[PATCH for-next v2 0/5] Introduce Completion Counters

[Michael Margolin <mrgolin@amazon.com>]

Add core infrastructure for Completion Counters, a light-weight
alternative to polling CQ for tracking operation completions. The
related rdma-core interface proposal is linked in [1].

Define the UVERBS_OBJECT_COMP_CNTR ioctl object with create, destroy,
set, inc and read methods for both success and error counters. Add a
QP attach method on the QP object to associate a completion counter
with a queue pair.

Completion Counters can be backed by user-provided VA or dmabuf or by
internal device/driver memory. Common command infrastructure allows any
of the implementations to support the various device capabilities.

Add EFA Completion Counters support as first implementer.

[1] https://github.com/linux-rdma/rdma-core/pull/1701

---
Changes in v2:
- United set, inc and read flows for successful and error completions
  counters
- Added comp_cntr usage count
- Minor cleanups
- Link to v1: https://lore.kernel.org/all/20260407115424.13359-1-mrgolin@amazon.com/

Michael Margolin (5):
  RDMA/core: Add Completion Counters support
  RDMA/core: Prevent destroying in-use completion counters
  RDMA/core: Add Completion Counters to resource tracking
  RDMA/efa: Update device interface
  RDMA/efa: Add Completion Counters support

 drivers/infiniband/core/Makefile              |   1 +
 drivers/infiniband/core/device.c              |   7 +
 drivers/infiniband/core/nldev.c               |   1 +
 drivers/infiniband/core/rdma_core.h           |   1 +
 drivers/infiniband/core/restrack.c            |   2 +
 drivers/infiniband/core/uverbs_cmd.c          |   1 +
 .../core/uverbs_std_types_comp_cntr.c         | 299 ++++++++++++++++++
 drivers/infiniband/core/uverbs_std_types_qp.c |  65 +++-
 drivers/infiniband/core/uverbs_uapi.c         |   1 +
 drivers/infiniband/core/verbs.c               |   1 +
 drivers/infiniband/hw/efa/efa.h               |  13 +
 .../infiniband/hw/efa/efa_admin_cmds_defs.h   | 185 ++++++++++-
 drivers/infiniband/hw/efa/efa_com_cmd.c       | 106 +++++++
 drivers/infiniband/hw/efa/efa_com_cmd.h       |  36 +++
 drivers/infiniband/hw/efa/efa_io_defs.h       |  62 +++-
 drivers/infiniband/hw/efa/efa_main.c          |   6 +
 drivers/infiniband/hw/efa/efa_verbs.c         | 171 ++++++++++
 include/rdma/ib_verbs.h                       |  41 +++
 include/rdma/restrack.h                       |   4 +
 include/uapi/rdma/efa-abi.h                   |   1 +
 include/uapi/rdma/ib_user_ioctl_cmds.h        |  50 +++
 include/uapi/rdma/ib_user_ioctl_verbs.h       |  14 +
 include/uapi/rdma/ib_user_verbs.h             |   2 +-
 23 files changed, 1063 insertions(+), 7 deletions(-)
 create mode 100644 drivers/infiniband/core/uverbs_std_types_comp_cntr.c

-- 
2.47.3