From: Keith Busch <kbusch@kernel.org>
Date: Mon, 2 Mar 2020 08:45:04 -0800
Subject: [PATCH] nvme-pci: Remove tag from process cq
Git-commit: bf392a5dc02a9b796f3da89fc5bb42856aca64cb
Patch-mainline: v5.7-rc1
References: git-fixes

The only user for tagged completion was for timeout handling. That user,
though, really only cares if the timed out command is completed, which
we can safely check within the timeout handler.

Remove the tag check to simplify completion handling.

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/nvme/host/pci.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index cdc9b6149d38..98d8ddd7aa0f 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -989,14 +989,13 @@ static inline void nvme_update_cq_head(struct nvme_queue *nvmeq)
 }
 
 static inline int nvme_process_cq(struct nvme_queue *nvmeq, u16 *start,
-				  u16 *end, unsigned int tag)
+				  u16 *end)
 {
 	int found = 0;
 
 	*start = nvmeq->cq_head;
 	while (nvme_cqe_pending(nvmeq)) {
-		if (tag == -1U || nvmeq->cqes[nvmeq->cq_head].command_id == tag)
-			found++;
+		found++;
 		nvme_update_cq_head(nvmeq);
 	}
 	*end = nvmeq->cq_head;
@@ -1017,7 +1016,7 @@ static irqreturn_t nvme_irq(int irq, void *data)
 	 * the irq handler, even if that was on another CPU.
 	 */
 	rmb();
-	nvme_process_cq(nvmeq, &start, &end, -1);
+	nvme_process_cq(nvmeq, &start, &end);
 	wmb();
 
 	if (start != end) {
@@ -1040,7 +1039,7 @@ static irqreturn_t nvme_irq_check(int irq, void *data)
  * Poll for completions any queue, including those not dedicated to polling.
  * Can be called from any context.
  */
-static int nvme_poll_irqdisable(struct nvme_queue *nvmeq, unsigned int tag)
+static int nvme_poll_irqdisable(struct nvme_queue *nvmeq)
 {
 	struct pci_dev *pdev = to_pci_dev(nvmeq->dev->dev);
 	u16 start, end;
@@ -1053,11 +1052,11 @@ static int nvme_poll_irqdisable(struct nvme_queue *nvmeq, unsigned int tag)
 	 */
 	if (test_bit(NVMEQ_POLLED, &nvmeq->flags)) {
 		spin_lock(&nvmeq->cq_poll_lock);
-		found = nvme_process_cq(nvmeq, &start, &end, tag);
+		found = nvme_process_cq(nvmeq, &start, &end);
 		spin_unlock(&nvmeq->cq_poll_lock);
 	} else {
 		disable_irq(pci_irq_vector(pdev, nvmeq->cq_vector));
-		found = nvme_process_cq(nvmeq, &start, &end, tag);
+		found = nvme_process_cq(nvmeq, &start, &end);
 		enable_irq(pci_irq_vector(pdev, nvmeq->cq_vector));
 	}
 
@@ -1075,8 +1074,7 @@ static int nvme_poll(struct blk_mq_hw_ctx *hctx)
 		return 0;
 
 	spin_lock(&nvmeq->cq_poll_lock);
-	found = nvme_process_cq(nvmeq, &start, &end, -1);
-	nvme_complete_cqes(nvmeq, start, end);
+	found = nvme_process_cq(nvmeq, &start, &end);
 	spin_unlock(&nvmeq->cq_poll_lock);
 
 	return found;
@@ -1253,7 +1251,8 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
 	/*
 	 * Did we miss an interrupt?
 	 */
-	if (nvme_poll_irqdisable(nvmeq, req->tag)) {
+	nvme_poll_irqdisable(nvmeq);
+	if (blk_mq_request_completed(req)) {
 		dev_warn(dev->ctrl.device,
 			 "I/O %d QID %d timeout, completion polled\n",
 			 req->tag, nvmeq->qid);
@@ -1396,7 +1395,7 @@ static void nvme_disable_admin_queue(struct nvme_dev *dev, bool shutdown)
 	else
 		nvme_disable_ctrl(&dev->ctrl);
 
-	nvme_poll_irqdisable(nvmeq, -1);
+	nvme_poll_irqdisable(nvmeq);
 }
 
 /*
@@ -1411,7 +1410,7 @@ static void nvme_reap_pending_cqes(struct nvme_dev *dev)
 	int i;
 
 	for (i = dev->ctrl.queue_count - 1; i > 0; i--) {
-		nvme_process_cq(&dev->queues[i], &start, &end, -1);
+		nvme_process_cq(&dev->queues[i], &start, &end);
 		nvme_complete_cqes(&dev->queues[i], start, end);
 	}
 }
-- 
2.29.2