2 * Copyright (c) 1997, Stefan Esser <se@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
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.
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.
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
35 #include <sys/cpuset.h>
36 #include <sys/rtprio.h>
37 #include <sys/systm.h>
38 #include <sys/interrupt.h>
39 #include <sys/kernel.h>
40 #include <sys/kthread.h>
42 #include <sys/limits.h>
44 #include <sys/malloc.h>
45 #include <sys/mutex.h>
48 #include <sys/random.h>
49 #include <sys/resourcevar.h>
50 #include <sys/sched.h>
52 #include <sys/sysctl.h>
53 #include <sys/syslog.h>
54 #include <sys/unistd.h>
55 #include <sys/vmmeter.h>
56 #include <machine/atomic.h>
57 #include <machine/cpu.h>
58 #include <machine/md_var.h>
59 #include <machine/stdarg.h>
62 #include <ddb/db_sym.h>
66 * Describe an interrupt thread. There is one of these per interrupt event.
69 struct intr_event *it_event;
70 struct thread *it_thread; /* Kernel thread. */
71 int it_flags; /* (j) IT_* flags. */
72 int it_need; /* Needs service. */
75 /* Interrupt thread flags kept in it_flags */
76 #define IT_DEAD 0x000001 /* Thread is waiting to exit. */
83 struct intr_event *clk_intr_event;
84 struct intr_event *tty_intr_event;
86 struct proc *intrproc;
88 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads");
90 static int intr_storm_threshold = 1000;
91 TUNABLE_INT("hw.intr_storm_threshold", &intr_storm_threshold);
92 SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RW,
93 &intr_storm_threshold, 0,
94 "Number of consecutive interrupts before storm protection is enabled");
95 static TAILQ_HEAD(, intr_event) event_list =
96 TAILQ_HEAD_INITIALIZER(event_list);
97 static struct mtx event_lock;
98 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF);
100 static void intr_event_update(struct intr_event *ie);
102 static int intr_event_schedule_thread(struct intr_event *ie,
103 struct intr_thread *ithd);
104 static int intr_filter_loop(struct intr_event *ie,
105 struct trapframe *frame, struct intr_thread **ithd);
106 static struct intr_thread *ithread_create(const char *name,
107 struct intr_handler *ih);
109 static int intr_event_schedule_thread(struct intr_event *ie);
110 static struct intr_thread *ithread_create(const char *name);
112 static void ithread_destroy(struct intr_thread *ithread);
113 static void ithread_execute_handlers(struct proc *p,
114 struct intr_event *ie);
116 static void priv_ithread_execute_handler(struct proc *p,
117 struct intr_handler *ih);
119 static void ithread_loop(void *);
120 static void ithread_update(struct intr_thread *ithd);
121 static void start_softintr(void *);
123 /* Map an interrupt type to an ithread priority. */
125 intr_priority(enum intr_type flags)
129 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET |
130 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV);
137 * XXX We need to refine this. BSD/OS distinguishes
138 * between tape and disk priorities.
146 pri = PI_DISK; /* XXX or PI_CAM? */
148 case INTR_TYPE_AV: /* Audio/video */
155 pri = PI_DULL; /* don't care */
158 /* We didn't specify an interrupt level. */
159 panic("intr_priority: no interrupt type in flags");
166 * Update an ithread based on the associated intr_event.
169 ithread_update(struct intr_thread *ithd)
171 struct intr_event *ie;
176 td = ithd->it_thread;
178 /* Determine the overall priority of this event. */
179 if (TAILQ_EMPTY(&ie->ie_handlers))
182 pri = TAILQ_FIRST(&ie->ie_handlers)->ih_pri;
184 /* Update name and priority. */
185 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name));
192 * Regenerate the full name of an interrupt event and update its priority.
195 intr_event_update(struct intr_event *ie)
197 struct intr_handler *ih;
201 /* Start off with no entropy and just the name of the event. */
202 mtx_assert(&ie->ie_lock, MA_OWNED);
203 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
204 ie->ie_flags &= ~IE_ENTROPY;
208 /* Run through all the handlers updating values. */
209 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
210 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 <
211 sizeof(ie->ie_fullname)) {
212 strcat(ie->ie_fullname, " ");
213 strcat(ie->ie_fullname, ih->ih_name);
217 if (ih->ih_flags & IH_ENTROPY)
218 ie->ie_flags |= IE_ENTROPY;
222 * If the handler names were too long, add +'s to indicate missing
223 * names. If we run out of room and still have +'s to add, change
224 * the last character from a + to a *.
226 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2];
227 while (missed-- > 0) {
228 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) {
235 strcat(ie->ie_fullname, " +");
238 strcat(ie->ie_fullname, "+");
242 * If this event has an ithread, update it's priority and
245 if (ie->ie_thread != NULL)
246 ithread_update(ie->ie_thread);
247 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname);
251 intr_event_create(struct intr_event **event, void *source, int flags, int irq,
252 void (*pre_ithread)(void *), void (*post_ithread)(void *),
253 void (*post_filter)(void *), int (*assign_cpu)(void *, u_char),
254 const char *fmt, ...)
256 struct intr_event *ie;
259 /* The only valid flag during creation is IE_SOFT. */
260 if ((flags & ~IE_SOFT) != 0)
262 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO);
263 ie->ie_source = source;
264 ie->ie_pre_ithread = pre_ithread;
265 ie->ie_post_ithread = post_ithread;
266 ie->ie_post_filter = post_filter;
267 ie->ie_assign_cpu = assign_cpu;
268 ie->ie_flags = flags;
271 TAILQ_INIT(&ie->ie_handlers);
272 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF);
275 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap);
277 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
278 mtx_lock(&event_lock);
279 TAILQ_INSERT_TAIL(&event_list, ie, ie_list);
280 mtx_unlock(&event_lock);
283 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name);
288 * Bind an interrupt event to the specified CPU. Note that not all
289 * platforms support binding an interrupt to a CPU. For those
290 * platforms this request will fail. For supported platforms, any
291 * associated ithreads as well as the primary interrupt context will
292 * be bound to the specificed CPU. Using a cpu id of NOCPU unbinds
293 * the interrupt event.
296 intr_event_bind(struct intr_event *ie, u_char cpu)
302 /* Need a CPU to bind to. */
303 if (cpu != NOCPU && CPU_ABSENT(cpu))
306 if (ie->ie_assign_cpu == NULL)
309 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR);
314 * If we have any ithreads try to set their mask first to verify
317 mtx_lock(&ie->ie_lock);
318 if (ie->ie_thread != NULL) {
321 CPU_COPY(cpuset_root, &mask);
324 id = ie->ie_thread->it_thread->td_tid;
325 mtx_unlock(&ie->ie_lock);
326 error = cpuset_setthread(id, &mask);
330 mtx_unlock(&ie->ie_lock);
331 error = ie->ie_assign_cpu(ie->ie_source, cpu);
333 mtx_lock(&ie->ie_lock);
334 if (ie->ie_thread != NULL) {
336 if (ie->ie_cpu == NOCPU)
337 CPU_COPY(cpuset_root, &mask);
340 id = ie->ie_thread->it_thread->td_tid;
341 mtx_unlock(&ie->ie_lock);
342 (void)cpuset_setthread(id, &mask);
344 mtx_unlock(&ie->ie_lock);
348 mtx_lock(&ie->ie_lock);
350 mtx_unlock(&ie->ie_lock);
355 static struct intr_event *
358 struct intr_event *ie;
360 mtx_lock(&event_lock);
361 TAILQ_FOREACH(ie, &event_list, ie_list)
362 if (ie->ie_irq == irq &&
363 (ie->ie_flags & IE_SOFT) == 0 &&
364 TAILQ_FIRST(&ie->ie_handlers) != NULL)
366 mtx_unlock(&event_lock);
371 intr_setaffinity(int irq, void *m)
373 struct intr_event *ie;
381 * If we're setting all cpus we can unbind. Otherwise make sure
382 * only one cpu is in the set.
384 if (CPU_CMP(cpuset_root, mask)) {
385 for (n = 0; n < CPU_SETSIZE; n++) {
386 if (!CPU_ISSET(n, mask))
393 ie = intr_lookup(irq);
396 return (intr_event_bind(ie, cpu));
400 intr_getaffinity(int irq, void *m)
402 struct intr_event *ie;
406 ie = intr_lookup(irq);
410 mtx_lock(&ie->ie_lock);
411 if (ie->ie_cpu == NOCPU)
412 CPU_COPY(cpuset_root, mask);
414 CPU_SET(ie->ie_cpu, mask);
415 mtx_unlock(&ie->ie_lock);
420 intr_event_destroy(struct intr_event *ie)
423 mtx_lock(&event_lock);
424 mtx_lock(&ie->ie_lock);
425 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
426 mtx_unlock(&ie->ie_lock);
427 mtx_unlock(&event_lock);
430 TAILQ_REMOVE(&event_list, ie, ie_list);
432 if (ie->ie_thread != NULL) {
433 ithread_destroy(ie->ie_thread);
434 ie->ie_thread = NULL;
437 mtx_unlock(&ie->ie_lock);
438 mtx_unlock(&event_lock);
439 mtx_destroy(&ie->ie_lock);
445 static struct intr_thread *
446 ithread_create(const char *name)
448 struct intr_thread *ithd;
452 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
454 error = kproc_kthread_add(ithread_loop, ithd, &intrproc,
455 &td, RFSTOPPED | RFHIGHPID,
456 0, "intr", "%s", name);
458 panic("kproc_create() failed with %d", error);
460 sched_class(td, PRI_ITHD);
463 td->td_pflags |= TDP_ITHREAD;
464 ithd->it_thread = td;
465 CTR2(KTR_INTR, "%s: created %s", __func__, name);
469 static struct intr_thread *
470 ithread_create(const char *name, struct intr_handler *ih)
472 struct intr_thread *ithd;
476 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
478 error = kproc_kthread_add(ithread_loop, ih, &intrproc,
479 &td, RFSTOPPED | RFHIGHPID,
480 0, "intr", "%s", name);
482 panic("kproc_create() failed with %d", error);
484 sched_class(td, PRI_ITHD);
487 td->td_pflags |= TDP_ITHREAD;
488 ithd->it_thread = td;
489 CTR2(KTR_INTR, "%s: created %s", __func__, name);
495 ithread_destroy(struct intr_thread *ithread)
499 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name);
500 td = ithread->it_thread;
502 ithread->it_flags |= IT_DEAD;
503 if (TD_AWAITING_INTR(td)) {
505 sched_add(td, SRQ_INTR);
512 intr_event_add_handler(struct intr_event *ie, const char *name,
513 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
514 enum intr_type flags, void **cookiep)
516 struct intr_handler *ih, *temp_ih;
517 struct intr_thread *it;
519 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
522 /* Allocate and populate an interrupt handler structure. */
523 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
524 ih->ih_filter = filter;
525 ih->ih_handler = handler;
526 ih->ih_argument = arg;
530 if (flags & INTR_EXCL)
531 ih->ih_flags = IH_EXCLUSIVE;
532 if (flags & INTR_MPSAFE)
533 ih->ih_flags |= IH_MPSAFE;
534 if (flags & INTR_ENTROPY)
535 ih->ih_flags |= IH_ENTROPY;
537 /* We can only have one exclusive handler in a event. */
538 mtx_lock(&ie->ie_lock);
539 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
540 if ((flags & INTR_EXCL) ||
541 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
542 mtx_unlock(&ie->ie_lock);
548 /* Add the new handler to the event in priority order. */
549 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
550 if (temp_ih->ih_pri > ih->ih_pri)
554 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
556 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
557 intr_event_update(ie);
559 /* Create a thread if we need one. */
560 while (ie->ie_thread == NULL && handler != NULL) {
561 if (ie->ie_flags & IE_ADDING_THREAD)
562 msleep(ie, &ie->ie_lock, 0, "ithread", 0);
564 ie->ie_flags |= IE_ADDING_THREAD;
565 mtx_unlock(&ie->ie_lock);
566 it = ithread_create("intr: newborn");
567 mtx_lock(&ie->ie_lock);
568 ie->ie_flags &= ~IE_ADDING_THREAD;
575 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
577 mtx_unlock(&ie->ie_lock);
585 intr_event_add_handler(struct intr_event *ie, const char *name,
586 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
587 enum intr_type flags, void **cookiep)
589 struct intr_handler *ih, *temp_ih;
590 struct intr_thread *it;
592 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
595 /* Allocate and populate an interrupt handler structure. */
596 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
597 ih->ih_filter = filter;
598 ih->ih_handler = handler;
599 ih->ih_argument = arg;
603 if (flags & INTR_EXCL)
604 ih->ih_flags = IH_EXCLUSIVE;
605 if (flags & INTR_MPSAFE)
606 ih->ih_flags |= IH_MPSAFE;
607 if (flags & INTR_ENTROPY)
608 ih->ih_flags |= IH_ENTROPY;
610 /* We can only have one exclusive handler in a event. */
611 mtx_lock(&ie->ie_lock);
612 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
613 if ((flags & INTR_EXCL) ||
614 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
615 mtx_unlock(&ie->ie_lock);
621 /* Add the new handler to the event in priority order. */
622 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
623 if (temp_ih->ih_pri > ih->ih_pri)
627 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
629 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
630 intr_event_update(ie);
632 /* For filtered handlers, create a private ithread to run on. */
633 if (filter != NULL && handler != NULL) {
634 mtx_unlock(&ie->ie_lock);
635 it = ithread_create("intr: newborn", ih);
636 mtx_lock(&ie->ie_lock);
639 ithread_update(it); // XXX - do we really need this?!?!?
640 } else { /* Create the global per-event thread if we need one. */
641 while (ie->ie_thread == NULL && handler != NULL) {
642 if (ie->ie_flags & IE_ADDING_THREAD)
643 msleep(ie, &ie->ie_lock, 0, "ithread", 0);
645 ie->ie_flags |= IE_ADDING_THREAD;
646 mtx_unlock(&ie->ie_lock);
647 it = ithread_create("intr: newborn", ih);
648 mtx_lock(&ie->ie_lock);
649 ie->ie_flags &= ~IE_ADDING_THREAD;
657 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
659 mtx_unlock(&ie->ie_lock);
668 * Return the ie_source field from the intr_event an intr_handler is
672 intr_handler_source(void *cookie)
674 struct intr_handler *ih;
675 struct intr_event *ie;
677 ih = (struct intr_handler *)cookie;
682 ("interrupt handler \"%s\" has a NULL interrupt event",
684 return (ie->ie_source);
689 intr_event_remove_handler(void *cookie)
691 struct intr_handler *handler = (struct intr_handler *)cookie;
692 struct intr_event *ie;
694 struct intr_handler *ih;
702 ie = handler->ih_event;
704 ("interrupt handler \"%s\" has a NULL interrupt event",
706 mtx_lock(&ie->ie_lock);
707 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
710 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
713 mtx_unlock(&ie->ie_lock);
714 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
715 ih->ih_name, ie->ie_name);
719 * If there is no ithread, then just remove the handler and return.
720 * XXX: Note that an INTR_FAST handler might be running on another
723 if (ie->ie_thread == NULL) {
724 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
725 mtx_unlock(&ie->ie_lock);
726 free(handler, M_ITHREAD);
731 * If the interrupt thread is already running, then just mark this
732 * handler as being dead and let the ithread do the actual removal.
734 * During a cold boot while cold is set, msleep() does not sleep,
735 * so we have to remove the handler here rather than letting the
738 thread_lock(ie->ie_thread->it_thread);
739 if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) {
740 handler->ih_flags |= IH_DEAD;
743 * Ensure that the thread will process the handler list
744 * again and remove this handler if it has already passed
747 ie->ie_thread->it_need = 1;
749 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
750 thread_unlock(ie->ie_thread->it_thread);
751 while (handler->ih_flags & IH_DEAD)
752 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
753 intr_event_update(ie);
756 * XXX: This could be bad in the case of ppbus(8). Also, I think
757 * this could lead to races of stale data when servicing an
761 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
762 if (!(ih->ih_flags & IH_FAST)) {
768 ithread_destroy(ie->ie_thread);
769 ie->ie_thread = NULL;
772 mtx_unlock(&ie->ie_lock);
773 free(handler, M_ITHREAD);
778 intr_event_schedule_thread(struct intr_event *ie)
780 struct intr_entropy entropy;
781 struct intr_thread *it;
787 * If no ithread or no handlers, then we have a stray interrupt.
789 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) ||
790 ie->ie_thread == NULL)
799 * If any of the handlers for this ithread claim to be good
800 * sources of entropy, then gather some.
802 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
803 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
804 p->p_pid, td->td_name);
805 entropy.event = (uintptr_t)ie;
807 random_harvest(&entropy, sizeof(entropy), 2, 0,
811 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
814 * Set it_need to tell the thread to keep running if it is already
815 * running. Then, lock the thread and see if we actually need to
816 * put it on the runqueue.
820 if (TD_AWAITING_INTR(td)) {
821 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
824 sched_add(td, SRQ_INTR);
826 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
827 __func__, p->p_pid, td->td_name, it->it_need, td->td_state);
835 intr_event_remove_handler(void *cookie)
837 struct intr_handler *handler = (struct intr_handler *)cookie;
838 struct intr_event *ie;
839 struct intr_thread *it;
841 struct intr_handler *ih;
849 ie = handler->ih_event;
851 ("interrupt handler \"%s\" has a NULL interrupt event",
853 mtx_lock(&ie->ie_lock);
854 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
857 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
860 mtx_unlock(&ie->ie_lock);
861 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
862 ih->ih_name, ie->ie_name);
866 * If there are no ithreads (per event and per handler), then
867 * just remove the handler and return.
868 * XXX: Note that an INTR_FAST handler might be running on another CPU!
870 if (ie->ie_thread == NULL && handler->ih_thread == NULL) {
871 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
872 mtx_unlock(&ie->ie_lock);
873 free(handler, M_ITHREAD);
877 /* Private or global ithread? */
878 it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread;
880 * If the interrupt thread is already running, then just mark this
881 * handler as being dead and let the ithread do the actual removal.
883 * During a cold boot while cold is set, msleep() does not sleep,
884 * so we have to remove the handler here rather than letting the
887 thread_lock(it->it_thread);
888 if (!TD_AWAITING_INTR(it->it_thread) && !cold) {
889 handler->ih_flags |= IH_DEAD;
892 * Ensure that the thread will process the handler list
893 * again and remove this handler if it has already passed
898 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
899 thread_unlock(it->it_thread);
900 while (handler->ih_flags & IH_DEAD)
901 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
903 * At this point, the handler has been disconnected from the event,
904 * so we can kill the private ithread if any.
906 if (handler->ih_thread) {
907 ithread_destroy(handler->ih_thread);
908 handler->ih_thread = NULL;
910 intr_event_update(ie);
913 * XXX: This could be bad in the case of ppbus(8). Also, I think
914 * this could lead to races of stale data when servicing an
918 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
919 if (handler != NULL) {
925 ithread_destroy(ie->ie_thread);
926 ie->ie_thread = NULL;
929 mtx_unlock(&ie->ie_lock);
930 free(handler, M_ITHREAD);
935 intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it)
937 struct intr_entropy entropy;
943 * If no ithread or no handlers, then we have a stray interrupt.
945 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || it == NULL)
953 * If any of the handlers for this ithread claim to be good
954 * sources of entropy, then gather some.
956 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
957 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
958 p->p_pid, td->td_name);
959 entropy.event = (uintptr_t)ie;
961 random_harvest(&entropy, sizeof(entropy), 2, 0,
965 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
968 * Set it_need to tell the thread to keep running if it is already
969 * running. Then, lock the thread and see if we actually need to
970 * put it on the runqueue.
974 if (TD_AWAITING_INTR(td)) {
975 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
978 sched_add(td, SRQ_INTR);
980 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
981 __func__, p->p_pid, td->td_name, it->it_need, td->td_state);
990 * Allow interrupt event binding for software interrupt handlers -- a no-op,
991 * since interrupts are generated in software rather than being directed by
995 swi_assign_cpu(void *arg, u_char cpu)
1002 * Add a software interrupt handler to a specified event. If a given event
1003 * is not specified, then a new event is created.
1006 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler,
1007 void *arg, int pri, enum intr_type flags, void **cookiep)
1009 struct intr_event *ie;
1012 if (flags & INTR_ENTROPY)
1015 ie = (eventp != NULL) ? *eventp : NULL;
1018 if (!(ie->ie_flags & IE_SOFT))
1021 error = intr_event_create(&ie, NULL, IE_SOFT, 0,
1022 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri);
1028 error = intr_event_add_handler(ie, name, NULL, handler, arg,
1029 (pri * RQ_PPQ) + PI_SOFT, flags, cookiep);
1032 if (pri == SWI_CLOCK) {
1034 p = ie->ie_thread->it_thread->td_proc;
1036 p->p_flag |= P_NOLOAD;
1043 * Schedule a software interrupt thread.
1046 swi_sched(void *cookie, int flags)
1048 struct intr_handler *ih = (struct intr_handler *)cookie;
1049 struct intr_event *ie = ih->ih_event;
1052 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name,
1056 * Set ih_need for this handler so that if the ithread is already
1057 * running it will execute this handler on the next pass. Otherwise,
1058 * it will execute it the next time it runs.
1060 atomic_store_rel_int(&ih->ih_need, 1);
1062 if (!(flags & SWI_DELAY)) {
1063 PCPU_INC(cnt.v_soft);
1065 error = intr_event_schedule_thread(ie, ie->ie_thread);
1067 error = intr_event_schedule_thread(ie);
1069 KASSERT(error == 0, ("stray software interrupt"));
1074 * Remove a software interrupt handler. Currently this code does not
1075 * remove the associated interrupt event if it becomes empty. Calling code
1076 * may do so manually via intr_event_destroy(), but that's not really
1077 * an optimal interface.
1080 swi_remove(void *cookie)
1083 return (intr_event_remove_handler(cookie));
1088 priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih)
1090 struct intr_event *ie;
1094 * If this handler is marked for death, remove it from
1095 * the list of handlers and wake up the sleeper.
1097 if (ih->ih_flags & IH_DEAD) {
1098 mtx_lock(&ie->ie_lock);
1099 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
1100 ih->ih_flags &= ~IH_DEAD;
1102 mtx_unlock(&ie->ie_lock);
1106 /* Execute this handler. */
1107 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1108 __func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument,
1109 ih->ih_name, ih->ih_flags);
1111 if (!(ih->ih_flags & IH_MPSAFE))
1113 ih->ih_handler(ih->ih_argument);
1114 if (!(ih->ih_flags & IH_MPSAFE))
1120 * This is a public function for use by drivers that mux interrupt
1121 * handlers for child devices from their interrupt handler.
1124 intr_event_execute_handlers(struct proc *p, struct intr_event *ie)
1126 struct intr_handler *ih, *ihn;
1128 TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) {
1130 * If this handler is marked for death, remove it from
1131 * the list of handlers and wake up the sleeper.
1133 if (ih->ih_flags & IH_DEAD) {
1134 mtx_lock(&ie->ie_lock);
1135 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
1136 ih->ih_flags &= ~IH_DEAD;
1138 mtx_unlock(&ie->ie_lock);
1142 /* Skip filter only handlers */
1143 if (ih->ih_handler == NULL)
1147 * For software interrupt threads, we only execute
1148 * handlers that have their need flag set. Hardware
1149 * interrupt threads always invoke all of their handlers.
1151 if (ie->ie_flags & IE_SOFT) {
1155 atomic_store_rel_int(&ih->ih_need, 0);
1158 /* Execute this handler. */
1159 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1160 __func__, p->p_pid, (void *)ih->ih_handler,
1161 ih->ih_argument, ih->ih_name, ih->ih_flags);
1163 if (!(ih->ih_flags & IH_MPSAFE))
1165 ih->ih_handler(ih->ih_argument);
1166 if (!(ih->ih_flags & IH_MPSAFE))
1172 ithread_execute_handlers(struct proc *p, struct intr_event *ie)
1175 /* Interrupt handlers should not sleep. */
1176 if (!(ie->ie_flags & IE_SOFT))
1177 THREAD_NO_SLEEPING();
1178 intr_event_execute_handlers(p, ie);
1179 if (!(ie->ie_flags & IE_SOFT))
1180 THREAD_SLEEPING_OK();
1183 * Interrupt storm handling:
1185 * If this interrupt source is currently storming, then throttle
1186 * it to only fire the handler once per clock tick.
1188 * If this interrupt source is not currently storming, but the
1189 * number of back to back interrupts exceeds the storm threshold,
1190 * then enter storming mode.
1192 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold &&
1193 !(ie->ie_flags & IE_SOFT)) {
1194 /* Report the message only once every second. */
1195 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) {
1197 "interrupt storm detected on \"%s\"; throttling interrupt source\n",
1205 * Now that all the handlers have had a chance to run, reenable
1206 * the interrupt source.
1208 if (ie->ie_post_ithread != NULL)
1209 ie->ie_post_ithread(ie->ie_source);
1214 * This is the main code for interrupt threads.
1217 ithread_loop(void *arg)
1219 struct intr_thread *ithd;
1220 struct intr_event *ie;
1226 ithd = (struct intr_thread *)arg;
1227 KASSERT(ithd->it_thread == td,
1228 ("%s: ithread and proc linkage out of sync", __func__));
1229 ie = ithd->it_event;
1233 * As long as we have interrupts outstanding, go through the
1234 * list of handlers, giving each one a go at it.
1238 * If we are an orphaned thread, then just die.
1240 if (ithd->it_flags & IT_DEAD) {
1241 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1242 p->p_pid, td->td_name);
1243 free(ithd, M_ITHREAD);
1248 * Service interrupts. If another interrupt arrives while
1249 * we are running, it will set it_need to note that we
1250 * should make another pass.
1252 while (ithd->it_need) {
1254 * This might need a full read and write barrier
1255 * to make sure that this write posts before any
1256 * of the memory or device accesses in the
1259 atomic_store_rel_int(&ithd->it_need, 0);
1260 ithread_execute_handlers(p, ie);
1262 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1263 mtx_assert(&Giant, MA_NOTOWNED);
1266 * Processed all our interrupts. Now get the sched
1267 * lock. This may take a while and it_need may get
1268 * set again, so we have to check it again.
1271 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) {
1274 mi_switch(SW_VOL | SWT_IWAIT, NULL);
1281 * Main interrupt handling body.
1284 * o ie: the event connected to this interrupt.
1285 * o frame: some archs (i.e. i386) pass a frame to some.
1286 * handlers as their main argument.
1288 * o 0: everything ok.
1289 * o EINVAL: stray interrupt.
1292 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1294 struct intr_handler *ih;
1296 int error, ret, thread;
1300 /* An interrupt with no event or handlers is a stray interrupt. */
1301 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
1305 * Execute fast interrupt handlers directly.
1306 * To support clock handlers, if a handler registers
1307 * with a NULL argument, then we pass it a pointer to
1308 * a trapframe as its argument.
1310 td->td_intr_nesting_level++;
1314 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1315 if (ih->ih_filter == NULL) {
1319 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__,
1320 ih->ih_filter, ih->ih_argument == NULL ? frame :
1321 ih->ih_argument, ih->ih_name);
1322 if (ih->ih_argument == NULL)
1323 ret = ih->ih_filter(frame);
1325 ret = ih->ih_filter(ih->ih_argument);
1327 * Wrapper handler special handling:
1329 * in some particular cases (like pccard and pccbb),
1330 * the _real_ device handler is wrapped in a couple of
1331 * functions - a filter wrapper and an ithread wrapper.
1332 * In this case (and just in this case), the filter wrapper
1333 * could ask the system to schedule the ithread and mask
1334 * the interrupt source if the wrapped handler is composed
1335 * of just an ithread handler.
1337 * TODO: write a generic wrapper to avoid people rolling
1341 if (ret == FILTER_SCHEDULE_THREAD)
1347 if (ie->ie_pre_ithread != NULL)
1348 ie->ie_pre_ithread(ie->ie_source);
1350 if (ie->ie_post_filter != NULL)
1351 ie->ie_post_filter(ie->ie_source);
1354 /* Schedule the ithread if needed. */
1356 error = intr_event_schedule_thread(ie);
1358 KASSERT(error == 0, ("bad stray interrupt"));
1361 log(LOG_WARNING, "bad stray interrupt");
1365 td->td_intr_nesting_level--;
1370 * This is the main code for interrupt threads.
1373 ithread_loop(void *arg)
1375 struct intr_thread *ithd;
1376 struct intr_handler *ih;
1377 struct intr_event *ie;
1384 ih = (struct intr_handler *)arg;
1385 priv = (ih->ih_thread != NULL) ? 1 : 0;
1386 ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread;
1387 KASSERT(ithd->it_thread == td,
1388 ("%s: ithread and proc linkage out of sync", __func__));
1389 ie = ithd->it_event;
1393 * As long as we have interrupts outstanding, go through the
1394 * list of handlers, giving each one a go at it.
1398 * If we are an orphaned thread, then just die.
1400 if (ithd->it_flags & IT_DEAD) {
1401 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1402 p->p_pid, td->td_name);
1403 free(ithd, M_ITHREAD);
1408 * Service interrupts. If another interrupt arrives while
1409 * we are running, it will set it_need to note that we
1410 * should make another pass.
1412 while (ithd->it_need) {
1414 * This might need a full read and write barrier
1415 * to make sure that this write posts before any
1416 * of the memory or device accesses in the
1419 atomic_store_rel_int(&ithd->it_need, 0);
1421 priv_ithread_execute_handler(p, ih);
1423 ithread_execute_handlers(p, ie);
1425 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1426 mtx_assert(&Giant, MA_NOTOWNED);
1429 * Processed all our interrupts. Now get the sched
1430 * lock. This may take a while and it_need may get
1431 * set again, so we have to check it again.
1434 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) {
1437 mi_switch(SW_VOL | SWT_IWAIT, NULL);
1444 * Main loop for interrupt filter.
1446 * Some architectures (i386, amd64 and arm) require the optional frame
1447 * parameter, and use it as the main argument for fast handler execution
1448 * when ih_argument == NULL.
1451 * o FILTER_STRAY: No filter recognized the event, and no
1452 * filter-less handler is registered on this
1454 * o FILTER_HANDLED: A filter claimed the event and served it.
1455 * o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at
1456 * least one filter-less handler on this line.
1457 * o FILTER_HANDLED |
1458 * FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for
1459 * scheduling the per-handler ithread.
1461 * In case an ithread has to be scheduled, in *ithd there will be a
1462 * pointer to a struct intr_thread containing the thread to be
1467 intr_filter_loop(struct intr_event *ie, struct trapframe *frame,
1468 struct intr_thread **ithd)
1470 struct intr_handler *ih;
1472 int ret, thread_only;
1476 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1478 * Execute fast interrupt handlers directly.
1479 * To support clock handlers, if a handler registers
1480 * with a NULL argument, then we pass it a pointer to
1481 * a trapframe as its argument.
1483 arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument);
1485 CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__,
1486 ih->ih_filter, ih->ih_handler, arg, ih->ih_name);
1488 if (ih->ih_filter != NULL)
1489 ret = ih->ih_filter(arg);
1495 if (ret & FILTER_STRAY)
1498 *ithd = ih->ih_thread;
1504 * No filters handled the interrupt and we have at least
1505 * one handler without a filter. In this case, we schedule
1506 * all of the filter-less handlers to run in the ithread.
1509 *ithd = ie->ie_thread;
1510 return (FILTER_SCHEDULE_THREAD);
1512 return (FILTER_STRAY);
1516 * Main interrupt handling body.
1519 * o ie: the event connected to this interrupt.
1520 * o frame: some archs (i.e. i386) pass a frame to some.
1521 * handlers as their main argument.
1523 * o 0: everything ok.
1524 * o EINVAL: stray interrupt.
1527 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1529 struct intr_thread *ithd;
1536 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
1539 td->td_intr_nesting_level++;
1542 thread = intr_filter_loop(ie, frame, &ithd);
1543 if (thread & FILTER_HANDLED) {
1544 if (ie->ie_post_filter != NULL)
1545 ie->ie_post_filter(ie->ie_source);
1547 if (ie->ie_pre_ithread != NULL)
1548 ie->ie_pre_ithread(ie->ie_source);
1552 /* Interrupt storm logic */
1553 if (thread & FILTER_STRAY) {
1555 if (ie->ie_count < intr_storm_threshold)
1556 printf("Interrupt stray detection not present\n");
1559 /* Schedule an ithread if needed. */
1560 if (thread & FILTER_SCHEDULE_THREAD) {
1561 if (intr_event_schedule_thread(ie, ithd) != 0)
1562 panic("%s: impossible stray interrupt", __func__);
1564 td->td_intr_nesting_level--;
1571 * Dump details about an interrupt handler
1574 db_dump_intrhand(struct intr_handler *ih)
1578 db_printf("\t%-10s ", ih->ih_name);
1579 switch (ih->ih_pri) {
1604 if (ih->ih_pri >= PI_SOFT)
1607 db_printf("%4u", ih->ih_pri);
1611 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC);
1612 db_printf("(%p)", ih->ih_argument);
1614 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD |
1618 if (ih->ih_flags & IH_EXCLUSIVE) {
1624 if (ih->ih_flags & IH_ENTROPY) {
1627 db_printf("ENTROPY");
1630 if (ih->ih_flags & IH_DEAD) {
1636 if (ih->ih_flags & IH_MPSAFE) {
1639 db_printf("MPSAFE");
1653 * Dump details about a event.
1656 db_dump_intr_event(struct intr_event *ie, int handlers)
1658 struct intr_handler *ih;
1659 struct intr_thread *it;
1662 db_printf("%s ", ie->ie_fullname);
1665 db_printf("(pid %d)", it->it_thread->td_proc->p_pid);
1667 db_printf("(no thread)");
1668 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 ||
1669 (it != NULL && it->it_need)) {
1672 if (ie->ie_flags & IE_SOFT) {
1676 if (ie->ie_flags & IE_ENTROPY) {
1679 db_printf("ENTROPY");
1682 if (ie->ie_flags & IE_ADDING_THREAD) {
1685 db_printf("ADDING_THREAD");
1688 if (it != NULL && it->it_need) {
1698 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
1699 db_dump_intrhand(ih);
1703 * Dump data about interrupt handlers
1705 DB_SHOW_COMMAND(intr, db_show_intr)
1707 struct intr_event *ie;
1710 verbose = index(modif, 'v') != NULL;
1711 all = index(modif, 'a') != NULL;
1712 TAILQ_FOREACH(ie, &event_list, ie_list) {
1713 if (!all && TAILQ_EMPTY(&ie->ie_handlers))
1715 db_dump_intr_event(ie, verbose);
1723 * Start standard software interrupt threads
1726 start_softintr(void *dummy)
1729 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih))
1730 panic("died while creating vm swi ithread");
1732 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr,
1736 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
1737 * The data for this machine dependent, and the declarations are in machine
1738 * dependent code. The layout of intrnames and intrcnt however is machine
1741 * We do not know the length of intrcnt and intrnames at compile time, so
1742 * calculate things at run time.
1745 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
1747 return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames,
1751 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
1752 NULL, 0, sysctl_intrnames, "", "Interrupt Names");
1755 sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
1757 return (sysctl_handle_opaque(oidp, intrcnt,
1758 (char *)eintrcnt - (char *)intrcnt, req));
1761 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
1762 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
1766 * DDB command to dump the interrupt statistics.
1768 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt)
1774 for (i = intrcnt; i != eintrcnt && !db_pager_quit; i++) {
1778 db_printf("%s\t%lu\n", cp, *i);
1779 cp += strlen(cp) + 1;