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/random.h>
27 #include <linux/slab.h>
28 #include <linux/reboot.h>
29 #include <linux/leds.h>
30 #include <linux/debugfs.h>
31 #include <linux/nvmem-provider.h>
32 #include <linux/root_dev.h>
34 #include <linux/mtd/mtd.h>
35 #include <linux/mtd/partitions.h>
39 struct backing_dev_info *mtd_bdi;
41 #ifdef CONFIG_PM_SLEEP
43 static int mtd_cls_suspend(struct device *dev)
45 struct mtd_info *mtd = dev_get_drvdata(dev);
47 return mtd ? mtd_suspend(mtd) : 0;
50 static int mtd_cls_resume(struct device *dev)
52 struct mtd_info *mtd = dev_get_drvdata(dev);
59 static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
60 #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
62 #define MTD_CLS_PM_OPS NULL
65 static struct class mtd_class = {
70 static DEFINE_IDR(mtd_idr);
72 /* These are exported solely for the purpose of mtd_blkdevs.c. You
73 should not use them for _anything_ else */
74 DEFINE_MUTEX(mtd_table_mutex);
75 EXPORT_SYMBOL_GPL(mtd_table_mutex);
77 struct mtd_info *__mtd_next_device(int i)
79 return idr_get_next(&mtd_idr, &i);
81 EXPORT_SYMBOL_GPL(__mtd_next_device);
83 static LIST_HEAD(mtd_notifiers);
86 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
88 /* REVISIT once MTD uses the driver model better, whoever allocates
89 * the mtd_info will probably want to use the release() hook...
91 static void mtd_release(struct device *dev)
93 struct mtd_info *mtd = dev_get_drvdata(dev);
94 dev_t index = MTD_DEVT(mtd->index);
96 idr_remove(&mtd_idr, mtd->index);
97 of_node_put(mtd_get_of_node(mtd));
99 if (mtd_is_partition(mtd))
100 release_mtd_partition(mtd);
102 /* remove /dev/mtdXro node */
103 device_destroy(&mtd_class, index + 1);
106 static void mtd_device_release(struct kref *kref)
108 struct mtd_info *mtd = container_of(kref, struct mtd_info, refcnt);
109 bool is_partition = mtd_is_partition(mtd);
111 debugfs_remove_recursive(mtd->dbg.dfs_dir);
113 /* Try to remove the NVMEM provider */
114 nvmem_unregister(mtd->nvmem);
116 device_unregister(&mtd->dev);
119 * Clear dev so mtd can be safely re-registered later if desired.
120 * Should not be done for partition,
121 * as it was already destroyed in device_unregister().
124 memset(&mtd->dev, 0, sizeof(mtd->dev));
126 module_put(THIS_MODULE);
129 #define MTD_DEVICE_ATTR_RO(name) \
130 static DEVICE_ATTR(name, 0444, mtd_##name##_show, NULL)
132 #define MTD_DEVICE_ATTR_RW(name) \
133 static DEVICE_ATTR(name, 0644, mtd_##name##_show, mtd_##name##_store)
135 static ssize_t mtd_type_show(struct device *dev,
136 struct device_attribute *attr, char *buf)
138 struct mtd_info *mtd = dev_get_drvdata(dev);
163 case MTD_MLCNANDFLASH:
170 return sysfs_emit(buf, "%s\n", type);
172 MTD_DEVICE_ATTR_RO(type);
174 static ssize_t mtd_flags_show(struct device *dev,
175 struct device_attribute *attr, char *buf)
177 struct mtd_info *mtd = dev_get_drvdata(dev);
179 return sysfs_emit(buf, "0x%lx\n", (unsigned long)mtd->flags);
181 MTD_DEVICE_ATTR_RO(flags);
183 static ssize_t mtd_size_show(struct device *dev,
184 struct device_attribute *attr, char *buf)
186 struct mtd_info *mtd = dev_get_drvdata(dev);
188 return sysfs_emit(buf, "%llu\n", (unsigned long long)mtd->size);
190 MTD_DEVICE_ATTR_RO(size);
192 static ssize_t mtd_erasesize_show(struct device *dev,
193 struct device_attribute *attr, char *buf)
195 struct mtd_info *mtd = dev_get_drvdata(dev);
197 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize);
199 MTD_DEVICE_ATTR_RO(erasesize);
201 static ssize_t mtd_writesize_show(struct device *dev,
202 struct device_attribute *attr, char *buf)
204 struct mtd_info *mtd = dev_get_drvdata(dev);
206 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->writesize);
208 MTD_DEVICE_ATTR_RO(writesize);
210 static ssize_t mtd_subpagesize_show(struct device *dev,
211 struct device_attribute *attr, char *buf)
213 struct mtd_info *mtd = dev_get_drvdata(dev);
214 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
216 return sysfs_emit(buf, "%u\n", subpagesize);
218 MTD_DEVICE_ATTR_RO(subpagesize);
220 static ssize_t mtd_oobsize_show(struct device *dev,
221 struct device_attribute *attr, char *buf)
223 struct mtd_info *mtd = dev_get_drvdata(dev);
225 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->oobsize);
227 MTD_DEVICE_ATTR_RO(oobsize);
229 static ssize_t mtd_oobavail_show(struct device *dev,
230 struct device_attribute *attr, char *buf)
232 struct mtd_info *mtd = dev_get_drvdata(dev);
234 return sysfs_emit(buf, "%u\n", mtd->oobavail);
236 MTD_DEVICE_ATTR_RO(oobavail);
238 static ssize_t mtd_numeraseregions_show(struct device *dev,
239 struct device_attribute *attr, char *buf)
241 struct mtd_info *mtd = dev_get_drvdata(dev);
243 return sysfs_emit(buf, "%u\n", mtd->numeraseregions);
245 MTD_DEVICE_ATTR_RO(numeraseregions);
247 static ssize_t mtd_name_show(struct device *dev,
248 struct device_attribute *attr, char *buf)
250 struct mtd_info *mtd = dev_get_drvdata(dev);
252 return sysfs_emit(buf, "%s\n", mtd->name);
254 MTD_DEVICE_ATTR_RO(name);
256 static ssize_t mtd_ecc_strength_show(struct device *dev,
257 struct device_attribute *attr, char *buf)
259 struct mtd_info *mtd = dev_get_drvdata(dev);
261 return sysfs_emit(buf, "%u\n", mtd->ecc_strength);
263 MTD_DEVICE_ATTR_RO(ecc_strength);
265 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
266 struct device_attribute *attr,
269 struct mtd_info *mtd = dev_get_drvdata(dev);
271 return sysfs_emit(buf, "%u\n", mtd->bitflip_threshold);
274 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
275 struct device_attribute *attr,
276 const char *buf, size_t count)
278 struct mtd_info *mtd = dev_get_drvdata(dev);
279 unsigned int bitflip_threshold;
282 retval = kstrtouint(buf, 0, &bitflip_threshold);
286 mtd->bitflip_threshold = bitflip_threshold;
289 MTD_DEVICE_ATTR_RW(bitflip_threshold);
291 static ssize_t mtd_ecc_step_size_show(struct device *dev,
292 struct device_attribute *attr, char *buf)
294 struct mtd_info *mtd = dev_get_drvdata(dev);
296 return sysfs_emit(buf, "%u\n", mtd->ecc_step_size);
299 MTD_DEVICE_ATTR_RO(ecc_step_size);
301 static ssize_t mtd_corrected_bits_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->corrected);
309 MTD_DEVICE_ATTR_RO(corrected_bits); /* ecc stats corrected */
311 static ssize_t mtd_ecc_failures_show(struct device *dev,
312 struct device_attribute *attr, char *buf)
314 struct mtd_info *mtd = dev_get_drvdata(dev);
315 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
317 return sysfs_emit(buf, "%u\n", ecc_stats->failed);
319 MTD_DEVICE_ATTR_RO(ecc_failures); /* ecc stats errors */
321 static ssize_t mtd_bad_blocks_show(struct device *dev,
322 struct device_attribute *attr, char *buf)
324 struct mtd_info *mtd = dev_get_drvdata(dev);
325 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
327 return sysfs_emit(buf, "%u\n", ecc_stats->badblocks);
329 MTD_DEVICE_ATTR_RO(bad_blocks);
331 static ssize_t mtd_bbt_blocks_show(struct device *dev,
332 struct device_attribute *attr, char *buf)
334 struct mtd_info *mtd = dev_get_drvdata(dev);
335 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
337 return sysfs_emit(buf, "%u\n", ecc_stats->bbtblocks);
339 MTD_DEVICE_ATTR_RO(bbt_blocks);
341 static struct attribute *mtd_attrs[] = {
343 &dev_attr_flags.attr,
345 &dev_attr_erasesize.attr,
346 &dev_attr_writesize.attr,
347 &dev_attr_subpagesize.attr,
348 &dev_attr_oobsize.attr,
349 &dev_attr_oobavail.attr,
350 &dev_attr_numeraseregions.attr,
352 &dev_attr_ecc_strength.attr,
353 &dev_attr_ecc_step_size.attr,
354 &dev_attr_corrected_bits.attr,
355 &dev_attr_ecc_failures.attr,
356 &dev_attr_bad_blocks.attr,
357 &dev_attr_bbt_blocks.attr,
358 &dev_attr_bitflip_threshold.attr,
361 ATTRIBUTE_GROUPS(mtd);
363 static const struct device_type mtd_devtype = {
365 .groups = mtd_groups,
366 .release = mtd_release,
369 static bool mtd_expert_analysis_mode;
371 #ifdef CONFIG_DEBUG_FS
372 bool mtd_check_expert_analysis_mode(void)
374 const char *mtd_expert_analysis_warning =
375 "Bad block checks have been entirely disabled.\n"
376 "This is only reserved for post-mortem forensics and debug purposes.\n"
377 "Never enable this mode if you do not know what you are doing!\n";
379 return WARN_ONCE(mtd_expert_analysis_mode, mtd_expert_analysis_warning);
381 EXPORT_SYMBOL_GPL(mtd_check_expert_analysis_mode);
384 static struct dentry *dfs_dir_mtd;
386 static void mtd_debugfs_populate(struct mtd_info *mtd)
388 struct device *dev = &mtd->dev;
390 if (IS_ERR_OR_NULL(dfs_dir_mtd))
393 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
397 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
401 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
402 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
404 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
407 return NOMMU_MAP_COPY;
410 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
413 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
416 struct mtd_info *mtd;
418 mtd = container_of(n, struct mtd_info, reboot_notifier);
425 * mtd_wunit_to_pairing_info - get pairing information of a wunit
426 * @mtd: pointer to new MTD device info structure
427 * @wunit: write unit we are interested in
428 * @info: returned pairing information
430 * Retrieve pairing information associated to the wunit.
431 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
432 * paired together, and where programming a page may influence the page it is
434 * The notion of page is replaced by the term wunit (write-unit) to stay
435 * consistent with the ->writesize field.
437 * The @wunit argument can be extracted from an absolute offset using
438 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
441 * From the pairing info the MTD user can find all the wunits paired with
442 * @wunit using the following loop:
444 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
446 * mtd_pairing_info_to_wunit(mtd, &info);
450 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
451 struct mtd_pairing_info *info)
453 struct mtd_info *master = mtd_get_master(mtd);
454 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
456 if (wunit < 0 || wunit >= npairs)
459 if (master->pairing && master->pairing->get_info)
460 return master->pairing->get_info(master, wunit, info);
467 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
470 * mtd_pairing_info_to_wunit - get wunit from pairing information
471 * @mtd: pointer to new MTD device info structure
472 * @info: pairing information struct
474 * Returns a positive number representing the wunit associated to the info
475 * struct, or a negative error code.
477 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
478 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
481 * It can also be used to only program the first page of each pair (i.e.
482 * page attached to group 0), which allows one to use an MLC NAND in
483 * software-emulated SLC mode:
486 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
487 * for (info.pair = 0; info.pair < npairs; info.pair++) {
488 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
489 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
490 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
493 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
494 const struct mtd_pairing_info *info)
496 struct mtd_info *master = mtd_get_master(mtd);
497 int ngroups = mtd_pairing_groups(master);
498 int npairs = mtd_wunit_per_eb(master) / ngroups;
500 if (!info || info->pair < 0 || info->pair >= npairs ||
501 info->group < 0 || info->group >= ngroups)
504 if (master->pairing && master->pairing->get_wunit)
505 return mtd->pairing->get_wunit(master, info);
509 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
512 * mtd_pairing_groups - get the number of pairing groups
513 * @mtd: pointer to new MTD device info structure
515 * Returns the number of pairing groups.
517 * This number is usually equal to the number of bits exposed by a single
518 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
519 * to iterate over all pages of a given pair.
521 int mtd_pairing_groups(struct mtd_info *mtd)
523 struct mtd_info *master = mtd_get_master(mtd);
525 if (!master->pairing || !master->pairing->ngroups)
528 return master->pairing->ngroups;
530 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
532 static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
533 void *val, size_t bytes)
535 struct mtd_info *mtd = priv;
539 err = mtd_read(mtd, offset, bytes, &retlen, val);
540 if (err && err != -EUCLEAN)
543 return retlen == bytes ? 0 : -EIO;
546 static int mtd_nvmem_add(struct mtd_info *mtd)
548 struct device_node *node = mtd_get_of_node(mtd);
549 struct nvmem_config config = {};
551 config.id = NVMEM_DEVID_NONE;
552 config.dev = &mtd->dev;
553 config.name = dev_name(&mtd->dev);
554 config.owner = THIS_MODULE;
555 config.add_legacy_fixed_of_cells = of_device_is_compatible(node, "nvmem-cells");
556 config.reg_read = mtd_nvmem_reg_read;
557 config.size = mtd->size;
558 config.word_size = 1;
560 config.read_only = true;
561 config.root_only = true;
562 config.ignore_wp = true;
565 mtd->nvmem = nvmem_register(&config);
566 if (IS_ERR(mtd->nvmem)) {
567 /* Just ignore if there is no NVMEM support in the kernel */
568 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP)
571 return dev_err_probe(&mtd->dev, PTR_ERR(mtd->nvmem),
572 "Failed to register NVMEM device\n");
578 static void mtd_check_of_node(struct mtd_info *mtd)
580 struct device_node *partitions, *parent_dn, *mtd_dn = NULL;
581 const char *pname, *prefix = "partition-";
582 int plen, mtd_name_len, offset, prefix_len;
584 /* Check if MTD already has a device node */
585 if (mtd_get_of_node(mtd))
588 if (!mtd_is_partition(mtd))
591 parent_dn = of_node_get(mtd_get_of_node(mtd->parent));
595 if (mtd_is_partition(mtd->parent))
596 partitions = of_node_get(parent_dn);
598 partitions = of_get_child_by_name(parent_dn, "partitions");
602 prefix_len = strlen(prefix);
603 mtd_name_len = strlen(mtd->name);
605 /* Search if a partition is defined with the same name */
606 for_each_child_of_node(partitions, mtd_dn) {
607 /* Skip partition with no/wrong prefix */
608 if (!of_node_name_prefix(mtd_dn, prefix))
611 /* Label have priority. Check that first */
612 if (!of_property_read_string(mtd_dn, "label", &pname)) {
615 pname = mtd_dn->name;
619 plen = strlen(pname) - offset;
620 if (plen == mtd_name_len &&
621 !strncmp(mtd->name, pname + offset, plen)) {
622 mtd_set_of_node(mtd, mtd_dn);
627 of_node_put(partitions);
629 of_node_put(parent_dn);
633 * add_mtd_device - register an MTD device
634 * @mtd: pointer to new MTD device info structure
636 * Add a device to the list of MTD devices present in the system, and
637 * notify each currently active MTD 'user' of its arrival. Returns
638 * zero on success or non-zero on failure.
641 int add_mtd_device(struct mtd_info *mtd)
643 struct device_node *np = mtd_get_of_node(mtd);
644 struct mtd_info *master = mtd_get_master(mtd);
645 struct mtd_notifier *not;
649 * May occur, for instance, on buggy drivers which call
650 * mtd_device_parse_register() multiple times on the same master MTD,
651 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
653 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
656 BUG_ON(mtd->writesize == 0);
659 * MTD drivers should implement ->_{write,read}() or
660 * ->_{write,read}_oob(), but not both.
662 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
663 (mtd->_read && mtd->_read_oob)))
666 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
667 !(mtd->flags & MTD_NO_ERASE)))
671 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
672 * master is an MLC NAND and has a proper pairing scheme defined.
673 * We also reject masters that implement ->_writev() for now, because
674 * NAND controller drivers don't implement this hook, and adding the
675 * SLC -> MLC address/length conversion to this path is useless if we
678 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
679 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
680 !master->pairing || master->_writev))
683 mutex_lock(&mtd_table_mutex);
687 ofidx = of_alias_get_id(np, "mtd");
689 i = idr_alloc(&mtd_idr, mtd, ofidx, ofidx + 1, GFP_KERNEL);
691 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
698 kref_init(&mtd->refcnt);
700 /* default value if not set by driver */
701 if (mtd->bitflip_threshold == 0)
702 mtd->bitflip_threshold = mtd->ecc_strength;
704 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
705 int ngroups = mtd_pairing_groups(master);
707 mtd->erasesize /= ngroups;
708 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
712 if (is_power_of_2(mtd->erasesize))
713 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
715 mtd->erasesize_shift = 0;
717 if (is_power_of_2(mtd->writesize))
718 mtd->writesize_shift = ffs(mtd->writesize) - 1;
720 mtd->writesize_shift = 0;
722 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
723 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
725 /* Some chips always power up locked. Unlock them now */
726 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
727 error = mtd_unlock(mtd, 0, mtd->size);
728 if (error && error != -EOPNOTSUPP)
730 "%s: unlock failed, writes may not work\n",
732 /* Ignore unlock failures? */
736 /* Caller should have set dev.parent to match the
737 * physical device, if appropriate.
739 mtd->dev.type = &mtd_devtype;
740 mtd->dev.class = &mtd_class;
741 mtd->dev.devt = MTD_DEVT(i);
742 dev_set_name(&mtd->dev, "mtd%d", i);
743 dev_set_drvdata(&mtd->dev, mtd);
744 mtd_check_of_node(mtd);
745 of_node_get(mtd_get_of_node(mtd));
746 error = device_register(&mtd->dev);
748 put_device(&mtd->dev);
752 /* Add the nvmem provider */
753 error = mtd_nvmem_add(mtd);
757 mtd_debugfs_populate(mtd);
759 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
762 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
763 /* No need to get a refcount on the module containing
764 the notifier, since we hold the mtd_table_mutex */
765 list_for_each_entry(not, &mtd_notifiers, list)
768 mutex_unlock(&mtd_table_mutex);
770 if (of_property_read_bool(mtd_get_of_node(mtd), "linux,rootfs")) {
771 if (IS_BUILTIN(CONFIG_MTD)) {
772 pr_info("mtd: setting mtd%d (%s) as root device\n", mtd->index, mtd->name);
773 ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
775 pr_warn("mtd: can't set mtd%d (%s) as root device - mtd must be builtin\n",
776 mtd->index, mtd->name);
780 /* We _know_ we aren't being removed, because
781 our caller is still holding us here. So none
782 of this try_ nonsense, and no bitching about it
784 __module_get(THIS_MODULE);
788 device_unregister(&mtd->dev);
790 of_node_put(mtd_get_of_node(mtd));
791 idr_remove(&mtd_idr, i);
793 mutex_unlock(&mtd_table_mutex);
798 * del_mtd_device - unregister an MTD device
799 * @mtd: pointer to MTD device info structure
801 * Remove a device from the list of MTD devices present in the system,
802 * and notify each currently active MTD 'user' of its departure.
803 * Returns zero on success or 1 on failure, which currently will happen
804 * if the requested device does not appear to be present in the list.
807 int del_mtd_device(struct mtd_info *mtd)
810 struct mtd_notifier *not;
812 mutex_lock(&mtd_table_mutex);
814 if (idr_find(&mtd_idr, mtd->index) != mtd) {
819 /* No need to get a refcount on the module containing
820 the notifier, since we hold the mtd_table_mutex */
821 list_for_each_entry(not, &mtd_notifiers, list)
824 kref_put(&mtd->refcnt, mtd_device_release);
828 mutex_unlock(&mtd_table_mutex);
833 * Set a few defaults based on the parent devices, if not provided by the
836 static void mtd_set_dev_defaults(struct mtd_info *mtd)
838 if (mtd->dev.parent) {
839 if (!mtd->owner && mtd->dev.parent->driver)
840 mtd->owner = mtd->dev.parent->driver->owner;
842 mtd->name = dev_name(mtd->dev.parent);
844 pr_debug("mtd device won't show a device symlink in sysfs\n");
847 INIT_LIST_HEAD(&mtd->partitions);
848 mutex_init(&mtd->master.partitions_lock);
849 mutex_init(&mtd->master.chrdev_lock);
852 static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
854 struct otp_info *info;
860 info = kmalloc(PAGE_SIZE, GFP_KERNEL);
865 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info);
867 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info);
871 for (i = 0; i < retlen / sizeof(*info); i++)
872 size += info[i].length;
880 /* ENODATA means there is no OTP region. */
881 return ret == -ENODATA ? 0 : ret;
884 static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
885 const char *compatible,
887 nvmem_reg_read_t reg_read)
889 struct nvmem_device *nvmem = NULL;
890 struct nvmem_config config = {};
891 struct device_node *np;
893 /* DT binding is optional */
894 np = of_get_compatible_child(mtd->dev.of_node, compatible);
896 /* OTP nvmem will be registered on the physical device */
897 config.dev = mtd->dev.parent;
898 config.name = compatible;
899 config.id = NVMEM_DEVID_AUTO;
900 config.owner = THIS_MODULE;
901 config.add_legacy_fixed_of_cells = true;
902 config.type = NVMEM_TYPE_OTP;
903 config.root_only = true;
904 config.ignore_wp = true;
905 config.reg_read = reg_read;
910 nvmem = nvmem_register(&config);
911 /* Just ignore if there is no NVMEM support in the kernel */
912 if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP)
920 static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
921 void *val, size_t bytes)
923 struct mtd_info *mtd = priv;
927 ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val);
931 return retlen == bytes ? 0 : -EIO;
934 static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
935 void *val, size_t bytes)
937 struct mtd_info *mtd = priv;
941 ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val);
945 return retlen == bytes ? 0 : -EIO;
948 static int mtd_otp_nvmem_add(struct mtd_info *mtd)
950 struct device *dev = mtd->dev.parent;
951 struct nvmem_device *nvmem;
955 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
956 size = mtd_otp_size(mtd, true);
961 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
962 mtd_nvmem_user_otp_reg_read);
964 err = PTR_ERR(nvmem);
967 mtd->otp_user_nvmem = nvmem;
971 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
972 size = mtd_otp_size(mtd, false);
980 * The factory OTP contains thing such as a unique serial
981 * number and is small, so let's read it out and put it
982 * into the entropy pool.
986 otp = kmalloc(size, GFP_KERNEL);
991 err = mtd_nvmem_fact_otp_reg_read(mtd, 0, otp, size);
996 add_device_randomness(otp, err);
999 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
1000 mtd_nvmem_fact_otp_reg_read);
1001 if (IS_ERR(nvmem)) {
1002 err = PTR_ERR(nvmem);
1005 mtd->otp_factory_nvmem = nvmem;
1012 nvmem_unregister(mtd->otp_user_nvmem);
1013 return dev_err_probe(dev, err, "Failed to register OTP NVMEM device\n");
1017 * mtd_device_parse_register - parse partitions and register an MTD device.
1019 * @mtd: the MTD device to register
1020 * @types: the list of MTD partition probes to try, see
1021 * 'parse_mtd_partitions()' for more information
1022 * @parser_data: MTD partition parser-specific data
1023 * @parts: fallback partition information to register, if parsing fails;
1024 * only valid if %nr_parts > %0
1025 * @nr_parts: the number of partitions in parts, if zero then the full
1026 * MTD device is registered if no partition info is found
1028 * This function aggregates MTD partitions parsing (done by
1029 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
1030 * basically follows the most common pattern found in many MTD drivers:
1032 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
1034 * * Then It tries to probe partitions on MTD device @mtd using parsers
1035 * specified in @types (if @types is %NULL, then the default list of parsers
1036 * is used, see 'parse_mtd_partitions()' for more information). If none are
1037 * found this functions tries to fallback to information specified in
1039 * * If no partitions were found this function just registers the MTD device
1042 * Returns zero in case of success and a negative error code in case of failure.
1044 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
1045 struct mtd_part_parser_data *parser_data,
1046 const struct mtd_partition *parts,
1051 mtd_set_dev_defaults(mtd);
1053 ret = mtd_otp_nvmem_add(mtd);
1057 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
1058 ret = add_mtd_device(mtd);
1063 /* Prefer parsed partitions over driver-provided fallback */
1064 ret = parse_mtd_partitions(mtd, types, parser_data);
1065 if (ret == -EPROBE_DEFER)
1071 ret = add_mtd_partitions(mtd, parts, nr_parts);
1072 else if (!device_is_registered(&mtd->dev))
1073 ret = add_mtd_device(mtd);
1081 * FIXME: some drivers unfortunately call this function more than once.
1082 * So we have to check if we've already assigned the reboot notifier.
1084 * Generally, we can make multiple calls work for most cases, but it
1085 * does cause problems with parse_mtd_partitions() above (e.g.,
1086 * cmdlineparts will register partitions more than once).
1088 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
1089 "MTD already registered\n");
1090 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
1091 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
1092 register_reboot_notifier(&mtd->reboot_notifier);
1097 nvmem_unregister(mtd->otp_user_nvmem);
1098 nvmem_unregister(mtd->otp_factory_nvmem);
1101 if (ret && device_is_registered(&mtd->dev))
1102 del_mtd_device(mtd);
1106 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
1109 * mtd_device_unregister - unregister an existing MTD device.
1111 * @master: the MTD device to unregister. This will unregister both the master
1112 * and any partitions if registered.
1114 int mtd_device_unregister(struct mtd_info *master)
1118 if (master->_reboot) {
1119 unregister_reboot_notifier(&master->reboot_notifier);
1120 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
1123 nvmem_unregister(master->otp_user_nvmem);
1124 nvmem_unregister(master->otp_factory_nvmem);
1126 err = del_mtd_partitions(master);
1130 if (!device_is_registered(&master->dev))
1133 return del_mtd_device(master);
1135 EXPORT_SYMBOL_GPL(mtd_device_unregister);
1138 * register_mtd_user - register a 'user' of MTD devices.
1139 * @new: pointer to notifier info structure
1141 * Registers a pair of callbacks function to be called upon addition
1142 * or removal of MTD devices. Causes the 'add' callback to be immediately
1143 * invoked for each MTD device currently present in the system.
1145 void register_mtd_user (struct mtd_notifier *new)
1147 struct mtd_info *mtd;
1149 mutex_lock(&mtd_table_mutex);
1151 list_add(&new->list, &mtd_notifiers);
1153 __module_get(THIS_MODULE);
1155 mtd_for_each_device(mtd)
1158 mutex_unlock(&mtd_table_mutex);
1160 EXPORT_SYMBOL_GPL(register_mtd_user);
1163 * unregister_mtd_user - unregister a 'user' of MTD devices.
1164 * @old: pointer to notifier info structure
1166 * Removes a callback function pair from the list of 'users' to be
1167 * notified upon addition or removal of MTD devices. Causes the
1168 * 'remove' callback to be immediately invoked for each MTD device
1169 * currently present in the system.
1171 int unregister_mtd_user (struct mtd_notifier *old)
1173 struct mtd_info *mtd;
1175 mutex_lock(&mtd_table_mutex);
1177 module_put(THIS_MODULE);
1179 mtd_for_each_device(mtd)
1182 list_del(&old->list);
1183 mutex_unlock(&mtd_table_mutex);
1186 EXPORT_SYMBOL_GPL(unregister_mtd_user);
1189 * get_mtd_device - obtain a validated handle for an MTD device
1190 * @mtd: last known address of the required MTD device
1191 * @num: internal device number of the required MTD device
1193 * Given a number and NULL address, return the num'th entry in the device
1194 * table, if any. Given an address and num == -1, search the device table
1195 * for a device with that address and return if it's still present. Given
1196 * both, return the num'th driver only if its address matches. Return
1197 * error code if not.
1199 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
1201 struct mtd_info *ret = NULL, *other;
1204 mutex_lock(&mtd_table_mutex);
1207 mtd_for_each_device(other) {
1213 } else if (num >= 0) {
1214 ret = idr_find(&mtd_idr, num);
1215 if (mtd && mtd != ret)
1224 err = __get_mtd_device(ret);
1228 mutex_unlock(&mtd_table_mutex);
1231 EXPORT_SYMBOL_GPL(get_mtd_device);
1234 int __get_mtd_device(struct mtd_info *mtd)
1236 struct mtd_info *master = mtd_get_master(mtd);
1239 if (master->_get_device) {
1240 err = master->_get_device(mtd);
1245 if (!try_module_get(master->owner)) {
1246 if (master->_put_device)
1247 master->_put_device(master);
1253 kref_get(&mtd->refcnt);
1257 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1258 kref_get(&master->refcnt);
1262 EXPORT_SYMBOL_GPL(__get_mtd_device);
1265 * of_get_mtd_device_by_node - obtain an MTD device associated with a given node
1267 * @np: device tree node
1269 struct mtd_info *of_get_mtd_device_by_node(struct device_node *np)
1271 struct mtd_info *mtd = NULL;
1272 struct mtd_info *tmp;
1275 mutex_lock(&mtd_table_mutex);
1277 err = -EPROBE_DEFER;
1278 mtd_for_each_device(tmp) {
1279 if (mtd_get_of_node(tmp) == np) {
1281 err = __get_mtd_device(mtd);
1286 mutex_unlock(&mtd_table_mutex);
1288 return err ? ERR_PTR(err) : mtd;
1290 EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node);
1293 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1295 * @name: MTD device name to open
1297 * This function returns MTD device description structure in case of
1298 * success and an error code in case of failure.
1300 struct mtd_info *get_mtd_device_nm(const char *name)
1303 struct mtd_info *mtd = NULL, *other;
1305 mutex_lock(&mtd_table_mutex);
1307 mtd_for_each_device(other) {
1308 if (!strcmp(name, other->name)) {
1317 err = __get_mtd_device(mtd);
1321 mutex_unlock(&mtd_table_mutex);
1325 mutex_unlock(&mtd_table_mutex);
1326 return ERR_PTR(err);
1328 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1330 void put_mtd_device(struct mtd_info *mtd)
1332 mutex_lock(&mtd_table_mutex);
1333 __put_mtd_device(mtd);
1334 mutex_unlock(&mtd_table_mutex);
1337 EXPORT_SYMBOL_GPL(put_mtd_device);
1339 void __put_mtd_device(struct mtd_info *mtd)
1341 struct mtd_info *master = mtd_get_master(mtd);
1344 /* kref_put() can relese mtd, so keep a reference mtd->parent */
1345 struct mtd_info *parent = mtd->parent;
1348 kref_put(&mtd->refcnt, mtd_device_release);
1352 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1353 kref_put(&master->refcnt, mtd_device_release);
1355 module_put(master->owner);
1357 /* must be the last as master can be freed in the _put_device */
1358 if (master->_put_device)
1359 master->_put_device(master);
1361 EXPORT_SYMBOL_GPL(__put_mtd_device);
1364 * Erase is an synchronous operation. Device drivers are epected to return a
1365 * negative error code if the operation failed and update instr->fail_addr
1366 * to point the portion that was not properly erased.
1368 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1370 struct mtd_info *master = mtd_get_master(mtd);
1371 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1372 struct erase_info adjinstr;
1375 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1378 if (!mtd->erasesize || !master->_erase)
1381 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1383 if (!(mtd->flags & MTD_WRITEABLE))
1389 ledtrig_mtd_activity();
1391 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1392 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1394 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1395 master->erasesize) -
1399 adjinstr.addr += mst_ofs;
1401 ret = master->_erase(master, &adjinstr);
1403 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1404 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1405 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1406 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1408 instr->fail_addr *= mtd->erasesize;
1414 EXPORT_SYMBOL_GPL(mtd_erase);
1417 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1419 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1420 void **virt, resource_size_t *phys)
1422 struct mtd_info *master = mtd_get_master(mtd);
1428 if (!master->_point)
1430 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1435 from = mtd_get_master_ofs(mtd, from);
1436 return master->_point(master, from, len, retlen, virt, phys);
1438 EXPORT_SYMBOL_GPL(mtd_point);
1440 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1441 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1443 struct mtd_info *master = mtd_get_master(mtd);
1445 if (!master->_unpoint)
1447 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1451 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1453 EXPORT_SYMBOL_GPL(mtd_unpoint);
1456 * Allow NOMMU mmap() to directly map the device (if not NULL)
1457 * - return the address to which the offset maps
1458 * - return -ENOSYS to indicate refusal to do the mapping
1460 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1461 unsigned long offset, unsigned long flags)
1467 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1470 if (retlen != len) {
1471 mtd_unpoint(mtd, offset, retlen);
1474 return (unsigned long)virt;
1476 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1478 static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1479 const struct mtd_ecc_stats *old_stats)
1481 struct mtd_ecc_stats diff;
1486 diff = master->ecc_stats;
1487 diff.failed -= old_stats->failed;
1488 diff.corrected -= old_stats->corrected;
1490 while (mtd->parent) {
1491 mtd->ecc_stats.failed += diff.failed;
1492 mtd->ecc_stats.corrected += diff.corrected;
1497 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1500 struct mtd_oob_ops ops = {
1506 ret = mtd_read_oob(mtd, from, &ops);
1507 *retlen = ops.retlen;
1509 WARN_ON_ONCE(*retlen != len && mtd_is_bitflip_or_eccerr(ret));
1513 EXPORT_SYMBOL_GPL(mtd_read);
1515 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1518 struct mtd_oob_ops ops = {
1520 .datbuf = (u8 *)buf,
1524 ret = mtd_write_oob(mtd, to, &ops);
1525 *retlen = ops.retlen;
1529 EXPORT_SYMBOL_GPL(mtd_write);
1532 * In blackbox flight recorder like scenarios we want to make successful writes
1533 * in interrupt context. panic_write() is only intended to be called when its
1534 * known the kernel is about to panic and we need the write to succeed. Since
1535 * the kernel is not going to be running for much longer, this function can
1536 * break locks and delay to ensure the write succeeds (but not sleep).
1538 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1541 struct mtd_info *master = mtd_get_master(mtd);
1544 if (!master->_panic_write)
1546 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1548 if (!(mtd->flags & MTD_WRITEABLE))
1552 if (!master->oops_panic_write)
1553 master->oops_panic_write = true;
1555 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1558 EXPORT_SYMBOL_GPL(mtd_panic_write);
1560 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1561 struct mtd_oob_ops *ops)
1564 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1565 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1574 if (offs < 0 || offs + ops->len > mtd->size)
1580 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1583 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1584 mtd_div_by_ws(offs, mtd)) *
1585 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1586 if (ops->ooblen > maxooblen)
1593 static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1594 struct mtd_oob_ops *ops)
1596 struct mtd_info *master = mtd_get_master(mtd);
1599 from = mtd_get_master_ofs(mtd, from);
1600 if (master->_read_oob)
1601 ret = master->_read_oob(master, from, ops);
1603 ret = master->_read(master, from, ops->len, &ops->retlen,
1609 static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1610 struct mtd_oob_ops *ops)
1612 struct mtd_info *master = mtd_get_master(mtd);
1615 to = mtd_get_master_ofs(mtd, to);
1616 if (master->_write_oob)
1617 ret = master->_write_oob(master, to, ops);
1619 ret = master->_write(master, to, ops->len, &ops->retlen,
1625 static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1626 struct mtd_oob_ops *ops)
1628 struct mtd_info *master = mtd_get_master(mtd);
1629 int ngroups = mtd_pairing_groups(master);
1630 int npairs = mtd_wunit_per_eb(master) / ngroups;
1631 struct mtd_oob_ops adjops = *ops;
1632 unsigned int wunit, oobavail;
1633 struct mtd_pairing_info info;
1634 int max_bitflips = 0;
1638 ebofs = mtd_mod_by_eb(start, mtd);
1639 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1641 info.pair = mtd_div_by_ws(ebofs, mtd);
1642 pageofs = mtd_mod_by_ws(ebofs, mtd);
1643 oobavail = mtd_oobavail(mtd, ops);
1645 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1648 if (info.pair >= npairs) {
1650 base += master->erasesize;
1653 wunit = mtd_pairing_info_to_wunit(master, &info);
1654 pos = mtd_wunit_to_offset(mtd, base, wunit);
1656 adjops.len = ops->len - ops->retlen;
1657 if (adjops.len > mtd->writesize - pageofs)
1658 adjops.len = mtd->writesize - pageofs;
1660 adjops.ooblen = ops->ooblen - ops->oobretlen;
1661 if (adjops.ooblen > oobavail - adjops.ooboffs)
1662 adjops.ooblen = oobavail - adjops.ooboffs;
1665 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1667 max_bitflips = max(max_bitflips, ret);
1669 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1675 max_bitflips = max(max_bitflips, ret);
1676 ops->retlen += adjops.retlen;
1677 ops->oobretlen += adjops.oobretlen;
1678 adjops.datbuf += adjops.retlen;
1679 adjops.oobbuf += adjops.oobretlen;
1685 return max_bitflips;
1688 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1690 struct mtd_info *master = mtd_get_master(mtd);
1691 struct mtd_ecc_stats old_stats = master->ecc_stats;
1694 ops->retlen = ops->oobretlen = 0;
1696 ret_code = mtd_check_oob_ops(mtd, from, ops);
1700 ledtrig_mtd_activity();
1702 /* Check the validity of a potential fallback on mtd->_read */
1703 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1707 memset(ops->stats, 0, sizeof(*ops->stats));
1709 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1710 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1712 ret_code = mtd_read_oob_std(mtd, from, ops);
1714 mtd_update_ecc_stats(mtd, master, &old_stats);
1717 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1718 * similar to mtd->_read(), returning a non-negative integer
1719 * representing max bitflips. In other cases, mtd->_read_oob() may
1720 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1722 if (unlikely(ret_code < 0))
1724 if (mtd->ecc_strength == 0)
1725 return 0; /* device lacks ecc */
1727 ops->stats->max_bitflips = ret_code;
1728 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1730 EXPORT_SYMBOL_GPL(mtd_read_oob);
1732 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1733 struct mtd_oob_ops *ops)
1735 struct mtd_info *master = mtd_get_master(mtd);
1738 ops->retlen = ops->oobretlen = 0;
1740 if (!(mtd->flags & MTD_WRITEABLE))
1743 ret = mtd_check_oob_ops(mtd, to, ops);
1747 ledtrig_mtd_activity();
1749 /* Check the validity of a potential fallback on mtd->_write */
1750 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1753 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1754 return mtd_io_emulated_slc(mtd, to, false, ops);
1756 return mtd_write_oob_std(mtd, to, ops);
1758 EXPORT_SYMBOL_GPL(mtd_write_oob);
1761 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1762 * @mtd: MTD device structure
1763 * @section: ECC section. Depending on the layout you may have all the ECC
1764 * bytes stored in a single contiguous section, or one section
1765 * per ECC chunk (and sometime several sections for a single ECC
1767 * @oobecc: OOB region struct filled with the appropriate ECC position
1770 * This function returns ECC section information in the OOB area. If you want
1771 * to get all the ECC bytes information, then you should call
1772 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1774 * Returns zero on success, a negative error code otherwise.
1776 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1777 struct mtd_oob_region *oobecc)
1779 struct mtd_info *master = mtd_get_master(mtd);
1781 memset(oobecc, 0, sizeof(*oobecc));
1783 if (!master || section < 0)
1786 if (!master->ooblayout || !master->ooblayout->ecc)
1789 return master->ooblayout->ecc(master, section, oobecc);
1791 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1794 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1796 * @mtd: MTD device structure
1797 * @section: Free section you are interested in. Depending on the layout
1798 * you may have all the free bytes stored in a single contiguous
1799 * section, or one section per ECC chunk plus an extra section
1800 * for the remaining bytes (or other funky layout).
1801 * @oobfree: OOB region struct filled with the appropriate free position
1804 * This function returns free bytes position in the OOB area. If you want
1805 * to get all the free bytes information, then you should call
1806 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1808 * Returns zero on success, a negative error code otherwise.
1810 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1811 struct mtd_oob_region *oobfree)
1813 struct mtd_info *master = mtd_get_master(mtd);
1815 memset(oobfree, 0, sizeof(*oobfree));
1817 if (!master || section < 0)
1820 if (!master->ooblayout || !master->ooblayout->free)
1823 return master->ooblayout->free(master, section, oobfree);
1825 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1828 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1829 * @mtd: mtd info structure
1830 * @byte: the byte we are searching for
1831 * @sectionp: pointer where the section id will be stored
1832 * @oobregion: used to retrieve the ECC position
1833 * @iter: iterator function. Should be either mtd_ooblayout_free or
1834 * mtd_ooblayout_ecc depending on the region type you're searching for
1836 * This function returns the section id and oobregion information of a
1837 * specific byte. For example, say you want to know where the 4th ECC byte is
1838 * stored, you'll use:
1840 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1842 * Returns zero on success, a negative error code otherwise.
1844 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1845 int *sectionp, struct mtd_oob_region *oobregion,
1846 int (*iter)(struct mtd_info *,
1848 struct mtd_oob_region *oobregion))
1850 int pos = 0, ret, section = 0;
1852 memset(oobregion, 0, sizeof(*oobregion));
1855 ret = iter(mtd, section, oobregion);
1859 if (pos + oobregion->length > byte)
1862 pos += oobregion->length;
1867 * Adjust region info to make it start at the beginning at the
1870 oobregion->offset += byte - pos;
1871 oobregion->length -= byte - pos;
1872 *sectionp = section;
1878 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1880 * @mtd: mtd info structure
1881 * @eccbyte: the byte we are searching for
1882 * @section: pointer where the section id will be stored
1883 * @oobregion: OOB region information
1885 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1888 * Returns zero on success, a negative error code otherwise.
1890 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1892 struct mtd_oob_region *oobregion)
1894 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1897 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1900 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1901 * @mtd: mtd info structure
1902 * @buf: destination buffer to store OOB bytes
1903 * @oobbuf: OOB buffer
1904 * @start: first byte to retrieve
1905 * @nbytes: number of bytes to retrieve
1906 * @iter: section iterator
1908 * Extract bytes attached to a specific category (ECC or free)
1909 * from the OOB buffer and copy them into buf.
1911 * Returns zero on success, a negative error code otherwise.
1913 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1914 const u8 *oobbuf, int start, int nbytes,
1915 int (*iter)(struct mtd_info *,
1917 struct mtd_oob_region *oobregion))
1919 struct mtd_oob_region oobregion;
1922 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1928 cnt = min_t(int, nbytes, oobregion.length);
1929 memcpy(buf, oobbuf + oobregion.offset, cnt);
1936 ret = iter(mtd, ++section, &oobregion);
1943 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1944 * @mtd: mtd info structure
1945 * @buf: source buffer to get OOB bytes from
1946 * @oobbuf: OOB buffer
1947 * @start: first OOB byte to set
1948 * @nbytes: number of OOB bytes to set
1949 * @iter: section iterator
1951 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1952 * is selected by passing the appropriate iterator.
1954 * Returns zero on success, a negative error code otherwise.
1956 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1957 u8 *oobbuf, int start, int nbytes,
1958 int (*iter)(struct mtd_info *,
1960 struct mtd_oob_region *oobregion))
1962 struct mtd_oob_region oobregion;
1965 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1971 cnt = min_t(int, nbytes, oobregion.length);
1972 memcpy(oobbuf + oobregion.offset, buf, cnt);
1979 ret = iter(mtd, ++section, &oobregion);
1986 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1987 * @mtd: mtd info structure
1988 * @iter: category iterator
1990 * Count the number of bytes in a given category.
1992 * Returns a positive value on success, a negative error code otherwise.
1994 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1995 int (*iter)(struct mtd_info *,
1997 struct mtd_oob_region *oobregion))
1999 struct mtd_oob_region oobregion;
2000 int section = 0, ret, nbytes = 0;
2003 ret = iter(mtd, section++, &oobregion);
2010 nbytes += oobregion.length;
2017 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
2018 * @mtd: mtd info structure
2019 * @eccbuf: destination buffer to store ECC bytes
2020 * @oobbuf: OOB buffer
2021 * @start: first ECC byte to retrieve
2022 * @nbytes: number of ECC bytes to retrieve
2024 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
2026 * Returns zero on success, a negative error code otherwise.
2028 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
2029 const u8 *oobbuf, int start, int nbytes)
2031 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
2034 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
2037 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
2038 * @mtd: mtd info structure
2039 * @eccbuf: source buffer to get ECC bytes from
2040 * @oobbuf: OOB buffer
2041 * @start: first ECC byte to set
2042 * @nbytes: number of ECC bytes to set
2044 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
2046 * Returns zero on success, a negative error code otherwise.
2048 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
2049 u8 *oobbuf, int start, int nbytes)
2051 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
2054 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
2057 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
2058 * @mtd: mtd info structure
2059 * @databuf: destination buffer to store ECC bytes
2060 * @oobbuf: OOB buffer
2061 * @start: first ECC byte to retrieve
2062 * @nbytes: number of ECC bytes to retrieve
2064 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
2066 * Returns zero on success, a negative error code otherwise.
2068 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
2069 const u8 *oobbuf, int start, int nbytes)
2071 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
2072 mtd_ooblayout_free);
2074 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
2077 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
2078 * @mtd: mtd info structure
2079 * @databuf: source buffer to get data bytes from
2080 * @oobbuf: OOB buffer
2081 * @start: first ECC byte to set
2082 * @nbytes: number of ECC bytes to set
2084 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
2086 * Returns zero on success, a negative error code otherwise.
2088 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
2089 u8 *oobbuf, int start, int nbytes)
2091 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
2092 mtd_ooblayout_free);
2094 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
2097 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
2098 * @mtd: mtd info structure
2100 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
2102 * Returns zero on success, a negative error code otherwise.
2104 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
2106 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
2108 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
2111 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
2112 * @mtd: mtd info structure
2114 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
2116 * Returns zero on success, a negative error code otherwise.
2118 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
2120 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
2122 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
2125 * Method to access the protection register area, present in some flash
2126 * devices. The user data is one time programmable but the factory data is read
2129 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2130 struct otp_info *buf)
2132 struct mtd_info *master = mtd_get_master(mtd);
2134 if (!master->_get_fact_prot_info)
2138 return master->_get_fact_prot_info(master, len, retlen, buf);
2140 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
2142 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2143 size_t *retlen, u_char *buf)
2145 struct mtd_info *master = mtd_get_master(mtd);
2148 if (!master->_read_fact_prot_reg)
2152 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
2154 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
2156 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2157 struct otp_info *buf)
2159 struct mtd_info *master = mtd_get_master(mtd);
2161 if (!master->_get_user_prot_info)
2165 return master->_get_user_prot_info(master, len, retlen, buf);
2167 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
2169 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2170 size_t *retlen, u_char *buf)
2172 struct mtd_info *master = mtd_get_master(mtd);
2175 if (!master->_read_user_prot_reg)
2179 return master->_read_user_prot_reg(master, from, len, retlen, buf);
2181 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
2183 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
2184 size_t *retlen, const u_char *buf)
2186 struct mtd_info *master = mtd_get_master(mtd);
2190 if (!master->_write_user_prot_reg)
2194 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
2199 * If no data could be written at all, we are out of memory and
2200 * must return -ENOSPC.
2202 return (*retlen) ? 0 : -ENOSPC;
2204 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
2206 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2208 struct mtd_info *master = mtd_get_master(mtd);
2210 if (!master->_lock_user_prot_reg)
2214 return master->_lock_user_prot_reg(master, from, len);
2216 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
2218 int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2220 struct mtd_info *master = mtd_get_master(mtd);
2222 if (!master->_erase_user_prot_reg)
2226 return master->_erase_user_prot_reg(master, from, len);
2228 EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
2230 /* Chip-supported device locking */
2231 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2233 struct mtd_info *master = mtd_get_master(mtd);
2237 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2242 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2243 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2244 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2247 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
2249 EXPORT_SYMBOL_GPL(mtd_lock);
2251 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2253 struct mtd_info *master = mtd_get_master(mtd);
2255 if (!master->_unlock)
2257 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2262 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2263 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2264 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2267 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
2269 EXPORT_SYMBOL_GPL(mtd_unlock);
2271 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2273 struct mtd_info *master = mtd_get_master(mtd);
2275 if (!master->_is_locked)
2277 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2282 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2283 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2284 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2287 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
2289 EXPORT_SYMBOL_GPL(mtd_is_locked);
2291 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2293 struct mtd_info *master = mtd_get_master(mtd);
2295 if (ofs < 0 || ofs >= mtd->size)
2297 if (!master->_block_isreserved)
2300 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2301 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2303 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2305 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2307 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2309 struct mtd_info *master = mtd_get_master(mtd);
2311 if (ofs < 0 || ofs >= mtd->size)
2313 if (!master->_block_isbad)
2316 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2317 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2319 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2321 EXPORT_SYMBOL_GPL(mtd_block_isbad);
2323 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2325 struct mtd_info *master = mtd_get_master(mtd);
2328 if (!master->_block_markbad)
2330 if (ofs < 0 || ofs >= mtd->size)
2332 if (!(mtd->flags & MTD_WRITEABLE))
2335 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2336 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2338 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2342 while (mtd->parent) {
2343 mtd->ecc_stats.badblocks++;
2349 EXPORT_SYMBOL_GPL(mtd_block_markbad);
2352 * default_mtd_writev - the default writev method
2353 * @mtd: mtd device description object pointer
2354 * @vecs: the vectors to write
2355 * @count: count of vectors in @vecs
2356 * @to: the MTD device offset to write to
2357 * @retlen: on exit contains the count of bytes written to the MTD device.
2359 * This function returns zero in case of success and a negative error code in
2362 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2363 unsigned long count, loff_t to, size_t *retlen)
2366 size_t totlen = 0, thislen;
2369 for (i = 0; i < count; i++) {
2370 if (!vecs[i].iov_len)
2372 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2375 if (ret || thislen != vecs[i].iov_len)
2377 to += vecs[i].iov_len;
2384 * mtd_writev - the vector-based MTD write method
2385 * @mtd: mtd device description object pointer
2386 * @vecs: the vectors to write
2387 * @count: count of vectors in @vecs
2388 * @to: the MTD device offset to write to
2389 * @retlen: on exit contains the count of bytes written to the MTD device.
2391 * This function returns zero in case of success and a negative error code in
2394 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2395 unsigned long count, loff_t to, size_t *retlen)
2397 struct mtd_info *master = mtd_get_master(mtd);
2400 if (!(mtd->flags & MTD_WRITEABLE))
2403 if (!master->_writev)
2404 return default_mtd_writev(mtd, vecs, count, to, retlen);
2406 return master->_writev(master, vecs, count,
2407 mtd_get_master_ofs(mtd, to), retlen);
2409 EXPORT_SYMBOL_GPL(mtd_writev);
2412 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2413 * @mtd: mtd device description object pointer
2414 * @size: a pointer to the ideal or maximum size of the allocation, points
2415 * to the actual allocation size on success.
2417 * This routine attempts to allocate a contiguous kernel buffer up to
2418 * the specified size, backing off the size of the request exponentially
2419 * until the request succeeds or until the allocation size falls below
2420 * the system page size. This attempts to make sure it does not adversely
2421 * impact system performance, so when allocating more than one page, we
2422 * ask the memory allocator to avoid re-trying, swapping, writing back
2423 * or performing I/O.
2425 * Note, this function also makes sure that the allocated buffer is aligned to
2426 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2428 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2429 * to handle smaller (i.e. degraded) buffer allocations under low- or
2430 * fragmented-memory situations where such reduced allocations, from a
2431 * requested ideal, are allowed.
2433 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2435 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2437 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2438 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2441 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2443 while (*size > min_alloc) {
2444 kbuf = kmalloc(*size, flags);
2449 *size = ALIGN(*size, mtd->writesize);
2453 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2454 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2456 return kmalloc(*size, GFP_KERNEL);
2458 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2460 #ifdef CONFIG_PROC_FS
2462 /*====================================================================*/
2463 /* Support for /proc/mtd */
2465 static int mtd_proc_show(struct seq_file *m, void *v)
2467 struct mtd_info *mtd;
2469 seq_puts(m, "dev: size erasesize name\n");
2470 mutex_lock(&mtd_table_mutex);
2471 mtd_for_each_device(mtd) {
2472 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2473 mtd->index, (unsigned long long)mtd->size,
2474 mtd->erasesize, mtd->name);
2476 mutex_unlock(&mtd_table_mutex);
2479 #endif /* CONFIG_PROC_FS */
2481 /*====================================================================*/
2484 static struct backing_dev_info * __init mtd_bdi_init(const char *name)
2486 struct backing_dev_info *bdi;
2489 bdi = bdi_alloc(NUMA_NO_NODE);
2491 return ERR_PTR(-ENOMEM);
2496 * We put '-0' suffix to the name to get the same name format as we
2497 * used to get. Since this is called only once, we get a unique name.
2499 ret = bdi_register(bdi, "%.28s-0", name);
2503 return ret ? ERR_PTR(ret) : bdi;
2506 static struct proc_dir_entry *proc_mtd;
2508 static int __init init_mtd(void)
2512 ret = class_register(&mtd_class);
2516 mtd_bdi = mtd_bdi_init("mtd");
2517 if (IS_ERR(mtd_bdi)) {
2518 ret = PTR_ERR(mtd_bdi);
2522 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2524 ret = init_mtdchar();
2528 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2529 debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd,
2530 &mtd_expert_analysis_mode);
2536 remove_proc_entry("mtd", NULL);
2537 bdi_unregister(mtd_bdi);
2540 class_unregister(&mtd_class);
2542 pr_err("Error registering mtd class or bdi: %d\n", ret);
2546 static void __exit cleanup_mtd(void)
2548 debugfs_remove_recursive(dfs_dir_mtd);
2551 remove_proc_entry("mtd", NULL);
2552 class_unregister(&mtd_class);
2553 bdi_unregister(mtd_bdi);
2555 idr_destroy(&mtd_idr);
2558 module_init(init_mtd);
2559 module_exit(cleanup_mtd);
2561 MODULE_LICENSE("GPL");
2562 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2563 MODULE_DESCRIPTION("Core MTD registration and access routines");