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diff --git a/dts/Bindings/arm/topology.txt b/dts/Bindings/arm/topology.txt deleted file mode 100644 index b0d80c0fb2..0000000000 --- a/dts/Bindings/arm/topology.txt +++ /dev/null @@ -1,475 +0,0 @@ -=========================================== -ARM topology binding description -=========================================== - -=========================================== -1 - Introduction -=========================================== - -In an ARM system, the hierarchy of CPUs is defined through three entities that -are used to describe the layout of physical CPUs in the system: - -- cluster -- core -- thread - -The cpu nodes (bindings defined in [1]) represent the devices that -correspond to physical CPUs and are to be mapped to the hierarchy levels. - -The bottom hierarchy level sits at core or thread level depending on whether -symmetric multi-threading (SMT) is supported or not. - -For instance in a system where CPUs support SMT, "cpu" nodes represent all -threads existing in the system and map to the hierarchy level "thread" above. -In systems where SMT is not supported "cpu" nodes represent all cores present -in the system and map to the hierarchy level "core" above. - -ARM topology bindings allow one to associate cpu nodes with hierarchical groups -corresponding to the system hierarchy; syntactically they are defined as device -tree nodes. - -The remainder of this document provides the topology bindings for ARM, based -on the Devicetree Specification, available from: - -https://www.devicetree.org/specifications/ - -If not stated otherwise, whenever a reference to a cpu node phandle is made its -value must point to a cpu node compliant with the cpu node bindings as -documented in [1]. -A topology description containing phandles to cpu nodes that are not compliant -with bindings standardized in [1] is therefore considered invalid. - -=========================================== -2 - cpu-map node -=========================================== - -The ARM CPU topology is defined within the cpu-map node, which is a direct -child of the cpus node and provides a container where the actual topology -nodes are listed. - -- cpu-map node - - Usage: Optional - On ARM SMP systems provide CPUs topology to the OS. - ARM uniprocessor systems do not require a topology - description and therefore should not define a - cpu-map node. - - Description: The cpu-map node is just a container node where its - subnodes describe the CPU topology. - - Node name must be "cpu-map". - - The cpu-map node's parent node must be the cpus node. - - The cpu-map node's child nodes can be: - - - one or more cluster nodes - - Any other configuration is considered invalid. - -The cpu-map node can only contain three types of child nodes: - -- cluster node -- core node -- thread node - -whose bindings are described in paragraph 3. - -The nodes describing the CPU topology (cluster/core/thread) can only -be defined within the cpu-map node and every core/thread in the system -must be defined within the topology. Any other configuration is -invalid and therefore must be ignored. - -=========================================== -2.1 - cpu-map child nodes naming convention -=========================================== - -cpu-map child nodes must follow a naming convention where the node name -must be "clusterN", "coreN", "threadN" depending on the node type (ie -cluster/core/thread) (where N = {0, 1, ...} is the node number; nodes which -are siblings within a single common parent node must be given a unique and -sequential N value, starting from 0). -cpu-map child nodes which do not share a common parent node can have the same -name (ie same number N as other cpu-map child nodes at different device tree -levels) since name uniqueness will be guaranteed by the device tree hierarchy. - -=========================================== -3 - cluster/core/thread node bindings -=========================================== - -Bindings for cluster/cpu/thread nodes are defined as follows: - -- cluster node - - Description: must be declared within a cpu-map node, one node - per cluster. A system can contain several layers of - clustering and cluster nodes can be contained in parent - cluster nodes. - - The cluster node name must be "clusterN" as described in 2.1 above. - A cluster node can not be a leaf node. - - A cluster node's child nodes must be: - - - one or more cluster nodes; or - - one or more core nodes - - Any other configuration is considered invalid. - -- core node - - Description: must be declared in a cluster node, one node per core in - the cluster. If the system does not support SMT, core - nodes are leaf nodes, otherwise they become containers of - thread nodes. - - The core node name must be "coreN" as described in 2.1 above. - - A core node must be a leaf node if SMT is not supported. - - Properties for core nodes that are leaf nodes: - - - cpu - Usage: required - Value type: <phandle> - Definition: a phandle to the cpu node that corresponds to the - core node. - - If a core node is not a leaf node (CPUs supporting SMT) a core node's - child nodes can be: - - - one or more thread nodes - - Any other configuration is considered invalid. - -- thread node - - Description: must be declared in a core node, one node per thread - in the core if the system supports SMT. Thread nodes are - always leaf nodes in the device tree. - - The thread node name must be "threadN" as described in 2.1 above. - - A thread node must be a leaf node. - - A thread node must contain the following property: - - - cpu - Usage: required - Value type: <phandle> - Definition: a phandle to the cpu node that corresponds to - the thread node. - -=========================================== -4 - Example dts -=========================================== - -Example 1 (ARM 64-bit, 16-cpu system, two clusters of clusters): - -cpus { - #size-cells = <0>; - #address-cells = <2>; - - cpu-map { - cluster0 { - cluster0 { - core0 { - thread0 { - cpu = <&CPU0>; - }; - thread1 { - cpu = <&CPU1>; - }; - }; - - core1 { - thread0 { - cpu = <&CPU2>; - }; - thread1 { - cpu = <&CPU3>; - }; - }; - }; - - cluster1 { - core0 { - thread0 { - cpu = <&CPU4>; - }; - thread1 { - cpu = <&CPU5>; - }; - }; - - core1 { - thread0 { - cpu = <&CPU6>; - }; - thread1 { - cpu = <&CPU7>; - }; - }; - }; - }; - - cluster1 { - cluster0 { - core0 { - thread0 { - cpu = <&CPU8>; - }; - thread1 { - cpu = <&CPU9>; - }; - }; - core1 { - thread0 { - cpu = <&CPU10>; - }; - thread1 { - cpu = <&CPU11>; - }; - }; - }; - - cluster1 { - core0 { - thread0 { - cpu = <&CPU12>; - }; - thread1 { - cpu = <&CPU13>; - }; - }; - core1 { - thread0 { - cpu = <&CPU14>; - }; - thread1 { - cpu = <&CPU15>; - }; - }; - }; - }; - }; - - CPU0: cpu@0 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x0 0x0>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU1: cpu@1 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x0 0x1>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU2: cpu@100 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x0 0x100>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU3: cpu@101 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x0 0x101>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU4: cpu@10000 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x0 0x10000>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU5: cpu@10001 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x0 0x10001>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU6: cpu@10100 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x0 0x10100>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU7: cpu@10101 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x0 0x10101>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU8: cpu@100000000 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x1 0x0>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU9: cpu@100000001 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x1 0x1>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU10: cpu@100000100 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x1 0x100>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU11: cpu@100000101 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x1 0x101>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU12: cpu@100010000 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x1 0x10000>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU13: cpu@100010001 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x1 0x10001>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU14: cpu@100010100 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x1 0x10100>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; - - CPU15: cpu@100010101 { - device_type = "cpu"; - compatible = "arm,cortex-a57"; - reg = <0x1 0x10101>; - enable-method = "spin-table"; - cpu-release-addr = <0 0x20000000>; - }; -}; - -Example 2 (ARM 32-bit, dual-cluster, 8-cpu system, no SMT): - -cpus { - #size-cells = <0>; - #address-cells = <1>; - - cpu-map { - cluster0 { - core0 { - cpu = <&CPU0>; - }; - core1 { - cpu = <&CPU1>; - }; - core2 { - cpu = <&CPU2>; - }; - core3 { - cpu = <&CPU3>; - }; - }; - - cluster1 { - core0 { - cpu = <&CPU4>; - }; - core1 { - cpu = <&CPU5>; - }; - core2 { - cpu = <&CPU6>; - }; - core3 { - cpu = <&CPU7>; - }; - }; - }; - - CPU0: cpu@0 { - device_type = "cpu"; - compatible = "arm,cortex-a15"; - reg = <0x0>; - }; - - CPU1: cpu@1 { - device_type = "cpu"; - compatible = "arm,cortex-a15"; - reg = <0x1>; - }; - - CPU2: cpu@2 { - device_type = "cpu"; - compatible = "arm,cortex-a15"; - reg = <0x2>; - }; - - CPU3: cpu@3 { - device_type = "cpu"; - compatible = "arm,cortex-a15"; - reg = <0x3>; - }; - - CPU4: cpu@100 { - device_type = "cpu"; - compatible = "arm,cortex-a7"; - reg = <0x100>; - }; - - CPU5: cpu@101 { - device_type = "cpu"; - compatible = "arm,cortex-a7"; - reg = <0x101>; - }; - - CPU6: cpu@102 { - device_type = "cpu"; - compatible = "arm,cortex-a7"; - reg = <0x102>; - }; - - CPU7: cpu@103 { - device_type = "cpu"; - compatible = "arm,cortex-a7"; - reg = <0x103>; - }; -}; - -=============================================================================== -[1] ARM Linux kernel documentation - Documentation/devicetree/bindings/arm/cpus.yaml |