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 */
36
37 #include <sys/cdefs.h>
38 #include "opt_ddb.h"
39
40 #include <sys/param.h>
41 #include <sys/kernel.h>
42 #include <sys/linker.h>
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/mutex.h>
46 #include <sys/systm.h>
47
48 /*
49 * Autoconfiguration subroutines.
50 */
51
52 /*
53 * "Interrupt driven config" functions.
54 */
55 static STAILQ_HEAD(, intr_config_hook) intr_config_hook_list =
56 STAILQ_HEAD_INITIALIZER(intr_config_hook_list);
57 static struct intr_config_hook *next_to_notify;
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);
63
64 /*
65 * Private data and a shim function for implementing config_interhook_oneshot().
66 */
67 struct oneshot_config_hook {
68 struct intr_config_hook
69 och_hook; /* Must be first */
70 ich_func_t och_func;
71 void *och_arg;
72 };
73
74 static void
config_intrhook_oneshot_func(void * arg)75 config_intrhook_oneshot_func(void *arg)
76 {
77 struct oneshot_config_hook *ohook;
78
79 ohook = arg;
80 ohook->och_func(ohook->och_arg);
81 config_intrhook_disestablish(&ohook->och_hook);
82 free(ohook, M_DEVBUF);
83 }
84
85 /*
86 * If we wait too long for an interrupt-driven config hook to return, print
87 * a diagnostic.
88 */
89 #define WARNING_INTERVAL_SECS 60
90 static void
run_interrupt_driven_config_hooks_warning(int warned)91 run_interrupt_driven_config_hooks_warning(int warned)
92 {
93 struct intr_config_hook *hook_entry;
94 char namebuf[64];
95 long offset;
96
97 if (warned < 6) {
98 printf("run_interrupt_driven_hooks: still waiting after %d "
99 "seconds for", warned * WARNING_INTERVAL_SECS);
100 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
101 if (linker_search_symbol_name(
102 (caddr_t)hook_entry->ich_func, namebuf,
103 sizeof(namebuf), &offset) == 0)
104 printf(" %s", namebuf);
105 else
106 printf(" %p", hook_entry->ich_func);
107 }
108 printf("\n");
109 }
110 KASSERT(warned < 6,
111 ("run_interrupt_driven_config_hooks: waited too long"));
112 }
113
114 static void
run_interrupt_driven_config_hooks(void)115 run_interrupt_driven_config_hooks(void)
116 {
117 static int running;
118 struct intr_config_hook *hook_entry;
119
120 TSENTER();
121 mtx_lock(&intr_config_hook_lock);
122
123 /*
124 * If hook processing is already active, any newly
125 * registered hooks will eventually be notified.
126 * Let the currently running session issue these
127 * notifications.
128 */
129 if (running != 0) {
130 mtx_unlock(&intr_config_hook_lock);
131 return;
132 }
133 running = 1;
134
135 while (next_to_notify != NULL) {
136 hook_entry = next_to_notify;
137 next_to_notify = STAILQ_NEXT(hook_entry, ich_links);
138 hook_entry->ich_state = ICHS_RUNNING;
139 mtx_unlock(&intr_config_hook_lock);
140 (*hook_entry->ich_func)(hook_entry->ich_arg);
141 mtx_lock(&intr_config_hook_lock);
142 }
143
144 running = 0;
145 mtx_unlock(&intr_config_hook_lock);
146 TSEXIT();
147 }
148
149 static void
boot_run_interrupt_driven_config_hooks(void * dummy)150 boot_run_interrupt_driven_config_hooks(void *dummy)
151 {
152 int warned;
153
154 run_interrupt_driven_config_hooks();
155
156 /* Block boot processing until all hooks are disestablished. */
157 TSWAIT("config hooks");
158 mtx_lock(&intr_config_hook_lock);
159 warned = 0;
160 while (!STAILQ_EMPTY(&intr_config_hook_list)) {
161 if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
162 0, "conifhk", WARNING_INTERVAL_SECS * hz) ==
163 EWOULDBLOCK) {
164 mtx_unlock(&intr_config_hook_lock);
165 warned++;
166 run_interrupt_driven_config_hooks_warning(warned);
167 mtx_lock(&intr_config_hook_lock);
168 }
169 }
170 mtx_unlock(&intr_config_hook_lock);
171 TSUNWAIT("config hooks");
172 }
173
174 SYSINIT(intr_config_hooks, SI_SUB_INT_CONFIG_HOOKS, SI_ORDER_FIRST,
175 boot_run_interrupt_driven_config_hooks, NULL);
176
177 /*
178 * Register a hook that will be called after "cold"
179 * autoconfiguration is complete and interrupts can
180 * be used to complete initialization.
181 */
182 int
config_intrhook_establish(struct intr_config_hook * hook)183 config_intrhook_establish(struct intr_config_hook *hook)
184 {
185 struct intr_config_hook *hook_entry;
186
187 TSHOLD("config hooks");
188 mtx_lock(&intr_config_hook_lock);
189 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
190 if (hook_entry == hook)
191 break;
192 if (hook_entry != NULL) {
193 mtx_unlock(&intr_config_hook_lock);
194 printf("config_intrhook_establish: establishing an "
195 "already established hook.\n");
196 return (1);
197 }
198 STAILQ_INSERT_TAIL(&intr_config_hook_list, hook, ich_links);
199 if (next_to_notify == NULL)
200 next_to_notify = hook;
201 hook->ich_state = ICHS_QUEUED;
202 mtx_unlock(&intr_config_hook_lock);
203 if (cold == 0)
204 /*
205 * XXX Call from a task since not all drivers expect
206 * to be re-entered at the time a hook is established.
207 */
208 /* XXX Sufficient for modules loaded after initial config??? */
209 run_interrupt_driven_config_hooks();
210 return (0);
211 }
212
213 /*
214 * Register a hook function that is automatically unregistered after it runs.
215 */
216 void
config_intrhook_oneshot(ich_func_t func,void * arg)217 config_intrhook_oneshot(ich_func_t func, void *arg)
218 {
219 struct oneshot_config_hook *ohook;
220
221 ohook = malloc(sizeof(*ohook), M_DEVBUF, M_WAITOK);
222 ohook->och_func = func;
223 ohook->och_arg = arg;
224 ohook->och_hook.ich_func = config_intrhook_oneshot_func;
225 ohook->och_hook.ich_arg = ohook;
226 config_intrhook_establish(&ohook->och_hook);
227 }
228
229 static void
config_intrhook_disestablish_locked(struct intr_config_hook * hook)230 config_intrhook_disestablish_locked(struct intr_config_hook *hook)
231 {
232 struct intr_config_hook *hook_entry;
233
234 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links)
235 if (hook_entry == hook)
236 break;
237 if (hook_entry == NULL)
238 panic("config_intrhook_disestablish: disestablishing an "
239 "unestablished hook");
240
241 if (next_to_notify == hook)
242 next_to_notify = STAILQ_NEXT(hook, ich_links);
243 STAILQ_REMOVE(&intr_config_hook_list, hook, intr_config_hook, ich_links);
244 TSRELEASE("config hooks");
245
246 /* Wakeup anyone watching the list */
247 hook->ich_state = ICHS_DONE;
248 wakeup(&intr_config_hook_list);
249 }
250
251 void
config_intrhook_disestablish(struct intr_config_hook * hook)252 config_intrhook_disestablish(struct intr_config_hook *hook)
253 {
254 mtx_lock(&intr_config_hook_lock);
255 config_intrhook_disestablish_locked(hook);
256 mtx_unlock(&intr_config_hook_lock);
257 }
258
259 int
config_intrhook_drain(struct intr_config_hook * hook)260 config_intrhook_drain(struct intr_config_hook *hook)
261 {
262 mtx_lock(&intr_config_hook_lock);
263
264 /*
265 * The config hook has completed, so just return.
266 */
267 if (hook->ich_state == ICHS_DONE) {
268 mtx_unlock(&intr_config_hook_lock);
269 return (ICHS_DONE);
270 }
271
272 /*
273 * The config hook hasn't started running, just call disestablish.
274 */
275 if (hook->ich_state == ICHS_QUEUED) {
276 config_intrhook_disestablish_locked(hook);
277 mtx_unlock(&intr_config_hook_lock);
278 return (ICHS_QUEUED);
279 }
280
281 /*
282 * The config hook is running, so wait for it to complete and return.
283 */
284 while (hook->ich_state != ICHS_DONE) {
285 if (msleep(&intr_config_hook_list, &intr_config_hook_lock,
286 0, "confhd", hz) == EWOULDBLOCK) {
287 // XXX do I whine?
288 }
289 }
290 mtx_unlock(&intr_config_hook_lock);
291 return (ICHS_RUNNING);
292 }
293
294 #ifdef DDB
295 #include <ddb/ddb.h>
296
DB_SHOW_COMMAND_FLAGS(conifhk,db_show_conifhk,DB_CMD_MEMSAFE)297 DB_SHOW_COMMAND_FLAGS(conifhk, db_show_conifhk, DB_CMD_MEMSAFE)
298 {
299 struct intr_config_hook *hook_entry;
300 char namebuf[64];
301 long offset;
302
303 STAILQ_FOREACH(hook_entry, &intr_config_hook_list, ich_links) {
304 if (linker_ddb_search_symbol_name(
305 (caddr_t)hook_entry->ich_func, namebuf, sizeof(namebuf),
306 &offset) == 0) {
307 db_printf("hook: %p at %s+%#lx arg: %p\n",
308 hook_entry->ich_func, namebuf, offset,
309 hook_entry->ich_arg);
310 } else {
311 db_printf("hook: %p at ??+?? arg %p\n",
312 hook_entry->ich_func, hook_entry->ich_arg);
313 }
314 }
315 }
316 #endif /* DDB */
317