packet.hh revision 13954
1/*
2 * Copyright (c) 2012-2019 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2006 The Regents of The University of Michigan
15 * Copyright (c) 2010,2015 Advanced Micro Devices, Inc.
16 * All rights reserved.
17 *
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions are
20 * met: redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer;
22 * redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution;
25 * neither the name of the copyright holders nor the names of its
26 * contributors may be used to endorse or promote products derived from
27 * this software without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
30 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
31 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
32 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
33 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
34 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
35 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
39 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
40 *
41 * Authors: Ron Dreslinski
42 *          Steve Reinhardt
43 *          Ali Saidi
44 *          Andreas Hansson
45 *          Nikos Nikoleris
46 */
47
48/**
49 * @file
50 * Declaration of the Packet class.
51 */
52
53#ifndef __MEM_PACKET_HH__
54#define __MEM_PACKET_HH__
55
56#include <bitset>
57#include <cassert>
58#include <list>
59
60#include "base/addr_range.hh"
61#include "base/cast.hh"
62#include "base/compiler.hh"
63#include "base/flags.hh"
64#include "base/logging.hh"
65#include "base/printable.hh"
66#include "base/types.hh"
67#include "config/the_isa.hh"
68#include "mem/request.hh"
69#include "sim/core.hh"
70
71class Packet;
72typedef Packet *PacketPtr;
73typedef uint8_t* PacketDataPtr;
74typedef std::list<PacketPtr> PacketList;
75typedef uint64_t PacketId;
76
77class MemCmd
78{
79    friend class Packet;
80
81  public:
82    /**
83     * List of all commands associated with a packet.
84     */
85    enum Command
86    {
87        InvalidCmd,
88        ReadReq,
89        ReadResp,
90        ReadRespWithInvalidate,
91        WriteReq,
92        WriteResp,
93        WritebackDirty,
94        WritebackClean,
95        WriteClean,            // writes dirty data below without evicting
96        CleanEvict,
97        SoftPFReq,
98        SoftPFExReq,
99        HardPFReq,
100        SoftPFResp,
101        HardPFResp,
102        WriteLineReq,
103        UpgradeReq,
104        SCUpgradeReq,           // Special "weak" upgrade for StoreCond
105        UpgradeResp,
106        SCUpgradeFailReq,       // Failed SCUpgradeReq in MSHR (never sent)
107        UpgradeFailResp,        // Valid for SCUpgradeReq only
108        ReadExReq,
109        ReadExResp,
110        ReadCleanReq,
111        ReadSharedReq,
112        LoadLockedReq,
113        StoreCondReq,
114        StoreCondFailReq,       // Failed StoreCondReq in MSHR (never sent)
115        StoreCondResp,
116        SwapReq,
117        SwapResp,
118        MessageReq,
119        MessageResp,
120        MemFenceReq,
121        MemFenceResp,
122        CleanSharedReq,
123        CleanSharedResp,
124        CleanInvalidReq,
125        CleanInvalidResp,
126        // Error responses
127        // @TODO these should be classified as responses rather than
128        // requests; coding them as requests initially for backwards
129        // compatibility
130        InvalidDestError,  // packet dest field invalid
131        BadAddressError,   // memory address invalid
132        FunctionalReadError, // unable to fulfill functional read
133        FunctionalWriteError, // unable to fulfill functional write
134        // Fake simulator-only commands
135        PrintReq,       // Print state matching address
136        FlushReq,      //request for a cache flush
137        InvalidateReq,   // request for address to be invalidated
138        InvalidateResp,
139        NUM_MEM_CMDS
140    };
141
142  private:
143    /**
144     * List of command attributes.
145     */
146    enum Attribute
147    {
148        IsRead,         //!< Data flows from responder to requester
149        IsWrite,        //!< Data flows from requester to responder
150        IsUpgrade,
151        IsInvalidate,
152        IsClean,        //!< Cleans any existing dirty blocks
153        NeedsWritable,  //!< Requires writable copy to complete in-cache
154        IsRequest,      //!< Issued by requester
155        IsResponse,     //!< Issue by responder
156        NeedsResponse,  //!< Requester needs response from target
157        IsEviction,
158        IsSWPrefetch,
159        IsHWPrefetch,
160        IsLlsc,         //!< Alpha/MIPS LL or SC access
161        HasData,        //!< There is an associated payload
162        IsError,        //!< Error response
163        IsPrint,        //!< Print state matching address (for debugging)
164        IsFlush,        //!< Flush the address from caches
165        FromCache,      //!< Request originated from a caching agent
166        NUM_COMMAND_ATTRIBUTES
167    };
168
169    /**
170     * Structure that defines attributes and other data associated
171     * with a Command.
172     */
173    struct CommandInfo
174    {
175        /// Set of attribute flags.
176        const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
177        /// Corresponding response for requests; InvalidCmd if no
178        /// response is applicable.
179        const Command response;
180        /// String representation (for printing)
181        const std::string str;
182    };
183
184    /// Array to map Command enum to associated info.
185    static const CommandInfo commandInfo[];
186
187  private:
188
189    Command cmd;
190
191    bool
192    testCmdAttrib(MemCmd::Attribute attrib) const
193    {
194        return commandInfo[cmd].attributes[attrib] != 0;
195    }
196
197  public:
198
199    bool isRead() const            { return testCmdAttrib(IsRead); }
200    bool isWrite() const           { return testCmdAttrib(IsWrite); }
201    bool isUpgrade() const         { return testCmdAttrib(IsUpgrade); }
202    bool isRequest() const         { return testCmdAttrib(IsRequest); }
203    bool isResponse() const        { return testCmdAttrib(IsResponse); }
204    bool needsWritable() const     { return testCmdAttrib(NeedsWritable); }
205    bool needsResponse() const     { return testCmdAttrib(NeedsResponse); }
206    bool isInvalidate() const      { return testCmdAttrib(IsInvalidate); }
207    bool isEviction() const        { return testCmdAttrib(IsEviction); }
208    bool isClean() const           { return testCmdAttrib(IsClean); }
209    bool fromCache() const         { return testCmdAttrib(FromCache); }
210
211    /**
212     * A writeback is an eviction that carries data.
213     */
214    bool isWriteback() const       { return testCmdAttrib(IsEviction) &&
215                                            testCmdAttrib(HasData); }
216
217    /**
218     * Check if this particular packet type carries payload data. Note
219     * that this does not reflect if the data pointer of the packet is
220     * valid or not.
221     */
222    bool hasData() const        { return testCmdAttrib(HasData); }
223    bool isLLSC() const         { return testCmdAttrib(IsLlsc); }
224    bool isSWPrefetch() const   { return testCmdAttrib(IsSWPrefetch); }
225    bool isHWPrefetch() const   { return testCmdAttrib(IsHWPrefetch); }
226    bool isPrefetch() const     { return testCmdAttrib(IsSWPrefetch) ||
227                                         testCmdAttrib(IsHWPrefetch); }
228    bool isError() const        { return testCmdAttrib(IsError); }
229    bool isPrint() const        { return testCmdAttrib(IsPrint); }
230    bool isFlush() const        { return testCmdAttrib(IsFlush); }
231
232    Command
233    responseCommand() const
234    {
235        return commandInfo[cmd].response;
236    }
237
238    /// Return the string to a cmd given by idx.
239    const std::string &toString() const { return commandInfo[cmd].str; }
240    int toInt() const { return (int)cmd; }
241
242    MemCmd(Command _cmd) : cmd(_cmd) { }
243    MemCmd(int _cmd) : cmd((Command)_cmd) { }
244    MemCmd() : cmd(InvalidCmd) { }
245
246    bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
247    bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
248};
249
250/**
251 * A Packet is used to encapsulate a transfer between two objects in
252 * the memory system (e.g., the L1 and L2 cache).  (In contrast, a
253 * single Request travels all the way from the requester to the
254 * ultimate destination and back, possibly being conveyed by several
255 * different Packets along the way.)
256 */
257class Packet : public Printable
258{
259  public:
260    typedef uint32_t FlagsType;
261    typedef ::Flags<FlagsType> Flags;
262
263  private:
264
265    enum : FlagsType {
266        // Flags to transfer across when copying a packet
267        COPY_FLAGS             = 0x0000003F,
268
269        // Flags that are used to create reponse packets
270        RESPONDER_FLAGS        = 0x00000009,
271
272        // Does this packet have sharers (which means it should not be
273        // considered writable) or not. See setHasSharers below.
274        HAS_SHARERS            = 0x00000001,
275
276        // Special control flags
277        /// Special timing-mode atomic snoop for multi-level coherence.
278        EXPRESS_SNOOP          = 0x00000002,
279
280        /// Allow a responding cache to inform the cache hierarchy
281        /// that it had a writable copy before responding. See
282        /// setResponderHadWritable below.
283        RESPONDER_HAD_WRITABLE = 0x00000004,
284
285        // Snoop co-ordination flag to indicate that a cache is
286        // responding to a snoop. See setCacheResponding below.
287        CACHE_RESPONDING       = 0x00000008,
288
289        // The writeback/writeclean should be propagated further
290        // downstream by the receiver
291        WRITE_THROUGH          = 0x00000010,
292
293        // Response co-ordination flag for cache maintenance
294        // operations
295        SATISFIED              = 0x00000020,
296
297        /// Are the 'addr' and 'size' fields valid?
298        VALID_ADDR             = 0x00000100,
299        VALID_SIZE             = 0x00000200,
300
301        /// Is the data pointer set to a value that shouldn't be freed
302        /// when the packet is destroyed?
303        STATIC_DATA            = 0x00001000,
304        /// The data pointer points to a value that should be freed when
305        /// the packet is destroyed. The pointer is assumed to be pointing
306        /// to an array, and delete [] is consequently called
307        DYNAMIC_DATA           = 0x00002000,
308
309        /// suppress the error if this packet encounters a functional
310        /// access failure.
311        SUPPRESS_FUNC_ERROR    = 0x00008000,
312
313        // Signal block present to squash prefetch and cache evict packets
314        // through express snoop flag
315        BLOCK_CACHED          = 0x00010000
316    };
317
318    Flags flags;
319
320  public:
321    typedef MemCmd::Command Command;
322
323    /// The command field of the packet.
324    MemCmd cmd;
325
326    const PacketId id;
327
328    /// A pointer to the original request.
329    RequestPtr req;
330
331  private:
332   /**
333    * A pointer to the data being transferred. It can be different
334    * sizes at each level of the hierarchy so it belongs to the
335    * packet, not request. This may or may not be populated when a
336    * responder receives the packet. If not populated memory should
337    * be allocated.
338    */
339    PacketDataPtr data;
340
341    /// The address of the request.  This address could be virtual or
342    /// physical, depending on the system configuration.
343    Addr addr;
344
345    /// True if the request targets the secure memory space.
346    bool _isSecure;
347
348    /// The size of the request or transfer.
349    unsigned size;
350
351    /**
352     * Track the bytes found that satisfy a functional read.
353     */
354    std::vector<bool> bytesValid;
355
356    // Quality of Service priority value
357    uint8_t _qosValue;
358
359  public:
360
361    /**
362     * The extra delay from seeing the packet until the header is
363     * transmitted. This delay is used to communicate the crossbar
364     * forwarding latency to the neighbouring object (e.g. a cache)
365     * that actually makes the packet wait. As the delay is relative,
366     * a 32-bit unsigned should be sufficient.
367     */
368    uint32_t headerDelay;
369
370    /**
371     * Keep track of the extra delay incurred by snooping upwards
372     * before sending a request down the memory system. This is used
373     * by the coherent crossbar to account for the additional request
374     * delay.
375     */
376    uint32_t snoopDelay;
377
378    /**
379     * The extra pipelining delay from seeing the packet until the end of
380     * payload is transmitted by the component that provided it (if
381     * any). This includes the header delay. Similar to the header
382     * delay, this is used to make up for the fact that the
383     * crossbar does not make the packet wait. As the delay is
384     * relative, a 32-bit unsigned should be sufficient.
385     */
386    uint32_t payloadDelay;
387
388    /**
389     * A virtual base opaque structure used to hold state associated
390     * with the packet (e.g., an MSHR), specific to a SimObject that
391     * sees the packet. A pointer to this state is returned in the
392     * packet's response so that the SimObject in question can quickly
393     * look up the state needed to process it. A specific subclass
394     * would be derived from this to carry state specific to a
395     * particular sending device.
396     *
397     * As multiple SimObjects may add their SenderState throughout the
398     * memory system, the SenderStates create a stack, where a
399     * SimObject can add a new Senderstate, as long as the
400     * predecessing SenderState is restored when the response comes
401     * back. For this reason, the predecessor should always be
402     * populated with the current SenderState of a packet before
403     * modifying the senderState field in the request packet.
404     */
405    struct SenderState
406    {
407        SenderState* predecessor;
408        SenderState() : predecessor(NULL) {}
409        virtual ~SenderState() {}
410    };
411
412    /**
413     * Object used to maintain state of a PrintReq.  The senderState
414     * field of a PrintReq should always be of this type.
415     */
416    class PrintReqState : public SenderState
417    {
418      private:
419        /**
420         * An entry in the label stack.
421         */
422        struct LabelStackEntry
423        {
424            const std::string label;
425            std::string *prefix;
426            bool labelPrinted;
427            LabelStackEntry(const std::string &_label, std::string *_prefix);
428        };
429
430        typedef std::list<LabelStackEntry> LabelStack;
431        LabelStack labelStack;
432
433        std::string *curPrefixPtr;
434
435      public:
436        std::ostream &os;
437        const int verbosity;
438
439        PrintReqState(std::ostream &os, int verbosity = 0);
440        ~PrintReqState();
441
442        /**
443         * Returns the current line prefix.
444         */
445        const std::string &curPrefix() { return *curPrefixPtr; }
446
447        /**
448         * Push a label onto the label stack, and prepend the given
449         * prefix string onto the current prefix.  Labels will only be
450         * printed if an object within the label's scope is printed.
451         */
452        void pushLabel(const std::string &lbl,
453                       const std::string &prefix = "  ");
454
455        /**
456         * Pop a label off the label stack.
457         */
458        void popLabel();
459
460        /**
461         * Print all of the pending unprinted labels on the
462         * stack. Called by printObj(), so normally not called by
463         * users unless bypassing printObj().
464         */
465        void printLabels();
466
467        /**
468         * Print a Printable object to os, because it matched the
469         * address on a PrintReq.
470         */
471        void printObj(Printable *obj);
472    };
473
474    /**
475     * This packet's sender state.  Devices should use dynamic_cast<>
476     * to cast to the state appropriate to the sender.  The intent of
477     * this variable is to allow a device to attach extra information
478     * to a request. A response packet must return the sender state
479     * that was attached to the original request (even if a new packet
480     * is created).
481     */
482    SenderState *senderState;
483
484    /**
485     * Push a new sender state to the packet and make the current
486     * sender state the predecessor of the new one. This should be
487     * prefered over direct manipulation of the senderState member
488     * variable.
489     *
490     * @param sender_state SenderState to push at the top of the stack
491     */
492    void pushSenderState(SenderState *sender_state);
493
494    /**
495     * Pop the top of the state stack and return a pointer to it. This
496     * assumes the current sender state is not NULL. This should be
497     * preferred over direct manipulation of the senderState member
498     * variable.
499     *
500     * @return The current top of the stack
501     */
502    SenderState *popSenderState();
503
504    /**
505     * Go through the sender state stack and return the first instance
506     * that is of type T (as determined by a dynamic_cast). If there
507     * is no sender state of type T, NULL is returned.
508     *
509     * @return The topmost state of type T
510     */
511    template <typename T>
512    T * findNextSenderState() const
513    {
514        T *t = NULL;
515        SenderState* sender_state = senderState;
516        while (t == NULL && sender_state != NULL) {
517            t = dynamic_cast<T*>(sender_state);
518            sender_state = sender_state->predecessor;
519        }
520        return t;
521    }
522
523    /// Return the string name of the cmd field (for debugging and
524    /// tracing).
525    const std::string &cmdString() const { return cmd.toString(); }
526
527    /// Return the index of this command.
528    inline int cmdToIndex() const { return cmd.toInt(); }
529
530    bool isRead() const              { return cmd.isRead(); }
531    bool isWrite() const             { return cmd.isWrite(); }
532    bool isUpgrade()  const          { return cmd.isUpgrade(); }
533    bool isRequest() const           { return cmd.isRequest(); }
534    bool isResponse() const          { return cmd.isResponse(); }
535    bool needsWritable() const
536    {
537        // we should never check if a response needsWritable, the
538        // request has this flag, and for a response we should rather
539        // look at the hasSharers flag (if not set, the response is to
540        // be considered writable)
541        assert(isRequest());
542        return cmd.needsWritable();
543    }
544    bool needsResponse() const       { return cmd.needsResponse(); }
545    bool isInvalidate() const        { return cmd.isInvalidate(); }
546    bool isEviction() const          { return cmd.isEviction(); }
547    bool isClean() const             { return cmd.isClean(); }
548    bool fromCache() const           { return cmd.fromCache(); }
549    bool isWriteback() const         { return cmd.isWriteback(); }
550    bool hasData() const             { return cmd.hasData(); }
551    bool hasRespData() const
552    {
553        MemCmd resp_cmd = cmd.responseCommand();
554        return resp_cmd.hasData();
555    }
556    bool isLLSC() const              { return cmd.isLLSC(); }
557    bool isError() const             { return cmd.isError(); }
558    bool isPrint() const             { return cmd.isPrint(); }
559    bool isFlush() const             { return cmd.isFlush(); }
560
561    bool isWholeLineWrite(unsigned blk_size)
562    {
563        return (cmd == MemCmd::WriteReq || cmd == MemCmd::WriteLineReq) &&
564            getOffset(blk_size) == 0 && getSize() == blk_size;
565    }
566
567    //@{
568    /// Snoop flags
569    /**
570     * Set the cacheResponding flag. This is used by the caches to
571     * signal another cache that they are responding to a request. A
572     * cache will only respond to snoops if it has the line in either
573     * Modified or Owned state. Note that on snoop hits we always pass
574     * the line as Modified and never Owned. In the case of an Owned
575     * line we proceed to invalidate all other copies.
576     *
577     * On a cache fill (see Cache::handleFill), we check hasSharers
578     * first, ignoring the cacheResponding flag if hasSharers is set.
579     * A line is consequently allocated as:
580     *
581     * hasSharers cacheResponding state
582     * true       false           Shared
583     * true       true            Shared
584     * false      false           Exclusive
585     * false      true            Modified
586     */
587    void setCacheResponding()
588    {
589        assert(isRequest());
590        assert(!flags.isSet(CACHE_RESPONDING));
591        flags.set(CACHE_RESPONDING);
592    }
593    bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); }
594    /**
595     * On fills, the hasSharers flag is used by the caches in
596     * combination with the cacheResponding flag, as clarified
597     * above. If the hasSharers flag is not set, the packet is passing
598     * writable. Thus, a response from a memory passes the line as
599     * writable by default.
600     *
601     * The hasSharers flag is also used by upstream caches to inform a
602     * downstream cache that they have the block (by calling
603     * setHasSharers on snoop request packets that hit in upstream
604     * cachs tags or MSHRs). If the snoop packet has sharers, a
605     * downstream cache is prevented from passing a dirty line upwards
606     * if it was not explicitly asked for a writable copy. See
607     * Cache::satisfyCpuSideRequest.
608     *
609     * The hasSharers flag is also used on writebacks, in
610     * combination with the WritbackClean or WritebackDirty commands,
611     * to allocate the block downstream either as:
612     *
613     * command        hasSharers state
614     * WritebackDirty false      Modified
615     * WritebackDirty true       Owned
616     * WritebackClean false      Exclusive
617     * WritebackClean true       Shared
618     */
619    void setHasSharers()    { flags.set(HAS_SHARERS); }
620    bool hasSharers() const { return flags.isSet(HAS_SHARERS); }
621    //@}
622
623    /**
624     * The express snoop flag is used for two purposes. Firstly, it is
625     * used to bypass flow control for normal (non-snoop) requests
626     * going downstream in the memory system. In cases where a cache
627     * is responding to a snoop from another cache (it had a dirty
628     * line), but the line is not writable (and there are possibly
629     * other copies), the express snoop flag is set by the downstream
630     * cache to invalidate all other copies in zero time. Secondly,
631     * the express snoop flag is also set to be able to distinguish
632     * snoop packets that came from a downstream cache, rather than
633     * snoop packets from neighbouring caches.
634     */
635    void setExpressSnoop()      { flags.set(EXPRESS_SNOOP); }
636    bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); }
637
638    /**
639     * On responding to a snoop request (which only happens for
640     * Modified or Owned lines), make sure that we can transform an
641     * Owned response to a Modified one. If this flag is not set, the
642     * responding cache had the line in the Owned state, and there are
643     * possibly other Shared copies in the memory system. A downstream
644     * cache helps in orchestrating the invalidation of these copies
645     * by sending out the appropriate express snoops.
646     */
647    void setResponderHadWritable()
648    {
649        assert(cacheResponding());
650        assert(!responderHadWritable());
651        flags.set(RESPONDER_HAD_WRITABLE);
652    }
653    bool responderHadWritable() const
654    { return flags.isSet(RESPONDER_HAD_WRITABLE); }
655
656    /**
657     * Copy the reponse flags from an input packet to this packet. The
658     * reponse flags determine whether a responder has been found and
659     * the state at which the block will be at the destination.
660     *
661     * @pkt The packet that we will copy flags from
662     */
663    void copyResponderFlags(const PacketPtr pkt);
664
665    /**
666     * A writeback/writeclean cmd gets propagated further downstream
667     * by the receiver when the flag is set.
668     */
669    void setWriteThrough()
670    {
671        assert(cmd.isWrite() &&
672               (cmd.isEviction() || cmd == MemCmd::WriteClean));
673        flags.set(WRITE_THROUGH);
674    }
675    void clearWriteThrough() { flags.clear(WRITE_THROUGH); }
676    bool writeThrough() const { return flags.isSet(WRITE_THROUGH); }
677
678    /**
679     * Set when a request hits in a cache and the cache is not going
680     * to respond. This is used by the crossbar to coordinate
681     * responses for cache maintenance operations.
682     */
683    void setSatisfied()
684    {
685        assert(cmd.isClean());
686        assert(!flags.isSet(SATISFIED));
687        flags.set(SATISFIED);
688    }
689    bool satisfied() const { return flags.isSet(SATISFIED); }
690
691    void setSuppressFuncError()     { flags.set(SUPPRESS_FUNC_ERROR); }
692    bool suppressFuncError() const  { return flags.isSet(SUPPRESS_FUNC_ERROR); }
693    void setBlockCached()          { flags.set(BLOCK_CACHED); }
694    bool isBlockCached() const     { return flags.isSet(BLOCK_CACHED); }
695    void clearBlockCached()        { flags.clear(BLOCK_CACHED); }
696
697    /**
698     * QoS Value getter
699     * Returns 0 if QoS value was never set (constructor default).
700     *
701     * @return QoS priority value of the packet
702     */
703    inline uint8_t qosValue() const { return _qosValue; }
704
705    /**
706     * QoS Value setter
707     * Interface for setting QoS priority value of the packet.
708     *
709     * @param qos_value QoS priority value
710     */
711    inline void qosValue(const uint8_t qos_value)
712    { _qosValue = qos_value; }
713
714    inline MasterID masterId() const { return req->masterId(); }
715
716    // Network error conditions... encapsulate them as methods since
717    // their encoding keeps changing (from result field to command
718    // field, etc.)
719    void
720    setBadAddress()
721    {
722        assert(isResponse());
723        cmd = MemCmd::BadAddressError;
724    }
725
726    void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
727
728    Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
729    /**
730     * Update the address of this packet mid-transaction. This is used
731     * by the address mapper to change an already set address to a new
732     * one based on the system configuration. It is intended to remap
733     * an existing address, so it asserts that the current address is
734     * valid.
735     */
736    void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; }
737
738    unsigned getSize() const  { assert(flags.isSet(VALID_SIZE)); return size; }
739
740    /**
741     * Get address range to which this packet belongs.
742     *
743     * @return Address range of this packet.
744     */
745    AddrRange getAddrRange() const;
746
747    Addr getOffset(unsigned int blk_size) const
748    {
749        return getAddr() & Addr(blk_size - 1);
750    }
751
752    Addr getBlockAddr(unsigned int blk_size) const
753    {
754        return getAddr() & ~(Addr(blk_size - 1));
755    }
756
757    bool isSecure() const
758    {
759        assert(flags.isSet(VALID_ADDR));
760        return _isSecure;
761    }
762
763    /**
764     * Accessor function to atomic op.
765     */
766    AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); }
767    bool isAtomicOp() const { return req->isAtomic(); }
768
769    /**
770     * It has been determined that the SC packet should successfully update
771     * memory. Therefore, convert this SC packet to a normal write.
772     */
773    void
774    convertScToWrite()
775    {
776        assert(isLLSC());
777        assert(isWrite());
778        cmd = MemCmd::WriteReq;
779    }
780
781    /**
782     * When ruby is in use, Ruby will monitor the cache line and the
783     * phys memory should treat LL ops as normal reads.
784     */
785    void
786    convertLlToRead()
787    {
788        assert(isLLSC());
789        assert(isRead());
790        cmd = MemCmd::ReadReq;
791    }
792
793    /**
794     * Constructor. Note that a Request object must be constructed
795     * first, but the Requests's physical address and size fields need
796     * not be valid. The command must be supplied.
797     */
798    Packet(const RequestPtr &_req, MemCmd _cmd)
799        :  cmd(_cmd), id((PacketId)_req.get()), req(_req),
800           data(nullptr), addr(0), _isSecure(false), size(0),
801           _qosValue(0), headerDelay(0), snoopDelay(0),
802           payloadDelay(0), senderState(NULL)
803    {
804        if (req->hasPaddr()) {
805            addr = req->getPaddr();
806            flags.set(VALID_ADDR);
807            _isSecure = req->isSecure();
808        }
809        if (req->hasSize()) {
810            size = req->getSize();
811            flags.set(VALID_SIZE);
812        }
813    }
814
815    /**
816     * Alternate constructor if you are trying to create a packet with
817     * a request that is for a whole block, not the address from the
818     * req.  this allows for overriding the size/addr of the req.
819     */
820    Packet(const RequestPtr &_req, MemCmd _cmd, int _blkSize, PacketId _id = 0)
821        :  cmd(_cmd), id(_id ? _id : (PacketId)_req.get()), req(_req),
822           data(nullptr), addr(0), _isSecure(false),
823           _qosValue(0), headerDelay(0),
824           snoopDelay(0), payloadDelay(0), senderState(NULL)
825    {
826        if (req->hasPaddr()) {
827            addr = req->getPaddr() & ~(_blkSize - 1);
828            flags.set(VALID_ADDR);
829            _isSecure = req->isSecure();
830        }
831        size = _blkSize;
832        flags.set(VALID_SIZE);
833    }
834
835    /**
836     * Alternate constructor for copying a packet.  Copy all fields
837     * *except* if the original packet's data was dynamic, don't copy
838     * that, as we can't guarantee that the new packet's lifetime is
839     * less than that of the original packet.  In this case the new
840     * packet should allocate its own data.
841     */
842    Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data)
843        :  cmd(pkt->cmd), id(pkt->id), req(pkt->req),
844           data(nullptr),
845           addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size),
846           bytesValid(pkt->bytesValid),
847           _qosValue(pkt->qosValue()),
848           headerDelay(pkt->headerDelay),
849           snoopDelay(0),
850           payloadDelay(pkt->payloadDelay),
851           senderState(pkt->senderState)
852    {
853        if (!clear_flags)
854            flags.set(pkt->flags & COPY_FLAGS);
855
856        flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE));
857
858        // should we allocate space for data, or not, the express
859        // snoops do not need to carry any data as they only serve to
860        // co-ordinate state changes
861        if (alloc_data) {
862            // even if asked to allocate data, if the original packet
863            // holds static data, then the sender will not be doing
864            // any memcpy on receiving the response, thus we simply
865            // carry the pointer forward
866            if (pkt->flags.isSet(STATIC_DATA)) {
867                data = pkt->data;
868                flags.set(STATIC_DATA);
869            } else {
870                allocate();
871            }
872        }
873    }
874
875    /**
876     * Generate the appropriate read MemCmd based on the Request flags.
877     */
878    static MemCmd
879    makeReadCmd(const RequestPtr &req)
880    {
881        if (req->isLLSC())
882            return MemCmd::LoadLockedReq;
883        else if (req->isPrefetchEx())
884            return MemCmd::SoftPFExReq;
885        else if (req->isPrefetch())
886            return MemCmd::SoftPFReq;
887        else
888            return MemCmd::ReadReq;
889    }
890
891    /**
892     * Generate the appropriate write MemCmd based on the Request flags.
893     */
894    static MemCmd
895    makeWriteCmd(const RequestPtr &req)
896    {
897        if (req->isLLSC())
898            return MemCmd::StoreCondReq;
899        else if (req->isSwap() || req->isAtomic())
900            return MemCmd::SwapReq;
901        else if (req->isCacheInvalidate()) {
902          return req->isCacheClean() ? MemCmd::CleanInvalidReq :
903              MemCmd::InvalidateReq;
904        } else if (req->isCacheClean()) {
905            return MemCmd::CleanSharedReq;
906        } else
907            return MemCmd::WriteReq;
908    }
909
910    /**
911     * Constructor-like methods that return Packets based on Request objects.
912     * Fine-tune the MemCmd type if it's not a vanilla read or write.
913     */
914    static PacketPtr
915    createRead(const RequestPtr &req)
916    {
917        return new Packet(req, makeReadCmd(req));
918    }
919
920    static PacketPtr
921    createWrite(const RequestPtr &req)
922    {
923        return new Packet(req, makeWriteCmd(req));
924    }
925
926    /**
927     * clean up packet variables
928     */
929    ~Packet()
930    {
931        deleteData();
932    }
933
934    /**
935     * Take a request packet and modify it in place to be suitable for
936     * returning as a response to that request.
937     */
938    void
939    makeResponse()
940    {
941        assert(needsResponse());
942        assert(isRequest());
943        cmd = cmd.responseCommand();
944
945        // responses are never express, even if the snoop that
946        // triggered them was
947        flags.clear(EXPRESS_SNOOP);
948    }
949
950    void
951    makeAtomicResponse()
952    {
953        makeResponse();
954    }
955
956    void
957    makeTimingResponse()
958    {
959        makeResponse();
960    }
961
962    void
963    setFunctionalResponseStatus(bool success)
964    {
965        if (!success) {
966            if (isWrite()) {
967                cmd = MemCmd::FunctionalWriteError;
968            } else {
969                cmd = MemCmd::FunctionalReadError;
970            }
971        }
972    }
973
974    void
975    setSize(unsigned size)
976    {
977        assert(!flags.isSet(VALID_SIZE));
978
979        this->size = size;
980        flags.set(VALID_SIZE);
981    }
982
983    /**
984     * Check if packet corresponds to a given block-aligned address and
985     * address space.
986     *
987     * @param addr The address to compare against.
988     * @param is_secure Whether addr belongs to the secure address space.
989     * @param blk_size Block size in bytes.
990     * @return Whether packet matches description.
991     */
992    bool matchBlockAddr(const Addr addr, const bool is_secure,
993                        const int blk_size) const;
994
995    /**
996     * Check if this packet refers to the same block-aligned address and
997     * address space as another packet.
998     *
999     * @param pkt The packet to compare against.
1000     * @param blk_size Block size in bytes.
1001     * @return Whether packet matches description.
1002     */
1003    bool matchBlockAddr(const PacketPtr pkt, const int blk_size) const;
1004
1005    /**
1006     * Check if packet corresponds to a given address and address space.
1007     *
1008     * @param addr The address to compare against.
1009     * @param is_secure Whether addr belongs to the secure address space.
1010     * @return Whether packet matches description.
1011     */
1012    bool matchAddr(const Addr addr, const bool is_secure) const;
1013
1014    /**
1015     * Check if this packet refers to the same address and address space as
1016     * another packet.
1017     *
1018     * @param pkt The packet to compare against.
1019     * @return Whether packet matches description.
1020     */
1021    bool matchAddr(const PacketPtr pkt) const;
1022
1023  public:
1024    /**
1025     * @{
1026     * @name Data accessor mehtods
1027     */
1028
1029    /**
1030     * Set the data pointer to the following value that should not be
1031     * freed. Static data allows us to do a single memcpy even if
1032     * multiple packets are required to get from source to destination
1033     * and back. In essence the pointer is set calling dataStatic on
1034     * the original packet, and whenever this packet is copied and
1035     * forwarded the same pointer is passed on. When a packet
1036     * eventually reaches the destination holding the data, it is
1037     * copied once into the location originally set. On the way back
1038     * to the source, no copies are necessary.
1039     */
1040    template <typename T>
1041    void
1042    dataStatic(T *p)
1043    {
1044        assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1045        data = (PacketDataPtr)p;
1046        flags.set(STATIC_DATA);
1047    }
1048
1049    /**
1050     * Set the data pointer to the following value that should not be
1051     * freed. This version of the function allows the pointer passed
1052     * to us to be const. To avoid issues down the line we cast the
1053     * constness away, the alternative would be to keep both a const
1054     * and non-const data pointer and cleverly choose between
1055     * them. Note that this is only allowed for static data.
1056     */
1057    template <typename T>
1058    void
1059    dataStaticConst(const T *p)
1060    {
1061        assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1062        data = const_cast<PacketDataPtr>(p);
1063        flags.set(STATIC_DATA);
1064    }
1065
1066    /**
1067     * Set the data pointer to a value that should have delete []
1068     * called on it. Dynamic data is local to this packet, and as the
1069     * packet travels from source to destination, forwarded packets
1070     * will allocate their own data. When a packet reaches the final
1071     * destination it will populate the dynamic data of that specific
1072     * packet, and on the way back towards the source, memcpy will be
1073     * invoked in every step where a new packet was created e.g. in
1074     * the caches. Ultimately when the response reaches the source a
1075     * final memcpy is needed to extract the data from the packet
1076     * before it is deallocated.
1077     */
1078    template <typename T>
1079    void
1080    dataDynamic(T *p)
1081    {
1082        assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1083        data = (PacketDataPtr)p;
1084        flags.set(DYNAMIC_DATA);
1085    }
1086
1087    /**
1088     * get a pointer to the data ptr.
1089     */
1090    template <typename T>
1091    T*
1092    getPtr()
1093    {
1094        assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
1095        assert(!isMaskedWrite());
1096        return (T*)data;
1097    }
1098
1099    template <typename T>
1100    const T*
1101    getConstPtr() const
1102    {
1103        assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
1104        return (const T*)data;
1105    }
1106
1107    /**
1108     * Get the data in the packet byte swapped from big endian to
1109     * host endian.
1110     */
1111    template <typename T>
1112    T getBE() const;
1113
1114    /**
1115     * Get the data in the packet byte swapped from little endian to
1116     * host endian.
1117     */
1118    template <typename T>
1119    T getLE() const;
1120
1121    /**
1122     * Get the data in the packet byte swapped from the specified
1123     * endianness.
1124     */
1125    template <typename T>
1126    T get(ByteOrder endian) const;
1127
1128#if THE_ISA != NULL_ISA
1129    /**
1130     * Get the data in the packet byte swapped from guest to host
1131     * endian.
1132     */
1133    template <typename T>
1134    T get() const
1135        M5_DEPRECATED_MSG("The memory system should be ISA independent.");
1136#endif
1137
1138    /** Set the value in the data pointer to v as big endian. */
1139    template <typename T>
1140    void setBE(T v);
1141
1142    /** Set the value in the data pointer to v as little endian. */
1143    template <typename T>
1144    void setLE(T v);
1145
1146    /**
1147     * Set the value in the data pointer to v using the specified
1148     * endianness.
1149     */
1150    template <typename T>
1151    void set(T v, ByteOrder endian);
1152
1153#if THE_ISA != NULL_ISA
1154    /** Set the value in the data pointer to v as guest endian. */
1155    template <typename T>
1156    void set(T v)
1157        M5_DEPRECATED_MSG("The memory system should be ISA independent.");
1158#endif
1159
1160    /**
1161     * Get the data in the packet byte swapped from the specified
1162     * endianness and zero-extended to 64 bits.
1163     */
1164    uint64_t getUintX(ByteOrder endian) const;
1165
1166    /**
1167     * Set the value in the word w after truncating it to the length
1168     * of the packet and then byteswapping it to the desired
1169     * endianness.
1170     */
1171    void setUintX(uint64_t w, ByteOrder endian);
1172
1173    /**
1174     * Copy data into the packet from the provided pointer.
1175     */
1176    void
1177    setData(const uint8_t *p)
1178    {
1179        // we should never be copying data onto itself, which means we
1180        // must idenfity packets with static data, as they carry the
1181        // same pointer from source to destination and back
1182        assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA));
1183
1184        if (p != getPtr<uint8_t>()) {
1185            // for packet with allocated dynamic data, we copy data from
1186            // one to the other, e.g. a forwarded response to a response
1187            std::memcpy(getPtr<uint8_t>(), p, getSize());
1188        }
1189    }
1190
1191    /**
1192     * Copy data into the packet from the provided block pointer,
1193     * which is aligned to the given block size.
1194     */
1195    void
1196    setDataFromBlock(const uint8_t *blk_data, int blkSize)
1197    {
1198        setData(blk_data + getOffset(blkSize));
1199    }
1200
1201    /**
1202     * Copy data from the packet to the memory at the provided pointer.
1203     * @param p Pointer to which data will be copied.
1204     */
1205    void
1206    writeData(uint8_t *p) const
1207    {
1208        if (!isMaskedWrite()) {
1209            std::memcpy(p, getConstPtr<uint8_t>(), getSize());
1210        } else {
1211            assert(req->getByteEnable().size() == getSize());
1212            // Write only the enabled bytes
1213            const uint8_t *base = getConstPtr<uint8_t>();
1214            for (int i = 0; i < getSize(); i++) {
1215                if (req->getByteEnable()[i]) {
1216                    p[i] = *(base + i);
1217                }
1218                // Disabled bytes stay untouched
1219            }
1220        }
1221    }
1222
1223    /**
1224     * Copy data from the packet to the provided block pointer, which
1225     * is aligned to the given block size.
1226     * @param blk_data Pointer to block to which data will be copied.
1227     * @param blkSize Block size in bytes.
1228     */
1229    void
1230    writeDataToBlock(uint8_t *blk_data, int blkSize) const
1231    {
1232        writeData(blk_data + getOffset(blkSize));
1233    }
1234
1235    /**
1236     * delete the data pointed to in the data pointer. Ok to call to
1237     * matter how data was allocted.
1238     */
1239    void
1240    deleteData()
1241    {
1242        if (flags.isSet(DYNAMIC_DATA))
1243            delete [] data;
1244
1245        flags.clear(STATIC_DATA|DYNAMIC_DATA);
1246        data = NULL;
1247    }
1248
1249    /** Allocate memory for the packet. */
1250    void
1251    allocate()
1252    {
1253        // if either this command or the response command has a data
1254        // payload, actually allocate space
1255        if (hasData() || hasRespData()) {
1256            assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1257            flags.set(DYNAMIC_DATA);
1258            data = new uint8_t[getSize()];
1259        }
1260    }
1261
1262    /** @} */
1263
1264    /** Get the data in the packet without byte swapping. */
1265    template <typename T>
1266    T getRaw() const;
1267
1268    /** Set the value in the data pointer to v without byte swapping. */
1269    template <typename T>
1270    void setRaw(T v);
1271
1272  public:
1273    /**
1274     * Check a functional request against a memory value stored in
1275     * another packet (i.e. an in-transit request or
1276     * response). Returns true if the current packet is a read, and
1277     * the other packet provides the data, which is then copied to the
1278     * current packet. If the current packet is a write, and the other
1279     * packet intersects this one, then we update the data
1280     * accordingly.
1281     */
1282    bool
1283    trySatisfyFunctional(PacketPtr other)
1284    {
1285        if (other->isMaskedWrite()) {
1286            // Do not forward data if overlapping with a masked write
1287            if (_isSecure == other->isSecure() &&
1288                getAddr() <= (other->getAddr() + other->getSize() - 1) &&
1289                other->getAddr() <= (getAddr() + getSize() - 1)) {
1290                warn("Trying to check against a masked write, skipping."
1291                     " (addr: 0x%x, other addr: 0x%x)", getAddr(),
1292                     other->getAddr());
1293            }
1294            return false;
1295        }
1296        // all packets that are carrying a payload should have a valid
1297        // data pointer
1298        return trySatisfyFunctional(other, other->getAddr(), other->isSecure(),
1299                                    other->getSize(),
1300                                    other->hasData() ?
1301                                    other->getPtr<uint8_t>() : NULL);
1302    }
1303
1304    /**
1305     * Does the request need to check for cached copies of the same block
1306     * in the memory hierarchy above.
1307     **/
1308    bool
1309    mustCheckAbove() const
1310    {
1311        return cmd == MemCmd::HardPFReq || isEviction();
1312    }
1313
1314    /**
1315     * Is this packet a clean eviction, including both actual clean
1316     * evict packets, but also clean writebacks.
1317     */
1318    bool
1319    isCleanEviction() const
1320    {
1321        return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean;
1322    }
1323
1324    bool
1325    isMaskedWrite() const
1326    {
1327        return (cmd == MemCmd::WriteReq && !req->getByteEnable().empty());
1328    }
1329
1330    /**
1331     * Check a functional request against a memory value represented
1332     * by a base/size pair and an associated data array. If the
1333     * current packet is a read, it may be satisfied by the memory
1334     * value. If the current packet is a write, it may update the
1335     * memory value.
1336     */
1337    bool
1338    trySatisfyFunctional(Printable *obj, Addr base, bool is_secure, int size,
1339                         uint8_t *_data);
1340
1341    /**
1342     * Push label for PrintReq (safe to call unconditionally).
1343     */
1344    void
1345    pushLabel(const std::string &lbl)
1346    {
1347        if (isPrint())
1348            safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
1349    }
1350
1351    /**
1352     * Pop label for PrintReq (safe to call unconditionally).
1353     */
1354    void
1355    popLabel()
1356    {
1357        if (isPrint())
1358            safe_cast<PrintReqState*>(senderState)->popLabel();
1359    }
1360
1361    void print(std::ostream &o, int verbosity = 0,
1362               const std::string &prefix = "") const;
1363
1364    /**
1365     * A no-args wrapper of print(std::ostream...)
1366     * meant to be invoked from DPRINTFs
1367     * avoiding string overheads in fast mode
1368     * @return string with the request's type and start<->end addresses
1369     */
1370    std::string print() const;
1371};
1372
1373#endif //__MEM_PACKET_HH
1374