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 * $FreeBSD$ 27 * 28 */ 29 30 31 #include <sys/param.h> 32 #include <sys/bus.h> 33 #include <sys/conf.h> 34 #include <sys/rtprio.h> 35 #include <sys/systm.h> 36 #include <sys/interrupt.h> 37 #include <sys/kernel.h> 38 #include <sys/kthread.h> 39 #include <sys/ktr.h> 40 #include <sys/lock.h> 41 #include <sys/malloc.h> 42 #include <sys/mutex.h> 43 #include <sys/proc.h> 44 #include <sys/random.h> 45 #include <sys/resourcevar.h> 46 #include <sys/sysctl.h> 47 #include <sys/unistd.h> 48 #include <sys/vmmeter.h> 49 #include <machine/atomic.h> 50 #include <machine/cpu.h> 51 #include <machine/md_var.h> 52 #include <machine/stdarg.h> 53 54 struct int_entropy { 55 struct proc *proc; 56 int vector; 57 }; 58 59 void *vm_ih; 60 void *softclock_ih; 61 struct ithd *clk_ithd; 62 struct ithd *tty_ithd; 63 64 static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads"); 65 66 static void ithread_update(struct ithd *); 67 static void ithread_loop(void *); 68 static void start_softintr(void *); 69 70 u_char 71 ithread_priority(enum intr_type flags) 72 { 73 u_char pri; 74 75 flags &= (INTR_TYPE_TTY | INTR_TYPE_BIO | INTR_TYPE_NET | 76 INTR_TYPE_CAM | INTR_TYPE_MISC | INTR_TYPE_CLK | INTR_TYPE_AV); 77 switch (flags) { 78 case INTR_TYPE_TTY: 79 pri = PI_TTYLOW; 80 break; 81 case INTR_TYPE_BIO: 82 /* 83 * XXX We need to refine this. BSD/OS distinguishes 84 * between tape and disk priorities. 85 */ 86 pri = PI_DISK; 87 break; 88 case INTR_TYPE_NET: 89 pri = PI_NET; 90 break; 91 case INTR_TYPE_CAM: 92 pri = PI_DISK; /* XXX or PI_CAM? */ 93 break; 94 case INTR_TYPE_AV: /* Audio/video */ 95 pri = PI_AV; 96 break; 97 case INTR_TYPE_CLK: 98 pri = PI_REALTIME; 99 break; 100 case INTR_TYPE_MISC: 101 pri = PI_DULL; /* don't care */ 102 break; 103 default: 104 /* We didn't specify an interrupt level. */ 105 panic("ithread_priority: no interrupt type in flags"); 106 } 107 108 return pri; 109 } 110 111 /* 112 * Regenerate the name (p_comm) and priority for a threaded interrupt thread. 113 */ 114 static void 115 ithread_update(struct ithd *ithd) 116 { 117 struct intrhand *ih; 118 struct thread *td; 119 struct proc *p; 120 int entropy; 121 122 mtx_assert(&ithd->it_lock, MA_OWNED); 123 td = ithd->it_td; 124 if (td == NULL) 125 return; 126 p = td->td_proc; 127 128 strlcpy(p->p_comm, ithd->it_name, sizeof(p->p_comm)); 129 130 ih = TAILQ_FIRST(&ithd->it_handlers); 131 if (ih == NULL) { 132 mtx_lock_spin(&sched_lock); 133 td->td_priority = PRI_MAX_ITHD; 134 td->td_base_pri = PRI_MAX_ITHD; 135 mtx_unlock_spin(&sched_lock); 136 ithd->it_flags &= ~IT_ENTROPY; 137 return; 138 } 139 entropy = 0; 140 mtx_lock_spin(&sched_lock); 141 td->td_priority = ih->ih_pri; 142 td->td_base_pri = ih->ih_pri; 143 mtx_unlock_spin(&sched_lock); 144 TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next) { 145 if (strlen(p->p_comm) + strlen(ih->ih_name) + 1 < 146 sizeof(p->p_comm)) { 147 strcat(p->p_comm, " "); 148 strcat(p->p_comm, ih->ih_name); 149 } else if (strlen(p->p_comm) + 1 == sizeof(p->p_comm)) { 150 if (p->p_comm[sizeof(p->p_comm) - 2] == '+') 151 p->p_comm[sizeof(p->p_comm) - 2] = '*'; 152 else 153 p->p_comm[sizeof(p->p_comm) - 2] = '+'; 154 } else 155 strcat(p->p_comm, "+"); 156 if (ih->ih_flags & IH_ENTROPY) 157 entropy++; 158 } 159 if (entropy) 160 ithd->it_flags |= IT_ENTROPY; 161 else 162 ithd->it_flags &= ~IT_ENTROPY; 163 CTR2(KTR_INTR, "%s: updated %s", __func__, p->p_comm); 164 } 165 166 int 167 ithread_create(struct ithd **ithread, int vector, int flags, 168 void (*disable)(int), void (*enable)(int), const char *fmt, ...) 169 { 170 struct ithd *ithd; 171 struct thread *td; 172 struct proc *p; 173 int error; 174 va_list ap; 175 176 /* The only valid flag during creation is IT_SOFT. */ 177 if ((flags & ~IT_SOFT) != 0) 178 return (EINVAL); 179 180 ithd = malloc(sizeof(struct ithd), M_ITHREAD, M_WAITOK | M_ZERO); 181 ithd->it_vector = vector; 182 ithd->it_disable = disable; 183 ithd->it_enable = enable; 184 ithd->it_flags = flags; 185 TAILQ_INIT(&ithd->it_handlers); 186 mtx_init(&ithd->it_lock, "ithread", NULL, MTX_DEF); 187 188 va_start(ap, fmt); 189 vsnprintf(ithd->it_name, sizeof(ithd->it_name), fmt, ap); 190 va_end(ap); 191 192 error = kthread_create(ithread_loop, ithd, &p, RFSTOPPED | RFHIGHPID, 193 0, "%s", ithd->it_name); 194 if (error) { 195 mtx_destroy(&ithd->it_lock); 196 free(ithd, M_ITHREAD); 197 return (error); 198 } 199 td = FIRST_THREAD_IN_PROC(p); /* XXXKSE */ 200 td->td_ksegrp->kg_pri_class = PRI_ITHD; 201 td->td_priority = PRI_MAX_ITHD; 202 TD_SET_IWAIT(td); 203 ithd->it_td = td; 204 td->td_ithd = ithd; 205 if (ithread != NULL) 206 *ithread = ithd; 207 208 CTR2(KTR_INTR, "%s: created %s", __func__, ithd->it_name); 209 return (0); 210 } 211 212 int 213 ithread_destroy(struct ithd *ithread) 214 { 215 216 struct thread *td; 217 struct proc *p; 218 if (ithread == NULL) 219 return (EINVAL); 220 221 td = ithread->it_td; 222 p = td->td_proc; 223 mtx_lock(&ithread->it_lock); 224 if (!TAILQ_EMPTY(&ithread->it_handlers)) { 225 mtx_unlock(&ithread->it_lock); 226 return (EINVAL); 227 } 228 ithread->it_flags |= IT_DEAD; 229 mtx_lock_spin(&sched_lock); 230 if (TD_AWAITING_INTR(td)) { 231 TD_CLR_IWAIT(td); 232 setrunqueue(td); 233 } 234 mtx_unlock_spin(&sched_lock); 235 mtx_unlock(&ithread->it_lock); 236 CTR2(KTR_INTR, "%s: killing %s", __func__, ithread->it_name); 237 return (0); 238 } 239 240 int 241 ithread_add_handler(struct ithd* ithread, const char *name, 242 driver_intr_t handler, void *arg, u_char pri, enum intr_type flags, 243 void **cookiep) 244 { 245 struct intrhand *ih, *temp_ih; 246 247 if (ithread == NULL || name == NULL || handler == NULL) 248 return (EINVAL); 249 if ((flags & INTR_FAST) !=0) 250 flags |= INTR_EXCL; 251 252 ih = malloc(sizeof(struct intrhand), M_ITHREAD, M_WAITOK | M_ZERO); 253 ih->ih_handler = handler; 254 ih->ih_argument = arg; 255 ih->ih_name = name; 256 ih->ih_ithread = ithread; 257 ih->ih_pri = pri; 258 if (flags & INTR_FAST) 259 ih->ih_flags = IH_FAST | IH_EXCLUSIVE; 260 else if (flags & INTR_EXCL) 261 ih->ih_flags = IH_EXCLUSIVE; 262 if (flags & INTR_MPSAFE) 263 ih->ih_flags |= IH_MPSAFE; 264 if (flags & INTR_ENTROPY) 265 ih->ih_flags |= IH_ENTROPY; 266 267 mtx_lock(&ithread->it_lock); 268 if ((flags & INTR_EXCL) !=0 && !TAILQ_EMPTY(&ithread->it_handlers)) 269 goto fail; 270 if (!TAILQ_EMPTY(&ithread->it_handlers) && 271 (TAILQ_FIRST(&ithread->it_handlers)->ih_flags & IH_EXCLUSIVE) != 0) 272 goto fail; 273 274 TAILQ_FOREACH(temp_ih, &ithread->it_handlers, ih_next) 275 if (temp_ih->ih_pri > ih->ih_pri) 276 break; 277 if (temp_ih == NULL) 278 TAILQ_INSERT_TAIL(&ithread->it_handlers, ih, ih_next); 279 else 280 TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); 281 ithread_update(ithread); 282 mtx_unlock(&ithread->it_lock); 283 284 if (cookiep != NULL) 285 *cookiep = ih; 286 CTR3(KTR_INTR, "%s: added %s to %s", __func__, ih->ih_name, 287 ithread->it_name); 288 return (0); 289 290 fail: 291 mtx_unlock(&ithread->it_lock); 292 free(ih, M_ITHREAD); 293 return (EINVAL); 294 } 295 296 int 297 ithread_remove_handler(void *cookie) 298 { 299 struct intrhand *handler = (struct intrhand *)cookie; 300 struct ithd *ithread; 301 #ifdef INVARIANTS 302 struct intrhand *ih; 303 #endif 304 305 if (handler == NULL) 306 return (EINVAL); 307 ithread = handler->ih_ithread; 308 KASSERT(ithread != NULL, 309 ("interrupt handler \"%s\" has a NULL interrupt thread", 310 handler->ih_name)); 311 CTR3(KTR_INTR, "%s: removing %s from %s", __func__, handler->ih_name, 312 ithread->it_name); 313 mtx_lock(&ithread->it_lock); 314 #ifdef INVARIANTS 315 TAILQ_FOREACH(ih, &ithread->it_handlers, ih_next) 316 if (ih == handler) 317 goto ok; 318 mtx_unlock(&ithread->it_lock); 319 panic("interrupt handler \"%s\" not found in interrupt thread \"%s\"", 320 ih->ih_name, ithread->it_name); 321 ok: 322 #endif 323 /* 324 * If the interrupt thread is already running, then just mark this 325 * handler as being dead and let the ithread do the actual removal. 326 */ 327 mtx_lock_spin(&sched_lock); 328 if (!TD_AWAITING_INTR(ithread->it_td)) { 329 handler->ih_flags |= IH_DEAD; 330 331 /* 332 * Ensure that the thread will process the handler list 333 * again and remove this handler if it has already passed 334 * it on the list. 335 */ 336 ithread->it_need = 1; 337 } else 338 TAILQ_REMOVE(&ithread->it_handlers, handler, ih_next); 339 mtx_unlock_spin(&sched_lock); 340 if ((handler->ih_flags & IH_DEAD) != 0) 341 msleep(handler, &ithread->it_lock, PUSER, "itrmh", 0); 342 ithread_update(ithread); 343 mtx_unlock(&ithread->it_lock); 344 free(handler, M_ITHREAD); 345 return (0); 346 } 347 348 int 349 ithread_schedule(struct ithd *ithread, int do_switch) 350 { 351 struct int_entropy entropy; 352 struct thread *td; 353 struct thread *ctd; 354 struct proc *p; 355 356 /* 357 * If no ithread or no handlers, then we have a stray interrupt. 358 */ 359 if ((ithread == NULL) || TAILQ_EMPTY(&ithread->it_handlers)) 360 return (EINVAL); 361 362 ctd = curthread; 363 /* 364 * If any of the handlers for this ithread claim to be good 365 * sources of entropy, then gather some. 366 */ 367 if (harvest.interrupt && ithread->it_flags & IT_ENTROPY) { 368 entropy.vector = ithread->it_vector; 369 entropy.proc = ctd->td_proc; 370 random_harvest(&entropy, sizeof(entropy), 2, 0, 371 RANDOM_INTERRUPT); 372 } 373 374 td = ithread->it_td; 375 p = td->td_proc; 376 KASSERT(p != NULL, ("ithread %s has no process", ithread->it_name)); 377 CTR4(KTR_INTR, "%s: pid %d: (%s) need = %d", 378 __func__, p->p_pid, p->p_comm, ithread->it_need); 379 380 /* 381 * Set it_need to tell the thread to keep running if it is already 382 * running. Then, grab sched_lock and see if we actually need to 383 * put this thread on the runqueue. If so and the do_switch flag is 384 * true and it is safe to switch, then switch to the ithread 385 * immediately. Otherwise, set the needresched flag to guarantee 386 * that this ithread will run before any userland processes. 387 */ 388 ithread->it_need = 1; 389 mtx_lock_spin(&sched_lock); 390 if (TD_AWAITING_INTR(td)) { 391 CTR2(KTR_INTR, "%s: setrunqueue %d", __func__, p->p_pid); 392 TD_CLR_IWAIT(td); 393 setrunqueue(td); 394 if (do_switch && 395 (ctd->td_critnest == 1) ) { 396 KASSERT((TD_IS_RUNNING(ctd)), 397 ("ithread_schedule: Bad state for curthread.")); 398 ctd->td_proc->p_stats->p_ru.ru_nivcsw++; 399 if (ctd->td_kse->ke_flags & KEF_IDLEKSE) 400 ctd->td_state = TDS_CAN_RUN; /* XXXKSE */ 401 mi_switch(); 402 } else { 403 curthread->td_flags |= TDF_NEEDRESCHED; 404 } 405 } else { 406 CTR4(KTR_INTR, "%s: pid %d: it_need %d, state %d", 407 __func__, p->p_pid, ithread->it_need, p->p_state); 408 } 409 mtx_unlock_spin(&sched_lock); 410 411 return (0); 412 } 413 414 int 415 swi_add(struct ithd **ithdp, const char *name, driver_intr_t handler, 416 void *arg, int pri, enum intr_type flags, void **cookiep) 417 { 418 struct ithd *ithd; 419 int error; 420 421 if (flags & (INTR_FAST | INTR_ENTROPY)) 422 return (EINVAL); 423 424 ithd = (ithdp != NULL) ? *ithdp : NULL; 425 426 if (ithd != NULL) { 427 if ((ithd->it_flags & IT_SOFT) == 0) 428 return(EINVAL); 429 } else { 430 error = ithread_create(&ithd, pri, IT_SOFT, NULL, NULL, 431 "swi%d:", pri); 432 if (error) 433 return (error); 434 435 if (ithdp != NULL) 436 *ithdp = ithd; 437 } 438 return (ithread_add_handler(ithd, name, handler, arg, 439 (pri * RQ_PPQ) + PI_SOFT, flags, cookiep)); 440 } 441 442 443 /* 444 * Schedule a heavyweight software interrupt process. 445 */ 446 void 447 swi_sched(void *cookie, int flags) 448 { 449 struct intrhand *ih = (struct intrhand *)cookie; 450 struct ithd *it = ih->ih_ithread; 451 int error; 452 453 atomic_add_int(&cnt.v_intr, 1); /* one more global interrupt */ 454 455 CTR3(KTR_INTR, "swi_sched pid %d(%s) need=%d", 456 it->it_td->td_proc->p_pid, it->it_td->td_proc->p_comm, it->it_need); 457 458 /* 459 * Set ih_need for this handler so that if the ithread is already 460 * running it will execute this handler on the next pass. Otherwise, 461 * it will execute it the next time it runs. 462 */ 463 atomic_store_rel_int(&ih->ih_need, 1); 464 if (!(flags & SWI_DELAY)) { 465 error = ithread_schedule(it, !cold && !dumping); 466 KASSERT(error == 0, ("stray software interrupt")); 467 } 468 } 469 470 /* 471 * This is the main code for interrupt threads. 472 */ 473 static void 474 ithread_loop(void *arg) 475 { 476 struct ithd *ithd; /* our thread context */ 477 struct intrhand *ih; /* and our interrupt handler chain */ 478 struct thread *td; 479 struct proc *p; 480 481 td = curthread; 482 p = td->td_proc; 483 ithd = (struct ithd *)arg; /* point to myself */ 484 KASSERT(ithd->it_td == td && td->td_ithd == ithd, 485 ("%s: ithread and proc linkage out of sync", __func__)); 486 487 /* 488 * As long as we have interrupts outstanding, go through the 489 * list of handlers, giving each one a go at it. 490 */ 491 for (;;) { 492 /* 493 * If we are an orphaned thread, then just die. 494 */ 495 if (ithd->it_flags & IT_DEAD) { 496 CTR3(KTR_INTR, "%s: pid %d: (%s) exiting", __func__, 497 p->p_pid, p->p_comm); 498 td->td_ithd = NULL; 499 mtx_destroy(&ithd->it_lock); 500 mtx_lock(&Giant); 501 free(ithd, M_ITHREAD); 502 kthread_exit(0); 503 } 504 505 CTR4(KTR_INTR, "%s: pid %d: (%s) need=%d", __func__, 506 p->p_pid, p->p_comm, ithd->it_need); 507 while (ithd->it_need) { 508 /* 509 * Service interrupts. If another interrupt 510 * arrives while we are running, they will set 511 * it_need to denote that we should make 512 * another pass. 513 */ 514 atomic_store_rel_int(&ithd->it_need, 0); 515 restart: 516 TAILQ_FOREACH(ih, &ithd->it_handlers, ih_next) { 517 if (ithd->it_flags & IT_SOFT && !ih->ih_need) 518 continue; 519 atomic_store_rel_int(&ih->ih_need, 0); 520 CTR6(KTR_INTR, 521 "%s: pid %d ih=%p: %p(%p) flg=%x", __func__, 522 p->p_pid, (void *)ih, 523 (void *)ih->ih_handler, ih->ih_argument, 524 ih->ih_flags); 525 526 if ((ih->ih_flags & IH_DEAD) != 0) { 527 mtx_lock(&ithd->it_lock); 528 TAILQ_REMOVE(&ithd->it_handlers, ih, 529 ih_next); 530 wakeup(ih); 531 mtx_unlock(&ithd->it_lock); 532 goto restart; 533 } 534 if ((ih->ih_flags & IH_MPSAFE) == 0) 535 mtx_lock(&Giant); 536 ih->ih_handler(ih->ih_argument); 537 if ((ih->ih_flags & IH_MPSAFE) == 0) 538 mtx_unlock(&Giant); 539 } 540 } 541 542 /* 543 * Processed all our interrupts. Now get the sched 544 * lock. This may take a while and it_need may get 545 * set again, so we have to check it again. 546 */ 547 mtx_assert(&Giant, MA_NOTOWNED); 548 mtx_lock_spin(&sched_lock); 549 if (!ithd->it_need) { 550 /* 551 * Should we call this earlier in the loop above? 552 */ 553 if (ithd->it_enable != NULL) 554 ithd->it_enable(ithd->it_vector); 555 TD_SET_IWAIT(td); /* we're idle */ 556 p->p_stats->p_ru.ru_nvcsw++; 557 CTR2(KTR_INTR, "%s: pid %d: done", __func__, p->p_pid); 558 mi_switch(); 559 CTR2(KTR_INTR, "%s: pid %d: resumed", __func__, p->p_pid); 560 } 561 mtx_unlock_spin(&sched_lock); 562 } 563 } 564 565 /* 566 * Start standard software interrupt threads 567 */ 568 static void 569 start_softintr(void *dummy) 570 { 571 572 if (swi_add(&clk_ithd, "clock", softclock, NULL, SWI_CLOCK, 573 INTR_MPSAFE, &softclock_ih) || 574 swi_add(NULL, "vm", swi_vm, NULL, SWI_VM, 0, &vm_ih)) 575 panic("died while creating standard software ithreads"); 576 577 PROC_LOCK(clk_ithd->it_td->td_proc); 578 clk_ithd->it_td->td_proc->p_flag |= P_NOLOAD; 579 PROC_UNLOCK(clk_ithd->it_td->td_proc); 580 } 581 SYSINIT(start_softintr, SI_SUB_SOFTINTR, SI_ORDER_FIRST, start_softintr, NULL) 582 583 /* 584 * Sysctls used by systat and others: hw.intrnames and hw.intrcnt. 585 * The data for this machine dependent, and the declarations are in machine 586 * dependent code. The layout of intrnames and intrcnt however is machine 587 * independent. 588 * 589 * We do not know the length of intrcnt and intrnames at compile time, so 590 * calculate things at run time. 591 */ 592 static int 593 sysctl_intrnames(SYSCTL_HANDLER_ARGS) 594 { 595 return (sysctl_handle_opaque(oidp, intrnames, eintrnames - intrnames, 596 req)); 597 } 598 599 SYSCTL_PROC(_hw, OID_AUTO, intrnames, CTLTYPE_OPAQUE | CTLFLAG_RD, 600 NULL, 0, sysctl_intrnames, "", "Interrupt Names"); 601 602 static int 603 sysctl_intrcnt(SYSCTL_HANDLER_ARGS) 604 { 605 return (sysctl_handle_opaque(oidp, intrcnt, 606 (char *)eintrcnt - (char *)intrcnt, req)); 607 } 608 609 SYSCTL_PROC(_hw, OID_AUTO, intrcnt, CTLTYPE_OPAQUE | CTLFLAG_RD, 610 NULL, 0, sysctl_intrcnt, "", "Interrupt Counts"); 611