From a0fa9647a54e81883abd57c5c865d1747f68a577 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 3 Nov 2015 20:37:26 -0700 Subject: [PATCH] NVMe: add blk polling support Add nvme_poll(), which will check a specific completion queue for command completions. Wire that up to the new block layer poll mechanism. Signed-off-by: Jens Axboe Signed-off-by: Christoph Hellwig Acked-by: Keith Busch --- drivers/nvme/host/pci.c | 32 ++++++++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index e878590e71b6..4a715f49f5db 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -90,7 +90,7 @@ static struct class *nvme_class; static int __nvme_reset(struct nvme_dev *dev); static int nvme_reset(struct nvme_dev *dev); -static int nvme_process_cq(struct nvme_queue *nvmeq); +static void nvme_process_cq(struct nvme_queue *nvmeq); static void nvme_dead_ctrl(struct nvme_dev *dev); struct async_cmd_info { @@ -935,7 +935,7 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx, return BLK_MQ_RQ_QUEUE_BUSY; } -static int nvme_process_cq(struct nvme_queue *nvmeq) +static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag) { u16 head, phase; @@ -953,6 +953,8 @@ static int nvme_process_cq(struct nvme_queue *nvmeq) head = 0; phase = !phase; } + if (tag && *tag == cqe.command_id) + *tag = -1; ctx = nvme_finish_cmd(nvmeq, cqe.command_id, &fn); fn(nvmeq, ctx, &cqe); } @@ -964,14 +966,18 @@ static int nvme_process_cq(struct nvme_queue *nvmeq) * a big problem. */ if (head == nvmeq->cq_head && phase == nvmeq->cq_phase) - return 0; + return; writel(head, nvmeq->q_db + nvmeq->dev->db_stride); nvmeq->cq_head = head; nvmeq->cq_phase = phase; nvmeq->cqe_seen = 1; - return 1; +} + +static void nvme_process_cq(struct nvme_queue *nvmeq) +{ + __nvme_process_cq(nvmeq, NULL); } static irqreturn_t nvme_irq(int irq, void *data) @@ -995,6 +1001,23 @@ static irqreturn_t nvme_irq_check(int irq, void *data) return IRQ_WAKE_THREAD; } +static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag) +{ + struct nvme_queue *nvmeq = hctx->driver_data; + + if ((le16_to_cpu(nvmeq->cqes[nvmeq->cq_head].status) & 1) == + nvmeq->cq_phase) { + spin_lock_irq(&nvmeq->q_lock); + __nvme_process_cq(nvmeq, &tag); + spin_unlock_irq(&nvmeq->q_lock); + + if (tag == -1) + return 1; + } + + return 0; +} + /* * Returns 0 on success. If the result is negative, it's a Linux error code; * if the result is positive, it's an NVM Express status code @@ -1654,6 +1677,7 @@ static struct blk_mq_ops nvme_mq_ops = { .init_hctx = nvme_init_hctx, .init_request = nvme_init_request, .timeout = nvme_timeout, + .poll = nvme_poll, }; static void nvme_dev_remove_admin(struct nvme_dev *dev) -- 2.20.1