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_disable_c2_sleep = 0; /* Timer dies in C2. */
58 int cpu_disable_c3_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 hardclock() 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
hardclockintr(void)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
handleevents(sbintime_t now,int fake)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 || now >= state->nextcall) {
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
getnextcpuevent(int idle)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
getnextevent(void)266 getnextevent(void)
267 {
268 struct pcpu_state *state;
269 sbintime_t event;
270 #ifdef SMP
271 int cpu;
272 #endif
273 #ifdef KTR
274 int c;
275
276 c = -1;
277 #endif
278 state = DPCPU_PTR(timerstate);
279 event = state->nextevent;
280 #ifdef SMP
281 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0) {
282 CPU_FOREACH(cpu) {
283 state = DPCPU_ID_PTR(cpu, timerstate);
284 if (event > state->nextevent) {
285 event = state->nextevent;
286 #ifdef KTR
287 c = cpu;
288 #endif
289 }
290 }
291 }
292 #endif
293 CTR4(KTR_SPARE2, "next at %d: next %d.%08x by %d",
294 curcpu, (int)(event >> 32), (u_int)(event & 0xffffffff), c);
295 return (event);
296 }
297
298 /* Hardware timer callback function. */
299 static void
timercb(struct eventtimer * et,void * arg)300 timercb(struct eventtimer *et, void *arg)
301 {
302 sbintime_t now;
303 sbintime_t *next;
304 struct pcpu_state *state;
305 #ifdef SMP
306 int cpu, bcast;
307 #endif
308
309 /* Do not touch anything if somebody reconfiguring timers. */
310 if (busy)
311 return;
312 /* Update present and next tick times. */
313 state = DPCPU_PTR(timerstate);
314 if (et->et_flags & ET_FLAGS_PERCPU) {
315 next = &state->nexttick;
316 } else
317 next = &nexttick;
318 now = sbinuptime();
319 if (periodic)
320 *next = now + timerperiod;
321 else
322 *next = -1; /* Next tick is not scheduled yet. */
323 state->now = now;
324 CTR3(KTR_SPARE2, "intr at %d: now %d.%08x",
325 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
326
327 #ifdef SMP
328 #ifdef EARLY_AP_STARTUP
329 MPASS(mp_ncpus == 1 || smp_started);
330 #endif
331 /* Prepare broadcasting to other CPUs for non-per-CPU timers. */
332 bcast = 0;
333 #ifdef EARLY_AP_STARTUP
334 if ((et->et_flags & ET_FLAGS_PERCPU) == 0) {
335 #else
336 if ((et->et_flags & ET_FLAGS_PERCPU) == 0 && smp_started) {
337 #endif
338 CPU_FOREACH(cpu) {
339 state = DPCPU_ID_PTR(cpu, timerstate);
340 ET_HW_LOCK(state);
341 state->now = now;
342 if (now >= state->nextevent) {
343 state->nextevent += SBT_1S;
344 if (curcpu != cpu) {
345 state->ipi = 1;
346 bcast = 1;
347 }
348 }
349 ET_HW_UNLOCK(state);
350 }
351 }
352 #endif
353
354 /* Handle events for this time on this CPU. */
355 handleevents(now, 0);
356
357 #ifdef SMP
358 /* Broadcast interrupt to other CPUs for non-per-CPU timers. */
359 if (bcast) {
360 CPU_FOREACH(cpu) {
361 if (curcpu == cpu)
362 continue;
363 state = DPCPU_ID_PTR(cpu, timerstate);
364 if (state->ipi) {
365 state->ipi = 0;
366 ipi_cpu(cpu, IPI_HARDCLOCK);
367 }
368 }
369 }
370 #endif
371 }
372
373 /*
374 * Load new value into hardware timer.
375 */
376 static void
377 loadtimer(sbintime_t now, int start)
378 {
379 struct pcpu_state *state;
380 sbintime_t new;
381 sbintime_t *next;
382 uint64_t tmp;
383 int eq;
384
385 if (timer->et_flags & ET_FLAGS_PERCPU) {
386 state = DPCPU_PTR(timerstate);
387 next = &state->nexttick;
388 } else
389 next = &nexttick;
390 if (periodic) {
391 if (start) {
392 /*
393 * Try to start all periodic timers aligned
394 * to period to make events synchronous.
395 */
396 tmp = now % timerperiod;
397 new = timerperiod - tmp;
398 if (new < tmp) /* Left less then passed. */
399 new += timerperiod;
400 CTR5(KTR_SPARE2, "load p at %d: now %d.%08x first in %d.%08x",
401 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff),
402 (int)(new >> 32), (u_int)(new & 0xffffffff));
403 *next = new + now;
404 et_start(timer, new, timerperiod);
405 }
406 } else {
407 new = getnextevent();
408 eq = (new == *next);
409 CTR4(KTR_SPARE2, "load at %d: next %d.%08x eq %d",
410 curcpu, (int)(new >> 32), (u_int)(new & 0xffffffff), eq);
411 if (!eq) {
412 *next = new;
413 et_start(timer, new - now, 0);
414 }
415 }
416 }
417
418 /*
419 * Prepare event timer parameters after configuration changes.
420 */
421 static void
422 setuptimer(void)
423 {
424 int freq;
425
426 if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0)
427 periodic = 0;
428 else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0)
429 periodic = 1;
430 singlemul = MIN(MAX(singlemul, 1), 20);
431 freq = hz * singlemul;
432 while (freq < (profiling ? profhz : stathz))
433 freq += hz;
434 freq = round_freq(timer, freq);
435 timerperiod = SBT_1S / freq;
436 }
437
438 /*
439 * Reconfigure specified per-CPU timer on other CPU. Called from IPI handler.
440 */
441 static int
442 doconfigtimer(void)
443 {
444 sbintime_t now;
445 struct pcpu_state *state;
446
447 state = DPCPU_PTR(timerstate);
448 switch (atomic_load_acq_int(&state->action)) {
449 case 1:
450 now = sbinuptime();
451 ET_HW_LOCK(state);
452 loadtimer(now, 1);
453 ET_HW_UNLOCK(state);
454 state->handle = 0;
455 atomic_store_rel_int(&state->action, 0);
456 return (1);
457 case 2:
458 ET_HW_LOCK(state);
459 et_stop(timer);
460 ET_HW_UNLOCK(state);
461 state->handle = 0;
462 atomic_store_rel_int(&state->action, 0);
463 return (1);
464 }
465 if (atomic_readandclear_int(&state->handle) && !busy) {
466 now = sbinuptime();
467 handleevents(now, 0);
468 return (1);
469 }
470 return (0);
471 }
472
473 /*
474 * Reconfigure specified timer.
475 * For per-CPU timers use IPI to make other CPUs to reconfigure.
476 */
477 static void
478 configtimer(int start)
479 {
480 sbintime_t now, next;
481 struct pcpu_state *state;
482 int cpu;
483
484 if (start) {
485 setuptimer();
486 now = sbinuptime();
487 } else
488 now = 0;
489 critical_enter();
490 ET_HW_LOCK(DPCPU_PTR(timerstate));
491 if (start) {
492 /* Initialize time machine parameters. */
493 next = now + timerperiod;
494 if (periodic)
495 nexttick = next;
496 else
497 nexttick = -1;
498 #ifdef EARLY_AP_STARTUP
499 MPASS(mp_ncpus == 1 || smp_started);
500 #endif
501 CPU_FOREACH(cpu) {
502 state = DPCPU_ID_PTR(cpu, timerstate);
503 state->now = now;
504 #ifndef EARLY_AP_STARTUP
505 if (!smp_started && cpu != CPU_FIRST())
506 state->nextevent = SBT_MAX;
507 else
508 #endif
509 state->nextevent = next;
510 if (periodic)
511 state->nexttick = next;
512 else
513 state->nexttick = -1;
514 state->nexthard = next;
515 state->nextstat = next;
516 state->nextprof = next;
517 state->nextcall = next;
518 state->nextcallopt = next;
519 hardclock_sync(cpu);
520 }
521 busy = 0;
522 /* Start global timer or per-CPU timer of this CPU. */
523 loadtimer(now, 1);
524 } else {
525 busy = 1;
526 /* Stop global timer or per-CPU timer of this CPU. */
527 et_stop(timer);
528 }
529 ET_HW_UNLOCK(DPCPU_PTR(timerstate));
530 #ifdef SMP
531 #ifdef EARLY_AP_STARTUP
532 /* If timer is global we are done. */
533 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0) {
534 #else
535 /* If timer is global or there is no other CPUs yet - we are done. */
536 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || !smp_started) {
537 #endif
538 critical_exit();
539 return;
540 }
541 /* Set reconfigure flags for other CPUs. */
542 CPU_FOREACH(cpu) {
543 state = DPCPU_ID_PTR(cpu, timerstate);
544 atomic_store_rel_int(&state->action,
545 (cpu == curcpu) ? 0 : ( start ? 1 : 2));
546 }
547 /* Broadcast reconfigure IPI. */
548 ipi_all_but_self(IPI_HARDCLOCK);
549 /* Wait for reconfiguration completed. */
550 restart:
551 cpu_spinwait();
552 CPU_FOREACH(cpu) {
553 if (cpu == curcpu)
554 continue;
555 state = DPCPU_ID_PTR(cpu, timerstate);
556 if (atomic_load_acq_int(&state->action))
557 goto restart;
558 }
559 #endif
560 critical_exit();
561 }
562
563 /*
564 * Calculate nearest frequency supported by hardware timer.
565 */
566 static int
567 round_freq(struct eventtimer *et, int freq)
568 {
569 uint64_t div;
570
571 if (et->et_frequency != 0) {
572 div = lmax((et->et_frequency + freq / 2) / freq, 1);
573 if (et->et_flags & ET_FLAGS_POW2DIV)
574 div = 1 << (flsl(div + div / 2) - 1);
575 freq = (et->et_frequency + div / 2) / div;
576 }
577 if (et->et_min_period > SBT_1S)
578 panic("Event timer \"%s\" doesn't support sub-second periods!",
579 et->et_name);
580 else if (et->et_min_period != 0)
581 freq = min(freq, SBT2FREQ(et->et_min_period));
582 if (et->et_max_period < SBT_1S && et->et_max_period != 0)
583 freq = max(freq, SBT2FREQ(et->et_max_period));
584 return (freq);
585 }
586
587 /*
588 * Configure and start event timers (BSP part).
589 */
590 void
591 cpu_initclocks_bsp(void)
592 {
593 struct pcpu_state *state;
594 int base, div, cpu;
595
596 mtx_init(&et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN);
597 CPU_FOREACH(cpu) {
598 state = DPCPU_ID_PTR(cpu, timerstate);
599 mtx_init(&state->et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN);
600 state->nextcall = SBT_MAX;
601 state->nextcallopt = SBT_MAX;
602 }
603 periodic = want_periodic;
604 /* Grab requested timer or the best of present. */
605 if (timername[0])
606 timer = et_find(timername, 0, 0);
607 if (timer == NULL && periodic) {
608 timer = et_find(NULL,
609 ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC);
610 }
611 if (timer == NULL) {
612 timer = et_find(NULL,
613 ET_FLAGS_ONESHOT, ET_FLAGS_ONESHOT);
614 }
615 if (timer == NULL && !periodic) {
616 timer = et_find(NULL,
617 ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC);
618 }
619 if (timer == NULL)
620 panic("No usable event timer found!");
621 et_init(timer, timercb, NULL, NULL);
622
623 /* Adapt to timer capabilities. */
624 if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0)
625 periodic = 0;
626 else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0)
627 periodic = 1;
628 if (timer->et_flags & ET_FLAGS_C3STOP)
629 cpu_disable_c3_sleep++;
630
631 /*
632 * We honor the requested 'hz' value.
633 * We want to run stathz in the neighborhood of 128hz.
634 * We would like profhz to run as often as possible.
635 */
636 if (singlemul <= 0 || singlemul > 20) {
637 if (hz >= 1500 || (hz % 128) == 0)
638 singlemul = 1;
639 else if (hz >= 750)
640 singlemul = 2;
641 else
642 singlemul = 4;
643 }
644 if (periodic) {
645 base = round_freq(timer, hz * singlemul);
646 singlemul = max((base + hz / 2) / hz, 1);
647 hz = (base + singlemul / 2) / singlemul;
648 if (base <= 128)
649 stathz = base;
650 else {
651 div = base / 128;
652 if (div >= singlemul && (div % singlemul) == 0)
653 div++;
654 stathz = base / div;
655 }
656 profhz = stathz;
657 while ((profhz + stathz) <= 128 * 64)
658 profhz += stathz;
659 profhz = round_freq(timer, profhz);
660 } else {
661 hz = round_freq(timer, hz);
662 stathz = round_freq(timer, 127);
663 profhz = round_freq(timer, stathz * 64);
664 }
665 tick = 1000000 / hz;
666 tick_sbt = SBT_1S / hz;
667 tick_bt = sbttobt(tick_sbt);
668 statperiod = SBT_1S / stathz;
669 profperiod = SBT_1S / profhz;
670 ET_LOCK();
671 configtimer(1);
672 ET_UNLOCK();
673 }
674
675 /*
676 * Start per-CPU event timers on APs.
677 */
678 void
679 cpu_initclocks_ap(void)
680 {
681 sbintime_t now;
682 struct pcpu_state *state;
683 struct thread *td;
684
685 state = DPCPU_PTR(timerstate);
686 now = sbinuptime();
687 ET_HW_LOCK(state);
688 state->now = now;
689 hardclock_sync(curcpu);
690 spinlock_enter();
691 ET_HW_UNLOCK(state);
692 td = curthread;
693 td->td_intr_nesting_level++;
694 handleevents(state->now, 2);
695 td->td_intr_nesting_level--;
696 spinlock_exit();
697 }
698
699 void
700 suspendclock(void)
701 {
702 ET_LOCK();
703 configtimer(0);
704 ET_UNLOCK();
705 }
706
707 void
708 resumeclock(void)
709 {
710 ET_LOCK();
711 configtimer(1);
712 ET_UNLOCK();
713 }
714
715 /*
716 * Switch to profiling clock rates.
717 */
718 void
719 cpu_startprofclock(void)
720 {
721
722 ET_LOCK();
723 if (profiling == 0) {
724 if (periodic) {
725 configtimer(0);
726 profiling = 1;
727 configtimer(1);
728 } else
729 profiling = 1;
730 } else
731 profiling++;
732 ET_UNLOCK();
733 }
734
735 /*
736 * Switch to regular clock rates.
737 */
738 void
739 cpu_stopprofclock(void)
740 {
741
742 ET_LOCK();
743 if (profiling == 1) {
744 if (periodic) {
745 configtimer(0);
746 profiling = 0;
747 configtimer(1);
748 } else
749 profiling = 0;
750 } else
751 profiling--;
752 ET_UNLOCK();
753 }
754
755 /*
756 * Switch to idle mode (all ticks handled).
757 */
758 sbintime_t
759 cpu_idleclock(void)
760 {
761 sbintime_t now, t;
762 struct pcpu_state *state;
763
764 if (idletick || busy ||
765 (periodic && (timer->et_flags & ET_FLAGS_PERCPU))
766 #ifdef DEVICE_POLLING
767 || curcpu == CPU_FIRST()
768 #endif
769 )
770 return (-1);
771 state = DPCPU_PTR(timerstate);
772 if (periodic)
773 now = state->now;
774 else
775 now = sbinuptime();
776 CTR3(KTR_SPARE2, "idle at %d: now %d.%08x",
777 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
778 t = getnextcpuevent(1);
779 ET_HW_LOCK(state);
780 state->idle = 1;
781 state->nextevent = t;
782 if (!periodic)
783 loadtimer(now, 0);
784 ET_HW_UNLOCK(state);
785 return (MAX(t - now, 0));
786 }
787
788 /*
789 * Switch to active mode (skip empty ticks).
790 */
791 void
792 cpu_activeclock(void)
793 {
794 sbintime_t now;
795 struct pcpu_state *state;
796 struct thread *td;
797
798 state = DPCPU_PTR(timerstate);
799 if (state->idle == 0 || busy)
800 return;
801 if (periodic)
802 now = state->now;
803 else
804 now = sbinuptime();
805 CTR3(KTR_SPARE2, "active at %d: now %d.%08x",
806 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
807 spinlock_enter();
808 td = curthread;
809 td->td_intr_nesting_level++;
810 handleevents(now, 1);
811 td->td_intr_nesting_level--;
812 spinlock_exit();
813 }
814
815 /*
816 * Change the frequency of the given timer. This changes et->et_frequency and
817 * if et is the active timer it reconfigures the timer on all CPUs. This is
818 * intended to be a private interface for the use of et_change_frequency() only.
819 */
820 void
821 cpu_et_frequency(struct eventtimer *et, uint64_t newfreq)
822 {
823
824 ET_LOCK();
825 if (et == timer) {
826 configtimer(0);
827 et->et_frequency = newfreq;
828 configtimer(1);
829 } else
830 et->et_frequency = newfreq;
831 ET_UNLOCK();
832 }
833
834 void
835 cpu_new_callout(int cpu, sbintime_t bt, sbintime_t bt_opt)
836 {
837 struct pcpu_state *state;
838
839 /* Do not touch anything if somebody reconfiguring timers. */
840 if (busy)
841 return;
842 CTR6(KTR_SPARE2, "new co at %d: on %d at %d.%08x - %d.%08x",
843 curcpu, cpu, (int)(bt_opt >> 32), (u_int)(bt_opt & 0xffffffff),
844 (int)(bt >> 32), (u_int)(bt & 0xffffffff));
845 state = DPCPU_ID_PTR(cpu, timerstate);
846 ET_HW_LOCK(state);
847
848 /*
849 * If there is callout time already set earlier -- do nothing.
850 * This check may appear redundant because we check already in
851 * callout_process() but this double check guarantees we're safe
852 * with respect to race conditions between interrupts execution
853 * and scheduling.
854 */
855 state->nextcallopt = bt_opt;
856 if (bt >= state->nextcall)
857 goto done;
858 state->nextcall = bt;
859 /* If there is some other event set earlier -- do nothing. */
860 if (bt >= state->nextevent)
861 goto done;
862 state->nextevent = bt;
863 /* If timer is periodic -- there is nothing to reprogram. */
864 if (periodic)
865 goto done;
866 /* If timer is global or of the current CPU -- reprogram it. */
867 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || cpu == curcpu) {
868 loadtimer(sbinuptime(), 0);
869 done:
870 ET_HW_UNLOCK(state);
871 return;
872 }
873 /* Otherwise make other CPU to reprogram it. */
874 state->handle = 1;
875 ET_HW_UNLOCK(state);
876 #ifdef SMP
877 ipi_cpu(cpu, IPI_HARDCLOCK);
878 #endif
879 }
880
881 /*
882 * Report or change the active event timers hardware.
883 */
884 static int
885 sysctl_kern_eventtimer_timer(SYSCTL_HANDLER_ARGS)
886 {
887 char buf[32];
888 struct eventtimer *et;
889 int error;
890
891 ET_LOCK();
892 et = timer;
893 snprintf(buf, sizeof(buf), "%s", et->et_name);
894 ET_UNLOCK();
895 error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
896 ET_LOCK();
897 et = timer;
898 if (error != 0 || req->newptr == NULL ||
899 strcasecmp(buf, et->et_name) == 0) {
900 ET_UNLOCK();
901 return (error);
902 }
903 et = et_find(buf, 0, 0);
904 if (et == NULL) {
905 ET_UNLOCK();
906 return (ENOENT);
907 }
908 configtimer(0);
909 et_free(timer);
910 if (et->et_flags & ET_FLAGS_C3STOP)
911 cpu_disable_c3_sleep++;
912 if (timer->et_flags & ET_FLAGS_C3STOP)
913 cpu_disable_c3_sleep--;
914 periodic = want_periodic;
915 timer = et;
916 et_init(timer, timercb, NULL, NULL);
917 configtimer(1);
918 ET_UNLOCK();
919 return (error);
920 }
921 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, timer,
922 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE,
923 0, 0, sysctl_kern_eventtimer_timer, "A", "Chosen event timer");
924
925 /*
926 * Report or change the active event timer periodicity.
927 */
928 static int
929 sysctl_kern_eventtimer_periodic(SYSCTL_HANDLER_ARGS)
930 {
931 int error, val;
932
933 val = periodic;
934 error = sysctl_handle_int(oidp, &val, 0, req);
935 if (error != 0 || req->newptr == NULL)
936 return (error);
937 ET_LOCK();
938 configtimer(0);
939 periodic = want_periodic = val;
940 configtimer(1);
941 ET_UNLOCK();
942 return (error);
943 }
944 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, periodic,
945 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
946 0, 0, sysctl_kern_eventtimer_periodic, "I", "Enable event timer periodic mode");
947
948 #include "opt_ddb.h"
949
950 #ifdef DDB
951 #include <ddb/ddb.h>
952
953 DB_SHOW_COMMAND(clocksource, db_show_clocksource)
954 {
955 struct pcpu_state *st;
956 int c;
957
958 CPU_FOREACH(c) {
959 st = DPCPU_ID_PTR(c, timerstate);
960 db_printf(
961 "CPU %2d: action %d handle %d ipi %d idle %d\n"
962 " now %#jx nevent %#jx (%jd)\n"
963 " ntick %#jx (%jd) nhard %#jx (%jd)\n"
964 " nstat %#jx (%jd) nprof %#jx (%jd)\n"
965 " ncall %#jx (%jd) ncallopt %#jx (%jd)\n",
966 c, st->action, st->handle, st->ipi, st->idle,
967 (uintmax_t)st->now,
968 (uintmax_t)st->nextevent,
969 (uintmax_t)(st->nextevent - st->now) / tick_sbt,
970 (uintmax_t)st->nexttick,
971 (uintmax_t)(st->nexttick - st->now) / tick_sbt,
972 (uintmax_t)st->nexthard,
973 (uintmax_t)(st->nexthard - st->now) / tick_sbt,
974 (uintmax_t)st->nextstat,
975 (uintmax_t)(st->nextstat - st->now) / tick_sbt,
976 (uintmax_t)st->nextprof,
977 (uintmax_t)(st->nextprof - st->now) / tick_sbt,
978 (uintmax_t)st->nextcall,
979 (uintmax_t)(st->nextcall - st->now) / tick_sbt,
980 (uintmax_t)st->nextcallopt,
981 (uintmax_t)(st->nextcallopt - st->now) / tick_sbt);
982 }
983 }
984
985 #endif
986