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>
43 #include <linux/debugfs.h>
45 #include <linux/mtd/mtd.h>
46 #include <linux/mtd/partitions.h>
50 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_oobavail_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->oobavail);
220 static DEVICE_ATTR(oobavail, S_IRUGO, mtd_oobavail_show, NULL);
222 static ssize_t mtd_numeraseregions_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
225 struct mtd_info *mtd = dev_get_drvdata(dev);
227 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
230 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
233 static ssize_t mtd_name_show(struct device *dev,
234 struct device_attribute *attr, char *buf)
236 struct mtd_info *mtd = dev_get_drvdata(dev);
238 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
241 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
243 static ssize_t mtd_ecc_strength_show(struct device *dev,
244 struct device_attribute *attr, char *buf)
246 struct mtd_info *mtd = dev_get_drvdata(dev);
248 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
250 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
252 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
253 struct device_attribute *attr,
256 struct mtd_info *mtd = dev_get_drvdata(dev);
258 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
261 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
262 struct device_attribute *attr,
263 const char *buf, size_t count)
265 struct mtd_info *mtd = dev_get_drvdata(dev);
266 unsigned int bitflip_threshold;
269 retval = kstrtouint(buf, 0, &bitflip_threshold);
273 mtd->bitflip_threshold = bitflip_threshold;
276 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
277 mtd_bitflip_threshold_show,
278 mtd_bitflip_threshold_store);
280 static ssize_t mtd_ecc_step_size_show(struct device *dev,
281 struct device_attribute *attr, char *buf)
283 struct mtd_info *mtd = dev_get_drvdata(dev);
285 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
288 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
290 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
291 struct device_attribute *attr, char *buf)
293 struct mtd_info *mtd = dev_get_drvdata(dev);
294 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
296 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
298 static DEVICE_ATTR(corrected_bits, S_IRUGO,
299 mtd_ecc_stats_corrected_show, NULL);
301 static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
302 struct device_attribute *attr, char *buf)
304 struct mtd_info *mtd = dev_get_drvdata(dev);
305 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
307 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
309 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
311 static ssize_t mtd_badblocks_show(struct device *dev,
312 struct device_attribute *attr, char *buf)
314 struct mtd_info *mtd = dev_get_drvdata(dev);
315 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
317 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
319 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
321 static ssize_t mtd_bbtblocks_show(struct device *dev,
322 struct device_attribute *attr, char *buf)
324 struct mtd_info *mtd = dev_get_drvdata(dev);
325 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
327 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
329 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
331 static struct attribute *mtd_attrs[] = {
333 &dev_attr_flags.attr,
335 &dev_attr_erasesize.attr,
336 &dev_attr_writesize.attr,
337 &dev_attr_subpagesize.attr,
338 &dev_attr_oobsize.attr,
339 &dev_attr_oobavail.attr,
340 &dev_attr_numeraseregions.attr,
342 &dev_attr_ecc_strength.attr,
343 &dev_attr_ecc_step_size.attr,
344 &dev_attr_corrected_bits.attr,
345 &dev_attr_ecc_failures.attr,
346 &dev_attr_bad_blocks.attr,
347 &dev_attr_bbt_blocks.attr,
348 &dev_attr_bitflip_threshold.attr,
351 ATTRIBUTE_GROUPS(mtd);
353 static const struct device_type mtd_devtype = {
355 .groups = mtd_groups,
356 .release = mtd_release,
360 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
364 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
365 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
367 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
370 return NOMMU_MAP_COPY;
373 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
376 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
379 struct mtd_info *mtd;
381 mtd = container_of(n, struct mtd_info, reboot_notifier);
388 * mtd_wunit_to_pairing_info - get pairing information of a wunit
389 * @mtd: pointer to new MTD device info structure
390 * @wunit: write unit we are interested in
391 * @info: returned pairing information
393 * Retrieve pairing information associated to the wunit.
394 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
395 * paired together, and where programming a page may influence the page it is
397 * The notion of page is replaced by the term wunit (write-unit) to stay
398 * consistent with the ->writesize field.
400 * The @wunit argument can be extracted from an absolute offset using
401 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
404 * From the pairing info the MTD user can find all the wunits paired with
405 * @wunit using the following loop:
407 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
409 * mtd_pairing_info_to_wunit(mtd, &info);
413 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
414 struct mtd_pairing_info *info)
416 int npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
418 if (wunit < 0 || wunit >= npairs)
421 if (mtd->pairing && mtd->pairing->get_info)
422 return mtd->pairing->get_info(mtd, wunit, info);
429 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
432 * mtd_pairing_info_to_wunit - get wunit from pairing information
433 * @mtd: pointer to new MTD device info structure
434 * @info: pairing information struct
436 * Returns a positive number representing the wunit associated to the info
437 * struct, or a negative error code.
439 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
440 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
443 * It can also be used to only program the first page of each pair (i.e.
444 * page attached to group 0), which allows one to use an MLC NAND in
445 * software-emulated SLC mode:
448 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
449 * for (info.pair = 0; info.pair < npairs; info.pair++) {
450 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
451 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
452 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
455 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
456 const struct mtd_pairing_info *info)
458 int ngroups = mtd_pairing_groups(mtd);
459 int npairs = mtd_wunit_per_eb(mtd) / ngroups;
461 if (!info || info->pair < 0 || info->pair >= npairs ||
462 info->group < 0 || info->group >= ngroups)
465 if (mtd->pairing && mtd->pairing->get_wunit)
466 return mtd->pairing->get_wunit(mtd, info);
470 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
473 * mtd_pairing_groups - get the number of pairing groups
474 * @mtd: pointer to new MTD device info structure
476 * Returns the number of pairing groups.
478 * This number is usually equal to the number of bits exposed by a single
479 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
480 * to iterate over all pages of a given pair.
482 int mtd_pairing_groups(struct mtd_info *mtd)
484 if (!mtd->pairing || !mtd->pairing->ngroups)
487 return mtd->pairing->ngroups;
489 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
491 static struct dentry *dfs_dir_mtd;
494 * add_mtd_device - register an MTD device
495 * @mtd: pointer to new MTD device info structure
497 * Add a device to the list of MTD devices present in the system, and
498 * notify each currently active MTD 'user' of its arrival. Returns
499 * zero on success or non-zero on failure.
502 int add_mtd_device(struct mtd_info *mtd)
504 struct mtd_notifier *not;
508 * May occur, for instance, on buggy drivers which call
509 * mtd_device_parse_register() multiple times on the same master MTD,
510 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
512 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
515 BUG_ON(mtd->writesize == 0);
517 if (WARN_ON((!mtd->erasesize || !mtd->_erase) &&
518 !(mtd->flags & MTD_NO_ERASE)))
521 mutex_lock(&mtd_table_mutex);
523 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
532 /* default value if not set by driver */
533 if (mtd->bitflip_threshold == 0)
534 mtd->bitflip_threshold = mtd->ecc_strength;
536 if (is_power_of_2(mtd->erasesize))
537 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
539 mtd->erasesize_shift = 0;
541 if (is_power_of_2(mtd->writesize))
542 mtd->writesize_shift = ffs(mtd->writesize) - 1;
544 mtd->writesize_shift = 0;
546 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
547 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
549 /* Some chips always power up locked. Unlock them now */
550 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
551 error = mtd_unlock(mtd, 0, mtd->size);
552 if (error && error != -EOPNOTSUPP)
554 "%s: unlock failed, writes may not work\n",
556 /* Ignore unlock failures? */
560 /* Caller should have set dev.parent to match the
561 * physical device, if appropriate.
563 mtd->dev.type = &mtd_devtype;
564 mtd->dev.class = &mtd_class;
565 mtd->dev.devt = MTD_DEVT(i);
566 dev_set_name(&mtd->dev, "mtd%d", i);
567 dev_set_drvdata(&mtd->dev, mtd);
568 of_node_get(mtd_get_of_node(mtd));
569 error = device_register(&mtd->dev);
573 if (!IS_ERR_OR_NULL(dfs_dir_mtd)) {
574 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(&mtd->dev), dfs_dir_mtd);
575 if (IS_ERR_OR_NULL(mtd->dbg.dfs_dir)) {
576 pr_debug("mtd device %s won't show data in debugfs\n",
577 dev_name(&mtd->dev));
581 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
584 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
585 /* No need to get a refcount on the module containing
586 the notifier, since we hold the mtd_table_mutex */
587 list_for_each_entry(not, &mtd_notifiers, list)
590 mutex_unlock(&mtd_table_mutex);
591 /* We _know_ we aren't being removed, because
592 our caller is still holding us here. So none
593 of this try_ nonsense, and no bitching about it
595 __module_get(THIS_MODULE);
599 of_node_put(mtd_get_of_node(mtd));
600 idr_remove(&mtd_idr, i);
602 mutex_unlock(&mtd_table_mutex);
607 * del_mtd_device - unregister an MTD device
608 * @mtd: pointer to MTD device info structure
610 * Remove a device from the list of MTD devices present in the system,
611 * and notify each currently active MTD 'user' of its departure.
612 * Returns zero on success or 1 on failure, which currently will happen
613 * if the requested device does not appear to be present in the list.
616 int del_mtd_device(struct mtd_info *mtd)
619 struct mtd_notifier *not;
621 mutex_lock(&mtd_table_mutex);
623 debugfs_remove_recursive(mtd->dbg.dfs_dir);
625 if (idr_find(&mtd_idr, mtd->index) != mtd) {
630 /* No need to get a refcount on the module containing
631 the notifier, since we hold the mtd_table_mutex */
632 list_for_each_entry(not, &mtd_notifiers, list)
636 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
637 mtd->index, mtd->name, mtd->usecount);
640 device_unregister(&mtd->dev);
642 idr_remove(&mtd_idr, mtd->index);
643 of_node_put(mtd_get_of_node(mtd));
645 module_put(THIS_MODULE);
650 mutex_unlock(&mtd_table_mutex);
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 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
688 * * Then It tries to probe partitions on MTD device @mtd using parsers
689 * specified in @types (if @types is %NULL, then the default list of parsers
690 * is used, see 'parse_mtd_partitions()' for more information). If none are
691 * found this functions tries to fallback to information specified in
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,
705 mtd_set_dev_defaults(mtd);
707 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
708 ret = add_mtd_device(mtd);
713 /* Prefer parsed partitions over driver-provided fallback */
714 ret = parse_mtd_partitions(mtd, types, parser_data);
715 if (ret == -EPROBE_DEFER)
721 ret = add_mtd_partitions(mtd, parts, nr_parts);
722 else if (!device_is_registered(&mtd->dev))
723 ret = add_mtd_device(mtd);
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 if (ret && device_is_registered(&mtd->dev))
751 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
754 * mtd_device_unregister - unregister an existing MTD device.
756 * @master: the MTD device to unregister. This will unregister both the master
757 * and any partitions if registered.
759 int mtd_device_unregister(struct mtd_info *master)
764 unregister_reboot_notifier(&master->reboot_notifier);
766 err = del_mtd_partitions(master);
770 if (!device_is_registered(&master->dev))
773 return del_mtd_device(master);
775 EXPORT_SYMBOL_GPL(mtd_device_unregister);
778 * register_mtd_user - register a 'user' of MTD devices.
779 * @new: pointer to notifier info structure
781 * Registers a pair of callbacks function to be called upon addition
782 * or removal of MTD devices. Causes the 'add' callback to be immediately
783 * invoked for each MTD device currently present in the system.
785 void register_mtd_user (struct mtd_notifier *new)
787 struct mtd_info *mtd;
789 mutex_lock(&mtd_table_mutex);
791 list_add(&new->list, &mtd_notifiers);
793 __module_get(THIS_MODULE);
795 mtd_for_each_device(mtd)
798 mutex_unlock(&mtd_table_mutex);
800 EXPORT_SYMBOL_GPL(register_mtd_user);
803 * unregister_mtd_user - unregister a 'user' of MTD devices.
804 * @old: pointer to notifier info structure
806 * Removes a callback function pair from the list of 'users' to be
807 * notified upon addition or removal of MTD devices. Causes the
808 * 'remove' callback to be immediately invoked for each MTD device
809 * currently present in the system.
811 int unregister_mtd_user (struct mtd_notifier *old)
813 struct mtd_info *mtd;
815 mutex_lock(&mtd_table_mutex);
817 module_put(THIS_MODULE);
819 mtd_for_each_device(mtd)
822 list_del(&old->list);
823 mutex_unlock(&mtd_table_mutex);
826 EXPORT_SYMBOL_GPL(unregister_mtd_user);
829 * get_mtd_device - obtain a validated handle for an MTD device
830 * @mtd: last known address of the required MTD device
831 * @num: internal device number of the required MTD device
833 * Given a number and NULL address, return the num'th entry in the device
834 * table, if any. Given an address and num == -1, search the device table
835 * for a device with that address and return if it's still present. Given
836 * both, return the num'th driver only if its address matches. Return
839 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
841 struct mtd_info *ret = NULL, *other;
844 mutex_lock(&mtd_table_mutex);
847 mtd_for_each_device(other) {
853 } else if (num >= 0) {
854 ret = idr_find(&mtd_idr, num);
855 if (mtd && mtd != ret)
864 err = __get_mtd_device(ret);
868 mutex_unlock(&mtd_table_mutex);
871 EXPORT_SYMBOL_GPL(get_mtd_device);
874 int __get_mtd_device(struct mtd_info *mtd)
878 if (!try_module_get(mtd->owner))
881 if (mtd->_get_device) {
882 err = mtd->_get_device(mtd);
885 module_put(mtd->owner);
892 EXPORT_SYMBOL_GPL(__get_mtd_device);
895 * get_mtd_device_nm - obtain a validated handle for an MTD device by
897 * @name: MTD device name to open
899 * This function returns MTD device description structure in case of
900 * success and an error code in case of failure.
902 struct mtd_info *get_mtd_device_nm(const char *name)
905 struct mtd_info *mtd = NULL, *other;
907 mutex_lock(&mtd_table_mutex);
909 mtd_for_each_device(other) {
910 if (!strcmp(name, other->name)) {
919 err = __get_mtd_device(mtd);
923 mutex_unlock(&mtd_table_mutex);
927 mutex_unlock(&mtd_table_mutex);
930 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
932 void put_mtd_device(struct mtd_info *mtd)
934 mutex_lock(&mtd_table_mutex);
935 __put_mtd_device(mtd);
936 mutex_unlock(&mtd_table_mutex);
939 EXPORT_SYMBOL_GPL(put_mtd_device);
941 void __put_mtd_device(struct mtd_info *mtd)
944 BUG_ON(mtd->usecount < 0);
946 if (mtd->_put_device)
947 mtd->_put_device(mtd);
949 module_put(mtd->owner);
951 EXPORT_SYMBOL_GPL(__put_mtd_device);
954 * Erase is an synchronous operation. Device drivers are epected to return a
955 * negative error code if the operation failed and update instr->fail_addr
956 * to point the portion that was not properly erased.
958 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
960 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
962 if (!mtd->erasesize || !mtd->_erase)
965 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
967 if (!(mtd->flags & MTD_WRITEABLE))
973 ledtrig_mtd_activity();
974 return mtd->_erase(mtd, instr);
976 EXPORT_SYMBOL_GPL(mtd_erase);
979 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
981 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
982 void **virt, resource_size_t *phys)
990 if (from < 0 || from >= mtd->size || len > mtd->size - from)
994 return mtd->_point(mtd, from, len, retlen, virt, phys);
996 EXPORT_SYMBOL_GPL(mtd_point);
998 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
999 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1003 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1007 return mtd->_unpoint(mtd, from, len);
1009 EXPORT_SYMBOL_GPL(mtd_unpoint);
1012 * Allow NOMMU mmap() to directly map the device (if not NULL)
1013 * - return the address to which the offset maps
1014 * - return -ENOSYS to indicate refusal to do the mapping
1016 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1017 unsigned long offset, unsigned long flags)
1023 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1026 if (retlen != len) {
1027 mtd_unpoint(mtd, offset, retlen);
1030 return (unsigned long)virt;
1032 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1034 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1039 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1044 ledtrig_mtd_activity();
1046 * In the absence of an error, drivers return a non-negative integer
1047 * representing the maximum number of bitflips that were corrected on
1048 * any one ecc region (if applicable; zero otherwise).
1051 ret_code = mtd->_read(mtd, from, len, retlen, buf);
1052 } else if (mtd->_read_oob) {
1053 struct mtd_oob_ops ops = {
1058 ret_code = mtd->_read_oob(mtd, from, &ops);
1059 *retlen = ops.retlen;
1064 if (unlikely(ret_code < 0))
1066 if (mtd->ecc_strength == 0)
1067 return 0; /* device lacks ecc */
1068 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1070 EXPORT_SYMBOL_GPL(mtd_read);
1072 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1076 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1078 if ((!mtd->_write && !mtd->_write_oob) ||
1079 !(mtd->flags & MTD_WRITEABLE))
1083 ledtrig_mtd_activity();
1086 struct mtd_oob_ops ops = {
1088 .datbuf = (u8 *)buf,
1092 ret = mtd->_write_oob(mtd, to, &ops);
1093 *retlen = ops.retlen;
1097 return mtd->_write(mtd, to, len, retlen, buf);
1099 EXPORT_SYMBOL_GPL(mtd_write);
1102 * In blackbox flight recorder like scenarios we want to make successful writes
1103 * in interrupt context. panic_write() is only intended to be called when its
1104 * known the kernel is about to panic and we need the write to succeed. Since
1105 * the kernel is not going to be running for much longer, this function can
1106 * break locks and delay to ensure the write succeeds (but not sleep).
1108 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1112 if (!mtd->_panic_write)
1114 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1116 if (!(mtd->flags & MTD_WRITEABLE))
1120 return mtd->_panic_write(mtd, to, len, retlen, buf);
1122 EXPORT_SYMBOL_GPL(mtd_panic_write);
1124 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1125 struct mtd_oob_ops *ops)
1128 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1129 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1138 if (offs < 0 || offs + ops->len > mtd->size)
1144 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1147 maxooblen = ((mtd_div_by_ws(mtd->size, mtd) -
1148 mtd_div_by_ws(offs, mtd)) *
1149 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1150 if (ops->ooblen > maxooblen)
1157 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1160 ops->retlen = ops->oobretlen = 0;
1162 ret_code = mtd_check_oob_ops(mtd, from, ops);
1166 ledtrig_mtd_activity();
1168 /* Check the validity of a potential fallback on mtd->_read */
1169 if (!mtd->_read_oob && (!mtd->_read || ops->oobbuf))
1173 ret_code = mtd->_read_oob(mtd, from, ops);
1175 ret_code = mtd->_read(mtd, from, ops->len, &ops->retlen,
1179 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1180 * similar to mtd->_read(), returning a non-negative integer
1181 * representing max bitflips. In other cases, mtd->_read_oob() may
1182 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1184 if (unlikely(ret_code < 0))
1186 if (mtd->ecc_strength == 0)
1187 return 0; /* device lacks ecc */
1188 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1190 EXPORT_SYMBOL_GPL(mtd_read_oob);
1192 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1193 struct mtd_oob_ops *ops)
1197 ops->retlen = ops->oobretlen = 0;
1199 if (!(mtd->flags & MTD_WRITEABLE))
1202 ret = mtd_check_oob_ops(mtd, to, ops);
1206 ledtrig_mtd_activity();
1208 /* Check the validity of a potential fallback on mtd->_write */
1209 if (!mtd->_write_oob && (!mtd->_write || ops->oobbuf))
1212 if (mtd->_write_oob)
1213 return mtd->_write_oob(mtd, to, ops);
1215 return mtd->_write(mtd, to, ops->len, &ops->retlen,
1218 EXPORT_SYMBOL_GPL(mtd_write_oob);
1221 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1222 * @mtd: MTD device structure
1223 * @section: ECC section. Depending on the layout you may have all the ECC
1224 * bytes stored in a single contiguous section, or one section
1225 * per ECC chunk (and sometime several sections for a single ECC
1227 * @oobecc: OOB region struct filled with the appropriate ECC position
1230 * This function returns ECC section information in the OOB area. If you want
1231 * to get all the ECC bytes information, then you should call
1232 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1234 * Returns zero on success, a negative error code otherwise.
1236 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1237 struct mtd_oob_region *oobecc)
1239 memset(oobecc, 0, sizeof(*oobecc));
1241 if (!mtd || section < 0)
1244 if (!mtd->ooblayout || !mtd->ooblayout->ecc)
1247 return mtd->ooblayout->ecc(mtd, section, oobecc);
1249 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1252 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1254 * @mtd: MTD device structure
1255 * @section: Free section you are interested in. Depending on the layout
1256 * you may have all the free bytes stored in a single contiguous
1257 * section, or one section per ECC chunk plus an extra section
1258 * for the remaining bytes (or other funky layout).
1259 * @oobfree: OOB region struct filled with the appropriate free position
1262 * This function returns free bytes position in the OOB area. If you want
1263 * to get all the free bytes information, then you should call
1264 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1266 * Returns zero on success, a negative error code otherwise.
1268 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1269 struct mtd_oob_region *oobfree)
1271 memset(oobfree, 0, sizeof(*oobfree));
1273 if (!mtd || section < 0)
1276 if (!mtd->ooblayout || !mtd->ooblayout->free)
1279 return mtd->ooblayout->free(mtd, section, oobfree);
1281 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1284 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1285 * @mtd: mtd info structure
1286 * @byte: the byte we are searching for
1287 * @sectionp: pointer where the section id will be stored
1288 * @oobregion: used to retrieve the ECC position
1289 * @iter: iterator function. Should be either mtd_ooblayout_free or
1290 * mtd_ooblayout_ecc depending on the region type you're searching for
1292 * This function returns the section id and oobregion information of a
1293 * specific byte. For example, say you want to know where the 4th ECC byte is
1294 * stored, you'll use:
1296 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1298 * Returns zero on success, a negative error code otherwise.
1300 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1301 int *sectionp, struct mtd_oob_region *oobregion,
1302 int (*iter)(struct mtd_info *,
1304 struct mtd_oob_region *oobregion))
1306 int pos = 0, ret, section = 0;
1308 memset(oobregion, 0, sizeof(*oobregion));
1311 ret = iter(mtd, section, oobregion);
1315 if (pos + oobregion->length > byte)
1318 pos += oobregion->length;
1323 * Adjust region info to make it start at the beginning at the
1326 oobregion->offset += byte - pos;
1327 oobregion->length -= byte - pos;
1328 *sectionp = section;
1334 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1336 * @mtd: mtd info structure
1337 * @eccbyte: the byte we are searching for
1338 * @sectionp: pointer where the section id will be stored
1339 * @oobregion: OOB region information
1341 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1344 * Returns zero on success, a negative error code otherwise.
1346 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1348 struct mtd_oob_region *oobregion)
1350 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1353 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1356 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1357 * @mtd: mtd info structure
1358 * @buf: destination buffer to store OOB bytes
1359 * @oobbuf: OOB buffer
1360 * @start: first byte to retrieve
1361 * @nbytes: number of bytes to retrieve
1362 * @iter: section iterator
1364 * Extract bytes attached to a specific category (ECC or free)
1365 * from the OOB buffer and copy them into buf.
1367 * Returns zero on success, a negative error code otherwise.
1369 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1370 const u8 *oobbuf, int start, int nbytes,
1371 int (*iter)(struct mtd_info *,
1373 struct mtd_oob_region *oobregion))
1375 struct mtd_oob_region oobregion;
1378 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1384 cnt = min_t(int, nbytes, oobregion.length);
1385 memcpy(buf, oobbuf + oobregion.offset, cnt);
1392 ret = iter(mtd, ++section, &oobregion);
1399 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1400 * @mtd: mtd info structure
1401 * @buf: source buffer to get OOB bytes from
1402 * @oobbuf: OOB buffer
1403 * @start: first OOB byte to set
1404 * @nbytes: number of OOB bytes to set
1405 * @iter: section iterator
1407 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1408 * is selected by passing the appropriate iterator.
1410 * Returns zero on success, a negative error code otherwise.
1412 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1413 u8 *oobbuf, int start, int nbytes,
1414 int (*iter)(struct mtd_info *,
1416 struct mtd_oob_region *oobregion))
1418 struct mtd_oob_region oobregion;
1421 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1427 cnt = min_t(int, nbytes, oobregion.length);
1428 memcpy(oobbuf + oobregion.offset, buf, cnt);
1435 ret = iter(mtd, ++section, &oobregion);
1442 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1443 * @mtd: mtd info structure
1444 * @iter: category iterator
1446 * Count the number of bytes in a given category.
1448 * Returns a positive value on success, a negative error code otherwise.
1450 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1451 int (*iter)(struct mtd_info *,
1453 struct mtd_oob_region *oobregion))
1455 struct mtd_oob_region oobregion;
1456 int section = 0, ret, nbytes = 0;
1459 ret = iter(mtd, section++, &oobregion);
1466 nbytes += oobregion.length;
1473 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1474 * @mtd: mtd info structure
1475 * @eccbuf: destination buffer to store ECC bytes
1476 * @oobbuf: OOB buffer
1477 * @start: first ECC byte to retrieve
1478 * @nbytes: number of ECC bytes to retrieve
1480 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1482 * Returns zero on success, a negative error code otherwise.
1484 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1485 const u8 *oobbuf, int start, int nbytes)
1487 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1490 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1493 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1494 * @mtd: mtd info structure
1495 * @eccbuf: source buffer to get ECC bytes from
1496 * @oobbuf: OOB buffer
1497 * @start: first ECC byte to set
1498 * @nbytes: number of ECC bytes to set
1500 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1502 * Returns zero on success, a negative error code otherwise.
1504 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1505 u8 *oobbuf, int start, int nbytes)
1507 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1510 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1513 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1514 * @mtd: mtd info structure
1515 * @databuf: destination buffer to store ECC bytes
1516 * @oobbuf: OOB buffer
1517 * @start: first ECC byte to retrieve
1518 * @nbytes: number of ECC bytes to retrieve
1520 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1522 * Returns zero on success, a negative error code otherwise.
1524 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1525 const u8 *oobbuf, int start, int nbytes)
1527 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1528 mtd_ooblayout_free);
1530 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1533 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1534 * @mtd: mtd info structure
1535 * @databuf: source buffer to get data bytes from
1536 * @oobbuf: OOB buffer
1537 * @start: first ECC byte to set
1538 * @nbytes: number of ECC bytes to set
1540 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1542 * Returns zero on success, a negative error code otherwise.
1544 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1545 u8 *oobbuf, int start, int nbytes)
1547 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1548 mtd_ooblayout_free);
1550 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1553 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1554 * @mtd: mtd info structure
1556 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1558 * Returns zero on success, a negative error code otherwise.
1560 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1562 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1564 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1567 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1568 * @mtd: mtd info structure
1570 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1572 * Returns zero on success, a negative error code otherwise.
1574 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1576 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1578 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1581 * Method to access the protection register area, present in some flash
1582 * devices. The user data is one time programmable but the factory data is read
1585 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1586 struct otp_info *buf)
1588 if (!mtd->_get_fact_prot_info)
1592 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1594 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1596 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1597 size_t *retlen, u_char *buf)
1600 if (!mtd->_read_fact_prot_reg)
1604 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1606 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1608 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1609 struct otp_info *buf)
1611 if (!mtd->_get_user_prot_info)
1615 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1617 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1619 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1620 size_t *retlen, u_char *buf)
1623 if (!mtd->_read_user_prot_reg)
1627 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1629 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1631 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1632 size_t *retlen, u_char *buf)
1637 if (!mtd->_write_user_prot_reg)
1641 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1646 * If no data could be written at all, we are out of memory and
1647 * must return -ENOSPC.
1649 return (*retlen) ? 0 : -ENOSPC;
1651 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1653 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1655 if (!mtd->_lock_user_prot_reg)
1659 return mtd->_lock_user_prot_reg(mtd, from, len);
1661 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1663 /* Chip-supported device locking */
1664 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1668 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1672 return mtd->_lock(mtd, ofs, len);
1674 EXPORT_SYMBOL_GPL(mtd_lock);
1676 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1680 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1684 return mtd->_unlock(mtd, ofs, len);
1686 EXPORT_SYMBOL_GPL(mtd_unlock);
1688 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1690 if (!mtd->_is_locked)
1692 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1696 return mtd->_is_locked(mtd, ofs, len);
1698 EXPORT_SYMBOL_GPL(mtd_is_locked);
1700 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1702 if (ofs < 0 || ofs >= mtd->size)
1704 if (!mtd->_block_isreserved)
1706 return mtd->_block_isreserved(mtd, ofs);
1708 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1710 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1712 if (ofs < 0 || ofs >= mtd->size)
1714 if (!mtd->_block_isbad)
1716 return mtd->_block_isbad(mtd, ofs);
1718 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1720 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1722 if (!mtd->_block_markbad)
1724 if (ofs < 0 || ofs >= mtd->size)
1726 if (!(mtd->flags & MTD_WRITEABLE))
1728 return mtd->_block_markbad(mtd, ofs);
1730 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1733 * default_mtd_writev - the default writev method
1734 * @mtd: mtd device description object pointer
1735 * @vecs: the vectors to write
1736 * @count: count of vectors in @vecs
1737 * @to: the MTD device offset to write to
1738 * @retlen: on exit contains the count of bytes written to the MTD device.
1740 * This function returns zero in case of success and a negative error code in
1743 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1744 unsigned long count, loff_t to, size_t *retlen)
1747 size_t totlen = 0, thislen;
1750 for (i = 0; i < count; i++) {
1751 if (!vecs[i].iov_len)
1753 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1756 if (ret || thislen != vecs[i].iov_len)
1758 to += vecs[i].iov_len;
1765 * mtd_writev - the vector-based MTD write method
1766 * @mtd: mtd device description object pointer
1767 * @vecs: the vectors to write
1768 * @count: count of vectors in @vecs
1769 * @to: the MTD device offset to write to
1770 * @retlen: on exit contains the count of bytes written to the MTD device.
1772 * This function returns zero in case of success and a negative error code in
1775 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1776 unsigned long count, loff_t to, size_t *retlen)
1779 if (!(mtd->flags & MTD_WRITEABLE))
1782 return default_mtd_writev(mtd, vecs, count, to, retlen);
1783 return mtd->_writev(mtd, vecs, count, to, retlen);
1785 EXPORT_SYMBOL_GPL(mtd_writev);
1788 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1789 * @mtd: mtd device description object pointer
1790 * @size: a pointer to the ideal or maximum size of the allocation, points
1791 * to the actual allocation size on success.
1793 * This routine attempts to allocate a contiguous kernel buffer up to
1794 * the specified size, backing off the size of the request exponentially
1795 * until the request succeeds or until the allocation size falls below
1796 * the system page size. This attempts to make sure it does not adversely
1797 * impact system performance, so when allocating more than one page, we
1798 * ask the memory allocator to avoid re-trying, swapping, writing back
1799 * or performing I/O.
1801 * Note, this function also makes sure that the allocated buffer is aligned to
1802 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1804 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1805 * to handle smaller (i.e. degraded) buffer allocations under low- or
1806 * fragmented-memory situations where such reduced allocations, from a
1807 * requested ideal, are allowed.
1809 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1811 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1813 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1814 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1817 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1819 while (*size > min_alloc) {
1820 kbuf = kmalloc(*size, flags);
1825 *size = ALIGN(*size, mtd->writesize);
1829 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1830 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1832 return kmalloc(*size, GFP_KERNEL);
1834 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1836 #ifdef CONFIG_PROC_FS
1838 /*====================================================================*/
1839 /* Support for /proc/mtd */
1841 static int mtd_proc_show(struct seq_file *m, void *v)
1843 struct mtd_info *mtd;
1845 seq_puts(m, "dev: size erasesize name\n");
1846 mutex_lock(&mtd_table_mutex);
1847 mtd_for_each_device(mtd) {
1848 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1849 mtd->index, (unsigned long long)mtd->size,
1850 mtd->erasesize, mtd->name);
1852 mutex_unlock(&mtd_table_mutex);
1855 #endif /* CONFIG_PROC_FS */
1857 /*====================================================================*/
1860 static struct backing_dev_info * __init mtd_bdi_init(char *name)
1862 struct backing_dev_info *bdi;
1865 bdi = bdi_alloc(GFP_KERNEL);
1867 return ERR_PTR(-ENOMEM);
1871 * We put '-0' suffix to the name to get the same name format as we
1872 * used to get. Since this is called only once, we get a unique name.
1874 ret = bdi_register(bdi, "%.28s-0", name);
1878 return ret ? ERR_PTR(ret) : bdi;
1881 static struct proc_dir_entry *proc_mtd;
1883 static int __init init_mtd(void)
1887 ret = class_register(&mtd_class);
1891 mtd_bdi = mtd_bdi_init("mtd");
1892 if (IS_ERR(mtd_bdi)) {
1893 ret = PTR_ERR(mtd_bdi);
1897 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
1899 ret = init_mtdchar();
1903 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
1909 remove_proc_entry("mtd", NULL);
1912 class_unregister(&mtd_class);
1914 pr_err("Error registering mtd class or bdi: %d\n", ret);
1918 static void __exit cleanup_mtd(void)
1920 debugfs_remove_recursive(dfs_dir_mtd);
1923 remove_proc_entry("mtd", NULL);
1924 class_unregister(&mtd_class);
1926 idr_destroy(&mtd_idr);
1929 module_init(init_mtd);
1930 module_exit(cleanup_mtd);
1932 MODULE_LICENSE("GPL");
1933 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1934 MODULE_DESCRIPTION("Core MTD registration and access routines");