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/**
* @file
*
* @ingroup RTEMSScorePerCPUData
*
* @brief This header file provides the interfaces of the
* @ref RTEMSScorePerCPUData.
*/
/*
* 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 RTEMSScorePerCPUData Flexible Per-CPU Data
*
* @ingroup RTEMSScorePerCPU
*
* @brief This group contains the implementation to support flexible per-CPU
* data.
*
* Macros to define custom per-CPU items are provided. 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 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.
*
* 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.
*/
#ifdef RTEMS_SMP
#define PER_CPU_DATA_GET_BY_OFFSET( cpu, type, offset ) \
(type *) ( cpu->data + offset )
#else
#define PER_CPU_DATA_GET_BY_OFFSET( cpu, type, offset ) \
(type *) ( (uintptr_t) RTEMS_LINKER_SET_BEGIN( _Per_CPU_Data ) + offset ), \
(void) cpu
#endif
/**
* @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, (void) cpu
#endif
/** @} */
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* _RTEMS_SCORE_PERCPUDATA_H */
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