tport.cc revision 3284
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 //First check queued events 37 std::list<Packet *>::iterator i = transmitList.begin(); 38 std::list<Packet *>::iterator end = transmitList.end(); 39 for (; i != end; ++i) { 40 Packet * target = *i; 41 // If the target contains data, and it overlaps the 42 // probed request, need to update data 43 if (target->intersect(pkt)) { 44 uint8_t* pkt_data; 45 uint8_t* write_data; 46 int data_size; 47 if (target->getAddr() < pkt->getAddr()) { 48 int offset = pkt->getAddr() - target->getAddr(); 49 pkt_data = pkt->getPtr<uint8_t>(); 50 write_data = target->getPtr<uint8_t>() + offset; 51 data_size = target->getSize() - offset; 52 assert(data_size > 0); 53 if (data_size > pkt->getSize()) 54 data_size = pkt->getSize(); 55 } else { 56 int offset = target->getAddr() - pkt->getAddr(); 57 pkt_data = pkt->getPtr<uint8_t>() + offset; 58 write_data = target->getPtr<uint8_t>(); 59 data_size = pkt->getSize() - offset; 60 assert(data_size > pkt->getSize()); 61 if (data_size > target->getSize()) 62 data_size = target->getSize(); 63 } 64 65 if (pkt->isWrite()) { 66 memcpy(pkt_data, write_data, data_size); 67 } else { 68 memcpy(write_data, pkt_data, data_size); 69 } 70 } 71 } 72 //Then just do an atomic access and throw away the returned latency 73 recvAtomic(pkt); 74} 75 76bool 77SimpleTimingPort::recvTiming(Packet *pkt) 78{ 79 // If the device is only a slave, it should only be sending 80 // responses, which should never get nacked. There used to be 81 // code to hanldle nacks here, but I'm pretty sure it didn't work 82 // correctly with the drain code, so that would need to be fixed 83 // if we ever added it back. 84 assert(pkt->result != Packet::Nacked); 85 Tick latency = recvAtomic(pkt); 86 // turn packet around to go back to requester if response expected 87 if (pkt->needsResponse()) { 88 pkt->makeTimingResponse(); 89 sendTimingLater(pkt, latency); 90 } 91 return true; 92} 93 94void 95SimpleTimingPort::recvRetry() 96{ 97 assert(outTiming > 0); 98 assert(!transmitList.empty()); 99 if (sendTiming(transmitList.front())) { 100 transmitList.pop_front(); 101 outTiming--; 102 DPRINTF(Bus, "No Longer waiting on retry\n"); 103 if (!transmitList.empty()) 104 sendTimingLater(transmitList.front(), 1); 105 } 106 107 if (transmitList.empty() && drainEvent) { 108 drainEvent->process(); 109 drainEvent = NULL; 110 } 111} 112 113void 114SimpleTimingPort::SendEvent::process() 115{ 116 assert(port->outTiming > 0); 117 if (!port->transmitList.empty() && port->transmitList.front() != packet) { 118 //We are not the head of the list 119 port->transmitList.push_back(packet); 120 } else if (port->sendTiming(packet)) { 121 // send successful 122 if (port->transmitList.size()) { 123 port->transmitList.pop_front(); 124 port->outTiming--; 125 if (!port->transmitList.empty()) 126 port->sendTimingLater(port->transmitList.front(), 1); 127 } 128 if (port->transmitList.empty() && port->drainEvent) { 129 port->drainEvent->process(); 130 port->drainEvent = NULL; 131 } 132 } else { 133 // send unsuccessful (due to flow control). Will get retry 134 // callback later; save for then if not already 135 DPRINTF(Bus, "Waiting on retry\n"); 136 if (!(port->transmitList.front() == packet)) 137 port->transmitList.push_back(packet); 138 } 139} 140 141 142unsigned int 143SimpleTimingPort::drain(Event *de) 144{ 145 if (outTiming == 0 && transmitList.size() == 0) 146 return 0; 147 drainEvent = de; 148 return 1; 149} 150