score: Add flexible per-CPU data

Update #3507.

1 files changed, 104 insertions, 0 deletions

diff --git a/cpukit/include/rtems/score/percpudata.h b/cpukit/include/rtems/score/percpudata.h
new file mode 100644
index 0000000000..3de99566ad
--- /dev/null
+++ b/cpukit/include/rtems/score/percpudata.h
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2018 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#ifndef _RTEMS_SCORE_PERCPUDATA_H
+#define _RTEMS_SCORE_PERCPUDATA_H
+
+#include <rtems/score/percpu.h>
+#include <rtems/linkersets.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * @defgroup PerCPUData Flexible Per-CPU Data
+ *
+ * @ingroup PerCPU
+ *
+ * Provides the definition of custom per-CPU items.  The items are collected in
+ * a special linker set.  During system initialization the content of the
+ * linker set is duplicated for all secondary processors using memory allocated
+ * from the workspace.  The begin and end of the per-CPU data area is cache
+ * line aligned (CPU_CACHE_LINE_BYTES).
+ *
+ * @{
+ */
+
+RTEMS_LINKER_RWSET_DECLARE( _Per_CPU_Data, char );
+
+/**
+ * @brief Declares a per-CPU item of the specified type.
+ *
+ * Items declared with this macro have external linkage.
+ *
+ * @param type The type of the item.
+ * @param item The designator of the item.
+ */
+#define PER_CPU_DATA_ITEM_DECLARE( type, item ) \
+  RTEMS_LINKER_RWSET_ITEM_DECLARE( _Per_CPU_Data, type, item )
+
+/**
+ * @brief Defines a per-CPU item of the specified type.
+ *
+ * @param type The type of the item.
+ * @param item The designator of the item.
+ */
+#define PER_CPU_DATA_ITEM( type, item ) \
+  RTEMS_LINKER_RWSET_ITEM( _Per_CPU_Data, type, item )
+
+/**
+ * @brief Returns the offset of the per-CPU item to the begin of the per-CPU
+ * data area.
+ *
+ * @param item The designator of the item.
+ */
+#define PER_CPU_DATA_OFFSET( item ) \
+  ( (uintptr_t) &_Linker_set__Per_CPU_Data_##item \
+    - (uintptr_t) RTEMS_LINKER_SET_BEGIN( _Per_CPU_Data ) )
+
+/**
+ * @brief Returns a pointer of the specified type to the per-CPU item at the
+ * specified offset for the specified processor.
+ *
+ * @param cpu The processor of the item.
+ * @param type The type of the item.
+ * @param offset The offset of the item.
+ */
+#define PER_CPU_DATA_GET_BY_OFFSET( cpu, type, offset ) \
+  (type *) ( cpu->data + offset )
+
+/**
+ * @brief Returns a pointer of the specified type to the specified per-CPU item
+ * for the specified processor.
+ *
+ * @param cpu The processor of the item.
+ * @param type The type of the item.
+ * @param item The designator of the item.
+ */
+#ifdef RTEMS_SMP
+#define PER_CPU_DATA_GET( cpu, type, item ) \
+  PER_CPU_DATA_GET_BY_OFFSET( cpu, type, PER_CPU_DATA_OFFSET( item ) )
+#else
+#define PER_CPU_DATA_GET( cpu, type, item ) \
+  &_Linker_set__Per_CPU_Data_##item
+#endif
+
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* _RTEMS_SCORE_PERCPUDATA_H */