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Diffstat (limited to 'src/learning_gem5/part3/MSI-msg.sm')
| -rw-r--r-- | src/learning_gem5/part3/MSI-msg.sm | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/src/learning_gem5/part3/MSI-msg.sm b/src/learning_gem5/part3/MSI-msg.sm new file mode 100644 index 000000000..6ef409e87 --- /dev/null +++ b/src/learning_gem5/part3/MSI-msg.sm @@ -0,0 +1,108 @@ +/* + * Copyright (c) 2017 Jason Lowe-Power + * 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. + */ + +/** + * This file contains the messages and other types for a simple MSI protocol. + * + * The protocol in this file is based off of the MSI protocol found in + * A Primer on Memory Consistency and Cache Coherence + * Daniel J. Sorin, Mark D. Hill, and David A. Wood + * Synthesis Lectures on Computer Architecture 2011 6:3, 141-149 + * + * See Learning gem5 Part 3: Ruby for more details. + * + * Authors: Jason Lowe-Power + */ + +enumeration(CoherenceRequestType, desc="Types of request messages") { + GetS, desc="Request from cache for a block with read permission"; + GetM, desc="Request from cache for a block with write permission"; + PutS, desc="Sent to directory when evicting a block in S (clean WB)"; + PutM, desc="Sent to directory when evicting a block in M"; + + // "Requests" from the directory to the caches on the fwd network + Inv, desc="Probe the cache and invalidate any matching blocks"; + PutAck, desc="The put request has been processed."; +} + +enumeration(CoherenceResponseType, desc="Types of response messages") { + Data, desc="Contains the most up-to-date data"; + InvAck, desc="Message from another cache that they have inv. the blk"; +} + +structure(RequestMsg, desc="Used for Cache->Dir and Fwd messages", + interface="Message") { + // NOTE: You can't name addr "Addr" because it would conflict with the + // Addr *type*. + Addr addr, desc="Physical address for this request"; + CoherenceRequestType Type, desc="Type of request"; + MachineID Requestor, desc="Node who initiated the request"; + NetDest Destination, desc="Multicast destination mask"; + DataBlock DataBlk, desc="data for the cache line"; + // NOTE: You *must* use MessageSize as the name of this variable, and it's + // required that you have a MessageSize for each type of message. You will + // the the error "panic: MessageSizeType() called on wrong message!" + MessageSizeType MessageSize, desc="size category of the message"; + + // This must be overridden here to support functional accesses + bool functionalRead(Packet *pkt) { + // Requests should never have the only copy of the most up-to-date data + return false; + } + + bool functionalWrite(Packet *pkt) { + // No check on message type required since the protocol should read + // data block from only those messages that contain valid data + return testAndWrite(addr, DataBlk, pkt); + } +} + +structure(ResponseMsg, desc="Used for Cache->Dir and Fwd messages", + interface="Message") { + Addr addr, desc="Physical address for this response"; + CoherenceResponseType Type, desc="Type of response"; + MachineID Sender, desc="Node who is responding to the request"; + NetDest Destination, desc="Multicast destination mask"; + DataBlock DataBlk, desc="data for the cache line"; + MessageSizeType MessageSize, desc="size category of the message"; + int Acks, desc="Number of acks required from others"; + + // This must be overridden here to support functional accesses + bool functionalRead(Packet *pkt) { + if (Type == CoherenceResponseType:Data) { + return testAndRead(addr, DataBlk, pkt); + } + return false; + } + + bool functionalWrite(Packet *pkt) { + // No check on message type required since the protocol should read + // data block from only those messages that contain valid data + return testAndWrite(addr, DataBlk, pkt); + } +} |