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1/*
2 * Core registration and callback routines for MTD
3 * drivers and users.
4 *
5 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
6 * Copyright © 2006 Red Hat UK Limited
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24#include <linux/module.h>
25#include <linux/kernel.h>
26#include <linux/ptrace.h>
27#include <linux/seq_file.h>
28#include <linux/string.h>
29#include <linux/timer.h>
30#include <linux/major.h>
31#include <linux/fs.h>
32#include <linux/err.h>
33#include <linux/ioctl.h>
34#include <linux/init.h>
35#include <linux/proc_fs.h>
36#include <linux/idr.h>
37#include <linux/backing-dev.h>
38#include <linux/gfp.h>
39
40#include <linux/mtd/mtd.h>
41#include <linux/mtd/partitions.h>
42
43#include "mtdcore.h"
44/*
45 * backing device capabilities for non-mappable devices (such as NAND flash)
46 * - permits private mappings, copies are taken of the data
47 */
48static struct backing_dev_info mtd_bdi_unmappable = {
49 .capabilities = BDI_CAP_MAP_COPY,
50};
51
52/*
53 * backing device capabilities for R/O mappable devices (such as ROM)
54 * - permits private mappings, copies are taken of the data
55 * - permits non-writable shared mappings
56 */
57static struct backing_dev_info mtd_bdi_ro_mappable = {
58 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
59 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
60};
61
62/*
63 * backing device capabilities for writable mappable devices (such as RAM)
64 * - permits private mappings, copies are taken of the data
65 * - permits non-writable shared mappings
66 */
67static struct backing_dev_info mtd_bdi_rw_mappable = {
68 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
69 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
70 BDI_CAP_WRITE_MAP),
71};
72
73static int mtd_cls_suspend(struct device *dev, pm_message_t state);
74static int mtd_cls_resume(struct device *dev);
75
76static struct class mtd_class = {
77 .name = "mtd",
78 .owner = THIS_MODULE,
79 .suspend = mtd_cls_suspend,
80 .resume = mtd_cls_resume,
81};
82
83static DEFINE_IDR(mtd_idr);
84
85/* These are exported solely for the purpose of mtd_blkdevs.c. You
86 should not use them for _anything_ else */
87DEFINE_MUTEX(mtd_table_mutex);
88EXPORT_SYMBOL_GPL(mtd_table_mutex);
89
90struct mtd_info *__mtd_next_device(int i)
91{
92 return idr_get_next(&mtd_idr, &i);
93}
94EXPORT_SYMBOL_GPL(__mtd_next_device);
95
96static LIST_HEAD(mtd_notifiers);
97
98
99#if defined(CONFIG_MTD_CHAR) || defined(CONFIG_MTD_CHAR_MODULE)
100#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
101#else
102#define MTD_DEVT(index) 0
103#endif
104
105/* REVISIT once MTD uses the driver model better, whoever allocates
106 * the mtd_info will probably want to use the release() hook...
107 */
108static void mtd_release(struct device *dev)
109{
110 dev_t index = MTD_DEVT(dev_to_mtd(dev)->index);
111
112 /* remove /dev/mtdXro node if needed */
113 if (index)
114 device_destroy(&mtd_class, index + 1);
115}
116
117static int mtd_cls_suspend(struct device *dev, pm_message_t state)
118{
119 struct mtd_info *mtd = dev_to_mtd(dev);
120
121 if (mtd && mtd->suspend)
122 return mtd->suspend(mtd);
123 else
124 return 0;
125}
126
127static int mtd_cls_resume(struct device *dev)
128{
129 struct mtd_info *mtd = dev_to_mtd(dev);
130
131 if (mtd && mtd->resume)
132 mtd->resume(mtd);
133 return 0;
134}
135
136static ssize_t mtd_type_show(struct device *dev,
137 struct device_attribute *attr, char *buf)
138{
139 struct mtd_info *mtd = dev_to_mtd(dev);
140 char *type;
141
142 switch (mtd->type) {
143 case MTD_ABSENT:
144 type = "absent";
145 break;
146 case MTD_RAM:
147 type = "ram";
148 break;
149 case MTD_ROM:
150 type = "rom";
151 break;
152 case MTD_NORFLASH:
153 type = "nor";
154 break;
155 case MTD_NANDFLASH:
156 type = "nand";
157 break;
158 case MTD_DATAFLASH:
159 type = "dataflash";
160 break;
161 case MTD_UBIVOLUME:
162 type = "ubi";
163 break;
164 default:
165 type = "unknown";
166 }
167
168 return snprintf(buf, PAGE_SIZE, "%s\n", type);
169}
170static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
171
172static ssize_t mtd_flags_show(struct device *dev,
173 struct device_attribute *attr, char *buf)
174{
175 struct mtd_info *mtd = dev_to_mtd(dev);
176
177 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
178
179}
180static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
181
182static ssize_t mtd_size_show(struct device *dev,
183 struct device_attribute *attr, char *buf)
184{
185 struct mtd_info *mtd = dev_to_mtd(dev);
186
187 return snprintf(buf, PAGE_SIZE, "%llu\n",
188 (unsigned long long)mtd->size);
189
190}
191static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
192
193static ssize_t mtd_erasesize_show(struct device *dev,
194 struct device_attribute *attr, char *buf)
195{
196 struct mtd_info *mtd = dev_to_mtd(dev);
197
198 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
199
200}
201static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
202
203static ssize_t mtd_writesize_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
205{
206 struct mtd_info *mtd = dev_to_mtd(dev);
207
208 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
209
210}
211static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
212
213static ssize_t mtd_subpagesize_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
215{
216 struct mtd_info *mtd = dev_to_mtd(dev);
217 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
218
219 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
220
221}
222static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
223
224static ssize_t mtd_oobsize_show(struct device *dev,
225 struct device_attribute *attr, char *buf)
226{
227 struct mtd_info *mtd = dev_to_mtd(dev);
228
229 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
230
231}
232static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
233
234static ssize_t mtd_numeraseregions_show(struct device *dev,
235 struct device_attribute *attr, char *buf)
236{
237 struct mtd_info *mtd = dev_to_mtd(dev);
238
239 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
240
241}
242static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
243 NULL);
244
245static ssize_t mtd_name_show(struct device *dev,
246 struct device_attribute *attr, char *buf)
247{
248 struct mtd_info *mtd = dev_to_mtd(dev);
249
250 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
251
252}
253static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
254
255static struct attribute *mtd_attrs[] = {
256 &dev_attr_type.attr,
257 &dev_attr_flags.attr,
258 &dev_attr_size.attr,
259 &dev_attr_erasesize.attr,
260 &dev_attr_writesize.attr,
261 &dev_attr_subpagesize.attr,
262 &dev_attr_oobsize.attr,
263 &dev_attr_numeraseregions.attr,
264 &dev_attr_name.attr,
265 NULL,
266};
267
268static struct attribute_group mtd_group = {
269 .attrs = mtd_attrs,
270};
271
272static const struct attribute_group *mtd_groups[] = {
273 &mtd_group,
274 NULL,
275};
276
277static struct device_type mtd_devtype = {
278 .name = "mtd",
279 .groups = mtd_groups,
280 .release = mtd_release,
281};
282
283/**
284 * add_mtd_device - register an MTD device
285 * @mtd: pointer to new MTD device info structure
286 *
287 * Add a device to the list of MTD devices present in the system, and
288 * notify each currently active MTD 'user' of its arrival. Returns
289 * zero on success or 1 on failure, which currently will only happen
290 * if there is insufficient memory or a sysfs error.
291 */
292
293int add_mtd_device(struct mtd_info *mtd)
294{
295 struct mtd_notifier *not;
296 int i, error;
297
298 if (!mtd->backing_dev_info) {
299 switch (mtd->type) {
300 case MTD_RAM:
301 mtd->backing_dev_info = &mtd_bdi_rw_mappable;
302 break;
303 case MTD_ROM:
304 mtd->backing_dev_info = &mtd_bdi_ro_mappable;
305 break;
306 default:
307 mtd->backing_dev_info = &mtd_bdi_unmappable;
308 break;
309 }
310 }
311
312 BUG_ON(mtd->writesize == 0);
313 mutex_lock(&mtd_table_mutex);
314
315 do {
316 if (!idr_pre_get(&mtd_idr, GFP_KERNEL))
317 goto fail_locked;
318 error = idr_get_new(&mtd_idr, mtd, &i);
319 } while (error == -EAGAIN);
320
321 if (error)
322 goto fail_locked;
323
324 mtd->index = i;
325 mtd->usecount = 0;
326
327 if (is_power_of_2(mtd->erasesize))
328 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
329 else
330 mtd->erasesize_shift = 0;
331
332 if (is_power_of_2(mtd->writesize))
333 mtd->writesize_shift = ffs(mtd->writesize) - 1;
334 else
335 mtd->writesize_shift = 0;
336
337 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
338 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
339
340 /* Some chips always power up locked. Unlock them now */
341 if ((mtd->flags & MTD_WRITEABLE)
342 && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
343 if (mtd->unlock(mtd, 0, mtd->size))
344 printk(KERN_WARNING
345 "%s: unlock failed, writes may not work\n",
346 mtd->name);
347 }
348
349 /* Caller should have set dev.parent to match the
350 * physical device.
351 */
352 mtd->dev.type = &mtd_devtype;
353 mtd->dev.class = &mtd_class;
354 mtd->dev.devt = MTD_DEVT(i);
355 dev_set_name(&mtd->dev, "mtd%d", i);
356 dev_set_drvdata(&mtd->dev, mtd);
357 if (device_register(&mtd->dev) != 0)
358 goto fail_added;
359
360 if (MTD_DEVT(i))
361 device_create(&mtd_class, mtd->dev.parent,
362 MTD_DEVT(i) + 1,
363 NULL, "mtd%dro", i);
364
365 DEBUG(0, "mtd: Giving out device %d to %s\n", i, mtd->name);
366 /* No need to get a refcount on the module containing
367 the notifier, since we hold the mtd_table_mutex */
368 list_for_each_entry(not, &mtd_notifiers, list)
369 not->add(mtd);
370
371 mutex_unlock(&mtd_table_mutex);
372 /* We _know_ we aren't being removed, because
373 our caller is still holding us here. So none
374 of this try_ nonsense, and no bitching about it
375 either. :) */
376 __module_get(THIS_MODULE);
377 return 0;
378
379fail_added:
380 idr_remove(&mtd_idr, i);
381fail_locked:
382 mutex_unlock(&mtd_table_mutex);
383 return 1;
384}
385
386/**
387 * del_mtd_device - unregister an MTD device
388 * @mtd: pointer to MTD device info structure
389 *
390 * Remove a device from the list of MTD devices present in the system,
391 * and notify each currently active MTD 'user' of its departure.
392 * Returns zero on success or 1 on failure, which currently will happen
393 * if the requested device does not appear to be present in the list.
394 */
395
396int del_mtd_device(struct mtd_info *mtd)
397{
398 int ret;
399 struct mtd_notifier *not;
400
401 mutex_lock(&mtd_table_mutex);
402
403 if (idr_find(&mtd_idr, mtd->index) != mtd) {
404 ret = -ENODEV;
405 goto out_error;
406 }
407
408 /* No need to get a refcount on the module containing
409 the notifier, since we hold the mtd_table_mutex */
410 list_for_each_entry(not, &mtd_notifiers, list)
411 not->remove(mtd);
412
413 if (mtd->usecount) {
414 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
415 mtd->index, mtd->name, mtd->usecount);
416 ret = -EBUSY;
417 } else {
418 device_unregister(&mtd->dev);
419
420 idr_remove(&mtd_idr, mtd->index);
421
422 module_put(THIS_MODULE);
423 ret = 0;
424 }
425
426out_error:
427 mutex_unlock(&mtd_table_mutex);
428 return ret;
429}
430
431/**
432 * mtd_device_register - register an MTD device.
433 *
434 * @master: the MTD device to register
435 * @parts: the partitions to register - only valid if nr_parts > 0
436 * @nr_parts: the number of partitions in parts. If zero then the full MTD
437 * device is registered
438 *
439 * Register an MTD device with the system and optionally, a number of
440 * partitions. If nr_parts is 0 then the whole device is registered, otherwise
441 * only the partitions are registered. To register both the full device *and*
442 * the partitions, call mtd_device_register() twice, once with nr_parts == 0
443 * and once equal to the number of partitions.
444 */
445int mtd_device_register(struct mtd_info *master,
446 const struct mtd_partition *parts,
447 int nr_parts)
448{
449 return parts ? add_mtd_partitions(master, parts, nr_parts) :
450 add_mtd_device(master);
451}
452EXPORT_SYMBOL_GPL(mtd_device_register);
453
454/**
455 * mtd_device_unregister - unregister an existing MTD device.
456 *
457 * @master: the MTD device to unregister. This will unregister both the master
458 * and any partitions if registered.
459 */
460int mtd_device_unregister(struct mtd_info *master)
461{
462 int err;
463
464 err = del_mtd_partitions(master);
465 if (err)
466 return err;
467
468 if (!device_is_registered(&master->dev))
469 return 0;
470
471 return del_mtd_device(master);
472}
473EXPORT_SYMBOL_GPL(mtd_device_unregister);
474
475/**
476 * register_mtd_user - register a 'user' of MTD devices.
477 * @new: pointer to notifier info structure
478 *
479 * Registers a pair of callbacks function to be called upon addition
480 * or removal of MTD devices. Causes the 'add' callback to be immediately
481 * invoked for each MTD device currently present in the system.
482 */
483
484void register_mtd_user (struct mtd_notifier *new)
485{
486 struct mtd_info *mtd;
487
488 mutex_lock(&mtd_table_mutex);
489
490 list_add(&new->list, &mtd_notifiers);
491
492 __module_get(THIS_MODULE);
493
494 mtd_for_each_device(mtd)
495 new->add(mtd);
496
497 mutex_unlock(&mtd_table_mutex);
498}
499
500/**
501 * unregister_mtd_user - unregister a 'user' of MTD devices.
502 * @old: pointer to notifier info structure
503 *
504 * Removes a callback function pair from the list of 'users' to be
505 * notified upon addition or removal of MTD devices. Causes the
506 * 'remove' callback to be immediately invoked for each MTD device
507 * currently present in the system.
508 */
509
510int unregister_mtd_user (struct mtd_notifier *old)
511{
512 struct mtd_info *mtd;
513
514 mutex_lock(&mtd_table_mutex);
515
516 module_put(THIS_MODULE);
517
518 mtd_for_each_device(mtd)
519 old->remove(mtd);
520
521 list_del(&old->list);
522 mutex_unlock(&mtd_table_mutex);
523 return 0;
524}
525
526
527/**
528 * get_mtd_device - obtain a validated handle for an MTD device
529 * @mtd: last known address of the required MTD device
530 * @num: internal device number of the required MTD device
531 *
532 * Given a number and NULL address, return the num'th entry in the device
533 * table, if any. Given an address and num == -1, search the device table
534 * for a device with that address and return if it's still present. Given
535 * both, return the num'th driver only if its address matches. Return
536 * error code if not.
537 */
538
539struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
540{
541 struct mtd_info *ret = NULL, *other;
542 int err = -ENODEV;
543
544 mutex_lock(&mtd_table_mutex);
545
546 if (num == -1) {
547 mtd_for_each_device(other) {
548 if (other == mtd) {
549 ret = mtd;
550 break;
551 }
552 }
553 } else if (num >= 0) {
554 ret = idr_find(&mtd_idr, num);
555 if (mtd && mtd != ret)
556 ret = NULL;
557 }
558
559 if (!ret) {
560 ret = ERR_PTR(err);
561 goto out;
562 }
563
564 err = __get_mtd_device(ret);
565 if (err)
566 ret = ERR_PTR(err);
567out:
568 mutex_unlock(&mtd_table_mutex);
569 return ret;
570}
571
572
573int __get_mtd_device(struct mtd_info *mtd)
574{
575 int err;
576
577 if (!try_module_get(mtd->owner))
578 return -ENODEV;
579
580 if (mtd->get_device) {
581 err = mtd->get_device(mtd);
582
583 if (err) {
584 module_put(mtd->owner);
585 return err;
586 }
587 }
588 mtd->usecount++;
589 return 0;
590}
591
592/**
593 * get_mtd_device_nm - obtain a validated handle for an MTD device by
594 * device name
595 * @name: MTD device name to open
596 *
597 * This function returns MTD device description structure in case of
598 * success and an error code in case of failure.
599 */
600
601struct mtd_info *get_mtd_device_nm(const char *name)
602{
603 int err = -ENODEV;
604 struct mtd_info *mtd = NULL, *other;
605
606 mutex_lock(&mtd_table_mutex);
607
608 mtd_for_each_device(other) {
609 if (!strcmp(name, other->name)) {
610 mtd = other;
611 break;
612 }
613 }
614
615 if (!mtd)
616 goto out_unlock;
617
618 err = __get_mtd_device(mtd);
619 if (err)
620 goto out_unlock;
621
622 mutex_unlock(&mtd_table_mutex);
623 return mtd;
624
625out_unlock:
626 mutex_unlock(&mtd_table_mutex);
627 return ERR_PTR(err);
628}
629
630void put_mtd_device(struct mtd_info *mtd)
631{
632 mutex_lock(&mtd_table_mutex);
633 __put_mtd_device(mtd);
634 mutex_unlock(&mtd_table_mutex);
635
636}
637
638void __put_mtd_device(struct mtd_info *mtd)
639{
640 --mtd->usecount;
641 BUG_ON(mtd->usecount < 0);
642
643 if (mtd->put_device)
644 mtd->put_device(mtd);
645
646 module_put(mtd->owner);
647}
648
649/* default_mtd_writev - default mtd writev method for MTD devices that
650 * don't implement their own
651 */
652
653int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
654 unsigned long count, loff_t to, size_t *retlen)
655{
656 unsigned long i;
657 size_t totlen = 0, thislen;
658 int ret = 0;
659
660 if(!mtd->write) {
661 ret = -EROFS;
662 } else {
663 for (i=0; i<count; i++) {
664 if (!vecs[i].iov_len)
665 continue;
666 ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
667 totlen += thislen;
668 if (ret || thislen != vecs[i].iov_len)
669 break;
670 to += vecs[i].iov_len;
671 }
672 }
673 if (retlen)
674 *retlen = totlen;
675 return ret;
676}
677
678/**
679 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
680 * @size: A pointer to the ideal or maximum size of the allocation. Points
681 * to the actual allocation size on success.
682 *
683 * This routine attempts to allocate a contiguous kernel buffer up to
684 * the specified size, backing off the size of the request exponentially
685 * until the request succeeds or until the allocation size falls below
686 * the system page size. This attempts to make sure it does not adversely
687 * impact system performance, so when allocating more than one page, we
688 * ask the memory allocator to avoid re-trying, swapping, writing back
689 * or performing I/O.
690 *
691 * Note, this function also makes sure that the allocated buffer is aligned to
692 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
693 *
694 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
695 * to handle smaller (i.e. degraded) buffer allocations under low- or
696 * fragmented-memory situations where such reduced allocations, from a
697 * requested ideal, are allowed.
698 *
699 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
700 */
701void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
702{
703 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
704 __GFP_NORETRY | __GFP_NO_KSWAPD;
705 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
706 void *kbuf;
707
708 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
709
710 while (*size > min_alloc) {
711 kbuf = kmalloc(*size, flags);
712 if (kbuf)
713 return kbuf;
714
715 *size >>= 1;
716 *size = ALIGN(*size, mtd->writesize);
717 }
718
719 /*
720 * For the last resort allocation allow 'kmalloc()' to do all sorts of
721 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
722 */
723 return kmalloc(*size, GFP_KERNEL);
724}
725
726EXPORT_SYMBOL_GPL(get_mtd_device);
727EXPORT_SYMBOL_GPL(get_mtd_device_nm);
728EXPORT_SYMBOL_GPL(__get_mtd_device);
729EXPORT_SYMBOL_GPL(put_mtd_device);
730EXPORT_SYMBOL_GPL(__put_mtd_device);
731EXPORT_SYMBOL_GPL(register_mtd_user);
732EXPORT_SYMBOL_GPL(unregister_mtd_user);
733EXPORT_SYMBOL_GPL(default_mtd_writev);
734EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
735
736#ifdef CONFIG_PROC_FS
737
738/*====================================================================*/
739/* Support for /proc/mtd */
740
741static struct proc_dir_entry *proc_mtd;
742
743static int mtd_proc_show(struct seq_file *m, void *v)
744{
745 struct mtd_info *mtd;
746
747 seq_puts(m, "dev: size erasesize name\n");
748 mutex_lock(&mtd_table_mutex);
749 mtd_for_each_device(mtd) {
750 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
751 mtd->index, (unsigned long long)mtd->size,
752 mtd->erasesize, mtd->name);
753 }
754 mutex_unlock(&mtd_table_mutex);
755 return 0;
756}
757
758static int mtd_proc_open(struct inode *inode, struct file *file)
759{
760 return single_open(file, mtd_proc_show, NULL);
761}
762
763static const struct file_operations mtd_proc_ops = {
764 .open = mtd_proc_open,
765 .read = seq_read,
766 .llseek = seq_lseek,
767 .release = single_release,
768};
769#endif /* CONFIG_PROC_FS */
770
771/*====================================================================*/
772/* Init code */
773
774static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
775{
776 int ret;
777
778 ret = bdi_init(bdi);
779 if (!ret)
780 ret = bdi_register(bdi, NULL, name);
781
782 if (ret)
783 bdi_destroy(bdi);
784
785 return ret;
786}
787
788static int __init init_mtd(void)
789{
790 int ret;
791
792 ret = class_register(&mtd_class);
793 if (ret)
794 goto err_reg;
795
796 ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
797 if (ret)
798 goto err_bdi1;
799
800 ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
801 if (ret)
802 goto err_bdi2;
803
804 ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
805 if (ret)
806 goto err_bdi3;
807
808#ifdef CONFIG_PROC_FS
809 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
810#endif /* CONFIG_PROC_FS */
811 return 0;
812
813err_bdi3:
814 bdi_destroy(&mtd_bdi_ro_mappable);
815err_bdi2:
816 bdi_destroy(&mtd_bdi_unmappable);
817err_bdi1:
818 class_unregister(&mtd_class);
819err_reg:
820 pr_err("Error registering mtd class or bdi: %d\n", ret);
821 return ret;
822}
823
824static void __exit cleanup_mtd(void)
825{
826#ifdef CONFIG_PROC_FS
827 if (proc_mtd)
828 remove_proc_entry( "mtd", NULL);
829#endif /* CONFIG_PROC_FS */
830 class_unregister(&mtd_class);
831 bdi_destroy(&mtd_bdi_unmappable);
832 bdi_destroy(&mtd_bdi_ro_mappable);
833 bdi_destroy(&mtd_bdi_rw_mappable);
834}
835
836module_init(init_mtd);
837module_exit(cleanup_mtd);
838
839MODULE_LICENSE("GPL");
840MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
841MODULE_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/random.h>
27#include <linux/slab.h>
28#include <linux/reboot.h>
29#include <linux/leds.h>
30#include <linux/debugfs.h>
31#include <linux/nvmem-provider.h>
32#include <linux/root_dev.h>
33#include <linux/error-injection.h>
34
35#include <linux/mtd/mtd.h>
36#include <linux/mtd/partitions.h>
37
38#include "mtdcore.h"
39
40struct backing_dev_info *mtd_bdi;
41
42#ifdef CONFIG_PM_SLEEP
43
44static int mtd_cls_suspend(struct device *dev)
45{
46 struct mtd_info *mtd = dev_get_drvdata(dev);
47
48 return mtd ? mtd_suspend(mtd) : 0;
49}
50
51static int mtd_cls_resume(struct device *dev)
52{
53 struct mtd_info *mtd = dev_get_drvdata(dev);
54
55 if (mtd)
56 mtd_resume(mtd);
57 return 0;
58}
59
60static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
61#define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
62#else
63#define MTD_CLS_PM_OPS NULL
64#endif
65
66static struct class mtd_class = {
67 .name = "mtd",
68 .pm = MTD_CLS_PM_OPS,
69};
70
71static DEFINE_IDR(mtd_idr);
72
73/* These are exported solely for the purpose of mtd_blkdevs.c. You
74 should not use them for _anything_ else */
75DEFINE_MUTEX(mtd_table_mutex);
76EXPORT_SYMBOL_GPL(mtd_table_mutex);
77
78struct mtd_info *__mtd_next_device(int i)
79{
80 return idr_get_next(&mtd_idr, &i);
81}
82EXPORT_SYMBOL_GPL(__mtd_next_device);
83
84static LIST_HEAD(mtd_notifiers);
85
86
87#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
88
89/* REVISIT once MTD uses the driver model better, whoever allocates
90 * the mtd_info will probably want to use the release() hook...
91 */
92static void mtd_release(struct device *dev)
93{
94 struct mtd_info *mtd = dev_get_drvdata(dev);
95 dev_t index = MTD_DEVT(mtd->index);
96
97 idr_remove(&mtd_idr, mtd->index);
98 of_node_put(mtd_get_of_node(mtd));
99
100 if (mtd_is_partition(mtd))
101 release_mtd_partition(mtd);
102
103 /* remove /dev/mtdXro node */
104 device_destroy(&mtd_class, index + 1);
105}
106
107static void mtd_device_release(struct kref *kref)
108{
109 struct mtd_info *mtd = container_of(kref, struct mtd_info, refcnt);
110 bool is_partition = mtd_is_partition(mtd);
111
112 debugfs_remove_recursive(mtd->dbg.dfs_dir);
113
114 /* Try to remove the NVMEM provider */
115 nvmem_unregister(mtd->nvmem);
116
117 device_unregister(&mtd->dev);
118
119 /*
120 * Clear dev so mtd can be safely re-registered later if desired.
121 * Should not be done for partition,
122 * as it was already destroyed in device_unregister().
123 */
124 if (!is_partition)
125 memset(&mtd->dev, 0, sizeof(mtd->dev));
126
127 module_put(THIS_MODULE);
128}
129
130#define MTD_DEVICE_ATTR_RO(name) \
131static DEVICE_ATTR(name, 0444, mtd_##name##_show, NULL)
132
133#define MTD_DEVICE_ATTR_RW(name) \
134static DEVICE_ATTR(name, 0644, mtd_##name##_show, mtd_##name##_store)
135
136static ssize_t mtd_type_show(struct device *dev,
137 struct device_attribute *attr, char *buf)
138{
139 struct mtd_info *mtd = dev_get_drvdata(dev);
140 char *type;
141
142 switch (mtd->type) {
143 case MTD_ABSENT:
144 type = "absent";
145 break;
146 case MTD_RAM:
147 type = "ram";
148 break;
149 case MTD_ROM:
150 type = "rom";
151 break;
152 case MTD_NORFLASH:
153 type = "nor";
154 break;
155 case MTD_NANDFLASH:
156 type = "nand";
157 break;
158 case MTD_DATAFLASH:
159 type = "dataflash";
160 break;
161 case MTD_UBIVOLUME:
162 type = "ubi";
163 break;
164 case MTD_MLCNANDFLASH:
165 type = "mlc-nand";
166 break;
167 default:
168 type = "unknown";
169 }
170
171 return sysfs_emit(buf, "%s\n", type);
172}
173MTD_DEVICE_ATTR_RO(type);
174
175static ssize_t mtd_flags_show(struct device *dev,
176 struct device_attribute *attr, char *buf)
177{
178 struct mtd_info *mtd = dev_get_drvdata(dev);
179
180 return sysfs_emit(buf, "0x%lx\n", (unsigned long)mtd->flags);
181}
182MTD_DEVICE_ATTR_RO(flags);
183
184static ssize_t mtd_size_show(struct device *dev,
185 struct device_attribute *attr, char *buf)
186{
187 struct mtd_info *mtd = dev_get_drvdata(dev);
188
189 return sysfs_emit(buf, "%llu\n", (unsigned long long)mtd->size);
190}
191MTD_DEVICE_ATTR_RO(size);
192
193static ssize_t mtd_erasesize_show(struct device *dev,
194 struct device_attribute *attr, char *buf)
195{
196 struct mtd_info *mtd = dev_get_drvdata(dev);
197
198 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize);
199}
200MTD_DEVICE_ATTR_RO(erasesize);
201
202static ssize_t mtd_writesize_show(struct device *dev,
203 struct device_attribute *attr, char *buf)
204{
205 struct mtd_info *mtd = dev_get_drvdata(dev);
206
207 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->writesize);
208}
209MTD_DEVICE_ATTR_RO(writesize);
210
211static ssize_t mtd_subpagesize_show(struct device *dev,
212 struct device_attribute *attr, char *buf)
213{
214 struct mtd_info *mtd = dev_get_drvdata(dev);
215 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
216
217 return sysfs_emit(buf, "%u\n", subpagesize);
218}
219MTD_DEVICE_ATTR_RO(subpagesize);
220
221static ssize_t mtd_oobsize_show(struct device *dev,
222 struct device_attribute *attr, char *buf)
223{
224 struct mtd_info *mtd = dev_get_drvdata(dev);
225
226 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->oobsize);
227}
228MTD_DEVICE_ATTR_RO(oobsize);
229
230static ssize_t mtd_oobavail_show(struct device *dev,
231 struct device_attribute *attr, char *buf)
232{
233 struct mtd_info *mtd = dev_get_drvdata(dev);
234
235 return sysfs_emit(buf, "%u\n", mtd->oobavail);
236}
237MTD_DEVICE_ATTR_RO(oobavail);
238
239static ssize_t mtd_numeraseregions_show(struct device *dev,
240 struct device_attribute *attr, char *buf)
241{
242 struct mtd_info *mtd = dev_get_drvdata(dev);
243
244 return sysfs_emit(buf, "%u\n", mtd->numeraseregions);
245}
246MTD_DEVICE_ATTR_RO(numeraseregions);
247
248static ssize_t mtd_name_show(struct device *dev,
249 struct device_attribute *attr, char *buf)
250{
251 struct mtd_info *mtd = dev_get_drvdata(dev);
252
253 return sysfs_emit(buf, "%s\n", mtd->name);
254}
255MTD_DEVICE_ATTR_RO(name);
256
257static ssize_t mtd_ecc_strength_show(struct device *dev,
258 struct device_attribute *attr, char *buf)
259{
260 struct mtd_info *mtd = dev_get_drvdata(dev);
261
262 return sysfs_emit(buf, "%u\n", mtd->ecc_strength);
263}
264MTD_DEVICE_ATTR_RO(ecc_strength);
265
266static ssize_t mtd_bitflip_threshold_show(struct device *dev,
267 struct device_attribute *attr,
268 char *buf)
269{
270 struct mtd_info *mtd = dev_get_drvdata(dev);
271
272 return sysfs_emit(buf, "%u\n", mtd->bitflip_threshold);
273}
274
275static ssize_t mtd_bitflip_threshold_store(struct device *dev,
276 struct device_attribute *attr,
277 const char *buf, size_t count)
278{
279 struct mtd_info *mtd = dev_get_drvdata(dev);
280 unsigned int bitflip_threshold;
281 int retval;
282
283 retval = kstrtouint(buf, 0, &bitflip_threshold);
284 if (retval)
285 return retval;
286
287 mtd->bitflip_threshold = bitflip_threshold;
288 return count;
289}
290MTD_DEVICE_ATTR_RW(bitflip_threshold);
291
292static ssize_t mtd_ecc_step_size_show(struct device *dev,
293 struct device_attribute *attr, char *buf)
294{
295 struct mtd_info *mtd = dev_get_drvdata(dev);
296
297 return sysfs_emit(buf, "%u\n", mtd->ecc_step_size);
298
299}
300MTD_DEVICE_ATTR_RO(ecc_step_size);
301
302static ssize_t mtd_corrected_bits_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 sysfs_emit(buf, "%u\n", ecc_stats->corrected);
309}
310MTD_DEVICE_ATTR_RO(corrected_bits); /* ecc stats corrected */
311
312static ssize_t mtd_ecc_failures_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 sysfs_emit(buf, "%u\n", ecc_stats->failed);
319}
320MTD_DEVICE_ATTR_RO(ecc_failures); /* ecc stats errors */
321
322static ssize_t mtd_bad_blocks_show(struct device *dev,
323 struct device_attribute *attr, char *buf)
324{
325 struct mtd_info *mtd = dev_get_drvdata(dev);
326 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
327
328 return sysfs_emit(buf, "%u\n", ecc_stats->badblocks);
329}
330MTD_DEVICE_ATTR_RO(bad_blocks);
331
332static ssize_t mtd_bbt_blocks_show(struct device *dev,
333 struct device_attribute *attr, char *buf)
334{
335 struct mtd_info *mtd = dev_get_drvdata(dev);
336 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
337
338 return sysfs_emit(buf, "%u\n", ecc_stats->bbtblocks);
339}
340MTD_DEVICE_ATTR_RO(bbt_blocks);
341
342static struct attribute *mtd_attrs[] = {
343 &dev_attr_type.attr,
344 &dev_attr_flags.attr,
345 &dev_attr_size.attr,
346 &dev_attr_erasesize.attr,
347 &dev_attr_writesize.attr,
348 &dev_attr_subpagesize.attr,
349 &dev_attr_oobsize.attr,
350 &dev_attr_oobavail.attr,
351 &dev_attr_numeraseregions.attr,
352 &dev_attr_name.attr,
353 &dev_attr_ecc_strength.attr,
354 &dev_attr_ecc_step_size.attr,
355 &dev_attr_corrected_bits.attr,
356 &dev_attr_ecc_failures.attr,
357 &dev_attr_bad_blocks.attr,
358 &dev_attr_bbt_blocks.attr,
359 &dev_attr_bitflip_threshold.attr,
360 NULL,
361};
362ATTRIBUTE_GROUPS(mtd);
363
364static const struct device_type mtd_devtype = {
365 .name = "mtd",
366 .groups = mtd_groups,
367 .release = mtd_release,
368};
369
370static bool mtd_expert_analysis_mode;
371
372#ifdef CONFIG_DEBUG_FS
373bool mtd_check_expert_analysis_mode(void)
374{
375 const char *mtd_expert_analysis_warning =
376 "Bad block checks have been entirely disabled.\n"
377 "This is only reserved for post-mortem forensics and debug purposes.\n"
378 "Never enable this mode if you do not know what you are doing!\n";
379
380 return WARN_ONCE(mtd_expert_analysis_mode, mtd_expert_analysis_warning);
381}
382EXPORT_SYMBOL_GPL(mtd_check_expert_analysis_mode);
383#endif
384
385static struct dentry *dfs_dir_mtd;
386
387static void mtd_debugfs_populate(struct mtd_info *mtd)
388{
389 struct device *dev = &mtd->dev;
390
391 if (IS_ERR_OR_NULL(dfs_dir_mtd))
392 return;
393
394 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
395}
396
397#ifndef CONFIG_MMU
398unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
399{
400 switch (mtd->type) {
401 case MTD_RAM:
402 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
403 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
404 case MTD_ROM:
405 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
406 NOMMU_MAP_READ;
407 default:
408 return NOMMU_MAP_COPY;
409 }
410}
411EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
412#endif
413
414static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
415 void *cmd)
416{
417 struct mtd_info *mtd;
418
419 mtd = container_of(n, struct mtd_info, reboot_notifier);
420 mtd->_reboot(mtd);
421
422 return NOTIFY_DONE;
423}
424
425/**
426 * mtd_wunit_to_pairing_info - get pairing information of a wunit
427 * @mtd: pointer to new MTD device info structure
428 * @wunit: write unit we are interested in
429 * @info: returned pairing information
430 *
431 * Retrieve pairing information associated to the wunit.
432 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
433 * paired together, and where programming a page may influence the page it is
434 * paired with.
435 * The notion of page is replaced by the term wunit (write-unit) to stay
436 * consistent with the ->writesize field.
437 *
438 * The @wunit argument can be extracted from an absolute offset using
439 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
440 * to @wunit.
441 *
442 * From the pairing info the MTD user can find all the wunits paired with
443 * @wunit using the following loop:
444 *
445 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
446 * info.pair = i;
447 * mtd_pairing_info_to_wunit(mtd, &info);
448 * ...
449 * }
450 */
451int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
452 struct mtd_pairing_info *info)
453{
454 struct mtd_info *master = mtd_get_master(mtd);
455 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
456
457 if (wunit < 0 || wunit >= npairs)
458 return -EINVAL;
459
460 if (master->pairing && master->pairing->get_info)
461 return master->pairing->get_info(master, wunit, info);
462
463 info->group = 0;
464 info->pair = wunit;
465
466 return 0;
467}
468EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
469
470/**
471 * mtd_pairing_info_to_wunit - get wunit from pairing information
472 * @mtd: pointer to new MTD device info structure
473 * @info: pairing information struct
474 *
475 * Returns a positive number representing the wunit associated to the info
476 * struct, or a negative error code.
477 *
478 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
479 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
480 * doc).
481 *
482 * It can also be used to only program the first page of each pair (i.e.
483 * page attached to group 0), which allows one to use an MLC NAND in
484 * software-emulated SLC mode:
485 *
486 * info.group = 0;
487 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
488 * for (info.pair = 0; info.pair < npairs; info.pair++) {
489 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
490 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
491 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
492 * }
493 */
494int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
495 const struct mtd_pairing_info *info)
496{
497 struct mtd_info *master = mtd_get_master(mtd);
498 int ngroups = mtd_pairing_groups(master);
499 int npairs = mtd_wunit_per_eb(master) / ngroups;
500
501 if (!info || info->pair < 0 || info->pair >= npairs ||
502 info->group < 0 || info->group >= ngroups)
503 return -EINVAL;
504
505 if (master->pairing && master->pairing->get_wunit)
506 return mtd->pairing->get_wunit(master, info);
507
508 return info->pair;
509}
510EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
511
512/**
513 * mtd_pairing_groups - get the number of pairing groups
514 * @mtd: pointer to new MTD device info structure
515 *
516 * Returns the number of pairing groups.
517 *
518 * This number is usually equal to the number of bits exposed by a single
519 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
520 * to iterate over all pages of a given pair.
521 */
522int mtd_pairing_groups(struct mtd_info *mtd)
523{
524 struct mtd_info *master = mtd_get_master(mtd);
525
526 if (!master->pairing || !master->pairing->ngroups)
527 return 1;
528
529 return master->pairing->ngroups;
530}
531EXPORT_SYMBOL_GPL(mtd_pairing_groups);
532
533static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
534 void *val, size_t bytes)
535{
536 struct mtd_info *mtd = priv;
537 size_t retlen;
538 int err;
539
540 err = mtd_read(mtd, offset, bytes, &retlen, val);
541 if (err && err != -EUCLEAN)
542 return err;
543
544 return retlen == bytes ? 0 : -EIO;
545}
546
547static int mtd_nvmem_add(struct mtd_info *mtd)
548{
549 struct device_node *node = mtd_get_of_node(mtd);
550 struct nvmem_config config = {};
551
552 config.id = NVMEM_DEVID_NONE;
553 config.dev = &mtd->dev;
554 config.name = dev_name(&mtd->dev);
555 config.owner = THIS_MODULE;
556 config.add_legacy_fixed_of_cells = of_device_is_compatible(node, "nvmem-cells");
557 config.reg_read = mtd_nvmem_reg_read;
558 config.size = mtd->size;
559 config.word_size = 1;
560 config.stride = 1;
561 config.read_only = true;
562 config.root_only = true;
563 config.ignore_wp = true;
564 config.priv = mtd;
565
566 mtd->nvmem = nvmem_register(&config);
567 if (IS_ERR(mtd->nvmem)) {
568 /* Just ignore if there is no NVMEM support in the kernel */
569 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP)
570 mtd->nvmem = NULL;
571 else
572 return dev_err_probe(&mtd->dev, PTR_ERR(mtd->nvmem),
573 "Failed to register NVMEM device\n");
574 }
575
576 return 0;
577}
578
579static void mtd_check_of_node(struct mtd_info *mtd)
580{
581 struct device_node *partitions, *parent_dn, *mtd_dn = NULL;
582 const char *pname, *prefix = "partition-";
583 int plen, mtd_name_len, offset, prefix_len;
584
585 /* Check if MTD already has a device node */
586 if (mtd_get_of_node(mtd))
587 return;
588
589 if (!mtd_is_partition(mtd))
590 return;
591
592 parent_dn = of_node_get(mtd_get_of_node(mtd->parent));
593 if (!parent_dn)
594 return;
595
596 if (mtd_is_partition(mtd->parent))
597 partitions = of_node_get(parent_dn);
598 else
599 partitions = of_get_child_by_name(parent_dn, "partitions");
600 if (!partitions)
601 goto exit_parent;
602
603 prefix_len = strlen(prefix);
604 mtd_name_len = strlen(mtd->name);
605
606 /* Search if a partition is defined with the same name */
607 for_each_child_of_node(partitions, mtd_dn) {
608 /* Skip partition with no/wrong prefix */
609 if (!of_node_name_prefix(mtd_dn, prefix))
610 continue;
611
612 /* Label have priority. Check that first */
613 if (!of_property_read_string(mtd_dn, "label", &pname)) {
614 offset = 0;
615 } else {
616 pname = mtd_dn->name;
617 offset = prefix_len;
618 }
619
620 plen = strlen(pname) - offset;
621 if (plen == mtd_name_len &&
622 !strncmp(mtd->name, pname + offset, plen)) {
623 mtd_set_of_node(mtd, mtd_dn);
624 of_node_put(mtd_dn);
625 break;
626 }
627 }
628
629 of_node_put(partitions);
630exit_parent:
631 of_node_put(parent_dn);
632}
633
634/**
635 * add_mtd_device - register an MTD device
636 * @mtd: pointer to new MTD device info structure
637 *
638 * Add a device to the list of MTD devices present in the system, and
639 * notify each currently active MTD 'user' of its arrival. Returns
640 * zero on success or non-zero on failure.
641 */
642
643int add_mtd_device(struct mtd_info *mtd)
644{
645 struct device_node *np = mtd_get_of_node(mtd);
646 struct mtd_info *master = mtd_get_master(mtd);
647 struct mtd_notifier *not;
648 int i, error, ofidx;
649
650 /*
651 * May occur, for instance, on buggy drivers which call
652 * mtd_device_parse_register() multiple times on the same master MTD,
653 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
654 */
655 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
656 return -EEXIST;
657
658 BUG_ON(mtd->writesize == 0);
659
660 /*
661 * MTD drivers should implement ->_{write,read}() or
662 * ->_{write,read}_oob(), but not both.
663 */
664 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
665 (mtd->_read && mtd->_read_oob)))
666 return -EINVAL;
667
668 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
669 !(mtd->flags & MTD_NO_ERASE)))
670 return -EINVAL;
671
672 /*
673 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
674 * master is an MLC NAND and has a proper pairing scheme defined.
675 * We also reject masters that implement ->_writev() for now, because
676 * NAND controller drivers don't implement this hook, and adding the
677 * SLC -> MLC address/length conversion to this path is useless if we
678 * don't have a user.
679 */
680 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
681 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
682 !master->pairing || master->_writev))
683 return -EINVAL;
684
685 mutex_lock(&mtd_table_mutex);
686
687 ofidx = -1;
688 if (np)
689 ofidx = of_alias_get_id(np, "mtd");
690 if (ofidx >= 0)
691 i = idr_alloc(&mtd_idr, mtd, ofidx, ofidx + 1, GFP_KERNEL);
692 else
693 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
694 if (i < 0) {
695 error = i;
696 goto fail_locked;
697 }
698
699 mtd->index = i;
700 kref_init(&mtd->refcnt);
701
702 /* default value if not set by driver */
703 if (mtd->bitflip_threshold == 0)
704 mtd->bitflip_threshold = mtd->ecc_strength;
705
706 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
707 int ngroups = mtd_pairing_groups(master);
708
709 mtd->erasesize /= ngroups;
710 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
711 mtd->erasesize;
712 }
713
714 if (is_power_of_2(mtd->erasesize))
715 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
716 else
717 mtd->erasesize_shift = 0;
718
719 if (is_power_of_2(mtd->writesize))
720 mtd->writesize_shift = ffs(mtd->writesize) - 1;
721 else
722 mtd->writesize_shift = 0;
723
724 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
725 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
726
727 /* Some chips always power up locked. Unlock them now */
728 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
729 error = mtd_unlock(mtd, 0, mtd->size);
730 if (error && error != -EOPNOTSUPP)
731 printk(KERN_WARNING
732 "%s: unlock failed, writes may not work\n",
733 mtd->name);
734 /* Ignore unlock failures? */
735 error = 0;
736 }
737
738 /* Caller should have set dev.parent to match the
739 * physical device, if appropriate.
740 */
741 mtd->dev.type = &mtd_devtype;
742 mtd->dev.class = &mtd_class;
743 mtd->dev.devt = MTD_DEVT(i);
744 dev_set_name(&mtd->dev, "mtd%d", i);
745 dev_set_drvdata(&mtd->dev, mtd);
746 mtd_check_of_node(mtd);
747 of_node_get(mtd_get_of_node(mtd));
748 error = device_register(&mtd->dev);
749 if (error) {
750 put_device(&mtd->dev);
751 goto fail_added;
752 }
753
754 /* Add the nvmem provider */
755 error = mtd_nvmem_add(mtd);
756 if (error)
757 goto fail_nvmem_add;
758
759 mtd_debugfs_populate(mtd);
760
761 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
762 "mtd%dro", i);
763
764 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
765 /* No need to get a refcount on the module containing
766 the notifier, since we hold the mtd_table_mutex */
767 list_for_each_entry(not, &mtd_notifiers, list)
768 not->add(mtd);
769
770 mutex_unlock(&mtd_table_mutex);
771
772 if (of_property_read_bool(mtd_get_of_node(mtd), "linux,rootfs")) {
773 if (IS_BUILTIN(CONFIG_MTD)) {
774 pr_info("mtd: setting mtd%d (%s) as root device\n", mtd->index, mtd->name);
775 ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
776 } else {
777 pr_warn("mtd: can't set mtd%d (%s) as root device - mtd must be builtin\n",
778 mtd->index, mtd->name);
779 }
780 }
781
782 /* We _know_ we aren't being removed, because
783 our caller is still holding us here. So none
784 of this try_ nonsense, and no bitching about it
785 either. :) */
786 __module_get(THIS_MODULE);
787 return 0;
788
789fail_nvmem_add:
790 device_unregister(&mtd->dev);
791fail_added:
792 of_node_put(mtd_get_of_node(mtd));
793 idr_remove(&mtd_idr, i);
794fail_locked:
795 mutex_unlock(&mtd_table_mutex);
796 return error;
797}
798
799/**
800 * del_mtd_device - unregister an MTD device
801 * @mtd: pointer to MTD device info structure
802 *
803 * Remove a device from the list of MTD devices present in the system,
804 * and notify each currently active MTD 'user' of its departure.
805 * Returns zero on success or 1 on failure, which currently will happen
806 * if the requested device does not appear to be present in the list.
807 */
808
809int del_mtd_device(struct mtd_info *mtd)
810{
811 int ret;
812 struct mtd_notifier *not;
813
814 mutex_lock(&mtd_table_mutex);
815
816 if (idr_find(&mtd_idr, mtd->index) != mtd) {
817 ret = -ENODEV;
818 goto out_error;
819 }
820
821 /* No need to get a refcount on the module containing
822 the notifier, since we hold the mtd_table_mutex */
823 list_for_each_entry(not, &mtd_notifiers, list)
824 not->remove(mtd);
825
826 kref_put(&mtd->refcnt, mtd_device_release);
827 ret = 0;
828
829out_error:
830 mutex_unlock(&mtd_table_mutex);
831 return ret;
832}
833
834/*
835 * Set a few defaults based on the parent devices, if not provided by the
836 * driver
837 */
838static void mtd_set_dev_defaults(struct mtd_info *mtd)
839{
840 if (mtd->dev.parent) {
841 if (!mtd->owner && mtd->dev.parent->driver)
842 mtd->owner = mtd->dev.parent->driver->owner;
843 if (!mtd->name)
844 mtd->name = dev_name(mtd->dev.parent);
845 } else {
846 pr_debug("mtd device won't show a device symlink in sysfs\n");
847 }
848
849 INIT_LIST_HEAD(&mtd->partitions);
850 mutex_init(&mtd->master.partitions_lock);
851 mutex_init(&mtd->master.chrdev_lock);
852}
853
854static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
855{
856 struct otp_info *info;
857 ssize_t size = 0;
858 unsigned int i;
859 size_t retlen;
860 int ret;
861
862 info = kmalloc(PAGE_SIZE, GFP_KERNEL);
863 if (!info)
864 return -ENOMEM;
865
866 if (is_user)
867 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info);
868 else
869 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info);
870 if (ret)
871 goto err;
872
873 for (i = 0; i < retlen / sizeof(*info); i++)
874 size += info[i].length;
875
876 kfree(info);
877 return size;
878
879err:
880 kfree(info);
881
882 /* ENODATA means there is no OTP region. */
883 return ret == -ENODATA ? 0 : ret;
884}
885
886static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
887 const char *compatible,
888 int size,
889 nvmem_reg_read_t reg_read)
890{
891 struct nvmem_device *nvmem = NULL;
892 struct nvmem_config config = {};
893 struct device_node *np;
894
895 /* DT binding is optional */
896 np = of_get_compatible_child(mtd->dev.of_node, compatible);
897
898 /* OTP nvmem will be registered on the physical device */
899 config.dev = mtd->dev.parent;
900 config.name = compatible;
901 config.id = NVMEM_DEVID_AUTO;
902 config.owner = THIS_MODULE;
903 config.add_legacy_fixed_of_cells = !mtd_type_is_nand(mtd);
904 config.type = NVMEM_TYPE_OTP;
905 config.root_only = true;
906 config.ignore_wp = true;
907 config.reg_read = reg_read;
908 config.size = size;
909 config.of_node = np;
910 config.priv = mtd;
911
912 nvmem = nvmem_register(&config);
913 /* Just ignore if there is no NVMEM support in the kernel */
914 if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP)
915 nvmem = NULL;
916
917 of_node_put(np);
918
919 return nvmem;
920}
921
922static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
923 void *val, size_t bytes)
924{
925 struct mtd_info *mtd = priv;
926 size_t retlen;
927 int ret;
928
929 ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val);
930 if (ret)
931 return ret;
932
933 return retlen == bytes ? 0 : -EIO;
934}
935
936static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
937 void *val, size_t bytes)
938{
939 struct mtd_info *mtd = priv;
940 size_t retlen;
941 int ret;
942
943 ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val);
944 if (ret)
945 return ret;
946
947 return retlen == bytes ? 0 : -EIO;
948}
949
950static int mtd_otp_nvmem_add(struct mtd_info *mtd)
951{
952 struct device *dev = mtd->dev.parent;
953 struct nvmem_device *nvmem;
954 ssize_t size;
955 int err;
956
957 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
958 size = mtd_otp_size(mtd, true);
959 if (size < 0) {
960 err = size;
961 goto err;
962 }
963
964 if (size > 0) {
965 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
966 mtd_nvmem_user_otp_reg_read);
967 if (IS_ERR(nvmem)) {
968 err = PTR_ERR(nvmem);
969 goto err;
970 }
971 mtd->otp_user_nvmem = nvmem;
972 }
973 }
974
975 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
976 size = mtd_otp_size(mtd, false);
977 if (size < 0) {
978 err = size;
979 goto err;
980 }
981
982 if (size > 0) {
983 /*
984 * The factory OTP contains thing such as a unique serial
985 * number and is small, so let's read it out and put it
986 * into the entropy pool.
987 */
988 void *otp;
989
990 otp = kmalloc(size, GFP_KERNEL);
991 if (!otp) {
992 err = -ENOMEM;
993 goto err;
994 }
995 err = mtd_nvmem_fact_otp_reg_read(mtd, 0, otp, size);
996 if (err < 0) {
997 kfree(otp);
998 goto err;
999 }
1000 add_device_randomness(otp, err);
1001 kfree(otp);
1002
1003 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
1004 mtd_nvmem_fact_otp_reg_read);
1005 if (IS_ERR(nvmem)) {
1006 err = PTR_ERR(nvmem);
1007 goto err;
1008 }
1009 mtd->otp_factory_nvmem = nvmem;
1010 }
1011 }
1012
1013 return 0;
1014
1015err:
1016 nvmem_unregister(mtd->otp_user_nvmem);
1017 /* Don't report error if OTP is not supported. */
1018 if (err == -EOPNOTSUPP)
1019 return 0;
1020 return dev_err_probe(dev, err, "Failed to register OTP NVMEM device\n");
1021}
1022
1023/**
1024 * mtd_device_parse_register - parse partitions and register an MTD device.
1025 *
1026 * @mtd: the MTD device to register
1027 * @types: the list of MTD partition probes to try, see
1028 * 'parse_mtd_partitions()' for more information
1029 * @parser_data: MTD partition parser-specific data
1030 * @parts: fallback partition information to register, if parsing fails;
1031 * only valid if %nr_parts > %0
1032 * @nr_parts: the number of partitions in parts, if zero then the full
1033 * MTD device is registered if no partition info is found
1034 *
1035 * This function aggregates MTD partitions parsing (done by
1036 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
1037 * basically follows the most common pattern found in many MTD drivers:
1038 *
1039 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
1040 * registered first.
1041 * * Then It tries to probe partitions on MTD device @mtd using parsers
1042 * specified in @types (if @types is %NULL, then the default list of parsers
1043 * is used, see 'parse_mtd_partitions()' for more information). If none are
1044 * found this functions tries to fallback to information specified in
1045 * @parts/@nr_parts.
1046 * * If no partitions were found this function just registers the MTD device
1047 * @mtd and exits.
1048 *
1049 * Returns zero in case of success and a negative error code in case of failure.
1050 */
1051int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
1052 struct mtd_part_parser_data *parser_data,
1053 const struct mtd_partition *parts,
1054 int nr_parts)
1055{
1056 int ret;
1057
1058 mtd_set_dev_defaults(mtd);
1059
1060 ret = mtd_otp_nvmem_add(mtd);
1061 if (ret)
1062 goto out;
1063
1064 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
1065 ret = add_mtd_device(mtd);
1066 if (ret)
1067 goto out;
1068 }
1069
1070 /* Prefer parsed partitions over driver-provided fallback */
1071 ret = parse_mtd_partitions(mtd, types, parser_data);
1072 if (ret == -EPROBE_DEFER)
1073 goto out;
1074
1075 if (ret > 0)
1076 ret = 0;
1077 else if (nr_parts)
1078 ret = add_mtd_partitions(mtd, parts, nr_parts);
1079 else if (!device_is_registered(&mtd->dev))
1080 ret = add_mtd_device(mtd);
1081 else
1082 ret = 0;
1083
1084 if (ret)
1085 goto out;
1086
1087 /*
1088 * FIXME: some drivers unfortunately call this function more than once.
1089 * So we have to check if we've already assigned the reboot notifier.
1090 *
1091 * Generally, we can make multiple calls work for most cases, but it
1092 * does cause problems with parse_mtd_partitions() above (e.g.,
1093 * cmdlineparts will register partitions more than once).
1094 */
1095 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
1096 "MTD already registered\n");
1097 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
1098 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
1099 register_reboot_notifier(&mtd->reboot_notifier);
1100 }
1101
1102out:
1103 if (ret) {
1104 nvmem_unregister(mtd->otp_user_nvmem);
1105 nvmem_unregister(mtd->otp_factory_nvmem);
1106 }
1107
1108 if (ret && device_is_registered(&mtd->dev))
1109 del_mtd_device(mtd);
1110
1111 return ret;
1112}
1113EXPORT_SYMBOL_GPL(mtd_device_parse_register);
1114
1115/**
1116 * mtd_device_unregister - unregister an existing MTD device.
1117 *
1118 * @master: the MTD device to unregister. This will unregister both the master
1119 * and any partitions if registered.
1120 */
1121int mtd_device_unregister(struct mtd_info *master)
1122{
1123 int err;
1124
1125 if (master->_reboot) {
1126 unregister_reboot_notifier(&master->reboot_notifier);
1127 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
1128 }
1129
1130 nvmem_unregister(master->otp_user_nvmem);
1131 nvmem_unregister(master->otp_factory_nvmem);
1132
1133 err = del_mtd_partitions(master);
1134 if (err)
1135 return err;
1136
1137 if (!device_is_registered(&master->dev))
1138 return 0;
1139
1140 return del_mtd_device(master);
1141}
1142EXPORT_SYMBOL_GPL(mtd_device_unregister);
1143
1144/**
1145 * register_mtd_user - register a 'user' of MTD devices.
1146 * @new: pointer to notifier info structure
1147 *
1148 * Registers a pair of callbacks function to be called upon addition
1149 * or removal of MTD devices. Causes the 'add' callback to be immediately
1150 * invoked for each MTD device currently present in the system.
1151 */
1152void register_mtd_user (struct mtd_notifier *new)
1153{
1154 struct mtd_info *mtd;
1155
1156 mutex_lock(&mtd_table_mutex);
1157
1158 list_add(&new->list, &mtd_notifiers);
1159
1160 __module_get(THIS_MODULE);
1161
1162 mtd_for_each_device(mtd)
1163 new->add(mtd);
1164
1165 mutex_unlock(&mtd_table_mutex);
1166}
1167EXPORT_SYMBOL_GPL(register_mtd_user);
1168
1169/**
1170 * unregister_mtd_user - unregister a 'user' of MTD devices.
1171 * @old: pointer to notifier info structure
1172 *
1173 * Removes a callback function pair from the list of 'users' to be
1174 * notified upon addition or removal of MTD devices. Causes the
1175 * 'remove' callback to be immediately invoked for each MTD device
1176 * currently present in the system.
1177 */
1178int unregister_mtd_user (struct mtd_notifier *old)
1179{
1180 struct mtd_info *mtd;
1181
1182 mutex_lock(&mtd_table_mutex);
1183
1184 module_put(THIS_MODULE);
1185
1186 mtd_for_each_device(mtd)
1187 old->remove(mtd);
1188
1189 list_del(&old->list);
1190 mutex_unlock(&mtd_table_mutex);
1191 return 0;
1192}
1193EXPORT_SYMBOL_GPL(unregister_mtd_user);
1194
1195/**
1196 * get_mtd_device - obtain a validated handle for an MTD device
1197 * @mtd: last known address of the required MTD device
1198 * @num: internal device number of the required MTD device
1199 *
1200 * Given a number and NULL address, return the num'th entry in the device
1201 * table, if any. Given an address and num == -1, search the device table
1202 * for a device with that address and return if it's still present. Given
1203 * both, return the num'th driver only if its address matches. Return
1204 * error code if not.
1205 */
1206struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
1207{
1208 struct mtd_info *ret = NULL, *other;
1209 int err = -ENODEV;
1210
1211 mutex_lock(&mtd_table_mutex);
1212
1213 if (num == -1) {
1214 mtd_for_each_device(other) {
1215 if (other == mtd) {
1216 ret = mtd;
1217 break;
1218 }
1219 }
1220 } else if (num >= 0) {
1221 ret = idr_find(&mtd_idr, num);
1222 if (mtd && mtd != ret)
1223 ret = NULL;
1224 }
1225
1226 if (!ret) {
1227 ret = ERR_PTR(err);
1228 goto out;
1229 }
1230
1231 err = __get_mtd_device(ret);
1232 if (err)
1233 ret = ERR_PTR(err);
1234out:
1235 mutex_unlock(&mtd_table_mutex);
1236 return ret;
1237}
1238EXPORT_SYMBOL_GPL(get_mtd_device);
1239
1240
1241int __get_mtd_device(struct mtd_info *mtd)
1242{
1243 struct mtd_info *master = mtd_get_master(mtd);
1244 int err;
1245
1246 if (master->_get_device) {
1247 err = master->_get_device(mtd);
1248 if (err)
1249 return err;
1250 }
1251
1252 if (!try_module_get(master->owner)) {
1253 if (master->_put_device)
1254 master->_put_device(master);
1255 return -ENODEV;
1256 }
1257
1258 while (mtd) {
1259 if (mtd != master)
1260 kref_get(&mtd->refcnt);
1261 mtd = mtd->parent;
1262 }
1263
1264 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1265 kref_get(&master->refcnt);
1266
1267 return 0;
1268}
1269EXPORT_SYMBOL_GPL(__get_mtd_device);
1270
1271/**
1272 * of_get_mtd_device_by_node - obtain an MTD device associated with a given node
1273 *
1274 * @np: device tree node
1275 */
1276struct mtd_info *of_get_mtd_device_by_node(struct device_node *np)
1277{
1278 struct mtd_info *mtd = NULL;
1279 struct mtd_info *tmp;
1280 int err;
1281
1282 mutex_lock(&mtd_table_mutex);
1283
1284 err = -EPROBE_DEFER;
1285 mtd_for_each_device(tmp) {
1286 if (mtd_get_of_node(tmp) == np) {
1287 mtd = tmp;
1288 err = __get_mtd_device(mtd);
1289 break;
1290 }
1291 }
1292
1293 mutex_unlock(&mtd_table_mutex);
1294
1295 return err ? ERR_PTR(err) : mtd;
1296}
1297EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node);
1298
1299/**
1300 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1301 * device name
1302 * @name: MTD device name to open
1303 *
1304 * This function returns MTD device description structure in case of
1305 * success and an error code in case of failure.
1306 */
1307struct mtd_info *get_mtd_device_nm(const char *name)
1308{
1309 int err = -ENODEV;
1310 struct mtd_info *mtd = NULL, *other;
1311
1312 mutex_lock(&mtd_table_mutex);
1313
1314 mtd_for_each_device(other) {
1315 if (!strcmp(name, other->name)) {
1316 mtd = other;
1317 break;
1318 }
1319 }
1320
1321 if (!mtd)
1322 goto out_unlock;
1323
1324 err = __get_mtd_device(mtd);
1325 if (err)
1326 goto out_unlock;
1327
1328 mutex_unlock(&mtd_table_mutex);
1329 return mtd;
1330
1331out_unlock:
1332 mutex_unlock(&mtd_table_mutex);
1333 return ERR_PTR(err);
1334}
1335EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1336
1337void put_mtd_device(struct mtd_info *mtd)
1338{
1339 mutex_lock(&mtd_table_mutex);
1340 __put_mtd_device(mtd);
1341 mutex_unlock(&mtd_table_mutex);
1342
1343}
1344EXPORT_SYMBOL_GPL(put_mtd_device);
1345
1346void __put_mtd_device(struct mtd_info *mtd)
1347{
1348 struct mtd_info *master = mtd_get_master(mtd);
1349
1350 while (mtd) {
1351 /* kref_put() can relese mtd, so keep a reference mtd->parent */
1352 struct mtd_info *parent = mtd->parent;
1353
1354 if (mtd != master)
1355 kref_put(&mtd->refcnt, mtd_device_release);
1356 mtd = parent;
1357 }
1358
1359 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1360 kref_put(&master->refcnt, mtd_device_release);
1361
1362 module_put(master->owner);
1363
1364 /* must be the last as master can be freed in the _put_device */
1365 if (master->_put_device)
1366 master->_put_device(master);
1367}
1368EXPORT_SYMBOL_GPL(__put_mtd_device);
1369
1370/*
1371 * Erase is an synchronous operation. Device drivers are epected to return a
1372 * negative error code if the operation failed and update instr->fail_addr
1373 * to point the portion that was not properly erased.
1374 */
1375int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1376{
1377 struct mtd_info *master = mtd_get_master(mtd);
1378 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1379 struct erase_info adjinstr;
1380 int ret;
1381
1382 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1383 adjinstr = *instr;
1384
1385 if (!mtd->erasesize || !master->_erase)
1386 return -ENOTSUPP;
1387
1388 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1389 return -EINVAL;
1390 if (!(mtd->flags & MTD_WRITEABLE))
1391 return -EROFS;
1392
1393 if (!instr->len)
1394 return 0;
1395
1396 ledtrig_mtd_activity();
1397
1398 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1399 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1400 master->erasesize;
1401 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1402 master->erasesize) -
1403 adjinstr.addr;
1404 }
1405
1406 adjinstr.addr += mst_ofs;
1407
1408 ret = master->_erase(master, &adjinstr);
1409
1410 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1411 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1412 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1413 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1414 master);
1415 instr->fail_addr *= mtd->erasesize;
1416 }
1417 }
1418
1419 return ret;
1420}
1421EXPORT_SYMBOL_GPL(mtd_erase);
1422ALLOW_ERROR_INJECTION(mtd_erase, ERRNO);
1423
1424/*
1425 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1426 */
1427int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1428 void **virt, resource_size_t *phys)
1429{
1430 struct mtd_info *master = mtd_get_master(mtd);
1431
1432 *retlen = 0;
1433 *virt = NULL;
1434 if (phys)
1435 *phys = 0;
1436 if (!master->_point)
1437 return -EOPNOTSUPP;
1438 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1439 return -EINVAL;
1440 if (!len)
1441 return 0;
1442
1443 from = mtd_get_master_ofs(mtd, from);
1444 return master->_point(master, from, len, retlen, virt, phys);
1445}
1446EXPORT_SYMBOL_GPL(mtd_point);
1447
1448/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1449int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1450{
1451 struct mtd_info *master = mtd_get_master(mtd);
1452
1453 if (!master->_unpoint)
1454 return -EOPNOTSUPP;
1455 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1456 return -EINVAL;
1457 if (!len)
1458 return 0;
1459 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1460}
1461EXPORT_SYMBOL_GPL(mtd_unpoint);
1462
1463/*
1464 * Allow NOMMU mmap() to directly map the device (if not NULL)
1465 * - return the address to which the offset maps
1466 * - return -ENOSYS to indicate refusal to do the mapping
1467 */
1468unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1469 unsigned long offset, unsigned long flags)
1470{
1471 size_t retlen;
1472 void *virt;
1473 int ret;
1474
1475 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1476 if (ret)
1477 return ret;
1478 if (retlen != len) {
1479 mtd_unpoint(mtd, offset, retlen);
1480 return -ENOSYS;
1481 }
1482 return (unsigned long)virt;
1483}
1484EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1485
1486static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1487 const struct mtd_ecc_stats *old_stats)
1488{
1489 struct mtd_ecc_stats diff;
1490
1491 if (master == mtd)
1492 return;
1493
1494 diff = master->ecc_stats;
1495 diff.failed -= old_stats->failed;
1496 diff.corrected -= old_stats->corrected;
1497
1498 while (mtd->parent) {
1499 mtd->ecc_stats.failed += diff.failed;
1500 mtd->ecc_stats.corrected += diff.corrected;
1501 mtd = mtd->parent;
1502 }
1503}
1504
1505int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1506 u_char *buf)
1507{
1508 struct mtd_oob_ops ops = {
1509 .len = len,
1510 .datbuf = buf,
1511 };
1512 int ret;
1513
1514 ret = mtd_read_oob(mtd, from, &ops);
1515 *retlen = ops.retlen;
1516
1517 WARN_ON_ONCE(*retlen != len && mtd_is_bitflip_or_eccerr(ret));
1518
1519 return ret;
1520}
1521EXPORT_SYMBOL_GPL(mtd_read);
1522ALLOW_ERROR_INJECTION(mtd_read, ERRNO);
1523
1524int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1525 const u_char *buf)
1526{
1527 struct mtd_oob_ops ops = {
1528 .len = len,
1529 .datbuf = (u8 *)buf,
1530 };
1531 int ret;
1532
1533 ret = mtd_write_oob(mtd, to, &ops);
1534 *retlen = ops.retlen;
1535
1536 return ret;
1537}
1538EXPORT_SYMBOL_GPL(mtd_write);
1539ALLOW_ERROR_INJECTION(mtd_write, ERRNO);
1540
1541/*
1542 * In blackbox flight recorder like scenarios we want to make successful writes
1543 * in interrupt context. panic_write() is only intended to be called when its
1544 * known the kernel is about to panic and we need the write to succeed. Since
1545 * the kernel is not going to be running for much longer, this function can
1546 * break locks and delay to ensure the write succeeds (but not sleep).
1547 */
1548int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1549 const u_char *buf)
1550{
1551 struct mtd_info *master = mtd_get_master(mtd);
1552
1553 *retlen = 0;
1554 if (!master->_panic_write)
1555 return -EOPNOTSUPP;
1556 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1557 return -EINVAL;
1558 if (!(mtd->flags & MTD_WRITEABLE))
1559 return -EROFS;
1560 if (!len)
1561 return 0;
1562 if (!master->oops_panic_write)
1563 master->oops_panic_write = true;
1564
1565 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1566 retlen, buf);
1567}
1568EXPORT_SYMBOL_GPL(mtd_panic_write);
1569
1570static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1571 struct mtd_oob_ops *ops)
1572{
1573 /*
1574 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1575 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1576 * this case.
1577 */
1578 if (!ops->datbuf)
1579 ops->len = 0;
1580
1581 if (!ops->oobbuf)
1582 ops->ooblen = 0;
1583
1584 if (offs < 0 || offs + ops->len > mtd->size)
1585 return -EINVAL;
1586
1587 if (ops->ooblen) {
1588 size_t maxooblen;
1589
1590 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1591 return -EINVAL;
1592
1593 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1594 mtd_div_by_ws(offs, mtd)) *
1595 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1596 if (ops->ooblen > maxooblen)
1597 return -EINVAL;
1598 }
1599
1600 return 0;
1601}
1602
1603static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1604 struct mtd_oob_ops *ops)
1605{
1606 struct mtd_info *master = mtd_get_master(mtd);
1607 int ret;
1608
1609 from = mtd_get_master_ofs(mtd, from);
1610 if (master->_read_oob)
1611 ret = master->_read_oob(master, from, ops);
1612 else
1613 ret = master->_read(master, from, ops->len, &ops->retlen,
1614 ops->datbuf);
1615
1616 return ret;
1617}
1618
1619static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1620 struct mtd_oob_ops *ops)
1621{
1622 struct mtd_info *master = mtd_get_master(mtd);
1623 int ret;
1624
1625 to = mtd_get_master_ofs(mtd, to);
1626 if (master->_write_oob)
1627 ret = master->_write_oob(master, to, ops);
1628 else
1629 ret = master->_write(master, to, ops->len, &ops->retlen,
1630 ops->datbuf);
1631
1632 return ret;
1633}
1634
1635static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1636 struct mtd_oob_ops *ops)
1637{
1638 struct mtd_info *master = mtd_get_master(mtd);
1639 int ngroups = mtd_pairing_groups(master);
1640 int npairs = mtd_wunit_per_eb(master) / ngroups;
1641 struct mtd_oob_ops adjops = *ops;
1642 unsigned int wunit, oobavail;
1643 struct mtd_pairing_info info;
1644 int max_bitflips = 0;
1645 u32 ebofs, pageofs;
1646 loff_t base, pos;
1647
1648 ebofs = mtd_mod_by_eb(start, mtd);
1649 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1650 info.group = 0;
1651 info.pair = mtd_div_by_ws(ebofs, mtd);
1652 pageofs = mtd_mod_by_ws(ebofs, mtd);
1653 oobavail = mtd_oobavail(mtd, ops);
1654
1655 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1656 int ret;
1657
1658 if (info.pair >= npairs) {
1659 info.pair = 0;
1660 base += master->erasesize;
1661 }
1662
1663 wunit = mtd_pairing_info_to_wunit(master, &info);
1664 pos = mtd_wunit_to_offset(mtd, base, wunit);
1665
1666 adjops.len = ops->len - ops->retlen;
1667 if (adjops.len > mtd->writesize - pageofs)
1668 adjops.len = mtd->writesize - pageofs;
1669
1670 adjops.ooblen = ops->ooblen - ops->oobretlen;
1671 if (adjops.ooblen > oobavail - adjops.ooboffs)
1672 adjops.ooblen = oobavail - adjops.ooboffs;
1673
1674 if (read) {
1675 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1676 if (ret > 0)
1677 max_bitflips = max(max_bitflips, ret);
1678 } else {
1679 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1680 }
1681
1682 if (ret < 0)
1683 return ret;
1684
1685 max_bitflips = max(max_bitflips, ret);
1686 ops->retlen += adjops.retlen;
1687 ops->oobretlen += adjops.oobretlen;
1688 adjops.datbuf += adjops.retlen;
1689 adjops.oobbuf += adjops.oobretlen;
1690 adjops.ooboffs = 0;
1691 pageofs = 0;
1692 info.pair++;
1693 }
1694
1695 return max_bitflips;
1696}
1697
1698int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1699{
1700 struct mtd_info *master = mtd_get_master(mtd);
1701 struct mtd_ecc_stats old_stats = master->ecc_stats;
1702 int ret_code;
1703
1704 ops->retlen = ops->oobretlen = 0;
1705
1706 ret_code = mtd_check_oob_ops(mtd, from, ops);
1707 if (ret_code)
1708 return ret_code;
1709
1710 ledtrig_mtd_activity();
1711
1712 /* Check the validity of a potential fallback on mtd->_read */
1713 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1714 return -EOPNOTSUPP;
1715
1716 if (ops->stats)
1717 memset(ops->stats, 0, sizeof(*ops->stats));
1718
1719 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1720 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1721 else
1722 ret_code = mtd_read_oob_std(mtd, from, ops);
1723
1724 mtd_update_ecc_stats(mtd, master, &old_stats);
1725
1726 /*
1727 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1728 * similar to mtd->_read(), returning a non-negative integer
1729 * representing max bitflips. In other cases, mtd->_read_oob() may
1730 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1731 */
1732 if (unlikely(ret_code < 0))
1733 return ret_code;
1734 if (mtd->ecc_strength == 0)
1735 return 0; /* device lacks ecc */
1736 if (ops->stats)
1737 ops->stats->max_bitflips = ret_code;
1738 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1739}
1740EXPORT_SYMBOL_GPL(mtd_read_oob);
1741
1742int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1743 struct mtd_oob_ops *ops)
1744{
1745 struct mtd_info *master = mtd_get_master(mtd);
1746 int ret;
1747
1748 ops->retlen = ops->oobretlen = 0;
1749
1750 if (!(mtd->flags & MTD_WRITEABLE))
1751 return -EROFS;
1752
1753 ret = mtd_check_oob_ops(mtd, to, ops);
1754 if (ret)
1755 return ret;
1756
1757 ledtrig_mtd_activity();
1758
1759 /* Check the validity of a potential fallback on mtd->_write */
1760 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1761 return -EOPNOTSUPP;
1762
1763 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1764 return mtd_io_emulated_slc(mtd, to, false, ops);
1765
1766 return mtd_write_oob_std(mtd, to, ops);
1767}
1768EXPORT_SYMBOL_GPL(mtd_write_oob);
1769
1770/**
1771 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1772 * @mtd: MTD device structure
1773 * @section: ECC section. Depending on the layout you may have all the ECC
1774 * bytes stored in a single contiguous section, or one section
1775 * per ECC chunk (and sometime several sections for a single ECC
1776 * ECC chunk)
1777 * @oobecc: OOB region struct filled with the appropriate ECC position
1778 * information
1779 *
1780 * This function returns ECC section information in the OOB area. If you want
1781 * to get all the ECC bytes information, then you should call
1782 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1783 *
1784 * Returns zero on success, a negative error code otherwise.
1785 */
1786int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1787 struct mtd_oob_region *oobecc)
1788{
1789 struct mtd_info *master = mtd_get_master(mtd);
1790
1791 memset(oobecc, 0, sizeof(*oobecc));
1792
1793 if (!master || section < 0)
1794 return -EINVAL;
1795
1796 if (!master->ooblayout || !master->ooblayout->ecc)
1797 return -ENOTSUPP;
1798
1799 return master->ooblayout->ecc(master, section, oobecc);
1800}
1801EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1802
1803/**
1804 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1805 * section
1806 * @mtd: MTD device structure
1807 * @section: Free section you are interested in. Depending on the layout
1808 * you may have all the free bytes stored in a single contiguous
1809 * section, or one section per ECC chunk plus an extra section
1810 * for the remaining bytes (or other funky layout).
1811 * @oobfree: OOB region struct filled with the appropriate free position
1812 * information
1813 *
1814 * This function returns free bytes position in the OOB area. If you want
1815 * to get all the free bytes information, then you should call
1816 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1817 *
1818 * Returns zero on success, a negative error code otherwise.
1819 */
1820int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1821 struct mtd_oob_region *oobfree)
1822{
1823 struct mtd_info *master = mtd_get_master(mtd);
1824
1825 memset(oobfree, 0, sizeof(*oobfree));
1826
1827 if (!master || section < 0)
1828 return -EINVAL;
1829
1830 if (!master->ooblayout || !master->ooblayout->free)
1831 return -ENOTSUPP;
1832
1833 return master->ooblayout->free(master, section, oobfree);
1834}
1835EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1836
1837/**
1838 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1839 * @mtd: mtd info structure
1840 * @byte: the byte we are searching for
1841 * @sectionp: pointer where the section id will be stored
1842 * @oobregion: used to retrieve the ECC position
1843 * @iter: iterator function. Should be either mtd_ooblayout_free or
1844 * mtd_ooblayout_ecc depending on the region type you're searching for
1845 *
1846 * This function returns the section id and oobregion information of a
1847 * specific byte. For example, say you want to know where the 4th ECC byte is
1848 * stored, you'll use:
1849 *
1850 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1851 *
1852 * Returns zero on success, a negative error code otherwise.
1853 */
1854static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1855 int *sectionp, struct mtd_oob_region *oobregion,
1856 int (*iter)(struct mtd_info *,
1857 int section,
1858 struct mtd_oob_region *oobregion))
1859{
1860 int pos = 0, ret, section = 0;
1861
1862 memset(oobregion, 0, sizeof(*oobregion));
1863
1864 while (1) {
1865 ret = iter(mtd, section, oobregion);
1866 if (ret)
1867 return ret;
1868
1869 if (pos + oobregion->length > byte)
1870 break;
1871
1872 pos += oobregion->length;
1873 section++;
1874 }
1875
1876 /*
1877 * Adjust region info to make it start at the beginning at the
1878 * 'start' ECC byte.
1879 */
1880 oobregion->offset += byte - pos;
1881 oobregion->length -= byte - pos;
1882 *sectionp = section;
1883
1884 return 0;
1885}
1886
1887/**
1888 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1889 * ECC byte
1890 * @mtd: mtd info structure
1891 * @eccbyte: the byte we are searching for
1892 * @section: pointer where the section id will be stored
1893 * @oobregion: OOB region information
1894 *
1895 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1896 * byte.
1897 *
1898 * Returns zero on success, a negative error code otherwise.
1899 */
1900int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1901 int *section,
1902 struct mtd_oob_region *oobregion)
1903{
1904 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1905 mtd_ooblayout_ecc);
1906}
1907EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1908
1909/**
1910 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1911 * @mtd: mtd info structure
1912 * @buf: destination buffer to store OOB bytes
1913 * @oobbuf: OOB buffer
1914 * @start: first byte to retrieve
1915 * @nbytes: number of bytes to retrieve
1916 * @iter: section iterator
1917 *
1918 * Extract bytes attached to a specific category (ECC or free)
1919 * from the OOB buffer and copy them into buf.
1920 *
1921 * Returns zero on success, a negative error code otherwise.
1922 */
1923static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1924 const u8 *oobbuf, int start, int nbytes,
1925 int (*iter)(struct mtd_info *,
1926 int section,
1927 struct mtd_oob_region *oobregion))
1928{
1929 struct mtd_oob_region oobregion;
1930 int section, ret;
1931
1932 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1933 &oobregion, iter);
1934
1935 while (!ret) {
1936 int cnt;
1937
1938 cnt = min_t(int, nbytes, oobregion.length);
1939 memcpy(buf, oobbuf + oobregion.offset, cnt);
1940 buf += cnt;
1941 nbytes -= cnt;
1942
1943 if (!nbytes)
1944 break;
1945
1946 ret = iter(mtd, ++section, &oobregion);
1947 }
1948
1949 return ret;
1950}
1951
1952/**
1953 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1954 * @mtd: mtd info structure
1955 * @buf: source buffer to get OOB bytes from
1956 * @oobbuf: OOB buffer
1957 * @start: first OOB byte to set
1958 * @nbytes: number of OOB bytes to set
1959 * @iter: section iterator
1960 *
1961 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1962 * is selected by passing the appropriate iterator.
1963 *
1964 * Returns zero on success, a negative error code otherwise.
1965 */
1966static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1967 u8 *oobbuf, int start, int nbytes,
1968 int (*iter)(struct mtd_info *,
1969 int section,
1970 struct mtd_oob_region *oobregion))
1971{
1972 struct mtd_oob_region oobregion;
1973 int section, ret;
1974
1975 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1976 &oobregion, iter);
1977
1978 while (!ret) {
1979 int cnt;
1980
1981 cnt = min_t(int, nbytes, oobregion.length);
1982 memcpy(oobbuf + oobregion.offset, buf, cnt);
1983 buf += cnt;
1984 nbytes -= cnt;
1985
1986 if (!nbytes)
1987 break;
1988
1989 ret = iter(mtd, ++section, &oobregion);
1990 }
1991
1992 return ret;
1993}
1994
1995/**
1996 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1997 * @mtd: mtd info structure
1998 * @iter: category iterator
1999 *
2000 * Count the number of bytes in a given category.
2001 *
2002 * Returns a positive value on success, a negative error code otherwise.
2003 */
2004static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
2005 int (*iter)(struct mtd_info *,
2006 int section,
2007 struct mtd_oob_region *oobregion))
2008{
2009 struct mtd_oob_region oobregion;
2010 int section = 0, ret, nbytes = 0;
2011
2012 while (1) {
2013 ret = iter(mtd, section++, &oobregion);
2014 if (ret) {
2015 if (ret == -ERANGE)
2016 ret = nbytes;
2017 break;
2018 }
2019
2020 nbytes += oobregion.length;
2021 }
2022
2023 return ret;
2024}
2025
2026/**
2027 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
2028 * @mtd: mtd info structure
2029 * @eccbuf: destination buffer to store ECC bytes
2030 * @oobbuf: OOB buffer
2031 * @start: first ECC byte to retrieve
2032 * @nbytes: number of ECC bytes to retrieve
2033 *
2034 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
2035 *
2036 * Returns zero on success, a negative error code otherwise.
2037 */
2038int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
2039 const u8 *oobbuf, int start, int nbytes)
2040{
2041 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
2042 mtd_ooblayout_ecc);
2043}
2044EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
2045
2046/**
2047 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
2048 * @mtd: mtd info structure
2049 * @eccbuf: source buffer to get ECC bytes from
2050 * @oobbuf: OOB buffer
2051 * @start: first ECC byte to set
2052 * @nbytes: number of ECC bytes to set
2053 *
2054 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
2055 *
2056 * Returns zero on success, a negative error code otherwise.
2057 */
2058int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
2059 u8 *oobbuf, int start, int nbytes)
2060{
2061 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
2062 mtd_ooblayout_ecc);
2063}
2064EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
2065
2066/**
2067 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
2068 * @mtd: mtd info structure
2069 * @databuf: destination buffer to store ECC bytes
2070 * @oobbuf: OOB buffer
2071 * @start: first ECC byte to retrieve
2072 * @nbytes: number of ECC bytes to retrieve
2073 *
2074 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
2075 *
2076 * Returns zero on success, a negative error code otherwise.
2077 */
2078int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
2079 const u8 *oobbuf, int start, int nbytes)
2080{
2081 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
2082 mtd_ooblayout_free);
2083}
2084EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
2085
2086/**
2087 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
2088 * @mtd: mtd info structure
2089 * @databuf: source buffer to get data bytes from
2090 * @oobbuf: OOB buffer
2091 * @start: first ECC byte to set
2092 * @nbytes: number of ECC bytes to set
2093 *
2094 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
2095 *
2096 * Returns zero on success, a negative error code otherwise.
2097 */
2098int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
2099 u8 *oobbuf, int start, int nbytes)
2100{
2101 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
2102 mtd_ooblayout_free);
2103}
2104EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
2105
2106/**
2107 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
2108 * @mtd: mtd info structure
2109 *
2110 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
2111 *
2112 * Returns zero on success, a negative error code otherwise.
2113 */
2114int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
2115{
2116 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
2117}
2118EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
2119
2120/**
2121 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
2122 * @mtd: mtd info structure
2123 *
2124 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
2125 *
2126 * Returns zero on success, a negative error code otherwise.
2127 */
2128int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
2129{
2130 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
2131}
2132EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
2133
2134/*
2135 * Method to access the protection register area, present in some flash
2136 * devices. The user data is one time programmable but the factory data is read
2137 * only.
2138 */
2139int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2140 struct otp_info *buf)
2141{
2142 struct mtd_info *master = mtd_get_master(mtd);
2143
2144 if (!master->_get_fact_prot_info)
2145 return -EOPNOTSUPP;
2146 if (!len)
2147 return 0;
2148 return master->_get_fact_prot_info(master, len, retlen, buf);
2149}
2150EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
2151
2152int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2153 size_t *retlen, u_char *buf)
2154{
2155 struct mtd_info *master = mtd_get_master(mtd);
2156
2157 *retlen = 0;
2158 if (!master->_read_fact_prot_reg)
2159 return -EOPNOTSUPP;
2160 if (!len)
2161 return 0;
2162 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
2163}
2164EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
2165
2166int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2167 struct otp_info *buf)
2168{
2169 struct mtd_info *master = mtd_get_master(mtd);
2170
2171 if (!master->_get_user_prot_info)
2172 return -EOPNOTSUPP;
2173 if (!len)
2174 return 0;
2175 return master->_get_user_prot_info(master, len, retlen, buf);
2176}
2177EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
2178
2179int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2180 size_t *retlen, u_char *buf)
2181{
2182 struct mtd_info *master = mtd_get_master(mtd);
2183
2184 *retlen = 0;
2185 if (!master->_read_user_prot_reg)
2186 return -EOPNOTSUPP;
2187 if (!len)
2188 return 0;
2189 return master->_read_user_prot_reg(master, from, len, retlen, buf);
2190}
2191EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
2192
2193int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
2194 size_t *retlen, const u_char *buf)
2195{
2196 struct mtd_info *master = mtd_get_master(mtd);
2197 int ret;
2198
2199 *retlen = 0;
2200 if (!master->_write_user_prot_reg)
2201 return -EOPNOTSUPP;
2202 if (!len)
2203 return 0;
2204 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
2205 if (ret)
2206 return ret;
2207
2208 /*
2209 * If no data could be written at all, we are out of memory and
2210 * must return -ENOSPC.
2211 */
2212 return (*retlen) ? 0 : -ENOSPC;
2213}
2214EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
2215
2216int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2217{
2218 struct mtd_info *master = mtd_get_master(mtd);
2219
2220 if (!master->_lock_user_prot_reg)
2221 return -EOPNOTSUPP;
2222 if (!len)
2223 return 0;
2224 return master->_lock_user_prot_reg(master, from, len);
2225}
2226EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
2227
2228int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2229{
2230 struct mtd_info *master = mtd_get_master(mtd);
2231
2232 if (!master->_erase_user_prot_reg)
2233 return -EOPNOTSUPP;
2234 if (!len)
2235 return 0;
2236 return master->_erase_user_prot_reg(master, from, len);
2237}
2238EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
2239
2240/* Chip-supported device locking */
2241int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2242{
2243 struct mtd_info *master = mtd_get_master(mtd);
2244
2245 if (!master->_lock)
2246 return -EOPNOTSUPP;
2247 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2248 return -EINVAL;
2249 if (!len)
2250 return 0;
2251
2252 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2253 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2254 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2255 }
2256
2257 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
2258}
2259EXPORT_SYMBOL_GPL(mtd_lock);
2260
2261int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2262{
2263 struct mtd_info *master = mtd_get_master(mtd);
2264
2265 if (!master->_unlock)
2266 return -EOPNOTSUPP;
2267 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2268 return -EINVAL;
2269 if (!len)
2270 return 0;
2271
2272 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2273 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2274 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2275 }
2276
2277 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
2278}
2279EXPORT_SYMBOL_GPL(mtd_unlock);
2280
2281int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2282{
2283 struct mtd_info *master = mtd_get_master(mtd);
2284
2285 if (!master->_is_locked)
2286 return -EOPNOTSUPP;
2287 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2288 return -EINVAL;
2289 if (!len)
2290 return 0;
2291
2292 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2293 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2294 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2295 }
2296
2297 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
2298}
2299EXPORT_SYMBOL_GPL(mtd_is_locked);
2300
2301int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2302{
2303 struct mtd_info *master = mtd_get_master(mtd);
2304
2305 if (ofs < 0 || ofs >= mtd->size)
2306 return -EINVAL;
2307 if (!master->_block_isreserved)
2308 return 0;
2309
2310 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2311 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2312
2313 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2314}
2315EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2316
2317int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2318{
2319 struct mtd_info *master = mtd_get_master(mtd);
2320
2321 if (ofs < 0 || ofs >= mtd->size)
2322 return -EINVAL;
2323 if (!master->_block_isbad)
2324 return 0;
2325
2326 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2327 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2328
2329 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2330}
2331EXPORT_SYMBOL_GPL(mtd_block_isbad);
2332
2333int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2334{
2335 struct mtd_info *master = mtd_get_master(mtd);
2336 int ret;
2337
2338 if (!master->_block_markbad)
2339 return -EOPNOTSUPP;
2340 if (ofs < 0 || ofs >= mtd->size)
2341 return -EINVAL;
2342 if (!(mtd->flags & MTD_WRITEABLE))
2343 return -EROFS;
2344
2345 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2346 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2347
2348 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2349 if (ret)
2350 return ret;
2351
2352 while (mtd->parent) {
2353 mtd->ecc_stats.badblocks++;
2354 mtd = mtd->parent;
2355 }
2356
2357 return 0;
2358}
2359EXPORT_SYMBOL_GPL(mtd_block_markbad);
2360ALLOW_ERROR_INJECTION(mtd_block_markbad, ERRNO);
2361
2362/*
2363 * default_mtd_writev - the default writev method
2364 * @mtd: mtd device description object pointer
2365 * @vecs: the vectors to write
2366 * @count: count of vectors in @vecs
2367 * @to: the MTD device offset to write to
2368 * @retlen: on exit contains the count of bytes written to the MTD device.
2369 *
2370 * This function returns zero in case of success and a negative error code in
2371 * case of failure.
2372 */
2373static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2374 unsigned long count, loff_t to, size_t *retlen)
2375{
2376 unsigned long i;
2377 size_t totlen = 0, thislen;
2378 int ret = 0;
2379
2380 for (i = 0; i < count; i++) {
2381 if (!vecs[i].iov_len)
2382 continue;
2383 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2384 vecs[i].iov_base);
2385 totlen += thislen;
2386 if (ret || thislen != vecs[i].iov_len)
2387 break;
2388 to += vecs[i].iov_len;
2389 }
2390 *retlen = totlen;
2391 return ret;
2392}
2393
2394/*
2395 * mtd_writev - the vector-based MTD write method
2396 * @mtd: mtd device description object pointer
2397 * @vecs: the vectors to write
2398 * @count: count of vectors in @vecs
2399 * @to: the MTD device offset to write to
2400 * @retlen: on exit contains the count of bytes written to the MTD device.
2401 *
2402 * This function returns zero in case of success and a negative error code in
2403 * case of failure.
2404 */
2405int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2406 unsigned long count, loff_t to, size_t *retlen)
2407{
2408 struct mtd_info *master = mtd_get_master(mtd);
2409
2410 *retlen = 0;
2411 if (!(mtd->flags & MTD_WRITEABLE))
2412 return -EROFS;
2413
2414 if (!master->_writev)
2415 return default_mtd_writev(mtd, vecs, count, to, retlen);
2416
2417 return master->_writev(master, vecs, count,
2418 mtd_get_master_ofs(mtd, to), retlen);
2419}
2420EXPORT_SYMBOL_GPL(mtd_writev);
2421
2422/**
2423 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2424 * @mtd: mtd device description object pointer
2425 * @size: a pointer to the ideal or maximum size of the allocation, points
2426 * to the actual allocation size on success.
2427 *
2428 * This routine attempts to allocate a contiguous kernel buffer up to
2429 * the specified size, backing off the size of the request exponentially
2430 * until the request succeeds or until the allocation size falls below
2431 * the system page size. This attempts to make sure it does not adversely
2432 * impact system performance, so when allocating more than one page, we
2433 * ask the memory allocator to avoid re-trying, swapping, writing back
2434 * or performing I/O.
2435 *
2436 * Note, this function also makes sure that the allocated buffer is aligned to
2437 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2438 *
2439 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2440 * to handle smaller (i.e. degraded) buffer allocations under low- or
2441 * fragmented-memory situations where such reduced allocations, from a
2442 * requested ideal, are allowed.
2443 *
2444 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2445 */
2446void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2447{
2448 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2449 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2450 void *kbuf;
2451
2452 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2453
2454 while (*size > min_alloc) {
2455 kbuf = kmalloc(*size, flags);
2456 if (kbuf)
2457 return kbuf;
2458
2459 *size >>= 1;
2460 *size = ALIGN(*size, mtd->writesize);
2461 }
2462
2463 /*
2464 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2465 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2466 */
2467 return kmalloc(*size, GFP_KERNEL);
2468}
2469EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2470
2471#ifdef CONFIG_PROC_FS
2472
2473/*====================================================================*/
2474/* Support for /proc/mtd */
2475
2476static int mtd_proc_show(struct seq_file *m, void *v)
2477{
2478 struct mtd_info *mtd;
2479
2480 seq_puts(m, "dev: size erasesize name\n");
2481 mutex_lock(&mtd_table_mutex);
2482 mtd_for_each_device(mtd) {
2483 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2484 mtd->index, (unsigned long long)mtd->size,
2485 mtd->erasesize, mtd->name);
2486 }
2487 mutex_unlock(&mtd_table_mutex);
2488 return 0;
2489}
2490#endif /* CONFIG_PROC_FS */
2491
2492/*====================================================================*/
2493/* Init code */
2494
2495static struct backing_dev_info * __init mtd_bdi_init(const char *name)
2496{
2497 struct backing_dev_info *bdi;
2498 int ret;
2499
2500 bdi = bdi_alloc(NUMA_NO_NODE);
2501 if (!bdi)
2502 return ERR_PTR(-ENOMEM);
2503 bdi->ra_pages = 0;
2504 bdi->io_pages = 0;
2505
2506 /*
2507 * We put '-0' suffix to the name to get the same name format as we
2508 * used to get. Since this is called only once, we get a unique name.
2509 */
2510 ret = bdi_register(bdi, "%.28s-0", name);
2511 if (ret)
2512 bdi_put(bdi);
2513
2514 return ret ? ERR_PTR(ret) : bdi;
2515}
2516
2517static struct proc_dir_entry *proc_mtd;
2518
2519static int __init init_mtd(void)
2520{
2521 int ret;
2522
2523 ret = class_register(&mtd_class);
2524 if (ret)
2525 goto err_reg;
2526
2527 mtd_bdi = mtd_bdi_init("mtd");
2528 if (IS_ERR(mtd_bdi)) {
2529 ret = PTR_ERR(mtd_bdi);
2530 goto err_bdi;
2531 }
2532
2533 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2534
2535 ret = init_mtdchar();
2536 if (ret)
2537 goto out_procfs;
2538
2539 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2540 debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd,
2541 &mtd_expert_analysis_mode);
2542
2543 return 0;
2544
2545out_procfs:
2546 if (proc_mtd)
2547 remove_proc_entry("mtd", NULL);
2548 bdi_unregister(mtd_bdi);
2549 bdi_put(mtd_bdi);
2550err_bdi:
2551 class_unregister(&mtd_class);
2552err_reg:
2553 pr_err("Error registering mtd class or bdi: %d\n", ret);
2554 return ret;
2555}
2556
2557static void __exit cleanup_mtd(void)
2558{
2559 debugfs_remove_recursive(dfs_dir_mtd);
2560 cleanup_mtdchar();
2561 if (proc_mtd)
2562 remove_proc_entry("mtd", NULL);
2563 class_unregister(&mtd_class);
2564 bdi_unregister(mtd_bdi);
2565 bdi_put(mtd_bdi);
2566 idr_destroy(&mtd_idr);
2567}
2568
2569module_init(init_mtd);
2570module_exit(cleanup_mtd);
2571
2572MODULE_LICENSE("GPL");
2573MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2574MODULE_DESCRIPTION("Core MTD registration and access routines");