diff --git a/include/plat/common/plat_drtm.h b/include/plat/common/plat_drtm.h
new file mode 100644
index 0000000..3c4e3d5
--- /dev/null
+++ b/include/plat/common/plat_drtm.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef PLAT_DRTM_H
+#define PLAT_DRTM_H
+
+/* platform-specific DMA protection functions */
+bool plat_has_non_host_platforms(void);
+bool plat_has_unmanaged_dma_peripherals(void);
+unsigned int plat_get_total_smmus(void);
+void plat_enumerate_smmus(const uintptr_t **smmus_out,
+			  size_t *smmu_count_out);
+
+#endif /* PLAT_DRTM_H */