1/*-
2 * Copyright (c) 1982, 1986, 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *	@(#)kern_subr.c	8.3 (Berkeley) 1/21/94
35 */
36
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD$");
39
40#include <sys/param.h>
41#include <sys/systm.h>
42#include <sys/malloc.h>
43
44static __inline int
45hash_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 */
54void *
55hashinit_flags(int elements, struct malloc_type *type, u_long *hashmask,
56    int flags)
57{
58	long hashsize;
59	LIST_HEAD(generic, generic) *hashtbl;
60	int i;
61
62	KASSERT(elements > 0, ("%s: bad elements", __func__));
63	/* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */
64	KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT),
65	    ("Bad flags (0x%x) passed to hashinit_flags", flags));
66
67	for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
68		continue;
69	hashsize >>= 1;
70
71	hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type,
72	    hash_mflags(flags));
73	if (hashtbl != NULL) {
74		for (i = 0; i < hashsize; i++)
75			LIST_INIT(&hashtbl[i]);
76		*hashmask = hashsize - 1;
77	}
78	return (hashtbl);
79}
80
81/*
82 * Allocate and initialize a hash table with default flag: may sleep.
83 */
84void *
85hashinit(int elements, struct malloc_type *type, u_long *hashmask)
86{
87
88	return (hashinit_flags(elements, type, hashmask, HASH_WAITOK));
89}
90
91void
92hashdestroy(void *vhashtbl, struct malloc_type *type, u_long hashmask)
93{
94	LIST_HEAD(generic, generic) *hashtbl, *hp;
95
96	hashtbl = vhashtbl;
97	for (hp = hashtbl; hp <= &hashtbl[hashmask]; hp++)
98		KASSERT(LIST_EMPTY(hp), ("%s: hashtbl %p not empty "
99		    "(malloc type %s)", __func__, hashtbl, type->ks_shortdesc));
100	free(hashtbl, type);
101}
102
103static const int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531,
104			2039, 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143,
105			6653, 7159, 7673, 8191, 12281, 16381, 24571, 32749 };
106#define	NPRIMES nitems(primes)
107
108/*
109 * General routine to allocate a prime number sized hash table with control of
110 * memory flags.
111 */
112void *
113phashinit_flags(int elements, struct malloc_type *type, u_long *nentries, int flags)
114{
115	long hashsize;
116	LIST_HEAD(generic, generic) *hashtbl;
117	int i;
118
119	KASSERT(elements > 0, ("%s: bad elements", __func__));
120	/* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */
121	KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT),
122	    ("Bad flags (0x%x) passed to phashinit_flags", flags));
123
124	for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
125		i++;
126		if (i == NPRIMES)
127			break;
128		hashsize = primes[i];
129	}
130	hashsize = primes[i - 1];
131
132	hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type,
133	    hash_mflags(flags));
134	if (hashtbl == NULL)
135		return (NULL);
136
137	for (i = 0; i < hashsize; i++)
138		LIST_INIT(&hashtbl[i]);
139	*nentries = hashsize;
140	return (hashtbl);
141}
142
143/*
144 * Allocate and initialize a prime number sized hash table with default flag:
145 * may sleep.
146 */
147void *
148phashinit(int elements, struct malloc_type *type, u_long *nentries)
149{
150
151	return (phashinit_flags(elements, type, nentries, HASH_WAITOK));
152}
153