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/leds.h>
44 #include <linux/mtd/mtd.h>
45 #include <linux/mtd/partitions.h>
49 static struct backing_dev_info mtd_bdi = {
52 #ifdef CONFIG_PM_SLEEP
54 static int mtd_cls_suspend(struct device *dev)
56 struct mtd_info *mtd = dev_get_drvdata(dev);
58 return mtd ? mtd_suspend(mtd) : 0;
61 static int mtd_cls_resume(struct device *dev)
63 struct mtd_info *mtd = dev_get_drvdata(dev);
70 static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
71 #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
73 #define MTD_CLS_PM_OPS NULL
76 static struct class mtd_class = {
82 static DEFINE_IDR(mtd_idr);
84 /* These are exported solely for the purpose of mtd_blkdevs.c. You
85 should not use them for _anything_ else */
86 DEFINE_MUTEX(mtd_table_mutex);
87 EXPORT_SYMBOL_GPL(mtd_table_mutex);
89 struct mtd_info *__mtd_next_device(int i)
91 return idr_get_next(&mtd_idr, &i);
93 EXPORT_SYMBOL_GPL(__mtd_next_device);
95 static LIST_HEAD(mtd_notifiers);
98 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
100 /* REVISIT once MTD uses the driver model better, whoever allocates
101 * the mtd_info will probably want to use the release() hook...
103 static void mtd_release(struct device *dev)
105 struct mtd_info *mtd = dev_get_drvdata(dev);
106 dev_t index = MTD_DEVT(mtd->index);
108 /* remove /dev/mtdXro node */
109 device_destroy(&mtd_class, index + 1);
112 static ssize_t mtd_type_show(struct device *dev,
113 struct device_attribute *attr, char *buf)
115 struct mtd_info *mtd = dev_get_drvdata(dev);
140 case MTD_MLCNANDFLASH:
147 return snprintf(buf, PAGE_SIZE, "%s\n", type);
149 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
151 static ssize_t mtd_flags_show(struct device *dev,
152 struct device_attribute *attr, char *buf)
154 struct mtd_info *mtd = dev_get_drvdata(dev);
156 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
159 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
161 static ssize_t mtd_size_show(struct device *dev,
162 struct device_attribute *attr, char *buf)
164 struct mtd_info *mtd = dev_get_drvdata(dev);
166 return snprintf(buf, PAGE_SIZE, "%llu\n",
167 (unsigned long long)mtd->size);
170 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
172 static ssize_t mtd_erasesize_show(struct device *dev,
173 struct device_attribute *attr, char *buf)
175 struct mtd_info *mtd = dev_get_drvdata(dev);
177 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
180 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
182 static ssize_t mtd_writesize_show(struct device *dev,
183 struct device_attribute *attr, char *buf)
185 struct mtd_info *mtd = dev_get_drvdata(dev);
187 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
190 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
192 static ssize_t mtd_subpagesize_show(struct device *dev,
193 struct device_attribute *attr, char *buf)
195 struct mtd_info *mtd = dev_get_drvdata(dev);
196 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
198 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
201 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
203 static ssize_t mtd_oobsize_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
206 struct mtd_info *mtd = dev_get_drvdata(dev);
208 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
211 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
213 static ssize_t mtd_numeraseregions_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
216 struct mtd_info *mtd = dev_get_drvdata(dev);
218 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
221 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
224 static ssize_t mtd_name_show(struct device *dev,
225 struct device_attribute *attr, char *buf)
227 struct mtd_info *mtd = dev_get_drvdata(dev);
229 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
232 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
234 static ssize_t mtd_ecc_strength_show(struct device *dev,
235 struct device_attribute *attr, char *buf)
237 struct mtd_info *mtd = dev_get_drvdata(dev);
239 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
241 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
243 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
244 struct device_attribute *attr,
247 struct mtd_info *mtd = dev_get_drvdata(dev);
249 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
252 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
253 struct device_attribute *attr,
254 const char *buf, size_t count)
256 struct mtd_info *mtd = dev_get_drvdata(dev);
257 unsigned int bitflip_threshold;
260 retval = kstrtouint(buf, 0, &bitflip_threshold);
264 mtd->bitflip_threshold = bitflip_threshold;
267 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
268 mtd_bitflip_threshold_show,
269 mtd_bitflip_threshold_store);
271 static ssize_t mtd_ecc_step_size_show(struct device *dev,
272 struct device_attribute *attr, char *buf)
274 struct mtd_info *mtd = dev_get_drvdata(dev);
276 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
279 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
281 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
282 struct device_attribute *attr, char *buf)
284 struct mtd_info *mtd = dev_get_drvdata(dev);
285 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
287 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
289 static DEVICE_ATTR(corrected_bits, S_IRUGO,
290 mtd_ecc_stats_corrected_show, NULL);
292 static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
293 struct device_attribute *attr, char *buf)
295 struct mtd_info *mtd = dev_get_drvdata(dev);
296 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
298 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
300 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
302 static ssize_t mtd_badblocks_show(struct device *dev,
303 struct device_attribute *attr, char *buf)
305 struct mtd_info *mtd = dev_get_drvdata(dev);
306 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
308 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
310 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
312 static ssize_t mtd_bbtblocks_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->bbtblocks);
320 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
322 static struct attribute *mtd_attrs[] = {
324 &dev_attr_flags.attr,
326 &dev_attr_erasesize.attr,
327 &dev_attr_writesize.attr,
328 &dev_attr_subpagesize.attr,
329 &dev_attr_oobsize.attr,
330 &dev_attr_numeraseregions.attr,
332 &dev_attr_ecc_strength.attr,
333 &dev_attr_ecc_step_size.attr,
334 &dev_attr_corrected_bits.attr,
335 &dev_attr_ecc_failures.attr,
336 &dev_attr_bad_blocks.attr,
337 &dev_attr_bbt_blocks.attr,
338 &dev_attr_bitflip_threshold.attr,
341 ATTRIBUTE_GROUPS(mtd);
343 static struct device_type mtd_devtype = {
345 .groups = mtd_groups,
346 .release = mtd_release,
350 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
354 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
355 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
357 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
360 return NOMMU_MAP_COPY;
363 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
366 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
369 struct mtd_info *mtd;
371 mtd = container_of(n, struct mtd_info, reboot_notifier);
378 * mtd_wunit_to_pairing_info - get pairing information of a wunit
379 * @mtd: pointer to new MTD device info structure
380 * @wunit: write unit we are interested in
381 * @info: returned pairing information
383 * Retrieve pairing information associated to the wunit.
384 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
385 * paired together, and where programming a page may influence the page it is
387 * The notion of page is replaced by the term wunit (write-unit) to stay
388 * consistent with the ->writesize field.
390 * The @wunit argument can be extracted from an absolute offset using
391 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
394 * From the pairing info the MTD user can find all the wunits paired with
395 * @wunit using the following loop:
397 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
399 * mtd_pairing_info_to_wunit(mtd, &info);
403 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
404 struct mtd_pairing_info *info)
406 int npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
408 if (wunit < 0 || wunit >= npairs)
411 if (mtd->pairing && mtd->pairing->get_info)
412 return mtd->pairing->get_info(mtd, wunit, info);
419 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
422 * mtd_wunit_to_pairing_info - get wunit from pairing information
423 * @mtd: pointer to new MTD device info structure
424 * @info: pairing information struct
426 * Returns a positive number representing the wunit associated to the info
427 * struct, or a negative error code.
429 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
430 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
433 * It can also be used to only program the first page of each pair (i.e.
434 * page attached to group 0), which allows one to use an MLC NAND in
435 * software-emulated SLC mode:
438 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
439 * for (info.pair = 0; info.pair < npairs; info.pair++) {
440 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
441 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
442 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
445 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
446 const struct mtd_pairing_info *info)
448 int ngroups = mtd_pairing_groups(mtd);
449 int npairs = mtd_wunit_per_eb(mtd) / ngroups;
451 if (!info || info->pair < 0 || info->pair >= npairs ||
452 info->group < 0 || info->group >= ngroups)
455 if (mtd->pairing && mtd->pairing->get_wunit)
456 return mtd->pairing->get_wunit(mtd, info);
460 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
463 * mtd_pairing_groups - get the number of pairing groups
464 * @mtd: pointer to new MTD device info structure
466 * Returns the number of pairing groups.
468 * This number is usually equal to the number of bits exposed by a single
469 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
470 * to iterate over all pages of a given pair.
472 int mtd_pairing_groups(struct mtd_info *mtd)
474 if (!mtd->pairing || !mtd->pairing->ngroups)
477 return mtd->pairing->ngroups;
479 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
482 * add_mtd_device - register an MTD device
483 * @mtd: pointer to new MTD device info structure
485 * Add a device to the list of MTD devices present in the system, and
486 * notify each currently active MTD 'user' of its arrival. Returns
487 * zero on success or non-zero on failure.
490 int add_mtd_device(struct mtd_info *mtd)
492 struct mtd_notifier *not;
496 * May occur, for instance, on buggy drivers which call
497 * mtd_device_parse_register() multiple times on the same master MTD,
498 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
500 if (WARN_ONCE(mtd->backing_dev_info, "MTD already registered\n"))
503 mtd->backing_dev_info = &mtd_bdi;
505 BUG_ON(mtd->writesize == 0);
506 mutex_lock(&mtd_table_mutex);
508 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
517 /* default value if not set by driver */
518 if (mtd->bitflip_threshold == 0)
519 mtd->bitflip_threshold = mtd->ecc_strength;
521 if (is_power_of_2(mtd->erasesize))
522 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
524 mtd->erasesize_shift = 0;
526 if (is_power_of_2(mtd->writesize))
527 mtd->writesize_shift = ffs(mtd->writesize) - 1;
529 mtd->writesize_shift = 0;
531 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
532 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
534 /* Some chips always power up locked. Unlock them now */
535 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
536 error = mtd_unlock(mtd, 0, mtd->size);
537 if (error && error != -EOPNOTSUPP)
539 "%s: unlock failed, writes may not work\n",
541 /* Ignore unlock failures? */
545 /* Caller should have set dev.parent to match the
546 * physical device, if appropriate.
548 mtd->dev.type = &mtd_devtype;
549 mtd->dev.class = &mtd_class;
550 mtd->dev.devt = MTD_DEVT(i);
551 dev_set_name(&mtd->dev, "mtd%d", i);
552 dev_set_drvdata(&mtd->dev, mtd);
553 of_node_get(mtd_get_of_node(mtd));
554 error = device_register(&mtd->dev);
556 put_device(&mtd->dev);
560 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
563 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
564 /* No need to get a refcount on the module containing
565 the notifier, since we hold the mtd_table_mutex */
566 list_for_each_entry(not, &mtd_notifiers, list)
569 mutex_unlock(&mtd_table_mutex);
570 /* We _know_ we aren't being removed, because
571 our caller is still holding us here. So none
572 of this try_ nonsense, and no bitching about it
574 __module_get(THIS_MODULE);
578 of_node_put(mtd_get_of_node(mtd));
579 idr_remove(&mtd_idr, i);
581 mutex_unlock(&mtd_table_mutex);
586 * del_mtd_device - unregister an MTD device
587 * @mtd: pointer to MTD device info structure
589 * Remove a device from the list of MTD devices present in the system,
590 * and notify each currently active MTD 'user' of its departure.
591 * Returns zero on success or 1 on failure, which currently will happen
592 * if the requested device does not appear to be present in the list.
595 int del_mtd_device(struct mtd_info *mtd)
598 struct mtd_notifier *not;
600 mutex_lock(&mtd_table_mutex);
602 if (idr_find(&mtd_idr, mtd->index) != mtd) {
607 /* No need to get a refcount on the module containing
608 the notifier, since we hold the mtd_table_mutex */
609 list_for_each_entry(not, &mtd_notifiers, list)
613 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
614 mtd->index, mtd->name, mtd->usecount);
617 device_unregister(&mtd->dev);
619 idr_remove(&mtd_idr, mtd->index);
620 of_node_put(mtd_get_of_node(mtd));
622 module_put(THIS_MODULE);
627 mutex_unlock(&mtd_table_mutex);
631 static int mtd_add_device_partitions(struct mtd_info *mtd,
632 struct mtd_partitions *parts)
634 const struct mtd_partition *real_parts = parts->parts;
635 int nbparts = parts->nr_parts;
638 if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
639 ret = add_mtd_device(mtd);
645 ret = add_mtd_partitions(mtd, real_parts, nbparts);
646 if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
655 * Set a few defaults based on the parent devices, if not provided by the
658 static void mtd_set_dev_defaults(struct mtd_info *mtd)
660 if (mtd->dev.parent) {
661 if (!mtd->owner && mtd->dev.parent->driver)
662 mtd->owner = mtd->dev.parent->driver->owner;
664 mtd->name = dev_name(mtd->dev.parent);
666 pr_debug("mtd device won't show a device symlink in sysfs\n");
671 * mtd_device_parse_register - parse partitions and register an MTD device.
673 * @mtd: the MTD device to register
674 * @types: the list of MTD partition probes to try, see
675 * 'parse_mtd_partitions()' for more information
676 * @parser_data: MTD partition parser-specific data
677 * @parts: fallback partition information to register, if parsing fails;
678 * only valid if %nr_parts > %0
679 * @nr_parts: the number of partitions in parts, if zero then the full
680 * MTD device is registered if no partition info is found
682 * This function aggregates MTD partitions parsing (done by
683 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
684 * basically follows the most common pattern found in many MTD drivers:
686 * * It first tries to probe partitions on MTD device @mtd using parsers
687 * specified in @types (if @types is %NULL, then the default list of parsers
688 * is used, see 'parse_mtd_partitions()' for more information). If none are
689 * found this functions tries to fallback to information specified in
691 * * If any partitioning info was found, this function registers the found
692 * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
693 * as a whole is registered first.
694 * * If no partitions were found this function just registers the MTD device
697 * Returns zero in case of success and a negative error code in case of failure.
699 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
700 struct mtd_part_parser_data *parser_data,
701 const struct mtd_partition *parts,
704 struct mtd_partitions parsed;
707 mtd_set_dev_defaults(mtd);
709 memset(&parsed, 0, sizeof(parsed));
711 ret = parse_mtd_partitions(mtd, types, &parsed, parser_data);
712 if ((ret < 0 || parsed.nr_parts == 0) && parts && nr_parts) {
713 /* Fall back to driver-provided partitions */
714 parsed = (struct mtd_partitions){
716 .nr_parts = nr_parts,
718 } else if (ret < 0) {
719 /* Didn't come up with parsed OR fallback partitions */
720 pr_info("mtd: failed to find partitions; one or more parsers reports errors (%d)\n",
722 /* Don't abort on errors; we can still use unpartitioned MTD */
723 memset(&parsed, 0, sizeof(parsed));
726 ret = mtd_add_device_partitions(mtd, &parsed);
731 * FIXME: some drivers unfortunately call this function more than once.
732 * So we have to check if we've already assigned the reboot notifier.
734 * Generally, we can make multiple calls work for most cases, but it
735 * does cause problems with parse_mtd_partitions() above (e.g.,
736 * cmdlineparts will register partitions more than once).
738 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
739 "MTD already registered\n");
740 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
741 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
742 register_reboot_notifier(&mtd->reboot_notifier);
746 /* Cleanup any parsed partitions */
747 mtd_part_parser_cleanup(&parsed);
750 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
753 * mtd_device_unregister - unregister an existing MTD device.
755 * @master: the MTD device to unregister. This will unregister both the master
756 * and any partitions if registered.
758 int mtd_device_unregister(struct mtd_info *master)
763 unregister_reboot_notifier(&master->reboot_notifier);
765 err = del_mtd_partitions(master);
769 if (!device_is_registered(&master->dev))
772 return del_mtd_device(master);
774 EXPORT_SYMBOL_GPL(mtd_device_unregister);
777 * register_mtd_user - register a 'user' of MTD devices.
778 * @new: pointer to notifier info structure
780 * Registers a pair of callbacks function to be called upon addition
781 * or removal of MTD devices. Causes the 'add' callback to be immediately
782 * invoked for each MTD device currently present in the system.
784 void register_mtd_user (struct mtd_notifier *new)
786 struct mtd_info *mtd;
788 mutex_lock(&mtd_table_mutex);
790 list_add(&new->list, &mtd_notifiers);
792 __module_get(THIS_MODULE);
794 mtd_for_each_device(mtd)
797 mutex_unlock(&mtd_table_mutex);
799 EXPORT_SYMBOL_GPL(register_mtd_user);
802 * unregister_mtd_user - unregister a 'user' of MTD devices.
803 * @old: pointer to notifier info structure
805 * Removes a callback function pair from the list of 'users' to be
806 * notified upon addition or removal of MTD devices. Causes the
807 * 'remove' callback to be immediately invoked for each MTD device
808 * currently present in the system.
810 int unregister_mtd_user (struct mtd_notifier *old)
812 struct mtd_info *mtd;
814 mutex_lock(&mtd_table_mutex);
816 module_put(THIS_MODULE);
818 mtd_for_each_device(mtd)
821 list_del(&old->list);
822 mutex_unlock(&mtd_table_mutex);
825 EXPORT_SYMBOL_GPL(unregister_mtd_user);
828 * get_mtd_device - obtain a validated handle for an MTD device
829 * @mtd: last known address of the required MTD device
830 * @num: internal device number of the required MTD device
832 * Given a number and NULL address, return the num'th entry in the device
833 * table, if any. Given an address and num == -1, search the device table
834 * for a device with that address and return if it's still present. Given
835 * both, return the num'th driver only if its address matches. Return
838 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
840 struct mtd_info *ret = NULL, *other;
843 mutex_lock(&mtd_table_mutex);
846 mtd_for_each_device(other) {
852 } else if (num >= 0) {
853 ret = idr_find(&mtd_idr, num);
854 if (mtd && mtd != ret)
863 err = __get_mtd_device(ret);
867 mutex_unlock(&mtd_table_mutex);
870 EXPORT_SYMBOL_GPL(get_mtd_device);
873 int __get_mtd_device(struct mtd_info *mtd)
877 if (!try_module_get(mtd->owner))
880 if (mtd->_get_device) {
881 err = mtd->_get_device(mtd);
884 module_put(mtd->owner);
891 EXPORT_SYMBOL_GPL(__get_mtd_device);
894 * get_mtd_device_nm - obtain a validated handle for an MTD device by
896 * @name: MTD device name to open
898 * This function returns MTD device description structure in case of
899 * success and an error code in case of failure.
901 struct mtd_info *get_mtd_device_nm(const char *name)
904 struct mtd_info *mtd = NULL, *other;
906 mutex_lock(&mtd_table_mutex);
908 mtd_for_each_device(other) {
909 if (!strcmp(name, other->name)) {
918 err = __get_mtd_device(mtd);
922 mutex_unlock(&mtd_table_mutex);
926 mutex_unlock(&mtd_table_mutex);
929 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
931 void put_mtd_device(struct mtd_info *mtd)
933 mutex_lock(&mtd_table_mutex);
934 __put_mtd_device(mtd);
935 mutex_unlock(&mtd_table_mutex);
938 EXPORT_SYMBOL_GPL(put_mtd_device);
940 void __put_mtd_device(struct mtd_info *mtd)
943 BUG_ON(mtd->usecount < 0);
945 if (mtd->_put_device)
946 mtd->_put_device(mtd);
948 module_put(mtd->owner);
950 EXPORT_SYMBOL_GPL(__put_mtd_device);
953 * Erase is an asynchronous operation. Device drivers are supposed
954 * to call instr->callback() whenever the operation completes, even
955 * if it completes with a failure.
956 * Callers are supposed to pass a callback function and wait for it
957 * to be called before writing to the block.
959 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
961 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
963 if (!(mtd->flags & MTD_WRITEABLE))
965 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
967 instr->state = MTD_ERASE_DONE;
968 mtd_erase_callback(instr);
971 ledtrig_mtd_activity();
972 return mtd->_erase(mtd, instr);
974 EXPORT_SYMBOL_GPL(mtd_erase);
977 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
979 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
980 void **virt, resource_size_t *phys)
988 if (from < 0 || from >= mtd->size || len > mtd->size - from)
992 return mtd->_point(mtd, from, len, retlen, virt, phys);
994 EXPORT_SYMBOL_GPL(mtd_point);
996 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
997 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1001 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1005 return mtd->_unpoint(mtd, from, len);
1007 EXPORT_SYMBOL_GPL(mtd_unpoint);
1010 * Allow NOMMU mmap() to directly map the device (if not NULL)
1011 * - return the address to which the offset maps
1012 * - return -ENOSYS to indicate refusal to do the mapping
1014 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1015 unsigned long offset, unsigned long flags)
1017 if (!mtd->_get_unmapped_area)
1019 if (offset >= mtd->size || len > mtd->size - offset)
1021 return mtd->_get_unmapped_area(mtd, len, offset, flags);
1023 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1025 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1030 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1035 ledtrig_mtd_activity();
1037 * In the absence of an error, drivers return a non-negative integer
1038 * representing the maximum number of bitflips that were corrected on
1039 * any one ecc region (if applicable; zero otherwise).
1041 ret_code = mtd->_read(mtd, from, len, retlen, buf);
1042 if (unlikely(ret_code < 0))
1044 if (mtd->ecc_strength == 0)
1045 return 0; /* device lacks ecc */
1046 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1048 EXPORT_SYMBOL_GPL(mtd_read);
1050 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1054 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1056 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
1060 ledtrig_mtd_activity();
1061 return mtd->_write(mtd, to, len, retlen, buf);
1063 EXPORT_SYMBOL_GPL(mtd_write);
1066 * In blackbox flight recorder like scenarios we want to make successful writes
1067 * in interrupt context. panic_write() is only intended to be called when its
1068 * known the kernel is about to panic and we need the write to succeed. Since
1069 * the kernel is not going to be running for much longer, this function can
1070 * break locks and delay to ensure the write succeeds (but not sleep).
1072 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1076 if (!mtd->_panic_write)
1078 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1080 if (!(mtd->flags & MTD_WRITEABLE))
1084 return mtd->_panic_write(mtd, to, len, retlen, buf);
1086 EXPORT_SYMBOL_GPL(mtd_panic_write);
1088 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1091 ops->retlen = ops->oobretlen = 0;
1092 if (!mtd->_read_oob)
1095 ledtrig_mtd_activity();
1097 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1098 * similar to mtd->_read(), returning a non-negative integer
1099 * representing max bitflips. In other cases, mtd->_read_oob() may
1100 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1102 ret_code = mtd->_read_oob(mtd, from, ops);
1103 if (unlikely(ret_code < 0))
1105 if (mtd->ecc_strength == 0)
1106 return 0; /* device lacks ecc */
1107 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1109 EXPORT_SYMBOL_GPL(mtd_read_oob);
1111 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1112 struct mtd_oob_ops *ops)
1114 ops->retlen = ops->oobretlen = 0;
1115 if (!mtd->_write_oob)
1117 if (!(mtd->flags & MTD_WRITEABLE))
1119 ledtrig_mtd_activity();
1120 return mtd->_write_oob(mtd, to, ops);
1122 EXPORT_SYMBOL_GPL(mtd_write_oob);
1125 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1126 * @mtd: MTD device structure
1127 * @section: ECC section. Depending on the layout you may have all the ECC
1128 * bytes stored in a single contiguous section, or one section
1129 * per ECC chunk (and sometime several sections for a single ECC
1131 * @oobecc: OOB region struct filled with the appropriate ECC position
1134 * This functions return ECC section information in the OOB area. I you want
1135 * to get all the ECC bytes information, then you should call
1136 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1138 * Returns zero on success, a negative error code otherwise.
1140 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1141 struct mtd_oob_region *oobecc)
1143 memset(oobecc, 0, sizeof(*oobecc));
1145 if (!mtd || section < 0)
1148 if (!mtd->ooblayout || !mtd->ooblayout->ecc)
1151 return mtd->ooblayout->ecc(mtd, section, oobecc);
1153 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1156 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1158 * @mtd: MTD device structure
1159 * @section: Free section you are interested in. Depending on the layout
1160 * you may have all the free bytes stored in a single contiguous
1161 * section, or one section per ECC chunk plus an extra section
1162 * for the remaining bytes (or other funky layout).
1163 * @oobfree: OOB region struct filled with the appropriate free position
1166 * This functions return free bytes position in the OOB area. I you want
1167 * to get all the free bytes information, then you should call
1168 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1170 * Returns zero on success, a negative error code otherwise.
1172 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1173 struct mtd_oob_region *oobfree)
1175 memset(oobfree, 0, sizeof(*oobfree));
1177 if (!mtd || section < 0)
1180 if (!mtd->ooblayout || !mtd->ooblayout->free)
1183 return mtd->ooblayout->free(mtd, section, oobfree);
1185 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1188 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1189 * @mtd: mtd info structure
1190 * @byte: the byte we are searching for
1191 * @sectionp: pointer where the section id will be stored
1192 * @oobregion: used to retrieve the ECC position
1193 * @iter: iterator function. Should be either mtd_ooblayout_free or
1194 * mtd_ooblayout_ecc depending on the region type you're searching for
1196 * This functions returns the section id and oobregion information of a
1197 * specific byte. For example, say you want to know where the 4th ECC byte is
1198 * stored, you'll use:
1200 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1202 * Returns zero on success, a negative error code otherwise.
1204 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1205 int *sectionp, struct mtd_oob_region *oobregion,
1206 int (*iter)(struct mtd_info *,
1208 struct mtd_oob_region *oobregion))
1210 int pos = 0, ret, section = 0;
1212 memset(oobregion, 0, sizeof(*oobregion));
1215 ret = iter(mtd, section, oobregion);
1219 if (pos + oobregion->length > byte)
1222 pos += oobregion->length;
1227 * Adjust region info to make it start at the beginning at the
1230 oobregion->offset += byte - pos;
1231 oobregion->length -= byte - pos;
1232 *sectionp = section;
1238 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1240 * @mtd: mtd info structure
1241 * @eccbyte: the byte we are searching for
1242 * @sectionp: pointer where the section id will be stored
1243 * @oobregion: OOB region information
1245 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1248 * Returns zero on success, a negative error code otherwise.
1250 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1252 struct mtd_oob_region *oobregion)
1254 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1257 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1260 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1261 * @mtd: mtd info structure
1262 * @buf: destination buffer to store OOB bytes
1263 * @oobbuf: OOB buffer
1264 * @start: first byte to retrieve
1265 * @nbytes: number of bytes to retrieve
1266 * @iter: section iterator
1268 * Extract bytes attached to a specific category (ECC or free)
1269 * from the OOB buffer and copy them into buf.
1271 * Returns zero on success, a negative error code otherwise.
1273 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1274 const u8 *oobbuf, int start, int nbytes,
1275 int (*iter)(struct mtd_info *,
1277 struct mtd_oob_region *oobregion))
1279 struct mtd_oob_region oobregion = { };
1280 int section = 0, ret;
1282 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1288 cnt = oobregion.length > nbytes ? nbytes : oobregion.length;
1289 memcpy(buf, oobbuf + oobregion.offset, cnt);
1296 ret = iter(mtd, ++section, &oobregion);
1303 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1304 * @mtd: mtd info structure
1305 * @buf: source buffer to get OOB bytes from
1306 * @oobbuf: OOB buffer
1307 * @start: first OOB byte to set
1308 * @nbytes: number of OOB bytes to set
1309 * @iter: section iterator
1311 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1312 * is selected by passing the appropriate iterator.
1314 * Returns zero on success, a negative error code otherwise.
1316 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1317 u8 *oobbuf, int start, int nbytes,
1318 int (*iter)(struct mtd_info *,
1320 struct mtd_oob_region *oobregion))
1322 struct mtd_oob_region oobregion = { };
1323 int section = 0, ret;
1325 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1331 cnt = oobregion.length > nbytes ? nbytes : oobregion.length;
1332 memcpy(oobbuf + oobregion.offset, buf, cnt);
1339 ret = iter(mtd, ++section, &oobregion);
1346 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1347 * @mtd: mtd info structure
1348 * @iter: category iterator
1350 * Count the number of bytes in a given category.
1352 * Returns a positive value on success, a negative error code otherwise.
1354 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1355 int (*iter)(struct mtd_info *,
1357 struct mtd_oob_region *oobregion))
1359 struct mtd_oob_region oobregion = { };
1360 int section = 0, ret, nbytes = 0;
1363 ret = iter(mtd, section++, &oobregion);
1370 nbytes += oobregion.length;
1377 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1378 * @mtd: mtd info structure
1379 * @eccbuf: destination buffer to store ECC bytes
1380 * @oobbuf: OOB buffer
1381 * @start: first ECC byte to retrieve
1382 * @nbytes: number of ECC bytes to retrieve
1384 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1386 * Returns zero on success, a negative error code otherwise.
1388 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1389 const u8 *oobbuf, int start, int nbytes)
1391 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1394 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1397 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1398 * @mtd: mtd info structure
1399 * @eccbuf: source buffer to get ECC bytes from
1400 * @oobbuf: OOB buffer
1401 * @start: first ECC byte to set
1402 * @nbytes: number of ECC bytes to set
1404 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1406 * Returns zero on success, a negative error code otherwise.
1408 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1409 u8 *oobbuf, int start, int nbytes)
1411 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1414 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1417 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1418 * @mtd: mtd info structure
1419 * @databuf: destination buffer to store ECC bytes
1420 * @oobbuf: OOB buffer
1421 * @start: first ECC byte to retrieve
1422 * @nbytes: number of ECC bytes to retrieve
1424 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1426 * Returns zero on success, a negative error code otherwise.
1428 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1429 const u8 *oobbuf, int start, int nbytes)
1431 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1432 mtd_ooblayout_free);
1434 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1437 * mtd_ooblayout_get_eccbytes - set data bytes into the oob buffer
1438 * @mtd: mtd info structure
1439 * @eccbuf: source buffer to get data bytes from
1440 * @oobbuf: OOB buffer
1441 * @start: first ECC byte to set
1442 * @nbytes: number of ECC bytes to set
1444 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1446 * Returns zero on success, a negative error code otherwise.
1448 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1449 u8 *oobbuf, int start, int nbytes)
1451 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1452 mtd_ooblayout_free);
1454 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1457 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1458 * @mtd: mtd info structure
1460 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1462 * Returns zero on success, a negative error code otherwise.
1464 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1466 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1468 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1471 * mtd_ooblayout_count_freebytes - count the number of ECC bytes in OOB
1472 * @mtd: mtd info structure
1474 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1476 * Returns zero on success, a negative error code otherwise.
1478 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1480 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1482 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1485 * Method to access the protection register area, present in some flash
1486 * devices. The user data is one time programmable but the factory data is read
1489 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1490 struct otp_info *buf)
1492 if (!mtd->_get_fact_prot_info)
1496 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1498 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1500 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1501 size_t *retlen, u_char *buf)
1504 if (!mtd->_read_fact_prot_reg)
1508 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1510 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1512 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1513 struct otp_info *buf)
1515 if (!mtd->_get_user_prot_info)
1519 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1521 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1523 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1524 size_t *retlen, u_char *buf)
1527 if (!mtd->_read_user_prot_reg)
1531 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1533 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1535 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1536 size_t *retlen, u_char *buf)
1541 if (!mtd->_write_user_prot_reg)
1545 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1550 * If no data could be written at all, we are out of memory and
1551 * must return -ENOSPC.
1553 return (*retlen) ? 0 : -ENOSPC;
1555 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1557 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1559 if (!mtd->_lock_user_prot_reg)
1563 return mtd->_lock_user_prot_reg(mtd, from, len);
1565 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1567 /* Chip-supported device locking */
1568 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1572 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1576 return mtd->_lock(mtd, ofs, len);
1578 EXPORT_SYMBOL_GPL(mtd_lock);
1580 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1584 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1588 return mtd->_unlock(mtd, ofs, len);
1590 EXPORT_SYMBOL_GPL(mtd_unlock);
1592 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1594 if (!mtd->_is_locked)
1596 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1600 return mtd->_is_locked(mtd, ofs, len);
1602 EXPORT_SYMBOL_GPL(mtd_is_locked);
1604 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1606 if (ofs < 0 || ofs >= mtd->size)
1608 if (!mtd->_block_isreserved)
1610 return mtd->_block_isreserved(mtd, ofs);
1612 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1614 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1616 if (ofs < 0 || ofs >= mtd->size)
1618 if (!mtd->_block_isbad)
1620 return mtd->_block_isbad(mtd, ofs);
1622 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1624 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1626 if (!mtd->_block_markbad)
1628 if (ofs < 0 || ofs >= mtd->size)
1630 if (!(mtd->flags & MTD_WRITEABLE))
1632 return mtd->_block_markbad(mtd, ofs);
1634 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1637 * default_mtd_writev - the default writev method
1638 * @mtd: mtd device description object pointer
1639 * @vecs: the vectors to write
1640 * @count: count of vectors in @vecs
1641 * @to: the MTD device offset to write to
1642 * @retlen: on exit contains the count of bytes written to the MTD device.
1644 * This function returns zero in case of success and a negative error code in
1647 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1648 unsigned long count, loff_t to, size_t *retlen)
1651 size_t totlen = 0, thislen;
1654 for (i = 0; i < count; i++) {
1655 if (!vecs[i].iov_len)
1657 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1660 if (ret || thislen != vecs[i].iov_len)
1662 to += vecs[i].iov_len;
1669 * mtd_writev - the vector-based MTD write method
1670 * @mtd: mtd device description object pointer
1671 * @vecs: the vectors to write
1672 * @count: count of vectors in @vecs
1673 * @to: the MTD device offset to write to
1674 * @retlen: on exit contains the count of bytes written to the MTD device.
1676 * This function returns zero in case of success and a negative error code in
1679 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1680 unsigned long count, loff_t to, size_t *retlen)
1683 if (!(mtd->flags & MTD_WRITEABLE))
1686 return default_mtd_writev(mtd, vecs, count, to, retlen);
1687 return mtd->_writev(mtd, vecs, count, to, retlen);
1689 EXPORT_SYMBOL_GPL(mtd_writev);
1692 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1693 * @mtd: mtd device description object pointer
1694 * @size: a pointer to the ideal or maximum size of the allocation, points
1695 * to the actual allocation size on success.
1697 * This routine attempts to allocate a contiguous kernel buffer up to
1698 * the specified size, backing off the size of the request exponentially
1699 * until the request succeeds or until the allocation size falls below
1700 * the system page size. This attempts to make sure it does not adversely
1701 * impact system performance, so when allocating more than one page, we
1702 * ask the memory allocator to avoid re-trying, swapping, writing back
1703 * or performing I/O.
1705 * Note, this function also makes sure that the allocated buffer is aligned to
1706 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1708 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1709 * to handle smaller (i.e. degraded) buffer allocations under low- or
1710 * fragmented-memory situations where such reduced allocations, from a
1711 * requested ideal, are allowed.
1713 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1715 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1717 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1718 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1721 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1723 while (*size > min_alloc) {
1724 kbuf = kmalloc(*size, flags);
1729 *size = ALIGN(*size, mtd->writesize);
1733 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1734 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1736 return kmalloc(*size, GFP_KERNEL);
1738 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1740 #ifdef CONFIG_PROC_FS
1742 /*====================================================================*/
1743 /* Support for /proc/mtd */
1745 static int mtd_proc_show(struct seq_file *m, void *v)
1747 struct mtd_info *mtd;
1749 seq_puts(m, "dev: size erasesize name\n");
1750 mutex_lock(&mtd_table_mutex);
1751 mtd_for_each_device(mtd) {
1752 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1753 mtd->index, (unsigned long long)mtd->size,
1754 mtd->erasesize, mtd->name);
1756 mutex_unlock(&mtd_table_mutex);
1760 static int mtd_proc_open(struct inode *inode, struct file *file)
1762 return single_open(file, mtd_proc_show, NULL);
1765 static const struct file_operations mtd_proc_ops = {
1766 .open = mtd_proc_open,
1768 .llseek = seq_lseek,
1769 .release = single_release,
1771 #endif /* CONFIG_PROC_FS */
1773 /*====================================================================*/
1776 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1780 ret = bdi_init(bdi);
1782 ret = bdi_register(bdi, NULL, "%s", name);
1790 static struct proc_dir_entry *proc_mtd;
1792 static int __init init_mtd(void)
1796 ret = class_register(&mtd_class);
1800 ret = mtd_bdi_init(&mtd_bdi, "mtd");
1804 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1806 ret = init_mtdchar();
1814 remove_proc_entry("mtd", NULL);
1816 class_unregister(&mtd_class);
1818 pr_err("Error registering mtd class or bdi: %d\n", ret);
1822 static void __exit cleanup_mtd(void)
1826 remove_proc_entry("mtd", NULL);
1827 class_unregister(&mtd_class);
1828 bdi_destroy(&mtd_bdi);
1829 idr_destroy(&mtd_idr);
1832 module_init(init_mtd);
1833 module_exit(cleanup_mtd);
1835 MODULE_LICENSE("GPL");
1836 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1837 MODULE_DESCRIPTION("Core MTD registration and access routines");