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);
571 put_device(&mtd->dev);
575 if (!IS_ERR_OR_NULL(dfs_dir_mtd)) {
576 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(&mtd->dev), dfs_dir_mtd);
577 if (IS_ERR_OR_NULL(mtd->dbg.dfs_dir)) {
578 pr_debug("mtd device %s won't show data in debugfs\n",
579 dev_name(&mtd->dev));
583 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
586 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
587 /* No need to get a refcount on the module containing
588 the notifier, since we hold the mtd_table_mutex */
589 list_for_each_entry(not, &mtd_notifiers, list)
592 mutex_unlock(&mtd_table_mutex);
593 /* We _know_ we aren't being removed, because
594 our caller is still holding us here. So none
595 of this try_ nonsense, and no bitching about it
597 __module_get(THIS_MODULE);
601 of_node_put(mtd_get_of_node(mtd));
602 idr_remove(&mtd_idr, i);
604 mutex_unlock(&mtd_table_mutex);
609 * del_mtd_device - unregister an MTD device
610 * @mtd: pointer to MTD device info structure
612 * Remove a device from the list of MTD devices present in the system,
613 * and notify each currently active MTD 'user' of its departure.
614 * Returns zero on success or 1 on failure, which currently will happen
615 * if the requested device does not appear to be present in the list.
618 int del_mtd_device(struct mtd_info *mtd)
621 struct mtd_notifier *not;
623 mutex_lock(&mtd_table_mutex);
625 debugfs_remove_recursive(mtd->dbg.dfs_dir);
627 if (idr_find(&mtd_idr, mtd->index) != mtd) {
632 /* No need to get a refcount on the module containing
633 the notifier, since we hold the mtd_table_mutex */
634 list_for_each_entry(not, &mtd_notifiers, list)
638 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
639 mtd->index, mtd->name, mtd->usecount);
642 device_unregister(&mtd->dev);
644 idr_remove(&mtd_idr, mtd->index);
645 of_node_put(mtd_get_of_node(mtd));
647 module_put(THIS_MODULE);
652 mutex_unlock(&mtd_table_mutex);
657 * Set a few defaults based on the parent devices, if not provided by the
660 static void mtd_set_dev_defaults(struct mtd_info *mtd)
662 if (mtd->dev.parent) {
663 if (!mtd->owner && mtd->dev.parent->driver)
664 mtd->owner = mtd->dev.parent->driver->owner;
666 mtd->name = dev_name(mtd->dev.parent);
668 pr_debug("mtd device won't show a device symlink in sysfs\n");
673 * mtd_device_parse_register - parse partitions and register an MTD device.
675 * @mtd: the MTD device to register
676 * @types: the list of MTD partition probes to try, see
677 * 'parse_mtd_partitions()' for more information
678 * @parser_data: MTD partition parser-specific data
679 * @parts: fallback partition information to register, if parsing fails;
680 * only valid if %nr_parts > %0
681 * @nr_parts: the number of partitions in parts, if zero then the full
682 * MTD device is registered if no partition info is found
684 * This function aggregates MTD partitions parsing (done by
685 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
686 * basically follows the most common pattern found in many MTD drivers:
688 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
690 * * Then It tries to probe partitions on MTD device @mtd using parsers
691 * specified in @types (if @types is %NULL, then the default list of parsers
692 * is used, see 'parse_mtd_partitions()' for more information). If none are
693 * found this functions tries to fallback to information specified in
695 * * If no partitions were found this function just registers the MTD device
698 * Returns zero in case of success and a negative error code in case of failure.
700 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
701 struct mtd_part_parser_data *parser_data,
702 const struct mtd_partition *parts,
707 mtd_set_dev_defaults(mtd);
709 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
710 ret = add_mtd_device(mtd);
715 /* Prefer parsed partitions over driver-provided fallback */
716 ret = parse_mtd_partitions(mtd, types, parser_data);
717 if (ret == -EPROBE_DEFER)
723 ret = add_mtd_partitions(mtd, parts, nr_parts);
724 else if (!device_is_registered(&mtd->dev))
725 ret = add_mtd_device(mtd);
733 * FIXME: some drivers unfortunately call this function more than once.
734 * So we have to check if we've already assigned the reboot notifier.
736 * Generally, we can make multiple calls work for most cases, but it
737 * does cause problems with parse_mtd_partitions() above (e.g.,
738 * cmdlineparts will register partitions more than once).
740 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
741 "MTD already registered\n");
742 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
743 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
744 register_reboot_notifier(&mtd->reboot_notifier);
748 if (ret && device_is_registered(&mtd->dev))
753 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
756 * mtd_device_unregister - unregister an existing MTD device.
758 * @master: the MTD device to unregister. This will unregister both the master
759 * and any partitions if registered.
761 int mtd_device_unregister(struct mtd_info *master)
766 unregister_reboot_notifier(&master->reboot_notifier);
768 err = del_mtd_partitions(master);
772 if (!device_is_registered(&master->dev))
775 return del_mtd_device(master);
777 EXPORT_SYMBOL_GPL(mtd_device_unregister);
780 * register_mtd_user - register a 'user' of MTD devices.
781 * @new: pointer to notifier info structure
783 * Registers a pair of callbacks function to be called upon addition
784 * or removal of MTD devices. Causes the 'add' callback to be immediately
785 * invoked for each MTD device currently present in the system.
787 void register_mtd_user (struct mtd_notifier *new)
789 struct mtd_info *mtd;
791 mutex_lock(&mtd_table_mutex);
793 list_add(&new->list, &mtd_notifiers);
795 __module_get(THIS_MODULE);
797 mtd_for_each_device(mtd)
800 mutex_unlock(&mtd_table_mutex);
802 EXPORT_SYMBOL_GPL(register_mtd_user);
805 * unregister_mtd_user - unregister a 'user' of MTD devices.
806 * @old: pointer to notifier info structure
808 * Removes a callback function pair from the list of 'users' to be
809 * notified upon addition or removal of MTD devices. Causes the
810 * 'remove' callback to be immediately invoked for each MTD device
811 * currently present in the system.
813 int unregister_mtd_user (struct mtd_notifier *old)
815 struct mtd_info *mtd;
817 mutex_lock(&mtd_table_mutex);
819 module_put(THIS_MODULE);
821 mtd_for_each_device(mtd)
824 list_del(&old->list);
825 mutex_unlock(&mtd_table_mutex);
828 EXPORT_SYMBOL_GPL(unregister_mtd_user);
831 * get_mtd_device - obtain a validated handle for an MTD device
832 * @mtd: last known address of the required MTD device
833 * @num: internal device number of the required MTD device
835 * Given a number and NULL address, return the num'th entry in the device
836 * table, if any. Given an address and num == -1, search the device table
837 * for a device with that address and return if it's still present. Given
838 * both, return the num'th driver only if its address matches. Return
841 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
843 struct mtd_info *ret = NULL, *other;
846 mutex_lock(&mtd_table_mutex);
849 mtd_for_each_device(other) {
855 } else if (num >= 0) {
856 ret = idr_find(&mtd_idr, num);
857 if (mtd && mtd != ret)
866 err = __get_mtd_device(ret);
870 mutex_unlock(&mtd_table_mutex);
873 EXPORT_SYMBOL_GPL(get_mtd_device);
876 int __get_mtd_device(struct mtd_info *mtd)
880 if (!try_module_get(mtd->owner))
883 if (mtd->_get_device) {
884 err = mtd->_get_device(mtd);
887 module_put(mtd->owner);
894 EXPORT_SYMBOL_GPL(__get_mtd_device);
897 * get_mtd_device_nm - obtain a validated handle for an MTD device by
899 * @name: MTD device name to open
901 * This function returns MTD device description structure in case of
902 * success and an error code in case of failure.
904 struct mtd_info *get_mtd_device_nm(const char *name)
907 struct mtd_info *mtd = NULL, *other;
909 mutex_lock(&mtd_table_mutex);
911 mtd_for_each_device(other) {
912 if (!strcmp(name, other->name)) {
921 err = __get_mtd_device(mtd);
925 mutex_unlock(&mtd_table_mutex);
929 mutex_unlock(&mtd_table_mutex);
932 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
934 void put_mtd_device(struct mtd_info *mtd)
936 mutex_lock(&mtd_table_mutex);
937 __put_mtd_device(mtd);
938 mutex_unlock(&mtd_table_mutex);
941 EXPORT_SYMBOL_GPL(put_mtd_device);
943 void __put_mtd_device(struct mtd_info *mtd)
946 BUG_ON(mtd->usecount < 0);
948 if (mtd->_put_device)
949 mtd->_put_device(mtd);
951 module_put(mtd->owner);
953 EXPORT_SYMBOL_GPL(__put_mtd_device);
956 * Erase is an synchronous operation. Device drivers are epected to return a
957 * negative error code if the operation failed and update instr->fail_addr
958 * to point the portion that was not properly erased.
960 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
962 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
964 if (!mtd->erasesize || !mtd->_erase)
967 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
969 if (!(mtd->flags & MTD_WRITEABLE))
975 ledtrig_mtd_activity();
976 return mtd->_erase(mtd, instr);
978 EXPORT_SYMBOL_GPL(mtd_erase);
981 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
983 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
984 void **virt, resource_size_t *phys)
992 if (from < 0 || from >= mtd->size || len > mtd->size - from)
996 return mtd->_point(mtd, from, len, retlen, virt, phys);
998 EXPORT_SYMBOL_GPL(mtd_point);
1000 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1001 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1005 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1009 return mtd->_unpoint(mtd, from, len);
1011 EXPORT_SYMBOL_GPL(mtd_unpoint);
1014 * Allow NOMMU mmap() to directly map the device (if not NULL)
1015 * - return the address to which the offset maps
1016 * - return -ENOSYS to indicate refusal to do the mapping
1018 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1019 unsigned long offset, unsigned long flags)
1025 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1028 if (retlen != len) {
1029 mtd_unpoint(mtd, offset, retlen);
1032 return (unsigned long)virt;
1034 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1036 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1041 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1046 ledtrig_mtd_activity();
1048 * In the absence of an error, drivers return a non-negative integer
1049 * representing the maximum number of bitflips that were corrected on
1050 * any one ecc region (if applicable; zero otherwise).
1053 ret_code = mtd->_read(mtd, from, len, retlen, buf);
1054 } else if (mtd->_read_oob) {
1055 struct mtd_oob_ops ops = {
1060 ret_code = mtd->_read_oob(mtd, from, &ops);
1061 *retlen = ops.retlen;
1066 if (unlikely(ret_code < 0))
1068 if (mtd->ecc_strength == 0)
1069 return 0; /* device lacks ecc */
1070 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1072 EXPORT_SYMBOL_GPL(mtd_read);
1074 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1078 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1080 if ((!mtd->_write && !mtd->_write_oob) ||
1081 !(mtd->flags & MTD_WRITEABLE))
1085 ledtrig_mtd_activity();
1088 struct mtd_oob_ops ops = {
1090 .datbuf = (u8 *)buf,
1094 ret = mtd->_write_oob(mtd, to, &ops);
1095 *retlen = ops.retlen;
1099 return mtd->_write(mtd, to, len, retlen, buf);
1101 EXPORT_SYMBOL_GPL(mtd_write);
1104 * In blackbox flight recorder like scenarios we want to make successful writes
1105 * in interrupt context. panic_write() is only intended to be called when its
1106 * known the kernel is about to panic and we need the write to succeed. Since
1107 * the kernel is not going to be running for much longer, this function can
1108 * break locks and delay to ensure the write succeeds (but not sleep).
1110 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1114 if (!mtd->_panic_write)
1116 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1118 if (!(mtd->flags & MTD_WRITEABLE))
1122 return mtd->_panic_write(mtd, to, len, retlen, buf);
1124 EXPORT_SYMBOL_GPL(mtd_panic_write);
1126 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1127 struct mtd_oob_ops *ops)
1130 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1131 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1140 if (offs < 0 || offs + ops->len > mtd->size)
1146 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1149 maxooblen = ((mtd_div_by_ws(mtd->size, mtd) -
1150 mtd_div_by_ws(offs, mtd)) *
1151 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1152 if (ops->ooblen > maxooblen)
1159 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1162 ops->retlen = ops->oobretlen = 0;
1164 ret_code = mtd_check_oob_ops(mtd, from, ops);
1168 ledtrig_mtd_activity();
1170 /* Check the validity of a potential fallback on mtd->_read */
1171 if (!mtd->_read_oob && (!mtd->_read || ops->oobbuf))
1175 ret_code = mtd->_read_oob(mtd, from, ops);
1177 ret_code = mtd->_read(mtd, from, ops->len, &ops->retlen,
1181 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1182 * similar to mtd->_read(), returning a non-negative integer
1183 * representing max bitflips. In other cases, mtd->_read_oob() may
1184 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1186 if (unlikely(ret_code < 0))
1188 if (mtd->ecc_strength == 0)
1189 return 0; /* device lacks ecc */
1190 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1192 EXPORT_SYMBOL_GPL(mtd_read_oob);
1194 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1195 struct mtd_oob_ops *ops)
1199 ops->retlen = ops->oobretlen = 0;
1201 if (!(mtd->flags & MTD_WRITEABLE))
1204 ret = mtd_check_oob_ops(mtd, to, ops);
1208 ledtrig_mtd_activity();
1210 /* Check the validity of a potential fallback on mtd->_write */
1211 if (!mtd->_write_oob && (!mtd->_write || ops->oobbuf))
1214 if (mtd->_write_oob)
1215 return mtd->_write_oob(mtd, to, ops);
1217 return mtd->_write(mtd, to, ops->len, &ops->retlen,
1220 EXPORT_SYMBOL_GPL(mtd_write_oob);
1223 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1224 * @mtd: MTD device structure
1225 * @section: ECC section. Depending on the layout you may have all the ECC
1226 * bytes stored in a single contiguous section, or one section
1227 * per ECC chunk (and sometime several sections for a single ECC
1229 * @oobecc: OOB region struct filled with the appropriate ECC position
1232 * This function returns ECC section information in the OOB area. If you want
1233 * to get all the ECC bytes information, then you should call
1234 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1236 * Returns zero on success, a negative error code otherwise.
1238 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1239 struct mtd_oob_region *oobecc)
1241 memset(oobecc, 0, sizeof(*oobecc));
1243 if (!mtd || section < 0)
1246 if (!mtd->ooblayout || !mtd->ooblayout->ecc)
1249 return mtd->ooblayout->ecc(mtd, section, oobecc);
1251 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1254 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1256 * @mtd: MTD device structure
1257 * @section: Free section you are interested in. Depending on the layout
1258 * you may have all the free bytes stored in a single contiguous
1259 * section, or one section per ECC chunk plus an extra section
1260 * for the remaining bytes (or other funky layout).
1261 * @oobfree: OOB region struct filled with the appropriate free position
1264 * This function returns free bytes position in the OOB area. If you want
1265 * to get all the free bytes information, then you should call
1266 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1268 * Returns zero on success, a negative error code otherwise.
1270 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1271 struct mtd_oob_region *oobfree)
1273 memset(oobfree, 0, sizeof(*oobfree));
1275 if (!mtd || section < 0)
1278 if (!mtd->ooblayout || !mtd->ooblayout->free)
1281 return mtd->ooblayout->free(mtd, section, oobfree);
1283 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1286 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1287 * @mtd: mtd info structure
1288 * @byte: the byte we are searching for
1289 * @sectionp: pointer where the section id will be stored
1290 * @oobregion: used to retrieve the ECC position
1291 * @iter: iterator function. Should be either mtd_ooblayout_free or
1292 * mtd_ooblayout_ecc depending on the region type you're searching for
1294 * This function returns the section id and oobregion information of a
1295 * specific byte. For example, say you want to know where the 4th ECC byte is
1296 * stored, you'll use:
1298 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1300 * Returns zero on success, a negative error code otherwise.
1302 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1303 int *sectionp, struct mtd_oob_region *oobregion,
1304 int (*iter)(struct mtd_info *,
1306 struct mtd_oob_region *oobregion))
1308 int pos = 0, ret, section = 0;
1310 memset(oobregion, 0, sizeof(*oobregion));
1313 ret = iter(mtd, section, oobregion);
1317 if (pos + oobregion->length > byte)
1320 pos += oobregion->length;
1325 * Adjust region info to make it start at the beginning at the
1328 oobregion->offset += byte - pos;
1329 oobregion->length -= byte - pos;
1330 *sectionp = section;
1336 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1338 * @mtd: mtd info structure
1339 * @eccbyte: the byte we are searching for
1340 * @sectionp: pointer where the section id will be stored
1341 * @oobregion: OOB region information
1343 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1346 * Returns zero on success, a negative error code otherwise.
1348 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1350 struct mtd_oob_region *oobregion)
1352 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1355 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1358 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1359 * @mtd: mtd info structure
1360 * @buf: destination buffer to store OOB bytes
1361 * @oobbuf: OOB buffer
1362 * @start: first byte to retrieve
1363 * @nbytes: number of bytes to retrieve
1364 * @iter: section iterator
1366 * Extract bytes attached to a specific category (ECC or free)
1367 * from the OOB buffer and copy them into buf.
1369 * Returns zero on success, a negative error code otherwise.
1371 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1372 const u8 *oobbuf, int start, int nbytes,
1373 int (*iter)(struct mtd_info *,
1375 struct mtd_oob_region *oobregion))
1377 struct mtd_oob_region oobregion;
1380 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1386 cnt = min_t(int, nbytes, oobregion.length);
1387 memcpy(buf, oobbuf + oobregion.offset, cnt);
1394 ret = iter(mtd, ++section, &oobregion);
1401 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1402 * @mtd: mtd info structure
1403 * @buf: source buffer to get OOB bytes from
1404 * @oobbuf: OOB buffer
1405 * @start: first OOB byte to set
1406 * @nbytes: number of OOB bytes to set
1407 * @iter: section iterator
1409 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1410 * is selected by passing the appropriate iterator.
1412 * Returns zero on success, a negative error code otherwise.
1414 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1415 u8 *oobbuf, int start, int nbytes,
1416 int (*iter)(struct mtd_info *,
1418 struct mtd_oob_region *oobregion))
1420 struct mtd_oob_region oobregion;
1423 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1429 cnt = min_t(int, nbytes, oobregion.length);
1430 memcpy(oobbuf + oobregion.offset, buf, cnt);
1437 ret = iter(mtd, ++section, &oobregion);
1444 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1445 * @mtd: mtd info structure
1446 * @iter: category iterator
1448 * Count the number of bytes in a given category.
1450 * Returns a positive value on success, a negative error code otherwise.
1452 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1453 int (*iter)(struct mtd_info *,
1455 struct mtd_oob_region *oobregion))
1457 struct mtd_oob_region oobregion;
1458 int section = 0, ret, nbytes = 0;
1461 ret = iter(mtd, section++, &oobregion);
1468 nbytes += oobregion.length;
1475 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1476 * @mtd: mtd info structure
1477 * @eccbuf: destination buffer to store ECC bytes
1478 * @oobbuf: OOB buffer
1479 * @start: first ECC byte to retrieve
1480 * @nbytes: number of ECC bytes to retrieve
1482 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1484 * Returns zero on success, a negative error code otherwise.
1486 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1487 const u8 *oobbuf, int start, int nbytes)
1489 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1492 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1495 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1496 * @mtd: mtd info structure
1497 * @eccbuf: source buffer to get ECC bytes from
1498 * @oobbuf: OOB buffer
1499 * @start: first ECC byte to set
1500 * @nbytes: number of ECC bytes to set
1502 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1504 * Returns zero on success, a negative error code otherwise.
1506 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1507 u8 *oobbuf, int start, int nbytes)
1509 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1512 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1515 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1516 * @mtd: mtd info structure
1517 * @databuf: destination buffer to store ECC bytes
1518 * @oobbuf: OOB buffer
1519 * @start: first ECC byte to retrieve
1520 * @nbytes: number of ECC bytes to retrieve
1522 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1524 * Returns zero on success, a negative error code otherwise.
1526 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1527 const u8 *oobbuf, int start, int nbytes)
1529 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1530 mtd_ooblayout_free);
1532 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1535 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1536 * @mtd: mtd info structure
1537 * @databuf: source buffer to get data bytes from
1538 * @oobbuf: OOB buffer
1539 * @start: first ECC byte to set
1540 * @nbytes: number of ECC bytes to set
1542 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1544 * Returns zero on success, a negative error code otherwise.
1546 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1547 u8 *oobbuf, int start, int nbytes)
1549 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1550 mtd_ooblayout_free);
1552 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1555 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1556 * @mtd: mtd info structure
1558 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1560 * Returns zero on success, a negative error code otherwise.
1562 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1564 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1566 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1569 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1570 * @mtd: mtd info structure
1572 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1574 * Returns zero on success, a negative error code otherwise.
1576 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1578 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1580 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1583 * Method to access the protection register area, present in some flash
1584 * devices. The user data is one time programmable but the factory data is read
1587 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1588 struct otp_info *buf)
1590 if (!mtd->_get_fact_prot_info)
1594 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1596 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1598 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1599 size_t *retlen, u_char *buf)
1602 if (!mtd->_read_fact_prot_reg)
1606 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1608 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1610 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1611 struct otp_info *buf)
1613 if (!mtd->_get_user_prot_info)
1617 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1619 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1621 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1622 size_t *retlen, u_char *buf)
1625 if (!mtd->_read_user_prot_reg)
1629 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1631 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1633 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1634 size_t *retlen, u_char *buf)
1639 if (!mtd->_write_user_prot_reg)
1643 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1648 * If no data could be written at all, we are out of memory and
1649 * must return -ENOSPC.
1651 return (*retlen) ? 0 : -ENOSPC;
1653 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1655 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1657 if (!mtd->_lock_user_prot_reg)
1661 return mtd->_lock_user_prot_reg(mtd, from, len);
1663 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1665 /* Chip-supported device locking */
1666 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1670 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1674 return mtd->_lock(mtd, ofs, len);
1676 EXPORT_SYMBOL_GPL(mtd_lock);
1678 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1682 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1686 return mtd->_unlock(mtd, ofs, len);
1688 EXPORT_SYMBOL_GPL(mtd_unlock);
1690 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1692 if (!mtd->_is_locked)
1694 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1698 return mtd->_is_locked(mtd, ofs, len);
1700 EXPORT_SYMBOL_GPL(mtd_is_locked);
1702 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1704 if (ofs < 0 || ofs >= mtd->size)
1706 if (!mtd->_block_isreserved)
1708 return mtd->_block_isreserved(mtd, ofs);
1710 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1712 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1714 if (ofs < 0 || ofs >= mtd->size)
1716 if (!mtd->_block_isbad)
1718 return mtd->_block_isbad(mtd, ofs);
1720 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1722 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1724 if (!mtd->_block_markbad)
1726 if (ofs < 0 || ofs >= mtd->size)
1728 if (!(mtd->flags & MTD_WRITEABLE))
1730 return mtd->_block_markbad(mtd, ofs);
1732 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1735 * default_mtd_writev - the default writev method
1736 * @mtd: mtd device description object pointer
1737 * @vecs: the vectors to write
1738 * @count: count of vectors in @vecs
1739 * @to: the MTD device offset to write to
1740 * @retlen: on exit contains the count of bytes written to the MTD device.
1742 * This function returns zero in case of success and a negative error code in
1745 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1746 unsigned long count, loff_t to, size_t *retlen)
1749 size_t totlen = 0, thislen;
1752 for (i = 0; i < count; i++) {
1753 if (!vecs[i].iov_len)
1755 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1758 if (ret || thislen != vecs[i].iov_len)
1760 to += vecs[i].iov_len;
1767 * mtd_writev - the vector-based MTD write method
1768 * @mtd: mtd device description object pointer
1769 * @vecs: the vectors to write
1770 * @count: count of vectors in @vecs
1771 * @to: the MTD device offset to write to
1772 * @retlen: on exit contains the count of bytes written to the MTD device.
1774 * This function returns zero in case of success and a negative error code in
1777 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1778 unsigned long count, loff_t to, size_t *retlen)
1781 if (!(mtd->flags & MTD_WRITEABLE))
1784 return default_mtd_writev(mtd, vecs, count, to, retlen);
1785 return mtd->_writev(mtd, vecs, count, to, retlen);
1787 EXPORT_SYMBOL_GPL(mtd_writev);
1790 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1791 * @mtd: mtd device description object pointer
1792 * @size: a pointer to the ideal or maximum size of the allocation, points
1793 * to the actual allocation size on success.
1795 * This routine attempts to allocate a contiguous kernel buffer up to
1796 * the specified size, backing off the size of the request exponentially
1797 * until the request succeeds or until the allocation size falls below
1798 * the system page size. This attempts to make sure it does not adversely
1799 * impact system performance, so when allocating more than one page, we
1800 * ask the memory allocator to avoid re-trying, swapping, writing back
1801 * or performing I/O.
1803 * Note, this function also makes sure that the allocated buffer is aligned to
1804 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1806 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1807 * to handle smaller (i.e. degraded) buffer allocations under low- or
1808 * fragmented-memory situations where such reduced allocations, from a
1809 * requested ideal, are allowed.
1811 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1813 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1815 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1816 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1819 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1821 while (*size > min_alloc) {
1822 kbuf = kmalloc(*size, flags);
1827 *size = ALIGN(*size, mtd->writesize);
1831 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1832 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1834 return kmalloc(*size, GFP_KERNEL);
1836 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1838 #ifdef CONFIG_PROC_FS
1840 /*====================================================================*/
1841 /* Support for /proc/mtd */
1843 static int mtd_proc_show(struct seq_file *m, void *v)
1845 struct mtd_info *mtd;
1847 seq_puts(m, "dev: size erasesize name\n");
1848 mutex_lock(&mtd_table_mutex);
1849 mtd_for_each_device(mtd) {
1850 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1851 mtd->index, (unsigned long long)mtd->size,
1852 mtd->erasesize, mtd->name);
1854 mutex_unlock(&mtd_table_mutex);
1857 #endif /* CONFIG_PROC_FS */
1859 /*====================================================================*/
1862 static struct backing_dev_info * __init mtd_bdi_init(char *name)
1864 struct backing_dev_info *bdi;
1867 bdi = bdi_alloc(GFP_KERNEL);
1869 return ERR_PTR(-ENOMEM);
1873 * We put '-0' suffix to the name to get the same name format as we
1874 * used to get. Since this is called only once, we get a unique name.
1876 ret = bdi_register(bdi, "%.28s-0", name);
1880 return ret ? ERR_PTR(ret) : bdi;
1883 static struct proc_dir_entry *proc_mtd;
1885 static int __init init_mtd(void)
1889 ret = class_register(&mtd_class);
1893 mtd_bdi = mtd_bdi_init("mtd");
1894 if (IS_ERR(mtd_bdi)) {
1895 ret = PTR_ERR(mtd_bdi);
1899 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
1901 ret = init_mtdchar();
1905 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
1911 remove_proc_entry("mtd", NULL);
1914 class_unregister(&mtd_class);
1916 pr_err("Error registering mtd class or bdi: %d\n", ret);
1920 static void __exit cleanup_mtd(void)
1922 debugfs_remove_recursive(dfs_dir_mtd);
1925 remove_proc_entry("mtd", NULL);
1926 class_unregister(&mtd_class);
1928 idr_destroy(&mtd_idr);
1931 module_init(init_mtd);
1932 module_exit(cleanup_mtd);
1934 MODULE_LICENSE("GPL");
1935 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1936 MODULE_DESCRIPTION("Core MTD registration and access routines");