DT bindings for numa map for memory, cores and IOs using arm,associativity device node property.
Signed-off-by: Ganapatrao Kulkarni <[email protected]> --- Documentation/devicetree/bindings/arm/numa.txt | 198 +++++++++++++++++++++++++ 1 file changed, 198 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/numa.txt diff --git a/Documentation/devicetree/bindings/arm/numa.txt b/Documentation/devicetree/bindings/arm/numa.txt new file mode 100644 index 0000000..4f51e25 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/numa.txt @@ -0,0 +1,198 @@ +============================================================================== +NUMA binding description. +============================================================================== + +============================================================================== +1 - Introduction +============================================================================== + +Systems employing a Non Uniform Memory Access (NUMA) architecture contain +collections of hardware resources including processors, memory, and I/O buses, +that comprise what is commonly known as a ???NUMA node???. +Processor accesses to memory within the local NUMA node is generally faster +than processor accesses to memory outside of the local NUMA node. +DT defines interfaces that allow the platform to convey NUMA node +topology information to OS. + +============================================================================== +2 - arm,associativity +============================================================================== + +The mapping is done using arm,associativity device property. +this property needs to be present in every device node which needs to to be +mapped to numa nodes. + +arm,associativity property is set of 32-bit integers. representing the +board id, socket id and core id. + +ex: + /* board 0, socket 0, core 0 */ + arm,associativity = <0 0 0x000>; + + /* board 1, socket 0, core 8 */ + arm,associativity = <1 0 0x08>; + +============================================================================== +3 - arm,associativity-reference-points +============================================================================== +This property is a set of 32-bit integers, each representing an index into +the arm,associativity nodes. The first integer is the most significant +NUMA boundary and the following are progressively less significant boundaries. +There can be more than one level of NUMA. + +Ex: + arm,associativity-reference-points = <0 1>; + The board Id(index 0) used first to calculate the associativity (node + distance), then follows the socket id(index 1). + + arm,associativity-reference-points = <1 0>; + The socket Id(index 1) used first to calculate the associativity, + then follows the board id(index 0). + + arm,associativity-reference-points = <0>; + Only the board Id(index 0) used to calculate the associativity. + + arm,associativity-reference-points = <1>; + Only socket Id(index 1) used to calculate the associativity. + +============================================================================== +4 - Example dts +============================================================================== + +Example: 2 Node system consists of 2 boards and each board having one socket +and 8 core in each socket. + + arm,associativity-reference-points = <0 1>; + + memory@00c00000 { + device_type = "memory"; + reg = <0x0 0x00c00000 0x0 0x80000000>; + /* board 0, socket 0, no specific core */ + arm,associativity = <0 0 0xffff>; + }; + + memory@10000000000 { + device_type = "memory"; + reg = <0x100 0x00000000 0x0 0x80000000>; + /* board 1, socket 0, no specific core */ + arm,associativity = <1 0 0xffff>; + }; + + cpus { + #address-cells = <2>; + #size-cells = <0>; + + cpu@000 { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x000>; + enable-method = "psci"; + /* board 0, socket 0, core 0*/ + arm,associativity = <0 0 0x000>; + }; + cpu@001 { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x001>; + enable-method = "psci"; + arm,associativity = <0 0 0x001>; + }; + cpu@002 { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x002>; + enable-method = "psci"; + arm,associativity = <0 0 0x002>; + }; + cpu@003 { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x003>; + enable-method = "psci"; + arm,associativity = <0 0 0x003>; + }; + cpu@004 { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x004>; + enable-method = "psci"; + arm,associativity = <0 0 0x004>; + }; + cpu@005 { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x005>; + enable-method = "psci"; + arm,associativity = <0 0 0x005>; + }; + cpu@006 { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x006>; + enable-method = "psci"; + arm,associativity = <0 0 0x006>; + }; + cpu@007 { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x007>; + enable-method = "psci"; + arm,associativity = <0 0 0x007>; + }; + cpu@008 { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x008>; + enable-method = "psci"; + /* board 1, socket 0, core 0*/ + arm,associativity = <1 0 0x008>; + }; + cpu@009 { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x009>; + enable-method = "psci"; + arm,associativity = <1 0 0x009>; + }; + cpu@00a { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x00a>; + enable-method = "psci"; + arm,associativity = <0 0 0x00a>; + }; + cpu@00b { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x00b>; + enable-method = "psci"; + arm,associativity = <1 0 0x00b>; + }; + cpu@00c { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x00c>; + enable-method = "psci"; + arm,associativity = <1 0 0x00c>; + }; + cpu@00d { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x00d>; + enable-method = "psci"; + arm,associativity = <1 0 0x00d>; + }; + cpu@00e { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x00e>; + enable-method = "psci"; + arm,associativity = <1 0 0x00e>; + }; + cpu@00f { + device_type = "cpu"; + compatible = "arm,armv8"; + reg = <0x0 0x00f>; + enable-method = "psci"; + arm,associativity = <1 0 0x00f>; + }; -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
