1 /*- 2 * Copyright (c) 2000 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: src/sys/kern/subr_kobj.c,v 1.4.2.1 2001/02/02 19:49:13 cg Exp $ 27 * $DragonFly: src/sys/kern/subr_kobj.c,v 1.6 2004/04/01 13:50:47 joerg Exp $ 28 */ 29 30 #include <sys/param.h> 31 #include <sys/queue.h> 32 #include <sys/malloc.h> 33 #include <sys/kernel.h> 34 #include <sys/module.h> 35 #include <sys/errno.h> 36 #include <sys/thread.h> 37 #include <sys/thread2.h> 38 #ifndef TEST 39 #include <sys/systm.h> 40 #endif 41 #include <sys/kobj.h> 42 43 #ifdef TEST 44 #include "usertest.h" 45 #endif 46 47 static MALLOC_DEFINE(M_KOBJ, "kobj", "Kernel object structures"); 48 49 #ifdef KOBJ_STATS 50 51 #include <sys/sysctl.h> 52 53 u_int kobj_lookup_hits; 54 u_int kobj_lookup_misses; 55 56 SYSCTL_UINT(_kern, OID_AUTO, kobj_hits, CTLFLAG_RD, 57 &kobj_lookup_hits, 0, "") 58 SYSCTL_UINT(_kern, OID_AUTO, kobj_misses, CTLFLAG_RD, 59 &kobj_lookup_misses, 0, "") 60 61 #endif 62 63 static struct lwkt_token kobj_token; 64 static int kobj_next_id = 1; 65 66 static void 67 kobj_init_token(void *arg) 68 { 69 lwkt_token_init(&kobj_token); 70 } 71 72 SYSINIT(kobj, SI_SUB_LOCK, SI_ORDER_ANY, kobj_init_token, NULL); 73 74 static int 75 kobj_error_method(void) 76 { 77 return ENXIO; 78 } 79 80 static void 81 kobj_register_method(struct kobjop_desc *desc) 82 { 83 if (desc->id == 0) 84 desc->id = kobj_next_id++; 85 } 86 87 static void 88 kobj_unregister_method(struct kobjop_desc *desc) 89 { 90 } 91 92 static void 93 kobj_class_compile(kobj_class_t cls) 94 { 95 kobj_method_t *m; 96 kobj_ops_t ops; 97 98 /* 99 * Don't do anything if we are already compiled. 100 */ 101 if (cls->ops) 102 return; 103 104 /* 105 * Allocate space for the compiled ops table. 106 */ 107 ops = malloc(sizeof(struct kobj_ops), M_KOBJ, M_INTWAIT | M_ZERO); 108 if (cls->ops) { 109 /* 110 * In case of preemption, another thread might have been faster, 111 * but that's fine for us. 112 */ 113 if (ops) 114 free(ops, M_KOBJ); 115 return; 116 } 117 118 if (!ops) 119 panic("kobj_compile_methods: out of memory"); 120 121 ops->cls = cls; 122 cls->ops = ops; 123 124 /* 125 * Afterwards register any methods which need it. 126 */ 127 for (m = cls->methods; m->desc; m++) 128 kobj_register_method(m->desc); 129 } 130 131 void 132 kobj_lookup_method(kobj_method_t *methods, 133 kobj_method_t *ce, 134 kobjop_desc_t desc) 135 { 136 ce->desc = desc; 137 for (; methods && methods->desc; methods++) { 138 if (methods->desc == desc) { 139 ce->func = methods->func; 140 return; 141 } 142 } 143 if (desc->deflt) 144 ce->func = desc->deflt; 145 else 146 ce->func = kobj_error_method; 147 return; 148 } 149 150 static void 151 kobj_class_free(kobj_class_t cls) 152 { 153 int i; 154 kobj_method_t *m; 155 156 /* 157 * Unregister any methods which are no longer used. 158 */ 159 for (i = 0, m = cls->methods; m->desc; i++, m++) 160 kobj_unregister_method(m->desc); 161 162 /* 163 * Free memory and clean up. 164 */ 165 free(cls->ops, M_KOBJ); 166 cls->ops = 0; 167 } 168 169 void 170 kobj_class_instantiate(kobj_class_t cls) 171 { 172 lwkt_tokref ilock; 173 174 lwkt_gettoken(&ilock, &kobj_token); 175 crit_enter(); 176 177 if (!cls->ops) 178 kobj_class_compile(cls); 179 cls->refs++; 180 181 crit_exit(); 182 lwkt_reltoken(&ilock); 183 } 184 185 void 186 kobj_class_uninstantiate(kobj_class_t cls) 187 { 188 lwkt_tokref ilock; 189 190 lwkt_gettoken(&ilock, &kobj_token); 191 crit_enter(); 192 193 cls->refs--; 194 if (cls->refs == 0) 195 kobj_class_free(cls); 196 197 crit_exit(); 198 lwkt_reltoken(&ilock); 199 } 200 201 kobj_t 202 kobj_create(kobj_class_t cls, 203 struct malloc_type *mtype, 204 int mflags) 205 { 206 kobj_t obj; 207 208 /* 209 * Allocate and initialise the new object. 210 */ 211 obj = malloc(cls->size, mtype, mflags | M_ZERO); 212 if (!obj) 213 return 0; 214 kobj_init(obj, cls); 215 216 return obj; 217 } 218 219 void 220 kobj_init(kobj_t obj, kobj_class_t cls) 221 { 222 kobj_class_instantiate(cls); 223 obj->ops = cls->ops; 224 } 225 226 void 227 kobj_delete(kobj_t obj, struct malloc_type *mtype) 228 { 229 kobj_class_t cls = obj->ops->cls; 230 231 kobj_class_uninstantiate(cls); 232 233 obj->ops = 0; 234 if (mtype) 235 free(obj, mtype); 236 } 237