2 * Copyright (c) 2012-2018 ARM Limited
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder. You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
14 * Copyright (c) 2006 The Regents of The University of Michigan
15 * Copyright (c) 2010,2015 Advanced Micro Devices, Inc.
16 * All rights reserved.
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions are
20 * met: redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer;
22 * redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution;
25 * neither the name of the copyright holders nor the names of its
26 * contributors may be used to endorse or promote products derived from
27 * this software without specific prior written permission.
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
30 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
31 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
32 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
33 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
34 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
35 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
39 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41 * Authors: Ron Dreslinski
50 * Declaration of the Packet class.
53 #ifndef __MEM_PACKET_HH__
54 #define __MEM_PACKET_HH__
60 #include "base/cast.hh"
61 #include "base/compiler.hh"
62 #include "base/flags.hh"
63 #include "base/logging.hh"
64 #include "base/printable.hh"
65 #include "base/types.hh"
66 #include "config/the_isa.hh"
67 #include "mem/request.hh"
68 #include "sim/core.hh"
71 typedef Packet *PacketPtr;
72 typedef uint8_t* PacketDataPtr;
73 typedef std::list<PacketPtr> PacketList;
74 typedef uint64_t PacketId;
82 * List of all commands associated with a packet.
89 ReadRespWithInvalidate,
94 WriteClean, // writes dirty data below without evicting
103 SCUpgradeReq, // Special "weak" upgrade for StoreCond
105 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent)
106 UpgradeFailResp, // Valid for SCUpgradeReq only
113 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent)
126 // @TODO these should be classified as responses rather than
127 // requests; coding them as requests initially for backwards
129 InvalidDestError, // packet dest field invalid
130 BadAddressError, // memory address invalid
131 FunctionalReadError, // unable to fulfill functional read
132 FunctionalWriteError, // unable to fulfill functional write
133 // Fake simulator-only commands
134 PrintReq, // Print state matching address
135 FlushReq, //request for a cache flush
136 InvalidateReq, // request for address to be invalidated
143 * List of command attributes.
147 IsRead, //!< Data flows from responder to requester
148 IsWrite, //!< Data flows from requester to responder
151 IsClean, //!< Cleans any existing dirty blocks
152 NeedsWritable, //!< Requires writable copy to complete in-cache
153 IsRequest, //!< Issued by requester
154 IsResponse, //!< Issue by responder
155 NeedsResponse, //!< Requester needs response from target
159 IsLlsc, //!< Alpha/MIPS LL or SC access
160 HasData, //!< There is an associated payload
161 IsError, //!< Error response
162 IsPrint, //!< Print state matching address (for debugging)
163 IsFlush, //!< Flush the address from caches
164 FromCache, //!< Request originated from a caching agent
165 NUM_COMMAND_ATTRIBUTES
169 * Structure that defines attributes and other data associated
174 /// Set of attribute flags.
175 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
176 /// Corresponding response for requests; InvalidCmd if no
177 /// response is applicable.
178 const Command response;
179 /// String representation (for printing)
180 const std::string str;
183 /// Array to map Command enum to associated info.
184 static const CommandInfo commandInfo[];
191 testCmdAttrib(MemCmd::Attribute attrib) const
193 return commandInfo[cmd].attributes[attrib] != 0;
198 bool isRead() const { return testCmdAttrib(IsRead); }
199 bool isWrite() const { return testCmdAttrib(IsWrite); }
200 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); }
201 bool isRequest() const { return testCmdAttrib(IsRequest); }
202 bool isResponse() const { return testCmdAttrib(IsResponse); }
203 bool needsWritable() const { return testCmdAttrib(NeedsWritable); }
204 bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
205 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
206 bool isEviction() const { return testCmdAttrib(IsEviction); }
207 bool isClean() const { return testCmdAttrib(IsClean); }
208 bool fromCache() const { return testCmdAttrib(FromCache); }
211 * A writeback is an eviction that carries data.
213 bool isWriteback() const { return testCmdAttrib(IsEviction) &&
214 testCmdAttrib(HasData); }
217 * Check if this particular packet type carries payload data. Note
218 * that this does not reflect if the data pointer of the packet is
221 bool hasData() const { return testCmdAttrib(HasData); }
222 bool isLLSC() const { return testCmdAttrib(IsLlsc); }
223 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); }
224 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); }
225 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) ||
226 testCmdAttrib(IsHWPrefetch); }
227 bool isError() const { return testCmdAttrib(IsError); }
228 bool isPrint() const { return testCmdAttrib(IsPrint); }
229 bool isFlush() const { return testCmdAttrib(IsFlush); }
232 responseCommand() const
234 return commandInfo[cmd].response;
237 /// Return the string to a cmd given by idx.
238 const std::string &toString() const { return commandInfo[cmd].str; }
239 int toInt() const { return (int)cmd; }
241 MemCmd(Command _cmd) : cmd(_cmd) { }
242 MemCmd(int _cmd) : cmd((Command)_cmd) { }
243 MemCmd() : cmd(InvalidCmd) { }
245 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
246 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
250 * A Packet is used to encapsulate a transfer between two objects in
251 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
252 * single Request travels all the way from the requester to the
253 * ultimate destination and back, possibly being conveyed by several
254 * different Packets along the way.)
256 class Packet : public Printable
259 typedef uint32_t FlagsType;
260 typedef ::Flags<FlagsType> Flags;
265 // Flags to transfer across when copying a packet
266 COPY_FLAGS = 0x0000003F,
268 // Does this packet have sharers (which means it should not be
269 // considered writable) or not. See setHasSharers below.
270 HAS_SHARERS = 0x00000001,
272 // Special control flags
273 /// Special timing-mode atomic snoop for multi-level coherence.
274 EXPRESS_SNOOP = 0x00000002,
276 /// Allow a responding cache to inform the cache hierarchy
277 /// that it had a writable copy before responding. See
278 /// setResponderHadWritable below.
279 RESPONDER_HAD_WRITABLE = 0x00000004,
281 // Snoop co-ordination flag to indicate that a cache is
282 // responding to a snoop. See setCacheResponding below.
283 CACHE_RESPONDING = 0x00000008,
285 // The writeback/writeclean should be propagated further
286 // downstream by the receiver
287 WRITE_THROUGH = 0x00000010,
289 // Response co-ordination flag for cache maintenance
291 SATISFIED = 0x00000020,
293 /// Are the 'addr' and 'size' fields valid?
294 VALID_ADDR = 0x00000100,
295 VALID_SIZE = 0x00000200,
297 /// Is the data pointer set to a value that shouldn't be freed
298 /// when the packet is destroyed?
299 STATIC_DATA = 0x00001000,
300 /// The data pointer points to a value that should be freed when
301 /// the packet is destroyed. The pointer is assumed to be pointing
302 /// to an array, and delete [] is consequently called
303 DYNAMIC_DATA = 0x00002000,
305 /// suppress the error if this packet encounters a functional
307 SUPPRESS_FUNC_ERROR = 0x00008000,
309 // Signal block present to squash prefetch and cache evict packets
310 // through express snoop flag
311 BLOCK_CACHED = 0x00010000
317 typedef MemCmd::Command Command;
319 /// The command field of the packet.
324 /// A pointer to the original request.
329 * A pointer to the data being transferred. It can be different
330 * sizes at each level of the hierarchy so it belongs to the
331 * packet, not request. This may or may not be populated when a
332 * responder receives the packet. If not populated memory should
337 /// The address of the request. This address could be virtual or
338 /// physical, depending on the system configuration.
341 /// True if the request targets the secure memory space.
344 /// The size of the request or transfer.
348 * Track the bytes found that satisfy a functional read.
350 std::vector<bool> bytesValid;
352 // Quality of Service priority value
358 * The extra delay from seeing the packet until the header is
359 * transmitted. This delay is used to communicate the crossbar
360 * forwarding latency to the neighbouring object (e.g. a cache)
361 * that actually makes the packet wait. As the delay is relative,
362 * a 32-bit unsigned should be sufficient.
364 uint32_t headerDelay;
367 * Keep track of the extra delay incurred by snooping upwards
368 * before sending a request down the memory system. This is used
369 * by the coherent crossbar to account for the additional request
375 * The extra pipelining delay from seeing the packet until the end of
376 * payload is transmitted by the component that provided it (if
377 * any). This includes the header delay. Similar to the header
378 * delay, this is used to make up for the fact that the
379 * crossbar does not make the packet wait. As the delay is
380 * relative, a 32-bit unsigned should be sufficient.
382 uint32_t payloadDelay;
385 * A virtual base opaque structure used to hold state associated
386 * with the packet (e.g., an MSHR), specific to a MemObject that
387 * sees the packet. A pointer to this state is returned in the
388 * packet's response so that the MemObject in question can quickly
389 * look up the state needed to process it. A specific subclass
390 * would be derived from this to carry state specific to a
391 * particular sending device.
393 * As multiple MemObjects may add their SenderState throughout the
394 * memory system, the SenderStates create a stack, where a
395 * MemObject can add a new Senderstate, as long as the
396 * predecessing SenderState is restored when the response comes
397 * back. For this reason, the predecessor should always be
398 * populated with the current SenderState of a packet before
399 * modifying the senderState field in the request packet.
403 SenderState* predecessor;
404 SenderState() : predecessor(NULL) {}
405 virtual ~SenderState() {}
409 * Object used to maintain state of a PrintReq. The senderState
410 * field of a PrintReq should always be of this type.
412 class PrintReqState : public SenderState
416 * An entry in the label stack.
418 struct LabelStackEntry
420 const std::string label;
423 LabelStackEntry(const std::string &_label, std::string *_prefix);
426 typedef std::list<LabelStackEntry> LabelStack;
427 LabelStack labelStack;
429 std::string *curPrefixPtr;
435 PrintReqState(std::ostream &os, int verbosity = 0);
439 * Returns the current line prefix.
441 const std::string &curPrefix() { return *curPrefixPtr; }
444 * Push a label onto the label stack, and prepend the given
445 * prefix string onto the current prefix. Labels will only be
446 * printed if an object within the label's scope is printed.
448 void pushLabel(const std::string &lbl,
449 const std::string &prefix = " ");
452 * Pop a label off the label stack.
457 * Print all of the pending unprinted labels on the
458 * stack. Called by printObj(), so normally not called by
459 * users unless bypassing printObj().
464 * Print a Printable object to os, because it matched the
465 * address on a PrintReq.
467 void printObj(Printable *obj);
471 * This packet's sender state. Devices should use dynamic_cast<>
472 * to cast to the state appropriate to the sender. The intent of
473 * this variable is to allow a device to attach extra information
474 * to a request. A response packet must return the sender state
475 * that was attached to the original request (even if a new packet
478 SenderState *senderState;
481 * Push a new sender state to the packet and make the current
482 * sender state the predecessor of the new one. This should be
483 * prefered over direct manipulation of the senderState member
486 * @param sender_state SenderState to push at the top of the stack
488 void pushSenderState(SenderState *sender_state);
491 * Pop the top of the state stack and return a pointer to it. This
492 * assumes the current sender state is not NULL. This should be
493 * preferred over direct manipulation of the senderState member
496 * @return The current top of the stack
498 SenderState *popSenderState();
501 * Go through the sender state stack and return the first instance
502 * that is of type T (as determined by a dynamic_cast). If there
503 * is no sender state of type T, NULL is returned.
505 * @return The topmost state of type T
507 template <typename T>
508 T * findNextSenderState() const
511 SenderState* sender_state = senderState;
512 while (t == NULL && sender_state != NULL) {
513 t = dynamic_cast<T*>(sender_state);
514 sender_state = sender_state->predecessor;
519 /// Return the string name of the cmd field (for debugging and
521 const std::string &cmdString() const { return cmd.toString(); }
523 /// Return the index of this command.
524 inline int cmdToIndex() const { return cmd.toInt(); }
526 bool isRead() const { return cmd.isRead(); }
527 bool isWrite() const { return cmd.isWrite(); }
528 bool isUpgrade() const { return cmd.isUpgrade(); }
529 bool isRequest() const { return cmd.isRequest(); }
530 bool isResponse() const { return cmd.isResponse(); }
531 bool needsWritable() const
533 // we should never check if a response needsWritable, the
534 // request has this flag, and for a response we should rather
535 // look at the hasSharers flag (if not set, the response is to
536 // be considered writable)
538 return cmd.needsWritable();
540 bool needsResponse() const { return cmd.needsResponse(); }
541 bool isInvalidate() const { return cmd.isInvalidate(); }
542 bool isEviction() const { return cmd.isEviction(); }
543 bool isClean() const { return cmd.isClean(); }
544 bool fromCache() const { return cmd.fromCache(); }
545 bool isWriteback() const { return cmd.isWriteback(); }
546 bool hasData() const { return cmd.hasData(); }
547 bool hasRespData() const
549 MemCmd resp_cmd = cmd.responseCommand();
550 return resp_cmd.hasData();
552 bool isLLSC() const { return cmd.isLLSC(); }
553 bool isError() const { return cmd.isError(); }
554 bool isPrint() const { return cmd.isPrint(); }
555 bool isFlush() const { return cmd.isFlush(); }
557 bool isWholeLineWrite(unsigned blk_size)
559 return (cmd == MemCmd::WriteReq || cmd == MemCmd::WriteLineReq) &&
560 getOffset(blk_size) == 0 && getSize() == blk_size;
566 * Set the cacheResponding flag. This is used by the caches to
567 * signal another cache that they are responding to a request. A
568 * cache will only respond to snoops if it has the line in either
569 * Modified or Owned state. Note that on snoop hits we always pass
570 * the line as Modified and never Owned. In the case of an Owned
571 * line we proceed to invalidate all other copies.
573 * On a cache fill (see Cache::handleFill), we check hasSharers
574 * first, ignoring the cacheResponding flag if hasSharers is set.
575 * A line is consequently allocated as:
577 * hasSharers cacheResponding state
580 * false false Exclusive
581 * false true Modified
583 void setCacheResponding()
586 assert(!flags.isSet(CACHE_RESPONDING));
587 flags.set(CACHE_RESPONDING);
589 bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); }
591 * On fills, the hasSharers flag is used by the caches in
592 * combination with the cacheResponding flag, as clarified
593 * above. If the hasSharers flag is not set, the packet is passing
594 * writable. Thus, a response from a memory passes the line as
595 * writable by default.
597 * The hasSharers flag is also used by upstream caches to inform a
598 * downstream cache that they have the block (by calling
599 * setHasSharers on snoop request packets that hit in upstream
600 * cachs tags or MSHRs). If the snoop packet has sharers, a
601 * downstream cache is prevented from passing a dirty line upwards
602 * if it was not explicitly asked for a writable copy. See
603 * Cache::satisfyCpuSideRequest.
605 * The hasSharers flag is also used on writebacks, in
606 * combination with the WritbackClean or WritebackDirty commands,
607 * to allocate the block downstream either as:
609 * command hasSharers state
610 * WritebackDirty false Modified
611 * WritebackDirty true Owned
612 * WritebackClean false Exclusive
613 * WritebackClean true Shared
615 void setHasSharers() { flags.set(HAS_SHARERS); }
616 bool hasSharers() const { return flags.isSet(HAS_SHARERS); }
620 * The express snoop flag is used for two purposes. Firstly, it is
621 * used to bypass flow control for normal (non-snoop) requests
622 * going downstream in the memory system. In cases where a cache
623 * is responding to a snoop from another cache (it had a dirty
624 * line), but the line is not writable (and there are possibly
625 * other copies), the express snoop flag is set by the downstream
626 * cache to invalidate all other copies in zero time. Secondly,
627 * the express snoop flag is also set to be able to distinguish
628 * snoop packets that came from a downstream cache, rather than
629 * snoop packets from neighbouring caches.
631 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); }
632 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); }
635 * On responding to a snoop request (which only happens for
636 * Modified or Owned lines), make sure that we can transform an
637 * Owned response to a Modified one. If this flag is not set, the
638 * responding cache had the line in the Owned state, and there are
639 * possibly other Shared copies in the memory system. A downstream
640 * cache helps in orchestrating the invalidation of these copies
641 * by sending out the appropriate express snoops.
643 void setResponderHadWritable()
645 assert(cacheResponding());
646 assert(!responderHadWritable());
647 flags.set(RESPONDER_HAD_WRITABLE);
649 bool responderHadWritable() const
650 { return flags.isSet(RESPONDER_HAD_WRITABLE); }
653 * A writeback/writeclean cmd gets propagated further downstream
654 * by the receiver when the flag is set.
656 void setWriteThrough()
658 assert(cmd.isWrite() &&
659 (cmd.isEviction() || cmd == MemCmd::WriteClean));
660 flags.set(WRITE_THROUGH);
662 void clearWriteThrough() { flags.clear(WRITE_THROUGH); }
663 bool writeThrough() const { return flags.isSet(WRITE_THROUGH); }
666 * Set when a request hits in a cache and the cache is not going
667 * to respond. This is used by the crossbar to coordinate
668 * responses for cache maintenance operations.
672 assert(cmd.isClean());
673 assert(!flags.isSet(SATISFIED));
674 flags.set(SATISFIED);
676 bool satisfied() const { return flags.isSet(SATISFIED); }
678 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); }
679 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); }
680 void setBlockCached() { flags.set(BLOCK_CACHED); }
681 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); }
682 void clearBlockCached() { flags.clear(BLOCK_CACHED); }
686 * Returns 0 if QoS value was never set (constructor default).
688 * @return QoS priority value of the packet
690 inline uint8_t qosValue() const { return _qosValue; }
694 * Interface for setting QoS priority value of the packet.
696 * @param qos_value QoS priority value
698 inline void qosValue(const uint8_t qos_value)
699 { _qosValue = qos_value; }
701 inline MasterID masterId() const { return req->masterId(); }
703 // Network error conditions... encapsulate them as methods since
704 // their encoding keeps changing (from result field to command
709 assert(isResponse());
710 cmd = MemCmd::BadAddressError;
713 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
715 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
717 * Update the address of this packet mid-transaction. This is used
718 * by the address mapper to change an already set address to a new
719 * one based on the system configuration. It is intended to remap
720 * an existing address, so it asserts that the current address is
723 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; }
725 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; }
727 Addr getOffset(unsigned int blk_size) const
729 return getAddr() & Addr(blk_size - 1);
732 Addr getBlockAddr(unsigned int blk_size) const
734 return getAddr() & ~(Addr(blk_size - 1));
737 bool isSecure() const
739 assert(flags.isSet(VALID_ADDR));
744 * Accessor function to atomic op.
746 AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); }
747 bool isAtomicOp() const { return req->isAtomic(); }
750 * It has been determined that the SC packet should successfully update
751 * memory. Therefore, convert this SC packet to a normal write.
758 cmd = MemCmd::WriteReq;
762 * When ruby is in use, Ruby will monitor the cache line and the
763 * phys memory should treat LL ops as normal reads.
770 cmd = MemCmd::ReadReq;
774 * Constructor. Note that a Request object must be constructed
775 * first, but the Requests's physical address and size fields need
776 * not be valid. The command must be supplied.
778 Packet(const RequestPtr &_req, MemCmd _cmd)
779 : cmd(_cmd), id((PacketId)_req.get()), req(_req),
780 data(nullptr), addr(0), _isSecure(false), size(0),
781 _qosValue(0), headerDelay(0), snoopDelay(0),
782 payloadDelay(0), senderState(NULL)
784 if (req->hasPaddr()) {
785 addr = req->getPaddr();
786 flags.set(VALID_ADDR);
787 _isSecure = req->isSecure();
789 if (req->hasSize()) {
790 size = req->getSize();
791 flags.set(VALID_SIZE);
796 * Alternate constructor if you are trying to create a packet with
797 * a request that is for a whole block, not the address from the
798 * req. this allows for overriding the size/addr of the req.
800 Packet(const RequestPtr &_req, MemCmd _cmd, int _blkSize, PacketId _id = 0)
801 : cmd(_cmd), id(_id ? _id : (PacketId)_req.get()), req(_req),
802 data(nullptr), addr(0), _isSecure(false),
803 _qosValue(0), headerDelay(0),
804 snoopDelay(0), payloadDelay(0), senderState(NULL)
806 if (req->hasPaddr()) {
807 addr = req->getPaddr() & ~(_blkSize - 1);
808 flags.set(VALID_ADDR);
809 _isSecure = req->isSecure();
812 flags.set(VALID_SIZE);
816 * Alternate constructor for copying a packet. Copy all fields
817 * *except* if the original packet's data was dynamic, don't copy
818 * that, as we can't guarantee that the new packet's lifetime is
819 * less than that of the original packet. In this case the new
820 * packet should allocate its own data.
822 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data)
823 : cmd(pkt->cmd), id(pkt->id), req(pkt->req),
825 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size),
826 bytesValid(pkt->bytesValid),
827 _qosValue(pkt->qosValue()),
828 headerDelay(pkt->headerDelay),
830 payloadDelay(pkt->payloadDelay),
831 senderState(pkt->senderState)
834 flags.set(pkt->flags & COPY_FLAGS);
836 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE));
838 // should we allocate space for data, or not, the express
839 // snoops do not need to carry any data as they only serve to
840 // co-ordinate state changes
842 // even if asked to allocate data, if the original packet
843 // holds static data, then the sender will not be doing
844 // any memcpy on receiving the response, thus we simply
845 // carry the pointer forward
846 if (pkt->flags.isSet(STATIC_DATA)) {
848 flags.set(STATIC_DATA);
856 * Generate the appropriate read MemCmd based on the Request flags.
859 makeReadCmd(const RequestPtr &req)
862 return MemCmd::LoadLockedReq;
863 else if (req->isPrefetchEx())
864 return MemCmd::SoftPFExReq;
865 else if (req->isPrefetch())
866 return MemCmd::SoftPFReq;
868 return MemCmd::ReadReq;
872 * Generate the appropriate write MemCmd based on the Request flags.
875 makeWriteCmd(const RequestPtr &req)
878 return MemCmd::StoreCondReq;
879 else if (req->isSwap() || req->isAtomic())
880 return MemCmd::SwapReq;
881 else if (req->isCacheInvalidate()) {
882 return req->isCacheClean() ? MemCmd::CleanInvalidReq :
883 MemCmd::InvalidateReq;
884 } else if (req->isCacheClean()) {
885 return MemCmd::CleanSharedReq;
887 return MemCmd::WriteReq;
891 * Constructor-like methods that return Packets based on Request objects.
892 * Fine-tune the MemCmd type if it's not a vanilla read or write.
895 createRead(const RequestPtr &req)
897 return new Packet(req, makeReadCmd(req));
901 createWrite(const RequestPtr &req)
903 return new Packet(req, makeWriteCmd(req));
907 * clean up packet variables
915 * Take a request packet and modify it in place to be suitable for
916 * returning as a response to that request.
921 assert(needsResponse());
923 cmd = cmd.responseCommand();
925 // responses are never express, even if the snoop that
926 // triggered them was
927 flags.clear(EXPRESS_SNOOP);
943 setFunctionalResponseStatus(bool success)
947 cmd = MemCmd::FunctionalWriteError;
949 cmd = MemCmd::FunctionalReadError;
955 setSize(unsigned size)
957 assert(!flags.isSet(VALID_SIZE));
960 flags.set(VALID_SIZE);
967 * @name Data accessor mehtods
971 * Set the data pointer to the following value that should not be
972 * freed. Static data allows us to do a single memcpy even if
973 * multiple packets are required to get from source to destination
974 * and back. In essence the pointer is set calling dataStatic on
975 * the original packet, and whenever this packet is copied and
976 * forwarded the same pointer is passed on. When a packet
977 * eventually reaches the destination holding the data, it is
978 * copied once into the location originally set. On the way back
979 * to the source, no copies are necessary.
981 template <typename T>
985 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
986 data = (PacketDataPtr)p;
987 flags.set(STATIC_DATA);
991 * Set the data pointer to the following value that should not be
992 * freed. This version of the function allows the pointer passed
993 * to us to be const. To avoid issues down the line we cast the
994 * constness away, the alternative would be to keep both a const
995 * and non-const data pointer and cleverly choose between
996 * them. Note that this is only allowed for static data.
998 template <typename T>
1000 dataStaticConst(const T *p)
1002 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1003 data = const_cast<PacketDataPtr>(p);
1004 flags.set(STATIC_DATA);
1008 * Set the data pointer to a value that should have delete []
1009 * called on it. Dynamic data is local to this packet, and as the
1010 * packet travels from source to destination, forwarded packets
1011 * will allocate their own data. When a packet reaches the final
1012 * destination it will populate the dynamic data of that specific
1013 * packet, and on the way back towards the source, memcpy will be
1014 * invoked in every step where a new packet was created e.g. in
1015 * the caches. Ultimately when the response reaches the source a
1016 * final memcpy is needed to extract the data from the packet
1017 * before it is deallocated.
1019 template <typename T>
1023 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1024 data = (PacketDataPtr)p;
1025 flags.set(DYNAMIC_DATA);
1029 * get a pointer to the data ptr.
1031 template <typename T>
1035 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
1039 template <typename T>
1043 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
1044 return (const T*)data;
1048 * Get the data in the packet byte swapped from big endian to
1051 template <typename T>
1055 * Get the data in the packet byte swapped from little endian to
1058 template <typename T>
1062 * Get the data in the packet byte swapped from the specified
1065 template <typename T>
1066 T get(ByteOrder endian) const;
1068 #if THE_ISA != NULL_ISA
1070 * Get the data in the packet byte swapped from guest to host
1073 template <typename T>
1075 M5_DEPRECATED_MSG("The memory system should be ISA independent.");
1078 /** Set the value in the data pointer to v as big endian. */
1079 template <typename T>
1082 /** Set the value in the data pointer to v as little endian. */
1083 template <typename T>
1087 * Set the value in the data pointer to v using the specified
1090 template <typename T>
1091 void set(T v, ByteOrder endian);
1093 #if THE_ISA != NULL_ISA
1094 /** Set the value in the data pointer to v as guest endian. */
1095 template <typename T>
1097 M5_DEPRECATED_MSG("The memory system should be ISA independent.");
1101 * Get the data in the packet byte swapped from the specified
1102 * endianness and zero-extended to 64 bits.
1104 uint64_t getUintX(ByteOrder endian) const;
1107 * Set the value in the word w after truncating it to the length
1108 * of the packet and then byteswapping it to the desired
1111 void setUintX(uint64_t w, ByteOrder endian);
1114 * Copy data into the packet from the provided pointer.
1117 setData(const uint8_t *p)
1119 // we should never be copying data onto itself, which means we
1120 // must idenfity packets with static data, as they carry the
1121 // same pointer from source to destination and back
1122 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA));
1124 if (p != getPtr<uint8_t>())
1125 // for packet with allocated dynamic data, we copy data from
1126 // one to the other, e.g. a forwarded response to a response
1127 std::memcpy(getPtr<uint8_t>(), p, getSize());
1131 * Copy data into the packet from the provided block pointer,
1132 * which is aligned to the given block size.
1135 setDataFromBlock(const uint8_t *blk_data, int blkSize)
1137 setData(blk_data + getOffset(blkSize));
1141 * Copy data from the packet to the memory at the provided pointer.
1142 * @param p Pointer to which data will be copied.
1145 writeData(uint8_t *p) const
1147 std::memcpy(p, getConstPtr<uint8_t>(), getSize());
1151 * Copy data from the packet to the provided block pointer, which
1152 * is aligned to the given block size.
1153 * @param blk_data Pointer to block to which data will be copied.
1154 * @param blkSize Block size in bytes.
1157 writeDataToBlock(uint8_t *blk_data, int blkSize) const
1159 writeData(blk_data + getOffset(blkSize));
1163 * delete the data pointed to in the data pointer. Ok to call to
1164 * matter how data was allocted.
1169 if (flags.isSet(DYNAMIC_DATA))
1172 flags.clear(STATIC_DATA|DYNAMIC_DATA);
1176 /** Allocate memory for the packet. */
1180 // if either this command or the response command has a data
1181 // payload, actually allocate space
1182 if (hasData() || hasRespData()) {
1183 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
1184 flags.set(DYNAMIC_DATA);
1185 data = new uint8_t[getSize()];
1191 /** Get the data in the packet without byte swapping. */
1192 template <typename T>
1195 /** Set the value in the data pointer to v without byte swapping. */
1196 template <typename T>
1201 * Check a functional request against a memory value stored in
1202 * another packet (i.e. an in-transit request or
1203 * response). Returns true if the current packet is a read, and
1204 * the other packet provides the data, which is then copied to the
1205 * current packet. If the current packet is a write, and the other
1206 * packet intersects this one, then we update the data
1210 trySatisfyFunctional(PacketPtr other)
1212 // all packets that are carrying a payload should have a valid
1214 return trySatisfyFunctional(other, other->getAddr(), other->isSecure(),
1217 other->getPtr<uint8_t>() : NULL);
1221 * Does the request need to check for cached copies of the same block
1222 * in the memory hierarchy above.
1225 mustCheckAbove() const
1227 return cmd == MemCmd::HardPFReq || isEviction();
1231 * Is this packet a clean eviction, including both actual clean
1232 * evict packets, but also clean writebacks.
1235 isCleanEviction() const
1237 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean;
1241 * Check a functional request against a memory value represented
1242 * by a base/size pair and an associated data array. If the
1243 * current packet is a read, it may be satisfied by the memory
1244 * value. If the current packet is a write, it may update the
1248 trySatisfyFunctional(Printable *obj, Addr base, bool is_secure, int size,
1252 * Push label for PrintReq (safe to call unconditionally).
1255 pushLabel(const std::string &lbl)
1258 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
1262 * Pop label for PrintReq (safe to call unconditionally).
1268 safe_cast<PrintReqState*>(senderState)->popLabel();
1271 void print(std::ostream &o, int verbosity = 0,
1272 const std::string &prefix = "") const;
1275 * A no-args wrapper of print(std::ostream...)
1276 * meant to be invoked from DPRINTFs
1277 * avoiding string overheads in fast mode
1278 * @return string with the request's type and start<->end addresses
1280 std::string print() const;
1283 #endif //__MEM_PACKET_HH