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