Commit ee8a43a5 authored by Per Forlin's avatar Per Forlin Committed by Chris Ball
Browse files

mmc: block: add handling for two parallel block requests in issue_rw_rq 



Change mmc_blk_issue_rw_rq() to become asynchronous.
The execution flow looks like this:

* The mmc-queue calls issue_rw_rq(), which sends the request
  to the host and returns back to the mmc-queue.
* The mmc-queue calls issue_rw_rq() again with a new request.
* This new request is prepared in issue_rw_rq(), then it waits for
  the active request to complete before pushing it to the host.
* When the mmc-queue is empty it will call issue_rw_rq() with a NULL
  req to finish off the active request without starting a new request.

Signed-off-by: default avatarPer Forlin <per.forlin@linaro.org>
Acked-by: default avatarKyungmin Park <kyungmin.park@samsung.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Reviewed-by: default avatarVenkatraman S <svenkatr@ti.com>
Tested-by: default avatarSourav Poddar <sourav.poddar@ti.com>
Tested-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent 04296b7b

drivers/mmc/card/block.c

+71 −15
Original line number Diff line number Diff line
@@ -822,12 +822,14 @@ static inline void mmc_apply_rel_rw(struct mmc_blk_request *brq, 
	 R1_CC_ERROR |		/* Card controller error */		\

	 R1_ERROR)		/* General/unknown error */



int mmc_blk_err_check(struct mmc_blk_request *brq,

		      struct request *req,

		      struct mmc_card *card,

		      struct mmc_blk_data *md)

static int mmc_blk_err_check(struct mmc_card *card,

			     struct mmc_async_req *areq)

{

	int ret = MMC_BLK_SUCCESS;

	enum mmc_blk_status ret = MMC_BLK_SUCCESS;

	struct mmc_queue_req *mq_mrq = container_of(areq, struct mmc_queue_req,

						    mmc_active);

	struct mmc_blk_request *brq = &mq_mrq->brq;

	struct request *req = mq_mrq->req;



	/*

	 * sbc.error indicates a problem with the set block count
@@ -1038,24 +1040,41 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq, 
		brq->data.sg_len = i;

	}



	mqrq->mmc_active.mrq = &brq->mrq;

	mqrq->mmc_active.err_check = mmc_blk_err_check;



	mmc_queue_bounce_pre(mqrq);

}



static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)

static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)

{

	struct mmc_blk_data *md = mq->data;

	struct mmc_card *card = md->queue.card;

	struct mmc_blk_request *brq = &mq->mqrq_cur->brq;

	int ret = 1, disable_multi = 0, retry = 0;

	enum mmc_blk_status status;

	struct mmc_queue_req *mq_rq;

	struct request *req;

	struct mmc_async_req *areq;



	if (!rqc && !mq->mqrq_prev->req)

		return 0;



	do {

		mmc_blk_rw_rq_prep(mq->mqrq_cur, card, disable_multi, mq);

		mmc_wait_for_req(card->host, &brq->mrq);

		if (rqc) {

			mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);

			areq = &mq->mqrq_cur->mmc_active;

		} else

			areq = NULL;

		areq = mmc_start_req(card->host, areq, (int *) &status);

		if (!areq)

			return 0;



		mmc_queue_bounce_post(mq->mqrq_cur);

		mq_rq = container_of(areq, struct mmc_queue_req, mmc_active);

		brq = &mq_rq->brq;

		req = mq_rq->req;

		mmc_queue_bounce_post(mq_rq);



		status = mmc_blk_err_check(brq, req, card, md);

		switch (status) {

		case MMC_BLK_SUCCESS:

		case MMC_BLK_PARTIAL:
@@ -1066,6 +1085,19 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req) 
			ret = __blk_end_request(req, 0,

						brq->data.bytes_xfered);

			spin_unlock_irq(&md->lock);

			if (status == MMC_BLK_SUCCESS && ret) {

				/*

				 * The blk_end_request has returned non zero

				 * even though all data is transfered and no

				 * erros returned by host.

				 * If this happen it's a bug.

				 */

				printk(KERN_ERR "%s BUG rq_tot %d d_xfer %d\n",

				       __func__, blk_rq_bytes(req),

				       brq->data.bytes_xfered);

				rqc = NULL;

				goto cmd_abort;

			}

			break;

		case MMC_BLK_CMD_ERR:

			goto cmd_err;
@@ -1087,9 +1119,19 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req) 
			ret = __blk_end_request(req, -EIO,

						brq->data.blksz);

			spin_unlock_irq(&md->lock);

			if (!ret)

				goto start_new_req;

			break;

		}



		if (ret) {

			/*

			 * In case of a none complete request

			 * prepare it again and resend.

			 */

			mmc_blk_rw_rq_prep(mq_rq, card, disable_multi, mq);

			mmc_start_req(card->host, &mq_rq->mmc_active, NULL);

		}

	} while (ret);



	return 1;
@@ -1124,6 +1166,12 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req) 
		ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));

	spin_unlock_irq(&md->lock);



 start_new_req:

	if (rqc) {

		mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);

		mmc_start_req(card->host, &mq->mqrq_cur->mmc_active, NULL);

	}



	return 0;

}
@@ -1133,25 +1181,33 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) 
	struct mmc_blk_data *md = mq->data;

	struct mmc_card *card = md->queue.card;



	if (req && !mq->mqrq_prev->req)

		/* claim host only for the first request */

		mmc_claim_host(card->host);



	ret = mmc_blk_part_switch(card, md);

	if (ret) {

		ret = 0;

		goto out;

	}



	if (req->cmd_flags & REQ_DISCARD) {

	if (req && req->cmd_flags & REQ_DISCARD) {

		/* complete ongoing async transfer before issuing discard */

		if (card->host->areq)

			mmc_blk_issue_rw_rq(mq, NULL);

		if (req->cmd_flags & REQ_SECURE)

			ret = mmc_blk_issue_secdiscard_rq(mq, req);

		else

			ret = mmc_blk_issue_discard_rq(mq, req);

	} else if (req->cmd_flags & REQ_FLUSH) {

	} else if (req && req->cmd_flags & REQ_FLUSH) {

		ret = mmc_blk_issue_flush(mq, req);

	} else {

		ret = mmc_blk_issue_rw_rq(mq, req);

	}



out:

	if (!req)

		/* release host only when there are no more requests */

		mmc_release_host(card->host);

	return ret;

}

drivers/mmc/card/queue.c

+12 −5
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ static int mmc_queue_thread(void *d) 
	down(&mq->thread_sem);

	do {

		struct request *req = NULL;

		struct mmc_queue_req *tmp;



		spin_lock_irq(q->queue_lock);

		set_current_state(TASK_INTERRUPTIBLE);
@@ -59,7 +60,10 @@ static int mmc_queue_thread(void *d) 
		mq->mqrq_cur->req = req;

		spin_unlock_irq(q->queue_lock);



		if (!req) {

		if (req || mq->mqrq_prev->req) {

			set_current_state(TASK_RUNNING);

			mq->issue_fn(mq, req);

		} else {

			if (kthread_should_stop()) {

				set_current_state(TASK_RUNNING);

				break;
@@ -67,11 +71,14 @@ static int mmc_queue_thread(void *d) 
			up(&mq->thread_sem);

			schedule();

			down(&mq->thread_sem);

			continue;

		}

		set_current_state(TASK_RUNNING);



		mq->issue_fn(mq, req);

		/* Current request becomes previous request and vice versa. */

		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;

	} while (1);

	up(&mq->thread_sem);
@@ -97,7 +104,7 @@ static void mmc_request(struct request_queue *q) 
		return;

	}



	if (!mq->mqrq_cur->req)

	if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)

		wake_up_process(mq->thread);

}

drivers/mmc/card/queue.h

+1 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ struct mmc_queue_req { 
	char			*bounce_buf;

	struct scatterlist	*bounce_sg;

	unsigned int		bounce_sg_len;

	struct mmc_async_req	mmc_active;

};



struct mmc_queue {

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