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 
39 struct radix_tree_node {
40 	void		*slots[RADIX_TREE_MAP_SIZE];
41 	int		count;
42 };
43 
44 struct 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 
57 void	*radix_tree_lookup(struct radix_tree_root *, unsigned long);
58 void	*radix_tree_delete(struct radix_tree_root *, unsigned long);
59 int	radix_tree_insert(struct radix_tree_root *, unsigned long, void *);
60 
61 #endif	/* _LINUX_RADIX_TREE_H_ */
62