kern_clocksource.c revision 247329
1/*- 2 * Copyright (c) 2010-2012 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: head/sys/kern/kern_clocksource.c 247329 2013-02-26 18:13:42Z mav $"); 29 30/* 31 * Common routines to manage event timers hardware. 32 */ 33 34#include "opt_device_polling.h" 35#include "opt_kdtrace.h" 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/bus.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#ifdef KDTRACE_HOOKS 58#include <sys/dtrace_bsd.h> 59cyclic_clock_func_t cyclic_clock_func = NULL; 60#endif 61 62int cpu_can_deep_sleep = 0; /* C3 state is available. */ 63int cpu_disable_deep_sleep = 0; /* Timer dies in C3. */ 64 65static void setuptimer(void); 66static void loadtimer(struct bintime *now, int first); 67static int doconfigtimer(void); 68static void configtimer(int start); 69static int round_freq(struct eventtimer *et, int freq); 70 71static void getnextcpuevent(struct bintime *event, int idle); 72static void getnextevent(struct bintime *event); 73static int handleevents(struct bintime *now, int fake); 74#ifdef SMP 75static void cpu_new_callout(int cpu, int ticks); 76#endif 77 78static struct mtx et_hw_mtx; 79 80#define ET_HW_LOCK(state) \ 81 { \ 82 if (timer->et_flags & ET_FLAGS_PERCPU) \ 83 mtx_lock_spin(&(state)->et_hw_mtx); \ 84 else \ 85 mtx_lock_spin(&et_hw_mtx); \ 86 } 87 88#define ET_HW_UNLOCK(state) \ 89 { \ 90 if (timer->et_flags & ET_FLAGS_PERCPU) \ 91 mtx_unlock_spin(&(state)->et_hw_mtx); \ 92 else \ 93 mtx_unlock_spin(&et_hw_mtx); \ 94 } 95 96static struct eventtimer *timer = NULL; 97static struct bintime timerperiod; /* Timer period for periodic mode. */ 98static struct bintime hardperiod; /* hardclock() events period. */ 99static struct bintime statperiod; /* statclock() events period. */ 100static struct bintime profperiod; /* profclock() events period. */ 101static struct bintime nexttick; /* Next global timer tick time. */ 102static struct bintime nexthard; /* Next global hardlock() event. */ 103static u_int busy = 0; /* Reconfiguration is in progress. */ 104static int profiling = 0; /* Profiling events enabled. */ 105 106static char timername[32]; /* Wanted timer. */ 107TUNABLE_STR("kern.eventtimer.timer", timername, sizeof(timername)); 108 109static int singlemul = 0; /* Multiplier for periodic mode. */ 110TUNABLE_INT("kern.eventtimer.singlemul", &singlemul); 111SYSCTL_INT(_kern_eventtimer, OID_AUTO, singlemul, CTLFLAG_RW, &singlemul, 112 0, "Multiplier for periodic mode"); 113 114static u_int idletick = 0; /* Run periodic events when idle. */ 115TUNABLE_INT("kern.eventtimer.idletick", &idletick); 116SYSCTL_UINT(_kern_eventtimer, OID_AUTO, idletick, CTLFLAG_RW, &idletick, 117 0, "Run periodic events when idle"); 118 119static u_int activetick = 1; /* Run all periodic events when active. */ 120TUNABLE_INT("kern.eventtimer.activetick", &activetick); 121SYSCTL_UINT(_kern_eventtimer, OID_AUTO, activetick, CTLFLAG_RW, &activetick, 122 0, "Run all periodic events when active"); 123 124static int periodic = 0; /* Periodic or one-shot mode. */ 125static int want_periodic = 0; /* What mode to prefer. */ 126TUNABLE_INT("kern.eventtimer.periodic", &want_periodic); 127 128struct pcpu_state { 129 struct mtx et_hw_mtx; /* Per-CPU timer mutex. */ 130 u_int action; /* Reconfiguration requests. */ 131 u_int handle; /* Immediate handle resuests. */ 132 struct bintime now; /* Last tick time. */ 133 struct bintime nextevent; /* Next scheduled event on this CPU. */ 134 struct bintime nexttick; /* Next timer tick time. */ 135 struct bintime nexthard; /* Next hardlock() event. */ 136 struct bintime nextstat; /* Next statclock() event. */ 137 struct bintime nextprof; /* Next profclock() event. */ 138#ifdef KDTRACE_HOOKS 139 struct bintime nextcyc; /* Next OpenSolaris cyclics event. */ 140#endif 141 int ipi; /* This CPU needs IPI. */ 142 int idle; /* This CPU is in idle mode. */ 143}; 144 145static DPCPU_DEFINE(struct pcpu_state, timerstate); 146 147#define FREQ2BT(freq, bt) \ 148{ \ 149 (bt)->sec = 0; \ 150 (bt)->frac = ((uint64_t)0x8000000000000000 / (freq)) << 1; \ 151} 152#define BT2FREQ(bt) \ 153 (((uint64_t)0x8000000000000000 + ((bt)->frac >> 2)) / \ 154 ((bt)->frac >> 1)) 155 156/* 157 * Timer broadcast IPI handler. 158 */ 159int 160hardclockintr(void) 161{ 162 struct bintime now; 163 struct pcpu_state *state; 164 int done; 165 166 if (doconfigtimer() || busy) 167 return (FILTER_HANDLED); 168 state = DPCPU_PTR(timerstate); 169 now = state->now; 170 CTR4(KTR_SPARE2, "ipi at %d: now %d.%08x%08x", 171 curcpu, now.sec, (u_int)(now.frac >> 32), 172 (u_int)(now.frac & 0xffffffff)); 173 done = handleevents(&now, 0); 174 return (done ? FILTER_HANDLED : FILTER_STRAY); 175} 176 177/* 178 * Handle all events for specified time on this CPU 179 */ 180static int 181handleevents(struct bintime *now, int fake) 182{ 183 struct bintime t; 184 struct trapframe *frame; 185 struct pcpu_state *state; 186 uintfptr_t pc; 187 int usermode; 188 int done, runs; 189 190 CTR4(KTR_SPARE2, "handle at %d: now %d.%08x%08x", 191 curcpu, now->sec, (u_int)(now->frac >> 32), 192 (u_int)(now->frac & 0xffffffff)); 193 done = 0; 194 if (fake) { 195 frame = NULL; 196 usermode = 0; 197 pc = 0; 198 } else { 199 frame = curthread->td_intr_frame; 200 usermode = TRAPF_USERMODE(frame); 201 pc = TRAPF_PC(frame); 202 } 203 204 state = DPCPU_PTR(timerstate); 205 206 runs = 0; 207 while (bintime_cmp(now, &state->nexthard, >=)) { 208 bintime_addx(&state->nexthard, hardperiod.frac); 209 runs++; 210 } 211 if (runs) { 212 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 && 213 bintime_cmp(&state->nexthard, &nexthard, >)) 214 nexthard = state->nexthard; 215 if (fake < 2) { 216 hardclock_cnt(runs, usermode); 217 done = 1; 218 } 219 } 220 runs = 0; 221 while (bintime_cmp(now, &state->nextstat, >=)) { 222 bintime_addx(&state->nextstat, statperiod.frac); 223 runs++; 224 } 225 if (runs && fake < 2) { 226 statclock_cnt(runs, usermode); 227 done = 1; 228 } 229 if (profiling) { 230 runs = 0; 231 while (bintime_cmp(now, &state->nextprof, >=)) { 232 bintime_addx(&state->nextprof, profperiod.frac); 233 runs++; 234 } 235 if (runs && !fake) { 236 profclock_cnt(runs, usermode, pc); 237 done = 1; 238 } 239 } else 240 state->nextprof = state->nextstat; 241 242#ifdef KDTRACE_HOOKS 243 if (fake == 0 && cyclic_clock_func != NULL && 244 state->nextcyc.sec != -1 && 245 bintime_cmp(now, &state->nextcyc, >=)) { 246 state->nextcyc.sec = -1; 247 (*cyclic_clock_func)(frame); 248 } 249#endif 250 251 getnextcpuevent(&t, 0); 252 if (fake == 2) { 253 state->nextevent = t; 254 return (done); 255 } 256 ET_HW_LOCK(state); 257 if (!busy) { 258 state->idle = 0; 259 state->nextevent = t; 260 loadtimer(now, 0); 261 } 262 ET_HW_UNLOCK(state); 263 return (done); 264} 265 266/* 267 * Schedule binuptime of the next event on current CPU. 268 */ 269static void 270getnextcpuevent(struct bintime *event, int idle) 271{ 272 struct bintime tmp; 273 struct pcpu_state *state; 274 int skip; 275 276 state = DPCPU_PTR(timerstate); 277 /* Handle hardclock() events. */ 278 *event = state->nexthard; 279 if (idle || (!activetick && !profiling && 280 (timer->et_flags & ET_FLAGS_PERCPU) == 0)) { 281 skip = idle ? 4 : (stathz / 2); 282 if (curcpu == CPU_FIRST() && tc_min_ticktock_freq > skip) 283 skip = tc_min_ticktock_freq; 284 skip = callout_tickstofirst(hz / skip) - 1; 285 CTR2(KTR_SPARE2, "skip at %d: %d", curcpu, skip); 286 tmp = hardperiod; 287 bintime_mul(&tmp, skip); 288 bintime_add(event, &tmp); 289 } 290 if (!idle) { /* If CPU is active - handle other types of events. */ 291 if (bintime_cmp(event, &state->nextstat, >)) 292 *event = state->nextstat; 293 if (profiling && bintime_cmp(event, &state->nextprof, >)) 294 *event = state->nextprof; 295 } 296#ifdef KDTRACE_HOOKS 297 if (state->nextcyc.sec != -1 && bintime_cmp(event, &state->nextcyc, >)) 298 *event = state->nextcyc; 299#endif 300} 301 302/* 303 * Schedule binuptime of the next event on all CPUs. 304 */ 305static void 306getnextevent(struct bintime *event) 307{ 308 struct pcpu_state *state; 309#ifdef SMP 310 int cpu; 311#endif 312 int c, nonidle; 313 314 state = DPCPU_PTR(timerstate); 315 *event = state->nextevent; 316 c = curcpu; 317 nonidle = !state->idle; 318 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0) { 319#ifdef SMP 320 if (smp_started) { 321 CPU_FOREACH(cpu) { 322 if (curcpu == cpu) 323 continue; 324 state = DPCPU_ID_PTR(cpu, timerstate); 325 nonidle += !state->idle; 326 if (bintime_cmp(event, &state->nextevent, >)) { 327 *event = state->nextevent; 328 c = cpu; 329 } 330 } 331 } 332#endif 333 if (nonidle != 0 && bintime_cmp(event, &nexthard, >)) 334 *event = nexthard; 335 } 336 CTR5(KTR_SPARE2, "next at %d: next %d.%08x%08x by %d", 337 curcpu, event->sec, (u_int)(event->frac >> 32), 338 (u_int)(event->frac & 0xffffffff), c); 339} 340 341/* Hardware timer callback function. */ 342static void 343timercb(struct eventtimer *et, void *arg) 344{ 345 struct bintime now; 346 struct bintime *next; 347 struct pcpu_state *state; 348#ifdef SMP 349 int cpu, bcast; 350#endif 351 352 /* Do not touch anything if somebody reconfiguring timers. */ 353 if (busy) 354 return; 355 /* Update present and next tick times. */ 356 state = DPCPU_PTR(timerstate); 357 if (et->et_flags & ET_FLAGS_PERCPU) { 358 next = &state->nexttick; 359 } else 360 next = &nexttick; 361 binuptime(&now); 362 if (periodic) { 363 *next = now; 364 bintime_addx(next, timerperiod.frac); /* Next tick in 1 period. */ 365 } else 366 next->sec = -1; /* Next tick is not scheduled yet. */ 367 state->now = now; 368 CTR4(KTR_SPARE2, "intr at %d: now %d.%08x%08x", 369 curcpu, (int)(now.sec), (u_int)(now.frac >> 32), 370 (u_int)(now.frac & 0xffffffff)); 371 372#ifdef SMP 373 /* Prepare broadcasting to other CPUs for non-per-CPU timers. */ 374 bcast = 0; 375 if ((et->et_flags & ET_FLAGS_PERCPU) == 0 && smp_started) { 376 CPU_FOREACH(cpu) { 377 state = DPCPU_ID_PTR(cpu, timerstate); 378 ET_HW_LOCK(state); 379 state->now = now; 380 if (bintime_cmp(&now, &state->nextevent, >=)) { 381 state->nextevent.sec++; 382 if (curcpu != cpu) { 383 state->ipi = 1; 384 bcast = 1; 385 } 386 } 387 ET_HW_UNLOCK(state); 388 } 389 } 390#endif 391 392 /* Handle events for this time on this CPU. */ 393 handleevents(&now, 0); 394 395#ifdef SMP 396 /* Broadcast interrupt to other CPUs for non-per-CPU timers. */ 397 if (bcast) { 398 CPU_FOREACH(cpu) { 399 if (curcpu == cpu) 400 continue; 401 state = DPCPU_ID_PTR(cpu, timerstate); 402 if (state->ipi) { 403 state->ipi = 0; 404 ipi_cpu(cpu, IPI_HARDCLOCK); 405 } 406 } 407 } 408#endif 409} 410 411/* 412 * Load new value into hardware timer. 413 */ 414static void 415loadtimer(struct bintime *now, int start) 416{ 417 struct pcpu_state *state; 418 struct bintime new; 419 struct bintime *next; 420 uint64_t tmp; 421 int eq; 422 423 if (timer->et_flags & ET_FLAGS_PERCPU) { 424 state = DPCPU_PTR(timerstate); 425 next = &state->nexttick; 426 } else 427 next = &nexttick; 428 if (periodic) { 429 if (start) { 430 /* 431 * Try to start all periodic timers aligned 432 * to period to make events synchronous. 433 */ 434 tmp = ((uint64_t)now->sec << 36) + (now->frac >> 28); 435 tmp = (tmp % (timerperiod.frac >> 28)) << 28; 436 new.sec = 0; 437 new.frac = timerperiod.frac - tmp; 438 if (new.frac < tmp) /* Left less then passed. */ 439 bintime_addx(&new, timerperiod.frac); 440 CTR5(KTR_SPARE2, "load p at %d: now %d.%08x first in %d.%08x", 441 curcpu, now->sec, (u_int)(now->frac >> 32), 442 new.sec, (u_int)(new.frac >> 32)); 443 *next = new; 444 bintime_add(next, now); 445 et_start(timer, &new, &timerperiod); 446 } 447 } else { 448 getnextevent(&new); 449 eq = bintime_cmp(&new, next, ==); 450 CTR5(KTR_SPARE2, "load at %d: next %d.%08x%08x eq %d", 451 curcpu, new.sec, (u_int)(new.frac >> 32), 452 (u_int)(new.frac & 0xffffffff), 453 eq); 454 if (!eq) { 455 *next = new; 456 bintime_sub(&new, now); 457 et_start(timer, &new, NULL); 458 } 459 } 460} 461 462/* 463 * Prepare event timer parameters after configuration changes. 464 */ 465static void 466setuptimer(void) 467{ 468 int freq; 469 470 if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0) 471 periodic = 0; 472 else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0) 473 periodic = 1; 474 singlemul = MIN(MAX(singlemul, 1), 20); 475 freq = hz * singlemul; 476 while (freq < (profiling ? profhz : stathz)) 477 freq += hz; 478 freq = round_freq(timer, freq); 479 FREQ2BT(freq, &timerperiod); 480} 481 482/* 483 * Reconfigure specified per-CPU timer on other CPU. Called from IPI handler. 484 */ 485static int 486doconfigtimer(void) 487{ 488 struct bintime now; 489 struct pcpu_state *state; 490 491 state = DPCPU_PTR(timerstate); 492 switch (atomic_load_acq_int(&state->action)) { 493 case 1: 494 binuptime(&now); 495 ET_HW_LOCK(state); 496 loadtimer(&now, 1); 497 ET_HW_UNLOCK(state); 498 state->handle = 0; 499 atomic_store_rel_int(&state->action, 0); 500 return (1); 501 case 2: 502 ET_HW_LOCK(state); 503 et_stop(timer); 504 ET_HW_UNLOCK(state); 505 state->handle = 0; 506 atomic_store_rel_int(&state->action, 0); 507 return (1); 508 } 509 if (atomic_readandclear_int(&state->handle) && !busy) { 510 binuptime(&now); 511 handleevents(&now, 0); 512 return (1); 513 } 514 return (0); 515} 516 517/* 518 * Reconfigure specified timer. 519 * For per-CPU timers use IPI to make other CPUs to reconfigure. 520 */ 521static void 522configtimer(int start) 523{ 524 struct bintime now, next; 525 struct pcpu_state *state; 526 int cpu; 527 528 if (start) { 529 setuptimer(); 530 binuptime(&now); 531 } 532 critical_enter(); 533 ET_HW_LOCK(DPCPU_PTR(timerstate)); 534 if (start) { 535 /* Initialize time machine parameters. */ 536 next = now; 537 bintime_addx(&next, timerperiod.frac); 538 if (periodic) 539 nexttick = next; 540 else 541 nexttick.sec = -1; 542 CPU_FOREACH(cpu) { 543 state = DPCPU_ID_PTR(cpu, timerstate); 544 state->now = now; 545 state->nextevent = next; 546 if (periodic) 547 state->nexttick = next; 548 else 549 state->nexttick.sec = -1; 550 state->nexthard = next; 551 state->nextstat = next; 552 state->nextprof = next; 553 hardclock_sync(cpu); 554 } 555 busy = 0; 556 /* Start global timer or per-CPU timer of this CPU. */ 557 loadtimer(&now, 1); 558 } else { 559 busy = 1; 560 /* Stop global timer or per-CPU timer of this CPU. */ 561 et_stop(timer); 562 } 563 ET_HW_UNLOCK(DPCPU_PTR(timerstate)); 564#ifdef SMP 565 /* If timer is global or there is no other CPUs yet - we are done. */ 566 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || !smp_started) { 567 critical_exit(); 568 return; 569 } 570 /* Set reconfigure flags for other CPUs. */ 571 CPU_FOREACH(cpu) { 572 state = DPCPU_ID_PTR(cpu, timerstate); 573 atomic_store_rel_int(&state->action, 574 (cpu == curcpu) ? 0 : ( start ? 1 : 2)); 575 } 576 /* Broadcast reconfigure IPI. */ 577 ipi_all_but_self(IPI_HARDCLOCK); 578 /* Wait for reconfiguration completed. */ 579restart: 580 cpu_spinwait(); 581 CPU_FOREACH(cpu) { 582 if (cpu == curcpu) 583 continue; 584 state = DPCPU_ID_PTR(cpu, timerstate); 585 if (atomic_load_acq_int(&state->action)) 586 goto restart; 587 } 588#endif 589 critical_exit(); 590} 591 592/* 593 * Calculate nearest frequency supported by hardware timer. 594 */ 595static int 596round_freq(struct eventtimer *et, int freq) 597{ 598 uint64_t div; 599 600 if (et->et_frequency != 0) { 601 div = lmax((et->et_frequency + freq / 2) / freq, 1); 602 if (et->et_flags & ET_FLAGS_POW2DIV) 603 div = 1 << (flsl(div + div / 2) - 1); 604 freq = (et->et_frequency + div / 2) / div; 605 } 606 if (et->et_min_period.sec > 0) 607 panic("Event timer \"%s\" doesn't support sub-second periods!", 608 et->et_name); 609 else if (et->et_min_period.frac != 0) 610 freq = min(freq, BT2FREQ(&et->et_min_period)); 611 if (et->et_max_period.sec == 0 && et->et_max_period.frac != 0) 612 freq = max(freq, BT2FREQ(&et->et_max_period)); 613 return (freq); 614} 615 616/* 617 * Configure and start event timers (BSP part). 618 */ 619void 620cpu_initclocks_bsp(void) 621{ 622 struct pcpu_state *state; 623 int base, div, cpu; 624 625 mtx_init(&et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN); 626 CPU_FOREACH(cpu) { 627 state = DPCPU_ID_PTR(cpu, timerstate); 628 mtx_init(&state->et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN); 629#ifdef KDTRACE_HOOKS 630 state->nextcyc.sec = -1; 631#endif 632 } 633#ifdef SMP 634 callout_new_inserted = cpu_new_callout; 635#endif 636 periodic = want_periodic; 637 /* Grab requested timer or the best of present. */ 638 if (timername[0]) 639 timer = et_find(timername, 0, 0); 640 if (timer == NULL && periodic) { 641 timer = et_find(NULL, 642 ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC); 643 } 644 if (timer == NULL) { 645 timer = et_find(NULL, 646 ET_FLAGS_ONESHOT, ET_FLAGS_ONESHOT); 647 } 648 if (timer == NULL && !periodic) { 649 timer = et_find(NULL, 650 ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC); 651 } 652 if (timer == NULL) 653 panic("No usable event timer found!"); 654 et_init(timer, timercb, NULL, NULL); 655 656 /* Adapt to timer capabilities. */ 657 if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0) 658 periodic = 0; 659 else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0) 660 periodic = 1; 661 if (timer->et_flags & ET_FLAGS_C3STOP) 662 cpu_disable_deep_sleep++; 663 664 /* 665 * We honor the requested 'hz' value. 666 * We want to run stathz in the neighborhood of 128hz. 667 * We would like profhz to run as often as possible. 668 */ 669 if (singlemul <= 0 || singlemul > 20) { 670 if (hz >= 1500 || (hz % 128) == 0) 671 singlemul = 1; 672 else if (hz >= 750) 673 singlemul = 2; 674 else 675 singlemul = 4; 676 } 677 if (periodic) { 678 base = round_freq(timer, hz * singlemul); 679 singlemul = max((base + hz / 2) / hz, 1); 680 hz = (base + singlemul / 2) / singlemul; 681 if (base <= 128) 682 stathz = base; 683 else { 684 div = base / 128; 685 if (div >= singlemul && (div % singlemul) == 0) 686 div++; 687 stathz = base / div; 688 } 689 profhz = stathz; 690 while ((profhz + stathz) <= 128 * 64) 691 profhz += stathz; 692 profhz = round_freq(timer, profhz); 693 } else { 694 hz = round_freq(timer, hz); 695 stathz = round_freq(timer, 127); 696 profhz = round_freq(timer, stathz * 64); 697 } 698 tick = 1000000 / hz; 699 FREQ2BT(hz, &hardperiod); 700 FREQ2BT(stathz, &statperiod); 701 FREQ2BT(profhz, &profperiod); 702 ET_LOCK(); 703 configtimer(1); 704 ET_UNLOCK(); 705} 706 707/* 708 * Start per-CPU event timers on APs. 709 */ 710void 711cpu_initclocks_ap(void) 712{ 713 struct bintime now; 714 struct pcpu_state *state; 715 716 state = DPCPU_PTR(timerstate); 717 binuptime(&now); 718 ET_HW_LOCK(state); 719 state->now = now; 720 hardclock_sync(curcpu); 721 handleevents(&state->now, 2); 722 if (timer->et_flags & ET_FLAGS_PERCPU) 723 loadtimer(&now, 1); 724 ET_HW_UNLOCK(state); 725} 726 727/* 728 * Switch to profiling clock rates. 729 */ 730void 731cpu_startprofclock(void) 732{ 733 734 ET_LOCK(); 735 if (profiling == 0) { 736 if (periodic) { 737 configtimer(0); 738 profiling = 1; 739 configtimer(1); 740 } else 741 profiling = 1; 742 } else 743 profiling++; 744 ET_UNLOCK(); 745} 746 747/* 748 * Switch to regular clock rates. 749 */ 750void 751cpu_stopprofclock(void) 752{ 753 754 ET_LOCK(); 755 if (profiling == 1) { 756 if (periodic) { 757 configtimer(0); 758 profiling = 0; 759 configtimer(1); 760 } else 761 profiling = 0; 762 } else 763 profiling--; 764 ET_UNLOCK(); 765} 766 767/* 768 * Switch to idle mode (all ticks handled). 769 */ 770void 771cpu_idleclock(void) 772{ 773 struct bintime now, t; 774 struct pcpu_state *state; 775 776 if (idletick || busy || 777 (periodic && (timer->et_flags & ET_FLAGS_PERCPU)) 778#ifdef DEVICE_POLLING 779 || curcpu == CPU_FIRST() 780#endif 781 ) 782 return; 783 state = DPCPU_PTR(timerstate); 784 if (periodic) 785 now = state->now; 786 else 787 binuptime(&now); 788 CTR4(KTR_SPARE2, "idle at %d: now %d.%08x%08x", 789 curcpu, now.sec, (u_int)(now.frac >> 32), 790 (u_int)(now.frac & 0xffffffff)); 791 getnextcpuevent(&t, 1); 792 ET_HW_LOCK(state); 793 state->idle = 1; 794 state->nextevent = t; 795 if (!periodic) 796 loadtimer(&now, 0); 797 ET_HW_UNLOCK(state); 798} 799 800/* 801 * Switch to active mode (skip empty ticks). 802 */ 803void 804cpu_activeclock(void) 805{ 806 struct bintime now; 807 struct pcpu_state *state; 808 struct thread *td; 809 810 state = DPCPU_PTR(timerstate); 811 if (state->idle == 0 || busy) 812 return; 813 if (periodic) 814 now = state->now; 815 else 816 binuptime(&now); 817 CTR4(KTR_SPARE2, "active at %d: now %d.%08x%08x", 818 curcpu, now.sec, (u_int)(now.frac >> 32), 819 (u_int)(now.frac & 0xffffffff)); 820 spinlock_enter(); 821 td = curthread; 822 td->td_intr_nesting_level++; 823 handleevents(&now, 1); 824 td->td_intr_nesting_level--; 825 spinlock_exit(); 826} 827 828#ifdef KDTRACE_HOOKS 829void 830clocksource_cyc_set(const struct bintime *t) 831{ 832 struct bintime now; 833 struct pcpu_state *state; 834 835 state = DPCPU_PTR(timerstate); 836 if (periodic) 837 now = state->now; 838 else 839 binuptime(&now); 840 841 CTR4(KTR_SPARE2, "set_cyc at %d: now %d.%08x%08x", 842 curcpu, now.sec, (u_int)(now.frac >> 32), 843 (u_int)(now.frac & 0xffffffff)); 844 CTR4(KTR_SPARE2, "set_cyc at %d: t %d.%08x%08x", 845 curcpu, t->sec, (u_int)(t->frac >> 32), 846 (u_int)(t->frac & 0xffffffff)); 847 848 ET_HW_LOCK(state); 849 if (bintime_cmp(t, &state->nextcyc, ==)) { 850 ET_HW_UNLOCK(state); 851 return; 852 } 853 state->nextcyc = *t; 854 if (bintime_cmp(&state->nextcyc, &state->nextevent, >=)) { 855 ET_HW_UNLOCK(state); 856 return; 857 } 858 state->nextevent = state->nextcyc; 859 if (!periodic) 860 loadtimer(&now, 0); 861 ET_HW_UNLOCK(state); 862} 863#endif 864 865#ifdef SMP 866static void 867cpu_new_callout(int cpu, int ticks) 868{ 869 struct bintime tmp; 870 struct pcpu_state *state; 871 872 CTR3(KTR_SPARE2, "new co at %d: on %d in %d", 873 curcpu, cpu, ticks); 874 state = DPCPU_ID_PTR(cpu, timerstate); 875 ET_HW_LOCK(state); 876 if (state->idle == 0 || busy) { 877 ET_HW_UNLOCK(state); 878 return; 879 } 880 /* 881 * If timer is periodic - just update next event time for target CPU. 882 * If timer is global - there is chance it is already programmed. 883 */ 884 if (periodic || (timer->et_flags & ET_FLAGS_PERCPU) == 0) { 885 tmp = hardperiod; 886 bintime_mul(&tmp, ticks - 1); 887 bintime_add(&tmp, &state->nexthard); 888 if (bintime_cmp(&tmp, &state->nextevent, <)) 889 state->nextevent = tmp; 890 if (periodic || 891 bintime_cmp(&state->nextevent, &nexttick, >=)) { 892 ET_HW_UNLOCK(state); 893 return; 894 } 895 } 896 /* 897 * Otherwise we have to wake that CPU up, as we can't get present 898 * bintime to reprogram global timer from here. If timer is per-CPU, 899 * we by definition can't do it from here. 900 */ 901 ET_HW_UNLOCK(state); 902 if (timer->et_flags & ET_FLAGS_PERCPU) { 903 state->handle = 1; 904 ipi_cpu(cpu, IPI_HARDCLOCK); 905 } else { 906 if (!cpu_idle_wakeup(cpu)) 907 ipi_cpu(cpu, IPI_AST); 908 } 909} 910#endif 911 912/* 913 * Report or change the active event timers hardware. 914 */ 915static int 916sysctl_kern_eventtimer_timer(SYSCTL_HANDLER_ARGS) 917{ 918 char buf[32]; 919 struct eventtimer *et; 920 int error; 921 922 ET_LOCK(); 923 et = timer; 924 snprintf(buf, sizeof(buf), "%s", et->et_name); 925 ET_UNLOCK(); 926 error = sysctl_handle_string(oidp, buf, sizeof(buf), req); 927 ET_LOCK(); 928 et = timer; 929 if (error != 0 || req->newptr == NULL || 930 strcasecmp(buf, et->et_name) == 0) { 931 ET_UNLOCK(); 932 return (error); 933 } 934 et = et_find(buf, 0, 0); 935 if (et == NULL) { 936 ET_UNLOCK(); 937 return (ENOENT); 938 } 939 configtimer(0); 940 et_free(timer); 941 if (et->et_flags & ET_FLAGS_C3STOP) 942 cpu_disable_deep_sleep++; 943 if (timer->et_flags & ET_FLAGS_C3STOP) 944 cpu_disable_deep_sleep--; 945 periodic = want_periodic; 946 timer = et; 947 et_init(timer, timercb, NULL, NULL); 948 configtimer(1); 949 ET_UNLOCK(); 950 return (error); 951} 952SYSCTL_PROC(_kern_eventtimer, OID_AUTO, timer, 953 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE, 954 0, 0, sysctl_kern_eventtimer_timer, "A", "Chosen event timer"); 955 956/* 957 * Report or change the active event timer periodicity. 958 */ 959static int 960sysctl_kern_eventtimer_periodic(SYSCTL_HANDLER_ARGS) 961{ 962 int error, val; 963 964 val = periodic; 965 error = sysctl_handle_int(oidp, &val, 0, req); 966 if (error != 0 || req->newptr == NULL) 967 return (error); 968 ET_LOCK(); 969 configtimer(0); 970 periodic = want_periodic = val; 971 configtimer(1); 972 ET_UNLOCK(); 973 return (error); 974} 975SYSCTL_PROC(_kern_eventtimer, OID_AUTO, periodic, 976 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 977 0, 0, sysctl_kern_eventtimer_periodic, "I", "Enable event timer periodic mode"); 978