vpmtmr.c revision 284900 
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 284900 2015-06-28 03:22:26Z neel $");
29
30#include <sys/param.h>
31#include <sys/queue.h>
32#include <sys/kernel.h>
33#include <sys/malloc.h>
34#include <sys/systm.h>
35
36#include <machine/vmm.h>
37
38#include "vpmtmr.h"
39
40/*
41 * The ACPI Power Management timer is a free-running 24- or 32-bit
42 * timer with a frequency of 3.579545MHz
43 *
44 * This implementation will be 32-bits
45 */
46
47#define PMTMR_FREQ	3579545  /* 3.579545MHz */
48
49struct vpmtmr {
50	sbintime_t	freq_sbt;
51	sbintime_t	baseuptime;
52	uint32_t	baseval;
53};
54
55static MALLOC_DEFINE(M_VPMTMR, "vpmtmr", "bhyve virtual acpi timer");
56
57struct vpmtmr *
58vpmtmr_init(struct vm *vm)
59{
60	struct vpmtmr *vpmtmr;
61	struct bintime bt;
62
63	vpmtmr = malloc(sizeof(struct vpmtmr), M_VPMTMR, M_WAITOK | M_ZERO);
64	vpmtmr->baseuptime = sbinuptime();
65	vpmtmr->baseval = 0;
66
67	FREQ2BT(PMTMR_FREQ, &bt);
68	vpmtmr->freq_sbt = bttosbt(bt);
69
70	return (vpmtmr);
71}
72
73void
74vpmtmr_cleanup(struct vpmtmr *vpmtmr)
75{
76
77	free(vpmtmr, M_VPMTMR);
78}
79
80int
81vpmtmr_handler(struct vm *vm, int vcpuid, bool in, int port, int bytes,
82    uint32_t *val)
83{
84	struct vpmtmr *vpmtmr;
85	sbintime_t now, delta;
86
87	if (!in || bytes != 4)
88		return (-1);
89
90	vpmtmr = vm_pmtmr(vm);
91
92	/*
93	 * No locking needed because 'baseuptime' and 'baseval' are
94	 * written only during initialization.
95	 */
96	now = sbinuptime();
97	delta = now - vpmtmr->baseuptime;
98	KASSERT(delta >= 0, ("vpmtmr_handler: uptime went backwards: "
99	    "%#lx to %#lx", vpmtmr->baseuptime, now));
100	*val = vpmtmr->baseval + delta / vpmtmr->freq_sbt;
101
102	return (0);
103}
104