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/_eventhandler.h>
  35 #include <sys/lock.h>
  36 #include <sys/ktr.h>
  37 #include <sys/mutex.h>
  38 #include <sys/queue.h>
  39
  40 #ifdef VIMAGE
  41 struct eventhandler_entry_vimage {
  42         void    (* func)(void);         /* Original function registered. */
  43         void    *ee_arg;                /* Original argument registered. */
  44         void    *sparep[2];
  45 };
  46 #endif
  47
  48 struct eventhandler_list {
  49         char                            *el_name;
  50         int                             el_flags;       /* Unused. */
  51         u_int                           el_runcount;
  52         struct mtx                      el_lock;
  53         TAILQ_ENTRY(eventhandler_list)  el_link;
  54         TAILQ_HEAD(,eventhandler_entry) el_entries;
  55 };
  56
  57 #define EHL_LOCK(p)             mtx_lock(&(p)->el_lock)
  58 #define EHL_UNLOCK(p)           mtx_unlock(&(p)->el_lock)
  59 #define EHL_LOCK_ASSERT(p, x)   mtx_assert(&(p)->el_lock, x)
  60
  61 /*
  62  * Macro to invoke the handlers for a given event.
  63  */
  64 #define _EVENTHANDLER_INVOKE(name, list, ...) do {                      \
  65         struct eventhandler_entry *_ep;                                 \
  66         struct eventhandler_entry_ ## name *_t;                         \
  67                                                                         \
  68         EHL_LOCK_ASSERT((list), MA_OWNED);                              \
  69         (list)->el_runcount++;                                          \
  70         KASSERT((list)->el_runcount > 0,                                \
  71             ("eventhandler_invoke: runcount overflow"));                \
  72         CTR0(KTR_EVH, "eventhandler_invoke(\"" __STRING(name) "\")");   \
  73         TAILQ_FOREACH(_ep, &((list)->el_entries), ee_link) {            \
  74                 if (_ep->ee_priority != EHE_DEAD_PRIORITY) {            \
  75                         EHL_UNLOCK((list));                             \
  76                         _t = (struct eventhandler_entry_ ## name *)_ep; \
  77                         CTR1(KTR_EVH, "eventhandler_invoke: executing %p", \
  78                             (void *)_t->eh_func);                       \
  79                         _t->eh_func(_ep->ee_arg , ## __VA_ARGS__);      \
  80                         EHL_LOCK((list));                               \
  81                 }                                                       \
  82         }                                                               \
  83         KASSERT((list)->el_runcount > 0,                                \
  84             ("eventhandler_invoke: runcount underflow"));               \
  85         (list)->el_runcount--;                                          \
  86         if ((list)->el_runcount == 0)                                   \
  87                 eventhandler_prune_list(list);                          \
  88         EHL_UNLOCK((list));                                             \
  89 } while (0)
  90
  91 /*
  92  * You can optionally use the EVENTHANDLER_LIST and EVENTHANDLER_DIRECT macros
  93  * to pre-define a symbol for the eventhandler list. This symbol can be used by
  94  * EVENTHANDLER_DIRECT_INVOKE, which has the advantage of not needing to do a
  95  * locked search of the global list of eventhandler lists. At least
  96  * EVENTHANDLER_LIST_DEFINE must be used for EVENTHANDLER_DIRECT_INVOKE to
  97  * work. EVENTHANDLER_LIST_DECLARE is only needed if the call to
  98  * EVENTHANDLER_DIRECT_INVOKE is in a different compilation unit from
  99  * EVENTHANDLER_LIST_DEFINE. If the events are even relatively high frequency
 100  * it is suggested that you directly define a list for them.
 101  */
 102 #define EVENTHANDLER_LIST_DEFINE(name)                                  \
 103 struct eventhandler_list *_eventhandler_list_ ## name ;                 \
 104 static void _ehl_init_ ## name (void * ctx __unused)                    \
 105 {                                                                       \
 106         _eventhandler_list_ ## name = eventhandler_create_list(#name);  \
 107 }                                                                       \
 108 SYSINIT(name ## _ehl_init, SI_SUB_EVENTHANDLER, SI_ORDER_ANY,           \
 109             _ehl_init_ ## name, NULL);                                  \
 110         struct __hack
 111
 112 #define EVENTHANDLER_DIRECT_INVOKE(name, ...) do {                      \
 113         struct eventhandler_list *_el;                                  \
 114                                                                         \
 115         _el = _eventhandler_list_ ## name ;                             \
 116         if (!TAILQ_EMPTY(&_el->el_entries)) {                           \
 117                 EHL_LOCK(_el);                                          \
 118                 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);       \
 119         }                                                               \
 120 } while (0)
 121
 122 #define EVENTHANDLER_DEFINE(name, func, arg, priority)                  \
 123         static eventhandler_tag name ## _tag;                           \
 124         static void name ## _evh_init(void *ctx)                        \
 125         {                                                               \
 126                 name ## _tag = EVENTHANDLER_REGISTER(name, func, ctx,   \
 127                     priority);                                          \
 128         }                                                               \
 129         SYSINIT(name ## _evh_init, SI_SUB_CONFIGURE, SI_ORDER_ANY,      \
 130             name ## _evh_init, arg);                                    \
 131         struct __hack
 132
 133 #define EVENTHANDLER_INVOKE(name, ...)                                  \
 134 do {                                                                    \
 135         struct eventhandler_list *_el;                                  \
 136                                                                         \
 137         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 138                 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);       \
 139 } while (0)
 140
 141 #define EVENTHANDLER_REGISTER(name, func, arg, priority)                \
 142         eventhandler_register(NULL, #name, func, arg, priority)
 143
 144 #define EVENTHANDLER_DEREGISTER(name, tag)                              \
 145 do {                                                                    \
 146         struct eventhandler_list *_el;                                  \
 147                                                                         \
 148         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 149                 eventhandler_deregister(_el, tag);                      \
 150 } while (0)
 151
 152 #define EVENTHANDLER_DEREGISTER_NOWAIT(name, tag)                       \
 153 do {                                                                    \
 154         struct eventhandler_list *_el;                                  \
 155                                                                         \
 156         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 157                 eventhandler_deregister_nowait(_el, tag);               \
 158 } while (0)
 159
 160 eventhandler_tag eventhandler_register(struct eventhandler_list *list,
 161             const char *name, void *func, void *arg, int priority);
 162 void    eventhandler_deregister(struct eventhandler_list *list,
 163             eventhandler_tag tag);
 164 void    eventhandler_deregister_nowait(struct eventhandler_list *list,
 165             eventhandler_tag tag);
 166 struct eventhandler_list *eventhandler_find_list(const char *name);
 167 void    eventhandler_prune_list(struct eventhandler_list *list);
 168 struct eventhandler_list *eventhandler_create_list(const char *name);
 169
 170 #ifdef VIMAGE
 171 typedef void (*vimage_iterator_func_t)(void *, ...);
 172
 173 eventhandler_tag vimage_eventhandler_register(struct eventhandler_list *list,
 174             const char *name, void *func, void *arg, int priority,
 175             vimage_iterator_func_t);
 176 #endif
 177
 178 /*
 179  * Standard system event queues.
 180  */
 181
 182 /* Generic priority levels */
 183 #define EVENTHANDLER_PRI_FIRST  0
 184 #define EVENTHANDLER_PRI_ANY    10000
 185 #define EVENTHANDLER_PRI_LAST   20000
 186
 187 /*
 188  * Successive shutdown events invoked by kern_reboot(9).
 189  *
 190  * Handlers will receive the 'howto' value as their second argument.
 191  *
 192  * All handlers must be prepared to be executed from a panic/debugger context;
 193  * see the man page for details.
 194  */
 195 typedef void (*shutdown_fn)(void *, int);
 196
 197 #define SHUTDOWN_PRI_FIRST      EVENTHANDLER_PRI_FIRST
 198 #define SHUTDOWN_PRI_DEFAULT    EVENTHANDLER_PRI_ANY
 199 #define SHUTDOWN_PRI_LAST       EVENTHANDLER_PRI_LAST
 200
 201 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn);   /* before fs sync */
 202 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn);  /* after fs sync */
 203 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
 204
 205 /* Power state change events */
 206 typedef void (*power_change_fn)(void *);
 207 EVENTHANDLER_DECLARE(power_resume, power_change_fn);
 208 EVENTHANDLER_DECLARE(power_suspend, power_change_fn);
 209 EVENTHANDLER_DECLARE(power_suspend_early, power_change_fn);
 210
 211 /* Low memory event */
 212 typedef void (*vm_lowmem_handler_t)(void *, int);
 213 #define LOWMEM_PRI_DEFAULT      EVENTHANDLER_PRI_FIRST
 214 EVENTHANDLER_DECLARE(vm_lowmem, vm_lowmem_handler_t);
 215 /* Some of mbuf(9) zones reached maximum */
 216 EVENTHANDLER_DECLARE(mbuf_lowmem, vm_lowmem_handler_t);
 217
 218 /* Root mounted event */
 219 typedef void (*mountroot_handler_t)(void *);
 220 EVENTHANDLER_DECLARE(mountroot, mountroot_handler_t);
 221
 222 /* File system mount events */
 223 struct mount;
 224 struct vnode;
 225 struct thread;
 226 typedef void (*vfs_mounted_notify_fn)(void *, struct mount *, struct vnode *,
 227     struct thread *);
 228 typedef void (*vfs_unmounted_notify_fn)(void *, struct mount *,
 229     struct thread *);
 230 EVENTHANDLER_DECLARE(vfs_mounted, vfs_mounted_notify_fn);
 231 EVENTHANDLER_DECLARE(vfs_unmounted, vfs_unmounted_notify_fn);
 232
 233 /*
 234  * Process events
 235  * process_fork and exit handlers are called without Giant.
 236  * exec handlers are called with Giant, but that is by accident.
 237  */
 238 struct proc;
 239 struct image_params;
 240
 241 typedef void (*exitlist_fn)(void *, struct proc *);
 242 typedef void (*forklist_fn)(void *, struct proc *, struct proc *, int);
 243 typedef void (*execlist_fn)(void *, struct proc *, struct image_params *);
 244 typedef void (*proc_ctor_fn)(void *, struct proc *);
 245 typedef void (*proc_dtor_fn)(void *, struct proc *);
 246 typedef void (*proc_init_fn)(void *, struct proc *);
 247 typedef void (*proc_fini_fn)(void *, struct proc *);
 248 EVENTHANDLER_DECLARE(process_ctor, proc_ctor_fn);
 249 EVENTHANDLER_DECLARE(process_dtor, proc_dtor_fn);
 250 EVENTHANDLER_DECLARE(process_init, proc_init_fn);
 251 EVENTHANDLER_DECLARE(process_fini, proc_fini_fn);
 252 EVENTHANDLER_DECLARE(process_exit, exitlist_fn);
 253 EVENTHANDLER_DECLARE(process_fork, forklist_fn);
 254 EVENTHANDLER_DECLARE(process_exec, execlist_fn);
 255
 256 /*
 257  * application dump event
 258  */
 259 typedef void (*app_coredump_start_fn)(void *, struct thread *, char *name);
 260 typedef void (*app_coredump_progress_fn)(void *, struct thread *td, int byte_count);
 261 typedef void (*app_coredump_finish_fn)(void *, struct thread *td);
 262 typedef void (*app_coredump_error_fn)(void *, struct thread *td, char *msg, ...);
 263
 264 EVENTHANDLER_DECLARE(app_coredump_start, app_coredump_start_fn);
 265 EVENTHANDLER_DECLARE(app_coredump_progress, app_coredump_progress_fn);
 266 EVENTHANDLER_DECLARE(app_coredump_finish, app_coredump_finish_fn);
 267 EVENTHANDLER_DECLARE(app_coredump_error, app_coredump_error_fn);
 268
 269 typedef void (*thread_ctor_fn)(void *, struct thread *);
 270 typedef void (*thread_dtor_fn)(void *, struct thread *);
 271 typedef void (*thread_fini_fn)(void *, struct thread *);
 272 typedef void (*thread_init_fn)(void *, struct thread *);
 273 EVENTHANDLER_DECLARE(thread_ctor, thread_ctor_fn);
 274 EVENTHANDLER_DECLARE(thread_dtor, thread_dtor_fn);
 275 EVENTHANDLER_DECLARE(thread_init, thread_init_fn);
 276 EVENTHANDLER_DECLARE(thread_fini, thread_fini_fn);
 277
 278 typedef void (*uma_zone_chfn)(void *);
 279 EVENTHANDLER_DECLARE(nmbclusters_change, uma_zone_chfn);
 280 EVENTHANDLER_DECLARE(nmbufs_change, uma_zone_chfn);
 281 EVENTHANDLER_DECLARE(maxsockets_change, uma_zone_chfn);
 282
 283 /* Kernel linker file load and unload events */
 284 struct linker_file;
 285 typedef void (*kld_load_fn)(void *, struct linker_file *);
 286 typedef void (*kld_unload_fn)(void *, const char *, caddr_t, size_t);
 287 typedef void (*kld_unload_try_fn)(void *, struct linker_file *, int *);
 288 EVENTHANDLER_DECLARE(kld_load, kld_load_fn);
 289 EVENTHANDLER_DECLARE(kld_unload, kld_unload_fn);
 290 EVENTHANDLER_DECLARE(kld_unload_try, kld_unload_try_fn);
 291
 292 /* Generic graphics framebuffer interface */
 293 struct fb_info;
 294 typedef void (*register_framebuffer_fn)(void *, struct fb_info *);
 295 typedef void (*unregister_framebuffer_fn)(void *, struct fb_info *);
 296 EVENTHANDLER_DECLARE(register_framebuffer, register_framebuffer_fn);
 297 EVENTHANDLER_DECLARE(unregister_framebuffer, unregister_framebuffer_fn);
 298
 299 /* Veto ada attachment */
 300 struct cam_path;
 301 struct ata_params;
 302 typedef void (*ada_probe_veto_fn)(void *, struct cam_path *,
 303     struct ata_params *, int *);
 304 EVENTHANDLER_DECLARE(ada_probe_veto, ada_probe_veto_fn);
 305
 306 /* Swap device events */
 307 struct swdevt;
 308 typedef void (*swapon_fn)(void *, struct swdevt *);
 309 typedef void (*swapoff_fn)(void *, struct swdevt *);
 310 EVENTHANDLER_DECLARE(swapon, swapon_fn);
 311 EVENTHANDLER_DECLARE(swapoff, swapoff_fn);
 312
 313 /* newbus device events */
 314 enum evhdev_detach {
 315         EVHDEV_DETACH_BEGIN,    /* Before detach() is called */
 316         EVHDEV_DETACH_COMPLETE, /* After detach() returns 0 */
 317         EVHDEV_DETACH_FAILED    /* After detach() returns err */
 318 };
 319 typedef void (*device_attach_fn)(void *, device_t);
 320 typedef void (*device_detach_fn)(void *, device_t, enum evhdev_detach);
 321 typedef void (*device_nomatch_fn)(void *, device_t);
 322 EVENTHANDLER_DECLARE(device_attach, device_attach_fn);
 323 EVENTHANDLER_DECLARE(device_detach, device_detach_fn);
 324 EVENTHANDLER_DECLARE(device_nomatch, device_nomatch_fn);
 325
 326 /* Interface address addition and removal event */
 327 struct ifaddr;
 328 typedef void (*rt_addrmsg_fn)(void *, struct ifaddr *, int);
 329 EVENTHANDLER_DECLARE(rt_addrmsg, rt_addrmsg_fn);
 330
 331 #endif /* _SYS_EVENTHANDLER_H_ */