src/cpu/kvm/timer.cc

   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
  49 PosixKvmTimer::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
  66 PosixKvmTimer::~PosixKvmTimer()
  67 {
  68     timer_delete(timer);
  69 }
  70
  71 void
  72 PosixKvmTimer::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
  89 void
  90 PosixKvmTimer::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
 101 Tick
 102 PosixKvmTimer::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 }