Linux kernel mirror (for testing)
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linux
1#ifndef __LINUX_PERCPU_H
2#define __LINUX_PERCPU_H
3
4#include <linux/preempt.h>
5#include <linux/slab.h> /* For kmalloc() */
6#include <linux/smp.h>
7#include <linux/cpumask.h>
8
9#include <asm/percpu.h>
10
11#ifdef CONFIG_SMP
12#define DEFINE_PER_CPU(type, name) \
13 __attribute__((__section__(".data.percpu"))) \
14 PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
15
16#ifdef MODULE
17#define SHARED_ALIGNED_SECTION ".data.percpu"
18#else
19#define SHARED_ALIGNED_SECTION ".data.percpu.shared_aligned"
20#endif
21
22#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \
23 __attribute__((__section__(SHARED_ALIGNED_SECTION))) \
24 PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name \
25 ____cacheline_aligned_in_smp
26#else
27#define DEFINE_PER_CPU(type, name) \
28 PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
29
30#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \
31 DEFINE_PER_CPU(type, name)
32#endif
33
34#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
35#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
36
37/* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */
38#ifndef PERCPU_ENOUGH_ROOM
39#ifdef CONFIG_MODULES
40#define PERCPU_MODULE_RESERVE 8192
41#else
42#define PERCPU_MODULE_RESERVE 0
43#endif
44
45#define PERCPU_ENOUGH_ROOM \
46 (__per_cpu_end - __per_cpu_start + PERCPU_MODULE_RESERVE)
47#endif /* PERCPU_ENOUGH_ROOM */
48
49/*
50 * Must be an lvalue. Since @var must be a simple identifier,
51 * we force a syntax error here if it isn't.
52 */
53#define get_cpu_var(var) (*({ \
54 extern int simple_identifier_##var(void); \
55 preempt_disable(); \
56 &__get_cpu_var(var); }))
57#define put_cpu_var(var) preempt_enable()
58
59#ifdef CONFIG_SMP
60
61struct percpu_data {
62 void *ptrs[1];
63};
64
65#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
66/*
67 * Use this to get to a cpu's version of the per-cpu object dynamically
68 * allocated. Non-atomic access to the current CPU's version should
69 * probably be combined with get_cpu()/put_cpu().
70 */
71#define percpu_ptr(ptr, cpu) \
72({ \
73 struct percpu_data *__p = __percpu_disguise(ptr); \
74 (__typeof__(ptr))__p->ptrs[(cpu)]; \
75})
76
77extern void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask);
78extern void percpu_free(void *__pdata);
79
80#else /* CONFIG_SMP */
81
82#define percpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
83
84static __always_inline void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
85{
86 return kzalloc(size, gfp);
87}
88
89static inline void percpu_free(void *__pdata)
90{
91 kfree(__pdata);
92}
93
94#endif /* CONFIG_SMP */
95
96#define percpu_alloc_mask(size, gfp, mask) \
97 __percpu_alloc_mask((size), (gfp), &(mask))
98
99#define percpu_alloc(size, gfp) percpu_alloc_mask((size), (gfp), cpu_online_map)
100
101/* (legacy) interface for use without CPU hotplug handling */
102
103#define __alloc_percpu(size) percpu_alloc_mask((size), GFP_KERNEL, \
104 cpu_possible_map)
105#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type))
106#define free_percpu(ptr) percpu_free((ptr))
107#define per_cpu_ptr(ptr, cpu) percpu_ptr((ptr), (cpu))
108
109#endif /* __LINUX_PERCPU_H */