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
68 struct 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
84 extern void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask);
85 extern void percpu_free(void *__pdata);
86
87 #else /* CONFIG_SMP */
88
89 #define percpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
90
__percpu_alloc_mask(size_t size,gfp_t gfp,cpumask_t * mask)91 static __always_inline void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask)
92 {
93 return kzalloc(size, gfp);
94 }
95
percpu_free(void * __pdata)96 static 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 */
117