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
24typedef 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
45static inline s64 local64_cmpxchg(local64_t *l, s64 old, s64 new)
46{
47 return local_cmpxchg(l: &l->a, old, new);
48}
49
50static inline bool local64_try_cmpxchg(local64_t *l, s64 *old, s64 new)
51{
52 return local_try_cmpxchg(l: &l->a, old: (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. */
71typedef 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