xref: /netbsd-src/sys/kern/kern_pmf.c (revision 4b71a66d0f279143147d63ebfcfd8a59499a3684)
1 /* $NetBSD: kern_pmf.c,v 1.19 2008/05/05 00:15:57 jmcneill Exp $ */
2 
3 /*-
4  * Copyright (c) 2007 Jared D. McNeill <jmcneill@invisible.ca>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: kern_pmf.c,v 1.19 2008/05/05 00:15:57 jmcneill Exp $");
31 
32 #include <sys/types.h>
33 #include <sys/param.h>
34 #include <sys/malloc.h>
35 #include <sys/buf.h>
36 #include <sys/callout.h>
37 #include <sys/kernel.h>
38 #include <sys/device.h>
39 #include <sys/pmf.h>
40 #include <sys/queue.h>
41 #include <sys/syscallargs.h> /* for sys_sync */
42 #include <sys/workqueue.h>
43 #include <prop/proplib.h>
44 #include <sys/condvar.h>
45 #include <sys/mutex.h>
46 #include <sys/proc.h>
47 #include <sys/reboot.h>	/* for RB_NOSYNC */
48 #include <sys/sched.h>
49 
50 /* XXX ugly special case, but for now the only client */
51 #include "wsdisplay.h"
52 #if NWSDISPLAY > 0
53 #include <dev/wscons/wsdisplayvar.h>
54 #endif
55 
56 #ifdef PMF_DEBUG
57 int pmf_debug_event;
58 int pmf_debug_idle;
59 int pmf_debug_transition;
60 
61 #define	PMF_EVENT_PRINTF(x)		if (pmf_debug_event) printf x
62 #define	PMF_IDLE_PRINTF(x)		if (pmf_debug_idle) printf x
63 #define	PMF_TRANSITION_PRINTF(x)	if (pmf_debug_transition) printf x
64 #define	PMF_TRANSITION_PRINTF2(y,x)	if (pmf_debug_transition>y) printf x
65 #else
66 #define	PMF_EVENT_PRINTF(x)		do { } while (0)
67 #define	PMF_IDLE_PRINTF(x)		do { } while (0)
68 #define	PMF_TRANSITION_PRINTF(x)	do { } while (0)
69 #define	PMF_TRANSITION_PRINTF2(y,x)	do { } while (0)
70 #endif
71 
72 /* #define PMF_DEBUG */
73 
74 MALLOC_DEFINE(M_PMF, "pmf", "device pmf messaging memory");
75 
76 static prop_dictionary_t pmf_platform = NULL;
77 static struct workqueue *pmf_event_workqueue;
78 
79 typedef struct pmf_event_handler {
80 	TAILQ_ENTRY(pmf_event_handler) pmf_link;
81 	pmf_generic_event_t pmf_event;
82 	void (*pmf_handler)(device_t);
83 	device_t pmf_device;
84 	bool pmf_global;
85 } pmf_event_handler_t;
86 
87 static TAILQ_HEAD(, pmf_event_handler) pmf_all_events =
88     TAILQ_HEAD_INITIALIZER(pmf_all_events);
89 
90 typedef struct pmf_event_workitem {
91 	struct work		pew_work;
92 	pmf_generic_event_t	pew_event;
93 	device_t		pew_device;
94 } pmf_event_workitem_t;
95 
96 struct shutdown_state {
97 	bool initialized;
98 	deviter_t di;
99 };
100 
101 static device_t shutdown_first(struct shutdown_state *);
102 static device_t shutdown_next(struct shutdown_state *);
103 
104 static bool pmf_device_resume_locked(device_t PMF_FN_PROTO);
105 static bool pmf_device_suspend_locked(device_t PMF_FN_PROTO);
106 
107 static void
108 pmf_event_worker(struct work *wk, void *dummy)
109 {
110 	pmf_event_workitem_t *pew;
111 	pmf_event_handler_t *event;
112 
113 	pew = (void *)wk;
114 	KASSERT(wk == &pew->pew_work);
115 	KASSERT(pew != NULL);
116 
117 	TAILQ_FOREACH(event, &pmf_all_events, pmf_link) {
118 		if (event->pmf_event != pew->pew_event)
119 			continue;
120 		if (event->pmf_device == pew->pew_device || event->pmf_global)
121 			(*event->pmf_handler)(event->pmf_device);
122 	}
123 
124 	free(pew, M_TEMP);
125 }
126 
127 static bool
128 pmf_check_system_drivers(void)
129 {
130 	device_t curdev;
131 	bool unsupported_devs;
132 	deviter_t di;
133 
134 	unsupported_devs = false;
135 	for (curdev = deviter_first(&di, 0); curdev != NULL;
136 	     curdev = deviter_next(&di)) {
137 		if (device_pmf_is_registered(curdev))
138 			continue;
139 		if (!unsupported_devs)
140 			printf("Devices without power management support:");
141 		printf(" %s", device_xname(curdev));
142 		unsupported_devs = true;
143 	}
144 	deviter_release(&di);
145 	if (unsupported_devs) {
146 		printf("\n");
147 		return false;
148 	}
149 	return true;
150 }
151 
152 bool
153 pmf_system_bus_resume(PMF_FN_ARGS1)
154 {
155 	bool rv;
156 	device_t curdev;
157 	deviter_t di;
158 
159 	aprint_debug("Powering devices:");
160 	/* D0 handlers are run in order */
161 	rv = true;
162 	for (curdev = deviter_first(&di, DEVITER_F_ROOT_FIRST); curdev != NULL;
163 	     curdev = deviter_next(&di)) {
164 		if (!device_pmf_is_registered(curdev))
165 			continue;
166 		if (device_is_active(curdev) ||
167 		    !device_is_enabled(curdev))
168 			continue;
169 
170 		aprint_debug(" %s", device_xname(curdev));
171 
172 		if (!device_pmf_bus_resume(curdev PMF_FN_CALL)) {
173 			rv = false;
174 			aprint_debug("(failed)");
175 		}
176 	}
177 	deviter_release(&di);
178 	aprint_debug("\n");
179 
180 	return rv;
181 }
182 
183 bool
184 pmf_system_resume(PMF_FN_ARGS1)
185 {
186 	bool rv;
187 	device_t curdev, parent;
188 	deviter_t di;
189 
190 	if (!pmf_check_system_drivers())
191 		return false;
192 
193 	aprint_debug("Resuming devices:");
194 	/* D0 handlers are run in order */
195 	rv = true;
196 	for (curdev = deviter_first(&di, DEVITER_F_ROOT_FIRST); curdev != NULL;
197 	     curdev = deviter_next(&di)) {
198 		if (device_is_active(curdev) ||
199 		    !device_is_enabled(curdev))
200 			continue;
201 		parent = device_parent(curdev);
202 		if (parent != NULL &&
203 		    !device_is_active(parent))
204 			continue;
205 
206 		aprint_debug(" %s", device_xname(curdev));
207 
208 		if (!pmf_device_resume(curdev PMF_FN_CALL)) {
209 			rv = false;
210 			aprint_debug("(failed)");
211 		}
212 	}
213 	deviter_release(&di);
214 	aprint_debug(".\n");
215 
216 	KERNEL_UNLOCK_ONE(0);
217 #if NWSDISPLAY > 0
218 	if (rv)
219 		wsdisplay_handlex(1);
220 #endif
221 	return rv;
222 }
223 
224 bool
225 pmf_system_suspend(PMF_FN_ARGS1)
226 {
227 	device_t curdev;
228 	deviter_t di;
229 
230 	if (!pmf_check_system_drivers())
231 		return false;
232 #if NWSDISPLAY > 0
233 	if (wsdisplay_handlex(0))
234 		return false;
235 #endif
236 	KERNEL_LOCK(1, 0);
237 
238 	/*
239 	 * Flush buffers only if the shutdown didn't do so
240 	 * already and if there was no panic.
241 	 */
242 	if (doing_shutdown == 0 && panicstr == NULL) {
243 		printf("Flushing disk caches: ");
244 		sys_sync(NULL, NULL, NULL);
245 		if (buf_syncwait() != 0)
246 			printf("giving up\n");
247 		else
248 			printf("done\n");
249 	}
250 
251 	aprint_debug("Suspending devices:");
252 
253 	for (curdev = deviter_first(&di, DEVITER_F_LEAVES_FIRST);
254 	     curdev != NULL;
255 	     curdev = deviter_next(&di)) {
256 		if (!device_is_active(curdev))
257 			continue;
258 
259 		aprint_debug(" %s", device_xname(curdev));
260 
261 		/* XXX joerg check return value and abort suspend */
262 		if (!pmf_device_suspend(curdev PMF_FN_CALL))
263 			aprint_debug("(failed)");
264 	}
265 	deviter_release(&di);
266 
267 	aprint_debug(".\n");
268 
269 	return true;
270 }
271 
272 static device_t
273 shutdown_first(struct shutdown_state *s)
274 {
275 	if (!s->initialized) {
276 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
277 		s->initialized = true;
278 	}
279 	return shutdown_next(s);
280 }
281 
282 static device_t
283 shutdown_next(struct shutdown_state *s)
284 {
285 	device_t dv;
286 
287 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
288 		;
289 
290 	return dv;
291 }
292 
293 void
294 pmf_system_shutdown(int how)
295 {
296 	static struct shutdown_state s;
297 	device_t curdev;
298 
299 	aprint_debug("Shutting down devices:");
300 
301 	for (curdev = shutdown_first(&s); curdev != NULL;
302 	     curdev = shutdown_next(&s)) {
303 		aprint_debug(" attempting %s shutdown",
304 		    device_xname(curdev));
305 		if (!device_pmf_is_registered(curdev))
306 			aprint_debug("(skipped)");
307 #if 0 /* needed? */
308 		else if (!device_pmf_class_shutdown(curdev, how))
309 			aprint_debug("(failed)");
310 #endif
311 		else if (!device_pmf_driver_shutdown(curdev, how))
312 			aprint_debug("(failed)");
313 		else if (!device_pmf_bus_shutdown(curdev, how))
314 			aprint_debug("(failed)");
315 	}
316 
317 	aprint_debug(".\n");
318 }
319 
320 bool
321 pmf_set_platform(const char *key, const char *value)
322 {
323 	if (pmf_platform == NULL)
324 		pmf_platform = prop_dictionary_create();
325 	if (pmf_platform == NULL)
326 		return false;
327 
328 	return prop_dictionary_set_cstring(pmf_platform, key, value);
329 }
330 
331 const char *
332 pmf_get_platform(const char *key)
333 {
334 	const char *value;
335 
336 	if (pmf_platform == NULL)
337 		return NULL;
338 
339 	if (!prop_dictionary_get_cstring_nocopy(pmf_platform, key, &value))
340 		return NULL;
341 
342 	return value;
343 }
344 
345 bool
346 pmf_device_register1(device_t dev,
347     bool (*suspend)(device_t PMF_FN_PROTO),
348     bool (*resume)(device_t PMF_FN_PROTO),
349     bool (*shutdown)(device_t, int))
350 {
351 	if (!device_pmf_driver_register(dev, suspend, resume, shutdown))
352 		return false;
353 
354 	if (!device_pmf_driver_child_register(dev)) {
355 		device_pmf_driver_deregister(dev);
356 		return false;
357 	}
358 
359 	return true;
360 }
361 
362 void
363 pmf_device_deregister(device_t dev)
364 {
365 	device_pmf_class_deregister(dev);
366 	device_pmf_bus_deregister(dev);
367 	device_pmf_driver_deregister(dev);
368 }
369 
370 bool
371 pmf_device_suspend_self(device_t dev)
372 {
373 	return pmf_device_suspend(dev, PMF_F_SELF);
374 }
375 
376 bool
377 pmf_device_suspend(device_t dev PMF_FN_ARGS)
378 {
379 	bool rc;
380 
381 	PMF_TRANSITION_PRINTF(("%s: suspend enter\n", device_xname(dev)));
382 	if (!device_pmf_is_registered(dev))
383 		return false;
384 
385 	if (!device_pmf_lock(dev PMF_FN_CALL))
386 		return false;
387 
388 	rc = pmf_device_suspend_locked(dev PMF_FN_CALL);
389 
390 	device_pmf_unlock(dev PMF_FN_CALL);
391 
392 	PMF_TRANSITION_PRINTF(("%s: suspend exit\n", device_xname(dev)));
393 	return rc;
394 }
395 
396 static bool
397 pmf_device_suspend_locked(device_t dev PMF_FN_ARGS)
398 {
399 	PMF_TRANSITION_PRINTF2(1, ("%s: self suspend\n", device_xname(dev)));
400 	device_pmf_self_suspend(dev, flags);
401 	PMF_TRANSITION_PRINTF2(1, ("%s: class suspend\n", device_xname(dev)));
402 	if (!device_pmf_class_suspend(dev PMF_FN_CALL))
403 		return false;
404 	PMF_TRANSITION_PRINTF2(1, ("%s: driver suspend\n", device_xname(dev)));
405 	if (!device_pmf_driver_suspend(dev PMF_FN_CALL))
406 		return false;
407 	PMF_TRANSITION_PRINTF2(1, ("%s: bus suspend\n", device_xname(dev)));
408 	if (!device_pmf_bus_suspend(dev PMF_FN_CALL))
409 		return false;
410 
411 	return true;
412 }
413 
414 bool
415 pmf_device_resume_self(device_t dev)
416 {
417 	return pmf_device_resume(dev, PMF_F_SELF);
418 }
419 
420 bool
421 pmf_device_resume(device_t dev PMF_FN_ARGS)
422 {
423 	bool rc;
424 
425 	PMF_TRANSITION_PRINTF(("%s: resume enter\n", device_xname(dev)));
426 	if (!device_pmf_is_registered(dev))
427 		return false;
428 
429 	if (!device_pmf_lock(dev PMF_FN_CALL))
430 		return false;
431 
432 	rc = pmf_device_resume_locked(dev PMF_FN_CALL);
433 
434 	device_pmf_unlock(dev PMF_FN_CALL);
435 
436 	PMF_TRANSITION_PRINTF(("%s: resume exit\n", device_xname(dev)));
437 	return rc;
438 }
439 
440 static bool
441 pmf_device_resume_locked(device_t dev PMF_FN_ARGS)
442 {
443 	PMF_TRANSITION_PRINTF2(1, ("%s: bus resume\n", device_xname(dev)));
444 	if (!device_pmf_bus_resume(dev PMF_FN_CALL))
445 		return false;
446 	PMF_TRANSITION_PRINTF2(1, ("%s: driver resume\n", device_xname(dev)));
447 	if (!device_pmf_driver_resume(dev PMF_FN_CALL))
448 		return false;
449 	PMF_TRANSITION_PRINTF2(1, ("%s: class resume\n", device_xname(dev)));
450 	if (!device_pmf_class_resume(dev PMF_FN_CALL))
451 		return false;
452 	PMF_TRANSITION_PRINTF2(1, ("%s: self resume\n", device_xname(dev)));
453 	device_pmf_self_resume(dev, flags);
454 
455 	return true;
456 }
457 
458 bool
459 pmf_device_recursive_suspend(device_t dv PMF_FN_ARGS)
460 {
461 	bool rv = true;
462 	device_t curdev;
463 	deviter_t di;
464 
465 	if (!device_is_active(dv))
466 		return true;
467 
468 	for (curdev = deviter_first(&di, 0); curdev != NULL;
469 	     curdev = deviter_next(&di)) {
470 		if (device_parent(curdev) != dv)
471 			continue;
472 		if (!pmf_device_recursive_suspend(curdev PMF_FN_CALL)) {
473 			rv = false;
474 			break;
475 		}
476 	}
477 	deviter_release(&di);
478 
479 	return rv && pmf_device_suspend(dv PMF_FN_CALL);
480 }
481 
482 bool
483 pmf_device_recursive_resume(device_t dv PMF_FN_ARGS)
484 {
485 	device_t parent;
486 
487 	if (device_is_active(dv))
488 		return true;
489 
490 	parent = device_parent(dv);
491 	if (parent != NULL) {
492 		if (!pmf_device_recursive_resume(parent PMF_FN_CALL))
493 			return false;
494 	}
495 
496 	return pmf_device_resume(dv PMF_FN_CALL);
497 }
498 
499 bool
500 pmf_device_resume_subtree(device_t dv PMF_FN_ARGS)
501 {
502 	bool rv = true;
503 	device_t curdev;
504 	deviter_t di;
505 
506 	if (!pmf_device_recursive_resume(dv PMF_FN_CALL))
507 		return false;
508 
509 	for (curdev = deviter_first(&di, 0); curdev != NULL;
510 	     curdev = deviter_next(&di)) {
511 		if (device_parent(curdev) != dv)
512 			continue;
513 		if (!pmf_device_resume_subtree(curdev PMF_FN_CALL)) {
514 			rv = false;
515 			break;
516 		}
517 	}
518 	deviter_release(&di);
519 	return rv;
520 }
521 
522 #include <net/if.h>
523 
524 static bool
525 pmf_class_network_suspend(device_t dev PMF_FN_ARGS)
526 {
527 	struct ifnet *ifp = device_pmf_class_private(dev);
528 	int s;
529 
530 	s = splnet();
531 	(*ifp->if_stop)(ifp, 0);
532 	splx(s);
533 
534 	return true;
535 }
536 
537 static bool
538 pmf_class_network_resume(device_t dev PMF_FN_ARGS)
539 {
540 	struct ifnet *ifp = device_pmf_class_private(dev);
541 	int s;
542 
543 	if ((flags & PMF_F_SELF) != 0)
544 		return true;
545 
546 	s = splnet();
547 	if (ifp->if_flags & IFF_UP) {
548 		ifp->if_flags &= ~IFF_RUNNING;
549 		if ((*ifp->if_init)(ifp) != 0)
550 			aprint_normal_ifnet(ifp, "resume failed\n");
551 		(*ifp->if_start)(ifp);
552 	}
553 	splx(s);
554 
555 	return true;
556 }
557 
558 void
559 pmf_class_network_register(device_t dev, struct ifnet *ifp)
560 {
561 	device_pmf_class_register(dev, ifp, pmf_class_network_suspend,
562 	    pmf_class_network_resume, NULL);
563 }
564 
565 bool
566 pmf_event_inject(device_t dv, pmf_generic_event_t ev)
567 {
568 	pmf_event_workitem_t *pew;
569 
570 	pew = malloc(sizeof(pmf_event_workitem_t), M_TEMP, M_NOWAIT);
571 	if (pew == NULL) {
572 		PMF_EVENT_PRINTF(("%s: PMF event %d dropped (no memory)\n",
573 		    dv ? device_xname(dv) : "<anonymous>", ev));
574 		return false;
575 	}
576 
577 	pew->pew_event = ev;
578 	pew->pew_device = dv;
579 
580 	workqueue_enqueue(pmf_event_workqueue, (void *)pew, NULL);
581 	PMF_EVENT_PRINTF(("%s: PMF event %d injected\n",
582 	    dv ? device_xname(dv) : "<anonymous>", ev));
583 
584 	return true;
585 }
586 
587 bool
588 pmf_event_register(device_t dv, pmf_generic_event_t ev,
589     void (*handler)(device_t), bool global)
590 {
591 	pmf_event_handler_t *event;
592 
593 	event = malloc(sizeof(*event), M_DEVBUF, M_WAITOK);
594 	event->pmf_event = ev;
595 	event->pmf_handler = handler;
596 	event->pmf_device = dv;
597 	event->pmf_global = global;
598 	TAILQ_INSERT_TAIL(&pmf_all_events, event, pmf_link);
599 
600 	return true;
601 }
602 
603 void
604 pmf_event_deregister(device_t dv, pmf_generic_event_t ev,
605     void (*handler)(device_t), bool global)
606 {
607 	pmf_event_handler_t *event;
608 
609 	TAILQ_FOREACH(event, &pmf_all_events, pmf_link) {
610 		if (event->pmf_event != ev)
611 			continue;
612 		if (event->pmf_device != dv)
613 			continue;
614 		if (event->pmf_global != global)
615 			continue;
616 		if (event->pmf_handler != handler)
617 			continue;
618 		TAILQ_REMOVE(&pmf_all_events, event, pmf_link);
619 		free(event, M_DEVBUF);
620 		return;
621 	}
622 }
623 
624 struct display_class_softc {
625 	TAILQ_ENTRY(display_class_softc) dc_link;
626 	device_t dc_dev;
627 };
628 
629 static TAILQ_HEAD(, display_class_softc) all_displays;
630 static callout_t global_idle_counter;
631 static int idle_timeout = 30;
632 
633 static void
634 input_idle(void *dummy)
635 {
636 	PMF_IDLE_PRINTF(("Input idle handler called\n"));
637 	pmf_event_inject(NULL, PMFE_DISPLAY_OFF);
638 }
639 
640 static void
641 input_activity_handler(device_t dv, devactive_t type)
642 {
643 	if (!TAILQ_EMPTY(&all_displays))
644 		callout_schedule(&global_idle_counter, idle_timeout * hz);
645 }
646 
647 static void
648 pmf_class_input_deregister(device_t dv)
649 {
650 	device_active_deregister(dv, input_activity_handler);
651 }
652 
653 bool
654 pmf_class_input_register(device_t dv)
655 {
656 	if (!device_active_register(dv, input_activity_handler))
657 		return false;
658 
659 	device_pmf_class_register(dv, NULL, NULL, NULL,
660 	    pmf_class_input_deregister);
661 
662 	return true;
663 }
664 
665 static void
666 pmf_class_display_deregister(device_t dv)
667 {
668 	struct display_class_softc *sc = device_pmf_class_private(dv);
669 	int s;
670 
671 	s = splsoftclock();
672 	TAILQ_REMOVE(&all_displays, sc, dc_link);
673 	if (TAILQ_EMPTY(&all_displays))
674 		callout_stop(&global_idle_counter);
675 	splx(s);
676 
677 	free(sc, M_DEVBUF);
678 }
679 
680 bool
681 pmf_class_display_register(device_t dv)
682 {
683 	struct display_class_softc *sc;
684 	int s;
685 
686 	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK);
687 
688 	s = splsoftclock();
689 	if (TAILQ_EMPTY(&all_displays))
690 		callout_schedule(&global_idle_counter, idle_timeout * hz);
691 
692 	TAILQ_INSERT_HEAD(&all_displays, sc, dc_link);
693 	splx(s);
694 
695 	device_pmf_class_register(dv, sc, NULL, NULL,
696 	    pmf_class_display_deregister);
697 
698 	return true;
699 }
700 
701 void
702 pmf_init(void)
703 {
704 	int err;
705 
706 	KASSERT(pmf_event_workqueue == NULL);
707 	err = workqueue_create(&pmf_event_workqueue, "pmfevent",
708 	    pmf_event_worker, NULL, PRI_NONE, IPL_VM, 0);
709 	if (err)
710 		panic("couldn't create pmfevent workqueue");
711 
712 	callout_init(&global_idle_counter, 0);
713 	callout_setfunc(&global_idle_counter, input_idle, NULL);
714 }
715