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15 * Copyright (c) 2010 Advanced Micro Devices, Inc.
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29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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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/flags.hh"
62 #include "base/misc.hh"
63 #include "base/printable.hh"
64 #include "base/types.hh"
65 #include "mem/request.hh"
66 #include "sim/core.hh"
69 typedef Packet *PacketPtr;
70 typedef uint8_t* PacketDataPtr;
71 typedef std::list<PacketPtr> PacketList;
79 * List of all commands associated with a packet.
86 ReadRespWithInvalidate,
94 // WriteInvalidateReq transactions used to be generated by the
95 // DMA ports when writing full blocks to memory, however, it
96 // is not used anymore since we put the I/O cache in place to
97 // deal with partial block writes. Hence, WriteInvalidateReq
98 // and WriteInvalidateResp are currently unused. The
99 // implication is that the I/O cache does read-exclusive
100 // operations on every full-cache-block DMA, and ultimately
101 // this needs to be fixed.
105 SCUpgradeReq, // Special "weak" upgrade for StoreCond
107 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent)
108 UpgradeFailResp, // Valid for SCUpgradeReq only
113 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent)
120 // @TODO these should be classified as responses rather than
121 // requests; coding them as requests initially for backwards
123 InvalidDestError, // packet dest field invalid
124 BadAddressError, // memory address invalid
125 FunctionalReadError, // unable to fulfill functional read
126 FunctionalWriteError, // unable to fulfill functional write
127 // Fake simulator-only commands
128 PrintReq, // Print state matching address
129 FlushReq, //request for a cache flush
130 InvalidationReq, // request for address to be invalidated from lsq
136 * List of command attributes.
140 IsRead, //!< Data flows from responder to requester
141 IsWrite, //!< Data flows from requester to responder
144 NeedsExclusive, //!< Requires exclusive copy to complete in-cache
145 IsRequest, //!< Issued by requester
146 IsResponse, //!< Issue by responder
147 NeedsResponse, //!< Requester needs response from target
150 IsLlsc, //!< Alpha/MIPS LL or SC access
151 HasData, //!< There is an associated payload
152 IsError, //!< Error response
153 IsPrint, //!< Print state matching address (for debugging)
154 IsFlush, //!< Flush the address from caches
155 NUM_COMMAND_ATTRIBUTES
159 * Structure that defines attributes and other data associated
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;
173 /// Array to map Command enum to associated info.
174 static const CommandInfo commandInfo[];
181 testCmdAttrib(MemCmd::Attribute attrib) const
183 return commandInfo[cmd].attributes[attrib] != 0;
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 needsExclusive() const { return testCmdAttrib(NeedsExclusive); }
194 bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
195 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
196 bool hasData() const { return testCmdAttrib(HasData); }
197 bool isReadWrite() const { return isRead() && isWrite(); }
198 bool isLLSC() const { return testCmdAttrib(IsLlsc); }
199 bool isError() const { return testCmdAttrib(IsError); }
200 bool isPrint() const { return testCmdAttrib(IsPrint); }
201 bool isFlush() const { return testCmdAttrib(IsFlush); }
204 responseCommand() const
206 return commandInfo[cmd].response;
209 /// Return the string to a cmd given by idx.
210 const std::string &toString() const { return commandInfo[cmd].str; }
211 int toInt() const { return (int)cmd; }
213 MemCmd(Command _cmd) : cmd(_cmd) { }
214 MemCmd(int _cmd) : cmd((Command)_cmd) { }
215 MemCmd() : cmd(InvalidCmd) { }
217 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
218 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
222 * A Packet is used to encapsulate a transfer between two objects in
223 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
224 * single Request travels all the way from the requester to the
225 * ultimate destination and back, possibly being conveyed by several
226 * different Packets along the way.)
228 class Packet : public Printable
231 typedef uint32_t FlagsType;
232 typedef ::Flags<FlagsType> Flags;
235 static const FlagsType PUBLIC_FLAGS = 0x00000000;
236 static const FlagsType PRIVATE_FLAGS = 0x00007F0F;
237 static const FlagsType COPY_FLAGS = 0x0000000F;
239 static const FlagsType SHARED = 0x00000001;
240 // Special control flags
241 /// Special timing-mode atomic snoop for multi-level coherence.
242 static const FlagsType EXPRESS_SNOOP = 0x00000002;
243 /// Does supplier have exclusive copy?
244 /// Useful for multi-level coherence.
245 static const FlagsType SUPPLY_EXCLUSIVE = 0x00000004;
246 // Snoop response flags
247 static const FlagsType MEM_INHIBIT = 0x00000008;
248 /// Are the 'addr' and 'size' fields valid?
249 static const FlagsType VALID_ADDR = 0x00000100;
250 static const FlagsType VALID_SIZE = 0x00000200;
251 /// Is the data pointer set to a value that shouldn't be freed
252 /// when the packet is destroyed?
253 static const FlagsType STATIC_DATA = 0x00001000;
254 /// The data pointer points to a value that should be freed when
255 /// the packet is destroyed.
256 static const FlagsType DYNAMIC_DATA = 0x00002000;
257 /// the data pointer points to an array (thus delete []) needs to
258 /// be called on it rather than simply delete.
259 static const FlagsType ARRAY_DATA = 0x00004000;
260 /// suppress the error if this packet encounters a functional
262 static const FlagsType SUPPRESS_FUNC_ERROR = 0x00008000;
267 typedef MemCmd::Command Command;
269 /// The command field of the packet.
272 /// A pointer to the original request.
277 * A pointer to the data being transfered. It can be differnt
278 * sizes at each level of the heirarchy so it belongs in the
279 * packet, not request. This may or may not be populated when a
280 * responder recieves the packet. If not populated it memory should
285 /// The address of the request. This address could be virtual or
286 /// physical, depending on the system configuration.
289 /// The size of the request or transfer.
293 * Source port identifier set on a request packet to enable
294 * appropriate routing of the responses. The source port
295 * identifier is set by any multiplexing component, e.g. a bus, as
296 * the timing responses need this information to be routed back to
297 * the appropriate port at a later point in time. The field can be
298 * updated (over-written) as the request packet passes through
299 * additional multiplexing components, and it is their
300 * responsibility to remember the original source port identifier,
301 * for example by using an appropriate sender state. The latter is
302 * done in the cache and bridge.
307 * Destination port identifier that is present on all response
308 * packets that passed through a multiplexing component as a
309 * request packet. The source port identifier is turned into a
310 * destination port identifier when the packet is turned into a
311 * response, and the destination is used, e.g. by the bus, to
312 * select the appropriate path through the interconnect.
317 * The original value of the command field. Only valid when the
318 * current command field is an error condition; in that case, the
319 * previous contents of the command field are copied here. This
320 * field is *not* set on non-error responses.
325 * These values specify the range of bytes found that satisfy a
328 uint16_t bytesValidStart;
329 uint16_t bytesValidEnd;
332 /// Used to calculate latencies for each packet.
335 /// The time at which the packet will be fully transmitted
338 /// The time at which the first chunk of the packet will be transmitted
342 * A virtual base opaque structure used to hold state associated
343 * with the packet but specific to the sending device (e.g., an
344 * MSHR). A pointer to this state is returned in the packet's
345 * response so that the sender can quickly look up the state
346 * needed to process it. A specific subclass would be derived
347 * from this to carry state specific to a particular sending
352 virtual ~SenderState() {}
356 * Object used to maintain state of a PrintReq. The senderState
357 * field of a PrintReq should always be of this type.
359 class PrintReqState : public SenderState
363 * An entry in the label stack.
365 struct LabelStackEntry
367 const std::string label;
370 LabelStackEntry(const std::string &_label, std::string *_prefix);
373 typedef std::list<LabelStackEntry> LabelStack;
374 LabelStack labelStack;
376 std::string *curPrefixPtr;
382 PrintReqState(std::ostream &os, int verbosity = 0);
386 * Returns the current line prefix.
388 const std::string &curPrefix() { return *curPrefixPtr; }
391 * Push a label onto the label stack, and prepend the given
392 * prefix string onto the current prefix. Labels will only be
393 * printed if an object within the label's scope is printed.
395 void pushLabel(const std::string &lbl,
396 const std::string &prefix = " ");
399 * Pop a label off the label stack.
404 * Print all of the pending unprinted labels on the
405 * stack. Called by printObj(), so normally not called by
406 * users unless bypassing printObj().
411 * Print a Printable object to os, because it matched the
412 * address on a PrintReq.
414 void printObj(Printable *obj);
418 * This packet's sender state. Devices should use dynamic_cast<>
419 * to cast to the state appropriate to the sender. The intent of
420 * this variable is to allow a device to attach extra information
421 * to a request. A response packet must return the sender state
422 * that was attached to the original request (even if a new packet
425 SenderState *senderState;
427 /// Return the string name of the cmd field (for debugging and
429 const std::string &cmdString() const { return cmd.toString(); }
431 /// Return the index of this command.
432 inline int cmdToIndex() const { return cmd.toInt(); }
434 bool isRead() const { return cmd.isRead(); }
435 bool isWrite() const { return cmd.isWrite(); }
436 bool isUpgrade() const { return cmd.isUpgrade(); }
437 bool isRequest() const { return cmd.isRequest(); }
438 bool isResponse() const { return cmd.isResponse(); }
439 bool needsExclusive() const { return cmd.needsExclusive(); }
440 bool needsResponse() const { return cmd.needsResponse(); }
441 bool isInvalidate() const { return cmd.isInvalidate(); }
442 bool hasData() const { return cmd.hasData(); }
443 bool isReadWrite() const { return cmd.isReadWrite(); }
444 bool isLLSC() const { return cmd.isLLSC(); }
445 bool isError() const { return cmd.isError(); }
446 bool isPrint() const { return cmd.isPrint(); }
447 bool isFlush() const { return cmd.isFlush(); }
450 void assertMemInhibit() { flags.set(MEM_INHIBIT); }
451 bool memInhibitAsserted() { return flags.isSet(MEM_INHIBIT); }
452 void assertShared() { flags.set(SHARED); }
453 bool sharedAsserted() { return flags.isSet(SHARED); }
455 // Special control flags
456 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); }
457 bool isExpressSnoop() { return flags.isSet(EXPRESS_SNOOP); }
458 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); }
459 void clearSupplyExclusive() { flags.clear(SUPPLY_EXCLUSIVE); }
460 bool isSupplyExclusive() { return flags.isSet(SUPPLY_EXCLUSIVE); }
461 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); }
462 bool suppressFuncError() { return flags.isSet(SUPPRESS_FUNC_ERROR); }
464 // Network error conditions... encapsulate them as methods since
465 // their encoding keeps changing (from result field to command
470 assert(isResponse());
471 cmd = MemCmd::BadAddressError;
474 bool hadBadAddress() const { return cmd == MemCmd::BadAddressError; }
475 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
477 bool isSrcValid() const { return src != InvalidPortID; }
478 /// Accessor function to get the source index of the packet.
479 PortID getSrc() const { assert(isSrcValid()); return src; }
480 /// Accessor function to set the source index of the packet.
481 void setSrc(PortID _src) { src = _src; }
482 /// Reset source field, e.g. to retransmit packet on different bus.
483 void clearSrc() { src = InvalidPortID; }
485 bool isDestValid() const { return dest != InvalidPortID; }
486 /// Accessor function for the destination index of the packet.
487 PortID getDest() const { assert(isDestValid()); return dest; }
488 /// Accessor function to set the destination index of the packet.
489 void setDest(PortID _dest) { dest = _dest; }
490 /// Reset destination field, e.g. to turn a response into a request again.
491 void clearDest() { dest = InvalidPortID; }
493 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
495 * Update the address of this packet mid-transaction. This is used
496 * by the address mapper to change an already set address to a new
497 * one based on the system configuration. It is intended to remap
498 * an existing address, so it asserts that the current address is
501 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; }
503 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; }
504 Addr getOffset(int blkSize) const { return getAddr() & (Addr)(blkSize - 1); }
507 * It has been determined that the SC packet should successfully update
508 * memory. Therefore, convert this SC packet to a normal write.
515 cmd = MemCmd::WriteReq;
519 * When ruby is in use, Ruby will monitor the cache line and thus M5
520 * phys memory should treat LL ops as normal reads.
527 cmd = MemCmd::ReadReq;
531 * Constructor. Note that a Request object must be constructed
532 * first, but the Requests's physical address and size fields need
533 * not be valid. The command must be supplied.
535 Packet(Request *_req, MemCmd _cmd)
536 : cmd(_cmd), req(_req), data(NULL),
537 src(InvalidPortID), dest(InvalidPortID),
538 bytesValidStart(0), bytesValidEnd(0),
539 time(curTick()), senderState(NULL)
541 if (req->hasPaddr()) {
542 addr = req->getPaddr();
543 flags.set(VALID_ADDR);
545 if (req->hasSize()) {
546 size = req->getSize();
547 flags.set(VALID_SIZE);
552 * Alternate constructor if you are trying to create a packet with
553 * a request that is for a whole block, not the address from the
554 * req. this allows for overriding the size/addr of the req.
556 Packet(Request *_req, MemCmd _cmd, int _blkSize)
557 : cmd(_cmd), req(_req), data(NULL),
558 src(InvalidPortID), dest(InvalidPortID),
559 bytesValidStart(0), bytesValidEnd(0),
560 time(curTick()), senderState(NULL)
562 if (req->hasPaddr()) {
563 addr = req->getPaddr() & ~(_blkSize - 1);
564 flags.set(VALID_ADDR);
567 flags.set(VALID_SIZE);
571 * Alternate constructor for copying a packet. Copy all fields
572 * *except* if the original packet's data was dynamic, don't copy
573 * that, as we can't guarantee that the new packet's lifetime is
574 * less than that of the original packet. In this case the new
575 * packet should allocate its own data.
577 Packet(Packet *pkt, bool clearFlags = false)
578 : cmd(pkt->cmd), req(pkt->req),
579 data(pkt->flags.isSet(STATIC_DATA) ? pkt->data : NULL),
580 addr(pkt->addr), size(pkt->size), src(pkt->src), dest(pkt->dest),
581 bytesValidStart(pkt->bytesValidStart), bytesValidEnd(pkt->bytesValidEnd),
582 time(curTick()), senderState(pkt->senderState)
585 flags.set(pkt->flags & COPY_FLAGS);
587 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE));
588 flags.set(pkt->flags & STATIC_DATA);
593 * clean up packet variables
597 // If this is a request packet for which there's no response,
598 // delete the request object here, since the requester will
599 // never get the chance.
600 if (req && isRequest() && !needsResponse())
606 * Reinitialize packet address and size from the associated
607 * Request object, and reset other fields that may have been
608 * modified by a previous transaction. Typically called when a
609 * statically allocated Request/Packet pair is reused for multiple
615 assert(req->hasPaddr());
617 addr = req->getPaddr();
618 size = req->getSize();
621 flags.set(VALID_ADDR|VALID_SIZE);
626 * Take a request packet and modify it in place to be suitable for
627 * returning as a response to that request. The source field is
628 * turned into the destination, and subsequently cleared. Note
629 * that the latter is not necessary for atomic requests, but
630 * causes no harm as neither field is valid.
635 assert(needsResponse());
638 cmd = cmd.responseCommand();
640 // responses are never express, even if the snoop that
641 // triggered them was
642 flags.clear(EXPRESS_SNOOP);
661 setFunctionalResponseStatus(bool success)
665 cmd = MemCmd::FunctionalWriteError;
667 cmd = MemCmd::FunctionalReadError;
673 setSize(unsigned size)
675 assert(!flags.isSet(VALID_SIZE));
678 flags.set(VALID_SIZE);
683 * Set the data pointer to the following value that should not be
686 template <typename T>
690 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
691 data = (PacketDataPtr)p;
692 flags.set(STATIC_DATA);
696 * Set the data pointer to a value that should have delete []
699 template <typename T>
701 dataDynamicArray(T *p)
703 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
704 data = (PacketDataPtr)p;
705 flags.set(DYNAMIC_DATA|ARRAY_DATA);
709 * set the data pointer to a value that should have delete called
712 template <typename T>
716 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA));
717 data = (PacketDataPtr)p;
718 flags.set(DYNAMIC_DATA);
722 * get a pointer to the data ptr.
724 template <typename T>
726 getPtr(bool null_ok = false)
728 assert(null_ok || flags.isSet(STATIC_DATA|DYNAMIC_DATA));
733 * return the value of what is pointed to in the packet.
735 template <typename T>
739 * set the value in the data pointer to v.
741 template <typename T>
745 * Copy data into the packet from the provided pointer.
750 if (p != getPtr<uint8_t>())
751 std::memcpy(getPtr<uint8_t>(), p, getSize());
755 * Copy data into the packet from the provided block pointer,
756 * which is aligned to the given block size.
759 setDataFromBlock(uint8_t *blk_data, int blkSize)
761 setData(blk_data + getOffset(blkSize));
765 * Copy data from the packet to the provided block pointer, which
766 * is aligned to the given block size.
769 writeData(uint8_t *p)
771 std::memcpy(p, getPtr<uint8_t>(), getSize());
775 * Copy data from the packet to the memory at the provided pointer.
778 writeDataToBlock(uint8_t *blk_data, int blkSize)
780 writeData(blk_data + getOffset(blkSize));
784 * delete the data pointed to in the data pointer. Ok to call to
785 * matter how data was allocted.
790 if (flags.isSet(ARRAY_DATA))
792 else if (flags.isSet(DYNAMIC_DATA))
795 flags.clear(STATIC_DATA|DYNAMIC_DATA|ARRAY_DATA);
799 /** If there isn't data in the packet, allocate some. */
804 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
808 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
809 flags.set(DYNAMIC_DATA|ARRAY_DATA);
810 data = new uint8_t[getSize()];
814 * Check a functional request against a memory value represented
815 * by a base/size pair and an associated data array. If the
816 * functional request is a read, it may be satisfied by the memory
817 * value. If the functional request is a write, it may update the
820 bool checkFunctional(Printable *obj, Addr base, int size, uint8_t *data);
823 * Check a functional request against a memory value stored in
824 * another packet (i.e. an in-transit request or response).
827 checkFunctional(PacketPtr other)
829 uint8_t *data = other->hasData() ? other->getPtr<uint8_t>() : NULL;
830 return checkFunctional(other, other->getAddr(), other->getSize(),
835 * Push label for PrintReq (safe to call unconditionally).
838 pushLabel(const std::string &lbl)
841 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
845 * Pop label for PrintReq (safe to call unconditionally).
851 safe_cast<PrintReqState*>(senderState)->popLabel();
854 void print(std::ostream &o, int verbosity = 0,
855 const std::string &prefix = "") const;
858 #endif //__MEM_PACKET_HH