score: Multiprocessor Resource Sharing Protocol

Add basic support for the Multiprocessor Resource Sharing Protocol
(MrsP).

The Multiprocessor Resource Sharing Protocol (MrsP) is defined in A.
Burns and A.J.  Wellings, A Schedulability Compatible Multiprocessor
Resource Sharing Protocol - MrsP, Proceedings of the 25th Euromicro
Conference on Real-Time Systems (ECRTS 2013), July 2013.  It is a
generalization of the Priority Ceiling Protocol to SMP systems.  Each
MrsP semaphore uses a ceiling priority per scheduler instance.  These
ceiling priorities can be specified with rtems_semaphore_set_priority().
A task obtaining or owning a MrsP semaphore will execute with the
ceiling priority for its scheduler instance as specified by the MrsP
semaphore object.  Tasks waiting to get ownership of a MrsP semaphore
will not relinquish the processor voluntarily.  In case the owner of a
MrsP semaphore gets preempted it can ask all tasks waiting for this
semaphore to help out and temporarily borrow the right to execute on one
of their assigned processors.

The help out feature is not implemented with this patch.

1 files changed, 10 insertions, 0 deletions

diff --git a/cpukit/score/include/rtems/score/schedulerimpl.h b/cpukit/score/include/rtems/score/schedulerimpl.h
index 15a4207cfd..be841642ca 100644
--- a/cpukit/score/include/rtems/score/schedulerimpl.h
+++ b/cpukit/score/include/rtems/score/schedulerimpl.h
@@ -617,6 +617,16 @@ RTEMS_INLINE_ROUTINE bool _Scheduler_Get_by_id(
     && _Scheduler_Get_processor_count( scheduler ) > 0;
 }
 
+RTEMS_INLINE_ROUTINE bool _Scheduler_Is_id_valid( Objects_Id id )
+{
+  const Scheduler_Control *scheduler;
+  bool ok = _Scheduler_Get_by_id( id, &scheduler );
+
+  (void) scheduler;
+
+  return ok;
+}
+
 RTEMS_INLINE_ROUTINE uint32_t _Scheduler_Get_index(
   const Scheduler_Control *scheduler
 )