tport.cc revision 3403:92c08efc9d53
1/* 2 * Copyright (c) 2006 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Ali Saidi 29 */ 30 31#include "mem/tport.hh" 32 33void 34SimpleTimingPort::recvFunctional(PacketPtr pkt) 35{ 36 std::list<std::pair<Tick,PacketPtr> >::iterator i = transmitList.begin(); 37 std::list<std::pair<Tick,PacketPtr> >::iterator end = transmitList.end(); 38 bool done = false; 39 40 while (i != end && !done) { 41 PacketPtr target = i->second; 42 // If the target contains data, and it overlaps the 43 // probed request, need to update data 44 if (target->intersect(pkt)) 45 done = fixPacket(pkt, target); 46 47 } 48 49 //Then just do an atomic access and throw away the returned latency 50 if (pkt->result != Packet::Success) 51 recvAtomic(pkt); 52} 53 54bool 55SimpleTimingPort::recvTiming(PacketPtr pkt) 56{ 57 // If the device is only a slave, it should only be sending 58 // responses, which should never get nacked. There used to be 59 // code to hanldle nacks here, but I'm pretty sure it didn't work 60 // correctly with the drain code, so that would need to be fixed 61 // if we ever added it back. 62 assert(pkt->result != Packet::Nacked); 63 Tick latency = recvAtomic(pkt); 64 // turn packet around to go back to requester if response expected 65 if (pkt->needsResponse()) { 66 pkt->makeTimingResponse(); 67 sendTiming(pkt, latency); 68 } 69 else { 70 if (pkt->cmd != Packet::UpgradeReq) 71 { 72 delete pkt->req; 73 delete pkt; 74 } 75 } 76 return true; 77} 78 79void 80SimpleTimingPort::recvRetry() 81{ 82 assert(!transmitList.empty()); 83 if (Port::sendTiming(transmitList.front().second)) { 84 transmitList.pop_front(); 85 DPRINTF(Bus, "No Longer waiting on retry\n"); 86 if (!transmitList.empty()) { 87 Tick time = transmitList.front().first; 88 sendEvent.schedule(time <= curTick ? curTick+1 : time); 89 } 90 } 91 92 if (transmitList.empty() && drainEvent) { 93 drainEvent->process(); 94 drainEvent = NULL; 95 } 96} 97 98void 99SimpleTimingPort::sendTiming(PacketPtr pkt, Tick time) 100{ 101 if (transmitList.empty()) { 102 assert(!sendEvent.scheduled()); 103 sendEvent.schedule(curTick+time); 104 } 105 transmitList.push_back(std::pair<Tick,PacketPtr>(time+curTick,pkt)); 106} 107 108void 109SimpleTimingPort::SendEvent::process() 110{ 111 assert(port->transmitList.size()); 112 assert(port->transmitList.front().first <= curTick); 113 if (port->Port::sendTiming(port->transmitList.front().second)) { 114 //send successful, remove packet 115 port->transmitList.pop_front(); 116 if (!port->transmitList.empty()) { 117 Tick time = port->transmitList.front().first; 118 schedule(time <= curTick ? curTick+1 : time); 119 } 120 if (port->transmitList.empty() && port->drainEvent) { 121 port->drainEvent->process(); 122 port->drainEvent = NULL; 123 } 124 return; 125 } 126 // send unsuccessful (due to flow control). Will get retry 127 // callback later; save for then if not already 128 DPRINTF(Bus, "Waiting on retry\n"); 129} 130 131 132unsigned int 133SimpleTimingPort::drain(Event *de) 134{ 135 if (transmitList.size() == 0) 136 return 0; 137 drainEvent = de; 138 return 1; 139} 140