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_ */ 126