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jme: Do not enable NIC WoL functions on S0
[linux/fpc-iii.git] / drivers / mtd / mtd_blkdevs.c
blobf2af5b91c0e34f1ee73eecce987a6abde676c920
1 /*
2 * Interface to Linux block layer for MTD 'translation layers'.
3 *
4 * Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/list.h>
26 #include <linux/fs.h>
27 #include <linux/mtd/blktrans.h>
28 #include <linux/mtd/mtd.h>
29 #include <linux/blkdev.h>
30 #include <linux/blkpg.h>
31 #include <linux/spinlock.h>
32 #include <linux/hdreg.h>
33 #include <linux/mutex.h>
34 #include <asm/uaccess.h>
35
36 #include "mtdcore.h"
37
38 static LIST_HEAD(blktrans_majors);
39 static DEFINE_MUTEX(blktrans_ref_mutex);
40
41 static void blktrans_dev_release(struct kref *kref)
42 {
43 struct mtd_blktrans_dev *dev =
44 container_of(kref, struct mtd_blktrans_dev, ref);
45
46 dev->disk->private_data = NULL;
47 blk_cleanup_queue(dev->rq);
48 put_disk(dev->disk);
49 list_del(&dev->list);
50 kfree(dev);
51 }
52
53 static struct mtd_blktrans_dev *blktrans_dev_get(struct gendisk *disk)
54 {
55 struct mtd_blktrans_dev *dev;
56
57 mutex_lock(&blktrans_ref_mutex);
58 dev = disk->private_data;
59
60 if (!dev)
61 goto unlock;
62 kref_get(&dev->ref);
63 unlock:
64 mutex_unlock(&blktrans_ref_mutex);
65 return dev;
66 }
67
68 static void blktrans_dev_put(struct mtd_blktrans_dev *dev)
69 {
70 mutex_lock(&blktrans_ref_mutex);
71 kref_put(&dev->ref, blktrans_dev_release);
72 mutex_unlock(&blktrans_ref_mutex);
73 }
74
75
76 static int do_blktrans_request(struct mtd_blktrans_ops *tr,
77 struct mtd_blktrans_dev *dev,
78 struct request *req)
79 {
80 unsigned long block, nsect;
81 char *buf;
82
83 block = blk_rq_pos(req) << 9 >> tr->blkshift;
84 nsect = blk_rq_cur_bytes(req) >> tr->blkshift;
85 buf = bio_data(req->bio);
86
87 if (req->cmd_type != REQ_TYPE_FS)
88 return -EIO;
89
90 if (req->cmd_flags & REQ_FLUSH)
91 return tr->flush(dev);
92
93 if (blk_rq_pos(req) + blk_rq_cur_sectors(req) >
94 get_capacity(req->rq_disk))
95 return -EIO;
96
97 if (req->cmd_flags & REQ_DISCARD)
98 return tr->discard(dev, block, nsect);
99
100 switch(rq_data_dir(req)) {
101 case READ:
102 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
103 if (tr->readsect(dev, block, buf))
104 return -EIO;
105 rq_flush_dcache_pages(req);
106 return 0;
107 case WRITE:
108 if (!tr->writesect)
109 return -EIO;
110
111 rq_flush_dcache_pages(req);
112 for (; nsect > 0; nsect--, block++, buf += tr->blksize)
113 if (tr->writesect(dev, block, buf))
114 return -EIO;
115 return 0;
116 default:
117 printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req));
118 return -EIO;
119 }
120 }
121
122 int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev)
123 {
124 return dev->bg_stop;
125 }
126 EXPORT_SYMBOL_GPL(mtd_blktrans_cease_background);
127
128 static void mtd_blktrans_work(struct work_struct *work)
129 {
130 struct mtd_blktrans_dev *dev =
131 container_of(work, struct mtd_blktrans_dev, work);
132 struct mtd_blktrans_ops *tr = dev->tr;
133 struct request_queue *rq = dev->rq;
134 struct request *req = NULL;
135 int background_done = 0;
136
137 spin_lock_irq(rq->queue_lock);
138
139 while (1) {
140 int res;
141
142 dev->bg_stop = false;
143 if (!req && !(req = blk_fetch_request(rq))) {
144 if (tr->background && !background_done) {
145 spin_unlock_irq(rq->queue_lock);
146 mutex_lock(&dev->lock);
147 tr->background(dev);
148 mutex_unlock(&dev->lock);
149 spin_lock_irq(rq->queue_lock);
150 /*
151 * Do background processing just once per idle
152 * period.
153 */
154 background_done = !dev->bg_stop;
155 continue;
156 }
157 break;
158 }
159
160 spin_unlock_irq(rq->queue_lock);
161
162 mutex_lock(&dev->lock);
163 res = do_blktrans_request(dev->tr, dev, req);
164 mutex_unlock(&dev->lock);
165
166 spin_lock_irq(rq->queue_lock);
167
168 if (!__blk_end_request_cur(req, res))
169 req = NULL;
170
171 background_done = 0;
172 }
173
174 if (req)
175 __blk_end_request_all(req, -EIO);
176
177 spin_unlock_irq(rq->queue_lock);
178 }
179
180 static void mtd_blktrans_request(struct request_queue *rq)
181 {
182 struct mtd_blktrans_dev *dev;
183 struct request *req = NULL;
184
185 dev = rq->queuedata;
186
187 if (!dev)
188 while ((req = blk_fetch_request(rq)) != NULL)
189 __blk_end_request_all(req, -ENODEV);
190 else
191 queue_work(dev->wq, &dev->work);
192 }
193
194 static int blktrans_open(struct block_device *bdev, fmode_t mode)
195 {
196 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
197 int ret = 0;
198
199 if (!dev)
200 return -ERESTARTSYS; /* FIXME: busy loop! -arnd*/
201
202 mutex_lock(&mtd_table_mutex);
203 mutex_lock(&dev->lock);
204
205 if (dev->open)
206 goto unlock;
207
208 kref_get(&dev->ref);
209 __module_get(dev->tr->owner);
210
211 if (!dev->mtd)
212 goto unlock;
213
214 if (dev->tr->open) {
215 ret = dev->tr->open(dev);
216 if (ret)
217 goto error_put;
218 }
219
220 ret = __get_mtd_device(dev->mtd);
221 if (ret)
222 goto error_release;
223 dev->file_mode = mode;
224
225 unlock:
226 dev->open++;
227 mutex_unlock(&dev->lock);
228 mutex_unlock(&mtd_table_mutex);
229 blktrans_dev_put(dev);
230 return ret;
231
232 error_release:
233 if (dev->tr->release)
234 dev->tr->release(dev);
235 error_put:
236 module_put(dev->tr->owner);
237 kref_put(&dev->ref, blktrans_dev_release);
238 mutex_unlock(&dev->lock);
239 mutex_unlock(&mtd_table_mutex);
240 blktrans_dev_put(dev);
241 return ret;
242 }
243
244 static void blktrans_release(struct gendisk *disk, fmode_t mode)
245 {
246 struct mtd_blktrans_dev *dev = blktrans_dev_get(disk);
247
248 if (!dev)
249 return;
250
251 mutex_lock(&mtd_table_mutex);
252 mutex_lock(&dev->lock);
253
254 if (--dev->open)
255 goto unlock;
256
257 kref_put(&dev->ref, blktrans_dev_release);
258 module_put(dev->tr->owner);
259
260 if (dev->mtd) {
261 if (dev->tr->release)
262 dev->tr->release(dev);
263 __put_mtd_device(dev->mtd);
264 }
265 unlock:
266 mutex_unlock(&dev->lock);
267 mutex_unlock(&mtd_table_mutex);
268 blktrans_dev_put(dev);
269 }
270
271 static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
272 {
273 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
274 int ret = -ENXIO;
275
276 if (!dev)
277 return ret;
278
279 mutex_lock(&dev->lock);
280
281 if (!dev->mtd)
282 goto unlock;
283
284 ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0;
285 unlock:
286 mutex_unlock(&dev->lock);
287 blktrans_dev_put(dev);
288 return ret;
289 }
290
291 static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
292 unsigned int cmd, unsigned long arg)
293 {
294 struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
295 int ret = -ENXIO;
296
297 if (!dev)
298 return ret;
299
300 mutex_lock(&dev->lock);
301
302 if (!dev->mtd)
303 goto unlock;
304
305 switch (cmd) {
306 case BLKFLSBUF:
307 ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
308 break;
309 default:
310 ret = -ENOTTY;
311 }
312 unlock:
313 mutex_unlock(&dev->lock);
314 blktrans_dev_put(dev);
315 return ret;
316 }
317
318 static const struct block_device_operations mtd_block_ops = {
319 .owner = THIS_MODULE,
320 .open = blktrans_open,
321 .release = blktrans_release,
322 .ioctl = blktrans_ioctl,
323 .getgeo = blktrans_getgeo,
324 };
325
326 int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new)
327 {
328 struct mtd_blktrans_ops *tr = new->tr;
329 struct mtd_blktrans_dev *d;
330 int last_devnum = -1;
331 struct gendisk *gd;
332 int ret;
333
334 if (mutex_trylock(&mtd_table_mutex)) {
335 mutex_unlock(&mtd_table_mutex);
336 BUG();
337 }
338
339 mutex_lock(&blktrans_ref_mutex);
340 list_for_each_entry(d, &tr->devs, list) {
341 if (new->devnum == -1) {
342 /* Use first free number */
343 if (d->devnum != last_devnum+1) {
344 /* Found a free devnum. Plug it in here */
345 new->devnum = last_devnum+1;
346 list_add_tail(&new->list, &d->list);
347 goto added;
348 }
349 } else if (d->devnum == new->devnum) {
350 /* Required number taken */
351 mutex_unlock(&blktrans_ref_mutex);
352 return -EBUSY;
353 } else if (d->devnum > new->devnum) {
354 /* Required number was free */
355 list_add_tail(&new->list, &d->list);
356 goto added;
357 }
358 last_devnum = d->devnum;
359 }
360
361 ret = -EBUSY;
362 if (new->devnum == -1)
363 new->devnum = last_devnum+1;
364
365 /* Check that the device and any partitions will get valid
366 * minor numbers and that the disk naming code below can cope
367 * with this number. */
368 if (new->devnum > (MINORMASK >> tr->part_bits) ||
369 (tr->part_bits && new->devnum >= 27 * 26)) {
370 mutex_unlock(&blktrans_ref_mutex);
371 goto error1;
372 }
373
374 list_add_tail(&new->list, &tr->devs);
375 added:
376 mutex_unlock(&blktrans_ref_mutex);
377
378 mutex_init(&new->lock);
379 kref_init(&new->ref);
380 if (!tr->writesect)
381 new->readonly = 1;
382
383 /* Create gendisk */
384 ret = -ENOMEM;
385 gd = alloc_disk(1 << tr->part_bits);
386
387 if (!gd)
388 goto error2;
389
390 new->disk = gd;
391 gd->private_data = new;
392 gd->major = tr->major;
393 gd->first_minor = (new->devnum) << tr->part_bits;
394 gd->fops = &mtd_block_ops;
395
396 if (tr->part_bits)
397 if (new->devnum < 26)
398 snprintf(gd->disk_name, sizeof(gd->disk_name),
399 "%s%c", tr->name, 'a' + new->devnum);
400 else
401 snprintf(gd->disk_name, sizeof(gd->disk_name),
402 "%s%c%c", tr->name,
403 'a' - 1 + new->devnum / 26,
404 'a' + new->devnum % 26);
405 else
406 snprintf(gd->disk_name, sizeof(gd->disk_name),
407 "%s%d", tr->name, new->devnum);
408
409 set_capacity(gd, (new->size * tr->blksize) >> 9);
410
411 /* Create the request queue */
412 spin_lock_init(&new->queue_lock);
413 new->rq = blk_init_queue(mtd_blktrans_request, &new->queue_lock);
414
415 if (!new->rq)
416 goto error3;
417
418 if (tr->flush)
419 blk_queue_flush(new->rq, REQ_FLUSH);
420
421 new->rq->queuedata = new;
422 blk_queue_logical_block_size(new->rq, tr->blksize);
423
424 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, new->rq);
425
426 if (tr->discard) {
427 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, new->rq);
428 new->rq->limits.max_discard_sectors = UINT_MAX;
429 }
430
431 gd->queue = new->rq;
432
433 /* Create processing workqueue */
434 new->wq = alloc_workqueue("%s%d", 0, 0,
435 tr->name, new->mtd->index);
436 if (!new->wq)
437 goto error4;
438 INIT_WORK(&new->work, mtd_blktrans_work);
439
440 gd->driverfs_dev = &new->mtd->dev;
441
442 if (new->readonly)
443 set_disk_ro(gd, 1);
444
445 add_disk(gd);
446
447 if (new->disk_attributes) {
448 ret = sysfs_create_group(&disk_to_dev(gd)->kobj,
449 new->disk_attributes);
450 WARN_ON(ret);
451 }
452 return 0;
453 error4:
454 blk_cleanup_queue(new->rq);
455 error3:
456 put_disk(new->disk);
457 error2:
458 list_del(&new->list);
459 error1:
460 return ret;
461 }
462
463 int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old)
464 {
465 unsigned long flags;
466
467 if (mutex_trylock(&mtd_table_mutex)) {
468 mutex_unlock(&mtd_table_mutex);
469 BUG();
470 }
471
472 if (old->disk_attributes)
473 sysfs_remove_group(&disk_to_dev(old->disk)->kobj,
474 old->disk_attributes);
475
476 /* Stop new requests to arrive */
477 del_gendisk(old->disk);
478
479 /* Stop workqueue. This will perform any pending request. */
480 destroy_workqueue(old->wq);
481
482 /* Kill current requests */
483 spin_lock_irqsave(&old->queue_lock, flags);
484 old->rq->queuedata = NULL;
485 blk_start_queue(old->rq);
486 spin_unlock_irqrestore(&old->queue_lock, flags);
487
488 /* If the device is currently open, tell trans driver to close it,
489 then put mtd device, and don't touch it again */
490 mutex_lock(&old->lock);
491 if (old->open) {
492 if (old->tr->release)
493 old->tr->release(old);
494 __put_mtd_device(old->mtd);
495 }
496
497 old->mtd = NULL;
498
499 mutex_unlock(&old->lock);
500 blktrans_dev_put(old);
501 return 0;
502 }
503
504 static void blktrans_notify_remove(struct mtd_info *mtd)
505 {
506 struct mtd_blktrans_ops *tr;
507 struct mtd_blktrans_dev *dev, *next;
508
509 list_for_each_entry(tr, &blktrans_majors, list)
510 list_for_each_entry_safe(dev, next, &tr->devs, list)
511 if (dev->mtd == mtd)
512 tr->remove_dev(dev);
513 }
514
515 static void blktrans_notify_add(struct mtd_info *mtd)
516 {
517 struct mtd_blktrans_ops *tr;
518
519 if (mtd->type == MTD_ABSENT)
520 return;
521
522 list_for_each_entry(tr, &blktrans_majors, list)
523 tr->add_mtd(tr, mtd);
524 }
525
526 static struct mtd_notifier blktrans_notifier = {
527 .add = blktrans_notify_add,
528 .remove = blktrans_notify_remove,
529 };
530
531 int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
532 {
533 struct mtd_info *mtd;
534 int ret;
535
536 /* Register the notifier if/when the first device type is
537 registered, to prevent the link/init ordering from fucking
538 us over. */
539 if (!blktrans_notifier.list.next)
540 register_mtd_user(&blktrans_notifier);
541
542
543 mutex_lock(&mtd_table_mutex);
544
545 ret = register_blkdev(tr->major, tr->name);
546 if (ret < 0) {
547 printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n",
548 tr->name, tr->major, ret);
549 mutex_unlock(&mtd_table_mutex);
550 return ret;
551 }
552
553 if (ret)
554 tr->major = ret;
555
556 tr->blkshift = ffs(tr->blksize) - 1;
557
558 INIT_LIST_HEAD(&tr->devs);
559 list_add(&tr->list, &blktrans_majors);
560
561 mtd_for_each_device(mtd)
562 if (mtd->type != MTD_ABSENT)
563 tr->add_mtd(tr, mtd);
564
565 mutex_unlock(&mtd_table_mutex);
566 return 0;
567 }
568
569 int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr)
570 {
571 struct mtd_blktrans_dev *dev, *next;
572
573 mutex_lock(&mtd_table_mutex);
574
575 /* Remove it from the list of active majors */
576 list_del(&tr->list);
577
578 list_for_each_entry_safe(dev, next, &tr->devs, list)
579 tr->remove_dev(dev);
580
581 unregister_blkdev(tr->major, tr->name);
582 mutex_unlock(&mtd_table_mutex);
583
584 BUG_ON(!list_empty(&tr->devs));
585 return 0;
586 }
587
588 static void __exit mtd_blktrans_exit(void)
589 {
590 /* No race here -- if someone's currently in register_mtd_blktrans
591 we're screwed anyway. */
592 if (blktrans_notifier.list.next)
593 unregister_mtd_user(&blktrans_notifier);
594 }
595
596 module_exit(mtd_blktrans_exit);
597
598 EXPORT_SYMBOL_GPL(register_mtd_blktrans);
599 EXPORT_SYMBOL_GPL(deregister_mtd_blktrans);
600 EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev);
601 EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev);
602
603 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
604 MODULE_LICENSE("GPL");
605 MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");
Linux with added FPC-III support