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/8.3/sys/kern/kern_intr.c 218352 2011-02-05 21:50:23Z kib $"); 29 30 #include "opt_ddb.h" 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/conf.h> 35 #include <sys/cpuset.h> 36 #include <sys/rtprio.h> 37 #include <sys/systm.h> 38 #include <sys/interrupt.h> 39 #include <sys/kernel.h> 40 #include <sys/kthread.h> 41 #include <sys/ktr.h> 42 #include <sys/limits.h> 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/mutex.h> 46 #include <sys/priv.h> 47 #include <sys/proc.h> 48 #include <sys/random.h> 49 #include <sys/resourcevar.h> 50 #include <sys/sched.h> 51 #include <sys/smp.h> 52 #include <sys/sysctl.h> 53 #include <sys/syslog.h> 54 #include <sys/unistd.h> 55 #include <sys/vmmeter.h> 56 #include <machine/atomic.h> 57 #include <machine/cpu.h> 58 #include <machine/md_var.h> 59 #include <machine/stdarg.h> 60 #ifdef DDB 61 #include <ddb/ddb.h> 62 #include <ddb/db_sym.h> 63 #endif 64 65 /* 66 * Describe an interrupt thread. There is one of these per interrupt event. 67 */ 68 struct intr_thread { 69 struct intr_event *it_event; 70 struct thread *it_thread; /* Kernel thread. */ 71 int it_flags; /* (j) IT_* flags. */ 72 int it_need; /* Needs service. */ 73 }; 74 75 /* Interrupt thread flags kept in it_flags */ 76 #define IT_DEAD 0x000001 /* Thread is waiting to exit. */ 77 78 struct intr_entropy { 79 struct thread *td; 80 uintptr_t event; 81 }; 82 83 struct intr_event *clk_intr_event; 84 struct intr_event *tty_intr_event; 85 void *vm_ih; 86 struct proc *intrproc; 87 88 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads"); 89 90 static int intr_storm_threshold = 1000; 91 TUNABLE_INT("hw.intr_storm_threshold", &intr_storm_threshold); 92 SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RW, 93 &intr_storm_threshold, 0, 94 "Number of consecutive interrupts before storm protection is enabled"); 95 static TAILQ_HEAD(, intr_event) event_list = 96 TAILQ_HEAD_INITIALIZER(event_list); 97 static struct mtx event_lock; 98 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF); 99 100 static void intr_event_update(struct intr_event *ie); 101 #ifdef INTR_FILTER 102 static int intr_event_schedule_thread(struct intr_event *ie, 103 struct intr_thread *ithd); 104 static int intr_filter_loop(struct intr_event *ie, 105 struct trapframe *frame, struct intr_thread **ithd); 106 static struct intr_thread *ithread_create(const char *name, 107 struct intr_handler *ih); 108 #else 109 static int intr_event_schedule_thread(struct intr_event *ie); 110 static struct intr_thread *ithread_create(const char *name); 111 #endif 112 static void ithread_destroy(struct intr_thread *ithread); 113 static void ithread_execute_handlers(struct proc *p, 114 struct intr_event *ie); 115 #ifdef INTR_FILTER 116 static void priv_ithread_execute_handler(struct proc *p, 117 struct intr_handler *ih); 118 #endif 119 static void ithread_loop(void *); 120 static void ithread_update(struct intr_thread *ithd); 121 static void start_softintr(void *); 122 123 /* Map an interrupt type to an ithread priority. */ 124 u_char 125 intr_priority(enum intr_type flags) 126 { 127 u_char pri; 128 129 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET | 130 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV); 131 switch (flags) { 132 case INTR_TYPE_TTY: 133 pri = PI_TTY; 134 break; 135 case INTR_TYPE_BIO: 136 pri = PI_DISK; 137 break; 138 case INTR_TYPE_NET: 139 pri = PI_NET; 140 break; 141 case INTR_TYPE_CAM: 142 pri = PI_DISK; 143 break; 144 case INTR_TYPE_AV: 145 pri = PI_AV; 146 break; 147 case INTR_TYPE_CLK: 148 pri = PI_REALTIME; 149 break; 150 case INTR_TYPE_MISC: 151 pri = PI_DULL; /* don't care */ 152 break; 153 default: 154 /* We didn't specify an interrupt level. */ 155 panic("intr_priority: no interrupt type in flags"); 156 } 157 158 return pri; 159 } 160 161 /* 162 * Update an ithread based on the associated intr_event. 163 */ 164 static void 165 ithread_update(struct intr_thread *ithd) 166 { 167 struct intr_event *ie; 168 struct thread *td; 169 u_char pri; 170 171 ie = ithd->it_event; 172 td = ithd->it_thread; 173 174 /* Determine the overall priority of this event. */ 175 if (TAILQ_EMPTY(&ie->ie_handlers)) 176 pri = PRI_MAX_ITHD; 177 else 178 pri = TAILQ_FIRST(&ie->ie_handlers)->ih_pri; 179 180 /* Update name and priority. */ 181 strlcpy(td->td_name, ie->ie_fullname, sizeof(td->td_name)); 182 thread_lock(td); 183 sched_prio(td, pri); 184 thread_unlock(td); 185 } 186 187 /* 188 * Regenerate the full name of an interrupt event and update its priority. 189 */ 190 static void 191 intr_event_update(struct intr_event *ie) 192 { 193 struct intr_handler *ih; 194 char *last; 195 int missed, space; 196 197 /* Start off with no entropy and just the name of the event. */ 198 mtx_assert(&ie->ie_lock, MA_OWNED); 199 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 200 ie->ie_flags &= ~IE_ENTROPY; 201 missed = 0; 202 space = 1; 203 204 /* Run through all the handlers updating values. */ 205 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 206 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 < 207 sizeof(ie->ie_fullname)) { 208 strcat(ie->ie_fullname, " "); 209 strcat(ie->ie_fullname, ih->ih_name); 210 space = 0; 211 } else 212 missed++; 213 if (ih->ih_flags & IH_ENTROPY) 214 ie->ie_flags |= IE_ENTROPY; 215 } 216 217 /* 218 * If the handler names were too long, add +'s to indicate missing 219 * names. If we run out of room and still have +'s to add, change 220 * the last character from a + to a *. 221 */ 222 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2]; 223 while (missed-- > 0) { 224 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) { 225 if (*last == '+') { 226 *last = '*'; 227 break; 228 } else 229 *last = '+'; 230 } else if (space) { 231 strcat(ie->ie_fullname, " +"); 232 space = 0; 233 } else 234 strcat(ie->ie_fullname, "+"); 235 } 236 237 /* 238 * If this event has an ithread, update it's priority and 239 * name. 240 */ 241 if (ie->ie_thread != NULL) 242 ithread_update(ie->ie_thread); 243 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname); 244 } 245 246 int 247 intr_event_create(struct intr_event **event, void *source, int flags, int irq, 248 void (*pre_ithread)(void *), void (*post_ithread)(void *), 249 void (*post_filter)(void *), int (*assign_cpu)(void *, u_char), 250 const char *fmt, ...) 251 { 252 struct intr_event *ie; 253 va_list ap; 254 255 /* The only valid flag during creation is IE_SOFT. */ 256 if ((flags & ~IE_SOFT) != 0) 257 return (EINVAL); 258 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO); 259 ie->ie_source = source; 260 ie->ie_pre_ithread = pre_ithread; 261 ie->ie_post_ithread = post_ithread; 262 ie->ie_post_filter = post_filter; 263 ie->ie_assign_cpu = assign_cpu; 264 ie->ie_flags = flags; 265 ie->ie_irq = irq; 266 ie->ie_cpu = NOCPU; 267 TAILQ_INIT(&ie->ie_handlers); 268 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF); 269 270 va_start(ap, fmt); 271 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap); 272 va_end(ap); 273 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 274 mtx_lock(&event_lock); 275 TAILQ_INSERT_TAIL(&event_list, ie, ie_list); 276 mtx_unlock(&event_lock); 277 if (event != NULL) 278 *event = ie; 279 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name); 280 return (0); 281 } 282 283 /* 284 * Bind an interrupt event to the specified CPU. Note that not all 285 * platforms support binding an interrupt to a CPU. For those 286 * platforms this request will fail. For supported platforms, any 287 * associated ithreads as well as the primary interrupt context will 288 * be bound to the specificed CPU. Using a cpu id of NOCPU unbinds 289 * the interrupt event. 290 */ 291 int 292 intr_event_bind(struct intr_event *ie, u_char cpu) 293 { 294 cpuset_t mask; 295 lwpid_t id; 296 int error; 297 298 /* Need a CPU to bind to. */ 299 if (cpu != NOCPU && CPU_ABSENT(cpu)) 300 return (EINVAL); 301 302 if (ie->ie_assign_cpu == NULL) 303 return (EOPNOTSUPP); 304 305 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR); 306 if (error) 307 return (error); 308 309 /* 310 * If we have any ithreads try to set their mask first to verify 311 * permissions, etc. 312 */ 313 mtx_lock(&ie->ie_lock); 314 if (ie->ie_thread != NULL) { 315 CPU_ZERO(&mask); 316 if (cpu == NOCPU) 317 CPU_COPY(cpuset_root, &mask); 318 else 319 CPU_SET(cpu, &mask); 320 id = ie->ie_thread->it_thread->td_tid; 321 mtx_unlock(&ie->ie_lock); 322 error = cpuset_setthread(id, &mask); 323 if (error) 324 return (error); 325 } else 326 mtx_unlock(&ie->ie_lock); 327 error = ie->ie_assign_cpu(ie->ie_source, cpu); 328 if (error) { 329 mtx_lock(&ie->ie_lock); 330 if (ie->ie_thread != NULL) { 331 CPU_ZERO(&mask); 332 if (ie->ie_cpu == NOCPU) 333 CPU_COPY(cpuset_root, &mask); 334 else 335 CPU_SET(cpu, &mask); 336 id = ie->ie_thread->it_thread->td_tid; 337 mtx_unlock(&ie->ie_lock); 338 (void)cpuset_setthread(id, &mask); 339 } else 340 mtx_unlock(&ie->ie_lock); 341 return (error); 342 } 343 344 mtx_lock(&ie->ie_lock); 345 ie->ie_cpu = cpu; 346 mtx_unlock(&ie->ie_lock); 347 348 return (error); 349 } 350 351 static struct intr_event * 352 intr_lookup(int irq) 353 { 354 struct intr_event *ie; 355 356 mtx_lock(&event_lock); 357 TAILQ_FOREACH(ie, &event_list, ie_list) 358 if (ie->ie_irq == irq && 359 (ie->ie_flags & IE_SOFT) == 0 && 360 TAILQ_FIRST(&ie->ie_handlers) != NULL) 361 break; 362 mtx_unlock(&event_lock); 363 return (ie); 364 } 365 366 int 367 intr_setaffinity(int irq, void *m) 368 { 369 struct intr_event *ie; 370 cpuset_t *mask; 371 u_char cpu; 372 int n; 373 374 mask = m; 375 cpu = NOCPU; 376 /* 377 * If we're setting all cpus we can unbind. Otherwise make sure 378 * only one cpu is in the set. 379 */ 380 if (CPU_CMP(cpuset_root, mask)) { 381 for (n = 0; n < CPU_SETSIZE; n++) { 382 if (!CPU_ISSET(n, mask)) 383 continue; 384 if (cpu != NOCPU) 385 return (EINVAL); 386 cpu = (u_char)n; 387 } 388 } 389 ie = intr_lookup(irq); 390 if (ie == NULL) 391 return (ESRCH); 392 return (intr_event_bind(ie, cpu)); 393 } 394 395 int 396 intr_getaffinity(int irq, void *m) 397 { 398 struct intr_event *ie; 399 cpuset_t *mask; 400 401 mask = m; 402 ie = intr_lookup(irq); 403 if (ie == NULL) 404 return (ESRCH); 405 CPU_ZERO(mask); 406 mtx_lock(&ie->ie_lock); 407 if (ie->ie_cpu == NOCPU) 408 CPU_COPY(cpuset_root, mask); 409 else 410 CPU_SET(ie->ie_cpu, mask); 411 mtx_unlock(&ie->ie_lock); 412 return (0); 413 } 414 415 int 416 intr_event_destroy(struct intr_event *ie) 417 { 418 419 mtx_lock(&event_lock); 420 mtx_lock(&ie->ie_lock); 421 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 422 mtx_unlock(&ie->ie_lock); 423 mtx_unlock(&event_lock); 424 return (EBUSY); 425 } 426 TAILQ_REMOVE(&event_list, ie, ie_list); 427 #ifndef notyet 428 if (ie->ie_thread != NULL) { 429 ithread_destroy(ie->ie_thread); 430 ie->ie_thread = NULL; 431 } 432 #endif 433 mtx_unlock(&ie->ie_lock); 434 mtx_unlock(&event_lock); 435 mtx_destroy(&ie->ie_lock); 436 free(ie, M_ITHREAD); 437 return (0); 438 } 439 440 #ifndef INTR_FILTER 441 static struct intr_thread * 442 ithread_create(const char *name) 443 { 444 struct intr_thread *ithd; 445 struct thread *td; 446 int error; 447 448 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 449 450 error = kproc_kthread_add(ithread_loop, ithd, &intrproc, 451 &td, RFSTOPPED | RFHIGHPID, 452 0, "intr", "%s", name); 453 if (error) 454 panic("kproc_create() failed with %d", error); 455 thread_lock(td); 456 sched_class(td, PRI_ITHD); 457 TD_SET_IWAIT(td); 458 thread_unlock(td); 459 td->td_pflags |= TDP_ITHREAD; 460 ithd->it_thread = td; 461 CTR2(KTR_INTR, "%s: created %s", __func__, name); 462 return (ithd); 463 } 464 #else 465 static struct intr_thread * 466 ithread_create(const char *name, struct intr_handler *ih) 467 { 468 struct intr_thread *ithd; 469 struct thread *td; 470 int error; 471 472 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 473 474 error = kproc_kthread_add(ithread_loop, ih, &intrproc, 475 &td, RFSTOPPED | RFHIGHPID, 476 0, "intr", "%s", name); 477 if (error) 478 panic("kproc_create() failed with %d", error); 479 thread_lock(td); 480 sched_class(td, PRI_ITHD); 481 TD_SET_IWAIT(td); 482 thread_unlock(td); 483 td->td_pflags |= TDP_ITHREAD; 484 ithd->it_thread = td; 485 CTR2(KTR_INTR, "%s: created %s", __func__, name); 486 return (ithd); 487 } 488 #endif 489 490 static void 491 ithread_destroy(struct intr_thread *ithread) 492 { 493 struct thread *td; 494 495 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name); 496 td = ithread->it_thread; 497 thread_lock(td); 498 ithread->it_flags |= IT_DEAD; 499 if (TD_AWAITING_INTR(td)) { 500 TD_CLR_IWAIT(td); 501 sched_add(td, SRQ_INTR); 502 } 503 thread_unlock(td); 504 } 505 506 #ifndef INTR_FILTER 507 int 508 intr_event_add_handler(struct intr_event *ie, const char *name, 509 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 510 enum intr_type flags, void **cookiep) 511 { 512 struct intr_handler *ih, *temp_ih; 513 struct intr_thread *it; 514 515 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 516 return (EINVAL); 517 518 /* Allocate and populate an interrupt handler structure. */ 519 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 520 ih->ih_filter = filter; 521 ih->ih_handler = handler; 522 ih->ih_argument = arg; 523 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 524 ih->ih_event = ie; 525 ih->ih_pri = pri; 526 if (flags & INTR_EXCL) 527 ih->ih_flags = IH_EXCLUSIVE; 528 if (flags & INTR_MPSAFE) 529 ih->ih_flags |= IH_MPSAFE; 530 if (flags & INTR_ENTROPY) 531 ih->ih_flags |= IH_ENTROPY; 532 533 /* We can only have one exclusive handler in a event. */ 534 mtx_lock(&ie->ie_lock); 535 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 536 if ((flags & INTR_EXCL) || 537 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 538 mtx_unlock(&ie->ie_lock); 539 free(ih, M_ITHREAD); 540 return (EINVAL); 541 } 542 } 543 544 /* Add the new handler to the event in priority order. */ 545 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) { 546 if (temp_ih->ih_pri > ih->ih_pri) 547 break; 548 } 549 if (temp_ih == NULL) 550 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next); 551 else 552 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 553 intr_event_update(ie); 554 555 /* Create a thread if we need one. */ 556 while (ie->ie_thread == NULL && handler != NULL) { 557 if (ie->ie_flags & IE_ADDING_THREAD) 558 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 559 else { 560 ie->ie_flags |= IE_ADDING_THREAD; 561 mtx_unlock(&ie->ie_lock); 562 it = ithread_create("intr: newborn"); 563 mtx_lock(&ie->ie_lock); 564 ie->ie_flags &= ~IE_ADDING_THREAD; 565 ie->ie_thread = it; 566 it->it_event = ie; 567 ithread_update(it); 568 wakeup(ie); 569 } 570 } 571 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 572 ie->ie_name); 573 mtx_unlock(&ie->ie_lock); 574 575 if (cookiep != NULL) 576 *cookiep = ih; 577 return (0); 578 } 579 #else 580 int 581 intr_event_add_handler(struct intr_event *ie, const char *name, 582 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 583 enum intr_type flags, void **cookiep) 584 { 585 struct intr_handler *ih, *temp_ih; 586 struct intr_thread *it; 587 588 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 589 return (EINVAL); 590 591 /* Allocate and populate an interrupt handler structure. */ 592 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 593 ih->ih_filter = filter; 594 ih->ih_handler = handler; 595 ih->ih_argument = arg; 596 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 597 ih->ih_event = ie; 598 ih->ih_pri = pri; 599 if (flags & INTR_EXCL) 600 ih->ih_flags = IH_EXCLUSIVE; 601 if (flags & INTR_MPSAFE) 602 ih->ih_flags |= IH_MPSAFE; 603 if (flags & INTR_ENTROPY) 604 ih->ih_flags |= IH_ENTROPY; 605 606 /* We can only have one exclusive handler in a event. */ 607 mtx_lock(&ie->ie_lock); 608 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 609 if ((flags & INTR_EXCL) || 610 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 611 mtx_unlock(&ie->ie_lock); 612 free(ih, M_ITHREAD); 613 return (EINVAL); 614 } 615 } 616 617 /* Add the new handler to the event in priority order. */ 618 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) { 619 if (temp_ih->ih_pri > ih->ih_pri) 620 break; 621 } 622 if (temp_ih == NULL) 623 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next); 624 else 625 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 626 intr_event_update(ie); 627 628 /* For filtered handlers, create a private ithread to run on. */ 629 if (filter != NULL && handler != NULL) { 630 mtx_unlock(&ie->ie_lock); 631 it = ithread_create("intr: newborn", ih); 632 mtx_lock(&ie->ie_lock); 633 it->it_event = ie; 634 ih->ih_thread = it; 635 ithread_update(it); // XXX - do we really need this?!?!? 636 } else { /* Create the global per-event thread if we need one. */ 637 while (ie->ie_thread == NULL && handler != NULL) { 638 if (ie->ie_flags & IE_ADDING_THREAD) 639 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 640 else { 641 ie->ie_flags |= IE_ADDING_THREAD; 642 mtx_unlock(&ie->ie_lock); 643 it = ithread_create("intr: newborn", ih); 644 mtx_lock(&ie->ie_lock); 645 ie->ie_flags &= ~IE_ADDING_THREAD; 646 ie->ie_thread = it; 647 it->it_event = ie; 648 ithread_update(it); 649 wakeup(ie); 650 } 651 } 652 } 653 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 654 ie->ie_name); 655 mtx_unlock(&ie->ie_lock); 656 657 if (cookiep != NULL) 658 *cookiep = ih; 659 return (0); 660 } 661 #endif 662 663 /* 664 * Append a description preceded by a ':' to the name of the specified 665 * interrupt handler. 666 */ 667 int 668 intr_event_describe_handler(struct intr_event *ie, void *cookie, 669 const char *descr) 670 { 671 struct intr_handler *ih; 672 size_t space; 673 char *start; 674 675 mtx_lock(&ie->ie_lock); 676 #ifdef INVARIANTS 677 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 678 if (ih == cookie) 679 break; 680 } 681 if (ih == NULL) { 682 mtx_unlock(&ie->ie_lock); 683 panic("handler %p not found in interrupt event %p", cookie, ie); 684 } 685 #endif 686 ih = cookie; 687 688 /* 689 * Look for an existing description by checking for an 690 * existing ":". This assumes device names do not include 691 * colons. If one is found, prepare to insert the new 692 * description at that point. If one is not found, find the 693 * end of the name to use as the insertion point. 694 */ 695 start = index(ih->ih_name, ':'); 696 if (start == NULL) 697 start = index(ih->ih_name, 0); 698 699 /* 700 * See if there is enough remaining room in the string for the 701 * description + ":". The "- 1" leaves room for the trailing 702 * '\0'. The "+ 1" accounts for the colon. 703 */ 704 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1; 705 if (strlen(descr) + 1 > space) { 706 mtx_unlock(&ie->ie_lock); 707 return (ENOSPC); 708 } 709 710 /* Append a colon followed by the description. */ 711 *start = ':'; 712 strcpy(start + 1, descr); 713 intr_event_update(ie); 714 mtx_unlock(&ie->ie_lock); 715 return (0); 716 } 717 718 /* 719 * Return the ie_source field from the intr_event an intr_handler is 720 * associated with. 721 */ 722 void * 723 intr_handler_source(void *cookie) 724 { 725 struct intr_handler *ih; 726 struct intr_event *ie; 727 728 ih = (struct intr_handler *)cookie; 729 if (ih == NULL) 730 return (NULL); 731 ie = ih->ih_event; 732 KASSERT(ie != NULL, 733 ("interrupt handler \"%s\" has a NULL interrupt event", 734 ih->ih_name)); 735 return (ie->ie_source); 736 } 737 738 #ifndef INTR_FILTER 739 int 740 intr_event_remove_handler(void *cookie) 741 { 742 struct intr_handler *handler = (struct intr_handler *)cookie; 743 struct intr_event *ie; 744 #ifdef INVARIANTS 745 struct intr_handler *ih; 746 #endif 747 #ifdef notyet 748 int dead; 749 #endif 750 751 if (handler == NULL) 752 return (EINVAL); 753 ie = handler->ih_event; 754 KASSERT(ie != NULL, 755 ("interrupt handler \"%s\" has a NULL interrupt event", 756 handler->ih_name)); 757 mtx_lock(&ie->ie_lock); 758 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 759 ie->ie_name); 760 #ifdef INVARIANTS 761 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 762 if (ih == handler) 763 goto ok; 764 mtx_unlock(&ie->ie_lock); 765 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"", 766 ih->ih_name, ie->ie_name); 767 ok: 768 #endif 769 /* 770 * If there is no ithread, then just remove the handler and return. 771 * XXX: Note that an INTR_FAST handler might be running on another 772 * CPU! 773 */ 774 if (ie->ie_thread == NULL) { 775 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 776 mtx_unlock(&ie->ie_lock); 777 free(handler, M_ITHREAD); 778 return (0); 779 } 780 781 /* 782 * If the interrupt thread is already running, then just mark this 783 * handler as being dead and let the ithread do the actual removal. 784 * 785 * During a cold boot while cold is set, msleep() does not sleep, 786 * so we have to remove the handler here rather than letting the 787 * thread do it. 788 */ 789 thread_lock(ie->ie_thread->it_thread); 790 if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) { 791 handler->ih_flags |= IH_DEAD; 792 793 /* 794 * Ensure that the thread will process the handler list 795 * again and remove this handler if it has already passed 796 * it on the list. 797 */ 798 ie->ie_thread->it_need = 1; 799 } else 800 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 801 thread_unlock(ie->ie_thread->it_thread); 802 while (handler->ih_flags & IH_DEAD) 803 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 804 intr_event_update(ie); 805 #ifdef notyet 806 /* 807 * XXX: This could be bad in the case of ppbus(8). Also, I think 808 * this could lead to races of stale data when servicing an 809 * interrupt. 810 */ 811 dead = 1; 812 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 813 if (!(ih->ih_flags & IH_FAST)) { 814 dead = 0; 815 break; 816 } 817 } 818 if (dead) { 819 ithread_destroy(ie->ie_thread); 820 ie->ie_thread = NULL; 821 } 822 #endif 823 mtx_unlock(&ie->ie_lock); 824 free(handler, M_ITHREAD); 825 return (0); 826 } 827 828 static int 829 intr_event_schedule_thread(struct intr_event *ie) 830 { 831 struct intr_entropy entropy; 832 struct intr_thread *it; 833 struct thread *td; 834 struct thread *ctd; 835 struct proc *p; 836 837 /* 838 * If no ithread or no handlers, then we have a stray interrupt. 839 */ 840 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || 841 ie->ie_thread == NULL) 842 return (EINVAL); 843 844 ctd = curthread; 845 it = ie->ie_thread; 846 td = it->it_thread; 847 p = td->td_proc; 848 849 /* 850 * If any of the handlers for this ithread claim to be good 851 * sources of entropy, then gather some. 852 */ 853 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) { 854 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__, 855 p->p_pid, td->td_name); 856 entropy.event = (uintptr_t)ie; 857 entropy.td = ctd; 858 random_harvest(&entropy, sizeof(entropy), 2, 0, 859 RANDOM_INTERRUPT); 860 } 861 862 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name)); 863 864 /* 865 * Set it_need to tell the thread to keep running if it is already 866 * running. Then, lock the thread and see if we actually need to 867 * put it on the runqueue. 868 */ 869 it->it_need = 1; 870 thread_lock(td); 871 if (TD_AWAITING_INTR(td)) { 872 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid, 873 td->td_name); 874 TD_CLR_IWAIT(td); 875 sched_add(td, SRQ_INTR); 876 } else { 877 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 878 __func__, p->p_pid, td->td_name, it->it_need, td->td_state); 879 } 880 thread_unlock(td); 881 882 return (0); 883 } 884 #else 885 int 886 intr_event_remove_handler(void *cookie) 887 { 888 struct intr_handler *handler = (struct intr_handler *)cookie; 889 struct intr_event *ie; 890 struct intr_thread *it; 891 #ifdef INVARIANTS 892 struct intr_handler *ih; 893 #endif 894 #ifdef notyet 895 int dead; 896 #endif 897 898 if (handler == NULL) 899 return (EINVAL); 900 ie = handler->ih_event; 901 KASSERT(ie != NULL, 902 ("interrupt handler \"%s\" has a NULL interrupt event", 903 handler->ih_name)); 904 mtx_lock(&ie->ie_lock); 905 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 906 ie->ie_name); 907 #ifdef INVARIANTS 908 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 909 if (ih == handler) 910 goto ok; 911 mtx_unlock(&ie->ie_lock); 912 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"", 913 ih->ih_name, ie->ie_name); 914 ok: 915 #endif 916 /* 917 * If there are no ithreads (per event and per handler), then 918 * just remove the handler and return. 919 * XXX: Note that an INTR_FAST handler might be running on another CPU! 920 */ 921 if (ie->ie_thread == NULL && handler->ih_thread == NULL) { 922 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 923 mtx_unlock(&ie->ie_lock); 924 free(handler, M_ITHREAD); 925 return (0); 926 } 927 928 /* Private or global ithread? */ 929 it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread; 930 /* 931 * If the interrupt thread is already running, then just mark this 932 * handler as being dead and let the ithread do the actual removal. 933 * 934 * During a cold boot while cold is set, msleep() does not sleep, 935 * so we have to remove the handler here rather than letting the 936 * thread do it. 937 */ 938 thread_lock(it->it_thread); 939 if (!TD_AWAITING_INTR(it->it_thread) && !cold) { 940 handler->ih_flags |= IH_DEAD; 941 942 /* 943 * Ensure that the thread will process the handler list 944 * again and remove this handler if it has already passed 945 * it on the list. 946 */ 947 it->it_need = 1; 948 } else 949 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 950 thread_unlock(it->it_thread); 951 while (handler->ih_flags & IH_DEAD) 952 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 953 /* 954 * At this point, the handler has been disconnected from the event, 955 * so we can kill the private ithread if any. 956 */ 957 if (handler->ih_thread) { 958 ithread_destroy(handler->ih_thread); 959 handler->ih_thread = NULL; 960 } 961 intr_event_update(ie); 962 #ifdef notyet 963 /* 964 * XXX: This could be bad in the case of ppbus(8). Also, I think 965 * this could lead to races of stale data when servicing an 966 * interrupt. 967 */ 968 dead = 1; 969 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 970 if (handler != NULL) { 971 dead = 0; 972 break; 973 } 974 } 975 if (dead) { 976 ithread_destroy(ie->ie_thread); 977 ie->ie_thread = NULL; 978 } 979 #endif 980 mtx_unlock(&ie->ie_lock); 981 free(handler, M_ITHREAD); 982 return (0); 983 } 984 985 static int 986 intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it) 987 { 988 struct intr_entropy entropy; 989 struct thread *td; 990 struct thread *ctd; 991 struct proc *p; 992 993 /* 994 * If no ithread or no handlers, then we have a stray interrupt. 995 */ 996 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || it == NULL) 997 return (EINVAL); 998 999 ctd = curthread; 1000 td = it->it_thread; 1001 p = td->td_proc; 1002 1003 /* 1004 * If any of the handlers for this ithread claim to be good 1005 * sources of entropy, then gather some. 1006 */ 1007 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) { 1008 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__, 1009 p->p_pid, td->td_name); 1010 entropy.event = (uintptr_t)ie; 1011 entropy.td = ctd; 1012 random_harvest(&entropy, sizeof(entropy), 2, 0, 1013 RANDOM_INTERRUPT); 1014 } 1015 1016 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name)); 1017 1018 /* 1019 * Set it_need to tell the thread to keep running if it is already 1020 * running. Then, lock the thread and see if we actually need to 1021 * put it on the runqueue. 1022 */ 1023 it->it_need = 1; 1024 thread_lock(td); 1025 if (TD_AWAITING_INTR(td)) { 1026 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid, 1027 td->td_name); 1028 TD_CLR_IWAIT(td); 1029 sched_add(td, SRQ_INTR); 1030 } else { 1031 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 1032 __func__, p->p_pid, td->td_name, it->it_need, td->td_state); 1033 } 1034 thread_unlock(td); 1035 1036 return (0); 1037 } 1038 #endif 1039 1040 /* 1041 * Allow interrupt event binding for software interrupt handlers -- a no-op, 1042 * since interrupts are generated in software rather than being directed by 1043 * a PIC. 1044 */ 1045 static int 1046 swi_assign_cpu(void *arg, u_char cpu) 1047 { 1048 1049 return (0); 1050 } 1051 1052 /* 1053 * Add a software interrupt handler to a specified event. If a given event 1054 * is not specified, then a new event is created. 1055 */ 1056 int 1057 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler, 1058 void *arg, int pri, enum intr_type flags, void **cookiep) 1059 { 1060 struct thread *td; 1061 struct intr_event *ie; 1062 int error; 1063 1064 if (flags & INTR_ENTROPY) 1065 return (EINVAL); 1066 1067 ie = (eventp != NULL) ? *eventp : NULL; 1068 1069 if (ie != NULL) { 1070 if (!(ie->ie_flags & IE_SOFT)) 1071 return (EINVAL); 1072 } else { 1073 error = intr_event_create(&ie, NULL, IE_SOFT, 0, 1074 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri); 1075 if (error) 1076 return (error); 1077 if (eventp != NULL) 1078 *eventp = ie; 1079 } 1080 error = intr_event_add_handler(ie, name, NULL, handler, arg, 1081 PI_SWI(pri), flags, cookiep); 1082 if (error) 1083 return (error); 1084 if (pri == SWI_CLOCK) { 1085 td = ie->ie_thread->it_thread; 1086 thread_lock(td); 1087 td->td_flags |= TDF_NOLOAD; 1088 thread_unlock(td); 1089 } 1090 return (0); 1091 } 1092 1093 /* 1094 * Schedule a software interrupt thread. 1095 */ 1096 void 1097 swi_sched(void *cookie, int flags) 1098 { 1099 struct intr_handler *ih = (struct intr_handler *)cookie; 1100 struct intr_event *ie = ih->ih_event; 1101 int error; 1102 1103 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name, 1104 ih->ih_need); 1105 1106 /* 1107 * Set ih_need for this handler so that if the ithread is already 1108 * running it will execute this handler on the next pass. Otherwise, 1109 * it will execute it the next time it runs. 1110 */ 1111 atomic_store_rel_int(&ih->ih_need, 1); 1112 1113 if (!(flags & SWI_DELAY)) { 1114 PCPU_INC(cnt.v_soft); 1115 #ifdef INTR_FILTER 1116 error = intr_event_schedule_thread(ie, ie->ie_thread); 1117 #else 1118 error = intr_event_schedule_thread(ie); 1119 #endif 1120 KASSERT(error == 0, ("stray software interrupt")); 1121 } 1122 } 1123 1124 /* 1125 * Remove a software interrupt handler. Currently this code does not 1126 * remove the associated interrupt event if it becomes empty. Calling code 1127 * may do so manually via intr_event_destroy(), but that's not really 1128 * an optimal interface. 1129 */ 1130 int 1131 swi_remove(void *cookie) 1132 { 1133 1134 return (intr_event_remove_handler(cookie)); 1135 } 1136 1137 #ifdef INTR_FILTER 1138 static void 1139 priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih) 1140 { 1141 struct intr_event *ie; 1142 1143 ie = ih->ih_event; 1144 /* 1145 * If this handler is marked for death, remove it from 1146 * the list of handlers and wake up the sleeper. 1147 */ 1148 if (ih->ih_flags & IH_DEAD) { 1149 mtx_lock(&ie->ie_lock); 1150 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next); 1151 ih->ih_flags &= ~IH_DEAD; 1152 wakeup(ih); 1153 mtx_unlock(&ie->ie_lock); 1154 return; 1155 } 1156 1157 /* Execute this handler. */ 1158 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1159 __func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument, 1160 ih->ih_name, ih->ih_flags); 1161 1162 if (!(ih->ih_flags & IH_MPSAFE)) 1163 mtx_lock(&Giant); 1164 ih->ih_handler(ih->ih_argument); 1165 if (!(ih->ih_flags & IH_MPSAFE)) 1166 mtx_unlock(&Giant); 1167 } 1168 #endif 1169 1170 /* 1171 * This is a public function for use by drivers that mux interrupt 1172 * handlers for child devices from their interrupt handler. 1173 */ 1174 void 1175 intr_event_execute_handlers(struct proc *p, struct intr_event *ie) 1176 { 1177 struct intr_handler *ih, *ihn; 1178 1179 TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) { 1180 /* 1181 * If this handler is marked for death, remove it from 1182 * the list of handlers and wake up the sleeper. 1183 */ 1184 if (ih->ih_flags & IH_DEAD) { 1185 mtx_lock(&ie->ie_lock); 1186 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next); 1187 ih->ih_flags &= ~IH_DEAD; 1188 wakeup(ih); 1189 mtx_unlock(&ie->ie_lock); 1190 continue; 1191 } 1192 1193 /* Skip filter only handlers */ 1194 if (ih->ih_handler == NULL) 1195 continue; 1196 1197 /* 1198 * For software interrupt threads, we only execute 1199 * handlers that have their need flag set. Hardware 1200 * interrupt threads always invoke all of their handlers. 1201 */ 1202 if (ie->ie_flags & IE_SOFT) { 1203 if (!ih->ih_need) 1204 continue; 1205 else 1206 atomic_store_rel_int(&ih->ih_need, 0); 1207 } 1208 1209 /* Execute this handler. */ 1210 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1211 __func__, p->p_pid, (void *)ih->ih_handler, 1212 ih->ih_argument, ih->ih_name, ih->ih_flags); 1213 1214 if (!(ih->ih_flags & IH_MPSAFE)) 1215 mtx_lock(&Giant); 1216 ih->ih_handler(ih->ih_argument); 1217 if (!(ih->ih_flags & IH_MPSAFE)) 1218 mtx_unlock(&Giant); 1219 } 1220 } 1221 1222 static void 1223 ithread_execute_handlers(struct proc *p, struct intr_event *ie) 1224 { 1225 1226 /* Interrupt handlers should not sleep. */ 1227 if (!(ie->ie_flags & IE_SOFT)) 1228 THREAD_NO_SLEEPING(); 1229 intr_event_execute_handlers(p, ie); 1230 if (!(ie->ie_flags & IE_SOFT)) 1231 THREAD_SLEEPING_OK(); 1232 1233 /* 1234 * Interrupt storm handling: 1235 * 1236 * If this interrupt source is currently storming, then throttle 1237 * it to only fire the handler once per clock tick. 1238 * 1239 * If this interrupt source is not currently storming, but the 1240 * number of back to back interrupts exceeds the storm threshold, 1241 * then enter storming mode. 1242 */ 1243 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold && 1244 !(ie->ie_flags & IE_SOFT)) { 1245 /* Report the message only once every second. */ 1246 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) { 1247 printf( 1248 "interrupt storm detected on \"%s\"; throttling interrupt source\n", 1249 ie->ie_name); 1250 } 1251 pause("istorm", 1); 1252 } else 1253 ie->ie_count++; 1254 1255 /* 1256 * Now that all the handlers have had a chance to run, reenable 1257 * the interrupt source. 1258 */ 1259 if (ie->ie_post_ithread != NULL) 1260 ie->ie_post_ithread(ie->ie_source); 1261 } 1262 1263 #ifndef INTR_FILTER 1264 /* 1265 * This is the main code for interrupt threads. 1266 */ 1267 static void 1268 ithread_loop(void *arg) 1269 { 1270 struct intr_thread *ithd; 1271 struct intr_event *ie; 1272 struct thread *td; 1273 struct proc *p; 1274 1275 td = curthread; 1276 p = td->td_proc; 1277 ithd = (struct intr_thread *)arg; 1278 KASSERT(ithd->it_thread == td, 1279 ("%s: ithread and proc linkage out of sync", __func__)); 1280 ie = ithd->it_event; 1281 ie->ie_count = 0; 1282 1283 /* 1284 * As long as we have interrupts outstanding, go through the 1285 * list of handlers, giving each one a go at it. 1286 */ 1287 for (;;) { 1288 /* 1289 * If we are an orphaned thread, then just die. 1290 */ 1291 if (ithd->it_flags & IT_DEAD) { 1292 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1293 p->p_pid, td->td_name); 1294 free(ithd, M_ITHREAD); 1295 kthread_exit(); 1296 } 1297 1298 /* 1299 * Service interrupts. If another interrupt arrives while 1300 * we are running, it will set it_need to note that we 1301 * should make another pass. 1302 */ 1303 while (ithd->it_need) { 1304 /* 1305 * This might need a full read and write barrier 1306 * to make sure that this write posts before any 1307 * of the memory or device accesses in the 1308 * handlers. 1309 */ 1310 atomic_store_rel_int(&ithd->it_need, 0); 1311 ithread_execute_handlers(p, ie); 1312 } 1313 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1314 mtx_assert(&Giant, MA_NOTOWNED); 1315 1316 /* 1317 * Processed all our interrupts. Now get the sched 1318 * lock. This may take a while and it_need may get 1319 * set again, so we have to check it again. 1320 */ 1321 thread_lock(td); 1322 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) { 1323 TD_SET_IWAIT(td); 1324 ie->ie_count = 0; 1325 mi_switch(SW_VOL | SWT_IWAIT, NULL); 1326 } 1327 thread_unlock(td); 1328 } 1329 } 1330 1331 /* 1332 * Main interrupt handling body. 1333 * 1334 * Input: 1335 * o ie: the event connected to this interrupt. 1336 * o frame: some archs (i.e. i386) pass a frame to some. 1337 * handlers as their main argument. 1338 * Return value: 1339 * o 0: everything ok. 1340 * o EINVAL: stray interrupt. 1341 */ 1342 int 1343 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1344 { 1345 struct intr_handler *ih; 1346 struct thread *td; 1347 int error, ret, thread; 1348 1349 td = curthread; 1350 1351 /* An interrupt with no event or handlers is a stray interrupt. */ 1352 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers)) 1353 return (EINVAL); 1354 1355 /* 1356 * Execute fast interrupt handlers directly. 1357 * To support clock handlers, if a handler registers 1358 * with a NULL argument, then we pass it a pointer to 1359 * a trapframe as its argument. 1360 */ 1361 td->td_intr_nesting_level++; 1362 thread = 0; 1363 ret = 0; 1364 critical_enter(); 1365 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1366 if (ih->ih_filter == NULL) { 1367 thread = 1; 1368 continue; 1369 } 1370 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__, 1371 ih->ih_filter, ih->ih_argument == NULL ? frame : 1372 ih->ih_argument, ih->ih_name); 1373 if (ih->ih_argument == NULL) 1374 ret = ih->ih_filter(frame); 1375 else 1376 ret = ih->ih_filter(ih->ih_argument); 1377 KASSERT(ret == FILTER_STRAY || 1378 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1379 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1380 ("%s: incorrect return value %#x from %s", __func__, ret, 1381 ih->ih_name)); 1382 1383 /* 1384 * Wrapper handler special handling: 1385 * 1386 * in some particular cases (like pccard and pccbb), 1387 * the _real_ device handler is wrapped in a couple of 1388 * functions - a filter wrapper and an ithread wrapper. 1389 * In this case (and just in this case), the filter wrapper 1390 * could ask the system to schedule the ithread and mask 1391 * the interrupt source if the wrapped handler is composed 1392 * of just an ithread handler. 1393 * 1394 * TODO: write a generic wrapper to avoid people rolling 1395 * their own 1396 */ 1397 if (!thread) { 1398 if (ret == FILTER_SCHEDULE_THREAD) 1399 thread = 1; 1400 } 1401 } 1402 1403 if (thread) { 1404 if (ie->ie_pre_ithread != NULL) 1405 ie->ie_pre_ithread(ie->ie_source); 1406 } else { 1407 if (ie->ie_post_filter != NULL) 1408 ie->ie_post_filter(ie->ie_source); 1409 } 1410 1411 /* Schedule the ithread if needed. */ 1412 if (thread) { 1413 error = intr_event_schedule_thread(ie); 1414 #ifndef XEN 1415 KASSERT(error == 0, ("bad stray interrupt")); 1416 #else 1417 if (error != 0) 1418 log(LOG_WARNING, "bad stray interrupt"); 1419 #endif 1420 } 1421 critical_exit(); 1422 td->td_intr_nesting_level--; 1423 return (0); 1424 } 1425 #else 1426 /* 1427 * This is the main code for interrupt threads. 1428 */ 1429 static void 1430 ithread_loop(void *arg) 1431 { 1432 struct intr_thread *ithd; 1433 struct intr_handler *ih; 1434 struct intr_event *ie; 1435 struct thread *td; 1436 struct proc *p; 1437 int priv; 1438 1439 td = curthread; 1440 p = td->td_proc; 1441 ih = (struct intr_handler *)arg; 1442 priv = (ih->ih_thread != NULL) ? 1 : 0; 1443 ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread; 1444 KASSERT(ithd->it_thread == td, 1445 ("%s: ithread and proc linkage out of sync", __func__)); 1446 ie = ithd->it_event; 1447 ie->ie_count = 0; 1448 1449 /* 1450 * As long as we have interrupts outstanding, go through the 1451 * list of handlers, giving each one a go at it. 1452 */ 1453 for (;;) { 1454 /* 1455 * If we are an orphaned thread, then just die. 1456 */ 1457 if (ithd->it_flags & IT_DEAD) { 1458 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1459 p->p_pid, td->td_name); 1460 free(ithd, M_ITHREAD); 1461 kthread_exit(); 1462 } 1463 1464 /* 1465 * Service interrupts. If another interrupt arrives while 1466 * we are running, it will set it_need to note that we 1467 * should make another pass. 1468 */ 1469 while (ithd->it_need) { 1470 /* 1471 * This might need a full read and write barrier 1472 * to make sure that this write posts before any 1473 * of the memory or device accesses in the 1474 * handlers. 1475 */ 1476 atomic_store_rel_int(&ithd->it_need, 0); 1477 if (priv) 1478 priv_ithread_execute_handler(p, ih); 1479 else 1480 ithread_execute_handlers(p, ie); 1481 } 1482 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1483 mtx_assert(&Giant, MA_NOTOWNED); 1484 1485 /* 1486 * Processed all our interrupts. Now get the sched 1487 * lock. This may take a while and it_need may get 1488 * set again, so we have to check it again. 1489 */ 1490 thread_lock(td); 1491 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) { 1492 TD_SET_IWAIT(td); 1493 ie->ie_count = 0; 1494 mi_switch(SW_VOL | SWT_IWAIT, NULL); 1495 } 1496 thread_unlock(td); 1497 } 1498 } 1499 1500 /* 1501 * Main loop for interrupt filter. 1502 * 1503 * Some architectures (i386, amd64 and arm) require the optional frame 1504 * parameter, and use it as the main argument for fast handler execution 1505 * when ih_argument == NULL. 1506 * 1507 * Return value: 1508 * o FILTER_STRAY: No filter recognized the event, and no 1509 * filter-less handler is registered on this 1510 * line. 1511 * o FILTER_HANDLED: A filter claimed the event and served it. 1512 * o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at 1513 * least one filter-less handler on this line. 1514 * o FILTER_HANDLED | 1515 * FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for 1516 * scheduling the per-handler ithread. 1517 * 1518 * In case an ithread has to be scheduled, in *ithd there will be a 1519 * pointer to a struct intr_thread containing the thread to be 1520 * scheduled. 1521 */ 1522 1523 static int 1524 intr_filter_loop(struct intr_event *ie, struct trapframe *frame, 1525 struct intr_thread **ithd) 1526 { 1527 struct intr_handler *ih; 1528 void *arg; 1529 int ret, thread_only; 1530 1531 ret = 0; 1532 thread_only = 0; 1533 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1534 /* 1535 * Execute fast interrupt handlers directly. 1536 * To support clock handlers, if a handler registers 1537 * with a NULL argument, then we pass it a pointer to 1538 * a trapframe as its argument. 1539 */ 1540 arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument); 1541 1542 CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__, 1543 ih->ih_filter, ih->ih_handler, arg, ih->ih_name); 1544 1545 if (ih->ih_filter != NULL) 1546 ret = ih->ih_filter(arg); 1547 else { 1548 thread_only = 1; 1549 continue; 1550 } 1551 KASSERT(ret == FILTER_STRAY || 1552 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1553 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1554 ("%s: incorrect return value %#x from %s", __func__, ret, 1555 ih->ih_name)); 1556 if (ret & FILTER_STRAY) 1557 continue; 1558 else { 1559 *ithd = ih->ih_thread; 1560 return (ret); 1561 } 1562 } 1563 1564 /* 1565 * No filters handled the interrupt and we have at least 1566 * one handler without a filter. In this case, we schedule 1567 * all of the filter-less handlers to run in the ithread. 1568 */ 1569 if (thread_only) { 1570 *ithd = ie->ie_thread; 1571 return (FILTER_SCHEDULE_THREAD); 1572 } 1573 return (FILTER_STRAY); 1574 } 1575 1576 /* 1577 * Main interrupt handling body. 1578 * 1579 * Input: 1580 * o ie: the event connected to this interrupt. 1581 * o frame: some archs (i.e. i386) pass a frame to some. 1582 * handlers as their main argument. 1583 * Return value: 1584 * o 0: everything ok. 1585 * o EINVAL: stray interrupt. 1586 */ 1587 int 1588 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1589 { 1590 struct intr_thread *ithd; 1591 struct thread *td; 1592 int thread; 1593 1594 ithd = NULL; 1595 td = curthread; 1596 1597 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers)) 1598 return (EINVAL); 1599 1600 td->td_intr_nesting_level++; 1601 thread = 0; 1602 critical_enter(); 1603 thread = intr_filter_loop(ie, frame, &ithd); 1604 if (thread & FILTER_HANDLED) { 1605 if (ie->ie_post_filter != NULL) 1606 ie->ie_post_filter(ie->ie_source); 1607 } else { 1608 if (ie->ie_pre_ithread != NULL) 1609 ie->ie_pre_ithread(ie->ie_source); 1610 } 1611 critical_exit(); 1612 1613 /* Interrupt storm logic */ 1614 if (thread & FILTER_STRAY) { 1615 ie->ie_count++; 1616 if (ie->ie_count < intr_storm_threshold) 1617 printf("Interrupt stray detection not present\n"); 1618 } 1619 1620 /* Schedule an ithread if needed. */ 1621 if (thread & FILTER_SCHEDULE_THREAD) { 1622 if (intr_event_schedule_thread(ie, ithd) != 0) 1623 panic("%s: impossible stray interrupt", __func__); 1624 } 1625 td->td_intr_nesting_level--; 1626 return (0); 1627 } 1628 #endif 1629 1630 #ifdef DDB 1631 /* 1632 * Dump details about an interrupt handler 1633 */ 1634 static void 1635 db_dump_intrhand(struct intr_handler *ih) 1636 { 1637 int comma; 1638 1639 db_printf("\t%-10s ", ih->ih_name); 1640 switch (ih->ih_pri) { 1641 case PI_REALTIME: 1642 db_printf("CLK "); 1643 break; 1644 case PI_AV: 1645 db_printf("AV "); 1646 break; 1647 case PI_TTY: 1648 db_printf("TTY "); 1649 break; 1650 case PI_NET: 1651 db_printf("NET "); 1652 break; 1653 case PI_DISK: 1654 db_printf("DISK"); 1655 break; 1656 case PI_DULL: 1657 db_printf("DULL"); 1658 break; 1659 default: 1660 if (ih->ih_pri >= PI_SOFT) 1661 db_printf("SWI "); 1662 else 1663 db_printf("%4u", ih->ih_pri); 1664 break; 1665 } 1666 db_printf(" "); 1667 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC); 1668 db_printf("(%p)", ih->ih_argument); 1669 if (ih->ih_need || 1670 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD | 1671 IH_MPSAFE)) != 0) { 1672 db_printf(" {"); 1673 comma = 0; 1674 if (ih->ih_flags & IH_EXCLUSIVE) { 1675 if (comma) 1676 db_printf(", "); 1677 db_printf("EXCL"); 1678 comma = 1; 1679 } 1680 if (ih->ih_flags & IH_ENTROPY) { 1681 if (comma) 1682 db_printf(", "); 1683 db_printf("ENTROPY"); 1684 comma = 1; 1685 } 1686 if (ih->ih_flags & IH_DEAD) { 1687 if (comma) 1688 db_printf(", "); 1689 db_printf("DEAD"); 1690 comma = 1; 1691 } 1692 if (ih->ih_flags & IH_MPSAFE) { 1693 if (comma) 1694 db_printf(", "); 1695 db_printf("MPSAFE"); 1696 comma = 1; 1697 } 1698 if (ih->ih_need) { 1699 if (comma) 1700 db_printf(", "); 1701 db_printf("NEED"); 1702 } 1703 db_printf("}"); 1704 } 1705 db_printf("\n"); 1706 } 1707 1708 /* 1709 * Dump details about a event. 1710 */ 1711 void 1712 db_dump_intr_event(struct intr_event *ie, int handlers) 1713 { 1714 struct intr_handler *ih; 1715 struct intr_thread *it; 1716 int comma; 1717 1718 db_printf("%s ", ie->ie_fullname); 1719 it = ie->ie_thread; 1720 if (it != NULL) 1721 db_printf("(pid %d)", it->it_thread->td_proc->p_pid); 1722 else 1723 db_printf("(no thread)"); 1724 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 || 1725 (it != NULL && it->it_need)) { 1726 db_printf(" {"); 1727 comma = 0; 1728 if (ie->ie_flags & IE_SOFT) { 1729 db_printf("SOFT"); 1730 comma = 1; 1731 } 1732 if (ie->ie_flags & IE_ENTROPY) { 1733 if (comma) 1734 db_printf(", "); 1735 db_printf("ENTROPY"); 1736 comma = 1; 1737 } 1738 if (ie->ie_flags & IE_ADDING_THREAD) { 1739 if (comma) 1740 db_printf(", "); 1741 db_printf("ADDING_THREAD"); 1742 comma = 1; 1743 } 1744 if (it != NULL && it->it_need) { 1745 if (comma) 1746 db_printf(", "); 1747 db_printf("NEED"); 1748 } 1749 db_printf("}"); 1750 } 1751 db_printf("\n"); 1752 1753 if (handlers) 1754 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 1755 db_dump_intrhand(ih); 1756 } 1757 1758 /* 1759 * Dump data about interrupt handlers 1760 */ 1761 DB_SHOW_COMMAND(intr, db_show_intr) 1762 { 1763 struct intr_event *ie; 1764 int all, verbose; 1765 1766 verbose = index(modif, 'v') != NULL; 1767 all = index(modif, 'a') != NULL; 1768 TAILQ_FOREACH(ie, &event_list, ie_list) { 1769 if (!all && TAILQ_EMPTY(&ie->ie_handlers)) 1770 continue; 1771 db_dump_intr_event(ie, verbose); 1772 if (db_pager_quit) 1773 break; 1774 } 1775 } 1776 #endif /* DDB */ 1777 1778 /* 1779 * Start standard software interrupt threads 1780 */ 1781 static void 1782 start_softintr(void *dummy) 1783 { 1784 1785 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih)) 1786 panic("died while creating vm swi ithread"); 1787 } 1788 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, 1789 NULL); 1790 1791 /* 1792 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. 1793 * The data for this machine dependent, and the declarations are in machine 1794 * dependent code. The layout of intrnames and intrcnt however is machine 1795 * independent. 1796 * 1797 * We do not know the length of intrcnt and intrnames at compile time, so 1798 * calculate things at run time. 1799 */ 1800 static int 1801 sysctl_intrnames(SYSCTL_HANDLER_ARGS) 1802 { 1803 return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames, 1804 req)); 1805 } 1806 1807 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD, 1808 NULL, 0, sysctl_intrnames, "", "Interrupt Names"); 1809 1810 static int 1811 sysctl_intrcnt(SYSCTL_HANDLER_ARGS) 1812 { 1813 return (sysctl_handle_opaque(oidp, intrcnt, 1814 (char *)eintrcnt - (char *)intrcnt, req)); 1815 } 1816 1817 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD, 1818 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts"); 1819 1820 #ifdef DDB 1821 /* 1822 * DDB command to dump the interrupt statistics. 1823 */ 1824 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt) 1825 { 1826 u_long *i; 1827 char *cp; 1828 1829 cp = intrnames; 1830 for (i = intrcnt; i != eintrcnt && !db_pager_quit; i++) { 1831 if (*cp == '\0') 1832 break; 1833 if (*i != 0) 1834 db_printf("%s\t%lu\n", cp, *i); 1835 cp += strlen(cp) + 1; 1836 } 1837 } 1838 #endif
Cache object: b6f8dce33e5dc76e15162e899593ac6d
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