packet_queue.cc revision 9390
12914SN/A/* 28856SN/A * Copyright (c) 2012 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 "base/trace.hh" 459152Satgutier@umich.edu#include "debug/Drain.hh" 468914Sandreas.hansson@arm.com#include "debug/PacketQueue.hh" 478914Sandreas.hansson@arm.com#include "mem/packet_queue.hh" 482914SN/A 495740SN/Ausing namespace std; 505740SN/A 518975Sandreas.hansson@arm.comPacketQueue::PacketQueue(EventManager& _em, const std::string& _label) 529342SAndreas.Sandberg@arm.com : em(_em), sendEvent(this), drainManager(NULL), label(_label), 535740SN/A waitingOnRetry(false) 545740SN/A{ 555740SN/A} 565740SN/A 578914Sandreas.hansson@arm.comPacketQueue::~PacketQueue() 585740SN/A{ 595740SN/A} 605740SN/A 618914Sandreas.hansson@arm.comvoid 628914Sandreas.hansson@arm.comPacketQueue::retry() 638914Sandreas.hansson@arm.com{ 648914Sandreas.hansson@arm.com DPRINTF(PacketQueue, "Queue %s received retry\n", name()); 658914Sandreas.hansson@arm.com assert(waitingOnRetry); 668914Sandreas.hansson@arm.com sendDeferredPacket(); 678914Sandreas.hansson@arm.com} 688914Sandreas.hansson@arm.com 694929SN/Abool 708914Sandreas.hansson@arm.comPacketQueue::checkFunctional(PacketPtr pkt) 713091SN/A{ 728856SN/A pkt->pushLabel(label); 738856SN/A 744490SN/A DeferredPacketIterator i = transmitList.begin(); 754490SN/A DeferredPacketIterator end = transmitList.end(); 768856SN/A bool found = false; 773296SN/A 788856SN/A while (!found && i != end) { 798856SN/A // If the buffered packet contains data, and it overlaps the 808856SN/A // current packet, then update data 818856SN/A found = pkt->checkFunctional(i->pkt); 828856SN/A ++i; 833284SN/A } 844929SN/A 858856SN/A pkt->popLabel(); 868856SN/A 878856SN/A return found; 884490SN/A} 893342SN/A 904490SN/Avoid 918914Sandreas.hansson@arm.comPacketQueue::schedSendEvent(Tick when) 928708SN/A{ 938856SN/A // if we are waiting on a retry, do not schedule a send event, and 948856SN/A // instead rely on retry being called 958708SN/A if (waitingOnRetry) { 968856SN/A assert(!sendEvent.scheduled()); 978708SN/A return; 988708SN/A } 998708SN/A 1008856SN/A if (!sendEvent.scheduled()) { 1018914Sandreas.hansson@arm.com em.schedule(&sendEvent, when); 1028856SN/A } else if (sendEvent.when() > when) { 1038914Sandreas.hansson@arm.com em.reschedule(&sendEvent, when); 1048708SN/A } 1058708SN/A} 1062914SN/A 1072914SN/Avoid 1088948Sandreas.hansson@arm.comPacketQueue::schedSendTiming(PacketPtr pkt, Tick when, bool send_as_snoop) 1093403SN/A{ 1109160Sandreas.hansson@arm.com // we can still send a packet before the end of this tick 1119160Sandreas.hansson@arm.com assert(when >= curTick()); 1124492SN/A 1139163Sandreas.hansson@arm.com // express snoops should never be queued 1149163Sandreas.hansson@arm.com assert(!pkt->isExpressSnoop()); 1159163Sandreas.hansson@arm.com 1169390Sandreas.hansson@arm.com // add a very basic sanity check on the port to ensure the 1179390Sandreas.hansson@arm.com // invisible buffer is not growing beyond reasonable limits 1189390Sandreas.hansson@arm.com if (transmitList.size() > 100) { 1199390Sandreas.hansson@arm.com panic("Packet queue %s has grown beyond 100 packets\n", 1209390Sandreas.hansson@arm.com name()); 1219390Sandreas.hansson@arm.com } 1229390Sandreas.hansson@arm.com 1238914Sandreas.hansson@arm.com // nothing on the list, or earlier than current front element, 1248914Sandreas.hansson@arm.com // schedule an event 1254666SN/A if (transmitList.empty() || when < transmitList.front().tick) { 1268914Sandreas.hansson@arm.com // note that currently we ignore a potentially outstanding retry 1278914Sandreas.hansson@arm.com // and could in theory put a new packet at the head of the 1288914Sandreas.hansson@arm.com // transmit list before retrying the existing packet 1298948Sandreas.hansson@arm.com transmitList.push_front(DeferredPacket(when, pkt, send_as_snoop)); 1304666SN/A schedSendEvent(when); 1314666SN/A return; 1324666SN/A } 1334666SN/A 1348914Sandreas.hansson@arm.com // list is non-empty and this belongs at the end 1354666SN/A if (when >= transmitList.back().tick) { 1368948Sandreas.hansson@arm.com transmitList.push_back(DeferredPacket(when, pkt, send_as_snoop)); 1373450SN/A return; 1383403SN/A } 1393450SN/A 1408914Sandreas.hansson@arm.com // this belongs in the middle somewhere, insertion sort 1414490SN/A DeferredPacketIterator i = transmitList.begin(); 1428914Sandreas.hansson@arm.com ++i; // already checked for insertion at front 1438914Sandreas.hansson@arm.com while (i != transmitList.end() && when >= i->tick) 1448914Sandreas.hansson@arm.com ++i; 1458948Sandreas.hansson@arm.com transmitList.insert(i, DeferredPacket(when, pkt, send_as_snoop)); 1463403SN/A} 1473403SN/A 1488914Sandreas.hansson@arm.comvoid PacketQueue::trySendTiming() 1498856SN/A{ 1508856SN/A assert(deferredPacketReady()); 1518914Sandreas.hansson@arm.com 1528856SN/A // take the next packet off the list here, as we might return to 1538856SN/A // ourselves through the sendTiming call below 1548856SN/A DeferredPacket dp = transmitList.front(); 1558856SN/A transmitList.pop_front(); 1568856SN/A 1578975Sandreas.hansson@arm.com // use the appropriate implementation of sendTiming based on the 1588975Sandreas.hansson@arm.com // type of port associated with the queue, and whether the packet 1598975Sandreas.hansson@arm.com // is to be sent as a snoop or not 1608975Sandreas.hansson@arm.com waitingOnRetry = !sendTiming(dp.pkt, dp.sendAsSnoop); 1618856SN/A 1628856SN/A if (waitingOnRetry) { 1638856SN/A // put the packet back at the front of the list (packet should 1648856SN/A // not have changed since it wasn't accepted) 1658856SN/A assert(!sendEvent.scheduled()); 1668856SN/A transmitList.push_front(dp); 1678856SN/A } 1688856SN/A} 1698856SN/A 1708856SN/Avoid 1718914Sandreas.hansson@arm.comPacketQueue::scheduleSend(Tick time) 1728856SN/A{ 1738856SN/A // the next ready time is either determined by the next deferred packet, 1748856SN/A // or in the cache through the MSHR ready time 1758856SN/A Tick nextReady = std::min(deferredPacketReadyTime(), time); 1768914Sandreas.hansson@arm.com 1778856SN/A if (nextReady != MaxTick) { 1788856SN/A // if the sendTiming caused someone else to call our 1798856SN/A // recvTiming we could already have an event scheduled, check 1808856SN/A if (!sendEvent.scheduled()) 1818914Sandreas.hansson@arm.com em.schedule(&sendEvent, std::max(nextReady, curTick() + 1)); 1828856SN/A } else { 1838856SN/A // no more to send, so if we're draining, we may be done 1849342SAndreas.Sandberg@arm.com if (drainManager && transmitList.empty() && !sendEvent.scheduled()) { 1859152Satgutier@umich.edu DPRINTF(Drain, "PacketQueue done draining," 1869152Satgutier@umich.edu "processing drain event\n"); 1879342SAndreas.Sandberg@arm.com drainManager->signalDrainDone(); 1889342SAndreas.Sandberg@arm.com drainManager = NULL; 1898856SN/A } 1908856SN/A } 1918856SN/A} 1924492SN/A 1933403SN/Avoid 1948914Sandreas.hansson@arm.comPacketQueue::sendDeferredPacket() 1952914SN/A{ 1968914Sandreas.hansson@arm.com // try to send what is on the list, this will set waitingOnRetry 1978914Sandreas.hansson@arm.com // accordingly 1988856SN/A trySendTiming(); 1994492SN/A 2008856SN/A // if we succeeded and are not waiting for a retry, schedule the 2018856SN/A // next send 2028856SN/A if (!waitingOnRetry) { 2038856SN/A scheduleSend(); 2044492SN/A } 2054492SN/A} 2064492SN/A 2074492SN/Avoid 2088914Sandreas.hansson@arm.comPacketQueue::processSendEvent() 2094492SN/A{ 2104492SN/A assert(!waitingOnRetry); 2114492SN/A sendDeferredPacket(); 2122914SN/A} 2132914SN/A 2142914SN/Aunsigned int 2159342SAndreas.Sandberg@arm.comPacketQueue::drain(DrainManager *dm) 2162914SN/A{ 2178856SN/A if (transmitList.empty() && !sendEvent.scheduled()) 2182914SN/A return 0; 2199152Satgutier@umich.edu DPRINTF(Drain, "PacketQueue not drained\n"); 2209342SAndreas.Sandberg@arm.com drainManager = dm; 2212914SN/A return 1; 2222914SN/A} 2238975Sandreas.hansson@arm.com 2248975Sandreas.hansson@arm.comMasterPacketQueue::MasterPacketQueue(EventManager& _em, MasterPort& _masterPort, 2258975Sandreas.hansson@arm.com const std::string _label) 2268975Sandreas.hansson@arm.com : PacketQueue(_em, _label), masterPort(_masterPort) 2278975Sandreas.hansson@arm.com{ 2288975Sandreas.hansson@arm.com} 2298975Sandreas.hansson@arm.com 2308975Sandreas.hansson@arm.combool 2318975Sandreas.hansson@arm.comMasterPacketQueue::sendTiming(PacketPtr pkt, bool send_as_snoop) 2328975Sandreas.hansson@arm.com{ 2338975Sandreas.hansson@arm.com // attempt to send the packet and return according to the outcome 2348975Sandreas.hansson@arm.com if (!send_as_snoop) 2358975Sandreas.hansson@arm.com return masterPort.sendTimingReq(pkt); 2368975Sandreas.hansson@arm.com else 2378975Sandreas.hansson@arm.com return masterPort.sendTimingSnoopResp(pkt); 2388975Sandreas.hansson@arm.com} 2398975Sandreas.hansson@arm.com 2408975Sandreas.hansson@arm.comSlavePacketQueue::SlavePacketQueue(EventManager& _em, SlavePort& _slavePort, 2418975Sandreas.hansson@arm.com const std::string _label) 2428975Sandreas.hansson@arm.com : PacketQueue(_em, _label), slavePort(_slavePort) 2438975Sandreas.hansson@arm.com{ 2448975Sandreas.hansson@arm.com} 2458975Sandreas.hansson@arm.com 2468975Sandreas.hansson@arm.combool 2478975Sandreas.hansson@arm.comSlavePacketQueue::sendTiming(PacketPtr pkt, bool send_as_snoop) 2488975Sandreas.hansson@arm.com{ 2498975Sandreas.hansson@arm.com // we should never have queued snoop requests 2508975Sandreas.hansson@arm.com assert(!send_as_snoop); 2518975Sandreas.hansson@arm.com return slavePort.sendTimingResp(pkt); 2528975Sandreas.hansson@arm.com} 253