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 #include "opt_kdtrace.h"
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/bus.h>
40 #include <sys/limits.h>
41 #include <sys/lock.h>
42 #include <sys/kdb.h>
43 #include <sys/ktr.h>
44 #include <sys/mutex.h>
45 #include <sys/proc.h>
46 #include <sys/kernel.h>
47 #include <sys/sched.h>
48 #include <sys/smp.h>
49 #include <sys/sysctl.h>
50 #include <sys/timeet.h>
51 #include <sys/timetc.h>
52
53 #include <machine/atomic.h>
54 #include <machine/clock.h>
55 #include <machine/cpu.h>
56 #include <machine/smp.h>
57
58 int cpu_deepest_sleep = 0; /* Deepest Cx state available. */
59 int cpu_disable_c2_sleep = 0; /* Timer dies in C2. */
60 int cpu_disable_c3_sleep = 0; /* Timer dies in C3. */
61
62 static void setuptimer(void);
63 static void loadtimer(sbintime_t now, int first);
64 static int doconfigtimer(void);
65 static void configtimer(int start);
66 static int round_freq(struct eventtimer *et, int freq);
67
68 static sbintime_t getnextcpuevent(int idle);
69 static sbintime_t getnextevent(void);
70 static int handleevents(sbintime_t now, int fake);
71
72 static struct mtx et_hw_mtx;
73
74 #define ET_HW_LOCK(state) \
75 { \
76 if (timer->et_flags & ET_FLAGS_PERCPU) \
77 mtx_lock_spin(&(state)->et_hw_mtx); \
78 else \
79 mtx_lock_spin(&et_hw_mtx); \
80 }
81
82 #define ET_HW_UNLOCK(state) \
83 { \
84 if (timer->et_flags & ET_FLAGS_PERCPU) \
85 mtx_unlock_spin(&(state)->et_hw_mtx); \
86 else \
87 mtx_unlock_spin(&et_hw_mtx); \
88 }
89
90 static struct eventtimer *timer = NULL;
91 static sbintime_t timerperiod; /* Timer period for periodic mode. */
92 static sbintime_t statperiod; /* statclock() events period. */
93 static sbintime_t profperiod; /* profclock() events period. */
94 static sbintime_t nexttick; /* Next global timer tick time. */
95 static u_int busy = 1; /* Reconfiguration is in progress. */
96 static int profiling = 0; /* Profiling events enabled. */
97
98 static char timername[32]; /* Wanted timer. */
99 TUNABLE_STR("kern.eventtimer.timer", timername, sizeof(timername));
100
101 static int singlemul = 0; /* Multiplier for periodic mode. */
102 TUNABLE_INT("kern.eventtimer.singlemul", &singlemul);
103 SYSCTL_INT(_kern_eventtimer, OID_AUTO, singlemul, CTLFLAG_RW, &singlemul,
104 0, "Multiplier for periodic mode");
105
106 static u_int idletick = 0; /* Run periodic events when idle. */
107 TUNABLE_INT("kern.eventtimer.idletick", &idletick);
108 SYSCTL_UINT(_kern_eventtimer, OID_AUTO, idletick, CTLFLAG_RW, &idletick,
109 0, "Run periodic events when idle");
110
111 static int periodic = 0; /* Periodic or one-shot mode. */
112 static int want_periodic = 0; /* What mode to prefer. */
113 TUNABLE_INT("kern.eventtimer.periodic", &want_periodic);
114
115 struct pcpu_state {
116 struct mtx et_hw_mtx; /* Per-CPU timer mutex. */
117 u_int action; /* Reconfiguration requests. */
118 u_int handle; /* Immediate handle resuests. */
119 sbintime_t now; /* Last tick time. */
120 sbintime_t nextevent; /* Next scheduled event on this CPU. */
121 sbintime_t nexttick; /* Next timer tick time. */
122 sbintime_t nexthard; /* Next hardlock() event. */
123 sbintime_t nextstat; /* Next statclock() event. */
124 sbintime_t nextprof; /* Next profclock() event. */
125 sbintime_t nextcall; /* Next callout event. */
126 sbintime_t nextcallopt; /* Next optional callout event. */
127 int ipi; /* This CPU needs IPI. */
128 int idle; /* This CPU is in idle mode. */
129 };
130
131 static DPCPU_DEFINE(struct pcpu_state, timerstate);
132 DPCPU_DEFINE(sbintime_t, hardclocktime);
133
134 /*
135 * Timer broadcast IPI handler.
136 */
137 int
hardclockintr(void)138 hardclockintr(void)
139 {
140 sbintime_t now;
141 struct pcpu_state *state;
142 int done;
143
144 if (doconfigtimer() || busy)
145 return (FILTER_HANDLED);
146 state = DPCPU_PTR(timerstate);
147 now = state->now;
148 CTR3(KTR_SPARE2, "ipi at %d: now %d.%08x",
149 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
150 done = handleevents(now, 0);
151 return (done ? FILTER_HANDLED : FILTER_STRAY);
152 }
153
154 /*
155 * Handle all events for specified time on this CPU
156 */
157 static int
handleevents(sbintime_t now,int fake)158 handleevents(sbintime_t now, int fake)
159 {
160 sbintime_t t, *hct;
161 struct trapframe *frame;
162 struct pcpu_state *state;
163 int usermode;
164 int done, runs;
165
166 CTR3(KTR_SPARE2, "handle at %d: now %d.%08x",
167 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
168 done = 0;
169 if (fake) {
170 frame = NULL;
171 usermode = 0;
172 } else {
173 frame = curthread->td_intr_frame;
174 usermode = TRAPF_USERMODE(frame);
175 }
176
177 state = DPCPU_PTR(timerstate);
178
179 runs = 0;
180 while (now >= state->nexthard) {
181 state->nexthard += tick_sbt;
182 runs++;
183 }
184 if (runs) {
185 hct = DPCPU_PTR(hardclocktime);
186 *hct = state->nexthard - tick_sbt;
187 if (fake < 2) {
188 hardclock_cnt(runs, usermode);
189 done = 1;
190 }
191 }
192 runs = 0;
193 while (now >= state->nextstat) {
194 state->nextstat += statperiod;
195 runs++;
196 }
197 if (runs && fake < 2) {
198 statclock_cnt(runs, usermode);
199 done = 1;
200 }
201 if (profiling) {
202 runs = 0;
203 while (now >= state->nextprof) {
204 state->nextprof += profperiod;
205 runs++;
206 }
207 if (runs && !fake) {
208 profclock_cnt(runs, usermode, TRAPF_PC(frame));
209 done = 1;
210 }
211 } else
212 state->nextprof = state->nextstat;
213 if (now >= state->nextcallopt) {
214 state->nextcall = state->nextcallopt = INT64_MAX;
215 callout_process(now);
216 }
217
218 t = getnextcpuevent(0);
219 ET_HW_LOCK(state);
220 if (!busy) {
221 state->idle = 0;
222 state->nextevent = t;
223 loadtimer(now, (fake == 2) &&
224 (timer->et_flags & ET_FLAGS_PERCPU));
225 }
226 ET_HW_UNLOCK(state);
227 return (done);
228 }
229
230 /*
231 * Schedule binuptime of the next event on current CPU.
232 */
233 static sbintime_t
getnextcpuevent(int idle)234 getnextcpuevent(int idle)
235 {
236 sbintime_t event;
237 struct pcpu_state *state;
238 u_int hardfreq;
239
240 state = DPCPU_PTR(timerstate);
241 /* Handle hardclock() events, skipping some if CPU is idle. */
242 event = state->nexthard;
243 if (idle) {
244 hardfreq = (u_int)hz / 2;
245 if (tc_min_ticktock_freq > 2
246 #ifdef SMP
247 && curcpu == CPU_FIRST()
248 #endif
249 )
250 hardfreq = hz / tc_min_ticktock_freq;
251 if (hardfreq > 1)
252 event += tick_sbt * (hardfreq - 1);
253 }
254 /* Handle callout events. */
255 if (event > state->nextcall)
256 event = state->nextcall;
257 if (!idle) { /* If CPU is active - handle other types of events. */
258 if (event > state->nextstat)
259 event = state->nextstat;
260 if (profiling && event > state->nextprof)
261 event = state->nextprof;
262 }
263 return (event);
264 }
265
266 /*
267 * Schedule binuptime of the next event on all CPUs.
268 */
269 static sbintime_t
getnextevent(void)270 getnextevent(void)
271 {
272 struct pcpu_state *state;
273 sbintime_t event;
274 #ifdef SMP
275 int cpu;
276 #endif
277 int c;
278
279 state = DPCPU_PTR(timerstate);
280 event = state->nextevent;
281 c = -1;
282 #ifdef SMP
283 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0) {
284 CPU_FOREACH(cpu) {
285 state = DPCPU_ID_PTR(cpu, timerstate);
286 if (event > state->nextevent) {
287 event = state->nextevent;
288 c = cpu;
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 /* Prepare broadcasting to other CPUs for non-per-CPU timers. */
329 bcast = 0;
330 if ((et->et_flags & ET_FLAGS_PERCPU) == 0 && smp_started) {
331 CPU_FOREACH(cpu) {
332 state = DPCPU_ID_PTR(cpu, timerstate);
333 ET_HW_LOCK(state);
334 state->now = now;
335 if (now >= state->nextevent) {
336 state->nextevent += SBT_1S;
337 if (curcpu != cpu) {
338 state->ipi = 1;
339 bcast = 1;
340 }
341 }
342 ET_HW_UNLOCK(state);
343 }
344 }
345 #endif
346
347 /* Handle events for this time on this CPU. */
348 handleevents(now, 0);
349
350 #ifdef SMP
351 /* Broadcast interrupt to other CPUs for non-per-CPU timers. */
352 if (bcast) {
353 CPU_FOREACH(cpu) {
354 if (curcpu == cpu)
355 continue;
356 state = DPCPU_ID_PTR(cpu, timerstate);
357 if (state->ipi) {
358 state->ipi = 0;
359 ipi_cpu(cpu, IPI_HARDCLOCK);
360 }
361 }
362 }
363 #endif
364 }
365
366 /*
367 * Load new value into hardware timer.
368 */
369 static void
loadtimer(sbintime_t now,int start)370 loadtimer(sbintime_t now, int start)
371 {
372 struct pcpu_state *state;
373 sbintime_t new;
374 sbintime_t *next;
375 uint64_t tmp;
376 int eq;
377
378 if (timer->et_flags & ET_FLAGS_PERCPU) {
379 state = DPCPU_PTR(timerstate);
380 next = &state->nexttick;
381 } else
382 next = &nexttick;
383 if (periodic) {
384 if (start) {
385 /*
386 * Try to start all periodic timers aligned
387 * to period to make events synchronous.
388 */
389 tmp = now % timerperiod;
390 new = timerperiod - tmp;
391 if (new < tmp) /* Left less then passed. */
392 new += timerperiod;
393 CTR5(KTR_SPARE2, "load p at %d: now %d.%08x first in %d.%08x",
394 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff),
395 (int)(new >> 32), (u_int)(new & 0xffffffff));
396 *next = new + now;
397 et_start(timer, new, timerperiod);
398 }
399 } else {
400 new = getnextevent();
401 eq = (new == *next);
402 CTR4(KTR_SPARE2, "load at %d: next %d.%08x eq %d",
403 curcpu, (int)(new >> 32), (u_int)(new & 0xffffffff), eq);
404 if (!eq) {
405 *next = new;
406 et_start(timer, new - now, 0);
407 }
408 }
409 }
410
411 /*
412 * Prepare event timer parameters after configuration changes.
413 */
414 static void
setuptimer(void)415 setuptimer(void)
416 {
417 int freq;
418
419 if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0)
420 periodic = 0;
421 else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0)
422 periodic = 1;
423 singlemul = MIN(MAX(singlemul, 1), 20);
424 freq = hz * singlemul;
425 while (freq < (profiling ? profhz : stathz))
426 freq += hz;
427 freq = round_freq(timer, freq);
428 timerperiod = SBT_1S / freq;
429 }
430
431 /*
432 * Reconfigure specified per-CPU timer on other CPU. Called from IPI handler.
433 */
434 static int
doconfigtimer(void)435 doconfigtimer(void)
436 {
437 sbintime_t now;
438 struct pcpu_state *state;
439
440 state = DPCPU_PTR(timerstate);
441 switch (atomic_load_acq_int(&state->action)) {
442 case 1:
443 now = sbinuptime();
444 ET_HW_LOCK(state);
445 loadtimer(now, 1);
446 ET_HW_UNLOCK(state);
447 state->handle = 0;
448 atomic_store_rel_int(&state->action, 0);
449 return (1);
450 case 2:
451 ET_HW_LOCK(state);
452 et_stop(timer);
453 ET_HW_UNLOCK(state);
454 state->handle = 0;
455 atomic_store_rel_int(&state->action, 0);
456 return (1);
457 }
458 if (atomic_readandclear_int(&state->handle) && !busy) {
459 now = sbinuptime();
460 handleevents(now, 0);
461 return (1);
462 }
463 return (0);
464 }
465
466 /*
467 * Reconfigure specified timer.
468 * For per-CPU timers use IPI to make other CPUs to reconfigure.
469 */
470 static void
configtimer(int start)471 configtimer(int start)
472 {
473 sbintime_t now, next;
474 struct pcpu_state *state;
475 int cpu;
476
477 if (start) {
478 setuptimer();
479 now = sbinuptime();
480 } else
481 now = 0;
482 critical_enter();
483 ET_HW_LOCK(DPCPU_PTR(timerstate));
484 if (start) {
485 /* Initialize time machine parameters. */
486 next = now + timerperiod;
487 if (periodic)
488 nexttick = next;
489 else
490 nexttick = -1;
491 CPU_FOREACH(cpu) {
492 state = DPCPU_ID_PTR(cpu, timerstate);
493 state->now = now;
494 if (!smp_started && cpu != CPU_FIRST())
495 state->nextevent = INT64_MAX;
496 else
497 state->nextevent = next;
498 if (periodic)
499 state->nexttick = next;
500 else
501 state->nexttick = -1;
502 state->nexthard = next;
503 state->nextstat = next;
504 state->nextprof = next;
505 state->nextcall = next;
506 state->nextcallopt = next;
507 hardclock_sync(cpu);
508 }
509 busy = 0;
510 /* Start global timer or per-CPU timer of this CPU. */
511 loadtimer(now, 1);
512 } else {
513 busy = 1;
514 /* Stop global timer or per-CPU timer of this CPU. */
515 et_stop(timer);
516 }
517 ET_HW_UNLOCK(DPCPU_PTR(timerstate));
518 #ifdef SMP
519 /* If timer is global or there is no other CPUs yet - we are done. */
520 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || !smp_started) {
521 critical_exit();
522 return;
523 }
524 /* Set reconfigure flags for other CPUs. */
525 CPU_FOREACH(cpu) {
526 state = DPCPU_ID_PTR(cpu, timerstate);
527 atomic_store_rel_int(&state->action,
528 (cpu == curcpu) ? 0 : ( start ? 1 : 2));
529 }
530 /* Broadcast reconfigure IPI. */
531 ipi_all_but_self(IPI_HARDCLOCK);
532 /* Wait for reconfiguration completed. */
533 restart:
534 cpu_spinwait();
535 CPU_FOREACH(cpu) {
536 if (cpu == curcpu)
537 continue;
538 state = DPCPU_ID_PTR(cpu, timerstate);
539 if (atomic_load_acq_int(&state->action))
540 goto restart;
541 }
542 #endif
543 critical_exit();
544 }
545
546 /*
547 * Calculate nearest frequency supported by hardware timer.
548 */
549 static int
round_freq(struct eventtimer * et,int freq)550 round_freq(struct eventtimer *et, int freq)
551 {
552 uint64_t div;
553
554 if (et->et_frequency != 0) {
555 div = lmax((et->et_frequency + freq / 2) / freq, 1);
556 if (et->et_flags & ET_FLAGS_POW2DIV)
557 div = 1 << (flsl(div + div / 2) - 1);
558 freq = (et->et_frequency + div / 2) / div;
559 }
560 if (et->et_min_period > SBT_1S)
561 panic("Event timer \"%s\" doesn't support sub-second periods!",
562 et->et_name);
563 else if (et->et_min_period != 0)
564 freq = min(freq, SBT2FREQ(et->et_min_period));
565 if (et->et_max_period < SBT_1S && et->et_max_period != 0)
566 freq = max(freq, SBT2FREQ(et->et_max_period));
567 return (freq);
568 }
569
570 /*
571 * Configure and start event timers (BSP part).
572 */
573 void
cpu_initclocks_bsp(void)574 cpu_initclocks_bsp(void)
575 {
576 struct pcpu_state *state;
577 int base, div, cpu;
578
579 mtx_init(&et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN);
580 CPU_FOREACH(cpu) {
581 state = DPCPU_ID_PTR(cpu, timerstate);
582 mtx_init(&state->et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN);
583 state->nextcall = INT64_MAX;
584 state->nextcallopt = INT64_MAX;
585 }
586 periodic = want_periodic;
587 /* Grab requested timer or the best of present. */
588 if (timername[0])
589 timer = et_find(timername, 0, 0);
590 if (timer == NULL && periodic) {
591 timer = et_find(NULL,
592 ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC);
593 }
594 if (timer == NULL) {
595 timer = et_find(NULL,
596 ET_FLAGS_ONESHOT, ET_FLAGS_ONESHOT);
597 }
598 if (timer == NULL && !periodic) {
599 timer = et_find(NULL,
600 ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC);
601 }
602 if (timer == NULL)
603 panic("No usable event timer found!");
604 et_init(timer, timercb, NULL, NULL);
605
606 /* Adapt to timer capabilities. */
607 if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0)
608 periodic = 0;
609 else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0)
610 periodic = 1;
611 if (timer->et_flags & ET_FLAGS_C3STOP)
612 cpu_disable_c3_sleep++;
613
614 /*
615 * We honor the requested 'hz' value.
616 * We want to run stathz in the neighborhood of 128hz.
617 * We would like profhz to run as often as possible.
618 */
619 if (singlemul <= 0 || singlemul > 20) {
620 if (hz >= 1500 || (hz % 128) == 0)
621 singlemul = 1;
622 else if (hz >= 750)
623 singlemul = 2;
624 else
625 singlemul = 4;
626 }
627 if (periodic) {
628 base = round_freq(timer, hz * singlemul);
629 singlemul = max((base + hz / 2) / hz, 1);
630 hz = (base + singlemul / 2) / singlemul;
631 if (base <= 128)
632 stathz = base;
633 else {
634 div = base / 128;
635 if (div >= singlemul && (div % singlemul) == 0)
636 div++;
637 stathz = base / div;
638 }
639 profhz = stathz;
640 while ((profhz + stathz) <= 128 * 64)
641 profhz += stathz;
642 profhz = round_freq(timer, profhz);
643 } else {
644 hz = round_freq(timer, hz);
645 stathz = round_freq(timer, 127);
646 profhz = round_freq(timer, stathz * 64);
647 }
648 tick = 1000000 / hz;
649 tick_sbt = SBT_1S / hz;
650 tick_bt = sbttobt(tick_sbt);
651 statperiod = SBT_1S / stathz;
652 profperiod = SBT_1S / profhz;
653 ET_LOCK();
654 configtimer(1);
655 ET_UNLOCK();
656 }
657
658 /*
659 * Start per-CPU event timers on APs.
660 */
661 void
cpu_initclocks_ap(void)662 cpu_initclocks_ap(void)
663 {
664 sbintime_t now;
665 struct pcpu_state *state;
666 struct thread *td;
667
668 state = DPCPU_PTR(timerstate);
669 now = sbinuptime();
670 ET_HW_LOCK(state);
671 state->now = now;
672 hardclock_sync(curcpu);
673 spinlock_enter();
674 ET_HW_UNLOCK(state);
675 td = curthread;
676 td->td_intr_nesting_level++;
677 handleevents(state->now, 2);
678 td->td_intr_nesting_level--;
679 spinlock_exit();
680 }
681
682 /*
683 * Switch to profiling clock rates.
684 */
685 void
cpu_startprofclock(void)686 cpu_startprofclock(void)
687 {
688
689 ET_LOCK();
690 if (profiling == 0) {
691 if (periodic) {
692 configtimer(0);
693 profiling = 1;
694 configtimer(1);
695 } else
696 profiling = 1;
697 } else
698 profiling++;
699 ET_UNLOCK();
700 }
701
702 /*
703 * Switch to regular clock rates.
704 */
705 void
cpu_stopprofclock(void)706 cpu_stopprofclock(void)
707 {
708
709 ET_LOCK();
710 if (profiling == 1) {
711 if (periodic) {
712 configtimer(0);
713 profiling = 0;
714 configtimer(1);
715 } else
716 profiling = 0;
717 } else
718 profiling--;
719 ET_UNLOCK();
720 }
721
722 /*
723 * Switch to idle mode (all ticks handled).
724 */
725 sbintime_t
cpu_idleclock(void)726 cpu_idleclock(void)
727 {
728 sbintime_t now, t;
729 struct pcpu_state *state;
730
731 if (idletick || busy ||
732 (periodic && (timer->et_flags & ET_FLAGS_PERCPU))
733 #ifdef DEVICE_POLLING
734 || curcpu == CPU_FIRST()
735 #endif
736 )
737 return (-1);
738 state = DPCPU_PTR(timerstate);
739 if (periodic)
740 now = state->now;
741 else
742 now = sbinuptime();
743 CTR3(KTR_SPARE2, "idle at %d: now %d.%08x",
744 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
745 t = getnextcpuevent(1);
746 ET_HW_LOCK(state);
747 state->idle = 1;
748 state->nextevent = t;
749 if (!periodic)
750 loadtimer(now, 0);
751 ET_HW_UNLOCK(state);
752 return (MAX(t - now, 0));
753 }
754
755 /*
756 * Switch to active mode (skip empty ticks).
757 */
758 void
cpu_activeclock(void)759 cpu_activeclock(void)
760 {
761 sbintime_t now;
762 struct pcpu_state *state;
763 struct thread *td;
764
765 state = DPCPU_PTR(timerstate);
766 if (state->idle == 0 || busy)
767 return;
768 if (periodic)
769 now = state->now;
770 else
771 now = sbinuptime();
772 CTR3(KTR_SPARE2, "active at %d: now %d.%08x",
773 curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
774 spinlock_enter();
775 td = curthread;
776 td->td_intr_nesting_level++;
777 handleevents(now, 1);
778 td->td_intr_nesting_level--;
779 spinlock_exit();
780 }
781
782 /*
783 * Change the frequency of the given timer. This changes et->et_frequency and
784 * if et is the active timer it reconfigures the timer on all CPUs. This is
785 * intended to be a private interface for the use of et_change_frequency() only.
786 */
787 void
cpu_et_frequency(struct eventtimer * et,uint64_t newfreq)788 cpu_et_frequency(struct eventtimer *et, uint64_t newfreq)
789 {
790
791 ET_LOCK();
792 if (et == timer) {
793 configtimer(0);
794 et->et_frequency = newfreq;
795 configtimer(1);
796 } else
797 et->et_frequency = newfreq;
798 ET_UNLOCK();
799 }
800
801 void
cpu_new_callout(int cpu,sbintime_t bt,sbintime_t bt_opt)802 cpu_new_callout(int cpu, sbintime_t bt, sbintime_t bt_opt)
803 {
804 struct pcpu_state *state;
805
806 /* Do not touch anything if somebody reconfiguring timers. */
807 if (busy)
808 return;
809 CTR6(KTR_SPARE2, "new co at %d: on %d at %d.%08x - %d.%08x",
810 curcpu, cpu, (int)(bt_opt >> 32), (u_int)(bt_opt & 0xffffffff),
811 (int)(bt >> 32), (u_int)(bt & 0xffffffff));
812 state = DPCPU_ID_PTR(cpu, timerstate);
813 ET_HW_LOCK(state);
814
815 /*
816 * If there is callout time already set earlier -- do nothing.
817 * This check may appear redundant because we check already in
818 * callout_process() but this double check guarantees we're safe
819 * with respect to race conditions between interrupts execution
820 * and scheduling.
821 */
822 state->nextcallopt = bt_opt;
823 if (bt >= state->nextcall)
824 goto done;
825 state->nextcall = bt;
826 /* If there is some other event set earlier -- do nothing. */
827 if (bt >= state->nextevent)
828 goto done;
829 state->nextevent = bt;
830 /* If timer is periodic -- there is nothing to reprogram. */
831 if (periodic)
832 goto done;
833 /* If timer is global or of the current CPU -- reprogram it. */
834 if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || cpu == curcpu) {
835 loadtimer(sbinuptime(), 0);
836 done:
837 ET_HW_UNLOCK(state);
838 return;
839 }
840 /* Otherwise make other CPU to reprogram it. */
841 state->handle = 1;
842 ET_HW_UNLOCK(state);
843 #ifdef SMP
844 ipi_cpu(cpu, IPI_HARDCLOCK);
845 #endif
846 }
847
848 /*
849 * Report or change the active event timers hardware.
850 */
851 static int
sysctl_kern_eventtimer_timer(SYSCTL_HANDLER_ARGS)852 sysctl_kern_eventtimer_timer(SYSCTL_HANDLER_ARGS)
853 {
854 char buf[32];
855 struct eventtimer *et;
856 int error;
857
858 ET_LOCK();
859 et = timer;
860 snprintf(buf, sizeof(buf), "%s", et->et_name);
861 ET_UNLOCK();
862 error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
863 ET_LOCK();
864 et = timer;
865 if (error != 0 || req->newptr == NULL ||
866 strcasecmp(buf, et->et_name) == 0) {
867 ET_UNLOCK();
868 return (error);
869 }
870 et = et_find(buf, 0, 0);
871 if (et == NULL) {
872 ET_UNLOCK();
873 return (ENOENT);
874 }
875 configtimer(0);
876 et_free(timer);
877 if (et->et_flags & ET_FLAGS_C3STOP)
878 cpu_disable_c3_sleep++;
879 if (timer->et_flags & ET_FLAGS_C3STOP)
880 cpu_disable_c3_sleep--;
881 periodic = want_periodic;
882 timer = et;
883 et_init(timer, timercb, NULL, NULL);
884 configtimer(1);
885 ET_UNLOCK();
886 return (error);
887 }
888 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, timer,
889 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE,
890 0, 0, sysctl_kern_eventtimer_timer, "A", "Chosen event timer");
891
892 /*
893 * Report or change the active event timer periodicity.
894 */
895 static int
sysctl_kern_eventtimer_periodic(SYSCTL_HANDLER_ARGS)896 sysctl_kern_eventtimer_periodic(SYSCTL_HANDLER_ARGS)
897 {
898 int error, val;
899
900 val = periodic;
901 error = sysctl_handle_int(oidp, &val, 0, req);
902 if (error != 0 || req->newptr == NULL)
903 return (error);
904 ET_LOCK();
905 configtimer(0);
906 periodic = want_periodic = val;
907 configtimer(1);
908 ET_UNLOCK();
909 return (error);
910 }
911 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, periodic,
912 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
913 0, 0, sysctl_kern_eventtimer_periodic, "I", "Enable event timer periodic mode");
914
915 #include "opt_ddb.h"
916
917 #ifdef DDB
918 #include <ddb/ddb.h>
919
DB_SHOW_COMMAND(clocksource,db_show_clocksource)920 DB_SHOW_COMMAND(clocksource, db_show_clocksource)
921 {
922 struct pcpu_state *st;
923 int c;
924
925 CPU_FOREACH(c) {
926 st = DPCPU_ID_PTR(c, timerstate);
927 db_printf(
928 "CPU %2d: action %d handle %d ipi %d idle %d\n"
929 " now %#jx nevent %#jx (%jd)\n"
930 " ntick %#jx (%jd) nhard %#jx (%jd)\n"
931 " nstat %#jx (%jd) nprof %#jx (%jd)\n"
932 " ncall %#jx (%jd) ncallopt %#jx (%jd)\n",
933 c, st->action, st->handle, st->ipi, st->idle,
934 (uintmax_t)st->now,
935 (uintmax_t)st->nextevent,
936 (uintmax_t)(st->nextevent - st->now) / tick_sbt,
937 (uintmax_t)st->nexttick,
938 (uintmax_t)(st->nexttick - st->now) / tick_sbt,
939 (uintmax_t)st->nexthard,
940 (uintmax_t)(st->nexthard - st->now) / tick_sbt,
941 (uintmax_t)st->nextstat,
942 (uintmax_t)(st->nextstat - st->now) / tick_sbt,
943 (uintmax_t)st->nextprof,
944 (uintmax_t)(st->nextprof - st->now) / tick_sbt,
945 (uintmax_t)st->nextcall,
946 (uintmax_t)(st->nextcall - st->now) / tick_sbt,
947 (uintmax_t)st->nextcallopt,
948 (uintmax_t)(st->nextcallopt - st->now) / tick_sbt);
949 }
950 }
951
952 #endif
953