packet.hh revision 11127
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) 2010,2015 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 ReleaseReq, 114 ReleaseResp, 115 AcquireReq, 116 AcquireResp, 117 // Error responses 118 // @TODO these should be classified as responses rather than 119 // requests; coding them as requests initially for backwards 120 // compatibility 121 InvalidDestError, // packet dest field invalid 122 BadAddressError, // memory address invalid 123 FunctionalReadError, // unable to fulfill functional read 124 FunctionalWriteError, // unable to fulfill functional write 125 // Fake simulator-only commands 126 PrintReq, // Print state matching address 127 FlushReq, //request for a cache flush 128 InvalidateReq, // request for address to be invalidated 129 InvalidateResp, 130 NUM_MEM_CMDS 131 }; 132 133 private: 134 /** 135 * List of command attributes. 136 */ 137 enum Attribute 138 { 139 IsRead, //!< Data flows from responder to requester 140 IsWrite, //!< Data flows from requester to responder 141 IsUpgrade, 142 IsInvalidate, 143 NeedsExclusive, //!< Requires exclusive copy to complete in-cache 144 IsRequest, //!< Issued by requester 145 IsResponse, //!< Issue by responder 146 NeedsResponse, //!< Requester needs response from target 147 IsSWPrefetch, 148 IsHWPrefetch, 149 IsLlsc, //!< Alpha/MIPS LL or SC access 150 HasData, //!< There is an associated payload 151 IsError, //!< Error response 152 IsPrint, //!< Print state matching address (for debugging) 153 IsFlush, //!< Flush the address from caches 154 NUM_COMMAND_ATTRIBUTES 155 }; 156 157 /** 158 * Structure that defines attributes and other data associated 159 * with a Command. 160 */ 161 struct CommandInfo 162 { 163 /// Set of attribute flags. 164 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 165 /// Corresponding response for requests; InvalidCmd if no 166 /// response is applicable. 167 const Command response; 168 /// String representation (for printing) 169 const std::string str; 170 }; 171 172 /// Array to map Command enum to associated info. 173 static const CommandInfo commandInfo[]; 174 175 private: 176 177 Command cmd; 178 179 bool 180 testCmdAttrib(MemCmd::Attribute attrib) const 181 { 182 return commandInfo[cmd].attributes[attrib] != 0; 183 } 184 185 public: 186 187 bool isRead() const { return testCmdAttrib(IsRead); } 188 bool isWrite() const { return testCmdAttrib(IsWrite); } 189 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); } 190 bool isRequest() const { return testCmdAttrib(IsRequest); } 191 bool isResponse() const { return testCmdAttrib(IsResponse); } 192 bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); } 193 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 194 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 195 196 /** 197 * Check if this particular packet type carries payload data. Note 198 * that this does not reflect if the data pointer of the packet is 199 * valid or not. 200 */ 201 bool hasData() const { return testCmdAttrib(HasData); } 202 bool isLLSC() const { return testCmdAttrib(IsLlsc); } 203 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); } 204 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); } 205 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) || 206 testCmdAttrib(IsHWPrefetch); } 207 bool isError() const { return testCmdAttrib(IsError); } 208 bool isPrint() const { return testCmdAttrib(IsPrint); } 209 bool isFlush() const { return testCmdAttrib(IsFlush); } 210 211 const Command 212 responseCommand() const 213 { 214 return commandInfo[cmd].response; 215 } 216 217 /// Return the string to a cmd given by idx. 218 const std::string &toString() const { return commandInfo[cmd].str; } 219 int toInt() const { return (int)cmd; } 220 221 MemCmd(Command _cmd) : cmd(_cmd) { } 222 MemCmd(int _cmd) : cmd((Command)_cmd) { } 223 MemCmd() : cmd(InvalidCmd) { } 224 225 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); } 226 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); } 227}; 228 229/** 230 * A Packet is used to encapsulate a transfer between two objects in 231 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 232 * single Request travels all the way from the requester to the 233 * ultimate destination and back, possibly being conveyed by several 234 * different Packets along the way.) 235 */ 236class Packet : public Printable 237{ 238 public: 239 typedef uint32_t FlagsType; 240 typedef ::Flags<FlagsType> Flags; 241 242 private: 243 244 enum : FlagsType { 245 // Flags to transfer across when copying a packet 246 COPY_FLAGS = 0x0000000F, 247 248 SHARED = 0x00000001, 249 // Special control flags 250 /// Special timing-mode atomic snoop for multi-level coherence. 251 EXPRESS_SNOOP = 0x00000002, 252 /// Does supplier have exclusive copy? 253 /// Useful for multi-level coherence. 254 SUPPLY_EXCLUSIVE = 0x00000004, 255 // Snoop response flags 256 MEM_INHIBIT = 0x00000008, 257 258 /// Are the 'addr' and 'size' fields valid? 259 VALID_ADDR = 0x00000100, 260 VALID_SIZE = 0x00000200, 261 262 /// Is the data pointer set to a value that shouldn't be freed 263 /// when the packet is destroyed? 264 STATIC_DATA = 0x00001000, 265 /// The data pointer points to a value that should be freed when 266 /// the packet is destroyed. The pointer is assumed to be pointing 267 /// to an array, and delete [] is consequently called 268 DYNAMIC_DATA = 0x00002000, 269 270 /// suppress the error if this packet encounters a functional 271 /// access failure. 272 SUPPRESS_FUNC_ERROR = 0x00008000, 273 274 // Signal block present to squash prefetch and cache evict packets 275 // through express snoop flag 276 BLOCK_CACHED = 0x00010000 277 }; 278 279 Flags flags; 280 281 public: 282 typedef MemCmd::Command Command; 283 284 /// The command field of the packet. 285 MemCmd cmd; 286 287 /// A pointer to the original request. 288 const RequestPtr req; 289 290 private: 291 /** 292 * A pointer to the data being transfered. It can be differnt 293 * sizes at each level of the heirarchy so it belongs in the 294 * packet, not request. This may or may not be populated when a 295 * responder recieves the packet. If not populated it memory should 296 * be allocated. 297 */ 298 PacketDataPtr data; 299 300 /// The address of the request. This address could be virtual or 301 /// physical, depending on the system configuration. 302 Addr addr; 303 304 /// True if the request targets the secure memory space. 305 bool _isSecure; 306 307 /// The size of the request or transfer. 308 unsigned size; 309 310 /** 311 * Track the bytes found that satisfy a functional read. 312 */ 313 std::vector<bool> bytesValid; 314 315 public: 316 317 /** 318 * The extra delay from seeing the packet until the header is 319 * transmitted. This delay is used to communicate the crossbar 320 * forwarding latency to the neighbouring object (e.g. a cache) 321 * that actually makes the packet wait. As the delay is relative, 322 * a 32-bit unsigned should be sufficient. 323 */ 324 uint32_t headerDelay; 325 326 /** 327 * Keep track of the extra delay incurred by snooping upwards 328 * before sending a request down the memory system. This is used 329 * by the coherent crossbar to account for the additional request 330 * delay. 331 */ 332 uint32_t snoopDelay; 333 334 /** 335 * The extra pipelining delay from seeing the packet until the end of 336 * payload is transmitted by the component that provided it (if 337 * any). This includes the header delay. Similar to the header 338 * delay, this is used to make up for the fact that the 339 * crossbar does not make the packet wait. As the delay is 340 * relative, a 32-bit unsigned should be sufficient. 341 */ 342 uint32_t payloadDelay; 343 344 /** 345 * A virtual base opaque structure used to hold state associated 346 * with the packet (e.g., an MSHR), specific to a MemObject that 347 * sees the packet. A pointer to this state is returned in the 348 * packet's response so that the MemObject in question can quickly 349 * look up the state needed to process it. A specific subclass 350 * would be derived from this to carry state specific to a 351 * particular sending device. 352 * 353 * As multiple MemObjects may add their SenderState throughout the 354 * memory system, the SenderStates create a stack, where a 355 * MemObject can add a new Senderstate, as long as the 356 * predecessing SenderState is restored when the response comes 357 * back. For this reason, the predecessor should always be 358 * populated with the current SenderState of a packet before 359 * modifying the senderState field in the request packet. 360 */ 361 struct SenderState 362 { 363 SenderState* predecessor; 364 SenderState() : predecessor(NULL) {} 365 virtual ~SenderState() {} 366 }; 367 368 /** 369 * Object used to maintain state of a PrintReq. The senderState 370 * field of a PrintReq should always be of this type. 371 */ 372 class PrintReqState : public SenderState 373 { 374 private: 375 /** 376 * An entry in the label stack. 377 */ 378 struct LabelStackEntry 379 { 380 const std::string label; 381 std::string *prefix; 382 bool labelPrinted; 383 LabelStackEntry(const std::string &_label, std::string *_prefix); 384 }; 385 386 typedef std::list<LabelStackEntry> LabelStack; 387 LabelStack labelStack; 388 389 std::string *curPrefixPtr; 390 391 public: 392 std::ostream &os; 393 const int verbosity; 394 395 PrintReqState(std::ostream &os, int verbosity = 0); 396 ~PrintReqState(); 397 398 /** 399 * Returns the current line prefix. 400 */ 401 const std::string &curPrefix() { return *curPrefixPtr; } 402 403 /** 404 * Push a label onto the label stack, and prepend the given 405 * prefix string onto the current prefix. Labels will only be 406 * printed if an object within the label's scope is printed. 407 */ 408 void pushLabel(const std::string &lbl, 409 const std::string &prefix = " "); 410 411 /** 412 * Pop a label off the label stack. 413 */ 414 void popLabel(); 415 416 /** 417 * Print all of the pending unprinted labels on the 418 * stack. Called by printObj(), so normally not called by 419 * users unless bypassing printObj(). 420 */ 421 void printLabels(); 422 423 /** 424 * Print a Printable object to os, because it matched the 425 * address on a PrintReq. 426 */ 427 void printObj(Printable *obj); 428 }; 429 430 /** 431 * This packet's sender state. Devices should use dynamic_cast<> 432 * to cast to the state appropriate to the sender. The intent of 433 * this variable is to allow a device to attach extra information 434 * to a request. A response packet must return the sender state 435 * that was attached to the original request (even if a new packet 436 * is created). 437 */ 438 SenderState *senderState; 439 440 /** 441 * Push a new sender state to the packet and make the current 442 * sender state the predecessor of the new one. This should be 443 * prefered over direct manipulation of the senderState member 444 * variable. 445 * 446 * @param sender_state SenderState to push at the top of the stack 447 */ 448 void pushSenderState(SenderState *sender_state); 449 450 /** 451 * Pop the top of the state stack and return a pointer to it. This 452 * assumes the current sender state is not NULL. This should be 453 * preferred over direct manipulation of the senderState member 454 * variable. 455 * 456 * @return The current top of the stack 457 */ 458 SenderState *popSenderState(); 459 460 /** 461 * Go through the sender state stack and return the first instance 462 * that is of type T (as determined by a dynamic_cast). If there 463 * is no sender state of type T, NULL is returned. 464 * 465 * @return The topmost state of type T 466 */ 467 template <typename T> 468 T * findNextSenderState() const 469 { 470 T *t = NULL; 471 SenderState* sender_state = senderState; 472 while (t == NULL && sender_state != NULL) { 473 t = dynamic_cast<T*>(sender_state); 474 sender_state = sender_state->predecessor; 475 } 476 return t; 477 } 478 479 /// Return the string name of the cmd field (for debugging and 480 /// tracing). 481 const std::string &cmdString() const { return cmd.toString(); } 482 483 /// Return the index of this command. 484 inline int cmdToIndex() const { return cmd.toInt(); } 485 486 bool isRead() const { return cmd.isRead(); } 487 bool isWrite() const { return cmd.isWrite(); } 488 bool isUpgrade() const { return cmd.isUpgrade(); } 489 bool isRequest() const { return cmd.isRequest(); } 490 bool isResponse() const { return cmd.isResponse(); } 491 bool needsExclusive() const { return cmd.needsExclusive(); } 492 bool needsResponse() const { return cmd.needsResponse(); } 493 bool isInvalidate() const { return cmd.isInvalidate(); } 494 bool hasData() const { return cmd.hasData(); } 495 bool isLLSC() const { return cmd.isLLSC(); } 496 bool isError() const { return cmd.isError(); } 497 bool isPrint() const { return cmd.isPrint(); } 498 bool isFlush() const { return cmd.isFlush(); } 499 500 // Snoop flags 501 void assertMemInhibit() 502 { 503 assert(isRequest()); 504 assert(!flags.isSet(MEM_INHIBIT)); 505 flags.set(MEM_INHIBIT); 506 } 507 bool memInhibitAsserted() const { return flags.isSet(MEM_INHIBIT); } 508 void assertShared() { flags.set(SHARED); } 509 bool sharedAsserted() const { return flags.isSet(SHARED); } 510 511 // Special control flags 512 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 513 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 514 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); } 515 bool isSupplyExclusive() const { return flags.isSet(SUPPLY_EXCLUSIVE); } 516 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 517 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 518 void setBlockCached() { flags.set(BLOCK_CACHED); } 519 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 520 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 521 522 // Network error conditions... encapsulate them as methods since 523 // their encoding keeps changing (from result field to command 524 // field, etc.) 525 void 526 setBadAddress() 527 { 528 assert(isResponse()); 529 cmd = MemCmd::BadAddressError; 530 } 531 532 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 533 534 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 535 /** 536 * Update the address of this packet mid-transaction. This is used 537 * by the address mapper to change an already set address to a new 538 * one based on the system configuration. It is intended to remap 539 * an existing address, so it asserts that the current address is 540 * valid. 541 */ 542 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 543 544 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 545 546 Addr getOffset(unsigned int blk_size) const 547 { 548 return getAddr() & Addr(blk_size - 1); 549 } 550 551 Addr getBlockAddr(unsigned int blk_size) const 552 { 553 return getAddr() & ~(Addr(blk_size - 1)); 554 } 555 556 bool isSecure() const 557 { 558 assert(flags.isSet(VALID_ADDR)); 559 return _isSecure; 560 } 561 562 /** 563 * It has been determined that the SC packet should successfully update 564 * memory. Therefore, convert this SC packet to a normal write. 565 */ 566 void 567 convertScToWrite() 568 { 569 assert(isLLSC()); 570 assert(isWrite()); 571 cmd = MemCmd::WriteReq; 572 } 573 574 /** 575 * When ruby is in use, Ruby will monitor the cache line and the 576 * phys memory should treat LL ops as normal reads. 577 */ 578 void 579 convertLlToRead() 580 { 581 assert(isLLSC()); 582 assert(isRead()); 583 cmd = MemCmd::ReadReq; 584 } 585 586 /** 587 * Constructor. Note that a Request object must be constructed 588 * first, but the Requests's physical address and size fields need 589 * not be valid. The command must be supplied. 590 */ 591 Packet(const RequestPtr _req, MemCmd _cmd) 592 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 593 size(0), headerDelay(0), snoopDelay(0), payloadDelay(0), 594 senderState(NULL) 595 { 596 if (req->hasPaddr()) { 597 addr = req->getPaddr(); 598 flags.set(VALID_ADDR); 599 _isSecure = req->isSecure(); 600 } 601 if (req->hasSize()) { 602 size = req->getSize(); 603 flags.set(VALID_SIZE); 604 } 605 } 606 607 /** 608 * Alternate constructor if you are trying to create a packet with 609 * a request that is for a whole block, not the address from the 610 * req. this allows for overriding the size/addr of the req. 611 */ 612 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize) 613 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 614 headerDelay(0), snoopDelay(0), payloadDelay(0), 615 senderState(NULL) 616 { 617 if (req->hasPaddr()) { 618 addr = req->getPaddr() & ~(_blkSize - 1); 619 flags.set(VALID_ADDR); 620 _isSecure = req->isSecure(); 621 } 622 size = _blkSize; 623 flags.set(VALID_SIZE); 624 } 625 626 /** 627 * Alternate constructor for copying a packet. Copy all fields 628 * *except* if the original packet's data was dynamic, don't copy 629 * that, as we can't guarantee that the new packet's lifetime is 630 * less than that of the original packet. In this case the new 631 * packet should allocate its own data. 632 */ 633 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 634 : cmd(pkt->cmd), req(pkt->req), 635 data(nullptr), 636 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 637 bytesValid(pkt->bytesValid), 638 headerDelay(pkt->headerDelay), 639 snoopDelay(0), 640 payloadDelay(pkt->payloadDelay), 641 senderState(pkt->senderState) 642 { 643 if (!clear_flags) 644 flags.set(pkt->flags & COPY_FLAGS); 645 646 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 647 648 // should we allocate space for data, or not, the express 649 // snoops do not need to carry any data as they only serve to 650 // co-ordinate state changes 651 if (alloc_data) { 652 // even if asked to allocate data, if the original packet 653 // holds static data, then the sender will not be doing 654 // any memcpy on receiving the response, thus we simply 655 // carry the pointer forward 656 if (pkt->flags.isSet(STATIC_DATA)) { 657 data = pkt->data; 658 flags.set(STATIC_DATA); 659 } else { 660 allocate(); 661 } 662 } 663 } 664 665 /** 666 * Generate the appropriate read MemCmd based on the Request flags. 667 */ 668 static MemCmd 669 makeReadCmd(const RequestPtr req) 670 { 671 if (req->isLLSC()) 672 return MemCmd::LoadLockedReq; 673 else if (req->isPrefetch()) 674 return MemCmd::SoftPFReq; 675 else 676 return MemCmd::ReadReq; 677 } 678 679 /** 680 * Generate the appropriate write MemCmd based on the Request flags. 681 */ 682 static MemCmd 683 makeWriteCmd(const RequestPtr req) 684 { 685 if (req->isLLSC()) 686 return MemCmd::StoreCondReq; 687 else if (req->isSwap()) 688 return MemCmd::SwapReq; 689 else 690 return MemCmd::WriteReq; 691 } 692 693 /** 694 * Constructor-like methods that return Packets based on Request objects. 695 * Fine-tune the MemCmd type if it's not a vanilla read or write. 696 */ 697 static PacketPtr 698 createRead(const RequestPtr req) 699 { 700 return new Packet(req, makeReadCmd(req)); 701 } 702 703 static PacketPtr 704 createWrite(const RequestPtr req) 705 { 706 return new Packet(req, makeWriteCmd(req)); 707 } 708 709 /** 710 * clean up packet variables 711 */ 712 ~Packet() 713 { 714 // Delete the request object if this is a request packet which 715 // does not need a response, because the requester will not get 716 // a chance. If the request packet needs a response then the 717 // request will be deleted on receipt of the response 718 // packet. We also make sure to never delete the request for 719 // express snoops, even for cases when responses are not 720 // needed (CleanEvict and Writeback), since the snoop packet 721 // re-uses the same request. 722 if (req && isRequest() && !needsResponse() && 723 !isExpressSnoop()) { 724 delete req; 725 } 726 deleteData(); 727 } 728 729 /** 730 * Take a request packet and modify it in place to be suitable for 731 * returning as a response to that request. 732 */ 733 void 734 makeResponse() 735 { 736 assert(needsResponse()); 737 assert(isRequest()); 738 cmd = cmd.responseCommand(); 739 740 // responses are never express, even if the snoop that 741 // triggered them was 742 flags.clear(EXPRESS_SNOOP); 743 } 744 745 void 746 makeAtomicResponse() 747 { 748 makeResponse(); 749 } 750 751 void 752 makeTimingResponse() 753 { 754 makeResponse(); 755 } 756 757 void 758 setFunctionalResponseStatus(bool success) 759 { 760 if (!success) { 761 if (isWrite()) { 762 cmd = MemCmd::FunctionalWriteError; 763 } else { 764 cmd = MemCmd::FunctionalReadError; 765 } 766 } 767 } 768 769 void 770 setSize(unsigned size) 771 { 772 assert(!flags.isSet(VALID_SIZE)); 773 774 this->size = size; 775 flags.set(VALID_SIZE); 776 } 777 778 779 public: 780 /** 781 * @{ 782 * @name Data accessor mehtods 783 */ 784 785 /** 786 * Set the data pointer to the following value that should not be 787 * freed. Static data allows us to do a single memcpy even if 788 * multiple packets are required to get from source to destination 789 * and back. In essence the pointer is set calling dataStatic on 790 * the original packet, and whenever this packet is copied and 791 * forwarded the same pointer is passed on. When a packet 792 * eventually reaches the destination holding the data, it is 793 * copied once into the location originally set. On the way back 794 * to the source, no copies are necessary. 795 */ 796 template <typename T> 797 void 798 dataStatic(T *p) 799 { 800 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 801 data = (PacketDataPtr)p; 802 flags.set(STATIC_DATA); 803 } 804 805 /** 806 * Set the data pointer to the following value that should not be 807 * freed. This version of the function allows the pointer passed 808 * to us to be const. To avoid issues down the line we cast the 809 * constness away, the alternative would be to keep both a const 810 * and non-const data pointer and cleverly choose between 811 * them. Note that this is only allowed for static data. 812 */ 813 template <typename T> 814 void 815 dataStaticConst(const T *p) 816 { 817 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 818 data = const_cast<PacketDataPtr>(p); 819 flags.set(STATIC_DATA); 820 } 821 822 /** 823 * Set the data pointer to a value that should have delete [] 824 * called on it. Dynamic data is local to this packet, and as the 825 * packet travels from source to destination, forwarded packets 826 * will allocate their own data. When a packet reaches the final 827 * destination it will populate the dynamic data of that specific 828 * packet, and on the way back towards the source, memcpy will be 829 * invoked in every step where a new packet was created e.g. in 830 * the caches. Ultimately when the response reaches the source a 831 * final memcpy is needed to extract the data from the packet 832 * before it is deallocated. 833 */ 834 template <typename T> 835 void 836 dataDynamic(T *p) 837 { 838 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 839 data = (PacketDataPtr)p; 840 flags.set(DYNAMIC_DATA); 841 } 842 843 /** 844 * get a pointer to the data ptr. 845 */ 846 template <typename T> 847 T* 848 getPtr() 849 { 850 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 851 return (T*)data; 852 } 853 854 template <typename T> 855 const T* 856 getConstPtr() const 857 { 858 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 859 return (const T*)data; 860 } 861 862 /** 863 * Get the data in the packet byte swapped from big endian to 864 * host endian. 865 */ 866 template <typename T> 867 T getBE() const; 868 869 /** 870 * Get the data in the packet byte swapped from little endian to 871 * host endian. 872 */ 873 template <typename T> 874 T getLE() const; 875 876 /** 877 * Get the data in the packet byte swapped from the specified 878 * endianness. 879 */ 880 template <typename T> 881 T get(ByteOrder endian) const; 882 883 /** 884 * Get the data in the packet byte swapped from guest to host 885 * endian. 886 */ 887 template <typename T> 888 T get() const; 889 890 /** Set the value in the data pointer to v as big endian. */ 891 template <typename T> 892 void setBE(T v); 893 894 /** Set the value in the data pointer to v as little endian. */ 895 template <typename T> 896 void setLE(T v); 897 898 /** 899 * Set the value in the data pointer to v using the specified 900 * endianness. 901 */ 902 template <typename T> 903 void set(T v, ByteOrder endian); 904 905 /** Set the value in the data pointer to v as guest endian. */ 906 template <typename T> 907 void set(T v); 908 909 /** 910 * Copy data into the packet from the provided pointer. 911 */ 912 void 913 setData(const uint8_t *p) 914 { 915 // we should never be copying data onto itself, which means we 916 // must idenfity packets with static data, as they carry the 917 // same pointer from source to destination and back 918 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 919 920 if (p != getPtr<uint8_t>()) 921 // for packet with allocated dynamic data, we copy data from 922 // one to the other, e.g. a forwarded response to a response 923 std::memcpy(getPtr<uint8_t>(), p, getSize()); 924 } 925 926 /** 927 * Copy data into the packet from the provided block pointer, 928 * which is aligned to the given block size. 929 */ 930 void 931 setDataFromBlock(const uint8_t *blk_data, int blkSize) 932 { 933 setData(blk_data + getOffset(blkSize)); 934 } 935 936 /** 937 * Copy data from the packet to the provided block pointer, which 938 * is aligned to the given block size. 939 */ 940 void 941 writeData(uint8_t *p) const 942 { 943 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 944 } 945 946 /** 947 * Copy data from the packet to the memory at the provided pointer. 948 */ 949 void 950 writeDataToBlock(uint8_t *blk_data, int blkSize) const 951 { 952 writeData(blk_data + getOffset(blkSize)); 953 } 954 955 /** 956 * delete the data pointed to in the data pointer. Ok to call to 957 * matter how data was allocted. 958 */ 959 void 960 deleteData() 961 { 962 if (flags.isSet(DYNAMIC_DATA)) 963 delete [] data; 964 965 flags.clear(STATIC_DATA|DYNAMIC_DATA); 966 data = NULL; 967 } 968 969 /** Allocate memory for the packet. */ 970 void 971 allocate() 972 { 973 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 974 flags.set(DYNAMIC_DATA); 975 data = new uint8_t[getSize()]; 976 } 977 978 /** @} */ 979 980 private: // Private data accessor methods 981 /** Get the data in the packet without byte swapping. */ 982 template <typename T> 983 T getRaw() const; 984 985 /** Set the value in the data pointer to v without byte swapping. */ 986 template <typename T> 987 void setRaw(T v); 988 989 public: 990 /** 991 * Check a functional request against a memory value stored in 992 * another packet (i.e. an in-transit request or 993 * response). Returns true if the current packet is a read, and 994 * the other packet provides the data, which is then copied to the 995 * current packet. If the current packet is a write, and the other 996 * packet intersects this one, then we update the data 997 * accordingly. 998 */ 999 bool 1000 checkFunctional(PacketPtr other) 1001 { 1002 // all packets that are carrying a payload should have a valid 1003 // data pointer 1004 return checkFunctional(other, other->getAddr(), other->isSecure(), 1005 other->getSize(), 1006 other->hasData() ? 1007 other->getPtr<uint8_t>() : NULL); 1008 } 1009 1010 /** 1011 * Is this request notification of a clean or dirty eviction from the cache. 1012 **/ 1013 bool 1014 evictingBlock() const 1015 { 1016 return (cmd == MemCmd::Writeback || 1017 cmd == MemCmd::CleanEvict); 1018 } 1019 1020 /** 1021 * Does the request need to check for cached copies of the same block 1022 * in the memory hierarchy above. 1023 **/ 1024 bool 1025 mustCheckAbove() const 1026 { 1027 return (cmd == MemCmd::HardPFReq || 1028 evictingBlock()); 1029 } 1030 1031 /** 1032 * Check a functional request against a memory value represented 1033 * by a base/size pair and an associated data array. If the 1034 * current packet is a read, it may be satisfied by the memory 1035 * value. If the current packet is a write, it may update the 1036 * memory value. 1037 */ 1038 bool 1039 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 1040 uint8_t *_data); 1041 1042 /** 1043 * Push label for PrintReq (safe to call unconditionally). 1044 */ 1045 void 1046 pushLabel(const std::string &lbl) 1047 { 1048 if (isPrint()) 1049 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 1050 } 1051 1052 /** 1053 * Pop label for PrintReq (safe to call unconditionally). 1054 */ 1055 void 1056 popLabel() 1057 { 1058 if (isPrint()) 1059 safe_cast<PrintReqState*>(senderState)->popLabel(); 1060 } 1061 1062 void print(std::ostream &o, int verbosity = 0, 1063 const std::string &prefix = "") const; 1064 1065 /** 1066 * A no-args wrapper of print(std::ostream...) 1067 * meant to be invoked from DPRINTFs 1068 * avoiding string overheads in fast mode 1069 * @return string with the request's type and start<->end addresses 1070 */ 1071 std::string print() const; 1072}; 1073 1074#endif //__MEM_PACKET_HH 1075