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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 | ||
eae9acd1 DW |
35 | static int blktrans_discard_request(struct request_queue *q, |
36 | struct request *req) | |
37 | { | |
38 | req->cmd_type = REQ_TYPE_LINUX_BLOCK; | |
39 | req->cmd[0] = REQ_LB_OP_DISCARD; | |
40 | return 0; | |
41 | } | |
42 | ||
1da177e4 LT |
43 | static int do_blktrans_request(struct mtd_blktrans_ops *tr, |
44 | struct mtd_blktrans_dev *dev, | |
45 | struct request *req) | |
46 | { | |
47 | unsigned long block, nsect; | |
48 | char *buf; | |
49 | ||
19187672 RP |
50 | block = req->sector << 9 >> tr->blkshift; |
51 | nsect = req->current_nr_sectors << 9 >> tr->blkshift; | |
52 | ||
1da177e4 LT |
53 | buf = req->buffer; |
54 | ||
eae9acd1 DW |
55 | if (req->cmd_type == REQ_TYPE_LINUX_BLOCK && |
56 | req->cmd[0] == REQ_LB_OP_DISCARD) | |
f06d9a2b | 57 | return tr->discard(dev, block, nsect); |
eae9acd1 | 58 | |
4aff5e23 | 59 | if (!blk_fs_request(req)) |
f06d9a2b | 60 | return -EIO; |
1da177e4 | 61 | |
19187672 | 62 | if (req->sector + req->current_nr_sectors > get_capacity(req->rq_disk)) |
f06d9a2b | 63 | return -EIO; |
1da177e4 LT |
64 | |
65 | switch(rq_data_dir(req)) { | |
66 | case READ: | |
19187672 | 67 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 68 | if (tr->readsect(dev, block, buf)) |
f06d9a2b TH |
69 | return -EIO; |
70 | return 0; | |
1da177e4 LT |
71 | |
72 | case WRITE: | |
73 | if (!tr->writesect) | |
f06d9a2b | 74 | return -EIO; |
1da177e4 | 75 | |
19187672 | 76 | for (; nsect > 0; nsect--, block++, buf += tr->blksize) |
1da177e4 | 77 | if (tr->writesect(dev, block, buf)) |
f06d9a2b TH |
78 | return -EIO; |
79 | return 0; | |
1da177e4 LT |
80 | |
81 | default: | |
9a292308 | 82 | printk(KERN_NOTICE "Unknown request %u\n", rq_data_dir(req)); |
f06d9a2b | 83 | return -EIO; |
1da177e4 LT |
84 | } |
85 | } | |
86 | ||
87 | static int mtd_blktrans_thread(void *arg) | |
88 | { | |
89 | struct mtd_blktrans_ops *tr = arg; | |
90 | struct request_queue *rq = tr->blkcore_priv->rq; | |
91 | ||
92 | /* we might get involved when memory gets low, so use PF_MEMALLOC */ | |
83144186 | 93 | current->flags |= PF_MEMALLOC; |
1da177e4 | 94 | |
1da177e4 | 95 | spin_lock_irq(rq->queue_lock); |
3e67fe45 | 96 | while (!kthread_should_stop()) { |
1da177e4 LT |
97 | struct request *req; |
98 | struct mtd_blktrans_dev *dev; | |
f06d9a2b | 99 | int res; |
1da177e4 LT |
100 | |
101 | req = elv_next_request(rq); | |
102 | ||
103 | if (!req) { | |
1da177e4 | 104 | set_current_state(TASK_INTERRUPTIBLE); |
1da177e4 | 105 | spin_unlock_irq(rq->queue_lock); |
1da177e4 | 106 | schedule(); |
1da177e4 | 107 | spin_lock_irq(rq->queue_lock); |
1da177e4 LT |
108 | continue; |
109 | } | |
110 | ||
111 | dev = req->rq_disk->private_data; | |
112 | tr = dev->tr; | |
113 | ||
114 | spin_unlock_irq(rq->queue_lock); | |
115 | ||
48b19268 | 116 | mutex_lock(&dev->lock); |
1da177e4 | 117 | res = do_blktrans_request(tr, dev, req); |
48b19268 | 118 | mutex_unlock(&dev->lock); |
1da177e4 LT |
119 | |
120 | spin_lock_irq(rq->queue_lock); | |
121 | ||
f06d9a2b | 122 | __blk_end_request_cur(req, res); |
1da177e4 LT |
123 | } |
124 | spin_unlock_irq(rq->queue_lock); | |
125 | ||
3e67fe45 | 126 | return 0; |
1da177e4 LT |
127 | } |
128 | ||
129 | static void mtd_blktrans_request(struct request_queue *rq) | |
130 | { | |
131 | struct mtd_blktrans_ops *tr = rq->queuedata; | |
3e67fe45 | 132 | wake_up_process(tr->blkcore_priv->thread); |
1da177e4 LT |
133 | } |
134 | ||
135 | ||
af0e2a0a | 136 | static int blktrans_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 137 | { |
af0e2a0a AV |
138 | struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data; |
139 | struct mtd_blktrans_ops *tr = dev->tr; | |
1da177e4 LT |
140 | int ret = -ENODEV; |
141 | ||
1da177e4 LT |
142 | if (!try_module_get(dev->mtd->owner)) |
143 | goto out; | |
144 | ||
145 | if (!try_module_get(tr->owner)) | |
146 | goto out_tr; | |
147 | ||
97894cda | 148 | /* FIXME: Locking. A hot pluggable device can go away |
1da177e4 LT |
149 | (del_mtd_device can be called for it) without its module |
150 | being unloaded. */ | |
151 | dev->mtd->usecount++; | |
152 | ||
153 | ret = 0; | |
154 | if (tr->open && (ret = tr->open(dev))) { | |
155 | dev->mtd->usecount--; | |
156 | module_put(dev->mtd->owner); | |
157 | out_tr: | |
158 | module_put(tr->owner); | |
159 | } | |
160 | out: | |
161 | return ret; | |
162 | } | |
163 | ||
af0e2a0a | 164 | static int blktrans_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 165 | { |
af0e2a0a AV |
166 | struct mtd_blktrans_dev *dev = disk->private_data; |
167 | struct mtd_blktrans_ops *tr = dev->tr; | |
1da177e4 LT |
168 | int ret = 0; |
169 | ||
1da177e4 LT |
170 | if (tr->release) |
171 | ret = tr->release(dev); | |
172 | ||
173 | if (!ret) { | |
174 | dev->mtd->usecount--; | |
175 | module_put(dev->mtd->owner); | |
176 | module_put(tr->owner); | |
177 | } | |
178 | ||
179 | return ret; | |
180 | } | |
181 | ||
a885c8c4 CH |
182 | static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
183 | { | |
184 | struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data; | |
185 | ||
186 | if (dev->tr->getgeo) | |
187 | return dev->tr->getgeo(dev, geo); | |
188 | return -ENOTTY; | |
189 | } | |
1da177e4 | 190 | |
af0e2a0a | 191 | static int blktrans_ioctl(struct block_device *bdev, fmode_t mode, |
1da177e4 LT |
192 | unsigned int cmd, unsigned long arg) |
193 | { | |
af0e2a0a | 194 | struct mtd_blktrans_dev *dev = bdev->bd_disk->private_data; |
1da177e4 LT |
195 | struct mtd_blktrans_ops *tr = dev->tr; |
196 | ||
197 | switch (cmd) { | |
198 | case BLKFLSBUF: | |
199 | if (tr->flush) | |
200 | return tr->flush(dev); | |
201 | /* The core code did the work, we had nothing to do. */ | |
202 | return 0; | |
1da177e4 LT |
203 | default: |
204 | return -ENOTTY; | |
205 | } | |
206 | } | |
207 | ||
8f026f75 | 208 | static struct block_device_operations mtd_blktrans_ops = { |
1da177e4 | 209 | .owner = THIS_MODULE, |
af0e2a0a AV |
210 | .open = blktrans_open, |
211 | .release = blktrans_release, | |
212 | .locked_ioctl = blktrans_ioctl, | |
a885c8c4 | 213 | .getgeo = blktrans_getgeo, |
1da177e4 LT |
214 | }; |
215 | ||
216 | int add_mtd_blktrans_dev(struct mtd_blktrans_dev *new) | |
217 | { | |
218 | struct mtd_blktrans_ops *tr = new->tr; | |
71a928c0 | 219 | struct mtd_blktrans_dev *d; |
1da177e4 LT |
220 | int last_devnum = -1; |
221 | struct gendisk *gd; | |
222 | ||
b3561ea9 | 223 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 224 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
225 | BUG(); |
226 | } | |
227 | ||
71a928c0 | 228 | list_for_each_entry(d, &tr->devs, list) { |
1da177e4 LT |
229 | if (new->devnum == -1) { |
230 | /* Use first free number */ | |
231 | if (d->devnum != last_devnum+1) { | |
232 | /* Found a free devnum. Plug it in here */ | |
233 | new->devnum = last_devnum+1; | |
234 | list_add_tail(&new->list, &d->list); | |
235 | goto added; | |
236 | } | |
237 | } else if (d->devnum == new->devnum) { | |
238 | /* Required number taken */ | |
239 | return -EBUSY; | |
240 | } else if (d->devnum > new->devnum) { | |
241 | /* Required number was free */ | |
242 | list_add_tail(&new->list, &d->list); | |
243 | goto added; | |
97894cda | 244 | } |
1da177e4 LT |
245 | last_devnum = d->devnum; |
246 | } | |
247 | if (new->devnum == -1) | |
248 | new->devnum = last_devnum+1; | |
249 | ||
250 | if ((new->devnum << tr->part_bits) > 256) { | |
251 | return -EBUSY; | |
252 | } | |
253 | ||
1da177e4 LT |
254 | list_add_tail(&new->list, &tr->devs); |
255 | added: | |
ce37ab42 | 256 | mutex_init(&new->lock); |
1da177e4 LT |
257 | if (!tr->writesect) |
258 | new->readonly = 1; | |
259 | ||
260 | gd = alloc_disk(1 << tr->part_bits); | |
261 | if (!gd) { | |
262 | list_del(&new->list); | |
263 | return -ENOMEM; | |
264 | } | |
265 | gd->major = tr->major; | |
266 | gd->first_minor = (new->devnum) << tr->part_bits; | |
267 | gd->fops = &mtd_blktrans_ops; | |
97894cda | 268 | |
65a8de36 TP |
269 | if (tr->part_bits) |
270 | if (new->devnum < 26) | |
271 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
272 | "%s%c", tr->name, 'a' + new->devnum); | |
273 | else | |
274 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
275 | "%s%c%c", tr->name, | |
276 | 'a' - 1 + new->devnum / 26, | |
277 | 'a' + new->devnum % 26); | |
278 | else | |
279 | snprintf(gd->disk_name, sizeof(gd->disk_name), | |
280 | "%s%d", tr->name, new->devnum); | |
1da177e4 LT |
281 | |
282 | /* 2.5 has capacity in units of 512 bytes while still | |
283 | having BLOCK_SIZE_BITS set to 10. Just to keep us amused. */ | |
19187672 | 284 | set_capacity(gd, (new->size * tr->blksize) >> 9); |
1da177e4 LT |
285 | |
286 | gd->private_data = new; | |
287 | new->blkcore_priv = gd; | |
288 | gd->queue = tr->blkcore_priv->rq; | |
1f24b5a8 | 289 | gd->driverfs_dev = new->mtd->dev.parent; |
1da177e4 LT |
290 | |
291 | if (new->readonly) | |
292 | set_disk_ro(gd, 1); | |
293 | ||
294 | add_disk(gd); | |
97894cda | 295 | |
1da177e4 LT |
296 | return 0; |
297 | } | |
298 | ||
299 | int del_mtd_blktrans_dev(struct mtd_blktrans_dev *old) | |
300 | { | |
b3561ea9 | 301 | if (mutex_trylock(&mtd_table_mutex)) { |
48b19268 | 302 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
303 | BUG(); |
304 | } | |
305 | ||
306 | list_del(&old->list); | |
307 | ||
308 | del_gendisk(old->blkcore_priv); | |
309 | put_disk(old->blkcore_priv); | |
97894cda | 310 | |
1da177e4 LT |
311 | return 0; |
312 | } | |
313 | ||
314 | static void blktrans_notify_remove(struct mtd_info *mtd) | |
315 | { | |
71a928c0 CM |
316 | struct mtd_blktrans_ops *tr; |
317 | struct mtd_blktrans_dev *dev, *next; | |
1da177e4 | 318 | |
71a928c0 CM |
319 | list_for_each_entry(tr, &blktrans_majors, list) |
320 | list_for_each_entry_safe(dev, next, &tr->devs, list) | |
1da177e4 LT |
321 | if (dev->mtd == mtd) |
322 | tr->remove_dev(dev); | |
1da177e4 LT |
323 | } |
324 | ||
325 | static void blktrans_notify_add(struct mtd_info *mtd) | |
326 | { | |
71a928c0 | 327 | struct mtd_blktrans_ops *tr; |
1da177e4 LT |
328 | |
329 | if (mtd->type == MTD_ABSENT) | |
330 | return; | |
331 | ||
71a928c0 | 332 | list_for_each_entry(tr, &blktrans_majors, list) |
1da177e4 | 333 | tr->add_mtd(tr, mtd); |
1da177e4 LT |
334 | } |
335 | ||
336 | static struct mtd_notifier blktrans_notifier = { | |
337 | .add = blktrans_notify_add, | |
338 | .remove = blktrans_notify_remove, | |
339 | }; | |
97894cda | 340 | |
1da177e4 LT |
341 | int register_mtd_blktrans(struct mtd_blktrans_ops *tr) |
342 | { | |
343 | int ret, i; | |
344 | ||
97894cda | 345 | /* Register the notifier if/when the first device type is |
1da177e4 LT |
346 | registered, to prevent the link/init ordering from fucking |
347 | us over. */ | |
348 | if (!blktrans_notifier.list.next) | |
349 | register_mtd_user(&blktrans_notifier); | |
350 | ||
95b93a0c | 351 | tr->blkcore_priv = kzalloc(sizeof(*tr->blkcore_priv), GFP_KERNEL); |
1da177e4 LT |
352 | if (!tr->blkcore_priv) |
353 | return -ENOMEM; | |
354 | ||
48b19268 | 355 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
356 | |
357 | ret = register_blkdev(tr->major, tr->name); | |
358 | if (ret) { | |
359 | printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", | |
360 | tr->name, tr->major, ret); | |
361 | kfree(tr->blkcore_priv); | |
48b19268 | 362 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
363 | return ret; |
364 | } | |
365 | spin_lock_init(&tr->blkcore_priv->queue_lock); | |
1da177e4 LT |
366 | |
367 | tr->blkcore_priv->rq = blk_init_queue(mtd_blktrans_request, &tr->blkcore_priv->queue_lock); | |
368 | if (!tr->blkcore_priv->rq) { | |
369 | unregister_blkdev(tr->major, tr->name); | |
370 | kfree(tr->blkcore_priv); | |
48b19268 | 371 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
372 | return -ENOMEM; |
373 | } | |
374 | ||
375 | tr->blkcore_priv->rq->queuedata = tr; | |
19187672 | 376 | blk_queue_hardsect_size(tr->blkcore_priv->rq, tr->blksize); |
eae9acd1 DW |
377 | if (tr->discard) |
378 | blk_queue_set_discard(tr->blkcore_priv->rq, | |
379 | blktrans_discard_request); | |
380 | ||
19187672 | 381 | tr->blkshift = ffs(tr->blksize) - 1; |
1da177e4 | 382 | |
3e67fe45 CH |
383 | tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr, |
384 | "%sd", tr->name); | |
385 | if (IS_ERR(tr->blkcore_priv->thread)) { | |
2cf3a114 | 386 | int ret = PTR_ERR(tr->blkcore_priv->thread); |
1da177e4 LT |
387 | blk_cleanup_queue(tr->blkcore_priv->rq); |
388 | unregister_blkdev(tr->major, tr->name); | |
389 | kfree(tr->blkcore_priv); | |
48b19268 | 390 | mutex_unlock(&mtd_table_mutex); |
2cf3a114 | 391 | return ret; |
97894cda | 392 | } |
1da177e4 | 393 | |
1da177e4 LT |
394 | INIT_LIST_HEAD(&tr->devs); |
395 | list_add(&tr->list, &blktrans_majors); | |
396 | ||
397 | for (i=0; i<MAX_MTD_DEVICES; i++) { | |
398 | if (mtd_table[i] && mtd_table[i]->type != MTD_ABSENT) | |
399 | tr->add_mtd(tr, mtd_table[i]); | |
400 | } | |
401 | ||
48b19268 | 402 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
403 | |
404 | return 0; | |
405 | } | |
406 | ||
407 | int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr) | |
408 | { | |
71a928c0 | 409 | struct mtd_blktrans_dev *dev, *next; |
1da177e4 | 410 | |
48b19268 | 411 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
412 | |
413 | /* Clean up the kernel thread */ | |
3e67fe45 | 414 | kthread_stop(tr->blkcore_priv->thread); |
1da177e4 LT |
415 | |
416 | /* Remove it from the list of active majors */ | |
417 | list_del(&tr->list); | |
418 | ||
71a928c0 | 419 | list_for_each_entry_safe(dev, next, &tr->devs, list) |
1da177e4 | 420 | tr->remove_dev(dev); |
1da177e4 | 421 | |
1da177e4 LT |
422 | blk_cleanup_queue(tr->blkcore_priv->rq); |
423 | unregister_blkdev(tr->major, tr->name); | |
424 | ||
48b19268 | 425 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
426 | |
427 | kfree(tr->blkcore_priv); | |
428 | ||
373ebfbf | 429 | BUG_ON(!list_empty(&tr->devs)); |
1da177e4 LT |
430 | return 0; |
431 | } | |
432 | ||
433 | static void __exit mtd_blktrans_exit(void) | |
434 | { | |
435 | /* No race here -- if someone's currently in register_mtd_blktrans | |
436 | we're screwed anyway. */ | |
437 | if (blktrans_notifier.list.next) | |
438 | unregister_mtd_user(&blktrans_notifier); | |
439 | } | |
440 | ||
441 | module_exit(mtd_blktrans_exit); | |
442 | ||
443 | EXPORT_SYMBOL_GPL(register_mtd_blktrans); | |
444 | EXPORT_SYMBOL_GPL(deregister_mtd_blktrans); | |
445 | EXPORT_SYMBOL_GPL(add_mtd_blktrans_dev); | |
446 | EXPORT_SYMBOL_GPL(del_mtd_blktrans_dev); | |
447 | ||
448 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
449 | MODULE_LICENSE("GPL"); | |
450 | MODULE_DESCRIPTION("Common interface to block layer for MTD 'translation layers'"); |