| 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 | 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 | /* Weird cast keeps both GCC and sparse happy. */ |
| 45 | #define SHIFT_PERCPU_PTR(__p, __offset) ({ \ |
| 46 | __verify_pcpu_ptr((__p)); \ |
| 47 | RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset)); \ |
| 48 | }) |
| 49 | #endif |
| 50 | |
| 51 | /* |
| 52 | * A percpu variable may point to a discarded regions. The following are |
| 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(&(var), per_cpu_offset(cpu))) |
| 58 | |
| 59 | #ifndef __this_cpu_ptr |
| 60 | #define __this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset) |
| 61 | #endif |
| 62 | #ifdef CONFIG_DEBUG_PREEMPT |
| 63 | #define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset) |
| 64 | #else |
| 65 | #define this_cpu_ptr(ptr) __this_cpu_ptr(ptr) |
| 66 | #endif |
| 67 | |
| 68 | #define __get_cpu_var(var) (*this_cpu_ptr(&(var))) |
| 69 | #define __raw_get_cpu_var(var) (*__this_cpu_ptr(&(var))) |
| 70 | |
| 71 | #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA |
| 72 | extern void setup_per_cpu_areas(void); |
| 73 | #endif |
| 74 | |
| 75 | #else /* ! SMP */ |
| 76 | |
| 77 | #define VERIFY_PERCPU_PTR(__p) ({ \ |
| 78 | __verify_pcpu_ptr((__p)); \ |
| 79 | (typeof(*(__p)) __kernel __force *)(__p); \ |
| 80 | }) |
| 81 | |
| 82 | #define per_cpu(var, cpu) (*((void)(cpu), VERIFY_PERCPU_PTR(&(var)))) |
| 83 | #define __get_cpu_var(var) (*VERIFY_PERCPU_PTR(&(var))) |
| 84 | #define __raw_get_cpu_var(var) (*VERIFY_PERCPU_PTR(&(var))) |
| 85 | #define this_cpu_ptr(ptr) per_cpu_ptr(ptr, 0) |
| 86 | #define __this_cpu_ptr(ptr) this_cpu_ptr(ptr) |
| 87 | |
| 88 | #endif /* SMP */ |
| 89 | |
| 90 | #ifndef PER_CPU_BASE_SECTION |
| 91 | #ifdef CONFIG_SMP |
| 92 | #define PER_CPU_BASE_SECTION ".data..percpu" |
| 93 | #else |
| 94 | #define PER_CPU_BASE_SECTION ".data" |
| 95 | #endif |
| 96 | #endif |
| 97 | |
| 98 | #ifdef CONFIG_SMP |
| 99 | |
| 100 | #ifdef MODULE |
| 101 | #define PER_CPU_SHARED_ALIGNED_SECTION "" |
| 102 | #define PER_CPU_ALIGNED_SECTION "" |
| 103 | #else |
| 104 | #define PER_CPU_SHARED_ALIGNED_SECTION "..shared_aligned" |
| 105 | #define PER_CPU_ALIGNED_SECTION "..shared_aligned" |
| 106 | #endif |
| 107 | #define PER_CPU_FIRST_SECTION "..first" |
| 108 | |
| 109 | #else |
| 110 | |
| 111 | #define PER_CPU_SHARED_ALIGNED_SECTION "" |
| 112 | #define PER_CPU_ALIGNED_SECTION "..shared_aligned" |
| 113 | #define PER_CPU_FIRST_SECTION "" |
| 114 | |
| 115 | #endif |
| 116 | |
| 117 | #ifndef PER_CPU_ATTRIBUTES |
| 118 | #define PER_CPU_ATTRIBUTES |
| 119 | #endif |
| 120 | |
| 121 | #ifndef PER_CPU_DEF_ATTRIBUTES |
| 122 | #define PER_CPU_DEF_ATTRIBUTES |
| 123 | #endif |
| 124 | |
| 125 | #endif /* _ASM_GENERIC_PERCPU_H_ */ |