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;
  57 #define EHL_INITTED     (1<<0)
  58         u_int                           el_runcount;
  59         struct mtx                      el_lock;
  60         TAILQ_ENTRY(eventhandler_list)  el_link;
  61         TAILQ_HEAD(,eventhandler_entry) el_entries;
  62 };
  63
  64 typedef struct eventhandler_entry       *eventhandler_tag;
  65
  66 #define EHL_LOCK(p)             mtx_lock(&(p)->el_lock)
  67 #define EHL_UNLOCK(p)           mtx_unlock(&(p)->el_lock)
  68 #define EHL_LOCK_ASSERT(p, x)   mtx_assert(&(p)->el_lock, x)
  69
  70 /*
  71  * Macro to invoke the handlers for a given event.
  72  */
  73 #define _EVENTHANDLER_INVOKE(name, list, ...) do {                      \
  74         struct eventhandler_entry *_ep;                                 \
  75         struct eventhandler_entry_ ## name *_t;                         \
  76                                                                         \
  77         KASSERT((list)->el_flags & EHL_INITTED,                         \
  78            ("eventhandler_invoke: running non-inited list"));           \
  79         EHL_LOCK_ASSERT((list), MA_OWNED);                              \
  80         (list)->el_runcount++;                                          \
  81         KASSERT((list)->el_runcount > 0,                                \
  82             ("eventhandler_invoke: runcount overflow"));                \
  83         CTR0(KTR_EVH, "eventhandler_invoke(\"" __STRING(name) "\")");   \
  84         TAILQ_FOREACH(_ep, &((list)->el_entries), ee_link) {            \
  85                 if (_ep->ee_priority != EHE_DEAD_PRIORITY) {            \
  86                         EHL_UNLOCK((list));                             \
  87                         _t = (struct eventhandler_entry_ ## name *)_ep; \
  88                         CTR1(KTR_EVH, "eventhandler_invoke: executing %p", \
  89                             (void *)_t->eh_func);                       \
  90                         _t->eh_func(_ep->ee_arg , ## __VA_ARGS__);      \
  91                         EHL_LOCK((list));                               \
  92                 }                                                       \
  93         }                                                               \
  94         KASSERT((list)->el_runcount > 0,                                \
  95             ("eventhandler_invoke: runcount underflow"));               \
  96         (list)->el_runcount--;                                          \
  97         if ((list)->el_runcount == 0)                                   \
  98                 eventhandler_prune_list(list);                          \
  99         EHL_UNLOCK((list));                                             \
 100 } while (0)
 101
 102 /*
 103  * Slow handlers are entirely dynamic; lists are created
 104  * when entries are added to them, and thus have no concept of "owner",
 105  *
 106  * Slow handlers need to be declared, but do not need to be defined. The
 107  * declaration must be in scope wherever the handler is to be invoked.
 108  */
 109 #define EVENTHANDLER_DECLARE(name, type)                                \
 110 struct eventhandler_entry_ ## name                                      \
 111 {                                                                       \
 112         struct eventhandler_entry       ee;                             \
 113         type                            eh_func;                        \
 114 };                                                                      \
 115 struct __hack
 116
 117 #define EVENTHANDLER_DEFINE(name, func, arg, priority)                  \
 118         static eventhandler_tag name ## _tag;                           \
 119         static void name ## _evh_init(void *ctx)                        \
 120         {                                                               \
 121                 name ## _tag = EVENTHANDLER_REGISTER(name, func, ctx,   \
 122                     priority);                                          \
 123         }                                                               \
 124         SYSINIT(name ## _evh_init, SI_SUB_CONFIGURE, SI_ORDER_ANY,      \
 125             name ## _evh_init, arg);                                    \
 126         struct __hack
 127
 128 #define EVENTHANDLER_INVOKE(name, ...)                                  \
 129 do {                                                                    \
 130         struct eventhandler_list *_el;                                  \
 131                                                                         \
 132         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 133                 _EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);       \
 134 } while (0)
 135
 136 #define EVENTHANDLER_REGISTER(name, func, arg, priority)                \
 137         eventhandler_register(NULL, #name, func, arg, priority)
 138
 139 #define EVENTHANDLER_DEREGISTER(name, tag)                              \
 140 do {                                                                    \
 141         struct eventhandler_list *_el;                                  \
 142                                                                         \
 143         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 144                 eventhandler_deregister(_el, tag);                      \
 145 } while(0)
 146
 147 #define EVENTHANDLER_DEREGISTER_NOWAIT(name, tag)                       \
 148 do {                                                                    \
 149         struct eventhandler_list *_el;                                  \
 150                                                                         \
 151         if ((_el = eventhandler_find_list(#name)) != NULL)              \
 152                 eventhandler_deregister_nowait(_el, tag);               \
 153 } while(0)
 154
 155 eventhandler_tag eventhandler_register(struct eventhandler_list *list,
 156             const char *name, void *func, void *arg, int priority);
 157 void    eventhandler_deregister(struct eventhandler_list *list,
 158             eventhandler_tag tag);
 159 void    eventhandler_deregister_nowait(struct eventhandler_list *list,
 160             eventhandler_tag tag);
 161 struct eventhandler_list *eventhandler_find_list(const char *name);
 162 void    eventhandler_prune_list(struct eventhandler_list *list);
 163
 164 #ifdef VIMAGE
 165 typedef void (*vimage_iterator_func_t)(void *, ...);
 166
 167 eventhandler_tag vimage_eventhandler_register(struct eventhandler_list *list,
 168             const char *name, void *func, void *arg, int priority,
 169             vimage_iterator_func_t);
 170 #endif
 171
 172 /*
 173  * Standard system event queues.
 174  */
 175
 176 /* Generic priority levels */
 177 #define EVENTHANDLER_PRI_FIRST  0
 178 #define EVENTHANDLER_PRI_ANY    10000
 179 #define EVENTHANDLER_PRI_LAST   20000
 180
 181 /* Shutdown events */
 182 typedef void (*shutdown_fn)(void *, int);
 183
 184 #define SHUTDOWN_PRI_FIRST      EVENTHANDLER_PRI_FIRST
 185 #define SHUTDOWN_PRI_DEFAULT    EVENTHANDLER_PRI_ANY
 186 #define SHUTDOWN_PRI_LAST       EVENTHANDLER_PRI_LAST
 187
 188 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn);   /* before fs sync */
 189 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn);  /* after fs sync */
 190 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
 191
 192 /* Power state change events */
 193 typedef void (*power_change_fn)(void *);
 194 EVENTHANDLER_DECLARE(power_resume, power_change_fn);
 195 EVENTHANDLER_DECLARE(power_suspend, power_change_fn);
 196 EVENTHANDLER_DECLARE(power_suspend_early, power_change_fn);
 197
 198 /* Low memory event */
 199 typedef void (*vm_lowmem_handler_t)(void *, int);
 200 #define LOWMEM_PRI_DEFAULT      EVENTHANDLER_PRI_FIRST
 201 EVENTHANDLER_DECLARE(vm_lowmem, vm_lowmem_handler_t);
 202
 203 /* Root mounted event */
 204 typedef void (*mountroot_handler_t)(void *);
 205 EVENTHANDLER_DECLARE(mountroot, mountroot_handler_t);
 206
 207 /* File system mount events */
 208 struct mount;
 209 struct vnode;
 210 struct thread;
 211 typedef void (*vfs_mounted_notify_fn)(void *, struct mount *, struct vnode *,
 212     struct thread *);
 213 typedef void (*vfs_unmounted_notify_fn)(void *, struct mount *,
 214     struct thread *);
 215 EVENTHANDLER_DECLARE(vfs_mounted, vfs_mounted_notify_fn);
 216 EVENTHANDLER_DECLARE(vfs_unmounted, vfs_unmounted_notify_fn);
 217
 218 /*
 219  * Process events
 220  * process_fork and exit handlers are called without Giant.
 221  * exec handlers are called with Giant, but that is by accident.
 222  */
 223 struct proc;
 224 struct image_params;
 225
 226 typedef void (*exitlist_fn)(void *, struct proc *);
 227 typedef void (*forklist_fn)(void *, struct proc *, struct proc *, int);
 228 typedef void (*execlist_fn)(void *, struct proc *, struct image_params *);
 229 typedef void (*proc_ctor_fn)(void *, struct proc *);
 230 typedef void (*proc_dtor_fn)(void *, struct proc *);
 231 typedef void (*proc_init_fn)(void *, struct proc *);
 232 typedef void (*proc_fini_fn)(void *, struct proc *);
 233 EVENTHANDLER_DECLARE(process_ctor, proc_ctor_fn);
 234 EVENTHANDLER_DECLARE(process_dtor, proc_dtor_fn);
 235 EVENTHANDLER_DECLARE(process_init, proc_init_fn);
 236 EVENTHANDLER_DECLARE(process_fini, proc_fini_fn);
 237 EVENTHANDLER_DECLARE(process_exit, exitlist_fn);
 238 EVENTHANDLER_DECLARE(process_fork, forklist_fn);
 239 EVENTHANDLER_DECLARE(process_exec, execlist_fn);
 240
 241 /*
 242  * application dump event
 243  */
 244 typedef void (*app_coredump_start_fn)(void *, struct thread *, char *name);
 245 typedef void (*app_coredump_progress_fn)(void *, struct thread *td, int byte_count);
 246 typedef void (*app_coredump_finish_fn)(void *, struct thread *td);
 247 typedef void (*app_coredump_error_fn)(void *, struct thread *td, char *msg, ...);
 248
 249 EVENTHANDLER_DECLARE(app_coredump_start, app_coredump_start_fn);
 250 EVENTHANDLER_DECLARE(app_coredump_progress, app_coredump_progress_fn);
 251 EVENTHANDLER_DECLARE(app_coredump_finish, app_coredump_finish_fn);
 252 EVENTHANDLER_DECLARE(app_coredump_error, app_coredump_error_fn);
 253
 254 typedef void (*thread_ctor_fn)(void *, struct thread *);
 255 typedef void (*thread_dtor_fn)(void *, struct thread *);
 256 typedef void (*thread_fini_fn)(void *, struct thread *);
 257 typedef void (*thread_init_fn)(void *, struct thread *);
 258 EVENTHANDLER_DECLARE(thread_ctor, thread_ctor_fn);
 259 EVENTHANDLER_DECLARE(thread_dtor, thread_dtor_fn);
 260 EVENTHANDLER_DECLARE(thread_init, thread_init_fn);
 261 EVENTHANDLER_DECLARE(thread_fini, thread_fini_fn);
 262
 263 typedef void (*uma_zone_chfn)(void *);
 264 EVENTHANDLER_DECLARE(nmbclusters_change, uma_zone_chfn);
 265 EVENTHANDLER_DECLARE(nmbufs_change, uma_zone_chfn);
 266 EVENTHANDLER_DECLARE(maxsockets_change, uma_zone_chfn);
 267
 268 /* Kernel linker file load and unload events */
 269 struct linker_file;
 270 typedef void (*kld_load_fn)(void *, struct linker_file *);
 271 typedef void (*kld_unload_fn)(void *, const char *, caddr_t, size_t);
 272 typedef void (*kld_unload_try_fn)(void *, struct linker_file *, int *);
 273 EVENTHANDLER_DECLARE(kld_load, kld_load_fn);
 274 EVENTHANDLER_DECLARE(kld_unload, kld_unload_fn);
 275 EVENTHANDLER_DECLARE(kld_unload_try, kld_unload_try_fn);
 276
 277 /* Generic graphics framebuffer interface */
 278 struct fb_info;
 279 typedef void (*register_framebuffer_fn)(void *, struct fb_info *);
 280 typedef void (*unregister_framebuffer_fn)(void *, struct fb_info *);
 281 EVENTHANDLER_DECLARE(register_framebuffer, register_framebuffer_fn);
 282 EVENTHANDLER_DECLARE(unregister_framebuffer, unregister_framebuffer_fn);
 283
 284 /* Veto ada attachment */
 285 struct cam_path;
 286 struct ata_params;
 287 typedef void (*ada_probe_veto_fn)(void *, struct cam_path *,
 288     struct ata_params *, int *);
 289 EVENTHANDLER_DECLARE(ada_probe_veto, ada_probe_veto_fn);
 290
 291 /* newbus device events */
 292 enum evhdev_detach {
 293         EVHDEV_DETACH_BEGIN,    /* Before detach() is called */
 294         EVHDEV_DETACH_COMPLETE, /* After detach() returns 0 */
 295         EVHDEV_DETACH_FAILED    /* After detach() returns err */
 296 };
 297 typedef void (*device_attach_fn)(void *, device_t);
 298 typedef void (*device_detach_fn)(void *, device_t, enum evhdev_detach);
 299 EVENTHANDLER_DECLARE(device_attach, device_attach_fn);
 300 EVENTHANDLER_DECLARE(device_detach, device_detach_fn);
 301
 302 #endif /* _SYS_EVENTHANDLER_H_ */