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# ifndef _ASM_GENERIC_LOCAL_H
# define _ASM_GENERIC_LOCAL_H
# include <linux/config.h>
# include <linux/percpu.h>
# include <linux/hardirq.h>
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# include <asm/atomic.h>
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# include <asm/types.h>
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/*
* 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 .
*/
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/* Implement in terms of atomics. */
/* Don't use typedef: don't want them to be mixed with atomic_t's. */
typedef struct
{
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atomic_long_t a ;
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} local_t ;
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# define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) }
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# define local_read(l) atomic_long_read(&(l)->a)
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# 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))
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/* 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) local_set((l), local_read(l) + 1)
# define __local_dec(l) local_set((l), local_read(l) - 1)
# define __local_add(i,l) local_set((l), local_read(l) + (i))
# define __local_sub(i,l) local_set((l), local_read(l) - (i))
/* 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))
/* 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))
# endif /* _ASM_GENERIC_LOCAL_H */