kern_intr.c revision 133191 
1/*
2 * Copyright (c) 1997, Stefan Esser <se@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/kern/kern_intr.c 133191 2004-08-06 03:39:28Z rwatson $");
29
30#include "opt_ddb.h"
31
32#include <sys/param.h>
33#include <sys/bus.h>
34#include <sys/conf.h>
35#include <sys/rtprio.h>
36#include <sys/systm.h>
37#include <sys/interrupt.h>
38#include <sys/kernel.h>
39#include <sys/kthread.h>
40#include <sys/ktr.h>
41#include <sys/limits.h>
42#include <sys/lock.h>
43#include <sys/malloc.h>
44#include <sys/mutex.h>
45#include <sys/proc.h>
46#include <sys/random.h>
47#include <sys/resourcevar.h>
48#include <sys/sysctl.h>
49#include <sys/unistd.h>
50#include <sys/vmmeter.h>
51#include <machine/atomic.h>
52#include <machine/cpu.h>
53#include <machine/md_var.h>
54#include <machine/stdarg.h>
55#ifdef DDB
56#include <ddb/ddb.h>
57#include <ddb/db_sym.h>
58#endif
59
60struct	int_entropy {
61	struct	proc *proc;
62	uintptr_t vector;
63};
64
65struct	ithd *clk_ithd;
66struct	ithd *tty_ithd;
67void	*softclock_ih;
68void	*vm_ih;
69
70static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads");
71
72static int intr_storm_threshold = 500;
73TUNABLE_INT("hw.intr_storm_threshold", &intr_storm_threshold);
74SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RW,
75    &intr_storm_threshold, 0,
76    "Number of consecutive interrupts before storm protection is enabled");
77
78static void	ithread_loop(void *);
79static void	ithread_update(struct ithd *);
80static void	start_softintr(void *);
81
82u_char
83ithread_priority(enum intr_type flags)
84{
85	u_char pri;
86
87	flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET |
88	    INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV);
89	switch (flags) {
90	case INTR_TYPE_TTY:
91		pri = PI_TTYLOW;
92		break;
93	case INTR_TYPE_BIO:
94		/*
95		 * XXX We need to refine this.  BSD/OS distinguishes
96		 * between tape and disk priorities.
97		 */
98		pri = PI_DISK;
99		break;
100	case INTR_TYPE_NET:
101		pri = PI_NET;
102		break;
103	case INTR_TYPE_CAM:
104		pri = PI_DISK;          /* XXX or PI_CAM? */
105		break;
106	case INTR_TYPE_AV:		/* Audio/video */
107		pri = PI_AV;
108		break;
109	case INTR_TYPE_CLK:
110		pri = PI_REALTIME;
111		break;
112	case INTR_TYPE_MISC:
113		pri = PI_DULL;          /* don't care */
114		break;
115	default:
116		/* We didn't specify an interrupt level. */
117		panic("ithread_priority: no interrupt type in flags");
118	}
119
120	return pri;
121}
122
123/*
124 * Regenerate the name (p_comm) and priority for a threaded interrupt thread.
125 */
126static void
127ithread_update(struct ithd *ithd)
128{
129	struct intrhand *ih;
130	struct thread *td;
131	struct proc *p;
132	int entropy;
133
134	mtx_assert(&ithd->it_lock, MA_OWNED);
135	td = ithd->it_td;
136	if (td == NULL)
137		return;
138	p = td->td_proc;
139
140	strlcpy(p->p_comm, ithd->it_name, sizeof(p->p_comm));
141
142	ih = TAILQ_FIRST(&ithd->it_handlers);
143	if (ih == NULL) {
144		mtx_lock_spin(&sched_lock);
145		td->td_priority = PRI_MAX_ITHD;
146		td->td_base_pri = PRI_MAX_ITHD;
147		mtx_unlock_spin(&sched_lock);
148		ithd->it_flags &= ~IT_ENTROPY;
149		return;
150	}
151	entropy = 0;
152	mtx_lock_spin(&sched_lock);
153	td->td_priority = ih->ih_pri;
154	td->td_base_pri = ih->ih_pri;
155	mtx_unlock_spin(&sched_lock);
156	TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next) {
157		if (strlen(p->p_comm) + strlen(ih->ih_name) + 1 <
158		    sizeof(p->p_comm)) {
159			strcat(p->p_comm, " ");
160			strcat(p->p_comm, ih->ih_name);
161		} else if (strlen(p->p_comm) + 1 == sizeof(p->p_comm)) {
162			if (p->p_comm[sizeof(p->p_comm) - 2] == '+')
163				p->p_comm[sizeof(p->p_comm) - 2] = '*';
164			else
165				p->p_comm[sizeof(p->p_comm) - 2] = '+';
166		} else
167			strcat(p->p_comm, "+");
168		if (ih->ih_flags & IH_ENTROPY)
169			entropy++;
170	}
171	if (entropy)
172		ithd->it_flags |= IT_ENTROPY;
173	else
174		ithd->it_flags &= ~IT_ENTROPY;
175	CTR2(KTR_INTR, "%s: updated %s", __func__, p->p_comm);
176}
177
178int
179ithread_create(struct ithd **ithread, uintptr_t vector, int flags,
180    void (*disable)(uintptr_t), void (*enable)(uintptr_t), const char *fmt, ...)
181{
182	struct ithd *ithd;
183	struct thread *td;
184	struct proc *p;
185	int error;
186	va_list ap;
187
188	/* The only valid flag during creation is IT_SOFT. */
189	if ((flags & ~IT_SOFT) != 0)
190		return (EINVAL);
191
192	ithd = malloc(sizeof(struct ithd), M_ITHREAD, M_WAITOK | M_ZERO);
193	ithd->it_vector = vector;
194	ithd->it_disable = disable;
195	ithd->it_enable = enable;
196	ithd->it_flags = flags;
197	TAILQ_INIT(&ithd->it_handlers);
198	mtx_init(&ithd->it_lock, "ithread", NULL, MTX_DEF);
199
200	va_start(ap, fmt);
201	vsnprintf(ithd->it_name, sizeof(ithd->it_name), fmt, ap);
202	va_end(ap);
203
204	error = kthread_create(ithread_loop, ithd, &p, RFSTOPPED | RFHIGHPID,
205	    0, "%s", ithd->it_name);
206	if (error) {
207		mtx_destroy(&ithd->it_lock);
208		free(ithd, M_ITHREAD);
209		return (error);
210	}
211	td = FIRST_THREAD_IN_PROC(p);	/* XXXKSE */
212	mtx_lock_spin(&sched_lock);
213	td->td_ksegrp->kg_pri_class = PRI_ITHD;
214	td->td_priority = PRI_MAX_ITHD;
215	TD_SET_IWAIT(td);
216	mtx_unlock_spin(&sched_lock);
217	ithd->it_td = td;
218	td->td_ithd = ithd;
219	if (ithread != NULL)
220		*ithread = ithd;
221	CTR2(KTR_INTR, "%s: created %s", __func__, ithd->it_name);
222	return (0);
223}
224
225int
226ithread_destroy(struct ithd *ithread)
227{
228
229	struct thread *td;
230	if (ithread == NULL)
231		return (EINVAL);
232
233	td = ithread->it_td;
234	mtx_lock(&ithread->it_lock);
235	if (!TAILQ_EMPTY(&ithread->it_handlers)) {
236		mtx_unlock(&ithread->it_lock);
237		return (EINVAL);
238	}
239	ithread->it_flags |= IT_DEAD;
240	mtx_lock_spin(&sched_lock);
241	if (TD_AWAITING_INTR(td)) {
242		TD_CLR_IWAIT(td);
243		setrunqueue(td);
244	}
245	mtx_unlock_spin(&sched_lock);
246	mtx_unlock(&ithread->it_lock);
247	CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_name);
248	return (0);
249}
250
251int
252ithread_add_handler(struct ithd* ithread, const char *name,
253    driver_intr_t handler, void *arg, u_char pri, enum intr_type flags,
254    void **cookiep)
255{
256	struct intrhand *ih, *temp_ih;
257
258	if (ithread == NULL || name == NULL || handler == NULL)
259		return (EINVAL);
260
261	ih = malloc(sizeof(struct intrhand), M_ITHREAD, M_WAITOK | M_ZERO);
262	ih->ih_handler = handler;
263	ih->ih_argument = arg;
264	ih->ih_name = name;
265	ih->ih_ithread = ithread;
266	ih->ih_pri = pri;
267	if (flags & INTR_FAST)
268		ih->ih_flags = IH_FAST;
269	else if (flags & INTR_EXCL)
270		ih->ih_flags = IH_EXCLUSIVE;
271	if (flags & INTR_MPSAFE)
272		ih->ih_flags |= IH_MPSAFE;
273	if (flags & INTR_ENTROPY)
274		ih->ih_flags |= IH_ENTROPY;
275
276	mtx_lock(&ithread->it_lock);
277	if ((flags & INTR_EXCL) != 0 && !TAILQ_EMPTY(&ithread->it_handlers))
278		goto fail;
279	if (!TAILQ_EMPTY(&ithread->it_handlers)) {
280		temp_ih = TAILQ_FIRST(&ithread->it_handlers);
281		if (temp_ih->ih_flags & IH_EXCLUSIVE)
282			goto fail;
283		if ((ih->ih_flags & IH_FAST) && !(temp_ih->ih_flags & IH_FAST))
284			goto fail;
285		if (!(ih->ih_flags & IH_FAST) && (temp_ih->ih_flags & IH_FAST))
286			goto fail;
287	}
288
289	TAILQ_FOREACH(temp_ih, &ithread->it_handlers, ih_next)
290	    if (temp_ih->ih_pri > ih->ih_pri)
291		    break;
292	if (temp_ih == NULL)
293		TAILQ_INSERT_TAIL(&ithread->it_handlers, ih, ih_next);
294	else
295		TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
296	ithread_update(ithread);
297	mtx_unlock(&ithread->it_lock);
298
299	if (cookiep != NULL)
300		*cookiep = ih;
301	CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
302	    ithread->it_name);
303	return (0);
304
305fail:
306	mtx_unlock(&ithread->it_lock);
307	free(ih, M_ITHREAD);
308	return (EINVAL);
309}
310
311int
312ithread_remove_handler(void *cookie)
313{
314	struct intrhand *handler = (struct intrhand *)cookie;
315	struct ithd *ithread;
316#ifdef INVARIANTS
317	struct intrhand *ih;
318#endif
319
320	if (handler == NULL)
321		return (EINVAL);
322	ithread = handler->ih_ithread;
323	KASSERT(ithread != NULL,
324	    ("interrupt handler \"%s\" has a NULL interrupt thread",
325		handler->ih_name));
326	CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
327	    ithread->it_name);
328	mtx_lock(&ithread->it_lock);
329#ifdef INVARIANTS
330	TAILQ_FOREACH(ih, &ithread->it_handlers, ih_next)
331		if (ih == handler)
332			goto ok;
333	mtx_unlock(&ithread->it_lock);
334	panic("interrupt handler \"%s\" not found in interrupt thread \"%s\"",
335	    ih->ih_name, ithread->it_name);
336ok:
337#endif
338	/*
339	 * If the interrupt thread is already running, then just mark this
340	 * handler as being dead and let the ithread do the actual removal.
341	 *
342	 * During a cold boot while cold is set, msleep() does not sleep,
343	 * so we have to remove the handler here rather than letting the
344	 * thread do it.
345	 */
346	mtx_lock_spin(&sched_lock);
347	if (!TD_AWAITING_INTR(ithread->it_td) && !cold) {
348		handler->ih_flags |= IH_DEAD;
349
350		/*
351		 * Ensure that the thread will process the handler list
352		 * again and remove this handler if it has already passed
353		 * it on the list.
354		 */
355		ithread->it_need = 1;
356	} else
357		TAILQ_REMOVE(&ithread->it_handlers, handler, ih_next);
358	mtx_unlock_spin(&sched_lock);
359	if ((handler->ih_flags & IH_DEAD) != 0)
360		msleep(handler, &ithread->it_lock, PUSER, "itrmh", 0);
361	ithread_update(ithread);
362	mtx_unlock(&ithread->it_lock);
363	free(handler, M_ITHREAD);
364	return (0);
365}
366
367int
368ithread_schedule(struct ithd *ithread)
369{
370	struct int_entropy entropy;
371	struct thread *td;
372	struct thread *ctd;
373	struct proc *p;
374
375	/*
376	 * If no ithread or no handlers, then we have a stray interrupt.
377	 */
378	if ((ithread == NULL) || TAILQ_EMPTY(&ithread->it_handlers))
379		return (EINVAL);
380
381	ctd = curthread;
382	td = ithread->it_td;
383	p = td->td_proc;
384	/*
385	 * If any of the handlers for this ithread claim to be good
386	 * sources of entropy, then gather some.
387	 */
388	if (harvest.interrupt && ithread->it_flags & IT_ENTROPY) {
389		CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
390		    p->p_pid, p->p_comm);
391		entropy.vector = ithread->it_vector;
392		entropy.proc = ctd->td_proc;
393		random_harvest(&entropy, sizeof(entropy), 2, 0,
394		    RANDOM_INTERRUPT);
395	}
396
397	KASSERT(p != NULL, ("ithread %s has no process", ithread->it_name));
398	CTR4(KTR_INTR, "%s: pid %d: (%s) need = %d",
399	    __func__, p->p_pid, p->p_comm, ithread->it_need);
400
401	/*
402	 * Set it_need to tell the thread to keep running if it is already
403	 * running.  Then, grab sched_lock and see if we actually need to
404	 * put this thread on the runqueue.
405	 */
406	ithread->it_need = 1;
407	mtx_lock_spin(&sched_lock);
408	if (TD_AWAITING_INTR(td)) {
409		CTR2(KTR_INTR, "%s: setrunqueue %d", __func__, p->p_pid);
410		TD_CLR_IWAIT(td);
411		setrunqueue(td);
412	} else {
413		CTR4(KTR_INTR, "%s: pid %d: it_need %d, state %d",
414		    __func__, p->p_pid, ithread->it_need, td->td_state);
415	}
416	mtx_unlock_spin(&sched_lock);
417
418	return (0);
419}
420
421int
422swi_add(struct ithd **ithdp, const char *name, driver_intr_t handler,
423	    void *arg, int pri, enum intr_type flags, void **cookiep)
424{
425	struct ithd *ithd;
426	int error;
427
428	if (flags & (INTR_FAST | INTR_ENTROPY))
429		return (EINVAL);
430
431	ithd = (ithdp != NULL) ? *ithdp : NULL;
432
433	if (ithd != NULL) {
434		if ((ithd->it_flags & IT_SOFT) == 0)
435			return(EINVAL);
436	} else {
437		error = ithread_create(&ithd, pri, IT_SOFT, NULL, NULL,
438		    "swi%d:", pri);
439		if (error)
440			return (error);
441
442		if (ithdp != NULL)
443			*ithdp = ithd;
444	}
445	return (ithread_add_handler(ithd, name, handler, arg,
446		    (pri * RQ_PPQ) + PI_SOFT, flags, cookiep));
447}
448
449
450/*
451 * Schedule a heavyweight software interrupt process.
452 */
453void
454swi_sched(void *cookie, int flags)
455{
456	struct intrhand *ih = (struct intrhand *)cookie;
457	struct ithd *it = ih->ih_ithread;
458	int error;
459
460	atomic_add_int(&cnt.v_intr, 1); /* one more global interrupt */
461
462	CTR3(KTR_INTR, "swi_sched pid %d(%s) need=%d",
463		it->it_td->td_proc->p_pid, it->it_td->td_proc->p_comm, it->it_need);
464
465	/*
466	 * Set ih_need for this handler so that if the ithread is already
467	 * running it will execute this handler on the next pass.  Otherwise,
468	 * it will execute it the next time it runs.
469	 */
470	atomic_store_rel_int(&ih->ih_need, 1);
471	if (!(flags & SWI_DELAY)) {
472		error = ithread_schedule(it);
473		KASSERT(error == 0, ("stray software interrupt"));
474	}
475}
476
477/*
478 * This is the main code for interrupt threads.
479 */
480static void
481ithread_loop(void *arg)
482{
483	struct ithd *ithd;		/* our thread context */
484	struct intrhand *ih;		/* and our interrupt handler chain */
485	struct thread *td;
486	struct proc *p;
487	int count, warming, warned;
488
489	td = curthread;
490	p = td->td_proc;
491	ithd = (struct ithd *)arg;	/* point to myself */
492	KASSERT(ithd->it_td == td && td->td_ithd == ithd,
493	    ("%s: ithread and proc linkage out of sync", __func__));
494	warming = 10 * intr_storm_threshold;
495	warned = 0;
496
497	/*
498	 * As long as we have interrupts outstanding, go through the
499	 * list of handlers, giving each one a go at it.
500	 */
501	for (;;) {
502		/*
503		 * If we are an orphaned thread, then just die.
504		 */
505		if (ithd->it_flags & IT_DEAD) {
506			CTR3(KTR_INTR, "%s: pid %d: (%s) exiting", __func__,
507			    p->p_pid, p->p_comm);
508			td->td_ithd = NULL;
509			mtx_destroy(&ithd->it_lock);
510			free(ithd, M_ITHREAD);
511			kthread_exit(0);
512		}
513
514		CTR4(KTR_INTR, "%s: pid %d: (%s) need=%d", __func__,
515		     p->p_pid, p->p_comm, ithd->it_need);
516		count = 0;
517		while (ithd->it_need) {
518			/*
519			 * Service interrupts.  If another interrupt
520			 * arrives while we are running, they will set
521			 * it_need to denote that we should make
522			 * another pass.
523			 */
524			atomic_store_rel_int(&ithd->it_need, 0);
525restart:
526			TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next) {
527				if (ithd->it_flags & IT_SOFT && !ih->ih_need)
528					continue;
529				atomic_store_rel_int(&ih->ih_need, 0);
530				CTR6(KTR_INTR,
531				    "%s: pid %d ih=%p: %p(%p) flg=%x", __func__,
532				    p->p_pid, (void *)ih,
533				    (void *)ih->ih_handler, ih->ih_argument,
534				    ih->ih_flags);
535
536				if ((ih->ih_flags & IH_DEAD) != 0) {
537					mtx_lock(&ithd->it_lock);
538					TAILQ_REMOVE(&ithd->it_handlers, ih,
539					    ih_next);
540					wakeup(ih);
541					mtx_unlock(&ithd->it_lock);
542					goto restart;
543				}
544				if ((ih->ih_flags & IH_MPSAFE) == 0)
545					mtx_lock(&Giant);
546				ih->ih_handler(ih->ih_argument);
547				if ((ih->ih_flags & IH_MPSAFE) == 0)
548					mtx_unlock(&Giant);
549			}
550			if (ithd->it_enable != NULL) {
551				ithd->it_enable(ithd->it_vector);
552
553				/*
554				 * Storm detection needs a delay here
555				 * to see slightly delayed interrupts
556				 * on some machines, but we don't
557				 * want to always delay, so only delay
558				 * while warming up.
559				 */
560				if (warming != 0) {
561					DELAY(1);
562					--warming;
563				}
564			}
565
566			/*
567			 * If we detect an interrupt storm, sleep until
568			 * the next hardclock tick.  We sleep at the
569			 * end of the loop instead of at the beginning
570			 * to ensure that we see slightly delayed
571			 * interrupts.
572			 */
573			if (count >= intr_storm_threshold) {
574				if (!warned) {
575					printf(
576	"Interrupt storm detected on \"%s\"; throttling interrupt source\n",
577					    p->p_comm);
578					warned = 1;
579				}
580				tsleep(&count, td->td_priority, "istorm", 1);
581
582				/*
583				 * Fudge the count to re-throttle if the
584				 * interrupt is still active.  Our storm
585				 * detection is too primitive to detect
586				 * whether the storm has gone away
587				 * reliably, even if we were to waste a
588				 * lot of time spinning for the next
589				 * intr_storm_threshold interrupts, so
590				 * we assume that the storm hasn't gone
591				 * away unless the interrupt repeats
592				 * less often the hardclock interrupt.
593				 */
594				count = INT_MAX - 1;
595			}
596			count++;
597		}
598		WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
599		mtx_assert(&Giant, MA_NOTOWNED);
600
601		/*
602		 * Processed all our interrupts.  Now get the sched
603		 * lock.  This may take a while and it_need may get
604		 * set again, so we have to check it again.
605		 */
606		mtx_lock_spin(&sched_lock);
607		if (!ithd->it_need) {
608			TD_SET_IWAIT(td);
609			CTR2(KTR_INTR, "%s: pid %d: done", __func__, p->p_pid);
610			mi_switch(SW_VOL, NULL);
611			CTR2(KTR_INTR, "%s: pid %d: resumed", __func__, p->p_pid);
612		}
613		mtx_unlock_spin(&sched_lock);
614	}
615}
616
617#ifdef DDB
618/*
619 * Dump details about an interrupt handler
620 */
621static void
622db_dump_intrhand(struct intrhand *ih)
623{
624	int comma;
625
626	db_printf("\t%-10s ", ih->ih_name);
627	switch (ih->ih_pri) {
628	case PI_REALTIME:
629		db_printf("CLK ");
630		break;
631	case PI_AV:
632		db_printf("AV  ");
633		break;
634	case PI_TTYHIGH:
635	case PI_TTYLOW:
636		db_printf("TTY ");
637		break;
638	case PI_TAPE:
639		db_printf("TAPE");
640		break;
641	case PI_NET:
642		db_printf("NET ");
643		break;
644	case PI_DISK:
645	case PI_DISKLOW:
646		db_printf("DISK");
647		break;
648	case PI_DULL:
649		db_printf("DULL");
650		break;
651	default:
652		if (ih->ih_pri >= PI_SOFT)
653			db_printf("SWI ");
654		else
655			db_printf("%4u", ih->ih_pri);
656		break;
657	}
658	db_printf(" ");
659	db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC);
660	db_printf("(%p)", ih->ih_argument);
661	if (ih->ih_need ||
662	    (ih->ih_flags & (IH_FAST | IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD |
663	    IH_MPSAFE)) != 0) {
664		db_printf(" {");
665		comma = 0;
666		if (ih->ih_flags & IH_FAST) {
667			db_printf("FAST");
668			comma = 1;
669		}
670		if (ih->ih_flags & IH_EXCLUSIVE) {
671			if (comma)
672				db_printf(", ");
673			db_printf("EXCL");
674			comma = 1;
675		}
676		if (ih->ih_flags & IH_ENTROPY) {
677			if (comma)
678				db_printf(", ");
679			db_printf("ENTROPY");
680			comma = 1;
681		}
682		if (ih->ih_flags & IH_DEAD) {
683			if (comma)
684				db_printf(", ");
685			db_printf("DEAD");
686			comma = 1;
687		}
688		if (ih->ih_flags & IH_MPSAFE) {
689			if (comma)
690				db_printf(", ");
691			db_printf("MPSAFE");
692			comma = 1;
693		}
694		if (ih->ih_need) {
695			if (comma)
696				db_printf(", ");
697			db_printf("NEED");
698		}
699		db_printf("}");
700	}
701	db_printf("\n");
702}
703
704/*
705 * Dump details about an ithread
706 */
707void
708db_dump_ithread(struct ithd *ithd, int handlers)
709{
710	struct proc *p;
711	struct intrhand *ih;
712	int comma;
713
714	if (ithd->it_td != NULL) {
715		p = ithd->it_td->td_proc;
716		db_printf("%s (pid %d)", p->p_comm, p->p_pid);
717	} else
718		db_printf("%s: (no thread)", ithd->it_name);
719	if ((ithd->it_flags & (IT_SOFT | IT_ENTROPY | IT_DEAD)) != 0 ||
720	    ithd->it_need) {
721		db_printf(" {");
722		comma = 0;
723		if (ithd->it_flags & IT_SOFT) {
724			db_printf("SOFT");
725			comma = 1;
726		}
727		if (ithd->it_flags & IT_ENTROPY) {
728			if (comma)
729				db_printf(", ");
730			db_printf("ENTROPY");
731			comma = 1;
732		}
733		if (ithd->it_flags & IT_DEAD) {
734			if (comma)
735				db_printf(", ");
736			db_printf("DEAD");
737			comma = 1;
738		}
739		if (ithd->it_need) {
740			if (comma)
741				db_printf(", ");
742			db_printf("NEED");
743		}
744		db_printf("}");
745	}
746	db_printf("\n");
747
748	if (handlers)
749		TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next)
750		    db_dump_intrhand(ih);
751}
752#endif /* DDB */
753
754/*
755 * Start standard software interrupt threads
756 */
757static void
758start_softintr(void *dummy)
759{
760	struct proc *p;
761
762	if (swi_add(&clk_ithd, "clock", softclock, NULL, SWI_CLOCK,
763		INTR_MPSAFE, &softclock_ih) ||
764	    swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih))
765		panic("died while creating standard software ithreads");
766
767	p = clk_ithd->it_td->td_proc;
768	PROC_LOCK(p);
769	p->p_flag |= P_NOLOAD;
770	PROC_UNLOCK(p);
771}
772SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, NULL)
773
774/*
775 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
776 * The data for this machine dependent, and the declarations are in machine
777 * dependent code.  The layout of intrnames and intrcnt however is machine
778 * independent.
779 *
780 * We do not know the length of intrcnt and intrnames at compile time, so
781 * calculate things at run time.
782 */
783static int
784sysctl_intrnames(SYSCTL_HANDLER_ARGS)
785{
786	return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames,
787	   req));
788}
789
790SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
791    NULL, 0, sysctl_intrnames, "", "Interrupt Names");
792
793static int
794sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
795{
796	return (sysctl_handle_opaque(oidp, intrcnt,
797	    (char *)eintrcnt - (char *)intrcnt, req));
798}
799
800SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
801    NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
802
803#ifdef DDB
804/*
805 * DDB command to dump the interrupt statistics.
806 */
807DB_SHOW_COMMAND(intrcnt, db_show_intrcnt)
808{
809	u_long *i;
810	char *cp;
811	int quit;
812
813	cp = intrnames;
814	db_setup_paging(db_simple_pager, &quit, DB_LINES_PER_PAGE);
815	for (i = intrcnt, quit = 0; i != eintrcnt && !quit; i++) {
816		if (*cp == '\0')
817			break;
818		if (*i != 0)
819			db_printf("%s\t%lu\n", cp, *i);
820		cp += strlen(cp) + 1;
821	}
822}
823#endif
824