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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/*
2 * Core registration and callback routines for MTD
3 * drivers and users.
4 *
5 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
6 * Copyright © 2006 Red Hat UK Limited
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24#include <linux/module.h>
25#include <linux/kernel.h>
26#include <linux/ptrace.h>
27#include <linux/seq_file.h>
28#include <linux/string.h>
29#include <linux/timer.h>
30#include <linux/major.h>
31#include <linux/fs.h>
32#include <linux/err.h>
33#include <linux/ioctl.h>
34#include <linux/init.h>
35#include <linux/of.h>
36#include <linux/proc_fs.h>
37#include <linux/idr.h>
38#include <linux/backing-dev.h>
39#include <linux/gfp.h>
40#include <linux/slab.h>
41#include <linux/reboot.h>
42#include <linux/leds.h>
43#include <linux/debugfs.h>
44
45#include <linux/mtd/mtd.h>
46#include <linux/mtd/partitions.h>
47
48#include "mtdcore.h"
49
50struct backing_dev_info *mtd_bdi;
51
52#ifdef CONFIG_PM_SLEEP
53
54static int mtd_cls_suspend(struct device *dev)
55{
56 struct mtd_info *mtd = dev_get_drvdata(dev);
57
58 return mtd ? mtd_suspend(mtd) : 0;
59}
60
61static int mtd_cls_resume(struct device *dev)
62{
63 struct mtd_info *mtd = dev_get_drvdata(dev);
64
65 if (mtd)
66 mtd_resume(mtd);
67 return 0;
68}
69
70static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
71#define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
72#else
73#define MTD_CLS_PM_OPS NULL
74#endif
75
76static struct class mtd_class = {
77 .name = "mtd",
78 .owner = THIS_MODULE,
79 .pm = MTD_CLS_PM_OPS,
80};
81
82static DEFINE_IDR(mtd_idr);
83
84/* These are exported solely for the purpose of mtd_blkdevs.c. You
85 should not use them for _anything_ else */
86DEFINE_MUTEX(mtd_table_mutex);
87EXPORT_SYMBOL_GPL(mtd_table_mutex);
88
89struct mtd_info *__mtd_next_device(int i)
90{
91 return idr_get_next(&mtd_idr, &i);
92}
93EXPORT_SYMBOL_GPL(__mtd_next_device);
94
95static LIST_HEAD(mtd_notifiers);
96
97
98#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
99
100/* REVISIT once MTD uses the driver model better, whoever allocates
101 * the mtd_info will probably want to use the release() hook...
102 */
103static void mtd_release(struct device *dev)
104{
105 struct mtd_info *mtd = dev_get_drvdata(dev);
106 dev_t index = MTD_DEVT(mtd->index);
107
108 /* remove /dev/mtdXro node */
109 device_destroy(&mtd_class, index + 1);
110}
111
112static ssize_t mtd_type_show(struct device *dev,
113 struct device_attribute *attr, char *buf)
114{
115 struct mtd_info *mtd = dev_get_drvdata(dev);
116 char *type;
117
118 switch (mtd->type) {
119 case MTD_ABSENT:
120 type = "absent";
121 break;
122 case MTD_RAM:
123 type = "ram";
124 break;
125 case MTD_ROM:
126 type = "rom";
127 break;
128 case MTD_NORFLASH:
129 type = "nor";
130 break;
131 case MTD_NANDFLASH:
132 type = "nand";
133 break;
134 case MTD_DATAFLASH:
135 type = "dataflash";
136 break;
137 case MTD_UBIVOLUME:
138 type = "ubi";
139 break;
140 case MTD_MLCNANDFLASH:
141 type = "mlc-nand";
142 break;
143 default:
144 type = "unknown";
145 }
146
147 return snprintf(buf, PAGE_SIZE, "%s\n", type);
148}
149static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
150
151static ssize_t mtd_flags_show(struct device *dev,
152 struct device_attribute *attr, char *buf)
153{
154 struct mtd_info *mtd = dev_get_drvdata(dev);
155
156 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
157
158}
159static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
160
161static ssize_t mtd_size_show(struct device *dev,
162 struct device_attribute *attr, char *buf)
163{
164 struct mtd_info *mtd = dev_get_drvdata(dev);
165
166 return snprintf(buf, PAGE_SIZE, "%llu\n",
167 (unsigned long long)mtd->size);
168
169}
170static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
171
172static ssize_t mtd_erasesize_show(struct device *dev,
173 struct device_attribute *attr, char *buf)
174{
175 struct mtd_info *mtd = dev_get_drvdata(dev);
176
177 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
178
179}
180static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
181
182static ssize_t mtd_writesize_show(struct device *dev,
183 struct device_attribute *attr, char *buf)
184{
185 struct mtd_info *mtd = dev_get_drvdata(dev);
186
187 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
188
189}
190static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
191
192static ssize_t mtd_subpagesize_show(struct device *dev,
193 struct device_attribute *attr, char *buf)
194{
195 struct mtd_info *mtd = dev_get_drvdata(dev);
196 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
197
198 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
199
200}
201static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
202
203static ssize_t mtd_oobsize_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
205{
206 struct mtd_info *mtd = dev_get_drvdata(dev);
207
208 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
209
210}
211static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
212
213static ssize_t mtd_numeraseregions_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
215{
216 struct mtd_info *mtd = dev_get_drvdata(dev);
217
218 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
219
220}
221static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
222 NULL);
223
224static ssize_t mtd_name_show(struct device *dev,
225 struct device_attribute *attr, char *buf)
226{
227 struct mtd_info *mtd = dev_get_drvdata(dev);
228
229 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
230
231}
232static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
233
234static ssize_t mtd_ecc_strength_show(struct device *dev,
235 struct device_attribute *attr, char *buf)
236{
237 struct mtd_info *mtd = dev_get_drvdata(dev);
238
239 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
240}
241static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
242
243static ssize_t mtd_bitflip_threshold_show(struct device *dev,
244 struct device_attribute *attr,
245 char *buf)
246{
247 struct mtd_info *mtd = dev_get_drvdata(dev);
248
249 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
250}
251
252static ssize_t mtd_bitflip_threshold_store(struct device *dev,
253 struct device_attribute *attr,
254 const char *buf, size_t count)
255{
256 struct mtd_info *mtd = dev_get_drvdata(dev);
257 unsigned int bitflip_threshold;
258 int retval;
259
260 retval = kstrtouint(buf, 0, &bitflip_threshold);
261 if (retval)
262 return retval;
263
264 mtd->bitflip_threshold = bitflip_threshold;
265 return count;
266}
267static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
268 mtd_bitflip_threshold_show,
269 mtd_bitflip_threshold_store);
270
271static ssize_t mtd_ecc_step_size_show(struct device *dev,
272 struct device_attribute *attr, char *buf)
273{
274 struct mtd_info *mtd = dev_get_drvdata(dev);
275
276 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
277
278}
279static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
280
281static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
282 struct device_attribute *attr, char *buf)
283{
284 struct mtd_info *mtd = dev_get_drvdata(dev);
285 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
286
287 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
288}
289static DEVICE_ATTR(corrected_bits, S_IRUGO,
290 mtd_ecc_stats_corrected_show, NULL);
291
292static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
293 struct device_attribute *attr, char *buf)
294{
295 struct mtd_info *mtd = dev_get_drvdata(dev);
296 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
297
298 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
299}
300static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
301
302static ssize_t mtd_badblocks_show(struct device *dev,
303 struct device_attribute *attr, char *buf)
304{
305 struct mtd_info *mtd = dev_get_drvdata(dev);
306 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
307
308 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
309}
310static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
311
312static ssize_t mtd_bbtblocks_show(struct device *dev,
313 struct device_attribute *attr, char *buf)
314{
315 struct mtd_info *mtd = dev_get_drvdata(dev);
316 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
317
318 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
319}
320static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
321
322static struct attribute *mtd_attrs[] = {
323 &dev_attr_type.attr,
324 &dev_attr_flags.attr,
325 &dev_attr_size.attr,
326 &dev_attr_erasesize.attr,
327 &dev_attr_writesize.attr,
328 &dev_attr_subpagesize.attr,
329 &dev_attr_oobsize.attr,
330 &dev_attr_numeraseregions.attr,
331 &dev_attr_name.attr,
332 &dev_attr_ecc_strength.attr,
333 &dev_attr_ecc_step_size.attr,
334 &dev_attr_corrected_bits.attr,
335 &dev_attr_ecc_failures.attr,
336 &dev_attr_bad_blocks.attr,
337 &dev_attr_bbt_blocks.attr,
338 &dev_attr_bitflip_threshold.attr,
339 NULL,
340};
341ATTRIBUTE_GROUPS(mtd);
342
343static const struct device_type mtd_devtype = {
344 .name = "mtd",
345 .groups = mtd_groups,
346 .release = mtd_release,
347};
348
349#ifndef CONFIG_MMU
350unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
351{
352 switch (mtd->type) {
353 case MTD_RAM:
354 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
355 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
356 case MTD_ROM:
357 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
358 NOMMU_MAP_READ;
359 default:
360 return NOMMU_MAP_COPY;
361 }
362}
363EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
364#endif
365
366static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
367 void *cmd)
368{
369 struct mtd_info *mtd;
370
371 mtd = container_of(n, struct mtd_info, reboot_notifier);
372 mtd->_reboot(mtd);
373
374 return NOTIFY_DONE;
375}
376
377/**
378 * mtd_wunit_to_pairing_info - get pairing information of a wunit
379 * @mtd: pointer to new MTD device info structure
380 * @wunit: write unit we are interested in
381 * @info: returned pairing information
382 *
383 * Retrieve pairing information associated to the wunit.
384 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
385 * paired together, and where programming a page may influence the page it is
386 * paired with.
387 * The notion of page is replaced by the term wunit (write-unit) to stay
388 * consistent with the ->writesize field.
389 *
390 * The @wunit argument can be extracted from an absolute offset using
391 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
392 * to @wunit.
393 *
394 * From the pairing info the MTD user can find all the wunits paired with
395 * @wunit using the following loop:
396 *
397 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
398 * info.pair = i;
399 * mtd_pairing_info_to_wunit(mtd, &info);
400 * ...
401 * }
402 */
403int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
404 struct mtd_pairing_info *info)
405{
406 int npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
407
408 if (wunit < 0 || wunit >= npairs)
409 return -EINVAL;
410
411 if (mtd->pairing && mtd->pairing->get_info)
412 return mtd->pairing->get_info(mtd, wunit, info);
413
414 info->group = 0;
415 info->pair = wunit;
416
417 return 0;
418}
419EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
420
421/**
422 * mtd_pairing_info_to_wunit - get wunit from pairing information
423 * @mtd: pointer to new MTD device info structure
424 * @info: pairing information struct
425 *
426 * Returns a positive number representing the wunit associated to the info
427 * struct, or a negative error code.
428 *
429 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
430 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
431 * doc).
432 *
433 * It can also be used to only program the first page of each pair (i.e.
434 * page attached to group 0), which allows one to use an MLC NAND in
435 * software-emulated SLC mode:
436 *
437 * info.group = 0;
438 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
439 * for (info.pair = 0; info.pair < npairs; info.pair++) {
440 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
441 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
442 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
443 * }
444 */
445int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
446 const struct mtd_pairing_info *info)
447{
448 int ngroups = mtd_pairing_groups(mtd);
449 int npairs = mtd_wunit_per_eb(mtd) / ngroups;
450
451 if (!info || info->pair < 0 || info->pair >= npairs ||
452 info->group < 0 || info->group >= ngroups)
453 return -EINVAL;
454
455 if (mtd->pairing && mtd->pairing->get_wunit)
456 return mtd->pairing->get_wunit(mtd, info);
457
458 return info->pair;
459}
460EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
461
462/**
463 * mtd_pairing_groups - get the number of pairing groups
464 * @mtd: pointer to new MTD device info structure
465 *
466 * Returns the number of pairing groups.
467 *
468 * This number is usually equal to the number of bits exposed by a single
469 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
470 * to iterate over all pages of a given pair.
471 */
472int mtd_pairing_groups(struct mtd_info *mtd)
473{
474 if (!mtd->pairing || !mtd->pairing->ngroups)
475 return 1;
476
477 return mtd->pairing->ngroups;
478}
479EXPORT_SYMBOL_GPL(mtd_pairing_groups);
480
481static struct dentry *dfs_dir_mtd;
482
483/**
484 * add_mtd_device - register an MTD device
485 * @mtd: pointer to new MTD device info structure
486 *
487 * Add a device to the list of MTD devices present in the system, and
488 * notify each currently active MTD 'user' of its arrival. Returns
489 * zero on success or non-zero on failure.
490 */
491
492int add_mtd_device(struct mtd_info *mtd)
493{
494 struct mtd_notifier *not;
495 int i, error;
496
497 /*
498 * May occur, for instance, on buggy drivers which call
499 * mtd_device_parse_register() multiple times on the same master MTD,
500 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
501 */
502 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
503 return -EEXIST;
504
505 BUG_ON(mtd->writesize == 0);
506
507 if (WARN_ON((!mtd->erasesize || !mtd->_erase) &&
508 !(mtd->flags & MTD_NO_ERASE)))
509 return -EINVAL;
510
511 mutex_lock(&mtd_table_mutex);
512
513 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
514 if (i < 0) {
515 error = i;
516 goto fail_locked;
517 }
518
519 mtd->index = i;
520 mtd->usecount = 0;
521
522 /* default value if not set by driver */
523 if (mtd->bitflip_threshold == 0)
524 mtd->bitflip_threshold = mtd->ecc_strength;
525
526 if (is_power_of_2(mtd->erasesize))
527 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
528 else
529 mtd->erasesize_shift = 0;
530
531 if (is_power_of_2(mtd->writesize))
532 mtd->writesize_shift = ffs(mtd->writesize) - 1;
533 else
534 mtd->writesize_shift = 0;
535
536 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
537 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
538
539 /* Some chips always power up locked. Unlock them now */
540 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
541 error = mtd_unlock(mtd, 0, mtd->size);
542 if (error && error != -EOPNOTSUPP)
543 printk(KERN_WARNING
544 "%s: unlock failed, writes may not work\n",
545 mtd->name);
546 /* Ignore unlock failures? */
547 error = 0;
548 }
549
550 /* Caller should have set dev.parent to match the
551 * physical device, if appropriate.
552 */
553 mtd->dev.type = &mtd_devtype;
554 mtd->dev.class = &mtd_class;
555 mtd->dev.devt = MTD_DEVT(i);
556 dev_set_name(&mtd->dev, "mtd%d", i);
557 dev_set_drvdata(&mtd->dev, mtd);
558 of_node_get(mtd_get_of_node(mtd));
559 error = device_register(&mtd->dev);
560 if (error)
561 goto fail_added;
562
563 if (!IS_ERR_OR_NULL(dfs_dir_mtd)) {
564 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(&mtd->dev), dfs_dir_mtd);
565 if (IS_ERR_OR_NULL(mtd->dbg.dfs_dir)) {
566 pr_debug("mtd device %s won't show data in debugfs\n",
567 dev_name(&mtd->dev));
568 }
569 }
570
571 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
572 "mtd%dro", i);
573
574 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
575 /* No need to get a refcount on the module containing
576 the notifier, since we hold the mtd_table_mutex */
577 list_for_each_entry(not, &mtd_notifiers, list)
578 not->add(mtd);
579
580 mutex_unlock(&mtd_table_mutex);
581 /* We _know_ we aren't being removed, because
582 our caller is still holding us here. So none
583 of this try_ nonsense, and no bitching about it
584 either. :) */
585 __module_get(THIS_MODULE);
586 return 0;
587
588fail_added:
589 of_node_put(mtd_get_of_node(mtd));
590 idr_remove(&mtd_idr, i);
591fail_locked:
592 mutex_unlock(&mtd_table_mutex);
593 return error;
594}
595
596/**
597 * del_mtd_device - unregister an MTD device
598 * @mtd: pointer to MTD device info structure
599 *
600 * Remove a device from the list of MTD devices present in the system,
601 * and notify each currently active MTD 'user' of its departure.
602 * Returns zero on success or 1 on failure, which currently will happen
603 * if the requested device does not appear to be present in the list.
604 */
605
606int del_mtd_device(struct mtd_info *mtd)
607{
608 int ret;
609 struct mtd_notifier *not;
610
611 mutex_lock(&mtd_table_mutex);
612
613 debugfs_remove_recursive(mtd->dbg.dfs_dir);
614
615 if (idr_find(&mtd_idr, mtd->index) != mtd) {
616 ret = -ENODEV;
617 goto out_error;
618 }
619
620 /* No need to get a refcount on the module containing
621 the notifier, since we hold the mtd_table_mutex */
622 list_for_each_entry(not, &mtd_notifiers, list)
623 not->remove(mtd);
624
625 if (mtd->usecount) {
626 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
627 mtd->index, mtd->name, mtd->usecount);
628 ret = -EBUSY;
629 } else {
630 device_unregister(&mtd->dev);
631
632 idr_remove(&mtd_idr, mtd->index);
633 of_node_put(mtd_get_of_node(mtd));
634
635 module_put(THIS_MODULE);
636 ret = 0;
637 }
638
639out_error:
640 mutex_unlock(&mtd_table_mutex);
641 return ret;
642}
643
644/*
645 * Set a few defaults based on the parent devices, if not provided by the
646 * driver
647 */
648static void mtd_set_dev_defaults(struct mtd_info *mtd)
649{
650 if (mtd->dev.parent) {
651 if (!mtd->owner && mtd->dev.parent->driver)
652 mtd->owner = mtd->dev.parent->driver->owner;
653 if (!mtd->name)
654 mtd->name = dev_name(mtd->dev.parent);
655 } else {
656 pr_debug("mtd device won't show a device symlink in sysfs\n");
657 }
658}
659
660/**
661 * mtd_device_parse_register - parse partitions and register an MTD device.
662 *
663 * @mtd: the MTD device to register
664 * @types: the list of MTD partition probes to try, see
665 * 'parse_mtd_partitions()' for more information
666 * @parser_data: MTD partition parser-specific data
667 * @parts: fallback partition information to register, if parsing fails;
668 * only valid if %nr_parts > %0
669 * @nr_parts: the number of partitions in parts, if zero then the full
670 * MTD device is registered if no partition info is found
671 *
672 * This function aggregates MTD partitions parsing (done by
673 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
674 * basically follows the most common pattern found in many MTD drivers:
675 *
676 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
677 * registered first.
678 * * Then It tries to probe partitions on MTD device @mtd using parsers
679 * specified in @types (if @types is %NULL, then the default list of parsers
680 * is used, see 'parse_mtd_partitions()' for more information). If none are
681 * found this functions tries to fallback to information specified in
682 * @parts/@nr_parts.
683 * * If no partitions were found this function just registers the MTD device
684 * @mtd and exits.
685 *
686 * Returns zero in case of success and a negative error code in case of failure.
687 */
688int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
689 struct mtd_part_parser_data *parser_data,
690 const struct mtd_partition *parts,
691 int nr_parts)
692{
693 struct mtd_partitions parsed = { };
694 int ret;
695
696 mtd_set_dev_defaults(mtd);
697
698 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
699 ret = add_mtd_device(mtd);
700 if (ret)
701 return ret;
702 }
703
704 /* Prefer parsed partitions over driver-provided fallback */
705 ret = parse_mtd_partitions(mtd, types, &parsed, parser_data);
706 if (!ret && parsed.nr_parts) {
707 parts = parsed.parts;
708 nr_parts = parsed.nr_parts;
709 }
710
711 if (nr_parts)
712 ret = add_mtd_partitions(mtd, parts, nr_parts);
713 else if (!device_is_registered(&mtd->dev))
714 ret = add_mtd_device(mtd);
715 else
716 ret = 0;
717
718 if (ret)
719 goto out;
720
721 /*
722 * FIXME: some drivers unfortunately call this function more than once.
723 * So we have to check if we've already assigned the reboot notifier.
724 *
725 * Generally, we can make multiple calls work for most cases, but it
726 * does cause problems with parse_mtd_partitions() above (e.g.,
727 * cmdlineparts will register partitions more than once).
728 */
729 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
730 "MTD already registered\n");
731 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
732 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
733 register_reboot_notifier(&mtd->reboot_notifier);
734 }
735
736out:
737 /* Cleanup any parsed partitions */
738 mtd_part_parser_cleanup(&parsed);
739 if (ret && device_is_registered(&mtd->dev))
740 del_mtd_device(mtd);
741
742 return ret;
743}
744EXPORT_SYMBOL_GPL(mtd_device_parse_register);
745
746/**
747 * mtd_device_unregister - unregister an existing MTD device.
748 *
749 * @master: the MTD device to unregister. This will unregister both the master
750 * and any partitions if registered.
751 */
752int mtd_device_unregister(struct mtd_info *master)
753{
754 int err;
755
756 if (master->_reboot)
757 unregister_reboot_notifier(&master->reboot_notifier);
758
759 err = del_mtd_partitions(master);
760 if (err)
761 return err;
762
763 if (!device_is_registered(&master->dev))
764 return 0;
765
766 return del_mtd_device(master);
767}
768EXPORT_SYMBOL_GPL(mtd_device_unregister);
769
770/**
771 * register_mtd_user - register a 'user' of MTD devices.
772 * @new: pointer to notifier info structure
773 *
774 * Registers a pair of callbacks function to be called upon addition
775 * or removal of MTD devices. Causes the 'add' callback to be immediately
776 * invoked for each MTD device currently present in the system.
777 */
778void register_mtd_user (struct mtd_notifier *new)
779{
780 struct mtd_info *mtd;
781
782 mutex_lock(&mtd_table_mutex);
783
784 list_add(&new->list, &mtd_notifiers);
785
786 __module_get(THIS_MODULE);
787
788 mtd_for_each_device(mtd)
789 new->add(mtd);
790
791 mutex_unlock(&mtd_table_mutex);
792}
793EXPORT_SYMBOL_GPL(register_mtd_user);
794
795/**
796 * unregister_mtd_user - unregister a 'user' of MTD devices.
797 * @old: pointer to notifier info structure
798 *
799 * Removes a callback function pair from the list of 'users' to be
800 * notified upon addition or removal of MTD devices. Causes the
801 * 'remove' callback to be immediately invoked for each MTD device
802 * currently present in the system.
803 */
804int unregister_mtd_user (struct mtd_notifier *old)
805{
806 struct mtd_info *mtd;
807
808 mutex_lock(&mtd_table_mutex);
809
810 module_put(THIS_MODULE);
811
812 mtd_for_each_device(mtd)
813 old->remove(mtd);
814
815 list_del(&old->list);
816 mutex_unlock(&mtd_table_mutex);
817 return 0;
818}
819EXPORT_SYMBOL_GPL(unregister_mtd_user);
820
821/**
822 * get_mtd_device - obtain a validated handle for an MTD device
823 * @mtd: last known address of the required MTD device
824 * @num: internal device number of the required MTD device
825 *
826 * Given a number and NULL address, return the num'th entry in the device
827 * table, if any. Given an address and num == -1, search the device table
828 * for a device with that address and return if it's still present. Given
829 * both, return the num'th driver only if its address matches. Return
830 * error code if not.
831 */
832struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
833{
834 struct mtd_info *ret = NULL, *other;
835 int err = -ENODEV;
836
837 mutex_lock(&mtd_table_mutex);
838
839 if (num == -1) {
840 mtd_for_each_device(other) {
841 if (other == mtd) {
842 ret = mtd;
843 break;
844 }
845 }
846 } else if (num >= 0) {
847 ret = idr_find(&mtd_idr, num);
848 if (mtd && mtd != ret)
849 ret = NULL;
850 }
851
852 if (!ret) {
853 ret = ERR_PTR(err);
854 goto out;
855 }
856
857 err = __get_mtd_device(ret);
858 if (err)
859 ret = ERR_PTR(err);
860out:
861 mutex_unlock(&mtd_table_mutex);
862 return ret;
863}
864EXPORT_SYMBOL_GPL(get_mtd_device);
865
866
867int __get_mtd_device(struct mtd_info *mtd)
868{
869 int err;
870
871 if (!try_module_get(mtd->owner))
872 return -ENODEV;
873
874 if (mtd->_get_device) {
875 err = mtd->_get_device(mtd);
876
877 if (err) {
878 module_put(mtd->owner);
879 return err;
880 }
881 }
882 mtd->usecount++;
883 return 0;
884}
885EXPORT_SYMBOL_GPL(__get_mtd_device);
886
887/**
888 * get_mtd_device_nm - obtain a validated handle for an MTD device by
889 * device name
890 * @name: MTD device name to open
891 *
892 * This function returns MTD device description structure in case of
893 * success and an error code in case of failure.
894 */
895struct mtd_info *get_mtd_device_nm(const char *name)
896{
897 int err = -ENODEV;
898 struct mtd_info *mtd = NULL, *other;
899
900 mutex_lock(&mtd_table_mutex);
901
902 mtd_for_each_device(other) {
903 if (!strcmp(name, other->name)) {
904 mtd = other;
905 break;
906 }
907 }
908
909 if (!mtd)
910 goto out_unlock;
911
912 err = __get_mtd_device(mtd);
913 if (err)
914 goto out_unlock;
915
916 mutex_unlock(&mtd_table_mutex);
917 return mtd;
918
919out_unlock:
920 mutex_unlock(&mtd_table_mutex);
921 return ERR_PTR(err);
922}
923EXPORT_SYMBOL_GPL(get_mtd_device_nm);
924
925void put_mtd_device(struct mtd_info *mtd)
926{
927 mutex_lock(&mtd_table_mutex);
928 __put_mtd_device(mtd);
929 mutex_unlock(&mtd_table_mutex);
930
931}
932EXPORT_SYMBOL_GPL(put_mtd_device);
933
934void __put_mtd_device(struct mtd_info *mtd)
935{
936 --mtd->usecount;
937 BUG_ON(mtd->usecount < 0);
938
939 if (mtd->_put_device)
940 mtd->_put_device(mtd);
941
942 module_put(mtd->owner);
943}
944EXPORT_SYMBOL_GPL(__put_mtd_device);
945
946/*
947 * Erase is an synchronous operation. Device drivers are epected to return a
948 * negative error code if the operation failed and update instr->fail_addr
949 * to point the portion that was not properly erased.
950 */
951int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
952{
953 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
954
955 if (!mtd->erasesize || !mtd->_erase)
956 return -ENOTSUPP;
957
958 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
959 return -EINVAL;
960 if (!(mtd->flags & MTD_WRITEABLE))
961 return -EROFS;
962
963 if (!instr->len)
964 return 0;
965
966 ledtrig_mtd_activity();
967 return mtd->_erase(mtd, instr);
968}
969EXPORT_SYMBOL_GPL(mtd_erase);
970
971/*
972 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
973 */
974int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
975 void **virt, resource_size_t *phys)
976{
977 *retlen = 0;
978 *virt = NULL;
979 if (phys)
980 *phys = 0;
981 if (!mtd->_point)
982 return -EOPNOTSUPP;
983 if (from < 0 || from >= mtd->size || len > mtd->size - from)
984 return -EINVAL;
985 if (!len)
986 return 0;
987 return mtd->_point(mtd, from, len, retlen, virt, phys);
988}
989EXPORT_SYMBOL_GPL(mtd_point);
990
991/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
992int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
993{
994 if (!mtd->_unpoint)
995 return -EOPNOTSUPP;
996 if (from < 0 || from >= mtd->size || len > mtd->size - from)
997 return -EINVAL;
998 if (!len)
999 return 0;
1000 return mtd->_unpoint(mtd, from, len);
1001}
1002EXPORT_SYMBOL_GPL(mtd_unpoint);
1003
1004/*
1005 * Allow NOMMU mmap() to directly map the device (if not NULL)
1006 * - return the address to which the offset maps
1007 * - return -ENOSYS to indicate refusal to do the mapping
1008 */
1009unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1010 unsigned long offset, unsigned long flags)
1011{
1012 size_t retlen;
1013 void *virt;
1014 int ret;
1015
1016 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1017 if (ret)
1018 return ret;
1019 if (retlen != len) {
1020 mtd_unpoint(mtd, offset, retlen);
1021 return -ENOSYS;
1022 }
1023 return (unsigned long)virt;
1024}
1025EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1026
1027int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1028 u_char *buf)
1029{
1030 int ret_code;
1031 *retlen = 0;
1032 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1033 return -EINVAL;
1034 if (!len)
1035 return 0;
1036
1037 ledtrig_mtd_activity();
1038 /*
1039 * In the absence of an error, drivers return a non-negative integer
1040 * representing the maximum number of bitflips that were corrected on
1041 * any one ecc region (if applicable; zero otherwise).
1042 */
1043 if (mtd->_read) {
1044 ret_code = mtd->_read(mtd, from, len, retlen, buf);
1045 } else if (mtd->_read_oob) {
1046 struct mtd_oob_ops ops = {
1047 .len = len,
1048 .datbuf = buf,
1049 };
1050
1051 ret_code = mtd->_read_oob(mtd, from, &ops);
1052 *retlen = ops.retlen;
1053 } else {
1054 return -ENOTSUPP;
1055 }
1056
1057 if (unlikely(ret_code < 0))
1058 return ret_code;
1059 if (mtd->ecc_strength == 0)
1060 return 0; /* device lacks ecc */
1061 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1062}
1063EXPORT_SYMBOL_GPL(mtd_read);
1064
1065int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1066 const u_char *buf)
1067{
1068 *retlen = 0;
1069 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1070 return -EINVAL;
1071 if ((!mtd->_write && !mtd->_write_oob) ||
1072 !(mtd->flags & MTD_WRITEABLE))
1073 return -EROFS;
1074 if (!len)
1075 return 0;
1076 ledtrig_mtd_activity();
1077
1078 if (!mtd->_write) {
1079 struct mtd_oob_ops ops = {
1080 .len = len,
1081 .datbuf = (u8 *)buf,
1082 };
1083 int ret;
1084
1085 ret = mtd->_write_oob(mtd, to, &ops);
1086 *retlen = ops.retlen;
1087 return ret;
1088 }
1089
1090 return mtd->_write(mtd, to, len, retlen, buf);
1091}
1092EXPORT_SYMBOL_GPL(mtd_write);
1093
1094/*
1095 * In blackbox flight recorder like scenarios we want to make successful writes
1096 * in interrupt context. panic_write() is only intended to be called when its
1097 * known the kernel is about to panic and we need the write to succeed. Since
1098 * the kernel is not going to be running for much longer, this function can
1099 * break locks and delay to ensure the write succeeds (but not sleep).
1100 */
1101int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1102 const u_char *buf)
1103{
1104 *retlen = 0;
1105 if (!mtd->_panic_write)
1106 return -EOPNOTSUPP;
1107 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1108 return -EINVAL;
1109 if (!(mtd->flags & MTD_WRITEABLE))
1110 return -EROFS;
1111 if (!len)
1112 return 0;
1113 return mtd->_panic_write(mtd, to, len, retlen, buf);
1114}
1115EXPORT_SYMBOL_GPL(mtd_panic_write);
1116
1117static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1118 struct mtd_oob_ops *ops)
1119{
1120 /*
1121 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1122 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1123 * this case.
1124 */
1125 if (!ops->datbuf)
1126 ops->len = 0;
1127
1128 if (!ops->oobbuf)
1129 ops->ooblen = 0;
1130
1131 if (offs < 0 || offs + ops->len > mtd->size)
1132 return -EINVAL;
1133
1134 if (ops->ooblen) {
1135 u64 maxooblen;
1136
1137 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1138 return -EINVAL;
1139
1140 maxooblen = ((mtd_div_by_ws(mtd->size, mtd) -
1141 mtd_div_by_ws(offs, mtd)) *
1142 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1143 if (ops->ooblen > maxooblen)
1144 return -EINVAL;
1145 }
1146
1147 return 0;
1148}
1149
1150int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1151{
1152 int ret_code;
1153 ops->retlen = ops->oobretlen = 0;
1154 if (!mtd->_read_oob)
1155 return -EOPNOTSUPP;
1156
1157 ret_code = mtd_check_oob_ops(mtd, from, ops);
1158 if (ret_code)
1159 return ret_code;
1160
1161 ledtrig_mtd_activity();
1162 /*
1163 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1164 * similar to mtd->_read(), returning a non-negative integer
1165 * representing max bitflips. In other cases, mtd->_read_oob() may
1166 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1167 */
1168 ret_code = mtd->_read_oob(mtd, from, ops);
1169 if (unlikely(ret_code < 0))
1170 return ret_code;
1171 if (mtd->ecc_strength == 0)
1172 return 0; /* device lacks ecc */
1173 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1174}
1175EXPORT_SYMBOL_GPL(mtd_read_oob);
1176
1177int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1178 struct mtd_oob_ops *ops)
1179{
1180 int ret;
1181
1182 ops->retlen = ops->oobretlen = 0;
1183 if (!mtd->_write_oob)
1184 return -EOPNOTSUPP;
1185 if (!(mtd->flags & MTD_WRITEABLE))
1186 return -EROFS;
1187
1188 ret = mtd_check_oob_ops(mtd, to, ops);
1189 if (ret)
1190 return ret;
1191
1192 ledtrig_mtd_activity();
1193 return mtd->_write_oob(mtd, to, ops);
1194}
1195EXPORT_SYMBOL_GPL(mtd_write_oob);
1196
1197/**
1198 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1199 * @mtd: MTD device structure
1200 * @section: ECC section. Depending on the layout you may have all the ECC
1201 * bytes stored in a single contiguous section, or one section
1202 * per ECC chunk (and sometime several sections for a single ECC
1203 * ECC chunk)
1204 * @oobecc: OOB region struct filled with the appropriate ECC position
1205 * information
1206 *
1207 * This function returns ECC section information in the OOB area. If you want
1208 * to get all the ECC bytes information, then you should call
1209 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1210 *
1211 * Returns zero on success, a negative error code otherwise.
1212 */
1213int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1214 struct mtd_oob_region *oobecc)
1215{
1216 memset(oobecc, 0, sizeof(*oobecc));
1217
1218 if (!mtd || section < 0)
1219 return -EINVAL;
1220
1221 if (!mtd->ooblayout || !mtd->ooblayout->ecc)
1222 return -ENOTSUPP;
1223
1224 return mtd->ooblayout->ecc(mtd, section, oobecc);
1225}
1226EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1227
1228/**
1229 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1230 * section
1231 * @mtd: MTD device structure
1232 * @section: Free section you are interested in. Depending on the layout
1233 * you may have all the free bytes stored in a single contiguous
1234 * section, or one section per ECC chunk plus an extra section
1235 * for the remaining bytes (or other funky layout).
1236 * @oobfree: OOB region struct filled with the appropriate free position
1237 * information
1238 *
1239 * This function returns free bytes position in the OOB area. If you want
1240 * to get all the free bytes information, then you should call
1241 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1242 *
1243 * Returns zero on success, a negative error code otherwise.
1244 */
1245int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1246 struct mtd_oob_region *oobfree)
1247{
1248 memset(oobfree, 0, sizeof(*oobfree));
1249
1250 if (!mtd || section < 0)
1251 return -EINVAL;
1252
1253 if (!mtd->ooblayout || !mtd->ooblayout->free)
1254 return -ENOTSUPP;
1255
1256 return mtd->ooblayout->free(mtd, section, oobfree);
1257}
1258EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1259
1260/**
1261 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1262 * @mtd: mtd info structure
1263 * @byte: the byte we are searching for
1264 * @sectionp: pointer where the section id will be stored
1265 * @oobregion: used to retrieve the ECC position
1266 * @iter: iterator function. Should be either mtd_ooblayout_free or
1267 * mtd_ooblayout_ecc depending on the region type you're searching for
1268 *
1269 * This function returns the section id and oobregion information of a
1270 * specific byte. For example, say you want to know where the 4th ECC byte is
1271 * stored, you'll use:
1272 *
1273 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1274 *
1275 * Returns zero on success, a negative error code otherwise.
1276 */
1277static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1278 int *sectionp, struct mtd_oob_region *oobregion,
1279 int (*iter)(struct mtd_info *,
1280 int section,
1281 struct mtd_oob_region *oobregion))
1282{
1283 int pos = 0, ret, section = 0;
1284
1285 memset(oobregion, 0, sizeof(*oobregion));
1286
1287 while (1) {
1288 ret = iter(mtd, section, oobregion);
1289 if (ret)
1290 return ret;
1291
1292 if (pos + oobregion->length > byte)
1293 break;
1294
1295 pos += oobregion->length;
1296 section++;
1297 }
1298
1299 /*
1300 * Adjust region info to make it start at the beginning at the
1301 * 'start' ECC byte.
1302 */
1303 oobregion->offset += byte - pos;
1304 oobregion->length -= byte - pos;
1305 *sectionp = section;
1306
1307 return 0;
1308}
1309
1310/**
1311 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1312 * ECC byte
1313 * @mtd: mtd info structure
1314 * @eccbyte: the byte we are searching for
1315 * @sectionp: pointer where the section id will be stored
1316 * @oobregion: OOB region information
1317 *
1318 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1319 * byte.
1320 *
1321 * Returns zero on success, a negative error code otherwise.
1322 */
1323int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1324 int *section,
1325 struct mtd_oob_region *oobregion)
1326{
1327 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1328 mtd_ooblayout_ecc);
1329}
1330EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1331
1332/**
1333 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1334 * @mtd: mtd info structure
1335 * @buf: destination buffer to store OOB bytes
1336 * @oobbuf: OOB buffer
1337 * @start: first byte to retrieve
1338 * @nbytes: number of bytes to retrieve
1339 * @iter: section iterator
1340 *
1341 * Extract bytes attached to a specific category (ECC or free)
1342 * from the OOB buffer and copy them into buf.
1343 *
1344 * Returns zero on success, a negative error code otherwise.
1345 */
1346static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1347 const u8 *oobbuf, int start, int nbytes,
1348 int (*iter)(struct mtd_info *,
1349 int section,
1350 struct mtd_oob_region *oobregion))
1351{
1352 struct mtd_oob_region oobregion;
1353 int section, ret;
1354
1355 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1356 &oobregion, iter);
1357
1358 while (!ret) {
1359 int cnt;
1360
1361 cnt = min_t(int, nbytes, oobregion.length);
1362 memcpy(buf, oobbuf + oobregion.offset, cnt);
1363 buf += cnt;
1364 nbytes -= cnt;
1365
1366 if (!nbytes)
1367 break;
1368
1369 ret = iter(mtd, ++section, &oobregion);
1370 }
1371
1372 return ret;
1373}
1374
1375/**
1376 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1377 * @mtd: mtd info structure
1378 * @buf: source buffer to get OOB bytes from
1379 * @oobbuf: OOB buffer
1380 * @start: first OOB byte to set
1381 * @nbytes: number of OOB bytes to set
1382 * @iter: section iterator
1383 *
1384 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1385 * is selected by passing the appropriate iterator.
1386 *
1387 * Returns zero on success, a negative error code otherwise.
1388 */
1389static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1390 u8 *oobbuf, int start, int nbytes,
1391 int (*iter)(struct mtd_info *,
1392 int section,
1393 struct mtd_oob_region *oobregion))
1394{
1395 struct mtd_oob_region oobregion;
1396 int section, ret;
1397
1398 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1399 &oobregion, iter);
1400
1401 while (!ret) {
1402 int cnt;
1403
1404 cnt = min_t(int, nbytes, oobregion.length);
1405 memcpy(oobbuf + oobregion.offset, buf, cnt);
1406 buf += cnt;
1407 nbytes -= cnt;
1408
1409 if (!nbytes)
1410 break;
1411
1412 ret = iter(mtd, ++section, &oobregion);
1413 }
1414
1415 return ret;
1416}
1417
1418/**
1419 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1420 * @mtd: mtd info structure
1421 * @iter: category iterator
1422 *
1423 * Count the number of bytes in a given category.
1424 *
1425 * Returns a positive value on success, a negative error code otherwise.
1426 */
1427static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1428 int (*iter)(struct mtd_info *,
1429 int section,
1430 struct mtd_oob_region *oobregion))
1431{
1432 struct mtd_oob_region oobregion;
1433 int section = 0, ret, nbytes = 0;
1434
1435 while (1) {
1436 ret = iter(mtd, section++, &oobregion);
1437 if (ret) {
1438 if (ret == -ERANGE)
1439 ret = nbytes;
1440 break;
1441 }
1442
1443 nbytes += oobregion.length;
1444 }
1445
1446 return ret;
1447}
1448
1449/**
1450 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1451 * @mtd: mtd info structure
1452 * @eccbuf: destination buffer to store ECC bytes
1453 * @oobbuf: OOB buffer
1454 * @start: first ECC byte to retrieve
1455 * @nbytes: number of ECC bytes to retrieve
1456 *
1457 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1458 *
1459 * Returns zero on success, a negative error code otherwise.
1460 */
1461int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1462 const u8 *oobbuf, int start, int nbytes)
1463{
1464 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1465 mtd_ooblayout_ecc);
1466}
1467EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1468
1469/**
1470 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1471 * @mtd: mtd info structure
1472 * @eccbuf: source buffer to get ECC bytes from
1473 * @oobbuf: OOB buffer
1474 * @start: first ECC byte to set
1475 * @nbytes: number of ECC bytes to set
1476 *
1477 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1478 *
1479 * Returns zero on success, a negative error code otherwise.
1480 */
1481int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1482 u8 *oobbuf, int start, int nbytes)
1483{
1484 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1485 mtd_ooblayout_ecc);
1486}
1487EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1488
1489/**
1490 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1491 * @mtd: mtd info structure
1492 * @databuf: destination buffer to store ECC bytes
1493 * @oobbuf: OOB buffer
1494 * @start: first ECC byte to retrieve
1495 * @nbytes: number of ECC bytes to retrieve
1496 *
1497 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1498 *
1499 * Returns zero on success, a negative error code otherwise.
1500 */
1501int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1502 const u8 *oobbuf, int start, int nbytes)
1503{
1504 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1505 mtd_ooblayout_free);
1506}
1507EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1508
1509/**
1510 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1511 * @mtd: mtd info structure
1512 * @databuf: source buffer to get data bytes from
1513 * @oobbuf: OOB buffer
1514 * @start: first ECC byte to set
1515 * @nbytes: number of ECC bytes to set
1516 *
1517 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1518 *
1519 * Returns zero on success, a negative error code otherwise.
1520 */
1521int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1522 u8 *oobbuf, int start, int nbytes)
1523{
1524 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1525 mtd_ooblayout_free);
1526}
1527EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1528
1529/**
1530 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1531 * @mtd: mtd info structure
1532 *
1533 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1534 *
1535 * Returns zero on success, a negative error code otherwise.
1536 */
1537int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1538{
1539 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1540}
1541EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1542
1543/**
1544 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1545 * @mtd: mtd info structure
1546 *
1547 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1548 *
1549 * Returns zero on success, a negative error code otherwise.
1550 */
1551int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1552{
1553 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1554}
1555EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1556
1557/*
1558 * Method to access the protection register area, present in some flash
1559 * devices. The user data is one time programmable but the factory data is read
1560 * only.
1561 */
1562int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1563 struct otp_info *buf)
1564{
1565 if (!mtd->_get_fact_prot_info)
1566 return -EOPNOTSUPP;
1567 if (!len)
1568 return 0;
1569 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
1570}
1571EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1572
1573int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1574 size_t *retlen, u_char *buf)
1575{
1576 *retlen = 0;
1577 if (!mtd->_read_fact_prot_reg)
1578 return -EOPNOTSUPP;
1579 if (!len)
1580 return 0;
1581 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
1582}
1583EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1584
1585int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1586 struct otp_info *buf)
1587{
1588 if (!mtd->_get_user_prot_info)
1589 return -EOPNOTSUPP;
1590 if (!len)
1591 return 0;
1592 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
1593}
1594EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1595
1596int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1597 size_t *retlen, u_char *buf)
1598{
1599 *retlen = 0;
1600 if (!mtd->_read_user_prot_reg)
1601 return -EOPNOTSUPP;
1602 if (!len)
1603 return 0;
1604 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
1605}
1606EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1607
1608int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1609 size_t *retlen, u_char *buf)
1610{
1611 int ret;
1612
1613 *retlen = 0;
1614 if (!mtd->_write_user_prot_reg)
1615 return -EOPNOTSUPP;
1616 if (!len)
1617 return 0;
1618 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
1619 if (ret)
1620 return ret;
1621
1622 /*
1623 * If no data could be written at all, we are out of memory and
1624 * must return -ENOSPC.
1625 */
1626 return (*retlen) ? 0 : -ENOSPC;
1627}
1628EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1629
1630int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1631{
1632 if (!mtd->_lock_user_prot_reg)
1633 return -EOPNOTSUPP;
1634 if (!len)
1635 return 0;
1636 return mtd->_lock_user_prot_reg(mtd, from, len);
1637}
1638EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1639
1640/* Chip-supported device locking */
1641int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1642{
1643 if (!mtd->_lock)
1644 return -EOPNOTSUPP;
1645 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1646 return -EINVAL;
1647 if (!len)
1648 return 0;
1649 return mtd->_lock(mtd, ofs, len);
1650}
1651EXPORT_SYMBOL_GPL(mtd_lock);
1652
1653int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1654{
1655 if (!mtd->_unlock)
1656 return -EOPNOTSUPP;
1657 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1658 return -EINVAL;
1659 if (!len)
1660 return 0;
1661 return mtd->_unlock(mtd, ofs, len);
1662}
1663EXPORT_SYMBOL_GPL(mtd_unlock);
1664
1665int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1666{
1667 if (!mtd->_is_locked)
1668 return -EOPNOTSUPP;
1669 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1670 return -EINVAL;
1671 if (!len)
1672 return 0;
1673 return mtd->_is_locked(mtd, ofs, len);
1674}
1675EXPORT_SYMBOL_GPL(mtd_is_locked);
1676
1677int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1678{
1679 if (ofs < 0 || ofs >= mtd->size)
1680 return -EINVAL;
1681 if (!mtd->_block_isreserved)
1682 return 0;
1683 return mtd->_block_isreserved(mtd, ofs);
1684}
1685EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1686
1687int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1688{
1689 if (ofs < 0 || ofs >= mtd->size)
1690 return -EINVAL;
1691 if (!mtd->_block_isbad)
1692 return 0;
1693 return mtd->_block_isbad(mtd, ofs);
1694}
1695EXPORT_SYMBOL_GPL(mtd_block_isbad);
1696
1697int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1698{
1699 if (!mtd->_block_markbad)
1700 return -EOPNOTSUPP;
1701 if (ofs < 0 || ofs >= mtd->size)
1702 return -EINVAL;
1703 if (!(mtd->flags & MTD_WRITEABLE))
1704 return -EROFS;
1705 return mtd->_block_markbad(mtd, ofs);
1706}
1707EXPORT_SYMBOL_GPL(mtd_block_markbad);
1708
1709/*
1710 * default_mtd_writev - the default writev method
1711 * @mtd: mtd device description object pointer
1712 * @vecs: the vectors to write
1713 * @count: count of vectors in @vecs
1714 * @to: the MTD device offset to write to
1715 * @retlen: on exit contains the count of bytes written to the MTD device.
1716 *
1717 * This function returns zero in case of success and a negative error code in
1718 * case of failure.
1719 */
1720static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1721 unsigned long count, loff_t to, size_t *retlen)
1722{
1723 unsigned long i;
1724 size_t totlen = 0, thislen;
1725 int ret = 0;
1726
1727 for (i = 0; i < count; i++) {
1728 if (!vecs[i].iov_len)
1729 continue;
1730 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1731 vecs[i].iov_base);
1732 totlen += thislen;
1733 if (ret || thislen != vecs[i].iov_len)
1734 break;
1735 to += vecs[i].iov_len;
1736 }
1737 *retlen = totlen;
1738 return ret;
1739}
1740
1741/*
1742 * mtd_writev - the vector-based MTD write method
1743 * @mtd: mtd device description object pointer
1744 * @vecs: the vectors to write
1745 * @count: count of vectors in @vecs
1746 * @to: the MTD device offset to write to
1747 * @retlen: on exit contains the count of bytes written to the MTD device.
1748 *
1749 * This function returns zero in case of success and a negative error code in
1750 * case of failure.
1751 */
1752int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1753 unsigned long count, loff_t to, size_t *retlen)
1754{
1755 *retlen = 0;
1756 if (!(mtd->flags & MTD_WRITEABLE))
1757 return -EROFS;
1758 if (!mtd->_writev)
1759 return default_mtd_writev(mtd, vecs, count, to, retlen);
1760 return mtd->_writev(mtd, vecs, count, to, retlen);
1761}
1762EXPORT_SYMBOL_GPL(mtd_writev);
1763
1764/**
1765 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1766 * @mtd: mtd device description object pointer
1767 * @size: a pointer to the ideal or maximum size of the allocation, points
1768 * to the actual allocation size on success.
1769 *
1770 * This routine attempts to allocate a contiguous kernel buffer up to
1771 * the specified size, backing off the size of the request exponentially
1772 * until the request succeeds or until the allocation size falls below
1773 * the system page size. This attempts to make sure it does not adversely
1774 * impact system performance, so when allocating more than one page, we
1775 * ask the memory allocator to avoid re-trying, swapping, writing back
1776 * or performing I/O.
1777 *
1778 * Note, this function also makes sure that the allocated buffer is aligned to
1779 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1780 *
1781 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1782 * to handle smaller (i.e. degraded) buffer allocations under low- or
1783 * fragmented-memory situations where such reduced allocations, from a
1784 * requested ideal, are allowed.
1785 *
1786 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1787 */
1788void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1789{
1790 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
1791 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1792 void *kbuf;
1793
1794 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1795
1796 while (*size > min_alloc) {
1797 kbuf = kmalloc(*size, flags);
1798 if (kbuf)
1799 return kbuf;
1800
1801 *size >>= 1;
1802 *size = ALIGN(*size, mtd->writesize);
1803 }
1804
1805 /*
1806 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1807 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1808 */
1809 return kmalloc(*size, GFP_KERNEL);
1810}
1811EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1812
1813#ifdef CONFIG_PROC_FS
1814
1815/*====================================================================*/
1816/* Support for /proc/mtd */
1817
1818static int mtd_proc_show(struct seq_file *m, void *v)
1819{
1820 struct mtd_info *mtd;
1821
1822 seq_puts(m, "dev: size erasesize name\n");
1823 mutex_lock(&mtd_table_mutex);
1824 mtd_for_each_device(mtd) {
1825 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1826 mtd->index, (unsigned long long)mtd->size,
1827 mtd->erasesize, mtd->name);
1828 }
1829 mutex_unlock(&mtd_table_mutex);
1830 return 0;
1831}
1832
1833static int mtd_proc_open(struct inode *inode, struct file *file)
1834{
1835 return single_open(file, mtd_proc_show, NULL);
1836}
1837
1838static const struct file_operations mtd_proc_ops = {
1839 .open = mtd_proc_open,
1840 .read = seq_read,
1841 .llseek = seq_lseek,
1842 .release = single_release,
1843};
1844#endif /* CONFIG_PROC_FS */
1845
1846/*====================================================================*/
1847/* Init code */
1848
1849static struct backing_dev_info * __init mtd_bdi_init(char *name)
1850{
1851 struct backing_dev_info *bdi;
1852 int ret;
1853
1854 bdi = bdi_alloc(GFP_KERNEL);
1855 if (!bdi)
1856 return ERR_PTR(-ENOMEM);
1857
1858 bdi->name = name;
1859 /*
1860 * We put '-0' suffix to the name to get the same name format as we
1861 * used to get. Since this is called only once, we get a unique name.
1862 */
1863 ret = bdi_register(bdi, "%.28s-0", name);
1864 if (ret)
1865 bdi_put(bdi);
1866
1867 return ret ? ERR_PTR(ret) : bdi;
1868}
1869
1870static struct proc_dir_entry *proc_mtd;
1871
1872static int __init init_mtd(void)
1873{
1874 int ret;
1875
1876 ret = class_register(&mtd_class);
1877 if (ret)
1878 goto err_reg;
1879
1880 mtd_bdi = mtd_bdi_init("mtd");
1881 if (IS_ERR(mtd_bdi)) {
1882 ret = PTR_ERR(mtd_bdi);
1883 goto err_bdi;
1884 }
1885
1886 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1887
1888 ret = init_mtdchar();
1889 if (ret)
1890 goto out_procfs;
1891
1892 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
1893
1894 return 0;
1895
1896out_procfs:
1897 if (proc_mtd)
1898 remove_proc_entry("mtd", NULL);
1899 bdi_put(mtd_bdi);
1900err_bdi:
1901 class_unregister(&mtd_class);
1902err_reg:
1903 pr_err("Error registering mtd class or bdi: %d\n", ret);
1904 return ret;
1905}
1906
1907static void __exit cleanup_mtd(void)
1908{
1909 debugfs_remove_recursive(dfs_dir_mtd);
1910 cleanup_mtdchar();
1911 if (proc_mtd)
1912 remove_proc_entry("mtd", NULL);
1913 class_unregister(&mtd_class);
1914 bdi_put(mtd_bdi);
1915 idr_destroy(&mtd_idr);
1916}
1917
1918module_init(init_mtd);
1919module_exit(cleanup_mtd);
1920
1921MODULE_LICENSE("GPL");
1922MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1923MODULE_DESCRIPTION("Core MTD registration and access routines");