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 * $FreeBSD$ 55 56 */ 57 58 #ifndef _SYS_BLIST_H_ 59 #define _SYS_BLIST_H_ 60 61 typedef uint64_t u_daddr_t; /* unsigned disk address */ 62 63 /* 64 * note: currently use SWAPBLK_NONE as an absolute value rather then 65 * a flag bit. 66 */ 67 68 #define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */ 69 #define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */ 70 71 /* 72 * Both blmeta and bm_bitmap MUST be a power of 2 in size. 73 */ 74 75 typedef struct blmeta { 76 u_daddr_t bm_bitmap; /* marking unfilled block sets */ 77 daddr_t bm_bighint; /* biggest contiguous block hint*/ 78 } blmeta_t; 79 80 typedef struct blist { 81 daddr_t bl_blocks; /* area of coverage */ 82 daddr_t bl_avail; /* # available blocks */ 83 u_daddr_t bl_radix; /* coverage radix */ 84 daddr_t bl_cursor; /* next-fit search starts at */ 85 blmeta_t bl_root[1]; /* root of radix tree */ 86 } *blist_t; 87 88 #define BLIST_BMAP_RADIX (sizeof(u_daddr_t)*8) 89 #define BLIST_META_RADIX BLIST_BMAP_RADIX 90 91 #define BLIST_MAX_ALLOC BLIST_BMAP_RADIX 92 93 struct sbuf; 94 95 daddr_t blist_alloc(blist_t blist, int *count, int maxcount); 96 daddr_t blist_avail(blist_t blist); 97 blist_t blist_create(daddr_t blocks, int flags); 98 void blist_destroy(blist_t blist); 99 daddr_t blist_fill(blist_t bl, daddr_t blkno, daddr_t count); 100 void blist_free(blist_t blist, daddr_t blkno, daddr_t count); 101 void blist_print(blist_t blist); 102 void blist_resize(blist_t *pblist, daddr_t count, int freenew, int flags); 103 void blist_stats(blist_t blist, struct sbuf *s); 104 105 #endif /* _SYS_BLIST_H_ */ 106 107