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diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml new file mode 100644 index 000000000..c6925e0b1 --- /dev/null +++ b/Documentation/devicetree/bindings/riscv/cpus.yaml @@ -0,0 +1,162 @@ +# 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 bindings for 'cpus' DT nodes + +maintainers: + - Paul Walmsley <paul.walmsley@sifive.com> + - Palmer Dabbelt <palmer@sifive.com> + +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. + +properties: + compatible: + oneOf: + - items: + - enum: + - sifive,rocket0 + - sifive,e5 + - sifive,e51 + - sifive,u54-mc + - sifive,u54 + - sifive,u5 + - 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 MMU address translation mode used on 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,isa: + description: + Identifies the specific RISC-V instruction set architecture + supported by the hart. These are documented in the RISC-V + User-Level ISA document, available from + https://riscv.org/specifications/ + + While the isa strings in ISA specification are case + insensitive, letters in the riscv,isa string must be all + lowercase to simplify parsing. + $ref: "/schemas/types.yaml#/definitions/string" + enum: + - rv64imac + - rv64imafdc + + # RISC-V requires 'timebase-frequency' in /cpus, so disallow it here + timebase-frequency: false + + interrupt-controller: + type: object + 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 + +required: + - riscv,isa + - interrupt-controller + +additionalProperties: true + +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 = "rv64imac"; + 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>; + riscv,isa = "rv64imafdc"; + tlb-split; + 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"; + riscv,isa = "rv64imafdc"; + mmu-type = "riscv,sv48"; + interrupt-controller { + #interrupt-cells = <1>; + interrupt-controller; + compatible = "riscv,cpu-intc"; + }; + }; + }; +... |