On Thu, Sep 16, 2021 at 05:40:51PM -0600, Logan Gunthorpe wrote:
> 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@xxxxxxxxxxxx>
> ---
> drivers/nvme/target/rdma.c | 2 +-
> include/rdma/ib_verbs.h | 11 +++++++++++
> 2 files changed, 12 insertions(+), 1 deletion(-)
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> +/*
> + * 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;
If someone wants to make rxe/hfi/qib use this stuff then they will
have to teach the the driver to do all the p2p checks and add some
struct ib_device flag
Jason
