Loading...
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/of.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>
43
44#include <linux/mtd/mtd.h>
45#include <linux/mtd/partitions.h>
46
47#include "mtdcore.h"
48
49static struct backing_dev_info mtd_bdi = {
50};
51
52#ifdef CONFIG_PM_SLEEP
53
54static int mtd_cls_suspend(struct device *dev)
55{
56 struct mtd_info *mtd = dev_get_drvdata(dev);
57
58 return mtd ? mtd_suspend(mtd) : 0;
59}
60
61static int mtd_cls_resume(struct device *dev)
62{
63 struct mtd_info *mtd = dev_get_drvdata(dev);
64
65 if (mtd)
66 mtd_resume(mtd);
67 return 0;
68}
69
70static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
71#define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
72#else
73#define MTD_CLS_PM_OPS NULL
74#endif
75
76static struct class mtd_class = {
77 .name = "mtd",
78 .owner = THIS_MODULE,
79 .pm = MTD_CLS_PM_OPS,
80};
81
82static DEFINE_IDR(mtd_idr);
83
84/* These are exported solely for the purpose of mtd_blkdevs.c. You
85 should not use them for _anything_ else */
86DEFINE_MUTEX(mtd_table_mutex);
87EXPORT_SYMBOL_GPL(mtd_table_mutex);
88
89struct mtd_info *__mtd_next_device(int i)
90{
91 return idr_get_next(&mtd_idr, &i);
92}
93EXPORT_SYMBOL_GPL(__mtd_next_device);
94
95static LIST_HEAD(mtd_notifiers);
96
97
98#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
99
100/* REVISIT once MTD uses the driver model better, whoever allocates
101 * the mtd_info will probably want to use the release() hook...
102 */
103static void mtd_release(struct device *dev)
104{
105 struct mtd_info *mtd = dev_get_drvdata(dev);
106 dev_t index = MTD_DEVT(mtd->index);
107
108 /* remove /dev/mtdXro node */
109 device_destroy(&mtd_class, index + 1);
110}
111
112static ssize_t mtd_type_show(struct device *dev,
113 struct device_attribute *attr, char *buf)
114{
115 struct mtd_info *mtd = dev_get_drvdata(dev);
116 char *type;
117
118 switch (mtd->type) {
119 case MTD_ABSENT:
120 type = "absent";
121 break;
122 case MTD_RAM:
123 type = "ram";
124 break;
125 case MTD_ROM:
126 type = "rom";
127 break;
128 case MTD_NORFLASH:
129 type = "nor";
130 break;
131 case MTD_NANDFLASH:
132 type = "nand";
133 break;
134 case MTD_DATAFLASH:
135 type = "dataflash";
136 break;
137 case MTD_UBIVOLUME:
138 type = "ubi";
139 break;
140 case MTD_MLCNANDFLASH:
141 type = "mlc-nand";
142 break;
143 default:
144 type = "unknown";
145 }
146
147 return snprintf(buf, PAGE_SIZE, "%s\n", type);
148}
149static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
150
151static ssize_t mtd_flags_show(struct device *dev,
152 struct device_attribute *attr, char *buf)
153{
154 struct mtd_info *mtd = dev_get_drvdata(dev);
155
156 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
157
158}
159static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
160
161static ssize_t mtd_size_show(struct device *dev,
162 struct device_attribute *attr, char *buf)
163{
164 struct mtd_info *mtd = dev_get_drvdata(dev);
165
166 return snprintf(buf, PAGE_SIZE, "%llu\n",
167 (unsigned long long)mtd->size);
168
169}
170static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
171
172static ssize_t mtd_erasesize_show(struct device *dev,
173 struct device_attribute *attr, char *buf)
174{
175 struct mtd_info *mtd = dev_get_drvdata(dev);
176
177 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
178
179}
180static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
181
182static ssize_t mtd_writesize_show(struct device *dev,
183 struct device_attribute *attr, char *buf)
184{
185 struct mtd_info *mtd = dev_get_drvdata(dev);
186
187 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
188
189}
190static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
191
192static ssize_t mtd_subpagesize_show(struct device *dev,
193 struct device_attribute *attr, char *buf)
194{
195 struct mtd_info *mtd = dev_get_drvdata(dev);
196 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
197
198 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
199
200}
201static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
202
203static ssize_t mtd_oobsize_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
205{
206 struct mtd_info *mtd = dev_get_drvdata(dev);
207
208 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
209
210}
211static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
212
213static ssize_t mtd_numeraseregions_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
215{
216 struct mtd_info *mtd = dev_get_drvdata(dev);
217
218 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
219
220}
221static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
222 NULL);
223
224static ssize_t mtd_name_show(struct device *dev,
225 struct device_attribute *attr, char *buf)
226{
227 struct mtd_info *mtd = dev_get_drvdata(dev);
228
229 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
230
231}
232static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
233
234static ssize_t mtd_ecc_strength_show(struct device *dev,
235 struct device_attribute *attr, char *buf)
236{
237 struct mtd_info *mtd = dev_get_drvdata(dev);
238
239 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
240}
241static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
242
243static ssize_t mtd_bitflip_threshold_show(struct device *dev,
244 struct device_attribute *attr,
245 char *buf)
246{
247 struct mtd_info *mtd = dev_get_drvdata(dev);
248
249 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
250}
251
252static ssize_t mtd_bitflip_threshold_store(struct device *dev,
253 struct device_attribute *attr,
254 const char *buf, size_t count)
255{
256 struct mtd_info *mtd = dev_get_drvdata(dev);
257 unsigned int bitflip_threshold;
258 int retval;
259
260 retval = kstrtouint(buf, 0, &bitflip_threshold);
261 if (retval)
262 return retval;
263
264 mtd->bitflip_threshold = bitflip_threshold;
265 return count;
266}
267static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
268 mtd_bitflip_threshold_show,
269 mtd_bitflip_threshold_store);
270
271static ssize_t mtd_ecc_step_size_show(struct device *dev,
272 struct device_attribute *attr, char *buf)
273{
274 struct mtd_info *mtd = dev_get_drvdata(dev);
275
276 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
277
278}
279static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
280
281static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
282 struct device_attribute *attr, char *buf)
283{
284 struct mtd_info *mtd = dev_get_drvdata(dev);
285 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
286
287 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
288}
289static DEVICE_ATTR(corrected_bits, S_IRUGO,
290 mtd_ecc_stats_corrected_show, NULL);
291
292static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
293 struct device_attribute *attr, char *buf)
294{
295 struct mtd_info *mtd = dev_get_drvdata(dev);
296 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
297
298 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
299}
300static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
301
302static ssize_t mtd_badblocks_show(struct device *dev,
303 struct device_attribute *attr, char *buf)
304{
305 struct mtd_info *mtd = dev_get_drvdata(dev);
306 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
307
308 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
309}
310static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
311
312static ssize_t mtd_bbtblocks_show(struct device *dev,
313 struct device_attribute *attr, char *buf)
314{
315 struct mtd_info *mtd = dev_get_drvdata(dev);
316 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
317
318 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
319}
320static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
321
322static struct attribute *mtd_attrs[] = {
323 &dev_attr_type.attr,
324 &dev_attr_flags.attr,
325 &dev_attr_size.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,
331 &dev_attr_name.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,
339 NULL,
340};
341ATTRIBUTE_GROUPS(mtd);
342
343static struct device_type mtd_devtype = {
344 .name = "mtd",
345 .groups = mtd_groups,
346 .release = mtd_release,
347};
348
349#ifndef CONFIG_MMU
350unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
351{
352 switch (mtd->type) {
353 case MTD_RAM:
354 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
355 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
356 case MTD_ROM:
357 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
358 NOMMU_MAP_READ;
359 default:
360 return NOMMU_MAP_COPY;
361 }
362}
363EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
364#endif
365
366static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
367 void *cmd)
368{
369 struct mtd_info *mtd;
370
371 mtd = container_of(n, struct mtd_info, reboot_notifier);
372 mtd->_reboot(mtd);
373
374 return NOTIFY_DONE;
375}
376
377/**
378 * add_mtd_device - register an MTD device
379 * @mtd: pointer to new MTD device info structure
380 *
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.
384 */
385
386int add_mtd_device(struct mtd_info *mtd)
387{
388 struct mtd_notifier *not;
389 int i, error;
390
391 /*
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.
395 */
396 if (WARN_ONCE(mtd->backing_dev_info, "MTD already registered\n"))
397 return -EEXIST;
398
399 mtd->backing_dev_info = &mtd_bdi;
400
401 BUG_ON(mtd->writesize == 0);
402 mutex_lock(&mtd_table_mutex);
403
404 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
405 if (i < 0) {
406 error = i;
407 goto fail_locked;
408 }
409
410 mtd->index = i;
411 mtd->usecount = 0;
412
413 /* default value if not set by driver */
414 if (mtd->bitflip_threshold == 0)
415 mtd->bitflip_threshold = mtd->ecc_strength;
416
417 if (is_power_of_2(mtd->erasesize))
418 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
419 else
420 mtd->erasesize_shift = 0;
421
422 if (is_power_of_2(mtd->writesize))
423 mtd->writesize_shift = ffs(mtd->writesize) - 1;
424 else
425 mtd->writesize_shift = 0;
426
427 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
428 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
429
430 /* Some chips always power up locked. Unlock them now */
431 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
432 error = mtd_unlock(mtd, 0, mtd->size);
433 if (error && error != -EOPNOTSUPP)
434 printk(KERN_WARNING
435 "%s: unlock failed, writes may not work\n",
436 mtd->name);
437 /* Ignore unlock failures? */
438 error = 0;
439 }
440
441 /* Caller should have set dev.parent to match the
442 * physical device, if appropriate.
443 */
444 mtd->dev.type = &mtd_devtype;
445 mtd->dev.class = &mtd_class;
446 mtd->dev.devt = MTD_DEVT(i);
447 dev_set_name(&mtd->dev, "mtd%d", i);
448 dev_set_drvdata(&mtd->dev, mtd);
449 of_node_get(mtd_get_of_node(mtd));
450 error = device_register(&mtd->dev);
451 if (error)
452 goto fail_added;
453
454 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
455 "mtd%dro", i);
456
457 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
458 /* No need to get a refcount on the module containing
459 the notifier, since we hold the mtd_table_mutex */
460 list_for_each_entry(not, &mtd_notifiers, list)
461 not->add(mtd);
462
463 mutex_unlock(&mtd_table_mutex);
464 /* We _know_ we aren't being removed, because
465 our caller is still holding us here. So none
466 of this try_ nonsense, and no bitching about it
467 either. :) */
468 __module_get(THIS_MODULE);
469 return 0;
470
471fail_added:
472 of_node_put(mtd_get_of_node(mtd));
473 idr_remove(&mtd_idr, i);
474fail_locked:
475 mutex_unlock(&mtd_table_mutex);
476 return error;
477}
478
479/**
480 * del_mtd_device - unregister an MTD device
481 * @mtd: pointer to MTD device info structure
482 *
483 * Remove a device from the list of MTD devices present in the system,
484 * and notify each currently active MTD 'user' of its departure.
485 * Returns zero on success or 1 on failure, which currently will happen
486 * if the requested device does not appear to be present in the list.
487 */
488
489int del_mtd_device(struct mtd_info *mtd)
490{
491 int ret;
492 struct mtd_notifier *not;
493
494 mutex_lock(&mtd_table_mutex);
495
496 if (idr_find(&mtd_idr, mtd->index) != mtd) {
497 ret = -ENODEV;
498 goto out_error;
499 }
500
501 /* No need to get a refcount on the module containing
502 the notifier, since we hold the mtd_table_mutex */
503 list_for_each_entry(not, &mtd_notifiers, list)
504 not->remove(mtd);
505
506 if (mtd->usecount) {
507 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
508 mtd->index, mtd->name, mtd->usecount);
509 ret = -EBUSY;
510 } else {
511 device_unregister(&mtd->dev);
512
513 idr_remove(&mtd_idr, mtd->index);
514 of_node_put(mtd_get_of_node(mtd));
515
516 module_put(THIS_MODULE);
517 ret = 0;
518 }
519
520out_error:
521 mutex_unlock(&mtd_table_mutex);
522 return ret;
523}
524
525static int mtd_add_device_partitions(struct mtd_info *mtd,
526 struct mtd_partitions *parts)
527{
528 const struct mtd_partition *real_parts = parts->parts;
529 int nbparts = parts->nr_parts;
530 int ret;
531
532 if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
533 ret = add_mtd_device(mtd);
534 if (ret)
535 return ret;
536 }
537
538 if (nbparts > 0) {
539 ret = add_mtd_partitions(mtd, real_parts, nbparts);
540 if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
541 del_mtd_device(mtd);
542 return ret;
543 }
544
545 return 0;
546}
547
548/*
549 * Set a few defaults based on the parent devices, if not provided by the
550 * driver
551 */
552static void mtd_set_dev_defaults(struct mtd_info *mtd)
553{
554 if (mtd->dev.parent) {
555 if (!mtd->owner && mtd->dev.parent->driver)
556 mtd->owner = mtd->dev.parent->driver->owner;
557 if (!mtd->name)
558 mtd->name = dev_name(mtd->dev.parent);
559 } else {
560 pr_debug("mtd device won't show a device symlink in sysfs\n");
561 }
562}
563
564/**
565 * mtd_device_parse_register - parse partitions and register an MTD device.
566 *
567 * @mtd: the MTD device to register
568 * @types: the list of MTD partition probes to try, see
569 * 'parse_mtd_partitions()' for more information
570 * @parser_data: MTD partition parser-specific data
571 * @parts: fallback partition information to register, if parsing fails;
572 * only valid if %nr_parts > %0
573 * @nr_parts: the number of partitions in parts, if zero then the full
574 * MTD device is registered if no partition info is found
575 *
576 * This function aggregates MTD partitions parsing (done by
577 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
578 * basically follows the most common pattern found in many MTD drivers:
579 *
580 * * It first tries to probe partitions on MTD device @mtd using parsers
581 * specified in @types (if @types is %NULL, then the default list of parsers
582 * is used, see 'parse_mtd_partitions()' for more information). If none are
583 * found this functions tries to fallback to information specified in
584 * @parts/@nr_parts.
585 * * If any partitioning info was found, this function registers the found
586 * partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
587 * as a whole is registered first.
588 * * If no partitions were found this function just registers the MTD device
589 * @mtd and exits.
590 *
591 * Returns zero in case of success and a negative error code in case of failure.
592 */
593int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
594 struct mtd_part_parser_data *parser_data,
595 const struct mtd_partition *parts,
596 int nr_parts)
597{
598 struct mtd_partitions parsed;
599 int ret;
600
601 mtd_set_dev_defaults(mtd);
602
603 memset(&parsed, 0, sizeof(parsed));
604
605 ret = parse_mtd_partitions(mtd, types, &parsed, parser_data);
606 if ((ret < 0 || parsed.nr_parts == 0) && parts && nr_parts) {
607 /* Fall back to driver-provided partitions */
608 parsed = (struct mtd_partitions){
609 .parts = parts,
610 .nr_parts = nr_parts,
611 };
612 } else if (ret < 0) {
613 /* Didn't come up with parsed OR fallback partitions */
614 pr_info("mtd: failed to find partitions; one or more parsers reports errors (%d)\n",
615 ret);
616 /* Don't abort on errors; we can still use unpartitioned MTD */
617 memset(&parsed, 0, sizeof(parsed));
618 }
619
620 ret = mtd_add_device_partitions(mtd, &parsed);
621 if (ret)
622 goto out;
623
624 /*
625 * FIXME: some drivers unfortunately call this function more than once.
626 * So we have to check if we've already assigned the reboot notifier.
627 *
628 * Generally, we can make multiple calls work for most cases, but it
629 * does cause problems with parse_mtd_partitions() above (e.g.,
630 * cmdlineparts will register partitions more than once).
631 */
632 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
633 "MTD already registered\n");
634 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
635 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
636 register_reboot_notifier(&mtd->reboot_notifier);
637 }
638
639out:
640 /* Cleanup any parsed partitions */
641 mtd_part_parser_cleanup(&parsed);
642 return ret;
643}
644EXPORT_SYMBOL_GPL(mtd_device_parse_register);
645
646/**
647 * mtd_device_unregister - unregister an existing MTD device.
648 *
649 * @master: the MTD device to unregister. This will unregister both the master
650 * and any partitions if registered.
651 */
652int mtd_device_unregister(struct mtd_info *master)
653{
654 int err;
655
656 if (master->_reboot)
657 unregister_reboot_notifier(&master->reboot_notifier);
658
659 err = del_mtd_partitions(master);
660 if (err)
661 return err;
662
663 if (!device_is_registered(&master->dev))
664 return 0;
665
666 return del_mtd_device(master);
667}
668EXPORT_SYMBOL_GPL(mtd_device_unregister);
669
670/**
671 * register_mtd_user - register a 'user' of MTD devices.
672 * @new: pointer to notifier info structure
673 *
674 * Registers a pair of callbacks function to be called upon addition
675 * or removal of MTD devices. Causes the 'add' callback to be immediately
676 * invoked for each MTD device currently present in the system.
677 */
678void register_mtd_user (struct mtd_notifier *new)
679{
680 struct mtd_info *mtd;
681
682 mutex_lock(&mtd_table_mutex);
683
684 list_add(&new->list, &mtd_notifiers);
685
686 __module_get(THIS_MODULE);
687
688 mtd_for_each_device(mtd)
689 new->add(mtd);
690
691 mutex_unlock(&mtd_table_mutex);
692}
693EXPORT_SYMBOL_GPL(register_mtd_user);
694
695/**
696 * unregister_mtd_user - unregister a 'user' of MTD devices.
697 * @old: pointer to notifier info structure
698 *
699 * Removes a callback function pair from the list of 'users' to be
700 * notified upon addition or removal of MTD devices. Causes the
701 * 'remove' callback to be immediately invoked for each MTD device
702 * currently present in the system.
703 */
704int unregister_mtd_user (struct mtd_notifier *old)
705{
706 struct mtd_info *mtd;
707
708 mutex_lock(&mtd_table_mutex);
709
710 module_put(THIS_MODULE);
711
712 mtd_for_each_device(mtd)
713 old->remove(mtd);
714
715 list_del(&old->list);
716 mutex_unlock(&mtd_table_mutex);
717 return 0;
718}
719EXPORT_SYMBOL_GPL(unregister_mtd_user);
720
721/**
722 * get_mtd_device - obtain a validated handle for an MTD device
723 * @mtd: last known address of the required MTD device
724 * @num: internal device number of the required MTD device
725 *
726 * Given a number and NULL address, return the num'th entry in the device
727 * table, if any. Given an address and num == -1, search the device table
728 * for a device with that address and return if it's still present. Given
729 * both, return the num'th driver only if its address matches. Return
730 * error code if not.
731 */
732struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
733{
734 struct mtd_info *ret = NULL, *other;
735 int err = -ENODEV;
736
737 mutex_lock(&mtd_table_mutex);
738
739 if (num == -1) {
740 mtd_for_each_device(other) {
741 if (other == mtd) {
742 ret = mtd;
743 break;
744 }
745 }
746 } else if (num >= 0) {
747 ret = idr_find(&mtd_idr, num);
748 if (mtd && mtd != ret)
749 ret = NULL;
750 }
751
752 if (!ret) {
753 ret = ERR_PTR(err);
754 goto out;
755 }
756
757 err = __get_mtd_device(ret);
758 if (err)
759 ret = ERR_PTR(err);
760out:
761 mutex_unlock(&mtd_table_mutex);
762 return ret;
763}
764EXPORT_SYMBOL_GPL(get_mtd_device);
765
766
767int __get_mtd_device(struct mtd_info *mtd)
768{
769 int err;
770
771 if (!try_module_get(mtd->owner))
772 return -ENODEV;
773
774 if (mtd->_get_device) {
775 err = mtd->_get_device(mtd);
776
777 if (err) {
778 module_put(mtd->owner);
779 return err;
780 }
781 }
782 mtd->usecount++;
783 return 0;
784}
785EXPORT_SYMBOL_GPL(__get_mtd_device);
786
787/**
788 * get_mtd_device_nm - obtain a validated handle for an MTD device by
789 * device name
790 * @name: MTD device name to open
791 *
792 * This function returns MTD device description structure in case of
793 * success and an error code in case of failure.
794 */
795struct mtd_info *get_mtd_device_nm(const char *name)
796{
797 int err = -ENODEV;
798 struct mtd_info *mtd = NULL, *other;
799
800 mutex_lock(&mtd_table_mutex);
801
802 mtd_for_each_device(other) {
803 if (!strcmp(name, other->name)) {
804 mtd = other;
805 break;
806 }
807 }
808
809 if (!mtd)
810 goto out_unlock;
811
812 err = __get_mtd_device(mtd);
813 if (err)
814 goto out_unlock;
815
816 mutex_unlock(&mtd_table_mutex);
817 return mtd;
818
819out_unlock:
820 mutex_unlock(&mtd_table_mutex);
821 return ERR_PTR(err);
822}
823EXPORT_SYMBOL_GPL(get_mtd_device_nm);
824
825void put_mtd_device(struct mtd_info *mtd)
826{
827 mutex_lock(&mtd_table_mutex);
828 __put_mtd_device(mtd);
829 mutex_unlock(&mtd_table_mutex);
830
831}
832EXPORT_SYMBOL_GPL(put_mtd_device);
833
834void __put_mtd_device(struct mtd_info *mtd)
835{
836 --mtd->usecount;
837 BUG_ON(mtd->usecount < 0);
838
839 if (mtd->_put_device)
840 mtd->_put_device(mtd);
841
842 module_put(mtd->owner);
843}
844EXPORT_SYMBOL_GPL(__put_mtd_device);
845
846/*
847 * Erase is an asynchronous operation. Device drivers are supposed
848 * to call instr->callback() whenever the operation completes, even
849 * if it completes with a failure.
850 * Callers are supposed to pass a callback function and wait for it
851 * to be called before writing to the block.
852 */
853int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
854{
855 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
856 return -EINVAL;
857 if (!(mtd->flags & MTD_WRITEABLE))
858 return -EROFS;
859 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
860 if (!instr->len) {
861 instr->state = MTD_ERASE_DONE;
862 mtd_erase_callback(instr);
863 return 0;
864 }
865 return mtd->_erase(mtd, instr);
866}
867EXPORT_SYMBOL_GPL(mtd_erase);
868
869/*
870 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
871 */
872int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
873 void **virt, resource_size_t *phys)
874{
875 *retlen = 0;
876 *virt = NULL;
877 if (phys)
878 *phys = 0;
879 if (!mtd->_point)
880 return -EOPNOTSUPP;
881 if (from < 0 || from >= mtd->size || len > mtd->size - from)
882 return -EINVAL;
883 if (!len)
884 return 0;
885 return mtd->_point(mtd, from, len, retlen, virt, phys);
886}
887EXPORT_SYMBOL_GPL(mtd_point);
888
889/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
890int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
891{
892 if (!mtd->_point)
893 return -EOPNOTSUPP;
894 if (from < 0 || from >= mtd->size || len > mtd->size - from)
895 return -EINVAL;
896 if (!len)
897 return 0;
898 return mtd->_unpoint(mtd, from, len);
899}
900EXPORT_SYMBOL_GPL(mtd_unpoint);
901
902/*
903 * Allow NOMMU mmap() to directly map the device (if not NULL)
904 * - return the address to which the offset maps
905 * - return -ENOSYS to indicate refusal to do the mapping
906 */
907unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
908 unsigned long offset, unsigned long flags)
909{
910 if (!mtd->_get_unmapped_area)
911 return -EOPNOTSUPP;
912 if (offset >= mtd->size || len > mtd->size - offset)
913 return -EINVAL;
914 return mtd->_get_unmapped_area(mtd, len, offset, flags);
915}
916EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
917
918int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
919 u_char *buf)
920{
921 int ret_code;
922 *retlen = 0;
923 if (from < 0 || from >= mtd->size || len > mtd->size - from)
924 return -EINVAL;
925 if (!len)
926 return 0;
927
928 /*
929 * In the absence of an error, drivers return a non-negative integer
930 * representing the maximum number of bitflips that were corrected on
931 * any one ecc region (if applicable; zero otherwise).
932 */
933 ret_code = mtd->_read(mtd, from, len, retlen, buf);
934 if (unlikely(ret_code < 0))
935 return ret_code;
936 if (mtd->ecc_strength == 0)
937 return 0; /* device lacks ecc */
938 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
939}
940EXPORT_SYMBOL_GPL(mtd_read);
941
942int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
943 const u_char *buf)
944{
945 *retlen = 0;
946 if (to < 0 || to >= mtd->size || len > mtd->size - to)
947 return -EINVAL;
948 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
949 return -EROFS;
950 if (!len)
951 return 0;
952 return mtd->_write(mtd, to, len, retlen, buf);
953}
954EXPORT_SYMBOL_GPL(mtd_write);
955
956/*
957 * In blackbox flight recorder like scenarios we want to make successful writes
958 * in interrupt context. panic_write() is only intended to be called when its
959 * known the kernel is about to panic and we need the write to succeed. Since
960 * the kernel is not going to be running for much longer, this function can
961 * break locks and delay to ensure the write succeeds (but not sleep).
962 */
963int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
964 const u_char *buf)
965{
966 *retlen = 0;
967 if (!mtd->_panic_write)
968 return -EOPNOTSUPP;
969 if (to < 0 || to >= mtd->size || len > mtd->size - to)
970 return -EINVAL;
971 if (!(mtd->flags & MTD_WRITEABLE))
972 return -EROFS;
973 if (!len)
974 return 0;
975 return mtd->_panic_write(mtd, to, len, retlen, buf);
976}
977EXPORT_SYMBOL_GPL(mtd_panic_write);
978
979int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
980{
981 int ret_code;
982 ops->retlen = ops->oobretlen = 0;
983 if (!mtd->_read_oob)
984 return -EOPNOTSUPP;
985 /*
986 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
987 * similar to mtd->_read(), returning a non-negative integer
988 * representing max bitflips. In other cases, mtd->_read_oob() may
989 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
990 */
991 ret_code = mtd->_read_oob(mtd, from, ops);
992 if (unlikely(ret_code < 0))
993 return ret_code;
994 if (mtd->ecc_strength == 0)
995 return 0; /* device lacks ecc */
996 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
997}
998EXPORT_SYMBOL_GPL(mtd_read_oob);
999
1000/*
1001 * Method to access the protection register area, present in some flash
1002 * devices. The user data is one time programmable but the factory data is read
1003 * only.
1004 */
1005int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1006 struct otp_info *buf)
1007{
1008 if (!mtd->_get_fact_prot_info)
1009 return -EOPNOTSUPP;
1010 if (!len)
1011 return 0;
1012 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1013}
1014EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1015
1016int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1017 size_t *retlen, u_char *buf)
1018{
1019 *retlen = 0;
1020 if (!mtd->_read_fact_prot_reg)
1021 return -EOPNOTSUPP;
1022 if (!len)
1023 return 0;
1024 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1025}
1026EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1027
1028int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1029 struct otp_info *buf)
1030{
1031 if (!mtd->_get_user_prot_info)
1032 return -EOPNOTSUPP;
1033 if (!len)
1034 return 0;
1035 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1036}
1037EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1038
1039int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1040 size_t *retlen, u_char *buf)
1041{
1042 *retlen = 0;
1043 if (!mtd->_read_user_prot_reg)
1044 return -EOPNOTSUPP;
1045 if (!len)
1046 return 0;
1047 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1048}
1049EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1050
1051int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1052 size_t *retlen, u_char *buf)
1053{
1054 int ret;
1055
1056 *retlen = 0;
1057 if (!mtd->_write_user_prot_reg)
1058 return -EOPNOTSUPP;
1059 if (!len)
1060 return 0;
1061 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1062 if (ret)
1063 return ret;
1064
1065 /*
1066 * If no data could be written at all, we are out of memory and
1067 * must return -ENOSPC.
1068 */
1069 return (*retlen) ? 0 : -ENOSPC;
1070}
1071EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1072
1073int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1074{
1075 if (!mtd->_lock_user_prot_reg)
1076 return -EOPNOTSUPP;
1077 if (!len)
1078 return 0;
1079 return mtd->_lock_user_prot_reg(mtd, from, len);
1080}
1081EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1082
1083/* Chip-supported device locking */
1084int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1085{
1086 if (!mtd->_lock)
1087 return -EOPNOTSUPP;
1088 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1089 return -EINVAL;
1090 if (!len)
1091 return 0;
1092 return mtd->_lock(mtd, ofs, len);
1093}
1094EXPORT_SYMBOL_GPL(mtd_lock);
1095
1096int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1097{
1098 if (!mtd->_unlock)
1099 return -EOPNOTSUPP;
1100 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1101 return -EINVAL;
1102 if (!len)
1103 return 0;
1104 return mtd->_unlock(mtd, ofs, len);
1105}
1106EXPORT_SYMBOL_GPL(mtd_unlock);
1107
1108int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1109{
1110 if (!mtd->_is_locked)
1111 return -EOPNOTSUPP;
1112 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1113 return -EINVAL;
1114 if (!len)
1115 return 0;
1116 return mtd->_is_locked(mtd, ofs, len);
1117}
1118EXPORT_SYMBOL_GPL(mtd_is_locked);
1119
1120int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1121{
1122 if (ofs < 0 || ofs >= mtd->size)
1123 return -EINVAL;
1124 if (!mtd->_block_isreserved)
1125 return 0;
1126 return mtd->_block_isreserved(mtd, ofs);
1127}
1128EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1129
1130int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1131{
1132 if (ofs < 0 || ofs >= mtd->size)
1133 return -EINVAL;
1134 if (!mtd->_block_isbad)
1135 return 0;
1136 return mtd->_block_isbad(mtd, ofs);
1137}
1138EXPORT_SYMBOL_GPL(mtd_block_isbad);
1139
1140int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1141{
1142 if (!mtd->_block_markbad)
1143 return -EOPNOTSUPP;
1144 if (ofs < 0 || ofs >= mtd->size)
1145 return -EINVAL;
1146 if (!(mtd->flags & MTD_WRITEABLE))
1147 return -EROFS;
1148 return mtd->_block_markbad(mtd, ofs);
1149}
1150EXPORT_SYMBOL_GPL(mtd_block_markbad);
1151
1152/*
1153 * default_mtd_writev - the default writev method
1154 * @mtd: mtd device description object pointer
1155 * @vecs: the vectors to write
1156 * @count: count of vectors in @vecs
1157 * @to: the MTD device offset to write to
1158 * @retlen: on exit contains the count of bytes written to the MTD device.
1159 *
1160 * This function returns zero in case of success and a negative error code in
1161 * case of failure.
1162 */
1163static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1164 unsigned long count, loff_t to, size_t *retlen)
1165{
1166 unsigned long i;
1167 size_t totlen = 0, thislen;
1168 int ret = 0;
1169
1170 for (i = 0; i < count; i++) {
1171 if (!vecs[i].iov_len)
1172 continue;
1173 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1174 vecs[i].iov_base);
1175 totlen += thislen;
1176 if (ret || thislen != vecs[i].iov_len)
1177 break;
1178 to += vecs[i].iov_len;
1179 }
1180 *retlen = totlen;
1181 return ret;
1182}
1183
1184/*
1185 * mtd_writev - the vector-based MTD write method
1186 * @mtd: mtd device description object pointer
1187 * @vecs: the vectors to write
1188 * @count: count of vectors in @vecs
1189 * @to: the MTD device offset to write to
1190 * @retlen: on exit contains the count of bytes written to the MTD device.
1191 *
1192 * This function returns zero in case of success and a negative error code in
1193 * case of failure.
1194 */
1195int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1196 unsigned long count, loff_t to, size_t *retlen)
1197{
1198 *retlen = 0;
1199 if (!(mtd->flags & MTD_WRITEABLE))
1200 return -EROFS;
1201 if (!mtd->_writev)
1202 return default_mtd_writev(mtd, vecs, count, to, retlen);
1203 return mtd->_writev(mtd, vecs, count, to, retlen);
1204}
1205EXPORT_SYMBOL_GPL(mtd_writev);
1206
1207/**
1208 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1209 * @mtd: mtd device description object pointer
1210 * @size: a pointer to the ideal or maximum size of the allocation, points
1211 * to the actual allocation size on success.
1212 *
1213 * This routine attempts to allocate a contiguous kernel buffer up to
1214 * the specified size, backing off the size of the request exponentially
1215 * until the request succeeds or until the allocation size falls below
1216 * the system page size. This attempts to make sure it does not adversely
1217 * impact system performance, so when allocating more than one page, we
1218 * ask the memory allocator to avoid re-trying, swapping, writing back
1219 * or performing I/O.
1220 *
1221 * Note, this function also makes sure that the allocated buffer is aligned to
1222 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1223 *
1224 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1225 * to handle smaller (i.e. degraded) buffer allocations under low- or
1226 * fragmented-memory situations where such reduced allocations, from a
1227 * requested ideal, are allowed.
1228 *
1229 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1230 */
1231void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1232{
1233 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1234 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1235 void *kbuf;
1236
1237 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1238
1239 while (*size > min_alloc) {
1240 kbuf = kmalloc(*size, flags);
1241 if (kbuf)
1242 return kbuf;
1243
1244 *size >>= 1;
1245 *size = ALIGN(*size, mtd->writesize);
1246 }
1247
1248 /*
1249 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1250 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1251 */
1252 return kmalloc(*size, GFP_KERNEL);
1253}
1254EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1255
1256#ifdef CONFIG_PROC_FS
1257
1258/*====================================================================*/
1259/* Support for /proc/mtd */
1260
1261static int mtd_proc_show(struct seq_file *m, void *v)
1262{
1263 struct mtd_info *mtd;
1264
1265 seq_puts(m, "dev: size erasesize name\n");
1266 mutex_lock(&mtd_table_mutex);
1267 mtd_for_each_device(mtd) {
1268 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1269 mtd->index, (unsigned long long)mtd->size,
1270 mtd->erasesize, mtd->name);
1271 }
1272 mutex_unlock(&mtd_table_mutex);
1273 return 0;
1274}
1275
1276static int mtd_proc_open(struct inode *inode, struct file *file)
1277{
1278 return single_open(file, mtd_proc_show, NULL);
1279}
1280
1281static const struct file_operations mtd_proc_ops = {
1282 .open = mtd_proc_open,
1283 .read = seq_read,
1284 .llseek = seq_lseek,
1285 .release = single_release,
1286};
1287#endif /* CONFIG_PROC_FS */
1288
1289/*====================================================================*/
1290/* Init code */
1291
1292static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1293{
1294 int ret;
1295
1296 ret = bdi_init(bdi);
1297 if (!ret)
1298 ret = bdi_register(bdi, NULL, "%s", name);
1299
1300 if (ret)
1301 bdi_destroy(bdi);
1302
1303 return ret;
1304}
1305
1306static struct proc_dir_entry *proc_mtd;
1307
1308static int __init init_mtd(void)
1309{
1310 int ret;
1311
1312 ret = class_register(&mtd_class);
1313 if (ret)
1314 goto err_reg;
1315
1316 ret = mtd_bdi_init(&mtd_bdi, "mtd");
1317 if (ret)
1318 goto err_bdi;
1319
1320 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1321
1322 ret = init_mtdchar();
1323 if (ret)
1324 goto out_procfs;
1325
1326 return 0;
1327
1328out_procfs:
1329 if (proc_mtd)
1330 remove_proc_entry("mtd", NULL);
1331err_bdi:
1332 class_unregister(&mtd_class);
1333err_reg:
1334 pr_err("Error registering mtd class or bdi: %d\n", ret);
1335 return ret;
1336}
1337
1338static void __exit cleanup_mtd(void)
1339{
1340 cleanup_mtdchar();
1341 if (proc_mtd)
1342 remove_proc_entry("mtd", NULL);
1343 class_unregister(&mtd_class);
1344 bdi_destroy(&mtd_bdi);
1345 idr_destroy(&mtd_idr);
1346}
1347
1348module_init(init_mtd);
1349module_exit(cleanup_mtd);
1350
1351MODULE_LICENSE("GPL");
1352MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1353MODULE_DESCRIPTION("Core MTD registration and access routines");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Core registration and callback routines for MTD
4 * drivers and users.
5 *
6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
7 * Copyright © 2006 Red Hat UK Limited
8 */
9
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/ptrace.h>
13#include <linux/seq_file.h>
14#include <linux/string.h>
15#include <linux/timer.h>
16#include <linux/major.h>
17#include <linux/fs.h>
18#include <linux/err.h>
19#include <linux/ioctl.h>
20#include <linux/init.h>
21#include <linux/of.h>
22#include <linux/proc_fs.h>
23#include <linux/idr.h>
24#include <linux/backing-dev.h>
25#include <linux/gfp.h>
26#include <linux/slab.h>
27#include <linux/reboot.h>
28#include <linux/leds.h>
29#include <linux/debugfs.h>
30#include <linux/nvmem-provider.h>
31
32#include <linux/mtd/mtd.h>
33#include <linux/mtd/partitions.h>
34
35#include "mtdcore.h"
36
37struct backing_dev_info *mtd_bdi;
38
39#ifdef CONFIG_PM_SLEEP
40
41static int mtd_cls_suspend(struct device *dev)
42{
43 struct mtd_info *mtd = dev_get_drvdata(dev);
44
45 return mtd ? mtd_suspend(mtd) : 0;
46}
47
48static int mtd_cls_resume(struct device *dev)
49{
50 struct mtd_info *mtd = dev_get_drvdata(dev);
51
52 if (mtd)
53 mtd_resume(mtd);
54 return 0;
55}
56
57static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
58#define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
59#else
60#define MTD_CLS_PM_OPS NULL
61#endif
62
63static struct class mtd_class = {
64 .name = "mtd",
65 .owner = THIS_MODULE,
66 .pm = MTD_CLS_PM_OPS,
67};
68
69static DEFINE_IDR(mtd_idr);
70
71/* These are exported solely for the purpose of mtd_blkdevs.c. You
72 should not use them for _anything_ else */
73DEFINE_MUTEX(mtd_table_mutex);
74EXPORT_SYMBOL_GPL(mtd_table_mutex);
75
76struct mtd_info *__mtd_next_device(int i)
77{
78 return idr_get_next(&mtd_idr, &i);
79}
80EXPORT_SYMBOL_GPL(__mtd_next_device);
81
82static LIST_HEAD(mtd_notifiers);
83
84
85#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
86
87/* REVISIT once MTD uses the driver model better, whoever allocates
88 * the mtd_info will probably want to use the release() hook...
89 */
90static void mtd_release(struct device *dev)
91{
92 struct mtd_info *mtd = dev_get_drvdata(dev);
93 dev_t index = MTD_DEVT(mtd->index);
94
95 /* remove /dev/mtdXro node */
96 device_destroy(&mtd_class, index + 1);
97}
98
99static ssize_t mtd_type_show(struct device *dev,
100 struct device_attribute *attr, char *buf)
101{
102 struct mtd_info *mtd = dev_get_drvdata(dev);
103 char *type;
104
105 switch (mtd->type) {
106 case MTD_ABSENT:
107 type = "absent";
108 break;
109 case MTD_RAM:
110 type = "ram";
111 break;
112 case MTD_ROM:
113 type = "rom";
114 break;
115 case MTD_NORFLASH:
116 type = "nor";
117 break;
118 case MTD_NANDFLASH:
119 type = "nand";
120 break;
121 case MTD_DATAFLASH:
122 type = "dataflash";
123 break;
124 case MTD_UBIVOLUME:
125 type = "ubi";
126 break;
127 case MTD_MLCNANDFLASH:
128 type = "mlc-nand";
129 break;
130 default:
131 type = "unknown";
132 }
133
134 return snprintf(buf, PAGE_SIZE, "%s\n", type);
135}
136static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
137
138static ssize_t mtd_flags_show(struct device *dev,
139 struct device_attribute *attr, char *buf)
140{
141 struct mtd_info *mtd = dev_get_drvdata(dev);
142
143 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
144}
145static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
146
147static ssize_t mtd_size_show(struct device *dev,
148 struct device_attribute *attr, char *buf)
149{
150 struct mtd_info *mtd = dev_get_drvdata(dev);
151
152 return snprintf(buf, PAGE_SIZE, "%llu\n",
153 (unsigned long long)mtd->size);
154}
155static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
156
157static ssize_t mtd_erasesize_show(struct device *dev,
158 struct device_attribute *attr, char *buf)
159{
160 struct mtd_info *mtd = dev_get_drvdata(dev);
161
162 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
163}
164static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
165
166static ssize_t mtd_writesize_show(struct device *dev,
167 struct device_attribute *attr, char *buf)
168{
169 struct mtd_info *mtd = dev_get_drvdata(dev);
170
171 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
172}
173static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
174
175static ssize_t mtd_subpagesize_show(struct device *dev,
176 struct device_attribute *attr, char *buf)
177{
178 struct mtd_info *mtd = dev_get_drvdata(dev);
179 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
180
181 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
182}
183static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
184
185static ssize_t mtd_oobsize_show(struct device *dev,
186 struct device_attribute *attr, char *buf)
187{
188 struct mtd_info *mtd = dev_get_drvdata(dev);
189
190 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
191}
192static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
193
194static ssize_t mtd_oobavail_show(struct device *dev,
195 struct device_attribute *attr, char *buf)
196{
197 struct mtd_info *mtd = dev_get_drvdata(dev);
198
199 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->oobavail);
200}
201static DEVICE_ATTR(oobavail, S_IRUGO, mtd_oobavail_show, NULL);
202
203static ssize_t mtd_numeraseregions_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
205{
206 struct mtd_info *mtd = dev_get_drvdata(dev);
207
208 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
209}
210static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
211 NULL);
212
213static ssize_t mtd_name_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
215{
216 struct mtd_info *mtd = dev_get_drvdata(dev);
217
218 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
219}
220static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
221
222static ssize_t mtd_ecc_strength_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, "%u\n", mtd->ecc_strength);
228}
229static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
230
231static ssize_t mtd_bitflip_threshold_show(struct device *dev,
232 struct device_attribute *attr,
233 char *buf)
234{
235 struct mtd_info *mtd = dev_get_drvdata(dev);
236
237 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
238}
239
240static ssize_t mtd_bitflip_threshold_store(struct device *dev,
241 struct device_attribute *attr,
242 const char *buf, size_t count)
243{
244 struct mtd_info *mtd = dev_get_drvdata(dev);
245 unsigned int bitflip_threshold;
246 int retval;
247
248 retval = kstrtouint(buf, 0, &bitflip_threshold);
249 if (retval)
250 return retval;
251
252 mtd->bitflip_threshold = bitflip_threshold;
253 return count;
254}
255static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
256 mtd_bitflip_threshold_show,
257 mtd_bitflip_threshold_store);
258
259static ssize_t mtd_ecc_step_size_show(struct device *dev,
260 struct device_attribute *attr, char *buf)
261{
262 struct mtd_info *mtd = dev_get_drvdata(dev);
263
264 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
265
266}
267static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
268
269static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
270 struct device_attribute *attr, char *buf)
271{
272 struct mtd_info *mtd = dev_get_drvdata(dev);
273 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
274
275 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
276}
277static DEVICE_ATTR(corrected_bits, S_IRUGO,
278 mtd_ecc_stats_corrected_show, NULL);
279
280static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
281 struct device_attribute *attr, char *buf)
282{
283 struct mtd_info *mtd = dev_get_drvdata(dev);
284 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
285
286 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
287}
288static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
289
290static ssize_t mtd_badblocks_show(struct device *dev,
291 struct device_attribute *attr, char *buf)
292{
293 struct mtd_info *mtd = dev_get_drvdata(dev);
294 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
295
296 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
297}
298static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
299
300static ssize_t mtd_bbtblocks_show(struct device *dev,
301 struct device_attribute *attr, char *buf)
302{
303 struct mtd_info *mtd = dev_get_drvdata(dev);
304 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
305
306 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
307}
308static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
309
310static struct attribute *mtd_attrs[] = {
311 &dev_attr_type.attr,
312 &dev_attr_flags.attr,
313 &dev_attr_size.attr,
314 &dev_attr_erasesize.attr,
315 &dev_attr_writesize.attr,
316 &dev_attr_subpagesize.attr,
317 &dev_attr_oobsize.attr,
318 &dev_attr_oobavail.attr,
319 &dev_attr_numeraseregions.attr,
320 &dev_attr_name.attr,
321 &dev_attr_ecc_strength.attr,
322 &dev_attr_ecc_step_size.attr,
323 &dev_attr_corrected_bits.attr,
324 &dev_attr_ecc_failures.attr,
325 &dev_attr_bad_blocks.attr,
326 &dev_attr_bbt_blocks.attr,
327 &dev_attr_bitflip_threshold.attr,
328 NULL,
329};
330ATTRIBUTE_GROUPS(mtd);
331
332static const struct device_type mtd_devtype = {
333 .name = "mtd",
334 .groups = mtd_groups,
335 .release = mtd_release,
336};
337
338static int mtd_partid_show(struct seq_file *s, void *p)
339{
340 struct mtd_info *mtd = s->private;
341
342 seq_printf(s, "%s\n", mtd->dbg.partid);
343
344 return 0;
345}
346
347static int mtd_partid_debugfs_open(struct inode *inode, struct file *file)
348{
349 return single_open(file, mtd_partid_show, inode->i_private);
350}
351
352static const struct file_operations mtd_partid_debug_fops = {
353 .open = mtd_partid_debugfs_open,
354 .read = seq_read,
355 .llseek = seq_lseek,
356 .release = single_release,
357};
358
359static int mtd_partname_show(struct seq_file *s, void *p)
360{
361 struct mtd_info *mtd = s->private;
362
363 seq_printf(s, "%s\n", mtd->dbg.partname);
364
365 return 0;
366}
367
368static int mtd_partname_debugfs_open(struct inode *inode, struct file *file)
369{
370 return single_open(file, mtd_partname_show, inode->i_private);
371}
372
373static const struct file_operations mtd_partname_debug_fops = {
374 .open = mtd_partname_debugfs_open,
375 .read = seq_read,
376 .llseek = seq_lseek,
377 .release = single_release,
378};
379
380static struct dentry *dfs_dir_mtd;
381
382static void mtd_debugfs_populate(struct mtd_info *mtd)
383{
384 struct device *dev = &mtd->dev;
385 struct dentry *root, *dent;
386
387 if (IS_ERR_OR_NULL(dfs_dir_mtd))
388 return;
389
390 root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
391 if (IS_ERR_OR_NULL(root)) {
392 dev_dbg(dev, "won't show data in debugfs\n");
393 return;
394 }
395
396 mtd->dbg.dfs_dir = root;
397
398 if (mtd->dbg.partid) {
399 dent = debugfs_create_file("partid", 0400, root, mtd,
400 &mtd_partid_debug_fops);
401 if (IS_ERR_OR_NULL(dent))
402 dev_err(dev, "can't create debugfs entry for partid\n");
403 }
404
405 if (mtd->dbg.partname) {
406 dent = debugfs_create_file("partname", 0400, root, mtd,
407 &mtd_partname_debug_fops);
408 if (IS_ERR_OR_NULL(dent))
409 dev_err(dev,
410 "can't create debugfs entry for partname\n");
411 }
412}
413
414#ifndef CONFIG_MMU
415unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
416{
417 switch (mtd->type) {
418 case MTD_RAM:
419 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
420 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
421 case MTD_ROM:
422 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
423 NOMMU_MAP_READ;
424 default:
425 return NOMMU_MAP_COPY;
426 }
427}
428EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
429#endif
430
431static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
432 void *cmd)
433{
434 struct mtd_info *mtd;
435
436 mtd = container_of(n, struct mtd_info, reboot_notifier);
437 mtd->_reboot(mtd);
438
439 return NOTIFY_DONE;
440}
441
442/**
443 * mtd_wunit_to_pairing_info - get pairing information of a wunit
444 * @mtd: pointer to new MTD device info structure
445 * @wunit: write unit we are interested in
446 * @info: returned pairing information
447 *
448 * Retrieve pairing information associated to the wunit.
449 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
450 * paired together, and where programming a page may influence the page it is
451 * paired with.
452 * The notion of page is replaced by the term wunit (write-unit) to stay
453 * consistent with the ->writesize field.
454 *
455 * The @wunit argument can be extracted from an absolute offset using
456 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
457 * to @wunit.
458 *
459 * From the pairing info the MTD user can find all the wunits paired with
460 * @wunit using the following loop:
461 *
462 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
463 * info.pair = i;
464 * mtd_pairing_info_to_wunit(mtd, &info);
465 * ...
466 * }
467 */
468int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
469 struct mtd_pairing_info *info)
470{
471 int npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
472
473 if (wunit < 0 || wunit >= npairs)
474 return -EINVAL;
475
476 if (mtd->pairing && mtd->pairing->get_info)
477 return mtd->pairing->get_info(mtd, wunit, info);
478
479 info->group = 0;
480 info->pair = wunit;
481
482 return 0;
483}
484EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
485
486/**
487 * mtd_pairing_info_to_wunit - get wunit from pairing information
488 * @mtd: pointer to new MTD device info structure
489 * @info: pairing information struct
490 *
491 * Returns a positive number representing the wunit associated to the info
492 * struct, or a negative error code.
493 *
494 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
495 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
496 * doc).
497 *
498 * It can also be used to only program the first page of each pair (i.e.
499 * page attached to group 0), which allows one to use an MLC NAND in
500 * software-emulated SLC mode:
501 *
502 * info.group = 0;
503 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
504 * for (info.pair = 0; info.pair < npairs; info.pair++) {
505 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
506 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
507 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
508 * }
509 */
510int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
511 const struct mtd_pairing_info *info)
512{
513 int ngroups = mtd_pairing_groups(mtd);
514 int npairs = mtd_wunit_per_eb(mtd) / ngroups;
515
516 if (!info || info->pair < 0 || info->pair >= npairs ||
517 info->group < 0 || info->group >= ngroups)
518 return -EINVAL;
519
520 if (mtd->pairing && mtd->pairing->get_wunit)
521 return mtd->pairing->get_wunit(mtd, info);
522
523 return info->pair;
524}
525EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
526
527/**
528 * mtd_pairing_groups - get the number of pairing groups
529 * @mtd: pointer to new MTD device info structure
530 *
531 * Returns the number of pairing groups.
532 *
533 * This number is usually equal to the number of bits exposed by a single
534 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
535 * to iterate over all pages of a given pair.
536 */
537int mtd_pairing_groups(struct mtd_info *mtd)
538{
539 if (!mtd->pairing || !mtd->pairing->ngroups)
540 return 1;
541
542 return mtd->pairing->ngroups;
543}
544EXPORT_SYMBOL_GPL(mtd_pairing_groups);
545
546static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
547 void *val, size_t bytes)
548{
549 struct mtd_info *mtd = priv;
550 size_t retlen;
551 int err;
552
553 err = mtd_read(mtd, offset, bytes, &retlen, val);
554 if (err && err != -EUCLEAN)
555 return err;
556
557 return retlen == bytes ? 0 : -EIO;
558}
559
560static int mtd_nvmem_add(struct mtd_info *mtd)
561{
562 struct nvmem_config config = {};
563
564 config.id = -1;
565 config.dev = &mtd->dev;
566 config.name = mtd->name;
567 config.owner = THIS_MODULE;
568 config.reg_read = mtd_nvmem_reg_read;
569 config.size = mtd->size;
570 config.word_size = 1;
571 config.stride = 1;
572 config.read_only = true;
573 config.root_only = true;
574 config.no_of_node = true;
575 config.priv = mtd;
576
577 mtd->nvmem = nvmem_register(&config);
578 if (IS_ERR(mtd->nvmem)) {
579 /* Just ignore if there is no NVMEM support in the kernel */
580 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
581 mtd->nvmem = NULL;
582 } else {
583 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
584 return PTR_ERR(mtd->nvmem);
585 }
586 }
587
588 return 0;
589}
590
591/**
592 * add_mtd_device - register an MTD device
593 * @mtd: pointer to new MTD device info structure
594 *
595 * Add a device to the list of MTD devices present in the system, and
596 * notify each currently active MTD 'user' of its arrival. Returns
597 * zero on success or non-zero on failure.
598 */
599
600int add_mtd_device(struct mtd_info *mtd)
601{
602 struct mtd_notifier *not;
603 int i, error;
604
605 /*
606 * May occur, for instance, on buggy drivers which call
607 * mtd_device_parse_register() multiple times on the same master MTD,
608 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
609 */
610 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
611 return -EEXIST;
612
613 BUG_ON(mtd->writesize == 0);
614
615 /*
616 * MTD drivers should implement ->_{write,read}() or
617 * ->_{write,read}_oob(), but not both.
618 */
619 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
620 (mtd->_read && mtd->_read_oob)))
621 return -EINVAL;
622
623 if (WARN_ON((!mtd->erasesize || !mtd->_erase) &&
624 !(mtd->flags & MTD_NO_ERASE)))
625 return -EINVAL;
626
627 mutex_lock(&mtd_table_mutex);
628
629 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
630 if (i < 0) {
631 error = i;
632 goto fail_locked;
633 }
634
635 mtd->index = i;
636 mtd->usecount = 0;
637
638 /* default value if not set by driver */
639 if (mtd->bitflip_threshold == 0)
640 mtd->bitflip_threshold = mtd->ecc_strength;
641
642 if (is_power_of_2(mtd->erasesize))
643 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
644 else
645 mtd->erasesize_shift = 0;
646
647 if (is_power_of_2(mtd->writesize))
648 mtd->writesize_shift = ffs(mtd->writesize) - 1;
649 else
650 mtd->writesize_shift = 0;
651
652 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
653 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
654
655 /* Some chips always power up locked. Unlock them now */
656 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
657 error = mtd_unlock(mtd, 0, mtd->size);
658 if (error && error != -EOPNOTSUPP)
659 printk(KERN_WARNING
660 "%s: unlock failed, writes may not work\n",
661 mtd->name);
662 /* Ignore unlock failures? */
663 error = 0;
664 }
665
666 /* Caller should have set dev.parent to match the
667 * physical device, if appropriate.
668 */
669 mtd->dev.type = &mtd_devtype;
670 mtd->dev.class = &mtd_class;
671 mtd->dev.devt = MTD_DEVT(i);
672 dev_set_name(&mtd->dev, "mtd%d", i);
673 dev_set_drvdata(&mtd->dev, mtd);
674 of_node_get(mtd_get_of_node(mtd));
675 error = device_register(&mtd->dev);
676 if (error)
677 goto fail_added;
678
679 /* Add the nvmem provider */
680 error = mtd_nvmem_add(mtd);
681 if (error)
682 goto fail_nvmem_add;
683
684 mtd_debugfs_populate(mtd);
685
686 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
687 "mtd%dro", i);
688
689 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
690 /* No need to get a refcount on the module containing
691 the notifier, since we hold the mtd_table_mutex */
692 list_for_each_entry(not, &mtd_notifiers, list)
693 not->add(mtd);
694
695 mutex_unlock(&mtd_table_mutex);
696 /* We _know_ we aren't being removed, because
697 our caller is still holding us here. So none
698 of this try_ nonsense, and no bitching about it
699 either. :) */
700 __module_get(THIS_MODULE);
701 return 0;
702
703fail_nvmem_add:
704 device_unregister(&mtd->dev);
705fail_added:
706 of_node_put(mtd_get_of_node(mtd));
707 idr_remove(&mtd_idr, i);
708fail_locked:
709 mutex_unlock(&mtd_table_mutex);
710 return error;
711}
712
713/**
714 * del_mtd_device - unregister an MTD device
715 * @mtd: pointer to MTD device info structure
716 *
717 * Remove a device from the list of MTD devices present in the system,
718 * and notify each currently active MTD 'user' of its departure.
719 * Returns zero on success or 1 on failure, which currently will happen
720 * if the requested device does not appear to be present in the list.
721 */
722
723int del_mtd_device(struct mtd_info *mtd)
724{
725 int ret;
726 struct mtd_notifier *not;
727
728 mutex_lock(&mtd_table_mutex);
729
730 debugfs_remove_recursive(mtd->dbg.dfs_dir);
731
732 if (idr_find(&mtd_idr, mtd->index) != mtd) {
733 ret = -ENODEV;
734 goto out_error;
735 }
736
737 /* No need to get a refcount on the module containing
738 the notifier, since we hold the mtd_table_mutex */
739 list_for_each_entry(not, &mtd_notifiers, list)
740 not->remove(mtd);
741
742 if (mtd->usecount) {
743 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
744 mtd->index, mtd->name, mtd->usecount);
745 ret = -EBUSY;
746 } else {
747 /* Try to remove the NVMEM provider */
748 if (mtd->nvmem)
749 nvmem_unregister(mtd->nvmem);
750
751 device_unregister(&mtd->dev);
752
753 idr_remove(&mtd_idr, mtd->index);
754 of_node_put(mtd_get_of_node(mtd));
755
756 module_put(THIS_MODULE);
757 ret = 0;
758 }
759
760out_error:
761 mutex_unlock(&mtd_table_mutex);
762 return ret;
763}
764
765/*
766 * Set a few defaults based on the parent devices, if not provided by the
767 * driver
768 */
769static void mtd_set_dev_defaults(struct mtd_info *mtd)
770{
771 if (mtd->dev.parent) {
772 if (!mtd->owner && mtd->dev.parent->driver)
773 mtd->owner = mtd->dev.parent->driver->owner;
774 if (!mtd->name)
775 mtd->name = dev_name(mtd->dev.parent);
776 } else {
777 pr_debug("mtd device won't show a device symlink in sysfs\n");
778 }
779
780 mtd->orig_flags = mtd->flags;
781}
782
783/**
784 * mtd_device_parse_register - parse partitions and register an MTD device.
785 *
786 * @mtd: the MTD device to register
787 * @types: the list of MTD partition probes to try, see
788 * 'parse_mtd_partitions()' for more information
789 * @parser_data: MTD partition parser-specific data
790 * @parts: fallback partition information to register, if parsing fails;
791 * only valid if %nr_parts > %0
792 * @nr_parts: the number of partitions in parts, if zero then the full
793 * MTD device is registered if no partition info is found
794 *
795 * This function aggregates MTD partitions parsing (done by
796 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
797 * basically follows the most common pattern found in many MTD drivers:
798 *
799 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
800 * registered first.
801 * * Then It tries to probe partitions on MTD device @mtd using parsers
802 * specified in @types (if @types is %NULL, then the default list of parsers
803 * is used, see 'parse_mtd_partitions()' for more information). If none are
804 * found this functions tries to fallback to information specified in
805 * @parts/@nr_parts.
806 * * If no partitions were found this function just registers the MTD device
807 * @mtd and exits.
808 *
809 * Returns zero in case of success and a negative error code in case of failure.
810 */
811int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
812 struct mtd_part_parser_data *parser_data,
813 const struct mtd_partition *parts,
814 int nr_parts)
815{
816 int ret;
817
818 mtd_set_dev_defaults(mtd);
819
820 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
821 ret = add_mtd_device(mtd);
822 if (ret)
823 return ret;
824 }
825
826 /* Prefer parsed partitions over driver-provided fallback */
827 ret = parse_mtd_partitions(mtd, types, parser_data);
828 if (ret > 0)
829 ret = 0;
830 else if (nr_parts)
831 ret = add_mtd_partitions(mtd, parts, nr_parts);
832 else if (!device_is_registered(&mtd->dev))
833 ret = add_mtd_device(mtd);
834 else
835 ret = 0;
836
837 if (ret)
838 goto out;
839
840 /*
841 * FIXME: some drivers unfortunately call this function more than once.
842 * So we have to check if we've already assigned the reboot notifier.
843 *
844 * Generally, we can make multiple calls work for most cases, but it
845 * does cause problems with parse_mtd_partitions() above (e.g.,
846 * cmdlineparts will register partitions more than once).
847 */
848 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
849 "MTD already registered\n");
850 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
851 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
852 register_reboot_notifier(&mtd->reboot_notifier);
853 }
854
855out:
856 if (ret && device_is_registered(&mtd->dev))
857 del_mtd_device(mtd);
858
859 return ret;
860}
861EXPORT_SYMBOL_GPL(mtd_device_parse_register);
862
863/**
864 * mtd_device_unregister - unregister an existing MTD device.
865 *
866 * @master: the MTD device to unregister. This will unregister both the master
867 * and any partitions if registered.
868 */
869int mtd_device_unregister(struct mtd_info *master)
870{
871 int err;
872
873 if (master->_reboot)
874 unregister_reboot_notifier(&master->reboot_notifier);
875
876 err = del_mtd_partitions(master);
877 if (err)
878 return err;
879
880 if (!device_is_registered(&master->dev))
881 return 0;
882
883 return del_mtd_device(master);
884}
885EXPORT_SYMBOL_GPL(mtd_device_unregister);
886
887/**
888 * register_mtd_user - register a 'user' of MTD devices.
889 * @new: pointer to notifier info structure
890 *
891 * Registers a pair of callbacks function to be called upon addition
892 * or removal of MTD devices. Causes the 'add' callback to be immediately
893 * invoked for each MTD device currently present in the system.
894 */
895void register_mtd_user (struct mtd_notifier *new)
896{
897 struct mtd_info *mtd;
898
899 mutex_lock(&mtd_table_mutex);
900
901 list_add(&new->list, &mtd_notifiers);
902
903 __module_get(THIS_MODULE);
904
905 mtd_for_each_device(mtd)
906 new->add(mtd);
907
908 mutex_unlock(&mtd_table_mutex);
909}
910EXPORT_SYMBOL_GPL(register_mtd_user);
911
912/**
913 * unregister_mtd_user - unregister a 'user' of MTD devices.
914 * @old: pointer to notifier info structure
915 *
916 * Removes a callback function pair from the list of 'users' to be
917 * notified upon addition or removal of MTD devices. Causes the
918 * 'remove' callback to be immediately invoked for each MTD device
919 * currently present in the system.
920 */
921int unregister_mtd_user (struct mtd_notifier *old)
922{
923 struct mtd_info *mtd;
924
925 mutex_lock(&mtd_table_mutex);
926
927 module_put(THIS_MODULE);
928
929 mtd_for_each_device(mtd)
930 old->remove(mtd);
931
932 list_del(&old->list);
933 mutex_unlock(&mtd_table_mutex);
934 return 0;
935}
936EXPORT_SYMBOL_GPL(unregister_mtd_user);
937
938/**
939 * get_mtd_device - obtain a validated handle for an MTD device
940 * @mtd: last known address of the required MTD device
941 * @num: internal device number of the required MTD device
942 *
943 * Given a number and NULL address, return the num'th entry in the device
944 * table, if any. Given an address and num == -1, search the device table
945 * for a device with that address and return if it's still present. Given
946 * both, return the num'th driver only if its address matches. Return
947 * error code if not.
948 */
949struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
950{
951 struct mtd_info *ret = NULL, *other;
952 int err = -ENODEV;
953
954 mutex_lock(&mtd_table_mutex);
955
956 if (num == -1) {
957 mtd_for_each_device(other) {
958 if (other == mtd) {
959 ret = mtd;
960 break;
961 }
962 }
963 } else if (num >= 0) {
964 ret = idr_find(&mtd_idr, num);
965 if (mtd && mtd != ret)
966 ret = NULL;
967 }
968
969 if (!ret) {
970 ret = ERR_PTR(err);
971 goto out;
972 }
973
974 err = __get_mtd_device(ret);
975 if (err)
976 ret = ERR_PTR(err);
977out:
978 mutex_unlock(&mtd_table_mutex);
979 return ret;
980}
981EXPORT_SYMBOL_GPL(get_mtd_device);
982
983
984int __get_mtd_device(struct mtd_info *mtd)
985{
986 int err;
987
988 if (!try_module_get(mtd->owner))
989 return -ENODEV;
990
991 if (mtd->_get_device) {
992 err = mtd->_get_device(mtd);
993
994 if (err) {
995 module_put(mtd->owner);
996 return err;
997 }
998 }
999 mtd->usecount++;
1000 return 0;
1001}
1002EXPORT_SYMBOL_GPL(__get_mtd_device);
1003
1004/**
1005 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1006 * device name
1007 * @name: MTD device name to open
1008 *
1009 * This function returns MTD device description structure in case of
1010 * success and an error code in case of failure.
1011 */
1012struct mtd_info *get_mtd_device_nm(const char *name)
1013{
1014 int err = -ENODEV;
1015 struct mtd_info *mtd = NULL, *other;
1016
1017 mutex_lock(&mtd_table_mutex);
1018
1019 mtd_for_each_device(other) {
1020 if (!strcmp(name, other->name)) {
1021 mtd = other;
1022 break;
1023 }
1024 }
1025
1026 if (!mtd)
1027 goto out_unlock;
1028
1029 err = __get_mtd_device(mtd);
1030 if (err)
1031 goto out_unlock;
1032
1033 mutex_unlock(&mtd_table_mutex);
1034 return mtd;
1035
1036out_unlock:
1037 mutex_unlock(&mtd_table_mutex);
1038 return ERR_PTR(err);
1039}
1040EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1041
1042void put_mtd_device(struct mtd_info *mtd)
1043{
1044 mutex_lock(&mtd_table_mutex);
1045 __put_mtd_device(mtd);
1046 mutex_unlock(&mtd_table_mutex);
1047
1048}
1049EXPORT_SYMBOL_GPL(put_mtd_device);
1050
1051void __put_mtd_device(struct mtd_info *mtd)
1052{
1053 --mtd->usecount;
1054 BUG_ON(mtd->usecount < 0);
1055
1056 if (mtd->_put_device)
1057 mtd->_put_device(mtd);
1058
1059 module_put(mtd->owner);
1060}
1061EXPORT_SYMBOL_GPL(__put_mtd_device);
1062
1063/*
1064 * Erase is an synchronous operation. Device drivers are epected to return a
1065 * negative error code if the operation failed and update instr->fail_addr
1066 * to point the portion that was not properly erased.
1067 */
1068int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1069{
1070 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1071
1072 if (!mtd->erasesize || !mtd->_erase)
1073 return -ENOTSUPP;
1074
1075 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1076 return -EINVAL;
1077 if (!(mtd->flags & MTD_WRITEABLE))
1078 return -EROFS;
1079
1080 if (!instr->len)
1081 return 0;
1082
1083 ledtrig_mtd_activity();
1084 return mtd->_erase(mtd, instr);
1085}
1086EXPORT_SYMBOL_GPL(mtd_erase);
1087
1088/*
1089 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1090 */
1091int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1092 void **virt, resource_size_t *phys)
1093{
1094 *retlen = 0;
1095 *virt = NULL;
1096 if (phys)
1097 *phys = 0;
1098 if (!mtd->_point)
1099 return -EOPNOTSUPP;
1100 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1101 return -EINVAL;
1102 if (!len)
1103 return 0;
1104 return mtd->_point(mtd, from, len, retlen, virt, phys);
1105}
1106EXPORT_SYMBOL_GPL(mtd_point);
1107
1108/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1109int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1110{
1111 if (!mtd->_unpoint)
1112 return -EOPNOTSUPP;
1113 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1114 return -EINVAL;
1115 if (!len)
1116 return 0;
1117 return mtd->_unpoint(mtd, from, len);
1118}
1119EXPORT_SYMBOL_GPL(mtd_unpoint);
1120
1121/*
1122 * Allow NOMMU mmap() to directly map the device (if not NULL)
1123 * - return the address to which the offset maps
1124 * - return -ENOSYS to indicate refusal to do the mapping
1125 */
1126unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1127 unsigned long offset, unsigned long flags)
1128{
1129 size_t retlen;
1130 void *virt;
1131 int ret;
1132
1133 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1134 if (ret)
1135 return ret;
1136 if (retlen != len) {
1137 mtd_unpoint(mtd, offset, retlen);
1138 return -ENOSYS;
1139 }
1140 return (unsigned long)virt;
1141}
1142EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1143
1144int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1145 u_char *buf)
1146{
1147 struct mtd_oob_ops ops = {
1148 .len = len,
1149 .datbuf = buf,
1150 };
1151 int ret;
1152
1153 ret = mtd_read_oob(mtd, from, &ops);
1154 *retlen = ops.retlen;
1155
1156 return ret;
1157}
1158EXPORT_SYMBOL_GPL(mtd_read);
1159
1160int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1161 const u_char *buf)
1162{
1163 struct mtd_oob_ops ops = {
1164 .len = len,
1165 .datbuf = (u8 *)buf,
1166 };
1167 int ret;
1168
1169 ret = mtd_write_oob(mtd, to, &ops);
1170 *retlen = ops.retlen;
1171
1172 return ret;
1173}
1174EXPORT_SYMBOL_GPL(mtd_write);
1175
1176/*
1177 * In blackbox flight recorder like scenarios we want to make successful writes
1178 * in interrupt context. panic_write() is only intended to be called when its
1179 * known the kernel is about to panic and we need the write to succeed. Since
1180 * the kernel is not going to be running for much longer, this function can
1181 * break locks and delay to ensure the write succeeds (but not sleep).
1182 */
1183int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1184 const u_char *buf)
1185{
1186 *retlen = 0;
1187 if (!mtd->_panic_write)
1188 return -EOPNOTSUPP;
1189 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1190 return -EINVAL;
1191 if (!(mtd->flags & MTD_WRITEABLE))
1192 return -EROFS;
1193 if (!len)
1194 return 0;
1195 if (!mtd->oops_panic_write)
1196 mtd->oops_panic_write = true;
1197
1198 return mtd->_panic_write(mtd, to, len, retlen, buf);
1199}
1200EXPORT_SYMBOL_GPL(mtd_panic_write);
1201
1202static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1203 struct mtd_oob_ops *ops)
1204{
1205 /*
1206 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1207 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1208 * this case.
1209 */
1210 if (!ops->datbuf)
1211 ops->len = 0;
1212
1213 if (!ops->oobbuf)
1214 ops->ooblen = 0;
1215
1216 if (offs < 0 || offs + ops->len > mtd->size)
1217 return -EINVAL;
1218
1219 if (ops->ooblen) {
1220 size_t maxooblen;
1221
1222 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1223 return -EINVAL;
1224
1225 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1226 mtd_div_by_ws(offs, mtd)) *
1227 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1228 if (ops->ooblen > maxooblen)
1229 return -EINVAL;
1230 }
1231
1232 return 0;
1233}
1234
1235int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1236{
1237 int ret_code;
1238 ops->retlen = ops->oobretlen = 0;
1239
1240 ret_code = mtd_check_oob_ops(mtd, from, ops);
1241 if (ret_code)
1242 return ret_code;
1243
1244 ledtrig_mtd_activity();
1245
1246 /* Check the validity of a potential fallback on mtd->_read */
1247 if (!mtd->_read_oob && (!mtd->_read || ops->oobbuf))
1248 return -EOPNOTSUPP;
1249
1250 if (mtd->_read_oob)
1251 ret_code = mtd->_read_oob(mtd, from, ops);
1252 else
1253 ret_code = mtd->_read(mtd, from, ops->len, &ops->retlen,
1254 ops->datbuf);
1255
1256 /*
1257 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1258 * similar to mtd->_read(), returning a non-negative integer
1259 * representing max bitflips. In other cases, mtd->_read_oob() may
1260 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1261 */
1262 if (unlikely(ret_code < 0))
1263 return ret_code;
1264 if (mtd->ecc_strength == 0)
1265 return 0; /* device lacks ecc */
1266 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1267}
1268EXPORT_SYMBOL_GPL(mtd_read_oob);
1269
1270int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1271 struct mtd_oob_ops *ops)
1272{
1273 int ret;
1274
1275 ops->retlen = ops->oobretlen = 0;
1276
1277 if (!(mtd->flags & MTD_WRITEABLE))
1278 return -EROFS;
1279
1280 ret = mtd_check_oob_ops(mtd, to, ops);
1281 if (ret)
1282 return ret;
1283
1284 ledtrig_mtd_activity();
1285
1286 /* Check the validity of a potential fallback on mtd->_write */
1287 if (!mtd->_write_oob && (!mtd->_write || ops->oobbuf))
1288 return -EOPNOTSUPP;
1289
1290 if (mtd->_write_oob)
1291 return mtd->_write_oob(mtd, to, ops);
1292 else
1293 return mtd->_write(mtd, to, ops->len, &ops->retlen,
1294 ops->datbuf);
1295}
1296EXPORT_SYMBOL_GPL(mtd_write_oob);
1297
1298/**
1299 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1300 * @mtd: MTD device structure
1301 * @section: ECC section. Depending on the layout you may have all the ECC
1302 * bytes stored in a single contiguous section, or one section
1303 * per ECC chunk (and sometime several sections for a single ECC
1304 * ECC chunk)
1305 * @oobecc: OOB region struct filled with the appropriate ECC position
1306 * information
1307 *
1308 * This function returns ECC section information in the OOB area. If you want
1309 * to get all the ECC bytes information, then you should call
1310 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1311 *
1312 * Returns zero on success, a negative error code otherwise.
1313 */
1314int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1315 struct mtd_oob_region *oobecc)
1316{
1317 memset(oobecc, 0, sizeof(*oobecc));
1318
1319 if (!mtd || section < 0)
1320 return -EINVAL;
1321
1322 if (!mtd->ooblayout || !mtd->ooblayout->ecc)
1323 return -ENOTSUPP;
1324
1325 return mtd->ooblayout->ecc(mtd, section, oobecc);
1326}
1327EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1328
1329/**
1330 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1331 * section
1332 * @mtd: MTD device structure
1333 * @section: Free section you are interested in. Depending on the layout
1334 * you may have all the free bytes stored in a single contiguous
1335 * section, or one section per ECC chunk plus an extra section
1336 * for the remaining bytes (or other funky layout).
1337 * @oobfree: OOB region struct filled with the appropriate free position
1338 * information
1339 *
1340 * This function returns free bytes position in the OOB area. If you want
1341 * to get all the free bytes information, then you should call
1342 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1343 *
1344 * Returns zero on success, a negative error code otherwise.
1345 */
1346int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1347 struct mtd_oob_region *oobfree)
1348{
1349 memset(oobfree, 0, sizeof(*oobfree));
1350
1351 if (!mtd || section < 0)
1352 return -EINVAL;
1353
1354 if (!mtd->ooblayout || !mtd->ooblayout->free)
1355 return -ENOTSUPP;
1356
1357 return mtd->ooblayout->free(mtd, section, oobfree);
1358}
1359EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1360
1361/**
1362 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1363 * @mtd: mtd info structure
1364 * @byte: the byte we are searching for
1365 * @sectionp: pointer where the section id will be stored
1366 * @oobregion: used to retrieve the ECC position
1367 * @iter: iterator function. Should be either mtd_ooblayout_free or
1368 * mtd_ooblayout_ecc depending on the region type you're searching for
1369 *
1370 * This function returns the section id and oobregion information of a
1371 * specific byte. For example, say you want to know where the 4th ECC byte is
1372 * stored, you'll use:
1373 *
1374 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1375 *
1376 * Returns zero on success, a negative error code otherwise.
1377 */
1378static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1379 int *sectionp, struct mtd_oob_region *oobregion,
1380 int (*iter)(struct mtd_info *,
1381 int section,
1382 struct mtd_oob_region *oobregion))
1383{
1384 int pos = 0, ret, section = 0;
1385
1386 memset(oobregion, 0, sizeof(*oobregion));
1387
1388 while (1) {
1389 ret = iter(mtd, section, oobregion);
1390 if (ret)
1391 return ret;
1392
1393 if (pos + oobregion->length > byte)
1394 break;
1395
1396 pos += oobregion->length;
1397 section++;
1398 }
1399
1400 /*
1401 * Adjust region info to make it start at the beginning at the
1402 * 'start' ECC byte.
1403 */
1404 oobregion->offset += byte - pos;
1405 oobregion->length -= byte - pos;
1406 *sectionp = section;
1407
1408 return 0;
1409}
1410
1411/**
1412 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1413 * ECC byte
1414 * @mtd: mtd info structure
1415 * @eccbyte: the byte we are searching for
1416 * @sectionp: pointer where the section id will be stored
1417 * @oobregion: OOB region information
1418 *
1419 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1420 * byte.
1421 *
1422 * Returns zero on success, a negative error code otherwise.
1423 */
1424int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1425 int *section,
1426 struct mtd_oob_region *oobregion)
1427{
1428 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1429 mtd_ooblayout_ecc);
1430}
1431EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1432
1433/**
1434 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1435 * @mtd: mtd info structure
1436 * @buf: destination buffer to store OOB bytes
1437 * @oobbuf: OOB buffer
1438 * @start: first byte to retrieve
1439 * @nbytes: number of bytes to retrieve
1440 * @iter: section iterator
1441 *
1442 * Extract bytes attached to a specific category (ECC or free)
1443 * from the OOB buffer and copy them into buf.
1444 *
1445 * Returns zero on success, a negative error code otherwise.
1446 */
1447static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1448 const u8 *oobbuf, int start, int nbytes,
1449 int (*iter)(struct mtd_info *,
1450 int section,
1451 struct mtd_oob_region *oobregion))
1452{
1453 struct mtd_oob_region oobregion;
1454 int section, ret;
1455
1456 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1457 &oobregion, iter);
1458
1459 while (!ret) {
1460 int cnt;
1461
1462 cnt = min_t(int, nbytes, oobregion.length);
1463 memcpy(buf, oobbuf + oobregion.offset, cnt);
1464 buf += cnt;
1465 nbytes -= cnt;
1466
1467 if (!nbytes)
1468 break;
1469
1470 ret = iter(mtd, ++section, &oobregion);
1471 }
1472
1473 return ret;
1474}
1475
1476/**
1477 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1478 * @mtd: mtd info structure
1479 * @buf: source buffer to get OOB bytes from
1480 * @oobbuf: OOB buffer
1481 * @start: first OOB byte to set
1482 * @nbytes: number of OOB bytes to set
1483 * @iter: section iterator
1484 *
1485 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1486 * is selected by passing the appropriate iterator.
1487 *
1488 * Returns zero on success, a negative error code otherwise.
1489 */
1490static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1491 u8 *oobbuf, int start, int nbytes,
1492 int (*iter)(struct mtd_info *,
1493 int section,
1494 struct mtd_oob_region *oobregion))
1495{
1496 struct mtd_oob_region oobregion;
1497 int section, ret;
1498
1499 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1500 &oobregion, iter);
1501
1502 while (!ret) {
1503 int cnt;
1504
1505 cnt = min_t(int, nbytes, oobregion.length);
1506 memcpy(oobbuf + oobregion.offset, buf, cnt);
1507 buf += cnt;
1508 nbytes -= cnt;
1509
1510 if (!nbytes)
1511 break;
1512
1513 ret = iter(mtd, ++section, &oobregion);
1514 }
1515
1516 return ret;
1517}
1518
1519/**
1520 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1521 * @mtd: mtd info structure
1522 * @iter: category iterator
1523 *
1524 * Count the number of bytes in a given category.
1525 *
1526 * Returns a positive value on success, a negative error code otherwise.
1527 */
1528static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1529 int (*iter)(struct mtd_info *,
1530 int section,
1531 struct mtd_oob_region *oobregion))
1532{
1533 struct mtd_oob_region oobregion;
1534 int section = 0, ret, nbytes = 0;
1535
1536 while (1) {
1537 ret = iter(mtd, section++, &oobregion);
1538 if (ret) {
1539 if (ret == -ERANGE)
1540 ret = nbytes;
1541 break;
1542 }
1543
1544 nbytes += oobregion.length;
1545 }
1546
1547 return ret;
1548}
1549
1550/**
1551 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1552 * @mtd: mtd info structure
1553 * @eccbuf: destination buffer to store ECC bytes
1554 * @oobbuf: OOB buffer
1555 * @start: first ECC byte to retrieve
1556 * @nbytes: number of ECC bytes to retrieve
1557 *
1558 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1559 *
1560 * Returns zero on success, a negative error code otherwise.
1561 */
1562int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1563 const u8 *oobbuf, int start, int nbytes)
1564{
1565 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1566 mtd_ooblayout_ecc);
1567}
1568EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1569
1570/**
1571 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1572 * @mtd: mtd info structure
1573 * @eccbuf: source buffer to get ECC bytes from
1574 * @oobbuf: OOB buffer
1575 * @start: first ECC byte to set
1576 * @nbytes: number of ECC bytes to set
1577 *
1578 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1579 *
1580 * Returns zero on success, a negative error code otherwise.
1581 */
1582int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1583 u8 *oobbuf, int start, int nbytes)
1584{
1585 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1586 mtd_ooblayout_ecc);
1587}
1588EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1589
1590/**
1591 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1592 * @mtd: mtd info structure
1593 * @databuf: destination buffer to store ECC bytes
1594 * @oobbuf: OOB buffer
1595 * @start: first ECC byte to retrieve
1596 * @nbytes: number of ECC bytes to retrieve
1597 *
1598 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1599 *
1600 * Returns zero on success, a negative error code otherwise.
1601 */
1602int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1603 const u8 *oobbuf, int start, int nbytes)
1604{
1605 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1606 mtd_ooblayout_free);
1607}
1608EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1609
1610/**
1611 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1612 * @mtd: mtd info structure
1613 * @databuf: source buffer to get data bytes from
1614 * @oobbuf: OOB buffer
1615 * @start: first ECC byte to set
1616 * @nbytes: number of ECC bytes to set
1617 *
1618 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1619 *
1620 * Returns zero on success, a negative error code otherwise.
1621 */
1622int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1623 u8 *oobbuf, int start, int nbytes)
1624{
1625 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1626 mtd_ooblayout_free);
1627}
1628EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1629
1630/**
1631 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1632 * @mtd: mtd info structure
1633 *
1634 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1635 *
1636 * Returns zero on success, a negative error code otherwise.
1637 */
1638int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1639{
1640 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1641}
1642EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1643
1644/**
1645 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1646 * @mtd: mtd info structure
1647 *
1648 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1649 *
1650 * Returns zero on success, a negative error code otherwise.
1651 */
1652int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1653{
1654 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1655}
1656EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1657
1658/*
1659 * Method to access the protection register area, present in some flash
1660 * devices. The user data is one time programmable but the factory data is read
1661 * only.
1662 */
1663int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1664 struct otp_info *buf)
1665{
1666 if (!mtd->_get_fact_prot_info)
1667 return -EOPNOTSUPP;
1668 if (!len)
1669 return 0;
1670 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1671}
1672EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1673
1674int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1675 size_t *retlen, u_char *buf)
1676{
1677 *retlen = 0;
1678 if (!mtd->_read_fact_prot_reg)
1679 return -EOPNOTSUPP;
1680 if (!len)
1681 return 0;
1682 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1683}
1684EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1685
1686int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1687 struct otp_info *buf)
1688{
1689 if (!mtd->_get_user_prot_info)
1690 return -EOPNOTSUPP;
1691 if (!len)
1692 return 0;
1693 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1694}
1695EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1696
1697int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1698 size_t *retlen, u_char *buf)
1699{
1700 *retlen = 0;
1701 if (!mtd->_read_user_prot_reg)
1702 return -EOPNOTSUPP;
1703 if (!len)
1704 return 0;
1705 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1706}
1707EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1708
1709int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1710 size_t *retlen, u_char *buf)
1711{
1712 int ret;
1713
1714 *retlen = 0;
1715 if (!mtd->_write_user_prot_reg)
1716 return -EOPNOTSUPP;
1717 if (!len)
1718 return 0;
1719 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1720 if (ret)
1721 return ret;
1722
1723 /*
1724 * If no data could be written at all, we are out of memory and
1725 * must return -ENOSPC.
1726 */
1727 return (*retlen) ? 0 : -ENOSPC;
1728}
1729EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1730
1731int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1732{
1733 if (!mtd->_lock_user_prot_reg)
1734 return -EOPNOTSUPP;
1735 if (!len)
1736 return 0;
1737 return mtd->_lock_user_prot_reg(mtd, from, len);
1738}
1739EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1740
1741/* Chip-supported device locking */
1742int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1743{
1744 if (!mtd->_lock)
1745 return -EOPNOTSUPP;
1746 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1747 return -EINVAL;
1748 if (!len)
1749 return 0;
1750 return mtd->_lock(mtd, ofs, len);
1751}
1752EXPORT_SYMBOL_GPL(mtd_lock);
1753
1754int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1755{
1756 if (!mtd->_unlock)
1757 return -EOPNOTSUPP;
1758 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1759 return -EINVAL;
1760 if (!len)
1761 return 0;
1762 return mtd->_unlock(mtd, ofs, len);
1763}
1764EXPORT_SYMBOL_GPL(mtd_unlock);
1765
1766int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1767{
1768 if (!mtd->_is_locked)
1769 return -EOPNOTSUPP;
1770 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1771 return -EINVAL;
1772 if (!len)
1773 return 0;
1774 return mtd->_is_locked(mtd, ofs, len);
1775}
1776EXPORT_SYMBOL_GPL(mtd_is_locked);
1777
1778int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1779{
1780 if (ofs < 0 || ofs >= mtd->size)
1781 return -EINVAL;
1782 if (!mtd->_block_isreserved)
1783 return 0;
1784 return mtd->_block_isreserved(mtd, ofs);
1785}
1786EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1787
1788int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1789{
1790 if (ofs < 0 || ofs >= mtd->size)
1791 return -EINVAL;
1792 if (!mtd->_block_isbad)
1793 return 0;
1794 return mtd->_block_isbad(mtd, ofs);
1795}
1796EXPORT_SYMBOL_GPL(mtd_block_isbad);
1797
1798int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1799{
1800 if (!mtd->_block_markbad)
1801 return -EOPNOTSUPP;
1802 if (ofs < 0 || ofs >= mtd->size)
1803 return -EINVAL;
1804 if (!(mtd->flags & MTD_WRITEABLE))
1805 return -EROFS;
1806 return mtd->_block_markbad(mtd, ofs);
1807}
1808EXPORT_SYMBOL_GPL(mtd_block_markbad);
1809
1810/*
1811 * default_mtd_writev - the default writev method
1812 * @mtd: mtd device description object pointer
1813 * @vecs: the vectors to write
1814 * @count: count of vectors in @vecs
1815 * @to: the MTD device offset to write to
1816 * @retlen: on exit contains the count of bytes written to the MTD device.
1817 *
1818 * This function returns zero in case of success and a negative error code in
1819 * case of failure.
1820 */
1821static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1822 unsigned long count, loff_t to, size_t *retlen)
1823{
1824 unsigned long i;
1825 size_t totlen = 0, thislen;
1826 int ret = 0;
1827
1828 for (i = 0; i < count; i++) {
1829 if (!vecs[i].iov_len)
1830 continue;
1831 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1832 vecs[i].iov_base);
1833 totlen += thislen;
1834 if (ret || thislen != vecs[i].iov_len)
1835 break;
1836 to += vecs[i].iov_len;
1837 }
1838 *retlen = totlen;
1839 return ret;
1840}
1841
1842/*
1843 * mtd_writev - the vector-based MTD write method
1844 * @mtd: mtd device description object pointer
1845 * @vecs: the vectors to write
1846 * @count: count of vectors in @vecs
1847 * @to: the MTD device offset to write to
1848 * @retlen: on exit contains the count of bytes written to the MTD device.
1849 *
1850 * This function returns zero in case of success and a negative error code in
1851 * case of failure.
1852 */
1853int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1854 unsigned long count, loff_t to, size_t *retlen)
1855{
1856 *retlen = 0;
1857 if (!(mtd->flags & MTD_WRITEABLE))
1858 return -EROFS;
1859 if (!mtd->_writev)
1860 return default_mtd_writev(mtd, vecs, count, to, retlen);
1861 return mtd->_writev(mtd, vecs, count, to, retlen);
1862}
1863EXPORT_SYMBOL_GPL(mtd_writev);
1864
1865/**
1866 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1867 * @mtd: mtd device description object pointer
1868 * @size: a pointer to the ideal or maximum size of the allocation, points
1869 * to the actual allocation size on success.
1870 *
1871 * This routine attempts to allocate a contiguous kernel buffer up to
1872 * the specified size, backing off the size of the request exponentially
1873 * until the request succeeds or until the allocation size falls below
1874 * the system page size. This attempts to make sure it does not adversely
1875 * impact system performance, so when allocating more than one page, we
1876 * ask the memory allocator to avoid re-trying, swapping, writing back
1877 * or performing I/O.
1878 *
1879 * Note, this function also makes sure that the allocated buffer is aligned to
1880 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1881 *
1882 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1883 * to handle smaller (i.e. degraded) buffer allocations under low- or
1884 * fragmented-memory situations where such reduced allocations, from a
1885 * requested ideal, are allowed.
1886 *
1887 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1888 */
1889void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1890{
1891 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1892 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1893 void *kbuf;
1894
1895 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1896
1897 while (*size > min_alloc) {
1898 kbuf = kmalloc(*size, flags);
1899 if (kbuf)
1900 return kbuf;
1901
1902 *size >>= 1;
1903 *size = ALIGN(*size, mtd->writesize);
1904 }
1905
1906 /*
1907 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1908 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1909 */
1910 return kmalloc(*size, GFP_KERNEL);
1911}
1912EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1913
1914#ifdef CONFIG_PROC_FS
1915
1916/*====================================================================*/
1917/* Support for /proc/mtd */
1918
1919static int mtd_proc_show(struct seq_file *m, void *v)
1920{
1921 struct mtd_info *mtd;
1922
1923 seq_puts(m, "dev: size erasesize name\n");
1924 mutex_lock(&mtd_table_mutex);
1925 mtd_for_each_device(mtd) {
1926 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1927 mtd->index, (unsigned long long)mtd->size,
1928 mtd->erasesize, mtd->name);
1929 }
1930 mutex_unlock(&mtd_table_mutex);
1931 return 0;
1932}
1933#endif /* CONFIG_PROC_FS */
1934
1935/*====================================================================*/
1936/* Init code */
1937
1938static struct backing_dev_info * __init mtd_bdi_init(char *name)
1939{
1940 struct backing_dev_info *bdi;
1941 int ret;
1942
1943 bdi = bdi_alloc(GFP_KERNEL);
1944 if (!bdi)
1945 return ERR_PTR(-ENOMEM);
1946
1947 bdi->name = name;
1948 /*
1949 * We put '-0' suffix to the name to get the same name format as we
1950 * used to get. Since this is called only once, we get a unique name.
1951 */
1952 ret = bdi_register(bdi, "%.28s-0", name);
1953 if (ret)
1954 bdi_put(bdi);
1955
1956 return ret ? ERR_PTR(ret) : bdi;
1957}
1958
1959static struct proc_dir_entry *proc_mtd;
1960
1961static int __init init_mtd(void)
1962{
1963 int ret;
1964
1965 ret = class_register(&mtd_class);
1966 if (ret)
1967 goto err_reg;
1968
1969 mtd_bdi = mtd_bdi_init("mtd");
1970 if (IS_ERR(mtd_bdi)) {
1971 ret = PTR_ERR(mtd_bdi);
1972 goto err_bdi;
1973 }
1974
1975 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
1976
1977 ret = init_mtdchar();
1978 if (ret)
1979 goto out_procfs;
1980
1981 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
1982
1983 return 0;
1984
1985out_procfs:
1986 if (proc_mtd)
1987 remove_proc_entry("mtd", NULL);
1988 bdi_put(mtd_bdi);
1989err_bdi:
1990 class_unregister(&mtd_class);
1991err_reg:
1992 pr_err("Error registering mtd class or bdi: %d\n", ret);
1993 return ret;
1994}
1995
1996static void __exit cleanup_mtd(void)
1997{
1998 debugfs_remove_recursive(dfs_dir_mtd);
1999 cleanup_mtdchar();
2000 if (proc_mtd)
2001 remove_proc_entry("mtd", NULL);
2002 class_unregister(&mtd_class);
2003 bdi_put(mtd_bdi);
2004 idr_destroy(&mtd_idr);
2005}
2006
2007module_init(init_mtd);
2008module_exit(cleanup_mtd);
2009
2010MODULE_LICENSE("GPL");
2011MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2012MODULE_DESCRIPTION("Core MTD registration and access routines");