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#ifndef __LINUX_PERCPU_H
#define __LINUX_PERCPU_H
#include <linux/spinlock.h> /* For preempt_disable() */
#include <linux/slab.h> /* For kmalloc() */
#include <linux/smp.h>
#include <linux/string.h> /* For memset() */
#include <asm/percpu.h>
/* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */
#ifndef PERCPU_ENOUGH_ROOM
#define PERCPU_ENOUGH_ROOM 32768
#endif
/*
* Must be an lvalue. Since @var must be a simple identifier,
* we force a syntax error here if it isn't.
*/
#define get_cpu_var(var) (*({ \
extern int simple_indentifier_##var(void); \
preempt_disable(); \
&__get_cpu_var(var); }))
#define put_cpu_var(var) preempt_enable()
#ifdef CONFIG_SMP
struct percpu_data {
void *ptrs[NR_CPUS];
};
/*
* Use this to get to a cpu's version of the per-cpu object allocated using
* alloc_percpu. Non-atomic access to the current CPU's version should
* probably be combined with get_cpu()/put_cpu().
*/
#define per_cpu_ptr(ptr, cpu) \
({ \
struct percpu_data *__p = (struct percpu_data *)~(unsigned long)(ptr); \
(__typeof__(ptr))__p->ptrs[(cpu)]; \
})
extern void *__alloc_percpu(size_t size);
extern void free_percpu(const void *);
#else /* CONFIG_SMP */
#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
static inline void *__alloc_percpu(size_t size)
{
void *ret = kmalloc(size, GFP_KERNEL);
if (ret)
memset(ret, 0, size);
return ret;
}
static inline void free_percpu(const void *ptr)
{
kfree(ptr);
}
#endif /* CONFIG_SMP */
/* Simple wrapper for the common case: zeros memory. */
#define alloc_percpu(type) ((type *)(__alloc_percpu(sizeof(type))))
#endif /* __LINUX_PERCPU_H */
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