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 intr_event *tty_intr_event; 93 void *vm_ih; 94 struct proc *intrproc; 95 96 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads"); 97 98 static int intr_storm_threshold = 0; 99 SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RWTUN, 100 &intr_storm_threshold, 0, 101 "Number of consecutive interrupts before storm protection is enabled"); 102 static int intr_epoch_batch = 1000; 103 SYSCTL_INT(_hw, OID_AUTO, intr_epoch_batch, CTLFLAG_RWTUN, &intr_epoch_batch, 104 0, "Maximum interrupt handler executions without re-entering epoch(9)"); 105 #ifdef HWPMC_HOOKS 106 static int intr_hwpmc_waiting_report_threshold = 1; 107 SYSCTL_INT(_hw, OID_AUTO, intr_hwpmc_waiting_report_threshold, CTLFLAG_RWTUN, 108 &intr_hwpmc_waiting_report_threshold, 1, 109 "Threshold for reporting number of events in a workq"); 110 #endif 111 static TAILQ_HEAD(, intr_event) event_list = 112 TAILQ_HEAD_INITIALIZER(event_list); 113 static struct mtx event_lock; 114 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF); 115 116 static void intr_event_update(struct intr_event *ie); 117 static int intr_event_schedule_thread(struct intr_event *ie, struct trapframe *frame); 118 static struct intr_thread *ithread_create(const char *name); 119 static void ithread_destroy(struct intr_thread *ithread); 120 static void ithread_execute_handlers(struct proc *p, 121 struct intr_event *ie); 122 static void ithread_loop(void *); 123 static void ithread_update(struct intr_thread *ithd); 124 static void start_softintr(void *); 125 126 #ifdef HWPMC_HOOKS 127 #include <sys/pmckern.h> 128 PMC_SOFT_DEFINE( , , intr, all); 129 PMC_SOFT_DEFINE( , , intr, ithread); 130 PMC_SOFT_DEFINE( , , intr, filter); 131 PMC_SOFT_DEFINE( , , intr, stray); 132 PMC_SOFT_DEFINE( , , intr, schedule); 133 PMC_SOFT_DEFINE( , , intr, waiting); 134 #endif 135 136 /* Map an interrupt type to an ithread priority. */ 137 u_char 138 intr_priority(enum intr_type flags) 139 { 140 u_char pri; 141 142 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET | 143 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV); 144 switch (flags) { 145 case INTR_TYPE_TTY: 146 pri = PI_TTY; 147 break; 148 case INTR_TYPE_BIO: 149 pri = PI_DISK; 150 break; 151 case INTR_TYPE_NET: 152 pri = PI_NET; 153 break; 154 case INTR_TYPE_CAM: 155 pri = PI_DISK; 156 break; 157 case INTR_TYPE_AV: 158 pri = PI_AV; 159 break; 160 case INTR_TYPE_CLK: 161 pri = PI_REALTIME; 162 break; 163 case INTR_TYPE_MISC: 164 pri = PI_DULL; /* don't care */ 165 break; 166 default: 167 /* We didn't specify an interrupt level. */ 168 panic("intr_priority: no interrupt type in flags"); 169 } 170 171 return pri; 172 } 173 174 /* 175 * Update an ithread based on the associated intr_event. 176 */ 177 static void 178 ithread_update(struct intr_thread *ithd) 179 { 180 struct intr_event *ie; 181 struct thread *td; 182 u_char pri; 183 184 ie = ithd->it_event; 185 td = ithd->it_thread; 186 mtx_assert(&ie->ie_lock, MA_OWNED); 187 188 /* Determine the overall priority of this event. */ 189 if (CK_SLIST_EMPTY(&ie->ie_handlers)) 190 pri = PRI_MAX_ITHD; 191 else 192 pri = CK_SLIST_FIRST(&ie->ie_handlers)->ih_pri; 193 194 /* Update name and priority. */ 195 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name)); 196 #ifdef KTR 197 sched_clear_tdname(td); 198 #endif 199 thread_lock(td); 200 sched_prio(td, pri); 201 thread_unlock(td); 202 } 203 204 /* 205 * Regenerate the full name of an interrupt event and update its priority. 206 */ 207 static void 208 intr_event_update(struct intr_event *ie) 209 { 210 struct intr_handler *ih; 211 char *last; 212 int missed, space, flags; 213 214 /* Start off with no entropy and just the name of the event. */ 215 mtx_assert(&ie->ie_lock, MA_OWNED); 216 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 217 flags = 0; 218 missed = 0; 219 space = 1; 220 221 /* Run through all the handlers updating values. */ 222 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 223 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 < 224 sizeof(ie->ie_fullname)) { 225 strcat(ie->ie_fullname, " "); 226 strcat(ie->ie_fullname, ih->ih_name); 227 space = 0; 228 } else 229 missed++; 230 flags |= ih->ih_flags; 231 } 232 ie->ie_hflags = flags; 233 234 /* 235 * If there is only one handler and its name is too long, just copy in 236 * as much of the end of the name (includes the unit number) as will 237 * fit. Otherwise, we have multiple handlers and not all of the names 238 * will fit. Add +'s to indicate missing names. If we run out of room 239 * and still have +'s to add, change the last character from a + to a *. 240 */ 241 if (missed == 1 && space == 1) { 242 ih = CK_SLIST_FIRST(&ie->ie_handlers); 243 missed = strlen(ie->ie_fullname) + strlen(ih->ih_name) + 2 - 244 sizeof(ie->ie_fullname); 245 strcat(ie->ie_fullname, (missed == 0) ? " " : "-"); 246 strcat(ie->ie_fullname, &ih->ih_name[missed]); 247 missed = 0; 248 } 249 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2]; 250 while (missed-- > 0) { 251 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) { 252 if (*last == '+') { 253 *last = '*'; 254 break; 255 } else 256 *last = '+'; 257 } else if (space) { 258 strcat(ie->ie_fullname, " +"); 259 space = 0; 260 } else 261 strcat(ie->ie_fullname, "+"); 262 } 263 264 /* 265 * If this event has an ithread, update it's priority and 266 * name. 267 */ 268 if (ie->ie_thread != NULL) 269 ithread_update(ie->ie_thread); 270 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname); 271 } 272 273 int 274 intr_event_create(struct intr_event **event, void *source, int flags, int irq, 275 void (*pre_ithread)(void *), void (*post_ithread)(void *), 276 void (*post_filter)(void *), int (*assign_cpu)(void *, int), 277 const char *fmt, ...) 278 { 279 struct intr_event *ie; 280 va_list ap; 281 282 /* The only valid flag during creation is IE_SOFT. */ 283 if ((flags & ~IE_SOFT) != 0) 284 return (EINVAL); 285 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO); 286 ie->ie_source = source; 287 ie->ie_pre_ithread = pre_ithread; 288 ie->ie_post_ithread = post_ithread; 289 ie->ie_post_filter = post_filter; 290 ie->ie_assign_cpu = assign_cpu; 291 ie->ie_flags = flags; 292 ie->ie_irq = irq; 293 ie->ie_cpu = NOCPU; 294 CK_SLIST_INIT(&ie->ie_handlers); 295 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF); 296 297 va_start(ap, fmt); 298 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap); 299 va_end(ap); 300 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 301 mtx_lock(&event_lock); 302 TAILQ_INSERT_TAIL(&event_list, ie, ie_list); 303 mtx_unlock(&event_lock); 304 if (event != NULL) 305 *event = ie; 306 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name); 307 return (0); 308 } 309 310 /* 311 * Bind an interrupt event to the specified CPU. Note that not all 312 * platforms support binding an interrupt to a CPU. For those 313 * platforms this request will fail. Using a cpu id of NOCPU unbinds 314 * the interrupt event. 315 */ 316 static int 317 _intr_event_bind(struct intr_event *ie, int cpu, bool bindirq, bool bindithread) 318 { 319 lwpid_t id; 320 int error; 321 322 /* Need a CPU to bind to. */ 323 if (cpu != NOCPU && CPU_ABSENT(cpu)) 324 return (EINVAL); 325 326 if (ie->ie_assign_cpu == NULL) 327 return (EOPNOTSUPP); 328 329 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR); 330 if (error) 331 return (error); 332 333 /* 334 * If we have any ithreads try to set their mask first to verify 335 * permissions, etc. 336 */ 337 if (bindithread) { 338 mtx_lock(&ie->ie_lock); 339 if (ie->ie_thread != NULL) { 340 id = ie->ie_thread->it_thread->td_tid; 341 mtx_unlock(&ie->ie_lock); 342 error = cpuset_setithread(id, cpu); 343 if (error) 344 return (error); 345 } else 346 mtx_unlock(&ie->ie_lock); 347 } 348 if (bindirq) 349 error = ie->ie_assign_cpu(ie->ie_source, cpu); 350 if (error) { 351 if (bindithread) { 352 mtx_lock(&ie->ie_lock); 353 if (ie->ie_thread != NULL) { 354 cpu = ie->ie_cpu; 355 id = ie->ie_thread->it_thread->td_tid; 356 mtx_unlock(&ie->ie_lock); 357 (void)cpuset_setithread(id, cpu); 358 } else 359 mtx_unlock(&ie->ie_lock); 360 } 361 return (error); 362 } 363 364 if (bindirq) { 365 mtx_lock(&ie->ie_lock); 366 ie->ie_cpu = cpu; 367 mtx_unlock(&ie->ie_lock); 368 } 369 370 return (error); 371 } 372 373 /* 374 * Bind an interrupt event to the specified CPU. For supported platforms, any 375 * associated ithreads as well as the primary interrupt context will be bound 376 * to the specificed CPU. 377 */ 378 int 379 intr_event_bind(struct intr_event *ie, int cpu) 380 { 381 382 return (_intr_event_bind(ie, cpu, true, true)); 383 } 384 385 /* 386 * Bind an interrupt event to the specified CPU, but do not bind associated 387 * ithreads. 388 */ 389 int 390 intr_event_bind_irqonly(struct intr_event *ie, int cpu) 391 { 392 393 return (_intr_event_bind(ie, cpu, true, false)); 394 } 395 396 /* 397 * Bind an interrupt event's ithread to the specified CPU. 398 */ 399 int 400 intr_event_bind_ithread(struct intr_event *ie, int cpu) 401 { 402 403 return (_intr_event_bind(ie, cpu, false, true)); 404 } 405 406 /* 407 * Bind an interrupt event's ithread to the specified cpuset. 408 */ 409 int 410 intr_event_bind_ithread_cpuset(struct intr_event *ie, cpuset_t *cs) 411 { 412 lwpid_t id; 413 414 mtx_lock(&ie->ie_lock); 415 if (ie->ie_thread != NULL) { 416 id = ie->ie_thread->it_thread->td_tid; 417 mtx_unlock(&ie->ie_lock); 418 return (cpuset_setthread(id, cs)); 419 } else { 420 mtx_unlock(&ie->ie_lock); 421 } 422 return (ENODEV); 423 } 424 425 static struct intr_event * 426 intr_lookup(int irq) 427 { 428 struct intr_event *ie; 429 430 mtx_lock(&event_lock); 431 TAILQ_FOREACH(ie, &event_list, ie_list) 432 if (ie->ie_irq == irq && 433 (ie->ie_flags & IE_SOFT) == 0 && 434 CK_SLIST_FIRST(&ie->ie_handlers) != NULL) 435 break; 436 mtx_unlock(&event_lock); 437 return (ie); 438 } 439 440 int 441 intr_setaffinity(int irq, int mode, void *m) 442 { 443 struct intr_event *ie; 444 cpuset_t *mask; 445 int cpu, n; 446 447 mask = m; 448 cpu = NOCPU; 449 /* 450 * If we're setting all cpus we can unbind. Otherwise make sure 451 * only one cpu is in the set. 452 */ 453 if (CPU_CMP(cpuset_root, mask)) { 454 for (n = 0; n < CPU_SETSIZE; n++) { 455 if (!CPU_ISSET(n, mask)) 456 continue; 457 if (cpu != NOCPU) 458 return (EINVAL); 459 cpu = n; 460 } 461 } 462 ie = intr_lookup(irq); 463 if (ie == NULL) 464 return (ESRCH); 465 switch (mode) { 466 case CPU_WHICH_IRQ: 467 return (intr_event_bind(ie, cpu)); 468 case CPU_WHICH_INTRHANDLER: 469 return (intr_event_bind_irqonly(ie, cpu)); 470 case CPU_WHICH_ITHREAD: 471 return (intr_event_bind_ithread(ie, cpu)); 472 default: 473 return (EINVAL); 474 } 475 } 476 477 int 478 intr_getaffinity(int irq, int mode, void *m) 479 { 480 struct intr_event *ie; 481 struct thread *td; 482 struct proc *p; 483 cpuset_t *mask; 484 lwpid_t id; 485 int error; 486 487 mask = m; 488 ie = intr_lookup(irq); 489 if (ie == NULL) 490 return (ESRCH); 491 492 error = 0; 493 CPU_ZERO(mask); 494 switch (mode) { 495 case CPU_WHICH_IRQ: 496 case CPU_WHICH_INTRHANDLER: 497 mtx_lock(&ie->ie_lock); 498 if (ie->ie_cpu == NOCPU) 499 CPU_COPY(cpuset_root, mask); 500 else 501 CPU_SET(ie->ie_cpu, mask); 502 mtx_unlock(&ie->ie_lock); 503 break; 504 case CPU_WHICH_ITHREAD: 505 mtx_lock(&ie->ie_lock); 506 if (ie->ie_thread == NULL) { 507 mtx_unlock(&ie->ie_lock); 508 CPU_COPY(cpuset_root, mask); 509 } else { 510 id = ie->ie_thread->it_thread->td_tid; 511 mtx_unlock(&ie->ie_lock); 512 error = cpuset_which(CPU_WHICH_TID, id, &p, &td, NULL); 513 if (error != 0) 514 return (error); 515 CPU_COPY(&td->td_cpuset->cs_mask, mask); 516 PROC_UNLOCK(p); 517 } 518 default: 519 return (EINVAL); 520 } 521 return (0); 522 } 523 524 int 525 intr_event_destroy(struct intr_event *ie) 526 { 527 528 mtx_lock(&event_lock); 529 mtx_lock(&ie->ie_lock); 530 if (!CK_SLIST_EMPTY(&ie->ie_handlers)) { 531 mtx_unlock(&ie->ie_lock); 532 mtx_unlock(&event_lock); 533 return (EBUSY); 534 } 535 TAILQ_REMOVE(&event_list, ie, ie_list); 536 #ifndef notyet 537 if (ie->ie_thread != NULL) { 538 ithread_destroy(ie->ie_thread); 539 ie->ie_thread = NULL; 540 } 541 #endif 542 mtx_unlock(&ie->ie_lock); 543 mtx_unlock(&event_lock); 544 mtx_destroy(&ie->ie_lock); 545 free(ie, M_ITHREAD); 546 return (0); 547 } 548 549 static struct intr_thread * 550 ithread_create(const char *name) 551 { 552 struct intr_thread *ithd; 553 struct thread *td; 554 int error; 555 556 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 557 558 error = kproc_kthread_add(ithread_loop, ithd, &intrproc, 559 &td, RFSTOPPED | RFHIGHPID, 560 0, "intr", "%s", name); 561 if (error) 562 panic("kproc_create() failed with %d", error); 563 thread_lock(td); 564 sched_class(td, PRI_ITHD); 565 TD_SET_IWAIT(td); 566 thread_unlock(td); 567 td->td_pflags |= TDP_ITHREAD; 568 ithd->it_thread = td; 569 CTR2(KTR_INTR, "%s: created %s", __func__, name); 570 return (ithd); 571 } 572 573 static void 574 ithread_destroy(struct intr_thread *ithread) 575 { 576 struct thread *td; 577 578 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name); 579 td = ithread->it_thread; 580 thread_lock(td); 581 ithread->it_flags |= IT_DEAD; 582 if (TD_AWAITING_INTR(td)) { 583 TD_CLR_IWAIT(td); 584 sched_add(td, SRQ_INTR); 585 } else 586 thread_unlock(td); 587 } 588 589 int 590 intr_event_add_handler(struct intr_event *ie, const char *name, 591 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 592 enum intr_type flags, void **cookiep) 593 { 594 struct intr_handler *ih, *temp_ih; 595 struct intr_handler **prevptr; 596 struct intr_thread *it; 597 598 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 599 return (EINVAL); 600 601 /* Allocate and populate an interrupt handler structure. */ 602 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 603 ih->ih_filter = filter; 604 ih->ih_handler = handler; 605 ih->ih_argument = arg; 606 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 607 ih->ih_event = ie; 608 ih->ih_pri = pri; 609 if (flags & INTR_EXCL) 610 ih->ih_flags = IH_EXCLUSIVE; 611 if (flags & INTR_MPSAFE) 612 ih->ih_flags |= IH_MPSAFE; 613 if (flags & INTR_ENTROPY) 614 ih->ih_flags |= IH_ENTROPY; 615 if (flags & INTR_TYPE_NET) 616 ih->ih_flags |= IH_NET; 617 618 /* We can only have one exclusive handler in a event. */ 619 mtx_lock(&ie->ie_lock); 620 if (!CK_SLIST_EMPTY(&ie->ie_handlers)) { 621 if ((flags & INTR_EXCL) || 622 (CK_SLIST_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 623 mtx_unlock(&ie->ie_lock); 624 free(ih, M_ITHREAD); 625 return (EINVAL); 626 } 627 } 628 629 /* Create a thread if we need one. */ 630 while (ie->ie_thread == NULL && handler != NULL) { 631 if (ie->ie_flags & IE_ADDING_THREAD) 632 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 633 else { 634 ie->ie_flags |= IE_ADDING_THREAD; 635 mtx_unlock(&ie->ie_lock); 636 it = ithread_create("intr: newborn"); 637 mtx_lock(&ie->ie_lock); 638 ie->ie_flags &= ~IE_ADDING_THREAD; 639 ie->ie_thread = it; 640 it->it_event = ie; 641 ithread_update(it); 642 wakeup(ie); 643 } 644 } 645 646 /* Add the new handler to the event in priority order. */ 647 CK_SLIST_FOREACH_PREVPTR(temp_ih, prevptr, &ie->ie_handlers, ih_next) { 648 if (temp_ih->ih_pri > ih->ih_pri) 649 break; 650 } 651 CK_SLIST_INSERT_PREVPTR(prevptr, temp_ih, ih, ih_next); 652 653 intr_event_update(ie); 654 655 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 656 ie->ie_name); 657 mtx_unlock(&ie->ie_lock); 658 659 if (cookiep != NULL) 660 *cookiep = ih; 661 return (0); 662 } 663 664 /* 665 * Append a description preceded by a ':' to the name of the specified 666 * interrupt handler. 667 */ 668 int 669 intr_event_describe_handler(struct intr_event *ie, void *cookie, 670 const char *descr) 671 { 672 struct intr_handler *ih; 673 size_t space; 674 char *start; 675 676 mtx_lock(&ie->ie_lock); 677 #ifdef INVARIANTS 678 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 679 if (ih == cookie) 680 break; 681 } 682 if (ih == NULL) { 683 mtx_unlock(&ie->ie_lock); 684 panic("handler %p not found in interrupt event %p", cookie, ie); 685 } 686 #endif 687 ih = cookie; 688 689 /* 690 * Look for an existing description by checking for an 691 * existing ":". This assumes device names do not include 692 * colons. If one is found, prepare to insert the new 693 * description at that point. If one is not found, find the 694 * end of the name to use as the insertion point. 695 */ 696 start = strchr(ih->ih_name, ':'); 697 if (start == NULL) 698 start = strchr(ih->ih_name, 0); 699 700 /* 701 * See if there is enough remaining room in the string for the 702 * description + ":". The "- 1" leaves room for the trailing 703 * '\0'. The "+ 1" accounts for the colon. 704 */ 705 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1; 706 if (strlen(descr) + 1 > space) { 707 mtx_unlock(&ie->ie_lock); 708 return (ENOSPC); 709 } 710 711 /* Append a colon followed by the description. */ 712 *start = ':'; 713 strcpy(start + 1, descr); 714 intr_event_update(ie); 715 mtx_unlock(&ie->ie_lock); 716 return (0); 717 } 718 719 /* 720 * Return the ie_source field from the intr_event an intr_handler is 721 * associated with. 722 */ 723 void * 724 intr_handler_source(void *cookie) 725 { 726 struct intr_handler *ih; 727 struct intr_event *ie; 728 729 ih = (struct intr_handler *)cookie; 730 if (ih == NULL) 731 return (NULL); 732 ie = ih->ih_event; 733 KASSERT(ie != NULL, 734 ("interrupt handler \"%s\" has a NULL interrupt event", 735 ih->ih_name)); 736 return (ie->ie_source); 737 } 738 739 /* 740 * If intr_event_handle() is running in the ISR context at the time of the call, 741 * then wait for it to complete. 742 */ 743 static void 744 intr_event_barrier(struct intr_event *ie) 745 { 746 int phase; 747 748 mtx_assert(&ie->ie_lock, MA_OWNED); 749 phase = ie->ie_phase; 750 751 /* 752 * Switch phase to direct future interrupts to the other active counter. 753 * Make sure that any preceding stores are visible before the switch. 754 */ 755 KASSERT(ie->ie_active[!phase] == 0, ("idle phase has activity")); 756 atomic_store_rel_int(&ie->ie_phase, !phase); 757 758 /* 759 * This code cooperates with wait-free iteration of ie_handlers 760 * in intr_event_handle. 761 * Make sure that the removal and the phase update are not reordered 762 * with the active count check. 763 * Note that no combination of acquire and release fences can provide 764 * that guarantee as Store->Load sequences can always be reordered. 765 */ 766 atomic_thread_fence_seq_cst(); 767 768 /* 769 * Now wait on the inactive phase. 770 * The acquire fence is needed so that that all post-barrier accesses 771 * are after the check. 772 */ 773 while (ie->ie_active[phase] > 0) 774 cpu_spinwait(); 775 atomic_thread_fence_acq(); 776 } 777 778 static void 779 intr_handler_barrier(struct intr_handler *handler) 780 { 781 struct intr_event *ie; 782 783 ie = handler->ih_event; 784 mtx_assert(&ie->ie_lock, MA_OWNED); 785 KASSERT((handler->ih_flags & IH_DEAD) == 0, 786 ("update for a removed handler")); 787 788 if (ie->ie_thread == NULL) { 789 intr_event_barrier(ie); 790 return; 791 } 792 if ((handler->ih_flags & IH_CHANGED) == 0) { 793 handler->ih_flags |= IH_CHANGED; 794 intr_event_schedule_thread(ie, NULL); 795 } 796 while ((handler->ih_flags & IH_CHANGED) != 0) 797 msleep(handler, &ie->ie_lock, 0, "ih_barr", 0); 798 } 799 800 /* 801 * Sleep until an ithread finishes executing an interrupt handler. 802 * 803 * XXX Doesn't currently handle interrupt filters or fast interrupt 804 * handlers. This is intended for LinuxKPI drivers only. 805 * Do not use in BSD code. 806 */ 807 void 808 _intr_drain(int irq) 809 { 810 struct intr_event *ie; 811 struct intr_thread *ithd; 812 struct thread *td; 813 814 ie = intr_lookup(irq); 815 if (ie == NULL) 816 return; 817 if (ie->ie_thread == NULL) 818 return; 819 ithd = ie->ie_thread; 820 td = ithd->it_thread; 821 /* 822 * We set the flag and wait for it to be cleared to avoid 823 * long delays with potentially busy interrupt handlers 824 * were we to only sample TD_AWAITING_INTR() every tick. 825 */ 826 thread_lock(td); 827 if (!TD_AWAITING_INTR(td)) { 828 ithd->it_flags |= IT_WAIT; 829 while (ithd->it_flags & IT_WAIT) { 830 thread_unlock(td); 831 pause("idrain", 1); 832 thread_lock(td); 833 } 834 } 835 thread_unlock(td); 836 return; 837 } 838 839 int 840 intr_event_remove_handler(void *cookie) 841 { 842 struct intr_handler *handler = (struct intr_handler *)cookie; 843 struct intr_event *ie; 844 struct intr_handler *ih; 845 struct intr_handler **prevptr; 846 #ifdef notyet 847 int dead; 848 #endif 849 850 if (handler == NULL) 851 return (EINVAL); 852 ie = handler->ih_event; 853 KASSERT(ie != NULL, 854 ("interrupt handler \"%s\" has a NULL interrupt event", 855 handler->ih_name)); 856 857 mtx_lock(&ie->ie_lock); 858 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 859 ie->ie_name); 860 CK_SLIST_FOREACH_PREVPTR(ih, prevptr, &ie->ie_handlers, ih_next) { 861 if (ih == handler) 862 break; 863 } 864 if (ih == NULL) { 865 panic("interrupt handler \"%s\" not found in " 866 "interrupt event \"%s\"", handler->ih_name, ie->ie_name); 867 } 868 869 /* 870 * If there is no ithread, then directly remove the handler. Note that 871 * intr_event_handle() iterates ie_handlers in a lock-less fashion, so 872 * care needs to be taken to keep ie_handlers consistent and to free 873 * the removed handler only when ie_handlers is quiescent. 874 */ 875 if (ie->ie_thread == NULL) { 876 CK_SLIST_REMOVE_PREVPTR(prevptr, ih, ih_next); 877 intr_event_barrier(ie); 878 intr_event_update(ie); 879 mtx_unlock(&ie->ie_lock); 880 free(handler, M_ITHREAD); 881 return (0); 882 } 883 884 /* 885 * Let the interrupt thread do the job. 886 * The interrupt source is disabled when the interrupt thread is 887 * running, so it does not have to worry about interaction with 888 * intr_event_handle(). 889 */ 890 KASSERT((handler->ih_flags & IH_DEAD) == 0, 891 ("duplicate handle remove")); 892 handler->ih_flags |= IH_DEAD; 893 intr_event_schedule_thread(ie, NULL); 894 while (handler->ih_flags & IH_DEAD) 895 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 896 intr_event_update(ie); 897 898 #ifdef notyet 899 /* 900 * XXX: This could be bad in the case of ppbus(8). Also, I think 901 * this could lead to races of stale data when servicing an 902 * interrupt. 903 */ 904 dead = 1; 905 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 906 if (ih->ih_handler != NULL) { 907 dead = 0; 908 break; 909 } 910 } 911 if (dead) { 912 ithread_destroy(ie->ie_thread); 913 ie->ie_thread = NULL; 914 } 915 #endif 916 mtx_unlock(&ie->ie_lock); 917 free(handler, M_ITHREAD); 918 return (0); 919 } 920 921 int 922 intr_event_suspend_handler(void *cookie) 923 { 924 struct intr_handler *handler = (struct intr_handler *)cookie; 925 struct intr_event *ie; 926 927 if (handler == NULL) 928 return (EINVAL); 929 ie = handler->ih_event; 930 KASSERT(ie != NULL, 931 ("interrupt handler \"%s\" has a NULL interrupt event", 932 handler->ih_name)); 933 mtx_lock(&ie->ie_lock); 934 handler->ih_flags |= IH_SUSP; 935 intr_handler_barrier(handler); 936 mtx_unlock(&ie->ie_lock); 937 return (0); 938 } 939 940 int 941 intr_event_resume_handler(void *cookie) 942 { 943 struct intr_handler *handler = (struct intr_handler *)cookie; 944 struct intr_event *ie; 945 946 if (handler == NULL) 947 return (EINVAL); 948 ie = handler->ih_event; 949 KASSERT(ie != NULL, 950 ("interrupt handler \"%s\" has a NULL interrupt event", 951 handler->ih_name)); 952 953 /* 954 * intr_handler_barrier() acts not only as a barrier, 955 * it also allows to check for any pending interrupts. 956 */ 957 mtx_lock(&ie->ie_lock); 958 handler->ih_flags &= ~IH_SUSP; 959 intr_handler_barrier(handler); 960 mtx_unlock(&ie->ie_lock); 961 return (0); 962 } 963 964 static int 965 intr_event_schedule_thread(struct intr_event *ie, struct trapframe *frame) 966 { 967 struct intr_entropy entropy; 968 struct intr_thread *it; 969 struct thread *td; 970 struct thread *ctd; 971 972 /* 973 * If no ithread or no handlers, then we have a stray interrupt. 974 */ 975 if (ie == NULL || CK_SLIST_EMPTY(&ie->ie_handlers) || 976 ie->ie_thread == NULL) 977 return (EINVAL); 978 979 ctd = curthread; 980 it = ie->ie_thread; 981 td = it->it_thread; 982 983 /* 984 * If any of the handlers for this ithread claim to be good 985 * sources of entropy, then gather some. 986 */ 987 if (ie->ie_hflags & IH_ENTROPY) { 988 entropy.event = (uintptr_t)ie; 989 entropy.td = ctd; 990 random_harvest_queue(&entropy, sizeof(entropy), RANDOM_INTERRUPT); 991 } 992 993 KASSERT(td->td_proc != NULL, ("ithread %s has no process", ie->ie_name)); 994 995 /* 996 * Set it_need to tell the thread to keep running if it is already 997 * running. Then, lock the thread and see if we actually need to 998 * put it on the runqueue. 999 * 1000 * Use store_rel to arrange that the store to ih_need in 1001 * swi_sched() is before the store to it_need and prepare for 1002 * transfer of this order to loads in the ithread. 1003 */ 1004 atomic_store_rel_int(&it->it_need, 1); 1005 thread_lock(td); 1006 if (TD_AWAITING_INTR(td)) { 1007 #ifdef HWPMC_HOOKS 1008 atomic_set_int(&it->it_waiting, 0); 1009 if (frame != NULL) 1010 PMC_SOFT_CALL_TF( , , intr, schedule, frame); 1011 else 1012 PMC_SOFT_CALL( , , intr, schedule); 1013 #endif 1014 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, td->td_proc->p_pid, 1015 td->td_name); 1016 TD_CLR_IWAIT(td); 1017 sched_add(td, SRQ_INTR); 1018 } else { 1019 #ifdef HWPMC_HOOKS 1020 atomic_add_int(&it->it_waiting, 1); 1021 1022 if (atomic_load_int(&it->it_waiting) >= intr_hwpmc_waiting_report_threshold) { 1023 if (frame != NULL) 1024 PMC_SOFT_CALL_TF( , , intr, waiting, frame); 1025 else 1026 PMC_SOFT_CALL( , , intr, waiting); 1027 } 1028 #endif 1029 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 1030 __func__, td->td_proc->p_pid, td->td_name, it->it_need, TD_GET_STATE(td)); 1031 thread_unlock(td); 1032 } 1033 1034 return (0); 1035 } 1036 1037 /* 1038 * Allow interrupt event binding for software interrupt handlers -- a no-op, 1039 * since interrupts are generated in software rather than being directed by 1040 * a PIC. 1041 */ 1042 static int 1043 swi_assign_cpu(void *arg, int cpu) 1044 { 1045 1046 return (0); 1047 } 1048 1049 /* 1050 * Add a software interrupt handler to a specified event. If a given event 1051 * is not specified, then a new event is created. 1052 */ 1053 int 1054 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler, 1055 void *arg, int pri, enum intr_type flags, void **cookiep) 1056 { 1057 struct intr_event *ie; 1058 int error = 0; 1059 1060 if (flags & INTR_ENTROPY) 1061 return (EINVAL); 1062 1063 ie = (eventp != NULL) ? *eventp : NULL; 1064 1065 if (ie != NULL) { 1066 if (!(ie->ie_flags & IE_SOFT)) 1067 return (EINVAL); 1068 } else { 1069 error = intr_event_create(&ie, NULL, IE_SOFT, 0, 1070 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri); 1071 if (error) 1072 return (error); 1073 if (eventp != NULL) 1074 *eventp = ie; 1075 } 1076 if (handler != NULL) { 1077 error = intr_event_add_handler(ie, name, NULL, handler, arg, 1078 PI_SWI(pri), flags, cookiep); 1079 } 1080 return (error); 1081 } 1082 1083 /* 1084 * Schedule a software interrupt thread. 1085 */ 1086 void 1087 swi_sched(void *cookie, int flags) 1088 { 1089 struct intr_handler *ih = (struct intr_handler *)cookie; 1090 struct intr_event *ie = ih->ih_event; 1091 struct intr_entropy entropy; 1092 int error __unused; 1093 1094 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name, 1095 ih->ih_need); 1096 1097 if ((flags & SWI_FROMNMI) == 0) { 1098 entropy.event = (uintptr_t)ih; 1099 entropy.td = curthread; 1100 random_harvest_queue(&entropy, sizeof(entropy), RANDOM_SWI); 1101 } 1102 1103 /* 1104 * Set ih_need for this handler so that if the ithread is already 1105 * running it will execute this handler on the next pass. Otherwise, 1106 * it will execute it the next time it runs. 1107 */ 1108 ih->ih_need = 1; 1109 1110 if (flags & SWI_DELAY) 1111 return; 1112 1113 if (flags & SWI_FROMNMI) { 1114 #if defined(SMP) && (defined(__i386__) || defined(__amd64__)) 1115 KASSERT(ie == clk_intr_event, 1116 ("SWI_FROMNMI used not with clk_intr_event")); 1117 ipi_self_from_nmi(IPI_SWI); 1118 #endif 1119 } else { 1120 VM_CNT_INC(v_soft); 1121 error = intr_event_schedule_thread(ie, NULL); 1122 KASSERT(error == 0, ("stray software interrupt")); 1123 } 1124 } 1125 1126 /* 1127 * Remove a software interrupt handler. Currently this code does not 1128 * remove the associated interrupt event if it becomes empty. Calling code 1129 * may do so manually via intr_event_destroy(), but that's not really 1130 * an optimal interface. 1131 */ 1132 int 1133 swi_remove(void *cookie) 1134 { 1135 1136 return (intr_event_remove_handler(cookie)); 1137 } 1138 1139 static void 1140 intr_event_execute_handlers(struct proc *p, struct intr_event *ie) 1141 { 1142 struct intr_handler *ih, *ihn, *ihp; 1143 1144 ihp = NULL; 1145 CK_SLIST_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) { 1146 /* 1147 * If this handler is marked for death, remove it from 1148 * the list of handlers and wake up the sleeper. 1149 */ 1150 if (ih->ih_flags & IH_DEAD) { 1151 mtx_lock(&ie->ie_lock); 1152 if (ihp == NULL) 1153 CK_SLIST_REMOVE_HEAD(&ie->ie_handlers, ih_next); 1154 else 1155 CK_SLIST_REMOVE_AFTER(ihp, ih_next); 1156 ih->ih_flags &= ~IH_DEAD; 1157 wakeup(ih); 1158 mtx_unlock(&ie->ie_lock); 1159 continue; 1160 } 1161 1162 /* 1163 * Now that we know that the current element won't be removed 1164 * update the previous element. 1165 */ 1166 ihp = ih; 1167 1168 if ((ih->ih_flags & IH_CHANGED) != 0) { 1169 mtx_lock(&ie->ie_lock); 1170 ih->ih_flags &= ~IH_CHANGED; 1171 wakeup(ih); 1172 mtx_unlock(&ie->ie_lock); 1173 } 1174 1175 /* Skip filter only handlers */ 1176 if (ih->ih_handler == NULL) 1177 continue; 1178 1179 /* Skip suspended handlers */ 1180 if ((ih->ih_flags & IH_SUSP) != 0) 1181 continue; 1182 1183 /* 1184 * For software interrupt threads, we only execute 1185 * handlers that have their need flag set. Hardware 1186 * interrupt threads always invoke all of their handlers. 1187 * 1188 * ih_need can only be 0 or 1. Failed cmpset below 1189 * means that there is no request to execute handlers, 1190 * so a retry of the cmpset is not needed. 1191 */ 1192 if ((ie->ie_flags & IE_SOFT) != 0 && 1193 atomic_cmpset_int(&ih->ih_need, 1, 0) == 0) 1194 continue; 1195 1196 /* Execute this handler. */ 1197 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1198 __func__, p->p_pid, (void *)ih->ih_handler, 1199 ih->ih_argument, ih->ih_name, ih->ih_flags); 1200 1201 if (!(ih->ih_flags & IH_MPSAFE)) 1202 mtx_lock(&Giant); 1203 ih->ih_handler(ih->ih_argument); 1204 if (!(ih->ih_flags & IH_MPSAFE)) 1205 mtx_unlock(&Giant); 1206 } 1207 } 1208 1209 static void 1210 ithread_execute_handlers(struct proc *p, struct intr_event *ie) 1211 { 1212 1213 /* Interrupt handlers should not sleep. */ 1214 if (!(ie->ie_flags & IE_SOFT)) 1215 THREAD_NO_SLEEPING(); 1216 intr_event_execute_handlers(p, ie); 1217 if (!(ie->ie_flags & IE_SOFT)) 1218 THREAD_SLEEPING_OK(); 1219 1220 /* 1221 * Interrupt storm handling: 1222 * 1223 * If this interrupt source is currently storming, then throttle 1224 * it to only fire the handler once per clock tick. 1225 * 1226 * If this interrupt source is not currently storming, but the 1227 * number of back to back interrupts exceeds the storm threshold, 1228 * then enter storming mode. 1229 */ 1230 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold && 1231 !(ie->ie_flags & IE_SOFT)) { 1232 /* Report the message only once every second. */ 1233 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) { 1234 printf( 1235 "interrupt storm detected on \"%s\"; throttling interrupt source\n", 1236 ie->ie_name); 1237 } 1238 pause("istorm", 1); 1239 } else 1240 ie->ie_count++; 1241 1242 /* 1243 * Now that all the handlers have had a chance to run, reenable 1244 * the interrupt source. 1245 */ 1246 if (ie->ie_post_ithread != NULL) 1247 ie->ie_post_ithread(ie->ie_source); 1248 } 1249 1250 /* 1251 * This is the main code for interrupt threads. 1252 */ 1253 static void 1254 ithread_loop(void *arg) 1255 { 1256 struct epoch_tracker et; 1257 struct intr_thread *ithd; 1258 struct intr_event *ie; 1259 struct thread *td; 1260 struct proc *p; 1261 int wake, epoch_count; 1262 bool needs_epoch; 1263 1264 td = curthread; 1265 p = td->td_proc; 1266 ithd = (struct intr_thread *)arg; 1267 KASSERT(ithd->it_thread == td, 1268 ("%s: ithread and proc linkage out of sync", __func__)); 1269 ie = ithd->it_event; 1270 ie->ie_count = 0; 1271 wake = 0; 1272 1273 /* 1274 * As long as we have interrupts outstanding, go through the 1275 * list of handlers, giving each one a go at it. 1276 */ 1277 for (;;) { 1278 /* 1279 * If we are an orphaned thread, then just die. 1280 */ 1281 if (ithd->it_flags & IT_DEAD) { 1282 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1283 p->p_pid, td->td_name); 1284 free(ithd, M_ITHREAD); 1285 kthread_exit(); 1286 } 1287 1288 /* 1289 * Service interrupts. If another interrupt arrives while 1290 * we are running, it will set it_need to note that we 1291 * should make another pass. 1292 * 1293 * The load_acq part of the following cmpset ensures 1294 * that the load of ih_need in ithread_execute_handlers() 1295 * is ordered after the load of it_need here. 1296 */ 1297 needs_epoch = 1298 (atomic_load_int(&ie->ie_hflags) & IH_NET) != 0; 1299 if (needs_epoch) { 1300 epoch_count = 0; 1301 NET_EPOCH_ENTER(et); 1302 } 1303 while (atomic_cmpset_acq_int(&ithd->it_need, 1, 0) != 0) { 1304 ithread_execute_handlers(p, ie); 1305 if (needs_epoch && 1306 ++epoch_count >= intr_epoch_batch) { 1307 NET_EPOCH_EXIT(et); 1308 epoch_count = 0; 1309 NET_EPOCH_ENTER(et); 1310 } 1311 } 1312 if (needs_epoch) 1313 NET_EPOCH_EXIT(et); 1314 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1315 mtx_assert(&Giant, MA_NOTOWNED); 1316 1317 /* 1318 * Processed all our interrupts. Now get the sched 1319 * lock. This may take a while and it_need may get 1320 * set again, so we have to check it again. 1321 */ 1322 thread_lock(td); 1323 if (atomic_load_acq_int(&ithd->it_need) == 0 && 1324 (ithd->it_flags & (IT_DEAD | IT_WAIT)) == 0) { 1325 TD_SET_IWAIT(td); 1326 ie->ie_count = 0; 1327 mi_switch(SW_VOL | SWT_IWAIT); 1328 } else { 1329 if (ithd->it_flags & IT_WAIT) { 1330 wake = 1; 1331 ithd->it_flags &= ~IT_WAIT; 1332 } 1333 thread_unlock(td); 1334 } 1335 if (wake) { 1336 wakeup(ithd); 1337 wake = 0; 1338 } 1339 } 1340 } 1341 1342 /* 1343 * Main interrupt handling body. 1344 * 1345 * Input: 1346 * o ie: the event connected to this interrupt. 1347 * o frame: some archs (i.e. i386) pass a frame to some. 1348 * handlers as their main argument. 1349 * Return value: 1350 * o 0: everything ok. 1351 * o EINVAL: stray interrupt. 1352 */ 1353 int 1354 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1355 { 1356 struct intr_handler *ih; 1357 struct trapframe *oldframe; 1358 struct thread *td; 1359 int phase; 1360 int ret; 1361 bool filter, thread; 1362 1363 td = curthread; 1364 1365 #ifdef KSTACK_USAGE_PROF 1366 intr_prof_stack_use(td, frame); 1367 #endif 1368 1369 /* An interrupt with no event or handlers is a stray interrupt. */ 1370 if (ie == NULL || CK_SLIST_EMPTY(&ie->ie_handlers)) 1371 return (EINVAL); 1372 1373 /* 1374 * Execute fast interrupt handlers directly. 1375 * To support clock handlers, if a handler registers 1376 * with a NULL argument, then we pass it a pointer to 1377 * a trapframe as its argument. 1378 */ 1379 td->td_intr_nesting_level++; 1380 filter = false; 1381 thread = false; 1382 ret = 0; 1383 critical_enter(); 1384 oldframe = td->td_intr_frame; 1385 td->td_intr_frame = frame; 1386 1387 phase = ie->ie_phase; 1388 atomic_add_int(&ie->ie_active[phase], 1); 1389 1390 /* 1391 * This fence is required to ensure that no later loads are 1392 * re-ordered before the ie_active store. 1393 */ 1394 atomic_thread_fence_seq_cst(); 1395 1396 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { 1397 if ((ih->ih_flags & IH_SUSP) != 0) 1398 continue; 1399 if ((ie->ie_flags & IE_SOFT) != 0 && ih->ih_need == 0) 1400 continue; 1401 if (ih->ih_filter == NULL) { 1402 thread = true; 1403 continue; 1404 } 1405 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__, 1406 ih->ih_filter, ih->ih_argument == NULL ? frame : 1407 ih->ih_argument, ih->ih_name); 1408 if (ih->ih_argument == NULL) 1409 ret = ih->ih_filter(frame); 1410 else 1411 ret = ih->ih_filter(ih->ih_argument); 1412 #ifdef HWPMC_HOOKS 1413 PMC_SOFT_CALL_TF( , , intr, all, frame); 1414 #endif 1415 KASSERT(ret == FILTER_STRAY || 1416 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1417 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1418 ("%s: incorrect return value %#x from %s", __func__, ret, 1419 ih->ih_name)); 1420 filter = filter || ret == FILTER_HANDLED; 1421 #ifdef HWPMC_HOOKS 1422 if (ret & FILTER_SCHEDULE_THREAD) 1423 PMC_SOFT_CALL_TF( , , intr, ithread, frame); 1424 else if (ret & FILTER_HANDLED) 1425 PMC_SOFT_CALL_TF( , , intr, filter, frame); 1426 else if (ret == FILTER_STRAY) 1427 PMC_SOFT_CALL_TF( , , intr, stray, frame); 1428 #endif 1429 1430 /* 1431 * Wrapper handler special handling: 1432 * 1433 * in some particular cases (like pccard and pccbb), 1434 * the _real_ device handler is wrapped in a couple of 1435 * functions - a filter wrapper and an ithread wrapper. 1436 * In this case (and just in this case), the filter wrapper 1437 * could ask the system to schedule the ithread and mask 1438 * the interrupt source if the wrapped handler is composed 1439 * of just an ithread handler. 1440 * 1441 * TODO: write a generic wrapper to avoid people rolling 1442 * their own. 1443 */ 1444 if (!thread) { 1445 if (ret == FILTER_SCHEDULE_THREAD) 1446 thread = true; 1447 } 1448 } 1449 atomic_add_rel_int(&ie->ie_active[phase], -1); 1450 1451 td->td_intr_frame = oldframe; 1452 1453 if (thread) { 1454 if (ie->ie_pre_ithread != NULL) 1455 ie->ie_pre_ithread(ie->ie_source); 1456 } else { 1457 if (ie->ie_post_filter != NULL) 1458 ie->ie_post_filter(ie->ie_source); 1459 } 1460 1461 /* Schedule the ithread if needed. */ 1462 if (thread) { 1463 int error __unused; 1464 1465 error = intr_event_schedule_thread(ie, frame); 1466 KASSERT(error == 0, ("bad stray interrupt")); 1467 } 1468 critical_exit(); 1469 td->td_intr_nesting_level--; 1470 #ifdef notyet 1471 /* The interrupt is not aknowledged by any filter and has no ithread. */ 1472 if (!thread && !filter) 1473 return (EINVAL); 1474 #endif 1475 return (0); 1476 } 1477 1478 #ifdef DDB 1479 /* 1480 * Dump details about an interrupt handler 1481 */ 1482 static void 1483 db_dump_intrhand(struct intr_handler *ih) 1484 { 1485 int comma; 1486 1487 db_printf("\t%-10s ", ih->ih_name); 1488 switch (ih->ih_pri) { 1489 case PI_REALTIME: 1490 db_printf("CLK "); 1491 break; 1492 case PI_AV: 1493 db_printf("AV "); 1494 break; 1495 case PI_TTY: 1496 db_printf("TTY "); 1497 break; 1498 case PI_NET: 1499 db_printf("NET "); 1500 break; 1501 case PI_DISK: 1502 db_printf("DISK"); 1503 break; 1504 case PI_DULL: 1505 db_printf("DULL"); 1506 break; 1507 default: 1508 if (ih->ih_pri >= PI_SOFT) 1509 db_printf("SWI "); 1510 else 1511 db_printf("%4u", ih->ih_pri); 1512 break; 1513 } 1514 db_printf(" "); 1515 if (ih->ih_filter != NULL) { 1516 db_printf("[F]"); 1517 db_printsym((uintptr_t)ih->ih_filter, DB_STGY_PROC); 1518 } 1519 if (ih->ih_handler != NULL) { 1520 if (ih->ih_filter != NULL) 1521 db_printf(","); 1522 db_printf("[H]"); 1523 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC); 1524 } 1525 db_printf("(%p)", ih->ih_argument); 1526 if (ih->ih_need || 1527 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD | 1528 IH_MPSAFE)) != 0) { 1529 db_printf(" {"); 1530 comma = 0; 1531 if (ih->ih_flags & IH_EXCLUSIVE) { 1532 if (comma) 1533 db_printf(", "); 1534 db_printf("EXCL"); 1535 comma = 1; 1536 } 1537 if (ih->ih_flags & IH_ENTROPY) { 1538 if (comma) 1539 db_printf(", "); 1540 db_printf("ENTROPY"); 1541 comma = 1; 1542 } 1543 if (ih->ih_flags & IH_DEAD) { 1544 if (comma) 1545 db_printf(", "); 1546 db_printf("DEAD"); 1547 comma = 1; 1548 } 1549 if (ih->ih_flags & IH_MPSAFE) { 1550 if (comma) 1551 db_printf(", "); 1552 db_printf("MPSAFE"); 1553 comma = 1; 1554 } 1555 if (ih->ih_need) { 1556 if (comma) 1557 db_printf(", "); 1558 db_printf("NEED"); 1559 } 1560 db_printf("}"); 1561 } 1562 db_printf("\n"); 1563 } 1564 1565 /* 1566 * Dump details about a event. 1567 */ 1568 void 1569 db_dump_intr_event(struct intr_event *ie, int handlers) 1570 { 1571 struct intr_handler *ih; 1572 struct intr_thread *it; 1573 int comma; 1574 1575 db_printf("%s ", ie->ie_fullname); 1576 it = ie->ie_thread; 1577 if (it != NULL) 1578 db_printf("(pid %d)", it->it_thread->td_proc->p_pid); 1579 else 1580 db_printf("(no thread)"); 1581 if ((ie->ie_flags & (IE_SOFT | IE_ADDING_THREAD)) != 0 || 1582 (it != NULL && it->it_need)) { 1583 db_printf(" {"); 1584 comma = 0; 1585 if (ie->ie_flags & IE_SOFT) { 1586 db_printf("SOFT"); 1587 comma = 1; 1588 } 1589 if (ie->ie_flags & IE_ADDING_THREAD) { 1590 if (comma) 1591 db_printf(", "); 1592 db_printf("ADDING_THREAD"); 1593 comma = 1; 1594 } 1595 if (it != NULL && it->it_need) { 1596 if (comma) 1597 db_printf(", "); 1598 db_printf("NEED"); 1599 } 1600 db_printf("}"); 1601 } 1602 db_printf("\n"); 1603 1604 if (handlers) 1605 CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) 1606 db_dump_intrhand(ih); 1607 } 1608 1609 /* 1610 * Dump data about interrupt handlers 1611 */ 1612 DB_SHOW_COMMAND(intr, db_show_intr) 1613 { 1614 struct intr_event *ie; 1615 int all, verbose; 1616 1617 verbose = strchr(modif, 'v') != NULL; 1618 all = strchr(modif, 'a') != NULL; 1619 TAILQ_FOREACH(ie, &event_list, ie_list) { 1620 if (!all && CK_SLIST_EMPTY(&ie->ie_handlers)) 1621 continue; 1622 db_dump_intr_event(ie, verbose); 1623 if (db_pager_quit) 1624 break; 1625 } 1626 } 1627 #endif /* DDB */ 1628 1629 /* 1630 * Start standard software interrupt threads 1631 */ 1632 static void 1633 start_softintr(void *dummy) 1634 { 1635 1636 if (swi_add(&clk_intr_event, "clk", NULL, NULL, SWI_CLOCK, 1637 INTR_MPSAFE, NULL)) 1638 panic("died while creating clk swi ithread"); 1639 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih)) 1640 panic("died while creating vm swi ithread"); 1641 } 1642 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, 1643 NULL); 1644 1645 /* 1646 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. 1647 * The data for this machine dependent, and the declarations are in machine 1648 * dependent code. The layout of intrnames and intrcnt however is machine 1649 * independent. 1650 * 1651 * We do not know the length of intrcnt and intrnames at compile time, so 1652 * calculate things at run time. 1653 */ 1654 static int 1655 sysctl_intrnames(SYSCTL_HANDLER_ARGS) 1656 { 1657 return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req)); 1658 } 1659 1660 SYSCTL_PROC(_hw, OID_AUTO, intrnames, 1661 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 1662 sysctl_intrnames, "", 1663 "Interrupt Names"); 1664 1665 static int 1666 sysctl_intrcnt(SYSCTL_HANDLER_ARGS) 1667 { 1668 #ifdef SCTL_MASK32 1669 uint32_t *intrcnt32; 1670 unsigned i; 1671 int error; 1672 1673 if (req->flags & SCTL_MASK32) { 1674 if (!req->oldptr) 1675 return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req)); 1676 intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT); 1677 if (intrcnt32 == NULL) 1678 return (ENOMEM); 1679 for (i = 0; i < sintrcnt / sizeof (u_long); i++) 1680 intrcnt32[i] = intrcnt[i]; 1681 error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req); 1682 free(intrcnt32, M_TEMP); 1683 return (error); 1684 } 1685 #endif 1686 return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req)); 1687 } 1688 1689 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, 1690 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, 1691 sysctl_intrcnt, "", 1692 "Interrupt Counts"); 1693 1694 #ifdef DDB 1695 /* 1696 * DDB command to dump the interrupt statistics. 1697 */ 1698 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt) 1699 { 1700 u_long *i; 1701 char *cp; 1702 u_int j; 1703 1704 cp = intrnames; 1705 j = 0; 1706 for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit; 1707 i++, j++) { 1708 if (*cp == '\0') 1709 break; 1710 if (*i != 0) 1711 db_printf("%s\t%lu\n", cp, *i); 1712 cp += strlen(cp) + 1; 1713 } 1714 } 1715 #endif 1716