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 | |