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

On 10/05/16 01:02, Rafael J. Wysocki wrote:

On Tuesday, April 19, 2016 01:30:09 PM Sudeep Holla wrote:

quoted

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 at kernel.org
Cc: linux-ia64 at vger.kernel.org
Cc: "Rafael J. Wysocki" <redacted>
Signed-off-by: Sudeep Holla <redacted>
---
  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