HardenedBSD/sys/kern/kern_et.c
Pedro F. Giffuni 8a36da99de sys/kern: adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:20:12 +00:00

268 lines
7.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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_WITH_LABEL(NULL,
SYSCTL_STATIC_CHILDREN(_kern_eventtimer_et), OID_AUTO, et->et_name,
CTLFLAG_RW, 0, "event timer description", "eventtimer");
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");