include/asm-generic/percpu.h

   1 #ifndef _ASM_GENERIC_PERCPU_H_
   2 #define _ASM_GENERIC_PERCPU_H_
   3 #include <linux/compiler.h>
   4 #include <linux/threads.h>
   5
   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
  12 #ifdef CONFIG_SMP
  13
  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
  22 extern unsigned long __per_cpu_offset[NR_CPUS];
  23
  24 #define per_cpu_offset(x) (__per_cpu_offset[x])
  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())
  35 <<<<<<< HEAD:include/asm-generic/percpu.h
  36 =======
  37 #endif
  38 #ifdef CONFIG_DEBUG_PREEMPT
  39 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:include/asm-generic/percpu.h
  40 #define my_cpu_offset per_cpu_offset(smp_processor_id())
  41 #else
  42 #define my_cpu_offset __my_cpu_offset
  43 #endif
  44
  45 /*
  46  * Add a offset to a pointer but keep the pointer as is.
  47  *
  48  * Only S390 provides its own means of moving the pointer.
  49  */
  50 #ifndef SHIFT_PERCPU_PTR
  51 #define SHIFT_PERCPU_PTR(__p, __offset) RELOC_HIDE((__p), (__offset))
  52 #endif
  53
  54 /*
  55  * A percpu variable may point to a discarded regions. The following are
  56  * established ways to produce a usable pointer from the percpu variable
  57  * offset.
  58  */
  59 #define per_cpu(var, cpu) \
  60         (*SHIFT_PERCPU_PTR(&per_cpu_var(var), per_cpu_offset(cpu)))
  61 #define __get_cpu_var(var) \
  62         (*SHIFT_PERCPU_PTR(&per_cpu_var(var), my_cpu_offset))
  63 #define __raw_get_cpu_var(var) \
  64         (*SHIFT_PERCPU_PTR(&per_cpu_var(var), __my_cpu_offset))
  65
  66
  67 #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
  68 extern void setup_per_cpu_areas(void);
  69 #endif
  70
  71 #else /* ! SMP */
  72
  73 #define per_cpu(var, cpu)                       (*((void)(cpu), &per_cpu_var(var)))
  74 #define __get_cpu_var(var)                      per_cpu_var(var)
  75 #define __raw_get_cpu_var(var)                  per_cpu_var(var)
  76
  77 #endif  /* SMP */
  78
  79 #ifndef PER_CPU_ATTRIBUTES
  80 #define PER_CPU_ATTRIBUTES
  81 #endif
  82
  83 #define DECLARE_PER_CPU(type, name) extern PER_CPU_ATTRIBUTES \
  84                                         __typeof__(type) per_cpu_var(name)
  85
  86 #endif /* _ASM_GENERIC_PERCPU_H_ */