freebsd-dev/usr.sbin/bhyve/pmtmr.c
Neel Natu 1caafc47a3 Use the correct type (uint64_t) to retrieve sysctl machdep.tsc_freq.
Simplify the function a bit by falling through after initialization and
return via the normal code path.

Reviewed by:	grehan
Obtained from:	NetApp
2013-01-25 06:27:03 +00:00

106 lines
2.8 KiB
C

/*-
* Copyright (c) 2012 NetApp, Inc.
* 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.
* 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 NETAPP, INC ``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 NETAPP, INC OR CONTRIBUTORS 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.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <machine/cpufunc.h>
#include <stdio.h>
#include <time.h>
#include <assert.h>
#include <pthread.h>
#include "inout.h"
/*
* The ACPI Power Management timer is a free-running 24- or 32-bit
* timer with a frequency of 3.579545MHz
*
* This implementation will be 32-bits
*/
#define IO_PMTMR 0x408 /* 4-byte i/o port for the timer */
#define PMTMR_FREQ 3579545 /* 3.579545MHz */
static pthread_mutex_t pmtmr_mtx;
static uint64_t pmtmr_tscf;
static uint64_t pmtmr_old;
static uint64_t pmtmr_tsc_old;
static uint32_t
pmtmr_val(void)
{
uint64_t pmtmr_tsc_new;
uint64_t pmtmr_new;
static int inited = 0;
if (!inited) {
size_t len;
inited = 1;
pthread_mutex_init(&pmtmr_mtx, NULL);
len = sizeof(pmtmr_tscf);
sysctlbyname("machdep.tsc_freq", &pmtmr_tscf, &len,
NULL, 0);
pmtmr_tsc_old = rdtsc();
pmtmr_old = pmtmr_tsc_old / pmtmr_tscf * PMTMR_FREQ;
}
pthread_mutex_lock(&pmtmr_mtx);
pmtmr_tsc_new = rdtsc();
pmtmr_new = (pmtmr_tsc_new - pmtmr_tsc_old) * PMTMR_FREQ / pmtmr_tscf +
pmtmr_old;
pmtmr_old = pmtmr_new;
pmtmr_tsc_old = pmtmr_tsc_new;
pthread_mutex_unlock(&pmtmr_mtx);
return (pmtmr_new);
}
static int
pmtmr_handler(struct vmctx *ctx, int vcpu, int in, int port, int bytes,
uint32_t *eax, void *arg)
{
assert(in == 1);
if (bytes != 4)
return (-1);
*eax = pmtmr_val();
return (0);
}
INOUT_PORT(pmtmr, IO_PMTMR, IOPORT_F_IN, pmtmr_handler);