Linux kernel mirror (for testing)
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linux
1#ifndef __LINUX_PERCPU_H
2#define __LINUX_PERCPU_H
3
4#include <linux/spinlock.h> /* For preempt_disable() */
5#include <linux/slab.h> /* For kmalloc() */
6#include <linux/smp.h>
7#include <linux/string.h> /* For memset() */
8#include <linux/cpumask.h>
9
10#include <asm/percpu.h>
11
12/* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */
13#ifndef PERCPU_ENOUGH_ROOM
14#define PERCPU_ENOUGH_ROOM 32768
15#endif
16
17/*
18 * Must be an lvalue. Since @var must be a simple identifier,
19 * we force a syntax error here if it isn't.
20 */
21#define get_cpu_var(var) (*({ \
22 extern int simple_identifier_##var(void); \
23 preempt_disable(); \
24 &__get_cpu_var(var); }))
25#define put_cpu_var(var) preempt_enable()
26
27#ifdef CONFIG_SMP
28
29struct percpu_data {
30 void *ptrs[NR_CPUS];
31};
32
33#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
34/*
35 * Use this to get to a cpu's version of the per-cpu object dynamically
36 * allocated. Non-atomic access to the current CPU's version should
37 * probably be combined with get_cpu()/put_cpu().
38 */
39#define percpu_ptr(ptr, cpu) \
40({ \
41 struct percpu_data *__p = __percpu_disguise(ptr); \
42 (__typeof__(ptr))__p->ptrs[(cpu)]; \
43})
44
45extern void *percpu_populate(void *__pdata, size_t size, gfp_t gfp, int cpu);
46extern void percpu_depopulate(void *__pdata, int cpu);
47extern int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
48 cpumask_t *mask);
49extern void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask);
50extern void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask);
51extern void percpu_free(void *__pdata);
52
53#else /* CONFIG_SMP */
54
55#define percpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
56
57static inline void percpu_depopulate(void *__pdata, int cpu)
58{
59}
60
61static inline void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask)
62{
63}
64
65static inline void *percpu_populate(void *__pdata, size_t size, gfp_t gfp,
66 int cpu)
67{
68 return percpu_ptr(__pdata, cpu);
69}
70
71static inline int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
72 cpumask_t *mask)
73{
74 return 0;
75}
76
77static __always_inline void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
78{
79 return kzalloc(size, gfp);
80}
81
82static inline void percpu_free(void *__pdata)
83{
84 kfree(__pdata);
85}
86
87#endif /* CONFIG_SMP */
88
89#define percpu_populate_mask(__pdata, size, gfp, mask) \
90 __percpu_populate_mask((__pdata), (size), (gfp), &(mask))
91#define percpu_depopulate_mask(__pdata, mask) \
92 __percpu_depopulate_mask((__pdata), &(mask))
93#define percpu_alloc_mask(size, gfp, mask) \
94 __percpu_alloc_mask((size), (gfp), &(mask))
95
96#define percpu_alloc(size, gfp) percpu_alloc_mask((size), (gfp), cpu_online_map)
97
98/* (legacy) interface for use without CPU hotplug handling */
99
100#define __alloc_percpu(size) percpu_alloc_mask((size), GFP_KERNEL, \
101 cpu_possible_map)
102#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type))
103#define free_percpu(ptr) percpu_free((ptr))
104#define per_cpu_ptr(ptr, cpu) percpu_ptr((ptr), (cpu))
105
106#endif /* __LINUX_PERCPU_H */