diff --git a/services/spd/opteed/opteed_main.c b/services/spd/opteed/opteed_main.c
index a9e4ece..ac58e04 100644
--- a/services/spd/opteed/opteed_main.c
+++ b/services/spd/opteed/opteed_main.c
@@ -187,14 +187,14 @@
  * state. Lastly it will also return any information that OPTEE needs to do
  * the work assigned to it.
  ******************************************************************************/
-static uint64_t opteed_smc_handler(uint32_t smc_fid,
-			 uint64_t x1,
-			 uint64_t x2,
-			 uint64_t x3,
-			 uint64_t x4,
+static uintptr_t opteed_smc_handler(uint32_t smc_fid,
+			 u_register_t x1,
+			 u_register_t x2,
+			 u_register_t x3,
+			 u_register_t x4,
 			 void *cookie,
 			 void *handle,
-			 uint64_t flags)
+			 u_register_t flags)
 {
 	cpu_context_t *ns_cpu_context;
 	uint32_t linear_id = plat_my_core_pos();
diff --git a/services/spd/opteed/opteed_pm.c b/services/spd/opteed/opteed_pm.c
index 2420b1e..7efc234 100644
--- a/services/spd/opteed/opteed_pm.c
+++ b/services/spd/opteed/opteed_pm.c
@@ -16,7 +16,7 @@
  * The target cpu is being turned on. Allow the OPTEED/OPTEE to perform any
  * actions needed. Nothing at the moment.
  ******************************************************************************/
-static void opteed_cpu_on_handler(uint64_t target_cpu)
+static void opteed_cpu_on_handler(u_register_t target_cpu)
 {
 }
 
@@ -24,7 +24,7 @@
  * This cpu is being turned off. Allow the OPTEED/OPTEE to perform any actions
  * needed
  ******************************************************************************/
-static int32_t opteed_cpu_off_handler(uint64_t unused)
+static int32_t opteed_cpu_off_handler(u_register_t unused)
 {
 	int32_t rc = 0;
 	uint32_t linear_id = plat_my_core_pos();
@@ -57,7 +57,7 @@
  * This cpu is being suspended. S-EL1 state must have been saved in the
  * resident cpu (mpidr format) if it is a UP/UP migratable OPTEE.
  ******************************************************************************/
-static void opteed_cpu_suspend_handler(uint64_t max_off_pwrlvl)
+static void opteed_cpu_suspend_handler(u_register_t max_off_pwrlvl)
 {
 	int32_t rc = 0;
 	uint32_t linear_id = plat_my_core_pos();
@@ -87,7 +87,7 @@
  * after initialising minimal architectural state that guarantees safe
  * execution.
  ******************************************************************************/
-static void opteed_cpu_on_finish_handler(uint64_t unused)
+static void opteed_cpu_on_finish_handler(u_register_t unused)
 {
 	int32_t rc = 0;
 	uint32_t linear_id = plat_my_core_pos();
@@ -123,7 +123,7 @@
  * completed the preceding suspend call. Use that context to program an entry
  * into OPTEE to allow it to do any remaining book keeping
  ******************************************************************************/
-static void opteed_cpu_suspend_finish_handler(uint64_t max_off_pwrlvl)
+static void opteed_cpu_suspend_finish_handler(u_register_t max_off_pwrlvl)
 {
 	int32_t rc = 0;
 	uint32_t linear_id = plat_my_core_pos();
@@ -154,7 +154,7 @@
  * Return the type of OPTEE the OPTEED is dealing with. Report the current
  * resident cpu (mpidr format) if it is a UP/UP migratable OPTEE.
  ******************************************************************************/
-static int32_t opteed_cpu_migrate_info(uint64_t *resident_cpu)
+static int32_t opteed_cpu_migrate_info(u_register_t *resident_cpu)
 {
 	return OPTEE_MIGRATE_INFO;
 }
diff --git a/services/spd/tlkd/tlkd_main.c b/services/spd/tlkd/tlkd_main.c
index 961fd18..5090f06 100644
--- a/services/spd/tlkd/tlkd_main.c
+++ b/services/spd/tlkd/tlkd_main.c
@@ -133,14 +133,14 @@
  * will also return any information that the secure payload needs to do the
  * work assigned to it.
  ******************************************************************************/
-static uint64_t tlkd_smc_handler(uint32_t smc_fid,
-			 uint64_t x1,
-			 uint64_t x2,
-			 uint64_t x3,
-			 uint64_t x4,
+static uintptr_t tlkd_smc_handler(uint32_t smc_fid,
+			 u_register_t x1,
+			 u_register_t x2,
+			 u_register_t x3,
+			 u_register_t x4,
 			 void *cookie,
 			 void *handle,
-			 uint64_t flags)
+			 u_register_t flags)
 {
 	cpu_context_t *ns_cpu_context;
 	gp_regs_t *gp_regs;
diff --git a/services/spd/tlkd/tlkd_pm.c b/services/spd/tlkd/tlkd_pm.c
index 8b4c457..2cd2fbb 100644
--- a/services/spd/tlkd/tlkd_pm.c
+++ b/services/spd/tlkd/tlkd_pm.c
@@ -22,7 +22,7 @@
  * Return the type of payload TLKD is dealing with. Report the current
  * resident cpu (mpidr format) if it is a UP/UP migratable payload.
  ******************************************************************************/
-static int32_t cpu_migrate_info(uint64_t *resident_cpu)
+static int32_t cpu_migrate_info(u_register_t *resident_cpu)
 {
 	/* the payload runs only on CPU0 */
 	*resident_cpu = MPIDR_CPU0;
@@ -35,7 +35,7 @@
  * This cpu is being suspended. Inform TLK of the SYSTEM_SUSPEND event, so
  * that it can pass this information to its Trusted Apps.
  ******************************************************************************/
-static void cpu_suspend_handler(uint64_t suspend_level)
+static void cpu_suspend_handler(u_register_t suspend_level)
 {
 	gp_regs_t *gp_regs;
 	int cpu = read_mpidr() & MPIDR_CPU_MASK;
@@ -67,7 +67,7 @@
  * This cpu is being resumed. Inform TLK of the SYSTEM_SUSPEND exit, so
  * that it can pass this information to its Trusted Apps.
  ******************************************************************************/
-static void cpu_resume_handler(uint64_t suspend_level)
+static void cpu_resume_handler(u_register_t suspend_level)
 {
 	gp_regs_t *gp_regs;
 	int cpu = read_mpidr() & MPIDR_CPU_MASK;
diff --git a/services/spd/trusty/trusty.c b/services/spd/trusty/trusty.c
index f5501c9..48a2611 100644
--- a/services/spd/trusty/trusty.c
+++ b/services/spd/trusty/trusty.c
@@ -212,14 +212,14 @@
 	SMC_RET0(handle);
 }
 
-static uint64_t trusty_smc_handler(uint32_t smc_fid,
-			 uint64_t x1,
-			 uint64_t x2,
-			 uint64_t x3,
-			 uint64_t x4,
+static uintptr_t trusty_smc_handler(uint32_t smc_fid,
+			 u_register_t x1,
+			 u_register_t x2,
+			 u_register_t x3,
+			 u_register_t x4,
 			 void *cookie,
 			 void *handle,
-			 uint64_t flags)
+			 u_register_t flags)
 {
 	struct args ret;
 	uint32_t vmid = 0;
@@ -347,14 +347,14 @@
 	}
 }
 
-static int32_t trusty_cpu_off_handler(uint64_t unused)
+static int32_t trusty_cpu_off_handler(u_register_t unused)
 {
 	trusty_cpu_suspend(1);
 
 	return 0;
 }
 
-static void trusty_cpu_on_finish_handler(uint64_t unused)
+static void trusty_cpu_on_finish_handler(u_register_t unused)
 {
 	struct trusty_cpu_ctx *ctx = get_trusty_ctx();
 
@@ -365,12 +365,12 @@
 	}
 }
 
-static void trusty_cpu_suspend_handler(uint64_t unused)
+static void trusty_cpu_suspend_handler(u_register_t unused)
 {
 	trusty_cpu_suspend(0);
 }
 
-static void trusty_cpu_suspend_finish_handler(uint64_t unused)
+static void trusty_cpu_suspend_finish_handler(u_register_t unused)
 {
 	trusty_cpu_resume(0);
 }
diff --git a/services/spd/tspd/tspd_main.c b/services/spd/tspd/tspd_main.c
index 279da98..8cb23b9 100644
--- a/services/spd/tspd/tspd_main.c
+++ b/services/spd/tspd/tspd_main.c
@@ -273,14 +273,14 @@
  * will also return any information that the secure payload needs to do the
  * work assigned to it.
  ******************************************************************************/
-static uint64_t tspd_smc_handler(uint32_t smc_fid,
-			 uint64_t x1,
-			 uint64_t x2,
-			 uint64_t x3,
-			 uint64_t x4,
+static uintptr_t tspd_smc_handler(uint32_t smc_fid,
+			 u_register_t x1,
+			 u_register_t x2,
+			 u_register_t x3,
+			 u_register_t x4,
 			 void *cookie,
 			 void *handle,
-			 uint64_t flags)
+			 u_register_t flags)
 {
 	cpu_context_t *ns_cpu_context;
 	uint32_t linear_id = plat_my_core_pos(), ns;
diff --git a/services/spd/tspd/tspd_pm.c b/services/spd/tspd/tspd_pm.c
index 5fdd3dc..9414c15 100644
--- a/services/spd/tspd/tspd_pm.c
+++ b/services/spd/tspd/tspd_pm.c
@@ -17,7 +17,7 @@
  * The target cpu is being turned on. Allow the TSPD/TSP to perform any actions
  * needed. Nothing at the moment.
  ******************************************************************************/
-static void tspd_cpu_on_handler(uint64_t target_cpu)
+static void tspd_cpu_on_handler(u_register_t target_cpu)
 {
 }
 
@@ -25,7 +25,7 @@
  * This cpu is being turned off. Allow the TSPD/TSP to perform any actions
  * needed
  ******************************************************************************/
-static int32_t tspd_cpu_off_handler(uint64_t unused)
+static int32_t tspd_cpu_off_handler(u_register_t unused)
 {
 	int32_t rc = 0;
 	uint32_t linear_id = plat_my_core_pos();
@@ -64,7 +64,7 @@
  * This cpu is being suspended. S-EL1 state must have been saved in the
  * resident cpu (mpidr format) if it is a UP/UP migratable TSP.
  ******************************************************************************/
-static void tspd_cpu_suspend_handler(uint64_t max_off_pwrlvl)
+static void tspd_cpu_suspend_handler(u_register_t max_off_pwrlvl)
 {
 	int32_t rc = 0;
 	uint32_t linear_id = plat_my_core_pos();
@@ -100,7 +100,7 @@
  * after initialising minimal architectural state that guarantees safe
  * execution.
  ******************************************************************************/
-static void tspd_cpu_on_finish_handler(uint64_t unused)
+static void tspd_cpu_on_finish_handler(u_register_t unused)
 {
 	int32_t rc = 0;
 	uint32_t linear_id = plat_my_core_pos();
@@ -145,7 +145,7 @@
  * completed the preceding suspend call. Use that context to program an entry
  * into the TSP to allow it to do any remaining book keeping
  ******************************************************************************/
-static void tspd_cpu_suspend_finish_handler(uint64_t max_off_pwrlvl)
+static void tspd_cpu_suspend_finish_handler(u_register_t max_off_pwrlvl)
 {
 	int32_t rc = 0;
 	uint32_t linear_id = plat_my_core_pos();
@@ -176,7 +176,7 @@
  * Return the type of TSP the TSPD is dealing with. Report the current resident
  * cpu (mpidr format) if it is a UP/UP migratable TSP.
  ******************************************************************************/
-static int32_t tspd_cpu_migrate_info(uint64_t *resident_cpu)
+static int32_t tspd_cpu_migrate_info(u_register_t *resident_cpu)
 {
 	return TSP_MIGRATE_INFO;
 }