projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 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 | |
| 44 | #define SHIFT_PERCPU_PTR(__p, __offset) RELOC_HIDE((__p), (__offset)) | |
| 45 | #endif | |
| a875a69f | 46 | |
| acdac872 | 47 | /* |
| dd5af90a | 48 | * A percpu variable may point to a discarded regions. The following are |
| acdac872 | 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 | ||
| dd5af90a | 60 | #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA |
| acdac872 | 61 | extern void setup_per_cpu_areas(void); |
| 62 | #endif | |
| 1da177e4 | 63 | |
| 1da177e4 LT |
64 | #else /* ! SMP */ |
| 65 | ||
| acdac872 | 66 | #define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var))) |
| 67 | #define __get_cpu_var(var) per_cpu_var(var) | |
| 68 | #define __raw_get_cpu_var(var) per_cpu_var(var) | |
| 1da177e4 LT |
69 | |
| 70 | #endif /* SMP */ | |
| 71 | ||
| 9b8de747 DH |
72 | #ifndef PER_CPU_BASE_SECTION |
| 73 | #ifdef CONFIG_SMP | |
| 74 | #define PER_CPU_BASE_SECTION ".data.percpu" | |
| 75 | #else | |
| 76 | #define PER_CPU_BASE_SECTION ".data" | |
| 77 | #endif | |
| 78 | #endif | |
| 79 | ||
| 80 | #ifdef CONFIG_SMP | |
| 81 | ||
| 82 | #ifdef MODULE | |
| 83 | #define PER_CPU_SHARED_ALIGNED_SECTION "" | |
| 84 | #else | |
| 85 | #define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned" | |
| 86 | #endif | |
| 87 | #define PER_CPU_FIRST_SECTION ".first" | |
| 88 | ||
| 89 | #else | |
| 90 | ||
| 91 | #define PER_CPU_SHARED_ALIGNED_SECTION "" | |
| 92 | #define PER_CPU_FIRST_SECTION "" | |
| 93 | ||
| 94 | #endif | |
| 95 | ||
| acdac872 | 96 | #ifndef PER_CPU_ATTRIBUTES |
| 97 | #define PER_CPU_ATTRIBUTES | |
| 98 | #endif | |
| 99 | ||
| 1da177e4 | 100 | #endif /* _ASM_GENERIC_PERCPU_H_ */ |