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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __LINUX_PERCPU_H
2#define __LINUX_PERCPU_H
Martin Peschke7ff6f082006-09-25 23:31:21 -07003
Robert P. J. Day0a3021f2007-07-15 23:39:57 -07004#include <linux/preempt.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/slab.h> /* For kmalloc() */
6#include <linux/smp.h>
7#include <linux/string.h> /* For memset() */
Martin Peschke7ff6f082006-09-25 23:31:21 -07008#include <linux/cpumask.h>
9
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <asm/percpu.h>
11
12/* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */
13#ifndef PERCPU_ENOUGH_ROOM
Jeremy Fitzhardingeb00742d32007-05-02 19:27:11 +020014#ifdef CONFIG_MODULES
15#define PERCPU_MODULE_RESERVE 8192
16#else
17#define PERCPU_MODULE_RESERVE 0
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#endif
19
Jeremy Fitzhardingeb00742d32007-05-02 19:27:11 +020020#define PERCPU_ENOUGH_ROOM \
21 (__per_cpu_end - __per_cpu_start + PERCPU_MODULE_RESERVE)
22#endif /* PERCPU_ENOUGH_ROOM */
23
Jan Blunck632bbfe2006-09-25 23:30:53 -070024/*
25 * Must be an lvalue. Since @var must be a simple identifier,
26 * we force a syntax error here if it isn't.
27 */
28#define get_cpu_var(var) (*({ \
Jan Bluncka666ecf2006-10-06 00:43:58 -070029 extern int simple_identifier_##var(void); \
Jan Blunck632bbfe2006-09-25 23:30:53 -070030 preempt_disable(); \
31 &__get_cpu_var(var); }))
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#define put_cpu_var(var) preempt_enable()
33
34#ifdef CONFIG_SMP
35
36struct percpu_data {
37 void *ptrs[NR_CPUS];
Linus Torvalds1da177e2005-04-16 15:20:36 -070038};
39
Martin Peschke7ff6f082006-09-25 23:31:21 -070040#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -070041/*
Martin Peschke7ff6f082006-09-25 23:31:21 -070042 * Use this to get to a cpu's version of the per-cpu object dynamically
43 * allocated. Non-atomic access to the current CPU's version should
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 * probably be combined with get_cpu()/put_cpu().
45 */
Martin Peschke7ff6f082006-09-25 23:31:21 -070046#define percpu_ptr(ptr, cpu) \
47({ \
48 struct percpu_data *__p = __percpu_disguise(ptr); \
49 (__typeof__(ptr))__p->ptrs[(cpu)]; \
Linus Torvalds1da177e2005-04-16 15:20:36 -070050})
51
Martin Peschke7ff6f082006-09-25 23:31:21 -070052extern void *percpu_populate(void *__pdata, size_t size, gfp_t gfp, int cpu);
53extern void percpu_depopulate(void *__pdata, int cpu);
54extern int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
55 cpumask_t *mask);
56extern void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask);
57extern void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask);
58extern void percpu_free(void *__pdata);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60#else /* CONFIG_SMP */
61
Martin Peschke7ff6f082006-09-25 23:31:21 -070062#define percpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Martin Peschke7ff6f082006-09-25 23:31:21 -070064static inline void percpu_depopulate(void *__pdata, int cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -070065{
Linus Torvalds1da177e2005-04-16 15:20:36 -070066}
Martin Peschke7ff6f082006-09-25 23:31:21 -070067
68static inline void __percpu_depopulate_mask(void *__pdata, cpumask_t *mask)
69{
70}
71
72static inline void *percpu_populate(void *__pdata, size_t size, gfp_t gfp,
73 int cpu)
74{
75 return percpu_ptr(__pdata, cpu);
76}
77
78static inline int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
79 cpumask_t *mask)
80{
81 return 0;
82}
83
Al Viro0891a8d2006-09-29 01:58:34 -070084static __always_inline void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
Martin Peschke7ff6f082006-09-25 23:31:21 -070085{
86 return kzalloc(size, gfp);
87}
88
89static inline void percpu_free(void *__pdata)
90{
91 kfree(__pdata);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092}
93
94#endif /* CONFIG_SMP */
95
Martin Peschke7ff6f082006-09-25 23:31:21 -070096#define percpu_populate_mask(__pdata, size, gfp, mask) \
97 __percpu_populate_mask((__pdata), (size), (gfp), &(mask))
98#define percpu_depopulate_mask(__pdata, mask) \
99 __percpu_depopulate_mask((__pdata), &(mask))
100#define percpu_alloc_mask(size, gfp, mask) \
101 __percpu_alloc_mask((size), (gfp), &(mask))
102
103#define percpu_alloc(size, gfp) percpu_alloc_mask((size), (gfp), cpu_online_map)
104
105/* (legacy) interface for use without CPU hotplug handling */
106
107#define __alloc_percpu(size) percpu_alloc_mask((size), GFP_KERNEL, \
108 cpu_possible_map)
109#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type))
110#define free_percpu(ptr) percpu_free((ptr))
111#define per_cpu_ptr(ptr, cpu) percpu_ptr((ptr), (cpu))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
113#endif /* __LINUX_PERCPU_H */