src/mem/packet.hh

   1 /*
   2  * Copyright (c) 2006 The Regents of The University of Michigan
   3  * Copyright (c) 2010 Advanced Micro Devices, Inc.
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are
   8  * met: redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer;
  10  * redistributions in binary form must reproduce the above copyright
  11  * notice, this list of conditions and the following disclaimer in the
  12  * documentation and/or other materials provided with the distribution;
  13  * neither the name of the copyright holders nor the names of its
  14  * contributors may be used to endorse or promote products derived from
  15  * this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  20  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  21  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  23  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *
  29  * Authors: Ron Dreslinski
  30  *          Steve Reinhardt
  31  *          Ali Saidi
  32  */
  33
  34 /**
  35  * @file
  36  * Declaration of the Packet class.
  37  */
  38
  39 #ifndef __MEM_PACKET_HH__
  40 #define __MEM_PACKET_HH__
  41
  42 #include <bitset>
  43 #include <cassert>
  44 #include <list>
  45
  46 #include "base/cast.hh"
  47 #include "base/compiler.hh"
  48 #include "base/fast_alloc.hh"
  49 #include "base/flags.hh"
  50 #include "base/misc.hh"
  51 #include "base/printable.hh"
  52 #include "base/types.hh"
  53 #include "mem/request.hh"
  54 #include "sim/core.hh"
  55
  56 struct Packet;
  57 typedef Packet *PacketPtr;
  58 typedef uint8_t* PacketDataPtr;
  59 typedef std::list<PacketPtr> PacketList;
  60
  61 class MemCmd
  62 {
  63     friend class Packet;
  64
  65   public:
  66     /**
  67      * List of all commands associated with a packet.
  68      */
  69     enum Command
  70     {
  71         InvalidCmd,
  72         ReadReq,
  73         ReadResp,
  74         ReadRespWithInvalidate,
  75         WriteReq,
  76         WriteResp,
  77         Writeback,
  78         SoftPFReq,
  79         HardPFReq,
  80         SoftPFResp,
  81         HardPFResp,
  82         WriteInvalidateReq,
  83         WriteInvalidateResp,
  84         UpgradeReq,
  85         SCUpgradeReq,           // Special "weak" upgrade for StoreCond
  86         UpgradeResp,
  87         SCUpgradeFailReq,       // Failed SCUpgradeReq in MSHR (never sent)
  88         UpgradeFailResp,        // Valid for SCUpgradeReq only
  89         ReadExReq,
  90         ReadExResp,
  91         LoadLockedReq,
  92         StoreCondReq,
  93         StoreCondFailReq,       // Failed StoreCondReq in MSHR (never sent)
  94         StoreCondResp,
  95         SwapReq,
  96         SwapResp,
  97         MessageReq,
  98         MessageResp,
  99         // Error responses
 100         // @TODO these should be classified as responses rather than
 101         // requests; coding them as requests initially for backwards
 102         // compatibility
 103         NetworkNackError,  // nacked at network layer (not by protocol)
 104         InvalidDestError,  // packet dest field invalid
 105         BadAddressError,   // memory address invalid
 106         FunctionalReadError, // unable to fulfill functional read
 107         FunctionalWriteError, // unable to fulfill functional write
 108         // Fake simulator-only commands
 109         PrintReq,       // Print state matching address
 110         FlushReq,      //request for a cache flush
 111         NUM_MEM_CMDS
 112     };
 113
 114   private:
 115     /**
 116      * List of command attributes.
 117      */
 118     enum Attribute
 119     {
 120         IsRead,         //!< Data flows from responder to requester
 121         IsWrite,        //!< Data flows from requester to responder
 122         IsUpgrade,
 123         IsPrefetch,     //!< Not a demand access
 124         IsInvalidate,
 125         NeedsExclusive, //!< Requires exclusive copy to complete in-cache
 126         IsRequest,      //!< Issued by requester
 127         IsResponse,     //!< Issue by responder
 128         NeedsResponse,  //!< Requester needs response from target
 129         IsSWPrefetch,
 130         IsHWPrefetch,
 131         IsLlsc,         //!< Alpha/MIPS LL or SC access
 132         HasData,        //!< There is an associated payload
 133         IsError,        //!< Error response
 134         IsPrint,        //!< Print state matching address (for debugging)
 135         IsFlush,        //!< Flush the address from caches
 136         NUM_COMMAND_ATTRIBUTES
 137     };
 138
 139     /**
 140      * Structure that defines attributes and other data associated
 141      * with a Command.
 142      */
 143     struct CommandInfo
 144     {
 145         /// Set of attribute flags.
 146         const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
 147         /// Corresponding response for requests; InvalidCmd if no
 148         /// response is applicable.
 149         const Command response;
 150         /// String representation (for printing)
 151         const std::string str;
 152     };
 153
 154     /// Array to map Command enum to associated info.
 155     static const CommandInfo commandInfo[];
 156
 157   private:
 158
 159     Command cmd;
 160
 161     bool
 162     testCmdAttrib(MemCmd::Attribute attrib) const
 163     {
 164         return commandInfo[cmd].attributes[attrib] != 0;
 165     }
 166
 167   public:
 168
 169     bool isRead() const         { return testCmdAttrib(IsRead); }
 170     bool isWrite() const        { return testCmdAttrib(IsWrite); }
 171     bool isUpgrade() const      { return testCmdAttrib(IsUpgrade); }
 172     bool isRequest() const      { return testCmdAttrib(IsRequest); }
 173     bool isResponse() const     { return testCmdAttrib(IsResponse); }
 174     bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); }
 175     bool needsResponse() const  { return testCmdAttrib(NeedsResponse); }
 176     bool isInvalidate() const   { return testCmdAttrib(IsInvalidate); }
 177     bool hasData() const        { return testCmdAttrib(HasData); }
 178     bool isReadWrite() const    { return isRead() && isWrite(); }
 179     bool isLLSC() const         { return testCmdAttrib(IsLlsc); }
 180     bool isError() const        { return testCmdAttrib(IsError); }
 181     bool isPrint() const        { return testCmdAttrib(IsPrint); }
 182     bool isFlush() const        { return testCmdAttrib(IsFlush); }
 183
 184     const Command
 185     responseCommand() const
 186     {
 187         return commandInfo[cmd].response;
 188     }
 189
 190     /// Return the string to a cmd given by idx.
 191     const std::string &toString() const { return commandInfo[cmd].str; }
 192     int toInt() const { return (int)cmd; }
 193
 194     MemCmd(Command _cmd) : cmd(_cmd) { }
 195     MemCmd(int _cmd) : cmd((Command)_cmd) { }
 196     MemCmd() : cmd(InvalidCmd) { }
 197
 198     bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
 199     bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
 200 };
 201
 202 /**
 203  * A Packet is used to encapsulate a transfer between two objects in
 204  * the memory system (e.g., the L1 and L2 cache).  (In contrast, a
 205  * single Request travels all the way from the requester to the
 206  * ultimate destination and back, possibly being conveyed by several
 207  * different Packets along the way.)
 208  */
 209 class Packet : public FastAlloc, public Printable
 210 {
 211   public:
 212     typedef uint32_t FlagsType;
 213     typedef ::Flags<FlagsType> Flags;
 214     typedef short NodeID;
 215
 216   private:
 217     static const FlagsType PUBLIC_FLAGS           = 0x00000000;
 218     static const FlagsType PRIVATE_FLAGS          = 0x00007F0F;
 219     static const FlagsType COPY_FLAGS             = 0x0000000F;
 220
 221     static const FlagsType SHARED                 = 0x00000001;
 222     // Special control flags
 223     /// Special timing-mode atomic snoop for multi-level coherence.
 224     static const FlagsType EXPRESS_SNOOP          = 0x00000002;
 225     /// Does supplier have exclusive copy?
 226     /// Useful for multi-level coherence.
 227     static const FlagsType SUPPLY_EXCLUSIVE       = 0x00000004;
 228     // Snoop response flags
 229     static const FlagsType MEM_INHIBIT            = 0x00000008;
 230     /// Are the 'addr' and 'size' fields valid?
 231     static const FlagsType VALID_ADDR             = 0x00000100;
 232     static const FlagsType VALID_SIZE             = 0x00000200;
 233     /// Is the 'src' field valid?
 234     static const FlagsType VALID_SRC              = 0x00000400;
 235     static const FlagsType VALID_DST              = 0x00000800;
 236     /// Is the data pointer set to a value that shouldn't be freed
 237     /// when the packet is destroyed?
 238     static const FlagsType STATIC_DATA            = 0x00001000;
 239     /// The data pointer points to a value that should be freed when
 240     /// the packet is destroyed.
 241     static const FlagsType DYNAMIC_DATA           = 0x00002000;
 242     /// the data pointer points to an array (thus delete []) needs to
 243     /// be called on it rather than simply delete.
 244     static const FlagsType ARRAY_DATA             = 0x00004000;
 245     /// suppress the error if this packet encounters a functional
 246     /// access failure.
 247     static const FlagsType SUPPRESS_FUNC_ERROR    = 0x00008000;
 248
 249     Flags flags;
 250
 251   public:
 252     typedef MemCmd::Command Command;
 253
 254     /// The command field of the packet.
 255     MemCmd cmd;
 256
 257     /// A pointer to the original request.
 258     RequestPtr req;
 259
 260   private:
 261    /**
 262     * A pointer to the data being transfered.  It can be differnt
 263     * sizes at each level of the heirarchy so it belongs in the
 264     * packet, not request. This may or may not be populated when a
 265     * responder recieves the packet. If not populated it memory should
 266     * be allocated.
 267     */
 268     PacketDataPtr data;
 269
 270     /// The address of the request.  This address could be virtual or
 271     /// physical, depending on the system configuration.
 272     Addr addr;
 273
 274     /// The size of the request or transfer.
 275     unsigned size;
 276
 277     /**
 278      * Device address (e.g., bus ID) of the source of the
 279      * transaction. The source is not responsible for setting this
 280      * field; it is set implicitly by the interconnect when the packet
 281      * is first sent.
 282      */
 283     NodeID src;
 284
 285     /**
 286      * Device address (e.g., bus ID) of the destination of the
 287      * transaction. The special value Broadcast indicates that the
 288      * packet should be routed based on its address. This field is
 289      * initialized in the constructor and is thus always valid (unlike
 290      * addr, size, and src).
 291      */
 292     NodeID dest;
 293
 294     /**
 295      * The original value of the command field.  Only valid when the
 296      * current command field is an error condition; in that case, the
 297      * previous contents of the command field are copied here.  This
 298      * field is *not* set on non-error responses.
 299      */
 300     MemCmd origCmd;
 301
 302     /**
 303      * These values specify the range of bytes found that satisfy a
 304      * functional read.
 305      */
 306     uint16_t bytesValidStart;
 307     uint16_t bytesValidEnd;
 308
 309   public:
 310     /// Used to calculate latencies for each packet.
 311     Tick time;
 312
 313     /// The time at which the packet will be fully transmitted
 314     Tick finishTime;
 315
 316     /// The time at which the first chunk of the packet will be transmitted
 317     Tick firstWordTime;
 318
 319     /// The special destination address indicating that the packet
 320     /// should be routed based on its address.
 321     static const NodeID Broadcast = -1;
 322
 323     /**
 324      * A virtual base opaque structure used to hold state associated
 325      * with the packet but specific to the sending device (e.g., an
 326      * MSHR).  A pointer to this state is returned in the packet's
 327      * response so that the sender can quickly look up the state
 328      * needed to process it.  A specific subclass would be derived
 329      * from this to carry state specific to a particular sending
 330      * device.
 331      */
 332     struct SenderState
 333     {
 334         virtual ~SenderState() {}
 335     };
 336
 337     /**
 338      * Object used to maintain state of a PrintReq.  The senderState
 339      * field of a PrintReq should always be of this type.
 340      */
 341     class PrintReqState : public SenderState, public FastAlloc
 342     {
 343       private:
 344         /**
 345          * An entry in the label stack.
 346          */
 347         struct LabelStackEntry
 348         {
 349             const std::string label;
 350             std::string *prefix;
 351             bool labelPrinted;
 352             LabelStackEntry(const std::string &_label, std::string *_prefix);
 353         };
 354
 355         typedef std::list<LabelStackEntry> LabelStack;
 356         LabelStack labelStack;
 357
 358         std::string *curPrefixPtr;
 359
 360       public:
 361         std::ostream &os;
 362         const int verbosity;
 363
 364         PrintReqState(std::ostream &os, int verbosity = 0);
 365         ~PrintReqState();
 366
 367         /**
 368          * Returns the current line prefix.
 369          */
 370         const std::string &curPrefix() { return *curPrefixPtr; }
 371
 372         /**
 373          * Push a label onto the label stack, and prepend the given
 374          * prefix string onto the current prefix.  Labels will only be
 375          * printed if an object within the label's scope is printed.
 376          */
 377         void pushLabel(const std::string &lbl,
 378                        const std::string &prefix = "  ");
 379
 380         /**
 381          * Pop a label off the label stack.
 382          */
 383         void popLabel();
 384
 385         /**
 386          * Print all of the pending unprinted labels on the
 387          * stack. Called by printObj(), so normally not called by
 388          * users unless bypassing printObj().
 389          */
 390         void printLabels();
 391
 392         /**
 393          * Print a Printable object to os, because it matched the
 394          * address on a PrintReq.
 395          */
 396         void printObj(Printable *obj);
 397     };
 398
 399     /**
 400      * This packet's sender state.  Devices should use dynamic_cast<>
 401      * to cast to the state appropriate to the sender.  The intent of
 402      * this variable is to allow a device to attach extra information
 403      * to a request.  A response packet must return the sender state
 404      * that was attached to the original request (even if a new packet
 405      * is created).
 406      */
 407     SenderState *senderState;
 408
 409     /// Return the string name of the cmd field (for debugging and
 410     /// tracing).
 411     const std::string &cmdString() const { return cmd.toString(); }
 412
 413     /// Return the index of this command.
 414     inline int cmdToIndex() const { return cmd.toInt(); }
 415
 416     bool isRead() const         { return cmd.isRead(); }
 417     bool isWrite() const        { return cmd.isWrite(); }
 418     bool isUpgrade()  const     { return cmd.isUpgrade(); }
 419     bool isRequest() const      { return cmd.isRequest(); }
 420     bool isResponse() const     { return cmd.isResponse(); }
 421     bool needsExclusive() const { return cmd.needsExclusive(); }
 422     bool needsResponse() const  { return cmd.needsResponse(); }
 423     bool isInvalidate() const   { return cmd.isInvalidate(); }
 424     bool hasData() const        { return cmd.hasData(); }
 425     bool isReadWrite() const    { return cmd.isReadWrite(); }
 426     bool isLLSC() const         { return cmd.isLLSC(); }
 427     bool isError() const        { return cmd.isError(); }
 428     bool isPrint() const        { return cmd.isPrint(); }
 429     bool isFlush() const        { return cmd.isFlush(); }
 430
 431     // Snoop flags
 432     void assertMemInhibit()     { flags.set(MEM_INHIBIT); }
 433     bool memInhibitAsserted()   { return flags.isSet(MEM_INHIBIT); }
 434     void assertShared()         { flags.set(SHARED); }
 435     bool sharedAsserted()       { return flags.isSet(SHARED); }
 436
 437     // Special control flags
 438     void setExpressSnoop()      { flags.set(EXPRESS_SNOOP); }
 439     bool isExpressSnoop()       { return flags.isSet(EXPRESS_SNOOP); }
 440     void setSupplyExclusive()   { flags.set(SUPPLY_EXCLUSIVE); }
 441     void clearSupplyExclusive() { flags.clear(SUPPLY_EXCLUSIVE); }
 442     bool isSupplyExclusive()    { return flags.isSet(SUPPLY_EXCLUSIVE); }
 443     void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); }
 444     bool suppressFuncError()    { return flags.isSet(SUPPRESS_FUNC_ERROR); }
 445
 446     // Network error conditions... encapsulate them as methods since
 447     // their encoding keeps changing (from result field to command
 448     // field, etc.)
 449     void
 450     setNacked()
 451     {
 452         assert(isResponse());
 453         cmd = MemCmd::NetworkNackError;
 454     }
 455
 456     void
 457     setBadAddress()
 458     {
 459         assert(isResponse());
 460         cmd = MemCmd::BadAddressError;
 461     }
 462
 463     bool wasNacked() const     { return cmd == MemCmd::NetworkNackError; }
 464     bool hadBadAddress() const { return cmd == MemCmd::BadAddressError; }
 465     void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
 466
 467     bool isSrcValid() { return flags.isSet(VALID_SRC); }
 468     /// Accessor function to get the source index of the packet.
 469     NodeID getSrc() const    { assert(flags.isSet(VALID_SRC)); return src; }
 470     /// Accessor function to set the source index of the packet.
 471     void setSrc(NodeID _src) { src = _src; flags.set(VALID_SRC); }
 472     /// Reset source field, e.g. to retransmit packet on different bus.
 473     void clearSrc() { flags.clear(VALID_SRC); }
 474
 475     bool isDestValid() { return flags.isSet(VALID_DST); }
 476     /// Accessor function for the destination index of the packet.
 477     NodeID getDest() const     { assert(flags.isSet(VALID_DST)); return dest; }
 478     /// Accessor function to set the destination index of the packet.
 479     void setDest(NodeID _dest) { dest = _dest; flags.set(VALID_DST); }
 480
 481     Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
 482     unsigned getSize() const  { assert(flags.isSet(VALID_SIZE)); return size; }
 483     Addr getOffset(int blkSize) const { return getAddr() & (Addr)(blkSize - 1); }
 484
 485     /**
 486      * It has been determined that the SC packet should successfully update
 487      * memory.  Therefore, convert this SC packet to a normal write.
 488      */
 489     void
 490     convertScToWrite()
 491     {
 492         assert(isLLSC());
 493         assert(isWrite());
 494         cmd = MemCmd::WriteReq;
 495     }
 496
 497     /**
 498      * When ruby is in use, Ruby will monitor the cache line and thus M5
 499      * phys memory should treat LL ops as normal reads.
 500      */
 501     void
 502     convertLlToRead()
 503     {
 504         assert(isLLSC());
 505         assert(isRead());
 506         cmd = MemCmd::ReadReq;
 507     }
 508
 509     /**
 510      * Constructor.  Note that a Request object must be constructed
 511      * first, but the Requests's physical address and size fields need
 512      * not be valid. The command and destination addresses must be
 513      * supplied.
 514      */
 515     Packet(Request *_req, MemCmd _cmd, NodeID _dest)
 516         :  flags(VALID_DST), cmd(_cmd), req(_req), data(NULL),
 517            dest(_dest), bytesValidStart(0), bytesValidEnd(0),
 518            time(curTick()), senderState(NULL)
 519     {
 520         if (req->hasPaddr()) {
 521             addr = req->getPaddr();
 522             flags.set(VALID_ADDR);
 523         }
 524         if (req->hasSize()) {
 525             size = req->getSize();
 526             flags.set(VALID_SIZE);
 527         }
 528     }
 529
 530     /**
 531      * Alternate constructor if you are trying to create a packet with
 532      * a request that is for a whole block, not the address from the
 533      * req.  this allows for overriding the size/addr of the req.
 534      */
 535     Packet(Request *_req, MemCmd _cmd, NodeID _dest, int _blkSize)
 536         :  flags(VALID_DST), cmd(_cmd), req(_req), data(NULL),
 537            dest(_dest), bytesValidStart(0), bytesValidEnd(0),
 538            time(curTick()), senderState(NULL)
 539     {
 540         if (req->hasPaddr()) {
 541             addr = req->getPaddr() & ~(_blkSize - 1);
 542             flags.set(VALID_ADDR);
 543         }
 544         size = _blkSize;
 545         flags.set(VALID_SIZE);
 546     }
 547
 548     /**
 549      * Alternate constructor for copying a packet.  Copy all fields
 550      * *except* if the original packet's data was dynamic, don't copy
 551      * that, as we can't guarantee that the new packet's lifetime is
 552      * less than that of the original packet.  In this case the new
 553      * packet should allocate its own data.
 554      */
 555     Packet(Packet *pkt, bool clearFlags = false)
 556         :  cmd(pkt->cmd), req(pkt->req),
 557            data(pkt->flags.isSet(STATIC_DATA) ? pkt->data : NULL),
 558            addr(pkt->addr), size(pkt->size), src(pkt->src), dest(pkt->dest),
 559            bytesValidStart(pkt->bytesValidStart), bytesValidEnd(pkt->bytesValidEnd),
 560            time(curTick()), senderState(pkt->senderState)
 561     {
 562         if (!clearFlags)
 563             flags.set(pkt->flags & COPY_FLAGS);
 564
 565         flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE|VALID_SRC|VALID_DST));
 566         flags.set(pkt->flags & STATIC_DATA);
 567
 568     }
 569
 570     /**
 571      * clean up packet variables
 572      */
 573     ~Packet()
 574     {
 575         // If this is a request packet for which there's no response,
 576         // delete the request object here, since the requester will
 577         // never get the chance.
 578         if (req && isRequest() && !needsResponse())
 579             delete req;
 580         deleteData();
 581     }
 582
 583     /**
 584      * Reinitialize packet address and size from the associated
 585      * Request object, and reset other fields that may have been
 586      * modified by a previous transaction.  Typically called when a
 587      * statically allocated Request/Packet pair is reused for multiple
 588      * transactions.
 589      */
 590     void
 591     reinitFromRequest()
 592     {
 593         assert(req->hasPaddr());
 594         flags = 0;
 595         addr = req->getPaddr();
 596         size = req->getSize();
 597         time = req->time();
 598
 599         flags.set(VALID_ADDR|VALID_SIZE);
 600         deleteData();
 601     }
 602
 603     /**
 604      * Take a request packet and modify it in place to be suitable for
 605      * returning as a response to that request.  The source and
 606      * destination fields are *not* modified, as is appropriate for
 607      * atomic accesses.
 608      */
 609     void
 610     makeResponse()
 611     {
 612         assert(needsResponse());
 613         assert(isRequest());
 614         origCmd = cmd;
 615         cmd = cmd.responseCommand();
 616
 617         // responses are never express, even if the snoop that
 618         // triggered them was
 619         flags.clear(EXPRESS_SNOOP);
 620
 621         dest = src;
 622         flags.set(VALID_DST, flags.isSet(VALID_SRC));
 623         flags.clear(VALID_SRC);
 624     }
 625
 626     void
 627     makeAtomicResponse()
 628     {
 629         makeResponse();
 630     }
 631
 632     void
 633     makeTimingResponse()
 634     {
 635         makeResponse();
 636     }
 637
 638     void
 639     setFunctionalResponseStatus(bool success)
 640     {
 641         if (!success) {
 642             if (isWrite()) {
 643                 cmd = MemCmd::FunctionalWriteError;
 644             } else {
 645                 cmd = MemCmd::FunctionalReadError;
 646             }
 647         }
 648     }
 649
 650     /**
 651      * Take a request packet that has been returned as NACKED and
 652      * modify it so that it can be sent out again. Only packets that
 653      * need a response can be NACKED, so verify that that is true.
 654      */
 655     void
 656     reinitNacked()
 657     {
 658         assert(wasNacked());
 659         cmd = origCmd;
 660         assert(needsResponse());
 661         setDest(Broadcast);
 662     }
 663
 664     void
 665     setSize(unsigned size)
 666     {
 667         assert(!flags.isSet(VALID_SIZE));
 668
 669         this->size = size;
 670         flags.set(VALID_SIZE);
 671     }
 672
 673
 674     /**
 675      * Set the data pointer to the following value that should not be
 676      * freed.
 677      */
 678     template <typename T>
 679     void
 680     dataStatic(T *p)
 681     {
 682         assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
 683         data = (PacketDataPtr)p;
 684         flags.set(STATIC_DATA);
 685     }
 686
 687     /**
 688      * Set the data pointer to a value that should have delete []
 689      * called on it.
 690      */
 691     template <typename T>
 692     void
 693     dataDynamicArray(T *p)
 694     {
 695         assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
 696         data = (PacketDataPtr)p;
 697         flags.set(DYNAMIC_DATA|ARRAY_DATA);
 698     }
 699
 700     /**
 701      * set the data pointer to a value that should have delete called
 702      * on it.
 703      */
 704     template <typename T>
 705     void
 706     dataDynamic(T *p)
 707     {
 708         assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
 709         data = (PacketDataPtr)p;
 710         flags.set(DYNAMIC_DATA);
 711     }
 712
 713     /**
 714      * get a pointer to the data ptr.
 715      */
 716     template <typename T>
 717     T*
 718     getPtr(bool null_ok = false)
 719     {
 720         assert(null_ok || flags.isSet(STATIC_DATA|DYNAMIC_DATA));
 721         return (T*)data;
 722     }
 723
 724     /**
 725      * return the value of what is pointed to in the packet.
 726      */
 727     template <typename T>
 728     T get();
 729
 730     /**
 731      * set the value in the data pointer to v.
 732      */
 733     template <typename T>
 734     void set(T v);
 735
 736     /**
 737      * Copy data into the packet from the provided pointer.
 738      */
 739     void
 740     setData(uint8_t *p)
 741     {
 742         if (p != getPtr<uint8_t>())
 743             std::memcpy(getPtr<uint8_t>(), p, getSize());
 744     }
 745
 746     /**
 747      * Copy data into the packet from the provided block pointer,
 748      * which is aligned to the given block size.
 749      */
 750     void
 751     setDataFromBlock(uint8_t *blk_data, int blkSize)
 752     {
 753         setData(blk_data + getOffset(blkSize));
 754     }
 755
 756     /**
 757      * Copy data from the packet to the provided block pointer, which
 758      * is aligned to the given block size.
 759      */
 760     void
 761     writeData(uint8_t *p)
 762     {
 763         std::memcpy(p, getPtr<uint8_t>(), getSize());
 764     }
 765
 766     /**
 767      * Copy data from the packet to the memory at the provided pointer.
 768      */
 769     void
 770     writeDataToBlock(uint8_t *blk_data, int blkSize)
 771     {
 772         writeData(blk_data + getOffset(blkSize));
 773     }
 774
 775     /**
 776      * delete the data pointed to in the data pointer. Ok to call to
 777      * matter how data was allocted.
 778      */
 779     void
 780     deleteData()
 781     {
 782         if (flags.isSet(ARRAY_DATA))
 783             delete [] data;
 784         else if (flags.isSet(DYNAMIC_DATA))
 785             delete data;
 786
 787         flags.clear(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA);
 788         data = NULL;
 789     }
 790
 791     /** If there isn't data in the packet, allocate some. */
 792     void
 793     allocate()
 794     {
 795         if (data) {
 796             assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
 797             return;
 798         }
 799
 800         assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
 801         flags.set(DYNAMIC_DATA|ARRAY_DATA);
 802         data = new uint8_t[getSize()];
 803     }
 804
 805     /**
 806      * Check a functional request against a memory value represented
 807      * by a base/size pair and an associated data array.  If the
 808      * functional request is a read, it may be satisfied by the memory
 809      * value.  If the functional request is a write, it may update the
 810      * memory value.
 811      */
 812     bool checkFunctional(Printable *obj, Addr base, int size, uint8_t *data);
 813
 814     /**
 815      * Check a functional request against a memory value stored in
 816      * another packet (i.e. an in-transit request or response).
 817      */
 818     bool
 819     checkFunctional(PacketPtr other)
 820     {
 821         uint8_t *data = other->hasData() ? other->getPtr<uint8_t>() : NULL;
 822         return checkFunctional(other, other->getAddr(), other->getSize(),
 823                                data);
 824     }
 825
 826     /**
 827      * Push label for PrintReq (safe to call unconditionally).
 828      */
 829     void
 830     pushLabel(const std::string &lbl)
 831     {
 832         if (isPrint())
 833             safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
 834     }
 835
 836     /**
 837      * Pop label for PrintReq (safe to call unconditionally).
 838      */
 839     void
 840     popLabel()
 841     {
 842         if (isPrint())
 843             safe_cast<PrintReqState*>(senderState)->popLabel();
 844     }
 845
 846     void print(std::ostream &o, int verbosity = 0,
 847                const std::string &prefix = "") const;
 848 };
 849
 850 #endif //__MEM_PACKET_HH