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 <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Sagi Grimberg 2017-06-18 17:28:09 +03:00 committed by Jens Axboe
parent 83a12fb77b
commit 920d13a884

View File

@ -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;
if (nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase)) {
*cqe = nvmeq->cqes[nvmeq->cq_head];
head = nvmeq->cq_head;
phase = nvmeq->cq_phase;
while (nvme_cqe_valid(nvmeq, head, phase)) {
struct nvme_completion cqe = nvmeq->cqes[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;
}
return true;
}
return false;
}
if (tag && *tag == cqe.command_id)
*tag = -1;
static void __nvme_process_cq(struct nvme_queue *nvmeq, int *tag)
{
struct nvme_completion cqe;
int consumed = 0;
while (nvme_read_cqe(nvmeq, &cqe)) {
nvme_handle_cqe(nvmeq, &cqe);
consumed++;
if (tag && *tag == cqe.command_id) {
*tag = -1;
break;
}
}
if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
return;
nvmeq->cq_head = head;
nvmeq->cq_phase = phase;
nvme_ring_cq_doorbell(nvmeq);
nvmeq->cqe_seen = 1;
if (consumed) {
nvme_ring_cq_doorbell(nvmeq);
nvmeq->cqe_seen = 1;
}
}
static void nvme_process_cq(struct nvme_queue *nvmeq)