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: releng/7.3/sys/kern/subr_autoconf.c 180855 2008-07-27 23:28:29Z rwatson $");
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(dummy)
95 void *dummy;
96 {
97 struct intr_config_hook *hook_entry, *next_entry;
98 int warned;
99
100 mtx_lock(&intr_config_hook_lock);
101 TAILQ_FOREACH_SAFE(hook_entry, &intr_config_hook_list, ich_links,
102 next_entry) {
103 mtx_unlock(&intr_config_hook_lock);
104 (*hook_entry->ich_func)(hook_entry->ich_arg);
105 mtx_lock(&intr_config_hook_lock);
106 }
107
108 warned = 0;
109 while (!TAILQ_EMPTY(&intr_config_hook_list)) {
110 if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
111 PCONFIG, "conifhk", WARNING_INTERVAL_SECS * hz) ==
112 EWOULDBLOCK) {
113 mtx_unlock(&intr_config_hook_lock);
114 warned++;
115 run_interrupt_driven_config_hooks_warning(warned);
116 mtx_lock(&intr_config_hook_lock);
117 }
118 }
119 mtx_unlock(&intr_config_hook_lock);
120 }
121 SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
122 run_interrupt_driven_config_hooks, NULL);
123
124 /*
125 * Register a hook that will be called after "cold"
126 * autoconfiguration is complete and interrupts can
127 * be used to complete initialization.
128 */
129 int
130 config_intrhook_establish(hook)
131 struct intr_config_hook *hook;
132 {
133 struct intr_config_hook *hook_entry;
134
135 mtx_lock(&intr_config_hook_lock);
136 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
137 if (hook_entry == hook)
138 break;
139 if (hook_entry != NULL) {
140 mtx_unlock(&intr_config_hook_lock);
141 printf("config_intrhook_establish: establishing an "
142 "already established hook.\n");
143 return (1);
144 }
145 TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
146 mtx_unlock(&intr_config_hook_lock);
147 if (cold == 0)
148 /* XXX Sufficient for modules loaded after initial config??? */
149 run_interrupt_driven_config_hooks(NULL);
150 return (0);
151 }
152
153 void
154 config_intrhook_disestablish(hook)
155 struct intr_config_hook *hook;
156 {
157 struct intr_config_hook *hook_entry;
158
159 mtx_lock(&intr_config_hook_lock);
160 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
161 if (hook_entry == hook)
162 break;
163 if (hook_entry == NULL)
164 panic("config_intrhook_disestablish: disestablishing an "
165 "unestablished hook");
166
167 TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links);
168
169 /* Wakeup anyone watching the list */
170 wakeup(&intr_config_hook_list);
171 mtx_unlock(&intr_config_hook_lock);
172 }
173
174 #ifdef DDB
175 #include <ddb/ddb.h>
176
177 DB_SHOW_COMMAND(conifhk, db_show_conifhk)
178 {
179 struct intr_config_hook *hook_entry;
180 char namebuf[64];
181 long offset;
182
183 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
184 if (linker_ddb_search_symbol_name(
185 (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf),
186 &offset) == 0) {
187 db_printf("hook: %p at %s+%#lx arg: %p\n",
188 hook_entry->ich_func, namebuf, offset,
189 hook_entry->ich_arg);
190 } else {
191 db_printf("hook: %p at ??+?? arg %p\n",
192 hook_entry->ich_func, hook_entry->ich_arg);
193 }
194 }
195 }
196 #endif /* DDB */
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