1 /* 2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * Implements bitmap resource lists. 35 * 36 * Usage: 37 * blist = blist_create(blocks) 38 * (void) blist_destroy(blist) 39 * blkno = blist_alloc(blist, count) 40 * (void) blist_free(blist, blkno, count) 41 * (void) blist_resize(&blist, count, freeextra) 42 * 43 * 44 * Notes: 45 * on creation, the entire list is marked reserved. You should 46 * first blist_free() the sections you want to make available 47 * for allocation before doing general blist_alloc()/free() 48 * ops. 49 * 50 * SWAPBLK_NONE is returned on failure. This module is typically 51 * capable of managing up to (2^31) blocks per blist, though 52 * the memory utilization would be insane if you actually did 53 * that. Managing something like 512MB worth of 4K blocks 54 * eats around 32 KBytes of memory. 55 * 56 * $FreeBSD: src/sys/sys/blist.h,v 1.2.2.1 2003/01/12 09:23:12 dillon Exp $ 57 * $DragonFly: src/sys/sys/blist.h,v 1.6 2006/05/20 02:42:13 dillon Exp $ 58 */ 59 60 #ifndef _SYS_BLIST_H_ 61 #define _SYS_BLIST_H_ 62 63 #ifndef _SYS_TYPES_H_ 64 #include <sys/types.h> 65 #endif 66 67 /* 68 * blmeta and bl_bitmap_t MUST be a power of 2 in size. 69 */ 70 71 typedef struct blmeta { 72 union { 73 daddr_t bmu_avail; /* space available under us */ 74 u_daddr_t bmu_bitmap; /* bitmap if we are a leaf */ 75 } u; 76 daddr_t bm_bighint; /* biggest contiguous block hint*/ 77 } blmeta_t; 78 79 typedef struct blist { 80 daddr_t bl_blocks; /* area of coverage */ 81 daddr_t bl_radix; /* coverage radix */ 82 daddr_t bl_skip; /* starting skip */ 83 daddr_t bl_free; /* number of free blocks */ 84 blmeta_t *bl_root; /* root of radix tree */ 85 daddr_t bl_rootblks; /* daddr_t blks allocated for tree */ 86 } *blist_t; 87 88 #define BLIST_META_RADIX 16 89 #define BLIST_BMAP_RADIX (sizeof(u_daddr_t)*8) 90 91 #define BLIST_MAX_ALLOC BLIST_BMAP_RADIX 92 93 extern blist_t blist_create(daddr_t blocks); 94 extern void blist_destroy(blist_t blist); 95 extern daddr_t blist_alloc(blist_t blist, daddr_t count); 96 extern void blist_free(blist_t blist, daddr_t blkno, daddr_t count); 97 extern void blist_print(blist_t blist); 98 extern void blist_resize(blist_t *pblist, daddr_t count, int freenew); 99 100 #endif /* _SYS_BLIST_H_ */ 101