[PATCH for-next v9 0/6] 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 support is linked in [1].

Define the UVERBS_OBJECT_COMP_CNTR ioctl object with create, destroy,
modify 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.

Add EFA Completion Counters support as first implementer.

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

---
Changes in v9:
- Moved counter max value report from per counter create response to a
  new device level command that aggregates completion counter
  capabilities
- Exposed supported ops in QP attach as part of the above command
  response
- Link to v8: https://lore.kernel.org/all/20260707203427.6923-1-mrgolin@amazon.com/
Changes in v8:
- Added device event counter detach support and its use in attach error
  handling
- Prevented completion counters attach to wrapper QPs
- Added max completion counters report in nldev
- Link to v7: https://lore.kernel.org/all/20260701103448.17895-1-mrgolin@amazon.com/
Changes in v7:
- Rebased on latest rdma for-next
- Link to v6: https://lore.kernel.org/all/20260604114627.6086-1-mrgolin@amazon.com/
Changes in v6:
- Moved to using ib_umem_get_attr util
- Resolved additional Sashiko comments
- Link to v5: https://lore.kernel.org/all/20260526090712.17575-1-mrgolin@amazon.com/
Changes in v5:
- Fixed Sashiko findings
- Minor naming improvements
- Link to v4: https://lore.kernel.org/all/20260511223721.18365-1-mrgolin@amazon.com/
Changes in v4:
- Replaced inc and set commands by a single modify command
- Changed to passing buffers as EFA specific attributes using desc
  struct aligned with the suggested common method of passing and
  consuming umem in RDMA drivers
- Link to v2: https://lore.kernel.org/all/20260416212327.18191-1-mrgolin@amazon.com/
Changes in v3:
- Skipped this version because of a wrong patch list
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 (6):
  RDMA/core: Add Completion Counters support
  RDMA/core: Prevent destroying in-use completion counters
  RDMA/core: Expose Completion Counter capabilities to userspace
  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               |   8 +
 drivers/infiniband/core/rdma_core.h           |   1 +
 drivers/infiniband/core/restrack.c            |   2 +
 .../core/uverbs_std_types_comp_cntr.c         | 168 +++++++++++++
 .../infiniband/core/uverbs_std_types_device.c |  51 +++-
 drivers/infiniband/core/uverbs_std_types_qp.c |  67 ++++-
 drivers/infiniband/core/uverbs_uapi.c         |   1 +
 drivers/infiniband/core/verbs.c               |   8 +
 drivers/infiniband/hw/efa/efa.h               |  20 +-
 .../infiniband/hw/efa/efa_admin_cmds_defs.h   | 186 +++++++++++++-
 drivers/infiniband/hw/efa/efa_com_cmd.c       | 136 ++++++++++
 drivers/infiniband/hw/efa/efa_com_cmd.h       |  45 ++++
 drivers/infiniband/hw/efa/efa_io_defs.h       |  20 +-
 drivers/infiniband/hw/efa/efa_main.c          |   8 +-
 drivers/infiniband/hw/efa/efa_verbs.c         | 237 ++++++++++++++++++
 include/rdma/ib_verbs.h                       |  50 ++++
 include/rdma/restrack.h                       |   4 +
 include/uapi/rdma/efa-abi.h                   |   6 +
 include/uapi/rdma/ib_user_ioctl_cmds.h        |  43 ++++
 include/uapi/rdma/ib_user_ioctl_verbs.h       |  19 ++
 22 files changed, 1080 insertions(+), 8 deletions(-)
 create mode 100644 drivers/infiniband/core/uverbs_std_types_comp_cntr.c

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2.47.3