diff --git a/lib/psci/psci_main.c b/lib/psci/psci_main.c
index 5c0e952..52a8b8a 100644
--- a/lib/psci/psci_main.c
+++ b/lib/psci/psci_main.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -219,16 +219,19 @@
 int psci_affinity_info(u_register_t target_affinity,
 		       unsigned int lowest_affinity_level)
 {
-	int target_idx;
+	int ret;
+	unsigned int target_idx;
 
 	/* We dont support level higher than PSCI_CPU_PWR_LVL */
 	if (lowest_affinity_level > PSCI_CPU_PWR_LVL)
 		return PSCI_E_INVALID_PARAMS;
 
 	/* Calculate the cpu index of the target */
-	target_idx = plat_core_pos_by_mpidr(target_affinity);
-	if (target_idx == -1)
+	ret = plat_core_pos_by_mpidr(target_affinity);
+	if (ret == -1) {
 		return PSCI_E_INVALID_PARAMS;
+	}
+	target_idx = (unsigned int)ret;
 
 	/*
 	 * Generic management:
@@ -245,7 +248,7 @@
 	 * 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);
 
 	return psci_get_aff_info_state_by_idx(target_idx);
diff --git a/lib/psci/psci_off.c b/lib/psci/psci_off.c
index e8cd8fe..5447045 100644
--- a/lib/psci/psci_off.c
+++ b/lib/psci/psci_off.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -43,7 +43,7 @@
 int psci_do_cpu_off(unsigned int end_pwrlvl)
 {
 	int rc = PSCI_E_SUCCESS;
-	int idx = (int) plat_my_core_pos();
+	unsigned int idx = plat_my_core_pos();
 	psci_power_state_t state_info;
 	unsigned int parent_nodes[PLAT_MAX_PWR_LVL] = {0};
 
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
diff --git a/lib/psci/psci_private.h b/lib/psci/psci_private.h
index 0f25e65..e2dcfa8 100644
--- a/lib/psci/psci_private.h
+++ b/lib/psci/psci_private.h
@@ -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
  */
@@ -301,7 +301,7 @@
 int psci_cpu_on_start(u_register_t target_cpu,
 		      const entry_point_info_t *ep);
 
-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);
 
 /* Private exported functions from psci_off.c */
 int psci_do_cpu_off(unsigned int end_pwrlvl);
@@ -312,7 +312,7 @@
 			psci_power_state_t *state_info,
 			unsigned int is_power_down_state);
 
-void psci_cpu_suspend_finish(int cpu_idx, const psci_power_state_t *state_info);
+void psci_cpu_suspend_finish(unsigned int cpu_idx, const psci_power_state_t *state_info);
 
 /* Private exported functions from psci_helpers.S */
 void psci_do_pwrdown_cache_maintenance(unsigned int pwr_level);
diff --git a/lib/psci/psci_setup.c b/lib/psci/psci_setup.c
index becb547..d1ec998 100644
--- a/lib/psci/psci_setup.c
+++ b/lib/psci/psci_setup.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
  */
@@ -91,9 +91,9 @@
 
 	for (cpu_idx = 0; cpu_idx < psci_plat_core_count; cpu_idx++) {
 		psci_get_parent_pwr_domain_nodes(cpu_idx,
-						 (unsigned int)PLAT_MAX_PWR_LVL,
+						 PLAT_MAX_PWR_LVL,
 						 temp_index);
-		for (j = (int) PLAT_MAX_PWR_LVL - 1; j >= 0; j--) {
+		for (j = (int)PLAT_MAX_PWR_LVL - 1; j >= 0; j--) {
 			if (temp_index[j] != nodes_idx[j]) {
 				nodes_idx[j] = temp_index[j];
 				psci_non_cpu_pd_nodes[nodes_idx[j]].cpu_start_idx
@@ -115,8 +115,8 @@
 {
 	unsigned int i, j = 0U, num_nodes_at_lvl = 1U, num_nodes_at_next_lvl;
 	unsigned int node_index = 0U, num_children;
-	int parent_node_index = 0;
-	int level = (int) PLAT_MAX_PWR_LVL;
+	unsigned int parent_node_index = 0U;
+	int level = (int)PLAT_MAX_PWR_LVL;
 
 	/*
 	 * For each level the inputs are:
@@ -145,8 +145,8 @@
 			for (j = node_index;
 				j < (node_index + num_children); j++)
 				psci_init_pwr_domain_node((unsigned char)j,
-							  parent_node_index - 1,
-							  (unsigned char)level);
+						  parent_node_index - 1U,
+						  (unsigned char)level);
 
 			node_index = j;
 			num_nodes_at_next_lvl += num_children;
@@ -162,7 +162,7 @@
 	}
 
 	/* Validate the sanity of array exported by the platform */
-	assert(j <= (unsigned int)PLATFORM_CORE_COUNT);
+	assert(j <= PLATFORM_CORE_COUNT);
 	return j;
 }
 
diff --git a/lib/psci/psci_stat.c b/lib/psci/psci_stat.c
index 772a184..ecef95a 100644
--- a/lib/psci/psci_stat.c
+++ b/lib/psci/psci_stat.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -28,7 +28,7 @@
  * that goes to power down in non cpu power domains.
  */
 static int last_cpu_in_non_cpu_pd[PSCI_NUM_NON_CPU_PWR_DOMAINS] = {
-		[0 ... PSCI_NUM_NON_CPU_PWR_DOMAINS - 1] = -1};
+		[0 ... PSCI_NUM_NON_CPU_PWR_DOMAINS - 1U] = -1};
 
 /*
  * Following are used to store PSCI STAT values for
@@ -77,7 +77,7 @@
 			const psci_power_state_t *state_info)
 {
 	unsigned int lvl, parent_idx;
-	int cpu_idx = (int) plat_my_core_pos();
+	unsigned int cpu_idx = plat_my_core_pos();
 
 	assert(end_pwrlvl <= PLAT_MAX_PWR_LVL);
 	assert(state_info != NULL);
@@ -94,7 +94,7 @@
 		 * The power domain is entering a low power state, so this is
 		 * the last CPU for this power domain
 		 */
-		last_cpu_in_non_cpu_pd[parent_idx] = cpu_idx;
+		last_cpu_in_non_cpu_pd[parent_idx] = (int)cpu_idx;
 
 		parent_idx = psci_non_cpu_pd_nodes[parent_idx].parent_node;
 	}
@@ -110,7 +110,7 @@
 			const psci_power_state_t *state_info)
 {
 	unsigned int lvl, parent_idx;
-	int cpu_idx = (int) plat_my_core_pos();
+	unsigned int cpu_idx = plat_my_core_pos();
 	int stat_idx;
 	plat_local_state_t local_state;
 	u_register_t residency;
@@ -150,7 +150,7 @@
 
 		/* Call into platform interface to calculate residency. */
 		residency = plat_psci_stat_get_residency(lvl, state_info,
-					last_cpu_in_non_cpu_pd[parent_idx]);
+			(unsigned int)last_cpu_in_non_cpu_pd[parent_idx]);
 
 		/* Initialize back to reset value */
 		last_cpu_in_non_cpu_pd[parent_idx] = -1;
diff --git a/lib/psci/psci_suspend.c b/lib/psci/psci_suspend.c
index 98dd2d6..da9f328 100644
--- a/lib/psci/psci_suspend.c
+++ b/lib/psci/psci_suspend.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
  */
@@ -25,7 +25,7 @@
  * This function does generic and platform specific operations after a wake-up
  * from standby/retention states at multiple power levels.
  ******************************************************************************/
-static void psci_suspend_to_standby_finisher(int cpu_idx,
+static void psci_suspend_to_standby_finisher(unsigned int cpu_idx,
 					     unsigned int end_pwrlvl)
 {
 	unsigned int parent_nodes[PLAT_MAX_PWR_LVL] = {0};
@@ -157,7 +157,7 @@
 			    unsigned int is_power_down_state)
 {
 	int skip_wfi = 0;
-	int idx = (int) plat_my_core_pos();
+	unsigned int idx = plat_my_core_pos();
 	unsigned int parent_nodes[PLAT_MAX_PWR_LVL] = {0};
 
 	/*
@@ -276,7 +276,7 @@
  * 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_suspend_finish(int cpu_idx, const psci_power_state_t *state_info)
+void psci_cpu_suspend_finish(unsigned int cpu_idx, const psci_power_state_t *state_info)
 {
 	unsigned int counter_freq;
 	unsigned int max_off_lvl;