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

/*
 * Copyright (c) 2021 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * 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.
 */

////////////////////////////////////////////////////////////////////////////
// CHI-cache transition definition
////////////////////////////////////////////////////////////////////////////

// Allocate resources and move to the ready queue
transition({I,SC,UC,SD,UD,RU,RSC,RSD,RUSD,SC_RSC,UC_RSC,SD_RSC,UD_RSC,UC_RU,UD_RU,UD_RSD,SD_RSD,RUSC
            BUSY_INTR,BUSY_BLKD}, AllocRequest) {
  AllocateTBE_Request;
}

transition({I,SC,UC,SD,UD,RU,RSC,RSD,RUSD,SC_RSC,UC_RSC,SD_RSC,UD_RSC,UC_RU,UD_RU,UD_RSD,SD_RSD,RUSC
            BUSY_INTR,BUSY_BLKD}, AllocRequestWithCredit) {
  AllocateTBE_Request_WithCredit;
}

transition({I,SC,UC,SD,UD,RU,RSC,RSD,RUSD,SC_RSC,UC_RSC,SD_RSC,UD_RSC,UC_RU,UD_RU,UD_RSD,SD_RSD,RUSC
            BUSY_INTR,BUSY_BLKD}, SendRetryAck) {
  Send_RetryAck;
  Pop_RetryTriggerQueue;
}

transition({I,SC,UC,SD,UD,RU,RSC,RSD,RUSD,SC_RSC,UC_RSC,SD_RSC,UD_RSC,UC_RU,UD_RU,UD_RSD,SD_RSD,RUSC
            BUSY_INTR,BUSY_BLKD}, SendPCrdGrant) {
  Send_PCrdGrant;
  Pop_RetryTriggerQueue;
}

transition({I,SC,UC,SD,UD,UD_T,RU,RSC,RSD,RUSD,SC_RSC,UC_RSC,SD_RSC,UD_RSC,UC_RU,UD_RU,UD_RSD,SD_RSD,RUSC
            BUSY_INTR,BUSY_BLKD}, AllocSnoop) {
  AllocateTBE_Snoop;
}

transition({UD,UD_T,SD,UC,SC,I,BUSY_INTR,BUSY_BLKD}, AllocSeqRequest) {
  AllocateTBE_SeqRequest;
}

transition({I,SC,UC,SD,UD,UD_T,RU,RSC,RSD,RUSD,SC_RSC,SD_RSC,SD_RSD,UC_RSC,UC_RU,UD_RU,UD_RSD,UD_RSC,RUSC
            BUSY_INTR,BUSY_BLKD}, AllocPfRequest) {
  AllocateTBE_PfRequest;
}

transition({BUSY_INTR,BUSY_BLKD}, TagArrayRead) {TagArrayRead} {
  Pop_TriggerQueue;
  TagArrayRead;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, TagArrayWrite) {TagArrayWrite} {
  Pop_TriggerQueue;
  TagArrayWrite;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, DataArrayRead) {DataArrayRead} {
  Pop_TriggerQueue;
  DataArrayRead;
  ProcessNextState_ClearPending;
}

// goes to BUSY_INTR as we may need to accept snoops while waiting
// on potential replacement
transition({BUSY_INTR,BUSY_BLKD}, CheckCacheFill, BUSY_INTR) {
  CheckCacheFill;
  // CheckCacheFill either does Pop_TriggerQueue+ProcessNextState_ClearPending
  // or a stall depending on block availability
}

transition({BUSY_INTR,BUSY_BLKD}, DataArrayWrite) {DataArrayWrite} {
  Pop_TriggerQueue;
  DataArrayWrite;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, DataArrayWriteOnFill) {DataArrayWrite} {
  Pop_TriggerQueue;
  Profile_Fill;
  DataArrayWrite;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, ReadHitPipe) {
  Pop_TriggerQueue;
  ReadHitPipe;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, ReadMissPipe) {
  Pop_TriggerQueue;
  ReadMissPipe;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, WriteFEPipe) {
  Pop_TriggerQueue;
  WriteFEPipe;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, WriteBEPipe) {
  Pop_TriggerQueue;
  WriteBEPipe;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, FillPipe) {
  Pop_TriggerQueue;
  FillPipe;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, SnpSharedPipe) {
  Pop_TriggerQueue;
  SnpSharedPipe;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, SnpInvPipe) {
  Pop_TriggerQueue;
  SnpInvPipe;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR,BUSY_BLKD}, SnpOncePipe) {
  Pop_TriggerQueue;
  SnpOncePipe;
  ProcessNextState_ClearPending;
}

// ReadShared / ReadNotSharedDirty

transition(I, {ReadShared,ReadNotSharedDirty}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadShared_Miss;
  Allocate_DirEntry;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({RSC,RUSC}, {ReadShared,ReadNotSharedDirty}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadShared_HitUpstream_NoOwner;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD,SD,UC,SC}, {ReadShared,ReadNotSharedDirty}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadShared_Hit;
  Allocate_DirEntry;
  Profile_Hit;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD_RSC,SD_RSC,UC_RSC,SC_RSC,UD_RSD,SD_RSD}, {ReadShared,ReadNotSharedDirty}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadShared_Hit;
  Profile_Hit;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD_RU,UC_RU,RU,RSD,RUSD}, {ReadShared,ReadNotSharedDirty}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadShared_HitUpstream;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

// ReadOnce

transition(I, ReadOnce, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadOnce_Miss;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD,SD,UC,SC,UD_RSC,SD_RSC,UC_RSC,SC_RSC,UD_RSD,SD_RSD}, ReadOnce, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadOnce_Hit;
  Profile_Hit;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD_RU,UC_RU,RU,RSD,RUSD,RSC,RUSC}, ReadOnce, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadOnce_HitUpstream;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}


// ReadUnique

transition(I, {ReadUnique,ReadUnique_PoC}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadUnique_Miss;
  Allocate_DirEntry;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD,UC}, {ReadUnique,ReadUnique_PoC}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadUnique_Hit;
  Allocate_DirEntry;
  Profile_Hit;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD_RSC,UC_RSC,UD_RSD}, {ReadUnique,ReadUnique_PoC}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadUnique_Hit_InvUpstream;
  Profile_Hit;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD_RU,UC_RU,RU,RUSD,RUSC}, {ReadUnique,ReadUnique_PoC}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadUnique_HitUpstream;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({SC,SD}, ReadUnique_PoC, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadUnique_AutoUpgrade;
  Initiate_ReadUnique_Hit;
  Allocate_DirEntry;
  Profile_Hit;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({SC_RSC, SD_RSC, SD_RSD}, ReadUnique_PoC, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadUnique_AutoUpgrade;
  Initiate_ReadUnique_Hit_InvUpstream;
  Profile_Hit;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({RSC,RSD}, ReadUnique_PoC, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadUnique_AutoUpgrade;
  Initiate_ReadUnique_HitUpstream;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}


transition({SC,SD}, ReadUnique, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadUnique_Upgrade;
  Allocate_DirEntry;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({SC_RSC, SD_RSC, RSC, SD_RSD, RSD}, ReadUnique, BUSY_BLKD) {
  Initiate_Request;
  Initiate_ReadUnique_Upgrade;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

// CleanUnique

transition({I, SC, UC, SD, UD, RU, RSC, RSD, RUSD, RUSC,
            SC_RSC, SD_RSD, SD_RSC, UC_RSC, UC_RU, UD_RU, UD_RSD, UD_RSC}, CleanUnique, BUSY_BLKD) {
  Initiate_Request;
  Initiate_CleanUnique;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

// WriteUniquePtl

transition({UD,UD_RU,UD_RSD,UD_RSC,UC,UC_RU,UC_RSC},
           {WriteUnique, WriteUniquePtl_PoC, WriteUniqueFull_PoC, WriteUniqueFull_PoC_Alloc},
           BUSY_BLKD) {
  Initiate_Request;
  Initiate_WriteUnique_LocalWrite;
  Profile_Hit;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({SD, SD_RSD, SD_RSC, SC, SC_RSC},
           {WriteUniquePtl_PoC, WriteUniqueFull_PoC, WriteUniqueFull_PoC_Alloc},
           BUSY_BLKD) {
  Initiate_Request;
  Initiate_WriteUnique_LocalWrite;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({RSC,RSD,RUSD,RUSC,RU,I}, WriteUniqueFull_PoC_Alloc, BUSY_BLKD) {
  Initiate_Request;
  Initiate_WriteUnique_LocalWrite;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({SD, SD_RSD, SD_RSC, SC, SC_RSC},
           {WriteUnique}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_WriteUnique_LocalWrite_AfterUpgrade;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({RSD,RUSD,RUSC,RU}, {WriteUniquePtl_PoC, WriteUniqueFull_PoC}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_WriteUnique_Writeback;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({RSC,I}, {WriteUniquePtl_PoC, WriteUniqueFull_PoC}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_WriteUnique_PartialWrite;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({RSC,RSD,RUSD,RUSC,RU,I}, WriteUnique, BUSY_BLKD) {
  Initiate_Request;
  Initiate_WriteUnique_Forward;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}


// Load / Store from sequencer & Prefetch from prefetcher

transition({UD,UD_T,SD,UC,SC}, Load, BUSY_BLKD) {
  Initiate_Request;
  Initiate_LoadHit;
  Profile_Hit;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

// Prefetch hits if either this cache or one of its upstream caches has a
// valid block.
// In some states, using the normal hit path for a prefetch will deallocate
// the local cache entry at the end since our data is stale. If the cache is
// inclusive for unique data we need to keep the block, so just bypass the
// normal path.
transition({UD,UD_T,SD,UC,SC,RU,RSC,RSD,RUSD,SC_RSC,SD_RSC,SD_RSD,UC_RSC,UC_RU,UD_RU,UD_RSD,UD_RSC}, Prefetch) {
  Callback_ExpressPrefetchHit;
  Pop_ReqRdyQueue;
}

transition(BUSY_BLKD, LoadHit) {
  Pop_TriggerQueue;
  Callback_LoadHit;
  ProcessNextState_ClearPending;
}

transition({UD,UD_T,UC}, Store, BUSY_BLKD) {
  Initiate_Request;
  Initiate_StoreHit;
  Profile_Hit;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition(BUSY_BLKD, StoreHit) {
  Pop_TriggerQueue;
  Callback_StoreHit;
  ProcessNextState_ClearPending;
}

transition(I, {Load,Prefetch}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_LoadMiss;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition(I, Store, BUSY_BLKD) {
  Initiate_Request;
  Initiate_StoreMiss;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({SD,SC}, Store, BUSY_BLKD) {
  Initiate_Request;
  Initiate_StoreUpgrade;
  Profile_Miss;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

// write timeout

transition(UD_T, UseTimeout, UD) {
  Unset_Timeout_Cache;
}

transition({BUSY_BLKD,BUSY_INTR}, UseTimeout) {
  Unset_Timeout_TBE;
}

// Evict from Upstream

transition({UD_RSC,SD_RSC,UC_RSC,SC_RSC,RSC,RSD,RUSD,RUSC,UD_RSD,SD_RSD}, Evict, BUSY_BLKD) {
  Initiate_Request;
  Initiate_Evict;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD, UD_RSC, SD_RSC, UC_RSC, SC_RSC, UD_RU, UC_RU, UD_RSD, SD_RSD, RU, RSC, RSD, RUSD, RUSC, SD, UC, SC, I},
            Evict_Stale) {
  Initiate_Request_Stale;
  Send_CompI_Stale;
  Finalize_DeallocateRequest;
  Pop_ReqRdyQueue;
}

// WriteBack from upstream

transition({UD_RU, UC_RU, RU, UD_RSD, SD_RSD, RSD, RUSD}, {WriteBackFull, WriteCleanFull}, BUSY_BLKD) {
  Initiate_Request;
  Initiate_CopyBack;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD_RU, UC_RU, RU}, WriteEvictFull, BUSY_BLKD) {
  Initiate_Request;
  Initiate_CopyBack;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

transition({UD_RSC, UC_RSC, SC_RSC, UD, RU, RSD, RUSD, RUSC, UD_RSD, SD_RSD, RSC, UD_RU, UC_RU, SD, UC, SC, I},
            {WriteBackFull_Stale, WriteEvictFull_Stale, WriteCleanFull_Stale}, BUSY_BLKD) {
  Initiate_Request_Stale;
  Initiate_CopyBack_Stale;
  Pop_ReqRdyQueue;
  ProcessNextState;
}

// Cache Replacement

// When in UD_RU,UC_RU,UD_RSD,SD_RSD we also just drop the line since an upstream
// cache has an up-to-data line that it will either WriteBack or WriteEvict
transition({SC,UC,SC_RSC,UC_RSC,
            UD_RU,UC_RU,UD_RSD,SD_RSD}, LocalHN_Eviction, BUSY_BLKD) {ReplTBEAvailable} {
  Initiate_Replacement;
  Initiate_Replacement_JustDrop;
  Profile_Eviction;
  Deallocate_CacheBlock;
  Pop_ReplTriggerQueue;
  ProcessNextState;
}

transition({UD,SD,UD_RSC,SD_RSC}, LocalHN_Eviction, BUSY_BLKD) {ReplTBEAvailable} {
  Initiate_Replacement;
  Initiate_Replacement_WB;
  Profile_Eviction;
  Deallocate_CacheBlock;
  Pop_ReplTriggerQueue;
  ProcessNextState;
}

transition(SC, Local_Eviction, BUSY_BLKD) {ReplTBEAvailable} {
  Initiate_Replacement;
  Initiate_Replacement_Evict;
  Profile_Eviction;
  Deallocate_CacheBlock;
  Pop_ReplTriggerQueue;
  ProcessNextState;
}

transition({UD,SD,UC}, Local_Eviction, BUSY_BLKD) {ReplTBEAvailable} {
  Initiate_Replacement;
  Initiate_Replacement_WB;
  Profile_Eviction;
  Deallocate_CacheBlock;
  Pop_ReplTriggerQueue;
  ProcessNextState;
}

transition({UD_RU,UC_RU,UD_RSD,SD_RSD,SC_RSC,UC_RSC}, Local_Eviction, BUSY_BLKD) {ReplTBEAvailable} {
  Initiate_Replacement;
  Initiate_Replacement_JustDrop;
  Profile_Eviction;
  Deallocate_CacheBlock;
  Pop_ReplTriggerQueue;
  ProcessNextState;
}

transition({UD_RSC,SD_RSC}, Local_Eviction, BUSY_BLKD) {ReplTBEAvailable} {
  Initiate_Replacement;
  Initiate_Replacement_WB;
  Profile_Eviction;
  Deallocate_CacheBlock;
  Pop_ReplTriggerQueue;
  ProcessNextState;
}

transition({UD_RSC,SD_RSC,UC_RSC,UD_RU,UC_RU,UD_RSD}, Global_Eviction, BUSY_BLKD) {ReplTBEAvailable} {
  Initiate_Replacement;
  Initiate_Replacement_WB_BackInvalidate;
  Profile_Eviction;
  Deallocate_CacheBlock;
  Deallocate_DirEntry;
  Pop_ReplTriggerQueue;
  ProcessNextState;
}

transition(SC_RSC, Global_Eviction, BUSY_BLKD) {ReplTBEAvailable} {
  Initiate_Replacement;
  Initiate_Replacement_Evict_BackInvalidte;
  Profile_Eviction;
  Deallocate_CacheBlock;
  Deallocate_DirEntry;
  Pop_ReplTriggerQueue;
  ProcessNextState;
}

// This could happen if enqueued the eviction when the line was busy
// or couldn't handle it immediately due to no TBE available
transition({RU,RSC,RSD,RUSD,I}, {Local_Eviction, LocalHN_Eviction}) {
  Pop_ReplTriggerQueue;
}
transition(I, Global_Eviction) {
  Pop_ReplTriggerQueue;
}

// Snoops

// SnpCleanInvalid/SnpUnique/SnpUniqueFwd
// All invalidating snoops have a simular behavior

transition({UD,SD,UC,SC,UD_RSC,SD_RSC,UC_RSC,UD_RU,UC_RU,RU,RUSD,RUSC,RSD,UD_RSD,SD_RSD,SC_RSC,RSC},
           {SnpUnique,SnpUniqueFwd,SnpCleanInvalid}, BUSY_BLKD) {
  Initiate_Snoop;
  Initiate_InvalidationSnoop;
  Profile_Eviction;
  Pop_SnoopRdyQueue;
  ProcessNextState;
}

transition(BUSY_INTR, {SnpUnique,SnpUniqueFwd,SnpCleanInvalid}, BUSY_BLKD) {
  Initiate_Snoop_Hazard;
  Initiate_InvalidationSnoop;
  Profile_Eviction;
  Pop_SnoopRdyQueue;
  ProcessNextState;
}

// SnpShared / SnpNotSharedDirty

transition({UD,UD_RSC,SD,SD_RSC,UC,UC_RSC,UD_RU,UC_RU,RU,UD_RSD,SD_RSD,RSD,RUSD,RUSC},
           {SnpShared,SnpSharedFwd,SnpNotSharedDirtyFwd}, BUSY_BLKD) {
  Initiate_Snoop;
  Initiate_SnpShared;
  Pop_SnoopRdyQueue;
  ProcessNextState;
}

transition({SC, SC_RSC, RSC}, {SnpSharedFwd, SnpNotSharedDirtyFwd}, BUSY_BLKD) {
  Initiate_Snoop;
  Initiate_SnpShared;
  Pop_SnoopRdyQueue;
  ProcessNextState;
}

transition(BUSY_INTR, {SnpShared,SnpSharedFwd,SnpNotSharedDirtyFwd}, BUSY_BLKD) {
  Initiate_Snoop_Hazard;
  Initiate_SnpShared;
  Pop_SnoopRdyQueue;
  ProcessNextState;
}

// SnpOnce
transition({UD,UD_T,UD_RSC,UD_RU,UD_RSD,SD,SD_RSC,SD_RSD,UC,UC_RSC,UC_RU,SC,SC_RSC,RU,RSC,RSD,RUSD,RUSC},
           {SnpOnce,SnpOnceFwd}, BUSY_BLKD) {
  Initiate_Snoop;
  Initiate_SnpOnce;
  Pop_SnoopRdyQueue;
  ProcessNextState;
}

transition(BUSY_INTR, {SnpOnce,SnpOnceFwd}, BUSY_BLKD) {
  Initiate_Snoop_Hazard;
  Initiate_SnpOnce;
  Pop_SnoopRdyQueue;
  ProcessNextState;
}


// Stalls

transition({BUSY_BLKD,BUSY_INTR},
            {ReadShared, ReadNotSharedDirty, ReadUnique, ReadUnique_PoC,
            ReadOnce, CleanUnique,
            Load, Store, Prefetch,
            WriteBackFull, WriteBackFull_Stale,
            WriteEvictFull, WriteEvictFull_Stale,
            WriteCleanFull, WriteCleanFull_Stale,
            Evict, Evict_Stale,
            WriteUnique,WriteUniquePtl_PoC,
            WriteUniqueFull_PoC,WriteUniqueFull_PoC_Alloc}) {
  StallRequest;
}

transition({BUSY_BLKD,BUSY_INTR},
           {Global_Eviction, Local_Eviction, LocalHN_Eviction}) {
  StallLocalEviction;
}

// Kill the timer and try again as a snoop may be pending as well
transition(UD_T, {Global_Eviction, Local_Eviction, LocalHN_Eviction}, UD) {
  Unset_Timeout_Cache;
  Pop_ReplTriggerQueue;
}

transition(BUSY_BLKD,
            {SnpCleanInvalid,SnpShared,SnpUnique,SnpSharedFwd,SnpUniqueFwd,
            SnpNotSharedDirtyFwd, SnpOnce}) {
  StallSnoop;
}

transition({BUSY_BLKD,BUSY_INTR}, SnpStalled) {
  StallSnoop;
}

transition(UD_T, {SnpCleanInvalid,SnpShared,SnpUnique,SnpSharedFwd,SnpUniqueFwd,
                  SnpNotSharedDirtyFwd}) {
  StallSnoop_NoTBE;
}

transition({BUSY_BLKD,BUSY_INTR}, ActionStalledOnHazard) {
  StallActionOnHazard;
}

// Trigger-specifc transitions

transition(BUSY_BLKD, SendWriteBackOrWriteEvict, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_WriteBackOrWriteEvict;
  Profile_OutgoingStart;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendWriteClean, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_WriteCleanFull;
  Profile_OutgoingStart;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendWriteUnique, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_WriteUnique;
  Profile_OutgoingStart;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendWriteNoSnp, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_WriteNoSnp;
  Profile_OutgoingStart;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendWriteNoSnpPartial, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_WriteNoSnp_Partial;
  Profile_OutgoingStart;
  ProcessNextState_ClearPending;
}


transition(BUSY_BLKD, SendEvict, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_Evict;
  Profile_OutgoingStart;
  ProcessNextState_ClearPending;
}

// May get here from BUSY_INTR
transition({BUSY_BLKD, BUSY_INTR}, SendCompData, BUSY_BLKD) {
  Pop_TriggerQueue;
  Send_CompData;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendWBData) {
  Pop_TriggerQueue;
  Send_WBData;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendWUData) {
  Pop_TriggerQueue;
  Send_WUData;
  CheckWUComp;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendWUDataCB) {
  Pop_TriggerQueue;
  Callback_WriteUnique;
  Send_WUData;
  CheckWUComp;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendInvSnpResp) {
  Pop_TriggerQueue;
  Send_InvSnpResp;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpData) {
  Pop_TriggerQueue;
  Send_SnpRespData;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpUniqueFwdCompData) {
  Pop_TriggerQueue;
  Send_CompData_SnpUniqueFwd;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpSharedFwdCompData) {
  Pop_TriggerQueue;
  Send_CompData_SnpSharedFwd;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpNotSharedDirtyFwdCompData) {
  Pop_TriggerQueue;
  Send_CompData_SnpNSDFwd;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpOnceFwdCompData) {
  Pop_TriggerQueue;
  Send_CompData_SnpOnceFwd;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpFwdedData) {
  Pop_TriggerQueue;
  Send_SnpRespDataFwded;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpFwdedResp) {
  Pop_TriggerQueue;
  Send_FwdSnpResp;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendCompAck) {
  Pop_TriggerQueue;
  Send_CompAck;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpIResp) {
  Pop_TriggerQueue;
  Send_SnpRespI;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendCompIResp) {
  Pop_TriggerQueue;
  Send_CompI;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendCompUCResp) {
  Pop_TriggerQueue;
  Send_CompUC;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendRespSepData) {
  Pop_TriggerQueue;
  Send_RespSepData;
  ProcessNextState_ClearPending;
}

transition({BUSY_INTR, BUSY_BLKD}, WaitCompAck) {
  Pop_TriggerQueue;
  ExpectCompAck;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, RestoreFromHazard, BUSY_INTR) {
  Pop_TriggerQueue;
  RestoreFromHazard;
}

transition(BUSY_BLKD, SendReadShared, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_ReadShared;
  Profile_OutgoingStart;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendReadOnce, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_ReadOnce;
  Profile_OutgoingStart;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendReadUnique, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_ReadUnique;
  Profile_OutgoingStart;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendCleanUnique, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_CleanUnique;
  Profile_OutgoingStart;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendReadNoSnp, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_ReadNoSnp;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendReadNoSnpDMT, BUSY_INTR) {DestinationAvailable} {
  Pop_TriggerQueue;
  Send_ReadNoSnpDMT;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpShared) {
  Pop_TriggerQueue;
  Send_SnpShared;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpSharedFwdToOwner) {
  Pop_TriggerQueue;
  Send_SnpSharedFwd_ToOwner;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpSharedFwdToSharer) {
  Pop_TriggerQueue;
  Send_SnpSharedFwd_ToSharer;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpOnceFwd) {
  Pop_TriggerQueue;
  Send_SnpOnceFwd;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpOnce) {
  Pop_TriggerQueue;
  Send_SnpOnce;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpUnique) {
  Pop_TriggerQueue;
  Send_SnpUnique;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpUniqueRetToSrc) {
  Pop_TriggerQueue;
  Send_SnpUnique_RetToSrc;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpUniqueFwd) {
  Pop_TriggerQueue;
  Send_SnpUniqueFwd;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpCleanInvalid) {
  Pop_TriggerQueue;
  Send_SnpCleanInvalid;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendSnpCleanInvalidNoReq) {
  Pop_TriggerQueue;
  Send_SnpCleanInvalid_NoReq;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendCompDBIDResp) {
  Pop_TriggerQueue;
  Send_CompDBIDResp;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendCompDBIDResp_WU) {
  Pop_TriggerQueue;
  ExpectNCBWrData;
  Send_CompDBIDResp;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendDBIDResp_WU) {
  Pop_TriggerQueue;
  ExpectNCBWrData;
  Send_DBIDResp;
  ProcessNextState_ClearPending;
}

transition({BUSY_BLKD,BUSY_INTR}, SendComp_WU) {
  Pop_TriggerQueue;
  Send_Comp_WU;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, SendCompDBIDRespStale) {
  Pop_TriggerQueue;
  Send_CompDBIDResp_Stale;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, MaintainCoherence) {
  Pop_TriggerQueue;
  Initiate_MaitainCoherence;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, FinishCleanUnique) {
  Pop_TriggerQueue;
  Finish_CleanUnique;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, CheckUpgrade_FromStore) {
  Pop_TriggerQueue;
  Callback_Miss; // note: Callback happens only if tbe.dataValid
  CheckUpgrade_FromStore;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, CheckUpgrade_FromCU) {
  Pop_TriggerQueue;
  CheckUpgrade_FromCU;
  ProcessNextState_ClearPending;
}

transition(BUSY_BLKD, CheckUpgrade_FromRU) {
  Pop_TriggerQueue;
  CheckUpgrade_FromRU;
  ProcessNextState_ClearPending;
}


// Generic send/receive transitions

// waiting for data
transition(BUSY_BLKD,
           {CBWrData_I,CBWrData_SC,CBWrData_SD_PD,CBWrData_UC,CBWrData_UD_PD}) {
  Receive_ReqDataResp;
  UpdateDirState_FromReqDataResp;
  UpdateDataState_FromReqDataResp;
  Pop_DataInQueue;
  ProcessNextState;
}

// could be waiting for both data and CompDBIDResp on a WriteUnique
transition({BUSY_BLKD,BUSY_INTR}, NCBWrData) {
  Receive_ReqDataResp;
  UpdateDataState_FromWUDataResp;
  Pop_DataInQueue;
  ProcessNextState;
}

transition(BUSY_BLKD,
           {SnpRespData_I_PD,SnpRespData_I,SnpRespData_SC_PD,
            SnpRespData_SC,SnpRespData_SD,SnpRespData_UD,
            SnpRespData_SC_Fwded_SC,SnpRespData_SC_Fwded_SD_PD,
            SnpRespData_SC_PD_Fwded_SC,SnpRespData_I_Fwded_SD_PD,
            SnpRespData_I_PD_Fwded_SC,SnpRespData_I_Fwded_SC}) {
  Receive_SnpDataResp;
  UpdateDirState_FromSnpDataResp;
  UpdateDataState_FromSnpDataResp;
  Pop_DataInQueue;
  ProcessNextState;
}

transition({BUSY_BLKD,BUSY_INTR}, RespSepData, BUSY_BLKD) {
  Receive_RespSepData;
  Pop_RespInQueue;
  ProcessNextState;
}

transition({BUSY_BLKD,BUSY_INTR}, DataSepResp_UC, BUSY_BLKD) {
  Receive_ReqDataResp;
  UpdateDataState_FromReqDataResp;
  Callback_Miss;
  Profile_OutgoingEnd_DataResp;
  Pop_DataInQueue;
  ProcessNextState;
}

transition({BUSY_BLKD,BUSY_INTR},
            {CompData_I,CompData_SC,CompData_SD_PD,CompData_UC,CompData_UD_PD},
            BUSY_BLKD) {
  Receive_RespSepDataFromCompData;
  Receive_ReqDataResp;
  UpdateDataState_FromReqDataResp;
  Callback_Miss;
  Profile_OutgoingEnd_DataResp;
  Pop_DataInQueue;
  ProcessNextState;
}

transition(BUSY_INTR, ReadReceipt, BUSY_BLKD) {
  Receive_ReadReceipt;
  Pop_RespInQueue;
  ProcessNextState;
}

// Retry handling

transition(BUSY_INTR, {RetryAck, RetryAck_PoC}) {
  Receive_RetryAck;
  Pop_RespInQueue;
  ProcessNextState;
}

transition(BUSY_INTR, {PCrdGrant, PCrdGrant_PoC}) {
  Receive_PCrdGrant;
  Pop_RespInQueue;
  ProcessNextState;
}

// RetryAck/PCrdGrant on BUSY_BLKD is only expected in a PoC/HN when waiting
// for CompAck after sending down a request with DMT enabled. Handle the same
// as BUSY_INTR

transition(BUSY_BLKD, RetryAck_PoC) {
  Receive_RetryAck;
  Pop_RespInQueue;
  ProcessNextState;
}

transition(BUSY_BLKD, PCrdGrant_PoC) {
  Receive_PCrdGrant;
  Pop_RespInQueue;
  ProcessNextState;
}

// RetryAck/PCrdGrant received during a snoop hazard may arrive in both
// BUSY_BLKD and BUSY_INTR
transition({BUSY_INTR,BUSY_BLKD}, {RetryAck_Hazard, RetryAck_PoC_Hazard}) {
  Receive_RetryAck_Hazard;
  Pop_RespInQueue;
  ProcessNextState;
}

transition({BUSY_INTR,BUSY_BLKD}, {PCrdGrant_Hazard, PCrdGrant_PoC_Hazard}) {
  Receive_PCrdGrant_Hazard;
  Pop_RespInQueue;
  ProcessNextState;
}

// Resend the request after RetryAck+PCrdGrant received

transition({BUSY_INTR,BUSY_BLKD}, DoRetry) {
  Send_Retry;
  Pop_RetryTriggerQueue;
}

transition({BUSY_INTR,BUSY_BLKD}, DoRetry_Hazard) {
  Send_Retry_Hazard;
  Pop_RetryTriggerQueue;
}

// waiting for completion ack
transition({BUSY_BLKD,BUSY_INTR}, CompAck) {
  Receive_ReqResp;
  UpdateDirState_FromReqResp;
  Pop_RespInQueue;
  ProcessNextState;
}

transition(BUSY_BLKD,
           {SnpResp_I,SnpResp_SC,
            SnpResp_I_Fwded_UC,SnpResp_I_Fwded_UD_PD,
            SnpResp_SC_Fwded_SC,SnpResp_SC_Fwded_SD_PD,
            SnpResp_UC_Fwded_I,SnpResp_UD_Fwded_I,
            SnpResp_SC_Fwded_I,SnpResp_SD_Fwded_I}) {
  Receive_SnpResp;
  UpdateDirState_FromSnpResp;
  Pop_RespInQueue;
  ProcessNextState;
}

// waiting for WB or evict ack
transition(BUSY_INTR,
           {CompDBIDResp,Comp_I}, BUSY_BLKD) {
  Receive_ReqResp;
  Profile_OutgoingEnd_DatalessResp;
  Pop_RespInQueue;
  ProcessNextState;
}

// currently this happens after a CleanUnique
transition(BUSY_INTR, Comp_UC, BUSY_BLKD) {
  Receive_ReqResp;
  UpdateDataState_FromCUResp;
  Profile_OutgoingEnd_DatalessResp;
  Pop_RespInQueue;
  ProcessNextState;
}

// alternative flow for WU with separate Comp
transition(BUSY_INTR, DBIDResp, BUSY_BLKD) {
  Receive_ReqResp;
  Receive_ReqResp_WUNeedComp;
  Pop_RespInQueue;
  ProcessNextState;
}
transition(BUSY_BLKD, Comp) {
  Receive_ReqResp_WUComp;
  Profile_OutgoingEnd_DatalessResp;
  Pop_RespInQueue;
  ProcessNextState;
}

transition(BUSY_BLKD, TX_Data) {
  Pop_TriggerQueue;
  Send_Data;
  ProcessNextState_ClearPending;
}

// Finalization transition

transition({BUSY_BLKD,BUSY_INTR}, Final, *) {
  Pop_TriggerQueue;
  Finalize_UpdateCacheFromTBE;
  Finalize_UpdateDirectoryFromTBE;
  Finalize_DeallocateRequest;
}