src/mem/packet.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2011-2019, 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.
  *
  * Copyright (c) 2006 The Regents of The University of Michigan
  * Copyright (c) 2010,2015 Advanced Micro Devices, Inc.
  * 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.
  */

 /**
  * @file
  * Definition of the Packet Class, a packet is a transaction occuring
  * between a single level of the memory heirarchy (ie L1->L2).
  */

 #include "mem/packet.hh"

 #include <algorithm>
 #include <cstring>
 #include <iostream>
 #include <sstream>
 #include <string>

 #include "base/cprintf.hh"
 #include "base/logging.hh"
 #include "base/trace.hh"
 #include "mem/packet_access.hh"
 #include "sim/bufval.hh"

 namespace gem5
 {

 const MemCmd::CommandInfo
 MemCmd::commandInfo[] =
 {
     /* InvalidCmd */
     { {}, InvalidCmd, "InvalidCmd" },
     /* ReadReq - Read issued by a non-caching agent such as a CPU or
      * device, with no restrictions on alignment. */
     { {IsRead, IsRequest, NeedsResponse}, ReadResp, "ReadReq" },
     /* ReadResp */
     { {IsRead, IsResponse, HasData}, InvalidCmd, "ReadResp" },
     /* ReadRespWithInvalidate */
     { {IsRead, IsResponse, HasData, IsInvalidate},
             InvalidCmd, "ReadRespWithInvalidate" },
     /* WriteReq */
     { {IsWrite, NeedsWritable, IsRequest, NeedsResponse, HasData},
             WriteResp, "WriteReq" },
     /* WriteResp */
     { {IsWrite, IsResponse}, InvalidCmd, "WriteResp" },
     /* WriteCompleteResp - The WriteCompleteResp command is needed
      * because in the GPU memory model we use a WriteResp to indicate
      * that a write has reached the cache controller so we can free
      * resources at the coalescer. Later, when the write succesfully
      * completes we send a WriteCompleteResp to the CU so its wait
      * counters can be updated. Wait counters in the CU is how memory
      * dependences are handled in the GPU ISA. */
     { {IsWrite, IsResponse}, InvalidCmd, "WriteCompleteResp" },
     /* WritebackDirty */
     { {IsWrite, IsRequest, IsEviction, HasData, FromCache},
             InvalidCmd, "WritebackDirty" },
     /* WritebackClean - This allows the upstream cache to writeback a
      * line to the downstream cache without it being considered
      * dirty. */
     { {IsWrite, IsRequest, IsEviction, HasData, FromCache},
             InvalidCmd, "WritebackClean" },
     /* WriteClean - This allows a cache to write a dirty block to a memory
        below without evicting its copy. */
     { {IsWrite, IsRequest, HasData, FromCache}, InvalidCmd, "WriteClean" },
     /* CleanEvict */
     { {IsRequest, IsEviction, FromCache}, InvalidCmd, "CleanEvict" },
     /* SoftPFReq */
     { {IsRead, IsRequest, IsSWPrefetch, NeedsResponse},
             SoftPFResp, "SoftPFReq" },
     /* SoftPFExReq */
     { {IsRead, NeedsWritable, IsInvalidate, IsRequest,
            IsSWPrefetch, NeedsResponse}, SoftPFResp, "SoftPFExReq" },
     /* HardPFReq */
     { {IsRead, IsRequest, IsHWPrefetch, NeedsResponse, FromCache},
             HardPFResp, "HardPFReq" },
     /* SoftPFResp */
     { {IsRead, IsResponse, IsSWPrefetch, HasData}, InvalidCmd, "SoftPFResp" },
     /* HardPFResp */
     { {IsRead, IsResponse, IsHWPrefetch, HasData}, InvalidCmd, "HardPFResp" },
     /* WriteLineReq */
     { {IsWrite, NeedsWritable, IsRequest, NeedsResponse, HasData},
             WriteResp, "WriteLineReq" },
     /* UpgradeReq */
     { {IsInvalidate, NeedsWritable, IsUpgrade, IsRequest, NeedsResponse,
             FromCache}, UpgradeResp, "UpgradeReq" },
     /* SCUpgradeReq: response could be UpgradeResp or UpgradeFailResp */
     { {IsInvalidate, NeedsWritable, IsUpgrade, IsLlsc,
            IsRequest, NeedsResponse, FromCache},
             UpgradeResp, "SCUpgradeReq" },
     /* UpgradeResp */
     { {IsUpgrade, IsResponse}, InvalidCmd, "UpgradeResp" },
     /* SCUpgradeFailReq: generates UpgradeFailResp but still gets the data */
     { {IsRead, NeedsWritable, IsInvalidate,
            IsLlsc, IsRequest, NeedsResponse, FromCache},
             UpgradeFailResp, "SCUpgradeFailReq" },
     /* UpgradeFailResp - Behaves like a ReadExReq, but notifies an SC
      * that it has failed, acquires line as Dirty*/
     { {IsRead, IsResponse, HasData}, InvalidCmd, "UpgradeFailResp" },
     /* ReadExReq - Read issues by a cache, always cache-line aligned,
      * and the response is guaranteed to be writeable (exclusive or
      * even modified} */
     { {IsRead, NeedsWritable, IsInvalidate, IsRequest, NeedsResponse,
           FromCache}, ReadExResp, "ReadExReq" },
     /* ReadExResp - Response matching a read exclusive, as we check
      * the need for exclusive also on responses */
     { {IsRead, IsResponse, HasData}, InvalidCmd, "ReadExResp" },
     /* ReadCleanReq - Read issued by a cache, always cache-line
      * aligned, and the response is guaranteed to not contain dirty data
      * (exclusive or shared}.*/
     { {IsRead, IsRequest, NeedsResponse, FromCache},
             ReadResp, "ReadCleanReq" },
     /* ReadSharedReq - Read issued by a cache, always cache-line
      * aligned, response is shared, possibly exclusive, owned or even
      * modified. */
     { {IsRead, IsRequest, NeedsResponse, FromCache},
             ReadResp, "ReadSharedReq" },
     /* LoadLockedReq: note that we use plain ReadResp as response, so that
      *                we can also use ReadRespWithInvalidate when needed */
     { {IsRead, IsLlsc, IsRequest, NeedsResponse},
             ReadResp, "LoadLockedReq" },
     /* StoreCondReq */
     { {IsWrite, NeedsWritable, IsLlsc,
            IsRequest, NeedsResponse, HasData},
             StoreCondResp, "StoreCondReq" },
     /* StoreCondFailReq: generates failing StoreCondResp */
     { {IsWrite, NeedsWritable, IsLlsc, IsRequest, NeedsResponse, HasData},
             StoreCondResp, "StoreCondFailReq" },
     /* StoreCondResp */
     { {IsWrite, IsLlsc, IsResponse},
             InvalidCmd, "StoreCondResp" },
     /* LockedRMWReadReq */
     { {IsRead, IsLockedRMW, NeedsWritable, IsRequest, NeedsResponse},
             LockedRMWReadResp, "LockedRMWReadReq" },
     /* LockedRMWReadResp */
     { {IsRead, IsLockedRMW, NeedsWritable, IsResponse, HasData},
             InvalidCmd, "LockedRMWReadResp" },
     /* LockedRMWWriteReq */
     { {IsWrite, IsLockedRMW, NeedsWritable, IsRequest, NeedsResponse,
            HasData}, LockedRMWWriteResp, "LockedRMWWriteReq" },
     /* LockedRMWWriteResp */
     { {IsWrite, IsLockedRMW, NeedsWritable, IsResponse},
             InvalidCmd, "LockedRMWWriteResp" },
     /* SwapReq -- for Swap ldstub type operations */
     { {IsRead, IsWrite, NeedsWritable, IsRequest, HasData, NeedsResponse},
         SwapResp, "SwapReq" },
     /* SwapResp -- for Swap ldstub type operations */
     { {IsRead, IsWrite, IsResponse, HasData}, InvalidCmd, "SwapResp" },
     { {}, InvalidCmd, "Deprecated_MessageReq" },
     { {}, InvalidCmd, "Deprecated_MessageResp" },
     /* MemFenceReq -- for synchronization requests */
     {{IsRequest, NeedsResponse}, MemFenceResp, "MemFenceReq"},
     /* MemSyncReq */
     {{IsRequest, NeedsResponse}, MemSyncResp, "MemSyncReq"},
     /* MemSyncResp */
     {{IsResponse}, InvalidCmd, "MemSyncResp"},
     /* MemFenceResp -- for synchronization responses */
     {{IsResponse}, InvalidCmd, "MemFenceResp"},
     /* Cache Clean Request -- Update with the latest data all existing
        copies of the block down to the point indicated by the
        request */
     { {IsRequest, IsClean, NeedsResponse, FromCache},
       CleanSharedResp, "CleanSharedReq" },
     /* Cache Clean Response - Indicates that all caches up to the
        specified point of reference have a up-to-date copy of the
        cache block or no copy at all */
     { {IsResponse, IsClean}, InvalidCmd, "CleanSharedResp" },
     /* Cache Clean and Invalidate Request -- Invalidate all existing
        copies down to the point indicated by the request */
     { {IsRequest, IsInvalidate, IsClean, NeedsResponse, FromCache},
       CleanInvalidResp, "CleanInvalidReq" },
      /* Cache Clean and Invalidate Respose -- Indicates that no cache
         above the specified point holds the block and that the block
         was written to a memory below the specified point. */
     { {IsResponse, IsInvalidate, IsClean},
       InvalidCmd, "CleanInvalidResp" },
     /* InvalidDestError  -- packet dest field invalid */
     { {IsResponse, IsError}, InvalidCmd, "InvalidDestError" },
     /* BadAddressError   -- memory address invalid */
     { {IsResponse, IsError}, InvalidCmd, "BadAddressError" },
     /* ReadError -- packet dest unable to fulfill read command */
     { {IsRead, IsResponse, IsError}, InvalidCmd, "ReadError" },
     /* WriteError -- packet dest unable to fulfill write command */
     { {IsWrite, IsResponse, IsError}, InvalidCmd, "WriteError" },
     /* FunctionalReadError */
     { {IsRead, IsResponse, IsError}, InvalidCmd, "FunctionalReadError" },
     /* FunctionalWriteError */
     { {IsWrite, IsResponse, IsError}, InvalidCmd, "FunctionalWriteError" },
     /* PrintReq */
     { {IsRequest, IsPrint}, InvalidCmd, "PrintReq" },
     /* Flush Request */
     { {IsRequest, IsFlush, NeedsWritable}, InvalidCmd, "FlushReq" },
     /* Invalidation Request */
     { {IsInvalidate, IsRequest, NeedsWritable, NeedsResponse, FromCache},
       InvalidateResp, "InvalidateReq" },
     /* Invalidation Response */
     { {IsInvalidate, IsResponse},
       InvalidCmd, "InvalidateResp" },
       // hardware transactional memory
     { {IsRead, IsRequest, NeedsResponse}, HTMReqResp, "HTMReq" },
     { {IsRead, IsResponse}, InvalidCmd, "HTMReqResp" },
     { {IsRead, IsRequest}, InvalidCmd, "HTMAbort" },
     { {IsRequest}, InvalidCmd, "TlbiExtSync" },
 };

 AddrRange
 Packet::getAddrRange() const
 {
     return RangeSize(getAddr(), getSize());
 }

 bool
 Packet::trySatisfyFunctional(Printable *obj, Addr addr, bool is_secure, int size,
                         uint8_t *_data)
 {
     const Addr func_start = getAddr();
     const Addr func_end   = getAddr() + getSize() - 1;
     const Addr val_start  = addr;
     const Addr val_end    = val_start + size - 1;

     if (is_secure != _isSecure || func_start > val_end ||
         val_start > func_end) {
         // no intersection
         return false;
     }

     // check print first since it doesn't require data
     if (isPrint()) {
         assert(!_data);
         safe_cast<PrintReqState*>(senderState)->printObj(obj);
         return false;
     }

     // we allow the caller to pass NULL to signify the other packet
     // has no data
     if (!_data) {
         return false;
     }

     const Addr val_offset = func_start > val_start ?
         func_start - val_start : 0;
     const Addr func_offset = func_start < val_start ?
         val_start - func_start : 0;
     const Addr overlap_size = std::min(val_end, func_end)+1 -
         std::max(val_start, func_start);

     if (isRead()) {
         std::memcpy(getPtr<uint8_t>() + func_offset,
                _data + val_offset,
                overlap_size);

         // initialise the tracking of valid bytes if we have not
         // used it already
         if (bytesValid.empty())
             bytesValid.resize(getSize(), false);

         // track if we are done filling the functional access
         bool all_bytes_valid = true;

         int i = 0;

         // check up to func_offset
         for (; all_bytes_valid && i < func_offset; ++i)
             all_bytes_valid &= bytesValid[i];

         // update the valid bytes
         for (i = func_offset; i < func_offset + overlap_size; ++i)
             bytesValid[i] = true;

         // check the bit after the update we just made
         for (; all_bytes_valid && i < getSize(); ++i)
             all_bytes_valid &= bytesValid[i];

         return all_bytes_valid;
     } else if (isWrite()) {
         std::memcpy(_data + val_offset,
                getConstPtr<uint8_t>() + func_offset,
                overlap_size);
     } else {
         panic("Don't know how to handle command %s\n", cmdString());
     }

     // keep going with request by default
     return false;
 }

 void
 Packet::copyResponderFlags(const PacketPtr pkt)
 {
     assert(isRequest());
     // If we have already found a responder, no other cache should
     // commit to responding
     assert(!pkt->cacheResponding() || !cacheResponding());
     flags.set(pkt->flags & RESPONDER_FLAGS);
 }

 void
 Packet::pushSenderState(Packet::SenderState *sender_state)
 {
     assert(sender_state != NULL);
     sender_state->predecessor = senderState;
     senderState = sender_state;
 }

 Packet::SenderState *
 Packet::popSenderState()
 {
     assert(senderState != NULL);
     SenderState *sender_state = senderState;
     senderState = sender_state->predecessor;
     sender_state->predecessor = NULL;
     return sender_state;
 }

 uint64_t
 Packet::getUintX(ByteOrder endian) const
 {
     auto [val, success] =
         gem5::getUintX(getConstPtr<void>(), getSize(), endian);
     panic_if(!success, "%i isn't a supported word size.\n", getSize());
     return val;
 }

 void
 Packet::setUintX(uint64_t w, ByteOrder endian)
 {
     bool success = gem5::setUintX(w, getPtr<void>(), getSize(), endian);
     panic_if(!success, "%i isn't a supported word size.\n", getSize());
 }

 void
 Packet::print(std::ostream &o, const int verbosity,
               const std::string &prefix) const
 {
     ccprintf(o, "%s%s [%x:%x]%s%s%s%s%s%s", prefix, cmdString(),
              getAddr(), getAddr() + getSize() - 1,
              req->isSecure() ? " (s)" : "",
              req->isInstFetch() ? " IF" : "",
              req->isUncacheable() ? " UC" : "",
              isExpressSnoop() ? " ES" : "",
              req->isToPOC() ? " PoC" : "",
              req->isToPOU() ? " PoU" : "");
 }

 std::string
 Packet::print() const {
     std::ostringstream str;
     print(str);
     return str.str();
 }

 bool
 Packet::matchBlockAddr(const Addr addr, const bool is_secure,
                        const int blk_size) const
 {
     return (getBlockAddr(blk_size) == addr) && (isSecure() == is_secure);
 }

 bool
 Packet::matchBlockAddr(const PacketPtr pkt, const int blk_size) const
 {
     return matchBlockAddr(pkt->getBlockAddr(blk_size), pkt->isSecure(),
                           blk_size);
 }

 bool
 Packet::matchAddr(const Addr addr, const bool is_secure) const
 {
     return (getAddr() == addr) && (isSecure() == is_secure);
 }

 bool
 Packet::matchAddr(const PacketPtr pkt) const
 {
     return matchAddr(pkt->getAddr(), pkt->isSecure());
 }

 Packet::PrintReqState::PrintReqState(std::ostream &_os, int _verbosity)
     : curPrefixPtr(new std::string("")), os(_os), verbosity(_verbosity)
 {
     labelStack.push_back(LabelStackEntry("", curPrefixPtr));
 }

 Packet::PrintReqState::~PrintReqState()
 {
     labelStack.pop_back();
     assert(labelStack.empty());
     delete curPrefixPtr;
 }

 Packet::PrintReqState::
 LabelStackEntry::LabelStackEntry(const std::string &_label,
                                  std::string *_prefix)
     : label(_label), prefix(_prefix), labelPrinted(false)
 {
 }

 void
 Packet::PrintReqState::pushLabel(const std::string &lbl,
                                  const std::string &prefix)
 {
     labelStack.push_back(LabelStackEntry(lbl, curPrefixPtr));
     curPrefixPtr = new std::string(*curPrefixPtr);
     *curPrefixPtr += prefix;
 }

 void
 Packet::PrintReqState::popLabel()
 {
     delete curPrefixPtr;
     curPrefixPtr = labelStack.back().prefix;
     labelStack.pop_back();
     assert(!labelStack.empty());
 }

 void
 Packet::PrintReqState::printLabels()
 {
     if (!labelStack.back().labelPrinted) {
         LabelStack::iterator i = labelStack.begin();
         LabelStack::iterator end = labelStack.end();
         while (i != end) {
             if (!i->labelPrinted) {
                 ccprintf(os, "%s%s\n", *(i->prefix), i->label);
                 i->labelPrinted = true;
             }
             i++;
         }
     }
 }


 void
 Packet::PrintReqState::printObj(Printable *obj)
 {
     printLabels();
     obj->print(os, verbosity, curPrefix());
 }

 void
 Packet::makeHtmTransactionalReqResponse(
     const HtmCacheFailure htm_return_code)
 {
     assert(needsResponse());
     assert(isRequest());

     cmd = cmd.responseCommand();

     setHtmTransactionFailedInCache(htm_return_code);

     // responses are never express, even if the snoop that
     // triggered them was
     flags.clear(EXPRESS_SNOOP);
 }

 void
 Packet::setHtmTransactionFailedInCache(
     const HtmCacheFailure htm_return_code)
 {
     if (htm_return_code != HtmCacheFailure::NO_FAIL)
         flags.set(FAILS_TRANSACTION);

     htmReturnReason = htm_return_code;
 }

 bool
 Packet::htmTransactionFailedInCache() const
 {
     return flags.isSet(FAILS_TRANSACTION);
 }

 HtmCacheFailure
 Packet::getHtmTransactionFailedInCacheRC() const
 {
     assert(htmTransactionFailedInCache());
     return htmReturnReason;
 }

 void
 Packet::setHtmTransactional(uint64_t htm_uid)
 {
     flags.set(FROM_TRANSACTION);
     htmTransactionUid = htm_uid;
 }

 bool
 Packet::isHtmTransactional() const
 {
     return flags.isSet(FROM_TRANSACTION);
 }

 uint64_t
 Packet::getHtmTransactionUid() const
 {
     assert(flags.isSet(FROM_TRANSACTION));
     return htmTransactionUid;
 }

 } // namespace gem5
	/*
	* Copyright (c) 2011-2019, 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.
	*
	* Copyright (c) 2006 The Regents of The University of Michigan
	* Copyright (c) 2010,2015 Advanced Micro Devices, Inc.
	* 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.
	*/

	/**
	* @file
	* Definition of the Packet Class, a packet is a transaction occuring
	* between a single level of the memory heirarchy (ie L1->L2).
	*/

	#include "mem/packet.hh"

	#include <algorithm>
	#include <cstring>
	#include <iostream>
	#include <sstream>
	#include <string>

	#include "base/cprintf.hh"
	#include "base/logging.hh"
	#include "base/trace.hh"
	#include "mem/packet_access.hh"
	#include "sim/bufval.hh"

	namespace gem5
	{

	const MemCmd::CommandInfo
	MemCmd::commandInfo[] =
	{
	/* InvalidCmd */
	{ {}, InvalidCmd, "InvalidCmd" },
	/* ReadReq - Read issued by a non-caching agent such as a CPU or
	* device, with no restrictions on alignment. */
	{ {IsRead, IsRequest, NeedsResponse}, ReadResp, "ReadReq" },
	/* ReadResp */
	{ {IsRead, IsResponse, HasData}, InvalidCmd, "ReadResp" },
	/* ReadRespWithInvalidate */
	{ {IsRead, IsResponse, HasData, IsInvalidate},
	InvalidCmd, "ReadRespWithInvalidate" },
	/* WriteReq */
	{ {IsWrite, NeedsWritable, IsRequest, NeedsResponse, HasData},
	WriteResp, "WriteReq" },
	/* WriteResp */
	{ {IsWrite, IsResponse}, InvalidCmd, "WriteResp" },
	/* WriteCompleteResp - The WriteCompleteResp command is needed
	* because in the GPU memory model we use a WriteResp to indicate
	* that a write has reached the cache controller so we can free
	* resources at the coalescer. Later, when the write succesfully
	* completes we send a WriteCompleteResp to the CU so its wait
	* counters can be updated. Wait counters in the CU is how memory
	* dependences are handled in the GPU ISA. */
	{ {IsWrite, IsResponse}, InvalidCmd, "WriteCompleteResp" },
	/* WritebackDirty */
	{ {IsWrite, IsRequest, IsEviction, HasData, FromCache},
	InvalidCmd, "WritebackDirty" },
	/* WritebackClean - This allows the upstream cache to writeback a
	* line to the downstream cache without it being considered
	* dirty. */
	{ {IsWrite, IsRequest, IsEviction, HasData, FromCache},
	InvalidCmd, "WritebackClean" },
	/* WriteClean - This allows a cache to write a dirty block to a memory
	below without evicting its copy. */
	{ {IsWrite, IsRequest, HasData, FromCache}, InvalidCmd, "WriteClean" },
	/* CleanEvict */
	{ {IsRequest, IsEviction, FromCache}, InvalidCmd, "CleanEvict" },
	/* SoftPFReq */
	{ {IsRead, IsRequest, IsSWPrefetch, NeedsResponse},
	SoftPFResp, "SoftPFReq" },
	/* SoftPFExReq */
	{ {IsRead, NeedsWritable, IsInvalidate, IsRequest,
	IsSWPrefetch, NeedsResponse}, SoftPFResp, "SoftPFExReq" },
	/* HardPFReq */
	{ {IsRead, IsRequest, IsHWPrefetch, NeedsResponse, FromCache},
	HardPFResp, "HardPFReq" },
	/* SoftPFResp */
	{ {IsRead, IsResponse, IsSWPrefetch, HasData}, InvalidCmd, "SoftPFResp" },
	/* HardPFResp */
	{ {IsRead, IsResponse, IsHWPrefetch, HasData}, InvalidCmd, "HardPFResp" },
	/* WriteLineReq */
	{ {IsWrite, NeedsWritable, IsRequest, NeedsResponse, HasData},
	WriteResp, "WriteLineReq" },
	/* UpgradeReq */
	{ {IsInvalidate, NeedsWritable, IsUpgrade, IsRequest, NeedsResponse,
	FromCache}, UpgradeResp, "UpgradeReq" },
	/* SCUpgradeReq: response could be UpgradeResp or UpgradeFailResp */
	{ {IsInvalidate, NeedsWritable, IsUpgrade, IsLlsc,
	IsRequest, NeedsResponse, FromCache},
	UpgradeResp, "SCUpgradeReq" },
	/* UpgradeResp */
	{ {IsUpgrade, IsResponse}, InvalidCmd, "UpgradeResp" },
	/* SCUpgradeFailReq: generates UpgradeFailResp but still gets the data */
	{ {IsRead, NeedsWritable, IsInvalidate,
	IsLlsc, IsRequest, NeedsResponse, FromCache},
	UpgradeFailResp, "SCUpgradeFailReq" },
	/* UpgradeFailResp - Behaves like a ReadExReq, but notifies an SC
	* that it has failed, acquires line as Dirty*/
	{ {IsRead, IsResponse, HasData}, InvalidCmd, "UpgradeFailResp" },
	/* ReadExReq - Read issues by a cache, always cache-line aligned,
	* and the response is guaranteed to be writeable (exclusive or
	* even modified} */
	{ {IsRead, NeedsWritable, IsInvalidate, IsRequest, NeedsResponse,
	FromCache}, ReadExResp, "ReadExReq" },
	/* ReadExResp - Response matching a read exclusive, as we check
	* the need for exclusive also on responses */
	{ {IsRead, IsResponse, HasData}, InvalidCmd, "ReadExResp" },
	/* ReadCleanReq - Read issued by a cache, always cache-line
	* aligned, and the response is guaranteed to not contain dirty data
	* (exclusive or shared}.*/
	{ {IsRead, IsRequest, NeedsResponse, FromCache},
	ReadResp, "ReadCleanReq" },
	/* ReadSharedReq - Read issued by a cache, always cache-line
	* aligned, response is shared, possibly exclusive, owned or even
	* modified. */
	{ {IsRead, IsRequest, NeedsResponse, FromCache},
	ReadResp, "ReadSharedReq" },
	/* LoadLockedReq: note that we use plain ReadResp as response, so that
	* we can also use ReadRespWithInvalidate when needed */
	{ {IsRead, IsLlsc, IsRequest, NeedsResponse},
	ReadResp, "LoadLockedReq" },
	/* StoreCondReq */
	{ {IsWrite, NeedsWritable, IsLlsc,
	IsRequest, NeedsResponse, HasData},
	StoreCondResp, "StoreCondReq" },
	/* StoreCondFailReq: generates failing StoreCondResp */
	{ {IsWrite, NeedsWritable, IsLlsc, IsRequest, NeedsResponse, HasData},
	StoreCondResp, "StoreCondFailReq" },
	/* StoreCondResp */
	{ {IsWrite, IsLlsc, IsResponse},
	InvalidCmd, "StoreCondResp" },
	/* LockedRMWReadReq */
	{ {IsRead, IsLockedRMW, NeedsWritable, IsRequest, NeedsResponse},
	LockedRMWReadResp, "LockedRMWReadReq" },
	/* LockedRMWReadResp */
	{ {IsRead, IsLockedRMW, NeedsWritable, IsResponse, HasData},
	InvalidCmd, "LockedRMWReadResp" },
	/* LockedRMWWriteReq */
	{ {IsWrite, IsLockedRMW, NeedsWritable, IsRequest, NeedsResponse,
	HasData}, LockedRMWWriteResp, "LockedRMWWriteReq" },
	/* LockedRMWWriteResp */
	{ {IsWrite, IsLockedRMW, NeedsWritable, IsResponse},
	InvalidCmd, "LockedRMWWriteResp" },
	/* SwapReq -- for Swap ldstub type operations */
	{ {IsRead, IsWrite, NeedsWritable, IsRequest, HasData, NeedsResponse},
	SwapResp, "SwapReq" },
	/* SwapResp -- for Swap ldstub type operations */
	{ {IsRead, IsWrite, IsResponse, HasData}, InvalidCmd, "SwapResp" },
	{ {}, InvalidCmd, "Deprecated_MessageReq" },
	{ {}, InvalidCmd, "Deprecated_MessageResp" },
	/* MemFenceReq -- for synchronization requests */
	{{IsRequest, NeedsResponse}, MemFenceResp, "MemFenceReq"},
	/* MemSyncReq */
	{{IsRequest, NeedsResponse}, MemSyncResp, "MemSyncReq"},
	/* MemSyncResp */
	{{IsResponse}, InvalidCmd, "MemSyncResp"},
	/* MemFenceResp -- for synchronization responses */
	{{IsResponse}, InvalidCmd, "MemFenceResp"},
	/* Cache Clean Request -- Update with the latest data all existing
	copies of the block down to the point indicated by the
	request */
	{ {IsRequest, IsClean, NeedsResponse, FromCache},
	CleanSharedResp, "CleanSharedReq" },
	/* Cache Clean Response - Indicates that all caches up to the
	specified point of reference have a up-to-date copy of the
	cache block or no copy at all */
	{ {IsResponse, IsClean}, InvalidCmd, "CleanSharedResp" },
	/* Cache Clean and Invalidate Request -- Invalidate all existing
	copies down to the point indicated by the request */
	{ {IsRequest, IsInvalidate, IsClean, NeedsResponse, FromCache},
	CleanInvalidResp, "CleanInvalidReq" },
	/* Cache Clean and Invalidate Respose -- Indicates that no cache
	above the specified point holds the block and that the block
	was written to a memory below the specified point. */
	{ {IsResponse, IsInvalidate, IsClean},
	InvalidCmd, "CleanInvalidResp" },
	/* InvalidDestError -- packet dest field invalid */
	{ {IsResponse, IsError}, InvalidCmd, "InvalidDestError" },
	/* BadAddressError -- memory address invalid */
	{ {IsResponse, IsError}, InvalidCmd, "BadAddressError" },
	/* ReadError -- packet dest unable to fulfill read command */
	{ {IsRead, IsResponse, IsError}, InvalidCmd, "ReadError" },
	/* WriteError -- packet dest unable to fulfill write command */
	{ {IsWrite, IsResponse, IsError}, InvalidCmd, "WriteError" },
	/* FunctionalReadError */
	{ {IsRead, IsResponse, IsError}, InvalidCmd, "FunctionalReadError" },
	/* FunctionalWriteError */
	{ {IsWrite, IsResponse, IsError}, InvalidCmd, "FunctionalWriteError" },
	/* PrintReq */
	{ {IsRequest, IsPrint}, InvalidCmd, "PrintReq" },
	/* Flush Request */
	{ {IsRequest, IsFlush, NeedsWritable}, InvalidCmd, "FlushReq" },
	/* Invalidation Request */
	{ {IsInvalidate, IsRequest, NeedsWritable, NeedsResponse, FromCache},
	InvalidateResp, "InvalidateReq" },
	/* Invalidation Response */
	{ {IsInvalidate, IsResponse},
	InvalidCmd, "InvalidateResp" },
	// hardware transactional memory
	{ {IsRead, IsRequest, NeedsResponse}, HTMReqResp, "HTMReq" },
	{ {IsRead, IsResponse}, InvalidCmd, "HTMReqResp" },
	{ {IsRead, IsRequest}, InvalidCmd, "HTMAbort" },
	{ {IsRequest}, InvalidCmd, "TlbiExtSync" },
	};

	AddrRange
	Packet::getAddrRange() const
	{
	return RangeSize(getAddr(), getSize());
	}

	bool
	Packet::trySatisfyFunctional(Printable *obj, Addr addr, bool is_secure, int size,
	uint8_t *_data)
	{
	const Addr func_start = getAddr();
	const Addr func_end = getAddr() + getSize() - 1;
	const Addr val_start = addr;
	const Addr val_end = val_start + size - 1;

	if (is_secure != _isSecure \|\| func_start > val_end \|\|
	val_start > func_end) {
	// no intersection
	return false;
	}

	// check print first since it doesn't require data
	if (isPrint()) {
	assert(!_data);
	safe_cast<PrintReqState*>(senderState)->printObj(obj);
	return false;
	}

	// we allow the caller to pass NULL to signify the other packet
	// has no data
	if (!_data) {
	return false;
	}

	const Addr val_offset = func_start > val_start ?
	func_start - val_start : 0;
	const Addr func_offset = func_start < val_start ?
	val_start - func_start : 0;
	const Addr overlap_size = std::min(val_end, func_end)+1 -
	std::max(val_start, func_start);

	if (isRead()) {
	std::memcpy(getPtr<uint8_t>() + func_offset,
	_data + val_offset,
	overlap_size);

	// initialise the tracking of valid bytes if we have not
	// used it already
	if (bytesValid.empty())
	bytesValid.resize(getSize(), false);

	// track if we are done filling the functional access
	bool all_bytes_valid = true;

	int i = 0;

	// check up to func_offset
	for (; all_bytes_valid && i < func_offset; ++i)
	all_bytes_valid &= bytesValid[i];

	// update the valid bytes
	for (i = func_offset; i < func_offset + overlap_size; ++i)
	bytesValid[i] = true;

	// check the bit after the update we just made
	for (; all_bytes_valid && i < getSize(); ++i)
	all_bytes_valid &= bytesValid[i];

	return all_bytes_valid;
	} else if (isWrite()) {
	std::memcpy(_data + val_offset,
	getConstPtr<uint8_t>() + func_offset,
	overlap_size);
	} else {
	panic("Don't know how to handle command %s\n", cmdString());
	}

	// keep going with request by default
	return false;
	}

	void
	Packet::copyResponderFlags(const PacketPtr pkt)
	{
	assert(isRequest());
	// If we have already found a responder, no other cache should
	// commit to responding
	assert(!pkt->cacheResponding() \|\| !cacheResponding());
	flags.set(pkt->flags & RESPONDER_FLAGS);
	}

	void
	Packet::pushSenderState(Packet::SenderState *sender_state)
	{
	assert(sender_state != NULL);
	sender_state->predecessor = senderState;
	senderState = sender_state;
	}

	Packet::SenderState *
	Packet::popSenderState()
	{
	assert(senderState != NULL);
	SenderState *sender_state = senderState;
	senderState = sender_state->predecessor;
	sender_state->predecessor = NULL;
	return sender_state;
	}

	uint64_t
	Packet::getUintX(ByteOrder endian) const
	{
	auto [val, success] =
	gem5::getUintX(getConstPtr<void>(), getSize(), endian);
	panic_if(!success, "%i isn't a supported word size.\n", getSize());
	return val;
	}

	void
	Packet::setUintX(uint64_t w, ByteOrder endian)
	{
	bool success = gem5::setUintX(w, getPtr<void>(), getSize(), endian);
	panic_if(!success, "%i isn't a supported word size.\n", getSize());
	}

	void
	Packet::print(std::ostream &o, const int verbosity,
	const std::string &prefix) const
	{
	ccprintf(o, "%s%s [%x:%x]%s%s%s%s%s%s", prefix, cmdString(),
	getAddr(), getAddr() + getSize() - 1,
	req->isSecure() ? " (s)" : "",
	req->isInstFetch() ? " IF" : "",
	req->isUncacheable() ? " UC" : "",
	isExpressSnoop() ? " ES" : "",
	req->isToPOC() ? " PoC" : "",
	req->isToPOU() ? " PoU" : "");
	}

	std::string
	Packet::print() const {
	std::ostringstream str;
	print(str);
	return str.str();
	}

	bool
	Packet::matchBlockAddr(const Addr addr, const bool is_secure,
	const int blk_size) const
	{
	return (getBlockAddr(blk_size) == addr) && (isSecure() == is_secure);
	}

	bool
	Packet::matchBlockAddr(const PacketPtr pkt, const int blk_size) const
	{
	return matchBlockAddr(pkt->getBlockAddr(blk_size), pkt->isSecure(),
	blk_size);
	}

	bool
	Packet::matchAddr(const Addr addr, const bool is_secure) const
	{
	return (getAddr() == addr) && (isSecure() == is_secure);
	}

	bool
	Packet::matchAddr(const PacketPtr pkt) const
	{
	return matchAddr(pkt->getAddr(), pkt->isSecure());
	}

	Packet::PrintReqState::PrintReqState(std::ostream &_os, int _verbosity)
	: curPrefixPtr(new std::string("")), os(_os), verbosity(_verbosity)
	{
	labelStack.push_back(LabelStackEntry("", curPrefixPtr));
	}

	Packet::PrintReqState::~PrintReqState()
	{
	labelStack.pop_back();
	assert(labelStack.empty());
	delete curPrefixPtr;
	}

	Packet::PrintReqState::
	LabelStackEntry::LabelStackEntry(const std::string &_label,
	std::string *_prefix)
	: label(_label), prefix(_prefix), labelPrinted(false)
	{
	}

	void
	Packet::PrintReqState::pushLabel(const std::string &lbl,
	const std::string &prefix)
	{
	labelStack.push_back(LabelStackEntry(lbl, curPrefixPtr));
	curPrefixPtr = new std::string(*curPrefixPtr);
	*curPrefixPtr += prefix;
	}

	void
	Packet::PrintReqState::popLabel()
	{
	delete curPrefixPtr;
	curPrefixPtr = labelStack.back().prefix;
	labelStack.pop_back();
	assert(!labelStack.empty());
	}

	void
	Packet::PrintReqState::printLabels()
	{
	if (!labelStack.back().labelPrinted) {
	LabelStack::iterator i = labelStack.begin();
	LabelStack::iterator end = labelStack.end();
	while (i != end) {
	if (!i->labelPrinted) {
	ccprintf(os, "%s%s\n", *(i->prefix), i->label);
	i->labelPrinted = true;
	}
	i++;
	}
	}
	}


	void
	Packet::PrintReqState::printObj(Printable *obj)
	{
	printLabels();
	obj->print(os, verbosity, curPrefix());
	}

	void
	Packet::makeHtmTransactionalReqResponse(
	const HtmCacheFailure htm_return_code)
	{
	assert(needsResponse());
	assert(isRequest());

	cmd = cmd.responseCommand();

	setHtmTransactionFailedInCache(htm_return_code);

	// responses are never express, even if the snoop that
	// triggered them was
	flags.clear(EXPRESS_SNOOP);
	}

	void
	Packet::setHtmTransactionFailedInCache(
	const HtmCacheFailure htm_return_code)
	{
	if (htm_return_code != HtmCacheFailure::NO_FAIL)
	flags.set(FAILS_TRANSACTION);

	htmReturnReason = htm_return_code;
	}

	bool
	Packet::htmTransactionFailedInCache() const
	{
	return flags.isSet(FAILS_TRANSACTION);
	}

	HtmCacheFailure
	Packet::getHtmTransactionFailedInCacheRC() const
	{
	assert(htmTransactionFailedInCache());
	return htmReturnReason;
	}

	void
	Packet::setHtmTransactional(uint64_t htm_uid)
	{
	flags.set(FROM_TRANSACTION);
	htmTransactionUid = htm_uid;
	}

	bool
	Packet::isHtmTransactional() const
	{
	return flags.isSet(FROM_TRANSACTION);
	}

	uint64_t
	Packet::getHtmTransactionUid() const
	{
	assert(flags.isSet(FROM_TRANSACTION));
	return htmTransactionUid;
	}

	} // namespace gem5