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author | Matthew Dillon <dillon@FreeBSD.org> | 1999-01-21 08:11:06 +0000 |
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committer | Matthew Dillon <dillon@FreeBSD.org> | 1999-01-21 08:11:06 +0000 |
commit | 7090df5aedf992f32acd3e943feef5610de2a3d0 (patch) | |
tree | 9a1c9ec686b6e12c3224878db9257cd7bf602d95 /sys/sys/blist.h | |
parent | eedc343625e28519e717a9867dff20efe5081a12 (diff) | |
download | src-7090df5aedf992f32acd3e943feef5610de2a3d0.tar.gz src-7090df5aedf992f32acd3e943feef5610de2a3d0.zip |
Notes
Diffstat (limited to 'sys/sys/blist.h')
-rw-r--r-- | sys/sys/blist.h | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/sys/sys/blist.h b/sys/sys/blist.h new file mode 100644 index 000000000000..05d82398d1b6 --- /dev/null +++ b/sys/sys/blist.h @@ -0,0 +1,101 @@ +/* + * Copyright (c) 1998 Matthew Dillon. Terms of use and redistribution in all + * forms are covered by the BSD copyright in the file "/usr/src/COPYRIGHT". + * + * Implements bitmap resource lists. + * + * Usage: + * blist = blist_create(blocks) + * (void) blist_destroy(blist) + * blkno = blist_alloc(blist, count) + * (void) blist_free(blist, blkno, count) + * (void) blist_resize(&blist, count, freeextra) + * + * + * Notes: + * on creation, the entire list is marked reserved. You should + * first blist_free() the sections you want to make available + * for allocation before doing general blist_alloc()/free() + * ops. + * + * SWAPBLK_NONE is returned on failure. This module is typically + * capable of managing up to (2^31) blocks per blist, though + * the memory utilization would be insane if you actually did + * that. Managing something like 512MB worth of 4K blocks + * eats around 32 KBytes of memory. + * + * $Id: blist.h,v Exp $ + */ + +#ifndef _SYS_BLIST_H_ +#define _SYS_BLIST_H_ + +#define LOG2(v) (((u_daddr_t)(v) >= 0x80000000U) ? 31 : \ + ((u_daddr_t)(v) >= 0x40000000U) ? 30 : \ + ((u_daddr_t)(v) >= 0x20000000U) ? 29 : \ + ((u_daddr_t)(v) >= 0x10000000U) ? 28 : \ + ((u_daddr_t)(v) >= 0x08000000U) ? 27 : \ + ((u_daddr_t)(v) >= 0x04000000U) ? 26 : \ + ((u_daddr_t)(v) >= 0x02000000U) ? 25 : \ + ((u_daddr_t)(v) >= 0x01000000U) ? 24 : \ + ((u_daddr_t)(v) >= 0x00800000U) ? 23 : \ + ((u_daddr_t)(v) >= 0x00400000U) ? 22 : \ + ((u_daddr_t)(v) >= 0x00200000U) ? 21 : \ + ((u_daddr_t)(v) >= 0x00100000U) ? 20 : \ + ((u_daddr_t)(v) >= 0x00080000U) ? 19 : \ + ((u_daddr_t)(v) >= 0x00040000U) ? 18 : \ + ((u_daddr_t)(v) >= 0x00020000U) ? 17 : \ + ((u_daddr_t)(v) >= 0x00010000U) ? 16 : \ + ((u_daddr_t)(v) >= 0x00008000U) ? 15 : \ + ((u_daddr_t)(v) >= 0x00004000U) ? 14 : \ + ((u_daddr_t)(v) >= 0x00002000U) ? 13 : \ + ((u_daddr_t)(v) >= 0x00001000U) ? 12 : \ + ((u_daddr_t)(v) >= 0x00000800U) ? 11 : \ + ((u_daddr_t)(v) >= 0x00000400U) ? 10 : \ + ((u_daddr_t)(v) >= 0x00000200U) ? 9 : \ + ((u_daddr_t)(v) >= 0x00000100U) ? 8 : \ + ((u_daddr_t)(v) >= 0x00000080U) ? 7 : \ + ((u_daddr_t)(v) >= 0x00000040U) ? 6 : \ + ((u_daddr_t)(v) >= 0x00000020U) ? 5 : \ + ((u_daddr_t)(v) >= 0x00000010U) ? 4 : \ + ((u_daddr_t)(v) >= 0x00000008U) ? 3 : \ + ((u_daddr_t)(v) >= 0x00000004U) ? 2 : \ + ((u_daddr_t)(v) >= 0x00000002U) ? 1 : 0) + +/* + * blmeta and bl_bitmap_t MUST be a power of 2 in size. + */ + +typedef struct blmeta { + union { + daddr_t bmu_avail; /* space available under us */ + u_daddr_t bmu_bitmap; /* bitmap if we are a leaf */ + } u; + daddr_t bm_bighint; /* biggest contiguous block hint*/ +} blmeta_t; + +typedef struct blist { + daddr_t bl_blocks; /* area of coverage */ + daddr_t bl_radix; /* coverage radix */ + daddr_t bl_skip; /* starting skip */ + daddr_t bl_free; /* number of free blocks */ + blmeta_t *bl_root; /* root of radix tree */ + daddr_t bl_rootblks; /* daddr_t blks allocated for tree */ +} *blist_t; + +#define BLIST_META_RADIX 16 +#define BLIST_META_RADIX_SHIFT LOG2(BLIST_META_RADIX) +#define BLIST_BMAP_RADIX (sizeof(u_daddr_t)*8) +#define BLIST_BMAP_RADIX_SHIFT LOG2(BLIST_BMAP_RADIX) + +#define BLIST_MAX_ALLOC BLIST_BMAP_RADIX + +extern blist_t blist_create(daddr_t blocks); +extern void blist_destroy(blist_t blist); +extern daddr_t blist_alloc(blist_t blist, daddr_t count); +extern void blist_free(blist_t blist, daddr_t blkno, daddr_t count); +extern void blist_print(blist_t blist); +extern void blist_resize(blist_t *pblist, daddr_t count, int freenew); + +#endif /* _SYS_BLIST_H_ */ + |