vm_radix.h revision 238245
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_STACK 8 /* Nodes to store on stack. */ 33 34/* 35 * Radix tree root. The height and pointer are set together to permit 36 * coherent lookups while the root is modified. 37 */ 38struct vm_radix { 39 uintptr_t rt_root; /* root + height */ 40}; 41 42#ifdef _KERNEL 43 44void vm_radix_init(void); 45int vm_radix_insert(struct vm_radix *, vm_pindex_t, void *); 46void *vm_radix_lookup(struct vm_radix *, vm_pindex_t); 47int vm_radix_lookupn(struct vm_radix *, vm_pindex_t, vm_pindex_t, void **, 48 int, vm_pindex_t *, u_int *); 49void *vm_radix_lookup_le(struct vm_radix *, vm_pindex_t); 50void vm_radix_reclaim_allnodes(struct vm_radix *); 51void vm_radix_remove(struct vm_radix *, vm_pindex_t); 52 53/* 54 * Look up any entry at a position greater or equal to index. 55 */ 56static inline void * 57vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index) 58{ 59 void *val; 60 u_int dummy; 61 62 if (vm_radix_lookupn(rtree, index, 0, &val, 1, &index, &dummy)) 63 return (val); 64 return (NULL); 65} 66 67static inline void * 68vm_radix_last(struct vm_radix *rtree) 69{ 70 71 return vm_radix_lookup_le(rtree, 0); 72} 73 74static inline void * 75vm_radix_first(struct vm_radix *rtree) 76{ 77 78 return vm_radix_lookup_ge(rtree, 0); 79} 80 81static inline void * 82vm_radix_next(struct vm_radix *rtree, vm_pindex_t index) 83{ 84 85 if (index == -1) 86 return (NULL); 87 return vm_radix_lookup_ge(rtree, index + 1); 88} 89 90static inline void * 91vm_radix_prev(struct vm_radix *rtree, vm_pindex_t index) 92{ 93 94 if (index == 0) 95 return (NULL); 96 return vm_radix_lookup_le(rtree, index - 1); 97} 98 99#endif /* _KERNEL */ 100#endif /* !_VM_RADIX_H_ */ 101