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