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 46 static __inline int 47 hash_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 */ 56 void * 57 hashinit_flags(int elements, struct malloc_type *type, u_long *hashmask, 58 int flags) 59 { 60 long hashsize; 61 LIST_HEAD(generic, generic) *hashtbl; 62 int i; 63 64 KASSERT(elements > 0, ("%s: bad elements", __func__)); 65 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */ 66 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT), 67 ("Bad flags (0x%x) passed to hashinit_flags", flags)); 68 69 for (hashsize = 1; hashsize <= elements; hashsize <<= 1) 70 continue; 71 hashsize >>= 1; 72 73 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, 74 hash_mflags(flags)); 75 if (hashtbl != NULL) { 76 for (i = 0; i < hashsize; i++) 77 LIST_INIT(&hashtbl[i]); 78 *hashmask = hashsize - 1; 79 } 80 return (hashtbl); 81 } 82 83 /* 84 * Allocate and initialize a hash table with default flag: may sleep. 85 */ 86 void * 87 hashinit(int elements, struct malloc_type *type, u_long *hashmask) 88 { 89 90 return (hashinit_flags(elements, type, hashmask, HASH_WAITOK)); 91 } 92 93 void 94 hashdestroy(void *vhashtbl, struct malloc_type *type, u_long hashmask) 95 { 96 LIST_HEAD(generic, generic) *hashtbl, *hp; 97 98 hashtbl = vhashtbl; 99 for (hp = hashtbl; hp <= &hashtbl[hashmask]; hp++) 100 KASSERT(LIST_EMPTY(hp), ("%s: hashtbl %p not empty " 101 "(malloc type %s)", __func__, hashtbl, type->ks_shortdesc)); 102 free(hashtbl, type); 103 } 104 105 static const int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 106 2039, 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 107 6653, 7159, 7673, 8191, 12281, 16381, 24571, 32749 }; 108 #define NPRIMES nitems(primes) 109 110 /* 111 * General routine to allocate a prime number sized hash table with control of 112 * memory flags. 113 */ 114 void * 115 phashinit_flags(int elements, struct malloc_type *type, u_long *nentries, int flags) 116 { 117 long hashsize; 118 LIST_HEAD(generic, generic) *hashtbl; 119 int i; 120 121 KASSERT(elements > 0, ("%s: bad elements", __func__)); 122 /* Exactly one of HASH_WAITOK and HASH_NOWAIT must be set. */ 123 KASSERT((flags & HASH_WAITOK) ^ (flags & HASH_NOWAIT), 124 ("Bad flags (0x%x) passed to phashinit_flags", flags)); 125 126 for (i = 1, hashsize = primes[1]; hashsize <= elements;) { 127 i++; 128 if (i == NPRIMES) 129 break; 130 hashsize = primes[i]; 131 } 132 hashsize = primes[i - 1]; 133 134 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, 135 hash_mflags(flags)); 136 if (hashtbl == NULL) 137 return (NULL); 138 139 for (i = 0; i < hashsize; i++) 140 LIST_INIT(&hashtbl[i]); 141 *nentries = hashsize; 142 return (hashtbl); 143 } 144 145 /* 146 * Allocate and initialize a prime number sized hash table with default flag: 147 * may sleep. 148 */ 149 void * 150 phashinit(int elements, struct malloc_type *type, u_long *nentries) 151 { 152 153 return (phashinit_flags(elements, type, nentries, HASH_WAITOK)); 154 } 155