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 | |