rtems: Simplify semaphore configuration

The MrsP semaphore implementation predates the addition of
self-contained synchronization objects.  At this time, the potential
memory reduction was justified considering the more complex
configuration and additional use of the workspace.  With the
availability of self-contained synchronization options, e.g. POSIX
mutexes, this is no longer justified.  Memory constrained applications
should use the self-contained synchronization objects.   Remove the
CONFIGURE_MAXIMUM_MRSP_SEMAPHORES configuration option. This has only an
impact on applications which use SMP and a large number of scheduler
instances.

Update #3833.

cpukit/include/rtems/confdefs.h

@@ -2000,22 +2000,6 @@ extern rtems_initialization_tasks_table Initialization_tasks[];
   #define CONFIGURE_MAXIMUM_SEMAPHORES                 0
 #endif
 
-/*
- * This macro is calculated to specify the memory required for
- * Classic API Semaphores using MRSP. This is only available in
- * SMP configurations.
- */
-#if !defined(RTEMS_SMP) || \
-  !defined(CONFIGURE_MAXIMUM_MRSP_SEMAPHORES)
-  #define _CONFIGURE_MEMORY_FOR_MRSP_SEMAPHORES 0
-#else
-  #define _CONFIGURE_MEMORY_FOR_MRSP_SEMAPHORES \
-    CONFIGURE_MAXIMUM_MRSP_SEMAPHORES * \
-      _Configure_From_workspace( \
-        RTEMS_ARRAY_SIZE(_Scheduler_Table) * sizeof(Priority_Control) \
-      )
-#endif
-
 #ifndef CONFIGURE_MAXIMUM_MESSAGE_QUEUES
   /**
    * This configuration parameter specifies the maximum number of
@@ -2502,7 +2486,6 @@ struct _reent *__getreent(void)
      _CONFIGURE_TASKS, _CONFIGURE_TASKS) + \
    _CONFIGURE_MEMORY_FOR_TASKS( \
      _CONFIGURE_POSIX_THREADS, _CONFIGURE_POSIX_THREADS) + \
-   _CONFIGURE_MEMORY_FOR_MRSP_SEMAPHORES + \
    _CONFIGURE_MEMORY_FOR_POSIX_MESSAGE_QUEUES( \
      CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUES) + \
    _CONFIGURE_MEMORY_FOR_POSIX_SEMAPHORES( \
@@ -2786,7 +2769,10 @@ struct _reent *__getreent(void)
   #endif
 
   #if CONFIGURE_MAXIMUM_SEMAPHORES > 0
-    SEMAPHORE_INFORMATION_DEFINE( CONFIGURE_MAXIMUM_SEMAPHORES );
+    SEMAPHORE_INFORMATION_DEFINE(
+      CONFIGURE_MAXIMUM_SEMAPHORES,
+      _CONFIGURE_SCHEDULER_COUNT
+    );
   #endif
 
   #if _CONFIGURE_TIMERS > 0
@@ -3171,6 +3157,10 @@ struct _reent *__getreent(void)
   #warning "The CONFIGURE_NUMBER_OF_TERMIOS_PORTS configuration option is obsolete since RTEMS 5.1"
 #endif
 
+#ifdef CONFIGURE_MAXIMUM_MRSP_SEMAPHORES
+  #warning "The CONFIGURE_MAXIMUM_MRSP_SEMAPHORES configuration option is obsolete since RTEMS 5.1"
+#endif
+
 #ifdef CONFIGURE_MAXIMUM_POSIX_BARRIERS
   #warning "The CONFIGURE_MAXIMUM_POSIX_BARRIERS configuration option is obsolete since RTEMS 5.1"
 #endif

cpukit/include/rtems/rtems/semdata.h

@@ -108,9 +108,32 @@ void _Semaphore_MP_Send_extract_proxy (
  * This macro should only be used by <rtems/confdefs.h>.
  *
  * @param max The configured object maximum (the OBJECTS_UNLIMITED_OBJECTS flag
- * may be set).
+ *   may be set).
+ * @param scheduler_count The configured scheduler count (only used in SMP
+ *   configurations).
  */
-#define SEMAPHORE_INFORMATION_DEFINE( max ) \
+#if defined(RTEMS_SMP)
+#define SEMAPHORE_INFORMATION_DEFINE( max, scheduler_count ) \
+  typedef union { \
+    Objects_Control Object; \
+    Semaphore_Control Semaphore; \
+    struct { \
+      Objects_Control Object; \
+      MRSP_Control Control; \
+      Priority_Control ceiling_priorities[ scheduler_count ]; \
+    } MRSP; \
+  } Semaphore_Configured_control; \
+  OBJECTS_INFORMATION_DEFINE( \
+    _Semaphore, \
+    OBJECTS_CLASSIC_API, \
+    OBJECTS_RTEMS_SEMAPHORES, \
+    Semaphore_Configured_control, \
+    max, \
+    OBJECTS_NO_STRING_NAME, \
+    _Semaphore_MP_Send_extract_proxy \
+  )
+#else
+#define SEMAPHORE_INFORMATION_DEFINE( max, scheduler_count ) \
   OBJECTS_INFORMATION_DEFINE( \
     _Semaphore, \
     OBJECTS_CLASSIC_API, \
@@ -120,6 +143,7 @@ void _Semaphore_MP_Send_extract_proxy (
     OBJECTS_NO_STRING_NAME, \
     _Semaphore_MP_Send_extract_proxy \
   )
+#endif
 
 /** @} */
 

cpukit/include/rtems/score/mrsp.h

@@ -73,7 +73,7 @@ typedef struct {
   /**
    * @brief One ceiling priority per scheduler instance.
    */
-  Priority_Control *ceiling_priorities;
+  Priority_Control ceiling_priorities[ RTEMS_ZERO_LENGTH_ARRAY ];
 } MRSP_Control;
 
 /** @} */

cpukit/include/rtems/score/mrspimpl.h

@@ -7,7 +7,7 @@
  */
 
 /*
- * Copyright (c) 2014, 2016 embedded brains GmbH.  All rights reserved.
+ * Copyright (c) 2014, 2019 embedded brains GmbH.  All rights reserved.
  *
  *  embedded brains GmbH
  *  Dornierstr. 4
@@ -31,7 +31,6 @@
 #include <rtems/score/status.h>
 #include <rtems/score/threadqimpl.h>
 #include <rtems/score/watchdogimpl.h>
-#include <rtems/score/wkspace.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -302,13 +301,6 @@ RTEMS_INLINE_ROUTINE Status_Control _MRSP_Initialize(
     return STATUS_INVALID_NUMBER;
   }
 
-  mrsp->ceiling_priorities = _Workspace_Allocate(
-    sizeof( *mrsp->ceiling_priorities ) * scheduler_count
-  );
-  if ( mrsp->ceiling_priorities == NULL ) {
-    return STATUS_NO_MEMORY;
-  }
-
   for ( i = 0 ; i < scheduler_count ; ++i ) {
     const Scheduler_Control *scheduler_of_index;
 
@@ -524,7 +516,6 @@ RTEMS_INLINE_ROUTINE void _MRSP_Destroy(
 {
   _MRSP_Release( mrsp, queue_context );
   _Thread_queue_Destroy( &mrsp->Wait_queue );
-  _Workspace_Free( mrsp->ceiling_priorities );
 }
 
 /** @} */

testsuites/smptests/smpfatal03/init.c

@@ -89,7 +89,6 @@ static void fatal_extension(
 #define CONFIGURE_MAXIMUM_TASKS 1
 #define CONFIGURE_MAXIMUM_TIMERS 1
 #define CONFIGURE_MAXIMUM_SEMAPHORES 1
-#define CONFIGURE_MAXIMUM_MRSP_SEMAPHORES 1
 
 #define CONFIGURE_RTEMS_INIT_TASKS_TABLE
 

testsuites/smptests/smpmrsp01/init.c

@@ -1777,7 +1777,6 @@ static void Init(rtems_task_argument arg)
 
 #define CONFIGURE_MAXIMUM_TASKS (2 * CPU_COUNT + 2)
 #define CONFIGURE_MAXIMUM_SEMAPHORES (MRSP_COUNT + 1)
-#define CONFIGURE_MAXIMUM_MRSP_SEMAPHORES MRSP_COUNT
 #define CONFIGURE_MAXIMUM_TIMERS 1
 
 #define CONFIGURE_MAXIMUM_PROCESSORS CPU_COUNT

testsuites/smptests/smpscheduler02/init.c

@@ -427,7 +427,6 @@ static void Init(rtems_task_argument arg)
 
 #define CONFIGURE_MAXIMUM_TASKS 2
 #define CONFIGURE_MAXIMUM_SEMAPHORES 2
-#define CONFIGURE_MAXIMUM_MRSP_SEMAPHORES 1
 
 /* Lets see when the first RTEMS system hits this limit */
 #define CONFIGURE_MAXIMUM_PROCESSORS 64

testsuites/sptests/spmrsp01/init.c

@@ -327,7 +327,6 @@ static void Init(rtems_task_argument arg)
 
 #define CONFIGURE_MAXIMUM_TASKS 2
 #define CONFIGURE_MAXIMUM_SEMAPHORES 1
-#define CONFIGURE_MAXIMUM_MRSP_SEMAPHORES 1
 
 #define CONFIGURE_INIT_TASK_PRIORITY 2
 

testsuites/tmtests/tmfine01/init.c

@@ -816,8 +816,6 @@ static void Init(rtems_task_argument arg)
 
 #define CONFIGURE_MAXIMUM_SEMAPHORES (1 + CPU_COUNT)
 
-#define CONFIGURE_MAXIMUM_MRSP_SEMAPHORES CPU_COUNT
-
 #define CONFIGURE_MAXIMUM_MESSAGE_QUEUES CPU_COUNT
 
 #define CONFIGURE_MESSAGE_BUFFER_MEMORY \