1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_GENERIC_BITOPS_ATOMIC_H_
3 #define _ASM_GENERIC_BITOPS_ATOMIC_H_
4 
5 #include <linux/atomic.h>
6 #include <linux/compiler.h>
7 #include <asm/barrier.h>
8 
9 /*
10  * Implementation of atomic bitops using atomic-fetch ops.
11  * See Documentation/atomic_bitops.txt for details.
12  */
13 
14 static inline void set_bit(unsigned int nr, volatile unsigned long *p)
15 {
16 	p += BIT_WORD(nr);
17 	atomic_long_or(BIT_MASK(nr), (atomic_long_t *)p);
18 }
19 
20 static inline void clear_bit(unsigned int nr, volatile unsigned long *p)
21 {
22 	p += BIT_WORD(nr);
23 	atomic_long_andnot(BIT_MASK(nr), (atomic_long_t *)p);
24 }
25 
26 static inline void change_bit(unsigned int nr, volatile unsigned long *p)
27 {
28 	p += BIT_WORD(nr);
29 	atomic_long_xor(BIT_MASK(nr), (atomic_long_t *)p);
30 }
31 
32 static inline int test_and_set_bit(unsigned int nr, volatile unsigned long *p)
33 {
34 	long old;
35 	unsigned long mask = BIT_MASK(nr);
36 
37 	p += BIT_WORD(nr);
38 	if (READ_ONCE(*p) & mask)
39 		return 1;
40 
41 	old = atomic_long_fetch_or(mask, (atomic_long_t *)p);
42 	return !!(old & mask);
43 }
44 
45 static inline int test_and_clear_bit(unsigned int nr, volatile unsigned long *p)
46 {
47 	long old;
48 	unsigned long mask = BIT_MASK(nr);
49 
50 	p += BIT_WORD(nr);
51 	if (!(READ_ONCE(*p) & mask))
52 		return 0;
53 
54 	old = atomic_long_fetch_andnot(mask, (atomic_long_t *)p);
55 	return !!(old & mask);
56 }
57 
58 static inline int test_and_change_bit(unsigned int nr, volatile unsigned long *p)
59 {
60 	long old;
61 	unsigned long mask = BIT_MASK(nr);
62 
63 	p += BIT_WORD(nr);
64 	old = atomic_long_fetch_xor(mask, (atomic_long_t *)p);
65 	return !!(old & mask);
66 }
67 
68 #endif /* _ASM_GENERIC_BITOPS_ATOMIC_H */
69