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>
44 #include <linux/nvmem-provider.h>
46 #include <linux/mtd/mtd.h>
47 #include <linux/mtd/partitions.h>
51 struct backing_dev_info *mtd_bdi;
53 #ifdef CONFIG_PM_SLEEP
55 static int mtd_cls_suspend(struct device *dev)
57 struct mtd_info *mtd = dev_get_drvdata(dev);
59 return mtd ? mtd_suspend(mtd) : 0;
62 static int mtd_cls_resume(struct device *dev)
64 struct mtd_info *mtd = dev_get_drvdata(dev);
71 static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
72 #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
74 #define MTD_CLS_PM_OPS NULL
77 static struct class mtd_class = {
83 static DEFINE_IDR(mtd_idr);
85 /* These are exported solely for the purpose of mtd_blkdevs.c. You
86 should not use them for _anything_ else */
87 DEFINE_MUTEX(mtd_table_mutex);
88 EXPORT_SYMBOL_GPL(mtd_table_mutex);
90 struct mtd_info *__mtd_next_device(int i)
92 return idr_get_next(&mtd_idr, &i);
94 EXPORT_SYMBOL_GPL(__mtd_next_device);
96 static LIST_HEAD(mtd_notifiers);
99 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
101 /* REVISIT once MTD uses the driver model better, whoever allocates
102 * the mtd_info will probably want to use the release() hook...
104 static void mtd_release(struct device *dev)
106 struct mtd_info *mtd = dev_get_drvdata(dev);
107 dev_t index = MTD_DEVT(mtd->index);
109 /* remove /dev/mtdXro node */
110 device_destroy(&mtd_class, index + 1);
113 static ssize_t mtd_type_show(struct device *dev,
114 struct device_attribute *attr, char *buf)
116 struct mtd_info *mtd = dev_get_drvdata(dev);
141 case MTD_MLCNANDFLASH:
148 return snprintf(buf, PAGE_SIZE, "%s\n", type);
150 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
152 static ssize_t mtd_flags_show(struct device *dev,
153 struct device_attribute *attr, char *buf)
155 struct mtd_info *mtd = dev_get_drvdata(dev);
157 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
160 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
162 static ssize_t mtd_size_show(struct device *dev,
163 struct device_attribute *attr, char *buf)
165 struct mtd_info *mtd = dev_get_drvdata(dev);
167 return snprintf(buf, PAGE_SIZE, "%llu\n",
168 (unsigned long long)mtd->size);
171 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
173 static ssize_t mtd_erasesize_show(struct device *dev,
174 struct device_attribute *attr, char *buf)
176 struct mtd_info *mtd = dev_get_drvdata(dev);
178 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
181 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
183 static ssize_t mtd_writesize_show(struct device *dev,
184 struct device_attribute *attr, char *buf)
186 struct mtd_info *mtd = dev_get_drvdata(dev);
188 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
191 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
193 static ssize_t mtd_subpagesize_show(struct device *dev,
194 struct device_attribute *attr, char *buf)
196 struct mtd_info *mtd = dev_get_drvdata(dev);
197 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
199 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
202 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
204 static ssize_t mtd_oobsize_show(struct device *dev,
205 struct device_attribute *attr, char *buf)
207 struct mtd_info *mtd = dev_get_drvdata(dev);
209 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
212 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
214 static ssize_t mtd_oobavail_show(struct device *dev,
215 struct device_attribute *attr, char *buf)
217 struct mtd_info *mtd = dev_get_drvdata(dev);
219 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->oobavail);
221 static DEVICE_ATTR(oobavail, S_IRUGO, mtd_oobavail_show, NULL);
223 static ssize_t mtd_numeraseregions_show(struct device *dev,
224 struct device_attribute *attr, char *buf)
226 struct mtd_info *mtd = dev_get_drvdata(dev);
228 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
231 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
234 static ssize_t mtd_name_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, "%s\n", mtd->name);
242 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
244 static ssize_t mtd_ecc_strength_show(struct device *dev,
245 struct device_attribute *attr, char *buf)
247 struct mtd_info *mtd = dev_get_drvdata(dev);
249 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
251 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
253 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
254 struct device_attribute *attr,
257 struct mtd_info *mtd = dev_get_drvdata(dev);
259 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
262 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
263 struct device_attribute *attr,
264 const char *buf, size_t count)
266 struct mtd_info *mtd = dev_get_drvdata(dev);
267 unsigned int bitflip_threshold;
270 retval = kstrtouint(buf, 0, &bitflip_threshold);
274 mtd->bitflip_threshold = bitflip_threshold;
277 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
278 mtd_bitflip_threshold_show,
279 mtd_bitflip_threshold_store);
281 static ssize_t mtd_ecc_step_size_show(struct device *dev,
282 struct device_attribute *attr, char *buf)
284 struct mtd_info *mtd = dev_get_drvdata(dev);
286 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
289 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
291 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
292 struct device_attribute *attr, char *buf)
294 struct mtd_info *mtd = dev_get_drvdata(dev);
295 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
297 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
299 static DEVICE_ATTR(corrected_bits, S_IRUGO,
300 mtd_ecc_stats_corrected_show, NULL);
302 static ssize_t mtd_ecc_stats_errors_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->failed);
310 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
312 static ssize_t mtd_badblocks_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->badblocks);
320 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
322 static ssize_t mtd_bbtblocks_show(struct device *dev,
323 struct device_attribute *attr, char *buf)
325 struct mtd_info *mtd = dev_get_drvdata(dev);
326 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
328 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
330 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
332 static struct attribute *mtd_attrs[] = {
334 &dev_attr_flags.attr,
336 &dev_attr_erasesize.attr,
337 &dev_attr_writesize.attr,
338 &dev_attr_subpagesize.attr,
339 &dev_attr_oobsize.attr,
340 &dev_attr_oobavail.attr,
341 &dev_attr_numeraseregions.attr,
343 &dev_attr_ecc_strength.attr,
344 &dev_attr_ecc_step_size.attr,
345 &dev_attr_corrected_bits.attr,
346 &dev_attr_ecc_failures.attr,
347 &dev_attr_bad_blocks.attr,
348 &dev_attr_bbt_blocks.attr,
349 &dev_attr_bitflip_threshold.attr,
352 ATTRIBUTE_GROUPS(mtd);
354 static const struct device_type mtd_devtype = {
356 .groups = mtd_groups,
357 .release = mtd_release,
361 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
365 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
366 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
368 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
371 return NOMMU_MAP_COPY;
374 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
377 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
380 struct mtd_info *mtd;
382 mtd = container_of(n, struct mtd_info, reboot_notifier);
389 * mtd_wunit_to_pairing_info - get pairing information of a wunit
390 * @mtd: pointer to new MTD device info structure
391 * @wunit: write unit we are interested in
392 * @info: returned pairing information
394 * Retrieve pairing information associated to the wunit.
395 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
396 * paired together, and where programming a page may influence the page it is
398 * The notion of page is replaced by the term wunit (write-unit) to stay
399 * consistent with the ->writesize field.
401 * The @wunit argument can be extracted from an absolute offset using
402 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
405 * From the pairing info the MTD user can find all the wunits paired with
406 * @wunit using the following loop:
408 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
410 * mtd_pairing_info_to_wunit(mtd, &info);
414 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
415 struct mtd_pairing_info *info)
417 int npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
419 if (wunit < 0 || wunit >= npairs)
422 if (mtd->pairing && mtd->pairing->get_info)
423 return mtd->pairing->get_info(mtd, wunit, info);
430 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
433 * mtd_pairing_info_to_wunit - get wunit from pairing information
434 * @mtd: pointer to new MTD device info structure
435 * @info: pairing information struct
437 * Returns a positive number representing the wunit associated to the info
438 * struct, or a negative error code.
440 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
441 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
444 * It can also be used to only program the first page of each pair (i.e.
445 * page attached to group 0), which allows one to use an MLC NAND in
446 * software-emulated SLC mode:
449 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
450 * for (info.pair = 0; info.pair < npairs; info.pair++) {
451 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
452 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
453 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
456 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
457 const struct mtd_pairing_info *info)
459 int ngroups = mtd_pairing_groups(mtd);
460 int npairs = mtd_wunit_per_eb(mtd) / ngroups;
462 if (!info || info->pair < 0 || info->pair >= npairs ||
463 info->group < 0 || info->group >= ngroups)
466 if (mtd->pairing && mtd->pairing->get_wunit)
467 return mtd->pairing->get_wunit(mtd, info);
471 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
474 * mtd_pairing_groups - get the number of pairing groups
475 * @mtd: pointer to new MTD device info structure
477 * Returns the number of pairing groups.
479 * This number is usually equal to the number of bits exposed by a single
480 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
481 * to iterate over all pages of a given pair.
483 int mtd_pairing_groups(struct mtd_info *mtd)
485 if (!mtd->pairing || !mtd->pairing->ngroups)
488 return mtd->pairing->ngroups;
490 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
492 static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
493 void *val, size_t bytes)
495 struct mtd_info *mtd = priv;
499 err = mtd_read(mtd, offset, bytes, &retlen, val);
500 if (err && err != -EUCLEAN)
503 return retlen == bytes ? 0 : -EIO;
506 static int mtd_nvmem_add(struct mtd_info *mtd)
508 struct nvmem_config config = {};
511 config.dev = &mtd->dev;
512 config.name = mtd->name;
513 config.owner = THIS_MODULE;
514 config.reg_read = mtd_nvmem_reg_read;
515 config.size = mtd->size;
516 config.word_size = 1;
518 config.read_only = true;
519 config.root_only = true;
520 config.no_of_node = true;
523 mtd->nvmem = nvmem_register(&config);
524 if (IS_ERR(mtd->nvmem)) {
525 /* Just ignore if there is no NVMEM support in the kernel */
526 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
529 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
530 return PTR_ERR(mtd->nvmem);
537 static struct dentry *dfs_dir_mtd;
540 * add_mtd_device - register an MTD device
541 * @mtd: pointer to new MTD device info structure
543 * Add a device to the list of MTD devices present in the system, and
544 * notify each currently active MTD 'user' of its arrival. Returns
545 * zero on success or non-zero on failure.
548 int add_mtd_device(struct mtd_info *mtd)
550 struct mtd_notifier *not;
554 * May occur, for instance, on buggy drivers which call
555 * mtd_device_parse_register() multiple times on the same master MTD,
556 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
558 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
561 BUG_ON(mtd->writesize == 0);
563 if (WARN_ON((!mtd->erasesize || !mtd->_erase) &&
564 !(mtd->flags & MTD_NO_ERASE)))
567 mutex_lock(&mtd_table_mutex);
569 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
578 /* default value if not set by driver */
579 if (mtd->bitflip_threshold == 0)
580 mtd->bitflip_threshold = mtd->ecc_strength;
582 if (is_power_of_2(mtd->erasesize))
583 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
585 mtd->erasesize_shift = 0;
587 if (is_power_of_2(mtd->writesize))
588 mtd->writesize_shift = ffs(mtd->writesize) - 1;
590 mtd->writesize_shift = 0;
592 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
593 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
595 /* Some chips always power up locked. Unlock them now */
596 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
597 error = mtd_unlock(mtd, 0, mtd->size);
598 if (error && error != -EOPNOTSUPP)
600 "%s: unlock failed, writes may not work\n",
602 /* Ignore unlock failures? */
606 /* Caller should have set dev.parent to match the
607 * physical device, if appropriate.
609 mtd->dev.type = &mtd_devtype;
610 mtd->dev.class = &mtd_class;
611 mtd->dev.devt = MTD_DEVT(i);
612 dev_set_name(&mtd->dev, "mtd%d", i);
613 dev_set_drvdata(&mtd->dev, mtd);
614 of_node_get(mtd_get_of_node(mtd));
615 error = device_register(&mtd->dev);
619 /* Add the nvmem provider */
620 error = mtd_nvmem_add(mtd);
624 if (!IS_ERR_OR_NULL(dfs_dir_mtd)) {
625 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(&mtd->dev), dfs_dir_mtd);
626 if (IS_ERR_OR_NULL(mtd->dbg.dfs_dir)) {
627 pr_debug("mtd device %s won't show data in debugfs\n",
628 dev_name(&mtd->dev));
632 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
635 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
636 /* No need to get a refcount on the module containing
637 the notifier, since we hold the mtd_table_mutex */
638 list_for_each_entry(not, &mtd_notifiers, list)
641 mutex_unlock(&mtd_table_mutex);
642 /* We _know_ we aren't being removed, because
643 our caller is still holding us here. So none
644 of this try_ nonsense, and no bitching about it
646 __module_get(THIS_MODULE);
650 device_unregister(&mtd->dev);
652 of_node_put(mtd_get_of_node(mtd));
653 idr_remove(&mtd_idr, i);
655 mutex_unlock(&mtd_table_mutex);
660 * del_mtd_device - unregister an MTD device
661 * @mtd: pointer to MTD device info structure
663 * Remove a device from the list of MTD devices present in the system,
664 * and notify each currently active MTD 'user' of its departure.
665 * Returns zero on success or 1 on failure, which currently will happen
666 * if the requested device does not appear to be present in the list.
669 int del_mtd_device(struct mtd_info *mtd)
672 struct mtd_notifier *not;
674 mutex_lock(&mtd_table_mutex);
676 debugfs_remove_recursive(mtd->dbg.dfs_dir);
678 if (idr_find(&mtd_idr, mtd->index) != mtd) {
683 /* No need to get a refcount on the module containing
684 the notifier, since we hold the mtd_table_mutex */
685 list_for_each_entry(not, &mtd_notifiers, list)
689 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
690 mtd->index, mtd->name, mtd->usecount);
693 /* Try to remove the NVMEM provider */
695 nvmem_unregister(mtd->nvmem);
697 device_unregister(&mtd->dev);
699 idr_remove(&mtd_idr, mtd->index);
700 of_node_put(mtd_get_of_node(mtd));
702 module_put(THIS_MODULE);
707 mutex_unlock(&mtd_table_mutex);
712 * Set a few defaults based on the parent devices, if not provided by the
715 static void mtd_set_dev_defaults(struct mtd_info *mtd)
717 if (mtd->dev.parent) {
718 if (!mtd->owner && mtd->dev.parent->driver)
719 mtd->owner = mtd->dev.parent->driver->owner;
721 mtd->name = dev_name(mtd->dev.parent);
723 pr_debug("mtd device won't show a device symlink in sysfs\n");
726 mtd->orig_flags = mtd->flags;
730 * mtd_device_parse_register - parse partitions and register an MTD device.
732 * @mtd: the MTD device to register
733 * @types: the list of MTD partition probes to try, see
734 * 'parse_mtd_partitions()' for more information
735 * @parser_data: MTD partition parser-specific data
736 * @parts: fallback partition information to register, if parsing fails;
737 * only valid if %nr_parts > %0
738 * @nr_parts: the number of partitions in parts, if zero then the full
739 * MTD device is registered if no partition info is found
741 * This function aggregates MTD partitions parsing (done by
742 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
743 * basically follows the most common pattern found in many MTD drivers:
745 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
747 * * Then It tries to probe partitions on MTD device @mtd using parsers
748 * specified in @types (if @types is %NULL, then the default list of parsers
749 * is used, see 'parse_mtd_partitions()' for more information). If none are
750 * found this functions tries to fallback to information specified in
752 * * If no partitions were found this function just registers the MTD device
755 * Returns zero in case of success and a negative error code in case of failure.
757 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
758 struct mtd_part_parser_data *parser_data,
759 const struct mtd_partition *parts,
764 mtd_set_dev_defaults(mtd);
766 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
767 ret = add_mtd_device(mtd);
772 /* Prefer parsed partitions over driver-provided fallback */
773 ret = parse_mtd_partitions(mtd, types, parser_data);
777 ret = add_mtd_partitions(mtd, parts, nr_parts);
778 else if (!device_is_registered(&mtd->dev))
779 ret = add_mtd_device(mtd);
787 * FIXME: some drivers unfortunately call this function more than once.
788 * So we have to check if we've already assigned the reboot notifier.
790 * Generally, we can make multiple calls work for most cases, but it
791 * does cause problems with parse_mtd_partitions() above (e.g.,
792 * cmdlineparts will register partitions more than once).
794 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
795 "MTD already registered\n");
796 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
797 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
798 register_reboot_notifier(&mtd->reboot_notifier);
802 if (ret && device_is_registered(&mtd->dev))
807 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
810 * mtd_device_unregister - unregister an existing MTD device.
812 * @master: the MTD device to unregister. This will unregister both the master
813 * and any partitions if registered.
815 int mtd_device_unregister(struct mtd_info *master)
820 unregister_reboot_notifier(&master->reboot_notifier);
822 err = del_mtd_partitions(master);
826 if (!device_is_registered(&master->dev))
829 return del_mtd_device(master);
831 EXPORT_SYMBOL_GPL(mtd_device_unregister);
834 * register_mtd_user - register a 'user' of MTD devices.
835 * @new: pointer to notifier info structure
837 * Registers a pair of callbacks function to be called upon addition
838 * or removal of MTD devices. Causes the 'add' callback to be immediately
839 * invoked for each MTD device currently present in the system.
841 void register_mtd_user (struct mtd_notifier *new)
843 struct mtd_info *mtd;
845 mutex_lock(&mtd_table_mutex);
847 list_add(&new->list, &mtd_notifiers);
849 __module_get(THIS_MODULE);
851 mtd_for_each_device(mtd)
854 mutex_unlock(&mtd_table_mutex);
856 EXPORT_SYMBOL_GPL(register_mtd_user);
859 * unregister_mtd_user - unregister a 'user' of MTD devices.
860 * @old: pointer to notifier info structure
862 * Removes a callback function pair from the list of 'users' to be
863 * notified upon addition or removal of MTD devices. Causes the
864 * 'remove' callback to be immediately invoked for each MTD device
865 * currently present in the system.
867 int unregister_mtd_user (struct mtd_notifier *old)
869 struct mtd_info *mtd;
871 mutex_lock(&mtd_table_mutex);
873 module_put(THIS_MODULE);
875 mtd_for_each_device(mtd)
878 list_del(&old->list);
879 mutex_unlock(&mtd_table_mutex);
882 EXPORT_SYMBOL_GPL(unregister_mtd_user);
885 * get_mtd_device - obtain a validated handle for an MTD device
886 * @mtd: last known address of the required MTD device
887 * @num: internal device number of the required MTD device
889 * Given a number and NULL address, return the num'th entry in the device
890 * table, if any. Given an address and num == -1, search the device table
891 * for a device with that address and return if it's still present. Given
892 * both, return the num'th driver only if its address matches. Return
895 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
897 struct mtd_info *ret = NULL, *other;
900 mutex_lock(&mtd_table_mutex);
903 mtd_for_each_device(other) {
909 } else if (num >= 0) {
910 ret = idr_find(&mtd_idr, num);
911 if (mtd && mtd != ret)
920 err = __get_mtd_device(ret);
924 mutex_unlock(&mtd_table_mutex);
927 EXPORT_SYMBOL_GPL(get_mtd_device);
930 int __get_mtd_device(struct mtd_info *mtd)
934 if (!try_module_get(mtd->owner))
937 if (mtd->_get_device) {
938 err = mtd->_get_device(mtd);
941 module_put(mtd->owner);
948 EXPORT_SYMBOL_GPL(__get_mtd_device);
951 * get_mtd_device_nm - obtain a validated handle for an MTD device by
953 * @name: MTD device name to open
955 * This function returns MTD device description structure in case of
956 * success and an error code in case of failure.
958 struct mtd_info *get_mtd_device_nm(const char *name)
961 struct mtd_info *mtd = NULL, *other;
963 mutex_lock(&mtd_table_mutex);
965 mtd_for_each_device(other) {
966 if (!strcmp(name, other->name)) {
975 err = __get_mtd_device(mtd);
979 mutex_unlock(&mtd_table_mutex);
983 mutex_unlock(&mtd_table_mutex);
986 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
988 void put_mtd_device(struct mtd_info *mtd)
990 mutex_lock(&mtd_table_mutex);
991 __put_mtd_device(mtd);
992 mutex_unlock(&mtd_table_mutex);
995 EXPORT_SYMBOL_GPL(put_mtd_device);
997 void __put_mtd_device(struct mtd_info *mtd)
1000 BUG_ON(mtd->usecount < 0);
1002 if (mtd->_put_device)
1003 mtd->_put_device(mtd);
1005 module_put(mtd->owner);
1007 EXPORT_SYMBOL_GPL(__put_mtd_device);
1010 * Erase is an synchronous operation. Device drivers are epected to return a
1011 * negative error code if the operation failed and update instr->fail_addr
1012 * to point the portion that was not properly erased.
1014 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1016 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1018 if (!mtd->erasesize || !mtd->_erase)
1021 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1023 if (!(mtd->flags & MTD_WRITEABLE))
1029 ledtrig_mtd_activity();
1030 return mtd->_erase(mtd, instr);
1032 EXPORT_SYMBOL_GPL(mtd_erase);
1035 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1037 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1038 void **virt, resource_size_t *phys)
1046 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1050 return mtd->_point(mtd, from, len, retlen, virt, phys);
1052 EXPORT_SYMBOL_GPL(mtd_point);
1054 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1055 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1059 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1063 return mtd->_unpoint(mtd, from, len);
1065 EXPORT_SYMBOL_GPL(mtd_unpoint);
1068 * Allow NOMMU mmap() to directly map the device (if not NULL)
1069 * - return the address to which the offset maps
1070 * - return -ENOSYS to indicate refusal to do the mapping
1072 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1073 unsigned long offset, unsigned long flags)
1079 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1082 if (retlen != len) {
1083 mtd_unpoint(mtd, offset, retlen);
1086 return (unsigned long)virt;
1088 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1090 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1095 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1100 ledtrig_mtd_activity();
1102 * In the absence of an error, drivers return a non-negative integer
1103 * representing the maximum number of bitflips that were corrected on
1104 * any one ecc region (if applicable; zero otherwise).
1107 ret_code = mtd->_read(mtd, from, len, retlen, buf);
1108 } else if (mtd->_read_oob) {
1109 struct mtd_oob_ops ops = {
1114 ret_code = mtd->_read_oob(mtd, from, &ops);
1115 *retlen = ops.retlen;
1120 if (unlikely(ret_code < 0))
1122 if (mtd->ecc_strength == 0)
1123 return 0; /* device lacks ecc */
1124 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1126 EXPORT_SYMBOL_GPL(mtd_read);
1128 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1132 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1134 if ((!mtd->_write && !mtd->_write_oob) ||
1135 !(mtd->flags & MTD_WRITEABLE))
1139 ledtrig_mtd_activity();
1142 struct mtd_oob_ops ops = {
1144 .datbuf = (u8 *)buf,
1148 ret = mtd->_write_oob(mtd, to, &ops);
1149 *retlen = ops.retlen;
1153 return mtd->_write(mtd, to, len, retlen, buf);
1155 EXPORT_SYMBOL_GPL(mtd_write);
1158 * In blackbox flight recorder like scenarios we want to make successful writes
1159 * in interrupt context. panic_write() is only intended to be called when its
1160 * known the kernel is about to panic and we need the write to succeed. Since
1161 * the kernel is not going to be running for much longer, this function can
1162 * break locks and delay to ensure the write succeeds (but not sleep).
1164 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1168 if (!mtd->_panic_write)
1170 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1172 if (!(mtd->flags & MTD_WRITEABLE))
1176 return mtd->_panic_write(mtd, to, len, retlen, buf);
1178 EXPORT_SYMBOL_GPL(mtd_panic_write);
1180 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1181 struct mtd_oob_ops *ops)
1184 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1185 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1194 if (offs < 0 || offs + ops->len > mtd->size)
1200 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1203 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1204 mtd_div_by_ws(offs, mtd)) *
1205 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1206 if (ops->ooblen > maxooblen)
1213 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1216 ops->retlen = ops->oobretlen = 0;
1218 ret_code = mtd_check_oob_ops(mtd, from, ops);
1222 ledtrig_mtd_activity();
1224 /* Check the validity of a potential fallback on mtd->_read */
1225 if (!mtd->_read_oob && (!mtd->_read || ops->oobbuf))
1229 ret_code = mtd->_read_oob(mtd, from, ops);
1231 ret_code = mtd->_read(mtd, from, ops->len, &ops->retlen,
1235 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1236 * similar to mtd->_read(), returning a non-negative integer
1237 * representing max bitflips. In other cases, mtd->_read_oob() may
1238 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1240 if (unlikely(ret_code < 0))
1242 if (mtd->ecc_strength == 0)
1243 return 0; /* device lacks ecc */
1244 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1246 EXPORT_SYMBOL_GPL(mtd_read_oob);
1248 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1249 struct mtd_oob_ops *ops)
1253 ops->retlen = ops->oobretlen = 0;
1255 if (!(mtd->flags & MTD_WRITEABLE))
1258 ret = mtd_check_oob_ops(mtd, to, ops);
1262 ledtrig_mtd_activity();
1264 /* Check the validity of a potential fallback on mtd->_write */
1265 if (!mtd->_write_oob && (!mtd->_write || ops->oobbuf))
1268 if (mtd->_write_oob)
1269 return mtd->_write_oob(mtd, to, ops);
1271 return mtd->_write(mtd, to, ops->len, &ops->retlen,
1274 EXPORT_SYMBOL_GPL(mtd_write_oob);
1277 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1278 * @mtd: MTD device structure
1279 * @section: ECC section. Depending on the layout you may have all the ECC
1280 * bytes stored in a single contiguous section, or one section
1281 * per ECC chunk (and sometime several sections for a single ECC
1283 * @oobecc: OOB region struct filled with the appropriate ECC position
1286 * This function returns ECC section information in the OOB area. If you want
1287 * to get all the ECC bytes information, then you should call
1288 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1290 * Returns zero on success, a negative error code otherwise.
1292 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1293 struct mtd_oob_region *oobecc)
1295 memset(oobecc, 0, sizeof(*oobecc));
1297 if (!mtd || section < 0)
1300 if (!mtd->ooblayout || !mtd->ooblayout->ecc)
1303 return mtd->ooblayout->ecc(mtd, section, oobecc);
1305 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1308 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1310 * @mtd: MTD device structure
1311 * @section: Free section you are interested in. Depending on the layout
1312 * you may have all the free bytes stored in a single contiguous
1313 * section, or one section per ECC chunk plus an extra section
1314 * for the remaining bytes (or other funky layout).
1315 * @oobfree: OOB region struct filled with the appropriate free position
1318 * This function returns free bytes position in the OOB area. If you want
1319 * to get all the free bytes information, then you should call
1320 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1322 * Returns zero on success, a negative error code otherwise.
1324 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1325 struct mtd_oob_region *oobfree)
1327 memset(oobfree, 0, sizeof(*oobfree));
1329 if (!mtd || section < 0)
1332 if (!mtd->ooblayout || !mtd->ooblayout->free)
1335 return mtd->ooblayout->free(mtd, section, oobfree);
1337 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1340 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1341 * @mtd: mtd info structure
1342 * @byte: the byte we are searching for
1343 * @sectionp: pointer where the section id will be stored
1344 * @oobregion: used to retrieve the ECC position
1345 * @iter: iterator function. Should be either mtd_ooblayout_free or
1346 * mtd_ooblayout_ecc depending on the region type you're searching for
1348 * This function returns the section id and oobregion information of a
1349 * specific byte. For example, say you want to know where the 4th ECC byte is
1350 * stored, you'll use:
1352 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1354 * Returns zero on success, a negative error code otherwise.
1356 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1357 int *sectionp, struct mtd_oob_region *oobregion,
1358 int (*iter)(struct mtd_info *,
1360 struct mtd_oob_region *oobregion))
1362 int pos = 0, ret, section = 0;
1364 memset(oobregion, 0, sizeof(*oobregion));
1367 ret = iter(mtd, section, oobregion);
1371 if (pos + oobregion->length > byte)
1374 pos += oobregion->length;
1379 * Adjust region info to make it start at the beginning at the
1382 oobregion->offset += byte - pos;
1383 oobregion->length -= byte - pos;
1384 *sectionp = section;
1390 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1392 * @mtd: mtd info structure
1393 * @eccbyte: the byte we are searching for
1394 * @sectionp: pointer where the section id will be stored
1395 * @oobregion: OOB region information
1397 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1400 * Returns zero on success, a negative error code otherwise.
1402 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1404 struct mtd_oob_region *oobregion)
1406 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1409 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1412 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1413 * @mtd: mtd info structure
1414 * @buf: destination buffer to store OOB bytes
1415 * @oobbuf: OOB buffer
1416 * @start: first byte to retrieve
1417 * @nbytes: number of bytes to retrieve
1418 * @iter: section iterator
1420 * Extract bytes attached to a specific category (ECC or free)
1421 * from the OOB buffer and copy them into buf.
1423 * Returns zero on success, a negative error code otherwise.
1425 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1426 const u8 *oobbuf, int start, int nbytes,
1427 int (*iter)(struct mtd_info *,
1429 struct mtd_oob_region *oobregion))
1431 struct mtd_oob_region oobregion;
1434 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1440 cnt = min_t(int, nbytes, oobregion.length);
1441 memcpy(buf, oobbuf + oobregion.offset, cnt);
1448 ret = iter(mtd, ++section, &oobregion);
1455 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1456 * @mtd: mtd info structure
1457 * @buf: source buffer to get OOB bytes from
1458 * @oobbuf: OOB buffer
1459 * @start: first OOB byte to set
1460 * @nbytes: number of OOB bytes to set
1461 * @iter: section iterator
1463 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1464 * is selected by passing the appropriate iterator.
1466 * Returns zero on success, a negative error code otherwise.
1468 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1469 u8 *oobbuf, int start, int nbytes,
1470 int (*iter)(struct mtd_info *,
1472 struct mtd_oob_region *oobregion))
1474 struct mtd_oob_region oobregion;
1477 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1483 cnt = min_t(int, nbytes, oobregion.length);
1484 memcpy(oobbuf + oobregion.offset, buf, cnt);
1491 ret = iter(mtd, ++section, &oobregion);
1498 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1499 * @mtd: mtd info structure
1500 * @iter: category iterator
1502 * Count the number of bytes in a given category.
1504 * Returns a positive value on success, a negative error code otherwise.
1506 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1507 int (*iter)(struct mtd_info *,
1509 struct mtd_oob_region *oobregion))
1511 struct mtd_oob_region oobregion;
1512 int section = 0, ret, nbytes = 0;
1515 ret = iter(mtd, section++, &oobregion);
1522 nbytes += oobregion.length;
1529 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1530 * @mtd: mtd info structure
1531 * @eccbuf: destination buffer to store ECC bytes
1532 * @oobbuf: OOB buffer
1533 * @start: first ECC byte to retrieve
1534 * @nbytes: number of ECC bytes to retrieve
1536 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1538 * Returns zero on success, a negative error code otherwise.
1540 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1541 const u8 *oobbuf, int start, int nbytes)
1543 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1546 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1549 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1550 * @mtd: mtd info structure
1551 * @eccbuf: source buffer to get ECC bytes from
1552 * @oobbuf: OOB buffer
1553 * @start: first ECC byte to set
1554 * @nbytes: number of ECC bytes to set
1556 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1558 * Returns zero on success, a negative error code otherwise.
1560 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1561 u8 *oobbuf, int start, int nbytes)
1563 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1566 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1569 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1570 * @mtd: mtd info structure
1571 * @databuf: destination buffer to store ECC bytes
1572 * @oobbuf: OOB buffer
1573 * @start: first ECC byte to retrieve
1574 * @nbytes: number of ECC bytes to retrieve
1576 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1578 * Returns zero on success, a negative error code otherwise.
1580 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1581 const u8 *oobbuf, int start, int nbytes)
1583 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1584 mtd_ooblayout_free);
1586 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1589 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1590 * @mtd: mtd info structure
1591 * @databuf: source buffer to get data bytes from
1592 * @oobbuf: OOB buffer
1593 * @start: first ECC byte to set
1594 * @nbytes: number of ECC bytes to set
1596 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1598 * Returns zero on success, a negative error code otherwise.
1600 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1601 u8 *oobbuf, int start, int nbytes)
1603 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1604 mtd_ooblayout_free);
1606 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1609 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1610 * @mtd: mtd info structure
1612 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1614 * Returns zero on success, a negative error code otherwise.
1616 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1618 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1620 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1623 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1624 * @mtd: mtd info structure
1626 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1628 * Returns zero on success, a negative error code otherwise.
1630 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1632 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1634 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1637 * Method to access the protection register area, present in some flash
1638 * devices. The user data is one time programmable but the factory data is read
1641 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1642 struct otp_info *buf)
1644 if (!mtd->_get_fact_prot_info)
1648 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1650 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1652 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1653 size_t *retlen, u_char *buf)
1656 if (!mtd->_read_fact_prot_reg)
1660 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1662 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1664 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1665 struct otp_info *buf)
1667 if (!mtd->_get_user_prot_info)
1671 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1673 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1675 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1676 size_t *retlen, u_char *buf)
1679 if (!mtd->_read_user_prot_reg)
1683 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1685 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1687 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1688 size_t *retlen, u_char *buf)
1693 if (!mtd->_write_user_prot_reg)
1697 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1702 * If no data could be written at all, we are out of memory and
1703 * must return -ENOSPC.
1705 return (*retlen) ? 0 : -ENOSPC;
1707 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1709 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1711 if (!mtd->_lock_user_prot_reg)
1715 return mtd->_lock_user_prot_reg(mtd, from, len);
1717 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1719 /* Chip-supported device locking */
1720 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1724 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1728 return mtd->_lock(mtd, ofs, len);
1730 EXPORT_SYMBOL_GPL(mtd_lock);
1732 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1736 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1740 return mtd->_unlock(mtd, ofs, len);
1742 EXPORT_SYMBOL_GPL(mtd_unlock);
1744 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1746 if (!mtd->_is_locked)
1748 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1752 return mtd->_is_locked(mtd, ofs, len);
1754 EXPORT_SYMBOL_GPL(mtd_is_locked);
1756 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1758 if (ofs < 0 || ofs >= mtd->size)
1760 if (!mtd->_block_isreserved)
1762 return mtd->_block_isreserved(mtd, ofs);
1764 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1766 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1768 if (ofs < 0 || ofs >= mtd->size)
1770 if (!mtd->_block_isbad)
1772 return mtd->_block_isbad(mtd, ofs);
1774 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1776 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1778 if (!mtd->_block_markbad)
1780 if (ofs < 0 || ofs >= mtd->size)
1782 if (!(mtd->flags & MTD_WRITEABLE))
1784 return mtd->_block_markbad(mtd, ofs);
1786 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1789 * default_mtd_writev - the default writev method
1790 * @mtd: mtd device description object pointer
1791 * @vecs: the vectors to write
1792 * @count: count of vectors in @vecs
1793 * @to: the MTD device offset to write to
1794 * @retlen: on exit contains the count of bytes written to the MTD device.
1796 * This function returns zero in case of success and a negative error code in
1799 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1800 unsigned long count, loff_t to, size_t *retlen)
1803 size_t totlen = 0, thislen;
1806 for (i = 0; i < count; i++) {
1807 if (!vecs[i].iov_len)
1809 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1812 if (ret || thislen != vecs[i].iov_len)
1814 to += vecs[i].iov_len;
1821 * mtd_writev - the vector-based MTD write method
1822 * @mtd: mtd device description object pointer
1823 * @vecs: the vectors to write
1824 * @count: count of vectors in @vecs
1825 * @to: the MTD device offset to write to
1826 * @retlen: on exit contains the count of bytes written to the MTD device.
1828 * This function returns zero in case of success and a negative error code in
1831 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1832 unsigned long count, loff_t to, size_t *retlen)
1835 if (!(mtd->flags & MTD_WRITEABLE))
1838 return default_mtd_writev(mtd, vecs, count, to, retlen);
1839 return mtd->_writev(mtd, vecs, count, to, retlen);
1841 EXPORT_SYMBOL_GPL(mtd_writev);
1844 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1845 * @mtd: mtd device description object pointer
1846 * @size: a pointer to the ideal or maximum size of the allocation, points
1847 * to the actual allocation size on success.
1849 * This routine attempts to allocate a contiguous kernel buffer up to
1850 * the specified size, backing off the size of the request exponentially
1851 * until the request succeeds or until the allocation size falls below
1852 * the system page size. This attempts to make sure it does not adversely
1853 * impact system performance, so when allocating more than one page, we
1854 * ask the memory allocator to avoid re-trying, swapping, writing back
1855 * or performing I/O.
1857 * Note, this function also makes sure that the allocated buffer is aligned to
1858 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1860 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1861 * to handle smaller (i.e. degraded) buffer allocations under low- or
1862 * fragmented-memory situations where such reduced allocations, from a
1863 * requested ideal, are allowed.
1865 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1867 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1869 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1870 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1873 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1875 while (*size > min_alloc) {
1876 kbuf = kmalloc(*size, flags);
1881 *size = ALIGN(*size, mtd->writesize);
1885 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1886 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1888 return kmalloc(*size, GFP_KERNEL);
1890 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1892 #ifdef CONFIG_PROC_FS
1894 /*====================================================================*/
1895 /* Support for /proc/mtd */
1897 static int mtd_proc_show(struct seq_file *m, void *v)
1899 struct mtd_info *mtd;
1901 seq_puts(m, "dev: size erasesize name\n");
1902 mutex_lock(&mtd_table_mutex);
1903 mtd_for_each_device(mtd) {
1904 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1905 mtd->index, (unsigned long long)mtd->size,
1906 mtd->erasesize, mtd->name);
1908 mutex_unlock(&mtd_table_mutex);
1911 #endif /* CONFIG_PROC_FS */
1913 /*====================================================================*/
1916 static struct backing_dev_info * __init mtd_bdi_init(char *name)
1918 struct backing_dev_info *bdi;
1921 bdi = bdi_alloc(GFP_KERNEL);
1923 return ERR_PTR(-ENOMEM);
1927 * We put '-0' suffix to the name to get the same name format as we
1928 * used to get. Since this is called only once, we get a unique name.
1930 ret = bdi_register(bdi, "%.28s-0", name);
1934 return ret ? ERR_PTR(ret) : bdi;
1937 static struct proc_dir_entry *proc_mtd;
1939 static int __init init_mtd(void)
1943 ret = class_register(&mtd_class);
1947 mtd_bdi = mtd_bdi_init("mtd");
1948 if (IS_ERR(mtd_bdi)) {
1949 ret = PTR_ERR(mtd_bdi);
1953 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
1955 ret = init_mtdchar();
1959 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
1965 remove_proc_entry("mtd", NULL);
1968 class_unregister(&mtd_class);
1970 pr_err("Error registering mtd class or bdi: %d\n", ret);
1974 static void __exit cleanup_mtd(void)
1976 debugfs_remove_recursive(dfs_dir_mtd);
1979 remove_proc_entry("mtd", NULL);
1980 class_unregister(&mtd_class);
1982 idr_destroy(&mtd_idr);
1985 module_init(init_mtd);
1986 module_exit(cleanup_mtd);
1988 MODULE_LICENSE("GPL");
1989 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1990 MODULE_DESCRIPTION("Core MTD registration and access routines");