Line data Source code
1 : #ifndef _ASM_GENERIC_PERCPU_H_
2 : #define _ASM_GENERIC_PERCPU_H_
3 :
4 : #include <linux/compiler.h>
5 : #include <linux/threads.h>
6 : #include <linux/percpu-defs.h>
7 :
8 : #ifdef CONFIG_SMP
9 :
10 : /*
11 : * per_cpu_offset() is the offset that has to be added to a
12 : * percpu variable to get to the instance for a certain processor.
13 : *
14 : * Most arches use the __per_cpu_offset array for those offsets but
15 : * some arches have their own ways of determining the offset (x86_64, s390).
16 : */
17 : #ifndef __per_cpu_offset
18 1 : extern unsigned long __per_cpu_offset[NR_CPUS];
19 :
20 : #define per_cpu_offset(x) (__per_cpu_offset[x])
21 : #endif
22 :
23 : /*
24 : * Determine the offset for the currently active processor.
25 : * An arch may define __my_cpu_offset to provide a more effective
26 : * means of obtaining the offset to the per cpu variables of the
27 : * current processor.
28 : */
29 : #ifndef __my_cpu_offset
30 : #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id())
31 : #endif
32 : #ifdef CONFIG_DEBUG_PREEMPT
33 : #define my_cpu_offset per_cpu_offset(smp_processor_id())
34 : #else
35 : #define my_cpu_offset __my_cpu_offset
36 : #endif
37 :
38 : /*
39 : * Add a offset to a pointer but keep the pointer as is.
40 : *
41 : * Only S390 provides its own means of moving the pointer.
42 : */
43 : #ifndef SHIFT_PERCPU_PTR
44 : #define SHIFT_PERCPU_PTR(__p, __offset) RELOC_HIDE((__p), (__offset))
45 : #endif
46 :
47 : /*
48 : * A percpu variable may point to a discarded regions. The following are
49 : * established ways to produce a usable pointer from the percpu variable
50 : * offset.
51 : */
52 : #define per_cpu(var, cpu) \
53 : (*SHIFT_PERCPU_PTR(&per_cpu_var(var), per_cpu_offset(cpu)))
54 : #define __get_cpu_var(var) \
55 : (*SHIFT_PERCPU_PTR(&per_cpu_var(var), my_cpu_offset))
56 : #define __raw_get_cpu_var(var) \
57 : (*SHIFT_PERCPU_PTR(&per_cpu_var(var), __my_cpu_offset))
58 :
59 : #define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset)
60 : #define __this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset)
61 :
62 :
63 : #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
64 : extern void setup_per_cpu_areas(void);
65 : #endif
66 :
67 : #else /* ! SMP */
68 :
69 : #define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var)))
70 : #define __get_cpu_var(var) per_cpu_var(var)
71 : #define __raw_get_cpu_var(var) per_cpu_var(var)
72 : #define this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0)
73 : #define __this_cpu_ptr(ptr) this_cpu_ptr(ptr)
74 :
75 : #endif /* SMP */
76 :
77 : #ifndef PER_CPU_BASE_SECTION
78 : #ifdef CONFIG_SMP
79 : #define PER_CPU_BASE_SECTION ".data.percpu"
80 : #else
81 : #define PER_CPU_BASE_SECTION ".data"
82 : #endif
83 : #endif
84 :
85 : #ifdef CONFIG_SMP
86 :
87 : #ifdef MODULE
88 : #define PER_CPU_SHARED_ALIGNED_SECTION ""
89 : #define PER_CPU_ALIGNED_SECTION ""
90 : #else
91 : #define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned"
92 : #define PER_CPU_ALIGNED_SECTION ".shared_aligned"
93 : #endif
94 : #define PER_CPU_FIRST_SECTION ".first"
95 :
96 : #else
97 :
98 : #define PER_CPU_SHARED_ALIGNED_SECTION ""
99 : #define PER_CPU_ALIGNED_SECTION ".shared_aligned"
100 : #define PER_CPU_FIRST_SECTION ""
101 :
102 : #endif
103 :
104 : #ifndef PER_CPU_ATTRIBUTES
105 : #define PER_CPU_ATTRIBUTES
106 : #endif
107 :
108 : #ifndef PER_CPU_DEF_ATTRIBUTES
109 : #define PER_CPU_DEF_ATTRIBUTES
110 : #endif
111 :
112 : #endif /* _ASM_GENERIC_PERCPU_H_ */
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