aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mmc/card/queue.c
blob: fa9632eb63f14cc9af971f290989f13263c3cbfd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
/*
 *  linux/drivers/mmc/card/queue.c
 *
 *  Copyright (C) 2003 Russell King, All Rights Reserved.
 *  Copyright 2006-2007 Pierre Ossman
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/scatterlist.h>

#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
#include "queue.h"

#define MMC_QUEUE_BOUNCESZ	65536

/*
 * Prepare a MMC request. This just filters out odd stuff.
 */
static int mmc_prep_request(struct request_queue *q, struct request *req)
{
	struct mmc_queue *mq = q->queuedata;

	/*
	 * We only like normal block requests and discards.
	 */
	if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) {
		blk_dump_rq_flags(req, "MMC bad request");
		return BLKPREP_KILL;
	}

	if (mq && mmc_card_removed(mq->card))
		return BLKPREP_KILL;

	req->cmd_flags |= REQ_DONTPREP;

	return BLKPREP_OK;
}

static int mmc_queue_thread(void *d)
{
	struct mmc_queue *mq = d;
	struct request_queue *q = mq->queue;

	current->flags |= PF_MEMALLOC;

	down(&mq->thread_sem);
	do {
		struct request *req = NULL;
		struct mmc_queue_req *tmp;
		unsigned int cmd_flags = 0;

		spin_lock_irq(q->queue_lock);
		set_current_state(TASK_INTERRUPTIBLE);
		req = blk_fetch_request(q);
		mq->mqrq_cur->req = req;
		spin_unlock_irq(q->queue_lock);

		if (req || mq->mqrq_prev->req) {
			set_current_state(TASK_RUNNING);
			cmd_flags = req ? req->cmd_flags : 0;
			mq->issue_fn(mq, req);
			if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
				mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
				continue; /* fetch again */
			}

			/*
			 * Current request becomes previous request
			 * and vice versa.
			 * In case of special requests, current request
			 * has been finished. Do not assign it to previous
			 * request.
			 */
			if (cmd_flags & MMC_REQ_SPECIAL_MASK)
				mq->mqrq_cur->req = NULL;

			mq->mqrq_prev->brq.mrq.data = NULL;
			mq->mqrq_prev->req = NULL;
			tmp = mq->mqrq_prev;
			mq->mqrq_prev = mq->mqrq_cur;
			mq->mqrq_cur = tmp;
		} else {
			if (kthread_should_stop()) {
				set_current_state(TASK_RUNNING);
				break;
			}
			up(&mq->thread_sem);
			schedule();
			down(&mq->thread_sem);
		}
	} while (1);
	up(&mq->thread_sem);

	return 0;
}

/*
 * Generic MMC request handler.  This is called for any queue on a
 * particular host.  When the host is not busy, we look for a request
 * on any queue on this host, and attempt to issue it.  This may
 * not be the queue we were asked to process.
 */
static void mmc_request_fn(struct request_queue *q)
{
	struct mmc_queue *mq = q->queuedata;
	struct request *req;
	unsigned long flags;
	struct mmc_context_info *cntx;

	if (!mq) {
		while ((req = blk_fetch_request(q)) != NULL) {
			req->cmd_flags |= REQ_QUIET;
			__blk_end_request_all(req, -EIO);
		}
		return;
	}

	cntx = &mq->card->host->context_info;
	if (!mq->mqrq_cur->req && mq->mqrq_prev->req) {
		/*
		 * New MMC request arrived when MMC thread may be
		 * blocked on the previous request to be complete
		 * with no current request fetched
		 */
		spin_lock_irqsave(&cntx->lock, flags);
		if (cntx->is_waiting_last_req) {
			cntx->is_new_req = true;
			wake_up_interruptible(&cntx->wait);
		}
		spin_unlock_irqrestore(&cntx->lock, flags);
	} else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
		wake_up_process(mq->thread);
}

static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
{
	struct scatterlist *sg;

	sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
	if (!sg)
		*err = -ENOMEM;
	else {
		*err = 0;
		sg_init_table(sg, sg_len);
	}

	return sg;
}

static void mmc_queue_setup_discard(struct request_queue *q,
				    struct mmc_card *card)
{
	unsigned max_discard;

	max_discard = mmc_calc_max_discard(card);
	if (!max_discard)
		return;

	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	q->limits.max_discard_sectors = max_discard;
	if (card->erased_byte == 0 && !mmc_can_discard(card))
		q->limits.discard_zeroes_data = 1;
	q->limits.discard_granularity = card->pref_erase << 9;
	/* granularity must not be greater than max. discard */
	if (card->pref_erase > max_discard)
		q->limits.discard_granularity = 0;
	if (mmc_can_secure_erase_trim(card))
		queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);
}

/**
 * mmc_init_queue - initialise a queue structure.
 * @mq: mmc queue
 * @card: mmc card to attach this queue
 * @lock: queue lock
 * @subname: partition subname
 *
 * Initialise a MMC card request queue.
 */
int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
		   spinlock_t *lock, const char *subname)
{
	struct mmc_host *host = card->host;
	u64 limit = BLK_BOUNCE_HIGH;
	int ret;
	struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];

	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
		limit = *mmc_dev(host)->dma_mask;

	mq->card = card;
	mq->queue = blk_init_queue(mmc_request_fn, lock);
	if (!mq->queue)
		return -ENOMEM;

	mq->mqrq_cur = mqrq_cur;
	mq->mqrq_prev = mqrq_prev;
	mq->queue->queuedata = mq;

	blk_queue_prep_rq(mq->queue, mmc_prep_request);
	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
	if (mmc_can_erase(card))
		mmc_queue_setup_discard(mq->queue, card);

#ifdef CONFIG_MMC_BLOCK_BOUNCE
	if (host->max_segs == 1) {
		unsigned int bouncesz;

		bouncesz = MMC_QUEUE_BOUNCESZ;

		if (bouncesz > host->max_req_size)
			bouncesz = host->max_req_size;
		if (bouncesz > host->max_seg_size)
			bouncesz = host->max_seg_size;
		if (bouncesz > (host->max_blk_count * 512))
			bouncesz = host->max_blk_count * 512;

		if (bouncesz > 512) {
			mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
			if (!mqrq_cur->bounce_buf) {
				pr_warning("%s: unable to "
					"allocate bounce cur buffer\n",
					mmc_card_name(card));
			}
			mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
			if (!mqrq_prev->bounce_buf) {
				pr_warning("%s: unable to "
					"allocate bounce prev buffer\n",
					mmc_card_name(card));
				kfree(mqrq_cur->bounce_buf);
				mqrq_cur->bounce_buf = NULL;
			}
		}

		if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {
			blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
			blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
			blk_queue_max_segments(mq->queue, bouncesz / 512);
			blk_queue_max_segment_size(mq->queue, bouncesz);

			mqrq_cur->sg = mmc_alloc_sg(1, &ret);
			if (ret)
				goto cleanup_queue;

			mqrq_cur->bounce_sg =
				mmc_alloc_sg(bouncesz / 512, &ret);
			if (ret)
				goto cleanup_queue;

			mqrq_prev->sg = mmc_alloc_sg(1, &ret);
			if (ret)
				goto cleanup_queue;

			mqrq_prev->bounce_sg =
				mmc_alloc_sg(bouncesz / 512, &ret);
			if (ret)
				goto cleanup_queue;
		}
	}
#endif

	if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {
		blk_queue_bounce_limit(mq->queue, limit);
		blk_queue_max_hw_sectors(mq->queue,
			min(host->max_blk_count, host->max_req_size / 512));
		blk_queue_max_segments(mq->queue, host->max_segs);
		blk_queue_max_segment_size(mq->queue, host->max_seg_size);

		mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);
		if (ret)
			goto cleanup_queue;


		mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
		if (ret)
			goto cleanup_queue;
	}

	sema_init(&mq->thread_sem, 1);

	mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
		host->index, subname ? subname : "");

	if (IS_ERR(mq->thread)) {
		ret = PTR_ERR(mq->thread);
		goto free_bounce_sg;
	}

	return 0;
 free_bounce_sg:
	kfree(mqrq_cur->bounce_sg);
	mqrq_cur->bounce_sg = NULL;
	kfree(mqrq_prev->bounce_sg);
	mqrq_prev->bounce_sg = NULL;

 cleanup_queue:
	kfree(mqrq_cur->sg);
	mqrq_cur->sg = NULL;
	kfree(mqrq_cur->bounce_buf);
	mqrq_cur->bounce_buf = NULL;

	kfree(mqrq_prev->sg);
	mqrq_prev->sg = NULL;
	kfree(mqrq_prev->bounce_buf);
	mqrq_prev->bounce_buf = NULL;

	blk_cleanup_queue(mq->queue);
	return ret;
}

void mmc_cleanup_queue(struct mmc_queue *mq)
{
	struct request_queue *q = mq->queue;
	unsigned long flags;
	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;

	/* Make sure the queue isn't suspended, as that will deadlock */
	mmc_queue_resume(mq);

	/* Then terminate our worker thread */
	kthread_stop(mq->thread);

	/* Empty the queue */
	spin_lock_irqsave(q->queue_lock, flags);
	q->queuedata = NULL;
	blk_start_queue(q);
	spin_unlock_irqrestore(q->queue_lock, flags);

	kfree(mqrq_cur->bounce_sg);
	mqrq_cur->bounce_sg = NULL;

	kfree(mqrq_cur->sg);
	mqrq_cur->sg = NULL;

	kfree(mqrq_cur->bounce_buf);
	mqrq_cur->bounce_buf = NULL;

	kfree(mqrq_prev->bounce_sg);
	mqrq_prev->bounce_sg = NULL;

	kfree(mqrq_prev->sg);
	mqrq_prev->sg = NULL;

	kfree(mqrq_prev->bounce_buf);
	mqrq_prev->bounce_buf = NULL;

	mq->card = NULL;
}
EXPORT_SYMBOL(mmc_cleanup_queue);

int mmc_packed_init(struct mmc_queue *mq, struct mmc_card *card)
{
	struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
	int ret = 0;


	mqrq_cur->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
	if (!mqrq_cur->packed) {
		pr_warn("%s: unable to allocate packed cmd for mqrq_cur\n",
			mmc_card_name(card));
		ret = -ENOMEM;
		goto out;
	}

	mqrq_prev->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
	if (!mqrq_prev->packed) {
		pr_warn("%s: unable to allocate packed cmd for mqrq_prev\n",
			mmc_card_name(card));
		kfree(mqrq_cur->packed);
		mqrq_cur->packed = NULL;
		ret = -ENOMEM;
		goto out;
	}

	INIT_LIST_HEAD(&mqrq_cur->packed->list);
	INIT_LIST_HEAD(&mqrq_prev->packed->list);

out:
	return ret;
}

void mmc_packed_clean(struct mmc_queue *mq)
{
	struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];

	kfree(mqrq_cur->packed);
	mqrq_cur->packed = NULL;
	kfree(mqrq_prev->packed);
	mqrq_prev->packed = NULL;
}

/**
 * mmc_queue_suspend - suspend a MMC request queue
 * @mq: MMC queue to suspend
 *
 * Stop the block request queue, and wait for our thread to
 * complete any outstanding requests.  This ensures that we
 * won't suspend while a request is being processed.
 */
void mmc_queue_suspend(struct mmc_queue *mq)
{
	struct request_queue *q = mq->queue;
	unsigned long flags;

	if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
		mq->flags |= MMC_QUEUE_SUSPENDED;

		spin_lock_irqsave(q->queue_lock, flags);
		blk_stop_queue(q);
		spin_unlock_irqrestore(q->queue_lock, flags);

		down(&mq->thread_sem);
	}
}

/**
 * mmc_queue_resume - resume a previously suspended MMC request queue
 * @mq: MMC queue to resume
 */
void mmc_queue_resume(struct mmc_queue *mq)
{
	struct request_queue *q = mq->queue;
	unsigned long flags;

	if (mq->flags & MMC_QUEUE_SUSPENDED) {
		mq->flags &= ~MMC_QUEUE_SUSPENDED;

		up(&mq->thread_sem);

		spin_lock_irqsave(q->queue_lock, flags);
		blk_start_queue(q);
		spin_unlock_irqrestore(q->queue_lock, flags);
	}
}

static unsigned int mmc_queue_packed_map_sg(struct mmc_queue *mq,
					    struct mmc_packed *packed,
					    struct scatterlist *sg,
					    enum mmc_packed_type cmd_type)
{
	struct scatterlist *__sg = sg;
	unsigned int sg_len = 0;
	struct request *req;

	if (mmc_packed_wr(cmd_type)) {
		unsigned int hdr_sz = mmc_large_sector(mq->card) ? 4096 : 512;
		unsigned int max_seg_sz = queue_max_segment_size(mq->queue);
		unsigned int len, remain, offset = 0;
		u8 *buf = (u8 *)packed->cmd_hdr;

		remain = hdr_sz;
		do {
			len = min(remain, max_seg_sz);
			sg_set_buf(__sg, buf + offset, len);
			offset += len;
			remain -= len;
			(__sg++)->page_link &= ~0x02;
			sg_len++;
		} while (remain);
	}

	list_for_each_entry(req, &packed->list, queuelist) {
		sg_len += blk_rq_map_sg(mq->queue, req, __sg);
		__sg = sg + (sg_len - 1);
		(__sg++)->page_link &= ~0x02;
	}
	sg_mark_end(sg + (sg_len - 1));
	return sg_len;
}

/*
 * Prepare the sg list(s) to be handed of to the host driver
 */
unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
{
	unsigned int sg_len;
	size_t buflen;
	struct scatterlist *sg;
	enum mmc_packed_type cmd_type;
	int i;

	cmd_type = mqrq->cmd_type;

	if (!mqrq->bounce_buf) {
		if (mmc_packed_cmd(cmd_type))
			return mmc_queue_packed_map_sg(mq, mqrq->packed,
						       mqrq->sg, cmd_type);
		else
			return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
	}

	BUG_ON(!mqrq->bounce_sg);

	if (mmc_packed_cmd(cmd_type))
		sg_len = mmc_queue_packed_map_sg(mq, mqrq->packed,
						 mqrq->bounce_sg, cmd_type);
	else
		sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);

	mqrq->bounce_sg_len = sg_len;

	buflen = 0;
	for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
		buflen += sg->length;

	sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen);

	return 1;
}

/*
 * If writing, bounce the data to the buffer before the request
 * is sent to the host driver
 */
void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq)
{
	if (!mqrq->bounce_buf)
		return;

	if (rq_data_dir(mqrq->req) != WRITE)
		return;

	sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
		mqrq->bounce_buf, mqrq->sg[0].length);
}

/*
 * If reading, bounce the data from the buffer after the request
 * has been handled by the host driver
 */
void mmc_queue_bounce_post(struct mmc_queue_req *mqrq)
{
	if (!mqrq->bounce_buf)
		return;

	if (rq_data_dir(mqrq->req) != READ)
		return;

	sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
		mqrq->bounce_buf, mqrq->sg[0].length);
}