score: Add per scheduler instance maximum priority

The priority values are only valid within a scheduler instance.  Thus,
the maximum priority value must be defined per scheduler instance.  The
first scheduler instance defines PRIORITY_MAXIMUM.  This implies that
RTEMS_MAXIMUM_PRIORITY and POSIX_SCHEDULER_MAXIMUM_PRIORITY are only
valid for threads of the first scheduler instance.  Further
API/implementation changes are necessary to fix this.

Update #2556.

1 files changed, 14 insertions, 0 deletions

diff --git a/cpukit/score/include/rtems/score/scheduler.h b/cpukit/score/include/rtems/score/scheduler.h
index 5296644aeb..1e6236fa4d 100644
--- a/cpukit/score/include/rtems/score/scheduler.h
+++ b/cpukit/score/include/rtems/score/scheduler.h
@@ -201,6 +201,14 @@ struct Scheduler_Control {
   Scheduler_Operations Operations;
 
   /**
+   * @brief The maximum priority value of this scheduler.
+   *
+   * It defines the lowest (least important) thread priority for this
+   * scheduler.  For example the idle threads have this priority.
+   */
+  Priority_Control maximum_priority;
+
+  /**
    * @brief The scheduler name.
    */
   uint32_t name;
@@ -555,6 +563,12 @@ void _Scheduler_default_Start_idle(
   #define SCHEDULER_OPERATION_DEFAULT_GET_SET_AFFINITY
 #endif
 
+/**
+ * @brief This defines the lowest (least important) thread priority of the
+ * first scheduler instance.
+ */
+#define PRIORITY_MAXIMUM ( _Scheduler_Table[ 0 ].maximum_priority )
+
 /**@}*/
 
 #ifdef __cplusplus