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44 * Declaration of the Packet class.
47 #ifndef __MEM_PACKET_HH__
48 #define __MEM_PACKET_HH__
54 #include "base/addr_range.hh"
55 #include "base/cast.hh"
56 #include "base/compiler.hh"
57 #include "base/flags.hh"
58 #include "base/logging.hh"
59 #include "base/printable.hh"
60 #include "base/types.hh"
62 #include "mem/request.hh"
63 #include "sim/core.hh"
66 typedef Packet *PacketPtr;
67 typedef uint8_t* PacketDataPtr;
68 typedef std::list<PacketPtr> PacketList;
69 typedef uint64_t PacketId;
77 * List of all commands associated with a packet.
84 ReadRespWithInvalidate,
90 WriteClean, // writes dirty data below without evicting
99 SCUpgradeReq, // Special "weak" upgrade for StoreCond
101 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent)
102 UpgradeFailResp, // Valid for SCUpgradeReq only
109 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent)
113 // MessageReq and MessageResp are deprecated.
114 MemFenceReq = SwapResp + 3,
115 MemSyncReq, // memory synchronization request (e.g., cache invalidate)
116 MemSyncResp, // memory synchronization response
123 // @TODO these should be classified as responses rather than
124 // requests; coding them as requests initially for backwards
126 InvalidDestError, // packet dest field invalid
127 BadAddressError, // memory address invalid
128 FunctionalReadError, // unable to fulfill functional read
129 FunctionalWriteError, // unable to fulfill functional write
130 // Fake simulator-only commands
131 PrintReq, // Print state matching address
132 FlushReq, //request for a cache flush
133 InvalidateReq, // request for address to be invalidated
135 // hardware transactional memory
144 * List of command attributes.
148 IsRead, //!< Data flows from responder to requester
149 IsWrite, //!< Data flows from requester to responder
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
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
170 * Structure that defines attributes and other data associated
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;
184 /// Array to map Command enum to associated info.
185 static const CommandInfo commandInfo[];
192 testCmdAttrib(MemCmd::Attribute attrib) const
194 return commandInfo[cmd].attributes[attrib] != 0;
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); }
212 * A writeback is an eviction that carries data.
214 bool isWriteback() const { return testCmdAttrib(IsEviction) &&
215 testCmdAttrib(HasData); }
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
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); }
233 responseCommand() const
235 return commandInfo[cmd].response;
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; }
242 MemCmd(Command _cmd) : cmd(_cmd) { }
243 MemCmd(int _cmd) : cmd((Command)_cmd) { }
244 MemCmd() : cmd(InvalidCmd) { }
246 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
247 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
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 requestor to the
254 * ultimate destination and back, possibly being conveyed by several
255 * different Packets along the way.)
257 class Packet : public Printable
260 typedef uint32_t FlagsType;
261 typedef ::Flags<FlagsType> Flags;
266 // Flags to transfer across when copying a packet
267 COPY_FLAGS = 0x000000FF,
269 // Flags that are used to create reponse packets
270 RESPONDER_FLAGS = 0x00000009,
272 // Does this packet have sharers (which means it should not be
273 // considered writable) or not. See setHasSharers below.
274 HAS_SHARERS = 0x00000001,
276 // Special control flags
277 /// Special timing-mode atomic snoop for multi-level coherence.
278 EXPRESS_SNOOP = 0x00000002,
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,
285 // Snoop co-ordination flag to indicate that a cache is
286 // responding to a snoop. See setCacheResponding below.
287 CACHE_RESPONDING = 0x00000008,
289 // The writeback/writeclean should be propagated further
290 // downstream by the receiver
291 WRITE_THROUGH = 0x00000010,
293 // Response co-ordination flag for cache maintenance
295 SATISFIED = 0x00000020,
297 // hardware transactional memory
299 // Indicates that this packet/request has returned from the
300 // cache hierarchy in a failed transaction. The core is
301 // notified like this.
302 FAILS_TRANSACTION = 0x00000040,
304 // Indicates that this packet/request originates in the CPU executing
305 // in transactional mode, i.e. in a transaction.
306 FROM_TRANSACTION = 0x00000080,
308 /// Are the 'addr' and 'size' fields valid?
309 VALID_ADDR = 0x00000100,
310 VALID_SIZE = 0x00000200,
312 /// Is the data pointer set to a value that shouldn't be freed
313 /// when the packet is destroyed?
314 STATIC_DATA = 0x00001000,
315 /// The data pointer points to a value that should be freed when
316 /// the packet is destroyed. The pointer is assumed to be pointing
317 /// to an array, and delete [] is consequently called
318 DYNAMIC_DATA = 0x00002000,
320 /// suppress the error if this packet encounters a functional
322 SUPPRESS_FUNC_ERROR = 0x00008000,
324 // Signal block present to squash prefetch and cache evict packets
325 // through express snoop flag
326 BLOCK_CACHED = 0x00010000
332 typedef MemCmd::Command Command;
334 /// The command field of the packet.
339 /// A pointer to the original request.
344 * A pointer to the data being transferred. It can be different
345 * sizes at each level of the hierarchy so it belongs to the
346 * packet, not request. This may or may not be populated when a
347 * responder receives the packet. If not populated memory should
352 /// The address of the request. This address could be virtual or
353 /// physical, depending on the system configuration.
356 /// True if the request targets the secure memory space.
359 /// The size of the request or transfer.
363 * Track the bytes found that satisfy a functional read.
365 std::vector<bool> bytesValid;
367 // Quality of Service priority value
370 // hardware transactional memory
373 * Holds the return status of the transaction.
374 * The default case will be NO_FAIL, otherwise this will specify the
375 * reason for the transaction's failure in the memory subsystem.
377 HtmCacheFailure htmReturnReason;
380 * A global unique identifier of the transaction.
381 * This is used for correctness/debugging only.
383 uint64_t htmTransactionUid;
388 * The extra delay from seeing the packet until the header is
389 * transmitted. This delay is used to communicate the crossbar
390 * forwarding latency to the neighbouring object (e.g. a cache)
391 * that actually makes the packet wait. As the delay is relative,
392 * a 32-bit unsigned should be sufficient.
394 uint32_t headerDelay;
397 * Keep track of the extra delay incurred by snooping upwards
398 * before sending a request down the memory system. This is used
399 * by the coherent crossbar to account for the additional request
405 * The extra pipelining delay from seeing the packet until the end of
406 * payload is transmitted by the component that provided it (if
407 * any). This includes the header delay. Similar to the header
408 * delay, this is used to make up for the fact that the
409 * crossbar does not make the packet wait. As the delay is
410 * relative, a 32-bit unsigned should be sufficient.
412 uint32_t payloadDelay;
415 * A virtual base opaque structure used to hold state associated
416 * with the packet (e.g., an MSHR), specific to a SimObject that
417 * sees the packet. A pointer to this state is returned in the
418 * packet's response so that the SimObject in question can quickly
419 * look up the state needed to process it. A specific subclass
420 * would be derived from this to carry state specific to a
421 * particular sending device.
423 * As multiple SimObjects may add their SenderState throughout the
424 * memory system, the SenderStates create a stack, where a
425 * SimObject can add a new Senderstate, as long as the
426 * predecessing SenderState is restored when the response comes
427 * back. For this reason, the predecessor should always be
428 * populated with the current SenderState of a packet before
429 * modifying the senderState field in the request packet.
433 SenderState* predecessor;
434 SenderState() : predecessor(NULL) {}
435 virtual ~SenderState() {}
439 * Object used to maintain state of a PrintReq. The senderState
440 * field of a PrintReq should always be of this type.
442 class PrintReqState : public SenderState
446 * An entry in the label stack.
448 struct LabelStackEntry
450 const std::string label;
453 LabelStackEntry(const std::string &_label, std::string *_prefix);
456 typedef std::list<LabelStackEntry> LabelStack;
457 LabelStack labelStack;
459 std::string *curPrefixPtr;
465 PrintReqState(std::ostream &os, int verbosity = 0);
469 * Returns the current line prefix.
471 const std::string &curPrefix() { return *curPrefixPtr; }
474 * Push a label onto the label stack, and prepend the given
475 * prefix string onto the current prefix. Labels will only be
476 * printed if an object within the label's scope is printed.
478 void pushLabel(const std::string &lbl,
479 const std::string &prefix = " ");
482 * Pop a label off the label stack.
487 * Print all of the pending unprinted labels on the
488 * stack. Called by printObj(), so normally not called by
489 * users unless bypassing printObj().
494 * Print a Printable object to os, because it matched the
495 * address on a PrintReq.
497 void printObj(Printable *obj);
501 * This packet's sender state. Devices should use dynamic_cast<>
502 * to cast to the state appropriate to the sender. The intent of
503 * this variable is to allow a device to attach extra information
504 * to a request. A response packet must return the sender state
505 * that was attached to the original request (even if a new packet
508 SenderState *senderState;
511 * Push a new sender state to the packet and make the current
512 * sender state the predecessor of the new one. This should be
513 * prefered over direct manipulation of the senderState member
516 * @param sender_state SenderState to push at the top of the stack
518 void pushSenderState(SenderState *sender_state);
521 * Pop the top of the state stack and return a pointer to it. This
522 * assumes the current sender state is not NULL. This should be
523 * preferred over direct manipulation of the senderState member
526 * @return The current top of the stack
528 SenderState *popSenderState();
531 * Go through the sender state stack and return the first instance
532 * that is of type T (as determined by a dynamic_cast). If there
533 * is no sender state of type T, NULL is returned.
535 * @return The topmost state of type T
537 template <typename T>
538 T * findNextSenderState() const
541 SenderState* sender_state = senderState;
542 while (t == NULL && sender_state != NULL) {
543 t = dynamic_cast<T*>(sender_state);
544 sender_state = sender_state->predecessor;
549 /// Return the string name of the cmd field (for debugging and
551 const std::string &cmdString() const { return cmd.toString(); }
553 /// Return the index of this command.
554 inline int cmdToIndex() const { return cmd.toInt(); }
556 bool isRead() const { return cmd.isRead(); }
557 bool isWrite() const { return cmd.isWrite(); }
558 bool isUpgrade() const { return cmd.isUpgrade(); }
559 bool isRequest() const { return cmd.isRequest(); }
560 bool isResponse() const { return cmd.isResponse(); }
561 bool needsWritable() const
563 // we should never check if a response needsWritable, the
564 // request has this flag, and for a response we should rather
565 // look at the hasSharers flag (if not set, the response is to
566 // be considered writable)
568 return cmd.needsWritable();
570 bool needsResponse() const { return cmd.needsResponse(); }
571 bool isInvalidate() const { return cmd.isInvalidate(); }
572 bool isEviction() const { return cmd.isEviction(); }
573 bool isClean() const { return cmd.isClean(); }
574 bool fromCache() const { return cmd.fromCache(); }
575 bool isWriteback() const { return cmd.isWriteback(); }
576 bool hasData() const { return cmd.hasData(); }
577 bool hasRespData() const
579 MemCmd resp_cmd = cmd.responseCommand();
580 return resp_cmd.hasData();
582 bool isLLSC() const { return cmd.isLLSC(); }
583 bool isError() const { return cmd.isError(); }
584 bool isPrint() const { return cmd.isPrint(); }
585 bool isFlush() const { return cmd.isFlush(); }
587 bool isWholeLineWrite(unsigned blk_size)
589 return (cmd == MemCmd::WriteReq || cmd == MemCmd::WriteLineReq) &&
590 getOffset(blk_size) == 0 && getSize() == blk_size;
596 * Set the cacheResponding flag. This is used by the caches to
597 * signal another cache that they are responding to a request. A
598 * cache will only respond to snoops if it has the line in either
599 * Modified or Owned state. Note that on snoop hits we always pass
600 * the line as Modified and never Owned. In the case of an Owned
601 * line we proceed to invalidate all other copies.
603 * On a cache fill (see Cache::handleFill), we check hasSharers
604 * first, ignoring the cacheResponding flag if hasSharers is set.
605 * A line is consequently allocated as:
607 * hasSharers cacheResponding state
610 * false false Exclusive
611 * false true Modified
613 void setCacheResponding()
616 assert(!flags.isSet(CACHE_RESPONDING));
617 flags.set(CACHE_RESPONDING);
619 bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); }
621 * On fills, the hasSharers flag is used by the caches in
622 * combination with the cacheResponding flag, as clarified
623 * above. If the hasSharers flag is not set, the packet is passing
624 * writable. Thus, a response from a memory passes the line as
625 * writable by default.
627 * The hasSharers flag is also used by upstream caches to inform a
628 * downstream cache that they have the block (by calling
629 * setHasSharers on snoop request packets that hit in upstream
630 * cachs tags or MSHRs). If the snoop packet has sharers, a
631 * downstream cache is prevented from passing a dirty line upwards
632 * if it was not explicitly asked for a writable copy. See
633 * Cache::satisfyCpuSideRequest.
635 * The hasSharers flag is also used on writebacks, in
636 * combination with the WritbackClean or WritebackDirty commands,
637 * to allocate the block downstream either as:
639 * command hasSharers state
640 * WritebackDirty false Modified
641 * WritebackDirty true Owned
642 * WritebackClean false Exclusive
643 * WritebackClean true Shared
645 void setHasSharers() { flags.set(HAS_SHARERS); }
646 bool hasSharers() const { return flags.isSet(HAS_SHARERS); }
650 * The express snoop flag is used for two purposes. Firstly, it is
651 * used to bypass flow control for normal (non-snoop) requests
652 * going downstream in the memory system. In cases where a cache
653 * is responding to a snoop from another cache (it had a dirty
654 * line), but the line is not writable (and there are possibly
655 * other copies), the express snoop flag is set by the downstream
656 * cache to invalidate all other copies in zero time. Secondly,
657 * the express snoop flag is also set to be able to distinguish
658 * snoop packets that came from a downstream cache, rather than
659 * snoop packets from neighbouring caches.
661 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); }
662 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); }
665 * On responding to a snoop request (which only happens for
666 * Modified or Owned lines), make sure that we can transform an
667 * Owned response to a Modified one. If this flag is not set, the
668 * responding cache had the line in the Owned state, and there are
669 * possibly other Shared copies in the memory system. A downstream
670 * cache helps in orchestrating the invalidation of these copies
671 * by sending out the appropriate express snoops.
673 void setResponderHadWritable()
675 assert(cacheResponding());
676 assert(!responderHadWritable());
677 flags.set(RESPONDER_HAD_WRITABLE);
679 bool responderHadWritable() const
680 { return flags.isSet(RESPONDER_HAD_WRITABLE); }
683 * Copy the reponse flags from an input packet to this packet. The
684 * reponse flags determine whether a responder has been found and
685 * the state at which the block will be at the destination.
687 * @pkt The packet that we will copy flags from
689 void copyResponderFlags(const PacketPtr pkt);
692 * A writeback/writeclean cmd gets propagated further downstream
693 * by the receiver when the flag is set.
695 void setWriteThrough()
697 assert(cmd.isWrite() &&
698 (cmd.isEviction() || cmd == MemCmd::WriteClean));
699 flags.set(WRITE_THROUGH);
701 void clearWriteThrough() { flags.clear(WRITE_THROUGH); }
702 bool writeThrough() const { return flags.isSet(WRITE_THROUGH); }
705 * Set when a request hits in a cache and the cache is not going
706 * to respond. This is used by the crossbar to coordinate
707 * responses for cache maintenance operations.
711 assert(cmd.isClean());
712 assert(!flags.isSet(SATISFIED));
713 flags.set(SATISFIED);
715 bool satisfied() const { return flags.isSet(SATISFIED); }
717 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); }
718 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); }
719 void setBlockCached() { flags.set(BLOCK_CACHED); }
720 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); }
721 void clearBlockCached() { flags.clear(BLOCK_CACHED); }
725 * Returns 0 if QoS value was never set (constructor default).
727 * @return QoS priority value of the packet
729 inline uint8_t qosValue() const { return _qosValue; }
733 * Interface for setting QoS priority value of the packet.
735 * @param qos_value QoS priority value
737 inline void qosValue(const uint8_t qos_value)
738 { _qosValue = qos_value; }
740 inline RequestorID requestorId() const { return req->requestorId(); }
742 // Network error conditions... encapsulate them as methods since
743 // their encoding keeps changing (from result field to command
748 assert(isResponse());
749 cmd = MemCmd::BadAddressError;
752 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
754 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
756 * Update the address of this packet mid-transaction. This is used
757 * by the address mapper to change an already set address to a new
758 * one based on the system configuration. It is intended to remap
759 * an existing address, so it asserts that the current address is
762 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; }
764 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; }
767 * Get address range to which this packet belongs.
769 * @return Address range of this packet.
771 AddrRange getAddrRange() const;
773 Addr getOffset(unsigned int blk_size) const
775 return getAddr() & Addr(blk_size - 1);
778 Addr getBlockAddr(unsigned int blk_size) const
780 return getAddr() & ~(Addr(blk_size - 1));
783 bool isSecure() const
785 assert(flags.isSet(VALID_ADDR));
790 * Accessor function to atomic op.
792 AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); }
793 bool isAtomicOp() const { return req->isAtomic(); }
796 * It has been determined that the SC packet should successfully update
797 * memory. Therefore, convert this SC packet to a normal write.
804 cmd = MemCmd::WriteReq;
808 * When ruby is in use, Ruby will monitor the cache line and the
809 * phys memory should treat LL ops as normal reads.
816 cmd = MemCmd::ReadReq;
820 * Constructor. Note that a Request object must be constructed
821 * first, but the Requests's physical address and size fields need
822 * not be valid. The command must be supplied.
824 Packet(const RequestPtr &_req, MemCmd _cmd)
825 : cmd(_cmd), id((PacketId)_req.get()), req(_req),
826 data(nullptr), addr(0), _isSecure(false), size(0),
828 htmReturnReason(HtmCacheFailure::NO_FAIL),
829 htmTransactionUid(0),
830 headerDelay(0), snoopDelay(0),
831 payloadDelay(0), senderState(NULL)
834 if (req->hasPaddr()) {
835 addr = req->getPaddr();
836 flags.set(VALID_ADDR);
837 _isSecure = req->isSecure();
841 * hardware transactional memory
843 * This is a bit of a hack!
844 * Technically the address of a HTM command is set to zero
845 * but is not valid. The reason that we pretend it's valid is
846 * to void the getAddr() function from failing. It would be
847 * cumbersome to add control flow in many places to check if the
848 * packet represents a HTM command before calling getAddr().
850 if (req->isHTMCmd()) {
851 flags.set(VALID_ADDR);
854 if (req->hasSize()) {
855 size = req->getSize();
856 flags.set(VALID_SIZE);
861 * Alternate constructor if you are trying to create a packet with
862 * a request that is for a whole block, not the address from the
863 * req. this allows for overriding the size/addr of the req.
865 Packet(const RequestPtr &_req, MemCmd _cmd, int _blkSize, PacketId _id = 0)
866 : cmd(_cmd), id(_id ? _id : (PacketId)_req.get()), req(_req),
867 data(nullptr), addr(0), _isSecure(false),
869 htmReturnReason(HtmCacheFailure::NO_FAIL),
870 htmTransactionUid(0),
872 snoopDelay(0), payloadDelay(0), senderState(NULL)
875 if (req->hasPaddr()) {
876 addr = req->getPaddr() & ~(_blkSize - 1);
877 flags.set(VALID_ADDR);
878 _isSecure = req->isSecure();
881 flags.set(VALID_SIZE);
885 * Alternate constructor for copying a packet. Copy all fields
886 * *except* if the original packet's data was dynamic, don't copy
887 * that, as we can't guarantee that the new packet's lifetime is
888 * less than that of the original packet. In this case the new
889 * packet should allocate its own data.
891 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data)
892 : cmd(pkt->cmd), id(pkt->id), req(pkt->req),
894 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size),
895 bytesValid(pkt->bytesValid),
896 _qosValue(pkt->qosValue()),
897 htmReturnReason(HtmCacheFailure::NO_FAIL),
898 htmTransactionUid(0),
899 headerDelay(pkt->headerDelay),
901 payloadDelay(pkt->payloadDelay),
902 senderState(pkt->senderState)
905 flags.set(pkt->flags & COPY_FLAGS);
907 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE));
909 if (pkt->isHtmTransactional())
910 setHtmTransactional(pkt->getHtmTransactionUid());
912 if (pkt->htmTransactionFailedInCache()) {
913 setHtmTransactionFailedInCache(
914 pkt->getHtmTransactionFailedInCacheRC()
918 // should we allocate space for data, or not, the express
919 // snoops do not need to carry any data as they only serve to
920 // co-ordinate state changes
922 // even if asked to allocate data, if the original packet
923 // holds static data, then the sender will not be doing
924 // any memcpy on receiving the response, thus we simply
925 // carry the pointer forward
926 if (pkt->flags.isSet(STATIC_DATA)) {
928 flags.set(STATIC_DATA);
936 * Generate the appropriate read MemCmd based on the Request flags.
939 makeReadCmd(const RequestPtr &req)
941 if (req->isHTMCmd()) {
942 if (req->isHTMAbort())
943 return MemCmd::HTMAbort;
945 return MemCmd::HTMReq;
946 } else if (req->isLLSC())
947 return MemCmd::LoadLockedReq;
948 else if (req->isPrefetchEx())
949 return MemCmd::SoftPFExReq;
950 else if (req->isPrefetch())
951 return MemCmd::SoftPFReq;
953 return MemCmd::ReadReq;
957 * Generate the appropriate write MemCmd based on the Request flags.
960 makeWriteCmd(const RequestPtr &req)
963 return MemCmd::StoreCondReq;
964 else if (req->isSwap() || req->isAtomic())
965 return MemCmd::SwapReq;
966 else if (req->isCacheInvalidate()) {
967 return req->isCacheClean() ? MemCmd::CleanInvalidReq :
968 MemCmd::InvalidateReq;
969 } else if (req->isCacheClean()) {
970 return MemCmd::CleanSharedReq;
972 return MemCmd::WriteReq;
976 * Constructor-like methods that return Packets based on Request objects.
977 * Fine-tune the MemCmd type if it's not a vanilla read or write.
980 createRead(const RequestPtr &req)
982 return new Packet(req, makeReadCmd(req));
986 createWrite(const RequestPtr &req)
988 return new Packet(req, makeWriteCmd(req));
992 * clean up packet variables
1000 * Take a request packet and modify it in place to be suitable for
1001 * returning as a response to that request.
1006 assert(needsResponse());
1007 assert(isRequest());
1008 cmd = cmd.responseCommand();
1010 // responses are never express, even if the snoop that
1011 // triggered them was
1012 flags.clear(EXPRESS_SNOOP);
1016 makeAtomicResponse()
1022 makeTimingResponse()
1028 setFunctionalResponseStatus(bool success)
1032 cmd = MemCmd::FunctionalWriteError;
1034 cmd = MemCmd::FunctionalReadError;
1040 setSize(unsigned size)
1042 assert(!flags.isSet(VALID_SIZE));
1045 flags.set(VALID_SIZE);
1049 * Check if packet corresponds to a given block-aligned address and
1052 * @param addr The address to compare against.
1053 * @param is_secure Whether addr belongs to the secure address space.
1054 * @param blk_size Block size in bytes.
1055 * @return Whether packet matches description.
1057 bool matchBlockAddr(const Addr addr, const bool is_secure,
1058 const int blk_size) const;
1061 * Check if this packet refers to the same block-aligned address and
1062 * address space as another packet.
1064 * @param pkt The packet to compare against.
1065 * @param blk_size Block size in bytes.
1066 * @return Whether packet matches description.
1068 bool matchBlockAddr(const PacketPtr pkt, const int blk_size) const;
1071 * Check if packet corresponds to a given address and address space.
1073 * @param addr The address to compare against.
1074 * @param is_secure Whether addr belongs to the secure address space.
1075 * @return Whether packet matches description.
1077 bool matchAddr(const Addr addr, const bool is_secure) const;
1080 * Check if this packet refers to the same address and address space as
1083 * @param pkt The packet to compare against.
1084 * @return Whether packet matches description.
1086 bool matchAddr(const PacketPtr pkt) const;
1091 * @name Data accessor mehtods
1095 * Set the data pointer to the following value that should not be
1096 * freed. Static data allows us to do a single memcpy even if
1097 * multiple packets are required to get from source to destination
1098 * and back. In essence the pointer is set calling dataStatic on
1099 * the original packet, and whenever this packet is copied and
1100 * forwarded the same pointer is passed on. When a packet
1101 * eventually reaches the destination holding the data, it is
1102 * copied once into the location originally set. On the way back
1103 * to the source, no copies are necessary.
1105 template <typename T>
1109 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1110 data = (PacketDataPtr)p;
1111 flags.set(STATIC_DATA);
1115 * Set the data pointer to the following value that should not be
1116 * freed. This version of the function allows the pointer passed
1117 * to us to be const. To avoid issues down the line we cast the
1118 * constness away, the alternative would be to keep both a const
1119 * and non-const data pointer and cleverly choose between
1120 * them. Note that this is only allowed for static data.
1122 template <typename T>
1124 dataStaticConst(const T *p)
1126 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1127 data = const_cast<PacketDataPtr>(p);
1128 flags.set(STATIC_DATA);
1132 * Set the data pointer to a value that should have delete []
1133 * called on it. Dynamic data is local to this packet, and as the
1134 * packet travels from source to destination, forwarded packets
1135 * will allocate their own data. When a packet reaches the final
1136 * destination it will populate the dynamic data of that specific
1137 * packet, and on the way back towards the source, memcpy will be
1138 * invoked in every step where a new packet was created e.g. in
1139 * the caches. Ultimately when the response reaches the source a
1140 * final memcpy is needed to extract the data from the packet
1141 * before it is deallocated.
1143 template <typename T>
1147 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1148 data = (PacketDataPtr)p;
1149 flags.set(DYNAMIC_DATA);
1153 * get a pointer to the data ptr.
1155 template <typename T>
1159 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
1160 assert(!isMaskedWrite());
1164 template <typename T>
1168 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
1169 return (const T*)data;
1173 * Get the data in the packet byte swapped from big endian to
1176 template <typename T>
1180 * Get the data in the packet byte swapped from little endian to
1183 template <typename T>
1187 * Get the data in the packet byte swapped from the specified
1190 template <typename T>
1191 T get(ByteOrder endian) const;
1193 /** Set the value in the data pointer to v as big endian. */
1194 template <typename T>
1197 /** Set the value in the data pointer to v as little endian. */
1198 template <typename T>
1202 * Set the value in the data pointer to v using the specified
1205 template <typename T>
1206 void set(T v, ByteOrder endian);
1209 * Get the data in the packet byte swapped from the specified
1210 * endianness and zero-extended to 64 bits.
1212 uint64_t getUintX(ByteOrder endian) const;
1215 * Set the value in the word w after truncating it to the length
1216 * of the packet and then byteswapping it to the desired
1219 void setUintX(uint64_t w, ByteOrder endian);
1222 * Copy data into the packet from the provided pointer.
1225 setData(const uint8_t *p)
1227 // we should never be copying data onto itself, which means we
1228 // must idenfity packets with static data, as they carry the
1229 // same pointer from source to destination and back
1230 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA));
1232 if (p != getPtr<uint8_t>()) {
1233 // for packet with allocated dynamic data, we copy data from
1234 // one to the other, e.g. a forwarded response to a response
1235 std::memcpy(getPtr<uint8_t>(), p, getSize());
1240 * Copy data into the packet from the provided block pointer,
1241 * which is aligned to the given block size.
1244 setDataFromBlock(const uint8_t *blk_data, int blkSize)
1246 setData(blk_data + getOffset(blkSize));
1250 * Copy data from the packet to the memory at the provided pointer.
1251 * @param p Pointer to which data will be copied.
1254 writeData(uint8_t *p) const
1256 if (!isMaskedWrite()) {
1257 std::memcpy(p, getConstPtr<uint8_t>(), getSize());
1259 assert(req->getByteEnable().size() == getSize());
1260 // Write only the enabled bytes
1261 const uint8_t *base = getConstPtr<uint8_t>();
1262 for (int i = 0; i < getSize(); i++) {
1263 if (req->getByteEnable()[i]) {
1266 // Disabled bytes stay untouched
1272 * Copy data from the packet to the provided block pointer, which
1273 * is aligned to the given block size.
1274 * @param blk_data Pointer to block to which data will be copied.
1275 * @param blkSize Block size in bytes.
1278 writeDataToBlock(uint8_t *blk_data, int blkSize) const
1280 writeData(blk_data + getOffset(blkSize));
1284 * delete the data pointed to in the data pointer. Ok to call to
1285 * matter how data was allocted.
1290 if (flags.isSet(DYNAMIC_DATA))
1293 flags.clear(STATIC_DATA|DYNAMIC_DATA);
1297 /** Allocate memory for the packet. */
1301 // if either this command or the response command has a data
1302 // payload, actually allocate space
1303 if (hasData() || hasRespData()) {
1304 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1305 flags.set(DYNAMIC_DATA);
1306 data = new uint8_t[getSize()];
1312 /** Get the data in the packet without byte swapping. */
1313 template <typename T>
1316 /** Set the value in the data pointer to v without byte swapping. */
1317 template <typename T>
1322 * Check a functional request against a memory value stored in
1323 * another packet (i.e. an in-transit request or
1324 * response). Returns true if the current packet is a read, and
1325 * the other packet provides the data, which is then copied to the
1326 * current packet. If the current packet is a write, and the other
1327 * packet intersects this one, then we update the data
1331 trySatisfyFunctional(PacketPtr other)
1333 if (other->isMaskedWrite()) {
1334 // Do not forward data if overlapping with a masked write
1335 if (_isSecure == other->isSecure() &&
1336 getAddr() <= (other->getAddr() + other->getSize() - 1) &&
1337 other->getAddr() <= (getAddr() + getSize() - 1)) {
1338 warn("Trying to check against a masked write, skipping."
1339 " (addr: 0x%x, other addr: 0x%x)", getAddr(),
1344 // all packets that are carrying a payload should have a valid
1346 return trySatisfyFunctional(other, other->getAddr(), other->isSecure(),
1349 other->getPtr<uint8_t>() : NULL);
1353 * Does the request need to check for cached copies of the same block
1354 * in the memory hierarchy above.
1357 mustCheckAbove() const
1359 return cmd == MemCmd::HardPFReq || isEviction();
1363 * Is this packet a clean eviction, including both actual clean
1364 * evict packets, but also clean writebacks.
1367 isCleanEviction() const
1369 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean;
1373 isMaskedWrite() const
1375 return (cmd == MemCmd::WriteReq && req->isMasked());
1379 * Check a functional request against a memory value represented
1380 * by a base/size pair and an associated data array. If the
1381 * current packet is a read, it may be satisfied by the memory
1382 * value. If the current packet is a write, it may update the
1386 trySatisfyFunctional(Printable *obj, Addr base, bool is_secure, int size,
1390 * Push label for PrintReq (safe to call unconditionally).
1393 pushLabel(const std::string &lbl)
1396 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
1400 * Pop label for PrintReq (safe to call unconditionally).
1406 safe_cast<PrintReqState*>(senderState)->popLabel();
1409 void print(std::ostream &o, int verbosity = 0,
1410 const std::string &prefix = "") const;
1413 * A no-args wrapper of print(std::ostream...)
1414 * meant to be invoked from DPRINTFs
1415 * avoiding string overheads in fast mode
1416 * @return string with the request's type and start<->end addresses
1418 std::string print() const;
1420 // hardware transactional memory
1423 * Communicates to the core that a packet was processed by the memory
1424 * subsystem while running in transactional mode.
1425 * It may happen that the transaction has failed at the memory subsystem
1426 * and this needs to be communicated to the core somehow.
1427 * This function decorates the response packet with flags to indicate
1428 * such a situation has occurred.
1430 void makeHtmTransactionalReqResponse(const HtmCacheFailure ret_code);
1433 * Stipulates that this packet/request originates in the CPU executing
1434 * in transactional mode, i.e. within a transaction.
1436 void setHtmTransactional(uint64_t val);
1439 * Returns whether or not this packet/request originates in the CPU
1440 * executing in transactional mode, i.e. within a transaction.
1442 bool isHtmTransactional() const;
1445 * If a packet/request originates in a CPU executing in transactional
1446 * mode, i.e. within a transaction, this function returns the unique ID
1447 * of the transaction. This is used for verifying correctness
1450 uint64_t getHtmTransactionUid() const;
1453 * Stipulates that this packet/request has returned from the
1454 * cache hierarchy in a failed transaction. The core is
1455 * notified like this.
1457 void setHtmTransactionFailedInCache(const HtmCacheFailure ret_code);
1460 * Returns whether or not this packet/request has returned from the
1461 * cache hierarchy in a failed transaction. The core is
1462 * notified liked this.
1464 bool htmTransactionFailedInCache() const;
1467 * If a packet/request has returned from the cache hierarchy in a
1468 * failed transaction, this function returns the failure reason.
1470 HtmCacheFailure getHtmTransactionFailedInCacheRC() const;
1473 #endif //__MEM_PACKET_HH