/* 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