score: More robust _SMP_Multicast_action()

If the caller already disabled interrupts, then do not disable thread
dispatching.  Calling _SMP_Multicast_action() with interrupts disabled
is a questionable use case.

cpukit/score/src/smpmulticastaction.c

@@ -218,6 +218,7 @@ void _SMP_Multicast_action(
   Per_CPU_Jobs     jobs;
   uint32_t         cpu_max;
   Per_CPU_Control *cpu_self;
+  uint32_t         isr_level;
 
   cpu_max = _SMP_Get_processor_maximum();
   _Assert( cpu_max <= CPU_MAXIMUM_PROCESSORS );
@@ -228,9 +229,18 @@ void _SMP_Multicast_action(
 
   jobs.handler = handler;
   jobs.arg = arg;
+  isr_level = _ISR_Get_level();
+
+  if ( isr_level == 0 ) {
+    cpu_self = _Thread_Dispatch_disable();
+  } else {
+    cpu_self = _Per_CPU_Get();
+  }
 
-  cpu_self = _Thread_Dispatch_disable();
   _SMP_Issue_action_jobs( targets, &jobs, cpu_max );
   _SMP_Wait_for_action_jobs( targets, &jobs, cpu_max, cpu_self );
-  _Thread_Dispatch_enable( cpu_self );
+
+  if ( isr_level == 0 ) {
+    _Thread_Dispatch_enable( cpu_self );
+  }
 }

testsuites/smptests/smpcache01/init.c

@@ -126,15 +126,12 @@ static void call_tests_isr_disabled( SMP_barrier_State *bs )
   broadcast_test_init();
 
   for (i = 0; i < RTEMS_ARRAY_SIZE( test_cases ); ++i) {
-    Per_CPU_Control *cpu_self;
-    ISR_Level        isr_level;
+    ISR_Level isr_level;
 
-    cpu_self = _Thread_Dispatch_disable();
     _ISR_Local_disable( isr_level );
     barrier( bs );
     ( *test_cases[ i ] )();
     _ISR_Local_enable( isr_level );
-    _Thread_Dispatch_enable( cpu_self );
     barrier( bs );
   }
 

testsuites/smptests/smpmulticast01/init.c

@@ -59,14 +59,11 @@ static void multicast_action_irq_disabled(
   void *arg
 )
 {
-  Per_CPU_Control *cpu_self;
   rtems_interrupt_level level;
 
-  cpu_self = _Thread_Dispatch_disable();
   rtems_interrupt_local_disable(level);
   _SMP_Multicast_action(targets, handler, arg);
   rtems_interrupt_local_enable(level);
-  _Thread_Dispatch_enable(cpu_self);
 }
 
 static void multicast_action_dispatch_disabled(