mmc: core: Use blk_mq_complete_request_direct().

The completion callback for the sdhci-pci device is invoked from a
kworker.
I couldn't identify in which context is mmc_blk_mq_req_done() invoke but
the remaining caller are from invoked from preemptible context. Here it
would make sense to complete the request directly instead scheduling
ksoftirqd for its completion.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20211025070658.1565848-3-bigeasy@linutronix.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/mmc/core/block.c

@@ -2051,7 +2051,8 @@ static void mmc_blk_mq_dec_in_flight(struct mmc_queue *mq, struct request *req)
 		mmc_put_card(mq->card, &mq->ctx);
 }
 
-static void mmc_blk_mq_post_req(struct mmc_queue *mq, struct request *req)
+static void mmc_blk_mq_post_req(struct mmc_queue *mq, struct request *req,
+				bool can_sleep)
 {
 	struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
 	struct mmc_request *mrq = &mqrq->brq.mrq;
@@ -2063,10 +2064,14 @@ static void mmc_blk_mq_post_req(struct mmc_queue *mq, struct request *req)
 	 * Block layer timeouts race with completions which means the normal
 	 * completion path cannot be used during recovery.
 	 */
-	if (mq->in_recovery)
+	if (mq->in_recovery) {
 		mmc_blk_mq_complete_rq(mq, req);
-	else if (likely(!blk_should_fake_timeout(req->q)))
-		blk_mq_complete_request(req);
+	} else if (likely(!blk_should_fake_timeout(req->q))) {
+		if (can_sleep)
+			blk_mq_complete_request_direct(req, mmc_blk_mq_complete);
+		else
+			blk_mq_complete_request(req);
+	}
 
 	mmc_blk_mq_dec_in_flight(mq, req);
 }
@@ -2087,7 +2092,7 @@ void mmc_blk_mq_recovery(struct mmc_queue *mq)
 
 	mmc_blk_urgent_bkops(mq, mqrq);
 
-	mmc_blk_mq_post_req(mq, req);
+	mmc_blk_mq_post_req(mq, req, true);
 }
 
 static void mmc_blk_mq_complete_prev_req(struct mmc_queue *mq,
@@ -2106,7 +2111,7 @@ static void mmc_blk_mq_complete_prev_req(struct mmc_queue *mq,
 	if (prev_req)
 		*prev_req = mq->complete_req;
 	else
-		mmc_blk_mq_post_req(mq, mq->complete_req);
+		mmc_blk_mq_post_req(mq, mq->complete_req, true);
 
 	mq->complete_req = NULL;
 
@@ -2178,7 +2183,8 @@ static void mmc_blk_mq_req_done(struct mmc_request *mrq)
 	mq->rw_wait = false;
 	wake_up(&mq->wait);
 
-	mmc_blk_mq_post_req(mq, req);
+	/* context unknown */
+	mmc_blk_mq_post_req(mq, req, false);
 }
 
 static bool mmc_blk_rw_wait_cond(struct mmc_queue *mq, int *err)
@@ -2238,7 +2244,7 @@ static int mmc_blk_mq_issue_rw_rq(struct mmc_queue *mq,
 	err = mmc_start_request(host, &mqrq->brq.mrq);
 
 	if (prev_req)
-		mmc_blk_mq_post_req(mq, prev_req);
+		mmc_blk_mq_post_req(mq, prev_req, true);
 
 	if (err)
 		mq->rw_wait = false;