packet.hh revision 11286:2071db8f864b
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 NeedsWritable, //!< Requires writable 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 needsWritable() const { return testCmdAttrib(NeedsWritable); } 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 // Does this packet have sharers (which means it should not be 256 // considered writable) or not. See setHasSharers below. 257 HAS_SHARERS = 0x00000001, 258 259 // Special control flags 260 /// Special timing-mode atomic snoop for multi-level coherence. 261 EXPRESS_SNOOP = 0x00000002, 262 263 /// Allow a responding cache to inform the cache hierarchy 264 /// that it had a writable copy before responding. See 265 /// setResponderHadWritable below. 266 RESPONDER_HAD_WRITABLE = 0x00000004, 267 268 // Snoop co-ordination flag to indicate that a cache is 269 // responding to a snoop. See setCacheResponding below. 270 CACHE_RESPONDING = 0x00000008, 271 272 /// Are the 'addr' and 'size' fields valid? 273 VALID_ADDR = 0x00000100, 274 VALID_SIZE = 0x00000200, 275 276 /// Is the data pointer set to a value that shouldn't be freed 277 /// when the packet is destroyed? 278 STATIC_DATA = 0x00001000, 279 /// The data pointer points to a value that should be freed when 280 /// the packet is destroyed. The pointer is assumed to be pointing 281 /// to an array, and delete [] is consequently called 282 DYNAMIC_DATA = 0x00002000, 283 284 /// suppress the error if this packet encounters a functional 285 /// access failure. 286 SUPPRESS_FUNC_ERROR = 0x00008000, 287 288 // Signal block present to squash prefetch and cache evict packets 289 // through express snoop flag 290 BLOCK_CACHED = 0x00010000 291 }; 292 293 Flags flags; 294 295 public: 296 typedef MemCmd::Command Command; 297 298 /// The command field of the packet. 299 MemCmd cmd; 300 301 /// A pointer to the original request. 302 const RequestPtr req; 303 304 private: 305 /** 306 * A pointer to the data being transfered. It can be differnt 307 * sizes at each level of the heirarchy so it belongs in the 308 * packet, not request. This may or may not be populated when a 309 * responder recieves the packet. If not populated it memory should 310 * be allocated. 311 */ 312 PacketDataPtr data; 313 314 /// The address of the request. This address could be virtual or 315 /// physical, depending on the system configuration. 316 Addr addr; 317 318 /// True if the request targets the secure memory space. 319 bool _isSecure; 320 321 /// The size of the request or transfer. 322 unsigned size; 323 324 /** 325 * Track the bytes found that satisfy a functional read. 326 */ 327 std::vector<bool> bytesValid; 328 329 public: 330 331 /** 332 * The extra delay from seeing the packet until the header is 333 * transmitted. This delay is used to communicate the crossbar 334 * forwarding latency to the neighbouring object (e.g. a cache) 335 * that actually makes the packet wait. As the delay is relative, 336 * a 32-bit unsigned should be sufficient. 337 */ 338 uint32_t headerDelay; 339 340 /** 341 * Keep track of the extra delay incurred by snooping upwards 342 * before sending a request down the memory system. This is used 343 * by the coherent crossbar to account for the additional request 344 * delay. 345 */ 346 uint32_t snoopDelay; 347 348 /** 349 * The extra pipelining delay from seeing the packet until the end of 350 * payload is transmitted by the component that provided it (if 351 * any). This includes the header delay. Similar to the header 352 * delay, this is used to make up for the fact that the 353 * crossbar does not make the packet wait. As the delay is 354 * relative, a 32-bit unsigned should be sufficient. 355 */ 356 uint32_t payloadDelay; 357 358 /** 359 * A virtual base opaque structure used to hold state associated 360 * with the packet (e.g., an MSHR), specific to a MemObject that 361 * sees the packet. A pointer to this state is returned in the 362 * packet's response so that the MemObject in question can quickly 363 * look up the state needed to process it. A specific subclass 364 * would be derived from this to carry state specific to a 365 * particular sending device. 366 * 367 * As multiple MemObjects may add their SenderState throughout the 368 * memory system, the SenderStates create a stack, where a 369 * MemObject can add a new Senderstate, as long as the 370 * predecessing SenderState is restored when the response comes 371 * back. For this reason, the predecessor should always be 372 * populated with the current SenderState of a packet before 373 * modifying the senderState field in the request packet. 374 */ 375 struct SenderState 376 { 377 SenderState* predecessor; 378 SenderState() : predecessor(NULL) {} 379 virtual ~SenderState() {} 380 }; 381 382 /** 383 * Object used to maintain state of a PrintReq. The senderState 384 * field of a PrintReq should always be of this type. 385 */ 386 class PrintReqState : public SenderState 387 { 388 private: 389 /** 390 * An entry in the label stack. 391 */ 392 struct LabelStackEntry 393 { 394 const std::string label; 395 std::string *prefix; 396 bool labelPrinted; 397 LabelStackEntry(const std::string &_label, std::string *_prefix); 398 }; 399 400 typedef std::list<LabelStackEntry> LabelStack; 401 LabelStack labelStack; 402 403 std::string *curPrefixPtr; 404 405 public: 406 std::ostream &os; 407 const int verbosity; 408 409 PrintReqState(std::ostream &os, int verbosity = 0); 410 ~PrintReqState(); 411 412 /** 413 * Returns the current line prefix. 414 */ 415 const std::string &curPrefix() { return *curPrefixPtr; } 416 417 /** 418 * Push a label onto the label stack, and prepend the given 419 * prefix string onto the current prefix. Labels will only be 420 * printed if an object within the label's scope is printed. 421 */ 422 void pushLabel(const std::string &lbl, 423 const std::string &prefix = " "); 424 425 /** 426 * Pop a label off the label stack. 427 */ 428 void popLabel(); 429 430 /** 431 * Print all of the pending unprinted labels on the 432 * stack. Called by printObj(), so normally not called by 433 * users unless bypassing printObj(). 434 */ 435 void printLabels(); 436 437 /** 438 * Print a Printable object to os, because it matched the 439 * address on a PrintReq. 440 */ 441 void printObj(Printable *obj); 442 }; 443 444 /** 445 * This packet's sender state. Devices should use dynamic_cast<> 446 * to cast to the state appropriate to the sender. The intent of 447 * this variable is to allow a device to attach extra information 448 * to a request. A response packet must return the sender state 449 * that was attached to the original request (even if a new packet 450 * is created). 451 */ 452 SenderState *senderState; 453 454 /** 455 * Push a new sender state to the packet and make the current 456 * sender state the predecessor of the new one. This should be 457 * prefered over direct manipulation of the senderState member 458 * variable. 459 * 460 * @param sender_state SenderState to push at the top of the stack 461 */ 462 void pushSenderState(SenderState *sender_state); 463 464 /** 465 * Pop the top of the state stack and return a pointer to it. This 466 * assumes the current sender state is not NULL. This should be 467 * preferred over direct manipulation of the senderState member 468 * variable. 469 * 470 * @return The current top of the stack 471 */ 472 SenderState *popSenderState(); 473 474 /** 475 * Go through the sender state stack and return the first instance 476 * that is of type T (as determined by a dynamic_cast). If there 477 * is no sender state of type T, NULL is returned. 478 * 479 * @return The topmost state of type T 480 */ 481 template <typename T> 482 T * findNextSenderState() const 483 { 484 T *t = NULL; 485 SenderState* sender_state = senderState; 486 while (t == NULL && sender_state != NULL) { 487 t = dynamic_cast<T*>(sender_state); 488 sender_state = sender_state->predecessor; 489 } 490 return t; 491 } 492 493 /// Return the string name of the cmd field (for debugging and 494 /// tracing). 495 const std::string &cmdString() const { return cmd.toString(); } 496 497 /// Return the index of this command. 498 inline int cmdToIndex() const { return cmd.toInt(); } 499 500 bool isRead() const { return cmd.isRead(); } 501 bool isWrite() const { return cmd.isWrite(); } 502 bool isUpgrade() const { return cmd.isUpgrade(); } 503 bool isRequest() const { return cmd.isRequest(); } 504 bool isResponse() const { return cmd.isResponse(); } 505 bool needsWritable() const { return cmd.needsWritable(); } 506 bool needsResponse() const { return cmd.needsResponse(); } 507 bool isInvalidate() const { return cmd.isInvalidate(); } 508 bool isEviction() const { return cmd.isEviction(); } 509 bool isWriteback() const { return cmd.isWriteback(); } 510 bool hasData() const { return cmd.hasData(); } 511 bool hasRespData() const 512 { 513 MemCmd resp_cmd = cmd.responseCommand(); 514 return resp_cmd.hasData(); 515 } 516 bool isLLSC() const { return cmd.isLLSC(); } 517 bool isError() const { return cmd.isError(); } 518 bool isPrint() const { return cmd.isPrint(); } 519 bool isFlush() const { return cmd.isFlush(); } 520 521 //@{ 522 /// Snoop flags 523 /** 524 * Set the cacheResponding flag. This is used by the caches to 525 * signal another cache that they are responding to a request. A 526 * cache will only respond to snoops if it has the line in either 527 * Modified or Owned state. Note that on snoop hits we always pass 528 * the line as Modified and never Owned. In the case of an Owned 529 * line we proceed to invalidate all other copies. 530 * 531 * On a cache fill (see Cache::handleFill), we check hasSharers 532 * first, ignoring the cacheResponding flag if hasSharers is set. 533 * A line is consequently allocated as: 534 * 535 * hasSharers cacheResponding state 536 * true false Shared 537 * true true Shared 538 * false false Exclusive 539 * false true Modified 540 */ 541 void setCacheResponding() 542 { 543 assert(isRequest()); 544 assert(!flags.isSet(CACHE_RESPONDING)); 545 flags.set(CACHE_RESPONDING); 546 } 547 bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); } 548 /** 549 * On fills, the hasSharers flag is used by the caches in 550 * combination with the cacheResponding flag, as clarified 551 * above. If the hasSharers flag is not set, the packet is passing 552 * writable. Thus, a response from a memory passes the line as 553 * writable by default. 554 * 555 * The hasSharers flag is also used by upstream caches to inform a 556 * downstream cache that they have the block (by calling 557 * setHasSharers on snoop request packets that hit in upstream 558 * cachs tags or MSHRs). If the snoop packet has sharers, a 559 * downstream cache is prevented from passing a dirty line upwards 560 * if it was not explicitly asked for a writable copy. See 561 * Cache::satisfyCpuSideRequest. 562 * 563 * The hasSharers flag is also used on writebacks, in 564 * combination with the WritbackClean or WritebackDirty commands, 565 * to allocate the block downstream either as: 566 * 567 * command hasSharers state 568 * WritebackDirty false Modified 569 * WritebackDirty true Owned 570 * WritebackClean false Exclusive 571 * WritebackClean true Shared 572 */ 573 void setHasSharers() { flags.set(HAS_SHARERS); } 574 bool hasSharers() const { return flags.isSet(HAS_SHARERS); } 575 //@} 576 577 /** 578 * The express snoop flag is used for two purposes. Firstly, it is 579 * used to bypass flow control for normal (non-snoop) requests 580 * going downstream in the memory system. In cases where a cache 581 * is responding to a snoop from another cache (it had a dirty 582 * line), but the line is not writable (and there are possibly 583 * other copies), the express snoop flag is set by the downstream 584 * cache to invalidate all other copies in zero time. Secondly, 585 * the express snoop flag is also set to be able to distinguish 586 * snoop packets that came from a downstream cache, rather than 587 * snoop packets from neighbouring caches. 588 */ 589 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 590 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 591 592 /** 593 * On responding to a snoop request (which only happens for 594 * Modified or Owned lines), make sure that we can transform an 595 * Owned response to a Modified one. If this flag is not set, the 596 * responding cache had the line in the Owned state, and there are 597 * possibly other Shared copies in the memory system. A downstream 598 * cache helps in orchestrating the invalidation of these copies 599 * by sending out the appropriate express snoops. 600 */ 601 void setResponderHadWritable() 602 { 603 assert(cacheResponding()); 604 flags.set(RESPONDER_HAD_WRITABLE); 605 } 606 bool responderHadWritable() const 607 { return flags.isSet(RESPONDER_HAD_WRITABLE); } 608 609 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 610 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 611 void setBlockCached() { flags.set(BLOCK_CACHED); } 612 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 613 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 614 615 // Network error conditions... encapsulate them as methods since 616 // their encoding keeps changing (from result field to command 617 // field, etc.) 618 void 619 setBadAddress() 620 { 621 assert(isResponse()); 622 cmd = MemCmd::BadAddressError; 623 } 624 625 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 626 627 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 628 /** 629 * Update the address of this packet mid-transaction. This is used 630 * by the address mapper to change an already set address to a new 631 * one based on the system configuration. It is intended to remap 632 * an existing address, so it asserts that the current address is 633 * valid. 634 */ 635 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 636 637 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 638 639 Addr getOffset(unsigned int blk_size) const 640 { 641 return getAddr() & Addr(blk_size - 1); 642 } 643 644 Addr getBlockAddr(unsigned int blk_size) const 645 { 646 return getAddr() & ~(Addr(blk_size - 1)); 647 } 648 649 bool isSecure() const 650 { 651 assert(flags.isSet(VALID_ADDR)); 652 return _isSecure; 653 } 654 655 /** 656 * It has been determined that the SC packet should successfully update 657 * memory. Therefore, convert this SC packet to a normal write. 658 */ 659 void 660 convertScToWrite() 661 { 662 assert(isLLSC()); 663 assert(isWrite()); 664 cmd = MemCmd::WriteReq; 665 } 666 667 /** 668 * When ruby is in use, Ruby will monitor the cache line and the 669 * phys memory should treat LL ops as normal reads. 670 */ 671 void 672 convertLlToRead() 673 { 674 assert(isLLSC()); 675 assert(isRead()); 676 cmd = MemCmd::ReadReq; 677 } 678 679 /** 680 * Constructor. Note that a Request object must be constructed 681 * first, but the Requests's physical address and size fields need 682 * not be valid. The command must be supplied. 683 */ 684 Packet(const RequestPtr _req, MemCmd _cmd) 685 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 686 size(0), headerDelay(0), snoopDelay(0), payloadDelay(0), 687 senderState(NULL) 688 { 689 if (req->hasPaddr()) { 690 addr = req->getPaddr(); 691 flags.set(VALID_ADDR); 692 _isSecure = req->isSecure(); 693 } 694 if (req->hasSize()) { 695 size = req->getSize(); 696 flags.set(VALID_SIZE); 697 } 698 } 699 700 /** 701 * Alternate constructor if you are trying to create a packet with 702 * a request that is for a whole block, not the address from the 703 * req. this allows for overriding the size/addr of the req. 704 */ 705 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize) 706 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 707 headerDelay(0), snoopDelay(0), payloadDelay(0), 708 senderState(NULL) 709 { 710 if (req->hasPaddr()) { 711 addr = req->getPaddr() & ~(_blkSize - 1); 712 flags.set(VALID_ADDR); 713 _isSecure = req->isSecure(); 714 } 715 size = _blkSize; 716 flags.set(VALID_SIZE); 717 } 718 719 /** 720 * Alternate constructor for copying a packet. Copy all fields 721 * *except* if the original packet's data was dynamic, don't copy 722 * that, as we can't guarantee that the new packet's lifetime is 723 * less than that of the original packet. In this case the new 724 * packet should allocate its own data. 725 */ 726 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 727 : cmd(pkt->cmd), req(pkt->req), 728 data(nullptr), 729 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 730 bytesValid(pkt->bytesValid), 731 headerDelay(pkt->headerDelay), 732 snoopDelay(0), 733 payloadDelay(pkt->payloadDelay), 734 senderState(pkt->senderState) 735 { 736 if (!clear_flags) 737 flags.set(pkt->flags & COPY_FLAGS); 738 739 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 740 741 // should we allocate space for data, or not, the express 742 // snoops do not need to carry any data as they only serve to 743 // co-ordinate state changes 744 if (alloc_data) { 745 // even if asked to allocate data, if the original packet 746 // holds static data, then the sender will not be doing 747 // any memcpy on receiving the response, thus we simply 748 // carry the pointer forward 749 if (pkt->flags.isSet(STATIC_DATA)) { 750 data = pkt->data; 751 flags.set(STATIC_DATA); 752 } else { 753 allocate(); 754 } 755 } 756 } 757 758 /** 759 * Generate the appropriate read MemCmd based on the Request flags. 760 */ 761 static MemCmd 762 makeReadCmd(const RequestPtr req) 763 { 764 if (req->isLLSC()) 765 return MemCmd::LoadLockedReq; 766 else if (req->isPrefetch()) 767 return MemCmd::SoftPFReq; 768 else 769 return MemCmd::ReadReq; 770 } 771 772 /** 773 * Generate the appropriate write MemCmd based on the Request flags. 774 */ 775 static MemCmd 776 makeWriteCmd(const RequestPtr req) 777 { 778 if (req->isLLSC()) 779 return MemCmd::StoreCondReq; 780 else if (req->isSwap()) 781 return MemCmd::SwapReq; 782 else 783 return MemCmd::WriteReq; 784 } 785 786 /** 787 * Constructor-like methods that return Packets based on Request objects. 788 * Fine-tune the MemCmd type if it's not a vanilla read or write. 789 */ 790 static PacketPtr 791 createRead(const RequestPtr req) 792 { 793 return new Packet(req, makeReadCmd(req)); 794 } 795 796 static PacketPtr 797 createWrite(const RequestPtr req) 798 { 799 return new Packet(req, makeWriteCmd(req)); 800 } 801 802 /** 803 * clean up packet variables 804 */ 805 ~Packet() 806 { 807 // Delete the request object if this is a request packet which 808 // does not need a response, because the requester will not get 809 // a chance. If the request packet needs a response then the 810 // request will be deleted on receipt of the response 811 // packet. We also make sure to never delete the request for 812 // express snoops, even for cases when responses are not 813 // needed (CleanEvict and Writeback), since the snoop packet 814 // re-uses the same request. 815 if (req && isRequest() && !needsResponse() && 816 !isExpressSnoop()) { 817 delete req; 818 } 819 deleteData(); 820 } 821 822 /** 823 * Take a request packet and modify it in place to be suitable for 824 * returning as a response to that request. 825 */ 826 void 827 makeResponse() 828 { 829 assert(needsResponse()); 830 assert(isRequest()); 831 cmd = cmd.responseCommand(); 832 833 // responses are never express, even if the snoop that 834 // triggered them was 835 flags.clear(EXPRESS_SNOOP); 836 } 837 838 void 839 makeAtomicResponse() 840 { 841 makeResponse(); 842 } 843 844 void 845 makeTimingResponse() 846 { 847 makeResponse(); 848 } 849 850 void 851 setFunctionalResponseStatus(bool success) 852 { 853 if (!success) { 854 if (isWrite()) { 855 cmd = MemCmd::FunctionalWriteError; 856 } else { 857 cmd = MemCmd::FunctionalReadError; 858 } 859 } 860 } 861 862 void 863 setSize(unsigned size) 864 { 865 assert(!flags.isSet(VALID_SIZE)); 866 867 this->size = size; 868 flags.set(VALID_SIZE); 869 } 870 871 872 public: 873 /** 874 * @{ 875 * @name Data accessor mehtods 876 */ 877 878 /** 879 * Set the data pointer to the following value that should not be 880 * freed. Static data allows us to do a single memcpy even if 881 * multiple packets are required to get from source to destination 882 * and back. In essence the pointer is set calling dataStatic on 883 * the original packet, and whenever this packet is copied and 884 * forwarded the same pointer is passed on. When a packet 885 * eventually reaches the destination holding the data, it is 886 * copied once into the location originally set. On the way back 887 * to the source, no copies are necessary. 888 */ 889 template <typename T> 890 void 891 dataStatic(T *p) 892 { 893 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 894 data = (PacketDataPtr)p; 895 flags.set(STATIC_DATA); 896 } 897 898 /** 899 * Set the data pointer to the following value that should not be 900 * freed. This version of the function allows the pointer passed 901 * to us to be const. To avoid issues down the line we cast the 902 * constness away, the alternative would be to keep both a const 903 * and non-const data pointer and cleverly choose between 904 * them. Note that this is only allowed for static data. 905 */ 906 template <typename T> 907 void 908 dataStaticConst(const T *p) 909 { 910 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 911 data = const_cast<PacketDataPtr>(p); 912 flags.set(STATIC_DATA); 913 } 914 915 /** 916 * Set the data pointer to a value that should have delete [] 917 * called on it. Dynamic data is local to this packet, and as the 918 * packet travels from source to destination, forwarded packets 919 * will allocate their own data. When a packet reaches the final 920 * destination it will populate the dynamic data of that specific 921 * packet, and on the way back towards the source, memcpy will be 922 * invoked in every step where a new packet was created e.g. in 923 * the caches. Ultimately when the response reaches the source a 924 * final memcpy is needed to extract the data from the packet 925 * before it is deallocated. 926 */ 927 template <typename T> 928 void 929 dataDynamic(T *p) 930 { 931 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 932 data = (PacketDataPtr)p; 933 flags.set(DYNAMIC_DATA); 934 } 935 936 /** 937 * get a pointer to the data ptr. 938 */ 939 template <typename T> 940 T* 941 getPtr() 942 { 943 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 944 return (T*)data; 945 } 946 947 template <typename T> 948 const T* 949 getConstPtr() const 950 { 951 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 952 return (const T*)data; 953 } 954 955 /** 956 * Get the data in the packet byte swapped from big endian to 957 * host endian. 958 */ 959 template <typename T> 960 T getBE() const; 961 962 /** 963 * Get the data in the packet byte swapped from little endian to 964 * host endian. 965 */ 966 template <typename T> 967 T getLE() const; 968 969 /** 970 * Get the data in the packet byte swapped from the specified 971 * endianness. 972 */ 973 template <typename T> 974 T get(ByteOrder endian) const; 975 976 /** 977 * Get the data in the packet byte swapped from guest to host 978 * endian. 979 */ 980 template <typename T> 981 T get() const; 982 983 /** Set the value in the data pointer to v as big endian. */ 984 template <typename T> 985 void setBE(T v); 986 987 /** Set the value in the data pointer to v as little endian. */ 988 template <typename T> 989 void setLE(T v); 990 991 /** 992 * Set the value in the data pointer to v using the specified 993 * endianness. 994 */ 995 template <typename T> 996 void set(T v, ByteOrder endian); 997 998 /** Set the value in the data pointer to v as guest endian. */ 999 template <typename T> 1000 void set(T v); 1001 1002 /** 1003 * Copy data into the packet from the provided pointer. 1004 */ 1005 void 1006 setData(const uint8_t *p) 1007 { 1008 // we should never be copying data onto itself, which means we 1009 // must idenfity packets with static data, as they carry the 1010 // same pointer from source to destination and back 1011 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 1012 1013 if (p != getPtr<uint8_t>()) 1014 // for packet with allocated dynamic data, we copy data from 1015 // one to the other, e.g. a forwarded response to a response 1016 std::memcpy(getPtr<uint8_t>(), p, getSize()); 1017 } 1018 1019 /** 1020 * Copy data into the packet from the provided block pointer, 1021 * which is aligned to the given block size. 1022 */ 1023 void 1024 setDataFromBlock(const uint8_t *blk_data, int blkSize) 1025 { 1026 setData(blk_data + getOffset(blkSize)); 1027 } 1028 1029 /** 1030 * Copy data from the packet to the provided block pointer, which 1031 * is aligned to the given block size. 1032 */ 1033 void 1034 writeData(uint8_t *p) const 1035 { 1036 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 1037 } 1038 1039 /** 1040 * Copy data from the packet to the memory at the provided pointer. 1041 */ 1042 void 1043 writeDataToBlock(uint8_t *blk_data, int blkSize) const 1044 { 1045 writeData(blk_data + getOffset(blkSize)); 1046 } 1047 1048 /** 1049 * delete the data pointed to in the data pointer. Ok to call to 1050 * matter how data was allocted. 1051 */ 1052 void 1053 deleteData() 1054 { 1055 if (flags.isSet(DYNAMIC_DATA)) 1056 delete [] data; 1057 1058 flags.clear(STATIC_DATA|DYNAMIC_DATA); 1059 data = NULL; 1060 } 1061 1062 /** Allocate memory for the packet. */ 1063 void 1064 allocate() 1065 { 1066 // if either this command or the response command has a data 1067 // payload, actually allocate space 1068 if (hasData() || hasRespData()) { 1069 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 1070 flags.set(DYNAMIC_DATA); 1071 data = new uint8_t[getSize()]; 1072 } 1073 } 1074 1075 /** @} */ 1076 1077 private: // Private data accessor methods 1078 /** Get the data in the packet without byte swapping. */ 1079 template <typename T> 1080 T getRaw() const; 1081 1082 /** Set the value in the data pointer to v without byte swapping. */ 1083 template <typename T> 1084 void setRaw(T v); 1085 1086 public: 1087 /** 1088 * Check a functional request against a memory value stored in 1089 * another packet (i.e. an in-transit request or 1090 * response). Returns true if the current packet is a read, and 1091 * the other packet provides the data, which is then copied to the 1092 * current packet. If the current packet is a write, and the other 1093 * packet intersects this one, then we update the data 1094 * accordingly. 1095 */ 1096 bool 1097 checkFunctional(PacketPtr other) 1098 { 1099 // all packets that are carrying a payload should have a valid 1100 // data pointer 1101 return checkFunctional(other, other->getAddr(), other->isSecure(), 1102 other->getSize(), 1103 other->hasData() ? 1104 other->getPtr<uint8_t>() : NULL); 1105 } 1106 1107 /** 1108 * Does the request need to check for cached copies of the same block 1109 * in the memory hierarchy above. 1110 **/ 1111 bool 1112 mustCheckAbove() const 1113 { 1114 return cmd == MemCmd::HardPFReq || isEviction(); 1115 } 1116 1117 /** 1118 * Is this packet a clean eviction, including both actual clean 1119 * evict packets, but also clean writebacks. 1120 */ 1121 bool 1122 isCleanEviction() const 1123 { 1124 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean; 1125 } 1126 1127 /** 1128 * Check a functional request against a memory value represented 1129 * by a base/size pair and an associated data array. If the 1130 * current packet is a read, it may be satisfied by the memory 1131 * value. If the current packet is a write, it may update the 1132 * memory value. 1133 */ 1134 bool 1135 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 1136 uint8_t *_data); 1137 1138 /** 1139 * Push label for PrintReq (safe to call unconditionally). 1140 */ 1141 void 1142 pushLabel(const std::string &lbl) 1143 { 1144 if (isPrint()) 1145 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 1146 } 1147 1148 /** 1149 * Pop label for PrintReq (safe to call unconditionally). 1150 */ 1151 void 1152 popLabel() 1153 { 1154 if (isPrint()) 1155 safe_cast<PrintReqState*>(senderState)->popLabel(); 1156 } 1157 1158 void print(std::ostream &o, int verbosity = 0, 1159 const std::string &prefix = "") const; 1160 1161 /** 1162 * A no-args wrapper of print(std::ostream...) 1163 * meant to be invoked from DPRINTFs 1164 * avoiding string overheads in fast mode 1165 * @return string with the request's type and start<->end addresses 1166 */ 1167 std::string print() const; 1168}; 1169 1170#endif //__MEM_PACKET_HH 1171