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 #define MTD_DEVICE_ATTR_RO(name) \
100 static DEVICE_ATTR(name, 0444, mtd_##name##_show, NULL)
102 #define MTD_DEVICE_ATTR_RW(name) \
103 static DEVICE_ATTR(name, 0644, mtd_##name##_show, mtd_##name##_store)
105 static ssize_t mtd_type_show(struct device *dev,
106 struct device_attribute *attr, char *buf)
108 struct mtd_info *mtd = dev_get_drvdata(dev);
133 case MTD_MLCNANDFLASH:
140 return sysfs_emit(buf, "%s\n", type);
142 MTD_DEVICE_ATTR_RO(type);
144 static ssize_t mtd_flags_show(struct device *dev,
145 struct device_attribute *attr, char *buf)
147 struct mtd_info *mtd = dev_get_drvdata(dev);
149 return sysfs_emit(buf, "0x%lx\n", (unsigned long)mtd->flags);
151 MTD_DEVICE_ATTR_RO(flags);
153 static ssize_t mtd_size_show(struct device *dev,
154 struct device_attribute *attr, char *buf)
156 struct mtd_info *mtd = dev_get_drvdata(dev);
158 return sysfs_emit(buf, "%llu\n", (unsigned long long)mtd->size);
160 MTD_DEVICE_ATTR_RO(size);
162 static ssize_t mtd_erasesize_show(struct device *dev,
163 struct device_attribute *attr, char *buf)
165 struct mtd_info *mtd = dev_get_drvdata(dev);
167 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize);
169 MTD_DEVICE_ATTR_RO(erasesize);
171 static ssize_t mtd_writesize_show(struct device *dev,
172 struct device_attribute *attr, char *buf)
174 struct mtd_info *mtd = dev_get_drvdata(dev);
176 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->writesize);
178 MTD_DEVICE_ATTR_RO(writesize);
180 static ssize_t mtd_subpagesize_show(struct device *dev,
181 struct device_attribute *attr, char *buf)
183 struct mtd_info *mtd = dev_get_drvdata(dev);
184 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
186 return sysfs_emit(buf, "%u\n", subpagesize);
188 MTD_DEVICE_ATTR_RO(subpagesize);
190 static ssize_t mtd_oobsize_show(struct device *dev,
191 struct device_attribute *attr, char *buf)
193 struct mtd_info *mtd = dev_get_drvdata(dev);
195 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->oobsize);
197 MTD_DEVICE_ATTR_RO(oobsize);
199 static ssize_t mtd_oobavail_show(struct device *dev,
200 struct device_attribute *attr, char *buf)
202 struct mtd_info *mtd = dev_get_drvdata(dev);
204 return sysfs_emit(buf, "%u\n", mtd->oobavail);
206 MTD_DEVICE_ATTR_RO(oobavail);
208 static ssize_t mtd_numeraseregions_show(struct device *dev,
209 struct device_attribute *attr, char *buf)
211 struct mtd_info *mtd = dev_get_drvdata(dev);
213 return sysfs_emit(buf, "%u\n", mtd->numeraseregions);
215 MTD_DEVICE_ATTR_RO(numeraseregions);
217 static ssize_t mtd_name_show(struct device *dev,
218 struct device_attribute *attr, char *buf)
220 struct mtd_info *mtd = dev_get_drvdata(dev);
222 return sysfs_emit(buf, "%s\n", mtd->name);
224 MTD_DEVICE_ATTR_RO(name);
226 static ssize_t mtd_ecc_strength_show(struct device *dev,
227 struct device_attribute *attr, char *buf)
229 struct mtd_info *mtd = dev_get_drvdata(dev);
231 return sysfs_emit(buf, "%u\n", mtd->ecc_strength);
233 MTD_DEVICE_ATTR_RO(ecc_strength);
235 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
236 struct device_attribute *attr,
239 struct mtd_info *mtd = dev_get_drvdata(dev);
241 return sysfs_emit(buf, "%u\n", mtd->bitflip_threshold);
244 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
245 struct device_attribute *attr,
246 const char *buf, size_t count)
248 struct mtd_info *mtd = dev_get_drvdata(dev);
249 unsigned int bitflip_threshold;
252 retval = kstrtouint(buf, 0, &bitflip_threshold);
256 mtd->bitflip_threshold = bitflip_threshold;
259 MTD_DEVICE_ATTR_RW(bitflip_threshold);
261 static ssize_t mtd_ecc_step_size_show(struct device *dev,
262 struct device_attribute *attr, char *buf)
264 struct mtd_info *mtd = dev_get_drvdata(dev);
266 return sysfs_emit(buf, "%u\n", mtd->ecc_step_size);
269 MTD_DEVICE_ATTR_RO(ecc_step_size);
271 static ssize_t mtd_corrected_bits_show(struct device *dev,
272 struct device_attribute *attr, char *buf)
274 struct mtd_info *mtd = dev_get_drvdata(dev);
275 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
277 return sysfs_emit(buf, "%u\n", ecc_stats->corrected);
279 MTD_DEVICE_ATTR_RO(corrected_bits); /* ecc stats corrected */
281 static ssize_t mtd_ecc_failures_show(struct device *dev,
282 struct device_attribute *attr, char *buf)
284 struct mtd_info *mtd = dev_get_drvdata(dev);
285 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
287 return sysfs_emit(buf, "%u\n", ecc_stats->failed);
289 MTD_DEVICE_ATTR_RO(ecc_failures); /* ecc stats errors */
291 static ssize_t mtd_bad_blocks_show(struct device *dev,
292 struct device_attribute *attr, char *buf)
294 struct mtd_info *mtd = dev_get_drvdata(dev);
295 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
297 return sysfs_emit(buf, "%u\n", ecc_stats->badblocks);
299 MTD_DEVICE_ATTR_RO(bad_blocks);
301 static ssize_t mtd_bbt_blocks_show(struct device *dev,
302 struct device_attribute *attr, char *buf)
304 struct mtd_info *mtd = dev_get_drvdata(dev);
305 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
307 return sysfs_emit(buf, "%u\n", ecc_stats->bbtblocks);
309 MTD_DEVICE_ATTR_RO(bbt_blocks);
311 static struct attribute *mtd_attrs[] = {
313 &dev_attr_flags.attr,
315 &dev_attr_erasesize.attr,
316 &dev_attr_writesize.attr,
317 &dev_attr_subpagesize.attr,
318 &dev_attr_oobsize.attr,
319 &dev_attr_oobavail.attr,
320 &dev_attr_numeraseregions.attr,
322 &dev_attr_ecc_strength.attr,
323 &dev_attr_ecc_step_size.attr,
324 &dev_attr_corrected_bits.attr,
325 &dev_attr_ecc_failures.attr,
326 &dev_attr_bad_blocks.attr,
327 &dev_attr_bbt_blocks.attr,
328 &dev_attr_bitflip_threshold.attr,
331 ATTRIBUTE_GROUPS(mtd);
333 static const struct device_type mtd_devtype = {
335 .groups = mtd_groups,
336 .release = mtd_release,
339 static bool mtd_expert_analysis_mode;
341 #ifdef CONFIG_DEBUG_FS
342 bool mtd_check_expert_analysis_mode(void)
344 const char *mtd_expert_analysis_warning =
345 "Bad block checks have been entirely disabled.\n"
346 "This is only reserved for post-mortem forensics and debug purposes.\n"
347 "Never enable this mode if you do not know what you are doing!\n";
349 return WARN_ONCE(mtd_expert_analysis_mode, mtd_expert_analysis_warning);
351 EXPORT_SYMBOL_GPL(mtd_check_expert_analysis_mode);
354 static struct dentry *dfs_dir_mtd;
356 static void mtd_debugfs_populate(struct mtd_info *mtd)
358 struct device *dev = &mtd->dev;
360 if (IS_ERR_OR_NULL(dfs_dir_mtd))
363 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
367 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
371 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
372 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
374 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
377 return NOMMU_MAP_COPY;
380 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
383 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
386 struct mtd_info *mtd;
388 mtd = container_of(n, struct mtd_info, reboot_notifier);
395 * mtd_wunit_to_pairing_info - get pairing information of a wunit
396 * @mtd: pointer to new MTD device info structure
397 * @wunit: write unit we are interested in
398 * @info: returned pairing information
400 * Retrieve pairing information associated to the wunit.
401 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
402 * paired together, and where programming a page may influence the page it is
404 * The notion of page is replaced by the term wunit (write-unit) to stay
405 * consistent with the ->writesize field.
407 * The @wunit argument can be extracted from an absolute offset using
408 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
411 * From the pairing info the MTD user can find all the wunits paired with
412 * @wunit using the following loop:
414 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
416 * mtd_pairing_info_to_wunit(mtd, &info);
420 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
421 struct mtd_pairing_info *info)
423 struct mtd_info *master = mtd_get_master(mtd);
424 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
426 if (wunit < 0 || wunit >= npairs)
429 if (master->pairing && master->pairing->get_info)
430 return master->pairing->get_info(master, wunit, info);
437 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
440 * mtd_pairing_info_to_wunit - get wunit from pairing information
441 * @mtd: pointer to new MTD device info structure
442 * @info: pairing information struct
444 * Returns a positive number representing the wunit associated to the info
445 * struct, or a negative error code.
447 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
448 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
451 * It can also be used to only program the first page of each pair (i.e.
452 * page attached to group 0), which allows one to use an MLC NAND in
453 * software-emulated SLC mode:
456 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
457 * for (info.pair = 0; info.pair < npairs; info.pair++) {
458 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
459 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
460 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
463 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
464 const struct mtd_pairing_info *info)
466 struct mtd_info *master = mtd_get_master(mtd);
467 int ngroups = mtd_pairing_groups(master);
468 int npairs = mtd_wunit_per_eb(master) / ngroups;
470 if (!info || info->pair < 0 || info->pair >= npairs ||
471 info->group < 0 || info->group >= ngroups)
474 if (master->pairing && master->pairing->get_wunit)
475 return mtd->pairing->get_wunit(master, info);
479 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
482 * mtd_pairing_groups - get the number of pairing groups
483 * @mtd: pointer to new MTD device info structure
485 * Returns the number of pairing groups.
487 * This number is usually equal to the number of bits exposed by a single
488 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
489 * to iterate over all pages of a given pair.
491 int mtd_pairing_groups(struct mtd_info *mtd)
493 struct mtd_info *master = mtd_get_master(mtd);
495 if (!master->pairing || !master->pairing->ngroups)
498 return master->pairing->ngroups;
500 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
502 static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
503 void *val, size_t bytes)
505 struct mtd_info *mtd = priv;
509 err = mtd_read(mtd, offset, bytes, &retlen, val);
510 if (err && err != -EUCLEAN)
513 return retlen == bytes ? 0 : -EIO;
516 static int mtd_nvmem_add(struct mtd_info *mtd)
518 struct device_node *node = mtd_get_of_node(mtd);
519 struct nvmem_config config = {};
522 config.dev = &mtd->dev;
523 config.name = dev_name(&mtd->dev);
524 config.owner = THIS_MODULE;
525 config.reg_read = mtd_nvmem_reg_read;
526 config.size = mtd->size;
527 config.word_size = 1;
529 config.read_only = true;
530 config.root_only = true;
531 config.ignore_wp = true;
532 config.no_of_node = !of_device_is_compatible(node, "nvmem-cells");
535 mtd->nvmem = nvmem_register(&config);
536 if (IS_ERR(mtd->nvmem)) {
537 /* Just ignore if there is no NVMEM support in the kernel */
538 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
541 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
542 return PTR_ERR(mtd->nvmem);
549 static void mtd_check_of_node(struct mtd_info *mtd)
551 struct device_node *partitions, *parent_dn, *mtd_dn = NULL;
552 const char *pname, *prefix = "partition-";
553 int plen, mtd_name_len, offset, prefix_len;
554 struct mtd_info *parent;
557 /* Check if MTD already has a device node */
558 if (dev_of_node(&mtd->dev))
561 /* Check if a partitions node exist */
562 if (!mtd_is_partition(mtd))
564 parent = mtd->parent;
565 parent_dn = of_node_get(dev_of_node(&parent->dev));
569 partitions = of_get_child_by_name(parent_dn, "partitions");
573 prefix_len = strlen(prefix);
574 mtd_name_len = strlen(mtd->name);
576 /* Search if a partition is defined with the same name */
577 for_each_child_of_node(partitions, mtd_dn) {
580 /* Skip partition with no/wrong prefix */
581 if (!of_node_name_prefix(mtd_dn, "partition-"))
584 /* Label have priority. Check that first */
585 if (of_property_read_string(mtd_dn, "label", &pname)) {
586 of_property_read_string(mtd_dn, "name", &pname);
590 plen = strlen(pname) - offset;
591 if (plen == mtd_name_len &&
592 !strncmp(mtd->name, pname + offset, plen)) {
599 goto exit_partitions;
601 /* Set of_node only for nvmem */
602 if (of_device_is_compatible(mtd_dn, "nvmem-cells"))
603 mtd_set_of_node(mtd, mtd_dn);
606 of_node_put(partitions);
608 of_node_put(parent_dn);
612 * add_mtd_device - register an MTD device
613 * @mtd: pointer to new MTD device info structure
615 * Add a device to the list of MTD devices present in the system, and
616 * notify each currently active MTD 'user' of its arrival. Returns
617 * zero on success or non-zero on failure.
620 int add_mtd_device(struct mtd_info *mtd)
622 struct device_node *np = mtd_get_of_node(mtd);
623 struct mtd_info *master = mtd_get_master(mtd);
624 struct mtd_notifier *not;
628 * May occur, for instance, on buggy drivers which call
629 * mtd_device_parse_register() multiple times on the same master MTD,
630 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
632 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
635 BUG_ON(mtd->writesize == 0);
638 * MTD drivers should implement ->_{write,read}() or
639 * ->_{write,read}_oob(), but not both.
641 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
642 (mtd->_read && mtd->_read_oob)))
645 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
646 !(mtd->flags & MTD_NO_ERASE)))
650 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
651 * master is an MLC NAND and has a proper pairing scheme defined.
652 * We also reject masters that implement ->_writev() for now, because
653 * NAND controller drivers don't implement this hook, and adding the
654 * SLC -> MLC address/length conversion to this path is useless if we
657 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
658 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
659 !master->pairing || master->_writev))
662 mutex_lock(&mtd_table_mutex);
666 ofidx = of_alias_get_id(np, "mtd");
668 i = idr_alloc(&mtd_idr, mtd, ofidx, ofidx + 1, GFP_KERNEL);
670 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
679 /* default value if not set by driver */
680 if (mtd->bitflip_threshold == 0)
681 mtd->bitflip_threshold = mtd->ecc_strength;
683 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
684 int ngroups = mtd_pairing_groups(master);
686 mtd->erasesize /= ngroups;
687 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
691 if (is_power_of_2(mtd->erasesize))
692 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
694 mtd->erasesize_shift = 0;
696 if (is_power_of_2(mtd->writesize))
697 mtd->writesize_shift = ffs(mtd->writesize) - 1;
699 mtd->writesize_shift = 0;
701 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
702 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
704 /* Some chips always power up locked. Unlock them now */
705 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
706 error = mtd_unlock(mtd, 0, mtd->size);
707 if (error && error != -EOPNOTSUPP)
709 "%s: unlock failed, writes may not work\n",
711 /* Ignore unlock failures? */
715 /* Caller should have set dev.parent to match the
716 * physical device, if appropriate.
718 mtd->dev.type = &mtd_devtype;
719 mtd->dev.class = &mtd_class;
720 mtd->dev.devt = MTD_DEVT(i);
721 dev_set_name(&mtd->dev, "mtd%d", i);
722 dev_set_drvdata(&mtd->dev, mtd);
723 mtd_check_of_node(mtd);
724 of_node_get(mtd_get_of_node(mtd));
725 error = device_register(&mtd->dev);
727 put_device(&mtd->dev);
731 /* Add the nvmem provider */
732 error = mtd_nvmem_add(mtd);
736 mtd_debugfs_populate(mtd);
738 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
741 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
742 /* No need to get a refcount on the module containing
743 the notifier, since we hold the mtd_table_mutex */
744 list_for_each_entry(not, &mtd_notifiers, list)
747 mutex_unlock(&mtd_table_mutex);
748 /* We _know_ we aren't being removed, because
749 our caller is still holding us here. So none
750 of this try_ nonsense, and no bitching about it
752 __module_get(THIS_MODULE);
756 device_unregister(&mtd->dev);
758 of_node_put(mtd_get_of_node(mtd));
759 idr_remove(&mtd_idr, i);
761 mutex_unlock(&mtd_table_mutex);
766 * del_mtd_device - unregister an MTD device
767 * @mtd: pointer to MTD device info structure
769 * Remove a device from the list of MTD devices present in the system,
770 * and notify each currently active MTD 'user' of its departure.
771 * Returns zero on success or 1 on failure, which currently will happen
772 * if the requested device does not appear to be present in the list.
775 int del_mtd_device(struct mtd_info *mtd)
778 struct mtd_notifier *not;
779 struct device_node *mtd_of_node;
781 mutex_lock(&mtd_table_mutex);
783 if (idr_find(&mtd_idr, mtd->index) != mtd) {
788 /* No need to get a refcount on the module containing
789 the notifier, since we hold the mtd_table_mutex */
790 list_for_each_entry(not, &mtd_notifiers, list)
794 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
795 mtd->index, mtd->name, mtd->usecount);
798 mtd_of_node = mtd_get_of_node(mtd);
799 debugfs_remove_recursive(mtd->dbg.dfs_dir);
801 /* Try to remove the NVMEM provider */
802 nvmem_unregister(mtd->nvmem);
804 device_unregister(&mtd->dev);
806 /* Clear dev so mtd can be safely re-registered later if desired */
807 memset(&mtd->dev, 0, sizeof(mtd->dev));
809 idr_remove(&mtd_idr, mtd->index);
810 of_node_put(mtd_of_node);
812 module_put(THIS_MODULE);
817 mutex_unlock(&mtd_table_mutex);
822 * Set a few defaults based on the parent devices, if not provided by the
825 static void mtd_set_dev_defaults(struct mtd_info *mtd)
827 if (mtd->dev.parent) {
828 if (!mtd->owner && mtd->dev.parent->driver)
829 mtd->owner = mtd->dev.parent->driver->owner;
831 mtd->name = dev_name(mtd->dev.parent);
833 pr_debug("mtd device won't show a device symlink in sysfs\n");
836 INIT_LIST_HEAD(&mtd->partitions);
837 mutex_init(&mtd->master.partitions_lock);
838 mutex_init(&mtd->master.chrdev_lock);
841 static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
843 struct otp_info *info;
849 info = kmalloc(PAGE_SIZE, GFP_KERNEL);
854 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info);
856 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info);
860 for (i = 0; i < retlen / sizeof(*info); i++)
861 size += info[i].length;
869 /* ENODATA means there is no OTP region. */
870 return ret == -ENODATA ? 0 : ret;
873 static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
874 const char *compatible,
876 nvmem_reg_read_t reg_read)
878 struct nvmem_device *nvmem = NULL;
879 struct nvmem_config config = {};
880 struct device_node *np;
882 /* DT binding is optional */
883 np = of_get_compatible_child(mtd->dev.of_node, compatible);
885 /* OTP nvmem will be registered on the physical device */
886 config.dev = mtd->dev.parent;
887 config.name = compatible;
888 config.id = NVMEM_DEVID_AUTO;
889 config.owner = THIS_MODULE;
890 config.type = NVMEM_TYPE_OTP;
891 config.root_only = true;
892 config.ignore_wp = true;
893 config.reg_read = reg_read;
898 nvmem = nvmem_register(&config);
899 /* Just ignore if there is no NVMEM support in the kernel */
900 if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP)
908 static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
909 void *val, size_t bytes)
911 struct mtd_info *mtd = priv;
915 ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val);
919 return retlen == bytes ? 0 : -EIO;
922 static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
923 void *val, size_t bytes)
925 struct mtd_info *mtd = priv;
929 ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val);
933 return retlen == bytes ? 0 : -EIO;
936 static int mtd_otp_nvmem_add(struct mtd_info *mtd)
938 struct nvmem_device *nvmem;
942 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
943 size = mtd_otp_size(mtd, true);
948 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
949 mtd_nvmem_user_otp_reg_read);
951 dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
952 return PTR_ERR(nvmem);
954 mtd->otp_user_nvmem = nvmem;
958 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
959 size = mtd_otp_size(mtd, false);
966 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
967 mtd_nvmem_fact_otp_reg_read);
969 dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
970 err = PTR_ERR(nvmem);
973 mtd->otp_factory_nvmem = nvmem;
980 nvmem_unregister(mtd->otp_user_nvmem);
985 * mtd_device_parse_register - parse partitions and register an MTD device.
987 * @mtd: the MTD device to register
988 * @types: the list of MTD partition probes to try, see
989 * 'parse_mtd_partitions()' for more information
990 * @parser_data: MTD partition parser-specific data
991 * @parts: fallback partition information to register, if parsing fails;
992 * only valid if %nr_parts > %0
993 * @nr_parts: the number of partitions in parts, if zero then the full
994 * MTD device is registered if no partition info is found
996 * This function aggregates MTD partitions parsing (done by
997 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
998 * basically follows the most common pattern found in many MTD drivers:
1000 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
1002 * * Then It tries to probe partitions on MTD device @mtd using parsers
1003 * specified in @types (if @types is %NULL, then the default list of parsers
1004 * is used, see 'parse_mtd_partitions()' for more information). If none are
1005 * found this functions tries to fallback to information specified in
1007 * * If no partitions were found this function just registers the MTD device
1010 * Returns zero in case of success and a negative error code in case of failure.
1012 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
1013 struct mtd_part_parser_data *parser_data,
1014 const struct mtd_partition *parts,
1019 mtd_set_dev_defaults(mtd);
1021 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
1022 ret = add_mtd_device(mtd);
1027 /* Prefer parsed partitions over driver-provided fallback */
1028 ret = parse_mtd_partitions(mtd, types, parser_data);
1029 if (ret == -EPROBE_DEFER)
1035 ret = add_mtd_partitions(mtd, parts, nr_parts);
1036 else if (!device_is_registered(&mtd->dev))
1037 ret = add_mtd_device(mtd);
1045 * FIXME: some drivers unfortunately call this function more than once.
1046 * So we have to check if we've already assigned the reboot notifier.
1048 * Generally, we can make multiple calls work for most cases, but it
1049 * does cause problems with parse_mtd_partitions() above (e.g.,
1050 * cmdlineparts will register partitions more than once).
1052 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
1053 "MTD already registered\n");
1054 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
1055 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
1056 register_reboot_notifier(&mtd->reboot_notifier);
1059 ret = mtd_otp_nvmem_add(mtd);
1062 if (ret && device_is_registered(&mtd->dev))
1063 del_mtd_device(mtd);
1067 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
1070 * mtd_device_unregister - unregister an existing MTD device.
1072 * @master: the MTD device to unregister. This will unregister both the master
1073 * and any partitions if registered.
1075 int mtd_device_unregister(struct mtd_info *master)
1079 if (master->_reboot) {
1080 unregister_reboot_notifier(&master->reboot_notifier);
1081 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
1084 nvmem_unregister(master->otp_user_nvmem);
1085 nvmem_unregister(master->otp_factory_nvmem);
1087 err = del_mtd_partitions(master);
1091 if (!device_is_registered(&master->dev))
1094 return del_mtd_device(master);
1096 EXPORT_SYMBOL_GPL(mtd_device_unregister);
1099 * register_mtd_user - register a 'user' of MTD devices.
1100 * @new: pointer to notifier info structure
1102 * Registers a pair of callbacks function to be called upon addition
1103 * or removal of MTD devices. Causes the 'add' callback to be immediately
1104 * invoked for each MTD device currently present in the system.
1106 void register_mtd_user (struct mtd_notifier *new)
1108 struct mtd_info *mtd;
1110 mutex_lock(&mtd_table_mutex);
1112 list_add(&new->list, &mtd_notifiers);
1114 __module_get(THIS_MODULE);
1116 mtd_for_each_device(mtd)
1119 mutex_unlock(&mtd_table_mutex);
1121 EXPORT_SYMBOL_GPL(register_mtd_user);
1124 * unregister_mtd_user - unregister a 'user' of MTD devices.
1125 * @old: pointer to notifier info structure
1127 * Removes a callback function pair from the list of 'users' to be
1128 * notified upon addition or removal of MTD devices. Causes the
1129 * 'remove' callback to be immediately invoked for each MTD device
1130 * currently present in the system.
1132 int unregister_mtd_user (struct mtd_notifier *old)
1134 struct mtd_info *mtd;
1136 mutex_lock(&mtd_table_mutex);
1138 module_put(THIS_MODULE);
1140 mtd_for_each_device(mtd)
1143 list_del(&old->list);
1144 mutex_unlock(&mtd_table_mutex);
1147 EXPORT_SYMBOL_GPL(unregister_mtd_user);
1150 * get_mtd_device - obtain a validated handle for an MTD device
1151 * @mtd: last known address of the required MTD device
1152 * @num: internal device number of the required MTD device
1154 * Given a number and NULL address, return the num'th entry in the device
1155 * table, if any. Given an address and num == -1, search the device table
1156 * for a device with that address and return if it's still present. Given
1157 * both, return the num'th driver only if its address matches. Return
1158 * error code if not.
1160 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
1162 struct mtd_info *ret = NULL, *other;
1165 mutex_lock(&mtd_table_mutex);
1168 mtd_for_each_device(other) {
1174 } else if (num >= 0) {
1175 ret = idr_find(&mtd_idr, num);
1176 if (mtd && mtd != ret)
1185 err = __get_mtd_device(ret);
1189 mutex_unlock(&mtd_table_mutex);
1192 EXPORT_SYMBOL_GPL(get_mtd_device);
1195 int __get_mtd_device(struct mtd_info *mtd)
1197 struct mtd_info *master = mtd_get_master(mtd);
1200 if (!try_module_get(master->owner))
1203 if (master->_get_device) {
1204 err = master->_get_device(mtd);
1207 module_put(master->owner);
1214 while (mtd->parent) {
1221 EXPORT_SYMBOL_GPL(__get_mtd_device);
1224 * of_get_mtd_device_by_node - obtain an MTD device associated with a given node
1226 * @np: device tree node
1228 struct mtd_info *of_get_mtd_device_by_node(struct device_node *np)
1230 struct mtd_info *mtd = NULL;
1231 struct mtd_info *tmp;
1234 mutex_lock(&mtd_table_mutex);
1236 err = -EPROBE_DEFER;
1237 mtd_for_each_device(tmp) {
1238 if (mtd_get_of_node(tmp) == np) {
1240 err = __get_mtd_device(mtd);
1245 mutex_unlock(&mtd_table_mutex);
1247 return err ? ERR_PTR(err) : mtd;
1249 EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node);
1252 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1254 * @name: MTD device name to open
1256 * This function returns MTD device description structure in case of
1257 * success and an error code in case of failure.
1259 struct mtd_info *get_mtd_device_nm(const char *name)
1262 struct mtd_info *mtd = NULL, *other;
1264 mutex_lock(&mtd_table_mutex);
1266 mtd_for_each_device(other) {
1267 if (!strcmp(name, other->name)) {
1276 err = __get_mtd_device(mtd);
1280 mutex_unlock(&mtd_table_mutex);
1284 mutex_unlock(&mtd_table_mutex);
1285 return ERR_PTR(err);
1287 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1289 void put_mtd_device(struct mtd_info *mtd)
1291 mutex_lock(&mtd_table_mutex);
1292 __put_mtd_device(mtd);
1293 mutex_unlock(&mtd_table_mutex);
1296 EXPORT_SYMBOL_GPL(put_mtd_device);
1298 void __put_mtd_device(struct mtd_info *mtd)
1300 struct mtd_info *master = mtd_get_master(mtd);
1302 while (mtd->parent) {
1304 BUG_ON(mtd->usecount < 0);
1310 if (master->_put_device)
1311 master->_put_device(master);
1313 module_put(master->owner);
1315 EXPORT_SYMBOL_GPL(__put_mtd_device);
1318 * Erase is an synchronous operation. Device drivers are epected to return a
1319 * negative error code if the operation failed and update instr->fail_addr
1320 * to point the portion that was not properly erased.
1322 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1324 struct mtd_info *master = mtd_get_master(mtd);
1325 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1326 struct erase_info adjinstr;
1329 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1332 if (!mtd->erasesize || !master->_erase)
1335 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1337 if (!(mtd->flags & MTD_WRITEABLE))
1343 ledtrig_mtd_activity();
1345 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1346 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1348 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1349 master->erasesize) -
1353 adjinstr.addr += mst_ofs;
1355 ret = master->_erase(master, &adjinstr);
1357 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1358 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1359 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1360 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1362 instr->fail_addr *= mtd->erasesize;
1368 EXPORT_SYMBOL_GPL(mtd_erase);
1371 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1373 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1374 void **virt, resource_size_t *phys)
1376 struct mtd_info *master = mtd_get_master(mtd);
1382 if (!master->_point)
1384 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1389 from = mtd_get_master_ofs(mtd, from);
1390 return master->_point(master, from, len, retlen, virt, phys);
1392 EXPORT_SYMBOL_GPL(mtd_point);
1394 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1395 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1397 struct mtd_info *master = mtd_get_master(mtd);
1399 if (!master->_unpoint)
1401 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1405 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1407 EXPORT_SYMBOL_GPL(mtd_unpoint);
1410 * Allow NOMMU mmap() to directly map the device (if not NULL)
1411 * - return the address to which the offset maps
1412 * - return -ENOSYS to indicate refusal to do the mapping
1414 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1415 unsigned long offset, unsigned long flags)
1421 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1424 if (retlen != len) {
1425 mtd_unpoint(mtd, offset, retlen);
1428 return (unsigned long)virt;
1430 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1432 static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1433 const struct mtd_ecc_stats *old_stats)
1435 struct mtd_ecc_stats diff;
1440 diff = master->ecc_stats;
1441 diff.failed -= old_stats->failed;
1442 diff.corrected -= old_stats->corrected;
1444 while (mtd->parent) {
1445 mtd->ecc_stats.failed += diff.failed;
1446 mtd->ecc_stats.corrected += diff.corrected;
1451 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1454 struct mtd_oob_ops ops = {
1460 ret = mtd_read_oob(mtd, from, &ops);
1461 *retlen = ops.retlen;
1465 EXPORT_SYMBOL_GPL(mtd_read);
1467 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1470 struct mtd_oob_ops ops = {
1472 .datbuf = (u8 *)buf,
1476 ret = mtd_write_oob(mtd, to, &ops);
1477 *retlen = ops.retlen;
1481 EXPORT_SYMBOL_GPL(mtd_write);
1484 * In blackbox flight recorder like scenarios we want to make successful writes
1485 * in interrupt context. panic_write() is only intended to be called when its
1486 * known the kernel is about to panic and we need the write to succeed. Since
1487 * the kernel is not going to be running for much longer, this function can
1488 * break locks and delay to ensure the write succeeds (but not sleep).
1490 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1493 struct mtd_info *master = mtd_get_master(mtd);
1496 if (!master->_panic_write)
1498 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1500 if (!(mtd->flags & MTD_WRITEABLE))
1504 if (!master->oops_panic_write)
1505 master->oops_panic_write = true;
1507 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1510 EXPORT_SYMBOL_GPL(mtd_panic_write);
1512 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1513 struct mtd_oob_ops *ops)
1516 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1517 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1526 if (offs < 0 || offs + ops->len > mtd->size)
1532 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1535 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1536 mtd_div_by_ws(offs, mtd)) *
1537 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1538 if (ops->ooblen > maxooblen)
1545 static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1546 struct mtd_oob_ops *ops)
1548 struct mtd_info *master = mtd_get_master(mtd);
1551 from = mtd_get_master_ofs(mtd, from);
1552 if (master->_read_oob)
1553 ret = master->_read_oob(master, from, ops);
1555 ret = master->_read(master, from, ops->len, &ops->retlen,
1561 static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1562 struct mtd_oob_ops *ops)
1564 struct mtd_info *master = mtd_get_master(mtd);
1567 to = mtd_get_master_ofs(mtd, to);
1568 if (master->_write_oob)
1569 ret = master->_write_oob(master, to, ops);
1571 ret = master->_write(master, to, ops->len, &ops->retlen,
1577 static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1578 struct mtd_oob_ops *ops)
1580 struct mtd_info *master = mtd_get_master(mtd);
1581 int ngroups = mtd_pairing_groups(master);
1582 int npairs = mtd_wunit_per_eb(master) / ngroups;
1583 struct mtd_oob_ops adjops = *ops;
1584 unsigned int wunit, oobavail;
1585 struct mtd_pairing_info info;
1586 int max_bitflips = 0;
1590 ebofs = mtd_mod_by_eb(start, mtd);
1591 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1593 info.pair = mtd_div_by_ws(ebofs, mtd);
1594 pageofs = mtd_mod_by_ws(ebofs, mtd);
1595 oobavail = mtd_oobavail(mtd, ops);
1597 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1600 if (info.pair >= npairs) {
1602 base += master->erasesize;
1605 wunit = mtd_pairing_info_to_wunit(master, &info);
1606 pos = mtd_wunit_to_offset(mtd, base, wunit);
1608 adjops.len = ops->len - ops->retlen;
1609 if (adjops.len > mtd->writesize - pageofs)
1610 adjops.len = mtd->writesize - pageofs;
1612 adjops.ooblen = ops->ooblen - ops->oobretlen;
1613 if (adjops.ooblen > oobavail - adjops.ooboffs)
1614 adjops.ooblen = oobavail - adjops.ooboffs;
1617 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1619 max_bitflips = max(max_bitflips, ret);
1621 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1627 max_bitflips = max(max_bitflips, ret);
1628 ops->retlen += adjops.retlen;
1629 ops->oobretlen += adjops.oobretlen;
1630 adjops.datbuf += adjops.retlen;
1631 adjops.oobbuf += adjops.oobretlen;
1637 return max_bitflips;
1640 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1642 struct mtd_info *master = mtd_get_master(mtd);
1643 struct mtd_ecc_stats old_stats = master->ecc_stats;
1646 ops->retlen = ops->oobretlen = 0;
1648 ret_code = mtd_check_oob_ops(mtd, from, ops);
1652 ledtrig_mtd_activity();
1654 /* Check the validity of a potential fallback on mtd->_read */
1655 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1659 memset(ops->stats, 0, sizeof(*ops->stats));
1661 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1662 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1664 ret_code = mtd_read_oob_std(mtd, from, ops);
1666 mtd_update_ecc_stats(mtd, master, &old_stats);
1669 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1670 * similar to mtd->_read(), returning a non-negative integer
1671 * representing max bitflips. In other cases, mtd->_read_oob() may
1672 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1674 if (unlikely(ret_code < 0))
1676 if (mtd->ecc_strength == 0)
1677 return 0; /* device lacks ecc */
1679 ops->stats->max_bitflips = ret_code;
1680 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1682 EXPORT_SYMBOL_GPL(mtd_read_oob);
1684 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1685 struct mtd_oob_ops *ops)
1687 struct mtd_info *master = mtd_get_master(mtd);
1690 ops->retlen = ops->oobretlen = 0;
1692 if (!(mtd->flags & MTD_WRITEABLE))
1695 ret = mtd_check_oob_ops(mtd, to, ops);
1699 ledtrig_mtd_activity();
1701 /* Check the validity of a potential fallback on mtd->_write */
1702 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1705 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1706 return mtd_io_emulated_slc(mtd, to, false, ops);
1708 return mtd_write_oob_std(mtd, to, ops);
1710 EXPORT_SYMBOL_GPL(mtd_write_oob);
1713 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1714 * @mtd: MTD device structure
1715 * @section: ECC section. Depending on the layout you may have all the ECC
1716 * bytes stored in a single contiguous section, or one section
1717 * per ECC chunk (and sometime several sections for a single ECC
1719 * @oobecc: OOB region struct filled with the appropriate ECC position
1722 * This function returns ECC section information in the OOB area. If you want
1723 * to get all the ECC bytes information, then you should call
1724 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1726 * Returns zero on success, a negative error code otherwise.
1728 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1729 struct mtd_oob_region *oobecc)
1731 struct mtd_info *master = mtd_get_master(mtd);
1733 memset(oobecc, 0, sizeof(*oobecc));
1735 if (!master || section < 0)
1738 if (!master->ooblayout || !master->ooblayout->ecc)
1741 return master->ooblayout->ecc(master, section, oobecc);
1743 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1746 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1748 * @mtd: MTD device structure
1749 * @section: Free section you are interested in. Depending on the layout
1750 * you may have all the free bytes stored in a single contiguous
1751 * section, or one section per ECC chunk plus an extra section
1752 * for the remaining bytes (or other funky layout).
1753 * @oobfree: OOB region struct filled with the appropriate free position
1756 * This function returns free bytes position in the OOB area. If you want
1757 * to get all the free bytes information, then you should call
1758 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1760 * Returns zero on success, a negative error code otherwise.
1762 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1763 struct mtd_oob_region *oobfree)
1765 struct mtd_info *master = mtd_get_master(mtd);
1767 memset(oobfree, 0, sizeof(*oobfree));
1769 if (!master || section < 0)
1772 if (!master->ooblayout || !master->ooblayout->free)
1775 return master->ooblayout->free(master, section, oobfree);
1777 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1780 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1781 * @mtd: mtd info structure
1782 * @byte: the byte we are searching for
1783 * @sectionp: pointer where the section id will be stored
1784 * @oobregion: used to retrieve the ECC position
1785 * @iter: iterator function. Should be either mtd_ooblayout_free or
1786 * mtd_ooblayout_ecc depending on the region type you're searching for
1788 * This function returns the section id and oobregion information of a
1789 * specific byte. For example, say you want to know where the 4th ECC byte is
1790 * stored, you'll use:
1792 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1794 * Returns zero on success, a negative error code otherwise.
1796 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1797 int *sectionp, struct mtd_oob_region *oobregion,
1798 int (*iter)(struct mtd_info *,
1800 struct mtd_oob_region *oobregion))
1802 int pos = 0, ret, section = 0;
1804 memset(oobregion, 0, sizeof(*oobregion));
1807 ret = iter(mtd, section, oobregion);
1811 if (pos + oobregion->length > byte)
1814 pos += oobregion->length;
1819 * Adjust region info to make it start at the beginning at the
1822 oobregion->offset += byte - pos;
1823 oobregion->length -= byte - pos;
1824 *sectionp = section;
1830 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1832 * @mtd: mtd info structure
1833 * @eccbyte: the byte we are searching for
1834 * @section: pointer where the section id will be stored
1835 * @oobregion: OOB region information
1837 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1840 * Returns zero on success, a negative error code otherwise.
1842 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1844 struct mtd_oob_region *oobregion)
1846 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1849 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1852 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1853 * @mtd: mtd info structure
1854 * @buf: destination buffer to store OOB bytes
1855 * @oobbuf: OOB buffer
1856 * @start: first byte to retrieve
1857 * @nbytes: number of bytes to retrieve
1858 * @iter: section iterator
1860 * Extract bytes attached to a specific category (ECC or free)
1861 * from the OOB buffer and copy them into buf.
1863 * Returns zero on success, a negative error code otherwise.
1865 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1866 const u8 *oobbuf, int start, int nbytes,
1867 int (*iter)(struct mtd_info *,
1869 struct mtd_oob_region *oobregion))
1871 struct mtd_oob_region oobregion;
1874 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1880 cnt = min_t(int, nbytes, oobregion.length);
1881 memcpy(buf, oobbuf + oobregion.offset, cnt);
1888 ret = iter(mtd, ++section, &oobregion);
1895 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1896 * @mtd: mtd info structure
1897 * @buf: source buffer to get OOB bytes from
1898 * @oobbuf: OOB buffer
1899 * @start: first OOB byte to set
1900 * @nbytes: number of OOB bytes to set
1901 * @iter: section iterator
1903 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1904 * is selected by passing the appropriate iterator.
1906 * Returns zero on success, a negative error code otherwise.
1908 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1909 u8 *oobbuf, int start, int nbytes,
1910 int (*iter)(struct mtd_info *,
1912 struct mtd_oob_region *oobregion))
1914 struct mtd_oob_region oobregion;
1917 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1923 cnt = min_t(int, nbytes, oobregion.length);
1924 memcpy(oobbuf + oobregion.offset, buf, cnt);
1931 ret = iter(mtd, ++section, &oobregion);
1938 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1939 * @mtd: mtd info structure
1940 * @iter: category iterator
1942 * Count the number of bytes in a given category.
1944 * Returns a positive value on success, a negative error code otherwise.
1946 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1947 int (*iter)(struct mtd_info *,
1949 struct mtd_oob_region *oobregion))
1951 struct mtd_oob_region oobregion;
1952 int section = 0, ret, nbytes = 0;
1955 ret = iter(mtd, section++, &oobregion);
1962 nbytes += oobregion.length;
1969 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1970 * @mtd: mtd info structure
1971 * @eccbuf: destination buffer to store ECC bytes
1972 * @oobbuf: OOB buffer
1973 * @start: first ECC byte to retrieve
1974 * @nbytes: number of ECC bytes to retrieve
1976 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1978 * Returns zero on success, a negative error code otherwise.
1980 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1981 const u8 *oobbuf, int start, int nbytes)
1983 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1986 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1989 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1990 * @mtd: mtd info structure
1991 * @eccbuf: source buffer to get ECC bytes from
1992 * @oobbuf: OOB buffer
1993 * @start: first ECC byte to set
1994 * @nbytes: number of ECC bytes to set
1996 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1998 * Returns zero on success, a negative error code otherwise.
2000 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
2001 u8 *oobbuf, int start, int nbytes)
2003 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
2006 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
2009 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
2010 * @mtd: mtd info structure
2011 * @databuf: destination buffer to store ECC bytes
2012 * @oobbuf: OOB buffer
2013 * @start: first ECC byte to retrieve
2014 * @nbytes: number of ECC bytes to retrieve
2016 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
2018 * Returns zero on success, a negative error code otherwise.
2020 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
2021 const u8 *oobbuf, int start, int nbytes)
2023 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
2024 mtd_ooblayout_free);
2026 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
2029 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
2030 * @mtd: mtd info structure
2031 * @databuf: source buffer to get data bytes from
2032 * @oobbuf: OOB buffer
2033 * @start: first ECC byte to set
2034 * @nbytes: number of ECC bytes to set
2036 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
2038 * Returns zero on success, a negative error code otherwise.
2040 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
2041 u8 *oobbuf, int start, int nbytes)
2043 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
2044 mtd_ooblayout_free);
2046 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
2049 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
2050 * @mtd: mtd info structure
2052 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
2054 * Returns zero on success, a negative error code otherwise.
2056 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
2058 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
2060 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
2063 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
2064 * @mtd: mtd info structure
2066 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
2068 * Returns zero on success, a negative error code otherwise.
2070 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
2072 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
2074 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
2077 * Method to access the protection register area, present in some flash
2078 * devices. The user data is one time programmable but the factory data is read
2081 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2082 struct otp_info *buf)
2084 struct mtd_info *master = mtd_get_master(mtd);
2086 if (!master->_get_fact_prot_info)
2090 return master->_get_fact_prot_info(master, len, retlen, buf);
2092 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
2094 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2095 size_t *retlen, u_char *buf)
2097 struct mtd_info *master = mtd_get_master(mtd);
2100 if (!master->_read_fact_prot_reg)
2104 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
2106 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
2108 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2109 struct otp_info *buf)
2111 struct mtd_info *master = mtd_get_master(mtd);
2113 if (!master->_get_user_prot_info)
2117 return master->_get_user_prot_info(master, len, retlen, buf);
2119 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
2121 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2122 size_t *retlen, u_char *buf)
2124 struct mtd_info *master = mtd_get_master(mtd);
2127 if (!master->_read_user_prot_reg)
2131 return master->_read_user_prot_reg(master, from, len, retlen, buf);
2133 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
2135 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
2136 size_t *retlen, const u_char *buf)
2138 struct mtd_info *master = mtd_get_master(mtd);
2142 if (!master->_write_user_prot_reg)
2146 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
2151 * If no data could be written at all, we are out of memory and
2152 * must return -ENOSPC.
2154 return (*retlen) ? 0 : -ENOSPC;
2156 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
2158 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2160 struct mtd_info *master = mtd_get_master(mtd);
2162 if (!master->_lock_user_prot_reg)
2166 return master->_lock_user_prot_reg(master, from, len);
2168 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
2170 int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2172 struct mtd_info *master = mtd_get_master(mtd);
2174 if (!master->_erase_user_prot_reg)
2178 return master->_erase_user_prot_reg(master, from, len);
2180 EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
2182 /* Chip-supported device locking */
2183 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2185 struct mtd_info *master = mtd_get_master(mtd);
2189 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2194 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2195 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2196 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2199 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
2201 EXPORT_SYMBOL_GPL(mtd_lock);
2203 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2205 struct mtd_info *master = mtd_get_master(mtd);
2207 if (!master->_unlock)
2209 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2214 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2215 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2216 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2219 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
2221 EXPORT_SYMBOL_GPL(mtd_unlock);
2223 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2225 struct mtd_info *master = mtd_get_master(mtd);
2227 if (!master->_is_locked)
2229 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2234 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2235 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2236 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2239 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
2241 EXPORT_SYMBOL_GPL(mtd_is_locked);
2243 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2245 struct mtd_info *master = mtd_get_master(mtd);
2247 if (ofs < 0 || ofs >= mtd->size)
2249 if (!master->_block_isreserved)
2252 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2253 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2255 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2257 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2259 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2261 struct mtd_info *master = mtd_get_master(mtd);
2263 if (ofs < 0 || ofs >= mtd->size)
2265 if (!master->_block_isbad)
2268 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2269 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2271 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2273 EXPORT_SYMBOL_GPL(mtd_block_isbad);
2275 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2277 struct mtd_info *master = mtd_get_master(mtd);
2280 if (!master->_block_markbad)
2282 if (ofs < 0 || ofs >= mtd->size)
2284 if (!(mtd->flags & MTD_WRITEABLE))
2287 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2288 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2290 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2294 while (mtd->parent) {
2295 mtd->ecc_stats.badblocks++;
2301 EXPORT_SYMBOL_GPL(mtd_block_markbad);
2304 * default_mtd_writev - the default writev method
2305 * @mtd: mtd device description object pointer
2306 * @vecs: the vectors to write
2307 * @count: count of vectors in @vecs
2308 * @to: the MTD device offset to write to
2309 * @retlen: on exit contains the count of bytes written to the MTD device.
2311 * This function returns zero in case of success and a negative error code in
2314 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2315 unsigned long count, loff_t to, size_t *retlen)
2318 size_t totlen = 0, thislen;
2321 for (i = 0; i < count; i++) {
2322 if (!vecs[i].iov_len)
2324 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2327 if (ret || thislen != vecs[i].iov_len)
2329 to += vecs[i].iov_len;
2336 * mtd_writev - the vector-based MTD write method
2337 * @mtd: mtd device description object pointer
2338 * @vecs: the vectors to write
2339 * @count: count of vectors in @vecs
2340 * @to: the MTD device offset to write to
2341 * @retlen: on exit contains the count of bytes written to the MTD device.
2343 * This function returns zero in case of success and a negative error code in
2346 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2347 unsigned long count, loff_t to, size_t *retlen)
2349 struct mtd_info *master = mtd_get_master(mtd);
2352 if (!(mtd->flags & MTD_WRITEABLE))
2355 if (!master->_writev)
2356 return default_mtd_writev(mtd, vecs, count, to, retlen);
2358 return master->_writev(master, vecs, count,
2359 mtd_get_master_ofs(mtd, to), retlen);
2361 EXPORT_SYMBOL_GPL(mtd_writev);
2364 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2365 * @mtd: mtd device description object pointer
2366 * @size: a pointer to the ideal or maximum size of the allocation, points
2367 * to the actual allocation size on success.
2369 * This routine attempts to allocate a contiguous kernel buffer up to
2370 * the specified size, backing off the size of the request exponentially
2371 * until the request succeeds or until the allocation size falls below
2372 * the system page size. This attempts to make sure it does not adversely
2373 * impact system performance, so when allocating more than one page, we
2374 * ask the memory allocator to avoid re-trying, swapping, writing back
2375 * or performing I/O.
2377 * Note, this function also makes sure that the allocated buffer is aligned to
2378 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2380 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2381 * to handle smaller (i.e. degraded) buffer allocations under low- or
2382 * fragmented-memory situations where such reduced allocations, from a
2383 * requested ideal, are allowed.
2385 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2387 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2389 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2390 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2393 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2395 while (*size > min_alloc) {
2396 kbuf = kmalloc(*size, flags);
2401 *size = ALIGN(*size, mtd->writesize);
2405 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2406 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2408 return kmalloc(*size, GFP_KERNEL);
2410 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2412 #ifdef CONFIG_PROC_FS
2414 /*====================================================================*/
2415 /* Support for /proc/mtd */
2417 static int mtd_proc_show(struct seq_file *m, void *v)
2419 struct mtd_info *mtd;
2421 seq_puts(m, "dev: size erasesize name\n");
2422 mutex_lock(&mtd_table_mutex);
2423 mtd_for_each_device(mtd) {
2424 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2425 mtd->index, (unsigned long long)mtd->size,
2426 mtd->erasesize, mtd->name);
2428 mutex_unlock(&mtd_table_mutex);
2431 #endif /* CONFIG_PROC_FS */
2433 /*====================================================================*/
2436 static struct backing_dev_info * __init mtd_bdi_init(const char *name)
2438 struct backing_dev_info *bdi;
2441 bdi = bdi_alloc(NUMA_NO_NODE);
2443 return ERR_PTR(-ENOMEM);
2448 * We put '-0' suffix to the name to get the same name format as we
2449 * used to get. Since this is called only once, we get a unique name.
2451 ret = bdi_register(bdi, "%.28s-0", name);
2455 return ret ? ERR_PTR(ret) : bdi;
2458 static struct proc_dir_entry *proc_mtd;
2460 static int __init init_mtd(void)
2464 ret = class_register(&mtd_class);
2468 mtd_bdi = mtd_bdi_init("mtd");
2469 if (IS_ERR(mtd_bdi)) {
2470 ret = PTR_ERR(mtd_bdi);
2474 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2476 ret = init_mtdchar();
2480 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2481 debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd,
2482 &mtd_expert_analysis_mode);
2488 remove_proc_entry("mtd", NULL);
2489 bdi_unregister(mtd_bdi);
2492 class_unregister(&mtd_class);
2494 pr_err("Error registering mtd class or bdi: %d\n", ret);
2498 static void __exit cleanup_mtd(void)
2500 debugfs_remove_recursive(dfs_dir_mtd);
2503 remove_proc_entry("mtd", NULL);
2504 class_unregister(&mtd_class);
2505 bdi_unregister(mtd_bdi);
2507 idr_destroy(&mtd_idr);
2510 module_init(init_mtd);
2511 module_exit(cleanup_mtd);
2513 MODULE_LICENSE("GPL");
2514 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2515 MODULE_DESCRIPTION("Core MTD registration and access routines");