2 * Copyright (c) 2006 The Regents of The University of Michigan
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16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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28 * Authors: Ron Dreslinski
35 * Declaration of the Packet class.
38 #ifndef __MEM_PACKET_HH__
39 #define __MEM_PACKET_HH__
45 #include "base/compiler.hh"
46 #include "base/fast_alloc.hh"
47 #include "base/misc.hh"
48 #include "base/printable.hh"
49 #include "mem/request.hh"
50 #include "sim/host.hh"
51 #include "sim/core.hh"
55 typedef Packet *PacketPtr;
56 typedef uint8_t* PacketDataPtr;
57 typedef std::list<PacketPtr> PacketList;
63 /** List of all commands associated with a packet. */
89 // @TODO these should be classified as responses rather than
90 // requests; coding them as requests initially for backwards
92 NetworkNackError, // nacked at network layer (not by protocol)
93 InvalidDestError, // packet dest field invalid
94 BadAddressError, // memory address invalid
95 // Fake simulator-only commands
96 PrintReq, // Print state matching address
101 /** List of command attributes. */
104 IsRead, //!< Data flows from responder to requester
105 IsWrite, //!< Data flows from requester to responder
106 IsPrefetch, //!< Not a demand access
108 NeedsExclusive, //!< Requires exclusive copy to complete in-cache
109 IsRequest, //!< Issued by requester
110 IsResponse, //!< Issue by responder
111 NeedsResponse, //!< Requester needs response from target
114 IsLocked, //!< Alpha/MIPS LL or SC access
115 HasData, //!< There is an associated payload
116 IsError, //!< Error response
117 IsPrint, //!< Print state matching address (for debugging)
118 NUM_COMMAND_ATTRIBUTES
121 /** Structure that defines attributes and other data associated
124 /** Set of attribute flags. */
125 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
126 /** Corresponding response for requests; InvalidCmd if no
127 * response is applicable. */
128 const Command response;
129 /** String representation (for printing) */
130 const std::string str;
133 /** Array to map Command enum to associated info. */
134 static const CommandInfo commandInfo[];
140 bool testCmdAttrib(MemCmd::Attribute attrib) const {
141 return commandInfo[cmd].attributes[attrib] != 0;
146 bool isRead() const { return testCmdAttrib(IsRead); }
147 bool isWrite() const { return testCmdAttrib(IsWrite); }
148 bool isRequest() const { return testCmdAttrib(IsRequest); }
149 bool isResponse() const { return testCmdAttrib(IsResponse); }
150 bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); }
151 bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
152 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
153 bool hasData() const { return testCmdAttrib(HasData); }
154 bool isReadWrite() const { return isRead() && isWrite(); }
155 bool isLocked() const { return testCmdAttrib(IsLocked); }
156 bool isError() const { return testCmdAttrib(IsError); }
157 bool isPrint() const { return testCmdAttrib(IsPrint); }
159 const Command responseCommand() const {
160 return commandInfo[cmd].response;
163 /** Return the string to a cmd given by idx. */
164 const std::string &toString() const {
165 return commandInfo[cmd].str;
168 int toInt() const { return (int)cmd; }
182 bool operator==(MemCmd c2) { return (cmd == c2.cmd); }
183 bool operator!=(MemCmd c2) { return (cmd != c2.cmd); }
189 * A Packet is used to encapsulate a transfer between two objects in
190 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
191 * single Request travels all the way from the requester to the
192 * ultimate destination and back, possibly being conveyed by several
193 * different Packets along the way.)
195 class Packet : public FastAlloc, public Printable
199 typedef MemCmd::Command Command;
201 /** The command field of the packet. */
204 /** A pointer to the original request. */
208 /** A pointer to the data being transfered. It can be differnt
209 * sizes at each level of the heirarchy so it belongs in the
210 * packet, not request. This may or may not be populated when a
211 * responder recieves the packet. If not populated it memory
212 * should be allocated.
216 /** Is the data pointer set to a value that shouldn't be freed
217 * when the packet is destroyed? */
219 /** The data pointer points to a value that should be freed when
220 * the packet is destroyed. */
222 /** the data pointer points to an array (thus delete [] ) needs to
223 * be called on it rather than simply delete.*/
226 /** The address of the request. This address could be virtual or
227 * physical, depending on the system configuration. */
230 /** The size of the request or transfer. */
233 /** Device address (e.g., bus ID) of the source of the
234 * transaction. The source is not responsible for setting this
235 * field; it is set implicitly by the interconnect when the
236 * packet is first sent. */
239 /** Device address (e.g., bus ID) of the destination of the
240 * transaction. The special value Broadcast indicates that the
241 * packet should be routed based on its address. This field is
242 * initialized in the constructor and is thus always valid
243 * (unlike * addr, size, and src). */
246 /** The original value of the command field. Only valid when the
247 * current command field is an error condition; in that case, the
248 * previous contents of the command field are copied here. This
249 * field is *not* set on non-error responses.
253 /** Are the 'addr' and 'size' fields valid? */
255 /** Is the 'src' field valid? */
260 // Snoop response flags
263 // Special control flags
264 /// Special timing-mode atomic snoop for multi-level coherence.
266 /// Does supplier have exclusive copy?
267 /// Useful for multi-level coherence.
273 std::bitset<NUM_PACKET_FLAGS> flags;
277 /** Used to calculate latencies for each packet.*/
280 /** The time at which the packet will be fully transmitted */
283 /** The time at which the first chunk of the packet will be transmitted */
286 /** The special destination address indicating that the packet
287 * should be routed based on its address. */
288 static const short Broadcast = -1;
290 /** A virtual base opaque structure used to hold state associated
291 * with the packet but specific to the sending device (e.g., an
292 * MSHR). A pointer to this state is returned in the packet's
293 * response so that the sender can quickly look up the state
294 * needed to process it. A specific subclass would be derived
295 * from this to carry state specific to a particular sending
297 class SenderState : public FastAlloc {
299 virtual ~SenderState() {}
303 * Object used to maintain state of a PrintReq. The senderState
304 * field of a PrintReq should always be of this type.
306 class PrintReqState : public SenderState {
307 /** An entry in the label stack. */
308 class LabelStackEntry {
310 const std::string label;
313 LabelStackEntry(const std::string &_label,
314 std::string *_prefix);
317 typedef std::list<LabelStackEntry> LabelStack;
318 LabelStack labelStack;
320 std::string *curPrefixPtr;
326 PrintReqState(std::ostream &os, int verbosity = 0);
329 /** Returns the current line prefix. */
330 const std::string &curPrefix() { return *curPrefixPtr; }
332 /** Push a label onto the label stack, and prepend the given
333 * prefix string onto the current prefix. Labels will only be
334 * printed if an object within the label's scope is
336 void pushLabel(const std::string &lbl,
337 const std::string &prefix = " ");
338 /** Pop a label off the label stack. */
340 /** Print all of the pending unprinted labels on the
341 * stack. Called by printObj(), so normally not called by
342 * users unless bypassing printObj(). */
344 /** Print a Printable object to os, because it matched the
345 * address on a PrintReq. */
346 void printObj(Printable *obj);
349 /** This packet's sender state. Devices should use dynamic_cast<>
350 * to cast to the state appropriate to the sender. */
351 SenderState *senderState;
353 /** Return the string name of the cmd field (for debugging and
355 const std::string &cmdString() const { return cmd.toString(); }
357 /** Return the index of this command. */
358 inline int cmdToIndex() const { return cmd.toInt(); }
360 bool isRead() const { return cmd.isRead(); }
361 bool isWrite() const { return cmd.isWrite(); }
362 bool isRequest() const { return cmd.isRequest(); }
363 bool isResponse() const { return cmd.isResponse(); }
364 bool needsExclusive() const { return cmd.needsExclusive(); }
365 bool needsResponse() const { return cmd.needsResponse(); }
366 bool isInvalidate() const { return cmd.isInvalidate(); }
367 bool hasData() const { return cmd.hasData(); }
368 bool isReadWrite() const { return cmd.isReadWrite(); }
369 bool isLocked() const { return cmd.isLocked(); }
370 bool isError() const { return cmd.isError(); }
371 bool isPrint() const { return cmd.isPrint(); }
374 void assertMemInhibit() { flags[MemInhibit] = true; }
375 bool memInhibitAsserted() { return flags[MemInhibit]; }
376 void assertShared() { flags[Shared] = true; }
377 bool sharedAsserted() { return flags[Shared]; }
379 // Special control flags
380 void setExpressSnoop() { flags[ExpressSnoop] = true; }
381 bool isExpressSnoop() { return flags[ExpressSnoop]; }
382 void setSupplyExclusive() { flags[SupplyExclusive] = true; }
383 bool isSupplyExclusive() { return flags[SupplyExclusive]; }
385 // Network error conditions... encapsulate them as methods since
386 // their encoding keeps changing (from result field to command
388 void setNacked() { assert(isResponse()); cmd = MemCmd::NetworkNackError; }
389 void setBadAddress() { assert(isResponse()); cmd = MemCmd::BadAddressError; }
390 bool wasNacked() { return cmd == MemCmd::NetworkNackError; }
391 bool hadBadAddress() { return cmd == MemCmd::BadAddressError; }
392 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
394 bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN }
396 /** Accessor function that returns the source index of the packet. */
397 short getSrc() const { assert(srcValid); return src; }
398 void setSrc(short _src) { src = _src; srcValid = true; }
399 /** Reset source field, e.g. to retransmit packet on different bus. */
400 void clearSrc() { srcValid = false; }
402 /** Accessor function that returns the destination index of
404 short getDest() const { assert(destValid); return dest; }
405 void setDest(short _dest) { dest = _dest; destValid = true; }
407 Addr getAddr() const { assert(addrSizeValid); return addr; }
408 int getSize() const { assert(addrSizeValid); return size; }
409 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); }
411 /** Constructor. Note that a Request object must be constructed
412 * first, but the Requests's physical address and size fields
413 * need not be valid. The command and destination addresses
414 * must be supplied. */
415 Packet(Request *_req, MemCmd _cmd, short _dest)
416 : cmd(_cmd), req(_req),
417 data(NULL), staticData(false), dynamicData(false), arrayData(false),
418 addr(_req->paddr), size(_req->size), dest(_dest),
419 addrSizeValid(_req->validPaddr), srcValid(false), destValid(true),
420 flags(0), time(curTick), senderState(NULL)
424 /** Alternate constructor if you are trying to create a packet with
425 * a request that is for a whole block, not the address from the req.
426 * this allows for overriding the size/addr of the req.*/
427 Packet(Request *_req, MemCmd _cmd, short _dest, int _blkSize)
428 : cmd(_cmd), req(_req),
429 data(NULL), staticData(false), dynamicData(false), arrayData(false),
430 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), dest(_dest),
431 addrSizeValid(_req->validPaddr), srcValid(false), destValid(true),
432 flags(0), time(curTick), senderState(NULL)
436 /** Alternate constructor for copying a packet. Copy all fields
437 * *except* if the original packet's data was dynamic, don't copy
438 * that, as we can't guarantee that the new packet's lifetime is
439 * less than that of the original packet. In this case the new
440 * packet should allocate its own data. */
441 Packet(Packet *origPkt, bool clearFlags = false)
442 : cmd(origPkt->cmd), req(origPkt->req),
443 data(origPkt->staticData ? origPkt->data : NULL),
444 staticData(origPkt->staticData),
445 dynamicData(false), arrayData(false),
446 addr(origPkt->addr), size(origPkt->size),
447 src(origPkt->src), dest(origPkt->dest),
448 addrSizeValid(origPkt->addrSizeValid),
449 srcValid(origPkt->srcValid), destValid(origPkt->destValid),
450 flags(clearFlags ? 0 : origPkt->flags),
451 time(curTick), senderState(origPkt->senderState)
457 { if (staticData || dynamicData) deleteData(); }
459 /** Reinitialize packet address and size from the associated
460 * Request object, and reset other fields that may have been
461 * modified by a previous transaction. Typically called when a
462 * statically allocated Request/Packet pair is reused for
463 * multiple transactions. */
464 void reinitFromRequest() {
465 assert(req->validPaddr);
470 addrSizeValid = true;
479 * Take a request packet and modify it in place to be suitable for
480 * returning as a response to that request. The source and
481 * destination fields are *not* modified, as is appropriate for
486 assert(needsResponse());
489 cmd = cmd.responseCommand();
491 destValid = srcValid;
495 void makeAtomicResponse()
500 void makeTimingResponse()
506 * Take a request packet that has been returned as NACKED and
507 * modify it so that it can be sent out again. Only packets that
508 * need a response can be NACKED, so verify that that is true.
515 assert(needsResponse());
521 * Set the data pointer to the following value that should not be
524 template <typename T>
530 data = (PacketDataPtr)p;
535 * Set the data pointer to a value that should have delete []
538 template <typename T>
540 dataDynamicArray(T *p)
542 assert(!staticData && !dynamicData);
543 data = (PacketDataPtr)p;
549 * set the data pointer to a value that should have delete called
552 template <typename T>
556 assert(!staticData && !dynamicData);
557 data = (PacketDataPtr)p;
562 /** get a pointer to the data ptr. */
563 template <typename T>
567 assert(staticData || dynamicData);
571 /** return the value of what is pointed to in the packet. */
572 template <typename T>
575 /** set the value in the data pointer to v. */
576 template <typename T>
580 * Copy data into the packet from the provided pointer.
582 void setData(uint8_t *p)
584 std::memcpy(getPtr<uint8_t>(), p, getSize());
588 * Copy data into the packet from the provided block pointer,
589 * which is aligned to the given block size.
591 void setDataFromBlock(uint8_t *blk_data, int blkSize)
593 setData(blk_data + getOffset(blkSize));
597 * Copy data from the packet to the provided block pointer, which
598 * is aligned to the given block size.
600 void writeData(uint8_t *p)
602 std::memcpy(p, getPtr<uint8_t>(), getSize());
606 * Copy data from the packet to the memory at the provided pointer.
608 void writeDataToBlock(uint8_t *blk_data, int blkSize)
610 writeData(blk_data + getOffset(blkSize));
614 * delete the data pointed to in the data pointer. Ok to call to
615 * matter how data was allocted.
619 /** If there isn't data in the packet, allocate some. */
623 * Check a functional request against a memory value represented
624 * by a base/size pair and an associated data array. If the
625 * functional request is a read, it may be satisfied by the memory
626 * value. If the functional request is a write, it may update the
629 bool checkFunctional(Printable *obj, Addr base, int size, uint8_t *data);
632 * Check a functional request against a memory value stored in
633 * another packet (i.e. an in-transit request or response).
635 bool checkFunctional(PacketPtr otherPkt) {
636 return checkFunctional(otherPkt,
637 otherPkt->getAddr(), otherPkt->getSize(),
638 otherPkt->hasData() ?
639 otherPkt->getPtr<uint8_t>() : NULL);
643 * Push label for PrintReq (safe to call unconditionally).
645 void pushLabel(const std::string &lbl) {
647 dynamic_cast<PrintReqState*>(senderState)->pushLabel(lbl);
652 * Pop label for PrintReq (safe to call unconditionally).
656 dynamic_cast<PrintReqState*>(senderState)->popLabel();
660 void print(std::ostream &o, int verbosity = 0,
661 const std::string &prefix = "") const;
664 #endif //__MEM_PACKET_HH