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 1.3 2003/11/22 08:39:46 asmodai 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 #ifndef TEST 37 #include <sys/systm.h> 38 #endif 39 #include <sys/kobj.h> 40 41 #ifdef TEST 42 #include "usertest.h" 43 #endif 44 45 static MALLOC_DEFINE(M_KOBJ, "kobj", "Kernel object structures"); 46 47 #ifdef KOBJ_STATS 48 49 #include <sys/sysctl.h> 50 51 u_int kobj_lookup_hits; 52 u_int kobj_lookup_misses; 53 54 SYSCTL_UINT(_kern, OID_AUTO, kobj_hits, CTLFLAG_RD, 55 &kobj_lookup_hits, 0, "") 56 SYSCTL_UINT(_kern, OID_AUTO, kobj_misses, CTLFLAG_RD, 57 &kobj_lookup_misses, 0, "") 58 59 #endif 60 61 static int kobj_next_id = 1; 62 63 static int 64 kobj_error_method(void) 65 { 66 return ENXIO; 67 } 68 69 static void 70 kobj_register_method(struct kobjop_desc *desc) 71 { 72 if (desc->id == 0) 73 desc->id = kobj_next_id++; 74 } 75 76 static void 77 kobj_unregister_method(struct kobjop_desc *desc) 78 { 79 } 80 81 static void 82 kobj_class_compile_common(kobj_class_t cls, kobj_ops_t ops) 83 { 84 kobj_method_t *m; 85 int i; 86 87 /* 88 * Don't do anything if we are already compiled. 89 */ 90 if (cls->ops) 91 return; 92 93 /* 94 * First register any methods which need it. 95 */ 96 for (i = 0, m = cls->methods; m->desc; i++, m++) 97 kobj_register_method(m->desc); 98 99 /* 100 * Then initialise the ops table. 101 */ 102 bzero(ops, sizeof(struct kobj_ops)); 103 ops->cls = cls; 104 cls->ops = ops; 105 } 106 107 void 108 kobj_class_compile(kobj_class_t cls) 109 { 110 kobj_ops_t ops; 111 112 /* 113 * Allocate space for the compiled ops table. 114 */ 115 ops = malloc(sizeof(struct kobj_ops), M_KOBJ, M_NOWAIT); 116 if (!ops) 117 panic("kobj_compile_methods: out of memory"); 118 kobj_class_compile_common(cls, ops); 119 } 120 121 void 122 kobj_class_compile_static(kobj_class_t cls, kobj_ops_t ops) 123 { 124 /* 125 * Increment refs to make sure that the ops table is not freed. 126 */ 127 cls->refs++; 128 kobj_class_compile_common(cls, ops); 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 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 kobj_t 170 kobj_create(kobj_class_t cls, 171 struct malloc_type *mtype, 172 int mflags) 173 { 174 kobj_t obj; 175 176 /* 177 * Allocate and initialise the new object. 178 */ 179 obj = malloc(cls->size, mtype, mflags | M_ZERO); 180 if (!obj) 181 return 0; 182 kobj_init(obj, cls); 183 184 return obj; 185 } 186 187 void 188 kobj_init(kobj_t obj, kobj_class_t cls) 189 { 190 /* 191 * Consider compiling the class' method table. 192 */ 193 if (!cls->ops) 194 kobj_class_compile(cls); 195 196 obj->ops = cls->ops; 197 cls->refs++; 198 } 199 200 void 201 kobj_delete(kobj_t obj, struct malloc_type *mtype) 202 { 203 kobj_class_t cls = obj->ops->cls; 204 205 /* 206 * Consider freeing the compiled method table for the class 207 * after its last instance is deleted. As an optimisation, we 208 * should defer this for a short while to avoid thrashing. 209 */ 210 cls->refs--; 211 if (!cls->refs) 212 kobj_class_free(cls); 213 214 obj->ops = 0; 215 if (mtype) 216 free(obj, mtype); 217 } 218