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>
41 #include <linux/mtd/mtd.h>
42 #include <linux/mtd/partitions.h>
47 * backing device capabilities for non-mappable devices (such as NAND flash)
48 * - permits private mappings, copies are taken of the data
50 static struct backing_dev_info mtd_bdi_unmappable = {
51 .capabilities = BDI_CAP_MAP_COPY,
55 * backing device capabilities for R/O mappable devices (such as ROM)
56 * - permits private mappings, copies are taken of the data
57 * - permits non-writable shared mappings
59 static struct backing_dev_info mtd_bdi_ro_mappable = {
60 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
61 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
65 * backing device capabilities for writable mappable devices (such as RAM)
66 * - permits private mappings, copies are taken of the data
67 * - permits non-writable shared mappings
69 static struct backing_dev_info mtd_bdi_rw_mappable = {
70 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
71 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
75 static int mtd_cls_suspend(struct device *dev, pm_message_t state);
76 static int mtd_cls_resume(struct device *dev);
78 static struct class mtd_class = {
81 .suspend = mtd_cls_suspend,
82 .resume = mtd_cls_resume,
85 static DEFINE_IDR(mtd_idr);
87 /* These are exported solely for the purpose of mtd_blkdevs.c. You
88 should not use them for _anything_ else */
89 DEFINE_MUTEX(mtd_table_mutex);
90 EXPORT_SYMBOL_GPL(mtd_table_mutex);
92 struct mtd_info *__mtd_next_device(int i)
94 return idr_get_next(&mtd_idr, &i);
96 EXPORT_SYMBOL_GPL(__mtd_next_device);
98 static LIST_HEAD(mtd_notifiers);
101 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
103 /* REVISIT once MTD uses the driver model better, whoever allocates
104 * the mtd_info will probably want to use the release() hook...
106 static void mtd_release(struct device *dev)
108 struct mtd_info *mtd = dev_get_drvdata(dev);
109 dev_t index = MTD_DEVT(mtd->index);
111 /* remove /dev/mtdXro node */
112 device_destroy(&mtd_class, index + 1);
115 static int mtd_cls_suspend(struct device *dev, pm_message_t state)
117 struct mtd_info *mtd = dev_get_drvdata(dev);
119 return mtd ? mtd_suspend(mtd) : 0;
122 static int mtd_cls_resume(struct device *dev)
124 struct mtd_info *mtd = dev_get_drvdata(dev);
131 static ssize_t mtd_type_show(struct device *dev,
132 struct device_attribute *attr, char *buf)
134 struct mtd_info *mtd = dev_get_drvdata(dev);
159 case MTD_MLCNANDFLASH:
166 return snprintf(buf, PAGE_SIZE, "%s\n", type);
168 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
170 static ssize_t mtd_flags_show(struct device *dev,
171 struct device_attribute *attr, char *buf)
173 struct mtd_info *mtd = dev_get_drvdata(dev);
175 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
178 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
180 static ssize_t mtd_size_show(struct device *dev,
181 struct device_attribute *attr, char *buf)
183 struct mtd_info *mtd = dev_get_drvdata(dev);
185 return snprintf(buf, PAGE_SIZE, "%llu\n",
186 (unsigned long long)mtd->size);
189 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
191 static ssize_t mtd_erasesize_show(struct device *dev,
192 struct device_attribute *attr, char *buf)
194 struct mtd_info *mtd = dev_get_drvdata(dev);
196 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
199 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
201 static ssize_t mtd_writesize_show(struct device *dev,
202 struct device_attribute *attr, char *buf)
204 struct mtd_info *mtd = dev_get_drvdata(dev);
206 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
209 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
211 static ssize_t mtd_subpagesize_show(struct device *dev,
212 struct device_attribute *attr, char *buf)
214 struct mtd_info *mtd = dev_get_drvdata(dev);
215 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
217 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
220 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
222 static ssize_t mtd_oobsize_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
225 struct mtd_info *mtd = dev_get_drvdata(dev);
227 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
230 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
232 static ssize_t mtd_numeraseregions_show(struct device *dev,
233 struct device_attribute *attr, char *buf)
235 struct mtd_info *mtd = dev_get_drvdata(dev);
237 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
240 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
243 static ssize_t mtd_name_show(struct device *dev,
244 struct device_attribute *attr, char *buf)
246 struct mtd_info *mtd = dev_get_drvdata(dev);
248 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
251 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
253 static ssize_t mtd_ecc_strength_show(struct device *dev,
254 struct device_attribute *attr, char *buf)
256 struct mtd_info *mtd = dev_get_drvdata(dev);
258 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
260 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
262 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
263 struct device_attribute *attr,
266 struct mtd_info *mtd = dev_get_drvdata(dev);
268 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
271 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
272 struct device_attribute *attr,
273 const char *buf, size_t count)
275 struct mtd_info *mtd = dev_get_drvdata(dev);
276 unsigned int bitflip_threshold;
279 retval = kstrtouint(buf, 0, &bitflip_threshold);
283 mtd->bitflip_threshold = bitflip_threshold;
286 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
287 mtd_bitflip_threshold_show,
288 mtd_bitflip_threshold_store);
290 static ssize_t mtd_ecc_step_size_show(struct device *dev,
291 struct device_attribute *attr, char *buf)
293 struct mtd_info *mtd = dev_get_drvdata(dev);
295 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
298 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
300 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
301 struct device_attribute *attr, char *buf)
303 struct mtd_info *mtd = dev_get_drvdata(dev);
304 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
306 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
308 static DEVICE_ATTR(corrected_bits, S_IRUGO,
309 mtd_ecc_stats_corrected_show, NULL);
311 static ssize_t mtd_ecc_stats_errors_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->failed);
319 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
321 static ssize_t mtd_badblocks_show(struct device *dev,
322 struct device_attribute *attr, char *buf)
324 struct mtd_info *mtd = dev_get_drvdata(dev);
325 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
327 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
329 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
331 static ssize_t mtd_bbtblocks_show(struct device *dev,
332 struct device_attribute *attr, char *buf)
334 struct mtd_info *mtd = dev_get_drvdata(dev);
335 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
337 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
339 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
341 static struct attribute *mtd_attrs[] = {
343 &dev_attr_flags.attr,
345 &dev_attr_erasesize.attr,
346 &dev_attr_writesize.attr,
347 &dev_attr_subpagesize.attr,
348 &dev_attr_oobsize.attr,
349 &dev_attr_numeraseregions.attr,
351 &dev_attr_ecc_strength.attr,
352 &dev_attr_ecc_step_size.attr,
353 &dev_attr_corrected_bits.attr,
354 &dev_attr_ecc_failures.attr,
355 &dev_attr_bad_blocks.attr,
356 &dev_attr_bbt_blocks.attr,
357 &dev_attr_bitflip_threshold.attr,
360 ATTRIBUTE_GROUPS(mtd);
362 static struct device_type mtd_devtype = {
364 .groups = mtd_groups,
365 .release = mtd_release,
369 * add_mtd_device - register an MTD device
370 * @mtd: pointer to new MTD device info structure
372 * Add a device to the list of MTD devices present in the system, and
373 * notify each currently active MTD 'user' of its arrival. Returns
374 * zero on success or 1 on failure, which currently will only happen
375 * if there is insufficient memory or a sysfs error.
378 int add_mtd_device(struct mtd_info *mtd)
380 struct mtd_notifier *not;
383 if (!mtd->backing_dev_info) {
386 mtd->backing_dev_info = &mtd_bdi_rw_mappable;
389 mtd->backing_dev_info = &mtd_bdi_ro_mappable;
392 mtd->backing_dev_info = &mtd_bdi_unmappable;
397 BUG_ON(mtd->writesize == 0);
398 mutex_lock(&mtd_table_mutex);
400 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
407 /* default value if not set by driver */
408 if (mtd->bitflip_threshold == 0)
409 mtd->bitflip_threshold = mtd->ecc_strength;
411 if (is_power_of_2(mtd->erasesize))
412 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
414 mtd->erasesize_shift = 0;
416 if (is_power_of_2(mtd->writesize))
417 mtd->writesize_shift = ffs(mtd->writesize) - 1;
419 mtd->writesize_shift = 0;
421 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
422 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
424 /* Some chips always power up locked. Unlock them now */
425 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
426 error = mtd_unlock(mtd, 0, mtd->size);
427 if (error && error != -EOPNOTSUPP)
429 "%s: unlock failed, writes may not work\n",
433 /* Caller should have set dev.parent to match the
436 mtd->dev.type = &mtd_devtype;
437 mtd->dev.class = &mtd_class;
438 mtd->dev.devt = MTD_DEVT(i);
439 dev_set_name(&mtd->dev, "mtd%d", i);
440 dev_set_drvdata(&mtd->dev, mtd);
441 if (device_register(&mtd->dev) != 0)
444 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
447 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
448 /* No need to get a refcount on the module containing
449 the notifier, since we hold the mtd_table_mutex */
450 list_for_each_entry(not, &mtd_notifiers, list)
453 mutex_unlock(&mtd_table_mutex);
454 /* We _know_ we aren't being removed, because
455 our caller is still holding us here. So none
456 of this try_ nonsense, and no bitching about it
458 __module_get(THIS_MODULE);
462 idr_remove(&mtd_idr, i);
464 mutex_unlock(&mtd_table_mutex);
469 * del_mtd_device - unregister an MTD device
470 * @mtd: pointer to MTD device info structure
472 * Remove a device from the list of MTD devices present in the system,
473 * and notify each currently active MTD 'user' of its departure.
474 * Returns zero on success or 1 on failure, which currently will happen
475 * if the requested device does not appear to be present in the list.
478 int del_mtd_device(struct mtd_info *mtd)
481 struct mtd_notifier *not;
483 mutex_lock(&mtd_table_mutex);
485 if (idr_find(&mtd_idr, mtd->index) != mtd) {
490 /* No need to get a refcount on the module containing
491 the notifier, since we hold the mtd_table_mutex */
492 list_for_each_entry(not, &mtd_notifiers, list)
496 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
497 mtd->index, mtd->name, mtd->usecount);
500 device_unregister(&mtd->dev);
502 idr_remove(&mtd_idr, mtd->index);
504 module_put(THIS_MODULE);
509 mutex_unlock(&mtd_table_mutex);
514 * mtd_device_parse_register - parse partitions and register an MTD device.
516 * @mtd: the MTD device to register
517 * @types: the list of MTD partition probes to try, see
518 * 'parse_mtd_partitions()' for more information
519 * @parser_data: MTD partition parser-specific data
520 * @parts: fallback partition information to register, if parsing fails;
521 * only valid if %nr_parts > %0
522 * @nr_parts: the number of partitions in parts, if zero then the full
523 * MTD device is registered if no partition info is found
525 * This function aggregates MTD partitions parsing (done by
526 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
527 * basically follows the most common pattern found in many MTD drivers:
529 * * It first tries to probe partitions on MTD device @mtd using parsers
530 * specified in @types (if @types is %NULL, then the default list of parsers
531 * is used, see 'parse_mtd_partitions()' for more information). If none are
532 * found this functions tries to fallback to information specified in
534 * * If any partitioning info was found, this function registers the found
536 * * If no partitions were found this function just registers the MTD device
539 * Returns zero in case of success and a negative error code in case of failure.
541 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
542 struct mtd_part_parser_data *parser_data,
543 const struct mtd_partition *parts,
547 struct mtd_partition *real_parts;
549 err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
550 if (err <= 0 && nr_parts && parts) {
551 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
560 err = add_mtd_partitions(mtd, real_parts, err);
562 } else if (err == 0) {
563 err = add_mtd_device(mtd);
570 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
573 * mtd_device_unregister - unregister an existing MTD device.
575 * @master: the MTD device to unregister. This will unregister both the master
576 * and any partitions if registered.
578 int mtd_device_unregister(struct mtd_info *master)
582 err = del_mtd_partitions(master);
586 if (!device_is_registered(&master->dev))
589 return del_mtd_device(master);
591 EXPORT_SYMBOL_GPL(mtd_device_unregister);
594 * register_mtd_user - register a 'user' of MTD devices.
595 * @new: pointer to notifier info structure
597 * Registers a pair of callbacks function to be called upon addition
598 * or removal of MTD devices. Causes the 'add' callback to be immediately
599 * invoked for each MTD device currently present in the system.
601 void register_mtd_user (struct mtd_notifier *new)
603 struct mtd_info *mtd;
605 mutex_lock(&mtd_table_mutex);
607 list_add(&new->list, &mtd_notifiers);
609 __module_get(THIS_MODULE);
611 mtd_for_each_device(mtd)
614 mutex_unlock(&mtd_table_mutex);
616 EXPORT_SYMBOL_GPL(register_mtd_user);
619 * unregister_mtd_user - unregister a 'user' of MTD devices.
620 * @old: pointer to notifier info structure
622 * Removes a callback function pair from the list of 'users' to be
623 * notified upon addition or removal of MTD devices. Causes the
624 * 'remove' callback to be immediately invoked for each MTD device
625 * currently present in the system.
627 int unregister_mtd_user (struct mtd_notifier *old)
629 struct mtd_info *mtd;
631 mutex_lock(&mtd_table_mutex);
633 module_put(THIS_MODULE);
635 mtd_for_each_device(mtd)
638 list_del(&old->list);
639 mutex_unlock(&mtd_table_mutex);
642 EXPORT_SYMBOL_GPL(unregister_mtd_user);
645 * get_mtd_device - obtain a validated handle for an MTD device
646 * @mtd: last known address of the required MTD device
647 * @num: internal device number of the required MTD device
649 * Given a number and NULL address, return the num'th entry in the device
650 * table, if any. Given an address and num == -1, search the device table
651 * for a device with that address and return if it's still present. Given
652 * both, return the num'th driver only if its address matches. Return
655 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
657 struct mtd_info *ret = NULL, *other;
660 mutex_lock(&mtd_table_mutex);
663 mtd_for_each_device(other) {
669 } else if (num >= 0) {
670 ret = idr_find(&mtd_idr, num);
671 if (mtd && mtd != ret)
680 err = __get_mtd_device(ret);
684 mutex_unlock(&mtd_table_mutex);
687 EXPORT_SYMBOL_GPL(get_mtd_device);
690 int __get_mtd_device(struct mtd_info *mtd)
694 if (!try_module_get(mtd->owner))
697 if (mtd->_get_device) {
698 err = mtd->_get_device(mtd);
701 module_put(mtd->owner);
708 EXPORT_SYMBOL_GPL(__get_mtd_device);
711 * get_mtd_device_nm - obtain a validated handle for an MTD device by
713 * @name: MTD device name to open
715 * This function returns MTD device description structure in case of
716 * success and an error code in case of failure.
718 struct mtd_info *get_mtd_device_nm(const char *name)
721 struct mtd_info *mtd = NULL, *other;
723 mutex_lock(&mtd_table_mutex);
725 mtd_for_each_device(other) {
726 if (!strcmp(name, other->name)) {
735 err = __get_mtd_device(mtd);
739 mutex_unlock(&mtd_table_mutex);
743 mutex_unlock(&mtd_table_mutex);
746 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
748 void put_mtd_device(struct mtd_info *mtd)
750 mutex_lock(&mtd_table_mutex);
751 __put_mtd_device(mtd);
752 mutex_unlock(&mtd_table_mutex);
755 EXPORT_SYMBOL_GPL(put_mtd_device);
757 void __put_mtd_device(struct mtd_info *mtd)
760 BUG_ON(mtd->usecount < 0);
762 if (mtd->_put_device)
763 mtd->_put_device(mtd);
765 module_put(mtd->owner);
767 EXPORT_SYMBOL_GPL(__put_mtd_device);
770 * Erase is an asynchronous operation. Device drivers are supposed
771 * to call instr->callback() whenever the operation completes, even
772 * if it completes with a failure.
773 * Callers are supposed to pass a callback function and wait for it
774 * to be called before writing to the block.
776 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
778 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
780 if (!(mtd->flags & MTD_WRITEABLE))
782 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
784 instr->state = MTD_ERASE_DONE;
785 mtd_erase_callback(instr);
788 return mtd->_erase(mtd, instr);
790 EXPORT_SYMBOL_GPL(mtd_erase);
793 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
795 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
796 void **virt, resource_size_t *phys)
804 if (from < 0 || from >= mtd->size || len > mtd->size - from)
808 return mtd->_point(mtd, from, len, retlen, virt, phys);
810 EXPORT_SYMBOL_GPL(mtd_point);
812 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
813 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
817 if (from < 0 || from >= mtd->size || len > mtd->size - from)
821 return mtd->_unpoint(mtd, from, len);
823 EXPORT_SYMBOL_GPL(mtd_unpoint);
826 * Allow NOMMU mmap() to directly map the device (if not NULL)
827 * - return the address to which the offset maps
828 * - return -ENOSYS to indicate refusal to do the mapping
830 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
831 unsigned long offset, unsigned long flags)
833 if (!mtd->_get_unmapped_area)
835 if (offset >= mtd->size || len > mtd->size - offset)
837 return mtd->_get_unmapped_area(mtd, len, offset, flags);
839 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
841 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
846 if (from < 0 || from >= mtd->size || len > mtd->size - from)
852 * In the absence of an error, drivers return a non-negative integer
853 * representing the maximum number of bitflips that were corrected on
854 * any one ecc region (if applicable; zero otherwise).
856 ret_code = mtd->_read(mtd, from, len, retlen, buf);
857 if (unlikely(ret_code < 0))
859 if (mtd->ecc_strength == 0)
860 return 0; /* device lacks ecc */
861 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
863 EXPORT_SYMBOL_GPL(mtd_read);
865 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
869 if (to < 0 || to >= mtd->size || len > mtd->size - to)
871 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
875 return mtd->_write(mtd, to, len, retlen, buf);
877 EXPORT_SYMBOL_GPL(mtd_write);
880 * In blackbox flight recorder like scenarios we want to make successful writes
881 * in interrupt context. panic_write() is only intended to be called when its
882 * known the kernel is about to panic and we need the write to succeed. Since
883 * the kernel is not going to be running for much longer, this function can
884 * break locks and delay to ensure the write succeeds (but not sleep).
886 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
890 if (!mtd->_panic_write)
892 if (to < 0 || to >= mtd->size || len > mtd->size - to)
894 if (!(mtd->flags & MTD_WRITEABLE))
898 return mtd->_panic_write(mtd, to, len, retlen, buf);
900 EXPORT_SYMBOL_GPL(mtd_panic_write);
902 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
905 ops->retlen = ops->oobretlen = 0;
909 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
910 * similar to mtd->_read(), returning a non-negative integer
911 * representing max bitflips. In other cases, mtd->_read_oob() may
912 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
914 ret_code = mtd->_read_oob(mtd, from, ops);
915 if (unlikely(ret_code < 0))
917 if (mtd->ecc_strength == 0)
918 return 0; /* device lacks ecc */
919 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
921 EXPORT_SYMBOL_GPL(mtd_read_oob);
924 * Method to access the protection register area, present in some flash
925 * devices. The user data is one time programmable but the factory data is read
928 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
929 struct otp_info *buf)
931 if (!mtd->_get_fact_prot_info)
935 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
937 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
939 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
940 size_t *retlen, u_char *buf)
943 if (!mtd->_read_fact_prot_reg)
947 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
949 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
951 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
952 struct otp_info *buf)
954 if (!mtd->_get_user_prot_info)
958 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
960 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
962 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
963 size_t *retlen, u_char *buf)
966 if (!mtd->_read_user_prot_reg)
970 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
972 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
974 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
975 size_t *retlen, u_char *buf)
980 if (!mtd->_write_user_prot_reg)
984 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
989 * If no data could be written at all, we are out of memory and
990 * must return -ENOSPC.
992 return (*retlen) ? 0 : -ENOSPC;
994 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
996 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
998 if (!mtd->_lock_user_prot_reg)
1002 return mtd->_lock_user_prot_reg(mtd, from, len);
1004 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1006 /* Chip-supported device locking */
1007 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1011 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1015 return mtd->_lock(mtd, ofs, len);
1017 EXPORT_SYMBOL_GPL(mtd_lock);
1019 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1023 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1027 return mtd->_unlock(mtd, ofs, len);
1029 EXPORT_SYMBOL_GPL(mtd_unlock);
1031 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1033 if (!mtd->_is_locked)
1035 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1039 return mtd->_is_locked(mtd, ofs, len);
1041 EXPORT_SYMBOL_GPL(mtd_is_locked);
1043 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1045 if (ofs < 0 || ofs >= mtd->size)
1047 if (!mtd->_block_isreserved)
1049 return mtd->_block_isreserved(mtd, ofs);
1051 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1053 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1055 if (ofs < 0 || ofs >= mtd->size)
1057 if (!mtd->_block_isbad)
1059 return mtd->_block_isbad(mtd, ofs);
1061 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1063 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1065 if (!mtd->_block_markbad)
1067 if (ofs < 0 || ofs >= mtd->size)
1069 if (!(mtd->flags & MTD_WRITEABLE))
1071 return mtd->_block_markbad(mtd, ofs);
1073 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1076 * default_mtd_writev - the default writev method
1077 * @mtd: mtd device description object pointer
1078 * @vecs: the vectors to write
1079 * @count: count of vectors in @vecs
1080 * @to: the MTD device offset to write to
1081 * @retlen: on exit contains the count of bytes written to the MTD device.
1083 * This function returns zero in case of success and a negative error code in
1086 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1087 unsigned long count, loff_t to, size_t *retlen)
1090 size_t totlen = 0, thislen;
1093 for (i = 0; i < count; i++) {
1094 if (!vecs[i].iov_len)
1096 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1099 if (ret || thislen != vecs[i].iov_len)
1101 to += vecs[i].iov_len;
1108 * mtd_writev - the vector-based MTD write method
1109 * @mtd: mtd device description object pointer
1110 * @vecs: the vectors to write
1111 * @count: count of vectors in @vecs
1112 * @to: the MTD device offset to write to
1113 * @retlen: on exit contains the count of bytes written to the MTD device.
1115 * This function returns zero in case of success and a negative error code in
1118 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1119 unsigned long count, loff_t to, size_t *retlen)
1122 if (!(mtd->flags & MTD_WRITEABLE))
1125 return default_mtd_writev(mtd, vecs, count, to, retlen);
1126 return mtd->_writev(mtd, vecs, count, to, retlen);
1128 EXPORT_SYMBOL_GPL(mtd_writev);
1131 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1132 * @mtd: mtd device description object pointer
1133 * @size: a pointer to the ideal or maximum size of the allocation, points
1134 * to the actual allocation size on success.
1136 * This routine attempts to allocate a contiguous kernel buffer up to
1137 * the specified size, backing off the size of the request exponentially
1138 * until the request succeeds or until the allocation size falls below
1139 * the system page size. This attempts to make sure it does not adversely
1140 * impact system performance, so when allocating more than one page, we
1141 * ask the memory allocator to avoid re-trying, swapping, writing back
1142 * or performing I/O.
1144 * Note, this function also makes sure that the allocated buffer is aligned to
1145 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1147 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1148 * to handle smaller (i.e. degraded) buffer allocations under low- or
1149 * fragmented-memory situations where such reduced allocations, from a
1150 * requested ideal, are allowed.
1152 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1154 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1156 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
1157 __GFP_NORETRY | __GFP_NO_KSWAPD;
1158 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1161 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1163 while (*size > min_alloc) {
1164 kbuf = kmalloc(*size, flags);
1169 *size = ALIGN(*size, mtd->writesize);
1173 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1174 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1176 return kmalloc(*size, GFP_KERNEL);
1178 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1180 #ifdef CONFIG_PROC_FS
1182 /*====================================================================*/
1183 /* Support for /proc/mtd */
1185 static int mtd_proc_show(struct seq_file *m, void *v)
1187 struct mtd_info *mtd;
1189 seq_puts(m, "dev: size erasesize name\n");
1190 mutex_lock(&mtd_table_mutex);
1191 mtd_for_each_device(mtd) {
1192 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1193 mtd->index, (unsigned long long)mtd->size,
1194 mtd->erasesize, mtd->name);
1196 mutex_unlock(&mtd_table_mutex);
1200 static int mtd_proc_open(struct inode *inode, struct file *file)
1202 return single_open(file, mtd_proc_show, NULL);
1205 static const struct file_operations mtd_proc_ops = {
1206 .open = mtd_proc_open,
1208 .llseek = seq_lseek,
1209 .release = single_release,
1211 #endif /* CONFIG_PROC_FS */
1213 /*====================================================================*/
1216 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1220 ret = bdi_init(bdi);
1222 ret = bdi_register(bdi, NULL, "%s", name);
1230 static struct proc_dir_entry *proc_mtd;
1232 static int __init init_mtd(void)
1236 ret = class_register(&mtd_class);
1240 ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
1244 ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
1248 ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
1252 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1254 ret = init_mtdchar();
1262 remove_proc_entry("mtd", NULL);
1264 bdi_destroy(&mtd_bdi_ro_mappable);
1266 bdi_destroy(&mtd_bdi_unmappable);
1268 class_unregister(&mtd_class);
1270 pr_err("Error registering mtd class or bdi: %d\n", ret);
1274 static void __exit cleanup_mtd(void)
1278 remove_proc_entry("mtd", NULL);
1279 class_unregister(&mtd_class);
1280 bdi_destroy(&mtd_bdi_unmappable);
1281 bdi_destroy(&mtd_bdi_ro_mappable);
1282 bdi_destroy(&mtd_bdi_rw_mappable);
1285 module_init(init_mtd);
1286 module_exit(cleanup_mtd);
1288 MODULE_LICENSE("GPL");
1289 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1290 MODULE_DESCRIPTION("Core MTD registration and access routines");