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
65typedef uint32_t blist_bitmap_t;
66typedef 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
75typedef struct blist *blist_t;
76
77#define BLIST_BMAP_RADIX (sizeof(blist_bitmap_t)*8)
78#define BLIST_MAX_ALLOC BLIST_BMAP_RADIX
79
80extern blist_t blist_create(blist_blkno_t blocks);
81extern void blist_destroy(blist_t blist);
82extern blist_blkno_t blist_alloc(blist_t blist, blist_blkno_t count);
83extern void blist_free(blist_t blist, blist_blkno_t blkno, blist_blkno_t count);
84extern blist_blkno_t blist_fill(blist_t bl, blist_blkno_t blkno,
85 blist_blkno_t count);
86extern void blist_print(blist_t blist);
87extern void blist_resize(blist_t *pblist, blist_blkno_t count, int freenew);
88
89#endif /* _SYS_BLIST_H_ */
90
91