vm_radix.h revision 228314
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#include <sys/queue.h> 33 34/* Default values of the tree parameters */ 35#define VM_RADIX_WIDTH 5 36#define VM_RADIX_COUNT (1 << VM_RADIX_WIDTH) 37#define VM_RADIX_MASK (VM_RADIX_COUNT - 1) 38#define VM_RADIX_LIMIT howmany((sizeof(vm_pindex_t) * NBBY), VM_RADIX_WIDTH) 39#define VM_RADIX_FLAGS 0x3 /* Flag bits stored in node pointers. */ 40#define VM_RADIX_BLACK 0x1 /* Black node. (leaf only) */ 41#define VM_RADIX_RED 0x2 /* Red node. (leaf only) */ 42#define VM_RADIX_ANY (VM_RADIX_RED | VM_RADIX_BLACK) 43#define VM_RADIX_EMPTY 0x1 /* Empty hint. (internal only) */ 44#define VM_RADIX_HEIGHT 0xf /* Bits of height in root */ 45#define VM_RADIX_STACK 8 /* Nodes to store on stack. */ 46 47/* Calculates maximum value for a tree of height h. */ 48#define VM_RADIX_MAX(h) \ 49 ((h) == VM_RADIX_LIMIT ? ((vm_pindex_t)-1) : \ 50 (((vm_pindex_t)1 << ((h) * VM_RADIX_WIDTH)) - 1)) 51 52/* 53 * Radix tree root. The height and pointer are set together to permit 54 * coherent lookups while the root is modified. 55 */ 56struct vm_radix { 57 uintptr_t rt_root; /* root + height */ 58}; 59 60#ifdef _KERNEL 61CTASSERT(VM_RADIX_HEIGHT >= VM_RADIX_LIMIT); 62 63struct vm_radix_node { 64 void *rn_child[VM_RADIX_COUNT]; /* Child nodes. */ 65 volatile uint32_t rn_count; /* Valid children. */ 66}; 67 68void vm_radix_init(void); 69 70/* 71 * Functions which only work with black nodes. (object lock) 72 */ 73int vm_radix_insert(struct vm_radix *, vm_pindex_t, void *); 74void vm_radix_shrink(struct vm_radix *); 75 76/* 77 * Functions which work on specified colors. (object, vm_page_queue_free locks) 78 */ 79void *vm_radix_color(struct vm_radix *, vm_pindex_t, int); 80void *vm_radix_lookup(struct vm_radix *, vm_pindex_t, int); 81int vm_radix_lookupn(struct vm_radix *, vm_pindex_t, vm_pindex_t, int, 82 void **, int, vm_pindex_t *); 83void *vm_radix_lookup_le(struct vm_radix *, vm_pindex_t, int); 84void vm_radix_reclaim_allnodes(struct vm_radix *); 85void *vm_radix_remove(struct vm_radix *, vm_pindex_t, int); 86void vm_radix_foreach(struct vm_radix *, vm_pindex_t, vm_pindex_t, int, 87 void (*)(void *)); 88 89/* 90 * Look up any entry at a position greater or equal to index. 91 */ 92static inline void * 93vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index, int color) 94{ 95 void *val; 96 97 if (vm_radix_lookupn(rtree, index, 0, color, &val, 1, &index)) 98 return (val); 99 return (NULL); 100} 101 102static inline void * 103vm_radix_last(struct vm_radix *rtree, int color) 104{ 105 106 return vm_radix_lookup_le(rtree, 0, color); 107} 108 109static inline void * 110vm_radix_first(struct vm_radix *rtree, int color) 111{ 112 113 return vm_radix_lookup_ge(rtree, 0, color); 114} 115 116static inline void * 117vm_radix_next(struct vm_radix *rtree, vm_pindex_t index, int color) 118{ 119 120 if (index == -1) 121 return (NULL); 122 return vm_radix_lookup_ge(rtree, index + 1, color); 123} 124 125static inline void * 126vm_radix_prev(struct vm_radix *rtree, vm_pindex_t index, int color) 127{ 128 129 if (index == 0) 130 return (NULL); 131 return vm_radix_lookup_le(rtree, index - 1, color); 132} 133 134#endif /* _KERNEL */ 135#endif /* !_VM_RADIX_H_ */ 136