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__FBSDID("$FreeBSD$");
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/malloc.h>
45
46static __inline int
47hash_mflags(int flags)
48{
49
50	return ((flags & HASH_NOWAIT) ? M_NOWAIT : M_WAITOK);
51}
52
53/*
54 * General routine to allocate a hash table with control of memory flags.
55 */
56void *
57hashinit_flags(int elements, struct malloc_type *type, u_long *hashmask,
58    int flags)
59{
60	long hashsize, i;
61	LIST_HEAD(generic, generic) *hashtbl;
62
63	KASSERT(elements > 0, ("%s: bad elements", __func__));
64	/* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */
65	KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT),
66	    ("Bad flags (0x%x) passed to hashinit_flags", flags));
67
68	for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
69		continue;
70	hashsize >>= 1;
71
72	hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type,
73	    hash_mflags(flags));
74	if (hashtbl != NULL) {
75		for (i = 0; i < hashsize; i++)
76			LIST_INIT(&hashtbl[i]);
77		*hashmask = hashsize - 1;
78	}
79	return (hashtbl);
80}
81
82/*
83 * Allocate and initialize a hash table with default flag: may sleep.
84 */
85void *
86hashinit(int elements, struct malloc_type *type, u_long *hashmask)
87{
88
89	return (hashinit_flags(elements, type, hashmask, HASH_WAITOK));
90}
91
92void
93hashdestroy(void *vhashtbl, struct malloc_type *type, u_long hashmask)
94{
95	LIST_HEAD(generic, generic) *hashtbl, *hp;
96
97	hashtbl = vhashtbl;
98	for (hp = hashtbl; hp <= &hashtbl[hashmask]; hp++)
99		KASSERT(LIST_EMPTY(hp), ("%s: hashtbl %p not empty "
100		    "(malloc type %s)", __func__, hashtbl, type->ks_shortdesc));
101	free(hashtbl, type);
102}
103
104static const int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531,
105			2039, 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143,
106			6653, 7159, 7673, 8191, 12281, 16381, 24571, 32749 };
107#define	NPRIMES nitems(primes)
108
109/*
110 * General routine to allocate a prime number sized hash table with control of
111 * memory flags.
112 */
113void *
114phashinit_flags(int elements, struct malloc_type *type, u_long *nentries, int flags)
115{
116	long hashsize, i;
117	LIST_HEAD(generic, generic) *hashtbl;
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