Re: [PATCH 14/16] nvme-rdma: Ensure dma support when using p2pdma
From: John Hubbard <jhubbard@nvidia.com>
Date: 2021-05-03 01:37:30
Also in:
linux-iommu, linux-mm, linux-nvme, linux-pci, lkml
On 4/8/21 10:01 AM, Logan Gunthorpe wrote:
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().
Tentatively, this looks right, but it really should be combined with a following patch that uses it. Then you don't have to try to explain, above, why it's needed. :)
quoted hunk ↗ jump to hunk
Signed-off-by: Logan Gunthorpe <logang@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;
thanks, -- John Hubbard NVIDIA