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1/*
2 * Core registration and callback routines for MTD
3 * drivers and users.
4 *
5 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
6 * Copyright © 2006 Red Hat UK Limited
7 *
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.
12 *
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.
17 *
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
21 *
22 */
23
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>
31#include <linux/fs.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
40#include <linux/mtd/mtd.h>
41#include <linux/mtd/partitions.h>
42
43#include "mtdcore.h"
44/*
45 * backing device capabilities for non-mappable devices (such as NAND flash)
46 * - permits private mappings, copies are taken of the data
47 */
48static struct backing_dev_info mtd_bdi_unmappable = {
49 .capabilities = BDI_CAP_MAP_COPY,
50};
51
52/*
53 * backing device capabilities for R/O mappable devices (such as ROM)
54 * - permits private mappings, copies are taken of the data
55 * - permits non-writable shared mappings
56 */
57static struct backing_dev_info mtd_bdi_ro_mappable = {
58 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
59 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
60};
61
62/*
63 * backing device capabilities for writable mappable devices (such as RAM)
64 * - permits private mappings, copies are taken of the data
65 * - permits non-writable shared mappings
66 */
67static struct backing_dev_info mtd_bdi_rw_mappable = {
68 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
69 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
70 BDI_CAP_WRITE_MAP),
71};
72
73static int mtd_cls_suspend(struct device *dev, pm_message_t state);
74static int mtd_cls_resume(struct device *dev);
75
76static struct class mtd_class = {
77 .name = "mtd",
78 .owner = THIS_MODULE,
79 .suspend = mtd_cls_suspend,
80 .resume = mtd_cls_resume,
81};
82
83static DEFINE_IDR(mtd_idr);
84
85/* These are exported solely for the purpose of mtd_blkdevs.c. You
86 should not use them for _anything_ else */
87DEFINE_MUTEX(mtd_table_mutex);
88EXPORT_SYMBOL_GPL(mtd_table_mutex);
89
90struct mtd_info *__mtd_next_device(int i)
91{
92 return idr_get_next(&mtd_idr, &i);
93}
94EXPORT_SYMBOL_GPL(__mtd_next_device);
95
96static LIST_HEAD(mtd_notifiers);
97
98
99#if defined(CONFIG_MTD_CHAR) || defined(CONFIG_MTD_CHAR_MODULE)
100#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
101#else
102#define MTD_DEVT(index) 0
103#endif
104
105/* REVISIT once MTD uses the driver model better, whoever allocates
106 * the mtd_info will probably want to use the release() hook...
107 */
108static void mtd_release(struct device *dev)
109{
110 struct mtd_info __maybe_unused *mtd = dev_get_drvdata(dev);
111 dev_t index = MTD_DEVT(mtd->index);
112
113 /* remove /dev/mtdXro node if needed */
114 if (index)
115 device_destroy(&mtd_class, index + 1);
116}
117
118static int mtd_cls_suspend(struct device *dev, pm_message_t state)
119{
120 struct mtd_info *mtd = dev_get_drvdata(dev);
121
122 return mtd ? mtd_suspend(mtd) : 0;
123}
124
125static int mtd_cls_resume(struct device *dev)
126{
127 struct mtd_info *mtd = dev_get_drvdata(dev);
128
129 if (mtd)
130 mtd_resume(mtd);
131 return 0;
132}
133
134static ssize_t mtd_type_show(struct device *dev,
135 struct device_attribute *attr, char *buf)
136{
137 struct mtd_info *mtd = dev_get_drvdata(dev);
138 char *type;
139
140 switch (mtd->type) {
141 case MTD_ABSENT:
142 type = "absent";
143 break;
144 case MTD_RAM:
145 type = "ram";
146 break;
147 case MTD_ROM:
148 type = "rom";
149 break;
150 case MTD_NORFLASH:
151 type = "nor";
152 break;
153 case MTD_NANDFLASH:
154 type = "nand";
155 break;
156 case MTD_DATAFLASH:
157 type = "dataflash";
158 break;
159 case MTD_UBIVOLUME:
160 type = "ubi";
161 break;
162 default:
163 type = "unknown";
164 }
165
166 return snprintf(buf, PAGE_SIZE, "%s\n", type);
167}
168static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
169
170static ssize_t mtd_flags_show(struct device *dev,
171 struct device_attribute *attr, char *buf)
172{
173 struct mtd_info *mtd = dev_get_drvdata(dev);
174
175 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
176
177}
178static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
179
180static ssize_t mtd_size_show(struct device *dev,
181 struct device_attribute *attr, char *buf)
182{
183 struct mtd_info *mtd = dev_get_drvdata(dev);
184
185 return snprintf(buf, PAGE_SIZE, "%llu\n",
186 (unsigned long long)mtd->size);
187
188}
189static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
190
191static ssize_t mtd_erasesize_show(struct device *dev,
192 struct device_attribute *attr, char *buf)
193{
194 struct mtd_info *mtd = dev_get_drvdata(dev);
195
196 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
197
198}
199static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
200
201static ssize_t mtd_writesize_show(struct device *dev,
202 struct device_attribute *attr, char *buf)
203{
204 struct mtd_info *mtd = dev_get_drvdata(dev);
205
206 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
207
208}
209static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
210
211static ssize_t mtd_subpagesize_show(struct device *dev,
212 struct device_attribute *attr, char *buf)
213{
214 struct mtd_info *mtd = dev_get_drvdata(dev);
215 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
216
217 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
218
219}
220static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
221
222static ssize_t mtd_oobsize_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
224{
225 struct mtd_info *mtd = dev_get_drvdata(dev);
226
227 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
228
229}
230static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
231
232static ssize_t mtd_numeraseregions_show(struct device *dev,
233 struct device_attribute *attr, char *buf)
234{
235 struct mtd_info *mtd = dev_get_drvdata(dev);
236
237 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
238
239}
240static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
241 NULL);
242
243static ssize_t mtd_name_show(struct device *dev,
244 struct device_attribute *attr, char *buf)
245{
246 struct mtd_info *mtd = dev_get_drvdata(dev);
247
248 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
249
250}
251static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
252
253static ssize_t mtd_ecc_strength_show(struct device *dev,
254 struct device_attribute *attr, char *buf)
255{
256 struct mtd_info *mtd = dev_get_drvdata(dev);
257
258 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
259}
260static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
261
262static ssize_t mtd_bitflip_threshold_show(struct device *dev,
263 struct device_attribute *attr,
264 char *buf)
265{
266 struct mtd_info *mtd = dev_get_drvdata(dev);
267
268 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
269}
270
271static ssize_t mtd_bitflip_threshold_store(struct device *dev,
272 struct device_attribute *attr,
273 const char *buf, size_t count)
274{
275 struct mtd_info *mtd = dev_get_drvdata(dev);
276 unsigned int bitflip_threshold;
277 int retval;
278
279 retval = kstrtouint(buf, 0, &bitflip_threshold);
280 if (retval)
281 return retval;
282
283 mtd->bitflip_threshold = bitflip_threshold;
284 return count;
285}
286static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
287 mtd_bitflip_threshold_show,
288 mtd_bitflip_threshold_store);
289
290static struct attribute *mtd_attrs[] = {
291 &dev_attr_type.attr,
292 &dev_attr_flags.attr,
293 &dev_attr_size.attr,
294 &dev_attr_erasesize.attr,
295 &dev_attr_writesize.attr,
296 &dev_attr_subpagesize.attr,
297 &dev_attr_oobsize.attr,
298 &dev_attr_numeraseregions.attr,
299 &dev_attr_name.attr,
300 &dev_attr_ecc_strength.attr,
301 &dev_attr_bitflip_threshold.attr,
302 NULL,
303};
304
305static struct attribute_group mtd_group = {
306 .attrs = mtd_attrs,
307};
308
309static const struct attribute_group *mtd_groups[] = {
310 &mtd_group,
311 NULL,
312};
313
314static struct device_type mtd_devtype = {
315 .name = "mtd",
316 .groups = mtd_groups,
317 .release = mtd_release,
318};
319
320/**
321 * add_mtd_device - register an MTD device
322 * @mtd: pointer to new MTD device info structure
323 *
324 * Add a device to the list of MTD devices present in the system, and
325 * notify each currently active MTD 'user' of its arrival. Returns
326 * zero on success or 1 on failure, which currently will only happen
327 * if there is insufficient memory or a sysfs error.
328 */
329
330int add_mtd_device(struct mtd_info *mtd)
331{
332 struct mtd_notifier *not;
333 int i, error;
334
335 if (!mtd->backing_dev_info) {
336 switch (mtd->type) {
337 case MTD_RAM:
338 mtd->backing_dev_info = &mtd_bdi_rw_mappable;
339 break;
340 case MTD_ROM:
341 mtd->backing_dev_info = &mtd_bdi_ro_mappable;
342 break;
343 default:
344 mtd->backing_dev_info = &mtd_bdi_unmappable;
345 break;
346 }
347 }
348
349 BUG_ON(mtd->writesize == 0);
350 mutex_lock(&mtd_table_mutex);
351
352 do {
353 if (!idr_pre_get(&mtd_idr, GFP_KERNEL))
354 goto fail_locked;
355 error = idr_get_new(&mtd_idr, mtd, &i);
356 } while (error == -EAGAIN);
357
358 if (error)
359 goto fail_locked;
360
361 mtd->index = i;
362 mtd->usecount = 0;
363
364 /* default value if not set by driver */
365 if (mtd->bitflip_threshold == 0)
366 mtd->bitflip_threshold = mtd->ecc_strength;
367
368 if (is_power_of_2(mtd->erasesize))
369 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
370 else
371 mtd->erasesize_shift = 0;
372
373 if (is_power_of_2(mtd->writesize))
374 mtd->writesize_shift = ffs(mtd->writesize) - 1;
375 else
376 mtd->writesize_shift = 0;
377
378 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
379 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
380
381 /* Some chips always power up locked. Unlock them now */
382 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
383 error = mtd_unlock(mtd, 0, mtd->size);
384 if (error && error != -EOPNOTSUPP)
385 printk(KERN_WARNING
386 "%s: unlock failed, writes may not work\n",
387 mtd->name);
388 }
389
390 /* Caller should have set dev.parent to match the
391 * physical device.
392 */
393 mtd->dev.type = &mtd_devtype;
394 mtd->dev.class = &mtd_class;
395 mtd->dev.devt = MTD_DEVT(i);
396 dev_set_name(&mtd->dev, "mtd%d", i);
397 dev_set_drvdata(&mtd->dev, mtd);
398 if (device_register(&mtd->dev) != 0)
399 goto fail_added;
400
401 if (MTD_DEVT(i))
402 device_create(&mtd_class, mtd->dev.parent,
403 MTD_DEVT(i) + 1,
404 NULL, "mtd%dro", i);
405
406 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
407 /* No need to get a refcount on the module containing
408 the notifier, since we hold the mtd_table_mutex */
409 list_for_each_entry(not, &mtd_notifiers, list)
410 not->add(mtd);
411
412 mutex_unlock(&mtd_table_mutex);
413 /* We _know_ we aren't being removed, because
414 our caller is still holding us here. So none
415 of this try_ nonsense, and no bitching about it
416 either. :) */
417 __module_get(THIS_MODULE);
418 return 0;
419
420fail_added:
421 idr_remove(&mtd_idr, i);
422fail_locked:
423 mutex_unlock(&mtd_table_mutex);
424 return 1;
425}
426
427/**
428 * del_mtd_device - unregister an MTD device
429 * @mtd: pointer to MTD device info structure
430 *
431 * Remove a device from the list of MTD devices present in the system,
432 * and notify each currently active MTD 'user' of its departure.
433 * Returns zero on success or 1 on failure, which currently will happen
434 * if the requested device does not appear to be present in the list.
435 */
436
437int del_mtd_device(struct mtd_info *mtd)
438{
439 int ret;
440 struct mtd_notifier *not;
441
442 mutex_lock(&mtd_table_mutex);
443
444 if (idr_find(&mtd_idr, mtd->index) != mtd) {
445 ret = -ENODEV;
446 goto out_error;
447 }
448
449 /* No need to get a refcount on the module containing
450 the notifier, since we hold the mtd_table_mutex */
451 list_for_each_entry(not, &mtd_notifiers, list)
452 not->remove(mtd);
453
454 if (mtd->usecount) {
455 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
456 mtd->index, mtd->name, mtd->usecount);
457 ret = -EBUSY;
458 } else {
459 device_unregister(&mtd->dev);
460
461 idr_remove(&mtd_idr, mtd->index);
462
463 module_put(THIS_MODULE);
464 ret = 0;
465 }
466
467out_error:
468 mutex_unlock(&mtd_table_mutex);
469 return ret;
470}
471
472/**
473 * mtd_device_parse_register - parse partitions and register an MTD device.
474 *
475 * @mtd: the MTD device to register
476 * @types: the list of MTD partition probes to try, see
477 * 'parse_mtd_partitions()' for more information
478 * @parser_data: MTD partition parser-specific data
479 * @parts: fallback partition information to register, if parsing fails;
480 * only valid if %nr_parts > %0
481 * @nr_parts: the number of partitions in parts, if zero then the full
482 * MTD device is registered if no partition info is found
483 *
484 * This function aggregates MTD partitions parsing (done by
485 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
486 * basically follows the most common pattern found in many MTD drivers:
487 *
488 * * It first tries to probe partitions on MTD device @mtd using parsers
489 * specified in @types (if @types is %NULL, then the default list of parsers
490 * is used, see 'parse_mtd_partitions()' for more information). If none are
491 * found this functions tries to fallback to information specified in
492 * @parts/@nr_parts.
493 * * If any partitioning info was found, this function registers the found
494 * partitions.
495 * * If no partitions were found this function just registers the MTD device
496 * @mtd and exits.
497 *
498 * Returns zero in case of success and a negative error code in case of failure.
499 */
500int mtd_device_parse_register(struct mtd_info *mtd, const char **types,
501 struct mtd_part_parser_data *parser_data,
502 const struct mtd_partition *parts,
503 int nr_parts)
504{
505 int err;
506 struct mtd_partition *real_parts;
507
508 err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
509 if (err <= 0 && nr_parts && parts) {
510 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
511 GFP_KERNEL);
512 if (!real_parts)
513 err = -ENOMEM;
514 else
515 err = nr_parts;
516 }
517
518 if (err > 0) {
519 err = add_mtd_partitions(mtd, real_parts, err);
520 kfree(real_parts);
521 } else if (err == 0) {
522 err = add_mtd_device(mtd);
523 if (err == 1)
524 err = -ENODEV;
525 }
526
527 return err;
528}
529EXPORT_SYMBOL_GPL(mtd_device_parse_register);
530
531/**
532 * mtd_device_unregister - unregister an existing MTD device.
533 *
534 * @master: the MTD device to unregister. This will unregister both the master
535 * and any partitions if registered.
536 */
537int mtd_device_unregister(struct mtd_info *master)
538{
539 int err;
540
541 err = del_mtd_partitions(master);
542 if (err)
543 return err;
544
545 if (!device_is_registered(&master->dev))
546 return 0;
547
548 return del_mtd_device(master);
549}
550EXPORT_SYMBOL_GPL(mtd_device_unregister);
551
552/**
553 * register_mtd_user - register a 'user' of MTD devices.
554 * @new: pointer to notifier info structure
555 *
556 * Registers a pair of callbacks function to be called upon addition
557 * or removal of MTD devices. Causes the 'add' callback to be immediately
558 * invoked for each MTD device currently present in the system.
559 */
560void register_mtd_user (struct mtd_notifier *new)
561{
562 struct mtd_info *mtd;
563
564 mutex_lock(&mtd_table_mutex);
565
566 list_add(&new->list, &mtd_notifiers);
567
568 __module_get(THIS_MODULE);
569
570 mtd_for_each_device(mtd)
571 new->add(mtd);
572
573 mutex_unlock(&mtd_table_mutex);
574}
575EXPORT_SYMBOL_GPL(register_mtd_user);
576
577/**
578 * unregister_mtd_user - unregister a 'user' of MTD devices.
579 * @old: pointer to notifier info structure
580 *
581 * Removes a callback function pair from the list of 'users' to be
582 * notified upon addition or removal of MTD devices. Causes the
583 * 'remove' callback to be immediately invoked for each MTD device
584 * currently present in the system.
585 */
586int unregister_mtd_user (struct mtd_notifier *old)
587{
588 struct mtd_info *mtd;
589
590 mutex_lock(&mtd_table_mutex);
591
592 module_put(THIS_MODULE);
593
594 mtd_for_each_device(mtd)
595 old->remove(mtd);
596
597 list_del(&old->list);
598 mutex_unlock(&mtd_table_mutex);
599 return 0;
600}
601EXPORT_SYMBOL_GPL(unregister_mtd_user);
602
603/**
604 * get_mtd_device - obtain a validated handle for an MTD device
605 * @mtd: last known address of the required MTD device
606 * @num: internal device number of the required MTD device
607 *
608 * Given a number and NULL address, return the num'th entry in the device
609 * table, if any. Given an address and num == -1, search the device table
610 * for a device with that address and return if it's still present. Given
611 * both, return the num'th driver only if its address matches. Return
612 * error code if not.
613 */
614struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
615{
616 struct mtd_info *ret = NULL, *other;
617 int err = -ENODEV;
618
619 mutex_lock(&mtd_table_mutex);
620
621 if (num == -1) {
622 mtd_for_each_device(other) {
623 if (other == mtd) {
624 ret = mtd;
625 break;
626 }
627 }
628 } else if (num >= 0) {
629 ret = idr_find(&mtd_idr, num);
630 if (mtd && mtd != ret)
631 ret = NULL;
632 }
633
634 if (!ret) {
635 ret = ERR_PTR(err);
636 goto out;
637 }
638
639 err = __get_mtd_device(ret);
640 if (err)
641 ret = ERR_PTR(err);
642out:
643 mutex_unlock(&mtd_table_mutex);
644 return ret;
645}
646EXPORT_SYMBOL_GPL(get_mtd_device);
647
648
649int __get_mtd_device(struct mtd_info *mtd)
650{
651 int err;
652
653 if (!try_module_get(mtd->owner))
654 return -ENODEV;
655
656 if (mtd->_get_device) {
657 err = mtd->_get_device(mtd);
658
659 if (err) {
660 module_put(mtd->owner);
661 return err;
662 }
663 }
664 mtd->usecount++;
665 return 0;
666}
667EXPORT_SYMBOL_GPL(__get_mtd_device);
668
669/**
670 * get_mtd_device_nm - obtain a validated handle for an MTD device by
671 * device name
672 * @name: MTD device name to open
673 *
674 * This function returns MTD device description structure in case of
675 * success and an error code in case of failure.
676 */
677struct mtd_info *get_mtd_device_nm(const char *name)
678{
679 int err = -ENODEV;
680 struct mtd_info *mtd = NULL, *other;
681
682 mutex_lock(&mtd_table_mutex);
683
684 mtd_for_each_device(other) {
685 if (!strcmp(name, other->name)) {
686 mtd = other;
687 break;
688 }
689 }
690
691 if (!mtd)
692 goto out_unlock;
693
694 err = __get_mtd_device(mtd);
695 if (err)
696 goto out_unlock;
697
698 mutex_unlock(&mtd_table_mutex);
699 return mtd;
700
701out_unlock:
702 mutex_unlock(&mtd_table_mutex);
703 return ERR_PTR(err);
704}
705EXPORT_SYMBOL_GPL(get_mtd_device_nm);
706
707void put_mtd_device(struct mtd_info *mtd)
708{
709 mutex_lock(&mtd_table_mutex);
710 __put_mtd_device(mtd);
711 mutex_unlock(&mtd_table_mutex);
712
713}
714EXPORT_SYMBOL_GPL(put_mtd_device);
715
716void __put_mtd_device(struct mtd_info *mtd)
717{
718 --mtd->usecount;
719 BUG_ON(mtd->usecount < 0);
720
721 if (mtd->_put_device)
722 mtd->_put_device(mtd);
723
724 module_put(mtd->owner);
725}
726EXPORT_SYMBOL_GPL(__put_mtd_device);
727
728/*
729 * Erase is an asynchronous operation. Device drivers are supposed
730 * to call instr->callback() whenever the operation completes, even
731 * if it completes with a failure.
732 * Callers are supposed to pass a callback function and wait for it
733 * to be called before writing to the block.
734 */
735int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
736{
737 if (instr->addr > mtd->size || instr->len > mtd->size - instr->addr)
738 return -EINVAL;
739 if (!(mtd->flags & MTD_WRITEABLE))
740 return -EROFS;
741 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
742 if (!instr->len) {
743 instr->state = MTD_ERASE_DONE;
744 mtd_erase_callback(instr);
745 return 0;
746 }
747 return mtd->_erase(mtd, instr);
748}
749EXPORT_SYMBOL_GPL(mtd_erase);
750
751/*
752 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
753 */
754int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
755 void **virt, resource_size_t *phys)
756{
757 *retlen = 0;
758 *virt = NULL;
759 if (phys)
760 *phys = 0;
761 if (!mtd->_point)
762 return -EOPNOTSUPP;
763 if (from < 0 || from > mtd->size || len > mtd->size - from)
764 return -EINVAL;
765 if (!len)
766 return 0;
767 return mtd->_point(mtd, from, len, retlen, virt, phys);
768}
769EXPORT_SYMBOL_GPL(mtd_point);
770
771/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
772int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
773{
774 if (!mtd->_point)
775 return -EOPNOTSUPP;
776 if (from < 0 || from > mtd->size || len > mtd->size - from)
777 return -EINVAL;
778 if (!len)
779 return 0;
780 return mtd->_unpoint(mtd, from, len);
781}
782EXPORT_SYMBOL_GPL(mtd_unpoint);
783
784/*
785 * Allow NOMMU mmap() to directly map the device (if not NULL)
786 * - return the address to which the offset maps
787 * - return -ENOSYS to indicate refusal to do the mapping
788 */
789unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
790 unsigned long offset, unsigned long flags)
791{
792 if (!mtd->_get_unmapped_area)
793 return -EOPNOTSUPP;
794 if (offset > mtd->size || len > mtd->size - offset)
795 return -EINVAL;
796 return mtd->_get_unmapped_area(mtd, len, offset, flags);
797}
798EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
799
800int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
801 u_char *buf)
802{
803 int ret_code;
804 *retlen = 0;
805 if (from < 0 || from > mtd->size || len > mtd->size - from)
806 return -EINVAL;
807 if (!len)
808 return 0;
809
810 /*
811 * In the absence of an error, drivers return a non-negative integer
812 * representing the maximum number of bitflips that were corrected on
813 * any one ecc region (if applicable; zero otherwise).
814 */
815 ret_code = mtd->_read(mtd, from, len, retlen, buf);
816 if (unlikely(ret_code < 0))
817 return ret_code;
818 if (mtd->ecc_strength == 0)
819 return 0; /* device lacks ecc */
820 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
821}
822EXPORT_SYMBOL_GPL(mtd_read);
823
824int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
825 const u_char *buf)
826{
827 *retlen = 0;
828 if (to < 0 || to > mtd->size || len > mtd->size - to)
829 return -EINVAL;
830 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
831 return -EROFS;
832 if (!len)
833 return 0;
834 return mtd->_write(mtd, to, len, retlen, buf);
835}
836EXPORT_SYMBOL_GPL(mtd_write);
837
838/*
839 * In blackbox flight recorder like scenarios we want to make successful writes
840 * in interrupt context. panic_write() is only intended to be called when its
841 * known the kernel is about to panic and we need the write to succeed. Since
842 * the kernel is not going to be running for much longer, this function can
843 * break locks and delay to ensure the write succeeds (but not sleep).
844 */
845int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
846 const u_char *buf)
847{
848 *retlen = 0;
849 if (!mtd->_panic_write)
850 return -EOPNOTSUPP;
851 if (to < 0 || to > mtd->size || len > mtd->size - to)
852 return -EINVAL;
853 if (!(mtd->flags & MTD_WRITEABLE))
854 return -EROFS;
855 if (!len)
856 return 0;
857 return mtd->_panic_write(mtd, to, len, retlen, buf);
858}
859EXPORT_SYMBOL_GPL(mtd_panic_write);
860
861/*
862 * Method to access the protection register area, present in some flash
863 * devices. The user data is one time programmable but the factory data is read
864 * only.
865 */
866int mtd_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
867 size_t len)
868{
869 if (!mtd->_get_fact_prot_info)
870 return -EOPNOTSUPP;
871 if (!len)
872 return 0;
873 return mtd->_get_fact_prot_info(mtd, buf, len);
874}
875EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
876
877int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
878 size_t *retlen, u_char *buf)
879{
880 *retlen = 0;
881 if (!mtd->_read_fact_prot_reg)
882 return -EOPNOTSUPP;
883 if (!len)
884 return 0;
885 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
886}
887EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
888
889int mtd_get_user_prot_info(struct mtd_info *mtd, struct otp_info *buf,
890 size_t len)
891{
892 if (!mtd->_get_user_prot_info)
893 return -EOPNOTSUPP;
894 if (!len)
895 return 0;
896 return mtd->_get_user_prot_info(mtd, buf, len);
897}
898EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
899
900int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
901 size_t *retlen, u_char *buf)
902{
903 *retlen = 0;
904 if (!mtd->_read_user_prot_reg)
905 return -EOPNOTSUPP;
906 if (!len)
907 return 0;
908 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
909}
910EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
911
912int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
913 size_t *retlen, u_char *buf)
914{
915 *retlen = 0;
916 if (!mtd->_write_user_prot_reg)
917 return -EOPNOTSUPP;
918 if (!len)
919 return 0;
920 return mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
921}
922EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
923
924int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
925{
926 if (!mtd->_lock_user_prot_reg)
927 return -EOPNOTSUPP;
928 if (!len)
929 return 0;
930 return mtd->_lock_user_prot_reg(mtd, from, len);
931}
932EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
933
934/* Chip-supported device locking */
935int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
936{
937 if (!mtd->_lock)
938 return -EOPNOTSUPP;
939 if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
940 return -EINVAL;
941 if (!len)
942 return 0;
943 return mtd->_lock(mtd, ofs, len);
944}
945EXPORT_SYMBOL_GPL(mtd_lock);
946
947int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
948{
949 if (!mtd->_unlock)
950 return -EOPNOTSUPP;
951 if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
952 return -EINVAL;
953 if (!len)
954 return 0;
955 return mtd->_unlock(mtd, ofs, len);
956}
957EXPORT_SYMBOL_GPL(mtd_unlock);
958
959int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
960{
961 if (!mtd->_is_locked)
962 return -EOPNOTSUPP;
963 if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
964 return -EINVAL;
965 if (!len)
966 return 0;
967 return mtd->_is_locked(mtd, ofs, len);
968}
969EXPORT_SYMBOL_GPL(mtd_is_locked);
970
971int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
972{
973 if (!mtd->_block_isbad)
974 return 0;
975 if (ofs < 0 || ofs > mtd->size)
976 return -EINVAL;
977 return mtd->_block_isbad(mtd, ofs);
978}
979EXPORT_SYMBOL_GPL(mtd_block_isbad);
980
981int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
982{
983 if (!mtd->_block_markbad)
984 return -EOPNOTSUPP;
985 if (ofs < 0 || ofs > mtd->size)
986 return -EINVAL;
987 if (!(mtd->flags & MTD_WRITEABLE))
988 return -EROFS;
989 return mtd->_block_markbad(mtd, ofs);
990}
991EXPORT_SYMBOL_GPL(mtd_block_markbad);
992
993/*
994 * default_mtd_writev - the default writev method
995 * @mtd: mtd device description object pointer
996 * @vecs: the vectors to write
997 * @count: count of vectors in @vecs
998 * @to: the MTD device offset to write to
999 * @retlen: on exit contains the count of bytes written to the MTD device.
1000 *
1001 * This function returns zero in case of success and a negative error code in
1002 * case of failure.
1003 */
1004static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1005 unsigned long count, loff_t to, size_t *retlen)
1006{
1007 unsigned long i;
1008 size_t totlen = 0, thislen;
1009 int ret = 0;
1010
1011 for (i = 0; i < count; i++) {
1012 if (!vecs[i].iov_len)
1013 continue;
1014 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1015 vecs[i].iov_base);
1016 totlen += thislen;
1017 if (ret || thislen != vecs[i].iov_len)
1018 break;
1019 to += vecs[i].iov_len;
1020 }
1021 *retlen = totlen;
1022 return ret;
1023}
1024
1025/*
1026 * mtd_writev - the vector-based MTD write method
1027 * @mtd: mtd device description object pointer
1028 * @vecs: the vectors to write
1029 * @count: count of vectors in @vecs
1030 * @to: the MTD device offset to write to
1031 * @retlen: on exit contains the count of bytes written to the MTD device.
1032 *
1033 * This function returns zero in case of success and a negative error code in
1034 * case of failure.
1035 */
1036int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1037 unsigned long count, loff_t to, size_t *retlen)
1038{
1039 *retlen = 0;
1040 if (!(mtd->flags & MTD_WRITEABLE))
1041 return -EROFS;
1042 if (!mtd->_writev)
1043 return default_mtd_writev(mtd, vecs, count, to, retlen);
1044 return mtd->_writev(mtd, vecs, count, to, retlen);
1045}
1046EXPORT_SYMBOL_GPL(mtd_writev);
1047
1048/**
1049 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1050 * @mtd: mtd device description object pointer
1051 * @size: a pointer to the ideal or maximum size of the allocation, points
1052 * to the actual allocation size on success.
1053 *
1054 * This routine attempts to allocate a contiguous kernel buffer up to
1055 * the specified size, backing off the size of the request exponentially
1056 * until the request succeeds or until the allocation size falls below
1057 * the system page size. This attempts to make sure it does not adversely
1058 * impact system performance, so when allocating more than one page, we
1059 * ask the memory allocator to avoid re-trying, swapping, writing back
1060 * or performing I/O.
1061 *
1062 * Note, this function also makes sure that the allocated buffer is aligned to
1063 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1064 *
1065 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1066 * to handle smaller (i.e. degraded) buffer allocations under low- or
1067 * fragmented-memory situations where such reduced allocations, from a
1068 * requested ideal, are allowed.
1069 *
1070 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1071 */
1072void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1073{
1074 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
1075 __GFP_NORETRY | __GFP_NO_KSWAPD;
1076 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1077 void *kbuf;
1078
1079 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1080
1081 while (*size > min_alloc) {
1082 kbuf = kmalloc(*size, flags);
1083 if (kbuf)
1084 return kbuf;
1085
1086 *size >>= 1;
1087 *size = ALIGN(*size, mtd->writesize);
1088 }
1089
1090 /*
1091 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1092 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1093 */
1094 return kmalloc(*size, GFP_KERNEL);
1095}
1096EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1097
1098#ifdef CONFIG_PROC_FS
1099
1100/*====================================================================*/
1101/* Support for /proc/mtd */
1102
1103static struct proc_dir_entry *proc_mtd;
1104
1105static int mtd_proc_show(struct seq_file *m, void *v)
1106{
1107 struct mtd_info *mtd;
1108
1109 seq_puts(m, "dev: size erasesize name\n");
1110 mutex_lock(&mtd_table_mutex);
1111 mtd_for_each_device(mtd) {
1112 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1113 mtd->index, (unsigned long long)mtd->size,
1114 mtd->erasesize, mtd->name);
1115 }
1116 mutex_unlock(&mtd_table_mutex);
1117 return 0;
1118}
1119
1120static int mtd_proc_open(struct inode *inode, struct file *file)
1121{
1122 return single_open(file, mtd_proc_show, NULL);
1123}
1124
1125static const struct file_operations mtd_proc_ops = {
1126 .open = mtd_proc_open,
1127 .read = seq_read,
1128 .llseek = seq_lseek,
1129 .release = single_release,
1130};
1131#endif /* CONFIG_PROC_FS */
1132
1133/*====================================================================*/
1134/* Init code */
1135
1136static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1137{
1138 int ret;
1139
1140 ret = bdi_init(bdi);
1141 if (!ret)
1142 ret = bdi_register(bdi, NULL, name);
1143
1144 if (ret)
1145 bdi_destroy(bdi);
1146
1147 return ret;
1148}
1149
1150static int __init init_mtd(void)
1151{
1152 int ret;
1153
1154 ret = class_register(&mtd_class);
1155 if (ret)
1156 goto err_reg;
1157
1158 ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
1159 if (ret)
1160 goto err_bdi1;
1161
1162 ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
1163 if (ret)
1164 goto err_bdi2;
1165
1166 ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
1167 if (ret)
1168 goto err_bdi3;
1169
1170#ifdef CONFIG_PROC_FS
1171 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1172#endif /* CONFIG_PROC_FS */
1173 return 0;
1174
1175err_bdi3:
1176 bdi_destroy(&mtd_bdi_ro_mappable);
1177err_bdi2:
1178 bdi_destroy(&mtd_bdi_unmappable);
1179err_bdi1:
1180 class_unregister(&mtd_class);
1181err_reg:
1182 pr_err("Error registering mtd class or bdi: %d\n", ret);
1183 return ret;
1184}
1185
1186static void __exit cleanup_mtd(void)
1187{
1188#ifdef CONFIG_PROC_FS
1189 if (proc_mtd)
1190 remove_proc_entry( "mtd", NULL);
1191#endif /* CONFIG_PROC_FS */
1192 class_unregister(&mtd_class);
1193 bdi_destroy(&mtd_bdi_unmappable);
1194 bdi_destroy(&mtd_bdi_ro_mappable);
1195 bdi_destroy(&mtd_bdi_rw_mappable);
1196}
1197
1198module_init(init_mtd);
1199module_exit(cleanup_mtd);
1200
1201MODULE_LICENSE("GPL");
1202MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1203MODULE_DESCRIPTION("Core MTD registration and access routines");