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: head/sys/kern/kern_intr.c 198854 2009-11-03 16:46:52Z attilio $");
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 strlcpy(ih->ih_name, name, sizeof(ih->ih_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 strlcpy(ih->ih_name, name, sizeof(ih->ih_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 * Append a description preceded by a ':' to the name of the specified
669 * interrupt handler.
670 */
671 int
672 intr_event_describe_handler(struct intr_event *ie, void *cookie,
673 const char *descr)
674 {
675 struct intr_handler *ih;
676 size_t space;
677 char *start;
678
679 mtx_lock(&ie->ie_lock);
680 #ifdef INVARIANTS
681 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
682 if (ih == cookie)
683 break;
684 }
685 if (ih == NULL) {
686 mtx_unlock(&ie->ie_lock);
687 panic("handler %p not found in interrupt event %p", cookie, ie);
688 }
689 #endif
690 ih = cookie;
691
692 /*
693 * Look for an existing description by checking for an
694 * existing ":". This assumes device names do not include
695 * colons. If one is found, prepare to insert the new
696 * description at that point. If one is not found, find the
697 * end of the name to use as the insertion point.
698 */
699 start = index(ih->ih_name, ':');
700 if (start == NULL)
701 start = index(ih->ih_name, 0);
702
703 /*
704 * See if there is enough remaining room in the string for the
705 * description + ":". The "- 1" leaves room for the trailing
706 * '\0'. The "+ 1" accounts for the colon.
707 */
708 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1;
709 if (strlen(descr) + 1 > space) {
710 mtx_unlock(&ie->ie_lock);
711 return (ENOSPC);
712 }
713
714 /* Append a colon followed by the description. */
715 *start = ':';
716 strcpy(start + 1, descr);
717 intr_event_update(ie);
718 mtx_unlock(&ie->ie_lock);
719 return (0);
720 }
721
722 /*
723 * Return the ie_source field from the intr_event an intr_handler is
724 * associated with.
725 */
726 void *
727 intr_handler_source(void *cookie)
728 {
729 struct intr_handler *ih;
730 struct intr_event *ie;
731
732 ih = (struct intr_handler *)cookie;
733 if (ih == NULL)
734 return (NULL);
735 ie = ih->ih_event;
736 KASSERT(ie != NULL,
737 ("interrupt handler \"%s\" has a NULL interrupt event",
738 ih->ih_name));
739 return (ie->ie_source);
740 }
741
742 #ifndef INTR_FILTER
743 int
744 intr_event_remove_handler(void *cookie)
745 {
746 struct intr_handler *handler = (struct intr_handler *)cookie;
747 struct intr_event *ie;
748 #ifdef INVARIANTS
749 struct intr_handler *ih;
750 #endif
751 #ifdef notyet
752 int dead;
753 #endif
754
755 if (handler == NULL)
756 return (EINVAL);
757 ie = handler->ih_event;
758 KASSERT(ie != NULL,
759 ("interrupt handler \"%s\" has a NULL interrupt event",
760 handler->ih_name));
761 mtx_lock(&ie->ie_lock);
762 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
763 ie->ie_name);
764 #ifdef INVARIANTS
765 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
766 if (ih == handler)
767 goto ok;
768 mtx_unlock(&ie->ie_lock);
769 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
770 ih->ih_name, ie->ie_name);
771 ok:
772 #endif
773 /*
774 * If there is no ithread, then just remove the handler and return.
775 * XXX: Note that an INTR_FAST handler might be running on another
776 * CPU!
777 */
778 if (ie->ie_thread == NULL) {
779 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
780 mtx_unlock(&ie->ie_lock);
781 free(handler, M_ITHREAD);
782 return (0);
783 }
784
785 /*
786 * If the interrupt thread is already running, then just mark this
787 * handler as being dead and let the ithread do the actual removal.
788 *
789 * During a cold boot while cold is set, msleep() does not sleep,
790 * so we have to remove the handler here rather than letting the
791 * thread do it.
792 */
793 thread_lock(ie->ie_thread->it_thread);
794 if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) {
795 handler->ih_flags |= IH_DEAD;
796
797 /*
798 * Ensure that the thread will process the handler list
799 * again and remove this handler if it has already passed
800 * it on the list.
801 */
802 ie->ie_thread->it_need = 1;
803 } else
804 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
805 thread_unlock(ie->ie_thread->it_thread);
806 while (handler->ih_flags & IH_DEAD)
807 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
808 intr_event_update(ie);
809 #ifdef notyet
810 /*
811 * XXX: This could be bad in the case of ppbus(8). Also, I think
812 * this could lead to races of stale data when servicing an
813 * interrupt.
814 */
815 dead = 1;
816 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
817 if (!(ih->ih_flags & IH_FAST)) {
818 dead = 0;
819 break;
820 }
821 }
822 if (dead) {
823 ithread_destroy(ie->ie_thread);
824 ie->ie_thread = NULL;
825 }
826 #endif
827 mtx_unlock(&ie->ie_lock);
828 free(handler, M_ITHREAD);
829 return (0);
830 }
831
832 static int
833 intr_event_schedule_thread(struct intr_event *ie)
834 {
835 struct intr_entropy entropy;
836 struct intr_thread *it;
837 struct thread *td;
838 struct thread *ctd;
839 struct proc *p;
840
841 /*
842 * If no ithread or no handlers, then we have a stray interrupt.
843 */
844 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) ||
845 ie->ie_thread == NULL)
846 return (EINVAL);
847
848 ctd = curthread;
849 it = ie->ie_thread;
850 td = it->it_thread;
851 p = td->td_proc;
852
853 /*
854 * If any of the handlers for this ithread claim to be good
855 * sources of entropy, then gather some.
856 */
857 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
858 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
859 p->p_pid, td->td_name);
860 entropy.event = (uintptr_t)ie;
861 entropy.td = ctd;
862 random_harvest(&entropy, sizeof(entropy), 2, 0,
863 RANDOM_INTERRUPT);
864 }
865
866 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
867
868 /*
869 * Set it_need to tell the thread to keep running if it is already
870 * running. Then, lock the thread and see if we actually need to
871 * put it on the runqueue.
872 */
873 it->it_need = 1;
874 thread_lock(td);
875 if (TD_AWAITING_INTR(td)) {
876 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
877 td->td_name);
878 TD_CLR_IWAIT(td);
879 sched_add(td, SRQ_INTR);
880 } else {
881 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
882 __func__, p->p_pid, td->td_name, it->it_need, td->td_state);
883 }
884 thread_unlock(td);
885
886 return (0);
887 }
888 #else
889 int
890 intr_event_remove_handler(void *cookie)
891 {
892 struct intr_handler *handler = (struct intr_handler *)cookie;
893 struct intr_event *ie;
894 struct intr_thread *it;
895 #ifdef INVARIANTS
896 struct intr_handler *ih;
897 #endif
898 #ifdef notyet
899 int dead;
900 #endif
901
902 if (handler == NULL)
903 return (EINVAL);
904 ie = handler->ih_event;
905 KASSERT(ie != NULL,
906 ("interrupt handler \"%s\" has a NULL interrupt event",
907 handler->ih_name));
908 mtx_lock(&ie->ie_lock);
909 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
910 ie->ie_name);
911 #ifdef INVARIANTS
912 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
913 if (ih == handler)
914 goto ok;
915 mtx_unlock(&ie->ie_lock);
916 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
917 ih->ih_name, ie->ie_name);
918 ok:
919 #endif
920 /*
921 * If there are no ithreads (per event and per handler), then
922 * just remove the handler and return.
923 * XXX: Note that an INTR_FAST handler might be running on another CPU!
924 */
925 if (ie->ie_thread == NULL && handler->ih_thread == NULL) {
926 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
927 mtx_unlock(&ie->ie_lock);
928 free(handler, M_ITHREAD);
929 return (0);
930 }
931
932 /* Private or global ithread? */
933 it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread;
934 /*
935 * If the interrupt thread is already running, then just mark this
936 * handler as being dead and let the ithread do the actual removal.
937 *
938 * During a cold boot while cold is set, msleep() does not sleep,
939 * so we have to remove the handler here rather than letting the
940 * thread do it.
941 */
942 thread_lock(it->it_thread);
943 if (!TD_AWAITING_INTR(it->it_thread) && !cold) {
944 handler->ih_flags |= IH_DEAD;
945
946 /*
947 * Ensure that the thread will process the handler list
948 * again and remove this handler if it has already passed
949 * it on the list.
950 */
951 it->it_need = 1;
952 } else
953 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
954 thread_unlock(it->it_thread);
955 while (handler->ih_flags & IH_DEAD)
956 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
957 /*
958 * At this point, the handler has been disconnected from the event,
959 * so we can kill the private ithread if any.
960 */
961 if (handler->ih_thread) {
962 ithread_destroy(handler->ih_thread);
963 handler->ih_thread = NULL;
964 }
965 intr_event_update(ie);
966 #ifdef notyet
967 /*
968 * XXX: This could be bad in the case of ppbus(8). Also, I think
969 * this could lead to races of stale data when servicing an
970 * interrupt.
971 */
972 dead = 1;
973 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
974 if (handler != NULL) {
975 dead = 0;
976 break;
977 }
978 }
979 if (dead) {
980 ithread_destroy(ie->ie_thread);
981 ie->ie_thread = NULL;
982 }
983 #endif
984 mtx_unlock(&ie->ie_lock);
985 free(handler, M_ITHREAD);
986 return (0);
987 }
988
989 static int
990 intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it)
991 {
992 struct intr_entropy entropy;
993 struct thread *td;
994 struct thread *ctd;
995 struct proc *p;
996
997 /*
998 * If no ithread or no handlers, then we have a stray interrupt.
999 */
1000 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || it == NULL)
1001 return (EINVAL);
1002
1003 ctd = curthread;
1004 td = it->it_thread;
1005 p = td->td_proc;
1006
1007 /*
1008 * If any of the handlers for this ithread claim to be good
1009 * sources of entropy, then gather some.
1010 */
1011 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
1012 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
1013 p->p_pid, td->td_name);
1014 entropy.event = (uintptr_t)ie;
1015 entropy.td = ctd;
1016 random_harvest(&entropy, sizeof(entropy), 2, 0,
1017 RANDOM_INTERRUPT);
1018 }
1019
1020 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
1021
1022 /*
1023 * Set it_need to tell the thread to keep running if it is already
1024 * running. Then, lock the thread and see if we actually need to
1025 * put it on the runqueue.
1026 */
1027 it->it_need = 1;
1028 thread_lock(td);
1029 if (TD_AWAITING_INTR(td)) {
1030 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
1031 td->td_name);
1032 TD_CLR_IWAIT(td);
1033 sched_add(td, SRQ_INTR);
1034 } else {
1035 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
1036 __func__, p->p_pid, td->td_name, it->it_need, td->td_state);
1037 }
1038 thread_unlock(td);
1039
1040 return (0);
1041 }
1042 #endif
1043
1044 /*
1045 * Allow interrupt event binding for software interrupt handlers -- a no-op,
1046 * since interrupts are generated in software rather than being directed by
1047 * a PIC.
1048 */
1049 static int
1050 swi_assign_cpu(void *arg, u_char cpu)
1051 {
1052
1053 return (0);
1054 }
1055
1056 /*
1057 * Add a software interrupt handler to a specified event. If a given event
1058 * is not specified, then a new event is created.
1059 */
1060 int
1061 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler,
1062 void *arg, int pri, enum intr_type flags, void **cookiep)
1063 {
1064 struct thread *td;
1065 struct intr_event *ie;
1066 int error;
1067
1068 if (flags & INTR_ENTROPY)
1069 return (EINVAL);
1070
1071 ie = (eventp != NULL) ? *eventp : NULL;
1072
1073 if (ie != NULL) {
1074 if (!(ie->ie_flags & IE_SOFT))
1075 return (EINVAL);
1076 } else {
1077 error = intr_event_create(&ie, NULL, IE_SOFT, 0,
1078 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri);
1079 if (error)
1080 return (error);
1081 if (eventp != NULL)
1082 *eventp = ie;
1083 }
1084 error = intr_event_add_handler(ie, name, NULL, handler, arg,
1085 (pri * RQ_PPQ) + PI_SOFT, flags, cookiep);
1086 if (error)
1087 return (error);
1088 if (pri == SWI_CLOCK) {
1089 td = ie->ie_thread->it_thread;
1090 thread_lock(td);
1091 td->td_flags |= TDF_NOLOAD;
1092 thread_unlock(td);
1093 }
1094 return (0);
1095 }
1096
1097 /*
1098 * Schedule a software interrupt thread.
1099 */
1100 void
1101 swi_sched(void *cookie, int flags)
1102 {
1103 struct intr_handler *ih = (struct intr_handler *)cookie;
1104 struct intr_event *ie = ih->ih_event;
1105 int error;
1106
1107 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name,
1108 ih->ih_need);
1109
1110 /*
1111 * Set ih_need for this handler so that if the ithread is already
1112 * running it will execute this handler on the next pass. Otherwise,
1113 * it will execute it the next time it runs.
1114 */
1115 atomic_store_rel_int(&ih->ih_need, 1);
1116
1117 if (!(flags & SWI_DELAY)) {
1118 PCPU_INC(cnt.v_soft);
1119 #ifdef INTR_FILTER
1120 error = intr_event_schedule_thread(ie, ie->ie_thread);
1121 #else
1122 error = intr_event_schedule_thread(ie);
1123 #endif
1124 KASSERT(error == 0, ("stray software interrupt"));
1125 }
1126 }
1127
1128 /*
1129 * Remove a software interrupt handler. Currently this code does not
1130 * remove the associated interrupt event if it becomes empty. Calling code
1131 * may do so manually via intr_event_destroy(), but that's not really
1132 * an optimal interface.
1133 */
1134 int
1135 swi_remove(void *cookie)
1136 {
1137
1138 return (intr_event_remove_handler(cookie));
1139 }
1140
1141 #ifdef INTR_FILTER
1142 static void
1143 priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih)
1144 {
1145 struct intr_event *ie;
1146
1147 ie = ih->ih_event;
1148 /*
1149 * If this handler is marked for death, remove it from
1150 * the list of handlers and wake up the sleeper.
1151 */
1152 if (ih->ih_flags & IH_DEAD) {
1153 mtx_lock(&ie->ie_lock);
1154 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
1155 ih->ih_flags &= ~IH_DEAD;
1156 wakeup(ih);
1157 mtx_unlock(&ie->ie_lock);
1158 return;
1159 }
1160
1161 /* Execute this handler. */
1162 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1163 __func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument,
1164 ih->ih_name, ih->ih_flags);
1165
1166 if (!(ih->ih_flags & IH_MPSAFE))
1167 mtx_lock(&Giant);
1168 ih->ih_handler(ih->ih_argument);
1169 if (!(ih->ih_flags & IH_MPSAFE))
1170 mtx_unlock(&Giant);
1171 }
1172 #endif
1173
1174 /*
1175 * This is a public function for use by drivers that mux interrupt
1176 * handlers for child devices from their interrupt handler.
1177 */
1178 void
1179 intr_event_execute_handlers(struct proc *p, struct intr_event *ie)
1180 {
1181 struct intr_handler *ih, *ihn;
1182
1183 TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) {
1184 /*
1185 * If this handler is marked for death, remove it from
1186 * the list of handlers and wake up the sleeper.
1187 */
1188 if (ih->ih_flags & IH_DEAD) {
1189 mtx_lock(&ie->ie_lock);
1190 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
1191 ih->ih_flags &= ~IH_DEAD;
1192 wakeup(ih);
1193 mtx_unlock(&ie->ie_lock);
1194 continue;
1195 }
1196
1197 /* Skip filter only handlers */
1198 if (ih->ih_handler == NULL)
1199 continue;
1200
1201 /*
1202 * For software interrupt threads, we only execute
1203 * handlers that have their need flag set. Hardware
1204 * interrupt threads always invoke all of their handlers.
1205 */
1206 if (ie->ie_flags & IE_SOFT) {
1207 if (!ih->ih_need)
1208 continue;
1209 else
1210 atomic_store_rel_int(&ih->ih_need, 0);
1211 }
1212
1213 /* Execute this handler. */
1214 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1215 __func__, p->p_pid, (void *)ih->ih_handler,
1216 ih->ih_argument, ih->ih_name, ih->ih_flags);
1217
1218 if (!(ih->ih_flags & IH_MPSAFE))
1219 mtx_lock(&Giant);
1220 ih->ih_handler(ih->ih_argument);
1221 if (!(ih->ih_flags & IH_MPSAFE))
1222 mtx_unlock(&Giant);
1223 }
1224 }
1225
1226 static void
1227 ithread_execute_handlers(struct proc *p, struct intr_event *ie)
1228 {
1229
1230 /* Interrupt handlers should not sleep. */
1231 if (!(ie->ie_flags & IE_SOFT))
1232 THREAD_NO_SLEEPING();
1233 intr_event_execute_handlers(p, ie);
1234 if (!(ie->ie_flags & IE_SOFT))
1235 THREAD_SLEEPING_OK();
1236
1237 /*
1238 * Interrupt storm handling:
1239 *
1240 * If this interrupt source is currently storming, then throttle
1241 * it to only fire the handler once per clock tick.
1242 *
1243 * If this interrupt source is not currently storming, but the
1244 * number of back to back interrupts exceeds the storm threshold,
1245 * then enter storming mode.
1246 */
1247 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold &&
1248 !(ie->ie_flags & IE_SOFT)) {
1249 /* Report the message only once every second. */
1250 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) {
1251 printf(
1252 "interrupt storm detected on \"%s\"; throttling interrupt source\n",
1253 ie->ie_name);
1254 }
1255 pause("istorm", 1);
1256 } else
1257 ie->ie_count++;
1258
1259 /*
1260 * Now that all the handlers have had a chance to run, reenable
1261 * the interrupt source.
1262 */
1263 if (ie->ie_post_ithread != NULL)
1264 ie->ie_post_ithread(ie->ie_source);
1265 }
1266
1267 #ifndef INTR_FILTER
1268 /*
1269 * This is the main code for interrupt threads.
1270 */
1271 static void
1272 ithread_loop(void *arg)
1273 {
1274 struct intr_thread *ithd;
1275 struct intr_event *ie;
1276 struct thread *td;
1277 struct proc *p;
1278
1279 td = curthread;
1280 p = td->td_proc;
1281 ithd = (struct intr_thread *)arg;
1282 KASSERT(ithd->it_thread == td,
1283 ("%s: ithread and proc linkage out of sync", __func__));
1284 ie = ithd->it_event;
1285 ie->ie_count = 0;
1286
1287 /*
1288 * As long as we have interrupts outstanding, go through the
1289 * list of handlers, giving each one a go at it.
1290 */
1291 for (;;) {
1292 /*
1293 * If we are an orphaned thread, then just die.
1294 */
1295 if (ithd->it_flags & IT_DEAD) {
1296 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1297 p->p_pid, td->td_name);
1298 free(ithd, M_ITHREAD);
1299 kthread_exit();
1300 }
1301
1302 /*
1303 * Service interrupts. If another interrupt arrives while
1304 * we are running, it will set it_need to note that we
1305 * should make another pass.
1306 */
1307 while (ithd->it_need) {
1308 /*
1309 * This might need a full read and write barrier
1310 * to make sure that this write posts before any
1311 * of the memory or device accesses in the
1312 * handlers.
1313 */
1314 atomic_store_rel_int(&ithd->it_need, 0);
1315 ithread_execute_handlers(p, ie);
1316 }
1317 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1318 mtx_assert(&Giant, MA_NOTOWNED);
1319
1320 /*
1321 * Processed all our interrupts. Now get the sched
1322 * lock. This may take a while and it_need may get
1323 * set again, so we have to check it again.
1324 */
1325 thread_lock(td);
1326 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) {
1327 TD_SET_IWAIT(td);
1328 ie->ie_count = 0;
1329 mi_switch(SW_VOL | SWT_IWAIT, NULL);
1330 }
1331 thread_unlock(td);
1332 }
1333 }
1334
1335 /*
1336 * Main interrupt handling body.
1337 *
1338 * Input:
1339 * o ie: the event connected to this interrupt.
1340 * o frame: some archs (i.e. i386) pass a frame to some.
1341 * handlers as their main argument.
1342 * Return value:
1343 * o 0: everything ok.
1344 * o EINVAL: stray interrupt.
1345 */
1346 int
1347 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1348 {
1349 struct intr_handler *ih;
1350 struct thread *td;
1351 int error, ret, thread;
1352
1353 td = curthread;
1354
1355 /* An interrupt with no event or handlers is a stray interrupt. */
1356 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
1357 return (EINVAL);
1358
1359 /*
1360 * Execute fast interrupt handlers directly.
1361 * To support clock handlers, if a handler registers
1362 * with a NULL argument, then we pass it a pointer to
1363 * a trapframe as its argument.
1364 */
1365 td->td_intr_nesting_level++;
1366 thread = 0;
1367 ret = 0;
1368 critical_enter();
1369 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1370 if (ih->ih_filter == NULL) {
1371 thread = 1;
1372 continue;
1373 }
1374 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__,
1375 ih->ih_filter, ih->ih_argument == NULL ? frame :
1376 ih->ih_argument, ih->ih_name);
1377 if (ih->ih_argument == NULL)
1378 ret = ih->ih_filter(frame);
1379 else
1380 ret = ih->ih_filter(ih->ih_argument);
1381 /*
1382 * Wrapper handler special handling:
1383 *
1384 * in some particular cases (like pccard and pccbb),
1385 * the _real_ device handler is wrapped in a couple of
1386 * functions - a filter wrapper and an ithread wrapper.
1387 * In this case (and just in this case), the filter wrapper
1388 * could ask the system to schedule the ithread and mask
1389 * the interrupt source if the wrapped handler is composed
1390 * of just an ithread handler.
1391 *
1392 * TODO: write a generic wrapper to avoid people rolling
1393 * their own
1394 */
1395 if (!thread) {
1396 if (ret == FILTER_SCHEDULE_THREAD)
1397 thread = 1;
1398 }
1399 }
1400
1401 if (thread) {
1402 if (ie->ie_pre_ithread != NULL)
1403 ie->ie_pre_ithread(ie->ie_source);
1404 } else {
1405 if (ie->ie_post_filter != NULL)
1406 ie->ie_post_filter(ie->ie_source);
1407 }
1408
1409 /* Schedule the ithread if needed. */
1410 if (thread) {
1411 error = intr_event_schedule_thread(ie);
1412 #ifndef XEN
1413 KASSERT(error == 0, ("bad stray interrupt"));
1414 #else
1415 if (error != 0)
1416 log(LOG_WARNING, "bad stray interrupt");
1417 #endif
1418 }
1419 critical_exit();
1420 td->td_intr_nesting_level--;
1421 return (0);
1422 }
1423 #else
1424 /*
1425 * This is the main code for interrupt threads.
1426 */
1427 static void
1428 ithread_loop(void *arg)
1429 {
1430 struct intr_thread *ithd;
1431 struct intr_handler *ih;
1432 struct intr_event *ie;
1433 struct thread *td;
1434 struct proc *p;
1435 int priv;
1436
1437 td = curthread;
1438 p = td->td_proc;
1439 ih = (struct intr_handler *)arg;
1440 priv = (ih->ih_thread != NULL) ? 1 : 0;
1441 ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread;
1442 KASSERT(ithd->it_thread == td,
1443 ("%s: ithread and proc linkage out of sync", __func__));
1444 ie = ithd->it_event;
1445 ie->ie_count = 0;
1446
1447 /*
1448 * As long as we have interrupts outstanding, go through the
1449 * list of handlers, giving each one a go at it.
1450 */
1451 for (;;) {
1452 /*
1453 * If we are an orphaned thread, then just die.
1454 */
1455 if (ithd->it_flags & IT_DEAD) {
1456 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1457 p->p_pid, td->td_name);
1458 free(ithd, M_ITHREAD);
1459 kthread_exit();
1460 }
1461
1462 /*
1463 * Service interrupts. If another interrupt arrives while
1464 * we are running, it will set it_need to note that we
1465 * should make another pass.
1466 */
1467 while (ithd->it_need) {
1468 /*
1469 * This might need a full read and write barrier
1470 * to make sure that this write posts before any
1471 * of the memory or device accesses in the
1472 * handlers.
1473 */
1474 atomic_store_rel_int(&ithd->it_need, 0);
1475 if (priv)
1476 priv_ithread_execute_handler(p, ih);
1477 else
1478 ithread_execute_handlers(p, ie);
1479 }
1480 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1481 mtx_assert(&Giant, MA_NOTOWNED);
1482
1483 /*
1484 * Processed all our interrupts. Now get the sched
1485 * lock. This may take a while and it_need may get
1486 * set again, so we have to check it again.
1487 */
1488 thread_lock(td);
1489 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) {
1490 TD_SET_IWAIT(td);
1491 ie->ie_count = 0;
1492 mi_switch(SW_VOL | SWT_IWAIT, NULL);
1493 }
1494 thread_unlock(td);
1495 }
1496 }
1497
1498 /*
1499 * Main loop for interrupt filter.
1500 *
1501 * Some architectures (i386, amd64 and arm) require the optional frame
1502 * parameter, and use it as the main argument for fast handler execution
1503 * when ih_argument == NULL.
1504 *
1505 * Return value:
1506 * o FILTER_STRAY: No filter recognized the event, and no
1507 * filter-less handler is registered on this
1508 * line.
1509 * o FILTER_HANDLED: A filter claimed the event and served it.
1510 * o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at
1511 * least one filter-less handler on this line.
1512 * o FILTER_HANDLED |
1513 * FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for
1514 * scheduling the per-handler ithread.
1515 *
1516 * In case an ithread has to be scheduled, in *ithd there will be a
1517 * pointer to a struct intr_thread containing the thread to be
1518 * scheduled.
1519 */
1520
1521 static int
1522 intr_filter_loop(struct intr_event *ie, struct trapframe *frame,
1523 struct intr_thread **ithd)
1524 {
1525 struct intr_handler *ih;
1526 void *arg;
1527 int ret, thread_only;
1528
1529 ret = 0;
1530 thread_only = 0;
1531 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1532 /*
1533 * Execute fast interrupt handlers directly.
1534 * To support clock handlers, if a handler registers
1535 * with a NULL argument, then we pass it a pointer to
1536 * a trapframe as its argument.
1537 */
1538 arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument);
1539
1540 CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__,
1541 ih->ih_filter, ih->ih_handler, arg, ih->ih_name);
1542
1543 if (ih->ih_filter != NULL)
1544 ret = ih->ih_filter(arg);
1545 else {
1546 thread_only = 1;
1547 continue;
1548 }
1549
1550 if (ret & FILTER_STRAY)
1551 continue;
1552 else {
1553 *ithd = ih->ih_thread;
1554 return (ret);
1555 }
1556 }
1557
1558 /*
1559 * No filters handled the interrupt and we have at least
1560 * one handler without a filter. In this case, we schedule
1561 * all of the filter-less handlers to run in the ithread.
1562 */
1563 if (thread_only) {
1564 *ithd = ie->ie_thread;
1565 return (FILTER_SCHEDULE_THREAD);
1566 }
1567 return (FILTER_STRAY);
1568 }
1569
1570 /*
1571 * Main interrupt handling body.
1572 *
1573 * Input:
1574 * o ie: the event connected to this interrupt.
1575 * o frame: some archs (i.e. i386) pass a frame to some.
1576 * handlers as their main argument.
1577 * Return value:
1578 * o 0: everything ok.
1579 * o EINVAL: stray interrupt.
1580 */
1581 int
1582 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1583 {
1584 struct intr_thread *ithd;
1585 struct thread *td;
1586 int thread;
1587
1588 ithd = NULL;
1589 td = curthread;
1590
1591 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
1592 return (EINVAL);
1593
1594 td->td_intr_nesting_level++;
1595 thread = 0;
1596 critical_enter();
1597 thread = intr_filter_loop(ie, frame, &ithd);
1598 if (thread & FILTER_HANDLED) {
1599 if (ie->ie_post_filter != NULL)
1600 ie->ie_post_filter(ie->ie_source);
1601 } else {
1602 if (ie->ie_pre_ithread != NULL)
1603 ie->ie_pre_ithread(ie->ie_source);
1604 }
1605 critical_exit();
1606
1607 /* Interrupt storm logic */
1608 if (thread & FILTER_STRAY) {
1609 ie->ie_count++;
1610 if (ie->ie_count < intr_storm_threshold)
1611 printf("Interrupt stray detection not present\n");
1612 }
1613
1614 /* Schedule an ithread if needed. */
1615 if (thread & FILTER_SCHEDULE_THREAD) {
1616 if (intr_event_schedule_thread(ie, ithd) != 0)
1617 panic("%s: impossible stray interrupt", __func__);
1618 }
1619 td->td_intr_nesting_level--;
1620 return (0);
1621 }
1622 #endif
1623
1624 #ifdef DDB
1625 /*
1626 * Dump details about an interrupt handler
1627 */
1628 static void
1629 db_dump_intrhand(struct intr_handler *ih)
1630 {
1631 int comma;
1632
1633 db_printf("\t%-10s ", ih->ih_name);
1634 switch (ih->ih_pri) {
1635 case PI_REALTIME:
1636 db_printf("CLK ");
1637 break;
1638 case PI_AV:
1639 db_printf("AV ");
1640 break;
1641 case PI_TTYHIGH:
1642 case PI_TTYLOW:
1643 db_printf("TTY ");
1644 break;
1645 case PI_TAPE:
1646 db_printf("TAPE");
1647 break;
1648 case PI_NET:
1649 db_printf("NET ");
1650 break;
1651 case PI_DISK:
1652 case PI_DISKLOW:
1653 db_printf("DISK");
1654 break;
1655 case PI_DULL:
1656 db_printf("DULL");
1657 break;
1658 default:
1659 if (ih->ih_pri >= PI_SOFT)
1660 db_printf("SWI ");
1661 else
1662 db_printf("%4u", ih->ih_pri);
1663 break;
1664 }
1665 db_printf(" ");
1666 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC);
1667 db_printf("(%p)", ih->ih_argument);
1668 if (ih->ih_need ||
1669 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD |
1670 IH_MPSAFE)) != 0) {
1671 db_printf(" {");
1672 comma = 0;
1673 if (ih->ih_flags & IH_EXCLUSIVE) {
1674 if (comma)
1675 db_printf(", ");
1676 db_printf("EXCL");
1677 comma = 1;
1678 }
1679 if (ih->ih_flags & IH_ENTROPY) {
1680 if (comma)
1681 db_printf(", ");
1682 db_printf("ENTROPY");
1683 comma = 1;
1684 }
1685 if (ih->ih_flags & IH_DEAD) {
1686 if (comma)
1687 db_printf(", ");
1688 db_printf("DEAD");
1689 comma = 1;
1690 }
1691 if (ih->ih_flags & IH_MPSAFE) {
1692 if (comma)
1693 db_printf(", ");
1694 db_printf("MPSAFE");
1695 comma = 1;
1696 }
1697 if (ih->ih_need) {
1698 if (comma)
1699 db_printf(", ");
1700 db_printf("NEED");
1701 }
1702 db_printf("}");
1703 }
1704 db_printf("\n");
1705 }
1706
1707 /*
1708 * Dump details about a event.
1709 */
1710 void
1711 db_dump_intr_event(struct intr_event *ie, int handlers)
1712 {
1713 struct intr_handler *ih;
1714 struct intr_thread *it;
1715 int comma;
1716
1717 db_printf("%s ", ie->ie_fullname);
1718 it = ie->ie_thread;
1719 if (it != NULL)
1720 db_printf("(pid %d)", it->it_thread->td_proc->p_pid);
1721 else
1722 db_printf("(no thread)");
1723 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 ||
1724 (it != NULL && it->it_need)) {
1725 db_printf(" {");
1726 comma = 0;
1727 if (ie->ie_flags & IE_SOFT) {
1728 db_printf("SOFT");
1729 comma = 1;
1730 }
1731 if (ie->ie_flags & IE_ENTROPY) {
1732 if (comma)
1733 db_printf(", ");
1734 db_printf("ENTROPY");
1735 comma = 1;
1736 }
1737 if (ie->ie_flags & IE_ADDING_THREAD) {
1738 if (comma)
1739 db_printf(", ");
1740 db_printf("ADDING_THREAD");
1741 comma = 1;
1742 }
1743 if (it != NULL && it->it_need) {
1744 if (comma)
1745 db_printf(", ");
1746 db_printf("NEED");
1747 }
1748 db_printf("}");
1749 }
1750 db_printf("\n");
1751
1752 if (handlers)
1753 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
1754 db_dump_intrhand(ih);
1755 }
1756
1757 /*
1758 * Dump data about interrupt handlers
1759 */
1760 DB_SHOW_COMMAND(intr, db_show_intr)
1761 {
1762 struct intr_event *ie;
1763 int all, verbose;
1764
1765 verbose = index(modif, 'v') != NULL;
1766 all = index(modif, 'a') != NULL;
1767 TAILQ_FOREACH(ie, &event_list, ie_list) {
1768 if (!all && TAILQ_EMPTY(&ie->ie_handlers))
1769 continue;
1770 db_dump_intr_event(ie, verbose);
1771 if (db_pager_quit)
1772 break;
1773 }
1774 }
1775 #endif /* DDB */
1776
1777 /*
1778 * Start standard software interrupt threads
1779 */
1780 static void
1781 start_softintr(void *dummy)
1782 {
1783
1784 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih))
1785 panic("died while creating vm swi ithread");
1786 }
1787 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr,
1788 NULL);
1789
1790 /*
1791 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
1792 * The data for this machine dependent, and the declarations are in machine
1793 * dependent code. The layout of intrnames and intrcnt however is machine
1794 * independent.
1795 *
1796 * We do not know the length of intrcnt and intrnames at compile time, so
1797 * calculate things at run time.
1798 */
1799 static int
1800 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
1801 {
1802 return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames,
1803 req));
1804 }
1805
1806 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
1807 NULL, 0, sysctl_intrnames, "", "Interrupt Names");
1808
1809 static int
1810 sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
1811 {
1812 return (sysctl_handle_opaque(oidp, intrcnt,
1813 (char *)eintrcnt - (char *)intrcnt, req));
1814 }
1815
1816 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
1817 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
1818
1819 #ifdef DDB
1820 /*
1821 * DDB command to dump the interrupt statistics.
1822 */
1823 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt)
1824 {
1825 u_long *i;
1826 char *cp;
1827
1828 cp = intrnames;
1829 for (i = intrcnt; i != eintrcnt && !db_pager_quit; i++) {
1830 if (*cp == '\0')
1831 break;
1832 if (*i != 0)
1833 db_printf("%s\t%lu\n", cp, *i);
1834 cp += strlen(cp) + 1;
1835 }
1836 }
1837 #endif
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