diff --git a/xen/arch/arm/platforms/seattle.c b/xen/arch/arm/platforms/seattle.c
index 86dce91..679632d 100644
--- a/xen/arch/arm/platforms/seattle.c
+++ b/xen/arch/arm/platforms/seattle.c
@@ -19,6 +19,7 @@
 
 #include <asm/platform.h>
 #include <asm/psci.h>
+#include <asm/vsmc.h>
 
 static const char * const seattle_dt_compat[] __initconst =
 {
@@ -33,12 +34,12 @@ static const char * const seattle_dt_compat[] __initconst =
  */
 static void seattle_system_reset(void)
 {
-    call_smc(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
+    call_smc(PSCI_0_2_FN32(PSCI_0_2_FUNC_SYSTEM_RESET), 0, 0, 0);
 }
 
 static void seattle_system_off(void)
 {
-    call_smc(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
+    call_smc(PSCI_0_2_FN32(PSCI_0_2_FUNC_SYSTEM_OFF), 0, 0, 0);
 }
 
 PLATFORM_START(seattle, "SEATTLE")
diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
index 34ee97e..4b01131 100644
--- a/xen/arch/arm/psci.c
+++ b/xen/arch/arm/psci.c
@@ -31,9 +31,9 @@
  * (native-width) function ID.
  */
 #ifdef CONFIG_ARM_64
-#define PSCI_0_2_FN_NATIVE(name)	PSCI_0_2_FN64_##name
+#define PSCI_0_2_FN_NATIVE(n)   PSCI_0_2_FN64(n)
 #else
-#define PSCI_0_2_FN_NATIVE(name)	PSCI_0_2_FN_##name
+#define PSCI_0_2_FN_NATIVE(n)   PSCI_0_2_FN32(n)
 #endif
 
 uint32_t psci_ver;
@@ -48,13 +48,13 @@ int call_psci_cpu_on(int cpu)
 void call_psci_system_off(void)
 {
     if ( psci_ver > PSCI_VERSION(0, 1) )
-        call_smc(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
+        call_smc(PSCI_0_2_FN32(PSCI_0_2_FUNC_SYSTEM_OFF), 0, 0, 0);
 }
 
 void call_psci_system_reset(void)
 {
     if ( psci_ver > PSCI_VERSION(0, 1) )
-        call_smc(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
+        call_smc(PSCI_0_2_FN32(PSCI_0_2_FUNC_SYSTEM_RESET), 0, 0, 0);
 }
 
 int __init psci_is_smc_method(const struct dt_device_node *psci)
@@ -144,7 +144,7 @@ int __init psci_init_0_2(void)
         }
     }
 
-    psci_ver = call_smc(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
+    psci_ver = call_smc(PSCI_0_2_FN32(PSCI_0_2_FUNC_PSCI_VERSION), 0, 0, 0);
 
     /* For the moment, we only support PSCI 0.2 and PSCI 1.x */
     if ( psci_ver != PSCI_VERSION(0, 2) && PSCI_VERSION_MAJOR(psci_ver) != 1 )
@@ -154,7 +154,7 @@ int __init psci_init_0_2(void)
         return -EOPNOTSUPP;
     }
 
-    psci_cpu_on_nr = PSCI_0_2_FN_NATIVE(CPU_ON);
+    psci_cpu_on_nr = PSCI_0_2_FN_NATIVE(PSCI_0_2_FUNC_CPU_ON);
 
     printk(XENLOG_INFO "Using PSCI-%u.%u for SMP bringup\n",
            PSCI_VERSION_MAJOR(psci_ver), PSCI_VERSION_MINOR(psci_ver));
diff --git a/xen/arch/arm/vsmc.c b/xen/arch/arm/vsmc.c
index 718b30f..ea86eea 100644
--- a/xen/arch/arm/vsmc.c
+++ b/xen/arch/arm/vsmc.c
@@ -87,7 +87,9 @@ static bool handle_arch(struct cpu_user_regs *regs)
 /* helper function for checking arm mode 32/64 bit */
 static inline int psci_mode_check(struct domain *d, register_t fid)
 {
-    return !( is_64bit_domain(d)^( (fid & PSCI_0_2_64BIT) >> 30 ) );
+    return !( is_64bit_domain(d)^
+              ((fid & (ARM_SMCCC_SMC_64 << ARM_SMCCC_CALL_CONV_SHIFT)) >>
+               ARM_SMCCC_CALL_CONV_SHIFT) );
 }
 
 /* PSCI 2.0 interface */
@@ -97,34 +99,34 @@ static bool handle_ssc(struct cpu_user_regs *regs)
 
     switch ( ARM_SMCCC_FUNC_NUM(fid) )
     {
-    case ARM_SMCCC_FUNC_NUM(PSCI_0_2_FN_PSCI_VERSION):
+    case PSCI_0_2_FUNC_PSCI_VERSION:
         perfc_incr(vpsci_version);
         PSCI_SET_RESULT(regs, do_psci_0_2_version());
         return true;
-    case ARM_SMCCC_FUNC_NUM(PSCI_0_2_FN_CPU_OFF):
+    case PSCI_0_2_FUNC_CPU_OFF:
         perfc_incr(vpsci_cpu_off);
         PSCI_SET_RESULT(regs, do_psci_0_2_cpu_off());
         return true;
-    case ARM_SMCCC_FUNC_NUM(PSCI_0_2_FN_MIGRATE_INFO_TYPE):
+    case PSCI_0_2_FUNC_MIGRATE_INFO_TYPE:
         perfc_incr(vpsci_migrate_info_type);
         PSCI_SET_RESULT(regs, do_psci_0_2_migrate_info_type());
         return true;
-    case ARM_SMCCC_FUNC_NUM(PSCI_0_2_FN_MIGRATE_INFO_UP_CPU):
+    case PSCI_0_2_FUNC_MIGRATE_INFO_UP_CPU:
         perfc_incr(vpsci_migrate_info_up_cpu);
         if ( psci_mode_check(current->domain, fid) )
             PSCI_SET_RESULT(regs, do_psci_0_2_migrate_info_up_cpu());
         return true;
-    case ARM_SMCCC_FUNC_NUM(PSCI_0_2_FN_SYSTEM_OFF):
+    case PSCI_0_2_FUNC_SYSTEM_OFF:
         perfc_incr(vpsci_system_off);
         do_psci_0_2_system_off();
         PSCI_SET_RESULT(regs, PSCI_INTERNAL_FAILURE);
-        return true;
-    case ARM_SMCCC_FUNC_NUM(PSCI_0_2_FN_SYSTEM_RESET):
+       return true;
+    case PSCI_0_2_FUNC_SYSTEM_RESET:
         perfc_incr(vpsci_system_reset);
         do_psci_0_2_system_reset();
         PSCI_SET_RESULT(regs, PSCI_INTERNAL_FAILURE);
         return true;
-    case ARM_SMCCC_FUNC_NUM(PSCI_0_2_FN_CPU_ON):
+    case PSCI_0_2_FUNC_CPU_ON:
         perfc_incr(vpsci_cpu_on);
         if ( psci_mode_check(current->domain, fid) )
         {
@@ -134,7 +136,7 @@ static bool handle_ssc(struct cpu_user_regs *regs)
             PSCI_SET_RESULT(regs, do_psci_0_2_cpu_on(vcpuid, epoint, cid));
         }
         return true;
-    case ARM_SMCCC_FUNC_NUM(PSCI_0_2_FN_CPU_SUSPEND):
+    case PSCI_0_2_FUNC_CPU_SUSPEND:
         perfc_incr(vpsci_cpu_suspend);
         if ( psci_mode_check(current->domain, fid) )
         {
@@ -144,7 +146,7 @@ static bool handle_ssc(struct cpu_user_regs *regs)
             PSCI_SET_RESULT(regs, do_psci_0_2_cpu_suspend(pstate, epoint, cid));
         }
         return true;
-    case ARM_SMCCC_FUNC_NUM(PSCI_0_2_FN_AFFINITY_INFO):
+    case PSCI_0_2_FUNC_AFFINITY_INFO:
         perfc_incr(vpsci_cpu_affinity_info);
         if ( psci_mode_check(current->domain, fid) )
         {
@@ -153,7 +155,7 @@ static bool handle_ssc(struct cpu_user_regs *regs)
             PSCI_SET_RESULT(regs, do_psci_0_2_affinity_info(taff, laff));
         }
         return true;
-    case ARM_SMCCC_FUNC_NUM(PSCI_0_2_FN_MIGRATE):
+    case PSCI_0_2_FUNC_MIGRATE:
         perfc_incr(vpsci_cpu_migrate);
         if ( psci_mode_check(current->domain, fid) )
         {
diff --git a/xen/include/asm-arm/psci.h b/xen/include/asm-arm/psci.h
index be2458a..af6edf8 100644
--- a/xen/include/asm-arm/psci.h
+++ b/xen/include/asm-arm/psci.h
@@ -1,6 +1,8 @@
 #ifndef __ASM_PSCI_H__
 #define __ASM_PSCI_H__
 
+#include <asm/vsmc.h>
+
 /* PSCI return values (inclusive of all PSCI versions) */
 #define PSCI_SUCCESS                 0
 #define PSCI_NOT_SUPPORTED          -1
@@ -41,30 +43,23 @@ register_t do_psci_0_2_migrate_info_up_cpu(void);
 void do_psci_0_2_system_off(void);
 void do_psci_0_2_system_reset(void);
 
-/* PSCI v0.2 interface */
-#define PSCI_0_2_FN_BASE        0x84000000
-#define PSCI_0_2_FN(n)          (PSCI_0_2_FN_BASE + (n))
-#define PSCI_0_2_64BIT          0x40000000
-#define PSCI_0_2_FN64_BASE      \
-                        (PSCI_0_2_FN_BASE + PSCI_0_2_64BIT)
-#define PSCI_0_2_FN64(n)        (PSCI_0_2_FN64_BASE + (n))
-
-#define PSCI_0_2_FN_PSCI_VERSION        PSCI_0_2_FN(0)
-#define PSCI_0_2_FN_CPU_SUSPEND         PSCI_0_2_FN(1)
-#define PSCI_0_2_FN_CPU_OFF             PSCI_0_2_FN(2)
-#define PSCI_0_2_FN_CPU_ON              PSCI_0_2_FN(3)
-#define PSCI_0_2_FN_AFFINITY_INFO       PSCI_0_2_FN(4)
-#define PSCI_0_2_FN_MIGRATE             PSCI_0_2_FN(5)
-#define PSCI_0_2_FN_MIGRATE_INFO_TYPE   PSCI_0_2_FN(6)
-#define PSCI_0_2_FN_MIGRATE_INFO_UP_CPU PSCI_0_2_FN(7)
-#define PSCI_0_2_FN_SYSTEM_OFF          PSCI_0_2_FN(8)
-#define PSCI_0_2_FN_SYSTEM_RESET        PSCI_0_2_FN(9)
+#define PSCI_0_2_FN32(n) ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,                \
+                                            ARM_SMCCC_SMC_32,                   \
+                                            ARM_SMCCC_OWNER_STANDARD, n)
+#define PSCI_0_2_FN64(n) ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,                \
+                                            ARM_SMCCC_SMC_64,                   \
+                                            ARM_SMCCC_OWNER_STANDARD, n)
 
-#define PSCI_0_2_FN64_CPU_SUSPEND       PSCI_0_2_FN64(1)
-#define PSCI_0_2_FN64_CPU_ON            PSCI_0_2_FN64(3)
-#define PSCI_0_2_FN64_AFFINITY_INFO     PSCI_0_2_FN64(4)
-#define PSCI_0_2_FN64_MIGRATE           PSCI_0_2_FN64(5)
-#define PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU   PSCI_0_2_FN64(7)
+#define PSCI_0_2_FUNC_PSCI_VERSION        0
+#define PSCI_0_2_FUNC_CPU_SUSPEND         1
+#define PSCI_0_2_FUNC_CPU_OFF             2
+#define PSCI_0_2_FUNC_CPU_ON              3
+#define PSCI_0_2_FUNC_AFFINITY_INFO       4
+#define PSCI_0_2_FUNC_MIGRATE             5
+#define PSCI_0_2_FUNC_MIGRATE_INFO_TYPE   6
+#define PSCI_0_2_FUNC_MIGRATE_INFO_UP_CPU 7
+#define PSCI_0_2_FUNC_SYSTEM_OFF          8
+#define PSCI_0_2_FUNC_SYSTEM_RESET        9
 
 /* PSCI v0.2 affinity level state returned by AFFINITY_INFO */
 #define PSCI_0_2_AFFINITY_LEVEL_ON      0
