Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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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_hwpmc_hooks.h" 34 #include "opt_kstack_usage_prof.h" 35 36 #include <sys/param.h> 37 #include <sys/bus.h> 38 #include <sys/conf.h> 39 #include <sys/cpuset.h> 40 #include <sys/rtprio.h> 41 #include <sys/systm.h> 42 #include <sys/interrupt.h> 43 #include <sys/kernel.h> 44 #include <sys/kthread.h> 45 #include <sys/ktr.h> 46 #include <sys/limits.h> 47 #include <sys/lock.h> 48 #include <sys/malloc.h> 49 #include <sys/mutex.h> 50 #include <sys/priv.h> 51 #include <sys/proc.h> 52 #include <sys/epoch.h> 53 #include <sys/random.h> 54 #include <sys/resourcevar.h> 55 #include <sys/sched.h> 56 #include <sys/smp.h> 57 #include <sys/sysctl.h> 58 #include <sys/syslog.h> 59 #include <sys/unistd.h> 60 #include <sys/vmmeter.h> 61 #include <machine/atomic.h> 62 #include <machine/cpu.h> 63 #include <machine/md_var.h> 64 #include <machine/smp.h> 65 #include <machine/stdarg.h> 66 #ifdef DDB 67 #include <ddb/ddb.h> 68 #include <ddb/db_sym.h> 69 #endif 70 71 /* 72 * Describe an interrupt thread. There is one of these per interrupt event. 73 */ 74 struct intr_thread { 75 struct intr_event *it_event; 76 struct thread *it_thread; /* Kernel thread. */ 77 int it_flags; /* (j) IT_* flags. */ 78 int it_need; /* Needs service. */ 79 int it_waiting; /* Waiting in the runq. */ 80 }; 81 82 /* Interrupt thread flags kept in it_flags */ 83 #define IT_DEAD 0x000001 /* Thread is waiting to exit. */ 84 #define IT_WAIT 0x000002 /* Thread is waiting for completion. */ 85 86 struct intr_entropy { 87 struct thread *td; 88 uintptr_t event; 89 }; 90 91 struct intr_event *clk_intr_event; 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 #ifdef HWPMC_HOOKS 104 static int intr_hwpmc_waiting_report_threshold = 1; 105 SYSCTL_INT(_hw, OID_AUTO, intr_hwpmc_waiting_report_threshold, CTLFLAG_RWTUN, 106 &intr_hwpmc_waiting_report_threshold, 1, 107 "Threshold for reporting number of events in a workq"); 108 #define PMC_HOOK_INSTALLED_ANY() __predict_false(pmc_hook != NULL) 109 #endif 110 static TAILQ_HEAD(, intr_event) event_list = 111 TAILQ_HEAD_INITIALIZER(event_list); 112 static struct mtx event_lock; 113 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF); 114 115 static void intr_event_update(struct intr_event *ie); 116 static int intr_event_schedule_thread(struct intr_event *ie, struct trapframe *frame); 117 static struct intr_thread *ithread_create(const char *name); 118 static void ithread_destroy(struct intr_thread *ithread); 119 static void ithread_execute_handlers(struct proc *p, 120 struct intr_event *ie); 121 static void ithread_loop(void *); 122 static void ithread_update(struct intr_thread *ithd); 123 static void start_softintr(void *); 124 125 #ifdef HWPMC_HOOKS 126 #include <sys/pmckern.h> 127 PMC_SOFT_DEFINE( , , intr, all); 128 PMC_SOFT_DEFINE( , , intr, ithread); 129 PMC_SOFT_DEFINE( , , intr, filter); 130 PMC_SOFT_DEFINE( , , intr, stray); 131 PMC_SOFT_DEFINE( , , intr, schedule); 132 PMC_SOFT_DEFINE( , , intr, waiting); 133 134 #define PMC_SOFT_CALL_INTR_HLPR(event, frame) \ 135 do { \ 136 if (frame != NULL) \ 137 PMC_SOFT_CALL_TF( , , intr, event, frame); \ 138 else \ 139 PMC_SOFT_CALL( , , intr, event); \ 140 } while (0) 141 #endif 142 143 /* Map an interrupt type to an ithread priority. */ 144 u_char 145 intr_priority(enum intr_type flags) 146 { 147 u_char pri; 148 149 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET | 150 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV); 151 switch (flags) { 152 case INTR_TYPE_TTY: 153 pri = PI_TTY; 154 break; 155 case INTR_TYPE_BIO: 156 pri = PI_DISK; 157 break; 158 case INTR_TYPE_NET: 159 pri = PI_NET; 160 break; 161 case INTR_TYPE_CAM: 162 pri = PI_DISK; 163 break; 164 case INTR_TYPE_AV: 165 pri = PI_AV; 166 break; 167 case INTR_TYPE_CLK: 168 pri = PI_REALTIME; 169 break; 170 case INTR_TYPE_MISC: 171 pri = PI_DULL; /* don't care */ 172 break; 173 default: 174 /* We didn't specify an interrupt level. */ 175 panic("intr_priority: no interrupt type in flags"); 176 } 177 178 return pri; 179 } 180 181 /* 182 * Update an ithread based on the associated intr_event. 183 */ 184 static void 185 ithread_update(struct intr_thread *ithd) 186 { 187 struct intr_event *ie; 188 struct thread *td; 189 u_char pri; 190 191 ie = ithd->it_event; 192 td = ithd->it_thread; 193 mtx_assert(&ie->ie_lock, MA_OWNED); 194 195 /* Determine the overall priority of this event. */ 196 if (CK_SLIST_EMPTY(&ie->ie_handlers)) 197 pri = PRI_MAX_ITHD; 198 else 199 pri = CK_SLIST_FIRST(&ie->ie_handlers)->ih_pri; 200 201 /* Update name and priority. */ 202 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name)); 203 #ifdef KTR 204 sched_clear_tdname(td); 205 #endif 206 thread_lock(td); 207 sched_ithread_prio(td, pri); 208 thread_unlock(td); 209 } 210 211 /* 212 * Regenerate the full name of an interrupt event and update its priority. 213 */ 214 static void 215 intr_event_update(struct intr_event *ie) 216 { 217 struct intr_handler *ih; 218 char *last; 219 int missed, space, flags; 220 221 /* Start off with no entropy and just the name of the event. */ 222 mtx_assert(&ie->ie_lock, MA_OWNED); 223 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 224 flags = 0; 225 missed = 0; 226 space = 1; 227 228 /* Run through all the handlers updating values. */ 229 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 230 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 < 231 sizeof(ie->ie_fullname)) { 232 strcat(ie->ie_fullname, " "); 233 strcat(ie->ie_fullname, ih->ih_name); 234 space = 0; 235 } else 236 missed++; 237 flags |= ih->ih_flags; 238 } 239 ie->ie_hflags = flags; 240 241 /* 242 * If there is only one handler and its name is too long, just copy in 243 * as much of the end of the name (includes the unit number) as will 244 * fit. Otherwise, we have multiple handlers and not all of the names 245 * will fit. Add +'s to indicate missing names. If we run out of room 246 * and still have +'s to add, change the last character from a + to a *. 247 */ 248 if (missed == 1 && space == 1) { 249 ih = CK_SLIST_FIRST(&ie->ie_handlers); 250 missed = strlen(ie->ie_fullname) + strlen(ih->ih_name) + 2 - 251 sizeof(ie->ie_fullname); 252 strcat(ie->ie_fullname, (missed == 0) ? " " : "-"); 253 strcat(ie->ie_fullname, &ih->ih_name[missed]); 254 missed = 0; 255 } 256 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2]; 257 while (missed-- > 0) { 258 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) { 259 if (*last == '+') { 260 *last = '*'; 261 break; 262 } else 263 *last = '+'; 264 } else if (space) { 265 strcat(ie->ie_fullname, " +"); 266 space = 0; 267 } else 268 strcat(ie->ie_fullname, "+"); 269 } 270 271 /* 272 * If this event has an ithread, update it's priority and 273 * name. 274 */ 275 if (ie->ie_thread != NULL) 276 ithread_update(ie->ie_thread); 277 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname); 278 } 279 280 int 281 intr_event_create(struct intr_event **event, void *source, int flags, int irq, 282 void (*pre_ithread)(void *), void (*post_ithread)(void *), 283 void (*post_filter)(void *), int (*assign_cpu)(void *, int), 284 const char *fmt, ...) 285 { 286 struct intr_event *ie; 287 va_list ap; 288 289 /* The only valid flag during creation is IE_SOFT. */ 290 if ((flags & ~IE_SOFT) != 0) 291 return (EINVAL); 292 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO); 293 ie->ie_source = source; 294 ie->ie_pre_ithread = pre_ithread; 295 ie->ie_post_ithread = post_ithread; 296 ie->ie_post_filter = post_filter; 297 ie->ie_assign_cpu = assign_cpu; 298 ie->ie_flags = flags; 299 ie->ie_irq = irq; 300 ie->ie_cpu = NOCPU; 301 CK_SLIST_INIT(&ie->ie_handlers); 302 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF); 303 304 va_start(ap, fmt); 305 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap); 306 va_end(ap); 307 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 308 mtx_lock(&event_lock); 309 TAILQ_INSERT_TAIL(&event_list, ie, ie_list); 310 mtx_unlock(&event_lock); 311 if (event != NULL) 312 *event = ie; 313 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name); 314 return (0); 315 } 316 317 /* 318 * Bind an interrupt event to the specified CPU. Note that not all 319 * platforms support binding an interrupt to a CPU. For those 320 * platforms this request will fail. Using a cpu id of NOCPU unbinds 321 * the interrupt event. 322 */ 323 static int 324 _intr_event_bind(struct intr_event *ie, int cpu, bool bindirq, bool bindithread) 325 { 326 lwpid_t id; 327 int error; 328 329 /* Need a CPU to bind to. */ 330 if (cpu != NOCPU && CPU_ABSENT(cpu)) 331 return (EINVAL); 332 333 if (ie->ie_assign_cpu == NULL) 334 return (EOPNOTSUPP); 335 336 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR); 337 if (error) 338 return (error); 339 340 /* 341 * If we have any ithreads try to set their mask first to verify 342 * permissions, etc. 343 */ 344 if (bindithread) { 345 mtx_lock(&ie->ie_lock); 346 if (ie->ie_thread != NULL) { 347 id = ie->ie_thread->it_thread->td_tid; 348 mtx_unlock(&ie->ie_lock); 349 error = cpuset_setithread(id, cpu); 350 if (error) 351 return (error); 352 } else 353 mtx_unlock(&ie->ie_lock); 354 } 355 if (bindirq) 356 error = ie->ie_assign_cpu(ie->ie_source, cpu); 357 if (error) { 358 if (bindithread) { 359 mtx_lock(&ie->ie_lock); 360 if (ie->ie_thread != NULL) { 361 cpu = ie->ie_cpu; 362 id = ie->ie_thread->it_thread->td_tid; 363 mtx_unlock(&ie->ie_lock); 364 (void)cpuset_setithread(id, cpu); 365 } else 366 mtx_unlock(&ie->ie_lock); 367 } 368 return (error); 369 } 370 371 if (bindirq) { 372 mtx_lock(&ie->ie_lock); 373 ie->ie_cpu = cpu; 374 mtx_unlock(&ie->ie_lock); 375 } 376 377 return (error); 378 } 379 380 /* 381 * Bind an interrupt event to the specified CPU. For supported platforms, any 382 * associated ithreads as well as the primary interrupt context will be bound 383 * to the specificed CPU. 384 */ 385 int 386 intr_event_bind(struct intr_event *ie, int cpu) 387 { 388 389 return (_intr_event_bind(ie, cpu, true, true)); 390 } 391 392 /* 393 * Bind an interrupt event to the specified CPU, but do not bind associated 394 * ithreads. 395 */ 396 int 397 intr_event_bind_irqonly(struct intr_event *ie, int cpu) 398 { 399 400 return (_intr_event_bind(ie, cpu, true, false)); 401 } 402 403 /* 404 * Bind an interrupt event's ithread to the specified CPU. 405 */ 406 int 407 intr_event_bind_ithread(struct intr_event *ie, int cpu) 408 { 409 410 return (_intr_event_bind(ie, cpu, false, true)); 411 } 412 413 /* 414 * Bind an interrupt event's ithread to the specified cpuset. 415 */ 416 int 417 intr_event_bind_ithread_cpuset(struct intr_event *ie, cpuset_t *cs) 418 { 419 lwpid_t id; 420 421 mtx_lock(&ie->ie_lock); 422 if (ie->ie_thread != NULL) { 423 id = ie->ie_thread->it_thread->td_tid; 424 mtx_unlock(&ie->ie_lock); 425 return (cpuset_setthread(id, cs)); 426 } else { 427 mtx_unlock(&ie->ie_lock); 428 } 429 return (ENODEV); 430 } 431 432 static struct intr_event * 433 intr_lookup(int irq) 434 { 435 struct intr_event *ie; 436 437 mtx_lock(&event_lock); 438 TAILQ_FOREACH(ie, &event_list, ie_list) 439 if (ie->ie_irq == irq && 440 (ie->ie_flags & IE_SOFT) == 0 && 441 CK_SLIST_FIRST(&ie->ie_handlers) != NULL) 442 break; 443 mtx_unlock(&event_lock); 444 return (ie); 445 } 446 447 int 448 intr_setaffinity(int irq, int mode, void *m) 449 { 450 struct intr_event *ie; 451 cpuset_t *mask; 452 int cpu, n; 453 454 mask = m; 455 cpu = NOCPU; 456 /* 457 * If we're setting all cpus we can unbind. Otherwise make sure 458 * only one cpu is in the set. 459 */ 460 if (CPU_CMP(cpuset_root, mask)) { 461 for (n = 0; n < CPU_SETSIZE; n++) { 462 if (!CPU_ISSET(n, mask)) 463 continue; 464 if (cpu != NOCPU) 465 return (EINVAL); 466 cpu = n; 467 } 468 } 469 ie = intr_lookup(irq); 470 if (ie == NULL) 471 return (ESRCH); 472 switch (mode) { 473 case CPU_WHICH_IRQ: 474 return (intr_event_bind(ie, cpu)); 475 case CPU_WHICH_INTRHANDLER: 476 return (intr_event_bind_irqonly(ie, cpu)); 477 case CPU_WHICH_ITHREAD: 478 return (intr_event_bind_ithread(ie, cpu)); 479 default: 480 return (EINVAL); 481 } 482 } 483 484 int 485 intr_getaffinity(int irq, int mode, void *m) 486 { 487 struct intr_event *ie; 488 struct thread *td; 489 struct proc *p; 490 cpuset_t *mask; 491 lwpid_t id; 492 int error; 493 494 mask = m; 495 ie = intr_lookup(irq); 496 if (ie == NULL) 497 return (ESRCH); 498 499 error = 0; 500 CPU_ZERO(mask); 501 switch (mode) { 502 case CPU_WHICH_IRQ: 503 case CPU_WHICH_INTRHANDLER: 504 mtx_lock(&ie->ie_lock); 505 if (ie->ie_cpu == NOCPU) 506 CPU_COPY(cpuset_root, mask); 507 else 508 CPU_SET(ie->ie_cpu, mask); 509 mtx_unlock(&ie->ie_lock); 510 break; 511 case CPU_WHICH_ITHREAD: 512 mtx_lock(&ie->ie_lock); 513 if (ie->ie_thread == NULL) { 514 mtx_unlock(&ie->ie_lock); 515 CPU_COPY(cpuset_root, mask); 516 } else { 517 id = ie->ie_thread->it_thread->td_tid; 518 mtx_unlock(&ie->ie_lock); 519 error = cpuset_which(CPU_WHICH_TID, id, &p, &td, NULL); 520 if (error != 0) 521 return (error); 522 CPU_COPY(&td->td_cpuset->cs_mask, mask); 523 PROC_UNLOCK(p); 524 } 525 default: 526 return (EINVAL); 527 } 528 return (0); 529 } 530 531 int 532 intr_event_destroy(struct intr_event *ie) 533 { 534 535 if (ie == NULL) 536 return (EINVAL); 537 538 mtx_lock(&event_lock); 539 mtx_lock(&ie->ie_lock); 540 if (!CK_SLIST_EMPTY(&ie->ie_handlers)) { 541 mtx_unlock(&ie->ie_lock); 542 mtx_unlock(&event_lock); 543 return (EBUSY); 544 } 545 TAILQ_REMOVE(&event_list, ie, ie_list); 546 #ifndef notyet 547 if (ie->ie_thread != NULL) { 548 ithread_destroy(ie->ie_thread); 549 ie->ie_thread = NULL; 550 } 551 #endif 552 mtx_unlock(&ie->ie_lock); 553 mtx_unlock(&event_lock); 554 mtx_destroy(&ie->ie_lock); 555 free(ie, M_ITHREAD); 556 return (0); 557 } 558 559 static struct intr_thread * 560 ithread_create(const char *name) 561 { 562 struct intr_thread *ithd; 563 struct thread *td; 564 int error; 565 566 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 567 568 error = kproc_kthread_add(ithread_loop, ithd, &intrproc, 569 &td, RFSTOPPED | RFHIGHPID, 570 0, "intr", "%s", name); 571 if (error) 572 panic("kproc_create() failed with %d", error); 573 thread_lock(td); 574 sched_class(td, PRI_ITHD); 575 TD_SET_IWAIT(td); 576 thread_unlock(td); 577 td->td_pflags |= TDP_ITHREAD; 578 ithd->it_thread = td; 579 CTR2(KTR_INTR, "%s: created %s", __func__, name); 580 return (ithd); 581 } 582 583 static void 584 ithread_destroy(struct intr_thread *ithread) 585 { 586 struct thread *td; 587 588 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name); 589 td = ithread->it_thread; 590 thread_lock(td); 591 ithread->it_flags |= IT_DEAD; 592 if (TD_AWAITING_INTR(td)) { 593 TD_CLR_IWAIT(td); 594 sched_wakeup(td, SRQ_INTR); 595 } else 596 thread_unlock(td); 597 } 598 599 int 600 intr_event_add_handler(struct intr_event *ie, const char *name, 601 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 602 enum intr_type flags, void **cookiep) 603 { 604 struct intr_handler *ih, *temp_ih; 605 struct intr_handler **prevptr; 606 struct intr_thread *it; 607 608 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 609 return (EINVAL); 610 611 /* Allocate and populate an interrupt handler structure. */ 612 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 613 ih->ih_filter = filter; 614 ih->ih_handler = handler; 615 ih->ih_argument = arg; 616 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 617 ih->ih_event = ie; 618 ih->ih_pri = pri; 619 if (flags & INTR_EXCL) 620 ih->ih_flags = IH_EXCLUSIVE; 621 if (flags & INTR_MPSAFE) 622 ih->ih_flags |= IH_MPSAFE; 623 if (flags & INTR_ENTROPY) 624 ih->ih_flags |= IH_ENTROPY; 625 if (flags & INTR_TYPE_NET) 626 ih->ih_flags |= IH_NET; 627 628 /* We can only have one exclusive handler in a event. */ 629 mtx_lock(&ie->ie_lock); 630 if (!CK_SLIST_EMPTY(&ie->ie_handlers)) { 631 if ((flags & INTR_EXCL) || 632 (CK_SLIST_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 633 mtx_unlock(&ie->ie_lock); 634 free(ih, M_ITHREAD); 635 return (EINVAL); 636 } 637 } 638 639 /* Create a thread if we need one. */ 640 while (ie->ie_thread == NULL && handler != NULL) { 641 if (ie->ie_flags & IE_ADDING_THREAD) 642 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 643 else { 644 ie->ie_flags |= IE_ADDING_THREAD; 645 mtx_unlock(&ie->ie_lock); 646 it = ithread_create("intr: newborn"); 647 mtx_lock(&ie->ie_lock); 648 ie->ie_flags &= ~IE_ADDING_THREAD; 649 ie->ie_thread = it; 650 it->it_event = ie; 651 ithread_update(it); 652 wakeup(ie); 653 } 654 } 655 656 /* Add the new handler to the event in priority order. */ 657 CK_SLIST_FOREACH_PREVPTR(temp_ih, prevptr, &ie->ie_handlers, ih_next) { 658 if (temp_ih->ih_pri > ih->ih_pri) 659 break; 660 } 661 CK_SLIST_INSERT_PREVPTR(prevptr, temp_ih, ih, ih_next); 662 663 intr_event_update(ie); 664 665 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 666 ie->ie_name); 667 mtx_unlock(&ie->ie_lock); 668 669 if (cookiep != NULL) 670 *cookiep = ih; 671 return (0); 672 } 673 674 /* 675 * Append a description preceded by a ':' to the name of the specified 676 * interrupt handler. 677 */ 678 int 679 intr_event_describe_handler(struct intr_event *ie, void *cookie, 680 const char *descr) 681 { 682 struct intr_handler *ih; 683 size_t space; 684 char *start; 685 686 mtx_lock(&ie->ie_lock); 687 #ifdef INVARIANTS 688 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 689 if (ih == cookie) 690 break; 691 } 692 if (ih == NULL) { 693 mtx_unlock(&ie->ie_lock); 694 panic("handler %p not found in interrupt event %p", cookie, ie); 695 } 696 #endif 697 ih = cookie; 698 699 /* 700 * Look for an existing description by checking for an 701 * existing ":". This assumes device names do not include 702 * colons. If one is found, prepare to insert the new 703 * description at that point. If one is not found, find the 704 * end of the name to use as the insertion point. 705 */ 706 start = strchr(ih->ih_name, ':'); 707 if (start == NULL) 708 start = strchr(ih->ih_name, 0); 709 710 /* 711 * See if there is enough remaining room in the string for the 712 * description + ":". The "- 1" leaves room for the trailing 713 * '\0'. The "+ 1" accounts for the colon. 714 */ 715 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1; 716 if (strlen(descr) + 1 > space) { 717 mtx_unlock(&ie->ie_lock); 718 return (ENOSPC); 719 } 720 721 /* Append a colon followed by the description. */ 722 *start = ':'; 723 strcpy(start + 1, descr); 724 intr_event_update(ie); 725 mtx_unlock(&ie->ie_lock); 726 return (0); 727 } 728 729 /* 730 * Return the ie_source field from the intr_event an intr_handler is 731 * associated with. 732 */ 733 void * 734 intr_handler_source(void *cookie) 735 { 736 struct intr_handler *ih; 737 struct intr_event *ie; 738 739 ih = (struct intr_handler *)cookie; 740 if (ih == NULL) 741 return (NULL); 742 ie = ih->ih_event; 743 KASSERT(ie != NULL, 744 ("interrupt handler \"%s\" has a NULL interrupt event", 745 ih->ih_name)); 746 return (ie->ie_source); 747 } 748 749 /* 750 * If intr_event_handle() is running in the ISR context at the time of the call, 751 * then wait for it to complete. 752 */ 753 static void 754 intr_event_barrier(struct intr_event *ie) 755 { 756 int phase; 757 758 mtx_assert(&ie->ie_lock, MA_OWNED); 759 phase = ie->ie_phase; 760 761 /* 762 * Switch phase to direct future interrupts to the other active counter. 763 * Make sure that any preceding stores are visible before the switch. 764 */ 765 KASSERT(ie->ie_active[!phase] == 0, ("idle phase has activity")); 766 atomic_store_rel_int(&ie->ie_phase, !phase); 767 768 /* 769 * This code cooperates with wait-free iteration of ie_handlers 770 * in intr_event_handle. 771 * Make sure that the removal and the phase update are not reordered 772 * with the active count check. 773 * Note that no combination of acquire and release fences can provide 774 * that guarantee as Store->Load sequences can always be reordered. 775 */ 776 atomic_thread_fence_seq_cst(); 777 778 /* 779 * Now wait on the inactive phase. 780 * The acquire fence is needed so that all post-barrier accesses 781 * are after the check. 782 */ 783 while (ie->ie_active[phase] > 0) 784 cpu_spinwait(); 785 atomic_thread_fence_acq(); 786 } 787 788 static void 789 intr_handler_barrier(struct intr_handler *handler) 790 { 791 struct intr_event *ie; 792 793 ie = handler->ih_event; 794 mtx_assert(&ie->ie_lock, MA_OWNED); 795 KASSERT((handler->ih_flags & IH_DEAD) == 0, 796 ("update for a removed handler")); 797 798 if (ie->ie_thread == NULL) { 799 intr_event_barrier(ie); 800 return; 801 } 802 if ((handler->ih_flags & IH_CHANGED) == 0) { 803 handler->ih_flags |= IH_CHANGED; 804 intr_event_schedule_thread(ie, NULL); 805 } 806 while ((handler->ih_flags & IH_CHANGED) != 0) 807 msleep(handler, &ie->ie_lock, 0, "ih_barr", 0); 808 } 809 810 /* 811 * Sleep until an ithread finishes executing an interrupt handler. 812 * 813 * XXX Doesn't currently handle interrupt filters or fast interrupt 814 * handlers. This is intended for LinuxKPI drivers only. 815 * Do not use in BSD code. 816 */ 817 void 818 _intr_drain(int irq) 819 { 820 struct intr_event *ie; 821 struct intr_thread *ithd; 822 struct thread *td; 823 824 ie = intr_lookup(irq); 825 if (ie == NULL) 826 return; 827 if (ie->ie_thread == NULL) 828 return; 829 ithd = ie->ie_thread; 830 td = ithd->it_thread; 831 /* 832 * We set the flag and wait for it to be cleared to avoid 833 * long delays with potentially busy interrupt handlers 834 * were we to only sample TD_AWAITING_INTR() every tick. 835 */ 836 thread_lock(td); 837 if (!TD_AWAITING_INTR(td)) { 838 ithd->it_flags |= IT_WAIT; 839 while (ithd->it_flags & IT_WAIT) { 840 thread_unlock(td); 841 pause("idrain", 1); 842 thread_lock(td); 843 } 844 } 845 thread_unlock(td); 846 return; 847 } 848 849 int 850 intr_event_remove_handler(void *cookie) 851 { 852 struct intr_handler *handler = (struct intr_handler *)cookie; 853 struct intr_event *ie; 854 struct intr_handler *ih; 855 struct intr_handler **prevptr; 856 #ifdef notyet 857 int dead; 858 #endif 859 860 if (handler == NULL) 861 return (EINVAL); 862 ie = handler->ih_event; 863 KASSERT(ie != NULL, 864 ("interrupt handler \"%s\" has a NULL interrupt event", 865 handler->ih_name)); 866 867 mtx_lock(&ie->ie_lock); 868 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 869 ie->ie_name); 870 CK_SLIST_FOREACH_PREVPTR(ih, prevptr, &ie->ie_handlers, ih_next) { 871 if (ih == handler) 872 break; 873 } 874 if (ih == NULL) { 875 panic("interrupt handler \"%s\" not found in " 876 "interrupt event \"%s\"", handler->ih_name, ie->ie_name); 877 } 878 879 /* 880 * If there is no ithread, then directly remove the handler. Note that 881 * intr_event_handle() iterates ie_handlers in a lock-less fashion, so 882 * care needs to be taken to keep ie_handlers consistent and to free 883 * the removed handler only when ie_handlers is quiescent. 884 */ 885 if (ie->ie_thread == NULL) { 886 CK_SLIST_REMOVE_PREVPTR(prevptr, ih, ih_next); 887 intr_event_barrier(ie); 888 intr_event_update(ie); 889 mtx_unlock(&ie->ie_lock); 890 free(handler, M_ITHREAD); 891 return (0); 892 } 893 894 /* 895 * Let the interrupt thread do the job. 896 * The interrupt source is disabled when the interrupt thread is 897 * running, so it does not have to worry about interaction with 898 * intr_event_handle(). 899 */ 900 KASSERT((handler->ih_flags & IH_DEAD) == 0, 901 ("duplicate handle remove")); 902 handler->ih_flags |= IH_DEAD; 903 intr_event_schedule_thread(ie, NULL); 904 while (handler->ih_flags & IH_DEAD) 905 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 906 intr_event_update(ie); 907 908 #ifdef notyet 909 /* 910 * XXX: This could be bad in the case of ppbus(8). Also, I think 911 * this could lead to races of stale data when servicing an 912 * interrupt. 913 */ 914 dead = 1; 915 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 916 if (ih->ih_handler != NULL) { 917 dead = 0; 918 break; 919 } 920 } 921 if (dead) { 922 ithread_destroy(ie->ie_thread); 923 ie->ie_thread = NULL; 924 } 925 #endif 926 mtx_unlock(&ie->ie_lock); 927 free(handler, M_ITHREAD); 928 return (0); 929 } 930 931 int 932 intr_event_suspend_handler(void *cookie) 933 { 934 struct intr_handler *handler = (struct intr_handler *)cookie; 935 struct intr_event *ie; 936 937 if (handler == NULL) 938 return (EINVAL); 939 ie = handler->ih_event; 940 KASSERT(ie != NULL, 941 ("interrupt handler \"%s\" has a NULL interrupt event", 942 handler->ih_name)); 943 mtx_lock(&ie->ie_lock); 944 handler->ih_flags |= IH_SUSP; 945 intr_handler_barrier(handler); 946 mtx_unlock(&ie->ie_lock); 947 return (0); 948 } 949 950 int 951 intr_event_resume_handler(void *cookie) 952 { 953 struct intr_handler *handler = (struct intr_handler *)cookie; 954 struct intr_event *ie; 955 956 if (handler == NULL) 957 return (EINVAL); 958 ie = handler->ih_event; 959 KASSERT(ie != NULL, 960 ("interrupt handler \"%s\" has a NULL interrupt event", 961 handler->ih_name)); 962 963 /* 964 * intr_handler_barrier() acts not only as a barrier, 965 * it also allows to check for any pending interrupts. 966 */ 967 mtx_lock(&ie->ie_lock); 968 handler->ih_flags &= ~IH_SUSP; 969 intr_handler_barrier(handler); 970 mtx_unlock(&ie->ie_lock); 971 return (0); 972 } 973 974 static int 975 intr_event_schedule_thread(struct intr_event *ie, struct trapframe *frame) 976 { 977 struct intr_entropy entropy; 978 struct intr_thread *it; 979 struct thread *td; 980 struct thread *ctd; 981 982 /* 983 * If no ithread or no handlers, then we have a stray interrupt. 984 */ 985 if (ie == NULL || CK_SLIST_EMPTY(&ie->ie_handlers) || 986 ie->ie_thread == NULL) 987 return (EINVAL); 988 989 ctd = curthread; 990 it = ie->ie_thread; 991 td = it->it_thread; 992 993 /* 994 * If any of the handlers for this ithread claim to be good 995 * sources of entropy, then gather some. 996 */ 997 if (ie->ie_hflags & IH_ENTROPY) { 998 entropy.event = (uintptr_t)ie; 999 entropy.td = ctd; 1000 random_harvest_queue(&entropy, sizeof(entropy), RANDOM_INTERRUPT); 1001 } 1002 1003 KASSERT(td->td_proc != NULL, ("ithread %s has no process", ie->ie_name)); 1004 1005 /* 1006 * Set it_need to tell the thread to keep running if it is already 1007 * running. Then, lock the thread and see if we actually need to 1008 * put it on the runqueue. 1009 * 1010 * Use store_rel to arrange that the store to ih_need in 1011 * swi_sched() is before the store to it_need and prepare for 1012 * transfer of this order to loads in the ithread. 1013 */ 1014 atomic_store_rel_int(&it->it_need, 1); 1015 thread_lock(td); 1016 if (TD_AWAITING_INTR(td)) { 1017 #ifdef HWPMC_HOOKS 1018 it->it_waiting = 0; 1019 if (PMC_HOOK_INSTALLED_ANY()) 1020 PMC_SOFT_CALL_INTR_HLPR(schedule, frame); 1021 #endif 1022 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, td->td_proc->p_pid, 1023 td->td_name); 1024 TD_CLR_IWAIT(td); 1025 sched_wakeup(td, SRQ_INTR); 1026 } else { 1027 #ifdef HWPMC_HOOKS 1028 it->it_waiting++; 1029 if (PMC_HOOK_INSTALLED_ANY() && 1030 (it->it_waiting >= intr_hwpmc_waiting_report_threshold)) 1031 PMC_SOFT_CALL_INTR_HLPR(waiting, frame); 1032 #endif 1033 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 1034 __func__, td->td_proc->p_pid, td->td_name, it->it_need, TD_GET_STATE(td)); 1035 thread_unlock(td); 1036 } 1037 1038 return (0); 1039 } 1040 1041 /* 1042 * Allow interrupt event binding for software interrupt handlers -- a no-op, 1043 * since interrupts are generated in software rather than being directed by 1044 * a PIC. 1045 */ 1046 static int 1047 swi_assign_cpu(void *arg, int cpu) 1048 { 1049 1050 return (0); 1051 } 1052 1053 /* 1054 * Add a software interrupt handler to a specified event. If a given event 1055 * is not specified, then a new event is created. 1056 */ 1057 int 1058 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler, 1059 void *arg, int pri, enum intr_type flags, void **cookiep) 1060 { 1061 struct intr_event *ie; 1062 int error = 0; 1063 1064 if (flags & INTR_ENTROPY) 1065 return (EINVAL); 1066 1067 ie = (eventp != NULL) ? *eventp : NULL; 1068 1069 if (ie != NULL) { 1070 if (!(ie->ie_flags & IE_SOFT)) 1071 return (EINVAL); 1072 } else { 1073 error = intr_event_create(&ie, NULL, IE_SOFT, 0, 1074 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri); 1075 if (error) 1076 return (error); 1077 if (eventp != NULL) 1078 *eventp = ie; 1079 } 1080 if (handler != NULL) { 1081 error = intr_event_add_handler(ie, name, NULL, handler, arg, 1082 PI_SWI(pri), flags, cookiep); 1083 } 1084 return (error); 1085 } 1086 1087 /* 1088 * Schedule a software interrupt thread. 1089 */ 1090 void 1091 swi_sched(void *cookie, int flags) 1092 { 1093 struct intr_handler *ih = (struct intr_handler *)cookie; 1094 struct intr_event *ie = ih->ih_event; 1095 struct intr_entropy entropy; 1096 int error __unused; 1097 1098 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name, 1099 ih->ih_need); 1100 1101 if ((flags & SWI_FROMNMI) == 0) { 1102 entropy.event = (uintptr_t)ih; 1103 entropy.td = curthread; 1104 random_harvest_queue(&entropy, sizeof(entropy), RANDOM_SWI); 1105 } 1106 1107 /* 1108 * Set ih_need for this handler so that if the ithread is already 1109 * running it will execute this handler on the next pass. Otherwise, 1110 * it will execute it the next time it runs. 1111 */ 1112 ih->ih_need = 1; 1113 1114 if (flags & SWI_DELAY) 1115 return; 1116 1117 if (flags & SWI_FROMNMI) { 1118 #if defined(SMP) && (defined(__i386__) || defined(__amd64__)) 1119 KASSERT(ie == clk_intr_event, 1120 ("SWI_FROMNMI used not with clk_intr_event")); 1121 ipi_self_from_nmi(IPI_SWI); 1122 #endif 1123 } else { 1124 VM_CNT_INC(v_soft); 1125 error = intr_event_schedule_thread(ie, NULL); 1126 KASSERT(error == 0, ("stray software interrupt")); 1127 } 1128 } 1129 1130 /* 1131 * Remove a software interrupt handler. Currently this code does not 1132 * remove the associated interrupt event if it becomes empty. Calling code 1133 * may do so manually via intr_event_destroy(), but that's not really 1134 * an optimal interface. 1135 */ 1136 int 1137 swi_remove(void *cookie) 1138 { 1139 1140 return (intr_event_remove_handler(cookie)); 1141 } 1142 1143 static void 1144 intr_event_execute_handlers(struct proc *p, struct intr_event *ie) 1145 { 1146 struct intr_handler *ih, *ihn, *ihp; 1147 1148 ihp = NULL; 1149 CK_SLIST_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) { 1150 /* 1151 * If this handler is marked for death, remove it from 1152 * the list of handlers and wake up the sleeper. 1153 */ 1154 if (ih->ih_flags & IH_DEAD) { 1155 mtx_lock(&ie->ie_lock); 1156 if (ihp == NULL) 1157 CK_SLIST_REMOVE_HEAD(&ie->ie_handlers, ih_next); 1158 else 1159 CK_SLIST_REMOVE_AFTER(ihp, ih_next); 1160 ih->ih_flags &= ~IH_DEAD; 1161 wakeup(ih); 1162 mtx_unlock(&ie->ie_lock); 1163 continue; 1164 } 1165 1166 /* 1167 * Now that we know that the current element won't be removed 1168 * update the previous element. 1169 */ 1170 ihp = ih; 1171 1172 if ((ih->ih_flags & IH_CHANGED) != 0) { 1173 mtx_lock(&ie->ie_lock); 1174 ih->ih_flags &= ~IH_CHANGED; 1175 wakeup(ih); 1176 mtx_unlock(&ie->ie_lock); 1177 } 1178 1179 /* Skip filter only handlers */ 1180 if (ih->ih_handler == NULL) 1181 continue; 1182 1183 /* Skip suspended handlers */ 1184 if ((ih->ih_flags & IH_SUSP) != 0) 1185 continue; 1186 1187 /* 1188 * For software interrupt threads, we only execute 1189 * handlers that have their need flag set. Hardware 1190 * interrupt threads always invoke all of their handlers. 1191 * 1192 * ih_need can only be 0 or 1. Failed cmpset below 1193 * means that there is no request to execute handlers, 1194 * so a retry of the cmpset is not needed. 1195 */ 1196 if ((ie->ie_flags & IE_SOFT) != 0 && 1197 atomic_cmpset_int(&ih->ih_need, 1, 0) == 0) 1198 continue; 1199 1200 /* Execute this handler. */ 1201 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1202 __func__, p->p_pid, (void *)ih->ih_handler, 1203 ih->ih_argument, ih->ih_name, ih->ih_flags); 1204 1205 if (!(ih->ih_flags & IH_MPSAFE)) 1206 mtx_lock(&Giant); 1207 ih->ih_handler(ih->ih_argument); 1208 if (!(ih->ih_flags & IH_MPSAFE)) 1209 mtx_unlock(&Giant); 1210 } 1211 } 1212 1213 static void 1214 ithread_execute_handlers(struct proc *p, struct intr_event *ie) 1215 { 1216 1217 /* Interrupt handlers should not sleep. */ 1218 if (!(ie->ie_flags & IE_SOFT)) 1219 THREAD_NO_SLEEPING(); 1220 intr_event_execute_handlers(p, ie); 1221 if (!(ie->ie_flags & IE_SOFT)) 1222 THREAD_SLEEPING_OK(); 1223 1224 /* 1225 * Interrupt storm handling: 1226 * 1227 * If this interrupt source is currently storming, then throttle 1228 * it to only fire the handler once per clock tick. 1229 * 1230 * If this interrupt source is not currently storming, but the 1231 * number of back to back interrupts exceeds the storm threshold, 1232 * then enter storming mode. 1233 */ 1234 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold && 1235 !(ie->ie_flags & IE_SOFT)) { 1236 /* Report the message only once every second. */ 1237 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) { 1238 printf( 1239 "interrupt storm detected on \"%s\"; throttling interrupt source\n", 1240 ie->ie_name); 1241 } 1242 pause("istorm", 1); 1243 } else 1244 ie->ie_count++; 1245 1246 /* 1247 * Now that all the handlers have had a chance to run, reenable 1248 * the interrupt source. 1249 */ 1250 if (ie->ie_post_ithread != NULL) 1251 ie->ie_post_ithread(ie->ie_source); 1252 } 1253 1254 /* 1255 * This is the main code for interrupt threads. 1256 */ 1257 static void 1258 ithread_loop(void *arg) 1259 { 1260 struct epoch_tracker et; 1261 struct intr_thread *ithd; 1262 struct intr_event *ie; 1263 struct thread *td; 1264 struct proc *p; 1265 int wake, epoch_count; 1266 bool needs_epoch; 1267 1268 td = curthread; 1269 p = td->td_proc; 1270 ithd = (struct intr_thread *)arg; 1271 KASSERT(ithd->it_thread == td, 1272 ("%s: ithread and proc linkage out of sync", __func__)); 1273 ie = ithd->it_event; 1274 ie->ie_count = 0; 1275 wake = 0; 1276 1277 /* 1278 * As long as we have interrupts outstanding, go through the 1279 * list of handlers, giving each one a go at it. 1280 */ 1281 for (;;) { 1282 /* 1283 * If we are an orphaned thread, then just die. 1284 */ 1285 if (ithd->it_flags & IT_DEAD) { 1286 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1287 p->p_pid, td->td_name); 1288 free(ithd, M_ITHREAD); 1289 kthread_exit(); 1290 } 1291 1292 /* 1293 * Service interrupts. If another interrupt arrives while 1294 * we are running, it will set it_need to note that we 1295 * should make another pass. 1296 * 1297 * The load_acq part of the following cmpset ensures 1298 * that the load of ih_need in ithread_execute_handlers() 1299 * is ordered after the load of it_need here. 1300 */ 1301 needs_epoch = 1302 (atomic_load_int(&ie->ie_hflags) & IH_NET) != 0; 1303 if (needs_epoch) { 1304 epoch_count = 0; 1305 NET_EPOCH_ENTER(et); 1306 } 1307 while (atomic_cmpset_acq_int(&ithd->it_need, 1, 0) != 0) { 1308 ithread_execute_handlers(p, ie); 1309 if (needs_epoch && 1310 ++epoch_count >= intr_epoch_batch) { 1311 NET_EPOCH_EXIT(et); 1312 epoch_count = 0; 1313 NET_EPOCH_ENTER(et); 1314 } 1315 } 1316 if (needs_epoch) 1317 NET_EPOCH_EXIT(et); 1318 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1319 mtx_assert(&Giant, MA_NOTOWNED); 1320 1321 /* 1322 * Processed all our interrupts. Now get the sched 1323 * lock. This may take a while and it_need may get 1324 * set again, so we have to check it again. 1325 */ 1326 thread_lock(td); 1327 if (atomic_load_acq_int(&ithd->it_need) == 0 && 1328 (ithd->it_flags & (IT_DEAD | IT_WAIT)) == 0) { 1329 TD_SET_IWAIT(td); 1330 ie->ie_count = 0; 1331 mi_switch(SW_VOL | SWT_IWAIT); 1332 } else { 1333 if (ithd->it_flags & IT_WAIT) { 1334 wake = 1; 1335 ithd->it_flags &= ~IT_WAIT; 1336 } 1337 thread_unlock(td); 1338 } 1339 if (wake) { 1340 wakeup(ithd); 1341 wake = 0; 1342 } 1343 } 1344 } 1345 1346 /* 1347 * Main interrupt handling body. 1348 * 1349 * Input: 1350 * o ie: the event connected to this interrupt. 1351 * o frame: some archs (i.e. i386) pass a frame to some. 1352 * handlers as their main argument. 1353 * Return value: 1354 * o 0: everything ok. 1355 * o EINVAL: stray interrupt. 1356 */ 1357 int 1358 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1359 { 1360 struct intr_handler *ih; 1361 struct trapframe *oldframe; 1362 struct thread *td; 1363 int phase; 1364 int ret; 1365 bool filter, thread; 1366 1367 td = curthread; 1368 1369 #ifdef KSTACK_USAGE_PROF 1370 intr_prof_stack_use(td, frame); 1371 #endif 1372 1373 /* An interrupt with no event or handlers is a stray interrupt. */ 1374 if (ie == NULL || CK_SLIST_EMPTY(&ie->ie_handlers)) 1375 return (EINVAL); 1376 1377 /* 1378 * Execute fast interrupt handlers directly. 1379 * To support clock handlers, if a handler registers 1380 * with a NULL argument, then we pass it a pointer to 1381 * a trapframe as its argument. 1382 */ 1383 td->td_intr_nesting_level++; 1384 filter = false; 1385 thread = false; 1386 ret = 0; 1387 critical_enter(); 1388 oldframe = td->td_intr_frame; 1389 td->td_intr_frame = frame; 1390 1391 phase = ie->ie_phase; 1392 atomic_add_int(&ie->ie_active[phase], 1); 1393 1394 /* 1395 * This fence is required to ensure that no later loads are 1396 * re-ordered before the ie_active store. 1397 */ 1398 atomic_thread_fence_seq_cst(); 1399 1400 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 1401 if ((ih->ih_flags & IH_SUSP) != 0) 1402 continue; 1403 if ((ie->ie_flags & IE_SOFT) != 0 && ih->ih_need == 0) 1404 continue; 1405 if (ih->ih_filter == NULL) { 1406 thread = true; 1407 continue; 1408 } 1409 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__, 1410 ih->ih_filter, ih->ih_argument == NULL ? frame : 1411 ih->ih_argument, ih->ih_name); 1412 if (ih->ih_argument == NULL) 1413 ret = ih->ih_filter(frame); 1414 else 1415 ret = ih->ih_filter(ih->ih_argument); 1416 #ifdef HWPMC_HOOKS 1417 PMC_SOFT_CALL_TF( , , intr, all, frame); 1418 #endif 1419 KASSERT(ret == FILTER_STRAY || 1420 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1421 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1422 ("%s: incorrect return value %#x from %s", __func__, ret, 1423 ih->ih_name)); 1424 filter = filter || ret == FILTER_HANDLED; 1425 #ifdef HWPMC_HOOKS 1426 if (ret & FILTER_SCHEDULE_THREAD) 1427 PMC_SOFT_CALL_TF( , , intr, ithread, frame); 1428 else if (ret & FILTER_HANDLED) 1429 PMC_SOFT_CALL_TF( , , intr, filter, frame); 1430 else if (ret == FILTER_STRAY) 1431 PMC_SOFT_CALL_TF( , , intr, stray, frame); 1432 #endif 1433 1434 /* 1435 * Wrapper handler special handling: 1436 * 1437 * in some particular cases (like pccard and pccbb), 1438 * the _real_ device handler is wrapped in a couple of 1439 * functions - a filter wrapper and an ithread wrapper. 1440 * In this case (and just in this case), the filter wrapper 1441 * could ask the system to schedule the ithread and mask 1442 * the interrupt source if the wrapped handler is composed 1443 * of just an ithread handler. 1444 * 1445 * TODO: write a generic wrapper to avoid people rolling 1446 * their own. 1447 */ 1448 if (!thread) { 1449 if (ret == FILTER_SCHEDULE_THREAD) 1450 thread = true; 1451 } 1452 } 1453 atomic_add_rel_int(&ie->ie_active[phase], -1); 1454 1455 td->td_intr_frame = oldframe; 1456 1457 if (thread) { 1458 if (ie->ie_pre_ithread != NULL) 1459 ie->ie_pre_ithread(ie->ie_source); 1460 } else { 1461 if (ie->ie_post_filter != NULL) 1462 ie->ie_post_filter(ie->ie_source); 1463 } 1464 1465 /* Schedule the ithread if needed. */ 1466 if (thread) { 1467 int error __unused; 1468 1469 error = intr_event_schedule_thread(ie, frame); 1470 KASSERT(error == 0, ("bad stray interrupt")); 1471 } 1472 critical_exit(); 1473 td->td_intr_nesting_level--; 1474 #ifdef notyet 1475 /* The interrupt is not aknowledged by any filter and has no ithread. */ 1476 if (!thread && !filter) 1477 return (EINVAL); 1478 #endif 1479 return (0); 1480 } 1481 1482 #ifdef DDB 1483 /* 1484 * Dump details about an interrupt handler 1485 */ 1486 static void 1487 db_dump_intrhand(struct intr_handler *ih) 1488 { 1489 int comma; 1490 1491 db_printf("\t%-10s ", ih->ih_name); 1492 switch (ih->ih_pri) { 1493 case PI_REALTIME: 1494 db_printf("CLK "); 1495 break; 1496 case PI_INTR: 1497 db_printf("INTR"); 1498 break; 1499 default: 1500 if (ih->ih_pri >= PI_SOFT) 1501 db_printf("SWI "); 1502 else 1503 db_printf("%4u", ih->ih_pri); 1504 break; 1505 } 1506 db_printf(" "); 1507 if (ih->ih_filter != NULL) { 1508 db_printf("[F]"); 1509 db_printsym((uintptr_t)ih->ih_filter, DB_STGY_PROC); 1510 } 1511 if (ih->ih_handler != NULL) { 1512 if (ih->ih_filter != NULL) 1513 db_printf(","); 1514 db_printf("[H]"); 1515 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC); 1516 } 1517 db_printf("(%p)", ih->ih_argument); 1518 if (ih->ih_need || 1519 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD | 1520 IH_MPSAFE)) != 0) { 1521 db_printf(" {"); 1522 comma = 0; 1523 if (ih->ih_flags & IH_EXCLUSIVE) { 1524 if (comma) 1525 db_printf(", "); 1526 db_printf("EXCL"); 1527 comma = 1; 1528 } 1529 if (ih->ih_flags & IH_ENTROPY) { 1530 if (comma) 1531 db_printf(", "); 1532 db_printf("ENTROPY"); 1533 comma = 1; 1534 } 1535 if (ih->ih_flags & IH_DEAD) { 1536 if (comma) 1537 db_printf(", "); 1538 db_printf("DEAD"); 1539 comma = 1; 1540 } 1541 if (ih->ih_flags & IH_MPSAFE) { 1542 if (comma) 1543 db_printf(", "); 1544 db_printf("MPSAFE"); 1545 comma = 1; 1546 } 1547 if (ih->ih_need) { 1548 if (comma) 1549 db_printf(", "); 1550 db_printf("NEED"); 1551 } 1552 db_printf("}"); 1553 } 1554 db_printf("\n"); 1555 } 1556 1557 /* 1558 * Dump details about a event. 1559 */ 1560 void 1561 db_dump_intr_event(struct intr_event *ie, int handlers) 1562 { 1563 struct intr_handler *ih; 1564 struct intr_thread *it; 1565 int comma; 1566 1567 db_printf("%s ", ie->ie_fullname); 1568 it = ie->ie_thread; 1569 if (it != NULL) 1570 db_printf("(pid %d)", it->it_thread->td_proc->p_pid); 1571 else 1572 db_printf("(no thread)"); 1573 if ((ie->ie_flags & (IE_SOFT | IE_ADDING_THREAD)) != 0 || 1574 (it != NULL && it->it_need)) { 1575 db_printf(" {"); 1576 comma = 0; 1577 if (ie->ie_flags & IE_SOFT) { 1578 db_printf("SOFT"); 1579 comma = 1; 1580 } 1581 if (ie->ie_flags & IE_ADDING_THREAD) { 1582 if (comma) 1583 db_printf(", "); 1584 db_printf("ADDING_THREAD"); 1585 comma = 1; 1586 } 1587 if (it != NULL && it->it_need) { 1588 if (comma) 1589 db_printf(", "); 1590 db_printf("NEED"); 1591 } 1592 db_printf("}"); 1593 } 1594 db_printf("\n"); 1595 1596 if (handlers) 1597 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) 1598 db_dump_intrhand(ih); 1599 } 1600 1601 /* 1602 * Dump data about interrupt handlers 1603 */ 1604 DB_SHOW_COMMAND_FLAGS(intr, db_show_intr, DB_CMD_MEMSAFE) 1605 { 1606 struct intr_event *ie; 1607 int all, verbose; 1608 1609 verbose = strchr(modif, 'v') != NULL; 1610 all = strchr(modif, 'a') != NULL; 1611 TAILQ_FOREACH(ie, &event_list, ie_list) { 1612 if (!all && CK_SLIST_EMPTY(&ie->ie_handlers)) 1613 continue; 1614 db_dump_intr_event(ie, verbose); 1615 if (db_pager_quit) 1616 break; 1617 } 1618 } 1619 #endif /* DDB */ 1620 1621 /* 1622 * Start standard software interrupt threads 1623 */ 1624 static void 1625 start_softintr(void *dummy) 1626 { 1627 1628 if (swi_add(&clk_intr_event, "clk", NULL, NULL, SWI_CLOCK, 1629 INTR_MPSAFE, NULL)) 1630 panic("died while creating clk swi ithread"); 1631 } 1632 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, 1633 NULL); 1634 1635 /* 1636 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. 1637 * The data for this machine dependent, and the declarations are in machine 1638 * dependent code. The layout of intrnames and intrcnt however is machine 1639 * independent. 1640 * 1641 * We do not know the length of intrcnt and intrnames at compile time, so 1642 * calculate things at run time. 1643 */ 1644 static int 1645 sysctl_intrnames(SYSCTL_HANDLER_ARGS) 1646 { 1647 return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req)); 1648 } 1649 1650 SYSCTL_PROC(_hw, OID_AUTO, intrnames, 1651 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 1652 sysctl_intrnames, "", 1653 "Interrupt Names"); 1654 1655 static int 1656 sysctl_intrcnt(SYSCTL_HANDLER_ARGS) 1657 { 1658 #ifdef SCTL_MASK32 1659 uint32_t *intrcnt32; 1660 unsigned i; 1661 int error; 1662 1663 if (req->flags & SCTL_MASK32) { 1664 if (!req->oldptr) 1665 return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req)); 1666 intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT); 1667 if (intrcnt32 == NULL) 1668 return (ENOMEM); 1669 for (i = 0; i < sintrcnt / sizeof (u_long); i++) 1670 intrcnt32[i] = intrcnt[i]; 1671 error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req); 1672 free(intrcnt32, M_TEMP); 1673 return (error); 1674 } 1675 #endif 1676 return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req)); 1677 } 1678 1679 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, 1680 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 1681 sysctl_intrcnt, "", 1682 "Interrupt Counts"); 1683 1684 #ifdef DDB 1685 /* 1686 * DDB command to dump the interrupt statistics. 1687 */ 1688 DB_SHOW_COMMAND_FLAGS(intrcnt, db_show_intrcnt, DB_CMD_MEMSAFE) 1689 { 1690 u_long *i; 1691 char *cp; 1692 u_int j; 1693 1694 cp = intrnames; 1695 j = 0; 1696 for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit; 1697 i++, j++) { 1698 if (*cp == '\0') 1699 break; 1700 if (*i != 0) 1701 db_printf("%s\t%lu\n", cp, *i); 1702 cp += strlen(cp) + 1; 1703 } 1704 } 1705 #endif
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