1 /* 2 * Copyright (c) 1998 Matthew Dillon. Terms of use and redistribution in all 3 * forms are covered by the BSD copyright in the file "/usr/src/COPYRIGHT". 4 * 5 * Implements bitmap resource lists. 6 * 7 * Usage: 8 * blist = blist_create(blocks) 9 * (void) blist_destroy(blist) 10 * blkno = blist_alloc(blist, count) 11 * (void) blist_free(blist, blkno, count) 12 * (void) blist_resize(&blist, count, freeextra) 13 * 14 * 15 * Notes: 16 * on creation, the entire list is marked reserved. You should 17 * first blist_free() the sections you want to make available 18 * for allocation before doing general blist_alloc()/free() 19 * ops. 20 * 21 * SWAPBLK_NONE is returned on failure. This module is typically 22 * capable of managing up to (2^31) blocks per blist, though 23 * the memory utilization would be insane if you actually did 24 * that. Managing something like 512MB worth of 4K blocks 25 * eats around 32 KBytes of memory. 26 * 27 * $FreeBSD: src/sys/sys/blist.h,v 1.2 1999/08/28 00:51:33 peter Exp $ 28 */ 29 30 #ifndef _SYS_BLIST_H_ 31 #define _SYS_BLIST_H_ 32 33 #define LOG2(v) (((u_daddr_t)(v) >= 0x80000000U) ? 31 : \ 34 ((u_daddr_t)(v) >= 0x40000000U) ? 30 : \ 35 ((u_daddr_t)(v) >= 0x20000000U) ? 29 : \ 36 ((u_daddr_t)(v) >= 0x10000000U) ? 28 : \ 37 ((u_daddr_t)(v) >= 0x08000000U) ? 27 : \ 38 ((u_daddr_t)(v) >= 0x04000000U) ? 26 : \ 39 ((u_daddr_t)(v) >= 0x02000000U) ? 25 : \ 40 ((u_daddr_t)(v) >= 0x01000000U) ? 24 : \ 41 ((u_daddr_t)(v) >= 0x00800000U) ? 23 : \ 42 ((u_daddr_t)(v) >= 0x00400000U) ? 22 : \ 43 ((u_daddr_t)(v) >= 0x00200000U) ? 21 : \ 44 ((u_daddr_t)(v) >= 0x00100000U) ? 20 : \ 45 ((u_daddr_t)(v) >= 0x00080000U) ? 19 : \ 46 ((u_daddr_t)(v) >= 0x00040000U) ? 18 : \ 47 ((u_daddr_t)(v) >= 0x00020000U) ? 17 : \ 48 ((u_daddr_t)(v) >= 0x00010000U) ? 16 : \ 49 ((u_daddr_t)(v) >= 0x00008000U) ? 15 : \ 50 ((u_daddr_t)(v) >= 0x00004000U) ? 14 : \ 51 ((u_daddr_t)(v) >= 0x00002000U) ? 13 : \ 52 ((u_daddr_t)(v) >= 0x00001000U) ? 12 : \ 53 ((u_daddr_t)(v) >= 0x00000800U) ? 11 : \ 54 ((u_daddr_t)(v) >= 0x00000400U) ? 10 : \ 55 ((u_daddr_t)(v) >= 0x00000200U) ? 9 : \ 56 ((u_daddr_t)(v) >= 0x00000100U) ? 8 : \ 57 ((u_daddr_t)(v) >= 0x00000080U) ? 7 : \ 58 ((u_daddr_t)(v) >= 0x00000040U) ? 6 : \ 59 ((u_daddr_t)(v) >= 0x00000020U) ? 5 : \ 60 ((u_daddr_t)(v) >= 0x00000010U) ? 4 : \ 61 ((u_daddr_t)(v) >= 0x00000008U) ? 3 : \ 62 ((u_daddr_t)(v) >= 0x00000004U) ? 2 : \ 63 ((u_daddr_t)(v) >= 0x00000002U) ? 1 : 0) 64 65 /* 66 * blmeta and bl_bitmap_t MUST be a power of 2 in size. 67 */ 68 69 typedef struct blmeta { 70 union { 71 daddr_t bmu_avail; /* space available under us */ 72 u_daddr_t bmu_bitmap; /* bitmap if we are a leaf */ 73 } u; 74 daddr_t bm_bighint; /* biggest contiguous block hint*/ 75 } blmeta_t; 76 77 typedef struct blist { 78 daddr_t bl_blocks; /* area of coverage */ 79 daddr_t bl_radix; /* coverage radix */ 80 daddr_t bl_skip; /* starting skip */ 81 daddr_t bl_free; /* number of free blocks */ 82 blmeta_t *bl_root; /* root of radix tree */ 83 daddr_t bl_rootblks; /* daddr_t blks allocated for tree */ 84 } *blist_t; 85 86 #define BLIST_META_RADIX 16 87 #define BLIST_META_RADIX_SHIFT LOG2(BLIST_META_RADIX) 88 #define BLIST_BMAP_RADIX (sizeof(u_daddr_t)*8) 89 #define BLIST_BMAP_RADIX_SHIFT LOG2(BLIST_BMAP_RADIX) 90 91 #define BLIST_MAX_ALLOC BLIST_BMAP_RADIX 92 93 #if defined(__APPLE__) 94 #define SWAPBLK_NONE ((daddr_t)-1) 95 #endif /* __APPLE__ */ 96 97 extern blist_t blist_create(daddr_t blocks); 98 extern void blist_destroy(blist_t blist); 99 extern daddr_t blist_alloc(blist_t blist, daddr_t count); 100 extern void blist_free(blist_t blist, daddr_t blkno, daddr_t count); 101 extern void blist_print(blist_t blist); 102 extern void blist_resize(blist_t *pblist, daddr_t count, int freenew); 103 104 #endif /* _SYS_BLIST_H_ */ 105