packet.hh revision 5650
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 "base/printable.hh" 49#include "mem/request.hh" 50#include "sim/host.hh" 51#include "sim/core.hh" 52 53 54struct Packet; 55typedef Packet *PacketPtr; 56typedef uint8_t* PacketDataPtr; 57typedef std::list<PacketPtr> PacketList; 58 59class MemCmd 60{ 61 public: 62 63 /** List of all commands associated with a packet. */ 64 enum Command 65 { 66 InvalidCmd, 67 ReadReq, 68 ReadResp, 69 ReadRespWithInvalidate, 70 WriteReq, 71 WriteResp, 72 Writeback, 73 SoftPFReq, 74 HardPFReq, 75 SoftPFResp, 76 HardPFResp, 77 WriteInvalidateReq, 78 WriteInvalidateResp, 79 UpgradeReq, 80 UpgradeResp, 81 ReadExReq, 82 ReadExResp, 83 LoadLockedReq, 84 StoreCondReq, 85 StoreCondResp, 86 SwapReq, 87 SwapResp, 88 MessageReq, 89 MessageResp, 90 // Error responses 91 // @TODO these should be classified as responses rather than 92 // requests; coding them as requests initially for backwards 93 // compatibility 94 NetworkNackError, // nacked at network layer (not by protocol) 95 InvalidDestError, // packet dest field invalid 96 BadAddressError, // memory address invalid 97 // Fake simulator-only commands 98 PrintReq, // Print state matching address 99 NUM_MEM_CMDS 100 }; 101 102 private: 103 /** List of command attributes. */ 104 enum Attribute 105 { 106 IsRead, //!< Data flows from responder to requester 107 IsWrite, //!< Data flows from requester to responder 108 IsPrefetch, //!< Not a demand access 109 IsInvalidate, 110 NeedsExclusive, //!< Requires exclusive copy to complete in-cache 111 IsRequest, //!< Issued by requester 112 IsResponse, //!< Issue by responder 113 NeedsResponse, //!< Requester needs response from target 114 IsSWPrefetch, 115 IsHWPrefetch, 116 IsLocked, //!< Alpha/MIPS LL or SC access 117 HasData, //!< There is an associated payload 118 IsError, //!< Error response 119 IsPrint, //!< Print state matching address (for debugging) 120 NUM_COMMAND_ATTRIBUTES 121 }; 122 123 /** Structure that defines attributes and other data associated 124 * with a Command. */ 125 struct CommandInfo { 126 /** Set of attribute flags. */ 127 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 128 /** Corresponding response for requests; InvalidCmd if no 129 * response is applicable. */ 130 const Command response; 131 /** String representation (for printing) */ 132 const std::string str; 133 }; 134 135 /** Array to map Command enum to associated info. */ 136 static const CommandInfo commandInfo[]; 137 138 private: 139 140 Command cmd; 141 142 bool testCmdAttrib(MemCmd::Attribute attrib) const { 143 return commandInfo[cmd].attributes[attrib] != 0; 144 } 145 146 public: 147 148 bool isRead() const { return testCmdAttrib(IsRead); } 149 bool isWrite() const { return testCmdAttrib(IsWrite); } 150 bool isRequest() const { return testCmdAttrib(IsRequest); } 151 bool isResponse() const { return testCmdAttrib(IsResponse); } 152 bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); } 153 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 154 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 155 bool hasData() const { return testCmdAttrib(HasData); } 156 bool isReadWrite() const { return isRead() && isWrite(); } 157 bool isLocked() const { return testCmdAttrib(IsLocked); } 158 bool isError() const { return testCmdAttrib(IsError); } 159 bool isPrint() const { return testCmdAttrib(IsPrint); } 160 161 const Command responseCommand() const { 162 return commandInfo[cmd].response; 163 } 164 165 /** Return the string to a cmd given by idx. */ 166 const std::string &toString() const { 167 return commandInfo[cmd].str; 168 } 169 170 int toInt() const { return (int)cmd; } 171 172 MemCmd(Command _cmd) 173 : cmd(_cmd) 174 { } 175 176 MemCmd(int _cmd) 177 : cmd((Command)_cmd) 178 { } 179 180 MemCmd() 181 : cmd(InvalidCmd) 182 { } 183 184 bool operator==(MemCmd c2) { return (cmd == c2.cmd); } 185 bool operator!=(MemCmd c2) { return (cmd != c2.cmd); } 186 187 friend class Packet; 188}; 189 190/** 191 * A Packet is used to encapsulate a transfer between two objects in 192 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 193 * single Request travels all the way from the requester to the 194 * ultimate destination and back, possibly being conveyed by several 195 * different Packets along the way.) 196 */ 197class Packet : public FastAlloc, public Printable 198{ 199 public: 200 201 typedef MemCmd::Command Command; 202 203 /** The command field of the packet. */ 204 MemCmd cmd; 205 206 /** A pointer to the original request. */ 207 RequestPtr req; 208 209 private: 210 /** A pointer to the data being transfered. It can be differnt 211 * sizes at each level of the heirarchy so it belongs in the 212 * packet, not request. This may or may not be populated when a 213 * responder recieves the packet. If not populated it memory 214 * should be allocated. 215 */ 216 PacketDataPtr data; 217 218 /** Is the data pointer set to a value that shouldn't be freed 219 * when the packet is destroyed? */ 220 bool staticData; 221 /** The data pointer points to a value that should be freed when 222 * the packet is destroyed. */ 223 bool dynamicData; 224 /** the data pointer points to an array (thus delete [] ) needs to 225 * be called on it rather than simply delete.*/ 226 bool arrayData; 227 228 /** The address of the request. This address could be virtual or 229 * physical, depending on the system configuration. */ 230 Addr addr; 231 232 /** The size of the request or transfer. */ 233 int size; 234 235 /** Device address (e.g., bus ID) of the source of the 236 * transaction. The source is not responsible for setting this 237 * field; it is set implicitly by the interconnect when the 238 * packet is first sent. */ 239 short src; 240 241 /** Device address (e.g., bus ID) of the destination of the 242 * transaction. The special value Broadcast indicates that the 243 * packet should be routed based on its address. This field is 244 * initialized in the constructor and is thus always valid 245 * (unlike * addr, size, and src). */ 246 short dest; 247 248 /** The original value of the command field. Only valid when the 249 * current command field is an error condition; in that case, the 250 * previous contents of the command field are copied here. This 251 * field is *not* set on non-error responses. 252 */ 253 MemCmd origCmd; 254 255 /** Are the 'addr' and 'size' fields valid? */ 256 bool addrSizeValid; 257 /** Is the 'src' field valid? */ 258 bool srcValid; 259 bool destValid; 260 261 enum Flag { 262 // Snoop response flags 263 MemInhibit, 264 Shared, 265 // Special control flags 266 /// Special timing-mode atomic snoop for multi-level coherence. 267 ExpressSnoop, 268 /// Does supplier have exclusive copy? 269 /// Useful for multi-level coherence. 270 SupplyExclusive, 271 NUM_PACKET_FLAGS 272 }; 273 274 /** Status flags */ 275 std::bitset<NUM_PACKET_FLAGS> flags; 276 277 public: 278 279 /** Used to calculate latencies for each packet.*/ 280 Tick time; 281 282 /** The time at which the packet will be fully transmitted */ 283 Tick finishTime; 284 285 /** The time at which the first chunk of the packet will be transmitted */ 286 Tick firstWordTime; 287 288 /** The special destination address indicating that the packet 289 * should be routed based on its address. */ 290 static const short Broadcast = -1; 291 292 /** A virtual base opaque structure used to hold state associated 293 * with the packet but specific to the sending device (e.g., an 294 * MSHR). A pointer to this state is returned in the packet's 295 * response so that the sender can quickly look up the state 296 * needed to process it. A specific subclass would be derived 297 * from this to carry state specific to a particular sending 298 * device. */ 299 class SenderState { 300 public: 301 virtual ~SenderState() {} 302 }; 303 304 /** 305 * Object used to maintain state of a PrintReq. The senderState 306 * field of a PrintReq should always be of this type. 307 */ 308 class PrintReqState : public SenderState, public FastAlloc { 309 /** An entry in the label stack. */ 310 class LabelStackEntry { 311 public: 312 const std::string label; 313 std::string *prefix; 314 bool labelPrinted; 315 LabelStackEntry(const std::string &_label, 316 std::string *_prefix); 317 }; 318 319 typedef std::list<LabelStackEntry> LabelStack; 320 LabelStack labelStack; 321 322 std::string *curPrefixPtr; 323 324 public: 325 std::ostream &os; 326 const int verbosity; 327 328 PrintReqState(std::ostream &os, int verbosity = 0); 329 ~PrintReqState(); 330 331 /** Returns the current line prefix. */ 332 const std::string &curPrefix() { return *curPrefixPtr; } 333 334 /** Push a label onto the label stack, and prepend the given 335 * prefix string onto the current prefix. Labels will only be 336 * printed if an object within the label's scope is 337 * printed. */ 338 void pushLabel(const std::string &lbl, 339 const std::string &prefix = " "); 340 /** Pop a label off the label stack. */ 341 void popLabel(); 342 /** Print all of the pending unprinted labels on the 343 * stack. Called by printObj(), so normally not called by 344 * users unless bypassing printObj(). */ 345 void printLabels(); 346 /** Print a Printable object to os, because it matched the 347 * address on a PrintReq. */ 348 void printObj(Printable *obj); 349 }; 350 351 /** This packet's sender state. Devices should use dynamic_cast<> 352 * to cast to the state appropriate to the sender. */ 353 SenderState *senderState; 354 355 /** Return the string name of the cmd field (for debugging and 356 * tracing). */ 357 const std::string &cmdString() const { return cmd.toString(); } 358 359 /** Return the index of this command. */ 360 inline int cmdToIndex() const { return cmd.toInt(); } 361 362 bool isRead() const { return cmd.isRead(); } 363 bool isWrite() const { return cmd.isWrite(); } 364 bool isRequest() const { return cmd.isRequest(); } 365 bool isResponse() const { return cmd.isResponse(); } 366 bool needsExclusive() const { return cmd.needsExclusive(); } 367 bool needsResponse() const { return cmd.needsResponse(); } 368 bool isInvalidate() const { return cmd.isInvalidate(); } 369 bool hasData() const { return cmd.hasData(); } 370 bool isReadWrite() const { return cmd.isReadWrite(); } 371 bool isLocked() const { return cmd.isLocked(); } 372 bool isError() const { return cmd.isError(); } 373 bool isPrint() const { return cmd.isPrint(); } 374 375 // Snoop flags 376 void assertMemInhibit() { flags[MemInhibit] = true; } 377 bool memInhibitAsserted() { return flags[MemInhibit]; } 378 void assertShared() { flags[Shared] = true; } 379 bool sharedAsserted() { return flags[Shared]; } 380 381 // Special control flags 382 void setExpressSnoop() { flags[ExpressSnoop] = true; } 383 bool isExpressSnoop() { return flags[ExpressSnoop]; } 384 void setSupplyExclusive() { flags[SupplyExclusive] = true; } 385 bool isSupplyExclusive() { return flags[SupplyExclusive]; } 386 387 // Network error conditions... encapsulate them as methods since 388 // their encoding keeps changing (from result field to command 389 // field, etc.) 390 void setNacked() { assert(isResponse()); cmd = MemCmd::NetworkNackError; } 391 void setBadAddress() { assert(isResponse()); cmd = MemCmd::BadAddressError; } 392 bool wasNacked() { return cmd == MemCmd::NetworkNackError; } 393 bool hadBadAddress() { return cmd == MemCmd::BadAddressError; } 394 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 395 396 bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN } 397 398 /** Accessor function that returns the source index of the packet. */ 399 short getSrc() const { assert(srcValid); return src; } 400 void setSrc(short _src) { src = _src; srcValid = true; } 401 /** Reset source field, e.g. to retransmit packet on different bus. */ 402 void clearSrc() { srcValid = false; } 403 404 /** Accessor function that returns the destination index of 405 the packet. */ 406 short getDest() const { assert(destValid); return dest; } 407 void setDest(short _dest) { dest = _dest; destValid = true; } 408 409 Addr getAddr() const { assert(addrSizeValid); return addr; } 410 int getSize() const { assert(addrSizeValid); return size; } 411 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); } 412 413 /** Constructor. Note that a Request object must be constructed 414 * first, but the Requests's physical address and size fields 415 * need not be valid. The command and destination addresses 416 * must be supplied. */ 417 Packet(Request *_req, MemCmd _cmd, short _dest) 418 : cmd(_cmd), req(_req), 419 data(NULL), staticData(false), dynamicData(false), arrayData(false), 420 addr(_req->paddr), size(_req->size), dest(_dest), 421 addrSizeValid(_req->validPaddr), srcValid(false), destValid(true), 422 flags(0), time(curTick), senderState(NULL) 423 { 424 } 425 426 /** Alternate constructor if you are trying to create a packet with 427 * a request that is for a whole block, not the address from the req. 428 * this allows for overriding the size/addr of the req.*/ 429 Packet(Request *_req, MemCmd _cmd, short _dest, int _blkSize) 430 : cmd(_cmd), req(_req), 431 data(NULL), staticData(false), dynamicData(false), arrayData(false), 432 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), dest(_dest), 433 addrSizeValid(_req->validPaddr), srcValid(false), destValid(true), 434 flags(0), time(curTick), senderState(NULL) 435 { 436 } 437 438 /** Alternate constructor for copying a packet. Copy all fields 439 * *except* if the original packet's data was dynamic, don't copy 440 * that, as we can't guarantee that the new packet's lifetime is 441 * less than that of the original packet. In this case the new 442 * packet should allocate its own data. */ 443 Packet(Packet *origPkt, bool clearFlags = false) 444 : cmd(origPkt->cmd), req(origPkt->req), 445 data(origPkt->staticData ? origPkt->data : NULL), 446 staticData(origPkt->staticData), 447 dynamicData(false), arrayData(false), 448 addr(origPkt->addr), size(origPkt->size), 449 src(origPkt->src), dest(origPkt->dest), 450 addrSizeValid(origPkt->addrSizeValid), 451 srcValid(origPkt->srcValid), destValid(origPkt->destValid), 452 flags(clearFlags ? 0 : origPkt->flags), 453 time(curTick), senderState(origPkt->senderState) 454 { 455 } 456 457 /** Destructor. */ 458 ~Packet() 459 { 460 // If this is a request packet for which there's no response, 461 // delete the request object here, since the requester will 462 // never get the chance. 463 if (req && isRequest() && !needsResponse()) 464 delete req; 465 if (staticData || dynamicData) 466 deleteData(); 467 } 468 469 /** Reinitialize packet address and size from the associated 470 * Request object, and reset other fields that may have been 471 * modified by a previous transaction. Typically called when a 472 * statically allocated Request/Packet pair is reused for 473 * multiple transactions. */ 474 void reinitFromRequest() { 475 assert(req->validPaddr); 476 flags = 0; 477 addr = req->paddr; 478 size = req->size; 479 time = req->time; 480 addrSizeValid = true; 481 if (dynamicData) { 482 deleteData(); 483 dynamicData = false; 484 arrayData = false; 485 } 486 } 487 488 /** 489 * Take a request packet and modify it in place to be suitable for 490 * returning as a response to that request. The source and 491 * destination fields are *not* modified, as is appropriate for 492 * atomic accesses. 493 */ 494 void makeResponse() 495 { 496 assert(needsResponse()); 497 assert(isRequest()); 498 origCmd = cmd; 499 cmd = cmd.responseCommand(); 500 dest = src; 501 destValid = srcValid; 502 srcValid = false; 503 } 504 505 void makeAtomicResponse() 506 { 507 makeResponse(); 508 } 509 510 void makeTimingResponse() 511 { 512 makeResponse(); 513 } 514 515 /** 516 * Take a request packet that has been returned as NACKED and 517 * modify it so that it can be sent out again. Only packets that 518 * need a response can be NACKED, so verify that that is true. 519 */ 520 void 521 reinitNacked() 522 { 523 assert(wasNacked()); 524 cmd = origCmd; 525 assert(needsResponse()); 526 setDest(Broadcast); 527 } 528 529 530 /** 531 * Set the data pointer to the following value that should not be 532 * freed. 533 */ 534 template <typename T> 535 void 536 dataStatic(T *p) 537 { 538 if(dynamicData) 539 dynamicData = false; 540 data = (PacketDataPtr)p; 541 staticData = true; 542 } 543 544 /** 545 * Set the data pointer to a value that should have delete [] 546 * called on it. 547 */ 548 template <typename T> 549 void 550 dataDynamicArray(T *p) 551 { 552 assert(!staticData && !dynamicData); 553 data = (PacketDataPtr)p; 554 dynamicData = true; 555 arrayData = true; 556 } 557 558 /** 559 * set the data pointer to a value that should have delete called 560 * on it. 561 */ 562 template <typename T> 563 void 564 dataDynamic(T *p) 565 { 566 assert(!staticData && !dynamicData); 567 data = (PacketDataPtr)p; 568 dynamicData = true; 569 arrayData = false; 570 } 571 572 /** get a pointer to the data ptr. */ 573 template <typename T> 574 T* 575 getPtr() 576 { 577 assert(staticData || dynamicData); 578 return (T*)data; 579 } 580 581 /** return the value of what is pointed to in the packet. */ 582 template <typename T> 583 T get(); 584 585 /** set the value in the data pointer to v. */ 586 template <typename T> 587 void set(T v); 588 589 /** 590 * Copy data into the packet from the provided pointer. 591 */ 592 void setData(uint8_t *p) 593 { 594 std::memcpy(getPtr<uint8_t>(), p, getSize()); 595 } 596 597 /** 598 * Copy data into the packet from the provided block pointer, 599 * which is aligned to the given block size. 600 */ 601 void setDataFromBlock(uint8_t *blk_data, int blkSize) 602 { 603 setData(blk_data + getOffset(blkSize)); 604 } 605 606 /** 607 * Copy data from the packet to the provided block pointer, which 608 * is aligned to the given block size. 609 */ 610 void writeData(uint8_t *p) 611 { 612 std::memcpy(p, getPtr<uint8_t>(), getSize()); 613 } 614 615 /** 616 * Copy data from the packet to the memory at the provided pointer. 617 */ 618 void writeDataToBlock(uint8_t *blk_data, int blkSize) 619 { 620 writeData(blk_data + getOffset(blkSize)); 621 } 622 623 /** 624 * delete the data pointed to in the data pointer. Ok to call to 625 * matter how data was allocted. 626 */ 627 void deleteData(); 628 629 /** If there isn't data in the packet, allocate some. */ 630 void allocate(); 631 632 /** 633 * Check a functional request against a memory value represented 634 * by a base/size pair and an associated data array. If the 635 * functional request is a read, it may be satisfied by the memory 636 * value. If the functional request is a write, it may update the 637 * memory value. 638 */ 639 bool checkFunctional(Printable *obj, Addr base, int size, uint8_t *data); 640 641 /** 642 * Check a functional request against a memory value stored in 643 * another packet (i.e. an in-transit request or response). 644 */ 645 bool checkFunctional(PacketPtr otherPkt) { 646 return checkFunctional(otherPkt, 647 otherPkt->getAddr(), otherPkt->getSize(), 648 otherPkt->hasData() ? 649 otherPkt->getPtr<uint8_t>() : NULL); 650 } 651 652 /** 653 * Push label for PrintReq (safe to call unconditionally). 654 */ 655 void pushLabel(const std::string &lbl) { 656 if (isPrint()) { 657 dynamic_cast<PrintReqState*>(senderState)->pushLabel(lbl); 658 } 659 } 660 661 /** 662 * Pop label for PrintReq (safe to call unconditionally). 663 */ 664 void popLabel() { 665 if (isPrint()) { 666 dynamic_cast<PrintReqState*>(senderState)->popLabel(); 667 } 668 } 669 670 void print(std::ostream &o, int verbosity = 0, 671 const std::string &prefix = "") const; 672}; 673 674#endif //__MEM_PACKET_HH 675