[J-u-boot.git] / include / linux / rbtree.h

/* SPDX-License-Identifier: GPL-2.0+ */
/*
  Red Black Trees
  (C) 1999  Andrea Arcangeli <[email protected]>
  
  linux/include/linux/rbtree.h

  To use rbtrees you'll have to implement your own insert and search cores.
  This will avoid us to use callbacks and to drop drammatically performances.
  I know it's not the cleaner way,  but in C (not in C++) to get
  performances and genericity...

  See Documentation/rbtree.txt for documentation and samples.
*/

#ifndef	_LINUX_RBTREE_H
#define	_LINUX_RBTREE_H

#ifndef __UBOOT__
#include <linux/kernel.h>
#endif
#include <linux/stddef.h>

struct rb_node {
	unsigned long  __rb_parent_color;
	struct rb_node *rb_right;
	struct rb_node *rb_left;
} __attribute__((aligned(sizeof(long))));
    /* The alignment might seem pointless, but allegedly CRIS needs it */

struct rb_root {
	struct rb_node *rb_node;
};


#define rb_parent(r)   ((struct rb_node *)((r)->__rb_parent_color & ~3))

#define RB_ROOT	(struct rb_root) { NULL, }
#define	rb_entry(ptr, type, member) container_of(ptr, type, member)

#define RB_EMPTY_ROOT(root)  ((root)->rb_node == NULL)

/* 'empty' nodes are nodes that are known not to be inserted in an rbree */
#define RB_EMPTY_NODE(node)  \
	((node)->__rb_parent_color == (unsigned long)(node))
#define RB_CLEAR_NODE(node)  \
	((node)->__rb_parent_color = (unsigned long)(node))


extern void rb_insert_color(struct rb_node *, struct rb_root *);
extern void rb_erase(struct rb_node *, struct rb_root *);


/* Find logical next and previous nodes in a tree */
extern struct rb_node *rb_next(const struct rb_node *);
extern struct rb_node *rb_prev(const struct rb_node *);
extern struct rb_node *rb_first(const struct rb_root *);
extern struct rb_node *rb_last(const struct rb_root *);

/* Postorder iteration - always visit the parent after its children */
extern struct rb_node *rb_first_postorder(const struct rb_root *);
extern struct rb_node *rb_next_postorder(const struct rb_node *);

/* Fast replacement of a single node without remove/rebalance/add/rebalance */
extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, 
			    struct rb_root *root);

static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
				struct rb_node ** rb_link)
{
	node->__rb_parent_color = (unsigned long)parent;
	node->rb_left = node->rb_right = NULL;

	*rb_link = node;
}

#define rb_entry_safe(ptr, type, member) \
	({ typeof(ptr) ____ptr = (ptr); \
	   ____ptr ? rb_entry(____ptr, type, member) : NULL; \
	})

/**
 * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of
 * given type safe against removal of rb_node entry
 *
 * @pos:	the 'type *' to use as a loop cursor.
 * @n:		another 'type *' to use as temporary storage
 * @root:	'rb_root *' of the rbtree.
 * @field:	the name of the rb_node field within 'type'.
 */
#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
	for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \
	     pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \
			typeof(*pos), field); 1; }); \
	     pos = n)

#endif	/* _LINUX_RBTREE_H */
Commit	Line	Data
83d290c5	1	/* SPDX-License-Identifier: GPL-2.0+ */
7ba890bf KP	2	/*
	3	Red Black Trees
	4	(C) 1999 Andrea Arcangeli <[email protected]>
9dd228b5	5
7ba890bf KP	6	linux/include/linux/rbtree.h
	7
	8	To use rbtrees you'll have to implement your own insert and search cores.
	9	This will avoid us to use callbacks and to drop drammatically performances.
	10	I know it's not the cleaner way, but in C (not in C++) to get
	11	performances and genericity...
	12
9dd228b5	13	See Documentation/rbtree.txt for documentation and samples.
7ba890bf KP	14	*/
	15
	16	#ifndef _LINUX_RBTREE_H
	17	#define _LINUX_RBTREE_H
	18
9dd228b5 HS	19	#ifndef __UBOOT__
	20	#include <linux/kernel.h>
	21	#endif
7ba890bf KP	22	#include <linux/stddef.h>
7ba890bf KP	23
9dd228b5 HS	24	struct rb_node {
9dd228b5 HS	25	unsigned long __rb_parent_color;
7ba890bf KP	26	struct rb_node *rb_right;
	27	struct rb_node *rb_left;
	28	} __attribute__((aligned(sizeof(long))));
	29	/* The alignment might seem pointless, but allegedly CRIS needs it */
	30
9dd228b5	31	struct rb_root {
7ba890bf KP	32	struct rb_node *rb_node;
	33	};
	34
	35
9dd228b5	36	#define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3))
7ba890bf KP	37
	38	#define RB_ROOT (struct rb_root) { NULL, }
	39	#define rb_entry(ptr, type, member) container_of(ptr, type, member)
	40
9dd228b5 HS	41	#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
	42
	43	/* 'empty' nodes are nodes that are known not to be inserted in an rbree */
	44	#define RB_EMPTY_NODE(node) \
	45	((node)->__rb_parent_color == (unsigned long)(node))
	46	#define RB_CLEAR_NODE(node) \
	47	((node)->__rb_parent_color = (unsigned long)(node))
	48
7ba890bf KP	49
	50	extern void rb_insert_color(struct rb_node , struct rb_root );
	51	extern void rb_erase(struct rb_node , struct rb_root );
	52
9dd228b5	53
7ba890bf	54	/* Find logical next and previous nodes in a tree */
9dd228b5 HS	55	extern struct rb_node rb_next(const struct rb_node );
	56	extern struct rb_node rb_prev(const struct rb_node );
	57	extern struct rb_node rb_first(const struct rb_root );
	58	extern struct rb_node rb_last(const struct rb_root );
	59
	60	/* Postorder iteration - always visit the parent after its children */
	61	extern struct rb_node rb_first_postorder(const struct rb_root );
	62	extern struct rb_node rb_next_postorder(const struct rb_node );
7ba890bf KP	63
7ba890bf KP	64	/* Fast replacement of a single node without remove/rebalance/add/rebalance */
9dd228b5	65	extern void rb_replace_node(struct rb_node victim, struct rb_node new,
7ba890bf KP	66	struct rb_root *root);
	67
	68	static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
	69	struct rb_node ** rb_link)
	70	{
9dd228b5	71	node->__rb_parent_color = (unsigned long)parent;
7ba890bf KP	72	node->rb_left = node->rb_right = NULL;
	73
	74	*rb_link = node;
	75	}
	76
9dd228b5 HS	77	#define rb_entry_safe(ptr, type, member) \
	78	({ typeof(ptr) ____ptr = (ptr); \
	79	____ptr ? rb_entry(____ptr, type, member) : NULL; \
	80	})
	81
	82	/**
	83	* rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of
	84	* given type safe against removal of rb_node entry
	85	*
	86	* @pos: the 'type *' to use as a loop cursor.
	87	* @n: another 'type *' to use as temporary storage
	88	* @root: 'rb_root *' of the rbtree.
	89	* @field: the name of the rb_node field within 'type'.
	90	*/
	91	#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
	92	for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos), field); \
	93	pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \
	94	typeof(*pos), field); 1; }); \
	95	pos = n)
	96
7ba890bf	97	#endif /* _LINUX_RBTREE_H */