vpmtmr.c revision 276429 
1/*-
2 * Copyright (c) 2014, Neel Natu (neel@freebsd.org)
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 unmodified, this list of conditions, and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/10/sys/amd64/vmm/io/vpmtmr.c 276429 2014-12-30 22:22:46Z neel $");
29
30#include <sys/param.h>
31#include <sys/queue.h>
32#include <sys/cpuset.h>
33#include <sys/kernel.h>
34#include <sys/malloc.h>
35#include <sys/systm.h>
36
37#include <machine/vmm.h>
38
39#include "vpmtmr.h"
40
41/*
42 * The ACPI Power Management timer is a free-running 24- or 32-bit
43 * timer with a frequency of 3.579545MHz
44 *
45 * This implementation will be 32-bits
46 */
47
48#define PMTMR_FREQ	3579545  /* 3.579545MHz */
49
50struct vpmtmr {
51	sbintime_t	freq_sbt;
52	sbintime_t	baseuptime;
53	uint32_t	baseval;
54};
55
56static MALLOC_DEFINE(M_VPMTMR, "vpmtmr", "bhyve virtual acpi timer");
57
58struct vpmtmr *
59vpmtmr_init(struct vm *vm)
60{
61	struct vpmtmr *vpmtmr;
62	struct bintime bt;
63
64	vpmtmr = malloc(sizeof(struct vpmtmr), M_VPMTMR, M_WAITOK | M_ZERO);
65	vpmtmr->baseuptime = sbinuptime();
66	vpmtmr->baseval = 0;
67
68	FREQ2BT(PMTMR_FREQ, &bt);
69	vpmtmr->freq_sbt = bttosbt(bt);
70
71	return (vpmtmr);
72}
73
74void
75vpmtmr_cleanup(struct vpmtmr *vpmtmr)
76{
77
78	free(vpmtmr, M_VPMTMR);
79}
80
81int
82vpmtmr_handler(struct vm *vm, int vcpuid, bool in, int port, int bytes,
83    uint32_t *val)
84{
85	struct vpmtmr *vpmtmr;
86	sbintime_t now, delta;
87
88	if (!in || bytes != 4)
89		return (-1);
90
91	vpmtmr = vm_pmtmr(vm);
92
93	/*
94	 * No locking needed because 'baseuptime' and 'baseval' are
95	 * written only during initialization.
96	 */
97	now = sbinuptime();
98	delta = now - vpmtmr->baseuptime;
99	KASSERT(delta >= 0, ("vpmtmr_handler: uptime went backwards: "
100	    "%#lx to %#lx", vpmtmr->baseuptime, now));
101	*val = vpmtmr->baseval + delta / vpmtmr->freq_sbt;
102
103	return (0);
104}
105