packet.hh revision 7550
1/*
2 * Copyright (c) 2006 The Regents of The University of Michigan
3 * Copyright (c) 2010 Advancec 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 <cassert>
43#include <list>
44#include <bitset>
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
56struct Packet;
57typedef Packet *PacketPtr;
58typedef uint8_t* PacketDataPtr;
59typedef std::list<PacketPtr> PacketList;
60
61class 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        StoreCondResp,
94        SwapReq,
95        SwapResp,
96        MessageReq,
97        MessageResp,
98        // Error responses
99        // @TODO these should be classified as responses rather than
100        // requests; coding them as requests initially for backwards
101        // compatibility
102        NetworkNackError,  // nacked at network layer (not by protocol)
103        InvalidDestError,  // packet dest field invalid
104        BadAddressError,   // memory address invalid
105        // Fake simulator-only commands
106        PrintReq,       // Print state matching address
107        NUM_MEM_CMDS
108    };
109
110  private:
111    /**
112     * List of command attributes.
113     */
114    enum Attribute
115    {
116        IsRead,         //!< Data flows from responder to requester
117        IsWrite,        //!< Data flows from requester to responder
118        IsUpgrade,
119        IsPrefetch,     //!< Not a demand access
120        IsInvalidate,
121        NeedsExclusive, //!< Requires exclusive copy to complete in-cache
122        IsRequest,      //!< Issued by requester
123        IsResponse,     //!< Issue by responder
124        NeedsResponse,  //!< Requester needs response from target
125        IsSWPrefetch,
126        IsHWPrefetch,
127        IsLlsc,         //!< Alpha/MIPS LL or SC access
128        HasData,        //!< There is an associated payload
129        IsError,        //!< Error response
130        IsPrint,        //!< Print state matching address (for debugging)
131        NUM_COMMAND_ATTRIBUTES
132    };
133
134    /**
135     * Structure that defines attributes and other data associated
136     * with a Command.
137     */
138    struct CommandInfo
139    {
140        /// Set of attribute flags.
141        const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
142        /// Corresponding response for requests; InvalidCmd if no
143        /// response is applicable.
144        const Command response;
145        /// String representation (for printing)
146        const std::string str;
147    };
148
149    /// Array to map Command enum to associated info.
150    static const CommandInfo commandInfo[];
151
152  private:
153
154    Command cmd;
155
156    bool
157    testCmdAttrib(MemCmd::Attribute attrib) const
158    {
159        return commandInfo[cmd].attributes[attrib] != 0;
160    }
161
162  public:
163
164    bool isRead() const         { return testCmdAttrib(IsRead); }
165    bool isWrite() const        { return testCmdAttrib(IsWrite); }
166    bool isUpgrade() const      { return testCmdAttrib(IsUpgrade); }
167    bool isRequest() const      { return testCmdAttrib(IsRequest); }
168    bool isResponse() const     { return testCmdAttrib(IsResponse); }
169    bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); }
170    bool needsResponse() const  { return testCmdAttrib(NeedsResponse); }
171    bool isInvalidate() const   { return testCmdAttrib(IsInvalidate); }
172    bool hasData() const        { return testCmdAttrib(HasData); }
173    bool isReadWrite() const    { return isRead() && isWrite(); }
174    bool isLLSC() const         { return testCmdAttrib(IsLlsc); }
175    bool isError() const        { return testCmdAttrib(IsError); }
176    bool isPrint() const        { return testCmdAttrib(IsPrint); }
177
178    const Command
179    responseCommand() const
180    {
181        return commandInfo[cmd].response;
182    }
183
184    /// Return the string to a cmd given by idx.
185    const std::string &toString() const { return commandInfo[cmd].str; }
186    int toInt() const { return (int)cmd; }
187
188    MemCmd(Command _cmd) : cmd(_cmd) { }
189    MemCmd(int _cmd) : cmd((Command)_cmd) { }
190    MemCmd() : cmd(InvalidCmd) { }
191
192    bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
193    bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
194};
195
196/**
197 * A Packet is used to encapsulate a transfer between two objects in
198 * the memory system (e.g., the L1 and L2 cache).  (In contrast, a
199 * single Request travels all the way from the requester to the
200 * ultimate destination and back, possibly being conveyed by several
201 * different Packets along the way.)
202 */
203class Packet : public FastAlloc, public Printable
204{
205  public:
206    typedef uint32_t FlagsType;
207    typedef ::Flags<FlagsType> Flags;
208    typedef short NodeID;
209
210  private:
211    static const FlagsType PUBLIC_FLAGS           = 0x00000000;
212    static const FlagsType PRIVATE_FLAGS          = 0x00007F0F;
213    static const FlagsType COPY_FLAGS             = 0x0000000F;
214
215    static const FlagsType SHARED                 = 0x00000001;
216    // Special control flags
217    /// Special timing-mode atomic snoop for multi-level coherence.
218    static const FlagsType EXPRESS_SNOOP          = 0x00000002;
219    /// Does supplier have exclusive copy?
220    /// Useful for multi-level coherence.
221    static const FlagsType SUPPLY_EXCLUSIVE       = 0x00000004;
222    // Snoop response flags
223    static const FlagsType MEM_INHIBIT            = 0x00000008;
224    /// Are the 'addr' and 'size' fields valid?
225    static const FlagsType VALID_ADDR             = 0x00000100;
226    static const FlagsType VALID_SIZE             = 0x00000200;
227    /// Is the 'src' field valid?
228    static const FlagsType VALID_SRC              = 0x00000400;
229    static const FlagsType VALID_DST              = 0x00000800;
230    /// Is the data pointer set to a value that shouldn't be freed
231    /// when the packet is destroyed?
232    static const FlagsType STATIC_DATA            = 0x00001000;
233    /// The data pointer points to a value that should be freed when
234    /// the packet is destroyed.
235    static const FlagsType DYNAMIC_DATA           = 0x00002000;
236    /// the data pointer points to an array (thus delete []) needs to
237    /// be called on it rather than simply delete.
238    static const FlagsType ARRAY_DATA             = 0x00004000;
239
240    Flags flags;
241
242  public:
243    typedef MemCmd::Command Command;
244
245    /// The command field of the packet.
246    MemCmd cmd;
247
248    /// A pointer to the original request.
249    RequestPtr req;
250
251  private:
252   /**
253    * A pointer to the data being transfered.  It can be differnt
254    * sizes at each level of the heirarchy so it belongs in the
255    * packet, not request. This may or may not be populated when a
256    * responder recieves the packet. If not populated it memory should
257    * be allocated.
258    */
259    PacketDataPtr data;
260
261    /// The address of the request.  This address could be virtual or
262    /// physical, depending on the system configuration.
263    Addr addr;
264
265    /// The size of the request or transfer.
266    unsigned size;
267
268    /**
269     * Device address (e.g., bus ID) of the source of the
270     * transaction. The source is not responsible for setting this
271     * field; it is set implicitly by the interconnect when the packet
272     * is first sent.
273     */
274    NodeID src;
275
276    /**
277     * Device address (e.g., bus ID) of the destination of the
278     * transaction. The special value Broadcast indicates that the
279     * packet should be routed based on its address. This field is
280     * initialized in the constructor and is thus always valid (unlike
281     * addr, size, and src).
282     */
283    NodeID dest;
284
285    /**
286     * The original value of the command field.  Only valid when the
287     * current command field is an error condition; in that case, the
288     * previous contents of the command field are copied here.  This
289     * field is *not* set on non-error responses.
290     */
291    MemCmd origCmd;
292
293  public:
294    /// Used to calculate latencies for each packet.
295    Tick time;
296
297    /// The time at which the packet will be fully transmitted
298    Tick finishTime;
299
300    /// The time at which the first chunk of the packet will be transmitted
301    Tick firstWordTime;
302
303    /// The special destination address indicating that the packet
304    /// should be routed based on its address.
305    static const NodeID Broadcast = -1;
306
307    /**
308     * A virtual base opaque structure used to hold state associated
309     * with the packet but specific to the sending device (e.g., an
310     * MSHR).  A pointer to this state is returned in the packet's
311     * response so that the sender can quickly look up the state
312     * needed to process it.  A specific subclass would be derived
313     * from this to carry state specific to a particular sending
314     * device.
315     */
316    struct SenderState
317    {
318        virtual ~SenderState() {}
319    };
320
321    /**
322     * Object used to maintain state of a PrintReq.  The senderState
323     * field of a PrintReq should always be of this type.
324     */
325    class PrintReqState : public SenderState, public FastAlloc
326    {
327      private:
328        /**
329         * An entry in the label stack.
330         */
331        struct LabelStackEntry
332        {
333            const std::string label;
334            std::string *prefix;
335            bool labelPrinted;
336            LabelStackEntry(const std::string &_label, std::string *_prefix);
337        };
338
339        typedef std::list<LabelStackEntry> LabelStack;
340        LabelStack labelStack;
341
342        std::string *curPrefixPtr;
343
344      public:
345        std::ostream &os;
346        const int verbosity;
347
348        PrintReqState(std::ostream &os, int verbosity = 0);
349        ~PrintReqState();
350
351        /**
352         * Returns the current line prefix.
353         */
354        const std::string &curPrefix() { return *curPrefixPtr; }
355
356        /**
357         * Push a label onto the label stack, and prepend the given
358         * prefix string onto the current prefix.  Labels will only be
359         * printed if an object within the label's scope is printed.
360         */
361        void pushLabel(const std::string &lbl,
362                       const std::string &prefix = "  ");
363
364        /**
365         * Pop a label off the label stack.
366         */
367        void popLabel();
368
369        /**
370         * Print all of the pending unprinted labels on the
371         * stack. Called by printObj(), so normally not called by
372         * users unless bypassing printObj().
373         */
374        void printLabels();
375
376        /**
377         * Print a Printable object to os, because it matched the
378         * address on a PrintReq.
379         */
380        void printObj(Printable *obj);
381    };
382
383    /**
384     * This packet's sender state.  Devices should use dynamic_cast<>
385     * to cast to the state appropriate to the sender.  The intent of
386     * this variable is to allow a device to attach extra information
387     * to a request.  A response packet must return the sender state
388     * that was attached to the original request (even if a new packet
389     * is created).
390     */
391    SenderState *senderState;
392
393    /// Return the string name of the cmd field (for debugging and
394    /// tracing).
395    const std::string &cmdString() const { return cmd.toString(); }
396
397    /// Return the index of this command.
398    inline int cmdToIndex() const { return cmd.toInt(); }
399
400    bool isRead() const         { return cmd.isRead(); }
401    bool isWrite() const        { return cmd.isWrite(); }
402    bool isUpgrade()  const     { return cmd.isUpgrade(); }
403    bool isRequest() const      { return cmd.isRequest(); }
404    bool isResponse() const     { return cmd.isResponse(); }
405    bool needsExclusive() const { return cmd.needsExclusive(); }
406    bool needsResponse() const  { return cmd.needsResponse(); }
407    bool isInvalidate() const   { return cmd.isInvalidate(); }
408    bool hasData() const        { return cmd.hasData(); }
409    bool isReadWrite() const    { return cmd.isReadWrite(); }
410    bool isLLSC() const         { return cmd.isLLSC(); }
411    bool isError() const        { return cmd.isError(); }
412    bool isPrint() const        { return cmd.isPrint(); }
413
414    // Snoop flags
415    void assertMemInhibit()     { flags.set(MEM_INHIBIT); }
416    bool memInhibitAsserted()   { return flags.isSet(MEM_INHIBIT); }
417    void assertShared()         { flags.set(SHARED); }
418    bool sharedAsserted()       { return flags.isSet(SHARED); }
419
420    // Special control flags
421    void setExpressSnoop()      { flags.set(EXPRESS_SNOOP); }
422    bool isExpressSnoop()       { return flags.isSet(EXPRESS_SNOOP); }
423    void setSupplyExclusive()   { flags.set(SUPPLY_EXCLUSIVE); }
424    bool isSupplyExclusive()    { return flags.isSet(SUPPLY_EXCLUSIVE); }
425
426    // Network error conditions... encapsulate them as methods since
427    // their encoding keeps changing (from result field to command
428    // field, etc.)
429    void
430    setNacked()
431    {
432        assert(isResponse());
433        cmd = MemCmd::NetworkNackError;
434    }
435
436    void
437    setBadAddress()
438    {
439        assert(isResponse());
440        cmd = MemCmd::BadAddressError;
441    }
442
443    bool wasNacked() const     { return cmd == MemCmd::NetworkNackError; }
444    bool hadBadAddress() const { return cmd == MemCmd::BadAddressError; }
445    void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
446
447    bool isSrcValid() { return flags.isSet(VALID_SRC); }
448    /// Accessor function to get the source index of the packet.
449    NodeID getSrc() const    { assert(flags.isSet(VALID_SRC)); return src; }
450    /// Accessor function to set the source index of the packet.
451    void setSrc(NodeID _src) { src = _src; flags.set(VALID_SRC); }
452    /// Reset source field, e.g. to retransmit packet on different bus.
453    void clearSrc() { flags.clear(VALID_SRC); }
454
455    bool isDestValid() { return flags.isSet(VALID_DST); }
456    /// Accessor function for the destination index of the packet.
457    NodeID getDest() const     { assert(flags.isSet(VALID_DST)); return dest; }
458    /// Accessor function to set the destination index of the packet.
459    void setDest(NodeID _dest) { dest = _dest; flags.set(VALID_DST); }
460
461    Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
462    unsigned getSize() const  { assert(flags.isSet(VALID_SIZE)); return size; }
463    Addr getOffset(int blkSize) const { return getAddr() & (Addr)(blkSize - 1); }
464
465    /**
466     * It has been determined that the SC packet should successfully update
467     * memory.  Therefore, convert this SC packet to a normal write.
468     */
469    void
470    convertScToWrite()
471    {
472        assert(isLLSC());
473        assert(isWrite());
474        cmd = MemCmd::WriteReq;
475    }
476
477    /**
478     * When ruby is in use, Ruby will monitor the cache line and thus M5
479     * phys memory should treat LL ops as normal reads.
480     */
481    void
482    convertLlToRead()
483    {
484        assert(isLLSC());
485        assert(isRead());
486        cmd = MemCmd::ReadReq;
487    }
488
489    /**
490     * Constructor.  Note that a Request object must be constructed
491     * first, but the Requests's physical address and size fields need
492     * not be valid. The command and destination addresses must be
493     * supplied.
494     */
495    Packet(Request *_req, MemCmd _cmd, NodeID _dest)
496        :  flags(VALID_DST), cmd(_cmd), req(_req), data(NULL),
497           dest(_dest), time(curTick), senderState(NULL)
498    {
499        if (req->hasPaddr()) {
500            addr = req->getPaddr();
501            flags.set(VALID_ADDR);
502        }
503        if (req->hasSize()) {
504            size = req->getSize();
505            flags.set(VALID_SIZE);
506        }
507    }
508
509    /**
510     * Alternate constructor if you are trying to create a packet with
511     * a request that is for a whole block, not the address from the
512     * req.  this allows for overriding the size/addr of the req.
513     */
514    Packet(Request *_req, MemCmd _cmd, NodeID _dest, int _blkSize)
515        :  flags(VALID_DST), cmd(_cmd), req(_req), data(NULL),
516           dest(_dest), time(curTick), senderState(NULL)
517    {
518        if (req->hasPaddr()) {
519            addr = req->getPaddr() & ~(_blkSize - 1);
520            flags.set(VALID_ADDR);
521        }
522        size = _blkSize;
523        flags.set(VALID_SIZE);
524    }
525
526    /**
527     * Alternate constructor for copying a packet.  Copy all fields
528     * *except* if the original packet's data was dynamic, don't copy
529     * that, as we can't guarantee that the new packet's lifetime is
530     * less than that of the original packet.  In this case the new
531     * packet should allocate its own data.
532     */
533    Packet(Packet *pkt, bool clearFlags = false)
534        :  cmd(pkt->cmd), req(pkt->req),
535           data(pkt->flags.isSet(STATIC_DATA) ? pkt->data : NULL),
536           addr(pkt->addr), size(pkt->size), src(pkt->src), dest(pkt->dest),
537           time(curTick), senderState(pkt->senderState)
538    {
539        if (!clearFlags)
540            flags.set(pkt->flags & COPY_FLAGS);
541
542        flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE|VALID_SRC|VALID_DST));
543        flags.set(pkt->flags & STATIC_DATA);
544    }
545
546    /**
547     * clean up packet variables
548     */
549    ~Packet()
550    {
551        // If this is a request packet for which there's no response,
552        // delete the request object here, since the requester will
553        // never get the chance.
554        if (req && isRequest() && !needsResponse())
555            delete req;
556        deleteData();
557    }
558
559    /**
560     * Reinitialize packet address and size from the associated
561     * Request object, and reset other fields that may have been
562     * modified by a previous transaction.  Typically called when a
563     * statically allocated Request/Packet pair is reused for multiple
564     * transactions.
565     */
566    void
567    reinitFromRequest()
568    {
569        assert(req->hasPaddr());
570        flags = 0;
571        addr = req->getPaddr();
572        size = req->getSize();
573        time = req->time();
574
575        flags.set(VALID_ADDR|VALID_SIZE);
576        deleteData();
577    }
578
579    /**
580     * Take a request packet and modify it in place to be suitable for
581     * returning as a response to that request.  The source and
582     * destination fields are *not* modified, as is appropriate for
583     * atomic accesses.
584     */
585    void
586    makeResponse()
587    {
588        assert(needsResponse());
589        assert(isRequest());
590        origCmd = cmd;
591        cmd = cmd.responseCommand();
592
593        // responses are never express, even if the snoop that
594        // triggered them was
595        flags.clear(EXPRESS_SNOOP);
596
597        dest = src;
598        flags.set(VALID_DST, flags.isSet(VALID_SRC));
599        flags.clear(VALID_SRC);
600    }
601
602    void
603    makeAtomicResponse()
604    {
605        makeResponse();
606    }
607
608    void
609    makeTimingResponse()
610    {
611        makeResponse();
612    }
613
614    /**
615     * Take a request packet that has been returned as NACKED and
616     * modify it so that it can be sent out again. Only packets that
617     * need a response can be NACKED, so verify that that is true.
618     */
619    void
620    reinitNacked()
621    {
622        assert(wasNacked());
623        cmd = origCmd;
624        assert(needsResponse());
625        setDest(Broadcast);
626    }
627
628    void
629    setSize(unsigned size)
630    {
631        assert(!flags.isSet(VALID_SIZE));
632
633        this->size = size;
634        flags.set(VALID_SIZE);
635    }
636
637
638    /**
639     * Set the data pointer to the following value that should not be
640     * freed.
641     */
642    template <typename T>
643    void
644    dataStatic(T *p)
645    {
646        assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
647        data = (PacketDataPtr)p;
648        flags.set(STATIC_DATA);
649    }
650
651    /**
652     * Set the data pointer to a value that should have delete []
653     * called on it.
654     */
655    template <typename T>
656    void
657    dataDynamicArray(T *p)
658    {
659        assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
660        data = (PacketDataPtr)p;
661        flags.set(DYNAMIC_DATA|ARRAY_DATA);
662    }
663
664    /**
665     * set the data pointer to a value that should have delete called
666     * on it.
667     */
668    template <typename T>
669    void
670    dataDynamic(T *p)
671    {
672        assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
673        data = (PacketDataPtr)p;
674        flags.set(DYNAMIC_DATA);
675    }
676
677    /**
678     * get a pointer to the data ptr.
679     */
680    template <typename T>
681    T*
682    getPtr()
683    {
684        assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
685        return (T*)data;
686    }
687
688    /**
689     * return the value of what is pointed to in the packet.
690     */
691    template <typename T>
692    T get();
693
694    /**
695     * set the value in the data pointer to v.
696     */
697    template <typename T>
698    void set(T v);
699
700    /**
701     * Copy data into the packet from the provided pointer.
702     */
703    void
704    setData(uint8_t *p)
705    {
706        std::memcpy(getPtr<uint8_t>(), p, getSize());
707    }
708
709    /**
710     * Copy data into the packet from the provided block pointer,
711     * which is aligned to the given block size.
712     */
713    void
714    setDataFromBlock(uint8_t *blk_data, int blkSize)
715    {
716        setData(blk_data + getOffset(blkSize));
717    }
718
719    /**
720     * Copy data from the packet to the provided block pointer, which
721     * is aligned to the given block size.
722     */
723    void
724    writeData(uint8_t *p)
725    {
726        std::memcpy(p, getPtr<uint8_t>(), getSize());
727    }
728
729    /**
730     * Copy data from the packet to the memory at the provided pointer.
731     */
732    void
733    writeDataToBlock(uint8_t *blk_data, int blkSize)
734    {
735        writeData(blk_data + getOffset(blkSize));
736    }
737
738    /**
739     * delete the data pointed to in the data pointer. Ok to call to
740     * matter how data was allocted.
741     */
742    void
743    deleteData()
744    {
745        if (flags.isSet(ARRAY_DATA))
746            delete [] data;
747        else if (flags.isSet(DYNAMIC_DATA))
748            delete data;
749
750        flags.clear(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA);
751        data = NULL;
752    }
753
754    /** If there isn't data in the packet, allocate some. */
755    void
756    allocate()
757    {
758        if (data) {
759            assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
760            return;
761        }
762
763        assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
764        flags.set(DYNAMIC_DATA|ARRAY_DATA);
765        data = new uint8_t[getSize()];
766    }
767
768
769    /**
770     * Check a functional request against a memory value represented
771     * by a base/size pair and an associated data array.  If the
772     * functional request is a read, it may be satisfied by the memory
773     * value.  If the functional request is a write, it may update the
774     * memory value.
775     */
776    bool checkFunctional(Printable *obj, Addr base, int size, uint8_t *data);
777
778    /**
779     * Check a functional request against a memory value stored in
780     * another packet (i.e. an in-transit request or response).
781     */
782    bool
783    checkFunctional(PacketPtr other)
784    {
785        uint8_t *data = other->hasData() ? other->getPtr<uint8_t>() : NULL;
786        return checkFunctional(other, other->getAddr(), other->getSize(),
787                               data);
788    }
789
790    /**
791     * Push label for PrintReq (safe to call unconditionally).
792     */
793    void
794    pushLabel(const std::string &lbl)
795    {
796        if (isPrint())
797            safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
798    }
799
800    /**
801     * Pop label for PrintReq (safe to call unconditionally).
802     */
803    void
804    popLabel()
805    {
806        if (isPrint())
807            safe_cast<PrintReqState*>(senderState)->popLabel();
808    }
809
810    void print(std::ostream &o, int verbosity = 0,
811               const std::string &prefix = "") const;
812};
813
814#endif //__MEM_PACKET_HH
815