[PATCH RFC v3 0/9] tee: optee: add RPMI backend support on RISC-V

[Amirreza Zarrabi]

This series adds an RPMI backend to the OP-TEE driver for RISC-V.
It builds on the separately posted RPMI TEE transport series [1],
which provides service discovery, synchronous calls, memory parcels
and asynchronous signals.

This revision is effectively a full rewrite of the original RFC.
The generic RPMI transport has been separated from the OP-TEE backend,
and the backend has been reworked around the service bus and a new
OP-TEE control ABI.

Unlike v1, the OP-TEE backend no longer manages SBI MPXY mailbox
channels or implements RPMI TEE service-group operations directly.
It binds to the OP-TEE service UUID on the RPMI TEE bus and uses the
transport's public operations. No additional OP-TEE device-tree node
is required.

The backend reuses the common OP-TEE session, shared-memory, argument
cache, call queue and RPC infrastructure. Shared memory is represented
by RPMI parcel IDs and nonces. Yielding calls pass command and RPC
buffer ranges within a parcel and resume suspended execution using
an opaque token returned by OP-TEE.

The OP-TEE control ABI uses fixed-width little-endian messages carried
in TEE_CALL payloads rather than reproducing FF-A's register-based
message layout. Asynchronous notifications use an allocated TEE-to-REE
signal as a bottom-half doorbell, while ordinary logical notifications
continue through the common RPC path.

Matching OP-TEE OS support has been implemented locally. OpenSBI
integration and end-to-end validation remain pending. This remains an
RFC for review of the backend integration and Linux-to-OP-TEE protocol.

This series depends on:

- The RPMI TEE transport series [1].
- The OP-TEE notification bitmap fix, which allocates space for the
  inclusive maximum notification key [2].

[1] https://lore.kernel.org/op-tee/20261007-riscv-rpmi-tee-abi-v2-0-45939a13d223@oss.qualcomm.com/
[2] https://lore.kernel.org/op-tee/20261009-fix-tee-max-keys-v1-1-1462d96bf438@oss.qualcomm.com/

Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi at oss.qualcomm.com>
---
Changes in v3:
- Use GlobalPlatform TEE result codes for OP-TEE control responses,
  keeping them separate from RPMI transport errors.
- Combine the parcel ID and nonce into a single 64-bit global_id.
- Make resume tokens opaque 32-bit values and track initial versus
  resumed calls separately.
- Remove unnecessary __packed annotations from the OP-TEE ABI structures.
- Share the global-ID-to-SHM mapping implementation between the FF-A
  and RPMI backends.
- Replace the fixed SHM nonce with a per-instance IDA allocator; reuse
  nonces after successful reclamation.
- Report the maximum notification key instead of a notification count,
  and use the negotiated maximum during initialization.
- Consume capability-exchange results during probe.
- Remove cleanup macros and use explicit resource-management paths.
- Use rc consistently for Linux error returns.
- Replace unnecessary unaligned accesses with endian conversions for
  naturally aligned ABI fields.
- Link to v2: https://lore.kernel.org/r/20261005-rpmi-tee-service-grp-dev-v2-0-72f222e23ec1@oss.qualcomm.com

Changes in v2:
- Effectively rewrite the backend around the separately posted RPMI
  TEE transport and a new OP-TEE control ABI.
- Remove backend-owned per-hart mailbox channels and the OP-TEE-specific
  device-tree binding.
- Replace the register-like control payload with fixed-width messages,
  explicit command/RPC buffer ranges and opaque resume tokens.
- Add a parcel-reference parameter layout carrying the parcel ID,
  nonce, and 64-bit offset and size without changing parameter size.
- Make argument-offset support part of the baseline ABI and retain
  the common shared argument cache.
- Use a transport-allocated signal for asynchronous bottom-half
  notifications.
- Link to v1: https://lore.kernel.org/r/20260912-rpmi-tee-service-grp-dev-v1-0-1d1d35c2a859@oss.qualcomm.com

---
Amirreza Zarrabi (9):
      tee: optee: share the global shared-memory ID mapping
      tee: optee: allow RPMI transport builds on RISC-V
      tee: optee: define the RPMI control and parcel-reference ABI
      tee: optee: add RPMI shared-memory and parameter support
      tee: optee: add RPMI dynamic shared-memory pool
      tee: optee: add RPMI RPC handling
      tee: optee: execute yielding RPMI calls
      tee: optee: bind RPMI services and negotiate backend capabilities
      tee: optee: support RPMI asynchronous notification doorbells

 drivers/tee/Kconfig                |   3 +-
 drivers/tee/optee/Kconfig          |   3 +-
 drivers/tee/optee/Makefile         |   2 +
 drivers/tee/optee/call.c           |   2 +
 drivers/tee/optee/core.c           |  10 +-
 drivers/tee/optee/ffa_abi.c        | 133 +----
 drivers/tee/optee/optee_msg.h      |  23 +-
 drivers/tee/optee/optee_private.h  |  73 ++-
 drivers/tee/optee/optee_rpmi.h     | 263 ++++++++++
 drivers/tee/optee/rpmi_abi.c       | 972 +++++++++++++++++++++++++++++++++++++
 drivers/tee/optee/shm_handle_map.c | 138 ++++++
 11 files changed, 1498 insertions(+), 124 deletions(-)
---
base-commit: bf1ee2bd5c2da8992f33c8950ef194aaff74ed6c
change-id: 20260912-rpmi-tee-service-grp-dev-b2ce2f63e0df

Best regards,
-- 
Amirreza Zarrabi <amirreza.zarrabi at oss.qualcomm.com>