packet.hh revision 12347
1/* 2 * Copyright (c) 2012-2017 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/logging.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 WriteClean, // writes dirty data below without evicting 92 CleanEvict, 93 SoftPFReq, 94 HardPFReq, 95 SoftPFResp, 96 HardPFResp, 97 WriteLineReq, 98 UpgradeReq, 99 SCUpgradeReq, // Special "weak" upgrade for StoreCond 100 UpgradeResp, 101 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent) 102 UpgradeFailResp, // Valid for SCUpgradeReq only 103 ReadExReq, 104 ReadExResp, 105 ReadCleanReq, 106 ReadSharedReq, 107 LoadLockedReq, 108 StoreCondReq, 109 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent) 110 StoreCondResp, 111 SwapReq, 112 SwapResp, 113 MessageReq, 114 MessageResp, 115 MemFenceReq, 116 MemFenceResp, 117 CleanSharedReq, 118 CleanSharedResp, 119 CleanInvalidReq, 120 CleanInvalidResp, 121 // Error responses 122 // @TODO these should be classified as responses rather than 123 // requests; coding them as requests initially for backwards 124 // compatibility 125 InvalidDestError, // packet dest field invalid 126 BadAddressError, // memory address invalid 127 FunctionalReadError, // unable to fulfill functional read 128 FunctionalWriteError, // unable to fulfill functional write 129 // Fake simulator-only commands 130 PrintReq, // Print state matching address 131 FlushReq, //request for a cache flush 132 InvalidateReq, // request for address to be invalidated 133 InvalidateResp, 134 NUM_MEM_CMDS 135 }; 136 137 private: 138 /** 139 * List of command attributes. 140 */ 141 enum Attribute 142 { 143 IsRead, //!< Data flows from responder to requester 144 IsWrite, //!< Data flows from requester to responder 145 IsUpgrade, 146 IsInvalidate, 147 IsClean, //!< Cleans any existing dirty blocks 148 NeedsWritable, //!< Requires writable copy to complete in-cache 149 IsRequest, //!< Issued by requester 150 IsResponse, //!< Issue by responder 151 NeedsResponse, //!< Requester needs response from target 152 IsEviction, 153 IsSWPrefetch, 154 IsHWPrefetch, 155 IsLlsc, //!< Alpha/MIPS LL or SC access 156 HasData, //!< There is an associated payload 157 IsError, //!< Error response 158 IsPrint, //!< Print state matching address (for debugging) 159 IsFlush, //!< Flush the address from caches 160 FromCache, //!< Request originated from a caching agent 161 NUM_COMMAND_ATTRIBUTES 162 }; 163 164 /** 165 * Structure that defines attributes and other data associated 166 * with a Command. 167 */ 168 struct CommandInfo 169 { 170 /// Set of attribute flags. 171 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 172 /// Corresponding response for requests; InvalidCmd if no 173 /// response is applicable. 174 const Command response; 175 /// String representation (for printing) 176 const std::string str; 177 }; 178 179 /// Array to map Command enum to associated info. 180 static const CommandInfo commandInfo[]; 181 182 private: 183 184 Command cmd; 185 186 bool 187 testCmdAttrib(MemCmd::Attribute attrib) const 188 { 189 return commandInfo[cmd].attributes[attrib] != 0; 190 } 191 192 public: 193 194 bool isRead() const { return testCmdAttrib(IsRead); } 195 bool isWrite() const { return testCmdAttrib(IsWrite); } 196 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); } 197 bool isRequest() const { return testCmdAttrib(IsRequest); } 198 bool isResponse() const { return testCmdAttrib(IsResponse); } 199 bool needsWritable() const { return testCmdAttrib(NeedsWritable); } 200 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 201 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 202 bool isEviction() const { return testCmdAttrib(IsEviction); } 203 bool isClean() const { return testCmdAttrib(IsClean); } 204 bool fromCache() const { return testCmdAttrib(FromCache); } 205 206 /** 207 * A writeback is an eviction that carries data. 208 */ 209 bool isWriteback() const { return testCmdAttrib(IsEviction) && 210 testCmdAttrib(HasData); } 211 212 /** 213 * Check if this particular packet type carries payload data. Note 214 * that this does not reflect if the data pointer of the packet is 215 * valid or not. 216 */ 217 bool hasData() const { return testCmdAttrib(HasData); } 218 bool isLLSC() const { return testCmdAttrib(IsLlsc); } 219 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); } 220 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); } 221 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) || 222 testCmdAttrib(IsHWPrefetch); } 223 bool isError() const { return testCmdAttrib(IsError); } 224 bool isPrint() const { return testCmdAttrib(IsPrint); } 225 bool isFlush() const { return testCmdAttrib(IsFlush); } 226 227 Command 228 responseCommand() const 229 { 230 return commandInfo[cmd].response; 231 } 232 233 /// Return the string to a cmd given by idx. 234 const std::string &toString() const { return commandInfo[cmd].str; } 235 int toInt() const { return (int)cmd; } 236 237 MemCmd(Command _cmd) : cmd(_cmd) { } 238 MemCmd(int _cmd) : cmd((Command)_cmd) { } 239 MemCmd() : cmd(InvalidCmd) { } 240 241 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); } 242 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); } 243}; 244 245/** 246 * A Packet is used to encapsulate a transfer between two objects in 247 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 248 * single Request travels all the way from the requester to the 249 * ultimate destination and back, possibly being conveyed by several 250 * different Packets along the way.) 251 */ 252class Packet : public Printable 253{ 254 public: 255 typedef uint32_t FlagsType; 256 typedef ::Flags<FlagsType> Flags; 257 258 private: 259 260 enum : FlagsType { 261 // Flags to transfer across when copying a packet 262 COPY_FLAGS = 0x0000001F, 263 264 // Does this packet have sharers (which means it should not be 265 // considered writable) or not. See setHasSharers below. 266 HAS_SHARERS = 0x00000001, 267 268 // Special control flags 269 /// Special timing-mode atomic snoop for multi-level coherence. 270 EXPRESS_SNOOP = 0x00000002, 271 272 /// Allow a responding cache to inform the cache hierarchy 273 /// that it had a writable copy before responding. See 274 /// setResponderHadWritable below. 275 RESPONDER_HAD_WRITABLE = 0x00000004, 276 277 // Snoop co-ordination flag to indicate that a cache is 278 // responding to a snoop. See setCacheResponding below. 279 CACHE_RESPONDING = 0x00000008, 280 281 // The writeback/writeclean should be propagated further 282 // downstream by the receiver 283 WRITE_THROUGH = 0x00000010, 284 285 /// Are the 'addr' and 'size' fields valid? 286 VALID_ADDR = 0x00000100, 287 VALID_SIZE = 0x00000200, 288 289 /// Is the data pointer set to a value that shouldn't be freed 290 /// when the packet is destroyed? 291 STATIC_DATA = 0x00001000, 292 /// The data pointer points to a value that should be freed when 293 /// the packet is destroyed. The pointer is assumed to be pointing 294 /// to an array, and delete [] is consequently called 295 DYNAMIC_DATA = 0x00002000, 296 297 /// suppress the error if this packet encounters a functional 298 /// access failure. 299 SUPPRESS_FUNC_ERROR = 0x00008000, 300 301 // Signal block present to squash prefetch and cache evict packets 302 // through express snoop flag 303 BLOCK_CACHED = 0x00010000 304 }; 305 306 Flags flags; 307 308 public: 309 typedef MemCmd::Command Command; 310 311 /// The command field of the packet. 312 MemCmd cmd; 313 314 /// A pointer to the original request. 315 const RequestPtr req; 316 317 private: 318 /** 319 * A pointer to the data being transfered. It can be differnt 320 * sizes at each level of the heirarchy so it belongs in the 321 * packet, not request. This may or may not be populated when a 322 * responder recieves the packet. If not populated it memory should 323 * be allocated. 324 */ 325 PacketDataPtr data; 326 327 /// The address of the request. This address could be virtual or 328 /// physical, depending on the system configuration. 329 Addr addr; 330 331 /// True if the request targets the secure memory space. 332 bool _isSecure; 333 334 /// The size of the request or transfer. 335 unsigned size; 336 337 /** 338 * Track the bytes found that satisfy a functional read. 339 */ 340 std::vector<bool> bytesValid; 341 342 public: 343 344 /** 345 * The extra delay from seeing the packet until the header is 346 * transmitted. This delay is used to communicate the crossbar 347 * forwarding latency to the neighbouring object (e.g. a cache) 348 * that actually makes the packet wait. As the delay is relative, 349 * a 32-bit unsigned should be sufficient. 350 */ 351 uint32_t headerDelay; 352 353 /** 354 * Keep track of the extra delay incurred by snooping upwards 355 * before sending a request down the memory system. This is used 356 * by the coherent crossbar to account for the additional request 357 * delay. 358 */ 359 uint32_t snoopDelay; 360 361 /** 362 * The extra pipelining delay from seeing the packet until the end of 363 * payload is transmitted by the component that provided it (if 364 * any). This includes the header delay. Similar to the header 365 * delay, this is used to make up for the fact that the 366 * crossbar does not make the packet wait. As the delay is 367 * relative, a 32-bit unsigned should be sufficient. 368 */ 369 uint32_t payloadDelay; 370 371 /** 372 * A virtual base opaque structure used to hold state associated 373 * with the packet (e.g., an MSHR), specific to a MemObject that 374 * sees the packet. A pointer to this state is returned in the 375 * packet's response so that the MemObject in question can quickly 376 * look up the state needed to process it. A specific subclass 377 * would be derived from this to carry state specific to a 378 * particular sending device. 379 * 380 * As multiple MemObjects may add their SenderState throughout the 381 * memory system, the SenderStates create a stack, where a 382 * MemObject can add a new Senderstate, as long as the 383 * predecessing SenderState is restored when the response comes 384 * back. For this reason, the predecessor should always be 385 * populated with the current SenderState of a packet before 386 * modifying the senderState field in the request packet. 387 */ 388 struct SenderState 389 { 390 SenderState* predecessor; 391 SenderState() : predecessor(NULL) {} 392 virtual ~SenderState() {} 393 }; 394 395 /** 396 * Object used to maintain state of a PrintReq. The senderState 397 * field of a PrintReq should always be of this type. 398 */ 399 class PrintReqState : public SenderState 400 { 401 private: 402 /** 403 * An entry in the label stack. 404 */ 405 struct LabelStackEntry 406 { 407 const std::string label; 408 std::string *prefix; 409 bool labelPrinted; 410 LabelStackEntry(const std::string &_label, std::string *_prefix); 411 }; 412 413 typedef std::list<LabelStackEntry> LabelStack; 414 LabelStack labelStack; 415 416 std::string *curPrefixPtr; 417 418 public: 419 std::ostream &os; 420 const int verbosity; 421 422 PrintReqState(std::ostream &os, int verbosity = 0); 423 ~PrintReqState(); 424 425 /** 426 * Returns the current line prefix. 427 */ 428 const std::string &curPrefix() { return *curPrefixPtr; } 429 430 /** 431 * Push a label onto the label stack, and prepend the given 432 * prefix string onto the current prefix. Labels will only be 433 * printed if an object within the label's scope is printed. 434 */ 435 void pushLabel(const std::string &lbl, 436 const std::string &prefix = " "); 437 438 /** 439 * Pop a label off the label stack. 440 */ 441 void popLabel(); 442 443 /** 444 * Print all of the pending unprinted labels on the 445 * stack. Called by printObj(), so normally not called by 446 * users unless bypassing printObj(). 447 */ 448 void printLabels(); 449 450 /** 451 * Print a Printable object to os, because it matched the 452 * address on a PrintReq. 453 */ 454 void printObj(Printable *obj); 455 }; 456 457 /** 458 * This packet's sender state. Devices should use dynamic_cast<> 459 * to cast to the state appropriate to the sender. The intent of 460 * this variable is to allow a device to attach extra information 461 * to a request. A response packet must return the sender state 462 * that was attached to the original request (even if a new packet 463 * is created). 464 */ 465 SenderState *senderState; 466 467 /** 468 * Push a new sender state to the packet and make the current 469 * sender state the predecessor of the new one. This should be 470 * prefered over direct manipulation of the senderState member 471 * variable. 472 * 473 * @param sender_state SenderState to push at the top of the stack 474 */ 475 void pushSenderState(SenderState *sender_state); 476 477 /** 478 * Pop the top of the state stack and return a pointer to it. This 479 * assumes the current sender state is not NULL. This should be 480 * preferred over direct manipulation of the senderState member 481 * variable. 482 * 483 * @return The current top of the stack 484 */ 485 SenderState *popSenderState(); 486 487 /** 488 * Go through the sender state stack and return the first instance 489 * that is of type T (as determined by a dynamic_cast). If there 490 * is no sender state of type T, NULL is returned. 491 * 492 * @return The topmost state of type T 493 */ 494 template <typename T> 495 T * findNextSenderState() const 496 { 497 T *t = NULL; 498 SenderState* sender_state = senderState; 499 while (t == NULL && sender_state != NULL) { 500 t = dynamic_cast<T*>(sender_state); 501 sender_state = sender_state->predecessor; 502 } 503 return t; 504 } 505 506 /// Return the string name of the cmd field (for debugging and 507 /// tracing). 508 const std::string &cmdString() const { return cmd.toString(); } 509 510 /// Return the index of this command. 511 inline int cmdToIndex() const { return cmd.toInt(); } 512 513 bool isRead() const { return cmd.isRead(); } 514 bool isWrite() const { return cmd.isWrite(); } 515 bool isUpgrade() const { return cmd.isUpgrade(); } 516 bool isRequest() const { return cmd.isRequest(); } 517 bool isResponse() const { return cmd.isResponse(); } 518 bool needsWritable() const 519 { 520 // we should never check if a response needsWritable, the 521 // request has this flag, and for a response we should rather 522 // look at the hasSharers flag (if not set, the response is to 523 // be considered writable) 524 assert(isRequest()); 525 return cmd.needsWritable(); 526 } 527 bool needsResponse() const { return cmd.needsResponse(); } 528 bool isInvalidate() const { return cmd.isInvalidate(); } 529 bool isEviction() const { return cmd.isEviction(); } 530 bool isClean() const { return cmd.isClean(); } 531 bool fromCache() const { return cmd.fromCache(); } 532 bool isWriteback() const { return cmd.isWriteback(); } 533 bool hasData() const { return cmd.hasData(); } 534 bool hasRespData() const 535 { 536 MemCmd resp_cmd = cmd.responseCommand(); 537 return resp_cmd.hasData(); 538 } 539 bool isLLSC() const { return cmd.isLLSC(); } 540 bool isError() const { return cmd.isError(); } 541 bool isPrint() const { return cmd.isPrint(); } 542 bool isFlush() const { return cmd.isFlush(); } 543 544 //@{ 545 /// Snoop flags 546 /** 547 * Set the cacheResponding flag. This is used by the caches to 548 * signal another cache that they are responding to a request. A 549 * cache will only respond to snoops if it has the line in either 550 * Modified or Owned state. Note that on snoop hits we always pass 551 * the line as Modified and never Owned. In the case of an Owned 552 * line we proceed to invalidate all other copies. 553 * 554 * On a cache fill (see Cache::handleFill), we check hasSharers 555 * first, ignoring the cacheResponding flag if hasSharers is set. 556 * A line is consequently allocated as: 557 * 558 * hasSharers cacheResponding state 559 * true false Shared 560 * true true Shared 561 * false false Exclusive 562 * false true Modified 563 */ 564 void setCacheResponding() 565 { 566 assert(isRequest()); 567 assert(!flags.isSet(CACHE_RESPONDING)); 568 flags.set(CACHE_RESPONDING); 569 } 570 bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); } 571 /** 572 * On fills, the hasSharers flag is used by the caches in 573 * combination with the cacheResponding flag, as clarified 574 * above. If the hasSharers flag is not set, the packet is passing 575 * writable. Thus, a response from a memory passes the line as 576 * writable by default. 577 * 578 * The hasSharers flag is also used by upstream caches to inform a 579 * downstream cache that they have the block (by calling 580 * setHasSharers on snoop request packets that hit in upstream 581 * cachs tags or MSHRs). If the snoop packet has sharers, a 582 * downstream cache is prevented from passing a dirty line upwards 583 * if it was not explicitly asked for a writable copy. See 584 * Cache::satisfyCpuSideRequest. 585 * 586 * The hasSharers flag is also used on writebacks, in 587 * combination with the WritbackClean or WritebackDirty commands, 588 * to allocate the block downstream either as: 589 * 590 * command hasSharers state 591 * WritebackDirty false Modified 592 * WritebackDirty true Owned 593 * WritebackClean false Exclusive 594 * WritebackClean true Shared 595 */ 596 void setHasSharers() { flags.set(HAS_SHARERS); } 597 bool hasSharers() const { return flags.isSet(HAS_SHARERS); } 598 //@} 599 600 /** 601 * The express snoop flag is used for two purposes. Firstly, it is 602 * used to bypass flow control for normal (non-snoop) requests 603 * going downstream in the memory system. In cases where a cache 604 * is responding to a snoop from another cache (it had a dirty 605 * line), but the line is not writable (and there are possibly 606 * other copies), the express snoop flag is set by the downstream 607 * cache to invalidate all other copies in zero time. Secondly, 608 * the express snoop flag is also set to be able to distinguish 609 * snoop packets that came from a downstream cache, rather than 610 * snoop packets from neighbouring caches. 611 */ 612 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 613 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 614 615 /** 616 * On responding to a snoop request (which only happens for 617 * Modified or Owned lines), make sure that we can transform an 618 * Owned response to a Modified one. If this flag is not set, the 619 * responding cache had the line in the Owned state, and there are 620 * possibly other Shared copies in the memory system. A downstream 621 * cache helps in orchestrating the invalidation of these copies 622 * by sending out the appropriate express snoops. 623 */ 624 void setResponderHadWritable() 625 { 626 assert(cacheResponding()); 627 assert(!responderHadWritable()); 628 flags.set(RESPONDER_HAD_WRITABLE); 629 } 630 bool responderHadWritable() const 631 { return flags.isSet(RESPONDER_HAD_WRITABLE); } 632 633 /** 634 * A writeback/writeclean cmd gets propagated further downstream 635 * by the receiver when the flag is set. 636 */ 637 void setWriteThrough() 638 { 639 assert(cmd.isWrite() && 640 (cmd.isEviction() || cmd == MemCmd::WriteClean)); 641 flags.set(WRITE_THROUGH); 642 } 643 void clearWriteThrough() { flags.clear(WRITE_THROUGH); } 644 bool writeThrough() const { return flags.isSet(WRITE_THROUGH); } 645 646 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 647 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 648 void setBlockCached() { flags.set(BLOCK_CACHED); } 649 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 650 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 651 652 // Network error conditions... encapsulate them as methods since 653 // their encoding keeps changing (from result field to command 654 // field, etc.) 655 void 656 setBadAddress() 657 { 658 assert(isResponse()); 659 cmd = MemCmd::BadAddressError; 660 } 661 662 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 663 664 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 665 /** 666 * Update the address of this packet mid-transaction. This is used 667 * by the address mapper to change an already set address to a new 668 * one based on the system configuration. It is intended to remap 669 * an existing address, so it asserts that the current address is 670 * valid. 671 */ 672 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 673 674 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 675 676 Addr getOffset(unsigned int blk_size) const 677 { 678 return getAddr() & Addr(blk_size - 1); 679 } 680 681 Addr getBlockAddr(unsigned int blk_size) const 682 { 683 return getAddr() & ~(Addr(blk_size - 1)); 684 } 685 686 bool isSecure() const 687 { 688 assert(flags.isSet(VALID_ADDR)); 689 return _isSecure; 690 } 691 692 /** 693 * Accessor function to atomic op. 694 */ 695 AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); } 696 bool isAtomicOp() const { return req->isAtomic(); } 697 698 /** 699 * It has been determined that the SC packet should successfully update 700 * memory. Therefore, convert this SC packet to a normal write. 701 */ 702 void 703 convertScToWrite() 704 { 705 assert(isLLSC()); 706 assert(isWrite()); 707 cmd = MemCmd::WriteReq; 708 } 709 710 /** 711 * When ruby is in use, Ruby will monitor the cache line and the 712 * phys memory should treat LL ops as normal reads. 713 */ 714 void 715 convertLlToRead() 716 { 717 assert(isLLSC()); 718 assert(isRead()); 719 cmd = MemCmd::ReadReq; 720 } 721 722 /** 723 * Constructor. Note that a Request object must be constructed 724 * first, but the Requests's physical address and size fields need 725 * not be valid. The command must be supplied. 726 */ 727 Packet(const RequestPtr _req, MemCmd _cmd) 728 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 729 size(0), headerDelay(0), snoopDelay(0), payloadDelay(0), 730 senderState(NULL) 731 { 732 if (req->hasPaddr()) { 733 addr = req->getPaddr(); 734 flags.set(VALID_ADDR); 735 _isSecure = req->isSecure(); 736 } 737 if (req->hasSize()) { 738 size = req->getSize(); 739 flags.set(VALID_SIZE); 740 } 741 } 742 743 /** 744 * Alternate constructor if you are trying to create a packet with 745 * a request that is for a whole block, not the address from the 746 * req. this allows for overriding the size/addr of the req. 747 */ 748 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize) 749 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 750 headerDelay(0), snoopDelay(0), payloadDelay(0), 751 senderState(NULL) 752 { 753 if (req->hasPaddr()) { 754 addr = req->getPaddr() & ~(_blkSize - 1); 755 flags.set(VALID_ADDR); 756 _isSecure = req->isSecure(); 757 } 758 size = _blkSize; 759 flags.set(VALID_SIZE); 760 } 761 762 /** 763 * Alternate constructor for copying a packet. Copy all fields 764 * *except* if the original packet's data was dynamic, don't copy 765 * that, as we can't guarantee that the new packet's lifetime is 766 * less than that of the original packet. In this case the new 767 * packet should allocate its own data. 768 */ 769 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 770 : cmd(pkt->cmd), req(pkt->req), 771 data(nullptr), 772 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 773 bytesValid(pkt->bytesValid), 774 headerDelay(pkt->headerDelay), 775 snoopDelay(0), 776 payloadDelay(pkt->payloadDelay), 777 senderState(pkt->senderState) 778 { 779 if (!clear_flags) 780 flags.set(pkt->flags & COPY_FLAGS); 781 782 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 783 784 // should we allocate space for data, or not, the express 785 // snoops do not need to carry any data as they only serve to 786 // co-ordinate state changes 787 if (alloc_data) { 788 // even if asked to allocate data, if the original packet 789 // holds static data, then the sender will not be doing 790 // any memcpy on receiving the response, thus we simply 791 // carry the pointer forward 792 if (pkt->flags.isSet(STATIC_DATA)) { 793 data = pkt->data; 794 flags.set(STATIC_DATA); 795 } else { 796 allocate(); 797 } 798 } 799 } 800 801 /** 802 * Generate the appropriate read MemCmd based on the Request flags. 803 */ 804 static MemCmd 805 makeReadCmd(const RequestPtr req) 806 { 807 if (req->isLLSC()) 808 return MemCmd::LoadLockedReq; 809 else if (req->isPrefetch()) 810 return MemCmd::SoftPFReq; 811 else 812 return MemCmd::ReadReq; 813 } 814 815 /** 816 * Generate the appropriate write MemCmd based on the Request flags. 817 */ 818 static MemCmd 819 makeWriteCmd(const RequestPtr req) 820 { 821 if (req->isLLSC()) 822 return MemCmd::StoreCondReq; 823 else if (req->isSwap()) 824 return MemCmd::SwapReq; 825 else if (req->isCacheInvalidate()) { 826 return req->isCacheClean() ? MemCmd::CleanInvalidReq : 827 MemCmd::InvalidateReq; 828 } else if (req->isCacheClean()) { 829 return MemCmd::CleanSharedReq; 830 } else 831 return MemCmd::WriteReq; 832 } 833 834 /** 835 * Constructor-like methods that return Packets based on Request objects. 836 * Fine-tune the MemCmd type if it's not a vanilla read or write. 837 */ 838 static PacketPtr 839 createRead(const RequestPtr req) 840 { 841 return new Packet(req, makeReadCmd(req)); 842 } 843 844 static PacketPtr 845 createWrite(const RequestPtr req) 846 { 847 return new Packet(req, makeWriteCmd(req)); 848 } 849 850 /** 851 * clean up packet variables 852 */ 853 ~Packet() 854 { 855 // Delete the request object if this is a request packet which 856 // does not need a response, because the requester will not get 857 // a chance. If the request packet needs a response then the 858 // request will be deleted on receipt of the response 859 // packet. We also make sure to never delete the request for 860 // express snoops, even for cases when responses are not 861 // needed (CleanEvict and Writeback), since the snoop packet 862 // re-uses the same request. 863 if (req && isRequest() && !needsResponse() && 864 !isExpressSnoop()) { 865 delete req; 866 } 867 deleteData(); 868 } 869 870 /** 871 * Take a request packet and modify it in place to be suitable for 872 * returning as a response to that request. 873 */ 874 void 875 makeResponse() 876 { 877 assert(needsResponse()); 878 assert(isRequest()); 879 cmd = cmd.responseCommand(); 880 881 // responses are never express, even if the snoop that 882 // triggered them was 883 flags.clear(EXPRESS_SNOOP); 884 } 885 886 void 887 makeAtomicResponse() 888 { 889 makeResponse(); 890 } 891 892 void 893 makeTimingResponse() 894 { 895 makeResponse(); 896 } 897 898 void 899 setFunctionalResponseStatus(bool success) 900 { 901 if (!success) { 902 if (isWrite()) { 903 cmd = MemCmd::FunctionalWriteError; 904 } else { 905 cmd = MemCmd::FunctionalReadError; 906 } 907 } 908 } 909 910 void 911 setSize(unsigned size) 912 { 913 assert(!flags.isSet(VALID_SIZE)); 914 915 this->size = size; 916 flags.set(VALID_SIZE); 917 } 918 919 920 public: 921 /** 922 * @{ 923 * @name Data accessor mehtods 924 */ 925 926 /** 927 * Set the data pointer to the following value that should not be 928 * freed. Static data allows us to do a single memcpy even if 929 * multiple packets are required to get from source to destination 930 * and back. In essence the pointer is set calling dataStatic on 931 * the original packet, and whenever this packet is copied and 932 * forwarded the same pointer is passed on. When a packet 933 * eventually reaches the destination holding the data, it is 934 * copied once into the location originally set. On the way back 935 * to the source, no copies are necessary. 936 */ 937 template <typename T> 938 void 939 dataStatic(T *p) 940 { 941 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 942 data = (PacketDataPtr)p; 943 flags.set(STATIC_DATA); 944 } 945 946 /** 947 * Set the data pointer to the following value that should not be 948 * freed. This version of the function allows the pointer passed 949 * to us to be const. To avoid issues down the line we cast the 950 * constness away, the alternative would be to keep both a const 951 * and non-const data pointer and cleverly choose between 952 * them. Note that this is only allowed for static data. 953 */ 954 template <typename T> 955 void 956 dataStaticConst(const T *p) 957 { 958 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 959 data = const_cast<PacketDataPtr>(p); 960 flags.set(STATIC_DATA); 961 } 962 963 /** 964 * Set the data pointer to a value that should have delete [] 965 * called on it. Dynamic data is local to this packet, and as the 966 * packet travels from source to destination, forwarded packets 967 * will allocate their own data. When a packet reaches the final 968 * destination it will populate the dynamic data of that specific 969 * packet, and on the way back towards the source, memcpy will be 970 * invoked in every step where a new packet was created e.g. in 971 * the caches. Ultimately when the response reaches the source a 972 * final memcpy is needed to extract the data from the packet 973 * before it is deallocated. 974 */ 975 template <typename T> 976 void 977 dataDynamic(T *p) 978 { 979 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 980 data = (PacketDataPtr)p; 981 flags.set(DYNAMIC_DATA); 982 } 983 984 /** 985 * get a pointer to the data ptr. 986 */ 987 template <typename T> 988 T* 989 getPtr() 990 { 991 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 992 return (T*)data; 993 } 994 995 template <typename T> 996 const T* 997 getConstPtr() const 998 { 999 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 1000 return (const T*)data; 1001 } 1002 1003 /** 1004 * Get the data in the packet byte swapped from big endian to 1005 * host endian. 1006 */ 1007 template <typename T> 1008 T getBE() const; 1009 1010 /** 1011 * Get the data in the packet byte swapped from little endian to 1012 * host endian. 1013 */ 1014 template <typename T> 1015 T getLE() const; 1016 1017 /** 1018 * Get the data in the packet byte swapped from the specified 1019 * endianness. 1020 */ 1021 template <typename T> 1022 T get(ByteOrder endian) const; 1023 1024 /** 1025 * Get the data in the packet byte swapped from guest to host 1026 * endian. 1027 */ 1028 template <typename T> 1029 T get() const; 1030 1031 /** Set the value in the data pointer to v as big endian. */ 1032 template <typename T> 1033 void setBE(T v); 1034 1035 /** Set the value in the data pointer to v as little endian. */ 1036 template <typename T> 1037 void setLE(T v); 1038 1039 /** 1040 * Set the value in the data pointer to v using the specified 1041 * endianness. 1042 */ 1043 template <typename T> 1044 void set(T v, ByteOrder endian); 1045 1046 /** Set the value in the data pointer to v as guest endian. */ 1047 template <typename T> 1048 void set(T v); 1049 1050 /** 1051 * Copy data into the packet from the provided pointer. 1052 */ 1053 void 1054 setData(const uint8_t *p) 1055 { 1056 // we should never be copying data onto itself, which means we 1057 // must idenfity packets with static data, as they carry the 1058 // same pointer from source to destination and back 1059 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 1060 1061 if (p != getPtr<uint8_t>()) 1062 // for packet with allocated dynamic data, we copy data from 1063 // one to the other, e.g. a forwarded response to a response 1064 std::memcpy(getPtr<uint8_t>(), p, getSize()); 1065 } 1066 1067 /** 1068 * Copy data into the packet from the provided block pointer, 1069 * which is aligned to the given block size. 1070 */ 1071 void 1072 setDataFromBlock(const uint8_t *blk_data, int blkSize) 1073 { 1074 setData(blk_data + getOffset(blkSize)); 1075 } 1076 1077 /** 1078 * Copy data from the packet to the provided block pointer, which 1079 * is aligned to the given block size. 1080 */ 1081 void 1082 writeData(uint8_t *p) const 1083 { 1084 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 1085 } 1086 1087 /** 1088 * Copy data from the packet to the memory at the provided pointer. 1089 */ 1090 void 1091 writeDataToBlock(uint8_t *blk_data, int blkSize) const 1092 { 1093 writeData(blk_data + getOffset(blkSize)); 1094 } 1095 1096 /** 1097 * delete the data pointed to in the data pointer. Ok to call to 1098 * matter how data was allocted. 1099 */ 1100 void 1101 deleteData() 1102 { 1103 if (flags.isSet(DYNAMIC_DATA)) 1104 delete [] data; 1105 1106 flags.clear(STATIC_DATA|DYNAMIC_DATA); 1107 data = NULL; 1108 } 1109 1110 /** Allocate memory for the packet. */ 1111 void 1112 allocate() 1113 { 1114 // if either this command or the response command has a data 1115 // payload, actually allocate space 1116 if (hasData() || hasRespData()) { 1117 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 1118 flags.set(DYNAMIC_DATA); 1119 data = new uint8_t[getSize()]; 1120 } 1121 } 1122 1123 /** @} */ 1124 1125 private: // Private data accessor methods 1126 /** Get the data in the packet without byte swapping. */ 1127 template <typename T> 1128 T getRaw() const; 1129 1130 /** Set the value in the data pointer to v without byte swapping. */ 1131 template <typename T> 1132 void setRaw(T v); 1133 1134 public: 1135 /** 1136 * Check a functional request against a memory value stored in 1137 * another packet (i.e. an in-transit request or 1138 * response). Returns true if the current packet is a read, and 1139 * the other packet provides the data, which is then copied to the 1140 * current packet. If the current packet is a write, and the other 1141 * packet intersects this one, then we update the data 1142 * accordingly. 1143 */ 1144 bool 1145 checkFunctional(PacketPtr other) 1146 { 1147 // all packets that are carrying a payload should have a valid 1148 // data pointer 1149 return checkFunctional(other, other->getAddr(), other->isSecure(), 1150 other->getSize(), 1151 other->hasData() ? 1152 other->getPtr<uint8_t>() : NULL); 1153 } 1154 1155 /** 1156 * Does the request need to check for cached copies of the same block 1157 * in the memory hierarchy above. 1158 **/ 1159 bool 1160 mustCheckAbove() const 1161 { 1162 return cmd == MemCmd::HardPFReq || isEviction(); 1163 } 1164 1165 /** 1166 * Is this packet a clean eviction, including both actual clean 1167 * evict packets, but also clean writebacks. 1168 */ 1169 bool 1170 isCleanEviction() const 1171 { 1172 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean; 1173 } 1174 1175 /** 1176 * Check a functional request against a memory value represented 1177 * by a base/size pair and an associated data array. If the 1178 * current packet is a read, it may be satisfied by the memory 1179 * value. If the current packet is a write, it may update the 1180 * memory value. 1181 */ 1182 bool 1183 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 1184 uint8_t *_data); 1185 1186 /** 1187 * Push label for PrintReq (safe to call unconditionally). 1188 */ 1189 void 1190 pushLabel(const std::string &lbl) 1191 { 1192 if (isPrint()) 1193 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 1194 } 1195 1196 /** 1197 * Pop label for PrintReq (safe to call unconditionally). 1198 */ 1199 void 1200 popLabel() 1201 { 1202 if (isPrint()) 1203 safe_cast<PrintReqState*>(senderState)->popLabel(); 1204 } 1205 1206 void print(std::ostream &o, int verbosity = 0, 1207 const std::string &prefix = "") const; 1208 1209 /** 1210 * A no-args wrapper of print(std::ostream...) 1211 * meant to be invoked from DPRINTFs 1212 * avoiding string overheads in fast mode 1213 * @return string with the request's type and start<->end addresses 1214 */ 1215 std::string print() const; 1216}; 1217 1218#endif //__MEM_PACKET_HH 1219