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/thread2.h>
39 #include <sys/random.h>
40 #include <sys/serialize.h>
41 #include <sys/interrupt.h>
43 #include <sys/machintr.h>
45 #include <machine/frame.h>
47 #include <sys/interrupt.h>
51 typedef struct intrec
{
53 struct intr_info
*info
;
59 struct lwkt_serialize
*serializer
;
64 struct thread i_thread
;
65 struct random_softc i_random
;
67 long i_count
; /* interrupts dispatched */
68 int i_mplock_required
;
73 unsigned long i_straycount
;
74 } intr_info_ary
[MAX_INTS
];
76 int max_installed_hard_intr
;
77 int max_installed_soft_intr
;
79 #define EMERGENCY_INTR_POLLING_FREQ_MAX 20000
81 static int sysctl_emergency_freq(SYSCTL_HANDLER_ARGS
);
82 static int sysctl_emergency_enable(SYSCTL_HANDLER_ARGS
);
83 static void emergency_intr_timer_callback(systimer_t
, struct intrframe
*);
84 static void ithread_handler(void *arg
);
85 static void ithread_emergency(void *arg
);
86 static void report_stray_interrupt(int intr
, struct intr_info
*info
);
88 int intr_info_size
= sizeof(intr_info_ary
) / sizeof(intr_info_ary
[0]);
90 static struct systimer emergency_intr_timer
;
91 static struct thread emergency_intr_thread
;
93 #define ISTATE_NOTHREAD 0
94 #define ISTATE_NORMAL 1
95 #define ISTATE_LIVELOCKED 2
98 static int intr_mpsafe
= 1;
99 TUNABLE_INT("kern.intr_mpsafe", &intr_mpsafe
);
100 SYSCTL_INT(_kern
, OID_AUTO
, intr_mpsafe
,
101 CTLFLAG_RW
, &intr_mpsafe
, 0, "Run INTR_MPSAFE handlers without the BGL");
103 static int livelock_limit
= 40000;
104 static int livelock_lowater
= 20000;
105 static int livelock_debug
= -1;
106 SYSCTL_INT(_kern
, OID_AUTO
, livelock_limit
,
107 CTLFLAG_RW
, &livelock_limit
, 0, "Livelock interrupt rate limit");
108 SYSCTL_INT(_kern
, OID_AUTO
, livelock_lowater
,
109 CTLFLAG_RW
, &livelock_lowater
, 0, "Livelock low-water mark restore");
110 SYSCTL_INT(_kern
, OID_AUTO
, livelock_debug
,
111 CTLFLAG_RW
, &livelock_debug
, 0, "Livelock debug intr#");
113 static int emergency_intr_enable
= 0; /* emergency interrupt polling */
114 TUNABLE_INT("kern.emergency_intr_enable", &emergency_intr_enable
);
115 SYSCTL_PROC(_kern
, OID_AUTO
, emergency_intr_enable
, CTLTYPE_INT
| CTLFLAG_RW
,
116 0, 0, sysctl_emergency_enable
, "I", "Emergency Interrupt Poll Enable");
118 static int emergency_intr_freq
= 10; /* emergency polling frequency */
119 TUNABLE_INT("kern.emergency_intr_freq", &emergency_intr_freq
);
120 SYSCTL_PROC(_kern
, OID_AUTO
, emergency_intr_freq
, CTLTYPE_INT
| CTLFLAG_RW
,
121 0, 0, sysctl_emergency_freq
, "I", "Emergency Interrupt Poll Frequency");
124 * Sysctl support routines
127 sysctl_emergency_enable(SYSCTL_HANDLER_ARGS
)
131 enabled
= emergency_intr_enable
;
132 error
= sysctl_handle_int(oidp
, &enabled
, 0, req
);
133 if (error
|| req
->newptr
== NULL
)
135 emergency_intr_enable
= enabled
;
136 if (emergency_intr_enable
) {
137 systimer_adjust_periodic(&emergency_intr_timer
,
138 emergency_intr_freq
);
140 systimer_adjust_periodic(&emergency_intr_timer
, 1);
146 sysctl_emergency_freq(SYSCTL_HANDLER_ARGS
)
150 phz
= emergency_intr_freq
;
151 error
= sysctl_handle_int(oidp
, &phz
, 0, req
);
152 if (error
|| req
->newptr
== NULL
)
156 else if (phz
> EMERGENCY_INTR_POLLING_FREQ_MAX
)
157 phz
= EMERGENCY_INTR_POLLING_FREQ_MAX
;
159 emergency_intr_freq
= phz
;
160 if (emergency_intr_enable
) {
161 systimer_adjust_periodic(&emergency_intr_timer
,
162 emergency_intr_freq
);
164 systimer_adjust_periodic(&emergency_intr_timer
, 1);
170 * Register an SWI or INTerrupt handler.
173 register_swi(int intr
, inthand2_t
*handler
, void *arg
, const char *name
,
174 struct lwkt_serialize
*serializer
)
176 if (intr
< FIRST_SOFTINT
|| intr
>= MAX_INTS
)
177 panic("register_swi: bad intr %d", intr
);
178 return(register_int(intr
, handler
, arg
, name
, serializer
, 0));
182 register_int(int intr
, inthand2_t
*handler
, void *arg
, const char *name
,
183 struct lwkt_serialize
*serializer
, int intr_flags
)
185 struct intr_info
*info
;
186 struct intrec
**list
;
188 int orig_cpuid
= mycpuid
, cpuid
;
191 if (intr
< 0 || intr
>= MAX_INTS
)
192 panic("register_int: bad intr %d", intr
);
195 info
= &intr_info_ary
[intr
];
198 * Construct an interrupt handler record
200 rec
= kmalloc(sizeof(struct intrec
), M_DEVBUF
, M_INTWAIT
);
201 rec
->name
= kmalloc(strlen(name
) + 1, M_DEVBUF
, M_INTWAIT
);
202 strcpy(rec
->name
, name
);
205 rec
->handler
= handler
;
208 rec
->intr_flags
= intr_flags
;
210 rec
->serializer
= serializer
;
213 * Create an emergency polling thread and set up a systimer to wake
216 if (emergency_intr_thread
.td_kstack
== NULL
) {
217 lwkt_create(ithread_emergency
, NULL
, NULL
,
218 &emergency_intr_thread
, TDF_STOPREQ
|TDF_INTTHREAD
, -1,
220 systimer_init_periodic_nq(&emergency_intr_timer
,
221 emergency_intr_timer_callback
, &emergency_intr_thread
,
222 (emergency_intr_enable
? emergency_intr_freq
: 1));
226 ksnprintf(envpath
, sizeof(envpath
), "hw.irq.%d.dest", intr
);
227 kgetenv_int(envpath
, &cpuid
);
231 if (cpuid
!= orig_cpuid
)
232 lwkt_migratecpu(cpuid
);
235 * Create an interrupt thread if necessary, leave it in an unscheduled
238 if (info
->i_state
== ISTATE_NOTHREAD
) {
239 info
->i_state
= ISTATE_NORMAL
;
240 lwkt_create((void *)ithread_handler
, (void *)(intptr_t)intr
, NULL
,
241 &info
->i_thread
, TDF_STOPREQ
|TDF_INTTHREAD
|TDF_MPSAFE
, -1,
243 if (intr
>= FIRST_SOFTINT
)
244 lwkt_setpri(&info
->i_thread
, TDPRI_SOFT_NORM
);
246 lwkt_setpri(&info
->i_thread
, TDPRI_INT_MED
);
247 info
->i_thread
.td_preemptable
= lwkt_preempt
;
250 list
= &info
->i_reclist
;
253 * Keep track of how many fast and slow interrupts we have.
254 * Set i_mplock_required if any handler in the chain requires
255 * the MP lock to operate.
257 if ((intr_flags
& INTR_MPSAFE
) == 0)
258 info
->i_mplock_required
= 1;
259 if (intr_flags
& INTR_FAST
)
265 * Enable random number generation keying off of this interrupt.
267 if ((intr_flags
& INTR_NOENTROPY
) == 0 && info
->i_random
.sc_enabled
== 0) {
268 info
->i_random
.sc_enabled
= 1;
269 info
->i_random
.sc_intr
= intr
;
273 * Add the record to the interrupt list.
276 while (*list
!= NULL
)
277 list
= &(*list
)->next
;
282 * Update max_installed_hard_intr to make the emergency intr poll
283 * a bit more efficient.
285 if (intr
< FIRST_SOFTINT
) {
286 if (max_installed_hard_intr
<= intr
)
287 max_installed_hard_intr
= intr
+ 1;
289 if (max_installed_soft_intr
<= intr
)
290 max_installed_soft_intr
= intr
+ 1;
294 * Setup the machine level interrupt vector
296 * XXX temporary workaround for some ACPI brokedness. ACPI installs
297 * its interrupt too early, before the IOAPICs have been configured,
298 * which means the IOAPIC is not enabled by the registration of the
299 * ACPI interrupt. Anything else sharing that IRQ will wind up not
300 * being enabled. Temporarily work around the problem by always
301 * installing and enabling on every new interrupt handler, even
302 * if one has already been setup on that irq.
304 if (intr
< FIRST_SOFTINT
/* && info->i_slow + info->i_fast == 1*/) {
305 if (machintr_vector_setup(intr
, intr_flags
))
306 kprintf("machintr_vector_setup: failed on irq %d\n", intr
);
309 if (cpuid
!= orig_cpuid
)
310 lwkt_migratecpu(orig_cpuid
);
316 unregister_swi(void *id
)
322 unregister_int(void *id
)
324 struct intr_info
*info
;
325 struct intrec
**list
;
329 intr
= ((intrec_t
)id
)->intr
;
331 if (intr
< 0 || intr
>= MAX_INTS
)
332 panic("register_int: bad intr %d", intr
);
334 info
= &intr_info_ary
[intr
];
337 * Remove the interrupt descriptor, adjust the descriptor count,
338 * and teardown the machine level vector if this was the last interrupt.
341 list
= &info
->i_reclist
;
342 while ((rec
= *list
) != NULL
) {
351 if (rec
->intr_flags
& INTR_FAST
)
355 if (intr
< FIRST_SOFTINT
&& info
->i_fast
+ info
->i_slow
== 0)
356 machintr_vector_teardown(intr
);
359 * Clear i_mplock_required if no handlers in the chain require the
362 for (rec0
= info
->i_reclist
; rec0
; rec0
= rec0
->next
) {
363 if ((rec0
->intr_flags
& INTR_MPSAFE
) == 0)
367 info
->i_mplock_required
= 0;
376 kfree(rec
->name
, M_DEVBUF
);
377 kfree(rec
, M_DEVBUF
);
379 kprintf("warning: unregister_int: int %d handler for %s not found\n",
380 intr
, ((intrec_t
)id
)->name
);
385 get_registered_name(int intr
)
389 if (intr
< 0 || intr
>= MAX_INTS
)
390 panic("register_int: bad intr %d", intr
);
392 if ((rec
= intr_info_ary
[intr
].i_reclist
) == NULL
)
401 count_registered_ints(int intr
)
403 struct intr_info
*info
;
405 if (intr
< 0 || intr
>= MAX_INTS
)
406 panic("register_int: bad intr %d", intr
);
407 info
= &intr_info_ary
[intr
];
408 return(info
->i_fast
+ info
->i_slow
);
412 get_interrupt_counter(int intr
)
414 struct intr_info
*info
;
416 if (intr
< 0 || intr
>= MAX_INTS
)
417 panic("register_int: bad intr %d", intr
);
418 info
= &intr_info_ary
[intr
];
419 return(info
->i_count
);
424 swi_setpriority(int intr
, int pri
)
426 struct intr_info
*info
;
428 if (intr
< FIRST_SOFTINT
|| intr
>= MAX_INTS
)
429 panic("register_swi: bad intr %d", intr
);
430 info
= &intr_info_ary
[intr
];
431 if (info
->i_state
!= ISTATE_NOTHREAD
)
432 lwkt_setpri(&info
->i_thread
, pri
);
436 register_randintr(int intr
)
438 struct intr_info
*info
;
440 if (intr
< 0 || intr
>= MAX_INTS
)
441 panic("register_randintr: bad intr %d", intr
);
442 info
= &intr_info_ary
[intr
];
443 info
->i_random
.sc_intr
= intr
;
444 info
->i_random
.sc_enabled
= 1;
448 unregister_randintr(int intr
)
450 struct intr_info
*info
;
452 if (intr
< 0 || intr
>= MAX_INTS
)
453 panic("register_swi: bad intr %d", intr
);
454 info
= &intr_info_ary
[intr
];
455 info
->i_random
.sc_enabled
= -1;
459 next_registered_randintr(int intr
)
461 struct intr_info
*info
;
463 if (intr
< 0 || intr
>= MAX_INTS
)
464 panic("register_swi: bad intr %d", intr
);
465 while (intr
< MAX_INTS
) {
466 info
= &intr_info_ary
[intr
];
467 if (info
->i_random
.sc_enabled
> 0)
475 * Dispatch an interrupt. If there's nothing to do we have a stray
476 * interrupt and can just return, leaving the interrupt masked.
478 * We need to schedule the interrupt and set its i_running bit. If
479 * we are not on the interrupt thread's cpu we have to send a message
480 * to the correct cpu that will issue the desired action (interlocking
481 * with the interrupt thread's critical section). We do NOT attempt to
482 * reschedule interrupts whos i_running bit is already set because
483 * this would prematurely wakeup a livelock-limited interrupt thread.
485 * i_running is only tested/set on the same cpu as the interrupt thread.
487 * We are NOT in a critical section, which will allow the scheduled
488 * interrupt to preempt us. The MP lock might *NOT* be held here.
493 sched_ithd_remote(void *arg
)
495 sched_ithd((int)arg
);
503 struct intr_info
*info
;
505 info
= &intr_info_ary
[intr
];
508 if (info
->i_state
!= ISTATE_NOTHREAD
) {
509 if (info
->i_reclist
== NULL
) {
510 report_stray_interrupt(intr
, info
);
513 if (info
->i_thread
.td_gd
== mycpu
) {
514 if (info
->i_running
== 0) {
516 if (info
->i_state
!= ISTATE_LIVELOCKED
)
517 lwkt_schedule(&info
->i_thread
); /* MIGHT PREEMPT */
520 lwkt_send_ipiq(info
->i_thread
.td_gd
,
521 sched_ithd_remote
, (void *)intr
);
524 if (info
->i_running
== 0) {
526 if (info
->i_state
!= ISTATE_LIVELOCKED
)
527 lwkt_schedule(&info
->i_thread
); /* MIGHT PREEMPT */
532 report_stray_interrupt(intr
, info
);
537 report_stray_interrupt(int intr
, struct intr_info
*info
)
539 ++info
->i_straycount
;
540 if (info
->i_straycount
< 10) {
541 if (info
->i_errorticks
== ticks
)
543 info
->i_errorticks
= ticks
;
544 kprintf("sched_ithd: stray interrupt %d on cpu %d\n",
546 } else if (info
->i_straycount
== 10) {
547 kprintf("sched_ithd: %ld stray interrupts %d on cpu %d - "
548 "there will be no further reports\n",
549 info
->i_straycount
, intr
, mycpuid
);
554 * This is run from a periodic SYSTIMER (and thus must be MP safe, the BGL
555 * might not be held).
558 ithread_livelock_wakeup(systimer_t st
)
560 struct intr_info
*info
;
562 info
= &intr_info_ary
[(int)(intptr_t)st
->data
];
563 if (info
->i_state
!= ISTATE_NOTHREAD
)
564 lwkt_schedule(&info
->i_thread
);
568 * This function is called directly from the ICU or APIC vector code assembly
569 * to process an interrupt. The critical section and interrupt deferral
570 * checks have already been done but the function is entered WITHOUT
571 * a critical section held. The BGL may or may not be held.
573 * Must return non-zero if we do not want the vector code to re-enable
574 * the interrupt (which we don't if we have to schedule the interrupt)
576 int ithread_fast_handler(struct intrframe
*frame
);
579 ithread_fast_handler(struct intrframe
*frame
)
582 struct intr_info
*info
;
583 struct intrec
**list
;
588 intrec_t rec
, next_rec
;
591 intr
= frame
->if_vec
;
594 info
= &intr_info_ary
[intr
];
597 * If we are not processing any FAST interrupts, just schedule the thing.
598 * (since we aren't in a critical section, this can result in a
601 * XXX Protect sched_ithd() call with gd_intr_nesting_level? Interrupts
602 * aren't enabled, but still...
604 if (info
->i_fast
== 0) {
611 * This should not normally occur since interrupts ought to be
612 * masked if the ithread has been scheduled or is running.
618 * Bump the interrupt nesting level to process any FAST interrupts.
619 * Obtain the MP lock as necessary. If the MP lock cannot be obtained,
620 * schedule the interrupt thread to deal with the issue instead.
622 * To reduce overhead, just leave the MP lock held once it has been
626 ++gd
->gd_intr_nesting_level
;
628 must_schedule
= info
->i_slow
;
633 list
= &info
->i_reclist
;
634 for (rec
= *list
; rec
; rec
= next_rec
) {
635 next_rec
= rec
->next
; /* rec may be invalid after call */
637 if (rec
->intr_flags
& INTR_FAST
) {
639 if ((rec
->intr_flags
& INTR_MPSAFE
) == 0 && got_mplock
== 0) {
640 if (try_mplock() == 0) {
644 * If we couldn't get the MP lock try to forward it
645 * to the cpu holding the MP lock, setting must_schedule
646 * to -1 so we do not schedule and also do not unmask
647 * the interrupt. Otherwise just schedule it.
649 owner
= owner_mplock();
650 if (owner
>= 0 && owner
!= gd
->gd_cpuid
) {
651 lwkt_send_ipiq_bycpu(owner
, forward_fastint_remote
,
654 ++gd
->gd_cnt
.v_forwarded_ints
;
663 if (rec
->serializer
) {
664 must_schedule
+= lwkt_serialize_handler_try(
665 rec
->serializer
, rec
->handler
,
666 rec
->argument
, frame
);
668 rec
->handler(rec
->argument
, frame
);
676 --gd
->gd_intr_nesting_level
;
684 * If we had a problem, schedule the thread to catch the missed
685 * records (it will just re-run all of them). A return value of 0
686 * indicates that all handlers have been run and the interrupt can
687 * be re-enabled, and a non-zero return indicates that the interrupt
688 * thread controls re-enablement.
690 if (must_schedule
> 0)
692 else if (must_schedule
== 0)
694 return(must_schedule
);
700 /* could not get the MP lock, forward the interrupt */ \
701 movl mp_lock
, %eax
; /* check race */ \
702 cmpl $MP_FREE_LOCK
,%eax
; \
704 incl
PCPU(cnt
)+V_FORWARDED_INTS
; \
706 movl $irq_num
,8(%esp
) ; \
707 movl $forward_fastint_remote
,4(%esp
) ; \
709 call lwkt_send_ipiq_bycpu
; \
717 * Interrupt threads run this as their main loop.
719 * The handler begins execution outside a critical section and with the BGL
722 * The i_running state starts at 0. When an interrupt occurs, the hardware
723 * interrupt is disabled and sched_ithd() The HW interrupt remains disabled
724 * until all routines have run. We then call ithread_done() to reenable
725 * the HW interrupt and deschedule us until the next interrupt.
727 * We are responsible for atomically checking i_running and ithread_done()
728 * is responsible for atomically checking for platform-specific delayed
729 * interrupts. i_running for our irq is only set in the context of our cpu,
730 * so a critical section is a sufficient interlock.
732 #define LIVELOCK_TIMEFRAME(freq) ((freq) >> 2) /* 1/4 second */
735 ithread_handler(void *arg
)
737 struct intr_info
*info
;
742 struct intrec
**list
;
745 struct systimer ill_timer
; /* enforced freq. timer */
746 u_int ill_count
; /* interrupt livelock counter */
749 intr
= (int)(intptr_t)arg
;
750 info
= &intr_info_ary
[intr
];
751 list
= &info
->i_reclist
;
753 lseconds
= gd
->gd_time_seconds
;
756 * The loop must be entered with one critical section held. The thread
757 * is created with TDF_MPSAFE so the MP lock is not held on start.
764 * The chain is only considered MPSAFE if all its interrupt handlers
765 * are MPSAFE. However, if intr_mpsafe has been turned off we
766 * always operate with the BGL.
769 if (intr_mpsafe
== 0) {
774 } else if (info
->i_mplock_required
!= mpheld
) {
775 if (info
->i_mplock_required
) {
776 KKASSERT(mpheld
== 0);
780 KKASSERT(mpheld
!= 0);
788 * If an interrupt is pending, clear i_running and execute the
789 * handlers. Note that certain types of interrupts can re-trigger
790 * and set i_running again.
792 * Each handler is run in a critical section. Note that we run both
793 * FAST and SLOW designated service routines.
795 if (info
->i_running
) {
800 report_stray_interrupt(intr
, info
);
802 for (rec
= *list
; rec
; rec
= nrec
) {
804 if (rec
->serializer
) {
805 lwkt_serialize_handler_call(rec
->serializer
, rec
->handler
,
806 rec
->argument
, NULL
);
808 rec
->handler(rec
->argument
, NULL
);
814 * This is our interrupt hook to add rate randomness to the random
817 if (info
->i_random
.sc_enabled
> 0)
818 add_interrupt_randomness(intr
);
821 * Unmask the interrupt to allow it to trigger again. This only
822 * applies to certain types of interrupts (typ level interrupts).
823 * This can result in the interrupt retriggering, but the retrigger
824 * will not be processed until we cycle our critical section.
826 * Only unmask interrupts while handlers are installed. It is
827 * possible to hit a situation where no handlers are installed
828 * due to a device driver livelocking and then tearing down its
829 * interrupt on close (the parallel bus being a good example).
832 machintr_intren(intr
);
835 * Do a quick exit/enter to catch any higher-priority interrupt
836 * sources, such as the statclock, so thread time accounting
837 * will still work. This may also cause an interrupt to re-trigger.
843 * LIVELOCK STATE MACHINE
845 switch(info
->i_state
) {
848 * Reset the count each second.
850 if (lseconds
!= gd
->gd_time_seconds
) {
851 lseconds
= gd
->gd_time_seconds
;
856 * If we did not exceed the frequency limit, we are done.
857 * If the interrupt has not retriggered we deschedule ourselves.
859 if (ill_count
<= livelock_limit
) {
860 if (info
->i_running
== 0) {
861 lwkt_deschedule_self(gd
->gd_curthread
);
868 * Otherwise we are livelocked. Set up a periodic systimer
869 * to wake the thread up at the limit frequency.
871 kprintf("intr %d at %d/%d hz, livelocked limit engaged!\n",
872 intr
, ill_count
, livelock_limit
);
873 info
->i_state
= ISTATE_LIVELOCKED
;
874 if ((use_limit
= livelock_limit
) < 100)
876 else if (use_limit
> 500000)
878 systimer_init_periodic_nq(&ill_timer
, ithread_livelock_wakeup
,
879 (void *)(intptr_t)intr
, use_limit
);
881 case ISTATE_LIVELOCKED
:
883 * Wait for our periodic timer to go off. Since the interrupt
884 * has re-armed it can still set i_running, but it will not
885 * reschedule us while we are in a livelocked state.
887 lwkt_deschedule_self(gd
->gd_curthread
);
891 * Check once a second to see if the livelock condition no
894 if (lseconds
!= gd
->gd_time_seconds
) {
895 lseconds
= gd
->gd_time_seconds
;
896 if (ill_count
< livelock_lowater
) {
897 info
->i_state
= ISTATE_NORMAL
;
898 systimer_del(&ill_timer
);
899 kprintf("intr %d at %d/%d hz, livelock removed\n",
900 intr
, ill_count
, livelock_lowater
);
901 } else if (livelock_debug
== intr
||
902 (bootverbose
&& cold
)) {
903 kprintf("intr %d at %d/%d hz, in livelock\n",
904 intr
, ill_count
, livelock_lowater
);
915 * Emergency interrupt polling thread. The thread begins execution
916 * outside a critical section with the BGL held.
918 * If emergency interrupt polling is enabled, this thread will
919 * execute all system interrupts not marked INTR_NOPOLL at the
920 * specified polling frequency.
922 * WARNING! This thread runs *ALL* interrupt service routines that
923 * are not marked INTR_NOPOLL, which basically means everything except
924 * the 8254 clock interrupt and the ATA interrupt. It has very high
925 * overhead and should only be used in situations where the machine
926 * cannot otherwise be made to work. Due to the severe performance
927 * degredation, it should not be enabled on production machines.
930 ithread_emergency(void *arg __unused
)
932 struct intr_info
*info
;
937 for (intr
= 0; intr
< max_installed_hard_intr
; ++intr
) {
938 info
= &intr_info_ary
[intr
];
939 for (rec
= info
->i_reclist
; rec
; rec
= nrec
) {
940 if ((rec
->intr_flags
& INTR_NOPOLL
) == 0) {
941 if (rec
->serializer
) {
942 lwkt_serialize_handler_call(rec
->serializer
,
943 rec
->handler
, rec
->argument
, NULL
);
945 rec
->handler(rec
->argument
, NULL
);
951 lwkt_deschedule_self(curthread
);
957 * Systimer callback - schedule the emergency interrupt poll thread
958 * if emergency polling is enabled.
962 emergency_intr_timer_callback(systimer_t info
, struct intrframe
*frame __unused
)
964 if (emergency_intr_enable
)
965 lwkt_schedule(info
->data
);
969 ithread_cpuid(int intr
)
971 const struct intr_info
*info
;
973 KKASSERT(intr
>= 0 && intr
< MAX_INTS
);
974 info
= &intr_info_ary
[intr
];
976 if (info
->i_state
== ISTATE_NOTHREAD
)
978 return info
->i_thread
.td_gd
->gd_cpuid
;
982 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
983 * The data for this machine dependent, and the declarations are in machine
984 * dependent code. The layout of intrnames and intrcnt however is machine
987 * We do not know the length of intrcnt and intrnames at compile time, so
988 * calculate things at run time.
992 sysctl_intrnames(SYSCTL_HANDLER_ARGS
)
994 struct intr_info
*info
;
1001 for (intr
= 0; error
== 0 && intr
< MAX_INTS
; ++intr
) {
1002 info
= &intr_info_ary
[intr
];
1006 for (rec
= info
->i_reclist
; rec
; rec
= rec
->next
) {
1007 ksnprintf(buf
+ len
, sizeof(buf
) - len
, "%s%s",
1008 (len
? "/" : ""), rec
->name
);
1009 len
+= strlen(buf
+ len
);
1012 ksnprintf(buf
, sizeof(buf
), "irq%d", intr
);
1015 error
= SYSCTL_OUT(req
, buf
, len
+ 1);
1021 SYSCTL_PROC(_hw
, OID_AUTO
, intrnames
, CTLTYPE_OPAQUE
| CTLFLAG_RD
,
1022 NULL
, 0, sysctl_intrnames
, "", "Interrupt Names");
1025 sysctl_intrcnt(SYSCTL_HANDLER_ARGS
)
1027 struct intr_info
*info
;
1031 for (intr
= 0; intr
< max_installed_hard_intr
; ++intr
) {
1032 info
= &intr_info_ary
[intr
];
1034 error
= SYSCTL_OUT(req
, &info
->i_count
, sizeof(info
->i_count
));
1038 for (intr
= FIRST_SOFTINT
; intr
< max_installed_soft_intr
; ++intr
) {
1039 info
= &intr_info_ary
[intr
];
1041 error
= SYSCTL_OUT(req
, &info
->i_count
, sizeof(info
->i_count
));
1049 SYSCTL_PROC(_hw
, OID_AUTO
, intrcnt
, CTLTYPE_OPAQUE
| CTLFLAG_RD
,
1050 NULL
, 0, sysctl_intrcnt
, "", "Interrupt Counts");