timer.cc revision 11793:ef606668d247
112647Santhony.gutierrez@amd.com/* 212647Santhony.gutierrez@amd.com * Copyright (c) 2012 ARM Limited 311308Santhony.gutierrez@amd.com * All rights reserved 412647Santhony.gutierrez@amd.com * 511308Santhony.gutierrez@amd.com * The license below extends only to copyright in the software and shall 612647Santhony.gutierrez@amd.com * not be construed as granting a license to any other intellectual 712647Santhony.gutierrez@amd.com * property including but not limited to intellectual property relating 811308Santhony.gutierrez@amd.com * to a hardware implementation of the functionality of the software 912647Santhony.gutierrez@amd.com * licensed hereunder. You may use the software subject to the license 1012647Santhony.gutierrez@amd.com * terms below provided that you ensure that this notice is replicated 1111308Santhony.gutierrez@amd.com * unmodified and in its entirety in all distributions of the software, 1212647Santhony.gutierrez@amd.com * modified or unmodified, in source code or in binary form. 1312647Santhony.gutierrez@amd.com * 1412647Santhony.gutierrez@amd.com * Redistribution and use in source and binary forms, with or without 1511308Santhony.gutierrez@amd.com * modification, are permitted provided that the following conditions are 1612647Santhony.gutierrez@amd.com * met: redistributions of source code must retain the above copyright 1712647Santhony.gutierrez@amd.com * notice, this list of conditions and the following disclaimer; 1812647Santhony.gutierrez@amd.com * redistributions in binary form must reproduce the above copyright 1911308Santhony.gutierrez@amd.com * notice, this list of conditions and the following disclaimer in the 2012647Santhony.gutierrez@amd.com * documentation and/or other materials provided with the distribution; 2112647Santhony.gutierrez@amd.com * neither the name of the copyright holders nor the names of its 2212647Santhony.gutierrez@amd.com * contributors may be used to endorse or promote products derived from 2312647Santhony.gutierrez@amd.com * this software without specific prior written permission. 2412647Santhony.gutierrez@amd.com * 2512647Santhony.gutierrez@amd.com * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 2612647Santhony.gutierrez@amd.com * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 2712647Santhony.gutierrez@amd.com * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 2812647Santhony.gutierrez@amd.com * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 2912647Santhony.gutierrez@amd.com * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 3012647Santhony.gutierrez@amd.com * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 3111308Santhony.gutierrez@amd.com * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 3212647Santhony.gutierrez@amd.com * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 3311308Santhony.gutierrez@amd.com * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 3411308Santhony.gutierrez@amd.com * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 3511308Santhony.gutierrez@amd.com * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 3611308Santhony.gutierrez@amd.com * 3711308Santhony.gutierrez@amd.com * Authors: Andreas Sandberg 3813400Sodanrc@yahoo.com.br */ 3911308Santhony.gutierrez@amd.com 4011308Santhony.gutierrez@amd.com#include "cpu/kvm/timer.hh" 4111308Santhony.gutierrez@amd.com 4213400Sodanrc@yahoo.com.br#include <sys/syscall.h> 4313400Sodanrc@yahoo.com.br#include <unistd.h> 4411670Sandreas.hansson@arm.com 4511670Sandreas.hansson@arm.com#include <algorithm> 4611308Santhony.gutierrez@amd.com#include <csignal> 4711308Santhony.gutierrez@amd.com#include <ctime> 4811308Santhony.gutierrez@amd.com 4911308Santhony.gutierrez@amd.com#include "base/misc.hh" 5011308Santhony.gutierrez@amd.com#include "base/trace.hh" 5111308Santhony.gutierrez@amd.com#include "debug/KvmTimer.hh" 5211308Santhony.gutierrez@amd.com 5311308Santhony.gutierrez@amd.com/* According to timer_create(2), the value SIGEV_THREAD_ID can be used 5411308Santhony.gutierrez@amd.com * to specify which thread a timer signal gets delivered to. According 5511308Santhony.gutierrez@amd.com * to the man page, the member sigev_notify_thread is used to specify 5611308Santhony.gutierrez@amd.com * the TID. This member is currently not defined by default in 5711308Santhony.gutierrez@amd.com * siginfo.h on x86, so we define it here as a workaround. 5811308Santhony.gutierrez@amd.com */ 5911308Santhony.gutierrez@amd.com#ifndef sigev_notify_thread_id 6011308Santhony.gutierrez@amd.com#define sigev_notify_thread_id _sigev_un._tid 6111308Santhony.gutierrez@amd.com#endif 6211308Santhony.gutierrez@amd.com 6311308Santhony.gutierrez@amd.comstatic pid_t 6411308Santhony.gutierrez@amd.comgettid() 6511308Santhony.gutierrez@amd.com{ 6611308Santhony.gutierrez@amd.com return syscall(__NR_gettid); 6711308Santhony.gutierrez@amd.com} 6811308Santhony.gutierrez@amd.com 6911308Santhony.gutierrez@amd.com/** 7011308Santhony.gutierrez@amd.com * Minimum number of cycles that a host can spend in a KVM call (used 7111308Santhony.gutierrez@amd.com * to calculate the resolution of some timers). 7211308Santhony.gutierrez@amd.com * 7311308Santhony.gutierrez@amd.com * The value of this constant is a bit arbitrary, but in practice, we 7411308Santhony.gutierrez@amd.com * can't really do anything useful in less than ~1000 cycles. 7511308Santhony.gutierrez@amd.com */ 7611308Santhony.gutierrez@amd.comstatic const uint64_t MIN_HOST_CYCLES = 1000; 7711308Santhony.gutierrez@amd.com 7811308Santhony.gutierrez@amd.comPosixKvmTimer::PosixKvmTimer(int signo, clockid_t clockID, 7911308Santhony.gutierrez@amd.com float hostFactor, Tick hostFreq) 8011308Santhony.gutierrez@amd.com : BaseKvmTimer(signo, hostFactor, hostFreq), 8111308Santhony.gutierrez@amd.com clockID(clockID) 8211308Santhony.gutierrez@amd.com{ 8311308Santhony.gutierrez@amd.com struct sigevent sev; 8411308Santhony.gutierrez@amd.com 8511308Santhony.gutierrez@amd.com sev.sigev_notify = SIGEV_THREAD_ID; 8611308Santhony.gutierrez@amd.com sev.sigev_signo = signo; 8711308Santhony.gutierrez@amd.com sev.sigev_notify_thread_id = gettid(); 8811308Santhony.gutierrez@amd.com sev.sigev_value.sival_ptr = NULL; 8911308Santhony.gutierrez@amd.com 9011308Santhony.gutierrez@amd.com while (timer_create(clockID, &sev, &timer) == -1) { 9111308Santhony.gutierrez@amd.com if (errno != EAGAIN) 9211308Santhony.gutierrez@amd.com panic("timer_create: %i", errno); 9311308Santhony.gutierrez@amd.com } 9411308Santhony.gutierrez@amd.com} 9511308Santhony.gutierrez@amd.com 9611308Santhony.gutierrez@amd.comPosixKvmTimer::~PosixKvmTimer() 9711308Santhony.gutierrez@amd.com{ 9811308Santhony.gutierrez@amd.com timer_delete(timer); 9911308Santhony.gutierrez@amd.com} 10011308Santhony.gutierrez@amd.com 10111308Santhony.gutierrez@amd.comvoid 10211308Santhony.gutierrez@amd.comPosixKvmTimer::arm(Tick ticks) 10311308Santhony.gutierrez@amd.com{ 10411308Santhony.gutierrez@amd.com struct itimerspec ts; 10511308Santhony.gutierrez@amd.com memset(&ts, 0, sizeof(ts)); 10611308Santhony.gutierrez@amd.com 10711308Santhony.gutierrez@amd.com ts.it_interval.tv_sec = 0; 10811308Santhony.gutierrez@amd.com ts.it_interval.tv_nsec = 0; 10911308Santhony.gutierrez@amd.com ts.it_value.tv_sec = hostNs(ticks) / 1000000000ULL; 11011308Santhony.gutierrez@amd.com ts.it_value.tv_nsec = hostNs(ticks) % 1000000000ULL; 11111308Santhony.gutierrez@amd.com 11211308Santhony.gutierrez@amd.com assert(ts.it_value.tv_nsec > 0 || ts.it_value.tv_sec > 0); 11311308Santhony.gutierrez@amd.com 11411308Santhony.gutierrez@amd.com DPRINTF(KvmTimer, "Arming POSIX timer: %i ticks (%is%ins)\n", 11511308Santhony.gutierrez@amd.com ticks, ts.it_value.tv_sec, ts.it_value.tv_nsec); 11611308Santhony.gutierrez@amd.com 11711308Santhony.gutierrez@amd.com if (timer_settime(timer, 0, &ts, NULL) == -1) 11811308Santhony.gutierrez@amd.com panic("PosixKvmTimer: Failed to arm timer\n"); 11911308Santhony.gutierrez@amd.com} 12011308Santhony.gutierrez@amd.com 12111308Santhony.gutierrez@amd.comvoid 12211308Santhony.gutierrez@amd.comPosixKvmTimer::disarm() 12311308Santhony.gutierrez@amd.com{ 12411308Santhony.gutierrez@amd.com struct itimerspec ts; 12511308Santhony.gutierrez@amd.com memset(&ts, 0, sizeof(ts)); 12611308Santhony.gutierrez@amd.com 12711308Santhony.gutierrez@amd.com DPRINTF(KvmTimer, "Disarming POSIX timer\n"); 12811308Santhony.gutierrez@amd.com 12911308Santhony.gutierrez@amd.com if (timer_settime(timer, 0, &ts, NULL) == -1) 13011308Santhony.gutierrez@amd.com panic("PosixKvmTimer: Failed to disarm timer\n"); 13111308Santhony.gutierrez@amd.com} 13211308Santhony.gutierrez@amd.com 13311308Santhony.gutierrez@amd.comTick 13411308Santhony.gutierrez@amd.comPosixKvmTimer::calcResolution() 13511308Santhony.gutierrez@amd.com{ 13611308Santhony.gutierrez@amd.com struct timespec ts; 13711308Santhony.gutierrez@amd.com 13811308Santhony.gutierrez@amd.com if (clock_getres(clockID, &ts) == -1) 13911308Santhony.gutierrez@amd.com panic("PosixKvmTimer: Failed to get timer resolution\n"); 14011308Santhony.gutierrez@amd.com 14111308Santhony.gutierrez@amd.com const uint64_t res_ns(ts.tv_sec * 1000000000ULL + ts.tv_nsec); 14211308Santhony.gutierrez@amd.com // We preferrably want ticksFromHostNs() to calculate the the 14311308Santhony.gutierrez@amd.com // ceiling rather than truncating the value. However, there are 14411308Santhony.gutierrez@amd.com // other cases where truncating is fine, so we just add 1 here to 14511308Santhony.gutierrez@amd.com // make sure that the actual resolution is strictly less than what 14611308Santhony.gutierrez@amd.com // we return. We could get all kinds of nasty behavior if 14711308Santhony.gutierrez@amd.com // arm(resolution) is called and the resulting time is 0 (which 14811308Santhony.gutierrez@amd.com // could happen if we truncate the results and the resolution is 14911308Santhony.gutierrez@amd.com // 1ns). 15011308Santhony.gutierrez@amd.com const Tick resolution(ticksFromHostNs(res_ns) + 1); 15111308Santhony.gutierrez@amd.com // It might not make sense to enter into KVM for less than a 15211308Santhony.gutierrez@amd.com // certain number of host cycles. In some systems (e.g., Linux) 15311308Santhony.gutierrez@amd.com // the resolution of the timer we use is 1ns (a few cycles on most 15411308Santhony.gutierrez@amd.com // CPUs), which isn't very useful. 15511308Santhony.gutierrez@amd.com const Tick min_cycles(ticksFromHostCycles(MIN_HOST_CYCLES)); 15611308Santhony.gutierrez@amd.com 15711308Santhony.gutierrez@amd.com return std::max(resolution, min_cycles); 15811308Santhony.gutierrez@amd.com} 15911308Santhony.gutierrez@amd.com 16011308Santhony.gutierrez@amd.com 16111308Santhony.gutierrez@amd.comPerfKvmTimer::PerfKvmTimer(PerfKvmCounter &ctr, 16211308Santhony.gutierrez@amd.com int signo, float hostFactor, Tick hostFreq) 16311308Santhony.gutierrez@amd.com : BaseKvmTimer(signo, hostFactor, hostFreq), 16411308Santhony.gutierrez@amd.com hwOverflow(ctr) 16511308Santhony.gutierrez@amd.com{ 16611308Santhony.gutierrez@amd.com hwOverflow.enableSignals(signo); 16711308Santhony.gutierrez@amd.com} 16811308Santhony.gutierrez@amd.com 16911308Santhony.gutierrez@amd.comPerfKvmTimer::~PerfKvmTimer() 17011308Santhony.gutierrez@amd.com{ 17111308Santhony.gutierrez@amd.com} 17211308Santhony.gutierrez@amd.com 17311308Santhony.gutierrez@amd.comvoid 17411308Santhony.gutierrez@amd.comPerfKvmTimer::arm(Tick ticks) 17511308Santhony.gutierrez@amd.com{ 17611308Santhony.gutierrez@amd.com hwOverflow.period(hostCycles(ticks)); 17711308Santhony.gutierrez@amd.com hwOverflow.refresh(1); 17811308Santhony.gutierrez@amd.com} 17911308Santhony.gutierrez@amd.com 18011308Santhony.gutierrez@amd.comvoid 18111308Santhony.gutierrez@amd.comPerfKvmTimer::disarm() 18211308Santhony.gutierrez@amd.com{ 18311308Santhony.gutierrez@amd.com hwOverflow.stop(); 18411308Santhony.gutierrez@amd.com} 18511308Santhony.gutierrez@amd.com 18611308Santhony.gutierrez@amd.comTick 18711308Santhony.gutierrez@amd.comPerfKvmTimer::calcResolution() 18811308Santhony.gutierrez@amd.com{ 18911308Santhony.gutierrez@amd.com return ticksFromHostCycles(MIN_HOST_CYCLES); 19011308Santhony.gutierrez@amd.com} 19111308Santhony.gutierrez@amd.com