1 /*- 2 * Copyright (c) 2010-2013 Alexander Motin <mav@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, this list of conditions and the following disclaimer, 10 * without modification, immediately at the beginning of the file. 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 /* 31 * Common routines to manage event timers hardware. 32 */ 33 34 #include "opt_device_polling.h" 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/bus.h> 39 #include <sys/limits.h> 40 #include <sys/lock.h> 41 #include <sys/kdb.h> 42 #include <sys/ktr.h> 43 #include <sys/mutex.h> 44 #include <sys/proc.h> 45 #include <sys/kernel.h> 46 #include <sys/sched.h> 47 #include <sys/smp.h> 48 #include <sys/sysctl.h> 49 #include <sys/timeet.h> 50 #include <sys/timetc.h> 51 52 #include <machine/atomic.h> 53 #include <machine/clock.h> 54 #include <machine/cpu.h> 55 #include <machine/smp.h> 56 57 int cpu_can_deep_sleep = 0; /* C3 state is available. */ 58 int cpu_disable_deep_sleep = 0; /* Timer dies in C3. */ 59 60 static void setuptimer(void); 61 static void loadtimer(sbintime_t now, int first); 62 static int doconfigtimer(void); 63 static void configtimer(int start); 64 static int round_freq(struct eventtimer *et, int freq); 65 66 static sbintime_t getnextcpuevent(int idle); 67 static sbintime_t getnextevent(void); 68 static int handleevents(sbintime_t now, int fake); 69 70 static struct mtx et_hw_mtx; 71 72 #define ET_HW_LOCK(state) \ 73 { \ 74 if (timer->et_flags & ET_FLAGS_PERCPU) \ 75 mtx_lock_spin(&(state)->et_hw_mtx); \ 76 else \ 77 mtx_lock_spin(&et_hw_mtx); \ 78 } 79 80 #define ET_HW_UNLOCK(state) \ 81 { \ 82 if (timer->et_flags & ET_FLAGS_PERCPU) \ 83 mtx_unlock_spin(&(state)->et_hw_mtx); \ 84 else \ 85 mtx_unlock_spin(&et_hw_mtx); \ 86 } 87 88 static struct eventtimer *timer = NULL; 89 static sbintime_t timerperiod; /* Timer period for periodic mode. */ 90 static sbintime_t statperiod; /* statclock() events period. */ 91 static sbintime_t profperiod; /* profclock() events period. */ 92 static sbintime_t nexttick; /* Next global timer tick time. */ 93 static u_int busy = 1; /* Reconfiguration is in progress. */ 94 static int profiling; /* Profiling events enabled. */ 95 96 static char timername[32]; /* Wanted timer. */ 97 TUNABLE_STR("kern.eventtimer.timer", timername, sizeof(timername)); 98 99 static int singlemul; /* Multiplier for periodic mode. */ 100 SYSCTL_INT(_kern_eventtimer, OID_AUTO, singlemul, CTLFLAG_RWTUN, &singlemul, 101 0, "Multiplier for periodic mode"); 102 103 static u_int idletick; /* Run periodic events when idle. */ 104 SYSCTL_UINT(_kern_eventtimer, OID_AUTO, idletick, CTLFLAG_RWTUN, &idletick, 105 0, "Run periodic events when idle"); 106 107 static int periodic; /* Periodic or one-shot mode. */ 108 static int want_periodic; /* What mode to prefer. */ 109 TUNABLE_INT("kern.eventtimer.periodic", &want_periodic); 110 111 struct pcpu_state { 112 struct mtx et_hw_mtx; /* Per-CPU timer mutex. */ 113 u_int action; /* Reconfiguration requests. */ 114 u_int handle; /* Immediate handle resuests. */ 115 sbintime_t now; /* Last tick time. */ 116 sbintime_t nextevent; /* Next scheduled event on this CPU. */ 117 sbintime_t nexttick; /* Next timer tick time. */ 118 sbintime_t nexthard; /* Next hardlock() event. */ 119 sbintime_t nextstat; /* Next statclock() event. */ 120 sbintime_t nextprof; /* Next profclock() event. */ 121 sbintime_t nextcall; /* Next callout event. */ 122 sbintime_t nextcallopt; /* Next optional callout event. */ 123 int ipi; /* This CPU needs IPI. */ 124 int idle; /* This CPU is in idle mode. */ 125 }; 126 127 static DPCPU_DEFINE(struct pcpu_state, timerstate); 128 DPCPU_DEFINE(sbintime_t, hardclocktime); 129 130 /* 131 * Timer broadcast IPI handler. 132 */ 133 int 134 hardclockintr(void) 135 { 136 sbintime_t now; 137 struct pcpu_state *state; 138 int done; 139 140 if (doconfigtimer() || busy) 141 return (FILTER_HANDLED); 142 state = DPCPU_PTR(timerstate); 143 now = state->now; 144 CTR3(KTR_SPARE2, "ipi at %d: now %d.%08x", 145 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff)); 146 done = handleevents(now, 0); 147 return (done ? FILTER_HANDLED : FILTER_STRAY); 148 } 149 150 /* 151 * Handle all events for specified time on this CPU 152 */ 153 static int 154 handleevents(sbintime_t now, int fake) 155 { 156 sbintime_t t, *hct; 157 struct trapframe *frame; 158 struct pcpu_state *state; 159 int usermode; 160 int done, runs; 161 162 CTR3(KTR_SPARE2, "handle at %d: now %d.%08x", 163 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff)); 164 done = 0; 165 if (fake) { 166 frame = NULL; 167 usermode = 0; 168 } else { 169 frame = curthread->td_intr_frame; 170 usermode = TRAPF_USERMODE(frame); 171 } 172 173 state = DPCPU_PTR(timerstate); 174 175 runs = 0; 176 while (now >= state->nexthard) { 177 state->nexthard += tick_sbt; 178 runs++; 179 } 180 if (runs) { 181 hct = DPCPU_PTR(hardclocktime); 182 *hct = state->nexthard - tick_sbt; 183 if (fake < 2) { 184 hardclock_cnt(runs, usermode); 185 done = 1; 186 } 187 } 188 runs = 0; 189 while (now >= state->nextstat) { 190 state->nextstat += statperiod; 191 runs++; 192 } 193 if (runs && fake < 2) { 194 statclock_cnt(runs, usermode); 195 done = 1; 196 } 197 if (profiling) { 198 runs = 0; 199 while (now >= state->nextprof) { 200 state->nextprof += profperiod; 201 runs++; 202 } 203 if (runs && !fake) { 204 profclock_cnt(runs, usermode, TRAPF_PC(frame)); 205 done = 1; 206 } 207 } else 208 state->nextprof = state->nextstat; 209 if (now >= state->nextcallopt) { 210 state->nextcall = state->nextcallopt = SBT_MAX; 211 callout_process(now); 212 } 213 214 t = getnextcpuevent(0); 215 ET_HW_LOCK(state); 216 if (!busy) { 217 state->idle = 0; 218 state->nextevent = t; 219 loadtimer(now, (fake == 2) && 220 (timer->et_flags & ET_FLAGS_PERCPU)); 221 } 222 ET_HW_UNLOCK(state); 223 return (done); 224 } 225 226 /* 227 * Schedule binuptime of the next event on current CPU. 228 */ 229 static sbintime_t 230 getnextcpuevent(int idle) 231 { 232 sbintime_t event; 233 struct pcpu_state *state; 234 u_int hardfreq; 235 236 state = DPCPU_PTR(timerstate); 237 /* Handle hardclock() events, skipping some if CPU is idle. */ 238 event = state->nexthard; 239 if (idle) { 240 hardfreq = (u_int)hz / 2; 241 if (tc_min_ticktock_freq > 2 242 #ifdef SMP 243 && curcpu == CPU_FIRST() 244 #endif 245 ) 246 hardfreq = hz / tc_min_ticktock_freq; 247 if (hardfreq > 1) 248 event += tick_sbt * (hardfreq - 1); 249 } 250 /* Handle callout events. */ 251 if (event > state->nextcall) 252 event = state->nextcall; 253 if (!idle) { /* If CPU is active - handle other types of events. */ 254 if (event > state->nextstat) 255 event = state->nextstat; 256 if (profiling && event > state->nextprof) 257 event = state->nextprof; 258 } 259 return (event); 260 } 261 262 /* 263 * Schedule binuptime of the next event on all CPUs. 264 */ 265 static sbintime_t 266 getnextevent(void) 267 { 268 struct pcpu_state *state; 269 sbintime_t event; 270 #ifdef SMP 271 int cpu; 272 #endif 273 int c; 274 275 state = DPCPU_PTR(timerstate); 276 event = state->nextevent; 277 c = -1; 278 #ifdef SMP 279 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0) { 280 CPU_FOREACH(cpu) { 281 state = DPCPU_ID_PTR(cpu, timerstate); 282 if (event > state->nextevent) { 283 event = state->nextevent; 284 c = cpu; 285 } 286 } 287 } 288 #endif 289 CTR4(KTR_SPARE2, "next at %d: next %d.%08x by %d", 290 curcpu, (int)(event >> 32), (u_int)(event & 0xffffffff), c); 291 return (event); 292 } 293 294 /* Hardware timer callback function. */ 295 static void 296 timercb(struct eventtimer *et, void *arg) 297 { 298 sbintime_t now; 299 sbintime_t *next; 300 struct pcpu_state *state; 301 #ifdef SMP 302 int cpu, bcast; 303 #endif 304 305 /* Do not touch anything if somebody reconfiguring timers. */ 306 if (busy) 307 return; 308 /* Update present and next tick times. */ 309 state = DPCPU_PTR(timerstate); 310 if (et->et_flags & ET_FLAGS_PERCPU) { 311 next = &state->nexttick; 312 } else 313 next = &nexttick; 314 now = sbinuptime(); 315 if (periodic) 316 *next = now + timerperiod; 317 else 318 *next = -1; /* Next tick is not scheduled yet. */ 319 state->now = now; 320 CTR3(KTR_SPARE2, "intr at %d: now %d.%08x", 321 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff)); 322 323 #ifdef SMP 324 /* Prepare broadcasting to other CPUs for non-per-CPU timers. */ 325 bcast = 0; 326 if ((et->et_flags & ET_FLAGS_PERCPU) == 0 && smp_started) { 327 CPU_FOREACH(cpu) { 328 state = DPCPU_ID_PTR(cpu, timerstate); 329 ET_HW_LOCK(state); 330 state->now = now; 331 if (now >= state->nextevent) { 332 state->nextevent += SBT_1S; 333 if (curcpu != cpu) { 334 state->ipi = 1; 335 bcast = 1; 336 } 337 } 338 ET_HW_UNLOCK(state); 339 } 340 } 341 #endif 342 343 /* Handle events for this time on this CPU. */ 344 handleevents(now, 0); 345 346 #ifdef SMP 347 /* Broadcast interrupt to other CPUs for non-per-CPU timers. */ 348 if (bcast) { 349 CPU_FOREACH(cpu) { 350 if (curcpu == cpu) 351 continue; 352 state = DPCPU_ID_PTR(cpu, timerstate); 353 if (state->ipi) { 354 state->ipi = 0; 355 ipi_cpu(cpu, IPI_HARDCLOCK); 356 } 357 } 358 } 359 #endif 360 } 361 362 /* 363 * Load new value into hardware timer. 364 */ 365 static void 366 loadtimer(sbintime_t now, int start) 367 { 368 struct pcpu_state *state; 369 sbintime_t new; 370 sbintime_t *next; 371 uint64_t tmp; 372 int eq; 373 374 if (timer->et_flags & ET_FLAGS_PERCPU) { 375 state = DPCPU_PTR(timerstate); 376 next = &state->nexttick; 377 } else 378 next = &nexttick; 379 if (periodic) { 380 if (start) { 381 /* 382 * Try to start all periodic timers aligned 383 * to period to make events synchronous. 384 */ 385 tmp = now % timerperiod; 386 new = timerperiod - tmp; 387 if (new < tmp) /* Left less then passed. */ 388 new += timerperiod; 389 CTR5(KTR_SPARE2, "load p at %d: now %d.%08x first in %d.%08x", 390 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff), 391 (int)(new >> 32), (u_int)(new & 0xffffffff)); 392 *next = new + now; 393 et_start(timer, new, timerperiod); 394 } 395 } else { 396 new = getnextevent(); 397 eq = (new == *next); 398 CTR4(KTR_SPARE2, "load at %d: next %d.%08x eq %d", 399 curcpu, (int)(new >> 32), (u_int)(new & 0xffffffff), eq); 400 if (!eq) { 401 *next = new; 402 et_start(timer, new - now, 0); 403 } 404 } 405 } 406 407 /* 408 * Prepare event timer parameters after configuration changes. 409 */ 410 static void 411 setuptimer(void) 412 { 413 int freq; 414 415 if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0) 416 periodic = 0; 417 else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0) 418 periodic = 1; 419 singlemul = MIN(MAX(singlemul, 1), 20); 420 freq = hz * singlemul; 421 while (freq < (profiling ? profhz : stathz)) 422 freq += hz; 423 freq = round_freq(timer, freq); 424 timerperiod = SBT_1S / freq; 425 } 426 427 /* 428 * Reconfigure specified per-CPU timer on other CPU. Called from IPI handler. 429 */ 430 static int 431 doconfigtimer(void) 432 { 433 sbintime_t now; 434 struct pcpu_state *state; 435 436 state = DPCPU_PTR(timerstate); 437 switch (atomic_load_acq_int(&state->action)) { 438 case 1: 439 now = sbinuptime(); 440 ET_HW_LOCK(state); 441 loadtimer(now, 1); 442 ET_HW_UNLOCK(state); 443 state->handle = 0; 444 atomic_store_rel_int(&state->action, 0); 445 return (1); 446 case 2: 447 ET_HW_LOCK(state); 448 et_stop(timer); 449 ET_HW_UNLOCK(state); 450 state->handle = 0; 451 atomic_store_rel_int(&state->action, 0); 452 return (1); 453 } 454 if (atomic_readandclear_int(&state->handle) && !busy) { 455 now = sbinuptime(); 456 handleevents(now, 0); 457 return (1); 458 } 459 return (0); 460 } 461 462 /* 463 * Reconfigure specified timer. 464 * For per-CPU timers use IPI to make other CPUs to reconfigure. 465 */ 466 static void 467 configtimer(int start) 468 { 469 sbintime_t now, next; 470 struct pcpu_state *state; 471 int cpu; 472 473 if (start) { 474 setuptimer(); 475 now = sbinuptime(); 476 } else 477 now = 0; 478 critical_enter(); 479 ET_HW_LOCK(DPCPU_PTR(timerstate)); 480 if (start) { 481 /* Initialize time machine parameters. */ 482 next = now + timerperiod; 483 if (periodic) 484 nexttick = next; 485 else 486 nexttick = -1; 487 CPU_FOREACH(cpu) { 488 state = DPCPU_ID_PTR(cpu, timerstate); 489 state->now = now; 490 if (!smp_started && cpu != CPU_FIRST()) 491 state->nextevent = SBT_MAX; 492 else 493 state->nextevent = next; 494 if (periodic) 495 state->nexttick = next; 496 else 497 state->nexttick = -1; 498 state->nexthard = next; 499 state->nextstat = next; 500 state->nextprof = next; 501 state->nextcall = next; 502 state->nextcallopt = next; 503 hardclock_sync(cpu); 504 } 505 busy = 0; 506 /* Start global timer or per-CPU timer of this CPU. */ 507 loadtimer(now, 1); 508 } else { 509 busy = 1; 510 /* Stop global timer or per-CPU timer of this CPU. */ 511 et_stop(timer); 512 } 513 ET_HW_UNLOCK(DPCPU_PTR(timerstate)); 514 #ifdef SMP 515 /* If timer is global or there is no other CPUs yet - we are done. */ 516 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || !smp_started) { 517 critical_exit(); 518 return; 519 } 520 /* Set reconfigure flags for other CPUs. */ 521 CPU_FOREACH(cpu) { 522 state = DPCPU_ID_PTR(cpu, timerstate); 523 atomic_store_rel_int(&state->action, 524 (cpu == curcpu) ? 0 : ( start ? 1 : 2)); 525 } 526 /* Broadcast reconfigure IPI. */ 527 ipi_all_but_self(IPI_HARDCLOCK); 528 /* Wait for reconfiguration completed. */ 529 restart: 530 cpu_spinwait(); 531 CPU_FOREACH(cpu) { 532 if (cpu == curcpu) 533 continue; 534 state = DPCPU_ID_PTR(cpu, timerstate); 535 if (atomic_load_acq_int(&state->action)) 536 goto restart; 537 } 538 #endif 539 critical_exit(); 540 } 541 542 /* 543 * Calculate nearest frequency supported by hardware timer. 544 */ 545 static int 546 round_freq(struct eventtimer *et, int freq) 547 { 548 uint64_t div; 549 550 if (et->et_frequency != 0) { 551 div = lmax((et->et_frequency + freq / 2) / freq, 1); 552 if (et->et_flags & ET_FLAGS_POW2DIV) 553 div = 1 << (flsl(div + div / 2) - 1); 554 freq = (et->et_frequency + div / 2) / div; 555 } 556 if (et->et_min_period > SBT_1S) 557 panic("Event timer \"%s\" doesn't support sub-second periods!", 558 et->et_name); 559 else if (et->et_min_period != 0) 560 freq = min(freq, SBT2FREQ(et->et_min_period)); 561 if (et->et_max_period < SBT_1S && et->et_max_period != 0) 562 freq = max(freq, SBT2FREQ(et->et_max_period)); 563 return (freq); 564 } 565 566 /* 567 * Configure and start event timers (BSP part). 568 */ 569 void 570 cpu_initclocks_bsp(void) 571 { 572 struct pcpu_state *state; 573 int base, div, cpu; 574 575 mtx_init(&et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN); 576 CPU_FOREACH(cpu) { 577 state = DPCPU_ID_PTR(cpu, timerstate); 578 mtx_init(&state->et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN); 579 state->nextcall = SBT_MAX; 580 state->nextcallopt = SBT_MAX; 581 } 582 periodic = want_periodic; 583 /* Grab requested timer or the best of present. */ 584 if (timername[0]) 585 timer = et_find(timername, 0, 0); 586 if (timer == NULL && periodic) { 587 timer = et_find(NULL, 588 ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC); 589 } 590 if (timer == NULL) { 591 timer = et_find(NULL, 592 ET_FLAGS_ONESHOT, ET_FLAGS_ONESHOT); 593 } 594 if (timer == NULL && !periodic) { 595 timer = et_find(NULL, 596 ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC); 597 } 598 if (timer == NULL) 599 panic("No usable event timer found!"); 600 et_init(timer, timercb, NULL, NULL); 601 602 /* Adapt to timer capabilities. */ 603 if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0) 604 periodic = 0; 605 else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0) 606 periodic = 1; 607 if (timer->et_flags & ET_FLAGS_C3STOP) 608 cpu_disable_deep_sleep++; 609 610 /* 611 * We honor the requested 'hz' value. 612 * We want to run stathz in the neighborhood of 128hz. 613 * We would like profhz to run as often as possible. 614 */ 615 if (singlemul <= 0 || singlemul > 20) { 616 if (hz >= 1500 || (hz % 128) == 0) 617 singlemul = 1; 618 else if (hz >= 750) 619 singlemul = 2; 620 else 621 singlemul = 4; 622 } 623 if (periodic) { 624 base = round_freq(timer, hz * singlemul); 625 singlemul = max((base + hz / 2) / hz, 1); 626 hz = (base + singlemul / 2) / singlemul; 627 if (base <= 128) 628 stathz = base; 629 else { 630 div = base / 128; 631 if (div >= singlemul && (div % singlemul) == 0) 632 div++; 633 stathz = base / div; 634 } 635 profhz = stathz; 636 while ((profhz + stathz) <= 128 * 64) 637 profhz += stathz; 638 profhz = round_freq(timer, profhz); 639 } else { 640 hz = round_freq(timer, hz); 641 stathz = round_freq(timer, 127); 642 profhz = round_freq(timer, stathz * 64); 643 } 644 tick = 1000000 / hz; 645 tick_sbt = SBT_1S / hz; 646 tick_bt = sbttobt(tick_sbt); 647 statperiod = SBT_1S / stathz; 648 profperiod = SBT_1S / profhz; 649 ET_LOCK(); 650 configtimer(1); 651 ET_UNLOCK(); 652 } 653 654 /* 655 * Start per-CPU event timers on APs. 656 */ 657 void 658 cpu_initclocks_ap(void) 659 { 660 sbintime_t now; 661 struct pcpu_state *state; 662 struct thread *td; 663 664 state = DPCPU_PTR(timerstate); 665 now = sbinuptime(); 666 ET_HW_LOCK(state); 667 state->now = now; 668 hardclock_sync(curcpu); 669 spinlock_enter(); 670 ET_HW_UNLOCK(state); 671 td = curthread; 672 td->td_intr_nesting_level++; 673 handleevents(state->now, 2); 674 td->td_intr_nesting_level--; 675 spinlock_exit(); 676 } 677 678 /* 679 * Switch to profiling clock rates. 680 */ 681 void 682 cpu_startprofclock(void) 683 { 684 685 ET_LOCK(); 686 if (profiling == 0) { 687 if (periodic) { 688 configtimer(0); 689 profiling = 1; 690 configtimer(1); 691 } else 692 profiling = 1; 693 } else 694 profiling++; 695 ET_UNLOCK(); 696 } 697 698 /* 699 * Switch to regular clock rates. 700 */ 701 void 702 cpu_stopprofclock(void) 703 { 704 705 ET_LOCK(); 706 if (profiling == 1) { 707 if (periodic) { 708 configtimer(0); 709 profiling = 0; 710 configtimer(1); 711 } else 712 profiling = 0; 713 } else 714 profiling--; 715 ET_UNLOCK(); 716 } 717 718 /* 719 * Switch to idle mode (all ticks handled). 720 */ 721 sbintime_t 722 cpu_idleclock(void) 723 { 724 sbintime_t now, t; 725 struct pcpu_state *state; 726 727 if (idletick || busy || 728 (periodic && (timer->et_flags & ET_FLAGS_PERCPU)) 729 #ifdef DEVICE_POLLING 730 || curcpu == CPU_FIRST() 731 #endif 732 ) 733 return (-1); 734 state = DPCPU_PTR(timerstate); 735 if (periodic) 736 now = state->now; 737 else 738 now = sbinuptime(); 739 CTR3(KTR_SPARE2, "idle at %d: now %d.%08x", 740 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff)); 741 t = getnextcpuevent(1); 742 ET_HW_LOCK(state); 743 state->idle = 1; 744 state->nextevent = t; 745 if (!periodic) 746 loadtimer(now, 0); 747 ET_HW_UNLOCK(state); 748 return (MAX(t - now, 0)); 749 } 750 751 /* 752 * Switch to active mode (skip empty ticks). 753 */ 754 void 755 cpu_activeclock(void) 756 { 757 sbintime_t now; 758 struct pcpu_state *state; 759 struct thread *td; 760 761 state = DPCPU_PTR(timerstate); 762 if (state->idle == 0 || busy) 763 return; 764 if (periodic) 765 now = state->now; 766 else 767 now = sbinuptime(); 768 CTR3(KTR_SPARE2, "active at %d: now %d.%08x", 769 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff)); 770 spinlock_enter(); 771 td = curthread; 772 td->td_intr_nesting_level++; 773 handleevents(now, 1); 774 td->td_intr_nesting_level--; 775 spinlock_exit(); 776 } 777 778 /* 779 * Change the frequency of the given timer. This changes et->et_frequency and 780 * if et is the active timer it reconfigures the timer on all CPUs. This is 781 * intended to be a private interface for the use of et_change_frequency() only. 782 */ 783 void 784 cpu_et_frequency(struct eventtimer *et, uint64_t newfreq) 785 { 786 787 ET_LOCK(); 788 if (et == timer) { 789 configtimer(0); 790 et->et_frequency = newfreq; 791 configtimer(1); 792 } else 793 et->et_frequency = newfreq; 794 ET_UNLOCK(); 795 } 796 797 void 798 cpu_new_callout(int cpu, sbintime_t bt, sbintime_t bt_opt) 799 { 800 struct pcpu_state *state; 801 802 /* Do not touch anything if somebody reconfiguring timers. */ 803 if (busy) 804 return; 805 CTR6(KTR_SPARE2, "new co at %d: on %d at %d.%08x - %d.%08x", 806 curcpu, cpu, (int)(bt_opt >> 32), (u_int)(bt_opt & 0xffffffff), 807 (int)(bt >> 32), (u_int)(bt & 0xffffffff)); 808 state = DPCPU_ID_PTR(cpu, timerstate); 809 ET_HW_LOCK(state); 810 811 /* 812 * If there is callout time already set earlier -- do nothing. 813 * This check may appear redundant because we check already in 814 * callout_process() but this double check guarantees we're safe 815 * with respect to race conditions between interrupts execution 816 * and scheduling. 817 */ 818 state->nextcallopt = bt_opt; 819 if (bt >= state->nextcall) 820 goto done; 821 state->nextcall = bt; 822 /* If there is some other event set earlier -- do nothing. */ 823 if (bt >= state->nextevent) 824 goto done; 825 state->nextevent = bt; 826 /* If timer is periodic -- there is nothing to reprogram. */ 827 if (periodic) 828 goto done; 829 /* If timer is global or of the current CPU -- reprogram it. */ 830 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || cpu == curcpu) { 831 loadtimer(sbinuptime(), 0); 832 done: 833 ET_HW_UNLOCK(state); 834 return; 835 } 836 /* Otherwise make other CPU to reprogram it. */ 837 state->handle = 1; 838 ET_HW_UNLOCK(state); 839 #ifdef SMP 840 ipi_cpu(cpu, IPI_HARDCLOCK); 841 #endif 842 } 843 844 /* 845 * Report or change the active event timers hardware. 846 */ 847 static int 848 sysctl_kern_eventtimer_timer(SYSCTL_HANDLER_ARGS) 849 { 850 char buf[32]; 851 struct eventtimer *et; 852 int error; 853 854 ET_LOCK(); 855 et = timer; 856 snprintf(buf, sizeof(buf), "%s", et->et_name); 857 ET_UNLOCK(); 858 error = sysctl_handle_string(oidp, buf, sizeof(buf), req); 859 ET_LOCK(); 860 et = timer; 861 if (error != 0 || req->newptr == NULL || 862 strcasecmp(buf, et->et_name) == 0) { 863 ET_UNLOCK(); 864 return (error); 865 } 866 et = et_find(buf, 0, 0); 867 if (et == NULL) { 868 ET_UNLOCK(); 869 return (ENOENT); 870 } 871 configtimer(0); 872 et_free(timer); 873 if (et->et_flags & ET_FLAGS_C3STOP) 874 cpu_disable_deep_sleep++; 875 if (timer->et_flags & ET_FLAGS_C3STOP) 876 cpu_disable_deep_sleep--; 877 periodic = want_periodic; 878 timer = et; 879 et_init(timer, timercb, NULL, NULL); 880 configtimer(1); 881 ET_UNLOCK(); 882 return (error); 883 } 884 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, timer, 885 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE, 886 0, 0, sysctl_kern_eventtimer_timer, "A", "Chosen event timer"); 887 888 /* 889 * Report or change the active event timer periodicity. 890 */ 891 static int 892 sysctl_kern_eventtimer_periodic(SYSCTL_HANDLER_ARGS) 893 { 894 int error, val; 895 896 val = periodic; 897 error = sysctl_handle_int(oidp, &val, 0, req); 898 if (error != 0 || req->newptr == NULL) 899 return (error); 900 ET_LOCK(); 901 configtimer(0); 902 periodic = want_periodic = val; 903 configtimer(1); 904 ET_UNLOCK(); 905 return (error); 906 } 907 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, periodic, 908 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 909 0, 0, sysctl_kern_eventtimer_periodic, "I", "Enable event timer periodic mode"); 910