2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 1997, Stefan Esser <se@freebsd.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice unmodified, this list of conditions, and the following
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/cdefs.h>
31 #include "opt_hwpmc_hooks.h"
32 #include "opt_kstack_usage_prof.h"
34 #include <sys/param.h>
37 #include <sys/cpuset.h>
38 #include <sys/rtprio.h>
39 #include <sys/systm.h>
40 #include <sys/interrupt.h>
41 #include <sys/kernel.h>
42 #include <sys/kthread.h>
44 #include <sys/limits.h>
46 #include <sys/malloc.h>
47 #include <sys/mutex.h>
50 #include <sys/epoch.h>
51 #include <sys/random.h>
52 #include <sys/resourcevar.h>
53 #include <sys/sched.h>
55 #include <sys/sysctl.h>
56 #include <sys/syslog.h>
57 #include <sys/unistd.h>
58 #include <sys/vmmeter.h>
59 #include <machine/atomic.h>
60 #include <machine/cpu.h>
61 #include <machine/md_var.h>
62 #include <machine/smp.h>
63 #include <machine/stdarg.h>
66 #include <ddb/db_sym.h>
70 * Describe an interrupt thread. There is one of these per interrupt event.
73 struct intr_event *it_event;
74 struct thread *it_thread; /* Kernel thread. */
75 int it_flags; /* (j) IT_* flags. */
76 int it_need; /* Needs service. */
77 int it_waiting; /* Waiting in the runq. */
80 /* Interrupt thread flags kept in it_flags */
81 #define IT_DEAD 0x000001 /* Thread is waiting to exit. */
82 #define IT_WAIT 0x000002 /* Thread is waiting for completion. */
89 struct intr_event *clk_intr_event;
90 struct proc *intrproc;
92 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads");
94 static int intr_storm_threshold = 0;
95 SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RWTUN,
96 &intr_storm_threshold, 0,
97 "Number of consecutive interrupts before storm protection is enabled");
98 static int intr_epoch_batch = 1000;
99 SYSCTL_INT(_hw, OID_AUTO, intr_epoch_batch, CTLFLAG_RWTUN, &intr_epoch_batch,
100 0, "Maximum interrupt handler executions without re-entering epoch(9)");
102 static int intr_hwpmc_waiting_report_threshold = 1;
103 SYSCTL_INT(_hw, OID_AUTO, intr_hwpmc_waiting_report_threshold, CTLFLAG_RWTUN,
104 &intr_hwpmc_waiting_report_threshold, 1,
105 "Threshold for reporting number of events in a workq");
106 #define PMC_HOOK_INSTALLED_ANY() __predict_false(pmc_hook != NULL)
108 static TAILQ_HEAD(, intr_event) event_list =
109 TAILQ_HEAD_INITIALIZER(event_list);
110 static struct mtx event_lock;
111 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF);
113 static void intr_event_update(struct intr_event *ie);
114 static int intr_event_schedule_thread(struct intr_event *ie, struct trapframe *frame);
115 static struct intr_thread *ithread_create(const char *name);
116 static void ithread_destroy(struct intr_thread *ithread);
117 static void ithread_execute_handlers(struct proc *p,
118 struct intr_event *ie);
119 static void ithread_loop(void *);
120 static void ithread_update(struct intr_thread *ithd);
121 static void start_softintr(void *);
124 #include <sys/pmckern.h>
125 PMC_SOFT_DEFINE( , , intr, all);
126 PMC_SOFT_DEFINE( , , intr, ithread);
127 PMC_SOFT_DEFINE( , , intr, filter);
128 PMC_SOFT_DEFINE( , , intr, stray);
129 PMC_SOFT_DEFINE( , , intr, schedule);
130 PMC_SOFT_DEFINE( , , intr, waiting);
132 #define PMC_SOFT_CALL_INTR_HLPR(event, frame) \
135 PMC_SOFT_CALL_TF( , , intr, event, frame); \
137 PMC_SOFT_CALL( , , intr, event); \
141 /* Map an interrupt type to an ithread priority. */
143 intr_priority(enum intr_type flags)
147 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET |
148 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV);
169 pri = PI_DULL; /* don't care */
172 /* We didn't specify an interrupt level. */
173 panic("intr_priority: no interrupt type in flags");
180 * Update an ithread based on the associated intr_event.
183 ithread_update(struct intr_thread *ithd)
185 struct intr_event *ie;
190 td = ithd->it_thread;
191 mtx_assert(&ie->ie_lock, MA_OWNED);
193 /* Determine the overall priority of this event. */
194 if (CK_SLIST_EMPTY(&ie->ie_handlers))
197 pri = CK_SLIST_FIRST(&ie->ie_handlers)->ih_pri;
199 /* Update name and priority. */
200 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name));
202 sched_clear_tdname(td);
205 sched_ithread_prio(td, pri);
210 * Regenerate the full name of an interrupt event and update its priority.
213 intr_event_update(struct intr_event *ie)
215 struct intr_handler *ih;
217 int missed, space, flags;
219 /* Start off with no entropy and just the name of the event. */
220 mtx_assert(&ie->ie_lock, MA_OWNED);
221 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
226 /* Run through all the handlers updating values. */
227 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) {
228 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 <
229 sizeof(ie->ie_fullname)) {
230 strcat(ie->ie_fullname, " ");
231 strcat(ie->ie_fullname, ih->ih_name);
235 flags |= ih->ih_flags;
237 ie->ie_hflags = flags;
240 * If there is only one handler and its name is too long, just copy in
241 * as much of the end of the name (includes the unit number) as will
242 * fit. Otherwise, we have multiple handlers and not all of the names
243 * will fit. Add +'s to indicate missing names. If we run out of room
244 * and still have +'s to add, change the last character from a + to a *.
246 if (missed == 1 && space == 1) {
247 ih = CK_SLIST_FIRST(&ie->ie_handlers);
248 missed = strlen(ie->ie_fullname) + strlen(ih->ih_name) + 2 -
249 sizeof(ie->ie_fullname);
250 strcat(ie->ie_fullname, (missed == 0) ? " " : "-");
251 strcat(ie->ie_fullname, &ih->ih_name[missed]);
254 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2];
255 while (missed-- > 0) {
256 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) {
263 strcat(ie->ie_fullname, " +");
266 strcat(ie->ie_fullname, "+");
270 * If this event has an ithread, update it's priority and
273 if (ie->ie_thread != NULL)
274 ithread_update(ie->ie_thread);
275 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname);
279 intr_event_create(struct intr_event **event, void *source, int flags, int irq,
280 void (*pre_ithread)(void *), void (*post_ithread)(void *),
281 void (*post_filter)(void *), int (*assign_cpu)(void *, int),
282 const char *fmt, ...)
284 struct intr_event *ie;
287 /* The only valid flag during creation is IE_SOFT. */
288 if ((flags & ~IE_SOFT) != 0)
290 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO);
291 ie->ie_source = source;
292 ie->ie_pre_ithread = pre_ithread;
293 ie->ie_post_ithread = post_ithread;
294 ie->ie_post_filter = post_filter;
295 ie->ie_assign_cpu = assign_cpu;
296 ie->ie_flags = flags;
299 CK_SLIST_INIT(&ie->ie_handlers);
300 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF);
303 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap);
305 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
306 mtx_lock(&event_lock);
307 TAILQ_INSERT_TAIL(&event_list, ie, ie_list);
308 mtx_unlock(&event_lock);
311 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name);
316 * Bind an interrupt event to the specified CPU. Note that not all
317 * platforms support binding an interrupt to a CPU. For those
318 * platforms this request will fail. Using a cpu id of NOCPU unbinds
319 * the interrupt event.
322 _intr_event_bind(struct intr_event *ie, int cpu, bool bindirq, bool bindithread)
327 /* Need a CPU to bind to. */
328 if (cpu != NOCPU && CPU_ABSENT(cpu))
331 if (ie->ie_assign_cpu == NULL)
334 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR);
339 * If we have any ithreads try to set their mask first to verify
343 mtx_lock(&ie->ie_lock);
344 if (ie->ie_thread != NULL) {
345 id = ie->ie_thread->it_thread->td_tid;
346 mtx_unlock(&ie->ie_lock);
347 error = cpuset_setithread(id, cpu);
351 mtx_unlock(&ie->ie_lock);
354 error = ie->ie_assign_cpu(ie->ie_source, cpu);
357 mtx_lock(&ie->ie_lock);
358 if (ie->ie_thread != NULL) {
360 id = ie->ie_thread->it_thread->td_tid;
361 mtx_unlock(&ie->ie_lock);
362 (void)cpuset_setithread(id, cpu);
364 mtx_unlock(&ie->ie_lock);
370 mtx_lock(&ie->ie_lock);
372 mtx_unlock(&ie->ie_lock);
379 * Bind an interrupt event to the specified CPU. For supported platforms, any
380 * associated ithreads as well as the primary interrupt context will be bound
381 * to the specificed CPU.
384 intr_event_bind(struct intr_event *ie, int cpu)
387 return (_intr_event_bind(ie, cpu, true, true));
391 * Bind an interrupt event to the specified CPU, but do not bind associated
395 intr_event_bind_irqonly(struct intr_event *ie, int cpu)
398 return (_intr_event_bind(ie, cpu, true, false));
402 * Bind an interrupt event's ithread to the specified CPU.
405 intr_event_bind_ithread(struct intr_event *ie, int cpu)
408 return (_intr_event_bind(ie, cpu, false, true));
412 * Bind an interrupt event's ithread to the specified cpuset.
415 intr_event_bind_ithread_cpuset(struct intr_event *ie, cpuset_t *cs)
419 mtx_lock(&ie->ie_lock);
420 if (ie->ie_thread != NULL) {
421 id = ie->ie_thread->it_thread->td_tid;
422 mtx_unlock(&ie->ie_lock);
423 return (cpuset_setthread(id, cs));
425 mtx_unlock(&ie->ie_lock);
430 static struct intr_event *
433 struct intr_event *ie;
435 mtx_lock(&event_lock);
436 TAILQ_FOREACH(ie, &event_list, ie_list)
437 if (ie->ie_irq == irq &&
438 (ie->ie_flags & IE_SOFT) == 0 &&
439 CK_SLIST_FIRST(&ie->ie_handlers) != NULL)
441 mtx_unlock(&event_lock);
446 intr_setaffinity(int irq, int mode, void *m)
448 struct intr_event *ie;
455 * If we're setting all cpus we can unbind. Otherwise make sure
456 * only one cpu is in the set.
458 if (CPU_CMP(cpuset_root, mask)) {
459 for (n = 0; n < CPU_SETSIZE; n++) {
460 if (!CPU_ISSET(n, mask))
467 ie = intr_lookup(irq);
472 return (intr_event_bind(ie, cpu));
473 case CPU_WHICH_INTRHANDLER:
474 return (intr_event_bind_irqonly(ie, cpu));
475 case CPU_WHICH_ITHREAD:
476 return (intr_event_bind_ithread(ie, cpu));
483 intr_getaffinity(int irq, int mode, void *m)
485 struct intr_event *ie;
493 ie = intr_lookup(irq);
501 case CPU_WHICH_INTRHANDLER:
502 mtx_lock(&ie->ie_lock);
503 if (ie->ie_cpu == NOCPU)
504 CPU_COPY(cpuset_root, mask);
506 CPU_SET(ie->ie_cpu, mask);
507 mtx_unlock(&ie->ie_lock);
509 case CPU_WHICH_ITHREAD:
510 mtx_lock(&ie->ie_lock);
511 if (ie->ie_thread == NULL) {
512 mtx_unlock(&ie->ie_lock);
513 CPU_COPY(cpuset_root, mask);
515 id = ie->ie_thread->it_thread->td_tid;
516 mtx_unlock(&ie->ie_lock);
517 error = cpuset_which(CPU_WHICH_TID, id, &p, &td, NULL);
520 CPU_COPY(&td->td_cpuset->cs_mask, mask);
530 intr_event_destroy(struct intr_event *ie)
536 mtx_lock(&event_lock);
537 mtx_lock(&ie->ie_lock);
538 if (!CK_SLIST_EMPTY(&ie->ie_handlers)) {
539 mtx_unlock(&ie->ie_lock);
540 mtx_unlock(&event_lock);
543 TAILQ_REMOVE(&event_list, ie, ie_list);
545 if (ie->ie_thread != NULL) {
546 ithread_destroy(ie->ie_thread);
547 ie->ie_thread = NULL;
550 mtx_unlock(&ie->ie_lock);
551 mtx_unlock(&event_lock);
552 mtx_destroy(&ie->ie_lock);
557 static struct intr_thread *
558 ithread_create(const char *name)
560 struct intr_thread *ithd;
564 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
566 error = kproc_kthread_add(ithread_loop, ithd, &intrproc,
567 &td, RFSTOPPED | RFHIGHPID,
568 0, "intr", "%s", name);
570 panic("kproc_create() failed with %d", error);
572 sched_class(td, PRI_ITHD);
575 td->td_pflags |= TDP_ITHREAD;
576 ithd->it_thread = td;
577 CTR2(KTR_INTR, "%s: created %s", __func__, name);
582 ithread_destroy(struct intr_thread *ithread)
586 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name);
587 td = ithread->it_thread;
589 ithread->it_flags |= IT_DEAD;
590 if (TD_AWAITING_INTR(td)) {
592 sched_wakeup(td, SRQ_INTR);
598 intr_event_add_handler(struct intr_event *ie, const char *name,
599 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
600 enum intr_type flags, void **cookiep)
602 struct intr_handler *ih, *temp_ih;
603 struct intr_handler **prevptr;
604 struct intr_thread *it;
606 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
609 /* Allocate and populate an interrupt handler structure. */
610 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
611 ih->ih_filter = filter;
612 ih->ih_handler = handler;
613 ih->ih_argument = arg;
614 strlcpy(ih->ih_name, name, sizeof(ih->ih_name));
617 if (flags & INTR_EXCL)
618 ih->ih_flags = IH_EXCLUSIVE;
619 if (flags & INTR_MPSAFE)
620 ih->ih_flags |= IH_MPSAFE;
621 if (flags & INTR_ENTROPY)
622 ih->ih_flags |= IH_ENTROPY;
623 if (flags & INTR_TYPE_NET)
624 ih->ih_flags |= IH_NET;
626 /* We can only have one exclusive handler in a event. */
627 mtx_lock(&ie->ie_lock);
628 if (!CK_SLIST_EMPTY(&ie->ie_handlers)) {
629 if ((flags & INTR_EXCL) ||
630 (CK_SLIST_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
631 mtx_unlock(&ie->ie_lock);
637 /* Create a thread if we need one. */
638 while (ie->ie_thread == NULL && handler != NULL) {
639 if (ie->ie_flags & IE_ADDING_THREAD)
640 msleep(ie, &ie->ie_lock, 0, "ithread", 0);
642 ie->ie_flags |= IE_ADDING_THREAD;
643 mtx_unlock(&ie->ie_lock);
644 it = ithread_create("intr: newborn");
645 mtx_lock(&ie->ie_lock);
646 ie->ie_flags &= ~IE_ADDING_THREAD;
654 /* Add the new handler to the event in priority order. */
655 CK_SLIST_FOREACH_PREVPTR(temp_ih, prevptr, &ie->ie_handlers, ih_next) {
656 if (temp_ih->ih_pri > ih->ih_pri)
659 CK_SLIST_INSERT_PREVPTR(prevptr, temp_ih, ih, ih_next);
661 intr_event_update(ie);
663 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
665 mtx_unlock(&ie->ie_lock);
673 * Append a description preceded by a ':' to the name of the specified
677 intr_event_describe_handler(struct intr_event *ie, void *cookie,
680 struct intr_handler *ih;
684 mtx_lock(&ie->ie_lock);
686 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) {
691 mtx_unlock(&ie->ie_lock);
692 panic("handler %p not found in interrupt event %p", cookie, ie);
698 * Look for an existing description by checking for an
699 * existing ":". This assumes device names do not include
700 * colons. If one is found, prepare to insert the new
701 * description at that point. If one is not found, find the
702 * end of the name to use as the insertion point.
704 start = strchr(ih->ih_name, ':');
706 start = strchr(ih->ih_name, 0);
709 * See if there is enough remaining room in the string for the
710 * description + ":". The "- 1" leaves room for the trailing
711 * '\0'. The "+ 1" accounts for the colon.
713 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1;
714 if (strlen(descr) + 1 > space) {
715 mtx_unlock(&ie->ie_lock);
719 /* Append a colon followed by the description. */
721 strcpy(start + 1, descr);
722 intr_event_update(ie);
723 mtx_unlock(&ie->ie_lock);
728 * Return the ie_source field from the intr_event an intr_handler is
732 intr_handler_source(void *cookie)
734 struct intr_handler *ih;
735 struct intr_event *ie;
737 ih = (struct intr_handler *)cookie;
742 ("interrupt handler \"%s\" has a NULL interrupt event",
744 return (ie->ie_source);
748 * If intr_event_handle() is running in the ISR context at the time of the call,
749 * then wait for it to complete.
752 intr_event_barrier(struct intr_event *ie)
756 mtx_assert(&ie->ie_lock, MA_OWNED);
757 phase = ie->ie_phase;
760 * Switch phase to direct future interrupts to the other active counter.
761 * Make sure that any preceding stores are visible before the switch.
763 KASSERT(ie->ie_active[!phase] == 0, ("idle phase has activity"));
764 atomic_store_rel_int(&ie->ie_phase, !phase);
767 * This code cooperates with wait-free iteration of ie_handlers
768 * in intr_event_handle.
769 * Make sure that the removal and the phase update are not reordered
770 * with the active count check.
771 * Note that no combination of acquire and release fences can provide
772 * that guarantee as Store->Load sequences can always be reordered.
774 atomic_thread_fence_seq_cst();
777 * Now wait on the inactive phase.
778 * The acquire fence is needed so that all post-barrier accesses
779 * are after the check.
781 while (ie->ie_active[phase] > 0)
783 atomic_thread_fence_acq();
787 intr_handler_barrier(struct intr_handler *handler)
789 struct intr_event *ie;
791 ie = handler->ih_event;
792 mtx_assert(&ie->ie_lock, MA_OWNED);
793 KASSERT((handler->ih_flags & IH_DEAD) == 0,
794 ("update for a removed handler"));
796 if (ie->ie_thread == NULL) {
797 intr_event_barrier(ie);
800 if ((handler->ih_flags & IH_CHANGED) == 0) {
801 handler->ih_flags |= IH_CHANGED;
802 intr_event_schedule_thread(ie, NULL);
804 while ((handler->ih_flags & IH_CHANGED) != 0)
805 msleep(handler, &ie->ie_lock, 0, "ih_barr", 0);
809 * Sleep until an ithread finishes executing an interrupt handler.
811 * XXX Doesn't currently handle interrupt filters or fast interrupt
812 * handlers. This is intended for LinuxKPI drivers only.
813 * Do not use in BSD code.
818 struct intr_event *ie;
819 struct intr_thread *ithd;
822 ie = intr_lookup(irq);
825 if (ie->ie_thread == NULL)
827 ithd = ie->ie_thread;
828 td = ithd->it_thread;
830 * We set the flag and wait for it to be cleared to avoid
831 * long delays with potentially busy interrupt handlers
832 * were we to only sample TD_AWAITING_INTR() every tick.
835 if (!TD_AWAITING_INTR(td)) {
836 ithd->it_flags |= IT_WAIT;
837 while (ithd->it_flags & IT_WAIT) {
848 intr_event_remove_handler(void *cookie)
850 struct intr_handler *handler = (struct intr_handler *)cookie;
851 struct intr_event *ie;
852 struct intr_handler *ih;
853 struct intr_handler **prevptr;
860 ie = handler->ih_event;
862 ("interrupt handler \"%s\" has a NULL interrupt event",
865 mtx_lock(&ie->ie_lock);
866 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
868 CK_SLIST_FOREACH_PREVPTR(ih, prevptr, &ie->ie_handlers, ih_next) {
873 panic("interrupt handler \"%s\" not found in "
874 "interrupt event \"%s\"", handler->ih_name, ie->ie_name);
878 * If there is no ithread, then directly remove the handler. Note that
879 * intr_event_handle() iterates ie_handlers in a lock-less fashion, so
880 * care needs to be taken to keep ie_handlers consistent and to free
881 * the removed handler only when ie_handlers is quiescent.
883 if (ie->ie_thread == NULL) {
884 CK_SLIST_REMOVE_PREVPTR(prevptr, ih, ih_next);
885 intr_event_barrier(ie);
886 intr_event_update(ie);
887 mtx_unlock(&ie->ie_lock);
888 free(handler, M_ITHREAD);
893 * Let the interrupt thread do the job.
894 * The interrupt source is disabled when the interrupt thread is
895 * running, so it does not have to worry about interaction with
896 * intr_event_handle().
898 KASSERT((handler->ih_flags & IH_DEAD) == 0,
899 ("duplicate handle remove"));
900 handler->ih_flags |= IH_DEAD;
901 intr_event_schedule_thread(ie, NULL);
902 while (handler->ih_flags & IH_DEAD)
903 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
904 intr_event_update(ie);
908 * XXX: This could be bad in the case of ppbus(8). Also, I think
909 * this could lead to races of stale data when servicing an
913 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) {
914 if (ih->ih_handler != NULL) {
920 ithread_destroy(ie->ie_thread);
921 ie->ie_thread = NULL;
924 mtx_unlock(&ie->ie_lock);
925 free(handler, M_ITHREAD);
930 intr_event_suspend_handler(void *cookie)
932 struct intr_handler *handler = (struct intr_handler *)cookie;
933 struct intr_event *ie;
937 ie = handler->ih_event;
939 ("interrupt handler \"%s\" has a NULL interrupt event",
941 mtx_lock(&ie->ie_lock);
942 handler->ih_flags |= IH_SUSP;
943 intr_handler_barrier(handler);
944 mtx_unlock(&ie->ie_lock);
949 intr_event_resume_handler(void *cookie)
951 struct intr_handler *handler = (struct intr_handler *)cookie;
952 struct intr_event *ie;
956 ie = handler->ih_event;
958 ("interrupt handler \"%s\" has a NULL interrupt event",
962 * intr_handler_barrier() acts not only as a barrier,
963 * it also allows to check for any pending interrupts.
965 mtx_lock(&ie->ie_lock);
966 handler->ih_flags &= ~IH_SUSP;
967 intr_handler_barrier(handler);
968 mtx_unlock(&ie->ie_lock);
973 intr_event_schedule_thread(struct intr_event *ie, struct trapframe *frame)
975 struct intr_entropy entropy;
976 struct intr_thread *it;
981 * If no ithread or no handlers, then we have a stray interrupt.
983 if (ie == NULL || CK_SLIST_EMPTY(&ie->ie_handlers) ||
984 ie->ie_thread == NULL)
992 * If any of the handlers for this ithread claim to be good
993 * sources of entropy, then gather some.
995 if (ie->ie_hflags & IH_ENTROPY) {
996 entropy.event = (uintptr_t)ie;
998 random_harvest_queue(&entropy, sizeof(entropy), RANDOM_INTERRUPT);
1001 KASSERT(td->td_proc != NULL, ("ithread %s has no process", ie->ie_name));
1004 * Set it_need to tell the thread to keep running if it is already
1005 * running. Then, lock the thread and see if we actually need to
1006 * put it on the runqueue.
1008 * Use store_rel to arrange that the store to ih_need in
1009 * swi_sched() is before the store to it_need and prepare for
1010 * transfer of this order to loads in the ithread.
1012 atomic_store_rel_int(&it->it_need, 1);
1014 if (TD_AWAITING_INTR(td)) {
1017 if (PMC_HOOK_INSTALLED_ANY())
1018 PMC_SOFT_CALL_INTR_HLPR(schedule, frame);
1020 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, td->td_proc->p_pid,
1023 sched_wakeup(td, SRQ_INTR);
1027 if (PMC_HOOK_INSTALLED_ANY() &&
1028 (it->it_waiting >= intr_hwpmc_waiting_report_threshold))
1029 PMC_SOFT_CALL_INTR_HLPR(waiting, frame);
1031 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
1032 __func__, td->td_proc->p_pid, td->td_name, it->it_need, TD_GET_STATE(td));
1040 * Allow interrupt event binding for software interrupt handlers -- a no-op,
1041 * since interrupts are generated in software rather than being directed by
1045 swi_assign_cpu(void *arg, int cpu)
1052 * Add a software interrupt handler to a specified event. If a given event
1053 * is not specified, then a new event is created.
1056 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler,
1057 void *arg, int pri, enum intr_type flags, void **cookiep)
1059 struct intr_event *ie;
1062 if (flags & INTR_ENTROPY)
1065 ie = (eventp != NULL) ? *eventp : NULL;
1068 if (!(ie->ie_flags & IE_SOFT))
1071 error = intr_event_create(&ie, NULL, IE_SOFT, 0,
1072 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri);
1078 if (handler != NULL) {
1079 error = intr_event_add_handler(ie, name, NULL, handler, arg,
1080 PI_SWI(pri), flags, cookiep);
1086 * Schedule a software interrupt thread.
1089 swi_sched(void *cookie, int flags)
1091 struct intr_handler *ih = (struct intr_handler *)cookie;
1092 struct intr_event *ie = ih->ih_event;
1093 struct intr_entropy entropy;
1096 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name,
1099 if ((flags & SWI_FROMNMI) == 0) {
1100 entropy.event = (uintptr_t)ih;
1101 entropy.td = curthread;
1102 random_harvest_queue(&entropy, sizeof(entropy), RANDOM_SWI);
1106 * Set ih_need for this handler so that if the ithread is already
1107 * running it will execute this handler on the next pass. Otherwise,
1108 * it will execute it the next time it runs.
1112 if (flags & SWI_DELAY)
1115 if (flags & SWI_FROMNMI) {
1116 #if defined(SMP) && (defined(__i386__) || defined(__amd64__))
1117 KASSERT(ie == clk_intr_event,
1118 ("SWI_FROMNMI used not with clk_intr_event"));
1119 ipi_self_from_nmi(IPI_SWI);
1123 error = intr_event_schedule_thread(ie, NULL);
1124 KASSERT(error == 0, ("stray software interrupt"));
1129 * Remove a software interrupt handler. Currently this code does not
1130 * remove the associated interrupt event if it becomes empty. Calling code
1131 * may do so manually via intr_event_destroy(), but that's not really
1132 * an optimal interface.
1135 swi_remove(void *cookie)
1138 return (intr_event_remove_handler(cookie));
1142 intr_event_execute_handlers(struct proc *p, struct intr_event *ie)
1144 struct intr_handler *ih, *ihn, *ihp;
1147 CK_SLIST_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) {
1149 * If this handler is marked for death, remove it from
1150 * the list of handlers and wake up the sleeper.
1152 if (ih->ih_flags & IH_DEAD) {
1153 mtx_lock(&ie->ie_lock);
1155 CK_SLIST_REMOVE_HEAD(&ie->ie_handlers, ih_next);
1157 CK_SLIST_REMOVE_AFTER(ihp, ih_next);
1158 ih->ih_flags &= ~IH_DEAD;
1160 mtx_unlock(&ie->ie_lock);
1165 * Now that we know that the current element won't be removed
1166 * update the previous element.
1170 if ((ih->ih_flags & IH_CHANGED) != 0) {
1171 mtx_lock(&ie->ie_lock);
1172 ih->ih_flags &= ~IH_CHANGED;
1174 mtx_unlock(&ie->ie_lock);
1177 /* Skip filter only handlers */
1178 if (ih->ih_handler == NULL)
1181 /* Skip suspended handlers */
1182 if ((ih->ih_flags & IH_SUSP) != 0)
1186 * For software interrupt threads, we only execute
1187 * handlers that have their need flag set. Hardware
1188 * interrupt threads always invoke all of their handlers.
1190 * ih_need can only be 0 or 1. Failed cmpset below
1191 * means that there is no request to execute handlers,
1192 * so a retry of the cmpset is not needed.
1194 if ((ie->ie_flags & IE_SOFT) != 0 &&
1195 atomic_cmpset_int(&ih->ih_need, 1, 0) == 0)
1198 /* Execute this handler. */
1199 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1200 __func__, p->p_pid, (void *)ih->ih_handler,
1201 ih->ih_argument, ih->ih_name, ih->ih_flags);
1203 if (!(ih->ih_flags & IH_MPSAFE))
1205 ih->ih_handler(ih->ih_argument);
1206 if (!(ih->ih_flags & IH_MPSAFE))
1212 ithread_execute_handlers(struct proc *p, struct intr_event *ie)
1215 /* Interrupt handlers should not sleep. */
1216 if (!(ie->ie_flags & IE_SOFT))
1217 THREAD_NO_SLEEPING();
1218 intr_event_execute_handlers(p, ie);
1219 if (!(ie->ie_flags & IE_SOFT))
1220 THREAD_SLEEPING_OK();
1223 * Interrupt storm handling:
1225 * If this interrupt source is currently storming, then throttle
1226 * it to only fire the handler once per clock tick.
1228 * If this interrupt source is not currently storming, but the
1229 * number of back to back interrupts exceeds the storm threshold,
1230 * then enter storming mode.
1232 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold &&
1233 !(ie->ie_flags & IE_SOFT)) {
1234 /* Report the message only once every second. */
1235 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) {
1237 "interrupt storm detected on \"%s\"; throttling interrupt source\n",
1245 * Now that all the handlers have had a chance to run, reenable
1246 * the interrupt source.
1248 if (ie->ie_post_ithread != NULL)
1249 ie->ie_post_ithread(ie->ie_source);
1253 * This is the main code for interrupt threads.
1256 ithread_loop(void *arg)
1258 struct epoch_tracker et;
1259 struct intr_thread *ithd;
1260 struct intr_event *ie;
1263 int wake, epoch_count;
1268 ithd = (struct intr_thread *)arg;
1269 KASSERT(ithd->it_thread == td,
1270 ("%s: ithread and proc linkage out of sync", __func__));
1271 ie = ithd->it_event;
1276 * As long as we have interrupts outstanding, go through the
1277 * list of handlers, giving each one a go at it.
1281 * If we are an orphaned thread, then just die.
1283 if (ithd->it_flags & IT_DEAD) {
1284 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1285 p->p_pid, td->td_name);
1286 free(ithd, M_ITHREAD);
1291 * Service interrupts. If another interrupt arrives while
1292 * we are running, it will set it_need to note that we
1293 * should make another pass.
1295 * The load_acq part of the following cmpset ensures
1296 * that the load of ih_need in ithread_execute_handlers()
1297 * is ordered after the load of it_need here.
1300 (atomic_load_int(&ie->ie_hflags) & IH_NET) != 0;
1303 NET_EPOCH_ENTER(et);
1305 while (atomic_cmpset_acq_int(&ithd->it_need, 1, 0) != 0) {
1306 ithread_execute_handlers(p, ie);
1308 ++epoch_count >= intr_epoch_batch) {
1311 NET_EPOCH_ENTER(et);
1316 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1317 mtx_assert(&Giant, MA_NOTOWNED);
1320 * Processed all our interrupts. Now get the sched
1321 * lock. This may take a while and it_need may get
1322 * set again, so we have to check it again.
1325 if (atomic_load_acq_int(&ithd->it_need) == 0 &&
1326 (ithd->it_flags & (IT_DEAD | IT_WAIT)) == 0) {
1329 mi_switch(SW_VOL | SWT_IWAIT);
1331 if (ithd->it_flags & IT_WAIT) {
1333 ithd->it_flags &= ~IT_WAIT;
1345 * Main interrupt handling body.
1348 * o ie: the event connected to this interrupt.
1349 * o frame: some archs (i.e. i386) pass a frame to some.
1350 * handlers as their main argument.
1352 * o 0: everything ok.
1353 * o EINVAL: stray interrupt.
1356 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1358 struct intr_handler *ih;
1359 struct trapframe *oldframe;
1363 bool filter, thread;
1367 #ifdef KSTACK_USAGE_PROF
1368 intr_prof_stack_use(td, frame);
1371 /* An interrupt with no event or handlers is a stray interrupt. */
1372 if (ie == NULL || CK_SLIST_EMPTY(&ie->ie_handlers))
1376 * Execute fast interrupt handlers directly.
1377 * To support clock handlers, if a handler registers
1378 * with a NULL argument, then we pass it a pointer to
1379 * a trapframe as its argument.
1381 td->td_intr_nesting_level++;
1386 oldframe = td->td_intr_frame;
1387 td->td_intr_frame = frame;
1389 phase = ie->ie_phase;
1390 atomic_add_int(&ie->ie_active[phase], 1);
1393 * This fence is required to ensure that no later loads are
1394 * re-ordered before the ie_active store.
1396 atomic_thread_fence_seq_cst();
1398 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) {
1399 if ((ih->ih_flags & IH_SUSP) != 0)
1401 if ((ie->ie_flags & IE_SOFT) != 0 && ih->ih_need == 0)
1403 if (ih->ih_filter == NULL) {
1407 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__,
1408 ih->ih_filter, ih->ih_argument == NULL ? frame :
1409 ih->ih_argument, ih->ih_name);
1410 if (ih->ih_argument == NULL)
1411 ret = ih->ih_filter(frame);
1413 ret = ih->ih_filter(ih->ih_argument);
1415 PMC_SOFT_CALL_TF( , , intr, all, frame);
1417 KASSERT(ret == FILTER_STRAY ||
1418 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 &&
1419 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0),
1420 ("%s: incorrect return value %#x from %s", __func__, ret,
1422 filter = filter || ret == FILTER_HANDLED;
1424 if (ret & FILTER_SCHEDULE_THREAD)
1425 PMC_SOFT_CALL_TF( , , intr, ithread, frame);
1426 else if (ret & FILTER_HANDLED)
1427 PMC_SOFT_CALL_TF( , , intr, filter, frame);
1428 else if (ret == FILTER_STRAY)
1429 PMC_SOFT_CALL_TF( , , intr, stray, frame);
1433 * Wrapper handler special handling:
1435 * in some particular cases (like pccard and pccbb),
1436 * the _real_ device handler is wrapped in a couple of
1437 * functions - a filter wrapper and an ithread wrapper.
1438 * In this case (and just in this case), the filter wrapper
1439 * could ask the system to schedule the ithread and mask
1440 * the interrupt source if the wrapped handler is composed
1441 * of just an ithread handler.
1443 * TODO: write a generic wrapper to avoid people rolling
1447 if (ret == FILTER_SCHEDULE_THREAD)
1451 atomic_add_rel_int(&ie->ie_active[phase], -1);
1453 td->td_intr_frame = oldframe;
1456 if (ie->ie_pre_ithread != NULL)
1457 ie->ie_pre_ithread(ie->ie_source);
1459 if (ie->ie_post_filter != NULL)
1460 ie->ie_post_filter(ie->ie_source);
1463 /* Schedule the ithread if needed. */
1467 error = intr_event_schedule_thread(ie, frame);
1468 KASSERT(error == 0, ("bad stray interrupt"));
1471 td->td_intr_nesting_level--;
1473 /* The interrupt is not aknowledged by any filter and has no ithread. */
1474 if (!thread && !filter)
1482 * Dump details about an interrupt handler
1485 db_dump_intrhand(struct intr_handler *ih)
1489 db_printf("\t%-10s ", ih->ih_name);
1490 switch (ih->ih_pri) {
1498 if (ih->ih_pri >= PI_SOFT)
1501 db_printf("%4u", ih->ih_pri);
1505 if (ih->ih_filter != NULL) {
1507 db_printsym((uintptr_t)ih->ih_filter, DB_STGY_PROC);
1509 if (ih->ih_handler != NULL) {
1510 if (ih->ih_filter != NULL)
1513 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC);
1515 db_printf("(%p)", ih->ih_argument);
1517 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD |
1521 if (ih->ih_flags & IH_EXCLUSIVE) {
1527 if (ih->ih_flags & IH_ENTROPY) {
1530 db_printf("ENTROPY");
1533 if (ih->ih_flags & IH_DEAD) {
1539 if (ih->ih_flags & IH_MPSAFE) {
1542 db_printf("MPSAFE");
1556 * Dump details about a event.
1559 db_dump_intr_event(struct intr_event *ie, int handlers)
1561 struct intr_handler *ih;
1562 struct intr_thread *it;
1565 db_printf("%s ", ie->ie_fullname);
1568 db_printf("(pid %d)", it->it_thread->td_proc->p_pid);
1570 db_printf("(no thread)");
1571 if ((ie->ie_flags & (IE_SOFT | IE_ADDING_THREAD)) != 0 ||
1572 (it != NULL && it->it_need)) {
1575 if (ie->ie_flags & IE_SOFT) {
1579 if (ie->ie_flags & IE_ADDING_THREAD) {
1582 db_printf("ADDING_THREAD");
1585 if (it != NULL && it->it_need) {
1595 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next)
1596 db_dump_intrhand(ih);
1600 * Dump data about interrupt handlers
1602 DB_SHOW_COMMAND_FLAGS(intr, db_show_intr, DB_CMD_MEMSAFE)
1604 struct intr_event *ie;
1607 verbose = strchr(modif, 'v') != NULL;
1608 all = strchr(modif, 'a') != NULL;
1609 TAILQ_FOREACH(ie, &event_list, ie_list) {
1610 if (!all && CK_SLIST_EMPTY(&ie->ie_handlers))
1612 db_dump_intr_event(ie, verbose);
1620 * Start standard software interrupt threads
1623 start_softintr(void *dummy)
1626 if (swi_add(&clk_intr_event, "clk", NULL, NULL, SWI_CLOCK,
1628 panic("died while creating clk swi ithread");
1630 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr,
1634 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
1635 * The data for this machine dependent, and the declarations are in machine
1636 * dependent code. The layout of intrnames and intrcnt however is machine
1639 * We do not know the length of intrcnt and intrnames at compile time, so
1640 * calculate things at run time.
1643 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
1645 return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req));
1648 SYSCTL_PROC(_hw, OID_AUTO, intrnames,
1649 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
1650 sysctl_intrnames, "",
1654 sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
1657 uint32_t *intrcnt32;
1661 if (req->flags & SCTL_MASK32) {
1663 return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req));
1664 intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT);
1665 if (intrcnt32 == NULL)
1667 for (i = 0; i < sintrcnt / sizeof (u_long); i++)
1668 intrcnt32[i] = intrcnt[i];
1669 error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req);
1670 free(intrcnt32, M_TEMP);
1674 return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req));
1677 SYSCTL_PROC(_hw, OID_AUTO, intrcnt,
1678 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
1680 "Interrupt Counts");
1684 * DDB command to dump the interrupt statistics.
1686 DB_SHOW_COMMAND_FLAGS(intrcnt, db_show_intrcnt, DB_CMD_MEMSAFE)
1694 for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit;
1699 db_printf("%s\t%lu\n", cp, *i);
1700 cp += strlen(cp) + 1;