2 * Copyright (c) 2003 Matthew Dillon <dillon@backplane.com> All rights reserved.
3 * Copyright (c) 1997, Stefan Esser <se@freebsd.org> All rights reserved.
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.
26 * $FreeBSD: src/sys/kern/kern_intr.c,v 1.24.2.1 2001/10/14 20:05:50 luigi Exp $
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/malloc.h>
33 #include <sys/kernel.h>
34 #include <sys/sysctl.h>
35 #include <sys/thread.h>
37 #include <sys/random.h>
38 #include <sys/serialize.h>
39 #include <sys/interrupt.h>
41 #include <sys/machintr.h>
43 #include <machine/frame.h>
45 #include <sys/thread2.h>
46 #include <sys/mplock2.h>
50 typedef struct intrec {
52 struct intr_info *info;
58 struct lwkt_serialize *serializer;
63 struct thread i_thread;
64 struct random_softc i_random;
66 long i_count; /* interrupts dispatched */
67 int i_mplock_required;
72 unsigned long i_straycount;
77 static struct intr_info intr_info_ary[MAXCPU][MAX_INTS];
78 static struct intr_info *swi_info_ary[MAX_SOFTINTS];
80 static int max_installed_hard_intr[MAXCPU];
82 #define EMERGENCY_INTR_POLLING_FREQ_MAX 20000
85 * Assert that callers into interrupt handlers don't return with
86 * dangling tokens, spinlocks, or mp locks.
90 #define TD_INVARIANTS_DECLARE \
94 #define TD_INVARIANTS_GET(td) \
96 spincount = (td)->td_gd->gd_spinlocks_wr; \
97 curstop = (td)->td_toks_stop; \
100 #define TD_INVARIANTS_TEST(td, name) \
102 KASSERT(spincount == (td)->td_gd->gd_spinlocks_wr, \
103 ("spincount mismatch after interrupt handler %s", \
105 KASSERT(curstop == (td)->td_toks_stop, \
106 ("token count mismatch after interrupt handler %s", \
114 #define TD_INVARIANTS_DECLARE
115 #define TD_INVARIANTS_GET(td)
116 #define TD_INVARIANTS_TEST(td, name)
118 #endif /* ndef INVARIANTS */
120 static int sysctl_emergency_freq(SYSCTL_HANDLER_ARGS);
121 static int sysctl_emergency_enable(SYSCTL_HANDLER_ARGS);
122 static void emergency_intr_timer_callback(systimer_t, int, struct intrframe *);
123 static void ithread_handler(void *arg);
124 static void ithread_emergency(void *arg);
125 static void report_stray_interrupt(struct intr_info *info, const char *func);
126 static void int_moveto_destcpu(int *, int);
127 static void int_moveto_origcpu(int, int);
128 static void sched_ithd_intern(struct intr_info *info);
130 static struct systimer emergency_intr_timer[MAXCPU];
131 static struct thread emergency_intr_thread[MAXCPU];
133 #define ISTATE_NOTHREAD 0
134 #define ISTATE_NORMAL 1
135 #define ISTATE_LIVELOCKED 2
137 static int livelock_limit = 40000;
138 static int livelock_lowater = 20000;
139 static int livelock_debug = -1;
140 SYSCTL_INT(_kern, OID_AUTO, livelock_limit,
141 CTLFLAG_RW, &livelock_limit, 0, "Livelock interrupt rate limit");
142 SYSCTL_INT(_kern, OID_AUTO, livelock_lowater,
143 CTLFLAG_RW, &livelock_lowater, 0, "Livelock low-water mark restore");
144 SYSCTL_INT(_kern, OID_AUTO, livelock_debug,
145 CTLFLAG_RW, &livelock_debug, 0, "Livelock debug intr#");
147 static int emergency_intr_enable = 0; /* emergency interrupt polling */
148 TUNABLE_INT("kern.emergency_intr_enable", &emergency_intr_enable);
149 SYSCTL_PROC(_kern, OID_AUTO, emergency_intr_enable, CTLTYPE_INT | CTLFLAG_RW,
150 0, 0, sysctl_emergency_enable, "I", "Emergency Interrupt Poll Enable");
152 static int emergency_intr_freq = 10; /* emergency polling frequency */
153 TUNABLE_INT("kern.emergency_intr_freq", &emergency_intr_freq);
154 SYSCTL_PROC(_kern, OID_AUTO, emergency_intr_freq, CTLTYPE_INT | CTLFLAG_RW,
155 0, 0, sysctl_emergency_freq, "I", "Emergency Interrupt Poll Frequency");
158 * Sysctl support routines
161 sysctl_emergency_enable(SYSCTL_HANDLER_ARGS)
163 int error, enabled, cpuid, freq;
165 enabled = emergency_intr_enable;
166 error = sysctl_handle_int(oidp, &enabled, 0, req);
167 if (error || req->newptr == NULL)
169 emergency_intr_enable = enabled;
170 if (emergency_intr_enable)
171 freq = emergency_intr_freq;
175 for (cpuid = 0; cpuid < ncpus; ++cpuid)
176 systimer_adjust_periodic(&emergency_intr_timer[cpuid], freq);
181 sysctl_emergency_freq(SYSCTL_HANDLER_ARGS)
183 int error, phz, cpuid, freq;
185 phz = emergency_intr_freq;
186 error = sysctl_handle_int(oidp, &phz, 0, req);
187 if (error || req->newptr == NULL)
191 else if (phz > EMERGENCY_INTR_POLLING_FREQ_MAX)
192 phz = EMERGENCY_INTR_POLLING_FREQ_MAX;
194 emergency_intr_freq = phz;
195 if (emergency_intr_enable)
196 freq = emergency_intr_freq;
200 for (cpuid = 0; cpuid < ncpus; ++cpuid)
201 systimer_adjust_periodic(&emergency_intr_timer[cpuid], freq);
206 * Register an SWI or INTerrupt handler.
209 register_swi(int intr, inthand2_t *handler, void *arg, const char *name,
210 struct lwkt_serialize *serializer, int cpuid)
212 if (intr < FIRST_SOFTINT || intr >= MAX_INTS)
213 panic("register_swi: bad intr %d", intr);
216 cpuid = intr % ncpus;
217 return(register_int(intr, handler, arg, name, serializer, 0, cpuid));
221 register_swi_mp(int intr, inthand2_t *handler, void *arg, const char *name,
222 struct lwkt_serialize *serializer, int cpuid)
224 if (intr < FIRST_SOFTINT || intr >= MAX_INTS)
225 panic("register_swi: bad intr %d", intr);
228 cpuid = intr % ncpus;
229 return(register_int(intr, handler, arg, name, serializer,
230 INTR_MPSAFE, cpuid));
234 register_int(int intr, inthand2_t *handler, void *arg, const char *name,
235 struct lwkt_serialize *serializer, int intr_flags, int cpuid)
237 struct intr_info *info;
238 struct intrec **list;
242 KKASSERT(cpuid >= 0 && cpuid < ncpus);
244 if (intr < 0 || intr >= MAX_INTS)
245 panic("register_int: bad intr %d", intr);
248 info = &intr_info_ary[cpuid][intr];
251 * Construct an interrupt handler record
253 rec = kmalloc(sizeof(struct intrec), M_DEVBUF, M_INTWAIT);
254 rec->name = kmalloc(strlen(name) + 1, M_DEVBUF, M_INTWAIT);
255 strcpy(rec->name, name);
258 rec->handler = handler;
261 rec->intr_flags = intr_flags;
263 rec->serializer = serializer;
265 int_moveto_destcpu(&orig_cpuid, cpuid);
268 * Create an emergency polling thread and set up a systimer to wake
271 if (emergency_intr_thread[cpuid].td_kstack == NULL) {
272 lwkt_create(ithread_emergency, NULL, NULL,
273 &emergency_intr_thread[cpuid],
274 TDF_NOSTART | TDF_INTTHREAD, cpuid, "ithreadE %d",
276 systimer_init_periodic_nq(&emergency_intr_timer[cpuid],
277 emergency_intr_timer_callback,
278 &emergency_intr_thread[cpuid],
279 (emergency_intr_enable ? emergency_intr_freq : 1));
283 * Create an interrupt thread if necessary, leave it in an unscheduled
286 if (info->i_state == ISTATE_NOTHREAD) {
287 info->i_state = ISTATE_NORMAL;
288 lwkt_create(ithread_handler, (void *)(intptr_t)intr, NULL,
289 &info->i_thread, TDF_NOSTART | TDF_INTTHREAD, cpuid,
290 "ithread%d %d", intr, cpuid);
291 if (intr >= FIRST_SOFTINT)
292 lwkt_setpri(&info->i_thread, TDPRI_SOFT_NORM);
294 lwkt_setpri(&info->i_thread, TDPRI_INT_MED);
295 info->i_thread.td_preemptable = lwkt_preempt;
298 list = &info->i_reclist;
301 * Keep track of how many fast and slow interrupts we have.
302 * Set i_mplock_required if any handler in the chain requires
303 * the MP lock to operate.
305 if ((intr_flags & INTR_MPSAFE) == 0)
306 info->i_mplock_required = 1;
307 if (intr_flags & INTR_CLOCK)
313 * Enable random number generation keying off of this interrupt.
315 if ((intr_flags & INTR_NOENTROPY) == 0 && info->i_random.sc_enabled == 0) {
316 info->i_random.sc_enabled = 1;
317 info->i_random.sc_intr = intr;
321 * Add the record to the interrupt list.
324 while (*list != NULL)
325 list = &(*list)->next;
330 * Update max_installed_hard_intr to make the emergency intr poll
331 * a bit more efficient.
333 if (intr < FIRST_SOFTINT) {
334 if (max_installed_hard_intr[cpuid] <= intr)
335 max_installed_hard_intr[cpuid] = intr + 1;
338 if (intr >= FIRST_SOFTINT)
339 swi_info_ary[intr - FIRST_SOFTINT] = info;
342 * Setup the machine level interrupt vector
344 if (intr < FIRST_SOFTINT && info->i_slow + info->i_fast == 1)
345 machintr_intr_setup(intr, intr_flags);
347 int_moveto_origcpu(orig_cpuid, cpuid);
353 unregister_swi(void *id, int intr, int cpuid)
356 cpuid = intr % ncpus;
358 unregister_int(id, cpuid);
362 unregister_int(void *id, int cpuid)
364 struct intr_info *info;
365 struct intrec **list;
367 int intr, orig_cpuid;
369 KKASSERT(cpuid >= 0 && cpuid < ncpus);
371 intr = ((intrec_t)id)->intr;
373 if (intr < 0 || intr >= MAX_INTS)
374 panic("register_int: bad intr %d", intr);
376 info = &intr_info_ary[cpuid][intr];
378 int_moveto_destcpu(&orig_cpuid, cpuid);
381 * Remove the interrupt descriptor, adjust the descriptor count,
382 * and teardown the machine level vector if this was the last interrupt.
385 list = &info->i_reclist;
386 while ((rec = *list) != NULL) {
395 if (rec->intr_flags & INTR_CLOCK)
399 if (intr < FIRST_SOFTINT && info->i_fast + info->i_slow == 0)
400 machintr_intr_teardown(intr);
403 * Clear i_mplock_required if no handlers in the chain require the
406 for (rec0 = info->i_reclist; rec0; rec0 = rec0->next) {
407 if ((rec0->intr_flags & INTR_MPSAFE) == 0)
411 info->i_mplock_required = 0;
414 if (intr >= FIRST_SOFTINT && info->i_reclist == NULL)
415 swi_info_ary[intr - FIRST_SOFTINT] = NULL;
419 int_moveto_origcpu(orig_cpuid, cpuid);
425 kfree(rec->name, M_DEVBUF);
426 kfree(rec, M_DEVBUF);
428 kprintf("warning: unregister_int: int %d handler for %s not found\n",
429 intr, ((intrec_t)id)->name);
434 get_interrupt_counter(int intr, int cpuid)
436 struct intr_info *info;
438 KKASSERT(cpuid >= 0 && cpuid < ncpus);
440 if (intr < 0 || intr >= MAX_INTS)
441 panic("register_int: bad intr %d", intr);
442 info = &intr_info_ary[cpuid][intr];
443 return(info->i_count);
447 register_randintr(int intr)
449 struct intr_info *info;
452 if (intr < 0 || intr >= MAX_INTS)
453 panic("register_randintr: bad intr %d", intr);
455 for (cpuid = 0; cpuid < ncpus; ++cpuid) {
456 info = &intr_info_ary[cpuid][intr];
457 info->i_random.sc_intr = intr;
458 info->i_random.sc_enabled = 1;
463 unregister_randintr(int intr)
465 struct intr_info *info;
468 if (intr < 0 || intr >= MAX_INTS)
469 panic("register_swi: bad intr %d", intr);
471 for (cpuid = 0; cpuid < ncpus; ++cpuid) {
472 info = &intr_info_ary[cpuid][intr];
473 info->i_random.sc_enabled = -1;
478 next_registered_randintr(int intr)
480 struct intr_info *info;
482 if (intr < 0 || intr >= MAX_INTS)
483 panic("register_swi: bad intr %d", intr);
485 while (intr < MAX_INTS) {
488 for (cpuid = 0; cpuid < ncpus; ++cpuid) {
489 info = &intr_info_ary[cpuid][intr];
490 if (info->i_random.sc_enabled > 0)
499 * Dispatch an interrupt. If there's nothing to do we have a stray
500 * interrupt and can just return, leaving the interrupt masked.
502 * We need to schedule the interrupt and set its i_running bit. If
503 * we are not on the interrupt thread's cpu we have to send a message
504 * to the correct cpu that will issue the desired action (interlocking
505 * with the interrupt thread's critical section). We do NOT attempt to
506 * reschedule interrupts whos i_running bit is already set because
507 * this would prematurely wakeup a livelock-limited interrupt thread.
509 * i_running is only tested/set on the same cpu as the interrupt thread.
511 * We are NOT in a critical section, which will allow the scheduled
512 * interrupt to preempt us. The MP lock might *NOT* be held here.
517 sched_ithd_remote(void *arg)
519 sched_ithd_intern(arg);
525 sched_ithd_intern(struct intr_info *info)
528 if (info->i_state != ISTATE_NOTHREAD) {
529 if (info->i_reclist == NULL) {
530 report_stray_interrupt(info, "sched_ithd");
533 if (info->i_thread.td_gd == mycpu) {
534 if (info->i_running == 0) {
536 if (info->i_state != ISTATE_LIVELOCKED)
537 lwkt_schedule(&info->i_thread); /* MIGHT PREEMPT */
540 lwkt_send_ipiq(info->i_thread.td_gd, sched_ithd_remote, info);
543 if (info->i_running == 0) {
545 if (info->i_state != ISTATE_LIVELOCKED)
546 lwkt_schedule(&info->i_thread); /* MIGHT PREEMPT */
551 report_stray_interrupt(info, "sched_ithd");
556 sched_ithd_soft(int intr)
558 struct intr_info *info;
560 KKASSERT(intr >= FIRST_SOFTINT && intr < MAX_INTS);
562 info = swi_info_ary[intr - FIRST_SOFTINT];
564 sched_ithd_intern(info);
566 kprintf("unregistered softint %d got scheduled on cpu%d\n",
572 sched_ithd_hard(int intr)
574 KKASSERT(intr >= 0 && intr < MAX_HARDINTS);
575 sched_ithd_intern(&intr_info_ary[mycpuid][intr]);
579 report_stray_interrupt(struct intr_info *info, const char *func)
581 ++info->i_straycount;
582 if (info->i_straycount < 10) {
583 if (info->i_errorticks == ticks)
585 info->i_errorticks = ticks;
586 kprintf("%s: stray interrupt %d on cpu%d\n",
587 func, info->i_intr, mycpuid);
588 } else if (info->i_straycount == 10) {
589 kprintf("%s: %ld stray interrupts %d on cpu%d - "
590 "there will be no further reports\n", func,
591 info->i_straycount, info->i_intr, mycpuid);
596 * This is run from a periodic SYSTIMER (and thus must be MP safe, the BGL
597 * might not be held).
600 ithread_livelock_wakeup(systimer_t st, int in_ipi __unused,
601 struct intrframe *frame __unused)
603 struct intr_info *info;
605 info = &intr_info_ary[mycpuid][(int)(intptr_t)st->data];
606 if (info->i_state != ISTATE_NOTHREAD)
607 lwkt_schedule(&info->i_thread);
611 * Schedule ithread within fast intr handler
613 * XXX Protect sched_ithd_hard() call with gd_intr_nesting_level?
614 * Interrupts aren't enabled, but still...
617 ithread_fast_sched(int intr, thread_t td)
622 * We are already in critical section, exit it now to
626 sched_ithd_hard(intr);
627 crit_enter_quick(td);
633 * This function is called directly from the ICU or APIC vector code assembly
634 * to process an interrupt. The critical section and interrupt deferral
635 * checks have already been done but the function is entered WITHOUT
636 * a critical section held. The BGL may or may not be held.
638 * Must return non-zero if we do not want the vector code to re-enable
639 * the interrupt (which we don't if we have to schedule the interrupt)
641 int ithread_fast_handler(struct intrframe *frame);
644 ithread_fast_handler(struct intrframe *frame)
647 struct intr_info *info;
648 struct intrec **list;
653 TD_INVARIANTS_DECLARE;
658 intr = frame->if_vec;
662 /* We must be in critical section. */
663 KKASSERT(td->td_critcount);
665 info = &intr_info_ary[mycpuid][intr];
668 * If we are not processing any FAST interrupts, just schedule the thing.
670 if (info->i_fast == 0) {
672 ithread_fast_sched(intr, td);
677 * This should not normally occur since interrupts ought to be
678 * masked if the ithread has been scheduled or is running.
684 * Bump the interrupt nesting level to process any FAST interrupts.
685 * Obtain the MP lock as necessary. If the MP lock cannot be obtained,
686 * schedule the interrupt thread to deal with the issue instead.
688 * To reduce overhead, just leave the MP lock held once it has been
691 ++gd->gd_intr_nesting_level;
693 must_schedule = info->i_slow;
698 TD_INVARIANTS_GET(td);
699 list = &info->i_reclist;
701 for (rec = *list; rec; rec = nrec) {
702 /* rec may be invalid after call */
705 if (rec->intr_flags & INTR_CLOCK) {
707 if ((rec->intr_flags & INTR_MPSAFE) == 0 && got_mplock == 0) {
708 if (try_mplock() == 0) {
709 /* Couldn't get the MP lock; just schedule it. */
716 if (rec->serializer) {
717 must_schedule += lwkt_serialize_handler_try(
718 rec->serializer, rec->handler,
719 rec->argument, frame);
721 rec->handler(rec->argument, frame);
723 TD_INVARIANTS_TEST(td, rec->name);
730 --gd->gd_intr_nesting_level;
737 * If we had a problem, or mixed fast and slow interrupt handlers are
738 * registered, schedule the ithread to catch the missed records (it
739 * will just re-run all of them). A return value of 0 indicates that
740 * all handlers have been run and the interrupt can be re-enabled, and
741 * a non-zero return indicates that the interrupt thread controls
744 if (must_schedule > 0)
745 ithread_fast_sched(intr, td);
746 else if (must_schedule == 0)
748 return(must_schedule);
752 * Interrupt threads run this as their main loop.
754 * The handler begins execution outside a critical section and no MP lock.
756 * The i_running state starts at 0. When an interrupt occurs, the hardware
757 * interrupt is disabled and sched_ithd_hard() The HW interrupt remains
758 * disabled until all routines have run. We then call ithread_done() to
759 * reenable the HW interrupt and deschedule us until the next interrupt.
761 * We are responsible for atomically checking i_running and ithread_done()
762 * is responsible for atomically checking for platform-specific delayed
763 * interrupts. i_running for our irq is only set in the context of our cpu,
764 * so a critical section is a sufficient interlock.
766 #define LIVELOCK_TIMEFRAME(freq) ((freq) >> 2) /* 1/4 second */
769 ithread_handler(void *arg)
771 struct intr_info *info;
774 int intr, cpuid = mycpuid;
776 struct intrec **list;
779 struct systimer ill_timer; /* enforced freq. timer */
780 u_int ill_count; /* interrupt livelock counter */
781 TD_INVARIANTS_DECLARE;
784 intr = (int)(intptr_t)arg;
785 info = &intr_info_ary[cpuid][intr];
786 list = &info->i_reclist;
789 * The loop must be entered with one critical section held. The thread
790 * does not hold the mplock on startup.
793 lseconds = gd->gd_time_seconds;
799 * The chain is only considered MPSAFE if all its interrupt handlers
800 * are MPSAFE. However, if intr_mpsafe has been turned off we
801 * always operate with the BGL.
804 if (info->i_mplock_required != mpheld) {
805 if (info->i_mplock_required) {
806 KKASSERT(mpheld == 0);
810 KKASSERT(mpheld != 0);
817 TD_INVARIANTS_GET(gd->gd_curthread);
820 * If an interrupt is pending, clear i_running and execute the
821 * handlers. Note that certain types of interrupts can re-trigger
822 * and set i_running again.
824 * Each handler is run in a critical section. Note that we run both
825 * FAST and SLOW designated service routines.
827 if (info->i_running) {
832 report_stray_interrupt(info, "ithread_handler");
834 for (rec = *list; rec; rec = nrec) {
835 /* rec may be invalid after call */
837 if (rec->serializer) {
838 lwkt_serialize_handler_call(rec->serializer, rec->handler,
839 rec->argument, NULL);
841 rec->handler(rec->argument, NULL);
843 TD_INVARIANTS_TEST(gd->gd_curthread, rec->name);
848 * This is our interrupt hook to add rate randomness to the random
851 if (info->i_random.sc_enabled > 0)
852 add_interrupt_randomness(intr);
855 * Unmask the interrupt to allow it to trigger again. This only
856 * applies to certain types of interrupts (typ level interrupts).
857 * This can result in the interrupt retriggering, but the retrigger
858 * will not be processed until we cycle our critical section.
860 * Only unmask interrupts while handlers are installed. It is
861 * possible to hit a situation where no handlers are installed
862 * due to a device driver livelocking and then tearing down its
863 * interrupt on close (the parallel bus being a good example).
865 if (intr < FIRST_SOFTINT && *list)
866 machintr_intr_enable(intr);
869 * Do a quick exit/enter to catch any higher-priority interrupt
870 * sources, such as the statclock, so thread time accounting
871 * will still work. This may also cause an interrupt to re-trigger.
877 * LIVELOCK STATE MACHINE
879 switch(info->i_state) {
882 * Reset the count each second.
884 if (lseconds != gd->gd_time_seconds) {
885 lseconds = gd->gd_time_seconds;
890 * If we did not exceed the frequency limit, we are done.
891 * If the interrupt has not retriggered we deschedule ourselves.
893 if (ill_count <= livelock_limit) {
894 if (info->i_running == 0) {
895 lwkt_deschedule_self(gd->gd_curthread);
902 * Otherwise we are livelocked. Set up a periodic systimer
903 * to wake the thread up at the limit frequency.
905 kprintf("intr %d on cpu%d at %d/%d hz, livelocked limit engaged!\n",
906 intr, cpuid, ill_count, livelock_limit);
907 info->i_state = ISTATE_LIVELOCKED;
908 if ((use_limit = livelock_limit) < 100)
910 else if (use_limit > 500000)
912 systimer_init_periodic_nq(&ill_timer, ithread_livelock_wakeup,
913 (void *)(intptr_t)intr, use_limit);
915 case ISTATE_LIVELOCKED:
917 * Wait for our periodic timer to go off. Since the interrupt
918 * has re-armed it can still set i_running, but it will not
919 * reschedule us while we are in a livelocked state.
921 lwkt_deschedule_self(gd->gd_curthread);
925 * Check once a second to see if the livelock condition no
928 if (lseconds != gd->gd_time_seconds) {
929 lseconds = gd->gd_time_seconds;
930 if (ill_count < livelock_lowater) {
931 info->i_state = ISTATE_NORMAL;
932 systimer_del(&ill_timer);
933 kprintf("intr %d on cpu%d at %d/%d hz, livelock removed\n",
934 intr, cpuid, ill_count, livelock_lowater);
935 } else if (livelock_debug == intr ||
936 (bootverbose && cold)) {
937 kprintf("intr %d on cpu%d at %d/%d hz, in livelock\n",
938 intr, cpuid, ill_count, livelock_lowater);
949 * Emergency interrupt polling thread. The thread begins execution
950 * outside a critical section with the BGL held.
952 * If emergency interrupt polling is enabled, this thread will
953 * execute all system interrupts not marked INTR_NOPOLL at the
954 * specified polling frequency.
956 * WARNING! This thread runs *ALL* interrupt service routines that
957 * are not marked INTR_NOPOLL, which basically means everything except
958 * the 8254 clock interrupt and the ATA interrupt. It has very high
959 * overhead and should only be used in situations where the machine
960 * cannot otherwise be made to work. Due to the severe performance
961 * degredation, it should not be enabled on production machines.
964 ithread_emergency(void *arg __unused)
966 globaldata_t gd = mycpu;
967 struct intr_info *info;
969 int intr, cpuid = mycpuid;
970 TD_INVARIANTS_DECLARE;
974 TD_INVARIANTS_GET(gd->gd_curthread);
977 for (intr = 0; intr < max_installed_hard_intr[cpuid]; ++intr) {
978 info = &intr_info_ary[cpuid][intr];
979 for (rec = info->i_reclist; rec; rec = nrec) {
980 /* rec may be invalid after call */
982 if ((rec->intr_flags & INTR_NOPOLL) == 0) {
983 if (rec->serializer) {
984 lwkt_serialize_handler_try(rec->serializer,
985 rec->handler, rec->argument, NULL);
987 rec->handler(rec->argument, NULL);
989 TD_INVARIANTS_TEST(gd->gd_curthread, rec->name);
993 lwkt_deschedule_self(gd->gd_curthread);
1000 * Systimer callback - schedule the emergency interrupt poll thread
1001 * if emergency polling is enabled.
1005 emergency_intr_timer_callback(systimer_t info, int in_ipi __unused,
1006 struct intrframe *frame __unused)
1008 if (emergency_intr_enable)
1009 lwkt_schedule(info->data);
1013 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
1014 * The data for this machine dependent, and the declarations are in machine
1015 * dependent code. The layout of intrnames and intrcnt however is machine
1018 * We do not know the length of intrcnt and intrnames at compile time, so
1019 * calculate things at run time.
1023 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
1025 struct intr_info *info;
1032 for (cpuid = 0; cpuid < ncpus; ++cpuid) {
1033 for (intr = 0; error == 0 && intr < MAX_INTS; ++intr) {
1034 info = &intr_info_ary[cpuid][intr];
1038 for (rec = info->i_reclist; rec; rec = rec->next) {
1039 ksnprintf(buf + len, sizeof(buf) - len, "%s%s",
1040 (len ? "/" : ""), rec->name);
1041 len += strlen(buf + len);
1044 ksnprintf(buf, sizeof(buf), "irq%d", intr);
1047 error = SYSCTL_OUT(req, buf, len + 1);
1053 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
1054 NULL, 0, sysctl_intrnames, "", "Interrupt Names");
1057 sysctl_intrcnt_all(SYSCTL_HANDLER_ARGS)
1059 struct intr_info *info;
1063 for (cpuid = 0; cpuid < ncpus; ++cpuid) {
1064 for (intr = 0; intr < MAX_INTS; ++intr) {
1065 info = &intr_info_ary[cpuid][intr];
1067 error = SYSCTL_OUT(req, &info->i_count, sizeof(info->i_count));
1076 SYSCTL_PROC(_hw, OID_AUTO, intrcnt_all, CTLTYPE_OPAQUE | CTLFLAG_RD,
1077 NULL, 0, sysctl_intrcnt_all, "", "Interrupt Counts");
1079 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
1080 NULL, 0, sysctl_intrcnt_all, "", "Interrupt Counts");
1083 int_moveto_destcpu(int *orig_cpuid0, int cpuid)
1085 int orig_cpuid = mycpuid;
1087 if (cpuid != orig_cpuid)
1088 lwkt_migratecpu(cpuid);
1090 *orig_cpuid0 = orig_cpuid;
1094 int_moveto_origcpu(int orig_cpuid, int cpuid)
1096 if (cpuid != orig_cpuid)
1097 lwkt_migratecpu(orig_cpuid);
1101 intr_init(void *dummy __unused)
1105 kprintf("Initialize MI interrupts\n");
1107 for (cpuid = 0; cpuid < ncpus; ++cpuid) {
1110 for (intr = 0; intr < MAX_INTS; ++intr) {
1111 struct intr_info *info = &intr_info_ary[cpuid][intr];
1113 info->i_cpuid = cpuid;
1114 info->i_intr = intr;
1118 SYSINIT(intr_init, SI_BOOT2_FINISH_PIC, SI_ORDER_ANY, intr_init, NULL);