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 int mtd_partid_debug_show(struct seq_file *s, void *p)
341 struct mtd_info *mtd = s->private;
343 seq_printf(s, "%s\n", mtd->dbg.partid);
348 DEFINE_SHOW_ATTRIBUTE(mtd_partid_debug);
350 static int mtd_partname_debug_show(struct seq_file *s, void *p)
352 struct mtd_info *mtd = s->private;
354 seq_printf(s, "%s\n", mtd->dbg.partname);
359 DEFINE_SHOW_ATTRIBUTE(mtd_partname_debug);
361 static struct dentry *dfs_dir_mtd;
363 static void mtd_debugfs_populate(struct mtd_info *mtd)
365 struct mtd_info *master = mtd_get_master(mtd);
366 struct device *dev = &mtd->dev;
369 if (IS_ERR_OR_NULL(dfs_dir_mtd))
372 root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
373 mtd->dbg.dfs_dir = root;
375 if (master->dbg.partid)
376 debugfs_create_file("partid", 0400, root, master,
377 &mtd_partid_debug_fops);
379 if (master->dbg.partname)
380 debugfs_create_file("partname", 0400, root, master,
381 &mtd_partname_debug_fops);
385 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
389 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
390 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
392 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
395 return NOMMU_MAP_COPY;
398 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
401 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
404 struct mtd_info *mtd;
406 mtd = container_of(n, struct mtd_info, reboot_notifier);
413 * mtd_wunit_to_pairing_info - get pairing information of a wunit
414 * @mtd: pointer to new MTD device info structure
415 * @wunit: write unit we are interested in
416 * @info: returned pairing information
418 * Retrieve pairing information associated to the wunit.
419 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
420 * paired together, and where programming a page may influence the page it is
422 * The notion of page is replaced by the term wunit (write-unit) to stay
423 * consistent with the ->writesize field.
425 * The @wunit argument can be extracted from an absolute offset using
426 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
429 * From the pairing info the MTD user can find all the wunits paired with
430 * @wunit using the following loop:
432 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
434 * mtd_pairing_info_to_wunit(mtd, &info);
438 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
439 struct mtd_pairing_info *info)
441 struct mtd_info *master = mtd_get_master(mtd);
442 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
444 if (wunit < 0 || wunit >= npairs)
447 if (master->pairing && master->pairing->get_info)
448 return master->pairing->get_info(master, wunit, info);
455 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
458 * mtd_pairing_info_to_wunit - get wunit from pairing information
459 * @mtd: pointer to new MTD device info structure
460 * @info: pairing information struct
462 * Returns a positive number representing the wunit associated to the info
463 * struct, or a negative error code.
465 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
466 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
469 * It can also be used to only program the first page of each pair (i.e.
470 * page attached to group 0), which allows one to use an MLC NAND in
471 * software-emulated SLC mode:
474 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
475 * for (info.pair = 0; info.pair < npairs; info.pair++) {
476 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
477 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
478 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
481 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
482 const struct mtd_pairing_info *info)
484 struct mtd_info *master = mtd_get_master(mtd);
485 int ngroups = mtd_pairing_groups(master);
486 int npairs = mtd_wunit_per_eb(master) / ngroups;
488 if (!info || info->pair < 0 || info->pair >= npairs ||
489 info->group < 0 || info->group >= ngroups)
492 if (master->pairing && master->pairing->get_wunit)
493 return mtd->pairing->get_wunit(master, info);
497 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
500 * mtd_pairing_groups - get the number of pairing groups
501 * @mtd: pointer to new MTD device info structure
503 * Returns the number of pairing groups.
505 * This number is usually equal to the number of bits exposed by a single
506 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
507 * to iterate over all pages of a given pair.
509 int mtd_pairing_groups(struct mtd_info *mtd)
511 struct mtd_info *master = mtd_get_master(mtd);
513 if (!master->pairing || !master->pairing->ngroups)
516 return master->pairing->ngroups;
518 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
520 static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
521 void *val, size_t bytes)
523 struct mtd_info *mtd = priv;
527 err = mtd_read(mtd, offset, bytes, &retlen, val);
528 if (err && err != -EUCLEAN)
531 return retlen == bytes ? 0 : -EIO;
534 static int mtd_nvmem_add(struct mtd_info *mtd)
536 struct device_node *node = mtd_get_of_node(mtd);
537 struct nvmem_config config = {};
540 config.dev = &mtd->dev;
541 config.name = dev_name(&mtd->dev);
542 config.owner = THIS_MODULE;
543 config.reg_read = mtd_nvmem_reg_read;
544 config.size = mtd->size;
545 config.word_size = 1;
547 config.read_only = true;
548 config.root_only = true;
549 config.ignore_wp = true;
550 config.no_of_node = !of_device_is_compatible(node, "nvmem-cells");
553 mtd->nvmem = nvmem_register(&config);
554 if (IS_ERR(mtd->nvmem)) {
555 /* Just ignore if there is no NVMEM support in the kernel */
556 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
559 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
560 return PTR_ERR(mtd->nvmem);
568 * add_mtd_device - register an MTD device
569 * @mtd: pointer to new MTD device info structure
571 * Add a device to the list of MTD devices present in the system, and
572 * notify each currently active MTD 'user' of its arrival. Returns
573 * zero on success or non-zero on failure.
576 int add_mtd_device(struct mtd_info *mtd)
578 struct mtd_info *master = mtd_get_master(mtd);
579 struct mtd_notifier *not;
583 * May occur, for instance, on buggy drivers which call
584 * mtd_device_parse_register() multiple times on the same master MTD,
585 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
587 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
590 BUG_ON(mtd->writesize == 0);
593 * MTD drivers should implement ->_{write,read}() or
594 * ->_{write,read}_oob(), but not both.
596 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
597 (mtd->_read && mtd->_read_oob)))
600 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
601 !(mtd->flags & MTD_NO_ERASE)))
605 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
606 * master is an MLC NAND and has a proper pairing scheme defined.
607 * We also reject masters that implement ->_writev() for now, because
608 * NAND controller drivers don't implement this hook, and adding the
609 * SLC -> MLC address/length conversion to this path is useless if we
612 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
613 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
614 !master->pairing || master->_writev))
617 mutex_lock(&mtd_table_mutex);
619 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
628 /* default value if not set by driver */
629 if (mtd->bitflip_threshold == 0)
630 mtd->bitflip_threshold = mtd->ecc_strength;
632 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
633 int ngroups = mtd_pairing_groups(master);
635 mtd->erasesize /= ngroups;
636 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
640 if (is_power_of_2(mtd->erasesize))
641 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
643 mtd->erasesize_shift = 0;
645 if (is_power_of_2(mtd->writesize))
646 mtd->writesize_shift = ffs(mtd->writesize) - 1;
648 mtd->writesize_shift = 0;
650 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
651 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
653 /* Some chips always power up locked. Unlock them now */
654 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
655 error = mtd_unlock(mtd, 0, mtd->size);
656 if (error && error != -EOPNOTSUPP)
658 "%s: unlock failed, writes may not work\n",
660 /* Ignore unlock failures? */
664 /* Caller should have set dev.parent to match the
665 * physical device, if appropriate.
667 mtd->dev.type = &mtd_devtype;
668 mtd->dev.class = &mtd_class;
669 mtd->dev.devt = MTD_DEVT(i);
670 dev_set_name(&mtd->dev, "mtd%d", i);
671 dev_set_drvdata(&mtd->dev, mtd);
672 of_node_get(mtd_get_of_node(mtd));
673 error = device_register(&mtd->dev);
677 /* Add the nvmem provider */
678 error = mtd_nvmem_add(mtd);
682 mtd_debugfs_populate(mtd);
684 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
687 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
688 /* No need to get a refcount on the module containing
689 the notifier, since we hold the mtd_table_mutex */
690 list_for_each_entry(not, &mtd_notifiers, list)
693 mutex_unlock(&mtd_table_mutex);
694 /* We _know_ we aren't being removed, because
695 our caller is still holding us here. So none
696 of this try_ nonsense, and no bitching about it
698 __module_get(THIS_MODULE);
702 device_unregister(&mtd->dev);
704 of_node_put(mtd_get_of_node(mtd));
705 idr_remove(&mtd_idr, i);
707 mutex_unlock(&mtd_table_mutex);
712 * del_mtd_device - unregister an MTD device
713 * @mtd: pointer to MTD device info structure
715 * Remove a device from the list of MTD devices present in the system,
716 * and notify each currently active MTD 'user' of its departure.
717 * Returns zero on success or 1 on failure, which currently will happen
718 * if the requested device does not appear to be present in the list.
721 int del_mtd_device(struct mtd_info *mtd)
724 struct mtd_notifier *not;
726 mutex_lock(&mtd_table_mutex);
728 if (idr_find(&mtd_idr, mtd->index) != mtd) {
733 /* No need to get a refcount on the module containing
734 the notifier, since we hold the mtd_table_mutex */
735 list_for_each_entry(not, &mtd_notifiers, list)
739 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
740 mtd->index, mtd->name, mtd->usecount);
743 debugfs_remove_recursive(mtd->dbg.dfs_dir);
745 /* Try to remove the NVMEM provider */
747 nvmem_unregister(mtd->nvmem);
749 device_unregister(&mtd->dev);
751 /* Clear dev so mtd can be safely re-registered later if desired */
752 memset(&mtd->dev, 0, sizeof(mtd->dev));
754 idr_remove(&mtd_idr, mtd->index);
755 of_node_put(mtd_get_of_node(mtd));
757 module_put(THIS_MODULE);
762 mutex_unlock(&mtd_table_mutex);
767 * Set a few defaults based on the parent devices, if not provided by the
770 static void mtd_set_dev_defaults(struct mtd_info *mtd)
772 if (mtd->dev.parent) {
773 if (!mtd->owner && mtd->dev.parent->driver)
774 mtd->owner = mtd->dev.parent->driver->owner;
776 mtd->name = dev_name(mtd->dev.parent);
778 pr_debug("mtd device won't show a device symlink in sysfs\n");
781 INIT_LIST_HEAD(&mtd->partitions);
782 mutex_init(&mtd->master.partitions_lock);
783 mutex_init(&mtd->master.chrdev_lock);
786 static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
788 struct otp_info *info;
794 info = kmalloc(PAGE_SIZE, GFP_KERNEL);
799 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info);
801 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info);
805 for (i = 0; i < retlen / sizeof(*info); i++)
806 size += info[i].length;
814 /* ENODATA means there is no OTP region. */
815 return ret == -ENODATA ? 0 : ret;
818 static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
819 const char *compatible,
821 nvmem_reg_read_t reg_read)
823 struct nvmem_device *nvmem = NULL;
824 struct nvmem_config config = {};
825 struct device_node *np;
827 /* DT binding is optional */
828 np = of_get_compatible_child(mtd->dev.of_node, compatible);
830 /* OTP nvmem will be registered on the physical device */
831 config.dev = mtd->dev.parent;
832 config.name = kasprintf(GFP_KERNEL, "%s-%s", dev_name(&mtd->dev), compatible);
833 config.id = NVMEM_DEVID_NONE;
834 config.owner = THIS_MODULE;
835 config.type = NVMEM_TYPE_OTP;
836 config.root_only = true;
837 config.ignore_wp = true;
838 config.reg_read = reg_read;
843 nvmem = nvmem_register(&config);
844 /* Just ignore if there is no NVMEM support in the kernel */
845 if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP)
854 static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
855 void *val, size_t bytes)
857 struct mtd_info *mtd = priv;
861 ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val);
865 return retlen == bytes ? 0 : -EIO;
868 static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
869 void *val, size_t bytes)
871 struct mtd_info *mtd = priv;
875 ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val);
879 return retlen == bytes ? 0 : -EIO;
882 static int mtd_otp_nvmem_add(struct mtd_info *mtd)
884 struct nvmem_device *nvmem;
888 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
889 size = mtd_otp_size(mtd, true);
894 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
895 mtd_nvmem_user_otp_reg_read);
897 dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
898 return PTR_ERR(nvmem);
900 mtd->otp_user_nvmem = nvmem;
904 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
905 size = mtd_otp_size(mtd, false);
912 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
913 mtd_nvmem_fact_otp_reg_read);
915 dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
916 err = PTR_ERR(nvmem);
919 mtd->otp_factory_nvmem = nvmem;
926 if (mtd->otp_user_nvmem)
927 nvmem_unregister(mtd->otp_user_nvmem);
932 * mtd_device_parse_register - parse partitions and register an MTD device.
934 * @mtd: the MTD device to register
935 * @types: the list of MTD partition probes to try, see
936 * 'parse_mtd_partitions()' for more information
937 * @parser_data: MTD partition parser-specific data
938 * @parts: fallback partition information to register, if parsing fails;
939 * only valid if %nr_parts > %0
940 * @nr_parts: the number of partitions in parts, if zero then the full
941 * MTD device is registered if no partition info is found
943 * This function aggregates MTD partitions parsing (done by
944 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
945 * basically follows the most common pattern found in many MTD drivers:
947 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
949 * * Then It tries to probe partitions on MTD device @mtd using parsers
950 * specified in @types (if @types is %NULL, then the default list of parsers
951 * is used, see 'parse_mtd_partitions()' for more information). If none are
952 * found this functions tries to fallback to information specified in
954 * * If no partitions were found this function just registers the MTD device
957 * Returns zero in case of success and a negative error code in case of failure.
959 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
960 struct mtd_part_parser_data *parser_data,
961 const struct mtd_partition *parts,
966 mtd_set_dev_defaults(mtd);
968 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
969 ret = add_mtd_device(mtd);
974 /* Prefer parsed partitions over driver-provided fallback */
975 ret = parse_mtd_partitions(mtd, types, parser_data);
976 if (ret == -EPROBE_DEFER)
982 ret = add_mtd_partitions(mtd, parts, nr_parts);
983 else if (!device_is_registered(&mtd->dev))
984 ret = add_mtd_device(mtd);
992 * FIXME: some drivers unfortunately call this function more than once.
993 * So we have to check if we've already assigned the reboot notifier.
995 * Generally, we can make multiple calls work for most cases, but it
996 * does cause problems with parse_mtd_partitions() above (e.g.,
997 * cmdlineparts will register partitions more than once).
999 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
1000 "MTD already registered\n");
1001 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
1002 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
1003 register_reboot_notifier(&mtd->reboot_notifier);
1006 ret = mtd_otp_nvmem_add(mtd);
1009 if (ret && device_is_registered(&mtd->dev))
1010 del_mtd_device(mtd);
1014 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
1017 * mtd_device_unregister - unregister an existing MTD device.
1019 * @master: the MTD device to unregister. This will unregister both the master
1020 * and any partitions if registered.
1022 int mtd_device_unregister(struct mtd_info *master)
1026 if (master->_reboot) {
1027 unregister_reboot_notifier(&master->reboot_notifier);
1028 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
1031 if (master->otp_user_nvmem)
1032 nvmem_unregister(master->otp_user_nvmem);
1034 if (master->otp_factory_nvmem)
1035 nvmem_unregister(master->otp_factory_nvmem);
1037 err = del_mtd_partitions(master);
1041 if (!device_is_registered(&master->dev))
1044 return del_mtd_device(master);
1046 EXPORT_SYMBOL_GPL(mtd_device_unregister);
1049 * register_mtd_user - register a 'user' of MTD devices.
1050 * @new: pointer to notifier info structure
1052 * Registers a pair of callbacks function to be called upon addition
1053 * or removal of MTD devices. Causes the 'add' callback to be immediately
1054 * invoked for each MTD device currently present in the system.
1056 void register_mtd_user (struct mtd_notifier *new)
1058 struct mtd_info *mtd;
1060 mutex_lock(&mtd_table_mutex);
1062 list_add(&new->list, &mtd_notifiers);
1064 __module_get(THIS_MODULE);
1066 mtd_for_each_device(mtd)
1069 mutex_unlock(&mtd_table_mutex);
1071 EXPORT_SYMBOL_GPL(register_mtd_user);
1074 * unregister_mtd_user - unregister a 'user' of MTD devices.
1075 * @old: pointer to notifier info structure
1077 * Removes a callback function pair from the list of 'users' to be
1078 * notified upon addition or removal of MTD devices. Causes the
1079 * 'remove' callback to be immediately invoked for each MTD device
1080 * currently present in the system.
1082 int unregister_mtd_user (struct mtd_notifier *old)
1084 struct mtd_info *mtd;
1086 mutex_lock(&mtd_table_mutex);
1088 module_put(THIS_MODULE);
1090 mtd_for_each_device(mtd)
1093 list_del(&old->list);
1094 mutex_unlock(&mtd_table_mutex);
1097 EXPORT_SYMBOL_GPL(unregister_mtd_user);
1100 * get_mtd_device - obtain a validated handle for an MTD device
1101 * @mtd: last known address of the required MTD device
1102 * @num: internal device number of the required MTD device
1104 * Given a number and NULL address, return the num'th entry in the device
1105 * table, if any. Given an address and num == -1, search the device table
1106 * for a device with that address and return if it's still present. Given
1107 * both, return the num'th driver only if its address matches. Return
1108 * error code if not.
1110 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
1112 struct mtd_info *ret = NULL, *other;
1115 mutex_lock(&mtd_table_mutex);
1118 mtd_for_each_device(other) {
1124 } else if (num >= 0) {
1125 ret = idr_find(&mtd_idr, num);
1126 if (mtd && mtd != ret)
1135 err = __get_mtd_device(ret);
1139 mutex_unlock(&mtd_table_mutex);
1142 EXPORT_SYMBOL_GPL(get_mtd_device);
1145 int __get_mtd_device(struct mtd_info *mtd)
1147 struct mtd_info *master = mtd_get_master(mtd);
1150 if (!try_module_get(master->owner))
1153 if (master->_get_device) {
1154 err = master->_get_device(mtd);
1157 module_put(master->owner);
1164 while (mtd->parent) {
1171 EXPORT_SYMBOL_GPL(__get_mtd_device);
1174 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1176 * @name: MTD device name to open
1178 * This function returns MTD device description structure in case of
1179 * success and an error code in case of failure.
1181 struct mtd_info *get_mtd_device_nm(const char *name)
1184 struct mtd_info *mtd = NULL, *other;
1186 mutex_lock(&mtd_table_mutex);
1188 mtd_for_each_device(other) {
1189 if (!strcmp(name, other->name)) {
1198 err = __get_mtd_device(mtd);
1202 mutex_unlock(&mtd_table_mutex);
1206 mutex_unlock(&mtd_table_mutex);
1207 return ERR_PTR(err);
1209 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1211 void put_mtd_device(struct mtd_info *mtd)
1213 mutex_lock(&mtd_table_mutex);
1214 __put_mtd_device(mtd);
1215 mutex_unlock(&mtd_table_mutex);
1218 EXPORT_SYMBOL_GPL(put_mtd_device);
1220 void __put_mtd_device(struct mtd_info *mtd)
1222 struct mtd_info *master = mtd_get_master(mtd);
1224 while (mtd->parent) {
1226 BUG_ON(mtd->usecount < 0);
1232 if (master->_put_device)
1233 master->_put_device(master);
1235 module_put(master->owner);
1237 EXPORT_SYMBOL_GPL(__put_mtd_device);
1240 * Erase is an synchronous operation. Device drivers are epected to return a
1241 * negative error code if the operation failed and update instr->fail_addr
1242 * to point the portion that was not properly erased.
1244 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1246 struct mtd_info *master = mtd_get_master(mtd);
1247 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1248 struct erase_info adjinstr;
1251 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1254 if (!mtd->erasesize || !master->_erase)
1257 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1259 if (!(mtd->flags & MTD_WRITEABLE))
1265 ledtrig_mtd_activity();
1267 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1268 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1270 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1271 master->erasesize) -
1275 adjinstr.addr += mst_ofs;
1277 ret = master->_erase(master, &adjinstr);
1279 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1280 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1281 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1282 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1284 instr->fail_addr *= mtd->erasesize;
1290 EXPORT_SYMBOL_GPL(mtd_erase);
1293 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1295 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1296 void **virt, resource_size_t *phys)
1298 struct mtd_info *master = mtd_get_master(mtd);
1304 if (!master->_point)
1306 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1311 from = mtd_get_master_ofs(mtd, from);
1312 return master->_point(master, from, len, retlen, virt, phys);
1314 EXPORT_SYMBOL_GPL(mtd_point);
1316 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1317 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1319 struct mtd_info *master = mtd_get_master(mtd);
1321 if (!master->_unpoint)
1323 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1327 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1329 EXPORT_SYMBOL_GPL(mtd_unpoint);
1332 * Allow NOMMU mmap() to directly map the device (if not NULL)
1333 * - return the address to which the offset maps
1334 * - return -ENOSYS to indicate refusal to do the mapping
1336 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1337 unsigned long offset, unsigned long flags)
1343 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1346 if (retlen != len) {
1347 mtd_unpoint(mtd, offset, retlen);
1350 return (unsigned long)virt;
1352 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1354 static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1355 const struct mtd_ecc_stats *old_stats)
1357 struct mtd_ecc_stats diff;
1362 diff = master->ecc_stats;
1363 diff.failed -= old_stats->failed;
1364 diff.corrected -= old_stats->corrected;
1366 while (mtd->parent) {
1367 mtd->ecc_stats.failed += diff.failed;
1368 mtd->ecc_stats.corrected += diff.corrected;
1373 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1376 struct mtd_oob_ops ops = {
1382 ret = mtd_read_oob(mtd, from, &ops);
1383 *retlen = ops.retlen;
1387 EXPORT_SYMBOL_GPL(mtd_read);
1389 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1392 struct mtd_oob_ops ops = {
1394 .datbuf = (u8 *)buf,
1398 ret = mtd_write_oob(mtd, to, &ops);
1399 *retlen = ops.retlen;
1403 EXPORT_SYMBOL_GPL(mtd_write);
1406 * In blackbox flight recorder like scenarios we want to make successful writes
1407 * in interrupt context. panic_write() is only intended to be called when its
1408 * known the kernel is about to panic and we need the write to succeed. Since
1409 * the kernel is not going to be running for much longer, this function can
1410 * break locks and delay to ensure the write succeeds (but not sleep).
1412 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1415 struct mtd_info *master = mtd_get_master(mtd);
1418 if (!master->_panic_write)
1420 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1422 if (!(mtd->flags & MTD_WRITEABLE))
1426 if (!master->oops_panic_write)
1427 master->oops_panic_write = true;
1429 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1432 EXPORT_SYMBOL_GPL(mtd_panic_write);
1434 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1435 struct mtd_oob_ops *ops)
1438 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1439 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1448 if (offs < 0 || offs + ops->len > mtd->size)
1454 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1457 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1458 mtd_div_by_ws(offs, mtd)) *
1459 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1460 if (ops->ooblen > maxooblen)
1467 static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1468 struct mtd_oob_ops *ops)
1470 struct mtd_info *master = mtd_get_master(mtd);
1473 from = mtd_get_master_ofs(mtd, from);
1474 if (master->_read_oob)
1475 ret = master->_read_oob(master, from, ops);
1477 ret = master->_read(master, from, ops->len, &ops->retlen,
1483 static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1484 struct mtd_oob_ops *ops)
1486 struct mtd_info *master = mtd_get_master(mtd);
1489 to = mtd_get_master_ofs(mtd, to);
1490 if (master->_write_oob)
1491 ret = master->_write_oob(master, to, ops);
1493 ret = master->_write(master, to, ops->len, &ops->retlen,
1499 static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1500 struct mtd_oob_ops *ops)
1502 struct mtd_info *master = mtd_get_master(mtd);
1503 int ngroups = mtd_pairing_groups(master);
1504 int npairs = mtd_wunit_per_eb(master) / ngroups;
1505 struct mtd_oob_ops adjops = *ops;
1506 unsigned int wunit, oobavail;
1507 struct mtd_pairing_info info;
1508 int max_bitflips = 0;
1512 ebofs = mtd_mod_by_eb(start, mtd);
1513 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1515 info.pair = mtd_div_by_ws(ebofs, mtd);
1516 pageofs = mtd_mod_by_ws(ebofs, mtd);
1517 oobavail = mtd_oobavail(mtd, ops);
1519 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1522 if (info.pair >= npairs) {
1524 base += master->erasesize;
1527 wunit = mtd_pairing_info_to_wunit(master, &info);
1528 pos = mtd_wunit_to_offset(mtd, base, wunit);
1530 adjops.len = ops->len - ops->retlen;
1531 if (adjops.len > mtd->writesize - pageofs)
1532 adjops.len = mtd->writesize - pageofs;
1534 adjops.ooblen = ops->ooblen - ops->oobretlen;
1535 if (adjops.ooblen > oobavail - adjops.ooboffs)
1536 adjops.ooblen = oobavail - adjops.ooboffs;
1539 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1541 max_bitflips = max(max_bitflips, ret);
1543 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1549 max_bitflips = max(max_bitflips, ret);
1550 ops->retlen += adjops.retlen;
1551 ops->oobretlen += adjops.oobretlen;
1552 adjops.datbuf += adjops.retlen;
1553 adjops.oobbuf += adjops.oobretlen;
1559 return max_bitflips;
1562 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1564 struct mtd_info *master = mtd_get_master(mtd);
1565 struct mtd_ecc_stats old_stats = master->ecc_stats;
1568 ops->retlen = ops->oobretlen = 0;
1570 ret_code = mtd_check_oob_ops(mtd, from, ops);
1574 ledtrig_mtd_activity();
1576 /* Check the validity of a potential fallback on mtd->_read */
1577 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1580 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1581 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1583 ret_code = mtd_read_oob_std(mtd, from, ops);
1585 mtd_update_ecc_stats(mtd, master, &old_stats);
1588 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1589 * similar to mtd->_read(), returning a non-negative integer
1590 * representing max bitflips. In other cases, mtd->_read_oob() may
1591 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1593 if (unlikely(ret_code < 0))
1595 if (mtd->ecc_strength == 0)
1596 return 0; /* device lacks ecc */
1597 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1599 EXPORT_SYMBOL_GPL(mtd_read_oob);
1601 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1602 struct mtd_oob_ops *ops)
1604 struct mtd_info *master = mtd_get_master(mtd);
1607 ops->retlen = ops->oobretlen = 0;
1609 if (!(mtd->flags & MTD_WRITEABLE))
1612 ret = mtd_check_oob_ops(mtd, to, ops);
1616 ledtrig_mtd_activity();
1618 /* Check the validity of a potential fallback on mtd->_write */
1619 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1622 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1623 return mtd_io_emulated_slc(mtd, to, false, ops);
1625 return mtd_write_oob_std(mtd, to, ops);
1627 EXPORT_SYMBOL_GPL(mtd_write_oob);
1630 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1631 * @mtd: MTD device structure
1632 * @section: ECC section. Depending on the layout you may have all the ECC
1633 * bytes stored in a single contiguous section, or one section
1634 * per ECC chunk (and sometime several sections for a single ECC
1636 * @oobecc: OOB region struct filled with the appropriate ECC position
1639 * This function returns ECC section information in the OOB area. If you want
1640 * to get all the ECC bytes information, then you should call
1641 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1643 * Returns zero on success, a negative error code otherwise.
1645 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1646 struct mtd_oob_region *oobecc)
1648 struct mtd_info *master = mtd_get_master(mtd);
1650 memset(oobecc, 0, sizeof(*oobecc));
1652 if (!master || section < 0)
1655 if (!master->ooblayout || !master->ooblayout->ecc)
1658 return master->ooblayout->ecc(master, section, oobecc);
1660 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1663 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1665 * @mtd: MTD device structure
1666 * @section: Free section you are interested in. Depending on the layout
1667 * you may have all the free bytes stored in a single contiguous
1668 * section, or one section per ECC chunk plus an extra section
1669 * for the remaining bytes (or other funky layout).
1670 * @oobfree: OOB region struct filled with the appropriate free position
1673 * This function returns free bytes position in the OOB area. If you want
1674 * to get all the free bytes information, then you should call
1675 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1677 * Returns zero on success, a negative error code otherwise.
1679 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1680 struct mtd_oob_region *oobfree)
1682 struct mtd_info *master = mtd_get_master(mtd);
1684 memset(oobfree, 0, sizeof(*oobfree));
1686 if (!master || section < 0)
1689 if (!master->ooblayout || !master->ooblayout->free)
1692 return master->ooblayout->free(master, section, oobfree);
1694 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1697 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1698 * @mtd: mtd info structure
1699 * @byte: the byte we are searching for
1700 * @sectionp: pointer where the section id will be stored
1701 * @oobregion: used to retrieve the ECC position
1702 * @iter: iterator function. Should be either mtd_ooblayout_free or
1703 * mtd_ooblayout_ecc depending on the region type you're searching for
1705 * This function returns the section id and oobregion information of a
1706 * specific byte. For example, say you want to know where the 4th ECC byte is
1707 * stored, you'll use:
1709 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1711 * Returns zero on success, a negative error code otherwise.
1713 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1714 int *sectionp, struct mtd_oob_region *oobregion,
1715 int (*iter)(struct mtd_info *,
1717 struct mtd_oob_region *oobregion))
1719 int pos = 0, ret, section = 0;
1721 memset(oobregion, 0, sizeof(*oobregion));
1724 ret = iter(mtd, section, oobregion);
1728 if (pos + oobregion->length > byte)
1731 pos += oobregion->length;
1736 * Adjust region info to make it start at the beginning at the
1739 oobregion->offset += byte - pos;
1740 oobregion->length -= byte - pos;
1741 *sectionp = section;
1747 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1749 * @mtd: mtd info structure
1750 * @eccbyte: the byte we are searching for
1751 * @section: pointer where the section id will be stored
1752 * @oobregion: OOB region information
1754 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1757 * Returns zero on success, a negative error code otherwise.
1759 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1761 struct mtd_oob_region *oobregion)
1763 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1766 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1769 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1770 * @mtd: mtd info structure
1771 * @buf: destination buffer to store OOB bytes
1772 * @oobbuf: OOB buffer
1773 * @start: first byte to retrieve
1774 * @nbytes: number of bytes to retrieve
1775 * @iter: section iterator
1777 * Extract bytes attached to a specific category (ECC or free)
1778 * from the OOB buffer and copy them into buf.
1780 * Returns zero on success, a negative error code otherwise.
1782 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1783 const u8 *oobbuf, int start, int nbytes,
1784 int (*iter)(struct mtd_info *,
1786 struct mtd_oob_region *oobregion))
1788 struct mtd_oob_region oobregion;
1791 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1797 cnt = min_t(int, nbytes, oobregion.length);
1798 memcpy(buf, oobbuf + oobregion.offset, cnt);
1805 ret = iter(mtd, ++section, &oobregion);
1812 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1813 * @mtd: mtd info structure
1814 * @buf: source buffer to get OOB bytes from
1815 * @oobbuf: OOB buffer
1816 * @start: first OOB byte to set
1817 * @nbytes: number of OOB bytes to set
1818 * @iter: section iterator
1820 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1821 * is selected by passing the appropriate iterator.
1823 * Returns zero on success, a negative error code otherwise.
1825 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1826 u8 *oobbuf, int start, int nbytes,
1827 int (*iter)(struct mtd_info *,
1829 struct mtd_oob_region *oobregion))
1831 struct mtd_oob_region oobregion;
1834 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1840 cnt = min_t(int, nbytes, oobregion.length);
1841 memcpy(oobbuf + oobregion.offset, buf, cnt);
1848 ret = iter(mtd, ++section, &oobregion);
1855 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1856 * @mtd: mtd info structure
1857 * @iter: category iterator
1859 * Count the number of bytes in a given category.
1861 * Returns a positive value on success, a negative error code otherwise.
1863 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1864 int (*iter)(struct mtd_info *,
1866 struct mtd_oob_region *oobregion))
1868 struct mtd_oob_region oobregion;
1869 int section = 0, ret, nbytes = 0;
1872 ret = iter(mtd, section++, &oobregion);
1879 nbytes += oobregion.length;
1886 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1887 * @mtd: mtd info structure
1888 * @eccbuf: destination buffer to store ECC bytes
1889 * @oobbuf: OOB buffer
1890 * @start: first ECC byte to retrieve
1891 * @nbytes: number of ECC bytes to retrieve
1893 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1895 * Returns zero on success, a negative error code otherwise.
1897 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1898 const u8 *oobbuf, int start, int nbytes)
1900 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1903 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1906 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1907 * @mtd: mtd info structure
1908 * @eccbuf: source buffer to get ECC bytes from
1909 * @oobbuf: OOB buffer
1910 * @start: first ECC byte to set
1911 * @nbytes: number of ECC bytes to set
1913 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1915 * Returns zero on success, a negative error code otherwise.
1917 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1918 u8 *oobbuf, int start, int nbytes)
1920 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1923 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1926 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1927 * @mtd: mtd info structure
1928 * @databuf: destination buffer to store ECC bytes
1929 * @oobbuf: OOB buffer
1930 * @start: first ECC byte to retrieve
1931 * @nbytes: number of ECC bytes to retrieve
1933 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1935 * Returns zero on success, a negative error code otherwise.
1937 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1938 const u8 *oobbuf, int start, int nbytes)
1940 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1941 mtd_ooblayout_free);
1943 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1946 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1947 * @mtd: mtd info structure
1948 * @databuf: source buffer to get data bytes from
1949 * @oobbuf: OOB buffer
1950 * @start: first ECC byte to set
1951 * @nbytes: number of ECC bytes to set
1953 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
1955 * Returns zero on success, a negative error code otherwise.
1957 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1958 u8 *oobbuf, int start, int nbytes)
1960 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1961 mtd_ooblayout_free);
1963 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1966 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1967 * @mtd: mtd info structure
1969 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1971 * Returns zero on success, a negative error code otherwise.
1973 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1975 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1977 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1980 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1981 * @mtd: mtd info structure
1983 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1985 * Returns zero on success, a negative error code otherwise.
1987 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1989 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1991 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1994 * Method to access the protection register area, present in some flash
1995 * devices. The user data is one time programmable but the factory data is read
1998 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1999 struct otp_info *buf)
2001 struct mtd_info *master = mtd_get_master(mtd);
2003 if (!master->_get_fact_prot_info)
2007 return master->_get_fact_prot_info(master, len, retlen, buf);
2009 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
2011 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2012 size_t *retlen, u_char *buf)
2014 struct mtd_info *master = mtd_get_master(mtd);
2017 if (!master->_read_fact_prot_reg)
2021 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
2023 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
2025 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2026 struct otp_info *buf)
2028 struct mtd_info *master = mtd_get_master(mtd);
2030 if (!master->_get_user_prot_info)
2034 return master->_get_user_prot_info(master, len, retlen, buf);
2036 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
2038 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2039 size_t *retlen, u_char *buf)
2041 struct mtd_info *master = mtd_get_master(mtd);
2044 if (!master->_read_user_prot_reg)
2048 return master->_read_user_prot_reg(master, from, len, retlen, buf);
2050 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
2052 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
2053 size_t *retlen, const u_char *buf)
2055 struct mtd_info *master = mtd_get_master(mtd);
2059 if (!master->_write_user_prot_reg)
2063 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
2068 * If no data could be written at all, we are out of memory and
2069 * must return -ENOSPC.
2071 return (*retlen) ? 0 : -ENOSPC;
2073 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
2075 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2077 struct mtd_info *master = mtd_get_master(mtd);
2079 if (!master->_lock_user_prot_reg)
2083 return master->_lock_user_prot_reg(master, from, len);
2085 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
2087 int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2089 struct mtd_info *master = mtd_get_master(mtd);
2091 if (!master->_erase_user_prot_reg)
2095 return master->_erase_user_prot_reg(master, from, len);
2097 EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
2099 /* Chip-supported device locking */
2100 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2102 struct mtd_info *master = mtd_get_master(mtd);
2106 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2111 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2112 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2113 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2116 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
2118 EXPORT_SYMBOL_GPL(mtd_lock);
2120 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2122 struct mtd_info *master = mtd_get_master(mtd);
2124 if (!master->_unlock)
2126 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2131 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2132 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2133 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2136 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
2138 EXPORT_SYMBOL_GPL(mtd_unlock);
2140 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2142 struct mtd_info *master = mtd_get_master(mtd);
2144 if (!master->_is_locked)
2146 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2151 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2152 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2153 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2156 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
2158 EXPORT_SYMBOL_GPL(mtd_is_locked);
2160 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2162 struct mtd_info *master = mtd_get_master(mtd);
2164 if (ofs < 0 || ofs >= mtd->size)
2166 if (!master->_block_isreserved)
2169 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2170 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2172 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2174 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2176 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2178 struct mtd_info *master = mtd_get_master(mtd);
2180 if (ofs < 0 || ofs >= mtd->size)
2182 if (!master->_block_isbad)
2185 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2186 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2188 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2190 EXPORT_SYMBOL_GPL(mtd_block_isbad);
2192 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2194 struct mtd_info *master = mtd_get_master(mtd);
2197 if (!master->_block_markbad)
2199 if (ofs < 0 || ofs >= mtd->size)
2201 if (!(mtd->flags & MTD_WRITEABLE))
2204 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2205 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2207 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2211 while (mtd->parent) {
2212 mtd->ecc_stats.badblocks++;
2218 EXPORT_SYMBOL_GPL(mtd_block_markbad);
2221 * default_mtd_writev - the default writev method
2222 * @mtd: mtd device description object pointer
2223 * @vecs: the vectors to write
2224 * @count: count of vectors in @vecs
2225 * @to: the MTD device offset to write to
2226 * @retlen: on exit contains the count of bytes written to the MTD device.
2228 * This function returns zero in case of success and a negative error code in
2231 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2232 unsigned long count, loff_t to, size_t *retlen)
2235 size_t totlen = 0, thislen;
2238 for (i = 0; i < count; i++) {
2239 if (!vecs[i].iov_len)
2241 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2244 if (ret || thislen != vecs[i].iov_len)
2246 to += vecs[i].iov_len;
2253 * mtd_writev - the vector-based MTD write method
2254 * @mtd: mtd device description object pointer
2255 * @vecs: the vectors to write
2256 * @count: count of vectors in @vecs
2257 * @to: the MTD device offset to write to
2258 * @retlen: on exit contains the count of bytes written to the MTD device.
2260 * This function returns zero in case of success and a negative error code in
2263 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2264 unsigned long count, loff_t to, size_t *retlen)
2266 struct mtd_info *master = mtd_get_master(mtd);
2269 if (!(mtd->flags & MTD_WRITEABLE))
2272 if (!master->_writev)
2273 return default_mtd_writev(mtd, vecs, count, to, retlen);
2275 return master->_writev(master, vecs, count,
2276 mtd_get_master_ofs(mtd, to), retlen);
2278 EXPORT_SYMBOL_GPL(mtd_writev);
2281 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2282 * @mtd: mtd device description object pointer
2283 * @size: a pointer to the ideal or maximum size of the allocation, points
2284 * to the actual allocation size on success.
2286 * This routine attempts to allocate a contiguous kernel buffer up to
2287 * the specified size, backing off the size of the request exponentially
2288 * until the request succeeds or until the allocation size falls below
2289 * the system page size. This attempts to make sure it does not adversely
2290 * impact system performance, so when allocating more than one page, we
2291 * ask the memory allocator to avoid re-trying, swapping, writing back
2292 * or performing I/O.
2294 * Note, this function also makes sure that the allocated buffer is aligned to
2295 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2297 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2298 * to handle smaller (i.e. degraded) buffer allocations under low- or
2299 * fragmented-memory situations where such reduced allocations, from a
2300 * requested ideal, are allowed.
2302 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2304 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2306 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2307 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2310 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2312 while (*size > min_alloc) {
2313 kbuf = kmalloc(*size, flags);
2318 *size = ALIGN(*size, mtd->writesize);
2322 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2323 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2325 return kmalloc(*size, GFP_KERNEL);
2327 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2329 #ifdef CONFIG_PROC_FS
2331 /*====================================================================*/
2332 /* Support for /proc/mtd */
2334 static int mtd_proc_show(struct seq_file *m, void *v)
2336 struct mtd_info *mtd;
2338 seq_puts(m, "dev: size erasesize name\n");
2339 mutex_lock(&mtd_table_mutex);
2340 mtd_for_each_device(mtd) {
2341 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2342 mtd->index, (unsigned long long)mtd->size,
2343 mtd->erasesize, mtd->name);
2345 mutex_unlock(&mtd_table_mutex);
2348 #endif /* CONFIG_PROC_FS */
2350 /*====================================================================*/
2353 static struct backing_dev_info * __init mtd_bdi_init(const char *name)
2355 struct backing_dev_info *bdi;
2358 bdi = bdi_alloc(NUMA_NO_NODE);
2360 return ERR_PTR(-ENOMEM);
2365 * We put '-0' suffix to the name to get the same name format as we
2366 * used to get. Since this is called only once, we get a unique name.
2368 ret = bdi_register(bdi, "%.28s-0", name);
2372 return ret ? ERR_PTR(ret) : bdi;
2375 char *mtd_expert_analysis_warning =
2376 "Bad block checks have been entirely disabled.\n"
2377 "This is only reserved for post-mortem forensics and debug purposes.\n"
2378 "Never enable this mode if you do not know what you are doing!\n";
2379 EXPORT_SYMBOL_GPL(mtd_expert_analysis_warning);
2380 bool mtd_expert_analysis_mode;
2381 EXPORT_SYMBOL_GPL(mtd_expert_analysis_mode);
2383 static struct proc_dir_entry *proc_mtd;
2385 static int __init init_mtd(void)
2389 ret = class_register(&mtd_class);
2393 mtd_bdi = mtd_bdi_init("mtd");
2394 if (IS_ERR(mtd_bdi)) {
2395 ret = PTR_ERR(mtd_bdi);
2399 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2401 ret = init_mtdchar();
2405 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2406 debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd,
2407 &mtd_expert_analysis_mode);
2413 remove_proc_entry("mtd", NULL);
2416 class_unregister(&mtd_class);
2418 pr_err("Error registering mtd class or bdi: %d\n", ret);
2422 static void __exit cleanup_mtd(void)
2424 debugfs_remove_recursive(dfs_dir_mtd);
2427 remove_proc_entry("mtd", NULL);
2428 class_unregister(&mtd_class);
2429 bdi_unregister(mtd_bdi);
2431 idr_destroy(&mtd_idr);
2434 module_init(init_mtd);
2435 module_exit(cleanup_mtd);
2437 MODULE_LICENSE("GPL");
2438 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2439 MODULE_DESCRIPTION("Core MTD registration and access routines");