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 18extern 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 72extern 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