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
27#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \
28 __attribute__((__section__(".data.percpu.page_aligned"))) \
29 PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
30#else
31#define DEFINE_PER_CPU(type, name) \
32 PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
33
34#define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \
35 DEFINE_PER_CPU(type, name)
36
37#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \
38 DEFINE_PER_CPU(type, name)
39#endif
40
41#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
42#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
43
44/* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */
45#ifndef PERCPU_ENOUGH_ROOM
46#ifdef CONFIG_MODULES
47#define PERCPU_MODULE_RESERVE 8192
48#else
49#define PERCPU_MODULE_RESERVE 0
50#endif
51
52#define PERCPU_ENOUGH_ROOM \
53 (__per_cpu_end - __per_cpu_start + PERCPU_MODULE_RESERVE)
54#endif /* PERCPU_ENOUGH_ROOM */
55
56/*
57 * Must be an lvalue. Since @var must be a simple identifier,
58 * we force a syntax error here if it isn't.
59 */
60#define get_cpu_var(var) (*({ \
61 extern int simple_identifier_##var(void); \
62 preempt_disable(); \
63 &__get_cpu_var(var); }))
64#define put_cpu_var(var) preempt_enable()
65
66#ifdef CONFIG_SMP
67
68struct percpu_data {
69 void *ptrs[1];
70};
71
72#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
73/*
74 * Use this to get to a cpu's version of the per-cpu object dynamically
75 * allocated. Non-atomic access to the current CPU's version should
76 * probably be combined with get_cpu()/put_cpu().
77 */
78#define percpu_ptr(ptr, cpu) \
79({ \
80 struct percpu_data *__p = __percpu_disguise(ptr); \
81 (__typeof__(ptr))__p->ptrs[(cpu)]; \
82})
83
84extern void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask);
85extern void percpu_free(void *__pdata);
86
87#else /* CONFIG_SMP */
88
89#define percpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
90
91static __always_inline void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
92{
93 return kzalloc(size, gfp);
94}
95
96static inline void percpu_free(void *__pdata)
97{
98 kfree(__pdata);
99}
100
101#endif /* CONFIG_SMP */
102
103#define percpu_alloc_mask(size, gfp, mask) \
104 __percpu_alloc_mask((size), (gfp), &(mask))
105
106#define percpu_alloc(size, gfp) percpu_alloc_mask((size), (gfp), cpu_online_map)
107
108/* (legacy) interface for use without CPU hotplug handling */
109
110#define __alloc_percpu(size) percpu_alloc_mask((size), GFP_KERNEL, \
111 cpu_possible_map)
112#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type))
113#define free_percpu(ptr) percpu_free((ptr))
114#define per_cpu_ptr(ptr, cpu) percpu_ptr((ptr), (cpu))
115
116#endif /* __LINUX_PERCPU_H */