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.

1 files changed, 17 insertions, 22 deletions

diff --git a/cpukit/score/src/threadinitialize.c b/cpukit/score/src/threadinitialize.c
index c6e8abf979..48444824b2 100644
--- a/cpukit/score/src/threadinitialize.c
+++ b/cpukit/score/src/threadinitialize.c
@@ -43,9 +43,6 @@ bool _Thread_Initialize(
 )
 {
   uintptr_t                tls_size = _TLS_Get_size();
-  #if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
-    void                  *fp_area = NULL;
-  #endif
   bool                     extension_status;
   size_t                   i;
   Scheduler_Node          *scheduler_node;
@@ -91,6 +88,13 @@ bool _Thread_Initialize(
   if ( stack_area == NULL ) {
 #endif
     stack_size = _Stack_Ensure_minimum( stack_size );
+
+#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
+    if ( is_fp ) {
+      stack_size += CONTEXT_FP_SIZE;
+    }
+#endif
+
     stack_area = _Stack_Allocate( stack_size );
 
     if ( stack_area == NULL ) {
@@ -102,6 +106,16 @@ bool _Thread_Initialize(
   }
 #endif
 
+  /* Allocate floating-point context in stack area */
+#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
+  if ( is_fp ) {
+    the_thread->fp_context = stack_area;
+    the_thread->Start.fp_context = stack_area;
+    stack_size -= CONTEXT_FP_SIZE;
+    stack_area = (char *) stack_area + CONTEXT_FP_SIZE;
+  }
+#endif
+
   _Stack_Initialize(
      &the_thread->Start.Initial_stack,
      stack_area,
@@ -124,19 +138,6 @@ bool _Thread_Initialize(
   }
 
   /*
-   *  Allocate the floating point area for this thread
-   */
-  #if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
-    if ( is_fp ) {
-      fp_area = _Workspace_Allocate( CONTEXT_FP_SIZE );
-      if ( !fp_area )
-        goto failed;
-    }
-    the_thread->fp_context       = fp_area;
-    the_thread->Start.fp_context = fp_area;
-  #endif
-
-  /*
    *  Get thread queue heads
    */
   the_thread->Wait.spare_heads = _Freechain_Get(
@@ -301,16 +302,10 @@ failed:
 #endif
 
   _Workspace_Free( the_thread->Start.tls_area );
-
   _Freechain_Put(
     &information->Thread_queue_heads.Free,
     the_thread->Wait.spare_heads
   );
-
-  #if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
-    _Workspace_Free( fp_area );
-  #endif
-
   _Stack_Free( the_thread->Start.allocated_stack );
   return false;
 }