| 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 | #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, 1); |
| 70 | } |
| 71 | |
| 72 | SYSINIT(kobj, SI_BOOT1_LOCK, SI_ORDER_ANY, kobj_init_token, NULL); |
| 73 | |
| 74 | /* |
| 75 | * This method structure is used to initialise new caches. Since the |
| 76 | * desc pointer is NULL, it is guaranteed never to match any real |
| 77 | * descriptors. |
| 78 | */ |
| 79 | static struct kobj_method null_method = { |
| 80 | 0, 0, |
| 81 | }; |
| 82 | |
| 83 | int |
| 84 | kobj_error_method(void) |
| 85 | { |
| 86 | return ENXIO; |
| 87 | } |
| 88 | |
| 89 | static void |
| 90 | kobj_register_method(struct kobjop_desc *desc) |
| 91 | { |
| 92 | if (desc->id == 0) |
| 93 | desc->id = kobj_next_id++; |
| 94 | } |
| 95 | |
| 96 | static void |
| 97 | kobj_unregister_method(struct kobjop_desc *desc) |
| 98 | { |
| 99 | } |
| 100 | |
| 101 | static void |
| 102 | kobj_class_compile(kobj_class_t cls) |
| 103 | { |
| 104 | kobj_method_t *m; |
| 105 | kobj_ops_t ops; |
| 106 | int i; |
| 107 | |
| 108 | /* |
| 109 | * Don't do anything if we are already compiled. |
| 110 | */ |
| 111 | if (cls->ops) |
| 112 | return; |
| 113 | |
| 114 | /* |
| 115 | * Allocate space for the compiled ops table. |
| 116 | */ |
| 117 | ops = kmalloc(sizeof(struct kobj_ops), M_KOBJ, M_INTWAIT); |
| 118 | for (i = 0; i < KOBJ_CACHE_SIZE; i++) |
| 119 | ops->cache[i] = &null_method; |
| 120 | if (cls->ops) { |
| 121 | /* |
| 122 | * In case of preemption, another thread might have been faster, |
| 123 | * but that's fine for us. |
| 124 | */ |
| 125 | if (ops) |
| 126 | kfree(ops, M_KOBJ); |
| 127 | return; |
| 128 | } |
| 129 | |
| 130 | if (!ops) |
| 131 | panic("kobj_compile_methods: out of memory"); |
| 132 | |
| 133 | ops->cls = cls; |
| 134 | cls->ops = ops; |
| 135 | |
| 136 | /* |
| 137 | * Afterwards register any methods which need it. |
| 138 | */ |
| 139 | for (m = cls->methods; m->desc; m++) |
| 140 | kobj_register_method(m->desc); |
| 141 | } |
| 142 | |
| 143 | static kobj_method_t * |
| 144 | kobj_lookup_method_class(kobj_class_t cls, kobjop_desc_t desc) |
| 145 | { |
| 146 | kobj_method_t *methods = cls->methods; |
| 147 | kobj_method_t *ce; |
| 148 | |
| 149 | for (ce = methods; ce && ce->desc; ce++) |
| 150 | if (ce->desc == desc) |
| 151 | return(ce); |
| 152 | |
| 153 | return(0); |
| 154 | } |
| 155 | |
| 156 | static kobj_method_t * |
| 157 | kobj_lookup_method_mi(kobj_class_t cls, kobjop_desc_t desc) |
| 158 | { |
| 159 | kobj_method_t *ce; |
| 160 | kobj_class_t *basep; |
| 161 | |
| 162 | ce = kobj_lookup_method_class(cls, desc); |
| 163 | if (ce) |
| 164 | return(ce); |
| 165 | |
| 166 | basep = cls->baseclasses; |
| 167 | if (basep) { |
| 168 | for (; *basep; basep++) { |
| 169 | ce = kobj_lookup_method_mi(*basep, desc); |
| 170 | if (ce) |
| 171 | return(ce); |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | return(0); |
| 176 | } |
| 177 | |
| 178 | kobj_method_t* |
| 179 | kobj_lookup_method(kobj_class_t cls, |
| 180 | kobj_method_t **cep, |
| 181 | kobjop_desc_t desc) |
| 182 | { |
| 183 | kobj_method_t *ce; |
| 184 | |
| 185 | #ifdef KOBJ_STATS |
| 186 | /* |
| 187 | * Correct for the 'hit' assumption in KOBJOPLOOKUP and record |
| 188 | * a 'miss'. |
| 189 | */ |
| 190 | kobj_lookup_hits--; |
| 191 | kobj_lookup_misses--; |
| 192 | #endif |
| 193 | |
| 194 | ce = kobj_lookup_method_mi(cls, desc); |
| 195 | if (!ce) |
| 196 | ce = desc->deflt; |
| 197 | *cep = ce; |
| 198 | return(ce); |
| 199 | } |
| 200 | |
| 201 | static void |
| 202 | kobj_class_free(kobj_class_t cls) |
| 203 | { |
| 204 | int i; |
| 205 | kobj_method_t *m; |
| 206 | |
| 207 | /* |
| 208 | * Unregister any methods which are no longer used. |
| 209 | */ |
| 210 | for (i = 0, m = cls->methods; m->desc; i++, m++) |
| 211 | kobj_unregister_method(m->desc); |
| 212 | |
| 213 | /* |
| 214 | * Free memory and clean up. |
| 215 | */ |
| 216 | kfree(cls->ops, M_KOBJ); |
| 217 | cls->ops = 0; |
| 218 | } |
| 219 | |
| 220 | void |
| 221 | kobj_class_instantiate(kobj_class_t cls) |
| 222 | { |
| 223 | lwkt_gettoken(&kobj_token); |
| 224 | crit_enter(); |
| 225 | |
| 226 | if (!cls->ops) |
| 227 | kobj_class_compile(cls); |
| 228 | cls->refs++; |
| 229 | |
| 230 | crit_exit(); |
| 231 | lwkt_reltoken(&kobj_token); |
| 232 | } |
| 233 | |
| 234 | void |
| 235 | kobj_class_uninstantiate(kobj_class_t cls) |
| 236 | { |
| 237 | lwkt_gettoken(&kobj_token); |
| 238 | crit_enter(); |
| 239 | |
| 240 | cls->refs--; |
| 241 | if (cls->refs == 0) |
| 242 | kobj_class_free(cls); |
| 243 | |
| 244 | crit_exit(); |
| 245 | lwkt_reltoken(&kobj_token); |
| 246 | } |
| 247 | |
| 248 | kobj_t |
| 249 | kobj_create(kobj_class_t cls, |
| 250 | struct malloc_type *mtype, |
| 251 | int mflags) |
| 252 | { |
| 253 | kobj_t obj; |
| 254 | |
| 255 | /* |
| 256 | * Allocate and initialise the new object. |
| 257 | */ |
| 258 | obj = kmalloc(cls->size, mtype, mflags | M_ZERO); |
| 259 | if (!obj) |
| 260 | return 0; |
| 261 | kobj_init(obj, cls); |
| 262 | |
| 263 | return obj; |
| 264 | } |
| 265 | |
| 266 | void |
| 267 | kobj_init(kobj_t obj, kobj_class_t cls) |
| 268 | { |
| 269 | kobj_class_instantiate(cls); |
| 270 | obj->ops = cls->ops; |
| 271 | } |
| 272 | |
| 273 | void |
| 274 | kobj_delete(kobj_t obj, struct malloc_type *mtype) |
| 275 | { |
| 276 | kobj_class_t cls = obj->ops->cls; |
| 277 | |
| 278 | kobj_class_uninstantiate(cls); |
| 279 | |
| 280 | obj->ops = 0; |
| 281 | if (mtype) |
| 282 | kfree(obj, mtype); |
| 283 | } |