63#include "base/printable.hh"
64#include "base/types.hh"
65#include "mem/request.hh"
66#include "sim/core.hh"
67
68class Packet;
69typedef Packet *PacketPtr;
70typedef uint8_t* PacketDataPtr;
71typedef std::list<PacketPtr> PacketList;
72
73class MemCmd
74{
75 friend class Packet;
76
77 public:
78 /**
79 * List of all commands associated with a packet.
80 */
81 enum Command
82 {
83 InvalidCmd,
84 ReadReq,
85 ReadResp,
86 ReadRespWithInvalidate,
87 WriteReq,
88 WriteResp,
89 WritebackDirty,
90 WritebackClean,
91 CleanEvict,
92 SoftPFReq,
93 HardPFReq,
94 SoftPFResp,
95 HardPFResp,
96 WriteLineReq,
97 UpgradeReq,
98 SCUpgradeReq, // Special "weak" upgrade for StoreCond
99 UpgradeResp,
100 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent)
101 UpgradeFailResp, // Valid for SCUpgradeReq only
102 ReadExReq,
103 ReadExResp,
104 ReadCleanReq,
105 ReadSharedReq,
106 LoadLockedReq,
107 StoreCondReq,
108 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent)
109 StoreCondResp,
110 SwapReq,
111 SwapResp,
112 MessageReq,
113 MessageResp,
114 MemFenceReq,
115 MemFenceResp,
116 // Error responses
117 // @TODO these should be classified as responses rather than
118 // requests; coding them as requests initially for backwards
119 // compatibility
120 InvalidDestError, // packet dest field invalid
121 BadAddressError, // memory address invalid
122 FunctionalReadError, // unable to fulfill functional read
123 FunctionalWriteError, // unable to fulfill functional write
124 // Fake simulator-only commands
125 PrintReq, // Print state matching address
126 FlushReq, //request for a cache flush
127 InvalidateReq, // request for address to be invalidated
128 InvalidateResp,
129 NUM_MEM_CMDS
130 };
131
132 private:
133 /**
134 * List of command attributes.
135 */
136 enum Attribute
137 {
138 IsRead, //!< Data flows from responder to requester
139 IsWrite, //!< Data flows from requester to responder
140 IsUpgrade,
141 IsInvalidate,
142 NeedsWritable, //!< Requires writable copy to complete in-cache
143 IsRequest, //!< Issued by requester
144 IsResponse, //!< Issue by responder
145 NeedsResponse, //!< Requester needs response from target
146 IsEviction,
147 IsSWPrefetch,
148 IsHWPrefetch,
149 IsLlsc, //!< Alpha/MIPS LL or SC access
150 HasData, //!< There is an associated payload
151 IsError, //!< Error response
152 IsPrint, //!< Print state matching address (for debugging)
153 IsFlush, //!< Flush the address from caches
154 FromCache, //!< Request originated from a caching agent
155 NUM_COMMAND_ATTRIBUTES
156 };
157
158 /**
159 * Structure that defines attributes and other data associated
160 * with a Command.
161 */
162 struct CommandInfo
163 {
164 /// Set of attribute flags.
165 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
166 /// Corresponding response for requests; InvalidCmd if no
167 /// response is applicable.
168 const Command response;
169 /// String representation (for printing)
170 const std::string str;
171 };
172
173 /// Array to map Command enum to associated info.
174 static const CommandInfo commandInfo[];
175
176 private:
177
178 Command cmd;
179
180 bool
181 testCmdAttrib(MemCmd::Attribute attrib) const
182 {
183 return commandInfo[cmd].attributes[attrib] != 0;
184 }
185
186 public:
187
188 bool isRead() const { return testCmdAttrib(IsRead); }
189 bool isWrite() const { return testCmdAttrib(IsWrite); }
190 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); }
191 bool isRequest() const { return testCmdAttrib(IsRequest); }
192 bool isResponse() const { return testCmdAttrib(IsResponse); }
193 bool needsWritable() const { return testCmdAttrib(NeedsWritable); }
194 bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
195 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
196 bool isEviction() const { return testCmdAttrib(IsEviction); }
197 bool fromCache() const { return testCmdAttrib(FromCache); }
198
199 /**
200 * A writeback is an eviction that carries data.
201 */
202 bool isWriteback() const { return testCmdAttrib(IsEviction) &&
203 testCmdAttrib(HasData); }
204
205 /**
206 * Check if this particular packet type carries payload data. Note
207 * that this does not reflect if the data pointer of the packet is
208 * valid or not.
209 */
210 bool hasData() const { return testCmdAttrib(HasData); }
211 bool isLLSC() const { return testCmdAttrib(IsLlsc); }
212 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); }
213 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); }
214 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) ||
215 testCmdAttrib(IsHWPrefetch); }
216 bool isError() const { return testCmdAttrib(IsError); }
217 bool isPrint() const { return testCmdAttrib(IsPrint); }
218 bool isFlush() const { return testCmdAttrib(IsFlush); }
219
220 Command
221 responseCommand() const
222 {
223 return commandInfo[cmd].response;
224 }
225
226 /// Return the string to a cmd given by idx.
227 const std::string &toString() const { return commandInfo[cmd].str; }
228 int toInt() const { return (int)cmd; }
229
230 MemCmd(Command _cmd) : cmd(_cmd) { }
231 MemCmd(int _cmd) : cmd((Command)_cmd) { }
232 MemCmd() : cmd(InvalidCmd) { }
233
234 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
235 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
236};
237
238/**
239 * A Packet is used to encapsulate a transfer between two objects in
240 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
241 * single Request travels all the way from the requester to the
242 * ultimate destination and back, possibly being conveyed by several
243 * different Packets along the way.)
244 */
245class Packet : public Printable
246{
247 public:
248 typedef uint32_t FlagsType;
249 typedef ::Flags<FlagsType> Flags;
250
251 private:
252
253 enum : FlagsType {
254 // Flags to transfer across when copying a packet
255 COPY_FLAGS = 0x0000000F,
256
257 // Does this packet have sharers (which means it should not be
258 // considered writable) or not. See setHasSharers below.
259 HAS_SHARERS = 0x00000001,
260
261 // Special control flags
262 /// Special timing-mode atomic snoop for multi-level coherence.
263 EXPRESS_SNOOP = 0x00000002,
264
265 /// Allow a responding cache to inform the cache hierarchy
266 /// that it had a writable copy before responding. See
267 /// setResponderHadWritable below.
268 RESPONDER_HAD_WRITABLE = 0x00000004,
269
270 // Snoop co-ordination flag to indicate that a cache is
271 // responding to a snoop. See setCacheResponding below.
272 CACHE_RESPONDING = 0x00000008,
273
274 /// Are the 'addr' and 'size' fields valid?
275 VALID_ADDR = 0x00000100,
276 VALID_SIZE = 0x00000200,
277
278 /// Is the data pointer set to a value that shouldn't be freed
279 /// when the packet is destroyed?
280 STATIC_DATA = 0x00001000,
281 /// The data pointer points to a value that should be freed when
282 /// the packet is destroyed. The pointer is assumed to be pointing
283 /// to an array, and delete [] is consequently called
284 DYNAMIC_DATA = 0x00002000,
285
286 /// suppress the error if this packet encounters a functional
287 /// access failure.
288 SUPPRESS_FUNC_ERROR = 0x00008000,
289
290 // Signal block present to squash prefetch and cache evict packets
291 // through express snoop flag
292 BLOCK_CACHED = 0x00010000
293 };
294
295 Flags flags;
296
297 public:
298 typedef MemCmd::Command Command;
299
300 /// The command field of the packet.
301 MemCmd cmd;
302
303 /// A pointer to the original request.
304 const RequestPtr req;
305
306 private:
307 /**
308 * A pointer to the data being transfered. It can be differnt
309 * sizes at each level of the heirarchy so it belongs in the
310 * packet, not request. This may or may not be populated when a
311 * responder recieves the packet. If not populated it memory should
312 * be allocated.
313 */
314 PacketDataPtr data;
315
316 /// The address of the request. This address could be virtual or
317 /// physical, depending on the system configuration.
318 Addr addr;
319
320 /// True if the request targets the secure memory space.
321 bool _isSecure;
322
323 /// The size of the request or transfer.
324 unsigned size;
325
326 /**
327 * Track the bytes found that satisfy a functional read.
328 */
329 std::vector<bool> bytesValid;
330
331 public:
332
333 /**
334 * The extra delay from seeing the packet until the header is
335 * transmitted. This delay is used to communicate the crossbar
336 * forwarding latency to the neighbouring object (e.g. a cache)
337 * that actually makes the packet wait. As the delay is relative,
338 * a 32-bit unsigned should be sufficient.
339 */
340 uint32_t headerDelay;
341
342 /**
343 * Keep track of the extra delay incurred by snooping upwards
344 * before sending a request down the memory system. This is used
345 * by the coherent crossbar to account for the additional request
346 * delay.
347 */
348 uint32_t snoopDelay;
349
350 /**
351 * The extra pipelining delay from seeing the packet until the end of
352 * payload is transmitted by the component that provided it (if
353 * any). This includes the header delay. Similar to the header
354 * delay, this is used to make up for the fact that the
355 * crossbar does not make the packet wait. As the delay is
356 * relative, a 32-bit unsigned should be sufficient.
357 */
358 uint32_t payloadDelay;
359
360 /**
361 * A virtual base opaque structure used to hold state associated
362 * with the packet (e.g., an MSHR), specific to a MemObject that
363 * sees the packet. A pointer to this state is returned in the
364 * packet's response so that the MemObject in question can quickly
365 * look up the state needed to process it. A specific subclass
366 * would be derived from this to carry state specific to a
367 * particular sending device.
368 *
369 * As multiple MemObjects may add their SenderState throughout the
370 * memory system, the SenderStates create a stack, where a
371 * MemObject can add a new Senderstate, as long as the
372 * predecessing SenderState is restored when the response comes
373 * back. For this reason, the predecessor should always be
374 * populated with the current SenderState of a packet before
375 * modifying the senderState field in the request packet.
376 */
377 struct SenderState
378 {
379 SenderState* predecessor;
380 SenderState() : predecessor(NULL) {}
381 virtual ~SenderState() {}
382 };
383
384 /**
385 * Object used to maintain state of a PrintReq. The senderState
386 * field of a PrintReq should always be of this type.
387 */
388 class PrintReqState : public SenderState
389 {
390 private:
391 /**
392 * An entry in the label stack.
393 */
394 struct LabelStackEntry
395 {
396 const std::string label;
397 std::string *prefix;
398 bool labelPrinted;
399 LabelStackEntry(const std::string &_label, std::string *_prefix);
400 };
401
402 typedef std::list<LabelStackEntry> LabelStack;
403 LabelStack labelStack;
404
405 std::string *curPrefixPtr;
406
407 public:
408 std::ostream &os;
409 const int verbosity;
410
411 PrintReqState(std::ostream &os, int verbosity = 0);
412 ~PrintReqState();
413
414 /**
415 * Returns the current line prefix.
416 */
417 const std::string &curPrefix() { return *curPrefixPtr; }
418
419 /**
420 * Push a label onto the label stack, and prepend the given
421 * prefix string onto the current prefix. Labels will only be
422 * printed if an object within the label's scope is printed.
423 */
424 void pushLabel(const std::string &lbl,
425 const std::string &prefix = " ");
426
427 /**
428 * Pop a label off the label stack.
429 */
430 void popLabel();
431
432 /**
433 * Print all of the pending unprinted labels on the
434 * stack. Called by printObj(), so normally not called by
435 * users unless bypassing printObj().
436 */
437 void printLabels();
438
439 /**
440 * Print a Printable object to os, because it matched the
441 * address on a PrintReq.
442 */
443 void printObj(Printable *obj);
444 };
445
446 /**
447 * This packet's sender state. Devices should use dynamic_cast<>
448 * to cast to the state appropriate to the sender. The intent of
449 * this variable is to allow a device to attach extra information
450 * to a request. A response packet must return the sender state
451 * that was attached to the original request (even if a new packet
452 * is created).
453 */
454 SenderState *senderState;
455
456 /**
457 * Push a new sender state to the packet and make the current
458 * sender state the predecessor of the new one. This should be
459 * prefered over direct manipulation of the senderState member
460 * variable.
461 *
462 * @param sender_state SenderState to push at the top of the stack
463 */
464 void pushSenderState(SenderState *sender_state);
465
466 /**
467 * Pop the top of the state stack and return a pointer to it. This
468 * assumes the current sender state is not NULL. This should be
469 * preferred over direct manipulation of the senderState member
470 * variable.
471 *
472 * @return The current top of the stack
473 */
474 SenderState *popSenderState();
475
476 /**
477 * Go through the sender state stack and return the first instance
478 * that is of type T (as determined by a dynamic_cast). If there
479 * is no sender state of type T, NULL is returned.
480 *
481 * @return The topmost state of type T
482 */
483 template <typename T>
484 T * findNextSenderState() const
485 {
486 T *t = NULL;
487 SenderState* sender_state = senderState;
488 while (t == NULL && sender_state != NULL) {
489 t = dynamic_cast<T*>(sender_state);
490 sender_state = sender_state->predecessor;
491 }
492 return t;
493 }
494
495 /// Return the string name of the cmd field (for debugging and
496 /// tracing).
497 const std::string &cmdString() const { return cmd.toString(); }
498
499 /// Return the index of this command.
500 inline int cmdToIndex() const { return cmd.toInt(); }
501
502 bool isRead() const { return cmd.isRead(); }
503 bool isWrite() const { return cmd.isWrite(); }
504 bool isUpgrade() const { return cmd.isUpgrade(); }
505 bool isRequest() const { return cmd.isRequest(); }
506 bool isResponse() const { return cmd.isResponse(); }
507 bool needsWritable() const
508 {
509 // we should never check if a response needsWritable, the
510 // request has this flag, and for a response we should rather
511 // look at the hasSharers flag (if not set, the response is to
512 // be considered writable)
513 assert(isRequest());
514 return cmd.needsWritable();
515 }
516 bool needsResponse() const { return cmd.needsResponse(); }
517 bool isInvalidate() const { return cmd.isInvalidate(); }
518 bool isEviction() const { return cmd.isEviction(); }
519 bool fromCache() const { return cmd.fromCache(); }
520 bool isWriteback() const { return cmd.isWriteback(); }
521 bool hasData() const { return cmd.hasData(); }
522 bool hasRespData() const
523 {
524 MemCmd resp_cmd = cmd.responseCommand();
525 return resp_cmd.hasData();
526 }
527 bool isLLSC() const { return cmd.isLLSC(); }
528 bool isError() const { return cmd.isError(); }
529 bool isPrint() const { return cmd.isPrint(); }
530 bool isFlush() const { return cmd.isFlush(); }
531
532 //@{
533 /// Snoop flags
534 /**
535 * Set the cacheResponding flag. This is used by the caches to
536 * signal another cache that they are responding to a request. A
537 * cache will only respond to snoops if it has the line in either
538 * Modified or Owned state. Note that on snoop hits we always pass
539 * the line as Modified and never Owned. In the case of an Owned
540 * line we proceed to invalidate all other copies.
541 *
542 * On a cache fill (see Cache::handleFill), we check hasSharers
543 * first, ignoring the cacheResponding flag if hasSharers is set.
544 * A line is consequently allocated as:
545 *
546 * hasSharers cacheResponding state
547 * true false Shared
548 * true true Shared
549 * false false Exclusive
550 * false true Modified
551 */
552 void setCacheResponding()
553 {
554 assert(isRequest());
555 assert(!flags.isSet(CACHE_RESPONDING));
556 flags.set(CACHE_RESPONDING);
557 }
558 bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); }
559 /**
560 * On fills, the hasSharers flag is used by the caches in
561 * combination with the cacheResponding flag, as clarified
562 * above. If the hasSharers flag is not set, the packet is passing
563 * writable. Thus, a response from a memory passes the line as
564 * writable by default.
565 *
566 * The hasSharers flag is also used by upstream caches to inform a
567 * downstream cache that they have the block (by calling
568 * setHasSharers on snoop request packets that hit in upstream
569 * cachs tags or MSHRs). If the snoop packet has sharers, a
570 * downstream cache is prevented from passing a dirty line upwards
571 * if it was not explicitly asked for a writable copy. See
572 * Cache::satisfyCpuSideRequest.
573 *
574 * The hasSharers flag is also used on writebacks, in
575 * combination with the WritbackClean or WritebackDirty commands,
576 * to allocate the block downstream either as:
577 *
578 * command hasSharers state
579 * WritebackDirty false Modified
580 * WritebackDirty true Owned
581 * WritebackClean false Exclusive
582 * WritebackClean true Shared
583 */
584 void setHasSharers() { flags.set(HAS_SHARERS); }
585 bool hasSharers() const { return flags.isSet(HAS_SHARERS); }
586 //@}
587
588 /**
589 * The express snoop flag is used for two purposes. Firstly, it is
590 * used to bypass flow control for normal (non-snoop) requests
591 * going downstream in the memory system. In cases where a cache
592 * is responding to a snoop from another cache (it had a dirty
593 * line), but the line is not writable (and there are possibly
594 * other copies), the express snoop flag is set by the downstream
595 * cache to invalidate all other copies in zero time. Secondly,
596 * the express snoop flag is also set to be able to distinguish
597 * snoop packets that came from a downstream cache, rather than
598 * snoop packets from neighbouring caches.
599 */
600 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); }
601 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); }
602
603 /**
604 * On responding to a snoop request (which only happens for
605 * Modified or Owned lines), make sure that we can transform an
606 * Owned response to a Modified one. If this flag is not set, the
607 * responding cache had the line in the Owned state, and there are
608 * possibly other Shared copies in the memory system. A downstream
609 * cache helps in orchestrating the invalidation of these copies
610 * by sending out the appropriate express snoops.
611 */
612 void setResponderHadWritable()
613 {
614 assert(cacheResponding());
615 assert(!responderHadWritable());
616 flags.set(RESPONDER_HAD_WRITABLE);
617 }
618 bool responderHadWritable() const
619 { return flags.isSet(RESPONDER_HAD_WRITABLE); }
620
621 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); }
622 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); }
623 void setBlockCached() { flags.set(BLOCK_CACHED); }
624 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); }
625 void clearBlockCached() { flags.clear(BLOCK_CACHED); }
626
627 // Network error conditions... encapsulate them as methods since
628 // their encoding keeps changing (from result field to command
629 // field, etc.)
630 void
631 setBadAddress()
632 {
633 assert(isResponse());
634 cmd = MemCmd::BadAddressError;
635 }
636
637 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
638
639 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
640 /**
641 * Update the address of this packet mid-transaction. This is used
642 * by the address mapper to change an already set address to a new
643 * one based on the system configuration. It is intended to remap
644 * an existing address, so it asserts that the current address is
645 * valid.
646 */
647 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; }
648
649 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; }
650
651 Addr getOffset(unsigned int blk_size) const
652 {
653 return getAddr() & Addr(blk_size - 1);
654 }
655
656 Addr getBlockAddr(unsigned int blk_size) const
657 {
658 return getAddr() & ~(Addr(blk_size - 1));
659 }
660
661 bool isSecure() const
662 {
663 assert(flags.isSet(VALID_ADDR));
664 return _isSecure;
665 }
666
667 /**
668 * Accessor function to atomic op.
669 */
670 AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); }
671 bool isAtomicOp() const { return req->isAtomic(); }
672
673 /**
674 * It has been determined that the SC packet should successfully update
675 * memory. Therefore, convert this SC packet to a normal write.
676 */
677 void
678 convertScToWrite()
679 {
680 assert(isLLSC());
681 assert(isWrite());
682 cmd = MemCmd::WriteReq;
683 }
684
685 /**
686 * When ruby is in use, Ruby will monitor the cache line and the
687 * phys memory should treat LL ops as normal reads.
688 */
689 void
690 convertLlToRead()
691 {
692 assert(isLLSC());
693 assert(isRead());
694 cmd = MemCmd::ReadReq;
695 }
696
697 /**
698 * Constructor. Note that a Request object must be constructed
699 * first, but the Requests's physical address and size fields need
700 * not be valid. The command must be supplied.
701 */
702 Packet(const RequestPtr _req, MemCmd _cmd)
703 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false),
704 size(0), headerDelay(0), snoopDelay(0), payloadDelay(0),
705 senderState(NULL)
706 {
707 if (req->hasPaddr()) {
708 addr = req->getPaddr();
709 flags.set(VALID_ADDR);
710 _isSecure = req->isSecure();
711 }
712 if (req->hasSize()) {
713 size = req->getSize();
714 flags.set(VALID_SIZE);
715 }
716 }
717
718 /**
719 * Alternate constructor if you are trying to create a packet with
720 * a request that is for a whole block, not the address from the
721 * req. this allows for overriding the size/addr of the req.
722 */
723 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize)
724 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false),
725 headerDelay(0), snoopDelay(0), payloadDelay(0),
726 senderState(NULL)
727 {
728 if (req->hasPaddr()) {
729 addr = req->getPaddr() & ~(_blkSize - 1);
730 flags.set(VALID_ADDR);
731 _isSecure = req->isSecure();
732 }
733 size = _blkSize;
734 flags.set(VALID_SIZE);
735 }
736
737 /**
738 * Alternate constructor for copying a packet. Copy all fields
739 * *except* if the original packet's data was dynamic, don't copy
740 * that, as we can't guarantee that the new packet's lifetime is
741 * less than that of the original packet. In this case the new
742 * packet should allocate its own data.
743 */
744 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data)
745 : cmd(pkt->cmd), req(pkt->req),
746 data(nullptr),
747 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size),
748 bytesValid(pkt->bytesValid),
749 headerDelay(pkt->headerDelay),
750 snoopDelay(0),
751 payloadDelay(pkt->payloadDelay),
752 senderState(pkt->senderState)
753 {
754 if (!clear_flags)
755 flags.set(pkt->flags & COPY_FLAGS);
756
757 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE));
758
759 // should we allocate space for data, or not, the express
760 // snoops do not need to carry any data as they only serve to
761 // co-ordinate state changes
762 if (alloc_data) {
763 // even if asked to allocate data, if the original packet
764 // holds static data, then the sender will not be doing
765 // any memcpy on receiving the response, thus we simply
766 // carry the pointer forward
767 if (pkt->flags.isSet(STATIC_DATA)) {
768 data = pkt->data;
769 flags.set(STATIC_DATA);
770 } else {
771 allocate();
772 }
773 }
774 }
775
776 /**
777 * Generate the appropriate read MemCmd based on the Request flags.
778 */
779 static MemCmd
780 makeReadCmd(const RequestPtr req)
781 {
782 if (req->isLLSC())
783 return MemCmd::LoadLockedReq;
784 else if (req->isPrefetch())
785 return MemCmd::SoftPFReq;
786 else
787 return MemCmd::ReadReq;
788 }
789
790 /**
791 * Generate the appropriate write MemCmd based on the Request flags.
792 */
793 static MemCmd
794 makeWriteCmd(const RequestPtr req)
795 {
796 if (req->isLLSC())
797 return MemCmd::StoreCondReq;
798 else if (req->isSwap())
799 return MemCmd::SwapReq;
800 else
801 return MemCmd::WriteReq;
802 }
803
804 /**
805 * Constructor-like methods that return Packets based on Request objects.
806 * Fine-tune the MemCmd type if it's not a vanilla read or write.
807 */
808 static PacketPtr
809 createRead(const RequestPtr req)
810 {
811 return new Packet(req, makeReadCmd(req));
812 }
813
814 static PacketPtr
815 createWrite(const RequestPtr req)
816 {
817 return new Packet(req, makeWriteCmd(req));
818 }
819
820 /**
821 * clean up packet variables
822 */
823 ~Packet()
824 {
825 // Delete the request object if this is a request packet which
826 // does not need a response, because the requester will not get
827 // a chance. If the request packet needs a response then the
828 // request will be deleted on receipt of the response
829 // packet. We also make sure to never delete the request for
830 // express snoops, even for cases when responses are not
831 // needed (CleanEvict and Writeback), since the snoop packet
832 // re-uses the same request.
833 if (req && isRequest() && !needsResponse() &&
834 !isExpressSnoop()) {
835 delete req;
836 }
837 deleteData();
838 }
839
840 /**
841 * Take a request packet and modify it in place to be suitable for
842 * returning as a response to that request.
843 */
844 void
845 makeResponse()
846 {
847 assert(needsResponse());
848 assert(isRequest());
849 cmd = cmd.responseCommand();
850
851 // responses are never express, even if the snoop that
852 // triggered them was
853 flags.clear(EXPRESS_SNOOP);
854 }
855
856 void
857 makeAtomicResponse()
858 {
859 makeResponse();
860 }
861
862 void
863 makeTimingResponse()
864 {
865 makeResponse();
866 }
867
868 void
869 setFunctionalResponseStatus(bool success)
870 {
871 if (!success) {
872 if (isWrite()) {
873 cmd = MemCmd::FunctionalWriteError;
874 } else {
875 cmd = MemCmd::FunctionalReadError;
876 }
877 }
878 }
879
880 void
881 setSize(unsigned size)
882 {
883 assert(!flags.isSet(VALID_SIZE));
884
885 this->size = size;
886 flags.set(VALID_SIZE);
887 }
888
889
890 public:
891 /**
892 * @{
893 * @name Data accessor mehtods
894 */
895
896 /**
897 * Set the data pointer to the following value that should not be
898 * freed. Static data allows us to do a single memcpy even if
899 * multiple packets are required to get from source to destination
900 * and back. In essence the pointer is set calling dataStatic on
901 * the original packet, and whenever this packet is copied and
902 * forwarded the same pointer is passed on. When a packet
903 * eventually reaches the destination holding the data, it is
904 * copied once into the location originally set. On the way back
905 * to the source, no copies are necessary.
906 */
907 template <typename T>
908 void
909 dataStatic(T *p)
910 {
911 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
912 data = (PacketDataPtr)p;
913 flags.set(STATIC_DATA);
914 }
915
916 /**
917 * Set the data pointer to the following value that should not be
918 * freed. This version of the function allows the pointer passed
919 * to us to be const. To avoid issues down the line we cast the
920 * constness away, the alternative would be to keep both a const
921 * and non-const data pointer and cleverly choose between
922 * them. Note that this is only allowed for static data.
923 */
924 template <typename T>
925 void
926 dataStaticConst(const T *p)
927 {
928 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
929 data = const_cast<PacketDataPtr>(p);
930 flags.set(STATIC_DATA);
931 }
932
933 /**
934 * Set the data pointer to a value that should have delete []
935 * called on it. Dynamic data is local to this packet, and as the
936 * packet travels from source to destination, forwarded packets
937 * will allocate their own data. When a packet reaches the final
938 * destination it will populate the dynamic data of that specific
939 * packet, and on the way back towards the source, memcpy will be
940 * invoked in every step where a new packet was created e.g. in
941 * the caches. Ultimately when the response reaches the source a
942 * final memcpy is needed to extract the data from the packet
943 * before it is deallocated.
944 */
945 template <typename T>
946 void
947 dataDynamic(T *p)
948 {
949 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
950 data = (PacketDataPtr)p;
951 flags.set(DYNAMIC_DATA);
952 }
953
954 /**
955 * get a pointer to the data ptr.
956 */
957 template <typename T>
958 T*
959 getPtr()
960 {
961 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
962 return (T*)data;
963 }
964
965 template <typename T>
966 const T*
967 getConstPtr() const
968 {
969 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
970 return (const T*)data;
971 }
972
973 /**
974 * Get the data in the packet byte swapped from big endian to
975 * host endian.
976 */
977 template <typename T>
978 T getBE() const;
979
980 /**
981 * Get the data in the packet byte swapped from little endian to
982 * host endian.
983 */
984 template <typename T>
985 T getLE() const;
986
987 /**
988 * Get the data in the packet byte swapped from the specified
989 * endianness.
990 */
991 template <typename T>
992 T get(ByteOrder endian) const;
993
994 /**
995 * Get the data in the packet byte swapped from guest to host
996 * endian.
997 */
998 template <typename T>
999 T get() const;
1000
1001 /** Set the value in the data pointer to v as big endian. */
1002 template <typename T>
1003 void setBE(T v);
1004
1005 /** Set the value in the data pointer to v as little endian. */
1006 template <typename T>
1007 void setLE(T v);
1008
1009 /**
1010 * Set the value in the data pointer to v using the specified
1011 * endianness.
1012 */
1013 template <typename T>
1014 void set(T v, ByteOrder endian);
1015
1016 /** Set the value in the data pointer to v as guest endian. */
1017 template <typename T>
1018 void set(T v);
1019
1020 /**
1021 * Copy data into the packet from the provided pointer.
1022 */
1023 void
1024 setData(const uint8_t *p)
1025 {
1026 // we should never be copying data onto itself, which means we
1027 // must idenfity packets with static data, as they carry the
1028 // same pointer from source to destination and back
1029 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA));
1030
1031 if (p != getPtr<uint8_t>())
1032 // for packet with allocated dynamic data, we copy data from
1033 // one to the other, e.g. a forwarded response to a response
1034 std::memcpy(getPtr<uint8_t>(), p, getSize());
1035 }
1036
1037 /**
1038 * Copy data into the packet from the provided block pointer,
1039 * which is aligned to the given block size.
1040 */
1041 void
1042 setDataFromBlock(const uint8_t *blk_data, int blkSize)
1043 {
1044 setData(blk_data + getOffset(blkSize));
1045 }
1046
1047 /**
1048 * Copy data from the packet to the provided block pointer, which
1049 * is aligned to the given block size.
1050 */
1051 void
1052 writeData(uint8_t *p) const
1053 {
1054 std::memcpy(p, getConstPtr<uint8_t>(), getSize());
1055 }
1056
1057 /**
1058 * Copy data from the packet to the memory at the provided pointer.
1059 */
1060 void
1061 writeDataToBlock(uint8_t *blk_data, int blkSize) const
1062 {
1063 writeData(blk_data + getOffset(blkSize));
1064 }
1065
1066 /**
1067 * delete the data pointed to in the data pointer. Ok to call to
1068 * matter how data was allocted.
1069 */
1070 void
1071 deleteData()
1072 {
1073 if (flags.isSet(DYNAMIC_DATA))
1074 delete [] data;
1075
1076 flags.clear(STATIC_DATA|DYNAMIC_DATA);
1077 data = NULL;
1078 }
1079
1080 /** Allocate memory for the packet. */
1081 void
1082 allocate()
1083 {
1084 // if either this command or the response command has a data
1085 // payload, actually allocate space
1086 if (hasData() || hasRespData()) {
1087 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1088 flags.set(DYNAMIC_DATA);
1089 data = new uint8_t[getSize()];
1090 }
1091 }
1092
1093 /** @} */
1094
1095 private: // Private data accessor methods
1096 /** Get the data in the packet without byte swapping. */
1097 template <typename T>
1098 T getRaw() const;
1099
1100 /** Set the value in the data pointer to v without byte swapping. */
1101 template <typename T>
1102 void setRaw(T v);
1103
1104 public:
1105 /**
1106 * Check a functional request against a memory value stored in
1107 * another packet (i.e. an in-transit request or
1108 * response). Returns true if the current packet is a read, and
1109 * the other packet provides the data, which is then copied to the
1110 * current packet. If the current packet is a write, and the other
1111 * packet intersects this one, then we update the data
1112 * accordingly.
1113 */
1114 bool
1115 checkFunctional(PacketPtr other)
1116 {
1117 // all packets that are carrying a payload should have a valid
1118 // data pointer
1119 return checkFunctional(other, other->getAddr(), other->isSecure(),
1120 other->getSize(),
1121 other->hasData() ?
1122 other->getPtr<uint8_t>() : NULL);
1123 }
1124
1125 /**
1126 * Does the request need to check for cached copies of the same block
1127 * in the memory hierarchy above.
1128 **/
1129 bool
1130 mustCheckAbove() const
1131 {
1132 return cmd == MemCmd::HardPFReq || isEviction();
1133 }
1134
1135 /**
1136 * Is this packet a clean eviction, including both actual clean
1137 * evict packets, but also clean writebacks.
1138 */
1139 bool
1140 isCleanEviction() const
1141 {
1142 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean;
1143 }
1144
1145 /**
1146 * Check a functional request against a memory value represented
1147 * by a base/size pair and an associated data array. If the
1148 * current packet is a read, it may be satisfied by the memory
1149 * value. If the current packet is a write, it may update the
1150 * memory value.
1151 */
1152 bool
1153 checkFunctional(Printable *obj, Addr base, bool is_secure, int size,
1154 uint8_t *_data);
1155
1156 /**
1157 * Push label for PrintReq (safe to call unconditionally).
1158 */
1159 void
1160 pushLabel(const std::string &lbl)
1161 {
1162 if (isPrint())
1163 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
1164 }
1165
1166 /**
1167 * Pop label for PrintReq (safe to call unconditionally).
1168 */
1169 void
1170 popLabel()
1171 {
1172 if (isPrint())
1173 safe_cast<PrintReqState*>(senderState)->popLabel();
1174 }
1175
1176 void print(std::ostream &o, int verbosity = 0,
1177 const std::string &prefix = "") const;
1178
1179 /**
1180 * A no-args wrapper of print(std::ostream...)
1181 * meant to be invoked from DPRINTFs
1182 * avoiding string overheads in fast mode
1183 * @return string with the request's type and start<->end addresses
1184 */
1185 std::string print() const;
1186};
1187
1188#endif //__MEM_PACKET_HH
| 63#include "base/printable.hh"
64#include "base/types.hh"
65#include "mem/request.hh"
66#include "sim/core.hh"
67
68class Packet;
69typedef Packet *PacketPtr;
70typedef uint8_t* PacketDataPtr;
71typedef std::list<PacketPtr> PacketList;
72
73class MemCmd
74{
75 friend class Packet;
76
77 public:
78 /**
79 * List of all commands associated with a packet.
80 */
81 enum Command
82 {
83 InvalidCmd,
84 ReadReq,
85 ReadResp,
86 ReadRespWithInvalidate,
87 WriteReq,
88 WriteResp,
89 WritebackDirty,
90 WritebackClean,
91 CleanEvict,
92 SoftPFReq,
93 HardPFReq,
94 SoftPFResp,
95 HardPFResp,
96 WriteLineReq,
97 UpgradeReq,
98 SCUpgradeReq, // Special "weak" upgrade for StoreCond
99 UpgradeResp,
100 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent)
101 UpgradeFailResp, // Valid for SCUpgradeReq only
102 ReadExReq,
103 ReadExResp,
104 ReadCleanReq,
105 ReadSharedReq,
106 LoadLockedReq,
107 StoreCondReq,
108 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent)
109 StoreCondResp,
110 SwapReq,
111 SwapResp,
112 MessageReq,
113 MessageResp,
114 MemFenceReq,
115 MemFenceResp,
116 // Error responses
117 // @TODO these should be classified as responses rather than
118 // requests; coding them as requests initially for backwards
119 // compatibility
120 InvalidDestError, // packet dest field invalid
121 BadAddressError, // memory address invalid
122 FunctionalReadError, // unable to fulfill functional read
123 FunctionalWriteError, // unable to fulfill functional write
124 // Fake simulator-only commands
125 PrintReq, // Print state matching address
126 FlushReq, //request for a cache flush
127 InvalidateReq, // request for address to be invalidated
128 InvalidateResp,
129 NUM_MEM_CMDS
130 };
131
132 private:
133 /**
134 * List of command attributes.
135 */
136 enum Attribute
137 {
138 IsRead, //!< Data flows from responder to requester
139 IsWrite, //!< Data flows from requester to responder
140 IsUpgrade,
141 IsInvalidate,
142 NeedsWritable, //!< Requires writable copy to complete in-cache
143 IsRequest, //!< Issued by requester
144 IsResponse, //!< Issue by responder
145 NeedsResponse, //!< Requester needs response from target
146 IsEviction,
147 IsSWPrefetch,
148 IsHWPrefetch,
149 IsLlsc, //!< Alpha/MIPS LL or SC access
150 HasData, //!< There is an associated payload
151 IsError, //!< Error response
152 IsPrint, //!< Print state matching address (for debugging)
153 IsFlush, //!< Flush the address from caches
154 FromCache, //!< Request originated from a caching agent
155 NUM_COMMAND_ATTRIBUTES
156 };
157
158 /**
159 * Structure that defines attributes and other data associated
160 * with a Command.
161 */
162 struct CommandInfo
163 {
164 /// Set of attribute flags.
165 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
166 /// Corresponding response for requests; InvalidCmd if no
167 /// response is applicable.
168 const Command response;
169 /// String representation (for printing)
170 const std::string str;
171 };
172
173 /// Array to map Command enum to associated info.
174 static const CommandInfo commandInfo[];
175
176 private:
177
178 Command cmd;
179
180 bool
181 testCmdAttrib(MemCmd::Attribute attrib) const
182 {
183 return commandInfo[cmd].attributes[attrib] != 0;
184 }
185
186 public:
187
188 bool isRead() const { return testCmdAttrib(IsRead); }
189 bool isWrite() const { return testCmdAttrib(IsWrite); }
190 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); }
191 bool isRequest() const { return testCmdAttrib(IsRequest); }
192 bool isResponse() const { return testCmdAttrib(IsResponse); }
193 bool needsWritable() const { return testCmdAttrib(NeedsWritable); }
194 bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
195 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
196 bool isEviction() const { return testCmdAttrib(IsEviction); }
197 bool fromCache() const { return testCmdAttrib(FromCache); }
198
199 /**
200 * A writeback is an eviction that carries data.
201 */
202 bool isWriteback() const { return testCmdAttrib(IsEviction) &&
203 testCmdAttrib(HasData); }
204
205 /**
206 * Check if this particular packet type carries payload data. Note
207 * that this does not reflect if the data pointer of the packet is
208 * valid or not.
209 */
210 bool hasData() const { return testCmdAttrib(HasData); }
211 bool isLLSC() const { return testCmdAttrib(IsLlsc); }
212 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); }
213 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); }
214 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) ||
215 testCmdAttrib(IsHWPrefetch); }
216 bool isError() const { return testCmdAttrib(IsError); }
217 bool isPrint() const { return testCmdAttrib(IsPrint); }
218 bool isFlush() const { return testCmdAttrib(IsFlush); }
219
220 Command
221 responseCommand() const
222 {
223 return commandInfo[cmd].response;
224 }
225
226 /// Return the string to a cmd given by idx.
227 const std::string &toString() const { return commandInfo[cmd].str; }
228 int toInt() const { return (int)cmd; }
229
230 MemCmd(Command _cmd) : cmd(_cmd) { }
231 MemCmd(int _cmd) : cmd((Command)_cmd) { }
232 MemCmd() : cmd(InvalidCmd) { }
233
234 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
235 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
236};
237
238/**
239 * A Packet is used to encapsulate a transfer between two objects in
240 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
241 * single Request travels all the way from the requester to the
242 * ultimate destination and back, possibly being conveyed by several
243 * different Packets along the way.)
244 */
245class Packet : public Printable
246{
247 public:
248 typedef uint32_t FlagsType;
249 typedef ::Flags<FlagsType> Flags;
250
251 private:
252
253 enum : FlagsType {
254 // Flags to transfer across when copying a packet
255 COPY_FLAGS = 0x0000000F,
256
257 // Does this packet have sharers (which means it should not be
258 // considered writable) or not. See setHasSharers below.
259 HAS_SHARERS = 0x00000001,
260
261 // Special control flags
262 /// Special timing-mode atomic snoop for multi-level coherence.
263 EXPRESS_SNOOP = 0x00000002,
264
265 /// Allow a responding cache to inform the cache hierarchy
266 /// that it had a writable copy before responding. See
267 /// setResponderHadWritable below.
268 RESPONDER_HAD_WRITABLE = 0x00000004,
269
270 // Snoop co-ordination flag to indicate that a cache is
271 // responding to a snoop. See setCacheResponding below.
272 CACHE_RESPONDING = 0x00000008,
273
274 /// Are the 'addr' and 'size' fields valid?
275 VALID_ADDR = 0x00000100,
276 VALID_SIZE = 0x00000200,
277
278 /// Is the data pointer set to a value that shouldn't be freed
279 /// when the packet is destroyed?
280 STATIC_DATA = 0x00001000,
281 /// The data pointer points to a value that should be freed when
282 /// the packet is destroyed. The pointer is assumed to be pointing
283 /// to an array, and delete [] is consequently called
284 DYNAMIC_DATA = 0x00002000,
285
286 /// suppress the error if this packet encounters a functional
287 /// access failure.
288 SUPPRESS_FUNC_ERROR = 0x00008000,
289
290 // Signal block present to squash prefetch and cache evict packets
291 // through express snoop flag
292 BLOCK_CACHED = 0x00010000
293 };
294
295 Flags flags;
296
297 public:
298 typedef MemCmd::Command Command;
299
300 /// The command field of the packet.
301 MemCmd cmd;
302
303 /// A pointer to the original request.
304 const RequestPtr req;
305
306 private:
307 /**
308 * A pointer to the data being transfered. It can be differnt
309 * sizes at each level of the heirarchy so it belongs in the
310 * packet, not request. This may or may not be populated when a
311 * responder recieves the packet. If not populated it memory should
312 * be allocated.
313 */
314 PacketDataPtr data;
315
316 /// The address of the request. This address could be virtual or
317 /// physical, depending on the system configuration.
318 Addr addr;
319
320 /// True if the request targets the secure memory space.
321 bool _isSecure;
322
323 /// The size of the request or transfer.
324 unsigned size;
325
326 /**
327 * Track the bytes found that satisfy a functional read.
328 */
329 std::vector<bool> bytesValid;
330
331 public:
332
333 /**
334 * The extra delay from seeing the packet until the header is
335 * transmitted. This delay is used to communicate the crossbar
336 * forwarding latency to the neighbouring object (e.g. a cache)
337 * that actually makes the packet wait. As the delay is relative,
338 * a 32-bit unsigned should be sufficient.
339 */
340 uint32_t headerDelay;
341
342 /**
343 * Keep track of the extra delay incurred by snooping upwards
344 * before sending a request down the memory system. This is used
345 * by the coherent crossbar to account for the additional request
346 * delay.
347 */
348 uint32_t snoopDelay;
349
350 /**
351 * The extra pipelining delay from seeing the packet until the end of
352 * payload is transmitted by the component that provided it (if
353 * any). This includes the header delay. Similar to the header
354 * delay, this is used to make up for the fact that the
355 * crossbar does not make the packet wait. As the delay is
356 * relative, a 32-bit unsigned should be sufficient.
357 */
358 uint32_t payloadDelay;
359
360 /**
361 * A virtual base opaque structure used to hold state associated
362 * with the packet (e.g., an MSHR), specific to a MemObject that
363 * sees the packet. A pointer to this state is returned in the
364 * packet's response so that the MemObject in question can quickly
365 * look up the state needed to process it. A specific subclass
366 * would be derived from this to carry state specific to a
367 * particular sending device.
368 *
369 * As multiple MemObjects may add their SenderState throughout the
370 * memory system, the SenderStates create a stack, where a
371 * MemObject can add a new Senderstate, as long as the
372 * predecessing SenderState is restored when the response comes
373 * back. For this reason, the predecessor should always be
374 * populated with the current SenderState of a packet before
375 * modifying the senderState field in the request packet.
376 */
377 struct SenderState
378 {
379 SenderState* predecessor;
380 SenderState() : predecessor(NULL) {}
381 virtual ~SenderState() {}
382 };
383
384 /**
385 * Object used to maintain state of a PrintReq. The senderState
386 * field of a PrintReq should always be of this type.
387 */
388 class PrintReqState : public SenderState
389 {
390 private:
391 /**
392 * An entry in the label stack.
393 */
394 struct LabelStackEntry
395 {
396 const std::string label;
397 std::string *prefix;
398 bool labelPrinted;
399 LabelStackEntry(const std::string &_label, std::string *_prefix);
400 };
401
402 typedef std::list<LabelStackEntry> LabelStack;
403 LabelStack labelStack;
404
405 std::string *curPrefixPtr;
406
407 public:
408 std::ostream &os;
409 const int verbosity;
410
411 PrintReqState(std::ostream &os, int verbosity = 0);
412 ~PrintReqState();
413
414 /**
415 * Returns the current line prefix.
416 */
417 const std::string &curPrefix() { return *curPrefixPtr; }
418
419 /**
420 * Push a label onto the label stack, and prepend the given
421 * prefix string onto the current prefix. Labels will only be
422 * printed if an object within the label's scope is printed.
423 */
424 void pushLabel(const std::string &lbl,
425 const std::string &prefix = " ");
426
427 /**
428 * Pop a label off the label stack.
429 */
430 void popLabel();
431
432 /**
433 * Print all of the pending unprinted labels on the
434 * stack. Called by printObj(), so normally not called by
435 * users unless bypassing printObj().
436 */
437 void printLabels();
438
439 /**
440 * Print a Printable object to os, because it matched the
441 * address on a PrintReq.
442 */
443 void printObj(Printable *obj);
444 };
445
446 /**
447 * This packet's sender state. Devices should use dynamic_cast<>
448 * to cast to the state appropriate to the sender. The intent of
449 * this variable is to allow a device to attach extra information
450 * to a request. A response packet must return the sender state
451 * that was attached to the original request (even if a new packet
452 * is created).
453 */
454 SenderState *senderState;
455
456 /**
457 * Push a new sender state to the packet and make the current
458 * sender state the predecessor of the new one. This should be
459 * prefered over direct manipulation of the senderState member
460 * variable.
461 *
462 * @param sender_state SenderState to push at the top of the stack
463 */
464 void pushSenderState(SenderState *sender_state);
465
466 /**
467 * Pop the top of the state stack and return a pointer to it. This
468 * assumes the current sender state is not NULL. This should be
469 * preferred over direct manipulation of the senderState member
470 * variable.
471 *
472 * @return The current top of the stack
473 */
474 SenderState *popSenderState();
475
476 /**
477 * Go through the sender state stack and return the first instance
478 * that is of type T (as determined by a dynamic_cast). If there
479 * is no sender state of type T, NULL is returned.
480 *
481 * @return The topmost state of type T
482 */
483 template <typename T>
484 T * findNextSenderState() const
485 {
486 T *t = NULL;
487 SenderState* sender_state = senderState;
488 while (t == NULL && sender_state != NULL) {
489 t = dynamic_cast<T*>(sender_state);
490 sender_state = sender_state->predecessor;
491 }
492 return t;
493 }
494
495 /// Return the string name of the cmd field (for debugging and
496 /// tracing).
497 const std::string &cmdString() const { return cmd.toString(); }
498
499 /// Return the index of this command.
500 inline int cmdToIndex() const { return cmd.toInt(); }
501
502 bool isRead() const { return cmd.isRead(); }
503 bool isWrite() const { return cmd.isWrite(); }
504 bool isUpgrade() const { return cmd.isUpgrade(); }
505 bool isRequest() const { return cmd.isRequest(); }
506 bool isResponse() const { return cmd.isResponse(); }
507 bool needsWritable() const
508 {
509 // we should never check if a response needsWritable, the
510 // request has this flag, and for a response we should rather
511 // look at the hasSharers flag (if not set, the response is to
512 // be considered writable)
513 assert(isRequest());
514 return cmd.needsWritable();
515 }
516 bool needsResponse() const { return cmd.needsResponse(); }
517 bool isInvalidate() const { return cmd.isInvalidate(); }
518 bool isEviction() const { return cmd.isEviction(); }
519 bool fromCache() const { return cmd.fromCache(); }
520 bool isWriteback() const { return cmd.isWriteback(); }
521 bool hasData() const { return cmd.hasData(); }
522 bool hasRespData() const
523 {
524 MemCmd resp_cmd = cmd.responseCommand();
525 return resp_cmd.hasData();
526 }
527 bool isLLSC() const { return cmd.isLLSC(); }
528 bool isError() const { return cmd.isError(); }
529 bool isPrint() const { return cmd.isPrint(); }
530 bool isFlush() const { return cmd.isFlush(); }
531
532 //@{
533 /// Snoop flags
534 /**
535 * Set the cacheResponding flag. This is used by the caches to
536 * signal another cache that they are responding to a request. A
537 * cache will only respond to snoops if it has the line in either
538 * Modified or Owned state. Note that on snoop hits we always pass
539 * the line as Modified and never Owned. In the case of an Owned
540 * line we proceed to invalidate all other copies.
541 *
542 * On a cache fill (see Cache::handleFill), we check hasSharers
543 * first, ignoring the cacheResponding flag if hasSharers is set.
544 * A line is consequently allocated as:
545 *
546 * hasSharers cacheResponding state
547 * true false Shared
548 * true true Shared
549 * false false Exclusive
550 * false true Modified
551 */
552 void setCacheResponding()
553 {
554 assert(isRequest());
555 assert(!flags.isSet(CACHE_RESPONDING));
556 flags.set(CACHE_RESPONDING);
557 }
558 bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); }
559 /**
560 * On fills, the hasSharers flag is used by the caches in
561 * combination with the cacheResponding flag, as clarified
562 * above. If the hasSharers flag is not set, the packet is passing
563 * writable. Thus, a response from a memory passes the line as
564 * writable by default.
565 *
566 * The hasSharers flag is also used by upstream caches to inform a
567 * downstream cache that they have the block (by calling
568 * setHasSharers on snoop request packets that hit in upstream
569 * cachs tags or MSHRs). If the snoop packet has sharers, a
570 * downstream cache is prevented from passing a dirty line upwards
571 * if it was not explicitly asked for a writable copy. See
572 * Cache::satisfyCpuSideRequest.
573 *
574 * The hasSharers flag is also used on writebacks, in
575 * combination with the WritbackClean or WritebackDirty commands,
576 * to allocate the block downstream either as:
577 *
578 * command hasSharers state
579 * WritebackDirty false Modified
580 * WritebackDirty true Owned
581 * WritebackClean false Exclusive
582 * WritebackClean true Shared
583 */
584 void setHasSharers() { flags.set(HAS_SHARERS); }
585 bool hasSharers() const { return flags.isSet(HAS_SHARERS); }
586 //@}
587
588 /**
589 * The express snoop flag is used for two purposes. Firstly, it is
590 * used to bypass flow control for normal (non-snoop) requests
591 * going downstream in the memory system. In cases where a cache
592 * is responding to a snoop from another cache (it had a dirty
593 * line), but the line is not writable (and there are possibly
594 * other copies), the express snoop flag is set by the downstream
595 * cache to invalidate all other copies in zero time. Secondly,
596 * the express snoop flag is also set to be able to distinguish
597 * snoop packets that came from a downstream cache, rather than
598 * snoop packets from neighbouring caches.
599 */
600 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); }
601 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); }
602
603 /**
604 * On responding to a snoop request (which only happens for
605 * Modified or Owned lines), make sure that we can transform an
606 * Owned response to a Modified one. If this flag is not set, the
607 * responding cache had the line in the Owned state, and there are
608 * possibly other Shared copies in the memory system. A downstream
609 * cache helps in orchestrating the invalidation of these copies
610 * by sending out the appropriate express snoops.
611 */
612 void setResponderHadWritable()
613 {
614 assert(cacheResponding());
615 assert(!responderHadWritable());
616 flags.set(RESPONDER_HAD_WRITABLE);
617 }
618 bool responderHadWritable() const
619 { return flags.isSet(RESPONDER_HAD_WRITABLE); }
620
621 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); }
622 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); }
623 void setBlockCached() { flags.set(BLOCK_CACHED); }
624 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); }
625 void clearBlockCached() { flags.clear(BLOCK_CACHED); }
626
627 // Network error conditions... encapsulate them as methods since
628 // their encoding keeps changing (from result field to command
629 // field, etc.)
630 void
631 setBadAddress()
632 {
633 assert(isResponse());
634 cmd = MemCmd::BadAddressError;
635 }
636
637 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
638
639 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
640 /**
641 * Update the address of this packet mid-transaction. This is used
642 * by the address mapper to change an already set address to a new
643 * one based on the system configuration. It is intended to remap
644 * an existing address, so it asserts that the current address is
645 * valid.
646 */
647 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; }
648
649 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; }
650
651 Addr getOffset(unsigned int blk_size) const
652 {
653 return getAddr() & Addr(blk_size - 1);
654 }
655
656 Addr getBlockAddr(unsigned int blk_size) const
657 {
658 return getAddr() & ~(Addr(blk_size - 1));
659 }
660
661 bool isSecure() const
662 {
663 assert(flags.isSet(VALID_ADDR));
664 return _isSecure;
665 }
666
667 /**
668 * Accessor function to atomic op.
669 */
670 AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); }
671 bool isAtomicOp() const { return req->isAtomic(); }
672
673 /**
674 * It has been determined that the SC packet should successfully update
675 * memory. Therefore, convert this SC packet to a normal write.
676 */
677 void
678 convertScToWrite()
679 {
680 assert(isLLSC());
681 assert(isWrite());
682 cmd = MemCmd::WriteReq;
683 }
684
685 /**
686 * When ruby is in use, Ruby will monitor the cache line and the
687 * phys memory should treat LL ops as normal reads.
688 */
689 void
690 convertLlToRead()
691 {
692 assert(isLLSC());
693 assert(isRead());
694 cmd = MemCmd::ReadReq;
695 }
696
697 /**
698 * Constructor. Note that a Request object must be constructed
699 * first, but the Requests's physical address and size fields need
700 * not be valid. The command must be supplied.
701 */
702 Packet(const RequestPtr _req, MemCmd _cmd)
703 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false),
704 size(0), headerDelay(0), snoopDelay(0), payloadDelay(0),
705 senderState(NULL)
706 {
707 if (req->hasPaddr()) {
708 addr = req->getPaddr();
709 flags.set(VALID_ADDR);
710 _isSecure = req->isSecure();
711 }
712 if (req->hasSize()) {
713 size = req->getSize();
714 flags.set(VALID_SIZE);
715 }
716 }
717
718 /**
719 * Alternate constructor if you are trying to create a packet with
720 * a request that is for a whole block, not the address from the
721 * req. this allows for overriding the size/addr of the req.
722 */
723 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize)
724 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false),
725 headerDelay(0), snoopDelay(0), payloadDelay(0),
726 senderState(NULL)
727 {
728 if (req->hasPaddr()) {
729 addr = req->getPaddr() & ~(_blkSize - 1);
730 flags.set(VALID_ADDR);
731 _isSecure = req->isSecure();
732 }
733 size = _blkSize;
734 flags.set(VALID_SIZE);
735 }
736
737 /**
738 * Alternate constructor for copying a packet. Copy all fields
739 * *except* if the original packet's data was dynamic, don't copy
740 * that, as we can't guarantee that the new packet's lifetime is
741 * less than that of the original packet. In this case the new
742 * packet should allocate its own data.
743 */
744 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data)
745 : cmd(pkt->cmd), req(pkt->req),
746 data(nullptr),
747 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size),
748 bytesValid(pkt->bytesValid),
749 headerDelay(pkt->headerDelay),
750 snoopDelay(0),
751 payloadDelay(pkt->payloadDelay),
752 senderState(pkt->senderState)
753 {
754 if (!clear_flags)
755 flags.set(pkt->flags & COPY_FLAGS);
756
757 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE));
758
759 // should we allocate space for data, or not, the express
760 // snoops do not need to carry any data as they only serve to
761 // co-ordinate state changes
762 if (alloc_data) {
763 // even if asked to allocate data, if the original packet
764 // holds static data, then the sender will not be doing
765 // any memcpy on receiving the response, thus we simply
766 // carry the pointer forward
767 if (pkt->flags.isSet(STATIC_DATA)) {
768 data = pkt->data;
769 flags.set(STATIC_DATA);
770 } else {
771 allocate();
772 }
773 }
774 }
775
776 /**
777 * Generate the appropriate read MemCmd based on the Request flags.
778 */
779 static MemCmd
780 makeReadCmd(const RequestPtr req)
781 {
782 if (req->isLLSC())
783 return MemCmd::LoadLockedReq;
784 else if (req->isPrefetch())
785 return MemCmd::SoftPFReq;
786 else
787 return MemCmd::ReadReq;
788 }
789
790 /**
791 * Generate the appropriate write MemCmd based on the Request flags.
792 */
793 static MemCmd
794 makeWriteCmd(const RequestPtr req)
795 {
796 if (req->isLLSC())
797 return MemCmd::StoreCondReq;
798 else if (req->isSwap())
799 return MemCmd::SwapReq;
800 else
801 return MemCmd::WriteReq;
802 }
803
804 /**
805 * Constructor-like methods that return Packets based on Request objects.
806 * Fine-tune the MemCmd type if it's not a vanilla read or write.
807 */
808 static PacketPtr
809 createRead(const RequestPtr req)
810 {
811 return new Packet(req, makeReadCmd(req));
812 }
813
814 static PacketPtr
815 createWrite(const RequestPtr req)
816 {
817 return new Packet(req, makeWriteCmd(req));
818 }
819
820 /**
821 * clean up packet variables
822 */
823 ~Packet()
824 {
825 // Delete the request object if this is a request packet which
826 // does not need a response, because the requester will not get
827 // a chance. If the request packet needs a response then the
828 // request will be deleted on receipt of the response
829 // packet. We also make sure to never delete the request for
830 // express snoops, even for cases when responses are not
831 // needed (CleanEvict and Writeback), since the snoop packet
832 // re-uses the same request.
833 if (req && isRequest() && !needsResponse() &&
834 !isExpressSnoop()) {
835 delete req;
836 }
837 deleteData();
838 }
839
840 /**
841 * Take a request packet and modify it in place to be suitable for
842 * returning as a response to that request.
843 */
844 void
845 makeResponse()
846 {
847 assert(needsResponse());
848 assert(isRequest());
849 cmd = cmd.responseCommand();
850
851 // responses are never express, even if the snoop that
852 // triggered them was
853 flags.clear(EXPRESS_SNOOP);
854 }
855
856 void
857 makeAtomicResponse()
858 {
859 makeResponse();
860 }
861
862 void
863 makeTimingResponse()
864 {
865 makeResponse();
866 }
867
868 void
869 setFunctionalResponseStatus(bool success)
870 {
871 if (!success) {
872 if (isWrite()) {
873 cmd = MemCmd::FunctionalWriteError;
874 } else {
875 cmd = MemCmd::FunctionalReadError;
876 }
877 }
878 }
879
880 void
881 setSize(unsigned size)
882 {
883 assert(!flags.isSet(VALID_SIZE));
884
885 this->size = size;
886 flags.set(VALID_SIZE);
887 }
888
889
890 public:
891 /**
892 * @{
893 * @name Data accessor mehtods
894 */
895
896 /**
897 * Set the data pointer to the following value that should not be
898 * freed. Static data allows us to do a single memcpy even if
899 * multiple packets are required to get from source to destination
900 * and back. In essence the pointer is set calling dataStatic on
901 * the original packet, and whenever this packet is copied and
902 * forwarded the same pointer is passed on. When a packet
903 * eventually reaches the destination holding the data, it is
904 * copied once into the location originally set. On the way back
905 * to the source, no copies are necessary.
906 */
907 template <typename T>
908 void
909 dataStatic(T *p)
910 {
911 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
912 data = (PacketDataPtr)p;
913 flags.set(STATIC_DATA);
914 }
915
916 /**
917 * Set the data pointer to the following value that should not be
918 * freed. This version of the function allows the pointer passed
919 * to us to be const. To avoid issues down the line we cast the
920 * constness away, the alternative would be to keep both a const
921 * and non-const data pointer and cleverly choose between
922 * them. Note that this is only allowed for static data.
923 */
924 template <typename T>
925 void
926 dataStaticConst(const T *p)
927 {
928 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
929 data = const_cast<PacketDataPtr>(p);
930 flags.set(STATIC_DATA);
931 }
932
933 /**
934 * Set the data pointer to a value that should have delete []
935 * called on it. Dynamic data is local to this packet, and as the
936 * packet travels from source to destination, forwarded packets
937 * will allocate their own data. When a packet reaches the final
938 * destination it will populate the dynamic data of that specific
939 * packet, and on the way back towards the source, memcpy will be
940 * invoked in every step where a new packet was created e.g. in
941 * the caches. Ultimately when the response reaches the source a
942 * final memcpy is needed to extract the data from the packet
943 * before it is deallocated.
944 */
945 template <typename T>
946 void
947 dataDynamic(T *p)
948 {
949 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
950 data = (PacketDataPtr)p;
951 flags.set(DYNAMIC_DATA);
952 }
953
954 /**
955 * get a pointer to the data ptr.
956 */
957 template <typename T>
958 T*
959 getPtr()
960 {
961 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
962 return (T*)data;
963 }
964
965 template <typename T>
966 const T*
967 getConstPtr() const
968 {
969 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
970 return (const T*)data;
971 }
972
973 /**
974 * Get the data in the packet byte swapped from big endian to
975 * host endian.
976 */
977 template <typename T>
978 T getBE() const;
979
980 /**
981 * Get the data in the packet byte swapped from little endian to
982 * host endian.
983 */
984 template <typename T>
985 T getLE() const;
986
987 /**
988 * Get the data in the packet byte swapped from the specified
989 * endianness.
990 */
991 template <typename T>
992 T get(ByteOrder endian) const;
993
994 /**
995 * Get the data in the packet byte swapped from guest to host
996 * endian.
997 */
998 template <typename T>
999 T get() const;
1000
1001 /** Set the value in the data pointer to v as big endian. */
1002 template <typename T>
1003 void setBE(T v);
1004
1005 /** Set the value in the data pointer to v as little endian. */
1006 template <typename T>
1007 void setLE(T v);
1008
1009 /**
1010 * Set the value in the data pointer to v using the specified
1011 * endianness.
1012 */
1013 template <typename T>
1014 void set(T v, ByteOrder endian);
1015
1016 /** Set the value in the data pointer to v as guest endian. */
1017 template <typename T>
1018 void set(T v);
1019
1020 /**
1021 * Copy data into the packet from the provided pointer.
1022 */
1023 void
1024 setData(const uint8_t *p)
1025 {
1026 // we should never be copying data onto itself, which means we
1027 // must idenfity packets with static data, as they carry the
1028 // same pointer from source to destination and back
1029 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA));
1030
1031 if (p != getPtr<uint8_t>())
1032 // for packet with allocated dynamic data, we copy data from
1033 // one to the other, e.g. a forwarded response to a response
1034 std::memcpy(getPtr<uint8_t>(), p, getSize());
1035 }
1036
1037 /**
1038 * Copy data into the packet from the provided block pointer,
1039 * which is aligned to the given block size.
1040 */
1041 void
1042 setDataFromBlock(const uint8_t *blk_data, int blkSize)
1043 {
1044 setData(blk_data + getOffset(blkSize));
1045 }
1046
1047 /**
1048 * Copy data from the packet to the provided block pointer, which
1049 * is aligned to the given block size.
1050 */
1051 void
1052 writeData(uint8_t *p) const
1053 {
1054 std::memcpy(p, getConstPtr<uint8_t>(), getSize());
1055 }
1056
1057 /**
1058 * Copy data from the packet to the memory at the provided pointer.
1059 */
1060 void
1061 writeDataToBlock(uint8_t *blk_data, int blkSize) const
1062 {
1063 writeData(blk_data + getOffset(blkSize));
1064 }
1065
1066 /**
1067 * delete the data pointed to in the data pointer. Ok to call to
1068 * matter how data was allocted.
1069 */
1070 void
1071 deleteData()
1072 {
1073 if (flags.isSet(DYNAMIC_DATA))
1074 delete [] data;
1075
1076 flags.clear(STATIC_DATA|DYNAMIC_DATA);
1077 data = NULL;
1078 }
1079
1080 /** Allocate memory for the packet. */
1081 void
1082 allocate()
1083 {
1084 // if either this command or the response command has a data
1085 // payload, actually allocate space
1086 if (hasData() || hasRespData()) {
1087 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1088 flags.set(DYNAMIC_DATA);
1089 data = new uint8_t[getSize()];
1090 }
1091 }
1092
1093 /** @} */
1094
1095 private: // Private data accessor methods
1096 /** Get the data in the packet without byte swapping. */
1097 template <typename T>
1098 T getRaw() const;
1099
1100 /** Set the value in the data pointer to v without byte swapping. */
1101 template <typename T>
1102 void setRaw(T v);
1103
1104 public:
1105 /**
1106 * Check a functional request against a memory value stored in
1107 * another packet (i.e. an in-transit request or
1108 * response). Returns true if the current packet is a read, and
1109 * the other packet provides the data, which is then copied to the
1110 * current packet. If the current packet is a write, and the other
1111 * packet intersects this one, then we update the data
1112 * accordingly.
1113 */
1114 bool
1115 checkFunctional(PacketPtr other)
1116 {
1117 // all packets that are carrying a payload should have a valid
1118 // data pointer
1119 return checkFunctional(other, other->getAddr(), other->isSecure(),
1120 other->getSize(),
1121 other->hasData() ?
1122 other->getPtr<uint8_t>() : NULL);
1123 }
1124
1125 /**
1126 * Does the request need to check for cached copies of the same block
1127 * in the memory hierarchy above.
1128 **/
1129 bool
1130 mustCheckAbove() const
1131 {
1132 return cmd == MemCmd::HardPFReq || isEviction();
1133 }
1134
1135 /**
1136 * Is this packet a clean eviction, including both actual clean
1137 * evict packets, but also clean writebacks.
1138 */
1139 bool
1140 isCleanEviction() const
1141 {
1142 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean;
1143 }
1144
1145 /**
1146 * Check a functional request against a memory value represented
1147 * by a base/size pair and an associated data array. If the
1148 * current packet is a read, it may be satisfied by the memory
1149 * value. If the current packet is a write, it may update the
1150 * memory value.
1151 */
1152 bool
1153 checkFunctional(Printable *obj, Addr base, bool is_secure, int size,
1154 uint8_t *_data);
1155
1156 /**
1157 * Push label for PrintReq (safe to call unconditionally).
1158 */
1159 void
1160 pushLabel(const std::string &lbl)
1161 {
1162 if (isPrint())
1163 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
1164 }
1165
1166 /**
1167 * Pop label for PrintReq (safe to call unconditionally).
1168 */
1169 void
1170 popLabel()
1171 {
1172 if (isPrint())
1173 safe_cast<PrintReqState*>(senderState)->popLabel();
1174 }
1175
1176 void print(std::ostream &o, int verbosity = 0,
1177 const std::string &prefix = "") const;
1178
1179 /**
1180 * A no-args wrapper of print(std::ostream...)
1181 * meant to be invoked from DPRINTFs
1182 * avoiding string overheads in fast mode
1183 * @return string with the request's type and start<->end addresses
1184 */
1185 std::string print() const;
1186};
1187
1188#endif //__MEM_PACKET_HH
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