root.cc revision 7861
12SN/A/* 21762SN/A * Copyright (c) 2002-2005 The Regents of The University of Michigan 37861Sgblack@eecs.umich.edu * Copyright (c) 2011 Advanced Micro Devices 42SN/A * All rights reserved. 52SN/A * 62SN/A * Redistribution and use in source and binary forms, with or without 72SN/A * modification, are permitted provided that the following conditions are 82SN/A * met: redistributions of source code must retain the above copyright 92SN/A * notice, this list of conditions and the following disclaimer; 102SN/A * redistributions in binary form must reproduce the above copyright 112SN/A * notice, this list of conditions and the following disclaimer in the 122SN/A * documentation and/or other materials provided with the distribution; 132SN/A * neither the name of the copyright holders nor the names of its 142SN/A * contributors may be used to endorse or promote products derived from 152SN/A * this software without specific prior written permission. 162SN/A * 172SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 182SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 192SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 202SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 212SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 222SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 232SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 242SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 252SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 262SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 272SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 282665Ssaidi@eecs.umich.edu * 292665Ssaidi@eecs.umich.edu * Authors: Nathan Binkert 302665Ssaidi@eecs.umich.edu * Steve Reinhardt 317861Sgblack@eecs.umich.edu * Gabe Black 322SN/A */ 332SN/A 34488SN/A#include "base/misc.hh" 357861Sgblack@eecs.umich.edu#include "sim/core.hh" 367861Sgblack@eecs.umich.edu#include "sim/root.hh" 371609SN/A 387861Sgblack@eecs.umich.eduRoot *Root::_root = NULL; 397861Sgblack@eecs.umich.edu 407861Sgblack@eecs.umich.edu/* 417861Sgblack@eecs.umich.edu * This function is called periodically by an event in M5 and ensures that 427861Sgblack@eecs.umich.edu * at least as much real time has passed between invocations as simulated time. 437861Sgblack@eecs.umich.edu * If not, the function either sleeps, or if the difference is small enough 447861Sgblack@eecs.umich.edu * spin waits. 457861Sgblack@eecs.umich.edu */ 467861Sgblack@eecs.umich.eduvoid 477861Sgblack@eecs.umich.eduRoot::timeSync() 482SN/A{ 497861Sgblack@eecs.umich.edu Time cur_time, diff, period = timeSyncPeriod(); 507861Sgblack@eecs.umich.edu 517861Sgblack@eecs.umich.edu do { 527861Sgblack@eecs.umich.edu cur_time.setTimer(); 537861Sgblack@eecs.umich.edu diff = cur_time - lastTime; 547861Sgblack@eecs.umich.edu Time remainder = period - diff; 557861Sgblack@eecs.umich.edu if (diff < period && remainder > _spinThreshold) { 567861Sgblack@eecs.umich.edu DPRINTF(TimeSync, "Sleeping to sync with real time.\n"); 577861Sgblack@eecs.umich.edu // Sleep until the end of the period, or until a signal. 587861Sgblack@eecs.umich.edu sleep(remainder); 597861Sgblack@eecs.umich.edu // Refresh the current time. 607861Sgblack@eecs.umich.edu cur_time.setTimer(); 617861Sgblack@eecs.umich.edu } 627861Sgblack@eecs.umich.edu } while (diff < period); 637861Sgblack@eecs.umich.edu lastTime = cur_time; 647861Sgblack@eecs.umich.edu schedule(&syncEvent, curTick() + _periodTick); 657861Sgblack@eecs.umich.edu} 667861Sgblack@eecs.umich.edu 677861Sgblack@eecs.umich.eduvoid 687861Sgblack@eecs.umich.eduRoot::timeSyncEnable(bool en) 697861Sgblack@eecs.umich.edu{ 707861Sgblack@eecs.umich.edu if (en == _enabled) 717861Sgblack@eecs.umich.edu return; 727861Sgblack@eecs.umich.edu _enabled = en; 737861Sgblack@eecs.umich.edu if (_enabled) { 747861Sgblack@eecs.umich.edu // Get event going. 757861Sgblack@eecs.umich.edu Tick periods = ((curTick() + _periodTick - 1) / _periodTick); 767861Sgblack@eecs.umich.edu Tick nextPeriod = periods * _periodTick; 777861Sgblack@eecs.umich.edu schedule(&syncEvent, nextPeriod); 787861Sgblack@eecs.umich.edu } else { 797861Sgblack@eecs.umich.edu // Stop event. 807861Sgblack@eecs.umich.edu deschedule(&syncEvent); 817861Sgblack@eecs.umich.edu } 827861Sgblack@eecs.umich.edu} 837861Sgblack@eecs.umich.edu 847861Sgblack@eecs.umich.edu/// Configure the period for time sync events. 857861Sgblack@eecs.umich.eduvoid 867861Sgblack@eecs.umich.eduRoot::timeSyncPeriod(Time newPeriod) 877861Sgblack@eecs.umich.edu{ 887861Sgblack@eecs.umich.edu bool en = timeSyncEnabled(); 897861Sgblack@eecs.umich.edu _period = newPeriod; 907861Sgblack@eecs.umich.edu _periodTick = _period.nsec() * SimClock::Int::ns + 917861Sgblack@eecs.umich.edu _period.sec() * SimClock::Int::s; 927861Sgblack@eecs.umich.edu timeSyncEnable(en); 937861Sgblack@eecs.umich.edu} 947861Sgblack@eecs.umich.edu 957861Sgblack@eecs.umich.edu/// Set the threshold for time remaining to spin wait. 967861Sgblack@eecs.umich.eduvoid 977861Sgblack@eecs.umich.eduRoot::timeSyncSpinThreshold(Time newThreshold) 987861Sgblack@eecs.umich.edu{ 997861Sgblack@eecs.umich.edu bool en = timeSyncEnabled(); 1007861Sgblack@eecs.umich.edu _spinThreshold = newThreshold; 1017861Sgblack@eecs.umich.edu timeSyncEnable(en); 1027861Sgblack@eecs.umich.edu} 1037861Sgblack@eecs.umich.edu 1047861Sgblack@eecs.umich.eduRoot::Root(RootParams *p) : SimObject(p), _enabled(false), 1057861Sgblack@eecs.umich.edu _periodTick(p->time_sync_period), syncEvent(this) 1067861Sgblack@eecs.umich.edu{ 1077861Sgblack@eecs.umich.edu uint64_t nsecs = p->time_sync_period / SimClock::Int::ns; 1087861Sgblack@eecs.umich.edu _period.set(nsecs / Time::NSEC_PER_SEC, nsecs % Time::NSEC_PER_SEC); 1097861Sgblack@eecs.umich.edu nsecs = p->time_sync_spin_threshold / SimClock::Int::ns; 1107861Sgblack@eecs.umich.edu _spinThreshold.set(nsecs / Time::NSEC_PER_SEC, 1117861Sgblack@eecs.umich.edu nsecs % Time::NSEC_PER_SEC); 1127861Sgblack@eecs.umich.edu 1137861Sgblack@eecs.umich.edu assert(_root == NULL); 1147861Sgblack@eecs.umich.edu _root = this; 1157861Sgblack@eecs.umich.edu lastTime.setTimer(); 1167861Sgblack@eecs.umich.edu timeSyncEnable(p->time_sync_enable); 1177861Sgblack@eecs.umich.edu} 1181104SN/A 1194762Snate@binkert.orgRoot * 1204762Snate@binkert.orgRootParams::create() 1211310SN/A{ 1221388SN/A static bool created = false; 1231388SN/A if (created) 1241388SN/A panic("only one root object allowed!"); 1251388SN/A 1261388SN/A created = true; 1271310SN/A 1284762Snate@binkert.org return new Root(this); 1291310SN/A} 130