freebsd-dev/sys/kern/kern_clocksource.c
Alexander Motin e37e08c7bf Fix periodic per-CPU timers startup on boot.
Reported by:	neel
MFC after:	2 weeks
2013-12-16 13:52:18 +00:00

950 lines
22 KiB
C

/*-
* Copyright (c) 2010-2013 Alexander Motin <mav@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer,
* without modification, immediately at the beginning of the file.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Common routines to manage event timers hardware.
*/
#include "opt_device_polling.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/kdb.h>
#include <sys/ktr.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <machine/atomic.h>
#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/smp.h>
#ifdef KDTRACE_HOOKS
#include <sys/dtrace_bsd.h>
cyclic_clock_func_t cyclic_clock_func = NULL;
#endif
int cpu_can_deep_sleep = 0; /* C3 state is available. */
int cpu_disable_deep_sleep = 0; /* Timer dies in C3. */
static void setuptimer(void);
static void loadtimer(sbintime_t now, int first);
static int doconfigtimer(void);
static void configtimer(int start);
static int round_freq(struct eventtimer *et, int freq);
static sbintime_t getnextcpuevent(int idle);
static sbintime_t getnextevent(void);
static int handleevents(sbintime_t now, int fake);
static struct mtx et_hw_mtx;
#define ET_HW_LOCK(state) \
{ \
if (timer->et_flags & ET_FLAGS_PERCPU) \
mtx_lock_spin(&(state)->et_hw_mtx); \
else \
mtx_lock_spin(&et_hw_mtx); \
}
#define ET_HW_UNLOCK(state) \
{ \
if (timer->et_flags & ET_FLAGS_PERCPU) \
mtx_unlock_spin(&(state)->et_hw_mtx); \
else \
mtx_unlock_spin(&et_hw_mtx); \
}
static struct eventtimer *timer = NULL;
static sbintime_t timerperiod; /* Timer period for periodic mode. */
static sbintime_t statperiod; /* statclock() events period. */
static sbintime_t profperiod; /* profclock() events period. */
static sbintime_t nexttick; /* Next global timer tick time. */
static u_int busy = 1; /* Reconfiguration is in progress. */
static int profiling = 0; /* Profiling events enabled. */
static char timername[32]; /* Wanted timer. */
TUNABLE_STR("kern.eventtimer.timer", timername, sizeof(timername));
static int singlemul = 0; /* Multiplier for periodic mode. */
TUNABLE_INT("kern.eventtimer.singlemul", &singlemul);
SYSCTL_INT(_kern_eventtimer, OID_AUTO, singlemul, CTLFLAG_RW, &singlemul,
0, "Multiplier for periodic mode");
static u_int idletick = 0; /* Run periodic events when idle. */
TUNABLE_INT("kern.eventtimer.idletick", &idletick);
SYSCTL_UINT(_kern_eventtimer, OID_AUTO, idletick, CTLFLAG_RW, &idletick,
0, "Run periodic events when idle");
static int periodic = 0; /* Periodic or one-shot mode. */
static int want_periodic = 0; /* What mode to prefer. */
TUNABLE_INT("kern.eventtimer.periodic", &want_periodic);
struct pcpu_state {
struct mtx et_hw_mtx; /* Per-CPU timer mutex. */
u_int action; /* Reconfiguration requests. */
u_int handle; /* Immediate handle resuests. */
sbintime_t now; /* Last tick time. */
sbintime_t nextevent; /* Next scheduled event on this CPU. */
sbintime_t nexttick; /* Next timer tick time. */
sbintime_t nexthard; /* Next hardlock() event. */
sbintime_t nextstat; /* Next statclock() event. */
sbintime_t nextprof; /* Next profclock() event. */
sbintime_t nextcall; /* Next callout event. */
sbintime_t nextcallopt; /* Next optional callout event. */
#ifdef KDTRACE_HOOKS
sbintime_t nextcyc; /* Next OpenSolaris cyclics event. */
#endif
int ipi; /* This CPU needs IPI. */
int idle; /* This CPU is in idle mode. */
};
static DPCPU_DEFINE(struct pcpu_state, timerstate);
DPCPU_DEFINE(sbintime_t, hardclocktime);
/*
* Timer broadcast IPI handler.
*/
int
hardclockintr(void)
{
sbintime_t now;
struct pcpu_state *state;
int done;
if (doconfigtimer() || busy)
return (FILTER_HANDLED);
state = DPCPU_PTR(timerstate);
now = state->now;
CTR3(KTR_SPARE2, "ipi at %d: now %d.%08x",
curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
done = handleevents(now, 0);
return (done ? FILTER_HANDLED : FILTER_STRAY);
}
/*
* Handle all events for specified time on this CPU
*/
static int
handleevents(sbintime_t now, int fake)
{
sbintime_t t, *hct;
struct trapframe *frame;
struct pcpu_state *state;
int usermode;
int done, runs;
CTR3(KTR_SPARE2, "handle at %d: now %d.%08x",
curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
done = 0;
if (fake) {
frame = NULL;
usermode = 0;
} else {
frame = curthread->td_intr_frame;
usermode = TRAPF_USERMODE(frame);
}
state = DPCPU_PTR(timerstate);
runs = 0;
while (now >= state->nexthard) {
state->nexthard += tick_sbt;
runs++;
}
if (runs) {
hct = DPCPU_PTR(hardclocktime);
*hct = state->nexthard - tick_sbt;
if (fake < 2) {
hardclock_cnt(runs, usermode);
done = 1;
}
}
runs = 0;
while (now >= state->nextstat) {
state->nextstat += statperiod;
runs++;
}
if (runs && fake < 2) {
statclock_cnt(runs, usermode);
done = 1;
}
if (profiling) {
runs = 0;
while (now >= state->nextprof) {
state->nextprof += profperiod;
runs++;
}
if (runs && !fake) {
profclock_cnt(runs, usermode, TRAPF_PC(frame));
done = 1;
}
} else
state->nextprof = state->nextstat;
if (now >= state->nextcallopt) {
state->nextcall = state->nextcallopt = INT64_MAX;
callout_process(now);
}
#ifdef KDTRACE_HOOKS
if (fake == 0 && now >= state->nextcyc && cyclic_clock_func != NULL) {
state->nextcyc = INT64_MAX;
(*cyclic_clock_func)(frame);
}
#endif
t = getnextcpuevent(0);
ET_HW_LOCK(state);
if (!busy) {
state->idle = 0;
state->nextevent = t;
loadtimer(now, (fake == 2) &&
(timer->et_flags & ET_FLAGS_PERCPU));
}
ET_HW_UNLOCK(state);
return (done);
}
/*
* Schedule binuptime of the next event on current CPU.
*/
static sbintime_t
getnextcpuevent(int idle)
{
sbintime_t event;
struct pcpu_state *state;
u_int hardfreq;
state = DPCPU_PTR(timerstate);
/* Handle hardclock() events, skipping some if CPU is idle. */
event = state->nexthard;
if (idle) {
hardfreq = (u_int)hz / 2;
if (tc_min_ticktock_freq > 2
#ifdef SMP
&& curcpu == CPU_FIRST()
#endif
)
hardfreq = hz / tc_min_ticktock_freq;
if (hardfreq > 1)
event += tick_sbt * (hardfreq - 1);
}
/* Handle callout events. */
if (event > state->nextcall)
event = state->nextcall;
if (!idle) { /* If CPU is active - handle other types of events. */
if (event > state->nextstat)
event = state->nextstat;
if (profiling && event > state->nextprof)
event = state->nextprof;
}
#ifdef KDTRACE_HOOKS
if (event > state->nextcyc)
event = state->nextcyc;
#endif
return (event);
}
/*
* Schedule binuptime of the next event on all CPUs.
*/
static sbintime_t
getnextevent(void)
{
struct pcpu_state *state;
sbintime_t event;
#ifdef SMP
int cpu;
#endif
int c;
state = DPCPU_PTR(timerstate);
event = state->nextevent;
c = -1;
#ifdef SMP
if ((timer->et_flags & ET_FLAGS_PERCPU) == 0) {
CPU_FOREACH(cpu) {
state = DPCPU_ID_PTR(cpu, timerstate);
if (event > state->nextevent) {
event = state->nextevent;
c = cpu;
}
}
}
#endif
CTR4(KTR_SPARE2, "next at %d: next %d.%08x by %d",
curcpu, (int)(event >> 32), (u_int)(event & 0xffffffff), c);
return (event);
}
/* Hardware timer callback function. */
static void
timercb(struct eventtimer *et, void *arg)
{
sbintime_t now;
sbintime_t *next;
struct pcpu_state *state;
#ifdef SMP
int cpu, bcast;
#endif
/* Do not touch anything if somebody reconfiguring timers. */
if (busy)
return;
/* Update present and next tick times. */
state = DPCPU_PTR(timerstate);
if (et->et_flags & ET_FLAGS_PERCPU) {
next = &state->nexttick;
} else
next = &nexttick;
now = sbinuptime();
if (periodic)
*next = now + timerperiod;
else
*next = -1; /* Next tick is not scheduled yet. */
state->now = now;
CTR3(KTR_SPARE2, "intr at %d: now %d.%08x",
curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
#ifdef SMP
/* Prepare broadcasting to other CPUs for non-per-CPU timers. */
bcast = 0;
if ((et->et_flags & ET_FLAGS_PERCPU) == 0 && smp_started) {
CPU_FOREACH(cpu) {
state = DPCPU_ID_PTR(cpu, timerstate);
ET_HW_LOCK(state);
state->now = now;
if (now >= state->nextevent) {
state->nextevent += SBT_1S;
if (curcpu != cpu) {
state->ipi = 1;
bcast = 1;
}
}
ET_HW_UNLOCK(state);
}
}
#endif
/* Handle events for this time on this CPU. */
handleevents(now, 0);
#ifdef SMP
/* Broadcast interrupt to other CPUs for non-per-CPU timers. */
if (bcast) {
CPU_FOREACH(cpu) {
if (curcpu == cpu)
continue;
state = DPCPU_ID_PTR(cpu, timerstate);
if (state->ipi) {
state->ipi = 0;
ipi_cpu(cpu, IPI_HARDCLOCK);
}
}
}
#endif
}
/*
* Load new value into hardware timer.
*/
static void
loadtimer(sbintime_t now, int start)
{
struct pcpu_state *state;
sbintime_t new;
sbintime_t *next;
uint64_t tmp;
int eq;
if (timer->et_flags & ET_FLAGS_PERCPU) {
state = DPCPU_PTR(timerstate);
next = &state->nexttick;
} else
next = &nexttick;
if (periodic) {
if (start) {
/*
* Try to start all periodic timers aligned
* to period to make events synchronous.
*/
tmp = now % timerperiod;
new = timerperiod - tmp;
if (new < tmp) /* Left less then passed. */
new += timerperiod;
CTR5(KTR_SPARE2, "load p at %d: now %d.%08x first in %d.%08x",
curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff),
(int)(new >> 32), (u_int)(new & 0xffffffff));
*next = new + now;
et_start(timer, new, timerperiod);
}
} else {
new = getnextevent();
eq = (new == *next);
CTR4(KTR_SPARE2, "load at %d: next %d.%08x eq %d",
curcpu, (int)(new >> 32), (u_int)(new & 0xffffffff), eq);
if (!eq) {
*next = new;
et_start(timer, new - now, 0);
}
}
}
/*
* Prepare event timer parameters after configuration changes.
*/
static void
setuptimer(void)
{
int freq;
if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0)
periodic = 0;
else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0)
periodic = 1;
singlemul = MIN(MAX(singlemul, 1), 20);
freq = hz * singlemul;
while (freq < (profiling ? profhz : stathz))
freq += hz;
freq = round_freq(timer, freq);
timerperiod = SBT_1S / freq;
}
/*
* Reconfigure specified per-CPU timer on other CPU. Called from IPI handler.
*/
static int
doconfigtimer(void)
{
sbintime_t now;
struct pcpu_state *state;
state = DPCPU_PTR(timerstate);
switch (atomic_load_acq_int(&state->action)) {
case 1:
now = sbinuptime();
ET_HW_LOCK(state);
loadtimer(now, 1);
ET_HW_UNLOCK(state);
state->handle = 0;
atomic_store_rel_int(&state->action, 0);
return (1);
case 2:
ET_HW_LOCK(state);
et_stop(timer);
ET_HW_UNLOCK(state);
state->handle = 0;
atomic_store_rel_int(&state->action, 0);
return (1);
}
if (atomic_readandclear_int(&state->handle) && !busy) {
now = sbinuptime();
handleevents(now, 0);
return (1);
}
return (0);
}
/*
* Reconfigure specified timer.
* For per-CPU timers use IPI to make other CPUs to reconfigure.
*/
static void
configtimer(int start)
{
sbintime_t now, next;
struct pcpu_state *state;
int cpu;
if (start) {
setuptimer();
now = sbinuptime();
} else
now = 0;
critical_enter();
ET_HW_LOCK(DPCPU_PTR(timerstate));
if (start) {
/* Initialize time machine parameters. */
next = now + timerperiod;
if (periodic)
nexttick = next;
else
nexttick = -1;
CPU_FOREACH(cpu) {
state = DPCPU_ID_PTR(cpu, timerstate);
state->now = now;
if (!smp_started && cpu != CPU_FIRST())
state->nextevent = INT64_MAX;
else
state->nextevent = next;
if (periodic)
state->nexttick = next;
else
state->nexttick = -1;
state->nexthard = next;
state->nextstat = next;
state->nextprof = next;
state->nextcall = next;
state->nextcallopt = next;
hardclock_sync(cpu);
}
busy = 0;
/* Start global timer or per-CPU timer of this CPU. */
loadtimer(now, 1);
} else {
busy = 1;
/* Stop global timer or per-CPU timer of this CPU. */
et_stop(timer);
}
ET_HW_UNLOCK(DPCPU_PTR(timerstate));
#ifdef SMP
/* If timer is global or there is no other CPUs yet - we are done. */
if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || !smp_started) {
critical_exit();
return;
}
/* Set reconfigure flags for other CPUs. */
CPU_FOREACH(cpu) {
state = DPCPU_ID_PTR(cpu, timerstate);
atomic_store_rel_int(&state->action,
(cpu == curcpu) ? 0 : ( start ? 1 : 2));
}
/* Broadcast reconfigure IPI. */
ipi_all_but_self(IPI_HARDCLOCK);
/* Wait for reconfiguration completed. */
restart:
cpu_spinwait();
CPU_FOREACH(cpu) {
if (cpu == curcpu)
continue;
state = DPCPU_ID_PTR(cpu, timerstate);
if (atomic_load_acq_int(&state->action))
goto restart;
}
#endif
critical_exit();
}
/*
* Calculate nearest frequency supported by hardware timer.
*/
static int
round_freq(struct eventtimer *et, int freq)
{
uint64_t div;
if (et->et_frequency != 0) {
div = lmax((et->et_frequency + freq / 2) / freq, 1);
if (et->et_flags & ET_FLAGS_POW2DIV)
div = 1 << (flsl(div + div / 2) - 1);
freq = (et->et_frequency + div / 2) / div;
}
if (et->et_min_period > SBT_1S)
panic("Event timer \"%s\" doesn't support sub-second periods!",
et->et_name);
else if (et->et_min_period != 0)
freq = min(freq, SBT2FREQ(et->et_min_period));
if (et->et_max_period < SBT_1S && et->et_max_period != 0)
freq = max(freq, SBT2FREQ(et->et_max_period));
return (freq);
}
/*
* Configure and start event timers (BSP part).
*/
void
cpu_initclocks_bsp(void)
{
struct pcpu_state *state;
int base, div, cpu;
mtx_init(&et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN);
CPU_FOREACH(cpu) {
state = DPCPU_ID_PTR(cpu, timerstate);
mtx_init(&state->et_hw_mtx, "et_hw_mtx", NULL, MTX_SPIN);
#ifdef KDTRACE_HOOKS
state->nextcyc = INT64_MAX;
#endif
state->nextcall = INT64_MAX;
state->nextcallopt = INT64_MAX;
}
periodic = want_periodic;
/* Grab requested timer or the best of present. */
if (timername[0])
timer = et_find(timername, 0, 0);
if (timer == NULL && periodic) {
timer = et_find(NULL,
ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC);
}
if (timer == NULL) {
timer = et_find(NULL,
ET_FLAGS_ONESHOT, ET_FLAGS_ONESHOT);
}
if (timer == NULL && !periodic) {
timer = et_find(NULL,
ET_FLAGS_PERIODIC, ET_FLAGS_PERIODIC);
}
if (timer == NULL)
panic("No usable event timer found!");
et_init(timer, timercb, NULL, NULL);
/* Adapt to timer capabilities. */
if (periodic && (timer->et_flags & ET_FLAGS_PERIODIC) == 0)
periodic = 0;
else if (!periodic && (timer->et_flags & ET_FLAGS_ONESHOT) == 0)
periodic = 1;
if (timer->et_flags & ET_FLAGS_C3STOP)
cpu_disable_deep_sleep++;
/*
* We honor the requested 'hz' value.
* We want to run stathz in the neighborhood of 128hz.
* We would like profhz to run as often as possible.
*/
if (singlemul <= 0 || singlemul > 20) {
if (hz >= 1500 || (hz % 128) == 0)
singlemul = 1;
else if (hz >= 750)
singlemul = 2;
else
singlemul = 4;
}
if (periodic) {
base = round_freq(timer, hz * singlemul);
singlemul = max((base + hz / 2) / hz, 1);
hz = (base + singlemul / 2) / singlemul;
if (base <= 128)
stathz = base;
else {
div = base / 128;
if (div >= singlemul && (div % singlemul) == 0)
div++;
stathz = base / div;
}
profhz = stathz;
while ((profhz + stathz) <= 128 * 64)
profhz += stathz;
profhz = round_freq(timer, profhz);
} else {
hz = round_freq(timer, hz);
stathz = round_freq(timer, 127);
profhz = round_freq(timer, stathz * 64);
}
tick = 1000000 / hz;
tick_sbt = SBT_1S / hz;
tick_bt = sbttobt(tick_sbt);
statperiod = SBT_1S / stathz;
profperiod = SBT_1S / profhz;
ET_LOCK();
configtimer(1);
ET_UNLOCK();
}
/*
* Start per-CPU event timers on APs.
*/
void
cpu_initclocks_ap(void)
{
sbintime_t now;
struct pcpu_state *state;
struct thread *td;
state = DPCPU_PTR(timerstate);
now = sbinuptime();
ET_HW_LOCK(state);
state->now = now;
hardclock_sync(curcpu);
spinlock_enter();
ET_HW_UNLOCK(state);
td = curthread;
td->td_intr_nesting_level++;
handleevents(state->now, 2);
td->td_intr_nesting_level--;
spinlock_exit();
}
/*
* Switch to profiling clock rates.
*/
void
cpu_startprofclock(void)
{
ET_LOCK();
if (profiling == 0) {
if (periodic) {
configtimer(0);
profiling = 1;
configtimer(1);
} else
profiling = 1;
} else
profiling++;
ET_UNLOCK();
}
/*
* Switch to regular clock rates.
*/
void
cpu_stopprofclock(void)
{
ET_LOCK();
if (profiling == 1) {
if (periodic) {
configtimer(0);
profiling = 0;
configtimer(1);
} else
profiling = 0;
} else
profiling--;
ET_UNLOCK();
}
/*
* Switch to idle mode (all ticks handled).
*/
sbintime_t
cpu_idleclock(void)
{
sbintime_t now, t;
struct pcpu_state *state;
if (idletick || busy ||
(periodic && (timer->et_flags & ET_FLAGS_PERCPU))
#ifdef DEVICE_POLLING
|| curcpu == CPU_FIRST()
#endif
)
return (-1);
state = DPCPU_PTR(timerstate);
if (periodic)
now = state->now;
else
now = sbinuptime();
CTR3(KTR_SPARE2, "idle at %d: now %d.%08x",
curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
t = getnextcpuevent(1);
ET_HW_LOCK(state);
state->idle = 1;
state->nextevent = t;
if (!periodic)
loadtimer(now, 0);
ET_HW_UNLOCK(state);
return (MAX(t - now, 0));
}
/*
* Switch to active mode (skip empty ticks).
*/
void
cpu_activeclock(void)
{
sbintime_t now;
struct pcpu_state *state;
struct thread *td;
state = DPCPU_PTR(timerstate);
if (state->idle == 0 || busy)
return;
if (periodic)
now = state->now;
else
now = sbinuptime();
CTR3(KTR_SPARE2, "active at %d: now %d.%08x",
curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff));
spinlock_enter();
td = curthread;
td->td_intr_nesting_level++;
handleevents(now, 1);
td->td_intr_nesting_level--;
spinlock_exit();
}
#ifdef KDTRACE_HOOKS
void
clocksource_cyc_set(const struct bintime *bt)
{
sbintime_t now, t;
struct pcpu_state *state;
/* Do not touch anything if somebody reconfiguring timers. */
if (busy)
return;
t = bttosbt(*bt);
state = DPCPU_PTR(timerstate);
if (periodic)
now = state->now;
else
now = sbinuptime();
CTR5(KTR_SPARE2, "set_cyc at %d: now %d.%08x t %d.%08x",
curcpu, (int)(now >> 32), (u_int)(now & 0xffffffff),
(int)(t >> 32), (u_int)(t & 0xffffffff));
ET_HW_LOCK(state);
if (t == state->nextcyc)
goto done;
state->nextcyc = t;
if (t >= state->nextevent)
goto done;
state->nextevent = t;
if (!periodic)
loadtimer(now, 0);
done:
ET_HW_UNLOCK(state);
}
#endif
void
cpu_new_callout(int cpu, sbintime_t bt, sbintime_t bt_opt)
{
struct pcpu_state *state;
/* Do not touch anything if somebody reconfiguring timers. */
if (busy)
return;
CTR6(KTR_SPARE2, "new co at %d: on %d at %d.%08x - %d.%08x",
curcpu, cpu, (int)(bt_opt >> 32), (u_int)(bt_opt & 0xffffffff),
(int)(bt >> 32), (u_int)(bt & 0xffffffff));
state = DPCPU_ID_PTR(cpu, timerstate);
ET_HW_LOCK(state);
/*
* If there is callout time already set earlier -- do nothing.
* This check may appear redundant because we check already in
* callout_process() but this double check guarantees we're safe
* with respect to race conditions between interrupts execution
* and scheduling.
*/
state->nextcallopt = bt_opt;
if (bt >= state->nextcall)
goto done;
state->nextcall = bt;
/* If there is some other event set earlier -- do nothing. */
if (bt >= state->nextevent)
goto done;
state->nextevent = bt;
/* If timer is periodic -- there is nothing to reprogram. */
if (periodic)
goto done;
/* If timer is global or of the current CPU -- reprogram it. */
if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 || cpu == curcpu) {
loadtimer(sbinuptime(), 0);
done:
ET_HW_UNLOCK(state);
return;
}
/* Otherwise make other CPU to reprogram it. */
state->handle = 1;
ET_HW_UNLOCK(state);
#ifdef SMP
ipi_cpu(cpu, IPI_HARDCLOCK);
#endif
}
/*
* Report or change the active event timers hardware.
*/
static int
sysctl_kern_eventtimer_timer(SYSCTL_HANDLER_ARGS)
{
char buf[32];
struct eventtimer *et;
int error;
ET_LOCK();
et = timer;
snprintf(buf, sizeof(buf), "%s", et->et_name);
ET_UNLOCK();
error = sysctl_handle_string(oidp, buf, sizeof(buf), req);
ET_LOCK();
et = timer;
if (error != 0 || req->newptr == NULL ||
strcasecmp(buf, et->et_name) == 0) {
ET_UNLOCK();
return (error);
}
et = et_find(buf, 0, 0);
if (et == NULL) {
ET_UNLOCK();
return (ENOENT);
}
configtimer(0);
et_free(timer);
if (et->et_flags & ET_FLAGS_C3STOP)
cpu_disable_deep_sleep++;
if (timer->et_flags & ET_FLAGS_C3STOP)
cpu_disable_deep_sleep--;
periodic = want_periodic;
timer = et;
et_init(timer, timercb, NULL, NULL);
configtimer(1);
ET_UNLOCK();
return (error);
}
SYSCTL_PROC(_kern_eventtimer, OID_AUTO, timer,
CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE,
0, 0, sysctl_kern_eventtimer_timer, "A", "Chosen event timer");
/*
* Report or change the active event timer periodicity.
*/
static int
sysctl_kern_eventtimer_periodic(SYSCTL_HANDLER_ARGS)
{
int error, val;
val = periodic;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
ET_LOCK();
configtimer(0);
periodic = want_periodic = val;
configtimer(1);
ET_UNLOCK();
return (error);
}
SYSCTL_PROC(_kern_eventtimer, OID_AUTO, periodic,
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
0, 0, sysctl_kern_eventtimer_periodic, "I", "Enable event timer periodic mode");