tport.cc revision 3091:dba513d68c16
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(Packet *pkt) 35{ 36 // just do an atomic access and throw away the returned latency 37 recvAtomic(pkt); 38} 39 40bool 41SimpleTimingPort::recvTiming(Packet *pkt) 42{ 43 // If the device is only a slave, it should only be sending 44 // responses, which should never get nacked. There used to be 45 // code to hanldle nacks here, but I'm pretty sure it didn't work 46 // correctly with the drain code, so that would need to be fixed 47 // if we ever added it back. 48 assert(pkt->result != Packet::Nacked); 49 Tick latency = recvAtomic(pkt); 50 // turn packet around to go back to requester 51 pkt->makeTimingResponse(); 52 sendTimingLater(pkt, latency); 53 return true; 54} 55 56void 57SimpleTimingPort::recvRetry() 58{ 59 bool result = true; 60 while (result && transmitList.size()) { 61 result = sendTiming(transmitList.front()); 62 if (result) 63 transmitList.pop_front(); 64 } 65 if (transmitList.size() == 0 && drainEvent) { 66 drainEvent->process(); 67 drainEvent = NULL; 68 } 69} 70 71void 72SimpleTimingPort::SendEvent::process() 73{ 74 port->outTiming--; 75 assert(port->outTiming >= 0); 76 if (port->sendTiming(packet)) { 77 // send successfule 78 if (port->transmitList.size() == 0 && port->drainEvent) { 79 port->drainEvent->process(); 80 port->drainEvent = NULL; 81 } 82 } else { 83 // send unsuccessful (due to flow control). Will get retry 84 // callback later; save for then. 85 port->transmitList.push_back(packet); 86 } 87} 88 89 90unsigned int 91SimpleTimingPort::drain(Event *de) 92{ 93 if (outTiming == 0 && transmitList.size() == 0) 94 return 0; 95 drainEvent = de; 96 return 1; 97} 98