diff --git a/lib/psci/psci_on.c b/lib/psci/psci_on.c
index 470b4f3..dd48e10 100644
--- a/lib/psci/psci_on.c
+++ b/lib/psci/psci_on.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -20,12 +20,12 @@
 /*
  * Helper functions for the CPU level spinlocks
  */
-static inline void psci_spin_lock_cpu(int idx)
+static inline void psci_spin_lock_cpu(unsigned int idx)
 {
 	spin_lock(&psci_cpu_pd_nodes[idx].cpu_lock);
 }
 
-static inline void psci_spin_unlock_cpu(int idx)
+static inline void psci_spin_unlock_cpu(unsigned int idx)
 {
 	spin_unlock(&psci_cpu_pd_nodes[idx].cpu_lock);
 }
@@ -61,12 +61,14 @@
 {
 	int rc;
 	aff_info_state_t target_aff_state;
-	int target_idx = plat_core_pos_by_mpidr(target_cpu);
+	int ret = plat_core_pos_by_mpidr(target_cpu);
+	unsigned int target_idx = (unsigned int)ret;
 
 	/* Calling function must supply valid input arguments */
-	assert(target_idx >= 0);
+	assert(ret >= 0);
 	assert(ep != NULL);
 
+
 	/*
 	 * This function must only be called on platforms where the
 	 * CPU_ON platform hooks have been implemented.
@@ -93,7 +95,7 @@
 	 * target CPUs shutdown was not seen by the current CPU's cluster. And
 	 * so the cache may contain stale data for the target CPU.
 	 */
-	flush_cpu_data_by_index((unsigned int)target_idx,
+	flush_cpu_data_by_index(target_idx,
 				psci_svc_cpu_data.aff_info_state);
 	rc = cpu_on_validate_state(psci_get_aff_info_state_by_idx(target_idx));
 	if (rc != PSCI_E_SUCCESS)
@@ -113,7 +115,7 @@
 	 * turned OFF.
 	 */
 	psci_set_aff_info_state_by_idx(target_idx, AFF_STATE_ON_PENDING);
-	flush_cpu_data_by_index((unsigned int)target_idx,
+	flush_cpu_data_by_index(target_idx,
 				psci_svc_cpu_data.aff_info_state);
 
 	/*
@@ -126,7 +128,7 @@
 	if (target_aff_state != AFF_STATE_ON_PENDING) {
 		assert(target_aff_state == AFF_STATE_OFF);
 		psci_set_aff_info_state_by_idx(target_idx, AFF_STATE_ON_PENDING);
-		flush_cpu_data_by_index((unsigned int)target_idx,
+		flush_cpu_data_by_index(target_idx,
 					psci_svc_cpu_data.aff_info_state);
 
 		assert(psci_get_aff_info_state_by_idx(target_idx) ==
@@ -146,11 +148,11 @@
 
 	if (rc == PSCI_E_SUCCESS)
 		/* Store the re-entry information for the non-secure world. */
-		cm_init_context_by_index((unsigned int)target_idx, ep);
+		cm_init_context_by_index(target_idx, ep);
 	else {
 		/* Restore the state on error. */
 		psci_set_aff_info_state_by_idx(target_idx, AFF_STATE_OFF);
-		flush_cpu_data_by_index((unsigned int)target_idx,
+		flush_cpu_data_by_index(target_idx,
 					psci_svc_cpu_data.aff_info_state);
 	}
 
@@ -164,7 +166,7 @@
  * are called by the common finisher routine in psci_common.c. The `state_info`
  * is the psci_power_state from which this CPU has woken up from.
  ******************************************************************************/
-void psci_cpu_on_finish(int cpu_idx, const psci_power_state_t *state_info)
+void psci_cpu_on_finish(unsigned int cpu_idx, const psci_power_state_t *state_info)
 {
 	/*
 	 * Plat. management: Perform the platform specific actions