projects / mirror_ubuntu-artful-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | #ifndef _ASM_GENERIC_PERCPU_H_ |
| 2 | #define _ASM_GENERIC_PERCPU_H_ | |
| 3 | #include <linux/compiler.h> | |
| ae1ee11b | 4 | #include <linux/threads.h> |
| 1da177e4 | 5 | |
| acdac872 | 6 | /* |
| 7 | * Determine the real variable name from the name visible in the | |
| 8 | * kernel sources. | |
| 9 | */ | |
| 10 | #define per_cpu_var(var) per_cpu__##var | |
| 11 | ||
| 1da177e4 LT |
12 | #ifdef CONFIG_SMP |
| 13 | ||
| acdac872 | 14 | /* |
| 15 | * per_cpu_offset() is the offset that has to be added to a | |
| 16 | * percpu variable to get to the instance for a certain processor. | |
| 17 | * | |
| 18 | * Most arches use the __per_cpu_offset array for those offsets but | |
| 19 | * some arches have their own ways of determining the offset (x86_64, s390). | |
| 20 | */ | |
| 21 | #ifndef __per_cpu_offset | |
| 1da177e4 LT |
22 | extern unsigned long __per_cpu_offset[NR_CPUS]; |
| 23 | ||
| a875a69f | 24 | #define per_cpu_offset(x) (__per_cpu_offset[x]) |
| acdac872 | 25 | #endif |
| 26 | ||
| 27 | /* | |
| 28 | * Determine the offset for the currently active processor. | |
| 29 | * An arch may define __my_cpu_offset to provide a more effective | |
| 30 | * means of obtaining the offset to the per cpu variables of the | |
| 31 | * current processor. | |
| 32 | */ | |
| 33 | #ifndef __my_cpu_offset | |
| 34 | #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id()) | |
| 1e835278 HD |
35 | #endif |
| 36 | #ifdef CONFIG_DEBUG_PREEMPT | |
| acdac872 | 37 | #define my_cpu_offset per_cpu_offset(smp_processor_id()) |
| 38 | #else | |
| 39 | #define my_cpu_offset __my_cpu_offset | |
| 40 | #endif | |
| 41 | ||
| 42 | /* | |
| 43 | * Add a offset to a pointer but keep the pointer as is. | |
| 44 | * | |
| 45 | * Only S390 provides its own means of moving the pointer. | |
| 46 | */ | |
| 47 | #ifndef SHIFT_PERCPU_PTR | |
| 48 | #define SHIFT_PERCPU_PTR(__p, __offset) RELOC_HIDE((__p), (__offset)) | |
| 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) \ | |
| 57 | (*SHIFT_PERCPU_PTR(&per_cpu_var(var), per_cpu_offset(cpu))) | |
| 58 | #define __get_cpu_var(var) \ | |
| 59 | (*SHIFT_PERCPU_PTR(&per_cpu_var(var), my_cpu_offset)) | |
| 60 | #define __raw_get_cpu_var(var) \ | |
| 61 | (*SHIFT_PERCPU_PTR(&per_cpu_var(var), __my_cpu_offset)) | |
| 62 | ||
| 63 | ||
| dd5af90a | 64 | #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA |
| acdac872 | 65 | extern void setup_per_cpu_areas(void); |
| 66 | #endif | |
| 1da177e4 | 67 | |
| 1da177e4 LT |
68 | #else /* ! SMP */ |
| 69 | ||
| acdac872 | 70 | #define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var))) |
| 71 | #define __get_cpu_var(var) per_cpu_var(var) | |
| 72 | #define __raw_get_cpu_var(var) per_cpu_var(var) | |
| 1da177e4 LT |
73 | |
| 74 | #endif /* SMP */ | |
| 75 | ||
| acdac872 | 76 | #ifndef PER_CPU_ATTRIBUTES |
| 77 | #define PER_CPU_ATTRIBUTES | |
| 78 | #endif | |
| 79 | ||
| 80 | #define DECLARE_PER_CPU(type, name) extern PER_CPU_ATTRIBUTES \ | |
| 81 | __typeof__(type) per_cpu_var(name) | |
| 1da177e4 | 82 | |
| 1da177e4 | 83 | #endif /* _ASM_GENERIC_PERCPU_H_ */ |