Introduce CONFIG_SUSPEND for suspend-to-Ram and standby

Introduce CONFIG_SUSPEND representing the ability to enter system sleep
states, such as the ACPI S3 state, and allow the user to choose SUSPEND
and HIBERNATION independently of each other.

Make HOTPLUG_CPU be selected automatically if SUSPEND or HIBERNATION has
been chosen and the kernel is intended for SMP systems.

Also, introduce CONFIG_PM_SLEEP which is automatically selected if
CONFIG_SUSPEND or CONFIG_HIBERNATION is set and use it to select the
code needed for both suspend and hibernation.

The top-level power management headers and the ACPI code related to
suspend and hibernation are modified to use the new definitions (the
changes in drivers/acpi/sleep/main.c are, mostly, moving code to reduce
the number of ifdefs).

There are many other files in which CONFIG_PM can be replaced with
CONFIG_PM_SLEEP or even with CONFIG_SUSPEND, but they can be updated in
the future.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index f85f77a538aa..777d37ae81a2 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -147,6 +147,10 @@ static inline void unregister_hotplug_dock_device(acpi_handle handle)
 /*--------------------------------------------------------------------------
                                   Suspend/Resume
   -------------------------------------------------------------------------- */
+#ifdef CONFIG_PM_SLEEP
 extern int acpi_sleep_init(void);
+#else
+static inline int acpi_sleep_init(void) { return 0; }
+#endif
 
 #endif /*__ACPI_DRIVERS_H__*/