1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_SYNC_BITOPS_H__
3 #define __ASM_SYNC_BITOPS_H__
4 
5 #include <asm/bitops.h>
6 #include <asm/cmpxchg.h>
7 
8 /* sync_bitops functions are equivalent to the SMP implementation of the
9  * original functions, independently from CONFIG_SMP being defined.
10  *
11  * We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But
12  * under Xen you might be communicating with a completely external entity
13  * who might be on another CPU (e.g. two uniprocessor guests communicating
14  * via event channels and grant tables). So we need a variant of the bit
15  * ops which are SMP safe even on a UP kernel.
16  */
17 
18 #define sync_set_bit(nr, p)            set_bit(nr, p)
19 #define sync_clear_bit(nr, p)          clear_bit(nr, p)
20 #define sync_change_bit(nr, p)         change_bit(nr, p)
21 #define sync_test_and_set_bit(nr, p)   test_and_set_bit(nr, p)
22 #define sync_test_and_clear_bit(nr, p) test_and_clear_bit(nr, p)
23 #define sync_test_and_change_bit(nr, p)        test_and_change_bit(nr, p)
24 #define sync_test_bit(nr, addr)                test_bit(nr, addr)
25 #define sync_cmpxchg                   cmpxchg
26 
27 #endif
28