sys/sys/eventhandler.h

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 1999 Michael Smith <msmith@freebsd.org>
   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  * $FreeBSD$
  29  */
  30
  31 #ifndef _SYS_EVENTHANDLER_H_
  32 #define _SYS_EVENTHANDLER_H_
  33
  34 #include <sys/lock.h>
  35 #include <sys/ktr.h>
  36 #include <sys/mutex.h>
  37 #include <sys/queue.h>
  38
  39 struct eventhandler_entry {
  40         TAILQ_ENTRY(eventhandler_entry) ee_link;
  41         int                             ee_priority;
  42 #define EHE_DEAD_PRIORITY       (-1)
  43         void                            *ee_arg;
  44 };
  45
  46 #ifdef VIMAGE
  47 struct eventhandler_entry_vimage {
  48         void    (* func)(void);         /* Original function registered. */
  49         void    *ee_arg;                /* Original argument registered. */
  50         void    *sparep[2];
  51 };
  52 #endif
  53
  54 struct eventhandler_list {
  55         char                            *el_name;
  56         int                             el_flags;       /* Unused. */
  57         u_int                           el_runcount;
  58         struct mtx                      el_lock;
  59         TAILQ_ENTRY(eventhandler_list)  el_link;
  60         TAILQ_HEAD(,eventhandler_entry) el_entries;
  61 };
  62
  63 typedef struct eventhandler_entry       *eventhandler_tag;
  64
  65 #define EHL_LOCK(p)             mtx_lock(&(p)->el_lock)
  66 #define EHL_UNLOCK(p)           mtx_unlock(&(p)->el_lock)
  67 #define EHL_LOCK_ASSERT(p, x)   mtx_assert(&(p)->el_lock, x)
  68
  69 /*
  70  * Macro to invoke the handlers for a given event.
  71  */
  72 #define _EVENTHANDLER_INVOKE(name, list, ...) do {                      \
  73         struct eventhandler_entry *_ep;                                 \
  74         struct eventhandler_entry_ ## name *_t;                         \
  75                                                                         \
  76         EHL_LOCK_ASSERT((list), MA_OWNED);                              \
  77         (list)->el_runcount++;                                          \
  78         KASSERT((list)->el_runcount > 0,                                \
  79             ("eventhandler_invoke: runcount overflow"));                \
  80         CTR0(KTR_EVH, "eventhandler_invoke(\"" __STRING(name) "\")");   \
  81         TAILQ_FOREACH(_ep, &((list)->el_entries), ee_link) {            \
  82                 if (_ep->ee_priority != EHE_DEAD_PRIORITY) {            \
  83                         EHL_UNLOCK((list));                             \
  84                         _t = (struct eventhandler_entry_ ## name *)_ep; \
  85                         CTR1(KTR_EVH, "eventhandler_invoke: executing %p", \
  86                             (void *)_t->eh_func);                       \
  87                         _t->eh_func(_ep->ee_arg , ## __VA_ARGS__);      \
  88                         EHL_LOCK((list));                               \
  89                 }                                                       \
  90         }                                                               \
  91         KASSERT((list)->el_runcount > 0,                                \
  92             ("eventhandler_invoke: runcount underflow"));               \
  93         (list)->el_runcount--;                                          \
  94         if ((list)->el_runcount == 0)                                   \
  95                 eventhandler_prune_list(list);                          \
  96         EHL_UNLOCK((list));                                             \
  97 } while (0)
  98
  99 /*
 100  * You can optionally use the EVENTHANDLER_LIST and EVENTHANDLER_DIRECT macros
 101  * to pre-define a symbol for the eventhandler list. This symbol can be used by
 102  * EVENTHANDLER_DIRECT_INVOKE, which has the advantage of not needing to do a
 103  * locked search of the global list of eventhandler lists. At least
 104  * EVENTHANDLER_LIST_DEFINE must be be used for EVENTHANDLER_DIRECT_INVOKE to
 105  * work. EVENTHANDLER_LIST_DECLARE is only needed if the call to
 106  * EVENTHANDLER_DIRECT_INVOKE is in a different compilation unit from
 107  * EVENTHANDLER_LIST_DEFINE. If the events are even relatively high frequency
 108  * it is suggested that you directly define a list for them.
 109  */
 110 #define EVENTHANDLER_LIST_DECLARE(name)                                 \
 111 extern struct eventhandler_list *_eventhandler_list_ ## name            \
 112
 113 #define EVENTHANDLER_LIST_DEFINE(name)                                  \
 114 struct eventhandler_list *_eventhandler_list_ ## name ;                 \
 115 static void _ehl_init_ ## name (void * ctx __unused)                    \
 116 {                                                                       \
 117         _eventhandler_list_ ## name = eventhandler_create_list(#name);  \
 118 }                                                                       \
 119 SYSINIT(name ## _ehl_init, SI_SUB_EVENTHANDLER, SI_ORDER_ANY,           \
 120             _ehl_init_ ## name, NULL);                                  \
 121         struct __hack
 122
 123 #define EVENTHANDLER_DIRECT_INVOKE(name, ...) do {                      \
 124         struct eventhandler_list *_el;                                  \
 125                                                                         \
 126         _el = _eventhandler_list_ ## name ;                             \
 127         if (!TAILQ_EMPTY(&_el->el_entries)) {                           \
 128                 EHL_LOCK(_el);                                          \
 129                 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);       \
 130         }                                                               \
 131 } while (0)
 132
 133 /*
 134  * Event handlers need to be declared, but do not need to be defined. The
 135  * declaration must be in scope wherever the handler is to be invoked.
 136  */
 137 #define EVENTHANDLER_DECLARE(name, type)                                \
 138 struct eventhandler_entry_ ## name                                      \
 139 {                                                                       \
 140         struct eventhandler_entry       ee;                             \
 141         type                            eh_func;                        \
 142 };                                                                      \
 143 struct __hack
 144
 145 #define EVENTHANDLER_DEFINE(name, func, arg, priority)                  \
 146         static eventhandler_tag name ## _tag;                           \
 147         static void name ## _evh_init(void *ctx)                        \
 148         {                                                               \
 149                 name ## _tag = EVENTHANDLER_REGISTER(name, func, ctx,   \
 150                     priority);                                          \
 151         }                                                               \
 152         SYSINIT(name ## _evh_init, SI_SUB_CONFIGURE, SI_ORDER_ANY,      \
 153             name ## _evh_init, arg);                                    \
 154         struct __hack
 155
 156 #define EVENTHANDLER_INVOKE(name, ...)                                  \
 157 do {                                                                    \
 158         struct eventhandler_list *_el;                                  \
 159                                                                         \
 160         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 161                 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);       \
 162 } while (0)
 163
 164 #define EVENTHANDLER_REGISTER(name, func, arg, priority)                \
 165         eventhandler_register(NULL, #name, func, arg, priority)
 166
 167 #define EVENTHANDLER_DEREGISTER(name, tag)                              \
 168 do {                                                                    \
 169         struct eventhandler_list *_el;                                  \
 170                                                                         \
 171         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 172                 eventhandler_deregister(_el, tag);                      \
 173 } while(0)
 174
 175 #define EVENTHANDLER_DEREGISTER_NOWAIT(name, tag)                       \
 176 do {                                                                    \
 177         struct eventhandler_list *_el;                                  \
 178                                                                         \
 179         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 180                 eventhandler_deregister_nowait(_el, tag);               \
 181 } while(0)
 182
 183 eventhandler_tag eventhandler_register(struct eventhandler_list *list,
 184             const char *name, void *func, void *arg, int priority);
 185 void    eventhandler_deregister(struct eventhandler_list *list,
 186             eventhandler_tag tag);
 187 void    eventhandler_deregister_nowait(struct eventhandler_list *list,
 188             eventhandler_tag tag);
 189 struct eventhandler_list *eventhandler_find_list(const char *name);
 190 void    eventhandler_prune_list(struct eventhandler_list *list);
 191 struct eventhandler_list *eventhandler_create_list(const char *name);
 192
 193 #ifdef VIMAGE
 194 typedef void (*vimage_iterator_func_t)(void *, ...);
 195
 196 eventhandler_tag vimage_eventhandler_register(struct eventhandler_list *list,
 197             const char *name, void *func, void *arg, int priority,
 198             vimage_iterator_func_t);
 199 #endif
 200
 201 /*
 202  * Standard system event queues.
 203  */
 204
 205 /* Generic priority levels */
 206 #define EVENTHANDLER_PRI_FIRST  0
 207 #define EVENTHANDLER_PRI_ANY    10000
 208 #define EVENTHANDLER_PRI_LAST   20000
 209
 210 /* Shutdown events */
 211 typedef void (*shutdown_fn)(void *, int);
 212
 213 #define SHUTDOWN_PRI_FIRST      EVENTHANDLER_PRI_FIRST
 214 #define SHUTDOWN_PRI_DEFAULT    EVENTHANDLER_PRI_ANY
 215 #define SHUTDOWN_PRI_LAST       EVENTHANDLER_PRI_LAST
 216
 217 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn);   /* before fs sync */
 218 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn);  /* after fs sync */
 219 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
 220
 221 /* Power state change events */
 222 typedef void (*power_change_fn)(void *);
 223 EVENTHANDLER_DECLARE(power_resume, power_change_fn);
 224 EVENTHANDLER_DECLARE(power_suspend, power_change_fn);
 225 EVENTHANDLER_DECLARE(power_suspend_early, power_change_fn);
 226
 227 /* Low memory event */
 228 typedef void (*vm_lowmem_handler_t)(void *, int);
 229 #define LOWMEM_PRI_DEFAULT      EVENTHANDLER_PRI_FIRST
 230 EVENTHANDLER_DECLARE(vm_lowmem, vm_lowmem_handler_t);
 231
 232 /* Root mounted event */
 233 typedef void (*mountroot_handler_t)(void *);
 234 EVENTHANDLER_DECLARE(mountroot, mountroot_handler_t);
 235
 236 /* File system mount events */
 237 struct mount;
 238 struct vnode;
 239 struct thread;
 240 typedef void (*vfs_mounted_notify_fn)(void *, struct mount *, struct vnode *,
 241     struct thread *);
 242 typedef void (*vfs_unmounted_notify_fn)(void *, struct mount *,
 243     struct thread *);
 244 EVENTHANDLER_DECLARE(vfs_mounted, vfs_mounted_notify_fn);
 245 EVENTHANDLER_DECLARE(vfs_unmounted, vfs_unmounted_notify_fn);
 246
 247 /*
 248  * Process events
 249  * process_fork and exit handlers are called without Giant.
 250  * exec handlers are called with Giant, but that is by accident.
 251  */
 252 struct proc;
 253 struct image_params;
 254
 255 typedef void (*exitlist_fn)(void *, struct proc *);
 256 typedef void (*forklist_fn)(void *, struct proc *, struct proc *, int);
 257 typedef void (*execlist_fn)(void *, struct proc *, struct image_params *);
 258 typedef void (*proc_ctor_fn)(void *, struct proc *);
 259 typedef void (*proc_dtor_fn)(void *, struct proc *);
 260 typedef void (*proc_init_fn)(void *, struct proc *);
 261 typedef void (*proc_fini_fn)(void *, struct proc *);
 262 EVENTHANDLER_DECLARE(process_ctor, proc_ctor_fn);
 263 EVENTHANDLER_DECLARE(process_dtor, proc_dtor_fn);
 264 EVENTHANDLER_DECLARE(process_init, proc_init_fn);
 265 EVENTHANDLER_DECLARE(process_fini, proc_fini_fn);
 266 EVENTHANDLER_DECLARE(process_exit, exitlist_fn);
 267 EVENTHANDLER_DECLARE(process_fork, forklist_fn);
 268 EVENTHANDLER_DECLARE(process_exec, execlist_fn);
 269
 270 /*
 271  * application dump event
 272  */
 273 typedef void (*app_coredump_start_fn)(void *, struct thread *, char *name);
 274 typedef void (*app_coredump_progress_fn)(void *, struct thread *td, int byte_count);
 275 typedef void (*app_coredump_finish_fn)(void *, struct thread *td);
 276 typedef void (*app_coredump_error_fn)(void *, struct thread *td, char *msg, ...);
 277
 278 EVENTHANDLER_DECLARE(app_coredump_start, app_coredump_start_fn);
 279 EVENTHANDLER_DECLARE(app_coredump_progress, app_coredump_progress_fn);
 280 EVENTHANDLER_DECLARE(app_coredump_finish, app_coredump_finish_fn);
 281 EVENTHANDLER_DECLARE(app_coredump_error, app_coredump_error_fn);
 282
 283 typedef void (*thread_ctor_fn)(void *, struct thread *);
 284 typedef void (*thread_dtor_fn)(void *, struct thread *);
 285 typedef void (*thread_fini_fn)(void *, struct thread *);
 286 typedef void (*thread_init_fn)(void *, struct thread *);
 287 EVENTHANDLER_DECLARE(thread_ctor, thread_ctor_fn);
 288 EVENTHANDLER_DECLARE(thread_dtor, thread_dtor_fn);
 289 EVENTHANDLER_DECLARE(thread_init, thread_init_fn);
 290 EVENTHANDLER_DECLARE(thread_fini, thread_fini_fn);
 291
 292 typedef void (*uma_zone_chfn)(void *);
 293 EVENTHANDLER_DECLARE(nmbclusters_change, uma_zone_chfn);
 294 EVENTHANDLER_DECLARE(nmbufs_change, uma_zone_chfn);
 295 EVENTHANDLER_DECLARE(maxsockets_change, uma_zone_chfn);
 296
 297 /* Kernel linker file load and unload events */
 298 struct linker_file;
 299 typedef void (*kld_load_fn)(void *, struct linker_file *);
 300 typedef void (*kld_unload_fn)(void *, const char *, caddr_t, size_t);
 301 typedef void (*kld_unload_try_fn)(void *, struct linker_file *, int *);
 302 EVENTHANDLER_DECLARE(kld_load, kld_load_fn);
 303 EVENTHANDLER_DECLARE(kld_unload, kld_unload_fn);
 304 EVENTHANDLER_DECLARE(kld_unload_try, kld_unload_try_fn);
 305
 306 /* Generic graphics framebuffer interface */
 307 struct fb_info;
 308 typedef void (*register_framebuffer_fn)(void *, struct fb_info *);
 309 typedef void (*unregister_framebuffer_fn)(void *, struct fb_info *);
 310 EVENTHANDLER_DECLARE(register_framebuffer, register_framebuffer_fn);
 311 EVENTHANDLER_DECLARE(unregister_framebuffer, unregister_framebuffer_fn);
 312
 313 /* Veto ada attachment */
 314 struct cam_path;
 315 struct ata_params;
 316 typedef void (*ada_probe_veto_fn)(void *, struct cam_path *,
 317     struct ata_params *, int *);
 318 EVENTHANDLER_DECLARE(ada_probe_veto, ada_probe_veto_fn);
 319
 320 /* Swap device events */
 321 struct swdevt;
 322 typedef void (*swapon_fn)(void *, struct swdevt *);
 323 typedef void (*swapoff_fn)(void *, struct swdevt *);
 324 EVENTHANDLER_DECLARE(swapon, swapon_fn);
 325 EVENTHANDLER_DECLARE(swapoff, swapoff_fn);
 326
 327 /* newbus device events */
 328 enum evhdev_detach {
 329         EVHDEV_DETACH_BEGIN,    /* Before detach() is called */
 330         EVHDEV_DETACH_COMPLETE, /* After detach() returns 0 */
 331         EVHDEV_DETACH_FAILED    /* After detach() returns err */
 332 };
 333 typedef void (*device_attach_fn)(void *, device_t);
 334 typedef void (*device_detach_fn)(void *, device_t, enum evhdev_detach);
 335 EVENTHANDLER_DECLARE(device_attach, device_attach_fn);
 336 EVENTHANDLER_DECLARE(device_detach, device_detach_fn);
 337
 338 #endif /* _SYS_EVENTHANDLER_H_ */