kernel

linux-6.8.1/Documentation/devicetree/bindings/riscv/cpus.yaml

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+# SPDX-License-Identifier: (GPL-2.0 OR MIT)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/riscv/cpus.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V CPUs
+
+maintainers:
+  - Paul Walmsley <paul.walmsley@sifive.com>
+  - Palmer Dabbelt <palmer@sifive.com>
+  - Conor Dooley <conor@kernel.org>
+
+description: |
+  This document uses some terminology common to the RISC-V community
+  that is not widely used, the definitions of which are listed here:
+
+  hart: A hardware execution context, which contains all the state
+  mandated by the RISC-V ISA: a PC and some registers.  This
+  terminology is designed to disambiguate software's view of execution
+  contexts from any particular microarchitectural implementation
+  strategy.  For example, an Intel laptop containing one socket with
+  two cores, each of which has two hyperthreads, could be described as
+  having four harts.
+
+allOf:
+  - $ref: /schemas/cpu.yaml#
+  - $ref: extensions.yaml
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - amd,mbv32
+              - andestech,ax45mp
+              - canaan,k210
+              - sifive,bullet0
+              - sifive,e5
+              - sifive,e7
+              - sifive,e71
+              - sifive,rocket0
+              - sifive,s7
+              - sifive,u5
+              - sifive,u54
+              - sifive,u7
+              - sifive,u74
+              - sifive,u74-mc
+              - thead,c906
+              - thead,c910
+              - thead,c920
+          - const: riscv
+      - items:
+          - enum:
+              - sifive,e51
+              - sifive,u54-mc
+          - const: sifive,rocket0
+          - const: riscv
+      - const: riscv    # Simulator only
+    description:
+      Identifies that the hart uses the RISC-V instruction set
+      and identifies the type of the hart.
+
+  mmu-type:
+    description:
+      Identifies the largest MMU address translation mode supported by
+      this hart.  These values originate from the RISC-V Privileged
+      Specification document, available from
+      https://riscv.org/specifications/
+    $ref: /schemas/types.yaml#/definitions/string
+    enum:
+      - riscv,sv32
+      - riscv,sv39
+      - riscv,sv48
+      - riscv,sv57
+      - riscv,none
+
+  riscv,cbom-block-size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The blocksize in bytes for the Zicbom cache operations.
+
+  riscv,cbop-block-size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The blocksize in bytes for the Zicbop cache operations.
+
+  riscv,cboz-block-size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The blocksize in bytes for the Zicboz cache operations.
+
+  # RISC-V has multiple properties for cache op block sizes as the sizes
+  # differ between individual CBO extensions
+  cache-op-block-size: false
+  # RISC-V requires 'timebase-frequency' in /cpus, so disallow it here
+  timebase-frequency: false
+
+  interrupt-controller:
+    type: object
+    additionalProperties: false
+    description: Describes the CPU's local interrupt controller
+
+    properties:
+      '#interrupt-cells':
+        const: 1
+
+      compatible:
+        const: riscv,cpu-intc
+
+      interrupt-controller: true
+
+    required:
+      - '#interrupt-cells'
+      - compatible
+      - interrupt-controller
+
+  cpu-idle-states:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      maxItems: 1
+    description: |
+      List of phandles to idle state nodes supported
+      by this hart (see ./idle-states.yaml).
+
+  capacity-dmips-mhz:
+    description:
+      u32 value representing CPU capacity (see ../cpu/cpu-capacity.txt) in
+      DMIPS/MHz, relative to highest capacity-dmips-mhz
+      in the system.
+
+anyOf:
+  - required:
+      - riscv,isa
+  - required:
+      - riscv,isa-base
+
+dependencies:
+  riscv,isa-base: [ "riscv,isa-extensions" ]
+  riscv,isa-extensions: [ "riscv,isa-base" ]
+
+required:
+  - interrupt-controller
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    // Example 1: SiFive Freedom U540G Development Kit
+    cpus {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        timebase-frequency = <1000000>;
+        cpu@0 {
+                clock-frequency = <0>;
+                compatible = "sifive,rocket0", "riscv";
+                device_type = "cpu";
+                i-cache-block-size = <64>;
+                i-cache-sets = <128>;
+                i-cache-size = <16384>;
+                reg = <0>;
+                riscv,isa-base = "rv64i";
+                riscv,isa-extensions = "i", "m", "a", "c";
+
+                cpu_intc0: interrupt-controller {
+                        #interrupt-cells = <1>;
+                        compatible = "riscv,cpu-intc";
+                        interrupt-controller;
+                };
+        };
+        cpu@1 {
+                clock-frequency = <0>;
+                compatible = "sifive,rocket0", "riscv";
+                d-cache-block-size = <64>;
+                d-cache-sets = <64>;
+                d-cache-size = <32768>;
+                d-tlb-sets = <1>;
+                d-tlb-size = <32>;
+                device_type = "cpu";
+                i-cache-block-size = <64>;
+                i-cache-sets = <64>;
+                i-cache-size = <32768>;
+                i-tlb-sets = <1>;
+                i-tlb-size = <32>;
+                mmu-type = "riscv,sv39";
+                reg = <1>;
+                tlb-split;
+                riscv,isa-base = "rv64i";
+                riscv,isa-extensions = "i", "m", "a", "f", "d", "c";
+
+                cpu_intc1: interrupt-controller {
+                        #interrupt-cells = <1>;
+                        compatible = "riscv,cpu-intc";
+                        interrupt-controller;
+                };
+        };
+    };
+
+  - |
+    // Example 2: Spike ISA Simulator with 1 Hart
+    cpus {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        cpu@0 {
+                device_type = "cpu";
+                reg = <0>;
+                compatible = "riscv";
+                mmu-type = "riscv,sv48";
+                riscv,isa-base = "rv64i";
+                riscv,isa-extensions = "i", "m", "a", "f", "d", "c";
+
+                interrupt-controller {
+                        #interrupt-cells = <1>;
+                        interrupt-controller;
+                        compatible = "riscv,cpu-intc";
+                };
+        };
+    };
+...