rtems: Add rtems_scheduler_get_maximum_priority()

Update #3636.

cpukit/Makefile.am

@@ -755,6 +755,7 @@ librtemscpu_a_SOURCES += rtems/src/rtemsobjectidgetnode.c
 librtemscpu_a_SOURCES += rtems/src/rtemsobjectsetname.c
 librtemscpu_a_SOURCES += rtems/src/rtemstimer.c
 librtemscpu_a_SOURCES += rtems/src/scheduleraddprocessor.c
+librtemscpu_a_SOURCES += rtems/src/schedulergetmaxprio.c
 librtemscpu_a_SOURCES += rtems/src/schedulergetprocessorset.c
 librtemscpu_a_SOURCES += rtems/src/scheduleridentbyprocessor.c
 librtemscpu_a_SOURCES += rtems/src/scheduleridentbyprocessorset.c

cpukit/include/rtems/rtems/tasks.h

@@ -654,6 +654,21 @@ rtems_status_code rtems_scheduler_remove_processor(
   uint32_t cpu_index
 );
 
+/**
+ * @brief Gets the maximum task priority of the specified scheduler instance.
+ *
+ * @param[in] scheduler_id Identifier of the scheduler instance.
+ * @param[out] priority Pointer to a task priority value.
+ *
+ * @retval RTEMS_SUCCESSFUL Successful operation.
+ * @retval RTEMS_INVALID_ADDRESS The @a priority parameter is @c NULL.
+ * @retval RTEMS_INVALID_ID Invalid scheduler instance identifier.
+ */
+rtems_status_code rtems_scheduler_get_maximum_priority(
+  rtems_id             scheduler_id,
+  rtems_task_priority *priority
+);
+
 /**@}*/
 
 #ifdef __cplusplus

cpukit/rtems/src/schedulergetmaxprio.c

@@ -0,0 +1,53 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (C) 2018 embedded brains GmbH
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/rtems/tasks.h>
+#include <rtems/score/schedulerimpl.h>
+
+rtems_status_code rtems_scheduler_get_maximum_priority(
+  rtems_id             scheduler_id,
+  rtems_task_priority *priority
+)
+{
+  uint32_t index;
+
+  if ( priority == NULL ) {
+    return RTEMS_INVALID_ADDRESS;
+  }
+
+  index = _Scheduler_Get_index_by_id( scheduler_id );
+  if ( index >= _Scheduler_Count ) {
+    return RTEMS_INVALID_ID;
+  }
+
+  *priority = _Scheduler_Table[ index ].maximum_priority;
+  return RTEMS_SUCCESSFUL;
+}

testsuites/sptests/spscheduler01/init.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2017 embedded brains GmbH.  All rights reserved.
+ * Copyright (c) 2014, 2018 embedded brains GmbH.  All rights reserved.
  *
  *  embedded brains GmbH
  *  Dornierstr. 4
@@ -474,6 +474,29 @@ static void test_scheduler_ident(void)
   rtems_test_assert(scheduler_id == expected_id);
 }
 
+static void test_scheduler_get_max_prio(void)
+{
+  rtems_status_code sc;
+  rtems_task_priority priority;
+  rtems_id scheduler_id;
+
+  priority = 0;
+  sc = rtems_scheduler_get_maximum_priority(invalid_id, &priority);
+  rtems_test_assert(sc == RTEMS_INVALID_ID);
+  rtems_test_assert(priority == 0);
+
+  sc = rtems_task_get_scheduler(RTEMS_SELF, &scheduler_id);
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+
+  sc = rtems_scheduler_get_maximum_priority(scheduler_id, NULL);
+  rtems_test_assert(sc == RTEMS_INVALID_ADDRESS);
+
+  priority = 0;
+  sc = rtems_scheduler_get_maximum_priority(scheduler_id, &priority);
+  rtems_test_assert(sc == RTEMS_SUCCESSFUL);
+  rtems_test_assert(priority == 255);
+}
+
 static void test_scheduler_get_processors(void)
 {
   rtems_status_code sc;
@@ -601,6 +624,7 @@ static void Init(rtems_task_argument arg)
   test_task_get_set_affinity();
   test_task_get_set_scheduler();
   test_scheduler_ident();
+  test_scheduler_get_max_prio();
   test_scheduler_get_processors();
   test_scheduler_add_remove_processors();
   test_task_get_priority();