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_debug_show(struct seq_file *s, void *p)
340 struct mtd_info *mtd = s->private;
342 seq_printf(s, "%s\n", mtd->dbg.partid);
347 DEFINE_SHOW_ATTRIBUTE(mtd_partid_debug);
349 static int mtd_partname_debug_show(struct seq_file *s, void *p)
351 struct mtd_info *mtd = s->private;
353 seq_printf(s, "%s\n", mtd->dbg.partname);
358 DEFINE_SHOW_ATTRIBUTE(mtd_partname_debug);
360 static struct dentry *dfs_dir_mtd;
362 static void mtd_debugfs_populate(struct mtd_info *mtd)
364 struct device *dev = &mtd->dev;
367 if (IS_ERR_OR_NULL(dfs_dir_mtd))
370 root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
371 mtd->dbg.dfs_dir = root;
374 debugfs_create_file("partid", 0400, root, mtd,
375 &mtd_partid_debug_fops);
377 if (mtd->dbg.partname)
378 debugfs_create_file("partname", 0400, root, mtd,
379 &mtd_partname_debug_fops);
383 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
387 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
388 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
390 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
393 return NOMMU_MAP_COPY;
396 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
399 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
402 struct mtd_info *mtd;
404 mtd = container_of(n, struct mtd_info, reboot_notifier);
411 * mtd_wunit_to_pairing_info - get pairing information of a wunit
412 * @mtd: pointer to new MTD device info structure
413 * @wunit: write unit we are interested in
414 * @info: returned pairing information
416 * Retrieve pairing information associated to the wunit.
417 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
418 * paired together, and where programming a page may influence the page it is
420 * The notion of page is replaced by the term wunit (write-unit) to stay
421 * consistent with the ->writesize field.
423 * The @wunit argument can be extracted from an absolute offset using
424 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
427 * From the pairing info the MTD user can find all the wunits paired with
428 * @wunit using the following loop:
430 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
432 * mtd_pairing_info_to_wunit(mtd, &info);
436 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
437 struct mtd_pairing_info *info)
439 struct mtd_info *master = mtd_get_master(mtd);
440 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
442 if (wunit < 0 || wunit >= npairs)
445 if (master->pairing && master->pairing->get_info)
446 return master->pairing->get_info(master, wunit, info);
453 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
456 * mtd_pairing_info_to_wunit - get wunit from pairing information
457 * @mtd: pointer to new MTD device info structure
458 * @info: pairing information struct
460 * Returns a positive number representing the wunit associated to the info
461 * struct, or a negative error code.
463 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
464 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
467 * It can also be used to only program the first page of each pair (i.e.
468 * page attached to group 0), which allows one to use an MLC NAND in
469 * software-emulated SLC mode:
472 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
473 * for (info.pair = 0; info.pair < npairs; info.pair++) {
474 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
475 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
476 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
479 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
480 const struct mtd_pairing_info *info)
482 struct mtd_info *master = mtd_get_master(mtd);
483 int ngroups = mtd_pairing_groups(master);
484 int npairs = mtd_wunit_per_eb(master) / ngroups;
486 if (!info || info->pair < 0 || info->pair >= npairs ||
487 info->group < 0 || info->group >= ngroups)
490 if (master->pairing && master->pairing->get_wunit)
491 return mtd->pairing->get_wunit(master, info);
495 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
498 * mtd_pairing_groups - get the number of pairing groups
499 * @mtd: pointer to new MTD device info structure
501 * Returns the number of pairing groups.
503 * This number is usually equal to the number of bits exposed by a single
504 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
505 * to iterate over all pages of a given pair.
507 int mtd_pairing_groups(struct mtd_info *mtd)
509 struct mtd_info *master = mtd_get_master(mtd);
511 if (!master->pairing || !master->pairing->ngroups)
514 return master->pairing->ngroups;
516 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
518 static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
519 void *val, size_t bytes)
521 struct mtd_info *mtd = priv;
525 err = mtd_read(mtd, offset, bytes, &retlen, val);
526 if (err && err != -EUCLEAN)
529 return retlen == bytes ? 0 : -EIO;
532 static int mtd_nvmem_add(struct mtd_info *mtd)
534 struct nvmem_config config = {};
537 config.dev = &mtd->dev;
538 config.name = dev_name(&mtd->dev);
539 config.owner = THIS_MODULE;
540 config.reg_read = mtd_nvmem_reg_read;
541 config.size = mtd->size;
542 config.word_size = 1;
544 config.read_only = true;
545 config.root_only = true;
546 config.no_of_node = true;
549 mtd->nvmem = nvmem_register(&config);
550 if (IS_ERR(mtd->nvmem)) {
551 /* Just ignore if there is no NVMEM support in the kernel */
552 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
555 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
556 return PTR_ERR(mtd->nvmem);
564 * add_mtd_device - register an MTD device
565 * @mtd: pointer to new MTD device info structure
567 * Add a device to the list of MTD devices present in the system, and
568 * notify each currently active MTD 'user' of its arrival. Returns
569 * zero on success or non-zero on failure.
572 int add_mtd_device(struct mtd_info *mtd)
574 struct mtd_info *master = mtd_get_master(mtd);
575 struct mtd_notifier *not;
579 * May occur, for instance, on buggy drivers which call
580 * mtd_device_parse_register() multiple times on the same master MTD,
581 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
583 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
586 BUG_ON(mtd->writesize == 0);
589 * MTD drivers should implement ->_{write,read}() or
590 * ->_{write,read}_oob(), but not both.
592 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
593 (mtd->_read && mtd->_read_oob)))
596 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
597 !(mtd->flags & MTD_NO_ERASE)))
601 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
602 * master is an MLC NAND and has a proper pairing scheme defined.
603 * We also reject masters that implement ->_writev() for now, because
604 * NAND controller drivers don't implement this hook, and adding the
605 * SLC -> MLC address/length conversion to this path is useless if we
608 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
609 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
610 !master->pairing || master->_writev))
613 mutex_lock(&mtd_table_mutex);
615 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
624 /* default value if not set by driver */
625 if (mtd->bitflip_threshold == 0)
626 mtd->bitflip_threshold = mtd->ecc_strength;
628 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
629 int ngroups = mtd_pairing_groups(master);
631 mtd->erasesize /= ngroups;
632 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
636 if (is_power_of_2(mtd->erasesize))
637 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
639 mtd->erasesize_shift = 0;
641 if (is_power_of_2(mtd->writesize))
642 mtd->writesize_shift = ffs(mtd->writesize) - 1;
644 mtd->writesize_shift = 0;
646 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
647 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
649 /* Some chips always power up locked. Unlock them now */
650 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
651 error = mtd_unlock(mtd, 0, mtd->size);
652 if (error && error != -EOPNOTSUPP)
654 "%s: unlock failed, writes may not work\n",
656 /* Ignore unlock failures? */
660 /* Caller should have set dev.parent to match the
661 * physical device, if appropriate.
663 mtd->dev.type = &mtd_devtype;
664 mtd->dev.class = &mtd_class;
665 mtd->dev.devt = MTD_DEVT(i);
666 dev_set_name(&mtd->dev, "mtd%d", i);
667 dev_set_drvdata(&mtd->dev, mtd);
668 of_node_get(mtd_get_of_node(mtd));
669 error = device_register(&mtd->dev);
673 /* Add the nvmem provider */
674 error = mtd_nvmem_add(mtd);
678 mtd_debugfs_populate(mtd);
680 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
683 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
684 /* No need to get a refcount on the module containing
685 the notifier, since we hold the mtd_table_mutex */
686 list_for_each_entry(not, &mtd_notifiers, list)
689 mutex_unlock(&mtd_table_mutex);
690 /* We _know_ we aren't being removed, because
691 our caller is still holding us here. So none
692 of this try_ nonsense, and no bitching about it
694 __module_get(THIS_MODULE);
698 device_unregister(&mtd->dev);
700 of_node_put(mtd_get_of_node(mtd));
701 idr_remove(&mtd_idr, i);
703 mutex_unlock(&mtd_table_mutex);
708 * del_mtd_device - unregister an MTD device
709 * @mtd: pointer to MTD device info structure
711 * Remove a device from the list of MTD devices present in the system,
712 * and notify each currently active MTD 'user' of its departure.
713 * Returns zero on success or 1 on failure, which currently will happen
714 * if the requested device does not appear to be present in the list.
717 int del_mtd_device(struct mtd_info *mtd)
720 struct mtd_notifier *not;
722 mutex_lock(&mtd_table_mutex);
724 debugfs_remove_recursive(mtd->dbg.dfs_dir);
726 if (idr_find(&mtd_idr, mtd->index) != mtd) {
731 /* No need to get a refcount on the module containing
732 the notifier, since we hold the mtd_table_mutex */
733 list_for_each_entry(not, &mtd_notifiers, list)
737 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
738 mtd->index, mtd->name, mtd->usecount);
741 /* Try to remove the NVMEM provider */
743 nvmem_unregister(mtd->nvmem);
745 device_unregister(&mtd->dev);
747 idr_remove(&mtd_idr, mtd->index);
748 of_node_put(mtd_get_of_node(mtd));
750 module_put(THIS_MODULE);
755 mutex_unlock(&mtd_table_mutex);
760 * Set a few defaults based on the parent devices, if not provided by the
763 static void mtd_set_dev_defaults(struct mtd_info *mtd)
765 if (mtd->dev.parent) {
766 if (!mtd->owner && mtd->dev.parent->driver)
767 mtd->owner = mtd->dev.parent->driver->owner;
769 mtd->name = dev_name(mtd->dev.parent);
771 pr_debug("mtd device won't show a device symlink in sysfs\n");
774 INIT_LIST_HEAD(&mtd->partitions);
775 mutex_init(&mtd->master.partitions_lock);
776 mutex_init(&mtd->master.chrdev_lock);
780 * mtd_device_parse_register - parse partitions and register an MTD device.
782 * @mtd: the MTD device to register
783 * @types: the list of MTD partition probes to try, see
784 * 'parse_mtd_partitions()' for more information
785 * @parser_data: MTD partition parser-specific data
786 * @parts: fallback partition information to register, if parsing fails;
787 * only valid if %nr_parts > %0
788 * @nr_parts: the number of partitions in parts, if zero then the full
789 * MTD device is registered if no partition info is found
791 * This function aggregates MTD partitions parsing (done by
792 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
793 * basically follows the most common pattern found in many MTD drivers:
795 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
797 * * Then It tries to probe partitions on MTD device @mtd using parsers
798 * specified in @types (if @types is %NULL, then the default list of parsers
799 * is used, see 'parse_mtd_partitions()' for more information). If none are
800 * found this functions tries to fallback to information specified in
802 * * If no partitions were found this function just registers the MTD device
805 * Returns zero in case of success and a negative error code in case of failure.
807 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
808 struct mtd_part_parser_data *parser_data,
809 const struct mtd_partition *parts,
814 mtd_set_dev_defaults(mtd);
816 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
817 ret = add_mtd_device(mtd);
822 /* Prefer parsed partitions over driver-provided fallback */
823 ret = parse_mtd_partitions(mtd, types, parser_data);
827 ret = add_mtd_partitions(mtd, parts, nr_parts);
828 else if (!device_is_registered(&mtd->dev))
829 ret = add_mtd_device(mtd);
837 * FIXME: some drivers unfortunately call this function more than once.
838 * So we have to check if we've already assigned the reboot notifier.
840 * Generally, we can make multiple calls work for most cases, but it
841 * does cause problems with parse_mtd_partitions() above (e.g.,
842 * cmdlineparts will register partitions more than once).
844 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
845 "MTD already registered\n");
846 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
847 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
848 register_reboot_notifier(&mtd->reboot_notifier);
852 if (ret && device_is_registered(&mtd->dev))
857 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
860 * mtd_device_unregister - unregister an existing MTD device.
862 * @master: the MTD device to unregister. This will unregister both the master
863 * and any partitions if registered.
865 int mtd_device_unregister(struct mtd_info *master)
870 unregister_reboot_notifier(&master->reboot_notifier);
872 err = del_mtd_partitions(master);
876 if (!device_is_registered(&master->dev))
879 return del_mtd_device(master);
881 EXPORT_SYMBOL_GPL(mtd_device_unregister);
884 * register_mtd_user - register a 'user' of MTD devices.
885 * @new: pointer to notifier info structure
887 * Registers a pair of callbacks function to be called upon addition
888 * or removal of MTD devices. Causes the 'add' callback to be immediately
889 * invoked for each MTD device currently present in the system.
891 void register_mtd_user (struct mtd_notifier *new)
893 struct mtd_info *mtd;
895 mutex_lock(&mtd_table_mutex);
897 list_add(&new->list, &mtd_notifiers);
899 __module_get(THIS_MODULE);
901 mtd_for_each_device(mtd)
904 mutex_unlock(&mtd_table_mutex);
906 EXPORT_SYMBOL_GPL(register_mtd_user);
909 * unregister_mtd_user - unregister a 'user' of MTD devices.
910 * @old: pointer to notifier info structure
912 * Removes a callback function pair from the list of 'users' to be
913 * notified upon addition or removal of MTD devices. Causes the
914 * 'remove' callback to be immediately invoked for each MTD device
915 * currently present in the system.
917 int unregister_mtd_user (struct mtd_notifier *old)
919 struct mtd_info *mtd;
921 mutex_lock(&mtd_table_mutex);
923 module_put(THIS_MODULE);
925 mtd_for_each_device(mtd)
928 list_del(&old->list);
929 mutex_unlock(&mtd_table_mutex);
932 EXPORT_SYMBOL_GPL(unregister_mtd_user);
935 * get_mtd_device - obtain a validated handle for an MTD device
936 * @mtd: last known address of the required MTD device
937 * @num: internal device number of the required MTD device
939 * Given a number and NULL address, return the num'th entry in the device
940 * table, if any. Given an address and num == -1, search the device table
941 * for a device with that address and return if it's still present. Given
942 * both, return the num'th driver only if its address matches. Return
945 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
947 struct mtd_info *ret = NULL, *other;
950 mutex_lock(&mtd_table_mutex);
953 mtd_for_each_device(other) {
959 } else if (num >= 0) {
960 ret = idr_find(&mtd_idr, num);
961 if (mtd && mtd != ret)
970 err = __get_mtd_device(ret);
974 mutex_unlock(&mtd_table_mutex);
977 EXPORT_SYMBOL_GPL(get_mtd_device);
980 int __get_mtd_device(struct mtd_info *mtd)
982 struct mtd_info *master = mtd_get_master(mtd);
985 if (!try_module_get(master->owner))
988 if (master->_get_device) {
989 err = master->_get_device(mtd);
992 module_put(master->owner);
999 while (mtd->parent) {
1006 EXPORT_SYMBOL_GPL(__get_mtd_device);
1009 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1011 * @name: MTD device name to open
1013 * This function returns MTD device description structure in case of
1014 * success and an error code in case of failure.
1016 struct mtd_info *get_mtd_device_nm(const char *name)
1019 struct mtd_info *mtd = NULL, *other;
1021 mutex_lock(&mtd_table_mutex);
1023 mtd_for_each_device(other) {
1024 if (!strcmp(name, other->name)) {
1033 err = __get_mtd_device(mtd);
1037 mutex_unlock(&mtd_table_mutex);
1041 mutex_unlock(&mtd_table_mutex);
1042 return ERR_PTR(err);
1044 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1046 void put_mtd_device(struct mtd_info *mtd)
1048 mutex_lock(&mtd_table_mutex);
1049 __put_mtd_device(mtd);
1050 mutex_unlock(&mtd_table_mutex);
1053 EXPORT_SYMBOL_GPL(put_mtd_device);
1055 void __put_mtd_device(struct mtd_info *mtd)
1057 struct mtd_info *master = mtd_get_master(mtd);
1059 while (mtd->parent) {
1061 BUG_ON(mtd->usecount < 0);
1067 if (master->_put_device)
1068 master->_put_device(master);
1070 module_put(master->owner);
1072 EXPORT_SYMBOL_GPL(__put_mtd_device);
1075 * Erase is an synchronous operation. Device drivers are epected to return a
1076 * negative error code if the operation failed and update instr->fail_addr
1077 * to point the portion that was not properly erased.
1079 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1081 struct mtd_info *master = mtd_get_master(mtd);
1082 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1083 struct erase_info adjinstr;
1086 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1089 if (!mtd->erasesize || !master->_erase)
1092 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1094 if (!(mtd->flags & MTD_WRITEABLE))
1100 ledtrig_mtd_activity();
1102 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1103 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1105 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1106 master->erasesize) -
1110 adjinstr.addr += mst_ofs;
1112 ret = master->_erase(master, &adjinstr);
1114 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1115 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1116 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1117 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1119 instr->fail_addr *= mtd->erasesize;
1125 EXPORT_SYMBOL_GPL(mtd_erase);
1128 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1130 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1131 void **virt, resource_size_t *phys)
1133 struct mtd_info *master = mtd_get_master(mtd);
1139 if (!master->_point)
1141 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1146 from = mtd_get_master_ofs(mtd, from);
1147 return master->_point(master, from, len, retlen, virt, phys);
1149 EXPORT_SYMBOL_GPL(mtd_point);
1151 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1152 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1154 struct mtd_info *master = mtd_get_master(mtd);
1156 if (!master->_unpoint)
1158 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1162 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1164 EXPORT_SYMBOL_GPL(mtd_unpoint);
1167 * Allow NOMMU mmap() to directly map the device (if not NULL)
1168 * - return the address to which the offset maps
1169 * - return -ENOSYS to indicate refusal to do the mapping
1171 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1172 unsigned long offset, unsigned long flags)
1178 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1181 if (retlen != len) {
1182 mtd_unpoint(mtd, offset, retlen);
1185 return (unsigned long)virt;
1187 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1189 static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1190 const struct mtd_ecc_stats *old_stats)
1192 struct mtd_ecc_stats diff;
1197 diff = master->ecc_stats;
1198 diff.failed -= old_stats->failed;
1199 diff.corrected -= old_stats->corrected;
1201 while (mtd->parent) {
1202 mtd->ecc_stats.failed += diff.failed;
1203 mtd->ecc_stats.corrected += diff.corrected;
1208 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1211 struct mtd_oob_ops ops = {
1217 ret = mtd_read_oob(mtd, from, &ops);
1218 *retlen = ops.retlen;
1222 EXPORT_SYMBOL_GPL(mtd_read);
1224 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1227 struct mtd_oob_ops ops = {
1229 .datbuf = (u8 *)buf,
1233 ret = mtd_write_oob(mtd, to, &ops);
1234 *retlen = ops.retlen;
1238 EXPORT_SYMBOL_GPL(mtd_write);
1241 * In blackbox flight recorder like scenarios we want to make successful writes
1242 * in interrupt context. panic_write() is only intended to be called when its
1243 * known the kernel is about to panic and we need the write to succeed. Since
1244 * the kernel is not going to be running for much longer, this function can
1245 * break locks and delay to ensure the write succeeds (but not sleep).
1247 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1250 struct mtd_info *master = mtd_get_master(mtd);
1253 if (!master->_panic_write)
1255 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1257 if (!(mtd->flags & MTD_WRITEABLE))
1261 if (!master->oops_panic_write)
1262 master->oops_panic_write = true;
1264 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1267 EXPORT_SYMBOL_GPL(mtd_panic_write);
1269 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1270 struct mtd_oob_ops *ops)
1273 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1274 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1283 if (offs < 0 || offs + ops->len > mtd->size)
1289 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1292 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1293 mtd_div_by_ws(offs, mtd)) *
1294 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1295 if (ops->ooblen > maxooblen)
1302 static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1303 struct mtd_oob_ops *ops)
1305 struct mtd_info *master = mtd_get_master(mtd);
1308 from = mtd_get_master_ofs(mtd, from);
1309 if (master->_read_oob)
1310 ret = master->_read_oob(master, from, ops);
1312 ret = master->_read(master, from, ops->len, &ops->retlen,
1318 static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1319 struct mtd_oob_ops *ops)
1321 struct mtd_info *master = mtd_get_master(mtd);
1324 to = mtd_get_master_ofs(mtd, to);
1325 if (master->_write_oob)
1326 ret = master->_write_oob(master, to, ops);
1328 ret = master->_write(master, to, ops->len, &ops->retlen,
1334 static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1335 struct mtd_oob_ops *ops)
1337 struct mtd_info *master = mtd_get_master(mtd);
1338 int ngroups = mtd_pairing_groups(master);
1339 int npairs = mtd_wunit_per_eb(master) / ngroups;
1340 struct mtd_oob_ops adjops = *ops;
1341 unsigned int wunit, oobavail;
1342 struct mtd_pairing_info info;
1343 int max_bitflips = 0;
1347 ebofs = mtd_mod_by_eb(start, mtd);
1348 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1350 info.pair = mtd_div_by_ws(ebofs, mtd);
1351 pageofs = mtd_mod_by_ws(ebofs, mtd);
1352 oobavail = mtd_oobavail(mtd, ops);
1354 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1357 if (info.pair >= npairs) {
1359 base += master->erasesize;
1362 wunit = mtd_pairing_info_to_wunit(master, &info);
1363 pos = mtd_wunit_to_offset(mtd, base, wunit);
1365 adjops.len = ops->len - ops->retlen;
1366 if (adjops.len > mtd->writesize - pageofs)
1367 adjops.len = mtd->writesize - pageofs;
1369 adjops.ooblen = ops->ooblen - ops->oobretlen;
1370 if (adjops.ooblen > oobavail - adjops.ooboffs)
1371 adjops.ooblen = oobavail - adjops.ooboffs;
1374 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1376 max_bitflips = max(max_bitflips, ret);
1378 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1384 max_bitflips = max(max_bitflips, ret);
1385 ops->retlen += adjops.retlen;
1386 ops->oobretlen += adjops.oobretlen;
1387 adjops.datbuf += adjops.retlen;
1388 adjops.oobbuf += adjops.oobretlen;
1394 return max_bitflips;
1397 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1399 struct mtd_info *master = mtd_get_master(mtd);
1400 struct mtd_ecc_stats old_stats = master->ecc_stats;
1403 ops->retlen = ops->oobretlen = 0;
1405 ret_code = mtd_check_oob_ops(mtd, from, ops);
1409 ledtrig_mtd_activity();
1411 /* Check the validity of a potential fallback on mtd->_read */
1412 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1415 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1416 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1418 ret_code = mtd_read_oob_std(mtd, from, ops);
1420 mtd_update_ecc_stats(mtd, master, &old_stats);
1423 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1424 * similar to mtd->_read(), returning a non-negative integer
1425 * representing max bitflips. In other cases, mtd->_read_oob() may
1426 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1428 if (unlikely(ret_code < 0))
1430 if (mtd->ecc_strength == 0)
1431 return 0; /* device lacks ecc */
1432 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1434 EXPORT_SYMBOL_GPL(mtd_read_oob);
1436 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1437 struct mtd_oob_ops *ops)
1439 struct mtd_info *master = mtd_get_master(mtd);
1442 ops->retlen = ops->oobretlen = 0;
1444 if (!(mtd->flags & MTD_WRITEABLE))
1447 ret = mtd_check_oob_ops(mtd, to, ops);
1451 ledtrig_mtd_activity();
1453 /* Check the validity of a potential fallback on mtd->_write */
1454 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1457 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1458 return mtd_io_emulated_slc(mtd, to, false, ops);
1460 return mtd_write_oob_std(mtd, to, ops);
1462 EXPORT_SYMBOL_GPL(mtd_write_oob);
1465 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1466 * @mtd: MTD device structure
1467 * @section: ECC section. Depending on the layout you may have all the ECC
1468 * bytes stored in a single contiguous section, or one section
1469 * per ECC chunk (and sometime several sections for a single ECC
1471 * @oobecc: OOB region struct filled with the appropriate ECC position
1474 * This function returns ECC section information in the OOB area. If you want
1475 * to get all the ECC bytes information, then you should call
1476 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1478 * Returns zero on success, a negative error code otherwise.
1480 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1481 struct mtd_oob_region *oobecc)
1483 struct mtd_info *master = mtd_get_master(mtd);
1485 memset(oobecc, 0, sizeof(*oobecc));
1487 if (!master || section < 0)
1490 if (!master->ooblayout || !master->ooblayout->ecc)
1493 return master->ooblayout->ecc(master, section, oobecc);
1495 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1498 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1500 * @mtd: MTD device structure
1501 * @section: Free section you are interested in. Depending on the layout
1502 * you may have all the free bytes stored in a single contiguous
1503 * section, or one section per ECC chunk plus an extra section
1504 * for the remaining bytes (or other funky layout).
1505 * @oobfree: OOB region struct filled with the appropriate free position
1508 * This function returns free bytes position in the OOB area. If you want
1509 * to get all the free bytes information, then you should call
1510 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1512 * Returns zero on success, a negative error code otherwise.
1514 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1515 struct mtd_oob_region *oobfree)
1517 struct mtd_info *master = mtd_get_master(mtd);
1519 memset(oobfree, 0, sizeof(*oobfree));
1521 if (!master || section < 0)
1524 if (!master->ooblayout || !master->ooblayout->free)
1527 return master->ooblayout->free(master, section, oobfree);
1529 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1532 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1533 * @mtd: mtd info structure
1534 * @byte: the byte we are searching for
1535 * @sectionp: pointer where the section id will be stored
1536 * @oobregion: used to retrieve the ECC position
1537 * @iter: iterator function. Should be either mtd_ooblayout_free or
1538 * mtd_ooblayout_ecc depending on the region type you're searching for
1540 * This function returns the section id and oobregion information of a
1541 * specific byte. For example, say you want to know where the 4th ECC byte is
1542 * stored, you'll use:
1544 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1546 * Returns zero on success, a negative error code otherwise.
1548 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1549 int *sectionp, struct mtd_oob_region *oobregion,
1550 int (*iter)(struct mtd_info *,
1552 struct mtd_oob_region *oobregion))
1554 int pos = 0, ret, section = 0;
1556 memset(oobregion, 0, sizeof(*oobregion));
1559 ret = iter(mtd, section, oobregion);
1563 if (pos + oobregion->length > byte)
1566 pos += oobregion->length;
1571 * Adjust region info to make it start at the beginning at the
1574 oobregion->offset += byte - pos;
1575 oobregion->length -= byte - pos;
1576 *sectionp = section;
1582 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1584 * @mtd: mtd info structure
1585 * @eccbyte: the byte we are searching for
1586 * @section: pointer where the section id will be stored
1587 * @oobregion: OOB region information
1589 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1592 * Returns zero on success, a negative error code otherwise.
1594 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1596 struct mtd_oob_region *oobregion)
1598 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1601 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1604 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1605 * @mtd: mtd info structure
1606 * @buf: destination buffer to store OOB bytes
1607 * @oobbuf: OOB buffer
1608 * @start: first byte to retrieve
1609 * @nbytes: number of bytes to retrieve
1610 * @iter: section iterator
1612 * Extract bytes attached to a specific category (ECC or free)
1613 * from the OOB buffer and copy them into buf.
1615 * Returns zero on success, a negative error code otherwise.
1617 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1618 const u8 *oobbuf, int start, int nbytes,
1619 int (*iter)(struct mtd_info *,
1621 struct mtd_oob_region *oobregion))
1623 struct mtd_oob_region oobregion;
1626 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1632 cnt = min_t(int, nbytes, oobregion.length);
1633 memcpy(buf, oobbuf + oobregion.offset, cnt);
1640 ret = iter(mtd, ++section, &oobregion);
1647 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1648 * @mtd: mtd info structure
1649 * @buf: source buffer to get OOB bytes from
1650 * @oobbuf: OOB buffer
1651 * @start: first OOB byte to set
1652 * @nbytes: number of OOB bytes to set
1653 * @iter: section iterator
1655 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1656 * is selected by passing the appropriate iterator.
1658 * Returns zero on success, a negative error code otherwise.
1660 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1661 u8 *oobbuf, int start, int nbytes,
1662 int (*iter)(struct mtd_info *,
1664 struct mtd_oob_region *oobregion))
1666 struct mtd_oob_region oobregion;
1669 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1675 cnt = min_t(int, nbytes, oobregion.length);
1676 memcpy(oobbuf + oobregion.offset, buf, cnt);
1683 ret = iter(mtd, ++section, &oobregion);
1690 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1691 * @mtd: mtd info structure
1692 * @iter: category iterator
1694 * Count the number of bytes in a given category.
1696 * Returns a positive value on success, a negative error code otherwise.
1698 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1699 int (*iter)(struct mtd_info *,
1701 struct mtd_oob_region *oobregion))
1703 struct mtd_oob_region oobregion;
1704 int section = 0, ret, nbytes = 0;
1707 ret = iter(mtd, section++, &oobregion);
1714 nbytes += oobregion.length;
1721 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1722 * @mtd: mtd info structure
1723 * @eccbuf: destination buffer to store ECC bytes
1724 * @oobbuf: OOB buffer
1725 * @start: first ECC byte to retrieve
1726 * @nbytes: number of ECC bytes to retrieve
1728 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1730 * Returns zero on success, a negative error code otherwise.
1732 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1733 const u8 *oobbuf, int start, int nbytes)
1735 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1738 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1741 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1742 * @mtd: mtd info structure
1743 * @eccbuf: source buffer to get ECC bytes from
1744 * @oobbuf: OOB buffer
1745 * @start: first ECC byte to set
1746 * @nbytes: number of ECC bytes to set
1748 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1750 * Returns zero on success, a negative error code otherwise.
1752 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1753 u8 *oobbuf, int start, int nbytes)
1755 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1758 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1761 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1762 * @mtd: mtd info structure
1763 * @databuf: destination buffer to store ECC bytes
1764 * @oobbuf: OOB buffer
1765 * @start: first ECC byte to retrieve
1766 * @nbytes: number of ECC bytes to retrieve
1768 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1770 * Returns zero on success, a negative error code otherwise.
1772 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1773 const u8 *oobbuf, int start, int nbytes)
1775 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1776 mtd_ooblayout_free);
1778 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1781 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1782 * @mtd: mtd info structure
1783 * @databuf: source buffer to get data bytes from
1784 * @oobbuf: OOB buffer
1785 * @start: first ECC byte to set
1786 * @nbytes: number of ECC bytes to set
1788 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
1790 * Returns zero on success, a negative error code otherwise.
1792 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1793 u8 *oobbuf, int start, int nbytes)
1795 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1796 mtd_ooblayout_free);
1798 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1801 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1802 * @mtd: mtd info structure
1804 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1806 * Returns zero on success, a negative error code otherwise.
1808 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1810 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1812 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1815 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1816 * @mtd: mtd info structure
1818 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1820 * Returns zero on success, a negative error code otherwise.
1822 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1824 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1826 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1829 * Method to access the protection register area, present in some flash
1830 * devices. The user data is one time programmable but the factory data is read
1833 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1834 struct otp_info *buf)
1836 struct mtd_info *master = mtd_get_master(mtd);
1838 if (!master->_get_fact_prot_info)
1842 return master->_get_fact_prot_info(master, len, retlen, buf);
1844 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1846 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1847 size_t *retlen, u_char *buf)
1849 struct mtd_info *master = mtd_get_master(mtd);
1852 if (!master->_read_fact_prot_reg)
1856 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
1858 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1860 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1861 struct otp_info *buf)
1863 struct mtd_info *master = mtd_get_master(mtd);
1865 if (!master->_get_user_prot_info)
1869 return master->_get_user_prot_info(master, len, retlen, buf);
1871 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1873 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1874 size_t *retlen, u_char *buf)
1876 struct mtd_info *master = mtd_get_master(mtd);
1879 if (!master->_read_user_prot_reg)
1883 return master->_read_user_prot_reg(master, from, len, retlen, buf);
1885 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1887 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1888 size_t *retlen, u_char *buf)
1890 struct mtd_info *master = mtd_get_master(mtd);
1894 if (!master->_write_user_prot_reg)
1898 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
1903 * If no data could be written at all, we are out of memory and
1904 * must return -ENOSPC.
1906 return (*retlen) ? 0 : -ENOSPC;
1908 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1910 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1912 struct mtd_info *master = mtd_get_master(mtd);
1914 if (!master->_lock_user_prot_reg)
1918 return master->_lock_user_prot_reg(master, from, len);
1920 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1922 /* Chip-supported device locking */
1923 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1925 struct mtd_info *master = mtd_get_master(mtd);
1929 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1934 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1935 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1936 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1939 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
1941 EXPORT_SYMBOL_GPL(mtd_lock);
1943 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1945 struct mtd_info *master = mtd_get_master(mtd);
1947 if (!master->_unlock)
1949 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1954 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1955 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1956 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1959 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
1961 EXPORT_SYMBOL_GPL(mtd_unlock);
1963 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1965 struct mtd_info *master = mtd_get_master(mtd);
1967 if (!master->_is_locked)
1969 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1974 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1975 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1976 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1979 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
1981 EXPORT_SYMBOL_GPL(mtd_is_locked);
1983 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1985 struct mtd_info *master = mtd_get_master(mtd);
1987 if (ofs < 0 || ofs >= mtd->size)
1989 if (!master->_block_isreserved)
1992 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1993 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1995 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
1997 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1999 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2001 struct mtd_info *master = mtd_get_master(mtd);
2003 if (ofs < 0 || ofs >= mtd->size)
2005 if (!master->_block_isbad)
2008 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2009 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2011 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2013 EXPORT_SYMBOL_GPL(mtd_block_isbad);
2015 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2017 struct mtd_info *master = mtd_get_master(mtd);
2020 if (!master->_block_markbad)
2022 if (ofs < 0 || ofs >= mtd->size)
2024 if (!(mtd->flags & MTD_WRITEABLE))
2027 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2028 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2030 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2034 while (mtd->parent) {
2035 mtd->ecc_stats.badblocks++;
2041 EXPORT_SYMBOL_GPL(mtd_block_markbad);
2044 * default_mtd_writev - the default writev method
2045 * @mtd: mtd device description object pointer
2046 * @vecs: the vectors to write
2047 * @count: count of vectors in @vecs
2048 * @to: the MTD device offset to write to
2049 * @retlen: on exit contains the count of bytes written to the MTD device.
2051 * This function returns zero in case of success and a negative error code in
2054 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2055 unsigned long count, loff_t to, size_t *retlen)
2058 size_t totlen = 0, thislen;
2061 for (i = 0; i < count; i++) {
2062 if (!vecs[i].iov_len)
2064 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2067 if (ret || thislen != vecs[i].iov_len)
2069 to += vecs[i].iov_len;
2076 * mtd_writev - the vector-based MTD write method
2077 * @mtd: mtd device description object pointer
2078 * @vecs: the vectors to write
2079 * @count: count of vectors in @vecs
2080 * @to: the MTD device offset to write to
2081 * @retlen: on exit contains the count of bytes written to the MTD device.
2083 * This function returns zero in case of success and a negative error code in
2086 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2087 unsigned long count, loff_t to, size_t *retlen)
2089 struct mtd_info *master = mtd_get_master(mtd);
2092 if (!(mtd->flags & MTD_WRITEABLE))
2095 if (!master->_writev)
2096 return default_mtd_writev(mtd, vecs, count, to, retlen);
2098 return master->_writev(master, vecs, count,
2099 mtd_get_master_ofs(mtd, to), retlen);
2101 EXPORT_SYMBOL_GPL(mtd_writev);
2104 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2105 * @mtd: mtd device description object pointer
2106 * @size: a pointer to the ideal or maximum size of the allocation, points
2107 * to the actual allocation size on success.
2109 * This routine attempts to allocate a contiguous kernel buffer up to
2110 * the specified size, backing off the size of the request exponentially
2111 * until the request succeeds or until the allocation size falls below
2112 * the system page size. This attempts to make sure it does not adversely
2113 * impact system performance, so when allocating more than one page, we
2114 * ask the memory allocator to avoid re-trying, swapping, writing back
2115 * or performing I/O.
2117 * Note, this function also makes sure that the allocated buffer is aligned to
2118 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2120 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2121 * to handle smaller (i.e. degraded) buffer allocations under low- or
2122 * fragmented-memory situations where such reduced allocations, from a
2123 * requested ideal, are allowed.
2125 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2127 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2129 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2130 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2133 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2135 while (*size > min_alloc) {
2136 kbuf = kmalloc(*size, flags);
2141 *size = ALIGN(*size, mtd->writesize);
2145 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2146 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2148 return kmalloc(*size, GFP_KERNEL);
2150 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2152 #ifdef CONFIG_PROC_FS
2154 /*====================================================================*/
2155 /* Support for /proc/mtd */
2157 static int mtd_proc_show(struct seq_file *m, void *v)
2159 struct mtd_info *mtd;
2161 seq_puts(m, "dev: size erasesize name\n");
2162 mutex_lock(&mtd_table_mutex);
2163 mtd_for_each_device(mtd) {
2164 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2165 mtd->index, (unsigned long long)mtd->size,
2166 mtd->erasesize, mtd->name);
2168 mutex_unlock(&mtd_table_mutex);
2171 #endif /* CONFIG_PROC_FS */
2173 /*====================================================================*/
2176 static struct backing_dev_info * __init mtd_bdi_init(char *name)
2178 struct backing_dev_info *bdi;
2181 bdi = bdi_alloc(NUMA_NO_NODE);
2183 return ERR_PTR(-ENOMEM);
2188 * We put '-0' suffix to the name to get the same name format as we
2189 * used to get. Since this is called only once, we get a unique name.
2191 ret = bdi_register(bdi, "%.28s-0", name);
2195 return ret ? ERR_PTR(ret) : bdi;
2198 static struct proc_dir_entry *proc_mtd;
2200 static int __init init_mtd(void)
2204 ret = class_register(&mtd_class);
2208 mtd_bdi = mtd_bdi_init("mtd");
2209 if (IS_ERR(mtd_bdi)) {
2210 ret = PTR_ERR(mtd_bdi);
2214 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2216 ret = init_mtdchar();
2220 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2226 remove_proc_entry("mtd", NULL);
2229 class_unregister(&mtd_class);
2231 pr_err("Error registering mtd class or bdi: %d\n", ret);
2235 static void __exit cleanup_mtd(void)
2237 debugfs_remove_recursive(dfs_dir_mtd);
2240 remove_proc_entry("mtd", NULL);
2241 class_unregister(&mtd_class);
2243 idr_destroy(&mtd_idr);
2246 module_init(init_mtd);
2247 module_exit(cleanup_mtd);
2249 MODULE_LICENSE("GPL");
2250 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2251 MODULE_DESCRIPTION("Core MTD registration and access routines");