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- /* 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
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