1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2000,2003 Doug Rabson 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #ifndef _SYS_KOBJ_H_ 30 #define _SYS_KOBJ_H_ 31 32 #include <sys/types.h> 33 34 /* XXX workaround for bool type for tools/build/test-includes */ 35 #if !defined(_KERNEL) && !defined(_STANDALONE) 36 #include <stdbool.h> 37 #endif 38 39 /* 40 * Forward declarations 41 */ 42 typedef struct kobj *kobj_t; 43 typedef struct kobj_class *kobj_class_t; 44 typedef const struct kobj_method kobj_method_t; 45 typedef void (*kobjop_t)(void); 46 typedef struct kobj_ops *kobj_ops_t; 47 typedef struct kobjop_desc *kobjop_desc_t; 48 struct malloc_type; 49 50 struct kobj_method { 51 kobjop_desc_t desc; 52 kobjop_t func; 53 }; 54 55 /* 56 * A class is simply a method table and a sizeof value. When the first 57 * instance of the class is created, the method table will be compiled 58 * into a form more suited to efficient method dispatch. This compiled 59 * method table is always the first field of the object. 60 */ 61 #define KOBJ_CLASS_FIELDS \ 62 const char *name; /* class name */ \ 63 kobj_method_t *methods; /* method table */ \ 64 size_t size; /* object size */ \ 65 kobj_class_t *baseclasses; /* base classes */ \ 66 u_int refs; /* reference count */ \ 67 kobj_ops_t ops; /* compiled method table */ \ 68 size_t total_size; /* total object size */ \ 69 bool total_size_inited 70 71 struct kobj_class { 72 KOBJ_CLASS_FIELDS; 73 }; 74 75 /* 76 * Implementation of kobj. 77 */ 78 #define KOBJ_FIELDS \ 79 kobj_ops_t ops 80 81 struct kobj { 82 KOBJ_FIELDS; 83 }; 84 85 /* 86 * The ops table is used as a cache of results from kobj_lookup_method(). 87 */ 88 89 #define KOBJ_CACHE_SIZE 256 90 91 struct kobj_ops { 92 kobj_method_t *cache[KOBJ_CACHE_SIZE]; 93 kobj_class_t cls; 94 }; 95 96 struct kobjop_desc { 97 unsigned int id; /* unique ID */ 98 kobj_method_t deflt; /* default implementation */ 99 }; 100 101 /* 102 * Shorthand for constructing method tables. 103 * The ternary operator is (ab)used to provoke a warning when FUNC 104 * has a signature that is not compatible with kobj method signature. 105 */ 106 #define KOBJMETHOD(NAME, FUNC) \ 107 { &NAME##_desc, (kobjop_t) (1 ? FUNC : (NAME##_t *)NULL) } 108 109 /* 110 * 111 */ 112 #define KOBJMETHOD_END { NULL, NULL } 113 114 /* 115 * Declare a class (which should be defined in another file. 116 */ 117 #define DECLARE_CLASS(name) extern struct kobj_class name 118 119 /* 120 * Define a class with no base classes (api backward-compatible. with 121 * FreeBSD-5.1 and earlier). 122 */ 123 #define DEFINE_CLASS(name, methods, size) \ 124 DEFINE_CLASS_0(name, name ## _class, methods, size) 125 126 /* 127 * Define a class with no base classes. Use like this: 128 * 129 * DEFINE_CLASS_0(foo, foo_class, foo_methods, sizeof(foo_softc)); 130 */ 131 #define DEFINE_CLASS_0(name, classvar, methods, size) \ 132 \ 133 struct kobj_class classvar = { \ 134 #name, methods, size, NULL, 0, false \ 135 } 136 137 /* 138 * Define a class inheriting a single base class. Use like this: 139 * 140 * DEFINE_CLASS_1(foo, foo_class, foo_methods, sizeof(foo_softc), 141 * bar); 142 */ 143 #define DEFINE_CLASS_1(name, classvar, methods, size, \ 144 base1) \ 145 \ 146 static kobj_class_t name ## _baseclasses[] = \ 147 { &base1, NULL }; \ 148 struct kobj_class classvar = { \ 149 #name, methods, size, name ## _baseclasses, 0, \ 150 false \ 151 } 152 153 /* 154 * Define a class inheriting two base classes. Use like this: 155 * 156 * DEFINE_CLASS_2(foo, foo_class, foo_methods, sizeof(foo_softc), 157 * bar, baz); 158 */ 159 #define DEFINE_CLASS_2(name, classvar, methods, size, \ 160 base1, base2) \ 161 \ 162 static kobj_class_t name ## _baseclasses[] = \ 163 { &base1, \ 164 &base2, NULL }; \ 165 struct kobj_class classvar = { \ 166 #name, methods, size, name ## _baseclasses, 0, \ 167 false \ 168 } 169 170 /* 171 * Define a class inheriting three base classes. Use like this: 172 * 173 * DEFINE_CLASS_3(foo, foo_class, foo_methods, sizeof(foo_softc), 174 * bar, baz, foobar); 175 */ 176 #define DEFINE_CLASS_3(name, classvar, methods, size, \ 177 base1, base2, base3) \ 178 \ 179 static kobj_class_t name ## _baseclasses[] = \ 180 { &base1, \ 181 &base2, \ 182 &base3, NULL }; \ 183 struct kobj_class classvar = { \ 184 #name, methods, size, name ## _baseclasses, 0, \ 185 false \ 186 } 187 188 /* 189 * Compile the method table in a class. 190 */ 191 void kobj_class_compile(kobj_class_t cls); 192 193 /* 194 * Compile the method table, with the caller providing the space for 195 * the ops table.(for use before malloc is initialised). 196 */ 197 void kobj_class_compile_static(kobj_class_t cls, kobj_ops_t ops); 198 199 /* 200 * Free the compiled method table in a class. 201 */ 202 void kobj_class_free(kobj_class_t cls); 203 204 /* 205 * Allocate memory for and initialise a new object. 206 */ 207 kobj_t kobj_create(kobj_class_t cls, 208 struct malloc_type *mtype, 209 int mflags); 210 211 /* 212 * Initialise a pre-allocated object. 213 */ 214 void kobj_init(kobj_t obj, kobj_class_t cls); 215 void kobj_init_static(kobj_t obj, kobj_class_t cls); 216 217 /* 218 * Delete an object. If mtype is non-zero, free the memory. 219 */ 220 void kobj_delete(kobj_t obj, struct malloc_type *mtype); 221 222 /* 223 * Get the data offset for the given class. 224 */ 225 size_t kobj_instance_offset(kobj_class_t cls, kobj_class_t subclass); 226 227 /* 228 * Get the total data size of this class and all its subclasses. 229 */ 230 size_t kobj_total_data_size(kobj_class_t cls); 231 232 /* 233 * Maintain stats on hits/misses in lookup caches. 234 */ 235 #ifdef KOBJ_STATS 236 extern u_int kobj_lookup_hits; 237 extern u_int kobj_lookup_misses; 238 #endif 239 240 /* 241 * Lookup the method in the cache and if it isn't there look it up the 242 * slow way. 243 */ 244 #ifdef KOBJ_STATS 245 #define KOBJOPLOOKUP(OPS,OP) do { \ 246 kobjop_desc_t _desc = &OP##_##desc; \ 247 kobj_method_t **_cep = \ 248 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 249 kobj_method_t *_ce = *_cep; \ 250 if (_ce->desc != _desc) { \ 251 _ce = kobj_lookup_method(OPS->cls, \ 252 _cep, _desc); \ 253 kobj_lookup_misses++; \ 254 } else \ 255 kobj_lookup_hits++; \ 256 _m = _ce->func; \ 257 } while (0) 258 #else 259 #define KOBJOPLOOKUP(OPS,OP) do { \ 260 kobjop_desc_t _desc = &OP##_##desc; \ 261 kobj_method_t **_cep = \ 262 &OPS->cache[_desc->id & (KOBJ_CACHE_SIZE-1)]; \ 263 kobj_method_t *_ce = *_cep; \ 264 if (_ce->desc != _desc) \ 265 _ce = kobj_lookup_method(OPS->cls, \ 266 _cep, _desc); \ 267 _m = _ce->func; \ 268 } while (0) 269 #endif 270 271 kobj_method_t* kobj_lookup_method(kobj_class_t cls, 272 kobj_method_t **cep, 273 kobjop_desc_t desc); 274 275 /* 276 * Default method implementation. Returns ENXIO. 277 */ 278 int kobj_error_method(void); 279 280 #endif /* !_SYS_KOBJ_H_ */ 281