packet.hh revision 4026:7c8c480474c6
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 <cassert> 42#include <list> 43#include <bitset> 44 45#include "base/compiler.hh" 46#include "base/misc.hh" 47#include "mem/request.hh" 48#include "sim/host.hh" 49#include "sim/root.hh" 50 51 52struct Packet; 53typedef Packet *PacketPtr; 54typedef uint8_t* PacketDataPtr; 55typedef std::list<PacketPtr> PacketList; 56 57//Coherence Flags 58#define NACKED_LINE (1 << 0) 59#define SATISFIED (1 << 1) 60#define SHARED_LINE (1 << 2) 61#define CACHE_LINE_FILL (1 << 3) 62#define COMPRESSED (1 << 4) 63#define NO_ALLOCATE (1 << 5) 64#define SNOOP_COMMIT (1 << 6) 65 66 67class MemCmd 68{ 69 public: 70 71 /** List of all commands associated with a packet. */ 72 enum Command 73 { 74 InvalidCmd, 75 ReadReq, 76 WriteReq, 77 WriteReqNoAck, 78 ReadResp, 79 WriteResp, 80 Writeback, 81 SoftPFReq, 82 HardPFReq, 83 SoftPFResp, 84 HardPFResp, 85 InvalidateReq, 86 WriteInvalidateReq, 87 WriteInvalidateResp, 88 UpgradeReq, 89 ReadExReq, 90 ReadExResp, 91 NUM_MEM_CMDS 92 }; 93 94 private: 95 /** List of command attributes. */ 96 enum Attribute 97 { 98 IsRead, 99 IsWrite, 100 IsPrefetch, 101 IsInvalidate, 102 IsRequest, 103 IsResponse, 104 NeedsResponse, 105 IsSWPrefetch, 106 IsHWPrefetch, 107 IsUpgrade, 108 HasData, 109 NUM_COMMAND_ATTRIBUTES 110 }; 111 112 /** Structure that defines attributes and other data associated 113 * with a Command. */ 114 struct CommandInfo { 115 /** Set of attribute flags. */ 116 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 117 /** Corresponding response for requests; InvalidCmd if no 118 * response is applicable. */ 119 const Command response; 120 /** String representation (for printing) */ 121 const std::string str; 122 }; 123 124 /** Array to map Command enum to associated info. */ 125 static const CommandInfo commandInfo[]; 126 127 private: 128 129 Command cmd; 130 131 bool testCmdAttrib(MemCmd::Attribute attrib) const { 132 return commandInfo[cmd].attributes[attrib] != 0; 133 } 134 135 public: 136 137 bool isRead() const { return testCmdAttrib(IsRead); } 138 bool isWrite() const { return testCmdAttrib(IsWrite); } 139 bool isRequest() const { return testCmdAttrib(IsRequest); } 140 bool isResponse() const { return testCmdAttrib(IsResponse); } 141 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 142 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 143 bool hasData() const { return testCmdAttrib(HasData); } 144 145 const Command responseCommand() const { 146 return commandInfo[cmd].response; 147 } 148 149 /** Return the string to a cmd given by idx. */ 150 const std::string &toString() const { 151 return commandInfo[cmd].str; 152 } 153 154 int toInt() const { return (int)cmd; } 155 156 MemCmd(Command _cmd) 157 : cmd(_cmd) 158 { } 159 160 MemCmd(int _cmd) 161 : cmd((Command)_cmd) 162 { } 163 164 MemCmd() 165 : cmd(InvalidCmd) 166 { } 167 168 bool operator==(MemCmd c2) { return (cmd == c2.cmd); } 169 bool operator!=(MemCmd c2) { return (cmd != c2.cmd); } 170 171 friend class Packet; 172}; 173 174/** 175 * A Packet is used to encapsulate a transfer between two objects in 176 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 177 * single Request travels all the way from the requester to the 178 * ultimate destination and back, possibly being conveyed by several 179 * different Packets along the way.) 180 */ 181class Packet 182{ 183 public: 184 185 typedef MemCmd::Command Command; 186 187 /** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */ 188 uint64_t flags; 189 190 private: 191 /** A pointer to the data being transfered. It can be differnt 192 * sizes at each level of the heirarchy so it belongs in the 193 * packet, not request. This may or may not be populated when a 194 * responder recieves the packet. If not populated it memory 195 * should be allocated. 196 */ 197 PacketDataPtr data; 198 199 /** Is the data pointer set to a value that shouldn't be freed 200 * when the packet is destroyed? */ 201 bool staticData; 202 /** The data pointer points to a value that should be freed when 203 * the packet is destroyed. */ 204 bool dynamicData; 205 /** the data pointer points to an array (thus delete [] ) needs to 206 * be called on it rather than simply delete.*/ 207 bool arrayData; 208 209 /** The address of the request. This address could be virtual or 210 * physical, depending on the system configuration. */ 211 Addr addr; 212 213 /** The size of the request or transfer. */ 214 int size; 215 216 /** Device address (e.g., bus ID) of the source of the 217 * transaction. The source is not responsible for setting this 218 * field; it is set implicitly by the interconnect when the 219 * packet is first sent. */ 220 short src; 221 222 /** Device address (e.g., bus ID) of the destination of the 223 * transaction. The special value Broadcast indicates that the 224 * packet should be routed based on its address. This field is 225 * initialized in the constructor and is thus always valid 226 * (unlike * addr, size, and src). */ 227 short dest; 228 229 /** Are the 'addr' and 'size' fields valid? */ 230 bool addrSizeValid; 231 /** Is the 'src' field valid? */ 232 bool srcValid; 233 234 235 public: 236 237 /** Used to calculate latencies for each packet.*/ 238 Tick time; 239 240 /** The time at which the packet will be fully transmitted */ 241 Tick finishTime; 242 243 /** The time at which the first chunk of the packet will be transmitted */ 244 Tick firstWordTime; 245 246 /** The special destination address indicating that the packet 247 * should be routed based on its address. */ 248 static const short Broadcast = -1; 249 250 /** A pointer to the original request. */ 251 RequestPtr req; 252 253 /** A virtual base opaque structure used to hold coherence-related 254 * state. A specific subclass would be derived from this to 255 * carry state specific to a particular coherence protocol. */ 256 class CoherenceState { 257 public: 258 virtual ~CoherenceState() {} 259 }; 260 261 /** This packet's coherence state. Caches should use 262 * dynamic_cast<> to cast to the state appropriate for the 263 * system's coherence protocol. */ 264 CoherenceState *coherence; 265 266 /** A virtual base opaque structure used to hold state associated 267 * with the packet but specific to the sending device (e.g., an 268 * MSHR). A pointer to this state is returned in the packet's 269 * response so that the sender can quickly look up the state 270 * needed to process it. A specific subclass would be derived 271 * from this to carry state specific to a particular sending 272 * device. */ 273 class SenderState { 274 public: 275 virtual ~SenderState() {} 276 }; 277 278 /** This packet's sender state. Devices should use dynamic_cast<> 279 * to cast to the state appropriate to the sender. */ 280 SenderState *senderState; 281 282 public: 283 284 /** The command field of the packet. */ 285 MemCmd cmd; 286 287 /** Return the string name of the cmd field (for debugging and 288 * tracing). */ 289 const std::string &cmdString() const { return cmd.toString(); } 290 291 /** Return the index of this command. */ 292 inline int cmdToIndex() const { return cmd.toInt(); } 293 294 public: 295 296 bool isRead() const { return cmd.isRead(); } 297 bool isWrite() const { return cmd.isWrite(); } 298 bool isRequest() const { return cmd.isRequest(); } 299 bool isResponse() const { return cmd.isResponse(); } 300 bool needsResponse() const { return cmd.needsResponse(); } 301 bool isInvalidate() const { return cmd.isInvalidate(); } 302 bool hasData() const { return cmd.hasData(); } 303 304 bool isCacheFill() const { return (flags & CACHE_LINE_FILL) != 0; } 305 bool isNoAllocate() const { return (flags & NO_ALLOCATE) != 0; } 306 bool isCompressed() const { return (flags & COMPRESSED) != 0; } 307 308 bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN } 309 310 /** Possible results of a packet's request. */ 311 enum Result 312 { 313 Success, 314 BadAddress, 315 Nacked, 316 Unknown 317 }; 318 319 /** The result of this packet's request. */ 320 Result result; 321 322 /** Accessor function that returns the source index of the packet. */ 323 short getSrc() const { assert(srcValid); return src; } 324 void setSrc(short _src) { src = _src; srcValid = true; } 325 326 /** Accessor function that returns the destination index of 327 the packet. */ 328 short getDest() const { return dest; } 329 void setDest(short _dest) { dest = _dest; } 330 331 Addr getAddr() const { assert(addrSizeValid); return addr; } 332 int getSize() const { assert(addrSizeValid); return size; } 333 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); } 334 335 void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; } 336 void cmdOverride(MemCmd newCmd) { cmd = newCmd; } 337 338 /** Constructor. Note that a Request object must be constructed 339 * first, but the Requests's physical address and size fields 340 * need not be valid. The command and destination addresses 341 * must be supplied. */ 342 Packet(Request *_req, MemCmd _cmd, short _dest) 343 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 344 addr(_req->paddr), size(_req->size), dest(_dest), 345 addrSizeValid(_req->validPaddr), 346 srcValid(false), 347 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 348 result(Unknown) 349 { 350 flags = 0; 351 time = curTick; 352 } 353 354 /** Alternate constructor if you are trying to create a packet with 355 * a request that is for a whole block, not the address from the req. 356 * this allows for overriding the size/addr of the req.*/ 357 Packet(Request *_req, MemCmd _cmd, short _dest, int _blkSize) 358 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 359 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), 360 dest(_dest), 361 addrSizeValid(_req->validPaddr), srcValid(false), 362 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 363 result(Unknown) 364 { 365 flags = 0; 366 time = curTick; 367 } 368 369 /** Destructor. */ 370 ~Packet() 371 { if (staticData || dynamicData) deleteData(); } 372 373 /** Reinitialize packet address and size from the associated 374 * Request object, and reset other fields that may have been 375 * modified by a previous transaction. Typically called when a 376 * statically allocated Request/Packet pair is reused for 377 * multiple transactions. */ 378 void reinitFromRequest() { 379 assert(req->validPaddr); 380 flags = 0; 381 addr = req->paddr; 382 size = req->size; 383 time = req->time; 384 addrSizeValid = true; 385 result = Unknown; 386 if (dynamicData) { 387 deleteData(); 388 dynamicData = false; 389 arrayData = false; 390 } 391 } 392 393 /** Take a request packet and modify it in place to be suitable 394 * for returning as a response to that request. Used for timing 395 * accesses only. For atomic and functional accesses, the 396 * request packet is always implicitly passed back *without* 397 * modifying the destination fields, so this function 398 * should not be called. */ 399 void makeTimingResponse() { 400 assert(needsResponse()); 401 assert(isRequest()); 402 cmd = cmd.responseCommand(); 403 dest = src; 404 srcValid = false; 405 } 406 407 /** 408 * Take a request packet and modify it in place to be suitable for 409 * returning as a response to that request. 410 */ 411 void makeAtomicResponse() 412 { 413 assert(needsResponse()); 414 assert(isRequest()); 415 cmd = cmd.responseCommand(); 416 } 417 418 /** 419 * Take a request packet that has been returned as NACKED and 420 * modify it so that it can be sent out again. Only packets that 421 * need a response can be NACKED, so verify that that is true. 422 */ 423 void 424 reinitNacked() 425 { 426 assert(needsResponse() && result == Nacked); 427 dest = Broadcast; 428 result = Unknown; 429 } 430 431 432 /** 433 * Set the data pointer to the following value that should not be 434 * freed. 435 */ 436 template <typename T> 437 void 438 dataStatic(T *p) 439 { 440 if(dynamicData) 441 dynamicData = false; 442 data = (PacketDataPtr)p; 443 staticData = true; 444 } 445 446 /** 447 * Set the data pointer to a value that should have delete [] 448 * called on it. 449 */ 450 template <typename T> 451 void 452 dataDynamicArray(T *p) 453 { 454 assert(!staticData && !dynamicData); 455 data = (PacketDataPtr)p; 456 dynamicData = true; 457 arrayData = true; 458 } 459 460 /** 461 * set the data pointer to a value that should have delete called 462 * on it. 463 */ 464 template <typename T> 465 void 466 dataDynamic(T *p) 467 { 468 assert(!staticData && !dynamicData); 469 data = (PacketDataPtr)p; 470 dynamicData = true; 471 arrayData = false; 472 } 473 474 /** get a pointer to the data ptr. */ 475 template <typename T> 476 T* 477 getPtr() 478 { 479 assert(staticData || dynamicData); 480 return (T*)data; 481 } 482 483 /** return the value of what is pointed to in the packet. */ 484 template <typename T> 485 T get(); 486 487 /** set the value in the data pointer to v. */ 488 template <typename T> 489 void set(T v); 490 491 /** 492 * delete the data pointed to in the data pointer. Ok to call to 493 * matter how data was allocted. 494 */ 495 void deleteData(); 496 497 /** If there isn't data in the packet, allocate some. */ 498 void allocate(); 499 500 /** Do the packet modify the same addresses. */ 501 bool intersect(PacketPtr p); 502}; 503 504/** This function given a functional packet and a timing packet either satisfies 505 * the timing packet, or updates the timing packet to reflect the updated state 506 * in the timing packet. It returns if the functional packet should continue to 507 * traverse the memory hierarchy or not. 508 */ 509bool fixPacket(PacketPtr func, PacketPtr timing); 510 511/** This function is a wrapper for the fixPacket field that toggles the hasData bit 512 * it is used when a response is waiting in the caches, but hasn't been marked as a 513 * response yet (so the fixPacket needs to get the correct value for the hasData) 514 */ 515bool fixDelayedResponsePacket(PacketPtr func, PacketPtr timing); 516 517std::ostream & operator<<(std::ostream &o, const Packet &p); 518 519#endif //__MEM_PACKET_HH 520