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authorLogan Gunthorpe <logang@deltatee.com>2022-07-08 10:51:02 -0600
committerChristoph Hellwig <hch@lst.de>2022-07-26 07:28:07 -0400
commit495758bb1a72316094ee854dc51f667ad3db29b5 (patch)
tree2c72be9c3fcacde2dfde6e7eb59db6ae03afd171
parent91fb2b6052f75a2f9375db5d5924860ab2313a1d (diff)
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RDMA/core: introduce ib_dma_pci_p2p_dma_supported()
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> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
-rw-r--r--drivers/nvme/target/rdma.c2
-rw-r--r--include/rdma/ib_verbs.h11
2 files changed, 12 insertions, 1 deletions
diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 09fdcac87d17..4597bca43a6d 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -415,7 +415,7 @@ 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 9c6317cf80d5..523843d9ed6c 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -4013,6 +4013,17 @@ 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