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 STAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
60 STAILQ_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 STAILQ_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 TSENTER();
125 mtx_lock(&intr_config_hook_lock);
126
127 /*
128 * If hook processing is already active, any newly
129 * registered hooks will eventually be notified.
130 * Let the currently running session issue these
131 * notifications.
132 */
133 if (running != 0) {
134 mtx_unlock(&intr_config_hook_lock);
135 return;
136 }
137 running = 1;
138
139 while (next_to_notify != NULL) {
140 hook_entry = next_to_notify;
141 next_to_notify = STAILQ_NEXT(hook_entry, ich_links);
142 hook_entry->ich_state = ICHS_RUNNING;
143 mtx_unlock(&intr_config_hook_lock);
144 (*hook_entry->ich_func)(hook_entry->ich_arg);
145 mtx_lock(&intr_config_hook_lock);
146 }
147
148 running = 0;
149 mtx_unlock(&intr_config_hook_lock);
150 TSEXIT();
151 }
152
153 static void
154 boot_run_interrupt_driven_config_hooks(void *dummy)
155 {
156 int warned;
157
158 run_interrupt_driven_config_hooks();
159
160 /* Block boot processing until all hooks are disestablished. */
161 TSWAIT("config hooks");
162 mtx_lock(&intr_config_hook_lock);
163 warned = 0;
164 while (!STAILQ_EMPTY(&intr_config_hook_list)) {
165 if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
166 0, "conifhk", WARNING_INTERVAL_SECS * hz) ==
167 EWOULDBLOCK) {
168 mtx_unlock(&intr_config_hook_lock);
169 warned++;
170 run_interrupt_driven_config_hooks_warning(warned);
171 mtx_lock(&intr_config_hook_lock);
172 }
173 }
174 mtx_unlock(&intr_config_hook_lock);
175 TSUNWAIT("config hooks");
176 }
177
178 SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
179 boot_run_interrupt_driven_config_hooks, NULL);
180
181 /*
182 * Register a hook that will be called after "cold"
183 * autoconfiguration is complete and interrupts can
184 * be used to complete initialization.
185 */
186 int
187 config_intrhook_establish(struct intr_config_hook *hook)
188 {
189 struct intr_config_hook *hook_entry;
190
191 TSHOLD("config hooks");
192 mtx_lock(&intr_config_hook_lock);
193 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
194 if (hook_entry == hook)
195 break;
196 if (hook_entry != NULL) {
197 mtx_unlock(&intr_config_hook_lock);
198 printf("config_intrhook_establish: establishing an "
199 "already established hook.\n");
200 return (1);
201 }
202 STAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
203 if (next_to_notify == NULL)
204 next_to_notify = hook;
205 hook->ich_state = ICHS_QUEUED;
206 mtx_unlock(&intr_config_hook_lock);
207 if (cold == 0)
208 /*
209 * XXX Call from a task since not all drivers expect
210 * to be re-entered at the time a hook is established.
211 */
212 /* XXX Sufficient for modules loaded after initial config??? */
213 run_interrupt_driven_config_hooks();
214 return (0);
215 }
216
217 /*
218 * Register a hook function that is automatically unregistered after it runs.
219 */
220 void
221 config_intrhook_oneshot(ich_func_t func, void *arg)
222 {
223 struct oneshot_config_hook *ohook;
224
225 ohook = malloc(sizeof(*ohook), M_DEVBUF, M_WAITOK);
226 ohook->och_func = func;
227 ohook->och_arg = arg;
228 ohook->och_hook.ich_func = config_intrhook_oneshot_func;
229 ohook->och_hook.ich_arg = ohook;
230 config_intrhook_establish(&ohook->och_hook);
231 }
232
233 static void
234 config_intrhook_disestablish_locked(struct intr_config_hook *hook)
235 {
236 struct intr_config_hook *hook_entry;
237
238 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
239 if (hook_entry == hook)
240 break;
241 if (hook_entry == NULL)
242 panic("config_intrhook_disestablish: disestablishing an "
243 "unestablished hook");
244
245 if (next_to_notify == hook)
246 next_to_notify = STAILQ_NEXT(hook, ich_links);
247 STAILQ_REMOVE(&intr_config_hook_list, hook, intr_config_hook, ich_links);
248 TSRELEASE("config hooks");
249
250 /* Wakeup anyone watching the list */
251 hook->ich_state = ICHS_DONE;
252 wakeup(&intr_config_hook_list);
253 }
254
255 void
256 config_intrhook_disestablish(struct intr_config_hook *hook)
257 {
258 mtx_lock(&intr_config_hook_lock);
259 config_intrhook_disestablish_locked(hook);
260 mtx_unlock(&intr_config_hook_lock);
261 }
262
263 int
264 config_intrhook_drain(struct intr_config_hook *hook)
265 {
266 mtx_lock(&intr_config_hook_lock);
267
268 /*
269 * The config hook has completed, so just return.
270 */
271 if (hook->ich_state == ICHS_DONE) {
272 mtx_unlock(&intr_config_hook_lock);
273 return (ICHS_DONE);
274 }
275
276 /*
277 * The config hook hasn't started running, just call disestablish.
278 */
279 if (hook->ich_state == ICHS_QUEUED) {
280 config_intrhook_disestablish_locked(hook);
281 mtx_unlock(&intr_config_hook_lock);
282 return (ICHS_QUEUED);
283 }
284
285 /*
286 * The config hook is running, so wait for it to complete and return.
287 */
288 while (hook->ich_state != ICHS_DONE) {
289 if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
290 0, "confhd", hz) == EWOULDBLOCK) {
291 // XXX do I whine?
292 }
293 }
294 mtx_unlock(&intr_config_hook_lock);
295 return (ICHS_RUNNING);
296 }
297
298 #ifdef DDB
299 #include <ddb/ddb.h>
300
301 DB_SHOW_COMMAND_FLAGS(conifhk, db_show_conifhk, DB_CMD_MEMSAFE)
302 {
303 struct intr_config_hook *hook_entry;
304 char namebuf[64];
305 long offset;
306
307 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
308 if (linker_ddb_search_symbol_name(
309 (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf),
310 &offset) == 0) {
311 db_printf("hook: %p at %s+%#lx arg: %p\n",
312 hook_entry->ich_func, namebuf, offset,
313 hook_entry->ich_arg);
314 } else {
315 db_printf("hook: %p at ??+?? arg %p\n",
316 hook_entry->ich_func, hook_entry->ich_arg);
317 }
318 }
319 }
320 #endif /* DDB */
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