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/*
* COPYRIGHT (c) 1989-2011.
* On-Line Applications Research Corporation (OAR).
*
* 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.
*
* $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/system.h>
#include <rtems/score/smplock.h>
#include <rtems/score/smp.h>
#if defined (RTEMS_DEBUG)
#include <rtems/bspIo.h>
#endif
void _SMP_lock_spinlock_simple_Initialize(
SMP_lock_spinlock_simple_Control *lock
)
{
*lock = 0;
}
ISR_Level _SMP_lock_spinlock_simple_Obtain(
SMP_lock_spinlock_simple_Control *lock
)
{
ISR_Level level;
uint32_t value = 1;
uint32_t previous;
/* Note: Disable provides an implicit memory barrier. */
_ISR_Disable( level );
do {
SMP_CPU_SWAP( lock, value, previous );
} while (previous == 1);
return level;
}
void _SMP_lock_spinlock_simple_Release(
SMP_lock_spinlock_simple_Control *lock,
ISR_Level level
)
{
*lock = 0;
_ISR_Enable( level );
}
void _SMP_lock_spinlock_nested_Initialize(
SMP_lock_spinlock_nested_Control *lock
)
{
lock->count = 0;
lock->cpu_id = 0;
}
ISR_Level _SMP_lock_spinlock_nested_Obtain(
SMP_lock_spinlock_nested_Control *lock
)
{
ISR_Level level = 0;
uint32_t value = 1;
uint32_t previous;
int cpu_id;
/* Note: Disable provides an implicit memory barrier. */
_ISR_Disable( level );
cpu_id = bsp_smp_processor_id();
/* Deal with nested calls from one cpu */
if ( (lock->count > 0) && (cpu_id == lock->cpu_id) ) {
lock->count++;
return level;
}
do {
SMP_CPU_SWAP( lock, value, previous );
} while (previous == 1);
lock->count++;
lock->cpu_id = cpu_id;
return level;
}
void _SMP_lock_spinlock_nested_Release(
SMP_lock_spinlock_nested_Control *lock,
ISR_Level level
)
{
#if defined(RTEMS_DEBUG)
if ( lock->count == 0 )
printk ("Releasing spinlock when count is already zero?!?!\n");
#endif
lock->count--;
_ISR_Enable( level );
}
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