packet_queue.cc revision 10713
12914SN/A/* 213564Snikos.nikoleris@arm.com * Copyright (c) 2012,2015 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 4411793Sbrandon.potter@amd.com#include "base/trace.hh" 4511793Sbrandon.potter@amd.com#include "debug/Drain.hh" 469356Snilay@cs.wisc.edu#include "debug/PacketQueue.hh" 479152Satgutier@umich.edu#include "mem/packet_queue.hh" 488914Sandreas.hansson@arm.com 492914SN/Ausing namespace std; 5011207SBrad.Beckmann@amd.com 5112083Sspwilson2@wisc.eduPacketQueue::PacketQueue(EventManager& _em, const std::string& _label) 5213564Snikos.nikoleris@arm.com : em(_em), sendEvent(this), drainManager(NULL), label(_label), 5311207SBrad.Beckmann@amd.com waitingOnRetry(false) 5412083Sspwilson2@wisc.edu{ 5512083Sspwilson2@wisc.edu} 5613564Snikos.nikoleris@arm.com 5711207SBrad.Beckmann@amd.comPacketQueue::~PacketQueue() 585740SN/A{ 595740SN/A} 605740SN/A 618914Sandreas.hansson@arm.comvoid 625740SN/APacketQueue::retry() 635740SN/A{ 645740SN/A DPRINTF(PacketQueue, "Queue %s received retry\n", name()); 658914Sandreas.hansson@arm.com assert(waitingOnRetry); 668914Sandreas.hansson@arm.com waitingOnRetry = false; 678914Sandreas.hansson@arm.com sendDeferredPacket(); 688914Sandreas.hansson@arm.com} 698914Sandreas.hansson@arm.com 7010713Sandreas.hansson@arm.combool 718914Sandreas.hansson@arm.comPacketQueue::hasAddr(Addr addr) const 728914Sandreas.hansson@arm.com{ 738914Sandreas.hansson@arm.com // caller is responsible for ensuring that all packets have the 744929SN/A // same alignment 7510713Sandreas.hansson@arm.com for (const auto& p : transmitList) { 7610713Sandreas.hansson@arm.com if (p.pkt->getAddr() == addr) 7710713Sandreas.hansson@arm.com return true; 7810713Sandreas.hansson@arm.com } 7910713Sandreas.hansson@arm.com return false; 8010713Sandreas.hansson@arm.com} 8110713Sandreas.hansson@arm.com 8210713Sandreas.hansson@arm.combool 8310713Sandreas.hansson@arm.comPacketQueue::checkFunctional(PacketPtr pkt) 8410713Sandreas.hansson@arm.com{ 8510713Sandreas.hansson@arm.com pkt->pushLabel(label); 8610713Sandreas.hansson@arm.com 8712823Srmk35@cl.cam.ac.uk auto i = transmitList.begin(); 883091SN/A bool found = false; 898856SN/A 908856SN/A while (!found && i != transmitList.end()) { 9110322Sandreas.hansson@arm.com // If the buffered packet contains data, and it overlaps the 928856SN/A // current packet, then update data 933296SN/A found = pkt->checkFunctional(i->pkt); 9410322Sandreas.hansson@arm.com ++i; 958856SN/A } 968856SN/A 9712823Srmk35@cl.cam.ac.uk pkt->popLabel(); 988856SN/A 993284SN/A return found; 1004929SN/A} 1018856SN/A 1028856SN/Avoid 1038856SN/APacketQueue::schedSendTiming(PacketPtr pkt, Tick when) 1044490SN/A{ 1053342SN/A DPRINTF(PacketQueue, "%s for %s address %x size %d\n", __func__, 1064490SN/A pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 10713564Snikos.nikoleris@arm.com 1083403SN/A // we can still send a packet before the end of this tick 10910722Sstephan.diestelhorst@arm.com assert(when >= curTick()); 11010722Sstephan.diestelhorst@arm.com 11113564Snikos.nikoleris@arm.com // express snoops should never be queued 11210713Sandreas.hansson@arm.com assert(!pkt->isExpressSnoop()); 1139160Sandreas.hansson@arm.com 1149160Sandreas.hansson@arm.com // add a very basic sanity check on the port to ensure the 1154492SN/A // invisible buffer is not growing beyond reasonable limits 1169163Sandreas.hansson@arm.com if (transmitList.size() > 100) { 1179163Sandreas.hansson@arm.com panic("Packet queue %s has grown beyond 100 packets\n", 1189163Sandreas.hansson@arm.com name()); 1199390Sandreas.hansson@arm.com } 1209390Sandreas.hansson@arm.com 12111207SBrad.Beckmann@amd.com // nothing on the list, or earlier than current front element, 1229390Sandreas.hansson@arm.com // schedule an event 1239390Sandreas.hansson@arm.com if (transmitList.empty() || when < transmitList.front().tick) { 1249390Sandreas.hansson@arm.com // note that currently we ignore a potentially outstanding retry 1259390Sandreas.hansson@arm.com // and could in theory put a new packet at the head of the 12611195Sandreas.hansson@arm.com // transmit list before retrying the existing packet 12711195Sandreas.hansson@arm.com transmitList.push_front(DeferredPacket(when, pkt)); 12810922Sandreas.hansson@arm.com schedSendEvent(when); 1294666SN/A return; 1304666SN/A } 1314666SN/A 1324666SN/A // we should either have an outstanding retry, or a send event 13310713Sandreas.hansson@arm.com // scheduled, but there is an unfortunate corner case where the 13410713Sandreas.hansson@arm.com // x86 page-table walker and timing CPU send out a new request as 13510713Sandreas.hansson@arm.com // part of the receiving of a response (called by 13610713Sandreas.hansson@arm.com // PacketQueue::sendDeferredPacket), in which we end up calling 13710713Sandreas.hansson@arm.com // ourselves again before we had a chance to update waitingOnRetry 13810713Sandreas.hansson@arm.com // assert(waitingOnRetry || sendEvent.scheduled()); 13910713Sandreas.hansson@arm.com 14010713Sandreas.hansson@arm.com // list is non-empty and this belongs at the end 14111195Sandreas.hansson@arm.com if (when >= transmitList.back().tick) { 14213564Snikos.nikoleris@arm.com transmitList.push_back(DeferredPacket(when, pkt)); 14311195Sandreas.hansson@arm.com return; 14411195Sandreas.hansson@arm.com } 14511195Sandreas.hansson@arm.com 14611195Sandreas.hansson@arm.com // this belongs in the middle somewhere, insertion sort 14711195Sandreas.hansson@arm.com auto i = transmitList.begin(); 14813564Snikos.nikoleris@arm.com ++i; // already checked for insertion at front 14911195Sandreas.hansson@arm.com while (i != transmitList.end() && when >= i->tick) 1503450SN/A ++i; 15111195Sandreas.hansson@arm.com transmitList.insert(i, DeferredPacket(when, pkt)); 15211195Sandreas.hansson@arm.com} 15311195Sandreas.hansson@arm.com 1548856SN/Avoid 1558856SN/APacketQueue::schedSendEvent(Tick when) 1568856SN/A{ 15710713Sandreas.hansson@arm.com // if we are waiting on a retry just hold off 1588856SN/A if (waitingOnRetry) { 15910713Sandreas.hansson@arm.com DPRINTF(PacketQueue, "Not scheduling send as waiting for retry\n"); 16010713Sandreas.hansson@arm.com assert(!sendEvent.scheduled()); 16110713Sandreas.hansson@arm.com return; 16210713Sandreas.hansson@arm.com } 16310713Sandreas.hansson@arm.com 16410713Sandreas.hansson@arm.com if (when != MaxTick) { 1658914Sandreas.hansson@arm.com // we cannot go back in time, and to be consistent we stick to 16610713Sandreas.hansson@arm.com // one tick in the future 16710713Sandreas.hansson@arm.com when = std::max(when, curTick() + 1); 16810713Sandreas.hansson@arm.com // @todo Revisit the +1 16910713Sandreas.hansson@arm.com 17010713Sandreas.hansson@arm.com if (!sendEvent.scheduled()) { 17110713Sandreas.hansson@arm.com em.schedule(&sendEvent, when); 17210423Sandreas.hansson@arm.com } else if (when < sendEvent.when()) { 17310713Sandreas.hansson@arm.com // if the new time is earlier than when the event 17410713Sandreas.hansson@arm.com // currently is scheduled, move it forward 17510423Sandreas.hansson@arm.com em.reschedule(&sendEvent, when); 17610423Sandreas.hansson@arm.com } 17710713Sandreas.hansson@arm.com } else { 17810423Sandreas.hansson@arm.com // we get a MaxTick when there is no more to send, so if we're 1798856SN/A // draining, we may be done at this point 18010713Sandreas.hansson@arm.com if (drainManager && transmitList.empty() && !sendEvent.scheduled()) { 18110713Sandreas.hansson@arm.com DPRINTF(Drain, "PacketQueue done draining," 18210913Sandreas.sandberg@arm.com "processing drain event\n"); 18310913Sandreas.sandberg@arm.com drainManager->signalDrainDone(); 18410913Sandreas.sandberg@arm.com drainManager = NULL; 1859152Satgutier@umich.edu } 1869152Satgutier@umich.edu } 18710913Sandreas.sandberg@arm.com} 1888856SN/A 1898856SN/Avoid 1908856SN/APacketQueue::sendDeferredPacket() 1914492SN/A{ 1923403SN/A // sanity checks 1938914Sandreas.hansson@arm.com assert(!waitingOnRetry); 1942914SN/A assert(deferredPacketReady()); 19510713Sandreas.hansson@arm.com 19610713Sandreas.hansson@arm.com DeferredPacket dp = transmitList.front(); 19710713Sandreas.hansson@arm.com 19810713Sandreas.hansson@arm.com // take the packet of the list before sending it, as sending of 19910713Sandreas.hansson@arm.com // the packet in some cases causes a new packet to be enqueued 20010713Sandreas.hansson@arm.com // (most notaly when responding to the timing CPU, leading to a 20110713Sandreas.hansson@arm.com // new request hitting in the L1 icache, leading to a new 20210713Sandreas.hansson@arm.com // response) 20310713Sandreas.hansson@arm.com transmitList.pop_front(); 20410713Sandreas.hansson@arm.com 20510713Sandreas.hansson@arm.com // use the appropriate implementation of sendTiming based on the 20610713Sandreas.hansson@arm.com // type of queue 20710713Sandreas.hansson@arm.com waitingOnRetry = !sendTiming(dp.pkt); 20810713Sandreas.hansson@arm.com 20910713Sandreas.hansson@arm.com // if we succeeded and are not waiting for a retry, schedule the 21010713Sandreas.hansson@arm.com // next send 2114492SN/A if (!waitingOnRetry) { 2128856SN/A schedSendEvent(deferredPacketReadyTime()); 2138856SN/A } else { 2148856SN/A // put the packet back at the front of the list 21510713Sandreas.hansson@arm.com transmitList.push_front(dp); 21610713Sandreas.hansson@arm.com } 21710713Sandreas.hansson@arm.com} 21810745Sandreas.hansson@arm.com 2194492SN/Avoid 2204492SN/APacketQueue::processSendEvent() 2214492SN/A{ 2224492SN/A assert(!waitingOnRetry); 2238914Sandreas.hansson@arm.com sendDeferredPacket(); 2244492SN/A} 2254492SN/A 2264492SN/Aunsigned int 2272914SN/APacketQueue::drain(DrainManager *dm) 2282914SN/A{ 22910913Sandreas.sandberg@arm.com if (transmitList.empty()) 23010913Sandreas.sandberg@arm.com return 0; 2312914SN/A DPRINTF(Drain, "PacketQueue not drained\n"); 23210913Sandreas.sandberg@arm.com drainManager = dm; 23310913Sandreas.sandberg@arm.com return 1; 23410913Sandreas.sandberg@arm.com} 23510913Sandreas.sandberg@arm.com 23610913Sandreas.sandberg@arm.comReqPacketQueue::ReqPacketQueue(EventManager& _em, MasterPort& _masterPort, 23710913Sandreas.sandberg@arm.com const std::string _label) 2382914SN/A : PacketQueue(_em, _label), masterPort(_masterPort) 2398975Sandreas.hansson@arm.com{ 24010713Sandreas.hansson@arm.com} 24110713Sandreas.hansson@arm.com 24212083Sspwilson2@wisc.edubool 24312083Sspwilson2@wisc.eduReqPacketQueue::sendTiming(PacketPtr pkt) 2448975Sandreas.hansson@arm.com{ 2458975Sandreas.hansson@arm.com return masterPort.sendTimingReq(pkt); 2468975Sandreas.hansson@arm.com} 2478975Sandreas.hansson@arm.com 24810713Sandreas.hansson@arm.comSnoopRespPacketQueue::SnoopRespPacketQueue(EventManager& _em, 2498975Sandreas.hansson@arm.com MasterPort& _masterPort, 25010713Sandreas.hansson@arm.com const std::string _label) 2518975Sandreas.hansson@arm.com : PacketQueue(_em, _label), masterPort(_masterPort) 2528975Sandreas.hansson@arm.com{ 25310713Sandreas.hansson@arm.com} 25410713Sandreas.hansson@arm.com 25513564Snikos.nikoleris@arm.combool 25610713Sandreas.hansson@arm.comSnoopRespPacketQueue::sendTiming(PacketPtr pkt) 25713564Snikos.nikoleris@arm.com{ 25812083Sspwilson2@wisc.edu return masterPort.sendTimingSnoopResp(pkt); 25910713Sandreas.hansson@arm.com} 26010713Sandreas.hansson@arm.com 26110713Sandreas.hansson@arm.comRespPacketQueue::RespPacketQueue(EventManager& _em, SlavePort& _slavePort, 26210713Sandreas.hansson@arm.com const std::string _label) 26310713Sandreas.hansson@arm.com : PacketQueue(_em, _label), slavePort(_slavePort) 26410713Sandreas.hansson@arm.com{ 26510713Sandreas.hansson@arm.com} 26610713Sandreas.hansson@arm.com 26710713Sandreas.hansson@arm.combool 26810713Sandreas.hansson@arm.comRespPacketQueue::sendTiming(PacketPtr pkt) 26913564Snikos.nikoleris@arm.com{ 27010713Sandreas.hansson@arm.com return slavePort.sendTimingResp(pkt); 27113564Snikos.nikoleris@arm.com} 27212083Sspwilson2@wisc.edu