2 * Copyright (c) 2006 The Regents of The University of Michigan
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.
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.
31 #include "mem/tport.hh"
34 SimpleTimingPort::checkFunctional(PacketPtr pkt
)
36 DeferredPacketIterator i
= transmitList
.begin();
37 DeferredPacketIterator end
= transmitList
.end();
39 for (; i
!= end
; ++i
) {
40 PacketPtr target
= i
->pkt
;
41 // If the target contains data, and it overlaps the
42 // probed request, need to update data
43 if (target
->intersect(pkt
)) {
44 if (!fixPacket(pkt
, target
)) {
45 // fixPacket returns true for continue, false for done
53 SimpleTimingPort::recvFunctional(PacketPtr pkt
)
57 // Just do an atomic access and throw away the returned latency
58 if (pkt
->result
!= Packet::Success
)
63 SimpleTimingPort::recvTiming(PacketPtr pkt
)
65 // If the device is only a slave, it should only be sending
66 // responses, which should never get nacked. There used to be
67 // code to hanldle nacks here, but I'm pretty sure it didn't work
68 // correctly with the drain code, so that would need to be fixed
69 // if we ever added it back.
70 assert(pkt
->isRequest());
71 assert(pkt
->result
== Packet::Unknown
);
73 if (pkt
->memInhibitAsserted()) {
74 // snooper will supply based on copy of packet
75 // still target's responsibility to delete packet
81 bool needsResponse
= pkt
->needsResponse();
82 Tick latency
= recvAtomic(pkt
);
83 // turn packet around to go back to requester if response expected
85 // recvAtomic() should already have turned packet into
87 assert(pkt
->isResponse());
88 pkt
->convertAtomicToTimingResponse();
89 schedSendTiming(pkt
, curTick
+ latency
);
100 SimpleTimingPort::schedSendTiming(PacketPtr pkt
, Tick when
)
102 assert(when
> curTick
);
104 // Nothing is on the list: add it and schedule an event
105 if (transmitList
.empty() || when
< transmitList
.front().tick
) {
106 transmitList
.push_front(DeferredPacket(when
, pkt
));
107 schedSendEvent(when
);
111 // list is non-empty and this is not the head, so event should
112 // already be scheduled
113 assert(waitingOnRetry
||
114 (sendEvent
->scheduled() && sendEvent
->when() <= when
));
116 // list is non-empty & this belongs at the end
117 if (when
>= transmitList
.back().tick
) {
118 transmitList
.push_back(DeferredPacket(when
, pkt
));
122 // this belongs in the middle somewhere
123 DeferredPacketIterator i
= transmitList
.begin();
124 i
++; // already checked for insertion at front
125 DeferredPacketIterator end
= transmitList
.end();
127 for (; i
!= end
; ++i
) {
128 if (when
< i
->tick
) {
129 transmitList
.insert(i
, DeferredPacket(when
, pkt
));
133 assert(false); // should never get here
138 SimpleTimingPort::sendDeferredPacket()
140 assert(deferredPacketReady());
141 bool success
= sendTiming(transmitList
.front().pkt
);
144 //send successful, remove packet
145 transmitList
.pop_front();
146 if (!transmitList
.empty()) {
147 Tick time
= transmitList
.front().tick
;
148 sendEvent
->schedule(time
<= curTick
? curTick
+1 : time
);
151 if (transmitList
.empty() && drainEvent
) {
152 drainEvent
->process();
157 waitingOnRetry
= !success
;
159 if (waitingOnRetry
) {
160 DPRINTF(Bus
, "Send failed, waiting on retry\n");
166 SimpleTimingPort::recvRetry()
168 DPRINTF(Bus
, "Received retry\n");
169 assert(waitingOnRetry
);
170 sendDeferredPacket();
175 SimpleTimingPort::processSendEvent()
177 assert(!waitingOnRetry
);
178 sendDeferredPacket();
183 SimpleTimingPort::drain(Event
*de
)
185 if (transmitList
.size() == 0)