FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_intr.c
1 /*-
2 * Copyright (c) 1997, Stefan Esser <se@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
10 * disclaimer.
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.
14 *
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.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/8.0/sys/kern/kern_intr.c 195249 2009-07-01 17:20:07Z jhb $");
29
30 #include "opt_ddb.h"
31
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/conf.h>
35 #include <sys/cpuset.h>
36 #include <sys/rtprio.h>
37 #include <sys/systm.h>
38 #include <sys/interrupt.h>
39 #include <sys/kernel.h>
40 #include <sys/kthread.h>
41 #include <sys/ktr.h>
42 #include <sys/limits.h>
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/mutex.h>
46 #include <sys/priv.h>
47 #include <sys/proc.h>
48 #include <sys/random.h>
49 #include <sys/resourcevar.h>
50 #include <sys/sched.h>
51 #include <sys/smp.h>
52 #include <sys/sysctl.h>
53 #include <sys/syslog.h>
54 #include <sys/unistd.h>
55 #include <sys/vmmeter.h>
56 #include <machine/atomic.h>
57 #include <machine/cpu.h>
58 #include <machine/md_var.h>
59 #include <machine/stdarg.h>
60 #ifdef DDB
61 #include <ddb/ddb.h>
62 #include <ddb/db_sym.h>
63 #endif
64
65 /*
66 * Describe an interrupt thread. There is one of these per interrupt event.
67 */
68 struct intr_thread {
69 struct intr_event *it_event;
70 struct thread *it_thread; /* Kernel thread. */
71 int it_flags; /* (j) IT_* flags. */
72 int it_need; /* Needs service. */
73 };
74
75 /* Interrupt thread flags kept in it_flags */
76 #define IT_DEAD 0x000001 /* Thread is waiting to exit. */
77
78 struct intr_entropy {
79 struct thread *td;
80 uintptr_t event;
81 };
82
83 struct intr_event *clk_intr_event;
84 struct intr_event *tty_intr_event;
85 void *vm_ih;
86 struct proc *intrproc;
87
88 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads");
89
90 static int intr_storm_threshold = 1000;
91 TUNABLE_INT("hw.intr_storm_threshold", &intr_storm_threshold);
92 SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RW,
93 &intr_storm_threshold, 0,
94 "Number of consecutive interrupts before storm protection is enabled");
95 static TAILQ_HEAD(, intr_event) event_list =
96 TAILQ_HEAD_INITIALIZER(event_list);
97 static struct mtx event_lock;
98 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF);
99
100 static void intr_event_update(struct intr_event *ie);
101 #ifdef INTR_FILTER
102 static int intr_event_schedule_thread(struct intr_event *ie,
103 struct intr_thread *ithd);
104 static int intr_filter_loop(struct intr_event *ie,
105 struct trapframe *frame, struct intr_thread **ithd);
106 static struct intr_thread *ithread_create(const char *name,
107 struct intr_handler *ih);
108 #else
109 static int intr_event_schedule_thread(struct intr_event *ie);
110 static struct intr_thread *ithread_create(const char *name);
111 #endif
112 static void ithread_destroy(struct intr_thread *ithread);
113 static void ithread_execute_handlers(struct proc *p,
114 struct intr_event *ie);
115 #ifdef INTR_FILTER
116 static void priv_ithread_execute_handler(struct proc *p,
117 struct intr_handler *ih);
118 #endif
119 static void ithread_loop(void *);
120 static void ithread_update(struct intr_thread *ithd);
121 static void start_softintr(void *);
122
123 /* Map an interrupt type to an ithread priority. */
124 u_char
125 intr_priority(enum intr_type flags)
126 {
127 u_char pri;
128
129 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET |
130 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV);
131 switch (flags) {
132 case INTR_TYPE_TTY:
133 pri = PI_TTYLOW;
134 break;
135 case INTR_TYPE_BIO:
136 /*
137 * XXX We need to refine this. BSD/OS distinguishes
138 * between tape and disk priorities.
139 */
140 pri = PI_DISK;
141 break;
142 case INTR_TYPE_NET:
143 pri = PI_NET;
144 break;
145 case INTR_TYPE_CAM:
146 pri = PI_DISK; /* XXX or PI_CAM? */
147 break;
148 case INTR_TYPE_AV: /* Audio/video */
149 pri = PI_AV;
150 break;
151 case INTR_TYPE_CLK:
152 pri = PI_REALTIME;
153 break;
154 case INTR_TYPE_MISC:
155 pri = PI_DULL; /* don't care */
156 break;
157 default:
158 /* We didn't specify an interrupt level. */
159 panic("intr_priority: no interrupt type in flags");
160 }
161
162 return pri;
163 }
164
165 /*
166 * Update an ithread based on the associated intr_event.
167 */
168 static void
169 ithread_update(struct intr_thread *ithd)
170 {
171 struct intr_event *ie;
172 struct thread *td;
173 u_char pri;
174
175 ie = ithd->it_event;
176 td = ithd->it_thread;
177
178 /* Determine the overall priority of this event. */
179 if (TAILQ_EMPTY(&ie->ie_handlers))
180 pri = PRI_MAX_ITHD;
181 else
182 pri = TAILQ_FIRST(&ie->ie_handlers)->ih_pri;
183
184 /* Update name and priority. */
185 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name));
186 thread_lock(td);
187 sched_prio(td, pri);
188 thread_unlock(td);
189 }
190
191 /*
192 * Regenerate the full name of an interrupt event and update its priority.
193 */
194 static void
195 intr_event_update(struct intr_event *ie)
196 {
197 struct intr_handler *ih;
198 char *last;
199 int missed, space;
200
201 /* Start off with no entropy and just the name of the event. */
202 mtx_assert(&ie->ie_lock, MA_OWNED);
203 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
204 ie->ie_flags &= ~IE_ENTROPY;
205 missed = 0;
206 space = 1;
207
208 /* Run through all the handlers updating values. */
209 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
210 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 <
211 sizeof(ie->ie_fullname)) {
212 strcat(ie->ie_fullname, " ");
213 strcat(ie->ie_fullname, ih->ih_name);
214 space = 0;
215 } else
216 missed++;
217 if (ih->ih_flags & IH_ENTROPY)
218 ie->ie_flags |= IE_ENTROPY;
219 }
220
221 /*
222 * If the handler names were too long, add +'s to indicate missing
223 * names. If we run out of room and still have +'s to add, change
224 * the last character from a + to a *.
225 */
226 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2];
227 while (missed-- > 0) {
228 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) {
229 if (*last == '+') {
230 *last = '*';
231 break;
232 } else
233 *last = '+';
234 } else if (space) {
235 strcat(ie->ie_fullname, " +");
236 space = 0;
237 } else
238 strcat(ie->ie_fullname, "+");
239 }
240
241 /*
242 * If this event has an ithread, update it's priority and
243 * name.
244 */
245 if (ie->ie_thread != NULL)
246 ithread_update(ie->ie_thread);
247 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname);
248 }
249
250 int
251 intr_event_create(struct intr_event **event, void *source, int flags, int irq,
252 void (*pre_ithread)(void *), void (*post_ithread)(void *),
253 void (*post_filter)(void *), int (*assign_cpu)(void *, u_char),
254 const char *fmt, ...)
255 {
256 struct intr_event *ie;
257 va_list ap;
258
259 /* The only valid flag during creation is IE_SOFT. */
260 if ((flags & ~IE_SOFT) != 0)
261 return (EINVAL);
262 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO);
263 ie->ie_source = source;
264 ie->ie_pre_ithread = pre_ithread;
265 ie->ie_post_ithread = post_ithread;
266 ie->ie_post_filter = post_filter;
267 ie->ie_assign_cpu = assign_cpu;
268 ie->ie_flags = flags;
269 ie->ie_irq = irq;
270 ie->ie_cpu = NOCPU;
271 TAILQ_INIT(&ie->ie_handlers);
272 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF);
273
274 va_start(ap, fmt);
275 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap);
276 va_end(ap);
277 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
278 mtx_lock(&event_lock);
279 TAILQ_INSERT_TAIL(&event_list, ie, ie_list);
280 mtx_unlock(&event_lock);
281 if (event != NULL)
282 *event = ie;
283 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name);
284 return (0);
285 }
286
287 /*
288 * Bind an interrupt event to the specified CPU. Note that not all
289 * platforms support binding an interrupt to a CPU. For those
290 * platforms this request will fail. For supported platforms, any
291 * associated ithreads as well as the primary interrupt context will
292 * be bound to the specificed CPU. Using a cpu id of NOCPU unbinds
293 * the interrupt event.
294 */
295 int
296 intr_event_bind(struct intr_event *ie, u_char cpu)
297 {
298 cpuset_t mask;
299 lwpid_t id;
300 int error;
301
302 /* Need a CPU to bind to. */
303 if (cpu != NOCPU && CPU_ABSENT(cpu))
304 return (EINVAL);
305
306 if (ie->ie_assign_cpu == NULL)
307 return (EOPNOTSUPP);
308
309 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR);
310 if (error)
311 return (error);
312
313 /*
314 * If we have any ithreads try to set their mask first to verify
315 * permissions, etc.
316 */
317 mtx_lock(&ie->ie_lock);
318 if (ie->ie_thread != NULL) {
319 CPU_ZERO(&mask);
320 if (cpu == NOCPU)
321 CPU_COPY(cpuset_root, &mask);
322 else
323 CPU_SET(cpu, &mask);
324 id = ie->ie_thread->it_thread->td_tid;
325 mtx_unlock(&ie->ie_lock);
326 error = cpuset_setthread(id, &mask);
327 if (error)
328 return (error);
329 } else
330 mtx_unlock(&ie->ie_lock);
331 error = ie->ie_assign_cpu(ie->ie_source, cpu);
332 if (error) {
333 mtx_lock(&ie->ie_lock);
334 if (ie->ie_thread != NULL) {
335 CPU_ZERO(&mask);
336 if (ie->ie_cpu == NOCPU)
337 CPU_COPY(cpuset_root, &mask);
338 else
339 CPU_SET(cpu, &mask);
340 id = ie->ie_thread->it_thread->td_tid;
341 mtx_unlock(&ie->ie_lock);
342 (void)cpuset_setthread(id, &mask);
343 } else
344 mtx_unlock(&ie->ie_lock);
345 return (error);
346 }
347
348 mtx_lock(&ie->ie_lock);
349 ie->ie_cpu = cpu;
350 mtx_unlock(&ie->ie_lock);
351
352 return (error);
353 }
354
355 static struct intr_event *
356 intr_lookup(int irq)
357 {
358 struct intr_event *ie;
359
360 mtx_lock(&event_lock);
361 TAILQ_FOREACH(ie, &event_list, ie_list)
362 if (ie->ie_irq == irq &&
363 (ie->ie_flags & IE_SOFT) == 0 &&
364 TAILQ_FIRST(&ie->ie_handlers) != NULL)
365 break;
366 mtx_unlock(&event_lock);
367 return (ie);
368 }
369
370 int
371 intr_setaffinity(int irq, void *m)
372 {
373 struct intr_event *ie;
374 cpuset_t *mask;
375 u_char cpu;
376 int n;
377
378 mask = m;
379 cpu = NOCPU;
380 /*
381 * If we're setting all cpus we can unbind. Otherwise make sure
382 * only one cpu is in the set.
383 */
384 if (CPU_CMP(cpuset_root, mask)) {
385 for (n = 0; n < CPU_SETSIZE; n++) {
386 if (!CPU_ISSET(n, mask))
387 continue;
388 if (cpu != NOCPU)
389 return (EINVAL);
390 cpu = (u_char)n;
391 }
392 }
393 ie = intr_lookup(irq);
394 if (ie == NULL)
395 return (ESRCH);
396 return (intr_event_bind(ie, cpu));
397 }
398
399 int
400 intr_getaffinity(int irq, void *m)
401 {
402 struct intr_event *ie;
403 cpuset_t *mask;
404
405 mask = m;
406 ie = intr_lookup(irq);
407 if (ie == NULL)
408 return (ESRCH);
409 CPU_ZERO(mask);
410 mtx_lock(&ie->ie_lock);
411 if (ie->ie_cpu == NOCPU)
412 CPU_COPY(cpuset_root, mask);
413 else
414 CPU_SET(ie->ie_cpu, mask);
415 mtx_unlock(&ie->ie_lock);
416 return (0);
417 }
418
419 int
420 intr_event_destroy(struct intr_event *ie)
421 {
422
423 mtx_lock(&event_lock);
424 mtx_lock(&ie->ie_lock);
425 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
426 mtx_unlock(&ie->ie_lock);
427 mtx_unlock(&event_lock);
428 return (EBUSY);
429 }
430 TAILQ_REMOVE(&event_list, ie, ie_list);
431 #ifndef notyet
432 if (ie->ie_thread != NULL) {
433 ithread_destroy(ie->ie_thread);
434 ie->ie_thread = NULL;
435 }
436 #endif
437 mtx_unlock(&ie->ie_lock);
438 mtx_unlock(&event_lock);
439 mtx_destroy(&ie->ie_lock);
440 free(ie, M_ITHREAD);
441 return (0);
442 }
443
444 #ifndef INTR_FILTER
445 static struct intr_thread *
446 ithread_create(const char *name)
447 {
448 struct intr_thread *ithd;
449 struct thread *td;
450 int error;
451
452 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
453
454 error = kproc_kthread_add(ithread_loop, ithd, &intrproc,
455 &td, RFSTOPPED | RFHIGHPID,
456 0, "intr", "%s", name);
457 if (error)
458 panic("kproc_create() failed with %d", error);
459 thread_lock(td);
460 sched_class(td, PRI_ITHD);
461 TD_SET_IWAIT(td);
462 thread_unlock(td);
463 td->td_pflags |= TDP_ITHREAD;
464 ithd->it_thread = td;
465 CTR2(KTR_INTR, "%s: created %s", __func__, name);
466 return (ithd);
467 }
468 #else
469 static struct intr_thread *
470 ithread_create(const char *name, struct intr_handler *ih)
471 {
472 struct intr_thread *ithd;
473 struct thread *td;
474 int error;
475
476 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
477
478 error = kproc_kthread_add(ithread_loop, ih, &intrproc,
479 &td, RFSTOPPED | RFHIGHPID,
480 0, "intr", "%s", name);
481 if (error)
482 panic("kproc_create() failed with %d", error);
483 thread_lock(td);
484 sched_class(td, PRI_ITHD);
485 TD_SET_IWAIT(td);
486 thread_unlock(td);
487 td->td_pflags |= TDP_ITHREAD;
488 ithd->it_thread = td;
489 CTR2(KTR_INTR, "%s: created %s", __func__, name);
490 return (ithd);
491 }
492 #endif
493
494 static void
495 ithread_destroy(struct intr_thread *ithread)
496 {
497 struct thread *td;
498
499 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name);
500 td = ithread->it_thread;
501 thread_lock(td);
502 ithread->it_flags |= IT_DEAD;
503 if (TD_AWAITING_INTR(td)) {
504 TD_CLR_IWAIT(td);
505 sched_add(td, SRQ_INTR);
506 }
507 thread_unlock(td);
508 }
509
510 #ifndef INTR_FILTER
511 int
512 intr_event_add_handler(struct intr_event *ie, const char *name,
513 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
514 enum intr_type flags, void **cookiep)
515 {
516 struct intr_handler *ih, *temp_ih;
517 struct intr_thread *it;
518
519 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
520 return (EINVAL);
521
522 /* Allocate and populate an interrupt handler structure. */
523 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
524 ih->ih_filter = filter;
525 ih->ih_handler = handler;
526 ih->ih_argument = arg;
527 ih->ih_name = name;
528 ih->ih_event = ie;
529 ih->ih_pri = pri;
530 if (flags & INTR_EXCL)
531 ih->ih_flags = IH_EXCLUSIVE;
532 if (flags & INTR_MPSAFE)
533 ih->ih_flags |= IH_MPSAFE;
534 if (flags & INTR_ENTROPY)
535 ih->ih_flags |= IH_ENTROPY;
536
537 /* We can only have one exclusive handler in a event. */
538 mtx_lock(&ie->ie_lock);
539 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
540 if ((flags & INTR_EXCL) ||
541 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
542 mtx_unlock(&ie->ie_lock);
543 free(ih, M_ITHREAD);
544 return (EINVAL);
545 }
546 }
547
548 /* Add the new handler to the event in priority order. */
549 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
550 if (temp_ih->ih_pri > ih->ih_pri)
551 break;
552 }
553 if (temp_ih == NULL)
554 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
555 else
556 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
557 intr_event_update(ie);
558
559 /* Create a thread if we need one. */
560 while (ie->ie_thread == NULL && handler != NULL) {
561 if (ie->ie_flags & IE_ADDING_THREAD)
562 msleep(ie, &ie->ie_lock, 0, "ithread", 0);
563 else {
564 ie->ie_flags |= IE_ADDING_THREAD;
565 mtx_unlock(&ie->ie_lock);
566 it = ithread_create("intr: newborn");
567 mtx_lock(&ie->ie_lock);
568 ie->ie_flags &= ~IE_ADDING_THREAD;
569 ie->ie_thread = it;
570 it->it_event = ie;
571 ithread_update(it);
572 wakeup(ie);
573 }
574 }
575 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
576 ie->ie_name);
577 mtx_unlock(&ie->ie_lock);
578
579 if (cookiep != NULL)
580 *cookiep = ih;
581 return (0);
582 }
583 #else
584 int
585 intr_event_add_handler(struct intr_event *ie, const char *name,
586 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
587 enum intr_type flags, void **cookiep)
588 {
589 struct intr_handler *ih, *temp_ih;
590 struct intr_thread *it;
591
592 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
593 return (EINVAL);
594
595 /* Allocate and populate an interrupt handler structure. */
596 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
597 ih->ih_filter = filter;
598 ih->ih_handler = handler;
599 ih->ih_argument = arg;
600 ih->ih_name = name;
601 ih->ih_event = ie;
602 ih->ih_pri = pri;
603 if (flags & INTR_EXCL)
604 ih->ih_flags = IH_EXCLUSIVE;
605 if (flags & INTR_MPSAFE)
606 ih->ih_flags |= IH_MPSAFE;
607 if (flags & INTR_ENTROPY)
608 ih->ih_flags |= IH_ENTROPY;
609
610 /* We can only have one exclusive handler in a event. */
611 mtx_lock(&ie->ie_lock);
612 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
613 if ((flags & INTR_EXCL) ||
614 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
615 mtx_unlock(&ie->ie_lock);
616 free(ih, M_ITHREAD);
617 return (EINVAL);
618 }
619 }
620
621 /* Add the new handler to the event in priority order. */
622 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
623 if (temp_ih->ih_pri > ih->ih_pri)
624 break;
625 }
626 if (temp_ih == NULL)
627 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
628 else
629 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
630 intr_event_update(ie);
631
632 /* For filtered handlers, create a private ithread to run on. */
633 if (filter != NULL && handler != NULL) {
634 mtx_unlock(&ie->ie_lock);
635 it = ithread_create("intr: newborn", ih);
636 mtx_lock(&ie->ie_lock);
637 it->it_event = ie;
638 ih->ih_thread = it;
639 ithread_update(it); // XXX - do we really need this?!?!?
640 } else { /* Create the global per-event thread if we need one. */
641 while (ie->ie_thread == NULL && handler != NULL) {
642 if (ie->ie_flags & IE_ADDING_THREAD)
643 msleep(ie, &ie->ie_lock, 0, "ithread", 0);
644 else {
645 ie->ie_flags |= IE_ADDING_THREAD;
646 mtx_unlock(&ie->ie_lock);
647 it = ithread_create("intr: newborn", ih);
648 mtx_lock(&ie->ie_lock);
649 ie->ie_flags &= ~IE_ADDING_THREAD;
650 ie->ie_thread = it;
651 it->it_event = ie;
652 ithread_update(it);
653 wakeup(ie);
654 }
655 }
656 }
657 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
658 ie->ie_name);
659 mtx_unlock(&ie->ie_lock);
660
661 if (cookiep != NULL)
662 *cookiep = ih;
663 return (0);
664 }
665 #endif
666
667 /*
668 * Return the ie_source field from the intr_event an intr_handler is
669 * associated with.
670 */
671 void *
672 intr_handler_source(void *cookie)
673 {
674 struct intr_handler *ih;
675 struct intr_event *ie;
676
677 ih = (struct intr_handler *)cookie;
678 if (ih == NULL)
679 return (NULL);
680 ie = ih->ih_event;
681 KASSERT(ie != NULL,
682 ("interrupt handler \"%s\" has a NULL interrupt event",
683 ih->ih_name));
684 return (ie->ie_source);
685 }
686
687 #ifndef INTR_FILTER
688 int
689 intr_event_remove_handler(void *cookie)
690 {
691 struct intr_handler *handler = (struct intr_handler *)cookie;
692 struct intr_event *ie;
693 #ifdef INVARIANTS
694 struct intr_handler *ih;
695 #endif
696 #ifdef notyet
697 int dead;
698 #endif
699
700 if (handler == NULL)
701 return (EINVAL);
702 ie = handler->ih_event;
703 KASSERT(ie != NULL,
704 ("interrupt handler \"%s\" has a NULL interrupt event",
705 handler->ih_name));
706 mtx_lock(&ie->ie_lock);
707 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
708 ie->ie_name);
709 #ifdef INVARIANTS
710 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
711 if (ih == handler)
712 goto ok;
713 mtx_unlock(&ie->ie_lock);
714 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
715 ih->ih_name, ie->ie_name);
716 ok:
717 #endif
718 /*
719 * If there is no ithread, then just remove the handler and return.
720 * XXX: Note that an INTR_FAST handler might be running on another
721 * CPU!
722 */
723 if (ie->ie_thread == NULL) {
724 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
725 mtx_unlock(&ie->ie_lock);
726 free(handler, M_ITHREAD);
727 return (0);
728 }
729
730 /*
731 * If the interrupt thread is already running, then just mark this
732 * handler as being dead and let the ithread do the actual removal.
733 *
734 * During a cold boot while cold is set, msleep() does not sleep,
735 * so we have to remove the handler here rather than letting the
736 * thread do it.
737 */
738 thread_lock(ie->ie_thread->it_thread);
739 if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) {
740 handler->ih_flags |= IH_DEAD;
741
742 /*
743 * Ensure that the thread will process the handler list
744 * again and remove this handler if it has already passed
745 * it on the list.
746 */
747 ie->ie_thread->it_need = 1;
748 } else
749 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
750 thread_unlock(ie->ie_thread->it_thread);
751 while (handler->ih_flags & IH_DEAD)
752 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
753 intr_event_update(ie);
754 #ifdef notyet
755 /*
756 * XXX: This could be bad in the case of ppbus(8). Also, I think
757 * this could lead to races of stale data when servicing an
758 * interrupt.
759 */
760 dead = 1;
761 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
762 if (!(ih->ih_flags & IH_FAST)) {
763 dead = 0;
764 break;
765 }
766 }
767 if (dead) {
768 ithread_destroy(ie->ie_thread);
769 ie->ie_thread = NULL;
770 }
771 #endif
772 mtx_unlock(&ie->ie_lock);
773 free(handler, M_ITHREAD);
774 return (0);
775 }
776
777 static int
778 intr_event_schedule_thread(struct intr_event *ie)
779 {
780 struct intr_entropy entropy;
781 struct intr_thread *it;
782 struct thread *td;
783 struct thread *ctd;
784 struct proc *p;
785
786 /*
787 * If no ithread or no handlers, then we have a stray interrupt.
788 */
789 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) ||
790 ie->ie_thread == NULL)
791 return (EINVAL);
792
793 ctd = curthread;
794 it = ie->ie_thread;
795 td = it->it_thread;
796 p = td->td_proc;
797
798 /*
799 * If any of the handlers for this ithread claim to be good
800 * sources of entropy, then gather some.
801 */
802 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
803 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
804 p->p_pid, td->td_name);
805 entropy.event = (uintptr_t)ie;
806 entropy.td = ctd;
807 random_harvest(&entropy, sizeof(entropy), 2, 0,
808 RANDOM_INTERRUPT);
809 }
810
811 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
812
813 /*
814 * Set it_need to tell the thread to keep running if it is already
815 * running. Then, lock the thread and see if we actually need to
816 * put it on the runqueue.
817 */
818 it->it_need = 1;
819 thread_lock(td);
820 if (TD_AWAITING_INTR(td)) {
821 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
822 td->td_name);
823 TD_CLR_IWAIT(td);
824 sched_add(td, SRQ_INTR);
825 } else {
826 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
827 __func__, p->p_pid, td->td_name, it->it_need, td->td_state);
828 }
829 thread_unlock(td);
830
831 return (0);
832 }
833 #else
834 int
835 intr_event_remove_handler(void *cookie)
836 {
837 struct intr_handler *handler = (struct intr_handler *)cookie;
838 struct intr_event *ie;
839 struct intr_thread *it;
840 #ifdef INVARIANTS
841 struct intr_handler *ih;
842 #endif
843 #ifdef notyet
844 int dead;
845 #endif
846
847 if (handler == NULL)
848 return (EINVAL);
849 ie = handler->ih_event;
850 KASSERT(ie != NULL,
851 ("interrupt handler \"%s\" has a NULL interrupt event",
852 handler->ih_name));
853 mtx_lock(&ie->ie_lock);
854 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
855 ie->ie_name);
856 #ifdef INVARIANTS
857 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
858 if (ih == handler)
859 goto ok;
860 mtx_unlock(&ie->ie_lock);
861 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
862 ih->ih_name, ie->ie_name);
863 ok:
864 #endif
865 /*
866 * If there are no ithreads (per event and per handler), then
867 * just remove the handler and return.
868 * XXX: Note that an INTR_FAST handler might be running on another CPU!
869 */
870 if (ie->ie_thread == NULL && handler->ih_thread == NULL) {
871 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
872 mtx_unlock(&ie->ie_lock);
873 free(handler, M_ITHREAD);
874 return (0);
875 }
876
877 /* Private or global ithread? */
878 it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread;
879 /*
880 * If the interrupt thread is already running, then just mark this
881 * handler as being dead and let the ithread do the actual removal.
882 *
883 * During a cold boot while cold is set, msleep() does not sleep,
884 * so we have to remove the handler here rather than letting the
885 * thread do it.
886 */
887 thread_lock(it->it_thread);
888 if (!TD_AWAITING_INTR(it->it_thread) && !cold) {
889 handler->ih_flags |= IH_DEAD;
890
891 /*
892 * Ensure that the thread will process the handler list
893 * again and remove this handler if it has already passed
894 * it on the list.
895 */
896 it->it_need = 1;
897 } else
898 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
899 thread_unlock(it->it_thread);
900 while (handler->ih_flags & IH_DEAD)
901 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
902 /*
903 * At this point, the handler has been disconnected from the event,
904 * so we can kill the private ithread if any.
905 */
906 if (handler->ih_thread) {
907 ithread_destroy(handler->ih_thread);
908 handler->ih_thread = NULL;
909 }
910 intr_event_update(ie);
911 #ifdef notyet
912 /*
913 * XXX: This could be bad in the case of ppbus(8). Also, I think
914 * this could lead to races of stale data when servicing an
915 * interrupt.
916 */
917 dead = 1;
918 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
919 if (handler != NULL) {
920 dead = 0;
921 break;
922 }
923 }
924 if (dead) {
925 ithread_destroy(ie->ie_thread);
926 ie->ie_thread = NULL;
927 }
928 #endif
929 mtx_unlock(&ie->ie_lock);
930 free(handler, M_ITHREAD);
931 return (0);
932 }
933
934 static int
935 intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it)
936 {
937 struct intr_entropy entropy;
938 struct thread *td;
939 struct thread *ctd;
940 struct proc *p;
941
942 /*
943 * If no ithread or no handlers, then we have a stray interrupt.
944 */
945 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || it == NULL)
946 return (EINVAL);
947
948 ctd = curthread;
949 td = it->it_thread;
950 p = td->td_proc;
951
952 /*
953 * If any of the handlers for this ithread claim to be good
954 * sources of entropy, then gather some.
955 */
956 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
957 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
958 p->p_pid, td->td_name);
959 entropy.event = (uintptr_t)ie;
960 entropy.td = ctd;
961 random_harvest(&entropy, sizeof(entropy), 2, 0,
962 RANDOM_INTERRUPT);
963 }
964
965 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
966
967 /*
968 * Set it_need to tell the thread to keep running if it is already
969 * running. Then, lock the thread and see if we actually need to
970 * put it on the runqueue.
971 */
972 it->it_need = 1;
973 thread_lock(td);
974 if (TD_AWAITING_INTR(td)) {
975 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
976 td->td_name);
977 TD_CLR_IWAIT(td);
978 sched_add(td, SRQ_INTR);
979 } else {
980 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
981 __func__, p->p_pid, td->td_name, it->it_need, td->td_state);
982 }
983 thread_unlock(td);
984
985 return (0);
986 }
987 #endif
988
989 /*
990 * Allow interrupt event binding for software interrupt handlers -- a no-op,
991 * since interrupts are generated in software rather than being directed by
992 * a PIC.
993 */
994 static int
995 swi_assign_cpu(void *arg, u_char cpu)
996 {
997
998 return (0);
999 }
1000
1001 /*
1002 * Add a software interrupt handler to a specified event. If a given event
1003 * is not specified, then a new event is created.
1004 */
1005 int
1006 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler,
1007 void *arg, int pri, enum intr_type flags, void **cookiep)
1008 {
1009 struct intr_event *ie;
1010 int error;
1011
1012 if (flags & INTR_ENTROPY)
1013 return (EINVAL);
1014
1015 ie = (eventp != NULL) ? *eventp : NULL;
1016
1017 if (ie != NULL) {
1018 if (!(ie->ie_flags & IE_SOFT))
1019 return (EINVAL);
1020 } else {
1021 error = intr_event_create(&ie, NULL, IE_SOFT, 0,
1022 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri);
1023 if (error)
1024 return (error);
1025 if (eventp != NULL)
1026 *eventp = ie;
1027 }
1028 error = intr_event_add_handler(ie, name, NULL, handler, arg,
1029 (pri * RQ_PPQ) + PI_SOFT, flags, cookiep);
1030 if (error)
1031 return (error);
1032 if (pri == SWI_CLOCK) {
1033 struct proc *p;
1034 p = ie->ie_thread->it_thread->td_proc;
1035 PROC_LOCK(p);
1036 p->p_flag |= P_NOLOAD;
1037 PROC_UNLOCK(p);
1038 }
1039 return (0);
1040 }
1041
1042 /*
1043 * Schedule a software interrupt thread.
1044 */
1045 void
1046 swi_sched(void *cookie, int flags)
1047 {
1048 struct intr_handler *ih = (struct intr_handler *)cookie;
1049 struct intr_event *ie = ih->ih_event;
1050 int error;
1051
1052 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name,
1053 ih->ih_need);
1054
1055 /*
1056 * Set ih_need for this handler so that if the ithread is already
1057 * running it will execute this handler on the next pass. Otherwise,
1058 * it will execute it the next time it runs.
1059 */
1060 atomic_store_rel_int(&ih->ih_need, 1);
1061
1062 if (!(flags & SWI_DELAY)) {
1063 PCPU_INC(cnt.v_soft);
1064 #ifdef INTR_FILTER
1065 error = intr_event_schedule_thread(ie, ie->ie_thread);
1066 #else
1067 error = intr_event_schedule_thread(ie);
1068 #endif
1069 KASSERT(error == 0, ("stray software interrupt"));
1070 }
1071 }
1072
1073 /*
1074 * Remove a software interrupt handler. Currently this code does not
1075 * remove the associated interrupt event if it becomes empty. Calling code
1076 * may do so manually via intr_event_destroy(), but that's not really
1077 * an optimal interface.
1078 */
1079 int
1080 swi_remove(void *cookie)
1081 {
1082
1083 return (intr_event_remove_handler(cookie));
1084 }
1085
1086 #ifdef INTR_FILTER
1087 static void
1088 priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih)
1089 {
1090 struct intr_event *ie;
1091
1092 ie = ih->ih_event;
1093 /*
1094 * If this handler is marked for death, remove it from
1095 * the list of handlers and wake up the sleeper.
1096 */
1097 if (ih->ih_flags & IH_DEAD) {
1098 mtx_lock(&ie->ie_lock);
1099 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
1100 ih->ih_flags &= ~IH_DEAD;
1101 wakeup(ih);
1102 mtx_unlock(&ie->ie_lock);
1103 return;
1104 }
1105
1106 /* Execute this handler. */
1107 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1108 __func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument,
1109 ih->ih_name, ih->ih_flags);
1110
1111 if (!(ih->ih_flags & IH_MPSAFE))
1112 mtx_lock(&Giant);
1113 ih->ih_handler(ih->ih_argument);
1114 if (!(ih->ih_flags & IH_MPSAFE))
1115 mtx_unlock(&Giant);
1116 }
1117 #endif
1118
1119 /*
1120 * This is a public function for use by drivers that mux interrupt
1121 * handlers for child devices from their interrupt handler.
1122 */
1123 void
1124 intr_event_execute_handlers(struct proc *p, struct intr_event *ie)
1125 {
1126 struct intr_handler *ih, *ihn;
1127
1128 TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) {
1129 /*
1130 * If this handler is marked for death, remove it from
1131 * the list of handlers and wake up the sleeper.
1132 */
1133 if (ih->ih_flags & IH_DEAD) {
1134 mtx_lock(&ie->ie_lock);
1135 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
1136 ih->ih_flags &= ~IH_DEAD;
1137 wakeup(ih);
1138 mtx_unlock(&ie->ie_lock);
1139 continue;
1140 }
1141
1142 /* Skip filter only handlers */
1143 if (ih->ih_handler == NULL)
1144 continue;
1145
1146 /*
1147 * For software interrupt threads, we only execute
1148 * handlers that have their need flag set. Hardware
1149 * interrupt threads always invoke all of their handlers.
1150 */
1151 if (ie->ie_flags & IE_SOFT) {
1152 if (!ih->ih_need)
1153 continue;
1154 else
1155 atomic_store_rel_int(&ih->ih_need, 0);
1156 }
1157
1158 /* Execute this handler. */
1159 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1160 __func__, p->p_pid, (void *)ih->ih_handler,
1161 ih->ih_argument, ih->ih_name, ih->ih_flags);
1162
1163 if (!(ih->ih_flags & IH_MPSAFE))
1164 mtx_lock(&Giant);
1165 ih->ih_handler(ih->ih_argument);
1166 if (!(ih->ih_flags & IH_MPSAFE))
1167 mtx_unlock(&Giant);
1168 }
1169 }
1170
1171 static void
1172 ithread_execute_handlers(struct proc *p, struct intr_event *ie)
1173 {
1174
1175 /* Interrupt handlers should not sleep. */
1176 if (!(ie->ie_flags & IE_SOFT))
1177 THREAD_NO_SLEEPING();
1178 intr_event_execute_handlers(p, ie);
1179 if (!(ie->ie_flags & IE_SOFT))
1180 THREAD_SLEEPING_OK();
1181
1182 /*
1183 * Interrupt storm handling:
1184 *
1185 * If this interrupt source is currently storming, then throttle
1186 * it to only fire the handler once per clock tick.
1187 *
1188 * If this interrupt source is not currently storming, but the
1189 * number of back to back interrupts exceeds the storm threshold,
1190 * then enter storming mode.
1191 */
1192 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold &&
1193 !(ie->ie_flags & IE_SOFT)) {
1194 /* Report the message only once every second. */
1195 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) {
1196 printf(
1197 "interrupt storm detected on \"%s\"; throttling interrupt source\n",
1198 ie->ie_name);
1199 }
1200 pause("istorm", 1);
1201 } else
1202 ie->ie_count++;
1203
1204 /*
1205 * Now that all the handlers have had a chance to run, reenable
1206 * the interrupt source.
1207 */
1208 if (ie->ie_post_ithread != NULL)
1209 ie->ie_post_ithread(ie->ie_source);
1210 }
1211
1212 #ifndef INTR_FILTER
1213 /*
1214 * This is the main code for interrupt threads.
1215 */
1216 static void
1217 ithread_loop(void *arg)
1218 {
1219 struct intr_thread *ithd;
1220 struct intr_event *ie;
1221 struct thread *td;
1222 struct proc *p;
1223
1224 td = curthread;
1225 p = td->td_proc;
1226 ithd = (struct intr_thread *)arg;
1227 KASSERT(ithd->it_thread == td,
1228 ("%s: ithread and proc linkage out of sync", __func__));
1229 ie = ithd->it_event;
1230 ie->ie_count = 0;
1231
1232 /*
1233 * As long as we have interrupts outstanding, go through the
1234 * list of handlers, giving each one a go at it.
1235 */
1236 for (;;) {
1237 /*
1238 * If we are an orphaned thread, then just die.
1239 */
1240 if (ithd->it_flags & IT_DEAD) {
1241 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1242 p->p_pid, td->td_name);
1243 free(ithd, M_ITHREAD);
1244 kthread_exit();
1245 }
1246
1247 /*
1248 * Service interrupts. If another interrupt arrives while
1249 * we are running, it will set it_need to note that we
1250 * should make another pass.
1251 */
1252 while (ithd->it_need) {
1253 /*
1254 * This might need a full read and write barrier
1255 * to make sure that this write posts before any
1256 * of the memory or device accesses in the
1257 * handlers.
1258 */
1259 atomic_store_rel_int(&ithd->it_need, 0);
1260 ithread_execute_handlers(p, ie);
1261 }
1262 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1263 mtx_assert(&Giant, MA_NOTOWNED);
1264
1265 /*
1266 * Processed all our interrupts. Now get the sched
1267 * lock. This may take a while and it_need may get
1268 * set again, so we have to check it again.
1269 */
1270 thread_lock(td);
1271 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) {
1272 TD_SET_IWAIT(td);
1273 ie->ie_count = 0;
1274 mi_switch(SW_VOL | SWT_IWAIT, NULL);
1275 }
1276 thread_unlock(td);
1277 }
1278 }
1279
1280 /*
1281 * Main interrupt handling body.
1282 *
1283 * Input:
1284 * o ie: the event connected to this interrupt.
1285 * o frame: some archs (i.e. i386) pass a frame to some.
1286 * handlers as their main argument.
1287 * Return value:
1288 * o 0: everything ok.
1289 * o EINVAL: stray interrupt.
1290 */
1291 int
1292 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1293 {
1294 struct intr_handler *ih;
1295 struct thread *td;
1296 int error, ret, thread;
1297
1298 td = curthread;
1299
1300 /* An interrupt with no event or handlers is a stray interrupt. */
1301 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
1302 return (EINVAL);
1303
1304 /*
1305 * Execute fast interrupt handlers directly.
1306 * To support clock handlers, if a handler registers
1307 * with a NULL argument, then we pass it a pointer to
1308 * a trapframe as its argument.
1309 */
1310 td->td_intr_nesting_level++;
1311 thread = 0;
1312 ret = 0;
1313 critical_enter();
1314 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1315 if (ih->ih_filter == NULL) {
1316 thread = 1;
1317 continue;
1318 }
1319 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__,
1320 ih->ih_filter, ih->ih_argument == NULL ? frame :
1321 ih->ih_argument, ih->ih_name);
1322 if (ih->ih_argument == NULL)
1323 ret = ih->ih_filter(frame);
1324 else
1325 ret = ih->ih_filter(ih->ih_argument);
1326 /*
1327 * Wrapper handler special handling:
1328 *
1329 * in some particular cases (like pccard and pccbb),
1330 * the _real_ device handler is wrapped in a couple of
1331 * functions - a filter wrapper and an ithread wrapper.
1332 * In this case (and just in this case), the filter wrapper
1333 * could ask the system to schedule the ithread and mask
1334 * the interrupt source if the wrapped handler is composed
1335 * of just an ithread handler.
1336 *
1337 * TODO: write a generic wrapper to avoid people rolling
1338 * their own
1339 */
1340 if (!thread) {
1341 if (ret == FILTER_SCHEDULE_THREAD)
1342 thread = 1;
1343 }
1344 }
1345
1346 if (thread) {
1347 if (ie->ie_pre_ithread != NULL)
1348 ie->ie_pre_ithread(ie->ie_source);
1349 } else {
1350 if (ie->ie_post_filter != NULL)
1351 ie->ie_post_filter(ie->ie_source);
1352 }
1353
1354 /* Schedule the ithread if needed. */
1355 if (thread) {
1356 error = intr_event_schedule_thread(ie);
1357 #ifndef XEN
1358 KASSERT(error == 0, ("bad stray interrupt"));
1359 #else
1360 if (error != 0)
1361 log(LOG_WARNING, "bad stray interrupt");
1362 #endif
1363 }
1364 critical_exit();
1365 td->td_intr_nesting_level--;
1366 return (0);
1367 }
1368 #else
1369 /*
1370 * This is the main code for interrupt threads.
1371 */
1372 static void
1373 ithread_loop(void *arg)
1374 {
1375 struct intr_thread *ithd;
1376 struct intr_handler *ih;
1377 struct intr_event *ie;
1378 struct thread *td;
1379 struct proc *p;
1380 int priv;
1381
1382 td = curthread;
1383 p = td->td_proc;
1384 ih = (struct intr_handler *)arg;
1385 priv = (ih->ih_thread != NULL) ? 1 : 0;
1386 ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread;
1387 KASSERT(ithd->it_thread == td,
1388 ("%s: ithread and proc linkage out of sync", __func__));
1389 ie = ithd->it_event;
1390 ie->ie_count = 0;
1391
1392 /*
1393 * As long as we have interrupts outstanding, go through the
1394 * list of handlers, giving each one a go at it.
1395 */
1396 for (;;) {
1397 /*
1398 * If we are an orphaned thread, then just die.
1399 */
1400 if (ithd->it_flags & IT_DEAD) {
1401 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1402 p->p_pid, td->td_name);
1403 free(ithd, M_ITHREAD);
1404 kthread_exit();
1405 }
1406
1407 /*
1408 * Service interrupts. If another interrupt arrives while
1409 * we are running, it will set it_need to note that we
1410 * should make another pass.
1411 */
1412 while (ithd->it_need) {
1413 /*
1414 * This might need a full read and write barrier
1415 * to make sure that this write posts before any
1416 * of the memory or device accesses in the
1417 * handlers.
1418 */
1419 atomic_store_rel_int(&ithd->it_need, 0);
1420 if (priv)
1421 priv_ithread_execute_handler(p, ih);
1422 else
1423 ithread_execute_handlers(p, ie);
1424 }
1425 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1426 mtx_assert(&Giant, MA_NOTOWNED);
1427
1428 /*
1429 * Processed all our interrupts. Now get the sched
1430 * lock. This may take a while and it_need may get
1431 * set again, so we have to check it again.
1432 */
1433 thread_lock(td);
1434 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) {
1435 TD_SET_IWAIT(td);
1436 ie->ie_count = 0;
1437 mi_switch(SW_VOL | SWT_IWAIT, NULL);
1438 }
1439 thread_unlock(td);
1440 }
1441 }
1442
1443 /*
1444 * Main loop for interrupt filter.
1445 *
1446 * Some architectures (i386, amd64 and arm) require the optional frame
1447 * parameter, and use it as the main argument for fast handler execution
1448 * when ih_argument == NULL.
1449 *
1450 * Return value:
1451 * o FILTER_STRAY: No filter recognized the event, and no
1452 * filter-less handler is registered on this
1453 * line.
1454 * o FILTER_HANDLED: A filter claimed the event and served it.
1455 * o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at
1456 * least one filter-less handler on this line.
1457 * o FILTER_HANDLED |
1458 * FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for
1459 * scheduling the per-handler ithread.
1460 *
1461 * In case an ithread has to be scheduled, in *ithd there will be a
1462 * pointer to a struct intr_thread containing the thread to be
1463 * scheduled.
1464 */
1465
1466 static int
1467 intr_filter_loop(struct intr_event *ie, struct trapframe *frame,
1468 struct intr_thread **ithd)
1469 {
1470 struct intr_handler *ih;
1471 void *arg;
1472 int ret, thread_only;
1473
1474 ret = 0;
1475 thread_only = 0;
1476 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1477 /*
1478 * Execute fast interrupt handlers directly.
1479 * To support clock handlers, if a handler registers
1480 * with a NULL argument, then we pass it a pointer to
1481 * a trapframe as its argument.
1482 */
1483 arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument);
1484
1485 CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__,
1486 ih->ih_filter, ih->ih_handler, arg, ih->ih_name);
1487
1488 if (ih->ih_filter != NULL)
1489 ret = ih->ih_filter(arg);
1490 else {
1491 thread_only = 1;
1492 continue;
1493 }
1494
1495 if (ret & FILTER_STRAY)
1496 continue;
1497 else {
1498 *ithd = ih->ih_thread;
1499 return (ret);
1500 }
1501 }
1502
1503 /*
1504 * No filters handled the interrupt and we have at least
1505 * one handler without a filter. In this case, we schedule
1506 * all of the filter-less handlers to run in the ithread.
1507 */
1508 if (thread_only) {
1509 *ithd = ie->ie_thread;
1510 return (FILTER_SCHEDULE_THREAD);
1511 }
1512 return (FILTER_STRAY);
1513 }
1514
1515 /*
1516 * Main interrupt handling body.
1517 *
1518 * Input:
1519 * o ie: the event connected to this interrupt.
1520 * o frame: some archs (i.e. i386) pass a frame to some.
1521 * handlers as their main argument.
1522 * Return value:
1523 * o 0: everything ok.
1524 * o EINVAL: stray interrupt.
1525 */
1526 int
1527 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1528 {
1529 struct intr_thread *ithd;
1530 struct thread *td;
1531 int thread;
1532
1533 ithd = NULL;
1534 td = curthread;
1535
1536 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
1537 return (EINVAL);
1538
1539 td->td_intr_nesting_level++;
1540 thread = 0;
1541 critical_enter();
1542 thread = intr_filter_loop(ie, frame, &ithd);
1543 if (thread & FILTER_HANDLED) {
1544 if (ie->ie_post_filter != NULL)
1545 ie->ie_post_filter(ie->ie_source);
1546 } else {
1547 if (ie->ie_pre_ithread != NULL)
1548 ie->ie_pre_ithread(ie->ie_source);
1549 }
1550 critical_exit();
1551
1552 /* Interrupt storm logic */
1553 if (thread & FILTER_STRAY) {
1554 ie->ie_count++;
1555 if (ie->ie_count < intr_storm_threshold)
1556 printf("Interrupt stray detection not present\n");
1557 }
1558
1559 /* Schedule an ithread if needed. */
1560 if (thread & FILTER_SCHEDULE_THREAD) {
1561 if (intr_event_schedule_thread(ie, ithd) != 0)
1562 panic("%s: impossible stray interrupt", __func__);
1563 }
1564 td->td_intr_nesting_level--;
1565 return (0);
1566 }
1567 #endif
1568
1569 #ifdef DDB
1570 /*
1571 * Dump details about an interrupt handler
1572 */
1573 static void
1574 db_dump_intrhand(struct intr_handler *ih)
1575 {
1576 int comma;
1577
1578 db_printf("\t%-10s ", ih->ih_name);
1579 switch (ih->ih_pri) {
1580 case PI_REALTIME:
1581 db_printf("CLK ");
1582 break;
1583 case PI_AV:
1584 db_printf("AV ");
1585 break;
1586 case PI_TTYHIGH:
1587 case PI_TTYLOW:
1588 db_printf("TTY ");
1589 break;
1590 case PI_TAPE:
1591 db_printf("TAPE");
1592 break;
1593 case PI_NET:
1594 db_printf("NET ");
1595 break;
1596 case PI_DISK:
1597 case PI_DISKLOW:
1598 db_printf("DISK");
1599 break;
1600 case PI_DULL:
1601 db_printf("DULL");
1602 break;
1603 default:
1604 if (ih->ih_pri >= PI_SOFT)
1605 db_printf("SWI ");
1606 else
1607 db_printf("%4u", ih->ih_pri);
1608 break;
1609 }
1610 db_printf(" ");
1611 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC);
1612 db_printf("(%p)", ih->ih_argument);
1613 if (ih->ih_need ||
1614 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD |
1615 IH_MPSAFE)) != 0) {
1616 db_printf(" {");
1617 comma = 0;
1618 if (ih->ih_flags & IH_EXCLUSIVE) {
1619 if (comma)
1620 db_printf(", ");
1621 db_printf("EXCL");
1622 comma = 1;
1623 }
1624 if (ih->ih_flags & IH_ENTROPY) {
1625 if (comma)
1626 db_printf(", ");
1627 db_printf("ENTROPY");
1628 comma = 1;
1629 }
1630 if (ih->ih_flags & IH_DEAD) {
1631 if (comma)
1632 db_printf(", ");
1633 db_printf("DEAD");
1634 comma = 1;
1635 }
1636 if (ih->ih_flags & IH_MPSAFE) {
1637 if (comma)
1638 db_printf(", ");
1639 db_printf("MPSAFE");
1640 comma = 1;
1641 }
1642 if (ih->ih_need) {
1643 if (comma)
1644 db_printf(", ");
1645 db_printf("NEED");
1646 }
1647 db_printf("}");
1648 }
1649 db_printf("\n");
1650 }
1651
1652 /*
1653 * Dump details about a event.
1654 */
1655 void
1656 db_dump_intr_event(struct intr_event *ie, int handlers)
1657 {
1658 struct intr_handler *ih;
1659 struct intr_thread *it;
1660 int comma;
1661
1662 db_printf("%s ", ie->ie_fullname);
1663 it = ie->ie_thread;
1664 if (it != NULL)
1665 db_printf("(pid %d)", it->it_thread->td_proc->p_pid);
1666 else
1667 db_printf("(no thread)");
1668 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 ||
1669 (it != NULL && it->it_need)) {
1670 db_printf(" {");
1671 comma = 0;
1672 if (ie->ie_flags & IE_SOFT) {
1673 db_printf("SOFT");
1674 comma = 1;
1675 }
1676 if (ie->ie_flags & IE_ENTROPY) {
1677 if (comma)
1678 db_printf(", ");
1679 db_printf("ENTROPY");
1680 comma = 1;
1681 }
1682 if (ie->ie_flags & IE_ADDING_THREAD) {
1683 if (comma)
1684 db_printf(", ");
1685 db_printf("ADDING_THREAD");
1686 comma = 1;
1687 }
1688 if (it != NULL && it->it_need) {
1689 if (comma)
1690 db_printf(", ");
1691 db_printf("NEED");
1692 }
1693 db_printf("}");
1694 }
1695 db_printf("\n");
1696
1697 if (handlers)
1698 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
1699 db_dump_intrhand(ih);
1700 }
1701
1702 /*
1703 * Dump data about interrupt handlers
1704 */
1705 DB_SHOW_COMMAND(intr, db_show_intr)
1706 {
1707 struct intr_event *ie;
1708 int all, verbose;
1709
1710 verbose = index(modif, 'v') != NULL;
1711 all = index(modif, 'a') != NULL;
1712 TAILQ_FOREACH(ie, &event_list, ie_list) {
1713 if (!all && TAILQ_EMPTY(&ie->ie_handlers))
1714 continue;
1715 db_dump_intr_event(ie, verbose);
1716 if (db_pager_quit)
1717 break;
1718 }
1719 }
1720 #endif /* DDB */
1721
1722 /*
1723 * Start standard software interrupt threads
1724 */
1725 static void
1726 start_softintr(void *dummy)
1727 {
1728
1729 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih))
1730 panic("died while creating vm swi ithread");
1731 }
1732 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr,
1733 NULL);
1734
1735 /*
1736 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
1737 * The data for this machine dependent, and the declarations are in machine
1738 * dependent code. The layout of intrnames and intrcnt however is machine
1739 * independent.
1740 *
1741 * We do not know the length of intrcnt and intrnames at compile time, so
1742 * calculate things at run time.
1743 */
1744 static int
1745 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
1746 {
1747 return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames,
1748 req));
1749 }
1750
1751 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
1752 NULL, 0, sysctl_intrnames, "", "Interrupt Names");
1753
1754 static int
1755 sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
1756 {
1757 return (sysctl_handle_opaque(oidp, intrcnt,
1758 (char *)eintrcnt - (char *)intrcnt, req));
1759 }
1760
1761 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
1762 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
1763
1764 #ifdef DDB
1765 /*
1766 * DDB command to dump the interrupt statistics.
1767 */
1768 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt)
1769 {
1770 u_long *i;
1771 char *cp;
1772
1773 cp = intrnames;
1774 for (i = intrcnt; i != eintrcnt && !db_pager_quit; i++) {
1775 if (*cp == '\0')
1776 break;
1777 if (*i != 0)
1778 db_printf("%s\t%lu\n", cp, *i);
1779 cp += strlen(cp) + 1;
1780 }
1781 }
1782 #endif
Cache object: 5d873d42f1699e3801aca138d07a3f85
|