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
; /* don't embed struct thread */
64 struct random_softc i_random
;
65 long i_count
; /* interrupts dispatched */
67 short i_mplock_required
;
73 unsigned long i_straycount
;
78 struct intr_info_block
{
79 struct intr_info ary
[MAXCPU
][MAX_INTS
];
82 static struct intr_info_block
*intr_block
;
83 static struct intr_info
*swi_info_ary
[MAX_SOFTINTS
];
85 static int max_installed_hard_intr
[MAXCPU
];
87 MALLOC_DEFINE(M_INTRMNG
, "intrmng", "interrupt management");
90 #define EMERGENCY_INTR_POLLING_FREQ_MAX 20000
93 * Assert that callers into interrupt handlers don't return with
94 * dangling tokens, spinlocks, or mp locks.
98 #define TD_INVARIANTS_DECLARE \
100 lwkt_tokref_t curstop
102 #define TD_INVARIANTS_GET(td) \
104 spincount = (td)->td_gd->gd_spinlocks; \
105 curstop = (td)->td_toks_stop; \
108 #define TD_INVARIANTS_TEST(td, name) \
110 KASSERT(spincount == (td)->td_gd->gd_spinlocks, \
111 ("spincount mismatch after interrupt handler %s", \
113 KASSERT(curstop == (td)->td_toks_stop, \
114 ("token count mismatch after interrupt handler %s", \
122 #define TD_INVARIANTS_DECLARE
123 #define TD_INVARIANTS_GET(td)
124 #define TD_INVARIANTS_TEST(td, name)
126 #endif /* ndef INVARIANTS */
128 static int sysctl_emergency_freq(SYSCTL_HANDLER_ARGS
);
129 static int sysctl_emergency_enable(SYSCTL_HANDLER_ARGS
);
130 static void emergency_intr_timer_callback(systimer_t
, int, struct intrframe
*);
131 static void ithread_handler(void *arg
);
132 static void ithread_emergency(void *arg
);
133 static void report_stray_interrupt(struct intr_info
*info
, const char *func
);
134 static void int_moveto_destcpu(int *, int);
135 static void int_moveto_origcpu(int, int);
136 static void sched_ithd_intern(struct intr_info
*info
);
138 static struct systimer emergency_intr_timer
[MAXCPU
];
139 static struct thread
*emergency_intr_thread
[MAXCPU
];
141 #define ISTATE_NOTHREAD 0
142 #define ISTATE_NORMAL 1
143 #define ISTATE_LIVELOCKED 2
145 static int livelock_limit
= 40000;
146 static int livelock_lowater
= 20000;
147 static int livelock_debug
= -1;
148 SYSCTL_INT(_kern
, OID_AUTO
, livelock_limit
,
149 CTLFLAG_RW
, &livelock_limit
, 0, "Livelock interrupt rate limit");
150 SYSCTL_INT(_kern
, OID_AUTO
, livelock_lowater
,
151 CTLFLAG_RW
, &livelock_lowater
, 0, "Livelock low-water mark restore");
152 SYSCTL_INT(_kern
, OID_AUTO
, livelock_debug
,
153 CTLFLAG_RW
, &livelock_debug
, 0, "Livelock debug intr#");
155 static int emergency_intr_enable
= 0; /* emergency interrupt polling */
156 TUNABLE_INT("kern.emergency_intr_enable", &emergency_intr_enable
);
157 SYSCTL_PROC(_kern
, OID_AUTO
, emergency_intr_enable
, CTLTYPE_INT
| CTLFLAG_RW
,
158 0, 0, sysctl_emergency_enable
, "I", "Emergency Interrupt Poll Enable");
160 static int emergency_intr_freq
= 10; /* emergency polling frequency */
161 TUNABLE_INT("kern.emergency_intr_freq", &emergency_intr_freq
);
162 SYSCTL_PROC(_kern
, OID_AUTO
, emergency_intr_freq
, CTLTYPE_INT
| CTLFLAG_RW
,
163 0, 0, sysctl_emergency_freq
, "I", "Emergency Interrupt Poll Frequency");
166 * Sysctl support routines
169 sysctl_emergency_enable(SYSCTL_HANDLER_ARGS
)
171 int error
, enabled
, cpuid
, freq
;
173 enabled
= emergency_intr_enable
;
174 error
= sysctl_handle_int(oidp
, &enabled
, 0, req
);
175 if (error
|| req
->newptr
== NULL
)
177 emergency_intr_enable
= enabled
;
178 if (emergency_intr_enable
)
179 freq
= emergency_intr_freq
;
183 for (cpuid
= 0; cpuid
< ncpus
; ++cpuid
)
184 systimer_adjust_periodic(&emergency_intr_timer
[cpuid
], freq
);
189 sysctl_emergency_freq(SYSCTL_HANDLER_ARGS
)
191 int error
, phz
, cpuid
, freq
;
193 phz
= emergency_intr_freq
;
194 error
= sysctl_handle_int(oidp
, &phz
, 0, req
);
195 if (error
|| req
->newptr
== NULL
)
199 else if (phz
> EMERGENCY_INTR_POLLING_FREQ_MAX
)
200 phz
= EMERGENCY_INTR_POLLING_FREQ_MAX
;
202 emergency_intr_freq
= phz
;
203 if (emergency_intr_enable
)
204 freq
= emergency_intr_freq
;
208 for (cpuid
= 0; cpuid
< ncpus
; ++cpuid
)
209 systimer_adjust_periodic(&emergency_intr_timer
[cpuid
], freq
);
214 * Register an SWI or INTerrupt handler.
217 register_swi(int intr
, inthand2_t
*handler
, void *arg
, const char *name
,
218 struct lwkt_serialize
*serializer
, int cpuid
)
220 if (intr
< FIRST_SOFTINT
|| intr
>= MAX_INTS
)
221 panic("register_swi: bad intr %d", intr
);
224 cpuid
= intr
% ncpus
;
225 return(register_int(intr
, handler
, arg
, name
, serializer
, 0, cpuid
));
229 register_swi_mp(int intr
, inthand2_t
*handler
, void *arg
, const char *name
,
230 struct lwkt_serialize
*serializer
, int cpuid
)
232 if (intr
< FIRST_SOFTINT
|| intr
>= MAX_INTS
)
233 panic("register_swi: bad intr %d", intr
);
236 cpuid
= intr
% ncpus
;
237 return(register_int(intr
, handler
, arg
, name
, serializer
,
238 INTR_MPSAFE
, cpuid
));
242 register_int(int intr
, inthand2_t
*handler
, void *arg
, const char *name
,
243 struct lwkt_serialize
*serializer
, int intr_flags
, int cpuid
)
245 struct intr_info
*info
;
246 struct intrec
**list
;
250 KKASSERT(cpuid
>= 0 && cpuid
< ncpus
);
252 if (intr
< 0 || intr
>= MAX_INTS
)
253 panic("register_int: bad intr %d", intr
);
256 info
= &intr_block
->ary
[cpuid
][intr
];
258 int_moveto_destcpu(&orig_cpuid
, cpuid
);
261 * This intr has been registered as exclusive one, so
264 if (info
->i_flags
& INTR_EXCL
)
268 * This intr has been registered as shared one, so it
269 * can't be used for exclusive handler.
271 list
= &info
->i_reclist
;
272 if ((intr_flags
& INTR_EXCL
) && *list
!= NULL
)
276 * Construct an interrupt handler record
278 rec
= kmalloc(sizeof(struct intrec
), M_DEVBUF
, M_INTWAIT
);
279 rec
->name
= kmalloc(strlen(name
) + 1, M_DEVBUF
, M_INTWAIT
);
280 strcpy(rec
->name
, name
);
283 rec
->handler
= handler
;
286 rec
->intr_flags
= intr_flags
;
288 rec
->serializer
= serializer
;
291 * Create an emergency polling thread and set up a systimer to wake
292 * it up. objcache isn't operational yet so use kmalloc.
294 * objcache may not be operational yet, use kmalloc().
296 if (emergency_intr_thread
[cpuid
] == NULL
) {
297 emergency_intr_thread
[cpuid
] = kmalloc(sizeof(struct thread
), M_DEVBUF
,
299 lwkt_create(ithread_emergency
, NULL
, NULL
,
300 emergency_intr_thread
[cpuid
],
301 TDF_NOSTART
| TDF_INTTHREAD
, cpuid
, "ithreadE %d",
303 systimer_init_periodic_nq(&emergency_intr_timer
[cpuid
],
304 emergency_intr_timer_callback
,
305 emergency_intr_thread
[cpuid
],
306 (emergency_intr_enable
? emergency_intr_freq
: 1));
310 * Create an interrupt thread if necessary, leave it in an unscheduled
313 if (info
->i_state
== ISTATE_NOTHREAD
) {
314 info
->i_state
= ISTATE_NORMAL
;
315 info
->i_thread
= kmalloc(sizeof(struct thread
), M_DEVBUF
,
317 lwkt_create(ithread_handler
, (void *)(intptr_t)intr
, NULL
,
318 info
->i_thread
, TDF_NOSTART
| TDF_INTTHREAD
, cpuid
,
319 "ithread%d %d", intr
, cpuid
);
320 if (intr
>= FIRST_SOFTINT
)
321 lwkt_setpri(info
->i_thread
, TDPRI_SOFT_NORM
);
323 lwkt_setpri(info
->i_thread
, TDPRI_INT_MED
);
324 info
->i_thread
->td_preemptable
= lwkt_preempt
;
328 * Keep track of how many fast and slow interrupts we have.
329 * Set i_mplock_required if any handler in the chain requires
330 * the MP lock to operate.
332 if ((intr_flags
& INTR_MPSAFE
) == 0)
333 info
->i_mplock_required
= 1;
334 if (intr_flags
& INTR_CLOCK
)
338 info
->i_flags
|= (intr_flags
& INTR_EXCL
);
341 * Enable random number generation keying off of this interrupt.
343 if ((intr_flags
& INTR_NOENTROPY
) == 0 && info
->i_random
.sc_enabled
== 0) {
344 info
->i_random
.sc_enabled
= 1;
345 info
->i_random
.sc_intr
= intr
;
349 * Add the record to the interrupt list.
352 while (*list
!= NULL
)
353 list
= &(*list
)->next
;
358 * Update max_installed_hard_intr to make the emergency intr poll
359 * a bit more efficient.
361 if (intr
< FIRST_SOFTINT
) {
362 if (max_installed_hard_intr
[cpuid
] <= intr
)
363 max_installed_hard_intr
[cpuid
] = intr
+ 1;
366 if (intr
>= FIRST_SOFTINT
)
367 swi_info_ary
[intr
- FIRST_SOFTINT
] = info
;
370 * Setup the machine level interrupt vector
372 if (intr
< FIRST_SOFTINT
&& info
->i_slow
+ info
->i_fast
== 1)
373 machintr_intr_setup(intr
, intr_flags
);
376 int_moveto_origcpu(orig_cpuid
, cpuid
);
381 unregister_swi(void *id
, int intr
, int cpuid
)
384 cpuid
= intr
% ncpus
;
386 unregister_int(id
, cpuid
);
390 unregister_int(void *id
, int cpuid
)
392 struct intr_info
*info
;
393 struct intrec
**list
;
395 int intr
, orig_cpuid
;
397 KKASSERT(cpuid
>= 0 && cpuid
< ncpus
);
399 intr
= ((intrec_t
)id
)->intr
;
401 if (intr
< 0 || intr
>= MAX_INTS
)
402 panic("register_int: bad intr %d", intr
);
404 info
= &intr_block
->ary
[cpuid
][intr
];
406 int_moveto_destcpu(&orig_cpuid
, cpuid
);
409 * Remove the interrupt descriptor, adjust the descriptor count,
410 * and teardown the machine level vector if this was the last interrupt.
413 list
= &info
->i_reclist
;
414 while ((rec
= *list
) != NULL
) {
423 if (rec
->intr_flags
& INTR_CLOCK
)
427 if (intr
< FIRST_SOFTINT
&& info
->i_fast
+ info
->i_slow
== 0)
428 machintr_intr_teardown(intr
);
431 * Clear i_mplock_required if no handlers in the chain require the
434 for (rec0
= info
->i_reclist
; rec0
; rec0
= rec0
->next
) {
435 if ((rec0
->intr_flags
& INTR_MPSAFE
) == 0)
439 info
->i_mplock_required
= 0;
442 if (info
->i_reclist
== NULL
) {
444 if (intr
>= FIRST_SOFTINT
)
445 swi_info_ary
[intr
- FIRST_SOFTINT
] = NULL
;
450 int_moveto_origcpu(orig_cpuid
, cpuid
);
456 kfree(rec
->name
, M_DEVBUF
);
457 kfree(rec
, M_DEVBUF
);
459 kprintf("warning: unregister_int: int %d handler for %s not found\n",
460 intr
, ((intrec_t
)id
)->name
);
465 get_interrupt_counter(int intr
, int cpuid
)
467 struct intr_info
*info
;
469 KKASSERT(cpuid
>= 0 && cpuid
< ncpus
);
471 if (intr
< 0 || intr
>= MAX_INTS
)
472 panic("register_int: bad intr %d", intr
);
473 info
= &intr_block
->ary
[cpuid
][intr
];
474 return(info
->i_count
);
478 register_randintr(int intr
)
480 struct intr_info
*info
;
483 if (intr
< 0 || intr
>= MAX_INTS
)
484 panic("register_randintr: bad intr %d", intr
);
486 for (cpuid
= 0; cpuid
< ncpus
; ++cpuid
) {
487 info
= &intr_block
->ary
[cpuid
][intr
];
488 info
->i_random
.sc_intr
= intr
;
489 info
->i_random
.sc_enabled
= 1;
494 unregister_randintr(int intr
)
496 struct intr_info
*info
;
499 if (intr
< 0 || intr
>= MAX_INTS
)
500 panic("register_swi: bad intr %d", intr
);
502 for (cpuid
= 0; cpuid
< ncpus
; ++cpuid
) {
503 info
= &intr_block
->ary
[cpuid
][intr
];
504 info
->i_random
.sc_enabled
= -1;
509 next_registered_randintr(int intr
)
511 struct intr_info
*info
;
513 if (intr
< 0 || intr
>= MAX_INTS
)
514 panic("register_swi: bad intr %d", intr
);
516 while (intr
< MAX_INTS
) {
519 for (cpuid
= 0; cpuid
< ncpus
; ++cpuid
) {
520 info
= &intr_block
->ary
[cpuid
][intr
];
521 if (info
->i_random
.sc_enabled
> 0)
530 * Dispatch an interrupt. If there's nothing to do we have a stray
531 * interrupt and can just return, leaving the interrupt masked.
533 * We need to schedule the interrupt and set its i_running bit. If
534 * we are not on the interrupt thread's cpu we have to send a message
535 * to the correct cpu that will issue the desired action (interlocking
536 * with the interrupt thread's critical section). We do NOT attempt to
537 * reschedule interrupts whos i_running bit is already set because
538 * this would prematurely wakeup a livelock-limited interrupt thread.
540 * i_running is only tested/set on the same cpu as the interrupt thread.
542 * We are NOT in a critical section, which will allow the scheduled
543 * interrupt to preempt us. The MP lock might *NOT* be held here.
546 sched_ithd_remote(void *arg
)
548 sched_ithd_intern(arg
);
552 sched_ithd_intern(struct intr_info
*info
)
555 if (info
->i_state
!= ISTATE_NOTHREAD
) {
556 if (info
->i_reclist
== NULL
) {
557 report_stray_interrupt(info
, "sched_ithd");
559 if (info
->i_thread
->td_gd
== mycpu
) {
560 if (info
->i_running
== 0) {
562 if (info
->i_state
!= ISTATE_LIVELOCKED
)
563 lwkt_schedule(info
->i_thread
); /* MIGHT PREEMPT */
566 lwkt_send_ipiq(info
->i_thread
->td_gd
, sched_ithd_remote
, info
);
570 report_stray_interrupt(info
, "sched_ithd");
575 sched_ithd_soft(int intr
)
577 struct intr_info
*info
;
579 KKASSERT(intr
>= FIRST_SOFTINT
&& intr
< MAX_INTS
);
581 info
= swi_info_ary
[intr
- FIRST_SOFTINT
];
583 sched_ithd_intern(info
);
585 kprintf("unregistered softint %d got scheduled on cpu%d\n",
591 sched_ithd_hard(int intr
)
593 KKASSERT(intr
>= 0 && intr
< MAX_HARDINTS
);
594 sched_ithd_intern(&intr_block
->ary
[mycpuid
][intr
]);
597 #ifdef _KERNEL_VIRTUAL
600 sched_ithd_hard_virtual(int intr
)
602 KKASSERT(intr
>= 0 && intr
< MAX_HARDINTS
);
603 sched_ithd_intern(&intr_block
->ary
[0][intr
]);
607 register_int_virtual(int intr
, inthand2_t
*handler
, void *arg
, const char *name
,
608 struct lwkt_serialize
*serializer
, int intr_flags
)
610 return register_int(intr
, handler
, arg
, name
, serializer
, intr_flags
, 0);
614 unregister_int_virtual(void *id
)
616 unregister_int(id
, 0);
619 #endif /* _KERN_VIRTUAL */
622 report_stray_interrupt(struct intr_info
*info
, const char *func
)
624 ++info
->i_straycount
;
625 if (info
->i_straycount
< 10) {
626 if (info
->i_errorticks
== ticks
)
628 info
->i_errorticks
= ticks
;
629 kprintf("%s: stray interrupt %d on cpu%d\n",
630 func
, info
->i_intr
, mycpuid
);
631 } else if (info
->i_straycount
== 10) {
632 kprintf("%s: %ld stray interrupts %d on cpu%d - "
633 "there will be no further reports\n", func
,
634 info
->i_straycount
, info
->i_intr
, mycpuid
);
639 * This is run from a periodic SYSTIMER (and thus must be MP safe, the BGL
640 * might not be held).
643 ithread_livelock_wakeup(systimer_t st
, int in_ipi __unused
,
644 struct intrframe
*frame __unused
)
646 struct intr_info
*info
;
648 info
= &intr_block
->ary
[mycpuid
][(int)(intptr_t)st
->data
];
649 if (info
->i_state
!= ISTATE_NOTHREAD
)
650 lwkt_schedule(info
->i_thread
);
654 * Schedule ithread within fast intr handler
656 * XXX Protect sched_ithd_hard() call with gd_intr_nesting_level?
657 * Interrupts aren't enabled, but still...
660 ithread_fast_sched(int intr
, thread_t td
)
665 * We are already in critical section, exit it now to
669 sched_ithd_hard(intr
);
670 crit_enter_quick(td
);
676 * This function is called directly from the ICU or APIC vector code assembly
677 * to process an interrupt. The critical section and interrupt deferral
678 * checks have already been done but the function is entered WITHOUT
679 * a critical section held. The BGL may or may not be held.
681 * Must return non-zero if we do not want the vector code to re-enable
682 * the interrupt (which we don't if we have to schedule the interrupt)
684 int ithread_fast_handler(struct intrframe
*frame
);
687 ithread_fast_handler(struct intrframe
*frame
)
690 struct intr_info
*info
;
691 struct intrec
**list
;
694 TD_INVARIANTS_DECLARE
;
699 intr
= frame
->if_vec
;
703 /* We must be in critical section. */
704 KKASSERT(td
->td_critcount
);
706 info
= &intr_block
->ary
[mycpuid
][intr
];
709 * If we are not processing any FAST interrupts, just schedule the thing.
711 if (info
->i_fast
== 0) {
713 ithread_fast_sched(intr
, td
);
718 * This should not normally occur since interrupts ought to be
719 * masked if the ithread has been scheduled or is running.
725 * Bump the interrupt nesting level to process any FAST interrupts.
726 * Obtain the MP lock as necessary. If the MP lock cannot be obtained,
727 * schedule the interrupt thread to deal with the issue instead.
729 * To reduce overhead, just leave the MP lock held once it has been
732 ++gd
->gd_intr_nesting_level
;
734 must_schedule
= info
->i_slow
;
737 TD_INVARIANTS_GET(td
);
738 list
= &info
->i_reclist
;
740 for (rec
= *list
; rec
; rec
= nrec
) {
741 /* rec may be invalid after call */
744 if (rec
->intr_flags
& INTR_CLOCK
) {
745 if ((rec
->intr_flags
& INTR_MPSAFE
) == 0 && got_mplock
== 0) {
746 if (try_mplock() == 0) {
747 /* Couldn't get the MP lock; just schedule it. */
753 if (rec
->serializer
) {
754 must_schedule
+= lwkt_serialize_handler_try(
755 rec
->serializer
, rec
->handler
,
756 rec
->argument
, frame
);
758 rec
->handler(rec
->argument
, frame
);
760 TD_INVARIANTS_TEST(td
, rec
->name
);
767 --gd
->gd_intr_nesting_level
;
772 * If we had a problem, or mixed fast and slow interrupt handlers are
773 * registered, schedule the ithread to catch the missed records (it
774 * will just re-run all of them). A return value of 0 indicates that
775 * all handlers have been run and the interrupt can be re-enabled, and
776 * a non-zero return indicates that the interrupt thread controls
779 if (must_schedule
> 0)
780 ithread_fast_sched(intr
, td
);
781 else if (must_schedule
== 0)
783 return(must_schedule
);
787 * Interrupt threads run this as their main loop.
789 * The handler begins execution outside a critical section and no MP lock.
791 * The i_running state starts at 0. When an interrupt occurs, the hardware
792 * interrupt is disabled and sched_ithd_hard(). The HW interrupt remains
793 * disabled until all routines have run. We then call machintr_intr_enable()
794 * to reenable the HW interrupt and deschedule us until the next interrupt.
796 * We are responsible for atomically checking i_running. i_running for our
797 * irq is only set in the context of our cpu, so a critical section is a
798 * sufficient interlock.
800 #define LIVELOCK_TIMEFRAME(freq) ((freq) >> 2) /* 1/4 second */
803 ithread_handler(void *arg
)
805 struct intr_info
*info
;
808 int intr
, cpuid
= mycpuid
;
810 struct intrec
**list
;
813 struct systimer ill_timer
; /* enforced freq. timer */
814 u_int ill_count
; /* interrupt livelock counter */
815 TD_INVARIANTS_DECLARE
;
818 intr
= (int)(intptr_t)arg
;
819 info
= &intr_block
->ary
[cpuid
][intr
];
820 list
= &info
->i_reclist
;
823 * The loop must be entered with one critical section held. The thread
824 * does not hold the mplock on startup.
827 lseconds
= gd
->gd_time_seconds
;
833 * The chain is only considered MPSAFE if all its interrupt handlers
834 * are MPSAFE. However, if intr_mpsafe has been turned off we
835 * always operate with the BGL.
837 if (info
->i_mplock_required
!= mpheld
) {
838 if (info
->i_mplock_required
) {
839 KKASSERT(mpheld
== 0);
843 KKASSERT(mpheld
!= 0);
849 TD_INVARIANTS_GET(gd
->gd_curthread
);
852 * If an interrupt is pending, clear i_running and execute the
853 * handlers. Note that certain types of interrupts can re-trigger
854 * and set i_running again.
856 * Each handler is run in a critical section. Note that we run both
857 * FAST and SLOW designated service routines.
859 if (info
->i_running
) {
864 report_stray_interrupt(info
, "ithread_handler");
866 for (rec
= *list
; rec
; rec
= nrec
) {
867 /* rec may be invalid after call */
869 if (rec
->serializer
) {
870 lwkt_serialize_handler_call(rec
->serializer
, rec
->handler
,
871 rec
->argument
, NULL
);
873 rec
->handler(rec
->argument
, NULL
);
875 TD_INVARIANTS_TEST(gd
->gd_curthread
, rec
->name
);
880 * This is our interrupt hook to add rate randomness to the random
883 if (info
->i_random
.sc_enabled
> 0)
884 add_interrupt_randomness(intr
);
887 * Unmask the interrupt to allow it to trigger again. This only
888 * applies to certain types of interrupts (typ level interrupts).
889 * This can result in the interrupt retriggering, but the retrigger
890 * will not be processed until we cycle our critical section.
892 * Only unmask interrupts while handlers are installed. It is
893 * possible to hit a situation where no handlers are installed
894 * due to a device driver livelocking and then tearing down its
895 * interrupt on close (the parallel bus being a good example).
897 if (intr
< FIRST_SOFTINT
&& *list
)
898 machintr_intr_enable(intr
);
901 * Do a quick exit/enter to catch any higher-priority interrupt
902 * sources, such as the statclock, so thread time accounting
903 * will still work. This may also cause an interrupt to re-trigger.
909 * LIVELOCK STATE MACHINE
911 switch(info
->i_state
) {
914 * Reset the count each second.
916 if (lseconds
!= gd
->gd_time_seconds
) {
917 lseconds
= gd
->gd_time_seconds
;
922 * If we did not exceed the frequency limit, we are done.
923 * If the interrupt has not retriggered we deschedule ourselves.
925 if (ill_count
<= livelock_limit
) {
926 if (info
->i_running
== 0) {
927 lwkt_deschedule_self(gd
->gd_curthread
);
934 * Otherwise we are livelocked. Set up a periodic systimer
935 * to wake the thread up at the limit frequency.
937 kprintf("intr %d on cpu%d at %d/%d hz, livelocked limit engaged!\n",
938 intr
, cpuid
, ill_count
, livelock_limit
);
939 info
->i_state
= ISTATE_LIVELOCKED
;
940 if ((use_limit
= livelock_limit
) < 100)
942 else if (use_limit
> 500000)
944 systimer_init_periodic_nq(&ill_timer
, ithread_livelock_wakeup
,
945 (void *)(intptr_t)intr
, use_limit
);
947 case ISTATE_LIVELOCKED
:
949 * Wait for our periodic timer to go off. Since the interrupt
950 * has re-armed it can still set i_running, but it will not
951 * reschedule us while we are in a livelocked state.
953 lwkt_deschedule_self(gd
->gd_curthread
);
957 * Check once a second to see if the livelock condition no
960 if (lseconds
!= gd
->gd_time_seconds
) {
961 lseconds
= gd
->gd_time_seconds
;
962 if (ill_count
< livelock_lowater
) {
963 info
->i_state
= ISTATE_NORMAL
;
964 systimer_del(&ill_timer
);
965 kprintf("intr %d on cpu%d at %d/%d hz, livelock removed\n",
966 intr
, cpuid
, ill_count
, livelock_lowater
);
967 } else if (livelock_debug
== intr
||
968 (bootverbose
&& cold
)) {
969 kprintf("intr %d on cpu%d at %d/%d hz, in livelock\n",
970 intr
, cpuid
, ill_count
, livelock_lowater
);
981 * Emergency interrupt polling thread. The thread begins execution
982 * outside a critical section with the BGL held.
984 * If emergency interrupt polling is enabled, this thread will
985 * execute all system interrupts not marked INTR_NOPOLL at the
986 * specified polling frequency.
988 * WARNING! This thread runs *ALL* interrupt service routines that
989 * are not marked INTR_NOPOLL, which basically means everything except
990 * the 8254 clock interrupt and the ATA interrupt. It has very high
991 * overhead and should only be used in situations where the machine
992 * cannot otherwise be made to work. Due to the severe performance
993 * degredation, it should not be enabled on production machines.
996 ithread_emergency(void *arg __unused
)
998 globaldata_t gd
= mycpu
;
999 struct intr_info
*info
;
1001 int intr
, cpuid
= mycpuid
;
1002 TD_INVARIANTS_DECLARE
;
1006 TD_INVARIANTS_GET(gd
->gd_curthread
);
1009 for (intr
= 0; intr
< max_installed_hard_intr
[cpuid
]; ++intr
) {
1010 info
= &intr_block
->ary
[cpuid
][intr
];
1011 for (rec
= info
->i_reclist
; rec
; rec
= nrec
) {
1012 /* rec may be invalid after call */
1014 if ((rec
->intr_flags
& INTR_NOPOLL
) == 0) {
1015 if (rec
->serializer
) {
1016 lwkt_serialize_handler_try(rec
->serializer
,
1017 rec
->handler
, rec
->argument
, NULL
);
1019 rec
->handler(rec
->argument
, NULL
);
1021 TD_INVARIANTS_TEST(gd
->gd_curthread
, rec
->name
);
1025 lwkt_deschedule_self(gd
->gd_curthread
);
1032 * Systimer callback - schedule the emergency interrupt poll thread
1033 * if emergency polling is enabled.
1037 emergency_intr_timer_callback(systimer_t info
, int in_ipi __unused
,
1038 struct intrframe
*frame __unused
)
1040 if (emergency_intr_enable
)
1041 lwkt_schedule(info
->data
);
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 (cpuid
= 0; cpuid
< ncpus
; ++cpuid
) {
1065 for (intr
= 0; error
== 0 && intr
< MAX_INTS
; ++intr
) {
1066 info
= &intr_block
->ary
[cpuid
][intr
];
1070 for (rec
= info
->i_reclist
; rec
; rec
= rec
->next
) {
1071 ksnprintf(buf
+ len
, sizeof(buf
) - len
, "%s%s",
1072 (len
? "/" : ""), rec
->name
);
1073 len
+= strlen(buf
+ len
);
1076 ksnprintf(buf
, sizeof(buf
), "irq%d", intr
);
1079 error
= SYSCTL_OUT(req
, buf
, len
+ 1);
1085 SYSCTL_PROC(_hw
, OID_AUTO
, intrnames
, CTLTYPE_OPAQUE
| CTLFLAG_RD
,
1086 NULL
, 0, sysctl_intrnames
, "", "Interrupt Names");
1089 sysctl_intrcnt_all(SYSCTL_HANDLER_ARGS
)
1091 struct intr_info
*info
;
1095 for (cpuid
= 0; cpuid
< ncpus
; ++cpuid
) {
1096 for (intr
= 0; intr
< MAX_INTS
; ++intr
) {
1097 info
= &intr_block
->ary
[cpuid
][intr
];
1099 error
= SYSCTL_OUT(req
, &info
->i_count
, sizeof(info
->i_count
));
1108 SYSCTL_PROC(_hw
, OID_AUTO
, intrcnt_all
, CTLTYPE_OPAQUE
| CTLFLAG_RD
,
1109 NULL
, 0, sysctl_intrcnt_all
, "", "Interrupt Counts");
1111 SYSCTL_PROC(_hw
, OID_AUTO
, intrcnt
, CTLTYPE_OPAQUE
| CTLFLAG_RD
,
1112 NULL
, 0, sysctl_intrcnt_all
, "", "Interrupt Counts");
1115 int_moveto_destcpu(int *orig_cpuid0
, int cpuid
)
1117 int orig_cpuid
= mycpuid
;
1119 if (cpuid
!= orig_cpuid
)
1120 lwkt_migratecpu(cpuid
);
1122 *orig_cpuid0
= orig_cpuid
;
1126 int_moveto_origcpu(int orig_cpuid
, int cpuid
)
1128 if (cpuid
!= orig_cpuid
)
1129 lwkt_migratecpu(orig_cpuid
);
1133 intr_init(void *dummy __unused
)
1137 kprintf("Initialize MI interrupts\n");
1139 intr_block
= kmalloc(sizeof(*intr_block
), M_INTRMNG
,
1140 M_INTWAIT
| M_ZERO
);
1142 for (cpuid
= 0; cpuid
< ncpus
; ++cpuid
) {
1145 for (intr
= 0; intr
< MAX_INTS
; ++intr
) {
1146 struct intr_info
*info
= &intr_block
->ary
[cpuid
][intr
];
1148 info
->i_cpuid
= cpuid
;
1149 info
->i_intr
= intr
;
1153 SYSINIT(intr_init
, SI_BOOT2_FINISH_PIC
, SI_ORDER_ANY
, intr_init
, NULL
);