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_numeraseregions_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
216 struct mtd_info *mtd = dev_get_drvdata(dev);
218 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
221 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
224 static ssize_t mtd_name_show(struct device *dev,
225 struct device_attribute *attr, char *buf)
227 struct mtd_info *mtd = dev_get_drvdata(dev);
229 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
232 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
234 static ssize_t mtd_ecc_strength_show(struct device *dev,
235 struct device_attribute *attr, char *buf)
237 struct mtd_info *mtd = dev_get_drvdata(dev);
239 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
241 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
243 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
244 struct device_attribute *attr,
247 struct mtd_info *mtd = dev_get_drvdata(dev);
249 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
252 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
253 struct device_attribute *attr,
254 const char *buf, size_t count)
256 struct mtd_info *mtd = dev_get_drvdata(dev);
257 unsigned int bitflip_threshold;
260 retval = kstrtouint(buf, 0, &bitflip_threshold);
264 mtd->bitflip_threshold = bitflip_threshold;
267 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
268 mtd_bitflip_threshold_show,
269 mtd_bitflip_threshold_store);
271 static ssize_t mtd_ecc_step_size_show(struct device *dev,
272 struct device_attribute *attr, char *buf)
274 struct mtd_info *mtd = dev_get_drvdata(dev);
276 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
279 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
281 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
282 struct device_attribute *attr, char *buf)
284 struct mtd_info *mtd = dev_get_drvdata(dev);
285 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
287 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
289 static DEVICE_ATTR(corrected_bits, S_IRUGO,
290 mtd_ecc_stats_corrected_show, NULL);
292 static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
293 struct device_attribute *attr, char *buf)
295 struct mtd_info *mtd = dev_get_drvdata(dev);
296 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
298 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
300 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
302 static ssize_t mtd_badblocks_show(struct device *dev,
303 struct device_attribute *attr, char *buf)
305 struct mtd_info *mtd = dev_get_drvdata(dev);
306 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
308 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
310 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
312 static ssize_t mtd_bbtblocks_show(struct device *dev,
313 struct device_attribute *attr, char *buf)
315 struct mtd_info *mtd = dev_get_drvdata(dev);
316 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
318 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
320 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
322 static struct attribute *mtd_attrs[] = {
324 &dev_attr_flags.attr,
326 &dev_attr_erasesize.attr,
327 &dev_attr_writesize.attr,
328 &dev_attr_subpagesize.attr,
329 &dev_attr_oobsize.attr,
330 &dev_attr_numeraseregions.attr,
332 &dev_attr_ecc_strength.attr,
333 &dev_attr_ecc_step_size.attr,
334 &dev_attr_corrected_bits.attr,
335 &dev_attr_ecc_failures.attr,
336 &dev_attr_bad_blocks.attr,
337 &dev_attr_bbt_blocks.attr,
338 &dev_attr_bitflip_threshold.attr,
341 ATTRIBUTE_GROUPS(mtd);
343 static const struct device_type mtd_devtype = {
345 .groups = mtd_groups,
346 .release = mtd_release,
350 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
354 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
355 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
357 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
360 return NOMMU_MAP_COPY;
363 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
366 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
369 struct mtd_info *mtd;
371 mtd = container_of(n, struct mtd_info, reboot_notifier);
378 * mtd_wunit_to_pairing_info - get pairing information of a wunit
379 * @mtd: pointer to new MTD device info structure
380 * @wunit: write unit we are interested in
381 * @info: returned pairing information
383 * Retrieve pairing information associated to the wunit.
384 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
385 * paired together, and where programming a page may influence the page it is
387 * The notion of page is replaced by the term wunit (write-unit) to stay
388 * consistent with the ->writesize field.
390 * The @wunit argument can be extracted from an absolute offset using
391 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
394 * From the pairing info the MTD user can find all the wunits paired with
395 * @wunit using the following loop:
397 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
399 * mtd_pairing_info_to_wunit(mtd, &info);
403 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
404 struct mtd_pairing_info *info)
406 int npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
408 if (wunit < 0 || wunit >= npairs)
411 if (mtd->pairing && mtd->pairing->get_info)
412 return mtd->pairing->get_info(mtd, wunit, info);
419 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
422 * mtd_wunit_to_pairing_info - get wunit from pairing information
423 * @mtd: pointer to new MTD device info structure
424 * @info: pairing information struct
426 * Returns a positive number representing the wunit associated to the info
427 * struct, or a negative error code.
429 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
430 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
433 * It can also be used to only program the first page of each pair (i.e.
434 * page attached to group 0), which allows one to use an MLC NAND in
435 * software-emulated SLC mode:
438 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
439 * for (info.pair = 0; info.pair < npairs; info.pair++) {
440 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
441 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
442 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
445 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
446 const struct mtd_pairing_info *info)
448 int ngroups = mtd_pairing_groups(mtd);
449 int npairs = mtd_wunit_per_eb(mtd) / ngroups;
451 if (!info || info->pair < 0 || info->pair >= npairs ||
452 info->group < 0 || info->group >= ngroups)
455 if (mtd->pairing && mtd->pairing->get_wunit)
456 return mtd->pairing->get_wunit(mtd, info);
460 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
463 * mtd_pairing_groups - get the number of pairing groups
464 * @mtd: pointer to new MTD device info structure
466 * Returns the number of pairing groups.
468 * This number is usually equal to the number of bits exposed by a single
469 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
470 * to iterate over all pages of a given pair.
472 int mtd_pairing_groups(struct mtd_info *mtd)
474 if (!mtd->pairing || !mtd->pairing->ngroups)
477 return mtd->pairing->ngroups;
479 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
481 static struct dentry *dfs_dir_mtd;
484 * add_mtd_device - register an MTD device
485 * @mtd: pointer to new MTD device info structure
487 * Add a device to the list of MTD devices present in the system, and
488 * notify each currently active MTD 'user' of its arrival. Returns
489 * zero on success or non-zero on failure.
492 int add_mtd_device(struct mtd_info *mtd)
494 struct mtd_notifier *not;
498 * May occur, for instance, on buggy drivers which call
499 * mtd_device_parse_register() multiple times on the same master MTD,
500 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
502 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
505 BUG_ON(mtd->writesize == 0);
506 mutex_lock(&mtd_table_mutex);
508 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
517 /* default value if not set by driver */
518 if (mtd->bitflip_threshold == 0)
519 mtd->bitflip_threshold = mtd->ecc_strength;
521 if (is_power_of_2(mtd->erasesize))
522 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
524 mtd->erasesize_shift = 0;
526 if (is_power_of_2(mtd->writesize))
527 mtd->writesize_shift = ffs(mtd->writesize) - 1;
529 mtd->writesize_shift = 0;
531 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
532 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
534 /* Some chips always power up locked. Unlock them now */
535 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
536 error = mtd_unlock(mtd, 0, mtd->size);
537 if (error && error != -EOPNOTSUPP)
539 "%s: unlock failed, writes may not work\n",
541 /* Ignore unlock failures? */
545 /* Caller should have set dev.parent to match the
546 * physical device, if appropriate.
548 mtd->dev.type = &mtd_devtype;
549 mtd->dev.class = &mtd_class;
550 mtd->dev.devt = MTD_DEVT(i);
551 dev_set_name(&mtd->dev, "mtd%d", i);
552 dev_set_drvdata(&mtd->dev, mtd);
553 of_node_get(mtd_get_of_node(mtd));
554 error = device_register(&mtd->dev);
556 put_device(&mtd->dev);
560 if (!IS_ERR_OR_NULL(dfs_dir_mtd)) {
561 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(&mtd->dev), dfs_dir_mtd);
562 if (IS_ERR_OR_NULL(mtd->dbg.dfs_dir)) {
563 pr_debug("mtd device %s won't show data in debugfs\n",
564 dev_name(&mtd->dev));
568 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
571 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
572 /* No need to get a refcount on the module containing
573 the notifier, since we hold the mtd_table_mutex */
574 list_for_each_entry(not, &mtd_notifiers, list)
577 mutex_unlock(&mtd_table_mutex);
578 /* We _know_ we aren't being removed, because
579 our caller is still holding us here. So none
580 of this try_ nonsense, and no bitching about it
582 __module_get(THIS_MODULE);
586 of_node_put(mtd_get_of_node(mtd));
587 idr_remove(&mtd_idr, i);
589 mutex_unlock(&mtd_table_mutex);
594 * del_mtd_device - unregister an MTD device
595 * @mtd: pointer to MTD device info structure
597 * Remove a device from the list of MTD devices present in the system,
598 * and notify each currently active MTD 'user' of its departure.
599 * Returns zero on success or 1 on failure, which currently will happen
600 * if the requested device does not appear to be present in the list.
603 int del_mtd_device(struct mtd_info *mtd)
606 struct mtd_notifier *not;
608 mutex_lock(&mtd_table_mutex);
610 debugfs_remove_recursive(mtd->dbg.dfs_dir);
612 if (idr_find(&mtd_idr, mtd->index) != mtd) {
617 /* No need to get a refcount on the module containing
618 the notifier, since we hold the mtd_table_mutex */
619 list_for_each_entry(not, &mtd_notifiers, list)
623 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
624 mtd->index, mtd->name, mtd->usecount);
627 device_unregister(&mtd->dev);
629 idr_remove(&mtd_idr, mtd->index);
630 of_node_put(mtd_get_of_node(mtd));
632 module_put(THIS_MODULE);
637 mutex_unlock(&mtd_table_mutex);
641 static int mtd_add_device_partitions(struct mtd_info *mtd,
642 struct mtd_partitions *parts)
644 const struct mtd_partition *real_parts = parts->parts;
645 int nbparts = parts->nr_parts;
648 if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
649 ret = add_mtd_device(mtd);
655 ret = add_mtd_partitions(mtd, real_parts, nbparts);
656 if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
665 * Set a few defaults based on the parent devices, if not provided by the
668 static void mtd_set_dev_defaults(struct mtd_info *mtd)
670 if (mtd->dev.parent) {
671 if (!mtd->owner && mtd->dev.parent->driver)
672 mtd->owner = mtd->dev.parent->driver->owner;
674 mtd->name = dev_name(mtd->dev.parent);
676 pr_debug("mtd device won't show a device symlink in sysfs\n");
681 * mtd_device_parse_register - parse partitions and register an MTD device.
683 * @mtd: the MTD device to register
684 * @types: the list of MTD partition probes to try, see
685 * 'parse_mtd_partitions()' for more information
686 * @parser_data: MTD partition parser-specific data
687 * @parts: fallback partition information to register, if parsing fails;
688 * only valid if %nr_parts > %0
689 * @nr_parts: the number of partitions in parts, if zero then the full
690 * MTD device is registered if no partition info is found
692 * This function aggregates MTD partitions parsing (done by
693 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
694 * basically follows the most common pattern found in many MTD drivers:
696 * * It first tries to probe partitions on MTD device @mtd using parsers
697 * specified in @types (if @types is %NULL, then the default list of parsers
698 * is used, see 'parse_mtd_partitions()' for more information). If none are
699 * found this functions tries to fallback to information specified in
701 * * If any partitioning info was found, this function registers the found
702 * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
703 * as a whole is registered first.
704 * * If no partitions were found this function just registers the MTD device
707 * Returns zero in case of success and a negative error code in case of failure.
709 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
710 struct mtd_part_parser_data *parser_data,
711 const struct mtd_partition *parts,
714 struct mtd_partitions parsed;
717 mtd_set_dev_defaults(mtd);
719 memset(&parsed, 0, sizeof(parsed));
721 ret = parse_mtd_partitions(mtd, types, &parsed, parser_data);
722 if ((ret < 0 || parsed.nr_parts == 0) && parts && nr_parts) {
723 /* Fall back to driver-provided partitions */
724 parsed = (struct mtd_partitions){
726 .nr_parts = nr_parts,
728 } else if (ret < 0) {
729 /* Didn't come up with parsed OR fallback partitions */
730 pr_info("mtd: failed to find partitions; one or more parsers reports errors (%d)\n",
732 /* Don't abort on errors; we can still use unpartitioned MTD */
733 memset(&parsed, 0, sizeof(parsed));
736 ret = mtd_add_device_partitions(mtd, &parsed);
741 * FIXME: some drivers unfortunately call this function more than once.
742 * So we have to check if we've already assigned the reboot notifier.
744 * Generally, we can make multiple calls work for most cases, but it
745 * does cause problems with parse_mtd_partitions() above (e.g.,
746 * cmdlineparts will register partitions more than once).
748 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
749 "MTD already registered\n");
750 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
751 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
752 register_reboot_notifier(&mtd->reboot_notifier);
756 /* Cleanup any parsed partitions */
757 mtd_part_parser_cleanup(&parsed);
760 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
763 * mtd_device_unregister - unregister an existing MTD device.
765 * @master: the MTD device to unregister. This will unregister both the master
766 * and any partitions if registered.
768 int mtd_device_unregister(struct mtd_info *master)
773 unregister_reboot_notifier(&master->reboot_notifier);
775 err = del_mtd_partitions(master);
779 if (!device_is_registered(&master->dev))
782 return del_mtd_device(master);
784 EXPORT_SYMBOL_GPL(mtd_device_unregister);
787 * register_mtd_user - register a 'user' of MTD devices.
788 * @new: pointer to notifier info structure
790 * Registers a pair of callbacks function to be called upon addition
791 * or removal of MTD devices. Causes the 'add' callback to be immediately
792 * invoked for each MTD device currently present in the system.
794 void register_mtd_user (struct mtd_notifier *new)
796 struct mtd_info *mtd;
798 mutex_lock(&mtd_table_mutex);
800 list_add(&new->list, &mtd_notifiers);
802 __module_get(THIS_MODULE);
804 mtd_for_each_device(mtd)
807 mutex_unlock(&mtd_table_mutex);
809 EXPORT_SYMBOL_GPL(register_mtd_user);
812 * unregister_mtd_user - unregister a 'user' of MTD devices.
813 * @old: pointer to notifier info structure
815 * Removes a callback function pair from the list of 'users' to be
816 * notified upon addition or removal of MTD devices. Causes the
817 * 'remove' callback to be immediately invoked for each MTD device
818 * currently present in the system.
820 int unregister_mtd_user (struct mtd_notifier *old)
822 struct mtd_info *mtd;
824 mutex_lock(&mtd_table_mutex);
826 module_put(THIS_MODULE);
828 mtd_for_each_device(mtd)
831 list_del(&old->list);
832 mutex_unlock(&mtd_table_mutex);
835 EXPORT_SYMBOL_GPL(unregister_mtd_user);
838 * get_mtd_device - obtain a validated handle for an MTD device
839 * @mtd: last known address of the required MTD device
840 * @num: internal device number of the required MTD device
842 * Given a number and NULL address, return the num'th entry in the device
843 * table, if any. Given an address and num == -1, search the device table
844 * for a device with that address and return if it's still present. Given
845 * both, return the num'th driver only if its address matches. Return
848 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
850 struct mtd_info *ret = NULL, *other;
853 mutex_lock(&mtd_table_mutex);
856 mtd_for_each_device(other) {
862 } else if (num >= 0) {
863 ret = idr_find(&mtd_idr, num);
864 if (mtd && mtd != ret)
873 err = __get_mtd_device(ret);
877 mutex_unlock(&mtd_table_mutex);
880 EXPORT_SYMBOL_GPL(get_mtd_device);
883 int __get_mtd_device(struct mtd_info *mtd)
887 if (!try_module_get(mtd->owner))
890 if (mtd->_get_device) {
891 err = mtd->_get_device(mtd);
894 module_put(mtd->owner);
901 EXPORT_SYMBOL_GPL(__get_mtd_device);
904 * get_mtd_device_nm - obtain a validated handle for an MTD device by
906 * @name: MTD device name to open
908 * This function returns MTD device description structure in case of
909 * success and an error code in case of failure.
911 struct mtd_info *get_mtd_device_nm(const char *name)
914 struct mtd_info *mtd = NULL, *other;
916 mutex_lock(&mtd_table_mutex);
918 mtd_for_each_device(other) {
919 if (!strcmp(name, other->name)) {
928 err = __get_mtd_device(mtd);
932 mutex_unlock(&mtd_table_mutex);
936 mutex_unlock(&mtd_table_mutex);
939 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
941 void put_mtd_device(struct mtd_info *mtd)
943 mutex_lock(&mtd_table_mutex);
944 __put_mtd_device(mtd);
945 mutex_unlock(&mtd_table_mutex);
948 EXPORT_SYMBOL_GPL(put_mtd_device);
950 void __put_mtd_device(struct mtd_info *mtd)
953 BUG_ON(mtd->usecount < 0);
955 if (mtd->_put_device)
956 mtd->_put_device(mtd);
958 module_put(mtd->owner);
960 EXPORT_SYMBOL_GPL(__put_mtd_device);
963 * Erase is an asynchronous operation. Device drivers are supposed
964 * to call instr->callback() whenever the operation completes, even
965 * if it completes with a failure.
966 * Callers are supposed to pass a callback function and wait for it
967 * to be called before writing to the block.
969 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
971 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
973 if (!(mtd->flags & MTD_WRITEABLE))
975 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
977 instr->state = MTD_ERASE_DONE;
978 mtd_erase_callback(instr);
981 ledtrig_mtd_activity();
982 return mtd->_erase(mtd, instr);
984 EXPORT_SYMBOL_GPL(mtd_erase);
987 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
989 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
990 void **virt, resource_size_t *phys)
998 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1002 return mtd->_point(mtd, from, len, retlen, virt, phys);
1004 EXPORT_SYMBOL_GPL(mtd_point);
1006 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1007 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1011 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1015 return mtd->_unpoint(mtd, from, len);
1017 EXPORT_SYMBOL_GPL(mtd_unpoint);
1020 * Allow NOMMU mmap() to directly map the device (if not NULL)
1021 * - return the address to which the offset maps
1022 * - return -ENOSYS to indicate refusal to do the mapping
1024 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1025 unsigned long offset, unsigned long flags)
1027 if (!mtd->_get_unmapped_area)
1029 if (offset >= mtd->size || len > mtd->size - offset)
1031 return mtd->_get_unmapped_area(mtd, len, offset, flags);
1033 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1035 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1040 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1045 ledtrig_mtd_activity();
1047 * In the absence of an error, drivers return a non-negative integer
1048 * representing the maximum number of bitflips that were corrected on
1049 * any one ecc region (if applicable; zero otherwise).
1051 ret_code = mtd->_read(mtd, from, len, retlen, buf);
1052 if (unlikely(ret_code < 0))
1054 if (mtd->ecc_strength == 0)
1055 return 0; /* device lacks ecc */
1056 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1058 EXPORT_SYMBOL_GPL(mtd_read);
1060 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1064 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1066 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
1070 ledtrig_mtd_activity();
1071 return mtd->_write(mtd, to, len, retlen, buf);
1073 EXPORT_SYMBOL_GPL(mtd_write);
1076 * In blackbox flight recorder like scenarios we want to make successful writes
1077 * in interrupt context. panic_write() is only intended to be called when its
1078 * known the kernel is about to panic and we need the write to succeed. Since
1079 * the kernel is not going to be running for much longer, this function can
1080 * break locks and delay to ensure the write succeeds (but not sleep).
1082 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1086 if (!mtd->_panic_write)
1088 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1090 if (!(mtd->flags & MTD_WRITEABLE))
1094 return mtd->_panic_write(mtd, to, len, retlen, buf);
1096 EXPORT_SYMBOL_GPL(mtd_panic_write);
1098 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1101 ops->retlen = ops->oobretlen = 0;
1102 if (!mtd->_read_oob)
1105 ledtrig_mtd_activity();
1107 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1108 * similar to mtd->_read(), returning a non-negative integer
1109 * representing max bitflips. In other cases, mtd->_read_oob() may
1110 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1112 ret_code = mtd->_read_oob(mtd, from, ops);
1113 if (unlikely(ret_code < 0))
1115 if (mtd->ecc_strength == 0)
1116 return 0; /* device lacks ecc */
1117 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1119 EXPORT_SYMBOL_GPL(mtd_read_oob);
1121 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1122 struct mtd_oob_ops *ops)
1124 ops->retlen = ops->oobretlen = 0;
1125 if (!mtd->_write_oob)
1127 if (!(mtd->flags & MTD_WRITEABLE))
1129 ledtrig_mtd_activity();
1130 return mtd->_write_oob(mtd, to, ops);
1132 EXPORT_SYMBOL_GPL(mtd_write_oob);
1135 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1136 * @mtd: MTD device structure
1137 * @section: ECC section. Depending on the layout you may have all the ECC
1138 * bytes stored in a single contiguous section, or one section
1139 * per ECC chunk (and sometime several sections for a single ECC
1141 * @oobecc: OOB region struct filled with the appropriate ECC position
1144 * This function returns ECC section information in the OOB area. If you want
1145 * to get all the ECC bytes information, then you should call
1146 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1148 * Returns zero on success, a negative error code otherwise.
1150 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1151 struct mtd_oob_region *oobecc)
1153 memset(oobecc, 0, sizeof(*oobecc));
1155 if (!mtd || section < 0)
1158 if (!mtd->ooblayout || !mtd->ooblayout->ecc)
1161 return mtd->ooblayout->ecc(mtd, section, oobecc);
1163 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1166 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1168 * @mtd: MTD device structure
1169 * @section: Free section you are interested in. Depending on the layout
1170 * you may have all the free bytes stored in a single contiguous
1171 * section, or one section per ECC chunk plus an extra section
1172 * for the remaining bytes (or other funky layout).
1173 * @oobfree: OOB region struct filled with the appropriate free position
1176 * This function returns free bytes position in the OOB area. If you want
1177 * to get all the free bytes information, then you should call
1178 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1180 * Returns zero on success, a negative error code otherwise.
1182 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1183 struct mtd_oob_region *oobfree)
1185 memset(oobfree, 0, sizeof(*oobfree));
1187 if (!mtd || section < 0)
1190 if (!mtd->ooblayout || !mtd->ooblayout->free)
1193 return mtd->ooblayout->free(mtd, section, oobfree);
1195 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1198 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1199 * @mtd: mtd info structure
1200 * @byte: the byte we are searching for
1201 * @sectionp: pointer where the section id will be stored
1202 * @oobregion: used to retrieve the ECC position
1203 * @iter: iterator function. Should be either mtd_ooblayout_free or
1204 * mtd_ooblayout_ecc depending on the region type you're searching for
1206 * This function returns the section id and oobregion information of a
1207 * specific byte. For example, say you want to know where the 4th ECC byte is
1208 * stored, you'll use:
1210 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1212 * Returns zero on success, a negative error code otherwise.
1214 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1215 int *sectionp, struct mtd_oob_region *oobregion,
1216 int (*iter)(struct mtd_info *,
1218 struct mtd_oob_region *oobregion))
1220 int pos = 0, ret, section = 0;
1222 memset(oobregion, 0, sizeof(*oobregion));
1225 ret = iter(mtd, section, oobregion);
1229 if (pos + oobregion->length > byte)
1232 pos += oobregion->length;
1237 * Adjust region info to make it start at the beginning at the
1240 oobregion->offset += byte - pos;
1241 oobregion->length -= byte - pos;
1242 *sectionp = section;
1248 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1250 * @mtd: mtd info structure
1251 * @eccbyte: the byte we are searching for
1252 * @sectionp: pointer where the section id will be stored
1253 * @oobregion: OOB region information
1255 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1258 * Returns zero on success, a negative error code otherwise.
1260 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1262 struct mtd_oob_region *oobregion)
1264 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1267 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1270 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1271 * @mtd: mtd info structure
1272 * @buf: destination buffer to store OOB bytes
1273 * @oobbuf: OOB buffer
1274 * @start: first byte to retrieve
1275 * @nbytes: number of bytes to retrieve
1276 * @iter: section iterator
1278 * Extract bytes attached to a specific category (ECC or free)
1279 * from the OOB buffer and copy them into buf.
1281 * Returns zero on success, a negative error code otherwise.
1283 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1284 const u8 *oobbuf, int start, int nbytes,
1285 int (*iter)(struct mtd_info *,
1287 struct mtd_oob_region *oobregion))
1289 struct mtd_oob_region oobregion;
1292 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1298 cnt = min_t(int, nbytes, oobregion.length);
1299 memcpy(buf, oobbuf + oobregion.offset, cnt);
1306 ret = iter(mtd, ++section, &oobregion);
1313 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1314 * @mtd: mtd info structure
1315 * @buf: source buffer to get OOB bytes from
1316 * @oobbuf: OOB buffer
1317 * @start: first OOB byte to set
1318 * @nbytes: number of OOB bytes to set
1319 * @iter: section iterator
1321 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1322 * is selected by passing the appropriate iterator.
1324 * Returns zero on success, a negative error code otherwise.
1326 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1327 u8 *oobbuf, int start, int nbytes,
1328 int (*iter)(struct mtd_info *,
1330 struct mtd_oob_region *oobregion))
1332 struct mtd_oob_region oobregion;
1335 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1341 cnt = min_t(int, nbytes, oobregion.length);
1342 memcpy(oobbuf + oobregion.offset, buf, cnt);
1349 ret = iter(mtd, ++section, &oobregion);
1356 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1357 * @mtd: mtd info structure
1358 * @iter: category iterator
1360 * Count the number of bytes in a given category.
1362 * Returns a positive value on success, a negative error code otherwise.
1364 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1365 int (*iter)(struct mtd_info *,
1367 struct mtd_oob_region *oobregion))
1369 struct mtd_oob_region oobregion;
1370 int section = 0, ret, nbytes = 0;
1373 ret = iter(mtd, section++, &oobregion);
1380 nbytes += oobregion.length;
1387 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1388 * @mtd: mtd info structure
1389 * @eccbuf: destination buffer to store ECC bytes
1390 * @oobbuf: OOB buffer
1391 * @start: first ECC byte to retrieve
1392 * @nbytes: number of ECC bytes to retrieve
1394 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1396 * Returns zero on success, a negative error code otherwise.
1398 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1399 const u8 *oobbuf, int start, int nbytes)
1401 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1404 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1407 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1408 * @mtd: mtd info structure
1409 * @eccbuf: source buffer to get ECC bytes from
1410 * @oobbuf: OOB buffer
1411 * @start: first ECC byte to set
1412 * @nbytes: number of ECC bytes to set
1414 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1416 * Returns zero on success, a negative error code otherwise.
1418 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1419 u8 *oobbuf, int start, int nbytes)
1421 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1424 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1427 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1428 * @mtd: mtd info structure
1429 * @databuf: destination buffer to store ECC bytes
1430 * @oobbuf: OOB buffer
1431 * @start: first ECC byte to retrieve
1432 * @nbytes: number of ECC bytes to retrieve
1434 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1436 * Returns zero on success, a negative error code otherwise.
1438 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1439 const u8 *oobbuf, int start, int nbytes)
1441 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1442 mtd_ooblayout_free);
1444 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1447 * mtd_ooblayout_get_eccbytes - set data bytes into the oob buffer
1448 * @mtd: mtd info structure
1449 * @eccbuf: source buffer to get data bytes from
1450 * @oobbuf: OOB buffer
1451 * @start: first ECC byte to set
1452 * @nbytes: number of ECC bytes to set
1454 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1456 * Returns zero on success, a negative error code otherwise.
1458 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1459 u8 *oobbuf, int start, int nbytes)
1461 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1462 mtd_ooblayout_free);
1464 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1467 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1468 * @mtd: mtd info structure
1470 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1472 * Returns zero on success, a negative error code otherwise.
1474 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1476 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1478 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1481 * mtd_ooblayout_count_freebytes - count the number of ECC bytes in OOB
1482 * @mtd: mtd info structure
1484 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1486 * Returns zero on success, a negative error code otherwise.
1488 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1490 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1492 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1495 * Method to access the protection register area, present in some flash
1496 * devices. The user data is one time programmable but the factory data is read
1499 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1500 struct otp_info *buf)
1502 if (!mtd->_get_fact_prot_info)
1506 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1508 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1510 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1511 size_t *retlen, u_char *buf)
1514 if (!mtd->_read_fact_prot_reg)
1518 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1520 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1522 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1523 struct otp_info *buf)
1525 if (!mtd->_get_user_prot_info)
1529 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1531 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1533 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1534 size_t *retlen, u_char *buf)
1537 if (!mtd->_read_user_prot_reg)
1541 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1543 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1545 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1546 size_t *retlen, u_char *buf)
1551 if (!mtd->_write_user_prot_reg)
1555 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1560 * If no data could be written at all, we are out of memory and
1561 * must return -ENOSPC.
1563 return (*retlen) ? 0 : -ENOSPC;
1565 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1567 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1569 if (!mtd->_lock_user_prot_reg)
1573 return mtd->_lock_user_prot_reg(mtd, from, len);
1575 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1577 /* Chip-supported device locking */
1578 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1582 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1586 return mtd->_lock(mtd, ofs, len);
1588 EXPORT_SYMBOL_GPL(mtd_lock);
1590 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1594 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1598 return mtd->_unlock(mtd, ofs, len);
1600 EXPORT_SYMBOL_GPL(mtd_unlock);
1602 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1604 if (!mtd->_is_locked)
1606 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1610 return mtd->_is_locked(mtd, ofs, len);
1612 EXPORT_SYMBOL_GPL(mtd_is_locked);
1614 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1616 if (ofs < 0 || ofs >= mtd->size)
1618 if (!mtd->_block_isreserved)
1620 return mtd->_block_isreserved(mtd, ofs);
1622 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1624 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1626 if (ofs < 0 || ofs >= mtd->size)
1628 if (!mtd->_block_isbad)
1630 return mtd->_block_isbad(mtd, ofs);
1632 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1634 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1636 if (!mtd->_block_markbad)
1638 if (ofs < 0 || ofs >= mtd->size)
1640 if (!(mtd->flags & MTD_WRITEABLE))
1642 return mtd->_block_markbad(mtd, ofs);
1644 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1647 * default_mtd_writev - the default writev method
1648 * @mtd: mtd device description object pointer
1649 * @vecs: the vectors to write
1650 * @count: count of vectors in @vecs
1651 * @to: the MTD device offset to write to
1652 * @retlen: on exit contains the count of bytes written to the MTD device.
1654 * This function returns zero in case of success and a negative error code in
1657 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1658 unsigned long count, loff_t to, size_t *retlen)
1661 size_t totlen = 0, thislen;
1664 for (i = 0; i < count; i++) {
1665 if (!vecs[i].iov_len)
1667 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1670 if (ret || thislen != vecs[i].iov_len)
1672 to += vecs[i].iov_len;
1679 * mtd_writev - the vector-based MTD write method
1680 * @mtd: mtd device description object pointer
1681 * @vecs: the vectors to write
1682 * @count: count of vectors in @vecs
1683 * @to: the MTD device offset to write to
1684 * @retlen: on exit contains the count of bytes written to the MTD device.
1686 * This function returns zero in case of success and a negative error code in
1689 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1690 unsigned long count, loff_t to, size_t *retlen)
1693 if (!(mtd->flags & MTD_WRITEABLE))
1696 return default_mtd_writev(mtd, vecs, count, to, retlen);
1697 return mtd->_writev(mtd, vecs, count, to, retlen);
1699 EXPORT_SYMBOL_GPL(mtd_writev);
1702 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1703 * @mtd: mtd device description object pointer
1704 * @size: a pointer to the ideal or maximum size of the allocation, points
1705 * to the actual allocation size on success.
1707 * This routine attempts to allocate a contiguous kernel buffer up to
1708 * the specified size, backing off the size of the request exponentially
1709 * until the request succeeds or until the allocation size falls below
1710 * the system page size. This attempts to make sure it does not adversely
1711 * impact system performance, so when allocating more than one page, we
1712 * ask the memory allocator to avoid re-trying, swapping, writing back
1713 * or performing I/O.
1715 * Note, this function also makes sure that the allocated buffer is aligned to
1716 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1718 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1719 * to handle smaller (i.e. degraded) buffer allocations under low- or
1720 * fragmented-memory situations where such reduced allocations, from a
1721 * requested ideal, are allowed.
1723 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1725 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1727 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1728 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1731 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1733 while (*size > min_alloc) {
1734 kbuf = kmalloc(*size, flags);
1739 *size = ALIGN(*size, mtd->writesize);
1743 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1744 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1746 return kmalloc(*size, GFP_KERNEL);
1748 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1750 #ifdef CONFIG_PROC_FS
1752 /*====================================================================*/
1753 /* Support for /proc/mtd */
1755 static int mtd_proc_show(struct seq_file *m, void *v)
1757 struct mtd_info *mtd;
1759 seq_puts(m, "dev: size erasesize name\n");
1760 mutex_lock(&mtd_table_mutex);
1761 mtd_for_each_device(mtd) {
1762 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1763 mtd->index, (unsigned long long)mtd->size,
1764 mtd->erasesize, mtd->name);
1766 mutex_unlock(&mtd_table_mutex);
1770 static int mtd_proc_open(struct inode *inode, struct file *file)
1772 return single_open(file, mtd_proc_show, NULL);
1775 static const struct file_operations mtd_proc_ops = {
1776 .open = mtd_proc_open,
1778 .llseek = seq_lseek,
1779 .release = single_release,
1781 #endif /* CONFIG_PROC_FS */
1783 /*====================================================================*/
1786 static struct backing_dev_info * __init mtd_bdi_init(char *name)
1788 struct backing_dev_info *bdi;
1791 bdi = bdi_alloc(GFP_KERNEL);
1793 return ERR_PTR(-ENOMEM);
1797 * We put '-0' suffix to the name to get the same name format as we
1798 * used to get. Since this is called only once, we get a unique name.
1800 ret = bdi_register(bdi, "%.28s-0", name);
1804 return ret ? ERR_PTR(ret) : bdi;
1807 static struct proc_dir_entry *proc_mtd;
1809 static int __init init_mtd(void)
1813 ret = class_register(&mtd_class);
1817 mtd_bdi = mtd_bdi_init("mtd");
1818 if (IS_ERR(mtd_bdi)) {
1819 ret = PTR_ERR(mtd_bdi);
1823 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1825 ret = init_mtdchar();
1829 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
1835 remove_proc_entry("mtd", NULL);
1838 class_unregister(&mtd_class);
1840 pr_err("Error registering mtd class or bdi: %d\n", ret);
1844 static void __exit cleanup_mtd(void)
1846 debugfs_remove_recursive(dfs_dir_mtd);
1849 remove_proc_entry("mtd", NULL);
1850 class_unregister(&mtd_class);
1852 idr_destroy(&mtd_idr);
1855 module_init(init_mtd);
1856 module_exit(cleanup_mtd);
1858 MODULE_LICENSE("GPL");
1859 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1860 MODULE_DESCRIPTION("Core MTD registration and access routines");