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_main.c b/services/std_svc/psci/psci_main.c
index fcd3b55..b389287 100644
--- a/services/std_svc/psci/psci_main.c
+++ b/services/std_svc/psci/psci_main.c
@@ -31,9 +31,10 @@
#include <arch.h>
#include <arch_helpers.h>
#include <assert.h>
+#include <debug.h>
+#include <platform.h>
#include <runtime_svc.h>
#include <std_svc.h>
-#include <debug.h>
#include "psci_private.h"
/*******************************************************************************
@@ -167,6 +168,62 @@
return PSCI_E_SUCCESS;
}
+int psci_system_suspend(unsigned long entrypoint,
+ unsigned long context_id)
+{
+ int rc;
+ unsigned int power_state;
+ entry_point_info_t ep;
+
+ /* Validate the entrypoint using platform pm_ops */
+ if (psci_plat_pm_ops->validate_ns_entrypoint) {
+ rc = psci_plat_pm_ops->validate_ns_entrypoint(entrypoint);
+ if (rc != PSCI_E_SUCCESS) {
+ assert(rc == PSCI_E_INVALID_PARAMS);
+ return PSCI_E_INVALID_PARAMS;
+ }
+ }
+
+ /* Check if the current CPU is the last ON CPU in the system */
+ if (!psci_is_last_on_cpu())
+ return PSCI_E_DENIED;
+
+ /*
+ * Verify and derive the re-entry information for
+ * the non-secure world from the non-secure state from
+ * where this call originated.
+ */
+ rc = psci_get_ns_ep_info(&ep, entrypoint, context_id);
+ if (rc != PSCI_E_SUCCESS)
+ return rc;
+
+ /*
+ * Assert that the required pm_ops hook is implemented to ensure that
+ * the capability detected during psci_setup() is valid.
+ */
+ assert(psci_plat_pm_ops->get_sys_suspend_power_state);
+
+ /*
+ * Query the platform for the power_state required for system suspend
+ */
+ power_state = psci_plat_pm_ops->get_sys_suspend_power_state();
+
+ /* Save PSCI power state parameter for the core in suspend context */
+ psci_set_suspend_power_state(power_state);
+
+ /*
+ * Do what is needed to enter the power down state. Upon success,
+ * enter the final wfi which will power down this cpu.
+ */
+ psci_afflvl_suspend(&ep,
+ MPIDR_AFFLVL0,
+ PLATFORM_MAX_AFFLVL);
+
+ /* Reset PSCI power state parameter for the core. */
+ psci_set_suspend_power_state(PSCI_INVALID_DATA);
+ return PSCI_E_SUCCESS;
+}
+
int psci_cpu_off(void)
{
int rc;
@@ -357,6 +414,9 @@
case PSCI_MIG_INFO_UP_CPU_AARCH32:
SMC_RET1(handle, psci_migrate_info_up_cpu());
+ case PSCI_SYSTEM_SUSPEND_AARCH32:
+ SMC_RET1(handle, psci_system_suspend(x1, x2));
+
case PSCI_SYSTEM_OFF:
psci_system_off();
/* We should never return from psci_system_off() */
@@ -390,6 +450,9 @@
case PSCI_MIG_INFO_UP_CPU_AARCH64:
SMC_RET1(handle, psci_migrate_info_up_cpu());
+ case PSCI_SYSTEM_SUSPEND_AARCH64:
+ SMC_RET1(handle, psci_system_suspend(x1, x2));
+
default:
break;
}