/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @ingroup RTEMSScoreISRLocks
*
* @brief This header file provides the interfaces of the
* @ref RTEMSScoreISRLocks.
*/
/*
* Copyright (C) 2013, 2019 embedded brains GmbH & Co. KG
*
* 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.
*/
#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 RTEMSScoreISRLocks ISR Locks
*
* @ingroup RTEMSScoreISR
*
* @brief This group contains the ISR locks implementation.
*
* The ISR locks are low-level locks to protect critical sections accessed by
* threads and interrupt service routines.
*
* In uniprocessor configurations the ISR locks degrade to simple ISR
* disable/enable sequences. No additional storage or objects are required.
*
* This synchronization primitive is supported in 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
#if defined( RTEMS_PROFILING )
/**
* @brief The last interrupt disable instant in CPU counter ticks.
*/
CPU_Counter_ticks ISR_disable_instant;
#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 Sets the ISR level in the ISR lock context.
*
* @param[out] context The ISR lock context.
* @param level The ISR level.
*/
static inline void _ISR_lock_Context_set_level(
ISR_lock_Context *context,
ISR_Level level
)
{
#if defined( RTEMS_SMP )
context->Lock_context.isr_level = level;
#else
context->isr_level = level;
#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 Sets the name of an ISR lock.
*
* @param[out] _lock The ISR lock control.
* @param _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_Set_name( _lock, _name ) \
_SMP_lock_Set_name( &( _lock )->Lock, _name )
#else
#define _ISR_lock_Set_name( _lock, _name )
#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_Local_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_Local_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 ) \
do { \
_Assert( _ISR_Get_level() != 0 ); \
_SMP_lock_Acquire( \
&( _lock )->Lock, \
&( _context )->Lock_context \
); \
} while ( 0 )
#else
#define _ISR_lock_Acquire( _lock, _context ) \
do { (void) _context; } while ( 0 )
#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 ) \
do { (void) _context; } while ( 0 )
#endif
/**
* @brief Acquires an ISR lock inside an ISR disabled section (inline).
*
* @see _ISR_lock_Acquire().
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_Acquire_inline( _lock, _context ) \
do { \
_Assert( _ISR_Get_level() != 0 ); \
_SMP_lock_Acquire_inline( \
&( _lock )->Lock, \
&( _context )->Lock_context \
); \
} while ( 0 )
#else
#define _ISR_lock_Acquire_inline( _lock, _context ) \
do { (void) _context; } while ( 0 )
#endif
/**
* @brief Releases an ISR lock inside an ISR disabled section (inline).
*
* @see _ISR_lock_Release().
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_Release_inline( _lock, _context ) \
_SMP_lock_Release_inline( \
&( _lock )->Lock, \
&( _context )->Lock_context \
)
#else
#define _ISR_lock_Release_inline( _lock, _context ) \
do { (void) _context; } while ( 0 )
#endif
#if defined( RTEMS_DEBUG )
/**
* @brief Returns true, if the ISR lock is owned by the current processor,
* otherwise false.
*
* On uni-processor configurations, this function returns true, if interrupts
* are disabled, otherwise false.
*
* @param[in] _lock The ISR lock control.
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_Is_owner( _lock ) \
_SMP_lock_Is_owner( &( _lock )->Lock )
#else
#define _ISR_lock_Is_owner( _lock ) \
( _ISR_Get_level() != 0 )
#endif
#endif
#if defined( RTEMS_PROFILING )
#define _ISR_lock_ISR_disable_profile( _context ) \
( _context )->ISR_disable_instant = _CPU_Counter_read();
#else
#define _ISR_lock_ISR_disable_profile( _context )
#endif
/**
* @brief Disables interrupts and saves the previous interrupt state in the ISR
* lock context.
*
* This function can be used in thread and interrupt context.
*
* @param[in] _context The local ISR lock context to store the interrupt state.
*
* @see _ISR_lock_ISR_enable().
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_ISR_disable( _context ) \
do { \
_ISR_Local_disable( ( _context )->Lock_context.isr_level ); \
_ISR_lock_ISR_disable_profile( _context ) \
} while ( 0 )
#else
#define _ISR_lock_ISR_disable( _context ) \
do { \
_ISR_Local_disable( ( _context )->isr_level ); \
_ISR_lock_ISR_disable_profile( _context ) \
} while ( 0 )
#endif
/**
* @brief Restores the saved interrupt state of the ISR lock context.
*
* This function can be used in thread and interrupt context.
*
* @param[in] _context The local ISR lock context containing the saved
* interrupt state.
*
* @see _ISR_lock_ISR_disable().
*/
#if defined( RTEMS_SMP )
#define _ISR_lock_ISR_enable( _context ) \
_ISR_Local_enable( ( _context )->Lock_context.isr_level )
#else
#define _ISR_lock_ISR_enable( _context ) \
_ISR_Local_enable( ( _context )->isr_level )
#endif
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* _RTEMS_SCORE_ISR_LOCK_H */
