[PATCH v2 20/22] RDMA/core: Introduce ib_dma_pci_p2p_dma_supported()
From: Logan Gunthorpe <logang@deltatee.com>
Date: 2021-05-13 22:32:37
Also in:
linux-iommu, linux-mm, linux-nvme, linux-pci, lkml
Subsystem:
infiniband subsystem, nvm express target driver, the rest · Maintainers:
Jason Gunthorpe, Leon Romanovsky, Christoph Hellwig, Sagi Grimberg, Chaitanya Kulkarni, Linus Torvalds
Introduce the helper function ib_dma_pci_p2p_dma_supported() to check if a given ib_device can be used in P2PDMA transfers. This ensures the ib_device is not using virt_dma and also that the underlying dma_device supports P2PDMA. Use the new helper in nvme-rdma to replace the existing check for ib_uses_virt_dma(). Adding the dma_pci_p2pdma_supported() check allows switching away from pci_p2pdma_[un]map_sg(). Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- drivers/nvme/target/rdma.c | 2 +- include/rdma/ib_verbs.h | 11 +++++++++++ 2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 6c1f3ab7649c..86f0bf4dc1ca 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c@@ -414,7 +414,7 @@ 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_dma_pci_p2p_dma_supported(ndev->device)) r->req.p2p_client = &ndev->device->dev; r->send_sge.length = sizeof(*r->req.cqe); r->send_sge.lkey = ndev->pd->local_dma_lkey;
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 7e2f3699b898..724e80a656f7 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h@@ -3943,6 +3943,17 @@ static inline bool ib_uses_virt_dma(struct ib_device *dev) return IS_ENABLED(CONFIG_INFINIBAND_VIRT_DMA) && !dev->dma_device; } +/* + * Check if a IB device's underlying DMA mapping supports P2PDMA transfers. + */ +static inline bool ib_dma_pci_p2p_dma_supported(struct ib_device *dev) +{ + if (ib_uses_virt_dma(dev)) + return false; + + return dma_pci_p2pdma_supported(dev->dma_device); +} + /** * ib_dma_mapping_error - check a DMA addr for error * @dev: The device for which the dma_addr was created
--
2.20.1