packet.hh revision 11256
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 WritebackDirty, 90 WritebackClean, 91 CleanEvict, 92 SoftPFReq, 93 HardPFReq, 94 SoftPFResp, 95 HardPFResp, 96 WriteLineReq, 97 UpgradeReq, 98 SCUpgradeReq, // Special "weak" upgrade for StoreCond 99 UpgradeResp, 100 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent) 101 UpgradeFailResp, // Valid for SCUpgradeReq only 102 ReadExReq, 103 ReadExResp, 104 ReadCleanReq, 105 ReadSharedReq, 106 LoadLockedReq, 107 StoreCondReq, 108 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent) 109 StoreCondResp, 110 SwapReq, 111 SwapResp, 112 MessageReq, 113 MessageResp, 114 MemFenceReq, 115 MemFenceResp, 116 // Error responses 117 // @TODO these should be classified as responses rather than 118 // requests; coding them as requests initially for backwards 119 // compatibility 120 InvalidDestError, // packet dest field invalid 121 BadAddressError, // memory address invalid 122 FunctionalReadError, // unable to fulfill functional read 123 FunctionalWriteError, // unable to fulfill functional write 124 // Fake simulator-only commands 125 PrintReq, // Print state matching address 126 FlushReq, //request for a cache flush 127 InvalidateReq, // request for address to be invalidated 128 InvalidateResp, 129 NUM_MEM_CMDS 130 }; 131 132 private: 133 /** 134 * List of command attributes. 135 */ 136 enum Attribute 137 { 138 IsRead, //!< Data flows from responder to requester 139 IsWrite, //!< Data flows from requester to responder 140 IsUpgrade, 141 IsInvalidate, 142 NeedsExclusive, //!< Requires exclusive copy to complete in-cache 143 IsRequest, //!< Issued by requester 144 IsResponse, //!< Issue by responder 145 NeedsResponse, //!< Requester needs response from target 146 IsEviction, 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 bool isEviction() const { return testCmdAttrib(IsEviction); } 196 197 /** 198 * A writeback is an eviction that carries data. 199 */ 200 bool isWriteback() const { return testCmdAttrib(IsEviction) && 201 testCmdAttrib(HasData); } 202 203 /** 204 * Check if this particular packet type carries payload data. Note 205 * that this does not reflect if the data pointer of the packet is 206 * valid or not. 207 */ 208 bool hasData() const { return testCmdAttrib(HasData); } 209 bool isLLSC() const { return testCmdAttrib(IsLlsc); } 210 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); } 211 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); } 212 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) || 213 testCmdAttrib(IsHWPrefetch); } 214 bool isError() const { return testCmdAttrib(IsError); } 215 bool isPrint() const { return testCmdAttrib(IsPrint); } 216 bool isFlush() const { return testCmdAttrib(IsFlush); } 217 218 const Command 219 responseCommand() const 220 { 221 return commandInfo[cmd].response; 222 } 223 224 /// Return the string to a cmd given by idx. 225 const std::string &toString() const { return commandInfo[cmd].str; } 226 int toInt() const { return (int)cmd; } 227 228 MemCmd(Command _cmd) : cmd(_cmd) { } 229 MemCmd(int _cmd) : cmd((Command)_cmd) { } 230 MemCmd() : cmd(InvalidCmd) { } 231 232 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); } 233 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); } 234}; 235 236/** 237 * A Packet is used to encapsulate a transfer between two objects in 238 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 239 * single Request travels all the way from the requester to the 240 * ultimate destination and back, possibly being conveyed by several 241 * different Packets along the way.) 242 */ 243class Packet : public Printable 244{ 245 public: 246 typedef uint32_t FlagsType; 247 typedef ::Flags<FlagsType> Flags; 248 249 private: 250 251 enum : FlagsType { 252 // Flags to transfer across when copying a packet 253 COPY_FLAGS = 0x0000000F, 254 255 SHARED = 0x00000001, 256 // Special control flags 257 /// Special timing-mode atomic snoop for multi-level coherence. 258 EXPRESS_SNOOP = 0x00000002, 259 /// Does supplier have exclusive copy? 260 /// Useful for multi-level coherence. 261 SUPPLY_EXCLUSIVE = 0x00000004, 262 // Snoop response flags 263 MEM_INHIBIT = 0x00000008, 264 265 /// Are the 'addr' and 'size' fields valid? 266 VALID_ADDR = 0x00000100, 267 VALID_SIZE = 0x00000200, 268 269 /// Is the data pointer set to a value that shouldn't be freed 270 /// when the packet is destroyed? 271 STATIC_DATA = 0x00001000, 272 /// The data pointer points to a value that should be freed when 273 /// the packet is destroyed. The pointer is assumed to be pointing 274 /// to an array, and delete [] is consequently called 275 DYNAMIC_DATA = 0x00002000, 276 277 /// suppress the error if this packet encounters a functional 278 /// access failure. 279 SUPPRESS_FUNC_ERROR = 0x00008000, 280 281 // Signal block present to squash prefetch and cache evict packets 282 // through express snoop flag 283 BLOCK_CACHED = 0x00010000 284 }; 285 286 Flags flags; 287 288 public: 289 typedef MemCmd::Command Command; 290 291 /// The command field of the packet. 292 MemCmd cmd; 293 294 /// A pointer to the original request. 295 const RequestPtr req; 296 297 private: 298 /** 299 * A pointer to the data being transfered. It can be differnt 300 * sizes at each level of the heirarchy so it belongs in the 301 * packet, not request. This may or may not be populated when a 302 * responder recieves the packet. If not populated it memory should 303 * be allocated. 304 */ 305 PacketDataPtr data; 306 307 /// The address of the request. This address could be virtual or 308 /// physical, depending on the system configuration. 309 Addr addr; 310 311 /// True if the request targets the secure memory space. 312 bool _isSecure; 313 314 /// The size of the request or transfer. 315 unsigned size; 316 317 /** 318 * Track the bytes found that satisfy a functional read. 319 */ 320 std::vector<bool> bytesValid; 321 322 public: 323 324 /** 325 * The extra delay from seeing the packet until the header is 326 * transmitted. This delay is used to communicate the crossbar 327 * forwarding latency to the neighbouring object (e.g. a cache) 328 * that actually makes the packet wait. As the delay is relative, 329 * a 32-bit unsigned should be sufficient. 330 */ 331 uint32_t headerDelay; 332 333 /** 334 * Keep track of the extra delay incurred by snooping upwards 335 * before sending a request down the memory system. This is used 336 * by the coherent crossbar to account for the additional request 337 * delay. 338 */ 339 uint32_t snoopDelay; 340 341 /** 342 * The extra pipelining delay from seeing the packet until the end of 343 * payload is transmitted by the component that provided it (if 344 * any). This includes the header delay. Similar to the header 345 * delay, this is used to make up for the fact that the 346 * crossbar does not make the packet wait. As the delay is 347 * relative, a 32-bit unsigned should be sufficient. 348 */ 349 uint32_t payloadDelay; 350 351 /** 352 * A virtual base opaque structure used to hold state associated 353 * with the packet (e.g., an MSHR), specific to a MemObject that 354 * sees the packet. A pointer to this state is returned in the 355 * packet's response so that the MemObject in question can quickly 356 * look up the state needed to process it. A specific subclass 357 * would be derived from this to carry state specific to a 358 * particular sending device. 359 * 360 * As multiple MemObjects may add their SenderState throughout the 361 * memory system, the SenderStates create a stack, where a 362 * MemObject can add a new Senderstate, as long as the 363 * predecessing SenderState is restored when the response comes 364 * back. For this reason, the predecessor should always be 365 * populated with the current SenderState of a packet before 366 * modifying the senderState field in the request packet. 367 */ 368 struct SenderState 369 { 370 SenderState* predecessor; 371 SenderState() : predecessor(NULL) {} 372 virtual ~SenderState() {} 373 }; 374 375 /** 376 * Object used to maintain state of a PrintReq. The senderState 377 * field of a PrintReq should always be of this type. 378 */ 379 class PrintReqState : public SenderState 380 { 381 private: 382 /** 383 * An entry in the label stack. 384 */ 385 struct LabelStackEntry 386 { 387 const std::string label; 388 std::string *prefix; 389 bool labelPrinted; 390 LabelStackEntry(const std::string &_label, std::string *_prefix); 391 }; 392 393 typedef std::list<LabelStackEntry> LabelStack; 394 LabelStack labelStack; 395 396 std::string *curPrefixPtr; 397 398 public: 399 std::ostream &os; 400 const int verbosity; 401 402 PrintReqState(std::ostream &os, int verbosity = 0); 403 ~PrintReqState(); 404 405 /** 406 * Returns the current line prefix. 407 */ 408 const std::string &curPrefix() { return *curPrefixPtr; } 409 410 /** 411 * Push a label onto the label stack, and prepend the given 412 * prefix string onto the current prefix. Labels will only be 413 * printed if an object within the label's scope is printed. 414 */ 415 void pushLabel(const std::string &lbl, 416 const std::string &prefix = " "); 417 418 /** 419 * Pop a label off the label stack. 420 */ 421 void popLabel(); 422 423 /** 424 * Print all of the pending unprinted labels on the 425 * stack. Called by printObj(), so normally not called by 426 * users unless bypassing printObj(). 427 */ 428 void printLabels(); 429 430 /** 431 * Print a Printable object to os, because it matched the 432 * address on a PrintReq. 433 */ 434 void printObj(Printable *obj); 435 }; 436 437 /** 438 * This packet's sender state. Devices should use dynamic_cast<> 439 * to cast to the state appropriate to the sender. The intent of 440 * this variable is to allow a device to attach extra information 441 * to a request. A response packet must return the sender state 442 * that was attached to the original request (even if a new packet 443 * is created). 444 */ 445 SenderState *senderState; 446 447 /** 448 * Push a new sender state to the packet and make the current 449 * sender state the predecessor of the new one. This should be 450 * prefered over direct manipulation of the senderState member 451 * variable. 452 * 453 * @param sender_state SenderState to push at the top of the stack 454 */ 455 void pushSenderState(SenderState *sender_state); 456 457 /** 458 * Pop the top of the state stack and return a pointer to it. This 459 * assumes the current sender state is not NULL. This should be 460 * preferred over direct manipulation of the senderState member 461 * variable. 462 * 463 * @return The current top of the stack 464 */ 465 SenderState *popSenderState(); 466 467 /** 468 * Go through the sender state stack and return the first instance 469 * that is of type T (as determined by a dynamic_cast). If there 470 * is no sender state of type T, NULL is returned. 471 * 472 * @return The topmost state of type T 473 */ 474 template <typename T> 475 T * findNextSenderState() const 476 { 477 T *t = NULL; 478 SenderState* sender_state = senderState; 479 while (t == NULL && sender_state != NULL) { 480 t = dynamic_cast<T*>(sender_state); 481 sender_state = sender_state->predecessor; 482 } 483 return t; 484 } 485 486 /// Return the string name of the cmd field (for debugging and 487 /// tracing). 488 const std::string &cmdString() const { return cmd.toString(); } 489 490 /// Return the index of this command. 491 inline int cmdToIndex() const { return cmd.toInt(); } 492 493 bool isRead() const { return cmd.isRead(); } 494 bool isWrite() const { return cmd.isWrite(); } 495 bool isUpgrade() const { return cmd.isUpgrade(); } 496 bool isRequest() const { return cmd.isRequest(); } 497 bool isResponse() const { return cmd.isResponse(); } 498 bool needsExclusive() const { return cmd.needsExclusive(); } 499 bool needsResponse() const { return cmd.needsResponse(); } 500 bool isInvalidate() const { return cmd.isInvalidate(); } 501 bool isEviction() const { return cmd.isEviction(); } 502 bool isWriteback() const { return cmd.isWriteback(); } 503 bool hasData() const { return cmd.hasData(); } 504 bool isLLSC() const { return cmd.isLLSC(); } 505 bool isError() const { return cmd.isError(); } 506 bool isPrint() const { return cmd.isPrint(); } 507 bool isFlush() const { return cmd.isFlush(); } 508 509 // Snoop flags 510 void assertMemInhibit() 511 { 512 assert(isRequest()); 513 assert(!flags.isSet(MEM_INHIBIT)); 514 flags.set(MEM_INHIBIT); 515 } 516 bool memInhibitAsserted() const { return flags.isSet(MEM_INHIBIT); } 517 void assertShared() { flags.set(SHARED); } 518 bool sharedAsserted() const { return flags.isSet(SHARED); } 519 520 // Special control flags 521 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 522 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 523 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); } 524 bool isSupplyExclusive() const { return flags.isSet(SUPPLY_EXCLUSIVE); } 525 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 526 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 527 void setBlockCached() { flags.set(BLOCK_CACHED); } 528 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 529 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 530 531 // Network error conditions... encapsulate them as methods since 532 // their encoding keeps changing (from result field to command 533 // field, etc.) 534 void 535 setBadAddress() 536 { 537 assert(isResponse()); 538 cmd = MemCmd::BadAddressError; 539 } 540 541 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 542 543 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 544 /** 545 * Update the address of this packet mid-transaction. This is used 546 * by the address mapper to change an already set address to a new 547 * one based on the system configuration. It is intended to remap 548 * an existing address, so it asserts that the current address is 549 * valid. 550 */ 551 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 552 553 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 554 555 Addr getOffset(unsigned int blk_size) const 556 { 557 return getAddr() & Addr(blk_size - 1); 558 } 559 560 Addr getBlockAddr(unsigned int blk_size) const 561 { 562 return getAddr() & ~(Addr(blk_size - 1)); 563 } 564 565 bool isSecure() const 566 { 567 assert(flags.isSet(VALID_ADDR)); 568 return _isSecure; 569 } 570 571 /** 572 * It has been determined that the SC packet should successfully update 573 * memory. Therefore, convert this SC packet to a normal write. 574 */ 575 void 576 convertScToWrite() 577 { 578 assert(isLLSC()); 579 assert(isWrite()); 580 cmd = MemCmd::WriteReq; 581 } 582 583 /** 584 * When ruby is in use, Ruby will monitor the cache line and the 585 * phys memory should treat LL ops as normal reads. 586 */ 587 void 588 convertLlToRead() 589 { 590 assert(isLLSC()); 591 assert(isRead()); 592 cmd = MemCmd::ReadReq; 593 } 594 595 /** 596 * Constructor. Note that a Request object must be constructed 597 * first, but the Requests's physical address and size fields need 598 * not be valid. The command must be supplied. 599 */ 600 Packet(const RequestPtr _req, MemCmd _cmd) 601 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 602 size(0), headerDelay(0), snoopDelay(0), payloadDelay(0), 603 senderState(NULL) 604 { 605 if (req->hasPaddr()) { 606 addr = req->getPaddr(); 607 flags.set(VALID_ADDR); 608 _isSecure = req->isSecure(); 609 } 610 if (req->hasSize()) { 611 size = req->getSize(); 612 flags.set(VALID_SIZE); 613 } 614 } 615 616 /** 617 * Alternate constructor if you are trying to create a packet with 618 * a request that is for a whole block, not the address from the 619 * req. this allows for overriding the size/addr of the req. 620 */ 621 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize) 622 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 623 headerDelay(0), snoopDelay(0), payloadDelay(0), 624 senderState(NULL) 625 { 626 if (req->hasPaddr()) { 627 addr = req->getPaddr() & ~(_blkSize - 1); 628 flags.set(VALID_ADDR); 629 _isSecure = req->isSecure(); 630 } 631 size = _blkSize; 632 flags.set(VALID_SIZE); 633 } 634 635 /** 636 * Alternate constructor for copying a packet. Copy all fields 637 * *except* if the original packet's data was dynamic, don't copy 638 * that, as we can't guarantee that the new packet's lifetime is 639 * less than that of the original packet. In this case the new 640 * packet should allocate its own data. 641 */ 642 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 643 : cmd(pkt->cmd), req(pkt->req), 644 data(nullptr), 645 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 646 bytesValid(pkt->bytesValid), 647 headerDelay(pkt->headerDelay), 648 snoopDelay(0), 649 payloadDelay(pkt->payloadDelay), 650 senderState(pkt->senderState) 651 { 652 if (!clear_flags) 653 flags.set(pkt->flags & COPY_FLAGS); 654 655 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 656 657 // should we allocate space for data, or not, the express 658 // snoops do not need to carry any data as they only serve to 659 // co-ordinate state changes 660 if (alloc_data) { 661 // even if asked to allocate data, if the original packet 662 // holds static data, then the sender will not be doing 663 // any memcpy on receiving the response, thus we simply 664 // carry the pointer forward 665 if (pkt->flags.isSet(STATIC_DATA)) { 666 data = pkt->data; 667 flags.set(STATIC_DATA); 668 } else { 669 allocate(); 670 } 671 } 672 } 673 674 /** 675 * Generate the appropriate read MemCmd based on the Request flags. 676 */ 677 static MemCmd 678 makeReadCmd(const RequestPtr req) 679 { 680 if (req->isLLSC()) 681 return MemCmd::LoadLockedReq; 682 else if (req->isPrefetch()) 683 return MemCmd::SoftPFReq; 684 else 685 return MemCmd::ReadReq; 686 } 687 688 /** 689 * Generate the appropriate write MemCmd based on the Request flags. 690 */ 691 static MemCmd 692 makeWriteCmd(const RequestPtr req) 693 { 694 if (req->isLLSC()) 695 return MemCmd::StoreCondReq; 696 else if (req->isSwap()) 697 return MemCmd::SwapReq; 698 else 699 return MemCmd::WriteReq; 700 } 701 702 /** 703 * Constructor-like methods that return Packets based on Request objects. 704 * Fine-tune the MemCmd type if it's not a vanilla read or write. 705 */ 706 static PacketPtr 707 createRead(const RequestPtr req) 708 { 709 return new Packet(req, makeReadCmd(req)); 710 } 711 712 static PacketPtr 713 createWrite(const RequestPtr req) 714 { 715 return new Packet(req, makeWriteCmd(req)); 716 } 717 718 /** 719 * clean up packet variables 720 */ 721 ~Packet() 722 { 723 // Delete the request object if this is a request packet which 724 // does not need a response, because the requester will not get 725 // a chance. If the request packet needs a response then the 726 // request will be deleted on receipt of the response 727 // packet. We also make sure to never delete the request for 728 // express snoops, even for cases when responses are not 729 // needed (CleanEvict and Writeback), since the snoop packet 730 // re-uses the same request. 731 if (req && isRequest() && !needsResponse() && 732 !isExpressSnoop()) { 733 delete req; 734 } 735 deleteData(); 736 } 737 738 /** 739 * Take a request packet and modify it in place to be suitable for 740 * returning as a response to that request. 741 */ 742 void 743 makeResponse() 744 { 745 assert(needsResponse()); 746 assert(isRequest()); 747 cmd = cmd.responseCommand(); 748 749 // responses are never express, even if the snoop that 750 // triggered them was 751 flags.clear(EXPRESS_SNOOP); 752 } 753 754 void 755 makeAtomicResponse() 756 { 757 makeResponse(); 758 } 759 760 void 761 makeTimingResponse() 762 { 763 makeResponse(); 764 } 765 766 void 767 setFunctionalResponseStatus(bool success) 768 { 769 if (!success) { 770 if (isWrite()) { 771 cmd = MemCmd::FunctionalWriteError; 772 } else { 773 cmd = MemCmd::FunctionalReadError; 774 } 775 } 776 } 777 778 void 779 setSize(unsigned size) 780 { 781 assert(!flags.isSet(VALID_SIZE)); 782 783 this->size = size; 784 flags.set(VALID_SIZE); 785 } 786 787 788 public: 789 /** 790 * @{ 791 * @name Data accessor mehtods 792 */ 793 794 /** 795 * Set the data pointer to the following value that should not be 796 * freed. Static data allows us to do a single memcpy even if 797 * multiple packets are required to get from source to destination 798 * and back. In essence the pointer is set calling dataStatic on 799 * the original packet, and whenever this packet is copied and 800 * forwarded the same pointer is passed on. When a packet 801 * eventually reaches the destination holding the data, it is 802 * copied once into the location originally set. On the way back 803 * to the source, no copies are necessary. 804 */ 805 template <typename T> 806 void 807 dataStatic(T *p) 808 { 809 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 810 data = (PacketDataPtr)p; 811 flags.set(STATIC_DATA); 812 } 813 814 /** 815 * Set the data pointer to the following value that should not be 816 * freed. This version of the function allows the pointer passed 817 * to us to be const. To avoid issues down the line we cast the 818 * constness away, the alternative would be to keep both a const 819 * and non-const data pointer and cleverly choose between 820 * them. Note that this is only allowed for static data. 821 */ 822 template <typename T> 823 void 824 dataStaticConst(const T *p) 825 { 826 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 827 data = const_cast<PacketDataPtr>(p); 828 flags.set(STATIC_DATA); 829 } 830 831 /** 832 * Set the data pointer to a value that should have delete [] 833 * called on it. Dynamic data is local to this packet, and as the 834 * packet travels from source to destination, forwarded packets 835 * will allocate their own data. When a packet reaches the final 836 * destination it will populate the dynamic data of that specific 837 * packet, and on the way back towards the source, memcpy will be 838 * invoked in every step where a new packet was created e.g. in 839 * the caches. Ultimately when the response reaches the source a 840 * final memcpy is needed to extract the data from the packet 841 * before it is deallocated. 842 */ 843 template <typename T> 844 void 845 dataDynamic(T *p) 846 { 847 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 848 data = (PacketDataPtr)p; 849 flags.set(DYNAMIC_DATA); 850 } 851 852 /** 853 * get a pointer to the data ptr. 854 */ 855 template <typename T> 856 T* 857 getPtr() 858 { 859 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 860 return (T*)data; 861 } 862 863 template <typename T> 864 const T* 865 getConstPtr() const 866 { 867 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 868 return (const T*)data; 869 } 870 871 /** 872 * Get the data in the packet byte swapped from big endian to 873 * host endian. 874 */ 875 template <typename T> 876 T getBE() const; 877 878 /** 879 * Get the data in the packet byte swapped from little endian to 880 * host endian. 881 */ 882 template <typename T> 883 T getLE() const; 884 885 /** 886 * Get the data in the packet byte swapped from the specified 887 * endianness. 888 */ 889 template <typename T> 890 T get(ByteOrder endian) const; 891 892 /** 893 * Get the data in the packet byte swapped from guest to host 894 * endian. 895 */ 896 template <typename T> 897 T get() const; 898 899 /** Set the value in the data pointer to v as big endian. */ 900 template <typename T> 901 void setBE(T v); 902 903 /** Set the value in the data pointer to v as little endian. */ 904 template <typename T> 905 void setLE(T v); 906 907 /** 908 * Set the value in the data pointer to v using the specified 909 * endianness. 910 */ 911 template <typename T> 912 void set(T v, ByteOrder endian); 913 914 /** Set the value in the data pointer to v as guest endian. */ 915 template <typename T> 916 void set(T v); 917 918 /** 919 * Copy data into the packet from the provided pointer. 920 */ 921 void 922 setData(const uint8_t *p) 923 { 924 // we should never be copying data onto itself, which means we 925 // must idenfity packets with static data, as they carry the 926 // same pointer from source to destination and back 927 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 928 929 if (p != getPtr<uint8_t>()) 930 // for packet with allocated dynamic data, we copy data from 931 // one to the other, e.g. a forwarded response to a response 932 std::memcpy(getPtr<uint8_t>(), p, getSize()); 933 } 934 935 /** 936 * Copy data into the packet from the provided block pointer, 937 * which is aligned to the given block size. 938 */ 939 void 940 setDataFromBlock(const uint8_t *blk_data, int blkSize) 941 { 942 setData(blk_data + getOffset(blkSize)); 943 } 944 945 /** 946 * Copy data from the packet to the provided block pointer, which 947 * is aligned to the given block size. 948 */ 949 void 950 writeData(uint8_t *p) const 951 { 952 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 953 } 954 955 /** 956 * Copy data from the packet to the memory at the provided pointer. 957 */ 958 void 959 writeDataToBlock(uint8_t *blk_data, int blkSize) const 960 { 961 writeData(blk_data + getOffset(blkSize)); 962 } 963 964 /** 965 * delete the data pointed to in the data pointer. Ok to call to 966 * matter how data was allocted. 967 */ 968 void 969 deleteData() 970 { 971 if (flags.isSet(DYNAMIC_DATA)) 972 delete [] data; 973 974 flags.clear(STATIC_DATA|DYNAMIC_DATA); 975 data = NULL; 976 } 977 978 /** Allocate memory for the packet. */ 979 void 980 allocate() 981 { 982 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 983 flags.set(DYNAMIC_DATA); 984 data = new uint8_t[getSize()]; 985 } 986 987 /** @} */ 988 989 private: // Private data accessor methods 990 /** Get the data in the packet without byte swapping. */ 991 template <typename T> 992 T getRaw() const; 993 994 /** Set the value in the data pointer to v without byte swapping. */ 995 template <typename T> 996 void setRaw(T v); 997 998 public: 999 /** 1000 * Check a functional request against a memory value stored in 1001 * another packet (i.e. an in-transit request or 1002 * response). Returns true if the current packet is a read, and 1003 * the other packet provides the data, which is then copied to the 1004 * current packet. If the current packet is a write, and the other 1005 * packet intersects this one, then we update the data 1006 * accordingly. 1007 */ 1008 bool 1009 checkFunctional(PacketPtr other) 1010 { 1011 // all packets that are carrying a payload should have a valid 1012 // data pointer 1013 return checkFunctional(other, other->getAddr(), other->isSecure(), 1014 other->getSize(), 1015 other->hasData() ? 1016 other->getPtr<uint8_t>() : NULL); 1017 } 1018 1019 /** 1020 * Does the request need to check for cached copies of the same block 1021 * in the memory hierarchy above. 1022 **/ 1023 bool 1024 mustCheckAbove() const 1025 { 1026 return cmd == MemCmd::HardPFReq || isEviction(); 1027 } 1028 1029 /** 1030 * Is this packet a clean eviction, including both actual clean 1031 * evict packets, but also clean writebacks. 1032 */ 1033 bool 1034 isCleanEviction() const 1035 { 1036 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean; 1037 } 1038 1039 /** 1040 * Check a functional request against a memory value represented 1041 * by a base/size pair and an associated data array. If the 1042 * current packet is a read, it may be satisfied by the memory 1043 * value. If the current packet is a write, it may update the 1044 * memory value. 1045 */ 1046 bool 1047 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 1048 uint8_t *_data); 1049 1050 /** 1051 * Push label for PrintReq (safe to call unconditionally). 1052 */ 1053 void 1054 pushLabel(const std::string &lbl) 1055 { 1056 if (isPrint()) 1057 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 1058 } 1059 1060 /** 1061 * Pop label for PrintReq (safe to call unconditionally). 1062 */ 1063 void 1064 popLabel() 1065 { 1066 if (isPrint()) 1067 safe_cast<PrintReqState*>(senderState)->popLabel(); 1068 } 1069 1070 void print(std::ostream &o, int verbosity = 0, 1071 const std::string &prefix = "") const; 1072 1073 /** 1074 * A no-args wrapper of print(std::ostream...) 1075 * meant to be invoked from DPRINTFs 1076 * avoiding string overheads in fast mode 1077 * @return string with the request's type and start<->end addresses 1078 */ 1079 std::string print() const; 1080}; 1081 1082#endif //__MEM_PACKET_HH 1083