etherlink.cc revision 11701
1/* 2 * Copyright (c) 2015 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Copyright (c) 2002-2005 The Regents of The University of Michigan 15 * All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions are 19 * met: redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer; 21 * redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution; 24 * neither the name of the copyright holders nor the names of its 25 * contributors may be used to endorse or promote products derived from 26 * this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 39 * 40 * Authors: Nathan Binkert 41 * Ron Dreslinski 42 */ 43 44/* @file 45 * Device module for modelling a fixed bandwidth full duplex ethernet link 46 */ 47 48#include "dev/net/etherlink.hh" 49 50#include <cmath> 51#include <deque> 52#include <string> 53#include <vector> 54 55#include "base/random.hh" 56#include "base/trace.hh" 57#include "debug/Ethernet.hh" 58#include "debug/EthernetData.hh" 59#include "dev/net/etherdump.hh" 60#include "dev/net/etherint.hh" 61#include "dev/net/etherpkt.hh" 62#include "params/EtherLink.hh" 63#include "sim/core.hh" 64#include "sim/serialize.hh" 65#include "sim/system.hh" 66 67using namespace std; 68 69EtherLink::EtherLink(const Params *p) 70 : EtherObject(p) 71{ 72 link[0] = new Link(name() + ".link0", this, 0, p->speed, 73 p->delay, p->delay_var, p->dump); 74 link[1] = new Link(name() + ".link1", this, 1, p->speed, 75 p->delay, p->delay_var, p->dump); 76 77 interface[0] = new Interface(name() + ".int0", link[0], link[1]); 78 interface[1] = new Interface(name() + ".int1", link[1], link[0]); 79} 80 81 82EtherLink::~EtherLink() 83{ 84 delete link[0]; 85 delete link[1]; 86 87 delete interface[0]; 88 delete interface[1]; 89} 90 91EtherInt* 92EtherLink::getEthPort(const std::string &if_name, int idx) 93{ 94 Interface *i; 95 if (if_name == "int0") 96 i = interface[0]; 97 else if (if_name == "int1") 98 i = interface[1]; 99 else 100 return NULL; 101 if (i->getPeer()) 102 panic("interface already connected to\n"); 103 104 return i; 105} 106 107 108EtherLink::Interface::Interface(const string &name, Link *tx, Link *rx) 109 : EtherInt(name), txlink(tx) 110{ 111 tx->setTxInt(this); 112 rx->setRxInt(this); 113} 114 115EtherLink::Link::Link(const string &name, EtherLink *p, int num, 116 double rate, Tick delay, Tick delay_var, EtherDump *d) 117 : objName(name), parent(p), number(num), txint(NULL), rxint(NULL), 118 ticksPerByte(rate), linkDelay(delay), delayVar(delay_var), dump(d), 119 doneEvent(this), txQueueEvent(this) 120{ } 121 122void 123EtherLink::serialize(CheckpointOut &cp) const 124{ 125 link[0]->serialize("link0", cp); 126 link[1]->serialize("link1", cp); 127} 128 129void 130EtherLink::unserialize(CheckpointIn &cp) 131{ 132 link[0]->unserialize("link0", cp); 133 link[1]->unserialize("link1", cp); 134} 135 136void 137EtherLink::Link::txComplete(EthPacketPtr packet) 138{ 139 DPRINTF(Ethernet, "packet received: len=%d\n", packet->length); 140 DDUMP(EthernetData, packet->data, packet->length); 141 rxint->sendPacket(packet); 142} 143 144void 145EtherLink::Link::txDone() 146{ 147 if (dump) 148 dump->dump(packet); 149 150 if (linkDelay > 0) { 151 DPRINTF(Ethernet, "packet delayed: delay=%d\n", linkDelay); 152 txQueue.emplace_back(std::make_pair(curTick() + linkDelay, packet)); 153 if (!txQueueEvent.scheduled()) 154 parent->schedule(txQueueEvent, txQueue.front().first); 155 } else { 156 assert(txQueue.empty()); 157 txComplete(packet); 158 } 159 160 packet = 0; 161 assert(!busy()); 162 163 txint->sendDone(); 164} 165 166void 167EtherLink::Link::processTxQueue() 168{ 169 auto cur(txQueue.front()); 170 txQueue.pop_front(); 171 172 // Schedule a new event to process the next packet in the queue. 173 if (!txQueue.empty()) { 174 auto next(txQueue.front()); 175 assert(next.first > curTick()); 176 parent->schedule(txQueueEvent, next.first); 177 } 178 179 assert(cur.first == curTick()); 180 txComplete(cur.second); 181} 182 183bool 184EtherLink::Link::transmit(EthPacketPtr pkt) 185{ 186 if (busy()) { 187 DPRINTF(Ethernet, "packet not sent, link busy\n"); 188 return false; 189 } 190 191 DPRINTF(Ethernet, "packet sent: len=%d\n", pkt->length); 192 DDUMP(EthernetData, pkt->data, pkt->length); 193 194 packet = pkt; 195 Tick delay = (Tick)ceil(((double)pkt->simLength * ticksPerByte) + 1.0); 196 if (delayVar != 0) 197 delay += random_mt.random<Tick>(0, delayVar); 198 199 DPRINTF(Ethernet, "scheduling packet: delay=%d, (rate=%f)\n", 200 delay, ticksPerByte); 201 parent->schedule(doneEvent, curTick() + delay); 202 203 return true; 204} 205 206void 207EtherLink::Link::serialize(const string &base, CheckpointOut &cp) const 208{ 209 bool packet_exists = packet != nullptr; 210 paramOut(cp, base + ".packet_exists", packet_exists); 211 if (packet_exists) 212 packet->serialize(base + ".packet", cp); 213 214 bool event_scheduled = doneEvent.scheduled(); 215 paramOut(cp, base + ".event_scheduled", event_scheduled); 216 if (event_scheduled) { 217 Tick event_time = doneEvent.when(); 218 paramOut(cp, base + ".event_time", event_time); 219 } 220 221 const size_t tx_queue_size(txQueue.size()); 222 paramOut(cp, base + ".tx_queue_size", tx_queue_size); 223 unsigned idx(0); 224 for (const auto &pe : txQueue) { 225 paramOut(cp, csprintf("%s.txQueue[%i].tick", base, idx), pe.first); 226 pe.second->serialize(csprintf("%s.txQueue[%i].packet", base, idx), cp); 227 228 ++idx; 229 } 230} 231 232void 233EtherLink::Link::unserialize(const string &base, CheckpointIn &cp) 234{ 235 bool packet_exists; 236 paramIn(cp, base + ".packet_exists", packet_exists); 237 if (packet_exists) { 238 packet = make_shared<EthPacketData>(); 239 packet->unserialize(base + ".packet", cp); 240 } 241 242 bool event_scheduled; 243 paramIn(cp, base + ".event_scheduled", event_scheduled); 244 if (event_scheduled) { 245 Tick event_time; 246 paramIn(cp, base + ".event_time", event_time); 247 parent->schedule(doneEvent, event_time); 248 } 249 250 size_t tx_queue_size; 251 if (optParamIn(cp, base + ".tx_queue_size", tx_queue_size)) { 252 for (size_t idx = 0; idx < tx_queue_size; ++idx) { 253 Tick tick; 254 EthPacketPtr delayed_packet = make_shared<EthPacketData>(); 255 256 paramIn(cp, csprintf("%s.txQueue[%i].tick", base, idx), tick); 257 delayed_packet->unserialize( 258 csprintf("%s.txQueue[%i].packet", base, idx), cp); 259 260 fatal_if(!txQueue.empty() && txQueue.back().first > tick, 261 "Invalid txQueue packet order in EtherLink!\n"); 262 txQueue.emplace_back(std::make_pair(tick, delayed_packet)); 263 } 264 265 if (!txQueue.empty()) 266 parent->schedule(txQueueEvent, txQueue.front().first); 267 } else { 268 // We can't reliably convert in-flight packets from old 269 // checkpoints. In fact, gem5 hasn't been able to load these 270 // packets for at least two years before the format change. 271 warn("Old-style EtherLink serialization format detected, " 272 "in-flight packets may have been dropped.\n"); 273 } 274} 275 276EtherLink * 277EtherLinkParams::create() 278{ 279 return new EtherLink(this); 280} 281