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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/slab.h>
27#include <linux/reboot.h>
28#include <linux/leds.h>
29#include <linux/debugfs.h>
30#include <linux/nvmem-provider.h>
31
32#include <linux/mtd/mtd.h>
33#include <linux/mtd/partitions.h>
34
35#include "mtdcore.h"
36
37struct backing_dev_info *mtd_bdi;
38
39#ifdef CONFIG_PM_SLEEP
40
41static int mtd_cls_suspend(struct device *dev)
42{
43 struct mtd_info *mtd = dev_get_drvdata(dev);
44
45 return mtd ? mtd_suspend(mtd) : 0;
46}
47
48static int mtd_cls_resume(struct device *dev)
49{
50 struct mtd_info *mtd = dev_get_drvdata(dev);
51
52 if (mtd)
53 mtd_resume(mtd);
54 return 0;
55}
56
57static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
58#define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
59#else
60#define MTD_CLS_PM_OPS NULL
61#endif
62
63static struct class mtd_class = {
64 .name = "mtd",
65 .owner = THIS_MODULE,
66 .pm = MTD_CLS_PM_OPS,
67};
68
69static DEFINE_IDR(mtd_idr);
70
71/* These are exported solely for the purpose of mtd_blkdevs.c. You
72 should not use them for _anything_ else */
73DEFINE_MUTEX(mtd_table_mutex);
74EXPORT_SYMBOL_GPL(mtd_table_mutex);
75
76struct mtd_info *__mtd_next_device(int i)
77{
78 return idr_get_next(&mtd_idr, &i);
79}
80EXPORT_SYMBOL_GPL(__mtd_next_device);
81
82static LIST_HEAD(mtd_notifiers);
83
84
85#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
86
87/* REVISIT once MTD uses the driver model better, whoever allocates
88 * the mtd_info will probably want to use the release() hook...
89 */
90static void mtd_release(struct device *dev)
91{
92 struct mtd_info *mtd = dev_get_drvdata(dev);
93 dev_t index = MTD_DEVT(mtd->index);
94
95 /* remove /dev/mtdXro node */
96 device_destroy(&mtd_class, index + 1);
97}
98
99static ssize_t mtd_type_show(struct device *dev,
100 struct device_attribute *attr, char *buf)
101{
102 struct mtd_info *mtd = dev_get_drvdata(dev);
103 char *type;
104
105 switch (mtd->type) {
106 case MTD_ABSENT:
107 type = "absent";
108 break;
109 case MTD_RAM:
110 type = "ram";
111 break;
112 case MTD_ROM:
113 type = "rom";
114 break;
115 case MTD_NORFLASH:
116 type = "nor";
117 break;
118 case MTD_NANDFLASH:
119 type = "nand";
120 break;
121 case MTD_DATAFLASH:
122 type = "dataflash";
123 break;
124 case MTD_UBIVOLUME:
125 type = "ubi";
126 break;
127 case MTD_MLCNANDFLASH:
128 type = "mlc-nand";
129 break;
130 default:
131 type = "unknown";
132 }
133
134 return snprintf(buf, PAGE_SIZE, "%s\n", type);
135}
136static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
137
138static ssize_t mtd_flags_show(struct device *dev,
139 struct device_attribute *attr, char *buf)
140{
141 struct mtd_info *mtd = dev_get_drvdata(dev);
142
143 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
144}
145static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
146
147static ssize_t mtd_size_show(struct device *dev,
148 struct device_attribute *attr, char *buf)
149{
150 struct mtd_info *mtd = dev_get_drvdata(dev);
151
152 return snprintf(buf, PAGE_SIZE, "%llu\n",
153 (unsigned long long)mtd->size);
154}
155static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
156
157static ssize_t mtd_erasesize_show(struct device *dev,
158 struct device_attribute *attr, char *buf)
159{
160 struct mtd_info *mtd = dev_get_drvdata(dev);
161
162 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
163}
164static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
165
166static ssize_t mtd_writesize_show(struct device *dev,
167 struct device_attribute *attr, char *buf)
168{
169 struct mtd_info *mtd = dev_get_drvdata(dev);
170
171 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
172}
173static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
174
175static ssize_t mtd_subpagesize_show(struct device *dev,
176 struct device_attribute *attr, char *buf)
177{
178 struct mtd_info *mtd = dev_get_drvdata(dev);
179 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
180
181 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
182}
183static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
184
185static ssize_t mtd_oobsize_show(struct device *dev,
186 struct device_attribute *attr, char *buf)
187{
188 struct mtd_info *mtd = dev_get_drvdata(dev);
189
190 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
191}
192static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
193
194static ssize_t mtd_oobavail_show(struct device *dev,
195 struct device_attribute *attr, char *buf)
196{
197 struct mtd_info *mtd = dev_get_drvdata(dev);
198
199 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->oobavail);
200}
201static DEVICE_ATTR(oobavail, S_IRUGO, mtd_oobavail_show, NULL);
202
203static ssize_t mtd_numeraseregions_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
205{
206 struct mtd_info *mtd = dev_get_drvdata(dev);
207
208 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
209}
210static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
211 NULL);
212
213static ssize_t mtd_name_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
215{
216 struct mtd_info *mtd = dev_get_drvdata(dev);
217
218 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
219}
220static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
221
222static ssize_t mtd_ecc_strength_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
224{
225 struct mtd_info *mtd = dev_get_drvdata(dev);
226
227 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
228}
229static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
230
231static ssize_t mtd_bitflip_threshold_show(struct device *dev,
232 struct device_attribute *attr,
233 char *buf)
234{
235 struct mtd_info *mtd = dev_get_drvdata(dev);
236
237 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
238}
239
240static ssize_t mtd_bitflip_threshold_store(struct device *dev,
241 struct device_attribute *attr,
242 const char *buf, size_t count)
243{
244 struct mtd_info *mtd = dev_get_drvdata(dev);
245 unsigned int bitflip_threshold;
246 int retval;
247
248 retval = kstrtouint(buf, 0, &bitflip_threshold);
249 if (retval)
250 return retval;
251
252 mtd->bitflip_threshold = bitflip_threshold;
253 return count;
254}
255static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
256 mtd_bitflip_threshold_show,
257 mtd_bitflip_threshold_store);
258
259static ssize_t mtd_ecc_step_size_show(struct device *dev,
260 struct device_attribute *attr, char *buf)
261{
262 struct mtd_info *mtd = dev_get_drvdata(dev);
263
264 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
265
266}
267static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
268
269static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
270 struct device_attribute *attr, char *buf)
271{
272 struct mtd_info *mtd = dev_get_drvdata(dev);
273 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
274
275 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
276}
277static DEVICE_ATTR(corrected_bits, S_IRUGO,
278 mtd_ecc_stats_corrected_show, NULL);
279
280static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
281 struct device_attribute *attr, char *buf)
282{
283 struct mtd_info *mtd = dev_get_drvdata(dev);
284 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
285
286 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
287}
288static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
289
290static ssize_t mtd_badblocks_show(struct device *dev,
291 struct device_attribute *attr, char *buf)
292{
293 struct mtd_info *mtd = dev_get_drvdata(dev);
294 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
295
296 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
297}
298static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
299
300static ssize_t mtd_bbtblocks_show(struct device *dev,
301 struct device_attribute *attr, char *buf)
302{
303 struct mtd_info *mtd = dev_get_drvdata(dev);
304 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
305
306 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
307}
308static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
309
310static struct attribute *mtd_attrs[] = {
311 &dev_attr_type.attr,
312 &dev_attr_flags.attr,
313 &dev_attr_size.attr,
314 &dev_attr_erasesize.attr,
315 &dev_attr_writesize.attr,
316 &dev_attr_subpagesize.attr,
317 &dev_attr_oobsize.attr,
318 &dev_attr_oobavail.attr,
319 &dev_attr_numeraseregions.attr,
320 &dev_attr_name.attr,
321 &dev_attr_ecc_strength.attr,
322 &dev_attr_ecc_step_size.attr,
323 &dev_attr_corrected_bits.attr,
324 &dev_attr_ecc_failures.attr,
325 &dev_attr_bad_blocks.attr,
326 &dev_attr_bbt_blocks.attr,
327 &dev_attr_bitflip_threshold.attr,
328 NULL,
329};
330ATTRIBUTE_GROUPS(mtd);
331
332static const struct device_type mtd_devtype = {
333 .name = "mtd",
334 .groups = mtd_groups,
335 .release = mtd_release,
336};
337
338static int mtd_partid_show(struct seq_file *s, void *p)
339{
340 struct mtd_info *mtd = s->private;
341
342 seq_printf(s, "%s\n", mtd->dbg.partid);
343
344 return 0;
345}
346
347static int mtd_partid_debugfs_open(struct inode *inode, struct file *file)
348{
349 return single_open(file, mtd_partid_show, inode->i_private);
350}
351
352static const struct file_operations mtd_partid_debug_fops = {
353 .open = mtd_partid_debugfs_open,
354 .read = seq_read,
355 .llseek = seq_lseek,
356 .release = single_release,
357};
358
359static int mtd_partname_show(struct seq_file *s, void *p)
360{
361 struct mtd_info *mtd = s->private;
362
363 seq_printf(s, "%s\n", mtd->dbg.partname);
364
365 return 0;
366}
367
368static int mtd_partname_debugfs_open(struct inode *inode, struct file *file)
369{
370 return single_open(file, mtd_partname_show, inode->i_private);
371}
372
373static const struct file_operations mtd_partname_debug_fops = {
374 .open = mtd_partname_debugfs_open,
375 .read = seq_read,
376 .llseek = seq_lseek,
377 .release = single_release,
378};
379
380static struct dentry *dfs_dir_mtd;
381
382static void mtd_debugfs_populate(struct mtd_info *mtd)
383{
384 struct device *dev = &mtd->dev;
385 struct dentry *root;
386
387 if (IS_ERR_OR_NULL(dfs_dir_mtd))
388 return;
389
390 root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
391 mtd->dbg.dfs_dir = root;
392
393 if (mtd->dbg.partid)
394 debugfs_create_file("partid", 0400, root, mtd,
395 &mtd_partid_debug_fops);
396
397 if (mtd->dbg.partname)
398 debugfs_create_file("partname", 0400, root, mtd,
399 &mtd_partname_debug_fops);
400}
401
402#ifndef CONFIG_MMU
403unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
404{
405 switch (mtd->type) {
406 case MTD_RAM:
407 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
408 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
409 case MTD_ROM:
410 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
411 NOMMU_MAP_READ;
412 default:
413 return NOMMU_MAP_COPY;
414 }
415}
416EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
417#endif
418
419static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
420 void *cmd)
421{
422 struct mtd_info *mtd;
423
424 mtd = container_of(n, struct mtd_info, reboot_notifier);
425 mtd->_reboot(mtd);
426
427 return NOTIFY_DONE;
428}
429
430/**
431 * mtd_wunit_to_pairing_info - get pairing information of a wunit
432 * @mtd: pointer to new MTD device info structure
433 * @wunit: write unit we are interested in
434 * @info: returned pairing information
435 *
436 * Retrieve pairing information associated to the wunit.
437 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
438 * paired together, and where programming a page may influence the page it is
439 * paired with.
440 * The notion of page is replaced by the term wunit (write-unit) to stay
441 * consistent with the ->writesize field.
442 *
443 * The @wunit argument can be extracted from an absolute offset using
444 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
445 * to @wunit.
446 *
447 * From the pairing info the MTD user can find all the wunits paired with
448 * @wunit using the following loop:
449 *
450 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
451 * info.pair = i;
452 * mtd_pairing_info_to_wunit(mtd, &info);
453 * ...
454 * }
455 */
456int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
457 struct mtd_pairing_info *info)
458{
459 struct mtd_info *master = mtd_get_master(mtd);
460 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
461
462 if (wunit < 0 || wunit >= npairs)
463 return -EINVAL;
464
465 if (master->pairing && master->pairing->get_info)
466 return master->pairing->get_info(master, wunit, info);
467
468 info->group = 0;
469 info->pair = wunit;
470
471 return 0;
472}
473EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
474
475/**
476 * mtd_pairing_info_to_wunit - get wunit from pairing information
477 * @mtd: pointer to new MTD device info structure
478 * @info: pairing information struct
479 *
480 * Returns a positive number representing the wunit associated to the info
481 * struct, or a negative error code.
482 *
483 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
484 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
485 * doc).
486 *
487 * It can also be used to only program the first page of each pair (i.e.
488 * page attached to group 0), which allows one to use an MLC NAND in
489 * software-emulated SLC mode:
490 *
491 * info.group = 0;
492 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
493 * for (info.pair = 0; info.pair < npairs; info.pair++) {
494 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
495 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
496 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
497 * }
498 */
499int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
500 const struct mtd_pairing_info *info)
501{
502 struct mtd_info *master = mtd_get_master(mtd);
503 int ngroups = mtd_pairing_groups(master);
504 int npairs = mtd_wunit_per_eb(master) / ngroups;
505
506 if (!info || info->pair < 0 || info->pair >= npairs ||
507 info->group < 0 || info->group >= ngroups)
508 return -EINVAL;
509
510 if (master->pairing && master->pairing->get_wunit)
511 return mtd->pairing->get_wunit(master, info);
512
513 return info->pair;
514}
515EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
516
517/**
518 * mtd_pairing_groups - get the number of pairing groups
519 * @mtd: pointer to new MTD device info structure
520 *
521 * Returns the number of pairing groups.
522 *
523 * This number is usually equal to the number of bits exposed by a single
524 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
525 * to iterate over all pages of a given pair.
526 */
527int mtd_pairing_groups(struct mtd_info *mtd)
528{
529 struct mtd_info *master = mtd_get_master(mtd);
530
531 if (!master->pairing || !master->pairing->ngroups)
532 return 1;
533
534 return master->pairing->ngroups;
535}
536EXPORT_SYMBOL_GPL(mtd_pairing_groups);
537
538static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
539 void *val, size_t bytes)
540{
541 struct mtd_info *mtd = priv;
542 size_t retlen;
543 int err;
544
545 err = mtd_read(mtd, offset, bytes, &retlen, val);
546 if (err && err != -EUCLEAN)
547 return err;
548
549 return retlen == bytes ? 0 : -EIO;
550}
551
552static int mtd_nvmem_add(struct mtd_info *mtd)
553{
554 struct nvmem_config config = {};
555
556 config.id = -1;
557 config.dev = &mtd->dev;
558 config.name = dev_name(&mtd->dev);
559 config.owner = THIS_MODULE;
560 config.reg_read = mtd_nvmem_reg_read;
561 config.size = mtd->size;
562 config.word_size = 1;
563 config.stride = 1;
564 config.read_only = true;
565 config.root_only = true;
566 config.no_of_node = true;
567 config.priv = mtd;
568
569 mtd->nvmem = nvmem_register(&config);
570 if (IS_ERR(mtd->nvmem)) {
571 /* Just ignore if there is no NVMEM support in the kernel */
572 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
573 mtd->nvmem = NULL;
574 } else {
575 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
576 return PTR_ERR(mtd->nvmem);
577 }
578 }
579
580 return 0;
581}
582
583/**
584 * add_mtd_device - register an MTD device
585 * @mtd: pointer to new MTD device info structure
586 *
587 * Add a device to the list of MTD devices present in the system, and
588 * notify each currently active MTD 'user' of its arrival. Returns
589 * zero on success or non-zero on failure.
590 */
591
592int add_mtd_device(struct mtd_info *mtd)
593{
594 struct mtd_info *master = mtd_get_master(mtd);
595 struct mtd_notifier *not;
596 int i, error;
597
598 /*
599 * May occur, for instance, on buggy drivers which call
600 * mtd_device_parse_register() multiple times on the same master MTD,
601 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
602 */
603 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
604 return -EEXIST;
605
606 BUG_ON(mtd->writesize == 0);
607
608 /*
609 * MTD drivers should implement ->_{write,read}() or
610 * ->_{write,read}_oob(), but not both.
611 */
612 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
613 (mtd->_read && mtd->_read_oob)))
614 return -EINVAL;
615
616 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
617 !(mtd->flags & MTD_NO_ERASE)))
618 return -EINVAL;
619
620 /*
621 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
622 * master is an MLC NAND and has a proper pairing scheme defined.
623 * We also reject masters that implement ->_writev() for now, because
624 * NAND controller drivers don't implement this hook, and adding the
625 * SLC -> MLC address/length conversion to this path is useless if we
626 * don't have a user.
627 */
628 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
629 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
630 !master->pairing || master->_writev))
631 return -EINVAL;
632
633 mutex_lock(&mtd_table_mutex);
634
635 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
636 if (i < 0) {
637 error = i;
638 goto fail_locked;
639 }
640
641 mtd->index = i;
642 mtd->usecount = 0;
643
644 /* default value if not set by driver */
645 if (mtd->bitflip_threshold == 0)
646 mtd->bitflip_threshold = mtd->ecc_strength;
647
648 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
649 int ngroups = mtd_pairing_groups(master);
650
651 mtd->erasesize /= ngroups;
652 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
653 mtd->erasesize;
654 }
655
656 if (is_power_of_2(mtd->erasesize))
657 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
658 else
659 mtd->erasesize_shift = 0;
660
661 if (is_power_of_2(mtd->writesize))
662 mtd->writesize_shift = ffs(mtd->writesize) - 1;
663 else
664 mtd->writesize_shift = 0;
665
666 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
667 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
668
669 /* Some chips always power up locked. Unlock them now */
670 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
671 error = mtd_unlock(mtd, 0, mtd->size);
672 if (error && error != -EOPNOTSUPP)
673 printk(KERN_WARNING
674 "%s: unlock failed, writes may not work\n",
675 mtd->name);
676 /* Ignore unlock failures? */
677 error = 0;
678 }
679
680 /* Caller should have set dev.parent to match the
681 * physical device, if appropriate.
682 */
683 mtd->dev.type = &mtd_devtype;
684 mtd->dev.class = &mtd_class;
685 mtd->dev.devt = MTD_DEVT(i);
686 dev_set_name(&mtd->dev, "mtd%d", i);
687 dev_set_drvdata(&mtd->dev, mtd);
688 of_node_get(mtd_get_of_node(mtd));
689 error = device_register(&mtd->dev);
690 if (error)
691 goto fail_added;
692
693 /* Add the nvmem provider */
694 error = mtd_nvmem_add(mtd);
695 if (error)
696 goto fail_nvmem_add;
697
698 mtd_debugfs_populate(mtd);
699
700 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
701 "mtd%dro", i);
702
703 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
704 /* No need to get a refcount on the module containing
705 the notifier, since we hold the mtd_table_mutex */
706 list_for_each_entry(not, &mtd_notifiers, list)
707 not->add(mtd);
708
709 mutex_unlock(&mtd_table_mutex);
710 /* We _know_ we aren't being removed, because
711 our caller is still holding us here. So none
712 of this try_ nonsense, and no bitching about it
713 either. :) */
714 __module_get(THIS_MODULE);
715 return 0;
716
717fail_nvmem_add:
718 device_unregister(&mtd->dev);
719fail_added:
720 of_node_put(mtd_get_of_node(mtd));
721 idr_remove(&mtd_idr, i);
722fail_locked:
723 mutex_unlock(&mtd_table_mutex);
724 return error;
725}
726
727/**
728 * del_mtd_device - unregister an MTD device
729 * @mtd: pointer to MTD device info structure
730 *
731 * Remove a device from the list of MTD devices present in the system,
732 * and notify each currently active MTD 'user' of its departure.
733 * Returns zero on success or 1 on failure, which currently will happen
734 * if the requested device does not appear to be present in the list.
735 */
736
737int del_mtd_device(struct mtd_info *mtd)
738{
739 int ret;
740 struct mtd_notifier *not;
741
742 mutex_lock(&mtd_table_mutex);
743
744 debugfs_remove_recursive(mtd->dbg.dfs_dir);
745
746 if (idr_find(&mtd_idr, mtd->index) != mtd) {
747 ret = -ENODEV;
748 goto out_error;
749 }
750
751 /* No need to get a refcount on the module containing
752 the notifier, since we hold the mtd_table_mutex */
753 list_for_each_entry(not, &mtd_notifiers, list)
754 not->remove(mtd);
755
756 if (mtd->usecount) {
757 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
758 mtd->index, mtd->name, mtd->usecount);
759 ret = -EBUSY;
760 } else {
761 /* Try to remove the NVMEM provider */
762 if (mtd->nvmem)
763 nvmem_unregister(mtd->nvmem);
764
765 device_unregister(&mtd->dev);
766
767 idr_remove(&mtd_idr, mtd->index);
768 of_node_put(mtd_get_of_node(mtd));
769
770 module_put(THIS_MODULE);
771 ret = 0;
772 }
773
774out_error:
775 mutex_unlock(&mtd_table_mutex);
776 return ret;
777}
778
779/*
780 * Set a few defaults based on the parent devices, if not provided by the
781 * driver
782 */
783static void mtd_set_dev_defaults(struct mtd_info *mtd)
784{
785 if (mtd->dev.parent) {
786 if (!mtd->owner && mtd->dev.parent->driver)
787 mtd->owner = mtd->dev.parent->driver->owner;
788 if (!mtd->name)
789 mtd->name = dev_name(mtd->dev.parent);
790 } else {
791 pr_debug("mtd device won't show a device symlink in sysfs\n");
792 }
793
794 INIT_LIST_HEAD(&mtd->partitions);
795 mutex_init(&mtd->master.partitions_lock);
796}
797
798/**
799 * mtd_device_parse_register - parse partitions and register an MTD device.
800 *
801 * @mtd: the MTD device to register
802 * @types: the list of MTD partition probes to try, see
803 * 'parse_mtd_partitions()' for more information
804 * @parser_data: MTD partition parser-specific data
805 * @parts: fallback partition information to register, if parsing fails;
806 * only valid if %nr_parts > %0
807 * @nr_parts: the number of partitions in parts, if zero then the full
808 * MTD device is registered if no partition info is found
809 *
810 * This function aggregates MTD partitions parsing (done by
811 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
812 * basically follows the most common pattern found in many MTD drivers:
813 *
814 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
815 * registered first.
816 * * Then It tries to probe partitions on MTD device @mtd using parsers
817 * specified in @types (if @types is %NULL, then the default list of parsers
818 * is used, see 'parse_mtd_partitions()' for more information). If none are
819 * found this functions tries to fallback to information specified in
820 * @parts/@nr_parts.
821 * * If no partitions were found this function just registers the MTD device
822 * @mtd and exits.
823 *
824 * Returns zero in case of success and a negative error code in case of failure.
825 */
826int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
827 struct mtd_part_parser_data *parser_data,
828 const struct mtd_partition *parts,
829 int nr_parts)
830{
831 int ret;
832
833 mtd_set_dev_defaults(mtd);
834
835 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
836 ret = add_mtd_device(mtd);
837 if (ret)
838 return ret;
839 }
840
841 /* Prefer parsed partitions over driver-provided fallback */
842 ret = parse_mtd_partitions(mtd, types, parser_data);
843 if (ret > 0)
844 ret = 0;
845 else if (nr_parts)
846 ret = add_mtd_partitions(mtd, parts, nr_parts);
847 else if (!device_is_registered(&mtd->dev))
848 ret = add_mtd_device(mtd);
849 else
850 ret = 0;
851
852 if (ret)
853 goto out;
854
855 /*
856 * FIXME: some drivers unfortunately call this function more than once.
857 * So we have to check if we've already assigned the reboot notifier.
858 *
859 * Generally, we can make multiple calls work for most cases, but it
860 * does cause problems with parse_mtd_partitions() above (e.g.,
861 * cmdlineparts will register partitions more than once).
862 */
863 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
864 "MTD already registered\n");
865 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
866 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
867 register_reboot_notifier(&mtd->reboot_notifier);
868 }
869
870out:
871 if (ret && device_is_registered(&mtd->dev))
872 del_mtd_device(mtd);
873
874 return ret;
875}
876EXPORT_SYMBOL_GPL(mtd_device_parse_register);
877
878/**
879 * mtd_device_unregister - unregister an existing MTD device.
880 *
881 * @master: the MTD device to unregister. This will unregister both the master
882 * and any partitions if registered.
883 */
884int mtd_device_unregister(struct mtd_info *master)
885{
886 int err;
887
888 if (master->_reboot)
889 unregister_reboot_notifier(&master->reboot_notifier);
890
891 err = del_mtd_partitions(master);
892 if (err)
893 return err;
894
895 if (!device_is_registered(&master->dev))
896 return 0;
897
898 return del_mtd_device(master);
899}
900EXPORT_SYMBOL_GPL(mtd_device_unregister);
901
902/**
903 * register_mtd_user - register a 'user' of MTD devices.
904 * @new: pointer to notifier info structure
905 *
906 * Registers a pair of callbacks function to be called upon addition
907 * or removal of MTD devices. Causes the 'add' callback to be immediately
908 * invoked for each MTD device currently present in the system.
909 */
910void register_mtd_user (struct mtd_notifier *new)
911{
912 struct mtd_info *mtd;
913
914 mutex_lock(&mtd_table_mutex);
915
916 list_add(&new->list, &mtd_notifiers);
917
918 __module_get(THIS_MODULE);
919
920 mtd_for_each_device(mtd)
921 new->add(mtd);
922
923 mutex_unlock(&mtd_table_mutex);
924}
925EXPORT_SYMBOL_GPL(register_mtd_user);
926
927/**
928 * unregister_mtd_user - unregister a 'user' of MTD devices.
929 * @old: pointer to notifier info structure
930 *
931 * Removes a callback function pair from the list of 'users' to be
932 * notified upon addition or removal of MTD devices. Causes the
933 * 'remove' callback to be immediately invoked for each MTD device
934 * currently present in the system.
935 */
936int unregister_mtd_user (struct mtd_notifier *old)
937{
938 struct mtd_info *mtd;
939
940 mutex_lock(&mtd_table_mutex);
941
942 module_put(THIS_MODULE);
943
944 mtd_for_each_device(mtd)
945 old->remove(mtd);
946
947 list_del(&old->list);
948 mutex_unlock(&mtd_table_mutex);
949 return 0;
950}
951EXPORT_SYMBOL_GPL(unregister_mtd_user);
952
953/**
954 * get_mtd_device - obtain a validated handle for an MTD device
955 * @mtd: last known address of the required MTD device
956 * @num: internal device number of the required MTD device
957 *
958 * Given a number and NULL address, return the num'th entry in the device
959 * table, if any. Given an address and num == -1, search the device table
960 * for a device with that address and return if it's still present. Given
961 * both, return the num'th driver only if its address matches. Return
962 * error code if not.
963 */
964struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
965{
966 struct mtd_info *ret = NULL, *other;
967 int err = -ENODEV;
968
969 mutex_lock(&mtd_table_mutex);
970
971 if (num == -1) {
972 mtd_for_each_device(other) {
973 if (other == mtd) {
974 ret = mtd;
975 break;
976 }
977 }
978 } else if (num >= 0) {
979 ret = idr_find(&mtd_idr, num);
980 if (mtd && mtd != ret)
981 ret = NULL;
982 }
983
984 if (!ret) {
985 ret = ERR_PTR(err);
986 goto out;
987 }
988
989 err = __get_mtd_device(ret);
990 if (err)
991 ret = ERR_PTR(err);
992out:
993 mutex_unlock(&mtd_table_mutex);
994 return ret;
995}
996EXPORT_SYMBOL_GPL(get_mtd_device);
997
998
999int __get_mtd_device(struct mtd_info *mtd)
1000{
1001 struct mtd_info *master = mtd_get_master(mtd);
1002 int err;
1003
1004 if (!try_module_get(master->owner))
1005 return -ENODEV;
1006
1007 if (master->_get_device) {
1008 err = master->_get_device(mtd);
1009
1010 if (err) {
1011 module_put(master->owner);
1012 return err;
1013 }
1014 }
1015
1016 while (mtd->parent) {
1017 mtd->usecount++;
1018 mtd = mtd->parent;
1019 }
1020
1021 return 0;
1022}
1023EXPORT_SYMBOL_GPL(__get_mtd_device);
1024
1025/**
1026 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1027 * device name
1028 * @name: MTD device name to open
1029 *
1030 * This function returns MTD device description structure in case of
1031 * success and an error code in case of failure.
1032 */
1033struct mtd_info *get_mtd_device_nm(const char *name)
1034{
1035 int err = -ENODEV;
1036 struct mtd_info *mtd = NULL, *other;
1037
1038 mutex_lock(&mtd_table_mutex);
1039
1040 mtd_for_each_device(other) {
1041 if (!strcmp(name, other->name)) {
1042 mtd = other;
1043 break;
1044 }
1045 }
1046
1047 if (!mtd)
1048 goto out_unlock;
1049
1050 err = __get_mtd_device(mtd);
1051 if (err)
1052 goto out_unlock;
1053
1054 mutex_unlock(&mtd_table_mutex);
1055 return mtd;
1056
1057out_unlock:
1058 mutex_unlock(&mtd_table_mutex);
1059 return ERR_PTR(err);
1060}
1061EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1062
1063void put_mtd_device(struct mtd_info *mtd)
1064{
1065 mutex_lock(&mtd_table_mutex);
1066 __put_mtd_device(mtd);
1067 mutex_unlock(&mtd_table_mutex);
1068
1069}
1070EXPORT_SYMBOL_GPL(put_mtd_device);
1071
1072void __put_mtd_device(struct mtd_info *mtd)
1073{
1074 struct mtd_info *master = mtd_get_master(mtd);
1075
1076 while (mtd->parent) {
1077 --mtd->usecount;
1078 BUG_ON(mtd->usecount < 0);
1079 mtd = mtd->parent;
1080 }
1081
1082 if (master->_put_device)
1083 master->_put_device(master);
1084
1085 module_put(master->owner);
1086}
1087EXPORT_SYMBOL_GPL(__put_mtd_device);
1088
1089/*
1090 * Erase is an synchronous operation. Device drivers are epected to return a
1091 * negative error code if the operation failed and update instr->fail_addr
1092 * to point the portion that was not properly erased.
1093 */
1094int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1095{
1096 struct mtd_info *master = mtd_get_master(mtd);
1097 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1098 struct erase_info adjinstr;
1099 int ret;
1100
1101 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1102 adjinstr = *instr;
1103
1104 if (!mtd->erasesize || !master->_erase)
1105 return -ENOTSUPP;
1106
1107 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1108 return -EINVAL;
1109 if (!(mtd->flags & MTD_WRITEABLE))
1110 return -EROFS;
1111
1112 if (!instr->len)
1113 return 0;
1114
1115 ledtrig_mtd_activity();
1116
1117 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1118 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1119 master->erasesize;
1120 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1121 master->erasesize) -
1122 adjinstr.addr;
1123 }
1124
1125 adjinstr.addr += mst_ofs;
1126
1127 ret = master->_erase(master, &adjinstr);
1128
1129 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1130 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1131 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1132 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1133 master);
1134 instr->fail_addr *= mtd->erasesize;
1135 }
1136 }
1137
1138 return ret;
1139}
1140EXPORT_SYMBOL_GPL(mtd_erase);
1141
1142/*
1143 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1144 */
1145int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1146 void **virt, resource_size_t *phys)
1147{
1148 struct mtd_info *master = mtd_get_master(mtd);
1149
1150 *retlen = 0;
1151 *virt = NULL;
1152 if (phys)
1153 *phys = 0;
1154 if (!master->_point)
1155 return -EOPNOTSUPP;
1156 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1157 return -EINVAL;
1158 if (!len)
1159 return 0;
1160
1161 from = mtd_get_master_ofs(mtd, from);
1162 return master->_point(master, from, len, retlen, virt, phys);
1163}
1164EXPORT_SYMBOL_GPL(mtd_point);
1165
1166/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1167int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1168{
1169 struct mtd_info *master = mtd_get_master(mtd);
1170
1171 if (!master->_unpoint)
1172 return -EOPNOTSUPP;
1173 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1174 return -EINVAL;
1175 if (!len)
1176 return 0;
1177 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1178}
1179EXPORT_SYMBOL_GPL(mtd_unpoint);
1180
1181/*
1182 * Allow NOMMU mmap() to directly map the device (if not NULL)
1183 * - return the address to which the offset maps
1184 * - return -ENOSYS to indicate refusal to do the mapping
1185 */
1186unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1187 unsigned long offset, unsigned long flags)
1188{
1189 size_t retlen;
1190 void *virt;
1191 int ret;
1192
1193 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1194 if (ret)
1195 return ret;
1196 if (retlen != len) {
1197 mtd_unpoint(mtd, offset, retlen);
1198 return -ENOSYS;
1199 }
1200 return (unsigned long)virt;
1201}
1202EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1203
1204static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1205 const struct mtd_ecc_stats *old_stats)
1206{
1207 struct mtd_ecc_stats diff;
1208
1209 if (master == mtd)
1210 return;
1211
1212 diff = master->ecc_stats;
1213 diff.failed -= old_stats->failed;
1214 diff.corrected -= old_stats->corrected;
1215
1216 while (mtd->parent) {
1217 mtd->ecc_stats.failed += diff.failed;
1218 mtd->ecc_stats.corrected += diff.corrected;
1219 mtd = mtd->parent;
1220 }
1221}
1222
1223int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1224 u_char *buf)
1225{
1226 struct mtd_oob_ops ops = {
1227 .len = len,
1228 .datbuf = buf,
1229 };
1230 int ret;
1231
1232 ret = mtd_read_oob(mtd, from, &ops);
1233 *retlen = ops.retlen;
1234
1235 return ret;
1236}
1237EXPORT_SYMBOL_GPL(mtd_read);
1238
1239int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1240 const u_char *buf)
1241{
1242 struct mtd_oob_ops ops = {
1243 .len = len,
1244 .datbuf = (u8 *)buf,
1245 };
1246 int ret;
1247
1248 ret = mtd_write_oob(mtd, to, &ops);
1249 *retlen = ops.retlen;
1250
1251 return ret;
1252}
1253EXPORT_SYMBOL_GPL(mtd_write);
1254
1255/*
1256 * In blackbox flight recorder like scenarios we want to make successful writes
1257 * in interrupt context. panic_write() is only intended to be called when its
1258 * known the kernel is about to panic and we need the write to succeed. Since
1259 * the kernel is not going to be running for much longer, this function can
1260 * break locks and delay to ensure the write succeeds (but not sleep).
1261 */
1262int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1263 const u_char *buf)
1264{
1265 struct mtd_info *master = mtd_get_master(mtd);
1266
1267 *retlen = 0;
1268 if (!master->_panic_write)
1269 return -EOPNOTSUPP;
1270 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1271 return -EINVAL;
1272 if (!(mtd->flags & MTD_WRITEABLE))
1273 return -EROFS;
1274 if (!len)
1275 return 0;
1276 if (!master->oops_panic_write)
1277 master->oops_panic_write = true;
1278
1279 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1280 retlen, buf);
1281}
1282EXPORT_SYMBOL_GPL(mtd_panic_write);
1283
1284static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1285 struct mtd_oob_ops *ops)
1286{
1287 /*
1288 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1289 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1290 * this case.
1291 */
1292 if (!ops->datbuf)
1293 ops->len = 0;
1294
1295 if (!ops->oobbuf)
1296 ops->ooblen = 0;
1297
1298 if (offs < 0 || offs + ops->len > mtd->size)
1299 return -EINVAL;
1300
1301 if (ops->ooblen) {
1302 size_t maxooblen;
1303
1304 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1305 return -EINVAL;
1306
1307 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1308 mtd_div_by_ws(offs, mtd)) *
1309 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1310 if (ops->ooblen > maxooblen)
1311 return -EINVAL;
1312 }
1313
1314 return 0;
1315}
1316
1317static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1318 struct mtd_oob_ops *ops)
1319{
1320 struct mtd_info *master = mtd_get_master(mtd);
1321 int ret;
1322
1323 from = mtd_get_master_ofs(mtd, from);
1324 if (master->_read_oob)
1325 ret = master->_read_oob(master, from, ops);
1326 else
1327 ret = master->_read(master, from, ops->len, &ops->retlen,
1328 ops->datbuf);
1329
1330 return ret;
1331}
1332
1333static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1334 struct mtd_oob_ops *ops)
1335{
1336 struct mtd_info *master = mtd_get_master(mtd);
1337 int ret;
1338
1339 to = mtd_get_master_ofs(mtd, to);
1340 if (master->_write_oob)
1341 ret = master->_write_oob(master, to, ops);
1342 else
1343 ret = master->_write(master, to, ops->len, &ops->retlen,
1344 ops->datbuf);
1345
1346 return ret;
1347}
1348
1349static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1350 struct mtd_oob_ops *ops)
1351{
1352 struct mtd_info *master = mtd_get_master(mtd);
1353 int ngroups = mtd_pairing_groups(master);
1354 int npairs = mtd_wunit_per_eb(master) / ngroups;
1355 struct mtd_oob_ops adjops = *ops;
1356 unsigned int wunit, oobavail;
1357 struct mtd_pairing_info info;
1358 int max_bitflips = 0;
1359 u32 ebofs, pageofs;
1360 loff_t base, pos;
1361
1362 ebofs = mtd_mod_by_eb(start, mtd);
1363 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1364 info.group = 0;
1365 info.pair = mtd_div_by_ws(ebofs, mtd);
1366 pageofs = mtd_mod_by_ws(ebofs, mtd);
1367 oobavail = mtd_oobavail(mtd, ops);
1368
1369 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1370 int ret;
1371
1372 if (info.pair >= npairs) {
1373 info.pair = 0;
1374 base += master->erasesize;
1375 }
1376
1377 wunit = mtd_pairing_info_to_wunit(master, &info);
1378 pos = mtd_wunit_to_offset(mtd, base, wunit);
1379
1380 adjops.len = ops->len - ops->retlen;
1381 if (adjops.len > mtd->writesize - pageofs)
1382 adjops.len = mtd->writesize - pageofs;
1383
1384 adjops.ooblen = ops->ooblen - ops->oobretlen;
1385 if (adjops.ooblen > oobavail - adjops.ooboffs)
1386 adjops.ooblen = oobavail - adjops.ooboffs;
1387
1388 if (read) {
1389 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1390 if (ret > 0)
1391 max_bitflips = max(max_bitflips, ret);
1392 } else {
1393 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1394 }
1395
1396 if (ret < 0)
1397 return ret;
1398
1399 max_bitflips = max(max_bitflips, ret);
1400 ops->retlen += adjops.retlen;
1401 ops->oobretlen += adjops.oobretlen;
1402 adjops.datbuf += adjops.retlen;
1403 adjops.oobbuf += adjops.oobretlen;
1404 adjops.ooboffs = 0;
1405 pageofs = 0;
1406 info.pair++;
1407 }
1408
1409 return max_bitflips;
1410}
1411
1412int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1413{
1414 struct mtd_info *master = mtd_get_master(mtd);
1415 struct mtd_ecc_stats old_stats = master->ecc_stats;
1416 int ret_code;
1417
1418 ops->retlen = ops->oobretlen = 0;
1419
1420 ret_code = mtd_check_oob_ops(mtd, from, ops);
1421 if (ret_code)
1422 return ret_code;
1423
1424 ledtrig_mtd_activity();
1425
1426 /* Check the validity of a potential fallback on mtd->_read */
1427 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1428 return -EOPNOTSUPP;
1429
1430 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1431 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1432 else
1433 ret_code = mtd_read_oob_std(mtd, from, ops);
1434
1435 mtd_update_ecc_stats(mtd, master, &old_stats);
1436
1437 /*
1438 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1439 * similar to mtd->_read(), returning a non-negative integer
1440 * representing max bitflips. In other cases, mtd->_read_oob() may
1441 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1442 */
1443 if (unlikely(ret_code < 0))
1444 return ret_code;
1445 if (mtd->ecc_strength == 0)
1446 return 0; /* device lacks ecc */
1447 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1448}
1449EXPORT_SYMBOL_GPL(mtd_read_oob);
1450
1451int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1452 struct mtd_oob_ops *ops)
1453{
1454 struct mtd_info *master = mtd_get_master(mtd);
1455 int ret;
1456
1457 ops->retlen = ops->oobretlen = 0;
1458
1459 if (!(mtd->flags & MTD_WRITEABLE))
1460 return -EROFS;
1461
1462 ret = mtd_check_oob_ops(mtd, to, ops);
1463 if (ret)
1464 return ret;
1465
1466 ledtrig_mtd_activity();
1467
1468 /* Check the validity of a potential fallback on mtd->_write */
1469 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1470 return -EOPNOTSUPP;
1471
1472 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1473 return mtd_io_emulated_slc(mtd, to, false, ops);
1474
1475 return mtd_write_oob_std(mtd, to, ops);
1476}
1477EXPORT_SYMBOL_GPL(mtd_write_oob);
1478
1479/**
1480 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1481 * @mtd: MTD device structure
1482 * @section: ECC section. Depending on the layout you may have all the ECC
1483 * bytes stored in a single contiguous section, or one section
1484 * per ECC chunk (and sometime several sections for a single ECC
1485 * ECC chunk)
1486 * @oobecc: OOB region struct filled with the appropriate ECC position
1487 * information
1488 *
1489 * This function returns ECC section information in the OOB area. If you want
1490 * to get all the ECC bytes information, then you should call
1491 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1492 *
1493 * Returns zero on success, a negative error code otherwise.
1494 */
1495int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1496 struct mtd_oob_region *oobecc)
1497{
1498 struct mtd_info *master = mtd_get_master(mtd);
1499
1500 memset(oobecc, 0, sizeof(*oobecc));
1501
1502 if (!master || section < 0)
1503 return -EINVAL;
1504
1505 if (!master->ooblayout || !master->ooblayout->ecc)
1506 return -ENOTSUPP;
1507
1508 return master->ooblayout->ecc(master, section, oobecc);
1509}
1510EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1511
1512/**
1513 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1514 * section
1515 * @mtd: MTD device structure
1516 * @section: Free section you are interested in. Depending on the layout
1517 * you may have all the free bytes stored in a single contiguous
1518 * section, or one section per ECC chunk plus an extra section
1519 * for the remaining bytes (or other funky layout).
1520 * @oobfree: OOB region struct filled with the appropriate free position
1521 * information
1522 *
1523 * This function returns free bytes position in the OOB area. If you want
1524 * to get all the free bytes information, then you should call
1525 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1526 *
1527 * Returns zero on success, a negative error code otherwise.
1528 */
1529int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1530 struct mtd_oob_region *oobfree)
1531{
1532 struct mtd_info *master = mtd_get_master(mtd);
1533
1534 memset(oobfree, 0, sizeof(*oobfree));
1535
1536 if (!master || section < 0)
1537 return -EINVAL;
1538
1539 if (!master->ooblayout || !master->ooblayout->free)
1540 return -ENOTSUPP;
1541
1542 return master->ooblayout->free(master, section, oobfree);
1543}
1544EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1545
1546/**
1547 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1548 * @mtd: mtd info structure
1549 * @byte: the byte we are searching for
1550 * @sectionp: pointer where the section id will be stored
1551 * @oobregion: used to retrieve the ECC position
1552 * @iter: iterator function. Should be either mtd_ooblayout_free or
1553 * mtd_ooblayout_ecc depending on the region type you're searching for
1554 *
1555 * This function returns the section id and oobregion information of a
1556 * specific byte. For example, say you want to know where the 4th ECC byte is
1557 * stored, you'll use:
1558 *
1559 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1560 *
1561 * Returns zero on success, a negative error code otherwise.
1562 */
1563static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1564 int *sectionp, struct mtd_oob_region *oobregion,
1565 int (*iter)(struct mtd_info *,
1566 int section,
1567 struct mtd_oob_region *oobregion))
1568{
1569 int pos = 0, ret, section = 0;
1570
1571 memset(oobregion, 0, sizeof(*oobregion));
1572
1573 while (1) {
1574 ret = iter(mtd, section, oobregion);
1575 if (ret)
1576 return ret;
1577
1578 if (pos + oobregion->length > byte)
1579 break;
1580
1581 pos += oobregion->length;
1582 section++;
1583 }
1584
1585 /*
1586 * Adjust region info to make it start at the beginning at the
1587 * 'start' ECC byte.
1588 */
1589 oobregion->offset += byte - pos;
1590 oobregion->length -= byte - pos;
1591 *sectionp = section;
1592
1593 return 0;
1594}
1595
1596/**
1597 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1598 * ECC byte
1599 * @mtd: mtd info structure
1600 * @eccbyte: the byte we are searching for
1601 * @sectionp: pointer where the section id will be stored
1602 * @oobregion: OOB region information
1603 *
1604 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1605 * byte.
1606 *
1607 * Returns zero on success, a negative error code otherwise.
1608 */
1609int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1610 int *section,
1611 struct mtd_oob_region *oobregion)
1612{
1613 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1614 mtd_ooblayout_ecc);
1615}
1616EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1617
1618/**
1619 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1620 * @mtd: mtd info structure
1621 * @buf: destination buffer to store OOB bytes
1622 * @oobbuf: OOB buffer
1623 * @start: first byte to retrieve
1624 * @nbytes: number of bytes to retrieve
1625 * @iter: section iterator
1626 *
1627 * Extract bytes attached to a specific category (ECC or free)
1628 * from the OOB buffer and copy them into buf.
1629 *
1630 * Returns zero on success, a negative error code otherwise.
1631 */
1632static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1633 const u8 *oobbuf, int start, int nbytes,
1634 int (*iter)(struct mtd_info *,
1635 int section,
1636 struct mtd_oob_region *oobregion))
1637{
1638 struct mtd_oob_region oobregion;
1639 int section, ret;
1640
1641 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1642 &oobregion, iter);
1643
1644 while (!ret) {
1645 int cnt;
1646
1647 cnt = min_t(int, nbytes, oobregion.length);
1648 memcpy(buf, oobbuf + oobregion.offset, cnt);
1649 buf += cnt;
1650 nbytes -= cnt;
1651
1652 if (!nbytes)
1653 break;
1654
1655 ret = iter(mtd, ++section, &oobregion);
1656 }
1657
1658 return ret;
1659}
1660
1661/**
1662 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1663 * @mtd: mtd info structure
1664 * @buf: source buffer to get OOB bytes from
1665 * @oobbuf: OOB buffer
1666 * @start: first OOB byte to set
1667 * @nbytes: number of OOB bytes to set
1668 * @iter: section iterator
1669 *
1670 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1671 * is selected by passing the appropriate iterator.
1672 *
1673 * Returns zero on success, a negative error code otherwise.
1674 */
1675static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1676 u8 *oobbuf, int start, int nbytes,
1677 int (*iter)(struct mtd_info *,
1678 int section,
1679 struct mtd_oob_region *oobregion))
1680{
1681 struct mtd_oob_region oobregion;
1682 int section, ret;
1683
1684 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1685 &oobregion, iter);
1686
1687 while (!ret) {
1688 int cnt;
1689
1690 cnt = min_t(int, nbytes, oobregion.length);
1691 memcpy(oobbuf + oobregion.offset, buf, cnt);
1692 buf += cnt;
1693 nbytes -= cnt;
1694
1695 if (!nbytes)
1696 break;
1697
1698 ret = iter(mtd, ++section, &oobregion);
1699 }
1700
1701 return ret;
1702}
1703
1704/**
1705 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1706 * @mtd: mtd info structure
1707 * @iter: category iterator
1708 *
1709 * Count the number of bytes in a given category.
1710 *
1711 * Returns a positive value on success, a negative error code otherwise.
1712 */
1713static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1714 int (*iter)(struct mtd_info *,
1715 int section,
1716 struct mtd_oob_region *oobregion))
1717{
1718 struct mtd_oob_region oobregion;
1719 int section = 0, ret, nbytes = 0;
1720
1721 while (1) {
1722 ret = iter(mtd, section++, &oobregion);
1723 if (ret) {
1724 if (ret == -ERANGE)
1725 ret = nbytes;
1726 break;
1727 }
1728
1729 nbytes += oobregion.length;
1730 }
1731
1732 return ret;
1733}
1734
1735/**
1736 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1737 * @mtd: mtd info structure
1738 * @eccbuf: destination buffer to store ECC bytes
1739 * @oobbuf: OOB buffer
1740 * @start: first ECC byte to retrieve
1741 * @nbytes: number of ECC bytes to retrieve
1742 *
1743 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1744 *
1745 * Returns zero on success, a negative error code otherwise.
1746 */
1747int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1748 const u8 *oobbuf, int start, int nbytes)
1749{
1750 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1751 mtd_ooblayout_ecc);
1752}
1753EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1754
1755/**
1756 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1757 * @mtd: mtd info structure
1758 * @eccbuf: source buffer to get ECC bytes from
1759 * @oobbuf: OOB buffer
1760 * @start: first ECC byte to set
1761 * @nbytes: number of ECC bytes to set
1762 *
1763 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1764 *
1765 * Returns zero on success, a negative error code otherwise.
1766 */
1767int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1768 u8 *oobbuf, int start, int nbytes)
1769{
1770 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1771 mtd_ooblayout_ecc);
1772}
1773EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1774
1775/**
1776 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1777 * @mtd: mtd info structure
1778 * @databuf: destination buffer to store ECC bytes
1779 * @oobbuf: OOB buffer
1780 * @start: first ECC byte to retrieve
1781 * @nbytes: number of ECC bytes to retrieve
1782 *
1783 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1784 *
1785 * Returns zero on success, a negative error code otherwise.
1786 */
1787int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1788 const u8 *oobbuf, int start, int nbytes)
1789{
1790 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1791 mtd_ooblayout_free);
1792}
1793EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1794
1795/**
1796 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1797 * @mtd: mtd info structure
1798 * @databuf: source buffer to get data bytes from
1799 * @oobbuf: OOB buffer
1800 * @start: first ECC byte to set
1801 * @nbytes: number of ECC bytes to set
1802 *
1803 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
1804 *
1805 * Returns zero on success, a negative error code otherwise.
1806 */
1807int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1808 u8 *oobbuf, int start, int nbytes)
1809{
1810 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1811 mtd_ooblayout_free);
1812}
1813EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1814
1815/**
1816 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1817 * @mtd: mtd info structure
1818 *
1819 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1820 *
1821 * Returns zero on success, a negative error code otherwise.
1822 */
1823int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1824{
1825 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1826}
1827EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1828
1829/**
1830 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1831 * @mtd: mtd info structure
1832 *
1833 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1834 *
1835 * Returns zero on success, a negative error code otherwise.
1836 */
1837int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1838{
1839 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1840}
1841EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1842
1843/*
1844 * Method to access the protection register area, present in some flash
1845 * devices. The user data is one time programmable but the factory data is read
1846 * only.
1847 */
1848int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1849 struct otp_info *buf)
1850{
1851 struct mtd_info *master = mtd_get_master(mtd);
1852
1853 if (!master->_get_fact_prot_info)
1854 return -EOPNOTSUPP;
1855 if (!len)
1856 return 0;
1857 return master->_get_fact_prot_info(master, len, retlen, buf);
1858}
1859EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1860
1861int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1862 size_t *retlen, u_char *buf)
1863{
1864 struct mtd_info *master = mtd_get_master(mtd);
1865
1866 *retlen = 0;
1867 if (!master->_read_fact_prot_reg)
1868 return -EOPNOTSUPP;
1869 if (!len)
1870 return 0;
1871 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
1872}
1873EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1874
1875int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1876 struct otp_info *buf)
1877{
1878 struct mtd_info *master = mtd_get_master(mtd);
1879
1880 if (!master->_get_user_prot_info)
1881 return -EOPNOTSUPP;
1882 if (!len)
1883 return 0;
1884 return master->_get_user_prot_info(master, len, retlen, buf);
1885}
1886EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1887
1888int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1889 size_t *retlen, u_char *buf)
1890{
1891 struct mtd_info *master = mtd_get_master(mtd);
1892
1893 *retlen = 0;
1894 if (!master->_read_user_prot_reg)
1895 return -EOPNOTSUPP;
1896 if (!len)
1897 return 0;
1898 return master->_read_user_prot_reg(master, from, len, retlen, buf);
1899}
1900EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1901
1902int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1903 size_t *retlen, u_char *buf)
1904{
1905 struct mtd_info *master = mtd_get_master(mtd);
1906 int ret;
1907
1908 *retlen = 0;
1909 if (!master->_write_user_prot_reg)
1910 return -EOPNOTSUPP;
1911 if (!len)
1912 return 0;
1913 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
1914 if (ret)
1915 return ret;
1916
1917 /*
1918 * If no data could be written at all, we are out of memory and
1919 * must return -ENOSPC.
1920 */
1921 return (*retlen) ? 0 : -ENOSPC;
1922}
1923EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1924
1925int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1926{
1927 struct mtd_info *master = mtd_get_master(mtd);
1928
1929 if (!master->_lock_user_prot_reg)
1930 return -EOPNOTSUPP;
1931 if (!len)
1932 return 0;
1933 return master->_lock_user_prot_reg(master, from, len);
1934}
1935EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1936
1937/* Chip-supported device locking */
1938int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1939{
1940 struct mtd_info *master = mtd_get_master(mtd);
1941
1942 if (!master->_lock)
1943 return -EOPNOTSUPP;
1944 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1945 return -EINVAL;
1946 if (!len)
1947 return 0;
1948
1949 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1950 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1951 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1952 }
1953
1954 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
1955}
1956EXPORT_SYMBOL_GPL(mtd_lock);
1957
1958int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1959{
1960 struct mtd_info *master = mtd_get_master(mtd);
1961
1962 if (!master->_unlock)
1963 return -EOPNOTSUPP;
1964 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1965 return -EINVAL;
1966 if (!len)
1967 return 0;
1968
1969 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1970 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1971 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1972 }
1973
1974 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
1975}
1976EXPORT_SYMBOL_GPL(mtd_unlock);
1977
1978int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1979{
1980 struct mtd_info *master = mtd_get_master(mtd);
1981
1982 if (!master->_is_locked)
1983 return -EOPNOTSUPP;
1984 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1985 return -EINVAL;
1986 if (!len)
1987 return 0;
1988
1989 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1990 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1991 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1992 }
1993
1994 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
1995}
1996EXPORT_SYMBOL_GPL(mtd_is_locked);
1997
1998int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1999{
2000 struct mtd_info *master = mtd_get_master(mtd);
2001
2002 if (ofs < 0 || ofs >= mtd->size)
2003 return -EINVAL;
2004 if (!master->_block_isreserved)
2005 return 0;
2006
2007 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2008 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2009
2010 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2011}
2012EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2013
2014int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2015{
2016 struct mtd_info *master = mtd_get_master(mtd);
2017
2018 if (ofs < 0 || ofs >= mtd->size)
2019 return -EINVAL;
2020 if (!master->_block_isbad)
2021 return 0;
2022
2023 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2024 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2025
2026 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2027}
2028EXPORT_SYMBOL_GPL(mtd_block_isbad);
2029
2030int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2031{
2032 struct mtd_info *master = mtd_get_master(mtd);
2033 int ret;
2034
2035 if (!master->_block_markbad)
2036 return -EOPNOTSUPP;
2037 if (ofs < 0 || ofs >= mtd->size)
2038 return -EINVAL;
2039 if (!(mtd->flags & MTD_WRITEABLE))
2040 return -EROFS;
2041
2042 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2043 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2044
2045 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2046 if (ret)
2047 return ret;
2048
2049 while (mtd->parent) {
2050 mtd->ecc_stats.badblocks++;
2051 mtd = mtd->parent;
2052 }
2053
2054 return 0;
2055}
2056EXPORT_SYMBOL_GPL(mtd_block_markbad);
2057
2058/*
2059 * default_mtd_writev - the default writev method
2060 * @mtd: mtd device description object pointer
2061 * @vecs: the vectors to write
2062 * @count: count of vectors in @vecs
2063 * @to: the MTD device offset to write to
2064 * @retlen: on exit contains the count of bytes written to the MTD device.
2065 *
2066 * This function returns zero in case of success and a negative error code in
2067 * case of failure.
2068 */
2069static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2070 unsigned long count, loff_t to, size_t *retlen)
2071{
2072 unsigned long i;
2073 size_t totlen = 0, thislen;
2074 int ret = 0;
2075
2076 for (i = 0; i < count; i++) {
2077 if (!vecs[i].iov_len)
2078 continue;
2079 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2080 vecs[i].iov_base);
2081 totlen += thislen;
2082 if (ret || thislen != vecs[i].iov_len)
2083 break;
2084 to += vecs[i].iov_len;
2085 }
2086 *retlen = totlen;
2087 return ret;
2088}
2089
2090/*
2091 * mtd_writev - the vector-based MTD write method
2092 * @mtd: mtd device description object pointer
2093 * @vecs: the vectors to write
2094 * @count: count of vectors in @vecs
2095 * @to: the MTD device offset to write to
2096 * @retlen: on exit contains the count of bytes written to the MTD device.
2097 *
2098 * This function returns zero in case of success and a negative error code in
2099 * case of failure.
2100 */
2101int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2102 unsigned long count, loff_t to, size_t *retlen)
2103{
2104 struct mtd_info *master = mtd_get_master(mtd);
2105
2106 *retlen = 0;
2107 if (!(mtd->flags & MTD_WRITEABLE))
2108 return -EROFS;
2109
2110 if (!master->_writev)
2111 return default_mtd_writev(mtd, vecs, count, to, retlen);
2112
2113 return master->_writev(master, vecs, count,
2114 mtd_get_master_ofs(mtd, to), retlen);
2115}
2116EXPORT_SYMBOL_GPL(mtd_writev);
2117
2118/**
2119 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2120 * @mtd: mtd device description object pointer
2121 * @size: a pointer to the ideal or maximum size of the allocation, points
2122 * to the actual allocation size on success.
2123 *
2124 * This routine attempts to allocate a contiguous kernel buffer up to
2125 * the specified size, backing off the size of the request exponentially
2126 * until the request succeeds or until the allocation size falls below
2127 * the system page size. This attempts to make sure it does not adversely
2128 * impact system performance, so when allocating more than one page, we
2129 * ask the memory allocator to avoid re-trying, swapping, writing back
2130 * or performing I/O.
2131 *
2132 * Note, this function also makes sure that the allocated buffer is aligned to
2133 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2134 *
2135 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2136 * to handle smaller (i.e. degraded) buffer allocations under low- or
2137 * fragmented-memory situations where such reduced allocations, from a
2138 * requested ideal, are allowed.
2139 *
2140 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2141 */
2142void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2143{
2144 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2145 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2146 void *kbuf;
2147
2148 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2149
2150 while (*size > min_alloc) {
2151 kbuf = kmalloc(*size, flags);
2152 if (kbuf)
2153 return kbuf;
2154
2155 *size >>= 1;
2156 *size = ALIGN(*size, mtd->writesize);
2157 }
2158
2159 /*
2160 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2161 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2162 */
2163 return kmalloc(*size, GFP_KERNEL);
2164}
2165EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2166
2167#ifdef CONFIG_PROC_FS
2168
2169/*====================================================================*/
2170/* Support for /proc/mtd */
2171
2172static int mtd_proc_show(struct seq_file *m, void *v)
2173{
2174 struct mtd_info *mtd;
2175
2176 seq_puts(m, "dev: size erasesize name\n");
2177 mutex_lock(&mtd_table_mutex);
2178 mtd_for_each_device(mtd) {
2179 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2180 mtd->index, (unsigned long long)mtd->size,
2181 mtd->erasesize, mtd->name);
2182 }
2183 mutex_unlock(&mtd_table_mutex);
2184 return 0;
2185}
2186#endif /* CONFIG_PROC_FS */
2187
2188/*====================================================================*/
2189/* Init code */
2190
2191static struct backing_dev_info * __init mtd_bdi_init(char *name)
2192{
2193 struct backing_dev_info *bdi;
2194 int ret;
2195
2196 bdi = bdi_alloc(NUMA_NO_NODE);
2197 if (!bdi)
2198 return ERR_PTR(-ENOMEM);
2199
2200 /*
2201 * We put '-0' suffix to the name to get the same name format as we
2202 * used to get. Since this is called only once, we get a unique name.
2203 */
2204 ret = bdi_register(bdi, "%.28s-0", name);
2205 if (ret)
2206 bdi_put(bdi);
2207
2208 return ret ? ERR_PTR(ret) : bdi;
2209}
2210
2211static struct proc_dir_entry *proc_mtd;
2212
2213static int __init init_mtd(void)
2214{
2215 int ret;
2216
2217 ret = class_register(&mtd_class);
2218 if (ret)
2219 goto err_reg;
2220
2221 mtd_bdi = mtd_bdi_init("mtd");
2222 if (IS_ERR(mtd_bdi)) {
2223 ret = PTR_ERR(mtd_bdi);
2224 goto err_bdi;
2225 }
2226
2227 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2228
2229 ret = init_mtdchar();
2230 if (ret)
2231 goto out_procfs;
2232
2233 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2234
2235 return 0;
2236
2237out_procfs:
2238 if (proc_mtd)
2239 remove_proc_entry("mtd", NULL);
2240 bdi_put(mtd_bdi);
2241err_bdi:
2242 class_unregister(&mtd_class);
2243err_reg:
2244 pr_err("Error registering mtd class or bdi: %d\n", ret);
2245 return ret;
2246}
2247
2248static void __exit cleanup_mtd(void)
2249{
2250 debugfs_remove_recursive(dfs_dir_mtd);
2251 cleanup_mtdchar();
2252 if (proc_mtd)
2253 remove_proc_entry("mtd", NULL);
2254 class_unregister(&mtd_class);
2255 bdi_put(mtd_bdi);
2256 idr_destroy(&mtd_idr);
2257}
2258
2259module_init(init_mtd);
2260module_exit(cleanup_mtd);
2261
2262MODULE_LICENSE("GPL");
2263MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2264MODULE_DESCRIPTION("Core MTD registration and access routines");