Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * (C) 2003 David Woodhouse <dwmw2@infradead.org> |
3 | * | |
4 | * Interface to Linux 2.5 block layer for MTD 'translation layers'. | |
5 | * | |
6 | */ | |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/slab.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/list.h> | |
12 | #include <linux/fs.h> | |
13 | #include <linux/mtd/blktrans.h> | |
14 | #include <linux/mtd/mtd.h> | |
15 | #include <linux/blkdev.h> | |
16 | #include <linux/blkpg.h> | |
83144186 | 17 | #include <linux/freezer.h> |
1da177e4 LT |
18 | #include <linux/spinlock.h> |
19 | #include <linux/hdreg.h> | |
20 | #include <linux/init.h> | |
48b19268 | 21 | #include <linux/mutex.h> |
99f9b243 | 22 | #include <linux/kthread.h> |
1da177e4 | 23 | #include <asm/uaccess.h> |
1da177e4 | 24 | |
356d70f1 | 25 | #include "mtdcore.h" |
1da177e4 | 26 | |
356d70f1 | 27 | static LIST_HEAD(blktrans_majors); |
1da177e4 LT |
28 | |
29 | struct mtd_blkcore_priv { | |
3e67fe45 | 30 | struct task_struct *thread; |
1da177e4 LT |
31 | struct request_queue *rq; |
32 | spinlock_t queue_lock; | |
33 | }; | |
34 | ||
35 | static int do_blktrans_request(struct mtd_blktrans_ops *tr, | |
36 | struct mtd_blktrans_dev *dev, | |
37 | struct request *req) | |
38 | { | |
39 | unsigned long block, nsect; | |
40 | char *buf; | |
41 | ||
83096ebf | 42 | block = blk_rq_pos(req) << 9 >> tr->blkshift; |
1011c1b9 | 43 | nsect = blk_rq_cur_bytes(req) >> tr->blkshift; |
19187672 | 44 | |
1da177e4 LT |
45 | buf = req->buffer; |
46 | ||
4aff5e23 | 47 | if (!blk_fs_request(req)) |
f06d9a2b | 48 | return -EIO; |
1da177e4 | 49 | |
83096ebf TH |
50 | if (blk_rq_pos(req) + blk_rq_cur_sectors(req) > |
51 | get_capacity(req->rq_disk)) | |
f06d9a2b | 52 | return -EIO; |
1da177e4 | 53 | |
c15227de CH |
54 | if (blk_discard_rq(req)) |
55 | return tr->discard(dev, block, nsect); | |
56 | ||
1da177e4 LT |
57 | switch(rq_data_dir(req)) { |
58 | case READ: | |
19187672 | 59 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 60 | if (tr->readsect(dev, block, buf)) |
f06d9a2b TH |
61 | return -EIO; |
62 | return 0; | |
1da177e4 LT |
63 | |
64 | case WRITE: | |
65 | if (!tr->writesect) | |
f06d9a2b | 66 | return -EIO; |
1da177e4 | 67 | |
19187672 | 68 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 69 | if (tr->writesect(dev, block, buf)) |
f06d9a2b TH |
70 | return -EIO; |
71 | return 0; | |
1da177e4 LT |
72 | |
73 | default: | |
9a292308 | 74 | printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req)); |
f06d9a2b | 75 | return -EIO; |
1da177e4 LT |
76 | } |
77 | } | |
78 | ||
79 | static int mtd_blktrans_thread(void *arg) | |
80 | { | |
81 | struct mtd_blktrans_ops *tr = arg; | |
82 | struct request_queue *rq = tr->blkcore_priv->rq; | |
1498ada7 | 83 | struct request *req = NULL; |
1da177e4 LT |
84 | |
85 | /* we might get involved when memory gets low, so use PF_MEMALLOC */ | |
83144186 | 86 | current->flags |= PF_MEMALLOC; |
1da177e4 | 87 | |
1da177e4 | 88 | spin_lock_irq(rq->queue_lock); |
1498ada7 | 89 | |
3e67fe45 | 90 | while (!kthread_should_stop()) { |
1da177e4 | 91 | struct mtd_blktrans_dev *dev; |
f06d9a2b | 92 | int res; |
1da177e4 | 93 | |
9934c8c0 | 94 | if (!req && !(req = blk_fetch_request(rq))) { |
1da177e4 | 95 | set_current_state(TASK_INTERRUPTIBLE); |
1da177e4 | 96 | spin_unlock_irq(rq->queue_lock); |
1da177e4 | 97 | schedule(); |
1da177e4 | 98 | spin_lock_irq(rq->queue_lock); |
1da177e4 LT |
99 | continue; |
100 | } | |
101 | ||
102 | dev = req->rq_disk->private_data; | |
103 | tr = dev->tr; | |
104 | ||
105 | spin_unlock_irq(rq->queue_lock); | |
106 | ||
48b19268 | 107 | mutex_lock(&dev->lock); |
1da177e4 | 108 | res = do_blktrans_request(tr, dev, req); |
48b19268 | 109 | mutex_unlock(&dev->lock); |
1da177e4 LT |
110 | |
111 | spin_lock_irq(rq->queue_lock); | |
112 | ||
1498ada7 TH |
113 | if (!__blk_end_request_cur(req, res)) |
114 | req = NULL; | |
1da177e4 | 115 | } |
1498ada7 TH |
116 | |
117 | if (req) | |
118 | __blk_end_request_all(req, -EIO); | |
119 | ||
1da177e4 LT |
120 | spin_unlock_irq(rq->queue_lock); |
121 | ||
3e67fe45 | 122 | return 0; |
1da177e4 LT |
123 | } |
124 | ||
125 | static void mtd_blktrans_request(struct request_queue *rq) | |
126 | { | |
127 | struct mtd_blktrans_ops *tr = rq->queuedata; | |
3e67fe45 | 128 | wake_up_process(tr->blkcore_priv->thread); |
1da177e4 LT |
129 | } |
130 | ||
131 | ||
af0e2a0a | 132 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 133 | { |
af0e2a0a AV |
134 | struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data; |
135 | struct mtd_blktrans_ops *tr = dev->tr; | |
1da177e4 LT |
136 | int ret = -ENODEV; |
137 | ||
8022c13c | 138 | if (!get_mtd_device(NULL, dev->mtd->index)) |
1da177e4 LT |
139 | goto out; |
140 | ||
141 | if (!try_module_get(tr->owner)) | |
142 | goto out_tr; | |
143 | ||
97894cda | 144 | /* FIXME: Locking. A hot pluggable device can go away |
1da177e4 LT |
145 | (del_mtd_device can be called for it) without its module |
146 | being unloaded. */ | |
147 | dev->mtd->usecount++; | |
148 | ||
149 | ret = 0; | |
150 | if (tr->open && (ret = tr->open(dev))) { | |
151 | dev->mtd->usecount--; | |
8022c13c | 152 | put_mtd_device(dev->mtd); |
1da177e4 LT |
153 | out_tr: |
154 | module_put(tr->owner); | |
155 | } | |
156 | out: | |
157 | return ret; | |
158 | } | |
159 | ||
af0e2a0a | 160 | static int blktrans_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 161 | { |
af0e2a0a AV |
162 | struct mtd_blktrans_dev *dev = disk->private_data; |
163 | struct mtd_blktrans_ops *tr = dev->tr; | |
1da177e4 LT |
164 | int ret = 0; |
165 | ||
1da177e4 LT |
166 | if (tr->release) |
167 | ret = tr->release(dev); | |
168 | ||
169 | if (!ret) { | |
170 | dev->mtd->usecount--; | |
8022c13c | 171 | put_mtd_device(dev->mtd); |
1da177e4 LT |
172 | module_put(tr->owner); |
173 | } | |
174 | ||
175 | return ret; | |
176 | } | |
177 | ||
a885c8c4 CH |
178 | static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
179 | { | |
180 | struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data; | |
181 | ||
182 | if (dev->tr->getgeo) | |
183 | return dev->tr->getgeo(dev, geo); | |
184 | return -ENOTTY; | |
185 | } | |
1da177e4 | 186 | |
af0e2a0a | 187 | static int blktrans_ioctl(struct block_device *bdev, fmode_t mode, |
1da177e4 LT |
188 | unsigned int cmd, unsigned long arg) |
189 | { | |
af0e2a0a | 190 | struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data; |
1da177e4 LT |
191 | struct mtd_blktrans_ops *tr = dev->tr; |
192 | ||
193 | switch (cmd) { | |
194 | case BLKFLSBUF: | |
195 | if (tr->flush) | |
196 | return tr->flush(dev); | |
197 | /* The core code did the work, we had nothing to do. */ | |
198 | return 0; | |
1da177e4 LT |
199 | default: |
200 | return -ENOTTY; | |
201 | } | |
202 | } | |
203 | ||
83d5cde4 | 204 | static const struct block_device_operations mtd_blktrans_ops = { |
1da177e4 | 205 | .owner = THIS_MODULE, |
af0e2a0a AV |
206 | .open = blktrans_open, |
207 | .release = blktrans_release, | |
208 | .locked_ioctl = blktrans_ioctl, | |
a885c8c4 | 209 | .getgeo = blktrans_getgeo, |
1da177e4 LT |
210 | }; |
211 | ||
212 | int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) | |
213 | { | |
214 | struct mtd_blktrans_ops *tr = new->tr; | |
71a928c0 | 215 | struct mtd_blktrans_dev *d; |
1da177e4 LT |
216 | int last_devnum = -1; |
217 | struct gendisk *gd; | |
218 | ||
b3561ea9 | 219 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 220 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
221 | BUG(); |
222 | } | |
223 | ||
71a928c0 | 224 | list_for_each_entry(d, &tr->devs, list) { |
1da177e4 LT |
225 | if (new->devnum == -1) { |
226 | /* Use first free number */ | |
227 | if (d->devnum != last_devnum+1) { | |
228 | /* Found a free devnum. Plug it in here */ | |
229 | new->devnum = last_devnum+1; | |
230 | list_add_tail(&new->list, &d->list); | |
231 | goto added; | |
232 | } | |
233 | } else if (d->devnum == new->devnum) { | |
234 | /* Required number taken */ | |
235 | return -EBUSY; | |
236 | } else if (d->devnum > new->devnum) { | |
237 | /* Required number was free */ | |
238 | list_add_tail(&new->list, &d->list); | |
239 | goto added; | |
97894cda | 240 | } |
1da177e4 LT |
241 | last_devnum = d->devnum; |
242 | } | |
243 | if (new->devnum == -1) | |
244 | new->devnum = last_devnum+1; | |
245 | ||
246 | if ((new->devnum << tr->part_bits) > 256) { | |
247 | return -EBUSY; | |
248 | } | |
249 | ||
1da177e4 LT |
250 | list_add_tail(&new->list, &tr->devs); |
251 | added: | |
ce37ab42 | 252 | mutex_init(&new->lock); |
1da177e4 LT |
253 | if (!tr->writesect) |
254 | new->readonly = 1; | |
255 | ||
256 | gd = alloc_disk(1 << tr->part_bits); | |
257 | if (!gd) { | |
258 | list_del(&new->list); | |
259 | return -ENOMEM; | |
260 | } | |
261 | gd->major = tr->major; | |
262 | gd->first_minor = (new->devnum) << tr->part_bits; | |
263 | gd->fops = &mtd_blktrans_ops; | |
97894cda | 264 | |
65a8de36 TP |
265 | if (tr->part_bits) |
266 | if (new->devnum < 26) | |
267 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
268 | "%s%c", tr->name, 'a' + new->devnum); | |
269 | else | |
270 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
271 | "%s%c%c", tr->name, | |
272 | 'a' - 1 + new->devnum / 26, | |
273 | 'a' + new->devnum % 26); | |
274 | else | |
275 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
276 | "%s%d", tr->name, new->devnum); | |
1da177e4 LT |
277 | |
278 | /* 2.5 has capacity in units of 512 bytes while still | |
279 | having BLOCK_SIZE_BITS set to 10. Just to keep us amused. */ | |
19187672 | 280 | set_capacity(gd, (new->size * tr->blksize) >> 9); |
1da177e4 LT |
281 | |
282 | gd->private_data = new; | |
283 | new->blkcore_priv = gd; | |
284 | gd->queue = tr->blkcore_priv->rq; | |
d694846b | 285 | gd->driverfs_dev = &new->mtd->dev; |
1da177e4 LT |
286 | |
287 | if (new->readonly) | |
288 | set_disk_ro(gd, 1); | |
289 | ||
290 | add_disk(gd); | |
97894cda | 291 | |
1da177e4 LT |
292 | return 0; |
293 | } | |
294 | ||
295 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
296 | { | |
b3561ea9 | 297 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 298 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
299 | BUG(); |
300 | } | |
301 | ||
302 | list_del(&old->list); | |
303 | ||
304 | del_gendisk(old->blkcore_priv); | |
305 | put_disk(old->blkcore_priv); | |
97894cda | 306 | |
1da177e4 LT |
307 | return 0; |
308 | } | |
309 | ||
310 | static void blktrans_notify_remove(struct mtd_info *mtd) | |
311 | { | |
71a928c0 CM |
312 | struct mtd_blktrans_ops *tr; |
313 | struct mtd_blktrans_dev *dev, *next; | |
1da177e4 | 314 | |
71a928c0 CM |
315 | list_for_each_entry(tr, &blktrans_majors, list) |
316 | list_for_each_entry_safe(dev, next, &tr->devs, list) | |
1da177e4 LT |
317 | if (dev->mtd == mtd) |
318 | tr->remove_dev(dev); | |
1da177e4 LT |
319 | } |
320 | ||
321 | static void blktrans_notify_add(struct mtd_info *mtd) | |
322 | { | |
71a928c0 | 323 | struct mtd_blktrans_ops *tr; |
1da177e4 LT |
324 | |
325 | if (mtd->type == MTD_ABSENT) | |
326 | return; | |
327 | ||
71a928c0 | 328 | list_for_each_entry(tr, &blktrans_majors, list) |
1da177e4 | 329 | tr->add_mtd(tr, mtd); |
1da177e4 LT |
330 | } |
331 | ||
332 | static struct mtd_notifier blktrans_notifier = { | |
333 | .add = blktrans_notify_add, | |
334 | .remove = blktrans_notify_remove, | |
335 | }; | |
97894cda | 336 | |
1da177e4 LT |
337 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
338 | { | |
339 | int ret, i; | |
340 | ||
97894cda | 341 | /* Register the notifier if/when the first device type is |
1da177e4 LT |
342 | registered, to prevent the link/init ordering from fucking |
343 | us over. */ | |
344 | if (!blktrans_notifier.list.next) | |
345 | register_mtd_user(&blktrans_notifier); | |
346 | ||
95b93a0c | 347 | tr->blkcore_priv = kzalloc(sizeof(*tr->blkcore_priv), GFP_KERNEL); |
1da177e4 LT |
348 | if (!tr->blkcore_priv) |
349 | return -ENOMEM; | |
350 | ||
48b19268 | 351 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
352 | |
353 | ret = register_blkdev(tr->major, tr->name); | |
354 | if (ret) { | |
355 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", | |
356 | tr->name, tr->major, ret); | |
357 | kfree(tr->blkcore_priv); | |
48b19268 | 358 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
359 | return ret; |
360 | } | |
361 | spin_lock_init(&tr->blkcore_priv->queue_lock); | |
1da177e4 LT |
362 | |
363 | tr->blkcore_priv->rq = blk_init_queue(mtd_blktrans_request, &tr->blkcore_priv->queue_lock); | |
364 | if (!tr->blkcore_priv->rq) { | |
365 | unregister_blkdev(tr->major, tr->name); | |
366 | kfree(tr->blkcore_priv); | |
48b19268 | 367 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
368 | return -ENOMEM; |
369 | } | |
370 | ||
371 | tr->blkcore_priv->rq->queuedata = tr; | |
e1defc4f | 372 | blk_queue_logical_block_size(tr->blkcore_priv->rq, tr->blksize); |
eae9acd1 | 373 | if (tr->discard) |
c15227de CH |
374 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, |
375 | tr->blkcore_priv->rq); | |
eae9acd1 | 376 | |
19187672 | 377 | tr->blkshift = ffs(tr->blksize) - 1; |
1da177e4 | 378 | |
3e67fe45 CH |
379 | tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr, |
380 | "%sd", tr->name); | |
381 | if (IS_ERR(tr->blkcore_priv->thread)) { | |
2cf3a114 | 382 | int ret = PTR_ERR(tr->blkcore_priv->thread); |
1da177e4 LT |
383 | blk_cleanup_queue(tr->blkcore_priv->rq); |
384 | unregister_blkdev(tr->major, tr->name); | |
385 | kfree(tr->blkcore_priv); | |
48b19268 | 386 | mutex_unlock(&mtd_table_mutex); |
2cf3a114 | 387 | return ret; |
97894cda | 388 | } |
1da177e4 | 389 | |
1da177e4 LT |
390 | INIT_LIST_HEAD(&tr->devs); |
391 | list_add(&tr->list, &blktrans_majors); | |
392 | ||
393 | for (i=0; i<MAX_MTD_DEVICES; i++) { | |
394 | if (mtd_table[i] && mtd_table[i]->type != MTD_ABSENT) | |
395 | tr->add_mtd(tr, mtd_table[i]); | |
396 | } | |
397 | ||
48b19268 | 398 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
399 | |
400 | return 0; | |
401 | } | |
402 | ||
403 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) | |
404 | { | |
71a928c0 | 405 | struct mtd_blktrans_dev *dev, *next; |
1da177e4 | 406 | |
48b19268 | 407 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
408 | |
409 | /* Clean up the kernel thread */ | |
3e67fe45 | 410 | kthread_stop(tr->blkcore_priv->thread); |
1da177e4 LT |
411 | |
412 | /* Remove it from the list of active majors */ | |
413 | list_del(&tr->list); | |
414 | ||
71a928c0 | 415 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
1da177e4 | 416 | tr->remove_dev(dev); |
1da177e4 | 417 | |
1da177e4 LT |
418 | blk_cleanup_queue(tr->blkcore_priv->rq); |
419 | unregister_blkdev(tr->major, tr->name); | |
420 | ||
48b19268 | 421 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
422 | |
423 | kfree(tr->blkcore_priv); | |
424 | ||
373ebfbf | 425 | BUG_ON(!list_empty(&tr->devs)); |
1da177e4 LT |
426 | return 0; |
427 | } | |
428 | ||
429 | static void __exit mtd_blktrans_exit(void) | |
430 | { | |
431 | /* No race here -- if someone's currently in register_mtd_blktrans | |
432 | we're screwed anyway. */ | |
433 | if (blktrans_notifier.list.next) | |
434 | unregister_mtd_user(&blktrans_notifier); | |
435 | } | |
436 | ||
437 | module_exit(mtd_blktrans_exit); | |
438 | ||
439 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); | |
440 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); | |
441 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); | |
442 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); | |
443 | ||
444 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
445 | MODULE_LICENSE("GPL"); | |
446 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |