1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 * 3. 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, flags)
35 * (void) blist_destroy(blist)
36 * blkno = blist_alloc(blist, &count, maxcount)
37 * (void) blist_free(blist, blkno, count)
38 * nblks = blist_fill(blist, blkno, count)
39 * (void) blist_resize(&blist, count, freeextra, flags)
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 * SWAPBLK_NONE is returned on failure. This module is typically
49 * capable of managing up to (2^63) 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 */
55
56#ifndef _SYS_BLIST_H_
57#define _SYS_BLIST_H_
58
59typedef uint64_t u_daddr_t; /* unsigned disk address */
60
61/*
62 * note: currently use SWAPBLK_NONE as an absolute value rather then
63 * a flag bit.
64 */
65
66#define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */
67#define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */
68
69/*
70 * Both blmeta and bm_bitmap MUST be a power of 2 in size.
71 */
72
73typedef struct blmeta {
74 u_daddr_t bm_bitmap; /* marking unfilled block sets */
75 daddr_t bm_bighint; /* biggest contiguous block hint*/
76} blmeta_t;
77
78typedef struct blist {
79 daddr_t bl_blocks; /* area of coverage */
80 daddr_t bl_avail; /* # available blocks */
81 u_daddr_t bl_radix; /* coverage radix */
82 daddr_t bl_cursor; /* next-fit search starts at */
83 blmeta_t bl_root[1]; /* root of radix tree */
84} *blist_t;
85
86#define BLIST_RADIX (sizeof(u_daddr_t) * 8)
87
88#define BLIST_MAX_ALLOC BLIST_RADIX
89
90struct sbuf;
91
92daddr_t blist_alloc(blist_t blist, int *count, int maxcount);
93daddr_t blist_avail(blist_t blist);
94blist_t blist_create(daddr_t blocks, int flags);
95void blist_destroy(blist_t blist);
96daddr_t blist_fill(blist_t bl, daddr_t blkno, daddr_t count);
97void blist_free(blist_t blist, daddr_t blkno, daddr_t count);
98void blist_print(blist_t blist);
99void blist_resize(blist_t *pblist, daddr_t count, int freenew, int flags);
100void blist_stats(blist_t blist, struct sbuf *s);
101
102#endif /* _SYS_BLIST_H_ */