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 1.9 2007/04/30 07:18:54 dillon 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 static struct lwkt_token kobj_token; 50 static int kobj_next_id = 1; 51 52 static void 53 kobj_init_token(void *arg) 54 { 55 lwkt_token_init(&kobj_token, "kobj"); 56 } 57 58 SYSINIT(kobj, SI_BOOT1_LOCK, SI_ORDER_ANY, kobj_init_token, NULL); 59 60 /* 61 * This method structure is used to initialise new caches. Since the 62 * desc pointer is NULL, it is guaranteed never to match any real 63 * descriptors. 64 */ 65 static struct kobj_method null_method = { 66 0, 0, 67 }; 68 69 int 70 kobj_error_method(void) 71 { 72 return ENXIO; 73 } 74 75 static void 76 kobj_register_method(struct kobjop_desc *desc) 77 { 78 if (desc->id == 0) 79 desc->id = kobj_next_id++; 80 } 81 82 static void 83 kobj_unregister_method(struct kobjop_desc *desc) 84 { 85 } 86 87 static void 88 kobj_class_compile(kobj_class_t cls) 89 { 90 kobj_method_t *m; 91 kobj_ops_t ops; 92 int i; 93 94 /* 95 * Don't do anything if we are already compiled. 96 */ 97 if (cls->ops) 98 return; 99 100 /* 101 * Allocate space for the compiled ops table. 102 */ 103 ops = kmalloc(sizeof(struct kobj_ops), M_KOBJ, M_INTWAIT); 104 for (i = 0; i < KOBJ_CACHE_SIZE; i++) 105 ops->cache[i] = &null_method; 106 if (cls->ops) { 107 /* 108 * In case of preemption, another thread might have been faster, 109 * but that's fine for us. 110 */ 111 if (ops) 112 kfree(ops, M_KOBJ); 113 return; 114 } 115 116 if (!ops) 117 panic("kobj_compile_methods: out of memory"); 118 119 ops->cls = cls; 120 cls->ops = ops; 121 122 /* 123 * Afterwards register any methods which need it. 124 */ 125 for (m = cls->methods; m->desc; m++) 126 kobj_register_method(m->desc); 127 } 128 129 static kobj_method_t * 130 kobj_lookup_method_class(kobj_class_t cls, kobjop_desc_t desc) 131 { 132 kobj_method_t *methods = cls->methods; 133 kobj_method_t *ce; 134 135 for (ce = methods; ce && ce->desc; ce++) 136 if (ce->desc == desc) 137 return(ce); 138 139 return(0); 140 } 141 142 static kobj_method_t * 143 kobj_lookup_method_mi(kobj_class_t cls, kobjop_desc_t desc) 144 { 145 kobj_method_t *ce; 146 kobj_class_t *basep; 147 148 ce = kobj_lookup_method_class(cls, desc); 149 if (ce) 150 return(ce); 151 152 basep = cls->baseclasses; 153 if (basep) { 154 for (; *basep; basep++) { 155 ce = kobj_lookup_method_mi(*basep, desc); 156 if (ce) 157 return(ce); 158 } 159 } 160 161 return(0); 162 } 163 164 kobj_method_t* 165 kobj_lookup_method(kobj_class_t cls, 166 kobj_method_t **cep, 167 kobjop_desc_t desc) 168 { 169 kobj_method_t *ce; 170 171 ce = kobj_lookup_method_mi(cls, desc); 172 if (!ce) 173 ce = desc->deflt; 174 *cep = ce; 175 return(ce); 176 } 177 178 /* 179 * This is called from the KOBJOPLOOKUP() macro in sys/kobj.h and 180 * replaces the original large body of the macro with a single 181 * procedure call. 182 */ 183 kobjop_t 184 kobj_lookup_method_cache(kobj_class_t cls, kobj_method_t **cep, 185 kobjop_desc_t desc) 186 { 187 kobj_method_t *ce; 188 189 cep = &cep[desc->id & (KOBJ_CACHE_SIZE-1)]; 190 ce = *cep; 191 if (ce->desc != desc) 192 ce = kobj_lookup_method(cls, cep, desc); 193 return(ce->func); 194 } 195 196 static void 197 kobj_class_free(kobj_class_t cls) 198 { 199 int i; 200 kobj_method_t *m; 201 202 /* 203 * Unregister any methods which are no longer used. 204 */ 205 for (i = 0, m = cls->methods; m->desc; i++, m++) 206 kobj_unregister_method(m->desc); 207 208 /* 209 * Free memory and clean up. 210 */ 211 kfree(cls->ops, M_KOBJ); 212 cls->ops = 0; 213 } 214 215 void 216 kobj_class_instantiate(kobj_class_t cls) 217 { 218 lwkt_gettoken(&kobj_token); 219 crit_enter(); 220 221 if (!cls->ops) 222 kobj_class_compile(cls); 223 cls->refs++; 224 225 crit_exit(); 226 lwkt_reltoken(&kobj_token); 227 } 228 229 void 230 kobj_class_uninstantiate(kobj_class_t cls) 231 { 232 lwkt_gettoken(&kobj_token); 233 crit_enter(); 234 235 cls->refs--; 236 if (cls->refs == 0) 237 kobj_class_free(cls); 238 239 crit_exit(); 240 lwkt_reltoken(&kobj_token); 241 } 242 243 kobj_t 244 kobj_create(kobj_class_t cls, 245 struct malloc_type *mtype, 246 int mflags) 247 { 248 kobj_t obj; 249 250 /* 251 * Allocate and initialise the new object. 252 */ 253 obj = kmalloc(cls->size, mtype, mflags | M_ZERO); 254 if (!obj) 255 return 0; 256 kobj_init(obj, cls); 257 258 return obj; 259 } 260 261 void 262 kobj_init(kobj_t obj, kobj_class_t cls) 263 { 264 kobj_class_instantiate(cls); 265 obj->ops = cls->ops; 266 } 267 268 void 269 kobj_delete(kobj_t obj, struct malloc_type *mtype) 270 { 271 kobj_class_t cls = obj->ops->cls; 272 273 kobj_class_uninstantiate(cls); 274 275 obj->ops = 0; 276 if (mtype) 277 kfree(obj, mtype); 278 } 279