packet.hh revision 13348:e3d801b37735
1/* 2 * Copyright (c) 2012-2018 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 * Nikos Nikoleris 46 */ 47 48/** 49 * @file 50 * Declaration of the Packet class. 51 */ 52 53#ifndef __MEM_PACKET_HH__ 54#define __MEM_PACKET_HH__ 55 56#include <bitset> 57#include <cassert> 58#include <list> 59 60#include "base/cast.hh" 61#include "base/compiler.hh" 62#include "base/flags.hh" 63#include "base/logging.hh" 64#include "base/printable.hh" 65#include "base/types.hh" 66#include "config/the_isa.hh" 67#include "mem/request.hh" 68#include "sim/core.hh" 69 70class Packet; 71typedef Packet *PacketPtr; 72typedef uint8_t* PacketDataPtr; 73typedef std::list<PacketPtr> PacketList; 74typedef uint64_t PacketId; 75 76class MemCmd 77{ 78 friend class Packet; 79 80 public: 81 /** 82 * List of all commands associated with a packet. 83 */ 84 enum Command 85 { 86 InvalidCmd, 87 ReadReq, 88 ReadResp, 89 ReadRespWithInvalidate, 90 WriteReq, 91 WriteResp, 92 WritebackDirty, 93 WritebackClean, 94 WriteClean, // writes dirty data below without evicting 95 CleanEvict, 96 SoftPFReq, 97 HardPFReq, 98 SoftPFResp, 99 HardPFResp, 100 WriteLineReq, 101 UpgradeReq, 102 SCUpgradeReq, // Special "weak" upgrade for StoreCond 103 UpgradeResp, 104 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent) 105 UpgradeFailResp, // Valid for SCUpgradeReq only 106 ReadExReq, 107 ReadExResp, 108 ReadCleanReq, 109 ReadSharedReq, 110 LoadLockedReq, 111 StoreCondReq, 112 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent) 113 StoreCondResp, 114 SwapReq, 115 SwapResp, 116 MessageReq, 117 MessageResp, 118 MemFenceReq, 119 MemFenceResp, 120 CleanSharedReq, 121 CleanSharedResp, 122 CleanInvalidReq, 123 CleanInvalidResp, 124 // Error responses 125 // @TODO these should be classified as responses rather than 126 // requests; coding them as requests initially for backwards 127 // compatibility 128 InvalidDestError, // packet dest field invalid 129 BadAddressError, // memory address invalid 130 FunctionalReadError, // unable to fulfill functional read 131 FunctionalWriteError, // unable to fulfill functional write 132 // Fake simulator-only commands 133 PrintReq, // Print state matching address 134 FlushReq, //request for a cache flush 135 InvalidateReq, // request for address to be invalidated 136 InvalidateResp, 137 NUM_MEM_CMDS 138 }; 139 140 private: 141 /** 142 * List of command attributes. 143 */ 144 enum Attribute 145 { 146 IsRead, //!< Data flows from responder to requester 147 IsWrite, //!< Data flows from requester to responder 148 IsUpgrade, 149 IsInvalidate, 150 IsClean, //!< Cleans any existing dirty blocks 151 NeedsWritable, //!< Requires writable copy to complete in-cache 152 IsRequest, //!< Issued by requester 153 IsResponse, //!< Issue by responder 154 NeedsResponse, //!< Requester needs response from target 155 IsEviction, 156 IsSWPrefetch, 157 IsHWPrefetch, 158 IsLlsc, //!< Alpha/MIPS LL or SC access 159 HasData, //!< There is an associated payload 160 IsError, //!< Error response 161 IsPrint, //!< Print state matching address (for debugging) 162 IsFlush, //!< Flush the address from caches 163 FromCache, //!< Request originated from a caching agent 164 NUM_COMMAND_ATTRIBUTES 165 }; 166 167 /** 168 * Structure that defines attributes and other data associated 169 * with a Command. 170 */ 171 struct CommandInfo 172 { 173 /// Set of attribute flags. 174 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 175 /// Corresponding response for requests; InvalidCmd if no 176 /// response is applicable. 177 const Command response; 178 /// String representation (for printing) 179 const std::string str; 180 }; 181 182 /// Array to map Command enum to associated info. 183 static const CommandInfo commandInfo[]; 184 185 private: 186 187 Command cmd; 188 189 bool 190 testCmdAttrib(MemCmd::Attribute attrib) const 191 { 192 return commandInfo[cmd].attributes[attrib] != 0; 193 } 194 195 public: 196 197 bool isRead() const { return testCmdAttrib(IsRead); } 198 bool isWrite() const { return testCmdAttrib(IsWrite); } 199 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); } 200 bool isRequest() const { return testCmdAttrib(IsRequest); } 201 bool isResponse() const { return testCmdAttrib(IsResponse); } 202 bool needsWritable() const { return testCmdAttrib(NeedsWritable); } 203 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 204 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 205 bool isEviction() const { return testCmdAttrib(IsEviction); } 206 bool isClean() const { return testCmdAttrib(IsClean); } 207 bool fromCache() const { return testCmdAttrib(FromCache); } 208 209 /** 210 * A writeback is an eviction that carries data. 211 */ 212 bool isWriteback() const { return testCmdAttrib(IsEviction) && 213 testCmdAttrib(HasData); } 214 215 /** 216 * Check if this particular packet type carries payload data. Note 217 * that this does not reflect if the data pointer of the packet is 218 * valid or not. 219 */ 220 bool hasData() const { return testCmdAttrib(HasData); } 221 bool isLLSC() const { return testCmdAttrib(IsLlsc); } 222 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); } 223 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); } 224 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) || 225 testCmdAttrib(IsHWPrefetch); } 226 bool isError() const { return testCmdAttrib(IsError); } 227 bool isPrint() const { return testCmdAttrib(IsPrint); } 228 bool isFlush() const { return testCmdAttrib(IsFlush); } 229 230 Command 231 responseCommand() const 232 { 233 return commandInfo[cmd].response; 234 } 235 236 /// Return the string to a cmd given by idx. 237 const std::string &toString() const { return commandInfo[cmd].str; } 238 int toInt() const { return (int)cmd; } 239 240 MemCmd(Command _cmd) : cmd(_cmd) { } 241 MemCmd(int _cmd) : cmd((Command)_cmd) { } 242 MemCmd() : cmd(InvalidCmd) { } 243 244 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); } 245 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); } 246}; 247 248/** 249 * A Packet is used to encapsulate a transfer between two objects in 250 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 251 * single Request travels all the way from the requester to the 252 * ultimate destination and back, possibly being conveyed by several 253 * different Packets along the way.) 254 */ 255class Packet : public Printable 256{ 257 public: 258 typedef uint32_t FlagsType; 259 typedef ::Flags<FlagsType> Flags; 260 261 private: 262 263 enum : FlagsType { 264 // Flags to transfer across when copying a packet 265 COPY_FLAGS = 0x0000003F, 266 267 // Does this packet have sharers (which means it should not be 268 // considered writable) or not. See setHasSharers below. 269 HAS_SHARERS = 0x00000001, 270 271 // Special control flags 272 /// Special timing-mode atomic snoop for multi-level coherence. 273 EXPRESS_SNOOP = 0x00000002, 274 275 /// Allow a responding cache to inform the cache hierarchy 276 /// that it had a writable copy before responding. See 277 /// setResponderHadWritable below. 278 RESPONDER_HAD_WRITABLE = 0x00000004, 279 280 // Snoop co-ordination flag to indicate that a cache is 281 // responding to a snoop. See setCacheResponding below. 282 CACHE_RESPONDING = 0x00000008, 283 284 // The writeback/writeclean should be propagated further 285 // downstream by the receiver 286 WRITE_THROUGH = 0x00000010, 287 288 // Response co-ordination flag for cache maintenance 289 // operations 290 SATISFIED = 0x00000020, 291 292 /// Are the 'addr' and 'size' fields valid? 293 VALID_ADDR = 0x00000100, 294 VALID_SIZE = 0x00000200, 295 296 /// Is the data pointer set to a value that shouldn't be freed 297 /// when the packet is destroyed? 298 STATIC_DATA = 0x00001000, 299 /// The data pointer points to a value that should be freed when 300 /// the packet is destroyed. The pointer is assumed to be pointing 301 /// to an array, and delete [] is consequently called 302 DYNAMIC_DATA = 0x00002000, 303 304 /// suppress the error if this packet encounters a functional 305 /// access failure. 306 SUPPRESS_FUNC_ERROR = 0x00008000, 307 308 // Signal block present to squash prefetch and cache evict packets 309 // through express snoop flag 310 BLOCK_CACHED = 0x00010000 311 }; 312 313 Flags flags; 314 315 public: 316 typedef MemCmd::Command Command; 317 318 /// The command field of the packet. 319 MemCmd cmd; 320 321 const PacketId id; 322 323 /// A pointer to the original request. 324 RequestPtr req; 325 326 private: 327 /** 328 * A pointer to the data being transferred. It can be different 329 * sizes at each level of the hierarchy so it belongs to the 330 * packet, not request. This may or may not be populated when a 331 * responder receives the packet. If not populated memory should 332 * be allocated. 333 */ 334 PacketDataPtr data; 335 336 /// The address of the request. This address could be virtual or 337 /// physical, depending on the system configuration. 338 Addr addr; 339 340 /// True if the request targets the secure memory space. 341 bool _isSecure; 342 343 /// The size of the request or transfer. 344 unsigned size; 345 346 /** 347 * Track the bytes found that satisfy a functional read. 348 */ 349 std::vector<bool> bytesValid; 350 351 // Quality of Service priority value 352 uint8_t _qosValue; 353 354 public: 355 356 /** 357 * The extra delay from seeing the packet until the header is 358 * transmitted. This delay is used to communicate the crossbar 359 * forwarding latency to the neighbouring object (e.g. a cache) 360 * that actually makes the packet wait. As the delay is relative, 361 * a 32-bit unsigned should be sufficient. 362 */ 363 uint32_t headerDelay; 364 365 /** 366 * Keep track of the extra delay incurred by snooping upwards 367 * before sending a request down the memory system. This is used 368 * by the coherent crossbar to account for the additional request 369 * delay. 370 */ 371 uint32_t snoopDelay; 372 373 /** 374 * The extra pipelining delay from seeing the packet until the end of 375 * payload is transmitted by the component that provided it (if 376 * any). This includes the header delay. Similar to the header 377 * delay, this is used to make up for the fact that the 378 * crossbar does not make the packet wait. As the delay is 379 * relative, a 32-bit unsigned should be sufficient. 380 */ 381 uint32_t payloadDelay; 382 383 /** 384 * A virtual base opaque structure used to hold state associated 385 * with the packet (e.g., an MSHR), specific to a MemObject that 386 * sees the packet. A pointer to this state is returned in the 387 * packet's response so that the MemObject in question can quickly 388 * look up the state needed to process it. A specific subclass 389 * would be derived from this to carry state specific to a 390 * particular sending device. 391 * 392 * As multiple MemObjects may add their SenderState throughout the 393 * memory system, the SenderStates create a stack, where a 394 * MemObject can add a new Senderstate, as long as the 395 * predecessing SenderState is restored when the response comes 396 * back. For this reason, the predecessor should always be 397 * populated with the current SenderState of a packet before 398 * modifying the senderState field in the request packet. 399 */ 400 struct SenderState 401 { 402 SenderState* predecessor; 403 SenderState() : predecessor(NULL) {} 404 virtual ~SenderState() {} 405 }; 406 407 /** 408 * Object used to maintain state of a PrintReq. The senderState 409 * field of a PrintReq should always be of this type. 410 */ 411 class PrintReqState : public SenderState 412 { 413 private: 414 /** 415 * An entry in the label stack. 416 */ 417 struct LabelStackEntry 418 { 419 const std::string label; 420 std::string *prefix; 421 bool labelPrinted; 422 LabelStackEntry(const std::string &_label, std::string *_prefix); 423 }; 424 425 typedef std::list<LabelStackEntry> LabelStack; 426 LabelStack labelStack; 427 428 std::string *curPrefixPtr; 429 430 public: 431 std::ostream &os; 432 const int verbosity; 433 434 PrintReqState(std::ostream &os, int verbosity = 0); 435 ~PrintReqState(); 436 437 /** 438 * Returns the current line prefix. 439 */ 440 const std::string &curPrefix() { return *curPrefixPtr; } 441 442 /** 443 * Push a label onto the label stack, and prepend the given 444 * prefix string onto the current prefix. Labels will only be 445 * printed if an object within the label's scope is printed. 446 */ 447 void pushLabel(const std::string &lbl, 448 const std::string &prefix = " "); 449 450 /** 451 * Pop a label off the label stack. 452 */ 453 void popLabel(); 454 455 /** 456 * Print all of the pending unprinted labels on the 457 * stack. Called by printObj(), so normally not called by 458 * users unless bypassing printObj(). 459 */ 460 void printLabels(); 461 462 /** 463 * Print a Printable object to os, because it matched the 464 * address on a PrintReq. 465 */ 466 void printObj(Printable *obj); 467 }; 468 469 /** 470 * This packet's sender state. Devices should use dynamic_cast<> 471 * to cast to the state appropriate to the sender. The intent of 472 * this variable is to allow a device to attach extra information 473 * to a request. A response packet must return the sender state 474 * that was attached to the original request (even if a new packet 475 * is created). 476 */ 477 SenderState *senderState; 478 479 /** 480 * Push a new sender state to the packet and make the current 481 * sender state the predecessor of the new one. This should be 482 * prefered over direct manipulation of the senderState member 483 * variable. 484 * 485 * @param sender_state SenderState to push at the top of the stack 486 */ 487 void pushSenderState(SenderState *sender_state); 488 489 /** 490 * Pop the top of the state stack and return a pointer to it. This 491 * assumes the current sender state is not NULL. This should be 492 * preferred over direct manipulation of the senderState member 493 * variable. 494 * 495 * @return The current top of the stack 496 */ 497 SenderState *popSenderState(); 498 499 /** 500 * Go through the sender state stack and return the first instance 501 * that is of type T (as determined by a dynamic_cast). If there 502 * is no sender state of type T, NULL is returned. 503 * 504 * @return The topmost state of type T 505 */ 506 template <typename T> 507 T * findNextSenderState() const 508 { 509 T *t = NULL; 510 SenderState* sender_state = senderState; 511 while (t == NULL && sender_state != NULL) { 512 t = dynamic_cast<T*>(sender_state); 513 sender_state = sender_state->predecessor; 514 } 515 return t; 516 } 517 518 /// Return the string name of the cmd field (for debugging and 519 /// tracing). 520 const std::string &cmdString() const { return cmd.toString(); } 521 522 /// Return the index of this command. 523 inline int cmdToIndex() const { return cmd.toInt(); } 524 525 bool isRead() const { return cmd.isRead(); } 526 bool isWrite() const { return cmd.isWrite(); } 527 bool isUpgrade() const { return cmd.isUpgrade(); } 528 bool isRequest() const { return cmd.isRequest(); } 529 bool isResponse() const { return cmd.isResponse(); } 530 bool needsWritable() const 531 { 532 // we should never check if a response needsWritable, the 533 // request has this flag, and for a response we should rather 534 // look at the hasSharers flag (if not set, the response is to 535 // be considered writable) 536 assert(isRequest()); 537 return cmd.needsWritable(); 538 } 539 bool needsResponse() const { return cmd.needsResponse(); } 540 bool isInvalidate() const { return cmd.isInvalidate(); } 541 bool isEviction() const { return cmd.isEviction(); } 542 bool isClean() const { return cmd.isClean(); } 543 bool fromCache() const { return cmd.fromCache(); } 544 bool isWriteback() const { return cmd.isWriteback(); } 545 bool hasData() const { return cmd.hasData(); } 546 bool hasRespData() const 547 { 548 MemCmd resp_cmd = cmd.responseCommand(); 549 return resp_cmd.hasData(); 550 } 551 bool isLLSC() const { return cmd.isLLSC(); } 552 bool isError() const { return cmd.isError(); } 553 bool isPrint() const { return cmd.isPrint(); } 554 bool isFlush() const { return cmd.isFlush(); } 555 556 //@{ 557 /// Snoop flags 558 /** 559 * Set the cacheResponding flag. This is used by the caches to 560 * signal another cache that they are responding to a request. A 561 * cache will only respond to snoops if it has the line in either 562 * Modified or Owned state. Note that on snoop hits we always pass 563 * the line as Modified and never Owned. In the case of an Owned 564 * line we proceed to invalidate all other copies. 565 * 566 * On a cache fill (see Cache::handleFill), we check hasSharers 567 * first, ignoring the cacheResponding flag if hasSharers is set. 568 * A line is consequently allocated as: 569 * 570 * hasSharers cacheResponding state 571 * true false Shared 572 * true true Shared 573 * false false Exclusive 574 * false true Modified 575 */ 576 void setCacheResponding() 577 { 578 assert(isRequest()); 579 assert(!flags.isSet(CACHE_RESPONDING)); 580 flags.set(CACHE_RESPONDING); 581 } 582 bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); } 583 /** 584 * On fills, the hasSharers flag is used by the caches in 585 * combination with the cacheResponding flag, as clarified 586 * above. If the hasSharers flag is not set, the packet is passing 587 * writable. Thus, a response from a memory passes the line as 588 * writable by default. 589 * 590 * The hasSharers flag is also used by upstream caches to inform a 591 * downstream cache that they have the block (by calling 592 * setHasSharers on snoop request packets that hit in upstream 593 * cachs tags or MSHRs). If the snoop packet has sharers, a 594 * downstream cache is prevented from passing a dirty line upwards 595 * if it was not explicitly asked for a writable copy. See 596 * Cache::satisfyCpuSideRequest. 597 * 598 * The hasSharers flag is also used on writebacks, in 599 * combination with the WritbackClean or WritebackDirty commands, 600 * to allocate the block downstream either as: 601 * 602 * command hasSharers state 603 * WritebackDirty false Modified 604 * WritebackDirty true Owned 605 * WritebackClean false Exclusive 606 * WritebackClean true Shared 607 */ 608 void setHasSharers() { flags.set(HAS_SHARERS); } 609 bool hasSharers() const { return flags.isSet(HAS_SHARERS); } 610 //@} 611 612 /** 613 * The express snoop flag is used for two purposes. Firstly, it is 614 * used to bypass flow control for normal (non-snoop) requests 615 * going downstream in the memory system. In cases where a cache 616 * is responding to a snoop from another cache (it had a dirty 617 * line), but the line is not writable (and there are possibly 618 * other copies), the express snoop flag is set by the downstream 619 * cache to invalidate all other copies in zero time. Secondly, 620 * the express snoop flag is also set to be able to distinguish 621 * snoop packets that came from a downstream cache, rather than 622 * snoop packets from neighbouring caches. 623 */ 624 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 625 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 626 627 /** 628 * On responding to a snoop request (which only happens for 629 * Modified or Owned lines), make sure that we can transform an 630 * Owned response to a Modified one. If this flag is not set, the 631 * responding cache had the line in the Owned state, and there are 632 * possibly other Shared copies in the memory system. A downstream 633 * cache helps in orchestrating the invalidation of these copies 634 * by sending out the appropriate express snoops. 635 */ 636 void setResponderHadWritable() 637 { 638 assert(cacheResponding()); 639 assert(!responderHadWritable()); 640 flags.set(RESPONDER_HAD_WRITABLE); 641 } 642 bool responderHadWritable() const 643 { return flags.isSet(RESPONDER_HAD_WRITABLE); } 644 645 /** 646 * A writeback/writeclean cmd gets propagated further downstream 647 * by the receiver when the flag is set. 648 */ 649 void setWriteThrough() 650 { 651 assert(cmd.isWrite() && 652 (cmd.isEviction() || cmd == MemCmd::WriteClean)); 653 flags.set(WRITE_THROUGH); 654 } 655 void clearWriteThrough() { flags.clear(WRITE_THROUGH); } 656 bool writeThrough() const { return flags.isSet(WRITE_THROUGH); } 657 658 /** 659 * Set when a request hits in a cache and the cache is not going 660 * to respond. This is used by the crossbar to coordinate 661 * responses for cache maintenance operations. 662 */ 663 void setSatisfied() 664 { 665 assert(cmd.isClean()); 666 assert(!flags.isSet(SATISFIED)); 667 flags.set(SATISFIED); 668 } 669 bool satisfied() const { return flags.isSet(SATISFIED); } 670 671 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 672 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 673 void setBlockCached() { flags.set(BLOCK_CACHED); } 674 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 675 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 676 677 /** 678 * QoS Value getter 679 * Returns 0 if QoS value was never set (constructor default). 680 * 681 * @return QoS priority value of the packet 682 */ 683 inline uint8_t qosValue() const { return _qosValue; } 684 685 /** 686 * QoS Value setter 687 * Interface for setting QoS priority value of the packet. 688 * 689 * @param qos_value QoS priority value 690 */ 691 inline void qosValue(const uint8_t qos_value) 692 { _qosValue = qos_value; } 693 694 inline MasterID masterId() const { return req->masterId(); } 695 696 // Network error conditions... encapsulate them as methods since 697 // their encoding keeps changing (from result field to command 698 // field, etc.) 699 void 700 setBadAddress() 701 { 702 assert(isResponse()); 703 cmd = MemCmd::BadAddressError; 704 } 705 706 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 707 708 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 709 /** 710 * Update the address of this packet mid-transaction. This is used 711 * by the address mapper to change an already set address to a new 712 * one based on the system configuration. It is intended to remap 713 * an existing address, so it asserts that the current address is 714 * valid. 715 */ 716 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 717 718 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 719 720 Addr getOffset(unsigned int blk_size) const 721 { 722 return getAddr() & Addr(blk_size - 1); 723 } 724 725 Addr getBlockAddr(unsigned int blk_size) const 726 { 727 return getAddr() & ~(Addr(blk_size - 1)); 728 } 729 730 bool isSecure() const 731 { 732 assert(flags.isSet(VALID_ADDR)); 733 return _isSecure; 734 } 735 736 /** 737 * Accessor function to atomic op. 738 */ 739 AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); } 740 bool isAtomicOp() const { return req->isAtomic(); } 741 742 /** 743 * It has been determined that the SC packet should successfully update 744 * memory. Therefore, convert this SC packet to a normal write. 745 */ 746 void 747 convertScToWrite() 748 { 749 assert(isLLSC()); 750 assert(isWrite()); 751 cmd = MemCmd::WriteReq; 752 } 753 754 /** 755 * When ruby is in use, Ruby will monitor the cache line and the 756 * phys memory should treat LL ops as normal reads. 757 */ 758 void 759 convertLlToRead() 760 { 761 assert(isLLSC()); 762 assert(isRead()); 763 cmd = MemCmd::ReadReq; 764 } 765 766 /** 767 * Constructor. Note that a Request object must be constructed 768 * first, but the Requests's physical address and size fields need 769 * not be valid. The command must be supplied. 770 */ 771 Packet(const RequestPtr &_req, MemCmd _cmd) 772 : cmd(_cmd), id((PacketId)_req.get()), req(_req), 773 data(nullptr), addr(0), _isSecure(false), size(0), 774 _qosValue(0), headerDelay(0), snoopDelay(0), 775 payloadDelay(0), senderState(NULL) 776 { 777 if (req->hasPaddr()) { 778 addr = req->getPaddr(); 779 flags.set(VALID_ADDR); 780 _isSecure = req->isSecure(); 781 } 782 if (req->hasSize()) { 783 size = req->getSize(); 784 flags.set(VALID_SIZE); 785 } 786 } 787 788 /** 789 * Alternate constructor if you are trying to create a packet with 790 * a request that is for a whole block, not the address from the 791 * req. this allows for overriding the size/addr of the req. 792 */ 793 Packet(const RequestPtr &_req, MemCmd _cmd, int _blkSize, PacketId _id = 0) 794 : cmd(_cmd), id(_id ? _id : (PacketId)_req.get()), req(_req), 795 data(nullptr), addr(0), _isSecure(false), 796 _qosValue(0), headerDelay(0), 797 snoopDelay(0), payloadDelay(0), senderState(NULL) 798 { 799 if (req->hasPaddr()) { 800 addr = req->getPaddr() & ~(_blkSize - 1); 801 flags.set(VALID_ADDR); 802 _isSecure = req->isSecure(); 803 } 804 size = _blkSize; 805 flags.set(VALID_SIZE); 806 } 807 808 /** 809 * Alternate constructor for copying a packet. Copy all fields 810 * *except* if the original packet's data was dynamic, don't copy 811 * that, as we can't guarantee that the new packet's lifetime is 812 * less than that of the original packet. In this case the new 813 * packet should allocate its own data. 814 */ 815 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 816 : cmd(pkt->cmd), id(pkt->id), req(pkt->req), 817 data(nullptr), 818 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 819 bytesValid(pkt->bytesValid), 820 _qosValue(pkt->qosValue()), 821 headerDelay(pkt->headerDelay), 822 snoopDelay(0), 823 payloadDelay(pkt->payloadDelay), 824 senderState(pkt->senderState) 825 { 826 if (!clear_flags) 827 flags.set(pkt->flags & COPY_FLAGS); 828 829 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 830 831 // should we allocate space for data, or not, the express 832 // snoops do not need to carry any data as they only serve to 833 // co-ordinate state changes 834 if (alloc_data) { 835 // even if asked to allocate data, if the original packet 836 // holds static data, then the sender will not be doing 837 // any memcpy on receiving the response, thus we simply 838 // carry the pointer forward 839 if (pkt->flags.isSet(STATIC_DATA)) { 840 data = pkt->data; 841 flags.set(STATIC_DATA); 842 } else { 843 allocate(); 844 } 845 } 846 } 847 848 /** 849 * Generate the appropriate read MemCmd based on the Request flags. 850 */ 851 static MemCmd 852 makeReadCmd(const RequestPtr &req) 853 { 854 if (req->isLLSC()) 855 return MemCmd::LoadLockedReq; 856 else if (req->isPrefetch()) 857 return MemCmd::SoftPFReq; 858 else 859 return MemCmd::ReadReq; 860 } 861 862 /** 863 * Generate the appropriate write MemCmd based on the Request flags. 864 */ 865 static MemCmd 866 makeWriteCmd(const RequestPtr &req) 867 { 868 if (req->isLLSC()) 869 return MemCmd::StoreCondReq; 870 else if (req->isSwap() || req->isAtomic()) 871 return MemCmd::SwapReq; 872 else if (req->isCacheInvalidate()) { 873 return req->isCacheClean() ? MemCmd::CleanInvalidReq : 874 MemCmd::InvalidateReq; 875 } else if (req->isCacheClean()) { 876 return MemCmd::CleanSharedReq; 877 } else 878 return MemCmd::WriteReq; 879 } 880 881 /** 882 * Constructor-like methods that return Packets based on Request objects. 883 * Fine-tune the MemCmd type if it's not a vanilla read or write. 884 */ 885 static PacketPtr 886 createRead(const RequestPtr &req) 887 { 888 return new Packet(req, makeReadCmd(req)); 889 } 890 891 static PacketPtr 892 createWrite(const RequestPtr &req) 893 { 894 return new Packet(req, makeWriteCmd(req)); 895 } 896 897 /** 898 * clean up packet variables 899 */ 900 ~Packet() 901 { 902 deleteData(); 903 } 904 905 /** 906 * Take a request packet and modify it in place to be suitable for 907 * returning as a response to that request. 908 */ 909 void 910 makeResponse() 911 { 912 assert(needsResponse()); 913 assert(isRequest()); 914 cmd = cmd.responseCommand(); 915 916 // responses are never express, even if the snoop that 917 // triggered them was 918 flags.clear(EXPRESS_SNOOP); 919 } 920 921 void 922 makeAtomicResponse() 923 { 924 makeResponse(); 925 } 926 927 void 928 makeTimingResponse() 929 { 930 makeResponse(); 931 } 932 933 void 934 setFunctionalResponseStatus(bool success) 935 { 936 if (!success) { 937 if (isWrite()) { 938 cmd = MemCmd::FunctionalWriteError; 939 } else { 940 cmd = MemCmd::FunctionalReadError; 941 } 942 } 943 } 944 945 void 946 setSize(unsigned size) 947 { 948 assert(!flags.isSet(VALID_SIZE)); 949 950 this->size = size; 951 flags.set(VALID_SIZE); 952 } 953 954 955 public: 956 /** 957 * @{ 958 * @name Data accessor mehtods 959 */ 960 961 /** 962 * Set the data pointer to the following value that should not be 963 * freed. Static data allows us to do a single memcpy even if 964 * multiple packets are required to get from source to destination 965 * and back. In essence the pointer is set calling dataStatic on 966 * the original packet, and whenever this packet is copied and 967 * forwarded the same pointer is passed on. When a packet 968 * eventually reaches the destination holding the data, it is 969 * copied once into the location originally set. On the way back 970 * to the source, no copies are necessary. 971 */ 972 template <typename T> 973 void 974 dataStatic(T *p) 975 { 976 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 977 data = (PacketDataPtr)p; 978 flags.set(STATIC_DATA); 979 } 980 981 /** 982 * Set the data pointer to the following value that should not be 983 * freed. This version of the function allows the pointer passed 984 * to us to be const. To avoid issues down the line we cast the 985 * constness away, the alternative would be to keep both a const 986 * and non-const data pointer and cleverly choose between 987 * them. Note that this is only allowed for static data. 988 */ 989 template <typename T> 990 void 991 dataStaticConst(const T *p) 992 { 993 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 994 data = const_cast<PacketDataPtr>(p); 995 flags.set(STATIC_DATA); 996 } 997 998 /** 999 * Set the data pointer to a value that should have delete [] 1000 * called on it. Dynamic data is local to this packet, and as the 1001 * packet travels from source to destination, forwarded packets 1002 * will allocate their own data. When a packet reaches the final 1003 * destination it will populate the dynamic data of that specific 1004 * packet, and on the way back towards the source, memcpy will be 1005 * invoked in every step where a new packet was created e.g. in 1006 * the caches. Ultimately when the response reaches the source a 1007 * final memcpy is needed to extract the data from the packet 1008 * before it is deallocated. 1009 */ 1010 template <typename T> 1011 void 1012 dataDynamic(T *p) 1013 { 1014 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 1015 data = (PacketDataPtr)p; 1016 flags.set(DYNAMIC_DATA); 1017 } 1018 1019 /** 1020 * get a pointer to the data ptr. 1021 */ 1022 template <typename T> 1023 T* 1024 getPtr() 1025 { 1026 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 1027 return (T*)data; 1028 } 1029 1030 template <typename T> 1031 const T* 1032 getConstPtr() const 1033 { 1034 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 1035 return (const T*)data; 1036 } 1037 1038 /** 1039 * Get the data in the packet byte swapped from big endian to 1040 * host endian. 1041 */ 1042 template <typename T> 1043 T getBE() const; 1044 1045 /** 1046 * Get the data in the packet byte swapped from little endian to 1047 * host endian. 1048 */ 1049 template <typename T> 1050 T getLE() const; 1051 1052 /** 1053 * Get the data in the packet byte swapped from the specified 1054 * endianness. 1055 */ 1056 template <typename T> 1057 T get(ByteOrder endian) const; 1058 1059#if THE_ISA != NULL_ISA 1060 /** 1061 * Get the data in the packet byte swapped from guest to host 1062 * endian. 1063 */ 1064 template <typename T> 1065 T get() const 1066 M5_DEPRECATED_MSG("The memory system should be ISA independent."); 1067#endif 1068 1069 /** Set the value in the data pointer to v as big endian. */ 1070 template <typename T> 1071 void setBE(T v); 1072 1073 /** Set the value in the data pointer to v as little endian. */ 1074 template <typename T> 1075 void setLE(T v); 1076 1077 /** 1078 * Set the value in the data pointer to v using the specified 1079 * endianness. 1080 */ 1081 template <typename T> 1082 void set(T v, ByteOrder endian); 1083 1084#if THE_ISA != NULL_ISA 1085 /** Set the value in the data pointer to v as guest endian. */ 1086 template <typename T> 1087 void set(T v) 1088 M5_DEPRECATED_MSG("The memory system should be ISA independent."); 1089#endif 1090 1091 /** 1092 * Get the data in the packet byte swapped from the specified 1093 * endianness and zero-extended to 64 bits. 1094 */ 1095 uint64_t getUintX(ByteOrder endian) const; 1096 1097 /** 1098 * Set the value in the word w after truncating it to the length 1099 * of the packet and then byteswapping it to the desired 1100 * endianness. 1101 */ 1102 void setUintX(uint64_t w, ByteOrder endian); 1103 1104 /** 1105 * Copy data into the packet from the provided pointer. 1106 */ 1107 void 1108 setData(const uint8_t *p) 1109 { 1110 // we should never be copying data onto itself, which means we 1111 // must idenfity packets with static data, as they carry the 1112 // same pointer from source to destination and back 1113 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 1114 1115 if (p != getPtr<uint8_t>()) 1116 // for packet with allocated dynamic data, we copy data from 1117 // one to the other, e.g. a forwarded response to a response 1118 std::memcpy(getPtr<uint8_t>(), p, getSize()); 1119 } 1120 1121 /** 1122 * Copy data into the packet from the provided block pointer, 1123 * which is aligned to the given block size. 1124 */ 1125 void 1126 setDataFromBlock(const uint8_t *blk_data, int blkSize) 1127 { 1128 setData(blk_data + getOffset(blkSize)); 1129 } 1130 1131 /** 1132 * Copy data from the packet to the memory at the provided pointer. 1133 * @param p Pointer to which data will be copied. 1134 */ 1135 void 1136 writeData(uint8_t *p) const 1137 { 1138 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 1139 } 1140 1141 /** 1142 * Copy data from the packet to the provided block pointer, which 1143 * is aligned to the given block size. 1144 * @param blk_data Pointer to block to which data will be copied. 1145 * @param blkSize Block size in bytes. 1146 */ 1147 void 1148 writeDataToBlock(uint8_t *blk_data, int blkSize) const 1149 { 1150 writeData(blk_data + getOffset(blkSize)); 1151 } 1152 1153 /** 1154 * delete the data pointed to in the data pointer. Ok to call to 1155 * matter how data was allocted. 1156 */ 1157 void 1158 deleteData() 1159 { 1160 if (flags.isSet(DYNAMIC_DATA)) 1161 delete [] data; 1162 1163 flags.clear(STATIC_DATA|DYNAMIC_DATA); 1164 data = NULL; 1165 } 1166 1167 /** Allocate memory for the packet. */ 1168 void 1169 allocate() 1170 { 1171 // if either this command or the response command has a data 1172 // payload, actually allocate space 1173 if (hasData() || hasRespData()) { 1174 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 1175 flags.set(DYNAMIC_DATA); 1176 data = new uint8_t[getSize()]; 1177 } 1178 } 1179 1180 /** @} */ 1181 1182 /** Get the data in the packet without byte swapping. */ 1183 template <typename T> 1184 T getRaw() const; 1185 1186 /** Set the value in the data pointer to v without byte swapping. */ 1187 template <typename T> 1188 void setRaw(T v); 1189 1190 public: 1191 /** 1192 * Check a functional request against a memory value stored in 1193 * another packet (i.e. an in-transit request or 1194 * response). Returns true if the current packet is a read, and 1195 * the other packet provides the data, which is then copied to the 1196 * current packet. If the current packet is a write, and the other 1197 * packet intersects this one, then we update the data 1198 * accordingly. 1199 */ 1200 bool 1201 trySatisfyFunctional(PacketPtr other) 1202 { 1203 // all packets that are carrying a payload should have a valid 1204 // data pointer 1205 return trySatisfyFunctional(other, other->getAddr(), other->isSecure(), 1206 other->getSize(), 1207 other->hasData() ? 1208 other->getPtr<uint8_t>() : NULL); 1209 } 1210 1211 /** 1212 * Does the request need to check for cached copies of the same block 1213 * in the memory hierarchy above. 1214 **/ 1215 bool 1216 mustCheckAbove() const 1217 { 1218 return cmd == MemCmd::HardPFReq || isEviction(); 1219 } 1220 1221 /** 1222 * Is this packet a clean eviction, including both actual clean 1223 * evict packets, but also clean writebacks. 1224 */ 1225 bool 1226 isCleanEviction() const 1227 { 1228 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean; 1229 } 1230 1231 /** 1232 * Check a functional request against a memory value represented 1233 * by a base/size pair and an associated data array. If the 1234 * current packet is a read, it may be satisfied by the memory 1235 * value. If the current packet is a write, it may update the 1236 * memory value. 1237 */ 1238 bool 1239 trySatisfyFunctional(Printable *obj, Addr base, bool is_secure, int size, 1240 uint8_t *_data); 1241 1242 /** 1243 * Push label for PrintReq (safe to call unconditionally). 1244 */ 1245 void 1246 pushLabel(const std::string &lbl) 1247 { 1248 if (isPrint()) 1249 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 1250 } 1251 1252 /** 1253 * Pop label for PrintReq (safe to call unconditionally). 1254 */ 1255 void 1256 popLabel() 1257 { 1258 if (isPrint()) 1259 safe_cast<PrintReqState*>(senderState)->popLabel(); 1260 } 1261 1262 void print(std::ostream &o, int verbosity = 0, 1263 const std::string &prefix = "") const; 1264 1265 /** 1266 * A no-args wrapper of print(std::ostream...) 1267 * meant to be invoked from DPRINTFs 1268 * avoiding string overheads in fast mode 1269 * @return string with the request's type and start<->end addresses 1270 */ 1271 std::string print() const; 1272}; 1273 1274#endif //__MEM_PACKET_HH 1275