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.no_of_node = !of_device_is_compatible(node, "nvmem-cells");
552 mtd->nvmem = nvmem_register(&config);
553 if (IS_ERR(mtd->nvmem)) {
554 /* Just ignore if there is no NVMEM support in the kernel */
555 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
558 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
559 return PTR_ERR(mtd->nvmem);
567 * add_mtd_device - register an MTD device
568 * @mtd: pointer to new MTD device info structure
570 * Add a device to the list of MTD devices present in the system, and
571 * notify each currently active MTD 'user' of its arrival. Returns
572 * zero on success or non-zero on failure.
575 int add_mtd_device(struct mtd_info *mtd)
577 struct mtd_info *master = mtd_get_master(mtd);
578 struct mtd_notifier *not;
582 * May occur, for instance, on buggy drivers which call
583 * mtd_device_parse_register() multiple times on the same master MTD,
584 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
586 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
589 BUG_ON(mtd->writesize == 0);
592 * MTD drivers should implement ->_{write,read}() or
593 * ->_{write,read}_oob(), but not both.
595 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
596 (mtd->_read && mtd->_read_oob)))
599 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
600 !(mtd->flags & MTD_NO_ERASE)))
604 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
605 * master is an MLC NAND and has a proper pairing scheme defined.
606 * We also reject masters that implement ->_writev() for now, because
607 * NAND controller drivers don't implement this hook, and adding the
608 * SLC -> MLC address/length conversion to this path is useless if we
611 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
612 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
613 !master->pairing || master->_writev))
616 mutex_lock(&mtd_table_mutex);
618 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
627 /* default value if not set by driver */
628 if (mtd->bitflip_threshold == 0)
629 mtd->bitflip_threshold = mtd->ecc_strength;
631 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
632 int ngroups = mtd_pairing_groups(master);
634 mtd->erasesize /= ngroups;
635 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
639 if (is_power_of_2(mtd->erasesize))
640 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
642 mtd->erasesize_shift = 0;
644 if (is_power_of_2(mtd->writesize))
645 mtd->writesize_shift = ffs(mtd->writesize) - 1;
647 mtd->writesize_shift = 0;
649 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
650 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
652 /* Some chips always power up locked. Unlock them now */
653 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
654 error = mtd_unlock(mtd, 0, mtd->size);
655 if (error && error != -EOPNOTSUPP)
657 "%s: unlock failed, writes may not work\n",
659 /* Ignore unlock failures? */
663 /* Caller should have set dev.parent to match the
664 * physical device, if appropriate.
666 mtd->dev.type = &mtd_devtype;
667 mtd->dev.class = &mtd_class;
668 mtd->dev.devt = MTD_DEVT(i);
669 dev_set_name(&mtd->dev, "mtd%d", i);
670 dev_set_drvdata(&mtd->dev, mtd);
671 of_node_get(mtd_get_of_node(mtd));
672 error = device_register(&mtd->dev);
676 /* Add the nvmem provider */
677 error = mtd_nvmem_add(mtd);
681 mtd_debugfs_populate(mtd);
683 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
686 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
687 /* No need to get a refcount on the module containing
688 the notifier, since we hold the mtd_table_mutex */
689 list_for_each_entry(not, &mtd_notifiers, list)
692 mutex_unlock(&mtd_table_mutex);
693 /* We _know_ we aren't being removed, because
694 our caller is still holding us here. So none
695 of this try_ nonsense, and no bitching about it
697 __module_get(THIS_MODULE);
701 device_unregister(&mtd->dev);
703 of_node_put(mtd_get_of_node(mtd));
704 idr_remove(&mtd_idr, i);
706 mutex_unlock(&mtd_table_mutex);
711 * del_mtd_device - unregister an MTD device
712 * @mtd: pointer to MTD device info structure
714 * Remove a device from the list of MTD devices present in the system,
715 * and notify each currently active MTD 'user' of its departure.
716 * Returns zero on success or 1 on failure, which currently will happen
717 * if the requested device does not appear to be present in the list.
720 int del_mtd_device(struct mtd_info *mtd)
723 struct mtd_notifier *not;
725 mutex_lock(&mtd_table_mutex);
727 debugfs_remove_recursive(mtd->dbg.dfs_dir);
729 if (idr_find(&mtd_idr, mtd->index) != mtd) {
734 /* No need to get a refcount on the module containing
735 the notifier, since we hold the mtd_table_mutex */
736 list_for_each_entry(not, &mtd_notifiers, list)
740 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
741 mtd->index, mtd->name, mtd->usecount);
744 /* Try to remove the NVMEM provider */
746 nvmem_unregister(mtd->nvmem);
748 device_unregister(&mtd->dev);
750 idr_remove(&mtd_idr, mtd->index);
751 of_node_put(mtd_get_of_node(mtd));
753 module_put(THIS_MODULE);
758 mutex_unlock(&mtd_table_mutex);
763 * Set a few defaults based on the parent devices, if not provided by the
766 static void mtd_set_dev_defaults(struct mtd_info *mtd)
768 if (mtd->dev.parent) {
769 if (!mtd->owner && mtd->dev.parent->driver)
770 mtd->owner = mtd->dev.parent->driver->owner;
772 mtd->name = dev_name(mtd->dev.parent);
774 pr_debug("mtd device won't show a device symlink in sysfs\n");
777 INIT_LIST_HEAD(&mtd->partitions);
778 mutex_init(&mtd->master.partitions_lock);
779 mutex_init(&mtd->master.chrdev_lock);
782 static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
784 struct otp_info *info;
790 info = kmalloc(PAGE_SIZE, GFP_KERNEL);
795 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info);
797 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info);
801 for (i = 0; i < retlen / sizeof(*info); i++)
802 size += info[i].length;
812 static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
813 const char *compatible,
815 nvmem_reg_read_t reg_read)
817 struct nvmem_device *nvmem = NULL;
818 struct nvmem_config config = {};
819 struct device_node *np;
821 /* DT binding is optional */
822 np = of_get_compatible_child(mtd->dev.of_node, compatible);
824 /* OTP nvmem will be registered on the physical device */
825 config.dev = mtd->dev.parent;
826 /* just reuse the compatible as name */
827 config.name = compatible;
828 config.id = NVMEM_DEVID_NONE;
829 config.owner = THIS_MODULE;
830 config.type = NVMEM_TYPE_OTP;
831 config.root_only = true;
832 config.reg_read = reg_read;
837 nvmem = nvmem_register(&config);
838 /* Just ignore if there is no NVMEM support in the kernel */
839 if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP)
847 static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
848 void *val, size_t bytes)
850 struct mtd_info *mtd = priv;
854 ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val);
858 return retlen == bytes ? 0 : -EIO;
861 static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
862 void *val, size_t bytes)
864 struct mtd_info *mtd = priv;
868 ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val);
872 return retlen == bytes ? 0 : -EIO;
875 static int mtd_otp_nvmem_add(struct mtd_info *mtd)
877 struct nvmem_device *nvmem;
881 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
882 size = mtd_otp_size(mtd, true);
887 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
888 mtd_nvmem_user_otp_reg_read);
890 dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
891 return PTR_ERR(nvmem);
893 mtd->otp_user_nvmem = nvmem;
897 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
898 size = mtd_otp_size(mtd, false);
905 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
906 mtd_nvmem_fact_otp_reg_read);
908 dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
909 err = PTR_ERR(nvmem);
912 mtd->otp_factory_nvmem = nvmem;
919 if (mtd->otp_user_nvmem)
920 nvmem_unregister(mtd->otp_user_nvmem);
925 * mtd_device_parse_register - parse partitions and register an MTD device.
927 * @mtd: the MTD device to register
928 * @types: the list of MTD partition probes to try, see
929 * 'parse_mtd_partitions()' for more information
930 * @parser_data: MTD partition parser-specific data
931 * @parts: fallback partition information to register, if parsing fails;
932 * only valid if %nr_parts > %0
933 * @nr_parts: the number of partitions in parts, if zero then the full
934 * MTD device is registered if no partition info is found
936 * This function aggregates MTD partitions parsing (done by
937 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
938 * basically follows the most common pattern found in many MTD drivers:
940 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
942 * * Then It tries to probe partitions on MTD device @mtd using parsers
943 * specified in @types (if @types is %NULL, then the default list of parsers
944 * is used, see 'parse_mtd_partitions()' for more information). If none are
945 * found this functions tries to fallback to information specified in
947 * * If no partitions were found this function just registers the MTD device
950 * Returns zero in case of success and a negative error code in case of failure.
952 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
953 struct mtd_part_parser_data *parser_data,
954 const struct mtd_partition *parts,
959 mtd_set_dev_defaults(mtd);
961 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
962 ret = add_mtd_device(mtd);
967 /* Prefer parsed partitions over driver-provided fallback */
968 ret = parse_mtd_partitions(mtd, types, parser_data);
969 if (ret == -EPROBE_DEFER)
975 ret = add_mtd_partitions(mtd, parts, nr_parts);
976 else if (!device_is_registered(&mtd->dev))
977 ret = add_mtd_device(mtd);
985 * FIXME: some drivers unfortunately call this function more than once.
986 * So we have to check if we've already assigned the reboot notifier.
988 * Generally, we can make multiple calls work for most cases, but it
989 * does cause problems with parse_mtd_partitions() above (e.g.,
990 * cmdlineparts will register partitions more than once).
992 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
993 "MTD already registered\n");
994 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
995 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
996 register_reboot_notifier(&mtd->reboot_notifier);
999 ret = mtd_otp_nvmem_add(mtd);
1002 if (ret && device_is_registered(&mtd->dev))
1003 del_mtd_device(mtd);
1007 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
1010 * mtd_device_unregister - unregister an existing MTD device.
1012 * @master: the MTD device to unregister. This will unregister both the master
1013 * and any partitions if registered.
1015 int mtd_device_unregister(struct mtd_info *master)
1019 if (master->_reboot)
1020 unregister_reboot_notifier(&master->reboot_notifier);
1022 if (master->otp_user_nvmem)
1023 nvmem_unregister(master->otp_user_nvmem);
1025 if (master->otp_factory_nvmem)
1026 nvmem_unregister(master->otp_factory_nvmem);
1028 err = del_mtd_partitions(master);
1032 if (!device_is_registered(&master->dev))
1035 return del_mtd_device(master);
1037 EXPORT_SYMBOL_GPL(mtd_device_unregister);
1040 * register_mtd_user - register a 'user' of MTD devices.
1041 * @new: pointer to notifier info structure
1043 * Registers a pair of callbacks function to be called upon addition
1044 * or removal of MTD devices. Causes the 'add' callback to be immediately
1045 * invoked for each MTD device currently present in the system.
1047 void register_mtd_user (struct mtd_notifier *new)
1049 struct mtd_info *mtd;
1051 mutex_lock(&mtd_table_mutex);
1053 list_add(&new->list, &mtd_notifiers);
1055 __module_get(THIS_MODULE);
1057 mtd_for_each_device(mtd)
1060 mutex_unlock(&mtd_table_mutex);
1062 EXPORT_SYMBOL_GPL(register_mtd_user);
1065 * unregister_mtd_user - unregister a 'user' of MTD devices.
1066 * @old: pointer to notifier info structure
1068 * Removes a callback function pair from the list of 'users' to be
1069 * notified upon addition or removal of MTD devices. Causes the
1070 * 'remove' callback to be immediately invoked for each MTD device
1071 * currently present in the system.
1073 int unregister_mtd_user (struct mtd_notifier *old)
1075 struct mtd_info *mtd;
1077 mutex_lock(&mtd_table_mutex);
1079 module_put(THIS_MODULE);
1081 mtd_for_each_device(mtd)
1084 list_del(&old->list);
1085 mutex_unlock(&mtd_table_mutex);
1088 EXPORT_SYMBOL_GPL(unregister_mtd_user);
1091 * get_mtd_device - obtain a validated handle for an MTD device
1092 * @mtd: last known address of the required MTD device
1093 * @num: internal device number of the required MTD device
1095 * Given a number and NULL address, return the num'th entry in the device
1096 * table, if any. Given an address and num == -1, search the device table
1097 * for a device with that address and return if it's still present. Given
1098 * both, return the num'th driver only if its address matches. Return
1099 * error code if not.
1101 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
1103 struct mtd_info *ret = NULL, *other;
1106 mutex_lock(&mtd_table_mutex);
1109 mtd_for_each_device(other) {
1115 } else if (num >= 0) {
1116 ret = idr_find(&mtd_idr, num);
1117 if (mtd && mtd != ret)
1126 err = __get_mtd_device(ret);
1130 mutex_unlock(&mtd_table_mutex);
1133 EXPORT_SYMBOL_GPL(get_mtd_device);
1136 int __get_mtd_device(struct mtd_info *mtd)
1138 struct mtd_info *master = mtd_get_master(mtd);
1141 if (!try_module_get(master->owner))
1144 if (master->_get_device) {
1145 err = master->_get_device(mtd);
1148 module_put(master->owner);
1155 while (mtd->parent) {
1162 EXPORT_SYMBOL_GPL(__get_mtd_device);
1165 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1167 * @name: MTD device name to open
1169 * This function returns MTD device description structure in case of
1170 * success and an error code in case of failure.
1172 struct mtd_info *get_mtd_device_nm(const char *name)
1175 struct mtd_info *mtd = NULL, *other;
1177 mutex_lock(&mtd_table_mutex);
1179 mtd_for_each_device(other) {
1180 if (!strcmp(name, other->name)) {
1189 err = __get_mtd_device(mtd);
1193 mutex_unlock(&mtd_table_mutex);
1197 mutex_unlock(&mtd_table_mutex);
1198 return ERR_PTR(err);
1200 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1202 void put_mtd_device(struct mtd_info *mtd)
1204 mutex_lock(&mtd_table_mutex);
1205 __put_mtd_device(mtd);
1206 mutex_unlock(&mtd_table_mutex);
1209 EXPORT_SYMBOL_GPL(put_mtd_device);
1211 void __put_mtd_device(struct mtd_info *mtd)
1213 struct mtd_info *master = mtd_get_master(mtd);
1215 while (mtd->parent) {
1217 BUG_ON(mtd->usecount < 0);
1223 if (master->_put_device)
1224 master->_put_device(master);
1226 module_put(master->owner);
1228 EXPORT_SYMBOL_GPL(__put_mtd_device);
1231 * Erase is an synchronous operation. Device drivers are epected to return a
1232 * negative error code if the operation failed and update instr->fail_addr
1233 * to point the portion that was not properly erased.
1235 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1237 struct mtd_info *master = mtd_get_master(mtd);
1238 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1239 struct erase_info adjinstr;
1242 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1245 if (!mtd->erasesize || !master->_erase)
1248 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1250 if (!(mtd->flags & MTD_WRITEABLE))
1256 ledtrig_mtd_activity();
1258 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1259 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1261 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1262 master->erasesize) -
1266 adjinstr.addr += mst_ofs;
1268 ret = master->_erase(master, &adjinstr);
1270 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1271 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1272 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1273 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1275 instr->fail_addr *= mtd->erasesize;
1281 EXPORT_SYMBOL_GPL(mtd_erase);
1284 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1286 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1287 void **virt, resource_size_t *phys)
1289 struct mtd_info *master = mtd_get_master(mtd);
1295 if (!master->_point)
1297 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1302 from = mtd_get_master_ofs(mtd, from);
1303 return master->_point(master, from, len, retlen, virt, phys);
1305 EXPORT_SYMBOL_GPL(mtd_point);
1307 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1308 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1310 struct mtd_info *master = mtd_get_master(mtd);
1312 if (!master->_unpoint)
1314 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1318 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1320 EXPORT_SYMBOL_GPL(mtd_unpoint);
1323 * Allow NOMMU mmap() to directly map the device (if not NULL)
1324 * - return the address to which the offset maps
1325 * - return -ENOSYS to indicate refusal to do the mapping
1327 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1328 unsigned long offset, unsigned long flags)
1334 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1337 if (retlen != len) {
1338 mtd_unpoint(mtd, offset, retlen);
1341 return (unsigned long)virt;
1343 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1345 static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1346 const struct mtd_ecc_stats *old_stats)
1348 struct mtd_ecc_stats diff;
1353 diff = master->ecc_stats;
1354 diff.failed -= old_stats->failed;
1355 diff.corrected -= old_stats->corrected;
1357 while (mtd->parent) {
1358 mtd->ecc_stats.failed += diff.failed;
1359 mtd->ecc_stats.corrected += diff.corrected;
1364 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1367 struct mtd_oob_ops ops = {
1373 ret = mtd_read_oob(mtd, from, &ops);
1374 *retlen = ops.retlen;
1378 EXPORT_SYMBOL_GPL(mtd_read);
1380 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1383 struct mtd_oob_ops ops = {
1385 .datbuf = (u8 *)buf,
1389 ret = mtd_write_oob(mtd, to, &ops);
1390 *retlen = ops.retlen;
1394 EXPORT_SYMBOL_GPL(mtd_write);
1397 * In blackbox flight recorder like scenarios we want to make successful writes
1398 * in interrupt context. panic_write() is only intended to be called when its
1399 * known the kernel is about to panic and we need the write to succeed. Since
1400 * the kernel is not going to be running for much longer, this function can
1401 * break locks and delay to ensure the write succeeds (but not sleep).
1403 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1406 struct mtd_info *master = mtd_get_master(mtd);
1409 if (!master->_panic_write)
1411 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1413 if (!(mtd->flags & MTD_WRITEABLE))
1417 if (!master->oops_panic_write)
1418 master->oops_panic_write = true;
1420 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1423 EXPORT_SYMBOL_GPL(mtd_panic_write);
1425 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1426 struct mtd_oob_ops *ops)
1429 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1430 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1439 if (offs < 0 || offs + ops->len > mtd->size)
1445 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1448 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1449 mtd_div_by_ws(offs, mtd)) *
1450 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1451 if (ops->ooblen > maxooblen)
1458 static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1459 struct mtd_oob_ops *ops)
1461 struct mtd_info *master = mtd_get_master(mtd);
1464 from = mtd_get_master_ofs(mtd, from);
1465 if (master->_read_oob)
1466 ret = master->_read_oob(master, from, ops);
1468 ret = master->_read(master, from, ops->len, &ops->retlen,
1474 static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1475 struct mtd_oob_ops *ops)
1477 struct mtd_info *master = mtd_get_master(mtd);
1480 to = mtd_get_master_ofs(mtd, to);
1481 if (master->_write_oob)
1482 ret = master->_write_oob(master, to, ops);
1484 ret = master->_write(master, to, ops->len, &ops->retlen,
1490 static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1491 struct mtd_oob_ops *ops)
1493 struct mtd_info *master = mtd_get_master(mtd);
1494 int ngroups = mtd_pairing_groups(master);
1495 int npairs = mtd_wunit_per_eb(master) / ngroups;
1496 struct mtd_oob_ops adjops = *ops;
1497 unsigned int wunit, oobavail;
1498 struct mtd_pairing_info info;
1499 int max_bitflips = 0;
1503 ebofs = mtd_mod_by_eb(start, mtd);
1504 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1506 info.pair = mtd_div_by_ws(ebofs, mtd);
1507 pageofs = mtd_mod_by_ws(ebofs, mtd);
1508 oobavail = mtd_oobavail(mtd, ops);
1510 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1513 if (info.pair >= npairs) {
1515 base += master->erasesize;
1518 wunit = mtd_pairing_info_to_wunit(master, &info);
1519 pos = mtd_wunit_to_offset(mtd, base, wunit);
1521 adjops.len = ops->len - ops->retlen;
1522 if (adjops.len > mtd->writesize - pageofs)
1523 adjops.len = mtd->writesize - pageofs;
1525 adjops.ooblen = ops->ooblen - ops->oobretlen;
1526 if (adjops.ooblen > oobavail - adjops.ooboffs)
1527 adjops.ooblen = oobavail - adjops.ooboffs;
1530 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1532 max_bitflips = max(max_bitflips, ret);
1534 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1540 max_bitflips = max(max_bitflips, ret);
1541 ops->retlen += adjops.retlen;
1542 ops->oobretlen += adjops.oobretlen;
1543 adjops.datbuf += adjops.retlen;
1544 adjops.oobbuf += adjops.oobretlen;
1550 return max_bitflips;
1553 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1555 struct mtd_info *master = mtd_get_master(mtd);
1556 struct mtd_ecc_stats old_stats = master->ecc_stats;
1559 ops->retlen = ops->oobretlen = 0;
1561 ret_code = mtd_check_oob_ops(mtd, from, ops);
1565 ledtrig_mtd_activity();
1567 /* Check the validity of a potential fallback on mtd->_read */
1568 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1571 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1572 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1574 ret_code = mtd_read_oob_std(mtd, from, ops);
1576 mtd_update_ecc_stats(mtd, master, &old_stats);
1579 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1580 * similar to mtd->_read(), returning a non-negative integer
1581 * representing max bitflips. In other cases, mtd->_read_oob() may
1582 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1584 if (unlikely(ret_code < 0))
1586 if (mtd->ecc_strength == 0)
1587 return 0; /* device lacks ecc */
1588 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1590 EXPORT_SYMBOL_GPL(mtd_read_oob);
1592 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1593 struct mtd_oob_ops *ops)
1595 struct mtd_info *master = mtd_get_master(mtd);
1598 ops->retlen = ops->oobretlen = 0;
1600 if (!(mtd->flags & MTD_WRITEABLE))
1603 ret = mtd_check_oob_ops(mtd, to, ops);
1607 ledtrig_mtd_activity();
1609 /* Check the validity of a potential fallback on mtd->_write */
1610 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1613 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1614 return mtd_io_emulated_slc(mtd, to, false, ops);
1616 return mtd_write_oob_std(mtd, to, ops);
1618 EXPORT_SYMBOL_GPL(mtd_write_oob);
1621 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1622 * @mtd: MTD device structure
1623 * @section: ECC section. Depending on the layout you may have all the ECC
1624 * bytes stored in a single contiguous section, or one section
1625 * per ECC chunk (and sometime several sections for a single ECC
1627 * @oobecc: OOB region struct filled with the appropriate ECC position
1630 * This function returns ECC section information in the OOB area. If you want
1631 * to get all the ECC bytes information, then you should call
1632 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1634 * Returns zero on success, a negative error code otherwise.
1636 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1637 struct mtd_oob_region *oobecc)
1639 struct mtd_info *master = mtd_get_master(mtd);
1641 memset(oobecc, 0, sizeof(*oobecc));
1643 if (!master || section < 0)
1646 if (!master->ooblayout || !master->ooblayout->ecc)
1649 return master->ooblayout->ecc(master, section, oobecc);
1651 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1654 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1656 * @mtd: MTD device structure
1657 * @section: Free section you are interested in. Depending on the layout
1658 * you may have all the free bytes stored in a single contiguous
1659 * section, or one section per ECC chunk plus an extra section
1660 * for the remaining bytes (or other funky layout).
1661 * @oobfree: OOB region struct filled with the appropriate free position
1664 * This function returns free bytes position in the OOB area. If you want
1665 * to get all the free bytes information, then you should call
1666 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1668 * Returns zero on success, a negative error code otherwise.
1670 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1671 struct mtd_oob_region *oobfree)
1673 struct mtd_info *master = mtd_get_master(mtd);
1675 memset(oobfree, 0, sizeof(*oobfree));
1677 if (!master || section < 0)
1680 if (!master->ooblayout || !master->ooblayout->free)
1683 return master->ooblayout->free(master, section, oobfree);
1685 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1688 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1689 * @mtd: mtd info structure
1690 * @byte: the byte we are searching for
1691 * @sectionp: pointer where the section id will be stored
1692 * @oobregion: used to retrieve the ECC position
1693 * @iter: iterator function. Should be either mtd_ooblayout_free or
1694 * mtd_ooblayout_ecc depending on the region type you're searching for
1696 * This function returns the section id and oobregion information of a
1697 * specific byte. For example, say you want to know where the 4th ECC byte is
1698 * stored, you'll use:
1700 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1702 * Returns zero on success, a negative error code otherwise.
1704 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1705 int *sectionp, struct mtd_oob_region *oobregion,
1706 int (*iter)(struct mtd_info *,
1708 struct mtd_oob_region *oobregion))
1710 int pos = 0, ret, section = 0;
1712 memset(oobregion, 0, sizeof(*oobregion));
1715 ret = iter(mtd, section, oobregion);
1719 if (pos + oobregion->length > byte)
1722 pos += oobregion->length;
1727 * Adjust region info to make it start at the beginning at the
1730 oobregion->offset += byte - pos;
1731 oobregion->length -= byte - pos;
1732 *sectionp = section;
1738 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1740 * @mtd: mtd info structure
1741 * @eccbyte: the byte we are searching for
1742 * @section: pointer where the section id will be stored
1743 * @oobregion: OOB region information
1745 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1748 * Returns zero on success, a negative error code otherwise.
1750 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1752 struct mtd_oob_region *oobregion)
1754 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1757 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1760 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1761 * @mtd: mtd info structure
1762 * @buf: destination buffer to store OOB bytes
1763 * @oobbuf: OOB buffer
1764 * @start: first byte to retrieve
1765 * @nbytes: number of bytes to retrieve
1766 * @iter: section iterator
1768 * Extract bytes attached to a specific category (ECC or free)
1769 * from the OOB buffer and copy them into buf.
1771 * Returns zero on success, a negative error code otherwise.
1773 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1774 const u8 *oobbuf, int start, int nbytes,
1775 int (*iter)(struct mtd_info *,
1777 struct mtd_oob_region *oobregion))
1779 struct mtd_oob_region oobregion;
1782 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1788 cnt = min_t(int, nbytes, oobregion.length);
1789 memcpy(buf, oobbuf + oobregion.offset, cnt);
1796 ret = iter(mtd, ++section, &oobregion);
1803 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1804 * @mtd: mtd info structure
1805 * @buf: source buffer to get OOB bytes from
1806 * @oobbuf: OOB buffer
1807 * @start: first OOB byte to set
1808 * @nbytes: number of OOB bytes to set
1809 * @iter: section iterator
1811 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1812 * is selected by passing the appropriate iterator.
1814 * Returns zero on success, a negative error code otherwise.
1816 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1817 u8 *oobbuf, int start, int nbytes,
1818 int (*iter)(struct mtd_info *,
1820 struct mtd_oob_region *oobregion))
1822 struct mtd_oob_region oobregion;
1825 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1831 cnt = min_t(int, nbytes, oobregion.length);
1832 memcpy(oobbuf + oobregion.offset, buf, cnt);
1839 ret = iter(mtd, ++section, &oobregion);
1846 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1847 * @mtd: mtd info structure
1848 * @iter: category iterator
1850 * Count the number of bytes in a given category.
1852 * Returns a positive value on success, a negative error code otherwise.
1854 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1855 int (*iter)(struct mtd_info *,
1857 struct mtd_oob_region *oobregion))
1859 struct mtd_oob_region oobregion;
1860 int section = 0, ret, nbytes = 0;
1863 ret = iter(mtd, section++, &oobregion);
1870 nbytes += oobregion.length;
1877 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1878 * @mtd: mtd info structure
1879 * @eccbuf: destination buffer to store ECC bytes
1880 * @oobbuf: OOB buffer
1881 * @start: first ECC byte to retrieve
1882 * @nbytes: number of ECC bytes to retrieve
1884 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1886 * Returns zero on success, a negative error code otherwise.
1888 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1889 const u8 *oobbuf, int start, int nbytes)
1891 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1894 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1897 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1898 * @mtd: mtd info structure
1899 * @eccbuf: source buffer to get ECC bytes from
1900 * @oobbuf: OOB buffer
1901 * @start: first ECC byte to set
1902 * @nbytes: number of ECC bytes to set
1904 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1906 * Returns zero on success, a negative error code otherwise.
1908 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1909 u8 *oobbuf, int start, int nbytes)
1911 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1914 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1917 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1918 * @mtd: mtd info structure
1919 * @databuf: destination buffer to store ECC bytes
1920 * @oobbuf: OOB buffer
1921 * @start: first ECC byte to retrieve
1922 * @nbytes: number of ECC bytes to retrieve
1924 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1926 * Returns zero on success, a negative error code otherwise.
1928 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1929 const u8 *oobbuf, int start, int nbytes)
1931 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1932 mtd_ooblayout_free);
1934 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1937 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1938 * @mtd: mtd info structure
1939 * @databuf: source buffer to get data bytes from
1940 * @oobbuf: OOB buffer
1941 * @start: first ECC byte to set
1942 * @nbytes: number of ECC bytes to set
1944 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
1946 * Returns zero on success, a negative error code otherwise.
1948 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1949 u8 *oobbuf, int start, int nbytes)
1951 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1952 mtd_ooblayout_free);
1954 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1957 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1958 * @mtd: mtd info structure
1960 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1962 * Returns zero on success, a negative error code otherwise.
1964 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1966 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1968 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1971 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1972 * @mtd: mtd info structure
1974 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1976 * Returns zero on success, a negative error code otherwise.
1978 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1980 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1982 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1985 * Method to access the protection register area, present in some flash
1986 * devices. The user data is one time programmable but the factory data is read
1989 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1990 struct otp_info *buf)
1992 struct mtd_info *master = mtd_get_master(mtd);
1994 if (!master->_get_fact_prot_info)
1998 return master->_get_fact_prot_info(master, len, retlen, buf);
2000 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
2002 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2003 size_t *retlen, u_char *buf)
2005 struct mtd_info *master = mtd_get_master(mtd);
2008 if (!master->_read_fact_prot_reg)
2012 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
2014 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
2016 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2017 struct otp_info *buf)
2019 struct mtd_info *master = mtd_get_master(mtd);
2021 if (!master->_get_user_prot_info)
2025 return master->_get_user_prot_info(master, len, retlen, buf);
2027 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
2029 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2030 size_t *retlen, u_char *buf)
2032 struct mtd_info *master = mtd_get_master(mtd);
2035 if (!master->_read_user_prot_reg)
2039 return master->_read_user_prot_reg(master, from, len, retlen, buf);
2041 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
2043 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
2044 size_t *retlen, const u_char *buf)
2046 struct mtd_info *master = mtd_get_master(mtd);
2050 if (!master->_write_user_prot_reg)
2054 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
2059 * If no data could be written at all, we are out of memory and
2060 * must return -ENOSPC.
2062 return (*retlen) ? 0 : -ENOSPC;
2064 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
2066 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2068 struct mtd_info *master = mtd_get_master(mtd);
2070 if (!master->_lock_user_prot_reg)
2074 return master->_lock_user_prot_reg(master, from, len);
2076 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
2078 int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2080 struct mtd_info *master = mtd_get_master(mtd);
2082 if (!master->_erase_user_prot_reg)
2086 return master->_erase_user_prot_reg(master, from, len);
2088 EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
2090 /* Chip-supported device locking */
2091 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2093 struct mtd_info *master = mtd_get_master(mtd);
2097 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2102 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2103 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2104 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2107 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
2109 EXPORT_SYMBOL_GPL(mtd_lock);
2111 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2113 struct mtd_info *master = mtd_get_master(mtd);
2115 if (!master->_unlock)
2117 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2122 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2123 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2124 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2127 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
2129 EXPORT_SYMBOL_GPL(mtd_unlock);
2131 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2133 struct mtd_info *master = mtd_get_master(mtd);
2135 if (!master->_is_locked)
2137 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2142 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2143 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2144 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2147 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
2149 EXPORT_SYMBOL_GPL(mtd_is_locked);
2151 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2153 struct mtd_info *master = mtd_get_master(mtd);
2155 if (ofs < 0 || ofs >= mtd->size)
2157 if (!master->_block_isreserved)
2160 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2161 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2163 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2165 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2167 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2169 struct mtd_info *master = mtd_get_master(mtd);
2171 if (ofs < 0 || ofs >= mtd->size)
2173 if (!master->_block_isbad)
2176 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2177 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2179 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2181 EXPORT_SYMBOL_GPL(mtd_block_isbad);
2183 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2185 struct mtd_info *master = mtd_get_master(mtd);
2188 if (!master->_block_markbad)
2190 if (ofs < 0 || ofs >= mtd->size)
2192 if (!(mtd->flags & MTD_WRITEABLE))
2195 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2196 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2198 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2202 while (mtd->parent) {
2203 mtd->ecc_stats.badblocks++;
2209 EXPORT_SYMBOL_GPL(mtd_block_markbad);
2212 * default_mtd_writev - the default writev method
2213 * @mtd: mtd device description object pointer
2214 * @vecs: the vectors to write
2215 * @count: count of vectors in @vecs
2216 * @to: the MTD device offset to write to
2217 * @retlen: on exit contains the count of bytes written to the MTD device.
2219 * This function returns zero in case of success and a negative error code in
2222 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2223 unsigned long count, loff_t to, size_t *retlen)
2226 size_t totlen = 0, thislen;
2229 for (i = 0; i < count; i++) {
2230 if (!vecs[i].iov_len)
2232 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2235 if (ret || thislen != vecs[i].iov_len)
2237 to += vecs[i].iov_len;
2244 * mtd_writev - the vector-based MTD write method
2245 * @mtd: mtd device description object pointer
2246 * @vecs: the vectors to write
2247 * @count: count of vectors in @vecs
2248 * @to: the MTD device offset to write to
2249 * @retlen: on exit contains the count of bytes written to the MTD device.
2251 * This function returns zero in case of success and a negative error code in
2254 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2255 unsigned long count, loff_t to, size_t *retlen)
2257 struct mtd_info *master = mtd_get_master(mtd);
2260 if (!(mtd->flags & MTD_WRITEABLE))
2263 if (!master->_writev)
2264 return default_mtd_writev(mtd, vecs, count, to, retlen);
2266 return master->_writev(master, vecs, count,
2267 mtd_get_master_ofs(mtd, to), retlen);
2269 EXPORT_SYMBOL_GPL(mtd_writev);
2272 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2273 * @mtd: mtd device description object pointer
2274 * @size: a pointer to the ideal or maximum size of the allocation, points
2275 * to the actual allocation size on success.
2277 * This routine attempts to allocate a contiguous kernel buffer up to
2278 * the specified size, backing off the size of the request exponentially
2279 * until the request succeeds or until the allocation size falls below
2280 * the system page size. This attempts to make sure it does not adversely
2281 * impact system performance, so when allocating more than one page, we
2282 * ask the memory allocator to avoid re-trying, swapping, writing back
2283 * or performing I/O.
2285 * Note, this function also makes sure that the allocated buffer is aligned to
2286 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2288 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2289 * to handle smaller (i.e. degraded) buffer allocations under low- or
2290 * fragmented-memory situations where such reduced allocations, from a
2291 * requested ideal, are allowed.
2293 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2295 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2297 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2298 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2301 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2303 while (*size > min_alloc) {
2304 kbuf = kmalloc(*size, flags);
2309 *size = ALIGN(*size, mtd->writesize);
2313 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2314 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2316 return kmalloc(*size, GFP_KERNEL);
2318 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2320 #ifdef CONFIG_PROC_FS
2322 /*====================================================================*/
2323 /* Support for /proc/mtd */
2325 static int mtd_proc_show(struct seq_file *m, void *v)
2327 struct mtd_info *mtd;
2329 seq_puts(m, "dev: size erasesize name\n");
2330 mutex_lock(&mtd_table_mutex);
2331 mtd_for_each_device(mtd) {
2332 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2333 mtd->index, (unsigned long long)mtd->size,
2334 mtd->erasesize, mtd->name);
2336 mutex_unlock(&mtd_table_mutex);
2339 #endif /* CONFIG_PROC_FS */
2341 /*====================================================================*/
2344 static struct backing_dev_info * __init mtd_bdi_init(const char *name)
2346 struct backing_dev_info *bdi;
2349 bdi = bdi_alloc(NUMA_NO_NODE);
2351 return ERR_PTR(-ENOMEM);
2356 * We put '-0' suffix to the name to get the same name format as we
2357 * used to get. Since this is called only once, we get a unique name.
2359 ret = bdi_register(bdi, "%.28s-0", name);
2363 return ret ? ERR_PTR(ret) : bdi;
2366 static struct proc_dir_entry *proc_mtd;
2368 static int __init init_mtd(void)
2372 ret = class_register(&mtd_class);
2376 mtd_bdi = mtd_bdi_init("mtd");
2377 if (IS_ERR(mtd_bdi)) {
2378 ret = PTR_ERR(mtd_bdi);
2382 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2384 ret = init_mtdchar();
2388 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2394 remove_proc_entry("mtd", NULL);
2397 class_unregister(&mtd_class);
2399 pr_err("Error registering mtd class or bdi: %d\n", ret);
2403 static void __exit cleanup_mtd(void)
2405 debugfs_remove_recursive(dfs_dir_mtd);
2408 remove_proc_entry("mtd", NULL);
2409 class_unregister(&mtd_class);
2411 idr_destroy(&mtd_idr);
2414 module_init(init_mtd);
2415 module_exit(cleanup_mtd);
2417 MODULE_LICENSE("GPL");
2418 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2419 MODULE_DESCRIPTION("Core MTD registration and access routines");