/**
* @file
*
* @ingroup ScoreISRLocks
*
* @brief ISR Locks
*/
/*
* Copyright (c) 2013-2015 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_ISR_LOCK_H
#define _RTEMS_SCORE_ISR_LOCK_H
#include <rtems/score/isrlevel.h>
#include <rtems/score/smplock.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup ScoreISRLocks ISR Locks
*
* @ingroup ScoreISR
*
* @brief Low-level lock to protect critical sections accessed by threads and
* interrupt service routines.
*
* On single processor configurations the ISR locks degrade to simple ISR
* disable/enable sequences. No additional storage or objects are required.
*
* This synchronization primitive is supported on SMP configurations. Here SMP
* locks are used.
*
* @{
*/
/**
* @brief ISR lock control.
*
* @warning Empty structures are implementation-defined in C. GCC gives them a
* size of zero. In C++ empty structures have a non-zero size.
*/
typedef struct {
#if defined( RTEMS_SMP )
SMP_lock_Control Lock;
#endif
} ISR_lock_Control;
/**
* @brief Local ISR lock context for acquire and release pairs.
*/
typedef struct {
#if defined( RTEMS_SMP )
SMP_lock_Context Lock_context;
#else
ISR_Level isr_level;
#endif
} ISR_lock_Context;
/**
* @brief Defines an ISR lock member.
*
* Do not add a ';' after this macro.
*
* @param _designator The designator for the interrupt lock.
*/
#if defined( RTEMS_SMP )
#define ISR_LOCK_MEMBER( _designator ) ISR_lock_Control _designator;
#else
#define ISR_LOCK_MEMBER( _designator )
#endif
/**
* @brief Declares an ISR lock variable.
*
* Do not add a ';' after this macro.
*
* @param _qualifier The qualifier for the interrupt lock, e.g. extern.
* @param _designator The designator for the interrupt lock.
*/
#if defined( RTEMS_SMP )
#define ISR_LOCK_DECLARE( _qualifier, _designator ) \
_qualifier ISR_lock_Control _designator;
#else
#define ISR_LOCK_DECLARE( _qualifier, _designator )
#endif
/**
* @brief Defines an ISR lock variable.
*
* Do not add a ';' after this macro.
*
* @param _qualifier The qualifier for the interrupt lock, e.g. static.
* @param _designator The designator for the interrupt lock.
* @param _name The name for the interrupt lock. It must be a string. The
* name is only used if profiling is enabled.
*/
#if defined( RTEMS_SMP )
#define ISR_LOCK_DEFINE( _qualifier, _designator, _name ) \
_qualifier ISR_lock_Control _designator = { SMP_LOCK_INITIALIZER( _name ) };
#else
#define ISR_LOCK_DEFINE( _qualifier, _designator, _name )
#endif
/**
* @brief Defines an ISR lock variable reference.
*
* Do not add a ';' after this macro.
*
* @param _designator The designator for the interrupt lock reference.
* @param _target The target for the interrupt lock reference.
*/
#if defined( RTEMS_SMP )
#define ISR_LOCK_REFERENCE( _designator, _target ) \
ISR_lock_Control *_designator = _target;
#else
#define ISR_LOCK_REFERENCE( _designator, _target )
#endif
/**
* @brief Initializer for static initialization of ISR locks.
*
* @param _name The name for the interrupt lock. It must be a string. The
* name is only used if profiling is enabled.
*/
#if defined( RTEMS_SMP )
#define ISR_LOCK_INITIALIZER( _name ) \
{ SMP_LOCK_INITIALIZER( _name ) }
#else
#define ISR_LOCK_INITIALIZER( _name ) \
{ }
#endif
/**
* @brief Initializes an ISR lock.
*
* Concurrent initialization leads to unpredictable results.
*
* @param[in] _lock The ISR lock control.
* @param[in] _name The name for the ISR lock. This name must be a
* string persistent throughout the life time of this lock. The name is only
* used if profiling is enabled.
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_Initialize( _lock, _name ) \
_SMP_lock_Initialize( &( _lock )->Lock, _name )
#else
#define _ISR_lock_Initialize( _lock, _name )
#endif
/**
* @brief Destroys an ISR lock.
*
* Concurrent destruction leads to unpredictable results.
*
* @param[in] _lock The ISR lock control.
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_Destroy( _lock ) \
_SMP_lock_Destroy( &( _lock )->Lock )
#else
#define _ISR_lock_Destroy( _lock )
#endif
/**
* @brief Acquires an ISR lock.
*
* Interrupts will be disabled. On SMP configurations this function acquires
* an SMP lock.
*
* This function can be used in thread and interrupt context.
*
* @param[in] _lock The ISR lock control.
* @param[in] context The local ISR lock context for an acquire and release
* pair.
*
* @see _ISR_lock_Release_and_ISR_enable().
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_ISR_disable_and_acquire( _lock, _context ) \
_SMP_lock_ISR_disable_and_acquire( \
&( _lock )->Lock, \
&( _context )->Lock_context \
)
#else
#define _ISR_lock_ISR_disable_and_acquire( _lock, _context ) \
_ISR_Disable( ( _context )->isr_level )
#endif
/**
* @brief Releases an ISR lock.
*
* The interrupt status will be restored. On SMP configurations this function
* releases an SMP lock.
*
* This function can be used in thread and interrupt context.
*
* @param[in] _lock The ISR lock control.
* @param[in] _context The local ISR lock context for an acquire and release
* pair.
*
* @see _ISR_lock_ISR_disable_and_acquire().
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_Release_and_ISR_enable( _lock, _context ) \
_SMP_lock_Release_and_ISR_enable( \
&( _lock )->Lock, \
&( _context )->Lock_context \
)
#else
#define _ISR_lock_Release_and_ISR_enable( _lock, _context ) \
_ISR_Enable( ( _context )->isr_level )
#endif
/**
* @brief Acquires an ISR lock inside an ISR disabled section.
*
* The interrupt status will remain unchanged. On SMP configurations this
* function acquires an SMP lock.
*
* In case the executing context can be interrupted by higher priority
* interrupts and these interrupts enter the critical section protected by this
* lock, then the result is unpredictable.
*
* @param[in] _lock The ISR lock control.
* @param[in] _context The local ISR lock context for an acquire and release
* pair.
*
* @see _ISR_lock_Release().
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_Acquire( _lock, _context ) \
_SMP_lock_Acquire( \
&( _lock )->Lock, \
&( _context )->Lock_context \
)
#else
#define _ISR_lock_Acquire( _lock, _context )
#endif
/**
* @brief Releases an ISR lock inside an ISR disabled section.
*
* The interrupt status will remain unchanged. On SMP configurations this
* function releases an SMP lock.
*
* @param[in] _lock The ISR lock control.
* @param[in] _context The local ISR lock context for an acquire and release
* pair.
*
* @see _ISR_lock_Acquire().
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_Release( _lock, _context ) \
_SMP_lock_Release( \
&( _lock )->Lock, \
&( _context )->Lock_context \
)
#else
#define _ISR_lock_Release( _lock, _context )
#endif
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* _RTEMS_SCORE_ISR_LOCK_H */
