packet.hh revision 3166:0ee91593402d
1/* 2 * Copyright (c) 2006 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Ron Dreslinski 29 * Steve Reinhardt 30 * Ali Saidi 31 */ 32 33/** 34 * @file 35 * Declaration of the Packet class. 36 */ 37 38#ifndef __MEM_PACKET_HH__ 39#define __MEM_PACKET_HH__ 40 41#include "mem/request.hh" 42#include "sim/host.hh" 43#include "sim/root.hh" 44#include <list> 45#include <cassert> 46 47struct Packet; 48typedef Packet* PacketPtr; 49typedef uint8_t* PacketDataPtr; 50typedef std::list<PacketPtr> PacketList; 51 52//Coherence Flags 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 60 61/** 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.) 67 */ 68class Packet 69{ 70 public: 71 /** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */ 72 uint64_t flags; 73 74 private: 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. 80 */ 81 PacketDataPtr data; 82 83 /** Is the data pointer set to a value that shouldn't be freed 84 * when the packet is destroyed? */ 85 bool staticData; 86 /** The data pointer points to a value that should be freed when 87 * the packet is destroyed. */ 88 bool dynamicData; 89 /** the data pointer points to an array (thus delete [] ) needs to 90 * be called on it rather than simply delete.*/ 91 bool arrayData; 92 93 94 /** The address of the request. This address could be virtual or 95 * physical, depending on the system configuration. */ 96 Addr addr; 97 98 /** The size of the request or transfer. */ 99 int size; 100 101 /** 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. */ 105 short src; 106 107 /** 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). */ 112 short dest; 113 114 /** Are the 'addr' and 'size' fields valid? */ 115 bool addrSizeValid; 116 /** Is the 'src' field valid? */ 117 bool srcValid; 118 119 120 public: 121 122 /** Used to calculate latencies for each packet.*/ 123 Tick time; 124 125 /** The special destination address indicating that the packet 126 * should be routed based on its address. */ 127 static const short Broadcast = -1; 128 129 /** A pointer to the original request. */ 130 RequestPtr req; 131 132 /** 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 { 136 public: 137 virtual ~CoherenceState() {} 138 }; 139 140 /** 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; 144 145 /** 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 151 * device. */ 152 class SenderState { 153 public: 154 virtual ~SenderState() {} 155 }; 156 157 /** This packet's sender state. Devices should use dynamic_cast<> 158 * to cast to the state appropriate to the sender. */ 159 SenderState *senderState; 160 161 private: 162 /** List of command attributes. */ 163 // If you add a new CommandAttribute, make sure to increase NUM_MEM_CMDS 164 // as well. 165 enum CommandAttribute 166 { 167 IsRead = 1 << 0, 168 IsWrite = 1 << 1, 169 IsPrefetch = 1 << 2, 170 IsInvalidate = 1 << 3, 171 IsRequest = 1 << 4, 172 IsResponse = 1 << 5, 173 NeedsResponse = 1 << 6, 174 IsSWPrefetch = 1 << 7, 175 IsHWPrefetch = 1 << 8, 176 HasData = 1 << 9 177 }; 178 179//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 << 10 182 183 public: 184 /** List of all commands associated with a packet. */ 185 enum Command 186 { 187 InvalidCmd = 0, 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 | NeedsResponse, 203 UpgradeResp = IsInvalidate | IsResponse | NeedsResponse, 204 ReadExReq = IsRead | IsInvalidate | IsRequest | NeedsResponse, 205 ReadExResp = IsRead | IsInvalidate | IsResponse 206 | NeedsResponse | HasData 207 }; 208 209 /** Return the string name of the cmd field (for debugging and 210 * tracing). */ 211 const std::string &cmdString() const; 212 213 /** Reutrn the string to a cmd given by idx. */ 214 const std::string &cmdIdxToString(Command idx); 215 216 /** Return the index of this command. */ 217 inline int cmdToIndex() const { return (int) cmd; } 218 219 /** The command field of the packet. */ 220 Command cmd; 221 222 bool isRead() { return (cmd & IsRead) != 0; } 223 bool isWrite() { return (cmd & IsWrite) != 0; } 224 bool isRequest() { return (cmd & IsRequest) != 0; } 225 bool isResponse() { return (cmd & IsResponse) != 0; } 226 bool needsResponse() { return (cmd & NeedsResponse) != 0; } 227 bool isInvalidate() { return (cmd & IsInvalidate) != 0; } 228 bool hasData() { return (cmd & HasData) != 0; } 229 230 bool isCacheFill() { return (flags & CACHE_LINE_FILL) != 0; } 231 bool isNoAllocate() { return (flags & NO_ALLOCATE) != 0; } 232 bool isCompressed() { return (flags & COMPRESSED) != 0; } 233 234 bool nic_pkt() { assert("Unimplemented\n" && 0); return false; } 235 236 /** Possible results of a packet's request. */ 237 enum Result 238 { 239 Success, 240 BadAddress, 241 Nacked, 242 Unknown 243 }; 244 245 /** The result of this packet's request. */ 246 Result result; 247 248 /** Accessor function that returns the source index of the packet. */ 249 short getSrc() const { assert(srcValid); return src; } 250 void setSrc(short _src) { src = _src; srcValid = true; } 251 252 /** Accessor function that returns the destination index of 253 the packet. */ 254 short getDest() const { return dest; } 255 void setDest(short _dest) { dest = _dest; } 256 257 Addr getAddr() const { assert(addrSizeValid); return addr; } 258 int getSize() const { assert(addrSizeValid); return size; } 259 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); } 260 261 void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; } 262 void cmdOverride(Command newCmd) { cmd = newCmd; } 263 264 /** Constructor. Note that a Request object must be constructed 265 * first, but the Requests's physical address and size fields 266 * need not be valid. The command and destination addresses 267 * must be supplied. */ 268 Packet(Request *_req, Command _cmd, short _dest) 269 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 270 addr(_req->paddr), size(_req->size), dest(_dest), 271 addrSizeValid(_req->validPaddr), 272 srcValid(false), 273 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 274 result(Unknown) 275 { 276 flags = 0; 277 time = curTick; 278 } 279 280 /** Alternate constructor if you are trying to create a packet with 281 * a request that is for a whole block, not the address from the req. 282 * this allows for overriding the size/addr of the req.*/ 283 Packet(Request *_req, Command _cmd, short _dest, int _blkSize) 284 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 285 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), 286 dest(_dest), 287 addrSizeValid(_req->validPaddr), srcValid(false), 288 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 289 result(Unknown) 290 { 291 flags = 0; 292 time = curTick; 293 } 294 295 /** Destructor. */ 296 ~Packet() 297 { deleteData(); } 298 299 /** Reinitialize packet address and size from the associated 300 * Request object, and reset other fields that may have been 301 * modified by a previous transaction. Typically called when a 302 * statically allocated Request/Packet pair is reused for 303 * multiple transactions. */ 304 void reinitFromRequest() { 305 assert(req->validPaddr); 306 addr = req->paddr; 307 size = req->size; 308 time = req->time; 309 addrSizeValid = true; 310 result = Unknown; 311 if (dynamicData) { 312 deleteData(); 313 dynamicData = false; 314 arrayData = false; 315 } 316 } 317 318 /** Take a request packet and modify it in place to be suitable 319 * for returning as a response to that request. Used for timing 320 * accesses only. For atomic and functional accesses, the 321 * request packet is always implicitly passed back *without* 322 * modifying the destination fields, so this function 323 * should not be called. */ 324 void makeTimingResponse() { 325 assert(needsResponse()); 326 assert(isRequest()); 327 int icmd = (int)cmd; 328 icmd &= ~(IsRequest); 329 icmd |= IsResponse; 330 cmd = (Command)icmd; 331 dest = src; 332 srcValid = false; 333 } 334 335 /** Take a request packet and modify it in place to be suitable 336 * for returning as a response to that request. 337 */ 338 void makeAtomicResponse() { 339 assert(needsResponse()); 340 assert(isRequest()); 341 int icmd = (int)cmd; 342 icmd &= ~(IsRequest); 343 icmd |= IsResponse; 344 cmd = (Command)icmd; 345 } 346 347 /** Take a request packet that has been returned as NACKED and modify it so 348 * that it can be sent out again. Only packets that need a response can be 349 * NACKED, so verify that that is true. */ 350 void reinitNacked() { 351 assert(needsResponse() && result == Nacked); 352 dest = Broadcast; 353 result = Unknown; 354 } 355 356 357 /** Set the data pointer to the following value that should not be freed. */ 358 template <typename T> 359 void dataStatic(T *p); 360 361 /** Set the data pointer to a value that should have delete [] called on it. 362 */ 363 template <typename T> 364 void dataDynamicArray(T *p); 365 366 /** set the data pointer to a value that should have delete called on it. */ 367 template <typename T> 368 void dataDynamic(T *p); 369 370 /** return the value of what is pointed to in the packet. */ 371 template <typename T> 372 T get(); 373 374 /** get a pointer to the data ptr. */ 375 template <typename T> 376 T* getPtr(); 377 378 /** set the value in the data pointer to v. */ 379 template <typename T> 380 void set(T v); 381 382 /** delete the data pointed to in the data pointer. Ok to call to matter how 383 * data was allocted. */ 384 void deleteData(); 385 386 /** If there isn't data in the packet, allocate some. */ 387 void allocate(); 388 389 /** Do the packet modify the same addresses. */ 390 bool intersect(Packet *p); 391}; 392 393bool fixPacket(Packet *func, Packet *timing); 394#endif //__MEM_PACKET_HH 395