xref: /freebsd/sys/kern/subr_autoconf.c (revision 7aa383846770374466b1dcb2cefd71bde9acf463)
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 mtx intr_config_hook_lock;
59 MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF);
60 
61 /* ARGSUSED */
62 static void run_interrupt_driven_config_hooks(void *dummy);
63 
64 /*
65  * If we wait too long for an interrupt-driven config hook to return, print
66  * a diagnostic.
67  */
68 #define	WARNING_INTERVAL_SECS	60
69 static void
70 run_interrupt_driven_config_hooks_warning(int warned)
71 {
72 	struct intr_config_hook *hook_entry;
73 	char namebuf[64];
74 	long offset;
75 
76 	if (warned < 6) {
77 		printf("run_interrupt_driven_hooks: still waiting after %d "
78 		    "seconds for", warned * WARNING_INTERVAL_SECS);
79 		TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
80 			if (linker_search_symbol_name(
81 			    (caddr_t)hook_entry->ich_func, namebuf,
82 			    sizeof(namebuf), &offset) == 0)
83 				printf(" %s", namebuf);
84 			else
85 				printf(" %p", hook_entry->ich_func);
86 		}
87 		printf("\n");
88 	}
89 	KASSERT(warned < 6,
90 	    ("run_interrupt_driven_config_hooks: waited too long"));
91 }
92 
93 static void
94 run_interrupt_driven_config_hooks(void *dummy)
95 {
96 	struct intr_config_hook *hook_entry, *next_entry;
97 	int warned;
98 
99 	mtx_lock(&intr_config_hook_lock);
100 	TAILQ_FOREACH_SAFE(hook_entry, &intr_config_hook_list, ich_links,
101 	    next_entry) {
102 		mtx_unlock(&intr_config_hook_lock);
103 		(*hook_entry->ich_func)(hook_entry->ich_arg);
104 		mtx_lock(&intr_config_hook_lock);
105 	}
106 
107 	warned = 0;
108 	while (!TAILQ_EMPTY(&intr_config_hook_list)) {
109 		if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
110 		    PCONFIG, "conifhk", WARNING_INTERVAL_SECS * hz) ==
111 		    EWOULDBLOCK) {
112 			mtx_unlock(&intr_config_hook_lock);
113 			warned++;
114 			run_interrupt_driven_config_hooks_warning(warned);
115 			mtx_lock(&intr_config_hook_lock);
116 		}
117 	}
118 	mtx_unlock(&intr_config_hook_lock);
119 }
120 SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
121 	run_interrupt_driven_config_hooks, NULL);
122 
123 /*
124  * Register a hook that will be called after "cold"
125  * autoconfiguration is complete and interrupts can
126  * be used to complete initialization.
127  */
128 int
129 config_intrhook_establish(struct intr_config_hook *hook)
130 {
131 	struct intr_config_hook *hook_entry;
132 
133 	mtx_lock(&intr_config_hook_lock);
134 	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
135 		if (hook_entry == hook)
136 			break;
137 	if (hook_entry != NULL) {
138 		mtx_unlock(&intr_config_hook_lock);
139 		printf("config_intrhook_establish: establishing an "
140 		       "already established hook.\n");
141 		return (1);
142 	}
143 	TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
144 	mtx_unlock(&intr_config_hook_lock);
145 	if (cold == 0)
146 		/* XXX Sufficient for modules loaded after initial config??? */
147 		run_interrupt_driven_config_hooks(NULL);
148 	return (0);
149 }
150 
151 void
152 config_intrhook_disestablish(struct intr_config_hook *hook)
153 {
154 	struct intr_config_hook *hook_entry;
155 
156 	mtx_lock(&intr_config_hook_lock);
157 	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
158 		if (hook_entry == hook)
159 			break;
160 	if (hook_entry == NULL)
161 		panic("config_intrhook_disestablish: disestablishing an "
162 		      "unestablished hook");
163 
164 	TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links);
165 
166 	/* Wakeup anyone watching the list */
167 	wakeup(&intr_config_hook_list);
168 	mtx_unlock(&intr_config_hook_lock);
169 }
170 
171 #ifdef DDB
172 #include <ddb/ddb.h>
173 
174 DB_SHOW_COMMAND(conifhk, db_show_conifhk)
175 {
176 	struct intr_config_hook *hook_entry;
177 	char namebuf[64];
178 	long offset;
179 
180 	TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
181 		if (linker_ddb_search_symbol_name(
182 		    (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf),
183 		    &offset) == 0) {
184 			db_printf("hook: %p at %s+%#lx arg: %p\n",
185 			    hook_entry->ich_func, namebuf, offset,
186 			    hook_entry->ich_arg);
187 		} else {
188 			db_printf("hook: %p at ??+?? arg %p\n",
189 			    hook_entry->ich_func, hook_entry->ich_arg);
190 		}
191 	}
192 }
193 #endif /* DDB */
194