score: Add PER_CPU_DATA_NEED_INITIALIZATION()

Make the initialization of the per-CPU data optional.

Change license to BSD-2-Clause according to file history and
re-licensing agreement.

Update #3053.

cpukit/Makefile.am

@@ -840,6 +840,7 @@ librtemscpu_a_SOURCES += score/src/coremsgwkspace.c
 librtemscpu_a_SOURCES += score/src/coremutexseize.c
 librtemscpu_a_SOURCES += score/src/percpu.c
 librtemscpu_a_SOURCES += score/src/percpuasm.c
+librtemscpu_a_SOURCES += score/src/percpudata.c
 librtemscpu_a_SOURCES += score/src/corerwlock.c
 librtemscpu_a_SOURCES += score/src/corerwlockobtainread.c
 librtemscpu_a_SOURCES += score/src/corerwlockobtainwrite.c

cpukit/include/rtems/score/percpudata.h

@@ -50,6 +50,20 @@ extern "C" {
 
 RTEMS_LINKER_RWSET_DECLARE( _Per_CPU_Data, char );
 
+/**
+ * @brief Translation units which define per-CPU items shall call this macro
+ *   exactly once at file scope.
+ */
+#ifdef RTEMS_SMP
+#define PER_CPU_DATA_NEED_INITIALIZATION() \
+  static const char * const _Per_CPU_Data_reference \
+  RTEMS_SECTION( ".rtemsroset.reference" ) RTEMS_USED = \
+  RTEMS_LINKER_SET_BEGIN( _Per_CPU_Data )
+#else
+#define PER_CPU_DATA_NEED_INITIALIZATION() \
+  RTEMS_LINKER_RWSET_DECLARE( _Per_CPU_Data, char )
+#endif
+
 /**
  * @brief Declares a per-CPU item of the specified type.
  *

cpukit/sapi/src/exinit.c

@@ -32,7 +32,6 @@
 #include <rtems/score/heap.h>
 #include <rtems/score/interr.h>
 #include <rtems/score/isr.h>
-#include <rtems/score/percpudata.h>
 #include <rtems/score/priority.h>
 #include <rtems/score/schedulerimpl.h>
 #include <rtems/score/smpimpl.h>
@@ -58,18 +57,6 @@ _Objects_Information_table[ OBJECTS_APIS_LAST + 1 ] = {
   &_POSIX_Objects[ 0 ]
 };
 
-RTEMS_LINKER_RWSET(
-  _Per_CPU_Data,
-#if defined(RTEMS_SMP)
-  /*
-   * In SMP configurations, prevent false cache line sharing of per-processor
-   * data with a proper alignment.
-   */
-  RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
-#endif
-  char
-);
-
 static void rtems_initialize_data_structures(void)
 {
   /*

cpukit/score/src/percpudata.c

@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup RTEMSScorePerCPUData
+ *
+ * @brief This source file contains the per-CPU data linker set and its system
+ *   initialization handler.
+ */
+
+/*
+ * Copyright (C) 2019, 2021 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/score/percpudata.h>
+#include <rtems/score/interr.h>
+#include <rtems/score/memory.h>
+#include <rtems/config.h>
+#include <rtems/sysinit.h>
+
+#include <string.h>
+
+RTEMS_LINKER_RWSET(
+  _Per_CPU_Data,
+#if defined(RTEMS_SMP)
+  /*
+   * In SMP configurations, prevent false cache line sharing of per-processor
+   * data with a proper alignment.
+   */
+  RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES )
+#endif
+  char
+);
+
+#if defined(RTEMS_SMP)
+static void _Per_CPU_Data_initialize( void )
+{
+  uintptr_t size;
+
+  size = RTEMS_LINKER_SET_SIZE( _Per_CPU_Data );
+
+  if ( size > 0 ) {
+    const Memory_Information *mem;
+    Per_CPU_Control          *cpu;
+    uint32_t                  cpu_index;
+    uint32_t                  cpu_max;
+
+    mem = _Memory_Get();
+    cpu = _Per_CPU_Get_by_index( 0 );
+    cpu->data = RTEMS_LINKER_SET_BEGIN( _Per_CPU_Data );
+
+    cpu_max = rtems_configuration_get_maximum_processors();
+
+    for ( cpu_index = 1 ; cpu_index < cpu_max ; ++cpu_index ) {
+      cpu = _Per_CPU_Get_by_index( cpu_index );
+      cpu->data = _Memory_Allocate( mem, size, CPU_CACHE_LINE_BYTES );
+
+      if( cpu->data == NULL ) {
+        _Internal_error( INTERNAL_ERROR_NO_MEMORY_FOR_PER_CPU_DATA );
+      }
+
+      memcpy( cpu->data, RTEMS_LINKER_SET_BEGIN( _Per_CPU_Data ), size);
+    }
+  }
+}
+
+RTEMS_SYSINIT_ITEM(
+  _Per_CPU_Data_initialize,
+  RTEMS_SYSINIT_PER_CPU_DATA,
+  RTEMS_SYSINIT_ORDER_MIDDLE
+);
+#endif

cpukit/score/src/smp.c

@@ -27,14 +27,9 @@
 
 #include <rtems/score/smpimpl.h>
 #include <rtems/score/assert.h>
-#include <rtems/score/memory.h>
-#include <rtems/score/percpudata.h>
 #include <rtems/score/schedulerimpl.h>
 #include <rtems/score/threadimpl.h>
 #include <rtems/config.h>
-#include <rtems/sysinit.h>
-
-#include <string.h>
 
 #if CPU_USE_DEFERRED_FP_SWITCH == TRUE
   #error "deferred FP switch not implemented for SMP"
@@ -264,40 +259,3 @@ void _SMP_Send_message_multicast(
     }
   }
 }
-
-static void _Per_CPU_Data_initialize( void )
-{
-  uintptr_t size;
-
-  size = RTEMS_LINKER_SET_SIZE( _Per_CPU_Data );
-
-  if ( size > 0 ) {
-    const Memory_Information *mem;
-    Per_CPU_Control          *cpu;
-    uint32_t                  cpu_index;
-    uint32_t                  cpu_max;
-
-    mem = _Memory_Get();
-    cpu = _Per_CPU_Get_by_index( 0 );
-    cpu->data = RTEMS_LINKER_SET_BEGIN( _Per_CPU_Data );
-
-    cpu_max = rtems_configuration_get_maximum_processors();
-
-    for ( cpu_index = 1 ; cpu_index < cpu_max ; ++cpu_index ) {
-      cpu = _Per_CPU_Get_by_index( cpu_index );
-      cpu->data = _Memory_Allocate( mem, size, CPU_CACHE_LINE_BYTES );
-
-      if( cpu->data == NULL ) {
-        _Internal_error( INTERNAL_ERROR_NO_MEMORY_FOR_PER_CPU_DATA );
-      }
-
-      memcpy( cpu->data, RTEMS_LINKER_SET_BEGIN( _Per_CPU_Data ), size);
-    }
-  }
-}
-
-RTEMS_SYSINIT_ITEM(
-  _Per_CPU_Data_initialize,
-  RTEMS_SYSINIT_PER_CPU_DATA,
-  RTEMS_SYSINIT_ORDER_MIDDLE
-);

spec/build/cpukit/librtemscpu.yml

@@ -1454,6 +1454,7 @@ source:
 - cpukit/score/src/once.c
 - cpukit/score/src/percpu.c
 - cpukit/score/src/percpuasm.c
+- cpukit/score/src/percpudata.c
 - cpukit/score/src/pheapallocate.c
 - cpukit/score/src/pheapextend.c
 - cpukit/score/src/pheapfree.c

testsuites/smptests/smpfatal09/init.c

@@ -36,6 +36,8 @@
 
 #include <tmacros.h>
 
+PER_CPU_DATA_NEED_INITIALIZATION();
+
 static PER_CPU_DATA_ITEM(int, i) = 123;
 
 const char rtems_test_name[] = "SMPFATAL 9";

testsuites/sptests/sppercpudata01/init.c

@@ -25,6 +25,8 @@
 
 const char rtems_test_name[] = "SPPERCPUDATA 1";
 
+PER_CPU_DATA_NEED_INITIALIZATION();
+
 static RTEMS_ALIGNED(CPU_HEAP_ALIGNMENT)
   PER_CPU_DATA_ITEM(unsigned char, c) = 1;