score: Simplify FP context allocation

Use the stack area to allocate the FP context.  This considerably
simplifies the application configuration since the task count no longer
influences the configured work space size.  With this change the stack
space size is overestimated since an FP context for each thread is
accounted.  Memory constraint applications can use the stack size for
fine tuning.

Update #3835.

3 files changed, 22 insertions, 45 deletions

diff --git a/cpukit/include/rtems/confdefs.h b/cpukit/include/rtems/confdefs.h
index 659fee936f..a356a94118 100644
--- a/cpukit/include/rtems/confdefs.h
+++ b/cpukit/include/rtems/confdefs.h
@@ -30,6 +30,7 @@
 #include <rtems/ioimpl.h>
 #include <rtems/sysinit.h>
 #include <rtems/score/apimutex.h>
+#include <rtems/score/context.h>
 #include <rtems/score/percpu.h>
 #include <rtems/score/userextimpl.h>
 #include <rtems/score/wkspace.h>
@@ -1315,10 +1316,10 @@ extern rtems_initialization_tasks_table Initialization_tasks[];
  */
 #ifdef CONFIGURE_TASK_STACK_FROM_ALLOCATOR
   #define _Configure_From_stackspace(_stack_size) \
-    CONFIGURE_TASK_STACK_FROM_ALLOCATOR(_stack_size)
+    CONFIGURE_TASK_STACK_FROM_ALLOCATOR(_stack_size + CONTEXT_FP_SIZE)
 #else
   #define _Configure_From_stackspace(_stack_size) \
-    _Configure_From_workspace(_stack_size)
+    _Configure_From_workspace(_stack_size + CONTEXT_FP_SIZE)
 #endif
 
 /**
@@ -2313,16 +2314,6 @@ struct _reent *__getreent(void)
  */
 #ifndef CONFIGURE_EXECUTIVE_RAM_SIZE
 
-/*
- * Account for allocating the following per object
- *   + array of object control structures
- *   + local pointer table -- pointer per object plus a zero'th
- *     entry in the local pointer table.
- */
-#define _CONFIGURE_MEMORY_FOR_TASKS(_tasks, _number_FP_tasks) \
-  (_Configure_Max_Objects(_number_FP_tasks) \
-    * _Configure_From_workspace(CONTEXT_FP_SIZE))
-
 /**
  * The following macro is used to calculate the memory allocated by RTEMS
  * for the message buffers associated with a particular message queue.
@@ -2359,41 +2350,12 @@ struct _reent *__getreent(void)
 #endif
 
 /**
- * This defines the formula used to compute the amount of memory
- * reserved for internal task control structures.
- */
-#if CPU_IDLE_TASK_IS_FP == TRUE
-  #define _CONFIGURE_MEMORY_FOR_INTERNAL_TASKS \
-    _CONFIGURE_MEMORY_FOR_TASKS( \
-      _CONFIGURE_IDLE_TASKS_COUNT + _CONFIGURE_MPCI_RECEIVE_SERVER_COUNT, \
-      _CONFIGURE_IDLE_TASKS_COUNT + _CONFIGURE_MPCI_RECEIVE_SERVER_COUNT \
-    )
-#else
-  #define _CONFIGURE_MEMORY_FOR_INTERNAL_TASKS \
-    _CONFIGURE_MEMORY_FOR_TASKS( \
-      _CONFIGURE_IDLE_TASKS_COUNT + _CONFIGURE_MPCI_RECEIVE_SERVER_COUNT, \
-      _CONFIGURE_MPCI_RECEIVE_SERVER_COUNT \
-    )
-#endif
-
-/**
- * This macro accounts for general RTEMS system overhead.
- */
-#define _CONFIGURE_MEMORY_FOR_SYSTEM_OVERHEAD \
-  _CONFIGURE_MEMORY_FOR_INTERNAL_TASKS
-
-/**
  * This calculates the memory required for the executive workspace.
  *
  * This is an internal parameter.
  */
 #define CONFIGURE_EXECUTIVE_RAM_SIZE \
 ( \
-   _CONFIGURE_MEMORY_FOR_SYSTEM_OVERHEAD + \
-   _CONFIGURE_MEMORY_FOR_TASKS( \
-     _CONFIGURE_TASKS, _CONFIGURE_TASKS) + \
-   _CONFIGURE_MEMORY_FOR_TASKS( \
-     CONFIGURE_MAXIMUM_POSIX_THREADS, CONFIGURE_MAXIMUM_POSIX_THREADS) + \
    _CONFIGURE_MEMORY_FOR_POSIX_MESSAGE_QUEUES( \
      CONFIGURE_MAXIMUM_POSIX_MESSAGE_QUEUES) + \
    _CONFIGURE_MEMORY_FOR_POSIX_SEMAPHORES( \
diff --git a/cpukit/include/rtems/score/context.h b/cpukit/include/rtems/score/context.h
index a01e29683c..364f8c1182 100644
--- a/cpukit/include/rtems/score/context.h
+++ b/cpukit/include/rtems/score/context.h
@@ -49,7 +49,9 @@ extern "C" {
  *  to store a full floating point context.
  */
 #if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
-  #define CONTEXT_FP_SIZE CPU_CONTEXT_FP_SIZE
+  #define CONTEXT_FP_SIZE \
+    ( ( CPU_CONTEXT_FP_SIZE + CPU_HEAP_ALIGNMENT - 1 ) \
+      & ~( CPU_HEAP_ALIGNMENT - 1 ) )
 #else
   #define CONTEXT_FP_SIZE 0
 #endif
diff --git a/cpukit/include/rtems/score/stackimpl.h b/cpukit/include/rtems/score/stackimpl.h
index f4671dea60..60704534c7 100644
--- a/cpukit/include/rtems/score/stackimpl.h
+++ b/cpukit/include/rtems/score/stackimpl.h
@@ -22,6 +22,7 @@
 #define _RTEMS_SCORE_STACKIMPL_H
 
 #include <rtems/score/stack.h>
+#include <rtems/score/context.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -74,15 +75,27 @@ RTEMS_INLINE_ROUTINE uint32_t _Stack_Minimum (void)
  * a valid stack area on this processor, and false otherwise.
  *
  * @param size The stack size to check.
+ * @param is_fp Indicates if the stack is for a floating-point thread.
  *
  * @retval true @a size is large enough.
  * @retval false @a size is not large enough.
  */
-RTEMS_INLINE_ROUTINE bool _Stack_Is_enough (
-  size_t size
+RTEMS_INLINE_ROUTINE bool _Stack_Is_enough(
+  size_t size,
+  bool   is_fp
 )
 {
-  return ( size >= _Stack_Minimum() );
+  size_t minimum;
+
+  minimum = _Stack_Minimum();
+
+#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
+  if ( is_fp ) {
+    minimum += CONTEXT_FP_SIZE;
+  }
+#endif
+
+  return ( size >= minimum );
 }
 
 /**