Re: [PATCH RFC v3 08/11] ACPI: PPTT: Add acpi_pptt_get_cache_size_from_id helper

Reinette Chatre
2026-04-30T23:20:33Z

Hi Drew,

On 4/14/26 6:54 PM, Drew Fustini wrote:
> Add helper to look up a cache's size from its cache ID in the PPTT
> table. This is needed by the RISC-V RQSC parser to determine the cache
> size for CBQRI capacity controllers.
>
> The implementation follows the pattern established by
> find_acpi_cache_level_from_id() and acpi_pptt_get_cpumask_from_cache_id():
> uses acpi_get_pptt(), upgrade_pptt_cache(), checks all three cache types,
> and uses the do/while empty-detection loop.

I see how this helper is used to initialize cbqri_controller::cache::cache_size
but I am not able to determine where this value is used.
resctrl does need the cache size but it currently relies on struct cacheinfo returned
by the get_cpu_cacheinfo_level() helper to obtain it.

Reinette