radix-tree.h revision 271127 
1/*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice unmodified, this list of conditions, and the following
13 *    disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#ifndef	_LINUX_RADIX_TREE_H_
31#define	_LINUX_RADIX_TREE_H_
32
33#define	RADIX_TREE_MAP_SHIFT	6
34#define	RADIX_TREE_MAP_SIZE	(1 << RADIX_TREE_MAP_SHIFT)
35#define	RADIX_TREE_MAP_MASK	(RADIX_TREE_MAP_SIZE - 1)
36#define	RADIX_TREE_MAX_HEIGHT						\
37	    DIV_ROUND_UP((sizeof(long) * NBBY), RADIX_TREE_MAP_SHIFT)
38
39struct radix_tree_node {
40	void		*slots[RADIX_TREE_MAP_SIZE];
41	int		count;
42};
43
44struct radix_tree_root {
45	struct radix_tree_node	*rnode;
46	gfp_t			gfp_mask;
47	int			height;
48};
49
50#define	RADIX_TREE_INIT(mask)						\
51	    { .rnode = NULL, .gfp_mask = mask, .height = 0 };
52#define	INIT_RADIX_TREE(root, mask)					\
53	    { (root)->rnode = NULL; (root)->gfp_mask = mask; (root)->height = 0; }
54#define	RADIX_TREE(name, mask)						\
55	    struct radix_tree_root name = RADIX_TREE_INIT(mask)
56
57void	*radix_tree_lookup(struct radix_tree_root *, unsigned long);
58void	*radix_tree_delete(struct radix_tree_root *, unsigned long);
59int	radix_tree_insert(struct radix_tree_root *, unsigned long, void *);
60
61#endif	/* _LINUX_RADIX_TREE_H_ */
62