packet.hh revision 10896
1/* 2 * Copyright (c) 2012-2015 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Copyright (c) 2006 The Regents of The University of Michigan 15 * Copyright (c) 2010 Advanced Micro Devices, Inc. 16 * All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions are 20 * met: redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer; 22 * redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution; 25 * neither the name of the copyright holders nor the names of its 26 * contributors may be used to endorse or promote products derived from 27 * this software without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 30 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 31 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 32 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 33 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 34 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 35 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 39 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 40 * 41 * Authors: Ron Dreslinski 42 * Steve Reinhardt 43 * Ali Saidi 44 * Andreas Hansson 45 */ 46 47/** 48 * @file 49 * Declaration of the Packet class. 50 */ 51 52#ifndef __MEM_PACKET_HH__ 53#define __MEM_PACKET_HH__ 54 55#include <bitset> 56#include <cassert> 57#include <list> 58 59#include "base/cast.hh" 60#include "base/compiler.hh" 61#include "base/flags.hh" 62#include "base/misc.hh" 63#include "base/printable.hh" 64#include "base/types.hh" 65#include "mem/request.hh" 66#include "sim/core.hh" 67 68class Packet; 69typedef Packet *PacketPtr; 70typedef uint8_t* PacketDataPtr; 71typedef std::list<PacketPtr> PacketList; 72 73class MemCmd 74{ 75 friend class Packet; 76 77 public: 78 /** 79 * List of all commands associated with a packet. 80 */ 81 enum Command 82 { 83 InvalidCmd, 84 ReadReq, 85 ReadResp, 86 ReadRespWithInvalidate, 87 WriteReq, 88 WriteResp, 89 Writeback, 90 CleanEvict, 91 SoftPFReq, 92 HardPFReq, 93 SoftPFResp, 94 HardPFResp, 95 WriteLineReq, 96 UpgradeReq, 97 SCUpgradeReq, // Special "weak" upgrade for StoreCond 98 UpgradeResp, 99 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent) 100 UpgradeFailResp, // Valid for SCUpgradeReq only 101 ReadExReq, 102 ReadExResp, 103 ReadCleanReq, 104 ReadSharedReq, 105 LoadLockedReq, 106 StoreCondReq, 107 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent) 108 StoreCondResp, 109 SwapReq, 110 SwapResp, 111 MessageReq, 112 MessageResp, 113 // Error responses 114 // @TODO these should be classified as responses rather than 115 // requests; coding them as requests initially for backwards 116 // compatibility 117 InvalidDestError, // packet dest field invalid 118 BadAddressError, // memory address invalid 119 FunctionalReadError, // unable to fulfill functional read 120 FunctionalWriteError, // unable to fulfill functional write 121 // Fake simulator-only commands 122 PrintReq, // Print state matching address 123 FlushReq, //request for a cache flush 124 InvalidateReq, // request for address to be invalidated 125 InvalidateResp, 126 NUM_MEM_CMDS 127 }; 128 129 private: 130 /** 131 * List of command attributes. 132 */ 133 enum Attribute 134 { 135 IsRead, //!< Data flows from responder to requester 136 IsWrite, //!< Data flows from requester to responder 137 IsUpgrade, 138 IsInvalidate, 139 NeedsExclusive, //!< Requires exclusive copy to complete in-cache 140 IsRequest, //!< Issued by requester 141 IsResponse, //!< Issue by responder 142 NeedsResponse, //!< Requester needs response from target 143 IsSWPrefetch, 144 IsHWPrefetch, 145 IsLlsc, //!< Alpha/MIPS LL or SC access 146 HasData, //!< There is an associated payload 147 IsError, //!< Error response 148 IsPrint, //!< Print state matching address (for debugging) 149 IsFlush, //!< Flush the address from caches 150 NUM_COMMAND_ATTRIBUTES 151 }; 152 153 /** 154 * Structure that defines attributes and other data associated 155 * with a Command. 156 */ 157 struct CommandInfo 158 { 159 /// Set of attribute flags. 160 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 161 /// Corresponding response for requests; InvalidCmd if no 162 /// response is applicable. 163 const Command response; 164 /// String representation (for printing) 165 const std::string str; 166 }; 167 168 /// Array to map Command enum to associated info. 169 static const CommandInfo commandInfo[]; 170 171 private: 172 173 Command cmd; 174 175 bool 176 testCmdAttrib(MemCmd::Attribute attrib) const 177 { 178 return commandInfo[cmd].attributes[attrib] != 0; 179 } 180 181 public: 182 183 bool isRead() const { return testCmdAttrib(IsRead); } 184 bool isWrite() const { return testCmdAttrib(IsWrite); } 185 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); } 186 bool isRequest() const { return testCmdAttrib(IsRequest); } 187 bool isResponse() const { return testCmdAttrib(IsResponse); } 188 bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); } 189 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 190 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 191 192 /** 193 * Check if this particular packet type carries payload data. Note 194 * that this does not reflect if the data pointer of the packet is 195 * valid or not. 196 */ 197 bool hasData() const { return testCmdAttrib(HasData); } 198 bool isLLSC() const { return testCmdAttrib(IsLlsc); } 199 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); } 200 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); } 201 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) || 202 testCmdAttrib(IsHWPrefetch); } 203 bool isError() const { return testCmdAttrib(IsError); } 204 bool isPrint() const { return testCmdAttrib(IsPrint); } 205 bool isFlush() const { return testCmdAttrib(IsFlush); } 206 207 const Command 208 responseCommand() const 209 { 210 return commandInfo[cmd].response; 211 } 212 213 /// Return the string to a cmd given by idx. 214 const std::string &toString() const { return commandInfo[cmd].str; } 215 int toInt() const { return (int)cmd; } 216 217 MemCmd(Command _cmd) : cmd(_cmd) { } 218 MemCmd(int _cmd) : cmd((Command)_cmd) { } 219 MemCmd() : cmd(InvalidCmd) { } 220 221 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); } 222 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); } 223}; 224 225/** 226 * A Packet is used to encapsulate a transfer between two objects in 227 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 228 * single Request travels all the way from the requester to the 229 * ultimate destination and back, possibly being conveyed by several 230 * different Packets along the way.) 231 */ 232class Packet : public Printable 233{ 234 public: 235 typedef uint32_t FlagsType; 236 typedef ::Flags<FlagsType> Flags; 237 238 private: 239 static const FlagsType PUBLIC_FLAGS = 0x00000000; 240 static const FlagsType PRIVATE_FLAGS = 0x00007F0F; 241 static const FlagsType COPY_FLAGS = 0x0000000F; 242 243 static const FlagsType SHARED = 0x00000001; 244 // Special control flags 245 /// Special timing-mode atomic snoop for multi-level coherence. 246 static const FlagsType EXPRESS_SNOOP = 0x00000002; 247 /// Does supplier have exclusive copy? 248 /// Useful for multi-level coherence. 249 static const FlagsType SUPPLY_EXCLUSIVE = 0x00000004; 250 // Snoop response flags 251 static const FlagsType MEM_INHIBIT = 0x00000008; 252 /// Are the 'addr' and 'size' fields valid? 253 static const FlagsType VALID_ADDR = 0x00000100; 254 static const FlagsType VALID_SIZE = 0x00000200; 255 /// Is the data pointer set to a value that shouldn't be freed 256 /// when the packet is destroyed? 257 static const FlagsType STATIC_DATA = 0x00001000; 258 /// The data pointer points to a value that should be freed when 259 /// the packet is destroyed. The pointer is assumed to be pointing 260 /// to an array, and delete [] is consequently called 261 static const FlagsType DYNAMIC_DATA = 0x00002000; 262 /// suppress the error if this packet encounters a functional 263 /// access failure. 264 static const FlagsType SUPPRESS_FUNC_ERROR = 0x00008000; 265 // Signal block present to squash prefetch and cache evict packets 266 // through express snoop flag 267 static const FlagsType BLOCK_CACHED = 0x00010000; 268 269 Flags flags; 270 271 public: 272 typedef MemCmd::Command Command; 273 274 /// The command field of the packet. 275 MemCmd cmd; 276 277 /// A pointer to the original request. 278 const RequestPtr req; 279 280 private: 281 /** 282 * A pointer to the data being transfered. It can be differnt 283 * sizes at each level of the heirarchy so it belongs in the 284 * packet, not request. This may or may not be populated when a 285 * responder recieves the packet. If not populated it memory should 286 * be allocated. 287 */ 288 PacketDataPtr data; 289 290 /// The address of the request. This address could be virtual or 291 /// physical, depending on the system configuration. 292 Addr addr; 293 294 /// True if the request targets the secure memory space. 295 bool _isSecure; 296 297 /// The size of the request or transfer. 298 unsigned size; 299 300 /** 301 * The original value of the command field. Only valid when the 302 * current command field is an error condition; in that case, the 303 * previous contents of the command field are copied here. This 304 * field is *not* set on non-error responses. 305 */ 306 MemCmd origCmd; 307 308 /** 309 * Track the bytes found that satisfy a functional read. 310 */ 311 std::vector<bool> bytesValid; 312 313 public: 314 315 /** 316 * The extra delay from seeing the packet until the header is 317 * transmitted. This delay is used to communicate the crossbar 318 * forwarding latency to the neighbouring object (e.g. a cache) 319 * that actually makes the packet wait. As the delay is relative, 320 * a 32-bit unsigned should be sufficient. 321 */ 322 uint32_t headerDelay; 323 324 /** 325 * The extra pipelining delay from seeing the packet until the end of 326 * payload is transmitted by the component that provided it (if 327 * any). This includes the header delay. Similar to the header 328 * delay, this is used to make up for the fact that the 329 * crossbar does not make the packet wait. As the delay is 330 * relative, a 32-bit unsigned should be sufficient. 331 */ 332 uint32_t payloadDelay; 333 334 /** 335 * A virtual base opaque structure used to hold state associated 336 * with the packet (e.g., an MSHR), specific to a MemObject that 337 * sees the packet. A pointer to this state is returned in the 338 * packet's response so that the MemObject in question can quickly 339 * look up the state needed to process it. A specific subclass 340 * would be derived from this to carry state specific to a 341 * particular sending device. 342 * 343 * As multiple MemObjects may add their SenderState throughout the 344 * memory system, the SenderStates create a stack, where a 345 * MemObject can add a new Senderstate, as long as the 346 * predecessing SenderState is restored when the response comes 347 * back. For this reason, the predecessor should always be 348 * populated with the current SenderState of a packet before 349 * modifying the senderState field in the request packet. 350 */ 351 struct SenderState 352 { 353 SenderState* predecessor; 354 SenderState() : predecessor(NULL) {} 355 virtual ~SenderState() {} 356 }; 357 358 /** 359 * Object used to maintain state of a PrintReq. The senderState 360 * field of a PrintReq should always be of this type. 361 */ 362 class PrintReqState : public SenderState 363 { 364 private: 365 /** 366 * An entry in the label stack. 367 */ 368 struct LabelStackEntry 369 { 370 const std::string label; 371 std::string *prefix; 372 bool labelPrinted; 373 LabelStackEntry(const std::string &_label, std::string *_prefix); 374 }; 375 376 typedef std::list<LabelStackEntry> LabelStack; 377 LabelStack labelStack; 378 379 std::string *curPrefixPtr; 380 381 public: 382 std::ostream &os; 383 const int verbosity; 384 385 PrintReqState(std::ostream &os, int verbosity = 0); 386 ~PrintReqState(); 387 388 /** 389 * Returns the current line prefix. 390 */ 391 const std::string &curPrefix() { return *curPrefixPtr; } 392 393 /** 394 * Push a label onto the label stack, and prepend the given 395 * prefix string onto the current prefix. Labels will only be 396 * printed if an object within the label's scope is printed. 397 */ 398 void pushLabel(const std::string &lbl, 399 const std::string &prefix = " "); 400 401 /** 402 * Pop a label off the label stack. 403 */ 404 void popLabel(); 405 406 /** 407 * Print all of the pending unprinted labels on the 408 * stack. Called by printObj(), so normally not called by 409 * users unless bypassing printObj(). 410 */ 411 void printLabels(); 412 413 /** 414 * Print a Printable object to os, because it matched the 415 * address on a PrintReq. 416 */ 417 void printObj(Printable *obj); 418 }; 419 420 /** 421 * This packet's sender state. Devices should use dynamic_cast<> 422 * to cast to the state appropriate to the sender. The intent of 423 * this variable is to allow a device to attach extra information 424 * to a request. A response packet must return the sender state 425 * that was attached to the original request (even if a new packet 426 * is created). 427 */ 428 SenderState *senderState; 429 430 /** 431 * Push a new sender state to the packet and make the current 432 * sender state the predecessor of the new one. This should be 433 * prefered over direct manipulation of the senderState member 434 * variable. 435 * 436 * @param sender_state SenderState to push at the top of the stack 437 */ 438 void pushSenderState(SenderState *sender_state); 439 440 /** 441 * Pop the top of the state stack and return a pointer to it. This 442 * assumes the current sender state is not NULL. This should be 443 * preferred over direct manipulation of the senderState member 444 * variable. 445 * 446 * @return The current top of the stack 447 */ 448 SenderState *popSenderState(); 449 450 /** 451 * Go through the sender state stack and return the first instance 452 * that is of type T (as determined by a dynamic_cast). If there 453 * is no sender state of type T, NULL is returned. 454 * 455 * @return The topmost state of type T 456 */ 457 template <typename T> 458 T * findNextSenderState() const 459 { 460 T *t = NULL; 461 SenderState* sender_state = senderState; 462 while (t == NULL && sender_state != NULL) { 463 t = dynamic_cast<T*>(sender_state); 464 sender_state = sender_state->predecessor; 465 } 466 return t; 467 } 468 469 /// Return the string name of the cmd field (for debugging and 470 /// tracing). 471 const std::string &cmdString() const { return cmd.toString(); } 472 473 /// Return the index of this command. 474 inline int cmdToIndex() const { return cmd.toInt(); } 475 476 bool isRead() const { return cmd.isRead(); } 477 bool isWrite() const { return cmd.isWrite(); } 478 bool isUpgrade() const { return cmd.isUpgrade(); } 479 bool isRequest() const { return cmd.isRequest(); } 480 bool isResponse() const { return cmd.isResponse(); } 481 bool needsExclusive() const { return cmd.needsExclusive(); } 482 bool needsResponse() const { return cmd.needsResponse(); } 483 bool isInvalidate() const { return cmd.isInvalidate(); } 484 bool hasData() const { return cmd.hasData(); } 485 bool isLLSC() const { return cmd.isLLSC(); } 486 bool isError() const { return cmd.isError(); } 487 bool isPrint() const { return cmd.isPrint(); } 488 bool isFlush() const { return cmd.isFlush(); } 489 490 // Snoop flags 491 void assertMemInhibit() 492 { 493 assert(isRequest()); 494 assert(!flags.isSet(MEM_INHIBIT)); 495 flags.set(MEM_INHIBIT); 496 } 497 bool memInhibitAsserted() const { return flags.isSet(MEM_INHIBIT); } 498 void assertShared() { flags.set(SHARED); } 499 bool sharedAsserted() const { return flags.isSet(SHARED); } 500 501 // Special control flags 502 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 503 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 504 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); } 505 void clearSupplyExclusive() { flags.clear(SUPPLY_EXCLUSIVE); } 506 bool isSupplyExclusive() const { return flags.isSet(SUPPLY_EXCLUSIVE); } 507 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 508 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 509 void setBlockCached() { flags.set(BLOCK_CACHED); } 510 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 511 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 512 513 // Network error conditions... encapsulate them as methods since 514 // their encoding keeps changing (from result field to command 515 // field, etc.) 516 void 517 setBadAddress() 518 { 519 assert(isResponse()); 520 cmd = MemCmd::BadAddressError; 521 } 522 523 bool hadBadAddress() const { return cmd == MemCmd::BadAddressError; } 524 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 525 526 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 527 /** 528 * Update the address of this packet mid-transaction. This is used 529 * by the address mapper to change an already set address to a new 530 * one based on the system configuration. It is intended to remap 531 * an existing address, so it asserts that the current address is 532 * valid. 533 */ 534 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 535 536 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 537 Addr getOffset(int blkSize) const { return getAddr() & (Addr)(blkSize - 1); } 538 539 bool isSecure() const 540 { 541 assert(flags.isSet(VALID_ADDR)); 542 return _isSecure; 543 } 544 545 /** 546 * It has been determined that the SC packet should successfully update 547 * memory. Therefore, convert this SC packet to a normal write. 548 */ 549 void 550 convertScToWrite() 551 { 552 assert(isLLSC()); 553 assert(isWrite()); 554 cmd = MemCmd::WriteReq; 555 } 556 557 /** 558 * When ruby is in use, Ruby will monitor the cache line and thus M5 559 * phys memory should treat LL ops as normal reads. 560 */ 561 void 562 convertLlToRead() 563 { 564 assert(isLLSC()); 565 assert(isRead()); 566 cmd = MemCmd::ReadReq; 567 } 568 569 /** 570 * Constructor. Note that a Request object must be constructed 571 * first, but the Requests's physical address and size fields need 572 * not be valid. The command must be supplied. 573 */ 574 Packet(const RequestPtr _req, MemCmd _cmd) 575 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 576 size(0), headerDelay(0), payloadDelay(0), 577 senderState(NULL) 578 { 579 if (req->hasPaddr()) { 580 addr = req->getPaddr(); 581 flags.set(VALID_ADDR); 582 _isSecure = req->isSecure(); 583 } 584 if (req->hasSize()) { 585 size = req->getSize(); 586 flags.set(VALID_SIZE); 587 } 588 } 589 590 /** 591 * Alternate constructor if you are trying to create a packet with 592 * a request that is for a whole block, not the address from the 593 * req. this allows for overriding the size/addr of the req. 594 */ 595 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize) 596 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 597 headerDelay(0), payloadDelay(0), 598 senderState(NULL) 599 { 600 if (req->hasPaddr()) { 601 addr = req->getPaddr() & ~(_blkSize - 1); 602 flags.set(VALID_ADDR); 603 _isSecure = req->isSecure(); 604 } 605 size = _blkSize; 606 flags.set(VALID_SIZE); 607 } 608 609 /** 610 * Alternate constructor for copying a packet. Copy all fields 611 * *except* if the original packet's data was dynamic, don't copy 612 * that, as we can't guarantee that the new packet's lifetime is 613 * less than that of the original packet. In this case the new 614 * packet should allocate its own data. 615 */ 616 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 617 : cmd(pkt->cmd), req(pkt->req), 618 data(nullptr), 619 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 620 bytesValid(pkt->bytesValid), 621 headerDelay(pkt->headerDelay), 622 payloadDelay(pkt->payloadDelay), 623 senderState(pkt->senderState) 624 { 625 if (!clear_flags) 626 flags.set(pkt->flags & COPY_FLAGS); 627 628 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 629 630 // should we allocate space for data, or not, the express 631 // snoops do not need to carry any data as they only serve to 632 // co-ordinate state changes 633 if (alloc_data) { 634 // even if asked to allocate data, if the original packet 635 // holds static data, then the sender will not be doing 636 // any memcpy on receiving the response, thus we simply 637 // carry the pointer forward 638 if (pkt->flags.isSet(STATIC_DATA)) { 639 data = pkt->data; 640 flags.set(STATIC_DATA); 641 } else { 642 allocate(); 643 } 644 } 645 } 646 647 /** 648 * Generate the appropriate read MemCmd based on the Request flags. 649 */ 650 static MemCmd 651 makeReadCmd(const RequestPtr req) 652 { 653 if (req->isLLSC()) 654 return MemCmd::LoadLockedReq; 655 else if (req->isPrefetch()) 656 return MemCmd::SoftPFReq; 657 else 658 return MemCmd::ReadReq; 659 } 660 661 /** 662 * Generate the appropriate write MemCmd based on the Request flags. 663 */ 664 static MemCmd 665 makeWriteCmd(const RequestPtr req) 666 { 667 if (req->isLLSC()) 668 return MemCmd::StoreCondReq; 669 else if (req->isSwap()) 670 return MemCmd::SwapReq; 671 else 672 return MemCmd::WriteReq; 673 } 674 675 /** 676 * Constructor-like methods that return Packets based on Request objects. 677 * Fine-tune the MemCmd type if it's not a vanilla read or write. 678 */ 679 static PacketPtr 680 createRead(const RequestPtr req) 681 { 682 return new Packet(req, makeReadCmd(req)); 683 } 684 685 static PacketPtr 686 createWrite(const RequestPtr req) 687 { 688 return new Packet(req, makeWriteCmd(req)); 689 } 690 691 /** 692 * clean up packet variables 693 */ 694 ~Packet() 695 { 696 // Delete the request object if this is a request packet which 697 // does not need a response, because the requester will not get 698 // a chance. If the request packet needs a response then the 699 // request will be deleted on receipt of the response 700 // packet. We also make sure to never delete the request for 701 // express snoops, even for cases when responses are not 702 // needed (CleanEvict and Writeback), since the snoop packet 703 // re-uses the same request. 704 if (req && isRequest() && !needsResponse() && 705 !isExpressSnoop()) { 706 delete req; 707 } 708 deleteData(); 709 } 710 711 /** 712 * Take a request packet and modify it in place to be suitable for 713 * returning as a response to that request. 714 */ 715 void 716 makeResponse() 717 { 718 assert(needsResponse()); 719 assert(isRequest()); 720 origCmd = cmd; 721 cmd = cmd.responseCommand(); 722 723 // responses are never express, even if the snoop that 724 // triggered them was 725 flags.clear(EXPRESS_SNOOP); 726 } 727 728 void 729 makeAtomicResponse() 730 { 731 makeResponse(); 732 } 733 734 void 735 makeTimingResponse() 736 { 737 makeResponse(); 738 } 739 740 void 741 setFunctionalResponseStatus(bool success) 742 { 743 if (!success) { 744 if (isWrite()) { 745 cmd = MemCmd::FunctionalWriteError; 746 } else { 747 cmd = MemCmd::FunctionalReadError; 748 } 749 } 750 } 751 752 void 753 setSize(unsigned size) 754 { 755 assert(!flags.isSet(VALID_SIZE)); 756 757 this->size = size; 758 flags.set(VALID_SIZE); 759 } 760 761 762 /** 763 * Set the data pointer to the following value that should not be 764 * freed. Static data allows us to do a single memcpy even if 765 * multiple packets are required to get from source to destination 766 * and back. In essence the pointer is set calling dataStatic on 767 * the original packet, and whenever this packet is copied and 768 * forwarded the same pointer is passed on. When a packet 769 * eventually reaches the destination holding the data, it is 770 * copied once into the location originally set. On the way back 771 * to the source, no copies are necessary. 772 */ 773 template <typename T> 774 void 775 dataStatic(T *p) 776 { 777 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 778 data = (PacketDataPtr)p; 779 flags.set(STATIC_DATA); 780 } 781 782 /** 783 * Set the data pointer to the following value that should not be 784 * freed. This version of the function allows the pointer passed 785 * to us to be const. To avoid issues down the line we cast the 786 * constness away, the alternative would be to keep both a const 787 * and non-const data pointer and cleverly choose between 788 * them. Note that this is only allowed for static data. 789 */ 790 template <typename T> 791 void 792 dataStaticConst(const T *p) 793 { 794 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 795 data = const_cast<PacketDataPtr>(p); 796 flags.set(STATIC_DATA); 797 } 798 799 /** 800 * Set the data pointer to a value that should have delete [] 801 * called on it. Dynamic data is local to this packet, and as the 802 * packet travels from source to destination, forwarded packets 803 * will allocate their own data. When a packet reaches the final 804 * destination it will populate the dynamic data of that specific 805 * packet, and on the way back towards the source, memcpy will be 806 * invoked in every step where a new packet was created e.g. in 807 * the caches. Ultimately when the response reaches the source a 808 * final memcpy is needed to extract the data from the packet 809 * before it is deallocated. 810 */ 811 template <typename T> 812 void 813 dataDynamic(T *p) 814 { 815 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 816 data = (PacketDataPtr)p; 817 flags.set(DYNAMIC_DATA); 818 } 819 820 /** 821 * get a pointer to the data ptr. 822 */ 823 template <typename T> 824 T* 825 getPtr() 826 { 827 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 828 return (T*)data; 829 } 830 831 template <typename T> 832 const T* 833 getConstPtr() const 834 { 835 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 836 return (const T*)data; 837 } 838 839 /** 840 * return the value of what is pointed to in the packet. 841 */ 842 template <typename T> 843 T get() const; 844 845 /** 846 * set the value in the data pointer to v. 847 */ 848 template <typename T> 849 void set(T v); 850 851 /** 852 * Copy data into the packet from the provided pointer. 853 */ 854 void 855 setData(const uint8_t *p) 856 { 857 // we should never be copying data onto itself, which means we 858 // must idenfity packets with static data, as they carry the 859 // same pointer from source to destination and back 860 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 861 862 if (p != getPtr<uint8_t>()) 863 // for packet with allocated dynamic data, we copy data from 864 // one to the other, e.g. a forwarded response to a response 865 std::memcpy(getPtr<uint8_t>(), p, getSize()); 866 } 867 868 /** 869 * Copy data into the packet from the provided block pointer, 870 * which is aligned to the given block size. 871 */ 872 void 873 setDataFromBlock(const uint8_t *blk_data, int blkSize) 874 { 875 setData(blk_data + getOffset(blkSize)); 876 } 877 878 /** 879 * Copy data from the packet to the provided block pointer, which 880 * is aligned to the given block size. 881 */ 882 void 883 writeData(uint8_t *p) const 884 { 885 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 886 } 887 888 /** 889 * Copy data from the packet to the memory at the provided pointer. 890 */ 891 void 892 writeDataToBlock(uint8_t *blk_data, int blkSize) const 893 { 894 writeData(blk_data + getOffset(blkSize)); 895 } 896 897 /** 898 * delete the data pointed to in the data pointer. Ok to call to 899 * matter how data was allocted. 900 */ 901 void 902 deleteData() 903 { 904 if (flags.isSet(DYNAMIC_DATA)) 905 delete [] data; 906 907 flags.clear(STATIC_DATA|DYNAMIC_DATA); 908 data = NULL; 909 } 910 911 /** Allocate memory for the packet. */ 912 void 913 allocate() 914 { 915 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 916 flags.set(DYNAMIC_DATA); 917 data = new uint8_t[getSize()]; 918 } 919 920 /** 921 * Check a functional request against a memory value stored in 922 * another packet (i.e. an in-transit request or 923 * response). Returns true if the current packet is a read, and 924 * the other packet provides the data, which is then copied to the 925 * current packet. If the current packet is a write, and the other 926 * packet intersects this one, then we update the data 927 * accordingly. 928 */ 929 bool 930 checkFunctional(PacketPtr other) 931 { 932 // all packets that are carrying a payload should have a valid 933 // data pointer 934 return checkFunctional(other, other->getAddr(), other->isSecure(), 935 other->getSize(), 936 other->hasData() ? 937 other->getPtr<uint8_t>() : NULL); 938 } 939 940 /** 941 * Is this request notification of a clean or dirty eviction from the cache. 942 **/ 943 bool 944 evictingBlock() const 945 { 946 return (cmd == MemCmd::Writeback || 947 cmd == MemCmd::CleanEvict); 948 } 949 950 /** 951 * Does the request need to check for cached copies of the same block 952 * in the memory hierarchy above. 953 **/ 954 bool 955 mustCheckAbove() const 956 { 957 return (cmd == MemCmd::HardPFReq || 958 evictingBlock()); 959 } 960 961 /** 962 * Check a functional request against a memory value represented 963 * by a base/size pair and an associated data array. If the 964 * current packet is a read, it may be satisfied by the memory 965 * value. If the current packet is a write, it may update the 966 * memory value. 967 */ 968 bool 969 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 970 uint8_t *_data); 971 972 /** 973 * Push label for PrintReq (safe to call unconditionally). 974 */ 975 void 976 pushLabel(const std::string &lbl) 977 { 978 if (isPrint()) 979 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 980 } 981 982 /** 983 * Pop label for PrintReq (safe to call unconditionally). 984 */ 985 void 986 popLabel() 987 { 988 if (isPrint()) 989 safe_cast<PrintReqState*>(senderState)->popLabel(); 990 } 991 992 void print(std::ostream &o, int verbosity = 0, 993 const std::string &prefix = "") const; 994 995 /** 996 * A no-args wrapper of print(std::ostream...) 997 * meant to be invoked from DPRINTFs 998 * avoiding string overheads in fast mode 999 * @return string with the request's type and start<->end addresses 1000 */ 1001 std::string print() const; 1002}; 1003 1004#endif //__MEM_PACKET_HH 1005