xref: /illumos-gate/usr/src/uts/common/sys/bitmap.h (revision fb2612809ed5f2cb9109db768e63d61f6659f71b)
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 2017 RackTop Systems.
30  */
31 
32 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
33 /*	  All Rights Reserved	*/
34 
35 
36 #ifndef _SYS_BITMAP_H
37 #define	_SYS_BITMAP_H
38 
39 #ifdef	__cplusplus
40 extern "C" {
41 #endif
42 
43 #include <sys/feature_tests.h>
44 #if defined(__GNUC__) && defined(_ASM_INLINES) && \
45 	(defined(__i386) || defined(__amd64))
46 #include <asm/bitmap.h>
47 #endif
48 
49 /*
50  * Operations on bitmaps of arbitrary size
51  * A bitmap is a vector of 1 or more ulong_t's.
52  * The user of the package is responsible for range checks and keeping
53  * track of sizes.
54  */
55 
56 #ifdef _LP64
57 #define	BT_ULSHIFT	6 /* log base 2 of BT_NBIPUL, to extract word index */
58 #define	BT_ULSHIFT32	5 /* log base 2 of BT_NBIPUL, to extract word index */
59 #else
60 #define	BT_ULSHIFT	5 /* log base 2 of BT_NBIPUL, to extract word index */
61 #endif
62 
63 #define	BT_NBIPUL	(1 << BT_ULSHIFT)	/* n bits per ulong_t */
64 #define	BT_ULMASK	(BT_NBIPUL - 1)		/* to extract bit index */
65 
66 #ifdef _LP64
67 #define	BT_NBIPUL32	(1 << BT_ULSHIFT32)	/* n bits per ulong_t */
68 #define	BT_ULMASK32	(BT_NBIPUL32 - 1)	/* to extract bit index */
69 #define	BT_ULMAXMASK	0xffffffffffffffff	/* used by bt_getlowbit */
70 #else
71 #define	BT_ULMAXMASK	0xffffffff
72 #endif
73 
74 /*
75  * bitmap is a ulong_t *, bitindex an index_t
76  *
77  * The macros BT_WIM and BT_BIW internal; there is no need
78  * for users of this package to use them.
79  */
80 
81 /*
82  * word in map
83  */
84 #define	BT_WIM(bitmap, bitindex) \
85 	((bitmap)[(bitindex) >> BT_ULSHIFT])
86 /*
87  * bit in word
88  */
89 #define	BT_BIW(bitindex) \
90 	(1UL << ((bitindex) & BT_ULMASK))
91 
92 #ifdef _LP64
93 #define	BT_WIM32(bitmap, bitindex) \
94 	((bitmap)[(bitindex) >> BT_ULSHIFT32])
95 
96 #define	BT_BIW32(bitindex) \
97 	(1UL << ((bitindex) & BT_ULMASK32))
98 #endif
99 
100 /*
101  * These are public macros
102  *
103  * BT_BITOUL == n bits to n ulong_t's
104  */
105 #define	BT_BITOUL(nbits) \
106 	(((nbits) + BT_NBIPUL - 1l) / BT_NBIPUL)
107 #define	BT_SIZEOFMAP(nbits) \
108 	(BT_BITOUL(nbits) * sizeof (ulong_t))
109 #define	BT_TEST(bitmap, bitindex) \
110 	((BT_WIM((bitmap), (bitindex)) & BT_BIW(bitindex)) ? 1 : 0)
111 #define	BT_SET(bitmap, bitindex) \
112 	{ BT_WIM((bitmap), (bitindex)) |= BT_BIW(bitindex); }
113 #define	BT_CLEAR(bitmap, bitindex) \
114 	{ BT_WIM((bitmap), (bitindex)) &= ~BT_BIW(bitindex); }
115 
116 #ifdef _LP64
117 #define	BT_BITOUL32(nbits) \
118 	(((nbits) + BT_NBIPUL32 - 1l) / BT_NBIPUL32)
119 #define	BT_SIZEOFMAP32(nbits) \
120 	(BT_BITOUL32(nbits) * sizeof (uint_t))
121 #define	BT_TEST32(bitmap, bitindex) \
122 	((BT_WIM32((bitmap), (bitindex)) & BT_BIW32(bitindex)) ? 1 : 0)
123 #define	BT_SET32(bitmap, bitindex) \
124 	{ BT_WIM32((bitmap), (bitindex)) |= BT_BIW32(bitindex); }
125 #define	BT_CLEAR32(bitmap, bitindex) \
126 	{ BT_WIM32((bitmap), (bitindex)) &= ~BT_BIW32(bitindex); }
127 #endif /* _LP64 */
128 
129 
130 /*
131  * BIT_ONLYONESET is a private macro not designed for bitmaps of
132  * arbitrary size.  u must be an unsigned integer/long.  It returns
133  * true if one and only one bit is set in u.
134  */
135 #define	BIT_ONLYONESET(u) \
136 	((((u) == 0) ? 0 : ((u) & ((u) - 1)) == 0))
137 
138 #if (defined(_KERNEL) || defined(_FAKE_KERNEL)) && !defined(_ASM)
139 #include <sys/atomic.h>
140 
141 /*
142  * return next available bit index from map with specified number of bits
143  */
144 extern index_t	bt_availbit(ulong_t *bitmap, size_t nbits);
145 /*
146  * find the highest order bit that is on, and is within or below
147  * the word specified by wx
148  */
149 extern int	bt_gethighbit(ulong_t *mapp, int wx);
150 extern int	bt_range(ulong_t *bitmap, size_t *pos1, size_t *pos2,
151 			size_t end_pos);
152 /*
153  * Find highest and lowest one bit set.
154  *	Returns bit number + 1 of bit that is set, otherwise returns 0.
155  * Low order bit is 0, high order bit is 31.
156  */
157 extern int	highbit(ulong_t);
158 extern int	highbit64(uint64_t);
159 extern int	lowbit(ulong_t);
160 extern int	bt_getlowbit(ulong_t *bitmap, size_t start, size_t stop);
161 extern void	bt_copy(ulong_t *, ulong_t *, ulong_t);
162 
163 /*
164  * find the parity
165  */
166 extern int	odd_parity(ulong_t);
167 
168 /*
169  * Atomically set/clear bits
170  * Atomic exclusive operations will set "result" to "-1"
171  * if the bit is already set/cleared. "result" will be set
172  * to 0 otherwise.
173  */
174 #define	BT_ATOMIC_SET(bitmap, bitindex) \
175 	{ atomic_or_ulong(&(BT_WIM(bitmap, bitindex)), BT_BIW(bitindex)); }
176 #define	BT_ATOMIC_CLEAR(bitmap, bitindex) \
177 	{ atomic_and_ulong(&(BT_WIM(bitmap, bitindex)), ~BT_BIW(bitindex)); }
178 
179 #define	BT_ATOMIC_SET_EXCL(bitmap, bitindex, result) \
180 	{ result = atomic_set_long_excl(&(BT_WIM(bitmap, bitindex)),	\
181 	    (bitindex) % BT_NBIPUL); }
182 #define	BT_ATOMIC_CLEAR_EXCL(bitmap, bitindex, result) \
183 	{ result = atomic_clear_long_excl(&(BT_WIM(bitmap, bitindex)),	\
184 	    (bitindex) % BT_NBIPUL); }
185 
186 /*
187  * Extracts bits between index h (high, inclusive) and l (low, exclusive) from
188  * u, which must be an unsigned integer.
189  */
190 #define	BITX(u, h, l)	(((u) >> (l)) & ((1LU << ((h) - (l) + 1LU)) - 1LU))
191 
192 #endif	/* (_KERNEL || _FAKE_KERNEL) && !_ASM */
193 
194 #ifdef	__cplusplus
195 }
196 #endif
197 
198 #endif	/* _SYS_BITMAP_H */
199