Rev 422 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 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 <asm/types.h> |
||
| 7 | #include <asm/hardirq.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 && !defined(CONFIG_SPARC32) |
||
| 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 */ |