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
hardclockintr(void)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
handleevents(sbintime_t now,int fake)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
getnextcpuevent(int idle)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
getnextevent(void)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
timercb(struct eventtimer * et,void * arg)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
loadtimer(sbintime_t now,int start)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
setuptimer(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
doconfigtimer(void)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
configtimer(int start)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
round_freq(struct eventtimer * et,int freq)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
cpu_initclocks_bsp(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
cpu_initclocks_ap(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
cpu_startprofclock(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
cpu_stopprofclock(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
cpu_idleclock(void)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
cpu_activeclock(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
cpu_et_frequency(struct eventtimer * et,uint64_t newfreq)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
cpu_new_callout(int cpu,sbintime_t bt,sbintime_t bt_opt)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
sysctl_kern_eventtimer_timer(SYSCTL_HANDLER_ARGS)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
sysctl_kern_eventtimer_periodic(SYSCTL_HANDLER_ARGS)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
DB_SHOW_COMMAND(clocksource,db_show_clocksource)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