1 /*- 2 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved. 3 * Redistribution and use in source and binary forms, with or without 4 * modification, are permitted provided that the following conditions 5 * are met: 6 * 1. Redistributions of source code must retain the above copyright 7 * notice, this list of conditions and the following disclaimer. 8 * 2. Redistributions in binary form must reproduce the above copyright 9 * notice, this list of conditions and the following disclaimer in the 10 * documentation and/or other materials provided with the distribution. 11 * 3. Neither the name of the University nor the names of its contributors 12 * may be used to endorse or promote products derived from this software 13 * without specific prior written permission. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 21 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 24 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 /* 29 * Implements bitmap resource lists. 30 * 31 * Usage: 32 * blist = blist_create(blocks, flags) 33 * (void) blist_destroy(blist) 34 * blkno = blist_alloc(blist, count) 35 * (void) blist_free(blist, blkno, count) 36 * nblks = blist_fill(blist, blkno, count) 37 * (void) blist_resize(&blist, count, freeextra, flags) 38 * 39 * 40 * Notes: 41 * on creation, the entire list is marked reserved. You should 42 * first blist_free() the sections you want to make available 43 * for allocation before doing general blist_alloc()/free() 44 * ops. 45 * 46 * SWAPBLK_NONE is returned on failure. This module is typically 47 * capable of managing up to (2^63) blocks per blist, though 48 * the memory utilization would be insane if you actually did 49 * that. Managing something like 512MB worth of 4K blocks 50 * eats around 32 KBytes of memory. 51 * 52 * $FreeBSD$ 53 54 */ 55 56 #ifndef _SYS_BLIST_H_ 57 #define _SYS_BLIST_H_ 58 59 typedef 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 bmu_bitmap MUST be a power of 2 in size. 71 */ 72 73 typedef struct blmeta { 74 union { 75 daddr_t bmu_avail; /* space available under us */ 76 u_daddr_t bmu_bitmap; /* bitmap if we are a leaf */ 77 } u; 78 daddr_t bm_bighint; /* biggest contiguous block hint*/ 79 } blmeta_t; 80 81 typedef struct blist { 82 daddr_t bl_blocks; /* area of coverage */ 83 daddr_t bl_radix; /* coverage radix */ 84 daddr_t bl_skip; /* starting skip */ 85 daddr_t bl_cursor; /* next-fit search starts at */ 86 blmeta_t *bl_root; /* root of radix tree */ 87 } *blist_t; 88 89 #define BLIST_META_RADIX 16 90 #define BLIST_BMAP_RADIX (sizeof(u_daddr_t)*8) 91 92 #define BLIST_MAX_ALLOC BLIST_BMAP_RADIX 93 94 daddr_t blist_alloc(blist_t blist, daddr_t count); 95 daddr_t blist_avail(blist_t blist); 96 blist_t blist_create(daddr_t blocks, int flags); 97 void blist_destroy(blist_t blist); 98 daddr_t blist_fill(blist_t bl, daddr_t blkno, daddr_t count); 99 void blist_free(blist_t blist, daddr_t blkno, daddr_t count); 100 void blist_print(blist_t blist); 101 void blist_resize(blist_t *pblist, daddr_t count, int freenew, int flags); 102 103 #endif /* _SYS_BLIST_H_ */ 104 105