1 /* $NetBSD: blist.h,v 1.8 2013/12/09 09:35:17 wiz Exp $ */ 2 3 /*- 4 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 18 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 23 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 26 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 27 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * Implements bitmap resource lists. 32 * 33 * Usage: 34 * blist = blist_create(blocks) 35 * (void) blist_destroy(blist) 36 * blkno = blist_alloc(blist, count) 37 * (void) blist_free(blist, blkno, count) 38 * nblks = blist_fill(blist, blkno, count) 39 * (void) blist_resize(&blist, count, freeextra) 40 * 41 * 42 * Notes: 43 * on creation, the entire list is marked reserved. You should 44 * first blist_free() the sections you want to make available 45 * for allocation before doing general blist_alloc()/free() 46 * ops. 47 * 48 * BLIST_NONE is returned on failure. This module is typically 49 * capable of managing up to (2^31) blocks per blist, though 50 * the memory utilization would be insane if you actually did 51 * that. Managing something like 512MB worth of 4K blocks 52 * eats around 32 KBytes of memory. 53 * 54 * $FreeBSD: src/sys/sys/blist.h,v 1.9 2005/01/07 02:29:23 imp Exp $ 55 */ 56 57 #ifndef _SYS_BLIST_H_ 58 #define _SYS_BLIST_H_ 59 60 /* 61 * for space efficiency, sizeof(blist_bitmap_t) should be 62 * greater than or equal to sizeof(blist_blkno_t). 63 */ 64 65 typedef uint32_t blist_bitmap_t; 66 typedef uint32_t blist_blkno_t; 67 68 /* 69 * note: currently use BLIST_NONE as an absolute value rather than 70 * a flag bit. 71 */ 72 73 #define BLIST_NONE ((blist_blkno_t)-1) 74 75 typedef struct blist *blist_t; 76 77 #define BLIST_BMAP_RADIX (sizeof(blist_bitmap_t)*8) 78 #define BLIST_MAX_ALLOC BLIST_BMAP_RADIX 79 80 extern blist_t blist_create(blist_blkno_t blocks); 81 extern void blist_destroy(blist_t blist); 82 extern blist_blkno_t blist_alloc(blist_t blist, blist_blkno_t count); 83 extern void blist_free(blist_t blist, blist_blkno_t blkno, blist_blkno_t count); 84 extern blist_blkno_t blist_fill(blist_t bl, blist_blkno_t blkno, 85 blist_blkno_t count); 86 extern void blist_print(blist_t blist); 87 extern void blist_resize(blist_t *pblist, blist_blkno_t count, int freenew); 88 89 #endif /* _SYS_BLIST_H_ */ 90 91