Hi, This patchset continues my work to to add P2PDMA support to the common dma map operations. This allows for creating SGLs that have both P2PDMA and regular pages which is a necessary step to allowing P2PDMA pages in userspace. The earlier RFC[1] generated a lot of great feedback and I heard no show stopping objections. Thus, I've incorporated all the feedback and have decided to post this as a proper patch series with hopes of eventually getting it in mainline. I'm happy to do a few more passes if anyone has any further feedback or better ideas. This series is based on v5.12-rc6 and a git branch can be found here: https://github.com/sbates130272/linux-p2pmem/ p2pdma_map_ops_v1 Thanks, Logan [1] https://lore.kernel.org/linux-block/20210311233142.7900-1-logang@xxxxxxxxxxxx/ Changes since the RFC: * Added comment and fixed up the pci_get_slot patch. (per Bjorn) * Fixed glaring sg_phys() double offset bug. (per Robin) * Created a new map operation (dma_map_sg_p2pdma()) with a new calling convention instead of modifying the calling convention of dma_map_sg(). (per Robin) * Integrated the two similar pci_p2pdma_dma_map_type() and pci_p2pdma_map_type() functions into one (per Ira) * Reworked some of the logic in the map_sg() implementations into helpers in the p2pdma code. (per Christoph) * Dropped a bunch of unnecessary symbol exports (per Christoph) * Expanded the code in dma_pci_p2pdma_supported() for clarity. (per Ira and Christoph) * Finished off using the new dma_map_sg_p2pdma() call in rdma_rw and removed the old pci_p2pdma_[un]map_sg(). (per Jason) -- Logan Gunthorpe (16): PCI/P2PDMA: Pass gfp_mask flags to upstream_bridge_distance_warn() PCI/P2PDMA: Avoid pci_get_slot() which sleeps PCI/P2PDMA: Attempt to set map_type if it has not been set PCI/P2PDMA: Refactor pci_p2pdma_map_type() to take pagmap and device dma-mapping: Introduce dma_map_sg_p2pdma() lib/scatterlist: Add flag for indicating P2PDMA segments in an SGL PCI/P2PDMA: Make pci_p2pdma_map_type() non-static PCI/P2PDMA: Introduce helpers for dma_map_sg implementations dma-direct: Support PCI P2PDMA pages in dma-direct map_sg dma-mapping: Add flags to dma_map_ops to indicate PCI P2PDMA support iommu/dma: Support PCI P2PDMA pages in dma-iommu map_sg nvme-pci: Check DMA ops when indicating support for PCI P2PDMA nvme-pci: Convert to using dma_map_sg_p2pdma for p2pdma pages nvme-rdma: Ensure dma support when using p2pdma RDMA/rw: use dma_map_sg_p2pdma() PCI/P2PDMA: Remove pci_p2pdma_[un]map_sg() drivers/infiniband/core/rw.c | 50 +++------- drivers/iommu/dma-iommu.c | 66 ++++++++++-- drivers/nvme/host/core.c | 3 +- drivers/nvme/host/nvme.h | 2 +- drivers/nvme/host/pci.c | 39 ++++---- drivers/nvme/target/rdma.c | 3 +- drivers/pci/Kconfig | 2 +- drivers/pci/p2pdma.c | 188 +++++++++++++++++++---------------- include/linux/dma-map-ops.h | 3 + include/linux/dma-mapping.h | 20 ++++ include/linux/pci-p2pdma.h | 53 ++++++---- include/linux/scatterlist.h | 49 ++++++++- include/rdma/ib_verbs.h | 32 ++++++ kernel/dma/direct.c | 25 ++++- kernel/dma/mapping.c | 70 +++++++++++-- 15 files changed, 416 insertions(+), 189 deletions(-) base-commit: e49d033bddf5b565044e2abe4241353959bc9120 -- 2.20.1
