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>
36 #include <linux/proc_fs.h>
37 #include <linux/idr.h>
38 #include <linux/backing-dev.h>
39 #include <linux/gfp.h>
40 #include <linux/slab.h>
41 #include <linux/reboot.h>
42 #include <linux/kconfig.h>
44 #include <linux/mtd/mtd.h>
45 #include <linux/mtd/partitions.h>
49 static struct backing_dev_info mtd_bdi = {
52 #ifdef CONFIG_PM_SLEEP
54 static int mtd_cls_suspend(struct device *dev)
56 struct mtd_info *mtd = dev_get_drvdata(dev);
58 return mtd ? mtd_suspend(mtd) : 0;
61 static int mtd_cls_resume(struct device *dev)
63 struct mtd_info *mtd = dev_get_drvdata(dev);
70 static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
71 #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
73 #define MTD_CLS_PM_OPS NULL
76 static struct class mtd_class = {
82 static DEFINE_IDR(mtd_idr);
84 /* These are exported solely for the purpose of mtd_blkdevs.c. You
85 should not use them for _anything_ else */
86 DEFINE_MUTEX(mtd_table_mutex);
87 EXPORT_SYMBOL_GPL(mtd_table_mutex);
89 struct mtd_info *__mtd_next_device(int i)
91 return idr_get_next(&mtd_idr, &i);
93 EXPORT_SYMBOL_GPL(__mtd_next_device);
95 static LIST_HEAD(mtd_notifiers);
98 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
100 /* REVISIT once MTD uses the driver model better, whoever allocates
101 * the mtd_info will probably want to use the release() hook...
103 static void mtd_release(struct device *dev)
105 struct mtd_info *mtd = dev_get_drvdata(dev);
106 dev_t index = MTD_DEVT(mtd->index);
108 /* remove /dev/mtdXro node */
109 device_destroy(&mtd_class, index + 1);
112 static ssize_t mtd_type_show(struct device *dev,
113 struct device_attribute *attr, char *buf)
115 struct mtd_info *mtd = dev_get_drvdata(dev);
140 case MTD_MLCNANDFLASH:
147 return snprintf(buf, PAGE_SIZE, "%s\n", type);
149 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
151 static ssize_t mtd_flags_show(struct device *dev,
152 struct device_attribute *attr, char *buf)
154 struct mtd_info *mtd = dev_get_drvdata(dev);
156 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
159 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
161 static ssize_t mtd_size_show(struct device *dev,
162 struct device_attribute *attr, char *buf)
164 struct mtd_info *mtd = dev_get_drvdata(dev);
166 return snprintf(buf, PAGE_SIZE, "%llu\n",
167 (unsigned long long)mtd->size);
170 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
172 static ssize_t mtd_erasesize_show(struct device *dev,
173 struct device_attribute *attr, char *buf)
175 struct mtd_info *mtd = dev_get_drvdata(dev);
177 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
180 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
182 static ssize_t mtd_writesize_show(struct device *dev,
183 struct device_attribute *attr, char *buf)
185 struct mtd_info *mtd = dev_get_drvdata(dev);
187 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
190 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
192 static ssize_t mtd_subpagesize_show(struct device *dev,
193 struct device_attribute *attr, char *buf)
195 struct mtd_info *mtd = dev_get_drvdata(dev);
196 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
198 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
201 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
203 static ssize_t mtd_oobsize_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
206 struct mtd_info *mtd = dev_get_drvdata(dev);
208 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
211 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
213 static ssize_t mtd_numeraseregions_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
216 struct mtd_info *mtd = dev_get_drvdata(dev);
218 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
221 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
224 static ssize_t mtd_name_show(struct device *dev,
225 struct device_attribute *attr, char *buf)
227 struct mtd_info *mtd = dev_get_drvdata(dev);
229 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
232 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
234 static ssize_t mtd_ecc_strength_show(struct device *dev,
235 struct device_attribute *attr, char *buf)
237 struct mtd_info *mtd = dev_get_drvdata(dev);
239 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
241 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
243 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
244 struct device_attribute *attr,
247 struct mtd_info *mtd = dev_get_drvdata(dev);
249 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
252 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
253 struct device_attribute *attr,
254 const char *buf, size_t count)
256 struct mtd_info *mtd = dev_get_drvdata(dev);
257 unsigned int bitflip_threshold;
260 retval = kstrtouint(buf, 0, &bitflip_threshold);
264 mtd->bitflip_threshold = bitflip_threshold;
267 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
268 mtd_bitflip_threshold_show,
269 mtd_bitflip_threshold_store);
271 static ssize_t mtd_ecc_step_size_show(struct device *dev,
272 struct device_attribute *attr, char *buf)
274 struct mtd_info *mtd = dev_get_drvdata(dev);
276 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
279 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
281 static ssize_t mtd_ecc_stats_corrected_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 snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
289 static DEVICE_ATTR(corrected_bits, S_IRUGO,
290 mtd_ecc_stats_corrected_show, NULL);
292 static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
293 struct device_attribute *attr, char *buf)
295 struct mtd_info *mtd = dev_get_drvdata(dev);
296 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
298 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
300 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
302 static ssize_t mtd_badblocks_show(struct device *dev,
303 struct device_attribute *attr, char *buf)
305 struct mtd_info *mtd = dev_get_drvdata(dev);
306 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
308 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
310 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
312 static ssize_t mtd_bbtblocks_show(struct device *dev,
313 struct device_attribute *attr, char *buf)
315 struct mtd_info *mtd = dev_get_drvdata(dev);
316 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
318 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
320 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
322 static struct attribute *mtd_attrs[] = {
324 &dev_attr_flags.attr,
326 &dev_attr_erasesize.attr,
327 &dev_attr_writesize.attr,
328 &dev_attr_subpagesize.attr,
329 &dev_attr_oobsize.attr,
330 &dev_attr_numeraseregions.attr,
332 &dev_attr_ecc_strength.attr,
333 &dev_attr_ecc_step_size.attr,
334 &dev_attr_corrected_bits.attr,
335 &dev_attr_ecc_failures.attr,
336 &dev_attr_bad_blocks.attr,
337 &dev_attr_bbt_blocks.attr,
338 &dev_attr_bitflip_threshold.attr,
341 ATTRIBUTE_GROUPS(mtd);
343 static struct device_type mtd_devtype = {
345 .groups = mtd_groups,
346 .release = mtd_release,
350 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
354 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
355 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
357 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
360 return NOMMU_MAP_COPY;
363 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
366 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
369 struct mtd_info *mtd;
371 mtd = container_of(n, struct mtd_info, reboot_notifier);
378 * add_mtd_device - register an MTD device
379 * @mtd: pointer to new MTD device info structure
381 * Add a device to the list of MTD devices present in the system, and
382 * notify each currently active MTD 'user' of its arrival. Returns
383 * zero on success or non-zero on failure.
386 int add_mtd_device(struct mtd_info *mtd)
388 struct mtd_notifier *not;
392 * May occur, for instance, on buggy drivers which call
393 * mtd_device_parse_register() multiple times on the same master MTD,
394 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
396 if (WARN_ONCE(mtd->backing_dev_info, "MTD already registered\n"))
399 mtd->backing_dev_info = &mtd_bdi;
401 BUG_ON(mtd->writesize == 0);
402 mutex_lock(&mtd_table_mutex);
404 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
413 /* default value if not set by driver */
414 if (mtd->bitflip_threshold == 0)
415 mtd->bitflip_threshold = mtd->ecc_strength;
417 if (is_power_of_2(mtd->erasesize))
418 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
420 mtd->erasesize_shift = 0;
422 if (is_power_of_2(mtd->writesize))
423 mtd->writesize_shift = ffs(mtd->writesize) - 1;
425 mtd->writesize_shift = 0;
427 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
428 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
430 if (mtd->dev.parent) {
431 if (!mtd->owner && mtd->dev.parent->driver)
432 mtd->owner = mtd->dev.parent->driver->owner;
434 mtd->name = dev_name(mtd->dev.parent);
436 pr_debug("mtd device won't show a device symlink in sysfs\n");
439 /* Some chips always power up locked. Unlock them now */
440 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
441 error = mtd_unlock(mtd, 0, mtd->size);
442 if (error && error != -EOPNOTSUPP)
444 "%s: unlock failed, writes may not work\n",
446 /* Ignore unlock failures? */
450 /* Caller should have set dev.parent to match the
451 * physical device, if appropriate.
453 mtd->dev.type = &mtd_devtype;
454 mtd->dev.class = &mtd_class;
455 mtd->dev.devt = MTD_DEVT(i);
456 dev_set_name(&mtd->dev, "mtd%d", i);
457 dev_set_drvdata(&mtd->dev, mtd);
458 of_node_get(mtd_get_of_node(mtd));
459 error = device_register(&mtd->dev);
463 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
466 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
467 /* No need to get a refcount on the module containing
468 the notifier, since we hold the mtd_table_mutex */
469 list_for_each_entry(not, &mtd_notifiers, list)
472 mutex_unlock(&mtd_table_mutex);
473 /* We _know_ we aren't being removed, because
474 our caller is still holding us here. So none
475 of this try_ nonsense, and no bitching about it
477 __module_get(THIS_MODULE);
481 of_node_put(mtd_get_of_node(mtd));
482 idr_remove(&mtd_idr, i);
484 mutex_unlock(&mtd_table_mutex);
489 * del_mtd_device - unregister an MTD device
490 * @mtd: pointer to MTD device info structure
492 * Remove a device from the list of MTD devices present in the system,
493 * and notify each currently active MTD 'user' of its departure.
494 * Returns zero on success or 1 on failure, which currently will happen
495 * if the requested device does not appear to be present in the list.
498 int del_mtd_device(struct mtd_info *mtd)
501 struct mtd_notifier *not;
503 mutex_lock(&mtd_table_mutex);
505 if (idr_find(&mtd_idr, mtd->index) != mtd) {
510 /* No need to get a refcount on the module containing
511 the notifier, since we hold the mtd_table_mutex */
512 list_for_each_entry(not, &mtd_notifiers, list)
516 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
517 mtd->index, mtd->name, mtd->usecount);
520 device_unregister(&mtd->dev);
522 idr_remove(&mtd_idr, mtd->index);
523 of_node_put(mtd_get_of_node(mtd));
525 module_put(THIS_MODULE);
530 mutex_unlock(&mtd_table_mutex);
534 static int mtd_add_device_partitions(struct mtd_info *mtd,
535 struct mtd_partitions *parts)
537 const struct mtd_partition *real_parts = parts->parts;
538 int nbparts = parts->nr_parts;
541 if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
542 ret = add_mtd_device(mtd);
548 ret = add_mtd_partitions(mtd, real_parts, nbparts);
549 if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
559 * mtd_device_parse_register - parse partitions and register an MTD device.
561 * @mtd: the MTD device to register
562 * @types: the list of MTD partition probes to try, see
563 * 'parse_mtd_partitions()' for more information
564 * @parser_data: MTD partition parser-specific data
565 * @parts: fallback partition information to register, if parsing fails;
566 * only valid if %nr_parts > %0
567 * @nr_parts: the number of partitions in parts, if zero then the full
568 * MTD device is registered if no partition info is found
570 * This function aggregates MTD partitions parsing (done by
571 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
572 * basically follows the most common pattern found in many MTD drivers:
574 * * It first tries to probe partitions on MTD device @mtd using parsers
575 * specified in @types (if @types is %NULL, then the default list of parsers
576 * is used, see 'parse_mtd_partitions()' for more information). If none are
577 * found this functions tries to fallback to information specified in
579 * * If any partitioning info was found, this function registers the found
580 * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
581 * as a whole is registered first.
582 * * If no partitions were found this function just registers the MTD device
585 * Returns zero in case of success and a negative error code in case of failure.
587 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
588 struct mtd_part_parser_data *parser_data,
589 const struct mtd_partition *parts,
592 struct mtd_partitions parsed;
595 memset(&parsed, 0, sizeof(parsed));
597 ret = parse_mtd_partitions(mtd, types, &parsed, parser_data);
598 if ((ret < 0 || parsed.nr_parts == 0) && parts && nr_parts) {
599 /* Fall back to driver-provided partitions */
600 parsed = (struct mtd_partitions){
602 .nr_parts = nr_parts,
604 } else if (ret < 0) {
605 /* Didn't come up with parsed OR fallback partitions */
606 pr_info("mtd: failed to find partitions; one or more parsers reports errors (%d)\n",
608 /* Don't abort on errors; we can still use unpartitioned MTD */
609 memset(&parsed, 0, sizeof(parsed));
612 ret = mtd_add_device_partitions(mtd, &parsed);
617 * FIXME: some drivers unfortunately call this function more than once.
618 * So we have to check if we've already assigned the reboot notifier.
620 * Generally, we can make multiple calls work for most cases, but it
621 * does cause problems with parse_mtd_partitions() above (e.g.,
622 * cmdlineparts will register partitions more than once).
624 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
625 "MTD already registered\n");
626 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
627 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
628 register_reboot_notifier(&mtd->reboot_notifier);
632 /* Cleanup any parsed partitions */
633 mtd_part_parser_cleanup(&parsed);
636 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
639 * mtd_device_unregister - unregister an existing MTD device.
641 * @master: the MTD device to unregister. This will unregister both the master
642 * and any partitions if registered.
644 int mtd_device_unregister(struct mtd_info *master)
649 unregister_reboot_notifier(&master->reboot_notifier);
651 err = del_mtd_partitions(master);
655 if (!device_is_registered(&master->dev))
658 return del_mtd_device(master);
660 EXPORT_SYMBOL_GPL(mtd_device_unregister);
663 * register_mtd_user - register a 'user' of MTD devices.
664 * @new: pointer to notifier info structure
666 * Registers a pair of callbacks function to be called upon addition
667 * or removal of MTD devices. Causes the 'add' callback to be immediately
668 * invoked for each MTD device currently present in the system.
670 void register_mtd_user (struct mtd_notifier *new)
672 struct mtd_info *mtd;
674 mutex_lock(&mtd_table_mutex);
676 list_add(&new->list, &mtd_notifiers);
678 __module_get(THIS_MODULE);
680 mtd_for_each_device(mtd)
683 mutex_unlock(&mtd_table_mutex);
685 EXPORT_SYMBOL_GPL(register_mtd_user);
688 * unregister_mtd_user - unregister a 'user' of MTD devices.
689 * @old: pointer to notifier info structure
691 * Removes a callback function pair from the list of 'users' to be
692 * notified upon addition or removal of MTD devices. Causes the
693 * 'remove' callback to be immediately invoked for each MTD device
694 * currently present in the system.
696 int unregister_mtd_user (struct mtd_notifier *old)
698 struct mtd_info *mtd;
700 mutex_lock(&mtd_table_mutex);
702 module_put(THIS_MODULE);
704 mtd_for_each_device(mtd)
707 list_del(&old->list);
708 mutex_unlock(&mtd_table_mutex);
711 EXPORT_SYMBOL_GPL(unregister_mtd_user);
714 * get_mtd_device - obtain a validated handle for an MTD device
715 * @mtd: last known address of the required MTD device
716 * @num: internal device number of the required MTD device
718 * Given a number and NULL address, return the num'th entry in the device
719 * table, if any. Given an address and num == -1, search the device table
720 * for a device with that address and return if it's still present. Given
721 * both, return the num'th driver only if its address matches. Return
724 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
726 struct mtd_info *ret = NULL, *other;
729 mutex_lock(&mtd_table_mutex);
732 mtd_for_each_device(other) {
738 } else if (num >= 0) {
739 ret = idr_find(&mtd_idr, num);
740 if (mtd && mtd != ret)
749 err = __get_mtd_device(ret);
753 mutex_unlock(&mtd_table_mutex);
756 EXPORT_SYMBOL_GPL(get_mtd_device);
759 int __get_mtd_device(struct mtd_info *mtd)
763 if (!try_module_get(mtd->owner))
766 if (mtd->_get_device) {
767 err = mtd->_get_device(mtd);
770 module_put(mtd->owner);
777 EXPORT_SYMBOL_GPL(__get_mtd_device);
780 * get_mtd_device_nm - obtain a validated handle for an MTD device by
782 * @name: MTD device name to open
784 * This function returns MTD device description structure in case of
785 * success and an error code in case of failure.
787 struct mtd_info *get_mtd_device_nm(const char *name)
790 struct mtd_info *mtd = NULL, *other;
792 mutex_lock(&mtd_table_mutex);
794 mtd_for_each_device(other) {
795 if (!strcmp(name, other->name)) {
804 err = __get_mtd_device(mtd);
808 mutex_unlock(&mtd_table_mutex);
812 mutex_unlock(&mtd_table_mutex);
815 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
817 void put_mtd_device(struct mtd_info *mtd)
819 mutex_lock(&mtd_table_mutex);
820 __put_mtd_device(mtd);
821 mutex_unlock(&mtd_table_mutex);
824 EXPORT_SYMBOL_GPL(put_mtd_device);
826 void __put_mtd_device(struct mtd_info *mtd)
829 BUG_ON(mtd->usecount < 0);
831 if (mtd->_put_device)
832 mtd->_put_device(mtd);
834 module_put(mtd->owner);
836 EXPORT_SYMBOL_GPL(__put_mtd_device);
839 * Erase is an asynchronous operation. Device drivers are supposed
840 * to call instr->callback() whenever the operation completes, even
841 * if it completes with a failure.
842 * Callers are supposed to pass a callback function and wait for it
843 * to be called before writing to the block.
845 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
847 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
849 if (!(mtd->flags & MTD_WRITEABLE))
851 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
853 instr->state = MTD_ERASE_DONE;
854 mtd_erase_callback(instr);
857 return mtd->_erase(mtd, instr);
859 EXPORT_SYMBOL_GPL(mtd_erase);
862 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
864 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
865 void **virt, resource_size_t *phys)
873 if (from < 0 || from >= mtd->size || len > mtd->size - from)
877 return mtd->_point(mtd, from, len, retlen, virt, phys);
879 EXPORT_SYMBOL_GPL(mtd_point);
881 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
882 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
886 if (from < 0 || from >= mtd->size || len > mtd->size - from)
890 return mtd->_unpoint(mtd, from, len);
892 EXPORT_SYMBOL_GPL(mtd_unpoint);
895 * Allow NOMMU mmap() to directly map the device (if not NULL)
896 * - return the address to which the offset maps
897 * - return -ENOSYS to indicate refusal to do the mapping
899 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
900 unsigned long offset, unsigned long flags)
902 if (!mtd->_get_unmapped_area)
904 if (offset >= mtd->size || len > mtd->size - offset)
906 return mtd->_get_unmapped_area(mtd, len, offset, flags);
908 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
910 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
915 if (from < 0 || from >= mtd->size || len > mtd->size - from)
921 * In the absence of an error, drivers return a non-negative integer
922 * representing the maximum number of bitflips that were corrected on
923 * any one ecc region (if applicable; zero otherwise).
925 ret_code = mtd->_read(mtd, from, len, retlen, buf);
926 if (unlikely(ret_code < 0))
928 if (mtd->ecc_strength == 0)
929 return 0; /* device lacks ecc */
930 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
932 EXPORT_SYMBOL_GPL(mtd_read);
934 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
938 if (to < 0 || to >= mtd->size || len > mtd->size - to)
940 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
944 return mtd->_write(mtd, to, len, retlen, buf);
946 EXPORT_SYMBOL_GPL(mtd_write);
949 * In blackbox flight recorder like scenarios we want to make successful writes
950 * in interrupt context. panic_write() is only intended to be called when its
951 * known the kernel is about to panic and we need the write to succeed. Since
952 * the kernel is not going to be running for much longer, this function can
953 * break locks and delay to ensure the write succeeds (but not sleep).
955 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
959 if (!mtd->_panic_write)
961 if (to < 0 || to >= mtd->size || len > mtd->size - to)
963 if (!(mtd->flags & MTD_WRITEABLE))
967 return mtd->_panic_write(mtd, to, len, retlen, buf);
969 EXPORT_SYMBOL_GPL(mtd_panic_write);
971 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
974 ops->retlen = ops->oobretlen = 0;
978 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
979 * similar to mtd->_read(), returning a non-negative integer
980 * representing max bitflips. In other cases, mtd->_read_oob() may
981 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
983 ret_code = mtd->_read_oob(mtd, from, ops);
984 if (unlikely(ret_code < 0))
986 if (mtd->ecc_strength == 0)
987 return 0; /* device lacks ecc */
988 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
990 EXPORT_SYMBOL_GPL(mtd_read_oob);
993 * Method to access the protection register area, present in some flash
994 * devices. The user data is one time programmable but the factory data is read
997 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
998 struct otp_info *buf)
1000 if (!mtd->_get_fact_prot_info)
1004 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1006 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1008 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1009 size_t *retlen, u_char *buf)
1012 if (!mtd->_read_fact_prot_reg)
1016 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1018 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1020 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1021 struct otp_info *buf)
1023 if (!mtd->_get_user_prot_info)
1027 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1029 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1031 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1032 size_t *retlen, u_char *buf)
1035 if (!mtd->_read_user_prot_reg)
1039 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1041 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1043 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1044 size_t *retlen, u_char *buf)
1049 if (!mtd->_write_user_prot_reg)
1053 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1058 * If no data could be written at all, we are out of memory and
1059 * must return -ENOSPC.
1061 return (*retlen) ? 0 : -ENOSPC;
1063 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1065 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1067 if (!mtd->_lock_user_prot_reg)
1071 return mtd->_lock_user_prot_reg(mtd, from, len);
1073 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1075 /* Chip-supported device locking */
1076 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1080 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1084 return mtd->_lock(mtd, ofs, len);
1086 EXPORT_SYMBOL_GPL(mtd_lock);
1088 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1092 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1096 return mtd->_unlock(mtd, ofs, len);
1098 EXPORT_SYMBOL_GPL(mtd_unlock);
1100 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1102 if (!mtd->_is_locked)
1104 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1108 return mtd->_is_locked(mtd, ofs, len);
1110 EXPORT_SYMBOL_GPL(mtd_is_locked);
1112 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1114 if (ofs < 0 || ofs >= mtd->size)
1116 if (!mtd->_block_isreserved)
1118 return mtd->_block_isreserved(mtd, ofs);
1120 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1122 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1124 if (ofs < 0 || ofs >= mtd->size)
1126 if (!mtd->_block_isbad)
1128 return mtd->_block_isbad(mtd, ofs);
1130 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1132 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1134 if (!mtd->_block_markbad)
1136 if (ofs < 0 || ofs >= mtd->size)
1138 if (!(mtd->flags & MTD_WRITEABLE))
1140 return mtd->_block_markbad(mtd, ofs);
1142 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1145 * default_mtd_writev - the default writev method
1146 * @mtd: mtd device description object pointer
1147 * @vecs: the vectors to write
1148 * @count: count of vectors in @vecs
1149 * @to: the MTD device offset to write to
1150 * @retlen: on exit contains the count of bytes written to the MTD device.
1152 * This function returns zero in case of success and a negative error code in
1155 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1156 unsigned long count, loff_t to, size_t *retlen)
1159 size_t totlen = 0, thislen;
1162 for (i = 0; i < count; i++) {
1163 if (!vecs[i].iov_len)
1165 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1168 if (ret || thislen != vecs[i].iov_len)
1170 to += vecs[i].iov_len;
1177 * mtd_writev - the vector-based MTD write method
1178 * @mtd: mtd device description object pointer
1179 * @vecs: the vectors to write
1180 * @count: count of vectors in @vecs
1181 * @to: the MTD device offset to write to
1182 * @retlen: on exit contains the count of bytes written to the MTD device.
1184 * This function returns zero in case of success and a negative error code in
1187 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1188 unsigned long count, loff_t to, size_t *retlen)
1191 if (!(mtd->flags & MTD_WRITEABLE))
1194 return default_mtd_writev(mtd, vecs, count, to, retlen);
1195 return mtd->_writev(mtd, vecs, count, to, retlen);
1197 EXPORT_SYMBOL_GPL(mtd_writev);
1200 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1201 * @mtd: mtd device description object pointer
1202 * @size: a pointer to the ideal or maximum size of the allocation, points
1203 * to the actual allocation size on success.
1205 * This routine attempts to allocate a contiguous kernel buffer up to
1206 * the specified size, backing off the size of the request exponentially
1207 * until the request succeeds or until the allocation size falls below
1208 * the system page size. This attempts to make sure it does not adversely
1209 * impact system performance, so when allocating more than one page, we
1210 * ask the memory allocator to avoid re-trying, swapping, writing back
1211 * or performing I/O.
1213 * Note, this function also makes sure that the allocated buffer is aligned to
1214 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1216 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1217 * to handle smaller (i.e. degraded) buffer allocations under low- or
1218 * fragmented-memory situations where such reduced allocations, from a
1219 * requested ideal, are allowed.
1221 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1223 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1225 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1226 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1229 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1231 while (*size > min_alloc) {
1232 kbuf = kmalloc(*size, flags);
1237 *size = ALIGN(*size, mtd->writesize);
1241 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1242 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1244 return kmalloc(*size, GFP_KERNEL);
1246 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1248 #ifdef CONFIG_PROC_FS
1250 /*====================================================================*/
1251 /* Support for /proc/mtd */
1253 static int mtd_proc_show(struct seq_file *m, void *v)
1255 struct mtd_info *mtd;
1257 seq_puts(m, "dev: size erasesize name\n");
1258 mutex_lock(&mtd_table_mutex);
1259 mtd_for_each_device(mtd) {
1260 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1261 mtd->index, (unsigned long long)mtd->size,
1262 mtd->erasesize, mtd->name);
1264 mutex_unlock(&mtd_table_mutex);
1268 static int mtd_proc_open(struct inode *inode, struct file *file)
1270 return single_open(file, mtd_proc_show, NULL);
1273 static const struct file_operations mtd_proc_ops = {
1274 .open = mtd_proc_open,
1276 .llseek = seq_lseek,
1277 .release = single_release,
1279 #endif /* CONFIG_PROC_FS */
1281 /*====================================================================*/
1284 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1288 ret = bdi_init(bdi);
1290 ret = bdi_register(bdi, NULL, "%s", name);
1298 static struct proc_dir_entry *proc_mtd;
1300 static int __init init_mtd(void)
1304 ret = class_register(&mtd_class);
1308 ret = mtd_bdi_init(&mtd_bdi, "mtd");
1312 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1314 ret = init_mtdchar();
1322 remove_proc_entry("mtd", NULL);
1324 class_unregister(&mtd_class);
1326 pr_err("Error registering mtd class or bdi: %d\n", ret);
1330 static void __exit cleanup_mtd(void)
1334 remove_proc_entry("mtd", NULL);
1335 class_unregister(&mtd_class);
1336 bdi_destroy(&mtd_bdi);
1337 idr_destroy(&mtd_idr);
1340 module_init(init_mtd);
1341 module_exit(cleanup_mtd);
1343 MODULE_LICENSE("GPL");
1344 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1345 MODULE_DESCRIPTION("Core MTD registration and access routines");