diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-generic/local.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-generic/local.h')
-rw-r--r-- | include/asm-generic/local.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/include/asm-generic/local.h b/include/asm-generic/local.h new file mode 100644 index 000000000000..16fc00360f75 --- /dev/null +++ b/include/asm-generic/local.h | |||
@@ -0,0 +1,118 @@ | |||
1 | #ifndef _ASM_GENERIC_LOCAL_H | ||
2 | #define _ASM_GENERIC_LOCAL_H | ||
3 | |||
4 | #include <linux/config.h> | ||
5 | #include <linux/percpu.h> | ||
6 | #include <linux/hardirq.h> | ||
7 | #include <asm/types.h> | ||
8 | |||
9 | /* An unsigned long type for operations which are atomic for a single | ||
10 | * CPU. Usually used in combination with per-cpu variables. */ | ||
11 | |||
12 | #if BITS_PER_LONG == 32 | ||
13 | /* Implement in terms of atomics. */ | ||
14 | |||
15 | /* Don't use typedef: don't want them to be mixed with atomic_t's. */ | ||
16 | typedef struct | ||
17 | { | ||
18 | atomic_t a; | ||
19 | } local_t; | ||
20 | |||
21 | #define LOCAL_INIT(i) { ATOMIC_INIT(i) } | ||
22 | |||
23 | #define local_read(l) ((unsigned long)atomic_read(&(l)->a)) | ||
24 | #define local_set(l,i) atomic_set((&(l)->a),(i)) | ||
25 | #define local_inc(l) atomic_inc(&(l)->a) | ||
26 | #define local_dec(l) atomic_dec(&(l)->a) | ||
27 | #define local_add(i,l) atomic_add((i),(&(l)->a)) | ||
28 | #define local_sub(i,l) atomic_sub((i),(&(l)->a)) | ||
29 | |||
30 | /* Non-atomic variants, ie. preemption disabled and won't be touched | ||
31 | * in interrupt, etc. Some archs can optimize this case well. */ | ||
32 | #define __local_inc(l) local_set((l), local_read(l) + 1) | ||
33 | #define __local_dec(l) local_set((l), local_read(l) - 1) | ||
34 | #define __local_add(i,l) local_set((l), local_read(l) + (i)) | ||
35 | #define __local_sub(i,l) local_set((l), local_read(l) - (i)) | ||
36 | |||
37 | #else /* ... can't use atomics. */ | ||
38 | /* Implement in terms of three variables. | ||
39 | Another option would be to use local_irq_save/restore. */ | ||
40 | |||
41 | typedef struct | ||
42 | { | ||
43 | /* 0 = in hardirq, 1 = in softirq, 2 = usermode. */ | ||
44 | unsigned long v[3]; | ||
45 | } local_t; | ||
46 | |||
47 | #define _LOCAL_VAR(l) ((l)->v[!in_interrupt() + !in_irq()]) | ||
48 | |||
49 | #define LOCAL_INIT(i) { { (i), 0, 0 } } | ||
50 | |||
51 | static inline unsigned long local_read(local_t *l) | ||
52 | { | ||
53 | return l->v[0] + l->v[1] + l->v[2]; | ||
54 | } | ||
55 | |||
56 | static inline void local_set(local_t *l, unsigned long v) | ||
57 | { | ||
58 | l->v[0] = v; | ||
59 | l->v[1] = l->v[2] = 0; | ||
60 | } | ||
61 | |||
62 | static inline void local_inc(local_t *l) | ||
63 | { | ||
64 | preempt_disable(); | ||
65 | _LOCAL_VAR(l)++; | ||
66 | preempt_enable(); | ||
67 | } | ||
68 | |||
69 | static inline void local_dec(local_t *l) | ||
70 | { | ||
71 | preempt_disable(); | ||
72 | _LOCAL_VAR(l)--; | ||
73 | preempt_enable(); | ||
74 | } | ||
75 | |||
76 | static inline void local_add(unsigned long v, local_t *l) | ||
77 | { | ||
78 | preempt_disable(); | ||
79 | _LOCAL_VAR(l) += v; | ||
80 | preempt_enable(); | ||
81 | } | ||
82 | |||
83 | static inline void local_sub(unsigned long v, local_t *l) | ||
84 | { | ||
85 | preempt_disable(); | ||
86 | _LOCAL_VAR(l) -= v; | ||
87 | preempt_enable(); | ||
88 | } | ||
89 | |||
90 | /* Non-atomic variants, ie. preemption disabled and won't be touched | ||
91 | * in interrupt, etc. Some archs can optimize this case well. */ | ||
92 | #define __local_inc(l) ((l)->v[0]++) | ||
93 | #define __local_dec(l) ((l)->v[0]--) | ||
94 | #define __local_add(i,l) ((l)->v[0] += (i)) | ||
95 | #define __local_sub(i,l) ((l)->v[0] -= (i)) | ||
96 | |||
97 | #endif /* Non-atomic implementation */ | ||
98 | |||
99 | /* Use these for per-cpu local_t variables: on some archs they are | ||
100 | * much more efficient than these naive implementations. Note they take | ||
101 | * a variable (eg. mystruct.foo), not an address. | ||
102 | */ | ||
103 | #define cpu_local_read(v) local_read(&__get_cpu_var(v)) | ||
104 | #define cpu_local_set(v, i) local_set(&__get_cpu_var(v), (i)) | ||
105 | #define cpu_local_inc(v) local_inc(&__get_cpu_var(v)) | ||
106 | #define cpu_local_dec(v) local_dec(&__get_cpu_var(v)) | ||
107 | #define cpu_local_add(i, v) local_add((i), &__get_cpu_var(v)) | ||
108 | #define cpu_local_sub(i, v) local_sub((i), &__get_cpu_var(v)) | ||
109 | |||
110 | /* Non-atomic increments, ie. preemption disabled and won't be touched | ||
111 | * in interrupt, etc. Some archs can optimize this case well. | ||
112 | */ | ||
113 | #define __cpu_local_inc(v) __local_inc(&__get_cpu_var(v)) | ||
114 | #define __cpu_local_dec(v) __local_dec(&__get_cpu_var(v)) | ||
115 | #define __cpu_local_add(i, v) __local_add((i), &__get_cpu_var(v)) | ||
116 | #define __cpu_local_sub(i, v) __local_sub((i), &__get_cpu_var(v)) | ||
117 | |||
118 | #endif /* _ASM_GENERIC_LOCAL_H */ | ||