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>
46 static struct backing_dev_info mtd_bdi = {
49 static int mtd_cls_suspend(struct device *dev, pm_message_t state);
50 static int mtd_cls_resume(struct device *dev);
52 static struct class mtd_class = {
55 .suspend = mtd_cls_suspend,
56 .resume = mtd_cls_resume,
59 static DEFINE_IDR(mtd_idr);
61 /* These are exported solely for the purpose of mtd_blkdevs.c. You
62 should not use them for _anything_ else */
63 DEFINE_MUTEX(mtd_table_mutex);
64 EXPORT_SYMBOL_GPL(mtd_table_mutex);
66 struct mtd_info *__mtd_next_device(int i)
68 return idr_get_next(&mtd_idr, &i);
70 EXPORT_SYMBOL_GPL(__mtd_next_device);
72 static LIST_HEAD(mtd_notifiers);
75 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
77 /* REVISIT once MTD uses the driver model better, whoever allocates
78 * the mtd_info will probably want to use the release() hook...
80 static void mtd_release(struct device *dev)
82 struct mtd_info *mtd = dev_get_drvdata(dev);
83 dev_t index = MTD_DEVT(mtd->index);
85 /* remove /dev/mtdXro node */
86 device_destroy(&mtd_class, index + 1);
89 static int mtd_cls_suspend(struct device *dev, pm_message_t state)
91 struct mtd_info *mtd = dev_get_drvdata(dev);
93 return mtd ? mtd_suspend(mtd) : 0;
96 static int mtd_cls_resume(struct device *dev)
98 struct mtd_info *mtd = dev_get_drvdata(dev);
105 static ssize_t mtd_type_show(struct device *dev,
106 struct device_attribute *attr, char *buf)
108 struct mtd_info *mtd = dev_get_drvdata(dev);
133 case MTD_MLCNANDFLASH:
140 return snprintf(buf, PAGE_SIZE, "%s\n", type);
142 static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
144 static ssize_t mtd_flags_show(struct device *dev,
145 struct device_attribute *attr, char *buf)
147 struct mtd_info *mtd = dev_get_drvdata(dev);
149 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
152 static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
154 static ssize_t mtd_size_show(struct device *dev,
155 struct device_attribute *attr, char *buf)
157 struct mtd_info *mtd = dev_get_drvdata(dev);
159 return snprintf(buf, PAGE_SIZE, "%llu\n",
160 (unsigned long long)mtd->size);
163 static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
165 static ssize_t mtd_erasesize_show(struct device *dev,
166 struct device_attribute *attr, char *buf)
168 struct mtd_info *mtd = dev_get_drvdata(dev);
170 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
173 static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
175 static ssize_t mtd_writesize_show(struct device *dev,
176 struct device_attribute *attr, char *buf)
178 struct mtd_info *mtd = dev_get_drvdata(dev);
180 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
183 static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
185 static ssize_t mtd_subpagesize_show(struct device *dev,
186 struct device_attribute *attr, char *buf)
188 struct mtd_info *mtd = dev_get_drvdata(dev);
189 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
191 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
194 static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
196 static ssize_t mtd_oobsize_show(struct device *dev,
197 struct device_attribute *attr, char *buf)
199 struct mtd_info *mtd = dev_get_drvdata(dev);
201 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
204 static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
206 static ssize_t mtd_numeraseregions_show(struct device *dev,
207 struct device_attribute *attr, char *buf)
209 struct mtd_info *mtd = dev_get_drvdata(dev);
211 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
214 static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
217 static ssize_t mtd_name_show(struct device *dev,
218 struct device_attribute *attr, char *buf)
220 struct mtd_info *mtd = dev_get_drvdata(dev);
222 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
225 static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
227 static ssize_t mtd_ecc_strength_show(struct device *dev,
228 struct device_attribute *attr, char *buf)
230 struct mtd_info *mtd = dev_get_drvdata(dev);
232 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
234 static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
236 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
237 struct device_attribute *attr,
240 struct mtd_info *mtd = dev_get_drvdata(dev);
242 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
245 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
246 struct device_attribute *attr,
247 const char *buf, size_t count)
249 struct mtd_info *mtd = dev_get_drvdata(dev);
250 unsigned int bitflip_threshold;
253 retval = kstrtouint(buf, 0, &bitflip_threshold);
257 mtd->bitflip_threshold = bitflip_threshold;
260 static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
261 mtd_bitflip_threshold_show,
262 mtd_bitflip_threshold_store);
264 static ssize_t mtd_ecc_step_size_show(struct device *dev,
265 struct device_attribute *attr, char *buf)
267 struct mtd_info *mtd = dev_get_drvdata(dev);
269 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
272 static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
274 static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
275 struct device_attribute *attr, char *buf)
277 struct mtd_info *mtd = dev_get_drvdata(dev);
278 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
280 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
282 static DEVICE_ATTR(corrected_bits, S_IRUGO,
283 mtd_ecc_stats_corrected_show, NULL);
285 static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
286 struct device_attribute *attr, char *buf)
288 struct mtd_info *mtd = dev_get_drvdata(dev);
289 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
291 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
293 static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
295 static ssize_t mtd_badblocks_show(struct device *dev,
296 struct device_attribute *attr, char *buf)
298 struct mtd_info *mtd = dev_get_drvdata(dev);
299 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
301 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
303 static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
305 static ssize_t mtd_bbtblocks_show(struct device *dev,
306 struct device_attribute *attr, char *buf)
308 struct mtd_info *mtd = dev_get_drvdata(dev);
309 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
311 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
313 static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
315 static struct attribute *mtd_attrs[] = {
317 &dev_attr_flags.attr,
319 &dev_attr_erasesize.attr,
320 &dev_attr_writesize.attr,
321 &dev_attr_subpagesize.attr,
322 &dev_attr_oobsize.attr,
323 &dev_attr_numeraseregions.attr,
325 &dev_attr_ecc_strength.attr,
326 &dev_attr_ecc_step_size.attr,
327 &dev_attr_corrected_bits.attr,
328 &dev_attr_ecc_failures.attr,
329 &dev_attr_bad_blocks.attr,
330 &dev_attr_bbt_blocks.attr,
331 &dev_attr_bitflip_threshold.attr,
334 ATTRIBUTE_GROUPS(mtd);
336 static struct device_type mtd_devtype = {
338 .groups = mtd_groups,
339 .release = mtd_release,
343 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
347 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
348 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
350 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
353 return NOMMU_MAP_COPY;
356 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
360 * add_mtd_device - register an MTD device
361 * @mtd: pointer to new MTD device info structure
363 * Add a device to the list of MTD devices present in the system, and
364 * notify each currently active MTD 'user' of its arrival. Returns
365 * zero on success or 1 on failure, which currently will only happen
366 * if there is insufficient memory or a sysfs error.
369 int add_mtd_device(struct mtd_info *mtd)
371 struct mtd_notifier *not;
374 mtd->backing_dev_info = &mtd_bdi;
376 BUG_ON(mtd->writesize == 0);
377 mutex_lock(&mtd_table_mutex);
379 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
386 /* default value if not set by driver */
387 if (mtd->bitflip_threshold == 0)
388 mtd->bitflip_threshold = mtd->ecc_strength;
390 if (is_power_of_2(mtd->erasesize))
391 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
393 mtd->erasesize_shift = 0;
395 if (is_power_of_2(mtd->writesize))
396 mtd->writesize_shift = ffs(mtd->writesize) - 1;
398 mtd->writesize_shift = 0;
400 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
401 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
403 /* Some chips always power up locked. Unlock them now */
404 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
405 error = mtd_unlock(mtd, 0, mtd->size);
406 if (error && error != -EOPNOTSUPP)
408 "%s: unlock failed, writes may not work\n",
412 /* Caller should have set dev.parent to match the
415 mtd->dev.type = &mtd_devtype;
416 mtd->dev.class = &mtd_class;
417 mtd->dev.devt = MTD_DEVT(i);
418 dev_set_name(&mtd->dev, "mtd%d", i);
419 dev_set_drvdata(&mtd->dev, mtd);
420 if (device_register(&mtd->dev) != 0)
423 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
426 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
427 /* No need to get a refcount on the module containing
428 the notifier, since we hold the mtd_table_mutex */
429 list_for_each_entry(not, &mtd_notifiers, list)
432 mutex_unlock(&mtd_table_mutex);
433 /* We _know_ we aren't being removed, because
434 our caller is still holding us here. So none
435 of this try_ nonsense, and no bitching about it
437 __module_get(THIS_MODULE);
441 idr_remove(&mtd_idr, i);
443 mutex_unlock(&mtd_table_mutex);
448 * del_mtd_device - unregister an MTD device
449 * @mtd: pointer to MTD device info structure
451 * Remove a device from the list of MTD devices present in the system,
452 * and notify each currently active MTD 'user' of its departure.
453 * Returns zero on success or 1 on failure, which currently will happen
454 * if the requested device does not appear to be present in the list.
457 int del_mtd_device(struct mtd_info *mtd)
460 struct mtd_notifier *not;
462 mutex_lock(&mtd_table_mutex);
464 if (idr_find(&mtd_idr, mtd->index) != mtd) {
469 /* No need to get a refcount on the module containing
470 the notifier, since we hold the mtd_table_mutex */
471 list_for_each_entry(not, &mtd_notifiers, list)
475 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
476 mtd->index, mtd->name, mtd->usecount);
479 device_unregister(&mtd->dev);
481 idr_remove(&mtd_idr, mtd->index);
483 module_put(THIS_MODULE);
488 mutex_unlock(&mtd_table_mutex);
493 * mtd_device_parse_register - parse partitions and register an MTD device.
495 * @mtd: the MTD device to register
496 * @types: the list of MTD partition probes to try, see
497 * 'parse_mtd_partitions()' for more information
498 * @parser_data: MTD partition parser-specific data
499 * @parts: fallback partition information to register, if parsing fails;
500 * only valid if %nr_parts > %0
501 * @nr_parts: the number of partitions in parts, if zero then the full
502 * MTD device is registered if no partition info is found
504 * This function aggregates MTD partitions parsing (done by
505 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
506 * basically follows the most common pattern found in many MTD drivers:
508 * * It first tries to probe partitions on MTD device @mtd using parsers
509 * specified in @types (if @types is %NULL, then the default list of parsers
510 * is used, see 'parse_mtd_partitions()' for more information). If none are
511 * found this functions tries to fallback to information specified in
513 * * If any partitioning info was found, this function registers the found
515 * * If no partitions were found this function just registers the MTD device
518 * Returns zero in case of success and a negative error code in case of failure.
520 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
521 struct mtd_part_parser_data *parser_data,
522 const struct mtd_partition *parts,
526 struct mtd_partition *real_parts;
528 err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
529 if (err <= 0 && nr_parts && parts) {
530 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
539 err = add_mtd_partitions(mtd, real_parts, err);
541 } else if (err == 0) {
542 err = add_mtd_device(mtd);
549 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
552 * mtd_device_unregister - unregister an existing MTD device.
554 * @master: the MTD device to unregister. This will unregister both the master
555 * and any partitions if registered.
557 int mtd_device_unregister(struct mtd_info *master)
561 err = del_mtd_partitions(master);
565 if (!device_is_registered(&master->dev))
568 return del_mtd_device(master);
570 EXPORT_SYMBOL_GPL(mtd_device_unregister);
573 * register_mtd_user - register a 'user' of MTD devices.
574 * @new: pointer to notifier info structure
576 * Registers a pair of callbacks function to be called upon addition
577 * or removal of MTD devices. Causes the 'add' callback to be immediately
578 * invoked for each MTD device currently present in the system.
580 void register_mtd_user (struct mtd_notifier *new)
582 struct mtd_info *mtd;
584 mutex_lock(&mtd_table_mutex);
586 list_add(&new->list, &mtd_notifiers);
588 __module_get(THIS_MODULE);
590 mtd_for_each_device(mtd)
593 mutex_unlock(&mtd_table_mutex);
595 EXPORT_SYMBOL_GPL(register_mtd_user);
598 * unregister_mtd_user - unregister a 'user' of MTD devices.
599 * @old: pointer to notifier info structure
601 * Removes a callback function pair from the list of 'users' to be
602 * notified upon addition or removal of MTD devices. Causes the
603 * 'remove' callback to be immediately invoked for each MTD device
604 * currently present in the system.
606 int unregister_mtd_user (struct mtd_notifier *old)
608 struct mtd_info *mtd;
610 mutex_lock(&mtd_table_mutex);
612 module_put(THIS_MODULE);
614 mtd_for_each_device(mtd)
617 list_del(&old->list);
618 mutex_unlock(&mtd_table_mutex);
621 EXPORT_SYMBOL_GPL(unregister_mtd_user);
624 * get_mtd_device - obtain a validated handle for an MTD device
625 * @mtd: last known address of the required MTD device
626 * @num: internal device number of the required MTD device
628 * Given a number and NULL address, return the num'th entry in the device
629 * table, if any. Given an address and num == -1, search the device table
630 * for a device with that address and return if it's still present. Given
631 * both, return the num'th driver only if its address matches. Return
634 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
636 struct mtd_info *ret = NULL, *other;
639 mutex_lock(&mtd_table_mutex);
642 mtd_for_each_device(other) {
648 } else if (num >= 0) {
649 ret = idr_find(&mtd_idr, num);
650 if (mtd && mtd != ret)
659 err = __get_mtd_device(ret);
663 mutex_unlock(&mtd_table_mutex);
666 EXPORT_SYMBOL_GPL(get_mtd_device);
669 int __get_mtd_device(struct mtd_info *mtd)
673 if (!try_module_get(mtd->owner))
676 if (mtd->_get_device) {
677 err = mtd->_get_device(mtd);
680 module_put(mtd->owner);
687 EXPORT_SYMBOL_GPL(__get_mtd_device);
690 * get_mtd_device_nm - obtain a validated handle for an MTD device by
692 * @name: MTD device name to open
694 * This function returns MTD device description structure in case of
695 * success and an error code in case of failure.
697 struct mtd_info *get_mtd_device_nm(const char *name)
700 struct mtd_info *mtd = NULL, *other;
702 mutex_lock(&mtd_table_mutex);
704 mtd_for_each_device(other) {
705 if (!strcmp(name, other->name)) {
714 err = __get_mtd_device(mtd);
718 mutex_unlock(&mtd_table_mutex);
722 mutex_unlock(&mtd_table_mutex);
725 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
727 void put_mtd_device(struct mtd_info *mtd)
729 mutex_lock(&mtd_table_mutex);
730 __put_mtd_device(mtd);
731 mutex_unlock(&mtd_table_mutex);
734 EXPORT_SYMBOL_GPL(put_mtd_device);
736 void __put_mtd_device(struct mtd_info *mtd)
739 BUG_ON(mtd->usecount < 0);
741 if (mtd->_put_device)
742 mtd->_put_device(mtd);
744 module_put(mtd->owner);
746 EXPORT_SYMBOL_GPL(__put_mtd_device);
749 * Erase is an asynchronous operation. Device drivers are supposed
750 * to call instr->callback() whenever the operation completes, even
751 * if it completes with a failure.
752 * Callers are supposed to pass a callback function and wait for it
753 * to be called before writing to the block.
755 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
757 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
759 if (!(mtd->flags & MTD_WRITEABLE))
761 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
763 instr->state = MTD_ERASE_DONE;
764 mtd_erase_callback(instr);
767 return mtd->_erase(mtd, instr);
769 EXPORT_SYMBOL_GPL(mtd_erase);
772 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
774 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
775 void **virt, resource_size_t *phys)
783 if (from < 0 || from >= mtd->size || len > mtd->size - from)
787 return mtd->_point(mtd, from, len, retlen, virt, phys);
789 EXPORT_SYMBOL_GPL(mtd_point);
791 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
792 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
796 if (from < 0 || from >= mtd->size || len > mtd->size - from)
800 return mtd->_unpoint(mtd, from, len);
802 EXPORT_SYMBOL_GPL(mtd_unpoint);
805 * Allow NOMMU mmap() to directly map the device (if not NULL)
806 * - return the address to which the offset maps
807 * - return -ENOSYS to indicate refusal to do the mapping
809 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
810 unsigned long offset, unsigned long flags)
812 if (!mtd->_get_unmapped_area)
814 if (offset >= mtd->size || len > mtd->size - offset)
816 return mtd->_get_unmapped_area(mtd, len, offset, flags);
818 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
820 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
825 if (from < 0 || from >= mtd->size || len > mtd->size - from)
831 * In the absence of an error, drivers return a non-negative integer
832 * representing the maximum number of bitflips that were corrected on
833 * any one ecc region (if applicable; zero otherwise).
835 ret_code = mtd->_read(mtd, from, len, retlen, buf);
836 if (unlikely(ret_code < 0))
838 if (mtd->ecc_strength == 0)
839 return 0; /* device lacks ecc */
840 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
842 EXPORT_SYMBOL_GPL(mtd_read);
844 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
848 if (to < 0 || to >= mtd->size || len > mtd->size - to)
850 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
854 return mtd->_write(mtd, to, len, retlen, buf);
856 EXPORT_SYMBOL_GPL(mtd_write);
859 * In blackbox flight recorder like scenarios we want to make successful writes
860 * in interrupt context. panic_write() is only intended to be called when its
861 * known the kernel is about to panic and we need the write to succeed. Since
862 * the kernel is not going to be running for much longer, this function can
863 * break locks and delay to ensure the write succeeds (but not sleep).
865 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
869 if (!mtd->_panic_write)
871 if (to < 0 || to >= mtd->size || len > mtd->size - to)
873 if (!(mtd->flags & MTD_WRITEABLE))
877 return mtd->_panic_write(mtd, to, len, retlen, buf);
879 EXPORT_SYMBOL_GPL(mtd_panic_write);
881 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
884 ops->retlen = ops->oobretlen = 0;
888 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
889 * similar to mtd->_read(), returning a non-negative integer
890 * representing max bitflips. In other cases, mtd->_read_oob() may
891 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
893 ret_code = mtd->_read_oob(mtd, from, ops);
894 if (unlikely(ret_code < 0))
896 if (mtd->ecc_strength == 0)
897 return 0; /* device lacks ecc */
898 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
900 EXPORT_SYMBOL_GPL(mtd_read_oob);
903 * Method to access the protection register area, present in some flash
904 * devices. The user data is one time programmable but the factory data is read
907 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
908 struct otp_info *buf)
910 if (!mtd->_get_fact_prot_info)
914 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
916 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
918 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
919 size_t *retlen, u_char *buf)
922 if (!mtd->_read_fact_prot_reg)
926 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
928 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
930 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
931 struct otp_info *buf)
933 if (!mtd->_get_user_prot_info)
937 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
939 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
941 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
942 size_t *retlen, u_char *buf)
945 if (!mtd->_read_user_prot_reg)
949 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
951 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
953 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
954 size_t *retlen, u_char *buf)
959 if (!mtd->_write_user_prot_reg)
963 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
968 * If no data could be written at all, we are out of memory and
969 * must return -ENOSPC.
971 return (*retlen) ? 0 : -ENOSPC;
973 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
975 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
977 if (!mtd->_lock_user_prot_reg)
981 return mtd->_lock_user_prot_reg(mtd, from, len);
983 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
985 /* Chip-supported device locking */
986 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
990 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
994 return mtd->_lock(mtd, ofs, len);
996 EXPORT_SYMBOL_GPL(mtd_lock);
998 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1002 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1006 return mtd->_unlock(mtd, ofs, len);
1008 EXPORT_SYMBOL_GPL(mtd_unlock);
1010 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1012 if (!mtd->_is_locked)
1014 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1018 return mtd->_is_locked(mtd, ofs, len);
1020 EXPORT_SYMBOL_GPL(mtd_is_locked);
1022 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1024 if (ofs < 0 || ofs >= mtd->size)
1026 if (!mtd->_block_isreserved)
1028 return mtd->_block_isreserved(mtd, ofs);
1030 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1032 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1034 if (ofs < 0 || ofs >= mtd->size)
1036 if (!mtd->_block_isbad)
1038 return mtd->_block_isbad(mtd, ofs);
1040 EXPORT_SYMBOL_GPL(mtd_block_isbad);
1042 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1044 if (!mtd->_block_markbad)
1046 if (ofs < 0 || ofs >= mtd->size)
1048 if (!(mtd->flags & MTD_WRITEABLE))
1050 return mtd->_block_markbad(mtd, ofs);
1052 EXPORT_SYMBOL_GPL(mtd_block_markbad);
1055 * default_mtd_writev - the default writev method
1056 * @mtd: mtd device description object pointer
1057 * @vecs: the vectors to write
1058 * @count: count of vectors in @vecs
1059 * @to: the MTD device offset to write to
1060 * @retlen: on exit contains the count of bytes written to the MTD device.
1062 * This function returns zero in case of success and a negative error code in
1065 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1066 unsigned long count, loff_t to, size_t *retlen)
1069 size_t totlen = 0, thislen;
1072 for (i = 0; i < count; i++) {
1073 if (!vecs[i].iov_len)
1075 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1078 if (ret || thislen != vecs[i].iov_len)
1080 to += vecs[i].iov_len;
1087 * mtd_writev - the vector-based MTD write method
1088 * @mtd: mtd device description object pointer
1089 * @vecs: the vectors to write
1090 * @count: count of vectors in @vecs
1091 * @to: the MTD device offset to write to
1092 * @retlen: on exit contains the count of bytes written to the MTD device.
1094 * This function returns zero in case of success and a negative error code in
1097 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1098 unsigned long count, loff_t to, size_t *retlen)
1101 if (!(mtd->flags & MTD_WRITEABLE))
1104 return default_mtd_writev(mtd, vecs, count, to, retlen);
1105 return mtd->_writev(mtd, vecs, count, to, retlen);
1107 EXPORT_SYMBOL_GPL(mtd_writev);
1110 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1111 * @mtd: mtd device description object pointer
1112 * @size: a pointer to the ideal or maximum size of the allocation, points
1113 * to the actual allocation size on success.
1115 * This routine attempts to allocate a contiguous kernel buffer up to
1116 * the specified size, backing off the size of the request exponentially
1117 * until the request succeeds or until the allocation size falls below
1118 * the system page size. This attempts to make sure it does not adversely
1119 * impact system performance, so when allocating more than one page, we
1120 * ask the memory allocator to avoid re-trying, swapping, writing back
1121 * or performing I/O.
1123 * Note, this function also makes sure that the allocated buffer is aligned to
1124 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1126 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1127 * to handle smaller (i.e. degraded) buffer allocations under low- or
1128 * fragmented-memory situations where such reduced allocations, from a
1129 * requested ideal, are allowed.
1131 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1133 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1135 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
1136 __GFP_NORETRY | __GFP_NO_KSWAPD;
1137 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1140 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1142 while (*size > min_alloc) {
1143 kbuf = kmalloc(*size, flags);
1148 *size = ALIGN(*size, mtd->writesize);
1152 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1153 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1155 return kmalloc(*size, GFP_KERNEL);
1157 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1159 #ifdef CONFIG_PROC_FS
1161 /*====================================================================*/
1162 /* Support for /proc/mtd */
1164 static int mtd_proc_show(struct seq_file *m, void *v)
1166 struct mtd_info *mtd;
1168 seq_puts(m, "dev: size erasesize name\n");
1169 mutex_lock(&mtd_table_mutex);
1170 mtd_for_each_device(mtd) {
1171 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1172 mtd->index, (unsigned long long)mtd->size,
1173 mtd->erasesize, mtd->name);
1175 mutex_unlock(&mtd_table_mutex);
1179 static int mtd_proc_open(struct inode *inode, struct file *file)
1181 return single_open(file, mtd_proc_show, NULL);
1184 static const struct file_operations mtd_proc_ops = {
1185 .open = mtd_proc_open,
1187 .llseek = seq_lseek,
1188 .release = single_release,
1190 #endif /* CONFIG_PROC_FS */
1192 /*====================================================================*/
1195 static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1199 ret = bdi_init(bdi);
1201 ret = bdi_register(bdi, NULL, "%s", name);
1209 static struct proc_dir_entry *proc_mtd;
1211 static int __init init_mtd(void)
1215 ret = class_register(&mtd_class);
1219 ret = mtd_bdi_init(&mtd_bdi, "mtd");
1223 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1225 ret = init_mtdchar();
1233 remove_proc_entry("mtd", NULL);
1235 class_unregister(&mtd_class);
1237 pr_err("Error registering mtd class or bdi: %d\n", ret);
1241 static void __exit cleanup_mtd(void)
1245 remove_proc_entry("mtd", NULL);
1246 class_unregister(&mtd_class);
1247 bdi_destroy(&mtd_bdi);
1250 module_init(init_mtd);
1251 module_exit(cleanup_mtd);
1253 MODULE_LICENSE("GPL");
1254 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1255 MODULE_DESCRIPTION("Core MTD registration and access routines");