xref: /freebsd/sys/sys/eventhandler.h (revision 1323ec57)
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 /* Shutdown events */
188 typedef void (*shutdown_fn)(void *, int);
189 
190 #define	SHUTDOWN_PRI_FIRST	EVENTHANDLER_PRI_FIRST
191 #define	SHUTDOWN_PRI_DEFAULT	EVENTHANDLER_PRI_ANY
192 #define	SHUTDOWN_PRI_LAST	EVENTHANDLER_PRI_LAST
193 
194 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn);	/* before fs sync */
195 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn);	/* after fs sync */
196 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
197 
198 /* Power state change events */
199 typedef void (*power_change_fn)(void *);
200 EVENTHANDLER_DECLARE(power_resume, power_change_fn);
201 EVENTHANDLER_DECLARE(power_suspend, power_change_fn);
202 EVENTHANDLER_DECLARE(power_suspend_early, power_change_fn);
203 
204 /* Low memory event */
205 typedef void (*vm_lowmem_handler_t)(void *, int);
206 #define	LOWMEM_PRI_DEFAULT	EVENTHANDLER_PRI_FIRST
207 EVENTHANDLER_DECLARE(vm_lowmem, vm_lowmem_handler_t);
208 
209 /* Root mounted event */
210 typedef void (*mountroot_handler_t)(void *);
211 EVENTHANDLER_DECLARE(mountroot, mountroot_handler_t);
212 
213 /* File system mount events */
214 struct mount;
215 struct vnode;
216 struct thread;
217 typedef void (*vfs_mounted_notify_fn)(void *, struct mount *, struct vnode *,
218     struct thread *);
219 typedef void (*vfs_unmounted_notify_fn)(void *, struct mount *,
220     struct thread *);
221 EVENTHANDLER_DECLARE(vfs_mounted, vfs_mounted_notify_fn);
222 EVENTHANDLER_DECLARE(vfs_unmounted, vfs_unmounted_notify_fn);
223 
224 /*
225  * Process events
226  * process_fork and exit handlers are called without Giant.
227  * exec handlers are called with Giant, but that is by accident.
228  */
229 struct proc;
230 struct image_params;
231 
232 typedef void (*exitlist_fn)(void *, struct proc *);
233 typedef void (*forklist_fn)(void *, struct proc *, struct proc *, int);
234 typedef void (*execlist_fn)(void *, struct proc *, struct image_params *);
235 typedef void (*proc_ctor_fn)(void *, struct proc *);
236 typedef void (*proc_dtor_fn)(void *, struct proc *);
237 typedef void (*proc_init_fn)(void *, struct proc *);
238 typedef void (*proc_fini_fn)(void *, struct proc *);
239 EVENTHANDLER_DECLARE(process_ctor, proc_ctor_fn);
240 EVENTHANDLER_DECLARE(process_dtor, proc_dtor_fn);
241 EVENTHANDLER_DECLARE(process_init, proc_init_fn);
242 EVENTHANDLER_DECLARE(process_fini, proc_fini_fn);
243 EVENTHANDLER_DECLARE(process_exit, exitlist_fn);
244 EVENTHANDLER_DECLARE(process_fork, forklist_fn);
245 EVENTHANDLER_DECLARE(process_exec, execlist_fn);
246 
247 /*
248  * application dump event
249  */
250 typedef void (*app_coredump_start_fn)(void *, struct thread *, char *name);
251 typedef void (*app_coredump_progress_fn)(void *, struct thread *td, int byte_count);
252 typedef void (*app_coredump_finish_fn)(void *, struct thread *td);
253 typedef void (*app_coredump_error_fn)(void *, struct thread *td, char *msg, ...);
254 
255 EVENTHANDLER_DECLARE(app_coredump_start, app_coredump_start_fn);
256 EVENTHANDLER_DECLARE(app_coredump_progress, app_coredump_progress_fn);
257 EVENTHANDLER_DECLARE(app_coredump_finish, app_coredump_finish_fn);
258 EVENTHANDLER_DECLARE(app_coredump_error, app_coredump_error_fn);
259 
260 typedef void (*thread_ctor_fn)(void *, struct thread *);
261 typedef void (*thread_dtor_fn)(void *, struct thread *);
262 typedef void (*thread_fini_fn)(void *, struct thread *);
263 typedef void (*thread_init_fn)(void *, struct thread *);
264 EVENTHANDLER_DECLARE(thread_ctor, thread_ctor_fn);
265 EVENTHANDLER_DECLARE(thread_dtor, thread_dtor_fn);
266 EVENTHANDLER_DECLARE(thread_init, thread_init_fn);
267 EVENTHANDLER_DECLARE(thread_fini, thread_fini_fn);
268 
269 typedef void (*uma_zone_chfn)(void *);
270 EVENTHANDLER_DECLARE(nmbclusters_change, uma_zone_chfn);
271 EVENTHANDLER_DECLARE(nmbufs_change, uma_zone_chfn);
272 EVENTHANDLER_DECLARE(maxsockets_change, uma_zone_chfn);
273 
274 /* Kernel linker file load and unload events */
275 struct linker_file;
276 typedef void (*kld_load_fn)(void *, struct linker_file *);
277 typedef void (*kld_unload_fn)(void *, const char *, caddr_t, size_t);
278 typedef void (*kld_unload_try_fn)(void *, struct linker_file *, int *);
279 EVENTHANDLER_DECLARE(kld_load, kld_load_fn);
280 EVENTHANDLER_DECLARE(kld_unload, kld_unload_fn);
281 EVENTHANDLER_DECLARE(kld_unload_try, kld_unload_try_fn);
282 
283 /* Generic graphics framebuffer interface */
284 struct fb_info;
285 typedef void (*register_framebuffer_fn)(void *, struct fb_info *);
286 typedef void (*unregister_framebuffer_fn)(void *, struct fb_info *);
287 EVENTHANDLER_DECLARE(register_framebuffer, register_framebuffer_fn);
288 EVENTHANDLER_DECLARE(unregister_framebuffer, unregister_framebuffer_fn);
289 
290 /* Veto ada attachment */
291 struct cam_path;
292 struct ata_params;
293 typedef void (*ada_probe_veto_fn)(void *, struct cam_path *,
294     struct ata_params *, int *);
295 EVENTHANDLER_DECLARE(ada_probe_veto, ada_probe_veto_fn);
296 
297 /* Swap device events */
298 struct swdevt;
299 typedef void (*swapon_fn)(void *, struct swdevt *);
300 typedef void (*swapoff_fn)(void *, struct swdevt *);
301 EVENTHANDLER_DECLARE(swapon, swapon_fn);
302 EVENTHANDLER_DECLARE(swapoff, swapoff_fn);
303 
304 /* newbus device events */
305 enum evhdev_detach {
306 	EVHDEV_DETACH_BEGIN,    /* Before detach() is called */
307 	EVHDEV_DETACH_COMPLETE, /* After detach() returns 0 */
308 	EVHDEV_DETACH_FAILED    /* After detach() returns err */
309 };
310 typedef void (*device_attach_fn)(void *, device_t);
311 typedef void (*device_detach_fn)(void *, device_t, enum evhdev_detach);
312 EVENTHANDLER_DECLARE(device_attach, device_attach_fn);
313 EVENTHANDLER_DECLARE(device_detach, device_detach_fn);
314 
315 /* Interface address addition and removal event */
316 struct ifaddr;
317 typedef void (*rt_addrmsg_fn)(void *, struct ifaddr *, int);
318 EVENTHANDLER_DECLARE(rt_addrmsg, rt_addrmsg_fn);
319 
320 #endif /* _SYS_EVENTHANDLER_H_ */
321