Documentation: arm64/arm: dt bindings for numa.

DT bindings for numa map for memory, cores and IOs using
arm,associativity device node property.

Signed-off-by: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Signed-off-by: Vadim Lomovtsev <Vadim.Lomovtsev@caviumnetworks.com>

diff --git a/Documentation/devicetree/bindings/arm/numa.txt b/Documentation/devicetree/bindings/arm/numa.txt
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+==============================================================================
+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 which defines level of
+topology and boundary in the system at which a significant difference in
+performance can be measured between cross-device accesses within
+a single location and those spanning multiple locations.
+The first cell always contains the broadest subdivision within the system,
+while the last cell enumerates the individual devices, such as an SMT thread
+of a CPU, or a bus bridge within an SoC".
+
+ex:
+       /* board 0, socket 0, cluster 0, core 0  thread 0 */
+       arm,associativity = <0 0 0 0 0>;
+
+==============================================================================
+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>;
+
+       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 0>;
+               };
+               cpu@001 {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x001>;
+                       enable-method = "psci";
+                       arm,associativity = <0 0 1>;
+               };
+               cpu@002 {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x002>;
+                       enable-method = "psci";
+                       arm,associativity = <0 0 2>;
+               };
+               cpu@003 {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x003>;
+                       enable-method = "psci";
+                       arm,associativity = <0 0 3>;
+               };
+               cpu@004 {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x004>;
+                       enable-method = "psci";
+                       arm,associativity = <0 0 4>;
+               };
+               cpu@005 {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x005>;
+                       enable-method = "psci";
+                       arm,associativity = <0 0 5>;
+               };
+               cpu@006 {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x006>;
+                       enable-method = "psci";
+                       arm,associativity = <0 0 6>;
+               };
+               cpu@007 {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x007>;
+                       enable-method = "psci";
+                       arm,associativity = <0 0 7>;
+               };
+               cpu@008 {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x008>;
+                       enable-method = "psci";
+                       /* board 1, socket 0, core 0*/
+                       arm,associativity = <1 0 0>;
+               };
+               cpu@009 {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x009>;
+                       enable-method = "psci";
+                       arm,associativity = <1 0 1>;
+               };
+               cpu@00a {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x00a>;
+                       enable-method = "psci";
+                       arm,associativity = <0 0 2>;
+               };
+               cpu@00b {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x00b>;
+                       enable-method = "psci";
+                       arm,associativity = <1 0 3>;
+               };
+               cpu@00c {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x00c>;
+                       enable-method = "psci";
+                       arm,associativity = <1 0 4>;
+               };
+               cpu@00d {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x00d>;
+                       enable-method = "psci";
+                       arm,associativity = <1 0 5>;
+               };
+               cpu@00e {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x00e>;
+                       enable-method = "psci";
+                       arm,associativity = <1 0 6>;
+               };
+               cpu@00f {
+                       device_type = "cpu";
+                       compatible =  "arm,armv8";
+                       reg = <0x0 0x00f>;
+                       enable-method = "psci";
+                       arm,associativity = <1 0 7>;
+               };
+       };
+
+       pcie0: pcie0@0x8480,00000000 {
+               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>; /* mem ranges */
+               /* board 0, socket 0, pci bus 0*/
+               arm,associativity = <0 0 0>;
+        };