drivers/mmc/core/queue.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2003 Russell King, All Rights Reserved.
  *  Copyright 2006-2007 Pierre Ossman
  */
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/blkdev.h>
 #include <linux/freezer.h>
 #include <linux/scatterlist.h>
 #include <linux/dma-mapping.h>
 #include <linux/backing-dev.h>

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

 #include "queue.h"
 #include "block.h"
 #include "core.h"
 #include "card.h"
 #include "crypto.h"
 #include "host.h"

 #define MMC_DMA_MAP_MERGE_SEGMENTS	512

 static inline bool mmc_cqe_dcmd_busy(struct mmc_queue *mq)
 {
 	/* Allow only 1 DCMD at a time */
 	return mq->in_flight[MMC_ISSUE_DCMD];
 }

 void mmc_cqe_check_busy(struct mmc_queue *mq)
 {
 	if ((mq->cqe_busy & MMC_CQE_DCMD_BUSY) && !mmc_cqe_dcmd_busy(mq))
 		mq->cqe_busy &= ~MMC_CQE_DCMD_BUSY;
 }

 static inline bool mmc_cqe_can_dcmd(struct mmc_host *host)
 {
 	return host->caps2 & MMC_CAP2_CQE_DCMD;
 }

 static enum mmc_issue_type mmc_cqe_issue_type(struct mmc_host *host,
 					      struct request *req)
 {
 	switch (req_op(req)) {
 	case REQ_OP_DRV_IN:
 	case REQ_OP_DRV_OUT:
 	case REQ_OP_DISCARD:
 	case REQ_OP_SECURE_ERASE:
 	case REQ_OP_WRITE_ZEROES:
 		return MMC_ISSUE_SYNC;
 	case REQ_OP_FLUSH:
 		return mmc_cqe_can_dcmd(host) ? MMC_ISSUE_DCMD : MMC_ISSUE_SYNC;
 	default:
 		return MMC_ISSUE_ASYNC;
 	}
 }

 enum mmc_issue_type mmc_issue_type(struct mmc_queue *mq, struct request *req)
 {
 	struct mmc_host *host = mq->card->host;

 	if (host->cqe_enabled && !host->hsq_enabled)
 		return mmc_cqe_issue_type(host, req);

 	if (req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_WRITE)
 		return MMC_ISSUE_ASYNC;

 	return MMC_ISSUE_SYNC;
 }

 static void __mmc_cqe_recovery_notifier(struct mmc_queue *mq)
 {
 	if (!mq->recovery_needed) {
 		mq->recovery_needed = true;
 		schedule_work(&mq->recovery_work);
 	}
 }

 void mmc_cqe_recovery_notifier(struct mmc_request *mrq)
 {
 	struct mmc_queue_req *mqrq = container_of(mrq, struct mmc_queue_req,
 						  brq.mrq);
 	struct request *req = mmc_queue_req_to_req(mqrq);
 	struct request_queue *q = req->q;
 	struct mmc_queue *mq = q->queuedata;
 	unsigned long flags;

 	spin_lock_irqsave(&mq->lock, flags);
 	__mmc_cqe_recovery_notifier(mq);
 	spin_unlock_irqrestore(&mq->lock, flags);
 }

 static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
 {
 	struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
 	struct mmc_request *mrq = &mqrq->brq.mrq;
 	struct mmc_queue *mq = req->q->queuedata;
 	struct mmc_host *host = mq->card->host;
 	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
 	bool recovery_needed = false;

 	switch (issue_type) {
 	case MMC_ISSUE_ASYNC:
 	case MMC_ISSUE_DCMD:
 		if (host->cqe_ops->cqe_timeout(host, mrq, &recovery_needed)) {
 			if (recovery_needed)
 				mmc_cqe_recovery_notifier(mrq);
 			return BLK_EH_RESET_TIMER;
 		}
 		/* The request has gone already */
 		return BLK_EH_DONE;
 	default:
 		/* Timeout is handled by mmc core */
 		return BLK_EH_RESET_TIMER;
 	}
 }

 static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req)
 {
 	struct request_queue *q = req->q;
 	struct mmc_queue *mq = q->queuedata;
 	struct mmc_card *card = mq->card;
 	struct mmc_host *host = card->host;
 	unsigned long flags;
 	bool ignore_tout;

 	spin_lock_irqsave(&mq->lock, flags);
 	ignore_tout = mq->recovery_needed || !host->cqe_enabled || host->hsq_enabled;
 	spin_unlock_irqrestore(&mq->lock, flags);

 	return ignore_tout ? BLK_EH_RESET_TIMER : mmc_cqe_timed_out(req);
 }

 static void mmc_mq_recovery_handler(struct work_struct *work)
 {
 	struct mmc_queue *mq = container_of(work, struct mmc_queue,
 					    recovery_work);
 	struct request_queue *q = mq->queue;
 	struct mmc_host *host = mq->card->host;

 	mmc_get_card(mq->card, &mq->ctx);

 	mq->in_recovery = true;

 	if (host->cqe_enabled && !host->hsq_enabled)
 		mmc_blk_cqe_recovery(mq);
 	else
 		mmc_blk_mq_recovery(mq);

 	mq->in_recovery = false;

 	spin_lock_irq(&mq->lock);
 	mq->recovery_needed = false;
 	spin_unlock_irq(&mq->lock);

 	if (host->hsq_enabled)
 		host->cqe_ops->cqe_recovery_finish(host);

 	mmc_put_card(mq->card, &mq->ctx);

 	blk_mq_run_hw_queues(q, true);
 }

 static struct scatterlist *mmc_alloc_sg(unsigned short sg_len, gfp_t gfp)
 {
 	struct scatterlist *sg;

 	sg = kmalloc_array(sg_len, sizeof(*sg), gfp);
 	if (sg)
 		sg_init_table(sg, sg_len);

 	return sg;
 }

 static void mmc_queue_setup_discard(struct mmc_card *card,
 		struct queue_limits *lim)
 {
 	unsigned max_discard;

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

 	lim->max_hw_discard_sectors = max_discard;
 	if (mmc_can_secure_erase_trim(card))
 		lim->max_secure_erase_sectors = max_discard;
 	if (mmc_can_trim(card) && card->erased_byte == 0)
 		lim->max_write_zeroes_sectors = max_discard;

 	/* granularity must not be greater than max. discard */
 	if (card->pref_erase > max_discard)
 		lim->discard_granularity = SECTOR_SIZE;
 	else
 		lim->discard_granularity = card->pref_erase << 9;
 }

 static unsigned short mmc_get_max_segments(struct mmc_host *host)
 {
 	return host->can_dma_map_merge ? MMC_DMA_MAP_MERGE_SEGMENTS :
 					 host->max_segs;
 }

 static int mmc_mq_init_request(struct blk_mq_tag_set *set, struct request *req,
 			       unsigned int hctx_idx, unsigned int numa_node)
 {
 	struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
 	struct mmc_queue *mq = set->driver_data;
 	struct mmc_card *card = mq->card;
 	struct mmc_host *host = card->host;

 	mq_rq->sg = mmc_alloc_sg(mmc_get_max_segments(host), GFP_KERNEL);
 	if (!mq_rq->sg)
 		return -ENOMEM;

 	return 0;
 }

 static void mmc_mq_exit_request(struct blk_mq_tag_set *set, struct request *req,
 				unsigned int hctx_idx)
 {
 	struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);

 	kfree(mq_rq->sg);
 	mq_rq->sg = NULL;
 }

 static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
 				    const struct blk_mq_queue_data *bd)
 {
 	struct request *req = bd->rq;
 	struct request_queue *q = req->q;
 	struct mmc_queue *mq = q->queuedata;
 	struct mmc_card *card = mq->card;
 	struct mmc_host *host = card->host;
 	enum mmc_issue_type issue_type;
 	enum mmc_issued issued;
 	bool get_card, cqe_retune_ok;
 	blk_status_t ret;

 	if (mmc_card_removed(mq->card)) {
 		req->rq_flags |= RQF_QUIET;
 		return BLK_STS_IOERR;
 	}

 	issue_type = mmc_issue_type(mq, req);

 	spin_lock_irq(&mq->lock);

 	if (mq->recovery_needed || mq->busy) {
 		spin_unlock_irq(&mq->lock);
 		return BLK_STS_RESOURCE;
 	}

 	switch (issue_type) {
 	case MMC_ISSUE_DCMD:
 		if (mmc_cqe_dcmd_busy(mq)) {
 			mq->cqe_busy |= MMC_CQE_DCMD_BUSY;
 			spin_unlock_irq(&mq->lock);
 			return BLK_STS_RESOURCE;
 		}
 		break;
 	case MMC_ISSUE_ASYNC:
 		if (host->hsq_enabled && mq->in_flight[issue_type] > host->hsq_depth) {
 			spin_unlock_irq(&mq->lock);
 			return BLK_STS_RESOURCE;
 		}
 		break;
 	default:
 		/*
 		 * Timeouts are handled by mmc core, and we don't have a host
 		 * API to abort requests, so we can't handle the timeout anyway.
 		 * However, when the timeout happens, blk_mq_complete_request()
 		 * no longer works (to stop the request disappearing under us).
 		 * To avoid racing with that, set a large timeout.
 		 */
 		req->timeout = 600 * HZ;
 		break;
 	}

 	/* Parallel dispatch of requests is not supported at the moment */
 	mq->busy = true;

 	mq->in_flight[issue_type] += 1;
 	get_card = (mmc_tot_in_flight(mq) == 1);
 	cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1);

 	spin_unlock_irq(&mq->lock);

 	if (!(req->rq_flags & RQF_DONTPREP)) {
 		req_to_mmc_queue_req(req)->retries = 0;
 		req->rq_flags |= RQF_DONTPREP;
 	}

 	if (get_card)
 		mmc_get_card(card, &mq->ctx);

 	if (host->cqe_enabled) {
 		host->retune_now = host->need_retune && cqe_retune_ok &&
 				   !host->hold_retune;
 	}

 	blk_mq_start_request(req);

 	issued = mmc_blk_mq_issue_rq(mq, req);

 	switch (issued) {
 	case MMC_REQ_BUSY:
 		ret = BLK_STS_RESOURCE;
 		break;
 	case MMC_REQ_FAILED_TO_START:
 		ret = BLK_STS_IOERR;
 		break;
 	default:
 		ret = BLK_STS_OK;
 		break;
 	}

 	if (issued != MMC_REQ_STARTED) {
 		bool put_card = false;

 		spin_lock_irq(&mq->lock);
 		mq->in_flight[issue_type] -= 1;
 		if (mmc_tot_in_flight(mq) == 0)
 			put_card = true;
 		mq->busy = false;
 		spin_unlock_irq(&mq->lock);
 		if (put_card)
 			mmc_put_card(card, &mq->ctx);
 	} else {
 		WRITE_ONCE(mq->busy, false);
 	}

 	return ret;
 }

 static const struct blk_mq_ops mmc_mq_ops = {
 	.queue_rq	= mmc_mq_queue_rq,
 	.init_request	= mmc_mq_init_request,
 	.exit_request	= mmc_mq_exit_request,
 	.complete	= mmc_blk_mq_complete,
 	.timeout	= mmc_mq_timed_out,
 };

 static struct gendisk *mmc_alloc_disk(struct mmc_queue *mq,
 		struct mmc_card *card, unsigned int features)
 {
 	struct mmc_host *host = card->host;
 	struct queue_limits lim = {
 		.features		= features,
 	};
 	struct gendisk *disk;

 	if (mmc_can_erase(card))
 		mmc_queue_setup_discard(card, &lim);

 	lim.max_hw_sectors = min(host->max_blk_count, host->max_req_size / 512);

 	if (mmc_card_mmc(card) && card->ext_csd.data_sector_size)
 		lim.logical_block_size = card->ext_csd.data_sector_size;
 	else
 		lim.logical_block_size = 512;

 	WARN_ON_ONCE(lim.logical_block_size != 512 &&
 		     lim.logical_block_size != 4096);

 	/*
 	 * Setting a virt_boundary implicity sets a max_segment_size, so try
 	 * to set the hardware one here.
 	 */
 	if (host->can_dma_map_merge) {
 		lim.virt_boundary_mask = dma_get_merge_boundary(mmc_dev(host));
 		lim.max_segments = MMC_DMA_MAP_MERGE_SEGMENTS;
 	} else {
 		lim.max_segment_size =
 			round_down(host->max_seg_size, lim.logical_block_size);
 		lim.max_segments = host->max_segs;
 	}

 	if (mmc_host_is_spi(host) && host->use_spi_crc)
 		lim.features |= BLK_FEAT_STABLE_WRITES;

 	disk = blk_mq_alloc_disk(&mq->tag_set, &lim, mq);
 	if (IS_ERR(disk))
 		return disk;
 	mq->queue = disk->queue;

 	blk_queue_rq_timeout(mq->queue, 60 * HZ);

 	if (mmc_dev(host)->dma_parms)
 		dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue));

 	INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
 	INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);

 	mutex_init(&mq->complete_lock);

 	init_waitqueue_head(&mq->wait);

 	mmc_crypto_setup_queue(mq->queue, host);
 	return disk;
 }

 static inline bool mmc_merge_capable(struct mmc_host *host)
 {
 	return host->caps2 & MMC_CAP2_MERGE_CAPABLE;
 }

 /* Set queue depth to get a reasonable value for q->nr_requests */
 #define MMC_QUEUE_DEPTH 64

 /**
  * mmc_init_queue - initialise a queue structure.
  * @mq: mmc queue
  * @card: mmc card to attach this queue
  * @features: block layer features (BLK_FEAT_*)
  *
  * Initialise a MMC card request queue.
  */
 struct gendisk *mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 		unsigned int features)
 {
 	struct mmc_host *host = card->host;
 	struct gendisk *disk;
 	int ret;

 	mq->card = card;

 	spin_lock_init(&mq->lock);

 	memset(&mq->tag_set, 0, sizeof(mq->tag_set));
 	mq->tag_set.ops = &mmc_mq_ops;
 	/*
 	 * The queue depth for CQE must match the hardware because the request
 	 * tag is used to index the hardware queue.
 	 */
 	if (host->cqe_enabled && !host->hsq_enabled)
 		mq->tag_set.queue_depth =
 			min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
 	else
 		mq->tag_set.queue_depth = MMC_QUEUE_DEPTH;
 	mq->tag_set.numa_node = NUMA_NO_NODE;
 	mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING;
 	mq->tag_set.nr_hw_queues = 1;
 	mq->tag_set.cmd_size = sizeof(struct mmc_queue_req);
 	mq->tag_set.driver_data = mq;

 	/*
 	 * Since blk_mq_alloc_tag_set() calls .init_request() of mmc_mq_ops,
 	 * the host->can_dma_map_merge should be set before to get max_segs
 	 * from mmc_get_max_segments().
 	 */
 	if (mmc_merge_capable(host) &&
 	    host->max_segs < MMC_DMA_MAP_MERGE_SEGMENTS &&
 	    dma_get_merge_boundary(mmc_dev(host)))
 		host->can_dma_map_merge = 1;
 	else
 		host->can_dma_map_merge = 0;

 	ret = blk_mq_alloc_tag_set(&mq->tag_set);
 	if (ret)
 		return ERR_PTR(ret);


 	disk = mmc_alloc_disk(mq, card, features);
 	if (IS_ERR(disk))
 		blk_mq_free_tag_set(&mq->tag_set);
 	return disk;
 }

 void mmc_queue_suspend(struct mmc_queue *mq)
 {
 	blk_mq_quiesce_queue(mq->queue);

 	/*
 	 * The host remains claimed while there are outstanding requests, so
 	 * simply claiming and releasing here ensures there are none.
 	 */
 	mmc_claim_host(mq->card->host);
 	mmc_release_host(mq->card->host);
 }

 void mmc_queue_resume(struct mmc_queue *mq)
 {
 	blk_mq_unquiesce_queue(mq->queue);
 }

 void mmc_cleanup_queue(struct mmc_queue *mq)
 {
 	struct request_queue *q = mq->queue;

 	/*
 	 * The legacy code handled the possibility of being suspended,
 	 * so do that here too.
 	 */
 	if (blk_queue_quiesced(q))
 		blk_mq_unquiesce_queue(q);

 	/*
 	 * If the recovery completes the last (and only remaining) request in
 	 * the queue, and the card has been removed, we could end up here with
 	 * the recovery not quite finished yet, so cancel it.
 	 */
 	cancel_work_sync(&mq->recovery_work);

 	blk_mq_free_tag_set(&mq->tag_set);

 	/*
 	 * A request can be completed before the next request, potentially
 	 * leaving a complete_work with nothing to do. Such a work item might
 	 * still be queued at this point. Flush it.
 	 */
 	flush_work(&mq->complete_work);

 	mq->card = NULL;
 }

 /*
  * 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)
 {
 	struct request *req = mmc_queue_req_to_req(mqrq);

 	return blk_rq_map_sg(mq->queue, req, mqrq->sg);
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2003 Russell King, All Rights Reserved.
	* Copyright 2006-2007 Pierre Ossman
	*/
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/blkdev.h>
	#include <linux/freezer.h>
	#include <linux/scatterlist.h>
	#include <linux/dma-mapping.h>
	#include <linux/backing-dev.h>

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

	#include "queue.h"
	#include "block.h"
	#include "core.h"
	#include "card.h"
	#include "crypto.h"
	#include "host.h"

	#define MMC_DMA_MAP_MERGE_SEGMENTS 512

	static inline bool mmc_cqe_dcmd_busy(struct mmc_queue *mq)
	{
	/* Allow only 1 DCMD at a time */
	return mq->in_flight[MMC_ISSUE_DCMD];
	}

	void mmc_cqe_check_busy(struct mmc_queue *mq)
	{
	if ((mq->cqe_busy & MMC_CQE_DCMD_BUSY) && !mmc_cqe_dcmd_busy(mq))
	mq->cqe_busy &= ~MMC_CQE_DCMD_BUSY;
	}

	static inline bool mmc_cqe_can_dcmd(struct mmc_host *host)
	{
	return host->caps2 & MMC_CAP2_CQE_DCMD;
	}

	static enum mmc_issue_type mmc_cqe_issue_type(struct mmc_host *host,
	struct request *req)
	{
	switch (req_op(req)) {
	case REQ_OP_DRV_IN:
	case REQ_OP_DRV_OUT:
	case REQ_OP_DISCARD:
	case REQ_OP_SECURE_ERASE:
	case REQ_OP_WRITE_ZEROES:
	return MMC_ISSUE_SYNC;
	case REQ_OP_FLUSH:
	return mmc_cqe_can_dcmd(host) ? MMC_ISSUE_DCMD : MMC_ISSUE_SYNC;
	default:
	return MMC_ISSUE_ASYNC;
	}
	}

	enum mmc_issue_type mmc_issue_type(struct mmc_queue mq, struct request req)
	{
	struct mmc_host *host = mq->card->host;

	if (host->cqe_enabled && !host->hsq_enabled)
	return mmc_cqe_issue_type(host, req);

	if (req_op(req) == REQ_OP_READ \|\| req_op(req) == REQ_OP_WRITE)
	return MMC_ISSUE_ASYNC;

	return MMC_ISSUE_SYNC;
	}

	static void __mmc_cqe_recovery_notifier(struct mmc_queue *mq)
	{
	if (!mq->recovery_needed) {
	mq->recovery_needed = true;
	schedule_work(&mq->recovery_work);
	}
	}

	void mmc_cqe_recovery_notifier(struct mmc_request *mrq)
	{
	struct mmc_queue_req *mqrq = container_of(mrq, struct mmc_queue_req,
	brq.mrq);
	struct request *req = mmc_queue_req_to_req(mqrq);
	struct request_queue *q = req->q;
	struct mmc_queue *mq = q->queuedata;
	unsigned long flags;

	spin_lock_irqsave(&mq->lock, flags);
	__mmc_cqe_recovery_notifier(mq);
	spin_unlock_irqrestore(&mq->lock, flags);
	}

	static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
	{
	struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
	struct mmc_request *mrq = &mqrq->brq.mrq;
	struct mmc_queue *mq = req->q->queuedata;
	struct mmc_host *host = mq->card->host;
	enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
	bool recovery_needed = false;

	switch (issue_type) {
	case MMC_ISSUE_ASYNC:
	case MMC_ISSUE_DCMD:
	if (host->cqe_ops->cqe_timeout(host, mrq, &recovery_needed)) {
	if (recovery_needed)
	mmc_cqe_recovery_notifier(mrq);
	return BLK_EH_RESET_TIMER;
	}
	/* The request has gone already */
	return BLK_EH_DONE;
	default:
	/* Timeout is handled by mmc core */
	return BLK_EH_RESET_TIMER;
	}
	}

	static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req)
	{
	struct request_queue *q = req->q;
	struct mmc_queue *mq = q->queuedata;
	struct mmc_card *card = mq->card;
	struct mmc_host *host = card->host;
	unsigned long flags;
	bool ignore_tout;

	spin_lock_irqsave(&mq->lock, flags);
	ignore_tout = mq->recovery_needed \|\| !host->cqe_enabled \|\| host->hsq_enabled;
	spin_unlock_irqrestore(&mq->lock, flags);

	return ignore_tout ? BLK_EH_RESET_TIMER : mmc_cqe_timed_out(req);
	}

	static void mmc_mq_recovery_handler(struct work_struct *work)
	{
	struct mmc_queue *mq = container_of(work, struct mmc_queue,
	recovery_work);
	struct request_queue *q = mq->queue;
	struct mmc_host *host = mq->card->host;

	mmc_get_card(mq->card, &mq->ctx);

	mq->in_recovery = true;

	if (host->cqe_enabled && !host->hsq_enabled)
	mmc_blk_cqe_recovery(mq);
	else
	mmc_blk_mq_recovery(mq);

	mq->in_recovery = false;

	spin_lock_irq(&mq->lock);
	mq->recovery_needed = false;
	spin_unlock_irq(&mq->lock);

	if (host->hsq_enabled)
	host->cqe_ops->cqe_recovery_finish(host);

	mmc_put_card(mq->card, &mq->ctx);

	blk_mq_run_hw_queues(q, true);
	}

	static struct scatterlist *mmc_alloc_sg(unsigned short sg_len, gfp_t gfp)
	{
	struct scatterlist *sg;

	sg = kmalloc_array(sg_len, sizeof(*sg), gfp);
	if (sg)
	sg_init_table(sg, sg_len);

	return sg;
	}

	static void mmc_queue_setup_discard(struct mmc_card *card,
	struct queue_limits *lim)
	{
	unsigned max_discard;

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

	lim->max_hw_discard_sectors = max_discard;
	if (mmc_can_secure_erase_trim(card))
	lim->max_secure_erase_sectors = max_discard;
	if (mmc_can_trim(card) && card->erased_byte == 0)
	lim->max_write_zeroes_sectors = max_discard;

	/* granularity must not be greater than max. discard */
	if (card->pref_erase > max_discard)
	lim->discard_granularity = SECTOR_SIZE;
	else
	lim->discard_granularity = card->pref_erase << 9;
	}

	static unsigned short mmc_get_max_segments(struct mmc_host *host)
	{
	return host->can_dma_map_merge ? MMC_DMA_MAP_MERGE_SEGMENTS :
	host->max_segs;
	}

	static int mmc_mq_init_request(struct blk_mq_tag_set set, struct request req,
	unsigned int hctx_idx, unsigned int numa_node)
	{
	struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
	struct mmc_queue *mq = set->driver_data;
	struct mmc_card *card = mq->card;
	struct mmc_host *host = card->host;

	mq_rq->sg = mmc_alloc_sg(mmc_get_max_segments(host), GFP_KERNEL);
	if (!mq_rq->sg)
	return -ENOMEM;

	return 0;
	}

	static void mmc_mq_exit_request(struct blk_mq_tag_set set, struct request req,
	unsigned int hctx_idx)
	{
	struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);

	kfree(mq_rq->sg);
	mq_rq->sg = NULL;
	}

	static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
	const struct blk_mq_queue_data *bd)
	{
	struct request *req = bd->rq;
	struct request_queue *q = req->q;
	struct mmc_queue *mq = q->queuedata;
	struct mmc_card *card = mq->card;
	struct mmc_host *host = card->host;
	enum mmc_issue_type issue_type;
	enum mmc_issued issued;
	bool get_card, cqe_retune_ok;
	blk_status_t ret;

	if (mmc_card_removed(mq->card)) {
	req->rq_flags \|= RQF_QUIET;
	return BLK_STS_IOERR;
	}

	issue_type = mmc_issue_type(mq, req);

	spin_lock_irq(&mq->lock);

	if (mq->recovery_needed \|\| mq->busy) {
	spin_unlock_irq(&mq->lock);
	return BLK_STS_RESOURCE;
	}

	switch (issue_type) {
	case MMC_ISSUE_DCMD:
	if (mmc_cqe_dcmd_busy(mq)) {
	mq->cqe_busy \|= MMC_CQE_DCMD_BUSY;
	spin_unlock_irq(&mq->lock);
	return BLK_STS_RESOURCE;
	}
	break;
	case MMC_ISSUE_ASYNC:
	if (host->hsq_enabled && mq->in_flight[issue_type] > host->hsq_depth) {
	spin_unlock_irq(&mq->lock);
	return BLK_STS_RESOURCE;
	}
	break;
	default:
	/*
	* Timeouts are handled by mmc core, and we don't have a host
	* API to abort requests, so we can't handle the timeout anyway.
	* However, when the timeout happens, blk_mq_complete_request()
	* no longer works (to stop the request disappearing under us).
	* To avoid racing with that, set a large timeout.
	*/
	req->timeout = 600 * HZ;
	break;
	}

	/* Parallel dispatch of requests is not supported at the moment */
	mq->busy = true;

	mq->in_flight[issue_type] += 1;
	get_card = (mmc_tot_in_flight(mq) == 1);
	cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1);

	spin_unlock_irq(&mq->lock);

	if (!(req->rq_flags & RQF_DONTPREP)) {
	req_to_mmc_queue_req(req)->retries = 0;
	req->rq_flags \|= RQF_DONTPREP;
	}

	if (get_card)
	mmc_get_card(card, &mq->ctx);

	if (host->cqe_enabled) {
	host->retune_now = host->need_retune && cqe_retune_ok &&
	!host->hold_retune;
	}

	blk_mq_start_request(req);

	issued = mmc_blk_mq_issue_rq(mq, req);

	switch (issued) {
	case MMC_REQ_BUSY:
	ret = BLK_STS_RESOURCE;
	break;
	case MMC_REQ_FAILED_TO_START:
	ret = BLK_STS_IOERR;
	break;
	default:
	ret = BLK_STS_OK;
	break;
	}

	if (issued != MMC_REQ_STARTED) {
	bool put_card = false;

	spin_lock_irq(&mq->lock);
	mq->in_flight[issue_type] -= 1;
	if (mmc_tot_in_flight(mq) == 0)
	put_card = true;
	mq->busy = false;
	spin_unlock_irq(&mq->lock);
	if (put_card)
	mmc_put_card(card, &mq->ctx);
	} else {
	WRITE_ONCE(mq->busy, false);
	}

	return ret;
	}

	static const struct blk_mq_ops mmc_mq_ops = {
	.queue_rq = mmc_mq_queue_rq,
	.init_request = mmc_mq_init_request,
	.exit_request = mmc_mq_exit_request,
	.complete = mmc_blk_mq_complete,
	.timeout = mmc_mq_timed_out,
	};

	static struct gendisk mmc_alloc_disk(struct mmc_queue mq,
	struct mmc_card *card, unsigned int features)
	{
	struct mmc_host *host = card->host;
	struct queue_limits lim = {
	.features = features,
	};
	struct gendisk *disk;

	if (mmc_can_erase(card))
	mmc_queue_setup_discard(card, &lim);

	lim.max_hw_sectors = min(host->max_blk_count, host->max_req_size / 512);

	if (mmc_card_mmc(card) && card->ext_csd.data_sector_size)
	lim.logical_block_size = card->ext_csd.data_sector_size;
	else
	lim.logical_block_size = 512;

	WARN_ON_ONCE(lim.logical_block_size != 512 &&
	lim.logical_block_size != 4096);

	/*
	* Setting a virt_boundary implicity sets a max_segment_size, so try
	* to set the hardware one here.
	*/
	if (host->can_dma_map_merge) {
	lim.virt_boundary_mask = dma_get_merge_boundary(mmc_dev(host));
	lim.max_segments = MMC_DMA_MAP_MERGE_SEGMENTS;
	} else {
	lim.max_segment_size =
	round_down(host->max_seg_size, lim.logical_block_size);
	lim.max_segments = host->max_segs;
	}

	if (mmc_host_is_spi(host) && host->use_spi_crc)
	lim.features \|= BLK_FEAT_STABLE_WRITES;

	disk = blk_mq_alloc_disk(&mq->tag_set, &lim, mq);
	if (IS_ERR(disk))
	return disk;
	mq->queue = disk->queue;

	blk_queue_rq_timeout(mq->queue, 60 * HZ);

	if (mmc_dev(host)->dma_parms)
	dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue));

	INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
	INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);

	mutex_init(&mq->complete_lock);

	init_waitqueue_head(&mq->wait);

	mmc_crypto_setup_queue(mq->queue, host);
	return disk;
	}

	static inline bool mmc_merge_capable(struct mmc_host *host)
	{
	return host->caps2 & MMC_CAP2_MERGE_CAPABLE;
	}

	/* Set queue depth to get a reasonable value for q->nr_requests */
	#define MMC_QUEUE_DEPTH 64

	/**
	* mmc_init_queue - initialise a queue structure.
	* @mq: mmc queue
	* @card: mmc card to attach this queue
	* @features: block layer features (BLK_FEAT_*)
	*
	* Initialise a MMC card request queue.
	*/
	struct gendisk mmc_init_queue(struct mmc_queue mq, struct mmc_card *card,
	unsigned int features)
	{
	struct mmc_host *host = card->host;
	struct gendisk *disk;
	int ret;

	mq->card = card;

	spin_lock_init(&mq->lock);

	memset(&mq->tag_set, 0, sizeof(mq->tag_set));
	mq->tag_set.ops = &mmc_mq_ops;
	/*
	* The queue depth for CQE must match the hardware because the request
	* tag is used to index the hardware queue.
	*/
	if (host->cqe_enabled && !host->hsq_enabled)
	mq->tag_set.queue_depth =
	min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
	else
	mq->tag_set.queue_depth = MMC_QUEUE_DEPTH;
	mq->tag_set.numa_node = NUMA_NO_NODE;
	mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE \| BLK_MQ_F_BLOCKING;
	mq->tag_set.nr_hw_queues = 1;
	mq->tag_set.cmd_size = sizeof(struct mmc_queue_req);
	mq->tag_set.driver_data = mq;

	/*
	* Since blk_mq_alloc_tag_set() calls .init_request() of mmc_mq_ops,
	* the host->can_dma_map_merge should be set before to get max_segs
	* from mmc_get_max_segments().
	*/
	if (mmc_merge_capable(host) &&
	host->max_segs < MMC_DMA_MAP_MERGE_SEGMENTS &&
	dma_get_merge_boundary(mmc_dev(host)))
	host->can_dma_map_merge = 1;
	else
	host->can_dma_map_merge = 0;

	ret = blk_mq_alloc_tag_set(&mq->tag_set);
	if (ret)
	return ERR_PTR(ret);


	disk = mmc_alloc_disk(mq, card, features);
	if (IS_ERR(disk))
	blk_mq_free_tag_set(&mq->tag_set);
	return disk;
	}

	void mmc_queue_suspend(struct mmc_queue *mq)
	{
	blk_mq_quiesce_queue(mq->queue);

	/*
	* The host remains claimed while there are outstanding requests, so
	* simply claiming and releasing here ensures there are none.
	*/
	mmc_claim_host(mq->card->host);
	mmc_release_host(mq->card->host);
	}

	void mmc_queue_resume(struct mmc_queue *mq)
	{
	blk_mq_unquiesce_queue(mq->queue);
	}

	void mmc_cleanup_queue(struct mmc_queue *mq)
	{
	struct request_queue *q = mq->queue;

	/*
	* The legacy code handled the possibility of being suspended,
	* so do that here too.
	*/
	if (blk_queue_quiesced(q))
	blk_mq_unquiesce_queue(q);

	/*
	* If the recovery completes the last (and only remaining) request in
	* the queue, and the card has been removed, we could end up here with
	* the recovery not quite finished yet, so cancel it.
	*/
	cancel_work_sync(&mq->recovery_work);

	blk_mq_free_tag_set(&mq->tag_set);

	/*
	* A request can be completed before the next request, potentially
	* leaving a complete_work with nothing to do. Such a work item might
	* still be queued at this point. Flush it.
	*/
	flush_work(&mq->complete_work);

	mq->card = NULL;
	}

	/*
	* 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)
	{
	struct request *req = mmc_queue_req_to_req(mqrq);

	return blk_rq_map_sg(mq->queue, req, mqrq->sg);
	}