1/*
2 * Copyright (c) 2012-2014 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 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 Writeback,
90 SoftPFReq,
91 HardPFReq,
92 SoftPFResp,
93 HardPFResp,
94 WriteInvalidateReq,
95 WriteInvalidateResp,
96 UpgradeReq,
97 SCUpgradeReq, // Special "weak" upgrade for StoreCond
98 UpgradeResp,
99 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent)
100 UpgradeFailResp, // Valid for SCUpgradeReq only
101 ReadExReq,
102 ReadExResp,
103 LoadLockedReq,
104 StoreCondReq,
105 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent)
106 StoreCondResp,
107 SwapReq,
108 SwapResp,
109 MessageReq,
110 MessageResp,
111 // Error responses
112 // @TODO these should be classified as responses rather than
113 // requests; coding them as requests initially for backwards
114 // compatibility
115 InvalidDestError, // packet dest field invalid
116 BadAddressError, // memory address invalid
117 FunctionalReadError, // unable to fulfill functional read
118 FunctionalWriteError, // unable to fulfill functional write
119 // Fake simulator-only commands
120 PrintReq, // Print state matching address
121 FlushReq, //request for a cache flush
122 InvalidationReq, // request for address to be invalidated from lsq
123 NUM_MEM_CMDS
124 };
125
126 private:
127 /**
128 * List of command attributes.
129 */
130 enum Attribute
131 {
132 IsRead, //!< Data flows from responder to requester
133 IsWrite, //!< Data flows from requester to responder
134 IsUpgrade,
135 IsInvalidate,
136 NeedsExclusive, //!< Requires exclusive copy to complete in-cache
137 IsRequest, //!< Issued by requester
138 IsResponse, //!< Issue by responder
139 NeedsResponse, //!< Requester needs response from target
140 IsSWPrefetch,
141 IsHWPrefetch,
142 IsLlsc, //!< Alpha/MIPS LL or SC access
143 HasData, //!< There is an associated payload
144 IsError, //!< Error response
145 IsPrint, //!< Print state matching address (for debugging)
146 IsFlush, //!< Flush the address from caches
147 NUM_COMMAND_ATTRIBUTES
148 };
149
150 /**
151 * Structure that defines attributes and other data associated
152 * with a Command.
153 */
154 struct CommandInfo
155 {
156 /// Set of attribute flags.
157 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
158 /// Corresponding response for requests; InvalidCmd if no
159 /// response is applicable.
160 const Command response;
161 /// String representation (for printing)
162 const std::string str;
163 };
164
165 /// Array to map Command enum to associated info.
166 static const CommandInfo commandInfo[];
167
168 private:
169
170 Command cmd;
171
172 bool
173 testCmdAttrib(MemCmd::Attribute attrib) const
174 {
175 return commandInfo[cmd].attributes[attrib] != 0;
176 }
177
178 public:
179
180 bool isRead() const { return testCmdAttrib(IsRead); }
181 bool isWrite() const { return testCmdAttrib(IsWrite); }
182 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); }
183 bool isRequest() const { return testCmdAttrib(IsRequest); }
184 bool isResponse() const { return testCmdAttrib(IsResponse); }
185 bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); }
186 bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
187 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
188
189 /**
190 * Check if this particular packet type carries payload data. Note
191 * that this does not reflect if the data pointer of the packet is
192 * valid or not.
193 */
194 bool hasData() const { return testCmdAttrib(HasData); }
195 bool isLLSC() const { return testCmdAttrib(IsLlsc); }
196 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); }
197 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); }
198 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) ||
199 testCmdAttrib(IsHWPrefetch); }
200 bool isError() const { return testCmdAttrib(IsError); }
201 bool isPrint() const { return testCmdAttrib(IsPrint); }
202 bool isFlush() const { return testCmdAttrib(IsFlush); }
203
204 const Command
205 responseCommand() const
206 {
207 return commandInfo[cmd].response;
208 }
209
210 /// Return the string to a cmd given by idx.
211 const std::string &toString() const { return commandInfo[cmd].str; }
212 int toInt() const { return (int)cmd; }
213
214 MemCmd(Command _cmd) : cmd(_cmd) { }
215 MemCmd(int _cmd) : cmd((Command)_cmd) { }
216 MemCmd() : cmd(InvalidCmd) { }
217
218 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
219 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
220};
221
222/**
223 * A Packet is used to encapsulate a transfer between two objects in
224 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
225 * single Request travels all the way from the requester to the
226 * ultimate destination and back, possibly being conveyed by several
227 * different Packets along the way.)
228 */
229class Packet : public Printable
230{
231 public:
232 typedef uint32_t FlagsType;
233 typedef ::Flags<FlagsType> Flags;
234
235 private:
236 static const FlagsType PUBLIC_FLAGS = 0x00000000;
237 static const FlagsType PRIVATE_FLAGS = 0x00007F0F;
238 static const FlagsType COPY_FLAGS = 0x0000000F;
239
240 static const FlagsType SHARED = 0x00000001;
241 // Special control flags
242 /// Special timing-mode atomic snoop for multi-level coherence.
243 static const FlagsType EXPRESS_SNOOP = 0x00000002;
244 /// Does supplier have exclusive copy?
245 /// Useful for multi-level coherence.
246 static const FlagsType SUPPLY_EXCLUSIVE = 0x00000004;
247 // Snoop response flags
248 static const FlagsType MEM_INHIBIT = 0x00000008;
249 /// Are the 'addr' and 'size' fields valid?
250 static const FlagsType VALID_ADDR = 0x00000100;
251 static const FlagsType VALID_SIZE = 0x00000200;
252 /// Is the data pointer set to a value that shouldn't be freed
253 /// when the packet is destroyed?
254 static const FlagsType STATIC_DATA = 0x00001000;
255 /// The data pointer points to a value that should be freed when
256 /// the packet is destroyed. The pointer is assumed to be pointing
257 /// to an array, and delete [] is consequently called
258 static const FlagsType DYNAMIC_DATA = 0x00002000;
259 /// suppress the error if this packet encounters a functional
260 /// access failure.
261 static const FlagsType SUPPRESS_FUNC_ERROR = 0x00008000;
262 // Signal prefetch squash through express snoop flag
263 static const FlagsType PREFETCH_SNOOP_SQUASH = 0x00010000;
264
265 Flags flags;
266
267 public:
268 typedef MemCmd::Command Command;
269
270 /// The command field of the packet.
271 MemCmd cmd;
272
273 /// A pointer to the original request.
274 const RequestPtr req;
275
276 private:
277 /**
278 * A pointer to the data being transfered. It can be differnt
279 * sizes at each level of the heirarchy so it belongs in the
280 * packet, not request. This may or may not be populated when a
281 * responder recieves the packet. If not populated it memory should
282 * be allocated.
283 */
284 PacketDataPtr data;
285
286 /// The address of the request. This address could be virtual or
287 /// physical, depending on the system configuration.
288 Addr addr;
289
290 /// True if the request targets the secure memory space.
291 bool _isSecure;
292
293 /// The size of the request or transfer.
294 unsigned size;
295
296 /**
297 * Source port identifier set on a request packet to enable
298 * appropriate routing of the responses. The source port
299 * identifier is set by any multiplexing component, e.g. a
300 * crossbar, as the timing responses need this information to be
301 * routed back to the appropriate port at a later point in
302 * time. The field can be updated (over-written) as the request
303 * packet passes through additional multiplexing components, and
304 * it is their responsibility to remember the original source port
305 * identifier, for example by using an appropriate sender
306 * state. The latter is done in the cache and bridge.
307 */
308 PortID src;
309
310 /**
311 * Destination port identifier that is present on all response
312 * packets that passed through a multiplexing component as a
313 * request packet. The source port identifier is turned into a
314 * destination port identifier when the packet is turned into a
315 * response, and the destination is used, e.g. by the crossbar, to
316 * select the appropriate path through the interconnect.
317 */
318 PortID dest;
319
320 /**
321 * The original value of the command field. Only valid when the
322 * current command field is an error condition; in that case, the
323 * previous contents of the command field are copied here. This
324 * field is *not* set on non-error responses.
325 */
326 MemCmd origCmd;
327
328 /**
329 * These values specify the range of bytes found that satisfy a
330 * functional read.
331 */
332 uint16_t bytesValidStart;
333 uint16_t bytesValidEnd;
334
335 public:
336
337 /**
338 * The extra delay from seeing the packet until the first word is
339 * transmitted. This delay is used to communicate the crossbar
340 * forwarding latency to the neighbouring object (e.g. a cache)
341 * that actually makes the packet wait. As the delay is relative,
342 * a 32-bit unsigned should be sufficient.
343 */
344 uint32_t firstWordDelay;
345
346 /**
347 * The extra pipelining delay from seeing the packet until the
348 * last word is transmitted by the component that provided it (if
349 * any). This includes the first word delay. Similar to the first
350 * word delay, this is used to make up for the fact that the
351 * crossbar does not make the packet wait. As the delay is
352 * relative, a 32-bit unsigned should be sufficient.
353 */
354 uint32_t lastWordDelay;
355
356 /**
357 * A virtual base opaque structure used to hold state associated
358 * with the packet (e.g., an MSHR), specific to a MemObject that
359 * sees the packet. A pointer to this state is returned in the
360 * packet's response so that the MemObject in question can quickly
361 * look up the state needed to process it. A specific subclass
362 * would be derived from this to carry state specific to a
363 * particular sending device.
364 *
365 * As multiple MemObjects may add their SenderState throughout the
366 * memory system, the SenderStates create a stack, where a
367 * MemObject can add a new Senderstate, as long as the
368 * predecessing SenderState is restored when the response comes
369 * back. For this reason, the predecessor should always be
370 * populated with the current SenderState of a packet before
371 * modifying the senderState field in the request packet.
372 */
373 struct SenderState
374 {
375 SenderState* predecessor;
376 SenderState() : predecessor(NULL) {}
377 virtual ~SenderState() {}
378 };
379
380 /**
381 * Object used to maintain state of a PrintReq. The senderState
382 * field of a PrintReq should always be of this type.
383 */
384 class PrintReqState : public SenderState
385 {
386 private:
387 /**
388 * An entry in the label stack.
389 */
390 struct LabelStackEntry
391 {
392 const std::string label;
393 std::string *prefix;
394 bool labelPrinted;
395 LabelStackEntry(const std::string &_label, std::string *_prefix);
396 };
397
398 typedef std::list<LabelStackEntry> LabelStack;
399 LabelStack labelStack;
400
401 std::string *curPrefixPtr;
402
403 public:
404 std::ostream &os;
405 const int verbosity;
406
407 PrintReqState(std::ostream &os, int verbosity = 0);
408 ~PrintReqState();
409
410 /**
411 * Returns the current line prefix.
412 */
413 const std::string &curPrefix() { return *curPrefixPtr; }
414
415 /**
416 * Push a label onto the label stack, and prepend the given
417 * prefix string onto the current prefix. Labels will only be
418 * printed if an object within the label's scope is printed.
419 */
420 void pushLabel(const std::string &lbl,
421 const std::string &prefix = " ");
422
423 /**
424 * Pop a label off the label stack.
425 */
426 void popLabel();
427
428 /**
429 * Print all of the pending unprinted labels on the
430 * stack. Called by printObj(), so normally not called by
431 * users unless bypassing printObj().
432 */
433 void printLabels();
434
435 /**
436 * Print a Printable object to os, because it matched the
437 * address on a PrintReq.
438 */
439 void printObj(Printable *obj);
440 };
441
442 /**
443 * This packet's sender state. Devices should use dynamic_cast<>
444 * to cast to the state appropriate to the sender. The intent of
445 * this variable is to allow a device to attach extra information
446 * to a request. A response packet must return the sender state
447 * that was attached to the original request (even if a new packet
448 * is created).
449 */
450 SenderState *senderState;
451
452 /**
453 * Push a new sender state to the packet and make the current
454 * sender state the predecessor of the new one. This should be
455 * prefered over direct manipulation of the senderState member
456 * variable.
457 *
458 * @param sender_state SenderState to push at the top of the stack
459 */
460 void pushSenderState(SenderState *sender_state);
461
462 /**
463 * Pop the top of the state stack and return a pointer to it. This
464 * assumes the current sender state is not NULL. This should be
465 * preferred over direct manipulation of the senderState member
466 * variable.
467 *
468 * @return The current top of the stack
469 */
470 SenderState *popSenderState();
471
472 /**
473 * Go through the sender state stack and return the first instance
474 * that is of type T (as determined by a dynamic_cast). If there
475 * is no sender state of type T, NULL is returned.
476 *
477 * @return The topmost state of type T
478 */
479 template <typename T>
480 T * findNextSenderState() const
481 {
482 T *t = NULL;
483 SenderState* sender_state = senderState;
484 while (t == NULL && sender_state != NULL) {
485 t = dynamic_cast<T*>(sender_state);
486 sender_state = sender_state->predecessor;
487 }
488 return t;
489 }
490
491 /// Return the string name of the cmd field (for debugging and
492 /// tracing).
493 const std::string &cmdString() const { return cmd.toString(); }
494
495 /// Return the index of this command.
496 inline int cmdToIndex() const { return cmd.toInt(); }
497
498 bool isRead() const { return cmd.isRead(); }
499 bool isWrite() const { return cmd.isWrite(); }
500 bool isUpgrade() const { return cmd.isUpgrade(); }
501 bool isRequest() const { return cmd.isRequest(); }
502 bool isResponse() const { return cmd.isResponse(); }
503 bool needsExclusive() const { return cmd.needsExclusive(); }
504 bool needsResponse() const { return cmd.needsResponse(); }
505 bool isInvalidate() const { return cmd.isInvalidate(); }
506 bool hasData() const { return cmd.hasData(); }
507 bool isLLSC() const { return cmd.isLLSC(); }
508 bool isError() const { return cmd.isError(); }
509 bool isPrint() const { return cmd.isPrint(); }
510 bool isFlush() const { return cmd.isFlush(); }
511
512 // Snoop flags
513 void assertMemInhibit()
514 {
515 assert(isRequest());
516 assert(!flags.isSet(MEM_INHIBIT));
517 flags.set(MEM_INHIBIT);
518 }
519 bool memInhibitAsserted() const { return flags.isSet(MEM_INHIBIT); }
520 void assertShared() { flags.set(SHARED); }
521 bool sharedAsserted() const { return flags.isSet(SHARED); }
522
523 // Special control flags
524 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); }
525 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); }
526 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); }
527 void clearSupplyExclusive() { flags.clear(SUPPLY_EXCLUSIVE); }
528 bool isSupplyExclusive() const { return flags.isSet(SUPPLY_EXCLUSIVE); }
529 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); }
530 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); }
531 void setPrefetchSquashed() { flags.set(PREFETCH_SNOOP_SQUASH); }
532 bool prefetchSquashed() const { return flags.isSet(PREFETCH_SNOOP_SQUASH); }
533
534 // Network error conditions... encapsulate them as methods since
535 // their encoding keeps changing (from result field to command
536 // field, etc.)
537 void
538 setBadAddress()
539 {
540 assert(isResponse());
541 cmd = MemCmd::BadAddressError;
542 }
543
544 bool hadBadAddress() const { return cmd == MemCmd::BadAddressError; }
545 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
546
547 /// Accessor function to get the source index of the packet.
548 PortID getSrc() const { return src; }
549 /// Accessor function to set the source index of the packet.
550 void setSrc(PortID _src) { src = _src; }
551
552 /// Accessor function for the destination index of the packet.
553 PortID getDest() const { return dest; }
554 /// Accessor function to set the destination index of the packet.
555 void setDest(PortID _dest) { dest = _dest; }
556 /// Reset destination field, e.g. to turn a response into a request again.
557 void clearDest() { dest = InvalidPortID; }
558
559 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
560 /**
561 * Update the address of this packet mid-transaction. This is used
562 * by the address mapper to change an already set address to a new
563 * one based on the system configuration. It is intended to remap
564 * an existing address, so it asserts that the current address is
565 * valid.
566 */
567 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; }
568
569 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; }
570 Addr getOffset(int blkSize) const { return getAddr() & (Addr)(blkSize - 1); }
571
572 bool isSecure() const
573 {
574 assert(flags.isSet(VALID_ADDR));
575 return _isSecure;
576 }
577
578 /**
579 * It has been determined that the SC packet should successfully update
580 * memory. Therefore, convert this SC packet to a normal write.
581 */
582 void
583 convertScToWrite()
584 {
585 assert(isLLSC());
586 assert(isWrite());
587 cmd = MemCmd::WriteReq;
588 }
589
590 /**
591 * When ruby is in use, Ruby will monitor the cache line and thus M5
592 * phys memory should treat LL ops as normal reads.
593 */
594 void
595 convertLlToRead()
596 {
597 assert(isLLSC());
598 assert(isRead());
599 cmd = MemCmd::ReadReq;
600 }
601
602 /**
603 * Constructor. Note that a Request object must be constructed
604 * first, but the Requests's physical address and size fields need
605 * not be valid. The command must be supplied.
606 */
607 Packet(const RequestPtr _req, MemCmd _cmd)
608 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false),
609 size(0), src(InvalidPortID), dest(InvalidPortID),
610 bytesValidStart(0), bytesValidEnd(0),
611 firstWordDelay(0), lastWordDelay(0),
612 senderState(NULL)
613 {
614 if (req->hasPaddr()) {
615 addr = req->getPaddr();
616 flags.set(VALID_ADDR);
617 _isSecure = req->isSecure();
618 }
619 if (req->hasSize()) {
620 size = req->getSize();
621 flags.set(VALID_SIZE);
622 }
623 }
624
625 /**
626 * Alternate constructor if you are trying to create a packet with
627 * a request that is for a whole block, not the address from the
628 * req. this allows for overriding the size/addr of the req.
629 */
630 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize)
631 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false),
632 src(InvalidPortID), dest(InvalidPortID),
633 bytesValidStart(0), bytesValidEnd(0),
634 firstWordDelay(0), lastWordDelay(0),
635 senderState(NULL)
636 {
637 if (req->hasPaddr()) {
638 addr = req->getPaddr() & ~(_blkSize - 1);
639 flags.set(VALID_ADDR);
640 _isSecure = req->isSecure();
641 }
642 size = _blkSize;
643 flags.set(VALID_SIZE);
644 }
645
646 /**
647 * Alternate constructor for copying a packet. Copy all fields
648 * *except* if the original packet's data was dynamic, don't copy
649 * that, as we can't guarantee that the new packet's lifetime is
650 * less than that of the original packet. In this case the new
651 * packet should allocate its own data.
652 */
653 Packet(PacketPtr pkt, bool clear_flags, bool alloc_data)
654 : cmd(pkt->cmd), req(pkt->req),
655 data(nullptr),
656 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size),
657 src(pkt->src), dest(pkt->dest),
658 bytesValidStart(pkt->bytesValidStart),
659 bytesValidEnd(pkt->bytesValidEnd),
660 firstWordDelay(pkt->firstWordDelay),
661 lastWordDelay(pkt->lastWordDelay),
662 senderState(pkt->senderState)
663 {
664 if (!clear_flags)
665 flags.set(pkt->flags & COPY_FLAGS);
666
667 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE));
668
669 // should we allocate space for data, or not, the express
670 // snoops do not need to carry any data as they only serve to
671 // co-ordinate state changes
672 if (alloc_data) {
673 // even if asked to allocate data, if the original packet
674 // holds static data, then the sender will not be doing
675 // any memcpy on receiving the response, thus we simply
676 // carry the pointer forward
677 if (pkt->flags.isSet(STATIC_DATA)) {
678 data = pkt->data;
679 flags.set(STATIC_DATA);
680 } else {
681 allocate();
682 }
683 }
684 }
685
686 /**
687 * Change the packet type based on request type.
688 */
689 void
690 refineCommand()
691 {
692 if (cmd == MemCmd::ReadReq) {
693 if (req->isLLSC()) {
694 cmd = MemCmd::LoadLockedReq;
695 } else if (req->isPrefetch()) {
696 cmd = MemCmd::SoftPFReq;
697 }
698 } else if (cmd == MemCmd::WriteReq) {
699 if (req->isLLSC()) {
700 cmd = MemCmd::StoreCondReq;
701 } else if (req->isSwap()) {
702 cmd = MemCmd::SwapReq;
703 }
704 }
705 }
706
707 /**
708 * Constructor-like methods that return Packets based on Request objects.
709 * Will call refineCommand() to fine-tune the Packet type if it's not a
710 * vanilla read or write.
711 */
712 static PacketPtr
713 createRead(const RequestPtr req)
714 {
715 PacketPtr pkt = new Packet(req, MemCmd::ReadReq);
716 pkt->refineCommand();
717 return pkt;
718 }
719
720 static PacketPtr
721 createWrite(const RequestPtr req)
722 {
723 PacketPtr pkt = new Packet(req, MemCmd::WriteReq);
724 pkt->refineCommand();
725 return pkt;
726 }
727
728 /**
729 * clean up packet variables
730 */
731 ~Packet()
732 {
733 // If this is a request packet for which there's no response,
734 // delete the request object here, since the requester will
735 // never get the chance.
736 if (req && isRequest() && !needsResponse())
737 delete req;
738 deleteData();
739 }
740
741 /**
742 * Take a request packet and modify it in place to be suitable for
743 * returning as a response to that request. The source field is
744 * turned into the destination, and subsequently cleared. Note
745 * that the latter is not necessary for atomic requests, but
746 * causes no harm as neither field is valid.
747 */
748 void
749 makeResponse()
750 {
751 assert(needsResponse());
752 assert(isRequest());
753 origCmd = cmd;
754 cmd = cmd.responseCommand();
755
756 // responses are never express, even if the snoop that
757 // triggered them was
758 flags.clear(EXPRESS_SNOOP);
759
760 dest = src;
761 src = InvalidPortID;
762 }
763
764 void
765 makeAtomicResponse()
766 {
767 makeResponse();
768 }
769
770 void
771 makeTimingResponse()
772 {
773 makeResponse();
774 }
775
776 void
777 setFunctionalResponseStatus(bool success)
778 {
779 if (!success) {
780 if (isWrite()) {
781 cmd = MemCmd::FunctionalWriteError;
782 } else {
783 cmd = MemCmd::FunctionalReadError;
784 }
785 }
786 }
787
788 void
789 setSize(unsigned size)
790 {
791 assert(!flags.isSet(VALID_SIZE));
792
793 this->size = size;
794 flags.set(VALID_SIZE);
795 }
796
797
798 /**
799 * Set the data pointer to the following value that should not be
800 * freed. Static data allows us to do a single memcpy even if
801 * multiple packets are required to get from source to destination
802 * and back. In essence the pointer is set calling dataStatic on
803 * the original packet, and whenever this packet is copied and
804 * forwarded the same pointer is passed on. When a packet
805 * eventually reaches the destination holding the data, it is
806 * copied once into the location originally set. On the way back
807 * to the source, no copies are necessary.
808 */
809 template <typename T>
810 void
811 dataStatic(T *p)
812 {
813 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
814 data = (PacketDataPtr)p;
815 flags.set(STATIC_DATA);
816 }
817
818 /**
819 * Set the data pointer to the following value that should not be
820 * freed. This version of the function allows the pointer passed
821 * to us to be const. To avoid issues down the line we cast the
822 * constness away, the alternative would be to keep both a const
823 * and non-const data pointer and cleverly choose between
824 * them. Note that this is only allowed for static data.
825 */
826 template <typename T>
827 void
828 dataStaticConst(const T *p)
829 {
830 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
831 data = const_cast<PacketDataPtr>(p);
832 flags.set(STATIC_DATA);
833 }
834
835 /**
836 * Set the data pointer to a value that should have delete []
837 * called on it. Dynamic data is local to this packet, and as the
838 * packet travels from source to destination, forwarded packets
839 * will allocate their own data. When a packet reaches the final
840 * destination it will populate the dynamic data of that specific
841 * packet, and on the way back towards the source, memcpy will be
842 * invoked in every step where a new packet was created e.g. in
843 * the caches. Ultimately when the response reaches the source a
844 * final memcpy is needed to extract the data from the packet
845 * before it is deallocated.
846 */
847 template <typename T>
848 void
849 dataDynamic(T *p)
850 {
851 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
852 data = (PacketDataPtr)p;
853 flags.set(DYNAMIC_DATA);
854 }
855
856 /**
857 * get a pointer to the data ptr.
858 */
859 template <typename T>
860 T*
861 getPtr()
862 {
863 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
864 return (T*)data;
865 }
866
867 template <typename T>
868 const T*
869 getConstPtr() const
870 {
871 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
872 return (const T*)data;
873 }
874
875 /**
876 * return the value of what is pointed to in the packet.
877 */
878 template <typename T>
879 T get() const;
880
881 /**
882 * set the value in the data pointer to v.
883 */
884 template <typename T>
885 void set(T v);
886
887 /**
888 * Copy data into the packet from the provided pointer.
889 */
890 void
891 setData(const uint8_t *p)
892 {
893 // we should never be copying data onto itself, which means we
894 // must idenfity packets with static data, as they carry the
895 // same pointer from source to destination and back
896 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA));
897
898 if (p != getPtr<uint8_t>())
899 // for packet with allocated dynamic data, we copy data from
900 // one to the other, e.g. a forwarded response to a response
901 std::memcpy(getPtr<uint8_t>(), p, getSize());
902 }
903
904 /**
905 * Copy data into the packet from the provided block pointer,
906 * which is aligned to the given block size.
907 */
908 void
909 setDataFromBlock(const uint8_t *blk_data, int blkSize)
910 {
911 setData(blk_data + getOffset(blkSize));
912 }
913
914 /**
915 * Copy data from the packet to the provided block pointer, which
916 * is aligned to the given block size.
917 */
918 void
919 writeData(uint8_t *p) const
920 {
921 std::memcpy(p, getConstPtr<uint8_t>(), getSize());
922 }
923
924 /**
925 * Copy data from the packet to the memory at the provided pointer.
926 */
927 void
928 writeDataToBlock(uint8_t *blk_data, int blkSize) const
929 {
930 writeData(blk_data + getOffset(blkSize));
931 }
932
933 /**
934 * delete the data pointed to in the data pointer. Ok to call to
935 * matter how data was allocted.
936 */
937 void
938 deleteData()
939 {
940 if (flags.isSet(DYNAMIC_DATA))
941 delete [] data;
942
943 flags.clear(STATIC_DATA|DYNAMIC_DATA);
944 data = NULL;
945 }
946
947 /** Allocate memory for the packet. */
948 void
949 allocate()
950 {
951 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
952 flags.set(DYNAMIC_DATA);
953 data = new uint8_t[getSize()];
954 }
955
956 /**
957 * Check a functional request against a memory value stored in
958 * another packet (i.e. an in-transit request or
959 * response). Returns true if the current packet is a read, and
960 * the other packet provides the data, which is then copied to the
961 * current packet. If the current packet is a write, and the other
962 * packet intersects this one, then we update the data
963 * accordingly.
964 */
965 bool
966 checkFunctional(PacketPtr other)
967 {
968 // all packets that are carrying a payload should have a valid
969 // data pointer
970 return checkFunctional(other, other->getAddr(), other->isSecure(),
971 other->getSize(),
972 other->hasData() ?
973 other->getPtr<uint8_t>() : NULL);
974 }
975
976 /**
977 * Check a functional request against a memory value represented
978 * by a base/size pair and an associated data array. If the
979 * current packet is a read, it may be satisfied by the memory
980 * value. If the current packet is a write, it may update the
981 * memory value.
982 */
983 bool
984 checkFunctional(Printable *obj, Addr base, bool is_secure, int size,
985 uint8_t *_data);
986
987 /**
988 * Push label for PrintReq (safe to call unconditionally).
989 */
990 void
991 pushLabel(const std::string &lbl)
992 {
993 if (isPrint())
994 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
995 }
996
997 /**
998 * Pop label for PrintReq (safe to call unconditionally).
999 */
1000 void
1001 popLabel()
1002 {
1003 if (isPrint())
1004 safe_cast<PrintReqState*>(senderState)->popLabel();
1005 }
1006
1007 void print(std::ostream &o, int verbosity = 0,
1008 const std::string &prefix = "") const;
1009
1010 /**
1011 * A no-args wrapper of print(std::ostream...)
1012 * meant to be invoked from DPRINTFs
1013 * avoiding string overheads in fast mode
1014 * @return string with the request's type and start<->end addresses
1015 */
1016 std::string print() const;
1017};
1018
1019#endif //__MEM_PACKET_HH