Merge tag 'block-5.7-2020-05-16' of git://git.kernel.dk/linux-block

Pull block fix from Jens Axboe:
 "Just a single NVMe pull in here, with a single fix for a missing DMA
  read memory barrier for completions"

* tag 'block-5.7-2020-05-16' of git://git.kernel.dk/linux-block:
  nvme-pci: dma read memory barrier for completions

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index e13c370de830473972250ab683eec8a82a03564e..3726dc780d15b1f3284f14eb16971d9ddf310ce6 100644 (file)
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -989,6 +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);
        }