source: mainline/kernel/generic/include/adt/bitmap.h@ c5396c1

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since c5396c1 was c5396c1, checked in by Martin Decky <martin@…>, 12 years ago

abandon the 2nd level bitmap
according to observations it is very rare to have allocation requests for more than 8 frames, therefore the conservative update of the 2nd level bitmap can hardly provide any benefits
the natural blocking of the bitmap (by bytes) should provide a reasonable performance

  • Property mode set to 100644
File size: 2.6 KB
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1/*
2 * Copyright (c) 2006 Jakub Jermar
3 * All rights reserved.
4 *
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 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup genericadt
30 * @{
31 */
32/** @file
33 */
34
35#ifndef KERN_BITMAP_H_
36#define KERN_BITMAP_H_
37
38#include <typedefs.h>
39
40#define BITMAP_ELEMENT 8
41#define BITMAP_REMAINER 7
42
43typedef struct {
44 size_t elements;
45 uint8_t *bits;
46} bitmap_t;
47
48static inline void bitmap_set(bitmap_t *bitmap, size_t element,
49 unsigned int value)
50{
51 if (element >= bitmap->elements)
52 return;
53
54 size_t byte = element / BITMAP_ELEMENT;
55 uint8_t mask = 1 << (element & BITMAP_REMAINER);
56
57 if (value) {
58 bitmap->bits[byte] |= mask;
59 } else {
60 bitmap->bits[byte] &= ~mask;
61 }
62}
63
64static inline unsigned int bitmap_get(bitmap_t *bitmap, size_t element)
65{
66 if (element >= bitmap->elements)
67 return 0;
68
69 size_t byte = element / BITMAP_ELEMENT;
70 uint8_t mask = 1 << (element & BITMAP_REMAINER);
71
72 return !!((bitmap->bits)[byte] & mask);
73}
74
75extern size_t bitmap_size(size_t);
76extern void bitmap_initialize(bitmap_t *, size_t, void *);
77
78extern void bitmap_set_range(bitmap_t *, size_t, size_t);
79extern void bitmap_clear_range(bitmap_t *, size_t, size_t);
80
81extern int bitmap_allocate_range(bitmap_t *, size_t, size_t, size_t, size_t *);
82extern void bitmap_copy(bitmap_t *, bitmap_t *, size_t);
83
84#endif
85
86/** @}
87 */
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