1 files changed, 13 insertions, 11 deletions

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f8db70a..24ccda3 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -723,6 +723,13 @@ static void nvme_complete_rq(struct request *req)
 	blk_mq_end_request(req, error);
 }
 
+/* We read the CQE phase first to check if the rest of the entry is valid */
+static inline bool nvme_cqe_valid(struct nvme_queue *nvmeq, u16 head,
+		u16 phase)
+{
+	return (le16_to_cpu(nvmeq->cqes[head].status) & 1) == phase;
+}
+
 static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
 {
 	u16 head, phase;
@@ -730,13 +737,10 @@ static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
 	head = nvmeq->cq_head;
 	phase = nvmeq->cq_phase;
 
-	for (;;) {
+	while (nvme_cqe_valid(nvmeq, head, phase)) {
 		struct nvme_completion cqe = nvmeq->cqes[head];
-		u16 status = le16_to_cpu(cqe.status);
 		struct request *req;
 
-		if ((status & 1) != phase)
-			break;
 		if (++head == nvmeq->q_depth) {
 			head = 0;
 			phase = !phase;
@@ -767,7 +771,7 @@ static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
 		req = blk_mq_tag_to_rq(*nvmeq->tags, cqe.command_id);
 		if (req->cmd_type == REQ_TYPE_DRV_PRIV && req->special)
 			memcpy(req->special, &cqe, sizeof(cqe));
-		blk_mq_complete_request(req, status >> 1);
+		blk_mq_complete_request(req, le16_to_cpu(cqe.status) >> 1);
 
 	}
 
@@ -808,18 +812,16 @@ static irqreturn_t nvme_irq(int irq, void *data)
 static irqreturn_t nvme_irq_check(int irq, void *data)
 {
 	struct nvme_queue *nvmeq = data;
-	struct nvme_completion cqe = nvmeq->cqes[nvmeq->cq_head];
-	if ((le16_to_cpu(cqe.status) & 1) != nvmeq->cq_phase)
-		return IRQ_NONE;
-	return IRQ_WAKE_THREAD;
+	if (nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase))
+		return IRQ_WAKE_THREAD;
+	return IRQ_NONE;
 }
 
 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) {
+	if (nvme_cqe_valid(nvmeq, nvmeq->cq_head, nvmeq->cq_phase)) {
 		spin_lock_irq(&nvmeq->q_lock);
 		__nvme_process_cq(nvmeq, &tag);
 		spin_unlock_irq(&nvmeq->q_lock);