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/*
* Copyright (c) 2013 Mark D. Hill and David A. Wood
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// Various class of messages that can be exchanged between the L0 and the L1
// controllers.
enumeration(CoherenceClass, desc="...") {
GETX, desc="Get eXclusive";
UPGRADE, desc="UPGRADE to exclusive";
GETS, desc="Get Shared";
GET_INSTR, desc="Get Instruction";
INV, desc="INValidate";
PUTX, desc="Replacement message";
WB_ACK, desc="Writeback ack";
// Request types for sending data and acks from L0 to L1 cache
// when an invalidation message is received.
INV_DATA;
INV_ACK;
DATA, desc="Data block for L1 cache in S state";
DATA_EXCLUSIVE, desc="Data block for L1 cache in M/E state";
ACK, desc="Generic invalidate ack";
// This is a special case in which the L1 cache lost permissions to the
// shared block before it got the data. So the L0 cache can use the data
// but not store it.
STALE_DATA;
}
// Class for messages sent between the L0 and the L1 controllers.
structure(CoherenceMsg, desc="...", interface="Message") {
Address Addr, desc="Physical address of the cache block";
CoherenceClass Class, desc="Type of message (GetS, GetX, PutX, etc)";
RubyAccessMode AccessMode, desc="user/supervisor access type";
MachineID Sender, desc="What component sent this message";
MachineID Dest, desc="What machine receives this message";
MessageSizeType MessageSize, desc="size category of the message";
DataBlock DataBlk, desc="Data for the cache line (if PUTX)";
bool Dirty, default="false", desc="Dirty bit";
bool functionalRead(Packet *pkt) {
// Only PUTX messages contains the data block
if (Class == CoherenceClass:PUTX) {
return testAndRead(Addr, DataBlk, pkt);
}
return false;
}
bool functionalWrite(Packet *pkt) {
// No check on message type required since the protocol should
// read data from those messages that contain the block
return testAndWrite(Addr, DataBlk, pkt);
}
}
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