xref: /illumos-gate/usr/src/uts/common/sys/bitmap.h (revision bea83d026ee1bd1b2a2419e1d0232f107a5d7d9b)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 
31 #ifndef _SYS_BITMAP_H
32 #define	_SYS_BITMAP_H
33 
34 #pragma ident	"%Z%%M%	%I%	%E% SMI"
35 
36 #ifdef	__cplusplus
37 extern "C" {
38 #endif
39 
40 #include <sys/feature_tests.h>
41 #if defined(__GNUC__) && defined(_ASM_INLINES) && \
42 	(defined(__i386) || defined(__amd64))
43 #include <asm/bitmap.h>
44 #endif
45 
46 /*
47  * Operations on bitmaps of arbitrary size
48  * A bitmap is a vector of 1 or more ulong_t's.
49  * The user of the package is responsible for range checks and keeping
50  * track of sizes.
51  */
52 
53 #ifdef _LP64
54 #define	BT_ULSHIFT	6 /* log base 2 of BT_NBIPUL, to extract word index */
55 #define	BT_ULSHIFT32	5 /* log base 2 of BT_NBIPUL, to extract word index */
56 #else
57 #define	BT_ULSHIFT	5 /* log base 2 of BT_NBIPUL, to extract word index */
58 #endif
59 
60 #define	BT_NBIPUL	(1 << BT_ULSHIFT)	/* n bits per ulong_t */
61 #define	BT_ULMASK	(BT_NBIPUL - 1)		/* to extract bit index */
62 
63 #ifdef _LP64
64 #define	BT_NBIPUL32	(1 << BT_ULSHIFT32)	/* n bits per ulong_t */
65 #define	BT_ULMASK32	(BT_NBIPUL32 - 1)	/* to extract bit index */
66 #define	BT_ULMAXMASK	0xffffffffffffffff	/* used by bt_getlowbit */
67 #else
68 #define	BT_ULMAXMASK	0xffffffff
69 #endif
70 
71 /*
72  * bitmap is a ulong_t *, bitindex an index_t
73  *
74  * The macros BT_WIM and BT_BIW internal; there is no need
75  * for users of this package to use them.
76  */
77 
78 /*
79  * word in map
80  */
81 #define	BT_WIM(bitmap, bitindex) \
82 	((bitmap)[(bitindex) >> BT_ULSHIFT])
83 /*
84  * bit in word
85  */
86 #define	BT_BIW(bitindex) \
87 	(1UL << ((bitindex) & BT_ULMASK))
88 
89 #ifdef _LP64
90 #define	BT_WIM32(bitmap, bitindex) \
91 	((bitmap)[(bitindex) >> BT_ULSHIFT32])
92 
93 #define	BT_BIW32(bitindex) \
94 	(1UL << ((bitindex) & BT_ULMASK32))
95 #endif
96 
97 /*
98  * These are public macros
99  *
100  * BT_BITOUL == n bits to n ulong_t's
101  */
102 #define	BT_BITOUL(nbits) \
103 	(((nbits) + BT_NBIPUL - 1l) / BT_NBIPUL)
104 #define	BT_SIZEOFMAP(nbits) \
105 	(BT_BITOUL(nbits) * sizeof (ulong_t))
106 #define	BT_TEST(bitmap, bitindex) \
107 	((BT_WIM((bitmap), (bitindex)) & BT_BIW(bitindex)) ? 1 : 0)
108 #define	BT_SET(bitmap, bitindex) \
109 	{ BT_WIM((bitmap), (bitindex)) |= BT_BIW(bitindex); }
110 #define	BT_CLEAR(bitmap, bitindex) \
111 	{ BT_WIM((bitmap), (bitindex)) &= ~BT_BIW(bitindex); }
112 
113 #ifdef _LP64
114 #define	BT_BITOUL32(nbits) \
115 	(((nbits) + BT_NBIPUL32 - 1l) / BT_NBIPUL32)
116 #define	BT_SIZEOFMAP32(nbits) \
117 	(BT_BITOUL32(nbits) * sizeof (uint_t))
118 #define	BT_TEST32(bitmap, bitindex) \
119 	((BT_WIM32((bitmap), (bitindex)) & BT_BIW32(bitindex)) ? 1 : 0)
120 #define	BT_SET32(bitmap, bitindex) \
121 	{ BT_WIM32((bitmap), (bitindex)) |= BT_BIW32(bitindex); }
122 #define	BT_CLEAR32(bitmap, bitindex) \
123 	{ BT_WIM32((bitmap), (bitindex)) &= ~BT_BIW32(bitindex); }
124 #endif /* _LP64 */
125 
126 
127 /*
128  * BIT_ONLYONESET is a private macro not designed for bitmaps of
129  * arbitrary size.  u must be an unsigned integer/long.  It returns
130  * true if one and only one bit is set in u.
131  */
132 #define	BIT_ONLYONESET(u) \
133 	((((u) == 0) ? 0 : ((u) & ((u) - 1)) == 0))
134 
135 #if defined(_KERNEL) && !defined(_ASM)
136 #include <sys/atomic.h>
137 
138 /*
139  * return next available bit index from map with specified number of bits
140  */
141 extern index_t	bt_availbit(ulong_t *bitmap, size_t nbits);
142 /*
143  * find the highest order bit that is on, and is within or below
144  * the word specified by wx
145  */
146 extern int	bt_gethighbit(ulong_t *mapp, int wx);
147 extern int	bt_range(ulong_t *bitmap, size_t *pos1, size_t *pos2,
148 			size_t end_pos);
149 /*
150  * Find highest and lowest one bit set.
151  *	Returns bit number + 1 of bit that is set, otherwise returns 0.
152  * Low order bit is 0, high order bit is 31.
153  */
154 extern int	highbit(ulong_t);
155 extern int	lowbit(ulong_t);
156 extern int	bt_getlowbit(ulong_t *bitmap, size_t start, size_t stop);
157 extern void	bt_copy(ulong_t *, ulong_t *, ulong_t);
158 
159 /*
160  * find the parity
161  */
162 extern int	odd_parity(ulong_t);
163 
164 /*
165  * Atomically set/clear bits
166  * Atomic exclusive operations will set "result" to "-1"
167  * if the bit is already set/cleared. "result" will be set
168  * to 0 otherwise.
169  */
170 #define	BT_ATOMIC_SET(bitmap, bitindex) \
171 	{ atomic_or_long(&(BT_WIM(bitmap, bitindex)), BT_BIW(bitindex)); }
172 #define	BT_ATOMIC_CLEAR(bitmap, bitindex) \
173 	{ atomic_and_long(&(BT_WIM(bitmap, bitindex)), ~BT_BIW(bitindex)); }
174 
175 #define	BT_ATOMIC_SET_EXCL(bitmap, bitindex, result) \
176 	{ result = atomic_set_long_excl(&(BT_WIM(bitmap, bitindex)),	\
177 	    (bitindex) % BT_NBIPUL); }
178 #define	BT_ATOMIC_CLEAR_EXCL(bitmap, bitindex, result) \
179 	{ result = atomic_clear_long_excl(&(BT_WIM(bitmap, bitindex)),	\
180 	    (bitindex) % BT_NBIPUL); }
181 
182 /*
183  * Extracts bits between index h (high, inclusive) and l (low, exclusive) from
184  * u, which must be an unsigned integer.
185  */
186 #define	BITX(u, h, l)	(((u) >> (l)) & ((1LU << ((h) - (l) + 1LU)) - 1LU))
187 
188 #endif	/* _KERNEL && !_ASM */
189 
190 #ifdef	__cplusplus
191 }
192 #endif
193 
194 #endif	/* _SYS_BITMAP_H */
195