rtems: Avoid Giant lock for some task operations

Avoid Giant lock for rtems_task_set_priority(), rtems_task_suspend() and
rtems_task_resume().

Update #2555.

1 files changed, 83 insertions, 37 deletions

diff --git a/cpukit/rtems/src/taskmp.c b/cpukit/rtems/src/taskmp.c
index bca241fc5d..d59db2e313 100644
--- a/cpukit/rtems/src/taskmp.c
+++ b/cpukit/rtems/src/taskmp.c
@@ -24,6 +24,17 @@
 #include <rtems/score/threadimpl.h>
 #include <rtems/score/threadqimpl.h>
 
+/**
+ *  The following data structure defines the packet used to perform
+ *  remote task operations.
+ */
+typedef struct {
+  rtems_packet_prefix               Prefix;
+  RTEMS_tasks_MP_Remote_operations  operation;
+  rtems_name                        name;
+  rtems_task_priority               the_priority;
+}   RTEMS_tasks_MP_Packet;
+
 RTEMS_STATIC_ASSERT(
   sizeof(RTEMS_tasks_MP_Packet) <= MP_PACKET_MINIMUM_PACKET_SIZE,
   RTEMS_tasks_MP_Packet
@@ -34,6 +45,17 @@ static RTEMS_tasks_MP_Packet *_RTEMS_tasks_MP_Get_packet( void )
   return (RTEMS_tasks_MP_Packet *) _MPCI_Get_packet();
 }
 
+static RTEMS_tasks_MP_Packet *_RTEMS_tasks_MP_Get_request_packet(
+  Objects_Id id
+)
+{
+  if ( !_Thread_MP_Is_remote( id ) ) {
+    return NULL;
+  }
+
+  return _RTEMS_tasks_MP_Get_packet();
+}
+
 /*
  *  _RTEMS_tasks_MP_Send_process_packet
  *
@@ -73,54 +95,78 @@ void _RTEMS_tasks_MP_Send_process_packet (
   }
 }
 
-/*
- *  _RTEMS_tasks_MP_Send_request_packet
- *
- */
+static rtems_status_code _RTEMS_tasks_MP_Send_request_packet(
+  RTEMS_tasks_MP_Packet            *the_packet,
+  Objects_Id                        id,
+  RTEMS_tasks_MP_Remote_operations  operation
+)
+{
+  the_packet->Prefix.the_class  = MP_PACKET_TASKS;
+  the_packet->Prefix.length     = sizeof( *the_packet );
+  the_packet->Prefix.to_convert = sizeof( *the_packet );
+  the_packet->Prefix.id         = id;
+  the_packet->operation         = operation;
+
+  return _MPCI_Send_request_packet(
+    _Objects_Get_node( id ),
+    &the_packet->Prefix,
+    STATES_READY,    /* Not used */
+    RTEMS_TIMEOUT
+  );
+}
 
-rtems_status_code _RTEMS_tasks_MP_Send_request_packet (
-  RTEMS_tasks_MP_Remote_operations operation,
-  Objects_Id                       task_id,
-  rtems_task_priority              new_priority
+rtems_status_code _RTEMS_tasks_MP_Set_priority(
+  rtems_id             id,
+  rtems_task_priority  new_priority,
+  rtems_task_priority *old_priority
 )
 {
   RTEMS_tasks_MP_Packet *the_packet;
 
-  switch ( operation ) {
+  the_packet = _RTEMS_tasks_MP_Get_request_packet( id );
+  if ( the_packet == NULL ) {
+    return RTEMS_INVALID_ID;
+  }
 
-    case RTEMS_TASKS_MP_SUSPEND_REQUEST:
-    case RTEMS_TASKS_MP_RESUME_REQUEST:
-    case RTEMS_TASKS_MP_SET_PRIORITY_REQUEST:
+  the_packet->the_priority = new_priority;
+  _Thread_Executing->Wait.return_argument = old_priority;
+  return _RTEMS_tasks_MP_Send_request_packet(
+    the_packet,
+    id,
+    RTEMS_TASKS_MP_SET_PRIORITY_REQUEST
+  );
+}
 
-      the_packet                    = _RTEMS_tasks_MP_Get_packet();
-      the_packet->Prefix.the_class  = MP_PACKET_TASKS;
-      the_packet->Prefix.length     = sizeof ( RTEMS_tasks_MP_Packet );
-      the_packet->Prefix.to_convert = sizeof ( RTEMS_tasks_MP_Packet );
-      the_packet->operation         = operation;
-      the_packet->Prefix.id         = task_id;
-      the_packet->the_priority      = new_priority;
+rtems_status_code _RTEMS_tasks_MP_Suspend( rtems_id id )
+{
+  RTEMS_tasks_MP_Packet *the_packet;
 
-      return _MPCI_Send_request_packet(
-        _Objects_Get_node( task_id ),
-        &the_packet->Prefix,
-        STATES_READY,    /* Not used */
-        RTEMS_TIMEOUT
-      );
-      break;
+  the_packet = _RTEMS_tasks_MP_Get_request_packet( id );
+  if ( the_packet == NULL ) {
+    return RTEMS_INVALID_ID;
+  }
 
-    case RTEMS_TASKS_MP_ANNOUNCE_CREATE:
-    case RTEMS_TASKS_MP_ANNOUNCE_DELETE:
-    case RTEMS_TASKS_MP_SUSPEND_RESPONSE:
-    case RTEMS_TASKS_MP_RESUME_RESPONSE:
-    case RTEMS_TASKS_MP_SET_PRIORITY_RESPONSE:
-      break;
+  return _RTEMS_tasks_MP_Send_request_packet(
+    the_packet,
+    id,
+    RTEMS_TASKS_MP_SUSPEND_REQUEST
+  );
+}
 
+rtems_status_code _RTEMS_tasks_MP_Resume( rtems_id id )
+{
+  RTEMS_tasks_MP_Packet *the_packet;
+
+  the_packet = _RTEMS_tasks_MP_Get_request_packet( id );
+  if ( the_packet == NULL ) {
+    return RTEMS_INVALID_ID;
   }
-  /*
-   *  The following line is included to satisfy compilers which
-   *  produce warnings when a function does not end with a return.
-   */
-  return RTEMS_SUCCESSFUL;
+
+  return _RTEMS_tasks_MP_Send_request_packet(
+    the_packet,
+    id,
+    RTEMS_TASKS_MP_RESUME_REQUEST
+  );
 }
 
 /*