Re: [PATCH v5 2/9] ACPI/PPTT: Add Processor Properties Topology Table parsing

Rafael J. Wysocki
2017-12-12T01:11:00Z

On Friday, December 1, 2017 11:23:23 PM CET Jeremy Linton wrote:
> ACPI 6.2 adds a new table, which describes how processing units
> are related to each other in tree like fashion. Caches are
> also sprinkled throughout the tree and describe the properties
> of the caches in relation to other caches and processing units.
>
> Add the code to parse the cache hierarchy and report the total
> number of levels of cache for a given core using
> acpi_find_last_cache_level() as well as fill out the individual
> cores cache information with cache_setup_acpi() once the
> cpu_cacheinfo structure has been populated by the arch specific
> code.
>
> An additional patch later in the set adds the ability to report
> peers in the topology using find_acpi_cpu_topology()
> to report a unique ID for each processing unit at a given level
> in the tree. These unique id's can then be used to match related
> processing units which exist as threads, COD (clusters
> on die), within a given package, etc.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>

This is only going to be used by ARM64 for the time being, so I need
someone from that camp to review this.

Sudeep, Hanjun, Lorenzo?

Thanks,
Rafael