RDMA support for DMA handle

From Yishai,

This patch series introduces a new DMA Handle (DMAH) object, along with corresponding APIs for its allocation and deallocation.

The DMAH object encapsulates attributes relevant for DMA transactions.

While initially intended to support TLP Processing Hints (TPH) [1], the design is extensible to accommodate future features such as PCI multipath for DMA, PCI UIO configurations, traffic class selection, and more.

Additionally, we introduce a new ioctl method on the MR object:
UVERBS_METHOD_REG_MR.

This method consolidates multiple reg_mr variants under a single user-space ioctl interface, supporting: ibv_reg_mr(), ibv_reg_mr_iova(), ibv_reg_mr_iova2() and ibv_reg_dmabuf_mr(). It also enables passing a DMA handle as part of the registration process.

Throughout the patch series, the following DMAH-related stuff can also be observed in the IB layer:

- Association with a CPU ID and its memory type, for use with Steering Tags [2].

- Inclusion of Processing Hints (PH) data for TPH functionality [3].

- Enforces security by ensuring that only tasks allowed to run on a given CPU may request a DMA handle for it.

- Reference counting for DMAH life cycle management and safe usage across memory regions.

mlx5 driver implementation:
--------------------------
The series includes implementation of the above functionality in the mlx5 driver.

In mlx5_core:
- Enables TPH over PCIe when both firmware and OS support it.

- Manages Steering Tags and corresponding indices by writing tag values to the PCI configuration space.

- Exposes APIs to upper layers (e.g., mlx5_ib) to enable the PCIe TPH functionality.

In mlx5_ib:
- Adds full support for DMAH operations.

- Utilizes mlx5_core's Steering Tag APIs to derive tag indices from input.

- Stores the resulting index in a mlx5_dmah structure for use during MKEY creation with a DMA handle.

- Adds support for allowing MKEYs to be created in conjunction with DMA handles.

Additional details are provided in the commit messages.

[1] Background, from PCIe specification 6.2.
TLP Processing Hints (TPH)
--------------------------
TLP Processing Hints is an optional feature that provides hints in Request TLP headers to facilitate optimized processing of Requests that target Memory Space. These Processing Hints enable the system hardware (e.g., the Root Complex and/ or Endpoints) to optimize platform resources such as system and memory interconnect on a per TLP basis. Steering Tags are system-specific values used to identify a processing resource that a Requester explicitly targets. System software discovers and identifies TPH capabilities to determine the Steering Tag allocation for each Function that supports TPH

[2] Steering Tags
Functions that intend to target a TLP towards a specific processing resource such as a host processor or system cache hierarchy require topological information of the target cache (e.g., which host cache). Steering Tags are system-specific values that provide information about the host or cache structure in the system cache hierarchy. These values are used to associate processing elements within the platform with the processing of Requests.

[3] Processing Hints
The Requester provides hints to the Root Complex or other targets about the intended use of data and data structures by the host and/or device. The hints are provided by the Requester, which has knowledge of upcoming Request patterns, and which the Completer would not be able to deduce autonomously (with good accuracy)

Yishai

Yishai Hadas (8):
pci/tph: Expose pcie_tph_get_st_table_size() net/mlx5: Expose IFC bits for TPH
net/mlx5: Add support for device steering tag IB/core: Add UVERBS_METHOD_REG_MR on the MR object RDMA/core: Introduce a DMAH object and its alloc/free APIs RDMA/mlx5: Add DMAH object support
IB: Extend UVERBS_METHOD_REG_MR to get DMAH RDMA/mlx5: Add DMAH support for reg_user_mr/reg_user_dmabuf_mr

 drivers/infiniband/core/Makefile              |   1 +
 drivers/infiniband/core/device.c              |   3 +
 drivers/infiniband/core/rdma_core.h           |   1 +
 drivers/infiniband/core/restrack.c            |   2 +
 drivers/infiniband/core/uverbs_cmd.c          |   2 +-
 .../infiniband/core/uverbs_std_types_dmah.c   | 151 ++++++++++++++++
 drivers/infiniband/core/uverbs_std_types_mr.c | 170 +++++++++++++++++-
 drivers/infiniband/core/uverbs_uapi.c         |   1 +
 drivers/infiniband/core/verbs.c               |   5 +-
 drivers/infiniband/hw/bnxt_re/ib_verbs.c      |   8 +
 drivers/infiniband/hw/bnxt_re/ib_verbs.h      |   2 +
 drivers/infiniband/hw/cxgb4/iw_cxgb4.h        |   1 +
 drivers/infiniband/hw/cxgb4/mem.c             |   6 +-
 drivers/infiniband/hw/efa/efa.h               |   2 +
 drivers/infiniband/hw/efa/efa_verbs.c         |   8 +
 drivers/infiniband/hw/erdma/erdma_verbs.c     |   6 +-
 drivers/infiniband/hw/erdma/erdma_verbs.h     |   3 +-
 drivers/infiniband/hw/hns/hns_roce_device.h   |   1 +
 drivers/infiniband/hw/hns/hns_roce_mr.c       |   4 +
 drivers/infiniband/hw/irdma/verbs.c           |   9 +
 drivers/infiniband/hw/mana/mana_ib.h          |   2 +
 drivers/infiniband/hw/mana/mr.c               |   8 +
 drivers/infiniband/hw/mlx4/mlx4_ib.h          |   1 +
 drivers/infiniband/hw/mlx4/mr.c               |   4 +
 drivers/infiniband/hw/mlx5/Makefile           |   1 +
 drivers/infiniband/hw/mlx5/devx.c             |   4 +
 drivers/infiniband/hw/mlx5/dmah.c             |  54 ++++++
 drivers/infiniband/hw/mlx5/dmah.h             |  23 +++
 drivers/infiniband/hw/mlx5/main.c             |   5 +
 drivers/infiniband/hw/mlx5/mlx5_ib.h          |   7 +
 drivers/infiniband/hw/mlx5/mr.c               | 103 +++++++++--
 drivers/infiniband/hw/mlx5/odp.c              |   1 +
 drivers/infiniband/hw/mthca/mthca_provider.c  |   6 +-
 drivers/infiniband/hw/ocrdma/ocrdma_verbs.c   |   6 +-
 drivers/infiniband/hw/ocrdma/ocrdma_verbs.h   |   3 +-
 drivers/infiniband/hw/qedr/verbs.c            |   6 +-
 drivers/infiniband/hw/qedr/verbs.h            |   3 +-
 drivers/infiniband/hw/usnic/usnic_ib_verbs.c  |   4 +
 drivers/infiniband/hw/usnic/usnic_ib_verbs.h  |   1 +
 drivers/infiniband/hw/vmw_pvrdma/pvrdma_mr.c  |   5 +
 .../infiniband/hw/vmw_pvrdma/pvrdma_verbs.h   |   1 +
 drivers/infiniband/sw/rdmavt/mr.c             |   5 +
 drivers/infiniband/sw/rdmavt/mr.h             |   1 +
 drivers/infiniband/sw/rxe/rxe_verbs.c         |   4 +
 drivers/infiniband/sw/siw/siw_verbs.c         |   7 +-
 drivers/infiniband/sw/siw/siw_verbs.h         |   3 +-
 .../net/ethernet/mellanox/mlx5/core/Makefile  |   5 +
 .../net/ethernet/mellanox/mlx5/core/lib/st.c  | 162 +++++++++++++++++
 .../net/ethernet/mellanox/mlx5/core/main.c    |   2 +
 .../ethernet/mellanox/mlx5/core/mlx5_core.h   |   9 +
 drivers/pci/tph.c                             |  11 +-
 include/linux/mlx5/driver.h                   |  20 +++
 include/linux/mlx5/mlx5_ifc.h                 |  14 +-
 include/linux/pci-tph.h                       |   1 +
 include/rdma/ib_verbs.h                       |  31 ++++
 include/rdma/restrack.h                       |   4 +
 include/uapi/rdma/ib_user_ioctl_cmds.h        |  32 ++++
 57 files changed, 905 insertions(+), 40 deletions(-)
 create mode 100644 drivers/infiniband/core/uverbs_std_types_dmah.c
 create mode 100644 drivers/infiniband/hw/mlx5/dmah.c
 create mode 100644 drivers/infiniband/hw/mlx5/dmah.h
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/lib/st.c

2.50.0