diff --git a/plat/meson/gxbb/gxbb_topology.c b/plat/meson/gxbb/gxbb_topology.c
new file mode 100644
index 0000000..49bb2dc
--- /dev/null
+++ b/plat/meson/gxbb/gxbb_topology.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <platform_def.h>
+#include <stdint.h>
+
+#include "gxbb_private.h"
+
+/* The power domain tree descriptor */
+static unsigned char power_domain_tree_desc[] = {
+	/* Number of root nodes */
+	PLATFORM_CLUSTER_COUNT,
+	/* Number of children for the first node */
+	PLATFORM_CLUSTER0_CORE_COUNT
+};
+
+/*******************************************************************************
+ * This function returns the ARM default topology tree information.
+ ******************************************************************************/
+const unsigned char *plat_get_power_domain_tree_desc(void)
+{
+	return power_domain_tree_desc;
+}
+
+/*******************************************************************************
+ * 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
+ * to convert an MPIDR to a unique linear index. An error code (-1) is returned
+ * in case the MPIDR is invalid.
+ ******************************************************************************/
+int plat_core_pos_by_mpidr(u_register_t mpidr)
+{
+	unsigned int cluster_id, cpu_id;
+
+	mpidr &= MPIDR_AFFINITY_MASK;
+	if (mpidr & ~(MPIDR_CLUSTER_MASK | MPIDR_CPU_MASK))
+		return -1;
+
+	cluster_id = (mpidr >> MPIDR_AFF1_SHIFT) & MPIDR_AFFLVL_MASK;
+	cpu_id = (mpidr >> MPIDR_AFF0_SHIFT) & MPIDR_AFFLVL_MASK;
+
+	if (cluster_id >= PLATFORM_CLUSTER_COUNT)
+		return -1;
+
+	if (cpu_id >= PLATFORM_MAX_CPUS_PER_CLUSTER)
+		return -1;
+
+	return plat_gxbb_calc_core_pos(mpidr);
+}