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1da177e4 LT |
1 | #ifndef _ASM_GENERIC_PERCPU_H_ |
2 | #define _ASM_GENERIC_PERCPU_H_ | |
5028eaa9 | 3 | |
1da177e4 | 4 | #include <linux/compiler.h> |
ae1ee11b | 5 | #include <linux/threads.h> |
5028eaa9 | 6 | #include <linux/percpu-defs.h> |
acdac872 | 7 | |
1da177e4 LT |
8 | #ifdef CONFIG_SMP |
9 | ||
acdac872 | 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 | |
1da177e4 LT |
18 | extern unsigned long __per_cpu_offset[NR_CPUS]; |
19 | ||
a875a69f | 20 | #define per_cpu_offset(x) (__per_cpu_offset[x]) |
acdac872 | 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()) | |
1e835278 HD |
31 | #endif |
32 | #ifdef CONFIG_DEBUG_PREEMPT | |
acdac872 | 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 | |
e0fdb0e0 | 44 | /* Weird cast keeps both GCC and sparse happy. */ |
545695fb TH |
45 | #define SHIFT_PERCPU_PTR(__p, __offset) ({ \ |
46 | __verify_pcpu_ptr((__p)); \ | |
47 | RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset)); \ | |
48 | }) | |
acdac872 | 49 | #endif |
a875a69f | 50 | |
acdac872 | 51 | /* |
dd5af90a | 52 | * A percpu variable may point to a discarded regions. The following are |
acdac872 | 53 | * established ways to produce a usable pointer from the percpu variable |
54 | * offset. | |
55 | */ | |
56 | #define per_cpu(var, cpu) \ | |
dd17c8f7 | 57 | (*SHIFT_PERCPU_PTR(&(var), per_cpu_offset(cpu))) |
acdac872 | 58 | #define __get_cpu_var(var) \ |
dd17c8f7 | 59 | (*SHIFT_PERCPU_PTR(&(var), my_cpu_offset)) |
acdac872 | 60 | #define __raw_get_cpu_var(var) \ |
dd17c8f7 | 61 | (*SHIFT_PERCPU_PTR(&(var), __my_cpu_offset)) |
acdac872 | 62 | |
7340a0b1 CL |
63 | #define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset) |
64 | #define __this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset) | |
65 | ||
acdac872 | 66 | |
dd5af90a | 67 | #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA |
acdac872 | 68 | extern void setup_per_cpu_areas(void); |
69 | #endif | |
1da177e4 | 70 | |
1da177e4 LT |
71 | #else /* ! SMP */ |
72 | ||
dd17c8f7 RR |
73 | #define per_cpu(var, cpu) (*((void)(cpu), &(var))) |
74 | #define __get_cpu_var(var) (var) | |
75 | #define __raw_get_cpu_var(var) (var) | |
7340a0b1 CL |
76 | #define this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0) |
77 | #define __this_cpu_ptr(ptr) this_cpu_ptr(ptr) | |
1da177e4 LT |
78 | |
79 | #endif /* SMP */ | |
80 | ||
9b8de747 DH |
81 | #ifndef PER_CPU_BASE_SECTION |
82 | #ifdef CONFIG_SMP | |
3d9a854c | 83 | #define PER_CPU_BASE_SECTION ".data..percpu" |
9b8de747 DH |
84 | #else |
85 | #define PER_CPU_BASE_SECTION ".data" | |
86 | #endif | |
87 | #endif | |
88 | ||
89 | #ifdef CONFIG_SMP | |
90 | ||
91 | #ifdef MODULE | |
92 | #define PER_CPU_SHARED_ALIGNED_SECTION "" | |
53f82452 | 93 | #define PER_CPU_ALIGNED_SECTION "" |
9b8de747 | 94 | #else |
3d9a854c DV |
95 | #define PER_CPU_SHARED_ALIGNED_SECTION "..shared_aligned" |
96 | #define PER_CPU_ALIGNED_SECTION "..shared_aligned" | |
9b8de747 | 97 | #endif |
3d9a854c | 98 | #define PER_CPU_FIRST_SECTION "..first" |
9b8de747 DH |
99 | |
100 | #else | |
101 | ||
102 | #define PER_CPU_SHARED_ALIGNED_SECTION "" | |
3d9a854c | 103 | #define PER_CPU_ALIGNED_SECTION "..shared_aligned" |
9b8de747 DH |
104 | #define PER_CPU_FIRST_SECTION "" |
105 | ||
106 | #endif | |
107 | ||
acdac872 | 108 | #ifndef PER_CPU_ATTRIBUTES |
109 | #define PER_CPU_ATTRIBUTES | |
110 | #endif | |
111 | ||
b01e8dc3 TH |
112 | #ifndef PER_CPU_DEF_ATTRIBUTES |
113 | #define PER_CPU_DEF_ATTRIBUTES | |
114 | #endif | |
115 | ||
1da177e4 | 116 | #endif /* _ASM_GENERIC_PERCPU_H_ */ |