| 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 | |