2 * Copyright (c) 2006 The Regents of The University of Michigan
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28 * Authors: Ron Dreslinski
35 * Declaration of the Packet class.
38 #ifndef __MEM_PACKET_HH__
39 #define __MEM_PACKET_HH__
41 #include "mem/request.hh"
42 #include "sim/host.hh"
43 #include "sim/root.hh"
48 typedef Packet* PacketPtr;
49 typedef uint8_t* PacketDataPtr;
50 typedef std::list<PacketPtr> PacketList;
53 #define NACKED_LINE 1 << 0
54 #define SATISFIED 1 << 1
55 #define SHARED_LINE 1 << 2
56 #define CACHE_LINE_FILL 1 << 3
57 #define COMPRESSED 1 << 4
58 #define NO_ALLOCATE 1 << 5
59 #define SNOOP_COMMIT 1 << 6
62 * A Packet is used to encapsulate a transfer between two objects in
63 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
64 * single Request travels all the way from the requester to the
65 * ultimate destination and back, possibly being conveyed by several
66 * different Packets along the way.)
71 /** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */
75 /** A pointer to the data being transfered. It can be differnt
76 * sizes at each level of the heirarchy so it belongs in the
77 * packet, not request. This may or may not be populated when a
78 * responder recieves the packet. If not populated it memory
79 * should be allocated.
83 /** Is the data pointer set to a value that shouldn't be freed
84 * when the packet is destroyed? */
86 /** The data pointer points to a value that should be freed when
87 * the packet is destroyed. */
89 /** the data pointer points to an array (thus delete [] ) needs to
90 * be called on it rather than simply delete.*/
94 /** The address of the request. This address could be virtual or
95 * physical, depending on the system configuration. */
98 /** The size of the request or transfer. */
101 /** Device address (e.g., bus ID) of the source of the
102 * transaction. The source is not responsible for setting this
103 * field; it is set implicitly by the interconnect when the
104 * packet * is first sent. */
107 /** Device address (e.g., bus ID) of the destination of the
108 * transaction. The special value Broadcast indicates that the
109 * packet should be routed based on its address. This field is
110 * initialized in the constructor and is thus always valid
111 * (unlike * addr, size, and src). */
114 /** Are the 'addr' and 'size' fields valid? */
116 /** Is the 'src' field valid? */
122 /** Used to calculate latencies for each packet.*/
125 /** The special destination address indicating that the packet
126 * should be routed based on its address. */
127 static const short Broadcast = -1;
129 /** A pointer to the original request. */
132 /** A virtual base opaque structure used to hold coherence-related
133 * state. A specific subclass would be derived from this to
134 * carry state specific to a particular coherence protocol. */
135 class CoherenceState {
137 virtual ~CoherenceState() {}
140 /** This packet's coherence state. Caches should use
141 * dynamic_cast<> to cast to the state appropriate for the
142 * system's coherence protocol. */
143 CoherenceState *coherence;
145 /** A virtual base opaque structure used to hold state associated
146 * with the packet but specific to the sending device (e.g., an
147 * MSHR). A pointer to this state is returned in the packet's
148 * response so that the sender can quickly look up the state
149 * needed to process it. A specific subclass would be derived
150 * from this to carry state specific to a particular sending
154 virtual ~SenderState() {}
157 /** This packet's sender state. Devices should use dynamic_cast<>
158 * to cast to the state appropriate to the sender. */
159 SenderState *senderState;
162 /** List of command attributes. */
163 // If you add a new CommandAttribute, make sure to increase NUM_MEM_CMDS
165 enum CommandAttribute
170 IsInvalidate = 1 << 3,
173 NeedsResponse = 1 << 6,
174 IsSWPrefetch = 1 << 7,
175 IsHWPrefetch = 1 << 8,
179 //For statistics we need max number of commands, hard code it at
180 //20 for now. @todo fix later
181 #define NUM_MEM_CMDS 1 << 10
184 /** List of all commands associated with a packet. */
188 ReadReq = IsRead | IsRequest | NeedsResponse,
189 WriteReq = IsWrite | IsRequest | NeedsResponse | HasData,
190 WriteReqNoAck = IsWrite | IsRequest | HasData,
191 ReadResp = IsRead | IsResponse | NeedsResponse | HasData,
192 WriteResp = IsWrite | IsResponse | NeedsResponse,
193 Writeback = IsWrite | IsRequest | HasData,
194 SoftPFReq = IsRead | IsRequest | IsSWPrefetch | NeedsResponse,
195 HardPFReq = IsRead | IsRequest | IsHWPrefetch | NeedsResponse,
196 SoftPFResp = IsRead | IsResponse | IsSWPrefetch
197 | NeedsResponse | HasData,
198 HardPFResp = IsRead | IsResponse | IsHWPrefetch
199 | NeedsResponse | HasData,
200 InvalidateReq = IsInvalidate | IsRequest,
201 WriteInvalidateReq = IsWrite | IsInvalidate | IsRequest | HasData,
202 UpgradeReq = IsInvalidate | IsRequest,
203 ReadExReq = IsRead | IsInvalidate | IsRequest | NeedsResponse,
204 ReadExResp = IsRead | IsInvalidate | IsResponse
205 | NeedsResponse | HasData
208 /** Return the string name of the cmd field (for debugging and
210 const std::string &cmdString() const;
212 /** Reutrn the string to a cmd given by idx. */
213 const std::string &cmdIdxToString(Command idx);
215 /** Return the index of this command. */
216 inline int cmdToIndex() const { return (int) cmd; }
218 /** The command field of the packet. */
221 bool isRead() { return (cmd & IsRead) != 0; }
222 bool isWrite() { return (cmd & IsWrite) != 0; }
223 bool isRequest() { return (cmd & IsRequest) != 0; }
224 bool isResponse() { return (cmd & IsResponse) != 0; }
225 bool needsResponse() { return (cmd & NeedsResponse) != 0; }
226 bool isInvalidate() { return (cmd & IsInvalidate) != 0; }
227 bool hasData() { return (cmd & HasData) != 0; }
229 bool isCacheFill() { return (flags & CACHE_LINE_FILL) != 0; }
230 bool isNoAllocate() { return (flags & NO_ALLOCATE) != 0; }
231 bool isCompressed() { return (flags & COMPRESSED) != 0; }
233 bool nic_pkt() { assert("Unimplemented\n" && 0); return false; }
235 /** Possible results of a packet's request. */
244 /** The result of this packet's request. */
247 /** Accessor function that returns the source index of the packet. */
248 short getSrc() const { assert(srcValid); return src; }
249 void setSrc(short _src) { src = _src; srcValid = true; }
251 /** Accessor function that returns the destination index of
253 short getDest() const { return dest; }
254 void setDest(short _dest) { dest = _dest; }
256 Addr getAddr() const { assert(addrSizeValid); return addr; }
257 int getSize() const { assert(addrSizeValid); return size; }
258 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); }
260 void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; }
261 void cmdOverride(Command newCmd) { cmd = newCmd; }
263 /** Constructor. Note that a Request object must be constructed
264 * first, but the Requests's physical address and size fields
265 * need not be valid. The command and destination addresses
266 * must be supplied. */
267 Packet(Request *_req, Command _cmd, short _dest)
268 : data(NULL), staticData(false), dynamicData(false), arrayData(false),
269 addr(_req->paddr), size(_req->size), dest(_dest),
270 addrSizeValid(_req->validPaddr),
272 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd),
279 /** Alternate constructor if you are trying to create a packet with
280 * a request that is for a whole block, not the address from the req.
281 * this allows for overriding the size/addr of the req.*/
282 Packet(Request *_req, Command _cmd, short _dest, int _blkSize)
283 : data(NULL), staticData(false), dynamicData(false), arrayData(false),
284 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize),
286 addrSizeValid(_req->validPaddr), srcValid(false),
287 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd),
298 /** Reinitialize packet address and size from the associated
299 * Request object, and reset other fields that may have been
300 * modified by a previous transaction. Typically called when a
301 * statically allocated Request/Packet pair is reused for
302 * multiple transactions. */
303 void reinitFromRequest() {
304 assert(req->validPaddr);
308 addrSizeValid = true;
317 /** Take a request packet and modify it in place to be suitable
318 * for returning as a response to that request. Used for timing
319 * accesses only. For atomic and functional accesses, the
320 * request packet is always implicitly passed back *without*
321 * modifying the destination fields, so this function
322 * should not be called. */
323 void makeTimingResponse() {
324 assert(needsResponse());
327 icmd &= ~(IsRequest);
334 /** Take a request packet and modify it in place to be suitable
335 * for returning as a response to that request.
337 void makeAtomicResponse() {
338 assert(needsResponse());
341 icmd &= ~(IsRequest);
346 /** Take a request packet that has been returned as NACKED and modify it so
347 * that it can be sent out again. Only packets that need a response can be
348 * NACKED, so verify that that is true. */
349 void reinitNacked() {
350 assert(needsResponse() && result == Nacked);
356 /** Set the data pointer to the following value that should not be freed. */
357 template <typename T>
358 void dataStatic(T *p);
360 /** Set the data pointer to a value that should have delete [] called on it.
362 template <typename T>
363 void dataDynamicArray(T *p);
365 /** set the data pointer to a value that should have delete called on it. */
366 template <typename T>
367 void dataDynamic(T *p);
369 /** return the value of what is pointed to in the packet. */
370 template <typename T>
373 /** get a pointer to the data ptr. */
374 template <typename T>
377 /** set the value in the data pointer to v. */
378 template <typename T>
381 /** delete the data pointed to in the data pointer. Ok to call to matter how
382 * data was allocted. */
385 /** If there isn't data in the packet, allocate some. */
388 /** Do the packet modify the same addresses. */
389 bool intersect(Packet *p);
392 bool fixPacket(Packet *func, Packet *timing);
393 #endif //__MEM_PACKET_HH