kern_intr.c revision 272946
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: stable/10/sys/kern/kern_intr.c 272946 2014-10-11 17:49:51Z kib $"); 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 */ 69struct 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 80struct intr_entropy { 81 struct thread *td; 82 uintptr_t event; 83}; 84 85struct intr_event *clk_intr_event; 86struct intr_event *tty_intr_event; 87void *vm_ih; 88struct proc *intrproc; 89 90static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads"); 91 92static int intr_storm_threshold = 1000; 93TUNABLE_INT("hw.intr_storm_threshold", &intr_storm_threshold); 94SYSCTL_INT(_hw, OID_AUTO, intr_storm_threshold, CTLFLAG_RW, 95 &intr_storm_threshold, 0, 96 "Number of consecutive interrupts before storm protection is enabled"); 97static TAILQ_HEAD(, intr_event) event_list = 98 TAILQ_HEAD_INITIALIZER(event_list); 99static struct mtx event_lock; 100MTX_SYSINIT(intr_event_list, &event_lock, "intr event list", MTX_DEF); 101 102static void intr_event_update(struct intr_event *ie); 103#ifdef INTR_FILTER 104static int intr_event_schedule_thread(struct intr_event *ie, 105 struct intr_thread *ithd); 106static int intr_filter_loop(struct intr_event *ie, 107 struct trapframe *frame, struct intr_thread **ithd); 108static struct intr_thread *ithread_create(const char *name, 109 struct intr_handler *ih); 110#else 111static int intr_event_schedule_thread(struct intr_event *ie); 112static struct intr_thread *ithread_create(const char *name); 113#endif 114static void ithread_destroy(struct intr_thread *ithread); 115static void ithread_execute_handlers(struct proc *p, 116 struct intr_event *ie); 117#ifdef INTR_FILTER 118static void priv_ithread_execute_handler(struct proc *p, 119 struct intr_handler *ih); 120#endif 121static void ithread_loop(void *); 122static void ithread_update(struct intr_thread *ithd); 123static void start_softintr(void *); 124 125/* Map an interrupt type to an ithread priority. */ 126u_char 127intr_priority(enum intr_type flags) 128{ 129 u_char pri; 130 131 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET | 132 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV); 133 switch (flags) { 134 case INTR_TYPE_TTY: 135 pri = PI_TTY; 136 break; 137 case INTR_TYPE_BIO: 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; 145 break; 146 case INTR_TYPE_AV: 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 */ 166static void 167ithread_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_name, ie->ie_fullname, sizeof(td->td_name)); 184#ifdef KTR 185 sched_clear_tdname(td); 186#endif 187 thread_lock(td); 188 sched_prio(td, pri); 189 thread_unlock(td); 190} 191 192/* 193 * Regenerate the full name of an interrupt event and update its priority. 194 */ 195static void 196intr_event_update(struct intr_event *ie) 197{ 198 struct intr_handler *ih; 199 char *last; 200 int missed, space; 201 202 /* Start off with no entropy and just the name of the event. */ 203 mtx_assert(&ie->ie_lock, MA_OWNED); 204 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 205 ie->ie_flags &= ~IE_ENTROPY; 206 missed = 0; 207 space = 1; 208 209 /* Run through all the handlers updating values. */ 210 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 211 if (strlen(ie->ie_fullname) + strlen(ih->ih_name) + 1 < 212 sizeof(ie->ie_fullname)) { 213 strcat(ie->ie_fullname, " "); 214 strcat(ie->ie_fullname, ih->ih_name); 215 space = 0; 216 } else 217 missed++; 218 if (ih->ih_flags & IH_ENTROPY) 219 ie->ie_flags |= IE_ENTROPY; 220 } 221 222 /* 223 * If the handler names were too long, add +'s to indicate missing 224 * names. If we run out of room and still have +'s to add, change 225 * the last character from a + to a *. 226 */ 227 last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2]; 228 while (missed-- > 0) { 229 if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) { 230 if (*last == '+') { 231 *last = '*'; 232 break; 233 } else 234 *last = '+'; 235 } else if (space) { 236 strcat(ie->ie_fullname, " +"); 237 space = 0; 238 } else 239 strcat(ie->ie_fullname, "+"); 240 } 241 242 /* 243 * If this event has an ithread, update it's priority and 244 * name. 245 */ 246 if (ie->ie_thread != NULL) 247 ithread_update(ie->ie_thread); 248 CTR2(KTR_INTR, "%s: updated %s", __func__, ie->ie_fullname); 249} 250 251int 252intr_event_create(struct intr_event **event, void *source, int flags, int irq, 253 void (*pre_ithread)(void *), void (*post_ithread)(void *), 254 void (*post_filter)(void *), int (*assign_cpu)(void *, u_char), 255 const char *fmt, ...) 256{ 257 struct intr_event *ie; 258 va_list ap; 259 260 /* The only valid flag during creation is IE_SOFT. */ 261 if ((flags & ~IE_SOFT) != 0) 262 return (EINVAL); 263 ie = malloc(sizeof(struct intr_event), M_ITHREAD, M_WAITOK | M_ZERO); 264 ie->ie_source = source; 265 ie->ie_pre_ithread = pre_ithread; 266 ie->ie_post_ithread = post_ithread; 267 ie->ie_post_filter = post_filter; 268 ie->ie_assign_cpu = assign_cpu; 269 ie->ie_flags = flags; 270 ie->ie_irq = irq; 271 ie->ie_cpu = NOCPU; 272 TAILQ_INIT(&ie->ie_handlers); 273 mtx_init(&ie->ie_lock, "intr event", NULL, MTX_DEF); 274 275 va_start(ap, fmt); 276 vsnprintf(ie->ie_name, sizeof(ie->ie_name), fmt, ap); 277 va_end(ap); 278 strlcpy(ie->ie_fullname, ie->ie_name, sizeof(ie->ie_fullname)); 279 mtx_lock(&event_lock); 280 TAILQ_INSERT_TAIL(&event_list, ie, ie_list); 281 mtx_unlock(&event_lock); 282 if (event != NULL) 283 *event = ie; 284 CTR2(KTR_INTR, "%s: created %s", __func__, ie->ie_name); 285 return (0); 286} 287 288/* 289 * Bind an interrupt event to the specified CPU. Note that not all 290 * platforms support binding an interrupt to a CPU. For those 291 * platforms this request will fail. For supported platforms, any 292 * associated ithreads as well as the primary interrupt context will 293 * be bound to the specificed CPU. Using a cpu id of NOCPU unbinds 294 * the interrupt event. 295 */ 296int 297intr_event_bind(struct intr_event *ie, u_char cpu) 298{ 299 cpuset_t mask; 300 lwpid_t id; 301 int error; 302 303 /* Need a CPU to bind to. */ 304 if (cpu != NOCPU && CPU_ABSENT(cpu)) 305 return (EINVAL); 306 307 if (ie->ie_assign_cpu == NULL) 308 return (EOPNOTSUPP); 309 310 error = priv_check(curthread, PRIV_SCHED_CPUSET_INTR); 311 if (error) 312 return (error); 313 314 /* 315 * If we have any ithreads try to set their mask first to verify 316 * permissions, etc. 317 */ 318 mtx_lock(&ie->ie_lock); 319 if (ie->ie_thread != NULL) { 320 CPU_ZERO(&mask); 321 if (cpu == NOCPU) 322 CPU_COPY(cpuset_root, &mask); 323 else 324 CPU_SET(cpu, &mask); 325 id = ie->ie_thread->it_thread->td_tid; 326 mtx_unlock(&ie->ie_lock); 327 error = cpuset_setthread(id, &mask); 328 if (error) 329 return (error); 330 } else 331 mtx_unlock(&ie->ie_lock); 332 error = ie->ie_assign_cpu(ie->ie_source, cpu); 333 if (error) { 334 mtx_lock(&ie->ie_lock); 335 if (ie->ie_thread != NULL) { 336 CPU_ZERO(&mask); 337 if (ie->ie_cpu == NOCPU) 338 CPU_COPY(cpuset_root, &mask); 339 else 340 CPU_SET(ie->ie_cpu, &mask); 341 id = ie->ie_thread->it_thread->td_tid; 342 mtx_unlock(&ie->ie_lock); 343 (void)cpuset_setthread(id, &mask); 344 } else 345 mtx_unlock(&ie->ie_lock); 346 return (error); 347 } 348 349 mtx_lock(&ie->ie_lock); 350 ie->ie_cpu = cpu; 351 mtx_unlock(&ie->ie_lock); 352 353 return (error); 354} 355 356static struct intr_event * 357intr_lookup(int irq) 358{ 359 struct intr_event *ie; 360 361 mtx_lock(&event_lock); 362 TAILQ_FOREACH(ie, &event_list, ie_list) 363 if (ie->ie_irq == irq && 364 (ie->ie_flags & IE_SOFT) == 0 && 365 TAILQ_FIRST(&ie->ie_handlers) != NULL) 366 break; 367 mtx_unlock(&event_lock); 368 return (ie); 369} 370 371int 372intr_setaffinity(int irq, void *m) 373{ 374 struct intr_event *ie; 375 cpuset_t *mask; 376 u_char cpu; 377 int n; 378 379 mask = m; 380 cpu = NOCPU; 381 /* 382 * If we're setting all cpus we can unbind. Otherwise make sure 383 * only one cpu is in the set. 384 */ 385 if (CPU_CMP(cpuset_root, mask)) { 386 for (n = 0; n < CPU_SETSIZE; n++) { 387 if (!CPU_ISSET(n, mask)) 388 continue; 389 if (cpu != NOCPU) 390 return (EINVAL); 391 cpu = (u_char)n; 392 } 393 } 394 ie = intr_lookup(irq); 395 if (ie == NULL) 396 return (ESRCH); 397 return (intr_event_bind(ie, cpu)); 398} 399 400int 401intr_getaffinity(int irq, void *m) 402{ 403 struct intr_event *ie; 404 cpuset_t *mask; 405 406 mask = m; 407 ie = intr_lookup(irq); 408 if (ie == NULL) 409 return (ESRCH); 410 CPU_ZERO(mask); 411 mtx_lock(&ie->ie_lock); 412 if (ie->ie_cpu == NOCPU) 413 CPU_COPY(cpuset_root, mask); 414 else 415 CPU_SET(ie->ie_cpu, mask); 416 mtx_unlock(&ie->ie_lock); 417 return (0); 418} 419 420int 421intr_event_destroy(struct intr_event *ie) 422{ 423 424 mtx_lock(&event_lock); 425 mtx_lock(&ie->ie_lock); 426 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 427 mtx_unlock(&ie->ie_lock); 428 mtx_unlock(&event_lock); 429 return (EBUSY); 430 } 431 TAILQ_REMOVE(&event_list, ie, ie_list); 432#ifndef notyet 433 if (ie->ie_thread != NULL) { 434 ithread_destroy(ie->ie_thread); 435 ie->ie_thread = NULL; 436 } 437#endif 438 mtx_unlock(&ie->ie_lock); 439 mtx_unlock(&event_lock); 440 mtx_destroy(&ie->ie_lock); 441 free(ie, M_ITHREAD); 442 return (0); 443} 444 445#ifndef INTR_FILTER 446static struct intr_thread * 447ithread_create(const char *name) 448{ 449 struct intr_thread *ithd; 450 struct thread *td; 451 int error; 452 453 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 454 455 error = kproc_kthread_add(ithread_loop, ithd, &intrproc, 456 &td, RFSTOPPED | RFHIGHPID, 457 0, "intr", "%s", name); 458 if (error) 459 panic("kproc_create() failed with %d", error); 460 thread_lock(td); 461 sched_class(td, PRI_ITHD); 462 TD_SET_IWAIT(td); 463 thread_unlock(td); 464 td->td_pflags |= TDP_ITHREAD; 465 ithd->it_thread = td; 466 CTR2(KTR_INTR, "%s: created %s", __func__, name); 467 return (ithd); 468} 469#else 470static struct intr_thread * 471ithread_create(const char *name, struct intr_handler *ih) 472{ 473 struct intr_thread *ithd; 474 struct thread *td; 475 int error; 476 477 ithd = malloc(sizeof(struct intr_thread), M_ITHREAD, M_WAITOK | M_ZERO); 478 479 error = kproc_kthread_add(ithread_loop, ih, &intrproc, 480 &td, RFSTOPPED | RFHIGHPID, 481 0, "intr", "%s", name); 482 if (error) 483 panic("kproc_create() failed with %d", error); 484 thread_lock(td); 485 sched_class(td, PRI_ITHD); 486 TD_SET_IWAIT(td); 487 thread_unlock(td); 488 td->td_pflags |= TDP_ITHREAD; 489 ithd->it_thread = td; 490 CTR2(KTR_INTR, "%s: created %s", __func__, name); 491 return (ithd); 492} 493#endif 494 495static void 496ithread_destroy(struct intr_thread *ithread) 497{ 498 struct thread *td; 499 500 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_event->ie_name); 501 td = ithread->it_thread; 502 thread_lock(td); 503 ithread->it_flags |= IT_DEAD; 504 if (TD_AWAITING_INTR(td)) { 505 TD_CLR_IWAIT(td); 506 sched_add(td, SRQ_INTR); 507 } 508 thread_unlock(td); 509} 510 511#ifndef INTR_FILTER 512int 513intr_event_add_handler(struct intr_event *ie, const char *name, 514 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 515 enum intr_type flags, void **cookiep) 516{ 517 struct intr_handler *ih, *temp_ih; 518 struct intr_thread *it; 519 520 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 521 return (EINVAL); 522 523 /* Allocate and populate an interrupt handler structure. */ 524 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 525 ih->ih_filter = filter; 526 ih->ih_handler = handler; 527 ih->ih_argument = arg; 528 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 529 ih->ih_event = ie; 530 ih->ih_pri = pri; 531 if (flags & INTR_EXCL) 532 ih->ih_flags = IH_EXCLUSIVE; 533 if (flags & INTR_MPSAFE) 534 ih->ih_flags |= IH_MPSAFE; 535 if (flags & INTR_ENTROPY) 536 ih->ih_flags |= IH_ENTROPY; 537 538 /* We can only have one exclusive handler in a event. */ 539 mtx_lock(&ie->ie_lock); 540 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 541 if ((flags & INTR_EXCL) || 542 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 543 mtx_unlock(&ie->ie_lock); 544 free(ih, M_ITHREAD); 545 return (EINVAL); 546 } 547 } 548 549 /* Create a thread if we need one. */ 550 while (ie->ie_thread == NULL && handler != NULL) { 551 if (ie->ie_flags & IE_ADDING_THREAD) 552 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 553 else { 554 ie->ie_flags |= IE_ADDING_THREAD; 555 mtx_unlock(&ie->ie_lock); 556 it = ithread_create("intr: newborn"); 557 mtx_lock(&ie->ie_lock); 558 ie->ie_flags &= ~IE_ADDING_THREAD; 559 ie->ie_thread = it; 560 it->it_event = ie; 561 ithread_update(it); 562 wakeup(ie); 563 } 564 } 565 566 /* Add the new handler to the event in priority order. */ 567 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) { 568 if (temp_ih->ih_pri > ih->ih_pri) 569 break; 570 } 571 if (temp_ih == NULL) 572 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next); 573 else 574 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 575 intr_event_update(ie); 576 577 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 578 ie->ie_name); 579 mtx_unlock(&ie->ie_lock); 580 581 if (cookiep != NULL) 582 *cookiep = ih; 583 return (0); 584} 585#else 586int 587intr_event_add_handler(struct intr_event *ie, const char *name, 588 driver_filter_t filter, driver_intr_t handler, void *arg, u_char pri, 589 enum intr_type flags, void **cookiep) 590{ 591 struct intr_handler *ih, *temp_ih; 592 struct intr_thread *it; 593 594 if (ie == NULL || name == NULL || (handler == NULL && filter == NULL)) 595 return (EINVAL); 596 597 /* Allocate and populate an interrupt handler structure. */ 598 ih = malloc(sizeof(struct intr_handler), M_ITHREAD, M_WAITOK | M_ZERO); 599 ih->ih_filter = filter; 600 ih->ih_handler = handler; 601 ih->ih_argument = arg; 602 strlcpy(ih->ih_name, name, sizeof(ih->ih_name)); 603 ih->ih_event = ie; 604 ih->ih_pri = pri; 605 if (flags & INTR_EXCL) 606 ih->ih_flags = IH_EXCLUSIVE; 607 if (flags & INTR_MPSAFE) 608 ih->ih_flags |= IH_MPSAFE; 609 if (flags & INTR_ENTROPY) 610 ih->ih_flags |= IH_ENTROPY; 611 612 /* We can only have one exclusive handler in a event. */ 613 mtx_lock(&ie->ie_lock); 614 if (!TAILQ_EMPTY(&ie->ie_handlers)) { 615 if ((flags & INTR_EXCL) || 616 (TAILQ_FIRST(&ie->ie_handlers)->ih_flags & IH_EXCLUSIVE)) { 617 mtx_unlock(&ie->ie_lock); 618 free(ih, M_ITHREAD); 619 return (EINVAL); 620 } 621 } 622 623 /* For filtered handlers, create a private ithread to run on. */ 624 if (filter != NULL && handler != NULL) { 625 mtx_unlock(&ie->ie_lock); 626 it = ithread_create("intr: newborn", ih); 627 mtx_lock(&ie->ie_lock); 628 it->it_event = ie; 629 ih->ih_thread = it; 630 ithread_update(it); /* XXX - do we really need this?!?!? */ 631 } else { /* Create the global per-event thread if we need one. */ 632 while (ie->ie_thread == NULL && handler != NULL) { 633 if (ie->ie_flags & IE_ADDING_THREAD) 634 msleep(ie, &ie->ie_lock, 0, "ithread", 0); 635 else { 636 ie->ie_flags |= IE_ADDING_THREAD; 637 mtx_unlock(&ie->ie_lock); 638 it = ithread_create("intr: newborn", ih); 639 mtx_lock(&ie->ie_lock); 640 ie->ie_flags &= ~IE_ADDING_THREAD; 641 ie->ie_thread = it; 642 it->it_event = ie; 643 ithread_update(it); 644 wakeup(ie); 645 } 646 } 647 } 648 649 /* Add the new handler to the event in priority order. */ 650 TAILQ_FOREACH(temp_ih, &ie->ie_handlers, ih_next) { 651 if (temp_ih->ih_pri > ih->ih_pri) 652 break; 653 } 654 if (temp_ih == NULL) 655 TAILQ_INSERT_TAIL(&ie->ie_handlers, ih, ih_next); 656 else 657 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 658 intr_event_update(ie); 659 660 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 661 ie->ie_name); 662 mtx_unlock(&ie->ie_lock); 663 664 if (cookiep != NULL) 665 *cookiep = ih; 666 return (0); 667} 668#endif 669 670/* 671 * Append a description preceded by a ':' to the name of the specified 672 * interrupt handler. 673 */ 674int 675intr_event_describe_handler(struct intr_event *ie, void *cookie, 676 const char *descr) 677{ 678 struct intr_handler *ih; 679 size_t space; 680 char *start; 681 682 mtx_lock(&ie->ie_lock); 683#ifdef INVARIANTS 684 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 685 if (ih == cookie) 686 break; 687 } 688 if (ih == NULL) { 689 mtx_unlock(&ie->ie_lock); 690 panic("handler %p not found in interrupt event %p", cookie, ie); 691 } 692#endif 693 ih = cookie; 694 695 /* 696 * Look for an existing description by checking for an 697 * existing ":". This assumes device names do not include 698 * colons. If one is found, prepare to insert the new 699 * description at that point. If one is not found, find the 700 * end of the name to use as the insertion point. 701 */ 702 start = strchr(ih->ih_name, ':'); 703 if (start == NULL) 704 start = strchr(ih->ih_name, 0); 705 706 /* 707 * See if there is enough remaining room in the string for the 708 * description + ":". The "- 1" leaves room for the trailing 709 * '\0'. The "+ 1" accounts for the colon. 710 */ 711 space = sizeof(ih->ih_name) - (start - ih->ih_name) - 1; 712 if (strlen(descr) + 1 > space) { 713 mtx_unlock(&ie->ie_lock); 714 return (ENOSPC); 715 } 716 717 /* Append a colon followed by the description. */ 718 *start = ':'; 719 strcpy(start + 1, descr); 720 intr_event_update(ie); 721 mtx_unlock(&ie->ie_lock); 722 return (0); 723} 724 725/* 726 * Return the ie_source field from the intr_event an intr_handler is 727 * associated with. 728 */ 729void * 730intr_handler_source(void *cookie) 731{ 732 struct intr_handler *ih; 733 struct intr_event *ie; 734 735 ih = (struct intr_handler *)cookie; 736 if (ih == NULL) 737 return (NULL); 738 ie = ih->ih_event; 739 KASSERT(ie != NULL, 740 ("interrupt handler \"%s\" has a NULL interrupt event", 741 ih->ih_name)); 742 return (ie->ie_source); 743} 744 745/* 746 * Sleep until an ithread finishes executing an interrupt handler. 747 * 748 * XXX Doesn't currently handle interrupt filters or fast interrupt 749 * handlers. This is intended for compatibility with linux drivers 750 * only. Do not use in BSD code. 751 */ 752void 753_intr_drain(int irq) 754{ 755 struct intr_event *ie; 756 struct intr_thread *ithd; 757 struct thread *td; 758 759 ie = intr_lookup(irq); 760 if (ie == NULL) 761 return; 762 if (ie->ie_thread == NULL) 763 return; 764 ithd = ie->ie_thread; 765 td = ithd->it_thread; 766 /* 767 * We set the flag and wait for it to be cleared to avoid 768 * long delays with potentially busy interrupt handlers 769 * were we to only sample TD_AWAITING_INTR() every tick. 770 */ 771 thread_lock(td); 772 if (!TD_AWAITING_INTR(td)) { 773 ithd->it_flags |= IT_WAIT; 774 while (ithd->it_flags & IT_WAIT) { 775 thread_unlock(td); 776 pause("idrain", 1); 777 thread_lock(td); 778 } 779 } 780 thread_unlock(td); 781 return; 782} 783 784 785#ifndef INTR_FILTER 786int 787intr_event_remove_handler(void *cookie) 788{ 789 struct intr_handler *handler = (struct intr_handler *)cookie; 790 struct intr_event *ie; 791#ifdef INVARIANTS 792 struct intr_handler *ih; 793#endif 794#ifdef notyet 795 int dead; 796#endif 797 798 if (handler == NULL) 799 return (EINVAL); 800 ie = handler->ih_event; 801 KASSERT(ie != NULL, 802 ("interrupt handler \"%s\" has a NULL interrupt event", 803 handler->ih_name)); 804 mtx_lock(&ie->ie_lock); 805 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 806 ie->ie_name); 807#ifdef INVARIANTS 808 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 809 if (ih == handler) 810 goto ok; 811 mtx_unlock(&ie->ie_lock); 812 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"", 813 ih->ih_name, ie->ie_name); 814ok: 815#endif 816 /* 817 * If there is no ithread, then just remove the handler and return. 818 * XXX: Note that an INTR_FAST handler might be running on another 819 * CPU! 820 */ 821 if (ie->ie_thread == NULL) { 822 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 823 mtx_unlock(&ie->ie_lock); 824 free(handler, M_ITHREAD); 825 return (0); 826 } 827 828 /* 829 * If the interrupt thread is already running, then just mark this 830 * handler as being dead and let the ithread do the actual removal. 831 * 832 * During a cold boot while cold is set, msleep() does not sleep, 833 * so we have to remove the handler here rather than letting the 834 * thread do it. 835 */ 836 thread_lock(ie->ie_thread->it_thread); 837 if (!TD_AWAITING_INTR(ie->ie_thread->it_thread) && !cold) { 838 handler->ih_flags |= IH_DEAD; 839 840 /* 841 * Ensure that the thread will process the handler list 842 * again and remove this handler if it has already passed 843 * it on the list. 844 */ 845 atomic_store_rel_int(&ie->ie_thread->it_need, 1); 846 } else 847 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 848 thread_unlock(ie->ie_thread->it_thread); 849 while (handler->ih_flags & IH_DEAD) 850 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 851 intr_event_update(ie); 852#ifdef notyet 853 /* 854 * XXX: This could be bad in the case of ppbus(8). Also, I think 855 * this could lead to races of stale data when servicing an 856 * interrupt. 857 */ 858 dead = 1; 859 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 860 if (!(ih->ih_flags & IH_FAST)) { 861 dead = 0; 862 break; 863 } 864 } 865 if (dead) { 866 ithread_destroy(ie->ie_thread); 867 ie->ie_thread = NULL; 868 } 869#endif 870 mtx_unlock(&ie->ie_lock); 871 free(handler, M_ITHREAD); 872 return (0); 873} 874 875static int 876intr_event_schedule_thread(struct intr_event *ie) 877{ 878 struct intr_entropy entropy; 879 struct intr_thread *it; 880 struct thread *td; 881 struct thread *ctd; 882 struct proc *p; 883 884 /* 885 * If no ithread or no handlers, then we have a stray interrupt. 886 */ 887 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || 888 ie->ie_thread == NULL) 889 return (EINVAL); 890 891 ctd = curthread; 892 it = ie->ie_thread; 893 td = it->it_thread; 894 p = td->td_proc; 895 896 /* 897 * If any of the handlers for this ithread claim to be good 898 * sources of entropy, then gather some. 899 */ 900 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) { 901 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__, 902 p->p_pid, td->td_name); 903 entropy.event = (uintptr_t)ie; 904 entropy.td = ctd; 905 random_harvest(&entropy, sizeof(entropy), 2, 906 RANDOM_INTERRUPT); 907 } 908 909 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name)); 910 911 /* 912 * Set it_need to tell the thread to keep running if it is already 913 * running. Then, lock the thread and see if we actually need to 914 * put it on the runqueue. 915 */ 916 atomic_store_rel_int(&it->it_need, 1); 917 thread_lock(td); 918 if (TD_AWAITING_INTR(td)) { 919 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid, 920 td->td_name); 921 TD_CLR_IWAIT(td); 922 sched_add(td, SRQ_INTR); 923 } else { 924 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 925 __func__, p->p_pid, td->td_name, it->it_need, td->td_state); 926 } 927 thread_unlock(td); 928 929 return (0); 930} 931#else 932int 933intr_event_remove_handler(void *cookie) 934{ 935 struct intr_handler *handler = (struct intr_handler *)cookie; 936 struct intr_event *ie; 937 struct intr_thread *it; 938#ifdef INVARIANTS 939 struct intr_handler *ih; 940#endif 941#ifdef notyet 942 int dead; 943#endif 944 945 if (handler == NULL) 946 return (EINVAL); 947 ie = handler->ih_event; 948 KASSERT(ie != NULL, 949 ("interrupt handler \"%s\" has a NULL interrupt event", 950 handler->ih_name)); 951 mtx_lock(&ie->ie_lock); 952 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 953 ie->ie_name); 954#ifdef INVARIANTS 955 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 956 if (ih == handler) 957 goto ok; 958 mtx_unlock(&ie->ie_lock); 959 panic("interrupt handler \"%s\" not found in interrupt event \"%s\"", 960 ih->ih_name, ie->ie_name); 961ok: 962#endif 963 /* 964 * If there are no ithreads (per event and per handler), then 965 * just remove the handler and return. 966 * XXX: Note that an INTR_FAST handler might be running on another CPU! 967 */ 968 if (ie->ie_thread == NULL && handler->ih_thread == NULL) { 969 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 970 mtx_unlock(&ie->ie_lock); 971 free(handler, M_ITHREAD); 972 return (0); 973 } 974 975 /* Private or global ithread? */ 976 it = (handler->ih_thread) ? handler->ih_thread : ie->ie_thread; 977 /* 978 * If the interrupt thread is already running, then just mark this 979 * handler as being dead and let the ithread do the actual removal. 980 * 981 * During a cold boot while cold is set, msleep() does not sleep, 982 * so we have to remove the handler here rather than letting the 983 * thread do it. 984 */ 985 thread_lock(it->it_thread); 986 if (!TD_AWAITING_INTR(it->it_thread) && !cold) { 987 handler->ih_flags |= IH_DEAD; 988 989 /* 990 * Ensure that the thread will process the handler list 991 * again and remove this handler if it has already passed 992 * it on the list. 993 */ 994 atomic_store_rel_int(&it->it_need, 1); 995 } else 996 TAILQ_REMOVE(&ie->ie_handlers, handler, ih_next); 997 thread_unlock(it->it_thread); 998 while (handler->ih_flags & IH_DEAD) 999 msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); 1000 /* 1001 * At this point, the handler has been disconnected from the event, 1002 * so we can kill the private ithread if any. 1003 */ 1004 if (handler->ih_thread) { 1005 ithread_destroy(handler->ih_thread); 1006 handler->ih_thread = NULL; 1007 } 1008 intr_event_update(ie); 1009#ifdef notyet 1010 /* 1011 * XXX: This could be bad in the case of ppbus(8). Also, I think 1012 * this could lead to races of stale data when servicing an 1013 * interrupt. 1014 */ 1015 dead = 1; 1016 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1017 if (handler != NULL) { 1018 dead = 0; 1019 break; 1020 } 1021 } 1022 if (dead) { 1023 ithread_destroy(ie->ie_thread); 1024 ie->ie_thread = NULL; 1025 } 1026#endif 1027 mtx_unlock(&ie->ie_lock); 1028 free(handler, M_ITHREAD); 1029 return (0); 1030} 1031 1032static int 1033intr_event_schedule_thread(struct intr_event *ie, struct intr_thread *it) 1034{ 1035 struct intr_entropy entropy; 1036 struct thread *td; 1037 struct thread *ctd; 1038 struct proc *p; 1039 1040 /* 1041 * If no ithread or no handlers, then we have a stray interrupt. 1042 */ 1043 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers) || it == NULL) 1044 return (EINVAL); 1045 1046 ctd = curthread; 1047 td = it->it_thread; 1048 p = td->td_proc; 1049 1050 /* 1051 * If any of the handlers for this ithread claim to be good 1052 * sources of entropy, then gather some. 1053 */ 1054 if (harvest.interrupt && ie->ie_flags & IE_ENTROPY) { 1055 CTR3(KTR_INTR, "%s: pid %d (%s) gathering entropy", __func__, 1056 p->p_pid, td->td_name); 1057 entropy.event = (uintptr_t)ie; 1058 entropy.td = ctd; 1059 random_harvest(&entropy, sizeof(entropy), 2, 1060 RANDOM_INTERRUPT); 1061 } 1062 1063 KASSERT(p != NULL, ("ithread %s has no process", ie->ie_name)); 1064 1065 /* 1066 * Set it_need to tell the thread to keep running if it is already 1067 * running. Then, lock the thread and see if we actually need to 1068 * put it on the runqueue. 1069 */ 1070 atomic_store_rel_int(&it->it_need, 1); 1071 thread_lock(td); 1072 if (TD_AWAITING_INTR(td)) { 1073 CTR3(KTR_INTR, "%s: schedule pid %d (%s)", __func__, p->p_pid, 1074 td->td_name); 1075 TD_CLR_IWAIT(td); 1076 sched_add(td, SRQ_INTR); 1077 } else { 1078 CTR5(KTR_INTR, "%s: pid %d (%s): it_need %d, state %d", 1079 __func__, p->p_pid, td->td_name, it->it_need, td->td_state); 1080 } 1081 thread_unlock(td); 1082 1083 return (0); 1084} 1085#endif 1086 1087/* 1088 * Allow interrupt event binding for software interrupt handlers -- a no-op, 1089 * since interrupts are generated in software rather than being directed by 1090 * a PIC. 1091 */ 1092static int 1093swi_assign_cpu(void *arg, u_char cpu) 1094{ 1095 1096 return (0); 1097} 1098 1099/* 1100 * Add a software interrupt handler to a specified event. If a given event 1101 * is not specified, then a new event is created. 1102 */ 1103int 1104swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler, 1105 void *arg, int pri, enum intr_type flags, void **cookiep) 1106{ 1107 struct intr_event *ie; 1108 int error; 1109 1110 if (flags & INTR_ENTROPY) 1111 return (EINVAL); 1112 1113 ie = (eventp != NULL) ? *eventp : NULL; 1114 1115 if (ie != NULL) { 1116 if (!(ie->ie_flags & IE_SOFT)) 1117 return (EINVAL); 1118 } else { 1119 error = intr_event_create(&ie, NULL, IE_SOFT, 0, 1120 NULL, NULL, NULL, swi_assign_cpu, "swi%d:", pri); 1121 if (error) 1122 return (error); 1123 if (eventp != NULL) 1124 *eventp = ie; 1125 } 1126 error = intr_event_add_handler(ie, name, NULL, handler, arg, 1127 PI_SWI(pri), flags, cookiep); 1128 return (error); 1129} 1130 1131/* 1132 * Schedule a software interrupt thread. 1133 */ 1134void 1135swi_sched(void *cookie, int flags) 1136{ 1137 struct intr_handler *ih = (struct intr_handler *)cookie; 1138 struct intr_event *ie = ih->ih_event; 1139 struct intr_entropy entropy; 1140 int error; 1141 1142 CTR3(KTR_INTR, "swi_sched: %s %s need=%d", ie->ie_name, ih->ih_name, 1143 ih->ih_need); 1144 1145 if (harvest.swi) { 1146 CTR2(KTR_INTR, "swi_sched: pid %d (%s) gathering entropy", 1147 curproc->p_pid, curthread->td_name); 1148 entropy.event = (uintptr_t)ih; 1149 entropy.td = curthread; 1150 random_harvest(&entropy, sizeof(entropy), 1, 1151 RANDOM_SWI); 1152 } 1153 1154 /* 1155 * Set ih_need for this handler so that if the ithread is already 1156 * running it will execute this handler on the next pass. Otherwise, 1157 * it will execute it the next time it runs. 1158 */ 1159 atomic_store_rel_int(&ih->ih_need, 1); 1160 1161 if (!(flags & SWI_DELAY)) { 1162 PCPU_INC(cnt.v_soft); 1163#ifdef INTR_FILTER 1164 error = intr_event_schedule_thread(ie, ie->ie_thread); 1165#else 1166 error = intr_event_schedule_thread(ie); 1167#endif 1168 KASSERT(error == 0, ("stray software interrupt")); 1169 } 1170} 1171 1172/* 1173 * Remove a software interrupt handler. Currently this code does not 1174 * remove the associated interrupt event if it becomes empty. Calling code 1175 * may do so manually via intr_event_destroy(), but that's not really 1176 * an optimal interface. 1177 */ 1178int 1179swi_remove(void *cookie) 1180{ 1181 1182 return (intr_event_remove_handler(cookie)); 1183} 1184 1185#ifdef INTR_FILTER 1186static void 1187priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih) 1188{ 1189 struct intr_event *ie; 1190 1191 ie = ih->ih_event; 1192 /* 1193 * If this handler is marked for death, remove it from 1194 * the list of handlers and wake up the sleeper. 1195 */ 1196 if (ih->ih_flags & IH_DEAD) { 1197 mtx_lock(&ie->ie_lock); 1198 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next); 1199 ih->ih_flags &= ~IH_DEAD; 1200 wakeup(ih); 1201 mtx_unlock(&ie->ie_lock); 1202 return; 1203 } 1204 1205 /* Execute this handler. */ 1206 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1207 __func__, p->p_pid, (void *)ih->ih_handler, ih->ih_argument, 1208 ih->ih_name, ih->ih_flags); 1209 1210 if (!(ih->ih_flags & IH_MPSAFE)) 1211 mtx_lock(&Giant); 1212 ih->ih_handler(ih->ih_argument); 1213 if (!(ih->ih_flags & IH_MPSAFE)) 1214 mtx_unlock(&Giant); 1215} 1216#endif 1217 1218/* 1219 * This is a public function for use by drivers that mux interrupt 1220 * handlers for child devices from their interrupt handler. 1221 */ 1222void 1223intr_event_execute_handlers(struct proc *p, struct intr_event *ie) 1224{ 1225 struct intr_handler *ih, *ihn; 1226 1227 TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) { 1228 /* 1229 * If this handler is marked for death, remove it from 1230 * the list of handlers and wake up the sleeper. 1231 */ 1232 if (ih->ih_flags & IH_DEAD) { 1233 mtx_lock(&ie->ie_lock); 1234 TAILQ_REMOVE(&ie->ie_handlers, ih, ih_next); 1235 ih->ih_flags &= ~IH_DEAD; 1236 wakeup(ih); 1237 mtx_unlock(&ie->ie_lock); 1238 continue; 1239 } 1240 1241 /* Skip filter only handlers */ 1242 if (ih->ih_handler == NULL) 1243 continue; 1244 1245 /* 1246 * For software interrupt threads, we only execute 1247 * handlers that have their need flag set. Hardware 1248 * interrupt threads always invoke all of their handlers. 1249 */ 1250 if (ie->ie_flags & IE_SOFT) { 1251 if (atomic_load_acq_int(&ih->ih_need) == 0) 1252 continue; 1253 else 1254 atomic_store_rel_int(&ih->ih_need, 0); 1255 } 1256 1257 /* Execute this handler. */ 1258 CTR6(KTR_INTR, "%s: pid %d exec %p(%p) for %s flg=%x", 1259 __func__, p->p_pid, (void *)ih->ih_handler, 1260 ih->ih_argument, ih->ih_name, ih->ih_flags); 1261 1262 if (!(ih->ih_flags & IH_MPSAFE)) 1263 mtx_lock(&Giant); 1264 ih->ih_handler(ih->ih_argument); 1265 if (!(ih->ih_flags & IH_MPSAFE)) 1266 mtx_unlock(&Giant); 1267 } 1268} 1269 1270static void 1271ithread_execute_handlers(struct proc *p, struct intr_event *ie) 1272{ 1273 1274 /* Interrupt handlers should not sleep. */ 1275 if (!(ie->ie_flags & IE_SOFT)) 1276 THREAD_NO_SLEEPING(); 1277 intr_event_execute_handlers(p, ie); 1278 if (!(ie->ie_flags & IE_SOFT)) 1279 THREAD_SLEEPING_OK(); 1280 1281 /* 1282 * Interrupt storm handling: 1283 * 1284 * If this interrupt source is currently storming, then throttle 1285 * it to only fire the handler once per clock tick. 1286 * 1287 * If this interrupt source is not currently storming, but the 1288 * number of back to back interrupts exceeds the storm threshold, 1289 * then enter storming mode. 1290 */ 1291 if (intr_storm_threshold != 0 && ie->ie_count >= intr_storm_threshold && 1292 !(ie->ie_flags & IE_SOFT)) { 1293 /* Report the message only once every second. */ 1294 if (ppsratecheck(&ie->ie_warntm, &ie->ie_warncnt, 1)) { 1295 printf( 1296 "interrupt storm detected on \"%s\"; throttling interrupt source\n", 1297 ie->ie_name); 1298 } 1299 pause("istorm", 1); 1300 } else 1301 ie->ie_count++; 1302 1303 /* 1304 * Now that all the handlers have had a chance to run, reenable 1305 * the interrupt source. 1306 */ 1307 if (ie->ie_post_ithread != NULL) 1308 ie->ie_post_ithread(ie->ie_source); 1309} 1310 1311#ifndef INTR_FILTER 1312/* 1313 * This is the main code for interrupt threads. 1314 */ 1315static void 1316ithread_loop(void *arg) 1317{ 1318 struct intr_thread *ithd; 1319 struct intr_event *ie; 1320 struct thread *td; 1321 struct proc *p; 1322 int wake; 1323 1324 td = curthread; 1325 p = td->td_proc; 1326 ithd = (struct intr_thread *)arg; 1327 KASSERT(ithd->it_thread == td, 1328 ("%s: ithread and proc linkage out of sync", __func__)); 1329 ie = ithd->it_event; 1330 ie->ie_count = 0; 1331 wake = 0; 1332 1333 /* 1334 * As long as we have interrupts outstanding, go through the 1335 * list of handlers, giving each one a go at it. 1336 */ 1337 for (;;) { 1338 /* 1339 * If we are an orphaned thread, then just die. 1340 */ 1341 if (ithd->it_flags & IT_DEAD) { 1342 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1343 p->p_pid, td->td_name); 1344 free(ithd, M_ITHREAD); 1345 kthread_exit(); 1346 } 1347 1348 /* 1349 * Service interrupts. If another interrupt arrives while 1350 * we are running, it will set it_need to note that we 1351 * should make another pass. 1352 */ 1353 while (atomic_load_acq_int(&ithd->it_need) != 0) { 1354 /* 1355 * This might need a full read and write barrier 1356 * to make sure that this write posts before any 1357 * of the memory or device accesses in the 1358 * handlers. 1359 */ 1360 atomic_store_rel_int(&ithd->it_need, 0); 1361 ithread_execute_handlers(p, ie); 1362 } 1363 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1364 mtx_assert(&Giant, MA_NOTOWNED); 1365 1366 /* 1367 * Processed all our interrupts. Now get the sched 1368 * lock. This may take a while and it_need may get 1369 * set again, so we have to check it again. 1370 */ 1371 thread_lock(td); 1372 if ((atomic_load_acq_int(&ithd->it_need) == 0) && 1373 !(ithd->it_flags & (IT_DEAD | IT_WAIT))) { 1374 TD_SET_IWAIT(td); 1375 ie->ie_count = 0; 1376 mi_switch(SW_VOL | SWT_IWAIT, NULL); 1377 } 1378 if (ithd->it_flags & IT_WAIT) { 1379 wake = 1; 1380 ithd->it_flags &= ~IT_WAIT; 1381 } 1382 thread_unlock(td); 1383 if (wake) { 1384 wakeup(ithd); 1385 wake = 0; 1386 } 1387 } 1388} 1389 1390/* 1391 * Main interrupt handling body. 1392 * 1393 * Input: 1394 * o ie: the event connected to this interrupt. 1395 * o frame: some archs (i.e. i386) pass a frame to some. 1396 * handlers as their main argument. 1397 * Return value: 1398 * o 0: everything ok. 1399 * o EINVAL: stray interrupt. 1400 */ 1401int 1402intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1403{ 1404 struct intr_handler *ih; 1405 struct trapframe *oldframe; 1406 struct thread *td; 1407 int error, ret, thread; 1408 1409 td = curthread; 1410 1411#ifdef KSTACK_USAGE_PROF 1412 intr_prof_stack_use(td, frame); 1413#endif 1414 1415 /* An interrupt with no event or handlers is a stray interrupt. */ 1416 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers)) 1417 return (EINVAL); 1418 1419 /* 1420 * Execute fast interrupt handlers directly. 1421 * To support clock handlers, if a handler registers 1422 * with a NULL argument, then we pass it a pointer to 1423 * a trapframe as its argument. 1424 */ 1425 td->td_intr_nesting_level++; 1426 thread = 0; 1427 ret = 0; 1428 critical_enter(); 1429 oldframe = td->td_intr_frame; 1430 td->td_intr_frame = frame; 1431 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1432 if (ih->ih_filter == NULL) { 1433 thread = 1; 1434 continue; 1435 } 1436 CTR4(KTR_INTR, "%s: exec %p(%p) for %s", __func__, 1437 ih->ih_filter, ih->ih_argument == NULL ? frame : 1438 ih->ih_argument, ih->ih_name); 1439 if (ih->ih_argument == NULL) 1440 ret = ih->ih_filter(frame); 1441 else 1442 ret = ih->ih_filter(ih->ih_argument); 1443 KASSERT(ret == FILTER_STRAY || 1444 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1445 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1446 ("%s: incorrect return value %#x from %s", __func__, ret, 1447 ih->ih_name)); 1448 1449 /* 1450 * Wrapper handler special handling: 1451 * 1452 * in some particular cases (like pccard and pccbb), 1453 * the _real_ device handler is wrapped in a couple of 1454 * functions - a filter wrapper and an ithread wrapper. 1455 * In this case (and just in this case), the filter wrapper 1456 * could ask the system to schedule the ithread and mask 1457 * the interrupt source if the wrapped handler is composed 1458 * of just an ithread handler. 1459 * 1460 * TODO: write a generic wrapper to avoid people rolling 1461 * their own 1462 */ 1463 if (!thread) { 1464 if (ret == FILTER_SCHEDULE_THREAD) 1465 thread = 1; 1466 } 1467 } 1468 td->td_intr_frame = oldframe; 1469 1470 if (thread) { 1471 if (ie->ie_pre_ithread != NULL) 1472 ie->ie_pre_ithread(ie->ie_source); 1473 } else { 1474 if (ie->ie_post_filter != NULL) 1475 ie->ie_post_filter(ie->ie_source); 1476 } 1477 1478 /* Schedule the ithread if needed. */ 1479 if (thread) { 1480 error = intr_event_schedule_thread(ie); 1481#ifndef XEN 1482 KASSERT(error == 0, ("bad stray interrupt")); 1483#else 1484 if (error != 0) 1485 log(LOG_WARNING, "bad stray interrupt"); 1486#endif 1487 } 1488 critical_exit(); 1489 td->td_intr_nesting_level--; 1490 return (0); 1491} 1492#else 1493/* 1494 * This is the main code for interrupt threads. 1495 */ 1496static void 1497ithread_loop(void *arg) 1498{ 1499 struct intr_thread *ithd; 1500 struct intr_handler *ih; 1501 struct intr_event *ie; 1502 struct thread *td; 1503 struct proc *p; 1504 int priv; 1505 int wake; 1506 1507 td = curthread; 1508 p = td->td_proc; 1509 ih = (struct intr_handler *)arg; 1510 priv = (ih->ih_thread != NULL) ? 1 : 0; 1511 ithd = (priv) ? ih->ih_thread : ih->ih_event->ie_thread; 1512 KASSERT(ithd->it_thread == td, 1513 ("%s: ithread and proc linkage out of sync", __func__)); 1514 ie = ithd->it_event; 1515 ie->ie_count = 0; 1516 wake = 0; 1517 1518 /* 1519 * As long as we have interrupts outstanding, go through the 1520 * list of handlers, giving each one a go at it. 1521 */ 1522 for (;;) { 1523 /* 1524 * If we are an orphaned thread, then just die. 1525 */ 1526 if (ithd->it_flags & IT_DEAD) { 1527 CTR3(KTR_INTR, "%s: pid %d (%s) exiting", __func__, 1528 p->p_pid, td->td_name); 1529 free(ithd, M_ITHREAD); 1530 kthread_exit(); 1531 } 1532 1533 /* 1534 * Service interrupts. If another interrupt arrives while 1535 * we are running, it will set it_need to note that we 1536 * should make another pass. 1537 */ 1538 while (atomic_load_acq_int(&ithd->it_need) != 0) { 1539 /* 1540 * This might need a full read and write barrier 1541 * to make sure that this write posts before any 1542 * of the memory or device accesses in the 1543 * handlers. 1544 */ 1545 atomic_store_rel_int(&ithd->it_need, 0); 1546 if (priv) 1547 priv_ithread_execute_handler(p, ih); 1548 else 1549 ithread_execute_handlers(p, ie); 1550 } 1551 WITNESS_WARN(WARN_PANIC, NULL, "suspending ithread"); 1552 mtx_assert(&Giant, MA_NOTOWNED); 1553 1554 /* 1555 * Processed all our interrupts. Now get the sched 1556 * lock. This may take a while and it_need may get 1557 * set again, so we have to check it again. 1558 */ 1559 thread_lock(td); 1560 if ((atomic_load_acq_int(&ithd->it_need) == 0) && 1561 !(ithd->it_flags & (IT_DEAD | IT_WAIT))) { 1562 TD_SET_IWAIT(td); 1563 ie->ie_count = 0; 1564 mi_switch(SW_VOL | SWT_IWAIT, NULL); 1565 } 1566 if (ithd->it_flags & IT_WAIT) { 1567 wake = 1; 1568 ithd->it_flags &= ~IT_WAIT; 1569 } 1570 thread_unlock(td); 1571 if (wake) { 1572 wakeup(ithd); 1573 wake = 0; 1574 } 1575 } 1576} 1577 1578/* 1579 * Main loop for interrupt filter. 1580 * 1581 * Some architectures (i386, amd64 and arm) require the optional frame 1582 * parameter, and use it as the main argument for fast handler execution 1583 * when ih_argument == NULL. 1584 * 1585 * Return value: 1586 * o FILTER_STRAY: No filter recognized the event, and no 1587 * filter-less handler is registered on this 1588 * line. 1589 * o FILTER_HANDLED: A filter claimed the event and served it. 1590 * o FILTER_SCHEDULE_THREAD: No filter claimed the event, but there's at 1591 * least one filter-less handler on this line. 1592 * o FILTER_HANDLED | 1593 * FILTER_SCHEDULE_THREAD: A filter claimed the event, and asked for 1594 * scheduling the per-handler ithread. 1595 * 1596 * In case an ithread has to be scheduled, in *ithd there will be a 1597 * pointer to a struct intr_thread containing the thread to be 1598 * scheduled. 1599 */ 1600 1601static int 1602intr_filter_loop(struct intr_event *ie, struct trapframe *frame, 1603 struct intr_thread **ithd) 1604{ 1605 struct intr_handler *ih; 1606 void *arg; 1607 int ret, thread_only; 1608 1609 ret = 0; 1610 thread_only = 0; 1611 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) { 1612 /* 1613 * Execute fast interrupt handlers directly. 1614 * To support clock handlers, if a handler registers 1615 * with a NULL argument, then we pass it a pointer to 1616 * a trapframe as its argument. 1617 */ 1618 arg = ((ih->ih_argument == NULL) ? frame : ih->ih_argument); 1619 1620 CTR5(KTR_INTR, "%s: exec %p/%p(%p) for %s", __func__, 1621 ih->ih_filter, ih->ih_handler, arg, ih->ih_name); 1622 1623 if (ih->ih_filter != NULL) 1624 ret = ih->ih_filter(arg); 1625 else { 1626 thread_only = 1; 1627 continue; 1628 } 1629 KASSERT(ret == FILTER_STRAY || 1630 ((ret & (FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) != 0 && 1631 (ret & ~(FILTER_SCHEDULE_THREAD | FILTER_HANDLED)) == 0), 1632 ("%s: incorrect return value %#x from %s", __func__, ret, 1633 ih->ih_name)); 1634 if (ret & FILTER_STRAY) 1635 continue; 1636 else { 1637 *ithd = ih->ih_thread; 1638 return (ret); 1639 } 1640 } 1641 1642 /* 1643 * No filters handled the interrupt and we have at least 1644 * one handler without a filter. In this case, we schedule 1645 * all of the filter-less handlers to run in the ithread. 1646 */ 1647 if (thread_only) { 1648 *ithd = ie->ie_thread; 1649 return (FILTER_SCHEDULE_THREAD); 1650 } 1651 return (FILTER_STRAY); 1652} 1653 1654/* 1655 * Main interrupt handling body. 1656 * 1657 * Input: 1658 * o ie: the event connected to this interrupt. 1659 * o frame: some archs (i.e. i386) pass a frame to some. 1660 * handlers as their main argument. 1661 * Return value: 1662 * o 0: everything ok. 1663 * o EINVAL: stray interrupt. 1664 */ 1665int 1666intr_event_handle(struct intr_event *ie, struct trapframe *frame) 1667{ 1668 struct intr_thread *ithd; 1669 struct trapframe *oldframe; 1670 struct thread *td; 1671 int thread; 1672 1673 ithd = NULL; 1674 td = curthread; 1675 1676 if (ie == NULL || TAILQ_EMPTY(&ie->ie_handlers)) 1677 return (EINVAL); 1678 1679 td->td_intr_nesting_level++; 1680 thread = 0; 1681 critical_enter(); 1682 oldframe = td->td_intr_frame; 1683 td->td_intr_frame = frame; 1684 thread = intr_filter_loop(ie, frame, &ithd); 1685 if (thread & FILTER_HANDLED) { 1686 if (ie->ie_post_filter != NULL) 1687 ie->ie_post_filter(ie->ie_source); 1688 } else { 1689 if (ie->ie_pre_ithread != NULL) 1690 ie->ie_pre_ithread(ie->ie_source); 1691 } 1692 td->td_intr_frame = oldframe; 1693 critical_exit(); 1694 1695 /* Interrupt storm logic */ 1696 if (thread & FILTER_STRAY) { 1697 ie->ie_count++; 1698 if (ie->ie_count < intr_storm_threshold) 1699 printf("Interrupt stray detection not present\n"); 1700 } 1701 1702 /* Schedule an ithread if needed. */ 1703 if (thread & FILTER_SCHEDULE_THREAD) { 1704 if (intr_event_schedule_thread(ie, ithd) != 0) 1705 panic("%s: impossible stray interrupt", __func__); 1706 } 1707 td->td_intr_nesting_level--; 1708 return (0); 1709} 1710#endif 1711 1712#ifdef DDB 1713/* 1714 * Dump details about an interrupt handler 1715 */ 1716static void 1717db_dump_intrhand(struct intr_handler *ih) 1718{ 1719 int comma; 1720 1721 db_printf("\t%-10s ", ih->ih_name); 1722 switch (ih->ih_pri) { 1723 case PI_REALTIME: 1724 db_printf("CLK "); 1725 break; 1726 case PI_AV: 1727 db_printf("AV "); 1728 break; 1729 case PI_TTY: 1730 db_printf("TTY "); 1731 break; 1732 case PI_NET: 1733 db_printf("NET "); 1734 break; 1735 case PI_DISK: 1736 db_printf("DISK"); 1737 break; 1738 case PI_DULL: 1739 db_printf("DULL"); 1740 break; 1741 default: 1742 if (ih->ih_pri >= PI_SOFT) 1743 db_printf("SWI "); 1744 else 1745 db_printf("%4u", ih->ih_pri); 1746 break; 1747 } 1748 db_printf(" "); 1749 if (ih->ih_filter != NULL) { 1750 db_printf("[F]"); 1751 db_printsym((uintptr_t)ih->ih_filter, DB_STGY_PROC); 1752 } 1753 if (ih->ih_handler != NULL) { 1754 if (ih->ih_filter != NULL) 1755 db_printf(","); 1756 db_printf("[H]"); 1757 db_printsym((uintptr_t)ih->ih_handler, DB_STGY_PROC); 1758 } 1759 db_printf("(%p)", ih->ih_argument); 1760 if (ih->ih_need || 1761 (ih->ih_flags & (IH_EXCLUSIVE | IH_ENTROPY | IH_DEAD | 1762 IH_MPSAFE)) != 0) { 1763 db_printf(" {"); 1764 comma = 0; 1765 if (ih->ih_flags & IH_EXCLUSIVE) { 1766 if (comma) 1767 db_printf(", "); 1768 db_printf("EXCL"); 1769 comma = 1; 1770 } 1771 if (ih->ih_flags & IH_ENTROPY) { 1772 if (comma) 1773 db_printf(", "); 1774 db_printf("ENTROPY"); 1775 comma = 1; 1776 } 1777 if (ih->ih_flags & IH_DEAD) { 1778 if (comma) 1779 db_printf(", "); 1780 db_printf("DEAD"); 1781 comma = 1; 1782 } 1783 if (ih->ih_flags & IH_MPSAFE) { 1784 if (comma) 1785 db_printf(", "); 1786 db_printf("MPSAFE"); 1787 comma = 1; 1788 } 1789 if (ih->ih_need) { 1790 if (comma) 1791 db_printf(", "); 1792 db_printf("NEED"); 1793 } 1794 db_printf("}"); 1795 } 1796 db_printf("\n"); 1797} 1798 1799/* 1800 * Dump details about a event. 1801 */ 1802void 1803db_dump_intr_event(struct intr_event *ie, int handlers) 1804{ 1805 struct intr_handler *ih; 1806 struct intr_thread *it; 1807 int comma; 1808 1809 db_printf("%s ", ie->ie_fullname); 1810 it = ie->ie_thread; 1811 if (it != NULL) 1812 db_printf("(pid %d)", it->it_thread->td_proc->p_pid); 1813 else 1814 db_printf("(no thread)"); 1815 if ((ie->ie_flags & (IE_SOFT | IE_ENTROPY | IE_ADDING_THREAD)) != 0 || 1816 (it != NULL && it->it_need)) { 1817 db_printf(" {"); 1818 comma = 0; 1819 if (ie->ie_flags & IE_SOFT) { 1820 db_printf("SOFT"); 1821 comma = 1; 1822 } 1823 if (ie->ie_flags & IE_ENTROPY) { 1824 if (comma) 1825 db_printf(", "); 1826 db_printf("ENTROPY"); 1827 comma = 1; 1828 } 1829 if (ie->ie_flags & IE_ADDING_THREAD) { 1830 if (comma) 1831 db_printf(", "); 1832 db_printf("ADDING_THREAD"); 1833 comma = 1; 1834 } 1835 if (it != NULL && it->it_need) { 1836 if (comma) 1837 db_printf(", "); 1838 db_printf("NEED"); 1839 } 1840 db_printf("}"); 1841 } 1842 db_printf("\n"); 1843 1844 if (handlers) 1845 TAILQ_FOREACH(ih, &ie->ie_handlers, ih_next) 1846 db_dump_intrhand(ih); 1847} 1848 1849/* 1850 * Dump data about interrupt handlers 1851 */ 1852DB_SHOW_COMMAND(intr, db_show_intr) 1853{ 1854 struct intr_event *ie; 1855 int all, verbose; 1856 1857 verbose = strchr(modif, 'v') != NULL; 1858 all = strchr(modif, 'a') != NULL; 1859 TAILQ_FOREACH(ie, &event_list, ie_list) { 1860 if (!all && TAILQ_EMPTY(&ie->ie_handlers)) 1861 continue; 1862 db_dump_intr_event(ie, verbose); 1863 if (db_pager_quit) 1864 break; 1865 } 1866} 1867#endif /* DDB */ 1868 1869/* 1870 * Start standard software interrupt threads 1871 */ 1872static void 1873start_softintr(void *dummy) 1874{ 1875 1876 if (swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, INTR_MPSAFE, &vm_ih)) 1877 panic("died while creating vm swi ithread"); 1878} 1879SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, 1880 NULL); 1881 1882/* 1883 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. 1884 * The data for this machine dependent, and the declarations are in machine 1885 * dependent code. The layout of intrnames and intrcnt however is machine 1886 * independent. 1887 * 1888 * We do not know the length of intrcnt and intrnames at compile time, so 1889 * calculate things at run time. 1890 */ 1891static int 1892sysctl_intrnames(SYSCTL_HANDLER_ARGS) 1893{ 1894 return (sysctl_handle_opaque(oidp, intrnames, sintrnames, req)); 1895} 1896 1897SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD, 1898 NULL, 0, sysctl_intrnames, "", "Interrupt Names"); 1899 1900static int 1901sysctl_intrcnt(SYSCTL_HANDLER_ARGS) 1902{ 1903#ifdef SCTL_MASK32 1904 uint32_t *intrcnt32; 1905 unsigned i; 1906 int error; 1907 1908 if (req->flags & SCTL_MASK32) { 1909 if (!req->oldptr) 1910 return (sysctl_handle_opaque(oidp, NULL, sintrcnt / 2, req)); 1911 intrcnt32 = malloc(sintrcnt / 2, M_TEMP, M_NOWAIT); 1912 if (intrcnt32 == NULL) 1913 return (ENOMEM); 1914 for (i = 0; i < sintrcnt / sizeof (u_long); i++) 1915 intrcnt32[i] = intrcnt[i]; 1916 error = sysctl_handle_opaque(oidp, intrcnt32, sintrcnt / 2, req); 1917 free(intrcnt32, M_TEMP); 1918 return (error); 1919 } 1920#endif 1921 return (sysctl_handle_opaque(oidp, intrcnt, sintrcnt, req)); 1922} 1923 1924SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD, 1925 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts"); 1926 1927#ifdef DDB 1928/* 1929 * DDB command to dump the interrupt statistics. 1930 */ 1931DB_SHOW_COMMAND(intrcnt, db_show_intrcnt) 1932{ 1933 u_long *i; 1934 char *cp; 1935 u_int j; 1936 1937 cp = intrnames; 1938 j = 0; 1939 for (i = intrcnt; j < (sintrcnt / sizeof(u_long)) && !db_pager_quit; 1940 i++, j++) { 1941 if (*cp == '\0') 1942 break; 1943 if (*i != 0) 1944 db_printf("%s\t%lu\n", cp, *i); 1945 cp += strlen(cp) + 1; 1946 } 1947} 1948#endif 1949