X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=include%2Fasm-generic%2Flocal.h;h=dbd6150763e90a0d1fb52c559886639b641a3ff1;hb=9f722c0978b04acba209f8ca1896ad05814bc3a3;hp=16fc00360f7582eef14a9934c9d6fe7f3abf7f7c;hpb=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2;p=safe%2Fjmp%2Flinux-2.6 diff --git a/include/asm-generic/local.h b/include/asm-generic/local.h index 16fc003..dbd6150 100644 --- a/include/asm-generic/local.h +++ b/include/asm-generic/local.h @@ -1,31 +1,49 @@ #ifndef _ASM_GENERIC_LOCAL_H #define _ASM_GENERIC_LOCAL_H -#include #include -#include +#include #include -/* An unsigned long type for operations which are atomic for a single - * CPU. Usually used in combination with per-cpu variables. */ +/* + * A signed long type for operations which are atomic for a single CPU. + * Usually used in combination with per-cpu variables. + * + * This is the default implementation, which uses atomic_long_t. Which is + * rather pointless. The whole point behind local_t is that some processors + * can perform atomic adds and subtracts in a manner which is atomic wrt IRQs + * running on this CPU. local_t allows exploitation of such capabilities. + */ -#if BITS_PER_LONG == 32 /* Implement in terms of atomics. */ /* Don't use typedef: don't want them to be mixed with atomic_t's. */ typedef struct { - atomic_t a; + atomic_long_t a; } local_t; -#define LOCAL_INIT(i) { ATOMIC_INIT(i) } +#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } + +#define local_read(l) atomic_long_read(&(l)->a) +#define local_set(l,i) atomic_long_set((&(l)->a),(i)) +#define local_inc(l) atomic_long_inc(&(l)->a) +#define local_dec(l) atomic_long_dec(&(l)->a) +#define local_add(i,l) atomic_long_add((i),(&(l)->a)) +#define local_sub(i,l) atomic_long_sub((i),(&(l)->a)) -#define local_read(l) ((unsigned long)atomic_read(&(l)->a)) -#define local_set(l,i) atomic_set((&(l)->a),(i)) -#define local_inc(l) atomic_inc(&(l)->a) -#define local_dec(l) atomic_dec(&(l)->a) -#define local_add(i,l) atomic_add((i),(&(l)->a)) -#define local_sub(i,l) atomic_sub((i),(&(l)->a)) +#define local_sub_and_test(i, l) atomic_long_sub_and_test((i), (&(l)->a)) +#define local_dec_and_test(l) atomic_long_dec_and_test(&(l)->a) +#define local_inc_and_test(l) atomic_long_inc_and_test(&(l)->a) +#define local_add_negative(i, l) atomic_long_add_negative((i), (&(l)->a)) +#define local_add_return(i, l) atomic_long_add_return((i), (&(l)->a)) +#define local_sub_return(i, l) atomic_long_sub_return((i), (&(l)->a)) +#define local_inc_return(l) atomic_long_inc_return(&(l)->a) + +#define local_cmpxchg(l, o, n) atomic_long_cmpxchg((&(l)->a), (o), (n)) +#define local_xchg(l, n) atomic_long_xchg((&(l)->a), (n)) +#define local_add_unless(l, a, u) atomic_long_add_unless((&(l)->a), (a), (u)) +#define local_inc_not_zero(l) atomic_long_inc_not_zero(&(l)->a) /* Non-atomic variants, ie. preemption disabled and won't be touched * in interrupt, etc. Some archs can optimize this case well. */ @@ -34,85 +52,23 @@ typedef struct #define __local_add(i,l) local_set((l), local_read(l) + (i)) #define __local_sub(i,l) local_set((l), local_read(l) - (i)) -#else /* ... can't use atomics. */ -/* Implement in terms of three variables. - Another option would be to use local_irq_save/restore. */ - -typedef struct -{ - /* 0 = in hardirq, 1 = in softirq, 2 = usermode. */ - unsigned long v[3]; -} local_t; - -#define _LOCAL_VAR(l) ((l)->v[!in_interrupt() + !in_irq()]) - -#define LOCAL_INIT(i) { { (i), 0, 0 } } - -static inline unsigned long local_read(local_t *l) -{ - return l->v[0] + l->v[1] + l->v[2]; -} - -static inline void local_set(local_t *l, unsigned long v) -{ - l->v[0] = v; - l->v[1] = l->v[2] = 0; -} - -static inline void local_inc(local_t *l) -{ - preempt_disable(); - _LOCAL_VAR(l)++; - preempt_enable(); -} - -static inline void local_dec(local_t *l) -{ - preempt_disable(); - _LOCAL_VAR(l)--; - preempt_enable(); -} - -static inline void local_add(unsigned long v, local_t *l) -{ - preempt_disable(); - _LOCAL_VAR(l) += v; - preempt_enable(); -} - -static inline void local_sub(unsigned long v, local_t *l) -{ - preempt_disable(); - _LOCAL_VAR(l) -= v; - preempt_enable(); -} - -/* Non-atomic variants, ie. preemption disabled and won't be touched - * in interrupt, etc. Some archs can optimize this case well. */ -#define __local_inc(l) ((l)->v[0]++) -#define __local_dec(l) ((l)->v[0]--) -#define __local_add(i,l) ((l)->v[0] += (i)) -#define __local_sub(i,l) ((l)->v[0] -= (i)) - -#endif /* Non-atomic implementation */ - /* Use these for per-cpu local_t variables: on some archs they are * much more efficient than these naive implementations. Note they take * a variable (eg. mystruct.foo), not an address. */ -#define cpu_local_read(v) local_read(&__get_cpu_var(v)) -#define cpu_local_set(v, i) local_set(&__get_cpu_var(v), (i)) -#define cpu_local_inc(v) local_inc(&__get_cpu_var(v)) -#define cpu_local_dec(v) local_dec(&__get_cpu_var(v)) -#define cpu_local_add(i, v) local_add((i), &__get_cpu_var(v)) -#define cpu_local_sub(i, v) local_sub((i), &__get_cpu_var(v)) +#define cpu_local_read(l) local_read(&__get_cpu_var(l)) +#define cpu_local_set(l, i) local_set(&__get_cpu_var(l), (i)) +#define cpu_local_inc(l) local_inc(&__get_cpu_var(l)) +#define cpu_local_dec(l) local_dec(&__get_cpu_var(l)) +#define cpu_local_add(i, l) local_add((i), &__get_cpu_var(l)) +#define cpu_local_sub(i, l) local_sub((i), &__get_cpu_var(l)) /* Non-atomic increments, ie. preemption disabled and won't be touched * in interrupt, etc. Some archs can optimize this case well. */ -#define __cpu_local_inc(v) __local_inc(&__get_cpu_var(v)) -#define __cpu_local_dec(v) __local_dec(&__get_cpu_var(v)) -#define __cpu_local_add(i, v) __local_add((i), &__get_cpu_var(v)) -#define __cpu_local_sub(i, v) __local_sub((i), &__get_cpu_var(v)) +#define __cpu_local_inc(l) __local_inc(&__get_cpu_var(l)) +#define __cpu_local_dec(l) __local_dec(&__get_cpu_var(l)) +#define __cpu_local_add(i, l) __local_add((i), &__get_cpu_var(l)) +#define __cpu_local_sub(i, l) __local_sub((i), &__get_cpu_var(l)) #endif /* _ASM_GENERIC_LOCAL_H */