1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
|
/*
* Copyright (c) 2006 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Ron Dreslinski
* Steve Reinhardt
* Ali Saidi
*/
/**
* @file
* Declaration of the Packet class.
*/
#ifndef __MEM_PACKET_HH__
#define __MEM_PACKET_HH__
#include <cassert>
#include <list>
#include <bitset>
#include "base/compiler.hh"
#include "base/fast_alloc.hh"
#include "base/misc.hh"
#include "base/printable.hh"
#include "mem/request.hh"
#include "sim/host.hh"
#include "sim/core.hh"
struct Packet;
typedef Packet *PacketPtr;
typedef uint8_t* PacketDataPtr;
typedef std::list<PacketPtr> PacketList;
class MemCmd
{
public:
/** List of all commands associated with a packet. */
enum Command
{
InvalidCmd,
ReadReq,
ReadResp,
ReadRespWithInvalidate,
WriteReq,
WriteResp,
Writeback,
SoftPFReq,
HardPFReq,
SoftPFResp,
HardPFResp,
WriteInvalidateReq,
WriteInvalidateResp,
UpgradeReq,
UpgradeResp,
ReadExReq,
ReadExResp,
LoadLockedReq,
LoadLockedResp,
StoreCondReq,
StoreCondResp,
SwapReq,
SwapResp,
// Error responses
// @TODO these should be classified as responses rather than
// requests; coding them as requests initially for backwards
// compatibility
NetworkNackError, // nacked at network layer (not by protocol)
InvalidDestError, // packet dest field invalid
BadAddressError, // memory address invalid
// Fake simulator-only commands
PrintReq, // Print state matching address
NUM_MEM_CMDS
};
private:
/** List of command attributes. */
enum Attribute
{
IsRead, //!< Data flows from responder to requester
IsWrite, //!< Data flows from requester to responder
IsPrefetch, //!< Not a demand access
IsInvalidate,
NeedsExclusive, //!< Requires exclusive copy to complete in-cache
IsRequest, //!< Issued by requester
IsResponse, //!< Issue by responder
NeedsResponse, //!< Requester needs response from target
IsSWPrefetch,
IsHWPrefetch,
IsLocked, //!< Alpha/MIPS LL or SC access
HasData, //!< There is an associated payload
IsError, //!< Error response
IsPrint, //!< Print state matching address (for debugging)
NUM_COMMAND_ATTRIBUTES
};
/** Structure that defines attributes and other data associated
* with a Command. */
struct CommandInfo {
/** Set of attribute flags. */
const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
/** Corresponding response for requests; InvalidCmd if no
* response is applicable. */
const Command response;
/** String representation (for printing) */
const std::string str;
};
/** Array to map Command enum to associated info. */
static const CommandInfo commandInfo[];
private:
Command cmd;
bool testCmdAttrib(MemCmd::Attribute attrib) const {
return commandInfo[cmd].attributes[attrib] != 0;
}
public:
bool isRead() const { return testCmdAttrib(IsRead); }
bool isWrite() const { return testCmdAttrib(IsWrite); }
bool isRequest() const { return testCmdAttrib(IsRequest); }
bool isResponse() const { return testCmdAttrib(IsResponse); }
bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); }
bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
bool hasData() const { return testCmdAttrib(HasData); }
bool isReadWrite() const { return isRead() && isWrite(); }
bool isLocked() const { return testCmdAttrib(IsLocked); }
bool isError() const { return testCmdAttrib(IsError); }
bool isPrint() const { return testCmdAttrib(IsPrint); }
const Command responseCommand() const {
return commandInfo[cmd].response;
}
/** Return the string to a cmd given by idx. */
const std::string &toString() const {
return commandInfo[cmd].str;
}
int toInt() const { return (int)cmd; }
MemCmd(Command _cmd)
: cmd(_cmd)
{ }
MemCmd(int _cmd)
: cmd((Command)_cmd)
{ }
MemCmd()
: cmd(InvalidCmd)
{ }
bool operator==(MemCmd c2) { return (cmd == c2.cmd); }
bool operator!=(MemCmd c2) { return (cmd != c2.cmd); }
friend class Packet;
};
/**
* A Packet is used to encapsulate a transfer between two objects in
* the memory system (e.g., the L1 and L2 cache). (In contrast, a
* single Request travels all the way from the requester to the
* ultimate destination and back, possibly being conveyed by several
* different Packets along the way.)
*/
class Packet : public FastAlloc, public Printable
{
public:
typedef MemCmd::Command Command;
/** The command field of the packet. */
MemCmd cmd;
/** A pointer to the original request. */
RequestPtr req;
private:
/** A pointer to the data being transfered. It can be differnt
* sizes at each level of the heirarchy so it belongs in the
* packet, not request. This may or may not be populated when a
* responder recieves the packet. If not populated it memory
* should be allocated.
*/
PacketDataPtr data;
/** Is the data pointer set to a value that shouldn't be freed
* when the packet is destroyed? */
bool staticData;
/** The data pointer points to a value that should be freed when
* the packet is destroyed. */
bool dynamicData;
/** the data pointer points to an array (thus delete [] ) needs to
* be called on it rather than simply delete.*/
bool arrayData;
/** The address of the request. This address could be virtual or
* physical, depending on the system configuration. */
Addr addr;
/** The size of the request or transfer. */
int size;
/** Device address (e.g., bus ID) of the source of the
* transaction. The source is not responsible for setting this
* field; it is set implicitly by the interconnect when the
* packet is first sent. */
short src;
/** Device address (e.g., bus ID) of the destination of the
* transaction. The special value Broadcast indicates that the
* packet should be routed based on its address. This field is
* initialized in the constructor and is thus always valid
* (unlike * addr, size, and src). */
short dest;
/** The original value of the command field. Only valid when the
* current command field is an error condition; in that case, the
* previous contents of the command field are copied here. This
* field is *not* set on non-error responses.
*/
MemCmd origCmd;
/** Are the 'addr' and 'size' fields valid? */
bool addrSizeValid;
/** Is the 'src' field valid? */
bool srcValid;
bool destValid;
enum Flag {
// Snoop response flags
MemInhibit,
Shared,
// Special control flags
/// Special timing-mode atomic snoop for multi-level coherence.
ExpressSnoop,
/// Does supplier have exclusive copy?
/// Useful for multi-level coherence.
SupplyExclusive,
NUM_PACKET_FLAGS
};
/** Status flags */
std::bitset<NUM_PACKET_FLAGS> flags;
public:
/** Used to calculate latencies for each packet.*/
Tick time;
/** The time at which the packet will be fully transmitted */
Tick finishTime;
/** The time at which the first chunk of the packet will be transmitted */
Tick firstWordTime;
/** The special destination address indicating that the packet
* should be routed based on its address. */
static const short Broadcast = -1;
/** A virtual base opaque structure used to hold state associated
* with the packet but specific to the sending device (e.g., an
* MSHR). A pointer to this state is returned in the packet's
* response so that the sender can quickly look up the state
* needed to process it. A specific subclass would be derived
* from this to carry state specific to a particular sending
* device. */
class SenderState {
public:
virtual ~SenderState() {}
};
/**
* Object used to maintain state of a PrintReq. The senderState
* field of a PrintReq should always be of this type.
*/
class PrintReqState : public SenderState, public FastAlloc {
/** An entry in the label stack. */
class LabelStackEntry {
public:
const std::string label;
std::string *prefix;
bool labelPrinted;
LabelStackEntry(const std::string &_label,
std::string *_prefix);
};
typedef std::list<LabelStackEntry> LabelStack;
LabelStack labelStack;
std::string *curPrefixPtr;
public:
std::ostream &os;
const int verbosity;
PrintReqState(std::ostream &os, int verbosity = 0);
~PrintReqState();
/** Returns the current line prefix. */
const std::string &curPrefix() { return *curPrefixPtr; }
/** Push a label onto the label stack, and prepend the given
* prefix string onto the current prefix. Labels will only be
* printed if an object within the label's scope is
* printed. */
void pushLabel(const std::string &lbl,
const std::string &prefix = " ");
/** Pop a label off the label stack. */
void popLabel();
/** Print all of the pending unprinted labels on the
* stack. Called by printObj(), so normally not called by
* users unless bypassing printObj(). */
void printLabels();
/** Print a Printable object to os, because it matched the
* address on a PrintReq. */
void printObj(Printable *obj);
};
/** This packet's sender state. Devices should use dynamic_cast<>
* to cast to the state appropriate to the sender. */
SenderState *senderState;
/** Return the string name of the cmd field (for debugging and
* tracing). */
const std::string &cmdString() const { return cmd.toString(); }
/** Return the index of this command. */
inline int cmdToIndex() const { return cmd.toInt(); }
bool isRead() const { return cmd.isRead(); }
bool isWrite() const { return cmd.isWrite(); }
bool isRequest() const { return cmd.isRequest(); }
bool isResponse() const { return cmd.isResponse(); }
bool needsExclusive() const { return cmd.needsExclusive(); }
bool needsResponse() const { return cmd.needsResponse(); }
bool isInvalidate() const { return cmd.isInvalidate(); }
bool hasData() const { return cmd.hasData(); }
bool isReadWrite() const { return cmd.isReadWrite(); }
bool isLocked() const { return cmd.isLocked(); }
bool isError() const { return cmd.isError(); }
bool isPrint() const { return cmd.isPrint(); }
// Snoop flags
void assertMemInhibit() { flags[MemInhibit] = true; }
bool memInhibitAsserted() { return flags[MemInhibit]; }
void assertShared() { flags[Shared] = true; }
bool sharedAsserted() { return flags[Shared]; }
// Special control flags
void setExpressSnoop() { flags[ExpressSnoop] = true; }
bool isExpressSnoop() { return flags[ExpressSnoop]; }
void setSupplyExclusive() { flags[SupplyExclusive] = true; }
bool isSupplyExclusive() { return flags[SupplyExclusive]; }
// Network error conditions... encapsulate them as methods since
// their encoding keeps changing (from result field to command
// field, etc.)
void setNacked() { assert(isResponse()); cmd = MemCmd::NetworkNackError; }
void setBadAddress() { assert(isResponse()); cmd = MemCmd::BadAddressError; }
bool wasNacked() { return cmd == MemCmd::NetworkNackError; }
bool hadBadAddress() { return cmd == MemCmd::BadAddressError; }
void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN }
/** Accessor function that returns the source index of the packet. */
short getSrc() const { assert(srcValid); return src; }
void setSrc(short _src) { src = _src; srcValid = true; }
/** Reset source field, e.g. to retransmit packet on different bus. */
void clearSrc() { srcValid = false; }
/** Accessor function that returns the destination index of
the packet. */
short getDest() const { assert(destValid); return dest; }
void setDest(short _dest) { dest = _dest; destValid = true; }
Addr getAddr() const { assert(addrSizeValid); return addr; }
int getSize() const { assert(addrSizeValid); return size; }
Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); }
/** Constructor. Note that a Request object must be constructed
* first, but the Requests's physical address and size fields
* need not be valid. The command and destination addresses
* must be supplied. */
Packet(Request *_req, MemCmd _cmd, short _dest)
: cmd(_cmd), req(_req),
data(NULL), staticData(false), dynamicData(false), arrayData(false),
addr(_req->paddr), size(_req->size), dest(_dest),
addrSizeValid(_req->validPaddr), srcValid(false), destValid(true),
flags(0), time(curTick), senderState(NULL)
{
}
/** Alternate constructor if you are trying to create a packet with
* a request that is for a whole block, not the address from the req.
* this allows for overriding the size/addr of the req.*/
Packet(Request *_req, MemCmd _cmd, short _dest, int _blkSize)
: cmd(_cmd), req(_req),
data(NULL), staticData(false), dynamicData(false), arrayData(false),
addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), dest(_dest),
addrSizeValid(_req->validPaddr), srcValid(false), destValid(true),
flags(0), time(curTick), senderState(NULL)
{
}
/** Alternate constructor for copying a packet. Copy all fields
* *except* if the original packet's data was dynamic, don't copy
* that, as we can't guarantee that the new packet's lifetime is
* less than that of the original packet. In this case the new
* packet should allocate its own data. */
Packet(Packet *origPkt, bool clearFlags = false)
: cmd(origPkt->cmd), req(origPkt->req),
data(origPkt->staticData ? origPkt->data : NULL),
staticData(origPkt->staticData),
dynamicData(false), arrayData(false),
addr(origPkt->addr), size(origPkt->size),
src(origPkt->src), dest(origPkt->dest),
addrSizeValid(origPkt->addrSizeValid),
srcValid(origPkt->srcValid), destValid(origPkt->destValid),
flags(clearFlags ? 0 : origPkt->flags),
time(curTick), senderState(origPkt->senderState)
{
}
/** Destructor. */
~Packet()
{ if (staticData || dynamicData) deleteData(); }
/** Reinitialize packet address and size from the associated
* Request object, and reset other fields that may have been
* modified by a previous transaction. Typically called when a
* statically allocated Request/Packet pair is reused for
* multiple transactions. */
void reinitFromRequest() {
assert(req->validPaddr);
flags = 0;
addr = req->paddr;
size = req->size;
time = req->time;
addrSizeValid = true;
if (dynamicData) {
deleteData();
dynamicData = false;
arrayData = false;
}
}
/**
* Take a request packet and modify it in place to be suitable for
* returning as a response to that request. The source and
* destination fields are *not* modified, as is appropriate for
* atomic accesses.
*/
void makeResponse()
{
assert(needsResponse());
assert(isRequest());
origCmd = cmd;
cmd = cmd.responseCommand();
dest = src;
destValid = srcValid;
srcValid = false;
}
void makeAtomicResponse()
{
makeResponse();
}
void makeTimingResponse()
{
makeResponse();
}
/**
* Take a request packet that has been returned as NACKED and
* modify it so that it can be sent out again. Only packets that
* need a response can be NACKED, so verify that that is true.
*/
void
reinitNacked()
{
assert(wasNacked());
cmd = origCmd;
assert(needsResponse());
setDest(Broadcast);
}
/**
* Set the data pointer to the following value that should not be
* freed.
*/
template <typename T>
void
dataStatic(T *p)
{
if(dynamicData)
dynamicData = false;
data = (PacketDataPtr)p;
staticData = true;
}
/**
* Set the data pointer to a value that should have delete []
* called on it.
*/
template <typename T>
void
dataDynamicArray(T *p)
{
assert(!staticData && !dynamicData);
data = (PacketDataPtr)p;
dynamicData = true;
arrayData = true;
}
/**
* set the data pointer to a value that should have delete called
* on it.
*/
template <typename T>
void
dataDynamic(T *p)
{
assert(!staticData && !dynamicData);
data = (PacketDataPtr)p;
dynamicData = true;
arrayData = false;
}
/** get a pointer to the data ptr. */
template <typename T>
T*
getPtr()
{
assert(staticData || dynamicData);
return (T*)data;
}
/** return the value of what is pointed to in the packet. */
template <typename T>
T get();
/** set the value in the data pointer to v. */
template <typename T>
void set(T v);
/**
* Copy data into the packet from the provided pointer.
*/
void setData(uint8_t *p)
{
std::memcpy(getPtr<uint8_t>(), p, getSize());
}
/**
* Copy data into the packet from the provided block pointer,
* which is aligned to the given block size.
*/
void setDataFromBlock(uint8_t *blk_data, int blkSize)
{
setData(blk_data + getOffset(blkSize));
}
/**
* Copy data from the packet to the provided block pointer, which
* is aligned to the given block size.
*/
void writeData(uint8_t *p)
{
std::memcpy(p, getPtr<uint8_t>(), getSize());
}
/**
* Copy data from the packet to the memory at the provided pointer.
*/
void writeDataToBlock(uint8_t *blk_data, int blkSize)
{
writeData(blk_data + getOffset(blkSize));
}
/**
* delete the data pointed to in the data pointer. Ok to call to
* matter how data was allocted.
*/
void deleteData();
/** If there isn't data in the packet, allocate some. */
void allocate();
/**
* Check a functional request against a memory value represented
* by a base/size pair and an associated data array. If the
* functional request is a read, it may be satisfied by the memory
* value. If the functional request is a write, it may update the
* memory value.
*/
bool checkFunctional(Printable *obj, Addr base, int size, uint8_t *data);
/**
* Check a functional request against a memory value stored in
* another packet (i.e. an in-transit request or response).
*/
bool checkFunctional(PacketPtr otherPkt) {
return checkFunctional(otherPkt,
otherPkt->getAddr(), otherPkt->getSize(),
otherPkt->hasData() ?
otherPkt->getPtr<uint8_t>() : NULL);
}
/**
* Push label for PrintReq (safe to call unconditionally).
*/
void pushLabel(const std::string &lbl) {
if (isPrint()) {
dynamic_cast<PrintReqState*>(senderState)->pushLabel(lbl);
}
}
/**
* Pop label for PrintReq (safe to call unconditionally).
*/
void popLabel() {
if (isPrint()) {
dynamic_cast<PrintReqState*>(senderState)->popLabel();
}
}
void print(std::ostream &o, int verbosity = 0,
const std::string &prefix = "") const;
};
#endif //__MEM_PACKET_HH
|