[PATCH 14/16] nvme-rdma: Ensure dma support when using p2pdma

[Logan Gunthorpe]

Ensure the dma operations support p2pdma before using the RDMA
device for P2PDMA. This allows switching the RDMA driver from
pci_p2pdma_map_sg() to dma_map_sg_p2pdma().

Signed-off-by: Logan Gunthorpe <logang at deltatee.com>
---
 drivers/nvme/target/rdma.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 6c1f3ab7649c..3ec7e77e5416 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -414,7 +414,8 @@ static int nvmet_rdma_alloc_rsp(struct nvmet_rdma_device *ndev,
 	if (ib_dma_mapping_error(ndev->device, r->send_sge.addr))
 		goto out_free_rsp;
 
-	if (!ib_uses_virt_dma(ndev->device))
+	if (!ib_uses_virt_dma(ndev->device) &&
+	    dma_pci_p2pdma_supported(&ndev->device->dev))
 		r->req.p2p_client = &ndev->device->dev;
 	r->send_sge.length = sizeof(*r->req.cqe);
 	r->send_sge.lkey = ndev->pd->local_dma_lkey;
-- 
2.20.1