1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  Copyright (C) 2003 Russell King, All Rights Reserved.
4 *  Copyright 2006-2007 Pierre Ossman
5 */
6#include <linux/slab.h>
7#include <linux/module.h>
8#include <linux/blkdev.h>
9#include <linux/freezer.h>
10#include <linux/scatterlist.h>
11#include <linux/dma-mapping.h>
12#include <linux/backing-dev.h>
13
14#include <linux/mmc/card.h>
15#include <linux/mmc/host.h>
16
17#include "queue.h"
18#include "block.h"
19#include "core.h"
20#include "card.h"
21#include "crypto.h"
22#include "host.h"
23
24#define MMC_DMA_MAP_MERGE_SEGMENTS	512
25
26static inline bool mmc_cqe_dcmd_busy(struct mmc_queue *mq)
27{
28	/* Allow only 1 DCMD at a time */
29	return mq->in_flight[MMC_ISSUE_DCMD];
30}
31
32void mmc_cqe_check_busy(struct mmc_queue *mq)
33{
34	if ((mq->cqe_busy & MMC_CQE_DCMD_BUSY) && !mmc_cqe_dcmd_busy(mq))
35		mq->cqe_busy &= ~MMC_CQE_DCMD_BUSY;
36}
37
38static inline bool mmc_cqe_can_dcmd(struct mmc_host *host)
39{
40	return host->caps2 & MMC_CAP2_CQE_DCMD;
41}
42
43static enum mmc_issue_type mmc_cqe_issue_type(struct mmc_host *host,
44					      struct request *req)
45{
46	switch (req_op(req)) {
47	case REQ_OP_DRV_IN:
48	case REQ_OP_DRV_OUT:
49	case REQ_OP_DISCARD:
50	case REQ_OP_SECURE_ERASE:
51	case REQ_OP_WRITE_ZEROES:
52		return MMC_ISSUE_SYNC;
53	case REQ_OP_FLUSH:
54		return mmc_cqe_can_dcmd(host) ? MMC_ISSUE_DCMD : MMC_ISSUE_SYNC;
55	default:
56		return MMC_ISSUE_ASYNC;
57	}
58}
59
60enum mmc_issue_type mmc_issue_type(struct mmc_queue *mq, struct request *req)
61{
62	struct mmc_host *host = mq->card->host;
63
64	if (host->cqe_enabled && !host->hsq_enabled)
65		return mmc_cqe_issue_type(host, req);
66
67	if (req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_WRITE)
68		return MMC_ISSUE_ASYNC;
69
70	return MMC_ISSUE_SYNC;
71}
72
73static void __mmc_cqe_recovery_notifier(struct mmc_queue *mq)
74{
75	if (!mq->recovery_needed) {
76		mq->recovery_needed = true;
77		schedule_work(&mq->recovery_work);
78	}
79}
80
81void mmc_cqe_recovery_notifier(struct mmc_request *mrq)
82{
83	struct mmc_queue_req *mqrq = container_of(mrq, struct mmc_queue_req,
84						  brq.mrq);
85	struct request *req = mmc_queue_req_to_req(mqrq);
86	struct request_queue *q = req->q;
87	struct mmc_queue *mq = q->queuedata;
88	unsigned long flags;
89
90	spin_lock_irqsave(&mq->lock, flags);
91	__mmc_cqe_recovery_notifier(mq);
92	spin_unlock_irqrestore(&mq->lock, flags);
93}
94
95static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
96{
97	struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
98	struct mmc_request *mrq = &mqrq->brq.mrq;
99	struct mmc_queue *mq = req->q->queuedata;
100	struct mmc_host *host = mq->card->host;
101	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
102	bool recovery_needed = false;
103
104	switch (issue_type) {
105	case MMC_ISSUE_ASYNC:
106	case MMC_ISSUE_DCMD:
107		if (host->cqe_ops->cqe_timeout(host, mrq, &recovery_needed)) {
108			if (recovery_needed)
109				mmc_cqe_recovery_notifier(mrq);
110			return BLK_EH_RESET_TIMER;
111		}
112		/* The request has gone already */
113		return BLK_EH_DONE;
114	default:
115		/* Timeout is handled by mmc core */
116		return BLK_EH_RESET_TIMER;
117	}
118}
119
120static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req)
121{
122	struct request_queue *q = req->q;
123	struct mmc_queue *mq = q->queuedata;
124	struct mmc_card *card = mq->card;
125	struct mmc_host *host = card->host;
126	unsigned long flags;
127	bool ignore_tout;
128
129	spin_lock_irqsave(&mq->lock, flags);
130	ignore_tout = mq->recovery_needed || !host->cqe_enabled || host->hsq_enabled;
131	spin_unlock_irqrestore(&mq->lock, flags);
132
133	return ignore_tout ? BLK_EH_RESET_TIMER : mmc_cqe_timed_out(req);
134}
135
136static void mmc_mq_recovery_handler(struct work_struct *work)
137{
138	struct mmc_queue *mq = container_of(work, struct mmc_queue,
139					    recovery_work);
140	struct request_queue *q = mq->queue;
141	struct mmc_host *host = mq->card->host;
142
143	mmc_get_card(mq->card, &mq->ctx);
144
145	mq->in_recovery = true;
146
147	if (host->cqe_enabled && !host->hsq_enabled)
148		mmc_blk_cqe_recovery(mq);
149	else
150		mmc_blk_mq_recovery(mq);
151
152	mq->in_recovery = false;
153
154	spin_lock_irq(&mq->lock);
155	mq->recovery_needed = false;
156	spin_unlock_irq(&mq->lock);
157
158	if (host->hsq_enabled)
159		host->cqe_ops->cqe_recovery_finish(host);
160
161	mmc_put_card(mq->card, &mq->ctx);
162
163	blk_mq_run_hw_queues(q, true);
164}
165
166static struct scatterlist *mmc_alloc_sg(unsigned short sg_len, gfp_t gfp)
167{
168	struct scatterlist *sg;
169
170	sg = kmalloc_array(sg_len, sizeof(*sg), gfp);
171	if (sg)
172		sg_init_table(sg, sg_len);
173
174	return sg;
175}
176
177static void mmc_queue_setup_discard(struct mmc_card *card,
178		struct queue_limits *lim)
179{
180	unsigned max_discard;
181
182	max_discard = mmc_calc_max_discard(card);
183	if (!max_discard)
184		return;
185
186	lim->max_hw_discard_sectors = max_discard;
187	if (mmc_can_secure_erase_trim(card))
188		lim->max_secure_erase_sectors = max_discard;
189	if (mmc_can_trim(card) && card->erased_byte == 0)
190		lim->max_write_zeroes_sectors = max_discard;
191
192	/* granularity must not be greater than max. discard */
193	if (card->pref_erase > max_discard)
194		lim->discard_granularity = SECTOR_SIZE;
195	else
196		lim->discard_granularity = card->pref_erase << 9;
197}
198
199static unsigned short mmc_get_max_segments(struct mmc_host *host)
200{
201	return host->can_dma_map_merge ? MMC_DMA_MAP_MERGE_SEGMENTS :
202					 host->max_segs;
203}
204
205static int mmc_mq_init_request(struct blk_mq_tag_set *set, struct request *req,
206			       unsigned int hctx_idx, unsigned int numa_node)
207{
208	struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
209	struct mmc_queue *mq = set->driver_data;
210	struct mmc_card *card = mq->card;
211	struct mmc_host *host = card->host;
212
213	mq_rq->sg = mmc_alloc_sg(mmc_get_max_segments(host), GFP_KERNEL);
214	if (!mq_rq->sg)
215		return -ENOMEM;
216
217	return 0;
218}
219
220static void mmc_mq_exit_request(struct blk_mq_tag_set *set, struct request *req,
221				unsigned int hctx_idx)
222{
223	struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
224
225	kfree(mq_rq->sg);
226	mq_rq->sg = NULL;
227}
228
229static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
230				    const struct blk_mq_queue_data *bd)
231{
232	struct request *req = bd->rq;
233	struct request_queue *q = req->q;
234	struct mmc_queue *mq = q->queuedata;
235	struct mmc_card *card = mq->card;
236	struct mmc_host *host = card->host;
237	enum mmc_issue_type issue_type;
238	enum mmc_issued issued;
239	bool get_card, cqe_retune_ok;
240	blk_status_t ret;
241
242	if (mmc_card_removed(mq->card)) {
243		req->rq_flags |= RQF_QUIET;
244		return BLK_STS_IOERR;
245	}
246
247	issue_type = mmc_issue_type(mq, req);
248
249	spin_lock_irq(&mq->lock);
250
251	if (mq->recovery_needed || mq->busy) {
252		spin_unlock_irq(&mq->lock);
253		return BLK_STS_RESOURCE;
254	}
255
256	switch (issue_type) {
257	case MMC_ISSUE_DCMD:
258		if (mmc_cqe_dcmd_busy(mq)) {
259			mq->cqe_busy |= MMC_CQE_DCMD_BUSY;
260			spin_unlock_irq(&mq->lock);
261			return BLK_STS_RESOURCE;
262		}
263		break;
264	case MMC_ISSUE_ASYNC:
265		if (host->hsq_enabled && mq->in_flight[issue_type] > host->hsq_depth) {
266			spin_unlock_irq(&mq->lock);
267			return BLK_STS_RESOURCE;
268		}
269		break;
270	default:
271		/*
272		 * Timeouts are handled by mmc core, and we don't have a host
273		 * API to abort requests, so we can't handle the timeout anyway.
274		 * However, when the timeout happens, blk_mq_complete_request()
275		 * no longer works (to stop the request disappearing under us).
276		 * To avoid racing with that, set a large timeout.
277		 */
278		req->timeout = 600 * HZ;
279		break;
280	}
281
282	/* Parallel dispatch of requests is not supported at the moment */
283	mq->busy = true;
284
285	mq->in_flight[issue_type] += 1;
286	get_card = (mmc_tot_in_flight(mq) == 1);
287	cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1);
288
289	spin_unlock_irq(&mq->lock);
290
291	if (!(req->rq_flags & RQF_DONTPREP)) {
292		req_to_mmc_queue_req(req)->retries = 0;
293		req->rq_flags |= RQF_DONTPREP;
294	}
295
296	if (get_card)
297		mmc_get_card(card, &mq->ctx);
298
299	if (host->cqe_enabled) {
300		host->retune_now = host->need_retune && cqe_retune_ok &&
301				   !host->hold_retune;
302	}
303
304	blk_mq_start_request(req);
305
306	issued = mmc_blk_mq_issue_rq(mq, req);
307
308	switch (issued) {
309	case MMC_REQ_BUSY:
310		ret = BLK_STS_RESOURCE;
311		break;
312	case MMC_REQ_FAILED_TO_START:
313		ret = BLK_STS_IOERR;
314		break;
315	default:
316		ret = BLK_STS_OK;
317		break;
318	}
319
320	if (issued != MMC_REQ_STARTED) {
321		bool put_card = false;
322
323		spin_lock_irq(&mq->lock);
324		mq->in_flight[issue_type] -= 1;
325		if (mmc_tot_in_flight(mq) == 0)
326			put_card = true;
327		mq->busy = false;
328		spin_unlock_irq(&mq->lock);
329		if (put_card)
330			mmc_put_card(card, &mq->ctx);
331	} else {
332		WRITE_ONCE(mq->busy, false);
333	}
334
335	return ret;
336}
337
338static const struct blk_mq_ops mmc_mq_ops = {
339	.queue_rq	= mmc_mq_queue_rq,
340	.init_request	= mmc_mq_init_request,
341	.exit_request	= mmc_mq_exit_request,
342	.complete	= mmc_blk_mq_complete,
343	.timeout	= mmc_mq_timed_out,
344};
345
346static struct gendisk *mmc_alloc_disk(struct mmc_queue *mq,
347		struct mmc_card *card)
348{
349	struct mmc_host *host = card->host;
350	struct queue_limits lim = { };
351	struct gendisk *disk;
352
353	if (mmc_can_erase(card))
354		mmc_queue_setup_discard(card, &lim);
355
356	lim.max_hw_sectors = min(host->max_blk_count, host->max_req_size / 512);
357
358	if (mmc_card_mmc(card) && card->ext_csd.data_sector_size)
359		lim.logical_block_size = card->ext_csd.data_sector_size;
360	else
361		lim.logical_block_size = 512;
362
363	WARN_ON_ONCE(lim.logical_block_size != 512 &&
364		     lim.logical_block_size != 4096);
365
366	/*
367	 * Setting a virt_boundary implicity sets a max_segment_size, so try
368	 * to set the hardware one here.
369	 */
370	if (host->can_dma_map_merge) {
371		lim.virt_boundary_mask = dma_get_merge_boundary(mmc_dev(host));
372		lim.max_segments = MMC_DMA_MAP_MERGE_SEGMENTS;
373	} else {
374		lim.max_segment_size =
375			round_down(host->max_seg_size, lim.logical_block_size);
376		lim.max_segments = host->max_segs;
377	}
378
379	disk = blk_mq_alloc_disk(&mq->tag_set, &lim, mq);
380	if (IS_ERR(disk))
381		return disk;
382	mq->queue = disk->queue;
383
384	if (mmc_host_is_spi(host) && host->use_spi_crc)
385		blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, mq->queue);
386	blk_queue_rq_timeout(mq->queue, 60 * HZ);
387
388	blk_queue_flag_set(QUEUE_FLAG_NONROT, mq->queue);
389	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue);
390
391	dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue));
392
393	INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
394	INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);
395
396	mutex_init(&mq->complete_lock);
397
398	init_waitqueue_head(&mq->wait);
399
400	mmc_crypto_setup_queue(mq->queue, host);
401	return disk;
402}
403
404static inline bool mmc_merge_capable(struct mmc_host *host)
405{
406	return host->caps2 & MMC_CAP2_MERGE_CAPABLE;
407}
408
409/* Set queue depth to get a reasonable value for q->nr_requests */
410#define MMC_QUEUE_DEPTH 64
411
412/**
413 * mmc_init_queue - initialise a queue structure.
414 * @mq: mmc queue
415 * @card: mmc card to attach this queue
416 *
417 * Initialise a MMC card request queue.
418 */
419struct gendisk *mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card)
420{
421	struct mmc_host *host = card->host;
422	struct gendisk *disk;
423	int ret;
424
425	mq->card = card;
426
427	spin_lock_init(&mq->lock);
428
429	memset(&mq->tag_set, 0, sizeof(mq->tag_set));
430	mq->tag_set.ops = &mmc_mq_ops;
431	/*
432	 * The queue depth for CQE must match the hardware because the request
433	 * tag is used to index the hardware queue.
434	 */
435	if (host->cqe_enabled && !host->hsq_enabled)
436		mq->tag_set.queue_depth =
437			min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
438	else
439		mq->tag_set.queue_depth = MMC_QUEUE_DEPTH;
440	mq->tag_set.numa_node = NUMA_NO_NODE;
441	mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING;
442	mq->tag_set.nr_hw_queues = 1;
443	mq->tag_set.cmd_size = sizeof(struct mmc_queue_req);
444	mq->tag_set.driver_data = mq;
445
446	/*
447	 * Since blk_mq_alloc_tag_set() calls .init_request() of mmc_mq_ops,
448	 * the host->can_dma_map_merge should be set before to get max_segs
449	 * from mmc_get_max_segments().
450	 */
451	if (mmc_merge_capable(host) &&
452	    host->max_segs < MMC_DMA_MAP_MERGE_SEGMENTS &&
453	    dma_get_merge_boundary(mmc_dev(host)))
454		host->can_dma_map_merge = 1;
455	else
456		host->can_dma_map_merge = 0;
457
458	ret = blk_mq_alloc_tag_set(&mq->tag_set);
459	if (ret)
460		return ERR_PTR(ret);
461
462
463	disk = mmc_alloc_disk(mq, card);
464	if (IS_ERR(disk))
465		blk_mq_free_tag_set(&mq->tag_set);
466	return disk;
467}
468
469void mmc_queue_suspend(struct mmc_queue *mq)
470{
471	blk_mq_quiesce_queue(mq->queue);
472
473	/*
474	 * The host remains claimed while there are outstanding requests, so
475	 * simply claiming and releasing here ensures there are none.
476	 */
477	mmc_claim_host(mq->card->host);
478	mmc_release_host(mq->card->host);
479}
480
481void mmc_queue_resume(struct mmc_queue *mq)
482{
483	blk_mq_unquiesce_queue(mq->queue);
484}
485
486void mmc_cleanup_queue(struct mmc_queue *mq)
487{
488	struct request_queue *q = mq->queue;
489
490	/*
491	 * The legacy code handled the possibility of being suspended,
492	 * so do that here too.
493	 */
494	if (blk_queue_quiesced(q))
495		blk_mq_unquiesce_queue(q);
496
497	/*
498	 * If the recovery completes the last (and only remaining) request in
499	 * the queue, and the card has been removed, we could end up here with
500	 * the recovery not quite finished yet, so cancel it.
501	 */
502	cancel_work_sync(&mq->recovery_work);
503
504	blk_mq_free_tag_set(&mq->tag_set);
505
506	/*
507	 * A request can be completed before the next request, potentially
508	 * leaving a complete_work with nothing to do. Such a work item might
509	 * still be queued at this point. Flush it.
510	 */
511	flush_work(&mq->complete_work);
512
513	mq->card = NULL;
514}
515
516/*
517 * Prepare the sg list(s) to be handed of to the host driver
518 */
519unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
520{
521	struct request *req = mmc_queue_req_to_req(mqrq);
522
523	return blk_rq_map_sg(mq->queue, req, mqrq->sg);
524}
525