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_deepest_sleep = 0; /* Deepest Cx state available. */ 58 int cpu_disable_c2_sleep = 0; /* Timer dies in C2. */ 59 int cpu_disable_c3_sleep = 0; /* Timer dies in C3. */ 60 61 static void setuptimer(void); 62 static void loadtimer(sbintime_t now, int first); 63 static int doconfigtimer(void); 64 static void configtimer(int start); 65 static int round_freq(struct eventtimer *et, int freq); 66 67 static sbintime_t getnextcpuevent(int idle); 68 static sbintime_t getnextevent(void); 69 static int handleevents(sbintime_t now, int fake); 70 71 static struct mtx et_hw_mtx; 72 73 #define ET_HW_LOCK(state) \ 74 { \ 75 if (timer->et_flags & ET_FLAGS_PERCPU) \ 76 mtx_lock_spin(&(state)->et_hw_mtx); \ 77 else \ 78 mtx_lock_spin(&et_hw_mtx); \ 79 } 80 81 #define ET_HW_UNLOCK(state) \ 82 { \ 83 if (timer->et_flags & ET_FLAGS_PERCPU) \ 84 mtx_unlock_spin(&(state)->et_hw_mtx); \ 85 else \ 86 mtx_unlock_spin(&et_hw_mtx); \ 87 } 88 89 static struct eventtimer *timer = NULL; 90 static sbintime_t timerperiod; /* Timer period for periodic mode. */ 91 static sbintime_t statperiod; /* statclock() events period. */ 92 static sbintime_t profperiod; /* profclock() events period. */ 93 static sbintime_t nexttick; /* Next global timer tick time. */ 94 static u_int busy = 1; /* Reconfiguration is in progress. */ 95 static int profiling; /* Profiling events enabled. */ 96 97 static char timername[32]; /* Wanted timer. */ 98 TUNABLE_STR("kern.eventtimer.timer", timername, sizeof(timername)); 99 100 static int singlemul; /* Multiplier for periodic mode. */ 101 SYSCTL_INT(_kern_eventtimer, OID_AUTO, singlemul, CTLFLAG_RWTUN, &singlemul, 102 0, "Multiplier for periodic mode"); 103 104 static u_int idletick; /* Run periodic events when idle. */ 105 SYSCTL_UINT(_kern_eventtimer, OID_AUTO, idletick, CTLFLAG_RWTUN, &idletick, 106 0, "Run periodic events when idle"); 107 108 static int periodic; /* Periodic or one-shot mode. */ 109 static int want_periodic; /* What mode to prefer. */ 110 TUNABLE_INT("kern.eventtimer.periodic", &want_periodic); 111 112 struct pcpu_state { 113 struct mtx et_hw_mtx; /* Per-CPU timer mutex. */ 114 u_int action; /* Reconfiguration requests. */ 115 u_int handle; /* Immediate handle resuests. */ 116 sbintime_t now; /* Last tick time. */ 117 sbintime_t nextevent; /* Next scheduled event on this CPU. */ 118 sbintime_t nexttick; /* Next timer tick time. */ 119 sbintime_t nexthard; /* Next hardclock() event. */ 120 sbintime_t nextstat; /* Next statclock() event. */ 121 sbintime_t nextprof; /* Next profclock() event. */ 122 sbintime_t nextcall; /* Next callout event. */ 123 sbintime_t nextcallopt; /* Next optional callout event. */ 124 int ipi; /* This CPU needs IPI. */ 125 int idle; /* This CPU is in idle mode. */ 126 }; 127 128 static DPCPU_DEFINE(struct pcpu_state, timerstate); 129 DPCPU_DEFINE(sbintime_t, hardclocktime); 130 131 /* 132 * Timer broadcast IPI handler. 133 */ 134 int 135 hardclockintr(void) 136 { 137 sbintime_t now; 138 struct pcpu_state *state; 139 int done; 140 141 if (doconfigtimer() || busy) 142 return (FILTER_HANDLED); 143 state = DPCPU_PTR(timerstate); 144 now = state->now; 145 CTR3(KTR_SPARE2, "ipi at %d: now %d.%08x", 146 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff)); 147 done = handleevents(now, 0); 148 return (done ? FILTER_HANDLED : FILTER_STRAY); 149 } 150 151 /* 152 * Handle all events for specified time on this CPU 153 */ 154 static int 155 handleevents(sbintime_t now, int fake) 156 { 157 sbintime_t t, *hct; 158 struct trapframe *frame; 159 struct pcpu_state *state; 160 int usermode; 161 int done, runs; 162 163 CTR3(KTR_SPARE2, "handle at %d: now %d.%08x", 164 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff)); 165 done = 0; 166 if (fake) { 167 frame = NULL; 168 usermode = 0; 169 } else { 170 frame = curthread->td_intr_frame; 171 usermode = TRAPF_USERMODE(frame); 172 } 173 174 state = DPCPU_PTR(timerstate); 175 176 runs = 0; 177 while (now >= state->nexthard) { 178 state->nexthard += tick_sbt; 179 runs++; 180 } 181 if (runs) { 182 hct = DPCPU_PTR(hardclocktime); 183 *hct = state->nexthard - tick_sbt; 184 if (fake < 2) { 185 hardclock_cnt(runs, usermode); 186 done = 1; 187 } 188 } 189 runs = 0; 190 while (now >= state->nextstat) { 191 state->nextstat += statperiod; 192 runs++; 193 } 194 if (runs && fake < 2) { 195 statclock_cnt(runs, usermode); 196 done = 1; 197 } 198 if (profiling) { 199 runs = 0; 200 while (now >= state->nextprof) { 201 state->nextprof += profperiod; 202 runs++; 203 } 204 if (runs && !fake) { 205 profclock_cnt(runs, usermode, TRAPF_PC(frame)); 206 done = 1; 207 } 208 } else 209 state->nextprof = state->nextstat; 210 if (now >= state->nextcallopt) { 211 state->nextcall = state->nextcallopt = SBT_MAX; 212 callout_process(now); 213 } 214 215 t = getnextcpuevent(0); 216 ET_HW_LOCK(state); 217 if (!busy) { 218 state->idle = 0; 219 state->nextevent = t; 220 loadtimer(now, (fake == 2) && 221 (timer->et_flags & ET_FLAGS_PERCPU)); 222 } 223 ET_HW_UNLOCK(state); 224 return (done); 225 } 226 227 /* 228 * Schedule binuptime of the next event on current CPU. 229 */ 230 static sbintime_t 231 getnextcpuevent(int idle) 232 { 233 sbintime_t event; 234 struct pcpu_state *state; 235 u_int hardfreq; 236 237 state = DPCPU_PTR(timerstate); 238 /* Handle hardclock() events, skipping some if CPU is idle. */ 239 event = state->nexthard; 240 if (idle) { 241 hardfreq = (u_int)hz / 2; 242 if (tc_min_ticktock_freq > 2 243 #ifdef SMP 244 && curcpu == CPU_FIRST() 245 #endif 246 ) 247 hardfreq = hz / tc_min_ticktock_freq; 248 if (hardfreq > 1) 249 event += tick_sbt * (hardfreq - 1); 250 } 251 /* Handle callout events. */ 252 if (event > state->nextcall) 253 event = state->nextcall; 254 if (!idle) { /* If CPU is active - handle other types of events. */ 255 if (event > state->nextstat) 256 event = state->nextstat; 257 if (profiling && event > state->nextprof) 258 event = state->nextprof; 259 } 260 return (event); 261 } 262 263 /* 264 * Schedule binuptime of the next event on all CPUs. 265 */ 266 static sbintime_t 267 getnextevent(void) 268 { 269 struct pcpu_state *state; 270 sbintime_t event; 271 #ifdef SMP 272 int cpu; 273 #endif 274 int c; 275 276 state = DPCPU_PTR(timerstate); 277 event = state->nextevent; 278 c = -1; 279 #ifdef SMP 280 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0) { 281 CPU_FOREACH(cpu) { 282 state = DPCPU_ID_PTR(cpu, timerstate); 283 if (event > state->nextevent) { 284 event = state->nextevent; 285 c = cpu; 286 } 287 } 288 } 289 #endif 290 CTR4(KTR_SPARE2, "next at %d: next %d.%08x by %d", 291 curcpu, (int)(event >> 32), (u_int)(event & 0xffffffff), c); 292 return (event); 293 } 294 295 /* Hardware timer callback function. */ 296 static void 297 timercb(struct eventtimer *et, void *arg) 298 { 299 sbintime_t now; 300 sbintime_t *next; 301 struct pcpu_state *state; 302 #ifdef SMP 303 int cpu, bcast; 304 #endif 305 306 /* Do not touch anything if somebody reconfiguring timers. */ 307 if (busy) 308 return; 309 /* Update present and next tick times. */ 310 state = DPCPU_PTR(timerstate); 311 if (et->et_flags & ET_FLAGS_PERCPU) { 312 next = &state->nexttick; 313 } else 314 next = &nexttick; 315 now = sbinuptime(); 316 if (periodic) 317 *next = now + timerperiod; 318 else 319 *next = -1; /* Next tick is not scheduled yet. */ 320 state->now = now; 321 CTR3(KTR_SPARE2, "intr at %d: now %d.%08x", 322 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff)); 323 324 #ifdef SMP 325 /* Prepare broadcasting to other CPUs for non-per-CPU timers. */ 326 bcast = 0; 327 if ((et->et_flags & ET_FLAGS_PERCPU) == 0 && smp_started) { 328 CPU_FOREACH(cpu) { 329 state = DPCPU_ID_PTR(cpu, timerstate); 330 ET_HW_LOCK(state); 331 state->now = now; 332 if (now >= state->nextevent) { 333 state->nextevent += SBT_1S; 334 if (curcpu != cpu) { 335 state->ipi = 1; 336 bcast = 1; 337 } 338 } 339 ET_HW_UNLOCK(state); 340 } 341 } 342 #endif 343 344 /* Handle events for this time on this CPU. */ 345 handleevents(now, 0); 346 347 #ifdef SMP 348 /* Broadcast interrupt to other CPUs for non-per-CPU timers. */ 349 if (bcast) { 350 CPU_FOREACH(cpu) { 351 if (curcpu == cpu) 352 continue; 353 state = DPCPU_ID_PTR(cpu, timerstate); 354 if (state->ipi) { 355 state->ipi = 0; 356 ipi_cpu(cpu, IPI_HARDCLOCK); 357 } 358 } 359 } 360 #endif 361 } 362 363 /* 364 * Load new value into hardware timer. 365 */ 366 static void 367 loadtimer(sbintime_t now, int start) 368 { 369 struct pcpu_state *state; 370 sbintime_t new; 371 sbintime_t *next; 372 uint64_t tmp; 373 int eq; 374 375 if (timer->et_flags & ET_FLAGS_PERCPU) { 376 state = DPCPU_PTR(timerstate); 377 next = &state->nexttick; 378 } else 379 next = &nexttick; 380 if (periodic) { 381 if (start) { 382 /* 383 * Try to start all periodic timers aligned 384 * to period to make events synchronous. 385 */ 386 tmp = now % timerperiod; 387 new = timerperiod - tmp; 388 if (new < tmp) /* Left less then passed. */ 389 new += timerperiod; 390 CTR5(KTR_SPARE2, "load p at %d: now %d.%08x first in %d.%08x", 391 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff), 392 (int)(new >> 32), (u_int)(new & 0xffffffff)); 393 *next = new + now; 394 et_start(timer, new, timerperiod); 395 } 396 } else { 397 new = getnextevent(); 398 eq = (new == *next); 399 CTR4(KTR_SPARE2, "load at %d: next %d.%08x eq %d", 400 curcpu, (int)(new >> 32), (u_int)(new & 0xffffffff), eq); 401 if (!eq) { 402 *next = new; 403 et_start(timer, new - now, 0); 404 } 405 } 406 } 407 408 /* 409 * Prepare event timer parameters after configuration changes. 410 */ 411 static void 412 setuptimer(void) 413 { 414 int freq; 415 416 if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0) 417 periodic = 0; 418 else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0) 419 periodic = 1; 420 singlemul = MIN(MAX(singlemul, 1), 20); 421 freq = hz * singlemul; 422 while (freq < (profiling ? profhz : stathz)) 423 freq += hz; 424 freq = round_freq(timer, freq); 425 timerperiod = SBT_1S / freq; 426 } 427 428 /* 429 * Reconfigure specified per-CPU timer on other CPU. Called from IPI handler. 430 */ 431 static int 432 doconfigtimer(void) 433 { 434 sbintime_t now; 435 struct pcpu_state *state; 436 437 state = DPCPU_PTR(timerstate); 438 switch (atomic_load_acq_int(&state->action)) { 439 case 1: 440 now = sbinuptime(); 441 ET_HW_LOCK(state); 442 loadtimer(now, 1); 443 ET_HW_UNLOCK(state); 444 state->handle = 0; 445 atomic_store_rel_int(&state->action, 0); 446 return (1); 447 case 2: 448 ET_HW_LOCK(state); 449 et_stop(timer); 450 ET_HW_UNLOCK(state); 451 state->handle = 0; 452 atomic_store_rel_int(&state->action, 0); 453 return (1); 454 } 455 if (atomic_readandclear_int(&state->handle) && !busy) { 456 now = sbinuptime(); 457 handleevents(now, 0); 458 return (1); 459 } 460 return (0); 461 } 462 463 /* 464 * Reconfigure specified timer. 465 * For per-CPU timers use IPI to make other CPUs to reconfigure. 466 */ 467 static void 468 configtimer(int start) 469 { 470 sbintime_t now, next; 471 struct pcpu_state *state; 472 int cpu; 473 474 if (start) { 475 setuptimer(); 476 now = sbinuptime(); 477 } else 478 now = 0; 479 critical_enter(); 480 ET_HW_LOCK(DPCPU_PTR(timerstate)); 481 if (start) { 482 /* Initialize time machine parameters. */ 483 next = now + timerperiod; 484 if (periodic) 485 nexttick = next; 486 else 487 nexttick = -1; 488 CPU_FOREACH(cpu) { 489 state = DPCPU_ID_PTR(cpu, timerstate); 490 state->now = now; 491 if (!smp_started && cpu != CPU_FIRST()) 492 state->nextevent = SBT_MAX; 493 else 494 state->nextevent = next; 495 if (periodic) 496 state->nexttick = next; 497 else 498 state->nexttick = -1; 499 state->nexthard = next; 500 state->nextstat = next; 501 state->nextprof = next; 502 state->nextcall = next; 503 state->nextcallopt = next; 504 hardclock_sync(cpu); 505 } 506 busy = 0; 507 /* Start global timer or per-CPU timer of this CPU. */ 508 loadtimer(now, 1); 509 } else { 510 busy = 1; 511 /* Stop global timer or per-CPU timer of this CPU. */ 512 et_stop(timer); 513 } 514 ET_HW_UNLOCK(DPCPU_PTR(timerstate)); 515 #ifdef SMP 516 /* If timer is global or there is no other CPUs yet - we are done. */ 517 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || !smp_started) { 518 critical_exit(); 519 return; 520 } 521 /* Set reconfigure flags for other CPUs. */ 522 CPU_FOREACH(cpu) { 523 state = DPCPU_ID_PTR(cpu, timerstate); 524 atomic_store_rel_int(&state->action, 525 (cpu == curcpu) ? 0 : ( start ? 1 : 2)); 526 } 527 /* Broadcast reconfigure IPI. */ 528 ipi_all_but_self(IPI_HARDCLOCK); 529 /* Wait for reconfiguration completed. */ 530 restart: 531 cpu_spinwait(); 532 CPU_FOREACH(cpu) { 533 if (cpu == curcpu) 534 continue; 535 state = DPCPU_ID_PTR(cpu, timerstate); 536 if (atomic_load_acq_int(&state->action)) 537 goto restart; 538 } 539 #endif 540 critical_exit(); 541 } 542 543 /* 544 * Calculate nearest frequency supported by hardware timer. 545 */ 546 static int 547 round_freq(struct eventtimer *et, int freq) 548 { 549 uint64_t div; 550 551 if (et->et_frequency != 0) { 552 div = lmax((et->et_frequency + freq / 2) / freq, 1); 553 if (et->et_flags & ET_FLAGS_POW2DIV) 554 div = 1 << (flsl(div + div / 2) - 1); 555 freq = (et->et_frequency + div / 2) / div; 556 } 557 if (et->et_min_period > SBT_1S) 558 panic("Event timer \"%s\" doesn't support sub-second periods!", 559 et->et_name); 560 else if (et->et_min_period != 0) 561 freq = min(freq, SBT2FREQ(et->et_min_period)); 562 if (et->et_max_period < SBT_1S && et->et_max_period != 0) 563 freq = max(freq, SBT2FREQ(et->et_max_period)); 564 return (freq); 565 } 566 567 /* 568 * Configure and start event timers (BSP part). 569 */ 570 void 571 cpu_initclocks_bsp(void) 572 { 573 struct pcpu_state *state; 574 int base, div, cpu; 575 576 mtx_init(&et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN); 577 CPU_FOREACH(cpu) { 578 state = DPCPU_ID_PTR(cpu, timerstate); 579 mtx_init(&state->et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN); 580 state->nextcall = SBT_MAX; 581 state->nextcallopt = SBT_MAX; 582 } 583 periodic = want_periodic; 584 /* Grab requested timer or the best of present. */ 585 if (timername[0]) 586 timer = et_find(timername, 0, 0); 587 if (timer == NULL && periodic) { 588 timer = et_find(NULL, 589 ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC); 590 } 591 if (timer == NULL) { 592 timer = et_find(NULL, 593 ET_FLAGS_ONESHOT, ET_FLAGS_ONESHOT); 594 } 595 if (timer == NULL && !periodic) { 596 timer = et_find(NULL, 597 ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC); 598 } 599 if (timer == NULL) 600 panic("No usable event timer found!"); 601 et_init(timer, timercb, NULL, NULL); 602 603 /* Adapt to timer capabilities. */ 604 if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0) 605 periodic = 0; 606 else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0) 607 periodic = 1; 608 if (timer->et_flags & ET_FLAGS_C3STOP) 609 cpu_disable_c3_sleep++; 610 611 /* 612 * We honor the requested 'hz' value. 613 * We want to run stathz in the neighborhood of 128hz. 614 * We would like profhz to run as often as possible. 615 */ 616 if (singlemul <= 0 || singlemul > 20) { 617 if (hz >= 1500 || (hz % 128) == 0) 618 singlemul = 1; 619 else if (hz >= 750) 620 singlemul = 2; 621 else 622 singlemul = 4; 623 } 624 if (periodic) { 625 base = round_freq(timer, hz * singlemul); 626 singlemul = max((base + hz / 2) / hz, 1); 627 hz = (base + singlemul / 2) / singlemul; 628 if (base <= 128) 629 stathz = base; 630 else { 631 div = base / 128; 632 if (div >= singlemul && (div % singlemul) == 0) 633 div++; 634 stathz = base / div; 635 } 636 profhz = stathz; 637 while ((profhz + stathz) <= 128 * 64) 638 profhz += stathz; 639 profhz = round_freq(timer, profhz); 640 } else { 641 hz = round_freq(timer, hz); 642 stathz = round_freq(timer, 127); 643 profhz = round_freq(timer, stathz * 64); 644 } 645 tick = 1000000 / hz; 646 tick_sbt = SBT_1S / hz; 647 tick_bt = sbttobt(tick_sbt); 648 statperiod = SBT_1S / stathz; 649 profperiod = SBT_1S / profhz; 650 ET_LOCK(); 651 configtimer(1); 652 ET_UNLOCK(); 653 } 654 655 /* 656 * Start per-CPU event timers on APs. 657 */ 658 void 659 cpu_initclocks_ap(void) 660 { 661 sbintime_t now; 662 struct pcpu_state *state; 663 struct thread *td; 664 665 state = DPCPU_PTR(timerstate); 666 now = sbinuptime(); 667 ET_HW_LOCK(state); 668 state->now = now; 669 hardclock_sync(curcpu); 670 spinlock_enter(); 671 ET_HW_UNLOCK(state); 672 td = curthread; 673 td->td_intr_nesting_level++; 674 handleevents(state->now, 2); 675 td->td_intr_nesting_level--; 676 spinlock_exit(); 677 } 678 679 /* 680 * Switch to profiling clock rates. 681 */ 682 void 683 cpu_startprofclock(void) 684 { 685 686 ET_LOCK(); 687 if (profiling == 0) { 688 if (periodic) { 689 configtimer(0); 690 profiling = 1; 691 configtimer(1); 692 } else 693 profiling = 1; 694 } else 695 profiling++; 696 ET_UNLOCK(); 697 } 698 699 /* 700 * Switch to regular clock rates. 701 */ 702 void 703 cpu_stopprofclock(void) 704 { 705 706 ET_LOCK(); 707 if (profiling == 1) { 708 if (periodic) { 709 configtimer(0); 710 profiling = 0; 711 configtimer(1); 712 } else 713 profiling = 0; 714 } else 715 profiling--; 716 ET_UNLOCK(); 717 } 718 719 /* 720 * Switch to idle mode (all ticks handled). 721 */ 722 sbintime_t 723 cpu_idleclock(void) 724 { 725 sbintime_t now, t; 726 struct pcpu_state *state; 727 728 if (idletick || busy || 729 (periodic && (timer->et_flags & ET_FLAGS_PERCPU)) 730 #ifdef DEVICE_POLLING 731 || curcpu == CPU_FIRST() 732 #endif 733 ) 734 return (-1); 735 state = DPCPU_PTR(timerstate); 736 if (periodic) 737 now = state->now; 738 else 739 now = sbinuptime(); 740 CTR3(KTR_SPARE2, "idle at %d: now %d.%08x", 741 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff)); 742 t = getnextcpuevent(1); 743 ET_HW_LOCK(state); 744 state->idle = 1; 745 state->nextevent = t; 746 if (!periodic) 747 loadtimer(now, 0); 748 ET_HW_UNLOCK(state); 749 return (MAX(t - now, 0)); 750 } 751 752 /* 753 * Switch to active mode (skip empty ticks). 754 */ 755 void 756 cpu_activeclock(void) 757 { 758 sbintime_t now; 759 struct pcpu_state *state; 760 struct thread *td; 761 762 state = DPCPU_PTR(timerstate); 763 if (state->idle == 0 || busy) 764 return; 765 if (periodic) 766 now = state->now; 767 else 768 now = sbinuptime(); 769 CTR3(KTR_SPARE2, "active at %d: now %d.%08x", 770 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff)); 771 spinlock_enter(); 772 td = curthread; 773 td->td_intr_nesting_level++; 774 handleevents(now, 1); 775 td->td_intr_nesting_level--; 776 spinlock_exit(); 777 } 778 779 /* 780 * Change the frequency of the given timer. This changes et->et_frequency and 781 * if et is the active timer it reconfigures the timer on all CPUs. This is 782 * intended to be a private interface for the use of et_change_frequency() only. 783 */ 784 void 785 cpu_et_frequency(struct eventtimer *et, uint64_t newfreq) 786 { 787 788 ET_LOCK(); 789 if (et == timer) { 790 configtimer(0); 791 et->et_frequency = newfreq; 792 configtimer(1); 793 } else 794 et->et_frequency = newfreq; 795 ET_UNLOCK(); 796 } 797 798 void 799 cpu_new_callout(int cpu, sbintime_t bt, sbintime_t bt_opt) 800 { 801 struct pcpu_state *state; 802 803 /* Do not touch anything if somebody reconfiguring timers. */ 804 if (busy) 805 return; 806 CTR6(KTR_SPARE2, "new co at %d: on %d at %d.%08x - %d.%08x", 807 curcpu, cpu, (int)(bt_opt >> 32), (u_int)(bt_opt & 0xffffffff), 808 (int)(bt >> 32), (u_int)(bt & 0xffffffff)); 809 state = DPCPU_ID_PTR(cpu, timerstate); 810 ET_HW_LOCK(state); 811 812 /* 813 * If there is callout time already set earlier -- do nothing. 814 * This check may appear redundant because we check already in 815 * callout_process() but this double check guarantees we're safe 816 * with respect to race conditions between interrupts execution 817 * and scheduling. 818 */ 819 state->nextcallopt = bt_opt; 820 if (bt >= state->nextcall) 821 goto done; 822 state->nextcall = bt; 823 /* If there is some other event set earlier -- do nothing. */ 824 if (bt >= state->nextevent) 825 goto done; 826 state->nextevent = bt; 827 /* If timer is periodic -- there is nothing to reprogram. */ 828 if (periodic) 829 goto done; 830 /* If timer is global or of the current CPU -- reprogram it. */ 831 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || cpu == curcpu) { 832 loadtimer(sbinuptime(), 0); 833 done: 834 ET_HW_UNLOCK(state); 835 return; 836 } 837 /* Otherwise make other CPU to reprogram it. */ 838 state->handle = 1; 839 ET_HW_UNLOCK(state); 840 #ifdef SMP 841 ipi_cpu(cpu, IPI_HARDCLOCK); 842 #endif 843 } 844 845 /* 846 * Report or change the active event timers hardware. 847 */ 848 static int 849 sysctl_kern_eventtimer_timer(SYSCTL_HANDLER_ARGS) 850 { 851 char buf[32]; 852 struct eventtimer *et; 853 int error; 854 855 ET_LOCK(); 856 et = timer; 857 snprintf(buf, sizeof(buf), "%s", et->et_name); 858 ET_UNLOCK(); 859 error = sysctl_handle_string(oidp, buf, sizeof(buf), req); 860 ET_LOCK(); 861 et = timer; 862 if (error != 0 || req->newptr == NULL || 863 strcasecmp(buf, et->et_name) == 0) { 864 ET_UNLOCK(); 865 return (error); 866 } 867 et = et_find(buf, 0, 0); 868 if (et == NULL) { 869 ET_UNLOCK(); 870 return (ENOENT); 871 } 872 configtimer(0); 873 et_free(timer); 874 if (et->et_flags & ET_FLAGS_C3STOP) 875 cpu_disable_c3_sleep++; 876 if (timer->et_flags & ET_FLAGS_C3STOP) 877 cpu_disable_c3_sleep--; 878 periodic = want_periodic; 879 timer = et; 880 et_init(timer, timercb, NULL, NULL); 881 configtimer(1); 882 ET_UNLOCK(); 883 return (error); 884 } 885 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, timer, 886 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE, 887 0, 0, sysctl_kern_eventtimer_timer, "A", "Chosen event timer"); 888 889 /* 890 * Report or change the active event timer periodicity. 891 */ 892 static int 893 sysctl_kern_eventtimer_periodic(SYSCTL_HANDLER_ARGS) 894 { 895 int error, val; 896 897 val = periodic; 898 error = sysctl_handle_int(oidp, &val, 0, req); 899 if (error != 0 || req->newptr == NULL) 900 return (error); 901 ET_LOCK(); 902 configtimer(0); 903 periodic = want_periodic = val; 904 configtimer(1); 905 ET_UNLOCK(); 906 return (error); 907 } 908 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, periodic, 909 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 910 0, 0, sysctl_kern_eventtimer_periodic, "I", "Enable event timer periodic mode"); 911 912 #include "opt_ddb.h" 913 914 #ifdef DDB 915 #include <ddb/ddb.h> 916 917 DB_SHOW_COMMAND(clocksource, db_show_clocksource) 918 { 919 struct pcpu_state *st; 920 int c; 921 922 CPU_FOREACH(c) { 923 st = DPCPU_ID_PTR(c, timerstate); 924 db_printf( 925 "CPU %2d: action %d handle %d ipi %d idle %d\n" 926 " now %#jx nevent %#jx (%jd)\n" 927 " ntick %#jx (%jd) nhard %#jx (%jd)\n" 928 " nstat %#jx (%jd) nprof %#jx (%jd)\n" 929 " ncall %#jx (%jd) ncallopt %#jx (%jd)\n", 930 c, st->action, st->handle, st->ipi, st->idle, 931 (uintmax_t)st->now, 932 (uintmax_t)st->nextevent, 933 (uintmax_t)(st->nextevent - st->now) / tick_sbt, 934 (uintmax_t)st->nexttick, 935 (uintmax_t)(st->nexttick - st->now) / tick_sbt, 936 (uintmax_t)st->nexthard, 937 (uintmax_t)(st->nexthard - st->now) / tick_sbt, 938 (uintmax_t)st->nextstat, 939 (uintmax_t)(st->nextstat - st->now) / tick_sbt, 940 (uintmax_t)st->nextprof, 941 (uintmax_t)(st->nextprof - st->now) / tick_sbt, 942 (uintmax_t)st->nextcall, 943 (uintmax_t)(st->nextcall - st->now) / tick_sbt, 944 (uintmax_t)st->nextcallopt, 945 (uintmax_t)(st->nextcallopt - st->now) / tick_sbt); 946 } 947 } 948 949 #endif 950