include/linux/once.h

   1 #ifndef _LINUX_ONCE_H
   2 #define _LINUX_ONCE_H
   3
   4 #include <linux/types.h>
   5 #include <linux/jump_label.h>
   6
   7 bool __get_random_once(void *buf, int nbytes, bool *done,
   8                        struct static_key *once_key);
   9
  10 #define get_random_once(buf, nbytes)                                    \
  11         ({                                                              \
  12                 bool ___ret = false;                                    \
  13                 static bool ___done = false;                            \
  14                 static struct static_key ___once_key =                  \
  15                         STATIC_KEY_INIT_TRUE;                           \
  16                 if (static_key_true(&___once_key))                      \
  17                         ___ret = __get_random_once((buf),               \
  18                                                    (nbytes),            \
  19                                                    &___done,            \
  20                                                    &___once_key);       \
  21                 ___ret;                                                 \
  22         })
  23
  24 #endif /* _LINUX_ONCE_H */