1 files changed, 58 insertions, 0 deletions
diff --git a/plat/arm/common/arm_topology.c b/plat/arm/common/arm_topology.c
new file mode 100644
index 0000000..c9993a7
--- /dev/null
+++ b/plat/arm/common/arm_topology.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <platform_def.h>
+
+#include <arch.h>
+#include <plat/arm/common/plat_arm.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 arm_check_mpidr(u_register_t mpidr)
+{
+	unsigned int cluster_id, cpu_id;
+	uint64_t valid_mask;
+
+#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) |
+			(MPIDR_AFFLVL_MASK << MPIDR_AFF3_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 = (unsigned int) ((mpidr >> MPIDR_AFF1_SHIFT) &
+						MPIDR_AFFLVL_MASK);
+	cpu_id = (unsigned int) ((mpidr >> MPIDR_AFF0_SHIFT) &
+						MPIDR_AFFLVL_MASK);
+#endif /* ARM_PLAT_MT */
+
+	mpidr &= MPIDR_AFFINITY_MASK;
+	if ((mpidr & valid_mask) != 0U)
+		return -1;
+
+	if (cluster_id >= PLAT_ARM_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_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;
+}