xref: /freebsd/sys/kern/subr_autoconf.c (revision 0f2bd1e89db1a2f09268edea21e0ead329e092df)
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  * 4. 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/mutex.h>
47 #include <sys/systm.h>
48 
49 /*
50  * Autoconfiguration subroutines.
51  */
52 
53 /*
54  * "Interrupt driven config" functions.
55  */
56 static TAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
57 	TAILQ_HEAD_INITIALIZER(intr_config_hook_list);
58 static struct intr_config_hook *next_to_notify;
59 static struct mtx intr_config_hook_lock;
60 MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF);
61 
62 /* ARGSUSED */
63 static void run_interrupt_driven_config_hooks(void);
64 
65 /*
66  * If we wait too long for an interrupt-driven config hook to return, print
67  * a diagnostic.
68  */
69 #define	WARNING_INTERVAL_SECS	60
70 static void
71 run_interrupt_driven_config_hooks_warning(int warned)
72 {
73 	struct intr_config_hook *hook_entry;
74 	char namebuf[64];
75 	long offset;
76 
77 	if (warned < 6) {
78 		printf("run_interrupt_driven_hooks: still waiting after %d "
79 		    "seconds for", warned * WARNING_INTERVAL_SECS);
80 		TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
81 			if (linker_search_symbol_name(
82 			    (caddr_t)hook_entry->ich_func, namebuf,
83 			    sizeof(namebuf), &offset) == 0)
84 				printf(" %s", namebuf);
85 			else
86 				printf(" %p", hook_entry->ich_func);
87 		}
88 		printf("\n");
89 	}
90 	KASSERT(warned < 6,
91 	    ("run_interrupt_driven_config_hooks: waited too long"));
92 }
93 
94 static void
95 run_interrupt_driven_config_hooks()
96 {
97 	static int running;
98 	struct intr_config_hook *hook_entry;
99 
100 	mtx_lock(&intr_config_hook_lock);
101 
102 	/*
103 	 * If hook processing is already active, any newly
104 	 * registered hooks will eventually be notified.
105 	 * Let the currently running session issue these
106 	 * notifications.
107 	 */
108 	if (running != 0) {
109 		mtx_unlock(&intr_config_hook_lock);
110 		return;
111 	}
112 	running = 1;
113 
114 	while (next_to_notify != NULL) {
115 		hook_entry = next_to_notify;
116 		next_to_notify = TAILQ_NEXT(hook_entry, ich_links);
117 		mtx_unlock(&intr_config_hook_lock);
118 		(*hook_entry->ich_func)(hook_entry->ich_arg);
119 		mtx_lock(&intr_config_hook_lock);
120 	}
121 
122 	running = 0;
123 	mtx_unlock(&intr_config_hook_lock);
124 }
125 
126 static void
127 boot_run_interrupt_driven_config_hooks(void *dummy)
128 {
129 	int warned;
130 
131 	run_interrupt_driven_config_hooks();
132 
133 	/* Block boot processing until all hooks are disestablished. */
134 	mtx_lock(&intr_config_hook_lock);
135 	warned = 0;
136 	while (!TAILQ_EMPTY(&intr_config_hook_list)) {
137 		if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
138 		    PCONFIG, "conifhk", WARNING_INTERVAL_SECS * hz) ==
139 		    EWOULDBLOCK) {
140 			mtx_unlock(&intr_config_hook_lock);
141 			warned++;
142 			run_interrupt_driven_config_hooks_warning(warned);
143 			mtx_lock(&intr_config_hook_lock);
144 		}
145 	}
146 	mtx_unlock(&intr_config_hook_lock);
147 }
148 
149 SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
150 	boot_run_interrupt_driven_config_hooks, NULL);
151 
152 /*
153  * Register a hook that will be called after "cold"
154  * autoconfiguration is complete and interrupts can
155  * be used to complete initialization.
156  */
157 int
158 config_intrhook_establish(struct intr_config_hook *hook)
159 {
160 	struct intr_config_hook *hook_entry;
161 
162 	mtx_lock(&intr_config_hook_lock);
163 	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
164 		if (hook_entry == hook)
165 			break;
166 	if (hook_entry != NULL) {
167 		mtx_unlock(&intr_config_hook_lock);
168 		printf("config_intrhook_establish: establishing an "
169 		       "already established hook.\n");
170 		return (1);
171 	}
172 	TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
173 	if (next_to_notify == NULL)
174 		next_to_notify = hook;
175 	mtx_unlock(&intr_config_hook_lock);
176 	if (cold == 0)
177 		/*
178 		 * XXX Call from a task since not all drivers expect
179 		 *     to be re-entered at the time a hook is established.
180 		 */
181 		/* XXX Sufficient for modules loaded after initial config??? */
182 		run_interrupt_driven_config_hooks();
183 	return (0);
184 }
185 
186 void
187 config_intrhook_disestablish(struct intr_config_hook *hook)
188 {
189 	struct intr_config_hook *hook_entry;
190 
191 	mtx_lock(&intr_config_hook_lock);
192 	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
193 		if (hook_entry == hook)
194 			break;
195 	if (hook_entry == NULL)
196 		panic("config_intrhook_disestablish: disestablishing an "
197 		      "unestablished hook");
198 
199 	if (next_to_notify == hook)
200 		next_to_notify = TAILQ_NEXT(hook, ich_links);
201 	TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links);
202 
203 	/* Wakeup anyone watching the list */
204 	wakeup(&intr_config_hook_list);
205 	mtx_unlock(&intr_config_hook_lock);
206 }
207 
208 #ifdef DDB
209 #include <ddb/ddb.h>
210 
211 DB_SHOW_COMMAND(conifhk, db_show_conifhk)
212 {
213 	struct intr_config_hook *hook_entry;
214 	char namebuf[64];
215 	long offset;
216 
217 	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
218 		if (linker_ddb_search_symbol_name(
219 		    (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf),
220 		    &offset) == 0) {
221 			db_printf("hook: %p at %s+%#lx arg: %p\n",
222 			    hook_entry->ich_func, namebuf, offset,
223 			    hook_entry->ich_arg);
224 		} else {
225 			db_printf("hook: %p at ??+?? arg %p\n",
226 			    hook_entry->ich_func, hook_entry->ich_arg);
227 		}
228 	}
229 }
230 #endif /* DDB */
231