Merge branch 'pci/peer-to-peer'

  - Add PCI support for peer-to-peer DMA (Logan Gunthorpe)

  - Add sysfs group for PCI peer-to-peer memory statistics (Logan
    Gunthorpe)

  - Add PCI peer-to-peer DMA scatterlist mapping interface (Logan
    Gunthorpe)

  - Add PCI configfs/sysfs helpers for use by peer-to-peer users (Logan
    Gunthorpe)

  - Add PCI peer-to-peer DMA driver writer's documentation (Logan
    Gunthorpe)

  - Add block layer flag to indicate driver support for PCI peer-to-peer
    DMA (Logan Gunthorpe)

  - Map Infiniband scatterlists for peer-to-peer DMA if they contain P2P
    memory (Logan Gunthorpe)

  - Register nvme-pci CMB buffer as PCI peer-to-peer memory (Logan
    Gunthorpe)

  - Add nvme-pci support for PCI peer-to-peer memory in requests (Logan
    Gunthorpe)

  - Use PCI peer-to-peer memory in nvme (Stephen Bates, Steve Wise,
    Christoph Hellwig, Logan Gunthorpe)

* pci/peer-to-peer:
  nvmet: Optionally use PCI P2P memory
  nvmet: Introduce helper functions to allocate and free request SGLs
  nvme-pci: Add support for P2P memory in requests
  nvme-pci: Use PCI p2pmem subsystem to manage the CMB
  IB/core: Ensure we map P2P memory correctly in rdma_rw_ctx_[init|destroy]()
  block: Add PCI P2P flag for request queue
  PCI/P2PDMA: Add P2P DMA driver writer's documentation
  docs-rst: Add a new directory for PCI documentation
  PCI/P2PDMA: Introduce configfs/sysfs enable attribute helpers
  PCI/P2PDMA: Add PCI p2pmem DMA mappings to adjust the bus offset
  PCI/P2PDMA: Add sysfs group to display p2pmem stats
  PCI/P2PDMA: Support peer-to-peer memory