diff --git a/include/services/ffa_svc.h b/include/services/ffa_svc.h
index 9a7c489..ff1e04a 100644
--- a/include/services/ffa_svc.h
+++ b/include/services/ffa_svc.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2021, Arm Limited. All rights reserved.
+ * Copyright (c) 2020-2022, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,6 +7,8 @@
 #ifndef FFA_SVC_H
 #define FFA_SVC_H
 
+#include <stdbool.h>
+
 #include <lib/smccc.h>
 #include <lib/utils_def.h>
 #include <tools_share/uuid.h>
@@ -176,6 +178,15 @@
 #define FFA_ENDPOINT_ID_MAX			U(1 << 16)
 
 /*
+ * Reserve endpoint id for the SPMD.
+ */
+#define SPMD_DIRECT_MSG_ENDPOINT_ID		U(FFA_ENDPOINT_ID_MAX - 1)
+
+/* Mask and shift to check valid secure FF-A Endpoint ID. */
+#define SPMC_SECURE_ID_MASK			U(1)
+#define SPMC_SECURE_ID_SHIFT			U(15)
+
+/*
  * Mask for source and destination endpoint id in
  * a direct message request/response.
  */
@@ -209,4 +220,24 @@
 		FFA_DIRECT_MSG_ENDPOINT_ID_MASK;
 }
 
+/******************************************************************************
+ * FF-A helper functions to determine partition ID world.
+ *****************************************************************************/
+
+/*
+ * Determine if provided ID is in the secure world.
+ */
+static inline bool ffa_is_secure_world_id(uint16_t id)
+{
+	return ((id >> SPMC_SECURE_ID_SHIFT) & SPMC_SECURE_ID_MASK) == 1;
+}
+
+/*
+ * Determine if provided ID is in the normal world.
+ */
+static inline bool ffa_is_normal_world_id(uint16_t id)
+{
+	return !ffa_is_secure_world_id(id);
+}
+
 #endif /* FFA_SVC_H */