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mem-ruby: Implement MakeReadUnique in CHI (#1101)

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Change-Id: I64cd3c62804cca184d68287fc099534e9205f2b8
Reviewed-by: Tiago Muck <tiago.muck@arm.com>

Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
This commit is contained in:
Giacomo Travaglini
2024-05-06 07:30:59 +01:00
committed by GitHub
parent 7c9925bafa
commit 36c1ea9c61
5 changed files with 123 additions and 3 deletions
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73
src/mem/ruby/protocol/chi/CHI-cache-actions.sm
View File

@@ -682,6 +682,42 @@ action(Initiate_ReadUnique_Hit_InvUpstream, desc="") {
tbe.actions.pushNB(Event:TagArrayWrite);
}
action(Initiate_MakeReadUnique_Hit_InvUpstream, desc="") {
assert(tbe.reqType == CHIRequestType:MakeReadUnique);
tbe.actions.push(Event:ReadHitPipe);
if (tbe.dir_sharers.count() > 1) {
tbe.actions.push(Event:SendSnpCleanInvalidNoReq);
}
if (!tbe.dataUnique && !is_HN) {
tbe.actions.push(Event:SendMakeReadUnique);
}
tbe.actions.pushNB(Event:DataArrayRead);
tbe.actions.push(Event:FinishMakeReadUnique);
}
action(Finish_MakeReadUnique, desc="") {
// Choosing whether to send or not data back (CompData vs Comp)
// to the requestor. Data will be forwarded if the requestor
// lost the cacheline while the transaction was in progress
if (tbe.dataValid && tbe.dir_sharers.isElement(tbe.requestor) == false) {
tbe.actions.pushNB(Event:SendCompData);
} else {
if (tbe.dataDirty) {
// Got dirty data from snoopees
tbe.actions.pushNB(Event:SendCompUDResp);
} else {
tbe.actions.pushNB(Event:SendCompUCResp);
}
}
tbe.dataUnique := true;
tbe.dataMaybeDirtyUpstream := true;
tbe.requestorToBeExclusiveOwner := true;
tbe.dir_ownerExists := false;
tbe.actions.pushNB(Event:TagArrayWrite);
tbe.actions.push(Event:WaitCompAck);
}
action(Initiate_CleanUnique, desc="") {
tbe.actions.push(Event:ReadMissPipe); // TODO need another latency pipe ??
@@ -1587,6 +1623,28 @@ action(Send_ReadUnique, desc="") {
}
}
action(Send_MakeReadUnique, desc="") {
assert((tbe.dataValid && tbe.dataUnique) == false);
assert(tbe.expected_req_resp.hasExpected() == false);
clearExpectedReqResp(tbe);
tbe.expected_req_resp.addExpectedDataType(CHIDataType:DataSepResp_UC);
tbe.expected_req_resp.addExpectedDataType(CHIDataType:CompData_UC);
tbe.expected_req_resp.addExpectedDataType(CHIDataType:CompData_UD_PD);
// NOTE: the first CompData received counts as RespSepData
tbe.expected_req_resp.addExpectedRespType(CHIResponseType:RespSepData);
tbe.expected_req_resp.addExpectedRespType(CHIResponseType:Comp_UC);
tbe.expected_req_resp.addExpectedRespType(CHIResponseType:Comp_UD_PD);
tbe.expected_req_resp.setExpectedCount(2);
enqueue(reqOutPort, CHIRequestMsg, request_latency) {
prepareRequest(tbe, CHIRequestType:MakeReadUnique, out_msg);
out_msg.Destination.add(mapAddressToDownstreamMachine(tbe.addr));
out_msg.dataToFwdRequestor := false;
allowRequestRetry(tbe, out_msg);
}
}
action(Send_CleanUnique, desc="") {
assert(tbe.dataValid || (tbe.dir_sharers.count() > 0));
assert(tbe.dataUnique == false);
@@ -2670,7 +2728,8 @@ action(Send_CompData, desc="") {
bool is_rd_shared := (tbe.reqType == CHIRequestType:ReadShared) ||
(tbe.reqType == CHIRequestType:ReadNotSharedDirty);
bool is_rd_nsd := tbe.reqType == CHIRequestType:ReadNotSharedDirty;
bool is_rd_unique := tbe.reqType == CHIRequestType:ReadUnique;
bool is_rd_unique := tbe.reqType == CHIRequestType:ReadUnique ||
tbe.reqType == CHIRequestType:MakeReadUnique;
// Send UC/UD on ReadShared or ReadNotSharedDirty if the line has no sharers
// and one of the followings are met
@@ -3095,6 +3154,18 @@ action(Send_CompUC_Stale, desc="") {
}
}
action(Send_CompUD_PD, desc="") {
assert(is_valid(tbe));
enqueue(rspOutPort, CHIResponseMsg, response_latency) {
out_msg.addr := address;
out_msg.type := CHIResponseType:Comp_UD_PD;
out_msg.responder := machineID;
out_msg.Destination.add(tbe.requestor);
out_msg.txnId := tbe.txnId;
out_msg.dbid := tbe.txnId;
}
}
action(Send_CompAck, desc="") {
assert(is_valid(tbe));
enqueue(rspOutPort, CHIResponseMsg, response_latency) {

8
src/mem/ruby/protocol/chi/CHI-cache-funcs.sm
View File

@@ -798,13 +798,15 @@ bool needCacheEntry(CHIRequestType req_type,
(enable_DMT && is_invalid(dir_entry) &&
((req_type == CHIRequestType:ReadShared) ||
(req_type == CHIRequestType:ReadUnique) ||
(req_type == CHIRequestType:MakeReadUnique) ||
(req_type == CHIRequestType:ReadOnce)))) {
return false;
} else {
return is_prefetch ||
(alloc_on_readshared && ((req_type == CHIRequestType:ReadShared) ||
(req_type == CHIRequestType:ReadNotSharedDirty))) ||
(alloc_on_readunique && (req_type == CHIRequestType:ReadUnique)) ||
(alloc_on_readunique && ((req_type == CHIRequestType:ReadUnique) ||
(req_type == CHIRequestType:MakeReadUnique))) ||
(alloc_on_readonce && (req_type == CHIRequestType:ReadOnce)) ||
(alloc_on_writeback && ((req_type == CHIRequestType:WriteBackFull) ||
(req_type == CHIRequestType:WriteCleanFull) ||
@@ -824,6 +826,7 @@ bool needDeallocCacheEntry(CHIRequestType req_type) {
return (dealloc_on_shared && ((req_type == CHIRequestType:ReadShared) ||
(req_type == CHIRequestType:ReadNotSharedDirty))) ||
(dealloc_on_unique && ((req_type == CHIRequestType:ReadUnique) ||
(req_type == CHIRequestType:MakeReadUnique) ||
(req_type == CHIRequestType:CleanUnique)));
}
@@ -1185,6 +1188,7 @@ bool isReadReqType(CHIRequestType type) {
if (type == CHIRequestType:Load ||
type == CHIRequestType:ReadShared ||
type == CHIRequestType:ReadNotSharedDirty ||
type == CHIRequestType:MakeReadUnique ||
type == CHIRequestType:ReadOnce) {
return true;
}
@@ -1243,6 +1247,8 @@ Event reqToEvent(CHIRequestType type, bool is_prefetch) {
return Event:CleanUnique;
} else if (type == CHIRequestType:ReadOnce) {
return Event:ReadOnce;
} else if (type == CHIRequestType:MakeReadUnique) {
return Event:MakeReadUnique;
} else if (type == CHIRequestType:Evict) {
return Event:Evict;
} else if (type == CHIRequestType:WriteBackFull) {

39
src/mem/ruby/protocol/chi/CHI-cache-transitions.sm
View File

@@ -1,5 +1,5 @@
/*
* Copyright (c) 2021-2023 Arm Limited
* Copyright (c) 2021-2024 Arm Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
@@ -332,6 +332,29 @@ transition({SC_RSC, SD_RSC, RSC, SD_RSD, RSD}, ReadUnique, BUSY_BLKD) {
ProcessNextState;
}
// MakeReadUnique
transition({UD_RSC,UC_RSC,UD_RSD}, MakeReadUnique, BUSY_BLKD) {
Initiate_Request;
Initiate_MakeReadUnique_Hit_InvUpstream;
Profile_Hit;
Pop_ReqRdyQueue;
ProcessNextState;
}
transition({RUSD,RUSC,RSC,RSD,SC_RSC,SD_RSC,SD_RSD}, MakeReadUnique, BUSY_BLKD) {
Initiate_Request;
Initiate_MakeReadUnique_Hit_InvUpstream;
Profile_Miss;
Pop_ReqRdyQueue;
ProcessNextState;
}
transition({BUSY_BLKD, BUSY_INTR}, FinishMakeReadUnique, BUSY_BLKD) {
Pop_TriggerQueue;
Finish_MakeReadUnique;
ProcessNextState_ClearPending;
}
// CleanUnique
transition({I, SC, UC, SD, UD, RU, RSC, RSD, RUSD, RUSC,
@@ -927,6 +950,7 @@ transition({BUSY_BLKD,BUSY_INTR},
{ReadShared, ReadNotSharedDirty, ReadUnique, ReadUnique_PoC,
ReadOnce, CleanUnique, CleanUnique_Stale,
Load, Store, AtomicLoad, AtomicStore, Prefetch,
MakeReadUnique,
WriteBackFull, WriteBackFull_Stale,
WriteEvictFull, WriteEvictFull_Stale,
WriteCleanFull, WriteCleanFull_Stale,
@@ -1151,6 +1175,12 @@ transition(BUSY_BLKD, SendCompUCRespStale) {
ProcessNextState_ClearPending;
}
transition(BUSY_BLKD, SendCompUDResp) {
Pop_TriggerQueue;
Send_CompUD_PD;
ProcessNextState_ClearPending;
}
transition(BUSY_BLKD, SendRespSepData) {
Pop_TriggerQueue;
Send_RespSepData;
@@ -1189,6 +1219,13 @@ transition(BUSY_BLKD, SendReadUnique, BUSY_INTR) {DestinationAvailable} {
ProcessNextState_ClearPending;
}
transition(BUSY_BLKD, SendMakeReadUnique, BUSY_INTR) {DestinationAvailable} {
Pop_TriggerQueue;
Send_MakeReadUnique;
Profile_OutgoingStart;
ProcessNextState_ClearPending;
}
transition(BUSY_BLKD, SendCleanUnique, BUSY_INTR) {DestinationAvailable} {
Pop_TriggerQueue;
Send_CleanUnique;

4
src/mem/ruby/protocol/chi/CHI-cache.sm
View File

@@ -313,6 +313,7 @@ machine(MachineType:Cache, "Cache coherency protocol") :
ReadUnique_PoC, desc="", in_trans="yes";
ReadOnce, desc="", in_trans="yes";
CleanUnique, desc="", in_trans="yes";
MakeReadUnique, desc="", in_trans="yes";
Evict, desc="", in_trans="yes";
WriteBackFull, desc="", in_trans="yes";
WriteEvictFull, desc="", in_trans="yes";
@@ -464,6 +465,7 @@ machine(MachineType:Cache, "Cache coherency protocol") :
SendReadNoSnp, out_trans="yes", desc="Send a SendReadNoSnp";
SendReadNoSnpDMT, out_trans="yes", desc="Send a SendReadNoSnp using DMT";
SendReadUnique, out_trans="yes", desc="Send a ReadUnique";
SendMakeReadUnique, out_trans="yes", desc="Send a MakeReadUnique";
SendCompAck, desc="Send CompAck";
// Read handling at the completer
SendCompData, desc="Send CompData";
@@ -505,6 +507,7 @@ machine(MachineType:Cache, "Cache coherency protocol") :
SendCleanUnique,out_trans="yes", desc="Send a CleanUnique";
SendCompUCResp, desc="Ack CleanUnique with Comp_UC";
SendCompUCRespStale, desc="Ack stale CleanUnique with Comp_UC";
SendCompUDResp, desc="Ack MakeReadUnique with Comp_UD_PD";
// Checks if an upgrade using a CleanUnique was sucessfull
CheckUpgrade_FromStore, desc="Upgrade needed by a Store";
@@ -552,6 +555,7 @@ machine(MachineType:Cache, "Cache coherency protocol") :
TX_Data, desc="Transmit pending data messages";
MaintainCoherence, desc="Queues a WriteBack or Evict before droping the only valid copy of the block";
FinishCleanUnique, desc="Sends acks and perform any writeback after a CleanUnique";
FinishMakeReadUnique, desc="Return Comp or CompData to requestor at the end of MakeReadUnique";
FinishCopyBack_Stale, desc="Check if a Evict needs to be sent";
ActionStalledOnHazard, desc="Stall a trigger action because until finish handling snoop hazard";
WriteZero, desc="Stall a trigger action because until finish handling snoop hazard";

2
src/mem/ruby/protocol/chi/CHI-msg.sm
View File

@@ -59,6 +59,7 @@ enumeration(CHIRequestType, desc="") {
ReadUnique;
ReadOnce;
CleanUnique;
MakeReadUnique;
Evict;
@@ -134,6 +135,7 @@ enumeration(CHIResponseType, desc="...") {
// CHI response types
Comp_I;
Comp_UC;
Comp_UD_PD;
Comp_SC;
CompAck;
CompDBIDResp;