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#ifndef __LINUX_PCOUNTER_H
#define __LINUX_PCOUNTER_H
struct pcounter {
#ifdef CONFIG_SMP
void (*add)(struct pcounter *self, int inc);
int (*getval)(const struct pcounter *self);
int *per_cpu_values;
#else
int val;
#endif
};
/*
* Special macros to let pcounters use a fast version of {getvalue|add}
* using a static percpu variable per pcounter instead of an allocated one,
* saving one dereference.
* This might be changed if/when dynamic percpu vars become fast.
*/
#ifdef CONFIG_SMP
#include <linux/cpumask.h>
#include <linux/percpu.h>
#define DEFINE_PCOUNTER(NAME) \
static DEFINE_PER_CPU(int, NAME##_pcounter_values); \
static void NAME##_pcounter_add(struct pcounter *self, int inc) \
{ \
__get_cpu_var(NAME##_pcounter_values) += inc; \
} \
\
static int NAME##_pcounter_getval(const struct pcounter *self) \
{ \
int res = 0, cpu; \
\
for_each_possible_cpu(cpu) \
res += per_cpu(NAME##_pcounter_values, cpu); \
return res; \
}
#define PCOUNTER_MEMBER_INITIALIZER(NAME, MEMBER) \
MEMBER = { \
.add = NAME##_pcounter_add, \
.getval = NAME##_pcounter_getval, \
}
extern void pcounter_def_add(struct pcounter *self, int inc);
extern int pcounter_def_getval(const struct pcounter *self);
static inline int pcounter_alloc(struct pcounter *self)
{
int rc = 0;
if (self->add == NULL) {
self->per_cpu_values = alloc_percpu(int);
if (self->per_cpu_values != NULL) {
self->add = pcounter_def_add;
self->getval = pcounter_def_getval;
} else
rc = 1;
}
return rc;
}
static inline void pcounter_free(struct pcounter *self)
{
if (self->per_cpu_values != NULL) {
free_percpu(self->per_cpu_values);
self->per_cpu_values = NULL;
self->getval = NULL;
self->add = NULL;
}
}
static inline void pcounter_add(struct pcounter *self, int inc)
{
self->add(self, inc);
}
static inline int pcounter_getval(const struct pcounter *self)
{
return self->getval(self);
}
#else /* CONFIG_SMP */
static inline void pcounter_add(struct pcounter *self, int inc)
{
self->val += inc;
}
static inline int pcounter_getval(const struct pcounter *self)
{
return self->val;
}
#define DEFINE_PCOUNTER(NAME)
#define PCOUNTER_MEMBER_INITIALIZER(NAME, MEMBER)
#define pcounter_alloc(self) 0
#define pcounter_free(self)
#endif /* CONFIG_SMP */
#endif /* __LINUX_PCOUNTER_H */
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