1 /*
2 * Copyright (c) 2008 Travis Geiselbrecht
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files
6 * (the "Software"), to deal in the Software without restriction,
7 * including without limitation the rights to use, copy, modify, merge,
8 * publish, distribute, sublicense, and/or sell copies of the Software,
9 * and to permit persons to whom the Software is furnished to do so,
10 * subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23 #ifndef __BITS_H
24 #define __BITS_H
25
26 #include <compiler.h>
27 #include <arch/ops.h>
28
29 __BEGIN_CDECLS;
30
31 #define clz(x) __builtin_clz(x)
32 #define ctz(x) __builtin_ctz(x)
33
34 #define BIT(x, bit) ((x) & (1UL << (bit)))
35 #define BIT_SHIFT(x, bit) (((x) >> (bit)) & 1)
36 #define BITS(x, high, low) ((x) & (((1UL<<((high)+1))-1) & ~((1UL<<(low))-1)))
37 #define BITS_SHIFT(x, high, low) (((x) >> (low)) & ((1UL<<((high)-(low)+1))-1))
38 #define BIT_SET(x, bit) (((x) & (1UL << (bit))) ? 1 : 0)
39
40 #define BITMAP_BITS_PER_WORD (sizeof(unsigned long) * 8)
41 #define BITMAP_NUM_WORDS(x) (((x) + BITMAP_BITS_PER_WORD - 1) / BITMAP_BITS_PER_WORD)
42 #define BITMAP_WORD(x) ((x) / BITMAP_BITS_PER_WORD)
43 #define BITMAP_BIT_IN_WORD(x) ((x) & (BITMAP_BITS_PER_WORD - 1))
44
45 #define BITMAP_BITS_PER_INT (sizeof(unsigned int) * 8)
46 #define BITMAP_BIT_IN_INT(x) ((x) & (BITMAP_BITS_PER_INT - 1))
47 #define BITMAP_INT(x) ((x) / BITMAP_BITS_PER_INT)
48
49 #define BIT_MASK(x) (((x) >= sizeof(unsigned long) * 8) ? (0UL-1) : ((1UL << (x)) - 1))
50
bitmap_set(unsigned long * bitmap,int bit)51 static inline int bitmap_set(unsigned long *bitmap, int bit)
52 {
53 unsigned long mask = 1UL << BITMAP_BIT_IN_INT(bit);
54 return atomic_or(&((int *)bitmap)[BITMAP_INT(bit)], (int)mask) & (int)mask ? 1 : 0;
55 }
56
bitmap_clear(unsigned long * bitmap,int bit)57 static inline int bitmap_clear(unsigned long *bitmap, int bit)
58 {
59 unsigned long mask = 1UL << BITMAP_BIT_IN_INT(bit);
60
61 return atomic_and(&((int *)bitmap)[BITMAP_INT(bit)], (int)~mask) & (int)mask ? 1:0;
62 }
63
bitmap_test(unsigned long * bitmap,int bit)64 static inline int bitmap_test(unsigned long *bitmap, int bit)
65 {
66 return BIT_SET(bitmap[BITMAP_WORD(bit)], BITMAP_BIT_IN_WORD(bit));
67 }
68
69 /* find first zero bit starting from LSB */
_ffz(unsigned long x)70 static inline unsigned long _ffz(unsigned long x)
71 {
72 return __builtin_ffsl((long)~x) - 1;
73 }
74
bitmap_ffz(unsigned long * bitmap,int numbits)75 static inline int bitmap_ffz(unsigned long *bitmap, int numbits)
76 {
77 uint i;
78 int bit;
79
80 for (i = 0; i < BITMAP_NUM_WORDS(numbits); i++) {
81 if (bitmap[i] == ~0UL)
82 continue;
83 bit = i * BITMAP_BITS_PER_WORD + _ffz(bitmap[i]);
84 if (bit < numbits)
85 return bit;
86 return -1;
87 }
88 return -1;
89 }
90
91 __END_CDECLS;
92
93 #endif
94