xref: /freebsd-13-stable/sys/sys/eventhandler.h (revision f8167e0404dab9ffeaca95853dd237ab7c587f82)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
29 #ifndef _SYS_EVENTHANDLER_H_
30 #define _SYS_EVENTHANDLER_H_
31 
32 #include <sys/_eventhandler.h>
33 #include <sys/lock.h>
34 #include <sys/ktr.h>
35 #include <sys/mutex.h>
36 #include <sys/queue.h>
37 
38 #ifdef VIMAGE
39 struct eventhandler_entry_vimage {
40 	void	(* func)(void);		/* Original function registered. */
41 	void	*ee_arg;		/* Original argument registered. */
42 	void	*sparep[2];
43 };
44 #endif
45 
46 struct eventhandler_list {
47 	char				*el_name;
48 	int				el_flags;	/* Unused. */
49 	u_int				el_runcount;
50 	struct mtx			el_lock;
51 	TAILQ_ENTRY(eventhandler_list)	el_link;
52 	TAILQ_HEAD(,eventhandler_entry)	el_entries;
53 };
54 
55 #define	EHL_LOCK(p)		mtx_lock(&(p)->el_lock)
56 #define	EHL_UNLOCK(p)		mtx_unlock(&(p)->el_lock)
57 #define	EHL_LOCK_ASSERT(p, x)	mtx_assert(&(p)->el_lock, x)
58 
59 /*
60  * Macro to invoke the handlers for a given event.
61  */
62 #define _EVENTHANDLER_INVOKE(name, list, ...) do {			\
63 	struct eventhandler_entry *_ep;					\
64 	struct eventhandler_entry_ ## name *_t;				\
65 									\
66 	EHL_LOCK_ASSERT((list), MA_OWNED);				\
67 	(list)->el_runcount++;						\
68 	KASSERT((list)->el_runcount > 0,				\
69 	    ("eventhandler_invoke: runcount overflow"));		\
70 	CTR0(KTR_EVH, "eventhandler_invoke(\"" __STRING(name) "\")");	\
71 	TAILQ_FOREACH(_ep, &((list)->el_entries), ee_link) {		\
72 		if (_ep->ee_priority != EHE_DEAD_PRIORITY) {		\
73 			EHL_UNLOCK((list));				\
74 			_t = (struct eventhandler_entry_ ## name *)_ep;	\
75 			CTR1(KTR_EVH, "eventhandler_invoke: executing %p", \
76  			    (void *)_t->eh_func);			\
77 			_t->eh_func(_ep->ee_arg , ## __VA_ARGS__);	\
78 			EHL_LOCK((list));				\
79 		}							\
80 	}								\
81 	KASSERT((list)->el_runcount > 0,				\
82 	    ("eventhandler_invoke: runcount underflow"));		\
83 	(list)->el_runcount--;						\
84 	if ((list)->el_runcount == 0)					\
85 		eventhandler_prune_list(list);				\
86 	EHL_UNLOCK((list));						\
87 } while (0)
88 
89 /*
90  * You can optionally use the EVENTHANDLER_LIST and EVENTHANDLER_DIRECT macros
91  * to pre-define a symbol for the eventhandler list. This symbol can be used by
92  * EVENTHANDLER_DIRECT_INVOKE, which has the advantage of not needing to do a
93  * locked search of the global list of eventhandler lists. At least
94  * EVENTHANDLER_LIST_DEFINE must be used for EVENTHANDLER_DIRECT_INVOKE to
95  * work. EVENTHANDLER_LIST_DECLARE is only needed if the call to
96  * EVENTHANDLER_DIRECT_INVOKE is in a different compilation unit from
97  * EVENTHANDLER_LIST_DEFINE. If the events are even relatively high frequency
98  * it is suggested that you directly define a list for them.
99  */
100 #define	EVENTHANDLER_LIST_DEFINE(name)					\
101 struct eventhandler_list *_eventhandler_list_ ## name ;			\
102 static void _ehl_init_ ## name (void * ctx __unused)			\
103 {									\
104 	_eventhandler_list_ ## name = eventhandler_create_list(#name);	\
105 }									\
106 SYSINIT(name ## _ehl_init, SI_SUB_EVENTHANDLER, SI_ORDER_ANY,		\
107 	    _ehl_init_ ## name, NULL);					\
108 	struct __hack
109 
110 #define	EVENTHANDLER_DIRECT_INVOKE(name, ...) do {			\
111 	struct eventhandler_list *_el;					\
112 									\
113 	_el = _eventhandler_list_ ## name ;				\
114 	if (!TAILQ_EMPTY(&_el->el_entries)) {				\
115 		EHL_LOCK(_el);						\
116 		_EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);	\
117 	}								\
118 } while (0)
119 
120 #define EVENTHANDLER_DEFINE(name, func, arg, priority)			\
121 	static eventhandler_tag name ## _tag;				\
122 	static void name ## _evh_init(void *ctx)			\
123 	{								\
124 		name ## _tag = EVENTHANDLER_REGISTER(name, func, ctx,	\
125 		    priority);						\
126 	}								\
127 	SYSINIT(name ## _evh_init, SI_SUB_CONFIGURE, SI_ORDER_ANY,	\
128 	    name ## _evh_init, arg);					\
129 	struct __hack
130 
131 #define EVENTHANDLER_INVOKE(name, ...)					\
132 do {									\
133 	struct eventhandler_list *_el;					\
134 									\
135 	if ((_el = eventhandler_find_list(#name)) != NULL) 		\
136 		_EVENTHANDLER_INVOKE(name, _el , ## __VA_ARGS__);	\
137 } while (0)
138 
139 #define EVENTHANDLER_REGISTER(name, func, arg, priority)		\
140 	eventhandler_register(NULL, #name, func, arg, priority)
141 
142 #define EVENTHANDLER_DEREGISTER(name, tag) 				\
143 do {									\
144 	struct eventhandler_list *_el;					\
145 									\
146 	if ((_el = eventhandler_find_list(#name)) != NULL)		\
147 		eventhandler_deregister(_el, tag);			\
148 } while(0)
149 
150 #define EVENTHANDLER_DEREGISTER_NOWAIT(name, tag)			\
151 do {									\
152 	struct eventhandler_list *_el;					\
153 									\
154 	if ((_el = eventhandler_find_list(#name)) != NULL)		\
155 		eventhandler_deregister_nowait(_el, tag);		\
156 } while(0)
157 
158 eventhandler_tag eventhandler_register(struct eventhandler_list *list,
159 	    const char *name, void *func, void *arg, int priority);
160 void	eventhandler_deregister(struct eventhandler_list *list,
161 	    eventhandler_tag tag);
162 void	eventhandler_deregister_nowait(struct eventhandler_list *list,
163 	    eventhandler_tag tag);
164 struct eventhandler_list *eventhandler_find_list(const char *name);
165 void	eventhandler_prune_list(struct eventhandler_list *list);
166 struct eventhandler_list *eventhandler_create_list(const char *name);
167 
168 #ifdef VIMAGE
169 typedef	void (*vimage_iterator_func_t)(void *, ...);
170 
171 eventhandler_tag vimage_eventhandler_register(struct eventhandler_list *list,
172 	    const char *name, void *func, void *arg, int priority,
173 	    vimage_iterator_func_t);
174 #endif
175 
176 /*
177  * Standard system event queues.
178  */
179 
180 /* Generic priority levels */
181 #define	EVENTHANDLER_PRI_FIRST	0
182 #define	EVENTHANDLER_PRI_ANY	10000
183 #define	EVENTHANDLER_PRI_LAST	20000
184 
185 /* Shutdown events */
186 typedef void (*shutdown_fn)(void *, int);
187 
188 #define	SHUTDOWN_PRI_FIRST	EVENTHANDLER_PRI_FIRST
189 #define	SHUTDOWN_PRI_DEFAULT	EVENTHANDLER_PRI_ANY
190 #define	SHUTDOWN_PRI_LAST	EVENTHANDLER_PRI_LAST
191 
192 EVENTHANDLER_DECLARE(shutdown_pre_sync, shutdown_fn);	/* before fs sync */
193 EVENTHANDLER_DECLARE(shutdown_post_sync, shutdown_fn);	/* after fs sync */
194 EVENTHANDLER_DECLARE(shutdown_final, shutdown_fn);
195 
196 /* Power state change events */
197 typedef void (*power_change_fn)(void *);
198 EVENTHANDLER_DECLARE(power_resume, power_change_fn);
199 EVENTHANDLER_DECLARE(power_suspend, power_change_fn);
200 EVENTHANDLER_DECLARE(power_suspend_early, power_change_fn);
201 
202 /* Low memory event */
203 typedef void (*vm_lowmem_handler_t)(void *, int);
204 #define	LOWMEM_PRI_DEFAULT	EVENTHANDLER_PRI_FIRST
205 EVENTHANDLER_DECLARE(vm_lowmem, vm_lowmem_handler_t);
206 
207 /* Root mounted event */
208 typedef void (*mountroot_handler_t)(void *);
209 EVENTHANDLER_DECLARE(mountroot, mountroot_handler_t);
210 
211 /* File system mount events */
212 struct mount;
213 struct vnode;
214 struct thread;
215 typedef void (*vfs_mounted_notify_fn)(void *, struct mount *, struct vnode *,
216     struct thread *);
217 typedef void (*vfs_unmounted_notify_fn)(void *, struct mount *,
218     struct thread *);
219 EVENTHANDLER_DECLARE(vfs_mounted, vfs_mounted_notify_fn);
220 EVENTHANDLER_DECLARE(vfs_unmounted, vfs_unmounted_notify_fn);
221 
222 /*
223  * Process events
224  * process_fork and exit handlers are called without Giant.
225  * exec handlers are called with Giant, but that is by accident.
226  */
227 struct proc;
228 struct image_params;
229 
230 typedef void (*exitlist_fn)(void *, struct proc *);
231 typedef void (*forklist_fn)(void *, struct proc *, struct proc *, int);
232 typedef void (*execlist_fn)(void *, struct proc *, struct image_params *);
233 typedef void (*proc_ctor_fn)(void *, struct proc *);
234 typedef void (*proc_dtor_fn)(void *, struct proc *);
235 typedef void (*proc_init_fn)(void *, struct proc *);
236 typedef void (*proc_fini_fn)(void *, struct proc *);
237 EVENTHANDLER_DECLARE(process_ctor, proc_ctor_fn);
238 EVENTHANDLER_DECLARE(process_dtor, proc_dtor_fn);
239 EVENTHANDLER_DECLARE(process_init, proc_init_fn);
240 EVENTHANDLER_DECLARE(process_fini, proc_fini_fn);
241 EVENTHANDLER_DECLARE(process_exit, exitlist_fn);
242 EVENTHANDLER_DECLARE(process_fork, forklist_fn);
243 EVENTHANDLER_DECLARE(process_exec, execlist_fn);
244 
245 /*
246  * application dump event
247  */
248 typedef void (*app_coredump_start_fn)(void *, struct thread *, char *name);
249 typedef void (*app_coredump_progress_fn)(void *, struct thread *td, int byte_count);
250 typedef void (*app_coredump_finish_fn)(void *, struct thread *td);
251 typedef void (*app_coredump_error_fn)(void *, struct thread *td, char *msg, ...);
252 
253 EVENTHANDLER_DECLARE(app_coredump_start, app_coredump_start_fn);
254 EVENTHANDLER_DECLARE(app_coredump_progress, app_coredump_progress_fn);
255 EVENTHANDLER_DECLARE(app_coredump_finish, app_coredump_finish_fn);
256 EVENTHANDLER_DECLARE(app_coredump_error, app_coredump_error_fn);
257 
258 typedef void (*thread_ctor_fn)(void *, struct thread *);
259 typedef void (*thread_dtor_fn)(void *, struct thread *);
260 typedef void (*thread_fini_fn)(void *, struct thread *);
261 typedef void (*thread_init_fn)(void *, struct thread *);
262 EVENTHANDLER_DECLARE(thread_ctor, thread_ctor_fn);
263 EVENTHANDLER_DECLARE(thread_dtor, thread_dtor_fn);
264 EVENTHANDLER_DECLARE(thread_init, thread_init_fn);
265 EVENTHANDLER_DECLARE(thread_fini, thread_fini_fn);
266 
267 typedef void (*uma_zone_chfn)(void *);
268 EVENTHANDLER_DECLARE(nmbclusters_change, uma_zone_chfn);
269 EVENTHANDLER_DECLARE(nmbufs_change, uma_zone_chfn);
270 EVENTHANDLER_DECLARE(maxsockets_change, uma_zone_chfn);
271 
272 /* Kernel linker file load and unload events */
273 struct linker_file;
274 typedef void (*kld_load_fn)(void *, struct linker_file *);
275 typedef void (*kld_unload_fn)(void *, const char *, caddr_t, size_t);
276 typedef void (*kld_unload_try_fn)(void *, struct linker_file *, int *);
277 EVENTHANDLER_DECLARE(kld_load, kld_load_fn);
278 EVENTHANDLER_DECLARE(kld_unload, kld_unload_fn);
279 EVENTHANDLER_DECLARE(kld_unload_try, kld_unload_try_fn);
280 
281 /* Generic graphics framebuffer interface */
282 struct fb_info;
283 typedef void (*register_framebuffer_fn)(void *, struct fb_info *);
284 typedef void (*unregister_framebuffer_fn)(void *, struct fb_info *);
285 EVENTHANDLER_DECLARE(register_framebuffer, register_framebuffer_fn);
286 EVENTHANDLER_DECLARE(unregister_framebuffer, unregister_framebuffer_fn);
287 
288 /* Veto ada attachment */
289 struct cam_path;
290 struct ata_params;
291 typedef void (*ada_probe_veto_fn)(void *, struct cam_path *,
292     struct ata_params *, int *);
293 EVENTHANDLER_DECLARE(ada_probe_veto, ada_probe_veto_fn);
294 
295 /* Swap device events */
296 struct swdevt;
297 typedef void (*swapon_fn)(void *, struct swdevt *);
298 typedef void (*swapoff_fn)(void *, struct swdevt *);
299 EVENTHANDLER_DECLARE(swapon, swapon_fn);
300 EVENTHANDLER_DECLARE(swapoff, swapoff_fn);
301 
302 /* newbus device events */
303 enum evhdev_detach {
304 	EVHDEV_DETACH_BEGIN,    /* Before detach() is called */
305 	EVHDEV_DETACH_COMPLETE, /* After detach() returns 0 */
306 	EVHDEV_DETACH_FAILED    /* After detach() returns err */
307 };
308 typedef void (*device_attach_fn)(void *, device_t);
309 typedef void (*device_detach_fn)(void *, device_t, enum evhdev_detach);
310 EVENTHANDLER_DECLARE(device_attach, device_attach_fn);
311 EVENTHANDLER_DECLARE(device_detach, device_detach_fn);
312 
313 /* Interface address addition and removal event */
314 struct ifaddr;
315 typedef void (*rt_addrmsg_fn)(void *, struct ifaddr *, int);
316 EVENTHANDLER_DECLARE(rt_addrmsg, rt_addrmsg_fn);
317 
318 #endif /* _SYS_EVENTHANDLER_H_ */
319