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