[PATCH v4 11/23] dt-bindings: Add RPMI system MSI message proxy bindings

[Atish Patra]

On 5/25/25 1:46 AM, Anup Patel wrote:
> Add device tree bindings for the RPMI system MSI service group
> based message proxy implemented by the SBI implementation (machine
> mode firmware or hypervisor).
>
> The RPMI system MSI service group is defined by the RISC-V
> platform management interface (RPMI) specification.
>
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> ---
>   .../riscv,rpmi-mpxy-system-msi.yaml           | 67 +++++++++++++++++++
>   1 file changed, 67 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,rpmi-mpxy-system-msi.yaml
>
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,rpmi-mpxy-system-msi.yaml b/Documentation/devicetree/bindings/interrupt-controller/riscv,rpmi-mpxy-system-msi.yaml
> new file mode 100644
> index 000000000000..26dd13731350
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,rpmi-mpxy-system-msi.yaml
> @@ -0,0 +1,67 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/interrupt-controller/riscv,rpmi-mpxy-system-msi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: RISC-V RPMI system MSI service group based message proxy
> +
> +maintainers:
> +  - Anup Patel <anup at brainfault.org>
> +
> +description: |
> +  The RISC-V Platform Management Interface (RPMI) [1] defines a
> +  messaging protocol which is modular and extensible. The supervisor
> +  software can send/receive RPMI messages via SBI MPXY extension [2]
> +  or some dedicated supervisor-mode RPMI transport.
> +
> +  The RPMI specification [1] defines system MSI service group which
> +  allow application processors to receive MSIs upon system events
> +  such as P2A doorbell, graceful shutdown/reboot request, CPU hotplug
> +  event, memory hotplug event, etc from the platform microcontroller.
> +  The SBI implementation machine mode firmware or hypervisor) can
nit:
The SBI implementation in machine mode
> +  implement an SBI MPXY channel to allow RPMI system MSI service
> +  group access to the supervisor software.
> +
> +  ===========================================
> +  References
> +  ===========================================
> +
> +  [1] RISC-V Platform Management Interface (RPMI)
> +      https://github.com/riscv-non-isa/riscv-rpmi/releases
> +
> +  [2] RISC-V Supervisor Binary Interface (SBI)
> +      https://github.com/riscv-non-isa/riscv-sbi-doc/releases
> +
nit: Refer the latest frozen version of the spec ?
> +properties:
> +  compatible:
> +    description:
> +      Intended for use by the SBI implementation.
> +    const: riscv,rpmi-mpxy-system-msi
> +
> +  mboxes:
> +    maxItems: 1
> +    description:
> +      Mailbox channel of the underlying RPMI transport.
> +
> +  riscv,sbi-mpxy-channel-id:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      The SBI MPXY channel id to be used for providing RPMI access to
> +      the supervisor software.
> +
> +required:
> +  - compatible
> +  - mboxes
> +  - riscv,sbi-mpxy-channel-id
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    interrupt-controller {
> +        compatible = "riscv,rpmi-mpxy-system-msi";
> +        mboxes = <&rpmi_shmem_mbox 0x2>;
> +        riscv,sbi-mpxy-channel-id = <0x2000>;
> +    };
> +...

Otherwise, lgtm.

Reviewed-by: Atish Patra <atishp at rivosinc.com>