[RFC PATCH 07/36] ACPI / PPTT: Find cache level by cache-id

[James Morse]

Hi Ben,

On 14/07/2025 12:42, Ben Horgan wrote:
> On 7/11/25 19:36, James Morse wrote:
>> The MPAM table identifies caches by id. The MPAM driver also wants to know
>> the cache level to determine if the platform is of the shape that can be
>> managed via resctrl. Cacheinfo has this information, but only for CPUs that
>> are online.
>>
>> Waiting for all CPUs to come online is a problem for platforms where
>> CPUs are brought online late by user-space.
>>
>> Add a helper that walks every possible cache, until it finds the one
>> identified by cache-id, then return the level.
>>
>> acpi_count_levels() expects its levels parameter to be initialised to
>> zero as it passes it to acpi_find_cache_level() as starting_level.
>> The existing callers do this. Document it.

> This paragraph is stale. You dealt with this in the previous commit.

Fixed, thanks.

James