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/*
* Copyright (c) 2016 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.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <machine/_libatomic.h>
#include <rtems/score/apimutex.h>
#include <rtems/score/atomic.h>
#include <rtems/score/isrlevel.h>
#if defined(RTEMS_SMP)
/*
* For real SMP targets this is not useful. The main purpose is support for
* testing on simulators like SIS.
*/
static Atomic_Flag _Libatomic_The_one_lock = ATOMIC_INITIALIZER_FLAG;
#endif
__uint32_t _Libatomic_Protect_start( void *ptr )
{
ISR_Level isr_level;
(void) ptr;
_ISR_Local_disable( isr_level );
#if defined(RTEMS_SMP)
while (
_Atomic_Flag_test_and_set( &_Libatomic_The_one_lock, ATOMIC_ORDER_SEQ_CST )
) {
/* Next try. Yes, a TAS spin lock implementation is stupid. */
}
#endif
return isr_level;
}
void _Libatomic_Protect_end( void *ptr, __uint32_t isr_level )
{
(void) ptr;
#if defined(RTEMS_SMP)
_Atomic_Flag_clear( &_Libatomic_The_one_lock, ATOMIC_ORDER_SEQ_CST );
#endif
_ISR_Local_enable( isr_level );
}
static API_Mutex_Control _Libatomic_Mutex =
API_MUTEX_INITIALIZER( "_Libatomic" );
void _Libatomic_Lock_n( void *ptr, __size_t n )
{
(void) ptr;
(void) n;
_API_Mutex_Lock( &_Libatomic_Mutex );
}
void _Libatomic_Unlock_n( void *ptr, __size_t n )
{
(void) ptr;
(void) n;
_API_Mutex_Unlock( &_Libatomic_Mutex );
}
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