diff --git a/services/spd/tlkd/tlkd_main.c b/services/spd/tlkd/tlkd_main.c
index bea4c48..c22203b 100644
--- a/services/spd/tlkd/tlkd_main.c
+++ b/services/spd/tlkd/tlkd_main.c
@@ -193,6 +193,10 @@
 	/* Passing a NULL context is a critical programming error */
 	assert(handle);
 
+	/* These SMCs are only supported by CPU0 */
+	if ((read_mpidr() & MPIDR_CPU_MASK) != 0)
+		SMC_RET1(handle, SMC_UNK);
+
 	/* Determine which security state this SMC originated from */
 	ns = is_caller_non_secure(flags);
 
@@ -267,9 +271,16 @@
 	 * b. register shared memory with the SP for passing args
 	 *    required for maintaining sessions with the Trusted
 	 *    Applications.
+	 * c. open/close sessions
+	 * d. issue commands to the Trusted Apps
 	 */
 	case TLK_REGISTER_LOGBUF:
 	case TLK_REGISTER_REQBUF:
+	case TLK_OPEN_TA_SESSION:
+	case TLK_CLOSE_TA_SESSION:
+	case TLK_TA_LAUNCH_OP:
+	case TLK_TA_SEND_EVENT:
+
 		if (!ns || !tlk_args_results_buf)
 			SMC_RET1(handle, SMC_UNK);
 
@@ -442,3 +453,25 @@
 	NULL,
 	tlkd_smc_handler
 );
+
+/* Define a SPD runtime service descriptor for fast SMC calls */
+DECLARE_RT_SVC(
+	tlkd_tap_fast,
+
+	OEN_TAP_START,
+	OEN_TAP_END,
+	SMC_TYPE_FAST,
+	NULL,
+	tlkd_smc_handler
+);
+
+/* Define a SPD runtime service descriptor for standard SMC calls */
+DECLARE_RT_SVC(
+	tlkd_tap_std,
+
+	OEN_TAP_START,
+	OEN_TAP_END,
+	SMC_TYPE_STD,
+	NULL,
+	tlkd_smc_handler
+);