/* 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