xref: /freebsd/sys/kern/subr_autoconf.c (revision 7c1b51d6dc2e165ae7333373513b080f17cf79bd)
1 /*-
2  * Copyright (c) 1992, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This software was developed by the Computer Systems Engineering group
6  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
7  * contributed to Berkeley.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)subr_autoconf.c	8.1 (Berkeley) 6/10/93
34  *
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "opt_ddb.h"
41 
42 #include <sys/param.h>
43 #include <sys/kernel.h>
44 #include <sys/linker.h>
45 #include <sys/lock.h>
46 #include <sys/malloc.h>
47 #include <sys/mutex.h>
48 #include <sys/systm.h>
49 
50 /*
51  * Autoconfiguration subroutines.
52  */
53 
54 /*
55  * "Interrupt driven config" functions.
56  */
57 static TAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
58 	TAILQ_HEAD_INITIALIZER(intr_config_hook_list);
59 static struct intr_config_hook *next_to_notify;
60 static struct mtx intr_config_hook_lock;
61 MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF);
62 
63 /* ARGSUSED */
64 static void run_interrupt_driven_config_hooks(void);
65 
66 /*
67  * Private data and a shim function for implementing config_interhook_oneshot().
68  */
69 struct oneshot_config_hook {
70 	struct intr_config_hook
71 			och_hook;		/* Must be first */
72 	ich_func_t	och_func;
73 	void		*och_arg;
74 };
75 
76 static void
77 config_intrhook_oneshot_func(void *arg)
78 {
79 	struct oneshot_config_hook *ohook;
80 
81 	ohook = arg;
82 	ohook->och_func(ohook->och_arg);
83 	config_intrhook_disestablish(&ohook->och_hook);
84 	free(ohook, M_DEVBUF);
85 }
86 
87 /*
88  * If we wait too long for an interrupt-driven config hook to return, print
89  * a diagnostic.
90  */
91 #define	WARNING_INTERVAL_SECS	60
92 static void
93 run_interrupt_driven_config_hooks_warning(int warned)
94 {
95 	struct intr_config_hook *hook_entry;
96 	char namebuf[64];
97 	long offset;
98 
99 	if (warned < 6) {
100 		printf("run_interrupt_driven_hooks: still waiting after %d "
101 		    "seconds for", warned * WARNING_INTERVAL_SECS);
102 		TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
103 			if (linker_search_symbol_name(
104 			    (caddr_t)hook_entry->ich_func, namebuf,
105 			    sizeof(namebuf), &offset) == 0)
106 				printf(" %s", namebuf);
107 			else
108 				printf(" %p", hook_entry->ich_func);
109 		}
110 		printf("\n");
111 	}
112 	KASSERT(warned < 6,
113 	    ("run_interrupt_driven_config_hooks: waited too long"));
114 }
115 
116 static void
117 run_interrupt_driven_config_hooks()
118 {
119 	static int running;
120 	struct intr_config_hook *hook_entry;
121 
122 	mtx_lock(&intr_config_hook_lock);
123 
124 	/*
125 	 * If hook processing is already active, any newly
126 	 * registered hooks will eventually be notified.
127 	 * Let the currently running session issue these
128 	 * notifications.
129 	 */
130 	if (running != 0) {
131 		mtx_unlock(&intr_config_hook_lock);
132 		return;
133 	}
134 	running = 1;
135 
136 	while (next_to_notify != NULL) {
137 		hook_entry = next_to_notify;
138 		next_to_notify = TAILQ_NEXT(hook_entry, ich_links);
139 		mtx_unlock(&intr_config_hook_lock);
140 		(*hook_entry->ich_func)(hook_entry->ich_arg);
141 		mtx_lock(&intr_config_hook_lock);
142 	}
143 
144 	running = 0;
145 	mtx_unlock(&intr_config_hook_lock);
146 }
147 
148 static void
149 boot_run_interrupt_driven_config_hooks(void *dummy)
150 {
151 	int warned;
152 
153 	run_interrupt_driven_config_hooks();
154 
155 	/* Block boot processing until all hooks are disestablished. */
156 	mtx_lock(&intr_config_hook_lock);
157 	warned = 0;
158 	while (!TAILQ_EMPTY(&intr_config_hook_list)) {
159 		if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
160 		    0, "conifhk", WARNING_INTERVAL_SECS * hz) ==
161 		    EWOULDBLOCK) {
162 			mtx_unlock(&intr_config_hook_lock);
163 			warned++;
164 			run_interrupt_driven_config_hooks_warning(warned);
165 			mtx_lock(&intr_config_hook_lock);
166 		}
167 	}
168 	mtx_unlock(&intr_config_hook_lock);
169 }
170 
171 SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
172 	boot_run_interrupt_driven_config_hooks, NULL);
173 
174 /*
175  * Register a hook that will be called after "cold"
176  * autoconfiguration is complete and interrupts can
177  * be used to complete initialization.
178  */
179 int
180 config_intrhook_establish(struct intr_config_hook *hook)
181 {
182 	struct intr_config_hook *hook_entry;
183 
184 	mtx_lock(&intr_config_hook_lock);
185 	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
186 		if (hook_entry == hook)
187 			break;
188 	if (hook_entry != NULL) {
189 		mtx_unlock(&intr_config_hook_lock);
190 		printf("config_intrhook_establish: establishing an "
191 		       "already established hook.\n");
192 		return (1);
193 	}
194 	TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
195 	if (next_to_notify == NULL)
196 		next_to_notify = hook;
197 	mtx_unlock(&intr_config_hook_lock);
198 	if (cold == 0)
199 		/*
200 		 * XXX Call from a task since not all drivers expect
201 		 *     to be re-entered at the time a hook is established.
202 		 */
203 		/* XXX Sufficient for modules loaded after initial config??? */
204 		run_interrupt_driven_config_hooks();
205 	return (0);
206 }
207 
208 /*
209  * Register a hook function that is automatically unregistered after it runs.
210  */
211 void
212 config_intrhook_oneshot(ich_func_t func, void *arg)
213 {
214 	struct oneshot_config_hook *ohook;
215 
216 	ohook = malloc(sizeof(*ohook), M_DEVBUF, M_WAITOK);
217 	ohook->och_func = func;
218 	ohook->och_arg  = arg;
219 	ohook->och_hook.ich_func = config_intrhook_oneshot_func;
220 	ohook->och_hook.ich_arg  = ohook;
221 	config_intrhook_establish(&ohook->och_hook);
222 }
223 
224 void
225 config_intrhook_disestablish(struct intr_config_hook *hook)
226 {
227 	struct intr_config_hook *hook_entry;
228 
229 	mtx_lock(&intr_config_hook_lock);
230 	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
231 		if (hook_entry == hook)
232 			break;
233 	if (hook_entry == NULL)
234 		panic("config_intrhook_disestablish: disestablishing an "
235 		      "unestablished hook");
236 
237 	if (next_to_notify == hook)
238 		next_to_notify = TAILQ_NEXT(hook, ich_links);
239 	TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links);
240 
241 	/* Wakeup anyone watching the list */
242 	wakeup(&intr_config_hook_list);
243 	mtx_unlock(&intr_config_hook_lock);
244 }
245 
246 #ifdef DDB
247 #include <ddb/ddb.h>
248 
249 DB_SHOW_COMMAND(conifhk, db_show_conifhk)
250 {
251 	struct intr_config_hook *hook_entry;
252 	char namebuf[64];
253 	long offset;
254 
255 	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
256 		if (linker_ddb_search_symbol_name(
257 		    (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf),
258 		    &offset) == 0) {
259 			db_printf("hook: %p at %s+%#lx arg: %p\n",
260 			    hook_entry->ich_func, namebuf, offset,
261 			    hook_entry->ich_arg);
262 		} else {
263 			db_printf("hook: %p at ??+?? arg %p\n",
264 			    hook_entry->ich_func, hook_entry->ich_arg);
265 		}
266 	}
267 }
268 #endif /* DDB */
269