Warning: This file is not a C or C++ file. It does not have highlighting.
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
---|---|
2 | #ifndef _ASM_GENERIC_LOCAL_H |
3 | #define _ASM_GENERIC_LOCAL_H |
4 | |
5 | #include <linux/percpu.h> |
6 | #include <linux/atomic.h> |
7 | #include <asm/types.h> |
8 | |
9 | /* |
10 | * A signed long type for operations which are atomic for a single CPU. |
11 | * Usually used in combination with per-cpu variables. |
12 | * |
13 | * This is the default implementation, which uses atomic_long_t. Which is |
14 | * rather pointless. The whole point behind local_t is that some processors |
15 | * can perform atomic adds and subtracts in a manner which is atomic wrt IRQs |
16 | * running on this CPU. local_t allows exploitation of such capabilities. |
17 | */ |
18 | |
19 | /* Implement in terms of atomics. */ |
20 | |
21 | /* Don't use typedef: don't want them to be mixed with atomic_t's. */ |
22 | typedef struct |
23 | { |
24 | atomic_long_t a; |
25 | } local_t; |
26 | |
27 | #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } |
28 | |
29 | #define local_read(l) atomic_long_read(&(l)->a) |
30 | #define local_set(l,i) atomic_long_set((&(l)->a),(i)) |
31 | #define local_inc(l) atomic_long_inc(&(l)->a) |
32 | #define local_dec(l) atomic_long_dec(&(l)->a) |
33 | #define local_add(i,l) atomic_long_add((i),(&(l)->a)) |
34 | #define local_sub(i,l) atomic_long_sub((i),(&(l)->a)) |
35 | |
36 | #define local_sub_and_test(i, l) atomic_long_sub_and_test((i), (&(l)->a)) |
37 | #define local_dec_and_test(l) atomic_long_dec_and_test(&(l)->a) |
38 | #define local_inc_and_test(l) atomic_long_inc_and_test(&(l)->a) |
39 | #define local_add_negative(i, l) atomic_long_add_negative((i), (&(l)->a)) |
40 | #define local_add_return(i, l) atomic_long_add_return((i), (&(l)->a)) |
41 | #define local_sub_return(i, l) atomic_long_sub_return((i), (&(l)->a)) |
42 | #define local_inc_return(l) atomic_long_inc_return(&(l)->a) |
43 | |
44 | #define local_cmpxchg(l, o, n) atomic_long_cmpxchg((&(l)->a), (o), (n)) |
45 | #define local_try_cmpxchg(l, po, n) atomic_long_try_cmpxchg((&(l)->a), (po), (n)) |
46 | #define local_xchg(l, n) atomic_long_xchg((&(l)->a), (n)) |
47 | #define local_add_unless(l, _a, u) atomic_long_add_unless((&(l)->a), (_a), (u)) |
48 | #define local_inc_not_zero(l) atomic_long_inc_not_zero(&(l)->a) |
49 | |
50 | /* Non-atomic variants, ie. preemption disabled and won't be touched |
51 | * in interrupt, etc. Some archs can optimize this case well. */ |
52 | #define __local_inc(l) local_set((l), local_read(l) + 1) |
53 | #define __local_dec(l) local_set((l), local_read(l) - 1) |
54 | #define __local_add(i,l) local_set((l), local_read(l) + (i)) |
55 | #define __local_sub(i,l) local_set((l), local_read(l) - (i)) |
56 | |
57 | #endif /* _ASM_GENERIC_LOCAL_H */ |
58 |
Warning: This file is not a C or C++ file. It does not have highlighting.