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/9.0/sys/kern/subr_autoconf.c 217075 2011-01-06 22:09:37Z jhb $");
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 0, "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 */
Cache object: e1c2a6eec9501991a1af032ebf4261f5
|