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