vm_radix.h revision 236728 
1/*
2 * Copyright (c) 2011 Jeffrey Roberson <jeff@freebsd.org>
3 * Copyright (c) 2008 Mayur Shardul <mayur.shardul@gmail.com>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 */
28
29#ifndef _VM_RADIX_H_
30#define _VM_RADIX_H_
31
32#define	VM_RADIX_BLACK	0x1	/* Black node. (leaf only) */
33#define	VM_RADIX_RED	0x2	/* Red node. (leaf only) */
34#define	VM_RADIX_ANY	(VM_RADIX_RED | VM_RADIX_BLACK)
35#define	VM_RADIX_STACK	8	/* Nodes to store on stack. */
36
37/*
38 * Radix tree root.  The height and pointer are set together to permit
39 * coherent lookups while the root is modified.
40 */
41struct vm_radix {
42	uintptr_t	rt_root;		/* root + height */
43};
44
45#ifdef _KERNEL
46
47/*
48 * Initialize the radix tree subsystem.
49 */
50void	vm_radix_init(void);
51
52/*
53 * Functions which only work with black nodes. (object lock)
54 */
55int 	vm_radix_insert(struct vm_radix *, vm_pindex_t, void *);
56
57/*
58 * Functions which work on specified colors. (object, vm_page_queue_free locks)
59 */
60void	*vm_radix_color(struct vm_radix *, vm_pindex_t, int);
61void	*vm_radix_lookup(struct vm_radix *, vm_pindex_t, int);
62int	vm_radix_lookupn(struct vm_radix *, vm_pindex_t, vm_pindex_t, int,
63	    void **, int, vm_pindex_t *);
64void	*vm_radix_lookup_le(struct vm_radix *, vm_pindex_t, int);
65void	vm_radix_reclaim_allnodes(struct vm_radix *);
66void	vm_radix_remove(struct vm_radix *, vm_pindex_t, int);
67
68/*
69 * Look up any entry at a position greater or equal to index.
70 */
71static inline void *
72vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index, int color)
73{
74        void *val;
75
76        if (vm_radix_lookupn(rtree, index, 0, color, &val, 1, &index))
77                return (val);
78        return (NULL);
79}
80
81static inline void *
82vm_radix_last(struct vm_radix *rtree, int color)
83{
84
85	return vm_radix_lookup_le(rtree, 0, color);
86}
87
88static inline void *
89vm_radix_first(struct vm_radix *rtree, int color)
90{
91
92	return vm_radix_lookup_ge(rtree, 0, color);
93}
94
95static inline void *
96vm_radix_next(struct vm_radix *rtree, vm_pindex_t index, int color)
97{
98
99	if (index == -1)
100		return (NULL);
101	return vm_radix_lookup_ge(rtree, index + 1, color);
102}
103
104static inline void *
105vm_radix_prev(struct vm_radix *rtree, vm_pindex_t index, int color)
106{
107
108	if (index == 0)
109		return (NULL);
110	return vm_radix_lookup_le(rtree, index - 1, color);
111}
112
113#endif /* _KERNEL */
114#endif /* !_VM_RADIX_H_ */
115