2 * (C) 2003 David Woodhouse <dwmw2@infradead.org>
4 * Interface to Linux 2.5 block layer for MTD 'translation layers'.
8 #include <linux/kernel.h>
9 #include <linux/slab.h>
10 #include <linux/module.h>
11 #include <linux/list.h>
13 #include <linux/mtd/blktrans.h>
14 #include <linux/mtd/mtd.h>
15 #include <linux/blkdev.h>
16 #include <linux/blkpg.h>
17 #include <linux/spinlock.h>
18 #include <linux/smp_lock.h>
19 #include <linux/hdreg.h>
20 #include <linux/init.h>
21 #include <linux/mutex.h>
22 #include <linux/kthread.h>
23 #include <asm/uaccess.h>
27 static LIST_HEAD(blktrans_majors
);
28 static DEFINE_MUTEX(blktrans_ref_mutex
);
30 void blktrans_dev_release(struct kref
*kref
)
32 struct mtd_blktrans_dev
*dev
=
33 container_of(kref
, struct mtd_blktrans_dev
, ref
);
35 dev
->disk
->private_data
= NULL
;
36 blk_cleanup_queue(dev
->rq
);
42 static struct mtd_blktrans_dev
*blktrans_dev_get(struct gendisk
*disk
)
44 struct mtd_blktrans_dev
*dev
;
46 mutex_lock(&blktrans_ref_mutex
);
47 dev
= disk
->private_data
;
53 mutex_unlock(&blktrans_ref_mutex
);
57 void blktrans_dev_put(struct mtd_blktrans_dev
*dev
)
59 mutex_lock(&blktrans_ref_mutex
);
60 kref_put(&dev
->ref
, blktrans_dev_release
);
61 mutex_unlock(&blktrans_ref_mutex
);
65 static int do_blktrans_request(struct mtd_blktrans_ops
*tr
,
66 struct mtd_blktrans_dev
*dev
,
69 unsigned long block
, nsect
;
72 block
= blk_rq_pos(req
) << 9 >> tr
->blkshift
;
73 nsect
= blk_rq_cur_bytes(req
) >> tr
->blkshift
;
77 if (req
->cmd_type
!= REQ_TYPE_FS
)
80 if (blk_rq_pos(req
) + blk_rq_cur_sectors(req
) >
81 get_capacity(req
->rq_disk
))
84 if (req
->cmd_flags
& REQ_DISCARD
)
85 return tr
->discard(dev
, block
, nsect
);
87 switch(rq_data_dir(req
)) {
89 for (; nsect
> 0; nsect
--, block
++, buf
+= tr
->blksize
)
90 if (tr
->readsect(dev
, block
, buf
))
92 rq_flush_dcache_pages(req
);
98 rq_flush_dcache_pages(req
);
99 for (; nsect
> 0; nsect
--, block
++, buf
+= tr
->blksize
)
100 if (tr
->writesect(dev
, block
, buf
))
104 printk(KERN_NOTICE
"Unknown request %u\n", rq_data_dir(req
));
109 static int mtd_blktrans_thread(void *arg
)
111 struct mtd_blktrans_dev
*dev
= arg
;
112 struct request_queue
*rq
= dev
->rq
;
113 struct request
*req
= NULL
;
115 spin_lock_irq(rq
->queue_lock
);
117 while (!kthread_should_stop()) {
120 if (!req
&& !(req
= blk_fetch_request(rq
))) {
121 set_current_state(TASK_INTERRUPTIBLE
);
122 spin_unlock_irq(rq
->queue_lock
);
124 spin_lock_irq(rq
->queue_lock
);
128 spin_unlock_irq(rq
->queue_lock
);
130 mutex_lock(&dev
->lock
);
131 res
= do_blktrans_request(dev
->tr
, dev
, req
);
132 mutex_unlock(&dev
->lock
);
134 spin_lock_irq(rq
->queue_lock
);
136 if (!__blk_end_request_cur(req
, res
))
141 __blk_end_request_all(req
, -EIO
);
143 spin_unlock_irq(rq
->queue_lock
);
148 static void mtd_blktrans_request(struct request_queue
*rq
)
150 struct mtd_blktrans_dev
*dev
;
151 struct request
*req
= NULL
;
156 while ((req
= blk_fetch_request(rq
)) != NULL
)
157 __blk_end_request_all(req
, -ENODEV
);
159 wake_up_process(dev
->thread
);
162 static int blktrans_open(struct block_device
*bdev
, fmode_t mode
)
164 struct mtd_blktrans_dev
*dev
= blktrans_dev_get(bdev
->bd_disk
);
168 return -ERESTARTSYS
; /* FIXME: busy loop! -arnd*/
171 mutex_lock(&dev
->lock
);
178 ret
= !dev
->open
++ && dev
->tr
->open
? dev
->tr
->open(dev
) : 0;
180 /* Take another reference on the device so it won't go away till
185 mutex_unlock(&dev
->lock
);
186 blktrans_dev_put(dev
);
191 static int blktrans_release(struct gendisk
*disk
, fmode_t mode
)
193 struct mtd_blktrans_dev
*dev
= blktrans_dev_get(disk
);
200 mutex_lock(&dev
->lock
);
202 /* Release one reference, we sure its not the last one here*/
203 kref_put(&dev
->ref
, blktrans_dev_release
);
208 ret
= !--dev
->open
&& dev
->tr
->release
? dev
->tr
->release(dev
) : 0;
210 mutex_unlock(&dev
->lock
);
211 blktrans_dev_put(dev
);
216 static int blktrans_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
218 struct mtd_blktrans_dev
*dev
= blktrans_dev_get(bdev
->bd_disk
);
224 mutex_lock(&dev
->lock
);
229 ret
= dev
->tr
->getgeo
? dev
->tr
->getgeo(dev
, geo
) : 0;
231 mutex_unlock(&dev
->lock
);
232 blktrans_dev_put(dev
);
236 static int blktrans_ioctl(struct block_device
*bdev
, fmode_t mode
,
237 unsigned int cmd
, unsigned long arg
)
239 struct mtd_blktrans_dev
*dev
= blktrans_dev_get(bdev
->bd_disk
);
246 mutex_lock(&dev
->lock
);
253 ret
= dev
->tr
->flush
? dev
->tr
->flush(dev
) : 0;
258 mutex_unlock(&dev
->lock
);
260 blktrans_dev_put(dev
);
264 static const struct block_device_operations mtd_blktrans_ops
= {
265 .owner
= THIS_MODULE
,
266 .open
= blktrans_open
,
267 .release
= blktrans_release
,
268 .ioctl
= blktrans_ioctl
,
269 .getgeo
= blktrans_getgeo
,
272 int add_mtd_blktrans_dev(struct mtd_blktrans_dev
*new)
274 struct mtd_blktrans_ops
*tr
= new->tr
;
275 struct mtd_blktrans_dev
*d
;
276 int last_devnum
= -1;
280 if (mutex_trylock(&mtd_table_mutex
)) {
281 mutex_unlock(&mtd_table_mutex
);
285 mutex_lock(&blktrans_ref_mutex
);
286 list_for_each_entry(d
, &tr
->devs
, list
) {
287 if (new->devnum
== -1) {
288 /* Use first free number */
289 if (d
->devnum
!= last_devnum
+1) {
290 /* Found a free devnum. Plug it in here */
291 new->devnum
= last_devnum
+1;
292 list_add_tail(&new->list
, &d
->list
);
295 } else if (d
->devnum
== new->devnum
) {
296 /* Required number taken */
297 mutex_unlock(&blktrans_ref_mutex
);
299 } else if (d
->devnum
> new->devnum
) {
300 /* Required number was free */
301 list_add_tail(&new->list
, &d
->list
);
304 last_devnum
= d
->devnum
;
308 if (new->devnum
== -1)
309 new->devnum
= last_devnum
+1;
311 /* Check that the device and any partitions will get valid
312 * minor numbers and that the disk naming code below can cope
313 * with this number. */
314 if (new->devnum
> (MINORMASK
>> tr
->part_bits
) ||
315 (tr
->part_bits
&& new->devnum
>= 27 * 26)) {
316 mutex_unlock(&blktrans_ref_mutex
);
320 list_add_tail(&new->list
, &tr
->devs
);
322 mutex_unlock(&blktrans_ref_mutex
);
324 mutex_init(&new->lock
);
325 kref_init(&new->ref
);
331 gd
= alloc_disk(1 << tr
->part_bits
);
337 gd
->private_data
= new;
338 gd
->major
= tr
->major
;
339 gd
->first_minor
= (new->devnum
) << tr
->part_bits
;
340 gd
->fops
= &mtd_blktrans_ops
;
343 if (new->devnum
< 26)
344 snprintf(gd
->disk_name
, sizeof(gd
->disk_name
),
345 "%s%c", tr
->name
, 'a' + new->devnum
);
347 snprintf(gd
->disk_name
, sizeof(gd
->disk_name
),
349 'a' - 1 + new->devnum
/ 26,
350 'a' + new->devnum
% 26);
352 snprintf(gd
->disk_name
, sizeof(gd
->disk_name
),
353 "%s%d", tr
->name
, new->devnum
);
355 set_capacity(gd
, (new->size
* tr
->blksize
) >> 9);
357 /* Create the request queue */
358 spin_lock_init(&new->queue_lock
);
359 new->rq
= blk_init_queue(mtd_blktrans_request
, &new->queue_lock
);
364 new->rq
->queuedata
= new;
365 blk_queue_logical_block_size(new->rq
, tr
->blksize
);
368 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
,
373 __get_mtd_device(new->mtd
);
374 __module_get(tr
->owner
);
376 /* Create processing thread */
377 /* TODO: workqueue ? */
378 new->thread
= kthread_run(mtd_blktrans_thread
, new,
379 "%s%d", tr
->name
, new->mtd
->index
);
380 if (IS_ERR(new->thread
)) {
381 ret
= PTR_ERR(new->thread
);
384 gd
->driverfs_dev
= &new->mtd
->dev
;
391 if (new->disk_attributes
) {
392 ret
= sysfs_create_group(&disk_to_dev(gd
)->kobj
,
393 new->disk_attributes
);
398 module_put(tr
->owner
);
399 __put_mtd_device(new->mtd
);
400 blk_cleanup_queue(new->rq
);
404 list_del(&new->list
);
410 int del_mtd_blktrans_dev(struct mtd_blktrans_dev
*old
)
414 if (mutex_trylock(&mtd_table_mutex
)) {
415 mutex_unlock(&mtd_table_mutex
);
419 /* Stop new requests to arrive */
420 del_gendisk(old
->disk
);
422 if (old
->disk_attributes
)
423 sysfs_remove_group(&disk_to_dev(old
->disk
)->kobj
,
424 old
->disk_attributes
);
426 /* Stop the thread */
427 kthread_stop(old
->thread
);
429 /* Kill current requests */
430 spin_lock_irqsave(&old
->queue_lock
, flags
);
431 old
->rq
->queuedata
= NULL
;
432 blk_start_queue(old
->rq
);
433 spin_unlock_irqrestore(&old
->queue_lock
, flags
);
435 /* Ask trans driver for release to the mtd device */
436 mutex_lock(&old
->lock
);
437 if (old
->open
&& old
->tr
->release
) {
438 old
->tr
->release(old
);
442 __put_mtd_device(old
->mtd
);
443 module_put(old
->tr
->owner
);
445 /* At that point, we don't touch the mtd anymore */
448 mutex_unlock(&old
->lock
);
449 blktrans_dev_put(old
);
453 static void blktrans_notify_remove(struct mtd_info
*mtd
)
455 struct mtd_blktrans_ops
*tr
;
456 struct mtd_blktrans_dev
*dev
, *next
;
458 list_for_each_entry(tr
, &blktrans_majors
, list
)
459 list_for_each_entry_safe(dev
, next
, &tr
->devs
, list
)
464 static void blktrans_notify_add(struct mtd_info
*mtd
)
466 struct mtd_blktrans_ops
*tr
;
468 if (mtd
->type
== MTD_ABSENT
)
471 list_for_each_entry(tr
, &blktrans_majors
, list
)
472 tr
->add_mtd(tr
, mtd
);
475 static struct mtd_notifier blktrans_notifier
= {
476 .add
= blktrans_notify_add
,
477 .remove
= blktrans_notify_remove
,
480 int register_mtd_blktrans(struct mtd_blktrans_ops
*tr
)
482 struct mtd_info
*mtd
;
485 /* Register the notifier if/when the first device type is
486 registered, to prevent the link/init ordering from fucking
488 if (!blktrans_notifier
.list
.next
)
489 register_mtd_user(&blktrans_notifier
);
492 mutex_lock(&mtd_table_mutex
);
494 ret
= register_blkdev(tr
->major
, tr
->name
);
496 printk(KERN_WARNING
"Unable to register %s block device on major %d: %d\n",
497 tr
->name
, tr
->major
, ret
);
498 mutex_unlock(&mtd_table_mutex
);
502 tr
->blkshift
= ffs(tr
->blksize
) - 1;
504 INIT_LIST_HEAD(&tr
->devs
);
505 list_add(&tr
->list
, &blktrans_majors
);
507 mtd_for_each_device(mtd
)
508 if (mtd
->type
!= MTD_ABSENT
)
509 tr
->add_mtd(tr
, mtd
);
511 mutex_unlock(&mtd_table_mutex
);
515 int deregister_mtd_blktrans(struct mtd_blktrans_ops
*tr
)
517 struct mtd_blktrans_dev
*dev
, *next
;
519 mutex_lock(&mtd_table_mutex
);
521 /* Remove it from the list of active majors */
524 list_for_each_entry_safe(dev
, next
, &tr
->devs
, list
)
527 unregister_blkdev(tr
->major
, tr
->name
);
528 mutex_unlock(&mtd_table_mutex
);
530 BUG_ON(!list_empty(&tr
->devs
));
534 static void __exit
mtd_blktrans_exit(void)
536 /* No race here -- if someone's currently in register_mtd_blktrans
537 we're screwed anyway. */
538 if (blktrans_notifier
.list
.next
)
539 unregister_mtd_user(&blktrans_notifier
);
542 module_exit(mtd_blktrans_exit
);
544 EXPORT_SYMBOL_GPL(register_mtd_blktrans
);
545 EXPORT_SYMBOL_GPL(deregister_mtd_blktrans
);
546 EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev
);
547 EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev
);
549 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
550 MODULE_LICENSE("GPL");
551 MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'");