diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index 4628a43..204ae4c 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -90,6 +90,11 @@
 $(eval $(call assert_boolean,ARM_BL31_IN_DRAM))
 $(eval $(call add_define,ARM_BL31_IN_DRAM))
 
+# Process ARM_PLAT_MT flag
+ARM_PLAT_MT			:=	0
+$(eval $(call assert_boolean,ARM_PLAT_MT))
+$(eval $(call add_define,ARM_PLAT_MT))
+
 # Enable PSCI_STAT_COUNT/RESIDENCY APIs on ARM platforms
 ENABLE_PSCI_STAT		:=	1
 ENABLE_PMF			:=	1
diff --git a/plat/arm/common/arm_topology.c b/plat/arm/common/arm_topology.c
index 4430b13..3c95263 100644
--- a/plat/arm/common/arm_topology.c
+++ b/plat/arm/common/arm_topology.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -40,14 +40,26 @@
 int arm_check_mpidr(u_register_t mpidr)
 {
 	unsigned int cluster_id, cpu_id;
+	uint64_t valid_mask;
 
-	mpidr &= MPIDR_AFFINITY_MASK;
-
-	if (mpidr & ~(MPIDR_CLUSTER_MASK | MPIDR_CPU_MASK))
-		return -1;
+#if ARM_PLAT_MT
+	unsigned int pe_id;
 
+	valid_mask = ~(MPIDR_AFFLVL_MASK |
+			(MPIDR_AFFLVL_MASK << MPIDR_AFF1_SHIFT) |
+			(MPIDR_AFFLVL_MASK << MPIDR_AFF2_SHIFT));
+	cluster_id = (mpidr >> MPIDR_AFF2_SHIFT) & MPIDR_AFFLVL_MASK;
+	cpu_id = (mpidr >> MPIDR_AFF1_SHIFT) & MPIDR_AFFLVL_MASK;
+	pe_id = (mpidr >> MPIDR_AFF0_SHIFT) & MPIDR_AFFLVL_MASK;
+#else
+	valid_mask = ~(MPIDR_CLUSTER_MASK | MPIDR_CPU_MASK);
 	cluster_id = (mpidr >> MPIDR_AFF1_SHIFT) & MPIDR_AFFLVL_MASK;
 	cpu_id = (mpidr >> MPIDR_AFF0_SHIFT) & MPIDR_AFFLVL_MASK;
+#endif /* ARM_PLAT_MT */
+
+	mpidr &= MPIDR_AFFINITY_MASK;
+	if (mpidr & valid_mask)
+		return -1;
 
 	if (cluster_id >= PLAT_ARM_CLUSTER_COUNT)
 		return -1;
@@ -57,5 +69,10 @@
 	if (cpu_id >= plat_arm_get_cluster_core_count(mpidr))
 		return -1;
 
+#if ARM_PLAT_MT
+	if (pe_id >= plat_arm_get_cpu_pe_count(mpidr))
+		return -1;
+#endif /* ARM_PLAT_MT */
+
 	return 0;
 }
diff --git a/plat/arm/css/common/css_topology.c b/plat/arm/css/common/css_topology.c
index d5f0275..9c86f89 100644
--- a/plat/arm/css/common/css_topology.c
+++ b/plat/arm/css/common/css_topology.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -30,6 +30,10 @@
 
 #include <plat_arm.h>
 
+#if ARM_PLAT_MT
+#pragma weak plat_arm_get_cpu_pe_count
+#endif
+
 /******************************************************************************
  * This function implements a part of the critical interface between the psci
  * generic layer and the platform that allows the former to query the platform
@@ -43,3 +47,14 @@
 
 	return -1;
 }
+
+#if ARM_PLAT_MT
+/******************************************************************************
+ * This function returns the PE count within the physical cpu corresponding to
+ * `mpidr`. Now one cpu only have one thread, so just return 1.
+ *****************************************************************************/
+unsigned int plat_arm_get_cpu_pe_count(u_register_t mpidr)
+{
+	return 1;
+}
+#endif /* ARM_PLAT_MT */
diff --git a/plat/arm/css/drivers/scpi/css_scpi.c b/plat/arm/css/drivers/scpi/css_scpi.c
index 65ae978..7c5c578 100644
--- a/plat/arm/css/drivers/scpi/css_scpi.c
+++ b/plat/arm/css/drivers/scpi/css_scpi.c
@@ -150,8 +150,18 @@
 	uint32_t state = 0;
 	uint32_t *payload_addr;
 
+#if ARM_PLAT_MT
+	/*
+	 * The current SCPI driver only caters for single-threaded platforms.
+	 * Hence we ignore the thread ID (which is always 0) for such platforms.
+	 */
+	state |= (mpidr >> MPIDR_AFF1_SHIFT) & 0x0f;	/* CPU ID */
+	state |= ((mpidr >> MPIDR_AFF2_SHIFT) & 0x0f) << 4;	/* Cluster ID */
+#else
 	state |= mpidr & 0x0f;	/* CPU ID */
 	state |= (mpidr & 0xf00) >> 4;	/* Cluster ID */
+#endif /* ARM_PLAT_MT */
+
 	state |= cpu_state << 8;
 	state |= cluster_state << 12;
 	state |= css_state << 16;