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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | #ifndef _ASM_GENERIC_LOCAL_H |
| 2 | #define _ASM_GENERIC_LOCAL_H |
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| 3 | |||
| 4 | #include <linux/config.h> |
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| 5 | #include <linux/percpu.h> |
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| 6 | #include <asm/types.h> |
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| 7 | #include <asm/hardirq.h> |
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| 8 | |||
| 9 | /* An unsigned long type for operations which are atomic for a single |
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| 10 | * CPU. Usually used in combination with per-cpu variables. */ |
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| 11 | |||
| 12 | #if BITS_PER_LONG == 32 && !defined(CONFIG_SPARC32) |
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| 13 | /* Implement in terms of atomics. */ |
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| 14 | |||
| 15 | /* Don't use typedef: don't want them to be mixed with atomic_t's. */ |
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| 16 | typedef struct |
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| 17 | { |
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| 18 | atomic_t a; |
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| 19 | } local_t; |
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| 20 | |||
| 21 | #define LOCAL_INIT(i) { ATOMIC_INIT(i) } |
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| 22 | |||
| 23 | #define local_read(l) ((unsigned long)atomic_read(&(l)->a)) |
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| 24 | #define local_set(l,i) atomic_set((&(l)->a),(i)) |
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| 25 | #define local_inc(l) atomic_inc(&(l)->a) |
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| 26 | #define local_dec(l) atomic_dec(&(l)->a) |
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| 27 | #define local_add(i,l) atomic_add((i),(&(l)->a)) |
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| 28 | #define local_sub(i,l) atomic_sub((i),(&(l)->a)) |
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| 29 | |||
| 30 | /* Non-atomic variants, ie. preemption disabled and won't be touched |
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| 31 | * in interrupt, etc. Some archs can optimize this case well. */ |
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| 32 | #define __local_inc(l) local_set((l), local_read(l) + 1) |
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| 33 | #define __local_dec(l) local_set((l), local_read(l) - 1) |
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| 34 | #define __local_add(i,l) local_set((l), local_read(l) + (i)) |
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| 35 | #define __local_sub(i,l) local_set((l), local_read(l) - (i)) |
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| 36 | |||
| 37 | #else /* ... can't use atomics. */ |
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| 38 | /* Implement in terms of three variables. |
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| 39 | Another option would be to use local_irq_save/restore. */ |
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| 40 | |||
| 41 | typedef struct |
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| 42 | { |
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| 43 | /* 0 = in hardirq, 1 = in softirq, 2 = usermode. */ |
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| 44 | unsigned long v[3]; |
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| 45 | } local_t; |
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| 46 | |||
| 47 | #define _LOCAL_VAR(l) ((l)->v[!in_interrupt() + !in_irq()]) |
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| 48 | |||
| 49 | #define LOCAL_INIT(i) { { (i), 0, 0 } } |
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| 50 | |||
| 51 | static inline unsigned long local_read(local_t *l) |
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| 52 | { |
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| 53 | return l->v[0] + l->v[1] + l->v[2]; |
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| 54 | } |
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| 55 | |||
| 56 | static inline void local_set(local_t *l, unsigned long v) |
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| 57 | { |
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| 58 | l->v[0] = v; |
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| 59 | l->v[1] = l->v[2] = 0; |
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| 60 | } |
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| 61 | |||
| 62 | static inline void local_inc(local_t *l) |
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| 63 | { |
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| 64 | preempt_disable(); |
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| 65 | _LOCAL_VAR(l)++; |
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| 66 | preempt_enable(); |
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| 67 | } |
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| 68 | |||
| 69 | static inline void local_dec(local_t *l) |
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| 70 | { |
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| 71 | preempt_disable(); |
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| 72 | _LOCAL_VAR(l)--; |
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| 73 | preempt_enable(); |
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| 74 | } |
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| 75 | |||
| 76 | static inline void local_add(unsigned long v, local_t *l) |
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| 77 | { |
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| 78 | preempt_disable(); |
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| 79 | _LOCAL_VAR(l) += v; |
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| 80 | preempt_enable(); |
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| 81 | } |
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| 82 | |||
| 83 | static inline void local_sub(unsigned long v, local_t *l) |
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| 84 | { |
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| 85 | preempt_disable(); |
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| 86 | _LOCAL_VAR(l) -= v; |
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| 87 | preempt_enable(); |
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| 88 | } |
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| 89 | |||
| 90 | /* Non-atomic variants, ie. preemption disabled and won't be touched |
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| 91 | * in interrupt, etc. Some archs can optimize this case well. */ |
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| 92 | #define __local_inc(l) ((l)->v[0]++) |
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| 93 | #define __local_dec(l) ((l)->v[0]--) |
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| 94 | #define __local_add(i,l) ((l)->v[0] += (i)) |
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| 95 | #define __local_sub(i,l) ((l)->v[0] -= (i)) |
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| 96 | |||
| 97 | #endif /* Non-atomic implementation */ |
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| 98 | |||
| 99 | /* Use these for per-cpu local_t variables: on some archs they are |
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| 100 | * much more efficient than these naive implementations. Note they take |
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| 101 | * a variable (eg. mystruct.foo), not an address. |
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| 102 | */ |
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| 103 | #define cpu_local_read(v) local_read(&__get_cpu_var(v)) |
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| 104 | #define cpu_local_set(v, i) local_set(&__get_cpu_var(v), (i)) |
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| 105 | #define cpu_local_inc(v) local_inc(&__get_cpu_var(v)) |
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| 106 | #define cpu_local_dec(v) local_dec(&__get_cpu_var(v)) |
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| 107 | #define cpu_local_add(i, v) local_add((i), &__get_cpu_var(v)) |
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| 108 | #define cpu_local_sub(i, v) local_sub((i), &__get_cpu_var(v)) |
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| 109 | |||
| 110 | /* Non-atomic increments, ie. preemption disabled and won't be touched |
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| 111 | * in interrupt, etc. Some archs can optimize this case well. |
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| 112 | */ |
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| 113 | #define __cpu_local_inc(v) __local_inc(&__get_cpu_var(v)) |
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| 114 | #define __cpu_local_dec(v) __local_dec(&__get_cpu_var(v)) |
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| 115 | #define __cpu_local_add(i, v) __local_add((i), &__get_cpu_var(v)) |
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| 116 | #define __cpu_local_sub(i, v) __local_sub((i), &__get_cpu_var(v)) |
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| 117 | |||
| 118 | #endif /* _ASM_GENERIC_LOCAL_H */ |