arm64: kernel: add PM build infrastructure

This patch adds the required makefile and kconfig entries to enable PM
for arm64 systems.

The kernel relies on the cpu_{suspend}/{resume} infrastructure to
properly save the context for a CPU and put it to sleep, hence this
patch adds the config option required to enable cpu_{suspend}/{resume}
API.

In order to rely on the CPU PM implementation for saving and restoring
of CPU subsystems like GIC and PMU, the arch Kconfig must be also
augmented to select the CONFIG_CPU_PM option when SUSPEND or CPU_IDLE
kernel implementations are selected.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index baab4eb8bfe4..a1c8f39cb009 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -12,6 +12,7 @@ config ARM64
         select BUILDTIME_EXTABLE_SORT
         select CLONE_BACKWARDS
         select COMMON_CLK
+        select CPU_PM if (SUSPEND || CPU_IDLE)
         select GENERIC_CLOCKEVENTS
         select GENERIC_CLOCKEVENTS_BROADCAST if SMP
         select GENERIC_IOMAP
@@ -277,6 +278,18 @@ config SYSVIPC_COMPAT
 
 endmenu
 
+menu "Power management options"
+
+source "kernel/power/Kconfig"
+
+config ARCH_SUSPEND_POSSIBLE
+        def_bool y
+
+config ARM64_CPU_SUSPEND
+        def_bool PM_SLEEP
+
+endmenu
+
 source "net/Kconfig"
 
 source "drivers/Kconfig"