Documentation, dt, numa: dt bindings for NUMA.

Add DT bindings for numa mapping of memory, CPUs and IOs.

Reviewed-by: Robert Richter <rrichter@cavium.com>
Signed-off-by: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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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 - 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 - 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>;
+       };