1/* |
2 * Copyright (c) 2012 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) 2006 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 --- 11 unchanged lines hidden (view full) --- 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: Ali Saidi |
41 * Andreas Hansson |
42 */ 43 44#include "debug/Bus.hh" 45#include "mem/mem_object.hh" 46#include "mem/tport.hh" 47 48using namespace std; 49 |
50SimpleTimingPort::SimpleTimingPort(const string &_name, MemObject *_owner, 51 const string _label) 52 : Port(_name, _owner), label(_label), sendEvent(this), drainEvent(NULL), |
53 waitingOnRetry(false) 54{ |
55} 56 57SimpleTimingPort::~SimpleTimingPort() 58{ |
59} 60 61bool 62SimpleTimingPort::checkFunctional(PacketPtr pkt) 63{ |
64 pkt->pushLabel(label); 65 |
66 DeferredPacketIterator i = transmitList.begin(); 67 DeferredPacketIterator end = transmitList.end(); |
68 bool found = false; |
69 |
70 while (!found && i != end) { 71 // If the buffered packet contains data, and it overlaps the 72 // current packet, then update data 73 found = pkt->checkFunctional(i->pkt); 74 ++i; |
75 } 76 |
77 pkt->popLabel(); 78 79 return found; |
80} 81 82void 83SimpleTimingPort::recvFunctional(PacketPtr pkt) 84{ 85 if (!checkFunctional(pkt)) { 86 // Just do an atomic access and throw away the returned latency 87 recvAtomic(pkt); --- 29 unchanged lines hidden (view full) --- 117 } 118 119 return true; 120} 121 122void 123SimpleTimingPort::schedSendEvent(Tick when) 124{ |
125 // if we are waiting on a retry, do not schedule a send event, and 126 // instead rely on retry being called |
127 if (waitingOnRetry) { |
128 assert(!sendEvent.scheduled()); |
129 return; 130 } 131 |
132 if (!sendEvent.scheduled()) { 133 owner->schedule(&sendEvent, when); 134 } else if (sendEvent.when() > when) { 135 owner->reschedule(&sendEvent, when); |
136 } 137} 138 139void 140SimpleTimingPort::schedSendTiming(PacketPtr pkt, Tick when) 141{ 142 assert(when > curTick()); 143 assert(when < curTick() + SimClock::Int::ms); --- 20 unchanged lines hidden (view full) --- 164 if (when < i->tick) { 165 transmitList.insert(i, DeferredPacket(when, pkt)); 166 return; 167 } 168 } 169 assert(false); // should never get here 170} 171 |
172void SimpleTimingPort::trySendTiming() |
173{ 174 assert(deferredPacketReady()); |
175 // take the next packet off the list here, as we might return to 176 // ourselves through the sendTiming call below |
177 DeferredPacket dp = transmitList.front(); 178 transmitList.pop_front(); |
179 |
180 // attempt to send the packet and remember the outcome 181 waitingOnRetry = !sendTiming(dp.pkt); |
182 |
183 if (waitingOnRetry) { 184 // put the packet back at the front of the list (packet should 185 // not have changed since it wasn't accepted) 186 assert(!sendEvent.scheduled()); 187 transmitList.push_front(dp); 188 } 189} 190 191void 192SimpleTimingPort::scheduleSend(Tick time) 193{ 194 // the next ready time is either determined by the next deferred packet, 195 // or in the cache through the MSHR ready time 196 Tick nextReady = std::min(deferredPacketReadyTime(), time); 197 if (nextReady != MaxTick) { 198 // if the sendTiming caused someone else to call our 199 // recvTiming we could already have an event scheduled, check 200 if (!sendEvent.scheduled()) 201 owner->schedule(&sendEvent, std::max(nextReady, curTick() + 1)); 202 } else { 203 // no more to send, so if we're draining, we may be done 204 if (drainEvent && !sendEvent.scheduled()) { |
205 drainEvent->process(); 206 drainEvent = NULL; 207 } |
208 } |
209} |
210 |
211void 212SimpleTimingPort::sendDeferredPacket() 213{ 214 // try to send what is on the list 215 trySendTiming(); |
216 |
217 // if we succeeded and are not waiting for a retry, schedule the 218 // next send 219 if (!waitingOnRetry) { 220 scheduleSend(); |
221 } 222} 223 224 225void 226SimpleTimingPort::recvRetry() 227{ 228 DPRINTF(Bus, "Received retry\n"); |
229 // note that in the cache we get a retry even though we may not 230 // have a packet to retry (we could potentially decide on a new 231 // packet every time we retry) |
232 assert(waitingOnRetry); 233 sendDeferredPacket(); 234} 235 236 237void 238SimpleTimingPort::processSendEvent() 239{ 240 assert(!waitingOnRetry); 241 sendDeferredPacket(); 242} 243 244 245unsigned int 246SimpleTimingPort::drain(Event *de) 247{ |
248 if (transmitList.empty() && !sendEvent.scheduled()) |
249 return 0; 250 drainEvent = de; 251 return 1; 252} |