packet.hh revision 11057
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 * The extra pipelining delay from seeing the packet until the end of 328 * payload is transmitted by the component that provided it (if 329 * any). This includes the header delay. Similar to the header 330 * delay, this is used to make up for the fact that the 331 * crossbar does not make the packet wait. As the delay is 332 * relative, a 32-bit unsigned should be sufficient. 333 */ 334 uint32_t payloadDelay; 335 336 /** 337 * A virtual base opaque structure used to hold state associated 338 * with the packet (e.g., an MSHR), specific to a MemObject that 339 * sees the packet. A pointer to this state is returned in the 340 * packet's response so that the MemObject in question can quickly 341 * look up the state needed to process it. A specific subclass 342 * would be derived from this to carry state specific to a 343 * particular sending device. 344 * 345 * As multiple MemObjects may add their SenderState throughout the 346 * memory system, the SenderStates create a stack, where a 347 * MemObject can add a new Senderstate, as long as the 348 * predecessing SenderState is restored when the response comes 349 * back. For this reason, the predecessor should always be 350 * populated with the current SenderState of a packet before 351 * modifying the senderState field in the request packet. 352 */ 353 struct SenderState 354 { 355 SenderState* predecessor; 356 SenderState() : predecessor(NULL) {} 357 virtual ~SenderState() {} 358 }; 359 360 /** 361 * Object used to maintain state of a PrintReq. The senderState 362 * field of a PrintReq should always be of this type. 363 */ 364 class PrintReqState : public SenderState 365 { 366 private: 367 /** 368 * An entry in the label stack. 369 */ 370 struct LabelStackEntry 371 { 372 const std::string label; 373 std::string *prefix; 374 bool labelPrinted; 375 LabelStackEntry(const std::string &_label, std::string *_prefix); 376 }; 377 378 typedef std::list<LabelStackEntry> LabelStack; 379 LabelStack labelStack; 380 381 std::string *curPrefixPtr; 382 383 public: 384 std::ostream &os; 385 const int verbosity; 386 387 PrintReqState(std::ostream &os, int verbosity = 0); 388 ~PrintReqState(); 389 390 /** 391 * Returns the current line prefix. 392 */ 393 const std::string &curPrefix() { return *curPrefixPtr; } 394 395 /** 396 * Push a label onto the label stack, and prepend the given 397 * prefix string onto the current prefix. Labels will only be 398 * printed if an object within the label's scope is printed. 399 */ 400 void pushLabel(const std::string &lbl, 401 const std::string &prefix = " "); 402 403 /** 404 * Pop a label off the label stack. 405 */ 406 void popLabel(); 407 408 /** 409 * Print all of the pending unprinted labels on the 410 * stack. Called by printObj(), so normally not called by 411 * users unless bypassing printObj(). 412 */ 413 void printLabels(); 414 415 /** 416 * Print a Printable object to os, because it matched the 417 * address on a PrintReq. 418 */ 419 void printObj(Printable *obj); 420 }; 421 422 /** 423 * This packet's sender state. Devices should use dynamic_cast<> 424 * to cast to the state appropriate to the sender. The intent of 425 * this variable is to allow a device to attach extra information 426 * to a request. A response packet must return the sender state 427 * that was attached to the original request (even if a new packet 428 * is created). 429 */ 430 SenderState *senderState; 431 432 /** 433 * Push a new sender state to the packet and make the current 434 * sender state the predecessor of the new one. This should be 435 * prefered over direct manipulation of the senderState member 436 * variable. 437 * 438 * @param sender_state SenderState to push at the top of the stack 439 */ 440 void pushSenderState(SenderState *sender_state); 441 442 /** 443 * Pop the top of the state stack and return a pointer to it. This 444 * assumes the current sender state is not NULL. This should be 445 * preferred over direct manipulation of the senderState member 446 * variable. 447 * 448 * @return The current top of the stack 449 */ 450 SenderState *popSenderState(); 451 452 /** 453 * Go through the sender state stack and return the first instance 454 * that is of type T (as determined by a dynamic_cast). If there 455 * is no sender state of type T, NULL is returned. 456 * 457 * @return The topmost state of type T 458 */ 459 template <typename T> 460 T * findNextSenderState() const 461 { 462 T *t = NULL; 463 SenderState* sender_state = senderState; 464 while (t == NULL && sender_state != NULL) { 465 t = dynamic_cast<T*>(sender_state); 466 sender_state = sender_state->predecessor; 467 } 468 return t; 469 } 470 471 /// Return the string name of the cmd field (for debugging and 472 /// tracing). 473 const std::string &cmdString() const { return cmd.toString(); } 474 475 /// Return the index of this command. 476 inline int cmdToIndex() const { return cmd.toInt(); } 477 478 bool isRead() const { return cmd.isRead(); } 479 bool isWrite() const { return cmd.isWrite(); } 480 bool isUpgrade() const { return cmd.isUpgrade(); } 481 bool isRequest() const { return cmd.isRequest(); } 482 bool isResponse() const { return cmd.isResponse(); } 483 bool needsExclusive() const { return cmd.needsExclusive(); } 484 bool needsResponse() const { return cmd.needsResponse(); } 485 bool isInvalidate() const { return cmd.isInvalidate(); } 486 bool hasData() const { return cmd.hasData(); } 487 bool isLLSC() const { return cmd.isLLSC(); } 488 bool isError() const { return cmd.isError(); } 489 bool isPrint() const { return cmd.isPrint(); } 490 bool isFlush() const { return cmd.isFlush(); } 491 492 // Snoop flags 493 void assertMemInhibit() 494 { 495 assert(isRequest()); 496 assert(!flags.isSet(MEM_INHIBIT)); 497 flags.set(MEM_INHIBIT); 498 } 499 bool memInhibitAsserted() const { return flags.isSet(MEM_INHIBIT); } 500 void assertShared() { flags.set(SHARED); } 501 bool sharedAsserted() const { return flags.isSet(SHARED); } 502 503 // Special control flags 504 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 505 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 506 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); } 507 bool isSupplyExclusive() const { return flags.isSet(SUPPLY_EXCLUSIVE); } 508 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 509 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 510 void setBlockCached() { flags.set(BLOCK_CACHED); } 511 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 512 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 513 514 // Network error conditions... encapsulate them as methods since 515 // their encoding keeps changing (from result field to command 516 // field, etc.) 517 void 518 setBadAddress() 519 { 520 assert(isResponse()); 521 cmd = MemCmd::BadAddressError; 522 } 523 524 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; } 537 538 Addr getOffset(unsigned int blk_size) const 539 { 540 return getAddr() & Addr(blk_size - 1); 541 } 542 543 Addr getBlockAddr(unsigned int blk_size) const 544 { 545 return getAddr() & ~(Addr(blk_size - 1)); 546 } 547 548 bool isSecure() const 549 { 550 assert(flags.isSet(VALID_ADDR)); 551 return _isSecure; 552 } 553 554 /** 555 * It has been determined that the SC packet should successfully update 556 * memory. Therefore, convert this SC packet to a normal write. 557 */ 558 void 559 convertScToWrite() 560 { 561 assert(isLLSC()); 562 assert(isWrite()); 563 cmd = MemCmd::WriteReq; 564 } 565 566 /** 567 * When ruby is in use, Ruby will monitor the cache line and the 568 * phys memory should treat LL ops as normal reads. 569 */ 570 void 571 convertLlToRead() 572 { 573 assert(isLLSC()); 574 assert(isRead()); 575 cmd = MemCmd::ReadReq; 576 } 577 578 /** 579 * Constructor. Note that a Request object must be constructed 580 * first, but the Requests's physical address and size fields need 581 * not be valid. The command must be supplied. 582 */ 583 Packet(const RequestPtr _req, MemCmd _cmd) 584 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 585 size(0), headerDelay(0), payloadDelay(0), 586 senderState(NULL) 587 { 588 if (req->hasPaddr()) { 589 addr = req->getPaddr(); 590 flags.set(VALID_ADDR); 591 _isSecure = req->isSecure(); 592 } 593 if (req->hasSize()) { 594 size = req->getSize(); 595 flags.set(VALID_SIZE); 596 } 597 } 598 599 /** 600 * Alternate constructor if you are trying to create a packet with 601 * a request that is for a whole block, not the address from the 602 * req. this allows for overriding the size/addr of the req. 603 */ 604 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize) 605 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 606 headerDelay(0), payloadDelay(0), 607 senderState(NULL) 608 { 609 if (req->hasPaddr()) { 610 addr = req->getPaddr() & ~(_blkSize - 1); 611 flags.set(VALID_ADDR); 612 _isSecure = req->isSecure(); 613 } 614 size = _blkSize; 615 flags.set(VALID_SIZE); 616 } 617 618 /** 619 * Alternate constructor for copying a packet. Copy all fields 620 * *except* if the original packet's data was dynamic, don't copy 621 * that, as we can't guarantee that the new packet's lifetime is 622 * less than that of the original packet. In this case the new 623 * packet should allocate its own data. 624 */ 625 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 626 : cmd(pkt->cmd), req(pkt->req), 627 data(nullptr), 628 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 629 bytesValid(pkt->bytesValid), 630 headerDelay(pkt->headerDelay), 631 payloadDelay(pkt->payloadDelay), 632 senderState(pkt->senderState) 633 { 634 if (!clear_flags) 635 flags.set(pkt->flags & COPY_FLAGS); 636 637 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 638 639 // should we allocate space for data, or not, the express 640 // snoops do not need to carry any data as they only serve to 641 // co-ordinate state changes 642 if (alloc_data) { 643 // even if asked to allocate data, if the original packet 644 // holds static data, then the sender will not be doing 645 // any memcpy on receiving the response, thus we simply 646 // carry the pointer forward 647 if (pkt->flags.isSet(STATIC_DATA)) { 648 data = pkt->data; 649 flags.set(STATIC_DATA); 650 } else { 651 allocate(); 652 } 653 } 654 } 655 656 /** 657 * Generate the appropriate read MemCmd based on the Request flags. 658 */ 659 static MemCmd 660 makeReadCmd(const RequestPtr req) 661 { 662 if (req->isLLSC()) 663 return MemCmd::LoadLockedReq; 664 else if (req->isPrefetch()) 665 return MemCmd::SoftPFReq; 666 else 667 return MemCmd::ReadReq; 668 } 669 670 /** 671 * Generate the appropriate write MemCmd based on the Request flags. 672 */ 673 static MemCmd 674 makeWriteCmd(const RequestPtr req) 675 { 676 if (req->isLLSC()) 677 return MemCmd::StoreCondReq; 678 else if (req->isSwap()) 679 return MemCmd::SwapReq; 680 else 681 return MemCmd::WriteReq; 682 } 683 684 /** 685 * Constructor-like methods that return Packets based on Request objects. 686 * Fine-tune the MemCmd type if it's not a vanilla read or write. 687 */ 688 static PacketPtr 689 createRead(const RequestPtr req) 690 { 691 return new Packet(req, makeReadCmd(req)); 692 } 693 694 static PacketPtr 695 createWrite(const RequestPtr req) 696 { 697 return new Packet(req, makeWriteCmd(req)); 698 } 699 700 /** 701 * clean up packet variables 702 */ 703 ~Packet() 704 { 705 // Delete the request object if this is a request packet which 706 // does not need a response, because the requester will not get 707 // a chance. If the request packet needs a response then the 708 // request will be deleted on receipt of the response 709 // packet. We also make sure to never delete the request for 710 // express snoops, even for cases when responses are not 711 // needed (CleanEvict and Writeback), since the snoop packet 712 // re-uses the same request. 713 if (req && isRequest() && !needsResponse() && 714 !isExpressSnoop()) { 715 delete req; 716 } 717 deleteData(); 718 } 719 720 /** 721 * Take a request packet and modify it in place to be suitable for 722 * returning as a response to that request. 723 */ 724 void 725 makeResponse() 726 { 727 assert(needsResponse()); 728 assert(isRequest()); 729 cmd = cmd.responseCommand(); 730 731 // responses are never express, even if the snoop that 732 // triggered them was 733 flags.clear(EXPRESS_SNOOP); 734 } 735 736 void 737 makeAtomicResponse() 738 { 739 makeResponse(); 740 } 741 742 void 743 makeTimingResponse() 744 { 745 makeResponse(); 746 } 747 748 void 749 setFunctionalResponseStatus(bool success) 750 { 751 if (!success) { 752 if (isWrite()) { 753 cmd = MemCmd::FunctionalWriteError; 754 } else { 755 cmd = MemCmd::FunctionalReadError; 756 } 757 } 758 } 759 760 void 761 setSize(unsigned size) 762 { 763 assert(!flags.isSet(VALID_SIZE)); 764 765 this->size = size; 766 flags.set(VALID_SIZE); 767 } 768 769 770 public: 771 /** 772 * @{ 773 * @name Data accessor mehtods 774 */ 775 776 /** 777 * Set the data pointer to the following value that should not be 778 * freed. Static data allows us to do a single memcpy even if 779 * multiple packets are required to get from source to destination 780 * and back. In essence the pointer is set calling dataStatic on 781 * the original packet, and whenever this packet is copied and 782 * forwarded the same pointer is passed on. When a packet 783 * eventually reaches the destination holding the data, it is 784 * copied once into the location originally set. On the way back 785 * to the source, no copies are necessary. 786 */ 787 template <typename T> 788 void 789 dataStatic(T *p) 790 { 791 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 792 data = (PacketDataPtr)p; 793 flags.set(STATIC_DATA); 794 } 795 796 /** 797 * Set the data pointer to the following value that should not be 798 * freed. This version of the function allows the pointer passed 799 * to us to be const. To avoid issues down the line we cast the 800 * constness away, the alternative would be to keep both a const 801 * and non-const data pointer and cleverly choose between 802 * them. Note that this is only allowed for static data. 803 */ 804 template <typename T> 805 void 806 dataStaticConst(const T *p) 807 { 808 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 809 data = const_cast<PacketDataPtr>(p); 810 flags.set(STATIC_DATA); 811 } 812 813 /** 814 * Set the data pointer to a value that should have delete [] 815 * called on it. Dynamic data is local to this packet, and as the 816 * packet travels from source to destination, forwarded packets 817 * will allocate their own data. When a packet reaches the final 818 * destination it will populate the dynamic data of that specific 819 * packet, and on the way back towards the source, memcpy will be 820 * invoked in every step where a new packet was created e.g. in 821 * the caches. Ultimately when the response reaches the source a 822 * final memcpy is needed to extract the data from the packet 823 * before it is deallocated. 824 */ 825 template <typename T> 826 void 827 dataDynamic(T *p) 828 { 829 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 830 data = (PacketDataPtr)p; 831 flags.set(DYNAMIC_DATA); 832 } 833 834 /** 835 * get a pointer to the data ptr. 836 */ 837 template <typename T> 838 T* 839 getPtr() 840 { 841 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 842 return (T*)data; 843 } 844 845 template <typename T> 846 const T* 847 getConstPtr() const 848 { 849 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 850 return (const T*)data; 851 } 852 853 /** 854 * Get the data in the packet byte swapped from big endian to 855 * host endian. 856 */ 857 template <typename T> 858 T getBE() const; 859 860 /** 861 * Get the data in the packet byte swapped from little endian to 862 * host endian. 863 */ 864 template <typename T> 865 T getLE() const; 866 867 /** 868 * Get the data in the packet byte swapped from the specified 869 * endianness. 870 */ 871 template <typename T> 872 T get(ByteOrder endian) const; 873 874 /** 875 * Get the data in the packet byte swapped from guest to host 876 * endian. 877 */ 878 template <typename T> 879 T get() const; 880 881 /** Set the value in the data pointer to v as big endian. */ 882 template <typename T> 883 void setBE(T v); 884 885 /** Set the value in the data pointer to v as little endian. */ 886 template <typename T> 887 void setLE(T v); 888 889 /** 890 * Set the value in the data pointer to v using the specified 891 * endianness. 892 */ 893 template <typename T> 894 void set(T v, ByteOrder endian); 895 896 /** Set the value in the data pointer to v as guest endian. */ 897 template <typename T> 898 void set(T v); 899 900 /** 901 * Copy data into the packet from the provided pointer. 902 */ 903 void 904 setData(const uint8_t *p) 905 { 906 // we should never be copying data onto itself, which means we 907 // must idenfity packets with static data, as they carry the 908 // same pointer from source to destination and back 909 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 910 911 if (p != getPtr<uint8_t>()) 912 // for packet with allocated dynamic data, we copy data from 913 // one to the other, e.g. a forwarded response to a response 914 std::memcpy(getPtr<uint8_t>(), p, getSize()); 915 } 916 917 /** 918 * Copy data into the packet from the provided block pointer, 919 * which is aligned to the given block size. 920 */ 921 void 922 setDataFromBlock(const uint8_t *blk_data, int blkSize) 923 { 924 setData(blk_data + getOffset(blkSize)); 925 } 926 927 /** 928 * Copy data from the packet to the provided block pointer, which 929 * is aligned to the given block size. 930 */ 931 void 932 writeData(uint8_t *p) const 933 { 934 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 935 } 936 937 /** 938 * Copy data from the packet to the memory at the provided pointer. 939 */ 940 void 941 writeDataToBlock(uint8_t *blk_data, int blkSize) const 942 { 943 writeData(blk_data + getOffset(blkSize)); 944 } 945 946 /** 947 * delete the data pointed to in the data pointer. Ok to call to 948 * matter how data was allocted. 949 */ 950 void 951 deleteData() 952 { 953 if (flags.isSet(DYNAMIC_DATA)) 954 delete [] data; 955 956 flags.clear(STATIC_DATA|DYNAMIC_DATA); 957 data = NULL; 958 } 959 960 /** Allocate memory for the packet. */ 961 void 962 allocate() 963 { 964 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 965 flags.set(DYNAMIC_DATA); 966 data = new uint8_t[getSize()]; 967 } 968 969 /** @} */ 970 971 private: // Private data accessor methods 972 /** Get the data in the packet without byte swapping. */ 973 template <typename T> 974 T getRaw() const; 975 976 /** Set the value in the data pointer to v without byte swapping. */ 977 template <typename T> 978 void setRaw(T v); 979 980 public: 981 /** 982 * Check a functional request against a memory value stored in 983 * another packet (i.e. an in-transit request or 984 * response). Returns true if the current packet is a read, and 985 * the other packet provides the data, which is then copied to the 986 * current packet. If the current packet is a write, and the other 987 * packet intersects this one, then we update the data 988 * accordingly. 989 */ 990 bool 991 checkFunctional(PacketPtr other) 992 { 993 // all packets that are carrying a payload should have a valid 994 // data pointer 995 return checkFunctional(other, other->getAddr(), other->isSecure(), 996 other->getSize(), 997 other->hasData() ? 998 other->getPtr<uint8_t>() : NULL); 999 } 1000 1001 /** 1002 * Is this request notification of a clean or dirty eviction from the cache. 1003 **/ 1004 bool 1005 evictingBlock() const 1006 { 1007 return (cmd == MemCmd::Writeback || 1008 cmd == MemCmd::CleanEvict); 1009 } 1010 1011 /** 1012 * Does the request need to check for cached copies of the same block 1013 * in the memory hierarchy above. 1014 **/ 1015 bool 1016 mustCheckAbove() const 1017 { 1018 return (cmd == MemCmd::HardPFReq || 1019 evictingBlock()); 1020 } 1021 1022 /** 1023 * Check a functional request against a memory value represented 1024 * by a base/size pair and an associated data array. If the 1025 * current packet is a read, it may be satisfied by the memory 1026 * value. If the current packet is a write, it may update the 1027 * memory value. 1028 */ 1029 bool 1030 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 1031 uint8_t *_data); 1032 1033 /** 1034 * Push label for PrintReq (safe to call unconditionally). 1035 */ 1036 void 1037 pushLabel(const std::string &lbl) 1038 { 1039 if (isPrint()) 1040 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 1041 } 1042 1043 /** 1044 * Pop label for PrintReq (safe to call unconditionally). 1045 */ 1046 void 1047 popLabel() 1048 { 1049 if (isPrint()) 1050 safe_cast<PrintReqState*>(senderState)->popLabel(); 1051 } 1052 1053 void print(std::ostream &o, int verbosity = 0, 1054 const std::string &prefix = "") const; 1055 1056 /** 1057 * A no-args wrapper of print(std::ostream...) 1058 * meant to be invoked from DPRINTFs 1059 * avoiding string overheads in fast mode 1060 * @return string with the request's type and start<->end addresses 1061 */ 1062 std::string print() const; 1063}; 1064 1065#endif //__MEM_PACKET_HH 1066