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 #include "opt_kstack_usage_prof.h"
32
33 #include <sys/param.h>
34 #include <sys/bus.h>
35 #include <sys/conf.h>
36 #include <sys/cpuset.h>
37 #include <sys/rtprio.h>
38 #include <sys/systm.h>
39 #include <sys/interrupt.h>
40 #include <sys/kernel.h>
41 #include <sys/kthread.h>
42 #include <sys/ktr.h>
43 #include <sys/limits.h>
44 #include <sys/lock.h>
45 #include <sys/malloc.h>
46 #include <sys/mutex.h>
47 #include <sys/priv.h>
48 #include <sys/proc.h>
49 #include <sys/random.h>
50 #include <sys/resourcevar.h>
51 #include <sys/sched.h>
52 #include <sys/smp.h>
53 #include <sys/sysctl.h>
54 #include <sys/syslog.h>
55 #include <sys/unistd.h>
56 #include <sys/vmmeter.h>
57 #include <machine/atomic.h>
58 #include <machine/cpu.h>
59 #include <machine/md_var.h>
60 #include <machine/stdarg.h>
61 #ifdef DDB
62 #include <ddb/ddb.h>
63 #include <ddb/db_sym.h>
64 #endif
65
66 /*
67 * Describe an interrupt thread. There is one of these per interrupt event.
68 */
69 struct intr_thread {
70 struct intr_event *it_event;
71 struct thread *it_thread; /* Kernel thread. */
72 int it_flags; /* (j) IT_* flags. */
73 int it_need; /* Needs service. */
74 };
75
76 /* Interrupt thread flags kept in it_flags */
77 #define IT_DEAD 0x000001 /* Thread is waiting to exit. */
78 #define IT_WAIT 0x000002 /* Thread is waiting for completion. */
79
80 struct intr_entropy {
81 struct thread *td;
82 uintptr_t event;
83 };
84
85 struct intr_event *clk_intr_event;
86 struct intr_event *tty_intr_event;
87 void *vm_ih;
88 struct proc *intrproc;
89
90 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads");
91
92 static int intr_storm_threshold = 1000;
93 TUNABLE_INT("hw.intr_storm_threshold", &intr_storm_threshold);
94 SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RW,
95 &intr_storm_threshold, 0,
96 "Number of consecutive interrupts before storm protection is enabled");
97 static TAILQ_HEAD(, intr_event) event_list =
98 TAILQ_HEAD_INITIALIZER(event_list);
99 static struct mtx event_lock;
100 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF);
101
102 static void intr_event_update(struct intr_event *ie);
103 #ifdef INTR_FILTER
104 static int intr_event_schedule_thread(struct intr_event *ie,
105 struct intr_thread *ithd);
106 static int intr_filter_loop(struct intr_event *ie,
107 struct trapframe *frame, struct intr_thread **ithd);
108 static struct intr_thread *ithread_create(const char *name,
109 struct intr_handler *ih);
110 #else
111 static int intr_event_schedule_thread(struct intr_event *ie);
112 static struct intr_thread *ithread_create(const char *name);
113 #endif
114 static void ithread_destroy(struct intr_thread *ithread);
115 static void ithread_execute_handlers(struct proc *p,
116 struct intr_event *ie);
117 #ifdef INTR_FILTER
118 static void priv_ithread_execute_handler(struct proc *p,
119 struct intr_handler *ih);
120 #endif
121 static void ithread_loop(void *);
122 static void ithread_update(struct intr_thread *ithd);
123 static void start_softintr(void *);
124
125 /* Map an interrupt type to an ithread priority. */
126 u_char
intr_priority(enum intr_type flags)127 intr_priority(enum intr_type flags)
128 {
129 u_char pri;
130
131 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET |
132 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV);
133 switch (flags) {
134 case INTR_TYPE_TTY:
135 pri = PI_TTY;
136 break;
137 case INTR_TYPE_BIO:
138 pri = PI_DISK;
139 break;
140 case INTR_TYPE_NET:
141 pri = PI_NET;
142 break;
143 case INTR_TYPE_CAM:
144 pri = PI_DISK;
145 break;
146 case INTR_TYPE_AV:
147 pri = PI_AV;
148 break;
149 case INTR_TYPE_CLK:
150 pri = PI_REALTIME;
151 break;
152 case INTR_TYPE_MISC:
153 pri = PI_DULL; /* don't care */
154 break;
155 default:
156 /* We didn't specify an interrupt level. */
157 panic("intr_priority: no interrupt type in flags");
158 }
159
160 return pri;
161 }
162
163 /*
164 * Update an ithread based on the associated intr_event.
165 */
166 static void
ithread_update(struct intr_thread * ithd)167 ithread_update(struct intr_thread *ithd)
168 {
169 struct intr_event *ie;
170 struct thread *td;
171 u_char pri;
172
173 ie = ithd->it_event;
174 td = ithd->it_thread;
175
176 /* Determine the overall priority of this event. */
177 if (TAILQ_EMPTY(&ie->ie_handlers))
178 pri = PRI_MAX_ITHD;
179 else
180 pri = TAILQ_FIRST(&ie->ie_handlers)->ih_pri;
181
182 /* Update name and priority. */
183 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name));
184 #ifdef KTR
185 sched_clear_tdname(td);
186 #endif
187 thread_lock(td);
188 sched_prio(td, pri);
189 thread_unlock(td);
190 }
191
192 /*
193 * Regenerate the full name of an interrupt event and update its priority.
194 */
195 static void
intr_event_update(struct intr_event * ie)196 intr_event_update(struct intr_event *ie)
197 {
198 struct intr_handler *ih;
199 char *last;
200 int missed, space;
201
202 /* Start off with no entropy and just the name of the event. */
203 mtx_assert(&ie->ie_lock, MA_OWNED);
204 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
205 ie->ie_flags &= ~IE_ENTROPY;
206 missed = 0;
207 space = 1;
208
209 /* Run through all the handlers updating values. */
210 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
211 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 <
212 sizeof(ie->ie_fullname)) {
213 strcat(ie->ie_fullname, " ");
214 strcat(ie->ie_fullname, ih->ih_name);
215 space = 0;
216 } else
217 missed++;
218 if (ih->ih_flags & IH_ENTROPY)
219 ie->ie_flags |= IE_ENTROPY;
220 }
221
222 /*
223 * If the handler names were too long, add +'s to indicate missing
224 * names. If we run out of room and still have +'s to add, change
225 * the last character from a + to a *.
226 */
227 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2];
228 while (missed-- > 0) {
229 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) {
230 if (*last == '+') {
231 *last = '*';
232 break;
233 } else
234 *last = '+';
235 } else if (space) {
236 strcat(ie->ie_fullname, " +");
237 space = 0;
238 } else
239 strcat(ie->ie_fullname, "+");
240 }
241
242 /*
243 * If this event has an ithread, update it's priority and
244 * name.
245 */
246 if (ie->ie_thread != NULL)
247 ithread_update(ie->ie_thread);
248 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname);
249 }
250
251 int
intr_event_create(struct intr_event ** event,void * source,int flags,int irq,void (* pre_ithread)(void *),void (* post_ithread)(void *),void (* post_filter)(void *),int (* assign_cpu)(void *,u_char),const char * fmt,...)252 intr_event_create(struct intr_event **event, void *source, int flags, int irq,
253 void (*pre_ithread)(void *), void (*post_ithread)(void *),
254 void (*post_filter)(void *), int (*assign_cpu)(void *, u_char),
255 const char *fmt, ...)
256 {
257 struct intr_event *ie;
258 va_list ap;
259
260 /* The only valid flag during creation is IE_SOFT. */
261 if ((flags & ~IE_SOFT) != 0)
262 return (EINVAL);
263 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO);
264 ie->ie_source = source;
265 ie->ie_pre_ithread = pre_ithread;
266 ie->ie_post_ithread = post_ithread;
267 ie->ie_post_filter = post_filter;
268 ie->ie_assign_cpu = assign_cpu;
269 ie->ie_flags = flags;
270 ie->ie_irq = irq;
271 ie->ie_cpu = NOCPU;
272 TAILQ_INIT(&ie->ie_handlers);
273 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF);
274
275 va_start(ap, fmt);
276 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap);
277 va_end(ap);
278 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname));
279 mtx_lock(&event_lock);
280 TAILQ_INSERT_TAIL(&event_list, ie, ie_list);
281 mtx_unlock(&event_lock);
282 if (event != NULL)
283 *event = ie;
284 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name);
285 return (0);
286 }
287
288 /*
289 * Bind an interrupt event to the specified CPU. Note that not all
290 * platforms support binding an interrupt to a CPU. For those
291 * platforms this request will fail. For supported platforms, any
292 * associated ithreads as well as the primary interrupt context will
293 * be bound to the specificed CPU. Using a cpu id of NOCPU unbinds
294 * the interrupt event.
295 */
296 int
intr_event_bind(struct intr_event * ie,u_char cpu)297 intr_event_bind(struct intr_event *ie, u_char cpu)
298 {
299 cpuset_t mask;
300 lwpid_t id;
301 int error;
302
303 /* Need a CPU to bind to. */
304 if (cpu != NOCPU && CPU_ABSENT(cpu))
305 return (EINVAL);
306
307 if (ie->ie_assign_cpu == NULL)
308 return (EOPNOTSUPP);
309
310 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR);
311 if (error)
312 return (error);
313
314 /*
315 * If we have any ithreads try to set their mask first to verify
316 * permissions, etc.
317 */
318 mtx_lock(&ie->ie_lock);
319 if (ie->ie_thread != NULL) {
320 CPU_ZERO(&mask);
321 if (cpu == NOCPU)
322 CPU_COPY(cpuset_root, &mask);
323 else
324 CPU_SET(cpu, &mask);
325 id = ie->ie_thread->it_thread->td_tid;
326 mtx_unlock(&ie->ie_lock);
327 error = cpuset_setthread(id, &mask);
328 if (error)
329 return (error);
330 } else
331 mtx_unlock(&ie->ie_lock);
332 error = ie->ie_assign_cpu(ie->ie_source, cpu);
333 if (error) {
334 mtx_lock(&ie->ie_lock);
335 if (ie->ie_thread != NULL) {
336 CPU_ZERO(&mask);
337 if (ie->ie_cpu == NOCPU)
338 CPU_COPY(cpuset_root, &mask);
339 else
340 CPU_SET(ie->ie_cpu, &mask);
341 id = ie->ie_thread->it_thread->td_tid;
342 mtx_unlock(&ie->ie_lock);
343 (void)cpuset_setthread(id, &mask);
344 } else
345 mtx_unlock(&ie->ie_lock);
346 return (error);
347 }
348
349 mtx_lock(&ie->ie_lock);
350 ie->ie_cpu = cpu;
351 mtx_unlock(&ie->ie_lock);
352
353 return (error);
354 }
355
356 static struct intr_event *
intr_lookup(int irq)357 intr_lookup(int irq)
358 {
359 struct intr_event *ie;
360
361 mtx_lock(&event_lock);
362 TAILQ_FOREACH(ie, &event_list, ie_list)
363 if (ie->ie_irq == irq &&
364 (ie->ie_flags & IE_SOFT) == 0 &&
365 TAILQ_FIRST(&ie->ie_handlers) != NULL)
366 break;
367 mtx_unlock(&event_lock);
368 return (ie);
369 }
370
371 int
intr_setaffinity(int irq,void * m)372 intr_setaffinity(int irq, void *m)
373 {
374 struct intr_event *ie;
375 cpuset_t *mask;
376 u_char cpu;
377 int n;
378
379 mask = m;
380 cpu = NOCPU;
381 /*
382 * If we're setting all cpus we can unbind. Otherwise make sure
383 * only one cpu is in the set.
384 */
385 if (CPU_CMP(cpuset_root, mask)) {
386 for (n = 0; n < CPU_SETSIZE; n++) {
387 if (!CPU_ISSET(n, mask))
388 continue;
389 if (cpu != NOCPU)
390 return (EINVAL);
391 cpu = (u_char)n;
392 }
393 }
394 ie = intr_lookup(irq);
395 if (ie == NULL)
396 return (ESRCH);
397 return (intr_event_bind(ie, cpu));
398 }
399
400 int
intr_getaffinity(int irq,void * m)401 intr_getaffinity(int irq, void *m)
402 {
403 struct intr_event *ie;
404 cpuset_t *mask;
405
406 mask = m;
407 ie = intr_lookup(irq);
408 if (ie == NULL)
409 return (ESRCH);
410 CPU_ZERO(mask);
411 mtx_lock(&ie->ie_lock);
412 if (ie->ie_cpu == NOCPU)
413 CPU_COPY(cpuset_root, mask);
414 else
415 CPU_SET(ie->ie_cpu, mask);
416 mtx_unlock(&ie->ie_lock);
417 return (0);
418 }
419
420 int
intr_event_destroy(struct intr_event * ie)421 intr_event_destroy(struct intr_event *ie)
422 {
423
424 mtx_lock(&event_lock);
425 mtx_lock(&ie->ie_lock);
426 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
427 mtx_unlock(&ie->ie_lock);
428 mtx_unlock(&event_lock);
429 return (EBUSY);
430 }
431 TAILQ_REMOVE(&event_list, ie, ie_list);
432 #ifndef notyet
433 if (ie->ie_thread != NULL) {
434 ithread_destroy(ie->ie_thread);
435 ie->ie_thread = NULL;
436 }
437 #endif
438 mtx_unlock(&ie->ie_lock);
439 mtx_unlock(&event_lock);
440 mtx_destroy(&ie->ie_lock);
441 free(ie, M_ITHREAD);
442 return (0);
443 }
444
445 #ifndef INTR_FILTER
446 static struct intr_thread *
ithread_create(const char * name)447 ithread_create(const char *name)
448 {
449 struct intr_thread *ithd;
450 struct thread *td;
451 int error;
452
453 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
454
455 error = kproc_kthread_add(ithread_loop, ithd, &intrproc,
456 &td, RFSTOPPED | RFHIGHPID,
457 0, "intr", "%s", name);
458 if (error)
459 panic("kproc_create() failed with %d", error);
460 thread_lock(td);
461 sched_class(td, PRI_ITHD);
462 TD_SET_IWAIT(td);
463 thread_unlock(td);
464 td->td_pflags |= TDP_ITHREAD;
465 ithd->it_thread = td;
466 CTR2(KTR_INTR, "%s: created %s", __func__, name);
467 return (ithd);
468 }
469 #else
470 static struct intr_thread *
ithread_create(const char * name,struct intr_handler * ih)471 ithread_create(const char *name, struct intr_handler *ih)
472 {
473 struct intr_thread *ithd;
474 struct thread *td;
475 int error;
476
477 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO);
478
479 error = kproc_kthread_add(ithread_loop, ih, &intrproc,
480 &td, RFSTOPPED | RFHIGHPID,
481 0, "intr", "%s", name);
482 if (error)
483 panic("kproc_create() failed with %d", error);
484 thread_lock(td);
485 sched_class(td, PRI_ITHD);
486 TD_SET_IWAIT(td);
487 thread_unlock(td);
488 td->td_pflags |= TDP_ITHREAD;
489 ithd->it_thread = td;
490 CTR2(KTR_INTR, "%s: created %s", __func__, name);
491 return (ithd);
492 }
493 #endif
494
495 static void
ithread_destroy(struct intr_thread * ithread)496 ithread_destroy(struct intr_thread *ithread)
497 {
498 struct thread *td;
499
500 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name);
501 td = ithread->it_thread;
502 thread_lock(td);
503 ithread->it_flags |= IT_DEAD;
504 if (TD_AWAITING_INTR(td)) {
505 TD_CLR_IWAIT(td);
506 sched_add(td, SRQ_INTR);
507 }
508 thread_unlock(td);
509 }
510
511 #ifndef INTR_FILTER
512 int
intr_event_add_handler(struct intr_event * ie,const char * name,driver_filter_t filter,driver_intr_t handler,void * arg,u_char pri,enum intr_type flags,void ** cookiep)513 intr_event_add_handler(struct intr_event *ie, const char *name,
514 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
515 enum intr_type flags, void **cookiep)
516 {
517 struct intr_handler *ih, *temp_ih;
518 struct intr_thread *it;
519
520 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
521 return (EINVAL);
522
523 /* Allocate and populate an interrupt handler structure. */
524 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
525 ih->ih_filter = filter;
526 ih->ih_handler = handler;
527 ih->ih_argument = arg;
528 strlcpy(ih->ih_name, name, sizeof(ih->ih_name));
529 ih->ih_event = ie;
530 ih->ih_pri = pri;
531 if (flags & INTR_EXCL)
532 ih->ih_flags = IH_EXCLUSIVE;
533 if (flags & INTR_MPSAFE)
534 ih->ih_flags |= IH_MPSAFE;
535 if (flags & INTR_ENTROPY)
536 ih->ih_flags |= IH_ENTROPY;
537
538 /* We can only have one exclusive handler in a event. */
539 mtx_lock(&ie->ie_lock);
540 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
541 if ((flags & INTR_EXCL) ||
542 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
543 mtx_unlock(&ie->ie_lock);
544 free(ih, M_ITHREAD);
545 return (EINVAL);
546 }
547 }
548
549 /* Create a thread if we need one. */
550 while (ie->ie_thread == NULL && handler != NULL) {
551 if (ie->ie_flags & IE_ADDING_THREAD)
552 msleep(ie, &ie->ie_lock, 0, "ithread", 0);
553 else {
554 ie->ie_flags |= IE_ADDING_THREAD;
555 mtx_unlock(&ie->ie_lock);
556 it = ithread_create("intr: newborn");
557 mtx_lock(&ie->ie_lock);
558 ie->ie_flags &= ~IE_ADDING_THREAD;
559 ie->ie_thread = it;
560 it->it_event = ie;
561 ithread_update(it);
562 wakeup(ie);
563 }
564 }
565
566 /* Add the new handler to the event in priority order. */
567 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
568 if (temp_ih->ih_pri > ih->ih_pri)
569 break;
570 }
571 if (temp_ih == NULL)
572 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
573 else
574 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
575 intr_event_update(ie);
576
577 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
578 ie->ie_name);
579 mtx_unlock(&ie->ie_lock);
580
581 if (cookiep != NULL)
582 *cookiep = ih;
583 return (0);
584 }
585 #else
586 int
intr_event_add_handler(struct intr_event * ie,const char * name,driver_filter_t filter,driver_intr_t handler,void * arg,u_char pri,enum intr_type flags,void ** cookiep)587 intr_event_add_handler(struct intr_event *ie, const char *name,
588 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri,
589 enum intr_type flags, void **cookiep)
590 {
591 struct intr_handler *ih, *temp_ih;
592 struct intr_thread *it;
593
594 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL))
595 return (EINVAL);
596
597 /* Allocate and populate an interrupt handler structure. */
598 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO);
599 ih->ih_filter = filter;
600 ih->ih_handler = handler;
601 ih->ih_argument = arg;
602 strlcpy(ih->ih_name, name, sizeof(ih->ih_name));
603 ih->ih_event = ie;
604 ih->ih_pri = pri;
605 if (flags & INTR_EXCL)
606 ih->ih_flags = IH_EXCLUSIVE;
607 if (flags & INTR_MPSAFE)
608 ih->ih_flags |= IH_MPSAFE;
609 if (flags & INTR_ENTROPY)
610 ih->ih_flags |= IH_ENTROPY;
611
612 /* We can only have one exclusive handler in a event. */
613 mtx_lock(&ie->ie_lock);
614 if (!TAILQ_EMPTY(&ie->ie_handlers)) {
615 if ((flags & INTR_EXCL) ||
616 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) {
617 mtx_unlock(&ie->ie_lock);
618 free(ih, M_ITHREAD);
619 return (EINVAL);
620 }
621 }
622
623 /* For filtered handlers, create a private ithread to run on. */
624 if (filter != NULL && handler != NULL) {
625 mtx_unlock(&ie->ie_lock);
626 it = ithread_create("intr: newborn", ih);
627 mtx_lock(&ie->ie_lock);
628 it->it_event = ie;
629 ih->ih_thread = it;
630 ithread_update(it); /* XXX - do we really need this?!?!? */
631 } else { /* Create the global per-event thread if we need one. */
632 while (ie->ie_thread == NULL && handler != NULL) {
633 if (ie->ie_flags & IE_ADDING_THREAD)
634 msleep(ie, &ie->ie_lock, 0, "ithread", 0);
635 else {
636 ie->ie_flags |= IE_ADDING_THREAD;
637 mtx_unlock(&ie->ie_lock);
638 it = ithread_create("intr: newborn", ih);
639 mtx_lock(&ie->ie_lock);
640 ie->ie_flags &= ~IE_ADDING_THREAD;
641 ie->ie_thread = it;
642 it->it_event = ie;
643 ithread_update(it);
644 wakeup(ie);
645 }
646 }
647 }
648
649 /* Add the new handler to the event in priority order. */
650 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) {
651 if (temp_ih->ih_pri > ih->ih_pri)
652 break;
653 }
654 if (temp_ih == NULL)
655 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next);
656 else
657 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next);
658 intr_event_update(ie);
659
660 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name,
661 ie->ie_name);
662 mtx_unlock(&ie->ie_lock);
663
664 if (cookiep != NULL)
665 *cookiep = ih;
666 return (0);
667 }
668 #endif
669
670 /*
671 * Append a description preceded by a ':' to the name of the specified
672 * interrupt handler.
673 */
674 int
intr_event_describe_handler(struct intr_event * ie,void * cookie,const char * descr)675 intr_event_describe_handler(struct intr_event *ie, void *cookie,
676 const char *descr)
677 {
678 struct intr_handler *ih;
679 size_t space;
680 char *start;
681
682 mtx_lock(&ie->ie_lock);
683 #ifdef INVARIANTS
684 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
685 if (ih == cookie)
686 break;
687 }
688 if (ih == NULL) {
689 mtx_unlock(&ie->ie_lock);
690 panic("handler %p not found in interrupt event %p", cookie, ie);
691 }
692 #endif
693 ih = cookie;
694
695 /*
696 * Look for an existing description by checking for an
697 * existing ":". This assumes device names do not include
698 * colons. If one is found, prepare to insert the new
699 * description at that point. If one is not found, find the
700 * end of the name to use as the insertion point.
701 */
702 start = strchr(ih->ih_name, ':');
703 if (start == NULL)
704 start = strchr(ih->ih_name, 0);
705
706 /*
707 * See if there is enough remaining room in the string for the
708 * description + ":". The "- 1" leaves room for the trailing
709 * '\0'. The "+ 1" accounts for the colon.
710 */
711 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1;
712 if (strlen(descr) + 1 > space) {
713 mtx_unlock(&ie->ie_lock);
714 return (ENOSPC);
715 }
716
717 /* Append a colon followed by the description. */
718 *start = ':';
719 strcpy(start + 1, descr);
720 intr_event_update(ie);
721 mtx_unlock(&ie->ie_lock);
722 return (0);
723 }
724
725 /*
726 * Return the ie_source field from the intr_event an intr_handler is
727 * associated with.
728 */
729 void *
intr_handler_source(void * cookie)730 intr_handler_source(void *cookie)
731 {
732 struct intr_handler *ih;
733 struct intr_event *ie;
734
735 ih = (struct intr_handler *)cookie;
736 if (ih == NULL)
737 return (NULL);
738 ie = ih->ih_event;
739 KASSERT(ie != NULL,
740 ("interrupt handler \"%s\" has a NULL interrupt event",
741 ih->ih_name));
742 return (ie->ie_source);
743 }
744
745 /*
746 * Sleep until an ithread finishes executing an interrupt handler.
747 *
748 * XXX Doesn't currently handle interrupt filters or fast interrupt
749 * handlers. This is intended for compatibility with linux drivers
750 * only. Do not use in BSD code.
751 */
752 void
_intr_drain(int irq)753 _intr_drain(int irq)
754 {
755 struct intr_event *ie;
756 struct intr_thread *ithd;
757 struct thread *td;
758
759 ie = intr_lookup(irq);
760 if (ie == NULL)
761 return;
762 if (ie->ie_thread == NULL)
763 return;
764 ithd = ie->ie_thread;
765 td = ithd->it_thread;
766 /*
767 * We set the flag and wait for it to be cleared to avoid
768 * long delays with potentially busy interrupt handlers
769 * were we to only sample TD_AWAITING_INTR() every tick.
770 */
771 thread_lock(td);
772 if (!TD_AWAITING_INTR(td)) {
773 ithd->it_flags |= IT_WAIT;
774 while (ithd->it_flags & IT_WAIT) {
775 thread_unlock(td);
776 pause("idrain", 1);
777 thread_lock(td);
778 }
779 }
780 thread_unlock(td);
781 return;
782 }
783
784
785 #ifndef INTR_FILTER
786 int
intr_event_remove_handler(void * cookie)787 intr_event_remove_handler(void *cookie)
788 {
789 struct intr_handler *handler = (struct intr_handler *)cookie;
790 struct intr_event *ie;
791 #ifdef INVARIANTS
792 struct intr_handler *ih;
793 #endif
794 #ifdef notyet
795 int dead;
796 #endif
797
798 if (handler == NULL)
799 return (EINVAL);
800 ie = handler->ih_event;
801 KASSERT(ie != NULL,
802 ("interrupt handler \"%s\" has a NULL interrupt event",
803 handler->ih_name));
804 mtx_lock(&ie->ie_lock);
805 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
806 ie->ie_name);
807 #ifdef INVARIANTS
808 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
809 if (ih == handler)
810 goto ok;
811 mtx_unlock(&ie->ie_lock);
812 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
813 ih->ih_name, ie->ie_name);
814 ok:
815 #endif
816 /*
817 * If there is no ithread, then just remove the handler and return.
818 * XXX: Note that an INTR_FAST handler might be running on another
819 * CPU!
820 */
821 if (ie->ie_thread == NULL) {
822 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
823 mtx_unlock(&ie->ie_lock);
824 free(handler, M_ITHREAD);
825 return (0);
826 }
827
828 /*
829 * If the interrupt thread is already running, then just mark this
830 * handler as being dead and let the ithread do the actual removal.
831 *
832 * During a cold boot while cold is set, msleep() does not sleep,
833 * so we have to remove the handler here rather than letting the
834 * thread do it.
835 */
836 thread_lock(ie->ie_thread->it_thread);
837 if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) {
838 handler->ih_flags |= IH_DEAD;
839
840 /*
841 * Ensure that the thread will process the handler list
842 * again and remove this handler if it has already passed
843 * it on the list.
844 */
845 atomic_store_rel_int(&ie->ie_thread->it_need, 1);
846 } else
847 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
848 thread_unlock(ie->ie_thread->it_thread);
849 while (handler->ih_flags & IH_DEAD)
850 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
851 intr_event_update(ie);
852 #ifdef notyet
853 /*
854 * XXX: This could be bad in the case of ppbus(8). Also, I think
855 * this could lead to races of stale data when servicing an
856 * interrupt.
857 */
858 dead = 1;
859 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
860 if (!(ih->ih_flags & IH_FAST)) {
861 dead = 0;
862 break;
863 }
864 }
865 if (dead) {
866 ithread_destroy(ie->ie_thread);
867 ie->ie_thread = NULL;
868 }
869 #endif
870 mtx_unlock(&ie->ie_lock);
871 free(handler, M_ITHREAD);
872 return (0);
873 }
874
875 static int
intr_event_schedule_thread(struct intr_event * ie)876 intr_event_schedule_thread(struct intr_event *ie)
877 {
878 struct intr_entropy entropy;
879 struct intr_thread *it;
880 struct thread *td;
881 struct thread *ctd;
882 struct proc *p;
883
884 /*
885 * If no ithread or no handlers, then we have a stray interrupt.
886 */
887 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) ||
888 ie->ie_thread == NULL)
889 return (EINVAL);
890
891 ctd = curthread;
892 it = ie->ie_thread;
893 td = it->it_thread;
894 p = td->td_proc;
895
896 /*
897 * If any of the handlers for this ithread claim to be good
898 * sources of entropy, then gather some.
899 */
900 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
901 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
902 p->p_pid, td->td_name);
903 entropy.event = (uintptr_t)ie;
904 entropy.td = ctd;
905 random_harvest(&entropy, sizeof(entropy), 2,
906 RANDOM_INTERRUPT);
907 }
908
909 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
910
911 /*
912 * Set it_need to tell the thread to keep running if it is already
913 * running. Then, lock the thread and see if we actually need to
914 * put it on the runqueue.
915 */
916 atomic_store_rel_int(&it->it_need, 1);
917 thread_lock(td);
918 if (TD_AWAITING_INTR(td)) {
919 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
920 td->td_name);
921 TD_CLR_IWAIT(td);
922 sched_add(td, SRQ_INTR);
923 } else {
924 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
925 __func__, p->p_pid, td->td_name, it->it_need, td->td_state);
926 }
927 thread_unlock(td);
928
929 return (0);
930 }
931 #else
932 int
intr_event_remove_handler(void * cookie)933 intr_event_remove_handler(void *cookie)
934 {
935 struct intr_handler *handler = (struct intr_handler *)cookie;
936 struct intr_event *ie;
937 struct intr_thread *it;
938 #ifdef INVARIANTS
939 struct intr_handler *ih;
940 #endif
941 #ifdef notyet
942 int dead;
943 #endif
944
945 if (handler == NULL)
946 return (EINVAL);
947 ie = handler->ih_event;
948 KASSERT(ie != NULL,
949 ("interrupt handler \"%s\" has a NULL interrupt event",
950 handler->ih_name));
951 mtx_lock(&ie->ie_lock);
952 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name,
953 ie->ie_name);
954 #ifdef INVARIANTS
955 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
956 if (ih == handler)
957 goto ok;
958 mtx_unlock(&ie->ie_lock);
959 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"",
960 ih->ih_name, ie->ie_name);
961 ok:
962 #endif
963 /*
964 * If there are no ithreads (per event and per handler), then
965 * just remove the handler and return.
966 * XXX: Note that an INTR_FAST handler might be running on another CPU!
967 */
968 if (ie->ie_thread == NULL && handler->ih_thread == NULL) {
969 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
970 mtx_unlock(&ie->ie_lock);
971 free(handler, M_ITHREAD);
972 return (0);
973 }
974
975 /* Private or global ithread? */
976 it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread;
977 /*
978 * If the interrupt thread is already running, then just mark this
979 * handler as being dead and let the ithread do the actual removal.
980 *
981 * During a cold boot while cold is set, msleep() does not sleep,
982 * so we have to remove the handler here rather than letting the
983 * thread do it.
984 */
985 thread_lock(it->it_thread);
986 if (!TD_AWAITING_INTR(it->it_thread) && !cold) {
987 handler->ih_flags |= IH_DEAD;
988
989 /*
990 * Ensure that the thread will process the handler list
991 * again and remove this handler if it has already passed
992 * it on the list.
993 */
994 atomic_store_rel_int(&it->it_need, 1);
995 } else
996 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next);
997 thread_unlock(it->it_thread);
998 while (handler->ih_flags & IH_DEAD)
999 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0);
1000 /*
1001 * At this point, the handler has been disconnected from the event,
1002 * so we can kill the private ithread if any.
1003 */
1004 if (handler->ih_thread) {
1005 ithread_destroy(handler->ih_thread);
1006 handler->ih_thread = NULL;
1007 }
1008 intr_event_update(ie);
1009 #ifdef notyet
1010 /*
1011 * XXX: This could be bad in the case of ppbus(8). Also, I think
1012 * this could lead to races of stale data when servicing an
1013 * interrupt.
1014 */
1015 dead = 1;
1016 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1017 if (handler != NULL) {
1018 dead = 0;
1019 break;
1020 }
1021 }
1022 if (dead) {
1023 ithread_destroy(ie->ie_thread);
1024 ie->ie_thread = NULL;
1025 }
1026 #endif
1027 mtx_unlock(&ie->ie_lock);
1028 free(handler, M_ITHREAD);
1029 return (0);
1030 }
1031
1032 static int
intr_event_schedule_thread(struct intr_event * ie,struct intr_thread * it)1033 intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it)
1034 {
1035 struct intr_entropy entropy;
1036 struct thread *td;
1037 struct thread *ctd;
1038 struct proc *p;
1039
1040 /*
1041 * If no ithread or no handlers, then we have a stray interrupt.
1042 */
1043 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || it == NULL)
1044 return (EINVAL);
1045
1046 ctd = curthread;
1047 td = it->it_thread;
1048 p = td->td_proc;
1049
1050 /*
1051 * If any of the handlers for this ithread claim to be good
1052 * sources of entropy, then gather some.
1053 */
1054 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) {
1055 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__,
1056 p->p_pid, td->td_name);
1057 entropy.event = (uintptr_t)ie;
1058 entropy.td = ctd;
1059 random_harvest(&entropy, sizeof(entropy), 2,
1060 RANDOM_INTERRUPT);
1061 }
1062
1063 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name));
1064
1065 /*
1066 * Set it_need to tell the thread to keep running if it is already
1067 * running. Then, lock the thread and see if we actually need to
1068 * put it on the runqueue.
1069 */
1070 atomic_store_rel_int(&it->it_need, 1);
1071 thread_lock(td);
1072 if (TD_AWAITING_INTR(td)) {
1073 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid,
1074 td->td_name);
1075 TD_CLR_IWAIT(td);
1076 sched_add(td, SRQ_INTR);
1077 } else {
1078 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d",
1079 __func__, p->p_pid, td->td_name, it->it_need, td->td_state);
1080 }
1081 thread_unlock(td);
1082
1083 return (0);
1084 }
1085 #endif
1086
1087 /*
1088 * Allow interrupt event binding for software interrupt handlers -- a no-op,
1089 * since interrupts are generated in software rather than being directed by
1090 * a PIC.
1091 */
1092 static int
swi_assign_cpu(void * arg,u_char cpu)1093 swi_assign_cpu(void *arg, u_char cpu)
1094 {
1095
1096 return (0);
1097 }
1098
1099 /*
1100 * Add a software interrupt handler to a specified event. If a given event
1101 * is not specified, then a new event is created.
1102 */
1103 int
swi_add(struct intr_event ** eventp,const char * name,driver_intr_t handler,void * arg,int pri,enum intr_type flags,void ** cookiep)1104 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler,
1105 void *arg, int pri, enum intr_type flags, void **cookiep)
1106 {
1107 struct intr_event *ie;
1108 int error;
1109
1110 if (flags & INTR_ENTROPY)
1111 return (EINVAL);
1112
1113 ie = (eventp != NULL) ? *eventp : NULL;
1114
1115 if (ie != NULL) {
1116 if (!(ie->ie_flags & IE_SOFT))
1117 return (EINVAL);
1118 } else {
1119 error = intr_event_create(&ie, NULL, IE_SOFT, 0,
1120 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri);
1121 if (error)
1122 return (error);
1123 if (eventp != NULL)
1124 *eventp = ie;
1125 }
1126 error = intr_event_add_handler(ie, name, NULL, handler, arg,
1127 PI_SWI(pri), flags, cookiep);
1128 return (error);
1129 }
1130
1131 /*
1132 * Schedule a software interrupt thread.
1133 */
1134 void
swi_sched(void * cookie,int flags)1135 swi_sched(void *cookie, int flags)
1136 {
1137 struct intr_handler *ih = (struct intr_handler *)cookie;
1138 struct intr_event *ie = ih->ih_event;
1139 struct intr_entropy entropy;
1140 int error;
1141
1142 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name,
1143 ih->ih_need);
1144
1145 if (harvest.swi) {
1146 CTR2(KTR_INTR, "swi_sched: pid %d (%s) gathering entropy",
1147 curproc->p_pid, curthread->td_name);
1148 entropy.event = (uintptr_t)ih;
1149 entropy.td = curthread;
1150 random_harvest(&entropy, sizeof(entropy), 1,
1151 RANDOM_SWI);
1152 }
1153
1154 /*
1155 * Set ih_need for this handler so that if the ithread is already
1156 * running it will execute this handler on the next pass. Otherwise,
1157 * it will execute it the next time it runs.
1158 */
1159 atomic_store_rel_int(&ih->ih_need, 1);
1160
1161 if (!(flags & SWI_DELAY)) {
1162 PCPU_INC(cnt.v_soft);
1163 #ifdef INTR_FILTER
1164 error = intr_event_schedule_thread(ie, ie->ie_thread);
1165 #else
1166 error = intr_event_schedule_thread(ie);
1167 #endif
1168 KASSERT(error == 0, ("stray software interrupt"));
1169 }
1170 }
1171
1172 /*
1173 * Remove a software interrupt handler. Currently this code does not
1174 * remove the associated interrupt event if it becomes empty. Calling code
1175 * may do so manually via intr_event_destroy(), but that's not really
1176 * an optimal interface.
1177 */
1178 int
swi_remove(void * cookie)1179 swi_remove(void *cookie)
1180 {
1181
1182 return (intr_event_remove_handler(cookie));
1183 }
1184
1185 #ifdef INTR_FILTER
1186 static void
priv_ithread_execute_handler(struct proc * p,struct intr_handler * ih)1187 priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih)
1188 {
1189 struct intr_event *ie;
1190
1191 ie = ih->ih_event;
1192 /*
1193 * If this handler is marked for death, remove it from
1194 * the list of handlers and wake up the sleeper.
1195 */
1196 if (ih->ih_flags & IH_DEAD) {
1197 mtx_lock(&ie->ie_lock);
1198 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
1199 ih->ih_flags &= ~IH_DEAD;
1200 wakeup(ih);
1201 mtx_unlock(&ie->ie_lock);
1202 return;
1203 }
1204
1205 /* Execute this handler. */
1206 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1207 __func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument,
1208 ih->ih_name, ih->ih_flags);
1209
1210 if (!(ih->ih_flags & IH_MPSAFE))
1211 mtx_lock(&Giant);
1212 ih->ih_handler(ih->ih_argument);
1213 if (!(ih->ih_flags & IH_MPSAFE))
1214 mtx_unlock(&Giant);
1215 }
1216 #endif
1217
1218 /*
1219 * This is a public function for use by drivers that mux interrupt
1220 * handlers for child devices from their interrupt handler.
1221 */
1222 void
intr_event_execute_handlers(struct proc * p,struct intr_event * ie)1223 intr_event_execute_handlers(struct proc *p, struct intr_event *ie)
1224 {
1225 struct intr_handler *ih, *ihn;
1226
1227 TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) {
1228 /*
1229 * If this handler is marked for death, remove it from
1230 * the list of handlers and wake up the sleeper.
1231 */
1232 if (ih->ih_flags & IH_DEAD) {
1233 mtx_lock(&ie->ie_lock);
1234 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next);
1235 ih->ih_flags &= ~IH_DEAD;
1236 wakeup(ih);
1237 mtx_unlock(&ie->ie_lock);
1238 continue;
1239 }
1240
1241 /* Skip filter only handlers */
1242 if (ih->ih_handler == NULL)
1243 continue;
1244
1245 /*
1246 * For software interrupt threads, we only execute
1247 * handlers that have their need flag set. Hardware
1248 * interrupt threads always invoke all of their handlers.
1249 */
1250 if (ie->ie_flags & IE_SOFT) {
1251 if (atomic_load_acq_int(&ih->ih_need) == 0)
1252 continue;
1253 else
1254 atomic_store_rel_int(&ih->ih_need, 0);
1255 }
1256
1257 /* Execute this handler. */
1258 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x",
1259 __func__, p->p_pid, (void *)ih->ih_handler,
1260 ih->ih_argument, ih->ih_name, ih->ih_flags);
1261
1262 if (!(ih->ih_flags & IH_MPSAFE))
1263 mtx_lock(&Giant);
1264 ih->ih_handler(ih->ih_argument);
1265 if (!(ih->ih_flags & IH_MPSAFE))
1266 mtx_unlock(&Giant);
1267 }
1268 }
1269
1270 static void
ithread_execute_handlers(struct proc * p,struct intr_event * ie)1271 ithread_execute_handlers(struct proc *p, struct intr_event *ie)
1272 {
1273
1274 /* Interrupt handlers should not sleep. */
1275 if (!(ie->ie_flags & IE_SOFT))
1276 THREAD_NO_SLEEPING();
1277 intr_event_execute_handlers(p, ie);
1278 if (!(ie->ie_flags & IE_SOFT))
1279 THREAD_SLEEPING_OK();
1280
1281 /*
1282 * Interrupt storm handling:
1283 *
1284 * If this interrupt source is currently storming, then throttle
1285 * it to only fire the handler once per clock tick.
1286 *
1287 * If this interrupt source is not currently storming, but the
1288 * number of back to back interrupts exceeds the storm threshold,
1289 * then enter storming mode.
1290 */
1291 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold &&
1292 !(ie->ie_flags & IE_SOFT)) {
1293 /* Report the message only once every second. */
1294 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) {
1295 printf(
1296 "interrupt storm detected on \"%s\"; throttling interrupt source\n",
1297 ie->ie_name);
1298 }
1299 pause("istorm", 1);
1300 } else
1301 ie->ie_count++;
1302
1303 /*
1304 * Now that all the handlers have had a chance to run, reenable
1305 * the interrupt source.
1306 */
1307 if (ie->ie_post_ithread != NULL)
1308 ie->ie_post_ithread(ie->ie_source);
1309 }
1310
1311 #ifndef INTR_FILTER
1312 /*
1313 * This is the main code for interrupt threads.
1314 */
1315 static void
ithread_loop(void * arg)1316 ithread_loop(void *arg)
1317 {
1318 struct intr_thread *ithd;
1319 struct intr_event *ie;
1320 struct thread *td;
1321 struct proc *p;
1322 int wake;
1323
1324 td = curthread;
1325 p = td->td_proc;
1326 ithd = (struct intr_thread *)arg;
1327 KASSERT(ithd->it_thread == td,
1328 ("%s: ithread and proc linkage out of sync", __func__));
1329 ie = ithd->it_event;
1330 ie->ie_count = 0;
1331 wake = 0;
1332
1333 /*
1334 * As long as we have interrupts outstanding, go through the
1335 * list of handlers, giving each one a go at it.
1336 */
1337 for (;;) {
1338 /*
1339 * If we are an orphaned thread, then just die.
1340 */
1341 if (ithd->it_flags & IT_DEAD) {
1342 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1343 p->p_pid, td->td_name);
1344 free(ithd, M_ITHREAD);
1345 kthread_exit();
1346 }
1347
1348 /*
1349 * Service interrupts. If another interrupt arrives while
1350 * we are running, it will set it_need to note that we
1351 * should make another pass.
1352 */
1353 while (atomic_load_acq_int(&ithd->it_need) != 0) {
1354 /*
1355 * This might need a full read and write barrier
1356 * to make sure that this write posts before any
1357 * of the memory or device accesses in the
1358 * handlers.
1359 */
1360 atomic_store_rel_int(&ithd->it_need, 0);
1361 ithread_execute_handlers(p, ie);
1362 }
1363 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1364 mtx_assert(&Giant, MA_NOTOWNED);
1365
1366 /*
1367 * Processed all our interrupts. Now get the sched
1368 * lock. This may take a while and it_need may get
1369 * set again, so we have to check it again.
1370 */
1371 thread_lock(td);
1372 if ((atomic_load_acq_int(&ithd->it_need) == 0) &&
1373 !(ithd->it_flags & (IT_DEAD | IT_WAIT))) {
1374 TD_SET_IWAIT(td);
1375 ie->ie_count = 0;
1376 mi_switch(SW_VOL | SWT_IWAIT, NULL);
1377 }
1378 if (ithd->it_flags & IT_WAIT) {
1379 wake = 1;
1380 ithd->it_flags &= ~IT_WAIT;
1381 }
1382 thread_unlock(td);
1383 if (wake) {
1384 wakeup(ithd);
1385 wake = 0;
1386 }
1387 }
1388 }
1389
1390 /*
1391 * Main interrupt handling body.
1392 *
1393 * Input:
1394 * o ie: the event connected to this interrupt.
1395 * o frame: some archs (i.e. i386) pass a frame to some.
1396 * handlers as their main argument.
1397 * Return value:
1398 * o 0: everything ok.
1399 * o EINVAL: stray interrupt.
1400 */
1401 int
intr_event_handle(struct intr_event * ie,struct trapframe * frame)1402 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1403 {
1404 struct intr_handler *ih;
1405 struct trapframe *oldframe;
1406 struct thread *td;
1407 int error, ret, thread;
1408
1409 td = curthread;
1410
1411 #ifdef KSTACK_USAGE_PROF
1412 intr_prof_stack_use(td, frame);
1413 #endif
1414
1415 /* An interrupt with no event or handlers is a stray interrupt. */
1416 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
1417 return (EINVAL);
1418
1419 /*
1420 * Execute fast interrupt handlers directly.
1421 * To support clock handlers, if a handler registers
1422 * with a NULL argument, then we pass it a pointer to
1423 * a trapframe as its argument.
1424 */
1425 td->td_intr_nesting_level++;
1426 thread = 0;
1427 ret = 0;
1428 critical_enter();
1429 oldframe = td->td_intr_frame;
1430 td->td_intr_frame = frame;
1431 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1432 if (ih->ih_filter == NULL) {
1433 thread = 1;
1434 continue;
1435 }
1436 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__,
1437 ih->ih_filter, ih->ih_argument == NULL ? frame :
1438 ih->ih_argument, ih->ih_name);
1439 if (ih->ih_argument == NULL)
1440 ret = ih->ih_filter(frame);
1441 else
1442 ret = ih->ih_filter(ih->ih_argument);
1443 KASSERT(ret == FILTER_STRAY ||
1444 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 &&
1445 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0),
1446 ("%s: incorrect return value %#x from %s", __func__, ret,
1447 ih->ih_name));
1448
1449 /*
1450 * Wrapper handler special handling:
1451 *
1452 * in some particular cases (like pccard and pccbb),
1453 * the _real_ device handler is wrapped in a couple of
1454 * functions - a filter wrapper and an ithread wrapper.
1455 * In this case (and just in this case), the filter wrapper
1456 * could ask the system to schedule the ithread and mask
1457 * the interrupt source if the wrapped handler is composed
1458 * of just an ithread handler.
1459 *
1460 * TODO: write a generic wrapper to avoid people rolling
1461 * their own
1462 */
1463 if (!thread) {
1464 if (ret == FILTER_SCHEDULE_THREAD)
1465 thread = 1;
1466 }
1467 }
1468 td->td_intr_frame = oldframe;
1469
1470 if (thread) {
1471 if (ie->ie_pre_ithread != NULL)
1472 ie->ie_pre_ithread(ie->ie_source);
1473 } else {
1474 if (ie->ie_post_filter != NULL)
1475 ie->ie_post_filter(ie->ie_source);
1476 }
1477
1478 /* Schedule the ithread if needed. */
1479 if (thread) {
1480 error = intr_event_schedule_thread(ie);
1481 #ifndef XEN
1482 KASSERT(error == 0, ("bad stray interrupt"));
1483 #else
1484 if (error != 0)
1485 log(LOG_WARNING, "bad stray interrupt");
1486 #endif
1487 }
1488 critical_exit();
1489 td->td_intr_nesting_level--;
1490 return (0);
1491 }
1492 #else
1493 /*
1494 * This is the main code for interrupt threads.
1495 */
1496 static void
ithread_loop(void * arg)1497 ithread_loop(void *arg)
1498 {
1499 struct intr_thread *ithd;
1500 struct intr_handler *ih;
1501 struct intr_event *ie;
1502 struct thread *td;
1503 struct proc *p;
1504 int priv;
1505 int wake;
1506
1507 td = curthread;
1508 p = td->td_proc;
1509 ih = (struct intr_handler *)arg;
1510 priv = (ih->ih_thread != NULL) ? 1 : 0;
1511 ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread;
1512 KASSERT(ithd->it_thread == td,
1513 ("%s: ithread and proc linkage out of sync", __func__));
1514 ie = ithd->it_event;
1515 ie->ie_count = 0;
1516 wake = 0;
1517
1518 /*
1519 * As long as we have interrupts outstanding, go through the
1520 * list of handlers, giving each one a go at it.
1521 */
1522 for (;;) {
1523 /*
1524 * If we are an orphaned thread, then just die.
1525 */
1526 if (ithd->it_flags & IT_DEAD) {
1527 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__,
1528 p->p_pid, td->td_name);
1529 free(ithd, M_ITHREAD);
1530 kthread_exit();
1531 }
1532
1533 /*
1534 * Service interrupts. If another interrupt arrives while
1535 * we are running, it will set it_need to note that we
1536 * should make another pass.
1537 */
1538 while (atomic_load_acq_int(&ithd->it_need) != 0) {
1539 /*
1540 * This might need a full read and write barrier
1541 * to make sure that this write posts before any
1542 * of the memory or device accesses in the
1543 * handlers.
1544 */
1545 atomic_store_rel_int(&ithd->it_need, 0);
1546 if (priv)
1547 priv_ithread_execute_handler(p, ih);
1548 else
1549 ithread_execute_handlers(p, ie);
1550 }
1551 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread");
1552 mtx_assert(&Giant, MA_NOTOWNED);
1553
1554 /*
1555 * Processed all our interrupts. Now get the sched
1556 * lock. This may take a while and it_need may get
1557 * set again, so we have to check it again.
1558 */
1559 thread_lock(td);
1560 if ((atomic_load_acq_int(&ithd->it_need) == 0) &&
1561 !(ithd->it_flags & (IT_DEAD | IT_WAIT))) {
1562 TD_SET_IWAIT(td);
1563 ie->ie_count = 0;
1564 mi_switch(SW_VOL | SWT_IWAIT, NULL);
1565 }
1566 if (ithd->it_flags & IT_WAIT) {
1567 wake = 1;
1568 ithd->it_flags &= ~IT_WAIT;
1569 }
1570 thread_unlock(td);
1571 if (wake) {
1572 wakeup(ithd);
1573 wake = 0;
1574 }
1575 }
1576 }
1577
1578 /*
1579 * Main loop for interrupt filter.
1580 *
1581 * Some architectures (i386, amd64 and arm) require the optional frame
1582 * parameter, and use it as the main argument for fast handler execution
1583 * when ih_argument == NULL.
1584 *
1585 * Return value:
1586 * o FILTER_STRAY: No filter recognized the event, and no
1587 * filter-less handler is registered on this
1588 * line.
1589 * o FILTER_HANDLED: A filter claimed the event and served it.
1590 * o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at
1591 * least one filter-less handler on this line.
1592 * o FILTER_HANDLED |
1593 * FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for
1594 * scheduling the per-handler ithread.
1595 *
1596 * In case an ithread has to be scheduled, in *ithd there will be a
1597 * pointer to a struct intr_thread containing the thread to be
1598 * scheduled.
1599 */
1600
1601 static int
intr_filter_loop(struct intr_event * ie,struct trapframe * frame,struct intr_thread ** ithd)1602 intr_filter_loop(struct intr_event *ie, struct trapframe *frame,
1603 struct intr_thread **ithd)
1604 {
1605 struct intr_handler *ih;
1606 void *arg;
1607 int ret, thread_only;
1608
1609 ret = 0;
1610 thread_only = 0;
1611 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) {
1612 /*
1613 * Execute fast interrupt handlers directly.
1614 * To support clock handlers, if a handler registers
1615 * with a NULL argument, then we pass it a pointer to
1616 * a trapframe as its argument.
1617 */
1618 arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument);
1619
1620 CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__,
1621 ih->ih_filter, ih->ih_handler, arg, ih->ih_name);
1622
1623 if (ih->ih_filter != NULL)
1624 ret = ih->ih_filter(arg);
1625 else {
1626 thread_only = 1;
1627 continue;
1628 }
1629 KASSERT(ret == FILTER_STRAY ||
1630 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 &&
1631 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0),
1632 ("%s: incorrect return value %#x from %s", __func__, ret,
1633 ih->ih_name));
1634 if (ret & FILTER_STRAY)
1635 continue;
1636 else {
1637 *ithd = ih->ih_thread;
1638 return (ret);
1639 }
1640 }
1641
1642 /*
1643 * No filters handled the interrupt and we have at least
1644 * one handler without a filter. In this case, we schedule
1645 * all of the filter-less handlers to run in the ithread.
1646 */
1647 if (thread_only) {
1648 *ithd = ie->ie_thread;
1649 return (FILTER_SCHEDULE_THREAD);
1650 }
1651 return (FILTER_STRAY);
1652 }
1653
1654 /*
1655 * Main interrupt handling body.
1656 *
1657 * Input:
1658 * o ie: the event connected to this interrupt.
1659 * o frame: some archs (i.e. i386) pass a frame to some.
1660 * handlers as their main argument.
1661 * Return value:
1662 * o 0: everything ok.
1663 * o EINVAL: stray interrupt.
1664 */
1665 int
intr_event_handle(struct intr_event * ie,struct trapframe * frame)1666 intr_event_handle(struct intr_event *ie, struct trapframe *frame)
1667 {
1668 struct intr_thread *ithd;
1669 struct trapframe *oldframe;
1670 struct thread *td;
1671 int thread;
1672
1673 ithd = NULL;
1674 td = curthread;
1675
1676 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers))
1677 return (EINVAL);
1678
1679 td->td_intr_nesting_level++;
1680 thread = 0;
1681 critical_enter();
1682 oldframe = td->td_intr_frame;
1683 td->td_intr_frame = frame;
1684 thread = intr_filter_loop(ie, frame, &ithd);
1685 if (thread & FILTER_HANDLED) {
1686 if (ie->ie_post_filter != NULL)
1687 ie->ie_post_filter(ie->ie_source);
1688 } else {
1689 if (ie->ie_pre_ithread != NULL)
1690 ie->ie_pre_ithread(ie->ie_source);
1691 }
1692 td->td_intr_frame = oldframe;
1693 critical_exit();
1694
1695 /* Interrupt storm logic */
1696 if (thread & FILTER_STRAY) {
1697 ie->ie_count++;
1698 if (ie->ie_count < intr_storm_threshold)
1699 printf("Interrupt stray detection not present\n");
1700 }
1701
1702 /* Schedule an ithread if needed. */
1703 if (thread & FILTER_SCHEDULE_THREAD) {
1704 if (intr_event_schedule_thread(ie, ithd) != 0)
1705 panic("%s: impossible stray interrupt", __func__);
1706 }
1707 td->td_intr_nesting_level--;
1708 return (0);
1709 }
1710 #endif
1711
1712 #ifdef DDB
1713 /*
1714 * Dump details about an interrupt handler
1715 */
1716 static void
db_dump_intrhand(struct intr_handler * ih)1717 db_dump_intrhand(struct intr_handler *ih)
1718 {
1719 int comma;
1720
1721 db_printf("\t%-10s ", ih->ih_name);
1722 switch (ih->ih_pri) {
1723 case PI_REALTIME:
1724 db_printf("CLK ");
1725 break;
1726 case PI_AV:
1727 db_printf("AV ");
1728 break;
1729 case PI_TTY:
1730 db_printf("TTY ");
1731 break;
1732 case PI_NET:
1733 db_printf("NET ");
1734 break;
1735 case PI_DISK:
1736 db_printf("DISK");
1737 break;
1738 case PI_DULL:
1739 db_printf("DULL");
1740 break;
1741 default:
1742 if (ih->ih_pri >= PI_SOFT)
1743 db_printf("SWI ");
1744 else
1745 db_printf("%4u", ih->ih_pri);
1746 break;
1747 }
1748 db_printf(" ");
1749 if (ih->ih_filter != NULL) {
1750 db_printf("[F]");
1751 db_printsym((uintptr_t)ih->ih_filter, DB_STGY_PROC);
1752 }
1753 if (ih->ih_handler != NULL) {
1754 if (ih->ih_filter != NULL)
1755 db_printf(",");
1756 db_printf("[H]");
1757 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC);
1758 }
1759 db_printf("(%p)", ih->ih_argument);
1760 if (ih->ih_need ||
1761 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD |
1762 IH_MPSAFE)) != 0) {
1763 db_printf(" {");
1764 comma = 0;
1765 if (ih->ih_flags & IH_EXCLUSIVE) {
1766 if (comma)
1767 db_printf(", ");
1768 db_printf("EXCL");
1769 comma = 1;
1770 }
1771 if (ih->ih_flags & IH_ENTROPY) {
1772 if (comma)
1773 db_printf(", ");
1774 db_printf("ENTROPY");
1775 comma = 1;
1776 }
1777 if (ih->ih_flags & IH_DEAD) {
1778 if (comma)
1779 db_printf(", ");
1780 db_printf("DEAD");
1781 comma = 1;
1782 }
1783 if (ih->ih_flags & IH_MPSAFE) {
1784 if (comma)
1785 db_printf(", ");
1786 db_printf("MPSAFE");
1787 comma = 1;
1788 }
1789 if (ih->ih_need) {
1790 if (comma)
1791 db_printf(", ");
1792 db_printf("NEED");
1793 }
1794 db_printf("}");
1795 }
1796 db_printf("\n");
1797 }
1798
1799 /*
1800 * Dump details about a event.
1801 */
1802 void
db_dump_intr_event(struct intr_event * ie,int handlers)1803 db_dump_intr_event(struct intr_event *ie, int handlers)
1804 {
1805 struct intr_handler *ih;
1806 struct intr_thread *it;
1807 int comma;
1808
1809 db_printf("%s ", ie->ie_fullname);
1810 it = ie->ie_thread;
1811 if (it != NULL)
1812 db_printf("(pid %d)", it->it_thread->td_proc->p_pid);
1813 else
1814 db_printf("(no thread)");
1815 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 ||
1816 (it != NULL && it->it_need)) {
1817 db_printf(" {");
1818 comma = 0;
1819 if (ie->ie_flags & IE_SOFT) {
1820 db_printf("SOFT");
1821 comma = 1;
1822 }
1823 if (ie->ie_flags & IE_ENTROPY) {
1824 if (comma)
1825 db_printf(", ");
1826 db_printf("ENTROPY");
1827 comma = 1;
1828 }
1829 if (ie->ie_flags & IE_ADDING_THREAD) {
1830 if (comma)
1831 db_printf(", ");
1832 db_printf("ADDING_THREAD");
1833 comma = 1;
1834 }
1835 if (it != NULL && it->it_need) {
1836 if (comma)
1837 db_printf(", ");
1838 db_printf("NEED");
1839 }
1840 db_printf("}");
1841 }
1842 db_printf("\n");
1843
1844 if (handlers)
1845 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next)
1846 db_dump_intrhand(ih);
1847 }
1848
1849 /*
1850 * Dump data about interrupt handlers
1851 */
DB_SHOW_COMMAND(intr,db_show_intr)1852 DB_SHOW_COMMAND(intr, db_show_intr)
1853 {
1854 struct intr_event *ie;
1855 int all, verbose;
1856
1857 verbose = strchr(modif, 'v') != NULL;
1858 all = strchr(modif, 'a') != NULL;
1859 TAILQ_FOREACH(ie, &event_list, ie_list) {
1860 if (!all && TAILQ_EMPTY(&ie->ie_handlers))
1861 continue;
1862 db_dump_intr_event(ie, verbose);
1863 if (db_pager_quit)
1864 break;
1865 }
1866 }
1867 #endif /* DDB */
1868
1869 /*
1870 * Start standard software interrupt threads
1871 */
1872 static void
start_softintr(void * dummy)1873 start_softintr(void *dummy)
1874 {
1875
1876 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih))
1877 panic("died while creating vm swi ithread");
1878 }
1879 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr,
1880 NULL);
1881
1882 /*
1883 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt.
1884 * The data for this machine dependent, and the declarations are in machine
1885 * dependent code. The layout of intrnames and intrcnt however is machine
1886 * independent.
1887 *
1888 * We do not know the length of intrcnt and intrnames at compile time, so
1889 * calculate things at run time.
1890 */
1891 static int
sysctl_intrnames(SYSCTL_HANDLER_ARGS)1892 sysctl_intrnames(SYSCTL_HANDLER_ARGS)
1893 {
1894 return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req));
1895 }
1896
1897 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD,
1898 NULL, 0, sysctl_intrnames, "", "Interrupt Names");
1899
1900 static int
sysctl_intrcnt(SYSCTL_HANDLER_ARGS)1901 sysctl_intrcnt(SYSCTL_HANDLER_ARGS)
1902 {
1903 #ifdef SCTL_MASK32
1904 uint32_t *intrcnt32;
1905 unsigned i;
1906 int error;
1907
1908 if (req->flags & SCTL_MASK32) {
1909 if (!req->oldptr)
1910 return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req));
1911 intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT);
1912 if (intrcnt32 == NULL)
1913 return (ENOMEM);
1914 for (i = 0; i < sintrcnt / sizeof (u_long); i++)
1915 intrcnt32[i] = intrcnt[i];
1916 error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req);
1917 free(intrcnt32, M_TEMP);
1918 return (error);
1919 }
1920 #endif
1921 return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req));
1922 }
1923
1924 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD,
1925 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts");
1926
1927 #ifdef DDB
1928 /*
1929 * DDB command to dump the interrupt statistics.
1930 */
DB_SHOW_COMMAND(intrcnt,db_show_intrcnt)1931 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt)
1932 {
1933 u_long *i;
1934 char *cp;
1935 u_int j;
1936
1937 cp = intrnames;
1938 j = 0;
1939 for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit;
1940 i++, j++) {
1941 if (*cp == '\0')
1942 break;
1943 if (*i != 0)
1944 db_printf("%s\t%lu\n", cp, *i);
1945 cp += strlen(cp) + 1;
1946 }
1947 }
1948 #endif
1949