PSCI: Add SYSTEM_SUSPEND API support
This patch adds support for SYSTEM_SUSPEND API as mentioned in the PSCI 1.0
specification. This API, on being invoked on the last running core on a
supported platform, will put the system into a low power mode with memory
retention.
The psci_afflvl_suspend() internal API has been reused as most of the actions
to suspend a system are the same as invoking the PSCI CPU_SUSPEND API with the
target affinity level as 'system'. This API needs the 'power state' parameter
for the target low power state. This parameter is not passed by the caller of
the SYSTEM_SUSPEND API. Hence, the platform needs to implement the
get_sys_suspend_power_state() platform function to provide this information.
Also, the platform also needs to add support for suspending the system to the
existing 'plat_pm_ops' functions: affinst_suspend() and
affinst_suspend_finish().
Change-Id: Ib6bf10809cb4e9b92f463755608889aedd83cef5
diff --git a/services/std_svc/psci/psci_common.c b/services/std_svc/psci/psci_common.c
index 237cf1e..e401609 100644
--- a/services/std_svc/psci/psci_common.c
+++ b/services/std_svc/psci/psci_common.c
@@ -92,6 +92,38 @@
}
/*******************************************************************************
+ * This function verifies that the all the other cores in the system have been
+ * turned OFF and the current CPU is the last running CPU in the system.
+ * Returns 1 (true) if the current CPU is the last ON CPU or 0 (false)
+ * otherwise.
+ ******************************************************************************/
+unsigned int psci_is_last_on_cpu(void)
+{
+ unsigned long mpidr = read_mpidr_el1() & MPIDR_AFFINITY_MASK;
+ unsigned int i;
+
+ for (i = psci_aff_limits[MPIDR_AFFLVL0].min;
+ i <= psci_aff_limits[MPIDR_AFFLVL0].max; i++) {
+
+ assert(psci_aff_map[i].level == MPIDR_AFFLVL0);
+
+ if (!(psci_aff_map[i].state & PSCI_AFF_PRESENT))
+ continue;
+
+ if (psci_aff_map[i].mpidr == mpidr) {
+ assert(psci_get_state(&psci_aff_map[i])
+ == PSCI_STATE_ON);
+ continue;
+ }
+
+ if (psci_get_state(&psci_aff_map[i]) != PSCI_STATE_OFF)
+ return 0;
+ }
+
+ return 1;
+}
+
+/*******************************************************************************
* This function saves the highest affinity level which is in OFF state. The
* affinity instance with which the level is associated is determined by the
* caller.