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 = dev_name(&mtd->dev);
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)))
621 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
622 * master is an MLC NAND and has a proper pairing scheme defined.
623 * We also reject masters that implement ->_writev() for now, because
624 * NAND controller drivers don't implement this hook, and adding the
625 * SLC -> MLC address/length conversion to this path is useless if we
628 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
629 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
630 !master->pairing || master->_writev))
633 mutex_lock(&mtd_table_mutex);
635 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
644 /* default value if not set by driver */
645 if (mtd->bitflip_threshold == 0)
646 mtd->bitflip_threshold = mtd->ecc_strength;
648 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
649 int ngroups = mtd_pairing_groups(master);
651 mtd->erasesize /= ngroups;
652 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
656 if (is_power_of_2(mtd->erasesize))
657 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
659 mtd->erasesize_shift = 0;
661 if (is_power_of_2(mtd->writesize))
662 mtd->writesize_shift = ffs(mtd->writesize) - 1;
664 mtd->writesize_shift = 0;
666 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
667 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
669 /* Some chips always power up locked. Unlock them now */
670 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
671 error = mtd_unlock(mtd, 0, mtd->size);
672 if (error && error != -EOPNOTSUPP)
674 "%s: unlock failed, writes may not work\n",
676 /* Ignore unlock failures? */
680 /* Caller should have set dev.parent to match the
681 * physical device, if appropriate.
683 mtd->dev.type = &mtd_devtype;
684 mtd->dev.class = &mtd_class;
685 mtd->dev.devt = MTD_DEVT(i);
686 dev_set_name(&mtd->dev, "mtd%d", i);
687 dev_set_drvdata(&mtd->dev, mtd);
688 of_node_get(mtd_get_of_node(mtd));
689 error = device_register(&mtd->dev);
693 /* Add the nvmem provider */
694 error = mtd_nvmem_add(mtd);
698 mtd_debugfs_populate(mtd);
700 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
703 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
704 /* No need to get a refcount on the module containing
705 the notifier, since we hold the mtd_table_mutex */
706 list_for_each_entry(not, &mtd_notifiers, list)
709 mutex_unlock(&mtd_table_mutex);
710 /* We _know_ we aren't being removed, because
711 our caller is still holding us here. So none
712 of this try_ nonsense, and no bitching about it
714 __module_get(THIS_MODULE);
718 device_unregister(&mtd->dev);
720 of_node_put(mtd_get_of_node(mtd));
721 idr_remove(&mtd_idr, i);
723 mutex_unlock(&mtd_table_mutex);
728 * del_mtd_device - unregister an MTD device
729 * @mtd: pointer to MTD device info structure
731 * Remove a device from the list of MTD devices present in the system,
732 * and notify each currently active MTD 'user' of its departure.
733 * Returns zero on success or 1 on failure, which currently will happen
734 * if the requested device does not appear to be present in the list.
737 int del_mtd_device(struct mtd_info *mtd)
740 struct mtd_notifier *not;
742 mutex_lock(&mtd_table_mutex);
744 debugfs_remove_recursive(mtd->dbg.dfs_dir);
746 if (idr_find(&mtd_idr, mtd->index) != mtd) {
751 /* No need to get a refcount on the module containing
752 the notifier, since we hold the mtd_table_mutex */
753 list_for_each_entry(not, &mtd_notifiers, list)
757 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
758 mtd->index, mtd->name, mtd->usecount);
761 /* Try to remove the NVMEM provider */
763 nvmem_unregister(mtd->nvmem);
765 device_unregister(&mtd->dev);
767 idr_remove(&mtd_idr, mtd->index);
768 of_node_put(mtd_get_of_node(mtd));
770 module_put(THIS_MODULE);
775 mutex_unlock(&mtd_table_mutex);
780 * Set a few defaults based on the parent devices, if not provided by the
783 static void mtd_set_dev_defaults(struct mtd_info *mtd)
785 if (mtd->dev.parent) {
786 if (!mtd->owner && mtd->dev.parent->driver)
787 mtd->owner = mtd->dev.parent->driver->owner;
789 mtd->name = dev_name(mtd->dev.parent);
791 pr_debug("mtd device won't show a device symlink in sysfs\n");
794 INIT_LIST_HEAD(&mtd->partitions);
795 mutex_init(&mtd->master.partitions_lock);
799 * mtd_device_parse_register - parse partitions and register an MTD device.
801 * @mtd: the MTD device to register
802 * @types: the list of MTD partition probes to try, see
803 * 'parse_mtd_partitions()' for more information
804 * @parser_data: MTD partition parser-specific data
805 * @parts: fallback partition information to register, if parsing fails;
806 * only valid if %nr_parts > %0
807 * @nr_parts: the number of partitions in parts, if zero then the full
808 * MTD device is registered if no partition info is found
810 * This function aggregates MTD partitions parsing (done by
811 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
812 * basically follows the most common pattern found in many MTD drivers:
814 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
816 * * Then It tries to probe partitions on MTD device @mtd using parsers
817 * specified in @types (if @types is %NULL, then the default list of parsers
818 * is used, see 'parse_mtd_partitions()' for more information). If none are
819 * found this functions tries to fallback to information specified in
821 * * If no partitions were found this function just registers the MTD device
824 * Returns zero in case of success and a negative error code in case of failure.
826 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
827 struct mtd_part_parser_data *parser_data,
828 const struct mtd_partition *parts,
833 mtd_set_dev_defaults(mtd);
835 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
836 ret = add_mtd_device(mtd);
841 /* Prefer parsed partitions over driver-provided fallback */
842 ret = parse_mtd_partitions(mtd, types, parser_data);
846 ret = add_mtd_partitions(mtd, parts, nr_parts);
847 else if (!device_is_registered(&mtd->dev))
848 ret = add_mtd_device(mtd);
856 * FIXME: some drivers unfortunately call this function more than once.
857 * So we have to check if we've already assigned the reboot notifier.
859 * Generally, we can make multiple calls work for most cases, but it
860 * does cause problems with parse_mtd_partitions() above (e.g.,
861 * cmdlineparts will register partitions more than once).
863 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
864 "MTD already registered\n");
865 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
866 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
867 register_reboot_notifier(&mtd->reboot_notifier);
871 if (ret && device_is_registered(&mtd->dev))
876 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
879 * mtd_device_unregister - unregister an existing MTD device.
881 * @master: the MTD device to unregister. This will unregister both the master
882 * and any partitions if registered.
884 int mtd_device_unregister(struct mtd_info *master)
889 unregister_reboot_notifier(&master->reboot_notifier);
891 err = del_mtd_partitions(master);
895 if (!device_is_registered(&master->dev))
898 return del_mtd_device(master);
900 EXPORT_SYMBOL_GPL(mtd_device_unregister);
903 * register_mtd_user - register a 'user' of MTD devices.
904 * @new: pointer to notifier info structure
906 * Registers a pair of callbacks function to be called upon addition
907 * or removal of MTD devices. Causes the 'add' callback to be immediately
908 * invoked for each MTD device currently present in the system.
910 void register_mtd_user (struct mtd_notifier *new)
912 struct mtd_info *mtd;
914 mutex_lock(&mtd_table_mutex);
916 list_add(&new->list, &mtd_notifiers);
918 __module_get(THIS_MODULE);
920 mtd_for_each_device(mtd)
923 mutex_unlock(&mtd_table_mutex);
925 EXPORT_SYMBOL_GPL(register_mtd_user);
928 * unregister_mtd_user - unregister a 'user' of MTD devices.
929 * @old: pointer to notifier info structure
931 * Removes a callback function pair from the list of 'users' to be
932 * notified upon addition or removal of MTD devices. Causes the
933 * 'remove' callback to be immediately invoked for each MTD device
934 * currently present in the system.
936 int unregister_mtd_user (struct mtd_notifier *old)
938 struct mtd_info *mtd;
940 mutex_lock(&mtd_table_mutex);
942 module_put(THIS_MODULE);
944 mtd_for_each_device(mtd)
947 list_del(&old->list);
948 mutex_unlock(&mtd_table_mutex);
951 EXPORT_SYMBOL_GPL(unregister_mtd_user);
954 * get_mtd_device - obtain a validated handle for an MTD device
955 * @mtd: last known address of the required MTD device
956 * @num: internal device number of the required MTD device
958 * Given a number and NULL address, return the num'th entry in the device
959 * table, if any. Given an address and num == -1, search the device table
960 * for a device with that address and return if it's still present. Given
961 * both, return the num'th driver only if its address matches. Return
964 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
966 struct mtd_info *ret = NULL, *other;
969 mutex_lock(&mtd_table_mutex);
972 mtd_for_each_device(other) {
978 } else if (num >= 0) {
979 ret = idr_find(&mtd_idr, num);
980 if (mtd && mtd != ret)
989 err = __get_mtd_device(ret);
993 mutex_unlock(&mtd_table_mutex);
996 EXPORT_SYMBOL_GPL(get_mtd_device);
999 int __get_mtd_device(struct mtd_info *mtd)
1001 struct mtd_info *master = mtd_get_master(mtd);
1004 if (!try_module_get(master->owner))
1007 if (master->_get_device) {
1008 err = master->_get_device(mtd);
1011 module_put(master->owner);
1016 while (mtd->parent) {
1023 EXPORT_SYMBOL_GPL(__get_mtd_device);
1026 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1028 * @name: MTD device name to open
1030 * This function returns MTD device description structure in case of
1031 * success and an error code in case of failure.
1033 struct mtd_info *get_mtd_device_nm(const char *name)
1036 struct mtd_info *mtd = NULL, *other;
1038 mutex_lock(&mtd_table_mutex);
1040 mtd_for_each_device(other) {
1041 if (!strcmp(name, other->name)) {
1050 err = __get_mtd_device(mtd);
1054 mutex_unlock(&mtd_table_mutex);
1058 mutex_unlock(&mtd_table_mutex);
1059 return ERR_PTR(err);
1061 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1063 void put_mtd_device(struct mtd_info *mtd)
1065 mutex_lock(&mtd_table_mutex);
1066 __put_mtd_device(mtd);
1067 mutex_unlock(&mtd_table_mutex);
1070 EXPORT_SYMBOL_GPL(put_mtd_device);
1072 void __put_mtd_device(struct mtd_info *mtd)
1074 struct mtd_info *master = mtd_get_master(mtd);
1076 while (mtd->parent) {
1078 BUG_ON(mtd->usecount < 0);
1082 if (master->_put_device)
1083 master->_put_device(master);
1085 module_put(master->owner);
1087 EXPORT_SYMBOL_GPL(__put_mtd_device);
1090 * Erase is an synchronous operation. Device drivers are epected to return a
1091 * negative error code if the operation failed and update instr->fail_addr
1092 * to point the portion that was not properly erased.
1094 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1096 struct mtd_info *master = mtd_get_master(mtd);
1097 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1098 struct erase_info adjinstr;
1101 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1104 if (!mtd->erasesize || !master->_erase)
1107 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1109 if (!(mtd->flags & MTD_WRITEABLE))
1115 ledtrig_mtd_activity();
1117 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1118 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1120 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1121 master->erasesize) -
1125 adjinstr.addr += mst_ofs;
1127 ret = master->_erase(master, &adjinstr);
1129 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1130 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1131 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1132 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1134 instr->fail_addr *= mtd->erasesize;
1140 EXPORT_SYMBOL_GPL(mtd_erase);
1143 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1145 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1146 void **virt, resource_size_t *phys)
1148 struct mtd_info *master = mtd_get_master(mtd);
1154 if (!master->_point)
1156 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1161 from = mtd_get_master_ofs(mtd, from);
1162 return master->_point(master, from, len, retlen, virt, phys);
1164 EXPORT_SYMBOL_GPL(mtd_point);
1166 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1167 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1169 struct mtd_info *master = mtd_get_master(mtd);
1171 if (!master->_unpoint)
1173 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1177 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1179 EXPORT_SYMBOL_GPL(mtd_unpoint);
1182 * Allow NOMMU mmap() to directly map the device (if not NULL)
1183 * - return the address to which the offset maps
1184 * - return -ENOSYS to indicate refusal to do the mapping
1186 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1187 unsigned long offset, unsigned long flags)
1193 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1196 if (retlen != len) {
1197 mtd_unpoint(mtd, offset, retlen);
1200 return (unsigned long)virt;
1202 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1204 static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1205 const struct mtd_ecc_stats *old_stats)
1207 struct mtd_ecc_stats diff;
1212 diff = master->ecc_stats;
1213 diff.failed -= old_stats->failed;
1214 diff.corrected -= old_stats->corrected;
1216 while (mtd->parent) {
1217 mtd->ecc_stats.failed += diff.failed;
1218 mtd->ecc_stats.corrected += diff.corrected;
1223 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1226 struct mtd_oob_ops ops = {
1232 ret = mtd_read_oob(mtd, from, &ops);
1233 *retlen = ops.retlen;
1237 EXPORT_SYMBOL_GPL(mtd_read);
1239 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1242 struct mtd_oob_ops ops = {
1244 .datbuf = (u8 *)buf,
1248 ret = mtd_write_oob(mtd, to, &ops);
1249 *retlen = ops.retlen;
1253 EXPORT_SYMBOL_GPL(mtd_write);
1256 * In blackbox flight recorder like scenarios we want to make successful writes
1257 * in interrupt context. panic_write() is only intended to be called when its
1258 * known the kernel is about to panic and we need the write to succeed. Since
1259 * the kernel is not going to be running for much longer, this function can
1260 * break locks and delay to ensure the write succeeds (but not sleep).
1262 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1265 struct mtd_info *master = mtd_get_master(mtd);
1268 if (!master->_panic_write)
1270 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1272 if (!(mtd->flags & MTD_WRITEABLE))
1276 if (!mtd->oops_panic_write)
1277 mtd->oops_panic_write = true;
1279 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1282 EXPORT_SYMBOL_GPL(mtd_panic_write);
1284 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1285 struct mtd_oob_ops *ops)
1288 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1289 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1298 if (offs < 0 || offs + ops->len > mtd->size)
1304 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1307 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1308 mtd_div_by_ws(offs, mtd)) *
1309 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1310 if (ops->ooblen > maxooblen)
1317 static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1318 struct mtd_oob_ops *ops)
1320 struct mtd_info *master = mtd_get_master(mtd);
1323 from = mtd_get_master_ofs(mtd, from);
1324 if (master->_read_oob)
1325 ret = master->_read_oob(master, from, ops);
1327 ret = master->_read(master, from, ops->len, &ops->retlen,
1333 static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1334 struct mtd_oob_ops *ops)
1336 struct mtd_info *master = mtd_get_master(mtd);
1339 to = mtd_get_master_ofs(mtd, to);
1340 if (master->_write_oob)
1341 ret = master->_write_oob(master, to, ops);
1343 ret = master->_write(master, to, ops->len, &ops->retlen,
1349 static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1350 struct mtd_oob_ops *ops)
1352 struct mtd_info *master = mtd_get_master(mtd);
1353 int ngroups = mtd_pairing_groups(master);
1354 int npairs = mtd_wunit_per_eb(master) / ngroups;
1355 struct mtd_oob_ops adjops = *ops;
1356 unsigned int wunit, oobavail;
1357 struct mtd_pairing_info info;
1358 int max_bitflips = 0;
1362 ebofs = mtd_mod_by_eb(start, mtd);
1363 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1365 info.pair = mtd_div_by_ws(ebofs, mtd);
1366 pageofs = mtd_mod_by_ws(ebofs, mtd);
1367 oobavail = mtd_oobavail(mtd, ops);
1369 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1372 if (info.pair >= npairs) {
1374 base += master->erasesize;
1377 wunit = mtd_pairing_info_to_wunit(master, &info);
1378 pos = mtd_wunit_to_offset(mtd, base, wunit);
1380 adjops.len = ops->len - ops->retlen;
1381 if (adjops.len > mtd->writesize - pageofs)
1382 adjops.len = mtd->writesize - pageofs;
1384 adjops.ooblen = ops->ooblen - ops->oobretlen;
1385 if (adjops.ooblen > oobavail - adjops.ooboffs)
1386 adjops.ooblen = oobavail - adjops.ooboffs;
1389 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1391 max_bitflips = max(max_bitflips, ret);
1393 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1399 max_bitflips = max(max_bitflips, ret);
1400 ops->retlen += adjops.retlen;
1401 ops->oobretlen += adjops.oobretlen;
1402 adjops.datbuf += adjops.retlen;
1403 adjops.oobbuf += adjops.oobretlen;
1409 return max_bitflips;
1412 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1414 struct mtd_info *master = mtd_get_master(mtd);
1415 struct mtd_ecc_stats old_stats = master->ecc_stats;
1418 ops->retlen = ops->oobretlen = 0;
1420 ret_code = mtd_check_oob_ops(mtd, from, ops);
1424 ledtrig_mtd_activity();
1426 /* Check the validity of a potential fallback on mtd->_read */
1427 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1430 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1431 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1433 ret_code = mtd_read_oob_std(mtd, from, ops);
1435 mtd_update_ecc_stats(mtd, master, &old_stats);
1438 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1439 * similar to mtd->_read(), returning a non-negative integer
1440 * representing max bitflips. In other cases, mtd->_read_oob() may
1441 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1443 if (unlikely(ret_code < 0))
1445 if (mtd->ecc_strength == 0)
1446 return 0; /* device lacks ecc */
1447 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1449 EXPORT_SYMBOL_GPL(mtd_read_oob);
1451 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1452 struct mtd_oob_ops *ops)
1454 struct mtd_info *master = mtd_get_master(mtd);
1457 ops->retlen = ops->oobretlen = 0;
1459 if (!(mtd->flags & MTD_WRITEABLE))
1462 ret = mtd_check_oob_ops(mtd, to, ops);
1466 ledtrig_mtd_activity();
1468 /* Check the validity of a potential fallback on mtd->_write */
1469 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1472 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1473 return mtd_io_emulated_slc(mtd, to, false, ops);
1475 return mtd_write_oob_std(mtd, to, ops);
1477 EXPORT_SYMBOL_GPL(mtd_write_oob);
1480 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1481 * @mtd: MTD device structure
1482 * @section: ECC section. Depending on the layout you may have all the ECC
1483 * bytes stored in a single contiguous section, or one section
1484 * per ECC chunk (and sometime several sections for a single ECC
1486 * @oobecc: OOB region struct filled with the appropriate ECC position
1489 * This function returns ECC section information in the OOB area. If you want
1490 * to get all the ECC bytes information, then you should call
1491 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1493 * Returns zero on success, a negative error code otherwise.
1495 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1496 struct mtd_oob_region *oobecc)
1498 struct mtd_info *master = mtd_get_master(mtd);
1500 memset(oobecc, 0, sizeof(*oobecc));
1502 if (!master || section < 0)
1505 if (!master->ooblayout || !master->ooblayout->ecc)
1508 return master->ooblayout->ecc(master, section, oobecc);
1510 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1513 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1515 * @mtd: MTD device structure
1516 * @section: Free section you are interested in. Depending on the layout
1517 * you may have all the free bytes stored in a single contiguous
1518 * section, or one section per ECC chunk plus an extra section
1519 * for the remaining bytes (or other funky layout).
1520 * @oobfree: OOB region struct filled with the appropriate free position
1523 * This function returns free bytes position in the OOB area. If you want
1524 * to get all the free bytes information, then you should call
1525 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1527 * Returns zero on success, a negative error code otherwise.
1529 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1530 struct mtd_oob_region *oobfree)
1532 struct mtd_info *master = mtd_get_master(mtd);
1534 memset(oobfree, 0, sizeof(*oobfree));
1536 if (!master || section < 0)
1539 if (!master->ooblayout || !master->ooblayout->free)
1542 return master->ooblayout->free(master, section, oobfree);
1544 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1547 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1548 * @mtd: mtd info structure
1549 * @byte: the byte we are searching for
1550 * @sectionp: pointer where the section id will be stored
1551 * @oobregion: used to retrieve the ECC position
1552 * @iter: iterator function. Should be either mtd_ooblayout_free or
1553 * mtd_ooblayout_ecc depending on the region type you're searching for
1555 * This function returns the section id and oobregion information of a
1556 * specific byte. For example, say you want to know where the 4th ECC byte is
1557 * stored, you'll use:
1559 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1561 * Returns zero on success, a negative error code otherwise.
1563 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1564 int *sectionp, struct mtd_oob_region *oobregion,
1565 int (*iter)(struct mtd_info *,
1567 struct mtd_oob_region *oobregion))
1569 int pos = 0, ret, section = 0;
1571 memset(oobregion, 0, sizeof(*oobregion));
1574 ret = iter(mtd, section, oobregion);
1578 if (pos + oobregion->length > byte)
1581 pos += oobregion->length;
1586 * Adjust region info to make it start at the beginning at the
1589 oobregion->offset += byte - pos;
1590 oobregion->length -= byte - pos;
1591 *sectionp = section;
1597 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1599 * @mtd: mtd info structure
1600 * @eccbyte: the byte we are searching for
1601 * @sectionp: pointer where the section id will be stored
1602 * @oobregion: OOB region information
1604 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1607 * Returns zero on success, a negative error code otherwise.
1609 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1611 struct mtd_oob_region *oobregion)
1613 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1616 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1619 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1620 * @mtd: mtd info structure
1621 * @buf: destination buffer to store OOB bytes
1622 * @oobbuf: OOB buffer
1623 * @start: first byte to retrieve
1624 * @nbytes: number of bytes to retrieve
1625 * @iter: section iterator
1627 * Extract bytes attached to a specific category (ECC or free)
1628 * from the OOB buffer and copy them into buf.
1630 * Returns zero on success, a negative error code otherwise.
1632 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1633 const u8 *oobbuf, int start, int nbytes,
1634 int (*iter)(struct mtd_info *,
1636 struct mtd_oob_region *oobregion))
1638 struct mtd_oob_region oobregion;
1641 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1647 cnt = min_t(int, nbytes, oobregion.length);
1648 memcpy(buf, oobbuf + oobregion.offset, cnt);
1655 ret = iter(mtd, ++section, &oobregion);
1662 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1663 * @mtd: mtd info structure
1664 * @buf: source buffer to get OOB bytes from
1665 * @oobbuf: OOB buffer
1666 * @start: first OOB byte to set
1667 * @nbytes: number of OOB bytes to set
1668 * @iter: section iterator
1670 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1671 * is selected by passing the appropriate iterator.
1673 * Returns zero on success, a negative error code otherwise.
1675 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1676 u8 *oobbuf, int start, int nbytes,
1677 int (*iter)(struct mtd_info *,
1679 struct mtd_oob_region *oobregion))
1681 struct mtd_oob_region oobregion;
1684 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1690 cnt = min_t(int, nbytes, oobregion.length);
1691 memcpy(oobbuf + oobregion.offset, buf, cnt);
1698 ret = iter(mtd, ++section, &oobregion);
1705 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1706 * @mtd: mtd info structure
1707 * @iter: category iterator
1709 * Count the number of bytes in a given category.
1711 * Returns a positive value on success, a negative error code otherwise.
1713 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1714 int (*iter)(struct mtd_info *,
1716 struct mtd_oob_region *oobregion))
1718 struct mtd_oob_region oobregion;
1719 int section = 0, ret, nbytes = 0;
1722 ret = iter(mtd, section++, &oobregion);
1729 nbytes += oobregion.length;
1736 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1737 * @mtd: mtd info structure
1738 * @eccbuf: destination buffer to store ECC bytes
1739 * @oobbuf: OOB buffer
1740 * @start: first ECC byte to retrieve
1741 * @nbytes: number of ECC bytes to retrieve
1743 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1745 * Returns zero on success, a negative error code otherwise.
1747 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1748 const u8 *oobbuf, int start, int nbytes)
1750 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1753 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1756 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1757 * @mtd: mtd info structure
1758 * @eccbuf: source buffer to get ECC bytes from
1759 * @oobbuf: OOB buffer
1760 * @start: first ECC byte to set
1761 * @nbytes: number of ECC bytes to set
1763 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1765 * Returns zero on success, a negative error code otherwise.
1767 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1768 u8 *oobbuf, int start, int nbytes)
1770 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1773 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1776 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1777 * @mtd: mtd info structure
1778 * @databuf: destination buffer to store ECC bytes
1779 * @oobbuf: OOB buffer
1780 * @start: first ECC byte to retrieve
1781 * @nbytes: number of ECC bytes to retrieve
1783 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1785 * Returns zero on success, a negative error code otherwise.
1787 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1788 const u8 *oobbuf, int start, int nbytes)
1790 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1791 mtd_ooblayout_free);
1793 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1796 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1797 * @mtd: mtd info structure
1798 * @databuf: source buffer to get data bytes from
1799 * @oobbuf: OOB buffer
1800 * @start: first ECC byte to set
1801 * @nbytes: number of ECC bytes to set
1803 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
1805 * Returns zero on success, a negative error code otherwise.
1807 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1808 u8 *oobbuf, int start, int nbytes)
1810 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1811 mtd_ooblayout_free);
1813 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1816 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1817 * @mtd: mtd info structure
1819 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1821 * Returns zero on success, a negative error code otherwise.
1823 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1825 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1827 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1830 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1831 * @mtd: mtd info structure
1833 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1835 * Returns zero on success, a negative error code otherwise.
1837 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1839 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1841 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1844 * Method to access the protection register area, present in some flash
1845 * devices. The user data is one time programmable but the factory data is read
1848 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1849 struct otp_info *buf)
1851 struct mtd_info *master = mtd_get_master(mtd);
1853 if (!master->_get_fact_prot_info)
1857 return master->_get_fact_prot_info(master, len, retlen, buf);
1859 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1861 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1862 size_t *retlen, u_char *buf)
1864 struct mtd_info *master = mtd_get_master(mtd);
1867 if (!master->_read_fact_prot_reg)
1871 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
1873 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1875 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1876 struct otp_info *buf)
1878 struct mtd_info *master = mtd_get_master(mtd);
1880 if (!master->_get_user_prot_info)
1884 return master->_get_user_prot_info(master, len, retlen, buf);
1886 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1888 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1889 size_t *retlen, u_char *buf)
1891 struct mtd_info *master = mtd_get_master(mtd);
1894 if (!master->_read_user_prot_reg)
1898 return master->_read_user_prot_reg(master, from, len, retlen, buf);
1900 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1902 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1903 size_t *retlen, u_char *buf)
1905 struct mtd_info *master = mtd_get_master(mtd);
1909 if (!master->_write_user_prot_reg)
1913 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
1918 * If no data could be written at all, we are out of memory and
1919 * must return -ENOSPC.
1921 return (*retlen) ? 0 : -ENOSPC;
1923 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1925 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1927 struct mtd_info *master = mtd_get_master(mtd);
1929 if (!master->_lock_user_prot_reg)
1933 return master->_lock_user_prot_reg(master, from, len);
1935 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1937 /* Chip-supported device locking */
1938 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1940 struct mtd_info *master = mtd_get_master(mtd);
1944 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1949 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1950 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1951 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1954 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
1956 EXPORT_SYMBOL_GPL(mtd_lock);
1958 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1960 struct mtd_info *master = mtd_get_master(mtd);
1962 if (!master->_unlock)
1964 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1969 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1970 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1971 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1974 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
1976 EXPORT_SYMBOL_GPL(mtd_unlock);
1978 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1980 struct mtd_info *master = mtd_get_master(mtd);
1982 if (!master->_is_locked)
1984 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1989 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1990 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1991 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1994 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
1996 EXPORT_SYMBOL_GPL(mtd_is_locked);
1998 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2000 struct mtd_info *master = mtd_get_master(mtd);
2002 if (ofs < 0 || ofs >= mtd->size)
2004 if (!master->_block_isreserved)
2007 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2008 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2010 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2012 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2014 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2016 struct mtd_info *master = mtd_get_master(mtd);
2018 if (ofs < 0 || ofs >= mtd->size)
2020 if (!master->_block_isbad)
2023 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2024 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2026 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2028 EXPORT_SYMBOL_GPL(mtd_block_isbad);
2030 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2032 struct mtd_info *master = mtd_get_master(mtd);
2035 if (!master->_block_markbad)
2037 if (ofs < 0 || ofs >= mtd->size)
2039 if (!(mtd->flags & MTD_WRITEABLE))
2042 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2043 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2045 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2049 while (mtd->parent) {
2050 mtd->ecc_stats.badblocks++;
2056 EXPORT_SYMBOL_GPL(mtd_block_markbad);
2059 * default_mtd_writev - the default writev method
2060 * @mtd: mtd device description object pointer
2061 * @vecs: the vectors to write
2062 * @count: count of vectors in @vecs
2063 * @to: the MTD device offset to write to
2064 * @retlen: on exit contains the count of bytes written to the MTD device.
2066 * This function returns zero in case of success and a negative error code in
2069 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2070 unsigned long count, loff_t to, size_t *retlen)
2073 size_t totlen = 0, thislen;
2076 for (i = 0; i < count; i++) {
2077 if (!vecs[i].iov_len)
2079 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2082 if (ret || thislen != vecs[i].iov_len)
2084 to += vecs[i].iov_len;
2091 * mtd_writev - the vector-based MTD write method
2092 * @mtd: mtd device description object pointer
2093 * @vecs: the vectors to write
2094 * @count: count of vectors in @vecs
2095 * @to: the MTD device offset to write to
2096 * @retlen: on exit contains the count of bytes written to the MTD device.
2098 * This function returns zero in case of success and a negative error code in
2101 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2102 unsigned long count, loff_t to, size_t *retlen)
2104 struct mtd_info *master = mtd_get_master(mtd);
2107 if (!(mtd->flags & MTD_WRITEABLE))
2110 if (!master->_writev)
2111 return default_mtd_writev(mtd, vecs, count, to, retlen);
2113 return master->_writev(master, vecs, count,
2114 mtd_get_master_ofs(mtd, to), retlen);
2116 EXPORT_SYMBOL_GPL(mtd_writev);
2119 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2120 * @mtd: mtd device description object pointer
2121 * @size: a pointer to the ideal or maximum size of the allocation, points
2122 * to the actual allocation size on success.
2124 * This routine attempts to allocate a contiguous kernel buffer up to
2125 * the specified size, backing off the size of the request exponentially
2126 * until the request succeeds or until the allocation size falls below
2127 * the system page size. This attempts to make sure it does not adversely
2128 * impact system performance, so when allocating more than one page, we
2129 * ask the memory allocator to avoid re-trying, swapping, writing back
2130 * or performing I/O.
2132 * Note, this function also makes sure that the allocated buffer is aligned to
2133 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2135 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2136 * to handle smaller (i.e. degraded) buffer allocations under low- or
2137 * fragmented-memory situations where such reduced allocations, from a
2138 * requested ideal, are allowed.
2140 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2142 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2144 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2145 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2148 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2150 while (*size > min_alloc) {
2151 kbuf = kmalloc(*size, flags);
2156 *size = ALIGN(*size, mtd->writesize);
2160 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2161 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2163 return kmalloc(*size, GFP_KERNEL);
2165 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2167 #ifdef CONFIG_PROC_FS
2169 /*====================================================================*/
2170 /* Support for /proc/mtd */
2172 static int mtd_proc_show(struct seq_file *m, void *v)
2174 struct mtd_info *mtd;
2176 seq_puts(m, "dev: size erasesize name\n");
2177 mutex_lock(&mtd_table_mutex);
2178 mtd_for_each_device(mtd) {
2179 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2180 mtd->index, (unsigned long long)mtd->size,
2181 mtd->erasesize, mtd->name);
2183 mutex_unlock(&mtd_table_mutex);
2186 #endif /* CONFIG_PROC_FS */
2188 /*====================================================================*/
2191 static struct backing_dev_info * __init mtd_bdi_init(char *name)
2193 struct backing_dev_info *bdi;
2196 bdi = bdi_alloc(NUMA_NO_NODE);
2198 return ERR_PTR(-ENOMEM);
2201 * We put '-0' suffix to the name to get the same name format as we
2202 * used to get. Since this is called only once, we get a unique name.
2204 ret = bdi_register(bdi, "%.28s-0", name);
2208 return ret ? ERR_PTR(ret) : bdi;
2211 static struct proc_dir_entry *proc_mtd;
2213 static int __init init_mtd(void)
2217 ret = class_register(&mtd_class);
2221 mtd_bdi = mtd_bdi_init("mtd");
2222 if (IS_ERR(mtd_bdi)) {
2223 ret = PTR_ERR(mtd_bdi);
2227 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2229 ret = init_mtdchar();
2233 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2239 remove_proc_entry("mtd", NULL);
2242 class_unregister(&mtd_class);
2244 pr_err("Error registering mtd class or bdi: %d\n", ret);
2248 static void __exit cleanup_mtd(void)
2250 debugfs_remove_recursive(dfs_dir_mtd);
2253 remove_proc_entry("mtd", NULL);
2254 class_unregister(&mtd_class);
2256 idr_destroy(&mtd_idr);
2259 module_init(init_mtd);
2260 module_exit(cleanup_mtd);
2262 MODULE_LICENSE("GPL");
2263 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2264 MODULE_DESCRIPTION("Core MTD registration and access routines");