e19cf3d375
Change-Id: I42b6241057dab661aeaad695d48f62f70f163832 Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25406 Maintainer: Gabe Black <gabeblack@google.com> Tested-by: kokoro <noreply+kokoro@google.com> Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
107 lines
5.0 KiB
Plaintext
107 lines
5.0 KiB
Plaintext
/*
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* Copyright (c) 2017 Jason Lowe-Power
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met: redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer;
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* redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution;
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* neither the name of the copyright holders nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* This file contains the messages and other types for a simple MSI protocol.
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*
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* The protocol in this file is based off of the MSI protocol found in
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* A Primer on Memory Consistency and Cache Coherence
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* Daniel J. Sorin, Mark D. Hill, and David A. Wood
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* Synthesis Lectures on Computer Architecture 2011 6:3, 141-149
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*
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* See Learning gem5 Part 3: Ruby for more details.
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*/
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enumeration(CoherenceRequestType, desc="Types of request messages") {
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GetS, desc="Request from cache for a block with read permission";
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GetM, desc="Request from cache for a block with write permission";
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PutS, desc="Sent to directory when evicting a block in S (clean WB)";
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PutM, desc="Sent to directory when evicting a block in M";
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// "Requests" from the directory to the caches on the fwd network
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Inv, desc="Probe the cache and invalidate any matching blocks";
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PutAck, desc="The put request has been processed.";
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}
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enumeration(CoherenceResponseType, desc="Types of response messages") {
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Data, desc="Contains the most up-to-date data";
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InvAck, desc="Message from another cache that they have inv. the blk";
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}
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structure(RequestMsg, desc="Used for Cache->Dir and Fwd messages",
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interface="Message") {
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// NOTE: You can't name addr "Addr" because it would conflict with the
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// Addr *type*.
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Addr addr, desc="Physical address for this request";
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CoherenceRequestType Type, desc="Type of request";
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MachineID Requestor, desc="Node who initiated the request";
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NetDest Destination, desc="Multicast destination mask";
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DataBlock DataBlk, desc="data for the cache line";
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// NOTE: You *must* use MessageSize as the name of this variable, and it's
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// required that you have a MessageSize for each type of message. You will
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// the the error "panic: MessageSizeType() called on wrong message!"
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MessageSizeType MessageSize, desc="size category of the message";
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// This must be overridden here to support functional accesses
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bool functionalRead(Packet *pkt) {
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// Requests should never have the only copy of the most up-to-date data
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return false;
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}
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bool functionalWrite(Packet *pkt) {
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// No check on message type required since the protocol should read
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// data block from only those messages that contain valid data
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return testAndWrite(addr, DataBlk, pkt);
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}
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}
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structure(ResponseMsg, desc="Used for Cache->Dir and Fwd messages",
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interface="Message") {
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Addr addr, desc="Physical address for this response";
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CoherenceResponseType Type, desc="Type of response";
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MachineID Sender, desc="Node who is responding to the request";
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NetDest Destination, desc="Multicast destination mask";
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DataBlock DataBlk, desc="data for the cache line";
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MessageSizeType MessageSize, desc="size category of the message";
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int Acks, desc="Number of acks required from others";
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// This must be overridden here to support functional accesses
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bool functionalRead(Packet *pkt) {
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if (Type == CoherenceResponseType:Data) {
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return testAndRead(addr, DataBlk, pkt);
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}
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return false;
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}
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bool functionalWrite(Packet *pkt) {
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// No check on message type required since the protocol should read
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// data block from only those messages that contain valid data
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return testAndWrite(addr, DataBlk, pkt);
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}
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}
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