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/interrupt.h>
47 #include <sys/thread2.h>
48 #include <sys/mplock2.h>
52 typedef struct intrec {
54 struct intr_info *info;
60 struct lwkt_serialize *serializer;
65 struct thread i_thread;
66 struct random_softc i_random;
68 long i_count; /* interrupts dispatched */
69 int i_mplock_required;
74 unsigned long i_straycount;
75 } intr_info_ary[MAX_INTS];
77 int max_installed_hard_intr;
78 int max_installed_soft_intr;
80 #define EMERGENCY_INTR_POLLING_FREQ_MAX 20000
83 * Assert that callers into interrupt handlers don't return with
84 * dangling tokens, spinlocks, or mp locks.
88 #define TD_INVARIANTS_DECLARE \
92 #define TD_INVARIANTS_GET(td) \
94 spincount = (td)->td_gd->gd_spinlocks_wr; \
95 curstop = (td)->td_toks_stop; \
98 #define TD_INVARIANTS_TEST(td, name) \
100 KASSERT(spincount == (td)->td_gd->gd_spinlocks_wr, \
101 ("spincount mismatch after interrupt handler %s", \
103 KASSERT(curstop == (td)->td_toks_stop, \
104 ("token count mismatch after interrupt handler %s", \
112 #define TD_INVARIANTS_DECLARE
113 #define TD_INVARIANTS_GET(td)
114 #define TD_INVARIANTS_TEST(td, name)
116 #endif /* ndef INVARIANTS */
118 static int sysctl_emergency_freq(SYSCTL_HANDLER_ARGS);
119 static int sysctl_emergency_enable(SYSCTL_HANDLER_ARGS);
120 static void emergency_intr_timer_callback(systimer_t, int, struct intrframe *);
121 static void ithread_handler(void *arg);
122 static void ithread_emergency(void *arg);
123 static void report_stray_interrupt(int intr, struct intr_info *info);
124 static void int_moveto_destcpu(int *, int *, int);
125 static void int_moveto_origcpu(int, int);
127 int intr_info_size = NELEM(intr_info_ary);
129 static struct systimer emergency_intr_timer;
130 static struct thread emergency_intr_thread;
132 #define ISTATE_NOTHREAD 0
133 #define ISTATE_NORMAL 1
134 #define ISTATE_LIVELOCKED 2
136 static int livelock_limit = 40000;
137 static int livelock_lowater = 20000;
138 static int livelock_debug = -1;
139 SYSCTL_INT(_kern, OID_AUTO, livelock_limit,
140 CTLFLAG_RW, &livelock_limit, 0, "Livelock interrupt rate limit");
141 SYSCTL_INT(_kern, OID_AUTO, livelock_lowater,
142 CTLFLAG_RW, &livelock_lowater, 0, "Livelock low-water mark restore");
143 SYSCTL_INT(_kern, OID_AUTO, livelock_debug,
144 CTLFLAG_RW, &livelock_debug, 0, "Livelock debug intr#");
146 static int emergency_intr_enable = 0; /* emergency interrupt polling */
147 TUNABLE_INT("kern.emergency_intr_enable", &emergency_intr_enable);
148 SYSCTL_PROC(_kern, OID_AUTO, emergency_intr_enable, CTLTYPE_INT | CTLFLAG_RW,
149 0, 0, sysctl_emergency_enable, "I", "Emergency Interrupt Poll Enable");
151 static int emergency_intr_freq = 10; /* emergency polling frequency */
152 TUNABLE_INT("kern.emergency_intr_freq", &emergency_intr_freq);
153 SYSCTL_PROC(_kern, OID_AUTO, emergency_intr_freq, CTLTYPE_INT | CTLFLAG_RW,
154 0, 0, sysctl_emergency_freq, "I", "Emergency Interrupt Poll Frequency");
157 * Sysctl support routines
160 sysctl_emergency_enable(SYSCTL_HANDLER_ARGS)
164 enabled = emergency_intr_enable;
165 error = sysctl_handle_int(oidp, &enabled, 0, req);
166 if (error || req->newptr == NULL)
168 emergency_intr_enable = enabled;
169 if (emergency_intr_enable) {
170 systimer_adjust_periodic(&emergency_intr_timer,
171 emergency_intr_freq);
173 systimer_adjust_periodic(&emergency_intr_timer, 1);
179 sysctl_emergency_freq(SYSCTL_HANDLER_ARGS)
183 phz = emergency_intr_freq;
184 error = sysctl_handle_int(oidp, &phz, 0, req);
185 if (error || req->newptr == NULL)
189 else if (phz > EMERGENCY_INTR_POLLING_FREQ_MAX)
190 phz = EMERGENCY_INTR_POLLING_FREQ_MAX;
192 emergency_intr_freq = phz;
193 if (emergency_intr_enable) {
194 systimer_adjust_periodic(&emergency_intr_timer,
195 emergency_intr_freq);
197 systimer_adjust_periodic(&emergency_intr_timer, 1);
203 * Register an SWI or INTerrupt handler.
206 register_swi(int intr, inthand2_t *handler, void *arg, const char *name,
207 struct lwkt_serialize *serializer)
209 if (intr < FIRST_SOFTINT || intr >= MAX_INTS)
210 panic("register_swi: bad intr %d", intr);
211 return(register_int(intr, handler, arg, name, serializer, 0));
215 register_swi_mp(int intr, inthand2_t *handler, void *arg, const char *name,
216 struct lwkt_serialize *serializer)
218 if (intr < FIRST_SOFTINT || intr >= MAX_INTS)
219 panic("register_swi: bad intr %d", intr);
220 return(register_int(intr, handler, arg, name, serializer, INTR_MPSAFE));
224 register_int(int intr, inthand2_t *handler, void *arg, const char *name,
225 struct lwkt_serialize *serializer, int intr_flags)
227 struct intr_info *info;
228 struct intrec **list;
230 int orig_cpuid, cpuid;
232 if (intr < 0 || intr >= MAX_INTS)
233 panic("register_int: bad intr %d", intr);
236 info = &intr_info_ary[intr];
239 * Construct an interrupt handler record
241 rec = kmalloc(sizeof(struct intrec), M_DEVBUF, M_INTWAIT);
242 rec->name = kmalloc(strlen(name) + 1, M_DEVBUF, M_INTWAIT);
243 strcpy(rec->name, name);
246 rec->handler = handler;
249 rec->intr_flags = intr_flags;
251 rec->serializer = serializer;
254 * Create an emergency polling thread and set up a systimer to wake
257 if (emergency_intr_thread.td_kstack == NULL) {
258 lwkt_create(ithread_emergency, NULL, NULL, &emergency_intr_thread,
259 TDF_STOPREQ | TDF_INTTHREAD, -1, "ithread emerg");
260 systimer_init_periodic_nq(&emergency_intr_timer,
261 emergency_intr_timer_callback, &emergency_intr_thread,
262 (emergency_intr_enable ? emergency_intr_freq : 1));
265 int_moveto_destcpu(&orig_cpuid, &cpuid, intr);
268 * Create an interrupt thread if necessary, leave it in an unscheduled
271 if (info->i_state == ISTATE_NOTHREAD) {
272 info->i_state = ISTATE_NORMAL;
273 lwkt_create(ithread_handler, (void *)(intptr_t)intr, NULL,
274 &info->i_thread, TDF_STOPREQ | TDF_INTTHREAD, -1,
276 if (intr >= FIRST_SOFTINT)
277 lwkt_setpri(&info->i_thread, TDPRI_SOFT_NORM);
279 lwkt_setpri(&info->i_thread, TDPRI_INT_MED);
280 info->i_thread.td_preemptable = lwkt_preempt;
283 list = &info->i_reclist;
286 * Keep track of how many fast and slow interrupts we have.
287 * Set i_mplock_required if any handler in the chain requires
288 * the MP lock to operate.
290 if ((intr_flags & INTR_MPSAFE) == 0)
291 info->i_mplock_required = 1;
292 if (intr_flags & INTR_CLOCK)
298 * Enable random number generation keying off of this interrupt.
300 if ((intr_flags & INTR_NOENTROPY) == 0 && info->i_random.sc_enabled == 0) {
301 info->i_random.sc_enabled = 1;
302 info->i_random.sc_intr = intr;
306 * Add the record to the interrupt list.
309 while (*list != NULL)
310 list = &(*list)->next;
315 * Update max_installed_hard_intr to make the emergency intr poll
316 * a bit more efficient.
318 if (intr < FIRST_SOFTINT) {
319 if (max_installed_hard_intr <= intr)
320 max_installed_hard_intr = intr + 1;
322 if (max_installed_soft_intr <= intr)
323 max_installed_soft_intr = intr + 1;
327 * Setup the machine level interrupt vector
329 if (intr < FIRST_SOFTINT && info->i_slow + info->i_fast == 1)
330 machintr_intr_setup(intr, intr_flags);
332 int_moveto_origcpu(orig_cpuid, cpuid);
338 unregister_swi(void *id)
344 unregister_int(void *id)
346 struct intr_info *info;
347 struct intrec **list;
349 int intr, orig_cpuid, cpuid;
351 intr = ((intrec_t)id)->intr;
353 if (intr < 0 || intr >= MAX_INTS)
354 panic("register_int: bad intr %d", intr);
356 info = &intr_info_ary[intr];
358 int_moveto_destcpu(&orig_cpuid, &cpuid, intr);
361 * Remove the interrupt descriptor, adjust the descriptor count,
362 * and teardown the machine level vector if this was the last interrupt.
365 list = &info->i_reclist;
366 while ((rec = *list) != NULL) {
375 if (rec->intr_flags & INTR_CLOCK)
379 if (intr < FIRST_SOFTINT && info->i_fast + info->i_slow == 0)
380 machintr_intr_teardown(intr);
383 * Clear i_mplock_required if no handlers in the chain require the
386 for (rec0 = info->i_reclist; rec0; rec0 = rec0->next) {
387 if ((rec0->intr_flags & INTR_MPSAFE) == 0)
391 info->i_mplock_required = 0;
396 int_moveto_origcpu(orig_cpuid, cpuid);
402 kfree(rec->name, M_DEVBUF);
403 kfree(rec, M_DEVBUF);
405 kprintf("warning: unregister_int: int %d handler for %s not found\n",
406 intr, ((intrec_t)id)->name);
411 get_registered_name(int intr)
415 if (intr < 0 || intr >= MAX_INTS)
416 panic("register_int: bad intr %d", intr);
418 if ((rec = intr_info_ary[intr].i_reclist) == NULL)
427 count_registered_ints(int intr)
429 struct intr_info *info;
431 if (intr < 0 || intr >= MAX_INTS)
432 panic("register_int: bad intr %d", intr);
433 info = &intr_info_ary[intr];
434 return(info->i_fast + info->i_slow);
438 get_interrupt_counter(int intr)
440 struct intr_info *info;
442 if (intr < 0 || intr >= MAX_INTS)
443 panic("register_int: bad intr %d", intr);
444 info = &intr_info_ary[intr];
445 return(info->i_count);
450 swi_setpriority(int intr, int pri)
452 struct intr_info *info;
454 if (intr < FIRST_SOFTINT || intr >= MAX_INTS)
455 panic("register_swi: bad intr %d", intr);
456 info = &intr_info_ary[intr];
457 if (info->i_state != ISTATE_NOTHREAD)
458 lwkt_setpri(&info->i_thread, pri);
462 register_randintr(int intr)
464 struct intr_info *info;
466 if (intr < 0 || intr >= MAX_INTS)
467 panic("register_randintr: bad intr %d", intr);
468 info = &intr_info_ary[intr];
469 info->i_random.sc_intr = intr;
470 info->i_random.sc_enabled = 1;
474 unregister_randintr(int intr)
476 struct intr_info *info;
478 if (intr < 0 || intr >= MAX_INTS)
479 panic("register_swi: bad intr %d", intr);
480 info = &intr_info_ary[intr];
481 info->i_random.sc_enabled = -1;
485 next_registered_randintr(int intr)
487 struct intr_info *info;
489 if (intr < 0 || intr >= MAX_INTS)
490 panic("register_swi: bad intr %d", intr);
491 while (intr < MAX_INTS) {
492 info = &intr_info_ary[intr];
493 if (info->i_random.sc_enabled > 0)
501 * Dispatch an interrupt. If there's nothing to do we have a stray
502 * interrupt and can just return, leaving the interrupt masked.
504 * We need to schedule the interrupt and set its i_running bit. If
505 * we are not on the interrupt thread's cpu we have to send a message
506 * to the correct cpu that will issue the desired action (interlocking
507 * with the interrupt thread's critical section). We do NOT attempt to
508 * reschedule interrupts whos i_running bit is already set because
509 * this would prematurely wakeup a livelock-limited interrupt thread.
511 * i_running is only tested/set on the same cpu as the interrupt thread.
513 * We are NOT in a critical section, which will allow the scheduled
514 * interrupt to preempt us. The MP lock might *NOT* be held here.
519 sched_ithd_remote(void *arg)
521 sched_ithd((int)(intptr_t)arg);
529 struct intr_info *info;
531 info = &intr_info_ary[intr];
534 if (info->i_state != ISTATE_NOTHREAD) {
535 if (info->i_reclist == NULL) {
536 report_stray_interrupt(intr, info);
539 if (info->i_thread.td_gd == mycpu) {
540 if (info->i_running == 0) {
542 if (info->i_state != ISTATE_LIVELOCKED)
543 lwkt_schedule(&info->i_thread); /* MIGHT PREEMPT */
546 lwkt_send_ipiq(info->i_thread.td_gd,
547 sched_ithd_remote, (void *)(intptr_t)intr);
550 if (info->i_running == 0) {
552 if (info->i_state != ISTATE_LIVELOCKED)
553 lwkt_schedule(&info->i_thread); /* MIGHT PREEMPT */
558 report_stray_interrupt(intr, info);
563 report_stray_interrupt(int intr, struct intr_info *info)
565 ++info->i_straycount;
566 if (info->i_straycount < 10) {
567 if (info->i_errorticks == ticks)
569 info->i_errorticks = ticks;
570 kprintf("sched_ithd: stray interrupt %d on cpu %d\n",
572 } else if (info->i_straycount == 10) {
573 kprintf("sched_ithd: %ld stray interrupts %d on cpu %d - "
574 "there will be no further reports\n",
575 info->i_straycount, intr, mycpuid);
580 * This is run from a periodic SYSTIMER (and thus must be MP safe, the BGL
581 * might not be held).
584 ithread_livelock_wakeup(systimer_t st, int in_ipi __unused,
585 struct intrframe *frame __unused)
587 struct intr_info *info;
589 info = &intr_info_ary[(int)(intptr_t)st->data];
590 if (info->i_state != ISTATE_NOTHREAD)
591 lwkt_schedule(&info->i_thread);
595 * Schedule ithread within fast intr handler
597 * XXX Protect sched_ithd() call with gd_intr_nesting_level?
598 * Interrupts aren't enabled, but still...
601 ithread_fast_sched(int intr, thread_t td)
606 * We are already in critical section, exit it now to
611 crit_enter_quick(td);
617 * This function is called directly from the ICU or APIC vector code assembly
618 * to process an interrupt. The critical section and interrupt deferral
619 * checks have already been done but the function is entered WITHOUT
620 * a critical section held. The BGL may or may not be held.
622 * Must return non-zero if we do not want the vector code to re-enable
623 * the interrupt (which we don't if we have to schedule the interrupt)
625 int ithread_fast_handler(struct intrframe *frame);
628 ithread_fast_handler(struct intrframe *frame)
631 struct intr_info *info;
632 struct intrec **list;
637 TD_INVARIANTS_DECLARE;
642 intr = frame->if_vec;
646 /* We must be in critical section. */
647 KKASSERT(td->td_critcount);
649 info = &intr_info_ary[intr];
652 * If we are not processing any FAST interrupts, just schedule the thing.
654 if (info->i_fast == 0) {
656 ithread_fast_sched(intr, td);
661 * This should not normally occur since interrupts ought to be
662 * masked if the ithread has been scheduled or is running.
668 * Bump the interrupt nesting level to process any FAST interrupts.
669 * Obtain the MP lock as necessary. If the MP lock cannot be obtained,
670 * schedule the interrupt thread to deal with the issue instead.
672 * To reduce overhead, just leave the MP lock held once it has been
675 ++gd->gd_intr_nesting_level;
677 must_schedule = info->i_slow;
682 TD_INVARIANTS_GET(td);
683 list = &info->i_reclist;
685 for (rec = *list; rec; rec = nrec) {
686 /* rec may be invalid after call */
689 if (rec->intr_flags & INTR_CLOCK) {
691 if ((rec->intr_flags & INTR_MPSAFE) == 0 && got_mplock == 0) {
692 if (try_mplock() == 0) {
693 /* Couldn't get the MP lock; just schedule it. */
700 if (rec->serializer) {
701 must_schedule += lwkt_serialize_handler_try(
702 rec->serializer, rec->handler,
703 rec->argument, frame);
705 rec->handler(rec->argument, frame);
707 TD_INVARIANTS_TEST(td, rec->name);
714 --gd->gd_intr_nesting_level;
721 * If we had a problem, or mixed fast and slow interrupt handlers are
722 * registered, schedule the ithread to catch the missed records (it
723 * will just re-run all of them). A return value of 0 indicates that
724 * all handlers have been run and the interrupt can be re-enabled, and
725 * a non-zero return indicates that the interrupt thread controls
728 if (must_schedule > 0)
729 ithread_fast_sched(intr, td);
730 else if (must_schedule == 0)
732 return(must_schedule);
736 * Interrupt threads run this as their main loop.
738 * The handler begins execution outside a critical section and no MP lock.
740 * The i_running state starts at 0. When an interrupt occurs, the hardware
741 * interrupt is disabled and sched_ithd() The HW interrupt remains disabled
742 * until all routines have run. We then call ithread_done() to reenable
743 * the HW interrupt and deschedule us until the next interrupt.
745 * We are responsible for atomically checking i_running and ithread_done()
746 * is responsible for atomically checking for platform-specific delayed
747 * interrupts. i_running for our irq is only set in the context of our cpu,
748 * so a critical section is a sufficient interlock.
750 #define LIVELOCK_TIMEFRAME(freq) ((freq) >> 2) /* 1/4 second */
753 ithread_handler(void *arg)
755 struct intr_info *info;
760 struct intrec **list;
763 struct systimer ill_timer; /* enforced freq. timer */
764 u_int ill_count; /* interrupt livelock counter */
765 TD_INVARIANTS_DECLARE;
768 intr = (int)(intptr_t)arg;
769 info = &intr_info_ary[intr];
770 list = &info->i_reclist;
773 * The loop must be entered with one critical section held. The thread
774 * does not hold the mplock on startup.
777 lseconds = gd->gd_time_seconds;
783 * The chain is only considered MPSAFE if all its interrupt handlers
784 * are MPSAFE. However, if intr_mpsafe has been turned off we
785 * always operate with the BGL.
788 if (info->i_mplock_required != mpheld) {
789 if (info->i_mplock_required) {
790 KKASSERT(mpheld == 0);
794 KKASSERT(mpheld != 0);
801 TD_INVARIANTS_GET(gd->gd_curthread);
804 * If an interrupt is pending, clear i_running and execute the
805 * handlers. Note that certain types of interrupts can re-trigger
806 * and set i_running again.
808 * Each handler is run in a critical section. Note that we run both
809 * FAST and SLOW designated service routines.
811 if (info->i_running) {
816 report_stray_interrupt(intr, info);
818 for (rec = *list; rec; rec = nrec) {
819 /* rec may be invalid after call */
821 if (rec->serializer) {
822 lwkt_serialize_handler_call(rec->serializer, rec->handler,
823 rec->argument, NULL);
825 rec->handler(rec->argument, NULL);
827 TD_INVARIANTS_TEST(gd->gd_curthread, rec->name);
832 * This is our interrupt hook to add rate randomness to the random
835 if (info->i_random.sc_enabled > 0)
836 add_interrupt_randomness(intr);
839 * Unmask the interrupt to allow it to trigger again. This only
840 * applies to certain types of interrupts (typ level interrupts).
841 * This can result in the interrupt retriggering, but the retrigger
842 * will not be processed until we cycle our critical section.
844 * Only unmask interrupts while handlers are installed. It is
845 * possible to hit a situation where no handlers are installed
846 * due to a device driver livelocking and then tearing down its
847 * interrupt on close (the parallel bus being a good example).
849 if (intr < FIRST_SOFTINT && *list)
850 machintr_intren(intr);
853 * Do a quick exit/enter to catch any higher-priority interrupt
854 * sources, such as the statclock, so thread time accounting
855 * will still work. This may also cause an interrupt to re-trigger.
861 * LIVELOCK STATE MACHINE
863 switch(info->i_state) {
866 * Reset the count each second.
868 if (lseconds != gd->gd_time_seconds) {
869 lseconds = gd->gd_time_seconds;
874 * If we did not exceed the frequency limit, we are done.
875 * If the interrupt has not retriggered we deschedule ourselves.
877 if (ill_count <= livelock_limit) {
878 if (info->i_running == 0) {
879 lwkt_deschedule_self(gd->gd_curthread);
886 * Otherwise we are livelocked. Set up a periodic systimer
887 * to wake the thread up at the limit frequency.
889 kprintf("intr %d at %d/%d hz, livelocked limit engaged!\n",
890 intr, ill_count, livelock_limit);
891 info->i_state = ISTATE_LIVELOCKED;
892 if ((use_limit = livelock_limit) < 100)
894 else if (use_limit > 500000)
896 systimer_init_periodic_nq(&ill_timer, ithread_livelock_wakeup,
897 (void *)(intptr_t)intr, use_limit);
899 case ISTATE_LIVELOCKED:
901 * Wait for our periodic timer to go off. Since the interrupt
902 * has re-armed it can still set i_running, but it will not
903 * reschedule us while we are in a livelocked state.
905 lwkt_deschedule_self(gd->gd_curthread);
909 * Check once a second to see if the livelock condition no
912 if (lseconds != gd->gd_time_seconds) {
913 lseconds = gd->gd_time_seconds;
914 if (ill_count < livelock_lowater) {
915 info->i_state = ISTATE_NORMAL;
916 systimer_del(&ill_timer);
917 kprintf("intr %d at %d/%d hz, livelock removed\n",
918 intr, ill_count, livelock_lowater);
919 } else if (livelock_debug == intr ||
920 (bootverbose && cold)) {
921 kprintf("intr %d at %d/%d hz, in livelock\n",
922 intr, ill_count, livelock_lowater);
933 * Emergency interrupt polling thread. The thread begins execution
934 * outside a critical section with the BGL held.
936 * If emergency interrupt polling is enabled, this thread will
937 * execute all system interrupts not marked INTR_NOPOLL at the
938 * specified polling frequency.
940 * WARNING! This thread runs *ALL* interrupt service routines that
941 * are not marked INTR_NOPOLL, which basically means everything except
942 * the 8254 clock interrupt and the ATA interrupt. It has very high
943 * overhead and should only be used in situations where the machine
944 * cannot otherwise be made to work. Due to the severe performance
945 * degredation, it should not be enabled on production machines.
948 ithread_emergency(void *arg __unused)
950 globaldata_t gd = mycpu;
951 struct intr_info *info;
954 TD_INVARIANTS_DECLARE;
958 TD_INVARIANTS_GET(gd->gd_curthread);
961 for (intr = 0; intr < max_installed_hard_intr; ++intr) {
962 info = &intr_info_ary[intr];
963 for (rec = info->i_reclist; rec; rec = nrec) {
964 /* rec may be invalid after call */
966 if ((rec->intr_flags & INTR_NOPOLL) == 0) {
967 if (rec->serializer) {
968 lwkt_serialize_handler_try(rec->serializer,
969 rec->handler, rec->argument, NULL);
971 rec->handler(rec->argument, NULL);
973 TD_INVARIANTS_TEST(gd->gd_curthread, rec->name);
977 lwkt_deschedule_self(gd->gd_curthread);
984 * Systimer callback - schedule the emergency interrupt poll thread
985 * if emergency polling is enabled.
989 emergency_intr_timer_callback(systimer_t info, int in_ipi __unused,
990 struct intrframe *frame __unused)
992 if (emergency_intr_enable)
993 lwkt_schedule(info->data);
997 ithread_cpuid(int intr)
999 const struct intr_info *info;
1001 KKASSERT(intr >= 0 && intr < MAX_INTS);
1002 info = &intr_info_ary[intr];
1004 if (info->i_state == ISTATE_NOTHREAD)
1006 return info->i_thread.td_gd->gd_cpuid;
1010 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
1011 * The data for this machine dependent, and the declarations are in machine
1012 * dependent code. The layout of intrnames and intrcnt however is machine
1015 * We do not know the length of intrcnt and intrnames at compile time, so
1016 * calculate things at run time.
1020 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
1022 struct intr_info *info;
1029 for (intr = 0; error == 0 && intr < MAX_INTS; ++intr) {
1030 info = &intr_info_ary[intr];
1034 for (rec = info->i_reclist; rec; rec = rec->next) {
1035 ksnprintf(buf + len, sizeof(buf) - len, "%s%s",
1036 (len ? "/" : ""), rec->name);
1037 len += strlen(buf + len);
1040 ksnprintf(buf, sizeof(buf), "irq%d", intr);
1043 error = SYSCTL_OUT(req, buf, len + 1);
1049 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
1050 NULL, 0, sysctl_intrnames, "", "Interrupt Names");
1053 sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
1055 struct intr_info *info;
1059 for (intr = 0; intr < max_installed_hard_intr; ++intr) {
1060 info = &intr_info_ary[intr];
1062 error = SYSCTL_OUT(req, &info->i_count, sizeof(info->i_count));
1066 for (intr = FIRST_SOFTINT; intr < max_installed_soft_intr; ++intr) {
1067 info = &intr_info_ary[intr];
1069 error = SYSCTL_OUT(req, &info->i_count, sizeof(info->i_count));
1077 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
1078 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
1081 sysctl_intrcnt_all(SYSCTL_HANDLER_ARGS)
1083 struct intr_info *info;
1087 for (intr = 0; intr < MAX_INTS; ++intr) {
1088 info = &intr_info_ary[intr];
1090 error = SYSCTL_OUT(req, &info->i_count, sizeof(info->i_count));
1098 SYSCTL_PROC(_hw, OID_AUTO, intrcnt_all, CTLTYPE_OPAQUE | CTLFLAG_RD,
1099 NULL, 0, sysctl_intrcnt_all, "", "Interrupt Counts");
1102 int_moveto_destcpu(int *orig_cpuid0, int *cpuid0, int intr)
1104 int orig_cpuid = mycpuid, cpuid;
1108 ksnprintf(envpath, sizeof(envpath), "hw.irq.%d.dest", intr);
1109 kgetenv_int(envpath, &cpuid);
1113 if (cpuid != orig_cpuid)
1114 lwkt_migratecpu(cpuid);
1116 *orig_cpuid0 = orig_cpuid;
1121 int_moveto_origcpu(int orig_cpuid, int cpuid)
1123 if (cpuid != orig_cpuid)
1124 lwkt_migratecpu(orig_cpuid);