packet.hh revision 10940:49d9b53b21dc
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: 239 240 enum : FlagsType { 241 // Flags to transfer across when copying a packet 242 COPY_FLAGS = 0x0000000F, 243 244 SHARED = 0x00000001, 245 // Special control flags 246 /// Special timing-mode atomic snoop for multi-level coherence. 247 EXPRESS_SNOOP = 0x00000002, 248 /// Does supplier have exclusive copy? 249 /// Useful for multi-level coherence. 250 SUPPLY_EXCLUSIVE = 0x00000004, 251 // Snoop response flags 252 MEM_INHIBIT = 0x00000008, 253 254 /// Are the 'addr' and 'size' fields valid? 255 VALID_ADDR = 0x00000100, 256 VALID_SIZE = 0x00000200, 257 258 /// Is the data pointer set to a value that shouldn't be freed 259 /// when the packet is destroyed? 260 STATIC_DATA = 0x00001000, 261 /// The data pointer points to a value that should be freed when 262 /// the packet is destroyed. The pointer is assumed to be pointing 263 /// to an array, and delete [] is consequently called 264 DYNAMIC_DATA = 0x00002000, 265 266 /// suppress the error if this packet encounters a functional 267 /// access failure. 268 SUPPRESS_FUNC_ERROR = 0x00008000, 269 270 // Signal block present to squash prefetch and cache evict packets 271 // through express snoop flag 272 BLOCK_CACHED = 0x00010000 273 }; 274 275 Flags flags; 276 277 public: 278 typedef MemCmd::Command Command; 279 280 /// The command field of the packet. 281 MemCmd cmd; 282 283 /// A pointer to the original request. 284 const RequestPtr req; 285 286 private: 287 /** 288 * A pointer to the data being transfered. It can be differnt 289 * sizes at each level of the heirarchy so it belongs in the 290 * packet, not request. This may or may not be populated when a 291 * responder recieves the packet. If not populated it memory should 292 * be allocated. 293 */ 294 PacketDataPtr data; 295 296 /// The address of the request. This address could be virtual or 297 /// physical, depending on the system configuration. 298 Addr addr; 299 300 /// True if the request targets the secure memory space. 301 bool _isSecure; 302 303 /// The size of the request or transfer. 304 unsigned size; 305 306 /** 307 * Track the bytes found that satisfy a functional read. 308 */ 309 std::vector<bool> bytesValid; 310 311 public: 312 313 /** 314 * The extra delay from seeing the packet until the header is 315 * transmitted. This delay is used to communicate the crossbar 316 * forwarding latency to the neighbouring object (e.g. a cache) 317 * that actually makes the packet wait. As the delay is relative, 318 * a 32-bit unsigned should be sufficient. 319 */ 320 uint32_t headerDelay; 321 322 /** 323 * The extra pipelining delay from seeing the packet until the end of 324 * payload is transmitted by the component that provided it (if 325 * any). This includes the header delay. Similar to the header 326 * delay, this is used to make up for the fact that the 327 * crossbar does not make the packet wait. As the delay is 328 * relative, a 32-bit unsigned should be sufficient. 329 */ 330 uint32_t payloadDelay; 331 332 /** 333 * A virtual base opaque structure used to hold state associated 334 * with the packet (e.g., an MSHR), specific to a MemObject that 335 * sees the packet. A pointer to this state is returned in the 336 * packet's response so that the MemObject in question can quickly 337 * look up the state needed to process it. A specific subclass 338 * would be derived from this to carry state specific to a 339 * particular sending device. 340 * 341 * As multiple MemObjects may add their SenderState throughout the 342 * memory system, the SenderStates create a stack, where a 343 * MemObject can add a new Senderstate, as long as the 344 * predecessing SenderState is restored when the response comes 345 * back. For this reason, the predecessor should always be 346 * populated with the current SenderState of a packet before 347 * modifying the senderState field in the request packet. 348 */ 349 struct SenderState 350 { 351 SenderState* predecessor; 352 SenderState() : predecessor(NULL) {} 353 virtual ~SenderState() {} 354 }; 355 356 /** 357 * Object used to maintain state of a PrintReq. The senderState 358 * field of a PrintReq should always be of this type. 359 */ 360 class PrintReqState : public SenderState 361 { 362 private: 363 /** 364 * An entry in the label stack. 365 */ 366 struct LabelStackEntry 367 { 368 const std::string label; 369 std::string *prefix; 370 bool labelPrinted; 371 LabelStackEntry(const std::string &_label, std::string *_prefix); 372 }; 373 374 typedef std::list<LabelStackEntry> LabelStack; 375 LabelStack labelStack; 376 377 std::string *curPrefixPtr; 378 379 public: 380 std::ostream &os; 381 const int verbosity; 382 383 PrintReqState(std::ostream &os, int verbosity = 0); 384 ~PrintReqState(); 385 386 /** 387 * Returns the current line prefix. 388 */ 389 const std::string &curPrefix() { return *curPrefixPtr; } 390 391 /** 392 * Push a label onto the label stack, and prepend the given 393 * prefix string onto the current prefix. Labels will only be 394 * printed if an object within the label's scope is printed. 395 */ 396 void pushLabel(const std::string &lbl, 397 const std::string &prefix = " "); 398 399 /** 400 * Pop a label off the label stack. 401 */ 402 void popLabel(); 403 404 /** 405 * Print all of the pending unprinted labels on the 406 * stack. Called by printObj(), so normally not called by 407 * users unless bypassing printObj(). 408 */ 409 void printLabels(); 410 411 /** 412 * Print a Printable object to os, because it matched the 413 * address on a PrintReq. 414 */ 415 void printObj(Printable *obj); 416 }; 417 418 /** 419 * This packet's sender state. Devices should use dynamic_cast<> 420 * to cast to the state appropriate to the sender. The intent of 421 * this variable is to allow a device to attach extra information 422 * to a request. A response packet must return the sender state 423 * that was attached to the original request (even if a new packet 424 * is created). 425 */ 426 SenderState *senderState; 427 428 /** 429 * Push a new sender state to the packet and make the current 430 * sender state the predecessor of the new one. This should be 431 * prefered over direct manipulation of the senderState member 432 * variable. 433 * 434 * @param sender_state SenderState to push at the top of the stack 435 */ 436 void pushSenderState(SenderState *sender_state); 437 438 /** 439 * Pop the top of the state stack and return a pointer to it. This 440 * assumes the current sender state is not NULL. This should be 441 * preferred over direct manipulation of the senderState member 442 * variable. 443 * 444 * @return The current top of the stack 445 */ 446 SenderState *popSenderState(); 447 448 /** 449 * Go through the sender state stack and return the first instance 450 * that is of type T (as determined by a dynamic_cast). If there 451 * is no sender state of type T, NULL is returned. 452 * 453 * @return The topmost state of type T 454 */ 455 template <typename T> 456 T * findNextSenderState() const 457 { 458 T *t = NULL; 459 SenderState* sender_state = senderState; 460 while (t == NULL && sender_state != NULL) { 461 t = dynamic_cast<T*>(sender_state); 462 sender_state = sender_state->predecessor; 463 } 464 return t; 465 } 466 467 /// Return the string name of the cmd field (for debugging and 468 /// tracing). 469 const std::string &cmdString() const { return cmd.toString(); } 470 471 /// Return the index of this command. 472 inline int cmdToIndex() const { return cmd.toInt(); } 473 474 bool isRead() const { return cmd.isRead(); } 475 bool isWrite() const { return cmd.isWrite(); } 476 bool isUpgrade() const { return cmd.isUpgrade(); } 477 bool isRequest() const { return cmd.isRequest(); } 478 bool isResponse() const { return cmd.isResponse(); } 479 bool needsExclusive() const { return cmd.needsExclusive(); } 480 bool needsResponse() const { return cmd.needsResponse(); } 481 bool isInvalidate() const { return cmd.isInvalidate(); } 482 bool hasData() const { return cmd.hasData(); } 483 bool isLLSC() const { return cmd.isLLSC(); } 484 bool isError() const { return cmd.isError(); } 485 bool isPrint() const { return cmd.isPrint(); } 486 bool isFlush() const { return cmd.isFlush(); } 487 488 // Snoop flags 489 void assertMemInhibit() 490 { 491 assert(isRequest()); 492 assert(!flags.isSet(MEM_INHIBIT)); 493 flags.set(MEM_INHIBIT); 494 } 495 bool memInhibitAsserted() const { return flags.isSet(MEM_INHIBIT); } 496 void assertShared() { flags.set(SHARED); } 497 bool sharedAsserted() const { return flags.isSet(SHARED); } 498 499 // Special control flags 500 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 501 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 502 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); } 503 bool isSupplyExclusive() const { return flags.isSet(SUPPLY_EXCLUSIVE); } 504 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 505 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 506 void setBlockCached() { flags.set(BLOCK_CACHED); } 507 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 508 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 509 510 // Network error conditions... encapsulate them as methods since 511 // their encoding keeps changing (from result field to command 512 // field, etc.) 513 void 514 setBadAddress() 515 { 516 assert(isResponse()); 517 cmd = MemCmd::BadAddressError; 518 } 519 520 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 521 522 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 523 /** 524 * Update the address of this packet mid-transaction. This is used 525 * by the address mapper to change an already set address to a new 526 * one based on the system configuration. It is intended to remap 527 * an existing address, so it asserts that the current address is 528 * valid. 529 */ 530 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 531 532 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 533 534 Addr getOffset(unsigned int blk_size) const 535 { 536 return getAddr() & Addr(blk_size - 1); 537 } 538 539 Addr getBlockAddr(unsigned int blk_size) const 540 { 541 return getAddr() & ~(Addr(blk_size - 1)); 542 } 543 544 bool isSecure() const 545 { 546 assert(flags.isSet(VALID_ADDR)); 547 return _isSecure; 548 } 549 550 /** 551 * It has been determined that the SC packet should successfully update 552 * memory. Therefore, convert this SC packet to a normal write. 553 */ 554 void 555 convertScToWrite() 556 { 557 assert(isLLSC()); 558 assert(isWrite()); 559 cmd = MemCmd::WriteReq; 560 } 561 562 /** 563 * When ruby is in use, Ruby will monitor the cache line and the 564 * phys memory should treat LL ops as normal reads. 565 */ 566 void 567 convertLlToRead() 568 { 569 assert(isLLSC()); 570 assert(isRead()); 571 cmd = MemCmd::ReadReq; 572 } 573 574 /** 575 * Constructor. Note that a Request object must be constructed 576 * first, but the Requests's physical address and size fields need 577 * not be valid. The command must be supplied. 578 */ 579 Packet(const RequestPtr _req, MemCmd _cmd) 580 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 581 size(0), headerDelay(0), payloadDelay(0), 582 senderState(NULL) 583 { 584 if (req->hasPaddr()) { 585 addr = req->getPaddr(); 586 flags.set(VALID_ADDR); 587 _isSecure = req->isSecure(); 588 } 589 if (req->hasSize()) { 590 size = req->getSize(); 591 flags.set(VALID_SIZE); 592 } 593 } 594 595 /** 596 * Alternate constructor if you are trying to create a packet with 597 * a request that is for a whole block, not the address from the 598 * req. this allows for overriding the size/addr of the req. 599 */ 600 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize) 601 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 602 headerDelay(0), payloadDelay(0), 603 senderState(NULL) 604 { 605 if (req->hasPaddr()) { 606 addr = req->getPaddr() & ~(_blkSize - 1); 607 flags.set(VALID_ADDR); 608 _isSecure = req->isSecure(); 609 } 610 size = _blkSize; 611 flags.set(VALID_SIZE); 612 } 613 614 /** 615 * Alternate constructor for copying a packet. Copy all fields 616 * *except* if the original packet's data was dynamic, don't copy 617 * that, as we can't guarantee that the new packet's lifetime is 618 * less than that of the original packet. In this case the new 619 * packet should allocate its own data. 620 */ 621 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 622 : cmd(pkt->cmd), req(pkt->req), 623 data(nullptr), 624 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 625 bytesValid(pkt->bytesValid), 626 headerDelay(pkt->headerDelay), 627 payloadDelay(pkt->payloadDelay), 628 senderState(pkt->senderState) 629 { 630 if (!clear_flags) 631 flags.set(pkt->flags & COPY_FLAGS); 632 633 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 634 635 // should we allocate space for data, or not, the express 636 // snoops do not need to carry any data as they only serve to 637 // co-ordinate state changes 638 if (alloc_data) { 639 // even if asked to allocate data, if the original packet 640 // holds static data, then the sender will not be doing 641 // any memcpy on receiving the response, thus we simply 642 // carry the pointer forward 643 if (pkt->flags.isSet(STATIC_DATA)) { 644 data = pkt->data; 645 flags.set(STATIC_DATA); 646 } else { 647 allocate(); 648 } 649 } 650 } 651 652 /** 653 * Generate the appropriate read MemCmd based on the Request flags. 654 */ 655 static MemCmd 656 makeReadCmd(const RequestPtr req) 657 { 658 if (req->isLLSC()) 659 return MemCmd::LoadLockedReq; 660 else if (req->isPrefetch()) 661 return MemCmd::SoftPFReq; 662 else 663 return MemCmd::ReadReq; 664 } 665 666 /** 667 * Generate the appropriate write MemCmd based on the Request flags. 668 */ 669 static MemCmd 670 makeWriteCmd(const RequestPtr req) 671 { 672 if (req->isLLSC()) 673 return MemCmd::StoreCondReq; 674 else if (req->isSwap()) 675 return MemCmd::SwapReq; 676 else 677 return MemCmd::WriteReq; 678 } 679 680 /** 681 * Constructor-like methods that return Packets based on Request objects. 682 * Fine-tune the MemCmd type if it's not a vanilla read or write. 683 */ 684 static PacketPtr 685 createRead(const RequestPtr req) 686 { 687 return new Packet(req, makeReadCmd(req)); 688 } 689 690 static PacketPtr 691 createWrite(const RequestPtr req) 692 { 693 return new Packet(req, makeWriteCmd(req)); 694 } 695 696 /** 697 * clean up packet variables 698 */ 699 ~Packet() 700 { 701 // Delete the request object if this is a request packet which 702 // does not need a response, because the requester will not get 703 // a chance. If the request packet needs a response then the 704 // request will be deleted on receipt of the response 705 // packet. We also make sure to never delete the request for 706 // express snoops, even for cases when responses are not 707 // needed (CleanEvict and Writeback), since the snoop packet 708 // re-uses the same request. 709 if (req && isRequest() && !needsResponse() && 710 !isExpressSnoop()) { 711 delete req; 712 } 713 deleteData(); 714 } 715 716 /** 717 * Take a request packet and modify it in place to be suitable for 718 * returning as a response to that request. 719 */ 720 void 721 makeResponse() 722 { 723 assert(needsResponse()); 724 assert(isRequest()); 725 cmd = cmd.responseCommand(); 726 727 // responses are never express, even if the snoop that 728 // triggered them was 729 flags.clear(EXPRESS_SNOOP); 730 } 731 732 void 733 makeAtomicResponse() 734 { 735 makeResponse(); 736 } 737 738 void 739 makeTimingResponse() 740 { 741 makeResponse(); 742 } 743 744 void 745 setFunctionalResponseStatus(bool success) 746 { 747 if (!success) { 748 if (isWrite()) { 749 cmd = MemCmd::FunctionalWriteError; 750 } else { 751 cmd = MemCmd::FunctionalReadError; 752 } 753 } 754 } 755 756 void 757 setSize(unsigned size) 758 { 759 assert(!flags.isSet(VALID_SIZE)); 760 761 this->size = size; 762 flags.set(VALID_SIZE); 763 } 764 765 766 /** 767 * Set the data pointer to the following value that should not be 768 * freed. Static data allows us to do a single memcpy even if 769 * multiple packets are required to get from source to destination 770 * and back. In essence the pointer is set calling dataStatic on 771 * the original packet, and whenever this packet is copied and 772 * forwarded the same pointer is passed on. When a packet 773 * eventually reaches the destination holding the data, it is 774 * copied once into the location originally set. On the way back 775 * to the source, no copies are necessary. 776 */ 777 template <typename T> 778 void 779 dataStatic(T *p) 780 { 781 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 782 data = (PacketDataPtr)p; 783 flags.set(STATIC_DATA); 784 } 785 786 /** 787 * Set the data pointer to the following value that should not be 788 * freed. This version of the function allows the pointer passed 789 * to us to be const. To avoid issues down the line we cast the 790 * constness away, the alternative would be to keep both a const 791 * and non-const data pointer and cleverly choose between 792 * them. Note that this is only allowed for static data. 793 */ 794 template <typename T> 795 void 796 dataStaticConst(const T *p) 797 { 798 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 799 data = const_cast<PacketDataPtr>(p); 800 flags.set(STATIC_DATA); 801 } 802 803 /** 804 * Set the data pointer to a value that should have delete [] 805 * called on it. Dynamic data is local to this packet, and as the 806 * packet travels from source to destination, forwarded packets 807 * will allocate their own data. When a packet reaches the final 808 * destination it will populate the dynamic data of that specific 809 * packet, and on the way back towards the source, memcpy will be 810 * invoked in every step where a new packet was created e.g. in 811 * the caches. Ultimately when the response reaches the source a 812 * final memcpy is needed to extract the data from the packet 813 * before it is deallocated. 814 */ 815 template <typename T> 816 void 817 dataDynamic(T *p) 818 { 819 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 820 data = (PacketDataPtr)p; 821 flags.set(DYNAMIC_DATA); 822 } 823 824 /** 825 * get a pointer to the data ptr. 826 */ 827 template <typename T> 828 T* 829 getPtr() 830 { 831 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 832 return (T*)data; 833 } 834 835 template <typename T> 836 const T* 837 getConstPtr() const 838 { 839 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 840 return (const T*)data; 841 } 842 843 /** 844 * return the value of what is pointed to in the packet. 845 */ 846 template <typename T> 847 T get() const; 848 849 /** 850 * set the value in the data pointer to v. 851 */ 852 template <typename T> 853 void set(T v); 854 855 /** 856 * Copy data into the packet from the provided pointer. 857 */ 858 void 859 setData(const uint8_t *p) 860 { 861 // we should never be copying data onto itself, which means we 862 // must idenfity packets with static data, as they carry the 863 // same pointer from source to destination and back 864 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 865 866 if (p != getPtr<uint8_t>()) 867 // for packet with allocated dynamic data, we copy data from 868 // one to the other, e.g. a forwarded response to a response 869 std::memcpy(getPtr<uint8_t>(), p, getSize()); 870 } 871 872 /** 873 * Copy data into the packet from the provided block pointer, 874 * which is aligned to the given block size. 875 */ 876 void 877 setDataFromBlock(const uint8_t *blk_data, int blkSize) 878 { 879 setData(blk_data + getOffset(blkSize)); 880 } 881 882 /** 883 * Copy data from the packet to the provided block pointer, which 884 * is aligned to the given block size. 885 */ 886 void 887 writeData(uint8_t *p) const 888 { 889 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 890 } 891 892 /** 893 * Copy data from the packet to the memory at the provided pointer. 894 */ 895 void 896 writeDataToBlock(uint8_t *blk_data, int blkSize) const 897 { 898 writeData(blk_data + getOffset(blkSize)); 899 } 900 901 /** 902 * delete the data pointed to in the data pointer. Ok to call to 903 * matter how data was allocted. 904 */ 905 void 906 deleteData() 907 { 908 if (flags.isSet(DYNAMIC_DATA)) 909 delete [] data; 910 911 flags.clear(STATIC_DATA|DYNAMIC_DATA); 912 data = NULL; 913 } 914 915 /** Allocate memory for the packet. */ 916 void 917 allocate() 918 { 919 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 920 flags.set(DYNAMIC_DATA); 921 data = new uint8_t[getSize()]; 922 } 923 924 /** 925 * Check a functional request against a memory value stored in 926 * another packet (i.e. an in-transit request or 927 * response). Returns true if the current packet is a read, and 928 * the other packet provides the data, which is then copied to the 929 * current packet. If the current packet is a write, and the other 930 * packet intersects this one, then we update the data 931 * accordingly. 932 */ 933 bool 934 checkFunctional(PacketPtr other) 935 { 936 // all packets that are carrying a payload should have a valid 937 // data pointer 938 return checkFunctional(other, other->getAddr(), other->isSecure(), 939 other->getSize(), 940 other->hasData() ? 941 other->getPtr<uint8_t>() : NULL); 942 } 943 944 /** 945 * Is this request notification of a clean or dirty eviction from the cache. 946 **/ 947 bool 948 evictingBlock() const 949 { 950 return (cmd == MemCmd::Writeback || 951 cmd == MemCmd::CleanEvict); 952 } 953 954 /** 955 * Does the request need to check for cached copies of the same block 956 * in the memory hierarchy above. 957 **/ 958 bool 959 mustCheckAbove() const 960 { 961 return (cmd == MemCmd::HardPFReq || 962 evictingBlock()); 963 } 964 965 /** 966 * Check a functional request against a memory value represented 967 * by a base/size pair and an associated data array. If the 968 * current packet is a read, it may be satisfied by the memory 969 * value. If the current packet is a write, it may update the 970 * memory value. 971 */ 972 bool 973 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 974 uint8_t *_data); 975 976 /** 977 * Push label for PrintReq (safe to call unconditionally). 978 */ 979 void 980 pushLabel(const std::string &lbl) 981 { 982 if (isPrint()) 983 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 984 } 985 986 /** 987 * Pop label for PrintReq (safe to call unconditionally). 988 */ 989 void 990 popLabel() 991 { 992 if (isPrint()) 993 safe_cast<PrintReqState*>(senderState)->popLabel(); 994 } 995 996 void print(std::ostream &o, int verbosity = 0, 997 const std::string &prefix = "") const; 998 999 /** 1000 * A no-args wrapper of print(std::ostream...) 1001 * meant to be invoked from DPRINTFs 1002 * avoiding string overheads in fast mode 1003 * @return string with the request's type and start<->end addresses 1004 */ 1005 std::string print() const; 1006}; 1007 1008#endif //__MEM_PACKET_HH 1009