CSS: Implement support for NODE_HW_STATE
This patch implements CSS platform hook to support NODE_HW_STATE PSCI
API. The platform hook queries SCP to obtain CSS power state. Power
states returned by SCP are then converted to expected PSCI return codes.
Juno's PSCI operation structure is modified to use the CSS
implementation.
Change-Id: I4a5edac0e5895dd77b51398cbd78f934831dafc0
diff --git a/plat/arm/css/common/css_pm.c b/plat/arm/css/common/css_pm.c
index 801d937..7607f61 100644
--- a/plat/arm/css/common/css_pm.c
+++ b/plat/arm/css/common/css_pm.c
@@ -299,6 +299,43 @@
}
/*******************************************************************************
+ * Handler to query CPU/cluster power states from SCP
+ ******************************************************************************/
+int css_node_hw_state(u_register_t mpidr, unsigned int power_level)
+{
+ int rc, element;
+ unsigned int cpu_state, cluster_state;
+
+ /*
+ * The format of 'power_level' is implementation-defined, but 0 must
+ * mean a CPU. We also allow 1 to denote the cluster
+ */
+ if (power_level != ARM_PWR_LVL0 && power_level != ARM_PWR_LVL1)
+ return PSCI_E_INVALID_PARAMS;
+
+ /* Query SCP */
+ rc = scpi_get_css_power_state(mpidr, &cpu_state, &cluster_state);
+ if (rc != 0)
+ return PSCI_E_INVALID_PARAMS;
+
+ /* Map power states of CPU and cluster to expected PSCI return codes */
+ if (power_level == ARM_PWR_LVL0) {
+ /*
+ * The CPU state returned by SCP is an 8-bit bit mask
+ * corresponding to each CPU in the cluster
+ */
+ element = mpidr & MPIDR_AFFLVL_MASK;
+ return CSS_CPU_PWR_STATE(cpu_state, element) ==
+ CSS_CPU_PWR_STATE_ON ? HW_ON : HW_OFF;
+ } else {
+ assert(cluster_state == CSS_CLUSTER_PWR_STATE_ON ||
+ cluster_state == CSS_CLUSTER_PWR_STATE_OFF);
+ return cluster_state == CSS_CLUSTER_PWR_STATE_ON ? HW_ON :
+ HW_OFF;
+ }
+}
+
+/*******************************************************************************
* Export the platform handlers via plat_arm_psci_pm_ops. The ARM Standard
* platform will take care of registering the handlers with PSCI.
******************************************************************************/
@@ -312,5 +349,6 @@
.system_off = css_system_off,
.system_reset = css_system_reset,
.validate_power_state = arm_validate_power_state,
- .validate_ns_entrypoint = arm_validate_ns_entrypoint
+ .validate_ns_entrypoint = arm_validate_ns_entrypoint,
+ .get_node_hw_state = css_node_hw_state
};