1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_GENERIC_LOCAL64_H
3 #define _ASM_GENERIC_LOCAL64_H
4
5 #include <linux/percpu.h>
6 #include <asm/types.h>
7
8 /*
9 * A signed long type for operations which are atomic for a single CPU.
10 * Usually used in combination with per-cpu variables.
11 *
12 * This is the default implementation, which uses atomic64_t. Which is
13 * rather pointless. The whole point behind local64_t is that some processors
14 * can perform atomic adds and subtracts in a manner which is atomic wrt IRQs
15 * running on this CPU. local64_t allows exploitation of such capabilities.
16 */
17
18 /* Implement in terms of atomics. */
19
20 #if BITS_PER_LONG == 64
21
22 #include <asm/local.h>
23
24 typedef struct {
25 local_t a;
26 } local64_t;
27
28 #define LOCAL64_INIT(i) { LOCAL_INIT(i) }
29
30 #define local64_read(l) local_read(&(l)->a)
31 #define local64_set(l,i) local_set((&(l)->a),(i))
32 #define local64_inc(l) local_inc(&(l)->a)
33 #define local64_dec(l) local_dec(&(l)->a)
34 #define local64_add(i,l) local_add((i),(&(l)->a))
35 #define local64_sub(i,l) local_sub((i),(&(l)->a))
36
37 #define local64_sub_and_test(i, l) local_sub_and_test((i), (&(l)->a))
38 #define local64_dec_and_test(l) local_dec_and_test(&(l)->a)
39 #define local64_inc_and_test(l) local_inc_and_test(&(l)->a)
40 #define local64_add_negative(i, l) local_add_negative((i), (&(l)->a))
41 #define local64_add_return(i, l) local_add_return((i), (&(l)->a))
42 #define local64_sub_return(i, l) local_sub_return((i), (&(l)->a))
43 #define local64_inc_return(l) local_inc_return(&(l)->a)
44
45 static inline s64 local64_cmpxchg(local64_t *l, s64 old, s64 new)
46 {
47 return local_cmpxchg(&l->a, old, new);
48 }
49
50 static inline bool local64_try_cmpxchg(local64_t *l, s64 *old, s64 new)
51 {
52 return local_try_cmpxchg(&l->a, (long *)old, new);
53 }
54
55 #define local64_xchg(l, n) local_xchg((&(l)->a), (n))
56 #define local64_add_unless(l, _a, u) local_add_unless((&(l)->a), (_a), (u))
57 #define local64_inc_not_zero(l) local_inc_not_zero(&(l)->a)
58
59 /* Non-atomic variants, ie. preemption disabled and won't be touched
60 * in interrupt, etc. Some archs can optimize this case well. */
61 #define __local64_inc(l) local64_set((l), local64_read(l) + 1)
62 #define __local64_dec(l) local64_set((l), local64_read(l) - 1)
63 #define __local64_add(i,l) local64_set((l), local64_read(l) + (i))
64 #define __local64_sub(i,l) local64_set((l), local64_read(l) - (i))
65
66 #else /* BITS_PER_LONG != 64 */
67
68 #include <linux/atomic.h>
69
70 /* Don't use typedef: don't want them to be mixed with atomic_t's. */
71 typedef struct {
72 atomic64_t a;
73 } local64_t;
74
75 #define LOCAL64_INIT(i) { ATOMIC_LONG_INIT(i) }
76
77 #define local64_read(l) atomic64_read(&(l)->a)
78 #define local64_set(l,i) atomic64_set((&(l)->a),(i))
79 #define local64_inc(l) atomic64_inc(&(l)->a)
80 #define local64_dec(l) atomic64_dec(&(l)->a)
81 #define local64_add(i,l) atomic64_add((i),(&(l)->a))
82 #define local64_sub(i,l) atomic64_sub((i),(&(l)->a))
83
84 #define local64_sub_and_test(i, l) atomic64_sub_and_test((i), (&(l)->a))
85 #define local64_dec_and_test(l) atomic64_dec_and_test(&(l)->a)
86 #define local64_inc_and_test(l) atomic64_inc_and_test(&(l)->a)
87 #define local64_add_negative(i, l) atomic64_add_negative((i), (&(l)->a))
88 #define local64_add_return(i, l) atomic64_add_return((i), (&(l)->a))
89 #define local64_sub_return(i, l) atomic64_sub_return((i), (&(l)->a))
90 #define local64_inc_return(l) atomic64_inc_return(&(l)->a)
91
92 #define local64_cmpxchg(l, o, n) atomic64_cmpxchg((&(l)->a), (o), (n))
93 #define local64_try_cmpxchg(l, po, n) atomic64_try_cmpxchg((&(l)->a), (po), (n))
94 #define local64_xchg(l, n) atomic64_xchg((&(l)->a), (n))
95 #define local64_add_unless(l, _a, u) atomic64_add_unless((&(l)->a), (_a), (u))
96 #define local64_inc_not_zero(l) atomic64_inc_not_zero(&(l)->a)
97
98 /* Non-atomic variants, ie. preemption disabled and won't be touched
99 * in interrupt, etc. Some archs can optimize this case well. */
100 #define __local64_inc(l) local64_set((l), local64_read(l) + 1)
101 #define __local64_dec(l) local64_set((l), local64_read(l) - 1)
102 #define __local64_add(i,l) local64_set((l), local64_read(l) + (i))
103 #define __local64_sub(i,l) local64_set((l), local64_read(l) - (i))
104
105 #endif /* BITS_PER_LONG != 64 */
106
107 #endif /* _ASM_GENERIC_LOCAL64_H */
108
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