+++ /dev/null
-==============================================================================
-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 - numa-node-id
-==============================================================================
-
-For the purpose of identification, each NUMA node is associated with a unique
-token known as a node id. For the purpose of this binding
-a node id is a 32-bit integer.
-
-A device node is associated with a NUMA node by the presence of a
-numa-node-id property which contains the node id of the device.
-
-Example:
- /* numa node 0 */
- numa-node-id = <0>;
-
- /* numa node 1 */
- numa-node-id = <1>;
-
-==============================================================================
-3 - distance-map
-==============================================================================
-
-The optional device tree node distance-map describes the relative
-distance (memory latency) between all numa nodes.
-
-- compatible : Should at least contain "numa-distance-map-v1".
-
-- distance-matrix
- This property defines a matrix to describe the relative distances
- between all numa nodes.
- It is represented as a list of node pairs and their relative distance.
-
- Note:
- 1. Each entry represents distance from first node to second node.
- The distances are equal in either direction.
- 2. The distance from a node to self (local distance) is represented
- with value 10 and all internode distance should be represented with
- a value greater than 10.
- 3. distance-matrix should have entries in lexicographical ascending
- order of nodes.
- 4. There must be only one device node distance-map which must
- reside in the root node.
- 5. If the distance-map node is not present, a default
- distance-matrix is used.
-
-Example:
- 4 nodes connected in mesh/ring topology as below,
-
- 0_______20______1
- | |
- | |
- 20 20
- | |
- | |
- |_______________|
- 3 20 2
-
- if relative distance for each hop is 20,
- then internode distance would be,
- 0 -> 1 = 20
- 1 -> 2 = 20
- 2 -> 3 = 20
- 3 -> 0 = 20
- 0 -> 2 = 40
- 1 -> 3 = 40
-
- and dt presentation for this distance matrix is,
-
- distance-map {
- compatible = "numa-distance-map-v1";
- distance-matrix = <0 0 10>,
- <0 1 20>,
- <0 2 40>,
- <0 3 20>,
- <1 0 20>,
- <1 1 10>,
- <1 2 20>,
- <1 3 40>,
- <2 0 40>,
- <2 1 20>,
- <2 2 10>,
- <2 3 20>,
- <3 0 20>,
- <3 1 40>,
- <3 2 20>,
- <3 3 10>;
- };
-
-==============================================================================
-4 - Empty memory nodes
-==============================================================================
-
-Empty memory nodes, which no memory resides in, are allowed. There are no
-device nodes for these empty memory nodes. However, the NUMA node IDs and
-distance maps are still valid and memory may be added into them through
-hotplug afterwards.
-
-Example:
-
- memory@0 {
- device_type = "memory";
- reg = <0x0 0x0 0x0 0x80000000>;
- numa-node-id = <0>;
- };
-
- memory@80000000 {
- device_type = "memory";
- reg = <0x0 0x80000000 0x0 0x80000000>;
- numa-node-id = <1>;
- };
-
- /* Empty memory node 2 and 3 */
- distance-map {
- compatible = "numa-distance-map-v1";
- distance-matrix = <0 0 10>,
- <0 1 20>,
- <0 2 40>,
- <0 3 20>,
- <1 0 20>,
- <1 1 10>,
- <1 2 20>,
- <1 3 40>,
- <2 0 40>,
- <2 1 20>,
- <2 2 10>,
- <2 3 20>,
- <3 0 20>,
- <3 1 40>,
- <3 2 20>,
- <3 3 10>;
- };
-
-==============================================================================
-5 - Example dts
-==============================================================================
-
-Dual socket system consists of 2 boards connected through ccn bus and
-each board having one socket/soc of 8 cpus, memory and pci bus.
-
- memory@c00000 {
- device_type = "memory";
- reg = <0x0 0xc00000 0x0 0x80000000>;
- /* node 0 */
- numa-node-id = <0>;
- };
-
- memory@10000000000 {
- device_type = "memory";
- reg = <0x100 0x0 0x0 0x80000000>;
- /* node 1 */
- numa-node-id = <1>;
- };
-
- cpus {
- #address-cells = <2>;
- #size-cells = <0>;
-
- cpu@0 {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0x0>;
- enable-method = "psci";
- /* node 0 */
- numa-node-id = <0>;
- };
- cpu@1 {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0x1>;
- enable-method = "psci";
- numa-node-id = <0>;
- };
- cpu@2 {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0x2>;
- enable-method = "psci";
- numa-node-id = <0>;
- };
- cpu@3 {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0x3>;
- enable-method = "psci";
- numa-node-id = <0>;
- };
- cpu@4 {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0x4>;
- enable-method = "psci";
- numa-node-id = <0>;
- };
- cpu@5 {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0x5>;
- enable-method = "psci";
- numa-node-id = <0>;
- };
- cpu@6 {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0x6>;
- enable-method = "psci";
- numa-node-id = <0>;
- };
- cpu@7 {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0x7>;
- enable-method = "psci";
- numa-node-id = <0>;
- };
- cpu@8 {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0x8>;
- enable-method = "psci";
- /* node 1 */
- numa-node-id = <1>;
- };
- cpu@9 {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0x9>;
- enable-method = "psci";
- numa-node-id = <1>;
- };
- cpu@a {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0xa>;
- enable-method = "psci";
- numa-node-id = <1>;
- };
- cpu@b {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0xb>;
- enable-method = "psci";
- numa-node-id = <1>;
- };
- cpu@c {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0xc>;
- enable-method = "psci";
- numa-node-id = <1>;
- };
- cpu@d {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0xd>;
- enable-method = "psci";
- numa-node-id = <1>;
- };
- cpu@e {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0xe>;
- enable-method = "psci";
- numa-node-id = <1>;
- };
- cpu@f {
- device_type = "cpu";
- compatible = "arm,armv8";
- reg = <0x0 0xf>;
- enable-method = "psci";
- numa-node-id = <1>;
- };
- };
-
- pcie0: pcie0@848000000000 {
- compatible = "arm,armv8";
- device_type = "pci";
- bus-range = <0 255>;
- #size-cells = <2>;
- #address-cells = <3>;
- reg = <0x8480 0x00000000 0 0x10000000>; /* Configuration space */
- ranges = <0x03000000 0x8010 0x00000000 0x8010 0x00000000 0x70 0x00000000>;
- /* node 0 */
- numa-node-id = <0>;
- };
-
- pcie1: pcie1@948000000000 {
- compatible = "arm,armv8";
- device_type = "pci";
- bus-range = <0 255>;
- #size-cells = <2>;
- #address-cells = <3>;
- reg = <0x9480 0x00000000 0 0x10000000>; /* Configuration space */
- ranges = <0x03000000 0x9010 0x00000000 0x9010 0x00000000 0x70 0x00000000>;
- /* node 1 */
- numa-node-id = <1>;
- };
-
- distance-map {
- compatible = "numa-distance-map-v1";
- distance-matrix = <0 0 10>,
- <0 1 20>,
- <1 1 10>;
- };
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