From: Marouene Boubakri marouene.boubakri@oss.nxp.com
The OP-TEE driver reaches OP-TEE through the SMC ABI or the FF-A ABI, both specific to Arm, and the TEE subsystem and the OP-TEE driver depend on HAVE_ARM_SMCCC. On RISC-V there is no SMC instruction: OP-TEE runs in a domain isolated by the M-mode firmware and is reached through the RISC-V Platform Management Interface (RPMI), carried on an SBI Message Proxy (MPXY) channel, for which Linux already has a mailbox driver.
This series only puts the build plumbing in place for a third ABI next to the SMC and FF-A ones:
- patch 1 builds the Arm-specific code of the driver only on Arm: smc_abi.c when HAVE_ARM_SMCCC is set and ffa_abi.c when ARM_FFA_TRANSPORT is enabled, with stubs for their registration otherwise. The SMCCC header, the SMC and FF-A specific types and the SMC RPC register parameters in optee_private.h are kept under the same conditions, so that nothing Arm-specific is left in the common part of the driver;
- patch 2 adds an RPMI ABI placeholder: an OPTEE_RPMI_ABI option built when the MPXY mailbox driver is enabled, rpmi_abi.c and its registration from the driver core. The transport is not implemented, so the registration fails with -EOPNOTSUPP;
- patch 3 lets the TEE subsystem and the OP-TEE driver be enabled on RISC-V, and teaches the memory type check of the driver about the RISC-V page attributes, without which the driver does not build there. It is kept separate as it changes the dependencies of the subsystem-wide TEE menu.
There is no functional change. On Arm, OPTEE still depends on HAVE_ARM_SMCCC and the SMC and FF-A ABIs are built whenever they can be registered. On RISC-V the driver builds without any Arm-specific code but no ABI registers, so it does not load. The RPMI transport will be implemented on top of this in a separate series.
Testing: [TODO before posting: riscv64 defconfig plus TEE/OP-TEE, built-in and as modules, and arm64 defconfig plus OP-TEE with FF-A built-in, modular and disabled, with W=1 at every step of the series.]
Marouene Boubakri (3): tee: optee: build the Arm-specific code only on Arm tee: optee: add an RPMI ABI placeholder tee: optee: allow enabling the driver on RISC-V
drivers/tee/Kconfig | 2 +- drivers/tee/optee/Kconfig | 10 +++++- drivers/tee/optee/Makefile | 5 +-- drivers/tee/optee/call.c | 8 +++++ drivers/tee/optee/core.c | 8 +++-- drivers/tee/optee/notif.c | 1 - drivers/tee/optee/optee_private.h | 52 ++++++++++++++++++++++++++++++- drivers/tee/optee/rpmi_abi.c | 23 ++++++++++++++ 8 files changed, 101 insertions(+), 8 deletions(-) create mode 100644 drivers/tee/optee/rpmi_abi.c
base-commit: 827751b699b79a6e569983359c02dce67f81b94c