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