Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_intr.c
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1 /*- 2 * Copyright (c) 1997, Stefan Esser <se@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD: releng/11.1/sys/kern/kern_intr.c 285751 2015-07-21 14:39:34Z kib $"); 29 30 #include "opt_ddb.h" 31 #include "opt_kstack_usage_prof.h" 32 33 #include <sys/param.h> 34 #include <sys/bus.h> 35 #include <sys/conf.h> 36 #include <sys/cpuset.h> 37 #include <sys/rtprio.h> 38 #include <sys/systm.h> 39 #include <sys/interrupt.h> 40 #include <sys/kernel.h> 41 #include <sys/kthread.h> 42 #include <sys/ktr.h> 43 #include <sys/limits.h> 44 #include <sys/lock.h> 45 #include <sys/malloc.h> 46 #include <sys/mutex.h> 47 #include <sys/priv.h> 48 #include <sys/proc.h> 49 #include <sys/random.h> 50 #include <sys/resourcevar.h> 51 #include <sys/sched.h> 52 #include <sys/smp.h> 53 #include <sys/sysctl.h> 54 #include <sys/syslog.h> 55 #include <sys/unistd.h> 56 #include <sys/vmmeter.h> 57 #include <machine/atomic.h> 58 #include <machine/cpu.h> 59 #include <machine/md_var.h> 60 #include <machine/stdarg.h> 61 #ifdef DDB 62 #include <ddb/ddb.h> 63 #include <ddb/db_sym.h> 64 #endif 65 66 /* 67 * Describe an interrupt thread. There is one of these per interrupt event. 68 */ 69 struct intr_thread { 70 struct intr_event *it_event; 71 struct thread *it_thread; /* Kernel thread. */ 72 int it_flags; /* (j) IT_* flags. */ 73 int it_need; /* Needs service. */ 74 }; 75 76 /* Interrupt thread flags kept in it_flags */ 77 #define IT_DEAD 0x000001 /* Thread is waiting to exit. */ 78 #define IT_WAIT 0x000002 /* Thread is waiting for completion. */ 79 80 struct intr_entropy { 81 struct thread *td; 82 uintptr_t event; 83 }; 84 85 struct intr_event *clk_intr_event; 86 struct intr_event *tty_intr_event; 87 void *vm_ih; 88 struct proc *intrproc; 89 90 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads"); 91 92 static int intr_storm_threshold = 1000; 93 SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RWTUN, 94 &intr_storm_threshold, 0, 95 "Number of consecutive interrupts before storm protection is enabled"); 96 static TAILQ_HEAD(, intr_event) event_list = 97 TAILQ_HEAD_INITIALIZER(event_list); 98 static struct mtx event_lock; 99 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF); 100 101 static void intr_event_update(struct intr_event *ie); 102 #ifdef INTR_FILTER 103 static int intr_event_schedule_thread(struct intr_event *ie, 104 struct intr_thread *ithd); 105 static int intr_filter_loop(struct intr_event *ie, 106 struct trapframe *frame, struct intr_thread **ithd); 107 static struct intr_thread *ithread_create(const char *name, 108 struct intr_handler *ih); 109 #else 110 static int intr_event_schedule_thread(struct intr_event *ie); 111 static struct intr_thread *ithread_create(const char *name); 112 #endif 113 static void ithread_destroy(struct intr_thread *ithread); 114 static void ithread_execute_handlers(struct proc *p, 115 struct intr_event *ie); 116 #ifdef INTR_FILTER 117 static void priv_ithread_execute_handler(struct proc *p, 118 struct intr_handler *ih); 119 #endif 120 static void ithread_loop(void *); 121 static void ithread_update(struct intr_thread *ithd); 122 static void start_softintr(void *); 123 124 /* Map an interrupt type to an ithread priority. */ 125 u_char 126 intr_priority(enum intr_type flags) 127 { 128 u_char pri; 129 130 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET | 131 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV); 132 switch (flags) { 133 case INTR_TYPE_TTY: 134 pri = PI_TTY; 135 break; 136 case INTR_TYPE_BIO: 137 pri = PI_DISK; 138 break; 139 case INTR_TYPE_NET: 140 pri = PI_NET; 141 break; 142 case INTR_TYPE_CAM: 143 pri = PI_DISK; 144 break; 145 case INTR_TYPE_AV: 146 pri = PI_AV; 147 break; 148 case INTR_TYPE_CLK: 149 pri = PI_REALTIME; 150 break; 151 case INTR_TYPE_MISC: 152 pri = PI_DULL; /* don't care */ 153 break; 154 default: 155 /* We didn't specify an interrupt level. */ 156 panic("intr_priority: no interrupt type in flags"); 157 } 158 159 return pri; 160 } 161 162 /* 163 * Update an ithread based on the associated intr_event. 164 */ 165 static void 166 ithread_update(struct intr_thread *ithd) 167 { 168 struct intr_event *ie; 169 struct thread *td; 170 u_char pri; 171 172 ie = ithd->it_event; 173 td = ithd->it_thread; 174 175 /* Determine the overall priority of this event. */ 176 if (TAILQ_EMPTY(&ie->ie_handlers)) 177 pri = PRI_MAX_ITHD; 178 else 179 pri = TAILQ_FIRST(&ie->ie_handlers)->ih_pri; 180 181 /* Update name and priority. */ 182 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name)); 183 #ifdef KTR 184 sched_clear_tdname(td); 185 #endif 186 thread_lock(td); 187 sched_prio(td, pri); 188 thread_unlock(td); 189 } 190 191 /* 192 * Regenerate the full name of an interrupt event and update its priority. 193 */ 194 static void 195 intr_event_update(struct intr_event *ie) 196 { 197 struct intr_handler *ih; 198 char *last; 199 int missed, space; 200 201 /* Start off with no entropy and just the name of the event. */ 202 mtx_assert(&ie->ie_lock, MA_OWNED); 203 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 204 ie->ie_flags &= ~IE_ENTROPY; 205 missed = 0; 206 space = 1; 207 208 /* Run through all the handlers updating values. */ 209 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 210 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 < 211 sizeof(ie->ie_fullname)) { 212 strcat(ie->ie_fullname, " "); 213 strcat(ie->ie_fullname, ih->ih_name); 214 space = 0; 215 } else 216 missed++; 217 if (ih->ih_flags & IH_ENTROPY) 218 ie->ie_flags |= IE_ENTROPY; 219 } 220 221 /* 222 * If the handler names were too long, add +'s to indicate missing 223 * names. If we run out of room and still have +'s to add, change 224 * the last character from a + to a *. 225 */ 226 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2]; 227 while (missed-- > 0) { 228 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) { 229 if (*last == '+') { 230 *last = '*'; 231 break; 232 } else 233 *last = '+'; 234 } else if (space) { 235 strcat(ie->ie_fullname, " +"); 236 space = 0; 237 } else 238 strcat(ie->ie_fullname, "+"); 239 } 240 241 /* 242 * If this event has an ithread, update it's priority and 243 * name. 244 */ 245 if (ie->ie_thread != NULL) 246 ithread_update(ie->ie_thread); 247 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname); 248 } 249 250 int 251 intr_event_create(struct intr_event **event, void *source, int flags, int irq, 252 void (*pre_ithread)(void *), void (*post_ithread)(void *), 253 void (*post_filter)(void *), int (*assign_cpu)(void *, int), 254 const char *fmt, ...) 255 { 256 struct intr_event *ie; 257 va_list ap; 258 259 /* The only valid flag during creation is IE_SOFT. */ 260 if ((flags & ~IE_SOFT) != 0) 261 return (EINVAL); 262 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO); 263 ie->ie_source = source; 264 ie->ie_pre_ithread = pre_ithread; 265 ie->ie_post_ithread = post_ithread; 266 ie->ie_post_filter = post_filter; 267 ie->ie_assign_cpu = assign_cpu; 268 ie->ie_flags = flags; 269 ie->ie_irq = irq; 270 ie->ie_cpu = NOCPU; 271 TAILQ_INIT(&ie->ie_handlers); 272 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF); 273 274 va_start(ap, fmt); 275 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap); 276 va_end(ap); 277 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 278 mtx_lock(&event_lock); 279 TAILQ_INSERT_TAIL(&event_list, ie, ie_list); 280 mtx_unlock(&event_lock); 281 if (event != NULL) 282 *event = ie; 283 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name); 284 return (0); 285 } 286 287 /* 288 * Bind an interrupt event to the specified CPU. Note that not all 289 * platforms support binding an interrupt to a CPU. For those 290 * platforms this request will fail. For supported platforms, any 291 * associated ithreads as well as the primary interrupt context will 292 * be bound to the specificed CPU. Using a cpu id of NOCPU unbinds 293 * the interrupt event. 294 */ 295 int 296 intr_event_bind(struct intr_event *ie, int cpu) 297 { 298 lwpid_t id; 299 int error; 300 301 /* Need a CPU to bind to. */ 302 if (cpu != NOCPU && CPU_ABSENT(cpu)) 303 return (EINVAL); 304 305 if (ie->ie_assign_cpu == NULL) 306 return (EOPNOTSUPP); 307 308 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR); 309 if (error) 310 return (error); 311 312 /* 313 * If we have any ithreads try to set their mask first to verify 314 * permissions, etc. 315 */ 316 mtx_lock(&ie->ie_lock); 317 if (ie->ie_thread != NULL) { 318 id = ie->ie_thread->it_thread->td_tid; 319 mtx_unlock(&ie->ie_lock); 320 error = cpuset_setithread(id, cpu); 321 if (error) 322 return (error); 323 } else 324 mtx_unlock(&ie->ie_lock); 325 error = ie->ie_assign_cpu(ie->ie_source, cpu); 326 if (error) { 327 mtx_lock(&ie->ie_lock); 328 if (ie->ie_thread != NULL) { 329 cpu = ie->ie_cpu; 330 id = ie->ie_thread->it_thread->td_tid; 331 mtx_unlock(&ie->ie_lock); 332 (void)cpuset_setithread(id, cpu); 333 } else 334 mtx_unlock(&ie->ie_lock); 335 return (error); 336 } 337 338 mtx_lock(&ie->ie_lock); 339 ie->ie_cpu = cpu; 340 mtx_unlock(&ie->ie_lock); 341 342 return (error); 343 } 344 345 static struct intr_event * 346 intr_lookup(int irq) 347 { 348 struct intr_event *ie; 349 350 mtx_lock(&event_lock); 351 TAILQ_FOREACH(ie, &event_list, ie_list) 352 if (ie->ie_irq == irq && 353 (ie->ie_flags & IE_SOFT) == 0 && 354 TAILQ_FIRST(&ie->ie_handlers) != NULL) 355 break; 356 mtx_unlock(&event_lock); 357 return (ie); 358 } 359 360 int 361 intr_setaffinity(int irq, void *m) 362 { 363 struct intr_event *ie; 364 cpuset_t *mask; 365 int cpu, n; 366 367 mask = m; 368 cpu = NOCPU; 369 /* 370 * If we're setting all cpus we can unbind. Otherwise make sure 371 * only one cpu is in the set. 372 */ 373 if (CPU_CMP(cpuset_root, mask)) { 374 for (n = 0; n < CPU_SETSIZE; n++) { 375 if (!CPU_ISSET(n, mask)) 376 continue; 377 if (cpu != NOCPU) 378 return (EINVAL); 379 cpu = n; 380 } 381 } 382 ie = intr_lookup(irq); 383 if (ie == NULL) 384 return (ESRCH); 385 return (intr_event_bind(ie, cpu)); 386 } 387 388 int 389 intr_getaffinity(int irq, void *m) 390 { 391 struct intr_event *ie; 392 cpuset_t *mask; 393 394 mask = m; 395 ie = intr_lookup(irq); 396 if (ie == NULL) 397 return (ESRCH); 398 CPU_ZERO(mask); 399 mtx_lock(&ie->ie_lock); 400 if (ie->ie_cpu == NOCPU) 401 CPU_COPY(cpuset_root, mask); 402 else 403 CPU_SET(ie->ie_cpu, mask); 404 mtx_unlock(&ie->ie_lock); 405 return (0); 406 } 407 408 int 409 intr_event_destroy(struct intr_event *ie) 410 { 411 412 mtx_lock(&event_lock); 413 mtx_lock(&ie->ie_lock); 414 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 415 mtx_unlock(&ie->ie_lock); 416 mtx_unlock(&event_lock); 417 return (EBUSY); 418 } 419 TAILQ_REMOVE(&event_list, ie, ie_list); 420 #ifndef notyet 421 if (ie->ie_thread != NULL) { 422 ithread_destroy(ie->ie_thread); 423 ie->ie_thread = NULL; 424 } 425 #endif 426 mtx_unlock(&ie->ie_lock); 427 mtx_unlock(&event_lock); 428 mtx_destroy(&ie->ie_lock); 429 free(ie, M_ITHREAD); 430 return (0); 431 } 432 433 #ifndef INTR_FILTER 434 static struct intr_thread * 435 ithread_create(const char *name) 436 { 437 struct intr_thread *ithd; 438 struct thread *td; 439 int error; 440 441 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 442 443 error = kproc_kthread_add(ithread_loop, ithd, &intrproc, 444 &td, RFSTOPPED | RFHIGHPID, 445 0, "intr", "%s", name); 446 if (error) 447 panic("kproc_create() failed with %d", error); 448 thread_lock(td); 449 sched_class(td, PRI_ITHD); 450 TD_SET_IWAIT(td); 451 thread_unlock(td); 452 td->td_pflags |= TDP_ITHREAD; 453 ithd->it_thread = td; 454 CTR2(KTR_INTR, "%s: created %s", __func__, name); 455 return (ithd); 456 } 457 #else 458 static struct intr_thread * 459 ithread_create(const char *name, struct intr_handler *ih) 460 { 461 struct intr_thread *ithd; 462 struct thread *td; 463 int error; 464 465 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 466 467 error = kproc_kthread_add(ithread_loop, ih, &intrproc, 468 &td, RFSTOPPED | RFHIGHPID, 469 0, "intr", "%s", name); 470 if (error) 471 panic("kproc_create() failed with %d", error); 472 thread_lock(td); 473 sched_class(td, PRI_ITHD); 474 TD_SET_IWAIT(td); 475 thread_unlock(td); 476 td->td_pflags |= TDP_ITHREAD; 477 ithd->it_thread = td; 478 CTR2(KTR_INTR, "%s: created %s", __func__, name); 479 return (ithd); 480 } 481 #endif 482 483 static void 484 ithread_destroy(struct intr_thread *ithread) 485 { 486 struct thread *td; 487 488 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name); 489 td = ithread->it_thread; 490 thread_lock(td); 491 ithread->it_flags |= IT_DEAD; 492 if (TD_AWAITING_INTR(td)) { 493 TD_CLR_IWAIT(td); 494 sched_add(td, SRQ_INTR); 495 } 496 thread_unlock(td); 497 } 498 499 #ifndef INTR_FILTER 500 int 501 intr_event_add_handler(struct intr_event *ie, const char *name, 502 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 503 enum intr_type flags, void **cookiep) 504 { 505 struct intr_handler *ih, *temp_ih; 506 struct intr_thread *it; 507 508 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 509 return (EINVAL); 510 511 /* Allocate and populate an interrupt handler structure. */ 512 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 513 ih->ih_filter = filter; 514 ih->ih_handler = handler; 515 ih->ih_argument = arg; 516 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 517 ih->ih_event = ie; 518 ih->ih_pri = pri; 519 if (flags & INTR_EXCL) 520 ih->ih_flags = IH_EXCLUSIVE; 521 if (flags & INTR_MPSAFE) 522 ih->ih_flags |= IH_MPSAFE; 523 if (flags & INTR_ENTROPY) 524 ih->ih_flags |= IH_ENTROPY; 525 526 /* We can only have one exclusive handler in a event. */ 527 mtx_lock(&ie->ie_lock); 528 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 529 if ((flags & INTR_EXCL) || 530 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 531 mtx_unlock(&ie->ie_lock); 532 free(ih, M_ITHREAD); 533 return (EINVAL); 534 } 535 } 536 537 /* Create a thread if we need one. */ 538 while (ie->ie_thread == NULL && handler != NULL) { 539 if (ie->ie_flags & IE_ADDING_THREAD) 540 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 541 else { 542 ie->ie_flags |= IE_ADDING_THREAD; 543 mtx_unlock(&ie->ie_lock); 544 it = ithread_create("intr: newborn"); 545 mtx_lock(&ie->ie_lock); 546 ie->ie_flags &= ~IE_ADDING_THREAD; 547 ie->ie_thread = it; 548 it->it_event = ie; 549 ithread_update(it); 550 wakeup(ie); 551 } 552 } 553 554 /* Add the new handler to the event in priority order. */ 555 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) { 556 if (temp_ih->ih_pri > ih->ih_pri) 557 break; 558 } 559 if (temp_ih == NULL) 560 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next); 561 else 562 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 563 intr_event_update(ie); 564 565 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 566 ie->ie_name); 567 mtx_unlock(&ie->ie_lock); 568 569 if (cookiep != NULL) 570 *cookiep = ih; 571 return (0); 572 } 573 #else 574 int 575 intr_event_add_handler(struct intr_event *ie, const char *name, 576 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 577 enum intr_type flags, void **cookiep) 578 { 579 struct intr_handler *ih, *temp_ih; 580 struct intr_thread *it; 581 582 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 583 return (EINVAL); 584 585 /* Allocate and populate an interrupt handler structure. */ 586 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 587 ih->ih_filter = filter; 588 ih->ih_handler = handler; 589 ih->ih_argument = arg; 590 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 591 ih->ih_event = ie; 592 ih->ih_pri = pri; 593 if (flags & INTR_EXCL) 594 ih->ih_flags = IH_EXCLUSIVE; 595 if (flags & INTR_MPSAFE) 596 ih->ih_flags |= IH_MPSAFE; 597 if (flags & INTR_ENTROPY) 598 ih->ih_flags |= IH_ENTROPY; 599 600 /* We can only have one exclusive handler in a event. */ 601 mtx_lock(&ie->ie_lock); 602 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 603 if ((flags & INTR_EXCL) || 604 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 605 mtx_unlock(&ie->ie_lock); 606 free(ih, M_ITHREAD); 607 return (EINVAL); 608 } 609 } 610 611 /* For filtered handlers, create a private ithread to run on. */ 612 if (filter != NULL && handler != NULL) { 613 mtx_unlock(&ie->ie_lock); 614 it = ithread_create("intr: newborn", ih); 615 mtx_lock(&ie->ie_lock); 616 it->it_event = ie; 617 ih->ih_thread = it; 618 ithread_update(it); /* XXX - do we really need this?!?!? */ 619 } else { /* Create the global per-event thread if we need one. */ 620 while (ie->ie_thread == NULL && handler != NULL) { 621 if (ie->ie_flags & IE_ADDING_THREAD) 622 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 623 else { 624 ie->ie_flags |= IE_ADDING_THREAD; 625 mtx_unlock(&ie->ie_lock); 626 it = ithread_create("intr: newborn", ih); 627 mtx_lock(&ie->ie_lock); 628 ie->ie_flags &= ~IE_ADDING_THREAD; 629 ie->ie_thread = it; 630 it->it_event = ie; 631 ithread_update(it); 632 wakeup(ie); 633 } 634 } 635 } 636 637 /* Add the new handler to the event in priority order. */ 638 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) { 639 if (temp_ih->ih_pri > ih->ih_pri) 640 break; 641 } 642 if (temp_ih == NULL) 643 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next); 644 else 645 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 646 intr_event_update(ie); 647 648 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 649 ie->ie_name); 650 mtx_unlock(&ie->ie_lock); 651 652 if (cookiep != NULL) 653 *cookiep = ih; 654 return (0); 655 } 656 #endif 657 658 /* 659 * Append a description preceded by a ':' to the name of the specified 660 * interrupt handler. 661 */ 662 int 663 intr_event_describe_handler(struct intr_event *ie, void *cookie, 664 const char *descr) 665 { 666 struct intr_handler *ih; 667 size_t space; 668 char *start; 669 670 mtx_lock(&ie->ie_lock); 671 #ifdef INVARIANTS 672 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 673 if (ih == cookie) 674 break; 675 } 676 if (ih == NULL) { 677 mtx_unlock(&ie->ie_lock); 678 panic("handler %p not found in interrupt event %p", cookie, ie); 679 } 680 #endif 681 ih = cookie; 682 683 /* 684 * Look for an existing description by checking for an 685 * existing ":". This assumes device names do not include 686 * colons. If one is found, prepare to insert the new 687 * description at that point. If one is not found, find the 688 * end of the name to use as the insertion point. 689 */ 690 start = strchr(ih->ih_name, ':'); 691 if (start == NULL) 692 start = strchr(ih->ih_name, 0); 693 694 /* 695 * See if there is enough remaining room in the string for the 696 * description + ":". The "- 1" leaves room for the trailing 697 * '\0'. The "+ 1" accounts for the colon. 698 */ 699 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1; 700 if (strlen(descr) + 1 > space) { 701 mtx_unlock(&ie->ie_lock); 702 return (ENOSPC); 703 } 704 705 /* Append a colon followed by the description. */ 706 *start = ':'; 707 strcpy(start + 1, descr); 708 intr_event_update(ie); 709 mtx_unlock(&ie->ie_lock); 710 return (0); 711 } 712 713 /* 714 * Return the ie_source field from the intr_event an intr_handler is 715 * associated with. 716 */ 717 void * 718 intr_handler_source(void *cookie) 719 { 720 struct intr_handler *ih; 721 struct intr_event *ie; 722 723 ih = (struct intr_handler *)cookie; 724 if (ih == NULL) 725 return (NULL); 726 ie = ih->ih_event; 727 KASSERT(ie != NULL, 728 ("interrupt handler \"%s\" has a NULL interrupt event", 729 ih->ih_name)); 730 return (ie->ie_source); 731 } 732 733 /* 734 * Sleep until an ithread finishes executing an interrupt handler. 735 * 736 * XXX Doesn't currently handle interrupt filters or fast interrupt 737 * handlers. This is intended for compatibility with linux drivers 738 * only. Do not use in BSD code. 739 */ 740 void 741 _intr_drain(int irq) 742 { 743 struct intr_event *ie; 744 struct intr_thread *ithd; 745 struct thread *td; 746 747 ie = intr_lookup(irq); 748 if (ie == NULL) 749 return; 750 if (ie->ie_thread == NULL) 751 return; 752 ithd = ie->ie_thread; 753 td = ithd->it_thread; 754 /* 755 * We set the flag and wait for it to be cleared to avoid 756 * long delays with potentially busy interrupt handlers 757 * were we to only sample TD_AWAITING_INTR() every tick. 758 */ 759 thread_lock(td); 760 if (!TD_AWAITING_INTR(td)) { 761 ithd->it_flags |= IT_WAIT; 762 while (ithd->it_flags & IT_WAIT) { 763 thread_unlock(td); 764 pause("idrain", 1); 765 thread_lock(td); 766 } 767 } 768 thread_unlock(td); 769 return; 770 } 771 772 773 #ifndef INTR_FILTER 774 int 775 intr_event_remove_handler(void *cookie) 776 { 777 struct intr_handler *handler = (struct intr_handler *)cookie; 778 struct intr_event *ie; 779 #ifdef INVARIANTS 780 struct intr_handler *ih; 781 #endif 782 #ifdef notyet 783 int dead; 784 #endif 785 786 if (handler == NULL) 787 return (EINVAL); 788 ie = handler->ih_event; 789 KASSERT(ie != NULL, 790 ("interrupt handler \"%s\" has a NULL interrupt event", 791 handler->ih_name)); 792 mtx_lock(&ie->ie_lock); 793 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 794 ie->ie_name); 795 #ifdef INVARIANTS 796 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 797 if (ih == handler) 798 goto ok; 799 mtx_unlock(&ie->ie_lock); 800 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"", 801 ih->ih_name, ie->ie_name); 802 ok: 803 #endif 804 /* 805 * If there is no ithread, then just remove the handler and return. 806 * XXX: Note that an INTR_FAST handler might be running on another 807 * CPU! 808 */ 809 if (ie->ie_thread == NULL) { 810 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 811 mtx_unlock(&ie->ie_lock); 812 free(handler, M_ITHREAD); 813 return (0); 814 } 815 816 /* 817 * If the interrupt thread is already running, then just mark this 818 * handler as being dead and let the ithread do the actual removal. 819 * 820 * During a cold boot while cold is set, msleep() does not sleep, 821 * so we have to remove the handler here rather than letting the 822 * thread do it. 823 */ 824 thread_lock(ie->ie_thread->it_thread); 825 if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) { 826 handler->ih_flags |= IH_DEAD; 827 828 /* 829 * Ensure that the thread will process the handler list 830 * again and remove this handler if it has already passed 831 * it on the list. 832 * 833 * The release part of the following store ensures 834 * that the update of ih_flags is ordered before the 835 * it_need setting. See the comment before 836 * atomic_cmpset_acq(&ithd->it_need, ...) operation in 837 * the ithread_execute_handlers(). 838 */ 839 atomic_store_rel_int(&ie->ie_thread->it_need, 1); 840 } else 841 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 842 thread_unlock(ie->ie_thread->it_thread); 843 while (handler->ih_flags & IH_DEAD) 844 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 845 intr_event_update(ie); 846 #ifdef notyet 847 /* 848 * XXX: This could be bad in the case of ppbus(8). Also, I think 849 * this could lead to races of stale data when servicing an 850 * interrupt. 851 */ 852 dead = 1; 853 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 854 if (!(ih->ih_flags & IH_FAST)) { 855 dead = 0; 856 break; 857 } 858 } 859 if (dead) { 860 ithread_destroy(ie->ie_thread); 861 ie->ie_thread = NULL; 862 } 863 #endif 864 mtx_unlock(&ie->ie_lock); 865 free(handler, M_ITHREAD); 866 return (0); 867 } 868 869 static int 870 intr_event_schedule_thread(struct intr_event *ie) 871 { 872 struct intr_entropy entropy; 873 struct intr_thread *it; 874 struct thread *td; 875 struct thread *ctd; 876 struct proc *p; 877 878 /* 879 * If no ithread or no handlers, then we have a stray interrupt. 880 */ 881 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || 882 ie->ie_thread == NULL) 883 return (EINVAL); 884 885 ctd = curthread; 886 it = ie->ie_thread; 887 td = it->it_thread; 888 p = td->td_proc; 889 890 /* 891 * If any of the handlers for this ithread claim to be good 892 * sources of entropy, then gather some. 893 */ 894 if (ie->ie_flags & IE_ENTROPY) { 895 entropy.event = (uintptr_t)ie; 896 entropy.td = ctd; 897 random_harvest_queue(&entropy, sizeof(entropy), 2, RANDOM_INTERRUPT); 898 } 899 900 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name)); 901 902 /* 903 * Set it_need to tell the thread to keep running if it is already 904 * running. Then, lock the thread and see if we actually need to 905 * put it on the runqueue. 906 * 907 * Use store_rel to arrange that the store to ih_need in 908 * swi_sched() is before the store to it_need and prepare for 909 * transfer of this order to loads in the ithread. 910 */ 911 atomic_store_rel_int(&it->it_need, 1); 912 thread_lock(td); 913 if (TD_AWAITING_INTR(td)) { 914 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid, 915 td->td_name); 916 TD_CLR_IWAIT(td); 917 sched_add(td, SRQ_INTR); 918 } else { 919 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 920 __func__, p->p_pid, td->td_name, it->it_need, td->td_state); 921 } 922 thread_unlock(td); 923 924 return (0); 925 } 926 #else 927 int 928 intr_event_remove_handler(void *cookie) 929 { 930 struct intr_handler *handler = (struct intr_handler *)cookie; 931 struct intr_event *ie; 932 struct intr_thread *it; 933 #ifdef INVARIANTS 934 struct intr_handler *ih; 935 #endif 936 #ifdef notyet 937 int dead; 938 #endif 939 940 if (handler == NULL) 941 return (EINVAL); 942 ie = handler->ih_event; 943 KASSERT(ie != NULL, 944 ("interrupt handler \"%s\" has a NULL interrupt event", 945 handler->ih_name)); 946 mtx_lock(&ie->ie_lock); 947 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 948 ie->ie_name); 949 #ifdef INVARIANTS 950 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 951 if (ih == handler) 952 goto ok; 953 mtx_unlock(&ie->ie_lock); 954 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"", 955 ih->ih_name, ie->ie_name); 956 ok: 957 #endif 958 /* 959 * If there are no ithreads (per event and per handler), then 960 * just remove the handler and return. 961 * XXX: Note that an INTR_FAST handler might be running on another CPU! 962 */ 963 if (ie->ie_thread == NULL && handler->ih_thread == NULL) { 964 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 965 mtx_unlock(&ie->ie_lock); 966 free(handler, M_ITHREAD); 967 return (0); 968 } 969 970 /* Private or global ithread? */ 971 it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread; 972 /* 973 * If the interrupt thread is already running, then just mark this 974 * handler as being dead and let the ithread do the actual removal. 975 * 976 * During a cold boot while cold is set, msleep() does not sleep, 977 * so we have to remove the handler here rather than letting the 978 * thread do it. 979 */ 980 thread_lock(it->it_thread); 981 if (!TD_AWAITING_INTR(it->it_thread) && !cold) { 982 handler->ih_flags |= IH_DEAD; 983 984 /* 985 * Ensure that the thread will process the handler list 986 * again and remove this handler if it has already passed 987 * it on the list. 988 * 989 * The release part of the following store ensures 990 * that the update of ih_flags is ordered before the 991 * it_need setting. See the comment before 992 * atomic_cmpset_acq(&ithd->it_need, ...) operation in 993 * the ithread_execute_handlers(). 994 */ 995 atomic_store_rel_int(&it->it_need, 1); 996 } else 997 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 998 thread_unlock(it->it_thread); 999 while (handler->ih_flags & IH_DEAD) 1000 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 1001 /* 1002 * At this point, the handler has been disconnected from the event, 1003 * so we can kill the private ithread if any. 1004 */ 1005 if (handler->ih_thread) { 1006 ithread_destroy(handler->ih_thread); 1007 handler->ih_thread = NULL; 1008 } 1009 intr_event_update(ie); 1010 #ifdef notyet 1011 /* 1012 * XXX: This could be bad in the case of ppbus(8). Also, I think 1013 * this could lead to races of stale data when servicing an 1014 * interrupt. 1015 */ 1016 dead = 1; 1017 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1018 if (handler != NULL) { 1019 dead = 0; 1020 break; 1021 } 1022 } 1023 if (dead) { 1024 ithread_destroy(ie->ie_thread); 1025 ie->ie_thread = NULL; 1026 } 1027 #endif 1028 mtx_unlock(&ie->ie_lock); 1029 free(handler, M_ITHREAD); 1030 return (0); 1031 } 1032 1033 static int 1034 intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it) 1035 { 1036 struct intr_entropy entropy; 1037 struct thread *td; 1038 struct thread *ctd; 1039 struct proc *p; 1040 1041 /* 1042 * If no ithread or no handlers, then we have a stray interrupt. 1043 */ 1044 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || it == NULL) 1045 return (EINVAL); 1046 1047 ctd = curthread; 1048 td = it->it_thread; 1049 p = td->td_proc; 1050 1051 /* 1052 * If any of the handlers for this ithread claim to be good 1053 * sources of entropy, then gather some. 1054 */ 1055 if (ie->ie_flags & IE_ENTROPY) { 1056 entropy.event = (uintptr_t)ie; 1057 entropy.td = ctd; 1058 random_harvest_queue(&entropy, sizeof(entropy), 2, RANDOM_INTERRUPT); 1059 } 1060 1061 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name)); 1062 1063 /* 1064 * Set it_need to tell the thread to keep running if it is already 1065 * running. Then, lock the thread and see if we actually need to 1066 * put it on the runqueue. 1067 * 1068 * Use store_rel to arrange that the store to ih_need in 1069 * swi_sched() is before the store to it_need and prepare for 1070 * transfer of this order to loads in the ithread. 1071 */ 1072 atomic_store_rel_int(&it->it_need, 1); 1073 thread_lock(td); 1074 if (TD_AWAITING_INTR(td)) { 1075 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid, 1076 td->td_name); 1077 TD_CLR_IWAIT(td); 1078 sched_add(td, SRQ_INTR); 1079 } else { 1080 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 1081 __func__, p->p_pid, td->td_name, it->it_need, td->td_state); 1082 } 1083 thread_unlock(td); 1084 1085 return (0); 1086 } 1087 #endif 1088 1089 /* 1090 * Allow interrupt event binding for software interrupt handlers -- a no-op, 1091 * since interrupts are generated in software rather than being directed by 1092 * a PIC. 1093 */ 1094 static int 1095 swi_assign_cpu(void *arg, int cpu) 1096 { 1097 1098 return (0); 1099 } 1100 1101 /* 1102 * Add a software interrupt handler to a specified event. If a given event 1103 * is not specified, then a new event is created. 1104 */ 1105 int 1106 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler, 1107 void *arg, int pri, enum intr_type flags, void **cookiep) 1108 { 1109 struct intr_event *ie; 1110 int error; 1111 1112 if (flags & INTR_ENTROPY) 1113 return (EINVAL); 1114 1115 ie = (eventp != NULL) ? *eventp : NULL; 1116 1117 if (ie != NULL) { 1118 if (!(ie->ie_flags & IE_SOFT)) 1119 return (EINVAL); 1120 } else { 1121 error = intr_event_create(&ie, NULL, IE_SOFT, 0, 1122 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri); 1123 if (error) 1124 return (error); 1125 if (eventp != NULL) 1126 *eventp = ie; 1127 } 1128 error = intr_event_add_handler(ie, name, NULL, handler, arg, 1129 PI_SWI(pri), flags, cookiep); 1130 return (error); 1131 } 1132 1133 /* 1134 * Schedule a software interrupt thread. 1135 */ 1136 void 1137 swi_sched(void *cookie, int flags) 1138 { 1139 struct intr_handler *ih = (struct intr_handler *)cookie; 1140 struct intr_event *ie = ih->ih_event; 1141 struct intr_entropy entropy; 1142 int error; 1143 1144 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name, 1145 ih->ih_need); 1146 1147 entropy.event = (uintptr_t)ih; 1148 entropy.td = curthread; 1149 random_harvest_queue(&entropy, sizeof(entropy), 1, RANDOM_SWI); 1150 1151 /* 1152 * Set ih_need for this handler so that if the ithread is already 1153 * running it will execute this handler on the next pass. Otherwise, 1154 * it will execute it the next time it runs. 1155 */ 1156 ih->ih_need = 1; 1157 1158 if (!(flags & SWI_DELAY)) { 1159 PCPU_INC(cnt.v_soft); 1160 #ifdef INTR_FILTER 1161 error = intr_event_schedule_thread(ie, ie->ie_thread); 1162 #else 1163 error = intr_event_schedule_thread(ie); 1164 #endif 1165 KASSERT(error == 0, ("stray software interrupt")); 1166 } 1167 } 1168 1169 /* 1170 * Remove a software interrupt handler. Currently this code does not 1171 * remove the associated interrupt event if it becomes empty. Calling code 1172 * may do so manually via intr_event_destroy(), but that's not really 1173 * an optimal interface. 1174 */ 1175 int 1176 swi_remove(void *cookie) 1177 { 1178 1179 return (intr_event_remove_handler(cookie)); 1180 } 1181 1182 #ifdef INTR_FILTER 1183 static void 1184 priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih) 1185 { 1186 struct intr_event *ie; 1187 1188 ie = ih->ih_event; 1189 /* 1190 * If this handler is marked for death, remove it from 1191 * the list of handlers and wake up the sleeper. 1192 */ 1193 if (ih->ih_flags & IH_DEAD) { 1194 mtx_lock(&ie->ie_lock); 1195 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next); 1196 ih->ih_flags &= ~IH_DEAD; 1197 wakeup(ih); 1198 mtx_unlock(&ie->ie_lock); 1199 return; 1200 } 1201 1202 /* Execute this handler. */ 1203 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1204 __func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument, 1205 ih->ih_name, ih->ih_flags); 1206 1207 if (!(ih->ih_flags & IH_MPSAFE)) 1208 mtx_lock(&Giant); 1209 ih->ih_handler(ih->ih_argument); 1210 if (!(ih->ih_flags & IH_MPSAFE)) 1211 mtx_unlock(&Giant); 1212 } 1213 #endif 1214 1215 /* 1216 * This is a public function for use by drivers that mux interrupt 1217 * handlers for child devices from their interrupt handler. 1218 */ 1219 void 1220 intr_event_execute_handlers(struct proc *p, struct intr_event *ie) 1221 { 1222 struct intr_handler *ih, *ihn; 1223 1224 TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) { 1225 /* 1226 * If this handler is marked for death, remove it from 1227 * the list of handlers and wake up the sleeper. 1228 */ 1229 if (ih->ih_flags & IH_DEAD) { 1230 mtx_lock(&ie->ie_lock); 1231 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next); 1232 ih->ih_flags &= ~IH_DEAD; 1233 wakeup(ih); 1234 mtx_unlock(&ie->ie_lock); 1235 continue; 1236 } 1237 1238 /* Skip filter only handlers */ 1239 if (ih->ih_handler == NULL) 1240 continue; 1241 1242 /* 1243 * For software interrupt threads, we only execute 1244 * handlers that have their need flag set. Hardware 1245 * interrupt threads always invoke all of their handlers. 1246 * 1247 * ih_need can only be 0 or 1. Failed cmpset below 1248 * means that there is no request to execute handlers, 1249 * so a retry of the cmpset is not needed. 1250 */ 1251 if ((ie->ie_flags & IE_SOFT) != 0 && 1252 atomic_cmpset_int(&ih->ih_need, 1, 0) == 0) 1253 continue; 1254 1255 /* Execute this handler. */ 1256 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1257 __func__, p->p_pid, (void *)ih->ih_handler, 1258 ih->ih_argument, ih->ih_name, ih->ih_flags); 1259 1260 if (!(ih->ih_flags & IH_MPSAFE)) 1261 mtx_lock(&Giant); 1262 ih->ih_handler(ih->ih_argument); 1263 if (!(ih->ih_flags & IH_MPSAFE)) 1264 mtx_unlock(&Giant); 1265 } 1266 } 1267 1268 static void 1269 ithread_execute_handlers(struct proc *p, struct intr_event *ie) 1270 { 1271 1272 /* Interrupt handlers should not sleep. */ 1273 if (!(ie->ie_flags & IE_SOFT)) 1274 THREAD_NO_SLEEPING(); 1275 intr_event_execute_handlers(p, ie); 1276 if (!(ie->ie_flags & IE_SOFT)) 1277 THREAD_SLEEPING_OK(); 1278 1279 /* 1280 * Interrupt storm handling: 1281 * 1282 * If this interrupt source is currently storming, then throttle 1283 * it to only fire the handler once per clock tick. 1284 * 1285 * If this interrupt source is not currently storming, but the 1286 * number of back to back interrupts exceeds the storm threshold, 1287 * then enter storming mode. 1288 */ 1289 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold && 1290 !(ie->ie_flags & IE_SOFT)) { 1291 /* Report the message only once every second. */ 1292 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) { 1293 printf( 1294 "interrupt storm detected on \"%s\"; throttling interrupt source\n", 1295 ie->ie_name); 1296 } 1297 pause("istorm", 1); 1298 } else 1299 ie->ie_count++; 1300 1301 /* 1302 * Now that all the handlers have had a chance to run, reenable 1303 * the interrupt source. 1304 */ 1305 if (ie->ie_post_ithread != NULL) 1306 ie->ie_post_ithread(ie->ie_source); 1307 } 1308 1309 #ifndef INTR_FILTER 1310 /* 1311 * This is the main code for interrupt threads. 1312 */ 1313 static void 1314 ithread_loop(void *arg) 1315 { 1316 struct intr_thread *ithd; 1317 struct intr_event *ie; 1318 struct thread *td; 1319 struct proc *p; 1320 int wake; 1321 1322 td = curthread; 1323 p = td->td_proc; 1324 ithd = (struct intr_thread *)arg; 1325 KASSERT(ithd->it_thread == td, 1326 ("%s: ithread and proc linkage out of sync", __func__)); 1327 ie = ithd->it_event; 1328 ie->ie_count = 0; 1329 wake = 0; 1330 1331 /* 1332 * As long as we have interrupts outstanding, go through the 1333 * list of handlers, giving each one a go at it. 1334 */ 1335 for (;;) { 1336 /* 1337 * If we are an orphaned thread, then just die. 1338 */ 1339 if (ithd->it_flags & IT_DEAD) { 1340 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1341 p->p_pid, td->td_name); 1342 free(ithd, M_ITHREAD); 1343 kthread_exit(); 1344 } 1345 1346 /* 1347 * Service interrupts. If another interrupt arrives while 1348 * we are running, it will set it_need to note that we 1349 * should make another pass. 1350 * 1351 * The load_acq part of the following cmpset ensures 1352 * that the load of ih_need in ithread_execute_handlers() 1353 * is ordered after the load of it_need here. 1354 */ 1355 while (atomic_cmpset_acq_int(&ithd->it_need, 1, 0) != 0) 1356 ithread_execute_handlers(p, ie); 1357 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1358 mtx_assert(&Giant, MA_NOTOWNED); 1359 1360 /* 1361 * Processed all our interrupts. Now get the sched 1362 * lock. This may take a while and it_need may get 1363 * set again, so we have to check it again. 1364 */ 1365 thread_lock(td); 1366 if (atomic_load_acq_int(&ithd->it_need) == 0 && 1367 (ithd->it_flags & (IT_DEAD | IT_WAIT)) == 0) { 1368 TD_SET_IWAIT(td); 1369 ie->ie_count = 0; 1370 mi_switch(SW_VOL | SWT_IWAIT, NULL); 1371 } 1372 if (ithd->it_flags & IT_WAIT) { 1373 wake = 1; 1374 ithd->it_flags &= ~IT_WAIT; 1375 } 1376 thread_unlock(td); 1377 if (wake) { 1378 wakeup(ithd); 1379 wake = 0; 1380 } 1381 } 1382 } 1383 1384 /* 1385 * Main interrupt handling body. 1386 * 1387 * Input: 1388 * o ie: the event connected to this interrupt. 1389 * o frame: some archs (i.e. i386) pass a frame to some. 1390 * handlers as their main argument. 1391 * Return value: 1392 * o 0: everything ok. 1393 * o EINVAL: stray interrupt. 1394 */ 1395 int 1396 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1397 { 1398 struct intr_handler *ih; 1399 struct trapframe *oldframe; 1400 struct thread *td; 1401 int error, ret, thread; 1402 1403 td = curthread; 1404 1405 #ifdef KSTACK_USAGE_PROF 1406 intr_prof_stack_use(td, frame); 1407 #endif 1408 1409 /* An interrupt with no event or handlers is a stray interrupt. */ 1410 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers)) 1411 return (EINVAL); 1412 1413 /* 1414 * Execute fast interrupt handlers directly. 1415 * To support clock handlers, if a handler registers 1416 * with a NULL argument, then we pass it a pointer to 1417 * a trapframe as its argument. 1418 */ 1419 td->td_intr_nesting_level++; 1420 thread = 0; 1421 ret = 0; 1422 critical_enter(); 1423 oldframe = td->td_intr_frame; 1424 td->td_intr_frame = frame; 1425 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1426 if (ih->ih_filter == NULL) { 1427 thread = 1; 1428 continue; 1429 } 1430 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__, 1431 ih->ih_filter, ih->ih_argument == NULL ? frame : 1432 ih->ih_argument, ih->ih_name); 1433 if (ih->ih_argument == NULL) 1434 ret = ih->ih_filter(frame); 1435 else 1436 ret = ih->ih_filter(ih->ih_argument); 1437 KASSERT(ret == FILTER_STRAY || 1438 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1439 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1440 ("%s: incorrect return value %#x from %s", __func__, ret, 1441 ih->ih_name)); 1442 1443 /* 1444 * Wrapper handler special handling: 1445 * 1446 * in some particular cases (like pccard and pccbb), 1447 * the _real_ device handler is wrapped in a couple of 1448 * functions - a filter wrapper and an ithread wrapper. 1449 * In this case (and just in this case), the filter wrapper 1450 * could ask the system to schedule the ithread and mask 1451 * the interrupt source if the wrapped handler is composed 1452 * of just an ithread handler. 1453 * 1454 * TODO: write a generic wrapper to avoid people rolling 1455 * their own 1456 */ 1457 if (!thread) { 1458 if (ret == FILTER_SCHEDULE_THREAD) 1459 thread = 1; 1460 } 1461 } 1462 td->td_intr_frame = oldframe; 1463 1464 if (thread) { 1465 if (ie->ie_pre_ithread != NULL) 1466 ie->ie_pre_ithread(ie->ie_source); 1467 } else { 1468 if (ie->ie_post_filter != NULL) 1469 ie->ie_post_filter(ie->ie_source); 1470 } 1471 1472 /* Schedule the ithread if needed. */ 1473 if (thread) { 1474 error = intr_event_schedule_thread(ie); 1475 KASSERT(error == 0, ("bad stray interrupt")); 1476 } 1477 critical_exit(); 1478 td->td_intr_nesting_level--; 1479 return (0); 1480 } 1481 #else 1482 /* 1483 * This is the main code for interrupt threads. 1484 */ 1485 static void 1486 ithread_loop(void *arg) 1487 { 1488 struct intr_thread *ithd; 1489 struct intr_handler *ih; 1490 struct intr_event *ie; 1491 struct thread *td; 1492 struct proc *p; 1493 int priv; 1494 int wake; 1495 1496 td = curthread; 1497 p = td->td_proc; 1498 ih = (struct intr_handler *)arg; 1499 priv = (ih->ih_thread != NULL) ? 1 : 0; 1500 ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread; 1501 KASSERT(ithd->it_thread == td, 1502 ("%s: ithread and proc linkage out of sync", __func__)); 1503 ie = ithd->it_event; 1504 ie->ie_count = 0; 1505 wake = 0; 1506 1507 /* 1508 * As long as we have interrupts outstanding, go through the 1509 * list of handlers, giving each one a go at it. 1510 */ 1511 for (;;) { 1512 /* 1513 * If we are an orphaned thread, then just die. 1514 */ 1515 if (ithd->it_flags & IT_DEAD) { 1516 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1517 p->p_pid, td->td_name); 1518 free(ithd, M_ITHREAD); 1519 kthread_exit(); 1520 } 1521 1522 /* 1523 * Service interrupts. If another interrupt arrives while 1524 * we are running, it will set it_need to note that we 1525 * should make another pass. 1526 * 1527 * The load_acq part of the following cmpset ensures 1528 * that the load of ih_need in ithread_execute_handlers() 1529 * is ordered after the load of it_need here. 1530 */ 1531 while (atomic_cmpset_acq_int(&ithd->it_need, 1, 0) != 0) { 1532 if (priv) 1533 priv_ithread_execute_handler(p, ih); 1534 else 1535 ithread_execute_handlers(p, ie); 1536 } 1537 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1538 mtx_assert(&Giant, MA_NOTOWNED); 1539 1540 /* 1541 * Processed all our interrupts. Now get the sched 1542 * lock. This may take a while and it_need may get 1543 * set again, so we have to check it again. 1544 */ 1545 thread_lock(td); 1546 if (atomic_load_acq_int(&ithd->it_need) == 0 && 1547 (ithd->it_flags & (IT_DEAD | IT_WAIT)) == 0) { 1548 TD_SET_IWAIT(td); 1549 ie->ie_count = 0; 1550 mi_switch(SW_VOL | SWT_IWAIT, NULL); 1551 } 1552 if (ithd->it_flags & IT_WAIT) { 1553 wake = 1; 1554 ithd->it_flags &= ~IT_WAIT; 1555 } 1556 thread_unlock(td); 1557 if (wake) { 1558 wakeup(ithd); 1559 wake = 0; 1560 } 1561 } 1562 } 1563 1564 /* 1565 * Main loop for interrupt filter. 1566 * 1567 * Some architectures (i386, amd64 and arm) require the optional frame 1568 * parameter, and use it as the main argument for fast handler execution 1569 * when ih_argument == NULL. 1570 * 1571 * Return value: 1572 * o FILTER_STRAY: No filter recognized the event, and no 1573 * filter-less handler is registered on this 1574 * line. 1575 * o FILTER_HANDLED: A filter claimed the event and served it. 1576 * o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at 1577 * least one filter-less handler on this line. 1578 * o FILTER_HANDLED | 1579 * FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for 1580 * scheduling the per-handler ithread. 1581 * 1582 * In case an ithread has to be scheduled, in *ithd there will be a 1583 * pointer to a struct intr_thread containing the thread to be 1584 * scheduled. 1585 */ 1586 1587 static int 1588 intr_filter_loop(struct intr_event *ie, struct trapframe *frame, 1589 struct intr_thread **ithd) 1590 { 1591 struct intr_handler *ih; 1592 void *arg; 1593 int ret, thread_only; 1594 1595 ret = 0; 1596 thread_only = 0; 1597 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1598 /* 1599 * Execute fast interrupt handlers directly. 1600 * To support clock handlers, if a handler registers 1601 * with a NULL argument, then we pass it a pointer to 1602 * a trapframe as its argument. 1603 */ 1604 arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument); 1605 1606 CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__, 1607 ih->ih_filter, ih->ih_handler, arg, ih->ih_name); 1608 1609 if (ih->ih_filter != NULL) 1610 ret = ih->ih_filter(arg); 1611 else { 1612 thread_only = 1; 1613 continue; 1614 } 1615 KASSERT(ret == FILTER_STRAY || 1616 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1617 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1618 ("%s: incorrect return value %#x from %s", __func__, ret, 1619 ih->ih_name)); 1620 if (ret & FILTER_STRAY) 1621 continue; 1622 else { 1623 *ithd = ih->ih_thread; 1624 return (ret); 1625 } 1626 } 1627 1628 /* 1629 * No filters handled the interrupt and we have at least 1630 * one handler without a filter. In this case, we schedule 1631 * all of the filter-less handlers to run in the ithread. 1632 */ 1633 if (thread_only) { 1634 *ithd = ie->ie_thread; 1635 return (FILTER_SCHEDULE_THREAD); 1636 } 1637 return (FILTER_STRAY); 1638 } 1639 1640 /* 1641 * Main interrupt handling body. 1642 * 1643 * Input: 1644 * o ie: the event connected to this interrupt. 1645 * o frame: some archs (i.e. i386) pass a frame to some. 1646 * handlers as their main argument. 1647 * Return value: 1648 * o 0: everything ok. 1649 * o EINVAL: stray interrupt. 1650 */ 1651 int 1652 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1653 { 1654 struct intr_thread *ithd; 1655 struct trapframe *oldframe; 1656 struct thread *td; 1657 int thread; 1658 1659 ithd = NULL; 1660 td = curthread; 1661 1662 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers)) 1663 return (EINVAL); 1664 1665 td->td_intr_nesting_level++; 1666 thread = 0; 1667 critical_enter(); 1668 oldframe = td->td_intr_frame; 1669 td->td_intr_frame = frame; 1670 thread = intr_filter_loop(ie, frame, &ithd); 1671 if (thread & FILTER_HANDLED) { 1672 if (ie->ie_post_filter != NULL) 1673 ie->ie_post_filter(ie->ie_source); 1674 } else { 1675 if (ie->ie_pre_ithread != NULL) 1676 ie->ie_pre_ithread(ie->ie_source); 1677 } 1678 td->td_intr_frame = oldframe; 1679 critical_exit(); 1680 1681 /* Interrupt storm logic */ 1682 if (thread & FILTER_STRAY) { 1683 ie->ie_count++; 1684 if (ie->ie_count < intr_storm_threshold) 1685 printf("Interrupt stray detection not present\n"); 1686 } 1687 1688 /* Schedule an ithread if needed. */ 1689 if (thread & FILTER_SCHEDULE_THREAD) { 1690 if (intr_event_schedule_thread(ie, ithd) != 0) 1691 panic("%s: impossible stray interrupt", __func__); 1692 } 1693 td->td_intr_nesting_level--; 1694 return (0); 1695 } 1696 #endif 1697 1698 #ifdef DDB 1699 /* 1700 * Dump details about an interrupt handler 1701 */ 1702 static void 1703 db_dump_intrhand(struct intr_handler *ih) 1704 { 1705 int comma; 1706 1707 db_printf("\t%-10s ", ih->ih_name); 1708 switch (ih->ih_pri) { 1709 case PI_REALTIME: 1710 db_printf("CLK "); 1711 break; 1712 case PI_AV: 1713 db_printf("AV "); 1714 break; 1715 case PI_TTY: 1716 db_printf("TTY "); 1717 break; 1718 case PI_NET: 1719 db_printf("NET "); 1720 break; 1721 case PI_DISK: 1722 db_printf("DISK"); 1723 break; 1724 case PI_DULL: 1725 db_printf("DULL"); 1726 break; 1727 default: 1728 if (ih->ih_pri >= PI_SOFT) 1729 db_printf("SWI "); 1730 else 1731 db_printf("%4u", ih->ih_pri); 1732 break; 1733 } 1734 db_printf(" "); 1735 if (ih->ih_filter != NULL) { 1736 db_printf("[F]"); 1737 db_printsym((uintptr_t)ih->ih_filter, DB_STGY_PROC); 1738 } 1739 if (ih->ih_handler != NULL) { 1740 if (ih->ih_filter != NULL) 1741 db_printf(","); 1742 db_printf("[H]"); 1743 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC); 1744 } 1745 db_printf("(%p)", ih->ih_argument); 1746 if (ih->ih_need || 1747 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD | 1748 IH_MPSAFE)) != 0) { 1749 db_printf(" {"); 1750 comma = 0; 1751 if (ih->ih_flags & IH_EXCLUSIVE) { 1752 if (comma) 1753 db_printf(", "); 1754 db_printf("EXCL"); 1755 comma = 1; 1756 } 1757 if (ih->ih_flags & IH_ENTROPY) { 1758 if (comma) 1759 db_printf(", "); 1760 db_printf("ENTROPY"); 1761 comma = 1; 1762 } 1763 if (ih->ih_flags & IH_DEAD) { 1764 if (comma) 1765 db_printf(", "); 1766 db_printf("DEAD"); 1767 comma = 1; 1768 } 1769 if (ih->ih_flags & IH_MPSAFE) { 1770 if (comma) 1771 db_printf(", "); 1772 db_printf("MPSAFE"); 1773 comma = 1; 1774 } 1775 if (ih->ih_need) { 1776 if (comma) 1777 db_printf(", "); 1778 db_printf("NEED"); 1779 } 1780 db_printf("}"); 1781 } 1782 db_printf("\n"); 1783 } 1784 1785 /* 1786 * Dump details about a event. 1787 */ 1788 void 1789 db_dump_intr_event(struct intr_event *ie, int handlers) 1790 { 1791 struct intr_handler *ih; 1792 struct intr_thread *it; 1793 int comma; 1794 1795 db_printf("%s ", ie->ie_fullname); 1796 it = ie->ie_thread; 1797 if (it != NULL) 1798 db_printf("(pid %d)", it->it_thread->td_proc->p_pid); 1799 else 1800 db_printf("(no thread)"); 1801 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 || 1802 (it != NULL && it->it_need)) { 1803 db_printf(" {"); 1804 comma = 0; 1805 if (ie->ie_flags & IE_SOFT) { 1806 db_printf("SOFT"); 1807 comma = 1; 1808 } 1809 if (ie->ie_flags & IE_ENTROPY) { 1810 if (comma) 1811 db_printf(", "); 1812 db_printf("ENTROPY"); 1813 comma = 1; 1814 } 1815 if (ie->ie_flags & IE_ADDING_THREAD) { 1816 if (comma) 1817 db_printf(", "); 1818 db_printf("ADDING_THREAD"); 1819 comma = 1; 1820 } 1821 if (it != NULL && it->it_need) { 1822 if (comma) 1823 db_printf(", "); 1824 db_printf("NEED"); 1825 } 1826 db_printf("}"); 1827 } 1828 db_printf("\n"); 1829 1830 if (handlers) 1831 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 1832 db_dump_intrhand(ih); 1833 } 1834 1835 /* 1836 * Dump data about interrupt handlers 1837 */ 1838 DB_SHOW_COMMAND(intr, db_show_intr) 1839 { 1840 struct intr_event *ie; 1841 int all, verbose; 1842 1843 verbose = strchr(modif, 'v') != NULL; 1844 all = strchr(modif, 'a') != NULL; 1845 TAILQ_FOREACH(ie, &event_list, ie_list) { 1846 if (!all && TAILQ_EMPTY(&ie->ie_handlers)) 1847 continue; 1848 db_dump_intr_event(ie, verbose); 1849 if (db_pager_quit) 1850 break; 1851 } 1852 } 1853 #endif /* DDB */ 1854 1855 /* 1856 * Start standard software interrupt threads 1857 */ 1858 static void 1859 start_softintr(void *dummy) 1860 { 1861 1862 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih)) 1863 panic("died while creating vm swi ithread"); 1864 } 1865 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, 1866 NULL); 1867 1868 /* 1869 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. 1870 * The data for this machine dependent, and the declarations are in machine 1871 * dependent code. The layout of intrnames and intrcnt however is machine 1872 * independent. 1873 * 1874 * We do not know the length of intrcnt and intrnames at compile time, so 1875 * calculate things at run time. 1876 */ 1877 static int 1878 sysctl_intrnames(SYSCTL_HANDLER_ARGS) 1879 { 1880 return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req)); 1881 } 1882 1883 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD, 1884 NULL, 0, sysctl_intrnames, "", "Interrupt Names"); 1885 1886 static int 1887 sysctl_intrcnt(SYSCTL_HANDLER_ARGS) 1888 { 1889 #ifdef SCTL_MASK32 1890 uint32_t *intrcnt32; 1891 unsigned i; 1892 int error; 1893 1894 if (req->flags & SCTL_MASK32) { 1895 if (!req->oldptr) 1896 return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req)); 1897 intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT); 1898 if (intrcnt32 == NULL) 1899 return (ENOMEM); 1900 for (i = 0; i < sintrcnt / sizeof (u_long); i++) 1901 intrcnt32[i] = intrcnt[i]; 1902 error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req); 1903 free(intrcnt32, M_TEMP); 1904 return (error); 1905 } 1906 #endif 1907 return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req)); 1908 } 1909 1910 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD, 1911 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts"); 1912 1913 #ifdef DDB 1914 /* 1915 * DDB command to dump the interrupt statistics. 1916 */ 1917 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt) 1918 { 1919 u_long *i; 1920 char *cp; 1921 u_int j; 1922 1923 cp = intrnames; 1924 j = 0; 1925 for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit; 1926 i++, j++) { 1927 if (*cp == '\0') 1928 break; 1929 if (*i != 0) 1930 db_printf("%s\t%lu\n", cp, *i); 1931 cp += strlen(cp) + 1; 1932 } 1933 } 1934 #endif
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