Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/drivers/mmc/mmc_block.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 11276 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* |
2 | * Block driver for media (i.e., flash cards) |
3 | * |
4 | * Copyright 2002 Hewlett-Packard Company |
5 | * |
6 | * Use consistent with the GNU GPL is permitted, |
7 | * provided that this copyright notice is |
8 | * preserved in its entirety in all copies and derived works. |
9 | * |
10 | * HEWLETT-PACKARD COMPANY MAKES NO WARRANTIES, EXPRESSED OR IMPLIED, |
11 | * AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR ITS |
12 | * FITNESS FOR ANY PARTICULAR PURPOSE. |
13 | * |
14 | * Many thanks to Alessandro Rubini and Jonathan Corbet! |
15 | * |
16 | * Author: Andrew Christian |
17 | * 28 May 2002 |
18 | */ |
19 | #include <linux/moduleparam.h> |
20 | #include <linux/module.h> |
21 | #include <linux/init.h> |
22 | |
23 | #include <linux/sched.h> |
24 | #include <linux/kernel.h> |
25 | #include <linux/fs.h> |
26 | #include <linux/errno.h> |
27 | #include <linux/hdreg.h> |
28 | #include <linux/kdev_t.h> |
29 | #include <linux/blkdev.h> |
30 | #include <linux/devfs_fs_kernel.h> |
31 | |
32 | #include <linux/mmc/card.h> |
33 | #include <linux/mmc/protocol.h> |
34 | |
35 | #include <asm/system.h> |
36 | #include <asm/uaccess.h> |
37 | |
38 | #include "mmc_queue.h" |
39 | |
40 | /* |
41 | * max 8 partitions per card |
42 | */ |
43 | #define MMC_SHIFT 3 |
44 | |
45 | static int major; |
46 | |
47 | /* |
48 | * There is one mmc_blk_data per slot. |
49 | */ |
50 | struct mmc_blk_data { |
51 | spinlock_t lock; |
52 | struct gendisk *disk; |
53 | struct mmc_queue queue; |
54 | |
55 | unsigned int usage; |
56 | unsigned int block_bits; |
57 | }; |
58 | |
59 | static DECLARE_MUTEX(open_lock); |
60 | |
61 | static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk) |
62 | { |
63 | struct mmc_blk_data *md; |
64 | |
65 | down(&open_lock); |
66 | md = disk->private_data; |
67 | if (md && md->usage == 0) |
68 | md = NULL; |
69 | if (md) |
70 | md->usage++; |
71 | up(&open_lock); |
72 | |
73 | return md; |
74 | } |
75 | |
76 | static void mmc_blk_put(struct mmc_blk_data *md) |
77 | { |
78 | down(&open_lock); |
79 | md->usage--; |
80 | if (md->usage == 0) { |
81 | put_disk(md->disk); |
82 | mmc_cleanup_queue(&md->queue); |
83 | kfree(md); |
84 | } |
85 | up(&open_lock); |
86 | } |
87 | |
88 | static int mmc_blk_open(struct inode *inode, struct file *filp) |
89 | { |
90 | struct mmc_blk_data *md; |
91 | int ret = -ENXIO; |
92 | |
93 | md = mmc_blk_get(inode->i_bdev->bd_disk); |
94 | if (md) { |
95 | if (md->usage == 2) |
96 | check_disk_change(inode->i_bdev); |
97 | ret = 0; |
98 | } |
99 | |
100 | return ret; |
101 | } |
102 | |
103 | static int mmc_blk_release(struct inode *inode, struct file *filp) |
104 | { |
105 | struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data; |
106 | |
107 | mmc_blk_put(md); |
108 | return 0; |
109 | } |
110 | |
111 | static int |
112 | mmc_blk_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) |
113 | { |
114 | struct block_device *bdev = inode->i_bdev; |
115 | |
116 | if (cmd == HDIO_GETGEO) { |
117 | struct hd_geometry geo; |
118 | |
119 | memset(&geo, 0, sizeof(struct hd_geometry)); |
120 | |
121 | geo.cylinders = get_capacity(bdev->bd_disk) / (4 * 16); |
122 | geo.heads = 4; |
123 | geo.sectors = 16; |
124 | geo.start = get_start_sect(bdev); |
125 | |
126 | return copy_to_user((void __user *)arg, &geo, sizeof(geo)) |
127 | ? -EFAULT : 0; |
128 | } |
129 | |
130 | return -ENOTTY; |
131 | } |
132 | |
133 | static struct block_device_operations mmc_bdops = { |
134 | .open = mmc_blk_open, |
135 | .release = mmc_blk_release, |
136 | .ioctl = mmc_blk_ioctl, |
137 | .owner = THIS_MODULE, |
138 | }; |
139 | |
140 | struct mmc_blk_request { |
141 | struct mmc_request mrq; |
142 | struct mmc_command cmd; |
143 | struct mmc_command stop; |
144 | struct mmc_data data; |
145 | }; |
146 | |
147 | static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req) |
148 | { |
149 | struct mmc_blk_data *md = mq->data; |
150 | int stat = BLKPREP_OK; |
151 | |
152 | /* |
153 | * If we have no device, we haven't finished initialising. |
154 | */ |
155 | if (!md || !mq->card) { |
156 | printk(KERN_ERR "%s: killing request - no device/host\n", |
157 | req->rq_disk->disk_name); |
158 | stat = BLKPREP_KILL; |
159 | } |
160 | |
161 | return stat; |
162 | } |
163 | |
164 | static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) |
165 | { |
166 | struct mmc_blk_data *md = mq->data; |
167 | struct mmc_card *card = md->queue.card; |
168 | int ret; |
169 | |
170 | if (mmc_card_claim_host(card)) |
171 | goto cmd_err; |
172 | |
173 | do { |
174 | struct mmc_blk_request brq; |
175 | struct mmc_command cmd; |
176 | |
177 | memset(&brq, 0, sizeof(struct mmc_blk_request)); |
178 | brq.mrq.cmd = &brq.cmd; |
179 | brq.mrq.data = &brq.data; |
180 | |
181 | brq.cmd.arg = req->sector << 9; |
182 | brq.cmd.flags = MMC_RSP_R1; |
183 | brq.data.timeout_ns = card->csd.tacc_ns * 10; |
184 | brq.data.timeout_clks = card->csd.tacc_clks * 10; |
185 | brq.data.blksz_bits = md->block_bits; |
186 | brq.data.blocks = req->nr_sectors >> (md->block_bits - 9); |
187 | brq.stop.opcode = MMC_STOP_TRANSMISSION; |
188 | brq.stop.arg = 0; |
189 | brq.stop.flags = MMC_RSP_R1B; |
190 | |
191 | if (rq_data_dir(req) == READ) { |
192 | brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK; |
193 | brq.data.flags |= MMC_DATA_READ; |
194 | } else { |
195 | brq.cmd.opcode = MMC_WRITE_BLOCK; |
196 | brq.cmd.flags = MMC_RSP_R1B; |
197 | brq.data.flags |= MMC_DATA_WRITE; |
198 | brq.data.blocks = 1; |
199 | } |
200 | brq.mrq.stop = brq.data.blocks > 1 ? &brq.stop : NULL; |
201 | |
202 | brq.data.sg = mq->sg; |
203 | brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg); |
204 | |
205 | mmc_wait_for_req(card->host, &brq.mrq); |
206 | if (brq.cmd.error) { |
207 | printk(KERN_ERR "%s: error %d sending read/write command\n", |
208 | req->rq_disk->disk_name, brq.cmd.error); |
209 | goto cmd_err; |
210 | } |
211 | |
212 | if (brq.data.error) { |
213 | printk(KERN_ERR "%s: error %d transferring data\n", |
214 | req->rq_disk->disk_name, brq.data.error); |
215 | goto cmd_err; |
216 | } |
217 | |
218 | if (brq.stop.error) { |
219 | printk(KERN_ERR "%s: error %d sending stop command\n", |
220 | req->rq_disk->disk_name, brq.stop.error); |
221 | goto cmd_err; |
222 | } |
223 | |
224 | do { |
225 | int err; |
226 | |
227 | cmd.opcode = MMC_SEND_STATUS; |
228 | cmd.arg = card->rca << 16; |
229 | cmd.flags = MMC_RSP_R1; |
230 | err = mmc_wait_for_cmd(card->host, &cmd, 5); |
231 | if (err) { |
232 | printk(KERN_ERR "%s: error %d requesting status\n", |
233 | req->rq_disk->disk_name, err); |
234 | goto cmd_err; |
235 | } |
236 | } while (!(cmd.resp[0] & R1_READY_FOR_DATA)); |
237 | |
238 | #if 0 |
239 | if (cmd.resp[0] & ~0x00000900) |
240 | printk(KERN_ERR "%s: status = %08x\n", |
241 | req->rq_disk->disk_name, cmd.resp[0]); |
242 | if (mmc_decode_status(cmd.resp)) |
243 | goto cmd_err; |
244 | #endif |
245 | |
246 | /* |
247 | * A block was successfully transferred. |
248 | */ |
249 | spin_lock_irq(&md->lock); |
250 | ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered); |
251 | if (!ret) { |
252 | /* |
253 | * The whole request completed successfully. |
254 | */ |
255 | add_disk_randomness(req->rq_disk); |
256 | blkdev_dequeue_request(req); |
257 | end_that_request_last(req); |
258 | } |
259 | spin_unlock_irq(&md->lock); |
260 | } while (ret); |
261 | |
262 | mmc_card_release_host(card); |
263 | |
264 | return 1; |
265 | |
266 | cmd_err: |
267 | mmc_card_release_host(card); |
268 | |
269 | /* |
270 | * This is a little draconian, but until we get proper |
271 | * error handling sorted out here, its the best we can |
272 | * do - especially as some hosts have no idea how much |
273 | * data was transferred before the error occurred. |
274 | */ |
275 | spin_lock_irq(&md->lock); |
276 | do { |
277 | ret = end_that_request_chunk(req, 0, |
278 | req->current_nr_sectors << 9); |
279 | } while (ret); |
280 | |
281 | add_disk_randomness(req->rq_disk); |
282 | blkdev_dequeue_request(req); |
283 | end_that_request_last(req); |
284 | spin_unlock_irq(&md->lock); |
285 | |
286 | return 0; |
287 | } |
288 | |
289 | #define MMC_NUM_MINORS (256 >> MMC_SHIFT) |
290 | |
291 | static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))]; |
292 | |
293 | static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card) |
294 | { |
295 | struct mmc_blk_data *md; |
296 | int devidx, ret; |
297 | |
298 | devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS); |
299 | if (devidx >= MMC_NUM_MINORS) |
300 | return ERR_PTR(-ENOSPC); |
301 | __set_bit(devidx, dev_use); |
302 | |
303 | md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL); |
304 | if (md) { |
305 | memset(md, 0, sizeof(struct mmc_blk_data)); |
306 | |
307 | md->disk = alloc_disk(1 << MMC_SHIFT); |
308 | if (md->disk == NULL) { |
309 | kfree(md); |
310 | md = ERR_PTR(-ENOMEM); |
311 | goto out; |
312 | } |
313 | |
314 | spin_lock_init(&md->lock); |
315 | md->usage = 1; |
316 | |
317 | ret = mmc_init_queue(&md->queue, card, &md->lock); |
318 | if (ret) { |
319 | put_disk(md->disk); |
320 | kfree(md); |
321 | md = ERR_PTR(ret); |
322 | goto out; |
323 | } |
324 | md->queue.prep_fn = mmc_blk_prep_rq; |
325 | md->queue.issue_fn = mmc_blk_issue_rq; |
326 | md->queue.data = md; |
327 | |
328 | md->disk->major = major; |
329 | md->disk->first_minor = devidx << MMC_SHIFT; |
330 | md->disk->fops = &mmc_bdops; |
331 | md->disk->private_data = md; |
332 | md->disk->queue = md->queue.queue; |
333 | md->disk->driverfs_dev = &card->dev; |
334 | |
335 | /* |
336 | * As discussed on lkml, GENHD_FL_REMOVABLE should: |
337 | * |
338 | * - be set for removable media with permanent block devices |
339 | * - be unset for removable block devices with permanent media |
340 | * |
341 | * Since MMC block devices clearly fall under the second |
342 | * case, we do not set GENHD_FL_REMOVABLE. Userspace |
343 | * should use the block device creation/destruction hotplug |
344 | * messages to tell when the card is present. |
345 | */ |
346 | |
347 | sprintf(md->disk->disk_name, "mmcblk%d", devidx); |
348 | sprintf(md->disk->devfs_name, "mmc/blk%d", devidx); |
349 | |
350 | md->block_bits = card->csd.read_blkbits; |
351 | |
352 | blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits); |
353 | set_capacity(md->disk, card->csd.capacity); |
354 | } |
355 | out: |
356 | return md; |
357 | } |
358 | |
359 | static int |
360 | mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card) |
361 | { |
362 | struct mmc_command cmd; |
363 | int err; |
364 | |
365 | mmc_card_claim_host(card); |
366 | cmd.opcode = MMC_SET_BLOCKLEN; |
367 | cmd.arg = 1 << card->csd.read_blkbits; |
368 | cmd.flags = MMC_RSP_R1; |
369 | err = mmc_wait_for_cmd(card->host, &cmd, 5); |
370 | mmc_card_release_host(card); |
371 | |
372 | if (err) { |
373 | printk(KERN_ERR "%s: unable to set block size to %d: %d\n", |
374 | md->disk->disk_name, cmd.arg, err); |
375 | return -EINVAL; |
376 | } |
377 | |
378 | return 0; |
379 | } |
380 | |
381 | static int mmc_blk_probe(struct mmc_card *card) |
382 | { |
383 | struct mmc_blk_data *md; |
384 | int err; |
385 | |
386 | /* |
387 | * Check that the card supports the command class(es) we need. |
388 | */ |
389 | if (!(card->csd.cmdclass & CCC_BLOCK_READ)) |
390 | return -ENODEV; |
391 | |
392 | if (card->csd.read_blkbits < 9) { |
393 | printk(KERN_WARNING "%s: read blocksize too small (%u)\n", |
394 | mmc_card_id(card), 1 << card->csd.read_blkbits); |
395 | return -ENODEV; |
396 | } |
397 | |
398 | md = mmc_blk_alloc(card); |
399 | if (IS_ERR(md)) |
400 | return PTR_ERR(md); |
401 | |
402 | err = mmc_blk_set_blksize(md, card); |
403 | if (err) |
404 | goto out; |
405 | |
406 | printk(KERN_INFO "%s: %s %s %dKiB\n", |
407 | md->disk->disk_name, mmc_card_id(card), mmc_card_name(card), |
408 | (card->csd.capacity << card->csd.read_blkbits) / 1024); |
409 | |
410 | mmc_set_drvdata(card, md); |
411 | add_disk(md->disk); |
412 | return 0; |
413 | |
414 | out: |
415 | mmc_blk_put(md); |
416 | |
417 | return err; |
418 | } |
419 | |
420 | static void mmc_blk_remove(struct mmc_card *card) |
421 | { |
422 | struct mmc_blk_data *md = mmc_get_drvdata(card); |
423 | |
424 | if (md) { |
425 | int devidx; |
426 | |
427 | del_gendisk(md->disk); |
428 | |
429 | /* |
430 | * I think this is needed. |
431 | */ |
432 | md->disk->queue = NULL; |
433 | |
434 | devidx = md->disk->first_minor >> MMC_SHIFT; |
435 | __clear_bit(devidx, dev_use); |
436 | |
437 | mmc_blk_put(md); |
438 | } |
439 | mmc_set_drvdata(card, NULL); |
440 | } |
441 | |
442 | #ifdef CONFIG_PM |
443 | static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state) |
444 | { |
445 | struct mmc_blk_data *md = mmc_get_drvdata(card); |
446 | |
447 | if (md) { |
448 | mmc_queue_suspend(&md->queue); |
449 | } |
450 | return 0; |
451 | } |
452 | |
453 | static int mmc_blk_resume(struct mmc_card *card) |
454 | { |
455 | struct mmc_blk_data *md = mmc_get_drvdata(card); |
456 | |
457 | if (md) { |
458 | mmc_blk_set_blksize(md, card); |
459 | mmc_queue_resume(&md->queue); |
460 | } |
461 | return 0; |
462 | } |
463 | #else |
464 | #define mmc_blk_suspend NULL |
465 | #define mmc_blk_resume NULL |
466 | #endif |
467 | |
468 | static struct mmc_driver mmc_driver = { |
469 | .drv = { |
470 | .name = "mmcblk", |
471 | }, |
472 | .probe = mmc_blk_probe, |
473 | .remove = mmc_blk_remove, |
474 | .suspend = mmc_blk_suspend, |
475 | .resume = mmc_blk_resume, |
476 | }; |
477 | |
478 | static int __init mmc_blk_init(void) |
479 | { |
480 | int res = -ENOMEM; |
481 | |
482 | res = register_blkdev(major, "mmc"); |
483 | if (res < 0) { |
484 | printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n", |
485 | major, res); |
486 | goto out; |
487 | } |
488 | if (major == 0) |
489 | major = res; |
490 | |
491 | devfs_mk_dir("mmc"); |
492 | return mmc_register_driver(&mmc_driver); |
493 | |
494 | out: |
495 | return res; |
496 | } |
497 | |
498 | static void __exit mmc_blk_exit(void) |
499 | { |
500 | mmc_unregister_driver(&mmc_driver); |
501 | devfs_remove("mmc"); |
502 | unregister_blkdev(major, "mmc"); |
503 | } |
504 | |
505 | module_init(mmc_blk_init); |
506 | module_exit(mmc_blk_exit); |
507 | |
508 | MODULE_LICENSE("GPL"); |
509 | MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver"); |
510 | |
511 | module_param(major, int, 0444); |
512 | MODULE_PARM_DESC(major, "specify the major device number for MMC block driver"); |