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
19 #include <linux/mmc/card.h>
20 #include <linux/mmc/host.h>
21 #include <linux/sched/rt.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))
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 struct sched_param scheduler_params = {0};
55 scheduler_params.sched_priority = 1;
56
57 sched_setscheduler(current, SCHED_FIFO, &scheduler_params);
58
59 current->flags |= PF_MEMALLOC;
60
61 down(&mq->thread_sem);
62 do {
63 struct request *req = NULL;
64 struct mmc_queue_req *tmp;
65 unsigned int cmd_flags = 0;
66
67 spin_lock_irq(q->queue_lock);
68 set_current_state(TASK_INTERRUPTIBLE);
69 req = blk_fetch_request(q);
70 mq->mqrq_cur->req = req;
71 spin_unlock_irq(q->queue_lock);
72
73 if (req || mq->mqrq_prev->req) {
74 set_current_state(TASK_RUNNING);
75 cmd_flags = req ? req->cmd_flags : 0;
76 mq->issue_fn(mq, req);
77 if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
78 mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
79 continue; /* fetch again */
80 }
81
82 /*
83 * Current request becomes previous request
84 * and vice versa.
85 * In case of special requests, current request
86 * has been finished. Do not assign it to previous
87 * request.
88 */
89 if (cmd_flags & MMC_REQ_SPECIAL_MASK)
90 mq->mqrq_cur->req = NULL;
91
92 mq->mqrq_prev->brq.mrq.data = NULL;
93 mq->mqrq_prev->req = NULL;
94 tmp = mq->mqrq_prev;
95 mq->mqrq_prev = mq->mqrq_cur;
96 mq->mqrq_cur = tmp;
97 } else {
98 if (kthread_should_stop()) {
99 set_current_state(TASK_RUNNING);
100 break;
101 }
102 up(&mq->thread_sem);
103 schedule();
104 down(&mq->thread_sem);
105 }
106 } while (1);
107 up(&mq->thread_sem);
108
109 return 0;
110 }
111
112 /*
113 * Generic MMC request handler. This is called for any queue on a
114 * particular host. When the host is not busy, we look for a request
115 * on any queue on this host, and attempt to issue it. This may
116 * not be the queue we were asked to process.
117 */
mmc_request_fn(struct request_queue * q)118 static void mmc_request_fn(struct request_queue *q)
119 {
120 struct mmc_queue *mq = q->queuedata;
121 struct request *req;
122 unsigned long flags;
123 struct mmc_context_info *cntx;
124
125 if (!mq) {
126 while ((req = blk_fetch_request(q)) != NULL) {
127 req->cmd_flags |= REQ_QUIET;
128 __blk_end_request_all(req, -EIO);
129 }
130 return;
131 }
132
133 cntx = &mq->card->host->context_info;
134 if (!mq->mqrq_cur->req && mq->mqrq_prev->req) {
135 /*
136 * New MMC request arrived when MMC thread may be
137 * blocked on the previous request to be complete
138 * with no current request fetched
139 */
140 spin_lock_irqsave(&cntx->lock, flags);
141 if (cntx->is_waiting_last_req) {
142 cntx->is_new_req = true;
143 wake_up_interruptible(&cntx->wait);
144 }
145 spin_unlock_irqrestore(&cntx->lock, flags);
146 } else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
147 wake_up_process(mq->thread);
148 }
149
mmc_alloc_sg(int sg_len,int * err)150 static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
151 {
152 struct scatterlist *sg;
153
154 sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
155 if (!sg)
156 *err = -ENOMEM;
157 else {
158 *err = 0;
159 sg_init_table(sg, sg_len);
160 }
161
162 return sg;
163 }
164
mmc_queue_setup_discard(struct request_queue * q,struct mmc_card * card)165 static void mmc_queue_setup_discard(struct request_queue *q,
166 struct mmc_card *card)
167 {
168 unsigned max_discard;
169
170 max_discard = mmc_calc_max_discard(card);
171 if (!max_discard)
172 return;
173
174 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
175 q->limits.max_discard_sectors = max_discard;
176 if (card->erased_byte == 0 && !mmc_can_discard(card))
177 q->limits.discard_zeroes_data = 1;
178 q->limits.discard_granularity = card->pref_erase << 9;
179 /* granularity must not be greater than max. discard */
180 if (card->pref_erase > max_discard)
181 q->limits.discard_granularity = 0;
182 if (mmc_can_secure_erase_trim(card) || mmc_can_sanitize(card))
183 queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);
184 }
185
186 /**
187 * mmc_init_queue - initialise a queue structure.
188 * @mq: mmc queue
189 * @card: mmc card to attach this queue
190 * @lock: queue lock
191 * @subname: partition subname
192 *
193 * Initialise a MMC card request queue.
194 */
mmc_init_queue(struct mmc_queue * mq,struct mmc_card * card,spinlock_t * lock,const char * subname)195 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
196 spinlock_t *lock, const char *subname)
197 {
198 struct mmc_host *host = card->host;
199 u64 limit = BLK_BOUNCE_HIGH;
200 int ret;
201 struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
202 struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
203
204 if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
205 limit = *mmc_dev(host)->dma_mask;
206
207 mq->card = card;
208 mq->queue = blk_init_queue(mmc_request_fn, lock);
209 if (!mq->queue)
210 return -ENOMEM;
211
212 mq->mqrq_cur = mqrq_cur;
213 mq->mqrq_prev = mqrq_prev;
214 mq->queue->queuedata = mq;
215
216 blk_queue_prep_rq(mq->queue, mmc_prep_request);
217 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
218 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue);
219 if (mmc_can_erase(card))
220 mmc_queue_setup_discard(mq->queue, card);
221
222 #ifdef CONFIG_MMC_BLOCK_BOUNCE
223 if (host->max_segs == 1) {
224 unsigned int bouncesz;
225
226 bouncesz = MMC_QUEUE_BOUNCESZ;
227
228 if (bouncesz > host->max_req_size)
229 bouncesz = host->max_req_size;
230 if (bouncesz > host->max_seg_size)
231 bouncesz = host->max_seg_size;
232 if (bouncesz > (host->max_blk_count * 512))
233 bouncesz = host->max_blk_count * 512;
234
235 if (bouncesz > 512) {
236 mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
237 if (!mqrq_cur->bounce_buf) {
238 pr_warning("%s: unable to "
239 "allocate bounce cur buffer\n",
240 mmc_card_name(card));
241 }
242 mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
243 if (!mqrq_prev->bounce_buf) {
244 pr_warning("%s: unable to "
245 "allocate bounce prev buffer\n",
246 mmc_card_name(card));
247 kfree(mqrq_cur->bounce_buf);
248 mqrq_cur->bounce_buf = NULL;
249 }
250 }
251
252 if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {
253 blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
254 blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
255 blk_queue_max_segments(mq->queue, bouncesz / 512);
256 blk_queue_max_segment_size(mq->queue, bouncesz);
257
258 mqrq_cur->sg = mmc_alloc_sg(1, &ret);
259 if (ret)
260 goto cleanup_queue;
261
262 mqrq_cur->bounce_sg =
263 mmc_alloc_sg(bouncesz / 512, &ret);
264 if (ret)
265 goto cleanup_queue;
266
267 mqrq_prev->sg = mmc_alloc_sg(1, &ret);
268 if (ret)
269 goto cleanup_queue;
270
271 mqrq_prev->bounce_sg =
272 mmc_alloc_sg(bouncesz / 512, &ret);
273 if (ret)
274 goto cleanup_queue;
275 }
276 }
277 #endif
278
279 if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {
280 blk_queue_bounce_limit(mq->queue, limit);
281 blk_queue_max_hw_sectors(mq->queue,
282 min(host->max_blk_count, host->max_req_size / 512));
283 blk_queue_max_segments(mq->queue, host->max_segs);
284 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
285
286 mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);
287 if (ret)
288 goto cleanup_queue;
289
290
291 mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
292 if (ret)
293 goto cleanup_queue;
294 }
295
296 sema_init(&mq->thread_sem, 1);
297
298 mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
299 host->index, subname ? subname : "");
300
301 if (IS_ERR(mq->thread)) {
302 ret = PTR_ERR(mq->thread);
303 goto free_bounce_sg;
304 }
305
306 return 0;
307 free_bounce_sg:
308 kfree(mqrq_cur->bounce_sg);
309 mqrq_cur->bounce_sg = NULL;
310 kfree(mqrq_prev->bounce_sg);
311 mqrq_prev->bounce_sg = NULL;
312
313 cleanup_queue:
314 kfree(mqrq_cur->sg);
315 mqrq_cur->sg = NULL;
316 kfree(mqrq_cur->bounce_buf);
317 mqrq_cur->bounce_buf = NULL;
318
319 kfree(mqrq_prev->sg);
320 mqrq_prev->sg = NULL;
321 kfree(mqrq_prev->bounce_buf);
322 mqrq_prev->bounce_buf = NULL;
323
324 blk_cleanup_queue(mq->queue);
325 return ret;
326 }
327
mmc_cleanup_queue(struct mmc_queue * mq)328 void mmc_cleanup_queue(struct mmc_queue *mq)
329 {
330 struct request_queue *q = mq->queue;
331 unsigned long flags;
332 struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
333 struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
334
335 /* Make sure the queue isn't suspended, as that will deadlock */
336 mmc_queue_resume(mq);
337
338 /* Then terminate our worker thread */
339 kthread_stop(mq->thread);
340
341 /* Empty the queue */
342 spin_lock_irqsave(q->queue_lock, flags);
343 q->queuedata = NULL;
344 blk_start_queue(q);
345 spin_unlock_irqrestore(q->queue_lock, flags);
346
347 kfree(mqrq_cur->bounce_sg);
348 mqrq_cur->bounce_sg = NULL;
349
350 kfree(mqrq_cur->sg);
351 mqrq_cur->sg = NULL;
352
353 kfree(mqrq_cur->bounce_buf);
354 mqrq_cur->bounce_buf = NULL;
355
356 kfree(mqrq_prev->bounce_sg);
357 mqrq_prev->bounce_sg = NULL;
358
359 kfree(mqrq_prev->sg);
360 mqrq_prev->sg = NULL;
361
362 kfree(mqrq_prev->bounce_buf);
363 mqrq_prev->bounce_buf = NULL;
364
365 mq->card = NULL;
366 }
367 EXPORT_SYMBOL(mmc_cleanup_queue);
368
mmc_packed_init(struct mmc_queue * mq,struct mmc_card * card)369 int mmc_packed_init(struct mmc_queue *mq, struct mmc_card *card)
370 {
371 struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
372 struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
373 int ret = 0;
374
375
376 mqrq_cur->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
377 if (!mqrq_cur->packed) {
378 pr_warn("%s: unable to allocate packed cmd for mqrq_cur\n",
379 mmc_card_name(card));
380 ret = -ENOMEM;
381 goto out;
382 }
383
384 mqrq_prev->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
385 if (!mqrq_prev->packed) {
386 pr_warn("%s: unable to allocate packed cmd for mqrq_prev\n",
387 mmc_card_name(card));
388 kfree(mqrq_cur->packed);
389 mqrq_cur->packed = NULL;
390 ret = -ENOMEM;
391 goto out;
392 }
393
394 INIT_LIST_HEAD(&mqrq_cur->packed->list);
395 INIT_LIST_HEAD(&mqrq_prev->packed->list);
396
397 out:
398 return ret;
399 }
400
mmc_packed_clean(struct mmc_queue * mq)401 void mmc_packed_clean(struct mmc_queue *mq)
402 {
403 struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
404 struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
405
406 kfree(mqrq_cur->packed);
407 mqrq_cur->packed = NULL;
408 kfree(mqrq_prev->packed);
409 mqrq_prev->packed = NULL;
410 }
411
412 /**
413 * mmc_queue_suspend - suspend a MMC request queue
414 * @mq: MMC queue to suspend
415 *
416 * Stop the block request queue, and wait for our thread to
417 * complete any outstanding requests. This ensures that we
418 * won't suspend while a request is being processed.
419 */
mmc_queue_suspend(struct mmc_queue * mq)420 void mmc_queue_suspend(struct mmc_queue *mq)
421 {
422 struct request_queue *q = mq->queue;
423 unsigned long flags;
424
425 if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
426 mq->flags |= MMC_QUEUE_SUSPENDED;
427
428 spin_lock_irqsave(q->queue_lock, flags);
429 blk_stop_queue(q);
430 spin_unlock_irqrestore(q->queue_lock, flags);
431
432 down(&mq->thread_sem);
433 }
434 }
435
436 /**
437 * mmc_queue_resume - resume a previously suspended MMC request queue
438 * @mq: MMC queue to resume
439 */
mmc_queue_resume(struct mmc_queue * mq)440 void mmc_queue_resume(struct mmc_queue *mq)
441 {
442 struct request_queue *q = mq->queue;
443 unsigned long flags;
444
445 if (mq->flags & MMC_QUEUE_SUSPENDED) {
446 mq->flags &= ~MMC_QUEUE_SUSPENDED;
447
448 up(&mq->thread_sem);
449
450 spin_lock_irqsave(q->queue_lock, flags);
451 blk_start_queue(q);
452 spin_unlock_irqrestore(q->queue_lock, flags);
453 }
454 }
455
mmc_queue_packed_map_sg(struct mmc_queue * mq,struct mmc_packed * packed,struct scatterlist * sg,enum mmc_packed_type cmd_type)456 static unsigned int mmc_queue_packed_map_sg(struct mmc_queue *mq,
457 struct mmc_packed *packed,
458 struct scatterlist *sg,
459 enum mmc_packed_type cmd_type)
460 {
461 struct scatterlist *__sg = sg;
462 unsigned int sg_len = 0;
463 struct request *req;
464
465 if (mmc_packed_wr(cmd_type)) {
466 unsigned int hdr_sz = mmc_large_sector(mq->card) ? 4096 : 512;
467 unsigned int max_seg_sz = queue_max_segment_size(mq->queue);
468 unsigned int len, remain, offset = 0;
469 u8 *buf = (u8 *)packed->cmd_hdr;
470
471 remain = hdr_sz;
472 do {
473 len = min(remain, max_seg_sz);
474 sg_set_buf(__sg, buf + offset, len);
475 offset += len;
476 remain -= len;
477 (__sg++)->page_link &= ~0x02;
478 sg_len++;
479 } while (remain);
480 }
481
482 list_for_each_entry(req, &packed->list, queuelist) {
483 sg_len += blk_rq_map_sg(mq->queue, req, __sg);
484 __sg = sg + (sg_len - 1);
485 (__sg++)->page_link &= ~0x02;
486 }
487 sg_mark_end(sg + (sg_len - 1));
488 return sg_len;
489 }
490
491 /*
492 * Prepare the sg list(s) to be handed of to the host driver
493 */
mmc_queue_map_sg(struct mmc_queue * mq,struct mmc_queue_req * mqrq)494 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
495 {
496 unsigned int sg_len;
497 size_t buflen;
498 struct scatterlist *sg;
499 enum mmc_packed_type cmd_type;
500 int i;
501
502 cmd_type = mqrq->cmd_type;
503
504 if (!mqrq->bounce_buf) {
505 if (mmc_packed_cmd(cmd_type))
506 return mmc_queue_packed_map_sg(mq, mqrq->packed,
507 mqrq->sg, cmd_type);
508 else
509 return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
510 }
511
512 BUG_ON(!mqrq->bounce_sg);
513
514 if (mmc_packed_cmd(cmd_type))
515 sg_len = mmc_queue_packed_map_sg(mq, mqrq->packed,
516 mqrq->bounce_sg, cmd_type);
517 else
518 sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
519
520 mqrq->bounce_sg_len = sg_len;
521
522 buflen = 0;
523 for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
524 buflen += sg->length;
525
526 sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen);
527
528 return 1;
529 }
530
531 /*
532 * If writing, bounce the data to the buffer before the request
533 * is sent to the host driver
534 */
mmc_queue_bounce_pre(struct mmc_queue_req * mqrq)535 void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq)
536 {
537 if (!mqrq->bounce_buf)
538 return;
539
540 if (rq_data_dir(mqrq->req) != WRITE)
541 return;
542
543 sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
544 mqrq->bounce_buf, mqrq->sg[0].length);
545 }
546
547 /*
548 * If reading, bounce the data from the buffer after the request
549 * has been handled by the host driver
550 */
mmc_queue_bounce_post(struct mmc_queue_req * mqrq)551 void mmc_queue_bounce_post(struct mmc_queue_req *mqrq)
552 {
553 if (!mqrq->bounce_buf)
554 return;
555
556 if (rq_data_dir(mqrq->req) != READ)
557 return;
558
559 sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
560 mqrq->bounce_buf, mqrq->sg[0].length);
561 }
562