On 10/14/2015 12:47 AM, Mark Rutland 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.
Cool, I think those bindings are quite extensible and easy understood.
Thanks
Hanjun
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