1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Core registration and callback routines for MTD
6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
7 * Copyright © 2006 Red Hat UK Limited
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/ptrace.h>
13 #include <linux/seq_file.h>
14 #include <linux/string.h>
15 #include <linux/timer.h>
16 #include <linux/major.h>
18 #include <linux/err.h>
19 #include <linux/ioctl.h>
20 #include <linux/init.h>
22 #include <linux/proc_fs.h>
23 #include <linux/idr.h>
24 #include <linux/backing-dev.h>
25 #include <linux/gfp.h>
26 #include <linux/slab.h>
27 #include <linux/reboot.h>
28 #include <linux/leds.h>
29 #include <linux/debugfs.h>
30 #include <linux/nvmem-provider.h>
32 #include <linux/mtd/mtd.h>
33 #include <linux/mtd/partitions.h>
37 struct backing_dev_info *mtd_bdi;
39 #ifdef CONFIG_PM_SLEEP
41 static int mtd_cls_suspend(struct device *dev)
43 struct mtd_info *mtd = dev_get_drvdata(dev);
45 return mtd ? mtd_suspend(mtd) : 0;
48 static int mtd_cls_resume(struct device *dev)
50 struct mtd_info *mtd = dev_get_drvdata(dev);
57 static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
58 #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
60 #define MTD_CLS_PM_OPS NULL
63 static struct class mtd_class = {
69 static DEFINE_IDR(mtd_idr);
71 /* These are exported solely for the purpose of mtd_blkdevs.c. You
72 should not use them for _anything_ else */
73 DEFINE_MUTEX(mtd_table_mutex);
74 EXPORT_SYMBOL_GPL(mtd_table_mutex);
76 struct mtd_info *__mtd_next_device(int i)
78 return idr_get_next(&mtd_idr, &i);
80 EXPORT_SYMBOL_GPL(__mtd_next_device);
82 static LIST_HEAD(mtd_notifiers);
85 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
87 /* REVISIT once MTD uses the driver model better, whoever allocates
88 * the mtd_info will probably want to use the release() hook...
90 static void mtd_release(struct device *dev)
92 struct mtd_info *mtd = dev_get_drvdata(dev);
93 dev_t index = MTD_DEVT(mtd->index);
95 /* remove /dev/mtdXro node */
96 device_destroy(&mtd_class, index + 1);
99 static ssize_t mtd_type_show(struct device *dev,
100 struct device_attribute *attr, char *buf)
102 struct mtd_info *mtd = dev_get_drvdata(dev);
127 case MTD_MLCNANDFLASH:
134 return snprintf(buf, PAGE_SIZE, "%s\n", type);
136 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
138 static ssize_t mtd_flags_show(struct device *dev,
139 struct device_attribute *attr, char *buf)
141 struct mtd_info *mtd = dev_get_drvdata(dev);
143 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
145 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
147 static ssize_t mtd_size_show(struct device *dev,
148 struct device_attribute *attr, char *buf)
150 struct mtd_info *mtd = dev_get_drvdata(dev);
152 return snprintf(buf, PAGE_SIZE, "%llu\n",
153 (unsigned long long)mtd->size);
155 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
157 static ssize_t mtd_erasesize_show(struct device *dev,
158 struct device_attribute *attr, char *buf)
160 struct mtd_info *mtd = dev_get_drvdata(dev);
162 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
164 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
166 static ssize_t mtd_writesize_show(struct device *dev,
167 struct device_attribute *attr, char *buf)
169 struct mtd_info *mtd = dev_get_drvdata(dev);
171 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
173 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
175 static ssize_t mtd_subpagesize_show(struct device *dev,
176 struct device_attribute *attr, char *buf)
178 struct mtd_info *mtd = dev_get_drvdata(dev);
179 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
181 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
183 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
185 static ssize_t mtd_oobsize_show(struct device *dev,
186 struct device_attribute *attr, char *buf)
188 struct mtd_info *mtd = dev_get_drvdata(dev);
190 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
192 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
194 static ssize_t mtd_oobavail_show(struct device *dev,
195 struct device_attribute *attr, char *buf)
197 struct mtd_info *mtd = dev_get_drvdata(dev);
199 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->oobavail);
201 static DEVICE_ATTR(oobavail, S_IRUGO, mtd_oobavail_show, NULL);
203 static ssize_t mtd_numeraseregions_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, "%u\n", mtd->numeraseregions);
210 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
213 static ssize_t mtd_name_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, "%s\n", mtd->name);
220 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
222 static ssize_t mtd_ecc_strength_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
225 struct mtd_info *mtd = dev_get_drvdata(dev);
227 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
229 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
231 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
232 struct device_attribute *attr,
235 struct mtd_info *mtd = dev_get_drvdata(dev);
237 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
240 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
241 struct device_attribute *attr,
242 const char *buf, size_t count)
244 struct mtd_info *mtd = dev_get_drvdata(dev);
245 unsigned int bitflip_threshold;
248 retval = kstrtouint(buf, 0, &bitflip_threshold);
252 mtd->bitflip_threshold = bitflip_threshold;
255 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
256 mtd_bitflip_threshold_show,
257 mtd_bitflip_threshold_store);
259 static ssize_t mtd_ecc_step_size_show(struct device *dev,
260 struct device_attribute *attr, char *buf)
262 struct mtd_info *mtd = dev_get_drvdata(dev);
264 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
267 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
269 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
270 struct device_attribute *attr, char *buf)
272 struct mtd_info *mtd = dev_get_drvdata(dev);
273 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
275 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
277 static DEVICE_ATTR(corrected_bits, S_IRUGO,
278 mtd_ecc_stats_corrected_show, NULL);
280 static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
281 struct device_attribute *attr, char *buf)
283 struct mtd_info *mtd = dev_get_drvdata(dev);
284 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
286 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
288 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
290 static ssize_t mtd_badblocks_show(struct device *dev,
291 struct device_attribute *attr, char *buf)
293 struct mtd_info *mtd = dev_get_drvdata(dev);
294 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
296 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
298 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
300 static ssize_t mtd_bbtblocks_show(struct device *dev,
301 struct device_attribute *attr, char *buf)
303 struct mtd_info *mtd = dev_get_drvdata(dev);
304 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
306 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
308 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
310 static struct attribute *mtd_attrs[] = {
312 &dev_attr_flags.attr,
314 &dev_attr_erasesize.attr,
315 &dev_attr_writesize.attr,
316 &dev_attr_subpagesize.attr,
317 &dev_attr_oobsize.attr,
318 &dev_attr_oobavail.attr,
319 &dev_attr_numeraseregions.attr,
321 &dev_attr_ecc_strength.attr,
322 &dev_attr_ecc_step_size.attr,
323 &dev_attr_corrected_bits.attr,
324 &dev_attr_ecc_failures.attr,
325 &dev_attr_bad_blocks.attr,
326 &dev_attr_bbt_blocks.attr,
327 &dev_attr_bitflip_threshold.attr,
330 ATTRIBUTE_GROUPS(mtd);
332 static const struct device_type mtd_devtype = {
334 .groups = mtd_groups,
335 .release = mtd_release,
338 static int mtd_partid_show(struct seq_file *s, void *p)
340 struct mtd_info *mtd = s->private;
342 seq_printf(s, "%s\n", mtd->dbg.partid);
347 static int mtd_partid_debugfs_open(struct inode *inode, struct file *file)
349 return single_open(file, mtd_partid_show, inode->i_private);
352 static const struct file_operations mtd_partid_debug_fops = {
353 .open = mtd_partid_debugfs_open,
356 .release = single_release,
359 static int mtd_partname_show(struct seq_file *s, void *p)
361 struct mtd_info *mtd = s->private;
363 seq_printf(s, "%s\n", mtd->dbg.partname);
368 static int mtd_partname_debugfs_open(struct inode *inode, struct file *file)
370 return single_open(file, mtd_partname_show, inode->i_private);
373 static const struct file_operations mtd_partname_debug_fops = {
374 .open = mtd_partname_debugfs_open,
377 .release = single_release,
380 static struct dentry *dfs_dir_mtd;
382 static void mtd_debugfs_populate(struct mtd_info *mtd)
384 struct device *dev = &mtd->dev;
385 struct dentry *root, *dent;
387 if (IS_ERR_OR_NULL(dfs_dir_mtd))
390 root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
391 if (IS_ERR_OR_NULL(root)) {
392 dev_dbg(dev, "won't show data in debugfs\n");
396 mtd->dbg.dfs_dir = root;
398 if (mtd->dbg.partid) {
399 dent = debugfs_create_file("partid", 0400, root, mtd,
400 &mtd_partid_debug_fops);
401 if (IS_ERR_OR_NULL(dent))
402 dev_err(dev, "can't create debugfs entry for partid\n");
405 if (mtd->dbg.partname) {
406 dent = debugfs_create_file("partname", 0400, root, mtd,
407 &mtd_partname_debug_fops);
408 if (IS_ERR_OR_NULL(dent))
410 "can't create debugfs entry for partname\n");
415 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
419 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
420 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
422 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
425 return NOMMU_MAP_COPY;
428 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
431 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
434 struct mtd_info *mtd;
436 mtd = container_of(n, struct mtd_info, reboot_notifier);
443 * mtd_wunit_to_pairing_info - get pairing information of a wunit
444 * @mtd: pointer to new MTD device info structure
445 * @wunit: write unit we are interested in
446 * @info: returned pairing information
448 * Retrieve pairing information associated to the wunit.
449 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
450 * paired together, and where programming a page may influence the page it is
452 * The notion of page is replaced by the term wunit (write-unit) to stay
453 * consistent with the ->writesize field.
455 * The @wunit argument can be extracted from an absolute offset using
456 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
459 * From the pairing info the MTD user can find all the wunits paired with
460 * @wunit using the following loop:
462 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
464 * mtd_pairing_info_to_wunit(mtd, &info);
468 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
469 struct mtd_pairing_info *info)
471 int npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
473 if (wunit < 0 || wunit >= npairs)
476 if (mtd->pairing && mtd->pairing->get_info)
477 return mtd->pairing->get_info(mtd, wunit, info);
484 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
487 * mtd_pairing_info_to_wunit - get wunit from pairing information
488 * @mtd: pointer to new MTD device info structure
489 * @info: pairing information struct
491 * Returns a positive number representing the wunit associated to the info
492 * struct, or a negative error code.
494 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
495 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
498 * It can also be used to only program the first page of each pair (i.e.
499 * page attached to group 0), which allows one to use an MLC NAND in
500 * software-emulated SLC mode:
503 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
504 * for (info.pair = 0; info.pair < npairs; info.pair++) {
505 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
506 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
507 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
510 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
511 const struct mtd_pairing_info *info)
513 int ngroups = mtd_pairing_groups(mtd);
514 int npairs = mtd_wunit_per_eb(mtd) / ngroups;
516 if (!info || info->pair < 0 || info->pair >= npairs ||
517 info->group < 0 || info->group >= ngroups)
520 if (mtd->pairing && mtd->pairing->get_wunit)
521 return mtd->pairing->get_wunit(mtd, info);
525 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
528 * mtd_pairing_groups - get the number of pairing groups
529 * @mtd: pointer to new MTD device info structure
531 * Returns the number of pairing groups.
533 * This number is usually equal to the number of bits exposed by a single
534 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
535 * to iterate over all pages of a given pair.
537 int mtd_pairing_groups(struct mtd_info *mtd)
539 if (!mtd->pairing || !mtd->pairing->ngroups)
542 return mtd->pairing->ngroups;
544 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
546 static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
547 void *val, size_t bytes)
549 struct mtd_info *mtd = priv;
553 err = mtd_read(mtd, offset, bytes, &retlen, val);
554 if (err && err != -EUCLEAN)
557 return retlen == bytes ? 0 : -EIO;
560 static int mtd_nvmem_add(struct mtd_info *mtd)
562 struct nvmem_config config = {};
565 config.dev = &mtd->dev;
566 config.name = dev_name(&mtd->dev);
567 config.owner = THIS_MODULE;
568 config.reg_read = mtd_nvmem_reg_read;
569 config.size = mtd->size;
570 config.word_size = 1;
572 config.read_only = true;
573 config.root_only = true;
574 config.no_of_node = true;
577 mtd->nvmem = nvmem_register(&config);
578 if (IS_ERR(mtd->nvmem)) {
579 /* Just ignore if there is no NVMEM support in the kernel */
580 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
583 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
584 return PTR_ERR(mtd->nvmem);
592 * add_mtd_device - register an MTD device
593 * @mtd: pointer to new MTD device info structure
595 * Add a device to the list of MTD devices present in the system, and
596 * notify each currently active MTD 'user' of its arrival. Returns
597 * zero on success or non-zero on failure.
600 int add_mtd_device(struct mtd_info *mtd)
602 struct mtd_notifier *not;
606 * May occur, for instance, on buggy drivers which call
607 * mtd_device_parse_register() multiple times on the same master MTD,
608 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
610 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
613 BUG_ON(mtd->writesize == 0);
616 * MTD drivers should implement ->_{write,read}() or
617 * ->_{write,read}_oob(), but not both.
619 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
620 (mtd->_read && mtd->_read_oob)))
623 if (WARN_ON((!mtd->erasesize || !mtd->_erase) &&
624 !(mtd->flags & MTD_NO_ERASE)))
627 mutex_lock(&mtd_table_mutex);
629 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
638 /* default value if not set by driver */
639 if (mtd->bitflip_threshold == 0)
640 mtd->bitflip_threshold = mtd->ecc_strength;
642 if (is_power_of_2(mtd->erasesize))
643 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
645 mtd->erasesize_shift = 0;
647 if (is_power_of_2(mtd->writesize))
648 mtd->writesize_shift = ffs(mtd->writesize) - 1;
650 mtd->writesize_shift = 0;
652 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
653 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
655 /* Some chips always power up locked. Unlock them now */
656 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
657 error = mtd_unlock(mtd, 0, mtd->size);
658 if (error && error != -EOPNOTSUPP)
660 "%s: unlock failed, writes may not work\n",
662 /* Ignore unlock failures? */
666 /* Caller should have set dev.parent to match the
667 * physical device, if appropriate.
669 mtd->dev.type = &mtd_devtype;
670 mtd->dev.class = &mtd_class;
671 mtd->dev.devt = MTD_DEVT(i);
672 dev_set_name(&mtd->dev, "mtd%d", i);
673 dev_set_drvdata(&mtd->dev, mtd);
674 of_node_get(mtd_get_of_node(mtd));
675 error = device_register(&mtd->dev);
677 put_device(&mtd->dev);
681 /* Add the nvmem provider */
682 error = mtd_nvmem_add(mtd);
686 mtd_debugfs_populate(mtd);
688 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
691 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
692 /* No need to get a refcount on the module containing
693 the notifier, since we hold the mtd_table_mutex */
694 list_for_each_entry(not, &mtd_notifiers, list)
697 mutex_unlock(&mtd_table_mutex);
698 /* We _know_ we aren't being removed, because
699 our caller is still holding us here. So none
700 of this try_ nonsense, and no bitching about it
702 __module_get(THIS_MODULE);
706 device_unregister(&mtd->dev);
708 of_node_put(mtd_get_of_node(mtd));
709 idr_remove(&mtd_idr, i);
711 mutex_unlock(&mtd_table_mutex);
716 * del_mtd_device - unregister an MTD device
717 * @mtd: pointer to MTD device info structure
719 * Remove a device from the list of MTD devices present in the system,
720 * and notify each currently active MTD 'user' of its departure.
721 * Returns zero on success or 1 on failure, which currently will happen
722 * if the requested device does not appear to be present in the list.
725 int del_mtd_device(struct mtd_info *mtd)
728 struct mtd_notifier *not;
730 mutex_lock(&mtd_table_mutex);
732 if (idr_find(&mtd_idr, mtd->index) != mtd) {
737 /* No need to get a refcount on the module containing
738 the notifier, since we hold the mtd_table_mutex */
739 list_for_each_entry(not, &mtd_notifiers, list)
743 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
744 mtd->index, mtd->name, mtd->usecount);
747 debugfs_remove_recursive(mtd->dbg.dfs_dir);
749 /* Try to remove the NVMEM provider */
751 nvmem_unregister(mtd->nvmem);
753 device_unregister(&mtd->dev);
755 idr_remove(&mtd_idr, mtd->index);
756 of_node_put(mtd_get_of_node(mtd));
758 module_put(THIS_MODULE);
763 mutex_unlock(&mtd_table_mutex);
768 * Set a few defaults based on the parent devices, if not provided by the
771 static void mtd_set_dev_defaults(struct mtd_info *mtd)
773 if (mtd->dev.parent) {
774 if (!mtd->owner && mtd->dev.parent->driver)
775 mtd->owner = mtd->dev.parent->driver->owner;
777 mtd->name = dev_name(mtd->dev.parent);
779 pr_debug("mtd device won't show a device symlink in sysfs\n");
782 mtd->orig_flags = mtd->flags;
786 * mtd_device_parse_register - parse partitions and register an MTD device.
788 * @mtd: the MTD device to register
789 * @types: the list of MTD partition probes to try, see
790 * 'parse_mtd_partitions()' for more information
791 * @parser_data: MTD partition parser-specific data
792 * @parts: fallback partition information to register, if parsing fails;
793 * only valid if %nr_parts > %0
794 * @nr_parts: the number of partitions in parts, if zero then the full
795 * MTD device is registered if no partition info is found
797 * This function aggregates MTD partitions parsing (done by
798 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
799 * basically follows the most common pattern found in many MTD drivers:
801 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
803 * * Then It tries to probe partitions on MTD device @mtd using parsers
804 * specified in @types (if @types is %NULL, then the default list of parsers
805 * is used, see 'parse_mtd_partitions()' for more information). If none are
806 * found this functions tries to fallback to information specified in
808 * * If no partitions were found this function just registers the MTD device
811 * Returns zero in case of success and a negative error code in case of failure.
813 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
814 struct mtd_part_parser_data *parser_data,
815 const struct mtd_partition *parts,
820 mtd_set_dev_defaults(mtd);
822 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
823 ret = add_mtd_device(mtd);
828 /* Prefer parsed partitions over driver-provided fallback */
829 ret = parse_mtd_partitions(mtd, types, parser_data);
830 if (ret == -EPROBE_DEFER)
836 ret = add_mtd_partitions(mtd, parts, nr_parts);
837 else if (!device_is_registered(&mtd->dev))
838 ret = add_mtd_device(mtd);
846 * FIXME: some drivers unfortunately call this function more than once.
847 * So we have to check if we've already assigned the reboot notifier.
849 * Generally, we can make multiple calls work for most cases, but it
850 * does cause problems with parse_mtd_partitions() above (e.g.,
851 * cmdlineparts will register partitions more than once).
853 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
854 "MTD already registered\n");
855 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
856 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
857 register_reboot_notifier(&mtd->reboot_notifier);
861 if (ret && device_is_registered(&mtd->dev))
866 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
869 * mtd_device_unregister - unregister an existing MTD device.
871 * @master: the MTD device to unregister. This will unregister both the master
872 * and any partitions if registered.
874 int mtd_device_unregister(struct mtd_info *master)
879 unregister_reboot_notifier(&master->reboot_notifier);
881 err = del_mtd_partitions(master);
885 if (!device_is_registered(&master->dev))
888 return del_mtd_device(master);
890 EXPORT_SYMBOL_GPL(mtd_device_unregister);
893 * register_mtd_user - register a 'user' of MTD devices.
894 * @new: pointer to notifier info structure
896 * Registers a pair of callbacks function to be called upon addition
897 * or removal of MTD devices. Causes the 'add' callback to be immediately
898 * invoked for each MTD device currently present in the system.
900 void register_mtd_user (struct mtd_notifier *new)
902 struct mtd_info *mtd;
904 mutex_lock(&mtd_table_mutex);
906 list_add(&new->list, &mtd_notifiers);
908 __module_get(THIS_MODULE);
910 mtd_for_each_device(mtd)
913 mutex_unlock(&mtd_table_mutex);
915 EXPORT_SYMBOL_GPL(register_mtd_user);
918 * unregister_mtd_user - unregister a 'user' of MTD devices.
919 * @old: pointer to notifier info structure
921 * Removes a callback function pair from the list of 'users' to be
922 * notified upon addition or removal of MTD devices. Causes the
923 * 'remove' callback to be immediately invoked for each MTD device
924 * currently present in the system.
926 int unregister_mtd_user (struct mtd_notifier *old)
928 struct mtd_info *mtd;
930 mutex_lock(&mtd_table_mutex);
932 module_put(THIS_MODULE);
934 mtd_for_each_device(mtd)
937 list_del(&old->list);
938 mutex_unlock(&mtd_table_mutex);
941 EXPORT_SYMBOL_GPL(unregister_mtd_user);
944 * get_mtd_device - obtain a validated handle for an MTD device
945 * @mtd: last known address of the required MTD device
946 * @num: internal device number of the required MTD device
948 * Given a number and NULL address, return the num'th entry in the device
949 * table, if any. Given an address and num == -1, search the device table
950 * for a device with that address and return if it's still present. Given
951 * both, return the num'th driver only if its address matches. Return
954 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
956 struct mtd_info *ret = NULL, *other;
959 mutex_lock(&mtd_table_mutex);
962 mtd_for_each_device(other) {
968 } else if (num >= 0) {
969 ret = idr_find(&mtd_idr, num);
970 if (mtd && mtd != ret)
979 err = __get_mtd_device(ret);
983 mutex_unlock(&mtd_table_mutex);
986 EXPORT_SYMBOL_GPL(get_mtd_device);
989 int __get_mtd_device(struct mtd_info *mtd)
993 if (!try_module_get(mtd->owner))
996 if (mtd->_get_device) {
997 err = mtd->_get_device(mtd);
1000 module_put(mtd->owner);
1007 EXPORT_SYMBOL_GPL(__get_mtd_device);
1010 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1012 * @name: MTD device name to open
1014 * This function returns MTD device description structure in case of
1015 * success and an error code in case of failure.
1017 struct mtd_info *get_mtd_device_nm(const char *name)
1020 struct mtd_info *mtd = NULL, *other;
1022 mutex_lock(&mtd_table_mutex);
1024 mtd_for_each_device(other) {
1025 if (!strcmp(name, other->name)) {
1034 err = __get_mtd_device(mtd);
1038 mutex_unlock(&mtd_table_mutex);
1042 mutex_unlock(&mtd_table_mutex);
1043 return ERR_PTR(err);
1045 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1047 void put_mtd_device(struct mtd_info *mtd)
1049 mutex_lock(&mtd_table_mutex);
1050 __put_mtd_device(mtd);
1051 mutex_unlock(&mtd_table_mutex);
1054 EXPORT_SYMBOL_GPL(put_mtd_device);
1056 void __put_mtd_device(struct mtd_info *mtd)
1059 BUG_ON(mtd->usecount < 0);
1061 if (mtd->_put_device)
1062 mtd->_put_device(mtd);
1064 module_put(mtd->owner);
1066 EXPORT_SYMBOL_GPL(__put_mtd_device);
1069 * Erase is an synchronous operation. Device drivers are epected to return a
1070 * negative error code if the operation failed and update instr->fail_addr
1071 * to point the portion that was not properly erased.
1073 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1075 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1077 if (!mtd->erasesize || !mtd->_erase)
1080 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1082 if (!(mtd->flags & MTD_WRITEABLE))
1088 ledtrig_mtd_activity();
1089 return mtd->_erase(mtd, instr);
1091 EXPORT_SYMBOL_GPL(mtd_erase);
1094 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1096 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1097 void **virt, resource_size_t *phys)
1105 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1109 return mtd->_point(mtd, from, len, retlen, virt, phys);
1111 EXPORT_SYMBOL_GPL(mtd_point);
1113 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1114 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1118 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1122 return mtd->_unpoint(mtd, from, len);
1124 EXPORT_SYMBOL_GPL(mtd_unpoint);
1127 * Allow NOMMU mmap() to directly map the device (if not NULL)
1128 * - return the address to which the offset maps
1129 * - return -ENOSYS to indicate refusal to do the mapping
1131 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1132 unsigned long offset, unsigned long flags)
1138 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1141 if (retlen != len) {
1142 mtd_unpoint(mtd, offset, retlen);
1145 return (unsigned long)virt;
1147 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1149 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1152 struct mtd_oob_ops ops = {
1158 ret = mtd_read_oob(mtd, from, &ops);
1159 *retlen = ops.retlen;
1163 EXPORT_SYMBOL_GPL(mtd_read);
1165 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1168 struct mtd_oob_ops ops = {
1170 .datbuf = (u8 *)buf,
1174 ret = mtd_write_oob(mtd, to, &ops);
1175 *retlen = ops.retlen;
1179 EXPORT_SYMBOL_GPL(mtd_write);
1182 * In blackbox flight recorder like scenarios we want to make successful writes
1183 * in interrupt context. panic_write() is only intended to be called when its
1184 * known the kernel is about to panic and we need the write to succeed. Since
1185 * the kernel is not going to be running for much longer, this function can
1186 * break locks and delay to ensure the write succeeds (but not sleep).
1188 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1192 if (!mtd->_panic_write)
1194 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1196 if (!(mtd->flags & MTD_WRITEABLE))
1200 if (!mtd->oops_panic_write)
1201 mtd->oops_panic_write = true;
1203 return mtd->_panic_write(mtd, to, len, retlen, buf);
1205 EXPORT_SYMBOL_GPL(mtd_panic_write);
1207 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1208 struct mtd_oob_ops *ops)
1211 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1212 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1221 if (offs < 0 || offs + ops->len > mtd->size)
1227 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1230 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1231 mtd_div_by_ws(offs, mtd)) *
1232 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1233 if (ops->ooblen > maxooblen)
1240 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1243 ops->retlen = ops->oobretlen = 0;
1245 ret_code = mtd_check_oob_ops(mtd, from, ops);
1249 ledtrig_mtd_activity();
1251 /* Check the validity of a potential fallback on mtd->_read */
1252 if (!mtd->_read_oob && (!mtd->_read || ops->oobbuf))
1256 ret_code = mtd->_read_oob(mtd, from, ops);
1258 ret_code = mtd->_read(mtd, from, ops->len, &ops->retlen,
1262 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1263 * similar to mtd->_read(), returning a non-negative integer
1264 * representing max bitflips. In other cases, mtd->_read_oob() may
1265 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1267 if (unlikely(ret_code < 0))
1269 if (mtd->ecc_strength == 0)
1270 return 0; /* device lacks ecc */
1271 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1273 EXPORT_SYMBOL_GPL(mtd_read_oob);
1275 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1276 struct mtd_oob_ops *ops)
1280 ops->retlen = ops->oobretlen = 0;
1282 if (!(mtd->flags & MTD_WRITEABLE))
1285 ret = mtd_check_oob_ops(mtd, to, ops);
1289 ledtrig_mtd_activity();
1291 /* Check the validity of a potential fallback on mtd->_write */
1292 if (!mtd->_write_oob && (!mtd->_write || ops->oobbuf))
1295 if (mtd->_write_oob)
1296 return mtd->_write_oob(mtd, to, ops);
1298 return mtd->_write(mtd, to, ops->len, &ops->retlen,
1301 EXPORT_SYMBOL_GPL(mtd_write_oob);
1304 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1305 * @mtd: MTD device structure
1306 * @section: ECC section. Depending on the layout you may have all the ECC
1307 * bytes stored in a single contiguous section, or one section
1308 * per ECC chunk (and sometime several sections for a single ECC
1310 * @oobecc: OOB region struct filled with the appropriate ECC position
1313 * This function returns ECC section information in the OOB area. If you want
1314 * to get all the ECC bytes information, then you should call
1315 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1317 * Returns zero on success, a negative error code otherwise.
1319 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1320 struct mtd_oob_region *oobecc)
1322 memset(oobecc, 0, sizeof(*oobecc));
1324 if (!mtd || section < 0)
1327 if (!mtd->ooblayout || !mtd->ooblayout->ecc)
1330 return mtd->ooblayout->ecc(mtd, section, oobecc);
1332 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1335 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1337 * @mtd: MTD device structure
1338 * @section: Free section you are interested in. Depending on the layout
1339 * you may have all the free bytes stored in a single contiguous
1340 * section, or one section per ECC chunk plus an extra section
1341 * for the remaining bytes (or other funky layout).
1342 * @oobfree: OOB region struct filled with the appropriate free position
1345 * This function returns free bytes position in the OOB area. If you want
1346 * to get all the free bytes information, then you should call
1347 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1349 * Returns zero on success, a negative error code otherwise.
1351 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1352 struct mtd_oob_region *oobfree)
1354 memset(oobfree, 0, sizeof(*oobfree));
1356 if (!mtd || section < 0)
1359 if (!mtd->ooblayout || !mtd->ooblayout->free)
1362 return mtd->ooblayout->free(mtd, section, oobfree);
1364 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1367 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1368 * @mtd: mtd info structure
1369 * @byte: the byte we are searching for
1370 * @sectionp: pointer where the section id will be stored
1371 * @oobregion: used to retrieve the ECC position
1372 * @iter: iterator function. Should be either mtd_ooblayout_free or
1373 * mtd_ooblayout_ecc depending on the region type you're searching for
1375 * This function returns the section id and oobregion information of a
1376 * specific byte. For example, say you want to know where the 4th ECC byte is
1377 * stored, you'll use:
1379 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1381 * Returns zero on success, a negative error code otherwise.
1383 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1384 int *sectionp, struct mtd_oob_region *oobregion,
1385 int (*iter)(struct mtd_info *,
1387 struct mtd_oob_region *oobregion))
1389 int pos = 0, ret, section = 0;
1391 memset(oobregion, 0, sizeof(*oobregion));
1394 ret = iter(mtd, section, oobregion);
1398 if (pos + oobregion->length > byte)
1401 pos += oobregion->length;
1406 * Adjust region info to make it start at the beginning at the
1409 oobregion->offset += byte - pos;
1410 oobregion->length -= byte - pos;
1411 *sectionp = section;
1417 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1419 * @mtd: mtd info structure
1420 * @eccbyte: the byte we are searching for
1421 * @sectionp: pointer where the section id will be stored
1422 * @oobregion: OOB region information
1424 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1427 * Returns zero on success, a negative error code otherwise.
1429 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1431 struct mtd_oob_region *oobregion)
1433 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1436 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1439 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1440 * @mtd: mtd info structure
1441 * @buf: destination buffer to store OOB bytes
1442 * @oobbuf: OOB buffer
1443 * @start: first byte to retrieve
1444 * @nbytes: number of bytes to retrieve
1445 * @iter: section iterator
1447 * Extract bytes attached to a specific category (ECC or free)
1448 * from the OOB buffer and copy them into buf.
1450 * Returns zero on success, a negative error code otherwise.
1452 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1453 const u8 *oobbuf, int start, int nbytes,
1454 int (*iter)(struct mtd_info *,
1456 struct mtd_oob_region *oobregion))
1458 struct mtd_oob_region oobregion;
1461 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1467 cnt = min_t(int, nbytes, oobregion.length);
1468 memcpy(buf, oobbuf + oobregion.offset, cnt);
1475 ret = iter(mtd, ++section, &oobregion);
1482 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1483 * @mtd: mtd info structure
1484 * @buf: source buffer to get OOB bytes from
1485 * @oobbuf: OOB buffer
1486 * @start: first OOB byte to set
1487 * @nbytes: number of OOB bytes to set
1488 * @iter: section iterator
1490 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1491 * is selected by passing the appropriate iterator.
1493 * Returns zero on success, a negative error code otherwise.
1495 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1496 u8 *oobbuf, int start, int nbytes,
1497 int (*iter)(struct mtd_info *,
1499 struct mtd_oob_region *oobregion))
1501 struct mtd_oob_region oobregion;
1504 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1510 cnt = min_t(int, nbytes, oobregion.length);
1511 memcpy(oobbuf + oobregion.offset, buf, cnt);
1518 ret = iter(mtd, ++section, &oobregion);
1525 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1526 * @mtd: mtd info structure
1527 * @iter: category iterator
1529 * Count the number of bytes in a given category.
1531 * Returns a positive value on success, a negative error code otherwise.
1533 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1534 int (*iter)(struct mtd_info *,
1536 struct mtd_oob_region *oobregion))
1538 struct mtd_oob_region oobregion;
1539 int section = 0, ret, nbytes = 0;
1542 ret = iter(mtd, section++, &oobregion);
1549 nbytes += oobregion.length;
1556 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1557 * @mtd: mtd info structure
1558 * @eccbuf: destination buffer to store ECC bytes
1559 * @oobbuf: OOB buffer
1560 * @start: first ECC byte to retrieve
1561 * @nbytes: number of ECC bytes to retrieve
1563 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1565 * Returns zero on success, a negative error code otherwise.
1567 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1568 const u8 *oobbuf, int start, int nbytes)
1570 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1573 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1576 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1577 * @mtd: mtd info structure
1578 * @eccbuf: source buffer to get ECC bytes from
1579 * @oobbuf: OOB buffer
1580 * @start: first ECC byte to set
1581 * @nbytes: number of ECC bytes to set
1583 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1585 * Returns zero on success, a negative error code otherwise.
1587 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1588 u8 *oobbuf, int start, int nbytes)
1590 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1593 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1596 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1597 * @mtd: mtd info structure
1598 * @databuf: destination buffer to store ECC bytes
1599 * @oobbuf: OOB buffer
1600 * @start: first ECC byte to retrieve
1601 * @nbytes: number of ECC bytes to retrieve
1603 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1605 * Returns zero on success, a negative error code otherwise.
1607 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1608 const u8 *oobbuf, int start, int nbytes)
1610 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1611 mtd_ooblayout_free);
1613 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1616 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1617 * @mtd: mtd info structure
1618 * @databuf: source buffer to get data bytes from
1619 * @oobbuf: OOB buffer
1620 * @start: first ECC byte to set
1621 * @nbytes: number of ECC bytes to set
1623 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1625 * Returns zero on success, a negative error code otherwise.
1627 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1628 u8 *oobbuf, int start, int nbytes)
1630 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1631 mtd_ooblayout_free);
1633 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1636 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1637 * @mtd: mtd info structure
1639 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1641 * Returns zero on success, a negative error code otherwise.
1643 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1645 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1647 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1650 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1651 * @mtd: mtd info structure
1653 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1655 * Returns zero on success, a negative error code otherwise.
1657 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1659 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1661 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1664 * Method to access the protection register area, present in some flash
1665 * devices. The user data is one time programmable but the factory data is read
1668 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1669 struct otp_info *buf)
1671 if (!mtd->_get_fact_prot_info)
1675 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1677 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1679 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1680 size_t *retlen, u_char *buf)
1683 if (!mtd->_read_fact_prot_reg)
1687 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1689 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1691 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1692 struct otp_info *buf)
1694 if (!mtd->_get_user_prot_info)
1698 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1700 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1702 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1703 size_t *retlen, u_char *buf)
1706 if (!mtd->_read_user_prot_reg)
1710 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1712 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1714 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1715 size_t *retlen, u_char *buf)
1720 if (!mtd->_write_user_prot_reg)
1724 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1729 * If no data could be written at all, we are out of memory and
1730 * must return -ENOSPC.
1732 return (*retlen) ? 0 : -ENOSPC;
1734 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1736 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1738 if (!mtd->_lock_user_prot_reg)
1742 return mtd->_lock_user_prot_reg(mtd, from, len);
1744 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1746 /* Chip-supported device locking */
1747 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1751 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1755 return mtd->_lock(mtd, ofs, len);
1757 EXPORT_SYMBOL_GPL(mtd_lock);
1759 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1763 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1767 return mtd->_unlock(mtd, ofs, len);
1769 EXPORT_SYMBOL_GPL(mtd_unlock);
1771 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1773 if (!mtd->_is_locked)
1775 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1779 return mtd->_is_locked(mtd, ofs, len);
1781 EXPORT_SYMBOL_GPL(mtd_is_locked);
1783 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1785 if (ofs < 0 || ofs >= mtd->size)
1787 if (!mtd->_block_isreserved)
1789 return mtd->_block_isreserved(mtd, ofs);
1791 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1793 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1795 if (ofs < 0 || ofs >= mtd->size)
1797 if (!mtd->_block_isbad)
1799 return mtd->_block_isbad(mtd, ofs);
1801 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1803 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1805 if (!mtd->_block_markbad)
1807 if (ofs < 0 || ofs >= mtd->size)
1809 if (!(mtd->flags & MTD_WRITEABLE))
1811 return mtd->_block_markbad(mtd, ofs);
1813 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1816 * default_mtd_writev - the default writev method
1817 * @mtd: mtd device description object pointer
1818 * @vecs: the vectors to write
1819 * @count: count of vectors in @vecs
1820 * @to: the MTD device offset to write to
1821 * @retlen: on exit contains the count of bytes written to the MTD device.
1823 * This function returns zero in case of success and a negative error code in
1826 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1827 unsigned long count, loff_t to, size_t *retlen)
1830 size_t totlen = 0, thislen;
1833 for (i = 0; i < count; i++) {
1834 if (!vecs[i].iov_len)
1836 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1839 if (ret || thislen != vecs[i].iov_len)
1841 to += vecs[i].iov_len;
1848 * mtd_writev - the vector-based MTD write method
1849 * @mtd: mtd device description object pointer
1850 * @vecs: the vectors to write
1851 * @count: count of vectors in @vecs
1852 * @to: the MTD device offset to write to
1853 * @retlen: on exit contains the count of bytes written to the MTD device.
1855 * This function returns zero in case of success and a negative error code in
1858 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1859 unsigned long count, loff_t to, size_t *retlen)
1862 if (!(mtd->flags & MTD_WRITEABLE))
1865 return default_mtd_writev(mtd, vecs, count, to, retlen);
1866 return mtd->_writev(mtd, vecs, count, to, retlen);
1868 EXPORT_SYMBOL_GPL(mtd_writev);
1871 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1872 * @mtd: mtd device description object pointer
1873 * @size: a pointer to the ideal or maximum size of the allocation, points
1874 * to the actual allocation size on success.
1876 * This routine attempts to allocate a contiguous kernel buffer up to
1877 * the specified size, backing off the size of the request exponentially
1878 * until the request succeeds or until the allocation size falls below
1879 * the system page size. This attempts to make sure it does not adversely
1880 * impact system performance, so when allocating more than one page, we
1881 * ask the memory allocator to avoid re-trying, swapping, writing back
1882 * or performing I/O.
1884 * Note, this function also makes sure that the allocated buffer is aligned to
1885 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1887 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1888 * to handle smaller (i.e. degraded) buffer allocations under low- or
1889 * fragmented-memory situations where such reduced allocations, from a
1890 * requested ideal, are allowed.
1892 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1894 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1896 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1897 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1900 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1902 while (*size > min_alloc) {
1903 kbuf = kmalloc(*size, flags);
1908 *size = ALIGN(*size, mtd->writesize);
1912 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1913 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1915 return kmalloc(*size, GFP_KERNEL);
1917 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1919 #ifdef CONFIG_PROC_FS
1921 /*====================================================================*/
1922 /* Support for /proc/mtd */
1924 static int mtd_proc_show(struct seq_file *m, void *v)
1926 struct mtd_info *mtd;
1928 seq_puts(m, "dev: size erasesize name\n");
1929 mutex_lock(&mtd_table_mutex);
1930 mtd_for_each_device(mtd) {
1931 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1932 mtd->index, (unsigned long long)mtd->size,
1933 mtd->erasesize, mtd->name);
1935 mutex_unlock(&mtd_table_mutex);
1938 #endif /* CONFIG_PROC_FS */
1940 /*====================================================================*/
1943 static struct backing_dev_info * __init mtd_bdi_init(char *name)
1945 struct backing_dev_info *bdi;
1948 bdi = bdi_alloc(GFP_KERNEL);
1950 return ERR_PTR(-ENOMEM);
1954 * We put '-0' suffix to the name to get the same name format as we
1955 * used to get. Since this is called only once, we get a unique name.
1957 ret = bdi_register(bdi, "%.28s-0", name);
1961 return ret ? ERR_PTR(ret) : bdi;
1964 static struct proc_dir_entry *proc_mtd;
1966 static int __init init_mtd(void)
1970 ret = class_register(&mtd_class);
1974 mtd_bdi = mtd_bdi_init("mtd");
1975 if (IS_ERR(mtd_bdi)) {
1976 ret = PTR_ERR(mtd_bdi);
1980 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
1982 ret = init_mtdchar();
1986 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
1992 remove_proc_entry("mtd", NULL);
1995 class_unregister(&mtd_class);
1997 pr_err("Error registering mtd class or bdi: %d\n", ret);
2001 static void __exit cleanup_mtd(void)
2003 debugfs_remove_recursive(dfs_dir_mtd);
2006 remove_proc_entry("mtd", NULL);
2007 class_unregister(&mtd_class);
2009 idr_destroy(&mtd_idr);
2012 module_init(init_mtd);
2013 module_exit(cleanup_mtd);
2015 MODULE_LICENSE("GPL");
2016 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2017 MODULE_DESCRIPTION("Core MTD registration and access routines");