Re: [PATCH 1/3] ACPI: CPPC: Add get the highest perf register value support

[Tony W Wang-oc]

On 2024/1/18 06:07, Ricardo Neri wrote:
> [这封邮件来自外部发件人]
>
> On Thu, Dec 28, 2023 at 03:57:03PM +0800, Tony W Wang-oc wrote:
> > Add function cppc_get_highest_perf in generic CPPC driver to get the
> > highest perf register value for specified core.
> >
> > Signed-off-by: Tony W Wang-oc <TonyWWang-oc@xxxxxxxxxxx>
> > ---
> >   drivers/acpi/cppc_acpi.c | 13 +++++++++++++
> >   include/acpi/cppc_acpi.h |  5 +++++
> >   2 files changed, 18 insertions(+)
> >
> > diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> > index 7ff269a78c20..1a77c514d007 100644
> > --- a/drivers/acpi/cppc_acpi.c
> > +++ b/drivers/acpi/cppc_acpi.c
> > @@ -1154,6 +1154,19 @@ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf)
> >        return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf);
> >   }
> >
> > +/**
> > + * cppc_get_highest_perf - Get the highest performance register value.
> > + * @cpunum: CPU from which to get highest performance.
> > + * @highest_perf: Return address.
> > + *
> > + * Return: 0 for success, -EIO otherwise.
> > + */
> > +int cppc_get_highest_perf(int cpunum, u64 *highest_perf)
> > +{
> > +     return cppc_get_perf(cpunum, HIGHEST_PERF, highest_perf);
> > +}
> > +EXPORT_SYMBOL_GPL(cppc_get_highest_perf);
> The Intel P-State driver uses cppc_get_perf_caps(). You would not need to
> export this function.
>
> Having said that, the Intel P-State driver could also use this new
> function, IMO. AFAICS, it does not *have* to use cppc_get_perf_caps().

Yes, you are right.