/*
* Copyright (c) 2014-2015 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.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/score/cpuopts.h>
#include <rtems/score/isrlevel.h>
/*
* This file is a dirty hack. A proper solution would be to add RTEMS support
* for libatomic in GCC (see also libatomic/configure.tgt).
*/
#if defined(RTEMS_SMP)
static volatile uint32_t _SPARCV8_The_one_lock;
static inline uint32_t _SPARCV8_Atomic_swap(
volatile uint32_t *address,
uint32_t value
)
{
asm volatile (
"swap [%2], %0"
: "=r" (value)
: "0" (value), "r" (address)
: "memory"
);
return value;
}
#endif
static ISR_Level _SPARCV8_Acquire_the_one_lock( void )
{
ISR_Level level;
_ISR_Disable_without_giant( level );
#if defined(RTEMS_SMP)
do {
while ( _SPARCV8_The_one_lock ) {
/* Wait */
}
} while ( _SPARCV8_Atomic_swap( &_SPARCV8_The_one_lock, 1 ) );
#endif
return level;
}
static void _SPARCV8_Release_the_one_lock( ISR_Level level )
{
#if defined(RTEMS_SMP)
_SPARCV8_The_one_lock = 0;
#endif
_ISR_Enable_without_giant( level );
}
uint8_t __atomic_exchange_1( uint8_t *mem, uint8_t val, int model )
{
uint8_t prev;
ISR_Level level;
level = _SPARCV8_Acquire_the_one_lock();
prev = *mem;
*mem = val;
_SPARCV8_Release_the_one_lock( level );
return prev;
}
/*
* In order to get rid of the warning "conflicting types for built-in function
* '__atomic_compare_exchange_4' [enabled by default]", you must port libatomic
* to SPARC/RTEMS. The libatomic is provided by GCC.
*/
uint32_t __atomic_exchange_4( uint32_t *mem, uint32_t val, int model )
{
uint32_t prev;
ISR_Level level;
level = _SPARCV8_Acquire_the_one_lock();
prev = *mem;
*mem = val;
_SPARCV8_Release_the_one_lock( level );
return prev;
}
/*
* You get probably a warning here which can be ignored: "warning: conflicting
* types for built-in function '__atomic_compare_exchange_4' [enabled by
* default]"
*/
bool __atomic_compare_exchange_4(
uint32_t *mem,
uint32_t *expected,
uint32_t desired,
int success,
int failure
)
{
bool equal;
ISR_Level level;
uint32_t actual;
level = _SPARCV8_Acquire_the_one_lock();
actual = *mem;
equal = ( actual == *expected );
if ( equal ) {
*mem = desired;
} else {
*expected = actual;
}
_SPARCV8_Release_the_one_lock( level );
return equal;
}
uint32_t __atomic_fetch_add_4( uint32_t *mem, uint32_t val, int model )
{
uint32_t prev;
ISR_Level level;
level = _SPARCV8_Acquire_the_one_lock();
prev = *mem;
*mem = prev + val;
_SPARCV8_Release_the_one_lock( level );
return prev;
}
uint32_t __atomic_fetch_sub_4( uint32_t *mem, uint32_t val, int model )
{
uint32_t prev;
ISR_Level level;
level = _SPARCV8_Acquire_the_one_lock();
prev = *mem;
*mem = prev - val;
_SPARCV8_Release_the_one_lock( level );
return prev;
}
uint32_t __atomic_fetch_and_4( uint32_t *mem, uint32_t val, int model )
{
uint32_t prev;
ISR_Level level;
level = _SPARCV8_Acquire_the_one_lock();
prev = *mem;
*mem = prev & val;
_SPARCV8_Release_the_one_lock( level );
return prev;
}
uint32_t __atomic_fetch_or_4( uint32_t *mem, uint32_t val, int model )
{
uint32_t prev;
ISR_Level level;
level = _SPARCV8_Acquire_the_one_lock();
prev = *mem;
*mem = prev | val;
_SPARCV8_Release_the_one_lock( level );
return prev;
}
uint32_t __atomic_fetch_xor_4( uint32_t *mem, uint32_t val, int model )
{
uint32_t prev;
ISR_Level level;
level = _SPARCV8_Acquire_the_one_lock();
prev = *mem;
*mem = prev ^ val;
_SPARCV8_Release_the_one_lock( level );
return prev;
}