timer.cc revision 9655 
1/*
2 * Copyright (c) 2012 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Andreas Sandberg
38 */
39
40#include <csignal>
41#include <ctime>
42
43#include "base/misc.hh"
44#include "base/trace.hh"
45#include "cpu/kvm/timer.hh"
46#include "debug/KvmTimer.hh"
47
48
49PosixKvmTimer::PosixKvmTimer(int signo, clockid_t clockID,
50                             float hostFactor, Tick hostFreq)
51    : BaseKvmTimer(signo, hostFactor, hostFreq),
52      clockID(clockID)
53{
54    struct sigevent sev;
55
56    // TODO: We should request signal delivery to thread instead of
57    // the process here. Unfortunately this seems to be broken, or at
58    // least not work as specified in the man page.
59    sev.sigev_notify = SIGEV_SIGNAL;
60    sev.sigev_signo = signo;
61    sev.sigev_value.sival_ptr = NULL;
62    if (timer_create(clockID, &sev, &timer) == -1)
63        panic("timer_create");
64}
65
66PosixKvmTimer::~PosixKvmTimer()
67{
68    timer_delete(timer);
69}
70
71void
72PosixKvmTimer::arm(Tick ticks)
73{
74    struct itimerspec ts;
75    memset(&ts, 0, sizeof(ts));
76
77    ts.it_interval.tv_sec = 0;
78    ts.it_interval.tv_nsec = 0;
79    ts.it_value.tv_sec = hostNs(ticks) / 1000000000ULL;
80    ts.it_value.tv_nsec = hostNs(ticks) % 1000000000ULL;
81
82    DPRINTF(KvmTimer, "Arming POSIX timer: %i ticks (%is%ins)\n",
83            ticks, ts.it_value.tv_sec, ts.it_value.tv_nsec);
84
85    if (timer_settime(timer, 0, &ts, NULL) == -1)
86        panic("PosixKvmTimer: Failed to arm timer\n");
87}
88
89void
90PosixKvmTimer::disarm()
91{
92    struct itimerspec ts;
93    memset(&ts, 0, sizeof(ts));
94
95    DPRINTF(KvmTimer, "Disarming POSIX timer\n");
96
97    if (timer_settime(timer, 0, &ts, NULL) == -1)
98        panic("PosixKvmTimer: Failed to disarm timer\n");
99}
100
101Tick
102PosixKvmTimer::calcResolution()
103{
104    struct timespec ts;
105
106    if (clock_getres(clockID, &ts) == -1)
107        panic("PosixKvmTimer: Failed to get timer resolution\n");
108
109    Tick resolution(ticksFromHostNs(ts.tv_sec * 1000000000ULL + ts.tv_nsec));
110
111    return resolution;
112}
113
114
115PerfKvmTimer::PerfKvmTimer(PerfKvmCounter &ctr,
116                           int signo, float hostFactor, Tick hostFreq)
117    : BaseKvmTimer(signo, hostFactor, hostFreq),
118      hwOverflow(ctr)
119{
120    hwOverflow.enableSignals(signo);
121}
122
123PerfKvmTimer::~PerfKvmTimer()
124{
125}
126
127void
128PerfKvmTimer::arm(Tick ticks)
129{
130    hwOverflow.period(hostCycles(ticks));
131    hwOverflow.refresh(1);
132}
133
134void
135PerfKvmTimer::disarm()
136{
137    hwOverflow.stop();
138}
139
140Tick
141PerfKvmTimer::calcResolution()
142{
143    // This is a bit arbitrary, but in practice, we can't really do
144    // anything useful in less than ~1000 anyway.
145    return ticksFromHostCycles(1000);
146}
147