config: Add _Watchdog_Ticks_per_timeslice

Move the ticks per timeslice configuration constant out of the
configuration table.

Add WATCHDOG_TICKS_PER_TIMESLICE_DEFAULT and use it to provide a default
definition of the watchdog ticks per timeslice constant.

Update #3875.

5 files changed, 58 insertions, 9 deletions

diff --git a/cpukit/Makefile.am b/cpukit/Makefile.am
index 1d3935776b..1adcbb3ae9 100644
--- a/cpukit/Makefile.am
+++ b/cpukit/Makefile.am
@@ -1002,6 +1002,7 @@ librtemscpu_a_SOURCES += score/src/coretodhookunregister.c
 librtemscpu_a_SOURCES += score/src/watchdogremove.c
 librtemscpu_a_SOURCES += score/src/watchdogtick.c
 librtemscpu_a_SOURCES += score/src/watchdogtickssinceboot.c
+librtemscpu_a_SOURCES += score/src/watchdogtimeslicedefault.c
 librtemscpu_a_SOURCES += score/src/userextaddset.c
 librtemscpu_a_SOURCES += score/src/userext.c
 librtemscpu_a_SOURCES += score/src/userextremoveset.c
diff --git a/cpukit/include/rtems/confdefs.h b/cpukit/include/rtems/confdefs.h
index 1254e3d209..b1c3a4a2d2 100644
--- a/cpukit/include/rtems/confdefs.h
+++ b/cpukit/include/rtems/confdefs.h
@@ -1967,10 +1967,16 @@ extern "C" {
 #endif
 
 /** The configures the number of clock ticks per timeslice. */
-#ifndef CONFIGURE_TICKS_PER_TIMESLICE
-  #define CONFIGURE_TICKS_PER_TIMESLICE        50
+#if defined(CONFIGURE_TICKS_PER_TIMESLICE) && \
+  CONFIGURE_TICKS_PER_TIMESLICE != WATCHDOG_TICKS_PER_TIMESLICE_DEFAULT
+
+#ifdef CONFIGURE_INIT
+  const uint32_t _Watchdog_Ticks_per_timeslice =
+    CONFIGURE_TICKS_PER_TIMESLICE;
 #endif
 
+#endif /* CONFIGURE_TICKS_PER_TIMESLICE */
+
 /**@}*/ /* end of General Configuration */
 
 /*
@@ -2626,7 +2632,6 @@ struct _reent *__getreent(void)
    */
   const rtems_configuration_table Configuration = {
     CONFIGURE_EXECUTIVE_RAM_SIZE,             /* required RTEMS workspace */
-    CONFIGURE_TICKS_PER_TIMESLICE,            /* ticks per timeslice quantum */
     CONFIGURE_IDLE_TASK_BODY,                 /* user's IDLE task */
     CONFIGURE_IDLE_TASK_STACK_SIZE,           /* IDLE task stack size */
     #ifdef CONFIGURE_UNIFIED_WORK_AREAS       /* true for unified work areas */
diff --git a/cpukit/include/rtems/config.h b/cpukit/include/rtems/config.h
index 84917366f3..31a667a1d6 100644
--- a/cpukit/include/rtems/config.h
+++ b/cpukit/include/rtems/config.h
@@ -87,11 +87,6 @@ typedef struct {
   uintptr_t                      work_space_size;
 
   /** 
-   * This field specifies the number of ticks in each task's timeslice.
-   */
-  uint32_t                       ticks_per_timeslice;
-
-  /** 
    * This element points to the BSP's optional idle task which may override
    * the default one provided with RTEMS.
    */
@@ -163,7 +158,7 @@ uint32_t rtems_configuration_get_maximum_extensions( void );
         (_Watchdog_Nanoseconds_per_tick)
 
 #define rtems_configuration_get_ticks_per_timeslice() \
-        (Configuration.ticks_per_timeslice)
+        (_Watchdog_Ticks_per_timeslice)
 
 #define rtems_configuration_get_idle_task() \
         (Configuration.idle_task)
diff --git a/cpukit/include/rtems/score/watchdogticks.h b/cpukit/include/rtems/score/watchdogticks.h
index 226de39c24..ea2651954c 100644
--- a/cpukit/include/rtems/score/watchdogticks.h
+++ b/cpukit/include/rtems/score/watchdogticks.h
@@ -43,6 +43,11 @@ typedef uint32_t   Watchdog_Interval;
 #define WATCHDOG_NO_TIMEOUT 0
 
 /**
+ * @brief Default value for the watchdog ticks per timeslice.
+ */
+#define WATCHDOG_TICKS_PER_TIMESLICE_DEFAULT 50
+
+/**
  * @brief The watchdog ticks counter.
  *
  * With a 1ms watchdog tick, this counter overflows after 50 days since boot.
@@ -73,6 +78,14 @@ extern const uint32_t _Watchdog_Nanoseconds_per_tick;
  */
 extern const uint32_t _Watchdog_Ticks_per_second;
 
+/**
+ * @brief The watchdog ticks per timeslice.
+ *
+ * This constant is defined by the application configuration via
+ * <rtems/confdefs.h>.
+ */
+extern const uint32_t _Watchdog_Ticks_per_timeslice;
+
 /** @} */
 
 #ifdef __cplusplus
diff --git a/cpukit/score/src/watchdogtimeslicedefault.c b/cpukit/score/src/watchdogtimeslicedefault.c
new file mode 100644
index 0000000000..91be2b51e6
--- /dev/null
+++ b/cpukit/score/src/watchdogtimeslicedefault.c
@@ -0,0 +1,35 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
+ *
+ * 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/score/watchdogticks.h>
+
+const uint32_t _Watchdog_Ticks_per_timeslice =
+  WATCHDOG_TICKS_PER_TIMESLICE_DEFAULT;