Re: [PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE

[Sudeep Holla]

On 10/05/16 01:02, Rafael J. Wysocki wrote:
> On Tuesday, April 19, 2016 01:30:09 PM Sudeep Holla wrote:
> > ACPI 6.0 adds a new method to specify the CPU idle states(C-states)
> > called Low Power Idle(LPI) states. Since new architectures like ARM64
> > use only LPIs, introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE to
> > encapsulate all the code supporting the old style C-states(_CST)
> >
> > This patch will help to extend the processor_idle module to support
> > LPI.
> >
> > Cc: x86@xxxxxxxxxx
> > Cc: linux-ia64@xxxxxxxxxxxxxxx
> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> > Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> > ---
> >   arch/ia64/Kconfig             |  1 +
> >   arch/x86/Kconfig              |  1 +
> >   drivers/acpi/Kconfig          |  3 ++
> >   drivers/acpi/processor_idle.c | 74 +++++++++++++++++++++++++++++--------------
> >   include/acpi/processor.h      |  3 +-
> >   5 files changed, 57 insertions(+), 25 deletions(-)
> >
> > diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
> > index b534ebab36ea..717de2a146e2 100644
> > --- a/arch/ia64/Kconfig
> > +++ b/arch/ia64/Kconfig
> > @@ -16,6 +16,7 @@ config IA64
> >   	select PCI if (!IA64_HP_SIM)
> >   	select ACPI if (!IA64_HP_SIM)
> >   	select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
> > +	select ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE if ACPI
> >   	select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
> >   	select HAVE_UNSTABLE_SCHED_CLOCK
> >   	select HAVE_IDE
> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > index 2dc18605831f..eb03fd0d63b9 100644
> > --- a/arch/x86/Kconfig
> > +++ b/arch/x86/Kconfig
> > @@ -37,6 +37,7 @@ config X86
> >   	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
> >   	select ARCH_MIGHT_HAVE_PC_PARPORT
> >   	select ARCH_MIGHT_HAVE_PC_SERIO
> > +	select ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE if ACPI
> >   	select ARCH_SUPPORTS_ATOMIC_RMW
> >   	select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
> >   	select ARCH_SUPPORTS_INT128		if X86_64
> > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> > index 82b96ee8624c..ec289078667c 100644
> > --- a/drivers/acpi/Kconfig
> > +++ b/drivers/acpi/Kconfig
> > @@ -48,6 +48,9 @@ config ACPI_LEGACY_TABLES_LOOKUP
> >   config ARCH_MIGHT_HAVE_ACPI_PDC
> >   	bool
> >
> > +config ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE
> > +	bool
>
> It might be better to do
>
> config ACPI_PROCESSOR_CST
> 	bool
> 	depends on ia64 || x86

Done

> Should it depend on ARCH_HAS_POWER_INIT too?

IIUC it's not defined for ia64, so better not to add that dependency
here IMO. include/acpi/processor.h encapsulates it. Let me know if I
have misunderstood it.

--
Regards,
Sudeep