1 files changed, 39 insertions, 0 deletions
diff --git a/plat/layerscape/common/ls_topology.c b/plat/layerscape/common/ls_topology.c
new file mode 100644
index 00000000..5b76087d
--- /dev/null
+++ b/plat/layerscape/common/ls_topology.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include "plat_ls.h"
+
+/*******************************************************************************
+ * This function validates an MPIDR by checking whether it falls within the
+ * acceptable bounds. An error code (-1) is returned if an incorrect mpidr
+ * is passed.
+ ******************************************************************************/
+int ls_check_mpidr(u_register_t mpidr)
+{
+	unsigned int cluster_id, cpu_id;
+	uint64_t valid_mask;
+
+	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;
+
+	mpidr &= MPIDR_AFFINITY_MASK;
+	if (mpidr & valid_mask)
+		return -1;
+
+	if (cluster_id >= PLAT_LS_CLUSTER_COUNT)
+		return -1;
+
+	/*
+	 * Validate cpu_id by checking whether it represents a CPU in
+	 * one of the two clusters present on the platform.
+	 */
+	if (cpu_id >= plat_ls_get_cluster_core_count(mpidr))
+		return -1;
+
+
+	return 0;
+}