PSCI: Implement platform compatibility layer

The new PSCI topology framework and PSCI extended State framework introduces
a breaking change in the platform port APIs. To ease the migration of the
platform ports to the new porting interface, a compatibility layer is
introduced which essentially defines the new platform API in terms of the
old API. The old PSCI helpers to retrieve the power-state, its associated
fields and the highest coordinated physical OFF affinity level of a core
are also implemented for compatibility. This allows the existing
platform ports to work with the new PSCI framework without significant
rework. This layer will be enabled by default once the switch to the new
PSCI framework is done and is controlled by the build flag ENABLE_PLAT_COMPAT.

Change-Id: I4b17cac3a4f3375910a36dba6b03d8f1700d07e3

1 files changed, 78 insertions, 0 deletions

diff --git a/services/std_svc/psci1.0/psci_common.c b/services/std_svc/psci1.0/psci_common.c
index 0b885cde..7f1a5fd0 100644
--- a/services/std_svc/psci1.0/psci_common.c
+++ b/services/std_svc/psci1.0/psci_common.c
@@ -797,3 +797,81 @@ void psci_print_power_domain_map(void)
 	}
 #endif
 }
+
+#if ENABLE_PLAT_COMPAT
+/*******************************************************************************
+ * PSCI Compatibility helper function to return the 'power_state' parameter of
+ * the PSCI CPU SUSPEND request for the current CPU. Returns PSCI_INVALID_DATA
+ * if not invoked within CPU_SUSPEND for the current CPU.
+ ******************************************************************************/
+int psci_get_suspend_powerstate(void)
+{
+	/* Sanity check to verify that CPU is within CPU_SUSPEND */
+	if (psci_get_aff_info_state() == AFF_STATE_ON &&
+		!is_local_state_run(psci_get_cpu_local_state()))
+		return psci_power_state_compat[plat_my_core_pos()];
+
+	return PSCI_INVALID_DATA;
+}
+
+/*******************************************************************************
+ * PSCI Compatibility helper function to return the state id of the current
+ * cpu encoded in the 'power_state' parameter. Returns PSCI_INVALID_DATA
+ * if not invoked within CPU_SUSPEND for the current CPU.
+ ******************************************************************************/
+int psci_get_suspend_stateid(void)
+{
+	unsigned int power_state;
+	power_state = psci_get_suspend_powerstate();
+	if (power_state != PSCI_INVALID_DATA)
+		return psci_get_pstate_id(power_state);
+
+	return PSCI_INVALID_DATA;
+}
+
+/*******************************************************************************
+ * PSCI Compatibility helper function to return the state id encoded in the
+ * 'power_state' parameter of the CPU specified by 'mpidr'. Returns
+ * PSCI_INVALID_DATA if the CPU is not in CPU_SUSPEND.
+ ******************************************************************************/
+int psci_get_suspend_stateid_by_mpidr(unsigned long mpidr)
+{
+	int cpu_idx = plat_core_pos_by_mpidr(mpidr);
+
+	if (cpu_idx == -1)
+		return PSCI_INVALID_DATA;
+
+	/* Sanity check to verify that the CPU is in CPU_SUSPEND */
+	if (psci_get_aff_info_state_by_idx(cpu_idx) == AFF_STATE_ON &&
+		!is_local_state_run(psci_get_cpu_local_state_by_idx(cpu_idx)))
+		return psci_get_pstate_id(psci_power_state_compat[cpu_idx]);
+
+	return PSCI_INVALID_DATA;
+}
+
+/*******************************************************************************
+ * This function returns highest affinity level which is in OFF
+ * state. The affinity instance with which the level is associated is
+ * determined by the caller.
+ ******************************************************************************/
+unsigned int psci_get_max_phys_off_afflvl(void)
+{
+	psci_power_state_t state_info;
+
+	memset(&state_info, 0, sizeof(state_info));
+	psci_get_target_local_pwr_states(PLAT_MAX_PWR_LVL, &state_info);
+
+	return psci_find_target_suspend_lvl(&state_info);
+}
+
+/*******************************************************************************
+ * PSCI Compatibility helper function to return target affinity level requested
+ * for the CPU_SUSPEND. This function assumes affinity levels correspond to
+ * power domain levels on the platform.
+ ******************************************************************************/
+int psci_get_suspend_afflvl(void)
+{
+	return psci_get_suspend_pwrlvl();
+}
+
+#endif