include/linux/once_lite.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_ONCE_LITE_H
   3 #define _LINUX_ONCE_LITE_H
   4
   5 #include <linux/types.h>
   6
   7 /* Call a function once. Similar to DO_ONCE(), but does not use jump label
   8  * patching via static keys.
   9  */
  10 #define DO_ONCE_LITE(func, ...)                                         \
  11         DO_ONCE_LITE_IF(true, func, ##__VA_ARGS__)
  12 #define DO_ONCE_LITE_IF(condition, func, ...)                           \
  13         ({                                                              \
  14                 static bool __section(".data.once") __already_done;     \
  15                 bool __ret_do_once = !!(condition);                     \
  16                                                                         \
  17                 if (unlikely(__ret_do_once && !__already_done)) {       \
  18                         __already_done = true;                          \
  19                         func(__VA_ARGS__);                              \
  20                 }                                                       \
  21                 unlikely(__ret_do_once);                                \
  22         })
  23
  24 #endif /* _LINUX_ONCE_LITE_H */