[PATCH V3 1/2] nvme-pci: move sq/cq_poll lock initialization into nvme_init_queue

[Ming Lei <ming.lei@redhat.com>]

Prepare for adding new cq lock for improving IO performance in case
that device applies aggressive interrupt coalescing, and the new added
cq_lock can share space with cq_poll_lock becasue both are mutually
exclusive.

Move sq/cq_poll lock initialization into nvme_init_queue so that
we may initialize the added cq_lock correctly and lockdep warning
can be avoided.

This way is safe because no IO can be started until nvme_init_queue
is returned.

Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Long Li <longli@microsoft.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/nvme/host/pci.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 869f462e6b6e..01728409a7ea 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1481,8 +1481,6 @@ static int nvme_alloc_queue(struct nvme_dev *dev, int qid, int depth)
 		goto free_cqdma;
 
 	nvmeq->dev = dev;
-	spin_lock_init(&nvmeq->sq_lock);
-	spin_lock_init(&nvmeq->cq_poll_lock);
 	nvmeq->cq_head = 0;
 	nvmeq->cq_phase = 1;
 	nvmeq->q_db = &dev->dbs[qid * 2 * dev->db_stride];
@@ -1516,6 +1514,9 @@ static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
 {
 	struct nvme_dev *dev = nvmeq->dev;
 
+	spin_lock_init(&nvmeq->sq_lock);
+	spin_lock_init(&nvmeq->cq_poll_lock);
+
 	nvmeq->sq_tail = 0;
 	nvmeq->last_sq_tail = 0;
 	nvmeq->cq_head = 0;
-- 
2.20.1


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