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/epoch.h> 52 #include <sys/random.h> 53 #include <sys/resourcevar.h> 54 #include <sys/sched.h> 55 #include <sys/smp.h> 56 #include <sys/sysctl.h> 57 #include <sys/syslog.h> 58 #include <sys/unistd.h> 59 #include <sys/vmmeter.h> 60 #include <machine/atomic.h> 61 #include <machine/cpu.h> 62 #include <machine/md_var.h> 63 #include <machine/smp.h> 64 #include <machine/stdarg.h> 65 #ifdef DDB 66 #include <ddb/ddb.h> 67 #include <ddb/db_sym.h> 68 #endif 69 70 /* 71 * Describe an interrupt thread. There is one of these per interrupt event. 72 */ 73 struct intr_thread { 74 struct intr_event *it_event; 75 struct thread *it_thread; /* Kernel thread. */ 76 int it_flags; /* (j) IT_* flags. */ 77 int it_need; /* Needs service. */ 78 }; 79 80 /* Interrupt thread flags kept in it_flags */ 81 #define IT_DEAD 0x000001 /* Thread is waiting to exit. */ 82 #define IT_WAIT 0x000002 /* Thread is waiting for completion. */ 83 84 struct intr_entropy { 85 struct thread *td; 86 uintptr_t event; 87 }; 88 89 struct intr_event *clk_intr_event; 90 struct intr_event *tty_intr_event; 91 void *vm_ih; 92 struct proc *intrproc; 93 94 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads"); 95 96 static int intr_storm_threshold = 0; 97 SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RWTUN, 98 &intr_storm_threshold, 0, 99 "Number of consecutive interrupts before storm protection is enabled"); 100 static int intr_epoch_batch = 1000; 101 SYSCTL_INT(_hw, OID_AUTO, intr_epoch_batch, CTLFLAG_RWTUN, &intr_epoch_batch, 102 0, "Maximum interrupt handler executions without re-entering epoch(9)"); 103 static TAILQ_HEAD(, intr_event) event_list = 104 TAILQ_HEAD_INITIALIZER(event_list); 105 static struct mtx event_lock; 106 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF); 107 108 static void intr_event_update(struct intr_event *ie); 109 static int intr_event_schedule_thread(struct intr_event *ie); 110 static struct intr_thread *ithread_create(const char *name); 111 static void ithread_destroy(struct intr_thread *ithread); 112 static void ithread_execute_handlers(struct proc *p, 113 struct intr_event *ie); 114 static void ithread_loop(void *); 115 static void ithread_update(struct intr_thread *ithd); 116 static void start_softintr(void *); 117 118 /* Map an interrupt type to an ithread priority. */ 119 u_char 120 intr_priority(enum intr_type flags) 121 { 122 u_char pri; 123 124 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET | 125 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV); 126 switch (flags) { 127 case INTR_TYPE_TTY: 128 pri = PI_TTY; 129 break; 130 case INTR_TYPE_BIO: 131 pri = PI_DISK; 132 break; 133 case INTR_TYPE_NET: 134 pri = PI_NET; 135 break; 136 case INTR_TYPE_CAM: 137 pri = PI_DISK; 138 break; 139 case INTR_TYPE_AV: 140 pri = PI_AV; 141 break; 142 case INTR_TYPE_CLK: 143 pri = PI_REALTIME; 144 break; 145 case INTR_TYPE_MISC: 146 pri = PI_DULL; /* don't care */ 147 break; 148 default: 149 /* We didn't specify an interrupt level. */ 150 panic("intr_priority: no interrupt type in flags"); 151 } 152 153 return pri; 154 } 155 156 /* 157 * Update an ithread based on the associated intr_event. 158 */ 159 static void 160 ithread_update(struct intr_thread *ithd) 161 { 162 struct intr_event *ie; 163 struct thread *td; 164 u_char pri; 165 166 ie = ithd->it_event; 167 td = ithd->it_thread; 168 mtx_assert(&ie->ie_lock, MA_OWNED); 169 170 /* Determine the overall priority of this event. */ 171 if (CK_SLIST_EMPTY(&ie->ie_handlers)) 172 pri = PRI_MAX_ITHD; 173 else 174 pri = CK_SLIST_FIRST(&ie->ie_handlers)->ih_pri; 175 176 /* Update name and priority. */ 177 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name)); 178 #ifdef KTR 179 sched_clear_tdname(td); 180 #endif 181 thread_lock(td); 182 sched_prio(td, pri); 183 thread_unlock(td); 184 } 185 186 /* 187 * Regenerate the full name of an interrupt event and update its priority. 188 */ 189 static void 190 intr_event_update(struct intr_event *ie) 191 { 192 struct intr_handler *ih; 193 char *last; 194 int missed, space, flags; 195 196 /* Start off with no entropy and just the name of the event. */ 197 mtx_assert(&ie->ie_lock, MA_OWNED); 198 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 199 flags = 0; 200 missed = 0; 201 space = 1; 202 203 /* Run through all the handlers updating values. */ 204 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 205 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 < 206 sizeof(ie->ie_fullname)) { 207 strcat(ie->ie_fullname, " "); 208 strcat(ie->ie_fullname, ih->ih_name); 209 space = 0; 210 } else 211 missed++; 212 flags |= ih->ih_flags; 213 } 214 ie->ie_hflags = flags; 215 216 /* 217 * If there is only one handler and its name is too long, just copy in 218 * as much of the end of the name (includes the unit number) as will 219 * fit. Otherwise, we have multiple handlers and not all of the names 220 * will fit. Add +'s to indicate missing names. If we run out of room 221 * and still have +'s to add, change the last character from a + to a *. 222 */ 223 if (missed == 1 && space == 1) { 224 ih = CK_SLIST_FIRST(&ie->ie_handlers); 225 missed = strlen(ie->ie_fullname) + strlen(ih->ih_name) + 2 - 226 sizeof(ie->ie_fullname); 227 strcat(ie->ie_fullname, (missed == 0) ? " " : "-"); 228 strcat(ie->ie_fullname, &ih->ih_name[missed]); 229 missed = 0; 230 } 231 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2]; 232 while (missed-- > 0) { 233 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) { 234 if (*last == '+') { 235 *last = '*'; 236 break; 237 } else 238 *last = '+'; 239 } else if (space) { 240 strcat(ie->ie_fullname, " +"); 241 space = 0; 242 } else 243 strcat(ie->ie_fullname, "+"); 244 } 245 246 /* 247 * If this event has an ithread, update it's priority and 248 * name. 249 */ 250 if (ie->ie_thread != NULL) 251 ithread_update(ie->ie_thread); 252 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname); 253 } 254 255 int 256 intr_event_create(struct intr_event **event, void *source, int flags, int irq, 257 void (*pre_ithread)(void *), void (*post_ithread)(void *), 258 void (*post_filter)(void *), int (*assign_cpu)(void *, int), 259 const char *fmt, ...) 260 { 261 struct intr_event *ie; 262 va_list ap; 263 264 /* The only valid flag during creation is IE_SOFT. */ 265 if ((flags & ~IE_SOFT) != 0) 266 return (EINVAL); 267 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO); 268 ie->ie_source = source; 269 ie->ie_pre_ithread = pre_ithread; 270 ie->ie_post_ithread = post_ithread; 271 ie->ie_post_filter = post_filter; 272 ie->ie_assign_cpu = assign_cpu; 273 ie->ie_flags = flags; 274 ie->ie_irq = irq; 275 ie->ie_cpu = NOCPU; 276 CK_SLIST_INIT(&ie->ie_handlers); 277 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF); 278 279 va_start(ap, fmt); 280 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap); 281 va_end(ap); 282 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 283 mtx_lock(&event_lock); 284 TAILQ_INSERT_TAIL(&event_list, ie, ie_list); 285 mtx_unlock(&event_lock); 286 if (event != NULL) 287 *event = ie; 288 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name); 289 return (0); 290 } 291 292 /* 293 * Bind an interrupt event to the specified CPU. Note that not all 294 * platforms support binding an interrupt to a CPU. For those 295 * platforms this request will fail. Using a cpu id of NOCPU unbinds 296 * the interrupt event. 297 */ 298 static int 299 _intr_event_bind(struct intr_event *ie, int cpu, bool bindirq, bool bindithread) 300 { 301 lwpid_t id; 302 int error; 303 304 /* Need a CPU to bind to. */ 305 if (cpu != NOCPU && CPU_ABSENT(cpu)) 306 return (EINVAL); 307 308 if (ie->ie_assign_cpu == NULL) 309 return (EOPNOTSUPP); 310 311 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR); 312 if (error) 313 return (error); 314 315 /* 316 * If we have any ithreads try to set their mask first to verify 317 * permissions, etc. 318 */ 319 if (bindithread) { 320 mtx_lock(&ie->ie_lock); 321 if (ie->ie_thread != NULL) { 322 id = ie->ie_thread->it_thread->td_tid; 323 mtx_unlock(&ie->ie_lock); 324 error = cpuset_setithread(id, cpu); 325 if (error) 326 return (error); 327 } else 328 mtx_unlock(&ie->ie_lock); 329 } 330 if (bindirq) 331 error = ie->ie_assign_cpu(ie->ie_source, cpu); 332 if (error) { 333 if (bindithread) { 334 mtx_lock(&ie->ie_lock); 335 if (ie->ie_thread != NULL) { 336 cpu = ie->ie_cpu; 337 id = ie->ie_thread->it_thread->td_tid; 338 mtx_unlock(&ie->ie_lock); 339 (void)cpuset_setithread(id, cpu); 340 } else 341 mtx_unlock(&ie->ie_lock); 342 } 343 return (error); 344 } 345 346 if (bindirq) { 347 mtx_lock(&ie->ie_lock); 348 ie->ie_cpu = cpu; 349 mtx_unlock(&ie->ie_lock); 350 } 351 352 return (error); 353 } 354 355 /* 356 * Bind an interrupt event to the specified CPU. For supported platforms, any 357 * associated ithreads as well as the primary interrupt context will be bound 358 * to the specificed CPU. 359 */ 360 int 361 intr_event_bind(struct intr_event *ie, int cpu) 362 { 363 364 return (_intr_event_bind(ie, cpu, true, true)); 365 } 366 367 /* 368 * Bind an interrupt event to the specified CPU, but do not bind associated 369 * ithreads. 370 */ 371 int 372 intr_event_bind_irqonly(struct intr_event *ie, int cpu) 373 { 374 375 return (_intr_event_bind(ie, cpu, true, false)); 376 } 377 378 /* 379 * Bind an interrupt event's ithread to the specified CPU. 380 */ 381 int 382 intr_event_bind_ithread(struct intr_event *ie, int cpu) 383 { 384 385 return (_intr_event_bind(ie, cpu, false, true)); 386 } 387 388 /* 389 * Bind an interrupt event's ithread to the specified cpuset. 390 */ 391 int 392 intr_event_bind_ithread_cpuset(struct intr_event *ie, cpuset_t *cs) 393 { 394 lwpid_t id; 395 396 mtx_lock(&ie->ie_lock); 397 if (ie->ie_thread != NULL) { 398 id = ie->ie_thread->it_thread->td_tid; 399 mtx_unlock(&ie->ie_lock); 400 return (cpuset_setthread(id, cs)); 401 } else { 402 mtx_unlock(&ie->ie_lock); 403 } 404 return (ENODEV); 405 } 406 407 static struct intr_event * 408 intr_lookup(int irq) 409 { 410 struct intr_event *ie; 411 412 mtx_lock(&event_lock); 413 TAILQ_FOREACH(ie, &event_list, ie_list) 414 if (ie->ie_irq == irq && 415 (ie->ie_flags & IE_SOFT) == 0 && 416 CK_SLIST_FIRST(&ie->ie_handlers) != NULL) 417 break; 418 mtx_unlock(&event_lock); 419 return (ie); 420 } 421 422 int 423 intr_setaffinity(int irq, int mode, void *m) 424 { 425 struct intr_event *ie; 426 cpuset_t *mask; 427 int cpu, n; 428 429 mask = m; 430 cpu = NOCPU; 431 /* 432 * If we're setting all cpus we can unbind. Otherwise make sure 433 * only one cpu is in the set. 434 */ 435 if (CPU_CMP(cpuset_root, mask)) { 436 for (n = 0; n < CPU_SETSIZE; n++) { 437 if (!CPU_ISSET(n, mask)) 438 continue; 439 if (cpu != NOCPU) 440 return (EINVAL); 441 cpu = n; 442 } 443 } 444 ie = intr_lookup(irq); 445 if (ie == NULL) 446 return (ESRCH); 447 switch (mode) { 448 case CPU_WHICH_IRQ: 449 return (intr_event_bind(ie, cpu)); 450 case CPU_WHICH_INTRHANDLER: 451 return (intr_event_bind_irqonly(ie, cpu)); 452 case CPU_WHICH_ITHREAD: 453 return (intr_event_bind_ithread(ie, cpu)); 454 default: 455 return (EINVAL); 456 } 457 } 458 459 int 460 intr_getaffinity(int irq, int mode, void *m) 461 { 462 struct intr_event *ie; 463 struct thread *td; 464 struct proc *p; 465 cpuset_t *mask; 466 lwpid_t id; 467 int error; 468 469 mask = m; 470 ie = intr_lookup(irq); 471 if (ie == NULL) 472 return (ESRCH); 473 474 error = 0; 475 CPU_ZERO(mask); 476 switch (mode) { 477 case CPU_WHICH_IRQ: 478 case CPU_WHICH_INTRHANDLER: 479 mtx_lock(&ie->ie_lock); 480 if (ie->ie_cpu == NOCPU) 481 CPU_COPY(cpuset_root, mask); 482 else 483 CPU_SET(ie->ie_cpu, mask); 484 mtx_unlock(&ie->ie_lock); 485 break; 486 case CPU_WHICH_ITHREAD: 487 mtx_lock(&ie->ie_lock); 488 if (ie->ie_thread == NULL) { 489 mtx_unlock(&ie->ie_lock); 490 CPU_COPY(cpuset_root, mask); 491 } else { 492 id = ie->ie_thread->it_thread->td_tid; 493 mtx_unlock(&ie->ie_lock); 494 error = cpuset_which(CPU_WHICH_TID, id, &p, &td, NULL); 495 if (error != 0) 496 return (error); 497 CPU_COPY(&td->td_cpuset->cs_mask, mask); 498 PROC_UNLOCK(p); 499 } 500 default: 501 return (EINVAL); 502 } 503 return (0); 504 } 505 506 int 507 intr_event_destroy(struct intr_event *ie) 508 { 509 510 mtx_lock(&event_lock); 511 mtx_lock(&ie->ie_lock); 512 if (!CK_SLIST_EMPTY(&ie->ie_handlers)) { 513 mtx_unlock(&ie->ie_lock); 514 mtx_unlock(&event_lock); 515 return (EBUSY); 516 } 517 TAILQ_REMOVE(&event_list, ie, ie_list); 518 #ifndef notyet 519 if (ie->ie_thread != NULL) { 520 ithread_destroy(ie->ie_thread); 521 ie->ie_thread = NULL; 522 } 523 #endif 524 mtx_unlock(&ie->ie_lock); 525 mtx_unlock(&event_lock); 526 mtx_destroy(&ie->ie_lock); 527 free(ie, M_ITHREAD); 528 return (0); 529 } 530 531 static struct intr_thread * 532 ithread_create(const char *name) 533 { 534 struct intr_thread *ithd; 535 struct thread *td; 536 int error; 537 538 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 539 540 error = kproc_kthread_add(ithread_loop, ithd, &intrproc, 541 &td, RFSTOPPED | RFHIGHPID, 542 0, "intr", "%s", name); 543 if (error) 544 panic("kproc_create() failed with %d", error); 545 thread_lock(td); 546 sched_class(td, PRI_ITHD); 547 TD_SET_IWAIT(td); 548 thread_unlock(td); 549 td->td_pflags |= TDP_ITHREAD; 550 ithd->it_thread = td; 551 CTR2(KTR_INTR, "%s: created %s", __func__, name); 552 return (ithd); 553 } 554 555 static void 556 ithread_destroy(struct intr_thread *ithread) 557 { 558 struct thread *td; 559 560 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name); 561 td = ithread->it_thread; 562 thread_lock(td); 563 ithread->it_flags |= IT_DEAD; 564 if (TD_AWAITING_INTR(td)) { 565 TD_CLR_IWAIT(td); 566 sched_add(td, SRQ_INTR); 567 } else 568 thread_unlock(td); 569 } 570 571 int 572 intr_event_add_handler(struct intr_event *ie, const char *name, 573 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 574 enum intr_type flags, void **cookiep) 575 { 576 struct intr_handler *ih, *temp_ih; 577 struct intr_handler **prevptr; 578 struct intr_thread *it; 579 580 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 581 return (EINVAL); 582 583 /* Allocate and populate an interrupt handler structure. */ 584 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 585 ih->ih_filter = filter; 586 ih->ih_handler = handler; 587 ih->ih_argument = arg; 588 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 589 ih->ih_event = ie; 590 ih->ih_pri = pri; 591 if (flags & INTR_EXCL) 592 ih->ih_flags = IH_EXCLUSIVE; 593 if (flags & INTR_MPSAFE) 594 ih->ih_flags |= IH_MPSAFE; 595 if (flags & INTR_ENTROPY) 596 ih->ih_flags |= IH_ENTROPY; 597 if (flags & INTR_TYPE_NET) 598 ih->ih_flags |= IH_NET; 599 600 /* We can only have one exclusive handler in a event. */ 601 mtx_lock(&ie->ie_lock); 602 if (!CK_SLIST_EMPTY(&ie->ie_handlers)) { 603 if ((flags & INTR_EXCL) || 604 (CK_SLIST_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 605 mtx_unlock(&ie->ie_lock); 606 free(ih, M_ITHREAD); 607 return (EINVAL); 608 } 609 } 610 611 /* Create a thread if we need one. */ 612 while (ie->ie_thread == NULL && handler != NULL) { 613 if (ie->ie_flags & IE_ADDING_THREAD) 614 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 615 else { 616 ie->ie_flags |= IE_ADDING_THREAD; 617 mtx_unlock(&ie->ie_lock); 618 it = ithread_create("intr: newborn"); 619 mtx_lock(&ie->ie_lock); 620 ie->ie_flags &= ~IE_ADDING_THREAD; 621 ie->ie_thread = it; 622 it->it_event = ie; 623 ithread_update(it); 624 wakeup(ie); 625 } 626 } 627 628 /* Add the new handler to the event in priority order. */ 629 CK_SLIST_FOREACH_PREVPTR(temp_ih, prevptr, &ie->ie_handlers, ih_next) { 630 if (temp_ih->ih_pri > ih->ih_pri) 631 break; 632 } 633 CK_SLIST_INSERT_PREVPTR(prevptr, temp_ih, ih, ih_next); 634 635 intr_event_update(ie); 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 } 645 646 /* 647 * Append a description preceded by a ':' to the name of the specified 648 * interrupt handler. 649 */ 650 int 651 intr_event_describe_handler(struct intr_event *ie, void *cookie, 652 const char *descr) 653 { 654 struct intr_handler *ih; 655 size_t space; 656 char *start; 657 658 mtx_lock(&ie->ie_lock); 659 #ifdef INVARIANTS 660 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 661 if (ih == cookie) 662 break; 663 } 664 if (ih == NULL) { 665 mtx_unlock(&ie->ie_lock); 666 panic("handler %p not found in interrupt event %p", cookie, ie); 667 } 668 #endif 669 ih = cookie; 670 671 /* 672 * Look for an existing description by checking for an 673 * existing ":". This assumes device names do not include 674 * colons. If one is found, prepare to insert the new 675 * description at that point. If one is not found, find the 676 * end of the name to use as the insertion point. 677 */ 678 start = strchr(ih->ih_name, ':'); 679 if (start == NULL) 680 start = strchr(ih->ih_name, 0); 681 682 /* 683 * See if there is enough remaining room in the string for the 684 * description + ":". The "- 1" leaves room for the trailing 685 * '\0'. The "+ 1" accounts for the colon. 686 */ 687 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1; 688 if (strlen(descr) + 1 > space) { 689 mtx_unlock(&ie->ie_lock); 690 return (ENOSPC); 691 } 692 693 /* Append a colon followed by the description. */ 694 *start = ':'; 695 strcpy(start + 1, descr); 696 intr_event_update(ie); 697 mtx_unlock(&ie->ie_lock); 698 return (0); 699 } 700 701 /* 702 * Return the ie_source field from the intr_event an intr_handler is 703 * associated with. 704 */ 705 void * 706 intr_handler_source(void *cookie) 707 { 708 struct intr_handler *ih; 709 struct intr_event *ie; 710 711 ih = (struct intr_handler *)cookie; 712 if (ih == NULL) 713 return (NULL); 714 ie = ih->ih_event; 715 KASSERT(ie != NULL, 716 ("interrupt handler \"%s\" has a NULL interrupt event", 717 ih->ih_name)); 718 return (ie->ie_source); 719 } 720 721 /* 722 * If intr_event_handle() is running in the ISR context at the time of the call, 723 * then wait for it to complete. 724 */ 725 static void 726 intr_event_barrier(struct intr_event *ie) 727 { 728 int phase; 729 730 mtx_assert(&ie->ie_lock, MA_OWNED); 731 phase = ie->ie_phase; 732 733 /* 734 * Switch phase to direct future interrupts to the other active counter. 735 * Make sure that any preceding stores are visible before the switch. 736 */ 737 KASSERT(ie->ie_active[!phase] == 0, ("idle phase has activity")); 738 atomic_store_rel_int(&ie->ie_phase, !phase); 739 740 /* 741 * This code cooperates with wait-free iteration of ie_handlers 742 * in intr_event_handle. 743 * Make sure that the removal and the phase update are not reordered 744 * with the active count check. 745 * Note that no combination of acquire and release fences can provide 746 * that guarantee as Store->Load sequences can always be reordered. 747 */ 748 atomic_thread_fence_seq_cst(); 749 750 /* 751 * Now wait on the inactive phase. 752 * The acquire fence is needed so that that all post-barrier accesses 753 * are after the check. 754 */ 755 while (ie->ie_active[phase] > 0) 756 cpu_spinwait(); 757 atomic_thread_fence_acq(); 758 } 759 760 static void 761 intr_handler_barrier(struct intr_handler *handler) 762 { 763 struct intr_event *ie; 764 765 ie = handler->ih_event; 766 mtx_assert(&ie->ie_lock, MA_OWNED); 767 KASSERT((handler->ih_flags & IH_DEAD) == 0, 768 ("update for a removed handler")); 769 770 if (ie->ie_thread == NULL) { 771 intr_event_barrier(ie); 772 return; 773 } 774 if ((handler->ih_flags & IH_CHANGED) == 0) { 775 handler->ih_flags |= IH_CHANGED; 776 intr_event_schedule_thread(ie); 777 } 778 while ((handler->ih_flags & IH_CHANGED) != 0) 779 msleep(handler, &ie->ie_lock, 0, "ih_barr", 0); 780 } 781 782 /* 783 * Sleep until an ithread finishes executing an interrupt handler. 784 * 785 * XXX Doesn't currently handle interrupt filters or fast interrupt 786 * handlers. This is intended for compatibility with linux drivers 787 * only. Do not use in BSD code. 788 */ 789 void 790 _intr_drain(int irq) 791 { 792 struct intr_event *ie; 793 struct intr_thread *ithd; 794 struct thread *td; 795 796 ie = intr_lookup(irq); 797 if (ie == NULL) 798 return; 799 if (ie->ie_thread == NULL) 800 return; 801 ithd = ie->ie_thread; 802 td = ithd->it_thread; 803 /* 804 * We set the flag and wait for it to be cleared to avoid 805 * long delays with potentially busy interrupt handlers 806 * were we to only sample TD_AWAITING_INTR() every tick. 807 */ 808 thread_lock(td); 809 if (!TD_AWAITING_INTR(td)) { 810 ithd->it_flags |= IT_WAIT; 811 while (ithd->it_flags & IT_WAIT) { 812 thread_unlock(td); 813 pause("idrain", 1); 814 thread_lock(td); 815 } 816 } 817 thread_unlock(td); 818 return; 819 } 820 821 int 822 intr_event_remove_handler(void *cookie) 823 { 824 struct intr_handler *handler = (struct intr_handler *)cookie; 825 struct intr_event *ie; 826 struct intr_handler *ih; 827 struct intr_handler **prevptr; 828 #ifdef notyet 829 int dead; 830 #endif 831 832 if (handler == NULL) 833 return (EINVAL); 834 ie = handler->ih_event; 835 KASSERT(ie != NULL, 836 ("interrupt handler \"%s\" has a NULL interrupt event", 837 handler->ih_name)); 838 839 mtx_lock(&ie->ie_lock); 840 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 841 ie->ie_name); 842 CK_SLIST_FOREACH_PREVPTR(ih, prevptr, &ie->ie_handlers, ih_next) { 843 if (ih == handler) 844 break; 845 } 846 if (ih == NULL) { 847 panic("interrupt handler \"%s\" not found in " 848 "interrupt event \"%s\"", handler->ih_name, ie->ie_name); 849 } 850 851 /* 852 * If there is no ithread, then directly remove the handler. Note that 853 * intr_event_handle() iterates ie_handlers in a lock-less fashion, so 854 * care needs to be taken to keep ie_handlers consistent and to free 855 * the removed handler only when ie_handlers is quiescent. 856 */ 857 if (ie->ie_thread == NULL) { 858 CK_SLIST_REMOVE_PREVPTR(prevptr, ih, ih_next); 859 intr_event_barrier(ie); 860 intr_event_update(ie); 861 mtx_unlock(&ie->ie_lock); 862 free(handler, M_ITHREAD); 863 return (0); 864 } 865 866 /* 867 * Let the interrupt thread do the job. 868 * The interrupt source is disabled when the interrupt thread is 869 * running, so it does not have to worry about interaction with 870 * intr_event_handle(). 871 */ 872 KASSERT((handler->ih_flags & IH_DEAD) == 0, 873 ("duplicate handle remove")); 874 handler->ih_flags |= IH_DEAD; 875 intr_event_schedule_thread(ie); 876 while (handler->ih_flags & IH_DEAD) 877 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 878 intr_event_update(ie); 879 880 #ifdef notyet 881 /* 882 * XXX: This could be bad in the case of ppbus(8). Also, I think 883 * this could lead to races of stale data when servicing an 884 * interrupt. 885 */ 886 dead = 1; 887 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 888 if (ih->ih_handler != NULL) { 889 dead = 0; 890 break; 891 } 892 } 893 if (dead) { 894 ithread_destroy(ie->ie_thread); 895 ie->ie_thread = NULL; 896 } 897 #endif 898 mtx_unlock(&ie->ie_lock); 899 free(handler, M_ITHREAD); 900 return (0); 901 } 902 903 int 904 intr_event_suspend_handler(void *cookie) 905 { 906 struct intr_handler *handler = (struct intr_handler *)cookie; 907 struct intr_event *ie; 908 909 if (handler == NULL) 910 return (EINVAL); 911 ie = handler->ih_event; 912 KASSERT(ie != NULL, 913 ("interrupt handler \"%s\" has a NULL interrupt event", 914 handler->ih_name)); 915 mtx_lock(&ie->ie_lock); 916 handler->ih_flags |= IH_SUSP; 917 intr_handler_barrier(handler); 918 mtx_unlock(&ie->ie_lock); 919 return (0); 920 } 921 922 int 923 intr_event_resume_handler(void *cookie) 924 { 925 struct intr_handler *handler = (struct intr_handler *)cookie; 926 struct intr_event *ie; 927 928 if (handler == NULL) 929 return (EINVAL); 930 ie = handler->ih_event; 931 KASSERT(ie != NULL, 932 ("interrupt handler \"%s\" has a NULL interrupt event", 933 handler->ih_name)); 934 935 /* 936 * intr_handler_barrier() acts not only as a barrier, 937 * it also allows to check for any pending interrupts. 938 */ 939 mtx_lock(&ie->ie_lock); 940 handler->ih_flags &= ~IH_SUSP; 941 intr_handler_barrier(handler); 942 mtx_unlock(&ie->ie_lock); 943 return (0); 944 } 945 946 static int 947 intr_event_schedule_thread(struct intr_event *ie) 948 { 949 struct intr_entropy entropy; 950 struct intr_thread *it; 951 struct thread *td; 952 struct thread *ctd; 953 954 /* 955 * If no ithread or no handlers, then we have a stray interrupt. 956 */ 957 if (ie == NULL || CK_SLIST_EMPTY(&ie->ie_handlers) || 958 ie->ie_thread == NULL) 959 return (EINVAL); 960 961 ctd = curthread; 962 it = ie->ie_thread; 963 td = it->it_thread; 964 965 /* 966 * If any of the handlers for this ithread claim to be good 967 * sources of entropy, then gather some. 968 */ 969 if (ie->ie_hflags & IH_ENTROPY) { 970 entropy.event = (uintptr_t)ie; 971 entropy.td = ctd; 972 random_harvest_queue(&entropy, sizeof(entropy), RANDOM_INTERRUPT); 973 } 974 975 KASSERT(td->td_proc != NULL, ("ithread %s has no process", ie->ie_name)); 976 977 /* 978 * Set it_need to tell the thread to keep running if it is already 979 * running. Then, lock the thread and see if we actually need to 980 * put it on the runqueue. 981 * 982 * Use store_rel to arrange that the store to ih_need in 983 * swi_sched() is before the store to it_need and prepare for 984 * transfer of this order to loads in the ithread. 985 */ 986 atomic_store_rel_int(&it->it_need, 1); 987 thread_lock(td); 988 if (TD_AWAITING_INTR(td)) { 989 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, td->td_proc->p_pid, 990 td->td_name); 991 TD_CLR_IWAIT(td); 992 sched_add(td, SRQ_INTR); 993 } else { 994 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 995 __func__, td->td_proc->p_pid, td->td_name, it->it_need, td->td_state); 996 thread_unlock(td); 997 } 998 999 return (0); 1000 } 1001 1002 /* 1003 * Allow interrupt event binding for software interrupt handlers -- a no-op, 1004 * since interrupts are generated in software rather than being directed by 1005 * a PIC. 1006 */ 1007 static int 1008 swi_assign_cpu(void *arg, int cpu) 1009 { 1010 1011 return (0); 1012 } 1013 1014 /* 1015 * Add a software interrupt handler to a specified event. If a given event 1016 * is not specified, then a new event is created. 1017 */ 1018 int 1019 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler, 1020 void *arg, int pri, enum intr_type flags, void **cookiep) 1021 { 1022 struct intr_event *ie; 1023 int error = 0; 1024 1025 if (flags & INTR_ENTROPY) 1026 return (EINVAL); 1027 1028 ie = (eventp != NULL) ? *eventp : NULL; 1029 1030 if (ie != NULL) { 1031 if (!(ie->ie_flags & IE_SOFT)) 1032 return (EINVAL); 1033 } else { 1034 error = intr_event_create(&ie, NULL, IE_SOFT, 0, 1035 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri); 1036 if (error) 1037 return (error); 1038 if (eventp != NULL) 1039 *eventp = ie; 1040 } 1041 if (handler != NULL) { 1042 error = intr_event_add_handler(ie, name, NULL, handler, arg, 1043 PI_SWI(pri), flags, cookiep); 1044 } 1045 return (error); 1046 } 1047 1048 /* 1049 * Schedule a software interrupt thread. 1050 */ 1051 void 1052 swi_sched(void *cookie, int flags) 1053 { 1054 struct intr_handler *ih = (struct intr_handler *)cookie; 1055 struct intr_event *ie = ih->ih_event; 1056 struct intr_entropy entropy; 1057 int error __unused; 1058 1059 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name, 1060 ih->ih_need); 1061 1062 if ((flags & SWI_FROMNMI) == 0) { 1063 entropy.event = (uintptr_t)ih; 1064 entropy.td = curthread; 1065 random_harvest_queue(&entropy, sizeof(entropy), RANDOM_SWI); 1066 } 1067 1068 /* 1069 * Set ih_need for this handler so that if the ithread is already 1070 * running it will execute this handler on the next pass. Otherwise, 1071 * it will execute it the next time it runs. 1072 */ 1073 ih->ih_need = 1; 1074 1075 if (flags & SWI_DELAY) 1076 return; 1077 1078 if (flags & SWI_FROMNMI) { 1079 #if defined(SMP) && (defined(__i386__) || defined(__amd64__)) 1080 KASSERT(ie == clk_intr_event, 1081 ("SWI_FROMNMI used not with clk_intr_event")); 1082 ipi_self_from_nmi(IPI_SWI); 1083 #endif 1084 } else { 1085 VM_CNT_INC(v_soft); 1086 error = intr_event_schedule_thread(ie); 1087 KASSERT(error == 0, ("stray software interrupt")); 1088 } 1089 } 1090 1091 /* 1092 * Remove a software interrupt handler. Currently this code does not 1093 * remove the associated interrupt event if it becomes empty. Calling code 1094 * may do so manually via intr_event_destroy(), but that's not really 1095 * an optimal interface. 1096 */ 1097 int 1098 swi_remove(void *cookie) 1099 { 1100 1101 return (intr_event_remove_handler(cookie)); 1102 } 1103 1104 static void 1105 intr_event_execute_handlers(struct proc *p, struct intr_event *ie) 1106 { 1107 struct intr_handler *ih, *ihn, *ihp; 1108 1109 ihp = NULL; 1110 CK_SLIST_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) { 1111 /* 1112 * If this handler is marked for death, remove it from 1113 * the list of handlers and wake up the sleeper. 1114 */ 1115 if (ih->ih_flags & IH_DEAD) { 1116 mtx_lock(&ie->ie_lock); 1117 if (ihp == NULL) 1118 CK_SLIST_REMOVE_HEAD(&ie->ie_handlers, ih_next); 1119 else 1120 CK_SLIST_REMOVE_AFTER(ihp, ih_next); 1121 ih->ih_flags &= ~IH_DEAD; 1122 wakeup(ih); 1123 mtx_unlock(&ie->ie_lock); 1124 continue; 1125 } 1126 1127 /* 1128 * Now that we know that the current element won't be removed 1129 * update the previous element. 1130 */ 1131 ihp = ih; 1132 1133 if ((ih->ih_flags & IH_CHANGED) != 0) { 1134 mtx_lock(&ie->ie_lock); 1135 ih->ih_flags &= ~IH_CHANGED; 1136 wakeup(ih); 1137 mtx_unlock(&ie->ie_lock); 1138 } 1139 1140 /* Skip filter only handlers */ 1141 if (ih->ih_handler == NULL) 1142 continue; 1143 1144 /* Skip suspended handlers */ 1145 if ((ih->ih_flags & IH_SUSP) != 0) 1146 continue; 1147 1148 /* 1149 * For software interrupt threads, we only execute 1150 * handlers that have their need flag set. Hardware 1151 * interrupt threads always invoke all of their handlers. 1152 * 1153 * ih_need can only be 0 or 1. Failed cmpset below 1154 * means that there is no request to execute handlers, 1155 * so a retry of the cmpset is not needed. 1156 */ 1157 if ((ie->ie_flags & IE_SOFT) != 0 && 1158 atomic_cmpset_int(&ih->ih_need, 1, 0) == 0) 1159 continue; 1160 1161 /* Execute this handler. */ 1162 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1163 __func__, p->p_pid, (void *)ih->ih_handler, 1164 ih->ih_argument, ih->ih_name, ih->ih_flags); 1165 1166 if (!(ih->ih_flags & IH_MPSAFE)) 1167 mtx_lock(&Giant); 1168 ih->ih_handler(ih->ih_argument); 1169 if (!(ih->ih_flags & IH_MPSAFE)) 1170 mtx_unlock(&Giant); 1171 } 1172 } 1173 1174 static void 1175 ithread_execute_handlers(struct proc *p, struct intr_event *ie) 1176 { 1177 1178 /* Interrupt handlers should not sleep. */ 1179 if (!(ie->ie_flags & IE_SOFT)) 1180 THREAD_NO_SLEEPING(); 1181 intr_event_execute_handlers(p, ie); 1182 if (!(ie->ie_flags & IE_SOFT)) 1183 THREAD_SLEEPING_OK(); 1184 1185 /* 1186 * Interrupt storm handling: 1187 * 1188 * If this interrupt source is currently storming, then throttle 1189 * it to only fire the handler once per clock tick. 1190 * 1191 * If this interrupt source is not currently storming, but the 1192 * number of back to back interrupts exceeds the storm threshold, 1193 * then enter storming mode. 1194 */ 1195 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold && 1196 !(ie->ie_flags & IE_SOFT)) { 1197 /* Report the message only once every second. */ 1198 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) { 1199 printf( 1200 "interrupt storm detected on \"%s\"; throttling interrupt source\n", 1201 ie->ie_name); 1202 } 1203 pause("istorm", 1); 1204 } else 1205 ie->ie_count++; 1206 1207 /* 1208 * Now that all the handlers have had a chance to run, reenable 1209 * the interrupt source. 1210 */ 1211 if (ie->ie_post_ithread != NULL) 1212 ie->ie_post_ithread(ie->ie_source); 1213 } 1214 1215 /* 1216 * This is the main code for interrupt threads. 1217 */ 1218 static void 1219 ithread_loop(void *arg) 1220 { 1221 struct epoch_tracker et; 1222 struct intr_thread *ithd; 1223 struct intr_event *ie; 1224 struct thread *td; 1225 struct proc *p; 1226 int wake, epoch_count; 1227 bool needs_epoch; 1228 1229 td = curthread; 1230 p = td->td_proc; 1231 ithd = (struct intr_thread *)arg; 1232 KASSERT(ithd->it_thread == td, 1233 ("%s: ithread and proc linkage out of sync", __func__)); 1234 ie = ithd->it_event; 1235 ie->ie_count = 0; 1236 wake = 0; 1237 1238 /* 1239 * As long as we have interrupts outstanding, go through the 1240 * list of handlers, giving each one a go at it. 1241 */ 1242 for (;;) { 1243 /* 1244 * If we are an orphaned thread, then just die. 1245 */ 1246 if (ithd->it_flags & IT_DEAD) { 1247 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1248 p->p_pid, td->td_name); 1249 free(ithd, M_ITHREAD); 1250 kthread_exit(); 1251 } 1252 1253 /* 1254 * Service interrupts. If another interrupt arrives while 1255 * we are running, it will set it_need to note that we 1256 * should make another pass. 1257 * 1258 * The load_acq part of the following cmpset ensures 1259 * that the load of ih_need in ithread_execute_handlers() 1260 * is ordered after the load of it_need here. 1261 */ 1262 needs_epoch = 1263 (atomic_load_int(&ie->ie_hflags) & IH_NET) != 0; 1264 if (needs_epoch) { 1265 epoch_count = 0; 1266 NET_EPOCH_ENTER(et); 1267 } 1268 while (atomic_cmpset_acq_int(&ithd->it_need, 1, 0) != 0) { 1269 ithread_execute_handlers(p, ie); 1270 if (needs_epoch && 1271 ++epoch_count >= intr_epoch_batch) { 1272 NET_EPOCH_EXIT(et); 1273 epoch_count = 0; 1274 NET_EPOCH_ENTER(et); 1275 } 1276 } 1277 if (needs_epoch) 1278 NET_EPOCH_EXIT(et); 1279 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1280 mtx_assert(&Giant, MA_NOTOWNED); 1281 1282 /* 1283 * Processed all our interrupts. Now get the sched 1284 * lock. This may take a while and it_need may get 1285 * set again, so we have to check it again. 1286 */ 1287 thread_lock(td); 1288 if (atomic_load_acq_int(&ithd->it_need) == 0 && 1289 (ithd->it_flags & (IT_DEAD | IT_WAIT)) == 0) { 1290 TD_SET_IWAIT(td); 1291 ie->ie_count = 0; 1292 mi_switch(SW_VOL | SWT_IWAIT); 1293 } else { 1294 if (ithd->it_flags & IT_WAIT) { 1295 wake = 1; 1296 ithd->it_flags &= ~IT_WAIT; 1297 } 1298 thread_unlock(td); 1299 } 1300 if (wake) { 1301 wakeup(ithd); 1302 wake = 0; 1303 } 1304 } 1305 } 1306 1307 /* 1308 * Main interrupt handling body. 1309 * 1310 * Input: 1311 * o ie: the event connected to this interrupt. 1312 * o frame: some archs (i.e. i386) pass a frame to some. 1313 * handlers as their main argument. 1314 * Return value: 1315 * o 0: everything ok. 1316 * o EINVAL: stray interrupt. 1317 */ 1318 int 1319 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1320 { 1321 struct intr_handler *ih; 1322 struct trapframe *oldframe; 1323 struct thread *td; 1324 int phase; 1325 int ret; 1326 bool filter, thread; 1327 1328 td = curthread; 1329 1330 #ifdef KSTACK_USAGE_PROF 1331 intr_prof_stack_use(td, frame); 1332 #endif 1333 1334 /* An interrupt with no event or handlers is a stray interrupt. */ 1335 if (ie == NULL || CK_SLIST_EMPTY(&ie->ie_handlers)) 1336 return (EINVAL); 1337 1338 /* 1339 * Execute fast interrupt handlers directly. 1340 * To support clock handlers, if a handler registers 1341 * with a NULL argument, then we pass it a pointer to 1342 * a trapframe as its argument. 1343 */ 1344 td->td_intr_nesting_level++; 1345 filter = false; 1346 thread = false; 1347 ret = 0; 1348 critical_enter(); 1349 oldframe = td->td_intr_frame; 1350 td->td_intr_frame = frame; 1351 1352 phase = ie->ie_phase; 1353 atomic_add_int(&ie->ie_active[phase], 1); 1354 1355 /* 1356 * This fence is required to ensure that no later loads are 1357 * re-ordered before the ie_active store. 1358 */ 1359 atomic_thread_fence_seq_cst(); 1360 1361 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 1362 if ((ih->ih_flags & IH_SUSP) != 0) 1363 continue; 1364 if ((ie->ie_flags & IE_SOFT) != 0 && ih->ih_need == 0) 1365 continue; 1366 if (ih->ih_filter == NULL) { 1367 thread = true; 1368 continue; 1369 } 1370 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__, 1371 ih->ih_filter, ih->ih_argument == NULL ? frame : 1372 ih->ih_argument, ih->ih_name); 1373 if (ih->ih_argument == NULL) 1374 ret = ih->ih_filter(frame); 1375 else 1376 ret = ih->ih_filter(ih->ih_argument); 1377 KASSERT(ret == FILTER_STRAY || 1378 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1379 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1380 ("%s: incorrect return value %#x from %s", __func__, ret, 1381 ih->ih_name)); 1382 filter = filter || ret == FILTER_HANDLED; 1383 1384 /* 1385 * Wrapper handler special handling: 1386 * 1387 * in some particular cases (like pccard and pccbb), 1388 * the _real_ device handler is wrapped in a couple of 1389 * functions - a filter wrapper and an ithread wrapper. 1390 * In this case (and just in this case), the filter wrapper 1391 * could ask the system to schedule the ithread and mask 1392 * the interrupt source if the wrapped handler is composed 1393 * of just an ithread handler. 1394 * 1395 * TODO: write a generic wrapper to avoid people rolling 1396 * their own. 1397 */ 1398 if (!thread) { 1399 if (ret == FILTER_SCHEDULE_THREAD) 1400 thread = true; 1401 } 1402 } 1403 atomic_add_rel_int(&ie->ie_active[phase], -1); 1404 1405 td->td_intr_frame = oldframe; 1406 1407 if (thread) { 1408 if (ie->ie_pre_ithread != NULL) 1409 ie->ie_pre_ithread(ie->ie_source); 1410 } else { 1411 if (ie->ie_post_filter != NULL) 1412 ie->ie_post_filter(ie->ie_source); 1413 } 1414 1415 /* Schedule the ithread if needed. */ 1416 if (thread) { 1417 int error __unused; 1418 1419 error = intr_event_schedule_thread(ie); 1420 KASSERT(error == 0, ("bad stray interrupt")); 1421 } 1422 critical_exit(); 1423 td->td_intr_nesting_level--; 1424 #ifdef notyet 1425 /* The interrupt is not aknowledged by any filter and has no ithread. */ 1426 if (!thread && !filter) 1427 return (EINVAL); 1428 #endif 1429 return (0); 1430 } 1431 1432 #ifdef DDB 1433 /* 1434 * Dump details about an interrupt handler 1435 */ 1436 static void 1437 db_dump_intrhand(struct intr_handler *ih) 1438 { 1439 int comma; 1440 1441 db_printf("\t%-10s ", ih->ih_name); 1442 switch (ih->ih_pri) { 1443 case PI_REALTIME: 1444 db_printf("CLK "); 1445 break; 1446 case PI_AV: 1447 db_printf("AV "); 1448 break; 1449 case PI_TTY: 1450 db_printf("TTY "); 1451 break; 1452 case PI_NET: 1453 db_printf("NET "); 1454 break; 1455 case PI_DISK: 1456 db_printf("DISK"); 1457 break; 1458 case PI_DULL: 1459 db_printf("DULL"); 1460 break; 1461 default: 1462 if (ih->ih_pri >= PI_SOFT) 1463 db_printf("SWI "); 1464 else 1465 db_printf("%4u", ih->ih_pri); 1466 break; 1467 } 1468 db_printf(" "); 1469 if (ih->ih_filter != NULL) { 1470 db_printf("[F]"); 1471 db_printsym((uintptr_t)ih->ih_filter, DB_STGY_PROC); 1472 } 1473 if (ih->ih_handler != NULL) { 1474 if (ih->ih_filter != NULL) 1475 db_printf(","); 1476 db_printf("[H]"); 1477 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC); 1478 } 1479 db_printf("(%p)", ih->ih_argument); 1480 if (ih->ih_need || 1481 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD | 1482 IH_MPSAFE)) != 0) { 1483 db_printf(" {"); 1484 comma = 0; 1485 if (ih->ih_flags & IH_EXCLUSIVE) { 1486 if (comma) 1487 db_printf(", "); 1488 db_printf("EXCL"); 1489 comma = 1; 1490 } 1491 if (ih->ih_flags & IH_ENTROPY) { 1492 if (comma) 1493 db_printf(", "); 1494 db_printf("ENTROPY"); 1495 comma = 1; 1496 } 1497 if (ih->ih_flags & IH_DEAD) { 1498 if (comma) 1499 db_printf(", "); 1500 db_printf("DEAD"); 1501 comma = 1; 1502 } 1503 if (ih->ih_flags & IH_MPSAFE) { 1504 if (comma) 1505 db_printf(", "); 1506 db_printf("MPSAFE"); 1507 comma = 1; 1508 } 1509 if (ih->ih_need) { 1510 if (comma) 1511 db_printf(", "); 1512 db_printf("NEED"); 1513 } 1514 db_printf("}"); 1515 } 1516 db_printf("\n"); 1517 } 1518 1519 /* 1520 * Dump details about a event. 1521 */ 1522 void 1523 db_dump_intr_event(struct intr_event *ie, int handlers) 1524 { 1525 struct intr_handler *ih; 1526 struct intr_thread *it; 1527 int comma; 1528 1529 db_printf("%s ", ie->ie_fullname); 1530 it = ie->ie_thread; 1531 if (it != NULL) 1532 db_printf("(pid %d)", it->it_thread->td_proc->p_pid); 1533 else 1534 db_printf("(no thread)"); 1535 if ((ie->ie_flags & (IE_SOFT | IE_ADDING_THREAD)) != 0 || 1536 (it != NULL && it->it_need)) { 1537 db_printf(" {"); 1538 comma = 0; 1539 if (ie->ie_flags & IE_SOFT) { 1540 db_printf("SOFT"); 1541 comma = 1; 1542 } 1543 if (ie->ie_flags & IE_ADDING_THREAD) { 1544 if (comma) 1545 db_printf(", "); 1546 db_printf("ADDING_THREAD"); 1547 comma = 1; 1548 } 1549 if (it != NULL && it->it_need) { 1550 if (comma) 1551 db_printf(", "); 1552 db_printf("NEED"); 1553 } 1554 db_printf("}"); 1555 } 1556 db_printf("\n"); 1557 1558 if (handlers) 1559 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) 1560 db_dump_intrhand(ih); 1561 } 1562 1563 /* 1564 * Dump data about interrupt handlers 1565 */ 1566 DB_SHOW_COMMAND(intr, db_show_intr) 1567 { 1568 struct intr_event *ie; 1569 int all, verbose; 1570 1571 verbose = strchr(modif, 'v') != NULL; 1572 all = strchr(modif, 'a') != NULL; 1573 TAILQ_FOREACH(ie, &event_list, ie_list) { 1574 if (!all && CK_SLIST_EMPTY(&ie->ie_handlers)) 1575 continue; 1576 db_dump_intr_event(ie, verbose); 1577 if (db_pager_quit) 1578 break; 1579 } 1580 } 1581 #endif /* DDB */ 1582 1583 /* 1584 * Start standard software interrupt threads 1585 */ 1586 static void 1587 start_softintr(void *dummy) 1588 { 1589 1590 if (swi_add(&clk_intr_event, "clk", NULL, NULL, SWI_CLOCK, 1591 INTR_MPSAFE, NULL)) 1592 panic("died while creating clk swi ithread"); 1593 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih)) 1594 panic("died while creating vm swi ithread"); 1595 } 1596 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, 1597 NULL); 1598 1599 /* 1600 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. 1601 * The data for this machine dependent, and the declarations are in machine 1602 * dependent code. The layout of intrnames and intrcnt however is machine 1603 * independent. 1604 * 1605 * We do not know the length of intrcnt and intrnames at compile time, so 1606 * calculate things at run time. 1607 */ 1608 static int 1609 sysctl_intrnames(SYSCTL_HANDLER_ARGS) 1610 { 1611 return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req)); 1612 } 1613 1614 SYSCTL_PROC(_hw, OID_AUTO, intrnames, 1615 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, NULL, 0, 1616 sysctl_intrnames, "", 1617 "Interrupt Names"); 1618 1619 static int 1620 sysctl_intrcnt(SYSCTL_HANDLER_ARGS) 1621 { 1622 #ifdef SCTL_MASK32 1623 uint32_t *intrcnt32; 1624 unsigned i; 1625 int error; 1626 1627 if (req->flags & SCTL_MASK32) { 1628 if (!req->oldptr) 1629 return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req)); 1630 intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT); 1631 if (intrcnt32 == NULL) 1632 return (ENOMEM); 1633 for (i = 0; i < sintrcnt / sizeof (u_long); i++) 1634 intrcnt32[i] = intrcnt[i]; 1635 error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req); 1636 free(intrcnt32, M_TEMP); 1637 return (error); 1638 } 1639 #endif 1640 return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req)); 1641 } 1642 1643 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, 1644 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT, NULL, 0, 1645 sysctl_intrcnt, "", 1646 "Interrupt Counts"); 1647 1648 #ifdef DDB 1649 /* 1650 * DDB command to dump the interrupt statistics. 1651 */ 1652 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt) 1653 { 1654 u_long *i; 1655 char *cp; 1656 u_int j; 1657 1658 cp = intrnames; 1659 j = 0; 1660 for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit; 1661 i++, j++) { 1662 if (*cp == '\0') 1663 break; 1664 if (*i != 0) 1665 db_printf("%s\t%lu\n", cp, *i); 1666 cp += strlen(cp) + 1; 1667 } 1668 } 1669 #endif
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