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1da177e4 LT |
1 | #ifndef _ASM_GENERIC_LOCAL_H |
2 | #define _ASM_GENERIC_LOCAL_H | |
3 | ||
1da177e4 LT |
4 | #include <linux/percpu.h> |
5 | #include <linux/hardirq.h> | |
f5f5370d | 6 | #include <asm/atomic.h> |
1da177e4 LT |
7 | #include <asm/types.h> |
8 | ||
2cf8d82d AM |
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 | */ | |
1da177e4 | 18 | |
1da177e4 LT |
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 | { | |
f5f5370d | 24 | atomic_long_t a; |
1da177e4 LT |
25 | } local_t; |
26 | ||
f5f5370d | 27 | #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } |
1da177e4 | 28 | |
2cf8d82d | 29 | #define local_read(l) atomic_long_read(&(l)->a) |
f5f5370d KM |
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)) | |
1da177e4 | 35 | |
5e97b930 MD |
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_xchg(l, n) atomic_long_xchg((&(l)->a), (n)) | |
46 | #define local_add_unless(l, a, u) atomic_long_add_unless((&(l)->a), (a), (u)) | |
47 | #define local_inc_not_zero(l) atomic_long_inc_not_zero(&(l)->a) | |
48 | ||
1da177e4 LT |
49 | /* Non-atomic variants, ie. preemption disabled and won't be touched |
50 | * in interrupt, etc. Some archs can optimize this case well. */ | |
51 | #define __local_inc(l) local_set((l), local_read(l) + 1) | |
52 | #define __local_dec(l) local_set((l), local_read(l) - 1) | |
53 | #define __local_add(i,l) local_set((l), local_read(l) + (i)) | |
54 | #define __local_sub(i,l) local_set((l), local_read(l) - (i)) | |
55 | ||
1da177e4 LT |
56 | /* Use these for per-cpu local_t variables: on some archs they are |
57 | * much more efficient than these naive implementations. Note they take | |
58 | * a variable (eg. mystruct.foo), not an address. | |
59 | */ | |
5e97b930 MD |
60 | #define cpu_local_read(l) local_read(&__get_cpu_var(l)) |
61 | #define cpu_local_set(l, i) local_set(&__get_cpu_var(l), (i)) | |
62 | #define cpu_local_inc(l) local_inc(&__get_cpu_var(l)) | |
63 | #define cpu_local_dec(l) local_dec(&__get_cpu_var(l)) | |
64 | #define cpu_local_add(i, l) local_add((i), &__get_cpu_var(l)) | |
65 | #define cpu_local_sub(i, l) local_sub((i), &__get_cpu_var(l)) | |
1da177e4 LT |
66 | |
67 | /* Non-atomic increments, ie. preemption disabled and won't be touched | |
68 | * in interrupt, etc. Some archs can optimize this case well. | |
69 | */ | |
5e97b930 MD |
70 | #define __cpu_local_inc(l) __local_inc(&__get_cpu_var(l)) |
71 | #define __cpu_local_dec(l) __local_dec(&__get_cpu_var(l)) | |
72 | #define __cpu_local_add(i, l) __local_add((i), &__get_cpu_var(l)) | |
73 | #define __cpu_local_sub(i, l) __local_sub((i), &__get_cpu_var(l)) | |
1da177e4 LT |
74 | |
75 | #endif /* _ASM_GENERIC_LOCAL_H */ |