/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_SYNC_BITOPS_H__
#define __ASM_SYNC_BITOPS_H__
#include <asm/bitops.h>
/* sync_bitops functions are equivalent to the SMP implementation of the
* original functions, independently from CONFIG_SMP being defined.
*
* We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But
* under Xen you might be communicating with a completely external entity
* who might be on another CPU (e.g. two uniprocessor guests communicating
* via event channels and grant tables). So we need a variant of the bit
* ops which are SMP safe even on a UP kernel.
*/
/*
* Unordered
*/
#define sync_set_bit(nr, p) _set_bit(nr, p)
#define sync_clear_bit(nr, p) _clear_bit(nr, p)
#define sync_change_bit(nr, p) _change_bit(nr, p)
#define sync_test_bit(nr, addr) test_bit(nr, addr)
/*
* Fully ordered
*/
int _sync_test_and_set_bit(int nr, volatile unsigned long * p);
#define sync_test_and_set_bit(nr, p) _sync_test_and_set_bit(nr, p)
int _sync_test_and_clear_bit(int nr, volatile unsigned long * p);
#define sync_test_and_clear_bit(nr, p) _sync_test_and_clear_bit(nr, p)
int _sync_test_and_change_bit(int nr, volatile unsigned long * p);
#define sync_test_and_change_bit(nr, p) _sync_test_and_change_bit(nr, p)
#define arch_sync_cmpxchg(ptr, old, new) \
({ \
__typeof__(*(ptr)) __ret; \
__smp_mb__before_atomic(); \
__ret = arch_cmpxchg_relaxed((ptr), (old), (new)); \
__smp_mb__after_atomic(); \
__ret; \
})
#endif
