xref: /illumos-gate/usr/src/uts/common/sys/bitmap.h (revision 811599a4)
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 /*
28  * Copyright (c) 2014 by Delphix. All rights reserved.
29  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
30  * Copyright 2017 RackTop Systems.
31  */
32 
33 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
34 /*	  All Rights Reserved	*/
35 
36 
37 #ifndef _SYS_BITMAP_H
38 #define	_SYS_BITMAP_H
39 
40 #ifdef	__cplusplus
41 extern "C" {
42 #endif
43 
44 #include <sys/feature_tests.h>
45 #if defined(__GNUC__) && defined(_ASM_INLINES) && \
46 	(defined(__i386) || defined(__amd64))
47 #include <asm/bitmap.h>
48 #endif
49 
50 /*
51  * Operations on bitmaps of arbitrary size
52  * A bitmap is a vector of 1 or more ulong_t's.
53  * The user of the package is responsible for range checks and keeping
54  * track of sizes.
55  */
56 
57 #ifdef _LP64
58 #define	BT_ULSHIFT	6 /* log base 2 of BT_NBIPUL, to extract word index */
59 #define	BT_ULSHIFT32	5 /* log base 2 of BT_NBIPUL, to extract word index */
60 #else
61 #define	BT_ULSHIFT	5 /* log base 2 of BT_NBIPUL, to extract word index */
62 #endif
63 
64 #define	BT_NBIPUL	(1 << BT_ULSHIFT)	/* n bits per ulong_t */
65 #define	BT_ULMASK	(BT_NBIPUL - 1)		/* to extract bit index */
66 
67 #ifdef _LP64
68 #define	BT_NBIPUL32	(1 << BT_ULSHIFT32)	/* n bits per ulong_t */
69 #define	BT_ULMASK32	(BT_NBIPUL32 - 1)	/* to extract bit index */
70 #define	BT_ULMAXMASK	0xffffffffffffffff	/* used by bt_getlowbit */
71 #else
72 #define	BT_ULMAXMASK	0xffffffff
73 #endif
74 
75 /*
76  * bitmap is a ulong_t *, bitindex an index_t
77  *
78  * The macros BT_WIM and BT_BIW internal; there is no need
79  * for users of this package to use them.
80  */
81 
82 /*
83  * word in map
84  */
85 #define	BT_WIM(bitmap, bitindex) \
86 	((bitmap)[(bitindex) >> BT_ULSHIFT])
87 /*
88  * bit in word
89  */
90 #define	BT_BIW(bitindex) \
91 	(1UL << ((bitindex) & BT_ULMASK))
92 
93 #ifdef _LP64
94 #define	BT_WIM32(bitmap, bitindex) \
95 	((bitmap)[(bitindex) >> BT_ULSHIFT32])
96 
97 #define	BT_BIW32(bitindex) \
98 	(1UL << ((bitindex) & BT_ULMASK32))
99 #endif
100 
101 /*
102  * These are public macros
103  *
104  * BT_BITOUL == n bits to n ulong_t's
105  */
106 #define	BT_BITOUL(nbits) \
107 	(((nbits) + BT_NBIPUL - 1l) / BT_NBIPUL)
108 #define	BT_SIZEOFMAP(nbits) \
109 	(BT_BITOUL(nbits) * sizeof (ulong_t))
110 #define	BT_TEST(bitmap, bitindex) \
111 	((BT_WIM((bitmap), (bitindex)) & BT_BIW(bitindex)) ? 1 : 0)
112 #define	BT_SET(bitmap, bitindex) \
113 	{ BT_WIM((bitmap), (bitindex)) |= BT_BIW(bitindex); }
114 #define	BT_CLEAR(bitmap, bitindex) \
115 	{ BT_WIM((bitmap), (bitindex)) &= ~BT_BIW(bitindex); }
116 
117 #ifdef _LP64
118 #define	BT_BITOUL32(nbits) \
119 	(((nbits) + BT_NBIPUL32 - 1l) / BT_NBIPUL32)
120 #define	BT_SIZEOFMAP32(nbits) \
121 	(BT_BITOUL32(nbits) * sizeof (uint_t))
122 #define	BT_TEST32(bitmap, bitindex) \
123 	((BT_WIM32((bitmap), (bitindex)) & BT_BIW32(bitindex)) ? 1 : 0)
124 #define	BT_SET32(bitmap, bitindex) \
125 	{ BT_WIM32((bitmap), (bitindex)) |= BT_BIW32(bitindex); }
126 #define	BT_CLEAR32(bitmap, bitindex) \
127 	{ BT_WIM32((bitmap), (bitindex)) &= ~BT_BIW32(bitindex); }
128 #endif /* _LP64 */
129 
130 
131 /*
132  * BIT_ONLYONESET is a private macro not designed for bitmaps of
133  * arbitrary size.  u must be an unsigned integer/long.  It returns
134  * true if one and only one bit is set in u.
135  */
136 #define	BIT_ONLYONESET(u) \
137 	((((u) == 0) ? 0 : ((u) & ((u) - 1)) == 0))
138 
139 #if (defined(_KERNEL) || defined(_FAKE_KERNEL)) && !defined(_ASM)
140 #include <sys/atomic.h>
141 
142 /*
143  * return next available bit index from map with specified number of bits
144  */
145 extern index_t	bt_availbit(ulong_t *bitmap, size_t nbits);
146 /*
147  * find the highest order bit that is on, and is within or below
148  * the word specified by wx
149  */
150 extern int	bt_gethighbit(ulong_t *mapp, int wx);
151 extern int	bt_range(ulong_t *bitmap, size_t *pos1, size_t *pos2,
152 			size_t end_pos);
153 /*
154  * Find highest and lowest one bit set.
155  *	Returns bit number + 1 of bit that is set, otherwise returns 0.
156  * Low order bit is 0, high order bit is 31.
157  */
158 extern int	highbit(ulong_t);
159 extern int	highbit64(uint64_t);
160 extern int	lowbit(ulong_t);
161 extern int	bt_getlowbit(ulong_t *bitmap, size_t start, size_t stop);
162 extern void	bt_copy(ulong_t *, ulong_t *, ulong_t);
163 
164 /*
165  * find the parity
166  */
167 extern int	odd_parity(ulong_t);
168 
169 /*
170  * Atomically set/clear bits
171  * Atomic exclusive operations will set "result" to "-1"
172  * if the bit is already set/cleared. "result" will be set
173  * to 0 otherwise.
174  */
175 #define	BT_ATOMIC_SET(bitmap, bitindex) \
176 	{ atomic_or_ulong(&(BT_WIM(bitmap, bitindex)), BT_BIW(bitindex)); }
177 #define	BT_ATOMIC_CLEAR(bitmap, bitindex) \
178 	{ atomic_and_ulong(&(BT_WIM(bitmap, bitindex)), ~BT_BIW(bitindex)); }
179 
180 #define	BT_ATOMIC_SET_EXCL(bitmap, bitindex, result) \
181 	{ result = atomic_set_long_excl(&(BT_WIM(bitmap, bitindex)),	\
182 	    (bitindex) % BT_NBIPUL); }
183 #define	BT_ATOMIC_CLEAR_EXCL(bitmap, bitindex, result) \
184 	{ result = atomic_clear_long_excl(&(BT_WIM(bitmap, bitindex)),	\
185 	    (bitindex) % BT_NBIPUL); }
186 
187 /*
188  * Extracts bits between index h (high, inclusive) and l (low, exclusive) from
189  * u, which must be an unsigned integer.
190  */
191 #define	BITX(u, h, l)	(((u) >> (l)) & ((1LU << ((h) - (l) + 1LU)) - 1LU))
192 
193 #endif	/* (_KERNEL || _FAKE_KERNEL) && !_ASM */
194 
195 #ifdef	__cplusplus
196 }
197 #endif
198 
199 #endif	/* _SYS_BITMAP_H */
200