sys/kern/kern_clocksource.c

   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("$FreeBSD$");
  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>
  59 cyclic_clock_func_t     cyclic_clock_func = NULL;
  60 #endif
  61
  62 int                     cpu_can_deep_sleep = 0; /* C3 state is available. */
  63 int                     cpu_disable_deep_sleep = 0; /* Timer dies in C3. */
  64
  65 static void             setuptimer(void);
  66 static void             loadtimer(struct bintime *now, int first);
  67 static int              doconfigtimer(void);
  68 static void             configtimer(int start);
  69 static int              round_freq(struct eventtimer *et, int freq);
  70
  71 static void             getnextcpuevent(struct bintime *event, int idle);
  72 static void             getnextevent(struct bintime *event);
  73 static int              handleevents(struct bintime *now, int fake);
  74 #ifdef SMP
  75 static void             cpu_new_callout(int cpu, int ticks);
  76 #endif
  77
  78 static 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
  96 static struct eventtimer *timer = NULL;
  97 static struct bintime   timerperiod;    /* Timer period for periodic mode. */
  98 static struct bintime   hardperiod;     /* hardclock() events period. */
  99 static struct bintime   statperiod;     /* statclock() events period. */
 100 static struct bintime   profperiod;     /* profclock() events period. */
 101 static struct bintime   nexttick;       /* Next global timer tick time. */
 102 static struct bintime   nexthard;       /* Next global hardlock() event. */
 103 static u_int            busy = 0;       /* Reconfiguration is in progress. */
 104 static int              profiling = 0;  /* Profiling events enabled. */
 105
 106 static char             timername[32];  /* Wanted timer. */
 107 TUNABLE_STR("kern.eventtimer.timer", timername, sizeof(timername));
 108
 109 static int              singlemul = 0;  /* Multiplier for periodic mode. */
 110 TUNABLE_INT("kern.eventtimer.singlemul", &singlemul);
 111 SYSCTL_INT(_kern_eventtimer, OID_AUTO, singlemul, CTLFLAG_RW, &singlemul,
 112     0, "Multiplier for periodic mode");
 113
 114 static u_int            idletick = 0;   /* Run periodic events when idle. */
 115 TUNABLE_INT("kern.eventtimer.idletick", &idletick);
 116 SYSCTL_UINT(_kern_eventtimer, OID_AUTO, idletick, CTLFLAG_RW, &idletick,
 117     0, "Run periodic events when idle");
 118
 119 static u_int            activetick = 1; /* Run all periodic events when active. */
 120 TUNABLE_INT("kern.eventtimer.activetick", &activetick);
 121 SYSCTL_UINT(_kern_eventtimer, OID_AUTO, activetick, CTLFLAG_RW, &activetick,
 122     0, "Run all periodic events when active");
 123
 124 static int              periodic = 0;   /* Periodic or one-shot mode. */
 125 static int              want_periodic = 0; /* What mode to prefer. */
 126 TUNABLE_INT("kern.eventtimer.periodic", &want_periodic);
 127
 128 struct 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
 145 static 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  */
 159 int
 160 hardclockintr(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  */
 180 static int
 181 handleevents(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  */
 269 static void
 270 getnextcpuevent(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  */
 305 static void
 306 getnextevent(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. */
 342 static void
 343 timercb(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  */
 414 static void
 415 loadtimer(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  */
 465 static void
 466 setuptimer(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  */
 485 static int
 486 doconfigtimer(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  */
 521 static void
 522 configtimer(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. */
 579 restart:
 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  */
 595 static int
 596 round_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  */
 619 void
 620 cpu_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  */
 710 void
 711 cpu_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  */
 730 void
 731 cpu_startprofclock(void)
 732 {
 733
 734         ET_LOCK();
 735         if (periodic) {
 736                 configtimer(0);
 737                 profiling = 1;
 738                 configtimer(1);
 739         } else
 740                 profiling = 1;
 741         ET_UNLOCK();
 742 }
 743
 744 /*
 745  * Switch to regular clock rates.
 746  */
 747 void
 748 cpu_stopprofclock(void)
 749 {
 750
 751         ET_LOCK();
 752         if (periodic) {
 753                 configtimer(0);
 754                 profiling = 0;
 755                 configtimer(1);
 756         } else
 757                 profiling = 0;
 758         ET_UNLOCK();
 759 }
 760
 761 /*
 762  * Switch to idle mode (all ticks handled).
 763  */
 764 void
 765 cpu_idleclock(void)
 766 {
 767         struct bintime now, t;
 768         struct pcpu_state *state;
 769
 770         if (idletick || busy ||
 771             (periodic && (timer->et_flags & ET_FLAGS_PERCPU))
 772 #ifdef DEVICE_POLLING
 773             || curcpu == CPU_FIRST()
 774 #endif
 775             )
 776                 return;
 777         state = DPCPU_PTR(timerstate);
 778         if (periodic)
 779                 now = state->now;
 780         else
 781                 binuptime(&now);
 782         CTR4(KTR_SPARE2, "idle at %d:    now  %d.%08x%08x",
 783             curcpu, now.sec, (u_int)(now.frac >> 32),
 784                              (u_int)(now.frac & 0xffffffff));
 785         getnextcpuevent(&t, 1);
 786         ET_HW_LOCK(state);
 787         state->idle = 1;
 788         state->nextevent = t;
 789         if (!periodic)
 790                 loadtimer(&now, 0);
 791         ET_HW_UNLOCK(state);
 792 }
 793
 794 /*
 795  * Switch to active mode (skip empty ticks).
 796  */
 797 void
 798 cpu_activeclock(void)
 799 {
 800         struct bintime now;
 801         struct pcpu_state *state;
 802         struct thread *td;
 803
 804         state = DPCPU_PTR(timerstate);
 805         if (state->idle == 0 || busy)
 806                 return;
 807         if (periodic)
 808                 now = state->now;
 809         else
 810                 binuptime(&now);
 811         CTR4(KTR_SPARE2, "active at %d:  now  %d.%08x%08x",
 812             curcpu, now.sec, (u_int)(now.frac >> 32),
 813                              (u_int)(now.frac & 0xffffffff));
 814         spinlock_enter();
 815         td = curthread;
 816         td->td_intr_nesting_level++;
 817         handleevents(&now, 1);
 818         td->td_intr_nesting_level--;
 819         spinlock_exit();
 820 }
 821
 822 #ifdef KDTRACE_HOOKS
 823 void
 824 clocksource_cyc_set(const struct bintime *t)
 825 {
 826         struct bintime now;
 827         struct pcpu_state *state;
 828
 829         state = DPCPU_PTR(timerstate);
 830         if (periodic)
 831                 now = state->now;
 832         else
 833                 binuptime(&now);
 834
 835         CTR4(KTR_SPARE2, "set_cyc at %d:  now  %d.%08x%08x",
 836             curcpu, now.sec, (u_int)(now.frac >> 32),
 837                              (u_int)(now.frac & 0xffffffff));
 838         CTR4(KTR_SPARE2, "set_cyc at %d:  t  %d.%08x%08x",
 839             curcpu, t->sec, (u_int)(t->frac >> 32),
 840                              (u_int)(t->frac & 0xffffffff));
 841
 842         ET_HW_LOCK(state);
 843         if (bintime_cmp(t, &state->nextcyc, ==)) {
 844                 ET_HW_UNLOCK(state);
 845                 return;
 846         }
 847         state->nextcyc = *t;
 848         if (bintime_cmp(&state->nextcyc, &state->nextevent, >=)) {
 849                 ET_HW_UNLOCK(state);
 850                 return;
 851         }
 852         state->nextevent = state->nextcyc;
 853         if (!periodic)
 854                 loadtimer(&now, 0);
 855         ET_HW_UNLOCK(state);
 856 }
 857 #endif
 858
 859 #ifdef SMP
 860 static void
 861 cpu_new_callout(int cpu, int ticks)
 862 {
 863         struct bintime tmp;
 864         struct pcpu_state *state;
 865
 866         CTR3(KTR_SPARE2, "new co at %d:    on %d in %d",
 867             curcpu, cpu, ticks);
 868         state = DPCPU_ID_PTR(cpu, timerstate);
 869         ET_HW_LOCK(state);
 870         if (state->idle == 0 || busy) {
 871                 ET_HW_UNLOCK(state);
 872                 return;
 873         }
 874         /*
 875          * If timer is periodic - just update next event time for target CPU.
 876          * If timer is global - there is chance it is already programmed.
 877          */
 878         if (periodic || (timer->et_flags & ET_FLAGS_PERCPU) == 0) {
 879                 tmp = hardperiod;
 880                 bintime_mul(&tmp, ticks - 1);
 881                 bintime_add(&tmp, &state->nexthard);
 882                 if (bintime_cmp(&tmp, &state->nextevent, <))
 883                         state->nextevent = tmp;
 884                 if (periodic ||
 885                     bintime_cmp(&state->nextevent, &nexttick, >=)) {
 886                         ET_HW_UNLOCK(state);
 887                         return;
 888                 }
 889         }
 890         /*
 891          * Otherwise we have to wake that CPU up, as we can't get present
 892          * bintime to reprogram global timer from here. If timer is per-CPU,
 893          * we by definition can't do it from here.
 894          */
 895         ET_HW_UNLOCK(state);
 896         if (timer->et_flags & ET_FLAGS_PERCPU) {
 897                 state->handle = 1;
 898                 ipi_cpu(cpu, IPI_HARDCLOCK);
 899         } else {
 900                 if (!cpu_idle_wakeup(cpu))
 901                         ipi_cpu(cpu, IPI_AST);
 902         }
 903 }
 904 #endif
 905
 906 /*
 907  * Report or change the active event timers hardware.
 908  */
 909 static int
 910 sysctl_kern_eventtimer_timer(SYSCTL_HANDLER_ARGS)
 911 {
 912         char buf[32];
 913         struct eventtimer *et;
 914         int error;
 915
 916         ET_LOCK();
 917         et = timer;
 918         snprintf(buf, sizeof(buf), "%s", et->et_name);
 919         ET_UNLOCK();
 920         error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
 921         ET_LOCK();
 922         et = timer;
 923         if (error != 0 || req->newptr == NULL ||
 924             strcasecmp(buf, et->et_name) == 0) {
 925                 ET_UNLOCK();
 926                 return (error);
 927         }
 928         et = et_find(buf, 0, 0);
 929         if (et == NULL) {
 930                 ET_UNLOCK();
 931                 return (ENOENT);
 932         }
 933         configtimer(0);
 934         et_free(timer);
 935         if (et->et_flags & ET_FLAGS_C3STOP)
 936                 cpu_disable_deep_sleep++;
 937         if (timer->et_flags & ET_FLAGS_C3STOP)
 938                 cpu_disable_deep_sleep--;
 939         periodic = want_periodic;
 940         timer = et;
 941         et_init(timer, timercb, NULL, NULL);
 942         configtimer(1);
 943         ET_UNLOCK();
 944         return (error);
 945 }
 946 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, timer,
 947     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE,
 948     0, 0, sysctl_kern_eventtimer_timer, "A", "Chosen event timer");
 949
 950 /*
 951  * Report or change the active event timer periodicity.
 952  */
 953 static int
 954 sysctl_kern_eventtimer_periodic(SYSCTL_HANDLER_ARGS)
 955 {
 956         int error, val;
 957
 958         val = periodic;
 959         error = sysctl_handle_int(oidp, &val, 0, req);
 960         if (error != 0 || req->newptr == NULL)
 961                 return (error);
 962         ET_LOCK();
 963         configtimer(0);
 964         periodic = want_periodic = val;
 965         configtimer(1);
 966         ET_UNLOCK();
 967         return (error);
 968 }
 969 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, periodic,
 970     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
 971     0, 0, sysctl_kern_eventtimer_periodic, "I", "Enable event timer periodic mode");