packet_queue.cc revision 10423:cc7f3988c5a9
111348Sandreas.sandberg@arm.com/* 211470Sandreas.sandberg@arm.com * Copyright (c) 2012 ARM Limited 311348Sandreas.sandberg@arm.com * All rights reserved. 411348Sandreas.sandberg@arm.com * 511348Sandreas.sandberg@arm.com * The license below extends only to copyright in the software and shall 611348Sandreas.sandberg@arm.com * not be construed as granting a license to any other intellectual 711348Sandreas.sandberg@arm.com * property including but not limited to intellectual property relating 811348Sandreas.sandberg@arm.com * to a hardware implementation of the functionality of the software 911348Sandreas.sandberg@arm.com * licensed hereunder. You may use the software subject to the license 1011348Sandreas.sandberg@arm.com * terms below provided that you ensure that this notice is replicated 1111348Sandreas.sandberg@arm.com * unmodified and in its entirety in all distributions of the software, 1211348Sandreas.sandberg@arm.com * modified or unmodified, in source code or in binary form. 1311348Sandreas.sandberg@arm.com * 1411348Sandreas.sandberg@arm.com * Copyright (c) 2006 The Regents of The University of Michigan 1511348Sandreas.sandberg@arm.com * All rights reserved. 1611348Sandreas.sandberg@arm.com * 1711348Sandreas.sandberg@arm.com * Redistribution and use in source and binary forms, with or without 1811348Sandreas.sandberg@arm.com * modification, are permitted provided that the following conditions are 1911348Sandreas.sandberg@arm.com * met: redistributions of source code must retain the above copyright 2011348Sandreas.sandberg@arm.com * notice, this list of conditions and the following disclaimer; 2111348Sandreas.sandberg@arm.com * redistributions in binary form must reproduce the above copyright 2211348Sandreas.sandberg@arm.com * notice, this list of conditions and the following disclaimer in the 2311348Sandreas.sandberg@arm.com * documentation and/or other materials provided with the distribution; 2411348Sandreas.sandberg@arm.com * neither the name of the copyright holders nor the names of its 2511348Sandreas.sandberg@arm.com * contributors may be used to endorse or promote products derived from 2611348Sandreas.sandberg@arm.com * this software without specific prior written permission. 2711348Sandreas.sandberg@arm.com * 2811348Sandreas.sandberg@arm.com * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 2911348Sandreas.sandberg@arm.com * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 3011348Sandreas.sandberg@arm.com * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 3111348Sandreas.sandberg@arm.com * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 3211348Sandreas.sandberg@arm.com * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 3311348Sandreas.sandberg@arm.com * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 3411348Sandreas.sandberg@arm.com * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 3511348Sandreas.sandberg@arm.com * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 3611348Sandreas.sandberg@arm.com * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 3711348Sandreas.sandberg@arm.com * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 3811348Sandreas.sandberg@arm.com * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 3911348Sandreas.sandberg@arm.com * 4011348Sandreas.sandberg@arm.com * Authors: Ali Saidi 4111348Sandreas.sandberg@arm.com * Andreas Hansson 4211348Sandreas.sandberg@arm.com */ 4311348Sandreas.sandberg@arm.com 4411348Sandreas.sandberg@arm.com#include "base/trace.hh" 4511348Sandreas.sandberg@arm.com#include "debug/Drain.hh" 4611348Sandreas.sandberg@arm.com#include "debug/PacketQueue.hh" 4711348Sandreas.sandberg@arm.com#include "mem/packet_queue.hh" 4811348Sandreas.sandberg@arm.com 4911348Sandreas.sandberg@arm.comusing namespace std; 5011348Sandreas.sandberg@arm.com 5111348Sandreas.sandberg@arm.comPacketQueue::PacketQueue(EventManager& _em, const std::string& _label) 5211348Sandreas.sandberg@arm.com : em(_em), sendEvent(this), drainManager(NULL), label(_label), 5311348Sandreas.sandberg@arm.com waitingOnRetry(false) 5411348Sandreas.sandberg@arm.com{ 5511348Sandreas.sandberg@arm.com} 5611348Sandreas.sandberg@arm.com 5711348Sandreas.sandberg@arm.comPacketQueue::~PacketQueue() 5811348Sandreas.sandberg@arm.com{ 5911348Sandreas.sandberg@arm.com} 6011348Sandreas.sandberg@arm.com 6111348Sandreas.sandberg@arm.comvoid 6211348Sandreas.sandberg@arm.comPacketQueue::retry() 6311348Sandreas.sandberg@arm.com{ 6411348Sandreas.sandberg@arm.com DPRINTF(PacketQueue, "Queue %s received retry\n", name()); 6511348Sandreas.sandberg@arm.com assert(waitingOnRetry); 6611348Sandreas.sandberg@arm.com sendDeferredPacket(); 6711348Sandreas.sandberg@arm.com} 6811348Sandreas.sandberg@arm.com 6911348Sandreas.sandberg@arm.combool 7011348Sandreas.sandberg@arm.comPacketQueue::checkFunctional(PacketPtr pkt) 7111348Sandreas.sandberg@arm.com{ 7211348Sandreas.sandberg@arm.com pkt->pushLabel(label); 7311348Sandreas.sandberg@arm.com 7411348Sandreas.sandberg@arm.com auto i = transmitList.begin(); 7511348Sandreas.sandberg@arm.com bool found = false; 7611348Sandreas.sandberg@arm.com 7711348Sandreas.sandberg@arm.com while (!found && i != transmitList.end()) { 7811348Sandreas.sandberg@arm.com // If the buffered packet contains data, and it overlaps the 7911348Sandreas.sandberg@arm.com // current packet, then update data 8011348Sandreas.sandberg@arm.com found = pkt->checkFunctional(i->pkt); 8111348Sandreas.sandberg@arm.com ++i; 8211348Sandreas.sandberg@arm.com } 8311348Sandreas.sandberg@arm.com 8411348Sandreas.sandberg@arm.com pkt->popLabel(); 8511348Sandreas.sandberg@arm.com 8611348Sandreas.sandberg@arm.com return found; 8711348Sandreas.sandberg@arm.com} 8811348Sandreas.sandberg@arm.com 8911348Sandreas.sandberg@arm.comvoid 9011348Sandreas.sandberg@arm.comPacketQueue::schedSendEvent(Tick when) 9111348Sandreas.sandberg@arm.com{ 9211348Sandreas.sandberg@arm.com // if we are waiting on a retry, do not schedule a send event, and 9311348Sandreas.sandberg@arm.com // instead rely on retry being called 9411348Sandreas.sandberg@arm.com if (waitingOnRetry) { 9511348Sandreas.sandberg@arm.com assert(!sendEvent.scheduled()); 9611348Sandreas.sandberg@arm.com return; 9711348Sandreas.sandberg@arm.com } 9811348Sandreas.sandberg@arm.com 9911348Sandreas.sandberg@arm.com if (!sendEvent.scheduled()) { 10011348Sandreas.sandberg@arm.com em.schedule(&sendEvent, when); 10111348Sandreas.sandberg@arm.com } else if (sendEvent.when() > when) { 10211348Sandreas.sandberg@arm.com em.reschedule(&sendEvent, when); 10311348Sandreas.sandberg@arm.com } 10411348Sandreas.sandberg@arm.com} 10511348Sandreas.sandberg@arm.com 10611348Sandreas.sandberg@arm.comvoid 10711348Sandreas.sandberg@arm.comPacketQueue::schedSendTiming(PacketPtr pkt, Tick when, bool send_as_snoop) 10811348Sandreas.sandberg@arm.com{ 10911470Sandreas.sandberg@arm.com DPRINTF(PacketQueue, "%s for %s address %x size %d\n", __func__, 11011348Sandreas.sandberg@arm.com pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 11112761Sandreas.sandberg@arm.com // we can still send a packet before the end of this tick 11212761Sandreas.sandberg@arm.com assert(when >= curTick()); 11311348Sandreas.sandberg@arm.com 11411348Sandreas.sandberg@arm.com // express snoops should never be queued 11511348Sandreas.sandberg@arm.com assert(!pkt->isExpressSnoop()); 11611348Sandreas.sandberg@arm.com 11711348Sandreas.sandberg@arm.com // add a very basic sanity check on the port to ensure the 11811348Sandreas.sandberg@arm.com // invisible buffer is not growing beyond reasonable limits 11911348Sandreas.sandberg@arm.com if (transmitList.size() > 100) { 12011348Sandreas.sandberg@arm.com panic("Packet queue %s has grown beyond 100 packets\n", 12111348Sandreas.sandberg@arm.com name()); 12211348Sandreas.sandberg@arm.com } 12311348Sandreas.sandberg@arm.com 12411348Sandreas.sandberg@arm.com // nothing on the list, or earlier than current front element, 12511348Sandreas.sandberg@arm.com // schedule an event 12611348Sandreas.sandberg@arm.com if (transmitList.empty() || when < transmitList.front().tick) { 12711348Sandreas.sandberg@arm.com // note that currently we ignore a potentially outstanding retry 12811348Sandreas.sandberg@arm.com // and could in theory put a new packet at the head of the 12911348Sandreas.sandberg@arm.com // transmit list before retrying the existing packet 13011348Sandreas.sandberg@arm.com transmitList.push_front(DeferredPacket(when, pkt, send_as_snoop)); 13111348Sandreas.sandberg@arm.com schedSendEvent(when); 13211348Sandreas.sandberg@arm.com return; 13311348Sandreas.sandberg@arm.com } 13411348Sandreas.sandberg@arm.com 13512761Sandreas.sandberg@arm.com // list is non-empty and this belongs at the end 13611348Sandreas.sandberg@arm.com if (when >= transmitList.back().tick) { 13711348Sandreas.sandberg@arm.com transmitList.push_back(DeferredPacket(when, pkt, send_as_snoop)); 13811348Sandreas.sandberg@arm.com return; 13912761Sandreas.sandberg@arm.com } 14012761Sandreas.sandberg@arm.com 14111348Sandreas.sandberg@arm.com // this belongs in the middle somewhere, insertion sort 14211348Sandreas.sandberg@arm.com auto i = transmitList.begin(); 14311348Sandreas.sandberg@arm.com ++i; // already checked for insertion at front 144 while (i != transmitList.end() && when >= i->tick) 145 ++i; 146 transmitList.insert(i, DeferredPacket(when, pkt, send_as_snoop)); 147} 148 149void PacketQueue::trySendTiming() 150{ 151 assert(deferredPacketReady()); 152 153 DeferredPacket dp = transmitList.front(); 154 155 // use the appropriate implementation of sendTiming based on the 156 // type of port associated with the queue, and whether the packet 157 // is to be sent as a snoop or not 158 waitingOnRetry = !sendTiming(dp.pkt, dp.sendAsSnoop); 159 160 if (!waitingOnRetry) { 161 // take the packet off the list 162 transmitList.pop_front(); 163 } 164} 165 166void 167PacketQueue::scheduleSend(Tick time) 168{ 169 // the next ready time is either determined by the next deferred packet, 170 // or in the cache through the MSHR ready time 171 Tick nextReady = std::max(std::min(deferredPacketReadyTime(), time), 172 curTick() + 1); 173 174 if (nextReady != MaxTick) { 175 // if the sendTiming caused someone else to call our 176 // recvTiming we could already have an event scheduled, check 177 if (!sendEvent.scheduled()) { 178 em.schedule(&sendEvent, nextReady); 179 } else if (nextReady < sendEvent.when()) { 180 // if the new time is earlier than when the event 181 // currently is scheduled, move it forward 182 em.reschedule(&sendEvent, nextReady); 183 } 184 } else { 185 // no more to send, so if we're draining, we may be done 186 if (drainManager && transmitList.empty() && !sendEvent.scheduled()) { 187 DPRINTF(Drain, "PacketQueue done draining," 188 "processing drain event\n"); 189 drainManager->signalDrainDone(); 190 drainManager = NULL; 191 } 192 } 193} 194 195void 196PacketQueue::sendDeferredPacket() 197{ 198 // try to send what is on the list, this will set waitingOnRetry 199 // accordingly 200 trySendTiming(); 201 202 // if we succeeded and are not waiting for a retry, schedule the 203 // next send 204 if (!waitingOnRetry) { 205 scheduleSend(); 206 } 207} 208 209void 210PacketQueue::processSendEvent() 211{ 212 assert(!waitingOnRetry); 213 sendDeferredPacket(); 214} 215 216unsigned int 217PacketQueue::drain(DrainManager *dm) 218{ 219 if (transmitList.empty()) 220 return 0; 221 DPRINTF(Drain, "PacketQueue not drained\n"); 222 drainManager = dm; 223 return 1; 224} 225 226MasterPacketQueue::MasterPacketQueue(EventManager& _em, MasterPort& _masterPort, 227 const std::string _label) 228 : PacketQueue(_em, _label), masterPort(_masterPort) 229{ 230} 231 232bool 233MasterPacketQueue::sendTiming(PacketPtr pkt, bool send_as_snoop) 234{ 235 // attempt to send the packet and return according to the outcome 236 if (!send_as_snoop) 237 return masterPort.sendTimingReq(pkt); 238 else 239 return masterPort.sendTimingSnoopResp(pkt); 240} 241 242SlavePacketQueue::SlavePacketQueue(EventManager& _em, SlavePort& _slavePort, 243 const std::string _label) 244 : PacketQueue(_em, _label), slavePort(_slavePort) 245{ 246} 247 248bool 249SlavePacketQueue::sendTiming(PacketPtr pkt, bool send_as_snoop) 250{ 251 // we should never have queued snoop requests 252 assert(!send_as_snoop); 253 return slavePort.sendTimingResp(pkt); 254} 255