Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_intr.c
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1 /*- 2 * Copyright (c) 1997, Stefan Esser <se@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD: releng/7.3/sys/kern/kern_intr.c 202763 2010-01-21 17:55:47Z jhb $"); 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/proc.h> 47 #include <sys/random.h> 48 #include <sys/resourcevar.h> 49 #include <sys/sched.h> 50 #include <sys/smp.h> 51 #include <sys/sysctl.h> 52 #include <sys/unistd.h> 53 #include <sys/vmmeter.h> 54 #include <machine/atomic.h> 55 #include <machine/cpu.h> 56 #include <machine/md_var.h> 57 #include <machine/stdarg.h> 58 #ifdef DDB 59 #include <ddb/ddb.h> 60 #include <ddb/db_sym.h> 61 #endif 62 63 /* 64 * Describe an interrupt thread. There is one of these per interrupt event. 65 */ 66 struct intr_thread { 67 struct intr_event *it_event; 68 struct thread *it_thread; /* Kernel thread. */ 69 int it_flags; /* (j) IT_* flags. */ 70 int it_need; /* Needs service. */ 71 }; 72 73 /* Interrupt thread flags kept in it_flags */ 74 #define IT_DEAD 0x000001 /* Thread is waiting to exit. */ 75 76 struct intr_entropy { 77 struct thread *td; 78 uintptr_t event; 79 }; 80 81 struct intr_event *clk_intr_event; 82 struct intr_event *tty_intr_event; 83 void *softclock_ih; 84 void *vm_ih; 85 86 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads"); 87 88 static int intr_storm_threshold = 1000; 89 TUNABLE_INT("hw.intr_storm_threshold", &intr_storm_threshold); 90 SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RW, 91 &intr_storm_threshold, 0, 92 "Number of consecutive interrupts before storm protection is enabled"); 93 static TAILQ_HEAD(, intr_event) event_list = 94 TAILQ_HEAD_INITIALIZER(event_list); 95 static struct mtx event_lock; 96 MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF); 97 98 static void intr_event_update(struct intr_event *ie); 99 #ifdef INTR_FILTER 100 static int intr_event_schedule_thread(struct intr_event *ie, 101 struct intr_thread *ithd); 102 static int intr_filter_loop(struct intr_event *ie, 103 struct trapframe *frame, struct intr_thread **ithd); 104 static struct intr_thread *ithread_create(const char *name, 105 struct intr_handler *ih); 106 #else 107 static int intr_event_schedule_thread(struct intr_event *ie); 108 static struct intr_thread *ithread_create(const char *name); 109 #endif 110 static void ithread_destroy(struct intr_thread *ithread); 111 static void ithread_execute_handlers(struct proc *p, 112 struct intr_event *ie); 113 #ifdef INTR_FILTER 114 static void priv_ithread_execute_handler(struct proc *p, 115 struct intr_handler *ih); 116 #endif 117 static void ithread_loop(void *); 118 static void ithread_update(struct intr_thread *ithd); 119 static void start_softintr(void *); 120 121 /* Map an interrupt type to an ithread priority. */ 122 u_char 123 intr_priority(enum intr_type flags) 124 { 125 u_char pri; 126 127 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET | 128 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV); 129 switch (flags) { 130 case INTR_TYPE_TTY: 131 pri = PI_TTYLOW; 132 break; 133 case INTR_TYPE_BIO: 134 /* 135 * XXX We need to refine this. BSD/OS distinguishes 136 * between tape and disk priorities. 137 */ 138 pri = PI_DISK; 139 break; 140 case INTR_TYPE_NET: 141 pri = PI_NET; 142 break; 143 case INTR_TYPE_CAM: 144 pri = PI_DISK; /* XXX or PI_CAM? */ 145 break; 146 case INTR_TYPE_AV: /* Audio/video */ 147 pri = PI_AV; 148 break; 149 case INTR_TYPE_CLK: 150 pri = PI_REALTIME; 151 break; 152 case INTR_TYPE_MISC: 153 pri = PI_DULL; /* don't care */ 154 break; 155 default: 156 /* We didn't specify an interrupt level. */ 157 panic("intr_priority: no interrupt type in flags"); 158 } 159 160 return pri; 161 } 162 163 /* 164 * Update an ithread based on the associated intr_event. 165 */ 166 static void 167 ithread_update(struct intr_thread *ithd) 168 { 169 struct intr_event *ie; 170 struct thread *td; 171 u_char pri; 172 173 ie = ithd->it_event; 174 td = ithd->it_thread; 175 176 /* Determine the overall priority of this event. */ 177 if (TAILQ_EMPTY(&ie->ie_handlers)) 178 pri = PRI_MAX_ITHD; 179 else 180 pri = TAILQ_FIRST(&ie->ie_handlers)->ih_pri; 181 182 /* Update name and priority. */ 183 strlcpy(td->td_proc->p_comm, ie->ie_fullname, 184 sizeof(td->td_proc->p_comm)); 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 * If we have any ithreads try to set their mask first since this 309 * can fail. 310 */ 311 mtx_lock(&ie->ie_lock); 312 if (ie->ie_thread != NULL) { 313 CPU_ZERO(&mask); 314 if (cpu == NOCPU) 315 CPU_COPY(cpuset_root, &mask); 316 else 317 CPU_SET(cpu, &mask); 318 id = ie->ie_thread->it_thread->td_tid; 319 mtx_unlock(&ie->ie_lock); 320 error = cpuset_setthread(id, &mask); 321 if (error) 322 return (error); 323 } else 324 mtx_unlock(&ie->ie_lock); 325 error = ie->ie_assign_cpu(ie->ie_source, cpu); 326 if (error) 327 return (error); 328 mtx_lock(&ie->ie_lock); 329 ie->ie_cpu = cpu; 330 mtx_unlock(&ie->ie_lock); 331 332 return (error); 333 } 334 335 static struct intr_event * 336 intr_lookup(int irq) 337 { 338 struct intr_event *ie; 339 340 mtx_lock(&event_lock); 341 TAILQ_FOREACH(ie, &event_list, ie_list) 342 if (ie->ie_irq == irq && 343 (ie->ie_flags & IE_SOFT) == 0 && 344 TAILQ_FIRST(&ie->ie_handlers) != NULL) 345 break; 346 mtx_unlock(&event_lock); 347 return (ie); 348 } 349 350 int 351 intr_setaffinity(int irq, void *m) 352 { 353 struct intr_event *ie; 354 cpuset_t *mask; 355 u_char cpu; 356 int n; 357 358 mask = m; 359 cpu = NOCPU; 360 /* 361 * If we're setting all cpus we can unbind. Otherwise make sure 362 * only one cpu is in the set. 363 */ 364 if (CPU_CMP(cpuset_root, mask)) { 365 for (n = 0; n < CPU_SETSIZE; n++) { 366 if (!CPU_ISSET(n, mask)) 367 continue; 368 if (cpu != NOCPU) 369 return (EINVAL); 370 cpu = (u_char)n; 371 } 372 } 373 ie = intr_lookup(irq); 374 if (ie == NULL) 375 return (ESRCH); 376 return (intr_event_bind(ie, cpu)); 377 } 378 379 int 380 intr_getaffinity(int irq, void *m) 381 { 382 struct intr_event *ie; 383 cpuset_t *mask; 384 385 mask = m; 386 ie = intr_lookup(irq); 387 if (ie == NULL) 388 return (ESRCH); 389 CPU_ZERO(mask); 390 mtx_lock(&ie->ie_lock); 391 if (ie->ie_cpu == NOCPU) 392 CPU_COPY(cpuset_root, mask); 393 else 394 CPU_SET(ie->ie_cpu, mask); 395 mtx_unlock(&ie->ie_lock); 396 return (0); 397 } 398 399 int 400 intr_event_destroy(struct intr_event *ie) 401 { 402 403 mtx_lock(&event_lock); 404 mtx_lock(&ie->ie_lock); 405 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 406 mtx_unlock(&ie->ie_lock); 407 mtx_unlock(&event_lock); 408 return (EBUSY); 409 } 410 TAILQ_REMOVE(&event_list, ie, ie_list); 411 #ifndef notyet 412 if (ie->ie_thread != NULL) { 413 ithread_destroy(ie->ie_thread); 414 ie->ie_thread = NULL; 415 } 416 #endif 417 mtx_unlock(&ie->ie_lock); 418 mtx_unlock(&event_lock); 419 mtx_destroy(&ie->ie_lock); 420 free(ie, M_ITHREAD); 421 return (0); 422 } 423 424 #ifndef INTR_FILTER 425 static struct intr_thread * 426 ithread_create(const char *name) 427 { 428 struct intr_thread *ithd; 429 struct thread *td; 430 struct proc *p; 431 int error; 432 433 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 434 435 error = kthread_create(ithread_loop, ithd, &p, RFSTOPPED | RFHIGHPID, 436 0, "%s", name); 437 if (error) 438 panic("kthread_create() failed with %d", error); 439 td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */ 440 thread_lock(td); 441 sched_class(td, PRI_ITHD); 442 TD_SET_IWAIT(td); 443 thread_unlock(td); 444 td->td_pflags |= TDP_ITHREAD; 445 ithd->it_thread = td; 446 CTR2(KTR_INTR, "%s: created %s", __func__, name); 447 return (ithd); 448 } 449 #else 450 static struct intr_thread * 451 ithread_create(const char *name, struct intr_handler *ih) 452 { 453 struct intr_thread *ithd; 454 struct thread *td; 455 struct proc *p; 456 int error; 457 458 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 459 460 error = kthread_create(ithread_loop, ih, &p, RFSTOPPED | RFHIGHPID, 461 0, "%s", name); 462 if (error) 463 panic("kthread_create() failed with %d", error); 464 td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */ 465 thread_lock(td); 466 sched_class(td, PRI_ITHD); 467 TD_SET_IWAIT(td); 468 thread_unlock(td); 469 td->td_pflags |= TDP_ITHREAD; 470 ithd->it_thread = td; 471 CTR2(KTR_INTR, "%s: created %s", __func__, name); 472 return (ithd); 473 } 474 #endif 475 476 static void 477 ithread_destroy(struct intr_thread *ithread) 478 { 479 struct thread *td; 480 481 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name); 482 td = ithread->it_thread; 483 thread_lock(td); 484 ithread->it_flags |= IT_DEAD; 485 if (TD_AWAITING_INTR(td)) { 486 TD_CLR_IWAIT(td); 487 sched_add(td, SRQ_INTR); 488 } 489 thread_unlock(td); 490 } 491 492 #ifndef INTR_FILTER 493 int 494 intr_event_add_handler(struct intr_event *ie, const char *name, 495 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 496 enum intr_type flags, void **cookiep) 497 { 498 struct intr_handler *ih, *temp_ih; 499 struct intr_thread *it; 500 501 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 502 return (EINVAL); 503 504 /* Allocate and populate an interrupt handler structure. */ 505 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 506 ih->ih_filter = filter; 507 ih->ih_handler = handler; 508 ih->ih_argument = arg; 509 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 510 ih->ih_event = ie; 511 ih->ih_pri = pri; 512 if (flags & INTR_EXCL) 513 ih->ih_flags = IH_EXCLUSIVE; 514 if (flags & INTR_MPSAFE) 515 ih->ih_flags |= IH_MPSAFE; 516 if (flags & INTR_ENTROPY) 517 ih->ih_flags |= IH_ENTROPY; 518 519 /* We can only have one exclusive handler in a event. */ 520 mtx_lock(&ie->ie_lock); 521 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 522 if ((flags & INTR_EXCL) || 523 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 524 mtx_unlock(&ie->ie_lock); 525 free(ih, M_ITHREAD); 526 return (EINVAL); 527 } 528 } 529 530 /* Add the new handler to the event in priority order. */ 531 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) { 532 if (temp_ih->ih_pri > ih->ih_pri) 533 break; 534 } 535 if (temp_ih == NULL) 536 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next); 537 else 538 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 539 intr_event_update(ie); 540 541 /* Create a thread if we need one. */ 542 while (ie->ie_thread == NULL && handler != NULL) { 543 if (ie->ie_flags & IE_ADDING_THREAD) 544 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 545 else { 546 ie->ie_flags |= IE_ADDING_THREAD; 547 mtx_unlock(&ie->ie_lock); 548 it = ithread_create("intr: newborn"); 549 mtx_lock(&ie->ie_lock); 550 ie->ie_flags &= ~IE_ADDING_THREAD; 551 ie->ie_thread = it; 552 it->it_event = ie; 553 ithread_update(it); 554 wakeup(ie); 555 } 556 } 557 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 558 ie->ie_name); 559 mtx_unlock(&ie->ie_lock); 560 561 if (cookiep != NULL) 562 *cookiep = ih; 563 return (0); 564 } 565 #else 566 int 567 intr_event_add_handler(struct intr_event *ie, const char *name, 568 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 569 enum intr_type flags, void **cookiep) 570 { 571 struct intr_handler *ih, *temp_ih; 572 struct intr_thread *it; 573 574 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 575 return (EINVAL); 576 577 /* Allocate and populate an interrupt handler structure. */ 578 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 579 ih->ih_filter = filter; 580 ih->ih_handler = handler; 581 ih->ih_argument = arg; 582 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 583 ih->ih_event = ie; 584 ih->ih_pri = pri; 585 if (flags & INTR_EXCL) 586 ih->ih_flags = IH_EXCLUSIVE; 587 if (flags & INTR_MPSAFE) 588 ih->ih_flags |= IH_MPSAFE; 589 if (flags & INTR_ENTROPY) 590 ih->ih_flags |= IH_ENTROPY; 591 592 /* We can only have one exclusive handler in a event. */ 593 mtx_lock(&ie->ie_lock); 594 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 595 if ((flags & INTR_EXCL) || 596 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 597 mtx_unlock(&ie->ie_lock); 598 free(ih, M_ITHREAD); 599 return (EINVAL); 600 } 601 } 602 603 /* Add the new handler to the event in priority order. */ 604 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) { 605 if (temp_ih->ih_pri > ih->ih_pri) 606 break; 607 } 608 if (temp_ih == NULL) 609 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next); 610 else 611 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 612 intr_event_update(ie); 613 614 /* For filtered handlers, create a private ithread to run on. */ 615 if (filter != NULL && handler != NULL) { 616 mtx_unlock(&ie->ie_lock); 617 it = ithread_create("intr: newborn", ih); 618 mtx_lock(&ie->ie_lock); 619 it->it_event = ie; 620 ih->ih_thread = it; 621 ithread_update(it); // XXX - do we really need this?!?!? 622 } else { /* Create the global per-event thread if we need one. */ 623 while (ie->ie_thread == NULL && handler != NULL) { 624 if (ie->ie_flags & IE_ADDING_THREAD) 625 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 626 else { 627 ie->ie_flags |= IE_ADDING_THREAD; 628 mtx_unlock(&ie->ie_lock); 629 it = ithread_create("intr: newborn", ih); 630 mtx_lock(&ie->ie_lock); 631 ie->ie_flags &= ~IE_ADDING_THREAD; 632 ie->ie_thread = it; 633 it->it_event = ie; 634 ithread_update(it); 635 wakeup(ie); 636 } 637 } 638 } 639 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 640 ie->ie_name); 641 mtx_unlock(&ie->ie_lock); 642 643 if (cookiep != NULL) 644 *cookiep = ih; 645 return (0); 646 } 647 #endif 648 649 /* 650 * Append a description preceded by a ':' to the name of the specified 651 * interrupt handler. 652 */ 653 int 654 intr_event_describe_handler(struct intr_event *ie, void *cookie, 655 const char *descr) 656 { 657 struct intr_handler *ih; 658 size_t space; 659 char *start; 660 661 mtx_lock(&ie->ie_lock); 662 #ifdef INVARIANTS 663 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 664 if (ih == cookie) 665 break; 666 } 667 if (ih == NULL) { 668 mtx_unlock(&ie->ie_lock); 669 panic("handler %p not found in interrupt event %p", cookie, ie); 670 } 671 #endif 672 ih = cookie; 673 674 /* 675 * Look for an existing description by checking for an 676 * existing ":". This assumes device names do not include 677 * colons. If one is found, prepare to insert the new 678 * description at that point. If one is not found, find the 679 * end of the name to use as the insertion point. 680 */ 681 start = index(ih->ih_name, ':'); 682 if (start == NULL) 683 start = index(ih->ih_name, 0); 684 685 /* 686 * See if there is enough remaining room in the string for the 687 * description + ":". The "- 1" leaves room for the trailing 688 * '\0'. The "+ 1" accounts for the colon. 689 */ 690 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1; 691 if (strlen(descr) + 1 > space) { 692 mtx_unlock(&ie->ie_lock); 693 return (ENOSPC); 694 } 695 696 /* Append a colon followed by the description. */ 697 *start = ':'; 698 strcpy(start + 1, descr); 699 intr_event_update(ie); 700 mtx_unlock(&ie->ie_lock); 701 return (0); 702 } 703 704 /* 705 * Return the ie_source field from the intr_event an intr_handler is 706 * associated with. 707 */ 708 void * 709 intr_handler_source(void *cookie) 710 { 711 struct intr_handler *ih; 712 struct intr_event *ie; 713 714 ih = (struct intr_handler *)cookie; 715 if (ih == NULL) 716 return (NULL); 717 ie = ih->ih_event; 718 KASSERT(ie != NULL, 719 ("interrupt handler \"%s\" has a NULL interrupt event", 720 ih->ih_name)); 721 return (ie->ie_source); 722 } 723 724 #ifndef INTR_FILTER 725 int 726 intr_event_remove_handler(void *cookie) 727 { 728 struct intr_handler *handler = (struct intr_handler *)cookie; 729 struct intr_event *ie; 730 #ifdef INVARIANTS 731 struct intr_handler *ih; 732 #endif 733 #ifdef notyet 734 int dead; 735 #endif 736 737 if (handler == NULL) 738 return (EINVAL); 739 ie = handler->ih_event; 740 KASSERT(ie != NULL, 741 ("interrupt handler \"%s\" has a NULL interrupt event", 742 handler->ih_name)); 743 mtx_lock(&ie->ie_lock); 744 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 745 ie->ie_name); 746 #ifdef INVARIANTS 747 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 748 if (ih == handler) 749 goto ok; 750 mtx_unlock(&ie->ie_lock); 751 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"", 752 ih->ih_name, ie->ie_name); 753 ok: 754 #endif 755 /* 756 * If there is no ithread, then just remove the handler and return. 757 * XXX: Note that an INTR_FAST handler might be running on another 758 * CPU! 759 */ 760 if (ie->ie_thread == NULL) { 761 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 762 mtx_unlock(&ie->ie_lock); 763 free(handler, M_ITHREAD); 764 return (0); 765 } 766 767 /* 768 * If the interrupt thread is already running, then just mark this 769 * handler as being dead and let the ithread do the actual removal. 770 * 771 * During a cold boot while cold is set, msleep() does not sleep, 772 * so we have to remove the handler here rather than letting the 773 * thread do it. 774 */ 775 thread_lock(ie->ie_thread->it_thread); 776 if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) { 777 handler->ih_flags |= IH_DEAD; 778 779 /* 780 * Ensure that the thread will process the handler list 781 * again and remove this handler if it has already passed 782 * it on the list. 783 */ 784 ie->ie_thread->it_need = 1; 785 } else 786 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 787 thread_unlock(ie->ie_thread->it_thread); 788 while (handler->ih_flags & IH_DEAD) 789 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 790 intr_event_update(ie); 791 #ifdef notyet 792 /* 793 * XXX: This could be bad in the case of ppbus(8). Also, I think 794 * this could lead to races of stale data when servicing an 795 * interrupt. 796 */ 797 dead = 1; 798 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 799 if (!(ih->ih_flags & IH_FAST)) { 800 dead = 0; 801 break; 802 } 803 } 804 if (dead) { 805 ithread_destroy(ie->ie_thread); 806 ie->ie_thread = NULL; 807 } 808 #endif 809 mtx_unlock(&ie->ie_lock); 810 free(handler, M_ITHREAD); 811 return (0); 812 } 813 814 static int 815 intr_event_schedule_thread(struct intr_event *ie) 816 { 817 struct intr_entropy entropy; 818 struct intr_thread *it; 819 struct thread *td; 820 struct thread *ctd; 821 struct proc *p; 822 823 /* 824 * If no ithread or no handlers, then we have a stray interrupt. 825 */ 826 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || 827 ie->ie_thread == NULL) 828 return (EINVAL); 829 830 ctd = curthread; 831 it = ie->ie_thread; 832 td = it->it_thread; 833 p = td->td_proc; 834 835 /* 836 * If any of the handlers for this ithread claim to be good 837 * sources of entropy, then gather some. 838 */ 839 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) { 840 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__, 841 p->p_pid, p->p_comm); 842 entropy.event = (uintptr_t)ie; 843 entropy.td = ctd; 844 random_harvest(&entropy, sizeof(entropy), 2, 0, 845 RANDOM_INTERRUPT); 846 } 847 848 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name)); 849 850 /* 851 * Set it_need to tell the thread to keep running if it is already 852 * running. Then, lock the thread and see if we actually need to 853 * put it on the runqueue. 854 */ 855 it->it_need = 1; 856 thread_lock(td); 857 if (TD_AWAITING_INTR(td)) { 858 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid, 859 p->p_comm); 860 TD_CLR_IWAIT(td); 861 sched_add(td, SRQ_INTR); 862 } else { 863 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 864 __func__, p->p_pid, p->p_comm, it->it_need, td->td_state); 865 } 866 thread_unlock(td); 867 868 return (0); 869 } 870 #else 871 int 872 intr_event_remove_handler(void *cookie) 873 { 874 struct intr_handler *handler = (struct intr_handler *)cookie; 875 struct intr_event *ie; 876 struct intr_thread *it; 877 #ifdef INVARIANTS 878 struct intr_handler *ih; 879 #endif 880 #ifdef notyet 881 int dead; 882 #endif 883 884 if (handler == NULL) 885 return (EINVAL); 886 ie = handler->ih_event; 887 KASSERT(ie != NULL, 888 ("interrupt handler \"%s\" has a NULL interrupt event", 889 handler->ih_name)); 890 mtx_lock(&ie->ie_lock); 891 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 892 ie->ie_name); 893 #ifdef INVARIANTS 894 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 895 if (ih == handler) 896 goto ok; 897 mtx_unlock(&ie->ie_lock); 898 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"", 899 ih->ih_name, ie->ie_name); 900 ok: 901 #endif 902 /* 903 * If there are no ithreads (per event and per handler), then 904 * just remove the handler and return. 905 * XXX: Note that an INTR_FAST handler might be running on another CPU! 906 */ 907 if (ie->ie_thread == NULL && handler->ih_thread == NULL) { 908 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 909 mtx_unlock(&ie->ie_lock); 910 free(handler, M_ITHREAD); 911 return (0); 912 } 913 914 /* Private or global ithread? */ 915 it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread; 916 /* 917 * If the interrupt thread is already running, then just mark this 918 * handler as being dead and let the ithread do the actual removal. 919 * 920 * During a cold boot while cold is set, msleep() does not sleep, 921 * so we have to remove the handler here rather than letting the 922 * thread do it. 923 */ 924 thread_lock(it->it_thread); 925 if (!TD_AWAITING_INTR(it->it_thread) && !cold) { 926 handler->ih_flags |= IH_DEAD; 927 928 /* 929 * Ensure that the thread will process the handler list 930 * again and remove this handler if it has already passed 931 * it on the list. 932 */ 933 it->it_need = 1; 934 } else 935 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 936 thread_unlock(it->it_thread); 937 while (handler->ih_flags & IH_DEAD) 938 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 939 /* 940 * At this point, the handler has been disconnected from the event, 941 * so we can kill the private ithread if any. 942 */ 943 if (handler->ih_thread) { 944 ithread_destroy(handler->ih_thread); 945 handler->ih_thread = NULL; 946 } 947 intr_event_update(ie); 948 #ifdef notyet 949 /* 950 * XXX: This could be bad in the case of ppbus(8). Also, I think 951 * this could lead to races of stale data when servicing an 952 * interrupt. 953 */ 954 dead = 1; 955 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 956 if (handler != NULL) { 957 dead = 0; 958 break; 959 } 960 } 961 if (dead) { 962 ithread_destroy(ie->ie_thread); 963 ie->ie_thread = NULL; 964 } 965 #endif 966 mtx_unlock(&ie->ie_lock); 967 free(handler, M_ITHREAD); 968 return (0); 969 } 970 971 static int 972 intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it) 973 { 974 struct intr_entropy entropy; 975 struct thread *td; 976 struct thread *ctd; 977 struct proc *p; 978 979 /* 980 * If no ithread or no handlers, then we have a stray interrupt. 981 */ 982 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || it == NULL) 983 return (EINVAL); 984 985 ctd = curthread; 986 td = it->it_thread; 987 p = td->td_proc; 988 989 /* 990 * If any of the handlers for this ithread claim to be good 991 * sources of entropy, then gather some. 992 */ 993 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) { 994 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__, 995 p->p_pid, p->p_comm); 996 entropy.event = (uintptr_t)ie; 997 entropy.td = ctd; 998 random_harvest(&entropy, sizeof(entropy), 2, 0, 999 RANDOM_INTERRUPT); 1000 } 1001 1002 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name)); 1003 1004 /* 1005 * Set it_need to tell the thread to keep running if it is already 1006 * running. Then, lock the thread and see if we actually need to 1007 * put it on the runqueue. 1008 */ 1009 it->it_need = 1; 1010 thread_lock(td); 1011 if (TD_AWAITING_INTR(td)) { 1012 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid, 1013 p->p_comm); 1014 TD_CLR_IWAIT(td); 1015 sched_add(td, SRQ_INTR); 1016 } else { 1017 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 1018 __func__, p->p_pid, p->p_comm, it->it_need, td->td_state); 1019 } 1020 thread_unlock(td); 1021 1022 return (0); 1023 } 1024 #endif 1025 1026 /* 1027 * Add a software interrupt handler to a specified event. If a given event 1028 * is not specified, then a new event is created. 1029 */ 1030 int 1031 swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler, 1032 void *arg, int pri, enum intr_type flags, void **cookiep) 1033 { 1034 struct intr_event *ie; 1035 int error; 1036 1037 if (flags & INTR_ENTROPY) 1038 return (EINVAL); 1039 1040 ie = (eventp != NULL) ? *eventp : NULL; 1041 1042 if (ie != NULL) { 1043 if (!(ie->ie_flags & IE_SOFT)) 1044 return (EINVAL); 1045 } else { 1046 error = intr_event_create(&ie, NULL, IE_SOFT, 0, 1047 NULL, NULL, NULL, NULL, "swi%d:", pri); 1048 if (error) 1049 return (error); 1050 if (eventp != NULL) 1051 *eventp = ie; 1052 } 1053 return (intr_event_add_handler(ie, name, NULL, handler, arg, 1054 (pri * RQ_PPQ) + PI_SOFT, flags, cookiep)); 1055 /* XXKSE.. think of a better way to get separate queues */ 1056 } 1057 1058 /* 1059 * Schedule a software interrupt thread. 1060 */ 1061 void 1062 swi_sched(void *cookie, int flags) 1063 { 1064 struct intr_handler *ih = (struct intr_handler *)cookie; 1065 struct intr_event *ie = ih->ih_event; 1066 int error; 1067 1068 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name, 1069 ih->ih_need); 1070 1071 /* 1072 * Set ih_need for this handler so that if the ithread is already 1073 * running it will execute this handler on the next pass. Otherwise, 1074 * it will execute it the next time it runs. 1075 */ 1076 atomic_store_rel_int(&ih->ih_need, 1); 1077 1078 if (!(flags & SWI_DELAY)) { 1079 PCPU_INC(cnt.v_soft); 1080 #ifdef INTR_FILTER 1081 error = intr_event_schedule_thread(ie, ie->ie_thread); 1082 #else 1083 error = intr_event_schedule_thread(ie); 1084 #endif 1085 KASSERT(error == 0, ("stray software interrupt")); 1086 } 1087 } 1088 1089 /* 1090 * Remove a software interrupt handler. Currently this code does not 1091 * remove the associated interrupt event if it becomes empty. Calling code 1092 * may do so manually via intr_event_destroy(), but that's not really 1093 * an optimal interface. 1094 */ 1095 int 1096 swi_remove(void *cookie) 1097 { 1098 1099 return (intr_event_remove_handler(cookie)); 1100 } 1101 1102 #ifdef INTR_FILTER 1103 static void 1104 priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih) 1105 { 1106 struct intr_event *ie; 1107 1108 ie = ih->ih_event; 1109 /* 1110 * If this handler is marked for death, remove it from 1111 * the list of handlers and wake up the sleeper. 1112 */ 1113 if (ih->ih_flags & IH_DEAD) { 1114 mtx_lock(&ie->ie_lock); 1115 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next); 1116 ih->ih_flags &= ~IH_DEAD; 1117 wakeup(ih); 1118 mtx_unlock(&ie->ie_lock); 1119 return; 1120 } 1121 1122 /* Execute this handler. */ 1123 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1124 __func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument, 1125 ih->ih_name, ih->ih_flags); 1126 1127 if (!(ih->ih_flags & IH_MPSAFE)) 1128 mtx_lock(&Giant); 1129 ih->ih_handler(ih->ih_argument); 1130 if (!(ih->ih_flags & IH_MPSAFE)) 1131 mtx_unlock(&Giant); 1132 } 1133 #endif 1134 1135 static void 1136 ithread_execute_handlers(struct proc *p, struct intr_event *ie) 1137 { 1138 struct intr_handler *ih, *ihn; 1139 1140 /* Interrupt handlers should not sleep. */ 1141 if (!(ie->ie_flags & IE_SOFT)) 1142 THREAD_NO_SLEEPING(); 1143 TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) { 1144 1145 /* 1146 * If this handler is marked for death, remove it from 1147 * the list of handlers and wake up the sleeper. 1148 */ 1149 if (ih->ih_flags & IH_DEAD) { 1150 mtx_lock(&ie->ie_lock); 1151 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next); 1152 ih->ih_flags &= ~IH_DEAD; 1153 wakeup(ih); 1154 mtx_unlock(&ie->ie_lock); 1155 continue; 1156 } 1157 1158 /* Skip filter only handlers */ 1159 if (ih->ih_handler == NULL) 1160 continue; 1161 1162 /* 1163 * For software interrupt threads, we only execute 1164 * handlers that have their need flag set. Hardware 1165 * interrupt threads always invoke all of their handlers. 1166 */ 1167 if (ie->ie_flags & IE_SOFT) { 1168 if (!ih->ih_need) 1169 continue; 1170 else 1171 atomic_store_rel_int(&ih->ih_need, 0); 1172 } 1173 1174 /* Execute this handler. */ 1175 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1176 __func__, p->p_pid, (void *)ih->ih_handler, 1177 ih->ih_argument, ih->ih_name, ih->ih_flags); 1178 1179 if (!(ih->ih_flags & IH_MPSAFE)) 1180 mtx_lock(&Giant); 1181 ih->ih_handler(ih->ih_argument); 1182 if (!(ih->ih_flags & IH_MPSAFE)) 1183 mtx_unlock(&Giant); 1184 } 1185 if (!(ie->ie_flags & IE_SOFT)) 1186 THREAD_SLEEPING_OK(); 1187 1188 /* 1189 * Interrupt storm handling: 1190 * 1191 * If this interrupt source is currently storming, then throttle 1192 * it to only fire the handler once per clock tick. 1193 * 1194 * If this interrupt source is not currently storming, but the 1195 * number of back to back interrupts exceeds the storm threshold, 1196 * then enter storming mode. 1197 */ 1198 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold && 1199 !(ie->ie_flags & IE_SOFT)) { 1200 /* Report the message only once every second. */ 1201 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) { 1202 printf( 1203 "interrupt storm detected on \"%s\"; throttling interrupt source\n", 1204 ie->ie_name); 1205 } 1206 pause("istorm", 1); 1207 } else 1208 ie->ie_count++; 1209 1210 /* 1211 * Now that all the handlers have had a chance to run, reenable 1212 * the interrupt source. 1213 */ 1214 if (ie->ie_post_ithread != NULL) 1215 ie->ie_post_ithread(ie->ie_source); 1216 } 1217 1218 #ifndef INTR_FILTER 1219 /* 1220 * This is the main code for interrupt threads. 1221 */ 1222 static void 1223 ithread_loop(void *arg) 1224 { 1225 struct intr_thread *ithd; 1226 struct intr_event *ie; 1227 struct thread *td; 1228 struct proc *p; 1229 1230 td = curthread; 1231 p = td->td_proc; 1232 ithd = (struct intr_thread *)arg; 1233 KASSERT(ithd->it_thread == td, 1234 ("%s: ithread and proc linkage out of sync", __func__)); 1235 ie = ithd->it_event; 1236 ie->ie_count = 0; 1237 1238 /* 1239 * As long as we have interrupts outstanding, go through the 1240 * list of handlers, giving each one a go at it. 1241 */ 1242 for (;;) { 1243 /* 1244 * If we are an orphaned thread, then just die. 1245 */ 1246 if (ithd->it_flags & IT_DEAD) { 1247 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1248 p->p_pid, p->p_comm); 1249 free(ithd, M_ITHREAD); 1250 kthread_exit(0); 1251 } 1252 1253 /* 1254 * Service interrupts. If another interrupt arrives while 1255 * we are running, it will set it_need to note that we 1256 * should make another pass. 1257 */ 1258 while (ithd->it_need) { 1259 /* 1260 * This might need a full read and write barrier 1261 * to make sure that this write posts before any 1262 * of the memory or device accesses in the 1263 * handlers. 1264 */ 1265 atomic_store_rel_int(&ithd->it_need, 0); 1266 ithread_execute_handlers(p, ie); 1267 } 1268 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1269 mtx_assert(&Giant, MA_NOTOWNED); 1270 1271 /* 1272 * Processed all our interrupts. Now get the sched 1273 * lock. This may take a while and it_need may get 1274 * set again, so we have to check it again. 1275 */ 1276 thread_lock(td); 1277 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) { 1278 TD_SET_IWAIT(td); 1279 ie->ie_count = 0; 1280 mi_switch(SW_VOL, NULL); 1281 } 1282 thread_unlock(td); 1283 } 1284 } 1285 1286 /* 1287 * Main interrupt handling body. 1288 * 1289 * Input: 1290 * o ie: the event connected to this interrupt. 1291 * o frame: some archs (i.e. i386) pass a frame to some. 1292 * handlers as their main argument. 1293 * Return value: 1294 * o 0: everything ok. 1295 * o EINVAL: stray interrupt. 1296 */ 1297 int 1298 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1299 { 1300 struct intr_handler *ih; 1301 struct thread *td; 1302 int error, ret, thread; 1303 1304 td = curthread; 1305 1306 /* An interrupt with no event or handlers is a stray interrupt. */ 1307 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers)) 1308 return (EINVAL); 1309 1310 /* 1311 * Execute fast interrupt handlers directly. 1312 * To support clock handlers, if a handler registers 1313 * with a NULL argument, then we pass it a pointer to 1314 * a trapframe as its argument. 1315 */ 1316 td->td_intr_nesting_level++; 1317 thread = 0; 1318 ret = 0; 1319 critical_enter(); 1320 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1321 if (ih->ih_filter == NULL) { 1322 thread = 1; 1323 continue; 1324 } 1325 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__, 1326 ih->ih_filter, ih->ih_argument == NULL ? frame : 1327 ih->ih_argument, ih->ih_name); 1328 if (ih->ih_argument == NULL) 1329 ret = ih->ih_filter(frame); 1330 else 1331 ret = ih->ih_filter(ih->ih_argument); 1332 /* 1333 * Wrapper handler special handling: 1334 * 1335 * in some particular cases (like pccard and pccbb), 1336 * the _real_ device handler is wrapped in a couple of 1337 * functions - a filter wrapper and an ithread wrapper. 1338 * In this case (and just in this case), the filter wrapper 1339 * could ask the system to schedule the ithread and mask 1340 * the interrupt source if the wrapped handler is composed 1341 * of just an ithread handler. 1342 * 1343 * TODO: write a generic wrapper to avoid people rolling 1344 * their own 1345 */ 1346 if (!thread) { 1347 if (ret == FILTER_SCHEDULE_THREAD) 1348 thread = 1; 1349 } 1350 } 1351 1352 if (thread) { 1353 if (ie->ie_pre_ithread != NULL) 1354 ie->ie_pre_ithread(ie->ie_source); 1355 } else { 1356 if (ie->ie_post_filter != NULL) 1357 ie->ie_post_filter(ie->ie_source); 1358 } 1359 1360 /* Schedule the ithread if needed. */ 1361 if (thread) { 1362 error = intr_event_schedule_thread(ie); 1363 KASSERT(error == 0, ("bad stray interrupt")); 1364 } 1365 critical_exit(); 1366 td->td_intr_nesting_level--; 1367 return (0); 1368 } 1369 #else 1370 /* 1371 * This is the main code for interrupt threads. 1372 */ 1373 static void 1374 ithread_loop(void *arg) 1375 { 1376 struct intr_thread *ithd; 1377 struct intr_handler *ih; 1378 struct intr_event *ie; 1379 struct thread *td; 1380 struct proc *p; 1381 int priv; 1382 1383 td = curthread; 1384 p = td->td_proc; 1385 ih = (struct intr_handler *)arg; 1386 priv = (ih->ih_thread != NULL) ? 1 : 0; 1387 ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread; 1388 KASSERT(ithd->it_thread == td, 1389 ("%s: ithread and proc linkage out of sync", __func__)); 1390 ie = ithd->it_event; 1391 ie->ie_count = 0; 1392 1393 /* 1394 * As long as we have interrupts outstanding, go through the 1395 * list of handlers, giving each one a go at it. 1396 */ 1397 for (;;) { 1398 /* 1399 * If we are an orphaned thread, then just die. 1400 */ 1401 if (ithd->it_flags & IT_DEAD) { 1402 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1403 p->p_pid, p->p_comm); 1404 free(ithd, M_ITHREAD); 1405 kthread_exit(0); 1406 } 1407 1408 /* 1409 * Service interrupts. If another interrupt arrives while 1410 * we are running, it will set it_need to note that we 1411 * should make another pass. 1412 */ 1413 while (ithd->it_need) { 1414 /* 1415 * This might need a full read and write barrier 1416 * to make sure that this write posts before any 1417 * of the memory or device accesses in the 1418 * handlers. 1419 */ 1420 atomic_store_rel_int(&ithd->it_need, 0); 1421 if (priv) 1422 priv_ithread_execute_handler(p, ih); 1423 else 1424 ithread_execute_handlers(p, ie); 1425 } 1426 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1427 mtx_assert(&Giant, MA_NOTOWNED); 1428 1429 /* 1430 * Processed all our interrupts. Now get the sched 1431 * lock. This may take a while and it_need may get 1432 * set again, so we have to check it again. 1433 */ 1434 thread_lock(td); 1435 if (!ithd->it_need && !(ithd->it_flags & IT_DEAD)) { 1436 TD_SET_IWAIT(td); 1437 ie->ie_count = 0; 1438 mi_switch(SW_VOL, NULL); 1439 } 1440 thread_unlock(td); 1441 } 1442 } 1443 1444 /* 1445 * Main loop for interrupt filter. 1446 * 1447 * Some architectures (i386, amd64 and arm) require the optional frame 1448 * parameter, and use it as the main argument for fast handler execution 1449 * when ih_argument == NULL. 1450 * 1451 * Return value: 1452 * o FILTER_STRAY: No filter recognized the event, and no 1453 * filter-less handler is registered on this 1454 * line. 1455 * o FILTER_HANDLED: A filter claimed the event and served it. 1456 * o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at 1457 * least one filter-less handler on this line. 1458 * o FILTER_HANDLED | 1459 * FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for 1460 * scheduling the per-handler ithread. 1461 * 1462 * In case an ithread has to be scheduled, in *ithd there will be a 1463 * pointer to a struct intr_thread containing the thread to be 1464 * scheduled. 1465 */ 1466 1467 static int 1468 intr_filter_loop(struct intr_event *ie, struct trapframe *frame, 1469 struct intr_thread **ithd) 1470 { 1471 struct intr_handler *ih; 1472 void *arg; 1473 int ret, thread_only; 1474 1475 ret = 0; 1476 thread_only = 0; 1477 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1478 /* 1479 * Execute fast interrupt handlers directly. 1480 * To support clock handlers, if a handler registers 1481 * with a NULL argument, then we pass it a pointer to 1482 * a trapframe as its argument. 1483 */ 1484 arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument); 1485 1486 CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__, 1487 ih->ih_filter, ih->ih_handler, arg, ih->ih_name); 1488 1489 if (ih->ih_filter != NULL) 1490 ret = ih->ih_filter(arg); 1491 else { 1492 thread_only = 1; 1493 continue; 1494 } 1495 1496 if (ret & FILTER_STRAY) 1497 continue; 1498 else { 1499 *ithd = ih->ih_thread; 1500 return (ret); 1501 } 1502 } 1503 1504 /* 1505 * No filters handled the interrupt and we have at least 1506 * one handler without a filter. In this case, we schedule 1507 * all of the filter-less handlers to run in the ithread. 1508 */ 1509 if (thread_only) { 1510 *ithd = ie->ie_thread; 1511 return (FILTER_SCHEDULE_THREAD); 1512 } 1513 return (FILTER_STRAY); 1514 } 1515 1516 /* 1517 * Main interrupt handling body. 1518 * 1519 * Input: 1520 * o ie: the event connected to this interrupt. 1521 * o frame: some archs (i.e. i386) pass a frame to some. 1522 * handlers as their main argument. 1523 * Return value: 1524 * o 0: everything ok. 1525 * o EINVAL: stray interrupt. 1526 */ 1527 int 1528 intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1529 { 1530 struct intr_thread *ithd; 1531 struct thread *td; 1532 int thread; 1533 1534 ithd = NULL; 1535 td = curthread; 1536 1537 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers)) 1538 return (EINVAL); 1539 1540 td->td_intr_nesting_level++; 1541 thread = 0; 1542 critical_enter(); 1543 thread = intr_filter_loop(ie, frame, &ithd); 1544 if (thread & FILTER_HANDLED) { 1545 if (ie->ie_post_filter != NULL) 1546 ie->ie_post_filter(ie->ie_source); 1547 } else { 1548 if (ie->ie_pre_ithread != NULL) 1549 ie->ie_pre_ithread(ie->ie_source); 1550 } 1551 critical_exit(); 1552 1553 /* Interrupt storm logic */ 1554 if (thread & FILTER_STRAY) { 1555 ie->ie_count++; 1556 if (ie->ie_count < intr_storm_threshold) 1557 printf("Interrupt stray detection not present\n"); 1558 } 1559 1560 /* Schedule an ithread if needed. */ 1561 if (thread & FILTER_SCHEDULE_THREAD) { 1562 if (intr_event_schedule_thread(ie, ithd) != 0) 1563 panic("%s: impossible stray interrupt", __func__); 1564 } 1565 td->td_intr_nesting_level--; 1566 return (0); 1567 } 1568 #endif 1569 1570 #ifdef DDB 1571 /* 1572 * Dump details about an interrupt handler 1573 */ 1574 static void 1575 db_dump_intrhand(struct intr_handler *ih) 1576 { 1577 int comma; 1578 1579 db_printf("\t%-10s ", ih->ih_name); 1580 switch (ih->ih_pri) { 1581 case PI_REALTIME: 1582 db_printf("CLK "); 1583 break; 1584 case PI_AV: 1585 db_printf("AV "); 1586 break; 1587 case PI_TTYHIGH: 1588 case PI_TTYLOW: 1589 db_printf("TTY "); 1590 break; 1591 case PI_TAPE: 1592 db_printf("TAPE"); 1593 break; 1594 case PI_NET: 1595 db_printf("NET "); 1596 break; 1597 case PI_DISK: 1598 case PI_DISKLOW: 1599 db_printf("DISK"); 1600 break; 1601 case PI_DULL: 1602 db_printf("DULL"); 1603 break; 1604 default: 1605 if (ih->ih_pri >= PI_SOFT) 1606 db_printf("SWI "); 1607 else 1608 db_printf("%4u", ih->ih_pri); 1609 break; 1610 } 1611 db_printf(" "); 1612 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC); 1613 db_printf("(%p)", ih->ih_argument); 1614 if (ih->ih_need || 1615 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD | 1616 IH_MPSAFE)) != 0) { 1617 db_printf(" {"); 1618 comma = 0; 1619 if (ih->ih_flags & IH_EXCLUSIVE) { 1620 if (comma) 1621 db_printf(", "); 1622 db_printf("EXCL"); 1623 comma = 1; 1624 } 1625 if (ih->ih_flags & IH_ENTROPY) { 1626 if (comma) 1627 db_printf(", "); 1628 db_printf("ENTROPY"); 1629 comma = 1; 1630 } 1631 if (ih->ih_flags & IH_DEAD) { 1632 if (comma) 1633 db_printf(", "); 1634 db_printf("DEAD"); 1635 comma = 1; 1636 } 1637 if (ih->ih_flags & IH_MPSAFE) { 1638 if (comma) 1639 db_printf(", "); 1640 db_printf("MPSAFE"); 1641 comma = 1; 1642 } 1643 if (ih->ih_need) { 1644 if (comma) 1645 db_printf(", "); 1646 db_printf("NEED"); 1647 } 1648 db_printf("}"); 1649 } 1650 db_printf("\n"); 1651 } 1652 1653 /* 1654 * Dump details about a event. 1655 */ 1656 void 1657 db_dump_intr_event(struct intr_event *ie, int handlers) 1658 { 1659 struct intr_handler *ih; 1660 struct intr_thread *it; 1661 int comma; 1662 1663 db_printf("%s ", ie->ie_fullname); 1664 it = ie->ie_thread; 1665 if (it != NULL) 1666 db_printf("(pid %d)", it->it_thread->td_proc->p_pid); 1667 else 1668 db_printf("(no thread)"); 1669 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 || 1670 (it != NULL && it->it_need)) { 1671 db_printf(" {"); 1672 comma = 0; 1673 if (ie->ie_flags & IE_SOFT) { 1674 db_printf("SOFT"); 1675 comma = 1; 1676 } 1677 if (ie->ie_flags & IE_ENTROPY) { 1678 if (comma) 1679 db_printf(", "); 1680 db_printf("ENTROPY"); 1681 comma = 1; 1682 } 1683 if (ie->ie_flags & IE_ADDING_THREAD) { 1684 if (comma) 1685 db_printf(", "); 1686 db_printf("ADDING_THREAD"); 1687 comma = 1; 1688 } 1689 if (it != NULL && it->it_need) { 1690 if (comma) 1691 db_printf(", "); 1692 db_printf("NEED"); 1693 } 1694 db_printf("}"); 1695 } 1696 db_printf("\n"); 1697 1698 if (handlers) 1699 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 1700 db_dump_intrhand(ih); 1701 } 1702 1703 /* 1704 * Dump data about interrupt handlers 1705 */ 1706 DB_SHOW_COMMAND(intr, db_show_intr) 1707 { 1708 struct intr_event *ie; 1709 int all, verbose; 1710 1711 verbose = index(modif, 'v') != NULL; 1712 all = index(modif, 'a') != NULL; 1713 TAILQ_FOREACH(ie, &event_list, ie_list) { 1714 if (!all && TAILQ_EMPTY(&ie->ie_handlers)) 1715 continue; 1716 db_dump_intr_event(ie, verbose); 1717 if (db_pager_quit) 1718 break; 1719 } 1720 } 1721 #endif /* DDB */ 1722 1723 /* 1724 * Start standard software interrupt threads 1725 */ 1726 static void 1727 start_softintr(void *dummy) 1728 { 1729 struct proc *p; 1730 1731 if (swi_add(&clk_intr_event, "clock", softclock, NULL, SWI_CLOCK, 1732 INTR_MPSAFE, &softclock_ih) || 1733 swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih)) 1734 panic("died while creating standard software ithreads"); 1735 1736 p = clk_intr_event->ie_thread->it_thread->td_proc; 1737 PROC_LOCK(p); 1738 p->p_flag |= P_NOLOAD; 1739 PROC_UNLOCK(p); 1740 } 1741 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, 1742 NULL); 1743 1744 /* 1745 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. 1746 * The data for this machine dependent, and the declarations are in machine 1747 * dependent code. The layout of intrnames and intrcnt however is machine 1748 * independent. 1749 * 1750 * We do not know the length of intrcnt and intrnames at compile time, so 1751 * calculate things at run time. 1752 */ 1753 static int 1754 sysctl_intrnames(SYSCTL_HANDLER_ARGS) 1755 { 1756 return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames, 1757 req)); 1758 } 1759 1760 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD, 1761 NULL, 0, sysctl_intrnames, "", "Interrupt Names"); 1762 1763 static int 1764 sysctl_intrcnt(SYSCTL_HANDLER_ARGS) 1765 { 1766 return (sysctl_handle_opaque(oidp, intrcnt, 1767 (char *)eintrcnt - (char *)intrcnt, req)); 1768 } 1769 1770 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD, 1771 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts"); 1772 1773 #ifdef DDB 1774 /* 1775 * DDB command to dump the interrupt statistics. 1776 */ 1777 DB_SHOW_COMMAND(intrcnt, db_show_intrcnt) 1778 { 1779 u_long *i; 1780 char *cp; 1781 1782 cp = intrnames; 1783 for (i = intrcnt; i != eintrcnt && !db_pager_quit; i++) { 1784 if (*cp == '\0') 1785 break; 1786 if (*i != 0) 1787 db_printf("%s\t%lu\n", cp, *i); 1788 cp += strlen(cp) + 1; 1789 } 1790 } 1791 #endif
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