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;
387 if (IS_ERR_OR_NULL(dfs_dir_mtd))
390 root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
391 mtd->dbg.dfs_dir = root;
394 debugfs_create_file("partid", 0400, root, mtd,
395 &mtd_partid_debug_fops);
397 if (mtd->dbg.partname)
398 debugfs_create_file("partname", 0400, root, mtd,
399 &mtd_partname_debug_fops);
403 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
407 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
408 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
410 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
413 return NOMMU_MAP_COPY;
416 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
419 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
422 struct mtd_info *mtd;
424 mtd = container_of(n, struct mtd_info, reboot_notifier);
431 * mtd_wunit_to_pairing_info - get pairing information of a wunit
432 * @mtd: pointer to new MTD device info structure
433 * @wunit: write unit we are interested in
434 * @info: returned pairing information
436 * Retrieve pairing information associated to the wunit.
437 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
438 * paired together, and where programming a page may influence the page it is
440 * The notion of page is replaced by the term wunit (write-unit) to stay
441 * consistent with the ->writesize field.
443 * The @wunit argument can be extracted from an absolute offset using
444 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
447 * From the pairing info the MTD user can find all the wunits paired with
448 * @wunit using the following loop:
450 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
452 * mtd_pairing_info_to_wunit(mtd, &info);
456 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
457 struct mtd_pairing_info *info)
459 struct mtd_info *master = mtd_get_master(mtd);
460 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
462 if (wunit < 0 || wunit >= npairs)
465 if (master->pairing && master->pairing->get_info)
466 return master->pairing->get_info(master, wunit, info);
473 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
476 * mtd_pairing_info_to_wunit - get wunit from pairing information
477 * @mtd: pointer to new MTD device info structure
478 * @info: pairing information struct
480 * Returns a positive number representing the wunit associated to the info
481 * struct, or a negative error code.
483 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
484 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
487 * It can also be used to only program the first page of each pair (i.e.
488 * page attached to group 0), which allows one to use an MLC NAND in
489 * software-emulated SLC mode:
492 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
493 * for (info.pair = 0; info.pair < npairs; info.pair++) {
494 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
495 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
496 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
499 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
500 const struct mtd_pairing_info *info)
502 struct mtd_info *master = mtd_get_master(mtd);
503 int ngroups = mtd_pairing_groups(master);
504 int npairs = mtd_wunit_per_eb(master) / ngroups;
506 if (!info || info->pair < 0 || info->pair >= npairs ||
507 info->group < 0 || info->group >= ngroups)
510 if (master->pairing && master->pairing->get_wunit)
511 return mtd->pairing->get_wunit(master, info);
515 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
518 * mtd_pairing_groups - get the number of pairing groups
519 * @mtd: pointer to new MTD device info structure
521 * Returns the number of pairing groups.
523 * This number is usually equal to the number of bits exposed by a single
524 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
525 * to iterate over all pages of a given pair.
527 int mtd_pairing_groups(struct mtd_info *mtd)
529 struct mtd_info *master = mtd_get_master(mtd);
531 if (!master->pairing || !master->pairing->ngroups)
534 return master->pairing->ngroups;
536 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
538 static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
539 void *val, size_t bytes)
541 struct mtd_info *mtd = priv;
545 err = mtd_read(mtd, offset, bytes, &retlen, val);
546 if (err && err != -EUCLEAN)
549 return retlen == bytes ? 0 : -EIO;
552 static int mtd_nvmem_add(struct mtd_info *mtd)
554 struct nvmem_config config = {};
557 config.dev = &mtd->dev;
558 config.name = mtd->name;
559 config.owner = THIS_MODULE;
560 config.reg_read = mtd_nvmem_reg_read;
561 config.size = mtd->size;
562 config.word_size = 1;
564 config.read_only = true;
565 config.root_only = true;
566 config.no_of_node = true;
569 mtd->nvmem = nvmem_register(&config);
570 if (IS_ERR(mtd->nvmem)) {
571 /* Just ignore if there is no NVMEM support in the kernel */
572 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
575 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
576 return PTR_ERR(mtd->nvmem);
584 * add_mtd_device - register an MTD device
585 * @mtd: pointer to new MTD device info structure
587 * Add a device to the list of MTD devices present in the system, and
588 * notify each currently active MTD 'user' of its arrival. Returns
589 * zero on success or non-zero on failure.
592 int add_mtd_device(struct mtd_info *mtd)
594 struct mtd_info *master = mtd_get_master(mtd);
595 struct mtd_notifier *not;
599 * May occur, for instance, on buggy drivers which call
600 * mtd_device_parse_register() multiple times on the same master MTD,
601 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
603 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
606 BUG_ON(mtd->writesize == 0);
609 * MTD drivers should implement ->_{write,read}() or
610 * ->_{write,read}_oob(), but not both.
612 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
613 (mtd->_read && mtd->_read_oob)))
616 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
617 !(mtd->flags & MTD_NO_ERASE)))
620 mutex_lock(&mtd_table_mutex);
622 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
631 /* default value if not set by driver */
632 if (mtd->bitflip_threshold == 0)
633 mtd->bitflip_threshold = mtd->ecc_strength;
635 if (is_power_of_2(mtd->erasesize))
636 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
638 mtd->erasesize_shift = 0;
640 if (is_power_of_2(mtd->writesize))
641 mtd->writesize_shift = ffs(mtd->writesize) - 1;
643 mtd->writesize_shift = 0;
645 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
646 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
648 /* Some chips always power up locked. Unlock them now */
649 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
650 error = mtd_unlock(mtd, 0, mtd->size);
651 if (error && error != -EOPNOTSUPP)
653 "%s: unlock failed, writes may not work\n",
655 /* Ignore unlock failures? */
659 /* Caller should have set dev.parent to match the
660 * physical device, if appropriate.
662 mtd->dev.type = &mtd_devtype;
663 mtd->dev.class = &mtd_class;
664 mtd->dev.devt = MTD_DEVT(i);
665 dev_set_name(&mtd->dev, "mtd%d", i);
666 dev_set_drvdata(&mtd->dev, mtd);
667 of_node_get(mtd_get_of_node(mtd));
668 error = device_register(&mtd->dev);
672 /* Add the nvmem provider */
673 error = mtd_nvmem_add(mtd);
677 mtd_debugfs_populate(mtd);
679 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
682 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
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)
688 mutex_unlock(&mtd_table_mutex);
689 /* We _know_ we aren't being removed, because
690 our caller is still holding us here. So none
691 of this try_ nonsense, and no bitching about it
693 __module_get(THIS_MODULE);
697 device_unregister(&mtd->dev);
699 of_node_put(mtd_get_of_node(mtd));
700 idr_remove(&mtd_idr, i);
702 mutex_unlock(&mtd_table_mutex);
707 * del_mtd_device - unregister an MTD device
708 * @mtd: pointer to MTD device info structure
710 * Remove a device from the list of MTD devices present in the system,
711 * and notify each currently active MTD 'user' of its departure.
712 * Returns zero on success or 1 on failure, which currently will happen
713 * if the requested device does not appear to be present in the list.
716 int del_mtd_device(struct mtd_info *mtd)
719 struct mtd_notifier *not;
721 mutex_lock(&mtd_table_mutex);
723 debugfs_remove_recursive(mtd->dbg.dfs_dir);
725 if (idr_find(&mtd_idr, mtd->index) != mtd) {
730 /* No need to get a refcount on the module containing
731 the notifier, since we hold the mtd_table_mutex */
732 list_for_each_entry(not, &mtd_notifiers, list)
736 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
737 mtd->index, mtd->name, mtd->usecount);
740 /* Try to remove the NVMEM provider */
742 nvmem_unregister(mtd->nvmem);
744 device_unregister(&mtd->dev);
746 idr_remove(&mtd_idr, mtd->index);
747 of_node_put(mtd_get_of_node(mtd));
749 module_put(THIS_MODULE);
754 mutex_unlock(&mtd_table_mutex);
759 * Set a few defaults based on the parent devices, if not provided by the
762 static void mtd_set_dev_defaults(struct mtd_info *mtd)
764 if (mtd->dev.parent) {
765 if (!mtd->owner && mtd->dev.parent->driver)
766 mtd->owner = mtd->dev.parent->driver->owner;
768 mtd->name = dev_name(mtd->dev.parent);
770 pr_debug("mtd device won't show a device symlink in sysfs\n");
773 INIT_LIST_HEAD(&mtd->partitions);
774 mutex_init(&mtd->master.partitions_lock);
778 * mtd_device_parse_register - parse partitions and register an MTD device.
780 * @mtd: the MTD device to register
781 * @types: the list of MTD partition probes to try, see
782 * 'parse_mtd_partitions()' for more information
783 * @parser_data: MTD partition parser-specific data
784 * @parts: fallback partition information to register, if parsing fails;
785 * only valid if %nr_parts > %0
786 * @nr_parts: the number of partitions in parts, if zero then the full
787 * MTD device is registered if no partition info is found
789 * This function aggregates MTD partitions parsing (done by
790 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
791 * basically follows the most common pattern found in many MTD drivers:
793 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
795 * * Then It tries to probe partitions on MTD device @mtd using parsers
796 * specified in @types (if @types is %NULL, then the default list of parsers
797 * is used, see 'parse_mtd_partitions()' for more information). If none are
798 * found this functions tries to fallback to information specified in
800 * * If no partitions were found this function just registers the MTD device
803 * Returns zero in case of success and a negative error code in case of failure.
805 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
806 struct mtd_part_parser_data *parser_data,
807 const struct mtd_partition *parts,
812 mtd_set_dev_defaults(mtd);
814 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
815 ret = add_mtd_device(mtd);
820 /* Prefer parsed partitions over driver-provided fallback */
821 ret = parse_mtd_partitions(mtd, types, parser_data);
825 ret = add_mtd_partitions(mtd, parts, nr_parts);
826 else if (!device_is_registered(&mtd->dev))
827 ret = add_mtd_device(mtd);
835 * FIXME: some drivers unfortunately call this function more than once.
836 * So we have to check if we've already assigned the reboot notifier.
838 * Generally, we can make multiple calls work for most cases, but it
839 * does cause problems with parse_mtd_partitions() above (e.g.,
840 * cmdlineparts will register partitions more than once).
842 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
843 "MTD already registered\n");
844 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
845 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
846 register_reboot_notifier(&mtd->reboot_notifier);
850 if (ret && device_is_registered(&mtd->dev))
855 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
858 * mtd_device_unregister - unregister an existing MTD device.
860 * @master: the MTD device to unregister. This will unregister both the master
861 * and any partitions if registered.
863 int mtd_device_unregister(struct mtd_info *master)
868 unregister_reboot_notifier(&master->reboot_notifier);
870 err = del_mtd_partitions(master);
874 if (!device_is_registered(&master->dev))
877 return del_mtd_device(master);
879 EXPORT_SYMBOL_GPL(mtd_device_unregister);
882 * register_mtd_user - register a 'user' of MTD devices.
883 * @new: pointer to notifier info structure
885 * Registers a pair of callbacks function to be called upon addition
886 * or removal of MTD devices. Causes the 'add' callback to be immediately
887 * invoked for each MTD device currently present in the system.
889 void register_mtd_user (struct mtd_notifier *new)
891 struct mtd_info *mtd;
893 mutex_lock(&mtd_table_mutex);
895 list_add(&new->list, &mtd_notifiers);
897 __module_get(THIS_MODULE);
899 mtd_for_each_device(mtd)
902 mutex_unlock(&mtd_table_mutex);
904 EXPORT_SYMBOL_GPL(register_mtd_user);
907 * unregister_mtd_user - unregister a 'user' of MTD devices.
908 * @old: pointer to notifier info structure
910 * Removes a callback function pair from the list of 'users' to be
911 * notified upon addition or removal of MTD devices. Causes the
912 * 'remove' callback to be immediately invoked for each MTD device
913 * currently present in the system.
915 int unregister_mtd_user (struct mtd_notifier *old)
917 struct mtd_info *mtd;
919 mutex_lock(&mtd_table_mutex);
921 module_put(THIS_MODULE);
923 mtd_for_each_device(mtd)
926 list_del(&old->list);
927 mutex_unlock(&mtd_table_mutex);
930 EXPORT_SYMBOL_GPL(unregister_mtd_user);
933 * get_mtd_device - obtain a validated handle for an MTD device
934 * @mtd: last known address of the required MTD device
935 * @num: internal device number of the required MTD device
937 * Given a number and NULL address, return the num'th entry in the device
938 * table, if any. Given an address and num == -1, search the device table
939 * for a device with that address and return if it's still present. Given
940 * both, return the num'th driver only if its address matches. Return
943 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
945 struct mtd_info *ret = NULL, *other;
948 mutex_lock(&mtd_table_mutex);
951 mtd_for_each_device(other) {
957 } else if (num >= 0) {
958 ret = idr_find(&mtd_idr, num);
959 if (mtd && mtd != ret)
968 err = __get_mtd_device(ret);
972 mutex_unlock(&mtd_table_mutex);
975 EXPORT_SYMBOL_GPL(get_mtd_device);
978 int __get_mtd_device(struct mtd_info *mtd)
980 struct mtd_info *master = mtd_get_master(mtd);
983 if (!try_module_get(master->owner))
986 if (master->_get_device) {
987 err = master->_get_device(mtd);
990 module_put(master->owner);
995 while (mtd->parent) {
1002 EXPORT_SYMBOL_GPL(__get_mtd_device);
1005 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1007 * @name: MTD device name to open
1009 * This function returns MTD device description structure in case of
1010 * success and an error code in case of failure.
1012 struct mtd_info *get_mtd_device_nm(const char *name)
1015 struct mtd_info *mtd = NULL, *other;
1017 mutex_lock(&mtd_table_mutex);
1019 mtd_for_each_device(other) {
1020 if (!strcmp(name, other->name)) {
1029 err = __get_mtd_device(mtd);
1033 mutex_unlock(&mtd_table_mutex);
1037 mutex_unlock(&mtd_table_mutex);
1038 return ERR_PTR(err);
1040 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1042 void put_mtd_device(struct mtd_info *mtd)
1044 mutex_lock(&mtd_table_mutex);
1045 __put_mtd_device(mtd);
1046 mutex_unlock(&mtd_table_mutex);
1049 EXPORT_SYMBOL_GPL(put_mtd_device);
1051 void __put_mtd_device(struct mtd_info *mtd)
1053 struct mtd_info *master = mtd_get_master(mtd);
1055 while (mtd->parent) {
1057 BUG_ON(mtd->usecount < 0);
1061 if (master->_put_device)
1062 master->_put_device(master);
1064 module_put(master->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 struct mtd_info *master = mtd_get_master(mtd);
1076 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1079 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1081 if (!mtd->erasesize || !master->_erase)
1084 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1086 if (!(mtd->flags & MTD_WRITEABLE))
1092 ledtrig_mtd_activity();
1094 instr->addr += mst_ofs;
1095 ret = master->_erase(master, instr);
1096 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
1097 instr->fail_addr -= mst_ofs;
1099 instr->addr -= mst_ofs;
1102 EXPORT_SYMBOL_GPL(mtd_erase);
1105 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1107 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1108 void **virt, resource_size_t *phys)
1110 struct mtd_info *master = mtd_get_master(mtd);
1116 if (!master->_point)
1118 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1123 from = mtd_get_master_ofs(mtd, from);
1124 return master->_point(master, from, len, retlen, virt, phys);
1126 EXPORT_SYMBOL_GPL(mtd_point);
1128 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1129 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1131 struct mtd_info *master = mtd_get_master(mtd);
1133 if (!master->_unpoint)
1135 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1139 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1141 EXPORT_SYMBOL_GPL(mtd_unpoint);
1144 * Allow NOMMU mmap() to directly map the device (if not NULL)
1145 * - return the address to which the offset maps
1146 * - return -ENOSYS to indicate refusal to do the mapping
1148 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1149 unsigned long offset, unsigned long flags)
1155 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1158 if (retlen != len) {
1159 mtd_unpoint(mtd, offset, retlen);
1162 return (unsigned long)virt;
1164 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1166 static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1167 const struct mtd_ecc_stats *old_stats)
1169 struct mtd_ecc_stats diff;
1174 diff = master->ecc_stats;
1175 diff.failed -= old_stats->failed;
1176 diff.corrected -= old_stats->corrected;
1178 while (mtd->parent) {
1179 mtd->ecc_stats.failed += diff.failed;
1180 mtd->ecc_stats.corrected += diff.corrected;
1185 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1188 struct mtd_oob_ops ops = {
1194 ret = mtd_read_oob(mtd, from, &ops);
1195 *retlen = ops.retlen;
1199 EXPORT_SYMBOL_GPL(mtd_read);
1201 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1204 struct mtd_oob_ops ops = {
1206 .datbuf = (u8 *)buf,
1210 ret = mtd_write_oob(mtd, to, &ops);
1211 *retlen = ops.retlen;
1215 EXPORT_SYMBOL_GPL(mtd_write);
1218 * In blackbox flight recorder like scenarios we want to make successful writes
1219 * in interrupt context. panic_write() is only intended to be called when its
1220 * known the kernel is about to panic and we need the write to succeed. Since
1221 * the kernel is not going to be running for much longer, this function can
1222 * break locks and delay to ensure the write succeeds (but not sleep).
1224 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1227 struct mtd_info *master = mtd_get_master(mtd);
1230 if (!master->_panic_write)
1232 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1234 if (!(mtd->flags & MTD_WRITEABLE))
1238 if (!mtd->oops_panic_write)
1239 mtd->oops_panic_write = true;
1241 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1244 EXPORT_SYMBOL_GPL(mtd_panic_write);
1246 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1247 struct mtd_oob_ops *ops)
1250 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1251 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1260 if (offs < 0 || offs + ops->len > mtd->size)
1266 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1269 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1270 mtd_div_by_ws(offs, mtd)) *
1271 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1272 if (ops->ooblen > maxooblen)
1279 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1281 struct mtd_info *master = mtd_get_master(mtd);
1282 struct mtd_ecc_stats old_stats = master->ecc_stats;
1285 ops->retlen = ops->oobretlen = 0;
1287 ret_code = mtd_check_oob_ops(mtd, from, ops);
1291 ledtrig_mtd_activity();
1293 /* Check the validity of a potential fallback on mtd->_read */
1294 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1297 from = mtd_get_master_ofs(mtd, from);
1298 if (master->_read_oob)
1299 ret_code = master->_read_oob(master, from, ops);
1301 ret_code = master->_read(master, from, ops->len, &ops->retlen,
1304 mtd_update_ecc_stats(mtd, master, &old_stats);
1307 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1308 * similar to mtd->_read(), returning a non-negative integer
1309 * representing max bitflips. In other cases, mtd->_read_oob() may
1310 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1312 if (unlikely(ret_code < 0))
1314 if (mtd->ecc_strength == 0)
1315 return 0; /* device lacks ecc */
1316 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1318 EXPORT_SYMBOL_GPL(mtd_read_oob);
1320 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1321 struct mtd_oob_ops *ops)
1323 struct mtd_info *master = mtd_get_master(mtd);
1326 ops->retlen = ops->oobretlen = 0;
1328 if (!(mtd->flags & MTD_WRITEABLE))
1331 ret = mtd_check_oob_ops(mtd, to, ops);
1335 ledtrig_mtd_activity();
1337 /* Check the validity of a potential fallback on mtd->_write */
1338 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1341 to = mtd_get_master_ofs(mtd, to);
1343 if (master->_write_oob)
1344 return master->_write_oob(master, to, ops);
1346 return master->_write(master, to, ops->len, &ops->retlen,
1349 EXPORT_SYMBOL_GPL(mtd_write_oob);
1352 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1353 * @mtd: MTD device structure
1354 * @section: ECC section. Depending on the layout you may have all the ECC
1355 * bytes stored in a single contiguous section, or one section
1356 * per ECC chunk (and sometime several sections for a single ECC
1358 * @oobecc: OOB region struct filled with the appropriate ECC position
1361 * This function returns ECC section information in the OOB area. If you want
1362 * to get all the ECC bytes information, then you should call
1363 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1365 * Returns zero on success, a negative error code otherwise.
1367 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1368 struct mtd_oob_region *oobecc)
1370 struct mtd_info *master = mtd_get_master(mtd);
1372 memset(oobecc, 0, sizeof(*oobecc));
1374 if (!master || section < 0)
1377 if (!master->ooblayout || !master->ooblayout->ecc)
1380 return master->ooblayout->ecc(master, section, oobecc);
1382 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1385 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1387 * @mtd: MTD device structure
1388 * @section: Free section you are interested in. Depending on the layout
1389 * you may have all the free bytes stored in a single contiguous
1390 * section, or one section per ECC chunk plus an extra section
1391 * for the remaining bytes (or other funky layout).
1392 * @oobfree: OOB region struct filled with the appropriate free position
1395 * This function returns free bytes position in the OOB area. If you want
1396 * to get all the free bytes information, then you should call
1397 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1399 * Returns zero on success, a negative error code otherwise.
1401 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1402 struct mtd_oob_region *oobfree)
1404 struct mtd_info *master = mtd_get_master(mtd);
1406 memset(oobfree, 0, sizeof(*oobfree));
1408 if (!master || section < 0)
1411 if (!master->ooblayout || !master->ooblayout->free)
1414 return master->ooblayout->free(master, section, oobfree);
1416 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1419 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1420 * @mtd: mtd info structure
1421 * @byte: the byte we are searching for
1422 * @sectionp: pointer where the section id will be stored
1423 * @oobregion: used to retrieve the ECC position
1424 * @iter: iterator function. Should be either mtd_ooblayout_free or
1425 * mtd_ooblayout_ecc depending on the region type you're searching for
1427 * This function returns the section id and oobregion information of a
1428 * specific byte. For example, say you want to know where the 4th ECC byte is
1429 * stored, you'll use:
1431 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1433 * Returns zero on success, a negative error code otherwise.
1435 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1436 int *sectionp, struct mtd_oob_region *oobregion,
1437 int (*iter)(struct mtd_info *,
1439 struct mtd_oob_region *oobregion))
1441 int pos = 0, ret, section = 0;
1443 memset(oobregion, 0, sizeof(*oobregion));
1446 ret = iter(mtd, section, oobregion);
1450 if (pos + oobregion->length > byte)
1453 pos += oobregion->length;
1458 * Adjust region info to make it start at the beginning at the
1461 oobregion->offset += byte - pos;
1462 oobregion->length -= byte - pos;
1463 *sectionp = section;
1469 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1471 * @mtd: mtd info structure
1472 * @eccbyte: the byte we are searching for
1473 * @sectionp: pointer where the section id will be stored
1474 * @oobregion: OOB region information
1476 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1479 * Returns zero on success, a negative error code otherwise.
1481 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1483 struct mtd_oob_region *oobregion)
1485 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1488 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1491 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1492 * @mtd: mtd info structure
1493 * @buf: destination buffer to store OOB bytes
1494 * @oobbuf: OOB buffer
1495 * @start: first byte to retrieve
1496 * @nbytes: number of bytes to retrieve
1497 * @iter: section iterator
1499 * Extract bytes attached to a specific category (ECC or free)
1500 * from the OOB buffer and copy them into buf.
1502 * Returns zero on success, a negative error code otherwise.
1504 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1505 const u8 *oobbuf, int start, int nbytes,
1506 int (*iter)(struct mtd_info *,
1508 struct mtd_oob_region *oobregion))
1510 struct mtd_oob_region oobregion;
1513 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1519 cnt = min_t(int, nbytes, oobregion.length);
1520 memcpy(buf, oobbuf + oobregion.offset, cnt);
1527 ret = iter(mtd, ++section, &oobregion);
1534 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1535 * @mtd: mtd info structure
1536 * @buf: source buffer to get OOB bytes from
1537 * @oobbuf: OOB buffer
1538 * @start: first OOB byte to set
1539 * @nbytes: number of OOB bytes to set
1540 * @iter: section iterator
1542 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1543 * is selected by passing the appropriate iterator.
1545 * Returns zero on success, a negative error code otherwise.
1547 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1548 u8 *oobbuf, int start, int nbytes,
1549 int (*iter)(struct mtd_info *,
1551 struct mtd_oob_region *oobregion))
1553 struct mtd_oob_region oobregion;
1556 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1562 cnt = min_t(int, nbytes, oobregion.length);
1563 memcpy(oobbuf + oobregion.offset, buf, cnt);
1570 ret = iter(mtd, ++section, &oobregion);
1577 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1578 * @mtd: mtd info structure
1579 * @iter: category iterator
1581 * Count the number of bytes in a given category.
1583 * Returns a positive value on success, a negative error code otherwise.
1585 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1586 int (*iter)(struct mtd_info *,
1588 struct mtd_oob_region *oobregion))
1590 struct mtd_oob_region oobregion;
1591 int section = 0, ret, nbytes = 0;
1594 ret = iter(mtd, section++, &oobregion);
1601 nbytes += oobregion.length;
1608 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1609 * @mtd: mtd info structure
1610 * @eccbuf: destination buffer to store ECC bytes
1611 * @oobbuf: OOB buffer
1612 * @start: first ECC byte to retrieve
1613 * @nbytes: number of ECC bytes to retrieve
1615 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1617 * Returns zero on success, a negative error code otherwise.
1619 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1620 const u8 *oobbuf, int start, int nbytes)
1622 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1625 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1628 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1629 * @mtd: mtd info structure
1630 * @eccbuf: source buffer to get ECC bytes from
1631 * @oobbuf: OOB buffer
1632 * @start: first ECC byte to set
1633 * @nbytes: number of ECC bytes to set
1635 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1637 * Returns zero on success, a negative error code otherwise.
1639 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1640 u8 *oobbuf, int start, int nbytes)
1642 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1645 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1648 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1649 * @mtd: mtd info structure
1650 * @databuf: destination buffer to store ECC bytes
1651 * @oobbuf: OOB buffer
1652 * @start: first ECC byte to retrieve
1653 * @nbytes: number of ECC bytes to retrieve
1655 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1657 * Returns zero on success, a negative error code otherwise.
1659 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1660 const u8 *oobbuf, int start, int nbytes)
1662 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1663 mtd_ooblayout_free);
1665 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1668 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1669 * @mtd: mtd info structure
1670 * @databuf: source buffer to get data bytes from
1671 * @oobbuf: OOB buffer
1672 * @start: first ECC byte to set
1673 * @nbytes: number of ECC bytes to set
1675 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1677 * Returns zero on success, a negative error code otherwise.
1679 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1680 u8 *oobbuf, int start, int nbytes)
1682 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1683 mtd_ooblayout_free);
1685 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1688 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1689 * @mtd: mtd info structure
1691 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1693 * Returns zero on success, a negative error code otherwise.
1695 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1697 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1699 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1702 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1703 * @mtd: mtd info structure
1705 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1707 * Returns zero on success, a negative error code otherwise.
1709 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1711 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1713 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1716 * Method to access the protection register area, present in some flash
1717 * devices. The user data is one time programmable but the factory data is read
1720 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1721 struct otp_info *buf)
1723 struct mtd_info *master = mtd_get_master(mtd);
1725 if (!master->_get_fact_prot_info)
1729 return master->_get_fact_prot_info(master, len, retlen, buf);
1731 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1733 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1734 size_t *retlen, u_char *buf)
1736 struct mtd_info *master = mtd_get_master(mtd);
1739 if (!master->_read_fact_prot_reg)
1743 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
1745 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1747 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1748 struct otp_info *buf)
1750 struct mtd_info *master = mtd_get_master(mtd);
1752 if (!master->_get_user_prot_info)
1756 return master->_get_user_prot_info(master, len, retlen, buf);
1758 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1760 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1761 size_t *retlen, u_char *buf)
1763 struct mtd_info *master = mtd_get_master(mtd);
1766 if (!master->_read_user_prot_reg)
1770 return master->_read_user_prot_reg(master, from, len, retlen, buf);
1772 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1774 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1775 size_t *retlen, u_char *buf)
1777 struct mtd_info *master = mtd_get_master(mtd);
1781 if (!master->_write_user_prot_reg)
1785 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
1790 * If no data could be written at all, we are out of memory and
1791 * must return -ENOSPC.
1793 return (*retlen) ? 0 : -ENOSPC;
1795 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1797 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1799 struct mtd_info *master = mtd_get_master(mtd);
1801 if (!master->_lock_user_prot_reg)
1805 return master->_lock_user_prot_reg(master, from, len);
1807 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1809 /* Chip-supported device locking */
1810 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1812 struct mtd_info *master = mtd_get_master(mtd);
1816 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1820 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
1822 EXPORT_SYMBOL_GPL(mtd_lock);
1824 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1826 struct mtd_info *master = mtd_get_master(mtd);
1828 if (!master->_unlock)
1830 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1834 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
1836 EXPORT_SYMBOL_GPL(mtd_unlock);
1838 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1840 struct mtd_info *master = mtd_get_master(mtd);
1842 if (!master->_is_locked)
1844 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1848 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
1850 EXPORT_SYMBOL_GPL(mtd_is_locked);
1852 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1854 struct mtd_info *master = mtd_get_master(mtd);
1856 if (ofs < 0 || ofs >= mtd->size)
1858 if (!master->_block_isreserved)
1860 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
1862 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1864 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1866 struct mtd_info *master = mtd_get_master(mtd);
1868 if (ofs < 0 || ofs >= mtd->size)
1870 if (!master->_block_isbad)
1872 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
1874 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1876 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1878 struct mtd_info *master = mtd_get_master(mtd);
1881 if (!master->_block_markbad)
1883 if (ofs < 0 || ofs >= mtd->size)
1885 if (!(mtd->flags & MTD_WRITEABLE))
1888 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
1892 while (mtd->parent) {
1893 mtd->ecc_stats.badblocks++;
1899 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1902 * default_mtd_writev - the default writev method
1903 * @mtd: mtd device description object pointer
1904 * @vecs: the vectors to write
1905 * @count: count of vectors in @vecs
1906 * @to: the MTD device offset to write to
1907 * @retlen: on exit contains the count of bytes written to the MTD device.
1909 * This function returns zero in case of success and a negative error code in
1912 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1913 unsigned long count, loff_t to, size_t *retlen)
1916 size_t totlen = 0, thislen;
1919 for (i = 0; i < count; i++) {
1920 if (!vecs[i].iov_len)
1922 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1925 if (ret || thislen != vecs[i].iov_len)
1927 to += vecs[i].iov_len;
1934 * mtd_writev - the vector-based MTD write method
1935 * @mtd: mtd device description object pointer
1936 * @vecs: the vectors to write
1937 * @count: count of vectors in @vecs
1938 * @to: the MTD device offset to write to
1939 * @retlen: on exit contains the count of bytes written to the MTD device.
1941 * This function returns zero in case of success and a negative error code in
1944 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1945 unsigned long count, loff_t to, size_t *retlen)
1947 struct mtd_info *master = mtd_get_master(mtd);
1950 if (!(mtd->flags & MTD_WRITEABLE))
1953 if (!master->_writev)
1954 return default_mtd_writev(mtd, vecs, count, to, retlen);
1956 return master->_writev(master, vecs, count,
1957 mtd_get_master_ofs(mtd, to), retlen);
1959 EXPORT_SYMBOL_GPL(mtd_writev);
1962 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1963 * @mtd: mtd device description object pointer
1964 * @size: a pointer to the ideal or maximum size of the allocation, points
1965 * to the actual allocation size on success.
1967 * This routine attempts to allocate a contiguous kernel buffer up to
1968 * the specified size, backing off the size of the request exponentially
1969 * until the request succeeds or until the allocation size falls below
1970 * the system page size. This attempts to make sure it does not adversely
1971 * impact system performance, so when allocating more than one page, we
1972 * ask the memory allocator to avoid re-trying, swapping, writing back
1973 * or performing I/O.
1975 * Note, this function also makes sure that the allocated buffer is aligned to
1976 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1978 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1979 * to handle smaller (i.e. degraded) buffer allocations under low- or
1980 * fragmented-memory situations where such reduced allocations, from a
1981 * requested ideal, are allowed.
1983 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1985 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1987 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1988 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1991 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1993 while (*size > min_alloc) {
1994 kbuf = kmalloc(*size, flags);
1999 *size = ALIGN(*size, mtd->writesize);
2003 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2004 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2006 return kmalloc(*size, GFP_KERNEL);
2008 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2010 #ifdef CONFIG_PROC_FS
2012 /*====================================================================*/
2013 /* Support for /proc/mtd */
2015 static int mtd_proc_show(struct seq_file *m, void *v)
2017 struct mtd_info *mtd;
2019 seq_puts(m, "dev: size erasesize name\n");
2020 mutex_lock(&mtd_table_mutex);
2021 mtd_for_each_device(mtd) {
2022 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2023 mtd->index, (unsigned long long)mtd->size,
2024 mtd->erasesize, mtd->name);
2026 mutex_unlock(&mtd_table_mutex);
2029 #endif /* CONFIG_PROC_FS */
2031 /*====================================================================*/
2034 static struct backing_dev_info * __init mtd_bdi_init(char *name)
2036 struct backing_dev_info *bdi;
2039 bdi = bdi_alloc(GFP_KERNEL);
2041 return ERR_PTR(-ENOMEM);
2045 * We put '-0' suffix to the name to get the same name format as we
2046 * used to get. Since this is called only once, we get a unique name.
2048 ret = bdi_register(bdi, "%.28s-0", name);
2052 return ret ? ERR_PTR(ret) : bdi;
2055 static struct proc_dir_entry *proc_mtd;
2057 static int __init init_mtd(void)
2061 ret = class_register(&mtd_class);
2065 mtd_bdi = mtd_bdi_init("mtd");
2066 if (IS_ERR(mtd_bdi)) {
2067 ret = PTR_ERR(mtd_bdi);
2071 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2073 ret = init_mtdchar();
2077 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2083 remove_proc_entry("mtd", NULL);
2086 class_unregister(&mtd_class);
2088 pr_err("Error registering mtd class or bdi: %d\n", ret);
2092 static void __exit cleanup_mtd(void)
2094 debugfs_remove_recursive(dfs_dir_mtd);
2097 remove_proc_entry("mtd", NULL);
2098 class_unregister(&mtd_class);
2100 idr_destroy(&mtd_idr);
2103 module_init(init_mtd);
2104 module_exit(cleanup_mtd);
2106 MODULE_LICENSE("GPL");
2107 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2108 MODULE_DESCRIPTION("Core MTD registration and access routines");