1/*-
2 * Copyright (c) 2012 NetApp, Inc.
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 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/types.h>
33#include <sys/sysctl.h>
34#include <sys/time.h>
35#include <machine/cpufunc.h>
36
37#include <stdio.h>
38#include <stdlib.h>
39#include <time.h>
40#include <assert.h>
41#include <pthread.h>
42
43#include "acpi.h"
44#include "inout.h"
45
46/*
47 * The ACPI Power Management timer is a free-running 24- or 32-bit
48 * timer with a frequency of 3.579545MHz
49 *
50 * This implementation will be 32-bits
51 */
52
53#define PMTMR_FREQ	3579545  /* 3.579545MHz */
54
55static pthread_mutex_t pmtmr_mtx;
56static pthread_once_t pmtmr_once = PTHREAD_ONCE_INIT;
57
58static uint64_t	pmtmr_old;
59
60static uint64_t	pmtmr_tscf;
61static uint64_t	pmtmr_tsc_old;
62
63static clockid_t clockid = CLOCK_UPTIME_FAST;
64static struct timespec pmtmr_uptime_old;
65
66#define	timespecsub(vvp, uvp)						\
67	do {								\
68		(vvp)->tv_sec -= (uvp)->tv_sec;				\
69		(vvp)->tv_nsec -= (uvp)->tv_nsec;			\
70		if ((vvp)->tv_nsec < 0) {				\
71			(vvp)->tv_sec--;				\
72			(vvp)->tv_nsec += 1000000000;			\
73		}							\
74	} while (0)
75
76static uint64_t
77timespec_to_pmtmr(const struct timespec *tsnew, const struct timespec *tsold)
78{
79	struct timespec tsdiff;
80	int64_t nsecs;
81
82	tsdiff = *tsnew;
83	timespecsub(&tsdiff, tsold);
84	nsecs = tsdiff.tv_sec * 1000000000 + tsdiff.tv_nsec;
85	assert(nsecs >= 0);
86
87	return (nsecs * PMTMR_FREQ / 1000000000 + pmtmr_old);
88}
89
90static uint64_t
91tsc_to_pmtmr(uint64_t tsc_new, uint64_t tsc_old)
92{
93
94	return ((tsc_new - tsc_old) * PMTMR_FREQ / pmtmr_tscf + pmtmr_old);
95}
96
97static void
98pmtmr_init(void)
99{
100	size_t len;
101	int smp_tsc, err;
102	struct timespec tsnew, tsold = { 0 };
103
104	len = sizeof(smp_tsc);
105	err = sysctlbyname("kern.timecounter.smp_tsc", &smp_tsc, &len, NULL, 0);
106	assert(err == 0);
107
108	if (smp_tsc) {
109		len = sizeof(pmtmr_tscf);
110		err = sysctlbyname("machdep.tsc_freq", &pmtmr_tscf, &len,
111				   NULL, 0);
112		assert(err == 0);
113
114		pmtmr_tsc_old = rdtsc();
115		pmtmr_old = tsc_to_pmtmr(pmtmr_tsc_old, 0);
116	} else {
117		if (getenv("BHYVE_PMTMR_PRECISE") != NULL)
118			clockid = CLOCK_UPTIME;
119
120		err = clock_gettime(clockid, &tsnew);
121		assert(err == 0);
122
123		pmtmr_uptime_old = tsnew;
124		pmtmr_old = timespec_to_pmtmr(&tsnew, &tsold);
125	}
126	pthread_mutex_init(&pmtmr_mtx, NULL);
127}
128
129static uint32_t
130pmtmr_val(void)
131{
132	struct timespec	tsnew;
133	uint64_t	pmtmr_tsc_new;
134	uint64_t	pmtmr_new;
135	int		error;
136
137	pthread_once(&pmtmr_once, pmtmr_init);
138
139	pthread_mutex_lock(&pmtmr_mtx);
140
141	if (pmtmr_tscf) {
142		pmtmr_tsc_new = rdtsc();
143		pmtmr_new = tsc_to_pmtmr(pmtmr_tsc_new, pmtmr_tsc_old);
144		pmtmr_tsc_old = pmtmr_tsc_new;
145	} else {
146		error = clock_gettime(clockid, &tsnew);
147		assert(error == 0);
148
149		pmtmr_new = timespec_to_pmtmr(&tsnew, &pmtmr_uptime_old);
150		pmtmr_uptime_old = tsnew;
151	}
152	pmtmr_old = pmtmr_new;
153
154	pthread_mutex_unlock(&pmtmr_mtx);
155
156	return (pmtmr_new);
157}
158
159static int
160pmtmr_handler(struct vmctx *ctx, int vcpu, int in, int port, int bytes,
161	          uint32_t *eax, void *arg)
162{
163	assert(in == 1);
164
165	if (bytes != 4)
166		return (-1);
167
168	*eax = pmtmr_val();
169
170	return (0);
171}
172
173INOUT_PORT(pmtmr, IO_PMTMR, IOPORT_F_IN, pmtmr_handler);
174