diff options
Diffstat (limited to 'drivers/nvme/host/pci.c')
| -rw-r--r-- | drivers/nvme/host/pci.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 4e79e412b276..3726dc780d15 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -973,9 +973,13 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx) static inline void nvme_update_cq_head(struct nvme_queue *nvmeq) { - if (++nvmeq->cq_head == nvmeq->q_depth) { + u16 tmp = nvmeq->cq_head + 1; + + if (tmp == nvmeq->q_depth) { nvmeq->cq_head = 0; nvmeq->cq_phase ^= 1; + } else { + nvmeq->cq_head = tmp; } } @@ -985,6 +989,11 @@ static inline int nvme_process_cq(struct nvme_queue *nvmeq) while (nvme_cqe_pending(nvmeq)) { found++; + /* + * load-load control dependency between phase and the rest of + * the cqe requires a full read memory barrier + */ + dma_rmb(); nvme_handle_cqe(nvmeq, nvmeq->cq_head); nvme_update_cq_head(nvmeq); } |