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/*-
* 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/queue.h>
#include <sys/timeet.h>
#include "opt_timer.h"
SLIST_HEAD(et_eventtimers_list, eventtimer);
static struct et_eventtimers_list eventtimers = SLIST_HEAD_INITIALIZER(et_eventtimers);
struct mtx et_eventtimers_mtx;
MTX_SYSINIT(et_eventtimers_init, &et_eventtimers_mtx, "et_mtx", MTX_DEF);
SYSCTL_NODE(_kern, OID_AUTO, eventtimer, CTLFLAG_RW, 0, "Event timers");
static SYSCTL_NODE(_kern_eventtimer, OID_AUTO, et, CTLFLAG_RW, 0, "");
/*
* Register a new event timer hardware.
*/
int
et_register(struct eventtimer *et)
{
struct eventtimer *tmp, *next;
if (et->et_quality >= 0 || bootverbose) {
if (et->et_frequency == 0) {
printf("Event timer \"%s\" quality %d\n",
et->et_name, et->et_quality);
} else {
printf("Event timer \"%s\" "
"frequency %ju Hz quality %d\n",
et->et_name, (uintmax_t)et->et_frequency,
et->et_quality);
}
}
KASSERT(et->et_start, ("et_register: timer has no start function"));
et->et_sysctl = SYSCTL_ADD_NODE(NULL,
SYSCTL_STATIC_CHILDREN(_kern_eventtimer_et), OID_AUTO, et->et_name,
CTLFLAG_RW, 0, "event timer description");
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO,
"flags", CTLFLAG_RD, &(et->et_flags), 0,
"Event timer capabilities");
SYSCTL_ADD_UQUAD(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO,
"frequency", CTLFLAG_RD, &(et->et_frequency),
"Event timer base frequency");
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO,
"quality", CTLFLAG_RD, &(et->et_quality), 0,
"Goodness of event timer");
ET_LOCK();
if (SLIST_EMPTY(&eventtimers) ||
SLIST_FIRST(&eventtimers)->et_quality < et->et_quality) {
SLIST_INSERT_HEAD(&eventtimers, et, et_all);
} else {
SLIST_FOREACH(tmp, &eventtimers, et_all) {
next = SLIST_NEXT(tmp, et_all);
if (next == NULL || next->et_quality < et->et_quality) {
SLIST_INSERT_AFTER(tmp, et, et_all);
break;
}
}
}
ET_UNLOCK();
return (0);
}
/*
* Deregister event timer hardware.
*/
int
et_deregister(struct eventtimer *et)
{
int err = 0;
if (et->et_deregister_cb != NULL) {
if ((err = et->et_deregister_cb(et, et->et_arg)) != 0)
return (err);
}
ET_LOCK();
SLIST_REMOVE(&eventtimers, et, eventtimer, et_all);
ET_UNLOCK();
sysctl_remove_oid(et->et_sysctl, 1, 1);
return (0);
}
/*
* Change the frequency of the given timer. If it is the active timer,
* reconfigure it on all CPUs (reschedules all current events based on the new
* timer frequency).
*/
void
et_change_frequency(struct eventtimer *et, uint64_t newfreq)
{
#ifndef NO_EVENTTIMERS
cpu_et_frequency(et, newfreq);
#endif
}
/*
* Find free event timer hardware with specified parameters.
*/
struct eventtimer *
et_find(const char *name, int check, int want)
{
struct eventtimer *et = NULL;
SLIST_FOREACH(et, &eventtimers, et_all) {
if (et->et_active)
continue;
if (name != NULL && strcasecmp(et->et_name, name) != 0)
continue;
if (name == NULL && et->et_quality < 0)
continue;
if ((et->et_flags & check) != want)
continue;
break;
}
return (et);
}
/*
* Initialize event timer hardware. Set callbacks.
*/
int
et_init(struct eventtimer *et, et_event_cb_t *event,
et_deregister_cb_t *deregister, void *arg)
{
if (event == NULL)
return (EINVAL);
if (et->et_active)
return (EBUSY);
et->et_active = 1;
et->et_event_cb = event;
et->et_deregister_cb = deregister;
et->et_arg = arg;
return (0);
}
/*
* Start event timer hardware.
* first - delay before first tick.
* period - period of subsequent periodic ticks.
*/
int
et_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
{
if (!et->et_active)
return (ENXIO);
KASSERT(period >= 0, ("et_start: negative period"));
KASSERT((et->et_flags & ET_FLAGS_PERIODIC) || period == 0,
("et_start: period specified for oneshot-only timer"));
KASSERT((et->et_flags & ET_FLAGS_ONESHOT) || period != 0,
("et_start: period not specified for periodic-only timer"));
if (period != 0) {
if (period < et->et_min_period)
period = et->et_min_period;
else if (period > et->et_max_period)
period = et->et_max_period;
}
if (period == 0 || first != 0) {
if (first < et->et_min_period)
first = et->et_min_period;
else if (first > et->et_max_period)
first = et->et_max_period;
}
return (et->et_start(et, first, period));
}
/* Stop event timer hardware. */
int
et_stop(struct eventtimer *et)
{
if (!et->et_active)
return (ENXIO);
if (et->et_stop)
return (et->et_stop(et));
return (0);
}
/* Mark event timer hardware as broken. */
int
et_ban(struct eventtimer *et)
{
et->et_flags &= ~(ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT);
return (0);
}
/* Free event timer hardware. */
int
et_free(struct eventtimer *et)
{
if (!et->et_active)
return (ENXIO);
et->et_active = 0;
return (0);
}
/* Report list of supported event timer hardware via sysctl. */
static int
sysctl_kern_eventtimer_choice(SYSCTL_HANDLER_ARGS)
{
struct sbuf sb;
struct eventtimer *et;
int error;
sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL);
ET_LOCK();
SLIST_FOREACH(et, &eventtimers, et_all) {
if (et != SLIST_FIRST(&eventtimers))
sbuf_putc(&sb, ' ');
sbuf_printf(&sb, "%s(%d)", et->et_name, et->et_quality);
}
ET_UNLOCK();
error = sbuf_finish(&sb);
if (error == 0)
error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
sbuf_delete(&sb);
return (error);
}
SYSCTL_PROC(_kern_eventtimer, OID_AUTO, choice,
CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
0, 0, sysctl_kern_eventtimer_choice, "A", "Present event timers");
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