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("$FreeBSD$");
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_TTY;
134 break;
135 case INTR_TYPE_BIO:
136 pri = PI_DISK;
137 break;
138 case INTR_TYPE_NET:
139 pri = PI_NET;
140 break;
141 case INTR_TYPE_CAM:
142 pri = PI_DISK;
143 break;
144 case INTR_TYPE_AV:
145 pri = PI_AV;
146 break;
147 case INTR_TYPE_CLK:
148 pri = PI_REALTIME;
149 break;
150 case INTR_TYPE_MISC:
151 pri = PI_DULL; /* don't care */
152 break;
153 default:
154 /* We didn't specify an interrupt level. */
155 panic("intr_priority: no interrupt type in flags");
156 }
157
158 return pri;
159 }
160
161 /*
162 * Update an ithread based on the associated intr_event.
163 */
164 static void
165 ithread_update(struct intr_thread *ithd)
166 {
167 struct intr_event *ie;
168 struct thread *td;
169 u_char pri;
170
171 ie = ithd->it_event;
172 td = ithd->it_thread;
173
174 /* Determine the overall priority of this event. */
175 if (TAILQ_EMPTY(&ie->ie_handlers))
176 pri = PRI_MAX_ITHD;
177 else
178 pri = TAILQ_FIRST(&ie->ie_handlers)->ih_pri;
179
180 /* Update name and priority. */
181 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name));
182 #ifdef KTR
183 sched_clear_tdname(td);
184 #endif
185 thread_lock(td);
186 sched_prio(td, pri);
187 thread_unlock(td);
188 }
189
190 /*
191 * Regenerate the full name of an interrupt event and update its priority.
192 */
193 static void
194 intr_event_update(struct intr_event *ie)
195 {
196 struct intr_handler *ih;
197 char *last;
198 int missed, space;
199
200 /* Start off with no entropy and just the name of the event. */
201 mtx_assert(&ie->ie_lock, MA_OWNED);
202 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
203 ie->ie_flags &= ~IE_ENTROPY;
204 missed = 0;
205 space = 1;
206
207 /* Run through all the handlers updating values. */
208 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
209 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 <
210 sizeof(ie->ie_fullname)) {
211 strcat(ie->ie_fullname, " ");
212 strcat(ie->ie_fullname, ih->ih_name);
213 space = 0;
214 } else
215 missed++;
216 if (ih->ih_flags & IH_ENTROPY)
217 ie->ie_flags |= IE_ENTROPY;
218 }
219
220 /*
221 * If the handler names were too long, add +'s to indicate missing
222 * names. If we run out of room and still have +'s to add, change
223 * the last character from a + to a *.
224 */
225 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2];
226 while (missed-- > 0) {
227 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) {
228 if (*last == '+') {
229 *last = '*';
230 break;
231 } else
232 *last = '+';
233 } else if (space) {
234 strcat(ie->ie_fullname, " +");
235 space = 0;
236 } else
237 strcat(ie->ie_fullname, "+");
238 }
239
240 /*
241 * If this event has an ithread, update it's priority and
242 * name.
243 */
244 if (ie->ie_thread != NULL)
245 ithread_update(ie->ie_thread);
246 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname);
247 }
248
249 int
250 intr_event_create(struct intr_event **event, void *source, int flags, int irq,
251 void (*pre_ithread)(void *), void (*post_ithread)(void *),
252 void (*post_filter)(void *), int (*assign_cpu)(void *, u_char),
253 const char *fmt, ...)
254 {
255 struct intr_event *ie;
256 va_list ap;
257
258 /* The only valid flag during creation is IE_SOFT. */
259 if ((flags & ~IE_SOFT) != 0)
260 return (EINVAL);
261 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO);
262 ie->ie_source = source;
263 ie->ie_pre_ithread = pre_ithread;
264 ie->ie_post_ithread = post_ithread;
265 ie->ie_post_filter = post_filter;
266 ie->ie_assign_cpu = assign_cpu;
267 ie->ie_flags = flags;
268 ie->ie_irq = irq;
269 ie->ie_cpu = NOCPU;
270 TAILQ_INIT(&ie->ie_handlers);
271 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF);
272
273 va_start(ap, fmt);
274 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap);
275 va_end(ap);
276 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
277 mtx_lock(&event_lock);
278 TAILQ_INSERT_TAIL(&event_list, ie, ie_list);
279 mtx_unlock(&event_lock);
280 if (event != NULL)
281 *event = ie;
282 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name);
283 return (0);
284 }
285
286 /*
287 * Bind an interrupt event to the specified CPU. Note that not all
288 * platforms support binding an interrupt to a CPU. For those
289 * platforms this request will fail. For supported platforms, any
290 * associated ithreads as well as the primary interrupt context will
291 * be bound to the specificed CPU. Using a cpu id of NOCPU unbinds
292 * the interrupt event.
293 */
294 int
295 intr_event_bind(struct intr_event *ie, u_char cpu)
296 {
297 cpuset_t mask;
298 lwpid_t id;
299 int error;
300
301 /* Need a CPU to bind to. */
302 if (cpu != NOCPU && CPU_ABSENT(cpu))
303 return (EINVAL);
304
305 if (ie->ie_assign_cpu == NULL)
306 return (EOPNOTSUPP);
307
308 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR);
309 if (error)
310 return (error);
311
312 /*
313 * If we have any ithreads try to set their mask first to verify
314 * permissions, etc.
315 */
316 mtx_lock(&ie->ie_lock);
317 if (ie->ie_thread != NULL) {
318 CPU_ZERO(&mask);
319 if (cpu == NOCPU)
320 CPU_COPY(cpuset_root, &mask);
321 else
322 CPU_SET(cpu, &mask);
323 id = ie->ie_thread->it_thread->td_tid;
324 mtx_unlock(&ie->ie_lock);
325 error = cpuset_setthread(id, &mask);
326 if (error)
327 return (error);
328 } else
329 mtx_unlock(&ie->ie_lock);
330 error = ie->ie_assign_cpu(ie->ie_source, cpu);
331 if (error) {
332 mtx_lock(&ie->ie_lock);
333 if (ie->ie_thread != NULL) {
334 CPU_ZERO(&mask);
335 if (ie->ie_cpu == NOCPU)
336 CPU_COPY(cpuset_root, &mask);
337 else
338 CPU_SET(cpu, &mask);
339 id = ie->ie_thread->it_thread->td_tid;
340 mtx_unlock(&ie->ie_lock);
341 (void)cpuset_setthread(id, &mask);
342 } else
343 mtx_unlock(&ie->ie_lock);
344 return (error);
345 }
346
347 mtx_lock(&ie->ie_lock);
348 ie->ie_cpu = cpu;
349 mtx_unlock(&ie->ie_lock);
350
351 return (error);
352 }
353
354 static struct intr_event *
355 intr_lookup(int irq)
356 {
357 struct intr_event *ie;
358
359 mtx_lock(&event_lock);
360 TAILQ_FOREACH(ie, &event_list, ie_list)
361 if (ie->ie_irq == irq &&
362 (ie->ie_flags & IE_SOFT) == 0 &&
363 TAILQ_FIRST(&ie->ie_handlers) != NULL)
364 break;
365 mtx_unlock(&event_lock);
366 return (ie);
367 }
368
369 int
370 intr_setaffinity(int irq, void *m)
371 {
372 struct intr_event *ie;
373 cpuset_t *mask;
374 u_char cpu;
375 int n;
376
377 mask = m;
378 cpu = NOCPU;
379 /*
380 * If we're setting all cpus we can unbind. Otherwise make sure
381 * only one cpu is in the set.
382 */
383 if (CPU_CMP(cpuset_root, mask)) {
384 for (n = 0; n < CPU_SETSIZE; n++) {
385 if (!CPU_ISSET(n, mask))
386 continue;
387 if (cpu != NOCPU)
388 return (EINVAL);
389 cpu = (u_char)n;
390 }
391 }
392 ie = intr_lookup(irq);
393 if (ie == NULL)
394 return (ESRCH);
395 return (intr_event_bind(ie, cpu));
396 }
397
398 int
399 intr_getaffinity(int irq, void *m)
400 {
401 struct intr_event *ie;
402 cpuset_t *mask;
403
404 mask = m;
405 ie = intr_lookup(irq);
406 if (ie == NULL)
407 return (ESRCH);
408 CPU_ZERO(mask);
409 mtx_lock(&ie->ie_lock);
410 if (ie->ie_cpu == NOCPU)
411 CPU_COPY(cpuset_root, mask);
412 else
413 CPU_SET(ie->ie_cpu, mask);
414 mtx_unlock(&ie->ie_lock);
415 return (0);
416 }
417
418 int
419 intr_event_destroy(struct intr_event *ie)
420 {
421
422 mtx_lock(&event_lock);
423 mtx_lock(&ie->ie_lock);
424 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
425 mtx_unlock(&ie->ie_lock);
426 mtx_unlock(&event_lock);
427 return (EBUSY);
428 }
429 TAILQ_REMOVE(&event_list, ie, ie_list);
430 #ifndef notyet
431 if (ie->ie_thread != NULL) {
432 ithread_destroy(ie->ie_thread);
433 ie->ie_thread = NULL;
434 }
435 #endif
436 mtx_unlock(&ie->ie_lock);
437 mtx_unlock(&event_lock);
438 mtx_destroy(&ie->ie_lock);
439 free(ie, M_ITHREAD);
440 return (0);
441 }
442
443 #ifndef INTR_FILTER
444 static struct intr_thread *
445 ithread_create(const char *name)
446 {
447 struct intr_thread *ithd;
448 struct thread *td;
449 int error;
450
451 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
452
453 error = kproc_kthread_add(ithread_loop, ithd, &intrproc,
454 &td, RFSTOPPED | RFHIGHPID,
455 0, "intr", "%s", name);
456 if (error)
457 panic("kproc_create() failed with %d", error);
458 thread_lock(td);
459 sched_class(td, PRI_ITHD);
460 TD_SET_IWAIT(td);
461 thread_unlock(td);
462 td->td_pflags |= TDP_ITHREAD;
463 ithd->it_thread = td;
464 CTR2(KTR_INTR, "%s: created %s", __func__, name);
465 return (ithd);
466 }
467 #else
468 static struct intr_thread *
469 ithread_create(const char *name, struct intr_handler *ih)
470 {
471 struct intr_thread *ithd;
472 struct thread *td;
473 int error;
474
475 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
476
477 error = kproc_kthread_add(ithread_loop, ih, &intrproc,
478 &td, RFSTOPPED | RFHIGHPID,
479 0, "intr", "%s", name);
480 if (error)
481 panic("kproc_create() failed with %d", error);
482 thread_lock(td);
483 sched_class(td, PRI_ITHD);
484 TD_SET_IWAIT(td);
485 thread_unlock(td);
486 td->td_pflags |= TDP_ITHREAD;
487 ithd->it_thread = td;
488 CTR2(KTR_INTR, "%s: created %s", __func__, name);
489 return (ithd);
490 }
491 #endif
492
493 static void
494 ithread_destroy(struct intr_thread *ithread)
495 {
496 struct thread *td;
497
498 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name);
499 td = ithread->it_thread;
500 thread_lock(td);
501 ithread->it_flags |= IT_DEAD;
502 if (TD_AWAITING_INTR(td)) {
503 TD_CLR_IWAIT(td);
504 sched_add(td, SRQ_INTR);
505 }
506 thread_unlock(td);
507 }
508
509 #ifndef INTR_FILTER
510 int
511 intr_event_add_handler(struct intr_event *ie, const char *name,
512 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
513 enum intr_type flags, void **cookiep)
514 {
515 struct intr_handler *ih, *temp_ih;
516 struct intr_thread *it;
517
518 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
519 return (EINVAL);
520
521 /* Allocate and populate an interrupt handler structure. */
522 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
523 ih->ih_filter = filter;
524 ih->ih_handler = handler;
525 ih->ih_argument = arg;
526 strlcpy(ih->ih_name, name, sizeof(ih->ih_name));
527 ih->ih_event = ie;
528 ih->ih_pri = pri;
529 if (flags & INTR_EXCL)
530 ih->ih_flags = IH_EXCLUSIVE;
531 if (flags & INTR_MPSAFE)
532 ih->ih_flags |= IH_MPSAFE;
533 if (flags & INTR_ENTROPY)
534 ih->ih_flags |= IH_ENTROPY;
535
536 /* We can only have one exclusive handler in a event. */
537 mtx_lock(&ie->ie_lock);
538 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
539 if ((flags & INTR_EXCL) ||
540 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
541 mtx_unlock(&ie->ie_lock);
542 free(ih, M_ITHREAD);
543 return (EINVAL);
544 }
545 }
546
547 /* Add the new handler to the event in priority order. */
548 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
549 if (temp_ih->ih_pri > ih->ih_pri)
550 break;
551 }
552 if (temp_ih == NULL)
553 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
554 else
555 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
556 intr_event_update(ie);
557
558 /* Create a thread if we need one. */
559 while (ie->ie_thread == NULL && handler != NULL) {
560 if (ie->ie_flags & IE_ADDING_THREAD)
561 msleep(ie, &ie->ie_lock, 0, "ithread", 0);
562 else {
563 ie->ie_flags |= IE_ADDING_THREAD;
564 mtx_unlock(&ie->ie_lock);
565 it = ithread_create("intr: newborn");
566 mtx_lock(&ie->ie_lock);
567 ie->ie_flags &= ~IE_ADDING_THREAD;
568 ie->ie_thread = it;
569 it->it_event = ie;
570 ithread_update(it);
571 wakeup(ie);
572 }
573 }
574 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
575 ie->ie_name);
576 mtx_unlock(&ie->ie_lock);
577
578 if (cookiep != NULL)
579 *cookiep = ih;
580 return (0);
581 }
582 #else
583 int
584 intr_event_add_handler(struct intr_event *ie, const char *name,
585 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
586 enum intr_type flags, void **cookiep)
587 {
588 struct intr_handler *ih, *temp_ih;
589 struct intr_thread *it;
590
591 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
592 return (EINVAL);
593
594 /* Allocate and populate an interrupt handler structure. */
595 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
596 ih->ih_filter = filter;
597 ih->ih_handler = handler;
598 ih->ih_argument = arg;
599 strlcpy(ih->ih_name, name, sizeof(ih->ih_name));
600 ih->ih_event = ie;
601 ih->ih_pri = pri;
602 if (flags & INTR_EXCL)
603 ih->ih_flags = IH_EXCLUSIVE;
604 if (flags & INTR_MPSAFE)
605 ih->ih_flags |= IH_MPSAFE;
606 if (flags & INTR_ENTROPY)
607 ih->ih_flags |= IH_ENTROPY;
608
609 /* We can only have one exclusive handler in a event. */
610 mtx_lock(&ie->ie_lock);
611 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
612 if ((flags & INTR_EXCL) ||
613 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
614 mtx_unlock(&ie->ie_lock);
615 free(ih, M_ITHREAD);
616 return (EINVAL);
617 }
618 }
619
620 /* Add the new handler to the event in priority order. */
621 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
622 if (temp_ih->ih_pri > ih->ih_pri)
623 break;
624 }
625 if (temp_ih == NULL)
626 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
627 else
628 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
629 intr_event_update(ie);
630
631 /* For filtered handlers, create a private ithread to run on. */
632 if (filter != NULL && handler != NULL) {
633 mtx_unlock(&ie->ie_lock);
634 it = ithread_create("intr: newborn", ih);
635 mtx_lock(&ie->ie_lock);
636 it->it_event = ie;
637 ih->ih_thread = it;
638 ithread_update(it); // XXX - do we really need this?!?!?
639 } else { /* Create the global per-event thread if we need one. */
640 while (ie->ie_thread == NULL && handler != NULL) {
641 if (ie->ie_flags & IE_ADDING_THREAD)
642 msleep(ie, &ie->ie_lock, 0, "ithread", 0);
643 else {
644 ie->ie_flags |= IE_ADDING_THREAD;
645 mtx_unlock(&ie->ie_lock);
646 it = ithread_create("intr: newborn", ih);
647 mtx_lock(&ie->ie_lock);
648 ie->ie_flags &= ~IE_ADDING_THREAD;
649 ie->ie_thread = it;
650 it->it_event = ie;
651 ithread_update(it);
652 wakeup(ie);
653 }
654 }
655 }
656 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
657 ie->ie_name);
658 mtx_unlock(&ie->ie_lock);
659
660 if (cookiep != NULL)
661 *cookiep = ih;
662 return (0);
663 }
664 #endif
665
666 /*
667 * Append a description preceded by a ':' to the name of the specified
668 * interrupt handler.
669 */
670 int
671 intr_event_describe_handler(struct intr_event *ie, void *cookie,
672 const char *descr)
673 {
674 struct intr_handler *ih;
675 size_t space;
676 char *start;
677
678 mtx_lock(&ie->ie_lock);
679 #ifdef INVARIANTS
680 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
681 if (ih == cookie)
682 break;
683 }
684 if (ih == NULL) {
685 mtx_unlock(&ie->ie_lock);
686 panic("handler %p not found in interrupt event %p", cookie, ie);
687 }
688 #endif
689 ih = cookie;
690
691 /*
692 * Look for an existing description by checking for an
693 * existing ":". This assumes device names do not include
694 * colons. If one is found, prepare to insert the new
695 * description at that point. If one is not found, find the
696 * end of the name to use as the insertion point.
697 */
698 start = index(ih->ih_name, ':');
699 if (start == NULL)
700 start = index(ih->ih_name, 0);
701
702 /*
703 * See if there is enough remaining room in the string for the
704 * description + ":". The "- 1" leaves room for the trailing
705 * '\0'. The "+ 1" accounts for the colon.
706 */
707 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1;
708 if (strlen(descr) + 1 > space) {
709 mtx_unlock(&ie->ie_lock);
710 return (ENOSPC);
711 }
712
713 /* Append a colon followed by the description. */
714 *start = ':';
715 strcpy(start + 1, descr);
716 intr_event_update(ie);
717 mtx_unlock(&ie->ie_lock);
718 return (0);
719 }
720
721 /*
722 * Return the ie_source field from the intr_event an intr_handler is
723 * associated with.
724 */
725 void *
726 intr_handler_source(void *cookie)
727 {
728 struct intr_handler *ih;
729 struct intr_event *ie;
730
731 ih = (struct intr_handler *)cookie;
732 if (ih == NULL)
733 return (NULL);
734 ie = ih->ih_event;
735 KASSERT(ie != NULL,
736 ("interrupt handler \"%s\" has a NULL interrupt event",
737 ih->ih_name));
738 return (ie->ie_source);
739 }
740
741 #ifndef INTR_FILTER
742 int
743 intr_event_remove_handler(void *cookie)
744 {
745 struct intr_handler *handler = (struct intr_handler *)cookie;
746 struct intr_event *ie;
747 #ifdef INVARIANTS
748 struct intr_handler *ih;
749 #endif
750 #ifdef notyet
751 int dead;
752 #endif
753
754 if (handler == NULL)
755 return (EINVAL);
756 ie = handler->ih_event;
757 KASSERT(ie != NULL,
758 ("interrupt handler \"%s\" has a NULL interrupt event",
759 handler->ih_name));
760 mtx_lock(&ie->ie_lock);
761 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
762 ie->ie_name);
763 #ifdef INVARIANTS
764 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
765 if (ih == handler)
766 goto ok;
767 mtx_unlock(&ie->ie_lock);
768 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
769 ih->ih_name, ie->ie_name);
770 ok:
771 #endif
772 /*
773 * If there is no ithread, then just remove the handler and return.
774 * XXX: Note that an INTR_FAST handler might be running on another
775 * CPU!
776 */
777 if (ie->ie_thread == NULL) {
778 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
779 mtx_unlock(&ie->ie_lock);
780 free(handler, M_ITHREAD);
781 return (0);
782 }
783
784 /*
785 * If the interrupt thread is already running, then just mark this
786 * handler as being dead and let the ithread do the actual removal.
787 *
788 * During a cold boot while cold is set, msleep() does not sleep,
789 * so we have to remove the handler here rather than letting the
790 * thread do it.
791 */
792 thread_lock(ie->ie_thread->it_thread);
793 if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) {
794 handler->ih_flags |= IH_DEAD;
795
796 /*
797 * Ensure that the thread will process the handler list
798 * again and remove this handler if it has already passed
799 * it on the list.
800 */
801 ie->ie_thread->it_need = 1;
802 } else
803 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
804 thread_unlock(ie->ie_thread->it_thread);
805 while (handler->ih_flags & IH_DEAD)
806 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
807 intr_event_update(ie);
808 #ifdef notyet
809 /*
810 * XXX: This could be bad in the case of ppbus(8). Also, I think
811 * this could lead to races of stale data when servicing an
812 * interrupt.
813 */
814 dead = 1;
815 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
816 if (!(ih->ih_flags & IH_FAST)) {
817 dead = 0;
818 break;
819 }
820 }
821 if (dead) {
822 ithread_destroy(ie->ie_thread);
823 ie->ie_thread = NULL;
824 }
825 #endif
826 mtx_unlock(&ie->ie_lock);
827 free(handler, M_ITHREAD);
828 return (0);
829 }
830
831 static int
832 intr_event_schedule_thread(struct intr_event *ie)
833 {
834 struct intr_entropy entropy;
835 struct intr_thread *it;
836 struct thread *td;
837 struct thread *ctd;
838 struct proc *p;
839
840 /*
841 * If no ithread or no handlers, then we have a stray interrupt.
842 */
843 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) ||
844 ie->ie_thread == NULL)
845 return (EINVAL);
846
847 ctd = curthread;
848 it = ie->ie_thread;
849 td = it->it_thread;
850 p = td->td_proc;
851
852 /*
853 * If any of the handlers for this ithread claim to be good
854 * sources of entropy, then gather some.
855 */
856 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
857 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
858 p->p_pid, td->td_name);
859 entropy.event = (uintptr_t)ie;
860 entropy.td = ctd;
861 random_harvest(&entropy, sizeof(entropy), 2, 0,
862 RANDOM_INTERRUPT);
863 }
864
865 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
866
867 /*
868 * Set it_need to tell the thread to keep running if it is already
869 * running. Then, lock the thread and see if we actually need to
870 * put it on the runqueue.
871 */
872 it->it_need = 1;
873 thread_lock(td);
874 if (TD_AWAITING_INTR(td)) {
875 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
876 td->td_name);
877 TD_CLR_IWAIT(td);
878 sched_add(td, SRQ_INTR);
879 } else {
880 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
881 __func__, p->p_pid, td->td_name, it->it_need, td->td_state);
882 }
883 thread_unlock(td);
884
885 return (0);
886 }
887 #else
888 int
889 intr_event_remove_handler(void *cookie)
890 {
891 struct intr_handler *handler = (struct intr_handler *)cookie;
892 struct intr_event *ie;
893 struct intr_thread *it;
894 #ifdef INVARIANTS
895 struct intr_handler *ih;
896 #endif
897 #ifdef notyet
898 int dead;
899 #endif
900
901 if (handler == NULL)
902 return (EINVAL);
903 ie = handler->ih_event;
904 KASSERT(ie != NULL,
905 ("interrupt handler \"%s\" has a NULL interrupt event",
906 handler->ih_name));
907 mtx_lock(&ie->ie_lock);
908 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
909 ie->ie_name);
910 #ifdef INVARIANTS
911 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
912 if (ih == handler)
913 goto ok;
914 mtx_unlock(&ie->ie_lock);
915 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
916 ih->ih_name, ie->ie_name);
917 ok:
918 #endif
919 /*
920 * If there are no ithreads (per event and per handler), then
921 * just remove the handler and return.
922 * XXX: Note that an INTR_FAST handler might be running on another CPU!
923 */
924 if (ie->ie_thread == NULL && handler->ih_thread == NULL) {
925 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
926 mtx_unlock(&ie->ie_lock);
927 free(handler, M_ITHREAD);
928 return (0);
929 }
930
931 /* Private or global ithread? */
932 it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread;
933 /*
934 * If the interrupt thread is already running, then just mark this
935 * handler as being dead and let the ithread do the actual removal.
936 *
937 * During a cold boot while cold is set, msleep() does not sleep,
938 * so we have to remove the handler here rather than letting the
939 * thread do it.
940 */
941 thread_lock(it->it_thread);
942 if (!TD_AWAITING_INTR(it->it_thread) && !cold) {
943 handler->ih_flags |= IH_DEAD;
944
945 /*
946 * Ensure that the thread will process the handler list
947 * again and remove this handler if it has already passed
948 * it on the list.
949 */
950 it->it_need = 1;
951 } else
952 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
953 thread_unlock(it->it_thread);
954 while (handler->ih_flags & IH_DEAD)
955 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
956 /*
957 * At this point, the handler has been disconnected from the event,
958 * so we can kill the private ithread if any.
959 */
960 if (handler->ih_thread) {
961 ithread_destroy(handler->ih_thread);
962 handler->ih_thread = NULL;
963 }
964 intr_event_update(ie);
965 #ifdef notyet
966 /*
967 * XXX: This could be bad in the case of ppbus(8). Also, I think
968 * this could lead to races of stale data when servicing an
969 * interrupt.
970 */
971 dead = 1;
972 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
973 if (handler != NULL) {
974 dead = 0;
975 break;
976 }
977 }
978 if (dead) {
979 ithread_destroy(ie->ie_thread);
980 ie->ie_thread = NULL;
981 }
982 #endif
983 mtx_unlock(&ie->ie_lock);
984 free(handler, M_ITHREAD);
985 return (0);
986 }
987
988 static int
989 intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it)
990 {
991 struct intr_entropy entropy;
992 struct thread *td;
993 struct thread *ctd;
994 struct proc *p;
995
996 /*
997 * If no ithread or no handlers, then we have a stray interrupt.
998 */
999 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || it == NULL)
1000 return (EINVAL);
1001
1002 ctd = curthread;
1003 td = it->it_thread;
1004 p = td->td_proc;
1005
1006 /*
1007 * If any of the handlers for this ithread claim to be good
1008 * sources of entropy, then gather some.
1009 */
1010 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
1011 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
1012 p->p_pid, td->td_name);
1013 entropy.event = (uintptr_t)ie;
1014 entropy.td = ctd;
1015 random_harvest(&entropy, sizeof(entropy), 2, 0,
1016 RANDOM_INTERRUPT);
1017 }
1018
1019 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
1020
1021 /*
1022 * Set it_need to tell the thread to keep running if it is already
1023 * running. Then, lock the thread and see if we actually need to
1024 * put it on the runqueue.
1025 */
1026 it->it_need = 1;
1027 thread_lock(td);
1028 if (TD_AWAITING_INTR(td)) {
1029 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
1030 td->td_name);
1031 TD_CLR_IWAIT(td);
1032 sched_add(td, SRQ_INTR);
1033 } else {
1034 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
1035 __func__, p->p_pid, td->td_name, it->it_need, td->td_state);
1036 }
1037 thread_unlock(td);
1038
1039 return (0);
1040 }
1041 #endif
1042
1043 /*
1044 * Allow interrupt event binding for software interrupt handlers -- a no-op,
1045 * since interrupts are generated in software rather than being directed by
1046 * a PIC.
1047 */
1048 static int
1049 swi_assign_cpu(void *arg, u_char cpu)
1050 {
1051
1052 return (0);
1053 }
1054
1055 /*
1056 * Add a software interrupt handler to a specified event. If a given event
1057 * is not specified, then a new event is created.
1058 */
1059 int
1060 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler,
1061 void *arg, int pri, enum intr_type flags, void **cookiep)
1062 {
1063 struct thread *td;
1064 struct intr_event *ie;
1065 int error;
1066
1067 if (flags & INTR_ENTROPY)
1068 return (EINVAL);
1069
1070 ie = (eventp != NULL) ? *eventp : NULL;
1071
1072 if (ie != NULL) {
1073 if (!(ie->ie_flags & IE_SOFT))
1074 return (EINVAL);
1075 } else {
1076 error = intr_event_create(&ie, NULL, IE_SOFT, 0,
1077 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri);
1078 if (error)
1079 return (error);
1080 if (eventp != NULL)
1081 *eventp = ie;
1082 }
1083 error = intr_event_add_handler(ie, name, NULL, handler, arg,
1084 PI_SWI(pri), flags, cookiep);
1085 if (error)
1086 return (error);
1087 if (pri == SWI_CLOCK) {
1088 td = ie->ie_thread->it_thread;
1089 thread_lock(td);
1090 td->td_flags |= TDF_NOLOAD;
1091 thread_unlock(td);
1092 }
1093 return (0);
1094 }
1095
1096 /*
1097 * Schedule a software interrupt thread.
1098 */
1099 void
1100 swi_sched(void *cookie, int flags)
1101 {
1102 struct intr_handler *ih = (struct intr_handler *)cookie;
1103 struct intr_event *ie = ih->ih_event;
1104 int error;
1105
1106 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name,
1107 ih->ih_need);
1108
1109 /*
1110 * Set ih_need for this handler so that if the ithread is already
1111 * running it will execute this handler on the next pass. Otherwise,
1112 * it will execute it the next time it runs.
1113 */
1114 atomic_store_rel_int(&ih->ih_need, 1);
1115
1116 if (!(flags & SWI_DELAY)) {
1117 PCPU_INC(cnt.v_soft);
1118 #ifdef INTR_FILTER
1119 error = intr_event_schedule_thread(ie, ie->ie_thread);
1120 #else
1121 error = intr_event_schedule_thread(ie);
1122 #endif
1123 KASSERT(error == 0, ("stray software interrupt"));
1124 }
1125 }
1126
1127 /*
1128 * Remove a software interrupt handler. Currently this code does not
1129 * remove the associated interrupt event if it becomes empty. Calling code
1130 * may do so manually via intr_event_destroy(), but that's not really
1131 * an optimal interface.
1132 */
1133 int
1134 swi_remove(void *cookie)
1135 {
1136
1137 return (intr_event_remove_handler(cookie));
1138 }
1139
1140 #ifdef INTR_FILTER
1141 static void
1142 priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih)
1143 {
1144 struct intr_event *ie;
1145
1146 ie = ih->ih_event;
1147 /*
1148 * If this handler is marked for death, remove it from
1149 * the list of handlers and wake up the sleeper.
1150 */
1151 if (ih->ih_flags & IH_DEAD) {
1152 mtx_lock(&ie->ie_lock);
1153 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
1154 ih->ih_flags &= ~IH_DEAD;
1155 wakeup(ih);
1156 mtx_unlock(&ie->ie_lock);
1157 return;
1158 }
1159
1160 /* Execute this handler. */
1161 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1162 __func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument,
1163 ih->ih_name, ih->ih_flags);
1164
1165 if (!(ih->ih_flags & IH_MPSAFE))
1166 mtx_lock(&Giant);
1167 ih->ih_handler(ih->ih_argument);
1168 if (!(ih->ih_flags & IH_MPSAFE))
1169 mtx_unlock(&Giant);
1170 }
1171 #endif
1172
1173 /*
1174 * This is a public function for use by drivers that mux interrupt
1175 * handlers for child devices from their interrupt handler.
1176 */
1177 void
1178 intr_event_execute_handlers(struct proc *p, struct intr_event *ie)
1179 {
1180 struct intr_handler *ih, *ihn;
1181
1182 TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) {
1183 /*
1184 * If this handler is marked for death, remove it from
1185 * the list of handlers and wake up the sleeper.
1186 */
1187 if (ih->ih_flags & IH_DEAD) {
1188 mtx_lock(&ie->ie_lock);
1189 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
1190 ih->ih_flags &= ~IH_DEAD;
1191 wakeup(ih);
1192 mtx_unlock(&ie->ie_lock);
1193 continue;
1194 }
1195
1196 /* Skip filter only handlers */
1197 if (ih->ih_handler == NULL)
1198 continue;
1199
1200 /*
1201 * For software interrupt threads, we only execute
1202 * handlers that have their need flag set. Hardware
1203 * interrupt threads always invoke all of their handlers.
1204 */
1205 if (ie->ie_flags & IE_SOFT) {
1206 if (!ih->ih_need)
1207 continue;
1208 else
1209 atomic_store_rel_int(&ih->ih_need, 0);
1210 }
1211
1212 /* Execute this handler. */
1213 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1214 __func__, p->p_pid, (void *)ih->ih_handler,
1215 ih->ih_argument, ih->ih_name, ih->ih_flags);
1216
1217 if (!(ih->ih_flags & IH_MPSAFE))
1218 mtx_lock(&Giant);
1219 ih->ih_handler(ih->ih_argument);
1220 if (!(ih->ih_flags & IH_MPSAFE))
1221 mtx_unlock(&Giant);
1222 }
1223 }
1224
1225 static void
1226 ithread_execute_handlers(struct proc *p, struct intr_event *ie)
1227 {
1228
1229 /* Interrupt handlers should not sleep. */
1230 if (!(ie->ie_flags & IE_SOFT))
1231 THREAD_NO_SLEEPING();
1232 intr_event_execute_handlers(p, ie);
1233 if (!(ie->ie_flags & IE_SOFT))
1234 THREAD_SLEEPING_OK();
1235
1236 /*
1237 * Interrupt storm handling:
1238 *
1239 * If this interrupt source is currently storming, then throttle
1240 * it to only fire the handler once per clock tick.
1241 *
1242 * If this interrupt source is not currently storming, but the
1243 * number of back to back interrupts exceeds the storm threshold,
1244 * then enter storming mode.
1245 */
1246 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold &&
1247 !(ie->ie_flags & IE_SOFT)) {
1248 /* Report the message only once every second. */
1249 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) {
1250 printf(
1251 "interrupt storm detected on \"%s\"; throttling interrupt source\n",
1252 ie->ie_name);
1253 }
1254 pause("istorm", 1);
1255 } else
1256 ie->ie_count++;
1257
1258 /*
1259 * Now that all the handlers have had a chance to run, reenable
1260 * the interrupt source.
1261 */
1262 if (ie->ie_post_ithread != NULL)
1263 ie->ie_post_ithread(ie->ie_source);
1264 }
1265
1266 #ifndef INTR_FILTER
1267 /*
1268 * This is the main code for interrupt threads.
1269 */
1270 static void
1271 ithread_loop(void *arg)
1272 {
1273 struct intr_thread *ithd;
1274 struct intr_event *ie;
1275 struct thread *td;
1276 struct proc *p;
1277
1278 td = curthread;
1279 p = td->td_proc;
1280 ithd = (struct intr_thread *)arg;
1281 KASSERT(ithd->it_thread == td,
1282 ("%s: ithread and proc linkage out of sync", __func__));
1283 ie = ithd->it_event;
1284 ie->ie_count = 0;
1285
1286 /*
1287 * As long as we have interrupts outstanding, go through the
1288 * list of handlers, giving each one a go at it.
1289 */
1290 for (;;) {
1291 /*
1292 * If we are an orphaned thread, then just die.
1293 */
1294 if (ithd->it_flags & IT_DEAD) {
1295 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1296 p->p_pid, td->td_name);
1297 free(ithd, M_ITHREAD);
1298 kthread_exit();
1299 }
1300
1301 /*
1302 * Service interrupts. If another interrupt arrives while
1303 * we are running, it will set it_need to note that we
1304 * should make another pass.
1305 */
1306 while (ithd->it_need) {
1307 /*
1308 * This might need a full read and write barrier
1309 * to make sure that this write posts before any
1310 * of the memory or device accesses in the
1311 * handlers.
1312 */
1313 atomic_store_rel_int(&ithd->it_need, 0);
1314 ithread_execute_handlers(p, ie);
1315 }
1316 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1317 mtx_assert(&Giant, MA_NOTOWNED);
1318
1319 /*
1320 * Processed all our interrupts. Now get the sched
1321 * lock. This may take a while and it_need may get
1322 * set again, so we have to check it again.
1323 */
1324 thread_lock(td);
1325 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) {
1326 TD_SET_IWAIT(td);
1327 ie->ie_count = 0;
1328 mi_switch(SW_VOL | SWT_IWAIT, NULL);
1329 }
1330 thread_unlock(td);
1331 }
1332 }
1333
1334 /*
1335 * Main interrupt handling body.
1336 *
1337 * Input:
1338 * o ie: the event connected to this interrupt.
1339 * o frame: some archs (i.e. i386) pass a frame to some.
1340 * handlers as their main argument.
1341 * Return value:
1342 * o 0: everything ok.
1343 * o EINVAL: stray interrupt.
1344 */
1345 int
1346 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1347 {
1348 struct intr_handler *ih;
1349 struct thread *td;
1350 int error, ret, thread;
1351
1352 td = curthread;
1353
1354 /* An interrupt with no event or handlers is a stray interrupt. */
1355 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
1356 return (EINVAL);
1357
1358 /*
1359 * Execute fast interrupt handlers directly.
1360 * To support clock handlers, if a handler registers
1361 * with a NULL argument, then we pass it a pointer to
1362 * a trapframe as its argument.
1363 */
1364 td->td_intr_nesting_level++;
1365 thread = 0;
1366 ret = 0;
1367 critical_enter();
1368 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1369 if (ih->ih_filter == NULL) {
1370 thread = 1;
1371 continue;
1372 }
1373 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__,
1374 ih->ih_filter, ih->ih_argument == NULL ? frame :
1375 ih->ih_argument, ih->ih_name);
1376 if (ih->ih_argument == NULL)
1377 ret = ih->ih_filter(frame);
1378 else
1379 ret = ih->ih_filter(ih->ih_argument);
1380 KASSERT(ret == FILTER_STRAY ||
1381 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 &&
1382 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0),
1383 ("%s: incorrect return value %#x from %s", __func__, ret,
1384 ih->ih_name));
1385
1386 /*
1387 * Wrapper handler special handling:
1388 *
1389 * in some particular cases (like pccard and pccbb),
1390 * the _real_ device handler is wrapped in a couple of
1391 * functions - a filter wrapper and an ithread wrapper.
1392 * In this case (and just in this case), the filter wrapper
1393 * could ask the system to schedule the ithread and mask
1394 * the interrupt source if the wrapped handler is composed
1395 * of just an ithread handler.
1396 *
1397 * TODO: write a generic wrapper to avoid people rolling
1398 * their own
1399 */
1400 if (!thread) {
1401 if (ret == FILTER_SCHEDULE_THREAD)
1402 thread = 1;
1403 }
1404 }
1405
1406 if (thread) {
1407 if (ie->ie_pre_ithread != NULL)
1408 ie->ie_pre_ithread(ie->ie_source);
1409 } else {
1410 if (ie->ie_post_filter != NULL)
1411 ie->ie_post_filter(ie->ie_source);
1412 }
1413
1414 /* Schedule the ithread if needed. */
1415 if (thread) {
1416 error = intr_event_schedule_thread(ie);
1417 #ifndef XEN
1418 KASSERT(error == 0, ("bad stray interrupt"));
1419 #else
1420 if (error != 0)
1421 log(LOG_WARNING, "bad stray interrupt");
1422 #endif
1423 }
1424 critical_exit();
1425 td->td_intr_nesting_level--;
1426 return (0);
1427 }
1428 #else
1429 /*
1430 * This is the main code for interrupt threads.
1431 */
1432 static void
1433 ithread_loop(void *arg)
1434 {
1435 struct intr_thread *ithd;
1436 struct intr_handler *ih;
1437 struct intr_event *ie;
1438 struct thread *td;
1439 struct proc *p;
1440 int priv;
1441
1442 td = curthread;
1443 p = td->td_proc;
1444 ih = (struct intr_handler *)arg;
1445 priv = (ih->ih_thread != NULL) ? 1 : 0;
1446 ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread;
1447 KASSERT(ithd->it_thread == td,
1448 ("%s: ithread and proc linkage out of sync", __func__));
1449 ie = ithd->it_event;
1450 ie->ie_count = 0;
1451
1452 /*
1453 * As long as we have interrupts outstanding, go through the
1454 * list of handlers, giving each one a go at it.
1455 */
1456 for (;;) {
1457 /*
1458 * If we are an orphaned thread, then just die.
1459 */
1460 if (ithd->it_flags & IT_DEAD) {
1461 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1462 p->p_pid, td->td_name);
1463 free(ithd, M_ITHREAD);
1464 kthread_exit();
1465 }
1466
1467 /*
1468 * Service interrupts. If another interrupt arrives while
1469 * we are running, it will set it_need to note that we
1470 * should make another pass.
1471 */
1472 while (ithd->it_need) {
1473 /*
1474 * This might need a full read and write barrier
1475 * to make sure that this write posts before any
1476 * of the memory or device accesses in the
1477 * handlers.
1478 */
1479 atomic_store_rel_int(&ithd->it_need, 0);
1480 if (priv)
1481 priv_ithread_execute_handler(p, ih);
1482 else
1483 ithread_execute_handlers(p, ie);
1484 }
1485 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1486 mtx_assert(&Giant, MA_NOTOWNED);
1487
1488 /*
1489 * Processed all our interrupts. Now get the sched
1490 * lock. This may take a while and it_need may get
1491 * set again, so we have to check it again.
1492 */
1493 thread_lock(td);
1494 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) {
1495 TD_SET_IWAIT(td);
1496 ie->ie_count = 0;
1497 mi_switch(SW_VOL | SWT_IWAIT, NULL);
1498 }
1499 thread_unlock(td);
1500 }
1501 }
1502
1503 /*
1504 * Main loop for interrupt filter.
1505 *
1506 * Some architectures (i386, amd64 and arm) require the optional frame
1507 * parameter, and use it as the main argument for fast handler execution
1508 * when ih_argument == NULL.
1509 *
1510 * Return value:
1511 * o FILTER_STRAY: No filter recognized the event, and no
1512 * filter-less handler is registered on this
1513 * line.
1514 * o FILTER_HANDLED: A filter claimed the event and served it.
1515 * o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at
1516 * least one filter-less handler on this line.
1517 * o FILTER_HANDLED |
1518 * FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for
1519 * scheduling the per-handler ithread.
1520 *
1521 * In case an ithread has to be scheduled, in *ithd there will be a
1522 * pointer to a struct intr_thread containing the thread to be
1523 * scheduled.
1524 */
1525
1526 static int
1527 intr_filter_loop(struct intr_event *ie, struct trapframe *frame,
1528 struct intr_thread **ithd)
1529 {
1530 struct intr_handler *ih;
1531 void *arg;
1532 int ret, thread_only;
1533
1534 ret = 0;
1535 thread_only = 0;
1536 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1537 /*
1538 * Execute fast interrupt handlers directly.
1539 * To support clock handlers, if a handler registers
1540 * with a NULL argument, then we pass it a pointer to
1541 * a trapframe as its argument.
1542 */
1543 arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument);
1544
1545 CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__,
1546 ih->ih_filter, ih->ih_handler, arg, ih->ih_name);
1547
1548 if (ih->ih_filter != NULL)
1549 ret = ih->ih_filter(arg);
1550 else {
1551 thread_only = 1;
1552 continue;
1553 }
1554 KASSERT(ret == FILTER_STRAY ||
1555 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 &&
1556 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0),
1557 ("%s: incorrect return value %#x from %s", __func__, ret,
1558 ih->ih_name));
1559 if (ret & FILTER_STRAY)
1560 continue;
1561 else {
1562 *ithd = ih->ih_thread;
1563 return (ret);
1564 }
1565 }
1566
1567 /*
1568 * No filters handled the interrupt and we have at least
1569 * one handler without a filter. In this case, we schedule
1570 * all of the filter-less handlers to run in the ithread.
1571 */
1572 if (thread_only) {
1573 *ithd = ie->ie_thread;
1574 return (FILTER_SCHEDULE_THREAD);
1575 }
1576 return (FILTER_STRAY);
1577 }
1578
1579 /*
1580 * Main interrupt handling body.
1581 *
1582 * Input:
1583 * o ie: the event connected to this interrupt.
1584 * o frame: some archs (i.e. i386) pass a frame to some.
1585 * handlers as their main argument.
1586 * Return value:
1587 * o 0: everything ok.
1588 * o EINVAL: stray interrupt.
1589 */
1590 int
1591 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1592 {
1593 struct intr_thread *ithd;
1594 struct thread *td;
1595 int thread;
1596
1597 ithd = NULL;
1598 td = curthread;
1599
1600 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
1601 return (EINVAL);
1602
1603 td->td_intr_nesting_level++;
1604 thread = 0;
1605 critical_enter();
1606 thread = intr_filter_loop(ie, frame, &ithd);
1607 if (thread & FILTER_HANDLED) {
1608 if (ie->ie_post_filter != NULL)
1609 ie->ie_post_filter(ie->ie_source);
1610 } else {
1611 if (ie->ie_pre_ithread != NULL)
1612 ie->ie_pre_ithread(ie->ie_source);
1613 }
1614 critical_exit();
1615
1616 /* Interrupt storm logic */
1617 if (thread & FILTER_STRAY) {
1618 ie->ie_count++;
1619 if (ie->ie_count < intr_storm_threshold)
1620 printf("Interrupt stray detection not present\n");
1621 }
1622
1623 /* Schedule an ithread if needed. */
1624 if (thread & FILTER_SCHEDULE_THREAD) {
1625 if (intr_event_schedule_thread(ie, ithd) != 0)
1626 panic("%s: impossible stray interrupt", __func__);
1627 }
1628 td->td_intr_nesting_level--;
1629 return (0);
1630 }
1631 #endif
1632
1633 #ifdef DDB
1634 /*
1635 * Dump details about an interrupt handler
1636 */
1637 static void
1638 db_dump_intrhand(struct intr_handler *ih)
1639 {
1640 int comma;
1641
1642 db_printf("\t%-10s ", ih->ih_name);
1643 switch (ih->ih_pri) {
1644 case PI_REALTIME:
1645 db_printf("CLK ");
1646 break;
1647 case PI_AV:
1648 db_printf("AV ");
1649 break;
1650 case PI_TTY:
1651 db_printf("TTY ");
1652 break;
1653 case PI_NET:
1654 db_printf("NET ");
1655 break;
1656 case PI_DISK:
1657 db_printf("DISK");
1658 break;
1659 case PI_DULL:
1660 db_printf("DULL");
1661 break;
1662 default:
1663 if (ih->ih_pri >= PI_SOFT)
1664 db_printf("SWI ");
1665 else
1666 db_printf("%4u", ih->ih_pri);
1667 break;
1668 }
1669 db_printf(" ");
1670 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC);
1671 db_printf("(%p)", ih->ih_argument);
1672 if (ih->ih_need ||
1673 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD |
1674 IH_MPSAFE)) != 0) {
1675 db_printf(" {");
1676 comma = 0;
1677 if (ih->ih_flags & IH_EXCLUSIVE) {
1678 if (comma)
1679 db_printf(", ");
1680 db_printf("EXCL");
1681 comma = 1;
1682 }
1683 if (ih->ih_flags & IH_ENTROPY) {
1684 if (comma)
1685 db_printf(", ");
1686 db_printf("ENTROPY");
1687 comma = 1;
1688 }
1689 if (ih->ih_flags & IH_DEAD) {
1690 if (comma)
1691 db_printf(", ");
1692 db_printf("DEAD");
1693 comma = 1;
1694 }
1695 if (ih->ih_flags & IH_MPSAFE) {
1696 if (comma)
1697 db_printf(", ");
1698 db_printf("MPSAFE");
1699 comma = 1;
1700 }
1701 if (ih->ih_need) {
1702 if (comma)
1703 db_printf(", ");
1704 db_printf("NEED");
1705 }
1706 db_printf("}");
1707 }
1708 db_printf("\n");
1709 }
1710
1711 /*
1712 * Dump details about a event.
1713 */
1714 void
1715 db_dump_intr_event(struct intr_event *ie, int handlers)
1716 {
1717 struct intr_handler *ih;
1718 struct intr_thread *it;
1719 int comma;
1720
1721 db_printf("%s ", ie->ie_fullname);
1722 it = ie->ie_thread;
1723 if (it != NULL)
1724 db_printf("(pid %d)", it->it_thread->td_proc->p_pid);
1725 else
1726 db_printf("(no thread)");
1727 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 ||
1728 (it != NULL && it->it_need)) {
1729 db_printf(" {");
1730 comma = 0;
1731 if (ie->ie_flags & IE_SOFT) {
1732 db_printf("SOFT");
1733 comma = 1;
1734 }
1735 if (ie->ie_flags & IE_ENTROPY) {
1736 if (comma)
1737 db_printf(", ");
1738 db_printf("ENTROPY");
1739 comma = 1;
1740 }
1741 if (ie->ie_flags & IE_ADDING_THREAD) {
1742 if (comma)
1743 db_printf(", ");
1744 db_printf("ADDING_THREAD");
1745 comma = 1;
1746 }
1747 if (it != NULL && it->it_need) {
1748 if (comma)
1749 db_printf(", ");
1750 db_printf("NEED");
1751 }
1752 db_printf("}");
1753 }
1754 db_printf("\n");
1755
1756 if (handlers)
1757 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
1758 db_dump_intrhand(ih);
1759 }
1760
1761 /*
1762 * Dump data about interrupt handlers
1763 */
1764 DB_SHOW_COMMAND(intr, db_show_intr)
1765 {
1766 struct intr_event *ie;
1767 int all, verbose;
1768
1769 verbose = index(modif, 'v') != NULL;
1770 all = index(modif, 'a') != NULL;
1771 TAILQ_FOREACH(ie, &event_list, ie_list) {
1772 if (!all && TAILQ_EMPTY(&ie->ie_handlers))
1773 continue;
1774 db_dump_intr_event(ie, verbose);
1775 if (db_pager_quit)
1776 break;
1777 }
1778 }
1779 #endif /* DDB */
1780
1781 /*
1782 * Start standard software interrupt threads
1783 */
1784 static void
1785 start_softintr(void *dummy)
1786 {
1787
1788 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih))
1789 panic("died while creating vm swi ithread");
1790 }
1791 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr,
1792 NULL);
1793
1794 /*
1795 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
1796 * The data for this machine dependent, and the declarations are in machine
1797 * dependent code. The layout of intrnames and intrcnt however is machine
1798 * independent.
1799 *
1800 * We do not know the length of intrcnt and intrnames at compile time, so
1801 * calculate things at run time.
1802 */
1803 static int
1804 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
1805 {
1806 return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames,
1807 req));
1808 }
1809
1810 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
1811 NULL, 0, sysctl_intrnames, "", "Interrupt Names");
1812
1813 static int
1814 sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
1815 {
1816 return (sysctl_handle_opaque(oidp, intrcnt,
1817 (char *)eintrcnt - (char *)intrcnt, req));
1818 }
1819
1820 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
1821 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
1822
1823 #ifdef DDB
1824 /*
1825 * DDB command to dump the interrupt statistics.
1826 */
1827 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt)
1828 {
1829 u_long *i;
1830 char *cp;
1831
1832 cp = intrnames;
1833 for (i = intrcnt; i != eintrcnt && !db_pager_quit; i++) {
1834 if (*cp == '\0')
1835 break;
1836 if (*i != 0)
1837 db_printf("%s\t%lu\n", cp, *i);
1838 cp += strlen(cp) + 1;
1839 }
1840 }
1841 #endif
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