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);
550 * add_mtd_device - register an MTD device
551 * @mtd: pointer to new MTD device info structure
553 * Add a device to the list of MTD devices present in the system, and
554 * notify each currently active MTD 'user' of its arrival. Returns
555 * zero on success or non-zero on failure.
558 int add_mtd_device(struct mtd_info *mtd)
560 struct mtd_info *master = mtd_get_master(mtd);
561 struct mtd_notifier *not;
565 * May occur, for instance, on buggy drivers which call
566 * mtd_device_parse_register() multiple times on the same master MTD,
567 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
569 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
572 BUG_ON(mtd->writesize == 0);
575 * MTD drivers should implement ->_{write,read}() or
576 * ->_{write,read}_oob(), but not both.
578 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
579 (mtd->_read && mtd->_read_oob)))
582 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
583 !(mtd->flags & MTD_NO_ERASE)))
587 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
588 * master is an MLC NAND and has a proper pairing scheme defined.
589 * We also reject masters that implement ->_writev() for now, because
590 * NAND controller drivers don't implement this hook, and adding the
591 * SLC -> MLC address/length conversion to this path is useless if we
594 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
595 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
596 !master->pairing || master->_writev))
599 mutex_lock(&mtd_table_mutex);
601 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
610 /* default value if not set by driver */
611 if (mtd->bitflip_threshold == 0)
612 mtd->bitflip_threshold = mtd->ecc_strength;
614 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
615 int ngroups = mtd_pairing_groups(master);
617 mtd->erasesize /= ngroups;
618 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
622 if (is_power_of_2(mtd->erasesize))
623 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
625 mtd->erasesize_shift = 0;
627 if (is_power_of_2(mtd->writesize))
628 mtd->writesize_shift = ffs(mtd->writesize) - 1;
630 mtd->writesize_shift = 0;
632 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
633 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
635 /* Some chips always power up locked. Unlock them now */
636 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
637 error = mtd_unlock(mtd, 0, mtd->size);
638 if (error && error != -EOPNOTSUPP)
640 "%s: unlock failed, writes may not work\n",
642 /* Ignore unlock failures? */
646 /* Caller should have set dev.parent to match the
647 * physical device, if appropriate.
649 mtd->dev.type = &mtd_devtype;
650 mtd->dev.class = &mtd_class;
651 mtd->dev.devt = MTD_DEVT(i);
652 dev_set_name(&mtd->dev, "mtd%d", i);
653 dev_set_drvdata(&mtd->dev, mtd);
654 of_node_get(mtd_get_of_node(mtd));
655 error = device_register(&mtd->dev);
659 /* Add the nvmem provider */
660 error = mtd_nvmem_add(mtd);
664 mtd_debugfs_populate(mtd);
666 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
669 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
670 /* No need to get a refcount on the module containing
671 the notifier, since we hold the mtd_table_mutex */
672 list_for_each_entry(not, &mtd_notifiers, list)
675 mutex_unlock(&mtd_table_mutex);
676 /* We _know_ we aren't being removed, because
677 our caller is still holding us here. So none
678 of this try_ nonsense, and no bitching about it
680 __module_get(THIS_MODULE);
684 device_unregister(&mtd->dev);
686 of_node_put(mtd_get_of_node(mtd));
687 idr_remove(&mtd_idr, i);
689 mutex_unlock(&mtd_table_mutex);
694 * del_mtd_device - unregister an MTD device
695 * @mtd: pointer to MTD device info structure
697 * Remove a device from the list of MTD devices present in the system,
698 * and notify each currently active MTD 'user' of its departure.
699 * Returns zero on success or 1 on failure, which currently will happen
700 * if the requested device does not appear to be present in the list.
703 int del_mtd_device(struct mtd_info *mtd)
706 struct mtd_notifier *not;
708 mutex_lock(&mtd_table_mutex);
710 if (idr_find(&mtd_idr, mtd->index) != mtd) {
715 /* No need to get a refcount on the module containing
716 the notifier, since we hold the mtd_table_mutex */
717 list_for_each_entry(not, &mtd_notifiers, list)
721 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
722 mtd->index, mtd->name, mtd->usecount);
725 debugfs_remove_recursive(mtd->dbg.dfs_dir);
727 /* Try to remove the NVMEM provider */
729 nvmem_unregister(mtd->nvmem);
731 device_unregister(&mtd->dev);
733 /* Clear dev so mtd can be safely re-registered later if desired */
734 memset(&mtd->dev, 0, sizeof(mtd->dev));
736 idr_remove(&mtd_idr, mtd->index);
737 of_node_put(mtd_get_of_node(mtd));
739 module_put(THIS_MODULE);
744 mutex_unlock(&mtd_table_mutex);
749 * Set a few defaults based on the parent devices, if not provided by the
752 static void mtd_set_dev_defaults(struct mtd_info *mtd)
754 if (mtd->dev.parent) {
755 if (!mtd->owner && mtd->dev.parent->driver)
756 mtd->owner = mtd->dev.parent->driver->owner;
758 mtd->name = dev_name(mtd->dev.parent);
760 pr_debug("mtd device won't show a device symlink in sysfs\n");
763 INIT_LIST_HEAD(&mtd->partitions);
764 mutex_init(&mtd->master.partitions_lock);
765 mutex_init(&mtd->master.chrdev_lock);
768 static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
770 struct otp_info *info;
776 info = kmalloc(PAGE_SIZE, GFP_KERNEL);
781 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info);
783 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info);
787 for (i = 0; i < retlen / sizeof(*info); i++)
788 size += info[i].length;
796 /* ENODATA means there is no OTP region. */
797 return ret == -ENODATA ? 0 : ret;
800 static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
801 const char *compatible,
803 nvmem_reg_read_t reg_read)
805 struct nvmem_device *nvmem = NULL;
806 struct nvmem_config config = {};
807 struct device_node *np;
809 /* DT binding is optional */
810 np = of_get_compatible_child(mtd->dev.of_node, compatible);
812 /* OTP nvmem will be registered on the physical device */
813 config.dev = mtd->dev.parent;
814 config.name = kasprintf(GFP_KERNEL, "%s-%s", dev_name(&mtd->dev), compatible);
815 config.id = NVMEM_DEVID_NONE;
816 config.owner = THIS_MODULE;
817 config.type = NVMEM_TYPE_OTP;
818 config.root_only = true;
819 config.ignore_wp = true;
820 config.reg_read = reg_read;
825 nvmem = nvmem_register(&config);
826 /* Just ignore if there is no NVMEM support in the kernel */
827 if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP)
836 static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
837 void *val, size_t bytes)
839 struct mtd_info *mtd = priv;
843 ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val);
847 return retlen == bytes ? 0 : -EIO;
850 static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
851 void *val, size_t bytes)
853 struct mtd_info *mtd = priv;
857 ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val);
861 return retlen == bytes ? 0 : -EIO;
864 static int mtd_otp_nvmem_add(struct mtd_info *mtd)
866 struct nvmem_device *nvmem;
870 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
871 size = mtd_otp_size(mtd, true);
876 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
877 mtd_nvmem_user_otp_reg_read);
879 dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
880 return PTR_ERR(nvmem);
882 mtd->otp_user_nvmem = nvmem;
886 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
887 size = mtd_otp_size(mtd, false);
894 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
895 mtd_nvmem_fact_otp_reg_read);
897 dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
898 err = PTR_ERR(nvmem);
901 mtd->otp_factory_nvmem = nvmem;
908 if (mtd->otp_user_nvmem)
909 nvmem_unregister(mtd->otp_user_nvmem);
914 * mtd_device_parse_register - parse partitions and register an MTD device.
916 * @mtd: the MTD device to register
917 * @types: the list of MTD partition probes to try, see
918 * 'parse_mtd_partitions()' for more information
919 * @parser_data: MTD partition parser-specific data
920 * @parts: fallback partition information to register, if parsing fails;
921 * only valid if %nr_parts > %0
922 * @nr_parts: the number of partitions in parts, if zero then the full
923 * MTD device is registered if no partition info is found
925 * This function aggregates MTD partitions parsing (done by
926 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
927 * basically follows the most common pattern found in many MTD drivers:
929 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
931 * * Then It tries to probe partitions on MTD device @mtd using parsers
932 * specified in @types (if @types is %NULL, then the default list of parsers
933 * is used, see 'parse_mtd_partitions()' for more information). If none are
934 * found this functions tries to fallback to information specified in
936 * * If no partitions were found this function just registers the MTD device
939 * Returns zero in case of success and a negative error code in case of failure.
941 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
942 struct mtd_part_parser_data *parser_data,
943 const struct mtd_partition *parts,
948 mtd_set_dev_defaults(mtd);
950 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
951 ret = add_mtd_device(mtd);
956 /* Prefer parsed partitions over driver-provided fallback */
957 ret = parse_mtd_partitions(mtd, types, parser_data);
958 if (ret == -EPROBE_DEFER)
964 ret = add_mtd_partitions(mtd, parts, nr_parts);
965 else if (!device_is_registered(&mtd->dev))
966 ret = add_mtd_device(mtd);
974 * FIXME: some drivers unfortunately call this function more than once.
975 * So we have to check if we've already assigned the reboot notifier.
977 * Generally, we can make multiple calls work for most cases, but it
978 * does cause problems with parse_mtd_partitions() above (e.g.,
979 * cmdlineparts will register partitions more than once).
981 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
982 "MTD already registered\n");
983 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
984 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
985 register_reboot_notifier(&mtd->reboot_notifier);
988 ret = mtd_otp_nvmem_add(mtd);
991 if (ret && device_is_registered(&mtd->dev))
996 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
999 * mtd_device_unregister - unregister an existing MTD device.
1001 * @master: the MTD device to unregister. This will unregister both the master
1002 * and any partitions if registered.
1004 int mtd_device_unregister(struct mtd_info *master)
1008 if (master->_reboot) {
1009 unregister_reboot_notifier(&master->reboot_notifier);
1010 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
1013 if (master->otp_user_nvmem)
1014 nvmem_unregister(master->otp_user_nvmem);
1016 if (master->otp_factory_nvmem)
1017 nvmem_unregister(master->otp_factory_nvmem);
1019 err = del_mtd_partitions(master);
1023 if (!device_is_registered(&master->dev))
1026 return del_mtd_device(master);
1028 EXPORT_SYMBOL_GPL(mtd_device_unregister);
1031 * register_mtd_user - register a 'user' of MTD devices.
1032 * @new: pointer to notifier info structure
1034 * Registers a pair of callbacks function to be called upon addition
1035 * or removal of MTD devices. Causes the 'add' callback to be immediately
1036 * invoked for each MTD device currently present in the system.
1038 void register_mtd_user (struct mtd_notifier *new)
1040 struct mtd_info *mtd;
1042 mutex_lock(&mtd_table_mutex);
1044 list_add(&new->list, &mtd_notifiers);
1046 __module_get(THIS_MODULE);
1048 mtd_for_each_device(mtd)
1051 mutex_unlock(&mtd_table_mutex);
1053 EXPORT_SYMBOL_GPL(register_mtd_user);
1056 * unregister_mtd_user - unregister a 'user' of MTD devices.
1057 * @old: pointer to notifier info structure
1059 * Removes a callback function pair from the list of 'users' to be
1060 * notified upon addition or removal of MTD devices. Causes the
1061 * 'remove' callback to be immediately invoked for each MTD device
1062 * currently present in the system.
1064 int unregister_mtd_user (struct mtd_notifier *old)
1066 struct mtd_info *mtd;
1068 mutex_lock(&mtd_table_mutex);
1070 module_put(THIS_MODULE);
1072 mtd_for_each_device(mtd)
1075 list_del(&old->list);
1076 mutex_unlock(&mtd_table_mutex);
1079 EXPORT_SYMBOL_GPL(unregister_mtd_user);
1082 * get_mtd_device - obtain a validated handle for an MTD device
1083 * @mtd: last known address of the required MTD device
1084 * @num: internal device number of the required MTD device
1086 * Given a number and NULL address, return the num'th entry in the device
1087 * table, if any. Given an address and num == -1, search the device table
1088 * for a device with that address and return if it's still present. Given
1089 * both, return the num'th driver only if its address matches. Return
1090 * error code if not.
1092 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
1094 struct mtd_info *ret = NULL, *other;
1097 mutex_lock(&mtd_table_mutex);
1100 mtd_for_each_device(other) {
1106 } else if (num >= 0) {
1107 ret = idr_find(&mtd_idr, num);
1108 if (mtd && mtd != ret)
1117 err = __get_mtd_device(ret);
1121 mutex_unlock(&mtd_table_mutex);
1124 EXPORT_SYMBOL_GPL(get_mtd_device);
1127 int __get_mtd_device(struct mtd_info *mtd)
1129 struct mtd_info *master = mtd_get_master(mtd);
1132 if (!try_module_get(master->owner))
1135 if (master->_get_device) {
1136 err = master->_get_device(mtd);
1139 module_put(master->owner);
1146 while (mtd->parent) {
1153 EXPORT_SYMBOL_GPL(__get_mtd_device);
1156 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1158 * @name: MTD device name to open
1160 * This function returns MTD device description structure in case of
1161 * success and an error code in case of failure.
1163 struct mtd_info *get_mtd_device_nm(const char *name)
1166 struct mtd_info *mtd = NULL, *other;
1168 mutex_lock(&mtd_table_mutex);
1170 mtd_for_each_device(other) {
1171 if (!strcmp(name, other->name)) {
1180 err = __get_mtd_device(mtd);
1184 mutex_unlock(&mtd_table_mutex);
1188 mutex_unlock(&mtd_table_mutex);
1189 return ERR_PTR(err);
1191 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1193 void put_mtd_device(struct mtd_info *mtd)
1195 mutex_lock(&mtd_table_mutex);
1196 __put_mtd_device(mtd);
1197 mutex_unlock(&mtd_table_mutex);
1200 EXPORT_SYMBOL_GPL(put_mtd_device);
1202 void __put_mtd_device(struct mtd_info *mtd)
1204 struct mtd_info *master = mtd_get_master(mtd);
1206 while (mtd->parent) {
1208 BUG_ON(mtd->usecount < 0);
1214 if (master->_put_device)
1215 master->_put_device(master);
1217 module_put(master->owner);
1219 EXPORT_SYMBOL_GPL(__put_mtd_device);
1222 * Erase is an synchronous operation. Device drivers are epected to return a
1223 * negative error code if the operation failed and update instr->fail_addr
1224 * to point the portion that was not properly erased.
1226 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1228 struct mtd_info *master = mtd_get_master(mtd);
1229 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1230 struct erase_info adjinstr;
1233 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1236 if (!mtd->erasesize || !master->_erase)
1239 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1241 if (!(mtd->flags & MTD_WRITEABLE))
1247 ledtrig_mtd_activity();
1249 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1250 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1252 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1253 master->erasesize) -
1257 adjinstr.addr += mst_ofs;
1259 ret = master->_erase(master, &adjinstr);
1261 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1262 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1263 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1264 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1266 instr->fail_addr *= mtd->erasesize;
1272 EXPORT_SYMBOL_GPL(mtd_erase);
1275 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1277 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1278 void **virt, resource_size_t *phys)
1280 struct mtd_info *master = mtd_get_master(mtd);
1286 if (!master->_point)
1288 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1293 from = mtd_get_master_ofs(mtd, from);
1294 return master->_point(master, from, len, retlen, virt, phys);
1296 EXPORT_SYMBOL_GPL(mtd_point);
1298 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1299 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1301 struct mtd_info *master = mtd_get_master(mtd);
1303 if (!master->_unpoint)
1305 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1309 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1311 EXPORT_SYMBOL_GPL(mtd_unpoint);
1314 * Allow NOMMU mmap() to directly map the device (if not NULL)
1315 * - return the address to which the offset maps
1316 * - return -ENOSYS to indicate refusal to do the mapping
1318 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1319 unsigned long offset, unsigned long flags)
1325 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1328 if (retlen != len) {
1329 mtd_unpoint(mtd, offset, retlen);
1332 return (unsigned long)virt;
1334 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1336 static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1337 const struct mtd_ecc_stats *old_stats)
1339 struct mtd_ecc_stats diff;
1344 diff = master->ecc_stats;
1345 diff.failed -= old_stats->failed;
1346 diff.corrected -= old_stats->corrected;
1348 while (mtd->parent) {
1349 mtd->ecc_stats.failed += diff.failed;
1350 mtd->ecc_stats.corrected += diff.corrected;
1355 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1358 struct mtd_oob_ops ops = {
1364 ret = mtd_read_oob(mtd, from, &ops);
1365 *retlen = ops.retlen;
1369 EXPORT_SYMBOL_GPL(mtd_read);
1371 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1374 struct mtd_oob_ops ops = {
1376 .datbuf = (u8 *)buf,
1380 ret = mtd_write_oob(mtd, to, &ops);
1381 *retlen = ops.retlen;
1385 EXPORT_SYMBOL_GPL(mtd_write);
1388 * In blackbox flight recorder like scenarios we want to make successful writes
1389 * in interrupt context. panic_write() is only intended to be called when its
1390 * known the kernel is about to panic and we need the write to succeed. Since
1391 * the kernel is not going to be running for much longer, this function can
1392 * break locks and delay to ensure the write succeeds (but not sleep).
1394 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1397 struct mtd_info *master = mtd_get_master(mtd);
1400 if (!master->_panic_write)
1402 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1404 if (!(mtd->flags & MTD_WRITEABLE))
1408 if (!master->oops_panic_write)
1409 master->oops_panic_write = true;
1411 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1414 EXPORT_SYMBOL_GPL(mtd_panic_write);
1416 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1417 struct mtd_oob_ops *ops)
1420 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1421 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1430 if (offs < 0 || offs + ops->len > mtd->size)
1436 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1439 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1440 mtd_div_by_ws(offs, mtd)) *
1441 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1442 if (ops->ooblen > maxooblen)
1449 static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1450 struct mtd_oob_ops *ops)
1452 struct mtd_info *master = mtd_get_master(mtd);
1455 from = mtd_get_master_ofs(mtd, from);
1456 if (master->_read_oob)
1457 ret = master->_read_oob(master, from, ops);
1459 ret = master->_read(master, from, ops->len, &ops->retlen,
1465 static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1466 struct mtd_oob_ops *ops)
1468 struct mtd_info *master = mtd_get_master(mtd);
1471 to = mtd_get_master_ofs(mtd, to);
1472 if (master->_write_oob)
1473 ret = master->_write_oob(master, to, ops);
1475 ret = master->_write(master, to, ops->len, &ops->retlen,
1481 static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1482 struct mtd_oob_ops *ops)
1484 struct mtd_info *master = mtd_get_master(mtd);
1485 int ngroups = mtd_pairing_groups(master);
1486 int npairs = mtd_wunit_per_eb(master) / ngroups;
1487 struct mtd_oob_ops adjops = *ops;
1488 unsigned int wunit, oobavail;
1489 struct mtd_pairing_info info;
1490 int max_bitflips = 0;
1494 ebofs = mtd_mod_by_eb(start, mtd);
1495 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1497 info.pair = mtd_div_by_ws(ebofs, mtd);
1498 pageofs = mtd_mod_by_ws(ebofs, mtd);
1499 oobavail = mtd_oobavail(mtd, ops);
1501 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1504 if (info.pair >= npairs) {
1506 base += master->erasesize;
1509 wunit = mtd_pairing_info_to_wunit(master, &info);
1510 pos = mtd_wunit_to_offset(mtd, base, wunit);
1512 adjops.len = ops->len - ops->retlen;
1513 if (adjops.len > mtd->writesize - pageofs)
1514 adjops.len = mtd->writesize - pageofs;
1516 adjops.ooblen = ops->ooblen - ops->oobretlen;
1517 if (adjops.ooblen > oobavail - adjops.ooboffs)
1518 adjops.ooblen = oobavail - adjops.ooboffs;
1521 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1523 max_bitflips = max(max_bitflips, ret);
1525 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1531 max_bitflips = max(max_bitflips, ret);
1532 ops->retlen += adjops.retlen;
1533 ops->oobretlen += adjops.oobretlen;
1534 adjops.datbuf += adjops.retlen;
1535 adjops.oobbuf += adjops.oobretlen;
1541 return max_bitflips;
1544 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1546 struct mtd_info *master = mtd_get_master(mtd);
1547 struct mtd_ecc_stats old_stats = master->ecc_stats;
1550 ops->retlen = ops->oobretlen = 0;
1552 ret_code = mtd_check_oob_ops(mtd, from, ops);
1556 ledtrig_mtd_activity();
1558 /* Check the validity of a potential fallback on mtd->_read */
1559 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1562 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1563 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1565 ret_code = mtd_read_oob_std(mtd, from, ops);
1567 mtd_update_ecc_stats(mtd, master, &old_stats);
1570 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1571 * similar to mtd->_read(), returning a non-negative integer
1572 * representing max bitflips. In other cases, mtd->_read_oob() may
1573 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1575 if (unlikely(ret_code < 0))
1577 if (mtd->ecc_strength == 0)
1578 return 0; /* device lacks ecc */
1579 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1581 EXPORT_SYMBOL_GPL(mtd_read_oob);
1583 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1584 struct mtd_oob_ops *ops)
1586 struct mtd_info *master = mtd_get_master(mtd);
1589 ops->retlen = ops->oobretlen = 0;
1591 if (!(mtd->flags & MTD_WRITEABLE))
1594 ret = mtd_check_oob_ops(mtd, to, ops);
1598 ledtrig_mtd_activity();
1600 /* Check the validity of a potential fallback on mtd->_write */
1601 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1604 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1605 return mtd_io_emulated_slc(mtd, to, false, ops);
1607 return mtd_write_oob_std(mtd, to, ops);
1609 EXPORT_SYMBOL_GPL(mtd_write_oob);
1612 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1613 * @mtd: MTD device structure
1614 * @section: ECC section. Depending on the layout you may have all the ECC
1615 * bytes stored in a single contiguous section, or one section
1616 * per ECC chunk (and sometime several sections for a single ECC
1618 * @oobecc: OOB region struct filled with the appropriate ECC position
1621 * This function returns ECC section information in the OOB area. If you want
1622 * to get all the ECC bytes information, then you should call
1623 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1625 * Returns zero on success, a negative error code otherwise.
1627 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1628 struct mtd_oob_region *oobecc)
1630 struct mtd_info *master = mtd_get_master(mtd);
1632 memset(oobecc, 0, sizeof(*oobecc));
1634 if (!master || section < 0)
1637 if (!master->ooblayout || !master->ooblayout->ecc)
1640 return master->ooblayout->ecc(master, section, oobecc);
1642 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1645 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1647 * @mtd: MTD device structure
1648 * @section: Free section you are interested in. Depending on the layout
1649 * you may have all the free bytes stored in a single contiguous
1650 * section, or one section per ECC chunk plus an extra section
1651 * for the remaining bytes (or other funky layout).
1652 * @oobfree: OOB region struct filled with the appropriate free position
1655 * This function returns free bytes position in the OOB area. If you want
1656 * to get all the free bytes information, then you should call
1657 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1659 * Returns zero on success, a negative error code otherwise.
1661 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1662 struct mtd_oob_region *oobfree)
1664 struct mtd_info *master = mtd_get_master(mtd);
1666 memset(oobfree, 0, sizeof(*oobfree));
1668 if (!master || section < 0)
1671 if (!master->ooblayout || !master->ooblayout->free)
1674 return master->ooblayout->free(master, section, oobfree);
1676 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1679 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1680 * @mtd: mtd info structure
1681 * @byte: the byte we are searching for
1682 * @sectionp: pointer where the section id will be stored
1683 * @oobregion: used to retrieve the ECC position
1684 * @iter: iterator function. Should be either mtd_ooblayout_free or
1685 * mtd_ooblayout_ecc depending on the region type you're searching for
1687 * This function returns the section id and oobregion information of a
1688 * specific byte. For example, say you want to know where the 4th ECC byte is
1689 * stored, you'll use:
1691 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1693 * Returns zero on success, a negative error code otherwise.
1695 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1696 int *sectionp, struct mtd_oob_region *oobregion,
1697 int (*iter)(struct mtd_info *,
1699 struct mtd_oob_region *oobregion))
1701 int pos = 0, ret, section = 0;
1703 memset(oobregion, 0, sizeof(*oobregion));
1706 ret = iter(mtd, section, oobregion);
1710 if (pos + oobregion->length > byte)
1713 pos += oobregion->length;
1718 * Adjust region info to make it start at the beginning at the
1721 oobregion->offset += byte - pos;
1722 oobregion->length -= byte - pos;
1723 *sectionp = section;
1729 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1731 * @mtd: mtd info structure
1732 * @eccbyte: the byte we are searching for
1733 * @section: pointer where the section id will be stored
1734 * @oobregion: OOB region information
1736 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1739 * Returns zero on success, a negative error code otherwise.
1741 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1743 struct mtd_oob_region *oobregion)
1745 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1748 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1751 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1752 * @mtd: mtd info structure
1753 * @buf: destination buffer to store OOB bytes
1754 * @oobbuf: OOB buffer
1755 * @start: first byte to retrieve
1756 * @nbytes: number of bytes to retrieve
1757 * @iter: section iterator
1759 * Extract bytes attached to a specific category (ECC or free)
1760 * from the OOB buffer and copy them into buf.
1762 * Returns zero on success, a negative error code otherwise.
1764 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1765 const u8 *oobbuf, int start, int nbytes,
1766 int (*iter)(struct mtd_info *,
1768 struct mtd_oob_region *oobregion))
1770 struct mtd_oob_region oobregion;
1773 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1779 cnt = min_t(int, nbytes, oobregion.length);
1780 memcpy(buf, oobbuf + oobregion.offset, cnt);
1787 ret = iter(mtd, ++section, &oobregion);
1794 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1795 * @mtd: mtd info structure
1796 * @buf: source buffer to get OOB bytes from
1797 * @oobbuf: OOB buffer
1798 * @start: first OOB byte to set
1799 * @nbytes: number of OOB bytes to set
1800 * @iter: section iterator
1802 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1803 * is selected by passing the appropriate iterator.
1805 * Returns zero on success, a negative error code otherwise.
1807 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1808 u8 *oobbuf, int start, int nbytes,
1809 int (*iter)(struct mtd_info *,
1811 struct mtd_oob_region *oobregion))
1813 struct mtd_oob_region oobregion;
1816 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1822 cnt = min_t(int, nbytes, oobregion.length);
1823 memcpy(oobbuf + oobregion.offset, buf, cnt);
1830 ret = iter(mtd, ++section, &oobregion);
1837 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1838 * @mtd: mtd info structure
1839 * @iter: category iterator
1841 * Count the number of bytes in a given category.
1843 * Returns a positive value on success, a negative error code otherwise.
1845 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1846 int (*iter)(struct mtd_info *,
1848 struct mtd_oob_region *oobregion))
1850 struct mtd_oob_region oobregion;
1851 int section = 0, ret, nbytes = 0;
1854 ret = iter(mtd, section++, &oobregion);
1861 nbytes += oobregion.length;
1868 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1869 * @mtd: mtd info structure
1870 * @eccbuf: destination buffer to store ECC bytes
1871 * @oobbuf: OOB buffer
1872 * @start: first ECC byte to retrieve
1873 * @nbytes: number of ECC bytes to retrieve
1875 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1877 * Returns zero on success, a negative error code otherwise.
1879 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1880 const u8 *oobbuf, int start, int nbytes)
1882 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1885 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1888 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1889 * @mtd: mtd info structure
1890 * @eccbuf: source buffer to get ECC bytes from
1891 * @oobbuf: OOB buffer
1892 * @start: first ECC byte to set
1893 * @nbytes: number of ECC bytes to set
1895 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1897 * Returns zero on success, a negative error code otherwise.
1899 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1900 u8 *oobbuf, int start, int nbytes)
1902 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1905 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1908 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1909 * @mtd: mtd info structure
1910 * @databuf: destination buffer to store ECC bytes
1911 * @oobbuf: OOB buffer
1912 * @start: first ECC byte to retrieve
1913 * @nbytes: number of ECC bytes to retrieve
1915 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1917 * Returns zero on success, a negative error code otherwise.
1919 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1920 const u8 *oobbuf, int start, int nbytes)
1922 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1923 mtd_ooblayout_free);
1925 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1928 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1929 * @mtd: mtd info structure
1930 * @databuf: source buffer to get data bytes from
1931 * @oobbuf: OOB buffer
1932 * @start: first ECC byte to set
1933 * @nbytes: number of ECC bytes to set
1935 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
1937 * Returns zero on success, a negative error code otherwise.
1939 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1940 u8 *oobbuf, int start, int nbytes)
1942 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1943 mtd_ooblayout_free);
1945 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1948 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1949 * @mtd: mtd info structure
1951 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1953 * Returns zero on success, a negative error code otherwise.
1955 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1957 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1959 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1962 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1963 * @mtd: mtd info structure
1965 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1967 * Returns zero on success, a negative error code otherwise.
1969 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1971 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1973 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1976 * Method to access the protection register area, present in some flash
1977 * devices. The user data is one time programmable but the factory data is read
1980 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1981 struct otp_info *buf)
1983 struct mtd_info *master = mtd_get_master(mtd);
1985 if (!master->_get_fact_prot_info)
1989 return master->_get_fact_prot_info(master, len, retlen, buf);
1991 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1993 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1994 size_t *retlen, u_char *buf)
1996 struct mtd_info *master = mtd_get_master(mtd);
1999 if (!master->_read_fact_prot_reg)
2003 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
2005 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
2007 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2008 struct otp_info *buf)
2010 struct mtd_info *master = mtd_get_master(mtd);
2012 if (!master->_get_user_prot_info)
2016 return master->_get_user_prot_info(master, len, retlen, buf);
2018 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
2020 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2021 size_t *retlen, u_char *buf)
2023 struct mtd_info *master = mtd_get_master(mtd);
2026 if (!master->_read_user_prot_reg)
2030 return master->_read_user_prot_reg(master, from, len, retlen, buf);
2032 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
2034 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
2035 size_t *retlen, const u_char *buf)
2037 struct mtd_info *master = mtd_get_master(mtd);
2041 if (!master->_write_user_prot_reg)
2045 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
2050 * If no data could be written at all, we are out of memory and
2051 * must return -ENOSPC.
2053 return (*retlen) ? 0 : -ENOSPC;
2055 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
2057 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2059 struct mtd_info *master = mtd_get_master(mtd);
2061 if (!master->_lock_user_prot_reg)
2065 return master->_lock_user_prot_reg(master, from, len);
2067 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
2069 int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2071 struct mtd_info *master = mtd_get_master(mtd);
2073 if (!master->_erase_user_prot_reg)
2077 return master->_erase_user_prot_reg(master, from, len);
2079 EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
2081 /* Chip-supported device locking */
2082 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2084 struct mtd_info *master = mtd_get_master(mtd);
2088 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2093 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2094 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2095 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2098 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
2100 EXPORT_SYMBOL_GPL(mtd_lock);
2102 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2104 struct mtd_info *master = mtd_get_master(mtd);
2106 if (!master->_unlock)
2108 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2113 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2114 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2115 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2118 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
2120 EXPORT_SYMBOL_GPL(mtd_unlock);
2122 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2124 struct mtd_info *master = mtd_get_master(mtd);
2126 if (!master->_is_locked)
2128 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2133 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2134 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2135 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2138 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
2140 EXPORT_SYMBOL_GPL(mtd_is_locked);
2142 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2144 struct mtd_info *master = mtd_get_master(mtd);
2146 if (ofs < 0 || ofs >= mtd->size)
2148 if (!master->_block_isreserved)
2151 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2152 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2154 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2156 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2158 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2160 struct mtd_info *master = mtd_get_master(mtd);
2162 if (ofs < 0 || ofs >= mtd->size)
2164 if (!master->_block_isbad)
2167 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2168 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2170 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2172 EXPORT_SYMBOL_GPL(mtd_block_isbad);
2174 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2176 struct mtd_info *master = mtd_get_master(mtd);
2179 if (!master->_block_markbad)
2181 if (ofs < 0 || ofs >= mtd->size)
2183 if (!(mtd->flags & MTD_WRITEABLE))
2186 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2187 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2189 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2193 while (mtd->parent) {
2194 mtd->ecc_stats.badblocks++;
2200 EXPORT_SYMBOL_GPL(mtd_block_markbad);
2203 * default_mtd_writev - the default writev method
2204 * @mtd: mtd device description object pointer
2205 * @vecs: the vectors to write
2206 * @count: count of vectors in @vecs
2207 * @to: the MTD device offset to write to
2208 * @retlen: on exit contains the count of bytes written to the MTD device.
2210 * This function returns zero in case of success and a negative error code in
2213 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2214 unsigned long count, loff_t to, size_t *retlen)
2217 size_t totlen = 0, thislen;
2220 for (i = 0; i < count; i++) {
2221 if (!vecs[i].iov_len)
2223 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2226 if (ret || thislen != vecs[i].iov_len)
2228 to += vecs[i].iov_len;
2235 * mtd_writev - the vector-based MTD write method
2236 * @mtd: mtd device description object pointer
2237 * @vecs: the vectors to write
2238 * @count: count of vectors in @vecs
2239 * @to: the MTD device offset to write to
2240 * @retlen: on exit contains the count of bytes written to the MTD device.
2242 * This function returns zero in case of success and a negative error code in
2245 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2246 unsigned long count, loff_t to, size_t *retlen)
2248 struct mtd_info *master = mtd_get_master(mtd);
2251 if (!(mtd->flags & MTD_WRITEABLE))
2254 if (!master->_writev)
2255 return default_mtd_writev(mtd, vecs, count, to, retlen);
2257 return master->_writev(master, vecs, count,
2258 mtd_get_master_ofs(mtd, to), retlen);
2260 EXPORT_SYMBOL_GPL(mtd_writev);
2263 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2264 * @mtd: mtd device description object pointer
2265 * @size: a pointer to the ideal or maximum size of the allocation, points
2266 * to the actual allocation size on success.
2268 * This routine attempts to allocate a contiguous kernel buffer up to
2269 * the specified size, backing off the size of the request exponentially
2270 * until the request succeeds or until the allocation size falls below
2271 * the system page size. This attempts to make sure it does not adversely
2272 * impact system performance, so when allocating more than one page, we
2273 * ask the memory allocator to avoid re-trying, swapping, writing back
2274 * or performing I/O.
2276 * Note, this function also makes sure that the allocated buffer is aligned to
2277 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2279 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2280 * to handle smaller (i.e. degraded) buffer allocations under low- or
2281 * fragmented-memory situations where such reduced allocations, from a
2282 * requested ideal, are allowed.
2284 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2286 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2288 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2289 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2292 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2294 while (*size > min_alloc) {
2295 kbuf = kmalloc(*size, flags);
2300 *size = ALIGN(*size, mtd->writesize);
2304 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2305 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2307 return kmalloc(*size, GFP_KERNEL);
2309 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2311 #ifdef CONFIG_PROC_FS
2313 /*====================================================================*/
2314 /* Support for /proc/mtd */
2316 static int mtd_proc_show(struct seq_file *m, void *v)
2318 struct mtd_info *mtd;
2320 seq_puts(m, "dev: size erasesize name\n");
2321 mutex_lock(&mtd_table_mutex);
2322 mtd_for_each_device(mtd) {
2323 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2324 mtd->index, (unsigned long long)mtd->size,
2325 mtd->erasesize, mtd->name);
2327 mutex_unlock(&mtd_table_mutex);
2330 #endif /* CONFIG_PROC_FS */
2332 /*====================================================================*/
2335 static struct backing_dev_info * __init mtd_bdi_init(const char *name)
2337 struct backing_dev_info *bdi;
2340 bdi = bdi_alloc(NUMA_NO_NODE);
2342 return ERR_PTR(-ENOMEM);
2347 * We put '-0' suffix to the name to get the same name format as we
2348 * used to get. Since this is called only once, we get a unique name.
2350 ret = bdi_register(bdi, "%.28s-0", name);
2354 return ret ? ERR_PTR(ret) : bdi;
2357 static struct proc_dir_entry *proc_mtd;
2359 static int __init init_mtd(void)
2363 ret = class_register(&mtd_class);
2367 mtd_bdi = mtd_bdi_init("mtd");
2368 if (IS_ERR(mtd_bdi)) {
2369 ret = PTR_ERR(mtd_bdi);
2373 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2375 ret = init_mtdchar();
2379 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2380 debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd,
2381 &mtd_expert_analysis_mode);
2387 remove_proc_entry("mtd", NULL);
2390 class_unregister(&mtd_class);
2392 pr_err("Error registering mtd class or bdi: %d\n", ret);
2396 static void __exit cleanup_mtd(void)
2398 debugfs_remove_recursive(dfs_dir_mtd);
2401 remove_proc_entry("mtd", NULL);
2402 class_unregister(&mtd_class);
2403 bdi_unregister(mtd_bdi);
2405 idr_destroy(&mtd_idr);
2408 module_init(init_mtd);
2409 module_exit(cleanup_mtd);
2411 MODULE_LICENSE("GPL");
2412 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2413 MODULE_DESCRIPTION("Core MTD registration and access routines");