Merge tag 'v5.7-rc7' into efi/core, to refresh the branch and pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

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);
 	}