【BACKPORT】Add Linux SBI MPXY and RPMI drivers

Documentation/devicetree/bindings/clock/riscv,rpmi-clock.yaml

@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/riscv,rpmi-clock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V RPMI clock service group based clock controller
+
+maintainers:
+  - Anup Patel <anup@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 clock service group for accessing
+  system clocks managed by a platform microcontroller. The supervisor
+  software can access RPMI clock service group via SBI MPXY channel or
+  some dedicated supervisor-mode RPMI transport.
+
+  ===========================================
+  References
+  ===========================================
+
+  [1] RISC-V Platform Management Interface (RPMI) v1.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-rpmi/releases
+
+  [2] RISC-V Supervisor Binary Interface (SBI) v3.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-sbi-doc/releases
+
+properties:
+  compatible:
+    description:
+      Intended for use by the supervisor software.
+    const: riscv,rpmi-clock
+
+  mboxes:
+    maxItems: 1
+    description:
+      Mailbox channel of the underlying RPMI transport or SBI message proxy channel.
+
+  "#clock-cells":
+    const: 1
+    description:
+      Platform specific CLOCK_ID as defined by the RISC-V Platform Management
+      Interface (RPMI) specification.
+
+required:
+  - compatible
+  - mboxes
+  - "#clock-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    clock-controller {
+        compatible = "riscv,rpmi-clock";
+        mboxes = <&mpxy_mbox 0x1000 0x0>;
+        #clock-cells = <1>;
+    };
+...

Documentation/devicetree/bindings/clock/riscv,rpmi-mpxy-clock.yaml

@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/riscv,rpmi-mpxy-clock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V RPMI clock service group based message proxy
+
+maintainers:
+  - Anup Patel <anup@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 clock service group for accessing
+  system clocks managed by a platform microcontroller. The SBI implementation
+  (machine mode firmware or hypervisor) can implement an SBI MPXY channel
+  to allow RPMI clock service group access to the supervisor software.
+
+  ===========================================
+  References
+  ===========================================
+
+  [1] RISC-V Platform Management Interface (RPMI) v1.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-rpmi/releases
+
+  [2] RISC-V Supervisor Binary Interface (SBI) v3.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-sbi-doc/releases
+
+properties:
+  compatible:
+    description:
+      Intended for use by the SBI implementation.
+    const: riscv,rpmi-mpxy-clock
+
+  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:
+  - |
+    clock-service {
+        compatible = "riscv,rpmi-mpxy-clock";
+        mboxes = <&rpmi_shmem_mbox 0x8>;
+        riscv,sbi-mpxy-channel-id = <0x1000>;
+    };
+...

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@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
+  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) v1.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-rpmi/releases
+
+  [2] RISC-V Supervisor Binary Interface (SBI) v3.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-sbi-doc/releases
+
+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>;
+    };
+...

Documentation/devicetree/bindings/interrupt-controller/riscv,rpmi-system-msi.yaml

@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/riscv,rpmi-system-msi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V RPMI system MSI service group based interrupt controller
+
+maintainers:
+  - Anup Patel <anup@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 supervisor software can access RPMI system MSI service group via
+  SBI MPXY channel or some dedicated supervisor-mode RPMI transport.
+
+  ===========================================
+  References
+  ===========================================
+
+  [1] RISC-V Platform Management Interface (RPMI) v1.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-rpmi/releases
+
+  [2] RISC-V Supervisor Binary Interface (SBI) v3.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-sbi-doc/releases
+
+allOf:
+  - $ref: /schemas/interrupt-controller.yaml#
+
+properties:
+  compatible:
+    description:
+      Intended for use by the supervisor software.
+    const: riscv,rpmi-system-msi
+
+  mboxes:
+    maxItems: 1
+    description:
+      Mailbox channel of the underlying RPMI transport or SBI message proxy channel.
+
+  msi-parent: true
+
+  interrupt-controller: true
+
+  "#interrupt-cells":
+    const: 1
+
+required:
+  - compatible
+  - mboxes
+  - msi-parent
+  - interrupt-controller
+  - "#interrupt-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    interrupt-controller {
+        compatible = "riscv,rpmi-system-msi";
+        mboxes = <&mpxy_mbox 0x2000 0x0>;
+        msi-parent = <&imsic_slevel>;
+        interrupt-controller;
+        #interrupt-cells = <1>;
+    };
+...

Documentation/devicetree/bindings/mailbox/riscv,rpmi-shmem-mbox.yaml

@@ -0,0 +1,124 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/riscv,rpmi-shmem-mbox.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V Platform Management Interface (RPMI) shared memory mailbox
+
+maintainers:
+  - Anup Patel <anup@brainfault.org>
+
+description: |
+  The RISC-V Platform Management Interface (RPMI) [1] defines a common shared
+  memory based RPMI transport. This RPMI shared memory transport integrates as
+  mailbox controller in the SBI implementation or supervisor software whereas
+  each RPMI service group is mailbox client in the SBI implementation and
+  supervisor software.
+
+  ===========================================
+  References
+  ===========================================
+
+  [1] RISC-V Platform Management Interface (RPMI) v1.0 (or higher)
+      https://github.com/riscv-non-isa/riscv-rpmi/releases
+
+properties:
+  compatible:
+    const: riscv,rpmi-shmem-mbox
+
+  reg:
+    minItems: 2
+    items:
+      - description: A2P request queue base address
+      - description: P2A acknowledgment queue base address
+      - description: P2A request queue base address
+      - description: A2P acknowledgment queue base address
+      - description: A2P doorbell address
+
+  reg-names:
+    minItems: 2
+    items:
+      - const: a2p-req
+      - const: p2a-ack
+      - enum: [ p2a-req, a2p-doorbell ]
+      - const: a2p-ack
+      - const: a2p-doorbell
+
+  interrupts:
+    maxItems: 1
+    description:
+      The RPMI shared memory transport supports P2A doorbell as a wired
+      interrupt and this property specifies the interrupt source.
+
+  msi-parent:
+    description:
+      The RPMI shared memory transport supports P2A doorbell as a system MSI
+      and this property specifies the target MSI controller.
+
+  riscv,slot-size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 64
+    description:
+      Power-of-2 RPMI slot size of the RPMI shared memory transport.
+
+  riscv,a2p-doorbell-value:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 0x1
+    description:
+      Value written to the 32-bit A2P doorbell register.
+
+  riscv,p2a-doorbell-sysmsi-index:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The RPMI shared memory transport supports P2A doorbell as a system MSI
+      and this property specifies system MSI index to be used for configuring
+      the P2A doorbell MSI.
+
+  "#mbox-cells":
+    const: 1
+    description:
+      The first cell specifies RPMI service group ID.
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - riscv,slot-size
+  - "#mbox-cells"
+
+anyOf:
+  - required:
+      - interrupts
+  - required:
+      - msi-parent
+
+additionalProperties: false
+
+examples:
+  - |
+    // Example 1 (RPMI shared memory with only 2 queues):
+    mailbox@10080000 {
+        compatible = "riscv,rpmi-shmem-mbox";
+        reg = <0x10080000 0x10000>,
+              <0x10090000 0x10000>;
+        reg-names = "a2p-req", "p2a-ack";
+        msi-parent = <&imsic_mlevel>;
+        riscv,slot-size = <64>;
+        #mbox-cells = <1>;
+    };
+  - |
+    // Example 2 (RPMI shared memory with only 4 queues):
+    mailbox@10001000 {
+        compatible = "riscv,rpmi-shmem-mbox";
+        reg = <0x10001000 0x800>,
+              <0x10001800 0x800>,
+              <0x10002000 0x800>,
+              <0x10002800 0x800>,
+              <0x10003000 0x4>;
+        reg-names = "a2p-req", "p2a-ack", "p2a-req", "a2p-ack", "a2p-doorbell";
+        msi-parent = <&imsic_mlevel>;
+        riscv,slot-size = <64>;
+        riscv,a2p-doorbell-value = <0x00008000>;
+        #mbox-cells = <1>;
+    };