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

Drew Fustini
2026-05-01T16:53:40Z

On Thu, Apr 30, 2026 at 04:20:23PM -0700, Reinette Chatre wrote:
> 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

I will drop this patch and try get_cpu_cacheinfo_level() once I have
moved domain creation to the cpu online/offline handlers.

Thanks,
Drew