Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
97894cda | 2 | * $Id: mtd_blkdevs.c,v 1.27 2005/11/07 11:14:20 gleixner Exp $ |
1da177e4 LT |
3 | * |
4 | * (C) 2003 David Woodhouse <dwmw2@infradead.org> | |
5 | * | |
6 | * Interface to Linux 2.5 block layer for MTD 'translation layers'. | |
7 | * | |
8 | */ | |
9 | ||
10 | #include <linux/kernel.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/list.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/mtd/blktrans.h> | |
16 | #include <linux/mtd/mtd.h> | |
17 | #include <linux/blkdev.h> | |
18 | #include <linux/blkpg.h> | |
19 | #include <linux/spinlock.h> | |
20 | #include <linux/hdreg.h> | |
21 | #include <linux/init.h> | |
48b19268 | 22 | #include <linux/mutex.h> |
1da177e4 | 23 | #include <asm/uaccess.h> |
1da177e4 LT |
24 | |
25 | static LIST_HEAD(blktrans_majors); | |
26 | ||
48b19268 | 27 | extern struct mutex mtd_table_mutex; |
1da177e4 LT |
28 | extern struct mtd_info *mtd_table[]; |
29 | ||
30 | struct mtd_blkcore_priv { | |
31 | struct completion thread_dead; | |
32 | int exiting; | |
33 | wait_queue_head_t thread_wq; | |
34 | struct request_queue *rq; | |
35 | spinlock_t queue_lock; | |
36 | }; | |
37 | ||
38 | static int do_blktrans_request(struct mtd_blktrans_ops *tr, | |
39 | struct mtd_blktrans_dev *dev, | |
40 | struct request *req) | |
41 | { | |
42 | unsigned long block, nsect; | |
43 | char *buf; | |
44 | ||
45 | block = req->sector; | |
46 | nsect = req->current_nr_sectors; | |
47 | buf = req->buffer; | |
48 | ||
49 | if (!(req->flags & REQ_CMD)) | |
50 | return 0; | |
51 | ||
52 | if (block + nsect > get_capacity(req->rq_disk)) | |
53 | return 0; | |
54 | ||
55 | switch(rq_data_dir(req)) { | |
56 | case READ: | |
57 | for (; nsect > 0; nsect--, block++, buf += 512) | |
58 | if (tr->readsect(dev, block, buf)) | |
59 | return 0; | |
60 | return 1; | |
61 | ||
62 | case WRITE: | |
63 | if (!tr->writesect) | |
64 | return 0; | |
65 | ||
66 | for (; nsect > 0; nsect--, block++, buf += 512) | |
67 | if (tr->writesect(dev, block, buf)) | |
68 | return 0; | |
69 | return 1; | |
70 | ||
71 | default: | |
72 | printk(KERN_NOTICE "Unknown request %ld\n", rq_data_dir(req)); | |
73 | return 0; | |
74 | } | |
75 | } | |
76 | ||
77 | static int mtd_blktrans_thread(void *arg) | |
78 | { | |
79 | struct mtd_blktrans_ops *tr = arg; | |
80 | struct request_queue *rq = tr->blkcore_priv->rq; | |
81 | ||
82 | /* we might get involved when memory gets low, so use PF_MEMALLOC */ | |
83 | current->flags |= PF_MEMALLOC | PF_NOFREEZE; | |
84 | ||
85 | daemonize("%sd", tr->name); | |
86 | ||
87 | /* daemonize() doesn't do this for us since some kernel threads | |
97894cda | 88 | actually want to deal with signals. We can't just call |
1da177e4 LT |
89 | exit_sighand() since that'll cause an oops when we finally |
90 | do exit. */ | |
91 | spin_lock_irq(¤t->sighand->siglock); | |
92 | sigfillset(¤t->blocked); | |
93 | recalc_sigpending(); | |
94 | spin_unlock_irq(¤t->sighand->siglock); | |
95 | ||
96 | spin_lock_irq(rq->queue_lock); | |
97894cda | 97 | |
1da177e4 LT |
98 | while (!tr->blkcore_priv->exiting) { |
99 | struct request *req; | |
100 | struct mtd_blktrans_dev *dev; | |
101 | int res = 0; | |
102 | DECLARE_WAITQUEUE(wait, current); | |
103 | ||
104 | req = elv_next_request(rq); | |
105 | ||
106 | if (!req) { | |
107 | add_wait_queue(&tr->blkcore_priv->thread_wq, &wait); | |
108 | set_current_state(TASK_INTERRUPTIBLE); | |
109 | ||
110 | spin_unlock_irq(rq->queue_lock); | |
111 | ||
112 | schedule(); | |
113 | remove_wait_queue(&tr->blkcore_priv->thread_wq, &wait); | |
114 | ||
115 | spin_lock_irq(rq->queue_lock); | |
116 | ||
117 | continue; | |
118 | } | |
119 | ||
120 | dev = req->rq_disk->private_data; | |
121 | tr = dev->tr; | |
122 | ||
123 | spin_unlock_irq(rq->queue_lock); | |
124 | ||
48b19268 | 125 | mutex_lock(&dev->lock); |
1da177e4 | 126 | res = do_blktrans_request(tr, dev, req); |
48b19268 | 127 | mutex_unlock(&dev->lock); |
1da177e4 LT |
128 | |
129 | spin_lock_irq(rq->queue_lock); | |
130 | ||
131 | end_request(req, res); | |
132 | } | |
133 | spin_unlock_irq(rq->queue_lock); | |
134 | ||
135 | complete_and_exit(&tr->blkcore_priv->thread_dead, 0); | |
136 | } | |
137 | ||
138 | static void mtd_blktrans_request(struct request_queue *rq) | |
139 | { | |
140 | struct mtd_blktrans_ops *tr = rq->queuedata; | |
141 | wake_up(&tr->blkcore_priv->thread_wq); | |
142 | } | |
143 | ||
144 | ||
145 | static int blktrans_open(struct inode *i, struct file *f) | |
146 | { | |
147 | struct mtd_blktrans_dev *dev; | |
148 | struct mtd_blktrans_ops *tr; | |
149 | int ret = -ENODEV; | |
150 | ||
151 | dev = i->i_bdev->bd_disk->private_data; | |
152 | tr = dev->tr; | |
153 | ||
154 | if (!try_module_get(dev->mtd->owner)) | |
155 | goto out; | |
156 | ||
157 | if (!try_module_get(tr->owner)) | |
158 | goto out_tr; | |
159 | ||
97894cda | 160 | /* FIXME: Locking. A hot pluggable device can go away |
1da177e4 LT |
161 | (del_mtd_device can be called for it) without its module |
162 | being unloaded. */ | |
163 | dev->mtd->usecount++; | |
164 | ||
165 | ret = 0; | |
166 | if (tr->open && (ret = tr->open(dev))) { | |
167 | dev->mtd->usecount--; | |
168 | module_put(dev->mtd->owner); | |
169 | out_tr: | |
170 | module_put(tr->owner); | |
171 | } | |
172 | out: | |
173 | return ret; | |
174 | } | |
175 | ||
176 | static int blktrans_release(struct inode *i, struct file *f) | |
177 | { | |
178 | struct mtd_blktrans_dev *dev; | |
179 | struct mtd_blktrans_ops *tr; | |
180 | int ret = 0; | |
181 | ||
182 | dev = i->i_bdev->bd_disk->private_data; | |
183 | tr = dev->tr; | |
184 | ||
185 | if (tr->release) | |
186 | ret = tr->release(dev); | |
187 | ||
188 | if (!ret) { | |
189 | dev->mtd->usecount--; | |
190 | module_put(dev->mtd->owner); | |
191 | module_put(tr->owner); | |
192 | } | |
193 | ||
194 | return ret; | |
195 | } | |
196 | ||
a885c8c4 CH |
197 | static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
198 | { | |
199 | struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data; | |
200 | ||
201 | if (dev->tr->getgeo) | |
202 | return dev->tr->getgeo(dev, geo); | |
203 | return -ENOTTY; | |
204 | } | |
1da177e4 | 205 | |
97894cda | 206 | static int blktrans_ioctl(struct inode *inode, struct file *file, |
1da177e4 LT |
207 | unsigned int cmd, unsigned long arg) |
208 | { | |
209 | struct mtd_blktrans_dev *dev = inode->i_bdev->bd_disk->private_data; | |
210 | struct mtd_blktrans_ops *tr = dev->tr; | |
211 | ||
212 | switch (cmd) { | |
213 | case BLKFLSBUF: | |
214 | if (tr->flush) | |
215 | return tr->flush(dev); | |
216 | /* The core code did the work, we had nothing to do. */ | |
217 | return 0; | |
1da177e4 LT |
218 | default: |
219 | return -ENOTTY; | |
220 | } | |
221 | } | |
222 | ||
223 | struct block_device_operations mtd_blktrans_ops = { | |
224 | .owner = THIS_MODULE, | |
225 | .open = blktrans_open, | |
226 | .release = blktrans_release, | |
227 | .ioctl = blktrans_ioctl, | |
a885c8c4 | 228 | .getgeo = blktrans_getgeo, |
1da177e4 LT |
229 | }; |
230 | ||
231 | int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) | |
232 | { | |
233 | struct mtd_blktrans_ops *tr = new->tr; | |
234 | struct list_head *this; | |
235 | int last_devnum = -1; | |
236 | struct gendisk *gd; | |
237 | ||
48b19268 IM |
238 | if (!!mutex_trylock(&mtd_table_mutex)) { |
239 | mutex_unlock(&mtd_table_mutex); | |
1da177e4 LT |
240 | BUG(); |
241 | } | |
242 | ||
243 | list_for_each(this, &tr->devs) { | |
244 | struct mtd_blktrans_dev *d = list_entry(this, struct mtd_blktrans_dev, list); | |
245 | if (new->devnum == -1) { | |
246 | /* Use first free number */ | |
247 | if (d->devnum != last_devnum+1) { | |
248 | /* Found a free devnum. Plug it in here */ | |
249 | new->devnum = last_devnum+1; | |
250 | list_add_tail(&new->list, &d->list); | |
251 | goto added; | |
252 | } | |
253 | } else if (d->devnum == new->devnum) { | |
254 | /* Required number taken */ | |
255 | return -EBUSY; | |
256 | } else if (d->devnum > new->devnum) { | |
257 | /* Required number was free */ | |
258 | list_add_tail(&new->list, &d->list); | |
259 | goto added; | |
97894cda | 260 | } |
1da177e4 LT |
261 | last_devnum = d->devnum; |
262 | } | |
263 | if (new->devnum == -1) | |
264 | new->devnum = last_devnum+1; | |
265 | ||
266 | if ((new->devnum << tr->part_bits) > 256) { | |
267 | return -EBUSY; | |
268 | } | |
269 | ||
48b19268 | 270 | mutex_init(&new->lock); |
1da177e4 LT |
271 | list_add_tail(&new->list, &tr->devs); |
272 | added: | |
273 | if (!tr->writesect) | |
274 | new->readonly = 1; | |
275 | ||
276 | gd = alloc_disk(1 << tr->part_bits); | |
277 | if (!gd) { | |
278 | list_del(&new->list); | |
279 | return -ENOMEM; | |
280 | } | |
281 | gd->major = tr->major; | |
282 | gd->first_minor = (new->devnum) << tr->part_bits; | |
283 | gd->fops = &mtd_blktrans_ops; | |
97894cda | 284 | |
65a8de36 TP |
285 | if (tr->part_bits) |
286 | if (new->devnum < 26) | |
287 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
288 | "%s%c", tr->name, 'a' + new->devnum); | |
289 | else | |
290 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
291 | "%s%c%c", tr->name, | |
292 | 'a' - 1 + new->devnum / 26, | |
293 | 'a' + new->devnum % 26); | |
294 | else | |
295 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
296 | "%s%d", tr->name, new->devnum); | |
1da177e4 LT |
297 | |
298 | /* 2.5 has capacity in units of 512 bytes while still | |
299 | having BLOCK_SIZE_BITS set to 10. Just to keep us amused. */ | |
300 | set_capacity(gd, (new->size * new->blksize) >> 9); | |
301 | ||
302 | gd->private_data = new; | |
303 | new->blkcore_priv = gd; | |
304 | gd->queue = tr->blkcore_priv->rq; | |
305 | ||
306 | if (new->readonly) | |
307 | set_disk_ro(gd, 1); | |
308 | ||
309 | add_disk(gd); | |
97894cda | 310 | |
1da177e4 LT |
311 | return 0; |
312 | } | |
313 | ||
314 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
315 | { | |
48b19268 IM |
316 | if (!!mutex_trylock(&mtd_table_mutex)) { |
317 | mutex_unlock(&mtd_table_mutex); | |
1da177e4 LT |
318 | BUG(); |
319 | } | |
320 | ||
321 | list_del(&old->list); | |
322 | ||
323 | del_gendisk(old->blkcore_priv); | |
324 | put_disk(old->blkcore_priv); | |
97894cda | 325 | |
1da177e4 LT |
326 | return 0; |
327 | } | |
328 | ||
329 | static void blktrans_notify_remove(struct mtd_info *mtd) | |
330 | { | |
331 | struct list_head *this, *this2, *next; | |
332 | ||
333 | list_for_each(this, &blktrans_majors) { | |
334 | struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list); | |
335 | ||
336 | list_for_each_safe(this2, next, &tr->devs) { | |
337 | struct mtd_blktrans_dev *dev = list_entry(this2, struct mtd_blktrans_dev, list); | |
338 | ||
339 | if (dev->mtd == mtd) | |
340 | tr->remove_dev(dev); | |
341 | } | |
342 | } | |
343 | } | |
344 | ||
345 | static void blktrans_notify_add(struct mtd_info *mtd) | |
346 | { | |
347 | struct list_head *this; | |
348 | ||
349 | if (mtd->type == MTD_ABSENT) | |
350 | return; | |
351 | ||
352 | list_for_each(this, &blktrans_majors) { | |
353 | struct mtd_blktrans_ops *tr = list_entry(this, struct mtd_blktrans_ops, list); | |
354 | ||
355 | tr->add_mtd(tr, mtd); | |
356 | } | |
357 | ||
358 | } | |
359 | ||
360 | static struct mtd_notifier blktrans_notifier = { | |
361 | .add = blktrans_notify_add, | |
362 | .remove = blktrans_notify_remove, | |
363 | }; | |
97894cda | 364 | |
1da177e4 LT |
365 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
366 | { | |
367 | int ret, i; | |
368 | ||
97894cda | 369 | /* Register the notifier if/when the first device type is |
1da177e4 LT |
370 | registered, to prevent the link/init ordering from fucking |
371 | us over. */ | |
372 | if (!blktrans_notifier.list.next) | |
373 | register_mtd_user(&blktrans_notifier); | |
374 | ||
375 | tr->blkcore_priv = kmalloc(sizeof(*tr->blkcore_priv), GFP_KERNEL); | |
376 | if (!tr->blkcore_priv) | |
377 | return -ENOMEM; | |
378 | ||
379 | memset(tr->blkcore_priv, 0, sizeof(*tr->blkcore_priv)); | |
380 | ||
48b19268 | 381 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
382 | |
383 | ret = register_blkdev(tr->major, tr->name); | |
384 | if (ret) { | |
385 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", | |
386 | tr->name, tr->major, ret); | |
387 | kfree(tr->blkcore_priv); | |
48b19268 | 388 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
389 | return ret; |
390 | } | |
391 | spin_lock_init(&tr->blkcore_priv->queue_lock); | |
392 | init_completion(&tr->blkcore_priv->thread_dead); | |
393 | init_waitqueue_head(&tr->blkcore_priv->thread_wq); | |
394 | ||
395 | tr->blkcore_priv->rq = blk_init_queue(mtd_blktrans_request, &tr->blkcore_priv->queue_lock); | |
396 | if (!tr->blkcore_priv->rq) { | |
397 | unregister_blkdev(tr->major, tr->name); | |
398 | kfree(tr->blkcore_priv); | |
48b19268 | 399 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
400 | return -ENOMEM; |
401 | } | |
402 | ||
403 | tr->blkcore_priv->rq->queuedata = tr; | |
404 | ||
405 | ret = kernel_thread(mtd_blktrans_thread, tr, CLONE_KERNEL); | |
406 | if (ret < 0) { | |
407 | blk_cleanup_queue(tr->blkcore_priv->rq); | |
408 | unregister_blkdev(tr->major, tr->name); | |
409 | kfree(tr->blkcore_priv); | |
48b19268 | 410 | mutex_unlock(&mtd_table_mutex); |
1da177e4 | 411 | return ret; |
97894cda | 412 | } |
1da177e4 | 413 | |
1da177e4 LT |
414 | INIT_LIST_HEAD(&tr->devs); |
415 | list_add(&tr->list, &blktrans_majors); | |
416 | ||
417 | for (i=0; i<MAX_MTD_DEVICES; i++) { | |
418 | if (mtd_table[i] && mtd_table[i]->type != MTD_ABSENT) | |
419 | tr->add_mtd(tr, mtd_table[i]); | |
420 | } | |
421 | ||
48b19268 | 422 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
423 | |
424 | return 0; | |
425 | } | |
426 | ||
427 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) | |
428 | { | |
429 | struct list_head *this, *next; | |
430 | ||
48b19268 | 431 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
432 | |
433 | /* Clean up the kernel thread */ | |
434 | tr->blkcore_priv->exiting = 1; | |
435 | wake_up(&tr->blkcore_priv->thread_wq); | |
436 | wait_for_completion(&tr->blkcore_priv->thread_dead); | |
437 | ||
438 | /* Remove it from the list of active majors */ | |
439 | list_del(&tr->list); | |
440 | ||
441 | list_for_each_safe(this, next, &tr->devs) { | |
442 | struct mtd_blktrans_dev *dev = list_entry(this, struct mtd_blktrans_dev, list); | |
443 | tr->remove_dev(dev); | |
444 | } | |
445 | ||
1da177e4 LT |
446 | blk_cleanup_queue(tr->blkcore_priv->rq); |
447 | unregister_blkdev(tr->major, tr->name); | |
448 | ||
48b19268 | 449 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
450 | |
451 | kfree(tr->blkcore_priv); | |
452 | ||
373ebfbf | 453 | BUG_ON(!list_empty(&tr->devs)); |
1da177e4 LT |
454 | return 0; |
455 | } | |
456 | ||
457 | static void __exit mtd_blktrans_exit(void) | |
458 | { | |
459 | /* No race here -- if someone's currently in register_mtd_blktrans | |
460 | we're screwed anyway. */ | |
461 | if (blktrans_notifier.list.next) | |
462 | unregister_mtd_user(&blktrans_notifier); | |
463 | } | |
464 | ||
465 | module_exit(mtd_blktrans_exit); | |
466 | ||
467 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); | |
468 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); | |
469 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); | |
470 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); | |
471 | ||
472 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
473 | MODULE_LICENSE("GPL"); | |
474 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |