1 2/* 3 * Copyright (c) 2006 The Regents of The University of Michigan 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are 8 * met: redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer; 10 * redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution; 13 * neither the name of the copyright holders nor the names of its 14 * contributors may be used to endorse or promote products derived from 15 * this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30/** 31 * @file Definition of a simple bus bridge without buffering. 32 */ 33
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34#include <algorithm> |
35 36#include "base/trace.hh" 37#include "mem/bridge.hh" 38#include "sim/builder.hh" 39
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40Bridge::BridgePort::BridgePort(const std::string &_name, 41 Bridge *_bridge, BridgePort *_otherPort, 42 int _delay, int _queueLimit) 43 : Port(_name), bridge(_bridge), otherPort(_otherPort), 44 delay(_delay), outstandingResponses(0), 45 queueLimit(_queueLimit), sendEvent(this) 46{ 47} 48 49Bridge::Bridge(const std::string &n, int qsa, int qsb, 50 Tick _delay, int write_ack) 51 : MemObject(n), 52 portA(n + "-portA", this, &portB, _delay, qsa), 53 portB(n + "-portB", this, &portA, _delay, qsa), 54 ackWrites(write_ack) 55{ 56} 57 58Port * 59Bridge::getPort(const std::string &if_name) 60{ 61 BridgePort *port; 62 63 if (if_name == "side_a") 64 port = &portA; 65 else if (if_name == "side_b") 66 port = &portB; 67 else 68 return NULL; 69 70 if (port->getPeer() != NULL) 71 panic("bridge side %s already connected to.", if_name); 72 return port; 73} 74 75 |
76void 77Bridge::init() 78{ 79 // Make sure that both sides are connected to.
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43 if (sideA == NULL || sideB == NULL)
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80 if (portA.getPeer() == NULL || portB.getPeer() == NULL) |
81 panic("Both ports of bus bridge are not connected to a bus.\n"); 82} 83 84
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48/** Function called by the port when the bus is recieving a Timing
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85/** Function called by the port when the bus is receiving a Timing |
86 * transaction.*/ 87bool
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51Bridge::recvTiming(Packet *pkt, Side id)
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88Bridge::BridgePort::recvTiming(Packet *pkt) |
89{
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53 if (blockedA && id == SideA)
54 return false;
55 if (blockedB && id == SideB)
56 return false;
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90 DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n", 91 pkt->getSrc(), pkt->getDest(), pkt->getAddr()); |
92
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58 if (delay) {
59 if (!sendEvent.scheduled())
60 sendEvent.schedule(curTick + delay);
61 if (id == SideA) {
62 inboundA.push_back(std::make_pair<Packet*, Tick>(pkt, curTick));
63 blockCheck(SideA);
64 } else {
65 inboundB.push_back(std::make_pair<Packet*, Tick>(pkt, curTick));
66 blockCheck(SideB);
67 }
68 } else {
69 if (id == SideB) {
70 sideA->sendPkt(pkt);
71 blockCheck(SideB);
72 } else {
73 sideB->sendPkt(pkt);
74 blockCheck(SideA);
75 }
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93 if (pkt->isResponse()) { 94 // This is a response for a request we forwarded earlier. The 95 // corresponding PacketBuffer should be stored in the packet's 96 // senderState field. 97 PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState); 98 assert(buf != NULL); 99 // set up new packet dest & senderState based on values saved 100 // from original request 101 buf->fixResponse(pkt); 102 DPRINTF(BusBridge, " is response, new dest %d\n", pkt->getDest()); 103 delete buf; |
104 }
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77 return true;
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105
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106 return otherPort->queueForSendTiming(pkt); |
107} 108
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81void
82Bridge::blockCheck(Side id)
83{
84 /* Check that we still have buffer space available. */
85 if (id == SideB) {
86 if (sideA->numQueued() + inboundB.size() >= queueSizeA && !blockedB) {
87 sideB->sendStatusChange(Port::Blocked);
88 blockedB = true;
89 } else if (sideA->numQueued() + inboundB.size() < queueSizeA && blockedB) {
90 sideB->sendStatusChange(Port::Unblocked);
91 blockedB = false;
92 }
93 } else {
94 if (sideB->numQueued() + inboundA.size() >= queueSizeB && !blockedA) {
95 sideA->sendStatusChange(Port::Blocked);
96 blockedA = true;
97 } else if (sideB->numQueued() + inboundA.size() < queueSizeB && blockedA) {
98 sideA->sendStatusChange(Port::Unblocked);
99 blockedA = false;
100 }
101 }
102}
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109
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104void Bridge::timerEvent()
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110bool 111Bridge::BridgePort::queueForSendTiming(Packet *pkt) |
112{
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106 Tick t = 0;
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113 if (queueFull()) 114 return false; |
115
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108 assert(inboundA.size() || inboundB.size());
109 if (inboundA.size()) {
110 while (inboundA.front().second <= curTick + delay){
111 sideB->sendPkt(inboundA.front());
112 inboundA.pop_front();
113 }
114 if (inboundA.size())
115 t = inboundA.front().second + delay;
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116 Tick readyTime = curTick + delay; 117 PacketBuffer *buf = new PacketBuffer(pkt, readyTime); 118 119 // If we're about to put this packet at the head of the queue, we 120 // need to schedule an event to do the transmit. Otherwise there 121 // should already be an event scheduled for sending the head 122 // packet. 123 if (sendQueue.empty()) { 124 sendEvent.schedule(readyTime); |
125 }
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117 if (inboundB.size()) {
118 while (inboundB.front().second <= curTick + delay){
119 sideB->sendPkt(inboundA.front());
120 inboundB.pop_front();
121 }
122 if (inboundB.size())
123 if (t == 0)
124 t = inboundB.front().second + delay;
125 else
126 t = std::min(t,inboundB.front().second + delay);
127 } else {
128 panic("timerEvent() called but nothing to do?");
129 }
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126
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131 if (t != 0)
132 sendEvent.schedule(t);
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127 sendQueue.push_back(buf); 128 129 // Did we just become blocked? If yes, let other side know. 130 if (queueFull()) 131 otherPort->sendStatusChange(Port::Blocked); 132 133 return true; |
134} 135 136 137void
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137Bridge::BridgePort::sendPkt(Packet *pkt)
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138Bridge::BridgePort::finishSend(PacketBuffer *buf) |
139{
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139 if (!sendTiming(pkt))
140 outbound.push_back(std::make_pair<Packet*,Tick>(pkt, curTick));
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140 if (buf->expectResponse) { 141 // Must wait for response. We just need to count outstanding 142 // responses (in case we want to cap them); PacketBuffer 143 // pointer will be recovered on response. 144 ++outstandingResponses; 145 DPRINTF(BusBridge, " successful: awaiting response (%d)\n", 146 outstandingResponses); 147 } else { 148 // no response expected... deallocate packet buffer now. 149 DPRINTF(BusBridge, " successful: no response expected\n"); 150 delete buf; 151 } 152 153 // If there are more packets to send, schedule event to try again. 154 if (!sendQueue.empty()) { 155 buf = sendQueue.front(); 156 sendEvent.schedule(std::max(buf->ready, curTick + 1)); 157 } |
158} 159
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160 |
161void
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144Bridge::BridgePort::sendPkt(std::pair<Packet*, Tick> p)
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162Bridge::BridgePort::trySend() |
163{
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146 if (!sendTiming(p.first))
147 outbound.push_back(p);
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164 assert(!sendQueue.empty()); 165 166 PacketBuffer *buf = sendQueue.front(); 167 168 assert(buf->ready <= curTick); 169 170 Packet *pkt = buf->pkt; 171 172 DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n", 173 buf->origSrc, pkt->getDest(), pkt->getAddr()); 174 175 if (sendTiming(pkt)) { 176 // send successful 177 sendQueue.pop_front(); 178 buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it 179 finishSend(buf); 180 } else { 181 DPRINTF(BusBridge, " unsuccessful\n"); 182 } |
183} 184 185 186Packet * 187Bridge::BridgePort::recvRetry() 188{
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154 Packet *pkt;
155 assert(outbound.size() > 0);
156 assert(outbound.front().second >= curTick + bridge->delay);
157 pkt = outbound.front().first;
158 outbound.pop_front();
159 bridge->blockCheck(side);
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189 PacketBuffer *buf = sendQueue.front(); 190 Packet *pkt = buf->pkt; 191 finishSend(buf); |
192 return pkt; 193} 194
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163/** Function called by the port when the bus is recieving a Atomic
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195/** Function called by the port when the bus is receiving a Atomic |
196 * transaction.*/ 197Tick
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166Bridge::recvAtomic(Packet *pkt, Side id)
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198Bridge::BridgePort::recvAtomic(Packet *pkt) |
199{
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168 pkt->time += delay;
169
170 if (id == SideA)
171 return sideB->sendAtomic(pkt);
172 else
173 return sideA->sendAtomic(pkt);
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200 return otherPort->sendAtomic(pkt) + delay; |
201} 202
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176/** Function called by the port when the bus is recieving a Functional
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203/** Function called by the port when the bus is receiving a Functional |
204 * transaction.*/ 205void
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179Bridge::recvFunctional(Packet *pkt, Side id)
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206Bridge::BridgePort::recvFunctional(Packet *pkt) |
207{
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181 pkt->time += delay;
182 std::list<std::pair<Packet*, Tick> >::iterator i;
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208 std::list<PacketBuffer*>::iterator i; |
209 bool pktContinue = true; 210
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185 for(i = inboundA.begin(); i != inboundA.end(); ++i) {
186 if (pkt->intersect(i->first)) {
187 pktContinue &= fixPacket(pkt, i->first);
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211 for (i = sendQueue.begin(); i != sendQueue.end(); ++i) { 212 if (pkt->intersect((*i)->pkt)) { 213 pktContinue &= fixPacket(pkt, (*i)->pkt); |
214 } 215 } 216
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191 for(i = inboundB.begin(); i != inboundB.end(); ++i) {
192 if (pkt->intersect(i->first)) {
193 pktContinue &= fixPacket(pkt, i->first);
194 }
195 }
196
197 for(i = sideA->outbound.begin(); i != sideA->outbound.end(); ++i) {
198 if (pkt->intersect(i->first)) {
199 pktContinue &= fixPacket(pkt, i->first);
200 }
201 }
202
203 for(i = sideB->outbound.begin(); i != sideB->outbound.end(); ++i) {
204 if (pkt->intersect(i->first)) {
205 pktContinue &= fixPacket(pkt, i->first);
206 }
207 }
208
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217 if (pktContinue) {
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210 if (id == SideA)
211 sideB->sendFunctional(pkt);
212 else
213 sideA->sendFunctional(pkt);
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218 otherPort->sendFunctional(pkt); |
219 } 220} 221
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217/** Function called by the port when the bus is recieving a status change.*/
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222/** Function called by the port when the bus is receiving a status change.*/ |
223void
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219Bridge::recvStatusChange(Port::Status status, Side id)
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224Bridge::BridgePort::recvStatusChange(Port::Status status) |
225{ 226 if (status == Port::Blocked || status == Port::Unblocked)
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222 return ;
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227 return; |
228
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224 if (id == SideA)
225 sideB->sendStatusChange(status);
226 else
227 sideA->sendStatusChange(status);
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229 otherPort->sendStatusChange(status); |
230} 231 232void
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231Bridge::addressRanges(AddrRangeList &resp, AddrRangeList &snoop, Side id)
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233Bridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp, 234 AddrRangeList &snoop) |
235{
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233 if (id == SideA)
234 sideB->getPeerAddressRanges(resp, snoop);
235 else
236 sideA->getPeerAddressRanges(resp, snoop);
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236 otherPort->getPeerAddressRanges(resp, snoop); |
237} 238 239BEGIN_DECLARE_SIM_OBJECT_PARAMS(Bridge) 240 241 Param<int> queue_size_a; 242 Param<int> queue_size_b; 243 Param<Tick> delay; 244 Param<bool> write_ack; 245 246END_DECLARE_SIM_OBJECT_PARAMS(Bridge) 247 248BEGIN_INIT_SIM_OBJECT_PARAMS(Bridge) 249 250 INIT_PARAM(queue_size_a, "The size of the queue for data coming into side a"), 251 INIT_PARAM(queue_size_b, "The size of the queue for data coming into side b"), 252 INIT_PARAM(delay, "The miminum delay to cross this bridge"), 253 INIT_PARAM(write_ack, "Acknowledge any writes that are received.") 254 255END_INIT_SIM_OBJECT_PARAMS(Bridge) 256 257CREATE_SIM_OBJECT(Bridge) 258{ 259 return new Bridge(getInstanceName(), queue_size_a, queue_size_b, delay, 260 write_ack); 261} 262 263REGISTER_SIM_OBJECT("Bridge", Bridge)
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