packet_queue.cc revision 13564
12914SN/A/* 210713Sandreas.hansson@arm.com * Copyright (c) 2012,2015,2018 ARM Limited 38856SN/A * All rights reserved. 48856SN/A * 58856SN/A * The license below extends only to copyright in the software and shall 68856SN/A * not be construed as granting a license to any other intellectual 78856SN/A * property including but not limited to intellectual property relating 88856SN/A * to a hardware implementation of the functionality of the software 98856SN/A * licensed hereunder. You may use the software subject to the license 108856SN/A * terms below provided that you ensure that this notice is replicated 118856SN/A * unmodified and in its entirety in all distributions of the software, 128856SN/A * modified or unmodified, in source code or in binary form. 138856SN/A * 142914SN/A * Copyright (c) 2006 The Regents of The University of Michigan 152914SN/A * All rights reserved. 162914SN/A * 172914SN/A * Redistribution and use in source and binary forms, with or without 182914SN/A * modification, are permitted provided that the following conditions are 192914SN/A * met: redistributions of source code must retain the above copyright 202914SN/A * notice, this list of conditions and the following disclaimer; 212914SN/A * redistributions in binary form must reproduce the above copyright 222914SN/A * notice, this list of conditions and the following disclaimer in the 232914SN/A * documentation and/or other materials provided with the distribution; 242914SN/A * neither the name of the copyright holders nor the names of its 252914SN/A * contributors may be used to endorse or promote products derived from 262914SN/A * this software without specific prior written permission. 272914SN/A * 282914SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 292914SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 302914SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 312914SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 322914SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 332914SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 342914SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 352914SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 362914SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 372914SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 382914SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 392914SN/A * 402914SN/A * Authors: Ali Saidi 418856SN/A * Andreas Hansson 422914SN/A */ 432914SN/A 449356Snilay@cs.wisc.edu#include "mem/packet_queue.hh" 459152Satgutier@umich.edu 468914Sandreas.hansson@arm.com#include "base/trace.hh" 478914Sandreas.hansson@arm.com#include "debug/Drain.hh" 482914SN/A#include "debug/PacketQueue.hh" 495740SN/A 505740SN/APacketQueue::PacketQueue(EventManager& _em, const std::string& _label, 518975Sandreas.hansson@arm.com const std::string& _sendEventName, 529342SAndreas.Sandberg@arm.com bool force_order, 535740SN/A bool disable_sanity_check) 545740SN/A : em(_em), sendEvent([this]{ processSendEvent(); }, _sendEventName), 555740SN/A _disableSanityCheck(disable_sanity_check), 565740SN/A forceOrder(force_order), 578914Sandreas.hansson@arm.com label(_label), waitingOnRetry(false) 585740SN/A{ 595740SN/A} 605740SN/A 618914Sandreas.hansson@arm.comPacketQueue::~PacketQueue() 628914Sandreas.hansson@arm.com{ 638914Sandreas.hansson@arm.com} 648914Sandreas.hansson@arm.com 658914Sandreas.hansson@arm.comvoid 6610713Sandreas.hansson@arm.comPacketQueue::retry() 678914Sandreas.hansson@arm.com{ 688914Sandreas.hansson@arm.com DPRINTF(PacketQueue, "Queue %s received retry\n", name()); 698914Sandreas.hansson@arm.com assert(waitingOnRetry); 704929SN/A waitingOnRetry = false; 7110713Sandreas.hansson@arm.com sendDeferredPacket(); 7210713Sandreas.hansson@arm.com} 7310713Sandreas.hansson@arm.com 7410713Sandreas.hansson@arm.combool 7510713Sandreas.hansson@arm.comPacketQueue::hasAddr(Addr addr) const 7610713Sandreas.hansson@arm.com{ 7710713Sandreas.hansson@arm.com // caller is responsible for ensuring that all packets have the 7810713Sandreas.hansson@arm.com // same alignment 7910713Sandreas.hansson@arm.com for (const auto& p : transmitList) { 8010713Sandreas.hansson@arm.com if (p.pkt->getAddr() == addr) 8110713Sandreas.hansson@arm.com return true; 8210713Sandreas.hansson@arm.com } 838914Sandreas.hansson@arm.com return false; 843091SN/A} 858856SN/A 868856SN/Abool 8710322Sandreas.hansson@arm.comPacketQueue::trySatisfyFunctional(PacketPtr pkt) 888856SN/A{ 893296SN/A pkt->pushLabel(label); 9010322Sandreas.hansson@arm.com 918856SN/A auto i = transmitList.begin(); 928856SN/A bool found = false; 938856SN/A 948856SN/A while (!found && i != transmitList.end()) { 953284SN/A // If the buffered packet contains data, and it overlaps the 964929SN/A // current packet, then update data 978856SN/A found = pkt->trySatisfyFunctional(i->pkt); 988856SN/A ++i; 998856SN/A } 1004490SN/A 1013342SN/A pkt->popLabel(); 1024490SN/A 10310713Sandreas.hansson@arm.com return found; 1043403SN/A} 1059663Suri.wiener@arm.com 1069663Suri.wiener@arm.comvoid 10710713Sandreas.hansson@arm.comPacketQueue::schedSendTiming(PacketPtr pkt, Tick when) 1089160Sandreas.hansson@arm.com{ 1099160Sandreas.hansson@arm.com DPRINTF(PacketQueue, "%s for %s address %x size %d when %lu ord: %i\n", 1104492SN/A __func__, pkt->cmdString(), pkt->getAddr(), pkt->getSize(), when, 1119163Sandreas.hansson@arm.com forceOrder); 1129163Sandreas.hansson@arm.com 1139163Sandreas.hansson@arm.com // we can still send a packet before the end of this tick 1149390Sandreas.hansson@arm.com assert(when >= curTick()); 1159390Sandreas.hansson@arm.com 1169390Sandreas.hansson@arm.com // express snoops should never be queued 1179390Sandreas.hansson@arm.com assert(!pkt->isExpressSnoop()); 1189390Sandreas.hansson@arm.com 1199390Sandreas.hansson@arm.com // add a very basic sanity check on the port to ensure the 1209390Sandreas.hansson@arm.com // invisible buffer is not growing beyond reasonable limits 1218914Sandreas.hansson@arm.com if (!_disableSanityCheck && transmitList.size() > 100) { 1228914Sandreas.hansson@arm.com panic("Packet queue %s has grown beyond 100 packets\n", 1234666SN/A name()); 1248914Sandreas.hansson@arm.com } 1258914Sandreas.hansson@arm.com 1268914Sandreas.hansson@arm.com // nothing on the list 12710713Sandreas.hansson@arm.com if (transmitList.empty()) { 1284666SN/A transmitList.emplace_front(when, pkt); 1294666SN/A schedSendEvent(when); 1304666SN/A return; 1314666SN/A } 13210713Sandreas.hansson@arm.com 13310713Sandreas.hansson@arm.com // we should either have an outstanding retry, or a send event 13410713Sandreas.hansson@arm.com // scheduled, but there is an unfortunate corner case where the 13510713Sandreas.hansson@arm.com // x86 page-table walker and timing CPU send out a new request as 13610713Sandreas.hansson@arm.com // part of the receiving of a response (called by 13710713Sandreas.hansson@arm.com // PacketQueue::sendDeferredPacket), in which we end up calling 13810713Sandreas.hansson@arm.com // ourselves again before we had a chance to update waitingOnRetry 13910713Sandreas.hansson@arm.com // assert(waitingOnRetry || sendEvent.scheduled()); 1408914Sandreas.hansson@arm.com 1414666SN/A // this belongs in the middle somewhere, so search from the end to 14210713Sandreas.hansson@arm.com // order by tick; however, if forceOrder is set, also make sure 1433450SN/A // not to re-order in front of some existing packet with the same 1443403SN/A // address 1453450SN/A auto i = transmitList.end(); 1468914Sandreas.hansson@arm.com --i; 14710322Sandreas.hansson@arm.com while (i != transmitList.begin() && when < i->tick && 1488914Sandreas.hansson@arm.com !(forceOrder && i->pkt->getAddr() == pkt->getAddr())) 1498914Sandreas.hansson@arm.com --i; 1508914Sandreas.hansson@arm.com 15110713Sandreas.hansson@arm.com // emplace inserts the element before the position pointed to by 1528856SN/A // the iterator, so advance it one step 1538856SN/A transmitList.emplace(++i, when, pkt); 1548856SN/A} 15510713Sandreas.hansson@arm.com 1568856SN/Avoid 15710713Sandreas.hansson@arm.comPacketQueue::schedSendEvent(Tick when) 15810713Sandreas.hansson@arm.com{ 15910713Sandreas.hansson@arm.com // if we are waiting on a retry just hold off 16010713Sandreas.hansson@arm.com if (waitingOnRetry) { 16110713Sandreas.hansson@arm.com DPRINTF(PacketQueue, "Not scheduling send as waiting for retry\n"); 16210713Sandreas.hansson@arm.com assert(!sendEvent.scheduled()); 1638914Sandreas.hansson@arm.com return; 16410713Sandreas.hansson@arm.com } 16510713Sandreas.hansson@arm.com 16610713Sandreas.hansson@arm.com if (when != MaxTick) { 16710713Sandreas.hansson@arm.com // we cannot go back in time, and to be consistent we stick to 16810713Sandreas.hansson@arm.com // one tick in the future 16910713Sandreas.hansson@arm.com when = std::max(when, curTick() + 1); 17010423Sandreas.hansson@arm.com // @todo Revisit the +1 17110713Sandreas.hansson@arm.com 17210713Sandreas.hansson@arm.com if (!sendEvent.scheduled()) { 17310423Sandreas.hansson@arm.com em.schedule(&sendEvent, when); 17410423Sandreas.hansson@arm.com } else if (when < sendEvent.when()) { 17510713Sandreas.hansson@arm.com // if the new time is earlier than when the event 17610423Sandreas.hansson@arm.com // currently is scheduled, move it forward 1778856SN/A em.reschedule(&sendEvent, when); 17810713Sandreas.hansson@arm.com } 17910713Sandreas.hansson@arm.com } else { 1809342SAndreas.Sandberg@arm.com // we get a MaxTick when there is no more to send, so if we're 1819152Satgutier@umich.edu // draining, we may be done at this point 1829152Satgutier@umich.edu if (drainState() == DrainState::Draining && 1839342SAndreas.Sandberg@arm.com transmitList.empty() && !sendEvent.scheduled()) { 1849342SAndreas.Sandberg@arm.com 1858856SN/A DPRINTF(Drain, "PacketQueue done draining," 1868856SN/A "processing drain event\n"); 1878856SN/A signalDrainDone(); 1884492SN/A } 1893403SN/A } 1908914Sandreas.hansson@arm.com} 1912914SN/A 19210713Sandreas.hansson@arm.comvoid 19310713Sandreas.hansson@arm.comPacketQueue::sendDeferredPacket() 19410713Sandreas.hansson@arm.com{ 19510713Sandreas.hansson@arm.com // sanity checks 19610713Sandreas.hansson@arm.com assert(!waitingOnRetry); 19710713Sandreas.hansson@arm.com assert(deferredPacketReady()); 19810713Sandreas.hansson@arm.com 19910713Sandreas.hansson@arm.com DeferredPacket dp = transmitList.front(); 20010713Sandreas.hansson@arm.com 20110713Sandreas.hansson@arm.com // take the packet of the list before sending it, as sending of 20210713Sandreas.hansson@arm.com // the packet in some cases causes a new packet to be enqueued 20310713Sandreas.hansson@arm.com // (most notaly when responding to the timing CPU, leading to a 20410713Sandreas.hansson@arm.com // new request hitting in the L1 icache, leading to a new 20510713Sandreas.hansson@arm.com // response) 20610713Sandreas.hansson@arm.com transmitList.pop_front(); 20710713Sandreas.hansson@arm.com 2084492SN/A // use the appropriate implementation of sendTiming based on the 2098856SN/A // type of queue 2108856SN/A waitingOnRetry = !sendTiming(dp.pkt); 2118856SN/A 21210713Sandreas.hansson@arm.com // if we succeeded and are not waiting for a retry, schedule the 21310713Sandreas.hansson@arm.com // next send 21410713Sandreas.hansson@arm.com if (!waitingOnRetry) { 21510713Sandreas.hansson@arm.com schedSendEvent(deferredPacketReadyTime()); 2164492SN/A } else { 2174492SN/A // put the packet back at the front of the list 2184492SN/A transmitList.emplace_front(dp); 2194492SN/A } 2208914Sandreas.hansson@arm.com} 2214492SN/A 2224492SN/Avoid 2234492SN/APacketQueue::processSendEvent() 2242914SN/A{ 2252914SN/A assert(!waitingOnRetry); 2262914SN/A sendDeferredPacket(); 2279342SAndreas.Sandberg@arm.com} 2282914SN/A 22910322Sandreas.hansson@arm.comDrainState 2302914SN/APacketQueue::drain() 2319152Satgutier@umich.edu{ 2329342SAndreas.Sandberg@arm.com if (transmitList.empty()) { 2332914SN/A return DrainState::Drained; 2342914SN/A } else { 2358975Sandreas.hansson@arm.com DPRINTF(Drain, "PacketQueue not drained\n"); 23610713Sandreas.hansson@arm.com return DrainState::Draining; 23710713Sandreas.hansson@arm.com } 2388975Sandreas.hansson@arm.com} 2398975Sandreas.hansson@arm.com 2408975Sandreas.hansson@arm.comReqPacketQueue::ReqPacketQueue(EventManager& _em, MasterPort& _masterPort, 2418975Sandreas.hansson@arm.com const std::string _label) 2428975Sandreas.hansson@arm.com : PacketQueue(_em, _label, name(_masterPort, _label)), 24310713Sandreas.hansson@arm.com masterPort(_masterPort) 2448975Sandreas.hansson@arm.com{ 24510713Sandreas.hansson@arm.com} 2468975Sandreas.hansson@arm.com 2478975Sandreas.hansson@arm.combool 24810713Sandreas.hansson@arm.comReqPacketQueue::sendTiming(PacketPtr pkt) 24910713Sandreas.hansson@arm.com{ 25010713Sandreas.hansson@arm.com return masterPort.sendTimingReq(pkt); 25110713Sandreas.hansson@arm.com} 25210713Sandreas.hansson@arm.com 25310713Sandreas.hansson@arm.comSnoopRespPacketQueue::SnoopRespPacketQueue(EventManager& _em, 25410713Sandreas.hansson@arm.com MasterPort& _masterPort, 25510713Sandreas.hansson@arm.com bool force_order, 25610713Sandreas.hansson@arm.com const std::string _label) 25710713Sandreas.hansson@arm.com : PacketQueue(_em, _label, name(_masterPort, _label), force_order), 25810713Sandreas.hansson@arm.com masterPort(_masterPort) 25910713Sandreas.hansson@arm.com{ 26010713Sandreas.hansson@arm.com} 26110713Sandreas.hansson@arm.com 26210713Sandreas.hansson@arm.combool 2638975Sandreas.hansson@arm.comSnoopRespPacketQueue::sendTiming(PacketPtr pkt) 2648975Sandreas.hansson@arm.com{ 2658975Sandreas.hansson@arm.com return masterPort.sendTimingSnoopResp(pkt); 2668975Sandreas.hansson@arm.com} 2678975Sandreas.hansson@arm.com 26810713Sandreas.hansson@arm.comRespPacketQueue::RespPacketQueue(EventManager& _em, SlavePort& _slavePort, 2698975Sandreas.hansson@arm.com bool force_order, 2708975Sandreas.hansson@arm.com const std::string _label) 2718975Sandreas.hansson@arm.com : PacketQueue(_em, _label, name(_slavePort, _label), force_order), 272 slavePort(_slavePort) 273{ 274} 275 276bool 277RespPacketQueue::sendTiming(PacketPtr pkt) 278{ 279 return slavePort.sendTimingResp(pkt); 280} 281