score: Optimize Workspace Handler initialization

The BSPs provide memory for the workspace initialization via
_Memory_Get().  Most BSPs provide exactly one memory area.  Only two
BSPs provide more than one memory area (arm/altera-cyclone-v and
bsps/powerpc/mpc55xxevb).  Only if more than one memory area is
provided, there is a need to use _Heap_Extend().  Provide two
implementations to initialize the workspace handler and let the BSP
select one of the implementations based on the number of provided memory
areas.  This gets rid of a dependency on _Heap_Extend().  It also avoids
dead code sections for most BSPs.

1 files changed, 113 insertions, 0 deletions

diff --git a/cpukit/include/rtems/score/wkspaceinitone.h b/cpukit/include/rtems/score/wkspaceinitone.h
new file mode 100644
index 0000000000..c68e1b5db1
--- /dev/null
+++ b/cpukit/include/rtems/score/wkspaceinitone.h
@@ -0,0 +1,113 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup RTEMSScoreWorkspace
+ *
+ * @brief This header file provides the implementation of
+ *   _Workspace_Initialize_for_one_area().
+ */
+
+/*
+ * Copyright (C) 2012, 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.
+ */
+
+#ifndef _RTEMS_SCORE_WKSPACEINITONE_H
+#define _RTEMS_SCORE_WKSPACEINITONE_H
+
+#include <rtems/score/wkspace.h>
+#include <rtems/score/assert.h>
+#include <rtems/score/heapimpl.h>
+#include <rtems/score/interr.h>
+#include <rtems/score/memory.h>
+#include <rtems/config.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @ingroup RTEMSScoreWorkspace
+ *
+ * @brief Initializes the RTEMS Workspace with support for exactly one memory
+ *   area.
+ *
+ * This implementation should be used by BSPs which provide exactly one memory
+ * area via _Memory_Get() to implement _Workspace_Handler_initialization().
+ */
+RTEMS_INLINE_ROUTINE void _Workspace_Initialize_for_one_area( void )
+{
+  uintptr_t page_size;
+  uintptr_t wkspace_size;
+  uintptr_t wkspace_size_with_overhead;
+  uintptr_t available_size;
+
+  page_size = CPU_HEAP_ALIGNMENT;
+  wkspace_size = rtems_configuration_get_work_space_size();
+  wkspace_size_with_overhead = wkspace_size + _Heap_Area_overhead( page_size );
+
+  if ( wkspace_size < wkspace_size_with_overhead ) {
+    const Memory_Information *mem;
+    Memory_Area              *area;
+    uintptr_t                 free_size;
+    uintptr_t                 size;
+
+    mem = _Memory_Get();
+    _Assert( _Memory_Get_count( mem ) == 1 );
+
+    area = _Memory_Get_area( mem, 0 );
+    free_size = _Memory_Get_free_size( area );
+
+    if ( rtems_configuration_get_unified_work_area() ) {
+      size = free_size;
+    } else {
+      size = wkspace_size_with_overhead;
+    }
+
+    available_size = _Heap_Initialize(
+      &_Workspace_Area,
+      _Memory_Get_free_begin( area ),
+      size,
+      page_size
+    );
+
+    _Memory_Consume( area, size );
+  } else {
+    /* An unsigned integer overflow happened */
+    available_size = 0;
+  }
+
+  if ( wkspace_size > available_size ) {
+    _Internal_error( INTERNAL_ERROR_TOO_LITTLE_WORKSPACE );
+  }
+
+  _Heap_Protection_set_delayed_free_fraction( &_Workspace_Area, 1 );
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTEMS_SCORE_WKSPACEINITONE_H */