[PATCH] nvmet-rdma: Fix missing dma sync to nvme data structures

[Parav Pandit]

This patch performs dma sync operations on nvme_commmand,
inline page(s) and nvme_completion.

nvme_command and write cmd inline data is synced
(a) on receiving of the recv queue completion for cpu access.
(b) before posting recv wqe back to rdma adapter for device access.

nvme_completion is synced
(a) on receiving send completion for nvme_completion for cpu access.
(b) before posting send wqe to rdma adapter for device access.

Pushing this patch through linux-rdma git tree as its more relavant with
Bart's changes for dma_map_ops of[1].

[1] https://patchwork.kernel.org/patch/9514085/

Signed-off-by: Parav Pandit <parav at mellanox.com>
---
 drivers/nvme/target/rdma.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 8c3760a..c6468b3 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -438,6 +438,14 @@ static int nvmet_rdma_post_recv(struct nvmet_rdma_device *ndev,
 {
 	struct ib_recv_wr *bad_wr;
 
+	dma_sync_single_for_device(ndev->device->dma_device,
+			cmd->sge[0].addr, sizeof(*cmd->nvme_cmd),
+			DMA_FROM_DEVICE);
+
+	if (cmd->sge[1].addr)
+		dma_sync_single_for_device(ndev->device->dma_device,
+				cmd->sge[1].addr, NVMET_RDMA_INLINE_DATA_SIZE,
+				DMA_FROM_DEVICE);
 	if (ndev->srq)
 		return ib_post_srq_recv(ndev->srq, &cmd->wr, &bad_wr);
 	return ib_post_recv(cmd->queue->cm_id->qp, &cmd->wr, &bad_wr);
@@ -507,6 +515,10 @@ static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc)
 	struct nvmet_rdma_rsp *rsp =
 		container_of(wc->wr_cqe, struct nvmet_rdma_rsp, send_cqe);
 
+	dma_sync_single_for_cpu(rsp->queue->dev->device->dma_device,
+			rsp->send_sge.addr, sizeof(*rsp->req.rsp),
+			DMA_TO_DEVICE);
+
 	nvmet_rdma_release_rsp(rsp);
 
 	if (unlikely(wc->status != IB_WC_SUCCESS &&
@@ -538,6 +550,11 @@ static void nvmet_rdma_queue_response(struct nvmet_req *req)
 		first_wr = &rsp->send_wr;
 
 	nvmet_rdma_post_recv(rsp->queue->dev, rsp->cmd);
+
+	dma_sync_single_for_device(rsp->queue->dev->device->dma_device,
+			rsp->send_sge.addr, sizeof(*rsp->req.rsp),
+			DMA_TO_DEVICE);
+
 	if (ib_post_send(cm_id->qp, first_wr, &bad_wr)) {
 		pr_err("sending cmd response failed\n");
 		nvmet_rdma_release_rsp(rsp);
@@ -698,6 +715,16 @@ static void nvmet_rdma_handle_command(struct nvmet_rdma_queue *queue,
 	cmd->n_rdma = 0;
 	cmd->req.port = queue->port;
 
+	dma_sync_single_for_cpu(queue->dev->device->dma_device,
+			cmd->cmd->sge[0].addr, sizeof(*cmd->cmd->nvme_cmd),
+			DMA_FROM_DEVICE);
+
+	if (cmd->cmd->sge[1].addr)
+		dma_sync_single_for_cpu(queue->dev->device->dma_device,
+				cmd->cmd->sge[1].addr,
+				NVMET_RDMA_INLINE_DATA_SIZE,
+				DMA_FROM_DEVICE);
+
 	if (!nvmet_req_init(&cmd->req, &queue->nvme_cq,
 			&queue->nvme_sq, &nvmet_rdma_ops))
 		return;
-- 
1.8.3.1