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("$FreeBSD$"); 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 #ifdef KTR 183 sched_clear_tdname(td); 184 #endif 185 thread_lock(td); 186 sched_prio(td, pri); 187 thread_unlock(td); 188 } 189 190 /* 191 * Regenerate the full name of an interrupt event and update its priority. 192 */ 193 static void 194 intr_event_update(struct intr_event *ie) 195 { 196 struct intr_handler *ih; 197 char *last; 198 int missed, space; 199 200 /* Start off with no entropy and just the name of the event. */ 201 mtx_assert(&ie->ie_lock, MA_OWNED); 202 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 203 ie->ie_flags &= ~IE_ENTROPY; 204 missed = 0; 205 space = 1; 206 207 /* Run through all the handlers updating values. */ 208 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 209 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 < 210 sizeof(ie->ie_fullname)) { 211 strcat(ie->ie_fullname, " "); 212 strcat(ie->ie_fullname, ih->ih_name); 213 space = 0; 214 } else 215 missed++; 216 if (ih->ih_flags & IH_ENTROPY) 217 ie->ie_flags |= IE_ENTROPY; 218 } 219 220 /* 221 * If the handler names were too long, add +'s to indicate missing 222 * names. If we run out of room and still have +'s to add, change 223 * the last character from a + to a *. 224 */ 225 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2]; 226 while (missed-- > 0) { 227 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) { 228 if (*last == '+') { 229 *last = '*'; 230 break; 231 } else 232 *last = '+'; 233 } else if (space) { 234 strcat(ie->ie_fullname, " +"); 235 space = 0; 236 } else 237 strcat(ie->ie_fullname, "+"); 238 } 239 240 /* 241 * If this event has an ithread, update it's priority and 242 * name. 243 */ 244 if (ie->ie_thread != NULL) 245 ithread_update(ie->ie_thread); 246 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname); 247 } 248 249 int 250 intr_event_create(struct intr_event **event, void *source, int flags, int irq, 251 void (*pre_ithread)(void *), void (*post_ithread)(void *), 252 void (*post_filter)(void *), int (*assign_cpu)(void *, u_char), 253 const char *fmt, ...) 254 { 255 struct intr_event *ie; 256 va_list ap; 257 258 /* The only valid flag during creation is IE_SOFT. */ 259 if ((flags & ~IE_SOFT) != 0) 260 return (EINVAL); 261 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO); 262 ie->ie_source = source; 263 ie->ie_pre_ithread = pre_ithread; 264 ie->ie_post_ithread = post_ithread; 265 ie->ie_post_filter = post_filter; 266 ie->ie_assign_cpu = assign_cpu; 267 ie->ie_flags = flags; 268 ie->ie_irq = irq; 269 ie->ie_cpu = NOCPU; 270 TAILQ_INIT(&ie->ie_handlers); 271 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF); 272 273 va_start(ap, fmt); 274 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap); 275 va_end(ap); 276 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 277 mtx_lock(&event_lock); 278 TAILQ_INSERT_TAIL(&event_list, ie, ie_list); 279 mtx_unlock(&event_lock); 280 if (event != NULL) 281 *event = ie; 282 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name); 283 return (0); 284 } 285 286 /* 287 * Bind an interrupt event to the specified CPU. Note that not all 288 * platforms support binding an interrupt to a CPU. For those 289 * platforms this request will fail. For supported platforms, any 290 * associated ithreads as well as the primary interrupt context will 291 * be bound to the specificed CPU. Using a cpu id of NOCPU unbinds 292 * the interrupt event. 293 */ 294 int 295 intr_event_bind(struct intr_event *ie, u_char cpu) 296 { 297 cpuset_t mask; 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 CPU_ZERO(&mask); 319 if (cpu == NOCPU) 320 CPU_COPY(cpuset_root, &mask); 321 else 322 CPU_SET(cpu, &mask); 323 id = ie->ie_thread->it_thread->td_tid; 324 mtx_unlock(&ie->ie_lock); 325 error = cpuset_setthread(id, &mask); 326 if (error) 327 return (error); 328 } else 329 mtx_unlock(&ie->ie_lock); 330 error = ie->ie_assign_cpu(ie->ie_source, cpu); 331 if (error) { 332 mtx_lock(&ie->ie_lock); 333 if (ie->ie_thread != NULL) { 334 CPU_ZERO(&mask); 335 if (ie->ie_cpu == NOCPU) 336 CPU_COPY(cpuset_root, &mask); 337 else 338 CPU_SET(cpu, &mask); 339 id = ie->ie_thread->it_thread->td_tid; 340 mtx_unlock(&ie->ie_lock); 341 (void)cpuset_setthread(id, &mask); 342 } else 343 mtx_unlock(&ie->ie_lock); 344 return (error); 345 } 346 347 mtx_lock(&ie->ie_lock); 348 ie->ie_cpu = cpu; 349 mtx_unlock(&ie->ie_lock); 350 351 return (error); 352 } 353 354 static struct intr_event * 355 intr_lookup(int irq) 356 { 357 struct intr_event *ie; 358 359 mtx_lock(&event_lock); 360 TAILQ_FOREACH(ie, &event_list, ie_list) 361 if (ie->ie_irq == irq && 362 (ie->ie_flags & IE_SOFT) == 0 && 363 TAILQ_FIRST(&ie->ie_handlers) != NULL) 364 break; 365 mtx_unlock(&event_lock); 366 return (ie); 367 } 368 369 int 370 intr_setaffinity(int irq, void *m) 371 { 372 struct intr_event *ie; 373 cpuset_t *mask; 374 u_char cpu; 375 int n; 376 377 mask = m; 378 cpu = NOCPU; 379 /* 380 * If we're setting all cpus we can unbind. Otherwise make sure 381 * only one cpu is in the set. 382 */ 383 if (CPU_CMP(cpuset_root, mask)) { 384 for (n = 0; n < CPU_SETSIZE; n++) { 385 if (!CPU_ISSET(n, mask)) 386 continue; 387 if (cpu != NOCPU) 388 return (EINVAL); 389 cpu = (u_char)n; 390 } 391 } 392 ie = intr_lookup(irq); 393 if (ie == NULL) 394 return (ESRCH); 395 return (intr_event_bind(ie, cpu)); 396 } 397 398 int 399 intr_getaffinity(int irq, void *m) 400 { 401 struct intr_event *ie; 402 cpuset_t *mask; 403 404 mask = m; 405 ie = intr_lookup(irq); 406 if (ie == NULL) 407 return (ESRCH); 408 CPU_ZERO(mask); 409 mtx_lock(&ie->ie_lock); 410 if (ie->ie_cpu == NOCPU) 411 CPU_COPY(cpuset_root, mask); 412 else 413 CPU_SET(ie->ie_cpu, mask); 414 mtx_unlock(&ie->ie_lock); 415 return (0); 416 } 417 418 int 419 intr_event_destroy(struct intr_event *ie) 420 { 421 422 mtx_lock(&event_lock); 423 mtx_lock(&ie->ie_lock); 424 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 425 mtx_unlock(&ie->ie_lock); 426 mtx_unlock(&event_lock); 427 return (EBUSY); 428 } 429 TAILQ_REMOVE(&event_list, ie, ie_list); 430 #ifndef notyet 431 if (ie->ie_thread != NULL) { 432 ithread_destroy(ie->ie_thread); 433 ie->ie_thread = NULL; 434 } 435 #endif 436 mtx_unlock(&ie->ie_lock); 437 mtx_unlock(&event_lock); 438 mtx_destroy(&ie->ie_lock); 439 free(ie, M_ITHREAD); 440 return (0); 441 } 442 443 #ifndef INTR_FILTER 444 static struct intr_thread * 445 ithread_create(const char *name) 446 { 447 struct intr_thread *ithd; 448 struct thread *td; 449 int error; 450 451 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 452 453 error = kproc_kthread_add(ithread_loop, ithd, &intrproc, 454 &td, RFSTOPPED | RFHIGHPID, 455 0, "intr", "%s", name); 456 if (error) 457 panic("kproc_create() failed with %d", error); 458 thread_lock(td); 459 sched_class(td, PRI_ITHD); 460 TD_SET_IWAIT(td); 461 thread_unlock(td); 462 td->td_pflags |= TDP_ITHREAD; 463 ithd->it_thread = td; 464 CTR2(KTR_INTR, "%s: created %s", __func__, name); 465 return (ithd); 466 } 467 #else 468 static struct intr_thread * 469 ithread_create(const char *name, struct intr_handler *ih) 470 { 471 struct intr_thread *ithd; 472 struct thread *td; 473 int error; 474 475 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 476 477 error = kproc_kthread_add(ithread_loop, ih, &intrproc, 478 &td, RFSTOPPED | RFHIGHPID, 479 0, "intr", "%s", name); 480 if (error) 481 panic("kproc_create() failed with %d", error); 482 thread_lock(td); 483 sched_class(td, PRI_ITHD); 484 TD_SET_IWAIT(td); 485 thread_unlock(td); 486 td->td_pflags |= TDP_ITHREAD; 487 ithd->it_thread = td; 488 CTR2(KTR_INTR, "%s: created %s", __func__, name); 489 return (ithd); 490 } 491 #endif 492 493 static void 494 ithread_destroy(struct intr_thread *ithread) 495 { 496 struct thread *td; 497 498 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name); 499 td = ithread->it_thread; 500 thread_lock(td); 501 ithread->it_flags |= IT_DEAD; 502 if (TD_AWAITING_INTR(td)) { 503 TD_CLR_IWAIT(td); 504 sched_add(td, SRQ_INTR); 505 } 506 thread_unlock(td); 507 } 508 509 #ifndef INTR_FILTER 510 int 511 intr_event_add_handler(struct intr_event *ie, const char *name, 512 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 513 enum intr_type flags, void **cookiep) 514 { 515 struct intr_handler *ih, *temp_ih; 516 struct intr_thread *it; 517 518 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 519 return (EINVAL); 520 521 /* Allocate and populate an interrupt handler structure. */ 522 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 523 ih->ih_filter = filter; 524 ih->ih_handler = handler; 525 ih->ih_argument = arg; 526 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 527 ih->ih_event = ie; 528 ih->ih_pri = pri; 529 if (flags & INTR_EXCL) 530 ih->ih_flags = IH_EXCLUSIVE; 531 if (flags & INTR_MPSAFE) 532 ih->ih_flags |= IH_MPSAFE; 533 if (flags & INTR_ENTROPY) 534 ih->ih_flags |= IH_ENTROPY; 535 536 /* We can only have one exclusive handler in a event. */ 537 mtx_lock(&ie->ie_lock); 538 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 539 if ((flags & INTR_EXCL) || 540 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 541 mtx_unlock(&ie->ie_lock); 542 free(ih, M_ITHREAD); 543 return (EINVAL); 544 } 545 } 546 547 /* Add the new handler to the event in priority order. */ 548 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) { 549 if (temp_ih->ih_pri > ih->ih_pri) 550 break; 551 } 552 if (temp_ih == NULL) 553 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next); 554 else 555 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 556 intr_event_update(ie); 557 558 /* Create a thread if we need one. */ 559 while (ie->ie_thread == NULL && handler != NULL) { 560 if (ie->ie_flags & IE_ADDING_THREAD) 561 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 562 else { 563 ie->ie_flags |= IE_ADDING_THREAD; 564 mtx_unlock(&ie->ie_lock); 565 it = ithread_create("intr: newborn"); 566 mtx_lock(&ie->ie_lock); 567 ie->ie_flags &= ~IE_ADDING_THREAD; 568 ie->ie_thread = it; 569 it->it_event = ie; 570 ithread_update(it); 571 wakeup(ie); 572 } 573 } 574 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 575 ie->ie_name); 576 mtx_unlock(&ie->ie_lock); 577 578 if (cookiep != NULL) 579 *cookiep = ih; 580 return (0); 581 } 582 #else 583 int 584 intr_event_add_handler(struct intr_event *ie, const char *name, 585 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 586 enum intr_type flags, void **cookiep) 587 { 588 struct intr_handler *ih, *temp_ih; 589 struct intr_thread *it; 590 591 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 592 return (EINVAL); 593 594 /* Allocate and populate an interrupt handler structure. */ 595 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 596 ih->ih_filter = filter; 597 ih->ih_handler = handler; 598 ih->ih_argument = arg; 599 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 600 ih->ih_event = ie; 601 ih->ih_pri = pri; 602 if (flags & INTR_EXCL) 603 ih->ih_flags = IH_EXCLUSIVE; 604 if (flags & INTR_MPSAFE) 605 ih->ih_flags |= IH_MPSAFE; 606 if (flags & INTR_ENTROPY) 607 ih->ih_flags |= IH_ENTROPY; 608 609 /* We can only have one exclusive handler in a event. */ 610 mtx_lock(&ie->ie_lock); 611 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 612 if ((flags & INTR_EXCL) || 613 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 614 mtx_unlock(&ie->ie_lock); 615 free(ih, M_ITHREAD); 616 return (EINVAL); 617 } 618 } 619 620 /* Add the new handler to the event in priority order. */ 621 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) { 622 if (temp_ih->ih_pri > ih->ih_pri) 623 break; 624 } 625 if (temp_ih == NULL) 626 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next); 627 else 628 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 629 intr_event_update(ie); 630 631 /* For filtered handlers, create a private ithread to run on. */ 632 if (filter != NULL && handler != NULL) { 633 mtx_unlock(&ie->ie_lock); 634 it = ithread_create("intr: newborn", ih); 635 mtx_lock(&ie->ie_lock); 636 it->it_event = ie; 637 ih->ih_thread = it; 638 ithread_update(it); // XXX - do we really need this?!?!? 639 } else { /* Create the global per-event thread if we need one. */ 640 while (ie->ie_thread == NULL && handler != NULL) { 641 if (ie->ie_flags & IE_ADDING_THREAD) 642 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 643 else { 644 ie->ie_flags |= IE_ADDING_THREAD; 645 mtx_unlock(&ie->ie_lock); 646 it = ithread_create("intr: newborn", ih); 647 mtx_lock(&ie->ie_lock); 648 ie->ie_flags &= ~IE_ADDING_THREAD; 649 ie->ie_thread = it; 650 it->it_event = ie; 651 ithread_update(it); 652 wakeup(ie); 653 } 654 } 655 } 656 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 657 ie->ie_name); 658 mtx_unlock(&ie->ie_lock); 659 660 if (cookiep != NULL) 661 *cookiep = ih; 662 return (0); 663 } 664 #endif 665 666 /* 667 * Append a description preceded by a ':' to the name of the specified 668 * interrupt handler. 669 */ 670 int 671 intr_event_describe_handler(struct intr_event *ie, void *cookie, 672 const char *descr) 673 { 674 struct intr_handler *ih; 675 size_t space; 676 char *start; 677 678 mtx_lock(&ie->ie_lock); 679 #ifdef INVARIANTS 680 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 681 if (ih == cookie) 682 break; 683 } 684 if (ih == NULL) { 685 mtx_unlock(&ie->ie_lock); 686 panic("handler %p not found in interrupt event %p", cookie, ie); 687 } 688 #endif 689 ih = cookie; 690 691 /* 692 * Look for an existing description by checking for an 693 * existing ":". This assumes device names do not include 694 * colons. If one is found, prepare to insert the new 695 * description at that point. If one is not found, find the 696 * end of the name to use as the insertion point. 697 */ 698 start = index(ih->ih_name, ':'); 699 if (start == NULL) 700 start = index(ih->ih_name, 0); 701 702 /* 703 * See if there is enough remaining room in the string for the 704 * description + ":". The "- 1" leaves room for the trailing 705 * '\0'. The "+ 1" accounts for the colon. 706 */ 707 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1; 708 if (strlen(descr) + 1 > space) { 709 mtx_unlock(&ie->ie_lock); 710 return (ENOSPC); 711 } 712 713 /* Append a colon followed by the description. */ 714 *start = ':'; 715 strcpy(start + 1, descr); 716 intr_event_update(ie); 717 mtx_unlock(&ie->ie_lock); 718 return (0); 719 } 720 721 /* 722 * Return the ie_source field from the intr_event an intr_handler is 723 * associated with. 724 */ 725 void * 726 intr_handler_source(void *cookie) 727 { 728 struct intr_handler *ih; 729 struct intr_event *ie; 730 731 ih = (struct intr_handler *)cookie; 732 if (ih == NULL) 733 return (NULL); 734 ie = ih->ih_event; 735 KASSERT(ie != NULL, 736 ("interrupt handler \"%s\" has a NULL interrupt event", 737 ih->ih_name)); 738 return (ie->ie_source); 739 } 740 741 #ifndef INTR_FILTER 742 int 743 intr_event_remove_handler(void *cookie) 744 { 745 struct intr_handler *handler = (struct intr_handler *)cookie; 746 struct intr_event *ie; 747 #ifdef INVARIANTS 748 struct intr_handler *ih; 749 #endif 750 #ifdef notyet 751 int dead; 752 #endif 753 754 if (handler == NULL) 755 return (EINVAL); 756 ie = handler->ih_event; 757 KASSERT(ie != NULL, 758 ("interrupt handler \"%s\" has a NULL interrupt event", 759 handler->ih_name)); 760 mtx_lock(&ie->ie_lock); 761 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 762 ie->ie_name); 763 #ifdef INVARIANTS 764 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 765 if (ih == handler) 766 goto ok; 767 mtx_unlock(&ie->ie_lock); 768 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"", 769 ih->ih_name, ie->ie_name); 770 ok: 771 #endif 772 /* 773 * If there is no ithread, then just remove the handler and return. 774 * XXX: Note that an INTR_FAST handler might be running on another 775 * CPU! 776 */ 777 if (ie->ie_thread == NULL) { 778 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 779 mtx_unlock(&ie->ie_lock); 780 free(handler, M_ITHREAD); 781 return (0); 782 } 783 784 /* 785 * If the interrupt thread is already running, then just mark this 786 * handler as being dead and let the ithread do the actual removal. 787 * 788 * During a cold boot while cold is set, msleep() does not sleep, 789 * so we have to remove the handler here rather than letting the 790 * thread do it. 791 */ 792 thread_lock(ie->ie_thread->it_thread); 793 if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) { 794 handler->ih_flags |= IH_DEAD; 795 796 /* 797 * Ensure that the thread will process the handler list 798 * again and remove this handler if it has already passed 799 * it on the list. 800 */ 801 ie->ie_thread->it_need = 1; 802 } else 803 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 804 thread_unlock(ie->ie_thread->it_thread); 805 while (handler->ih_flags & IH_DEAD) 806 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 807 intr_event_update(ie); 808 #ifdef notyet 809 /* 810 * XXX: This could be bad in the case of ppbus(8). Also, I think 811 * this could lead to races of stale data when servicing an 812 * interrupt. 813 */ 814 dead = 1; 815 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 816 if (!(ih->ih_flags & IH_FAST)) { 817 dead = 0; 818 break; 819 } 820 } 821 if (dead) { 822 ithread_destroy(ie->ie_thread); 823 ie->ie_thread = NULL; 824 } 825 #endif 826 mtx_unlock(&ie->ie_lock); 827 free(handler, M_ITHREAD); 828 return (0); 829 } 830 831 static int 832 intr_event_schedule_thread(struct intr_event *ie) 833 { 834 struct intr_entropy entropy; 835 struct intr_thread *it; 836 struct thread *td; 837 struct thread *ctd; 838 struct proc *p; 839 840 /* 841 * If no ithread or no handlers, then we have a stray interrupt. 842 */ 843 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || 844 ie->ie_thread == NULL) 845 return (EINVAL); 846 847 ctd = curthread; 848 it = ie->ie_thread; 849 td = it->it_thread; 850 p = td->td_proc; 851 852 /* 853 * If any of the handlers for this ithread claim to be good 854 * sources of entropy, then gather some. 855 */ 856 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) { 857 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__, 858 p->p_pid, td->td_name); 859 entropy.event = (uintptr_t)ie; 860 entropy.td = ctd; 861 random_harvest(&entropy, sizeof(entropy), 2, 0, 862 RANDOM_INTERRUPT); 863 } 864 865 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name)); 866 867 /* 868 * Set it_need to tell the thread to keep running if it is already 869 * running. Then, lock the thread and see if we actually need to 870 * put it on the runqueue. 871 */ 872 it->it_need = 1; 873 thread_lock(td); 874 if (TD_AWAITING_INTR(td)) { 875 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid, 876 td->td_name); 877 TD_CLR_IWAIT(td); 878 sched_add(td, SRQ_INTR); 879 } else { 880 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 881 __func__, p->p_pid, td->td_name, it->it_need, td->td_state); 882 } 883 thread_unlock(td); 884 885 return (0); 886 } 887 #else 888 int 889 intr_event_remove_handler(void *cookie) 890 { 891 struct intr_handler *handler = (struct intr_handler *)cookie; 892 struct intr_event *ie; 893 struct intr_thread *it; 894 #ifdef INVARIANTS 895 struct intr_handler *ih; 896 #endif 897 #ifdef notyet 898 int dead; 899 #endif 900 901 if (handler == NULL) 902 return (EINVAL); 903 ie = handler->ih_event; 904 KASSERT(ie != NULL, 905 ("interrupt handler \"%s\" has a NULL interrupt event", 906 handler->ih_name)); 907 mtx_lock(&ie->ie_lock); 908 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 909 ie->ie_name); 910 #ifdef INVARIANTS 911 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 912 if (ih == handler) 913 goto ok; 914 mtx_unlock(&ie->ie_lock); 915 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"", 916 ih->ih_name, ie->ie_name); 917 ok: 918 #endif 919 /* 920 * If there are no ithreads (per event and per handler), then 921 * just remove the handler and return. 922 * XXX: Note that an INTR_FAST handler might be running on another CPU! 923 */ 924 if (ie->ie_thread == NULL && handler->ih_thread == NULL) { 925 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 926 mtx_unlock(&ie->ie_lock); 927 free(handler, M_ITHREAD); 928 return (0); 929 } 930 931 /* Private or global ithread? */ 932 it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread; 933 /* 934 * If the interrupt thread is already running, then just mark this 935 * handler as being dead and let the ithread do the actual removal. 936 * 937 * During a cold boot while cold is set, msleep() does not sleep, 938 * so we have to remove the handler here rather than letting the 939 * thread do it. 940 */ 941 thread_lock(it->it_thread); 942 if (!TD_AWAITING_INTR(it->it_thread) && !cold) { 943 handler->ih_flags |= IH_DEAD; 944 945 /* 946 * Ensure that the thread will process the handler list 947 * again and remove this handler if it has already passed 948 * it on the list. 949 */ 950 it->it_need = 1; 951 } else 952 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 953 thread_unlock(it->it_thread); 954 while (handler->ih_flags & IH_DEAD) 955 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 956 /* 957 * At this point, the handler has been disconnected from the event, 958 * so we can kill the private ithread if any. 959 */ 960 if (handler->ih_thread) { 961 ithread_destroy(handler->ih_thread); 962 handler->ih_thread = NULL; 963 } 964 intr_event_update(ie); 965 #ifdef notyet 966 /* 967 * XXX: This could be bad in the case of ppbus(8). Also, I think 968 * this could lead to races of stale data when servicing an 969 * interrupt. 970 */ 971 dead = 1; 972 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 973 if (handler != NULL) { 974 dead = 0; 975 break; 976 } 977 } 978 if (dead) { 979 ithread_destroy(ie->ie_thread); 980 ie->ie_thread = NULL; 981 } 982 #endif 983 mtx_unlock(&ie->ie_lock); 984 free(handler, M_ITHREAD); 985 return (0); 986 } 987 988 static int 989 intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it) 990 { 991 struct intr_entropy entropy; 992 struct thread *td; 993 struct thread *ctd; 994 struct proc *p; 995 996 /* 997 * If no ithread or no handlers, then we have a stray interrupt. 998 */ 999 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || it == NULL) 1000 return (EINVAL); 1001 1002 ctd = curthread; 1003 td = it->it_thread; 1004 p = td->td_proc; 1005 1006 /* 1007 * If any of the handlers for this ithread claim to be good 1008 * sources of entropy, then gather some. 1009 */ 1010 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) { 1011 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__, 1012 p->p_pid, td->td_name); 1013 entropy.event = (uintptr_t)ie; 1014 entropy.td = ctd; 1015 random_harvest(&entropy, sizeof(entropy), 2, 0, 1016 RANDOM_INTERRUPT); 1017 } 1018 1019 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name)); 1020 1021 /* 1022 * Set it_need to tell the thread to keep running if it is already 1023 * running. Then, lock the thread and see if we actually need to 1024 * put it on the runqueue. 1025 */ 1026 it->it_need = 1; 1027 thread_lock(td); 1028 if (TD_AWAITING_INTR(td)) { 1029 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid, 1030 td->td_name); 1031 TD_CLR_IWAIT(td); 1032 sched_add(td, SRQ_INTR); 1033 } else { 1034 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 1035 __func__, p->p_pid, td->td_name, it->it_need, td->td_state); 1036 } 1037 thread_unlock(td); 1038 1039 return (0); 1040 } 1041 #endif 1042 1043 /* 1044 * Allow interrupt event binding for software interrupt handlers -- a no-op, 1045 * since interrupts are generated in software rather than being directed by 1046 * a PIC. 1047 */ 1048 static int 1049 swi_assign_cpu(void *arg, u_char cpu) 1050 { 1051 1052 return (0); 1053 } 1054 1055 /* 1056 * Add a software interrupt handler to a specified event. If a given event 1057 * is not specified, then a new event is created. 1058 */ 1059 int 1060 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler, 1061 void *arg, int pri, enum intr_type flags, void **cookiep) 1062 { 1063 struct thread *td; 1064 struct intr_event *ie; 1065 int error; 1066 1067 if (flags & INTR_ENTROPY) 1068 return (EINVAL); 1069 1070 ie = (eventp != NULL) ? *eventp : NULL; 1071 1072 if (ie != NULL) { 1073 if (!(ie->ie_flags & IE_SOFT)) 1074 return (EINVAL); 1075 } else { 1076 error = intr_event_create(&ie, NULL, IE_SOFT, 0, 1077 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri); 1078 if (error) 1079 return (error); 1080 if (eventp != NULL) 1081 *eventp = ie; 1082 } 1083 error = intr_event_add_handler(ie, name, NULL, handler, arg, 1084 PI_SWI(pri), flags, cookiep); 1085 if (error) 1086 return (error); 1087 if (pri == SWI_CLOCK) { 1088 td = ie->ie_thread->it_thread; 1089 thread_lock(td); 1090 td->td_flags |= TDF_NOLOAD; 1091 thread_unlock(td); 1092 } 1093 return (0); 1094 } 1095 1096 /* 1097 * Schedule a software interrupt thread. 1098 */ 1099 void 1100 swi_sched(void *cookie, int flags) 1101 { 1102 struct intr_handler *ih = (struct intr_handler *)cookie; 1103 struct intr_event *ie = ih->ih_event; 1104 int error; 1105 1106 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name, 1107 ih->ih_need); 1108 1109 /* 1110 * Set ih_need for this handler so that if the ithread is already 1111 * running it will execute this handler on the next pass. Otherwise, 1112 * it will execute it the next time it runs. 1113 */ 1114 atomic_store_rel_int(&ih->ih_need, 1); 1115 1116 if (!(flags & SWI_DELAY)) { 1117 PCPU_INC(cnt.v_soft); 1118 #ifdef INTR_FILTER 1119 error = intr_event_schedule_thread(ie, ie->ie_thread); 1120 #else 1121 error = intr_event_schedule_thread(ie); 1122 #endif 1123 KASSERT(error == 0, ("stray software interrupt")); 1124 } 1125 } 1126 1127 /* 1128 * Remove a software interrupt handler. Currently this code does not 1129 * remove the associated interrupt event if it becomes empty. Calling code 1130 * may do so manually via intr_event_destroy(), but that's not really 1131 * an optimal interface. 1132 */ 1133 int 1134 swi_remove(void *cookie) 1135 { 1136 1137 return (intr_event_remove_handler(cookie)); 1138 } 1139 1140 #ifdef INTR_FILTER 1141 static void 1142 priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih) 1143 { 1144 struct intr_event *ie; 1145 1146 ie = ih->ih_event; 1147 /* 1148 * If this handler is marked for death, remove it from 1149 * the list of handlers and wake up the sleeper. 1150 */ 1151 if (ih->ih_flags & IH_DEAD) { 1152 mtx_lock(&ie->ie_lock); 1153 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next); 1154 ih->ih_flags &= ~IH_DEAD; 1155 wakeup(ih); 1156 mtx_unlock(&ie->ie_lock); 1157 return; 1158 } 1159 1160 /* Execute this handler. */ 1161 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1162 __func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument, 1163 ih->ih_name, ih->ih_flags); 1164 1165 if (!(ih->ih_flags & IH_MPSAFE)) 1166 mtx_lock(&Giant); 1167 ih->ih_handler(ih->ih_argument); 1168 if (!(ih->ih_flags & IH_MPSAFE)) 1169 mtx_unlock(&Giant); 1170 } 1171 #endif 1172 1173 /* 1174 * This is a public function for use by drivers that mux interrupt 1175 * handlers for child devices from their interrupt handler. 1176 */ 1177 void 1178 intr_event_execute_handlers(struct proc *p, struct intr_event *ie) 1179 { 1180 struct intr_handler *ih, *ihn; 1181 1182 TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) { 1183 /* 1184 * If this handler is marked for death, remove it from 1185 * the list of handlers and wake up the sleeper. 1186 */ 1187 if (ih->ih_flags & IH_DEAD) { 1188 mtx_lock(&ie->ie_lock); 1189 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next); 1190 ih->ih_flags &= ~IH_DEAD; 1191 wakeup(ih); 1192 mtx_unlock(&ie->ie_lock); 1193 continue; 1194 } 1195 1196 /* Skip filter only handlers */ 1197 if (ih->ih_handler == NULL) 1198 continue; 1199 1200 /* 1201 * For software interrupt threads, we only execute 1202 * handlers that have their need flag set. Hardware 1203 * interrupt threads always invoke all of their handlers. 1204 */ 1205 if (ie->ie_flags & IE_SOFT) { 1206 if (!ih->ih_need) 1207 continue; 1208 else 1209 atomic_store_rel_int(&ih->ih_need, 0); 1210 } 1211 1212 /* Execute this handler. */ 1213 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1214 __func__, p->p_pid, (void *)ih->ih_handler, 1215 ih->ih_argument, ih->ih_name, ih->ih_flags); 1216 1217 if (!(ih->ih_flags & IH_MPSAFE)) 1218 mtx_lock(&Giant); 1219 ih->ih_handler(ih->ih_argument); 1220 if (!(ih->ih_flags & IH_MPSAFE)) 1221 mtx_unlock(&Giant); 1222 } 1223 } 1224 1225 static void 1226 ithread_execute_handlers(struct proc *p, struct intr_event *ie) 1227 { 1228 1229 /* Interrupt handlers should not sleep. */ 1230 if (!(ie->ie_flags & IE_SOFT)) 1231 THREAD_NO_SLEEPING(); 1232 intr_event_execute_handlers(p, ie); 1233 if (!(ie->ie_flags & IE_SOFT)) 1234 THREAD_SLEEPING_OK(); 1235 1236 /* 1237 * Interrupt storm handling: 1238 * 1239 * If this interrupt source is currently storming, then throttle 1240 * it to only fire the handler once per clock tick. 1241 * 1242 * If this interrupt source is not currently storming, but the 1243 * number of back to back interrupts exceeds the storm threshold, 1244 * then enter storming mode. 1245 */ 1246 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold && 1247 !(ie->ie_flags & IE_SOFT)) { 1248 /* Report the message only once every second. */ 1249 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) { 1250 printf( 1251 "interrupt storm detected on \"%s\"; throttling interrupt source\n", 1252 ie->ie_name); 1253 } 1254 pause("istorm", 1); 1255 } else 1256 ie->ie_count++; 1257 1258 /* 1259 * Now that all the handlers have had a chance to run, reenable 1260 * the interrupt source. 1261 */ 1262 if (ie->ie_post_ithread != NULL) 1263 ie->ie_post_ithread(ie->ie_source); 1264 } 1265 1266 #ifndef INTR_FILTER 1267 /* 1268 * This is the main code for interrupt threads. 1269 */ 1270 static void 1271 ithread_loop(void *arg) 1272 { 1273 struct intr_thread *ithd; 1274 struct intr_event *ie; 1275 struct thread *td; 1276 struct proc *p; 1277 1278 td = curthread; 1279 p = td->td_proc; 1280 ithd = (struct intr_thread *)arg; 1281 KASSERT(ithd->it_thread == td, 1282 ("%s: ithread and proc linkage out of sync", __func__)); 1283 ie = ithd->it_event; 1284 ie->ie_count = 0; 1285 1286 /* 1287 * As long as we have interrupts outstanding, go through the 1288 * list of handlers, giving each one a go at it. 1289 */ 1290 for (;;) { 1291 /* 1292 * If we are an orphaned thread, then just die. 1293 */ 1294 if (ithd->it_flags & IT_DEAD) { 1295 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1296 p->p_pid, td->td_name); 1297 free(ithd, M_ITHREAD); 1298 kthread_exit(); 1299 } 1300 1301 /* 1302 * Service interrupts. If another interrupt arrives while 1303 * we are running, it will set it_need to note that we 1304 * should make another pass. 1305 */ 1306 while (ithd->it_need) { 1307 /* 1308 * This might need a full read and write barrier 1309 * to make sure that this write posts before any 1310 * of the memory or device accesses in the 1311 * handlers. 1312 */ 1313 atomic_store_rel_int(&ithd->it_need, 0); 1314 ithread_execute_handlers(p, ie); 1315 } 1316 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1317 mtx_assert(&Giant, MA_NOTOWNED); 1318 1319 /* 1320 * Processed all our interrupts. Now get the sched 1321 * lock. This may take a while and it_need may get 1322 * set again, so we have to check it again. 1323 */ 1324 thread_lock(td); 1325 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) { 1326 TD_SET_IWAIT(td); 1327 ie->ie_count = 0; 1328 mi_switch(SW_VOL | SWT_IWAIT, NULL); 1329 } 1330 thread_unlock(td); 1331 } 1332 } 1333 1334 /* 1335 * Main interrupt handling body. 1336 * 1337 * Input: 1338 * o ie: the event connected to this interrupt. 1339 * o frame: some archs (i.e. i386) pass a frame to some. 1340 * handlers as their main argument. 1341 * Return value: 1342 * o 0: everything ok. 1343 * o EINVAL: stray interrupt. 1344 */ 1345 int 1346 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1347 { 1348 struct intr_handler *ih; 1349 struct thread *td; 1350 int error, ret, thread; 1351 1352 td = curthread; 1353 1354 /* An interrupt with no event or handlers is a stray interrupt. */ 1355 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers)) 1356 return (EINVAL); 1357 1358 /* 1359 * Execute fast interrupt handlers directly. 1360 * To support clock handlers, if a handler registers 1361 * with a NULL argument, then we pass it a pointer to 1362 * a trapframe as its argument. 1363 */ 1364 td->td_intr_nesting_level++; 1365 thread = 0; 1366 ret = 0; 1367 critical_enter(); 1368 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1369 if (ih->ih_filter == NULL) { 1370 thread = 1; 1371 continue; 1372 } 1373 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__, 1374 ih->ih_filter, ih->ih_argument == NULL ? frame : 1375 ih->ih_argument, ih->ih_name); 1376 if (ih->ih_argument == NULL) 1377 ret = ih->ih_filter(frame); 1378 else 1379 ret = ih->ih_filter(ih->ih_argument); 1380 KASSERT(ret == FILTER_STRAY || 1381 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1382 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1383 ("%s: incorrect return value %#x from %s", __func__, ret, 1384 ih->ih_name)); 1385 1386 /* 1387 * Wrapper handler special handling: 1388 * 1389 * in some particular cases (like pccard and pccbb), 1390 * the _real_ device handler is wrapped in a couple of 1391 * functions - a filter wrapper and an ithread wrapper. 1392 * In this case (and just in this case), the filter wrapper 1393 * could ask the system to schedule the ithread and mask 1394 * the interrupt source if the wrapped handler is composed 1395 * of just an ithread handler. 1396 * 1397 * TODO: write a generic wrapper to avoid people rolling 1398 * their own 1399 */ 1400 if (!thread) { 1401 if (ret == FILTER_SCHEDULE_THREAD) 1402 thread = 1; 1403 } 1404 } 1405 1406 if (thread) { 1407 if (ie->ie_pre_ithread != NULL) 1408 ie->ie_pre_ithread(ie->ie_source); 1409 } else { 1410 if (ie->ie_post_filter != NULL) 1411 ie->ie_post_filter(ie->ie_source); 1412 } 1413 1414 /* Schedule the ithread if needed. */ 1415 if (thread) { 1416 error = intr_event_schedule_thread(ie); 1417 #ifndef XEN 1418 KASSERT(error == 0, ("bad stray interrupt")); 1419 #else 1420 if (error != 0) 1421 log(LOG_WARNING, "bad stray interrupt"); 1422 #endif 1423 } 1424 critical_exit(); 1425 td->td_intr_nesting_level--; 1426 return (0); 1427 } 1428 #else 1429 /* 1430 * This is the main code for interrupt threads. 1431 */ 1432 static void 1433 ithread_loop(void *arg) 1434 { 1435 struct intr_thread *ithd; 1436 struct intr_handler *ih; 1437 struct intr_event *ie; 1438 struct thread *td; 1439 struct proc *p; 1440 int priv; 1441 1442 td = curthread; 1443 p = td->td_proc; 1444 ih = (struct intr_handler *)arg; 1445 priv = (ih->ih_thread != NULL) ? 1 : 0; 1446 ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread; 1447 KASSERT(ithd->it_thread == td, 1448 ("%s: ithread and proc linkage out of sync", __func__)); 1449 ie = ithd->it_event; 1450 ie->ie_count = 0; 1451 1452 /* 1453 * As long as we have interrupts outstanding, go through the 1454 * list of handlers, giving each one a go at it. 1455 */ 1456 for (;;) { 1457 /* 1458 * If we are an orphaned thread, then just die. 1459 */ 1460 if (ithd->it_flags & IT_DEAD) { 1461 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1462 p->p_pid, td->td_name); 1463 free(ithd, M_ITHREAD); 1464 kthread_exit(); 1465 } 1466 1467 /* 1468 * Service interrupts. If another interrupt arrives while 1469 * we are running, it will set it_need to note that we 1470 * should make another pass. 1471 */ 1472 while (ithd->it_need) { 1473 /* 1474 * This might need a full read and write barrier 1475 * to make sure that this write posts before any 1476 * of the memory or device accesses in the 1477 * handlers. 1478 */ 1479 atomic_store_rel_int(&ithd->it_need, 0); 1480 if (priv) 1481 priv_ithread_execute_handler(p, ih); 1482 else 1483 ithread_execute_handlers(p, ie); 1484 } 1485 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1486 mtx_assert(&Giant, MA_NOTOWNED); 1487 1488 /* 1489 * Processed all our interrupts. Now get the sched 1490 * lock. This may take a while and it_need may get 1491 * set again, so we have to check it again. 1492 */ 1493 thread_lock(td); 1494 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) { 1495 TD_SET_IWAIT(td); 1496 ie->ie_count = 0; 1497 mi_switch(SW_VOL | SWT_IWAIT, NULL); 1498 } 1499 thread_unlock(td); 1500 } 1501 } 1502 1503 /* 1504 * Main loop for interrupt filter. 1505 * 1506 * Some architectures (i386, amd64 and arm) require the optional frame 1507 * parameter, and use it as the main argument for fast handler execution 1508 * when ih_argument == NULL. 1509 * 1510 * Return value: 1511 * o FILTER_STRAY: No filter recognized the event, and no 1512 * filter-less handler is registered on this 1513 * line. 1514 * o FILTER_HANDLED: A filter claimed the event and served it. 1515 * o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at 1516 * least one filter-less handler on this line. 1517 * o FILTER_HANDLED | 1518 * FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for 1519 * scheduling the per-handler ithread. 1520 * 1521 * In case an ithread has to be scheduled, in *ithd there will be a 1522 * pointer to a struct intr_thread containing the thread to be 1523 * scheduled. 1524 */ 1525 1526 static int 1527 intr_filter_loop(struct intr_event *ie, struct trapframe *frame, 1528 struct intr_thread **ithd) 1529 { 1530 struct intr_handler *ih; 1531 void *arg; 1532 int ret, thread_only; 1533 1534 ret = 0; 1535 thread_only = 0; 1536 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1537 /* 1538 * Execute fast interrupt handlers directly. 1539 * To support clock handlers, if a handler registers 1540 * with a NULL argument, then we pass it a pointer to 1541 * a trapframe as its argument. 1542 */ 1543 arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument); 1544 1545 CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__, 1546 ih->ih_filter, ih->ih_handler, arg, ih->ih_name); 1547 1548 if (ih->ih_filter != NULL) 1549 ret = ih->ih_filter(arg); 1550 else { 1551 thread_only = 1; 1552 continue; 1553 } 1554 KASSERT(ret == FILTER_STRAY || 1555 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1556 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1557 ("%s: incorrect return value %#x from %s", __func__, ret, 1558 ih->ih_name)); 1559 if (ret & FILTER_STRAY) 1560 continue; 1561 else { 1562 *ithd = ih->ih_thread; 1563 return (ret); 1564 } 1565 } 1566 1567 /* 1568 * No filters handled the interrupt and we have at least 1569 * one handler without a filter. In this case, we schedule 1570 * all of the filter-less handlers to run in the ithread. 1571 */ 1572 if (thread_only) { 1573 *ithd = ie->ie_thread; 1574 return (FILTER_SCHEDULE_THREAD); 1575 } 1576 return (FILTER_STRAY); 1577 } 1578 1579 /* 1580 * Main interrupt handling body. 1581 * 1582 * Input: 1583 * o ie: the event connected to this interrupt. 1584 * o frame: some archs (i.e. i386) pass a frame to some. 1585 * handlers as their main argument. 1586 * Return value: 1587 * o 0: everything ok. 1588 * o EINVAL: stray interrupt. 1589 */ 1590 int 1591 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1592 { 1593 struct intr_thread *ithd; 1594 struct thread *td; 1595 int thread; 1596 1597 ithd = NULL; 1598 td = curthread; 1599 1600 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers)) 1601 return (EINVAL); 1602 1603 td->td_intr_nesting_level++; 1604 thread = 0; 1605 critical_enter(); 1606 thread = intr_filter_loop(ie, frame, &ithd); 1607 if (thread & FILTER_HANDLED) { 1608 if (ie->ie_post_filter != NULL) 1609 ie->ie_post_filter(ie->ie_source); 1610 } else { 1611 if (ie->ie_pre_ithread != NULL) 1612 ie->ie_pre_ithread(ie->ie_source); 1613 } 1614 critical_exit(); 1615 1616 /* Interrupt storm logic */ 1617 if (thread & FILTER_STRAY) { 1618 ie->ie_count++; 1619 if (ie->ie_count < intr_storm_threshold) 1620 printf("Interrupt stray detection not present\n"); 1621 } 1622 1623 /* Schedule an ithread if needed. */ 1624 if (thread & FILTER_SCHEDULE_THREAD) { 1625 if (intr_event_schedule_thread(ie, ithd) != 0) 1626 panic("%s: impossible stray interrupt", __func__); 1627 } 1628 td->td_intr_nesting_level--; 1629 return (0); 1630 } 1631 #endif 1632 1633 #ifdef DDB 1634 /* 1635 * Dump details about an interrupt handler 1636 */ 1637 static void 1638 db_dump_intrhand(struct intr_handler *ih) 1639 { 1640 int comma; 1641 1642 db_printf("\t%-10s ", ih->ih_name); 1643 switch (ih->ih_pri) { 1644 case PI_REALTIME: 1645 db_printf("CLK "); 1646 break; 1647 case PI_AV: 1648 db_printf("AV "); 1649 break; 1650 case PI_TTY: 1651 db_printf("TTY "); 1652 break; 1653 case PI_NET: 1654 db_printf("NET "); 1655 break; 1656 case PI_DISK: 1657 db_printf("DISK"); 1658 break; 1659 case PI_DULL: 1660 db_printf("DULL"); 1661 break; 1662 default: 1663 if (ih->ih_pri >= PI_SOFT) 1664 db_printf("SWI "); 1665 else 1666 db_printf("%4u", ih->ih_pri); 1667 break; 1668 } 1669 db_printf(" "); 1670 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC); 1671 db_printf("(%p)", ih->ih_argument); 1672 if (ih->ih_need || 1673 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD | 1674 IH_MPSAFE)) != 0) { 1675 db_printf(" {"); 1676 comma = 0; 1677 if (ih->ih_flags & IH_EXCLUSIVE) { 1678 if (comma) 1679 db_printf(", "); 1680 db_printf("EXCL"); 1681 comma = 1; 1682 } 1683 if (ih->ih_flags & IH_ENTROPY) { 1684 if (comma) 1685 db_printf(", "); 1686 db_printf("ENTROPY"); 1687 comma = 1; 1688 } 1689 if (ih->ih_flags & IH_DEAD) { 1690 if (comma) 1691 db_printf(", "); 1692 db_printf("DEAD"); 1693 comma = 1; 1694 } 1695 if (ih->ih_flags & IH_MPSAFE) { 1696 if (comma) 1697 db_printf(", "); 1698 db_printf("MPSAFE"); 1699 comma = 1; 1700 } 1701 if (ih->ih_need) { 1702 if (comma) 1703 db_printf(", "); 1704 db_printf("NEED"); 1705 } 1706 db_printf("}"); 1707 } 1708 db_printf("\n"); 1709 } 1710 1711 /* 1712 * Dump details about a event. 1713 */ 1714 void 1715 db_dump_intr_event(struct intr_event *ie, int handlers) 1716 { 1717 struct intr_handler *ih; 1718 struct intr_thread *it; 1719 int comma; 1720 1721 db_printf("%s ", ie->ie_fullname); 1722 it = ie->ie_thread; 1723 if (it != NULL) 1724 db_printf("(pid %d)", it->it_thread->td_proc->p_pid); 1725 else 1726 db_printf("(no thread)"); 1727 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 || 1728 (it != NULL && it->it_need)) { 1729 db_printf(" {"); 1730 comma = 0; 1731 if (ie->ie_flags & IE_SOFT) { 1732 db_printf("SOFT"); 1733 comma = 1; 1734 } 1735 if (ie->ie_flags & IE_ENTROPY) { 1736 if (comma) 1737 db_printf(", "); 1738 db_printf("ENTROPY"); 1739 comma = 1; 1740 } 1741 if (ie->ie_flags & IE_ADDING_THREAD) { 1742 if (comma) 1743 db_printf(", "); 1744 db_printf("ADDING_THREAD"); 1745 comma = 1; 1746 } 1747 if (it != NULL && it->it_need) { 1748 if (comma) 1749 db_printf(", "); 1750 db_printf("NEED"); 1751 } 1752 db_printf("}"); 1753 } 1754 db_printf("\n"); 1755 1756 if (handlers) 1757 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 1758 db_dump_intrhand(ih); 1759 } 1760 1761 /* 1762 * Dump data about interrupt handlers 1763 */ 1764 DB_SHOW_COMMAND(intr, db_show_intr) 1765 { 1766 struct intr_event *ie; 1767 int all, verbose; 1768 1769 verbose = index(modif, 'v') != NULL; 1770 all = index(modif, 'a') != NULL; 1771 TAILQ_FOREACH(ie, &event_list, ie_list) { 1772 if (!all && TAILQ_EMPTY(&ie->ie_handlers)) 1773 continue; 1774 db_dump_intr_event(ie, verbose); 1775 if (db_pager_quit) 1776 break; 1777 } 1778 } 1779 #endif /* DDB */ 1780 1781 /* 1782 * Start standard software interrupt threads 1783 */ 1784 static void 1785 start_softintr(void *dummy) 1786 { 1787 1788 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih)) 1789 panic("died while creating vm swi ithread"); 1790 } 1791 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, 1792 NULL); 1793 1794 /* 1795 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. 1796 * The data for this machine dependent, and the declarations are in machine 1797 * dependent code. The layout of intrnames and intrcnt however is machine 1798 * independent. 1799 * 1800 * We do not know the length of intrcnt and intrnames at compile time, so 1801 * calculate things at run time. 1802 */ 1803 static int 1804 sysctl_intrnames(SYSCTL_HANDLER_ARGS) 1805 { 1806 return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames, 1807 req)); 1808 } 1809 1810 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD, 1811 NULL, 0, sysctl_intrnames, "", "Interrupt Names"); 1812 1813 static int 1814 sysctl_intrcnt(SYSCTL_HANDLER_ARGS) 1815 { 1816 return (sysctl_handle_opaque(oidp, intrcnt, 1817 (char *)eintrcnt - (char *)intrcnt, req)); 1818 } 1819 1820 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD, 1821 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts"); 1822 1823 #ifdef DDB 1824 /* 1825 * DDB command to dump the interrupt statistics. 1826 */ 1827 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt) 1828 { 1829 u_long *i; 1830 char *cp; 1831 1832 cp = intrnames; 1833 for (i = intrcnt; i != eintrcnt && !db_pager_quit; i++) { 1834 if (*cp == '\0') 1835 break; 1836 if (*i != 0) 1837 db_printf("%s\t%lu\n", cp, *i); 1838 cp += strlen(cp) + 1; 1839 } 1840 } 1841 #endif
Cache object: dd927404c69dbe0ce7b306176c420960
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