/**
* @file
*
* @ingroup ScoreISRLocks
*
* @brief ISR Locks
*/
/*
* Copyright (c) 2013 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.com/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.
*/
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 Initializer for static initialization of ISR locks.
*/
#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,out] lock The ISR lock control.
* @param[in] name The name for the ISR lock. This name must be persistent
* throughout the life time of this lock.
*/
static inline void _ISR_lock_Initialize(
ISR_lock_Control *lock,
const char *name
)
{
#if defined( RTEMS_SMP )
_SMP_lock_Initialize( &lock->lock, name );
#else
(void) lock;
(void) name;
#endif
}
/**
* @brief Destroys an ISR lock.
*
* Concurrent destruction leads to unpredictable results.
*
* @param[in,out] lock The ISR lock control.
*/
static inline void _ISR_lock_Destroy( ISR_lock_Control *lock )
{
#if defined( RTEMS_SMP )
_SMP_lock_Destroy( &lock->lock );
#else
(void) 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,out] lock The ISR lock control.
* @param[in,out] context The local ISR lock context for an acquire and release
* pair.
*
* @see _ISR_lock_Release_and_ISR_enable().
*/
static inline void _ISR_lock_ISR_disable_and_acquire(
ISR_lock_Control *lock,
ISR_lock_Context *context
)
{
#if defined( RTEMS_SMP )
_SMP_lock_ISR_disable_and_acquire( &lock->lock, &context->lock_context );
#else
(void) lock;
_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,out] lock The ISR lock control.
* @param[in,out] context The local ISR lock context for an acquire and release
* pair.
*
* @see _ISR_lock_ISR_disable_and_acquire().
*/
static inline void _ISR_lock_Release_and_ISR_enable(
ISR_lock_Control *lock,
ISR_lock_Context *context
)
{
#if defined( RTEMS_SMP )
_SMP_lock_Release_and_ISR_enable( &lock->lock, &context->lock_context );
#else
(void) lock;
_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,out] lock The ISR lock control.
* @param[in,out] context The local ISR lock context for an acquire and release
* pair.
*
* @see _ISR_lock_Release().
*/
static inline void _ISR_lock_Acquire(
ISR_lock_Control *lock,
ISR_lock_Context *context
)
{
#if defined( RTEMS_SMP )
_SMP_lock_Acquire( &lock->lock, &context->lock_context );
#else
(void) lock;
(void) 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,out] lock The ISR lock control.
* @param[in,out] context The local ISR lock context for an acquire and release
* pair.
*
* @see _ISR_lock_Acquire().
*/
static inline void _ISR_lock_Release(
ISR_lock_Control *lock,
ISR_lock_Context *context
)
{
#if defined( RTEMS_SMP )
_SMP_lock_Release( &lock->lock, &context->lock_context );
#else
(void) lock;
(void) context;
#endif
}
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* _RTEMS_SCORE_ISR_LOCK_H */
