libringbuffer/smp.h

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  */
   6
   7 #ifndef _LIBRINGBUFFER_SMP_H
   8 #define _LIBRINGBUFFER_SMP_H
   9
  10 #include "getcpu.h"
  11
  12 /*
  13  * 4kB of per-cpu data available. Enough to hold the control structures,
  14  * but not ring buffers.
  15  */
  16 #define PER_CPU_MEM_SIZE        4096
  17
  18 extern int __num_possible_cpus;
  19 extern void _get_num_possible_cpus(void);
  20
  21 static inline
  22 int num_possible_cpus(void)
  23 {
  24         if (!__num_possible_cpus)
  25                 _get_num_possible_cpus();
  26         return __num_possible_cpus;
  27 }
  28
  29 #define for_each_possible_cpu(cpu)              \
  30         for ((cpu) = 0; (cpu) < num_possible_cpus(); (cpu)++)
  31
  32 #endif /* _LIBRINGBUFFER_SMP_H */