Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_intr.c
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1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1997, Stefan Esser <se@freebsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice unmodified, this list of conditions, and the following 12 * disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "opt_ddb.h" 33 #include "opt_kstack_usage_prof.h" 34 35 #include <sys/param.h> 36 #include <sys/bus.h> 37 #include <sys/conf.h> 38 #include <sys/cpuset.h> 39 #include <sys/rtprio.h> 40 #include <sys/systm.h> 41 #include <sys/interrupt.h> 42 #include <sys/kernel.h> 43 #include <sys/kthread.h> 44 #include <sys/ktr.h> 45 #include <sys/limits.h> 46 #include <sys/lock.h> 47 #include <sys/malloc.h> 48 #include <sys/mutex.h> 49 #include <sys/priv.h> 50 #include <sys/proc.h> 51 #include <sys/random.h> 52 #include <sys/resourcevar.h> 53 #include <sys/sched.h> 54 #include <sys/smp.h> 55 #include <sys/sysctl.h> 56 #include <sys/syslog.h> 57 #include <sys/unistd.h> 58 #include <sys/vmmeter.h> 59 #include <machine/atomic.h> 60 #include <machine/cpu.h> 61 #include <machine/md_var.h> 62 #include <machine/smp.h> 63 #include <machine/stdarg.h> 64 #ifdef DDB 65 #include <ddb/ddb.h> 66 #include <ddb/db_sym.h> 67 #endif 68 69 /* 70 * Describe an interrupt thread. There is one of these per interrupt event. 71 */ 72 struct intr_thread { 73 struct intr_event *it_event; 74 struct thread *it_thread; /* Kernel thread. */ 75 int it_flags; /* (j) IT_* flags. */ 76 int it_need; /* Needs service. */ 77 }; 78 79 /* Interrupt thread flags kept in it_flags */ 80 #define IT_DEAD 0x000001 /* Thread is waiting to exit. */ 81 #define IT_WAIT 0x000002 /* Thread is waiting for completion. */ 82 83 struct intr_entropy { 84 struct thread *td; 85 uintptr_t event; 86 }; 87 88 struct intr_event *clk_intr_event; 89 struct intr_event *tty_intr_event; 90 void *vm_ih; 91 struct proc *intrproc; 92 93 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads"); 94 95 static int intr_storm_threshold = 1000; 96 SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RWTUN, 97 &intr_storm_threshold, 0, 98 "Number of consecutive interrupts before storm protection is enabled"); 99 static TAILQ_HEAD(, intr_event) event_list = 100 TAILQ_HEAD_INITIALIZER(event_list); 101 static struct mtx event_lock; 102 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF); 103 104 static void intr_event_update(struct intr_event *ie); 105 static int intr_event_schedule_thread(struct intr_event *ie); 106 static struct intr_thread *ithread_create(const char *name); 107 static void ithread_destroy(struct intr_thread *ithread); 108 static void ithread_execute_handlers(struct proc *p, 109 struct intr_event *ie); 110 static void ithread_loop(void *); 111 static void ithread_update(struct intr_thread *ithd); 112 static void start_softintr(void *); 113 114 /* Map an interrupt type to an ithread priority. */ 115 u_char 116 intr_priority(enum intr_type flags) 117 { 118 u_char pri; 119 120 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET | 121 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV); 122 switch (flags) { 123 case INTR_TYPE_TTY: 124 pri = PI_TTY; 125 break; 126 case INTR_TYPE_BIO: 127 pri = PI_DISK; 128 break; 129 case INTR_TYPE_NET: 130 pri = PI_NET; 131 break; 132 case INTR_TYPE_CAM: 133 pri = PI_DISK; 134 break; 135 case INTR_TYPE_AV: 136 pri = PI_AV; 137 break; 138 case INTR_TYPE_CLK: 139 pri = PI_REALTIME; 140 break; 141 case INTR_TYPE_MISC: 142 pri = PI_DULL; /* don't care */ 143 break; 144 default: 145 /* We didn't specify an interrupt level. */ 146 panic("intr_priority: no interrupt type in flags"); 147 } 148 149 return pri; 150 } 151 152 /* 153 * Update an ithread based on the associated intr_event. 154 */ 155 static void 156 ithread_update(struct intr_thread *ithd) 157 { 158 struct intr_event *ie; 159 struct thread *td; 160 u_char pri; 161 162 ie = ithd->it_event; 163 td = ithd->it_thread; 164 mtx_assert(&ie->ie_lock, MA_OWNED); 165 166 /* Determine the overall priority of this event. */ 167 if (CK_SLIST_EMPTY(&ie->ie_handlers)) 168 pri = PRI_MAX_ITHD; 169 else 170 pri = CK_SLIST_FIRST(&ie->ie_handlers)->ih_pri; 171 172 /* Update name and priority. */ 173 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name)); 174 #ifdef KTR 175 sched_clear_tdname(td); 176 #endif 177 thread_lock(td); 178 sched_prio(td, pri); 179 thread_unlock(td); 180 } 181 182 /* 183 * Regenerate the full name of an interrupt event and update its priority. 184 */ 185 static void 186 intr_event_update(struct intr_event *ie) 187 { 188 struct intr_handler *ih; 189 char *last; 190 int missed, space; 191 192 /* Start off with no entropy and just the name of the event. */ 193 mtx_assert(&ie->ie_lock, MA_OWNED); 194 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 195 ie->ie_flags &= ~IE_ENTROPY; 196 missed = 0; 197 space = 1; 198 199 /* Run through all the handlers updating values. */ 200 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 201 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 < 202 sizeof(ie->ie_fullname)) { 203 strcat(ie->ie_fullname, " "); 204 strcat(ie->ie_fullname, ih->ih_name); 205 space = 0; 206 } else 207 missed++; 208 if (ih->ih_flags & IH_ENTROPY) 209 ie->ie_flags |= IE_ENTROPY; 210 } 211 212 /* 213 * If there is only one handler and its name is too long, just copy in 214 * as much of the end of the name (includes the unit number) as will 215 * fit. Otherwise, we have multiple handlers and not all of the names 216 * will fit. Add +'s to indicate missing names. If we run out of room 217 * and still have +'s to add, change the last character from a + to a *. 218 */ 219 if (missed == 1 && space == 1) { 220 ih = CK_SLIST_FIRST(&ie->ie_handlers); 221 missed = strlen(ie->ie_fullname) + strlen(ih->ih_name) + 2 - 222 sizeof(ie->ie_fullname); 223 strcat(ie->ie_fullname, (missed == 0) ? " " : "-"); 224 strcat(ie->ie_fullname, &ih->ih_name[missed]); 225 missed = 0; 226 } 227 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2]; 228 while (missed-- > 0) { 229 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) { 230 if (*last == '+') { 231 *last = '*'; 232 break; 233 } else 234 *last = '+'; 235 } else if (space) { 236 strcat(ie->ie_fullname, " +"); 237 space = 0; 238 } else 239 strcat(ie->ie_fullname, "+"); 240 } 241 242 /* 243 * If this event has an ithread, update it's priority and 244 * name. 245 */ 246 if (ie->ie_thread != NULL) 247 ithread_update(ie->ie_thread); 248 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname); 249 } 250 251 int 252 intr_event_create(struct intr_event **event, void *source, int flags, int irq, 253 void (*pre_ithread)(void *), void (*post_ithread)(void *), 254 void (*post_filter)(void *), int (*assign_cpu)(void *, int), 255 const char *fmt, ...) 256 { 257 struct intr_event *ie; 258 va_list ap; 259 260 /* The only valid flag during creation is IE_SOFT. */ 261 if ((flags & ~IE_SOFT) != 0) 262 return (EINVAL); 263 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO); 264 ie->ie_source = source; 265 ie->ie_pre_ithread = pre_ithread; 266 ie->ie_post_ithread = post_ithread; 267 ie->ie_post_filter = post_filter; 268 ie->ie_assign_cpu = assign_cpu; 269 ie->ie_flags = flags; 270 ie->ie_irq = irq; 271 ie->ie_cpu = NOCPU; 272 CK_SLIST_INIT(&ie->ie_handlers); 273 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF); 274 275 va_start(ap, fmt); 276 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap); 277 va_end(ap); 278 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 279 mtx_lock(&event_lock); 280 TAILQ_INSERT_TAIL(&event_list, ie, ie_list); 281 mtx_unlock(&event_lock); 282 if (event != NULL) 283 *event = ie; 284 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name); 285 return (0); 286 } 287 288 /* 289 * Bind an interrupt event to the specified CPU. Note that not all 290 * platforms support binding an interrupt to a CPU. For those 291 * platforms this request will fail. Using a cpu id of NOCPU unbinds 292 * the interrupt event. 293 */ 294 static int 295 _intr_event_bind(struct intr_event *ie, int cpu, bool bindirq, bool bindithread) 296 { 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 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR); 308 if (error) 309 return (error); 310 311 /* 312 * If we have any ithreads try to set their mask first to verify 313 * permissions, etc. 314 */ 315 if (bindithread) { 316 mtx_lock(&ie->ie_lock); 317 if (ie->ie_thread != NULL) { 318 id = ie->ie_thread->it_thread->td_tid; 319 mtx_unlock(&ie->ie_lock); 320 error = cpuset_setithread(id, cpu); 321 if (error) 322 return (error); 323 } else 324 mtx_unlock(&ie->ie_lock); 325 } 326 if (bindirq) 327 error = ie->ie_assign_cpu(ie->ie_source, cpu); 328 if (error) { 329 if (bindithread) { 330 mtx_lock(&ie->ie_lock); 331 if (ie->ie_thread != NULL) { 332 cpu = ie->ie_cpu; 333 id = ie->ie_thread->it_thread->td_tid; 334 mtx_unlock(&ie->ie_lock); 335 (void)cpuset_setithread(id, cpu); 336 } else 337 mtx_unlock(&ie->ie_lock); 338 } 339 return (error); 340 } 341 342 if (bindirq) { 343 mtx_lock(&ie->ie_lock); 344 ie->ie_cpu = cpu; 345 mtx_unlock(&ie->ie_lock); 346 } 347 348 return (error); 349 } 350 351 /* 352 * Bind an interrupt event to the specified CPU. For supported platforms, any 353 * associated ithreads as well as the primary interrupt context will be bound 354 * to the specificed CPU. 355 */ 356 int 357 intr_event_bind(struct intr_event *ie, int cpu) 358 { 359 360 return (_intr_event_bind(ie, cpu, true, true)); 361 } 362 363 /* 364 * Bind an interrupt event to the specified CPU, but do not bind associated 365 * ithreads. 366 */ 367 int 368 intr_event_bind_irqonly(struct intr_event *ie, int cpu) 369 { 370 371 return (_intr_event_bind(ie, cpu, true, false)); 372 } 373 374 /* 375 * Bind an interrupt event's ithread to the specified CPU. 376 */ 377 int 378 intr_event_bind_ithread(struct intr_event *ie, int cpu) 379 { 380 381 return (_intr_event_bind(ie, cpu, false, true)); 382 } 383 384 static struct intr_event * 385 intr_lookup(int irq) 386 { 387 struct intr_event *ie; 388 389 mtx_lock(&event_lock); 390 TAILQ_FOREACH(ie, &event_list, ie_list) 391 if (ie->ie_irq == irq && 392 (ie->ie_flags & IE_SOFT) == 0 && 393 CK_SLIST_FIRST(&ie->ie_handlers) != NULL) 394 break; 395 mtx_unlock(&event_lock); 396 return (ie); 397 } 398 399 int 400 intr_setaffinity(int irq, int mode, void *m) 401 { 402 struct intr_event *ie; 403 cpuset_t *mask; 404 int cpu, n; 405 406 mask = m; 407 cpu = NOCPU; 408 /* 409 * If we're setting all cpus we can unbind. Otherwise make sure 410 * only one cpu is in the set. 411 */ 412 if (CPU_CMP(cpuset_root, mask)) { 413 for (n = 0; n < CPU_SETSIZE; n++) { 414 if (!CPU_ISSET(n, mask)) 415 continue; 416 if (cpu != NOCPU) 417 return (EINVAL); 418 cpu = n; 419 } 420 } 421 ie = intr_lookup(irq); 422 if (ie == NULL) 423 return (ESRCH); 424 switch (mode) { 425 case CPU_WHICH_IRQ: 426 return (intr_event_bind(ie, cpu)); 427 case CPU_WHICH_INTRHANDLER: 428 return (intr_event_bind_irqonly(ie, cpu)); 429 case CPU_WHICH_ITHREAD: 430 return (intr_event_bind_ithread(ie, cpu)); 431 default: 432 return (EINVAL); 433 } 434 } 435 436 int 437 intr_getaffinity(int irq, int mode, void *m) 438 { 439 struct intr_event *ie; 440 struct thread *td; 441 struct proc *p; 442 cpuset_t *mask; 443 lwpid_t id; 444 int error; 445 446 mask = m; 447 ie = intr_lookup(irq); 448 if (ie == NULL) 449 return (ESRCH); 450 451 error = 0; 452 CPU_ZERO(mask); 453 switch (mode) { 454 case CPU_WHICH_IRQ: 455 case CPU_WHICH_INTRHANDLER: 456 mtx_lock(&ie->ie_lock); 457 if (ie->ie_cpu == NOCPU) 458 CPU_COPY(cpuset_root, mask); 459 else 460 CPU_SET(ie->ie_cpu, mask); 461 mtx_unlock(&ie->ie_lock); 462 break; 463 case CPU_WHICH_ITHREAD: 464 mtx_lock(&ie->ie_lock); 465 if (ie->ie_thread == NULL) { 466 mtx_unlock(&ie->ie_lock); 467 CPU_COPY(cpuset_root, mask); 468 } else { 469 id = ie->ie_thread->it_thread->td_tid; 470 mtx_unlock(&ie->ie_lock); 471 error = cpuset_which(CPU_WHICH_TID, id, &p, &td, NULL); 472 if (error != 0) 473 return (error); 474 CPU_COPY(&td->td_cpuset->cs_mask, mask); 475 PROC_UNLOCK(p); 476 } 477 default: 478 return (EINVAL); 479 } 480 return (0); 481 } 482 483 int 484 intr_event_destroy(struct intr_event *ie) 485 { 486 487 mtx_lock(&event_lock); 488 mtx_lock(&ie->ie_lock); 489 if (!CK_SLIST_EMPTY(&ie->ie_handlers)) { 490 mtx_unlock(&ie->ie_lock); 491 mtx_unlock(&event_lock); 492 return (EBUSY); 493 } 494 TAILQ_REMOVE(&event_list, ie, ie_list); 495 #ifndef notyet 496 if (ie->ie_thread != NULL) { 497 ithread_destroy(ie->ie_thread); 498 ie->ie_thread = NULL; 499 } 500 #endif 501 mtx_unlock(&ie->ie_lock); 502 mtx_unlock(&event_lock); 503 mtx_destroy(&ie->ie_lock); 504 free(ie, M_ITHREAD); 505 return (0); 506 } 507 508 static struct intr_thread * 509 ithread_create(const char *name) 510 { 511 struct intr_thread *ithd; 512 struct thread *td; 513 int error; 514 515 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 516 517 error = kproc_kthread_add(ithread_loop, ithd, &intrproc, 518 &td, RFSTOPPED | RFHIGHPID, 519 0, "intr", "%s", name); 520 if (error) 521 panic("kproc_create() failed with %d", error); 522 thread_lock(td); 523 sched_class(td, PRI_ITHD); 524 TD_SET_IWAIT(td); 525 thread_unlock(td); 526 td->td_pflags |= TDP_ITHREAD; 527 ithd->it_thread = td; 528 CTR2(KTR_INTR, "%s: created %s", __func__, name); 529 return (ithd); 530 } 531 532 static void 533 ithread_destroy(struct intr_thread *ithread) 534 { 535 struct thread *td; 536 537 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name); 538 td = ithread->it_thread; 539 thread_lock(td); 540 ithread->it_flags |= IT_DEAD; 541 if (TD_AWAITING_INTR(td)) { 542 TD_CLR_IWAIT(td); 543 sched_add(td, SRQ_INTR); 544 } 545 thread_unlock(td); 546 } 547 548 int 549 intr_event_add_handler(struct intr_event *ie, const char *name, 550 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 551 enum intr_type flags, void **cookiep) 552 { 553 struct intr_handler *ih, *temp_ih; 554 struct intr_handler **prevptr; 555 struct intr_thread *it; 556 557 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 558 return (EINVAL); 559 560 /* Allocate and populate an interrupt handler structure. */ 561 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 562 ih->ih_filter = filter; 563 ih->ih_handler = handler; 564 ih->ih_argument = arg; 565 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 566 ih->ih_event = ie; 567 ih->ih_pri = pri; 568 if (flags & INTR_EXCL) 569 ih->ih_flags = IH_EXCLUSIVE; 570 if (flags & INTR_MPSAFE) 571 ih->ih_flags |= IH_MPSAFE; 572 if (flags & INTR_ENTROPY) 573 ih->ih_flags |= IH_ENTROPY; 574 575 /* We can only have one exclusive handler in a event. */ 576 mtx_lock(&ie->ie_lock); 577 if (!CK_SLIST_EMPTY(&ie->ie_handlers)) { 578 if ((flags & INTR_EXCL) || 579 (CK_SLIST_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 580 mtx_unlock(&ie->ie_lock); 581 free(ih, M_ITHREAD); 582 return (EINVAL); 583 } 584 } 585 586 /* Create a thread if we need one. */ 587 while (ie->ie_thread == NULL && handler != NULL) { 588 if (ie->ie_flags & IE_ADDING_THREAD) 589 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 590 else { 591 ie->ie_flags |= IE_ADDING_THREAD; 592 mtx_unlock(&ie->ie_lock); 593 it = ithread_create("intr: newborn"); 594 mtx_lock(&ie->ie_lock); 595 ie->ie_flags &= ~IE_ADDING_THREAD; 596 ie->ie_thread = it; 597 it->it_event = ie; 598 ithread_update(it); 599 wakeup(ie); 600 } 601 } 602 603 /* Add the new handler to the event in priority order. */ 604 CK_SLIST_FOREACH_PREVPTR(temp_ih, prevptr, &ie->ie_handlers, ih_next) { 605 if (temp_ih->ih_pri > ih->ih_pri) 606 break; 607 } 608 CK_SLIST_INSERT_PREVPTR(prevptr, temp_ih, ih, ih_next); 609 610 intr_event_update(ie); 611 612 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 613 ie->ie_name); 614 mtx_unlock(&ie->ie_lock); 615 616 if (cookiep != NULL) 617 *cookiep = ih; 618 return (0); 619 } 620 621 /* 622 * Append a description preceded by a ':' to the name of the specified 623 * interrupt handler. 624 */ 625 int 626 intr_event_describe_handler(struct intr_event *ie, void *cookie, 627 const char *descr) 628 { 629 struct intr_handler *ih; 630 size_t space; 631 char *start; 632 633 mtx_lock(&ie->ie_lock); 634 #ifdef INVARIANTS 635 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 636 if (ih == cookie) 637 break; 638 } 639 if (ih == NULL) { 640 mtx_unlock(&ie->ie_lock); 641 panic("handler %p not found in interrupt event %p", cookie, ie); 642 } 643 #endif 644 ih = cookie; 645 646 /* 647 * Look for an existing description by checking for an 648 * existing ":". This assumes device names do not include 649 * colons. If one is found, prepare to insert the new 650 * description at that point. If one is not found, find the 651 * end of the name to use as the insertion point. 652 */ 653 start = strchr(ih->ih_name, ':'); 654 if (start == NULL) 655 start = strchr(ih->ih_name, 0); 656 657 /* 658 * See if there is enough remaining room in the string for the 659 * description + ":". The "- 1" leaves room for the trailing 660 * '\0'. The "+ 1" accounts for the colon. 661 */ 662 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1; 663 if (strlen(descr) + 1 > space) { 664 mtx_unlock(&ie->ie_lock); 665 return (ENOSPC); 666 } 667 668 /* Append a colon followed by the description. */ 669 *start = ':'; 670 strcpy(start + 1, descr); 671 intr_event_update(ie); 672 mtx_unlock(&ie->ie_lock); 673 return (0); 674 } 675 676 /* 677 * Return the ie_source field from the intr_event an intr_handler is 678 * associated with. 679 */ 680 void * 681 intr_handler_source(void *cookie) 682 { 683 struct intr_handler *ih; 684 struct intr_event *ie; 685 686 ih = (struct intr_handler *)cookie; 687 if (ih == NULL) 688 return (NULL); 689 ie = ih->ih_event; 690 KASSERT(ie != NULL, 691 ("interrupt handler \"%s\" has a NULL interrupt event", 692 ih->ih_name)); 693 return (ie->ie_source); 694 } 695 696 /* 697 * If intr_event_handle() is running in the ISR context at the time of the call, 698 * then wait for it to complete. 699 */ 700 static void 701 intr_event_barrier(struct intr_event *ie) 702 { 703 int phase; 704 705 mtx_assert(&ie->ie_lock, MA_OWNED); 706 phase = ie->ie_phase; 707 708 /* 709 * Switch phase to direct future interrupts to the other active counter. 710 * Make sure that any preceding stores are visible before the switch. 711 */ 712 KASSERT(ie->ie_active[!phase] == 0, ("idle phase has activity")); 713 atomic_store_rel_int(&ie->ie_phase, !phase); 714 715 /* 716 * This code cooperates with wait-free iteration of ie_handlers 717 * in intr_event_handle. 718 * Make sure that the removal and the phase update are not reordered 719 * with the active count check. 720 * Note that no combination of acquire and release fences can provide 721 * that guarantee as Store->Load sequences can always be reordered. 722 */ 723 atomic_thread_fence_seq_cst(); 724 725 /* 726 * Now wait on the inactive phase. 727 * The acquire fence is needed so that all post-barrier accesses 728 * are after the check. 729 */ 730 while (ie->ie_active[phase] > 0) 731 cpu_spinwait(); 732 atomic_thread_fence_acq(); 733 } 734 735 static void 736 intr_handler_barrier(struct intr_handler *handler) 737 { 738 struct intr_event *ie; 739 740 ie = handler->ih_event; 741 mtx_assert(&ie->ie_lock, MA_OWNED); 742 KASSERT((handler->ih_flags & IH_DEAD) == 0, 743 ("update for a removed handler")); 744 745 if (ie->ie_thread == NULL) { 746 intr_event_barrier(ie); 747 return; 748 } 749 if ((handler->ih_flags & IH_CHANGED) == 0) { 750 handler->ih_flags |= IH_CHANGED; 751 intr_event_schedule_thread(ie); 752 } 753 while ((handler->ih_flags & IH_CHANGED) != 0) 754 msleep(handler, &ie->ie_lock, 0, "ih_barr", 0); 755 } 756 757 /* 758 * Sleep until an ithread finishes executing an interrupt handler. 759 * 760 * XXX Doesn't currently handle interrupt filters or fast interrupt 761 * handlers. This is intended for LinuxKPI drivers only. 762 * Do not use in BSD code. 763 */ 764 void 765 _intr_drain(int irq) 766 { 767 struct intr_event *ie; 768 struct intr_thread *ithd; 769 struct thread *td; 770 771 ie = intr_lookup(irq); 772 if (ie == NULL) 773 return; 774 if (ie->ie_thread == NULL) 775 return; 776 ithd = ie->ie_thread; 777 td = ithd->it_thread; 778 /* 779 * We set the flag and wait for it to be cleared to avoid 780 * long delays with potentially busy interrupt handlers 781 * were we to only sample TD_AWAITING_INTR() every tick. 782 */ 783 thread_lock(td); 784 if (!TD_AWAITING_INTR(td)) { 785 ithd->it_flags |= IT_WAIT; 786 while (ithd->it_flags & IT_WAIT) { 787 thread_unlock(td); 788 pause("idrain", 1); 789 thread_lock(td); 790 } 791 } 792 thread_unlock(td); 793 return; 794 } 795 796 int 797 intr_event_remove_handler(void *cookie) 798 { 799 struct intr_handler *handler = (struct intr_handler *)cookie; 800 struct intr_event *ie; 801 struct intr_handler *ih; 802 struct intr_handler **prevptr; 803 #ifdef notyet 804 int dead; 805 #endif 806 807 if (handler == NULL) 808 return (EINVAL); 809 ie = handler->ih_event; 810 KASSERT(ie != NULL, 811 ("interrupt handler \"%s\" has a NULL interrupt event", 812 handler->ih_name)); 813 814 mtx_lock(&ie->ie_lock); 815 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 816 ie->ie_name); 817 CK_SLIST_FOREACH_PREVPTR(ih, prevptr, &ie->ie_handlers, ih_next) { 818 if (ih == handler) 819 break; 820 } 821 if (ih == NULL) { 822 panic("interrupt handler \"%s\" not found in " 823 "interrupt event \"%s\"", handler->ih_name, ie->ie_name); 824 } 825 826 /* 827 * If there is no ithread, then directly remove the handler. Note that 828 * intr_event_handle() iterates ie_handlers in a lock-less fashion, so 829 * care needs to be taken to keep ie_handlers consistent and to free 830 * the removed handler only when ie_handlers is quiescent. 831 */ 832 if (ie->ie_thread == NULL) { 833 CK_SLIST_REMOVE_PREVPTR(prevptr, ih, ih_next); 834 intr_event_barrier(ie); 835 intr_event_update(ie); 836 mtx_unlock(&ie->ie_lock); 837 free(handler, M_ITHREAD); 838 return (0); 839 } 840 841 /* 842 * Let the interrupt thread do the job. 843 * The interrupt source is disabled when the interrupt thread is 844 * running, so it does not have to worry about interaction with 845 * intr_event_handle(). 846 */ 847 KASSERT((handler->ih_flags & IH_DEAD) == 0, 848 ("duplicate handle remove")); 849 handler->ih_flags |= IH_DEAD; 850 intr_event_schedule_thread(ie); 851 while (handler->ih_flags & IH_DEAD) 852 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 853 intr_event_update(ie); 854 855 #ifdef notyet 856 /* 857 * XXX: This could be bad in the case of ppbus(8). Also, I think 858 * this could lead to races of stale data when servicing an 859 * interrupt. 860 */ 861 dead = 1; 862 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 863 if (ih->ih_handler != NULL) { 864 dead = 0; 865 break; 866 } 867 } 868 if (dead) { 869 ithread_destroy(ie->ie_thread); 870 ie->ie_thread = NULL; 871 } 872 #endif 873 mtx_unlock(&ie->ie_lock); 874 free(handler, M_ITHREAD); 875 return (0); 876 } 877 878 int 879 intr_event_suspend_handler(void *cookie) 880 { 881 struct intr_handler *handler = (struct intr_handler *)cookie; 882 struct intr_event *ie; 883 884 if (handler == NULL) 885 return (EINVAL); 886 ie = handler->ih_event; 887 KASSERT(ie != NULL, 888 ("interrupt handler \"%s\" has a NULL interrupt event", 889 handler->ih_name)); 890 mtx_lock(&ie->ie_lock); 891 handler->ih_flags |= IH_SUSP; 892 intr_handler_barrier(handler); 893 mtx_unlock(&ie->ie_lock); 894 return (0); 895 } 896 897 int 898 intr_event_resume_handler(void *cookie) 899 { 900 struct intr_handler *handler = (struct intr_handler *)cookie; 901 struct intr_event *ie; 902 903 if (handler == NULL) 904 return (EINVAL); 905 ie = handler->ih_event; 906 KASSERT(ie != NULL, 907 ("interrupt handler \"%s\" has a NULL interrupt event", 908 handler->ih_name)); 909 910 /* 911 * intr_handler_barrier() acts not only as a barrier, 912 * it also allows to check for any pending interrupts. 913 */ 914 mtx_lock(&ie->ie_lock); 915 handler->ih_flags &= ~IH_SUSP; 916 intr_handler_barrier(handler); 917 mtx_unlock(&ie->ie_lock); 918 return (0); 919 } 920 921 static int 922 intr_event_schedule_thread(struct intr_event *ie) 923 { 924 struct intr_entropy entropy; 925 struct intr_thread *it; 926 struct thread *td; 927 struct thread *ctd; 928 929 /* 930 * If no ithread or no handlers, then we have a stray interrupt. 931 */ 932 if (ie == NULL || CK_SLIST_EMPTY(&ie->ie_handlers) || 933 ie->ie_thread == NULL) 934 return (EINVAL); 935 936 ctd = curthread; 937 it = ie->ie_thread; 938 td = it->it_thread; 939 940 /* 941 * If any of the handlers for this ithread claim to be good 942 * sources of entropy, then gather some. 943 */ 944 if (ie->ie_flags & IE_ENTROPY) { 945 entropy.event = (uintptr_t)ie; 946 entropy.td = ctd; 947 random_harvest_queue(&entropy, sizeof(entropy), RANDOM_INTERRUPT); 948 } 949 950 KASSERT(td->td_proc != NULL, ("ithread %s has no process", ie->ie_name)); 951 952 /* 953 * Set it_need to tell the thread to keep running if it is already 954 * running. Then, lock the thread and see if we actually need to 955 * put it on the runqueue. 956 * 957 * Use store_rel to arrange that the store to ih_need in 958 * swi_sched() is before the store to it_need and prepare for 959 * transfer of this order to loads in the ithread. 960 */ 961 atomic_store_rel_int(&it->it_need, 1); 962 thread_lock(td); 963 if (TD_AWAITING_INTR(td)) { 964 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, td->td_proc->p_pid, 965 td->td_name); 966 TD_CLR_IWAIT(td); 967 sched_add(td, SRQ_INTR); 968 } else { 969 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 970 __func__, td->td_proc->p_pid, td->td_name, it->it_need, td->td_state); 971 } 972 thread_unlock(td); 973 974 return (0); 975 } 976 977 /* 978 * Allow interrupt event binding for software interrupt handlers -- a no-op, 979 * since interrupts are generated in software rather than being directed by 980 * a PIC. 981 */ 982 static int 983 swi_assign_cpu(void *arg, int cpu) 984 { 985 986 return (0); 987 } 988 989 /* 990 * Add a software interrupt handler to a specified event. If a given event 991 * is not specified, then a new event is created. 992 */ 993 int 994 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler, 995 void *arg, int pri, enum intr_type flags, void **cookiep) 996 { 997 struct intr_event *ie; 998 int error = 0; 999 1000 if (flags & INTR_ENTROPY) 1001 return (EINVAL); 1002 1003 ie = (eventp != NULL) ? *eventp : NULL; 1004 1005 if (ie != NULL) { 1006 if (!(ie->ie_flags & IE_SOFT)) 1007 return (EINVAL); 1008 } else { 1009 error = intr_event_create(&ie, NULL, IE_SOFT, 0, 1010 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri); 1011 if (error) 1012 return (error); 1013 if (eventp != NULL) 1014 *eventp = ie; 1015 } 1016 if (handler != NULL) { 1017 error = intr_event_add_handler(ie, name, NULL, handler, arg, 1018 PI_SWI(pri), flags, cookiep); 1019 } 1020 return (error); 1021 } 1022 1023 /* 1024 * Schedule a software interrupt thread. 1025 */ 1026 void 1027 swi_sched(void *cookie, int flags) 1028 { 1029 struct intr_handler *ih = (struct intr_handler *)cookie; 1030 struct intr_event *ie = ih->ih_event; 1031 struct intr_entropy entropy; 1032 int error __unused; 1033 1034 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name, 1035 ih->ih_need); 1036 1037 if ((flags & SWI_FROMNMI) == 0) { 1038 entropy.event = (uintptr_t)ih; 1039 entropy.td = curthread; 1040 random_harvest_queue(&entropy, sizeof(entropy), RANDOM_SWI); 1041 } 1042 1043 /* 1044 * Set ih_need for this handler so that if the ithread is already 1045 * running it will execute this handler on the next pass. Otherwise, 1046 * it will execute it the next time it runs. 1047 */ 1048 ih->ih_need = 1; 1049 1050 if (flags & SWI_DELAY) 1051 return; 1052 1053 if (flags & SWI_FROMNMI) { 1054 #if defined(SMP) && (defined(__i386__) || defined(__amd64__)) 1055 KASSERT(ie == clk_intr_event, 1056 ("SWI_FROMNMI used not with clk_intr_event")); 1057 ipi_self_from_nmi(IPI_SWI); 1058 #endif 1059 } else { 1060 VM_CNT_INC(v_soft); 1061 error = intr_event_schedule_thread(ie); 1062 KASSERT(error == 0, ("stray software interrupt")); 1063 } 1064 } 1065 1066 /* 1067 * Remove a software interrupt handler. Currently this code does not 1068 * remove the associated interrupt event if it becomes empty. Calling code 1069 * may do so manually via intr_event_destroy(), but that's not really 1070 * an optimal interface. 1071 */ 1072 int 1073 swi_remove(void *cookie) 1074 { 1075 1076 return (intr_event_remove_handler(cookie)); 1077 } 1078 1079 static void 1080 intr_event_execute_handlers(struct proc *p, struct intr_event *ie) 1081 { 1082 struct intr_handler *ih, *ihn, *ihp; 1083 1084 ihp = NULL; 1085 CK_SLIST_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) { 1086 /* 1087 * If this handler is marked for death, remove it from 1088 * the list of handlers and wake up the sleeper. 1089 */ 1090 if (ih->ih_flags & IH_DEAD) { 1091 mtx_lock(&ie->ie_lock); 1092 if (ihp == NULL) 1093 CK_SLIST_REMOVE_HEAD(&ie->ie_handlers, ih_next); 1094 else 1095 CK_SLIST_REMOVE_AFTER(ihp, ih_next); 1096 ih->ih_flags &= ~IH_DEAD; 1097 wakeup(ih); 1098 mtx_unlock(&ie->ie_lock); 1099 continue; 1100 } 1101 1102 /* 1103 * Now that we know that the current element won't be removed 1104 * update the previous element. 1105 */ 1106 ihp = ih; 1107 1108 if ((ih->ih_flags & IH_CHANGED) != 0) { 1109 mtx_lock(&ie->ie_lock); 1110 ih->ih_flags &= ~IH_CHANGED; 1111 wakeup(ih); 1112 mtx_unlock(&ie->ie_lock); 1113 } 1114 1115 /* Skip filter only handlers */ 1116 if (ih->ih_handler == NULL) 1117 continue; 1118 1119 /* Skip suspended handlers */ 1120 if ((ih->ih_flags & IH_SUSP) != 0) 1121 continue; 1122 1123 /* 1124 * For software interrupt threads, we only execute 1125 * handlers that have their need flag set. Hardware 1126 * interrupt threads always invoke all of their handlers. 1127 * 1128 * ih_need can only be 0 or 1. Failed cmpset below 1129 * means that there is no request to execute handlers, 1130 * so a retry of the cmpset is not needed. 1131 */ 1132 if ((ie->ie_flags & IE_SOFT) != 0 && 1133 atomic_cmpset_int(&ih->ih_need, 1, 0) == 0) 1134 continue; 1135 1136 /* Execute this handler. */ 1137 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1138 __func__, p->p_pid, (void *)ih->ih_handler, 1139 ih->ih_argument, ih->ih_name, ih->ih_flags); 1140 1141 if (!(ih->ih_flags & IH_MPSAFE)) 1142 mtx_lock(&Giant); 1143 ih->ih_handler(ih->ih_argument); 1144 if (!(ih->ih_flags & IH_MPSAFE)) 1145 mtx_unlock(&Giant); 1146 } 1147 } 1148 1149 static void 1150 ithread_execute_handlers(struct proc *p, struct intr_event *ie) 1151 { 1152 1153 /* Interrupt handlers should not sleep. */ 1154 if (!(ie->ie_flags & IE_SOFT)) 1155 THREAD_NO_SLEEPING(); 1156 intr_event_execute_handlers(p, ie); 1157 if (!(ie->ie_flags & IE_SOFT)) 1158 THREAD_SLEEPING_OK(); 1159 1160 /* 1161 * Interrupt storm handling: 1162 * 1163 * If this interrupt source is currently storming, then throttle 1164 * it to only fire the handler once per clock tick. 1165 * 1166 * If this interrupt source is not currently storming, but the 1167 * number of back to back interrupts exceeds the storm threshold, 1168 * then enter storming mode. 1169 */ 1170 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold && 1171 !(ie->ie_flags & IE_SOFT)) { 1172 /* Report the message only once every second. */ 1173 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) { 1174 printf( 1175 "interrupt storm detected on \"%s\"; throttling interrupt source\n", 1176 ie->ie_name); 1177 } 1178 pause("istorm", 1); 1179 } else 1180 ie->ie_count++; 1181 1182 /* 1183 * Now that all the handlers have had a chance to run, reenable 1184 * the interrupt source. 1185 */ 1186 if (ie->ie_post_ithread != NULL) 1187 ie->ie_post_ithread(ie->ie_source); 1188 } 1189 1190 /* 1191 * This is the main code for interrupt threads. 1192 */ 1193 static void 1194 ithread_loop(void *arg) 1195 { 1196 struct intr_thread *ithd; 1197 struct intr_event *ie; 1198 struct thread *td; 1199 struct proc *p; 1200 int wake; 1201 1202 td = curthread; 1203 p = td->td_proc; 1204 ithd = (struct intr_thread *)arg; 1205 KASSERT(ithd->it_thread == td, 1206 ("%s: ithread and proc linkage out of sync", __func__)); 1207 ie = ithd->it_event; 1208 ie->ie_count = 0; 1209 wake = 0; 1210 1211 /* 1212 * As long as we have interrupts outstanding, go through the 1213 * list of handlers, giving each one a go at it. 1214 */ 1215 for (;;) { 1216 /* 1217 * If we are an orphaned thread, then just die. 1218 */ 1219 if (ithd->it_flags & IT_DEAD) { 1220 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1221 p->p_pid, td->td_name); 1222 free(ithd, M_ITHREAD); 1223 kthread_exit(); 1224 } 1225 1226 /* 1227 * Service interrupts. If another interrupt arrives while 1228 * we are running, it will set it_need to note that we 1229 * should make another pass. 1230 * 1231 * The load_acq part of the following cmpset ensures 1232 * that the load of ih_need in ithread_execute_handlers() 1233 * is ordered after the load of it_need here. 1234 */ 1235 while (atomic_cmpset_acq_int(&ithd->it_need, 1, 0) != 0) 1236 ithread_execute_handlers(p, ie); 1237 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1238 mtx_assert(&Giant, MA_NOTOWNED); 1239 1240 /* 1241 * Processed all our interrupts. Now get the sched 1242 * lock. This may take a while and it_need may get 1243 * set again, so we have to check it again. 1244 */ 1245 thread_lock(td); 1246 if (atomic_load_acq_int(&ithd->it_need) == 0 && 1247 (ithd->it_flags & (IT_DEAD | IT_WAIT)) == 0) { 1248 TD_SET_IWAIT(td); 1249 ie->ie_count = 0; 1250 mi_switch(SW_VOL | SWT_IWAIT, NULL); 1251 } 1252 if (ithd->it_flags & IT_WAIT) { 1253 wake = 1; 1254 ithd->it_flags &= ~IT_WAIT; 1255 } 1256 thread_unlock(td); 1257 if (wake) { 1258 wakeup(ithd); 1259 wake = 0; 1260 } 1261 } 1262 } 1263 1264 /* 1265 * Main interrupt handling body. 1266 * 1267 * Input: 1268 * o ie: the event connected to this interrupt. 1269 * o frame: some archs (i.e. i386) pass a frame to some. 1270 * handlers as their main argument. 1271 * Return value: 1272 * o 0: everything ok. 1273 * o EINVAL: stray interrupt. 1274 */ 1275 int 1276 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1277 { 1278 struct intr_handler *ih; 1279 struct trapframe *oldframe; 1280 struct thread *td; 1281 int phase; 1282 int ret; 1283 bool filter, thread; 1284 1285 td = curthread; 1286 1287 #ifdef KSTACK_USAGE_PROF 1288 intr_prof_stack_use(td, frame); 1289 #endif 1290 1291 /* An interrupt with no event or handlers is a stray interrupt. */ 1292 if (ie == NULL || CK_SLIST_EMPTY(&ie->ie_handlers)) 1293 return (EINVAL); 1294 1295 /* 1296 * Execute fast interrupt handlers directly. 1297 * To support clock handlers, if a handler registers 1298 * with a NULL argument, then we pass it a pointer to 1299 * a trapframe as its argument. 1300 */ 1301 td->td_intr_nesting_level++; 1302 filter = false; 1303 thread = false; 1304 ret = 0; 1305 critical_enter(); 1306 oldframe = td->td_intr_frame; 1307 td->td_intr_frame = frame; 1308 1309 phase = ie->ie_phase; 1310 atomic_add_int(&ie->ie_active[phase], 1); 1311 1312 /* 1313 * This fence is required to ensure that no later loads are 1314 * re-ordered before the ie_active store. 1315 */ 1316 atomic_thread_fence_seq_cst(); 1317 1318 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 1319 if ((ih->ih_flags & IH_SUSP) != 0) 1320 continue; 1321 if ((ie->ie_flags & IE_SOFT) != 0 && ih->ih_need == 0) 1322 continue; 1323 if (ih->ih_filter == NULL) { 1324 thread = true; 1325 continue; 1326 } 1327 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__, 1328 ih->ih_filter, ih->ih_argument == NULL ? frame : 1329 ih->ih_argument, ih->ih_name); 1330 if (ih->ih_argument == NULL) 1331 ret = ih->ih_filter(frame); 1332 else 1333 ret = ih->ih_filter(ih->ih_argument); 1334 KASSERT(ret == FILTER_STRAY || 1335 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1336 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1337 ("%s: incorrect return value %#x from %s", __func__, ret, 1338 ih->ih_name)); 1339 filter = filter || ret == FILTER_HANDLED; 1340 1341 /* 1342 * Wrapper handler special handling: 1343 * 1344 * in some particular cases (like pccard and pccbb), 1345 * the _real_ device handler is wrapped in a couple of 1346 * functions - a filter wrapper and an ithread wrapper. 1347 * In this case (and just in this case), the filter wrapper 1348 * could ask the system to schedule the ithread and mask 1349 * the interrupt source if the wrapped handler is composed 1350 * of just an ithread handler. 1351 * 1352 * TODO: write a generic wrapper to avoid people rolling 1353 * their own. 1354 */ 1355 if (!thread) { 1356 if (ret == FILTER_SCHEDULE_THREAD) 1357 thread = true; 1358 } 1359 } 1360 atomic_add_rel_int(&ie->ie_active[phase], -1); 1361 1362 td->td_intr_frame = oldframe; 1363 1364 if (thread) { 1365 if (ie->ie_pre_ithread != NULL) 1366 ie->ie_pre_ithread(ie->ie_source); 1367 } else { 1368 if (ie->ie_post_filter != NULL) 1369 ie->ie_post_filter(ie->ie_source); 1370 } 1371 1372 /* Schedule the ithread if needed. */ 1373 if (thread) { 1374 int error __unused; 1375 1376 error = intr_event_schedule_thread(ie); 1377 KASSERT(error == 0, ("bad stray interrupt")); 1378 } 1379 critical_exit(); 1380 td->td_intr_nesting_level--; 1381 #ifdef notyet 1382 /* The interrupt is not aknowledged by any filter and has no ithread. */ 1383 if (!thread && !filter) 1384 return (EINVAL); 1385 #endif 1386 return (0); 1387 } 1388 1389 #ifdef DDB 1390 /* 1391 * Dump details about an interrupt handler 1392 */ 1393 static void 1394 db_dump_intrhand(struct intr_handler *ih) 1395 { 1396 int comma; 1397 1398 db_printf("\t%-10s ", ih->ih_name); 1399 switch (ih->ih_pri) { 1400 case PI_REALTIME: 1401 db_printf("CLK "); 1402 break; 1403 case PI_AV: 1404 db_printf("AV "); 1405 break; 1406 case PI_TTY: 1407 db_printf("TTY "); 1408 break; 1409 case PI_NET: 1410 db_printf("NET "); 1411 break; 1412 case PI_DISK: 1413 db_printf("DISK"); 1414 break; 1415 case PI_DULL: 1416 db_printf("DULL"); 1417 break; 1418 default: 1419 if (ih->ih_pri >= PI_SOFT) 1420 db_printf("SWI "); 1421 else 1422 db_printf("%4u", ih->ih_pri); 1423 break; 1424 } 1425 db_printf(" "); 1426 if (ih->ih_filter != NULL) { 1427 db_printf("[F]"); 1428 db_printsym((uintptr_t)ih->ih_filter, DB_STGY_PROC); 1429 } 1430 if (ih->ih_handler != NULL) { 1431 if (ih->ih_filter != NULL) 1432 db_printf(","); 1433 db_printf("[H]"); 1434 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC); 1435 } 1436 db_printf("(%p)", ih->ih_argument); 1437 if (ih->ih_need || 1438 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD | 1439 IH_MPSAFE)) != 0) { 1440 db_printf(" {"); 1441 comma = 0; 1442 if (ih->ih_flags & IH_EXCLUSIVE) { 1443 if (comma) 1444 db_printf(", "); 1445 db_printf("EXCL"); 1446 comma = 1; 1447 } 1448 if (ih->ih_flags & IH_ENTROPY) { 1449 if (comma) 1450 db_printf(", "); 1451 db_printf("ENTROPY"); 1452 comma = 1; 1453 } 1454 if (ih->ih_flags & IH_DEAD) { 1455 if (comma) 1456 db_printf(", "); 1457 db_printf("DEAD"); 1458 comma = 1; 1459 } 1460 if (ih->ih_flags & IH_MPSAFE) { 1461 if (comma) 1462 db_printf(", "); 1463 db_printf("MPSAFE"); 1464 comma = 1; 1465 } 1466 if (ih->ih_need) { 1467 if (comma) 1468 db_printf(", "); 1469 db_printf("NEED"); 1470 } 1471 db_printf("}"); 1472 } 1473 db_printf("\n"); 1474 } 1475 1476 /* 1477 * Dump details about a event. 1478 */ 1479 void 1480 db_dump_intr_event(struct intr_event *ie, int handlers) 1481 { 1482 struct intr_handler *ih; 1483 struct intr_thread *it; 1484 int comma; 1485 1486 db_printf("%s ", ie->ie_fullname); 1487 it = ie->ie_thread; 1488 if (it != NULL) 1489 db_printf("(pid %d)", it->it_thread->td_proc->p_pid); 1490 else 1491 db_printf("(no thread)"); 1492 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 || 1493 (it != NULL && it->it_need)) { 1494 db_printf(" {"); 1495 comma = 0; 1496 if (ie->ie_flags & IE_SOFT) { 1497 db_printf("SOFT"); 1498 comma = 1; 1499 } 1500 if (ie->ie_flags & IE_ENTROPY) { 1501 if (comma) 1502 db_printf(", "); 1503 db_printf("ENTROPY"); 1504 comma = 1; 1505 } 1506 if (ie->ie_flags & IE_ADDING_THREAD) { 1507 if (comma) 1508 db_printf(", "); 1509 db_printf("ADDING_THREAD"); 1510 comma = 1; 1511 } 1512 if (it != NULL && it->it_need) { 1513 if (comma) 1514 db_printf(", "); 1515 db_printf("NEED"); 1516 } 1517 db_printf("}"); 1518 } 1519 db_printf("\n"); 1520 1521 if (handlers) 1522 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) 1523 db_dump_intrhand(ih); 1524 } 1525 1526 /* 1527 * Dump data about interrupt handlers 1528 */ 1529 DB_SHOW_COMMAND(intr, db_show_intr) 1530 { 1531 struct intr_event *ie; 1532 int all, verbose; 1533 1534 verbose = strchr(modif, 'v') != NULL; 1535 all = strchr(modif, 'a') != NULL; 1536 TAILQ_FOREACH(ie, &event_list, ie_list) { 1537 if (!all && CK_SLIST_EMPTY(&ie->ie_handlers)) 1538 continue; 1539 db_dump_intr_event(ie, verbose); 1540 if (db_pager_quit) 1541 break; 1542 } 1543 } 1544 #endif /* DDB */ 1545 1546 /* 1547 * Start standard software interrupt threads 1548 */ 1549 static void 1550 start_softintr(void *dummy) 1551 { 1552 1553 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih)) 1554 panic("died while creating vm swi ithread"); 1555 } 1556 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, 1557 NULL); 1558 1559 /* 1560 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. 1561 * The data for this machine dependent, and the declarations are in machine 1562 * dependent code. The layout of intrnames and intrcnt however is machine 1563 * independent. 1564 * 1565 * We do not know the length of intrcnt and intrnames at compile time, so 1566 * calculate things at run time. 1567 */ 1568 static int 1569 sysctl_intrnames(SYSCTL_HANDLER_ARGS) 1570 { 1571 return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req)); 1572 } 1573 1574 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD, 1575 NULL, 0, sysctl_intrnames, "", "Interrupt Names"); 1576 1577 static int 1578 sysctl_intrcnt(SYSCTL_HANDLER_ARGS) 1579 { 1580 #ifdef SCTL_MASK32 1581 uint32_t *intrcnt32; 1582 unsigned i; 1583 int error; 1584 1585 if (req->flags & SCTL_MASK32) { 1586 if (!req->oldptr) 1587 return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req)); 1588 intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT); 1589 if (intrcnt32 == NULL) 1590 return (ENOMEM); 1591 for (i = 0; i < sintrcnt / sizeof (u_long); i++) 1592 intrcnt32[i] = intrcnt[i]; 1593 error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req); 1594 free(intrcnt32, M_TEMP); 1595 return (error); 1596 } 1597 #endif 1598 return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req)); 1599 } 1600 1601 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD, 1602 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts"); 1603 1604 #ifdef DDB 1605 /* 1606 * DDB command to dump the interrupt statistics. 1607 */ 1608 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt) 1609 { 1610 u_long *i; 1611 char *cp; 1612 u_int j; 1613 1614 cp = intrnames; 1615 j = 0; 1616 for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit; 1617 i++, j++) { 1618 if (*cp == '\0') 1619 break; 1620 if (*i != 0) 1621 db_printf("%s\t%lu\n", cp, *i); 1622 cp += strlen(cp) + 1; 1623 } 1624 } 1625 #endif
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