd_type_show(struct device *dev,
114 struct device_attribute *attr, char *buf)
116 struct mtd_info *mtd = dev_get_drvdata(dev);
141 case MTD_MLCNANDFLASH:
148 return snprintf(buf, PAGE_SIZE, "%s\n", type);
150 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
152 static ssize_t mtd_flags_show(struct device *dev,
153 struct device_attribute *attr, char *buf)
155 struct mtd_info *mtd = dev_get_drvdata(dev);
157 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
160 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
162 static ssize_t mtd_size_show(struct device *dev,
163 struct device_attribute *attr, char *buf)
165 struct mtd_info *mtd = dev_get_drvdata(dev);
167 return snprintf(buf, PAGE_SIZE, "%llu\n",
168 (unsigned long long)mtd->size);
171 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
173 static ssize_t mtd_erasesize_show(struct device *dev,
174 struct device_attribute *attr, char *buf)
176 struct mtd_info *mtd = dev_get_drvdata(dev);
178 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
181 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
183 static ssize_t mtd_writesize_show(struct device *dev,
184 struct device_attribute *attr, char *buf)
186 struct mtd_info *mtd = dev_get_drvdata(dev);
188 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
191 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
193 static ssize_t mtd_subpagesize_show(struct device *dev,
194 struct device_attribute *attr, char *buf)
196 struct mtd_info *mtd = dev_get_drvdata(dev);
197 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
199 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
202 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
204 static ssize_t mtd_oobsize_show(struct device *dev,
205 struct device_attribute *attr, char *buf)
207 struct mtd_info *mtd = dev_get_drvdata(dev);
209 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
212 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
214 static ssize_t mtd_numeraseregions_show(struct device *dev,
215 struct device_attribute *attr, char *buf)
217 struct mtd_info *mtd = dev_get_drvdata(dev);
219 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
222 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
225 static ssize_t mtd_name_show(struct device *dev,
226 struct device_attribute *attr, char *buf)
228 struct mtd_info *mtd = dev_get_drvdata(dev);
230 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
233 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
235 static ssize_t mtd_ecc_strength_show(struct device *dev,
236 struct device_attribute *attr, char *buf)
238 struct mtd_info *mtd = dev_get_drvdata(dev);
240 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
242 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
244 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
245 struct device_attribute *attr,
248 struct mtd_info *mtd = dev_get_drvdata(dev);
250 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
253 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
254 struct device_attribute *attr,
255 const char *buf, size_t count)
257 struct mtd_info *mtd = dev_get_drvdata(dev);
258 unsigned int bitflip_threshold;
261 retval = kstrtouint(buf, 0, &bitflip_threshold);
265 mtd->bitflip_threshold = bitflip_threshold;
268 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
269 mtd_bitflip_threshold_show,
270 mtd_bitflip_threshold_store);
272 static ssize_t mtd_ecc_step_size_show(struct device *dev,
273 struct device_attribute *attr, char *buf)
275 struct mtd_info *mtd = dev_get_drvdata(dev);
277 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
280 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
282 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
283 struct device_attribute *attr, char *buf)
285 struct mtd_info *mtd = dev_get_drvdata(dev);
286 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
288 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
290 static DEVICE_ATTR(corrected_bits, S_IRUGO,
291 mtd_ecc_stats_corrected_show, NULL);
293 static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
294 struct device_attribute *attr, char *buf)
296 struct mtd_info *mtd = dev_get_drvdata(dev);
297 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
299 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
301 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
303 static ssize_t mtd_badblocks_show(struct device *dev,
304 struct device_attribute *attr, char *buf)
306 struct mtd_info *mtd = dev_get_drvdata(dev);
307 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
309 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
311 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
313 static ssize_t mtd_bbtblocks_show(struct device *dev,
314 struct device_attribute *attr, char *buf)
316 struct mtd_info *mtd = dev_get_drvdata(dev);
317 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
319 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
321 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
323 static struct attribute *mtd_attrs[] = {
325 &dev_attr_flags.attr,
327 &dev_attr_erasesize.attr,
328 &dev_attr_writesize.attr,
329 &dev_attr_subpagesize.attr,
330 &dev_attr_oobsize.attr,
331 &dev_attr_numeraseregions.attr,
333 &dev_attr_ecc_strength.attr,
334 &dev_attr_ecc_step_size.attr,
335 &dev_attr_corrected_bits.attr,
336 &dev_attr_ecc_failures.attr,
337 &dev_attr_bad_blocks.attr,
338 &dev_attr_bbt_blocks.attr,
339 &dev_attr_bitflip_threshold.attr,
342 ATTRIBUTE_GROUPS(mtd);
344 static struct device_type mtd_devtype = {
346 .groups = mtd_groups,
347 .release = mtd_release,
351 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
355 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
356 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
358 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
361 return NOMMU_MAP_COPY;
364 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
367 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
370 struct mtd_info *mtd;
372 mtd = container_of(n, struct mtd_info, reboot_notifier);
379 * mtd_wunit_to_pairing_info - get pairing information of a wunit
380 * @mtd: pointer to new MTD device info structure
381 * @wunit: write unit we are interested in
382 * @info: returned pairing information
384 * Retrieve pairing information associated to the wunit.
385 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
386 * paired together, and where programming a page may influence the page it is
388 * The notion of page is replaced by the term wunit (write-unit) to stay
389 * consistent with the ->writesize field.
391 * The @wunit argument can be extracted from an absolute offset using
392 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
395 * From the pairing info the MTD user can find all the wunits paired with
396 * @wunit using the following loop:
398 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
400 * mtd_pairing_info_to_wunit(mtd, &info);
404 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
405 struct mtd_pairing_info *info)
407 int npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
409 if (wunit < 0 || wunit >= npairs)
412 if (mtd->pairing && mtd->pairing->get_info)
413 return mtd->pairing->get_info(mtd, wunit, info);
420 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
423 * mtd_wunit_to_pairing_info - get wunit from pairing information
424 * @mtd: pointer to new MTD device info structure
425 * @info: pairing information struct
427 * Returns a positive number representing the wunit associated to the info
428 * struct, or a negative error code.
430 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
431 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
434 * It can also be used to only program the first page of each pair (i.e.
435 * page attached to group 0), which allows one to use an MLC NAND in
436 * software-emulated SLC mode:
439 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
440 * for (info.pair = 0; info.pair < npairs; info.pair++) {
441 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
442 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
443 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
446 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
447 const struct mtd_pairing_info *info)
449 int ngroups = mtd_pairing_groups(mtd);
450 int npairs = mtd_wunit_per_eb(mtd) / ngroups;
452 if (!info || info->pair < 0 || info->pair >= npairs ||
453 info->group < 0 || info->group >= ngroups)
456 if (mtd->pairing && mtd->pairing->get_wunit)
457 return mtd->pairing->get_wunit(mtd, info);
461 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
464 * mtd_pairing_groups - get the number of pairing groups
465 * @mtd: pointer to new MTD device info structure
467 * Returns the number of pairing groups.
469 * This number is usually equal to the number of bits exposed by a single
470 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
471 * to iterate over all pages of a given pair.
473 int mtd_pairing_groups(struct mtd_info *mtd)
475 if (!mtd->pairing || !mtd->pairing->ngroups)
478 return mtd->pairing->ngroups;
480 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
483 * add_mtd_device - register an MTD device
484 * @mtd: pointer to new MTD device info structure
486 * Add a device to the list of MTD devices present in the system, and
487 * notify each currently active MTD 'user' of its arrival. Returns
488 * zero on success or non-zero on failure.
491 int add_mtd_device(struct mtd_info *mtd)
493 struct mtd_notifier *not;
497 * May occur, for instance, on buggy drivers which call
498 * mtd_device_parse_register() multiple times on the same master MTD,
499 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
501 if (WARN_ONCE(mtd->backing_dev_info, "MTD already registered\n"))
504 mtd->backing_dev_info = &mtd_bdi;
506 BUG_ON(mtd->writesize == 0);
507 mutex_lock(&mtd_table_mutex);
509 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
518 /* default value if not set by driver */
519 if (mtd->bitflip_threshold == 0)
520 mtd->bitflip_threshold = mtd->ecc_strength;
522 if (is_power_of_2(mtd->erasesize))
523 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
525 mtd->erasesize_shift = 0;
527 if (is_power_of_2(mtd->writesize))
528 mtd->writesize_shift = ffs(mtd->writesize) - 1;
530 mtd->writesize_shift = 0;
532 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
533 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
535 /* Some chips always power up locked. Unlock them now */
536 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
537 error = mtd_unlock(mtd, 0, mtd->size);
538 if (error && error != -EOPNOTSUPP)
540 "%s: unlock failed, writes may not work\n",
542 /* Ignore unlock failures? */
546 /* Caller should have set dev.parent to match the
547 * physical device, if appropriate.
549 mtd->dev.type = &mtd_devtype;
550 mtd->dev.class = &mtd_class;
551 mtd->dev.devt = MTD_DEVT(i);
552 dev_set_name(&mtd->dev, "mtd%d", i);
553 dev_set_drvdata(&mtd->dev, mtd);
554 of_node_get(mtd_get_of_node(mtd));
555 error = device_register(&mtd->dev);
559 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
562 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
563 /* No need to get a refcount on the module containing
564 the notifier, since we hold the mtd_table_mutex */
565 list_for_each_entry(not, &mtd_notifiers, list)
568 mutex_unlock(&mtd_table_mutex);
569 /* We _know_ we aren't being removed, because
570 our caller is still holding us here. So none
571 of this try_ nonsense, and no bitching about it
573 __module_get(THIS_MODULE);
577 of_node_put(mtd_get_of_node(mtd));
578 idr_remove(&mtd_idr, i);
580 mutex_unlock(&mtd_table_mutex);
585 * del_mtd_device - unregister an MTD device
586 * @mtd: pointer to MTD device info structure
588 * Remove a device from the list of MTD devices present in the system,
589 * and notify each currently active MTD 'user' of its departure.
590 * Returns zero on success or 1 on failure, which currently will happen
591 * if the requested device does not appear to be present in the list.
594 int del_mtd_device(struct mtd_info *mtd)
597 struct mtd_notifier *not;
599 mutex_lock(&mtd_table_mutex);
601 if (idr_find(&mtd_idr, mtd->index) != mtd) {
606 /* No need to get a refcount on the module containing
607 the notifier, since we hold the mtd_table_mutex */
608 list_for_each_entry(not, &mtd_notifiers, list)
612 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
613 mtd->index, mtd->name, mtd->usecount);
616 device_unregister(&mtd->dev);
618 idr_remove(&mtd_idr, mtd->index);
619 of_node_put(mtd_get_of_node(mtd));
621 module_put(THIS_MODULE);
626 mutex_unlock(&mtd_table_mutex);
630 static int mtd_add_device_partitions(struct mtd_info *mtd,
631 struct mtd_partitions *parts)
633 const struct mtd_partition *real_parts = parts->parts;
634 int nbparts = parts->nr_parts;
637 if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
638 ret = add_mtd_device(mtd);
644 ret = add_mtd_partitions(mtd, real_parts, nbparts);
645 if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
654 * Set a few defaults based on the parent devices, if not provided by the
657 static void mtd_set_dev_defaults(struct mtd_info *mtd)
659 if (mtd->dev.parent) {
660 if (!mtd->owner && mtd->dev.parent->driver)
661 mtd->owner = mtd->dev.parent->driver->owner;
663 mtd->name = dev_name(mtd->dev.parent);
665 pr_debug("mtd device won't show a device symlink in sysfs\n");
670 * mtd_device_parse_register - parse partitions and register an MTD device.
672 * @mtd: the MTD device to register
673 * @types: the list of MTD partition probes to try, see
674 * 'parse_mtd_partitions()' for more information
675 * @parser_data: MTD partition parser-specific data
676 * @parts: fallback partition information to register, if parsing fails;
677 * only valid if %nr_parts > %0
678 * @nr_parts: the number of partitions in parts, if zero then the full
679 * MTD device is registered if no partition info is found
681 * This function aggregates MTD partitions parsing (done by
682 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
683 * basically follows the most common pattern found in many MTD drivers:
685 * * It first tries to probe partitions on MTD device @mtd using parsers
686 * specified in @types (if @types is %NULL, then the default list of parsers
687 * is used, see 'parse_mtd_partitions()' for more information). If none are
688 * found this functions tries to fallback to information specified in
690 * * If any partitioning info was found, this function registers the found
691 * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
692 * as a whole is registered first.
693 * * If no partitions were found this function just registers the MTD device
696 * Returns zero in case of success and a negative error code in case of failure.
698 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
699 struct mtd_part_parser_data *parser_data,
700 const struct mtd_partition *parts,
703 struct mtd_partitions parsed;
706 mtd_set_dev_defaults(mtd);
708 memset(&parsed, 0, sizeof(parsed));
710 ret = parse_mtd_partitions(mtd, types, &parsed, parser_data);
711 if ((ret < 0 || parsed.nr_parts == 0) && parts && nr_parts) {
712 /* Fall back to driver-provided partitions */
713 parsed = (struct mtd_partitions){
715 .nr_parts = nr_parts,
717 } else if (ret < 0) {
718 /* Didn't come up with parsed OR fallback partitions */
719 pr_info("mtd: failed to find partitions; one or more parsers reports errors (%d)\n",
721 /* Don't abort on errors; we can still use unpartitioned MTD */
722 memset(&parsed, 0, sizeof(parsed));
725 ret = mtd_add_device_partitions(mtd, &parsed);
730 * FIXME: some drivers unfortunately call this function more than once.
731 * So we have to check if we've already assigned the reboot notifier.
733 * Generally, we can make multiple calls work for most cases, but it
734 * does cause problems with parse_mtd_partitions() above (e.g.,
735 * cmdlineparts will register partitions more than once).
737 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
738 "MTD already registered\n");
739 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
740 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
741 register_reboot_notifier(&mtd->reboot_notifier);
745 /* Cleanup any parsed partitions */
746 mtd_part_parser_cleanup(&parsed);
749 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
752 * mtd_device_unregister - unregister an existing MTD device.
754 * @master: the MTD device to unregister. This will unregister both the master
755 * and any partitions if registered.
757 int mtd_device_unregister(struct mtd_info *master)
762 unregister_reboot_notifier(&master->reboot_notifier);
764 err = del_mtd_partitions(master);
768 if (!device_is_registered(&master->dev))
771 return del_mtd_device(master);
773 EXPORT_SYMBOL_GPL(mtd_device_unregister);
776 * register_mtd_user - register a 'user' of MTD devices.
777 * @new: pointer to notifier info structure
779 * Registers a pair of callbacks function to be called upon addition
780 * or removal of MTD devices. Causes the 'add' callback to be immediately
781 * invoked for each MTD device currently present in the system.
783 void register_mtd_user (struct mtd_notifier *new)
785 struct mtd_info *mtd;
787 mutex_lock(&mtd_table_mutex);
789 list_add(&new->list, &mtd_notifiers);
791 __module_get(THIS_MODULE);
793 mtd_for_each_device(mtd)
796 mutex_unlock(&mtd_table_mutex);
798 EXPORT_SYMBOL_GPL(register_mtd_user);
801 * unregister_mtd_user - unregister a 'user' of MTD devices.
802 * @old: pointer to notifier info structure
804 * Removes a callback function pair from the list of 'users' to be
805 * notified upon addition or removal of MTD devices. Causes the
806 * 'remove' callback to be immediately invoked for each MTD device
807 * currently present in the system.
809 int unregister_mtd_user (struct mtd_notifier *old)
811 struct mtd_info *mtd;
813 mutex_lock(&mtd_table_mutex);
815 module_put(THIS_MODULE);
817 mtd_for_each_device(mtd)
820 list_del(&old->list);
821 mutex_unlock(&mtd_table_mutex);
824 EXPORT_SYMBOL_GPL(unregister_mtd_user);
827 * get_mtd_device - obtain a validated handle for an MTD device
828 * @mtd: last known address of the required MTD device
829 * @num: internal device number of the required MTD device
831 * Given a number and NULL address, return the num'th entry in the device
832 * table, if any. Given an address and num == -1, search the device table
833 * for a device with that address and return if it's still present. Given
834 * both, return the num'th driver only if its address matches. Return
837 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
839 struct mtd_info *ret = NULL, *other;
842 mutex_lock(&mtd_table_mutex);
845 mtd_for_each_device(other) {
851 } else if (num >= 0) {
852 ret = idr_find(&mtd_idr, num);
853 if (mtd && mtd != ret)
862 err = __get_mtd_device(ret);
866 mutex_unlock(&mtd_table_mutex);
869 EXPORT_SYMBOL_GPL(get_mtd_device);
872 int __get_mtd_device(struct mtd_info *mtd)
876 if (!try_module_get(mtd->owner))
879 if (mtd->_get_device) {
880 err = mtd->_get_device(mtd);
883 module_put(mtd->owner);
890 EXPORT_SYMBOL_GPL(__get_mtd_device);
893 * get_mtd_device_nm - obtain a validated handle for an MTD device by
895 * @name: MTD device name to open
897 * This function returns MTD device description structure in case of
898 * success and an error code in case of failure.
900 struct mtd_info *get_mtd_device_nm(const char *name)
903 struct mtd_info *mtd = NULL, *other;
905 mutex_lock(&mtd_table_mutex);
907 mtd_for_each_device(other) {
908 if (!strcmp(name, other->name)) {
917 err = __get_mtd_device(mtd);
921 mutex_unlock(&mtd_table_mutex);
925 mutex_unlock(&mtd_table_mutex);
928 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
930 void put_mtd_device(struct mtd_info *mtd)
932 mutex_lock(&mtd_table_mutex);
933 __put_mtd_device(mtd);
934 mutex_unlock(&mtd_table_mutex);
937 EXPORT_SYMBOL_GPL(put_mtd_device);
939 void __put_mtd_device(struct mtd_info *mtd)
942 BUG_ON(mtd->usecount < 0);
944 if (mtd->_put_device)
945 mtd->_put_device(mtd);
947 module_put(mtd->owner);
949 EXPORT_SYMBOL_GPL(__put_mtd_device);
952 * Erase is an asynchronous operation. Device drivers are supposed
953 * to call instr->callback() whenever the operation completes, even
954 * if it completes with a failure.
955 * Callers are supposed to pass a callback function and wait for it
956 * to be called before writing to the block.
958 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
960 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
962 if (!(mtd->flags & MTD_WRITEABLE))
964 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
966 instr->state = MTD_ERASE_DONE;
967 mtd_erase_callback(instr);
970 ledtrig_mtd_activity();
971 return mtd->_erase(mtd, instr);
973 EXPORT_SYMBOL_GPL(mtd_erase);
976 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
978 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
979 void **virt, resource_size_t *phys)
987 if (from < 0 || from >= mtd->size || len > mtd->size - from)
991 return mtd->_point(mtd, from, len, retlen, virt, phys);
993 EXPORT_SYMBOL_GPL(mtd_point);
995 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
996 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1000 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1004 return mtd->_unpoint(mtd, from, len);
1006 EXPORT_SYMBOL_GPL(mtd_unpoint);
1009 * Allow NOMMU mmap() to directly map the device (if not NULL)
1010 * - return the address to which the offset maps
1011 * - return -ENOSYS to indicate refusal to do the mapping
1013 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1014 unsigned long offset, unsigned long flags)
1016 if (!mtd->_get_unmapped_area)
1018 if (offset >= mtd->size || len > mtd->size - offset)
1020 return mtd->_get_unmapped_area(mtd, len, offset, flags);
1022 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1024 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1029 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1034 ledtrig_mtd_activity();
1036 * In the absence of an error, drivers return a non-negative integer
1037 * representing the maximum number of bitflips that were corrected on
1038 * any one ecc region (if applicable; zero otherwise).
1040 ret_code = mtd->_read(mtd, from, len, retlen, buf);
1041 if (unlikely(ret_code < 0))
1043 if (mtd->ecc_strength == 0)
1044 return 0; /* device lacks ecc */
1045 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1047 EXPORT_SYMBOL_GPL(mtd_read);
1049 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1053 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1055 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
1059 ledtrig_mtd_activity();
1060 return mtd->_write(mtd, to, len, retlen, buf);
1062 EXPORT_SYMBOL_GPL(mtd_write);
1065 * In blackbox flight recorder like scenarios we want to make successful writes
1066 * in interrupt context. panic_write() is only intended to be called when its
1067 * known the kernel is about to panic and we need the write to succeed. Since
1068 * the kernel is not going to be running for much longer, this function can
1069 * break locks and delay to ensure the write succeeds (but not sleep).
1071 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1075 if (!mtd->_panic_write)
1077 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1079 if (!(mtd->flags & MTD_WRITEABLE))
1083 return mtd->_panic_write(mtd, to, len, retlen, buf);
1085 EXPORT_SYMBOL_GPL(mtd_panic_write);
1087 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1090 ops->retlen = ops->oobretlen = 0;
1091 if (!mtd->_read_oob)
1094 ledtrig_mtd_activity();
1096 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1097 * similar to mtd->_read(), returning a non-negative integer
1098 * representing max bitflips. In other cases, mtd->_read_oob() may
1099 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1101 ret_code = mtd->_read_oob(mtd, from, ops);
1102 if (unlikely(ret_code < 0))
1104 if (mtd->ecc_strength == 0)
1105 return 0; /* device lacks ecc */
1106 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1108 EXPORT_SYMBOL_GPL(mtd_read_oob);
1110 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1111 struct mtd_oob_ops *ops)
1113 ops->retlen = ops->oobretlen = 0;
1114 if (!mtd->_write_oob)
1116 if (!(mtd->flags & MTD_WRITEABLE))
1118 ledtrig_mtd_activity();
1119 return mtd->_write_oob(mtd, to, ops);
1121 EXPORT_SYMBOL_GPL(mtd_write_oob);
1124 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1125 * @mtd: MTD device structure
1126 * @section: ECC section. Depending on the layout you may have all the ECC
1127 * bytes stored in a single contiguous section, or one section
1128 * per ECC chunk (and sometime several sections for a single ECC
1130 * @oobecc: OOB region struct filled with the appropriate ECC position
1133 * This functions return ECC section information in the OOB area. I you want
1134 * to get all the ECC bytes information, then you should call
1135 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1137 * Returns zero on success, a negative error code otherwise.
1139 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1140 struct mtd_oob_region *oobecc)
1142 memset(oobecc, 0, sizeof(*oobecc));
1144 if (!mtd || section < 0)
1147 if (!mtd->ooblayout || !mtd->ooblayout->ecc)
1150 return mtd->ooblayout->ecc(mtd, section, oobecc);
1152 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1155 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1157 * @mtd: MTD device structure
1158 * @section: Free section you are interested in. Depending on the layout
1159 * you may have all the free bytes stored in a single contiguous
1160 * section, or one section per ECC chunk plus an extra section
1161 * for the remaining bytes (or other funky layout).
1162 * @oobfree: OOB region struct filled with the appropriate free position
1165 * This functions return free bytes position in the OOB area. I you want
1166 * to get all the free bytes information, then you should call
1167 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1169 * Returns zero on success, a negative error code otherwise.
1171 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1172 struct mtd_oob_region *oobfree)
1174 memset(oobfree, 0, sizeof(*oobfree));
1176 if (!mtd || section < 0)
1179 if (!mtd->ooblayout || !mtd->ooblayout->free)
1182 return mtd->ooblayout->free(mtd, section, oobfree);
1184 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1187 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1188 * @mtd: mtd info structure
1189 * @byte: the byte we are searching for
1190 * @sectionp: pointer where the section id will be stored
1191 * @oobregion: used to retrieve the ECC position
1192 * @iter: iterator function. Should be either mtd_ooblayout_free or
1193 * mtd_ooblayout_ecc depending on the region type you're searching for
1195 * This functions returns the section id and oobregion information of a
1196 * specific byte. For example, say you want to know where the 4th ECC byte is
1197 * stored, you'll use:
1199 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1201 * Returns zero on success, a negative error code otherwise.
1203 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1204 int *sectionp, struct mtd_oob_region *oobregion,
1205 int (*iter)(struct mtd_info *,
1207 struct mtd_oob_region *oobregion))
1209 int pos = 0, ret, section = 0;
1211 memset(oobregion, 0, sizeof(*oobregion));
1214 ret = iter(mtd, section, oobregion);
1218 if (pos + oobregion->length > byte)
1221 pos += oobregion->length;
1226 * Adjust region info to make it start at the beginning at the
1229 oobregion->offset += byte - pos;
1230 oobregion->length -= byte - pos;
1231 *sectionp = section;
1237 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1239 * @mtd: mtd info structure
1240 * @eccbyte: the byte we are searching for
1241 * @sectionp: pointer where the section id will be stored
1242 * @oobregion: OOB region information
1244 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1247 * Returns zero on success, a negative error code otherwise.
1249 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1251 struct mtd_oob_region *oobregion)
1253 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1256 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1259 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1260 * @mtd: mtd info structure
1261 * @buf: destination buffer to store OOB bytes
1262 * @oobbuf: OOB buffer
1263 * @start: first byte to retrieve
1264 * @nbytes: number of bytes to retrieve
1265 * @iter: section iterator
1267 * Extract bytes attached to a specific category (ECC or free)
1268 * from the OOB buffer and copy them into buf.
1270 * Returns zero on success, a negative error code otherwise.
1272 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1273 const u8 *oobbuf, int start, int nbytes,
1274 int (*iter)(struct mtd_info *,
1276 struct mtd_oob_region *oobregion))
1278 struct mtd_oob_region oobregion = { };
1279 int section = 0, ret;
1281 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1287 cnt = oobregion.length > nbytes ? nbytes : oobregion.length;
1288 memcpy(buf, oobbuf + oobregion.offset, cnt);
1295 ret = iter(mtd, ++section, &oobregion);
1302 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1303 * @mtd: mtd info structure
1304 * @buf: source buffer to get OOB bytes from
1305 * @oobbuf: OOB buffer
1306 * @start: first OOB byte to set
1307 * @nbytes: number of OOB bytes to set
1308 * @iter: section iterator
1310 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1311 * is selected by passing the appropriate iterator.
1313 * Returns zero on success, a negative error code otherwise.
1315 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1316 u8 *oobbuf, int start, int nbytes,
1317 int (*iter)(struct mtd_info *,
1319 struct mtd_oob_region *oobregion))
1321 struct mtd_oob_region oobregion = { };
1322 int section = 0, ret;
1324 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1330 cnt = oobregion.length > nbytes ? nbytes : oobregion.length;
1331 memcpy(oobbuf + oobregion.offset, buf, cnt);
1338 ret = iter(mtd, ++section, &oobregion);
1345 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1346 * @mtd: mtd info structure
1347 * @iter: category iterator
1349 * Count the number of bytes in a given category.
1351 * Returns a positive value on success, a negative error code otherwise.
1353 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1354 int (*iter)(struct mtd_info *,
1356 struct mtd_oob_region *oobregion))
1358 struct mtd_oob_region oobregion = { };
1359 int section = 0, ret, nbytes = 0;
1362 ret = iter(mtd, section++, &oobregion);
1369 nbytes += oobregion.length;
1376 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1377 * @mtd: mtd info structure
1378 * @eccbuf: destination buffer to store ECC bytes
1379 * @oobbuf: OOB buffer
1380 * @start: first ECC byte to retrieve
1381 * @nbytes: number of ECC bytes to retrieve
1383 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1385 * Returns zero on success, a negative error code otherwise.
1387 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1388 const u8 *oobbuf, int start, int nbytes)
1390 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1393 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1396 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1397 * @mtd: mtd info structure
1398 * @eccbuf: source buffer to get ECC bytes from
1399 * @oobbuf: OOB buffer
1400 * @start: first ECC byte to set
1401 * @nbytes: number of ECC bytes to set
1403 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1405 * Returns zero on success, a negative error code otherwise.
1407 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1408 u8 *oobbuf, int start, int nbytes)
1410 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1413 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1416 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1417 * @mtd: mtd info structure
1418 * @databuf: destination buffer to store ECC bytes
1419 * @oobbuf: OOB buffer
1420 * @start: first ECC byte to retrieve
1421 * @nbytes: number of ECC bytes to retrieve
1423 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1425 * Returns zero on success, a negative error code otherwise.
1427 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1428 const u8 *oobbuf, int start, int nbytes)
1430 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1431 mtd_ooblayout_free);
1433 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1436 * mtd_ooblayout_get_eccbytes - set data bytes into the oob buffer
1437 * @mtd: mtd info structure
1438 * @eccbuf: source buffer to get data bytes from
1439 * @oobbuf: OOB buffer
1440 * @start: first ECC byte to set
1441 * @nbytes: number of ECC bytes to set
1443 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1445 * Returns zero on success, a negative error code otherwise.
1447 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1448 u8 *oobbuf, int start, int nbytes)
1450 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1451 mtd_ooblayout_free);
1453 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1456 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1457 * @mtd: mtd info structure
1459 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1461 * Returns zero on success, a negative error code otherwise.
1463 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1465 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1467 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1470 * mtd_ooblayout_count_freebytes - count the number of ECC bytes in OOB
1471 * @mtd: mtd info structure
1473 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1475 * Returns zero on success, a negative error code otherwise.
1477 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1479 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1481 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1484 * Method to access the protection register area, present in some flash
1485 * devices. The user data is one time programmable but the factory data is read
1488 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1489 struct otp_info *buf)
1491 if (!mtd->_get_fact_prot_info)
1495 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1497 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1499 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1500 size_t *retlen, u_char *buf)
1503 if (!mtd->_read_fact_prot_reg)
1507 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1509 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1511 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1512 struct otp_info *buf)
1514 if (!mtd->_get_user_prot_info)
1518 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1520 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1522 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1523 size_t *retlen, u_char *buf)
1526 if (!mtd->_read_user_prot_reg)
1530 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1532 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1534 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1535 size_t *retlen, u_char *buf)
1540 if (!mtd->_write_user_prot_reg)
1544 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1549 * If no data could be written at all, we are out of memory and
1550 * must return -ENOSPC.
1552 return (*retlen) ? 0 : -ENOSPC;
1554 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1556 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1558 if (!mtd->_lock_user_prot_reg)
1562 return mtd->_lock_user_prot_reg(mtd, from, len);
1564 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1566 /* Chip-supported device locking */
1567 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1571 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1575 return mtd->_lock(mtd, ofs, len);
1577 EXPORT_SYMBOL_GPL(mtd_lock);
1579 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1583 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1587 return mtd->_unlock(mtd, ofs, len);
1589 EXPORT_SYMBOL_GPL(mtd_unlock);
1591 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1593 if (!mtd->_is_locked)
1595 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1599 return mtd->_is_locked(mtd, ofs, len);
1601 EXPORT_SYMBOL_GPL(mtd_is_locked);
1603 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1605 if (ofs < 0 || ofs >= mtd->size)
1607 if (!mtd->_block_isreserved)
1609 return mtd->_block_isreserved(mtd, ofs);
1611 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1613 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1615 if (ofs < 0 || ofs >= mtd->size)
1617 if (!mtd->_block_isbad)
1619 return mtd->_block_isbad(mtd, ofs);
1621 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1623 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1625 if (!mtd->_block_markbad)
1627 if (ofs < 0 || ofs >= mtd->size)
1629 if (!(mtd->flags & MTD_WRITEABLE))
1631 return mtd->_block_markbad(mtd, ofs);
1633 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1636 * default_mtd_writev - the default writev method
1637 * @mtd: mtd device description object pointer
1638 * @vecs: the vectors to write
1639 * @count: count of vectors in @vecs
1640 * @to: the MTD device offset to write to
1641 * @retlen: on exit contains the count of bytes written to the MTD device.
1643 * This function returns zero in case of success and a negative error code in
1646 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1647 unsigned long count, loff_t to, size_t *retlen)
1650 size_t totlen = 0, thislen;
1653 for (i = 0; i < count; i++) {
1654 if (!vecs[i].iov_len)
1656 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1659 if (ret || thislen != vecs[i].iov_len)
1661 to += vecs[i].iov_len;
1668 * mtd_writev - the vector-based MTD write method
1669 * @mtd: mtd device description object pointer
1670 * @vecs: the vectors to write
1671 * @count: count of vectors in @vecs
1672 * @to: the MTD device offset to write to
1673 * @retlen: on exit contains the count of bytes written to the MTD device.
1675 * This function returns zero in case of success and a negative error code in
1678 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1679 unsigned long count, loff_t to, size_t *retlen)
1682 if (!(mtd->flags & MTD_WRITEABLE))
1685 return default_mtd_writev(mtd, vecs, count, to, retlen);
1686 return mtd->_writev(mtd, vecs, count, to, retlen);
1688 EXPORT_SYMBOL_GPL(mtd_writev);
1691 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1692 * @mtd: mtd device description object pointer
1693 * @size: a pointer to the ideal or maximum size of the allocation, points
1694 * to the actual allocation size on success.
1696 * This routine attempts to allocate a contiguous kernel buffer up to
1697 * the specified size, backing off the size of the request exponentially
1698 * until the request succeeds or until the allocation size falls below
1699 * the system page size. This attempts to make sure it does not adversely
1700 * impact system performance, so when allocating more than one page, we
1701 * ask the memory allocator to avoid re-trying, swapping, writing back
1702 * or performing I/O.
1704 * Note, this function also makes sure that the allocated buffer is aligned to
1705 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1707 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1708 * to handle smaller (i.e. degraded) buffer allocations under low- or
1709 * fragmented-memory situations where such reduced allocations, from a
1710 * requested ideal, are allowed.
1712 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1714 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1716 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1717 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1720 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1722 while (*size > min_alloc) {
1723 kbuf = kmalloc(*size, flags);
1728 *size = ALIGN(*size, mtd->writesize);
1732 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1733 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1735 return kmalloc(*size, GFP_KERNEL);
1737 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1739 #ifdef CONFIG_PROC_FS
1741 /*====================================================================*/
1742 /* Support for /proc/mtd */
1744 static int mtd_proc_show(struct seq_file *m, void *v)
1746 struct mtd_info *mtd;
1748 seq_puts(m, "dev: size erasesize name\n");
1749 mutex_lock(&mtd_table_mutex);
1750 mtd_for_each_device(mtd) {
1751 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1752 mtd->index, (unsigned long long)mtd->size,
1753 mtd->erasesize, mtd->name);
1755 mutex_unlock(&mtd_table_mutex);
1759 static int mtd_proc_open(struct inode *inode, struct file *file)
1761 return single_open(file, mtd_proc_show, NULL);
1764 static const struct file_operations mtd_proc_ops = {
1765 .open = mtd_proc_open,
1767 .llseek = seq_lseek,
1768 .release = single_release,
1770 #endif /* CONFIG_PROC_FS */
1772 /*====================================================================*/
1775 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1779 ret = bdi_init(bdi);
1781 ret = bdi_register(bdi, NULL, "%s", name);
1789 static struct proc_dir_entry *proc_mtd;
1791 static int __init init_mtd(void)
1795 ret = class_register(&mtd_class);
1799 ret = mtd_bdi_init(&mtd_bdi, "mtd");
1803 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1805 ret = init_mtdchar();
1813 remove_proc_entry("mtd", NULL);
1815 class_unregister(&mtd_class);
1817 pr_err("Error registering mtd class or bdi: %d\n", ret);
1821 static void __exit cleanup_mtd(void)
1825 remove_proc_entry("mtd", NULL);
1826 class_unregister(&mtd_class);
1827 bdi_destroy(&mtd_bdi);
1828 idr_destroy(&mtd_idr);
1831 module_init(init_mtd);
1832 module_exit(cleanup_mtd);
1834 MODULE_LICENSE("GPL");
1835 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1836 MODULE_DESCRIPTION("Core MTD registration and access routines");