rtems: Allow initially locked MrsP semaphores

Rejecting initially locked MrsP semaphores was due to a limitiation of
the early limitiation of the MrsP protocol.  This limitation no longer
exists.

2 files changed, 22 insertions, 9 deletions

diff --git a/cpukit/include/rtems/rtems/sem.h b/cpukit/include/rtems/rtems/sem.h
index 1f0c952294..e117f1c211 100644
--- a/cpukit/include/rtems/rtems/sem.h
+++ b/cpukit/include/rtems/rtems/sem.h
@@ -240,9 +240,6 @@ extern "C" {
  * * When the directive operates on a global object, the directive sends a
  *   message to remote nodes.  This may preempt the calling task.
  *
- * * When a semaphore using the MrsP locking protocol is created, the initial
- *   count shall be exactly one.
- *
  * * The number of semaphores available to the application is configured
  *   through the #CONFIGURE_MAXIMUM_SEMAPHORES application configuration
  *   option.
diff --git a/cpukit/include/rtems/score/mrspimpl.h b/cpukit/include/rtems/score/mrspimpl.h
index 3cd5bcf33c..89711d6b1b 100644
--- a/cpukit/include/rtems/score/mrspimpl.h
+++ b/cpukit/include/rtems/score/mrspimpl.h
@@ -295,12 +295,13 @@ RTEMS_INLINE_ROUTINE Status_Control _MRSP_Initialize(
   bool                     initially_locked
 )
 {
-  uint32_t scheduler_count = _Scheduler_Count;
-  uint32_t i;
+  Thread_queue_Context queue_context;
+  ISR_Level            level;
+  size_t               scheduler_count;
+  size_t               i;
+  Status_Control       status;
 
-  if ( initially_locked ) {
-    return STATUS_INVALID_NUMBER;
-  }
+  scheduler_count = _Scheduler_Count;
 
   for ( i = 0 ; i < scheduler_count ; ++i ) {
     const Scheduler_Control *scheduler_of_index;
@@ -316,7 +317,22 @@ RTEMS_INLINE_ROUTINE Status_Control _MRSP_Initialize(
   }
 
   _Thread_queue_Object_initialize( &mrsp->Wait_queue );
-  return STATUS_SUCCESSFUL;
+
+  if ( !initially_locked ) {
+    return STATUS_SUCCESSFUL;
+  }
+
+  _Thread_queue_Context_initialize( &queue_context );
+  _Thread_queue_Context_ISR_disable( &queue_context, level );
+  _Thread_queue_Context_set_ISR_level( &queue_context, level );
+  _MRSP_Acquire_critical( mrsp, &queue_context );
+  status = _MRSP_Claim_ownership( mrsp, executing, &queue_context );
+
+  if ( status != STATUS_SUCCESSFUL ) {
+    _Thread_queue_Destroy( &mrsp->Wait_queue );
+  }
+
+  return status;
 }
 
 /**