diff options
Diffstat (limited to 'include/linux/once_lite.h')
-rw-r--r-- | include/linux/once_lite.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/include/linux/once_lite.h b/include/linux/once_lite.h new file mode 100644 index 000000000000..b7bce4983638 --- /dev/null +++ b/include/linux/once_lite.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_ONCE_LITE_H +#define _LINUX_ONCE_LITE_H + +#include <linux/types.h> + +/* Call a function once. Similar to DO_ONCE(), but does not use jump label + * patching via static keys. + */ +#define DO_ONCE_LITE(func, ...) \ + DO_ONCE_LITE_IF(true, func, ##__VA_ARGS__) + +#define __ONCE_LITE_IF(condition) \ + ({ \ + static bool __section(".data.once") __already_done; \ + bool __ret_cond = !!(condition); \ + bool __ret_once = false; \ + \ + if (unlikely(__ret_cond && !__already_done)) { \ + __already_done = true; \ + __ret_once = true; \ + } \ + unlikely(__ret_once); \ + }) + +#define DO_ONCE_LITE_IF(condition, func, ...) \ + ({ \ + bool __ret_do_once = !!(condition); \ + \ + if (__ONCE_LITE_IF(__ret_do_once)) \ + func(__VA_ARGS__); \ + \ + unlikely(__ret_do_once); \ + }) + +#endif /* _LINUX_ONCE_LITE_H */ |