packet.hh revision 4610:97834b18a8b4
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/fast_alloc.hh" 47#include "base/misc.hh" 48#include "mem/request.hh" 49#include "sim/host.hh" 50#include "sim/core.hh" 51 52 53struct Packet; 54typedef Packet *PacketPtr; 55typedef uint8_t* PacketDataPtr; 56typedef std::list<PacketPtr> PacketList; 57 58//Coherence Flags 59#define NACKED_LINE (1 << 0) 60#define SATISFIED (1 << 1) 61#define SHARED_LINE (1 << 2) 62#define CACHE_LINE_FILL (1 << 3) 63#define COMPRESSED (1 << 4) 64#define NO_ALLOCATE (1 << 5) 65#define SNOOP_COMMIT (1 << 6) 66 67 68class MemCmd 69{ 70 public: 71 72 /** List of all commands associated with a packet. */ 73 enum Command 74 { 75 InvalidCmd, 76 ReadReq, 77 WriteReq, 78 WriteReqNoAck, 79 ReadResp, 80 WriteResp, 81 Writeback, 82 SoftPFReq, 83 HardPFReq, 84 SoftPFResp, 85 HardPFResp, 86 InvalidateReq, 87 WriteInvalidateReq, 88 WriteInvalidateResp, 89 UpgradeReq, 90 ReadExReq, 91 ReadExResp, 92 SwapReq, 93 SwapResp, 94 NUM_MEM_CMDS 95 }; 96 97 private: 98 /** List of command attributes. */ 99 enum Attribute 100 { 101 IsRead, 102 IsWrite, 103 IsPrefetch, 104 IsInvalidate, 105 IsRequest, 106 IsResponse, 107 NeedsResponse, 108 IsSWPrefetch, 109 IsHWPrefetch, 110 IsUpgrade, 111 HasData, 112 IsReadWrite, 113 NUM_COMMAND_ATTRIBUTES 114 }; 115 116 /** Structure that defines attributes and other data associated 117 * with a Command. */ 118 struct CommandInfo { 119 /** Set of attribute flags. */ 120 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 121 /** Corresponding response for requests; InvalidCmd if no 122 * response is applicable. */ 123 const Command response; 124 /** String representation (for printing) */ 125 const std::string str; 126 }; 127 128 /** Array to map Command enum to associated info. */ 129 static const CommandInfo commandInfo[]; 130 131 private: 132 133 Command cmd; 134 135 bool testCmdAttrib(MemCmd::Attribute attrib) const { 136 return commandInfo[cmd].attributes[attrib] != 0; 137 } 138 139 public: 140 141 bool isRead() const { return testCmdAttrib(IsRead); } 142 bool isWrite() const { return testCmdAttrib(IsWrite); } 143 bool isRequest() const { return testCmdAttrib(IsRequest); } 144 bool isResponse() const { return testCmdAttrib(IsResponse); } 145 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 146 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 147 bool hasData() const { return testCmdAttrib(HasData); } 148 bool isReadWrite() const { return testCmdAttrib(IsReadWrite); } 149 150 const Command responseCommand() const { 151 return commandInfo[cmd].response; 152 } 153 154 /** Return the string to a cmd given by idx. */ 155 const std::string &toString() const { 156 return commandInfo[cmd].str; 157 } 158 159 int toInt() const { return (int)cmd; } 160 161 MemCmd(Command _cmd) 162 : cmd(_cmd) 163 { } 164 165 MemCmd(int _cmd) 166 : cmd((Command)_cmd) 167 { } 168 169 MemCmd() 170 : cmd(InvalidCmd) 171 { } 172 173 bool operator==(MemCmd c2) { return (cmd == c2.cmd); } 174 bool operator!=(MemCmd c2) { return (cmd != c2.cmd); } 175 176 friend class Packet; 177}; 178 179/** 180 * A Packet is used to encapsulate a transfer between two objects in 181 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 182 * single Request travels all the way from the requester to the 183 * ultimate destination and back, possibly being conveyed by several 184 * different Packets along the way.) 185 */ 186class Packet : public FastAlloc 187{ 188 public: 189 190 typedef MemCmd::Command Command; 191 192 /** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */ 193 uint64_t flags; 194 195 private: 196 /** A pointer to the data being transfered. It can be differnt 197 * sizes at each level of the heirarchy so it belongs in the 198 * packet, not request. This may or may not be populated when a 199 * responder recieves the packet. If not populated it memory 200 * should be allocated. 201 */ 202 PacketDataPtr data; 203 204 /** Is the data pointer set to a value that shouldn't be freed 205 * when the packet is destroyed? */ 206 bool staticData; 207 /** The data pointer points to a value that should be freed when 208 * the packet is destroyed. */ 209 bool dynamicData; 210 /** the data pointer points to an array (thus delete [] ) needs to 211 * be called on it rather than simply delete.*/ 212 bool arrayData; 213 214 /** The address of the request. This address could be virtual or 215 * physical, depending on the system configuration. */ 216 Addr addr; 217 218 /** The size of the request or transfer. */ 219 int size; 220 221 /** Device address (e.g., bus ID) of the source of the 222 * transaction. The source is not responsible for setting this 223 * field; it is set implicitly by the interconnect when the 224 * packet is first sent. */ 225 short src; 226 227 /** Device address (e.g., bus ID) of the destination of the 228 * transaction. The special value Broadcast indicates that the 229 * packet should be routed based on its address. This field is 230 * initialized in the constructor and is thus always valid 231 * (unlike * addr, size, and src). */ 232 short dest; 233 234 /** Are the 'addr' and 'size' fields valid? */ 235 bool addrSizeValid; 236 /** Is the 'src' field valid? */ 237 bool srcValid; 238 239 240 public: 241 242 /** Used to calculate latencies for each packet.*/ 243 Tick time; 244 245 /** The time at which the packet will be fully transmitted */ 246 Tick finishTime; 247 248 /** The time at which the first chunk of the packet will be transmitted */ 249 Tick firstWordTime; 250 251 /** The special destination address indicating that the packet 252 * should be routed based on its address. */ 253 static const short Broadcast = -1; 254 255 /** A pointer to the original request. */ 256 RequestPtr req; 257 258 /** A virtual base opaque structure used to hold coherence-related 259 * state. A specific subclass would be derived from this to 260 * carry state specific to a particular coherence protocol. */ 261 class CoherenceState : public FastAlloc { 262 public: 263 virtual ~CoherenceState() {} 264 }; 265 266 /** This packet's coherence state. Caches should use 267 * dynamic_cast<> to cast to the state appropriate for the 268 * system's coherence protocol. */ 269 CoherenceState *coherence; 270 271 /** A virtual base opaque structure used to hold state associated 272 * with the packet but specific to the sending device (e.g., an 273 * MSHR). A pointer to this state is returned in the packet's 274 * response so that the sender can quickly look up the state 275 * needed to process it. A specific subclass would be derived 276 * from this to carry state specific to a particular sending 277 * device. */ 278 class SenderState : public FastAlloc { 279 public: 280 virtual ~SenderState() {} 281 }; 282 283 /** This packet's sender state. Devices should use dynamic_cast<> 284 * to cast to the state appropriate to the sender. */ 285 SenderState *senderState; 286 287 public: 288 289 /** The command field of the packet. */ 290 MemCmd cmd; 291 292 /** Return the string name of the cmd field (for debugging and 293 * tracing). */ 294 const std::string &cmdString() const { return cmd.toString(); } 295 296 /** Return the index of this command. */ 297 inline int cmdToIndex() const { return cmd.toInt(); } 298 299 public: 300 301 bool isRead() const { return cmd.isRead(); } 302 bool isWrite() const { return cmd.isWrite(); } 303 bool isRequest() const { return cmd.isRequest(); } 304 bool isResponse() const { return cmd.isResponse(); } 305 bool needsResponse() const { return cmd.needsResponse(); } 306 bool isInvalidate() const { return cmd.isInvalidate(); } 307 bool hasData() const { return cmd.hasData(); } 308 bool isReadWrite() const { return cmd.isReadWrite(); } 309 310 bool isCacheFill() const { return (flags & CACHE_LINE_FILL) != 0; } 311 bool isNoAllocate() const { return (flags & NO_ALLOCATE) != 0; } 312 bool isCompressed() const { return (flags & COMPRESSED) != 0; } 313 314 bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN } 315 316 /** Possible results of a packet's request. */ 317 enum Result 318 { 319 Success, 320 BadAddress, 321 Nacked, 322 Unknown 323 }; 324 325 /** The result of this packet's request. */ 326 Result result; 327 328 /** Accessor function that returns the source index of the packet. */ 329 short getSrc() const { assert(srcValid); return src; } 330 void setSrc(short _src) { src = _src; srcValid = true; } 331 332 /** Accessor function that returns the destination index of 333 the packet. */ 334 short getDest() const { return dest; } 335 void setDest(short _dest) { dest = _dest; } 336 337 Addr getAddr() const { assert(addrSizeValid); return addr; } 338 int getSize() const { assert(addrSizeValid); return size; } 339 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); } 340 341 void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; } 342 void cmdOverride(MemCmd newCmd) { cmd = newCmd; } 343 344 /** Constructor. Note that a Request object must be constructed 345 * first, but the Requests's physical address and size fields 346 * need not be valid. The command and destination addresses 347 * must be supplied. */ 348 Packet(Request *_req, MemCmd _cmd, short _dest) 349 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 350 addr(_req->paddr), size(_req->size), dest(_dest), 351 addrSizeValid(_req->validPaddr), 352 srcValid(false), 353 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 354 result(Unknown) 355 { 356 flags = 0; 357 time = curTick; 358 } 359 360 /** Alternate constructor if you are trying to create a packet with 361 * a request that is for a whole block, not the address from the req. 362 * this allows for overriding the size/addr of the req.*/ 363 Packet(Request *_req, MemCmd _cmd, short _dest, int _blkSize) 364 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 365 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), 366 dest(_dest), 367 addrSizeValid(_req->validPaddr), srcValid(false), 368 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 369 result(Unknown) 370 { 371 flags = 0; 372 time = curTick; 373 } 374 375 /** Destructor. */ 376 ~Packet() 377 { if (staticData || dynamicData) deleteData(); } 378 379 /** Reinitialize packet address and size from the associated 380 * Request object, and reset other fields that may have been 381 * modified by a previous transaction. Typically called when a 382 * statically allocated Request/Packet pair is reused for 383 * multiple transactions. */ 384 void reinitFromRequest() { 385 assert(req->validPaddr); 386 flags = 0; 387 addr = req->paddr; 388 size = req->size; 389 time = req->time; 390 addrSizeValid = true; 391 result = Unknown; 392 if (dynamicData) { 393 deleteData(); 394 dynamicData = false; 395 arrayData = false; 396 } 397 } 398 399 /** Take a request packet and modify it in place to be suitable 400 * for returning as a response to that request. Used for timing 401 * accesses only. For atomic and functional accesses, the 402 * request packet is always implicitly passed back *without* 403 * modifying the destination fields, so this function 404 * should not be called. */ 405 void makeTimingResponse() { 406 assert(needsResponse()); 407 assert(isRequest()); 408 cmd = cmd.responseCommand(); 409 dest = src; 410 srcValid = false; 411 } 412 413 /** 414 * Take a request packet and modify it in place to be suitable for 415 * returning as a response to that request. 416 */ 417 void makeAtomicResponse() 418 { 419 assert(needsResponse()); 420 assert(isRequest()); 421 cmd = cmd.responseCommand(); 422 } 423 424 /** 425 * Take a request packet that has been returned as NACKED and 426 * modify it so that it can be sent out again. Only packets that 427 * need a response can be NACKED, so verify that that is true. 428 */ 429 void 430 reinitNacked() 431 { 432 assert(needsResponse() && result == Nacked); 433 dest = Broadcast; 434 result = Unknown; 435 } 436 437 438 /** 439 * Set the data pointer to the following value that should not be 440 * freed. 441 */ 442 template <typename T> 443 void 444 dataStatic(T *p) 445 { 446 if(dynamicData) 447 dynamicData = false; 448 data = (PacketDataPtr)p; 449 staticData = true; 450 } 451 452 /** 453 * Set the data pointer to a value that should have delete [] 454 * called on it. 455 */ 456 template <typename T> 457 void 458 dataDynamicArray(T *p) 459 { 460 assert(!staticData && !dynamicData); 461 data = (PacketDataPtr)p; 462 dynamicData = true; 463 arrayData = true; 464 } 465 466 /** 467 * set the data pointer to a value that should have delete called 468 * on it. 469 */ 470 template <typename T> 471 void 472 dataDynamic(T *p) 473 { 474 assert(!staticData && !dynamicData); 475 data = (PacketDataPtr)p; 476 dynamicData = true; 477 arrayData = false; 478 } 479 480 /** get a pointer to the data ptr. */ 481 template <typename T> 482 T* 483 getPtr() 484 { 485 assert(staticData || dynamicData); 486 return (T*)data; 487 } 488 489 /** return the value of what is pointed to in the packet. */ 490 template <typename T> 491 T get(); 492 493 /** set the value in the data pointer to v. */ 494 template <typename T> 495 void set(T v); 496 497 /** 498 * delete the data pointed to in the data pointer. Ok to call to 499 * matter how data was allocted. 500 */ 501 void deleteData(); 502 503 /** If there isn't data in the packet, allocate some. */ 504 void allocate(); 505 506 /** Do the packet modify the same addresses. */ 507 bool intersect(PacketPtr p); 508}; 509 510/** This function given a functional packet and a timing packet either 511 * satisfies the timing packet, or updates the timing packet to 512 * reflect the updated state in the timing packet. It returns if the 513 * functional packet should continue to traverse the memory hierarchy 514 * or not. 515 */ 516bool fixPacket(PacketPtr func, PacketPtr timing); 517 518/** This function is a wrapper for the fixPacket field that toggles 519 * the hasData bit it is used when a response is waiting in the 520 * caches, but hasn't been marked as a response yet (so the fixPacket 521 * needs to get the correct value for the hasData) 522 */ 523bool fixDelayedResponsePacket(PacketPtr func, PacketPtr timing); 524 525std::ostream & operator<<(std::ostream &o, const Packet &p); 526 527#endif //__MEM_PACKET_HH 528