On Tue, Oct 13, 2015 at 10:17 PM, Mark Rutland <mark.rutland@xxxxxxx> wrote:
>> > Hi Mark,
>> >
>> > i am thinking, if we could not address(or becomes complex) these topologies
>> > using associativity,
>> > we should think of an alternate binding which suits existing and upcoming
>> > arm64 platforms.
>> > can we think of below numa binding which is inline with ACPI and will
>> > address all sort of topologies!
>> >
>> > i am proposing as below,
>> >
>> > 1. introduce "proximity" node property. this property will be
>> > present in dt nodes like memory, cpu, bus and devices(like associativity
>> > property) and
>> > will tell which numa node(proximity domain) this dt node belongs to.
>> >
>> > examples:
>> > cpu@000 {
>> > device_type = "cpu";
>> > compatible = "cavium,thunder", "arm,armv8";
>> > reg = <0x0 0x000>;
>> > enable-method = "psci";
>> > proximity = <0>;
>> > };
>> > cpu@001 {
>> > device_type = "cpu";
>> > compatible = "cavium,thunder", "arm,armv8";
>> > reg = <0x0 0x001>;
>> > enable-method = "psci";
>> > proximity = <1>;
>> > };
>> >
>> > memory@00000000 {
>> > device_type = "memory";
>> > reg = <0x0 0x01400000 0x3 0xFEC00000>;
>> > proximity =<0>;
>> >
>> > };
>> >
>> > memory@10000000000 {
>> > device_type = "memory";
>> > reg = <0x100 0x00400000 0x3 0xFFC00000>;
>> > proximity =<1>;
>> > };
>> >
>> > pcie0@0x8480,00000000 {
>> > compatible = "cavium,thunder-pcie";
>> > device_type = "pci";
>> > msi-parent = <&its>;
>> > bus-range = <0 255>;
>> > #size-cells = <2>;
>> > #address-cells = <3>;
>> > #stream-id-cells = <1>;
>> > reg = <0x8480 0x00000000 0 0x10000000>; /*Configuration
>> > space */
>> > ranges = <0x03000000 0x8010 0x00000000 0x8010 0x00000000
>> > 0x70 0x00000000>, /* mem ranges */
>> > <0x03000000 0x8300 0x00000000 0x8300 0x00000000
>> > 0x500 0x00000000>;
>> > proximity =<0>;
>> > };
>> >
>> >
>> > 2. Introduce new dt node "proximity-map" which will capture the NxN numa
>> > node distance matrix.
>> >
>> > for example, 4 nodes connected in mesh/ring structure as,
>> > A(0) <connected to> B(1) <connected to> C(2) <connected to> D(3) <connected
>> > to> A(1)
>> >
>> > relative distance would be,
>> > A -> B = 20
>> > B -> C = 20
>> > C -> D = 20
>> > D -> A = 20
>> > A -> C = 40
>> > B -> D = 40
>> >
>> > and dt presentation for this distance matrix is :
>> >
>> > proximity-map {
>> > node-count = <4>;
>> > 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>;
>> > }
>> >
>> > the entries like < 0 0 > < 1 1> < 2 2> < 3 3> can be optional and code can
>> > put default value(local distance).
>> > the entries like <1 0> can be optional if <0 1> and <1 0> are of same
>> > distance.
>> is this binding looks ok?
>
> This looks roughly requivalent to the ACPI SLIT, which means it's as
> powerful, which allays my previous concerns.
>
>> i can implement this and submit in next version of patchset.
>
> Please put together (plaintext) patches.
>
> Then we have a sensible baseline that we can work from; it's somewhat
> difficult for others to join the disacussion here as-is.
thanks, will post the v6 in couple of days with implementation based
on this binding proposal..
>
> Thanks,
> Mark.
thanks
Ganapat
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