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Diffstat (limited to 'Documentation/devicetree/bindings')
| -rw-r--r-- | Documentation/devicetree/bindings/arm/cpus.txt | 401 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/arm/topology.txt | 474 |
2 files changed, 828 insertions, 47 deletions
diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt index f32494dbfe19..91304353eea4 100644 --- a/Documentation/devicetree/bindings/arm/cpus.txt +++ b/Documentation/devicetree/bindings/arm/cpus.txt @@ -1,77 +1,384 @@ -* ARM CPUs binding description +================= +ARM CPUs bindings +================= The device tree allows to describe the layout of CPUs in a system through the "cpus" node, which in turn contains a number of subnodes (ie "cpu") defining properties for every cpu. -Bindings for CPU nodes follow the ePAPR standard, available from: - -http://devicetree.org - -For the ARM architecture every CPU node must contain the following properties: - -- device_type: must be "cpu" -- reg: property matching the CPU MPIDR[23:0] register bits - reg[31:24] bits must be set to 0 -- compatible: should be one of: - "arm,arm1020" - "arm,arm1020e" - "arm,arm1022" - "arm,arm1026" - "arm,arm720" - "arm,arm740" - "arm,arm7tdmi" - "arm,arm920" - "arm,arm922" - "arm,arm925" - "arm,arm926" - "arm,arm940" - "arm,arm946" - "arm,arm9tdmi" - "arm,cortex-a5" - "arm,cortex-a7" - "arm,cortex-a8" - "arm,cortex-a9" - "arm,cortex-a15" - "arm,arm1136" - "arm,arm1156" - "arm,arm1176" - "arm,arm11mpcore" - "faraday,fa526" - "intel,sa110" - "intel,sa1100" - "marvell,feroceon" - "marvell,mohawk" - "marvell,xsc3" - "marvell,xscale" - -Example: +Bindings for CPU nodes follow the ePAPR v1.1 standard, available from: + +https://www.power.org/documentation/epapr-version-1-1/ + +with updates for 32-bit and 64-bit ARM systems provided in this document. + +================================ +Convention used in this document +================================ + +This document follows the conventions described in the ePAPR v1.1, with +the addition: + +- square brackets define bitfields, eg reg[7:0] value of the bitfield in + the reg property contained in bits 7 down to 0 + +===================================== +cpus and cpu node bindings definition +===================================== + +The ARM architecture, in accordance with the ePAPR, requires the cpus and cpu +nodes to be present and contain the properties described below. + +- cpus node + + Description: Container of cpu nodes + + The node name must be "cpus". + + A cpus node must define the following properties: + + - #address-cells + Usage: required + Value type: <u32> + + Definition depends on ARM architecture version and + configuration: + + # On uniprocessor ARM architectures previous to v7 + value must be 1, to enable a simple enumeration + scheme for processors that do not have a HW CPU + identification register. + # On 32-bit ARM 11 MPcore, ARM v7 or later systems + value must be 1, that corresponds to CPUID/MPIDR + registers sizes. + # On ARM v8 64-bit systems value should be set to 2, + that corresponds to the MPIDR_EL1 register size. + If MPIDR_EL1[63:32] value is equal to 0 on all CPUs + in the system, #address-cells can be set to 1, since + MPIDR_EL1[63:32] bits are not used for CPUs + identification. + - #size-cells + Usage: required + Value type: <u32> + Definition: must be set to 0 + +- cpu node + + Description: Describes a CPU in an ARM based system + + PROPERTIES + + - device_type + Usage: required + Value type: <string> + Definition: must be "cpu" + - reg + Usage and definition depend on ARM architecture version and + configuration: + + # On uniprocessor ARM architectures previous to v7 + this property is required and must be set to 0. + + # On ARM 11 MPcore based systems this property is + required and matches the CPUID[11:0] register bits. + + Bits [11:0] in the reg cell must be set to + bits [11:0] in CPU ID register. + + All other bits in the reg cell must be set to 0. + + # On 32-bit ARM v7 or later systems this property is + required and matches the CPU MPIDR[23:0] register + bits. + + Bits [23:0] in the reg cell must be set to + bits [23:0] in MPIDR. + + All other bits in the reg cell must be set to 0. + + # On ARM v8 64-bit systems this property is required + and matches the MPIDR_EL1 register affinity bits. + + * If cpus node's #address-cells property is set to 2 + + The first reg cell bits [7:0] must be set to + bits [39:32] of MPIDR_EL1. + + The second reg cell bits [23:0] must be set to + bits [23:0] of MPIDR_EL1. + + * If cpus node's #address-cells property is set to 1 + + The reg cell bits [23:0] must be set to bits [23:0] + of MPIDR_EL1. + + All other bits in the reg cells must be set to 0. + + - compatible: + Usage: required + Value type: <string> + Definition: should be one of: + "arm,arm710t" + "arm,arm720t" + "arm,arm740t" + "arm,arm7ej-s" + "arm,arm7tdmi" + "arm,arm7tdmi-s" + "arm,arm9es" + "arm,arm9ej-s" + "arm,arm920t" + "arm,arm922t" + "arm,arm925" + "arm,arm926e-s" + "arm,arm926ej-s" + "arm,arm940t" + "arm,arm946e-s" + "arm,arm966e-s" + "arm,arm968e-s" + "arm,arm9tdmi" + "arm,arm1020e" + "arm,arm1020t" + "arm,arm1022e" + "arm,arm1026ej-s" + "arm,arm1136j-s" + "arm,arm1136jf-s" + "arm,arm1156t2-s" + "arm,arm1156t2f-s" + "arm,arm1176jzf" + "arm,arm1176jz-s" + "arm,arm1176jzf-s" + "arm,arm11mpcore" + "arm,cortex-a5" + "arm,cortex-a7" + "arm,cortex-a8" + "arm,cortex-a9" + "arm,cortex-a15" + "arm,cortex-a53" + "arm,cortex-a57" + "arm,cortex-m0" + "arm,cortex-m0+" + "arm,cortex-m1" + "arm,cortex-m3" + "arm,cortex-m4" + "arm,cortex-r4" + "arm,cortex-r5" + "arm,cortex-r7" + "faraday,fa526" + "intel,sa110" + "intel,sa1100" + "marvell,feroceon" + "marvell,mohawk" + "marvell,pj4a" + "marvell,pj4b" + "marvell,sheeva-v5" + "qcom,krait" + "qcom,scorpion" + - enable-method + Value type: <stringlist> + Usage and definition depend on ARM architecture version. + # On ARM v8 64-bit this property is required and must + be one of: + "spin-table" + "psci" + # On ARM 32-bit systems this property is optional. + + - cpu-release-addr + Usage: required for systems that have an "enable-method" + property value of "spin-table". + Value type: <prop-encoded-array> + Definition: + # On ARM v8 64-bit systems must be a two cell + property identifying a 64-bit zero-initialised + memory location. + +Example 1 (dual-cluster big.LITTLE system 32-bit): cpus { #size-cells = <0>; #address-cells = <1>; - CPU0: cpu@0 { + cpu@0 { device_type = "cpu"; compatible = "arm,cortex-a15"; reg = <0x0>; }; - CPU1: cpu@1 { + cpu@1 { device_type = "cpu"; compatible = "arm,cortex-a15"; reg = <0x1>; }; - CPU2: cpu@100 { + cpu@100 { device_type = "cpu"; compatible = "arm,cortex-a7"; reg = <0x100>; }; - CPU3: cpu@101 { + cpu@101 { device_type = "cpu"; compatible = "arm,cortex-a7"; reg = <0x101>; }; }; + +Example 2 (Cortex-A8 uniprocessor 32-bit system): + + cpus { + #size-cells = <0>; + #address-cells = <1>; + + cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a8"; + reg = <0x0>; + }; + }; + +Example 3 (ARM 926EJ-S uniprocessor 32-bit system): + + cpus { + #size-cells = <0>; + #address-cells = <1>; + + cpu@0 { + device_type = "cpu"; + compatible = "arm,arm926ej-s"; + reg = <0x0>; + }; + }; + +Example 4 (ARM Cortex-A57 64-bit system): + +cpus { + #size-cells = <0>; + #address-cells = <2>; + + cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x0>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x1>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x100>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x101>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@10000 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10000>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@10001 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10001>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@10100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10100>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@10101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x0 0x10101>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@100000000 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x0>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@100000001 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x1>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@100000100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x100>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@100000101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x101>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@100010000 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x10000>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@100010001 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x10001>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@100010100 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x10100>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; + + cpu@100010101 { + device_type = "cpu"; + compatible = "arm,cortex-a57"; + reg = <0x1 0x10101>; + enable-method = "spin-table"; + cpu-release-addr = <0 0x20000000>; + }; +}; diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt new file mode 100644 index 000000000000..4aa20e7a424e --- /dev/null +++ b/Documentation/devicetree/bindings/arm/topology.txt @@ -0,0 +1,474 @@ +=========================================== +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 ePAPR standard, available from: + +http://www.power.org/documentation/epapr-version-1-1/ + +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. +Any other configuration is consider 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.txt |