xref: /OK3568_Linux_fs/kernel/arch/arm/include/asm/sync_bitops.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef __ASM_SYNC_BITOPS_H__
3*4882a593Smuzhiyun #define __ASM_SYNC_BITOPS_H__
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun #include <asm/bitops.h>
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun /* sync_bitops functions are equivalent to the SMP implementation of the
8*4882a593Smuzhiyun  * original functions, independently from CONFIG_SMP being defined.
9*4882a593Smuzhiyun  *
10*4882a593Smuzhiyun  * We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But
11*4882a593Smuzhiyun  * under Xen you might be communicating with a completely external entity
12*4882a593Smuzhiyun  * who might be on another CPU (e.g. two uniprocessor guests communicating
13*4882a593Smuzhiyun  * via event channels and grant tables). So we need a variant of the bit
14*4882a593Smuzhiyun  * ops which are SMP safe even on a UP kernel.
15*4882a593Smuzhiyun  */
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun #define sync_set_bit(nr, p)		_set_bit(nr, p)
18*4882a593Smuzhiyun #define sync_clear_bit(nr, p)		_clear_bit(nr, p)
19*4882a593Smuzhiyun #define sync_change_bit(nr, p)		_change_bit(nr, p)
20*4882a593Smuzhiyun #define sync_test_and_set_bit(nr, p)	_test_and_set_bit(nr, p)
21*4882a593Smuzhiyun #define sync_test_and_clear_bit(nr, p)	_test_and_clear_bit(nr, p)
22*4882a593Smuzhiyun #define sync_test_and_change_bit(nr, p)	_test_and_change_bit(nr, p)
23*4882a593Smuzhiyun #define sync_test_bit(nr, addr)		test_bit(nr, addr)
24*4882a593Smuzhiyun #define sync_cmpxchg			cmpxchg
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun #endif
28