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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19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 "mem/request.hh"
49 #include "sim/host.hh"
50 #include "sim/core.hh"
54 typedef Packet *PacketPtr;
55 typedef uint8_t* PacketDataPtr;
56 typedef std::list<PacketPtr> PacketList;
62 /** List of all commands associated with a packet. */
88 // @TODO these should be classified as responses rather than
89 // requests; coding them as requests initially for backwards
91 NetworkNackError, // nacked at network layer (not by protocol)
92 InvalidDestError, // packet dest field invalid
93 BadAddressError, // memory address invalid
98 /** List of command attributes. */
101 IsRead, //!< Data flows from responder to requester
102 IsWrite, //!< Data flows from requester to responder
103 IsPrefetch, //!< Not a demand access
105 NeedsExclusive, //!< Requires exclusive copy to complete in-cache
106 IsRequest, //!< Issued by requester
107 IsResponse, //!< Issue by responder
108 NeedsResponse, //!< Requester needs response from target
111 IsLocked, //!< Alpha/MIPS LL or SC access
112 HasData, //!< There is an associated payload
113 IsError, //!< Error response
114 NUM_COMMAND_ATTRIBUTES
117 /** Structure that defines attributes and other data associated
120 /** Set of attribute flags. */
121 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
122 /** Corresponding response for requests; InvalidCmd if no
123 * response is applicable. */
124 const Command response;
125 /** String representation (for printing) */
126 const std::string str;
129 /** Array to map Command enum to associated info. */
130 static const CommandInfo commandInfo[];
136 bool testCmdAttrib(MemCmd::Attribute attrib) const {
137 return commandInfo[cmd].attributes[attrib] != 0;
142 bool isRead() const { return testCmdAttrib(IsRead); }
143 bool isWrite() const { return testCmdAttrib(IsWrite); }
144 bool isRequest() const { return testCmdAttrib(IsRequest); }
145 bool isResponse() const { return testCmdAttrib(IsResponse); }
146 bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); }
147 bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
148 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
149 bool hasData() const { return testCmdAttrib(HasData); }
150 bool isReadWrite() const { return isRead() && isWrite(); }
151 bool isLocked() const { return testCmdAttrib(IsLocked); }
152 bool isError() const { return testCmdAttrib(IsError); }
154 const Command responseCommand() const {
155 return commandInfo[cmd].response;
158 /** Return the string to a cmd given by idx. */
159 const std::string &toString() const {
160 return commandInfo[cmd].str;
163 int toInt() const { return (int)cmd; }
177 bool operator==(MemCmd c2) { return (cmd == c2.cmd); }
178 bool operator!=(MemCmd c2) { return (cmd != c2.cmd); }
184 * A Packet is used to encapsulate a transfer between two objects in
185 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
186 * single Request travels all the way from the requester to the
187 * ultimate destination and back, possibly being conveyed by several
188 * different Packets along the way.)
190 class Packet : public FastAlloc
194 typedef MemCmd::Command Command;
196 /** The command field of the packet. */
199 /** A pointer to the original request. */
203 /** A pointer to the data being transfered. It can be differnt
204 * sizes at each level of the heirarchy so it belongs in the
205 * packet, not request. This may or may not be populated when a
206 * responder recieves the packet. If not populated it memory
207 * should be allocated.
211 /** Is the data pointer set to a value that shouldn't be freed
212 * when the packet is destroyed? */
214 /** The data pointer points to a value that should be freed when
215 * the packet is destroyed. */
217 /** the data pointer points to an array (thus delete [] ) needs to
218 * be called on it rather than simply delete.*/
221 /** The address of the request. This address could be virtual or
222 * physical, depending on the system configuration. */
225 /** The size of the request or transfer. */
228 /** Device address (e.g., bus ID) of the source of the
229 * transaction. The source is not responsible for setting this
230 * field; it is set implicitly by the interconnect when the
231 * packet is first sent. */
234 /** Device address (e.g., bus ID) of the destination of the
235 * transaction. The special value Broadcast indicates that the
236 * packet should be routed based on its address. This field is
237 * initialized in the constructor and is thus always valid
238 * (unlike * addr, size, and src). */
241 /** The original value of the command field. Only valid when the
242 * current command field is an error condition; in that case, the
243 * previous contents of the command field are copied here. This
244 * field is *not* set on non-error responses.
248 /** Are the 'addr' and 'size' fields valid? */
250 /** Is the 'src' field valid? */
255 // Snoop response flags
258 // Special control flags
259 /// Special timing-mode atomic snoop for multi-level coherence.
261 /// Does supplier have exclusive copy?
262 /// Useful for multi-level coherence.
268 std::bitset<NUM_PACKET_FLAGS> flags;
272 /** Used to calculate latencies for each packet.*/
275 /** The time at which the packet will be fully transmitted */
278 /** The time at which the first chunk of the packet will be transmitted */
281 /** The special destination address indicating that the packet
282 * should be routed based on its address. */
283 static const short Broadcast = -1;
285 /** A virtual base opaque structure used to hold state associated
286 * with the packet but specific to the sending device (e.g., an
287 * MSHR). A pointer to this state is returned in the packet's
288 * response so that the sender can quickly look up the state
289 * needed to process it. A specific subclass would be derived
290 * from this to carry state specific to a particular sending
292 class SenderState : public FastAlloc {
294 virtual ~SenderState() {}
297 /** This packet's sender state. Devices should use dynamic_cast<>
298 * to cast to the state appropriate to the sender. */
299 SenderState *senderState;
301 /** Return the string name of the cmd field (for debugging and
303 const std::string &cmdString() const { return cmd.toString(); }
305 /** Return the index of this command. */
306 inline int cmdToIndex() const { return cmd.toInt(); }
308 bool isRead() const { return cmd.isRead(); }
309 bool isWrite() const { return cmd.isWrite(); }
310 bool isRequest() const { return cmd.isRequest(); }
311 bool isResponse() const { return cmd.isResponse(); }
312 bool needsExclusive() const { return cmd.needsExclusive(); }
313 bool needsResponse() const { return cmd.needsResponse(); }
314 bool isInvalidate() const { return cmd.isInvalidate(); }
315 bool hasData() const { return cmd.hasData(); }
316 bool isReadWrite() const { return cmd.isReadWrite(); }
317 bool isLocked() const { return cmd.isLocked(); }
318 bool isError() const { return cmd.isError(); }
321 void assertMemInhibit() { flags[MemInhibit] = true; }
322 bool memInhibitAsserted() { return flags[MemInhibit]; }
323 void assertShared() { flags[Shared] = true; }
324 bool sharedAsserted() { return flags[Shared]; }
326 // Special control flags
327 void setExpressSnoop() { flags[ExpressSnoop] = true; }
328 bool isExpressSnoop() { return flags[ExpressSnoop]; }
329 void setSupplyExclusive() { flags[SupplyExclusive] = true; }
330 bool isSupplyExclusive() { return flags[SupplyExclusive]; }
332 // Network error conditions... encapsulate them as methods since
333 // their encoding keeps changing (from result field to command
335 void setNacked() { origCmd = cmd; cmd = MemCmd::NetworkNackError; }
336 void setBadAddress() { origCmd = cmd; cmd = MemCmd::BadAddressError; }
337 bool wasNacked() { return cmd == MemCmd::NetworkNackError; }
338 bool hadBadAddress() { return cmd == MemCmd::BadAddressError; }
340 bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN }
342 /** Accessor function that returns the source index of the packet. */
343 short getSrc() const { assert(srcValid); return src; }
344 void setSrc(short _src) { src = _src; srcValid = true; }
345 /** Reset source field, e.g. to retransmit packet on different bus. */
346 void clearSrc() { srcValid = false; }
348 /** Accessor function that returns the destination index of
350 short getDest() const { assert(destValid); return dest; }
351 void setDest(short _dest) { dest = _dest; destValid = true; }
353 Addr getAddr() const { assert(addrSizeValid); return addr; }
354 int getSize() const { assert(addrSizeValid); return size; }
355 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); }
357 /** Constructor. Note that a Request object must be constructed
358 * first, but the Requests's physical address and size fields
359 * need not be valid. The command and destination addresses
360 * must be supplied. */
361 Packet(Request *_req, MemCmd _cmd, short _dest)
362 : cmd(_cmd), req(_req),
363 data(NULL), staticData(false), dynamicData(false), arrayData(false),
364 addr(_req->paddr), size(_req->size), dest(_dest),
365 addrSizeValid(_req->validPaddr), srcValid(false), destValid(true),
366 flags(0), time(curTick), senderState(NULL)
370 /** Alternate constructor if you are trying to create a packet with
371 * a request that is for a whole block, not the address from the req.
372 * this allows for overriding the size/addr of the req.*/
373 Packet(Request *_req, MemCmd _cmd, short _dest, int _blkSize)
374 : cmd(_cmd), req(_req),
375 data(NULL), staticData(false), dynamicData(false), arrayData(false),
376 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), dest(_dest),
377 addrSizeValid(_req->validPaddr), srcValid(false), destValid(true),
378 flags(0), time(curTick), senderState(NULL)
382 /** Alternate constructor for copying a packet. Copy all fields
383 * *except* if the original packet's data was dynamic, don't copy
384 * that, as we can't guarantee that the new packet's lifetime is
385 * less than that of the original packet. In this case the new
386 * packet should allocate its own data. */
387 Packet(Packet *origPkt, bool clearFlags = false)
388 : cmd(origPkt->cmd), req(origPkt->req),
389 data(origPkt->staticData ? origPkt->data : NULL),
390 staticData(origPkt->staticData),
391 dynamicData(false), arrayData(false),
392 addr(origPkt->addr), size(origPkt->size),
393 src(origPkt->src), dest(origPkt->dest),
394 addrSizeValid(origPkt->addrSizeValid),
395 srcValid(origPkt->srcValid), destValid(origPkt->destValid),
396 flags(clearFlags ? 0 : origPkt->flags),
397 time(curTick), senderState(origPkt->senderState)
403 { if (staticData || dynamicData) deleteData(); }
405 /** Reinitialize packet address and size from the associated
406 * Request object, and reset other fields that may have been
407 * modified by a previous transaction. Typically called when a
408 * statically allocated Request/Packet pair is reused for
409 * multiple transactions. */
410 void reinitFromRequest() {
411 assert(req->validPaddr);
416 addrSizeValid = true;
425 * Take a request packet and modify it in place to be suitable for
426 * returning as a response to that request. The source and
427 * destination fields are *not* modified, as is appropriate for
432 assert(needsResponse());
434 cmd = cmd.responseCommand();
436 destValid = srcValid;
440 void makeAtomicResponse()
445 void makeTimingResponse()
451 * Take a request packet that has been returned as NACKED and
452 * modify it so that it can be sent out again. Only packets that
453 * need a response can be NACKED, so verify that that is true.
460 assert(needsResponse());
466 * Set the data pointer to the following value that should not be
469 template <typename T>
475 data = (PacketDataPtr)p;
480 * Set the data pointer to a value that should have delete []
483 template <typename T>
485 dataDynamicArray(T *p)
487 assert(!staticData && !dynamicData);
488 data = (PacketDataPtr)p;
494 * set the data pointer to a value that should have delete called
497 template <typename T>
501 assert(!staticData && !dynamicData);
502 data = (PacketDataPtr)p;
507 /** get a pointer to the data ptr. */
508 template <typename T>
512 assert(staticData || dynamicData);
516 /** return the value of what is pointed to in the packet. */
517 template <typename T>
520 /** set the value in the data pointer to v. */
521 template <typename T>
525 * Copy data into the packet from the provided pointer.
527 void setData(uint8_t *p)
529 std::memcpy(getPtr<uint8_t>(), p, getSize());
533 * Copy data into the packet from the provided block pointer,
534 * which is aligned to the given block size.
536 void setDataFromBlock(uint8_t *blk_data, int blkSize)
538 setData(blk_data + getOffset(blkSize));
542 * Copy data from the packet to the provided block pointer, which
543 * is aligned to the given block size.
545 void writeData(uint8_t *p)
547 std::memcpy(p, getPtr<uint8_t>(), getSize());
551 * Copy data from the packet to the memory at the provided pointer.
553 void writeDataToBlock(uint8_t *blk_data, int blkSize)
555 writeData(blk_data + getOffset(blkSize));
559 * delete the data pointed to in the data pointer. Ok to call to
560 * matter how data was allocted.
564 /** If there isn't data in the packet, allocate some. */
568 * Check a functional request against a memory value represented
569 * by a base/size pair and an associated data array. If the
570 * functional request is a read, it may be satisfied by the memory
571 * value. If the functional request is a write, it may update the
574 bool checkFunctional(Addr base, int size, uint8_t *data);
577 * Check a functional request against a memory value stored in
578 * another packet (i.e. an in-transit request or response).
580 bool checkFunctional(PacketPtr otherPkt) {
581 return (otherPkt->hasData() &&
582 checkFunctional(otherPkt->getAddr(), otherPkt->getSize(),
583 otherPkt->getPtr<uint8_t>()));
587 std::ostream & operator<<(std::ostream &o, const Packet &p);
589 #endif //__MEM_PACKET_HH