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NVMe: add blk polling support

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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 <axboe@fb.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
This commit is contained in:
Jens Axboe 2015-11-03 20:37:26 -07:00
parent 05229beedd
commit a0fa9647a5
1 changed files with 28 additions and 4 deletions
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32
drivers/nvme/host/pci.c
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@ -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)