From 920d13a884c0595451658a7b48af8ac16918628f Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Sun, 18 Jun 2017 17:28:09 +0300 Subject: [PATCH] nvme-pci: factor out the cqe reading mechanics from __nvme_process_cq Also, maintain a consumed counter to rely on for doorbell and cqe_seen update instead of directly relying on the cq head and phase. Signed-off-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch Signed-off-by: Jens Axboe --- drivers/nvme/host/pci.c | 48 ++++++++++++++++++++++------------------- 1 file changed, 26 insertions(+), 22 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 26eb1743f8bc..d309b6c90511 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -770,36 +770,40 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, nvme_end_request(req, cqe->status, cqe->result); } -static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag) +static inline bool nvme_read_cqe(struct nvme_queue *nvmeq, + struct nvme_completion *cqe) { - u16 head, phase; - - head = nvmeq->cq_head; - phase = nvmeq->cq_phase; - - while (nvme_cqe_valid(nvmeq, head, phase)) { - struct nvme_completion cqe = nvmeq->cqes[head]; + if (nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase)) { + *cqe = nvmeq->cqes[nvmeq->cq_head]; - if (++head == nvmeq->q_depth) { - head = 0; - phase = !phase; + if (++nvmeq->cq_head == nvmeq->q_depth) { + nvmeq->cq_head = 0; + nvmeq->cq_phase = !nvmeq->cq_phase; } - - if (tag && *tag == cqe.command_id) - *tag = -1; - - nvme_handle_cqe(nvmeq, &cqe); + return true; } + return false; +} - if (head == nvmeq->cq_head && phase == nvmeq->cq_phase) - return; +static void __nvme_process_cq(struct nvme_queue *nvmeq, int *tag) +{ + struct nvme_completion cqe; + int consumed = 0; - nvmeq->cq_head = head; - nvmeq->cq_phase = phase; + while (nvme_read_cqe(nvmeq, &cqe)) { + nvme_handle_cqe(nvmeq, &cqe); + consumed++; - nvme_ring_cq_doorbell(nvmeq); + if (tag && *tag == cqe.command_id) { + *tag = -1; + break; + } + } - nvmeq->cqe_seen = 1; + if (consumed) { + nvme_ring_cq_doorbell(nvmeq); + nvmeq->cqe_seen = 1; + } } static void nvme_process_cq(struct nvme_queue *nvmeq) -- 2.20.1