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 $
27 * $DragonFly: src/sys/kern/kern_intr.c,v 1.55 2008/09/01 12:49:00 sephe Exp $
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/malloc.h>
34 #include <sys/kernel.h>
35 #include <sys/sysctl.h>
36 #include <sys/thread.h>
38 #include <sys/random.h>
39 #include <sys/serialize.h>
40 #include <sys/interrupt.h>
42 #include <sys/machintr.h>
44 #include <machine/frame.h>
46 #include <sys/interrupt.h>
48 #include <sys/thread2.h>
49 #include <sys/mplock2.h>
53 typedef struct intrec {
55 struct intr_info *info;
61 struct lwkt_serialize *serializer;
66 struct thread i_thread;
67 struct random_softc i_random;
69 long i_count; /* interrupts dispatched */
70 int i_mplock_required;
75 unsigned long i_straycount;
76 } intr_info_ary[MAX_INTS];
78 int max_installed_hard_intr;
79 int max_installed_soft_intr;
81 #define EMERGENCY_INTR_POLLING_FREQ_MAX 20000
84 * Assert that callers into interrupt handlers don't return with
85 * dangling tokens, spinlocks, or mp locks.
89 /* INVARIANTS & SMP */
90 # define SMP_INVARIANTS_DECLARE \
93 # define SMP_INVARIANTS_GET(td) \
94 mpcount = (td)->td_mpcount
96 # define SMP_INVARIANTS_TEST(td, name) \
97 KASSERT(mpcount == (td)->td_mpcount, \
98 ("mpcount mismatch after interrupt handler %s", \
101 # define SMP_INVARIANTS_ADJMP(count) \
105 /* INVARIANTS & !SMP */
106 # define SMP_INVARIANTS_DECLARE
107 # define SMP_INVARIANTS_GET(td)
108 # define SMP_INVARIANTS_TEST(td, name)
110 # endif /* ndef SMP */
112 #define TD_INVARIANTS_DECLARE \
113 SMP_INVARIANTS_DECLARE \
115 lwkt_tokref_t curstop
117 #define TD_INVARIANTS_GET(td) \
119 SMP_INVARIANTS_GET(td); \
120 spincount = (td)->td_gd->gd_spinlocks_wr; \
121 curstop = (td)->td_toks_stop; \
124 #define TD_INVARIANTS_TEST(td, name) \
126 KASSERT(spincount == (td)->td_gd->gd_spinlocks_wr, \
127 ("spincount mismatch after interrupt handler %s", \
129 KASSERT(curstop == (td)->td_toks_stop, \
130 ("token count mismatch after interrupt handler %s", \
132 SMP_INVARIANTS_TEST(td, name); \
138 /* !INVARIANTS & SMP */
139 # define SMP_INVARIANTS_ADJMP(count)
143 #define TD_INVARIANTS_DECLARE
144 #define TD_INVARIANTS_GET(td)
145 #define TD_INVARIANTS_TEST(td, name)
147 #endif /* ndef INVARIANTS */
149 static int sysctl_emergency_freq(SYSCTL_HANDLER_ARGS);
150 static int sysctl_emergency_enable(SYSCTL_HANDLER_ARGS);
151 static void emergency_intr_timer_callback(systimer_t, struct intrframe *);
152 static void ithread_handler(void *arg);
153 static void ithread_emergency(void *arg);
154 static void report_stray_interrupt(int intr, struct intr_info *info);
155 static void int_moveto_destcpu(int *, int *, int);
156 static void int_moveto_origcpu(int, int);
158 int intr_info_size = sizeof(intr_info_ary) / sizeof(intr_info_ary[0]);
160 static struct systimer emergency_intr_timer;
161 static struct thread emergency_intr_thread;
163 #define ISTATE_NOTHREAD 0
164 #define ISTATE_NORMAL 1
165 #define ISTATE_LIVELOCKED 2
167 static int livelock_limit = 40000;
168 static int livelock_lowater = 20000;
169 static int livelock_debug = -1;
170 SYSCTL_INT(_kern, OID_AUTO, livelock_limit,
171 CTLFLAG_RW, &livelock_limit, 0, "Livelock interrupt rate limit");
172 SYSCTL_INT(_kern, OID_AUTO, livelock_lowater,
173 CTLFLAG_RW, &livelock_lowater, 0, "Livelock low-water mark restore");
174 SYSCTL_INT(_kern, OID_AUTO, livelock_debug,
175 CTLFLAG_RW, &livelock_debug, 0, "Livelock debug intr#");
177 static int emergency_intr_enable = 0; /* emergency interrupt polling */
178 TUNABLE_INT("kern.emergency_intr_enable", &emergency_intr_enable);
179 SYSCTL_PROC(_kern, OID_AUTO, emergency_intr_enable, CTLTYPE_INT | CTLFLAG_RW,
180 0, 0, sysctl_emergency_enable, "I", "Emergency Interrupt Poll Enable");
182 static int emergency_intr_freq = 10; /* emergency polling frequency */
183 TUNABLE_INT("kern.emergency_intr_freq", &emergency_intr_freq);
184 SYSCTL_PROC(_kern, OID_AUTO, emergency_intr_freq, CTLTYPE_INT | CTLFLAG_RW,
185 0, 0, sysctl_emergency_freq, "I", "Emergency Interrupt Poll Frequency");
188 * Sysctl support routines
191 sysctl_emergency_enable(SYSCTL_HANDLER_ARGS)
195 enabled = emergency_intr_enable;
196 error = sysctl_handle_int(oidp, &enabled, 0, req);
197 if (error || req->newptr == NULL)
199 emergency_intr_enable = enabled;
200 if (emergency_intr_enable) {
201 systimer_adjust_periodic(&emergency_intr_timer,
202 emergency_intr_freq);
204 systimer_adjust_periodic(&emergency_intr_timer, 1);
210 sysctl_emergency_freq(SYSCTL_HANDLER_ARGS)
214 phz = emergency_intr_freq;
215 error = sysctl_handle_int(oidp, &phz, 0, req);
216 if (error || req->newptr == NULL)
220 else if (phz > EMERGENCY_INTR_POLLING_FREQ_MAX)
221 phz = EMERGENCY_INTR_POLLING_FREQ_MAX;
223 emergency_intr_freq = phz;
224 if (emergency_intr_enable) {
225 systimer_adjust_periodic(&emergency_intr_timer,
226 emergency_intr_freq);
228 systimer_adjust_periodic(&emergency_intr_timer, 1);
234 * Register an SWI or INTerrupt handler.
237 register_swi(int intr, inthand2_t *handler, void *arg, const char *name,
238 struct lwkt_serialize *serializer)
240 if (intr < FIRST_SOFTINT || intr >= MAX_INTS)
241 panic("register_swi: bad intr %d", intr);
242 return(register_int(intr, handler, arg, name, serializer, 0));
246 register_swi_mp(int intr, inthand2_t *handler, void *arg, const char *name,
247 struct lwkt_serialize *serializer)
249 if (intr < FIRST_SOFTINT || intr >= MAX_INTS)
250 panic("register_swi: bad intr %d", intr);
251 return(register_int(intr, handler, arg, name, serializer, INTR_MPSAFE));
255 register_int(int intr, inthand2_t *handler, void *arg, const char *name,
256 struct lwkt_serialize *serializer, int intr_flags)
258 struct intr_info *info;
259 struct intrec **list;
261 int orig_cpuid, cpuid;
263 if (intr < 0 || intr >= MAX_INTS)
264 panic("register_int: bad intr %d", intr);
267 info = &intr_info_ary[intr];
270 * Construct an interrupt handler record
272 rec = kmalloc(sizeof(struct intrec), M_DEVBUF, M_INTWAIT);
273 rec->name = kmalloc(strlen(name) + 1, M_DEVBUF, M_INTWAIT);
274 strcpy(rec->name, name);
277 rec->handler = handler;
280 rec->intr_flags = intr_flags;
282 rec->serializer = serializer;
285 * Create an emergency polling thread and set up a systimer to wake
288 if (emergency_intr_thread.td_kstack == NULL) {
289 lwkt_create(ithread_emergency, NULL, NULL, &emergency_intr_thread,
290 TDF_STOPREQ | TDF_INTTHREAD, -1, "ithread emerg");
291 systimer_init_periodic_nq(&emergency_intr_timer,
292 emergency_intr_timer_callback, &emergency_intr_thread,
293 (emergency_intr_enable ? emergency_intr_freq : 1));
296 int_moveto_destcpu(&orig_cpuid, &cpuid, intr);
299 * Create an interrupt thread if necessary, leave it in an unscheduled
302 if (info->i_state == ISTATE_NOTHREAD) {
303 info->i_state = ISTATE_NORMAL;
304 lwkt_create(ithread_handler, (void *)(intptr_t)intr, NULL,
305 &info->i_thread, TDF_STOPREQ | TDF_INTTHREAD, -1,
307 if (intr >= FIRST_SOFTINT)
308 lwkt_setpri(&info->i_thread, TDPRI_SOFT_NORM);
310 lwkt_setpri(&info->i_thread, TDPRI_INT_MED);
311 info->i_thread.td_preemptable = lwkt_preempt;
314 list = &info->i_reclist;
317 * Keep track of how many fast and slow interrupts we have.
318 * Set i_mplock_required if any handler in the chain requires
319 * the MP lock to operate.
321 if ((intr_flags & INTR_MPSAFE) == 0)
322 info->i_mplock_required = 1;
323 if (intr_flags & INTR_CLOCK)
329 * Enable random number generation keying off of this interrupt.
331 if ((intr_flags & INTR_NOENTROPY) == 0 && info->i_random.sc_enabled == 0) {
332 info->i_random.sc_enabled = 1;
333 info->i_random.sc_intr = intr;
337 * Add the record to the interrupt list.
340 while (*list != NULL)
341 list = &(*list)->next;
346 * Update max_installed_hard_intr to make the emergency intr poll
347 * a bit more efficient.
349 if (intr < FIRST_SOFTINT) {
350 if (max_installed_hard_intr <= intr)
351 max_installed_hard_intr = intr + 1;
353 if (max_installed_soft_intr <= intr)
354 max_installed_soft_intr = intr + 1;
358 * Setup the machine level interrupt vector
360 * XXX temporary workaround for some ACPI brokedness. ACPI installs
361 * its interrupt too early, before the IOAPICs have been configured,
362 * which means the IOAPIC is not enabled by the registration of the
363 * ACPI interrupt. Anything else sharing that IRQ will wind up not
364 * being enabled. Temporarily work around the problem by always
365 * installing and enabling on every new interrupt handler, even
366 * if one has already been setup on that irq.
368 if (intr < FIRST_SOFTINT /* && info->i_slow + info->i_fast == 1*/) {
369 if (machintr_vector_setup(intr, intr_flags))
370 kprintf("machintr_vector_setup: failed on irq %d\n", intr);
373 int_moveto_origcpu(orig_cpuid, cpuid);
379 unregister_swi(void *id)
385 unregister_int(void *id)
387 struct intr_info *info;
388 struct intrec **list;
390 int intr, orig_cpuid, cpuid;
392 intr = ((intrec_t)id)->intr;
394 if (intr < 0 || intr >= MAX_INTS)
395 panic("register_int: bad intr %d", intr);
397 info = &intr_info_ary[intr];
399 int_moveto_destcpu(&orig_cpuid, &cpuid, intr);
402 * Remove the interrupt descriptor, adjust the descriptor count,
403 * and teardown the machine level vector if this was the last interrupt.
406 list = &info->i_reclist;
407 while ((rec = *list) != NULL) {
416 if (rec->intr_flags & INTR_CLOCK)
420 if (intr < FIRST_SOFTINT && info->i_fast + info->i_slow == 0)
421 machintr_vector_teardown(intr);
424 * Clear i_mplock_required if no handlers in the chain require the
427 for (rec0 = info->i_reclist; rec0; rec0 = rec0->next) {
428 if ((rec0->intr_flags & INTR_MPSAFE) == 0)
432 info->i_mplock_required = 0;
437 int_moveto_origcpu(orig_cpuid, cpuid);
443 kfree(rec->name, M_DEVBUF);
444 kfree(rec, M_DEVBUF);
446 kprintf("warning: unregister_int: int %d handler for %s not found\n",
447 intr, ((intrec_t)id)->name);
452 get_registered_name(int intr)
456 if (intr < 0 || intr >= MAX_INTS)
457 panic("register_int: bad intr %d", intr);
459 if ((rec = intr_info_ary[intr].i_reclist) == NULL)
468 count_registered_ints(int intr)
470 struct intr_info *info;
472 if (intr < 0 || intr >= MAX_INTS)
473 panic("register_int: bad intr %d", intr);
474 info = &intr_info_ary[intr];
475 return(info->i_fast + info->i_slow);
479 get_interrupt_counter(int intr)
481 struct intr_info *info;
483 if (intr < 0 || intr >= MAX_INTS)
484 panic("register_int: bad intr %d", intr);
485 info = &intr_info_ary[intr];
486 return(info->i_count);
491 swi_setpriority(int intr, int pri)
493 struct intr_info *info;
495 if (intr < FIRST_SOFTINT || intr >= MAX_INTS)
496 panic("register_swi: bad intr %d", intr);
497 info = &intr_info_ary[intr];
498 if (info->i_state != ISTATE_NOTHREAD)
499 lwkt_setpri(&info->i_thread, pri);
503 register_randintr(int intr)
505 struct intr_info *info;
507 if (intr < 0 || intr >= MAX_INTS)
508 panic("register_randintr: bad intr %d", intr);
509 info = &intr_info_ary[intr];
510 info->i_random.sc_intr = intr;
511 info->i_random.sc_enabled = 1;
515 unregister_randintr(int intr)
517 struct intr_info *info;
519 if (intr < 0 || intr >= MAX_INTS)
520 panic("register_swi: bad intr %d", intr);
521 info = &intr_info_ary[intr];
522 info->i_random.sc_enabled = -1;
526 next_registered_randintr(int intr)
528 struct intr_info *info;
530 if (intr < 0 || intr >= MAX_INTS)
531 panic("register_swi: bad intr %d", intr);
532 while (intr < MAX_INTS) {
533 info = &intr_info_ary[intr];
534 if (info->i_random.sc_enabled > 0)
542 * Dispatch an interrupt. If there's nothing to do we have a stray
543 * interrupt and can just return, leaving the interrupt masked.
545 * We need to schedule the interrupt and set its i_running bit. If
546 * we are not on the interrupt thread's cpu we have to send a message
547 * to the correct cpu that will issue the desired action (interlocking
548 * with the interrupt thread's critical section). We do NOT attempt to
549 * reschedule interrupts whos i_running bit is already set because
550 * this would prematurely wakeup a livelock-limited interrupt thread.
552 * i_running is only tested/set on the same cpu as the interrupt thread.
554 * We are NOT in a critical section, which will allow the scheduled
555 * interrupt to preempt us. The MP lock might *NOT* be held here.
560 sched_ithd_remote(void *arg)
562 sched_ithd((int)(intptr_t)arg);
570 struct intr_info *info;
572 info = &intr_info_ary[intr];
575 if (info->i_state != ISTATE_NOTHREAD) {
576 if (info->i_reclist == NULL) {
577 report_stray_interrupt(intr, info);
580 if (info->i_thread.td_gd == mycpu) {
581 if (info->i_running == 0) {
583 if (info->i_state != ISTATE_LIVELOCKED)
584 lwkt_schedule(&info->i_thread); /* MIGHT PREEMPT */
587 lwkt_send_ipiq(info->i_thread.td_gd,
588 sched_ithd_remote, (void *)(intptr_t)intr);
591 if (info->i_running == 0) {
593 if (info->i_state != ISTATE_LIVELOCKED)
594 lwkt_schedule(&info->i_thread); /* MIGHT PREEMPT */
599 report_stray_interrupt(intr, info);
604 report_stray_interrupt(int intr, struct intr_info *info)
606 ++info->i_straycount;
607 if (info->i_straycount < 10) {
608 if (info->i_errorticks == ticks)
610 info->i_errorticks = ticks;
611 kprintf("sched_ithd: stray interrupt %d on cpu %d\n",
613 } else if (info->i_straycount == 10) {
614 kprintf("sched_ithd: %ld stray interrupts %d on cpu %d - "
615 "there will be no further reports\n",
616 info->i_straycount, intr, mycpuid);
621 * This is run from a periodic SYSTIMER (and thus must be MP safe, the BGL
622 * might not be held).
625 ithread_livelock_wakeup(systimer_t st)
627 struct intr_info *info;
629 info = &intr_info_ary[(int)(intptr_t)st->data];
630 if (info->i_state != ISTATE_NOTHREAD)
631 lwkt_schedule(&info->i_thread);
635 * Schedule ithread within fast intr handler
637 * XXX Protect sched_ithd() call with gd_intr_nesting_level?
638 * Interrupts aren't enabled, but still...
641 ithread_fast_sched(int intr, thread_t td)
646 * We are already in critical section, exit it now to
651 crit_enter_quick(td);
657 * This function is called directly from the ICU or APIC vector code assembly
658 * to process an interrupt. The critical section and interrupt deferral
659 * checks have already been done but the function is entered WITHOUT
660 * a critical section held. The BGL may or may not be held.
662 * Must return non-zero if we do not want the vector code to re-enable
663 * the interrupt (which we don't if we have to schedule the interrupt)
665 int ithread_fast_handler(struct intrframe *frame);
668 ithread_fast_handler(struct intrframe *frame)
671 struct intr_info *info;
672 struct intrec **list;
677 TD_INVARIANTS_DECLARE;
678 intrec_t rec, next_rec;
682 intr = frame->if_vec;
686 /* We must be in critical section. */
687 KKASSERT(td->td_critcount);
689 info = &intr_info_ary[intr];
692 * If we are not processing any FAST interrupts, just schedule the thing.
694 if (info->i_fast == 0) {
696 ithread_fast_sched(intr, td);
701 * This should not normally occur since interrupts ought to be
702 * masked if the ithread has been scheduled or is running.
708 * Bump the interrupt nesting level to process any FAST interrupts.
709 * Obtain the MP lock as necessary. If the MP lock cannot be obtained,
710 * schedule the interrupt thread to deal with the issue instead.
712 * To reduce overhead, just leave the MP lock held once it has been
715 ++gd->gd_intr_nesting_level;
717 must_schedule = info->i_slow;
722 TD_INVARIANTS_GET(td);
723 list = &info->i_reclist;
725 for (rec = *list; rec; rec = next_rec) {
726 next_rec = rec->next; /* rec may be invalid after call */
728 if (rec->intr_flags & INTR_CLOCK) {
730 if ((rec->intr_flags & INTR_MPSAFE) == 0 && got_mplock == 0) {
731 if (try_mplock() == 0) {
732 /* Couldn't get the MP lock; just schedule it. */
737 SMP_INVARIANTS_ADJMP(1);
740 if (rec->serializer) {
741 must_schedule += lwkt_serialize_handler_try(
742 rec->serializer, rec->handler,
743 rec->argument, frame);
745 rec->handler(rec->argument, frame);
747 TD_INVARIANTS_TEST(td, rec->name);
754 --gd->gd_intr_nesting_level;
761 * If we had a problem, or mixed fast and slow interrupt handlers are
762 * registered, schedule the ithread to catch the missed records (it
763 * will just re-run all of them). A return value of 0 indicates that
764 * all handlers have been run and the interrupt can be re-enabled, and
765 * a non-zero return indicates that the interrupt thread controls
768 if (must_schedule > 0)
769 ithread_fast_sched(intr, td);
770 else if (must_schedule == 0)
772 return(must_schedule);
776 * Interrupt threads run this as their main loop.
778 * The handler begins execution outside a critical section and no MP lock.
780 * The i_running state starts at 0. When an interrupt occurs, the hardware
781 * interrupt is disabled and sched_ithd() The HW interrupt remains disabled
782 * until all routines have run. We then call ithread_done() to reenable
783 * the HW interrupt and deschedule us until the next interrupt.
785 * We are responsible for atomically checking i_running and ithread_done()
786 * is responsible for atomically checking for platform-specific delayed
787 * interrupts. i_running for our irq is only set in the context of our cpu,
788 * so a critical section is a sufficient interlock.
790 #define LIVELOCK_TIMEFRAME(freq) ((freq) >> 2) /* 1/4 second */
793 ithread_handler(void *arg)
795 struct intr_info *info;
800 struct intrec **list;
803 struct systimer ill_timer; /* enforced freq. timer */
804 u_int ill_count; /* interrupt livelock counter */
805 TD_INVARIANTS_DECLARE;
808 intr = (int)(intptr_t)arg;
809 info = &intr_info_ary[intr];
810 list = &info->i_reclist;
813 * The loop must be entered with one critical section held. The thread
814 * does not hold the mplock on startup.
817 lseconds = gd->gd_time_seconds;
823 * The chain is only considered MPSAFE if all its interrupt handlers
824 * are MPSAFE. However, if intr_mpsafe has been turned off we
825 * always operate with the BGL.
828 if (info->i_mplock_required != mpheld) {
829 if (info->i_mplock_required) {
830 KKASSERT(mpheld == 0);
834 KKASSERT(mpheld != 0);
841 TD_INVARIANTS_GET(gd->gd_curthread);
844 * If an interrupt is pending, clear i_running and execute the
845 * handlers. Note that certain types of interrupts can re-trigger
846 * and set i_running again.
848 * Each handler is run in a critical section. Note that we run both
849 * FAST and SLOW designated service routines.
851 if (info->i_running) {
856 report_stray_interrupt(intr, info);
858 for (rec = *list; rec; rec = nrec) {
860 if (rec->serializer) {
861 lwkt_serialize_handler_call(rec->serializer, rec->handler,
862 rec->argument, NULL);
864 rec->handler(rec->argument, NULL);
866 TD_INVARIANTS_TEST(gd->gd_curthread, rec->name);
871 * This is our interrupt hook to add rate randomness to the random
874 if (info->i_random.sc_enabled > 0)
875 add_interrupt_randomness(intr);
878 * Unmask the interrupt to allow it to trigger again. This only
879 * applies to certain types of interrupts (typ level interrupts).
880 * This can result in the interrupt retriggering, but the retrigger
881 * will not be processed until we cycle our critical section.
883 * Only unmask interrupts while handlers are installed. It is
884 * possible to hit a situation where no handlers are installed
885 * due to a device driver livelocking and then tearing down its
886 * interrupt on close (the parallel bus being a good example).
889 machintr_intren(intr);
892 * Do a quick exit/enter to catch any higher-priority interrupt
893 * sources, such as the statclock, so thread time accounting
894 * will still work. This may also cause an interrupt to re-trigger.
900 * LIVELOCK STATE MACHINE
902 switch(info->i_state) {
905 * Reset the count each second.
907 if (lseconds != gd->gd_time_seconds) {
908 lseconds = gd->gd_time_seconds;
913 * If we did not exceed the frequency limit, we are done.
914 * If the interrupt has not retriggered we deschedule ourselves.
916 if (ill_count <= livelock_limit) {
917 if (info->i_running == 0) {
918 lwkt_deschedule_self(gd->gd_curthread);
925 * Otherwise we are livelocked. Set up a periodic systimer
926 * to wake the thread up at the limit frequency.
928 kprintf("intr %d at %d/%d hz, livelocked limit engaged!\n",
929 intr, ill_count, livelock_limit);
930 info->i_state = ISTATE_LIVELOCKED;
931 if ((use_limit = livelock_limit) < 100)
933 else if (use_limit > 500000)
935 systimer_init_periodic_nq(&ill_timer, ithread_livelock_wakeup,
936 (void *)(intptr_t)intr, use_limit);
938 case ISTATE_LIVELOCKED:
940 * Wait for our periodic timer to go off. Since the interrupt
941 * has re-armed it can still set i_running, but it will not
942 * reschedule us while we are in a livelocked state.
944 lwkt_deschedule_self(gd->gd_curthread);
948 * Check once a second to see if the livelock condition no
951 if (lseconds != gd->gd_time_seconds) {
952 lseconds = gd->gd_time_seconds;
953 if (ill_count < livelock_lowater) {
954 info->i_state = ISTATE_NORMAL;
955 systimer_del(&ill_timer);
956 kprintf("intr %d at %d/%d hz, livelock removed\n",
957 intr, ill_count, livelock_lowater);
958 } else if (livelock_debug == intr ||
959 (bootverbose && cold)) {
960 kprintf("intr %d at %d/%d hz, in livelock\n",
961 intr, ill_count, livelock_lowater);
972 * Emergency interrupt polling thread. The thread begins execution
973 * outside a critical section with the BGL held.
975 * If emergency interrupt polling is enabled, this thread will
976 * execute all system interrupts not marked INTR_NOPOLL at the
977 * specified polling frequency.
979 * WARNING! This thread runs *ALL* interrupt service routines that
980 * are not marked INTR_NOPOLL, which basically means everything except
981 * the 8254 clock interrupt and the ATA interrupt. It has very high
982 * overhead and should only be used in situations where the machine
983 * cannot otherwise be made to work. Due to the severe performance
984 * degredation, it should not be enabled on production machines.
987 ithread_emergency(void *arg __unused)
989 struct intr_info *info;
992 thread_t td __debugvar = curthread;
993 TD_INVARIANTS_DECLARE;
996 TD_INVARIANTS_GET(td);
999 for (intr = 0; intr < max_installed_hard_intr; ++intr) {
1000 info = &intr_info_ary[intr];
1001 for (rec = info->i_reclist; rec; rec = nrec) {
1002 if ((rec->intr_flags & INTR_NOPOLL) == 0) {
1003 if (rec->serializer) {
1004 lwkt_serialize_handler_call(rec->serializer,
1005 rec->handler, rec->argument, NULL);
1007 rec->handler(rec->argument, NULL);
1009 TD_INVARIANTS_TEST(td, rec->name);
1014 lwkt_deschedule_self(curthread);
1020 * Systimer callback - schedule the emergency interrupt poll thread
1021 * if emergency polling is enabled.
1025 emergency_intr_timer_callback(systimer_t info, struct intrframe *frame __unused)
1027 if (emergency_intr_enable)
1028 lwkt_schedule(info->data);
1032 ithread_cpuid(int intr)
1034 const struct intr_info *info;
1036 KKASSERT(intr >= 0 && intr < MAX_INTS);
1037 info = &intr_info_ary[intr];
1039 if (info->i_state == ISTATE_NOTHREAD)
1041 return info->i_thread.td_gd->gd_cpuid;
1045 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
1046 * The data for this machine dependent, and the declarations are in machine
1047 * dependent code. The layout of intrnames and intrcnt however is machine
1050 * We do not know the length of intrcnt and intrnames at compile time, so
1051 * calculate things at run time.
1055 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
1057 struct intr_info *info;
1064 for (intr = 0; error == 0 && intr < MAX_INTS; ++intr) {
1065 info = &intr_info_ary[intr];
1069 for (rec = info->i_reclist; rec; rec = rec->next) {
1070 ksnprintf(buf + len, sizeof(buf) - len, "%s%s",
1071 (len ? "/" : ""), rec->name);
1072 len += strlen(buf + len);
1075 ksnprintf(buf, sizeof(buf), "irq%d", intr);
1078 error = SYSCTL_OUT(req, buf, len + 1);
1084 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
1085 NULL, 0, sysctl_intrnames, "", "Interrupt Names");
1088 sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
1090 struct intr_info *info;
1094 for (intr = 0; intr < max_installed_hard_intr; ++intr) {
1095 info = &intr_info_ary[intr];
1097 error = SYSCTL_OUT(req, &info->i_count, sizeof(info->i_count));
1101 for (intr = FIRST_SOFTINT; intr < max_installed_soft_intr; ++intr) {
1102 info = &intr_info_ary[intr];
1104 error = SYSCTL_OUT(req, &info->i_count, sizeof(info->i_count));
1112 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
1113 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
1116 int_moveto_destcpu(int *orig_cpuid0, int *cpuid0, int intr)
1118 int orig_cpuid = mycpuid, cpuid;
1122 ksnprintf(envpath, sizeof(envpath), "hw.irq.%d.dest", intr);
1123 kgetenv_int(envpath, &cpuid);
1127 if (cpuid != orig_cpuid)
1128 lwkt_migratecpu(cpuid);
1130 *orig_cpuid0 = orig_cpuid;
1135 int_moveto_origcpu(int orig_cpuid, int cpuid)
1137 if (cpuid != orig_cpuid)
1138 lwkt_migratecpu(orig_cpuid);