Hi Sudeep,

On Tuesday 21 Jun 2022 at 20:20:14 (+0100), Sudeep Holla wrote:

Hi All,

This version updates cacheinfo to populate and use the information from
there for all the cache topology.

This series intends to fix some discrepancies we have in the CPU topology
parsing from the device tree /cpu-map node. Also this diverges from the
behaviour on a ACPI enabled platform. The expectation is that both DT
and ACPI enabled systems must present consistent view of the CPU topology.

Currently we assign generated cluster count as the physical package identifier
for each CPU which is wrong. The device tree bindings for CPU topology supports
sockets to infer the socket or physical package identifier for a given CPU.
Also we don't check if all the cores/threads belong to the same cluster before
updating their sibling masks which is fine as we don't set the cluster id yet.

These changes also assigns the cluster identifier as parsed from the device tree
cluster nodes within /cpu-map without support for nesting of the clusters.
Finally, it also add support for socket nodes in /cpu-map. With this the
parsing of exact same information from ACPI PPTT and /cpu-map DT node
aligns well.

The only exception is that the last level cache id information can be
inferred from the same ACPI PPTT while we need to parse CPU cache nodes
in the device tree.

Hi Greg,

I had not cc-ed you on earlier 3 versions as we had some disagreement
amongst Arm developers which we have not settled. Let me know how you want to

s/not/now :)

merge this once you agree with the changes. I can set pull request if
you prefer. Let me know.

v4[3]->v4:
	- Updated ACPI PPTT fw_token to use table offset instead of virtual
	  address as it could get changed for everytime it is mapped before
	  the global acpi_permanent_mmap is set
	- Added warning for the topology with nested clusters
	- Added update to cpu_clustergroup_mask so that introduction of
	  correct cluster_id doesn't break existing platforms by limiting
	  the span of clustergroup_mask(by Ionela)

I've tested v4 on quite a few platforms:
 - DT: Juno R0, DB845c, RB5
 - ACPI: TX2, Ampere Altra, Kunpeng920

and it all looks good from my point of view (topology and sched domain
hierarchy).

So for the full set (after the changes requested for 16/20 and 20/20):

Tested-by: Ionela Voinescu <redacted>

Hope it helps,
Ionela.

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