score: Work area initialization API change

The work areas (RTEMS work space and C program heap) will be initialized
now in a separate step and are no longer part of
rtems_initialize_data_structures().  Initialization is performed with
tables of Heap_Area entries.  This allows usage of scattered memory
areas present on various small scale micro-controllers.

The sbrk() support API changes also.  The bsp_sbrk_init() must now deal
with a minimum size for the first memory chunk to take the configured
work space size into account.

5 files changed, 95 insertions, 33 deletions

diff --git a/cpukit/score/include/rtems/score/heap.h b/cpukit/score/include/rtems/score/heap.h
index 964386a36f..36ef48f3b6 100644
--- a/cpukit/score/include/rtems/score/heap.h
+++ b/cpukit/score/include/rtems/score/heap.h
@@ -675,6 +675,36 @@ Heap_Resize_status _Heap_Resize_block(
   uintptr_t *new_size
 );
 
+RTEMS_INLINE_ROUTINE uintptr_t _Heap_Align_up(
+  uintptr_t value,
+  uintptr_t alignment
+)
+{
+  uintptr_t remainder = value % alignment;
+
+  if ( remainder != 0 ) {
+    return value - remainder + alignment;
+  } else {
+    return value;
+  }
+}
+
+/**
+ * @brief Returns the worst case overhead to manage a memory area.
+ */
+RTEMS_INLINE_ROUTINE uintptr_t _Heap_Area_overhead(
+  uintptr_t page_size
+)
+{
+  if ( page_size != 0 ) {
+    page_size = _Heap_Align_up( page_size, CPU_ALIGNMENT );
+  } else {
+    page_size = CPU_ALIGNMENT;
+  }
+
+  return 2 * (page_size - 1) + HEAP_BLOCK_HEADER_SIZE;
+}
+
 #if !defined(__RTEMS_APPLICATION__)
 
 #include <rtems/score/heap.inl>
diff --git a/cpukit/score/include/rtems/score/interr.h b/cpukit/score/include/rtems/score/interr.h
index 19342a3db8..2a21fe01eb 100644
--- a/cpukit/score/include/rtems/score/interr.h
+++ b/cpukit/score/include/rtems/score/interr.h
@@ -72,7 +72,8 @@ typedef enum {
   INTERNAL_ERROR_UNLIMITED_AND_MAXIMUM_IS_0,
   INTERNAL_ERROR_SHUTDOWN_WHEN_NOT_UP,
   INTERNAL_ERROR_GXX_KEY_ADD_FAILED,
-  INTERNAL_ERROR_GXX_MUTEX_INIT_FAILED
+  INTERNAL_ERROR_GXX_MUTEX_INIT_FAILED,
+  INTERNAL_ERROR_NO_MEMORY_FOR_HEAP
 } Internal_errors_Core_list;
 
 typedef uint32_t Internal_errors_t;
diff --git a/cpukit/score/include/rtems/score/wkspace.h b/cpukit/score/include/rtems/score/wkspace.h
index 10b80ccaab..db6eb38f96 100644
--- a/cpukit/score/include/rtems/score/wkspace.h
+++ b/cpukit/score/include/rtems/score/wkspace.h
@@ -36,19 +36,23 @@ extern "C" {
 #include <rtems/score/interr.h>
 
 /**
- * @brief Executive Workspace Control
+ *  @brief Executive workspace control.
  *
- *  The is the heap control structure that used to manage the
- *  RTEMS Executive Workspace.
+ *  This is the heap control structure used to manage the RTEMS Executive
+ *  Workspace.
  */
-SCORE_EXTERN Heap_Control _Workspace_Area;  /* executive heap header */
+SCORE_EXTERN Heap_Control _Workspace_Area;
 
 /**
  * @brief Workspace Handler Initialization
  *
  *  This routine performs the initialization necessary for this handler.
  */
-void _Workspace_Handler_initialization(void);
+void _Workspace_Handler_initialization(
+  Heap_Area *areas,
+  size_t area_count,
+  Heap_Initialization_or_extend_handler extend
+);
 
 /**
  * @brief Allocate Memory from Workspace
diff --git a/cpukit/score/inline/rtems/score/heap.inl b/cpukit/score/inline/rtems/score/heap.inl
index b9553714c4..59bdd7b142 100644
--- a/cpukit/score/inline/rtems/score/heap.inl
+++ b/cpukit/score/inline/rtems/score/heap.inl
@@ -108,20 +108,6 @@ RTEMS_INLINE_ROUTINE bool _Heap_Is_aligned(
   return (value % alignment) == 0;
 }
 
-RTEMS_INLINE_ROUTINE uintptr_t _Heap_Align_up(
-  uintptr_t value,
-  uintptr_t alignment
-)
-{
-  uintptr_t remainder = value % alignment;
-
-  if ( remainder != 0 ) {
-    return value - remainder + alignment;
-  } else {
-    return value;
-  }
-}
-
 RTEMS_INLINE_ROUTINE uintptr_t _Heap_Align_down(
   uintptr_t value,
   uintptr_t alignment
diff --git a/cpukit/score/src/wkspace.c b/cpukit/score/src/wkspace.c
index 842cade81b..7e58585173 100644
--- a/cpukit/score/src/wkspace.c
+++ b/cpukit/score/src/wkspace.c
@@ -28,28 +28,69 @@
 /*
  *  _Workspace_Handler_initialization
  */
-void _Workspace_Handler_initialization(void)
+void _Workspace_Handler_initialization(
+  Heap_Area *areas,
+  size_t area_count,
+  Heap_Initialization_or_extend_handler extend
+)
 {
-  uintptr_t memory_available = 0;
-  void *starting_address = rtems_configuration_get_work_space_start();
-  uintptr_t size = rtems_configuration_get_work_space_size();
+  Heap_Initialization_or_extend_handler init_or_extend = _Heap_Initialize;
+  uintptr_t remaining = rtems_configuration_get_work_space_size();
+  bool do_zero = rtems_configuration_get_do_zero_of_workspace();
+  bool unified = rtems_configuration_get_unified_work_area();
+  uintptr_t page_size = CPU_HEAP_ALIGNMENT;
+  uintptr_t overhead = _Heap_Area_overhead( page_size );
+  size_t i;
+
+  for (i = 0; i < area_count; ++i) {
+    Heap_Area *area = &areas [i];
+
+    if ( do_zero ) {
+      memset( area->begin, 0, area->size );
+    }
+
+    if ( area->size > overhead ) {
+      uintptr_t space_available;
+      uintptr_t size;
+
+      if ( unified ) {
+        size = area->size;
+      } else {
+        if ( remaining > 0 ) {
+          size = remaining < area->size - overhead ?
+            remaining + overhead : area->size;
+        } else {
+          size = 0;
+        }
+      }
+
+      space_available = (*init_or_extend)(
+        &_Workspace_Area,
+        area->begin,
+        size,
+        page_size
+      );
+
+      area->begin = (char *) area->begin + size;
+      area->size -= size;
 
-  if ( rtems_configuration_get_do_zero_of_workspace() )
-    memset( starting_address, 0, size );
+      if ( space_available < remaining ) {
+        remaining -= space_available;
+      } else {
+        remaining = 0;
+      }
 
-  memory_available = _Heap_Initialize(
-    &_Workspace_Area,
-    starting_address,
-    size,
-    CPU_HEAP_ALIGNMENT
-  );
+      init_or_extend = extend;
+    }
+  }
 
-  if ( memory_available == 0 )
+  if ( remaining > 0 ) {
     _Internal_error_Occurred(
       INTERNAL_ERROR_CORE,
       true,
       INTERNAL_ERROR_TOO_LITTLE_WORKSPACE
     );
+  }
 }
 
 /*