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-rw-r--r--src/mem/cache/coherence/coherence_protocol.cc257
-rw-r--r--src/mem/cache/coherence/coherence_protocol.hh20
2 files changed, 97 insertions, 180 deletions
diff --git a/src/mem/cache/coherence/coherence_protocol.cc b/src/mem/cache/coherence/coherence_protocol.cc
index 52beb0880..3d7721805 100644
--- a/src/mem/cache/coherence/coherence_protocol.cc
+++ b/src/mem/cache/coherence/coherence_protocol.cc
@@ -206,8 +206,7 @@ bool
CoherenceProtocol::supplyTrans(BaseCache *cache, PacketPtr &pkt,
CacheBlk *blk,
MSHR *mshr,
- CacheBlk::State & new_state
- )
+ CacheBlk::State & new_state)
{
return true;
}
@@ -263,182 +262,106 @@ CoherenceProtocol::CoherenceProtocol(const string &name,
const bool doUpgrades)
: SimObject(name)
{
- if ((protocol == "mosi" || protocol == "moesi") && !doUpgrades) {
- cerr << "CoherenceProtocol: ownership protocols require upgrade transactions"
- << "(write miss on owned block generates ReadExcl, which will clobber dirty block)"
- << endl;
- fatal("");
+ // Python should catch this, but in case it doesn't...
+ if (!(protocol == "msi" || protocol == "mesi" ||
+ protocol == "mosi" || protocol == "moesi")) {
+ fatal("CoherenceProtocol: unrecognized protocol %s\n", protocol);
}
- Packet::Command writeToSharedCmd = doUpgrades ? Packet::UpgradeReq : Packet::ReadExReq;
- Packet::Command writeToSharedResp = doUpgrades ? Packet::UpgradeReq : Packet::ReadExResp;
-
-//@todo add in hardware prefetch to this list
- if (protocol == "msi") {
- // incoming requests: specify outgoing bus request
- transitionTable[Invalid][Packet::ReadReq].onRequest(Packet::ReadReq);
- transitionTable[Invalid][Packet::WriteReq].onRequest(Packet::ReadExReq);
- transitionTable[Shared][Packet::WriteReq].onRequest(writeToSharedCmd);
- //Prefetching causes a read
- transitionTable[Invalid][Packet::SoftPFReq].onRequest(Packet::ReadReq);
- transitionTable[Invalid][Packet::HardPFReq].onRequest(Packet::ReadReq);
-
- // on response to given request: specify new state
- transitionTable[Invalid][Packet::ReadResp].onResponse(Shared);
- transitionTable[Invalid][Packet::ReadExResp].onResponse(Modified);
- transitionTable[Shared][writeToSharedResp].onResponse(Modified);
-
- // bus snoop transition functions
- transitionTable[Invalid][Packet::ReadReq].onSnoop(nullTransition);
- transitionTable[Invalid][Packet::ReadExReq].onSnoop(nullTransition);
- transitionTable[Shared][Packet::ReadReq].onSnoop(nullTransition);
- transitionTable[Shared][Packet::ReadExReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::ReadExReq].onSnoop(supplyAndInvalidateTrans);
- transitionTable[Modified][Packet::ReadReq].onSnoop(supplyAndGotoSharedTrans);
- //Tansitions on seeing a DMA (writeInv(samelevel) or DMAInv)
- transitionTable[Invalid][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Shared][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Invalid][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Shared][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
-
- if (doUpgrades) {
- transitionTable[Invalid][Packet::UpgradeReq].onSnoop(nullTransition);
- transitionTable[Shared][Packet::UpgradeReq].onSnoop(invalidateTrans);
- }
+ bool hasOwned = (protocol == "mosi" || protocol == "moesi");
+ bool hasExclusive = (protocol == "mesi" || protocol == "moesi");
+
+ if (hasOwned && !doUpgrades) {
+ fatal("CoherenceProtocol: ownership protocols require upgrade "
+ "transactions\n(write miss on owned block generates ReadExcl, "
+ "which will clobber dirty block)\n");
}
- else if(protocol == "mesi") {
- // incoming requests: specify outgoing bus request
- transitionTable[Invalid][Packet::ReadReq].onRequest(Packet::ReadReq);
- transitionTable[Invalid][Packet::WriteReq].onRequest(Packet::ReadExReq);
- transitionTable[Shared][Packet::WriteReq].onRequest(writeToSharedCmd);
- //Prefetching causes a read
- transitionTable[Invalid][Packet::SoftPFReq].onRequest(Packet::ReadReq);
- transitionTable[Invalid][Packet::HardPFReq].onRequest(Packet::ReadReq);
-
- // on response to given request: specify new state
- transitionTable[Invalid][Packet::ReadResp].onResponse(Exclusive);
- //It will move into shared if the shared line is asserted in the
- //getNewState function
- transitionTable[Invalid][Packet::ReadExResp].onResponse(Modified);
- transitionTable[Shared][writeToSharedResp].onResponse(Modified);
-
- // bus snoop transition functions
- transitionTable[Invalid][Packet::ReadReq].onSnoop(nullTransition);
- transitionTable[Invalid][Packet::ReadExReq].onSnoop(nullTransition);
- transitionTable[Shared][Packet::ReadReq].onSnoop(assertShared);
- transitionTable[Shared][Packet::ReadExReq].onSnoop(invalidateTrans);
- transitionTable[Exclusive][Packet::ReadReq].onSnoop(assertShared);
- transitionTable[Exclusive][Packet::ReadExReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::ReadExReq].onSnoop(supplyAndInvalidateTrans);
- transitionTable[Modified][Packet::ReadReq].onSnoop(supplyAndGotoSharedTrans);
- //Tansitions on seeing a DMA (writeInv(samelevel) or DMAInv)
- transitionTable[Invalid][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Shared][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Exclusive][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Invalid][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Shared][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Exclusive][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
-
- if (doUpgrades) {
- transitionTable[Invalid][Packet::UpgradeReq].onSnoop(nullTransition);
- transitionTable[Shared][Packet::UpgradeReq].onSnoop(invalidateTrans);
- }
+ // set up a few shortcuts to save typing & visual clutter
+ typedef Packet P;
+ StateTransition (&tt)[stateMax+1][NUM_MEM_CMDS] = transitionTable;
+
+ P::Command writeToSharedCmd = doUpgrades ? P::UpgradeReq : P::ReadExReq;
+ P::Command writeToSharedResp = doUpgrades ? P::UpgradeReq : P::ReadExResp;
+
+ // Note that all transitions by default cause a panic.
+ // Override the valid transitions with the appropriate actions here.
+
+ //
+ // ----- incoming requests: specify outgoing bus request -----
+ //
+ tt[Invalid][P::ReadReq].onRequest(P::ReadReq);
+ // we only support write allocate right now
+ tt[Invalid][P::WriteReq].onRequest(P::ReadExReq);
+ tt[Shared][P::WriteReq].onRequest(writeToSharedCmd);
+ if (hasOwned) {
+ tt[Owned][P::WriteReq].onRequest(writeToSharedCmd);
}
- else if(protocol == "mosi") {
- // incoming requests: specify outgoing bus request
- transitionTable[Invalid][Packet::ReadReq].onRequest(Packet::ReadReq);
- transitionTable[Invalid][Packet::WriteReq].onRequest(Packet::ReadExReq);
- transitionTable[Shared][Packet::WriteReq].onRequest(writeToSharedCmd);
- transitionTable[Owned][Packet::WriteReq].onRequest(writeToSharedCmd);
- //Prefetching causes a read
- transitionTable[Invalid][Packet::SoftPFReq].onRequest(Packet::ReadReq);
- transitionTable[Invalid][Packet::HardPFReq].onRequest(Packet::ReadReq);
-
- // on response to given request: specify new state
- transitionTable[Invalid][Packet::ReadResp].onResponse(Shared);
- transitionTable[Invalid][Packet::ReadExResp].onResponse(Modified);
- transitionTable[Shared][writeToSharedResp].onResponse(Modified);
- transitionTable[Owned][writeToSharedResp].onResponse(Modified);
-
- // bus snoop transition functions
- transitionTable[Invalid][Packet::ReadReq].onSnoop(nullTransition);
- transitionTable[Invalid][Packet::ReadExReq].onSnoop(nullTransition);
- transitionTable[Invalid][Packet::UpgradeReq].onSnoop(nullTransition);
- transitionTable[Shared][Packet::ReadReq].onSnoop(assertShared);
- transitionTable[Shared][Packet::ReadExReq].onSnoop(invalidateTrans);
- transitionTable[Shared][Packet::UpgradeReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::ReadExReq].onSnoop(supplyAndInvalidateTrans);
- transitionTable[Modified][Packet::ReadReq].onSnoop(supplyAndGotoOwnedTrans);
- transitionTable[Owned][Packet::ReadReq].onSnoop(supplyAndGotoOwnedTrans);
- transitionTable[Owned][Packet::ReadExReq].onSnoop(supplyAndInvalidateTrans);
- transitionTable[Owned][Packet::UpgradeReq].onSnoop(invalidateTrans);
- //Tansitions on seeing a DMA (writeInv(samelevel) or DMAInv)
- transitionTable[Invalid][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Shared][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Owned][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Invalid][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Shared][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Owned][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
+ // Prefetching causes a read
+ tt[Invalid][P::SoftPFReq].onRequest(P::ReadReq);
+ tt[Invalid][P::HardPFReq].onRequest(P::ReadReq);
+
+ //
+ // ----- on response to given request: specify new state -----
+ //
+ tt[Invalid][P::ReadExResp].onResponse(Modified);
+ tt[Shared][writeToSharedResp].onResponse(Modified);
+ // Go to Exclusive state on read response if we have one (will
+ // move into shared if the shared line is asserted in the
+ // getNewState function)
+ //
+ // originally had this as:
+ // tt[Invalid][P::ReadResp].onResponse(hasExclusive ? Exclusive: Shared);
+ // ...but for some reason that caused a link error...
+ if (hasExclusive) {
+ tt[Invalid][P::ReadResp].onResponse(Exclusive);
+ } else {
+ tt[Invalid][P::ReadResp].onResponse(Shared);
+ }
+ if (hasOwned) {
+ tt[Owned][writeToSharedResp].onResponse(Modified);
}
- else if(protocol == "moesi") {
- // incoming requests: specify outgoing bus request
- transitionTable[Invalid][Packet::ReadReq].onRequest(Packet::ReadReq);
- transitionTable[Invalid][Packet::WriteReq].onRequest(Packet::ReadExReq);
- transitionTable[Shared][Packet::WriteReq].onRequest(writeToSharedCmd);
- transitionTable[Owned][Packet::WriteReq].onRequest(writeToSharedCmd);
- //Prefetching causes a read
- transitionTable[Invalid][Packet::SoftPFReq].onRequest(Packet::ReadReq);
- transitionTable[Invalid][Packet::HardPFReq].onRequest(Packet::ReadReq);
-
- // on response to given request: specify new state
- transitionTable[Invalid][Packet::ReadResp].onResponse(Exclusive);
- //It will move into shared if the shared line is asserted in the
- //getNewState function
- transitionTable[Invalid][Packet::ReadExResp].onResponse(Modified);
- transitionTable[Shared][writeToSharedResp].onResponse(Modified);
- transitionTable[Owned][writeToSharedResp].onResponse(Modified);
-
- // bus snoop transition functions
- transitionTable[Invalid][Packet::ReadReq].onSnoop(nullTransition);
- transitionTable[Invalid][Packet::ReadExReq].onSnoop(nullTransition);
- transitionTable[Invalid][Packet::UpgradeReq].onSnoop(nullTransition);
- transitionTable[Shared][Packet::ReadReq].onSnoop(assertShared);
- transitionTable[Shared][Packet::ReadExReq].onSnoop(invalidateTrans);
- transitionTable[Shared][Packet::UpgradeReq].onSnoop(invalidateTrans);
- transitionTable[Exclusive][Packet::ReadReq].onSnoop(assertShared);
- transitionTable[Exclusive][Packet::ReadExReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::ReadReq].onSnoop(supplyAndGotoOwnedTrans);
- transitionTable[Modified][Packet::ReadExReq].onSnoop(supplyAndInvalidateTrans);
- transitionTable[Owned][Packet::ReadReq].onSnoop(supplyAndGotoOwnedTrans);
- transitionTable[Owned][Packet::ReadExReq].onSnoop(supplyAndInvalidateTrans);
- transitionTable[Owned][Packet::UpgradeReq].onSnoop(invalidateTrans);
- //Transitions on seeing a DMA (writeInv(samelevel) or DMAInv)
- transitionTable[Invalid][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Shared][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Exclusive][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Owned][Packet::InvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Invalid][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Shared][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Exclusive][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Modified][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
- transitionTable[Owned][Packet::WriteInvalidateReq].onSnoop(invalidateTrans);
+ //
+ // ----- bus snoop transition functions -----
+ //
+ tt[Invalid][P::ReadReq].onSnoop(nullTransition);
+ tt[Invalid][P::ReadExReq].onSnoop(nullTransition);
+ tt[Invalid][P::InvalidateReq].onSnoop(invalidateTrans);
+ tt[Invalid][P::WriteInvalidateReq].onSnoop(invalidateTrans);
+ tt[Shared][P::ReadReq].onSnoop(hasExclusive
+ ? assertShared : nullTransition);
+ tt[Shared][P::ReadExReq].onSnoop(invalidateTrans);
+ tt[Shared][P::InvalidateReq].onSnoop(invalidateTrans);
+ tt[Shared][P::WriteInvalidateReq].onSnoop(invalidateTrans);
+ if (doUpgrades) {
+ tt[Invalid][P::UpgradeReq].onSnoop(nullTransition);
+ tt[Shared][P::UpgradeReq].onSnoop(invalidateTrans);
+ }
+ tt[Modified][P::ReadExReq].onSnoop(supplyAndInvalidateTrans);
+ tt[Modified][P::ReadReq].onSnoop(hasOwned
+ ? supplyAndGotoOwnedTrans
+ : supplyAndGotoSharedTrans);
+ tt[Modified][P::InvalidateReq].onSnoop(invalidateTrans);
+ tt[Modified][P::WriteInvalidateReq].onSnoop(invalidateTrans);
+
+ if (hasExclusive) {
+ tt[Exclusive][P::ReadReq].onSnoop(assertShared);
+ tt[Exclusive][P::ReadExReq].onSnoop(invalidateTrans);
+ tt[Exclusive][P::InvalidateReq].onSnoop(invalidateTrans);
+ tt[Exclusive][P::WriteInvalidateReq].onSnoop(invalidateTrans);
}
- else {
- cerr << "CoherenceProtocol: unrecognized protocol " << protocol
- << endl;
- fatal("");
+ if (hasOwned) {
+ tt[Owned][P::ReadReq].onSnoop(supplyAndGotoOwnedTrans);
+ tt[Owned][P::ReadExReq].onSnoop(supplyAndInvalidateTrans);
+ tt[Owned][P::UpgradeReq].onSnoop(invalidateTrans);
+ tt[Owned][P::InvalidateReq].onSnoop(invalidateTrans);
+ tt[Owned][P::WriteInvalidateReq].onSnoop(invalidateTrans);
}
+
+ // @todo add in hardware prefetch to this list
}
diff --git a/src/mem/cache/coherence/coherence_protocol.hh b/src/mem/cache/coherence/coherence_protocol.hh
index b30fb053b..481277523 100644
--- a/src/mem/cache/coherence/coherence_protocol.hh
+++ b/src/mem/cache/coherence/coherence_protocol.hh
@@ -211,31 +211,25 @@ class CoherenceProtocol : public SimObject
friend class CoherenceProtocol::StateTransition;
/** Mask to select status bits relevant to coherence protocol. */
- const static CacheBlk::State
- stateMask = BlkValid | BlkWritable | BlkDirty;
+ static const int stateMask = BlkValid | BlkWritable | BlkDirty;
/** The Modified (M) state. */
- const static CacheBlk::State
- Modified = BlkValid | BlkWritable | BlkDirty;
+ static const int Modified = BlkValid | BlkWritable | BlkDirty;
/** The Owned (O) state. */
- const static CacheBlk::State
- Owned = BlkValid | BlkDirty;
+ static const int Owned = BlkValid | BlkDirty;
/** The Exclusive (E) state. */
- const static CacheBlk::State
- Exclusive = BlkValid | BlkWritable;
+ static const int Exclusive = BlkValid | BlkWritable;
/** The Shared (S) state. */
- const static CacheBlk::State
- Shared = BlkValid;
+ static const int Shared = BlkValid;
/** The Invalid (I) state. */
- const static CacheBlk::State
- Invalid = 0;
+ static const int Invalid = 0;
/**
* Maximum state encoding value (used to size transition lookup
* table). Could be more than number of states, depends on
* encoding of status bits.
*/
- const static int stateMax = stateMask;
+ static const int stateMax = stateMask;
/**
* The table of all possible transitions, organized by starting state and
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-06 08:12:46 +0000