1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This software was developed by the Computer Systems Engineering group
8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9 * contributed to Berkeley.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)subr_autoconf.c 8.1 (Berkeley) 6/10/93
36 *
37 */
38
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41
42 #include "opt_ddb.h"
43
44 #include <sys/param.h>
45 #include <sys/kernel.h>
46 #include <sys/linker.h>
47 #include <sys/lock.h>
48 #include <sys/malloc.h>
49 #include <sys/mutex.h>
50 #include <sys/systm.h>
51
52 /*
53 * Autoconfiguration subroutines.
54 */
55
56 /*
57 * "Interrupt driven config" functions.
58 */
59 static TAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
60 TAILQ_HEAD_INITIALIZER(intr_config_hook_list);
61 static struct intr_config_hook *next_to_notify;
62 static struct mtx intr_config_hook_lock;
63 MTX_SYSINIT(intr_config_hook, &intr_config_hook_lock, "intr config", MTX_DEF);
64
65 /* ARGSUSED */
66 static void run_interrupt_driven_config_hooks(void);
67
68 /*
69 * Private data and a shim function for implementing config_interhook_oneshot().
70 */
71 struct oneshot_config_hook {
72 struct intr_config_hook
73 och_hook; /* Must be first */
74 ich_func_t och_func;
75 void *och_arg;
76 };
77
78 static void
79 config_intrhook_oneshot_func(void *arg)
80 {
81 struct oneshot_config_hook *ohook;
82
83 ohook = arg;
84 ohook->och_func(ohook->och_arg);
85 config_intrhook_disestablish(&ohook->och_hook);
86 free(ohook, M_DEVBUF);
87 }
88
89 /*
90 * If we wait too long for an interrupt-driven config hook to return, print
91 * a diagnostic.
92 */
93 #define WARNING_INTERVAL_SECS 60
94 static void
95 run_interrupt_driven_config_hooks_warning(int warned)
96 {
97 struct intr_config_hook *hook_entry;
98 char namebuf[64];
99 long offset;
100
101 if (warned < 6) {
102 printf("run_interrupt_driven_hooks: still waiting after %d "
103 "seconds for", warned * WARNING_INTERVAL_SECS);
104 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
105 if (linker_search_symbol_name(
106 (caddr_t)hook_entry->ich_func, namebuf,
107 sizeof(namebuf), &offset) == 0)
108 printf(" %s", namebuf);
109 else
110 printf(" %p", hook_entry->ich_func);
111 }
112 printf("\n");
113 }
114 KASSERT(warned < 6,
115 ("run_interrupt_driven_config_hooks: waited too long"));
116 }
117
118 static void
119 run_interrupt_driven_config_hooks(void)
120 {
121 static int running;
122 struct intr_config_hook *hook_entry;
123
124 mtx_lock(&intr_config_hook_lock);
125
126 /*
127 * If hook processing is already active, any newly
128 * registered hooks will eventually be notified.
129 * Let the currently running session issue these
130 * notifications.
131 */
132 if (running != 0) {
133 mtx_unlock(&intr_config_hook_lock);
134 return;
135 }
136 running = 1;
137
138 while (next_to_notify != NULL) {
139 hook_entry = next_to_notify;
140 next_to_notify = TAILQ_NEXT(hook_entry, ich_links);
141 hook_entry->ich_state = ICHS_RUNNING;
142 mtx_unlock(&intr_config_hook_lock);
143 (*hook_entry->ich_func)(hook_entry->ich_arg);
144 mtx_lock(&intr_config_hook_lock);
145 }
146
147 running = 0;
148 mtx_unlock(&intr_config_hook_lock);
149 }
150
151 static void
152 boot_run_interrupt_driven_config_hooks(void *dummy)
153 {
154 int warned;
155
156 run_interrupt_driven_config_hooks();
157
158 /* Block boot processing until all hooks are disestablished. */
159 TSWAIT("config hooks");
160 mtx_lock(&intr_config_hook_lock);
161 warned = 0;
162 while (!TAILQ_EMPTY(&intr_config_hook_list)) {
163 if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
164 0, "conifhk", WARNING_INTERVAL_SECS * hz) ==
165 EWOULDBLOCK) {
166 mtx_unlock(&intr_config_hook_lock);
167 warned++;
168 run_interrupt_driven_config_hooks_warning(warned);
169 mtx_lock(&intr_config_hook_lock);
170 }
171 }
172 mtx_unlock(&intr_config_hook_lock);
173 TSUNWAIT("config hooks");
174 }
175
176 SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
177 boot_run_interrupt_driven_config_hooks, NULL);
178
179 /*
180 * Register a hook that will be called after "cold"
181 * autoconfiguration is complete and interrupts can
182 * be used to complete initialization.
183 */
184 int
185 config_intrhook_establish(struct intr_config_hook *hook)
186 {
187 struct intr_config_hook *hook_entry;
188
189 TSHOLD("config hooks");
190 mtx_lock(&intr_config_hook_lock);
191 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
192 if (hook_entry == hook)
193 break;
194 if (hook_entry != NULL) {
195 mtx_unlock(&intr_config_hook_lock);
196 printf("config_intrhook_establish: establishing an "
197 "already established hook.\n");
198 return (1);
199 }
200 TAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
201 if (next_to_notify == NULL)
202 next_to_notify = hook;
203 hook->ich_state = ICHS_QUEUED;
204 mtx_unlock(&intr_config_hook_lock);
205 if (cold == 0)
206 /*
207 * XXX Call from a task since not all drivers expect
208 * to be re-entered at the time a hook is established.
209 */
210 /* XXX Sufficient for modules loaded after initial config??? */
211 run_interrupt_driven_config_hooks();
212 return (0);
213 }
214
215 /*
216 * Register a hook function that is automatically unregistered after it runs.
217 */
218 void
219 config_intrhook_oneshot(ich_func_t func, void *arg)
220 {
221 struct oneshot_config_hook *ohook;
222
223 ohook = malloc(sizeof(*ohook), M_DEVBUF, M_WAITOK);
224 ohook->och_func = func;
225 ohook->och_arg = arg;
226 ohook->och_hook.ich_func = config_intrhook_oneshot_func;
227 ohook->och_hook.ich_arg = ohook;
228 config_intrhook_establish(&ohook->och_hook);
229 }
230
231 static void
232 config_intrhook_disestablish_locked(struct intr_config_hook *hook)
233 {
234 struct intr_config_hook *hook_entry;
235
236 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
237 if (hook_entry == hook)
238 break;
239 if (hook_entry == NULL)
240 panic("config_intrhook_disestablish: disestablishing an "
241 "unestablished hook");
242
243 if (next_to_notify == hook)
244 next_to_notify = TAILQ_NEXT(hook, ich_links);
245 TAILQ_REMOVE(&intr_config_hook_list, hook, ich_links);
246 TSRELEASE("config hooks");
247
248 /* Wakeup anyone watching the list */
249 hook->ich_state = ICHS_DONE;
250 wakeup(&intr_config_hook_list);
251 }
252
253 void
254 config_intrhook_disestablish(struct intr_config_hook *hook)
255 {
256 mtx_lock(&intr_config_hook_lock);
257 config_intrhook_disestablish_locked(hook);
258 mtx_unlock(&intr_config_hook_lock);
259 }
260
261 int
262 config_intrhook_drain(struct intr_config_hook *hook)
263 {
264 mtx_lock(&intr_config_hook_lock);
265
266 /*
267 * The config hook has completed, so just return.
268 */
269 if (hook->ich_state == ICHS_DONE) {
270 mtx_unlock(&intr_config_hook_lock);
271 return (ICHS_DONE);
272 }
273
274 /*
275 * The config hook hasn't started running, just call disestablish.
276 */
277 if (hook->ich_state == ICHS_QUEUED) {
278 config_intrhook_disestablish_locked(hook);
279 mtx_unlock(&intr_config_hook_lock);
280 return (ICHS_QUEUED);
281 }
282
283 /*
284 * The config hook is running, so wait for it to complete and return.
285 */
286 while (hook->ich_state != ICHS_DONE) {
287 if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
288 0, "confhd", hz) == EWOULDBLOCK) {
289 // XXX do I whine?
290 }
291 }
292 mtx_unlock(&intr_config_hook_lock);
293 return (ICHS_RUNNING);
294 }
295
296 #ifdef DDB
297 #include <ddb/ddb.h>
298
299 DB_SHOW_COMMAND(conifhk, db_show_conifhk)
300 {
301 struct intr_config_hook *hook_entry;
302 char namebuf[64];
303 long offset;
304
305 TAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
306 if (linker_ddb_search_symbol_name(
307 (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf),
308 &offset) == 0) {
309 db_printf("hook: %p at %s+%#lx arg: %p\n",
310 hook_entry->ich_func, namebuf, offset,
311 hook_entry->ich_arg);
312 } else {
313 db_printf("hook: %p at ??+?? arg %p\n",
314 hook_entry->ich_func, hook_entry->ich_arg);
315 }
316 }
317 }
318 #endif /* DDB */
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