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

 /*
  *  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/dma-mapping.h>

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

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

 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;

 	mq->cqe_busy &= ~MMC_CQE_QUEUE_FULL;
 }

 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:
 		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 (mq->use_cqe)
 		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(q->queue_lock, flags);
 	__mmc_cqe_recovery_notifier(mq);
 	spin_unlock_irqrestore(q->queue_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(mq);
 			return BLK_EH_RESET_TIMER;
 		}
 		/* No timeout (XXX: huh? comment doesn't make much sense) */
 		blk_mq_complete_request(req);
 		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,
 						 bool reserved)
 {
 	struct request_queue *q = req->q;
 	struct mmc_queue *mq = q->queuedata;
 	unsigned long flags;
 	int ret;

 	spin_lock_irqsave(q->queue_lock, flags);

 	if (mq->recovery_needed || !mq->use_cqe)
 		ret = BLK_EH_RESET_TIMER;
 	else
 		ret = mmc_cqe_timed_out(req);

 	spin_unlock_irqrestore(q->queue_lock, flags);

 	return ret;
 }

 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;

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

 	mq->in_recovery = true;

 	if (mq->use_cqe)
 		mmc_blk_cqe_recovery(mq);
 	else
 		mmc_blk_mq_recovery(mq);

 	mq->in_recovery = false;

 	spin_lock_irq(q->queue_lock);
 	mq->recovery_needed = false;
 	spin_unlock_irq(q->queue_lock);

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

 	blk_mq_run_hw_queues(q, true);
 }

 static struct scatterlist *mmc_alloc_sg(int 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 request_queue *q,
 				    struct mmc_card *card)
 {
 	unsigned max_discard;

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

 	blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
 	blk_queue_max_discard_sectors(q, max_discard);
 	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))
 		blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
 }

 /**
  * mmc_init_request() - initialize the MMC-specific per-request data
  * @q: the request queue
  * @req: the request
  * @gfp: memory allocation policy
  */
 static int __mmc_init_request(struct mmc_queue *mq, struct request *req,
 			      gfp_t gfp)
 {
 	struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
 	struct mmc_card *card = mq->card;
 	struct mmc_host *host = card->host;

 	mq_rq->sg = mmc_alloc_sg(host->max_segs, gfp);
 	if (!mq_rq->sg)
 		return -ENOMEM;

 	return 0;
 }

 static void mmc_exit_request(struct request_queue *q, struct request *req)
 {
 	struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);

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

 static int mmc_mq_init_request(struct blk_mq_tag_set *set, struct request *req,
 			       unsigned int hctx_idx, unsigned int numa_node)
 {
 	return __mmc_init_request(set->driver_data, req, GFP_KERNEL);
 }

 static void mmc_mq_exit_request(struct blk_mq_tag_set *set, struct request *req,
 				unsigned int hctx_idx)
 {
 	struct mmc_queue *mq = set->driver_data;

 	mmc_exit_request(mq->queue, req);
 }

 /*
  * We use BLK_MQ_F_BLOCKING and have only 1 hardware queue, which means requests
  * will not be dispatched in parallel.
  */
 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;
 	int 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(q->queue_lock);

 	if (mq->recovery_needed) {
 		spin_unlock_irq(q->queue_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(q->queue_lock);
 			return BLK_STS_RESOURCE;
 		}
 		break;
 	case MMC_ISSUE_ASYNC:
 		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;
 	}

 	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(q->queue_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 (mq->use_cqe) {
 		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(q->queue_lock);
 		mq->in_flight[issue_type] -= 1;
 		if (mmc_tot_in_flight(mq) == 0)
 			put_card = true;
 		spin_unlock_irq(q->queue_lock);
 		if (put_card)
 			mmc_put_card(card, &mq->ctx);
 	}

 	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 void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
 {
 	struct mmc_host *host = card->host;
 	u64 limit = BLK_BOUNCE_HIGH;

 	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
 		limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;

 	blk_queue_flag_set(QUEUE_FLAG_NONROT, mq->queue);
 	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue);
 	if (mmc_can_erase(card))
 		mmc_queue_setup_discard(mq->queue, card);

 	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);

 	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);
 }

 static int mmc_mq_init_queue(struct mmc_queue *mq, int q_depth,
 			     const struct blk_mq_ops *mq_ops, spinlock_t *lock)
 {
 	int ret;

 	memset(&mq->tag_set, 0, sizeof(mq->tag_set));
 	mq->tag_set.ops = mq_ops;
 	mq->tag_set.queue_depth = q_depth;
 	mq->tag_set.numa_node = NUMA_NO_NODE;
 	mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_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;

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

 	mq->queue = blk_mq_init_queue(&mq->tag_set);
 	if (IS_ERR(mq->queue)) {
 		ret = PTR_ERR(mq->queue);
 		goto free_tag_set;
 	}

 	mq->queue->queue_lock = lock;
 	mq->queue->queuedata = mq;

 	return 0;

 free_tag_set:
 	blk_mq_free_tag_set(&mq->tag_set);

 	return ret;
 }

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

 static int mmc_mq_init(struct mmc_queue *mq, struct mmc_card *card,
 			 spinlock_t *lock)
 {
 	struct mmc_host *host = card->host;
 	int q_depth;
 	int ret;

 	/*
 	 * The queue depth for CQE must match the hardware because the request
 	 * tag is used to index the hardware queue.
 	 */
 	if (mq->use_cqe)
 		q_depth = min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
 	else
 		q_depth = MMC_QUEUE_DEPTH;

 	ret = mmc_mq_init_queue(mq, q_depth, &mmc_mq_ops, lock);
 	if (ret)
 		return ret;

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

 	mmc_setup_queue(mq, card);

 	return 0;
 }

 /**
  * 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;

 	mq->card = card;

 	mq->use_cqe = host->cqe_enabled;

 	return mmc_mq_init(mq, card, lock);
 }

 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);

 	blk_cleanup_queue(q);

 	/*
 	 * 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);
 }
	/*
	* 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/dma-mapping.h>

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

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

	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;

	mq->cqe_busy &= ~MMC_CQE_QUEUE_FULL;
	}

	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:
	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 (mq->use_cqe)
	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(q->queue_lock, flags);
	__mmc_cqe_recovery_notifier(mq);
	spin_unlock_irqrestore(q->queue_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(mq);
	return BLK_EH_RESET_TIMER;
	}
	/* No timeout (XXX: huh? comment doesn't make much sense) */
	blk_mq_complete_request(req);
	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,
	bool reserved)
	{
	struct request_queue *q = req->q;
	struct mmc_queue *mq = q->queuedata;
	unsigned long flags;
	int ret;

	spin_lock_irqsave(q->queue_lock, flags);

	if (mq->recovery_needed \|\| !mq->use_cqe)
	ret = BLK_EH_RESET_TIMER;
	else
	ret = mmc_cqe_timed_out(req);

	spin_unlock_irqrestore(q->queue_lock, flags);

	return ret;
	}

	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;

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

	mq->in_recovery = true;

	if (mq->use_cqe)
	mmc_blk_cqe_recovery(mq);
	else
	mmc_blk_mq_recovery(mq);

	mq->in_recovery = false;

	spin_lock_irq(q->queue_lock);
	mq->recovery_needed = false;
	spin_unlock_irq(q->queue_lock);

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

	blk_mq_run_hw_queues(q, true);
	}

	static struct scatterlist *mmc_alloc_sg(int 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 request_queue *q,
	struct mmc_card *card)
	{
	unsigned max_discard;

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

	blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
	blk_queue_max_discard_sectors(q, max_discard);
	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))
	blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
	}

	/**
	* mmc_init_request() - initialize the MMC-specific per-request data
	* @q: the request queue
	* @req: the request
	* @gfp: memory allocation policy
	*/
	static int __mmc_init_request(struct mmc_queue mq, struct request req,
	gfp_t gfp)
	{
	struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
	struct mmc_card *card = mq->card;
	struct mmc_host *host = card->host;

	mq_rq->sg = mmc_alloc_sg(host->max_segs, gfp);
	if (!mq_rq->sg)
	return -ENOMEM;

	return 0;
	}

	static void mmc_exit_request(struct request_queue q, struct request req)
	{
	struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);

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

	static int mmc_mq_init_request(struct blk_mq_tag_set set, struct request req,
	unsigned int hctx_idx, unsigned int numa_node)
	{
	return __mmc_init_request(set->driver_data, req, GFP_KERNEL);
	}

	static void mmc_mq_exit_request(struct blk_mq_tag_set set, struct request req,
	unsigned int hctx_idx)
	{
	struct mmc_queue *mq = set->driver_data;

	mmc_exit_request(mq->queue, req);
	}

	/*
	* We use BLK_MQ_F_BLOCKING and have only 1 hardware queue, which means requests
	* will not be dispatched in parallel.
	*/
	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;
	int 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(q->queue_lock);

	if (mq->recovery_needed) {
	spin_unlock_irq(q->queue_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(q->queue_lock);
	return BLK_STS_RESOURCE;
	}
	break;
	case MMC_ISSUE_ASYNC:
	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;
	}

	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(q->queue_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 (mq->use_cqe) {
	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(q->queue_lock);
	mq->in_flight[issue_type] -= 1;
	if (mmc_tot_in_flight(mq) == 0)
	put_card = true;
	spin_unlock_irq(q->queue_lock);
	if (put_card)
	mmc_put_card(card, &mq->ctx);
	}

	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 void mmc_setup_queue(struct mmc_queue mq, struct mmc_card card)
	{
	struct mmc_host *host = card->host;
	u64 limit = BLK_BOUNCE_HIGH;

	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
	limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;

	blk_queue_flag_set(QUEUE_FLAG_NONROT, mq->queue);
	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue);
	if (mmc_can_erase(card))
	mmc_queue_setup_discard(mq->queue, card);

	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);

	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);
	}

	static int mmc_mq_init_queue(struct mmc_queue *mq, int q_depth,
	const struct blk_mq_ops mq_ops, spinlock_t lock)
	{
	int ret;

	memset(&mq->tag_set, 0, sizeof(mq->tag_set));
	mq->tag_set.ops = mq_ops;
	mq->tag_set.queue_depth = q_depth;
	mq->tag_set.numa_node = NUMA_NO_NODE;
	mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE \| BLK_MQ_F_SG_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;

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

	mq->queue = blk_mq_init_queue(&mq->tag_set);
	if (IS_ERR(mq->queue)) {
	ret = PTR_ERR(mq->queue);
	goto free_tag_set;
	}

	mq->queue->queue_lock = lock;
	mq->queue->queuedata = mq;

	return 0;

	free_tag_set:
	blk_mq_free_tag_set(&mq->tag_set);

	return ret;
	}

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

	static int mmc_mq_init(struct mmc_queue mq, struct mmc_card card,
	spinlock_t *lock)
	{
	struct mmc_host *host = card->host;
	int q_depth;
	int ret;

	/*
	* The queue depth for CQE must match the hardware because the request
	* tag is used to index the hardware queue.
	*/
	if (mq->use_cqe)
	q_depth = min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
	else
	q_depth = MMC_QUEUE_DEPTH;

	ret = mmc_mq_init_queue(mq, q_depth, &mmc_mq_ops, lock);
	if (ret)
	return ret;

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

	mmc_setup_queue(mq, card);

	return 0;
	}

	/**
	* 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;

	mq->card = card;

	mq->use_cqe = host->cqe_enabled;

	return mmc_mq_init(mq, card, lock);
	}

	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);

	blk_cleanup_queue(q);

	/*
	* 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);
	}