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 */
diff --git a/include/plat/common/platform.h b/include/plat/common/platform.h
index da74624..58e08d4 100644
--- a/include/plat/common/platform.h
+++ b/include/plat/common/platform.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2022, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -20,6 +20,9 @@
 #include "plat_trng.h"
 #endif
 #include <drivers/fwu/fwu_metadata.h>
+#if DRTM_SUPPORT
+#include "plat_drtm.h"
+#endif /* DRTM_SUPPORT */
 
 /*******************************************************************************
  * Forward declarations