1 /*- 2 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 3 * Redistribution and use in source and binary forms, with or without 4 * modification, are permitted provided that the following conditions 5 * are met: 6 * 1. Redistributions of source code must retain the above copyright 7 * notice, this list of conditions and the following disclaimer. 8 * 2. Redistributions in binary form must reproduce the above copyright 9 * notice, this list of conditions and the following disclaimer in the 10 * documentation and/or other materials provided with the distribution. 11 * 4. Neither the name of the University nor the names of its contributors 12 * may be used to endorse or promote products derived from this software 13 * without specific prior written permission. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 21 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 24 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 /* 29 * The radix bitmap structure is ported from FreeBSD and is only used 30 * in swap system at the time. 31 */ 32 33 34 #ifndef _KERNEL_UTIL_RADIX_BITMAP_H 35 #define _KERNEL_UTIL_RADIX_BITMAP_H 36 37 38 #include <SupportDefs.h> 39 40 41 typedef uint32 swap_addr_t; 42 typedef uint32 bitmap_t; 43 44 typedef struct radix_node { 45 union { 46 bitmap_t bitmap; // bitmap for the slots if we are a leaf 47 int32 available; // available slots under us if we are not a leaf 48 } u; 49 int32 big_hint; // the biggest continuous slots under us 50 } radix_node; 51 52 // Bitmap which uses radix tree for hinting. 53 // The radix tree is stored in an array. 54 typedef struct radix_bitmap { 55 swap_addr_t free_slots; // # of free slots 56 swap_addr_t radix; // coverage radix 57 swap_addr_t skip; // starting skip 58 radix_node *root; // root of radix tree, actually it is an array 59 swap_addr_t root_size; // size of the array(# of nodes in the tree) 60 } radix_bitmap; 61 62 63 #define BITMAP_RADIX (sizeof(swap_addr_t) * 8) 64 #define NODE_RADIX 16 65 66 #define SWAP_SLOT_NONE ((swap_addr_t)-1) 67 68 69 extern radix_bitmap *radix_bitmap_create(uint32 slots); 70 extern swap_addr_t radix_bitmap_alloc(radix_bitmap *bmp, uint32 count); 71 extern void radix_bitmap_dealloc(radix_bitmap *bmp, swap_addr_t slotIndex, 72 uint32 count); 73 extern void radix_bitmap_destroy(radix_bitmap *bmp); 74 75 #endif // _KERNEL_UTIL_RADIX_BITMAP_H 76 77