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