1 files changed, 162 insertions, 0 deletions
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";
+                };
+        };
+    };
+...