container_of.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef _TOOLS_LINUX_CONTAINER_OF_H
 3#define _TOOLS_LINUX_CONTAINER_OF_H
 4
 5#ifndef container_of
 6/**
 7 * container_of - cast a member of a structure out to the containing structure
 8 * @ptr:	the pointer to the member.
 9 * @type:	the type of the container struct this is embedded in.
10 * @member:	the name of the member within the struct.
11 *
12 */
13#define container_of(ptr, type, member) ({			\
14	const typeof(((type *)0)->member) * __mptr = (ptr);	\
15	(type *)((char *)__mptr - offsetof(type, member)); })
16#endif
17
18#endif	/* _TOOLS_LINUX_CONTAINER_OF_H */