packet_queue.cc revision 9160
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 449152Satgutier@umich.edu#include "debug/Drain.hh" 458914Sandreas.hansson@arm.com#include "debug/PacketQueue.hh" 468914Sandreas.hansson@arm.com#include "mem/packet_queue.hh" 472914SN/A 485740SN/Ausing namespace std; 495740SN/A 508975Sandreas.hansson@arm.comPacketQueue::PacketQueue(EventManager& _em, const std::string& _label) 518975Sandreas.hansson@arm.com : em(_em), sendEvent(this), drainEvent(NULL), label(_label), 525740SN/A waitingOnRetry(false) 535740SN/A{ 545740SN/A} 555740SN/A 568914Sandreas.hansson@arm.comPacketQueue::~PacketQueue() 575740SN/A{ 585740SN/A} 595740SN/A 608914Sandreas.hansson@arm.comvoid 618914Sandreas.hansson@arm.comPacketQueue::retry() 628914Sandreas.hansson@arm.com{ 638914Sandreas.hansson@arm.com DPRINTF(PacketQueue, "Queue %s received retry\n", name()); 648914Sandreas.hansson@arm.com assert(waitingOnRetry); 658914Sandreas.hansson@arm.com sendDeferredPacket(); 668914Sandreas.hansson@arm.com} 678914Sandreas.hansson@arm.com 684929SN/Abool 698914Sandreas.hansson@arm.comPacketQueue::checkFunctional(PacketPtr pkt) 703091SN/A{ 718856SN/A pkt->pushLabel(label); 728856SN/A 734490SN/A DeferredPacketIterator i = transmitList.begin(); 744490SN/A DeferredPacketIterator end = transmitList.end(); 758856SN/A bool found = false; 763296SN/A 778856SN/A while (!found && i != end) { 788856SN/A // If the buffered packet contains data, and it overlaps the 798856SN/A // current packet, then update data 808856SN/A found = pkt->checkFunctional(i->pkt); 818856SN/A ++i; 823284SN/A } 834929SN/A 848856SN/A pkt->popLabel(); 858856SN/A 868856SN/A return found; 874490SN/A} 883342SN/A 894490SN/Avoid 908914Sandreas.hansson@arm.comPacketQueue::schedSendEvent(Tick when) 918708SN/A{ 928856SN/A // if we are waiting on a retry, do not schedule a send event, and 938856SN/A // instead rely on retry being called 948708SN/A if (waitingOnRetry) { 958856SN/A assert(!sendEvent.scheduled()); 968708SN/A return; 978708SN/A } 988708SN/A 998856SN/A if (!sendEvent.scheduled()) { 1008914Sandreas.hansson@arm.com em.schedule(&sendEvent, when); 1018856SN/A } else if (sendEvent.when() > when) { 1028914Sandreas.hansson@arm.com em.reschedule(&sendEvent, when); 1038708SN/A } 1048708SN/A} 1052914SN/A 1062914SN/Avoid 1078948Sandreas.hansson@arm.comPacketQueue::schedSendTiming(PacketPtr pkt, Tick when, bool send_as_snoop) 1083403SN/A{ 1099160Sandreas.hansson@arm.com // we can still send a packet before the end of this tick 1109160Sandreas.hansson@arm.com assert(when >= curTick()); 1114492SN/A 1128914Sandreas.hansson@arm.com // nothing on the list, or earlier than current front element, 1138914Sandreas.hansson@arm.com // schedule an event 1144666SN/A if (transmitList.empty() || when < transmitList.front().tick) { 1158914Sandreas.hansson@arm.com // note that currently we ignore a potentially outstanding retry 1168914Sandreas.hansson@arm.com // and could in theory put a new packet at the head of the 1178914Sandreas.hansson@arm.com // transmit list before retrying the existing packet 1188948Sandreas.hansson@arm.com transmitList.push_front(DeferredPacket(when, pkt, send_as_snoop)); 1194666SN/A schedSendEvent(when); 1204666SN/A return; 1214666SN/A } 1224666SN/A 1238914Sandreas.hansson@arm.com // list is non-empty and this belongs at the end 1244666SN/A if (when >= transmitList.back().tick) { 1258948Sandreas.hansson@arm.com transmitList.push_back(DeferredPacket(when, pkt, send_as_snoop)); 1263450SN/A return; 1273403SN/A } 1283450SN/A 1298914Sandreas.hansson@arm.com // this belongs in the middle somewhere, insertion sort 1304490SN/A DeferredPacketIterator i = transmitList.begin(); 1318914Sandreas.hansson@arm.com ++i; // already checked for insertion at front 1328914Sandreas.hansson@arm.com while (i != transmitList.end() && when >= i->tick) 1338914Sandreas.hansson@arm.com ++i; 1348948Sandreas.hansson@arm.com transmitList.insert(i, DeferredPacket(when, pkt, send_as_snoop)); 1353403SN/A} 1363403SN/A 1378914Sandreas.hansson@arm.comvoid PacketQueue::trySendTiming() 1388856SN/A{ 1398856SN/A assert(deferredPacketReady()); 1408914Sandreas.hansson@arm.com 1418856SN/A // take the next packet off the list here, as we might return to 1428856SN/A // ourselves through the sendTiming call below 1438856SN/A DeferredPacket dp = transmitList.front(); 1448856SN/A transmitList.pop_front(); 1458856SN/A 1468975Sandreas.hansson@arm.com // use the appropriate implementation of sendTiming based on the 1478975Sandreas.hansson@arm.com // type of port associated with the queue, and whether the packet 1488975Sandreas.hansson@arm.com // is to be sent as a snoop or not 1498975Sandreas.hansson@arm.com waitingOnRetry = !sendTiming(dp.pkt, dp.sendAsSnoop); 1508856SN/A 1518856SN/A if (waitingOnRetry) { 1528856SN/A // put the packet back at the front of the list (packet should 1538856SN/A // not have changed since it wasn't accepted) 1548856SN/A assert(!sendEvent.scheduled()); 1558856SN/A transmitList.push_front(dp); 1568856SN/A } 1578856SN/A} 1588856SN/A 1598856SN/Avoid 1608914Sandreas.hansson@arm.comPacketQueue::scheduleSend(Tick time) 1618856SN/A{ 1628856SN/A // the next ready time is either determined by the next deferred packet, 1638856SN/A // or in the cache through the MSHR ready time 1648856SN/A Tick nextReady = std::min(deferredPacketReadyTime(), time); 1658914Sandreas.hansson@arm.com 1668856SN/A if (nextReady != MaxTick) { 1678856SN/A // if the sendTiming caused someone else to call our 1688856SN/A // recvTiming we could already have an event scheduled, check 1698856SN/A if (!sendEvent.scheduled()) 1708914Sandreas.hansson@arm.com em.schedule(&sendEvent, std::max(nextReady, curTick() + 1)); 1718856SN/A } else { 1728856SN/A // no more to send, so if we're draining, we may be done 1739152Satgutier@umich.edu if (drainEvent && transmitList.empty() && !sendEvent.scheduled()) { 1749152Satgutier@umich.edu DPRINTF(Drain, "PacketQueue done draining," 1759152Satgutier@umich.edu "processing drain event\n"); 1768856SN/A drainEvent->process(); 1778856SN/A drainEvent = NULL; 1788856SN/A } 1798856SN/A } 1808856SN/A} 1814492SN/A 1823403SN/Avoid 1838914Sandreas.hansson@arm.comPacketQueue::sendDeferredPacket() 1842914SN/A{ 1858914Sandreas.hansson@arm.com // try to send what is on the list, this will set waitingOnRetry 1868914Sandreas.hansson@arm.com // accordingly 1878856SN/A trySendTiming(); 1884492SN/A 1898856SN/A // if we succeeded and are not waiting for a retry, schedule the 1908856SN/A // next send 1918856SN/A if (!waitingOnRetry) { 1928856SN/A scheduleSend(); 1934492SN/A } 1944492SN/A} 1954492SN/A 1964492SN/Avoid 1978914Sandreas.hansson@arm.comPacketQueue::processSendEvent() 1984492SN/A{ 1994492SN/A assert(!waitingOnRetry); 2004492SN/A sendDeferredPacket(); 2012914SN/A} 2022914SN/A 2032914SN/Aunsigned int 2048914Sandreas.hansson@arm.comPacketQueue::drain(Event *de) 2052914SN/A{ 2068856SN/A if (transmitList.empty() && !sendEvent.scheduled()) 2072914SN/A return 0; 2089152Satgutier@umich.edu DPRINTF(Drain, "PacketQueue not drained\n"); 2092914SN/A drainEvent = de; 2102914SN/A return 1; 2112914SN/A} 2128975Sandreas.hansson@arm.com 2138975Sandreas.hansson@arm.comMasterPacketQueue::MasterPacketQueue(EventManager& _em, MasterPort& _masterPort, 2148975Sandreas.hansson@arm.com const std::string _label) 2158975Sandreas.hansson@arm.com : PacketQueue(_em, _label), masterPort(_masterPort) 2168975Sandreas.hansson@arm.com{ 2178975Sandreas.hansson@arm.com} 2188975Sandreas.hansson@arm.com 2198975Sandreas.hansson@arm.combool 2208975Sandreas.hansson@arm.comMasterPacketQueue::sendTiming(PacketPtr pkt, bool send_as_snoop) 2218975Sandreas.hansson@arm.com{ 2228975Sandreas.hansson@arm.com // attempt to send the packet and return according to the outcome 2238975Sandreas.hansson@arm.com if (!send_as_snoop) 2248975Sandreas.hansson@arm.com return masterPort.sendTimingReq(pkt); 2258975Sandreas.hansson@arm.com else 2268975Sandreas.hansson@arm.com return masterPort.sendTimingSnoopResp(pkt); 2278975Sandreas.hansson@arm.com} 2288975Sandreas.hansson@arm.com 2298975Sandreas.hansson@arm.comSlavePacketQueue::SlavePacketQueue(EventManager& _em, SlavePort& _slavePort, 2308975Sandreas.hansson@arm.com const std::string _label) 2318975Sandreas.hansson@arm.com : PacketQueue(_em, _label), slavePort(_slavePort) 2328975Sandreas.hansson@arm.com{ 2338975Sandreas.hansson@arm.com} 2348975Sandreas.hansson@arm.com 2358975Sandreas.hansson@arm.combool 2368975Sandreas.hansson@arm.comSlavePacketQueue::sendTiming(PacketPtr pkt, bool send_as_snoop) 2378975Sandreas.hansson@arm.com{ 2388975Sandreas.hansson@arm.com // we should never have queued snoop requests 2398975Sandreas.hansson@arm.com assert(!send_as_snoop); 2408975Sandreas.hansson@arm.com return slavePort.sendTimingResp(pkt); 2418975Sandreas.hansson@arm.com} 242