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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>
#include <asm/types.h>
/* An unsigned long type for operations which are atomic for a single
* CPU. Usually used in combination with per-cpu variables. */
#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;
} local_t;
#define LOCAL_INIT(i) { ATOMIC_INIT(i) }
#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))
/* 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))
#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))
/* 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 */
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