sys/sys/kobj.h

   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/sys/kobj.h,v 1.8 2003/09/22 21:32:49 peter Exp $
  27  */
  28
  29 #ifndef _SYS_KOBJ_H_
  30 #define _SYS_KOBJ_H_
  31
  32 #ifndef _SYS_TYPES_H_
  33 #include <sys/types.h>
  34 #endif
  35
  36 #if !defined(_KERNEL) && !defined(_KERNEL_STRUCTURES)
  37 #error "This file should not be included by userland programs."
  38 #endif
  39
  40 /*
  41  * Forward declarations
  42  */
  43 typedef struct kobj             *kobj_t;
  44 typedef struct kobj_class       *kobj_class_t;
  45 typedef const struct kobj_method kobj_method_t;
  46 typedef int                     (*kobjop_t)(void);
  47 typedef struct kobj_ops         *kobj_ops_t;
  48 typedef struct kobjop_desc      *kobjop_desc_t;
  49 struct malloc_type;
  50
  51 struct kobj_method {
  52         kobjop_desc_t   desc;
  53         kobjop_t        func;
  54 };
  55
  56 /*
  57  * A class is simply a method table and a sizeof value. When the first
  58  * instance of the class is created, the method table will be compiled
  59  * into a form more suited to efficient method dispatch. This compiled
  60  * method table is always the first field of the object.
  61  */
  62 #define KOBJ_CLASS_FIELDS                                               \
  63         const char      *name;          /* class name */                \
  64         kobj_method_t   *methods;       /* method table */              \
  65         size_t          size;           /* object size */               \
  66         kobj_class_t    *baseclasses;   /* base classes */              \
  67         u_int           refs;           /* reference count */           \
  68         kobj_ops_t      ops;            /* compiled method table */     \
  69         u_int           gpri            /* global probe/attach pri */
  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  * gpri values (higher values probe/attach first, allows us to
  87  * default the field to 0).
  88  */
  89 #define KOBJ_GPRI_ACPI          0x00FFU
  90 #define KOBJ_GPRI_LAST          0x0000U
  91 #define KOBJ_GPRI_DEFAULT       KOBJ_GPRI_LAST
  92
  93 /*
  94  * The ops table is used as a cache of results from kobj_lookup_method().
  95  */
  96
  97 #define KOBJ_CACHE_SIZE 256
  98
  99 struct kobj_ops {
 100         kobj_method_t   *cache[KOBJ_CACHE_SIZE];
 101         kobj_class_t    cls;
 102 };
 103
 104 struct kobjop_desc {
 105         unsigned int    id;     /* unique ID */
 106         kobj_method_t   deflt;  /* default implementation */
 107 };
 108
 109 /*
 110  * Shorthand for constructing method tables.
 111  */
 112 #define KOBJMETHOD(NAME, FUNC) { &NAME##_desc, (kobjop_t) FUNC }
 113 #define KOBJMETHOD_END  { NULL, NULL }
 114
 115 /*
 116  * Declare a class (which should be defined in another file.
 117  */
 118 #define DECLARE_CLASS(name) extern struct kobj_class name
 119
 120 /*
 121  * Define a class with no base classes (api backward-compatible. with
 122  * FreeBSD-5.1 and earlier).
 123  */
 124 #define DEFINE_CLASS(name, methods, size)               \
 125 DEFINE_CLASS_0(name, name ## _class, methods, size)
 126
 127 /*
 128  * Define a class with no base classes. Use like this:
 129  *
 130  * DEFINE_CLASS_0(foo, foo_class, foo_methods, sizeof(foo_softc));
 131  */
 132 #define DEFINE_CLASS_0(name, classvar, methods, size)   \
 133                                                         \
 134 struct kobj_class classvar = {                          \
 135         #name, methods, size, NULL, 0, NULL             \
 136 }
 137
 138 /*
 139  * Define a class with no base classes using the named structure
 140  * as an extension of the kobj_class structure.
 141  */
 142 #define DEFINE_CLASS_EXT(name, classvar, methods, size, extname)        \
 143                                                         \
 144 struct extname classvar = {                             \
 145         #name, methods, size, NULL, 0, NULL             \
 146 }
 147
 148 /*
 149  * Define a class inheriting a single base class. Use like this:
 150  *
 151  * DEFINE_CLASS1(foo, foo_class, foo_methods, sizeof(foo_softc),
 152  *                        bar);
 153  */
 154 #define DEFINE_CLASS_1(name, classvar, methods, size,   \
 155                        base1)                           \
 156                                                         \
 157 static kobj_class_t name ## _baseclasses[] = {          \
 158         &base1, 0                                       \
 159 };                                                      \
 160 struct kobj_class classvar = {                          \
 161         #name, methods, size, name ## _baseclasses      \
 162 }
 163
 164 /*
 165  * Define a class inheriting two base classes. Use like this:
 166  *
 167  * DEFINE_CLASS2(foo, foo_class, foo_methods, sizeof(foo_softc),
 168  *                        bar, baz);
 169  */
 170 #define DEFINE_CLASS_2(name, methods, size,             \
 171                        base1, base2)                    \
 172                                                         \
 173 static kobj_class_t name ## _baseclasses[] = {          \
 174         &base1,                                         \
 175         &base2, 0                                       \
 176 };                                                      \
 177 struct kobj_class name ## _class = {                    \
 178         #name, methods, size, name ## _baseclasses      \
 179 }
 180
 181 /*
 182  * Define a class inheriting three base classes. Use like this:
 183  *
 184  * DEFINE_CLASS3(foo, foo_class, foo_methods, sizeof(foo_softc),
 185  *                        bar, baz, foobar);
 186  */
 187 #define DEFINE_CLASS_3(name, methods, size,             \
 188                        base1, base2, base3)             \
 189                                                         \
 190 static kobj_class_t name ## _baseclasses[] = {          \
 191         &base1,                                         \
 192         &base2,                                         \
 193         &base3, 0                                       \
 194 };                                                      \
 195 struct kobj_class name ## _class = {                    \
 196         #name, methods, size, name ## _baseclasses      \
 197 }
 198
 199 #ifdef _KERNEL
 200
 201 /*
 202  * Compile class for the first instance and add a reference.
 203  */
 204 void            kobj_class_instantiate(kobj_class_t cls);
 205
 206 /*
 207  * Remove a reference and free method table with the last instance.
 208  */
 209 void            kobj_class_uninstantiate(kobj_class_t cls);
 210
 211 /*
 212  * Allocate memory for and initialise a new object.
 213  */
 214 kobj_t          kobj_create(kobj_class_t cls,
 215                             struct malloc_type *mtype,
 216                             int mflags);
 217
 218 /*
 219  * Initialise a pre-allocated object.
 220  */
 221 void            kobj_init(kobj_t obj, kobj_class_t cls);
 222
 223 /*
 224  * Delete an object. If mtype is non-zero, free the memory.
 225  */
 226 void            kobj_delete(kobj_t obj, struct malloc_type *mtype);
 227
 228 /*
 229  * Lookup the method in the cache and if it isn't there look it up the
 230  * slow way.
 231  *
 232  * We do the cache inside kobj_lookup_method() now, we don't try to
 233  * expand it because it's really silly.  These lookups are not in the
 234  * critical path.
 235  */
 236
 237 #define KOBJOPLOOKUP(OPS,OP) do {                                       \
 238         _m = kobj_lookup_method_cache(OPS->cls, &OPS->cache[0],         \
 239                                        &OP##_##desc);                   \
 240 } while(0)
 241
 242 kobj_method_t *kobj_lookup_method(kobj_class_t cls,
 243                                   kobj_method_t **cep,
 244                                   kobjop_desc_t desc);
 245
 246 kobjop_t kobj_lookup_method_cache(kobj_class_t cls,
 247                                   kobj_method_t **cep,
 248                                   kobjop_desc_t desc);
 249
 250 /*
 251  * Default method implementation. Returns ENXIO.
 252  */
 253 int kobj_error_method(void);
 254
 255 #endif /* _KERNEL */
 256
 257 #endif /* !_SYS_KOBJ_H_ */