From: Rob Herring robh@kernel.org
The binding is designed around the assumption that an MSC will be a sub-block of something else such as a memory controller, cache controller, or IOMMU. However, it's certainly possible a design does not have that association or has a mixture of both, so the binding illustrates how we can support that with RIS child nodes.
A key part of MPAM is we need to know about all of the MSCs in the system before it can be enabled. This drives the need for the genericish 'arm,mpam-msc' compatible. Though we can't assume an MSC is accessible until a h/w specific driver potentially enables the h/w.
Cc: James Morse james.morse@arm.com Signed-off-by: Rob Herring robh@kernel.org Signed-off-by: James Morse james.morse@arm.com --- .../devicetree/bindings/arm/arm,mpam-msc.yaml | 227 ++++++++++++++++++ 1 file changed, 227 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml
diff --git a/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml b/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml new file mode 100644 index 000000000000..9d542ecb1a7d --- /dev/null +++ b/Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml @@ -0,0 +1,227 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/arm/arm,mpam-msc.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Arm Memory System Resource Partitioning and Monitoring (MPAM) + +description: | + The Arm MPAM specification can be found here: + + https://developer.arm.com/documentation/ddi0598/latest + +maintainers: + - Rob Herring robh@kernel.org + +properties: + compatible: + items: + - const: arm,mpam-msc # Further details are discoverable + - const: arm,mpam-memory-controller-msc + + reg: + maxItems: 1 + description: A memory region containing registers as defined in the MPAM + specification. + + interrupts: + minItems: 1 + items: + - description: error (optional) + - description: overflow (optional, only for monitoring) + + interrupt-names: + oneOf: + - items: + - enum: [ error, overflow ] + - items: + - const: error + - const: overflow + + arm,not-ready-us: + description: The maximum time in microseconds for monitoring data to be + accurate after a settings change. For more information, see the + Not-Ready (NRDY) bit description in the MPAM specification. + + numa-node-id: true # see NUMA binding + + '#address-cells': + const: 1 + + '#size-cells': + const: 0 + +patternProperties: + '^ris@[0-9a-f]$': + type: object + additionalProperties: false + description: | + RIS nodes for each RIS in an MSC. These nodes are required for each RIS + implementing known MPAM controls + + properties: + compatible: + enum: + # Bulk storage for cache + - arm,mpam-cache + # Memory bandwidth + - arm,mpam-memory + + reg: + minimum: 0 + maximum: 0xf + + cpus: + $ref: '/schemas/types.yaml#/definitions/phandle-array' + description: + Phandle(s) to the CPU node(s) this RIS belongs to. By default, the parent + device's affinity is used. + + arm,mpam-device: + $ref: '/schemas/types.yaml#/definitions/phandle' + description: + By default, the MPAM enabled device associated with a RIS is the MSC's + parent node. It is possible for each RIS to be associated with different + devices in which case 'arm,mpam-device' should be used. + + required: + - compatible + - reg + +required: + - compatible + - reg + +dependencies: + interrupts: [ interrupt-names ] + +additionalProperties: false + +examples: + - | + /* + cpus { + cpu@0 { + next-level-cache = <&L2_0>; + }; + cpu@100 { + next-level-cache = <&L2_1>; + }; + }; + */ + L2_0: cache-controller-0 { + compatible = "cache"; + cache-level = <2>; + cache-unified; + next-level-cache = <&L3>; + + }; + + L2_1: cache-controller-1 { + compatible = "cache"; + cache-level = <2>; + cache-unified; + next-level-cache = <&L3>; + + }; + + L3: cache-controller@30000000 { + compatible = "arm,dsu-l3-cache", "cache"; + cache-level = <3>; + cache-unified; + + ranges = <0x0 0x30000000 0x800000>; + #address-cells = <1>; + #size-cells = <1>; + + msc@10000 { + compatible = "arm,mpam-msc"; + + /* CPU affinity implied by parent cache node's */ + reg = <0x10000 0x2000>; + interrupts = <1>, <2>; + interrupt-names = "error", "overflow"; + arm,not-ready-us = <1>; + }; + }; + + mem: memory-controller@20000 { + compatible = "foo,a-memory-controller"; + reg = <0x20000 0x1000>; + + #address-cells = <1>; + #size-cells = <1>; + ranges; + + msc@21000 { + compatible = "arm,mpam-memory-controller-msc", "arm,mpam-msc"; + reg = <0x21000 0x1000>; + interrupts = <3>; + interrupt-names = "error"; + arm,not-ready-us = <1>; + numa-node-id = <1>; + }; + }; + + iommu@40000 { + reg = <0x40000 0x1000>; + + ranges; + #address-cells = <1>; + #size-cells = <1>; + + msc@41000 { + compatible = "arm,mpam-msc"; + reg = <0 0x1000>; + interrupts = <5>, <6>; + interrupt-names = "error", "overflow"; + arm,not-ready-us = <1>; + + #address-cells = <1>; + #size-cells = <0>; + + ris@2 { + compatible = "arm,mpam-cache"; + reg = <0>; + // TODO: How to map to device(s)? + }; + }; + }; + + msc@80000 { + compatible = "foo,a-standalone-msc"; + reg = <0x80000 0x1000>; + + clocks = <&clks 123>; + + ranges; + #address-cells = <1>; + #size-cells = <1>; + + msc@10000 { + compatible = "arm,mpam-msc"; + + reg = <0x10000 0x2000>; + interrupts = <7>; + interrupt-names = "overflow"; + arm,not-ready-us = <1>; + + #address-cells = <1>; + #size-cells = <0>; + + ris@0 { + compatible = "arm,mpam-cache"; + reg = <0>; + arm,mpam-device = <&L2_0>; + }; + + ris@1 { + compatible = "arm,mpam-memory"; + reg = <1>; + arm,mpam-device = <&mem>; + }; + }; + }; + +...