diff options
| -rw-r--r-- | src/mem/cache/coherence/coherence_protocol.cc | 257 | ||||
| -rw-r--r-- | src/mem/cache/coherence/coherence_protocol.hh | 20 |
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 |