1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
37 */
38
39 #include <sys/cdefs.h>
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43
44 static __inline int
hash_mflags(int flags)45 hash_mflags(int flags)
46 {
47
48 return ((flags & HASH_NOWAIT) ? M_NOWAIT : M_WAITOK);
49 }
50
51 /*
52 * General routine to allocate a hash table with control of memory flags.
53 */
54 void *
hashinit_flags(int elements,struct malloc_type * type,u_long * hashmask,int flags)55 hashinit_flags(int elements, struct malloc_type *type, u_long *hashmask,
56 int flags)
57 {
58 long hashsize, i;
59 LIST_HEAD(generic, generic) *hashtbl;
60
61 KASSERT(elements > 0, ("%s: bad elements", __func__));
62 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */
63 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT),
64 ("Bad flags (0x%x) passed to hashinit_flags", flags));
65
66 for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
67 continue;
68 hashsize >>= 1;
69
70 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type,
71 hash_mflags(flags));
72 if (hashtbl != NULL) {
73 for (i = 0; i < hashsize; i++)
74 LIST_INIT(&hashtbl[i]);
75 *hashmask = hashsize - 1;
76 }
77 return (hashtbl);
78 }
79
80 /*
81 * Allocate and initialize a hash table with default flag: may sleep.
82 */
83 void *
hashinit(int elements,struct malloc_type * type,u_long * hashmask)84 hashinit(int elements, struct malloc_type *type, u_long *hashmask)
85 {
86
87 return (hashinit_flags(elements, type, hashmask, HASH_WAITOK));
88 }
89
90 void
hashdestroy(void * vhashtbl,struct malloc_type * type,u_long hashmask)91 hashdestroy(void *vhashtbl, struct malloc_type *type, u_long hashmask)
92 {
93 LIST_HEAD(generic, generic) *hashtbl, *hp;
94
95 hashtbl = vhashtbl;
96 for (hp = hashtbl; hp <= &hashtbl[hashmask]; hp++)
97 KASSERT(LIST_EMPTY(hp), ("%s: hashtbl %p not empty "
98 "(malloc type %s)", __func__, hashtbl, type->ks_shortdesc));
99 free(hashtbl, type);
100 }
101
102 static const int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531,
103 2039, 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143,
104 6653, 7159, 7673, 8191, 12281, 16381, 24571, 32749 };
105 #define NPRIMES nitems(primes)
106
107 /*
108 * General routine to allocate a prime number sized hash table with control of
109 * memory flags.
110 */
111 void *
phashinit_flags(int elements,struct malloc_type * type,u_long * nentries,int flags)112 phashinit_flags(int elements, struct malloc_type *type, u_long *nentries, int flags)
113 {
114 long hashsize, i;
115 LIST_HEAD(generic, generic) *hashtbl;
116
117 KASSERT(elements > 0, ("%s: bad elements", __func__));
118 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */
119 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT),
120 ("Bad flags (0x%x) passed to phashinit_flags", flags));
121
122 for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
123 i++;
124 if (i == NPRIMES)
125 break;
126 hashsize = primes[i];
127 }
128 hashsize = primes[i - 1];
129
130 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type,
131 hash_mflags(flags));
132 if (hashtbl == NULL)
133 return (NULL);
134
135 for (i = 0; i < hashsize; i++)
136 LIST_INIT(&hashtbl[i]);
137 *nentries = hashsize;
138 return (hashtbl);
139 }
140
141 /*
142 * Allocate and initialize a prime number sized hash table with default flag:
143 * may sleep.
144 */
145 void *
phashinit(int elements,struct malloc_type * type,u_long * nentries)146 phashinit(int elements, struct malloc_type *type, u_long *nentries)
147 {
148
149 return (phashinit_flags(elements, type, nentries, HASH_WAITOK));
150 }
151