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14 * Copyright (c) 2006 The Regents of The University of Michigan
15 * Copyright (c) 2010 Advanced Micro Devices, Inc.
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19 * modification, are permitted provided that the following conditions are
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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
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34 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
35 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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39 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41 * Authors: Ron Dreslinski
49 * Declaration of the Packet class.
52 #ifndef __MEM_PACKET_HH__
53 #define __MEM_PACKET_HH__
59 #include "base/cast.hh"
60 #include "base/compiler.hh"
61 #include "base/fast_alloc.hh"
62 #include "base/flags.hh"
63 #include "base/misc.hh"
64 #include "base/printable.hh"
65 #include "base/types.hh"
66 #include "mem/request.hh"
67 #include "sim/core.hh"
70 typedef Packet *PacketPtr;
71 typedef uint8_t* PacketDataPtr;
72 typedef std::list<PacketPtr> PacketList;
80 * List of all commands associated with a packet.
87 ReadRespWithInvalidate,
95 // WriteInvalidateReq transactions used to be generated by the
96 // DMA ports when writing full blocks to memory, however, it
97 // is not used anymore since we put the I/O cache in place to
98 // deal with partial block writes. Hence, WriteInvalidateReq
99 // and WriteInvalidateResp are currently unused. The
100 // implication is that the I/O cache does read-exclusive
101 // operations on every full-cache-block DMA, and ultimately
102 // this needs to be fixed.
106 SCUpgradeReq, // Special "weak" upgrade for StoreCond
108 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent)
109 UpgradeFailResp, // Valid for SCUpgradeReq only
114 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent)
121 // @TODO these should be classified as responses rather than
122 // requests; coding them as requests initially for backwards
124 NetworkNackError, // nacked at network layer (not by protocol)
125 InvalidDestError, // packet dest field invalid
126 BadAddressError, // memory address invalid
127 FunctionalReadError, // unable to fulfill functional read
128 FunctionalWriteError, // unable to fulfill functional write
129 // Fake simulator-only commands
130 PrintReq, // Print state matching address
131 FlushReq, //request for a cache flush
132 InvalidationReq, // request for address to be invalidated from lsq
138 * List of command attributes.
142 IsRead, //!< Data flows from responder to requester
143 IsWrite, //!< Data flows from requester to responder
146 NeedsExclusive, //!< Requires exclusive copy to complete in-cache
147 IsRequest, //!< Issued by requester
148 IsResponse, //!< Issue by responder
149 NeedsResponse, //!< Requester needs response from target
152 IsLlsc, //!< Alpha/MIPS LL or SC access
153 HasData, //!< There is an associated payload
154 IsError, //!< Error response
155 IsPrint, //!< Print state matching address (for debugging)
156 IsFlush, //!< Flush the address from caches
157 NUM_COMMAND_ATTRIBUTES
161 * Structure that defines attributes and other data associated
166 /// Set of attribute flags.
167 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
168 /// Corresponding response for requests; InvalidCmd if no
169 /// response is applicable.
170 const Command response;
171 /// String representation (for printing)
172 const std::string str;
175 /// Array to map Command enum to associated info.
176 static const CommandInfo commandInfo[];
183 testCmdAttrib(MemCmd::Attribute attrib) const
185 return commandInfo[cmd].attributes[attrib] != 0;
190 bool isRead() const { return testCmdAttrib(IsRead); }
191 bool isWrite() const { return testCmdAttrib(IsWrite); }
192 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); }
193 bool isRequest() const { return testCmdAttrib(IsRequest); }
194 bool isResponse() const { return testCmdAttrib(IsResponse); }
195 bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); }
196 bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
197 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
198 bool hasData() const { return testCmdAttrib(HasData); }
199 bool isReadWrite() const { return isRead() && isWrite(); }
200 bool isLLSC() const { return testCmdAttrib(IsLlsc); }
201 bool isError() const { return testCmdAttrib(IsError); }
202 bool isPrint() const { return testCmdAttrib(IsPrint); }
203 bool isFlush() const { return testCmdAttrib(IsFlush); }
206 responseCommand() const
208 return commandInfo[cmd].response;
211 /// Return the string to a cmd given by idx.
212 const std::string &toString() const { return commandInfo[cmd].str; }
213 int toInt() const { return (int)cmd; }
215 MemCmd(Command _cmd) : cmd(_cmd) { }
216 MemCmd(int _cmd) : cmd((Command)_cmd) { }
217 MemCmd() : cmd(InvalidCmd) { }
219 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
220 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
224 * A Packet is used to encapsulate a transfer between two objects in
225 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
226 * single Request travels all the way from the requester to the
227 * ultimate destination and back, possibly being conveyed by several
228 * different Packets along the way.)
230 class Packet : public FastAlloc, public Printable
233 typedef uint32_t FlagsType;
234 typedef ::Flags<FlagsType> Flags;
237 static const FlagsType PUBLIC_FLAGS = 0x00000000;
238 static const FlagsType PRIVATE_FLAGS = 0x00007F0F;
239 static const FlagsType COPY_FLAGS = 0x0000000F;
241 static const FlagsType SHARED = 0x00000001;
242 // Special control flags
243 /// Special timing-mode atomic snoop for multi-level coherence.
244 static const FlagsType EXPRESS_SNOOP = 0x00000002;
245 /// Does supplier have exclusive copy?
246 /// Useful for multi-level coherence.
247 static const FlagsType SUPPLY_EXCLUSIVE = 0x00000004;
248 // Snoop response flags
249 static const FlagsType MEM_INHIBIT = 0x00000008;
250 /// Are the 'addr' and 'size' fields valid?
251 static const FlagsType VALID_ADDR = 0x00000100;
252 static const FlagsType VALID_SIZE = 0x00000200;
253 /// Is the data pointer set to a value that shouldn't be freed
254 /// when the packet is destroyed?
255 static const FlagsType STATIC_DATA = 0x00001000;
256 /// The data pointer points to a value that should be freed when
257 /// the packet is destroyed.
258 static const FlagsType DYNAMIC_DATA = 0x00002000;
259 /// the data pointer points to an array (thus delete []) needs to
260 /// be called on it rather than simply delete.
261 static const FlagsType ARRAY_DATA = 0x00004000;
262 /// suppress the error if this packet encounters a functional
264 static const FlagsType SUPPRESS_FUNC_ERROR = 0x00008000;
269 typedef MemCmd::Command Command;
271 /// The command field of the packet.
274 /// A pointer to the original request.
279 * A pointer to the data being transfered. It can be differnt
280 * sizes at each level of the heirarchy so it belongs in the
281 * packet, not request. This may or may not be populated when a
282 * responder recieves the packet. If not populated it memory should
287 /// The address of the request. This address could be virtual or
288 /// physical, depending on the system configuration.
291 /// The size of the request or transfer.
295 * Source port identifier set on a request packet to enable
296 * appropriate routing of the responses. The source port
297 * identifier is set by any multiplexing component, e.g. a bus, as
298 * the timing responses need this information to be routed back to
299 * the appropriate port at a later point in time. The field can be
300 * updated (over-written) as the request packet passes through
301 * additional multiplexing components, and it is their
302 * responsibility to remember the original source port identifier,
303 * for example by using an appropriate sender state. The latter is
304 * done in the cache and bridge.
309 * Destination port identifier that is present on all response
310 * packets that passed through a multiplexing component as a
311 * request packet. The source port identifier is turned into a
312 * destination port identifier when the packet is turned into a
313 * response, and the destination is used, e.g. by the bus, to
314 * select the appropriate path through the interconnect.
319 * The original value of the command field. Only valid when the
320 * current command field is an error condition; in that case, the
321 * previous contents of the command field are copied here. This
322 * field is *not* set on non-error responses.
327 * These values specify the range of bytes found that satisfy a
330 uint16_t bytesValidStart;
331 uint16_t bytesValidEnd;
334 /// Used to calculate latencies for each packet.
337 /// The time at which the packet will be fully transmitted
340 /// The time at which the first chunk of the packet will be transmitted
344 * A virtual base opaque structure used to hold state associated
345 * with the packet but specific to the sending device (e.g., an
346 * MSHR). A pointer to this state is returned in the packet's
347 * response so that the sender can quickly look up the state
348 * needed to process it. A specific subclass would be derived
349 * from this to carry state specific to a particular sending
354 virtual ~SenderState() {}
358 * Object used to maintain state of a PrintReq. The senderState
359 * field of a PrintReq should always be of this type.
361 class PrintReqState : public SenderState, public FastAlloc
365 * An entry in the label stack.
367 struct LabelStackEntry
369 const std::string label;
372 LabelStackEntry(const std::string &_label, std::string *_prefix);
375 typedef std::list<LabelStackEntry> LabelStack;
376 LabelStack labelStack;
378 std::string *curPrefixPtr;
384 PrintReqState(std::ostream &os, int verbosity = 0);
388 * Returns the current line prefix.
390 const std::string &curPrefix() { return *curPrefixPtr; }
393 * Push a label onto the label stack, and prepend the given
394 * prefix string onto the current prefix. Labels will only be
395 * printed if an object within the label's scope is printed.
397 void pushLabel(const std::string &lbl,
398 const std::string &prefix = " ");
401 * Pop a label off the label stack.
406 * Print all of the pending unprinted labels on the
407 * stack. Called by printObj(), so normally not called by
408 * users unless bypassing printObj().
413 * Print a Printable object to os, because it matched the
414 * address on a PrintReq.
416 void printObj(Printable *obj);
420 * This packet's sender state. Devices should use dynamic_cast<>
421 * to cast to the state appropriate to the sender. The intent of
422 * this variable is to allow a device to attach extra information
423 * to a request. A response packet must return the sender state
424 * that was attached to the original request (even if a new packet
427 SenderState *senderState;
429 /// Return the string name of the cmd field (for debugging and
431 const std::string &cmdString() const { return cmd.toString(); }
433 /// Return the index of this command.
434 inline int cmdToIndex() const { return cmd.toInt(); }
436 bool isRead() const { return cmd.isRead(); }
437 bool isWrite() const { return cmd.isWrite(); }
438 bool isUpgrade() const { return cmd.isUpgrade(); }
439 bool isRequest() const { return cmd.isRequest(); }
440 bool isResponse() const { return cmd.isResponse(); }
441 bool needsExclusive() const { return cmd.needsExclusive(); }
442 bool needsResponse() const { return cmd.needsResponse(); }
443 bool isInvalidate() const { return cmd.isInvalidate(); }
444 bool hasData() const { return cmd.hasData(); }
445 bool isReadWrite() const { return cmd.isReadWrite(); }
446 bool isLLSC() const { return cmd.isLLSC(); }
447 bool isError() const { return cmd.isError(); }
448 bool isPrint() const { return cmd.isPrint(); }
449 bool isFlush() const { return cmd.isFlush(); }
452 void assertMemInhibit() { flags.set(MEM_INHIBIT); }
453 bool memInhibitAsserted() { return flags.isSet(MEM_INHIBIT); }
454 void assertShared() { flags.set(SHARED); }
455 bool sharedAsserted() { return flags.isSet(SHARED); }
457 // Special control flags
458 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); }
459 bool isExpressSnoop() { return flags.isSet(EXPRESS_SNOOP); }
460 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); }
461 void clearSupplyExclusive() { flags.clear(SUPPLY_EXCLUSIVE); }
462 bool isSupplyExclusive() { return flags.isSet(SUPPLY_EXCLUSIVE); }
463 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); }
464 bool suppressFuncError() { return flags.isSet(SUPPRESS_FUNC_ERROR); }
466 // Network error conditions... encapsulate them as methods since
467 // their encoding keeps changing (from result field to command
472 assert(isResponse());
473 cmd = MemCmd::NetworkNackError;
479 assert(isResponse());
480 cmd = MemCmd::BadAddressError;
483 bool wasNacked() const { return cmd == MemCmd::NetworkNackError; }
484 bool hadBadAddress() const { return cmd == MemCmd::BadAddressError; }
485 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
487 bool isSrcValid() const { return src != InvalidPortID; }
488 /// Accessor function to get the source index of the packet.
489 PortID getSrc() const { assert(isSrcValid()); return src; }
490 /// Accessor function to set the source index of the packet.
491 void setSrc(PortID _src) { src = _src; }
492 /// Reset source field, e.g. to retransmit packet on different bus.
493 void clearSrc() { src = InvalidPortID; }
495 bool isDestValid() const { return dest != InvalidPortID; }
496 /// Accessor function for the destination index of the packet.
497 PortID getDest() const { assert(isDestValid()); return dest; }
498 /// Accessor function to set the destination index of the packet.
499 void setDest(PortID _dest) { dest = _dest; }
500 /// Reset destination field, e.g. to turn a response into a request again.
501 void clearDest() { dest = InvalidPortID; }
503 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
504 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; }
505 Addr getOffset(int blkSize) const { return getAddr() & (Addr)(blkSize - 1); }
508 * It has been determined that the SC packet should successfully update
509 * memory. Therefore, convert this SC packet to a normal write.
516 cmd = MemCmd::WriteReq;
520 * When ruby is in use, Ruby will monitor the cache line and thus M5
521 * phys memory should treat LL ops as normal reads.
528 cmd = MemCmd::ReadReq;
532 * Constructor. Note that a Request object must be constructed
533 * first, but the Requests's physical address and size fields need
534 * not be valid. The command must be supplied.
536 Packet(Request *_req, MemCmd _cmd)
537 : cmd(_cmd), req(_req), data(NULL),
538 src(InvalidPortID), dest(InvalidPortID),
539 bytesValidStart(0), bytesValidEnd(0),
540 time(curTick()), senderState(NULL)
542 if (req->hasPaddr()) {
543 addr = req->getPaddr();
544 flags.set(VALID_ADDR);
546 if (req->hasSize()) {
547 size = req->getSize();
548 flags.set(VALID_SIZE);
553 * Alternate constructor if you are trying to create a packet with
554 * a request that is for a whole block, not the address from the
555 * req. this allows for overriding the size/addr of the req.
557 Packet(Request *_req, MemCmd _cmd, int _blkSize)
558 : cmd(_cmd), req(_req), data(NULL),
559 src(InvalidPortID), dest(InvalidPortID),
560 bytesValidStart(0), bytesValidEnd(0),
561 time(curTick()), senderState(NULL)
563 if (req->hasPaddr()) {
564 addr = req->getPaddr() & ~(_blkSize - 1);
565 flags.set(VALID_ADDR);
568 flags.set(VALID_SIZE);
572 * Alternate constructor for copying a packet. Copy all fields
573 * *except* if the original packet's data was dynamic, don't copy
574 * that, as we can't guarantee that the new packet's lifetime is
575 * less than that of the original packet. In this case the new
576 * packet should allocate its own data.
578 Packet(Packet *pkt, bool clearFlags = false)
579 : cmd(pkt->cmd), req(pkt->req),
580 data(pkt->flags.isSet(STATIC_DATA) ? pkt->data : NULL),
581 addr(pkt->addr), size(pkt->size), src(pkt->src), dest(pkt->dest),
582 bytesValidStart(pkt->bytesValidStart), bytesValidEnd(pkt->bytesValidEnd),
583 time(curTick()), senderState(pkt->senderState)
586 flags.set(pkt->flags & COPY_FLAGS);
588 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE));
589 flags.set(pkt->flags & STATIC_DATA);
594 * clean up packet variables
598 // If this is a request packet for which there's no response,
599 // delete the request object here, since the requester will
600 // never get the chance.
601 if (req && isRequest() && !needsResponse())
607 * Reinitialize packet address and size from the associated
608 * Request object, and reset other fields that may have been
609 * modified by a previous transaction. Typically called when a
610 * statically allocated Request/Packet pair is reused for multiple
616 assert(req->hasPaddr());
618 addr = req->getPaddr();
619 size = req->getSize();
622 flags.set(VALID_ADDR|VALID_SIZE);
627 * Take a request packet and modify it in place to be suitable for
628 * returning as a response to that request. The source field is
629 * turned into the destination, and subsequently cleared. Note
630 * that the latter is not necessary for atomic requests, but
631 * causes no harm as neither field is valid.
636 assert(needsResponse());
639 cmd = cmd.responseCommand();
641 // responses are never express, even if the snoop that
642 // triggered them was
643 flags.clear(EXPRESS_SNOOP);
662 setFunctionalResponseStatus(bool success)
666 cmd = MemCmd::FunctionalWriteError;
668 cmd = MemCmd::FunctionalReadError;
674 * Take a request packet that has been returned as NACKED and
675 * modify it so that it can be sent out again. Only packets that
676 * need a response can be NACKED, so verify that that is true.
683 assert(needsResponse());
688 setSize(unsigned size)
690 assert(!flags.isSet(VALID_SIZE));
693 flags.set(VALID_SIZE);
698 * Set the data pointer to the following value that should not be
701 template <typename T>
705 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
706 data = (PacketDataPtr)p;
707 flags.set(STATIC_DATA);
711 * Set the data pointer to a value that should have delete []
714 template <typename T>
716 dataDynamicArray(T *p)
718 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
719 data = (PacketDataPtr)p;
720 flags.set(DYNAMIC_DATA|ARRAY_DATA);
724 * set the data pointer to a value that should have delete called
727 template <typename T>
731 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
732 data = (PacketDataPtr)p;
733 flags.set(DYNAMIC_DATA);
737 * get a pointer to the data ptr.
739 template <typename T>
741 getPtr(bool null_ok = false)
743 assert(null_ok || flags.isSet(STATIC_DATA|DYNAMIC_DATA));
748 * return the value of what is pointed to in the packet.
750 template <typename T>
754 * set the value in the data pointer to v.
756 template <typename T>
760 * Copy data into the packet from the provided pointer.
765 if (p != getPtr<uint8_t>())
766 std::memcpy(getPtr<uint8_t>(), p, getSize());
770 * Copy data into the packet from the provided block pointer,
771 * which is aligned to the given block size.
774 setDataFromBlock(uint8_t *blk_data, int blkSize)
776 setData(blk_data + getOffset(blkSize));
780 * Copy data from the packet to the provided block pointer, which
781 * is aligned to the given block size.
784 writeData(uint8_t *p)
786 std::memcpy(p, getPtr<uint8_t>(), getSize());
790 * Copy data from the packet to the memory at the provided pointer.
793 writeDataToBlock(uint8_t *blk_data, int blkSize)
795 writeData(blk_data + getOffset(blkSize));
799 * delete the data pointed to in the data pointer. Ok to call to
800 * matter how data was allocted.
805 if (flags.isSet(ARRAY_DATA))
807 else if (flags.isSet(DYNAMIC_DATA))
810 flags.clear(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA);
814 /** If there isn't data in the packet, allocate some. */
819 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
823 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
824 flags.set(DYNAMIC_DATA|ARRAY_DATA);
825 data = new uint8_t[getSize()];
829 * Check a functional request against a memory value represented
830 * by a base/size pair and an associated data array. If the
831 * functional request is a read, it may be satisfied by the memory
832 * value. If the functional request is a write, it may update the
835 bool checkFunctional(Printable *obj, Addr base, int size, uint8_t *data);
838 * Check a functional request against a memory value stored in
839 * another packet (i.e. an in-transit request or response).
842 checkFunctional(PacketPtr other)
844 uint8_t *data = other->hasData() ? other->getPtr<uint8_t>() : NULL;
845 return checkFunctional(other, other->getAddr(), other->getSize(),
850 * Push label for PrintReq (safe to call unconditionally).
853 pushLabel(const std::string &lbl)
856 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
860 * Pop label for PrintReq (safe to call unconditionally).
866 safe_cast<PrintReqState*>(senderState)->popLabel();
869 void print(std::ostream &o, int verbosity = 0,
870 const std::string &prefix = "") const;
873 #endif //__MEM_PACKET_HH