1 /*
2 * linux/drivers/mmc/card/queue.c
3 *
4 * Copyright (C) 2003 Russell King, All Rights Reserved.
5 * Copyright 2006-2007 Pierre Ossman
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 */
12 #include <linux/slab.h>
13 #include <linux/module.h>
14 #include <linux/blkdev.h>
15 #include <linux/freezer.h>
16 #include <linux/kthread.h>
17 #include <linux/scatterlist.h>
18 #include <linux/dma-mapping.h>
19
20 #include <linux/mmc/card.h>
21 #include <linux/mmc/host.h>
22 #include "queue.h"
23
24 #define MMC_QUEUE_BOUNCESZ 65536
25
26 /*
27 * Prepare a MMC request. This just filters out odd stuff.
28 */
mmc_prep_request(struct request_queue * q,struct request * req)29 static int mmc_prep_request(struct request_queue *q, struct request *req)
30 {
31 struct mmc_queue *mq = q->queuedata;
32
33 /*
34 * We only like normal block requests and discards.
35 */
36 if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) {
37 blk_dump_rq_flags(req, "MMC bad request");
38 return BLKPREP_KILL;
39 }
40
41 if (mq && (mmc_card_removed(mq->card) || mmc_access_rpmb(mq)))
42 return BLKPREP_KILL;
43
44 req->cmd_flags |= REQ_DONTPREP;
45
46 return BLKPREP_OK;
47 }
48
mmc_queue_thread(void * d)49 static int mmc_queue_thread(void *d)
50 {
51 struct mmc_queue *mq = d;
52 struct request_queue *q = mq->queue;
53
54 current->flags |= PF_MEMALLOC;
55
56 down(&mq->thread_sem);
57 do {
58 struct request *req = NULL;
59 struct mmc_queue_req *tmp;
60 unsigned int cmd_flags = 0;
61
62 spin_lock_irq(q->queue_lock);
63 set_current_state(TASK_INTERRUPTIBLE);
64 req = blk_fetch_request(q);
65 mq->mqrq_cur->req = req;
66 spin_unlock_irq(q->queue_lock);
67
68 if (req || mq->mqrq_prev->req) {
69 set_current_state(TASK_RUNNING);
70 cmd_flags = req ? req->cmd_flags : 0;
71 mq->issue_fn(mq, req);
72 if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
73 mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
74 continue; /* fetch again */
75 }
76
77 /*
78 * Current request becomes previous request
79 * and vice versa.
80 * In case of special requests, current request
81 * has been finished. Do not assign it to previous
82 * request.
83 */
84 if (cmd_flags & MMC_REQ_SPECIAL_MASK)
85 mq->mqrq_cur->req = NULL;
86
87 mq->mqrq_prev->brq.mrq.data = NULL;
88 mq->mqrq_prev->req = NULL;
89 tmp = mq->mqrq_prev;
90 mq->mqrq_prev = mq->mqrq_cur;
91 mq->mqrq_cur = tmp;
92 } else {
93 if (kthread_should_stop()) {
94 set_current_state(TASK_RUNNING);
95 break;
96 }
97 up(&mq->thread_sem);
98 schedule();
99 down(&mq->thread_sem);
100 }
101 } while (1);
102 up(&mq->thread_sem);
103
104 return 0;
105 }
106
107 /*
108 * Generic MMC request handler. This is called for any queue on a
109 * particular host. When the host is not busy, we look for a request
110 * on any queue on this host, and attempt to issue it. This may
111 * not be the queue we were asked to process.
112 */
mmc_request_fn(struct request_queue * q)113 static void mmc_request_fn(struct request_queue *q)
114 {
115 struct mmc_queue *mq = q->queuedata;
116 struct request *req;
117 unsigned long flags;
118 struct mmc_context_info *cntx;
119
120 if (!mq) {
121 while ((req = blk_fetch_request(q)) != NULL) {
122 req->cmd_flags |= REQ_QUIET;
123 __blk_end_request_all(req, -EIO);
124 }
125 return;
126 }
127
128 cntx = &mq->card->host->context_info;
129 if (!mq->mqrq_cur->req && mq->mqrq_prev->req) {
130 /*
131 * New MMC request arrived when MMC thread may be
132 * blocked on the previous request to be complete
133 * with no current request fetched
134 */
135 spin_lock_irqsave(&cntx->lock, flags);
136 if (cntx->is_waiting_last_req) {
137 cntx->is_new_req = true;
138 wake_up_interruptible(&cntx->wait);
139 }
140 spin_unlock_irqrestore(&cntx->lock, flags);
141 } else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
142 wake_up_process(mq->thread);
143 }
144
mmc_alloc_sg(int sg_len,int * err)145 static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
146 {
147 struct scatterlist *sg;
148
149 sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
150 if (!sg)
151 *err = -ENOMEM;
152 else {
153 *err = 0;
154 sg_init_table(sg, sg_len);
155 }
156
157 return sg;
158 }
159
mmc_queue_setup_discard(struct request_queue * q,struct mmc_card * card)160 static void mmc_queue_setup_discard(struct request_queue *q,
161 struct mmc_card *card)
162 {
163 unsigned max_discard;
164
165 max_discard = mmc_calc_max_discard(card);
166 if (!max_discard)
167 return;
168
169 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
170 q->limits.max_discard_sectors = max_discard;
171 if (card->erased_byte == 0 && !mmc_can_discard(card))
172 q->limits.discard_zeroes_data = 1;
173 q->limits.discard_granularity = card->pref_erase << 9;
174 /* granularity must not be greater than max. discard */
175 if (card->pref_erase > max_discard)
176 q->limits.discard_granularity = 0;
177 if (mmc_can_secure_erase_trim(card))
178 queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);
179 }
180
181 /**
182 * mmc_init_queue - initialise a queue structure.
183 * @mq: mmc queue
184 * @card: mmc card to attach this queue
185 * @lock: queue lock
186 * @subname: partition subname
187 *
188 * Initialise a MMC card request queue.
189 */
mmc_init_queue(struct mmc_queue * mq,struct mmc_card * card,spinlock_t * lock,const char * subname)190 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
191 spinlock_t *lock, const char *subname)
192 {
193 struct mmc_host *host = card->host;
194 u64 limit = BLK_BOUNCE_HIGH;
195 int ret;
196 struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
197 struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
198
199 if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
200 limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
201
202 mq->card = card;
203 mq->queue = blk_init_queue(mmc_request_fn, lock);
204 if (!mq->queue)
205 return -ENOMEM;
206
207 mq->mqrq_cur = mqrq_cur;
208 mq->mqrq_prev = mqrq_prev;
209 mq->queue->queuedata = mq;
210
211 blk_queue_prep_rq(mq->queue, mmc_prep_request);
212 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
213 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue);
214 if (mmc_can_erase(card))
215 mmc_queue_setup_discard(mq->queue, card);
216
217 #ifdef CONFIG_MMC_BLOCK_BOUNCE
218 if (host->max_segs == 1) {
219 unsigned int bouncesz;
220
221 bouncesz = MMC_QUEUE_BOUNCESZ;
222
223 if (bouncesz > host->max_req_size)
224 bouncesz = host->max_req_size;
225 if (bouncesz > host->max_seg_size)
226 bouncesz = host->max_seg_size;
227 if (bouncesz > (host->max_blk_count * 512))
228 bouncesz = host->max_blk_count * 512;
229
230 if (bouncesz > 512) {
231 mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
232 if (!mqrq_cur->bounce_buf) {
233 pr_warn("%s: unable to allocate bounce cur buffer\n",
234 mmc_card_name(card));
235 } else {
236 mqrq_prev->bounce_buf =
237 kmalloc(bouncesz, GFP_KERNEL);
238 if (!mqrq_prev->bounce_buf) {
239 pr_warn("%s: unable to allocate bounce prev buffer\n",
240 mmc_card_name(card));
241 kfree(mqrq_cur->bounce_buf);
242 mqrq_cur->bounce_buf = NULL;
243 }
244 }
245 }
246
247 if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {
248 blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
249 blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
250 blk_queue_max_segments(mq->queue, bouncesz / 512);
251 blk_queue_max_segment_size(mq->queue, bouncesz);
252
253 mqrq_cur->sg = mmc_alloc_sg(1, &ret);
254 if (ret)
255 goto cleanup_queue;
256
257 mqrq_cur->bounce_sg =
258 mmc_alloc_sg(bouncesz / 512, &ret);
259 if (ret)
260 goto cleanup_queue;
261
262 mqrq_prev->sg = mmc_alloc_sg(1, &ret);
263 if (ret)
264 goto cleanup_queue;
265
266 mqrq_prev->bounce_sg =
267 mmc_alloc_sg(bouncesz / 512, &ret);
268 if (ret)
269 goto cleanup_queue;
270 }
271 }
272 #endif
273
274 if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {
275 blk_queue_bounce_limit(mq->queue, limit);
276 blk_queue_max_hw_sectors(mq->queue,
277 min(host->max_blk_count, host->max_req_size / 512));
278 blk_queue_max_segments(mq->queue, host->max_segs);
279 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
280
281 mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);
282 if (ret)
283 goto cleanup_queue;
284
285
286 mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
287 if (ret)
288 goto cleanup_queue;
289 }
290
291 sema_init(&mq->thread_sem, 1);
292
293 mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
294 host->index, subname ? subname : "");
295
296 if (IS_ERR(mq->thread)) {
297 ret = PTR_ERR(mq->thread);
298 goto free_bounce_sg;
299 }
300
301 return 0;
302 free_bounce_sg:
303 kfree(mqrq_cur->bounce_sg);
304 mqrq_cur->bounce_sg = NULL;
305 kfree(mqrq_prev->bounce_sg);
306 mqrq_prev->bounce_sg = NULL;
307
308 cleanup_queue:
309 kfree(mqrq_cur->sg);
310 mqrq_cur->sg = NULL;
311 kfree(mqrq_cur->bounce_buf);
312 mqrq_cur->bounce_buf = NULL;
313
314 kfree(mqrq_prev->sg);
315 mqrq_prev->sg = NULL;
316 kfree(mqrq_prev->bounce_buf);
317 mqrq_prev->bounce_buf = NULL;
318
319 blk_cleanup_queue(mq->queue);
320 return ret;
321 }
322
mmc_cleanup_queue(struct mmc_queue * mq)323 void mmc_cleanup_queue(struct mmc_queue *mq)
324 {
325 struct request_queue *q = mq->queue;
326 unsigned long flags;
327 struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
328 struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
329
330 /* Make sure the queue isn't suspended, as that will deadlock */
331 mmc_queue_resume(mq);
332
333 /* Then terminate our worker thread */
334 kthread_stop(mq->thread);
335
336 /* Empty the queue */
337 spin_lock_irqsave(q->queue_lock, flags);
338 q->queuedata = NULL;
339 blk_start_queue(q);
340 spin_unlock_irqrestore(q->queue_lock, flags);
341
342 kfree(mqrq_cur->bounce_sg);
343 mqrq_cur->bounce_sg = NULL;
344
345 kfree(mqrq_cur->sg);
346 mqrq_cur->sg = NULL;
347
348 kfree(mqrq_cur->bounce_buf);
349 mqrq_cur->bounce_buf = NULL;
350
351 kfree(mqrq_prev->bounce_sg);
352 mqrq_prev->bounce_sg = NULL;
353
354 kfree(mqrq_prev->sg);
355 mqrq_prev->sg = NULL;
356
357 kfree(mqrq_prev->bounce_buf);
358 mqrq_prev->bounce_buf = NULL;
359
360 mq->card = NULL;
361 }
362 EXPORT_SYMBOL(mmc_cleanup_queue);
363
mmc_packed_init(struct mmc_queue * mq,struct mmc_card * card)364 int mmc_packed_init(struct mmc_queue *mq, struct mmc_card *card)
365 {
366 struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
367 struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
368 int ret = 0;
369
370
371 mqrq_cur->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
372 if (!mqrq_cur->packed) {
373 pr_warn("%s: unable to allocate packed cmd for mqrq_cur\n",
374 mmc_card_name(card));
375 ret = -ENOMEM;
376 goto out;
377 }
378
379 mqrq_prev->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
380 if (!mqrq_prev->packed) {
381 pr_warn("%s: unable to allocate packed cmd for mqrq_prev\n",
382 mmc_card_name(card));
383 kfree(mqrq_cur->packed);
384 mqrq_cur->packed = NULL;
385 ret = -ENOMEM;
386 goto out;
387 }
388
389 INIT_LIST_HEAD(&mqrq_cur->packed->list);
390 INIT_LIST_HEAD(&mqrq_prev->packed->list);
391
392 out:
393 return ret;
394 }
395
mmc_packed_clean(struct mmc_queue * mq)396 void mmc_packed_clean(struct mmc_queue *mq)
397 {
398 struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
399 struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
400
401 kfree(mqrq_cur->packed);
402 mqrq_cur->packed = NULL;
403 kfree(mqrq_prev->packed);
404 mqrq_prev->packed = NULL;
405 }
406
407 /**
408 * mmc_queue_suspend - suspend a MMC request queue
409 * @mq: MMC queue to suspend
410 *
411 * Stop the block request queue, and wait for our thread to
412 * complete any outstanding requests. This ensures that we
413 * won't suspend while a request is being processed.
414 */
mmc_queue_suspend(struct mmc_queue * mq)415 void mmc_queue_suspend(struct mmc_queue *mq)
416 {
417 struct request_queue *q = mq->queue;
418 unsigned long flags;
419
420 if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
421 mq->flags |= MMC_QUEUE_SUSPENDED;
422
423 spin_lock_irqsave(q->queue_lock, flags);
424 blk_stop_queue(q);
425 spin_unlock_irqrestore(q->queue_lock, flags);
426
427 down(&mq->thread_sem);
428 }
429 }
430
431 /**
432 * mmc_queue_resume - resume a previously suspended MMC request queue
433 * @mq: MMC queue to resume
434 */
mmc_queue_resume(struct mmc_queue * mq)435 void mmc_queue_resume(struct mmc_queue *mq)
436 {
437 struct request_queue *q = mq->queue;
438 unsigned long flags;
439
440 if (mq->flags & MMC_QUEUE_SUSPENDED) {
441 mq->flags &= ~MMC_QUEUE_SUSPENDED;
442
443 up(&mq->thread_sem);
444
445 spin_lock_irqsave(q->queue_lock, flags);
446 blk_start_queue(q);
447 spin_unlock_irqrestore(q->queue_lock, flags);
448 }
449 }
450
mmc_queue_packed_map_sg(struct mmc_queue * mq,struct mmc_packed * packed,struct scatterlist * sg,enum mmc_packed_type cmd_type)451 static unsigned int mmc_queue_packed_map_sg(struct mmc_queue *mq,
452 struct mmc_packed *packed,
453 struct scatterlist *sg,
454 enum mmc_packed_type cmd_type)
455 {
456 struct scatterlist *__sg = sg;
457 unsigned int sg_len = 0;
458 struct request *req;
459
460 if (mmc_packed_wr(cmd_type)) {
461 unsigned int hdr_sz = mmc_large_sector(mq->card) ? 4096 : 512;
462 unsigned int max_seg_sz = queue_max_segment_size(mq->queue);
463 unsigned int len, remain, offset = 0;
464 u8 *buf = (u8 *)packed->cmd_hdr;
465
466 remain = hdr_sz;
467 do {
468 len = min(remain, max_seg_sz);
469 sg_set_buf(__sg, buf + offset, len);
470 offset += len;
471 remain -= len;
472 (__sg++)->page_link &= ~0x02;
473 sg_len++;
474 } while (remain);
475 }
476
477 list_for_each_entry(req, &packed->list, queuelist) {
478 sg_len += blk_rq_map_sg(mq->queue, req, __sg);
479 __sg = sg + (sg_len - 1);
480 (__sg++)->page_link &= ~0x02;
481 }
482 sg_mark_end(sg + (sg_len - 1));
483 return sg_len;
484 }
485
486 /*
487 * Prepare the sg list(s) to be handed of to the host driver
488 */
mmc_queue_map_sg(struct mmc_queue * mq,struct mmc_queue_req * mqrq)489 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
490 {
491 unsigned int sg_len;
492 size_t buflen;
493 struct scatterlist *sg;
494 enum mmc_packed_type cmd_type;
495 int i;
496
497 cmd_type = mqrq->cmd_type;
498
499 if (!mqrq->bounce_buf) {
500 if (mmc_packed_cmd(cmd_type))
501 return mmc_queue_packed_map_sg(mq, mqrq->packed,
502 mqrq->sg, cmd_type);
503 else
504 return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
505 }
506
507 BUG_ON(!mqrq->bounce_sg);
508
509 if (mmc_packed_cmd(cmd_type))
510 sg_len = mmc_queue_packed_map_sg(mq, mqrq->packed,
511 mqrq->bounce_sg, cmd_type);
512 else
513 sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
514
515 mqrq->bounce_sg_len = sg_len;
516
517 buflen = 0;
518 for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
519 buflen += sg->length;
520
521 sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen);
522
523 return 1;
524 }
525
526 /*
527 * If writing, bounce the data to the buffer before the request
528 * is sent to the host driver
529 */
mmc_queue_bounce_pre(struct mmc_queue_req * mqrq)530 void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq)
531 {
532 if (!mqrq->bounce_buf)
533 return;
534
535 if (rq_data_dir(mqrq->req) != WRITE)
536 return;
537
538 sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
539 mqrq->bounce_buf, mqrq->sg[0].length);
540 }
541
542 /*
543 * If reading, bounce the data from the buffer after the request
544 * has been handled by the host driver
545 */
mmc_queue_bounce_post(struct mmc_queue_req * mqrq)546 void mmc_queue_bounce_post(struct mmc_queue_req *mqrq)
547 {
548 if (!mqrq->bounce_buf)
549 return;
550
551 if (rq_data_dir(mqrq->req) != READ)
552 return;
553
554 sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
555 mqrq->bounce_buf, mqrq->sg[0].length);
556 }
557