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 "arch/isa_traits.hh"
43 #include "sim/root.hh"
47 typedef Packet* PacketPtr;
48 typedef uint8_t* PacketDataPtr;
49 typedef std::list<PacketPtr> PacketList;
52 #define NACKED_LINE 1 << 0
53 #define SATISFIED 1 << 1
54 #define SHARED_LINE 1 << 2
55 #define CACHE_LINE_FILL 1 << 3
56 #define COMPRESSED 1 << 4
57 #define NO_ALLOCATE 1 << 5
59 //For statistics we need max number of commands, hard code it at
60 //20 for now. @todo fix later
61 #define NUM_MEM_CMDS 1 << 9
64 * A Packet is used to encapsulate a transfer between two objects in
65 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
66 * single Request travels all the way from the requester to the
67 * ultimate destination and back, possibly being conveyed by several
68 * different Packets along the way.)
73 /** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */
77 /** A pointer to the data being transfered. It can be differnt
78 * sizes at each level of the heirarchy so it belongs in the
79 * packet, not request. This may or may not be populated when a
80 * responder recieves the packet. If not populated it memory
81 * should be allocated.
85 /** Is the data pointer set to a value that shouldn't be freed
86 * when the packet is destroyed? */
88 /** The data pointer points to a value that should be freed when
89 * the packet is destroyed. */
91 /** the data pointer points to an array (thus delete [] ) needs to
92 * be called on it rather than simply delete.*/
96 /** The address of the request. This address could be virtual or
97 * physical, depending on the system configuration. */
100 /** The size of the request or transfer. */
103 /** Device address (e.g., bus ID) of the source of the
104 * transaction. The source is not responsible for setting this
105 * field; it is set implicitly by the interconnect when the
106 * packet * is first sent. */
109 /** Device address (e.g., bus ID) of the destination of the
110 * transaction. The special value Broadcast indicates that the
111 * packet should be routed based on its address. This field is
112 * initialized in the constructor and is thus always valid
113 * (unlike * addr, size, and src). */
116 /** Are the 'addr' and 'size' fields valid? */
118 /** Is the 'src' field valid? */
124 /** Used to calculate latencies for each packet.*/
127 /** The special destination address indicating that the packet
128 * should be routed based on its address. */
129 static const short Broadcast = -1;
131 /** A pointer to the original request. */
134 /** A virtual base opaque structure used to hold coherence-related
135 * state. A specific subclass would be derived from this to
136 * carry state specific to a particular coherence protocol. */
137 class CoherenceState {
139 virtual ~CoherenceState() {}
142 /** This packet's coherence state. Caches should use
143 * dynamic_cast<> to cast to the state appropriate for the
144 * system's coherence protocol. */
145 CoherenceState *coherence;
147 /** A virtual base opaque structure used to hold state associated
148 * with the packet but specific to the sending device (e.g., an
149 * MSHR). A pointer to this state is returned in the packet's
150 * response so that the sender can quickly look up the state
151 * needed to process it. A specific subclass would be derived
152 * from this to carry state specific to a particular sending
156 virtual ~SenderState() {}
159 /** This packet's sender state. Devices should use dynamic_cast<>
160 * to cast to the state appropriate to the sender. */
161 SenderState *senderState;
164 /** List of command attributes. */
165 enum CommandAttribute
170 IsInvalidate = 1 << 3,
173 NeedsResponse = 1 << 6,
174 IsSWPrefetch = 1 << 7,
175 IsHWPrefetch = 1 << 8
179 /** List of all commands associated with a packet. */
183 ReadReq = IsRead | IsRequest | NeedsResponse,
184 WriteReq = IsWrite | IsRequest | NeedsResponse,
185 WriteReqNoAck = IsWrite | IsRequest,
186 ReadResp = IsRead | IsResponse,
187 WriteResp = IsWrite | IsResponse,
188 Writeback = IsWrite | IsRequest,
189 SoftPFReq = IsRead | IsRequest | IsSWPrefetch | NeedsResponse,
190 HardPFReq = IsRead | IsRequest | IsHWPrefetch | NeedsResponse,
191 SoftPFResp = IsRead | IsRequest | IsSWPrefetch | IsResponse,
192 HardPFResp = IsRead | IsRequest | IsHWPrefetch | IsResponse,
193 InvalidateReq = IsInvalidate | IsRequest,
194 WriteInvalidateReq = IsWrite | IsInvalidate | IsRequest,
195 UpgradeReq = IsInvalidate | NeedsResponse,
196 UpgradeResp = IsInvalidate | IsResponse,
197 ReadExReq = IsRead | IsInvalidate | NeedsResponse,
198 ReadExResp = IsRead | IsInvalidate | IsResponse
201 /** Return the string name of the cmd field (for debugging and
203 const std::string &cmdString() const;
205 /** Reutrn the string to a cmd given by idx. */
206 const std::string &cmdIdxToString(Command idx);
208 /** Return the index of this command. */
209 inline int cmdToIndex() const { return (int) cmd; }
211 /** The command field of the packet. */
214 bool isRead() { return (cmd & IsRead) != 0; }
215 bool isWrite() { return (cmd & IsWrite) != 0; }
216 bool isRequest() { return (cmd & IsRequest) != 0; }
217 bool isResponse() { return (cmd & IsResponse) != 0; }
218 bool needsResponse() { return (cmd & NeedsResponse) != 0; }
219 bool isInvalidate() { return (cmd * IsInvalidate) != 0; }
221 bool isCacheFill() { return (flags & CACHE_LINE_FILL) != 0; }
222 bool isNoAllocate() { return (flags & NO_ALLOCATE) != 0; }
223 bool isCompressed() { return (flags & COMPRESSED) != 0; }
225 bool nic_pkt() { assert("Unimplemented\n" && 0); }
227 /** Possible results of a packet's request. */
236 /** The result of this packet's request. */
239 /** Accessor function that returns the source index of the packet. */
240 short getSrc() const { assert(srcValid); return src; }
241 void setSrc(short _src) { src = _src; srcValid = true; }
243 /** Accessor function that returns the destination index of
245 short getDest() const { return dest; }
246 void setDest(short _dest) { dest = _dest; }
248 Addr getAddr() const { assert(addrSizeValid); return addr; }
249 int getSize() const { assert(addrSizeValid); return size; }
250 Addr getOffset(int blkSize) const { return req->getPaddr() & (Addr)(blkSize - 1); }
252 void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; }
253 void cmdOverride(Command newCmd) { cmd = newCmd; }
255 /** Constructor. Note that a Request object must be constructed
256 * first, but the Requests's physical address and size fields
257 * need not be valid. The command and destination addresses
258 * must be supplied. */
259 Packet(Request *_req, Command _cmd, short _dest)
260 : data(NULL), staticData(false), dynamicData(false), arrayData(false),
261 addr(_req->paddr), size(_req->size), dest(_dest),
262 addrSizeValid(_req->validPaddr),
264 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd),
270 /** Alternate constructor if you are trying to create a packet with
271 * a request that is for a whole block, not the address from the req.
272 * this allows for overriding the size/addr of the req.*/
273 Packet(Request *_req, Command _cmd, short _dest, int _blkSize)
274 : data(NULL), staticData(false), dynamicData(false), arrayData(false),
275 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize),
277 addrSizeValid(_req->validPaddr), srcValid(false),
278 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd),
288 /** Reinitialize packet address and size from the associated
289 * Request object, and reset other fields that may have been
290 * modified by a previous transaction. Typically called when a
291 * statically allocated Request/Packet pair is reused for
292 * multiple transactions. */
293 void reinitFromRequest() {
294 assert(req->validPaddr);
297 addrSizeValid = true;
306 /** Take a request packet and modify it in place to be suitable
307 * for returning as a response to that request. Used for timing
308 * accesses only. For atomic and functional accesses, the
309 * request packet is always implicitly passed back *without*
310 * modifying the command or destination fields, so this function
311 * should not be called. */
312 void makeTimingResponse() {
313 assert(needsResponse());
315 icmd &= ~(IsRequest | NeedsResponse);
322 /** Take a request packet that has been returned as NACKED and modify it so
323 * that it can be sent out again. Only packets that need a response can be
324 * NACKED, so verify that that is true. */
325 void reinitNacked() {
326 assert(needsResponse() && result == Nacked);
332 /** Set the data pointer to the following value that should not be freed. */
333 template <typename T>
334 void dataStatic(T *p);
336 /** Set the data pointer to a value that should have delete [] called on it.
338 template <typename T>
339 void dataDynamicArray(T *p);
341 /** set the data pointer to a value that should have delete called on it. */
342 template <typename T>
343 void dataDynamic(T *p);
345 /** return the value of what is pointed to in the packet. */
346 template <typename T>
349 /** get a pointer to the data ptr. */
350 template <typename T>
353 /** set the value in the data pointer to v. */
354 template <typename T>
357 /** delete the data pointed to in the data pointer. Ok to call to matter how
358 * data was allocted. */
361 /** If there isn't data in the packet, allocate some. */
364 /** Do the packet modify the same addresses. */
365 bool intersect(Packet *p);
368 bool fixPacket(Packet *func, Packet *timing);
369 #endif //__MEM_PACKET_HH