2 * Core registration and callback routines for MTD
5 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
6 * Copyright © 2006 Red Hat UK Limited
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
24 #include <linux/module.h>
25 #include <linux/kernel.h>
26 #include <linux/ptrace.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/timer.h>
30 #include <linux/major.h>
32 #include <linux/err.h>
33 #include <linux/ioctl.h>
34 #include <linux/init.h>
35 #include <linux/proc_fs.h>
36 #include <linux/idr.h>
37 #include <linux/backing-dev.h>
38 #include <linux/gfp.h>
39 #include <linux/slab.h>
40 #include <linux/reboot.h>
41 #include <linux/kconfig.h>
43 #include <linux/mtd/mtd.h>
44 #include <linux/mtd/partitions.h>
48 static struct backing_dev_info mtd_bdi = {
51 #ifdef CONFIG_PM_SLEEP
53 static int mtd_cls_suspend(struct device *dev)
55 struct mtd_info *mtd = dev_get_drvdata(dev);
57 return mtd ? mtd_suspend(mtd) : 0;
60 static int mtd_cls_resume(struct device *dev)
62 struct mtd_info *mtd = dev_get_drvdata(dev);
69 static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
70 #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
72 #define MTD_CLS_PM_OPS NULL
75 static struct class mtd_class = {
81 static DEFINE_IDR(mtd_idr);
83 /* These are exported solely for the purpose of mtd_blkdevs.c. You
84 should not use them for _anything_ else */
85 DEFINE_MUTEX(mtd_table_mutex);
86 EXPORT_SYMBOL_GPL(mtd_table_mutex);
88 struct mtd_info *__mtd_next_device(int i)
90 return idr_get_next(&mtd_idr, &i);
92 EXPORT_SYMBOL_GPL(__mtd_next_device);
94 static LIST_HEAD(mtd_notifiers);
97 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
99 /* REVISIT once MTD uses the driver model better, whoever allocates
100 * the mtd_info will probably want to use the release() hook...
102 static void mtd_release(struct device *dev)
104 struct mtd_info *mtd = dev_get_drvdata(dev);
105 dev_t index = MTD_DEVT(mtd->index);
107 /* remove /dev/mtdXro node */
108 device_destroy(&mtd_class, index + 1);
111 static ssize_t mtd_type_show(struct device *dev,
112 struct device_attribute *attr, char *buf)
114 struct mtd_info *mtd = dev_get_drvdata(dev);
139 case MTD_MLCNANDFLASH:
146 return snprintf(buf, PAGE_SIZE, "%s\n", type);
148 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
150 static ssize_t mtd_flags_show(struct device *dev,
151 struct device_attribute *attr, char *buf)
153 struct mtd_info *mtd = dev_get_drvdata(dev);
155 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
158 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
160 static ssize_t mtd_size_show(struct device *dev,
161 struct device_attribute *attr, char *buf)
163 struct mtd_info *mtd = dev_get_drvdata(dev);
165 return snprintf(buf, PAGE_SIZE, "%llu\n",
166 (unsigned long long)mtd->size);
169 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
171 static ssize_t mtd_erasesize_show(struct device *dev,
172 struct device_attribute *attr, char *buf)
174 struct mtd_info *mtd = dev_get_drvdata(dev);
176 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
179 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
181 static ssize_t mtd_writesize_show(struct device *dev,
182 struct device_attribute *attr, char *buf)
184 struct mtd_info *mtd = dev_get_drvdata(dev);
186 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
189 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
191 static ssize_t mtd_subpagesize_show(struct device *dev,
192 struct device_attribute *attr, char *buf)
194 struct mtd_info *mtd = dev_get_drvdata(dev);
195 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
197 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
200 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
202 static ssize_t mtd_oobsize_show(struct device *dev,
203 struct device_attribute *attr, char *buf)
205 struct mtd_info *mtd = dev_get_drvdata(dev);
207 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
210 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
212 static ssize_t mtd_numeraseregions_show(struct device *dev,
213 struct device_attribute *attr, char *buf)
215 struct mtd_info *mtd = dev_get_drvdata(dev);
217 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
220 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
223 static ssize_t mtd_name_show(struct device *dev,
224 struct device_attribute *attr, char *buf)
226 struct mtd_info *mtd = dev_get_drvdata(dev);
228 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
231 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
233 static ssize_t mtd_ecc_strength_show(struct device *dev,
234 struct device_attribute *attr, char *buf)
236 struct mtd_info *mtd = dev_get_drvdata(dev);
238 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
240 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
242 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
243 struct device_attribute *attr,
246 struct mtd_info *mtd = dev_get_drvdata(dev);
248 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
251 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
252 struct device_attribute *attr,
253 const char *buf, size_t count)
255 struct mtd_info *mtd = dev_get_drvdata(dev);
256 unsigned int bitflip_threshold;
259 retval = kstrtouint(buf, 0, &bitflip_threshold);
263 mtd->bitflip_threshold = bitflip_threshold;
266 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
267 mtd_bitflip_threshold_show,
268 mtd_bitflip_threshold_store);
270 static ssize_t mtd_ecc_step_size_show(struct device *dev,
271 struct device_attribute *attr, char *buf)
273 struct mtd_info *mtd = dev_get_drvdata(dev);
275 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
278 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
280 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
281 struct device_attribute *attr, char *buf)
283 struct mtd_info *mtd = dev_get_drvdata(dev);
284 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
286 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
288 static DEVICE_ATTR(corrected_bits, S_IRUGO,
289 mtd_ecc_stats_corrected_show, NULL);
291 static ssize_t mtd_ecc_stats_errors_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 snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
299 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
301 static ssize_t mtd_badblocks_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 snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
309 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
311 static ssize_t mtd_bbtblocks_show(struct device *dev,
312 struct device_attribute *attr, char *buf)
314 struct mtd_info *mtd = dev_get_drvdata(dev);
315 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
317 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
319 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
321 static struct attribute *mtd_attrs[] = {
323 &dev_attr_flags.attr,
325 &dev_attr_erasesize.attr,
326 &dev_attr_writesize.attr,
327 &dev_attr_subpagesize.attr,
328 &dev_attr_oobsize.attr,
329 &dev_attr_numeraseregions.attr,
331 &dev_attr_ecc_strength.attr,
332 &dev_attr_ecc_step_size.attr,
333 &dev_attr_corrected_bits.attr,
334 &dev_attr_ecc_failures.attr,
335 &dev_attr_bad_blocks.attr,
336 &dev_attr_bbt_blocks.attr,
337 &dev_attr_bitflip_threshold.attr,
340 ATTRIBUTE_GROUPS(mtd);
342 static struct device_type mtd_devtype = {
344 .groups = mtd_groups,
345 .release = mtd_release,
349 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
353 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
354 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
356 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
359 return NOMMU_MAP_COPY;
362 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
365 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
368 struct mtd_info *mtd;
370 mtd = container_of(n, struct mtd_info, reboot_notifier);
377 * add_mtd_device - register an MTD device
378 * @mtd: pointer to new MTD device info structure
380 * Add a device to the list of MTD devices present in the system, and
381 * notify each currently active MTD 'user' of its arrival. Returns
382 * zero on success or 1 on failure, which currently will only happen
383 * if there is insufficient memory or a sysfs error.
386 int add_mtd_device(struct mtd_info *mtd)
388 struct mtd_notifier *not;
391 mtd->backing_dev_info = &mtd_bdi;
393 BUG_ON(mtd->writesize == 0);
394 mutex_lock(&mtd_table_mutex);
396 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
403 /* default value if not set by driver */
404 if (mtd->bitflip_threshold == 0)
405 mtd->bitflip_threshold = mtd->ecc_strength;
407 if (is_power_of_2(mtd->erasesize))
408 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
410 mtd->erasesize_shift = 0;
412 if (is_power_of_2(mtd->writesize))
413 mtd->writesize_shift = ffs(mtd->writesize) - 1;
415 mtd->writesize_shift = 0;
417 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
418 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
420 /* Some chips always power up locked. Unlock them now */
421 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
422 error = mtd_unlock(mtd, 0, mtd->size);
423 if (error && error != -EOPNOTSUPP)
425 "%s: unlock failed, writes may not work\n",
429 /* Caller should have set dev.parent to match the
432 mtd->dev.type = &mtd_devtype;
433 mtd->dev.class = &mtd_class;
434 mtd->dev.devt = MTD_DEVT(i);
435 dev_set_name(&mtd->dev, "mtd%d", i);
436 dev_set_drvdata(&mtd->dev, mtd);
437 if (device_register(&mtd->dev) != 0)
440 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
443 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
444 /* No need to get a refcount on the module containing
445 the notifier, since we hold the mtd_table_mutex */
446 list_for_each_entry(not, &mtd_notifiers, list)
449 mutex_unlock(&mtd_table_mutex);
450 /* We _know_ we aren't being removed, because
451 our caller is still holding us here. So none
452 of this try_ nonsense, and no bitching about it
454 __module_get(THIS_MODULE);
458 idr_remove(&mtd_idr, i);
460 mutex_unlock(&mtd_table_mutex);
465 * del_mtd_device - unregister an MTD device
466 * @mtd: pointer to MTD device info structure
468 * Remove a device from the list of MTD devices present in the system,
469 * and notify each currently active MTD 'user' of its departure.
470 * Returns zero on success or 1 on failure, which currently will happen
471 * if the requested device does not appear to be present in the list.
474 int del_mtd_device(struct mtd_info *mtd)
477 struct mtd_notifier *not;
479 mutex_lock(&mtd_table_mutex);
481 if (idr_find(&mtd_idr, mtd->index) != mtd) {
486 /* No need to get a refcount on the module containing
487 the notifier, since we hold the mtd_table_mutex */
488 list_for_each_entry(not, &mtd_notifiers, list)
492 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
493 mtd->index, mtd->name, mtd->usecount);
496 device_unregister(&mtd->dev);
498 idr_remove(&mtd_idr, mtd->index);
500 module_put(THIS_MODULE);
505 mutex_unlock(&mtd_table_mutex);
509 static int mtd_add_device_partitions(struct mtd_info *mtd,
510 struct mtd_partition *real_parts,
515 if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
516 ret = add_mtd_device(mtd);
522 ret = add_mtd_partitions(mtd, real_parts, nbparts);
523 if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
533 * mtd_device_parse_register - parse partitions and register an MTD device.
535 * @mtd: the MTD device to register
536 * @types: the list of MTD partition probes to try, see
537 * 'parse_mtd_partitions()' for more information
538 * @parser_data: MTD partition parser-specific data
539 * @parts: fallback partition information to register, if parsing fails;
540 * only valid if %nr_parts > %0
541 * @nr_parts: the number of partitions in parts, if zero then the full
542 * MTD device is registered if no partition info is found
544 * This function aggregates MTD partitions parsing (done by
545 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
546 * basically follows the most common pattern found in many MTD drivers:
548 * * It first tries to probe partitions on MTD device @mtd using parsers
549 * specified in @types (if @types is %NULL, then the default list of parsers
550 * is used, see 'parse_mtd_partitions()' for more information). If none are
551 * found this functions tries to fallback to information specified in
553 * * If any partitioning info was found, this function registers the found
554 * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
555 * as a whole is registered first.
556 * * If no partitions were found this function just registers the MTD device
559 * Returns zero in case of success and a negative error code in case of failure.
561 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
562 struct mtd_part_parser_data *parser_data,
563 const struct mtd_partition *parts,
567 struct mtd_partition *real_parts = NULL;
569 ret = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
570 if (ret <= 0 && nr_parts && parts) {
571 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
580 ret = mtd_add_device_partitions(mtd, real_parts, ret);
583 * FIXME: some drivers unfortunately call this function more than once.
584 * So we have to check if we've already assigned the reboot notifier.
586 * Generally, we can make multiple calls work for most cases, but it
587 * does cause problems with parse_mtd_partitions() above (e.g.,
588 * cmdlineparts will register partitions more than once).
590 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
591 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
592 register_reboot_notifier(&mtd->reboot_notifier);
598 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
601 * mtd_device_unregister - unregister an existing MTD device.
603 * @master: the MTD device to unregister. This will unregister both the master
604 * and any partitions if registered.
606 int mtd_device_unregister(struct mtd_info *master)
611 unregister_reboot_notifier(&master->reboot_notifier);
613 err = del_mtd_partitions(master);
617 if (!device_is_registered(&master->dev))
620 return del_mtd_device(master);
622 EXPORT_SYMBOL_GPL(mtd_device_unregister);
625 * register_mtd_user - register a 'user' of MTD devices.
626 * @new: pointer to notifier info structure
628 * Registers a pair of callbacks function to be called upon addition
629 * or removal of MTD devices. Causes the 'add' callback to be immediately
630 * invoked for each MTD device currently present in the system.
632 void register_mtd_user (struct mtd_notifier *new)
634 struct mtd_info *mtd;
636 mutex_lock(&mtd_table_mutex);
638 list_add(&new->list, &mtd_notifiers);
640 __module_get(THIS_MODULE);
642 mtd_for_each_device(mtd)
645 mutex_unlock(&mtd_table_mutex);
647 EXPORT_SYMBOL_GPL(register_mtd_user);
650 * unregister_mtd_user - unregister a 'user' of MTD devices.
651 * @old: pointer to notifier info structure
653 * Removes a callback function pair from the list of 'users' to be
654 * notified upon addition or removal of MTD devices. Causes the
655 * 'remove' callback to be immediately invoked for each MTD device
656 * currently present in the system.
658 int unregister_mtd_user (struct mtd_notifier *old)
660 struct mtd_info *mtd;
662 mutex_lock(&mtd_table_mutex);
664 module_put(THIS_MODULE);
666 mtd_for_each_device(mtd)
669 list_del(&old->list);
670 mutex_unlock(&mtd_table_mutex);
673 EXPORT_SYMBOL_GPL(unregister_mtd_user);
676 * get_mtd_device - obtain a validated handle for an MTD device
677 * @mtd: last known address of the required MTD device
678 * @num: internal device number of the required MTD device
680 * Given a number and NULL address, return the num'th entry in the device
681 * table, if any. Given an address and num == -1, search the device table
682 * for a device with that address and return if it's still present. Given
683 * both, return the num'th driver only if its address matches. Return
686 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
688 struct mtd_info *ret = NULL, *other;
691 mutex_lock(&mtd_table_mutex);
694 mtd_for_each_device(other) {
700 } else if (num >= 0) {
701 ret = idr_find(&mtd_idr, num);
702 if (mtd && mtd != ret)
711 err = __get_mtd_device(ret);
715 mutex_unlock(&mtd_table_mutex);
718 EXPORT_SYMBOL_GPL(get_mtd_device);
721 int __get_mtd_device(struct mtd_info *mtd)
725 if (!try_module_get(mtd->owner))
728 if (mtd->_get_device) {
729 err = mtd->_get_device(mtd);
732 module_put(mtd->owner);
739 EXPORT_SYMBOL_GPL(__get_mtd_device);
742 * get_mtd_device_nm - obtain a validated handle for an MTD device by
744 * @name: MTD device name to open
746 * This function returns MTD device description structure in case of
747 * success and an error code in case of failure.
749 struct mtd_info *get_mtd_device_nm(const char *name)
752 struct mtd_info *mtd = NULL, *other;
754 mutex_lock(&mtd_table_mutex);
756 mtd_for_each_device(other) {
757 if (!strcmp(name, other->name)) {
766 err = __get_mtd_device(mtd);
770 mutex_unlock(&mtd_table_mutex);
774 mutex_unlock(&mtd_table_mutex);
777 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
779 void put_mtd_device(struct mtd_info *mtd)
781 mutex_lock(&mtd_table_mutex);
782 __put_mtd_device(mtd);
783 mutex_unlock(&mtd_table_mutex);
786 EXPORT_SYMBOL_GPL(put_mtd_device);
788 void __put_mtd_device(struct mtd_info *mtd)
791 BUG_ON(mtd->usecount < 0);
793 if (mtd->_put_device)
794 mtd->_put_device(mtd);
796 module_put(mtd->owner);
798 EXPORT_SYMBOL_GPL(__put_mtd_device);
801 * Erase is an asynchronous operation. Device drivers are supposed
802 * to call instr->callback() whenever the operation completes, even
803 * if it completes with a failure.
804 * Callers are supposed to pass a callback function and wait for it
805 * to be called before writing to the block.
807 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
809 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
811 if (!(mtd->flags & MTD_WRITEABLE))
813 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
815 instr->state = MTD_ERASE_DONE;
816 mtd_erase_callback(instr);
819 return mtd->_erase(mtd, instr);
821 EXPORT_SYMBOL_GPL(mtd_erase);
824 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
826 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
827 void **virt, resource_size_t *phys)
835 if (from < 0 || from >= mtd->size || len > mtd->size - from)
839 return mtd->_point(mtd, from, len, retlen, virt, phys);
841 EXPORT_SYMBOL_GPL(mtd_point);
843 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
844 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
848 if (from < 0 || from >= mtd->size || len > mtd->size - from)
852 return mtd->_unpoint(mtd, from, len);
854 EXPORT_SYMBOL_GPL(mtd_unpoint);
857 * Allow NOMMU mmap() to directly map the device (if not NULL)
858 * - return the address to which the offset maps
859 * - return -ENOSYS to indicate refusal to do the mapping
861 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
862 unsigned long offset, unsigned long flags)
864 if (!mtd->_get_unmapped_area)
866 if (offset >= mtd->size || len > mtd->size - offset)
868 return mtd->_get_unmapped_area(mtd, len, offset, flags);
870 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
872 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
877 if (from < 0 || from >= mtd->size || len > mtd->size - from)
883 * In the absence of an error, drivers return a non-negative integer
884 * representing the maximum number of bitflips that were corrected on
885 * any one ecc region (if applicable; zero otherwise).
887 ret_code = mtd->_read(mtd, from, len, retlen, buf);
888 if (unlikely(ret_code < 0))
890 if (mtd->ecc_strength == 0)
891 return 0; /* device lacks ecc */
892 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
894 EXPORT_SYMBOL_GPL(mtd_read);
896 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
900 if (to < 0 || to >= mtd->size || len > mtd->size - to)
902 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
906 return mtd->_write(mtd, to, len, retlen, buf);
908 EXPORT_SYMBOL_GPL(mtd_write);
911 * In blackbox flight recorder like scenarios we want to make successful writes
912 * in interrupt context. panic_write() is only intended to be called when its
913 * known the kernel is about to panic and we need the write to succeed. Since
914 * the kernel is not going to be running for much longer, this function can
915 * break locks and delay to ensure the write succeeds (but not sleep).
917 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
921 if (!mtd->_panic_write)
923 if (to < 0 || to >= mtd->size || len > mtd->size - to)
925 if (!(mtd->flags & MTD_WRITEABLE))
929 return mtd->_panic_write(mtd, to, len, retlen, buf);
931 EXPORT_SYMBOL_GPL(mtd_panic_write);
933 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
936 ops->retlen = ops->oobretlen = 0;
940 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
941 * similar to mtd->_read(), returning a non-negative integer
942 * representing max bitflips. In other cases, mtd->_read_oob() may
943 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
945 ret_code = mtd->_read_oob(mtd, from, ops);
946 if (unlikely(ret_code < 0))
948 if (mtd->ecc_strength == 0)
949 return 0; /* device lacks ecc */
950 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
952 EXPORT_SYMBOL_GPL(mtd_read_oob);
955 * Method to access the protection register area, present in some flash
956 * devices. The user data is one time programmable but the factory data is read
959 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
960 struct otp_info *buf)
962 if (!mtd->_get_fact_prot_info)
966 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
968 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
970 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
971 size_t *retlen, u_char *buf)
974 if (!mtd->_read_fact_prot_reg)
978 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
980 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
982 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
983 struct otp_info *buf)
985 if (!mtd->_get_user_prot_info)
989 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
991 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
993 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
994 size_t *retlen, u_char *buf)
997 if (!mtd->_read_user_prot_reg)
1001 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1003 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1005 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1006 size_t *retlen, u_char *buf)
1011 if (!mtd->_write_user_prot_reg)
1015 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1020 * If no data could be written at all, we are out of memory and
1021 * must return -ENOSPC.
1023 return (*retlen) ? 0 : -ENOSPC;
1025 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1027 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1029 if (!mtd->_lock_user_prot_reg)
1033 return mtd->_lock_user_prot_reg(mtd, from, len);
1035 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1037 /* Chip-supported device locking */
1038 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1042 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1046 return mtd->_lock(mtd, ofs, len);
1048 EXPORT_SYMBOL_GPL(mtd_lock);
1050 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1054 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1058 return mtd->_unlock(mtd, ofs, len);
1060 EXPORT_SYMBOL_GPL(mtd_unlock);
1062 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1064 if (!mtd->_is_locked)
1066 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1070 return mtd->_is_locked(mtd, ofs, len);
1072 EXPORT_SYMBOL_GPL(mtd_is_locked);
1074 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1076 if (ofs < 0 || ofs >= mtd->size)
1078 if (!mtd->_block_isreserved)
1080 return mtd->_block_isreserved(mtd, ofs);
1082 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1084 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1086 if (ofs < 0 || ofs >= mtd->size)
1088 if (!mtd->_block_isbad)
1090 return mtd->_block_isbad(mtd, ofs);
1092 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1094 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1096 if (!mtd->_block_markbad)
1098 if (ofs < 0 || ofs >= mtd->size)
1100 if (!(mtd->flags & MTD_WRITEABLE))
1102 return mtd->_block_markbad(mtd, ofs);
1104 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1107 * default_mtd_writev - the default writev method
1108 * @mtd: mtd device description object pointer
1109 * @vecs: the vectors to write
1110 * @count: count of vectors in @vecs
1111 * @to: the MTD device offset to write to
1112 * @retlen: on exit contains the count of bytes written to the MTD device.
1114 * This function returns zero in case of success and a negative error code in
1117 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1118 unsigned long count, loff_t to, size_t *retlen)
1121 size_t totlen = 0, thislen;
1124 for (i = 0; i < count; i++) {
1125 if (!vecs[i].iov_len)
1127 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1130 if (ret || thislen != vecs[i].iov_len)
1132 to += vecs[i].iov_len;
1139 * mtd_writev - the vector-based MTD write method
1140 * @mtd: mtd device description object pointer
1141 * @vecs: the vectors to write
1142 * @count: count of vectors in @vecs
1143 * @to: the MTD device offset to write to
1144 * @retlen: on exit contains the count of bytes written to the MTD device.
1146 * This function returns zero in case of success and a negative error code in
1149 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1150 unsigned long count, loff_t to, size_t *retlen)
1153 if (!(mtd->flags & MTD_WRITEABLE))
1156 return default_mtd_writev(mtd, vecs, count, to, retlen);
1157 return mtd->_writev(mtd, vecs, count, to, retlen);
1159 EXPORT_SYMBOL_GPL(mtd_writev);
1162 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1163 * @mtd: mtd device description object pointer
1164 * @size: a pointer to the ideal or maximum size of the allocation, points
1165 * to the actual allocation size on success.
1167 * This routine attempts to allocate a contiguous kernel buffer up to
1168 * the specified size, backing off the size of the request exponentially
1169 * until the request succeeds or until the allocation size falls below
1170 * the system page size. This attempts to make sure it does not adversely
1171 * impact system performance, so when allocating more than one page, we
1172 * ask the memory allocator to avoid re-trying, swapping, writing back
1173 * or performing I/O.
1175 * Note, this function also makes sure that the allocated buffer is aligned to
1176 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1178 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1179 * to handle smaller (i.e. degraded) buffer allocations under low- or
1180 * fragmented-memory situations where such reduced allocations, from a
1181 * requested ideal, are allowed.
1183 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1185 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1187 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
1188 __GFP_NORETRY | __GFP_NO_KSWAPD;
1189 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1192 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1194 while (*size > min_alloc) {
1195 kbuf = kmalloc(*size, flags);
1200 *size = ALIGN(*size, mtd->writesize);
1204 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1205 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1207 return kmalloc(*size, GFP_KERNEL);
1209 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1211 #ifdef CONFIG_PROC_FS
1213 /*====================================================================*/
1214 /* Support for /proc/mtd */
1216 static int mtd_proc_show(struct seq_file *m, void *v)
1218 struct mtd_info *mtd;
1220 seq_puts(m, "dev: size erasesize name\n");
1221 mutex_lock(&mtd_table_mutex);
1222 mtd_for_each_device(mtd) {
1223 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1224 mtd->index, (unsigned long long)mtd->size,
1225 mtd->erasesize, mtd->name);
1227 mutex_unlock(&mtd_table_mutex);
1231 static int mtd_proc_open(struct inode *inode, struct file *file)
1233 return single_open(file, mtd_proc_show, NULL);
1236 static const struct file_operations mtd_proc_ops = {
1237 .open = mtd_proc_open,
1239 .llseek = seq_lseek,
1240 .release = single_release,
1242 #endif /* CONFIG_PROC_FS */
1244 /*====================================================================*/
1247 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1251 ret = bdi_init(bdi);
1253 ret = bdi_register(bdi, NULL, "%s", name);
1261 static struct proc_dir_entry *proc_mtd;
1263 static int __init init_mtd(void)
1267 ret = class_register(&mtd_class);
1271 ret = mtd_bdi_init(&mtd_bdi, "mtd");
1275 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1277 ret = init_mtdchar();
1285 remove_proc_entry("mtd", NULL);
1287 class_unregister(&mtd_class);
1289 pr_err("Error registering mtd class or bdi: %d\n", ret);
1293 static void __exit cleanup_mtd(void)
1297 remove_proc_entry("mtd", NULL);
1298 class_unregister(&mtd_class);
1299 bdi_destroy(&mtd_bdi);
1302 module_init(init_mtd);
1303 module_exit(cleanup_mtd);
1305 MODULE_LICENSE("GPL");
1306 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1307 MODULE_DESCRIPTION("Core MTD registration and access routines");