Loading...
1/*
2 * Core registration and callback routines for MTD
3 * drivers and users.
4 *
5 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
6 * Copyright © 2006 Red Hat UK Limited
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24#include <linux/module.h>
25#include <linux/kernel.h>
26#include <linux/ptrace.h>
27#include <linux/seq_file.h>
28#include <linux/string.h>
29#include <linux/timer.h>
30#include <linux/major.h>
31#include <linux/fs.h>
32#include <linux/err.h>
33#include <linux/ioctl.h>
34#include <linux/init.h>
35#include <linux/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/proc_fs.h>
36#include <linux/idr.h>
37#include <linux/backing-dev.h>
38#include <linux/gfp.h>
39#include <linux/slab.h>
40
41#include <linux/mtd/mtd.h>
42#include <linux/mtd/partitions.h>
43
44#include "mtdcore.h"
45
46/*
47 * backing device capabilities for non-mappable devices (such as NAND flash)
48 * - permits private mappings, copies are taken of the data
49 */
50static struct backing_dev_info mtd_bdi_unmappable = {
51 .capabilities = BDI_CAP_MAP_COPY,
52};
53
54/*
55 * backing device capabilities for R/O mappable devices (such as ROM)
56 * - permits private mappings, copies are taken of the data
57 * - permits non-writable shared mappings
58 */
59static struct backing_dev_info mtd_bdi_ro_mappable = {
60 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
61 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
62};
63
64/*
65 * backing device capabilities for writable mappable devices (such as RAM)
66 * - permits private mappings, copies are taken of the data
67 * - permits non-writable shared mappings
68 */
69static struct backing_dev_info mtd_bdi_rw_mappable = {
70 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
71 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
72 BDI_CAP_WRITE_MAP),
73};
74
75static int mtd_cls_suspend(struct device *dev, pm_message_t state);
76static int mtd_cls_resume(struct device *dev);
77
78static struct class mtd_class = {
79 .name = "mtd",
80 .owner = THIS_MODULE,
81 .suspend = mtd_cls_suspend,
82 .resume = mtd_cls_resume,
83};
84
85static DEFINE_IDR(mtd_idr);
86
87/* These are exported solely for the purpose of mtd_blkdevs.c. You
88 should not use them for _anything_ else */
89DEFINE_MUTEX(mtd_table_mutex);
90EXPORT_SYMBOL_GPL(mtd_table_mutex);
91
92struct mtd_info *__mtd_next_device(int i)
93{
94 return idr_get_next(&mtd_idr, &i);
95}
96EXPORT_SYMBOL_GPL(__mtd_next_device);
97
98static LIST_HEAD(mtd_notifiers);
99
100
101#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
102
103/* REVISIT once MTD uses the driver model better, whoever allocates
104 * the mtd_info will probably want to use the release() hook...
105 */
106static void mtd_release(struct device *dev)
107{
108 struct mtd_info __maybe_unused *mtd = dev_get_drvdata(dev);
109 dev_t index = MTD_DEVT(mtd->index);
110
111 /* remove /dev/mtdXro node if needed */
112 if (index)
113 device_destroy(&mtd_class, index + 1);
114}
115
116static int mtd_cls_suspend(struct device *dev, pm_message_t state)
117{
118 struct mtd_info *mtd = dev_get_drvdata(dev);
119
120 return mtd ? mtd_suspend(mtd) : 0;
121}
122
123static int mtd_cls_resume(struct device *dev)
124{
125 struct mtd_info *mtd = dev_get_drvdata(dev);
126
127 if (mtd)
128 mtd_resume(mtd);
129 return 0;
130}
131
132static ssize_t mtd_type_show(struct device *dev,
133 struct device_attribute *attr, char *buf)
134{
135 struct mtd_info *mtd = dev_get_drvdata(dev);
136 char *type;
137
138 switch (mtd->type) {
139 case MTD_ABSENT:
140 type = "absent";
141 break;
142 case MTD_RAM:
143 type = "ram";
144 break;
145 case MTD_ROM:
146 type = "rom";
147 break;
148 case MTD_NORFLASH:
149 type = "nor";
150 break;
151 case MTD_NANDFLASH:
152 type = "nand";
153 break;
154 case MTD_DATAFLASH:
155 type = "dataflash";
156 break;
157 case MTD_UBIVOLUME:
158 type = "ubi";
159 break;
160 case MTD_MLCNANDFLASH:
161 type = "mlc-nand";
162 break;
163 default:
164 type = "unknown";
165 }
166
167 return snprintf(buf, PAGE_SIZE, "%s\n", type);
168}
169static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
170
171static ssize_t mtd_flags_show(struct device *dev,
172 struct device_attribute *attr, char *buf)
173{
174 struct mtd_info *mtd = dev_get_drvdata(dev);
175
176 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
177
178}
179static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
180
181static ssize_t mtd_size_show(struct device *dev,
182 struct device_attribute *attr, char *buf)
183{
184 struct mtd_info *mtd = dev_get_drvdata(dev);
185
186 return snprintf(buf, PAGE_SIZE, "%llu\n",
187 (unsigned long long)mtd->size);
188
189}
190static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
191
192static ssize_t mtd_erasesize_show(struct device *dev,
193 struct device_attribute *attr, char *buf)
194{
195 struct mtd_info *mtd = dev_get_drvdata(dev);
196
197 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
198
199}
200static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
201
202static ssize_t mtd_writesize_show(struct device *dev,
203 struct device_attribute *attr, char *buf)
204{
205 struct mtd_info *mtd = dev_get_drvdata(dev);
206
207 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
208
209}
210static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
211
212static ssize_t mtd_subpagesize_show(struct device *dev,
213 struct device_attribute *attr, char *buf)
214{
215 struct mtd_info *mtd = dev_get_drvdata(dev);
216 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
217
218 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
219
220}
221static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
222
223static ssize_t mtd_oobsize_show(struct device *dev,
224 struct device_attribute *attr, char *buf)
225{
226 struct mtd_info *mtd = dev_get_drvdata(dev);
227
228 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
229
230}
231static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
232
233static ssize_t mtd_numeraseregions_show(struct device *dev,
234 struct device_attribute *attr, char *buf)
235{
236 struct mtd_info *mtd = dev_get_drvdata(dev);
237
238 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
239
240}
241static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
242 NULL);
243
244static ssize_t mtd_name_show(struct device *dev,
245 struct device_attribute *attr, char *buf)
246{
247 struct mtd_info *mtd = dev_get_drvdata(dev);
248
249 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
250
251}
252static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
253
254static ssize_t mtd_ecc_strength_show(struct device *dev,
255 struct device_attribute *attr, char *buf)
256{
257 struct mtd_info *mtd = dev_get_drvdata(dev);
258
259 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
260}
261static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
262
263static ssize_t mtd_bitflip_threshold_show(struct device *dev,
264 struct device_attribute *attr,
265 char *buf)
266{
267 struct mtd_info *mtd = dev_get_drvdata(dev);
268
269 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
270}
271
272static ssize_t mtd_bitflip_threshold_store(struct device *dev,
273 struct device_attribute *attr,
274 const char *buf, size_t count)
275{
276 struct mtd_info *mtd = dev_get_drvdata(dev);
277 unsigned int bitflip_threshold;
278 int retval;
279
280 retval = kstrtouint(buf, 0, &bitflip_threshold);
281 if (retval)
282 return retval;
283
284 mtd->bitflip_threshold = bitflip_threshold;
285 return count;
286}
287static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
288 mtd_bitflip_threshold_show,
289 mtd_bitflip_threshold_store);
290
291static ssize_t mtd_ecc_step_size_show(struct device *dev,
292 struct device_attribute *attr, char *buf)
293{
294 struct mtd_info *mtd = dev_get_drvdata(dev);
295
296 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
297
298}
299static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
300
301static struct attribute *mtd_attrs[] = {
302 &dev_attr_type.attr,
303 &dev_attr_flags.attr,
304 &dev_attr_size.attr,
305 &dev_attr_erasesize.attr,
306 &dev_attr_writesize.attr,
307 &dev_attr_subpagesize.attr,
308 &dev_attr_oobsize.attr,
309 &dev_attr_numeraseregions.attr,
310 &dev_attr_name.attr,
311 &dev_attr_ecc_strength.attr,
312 &dev_attr_ecc_step_size.attr,
313 &dev_attr_bitflip_threshold.attr,
314 NULL,
315};
316ATTRIBUTE_GROUPS(mtd);
317
318static struct device_type mtd_devtype = {
319 .name = "mtd",
320 .groups = mtd_groups,
321 .release = mtd_release,
322};
323
324/**
325 * add_mtd_device - register an MTD device
326 * @mtd: pointer to new MTD device info structure
327 *
328 * Add a device to the list of MTD devices present in the system, and
329 * notify each currently active MTD 'user' of its arrival. Returns
330 * zero on success or 1 on failure, which currently will only happen
331 * if there is insufficient memory or a sysfs error.
332 */
333
334int add_mtd_device(struct mtd_info *mtd)
335{
336 struct mtd_notifier *not;
337 int i, error;
338
339 if (!mtd->backing_dev_info) {
340 switch (mtd->type) {
341 case MTD_RAM:
342 mtd->backing_dev_info = &mtd_bdi_rw_mappable;
343 break;
344 case MTD_ROM:
345 mtd->backing_dev_info = &mtd_bdi_ro_mappable;
346 break;
347 default:
348 mtd->backing_dev_info = &mtd_bdi_unmappable;
349 break;
350 }
351 }
352
353 BUG_ON(mtd->writesize == 0);
354 mutex_lock(&mtd_table_mutex);
355
356 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
357 if (i < 0)
358 goto fail_locked;
359
360 mtd->index = i;
361 mtd->usecount = 0;
362
363 /* default value if not set by driver */
364 if (mtd->bitflip_threshold == 0)
365 mtd->bitflip_threshold = mtd->ecc_strength;
366
367 if (is_power_of_2(mtd->erasesize))
368 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
369 else
370 mtd->erasesize_shift = 0;
371
372 if (is_power_of_2(mtd->writesize))
373 mtd->writesize_shift = ffs(mtd->writesize) - 1;
374 else
375 mtd->writesize_shift = 0;
376
377 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
378 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
379
380 /* Some chips always power up locked. Unlock them now */
381 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
382 error = mtd_unlock(mtd, 0, mtd->size);
383 if (error && error != -EOPNOTSUPP)
384 printk(KERN_WARNING
385 "%s: unlock failed, writes may not work\n",
386 mtd->name);
387 }
388
389 /* Caller should have set dev.parent to match the
390 * physical device.
391 */
392 mtd->dev.type = &mtd_devtype;
393 mtd->dev.class = &mtd_class;
394 mtd->dev.devt = MTD_DEVT(i);
395 dev_set_name(&mtd->dev, "mtd%d", i);
396 dev_set_drvdata(&mtd->dev, mtd);
397 if (device_register(&mtd->dev) != 0)
398 goto fail_added;
399
400 if (MTD_DEVT(i))
401 device_create(&mtd_class, mtd->dev.parent,
402 MTD_DEVT(i) + 1,
403 NULL, "mtd%dro", i);
404
405 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
406 /* No need to get a refcount on the module containing
407 the notifier, since we hold the mtd_table_mutex */
408 list_for_each_entry(not, &mtd_notifiers, list)
409 not->add(mtd);
410
411 mutex_unlock(&mtd_table_mutex);
412 /* We _know_ we aren't being removed, because
413 our caller is still holding us here. So none
414 of this try_ nonsense, and no bitching about it
415 either. :) */
416 __module_get(THIS_MODULE);
417 return 0;
418
419fail_added:
420 idr_remove(&mtd_idr, i);
421fail_locked:
422 mutex_unlock(&mtd_table_mutex);
423 return 1;
424}
425
426/**
427 * del_mtd_device - unregister an MTD device
428 * @mtd: pointer to MTD device info structure
429 *
430 * Remove a device from the list of MTD devices present in the system,
431 * and notify each currently active MTD 'user' of its departure.
432 * Returns zero on success or 1 on failure, which currently will happen
433 * if the requested device does not appear to be present in the list.
434 */
435
436int del_mtd_device(struct mtd_info *mtd)
437{
438 int ret;
439 struct mtd_notifier *not;
440
441 mutex_lock(&mtd_table_mutex);
442
443 if (idr_find(&mtd_idr, mtd->index) != mtd) {
444 ret = -ENODEV;
445 goto out_error;
446 }
447
448 /* No need to get a refcount on the module containing
449 the notifier, since we hold the mtd_table_mutex */
450 list_for_each_entry(not, &mtd_notifiers, list)
451 not->remove(mtd);
452
453 if (mtd->usecount) {
454 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
455 mtd->index, mtd->name, mtd->usecount);
456 ret = -EBUSY;
457 } else {
458 device_unregister(&mtd->dev);
459
460 idr_remove(&mtd_idr, mtd->index);
461
462 module_put(THIS_MODULE);
463 ret = 0;
464 }
465
466out_error:
467 mutex_unlock(&mtd_table_mutex);
468 return ret;
469}
470
471/**
472 * mtd_device_parse_register - parse partitions and register an MTD device.
473 *
474 * @mtd: the MTD device to register
475 * @types: the list of MTD partition probes to try, see
476 * 'parse_mtd_partitions()' for more information
477 * @parser_data: MTD partition parser-specific data
478 * @parts: fallback partition information to register, if parsing fails;
479 * only valid if %nr_parts > %0
480 * @nr_parts: the number of partitions in parts, if zero then the full
481 * MTD device is registered if no partition info is found
482 *
483 * This function aggregates MTD partitions parsing (done by
484 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
485 * basically follows the most common pattern found in many MTD drivers:
486 *
487 * * It first tries to probe partitions on MTD device @mtd using parsers
488 * specified in @types (if @types is %NULL, then the default list of parsers
489 * is used, see 'parse_mtd_partitions()' for more information). If none are
490 * found this functions tries to fallback to information specified in
491 * @parts/@nr_parts.
492 * * If any partitioning info was found, this function registers the found
493 * partitions.
494 * * If no partitions were found this function just registers the MTD device
495 * @mtd and exits.
496 *
497 * Returns zero in case of success and a negative error code in case of failure.
498 */
499int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
500 struct mtd_part_parser_data *parser_data,
501 const struct mtd_partition *parts,
502 int nr_parts)
503{
504 int err;
505 struct mtd_partition *real_parts;
506
507 err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
508 if (err <= 0 && nr_parts && parts) {
509 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
510 GFP_KERNEL);
511 if (!real_parts)
512 err = -ENOMEM;
513 else
514 err = nr_parts;
515 }
516
517 if (err > 0) {
518 err = add_mtd_partitions(mtd, real_parts, err);
519 kfree(real_parts);
520 } else if (err == 0) {
521 err = add_mtd_device(mtd);
522 if (err == 1)
523 err = -ENODEV;
524 }
525
526 return err;
527}
528EXPORT_SYMBOL_GPL(mtd_device_parse_register);
529
530/**
531 * mtd_device_unregister - unregister an existing MTD device.
532 *
533 * @master: the MTD device to unregister. This will unregister both the master
534 * and any partitions if registered.
535 */
536int mtd_device_unregister(struct mtd_info *master)
537{
538 int err;
539
540 err = del_mtd_partitions(master);
541 if (err)
542 return err;
543
544 if (!device_is_registered(&master->dev))
545 return 0;
546
547 return del_mtd_device(master);
548}
549EXPORT_SYMBOL_GPL(mtd_device_unregister);
550
551/**
552 * register_mtd_user - register a 'user' of MTD devices.
553 * @new: pointer to notifier info structure
554 *
555 * Registers a pair of callbacks function to be called upon addition
556 * or removal of MTD devices. Causes the 'add' callback to be immediately
557 * invoked for each MTD device currently present in the system.
558 */
559void register_mtd_user (struct mtd_notifier *new)
560{
561 struct mtd_info *mtd;
562
563 mutex_lock(&mtd_table_mutex);
564
565 list_add(&new->list, &mtd_notifiers);
566
567 __module_get(THIS_MODULE);
568
569 mtd_for_each_device(mtd)
570 new->add(mtd);
571
572 mutex_unlock(&mtd_table_mutex);
573}
574EXPORT_SYMBOL_GPL(register_mtd_user);
575
576/**
577 * unregister_mtd_user - unregister a 'user' of MTD devices.
578 * @old: pointer to notifier info structure
579 *
580 * Removes a callback function pair from the list of 'users' to be
581 * notified upon addition or removal of MTD devices. Causes the
582 * 'remove' callback to be immediately invoked for each MTD device
583 * currently present in the system.
584 */
585int unregister_mtd_user (struct mtd_notifier *old)
586{
587 struct mtd_info *mtd;
588
589 mutex_lock(&mtd_table_mutex);
590
591 module_put(THIS_MODULE);
592
593 mtd_for_each_device(mtd)
594 old->remove(mtd);
595
596 list_del(&old->list);
597 mutex_unlock(&mtd_table_mutex);
598 return 0;
599}
600EXPORT_SYMBOL_GPL(unregister_mtd_user);
601
602/**
603 * get_mtd_device - obtain a validated handle for an MTD device
604 * @mtd: last known address of the required MTD device
605 * @num: internal device number of the required MTD device
606 *
607 * Given a number and NULL address, return the num'th entry in the device
608 * table, if any. Given an address and num == -1, search the device table
609 * for a device with that address and return if it's still present. Given
610 * both, return the num'th driver only if its address matches. Return
611 * error code if not.
612 */
613struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
614{
615 struct mtd_info *ret = NULL, *other;
616 int err = -ENODEV;
617
618 mutex_lock(&mtd_table_mutex);
619
620 if (num == -1) {
621 mtd_for_each_device(other) {
622 if (other == mtd) {
623 ret = mtd;
624 break;
625 }
626 }
627 } else if (num >= 0) {
628 ret = idr_find(&mtd_idr, num);
629 if (mtd && mtd != ret)
630 ret = NULL;
631 }
632
633 if (!ret) {
634 ret = ERR_PTR(err);
635 goto out;
636 }
637
638 err = __get_mtd_device(ret);
639 if (err)
640 ret = ERR_PTR(err);
641out:
642 mutex_unlock(&mtd_table_mutex);
643 return ret;
644}
645EXPORT_SYMBOL_GPL(get_mtd_device);
646
647
648int __get_mtd_device(struct mtd_info *mtd)
649{
650 int err;
651
652 if (!try_module_get(mtd->owner))
653 return -ENODEV;
654
655 if (mtd->_get_device) {
656 err = mtd->_get_device(mtd);
657
658 if (err) {
659 module_put(mtd->owner);
660 return err;
661 }
662 }
663 mtd->usecount++;
664 return 0;
665}
666EXPORT_SYMBOL_GPL(__get_mtd_device);
667
668/**
669 * get_mtd_device_nm - obtain a validated handle for an MTD device by
670 * device name
671 * @name: MTD device name to open
672 *
673 * This function returns MTD device description structure in case of
674 * success and an error code in case of failure.
675 */
676struct mtd_info *get_mtd_device_nm(const char *name)
677{
678 int err = -ENODEV;
679 struct mtd_info *mtd = NULL, *other;
680
681 mutex_lock(&mtd_table_mutex);
682
683 mtd_for_each_device(other) {
684 if (!strcmp(name, other->name)) {
685 mtd = other;
686 break;
687 }
688 }
689
690 if (!mtd)
691 goto out_unlock;
692
693 err = __get_mtd_device(mtd);
694 if (err)
695 goto out_unlock;
696
697 mutex_unlock(&mtd_table_mutex);
698 return mtd;
699
700out_unlock:
701 mutex_unlock(&mtd_table_mutex);
702 return ERR_PTR(err);
703}
704EXPORT_SYMBOL_GPL(get_mtd_device_nm);
705
706void put_mtd_device(struct mtd_info *mtd)
707{
708 mutex_lock(&mtd_table_mutex);
709 __put_mtd_device(mtd);
710 mutex_unlock(&mtd_table_mutex);
711
712}
713EXPORT_SYMBOL_GPL(put_mtd_device);
714
715void __put_mtd_device(struct mtd_info *mtd)
716{
717 --mtd->usecount;
718 BUG_ON(mtd->usecount < 0);
719
720 if (mtd->_put_device)
721 mtd->_put_device(mtd);
722
723 module_put(mtd->owner);
724}
725EXPORT_SYMBOL_GPL(__put_mtd_device);
726
727/*
728 * Erase is an asynchronous operation. Device drivers are supposed
729 * to call instr->callback() whenever the operation completes, even
730 * if it completes with a failure.
731 * Callers are supposed to pass a callback function and wait for it
732 * to be called before writing to the block.
733 */
734int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
735{
736 if (instr->addr > mtd->size || instr->len > mtd->size - instr->addr)
737 return -EINVAL;
738 if (!(mtd->flags & MTD_WRITEABLE))
739 return -EROFS;
740 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
741 if (!instr->len) {
742 instr->state = MTD_ERASE_DONE;
743 mtd_erase_callback(instr);
744 return 0;
745 }
746 return mtd->_erase(mtd, instr);
747}
748EXPORT_SYMBOL_GPL(mtd_erase);
749
750/*
751 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
752 */
753int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
754 void **virt, resource_size_t *phys)
755{
756 *retlen = 0;
757 *virt = NULL;
758 if (phys)
759 *phys = 0;
760 if (!mtd->_point)
761 return -EOPNOTSUPP;
762 if (from < 0 || from > mtd->size || len > mtd->size - from)
763 return -EINVAL;
764 if (!len)
765 return 0;
766 return mtd->_point(mtd, from, len, retlen, virt, phys);
767}
768EXPORT_SYMBOL_GPL(mtd_point);
769
770/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
771int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
772{
773 if (!mtd->_point)
774 return -EOPNOTSUPP;
775 if (from < 0 || from > mtd->size || len > mtd->size - from)
776 return -EINVAL;
777 if (!len)
778 return 0;
779 return mtd->_unpoint(mtd, from, len);
780}
781EXPORT_SYMBOL_GPL(mtd_unpoint);
782
783/*
784 * Allow NOMMU mmap() to directly map the device (if not NULL)
785 * - return the address to which the offset maps
786 * - return -ENOSYS to indicate refusal to do the mapping
787 */
788unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
789 unsigned long offset, unsigned long flags)
790{
791 if (!mtd->_get_unmapped_area)
792 return -EOPNOTSUPP;
793 if (offset > mtd->size || len > mtd->size - offset)
794 return -EINVAL;
795 return mtd->_get_unmapped_area(mtd, len, offset, flags);
796}
797EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
798
799int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
800 u_char *buf)
801{
802 int ret_code;
803 *retlen = 0;
804 if (from < 0 || from > mtd->size || len > mtd->size - from)
805 return -EINVAL;
806 if (!len)
807 return 0;
808
809 /*
810 * In the absence of an error, drivers return a non-negative integer
811 * representing the maximum number of bitflips that were corrected on
812 * any one ecc region (if applicable; zero otherwise).
813 */
814 ret_code = mtd->_read(mtd, from, len, retlen, buf);
815 if (unlikely(ret_code < 0))
816 return ret_code;
817 if (mtd->ecc_strength == 0)
818 return 0; /* device lacks ecc */
819 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
820}
821EXPORT_SYMBOL_GPL(mtd_read);
822
823int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
824 const u_char *buf)
825{
826 *retlen = 0;
827 if (to < 0 || to > mtd->size || len > mtd->size - to)
828 return -EINVAL;
829 if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
830 return -EROFS;
831 if (!len)
832 return 0;
833 return mtd->_write(mtd, to, len, retlen, buf);
834}
835EXPORT_SYMBOL_GPL(mtd_write);
836
837/*
838 * In blackbox flight recorder like scenarios we want to make successful writes
839 * in interrupt context. panic_write() is only intended to be called when its
840 * known the kernel is about to panic and we need the write to succeed. Since
841 * the kernel is not going to be running for much longer, this function can
842 * break locks and delay to ensure the write succeeds (but not sleep).
843 */
844int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
845 const u_char *buf)
846{
847 *retlen = 0;
848 if (!mtd->_panic_write)
849 return -EOPNOTSUPP;
850 if (to < 0 || to > mtd->size || len > mtd->size - to)
851 return -EINVAL;
852 if (!(mtd->flags & MTD_WRITEABLE))
853 return -EROFS;
854 if (!len)
855 return 0;
856 return mtd->_panic_write(mtd, to, len, retlen, buf);
857}
858EXPORT_SYMBOL_GPL(mtd_panic_write);
859
860int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
861{
862 int ret_code;
863 ops->retlen = ops->oobretlen = 0;
864 if (!mtd->_read_oob)
865 return -EOPNOTSUPP;
866 /*
867 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
868 * similar to mtd->_read(), returning a non-negative integer
869 * representing max bitflips. In other cases, mtd->_read_oob() may
870 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
871 */
872 ret_code = mtd->_read_oob(mtd, from, ops);
873 if (unlikely(ret_code < 0))
874 return ret_code;
875 if (mtd->ecc_strength == 0)
876 return 0; /* device lacks ecc */
877 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
878}
879EXPORT_SYMBOL_GPL(mtd_read_oob);
880
881/*
882 * Method to access the protection register area, present in some flash
883 * devices. The user data is one time programmable but the factory data is read
884 * only.
885 */
886int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
887 struct otp_info *buf)
888{
889 if (!mtd->_get_fact_prot_info)
890 return -EOPNOTSUPP;
891 if (!len)
892 return 0;
893 return mtd->_get_fact_prot_info(mtd, len, retlen, buf);
894}
895EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
896
897int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
898 size_t *retlen, u_char *buf)
899{
900 *retlen = 0;
901 if (!mtd->_read_fact_prot_reg)
902 return -EOPNOTSUPP;
903 if (!len)
904 return 0;
905 return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
906}
907EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
908
909int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
910 struct otp_info *buf)
911{
912 if (!mtd->_get_user_prot_info)
913 return -EOPNOTSUPP;
914 if (!len)
915 return 0;
916 return mtd->_get_user_prot_info(mtd, len, retlen, buf);
917}
918EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
919
920int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
921 size_t *retlen, u_char *buf)
922{
923 *retlen = 0;
924 if (!mtd->_read_user_prot_reg)
925 return -EOPNOTSUPP;
926 if (!len)
927 return 0;
928 return mtd->_read_user_prot_reg(mtd, from, len, retlen, buf);
929}
930EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
931
932int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
933 size_t *retlen, u_char *buf)
934{
935 int ret;
936
937 *retlen = 0;
938 if (!mtd->_write_user_prot_reg)
939 return -EOPNOTSUPP;
940 if (!len)
941 return 0;
942 ret = mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
943 if (ret)
944 return ret;
945
946 /*
947 * If no data could be written at all, we are out of memory and
948 * must return -ENOSPC.
949 */
950 return (*retlen) ? 0 : -ENOSPC;
951}
952EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
953
954int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
955{
956 if (!mtd->_lock_user_prot_reg)
957 return -EOPNOTSUPP;
958 if (!len)
959 return 0;
960 return mtd->_lock_user_prot_reg(mtd, from, len);
961}
962EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
963
964/* Chip-supported device locking */
965int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
966{
967 if (!mtd->_lock)
968 return -EOPNOTSUPP;
969 if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
970 return -EINVAL;
971 if (!len)
972 return 0;
973 return mtd->_lock(mtd, ofs, len);
974}
975EXPORT_SYMBOL_GPL(mtd_lock);
976
977int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
978{
979 if (!mtd->_unlock)
980 return -EOPNOTSUPP;
981 if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
982 return -EINVAL;
983 if (!len)
984 return 0;
985 return mtd->_unlock(mtd, ofs, len);
986}
987EXPORT_SYMBOL_GPL(mtd_unlock);
988
989int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
990{
991 if (!mtd->_is_locked)
992 return -EOPNOTSUPP;
993 if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
994 return -EINVAL;
995 if (!len)
996 return 0;
997 return mtd->_is_locked(mtd, ofs, len);
998}
999EXPORT_SYMBOL_GPL(mtd_is_locked);
1000
1001int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1002{
1003 if (!mtd->_block_isbad)
1004 return 0;
1005 if (ofs < 0 || ofs > mtd->size)
1006 return -EINVAL;
1007 return mtd->_block_isbad(mtd, ofs);
1008}
1009EXPORT_SYMBOL_GPL(mtd_block_isbad);
1010
1011int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1012{
1013 if (!mtd->_block_markbad)
1014 return -EOPNOTSUPP;
1015 if (ofs < 0 || ofs > mtd->size)
1016 return -EINVAL;
1017 if (!(mtd->flags & MTD_WRITEABLE))
1018 return -EROFS;
1019 return mtd->_block_markbad(mtd, ofs);
1020}
1021EXPORT_SYMBOL_GPL(mtd_block_markbad);
1022
1023/*
1024 * default_mtd_writev - the default writev method
1025 * @mtd: mtd device description object pointer
1026 * @vecs: the vectors to write
1027 * @count: count of vectors in @vecs
1028 * @to: the MTD device offset to write to
1029 * @retlen: on exit contains the count of bytes written to the MTD device.
1030 *
1031 * This function returns zero in case of success and a negative error code in
1032 * case of failure.
1033 */
1034static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1035 unsigned long count, loff_t to, size_t *retlen)
1036{
1037 unsigned long i;
1038 size_t totlen = 0, thislen;
1039 int ret = 0;
1040
1041 for (i = 0; i < count; i++) {
1042 if (!vecs[i].iov_len)
1043 continue;
1044 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1045 vecs[i].iov_base);
1046 totlen += thislen;
1047 if (ret || thislen != vecs[i].iov_len)
1048 break;
1049 to += vecs[i].iov_len;
1050 }
1051 *retlen = totlen;
1052 return ret;
1053}
1054
1055/*
1056 * mtd_writev - the vector-based MTD write method
1057 * @mtd: mtd device description object pointer
1058 * @vecs: the vectors to write
1059 * @count: count of vectors in @vecs
1060 * @to: the MTD device offset to write to
1061 * @retlen: on exit contains the count of bytes written to the MTD device.
1062 *
1063 * This function returns zero in case of success and a negative error code in
1064 * case of failure.
1065 */
1066int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1067 unsigned long count, loff_t to, size_t *retlen)
1068{
1069 *retlen = 0;
1070 if (!(mtd->flags & MTD_WRITEABLE))
1071 return -EROFS;
1072 if (!mtd->_writev)
1073 return default_mtd_writev(mtd, vecs, count, to, retlen);
1074 return mtd->_writev(mtd, vecs, count, to, retlen);
1075}
1076EXPORT_SYMBOL_GPL(mtd_writev);
1077
1078/**
1079 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1080 * @mtd: mtd device description object pointer
1081 * @size: a pointer to the ideal or maximum size of the allocation, points
1082 * to the actual allocation size on success.
1083 *
1084 * This routine attempts to allocate a contiguous kernel buffer up to
1085 * the specified size, backing off the size of the request exponentially
1086 * until the request succeeds or until the allocation size falls below
1087 * the system page size. This attempts to make sure it does not adversely
1088 * impact system performance, so when allocating more than one page, we
1089 * ask the memory allocator to avoid re-trying, swapping, writing back
1090 * or performing I/O.
1091 *
1092 * Note, this function also makes sure that the allocated buffer is aligned to
1093 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1094 *
1095 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1096 * to handle smaller (i.e. degraded) buffer allocations under low- or
1097 * fragmented-memory situations where such reduced allocations, from a
1098 * requested ideal, are allowed.
1099 *
1100 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1101 */
1102void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1103{
1104 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
1105 __GFP_NORETRY | __GFP_NO_KSWAPD;
1106 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1107 void *kbuf;
1108
1109 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1110
1111 while (*size > min_alloc) {
1112 kbuf = kmalloc(*size, flags);
1113 if (kbuf)
1114 return kbuf;
1115
1116 *size >>= 1;
1117 *size = ALIGN(*size, mtd->writesize);
1118 }
1119
1120 /*
1121 * For the last resort allocation allow 'kmalloc()' to do all sorts of
1122 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
1123 */
1124 return kmalloc(*size, GFP_KERNEL);
1125}
1126EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1127
1128#ifdef CONFIG_PROC_FS
1129
1130/*====================================================================*/
1131/* Support for /proc/mtd */
1132
1133static int mtd_proc_show(struct seq_file *m, void *v)
1134{
1135 struct mtd_info *mtd;
1136
1137 seq_puts(m, "dev: size erasesize name\n");
1138 mutex_lock(&mtd_table_mutex);
1139 mtd_for_each_device(mtd) {
1140 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
1141 mtd->index, (unsigned long long)mtd->size,
1142 mtd->erasesize, mtd->name);
1143 }
1144 mutex_unlock(&mtd_table_mutex);
1145 return 0;
1146}
1147
1148static int mtd_proc_open(struct inode *inode, struct file *file)
1149{
1150 return single_open(file, mtd_proc_show, NULL);
1151}
1152
1153static const struct file_operations mtd_proc_ops = {
1154 .open = mtd_proc_open,
1155 .read = seq_read,
1156 .llseek = seq_lseek,
1157 .release = single_release,
1158};
1159#endif /* CONFIG_PROC_FS */
1160
1161/*====================================================================*/
1162/* Init code */
1163
1164static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
1165{
1166 int ret;
1167
1168 ret = bdi_init(bdi);
1169 if (!ret)
1170 ret = bdi_register(bdi, NULL, "%s", name);
1171
1172 if (ret)
1173 bdi_destroy(bdi);
1174
1175 return ret;
1176}
1177
1178static struct proc_dir_entry *proc_mtd;
1179
1180static int __init init_mtd(void)
1181{
1182 int ret;
1183
1184 ret = class_register(&mtd_class);
1185 if (ret)
1186 goto err_reg;
1187
1188 ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
1189 if (ret)
1190 goto err_bdi1;
1191
1192 ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
1193 if (ret)
1194 goto err_bdi2;
1195
1196 ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
1197 if (ret)
1198 goto err_bdi3;
1199
1200 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1201
1202 ret = init_mtdchar();
1203 if (ret)
1204 goto out_procfs;
1205
1206 return 0;
1207
1208out_procfs:
1209 if (proc_mtd)
1210 remove_proc_entry("mtd", NULL);
1211err_bdi3:
1212 bdi_destroy(&mtd_bdi_ro_mappable);
1213err_bdi2:
1214 bdi_destroy(&mtd_bdi_unmappable);
1215err_bdi1:
1216 class_unregister(&mtd_class);
1217err_reg:
1218 pr_err("Error registering mtd class or bdi: %d\n", ret);
1219 return ret;
1220}
1221
1222static void __exit cleanup_mtd(void)
1223{
1224 cleanup_mtdchar();
1225 if (proc_mtd)
1226 remove_proc_entry("mtd", NULL);
1227 class_unregister(&mtd_class);
1228 bdi_destroy(&mtd_bdi_unmappable);
1229 bdi_destroy(&mtd_bdi_ro_mappable);
1230 bdi_destroy(&mtd_bdi_rw_mappable);
1231}
1232
1233module_init(init_mtd);
1234module_exit(cleanup_mtd);
1235
1236MODULE_LICENSE("GPL");
1237MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1238MODULE_DESCRIPTION("Core MTD registration and access routines");