linux/include/linux/rbtree_types.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _LINUX_RBTREE_TYPES_H
#define _LINUX_RBTREE_TYPES_H

struct rb_node { … } __attribute__((aligned …));
/* The alignment might seem pointless, but allegedly CRIS needs it */

struct rb_root { … };

/*
 * Leftmost-cached rbtrees.
 *
 * We do not cache the rightmost node based on footprint
 * size vs number of potential users that could benefit
 * from O(1) rb_last(). Just not worth it, users that want
 * this feature can always implement the logic explicitly.
 * Furthermore, users that want to cache both pointers may
 * find it a bit asymmetric, but that's ok.
 */
struct rb_root_cached { … };

#define RB_ROOT …
#define RB_ROOT_CACHED …

#endif