1/*
2 * Copyright (c) 1999-2012 Mark D. Hill and David A. Wood
3 * Copyright (c) 2013 Advanced Micro Devices, Inc.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include "mem/ruby/structures/CacheMemory.hh"
31
32#include "base/intmath.hh"
|
34#include "debug/RubyCache.hh"
35#include "debug/RubyCacheTrace.hh"
36#include "debug/RubyResourceStalls.hh"
37#include "debug/RubyStats.hh"
38#include "mem/protocol/AccessPermission.hh"
39#include "mem/ruby/system/RubySystem.hh"
40#include "mem/ruby/system/WeightedLRUPolicy.hh"
41
42using namespace std;
43
44ostream&
45operator<<(ostream& out, const CacheMemory& obj)
46{
47 obj.print(out);
48 out << flush;
49 return out;
50}
51
52CacheMemory *
53RubyCacheParams::create()
54{
55 return new CacheMemory(this);
56}
57
58CacheMemory::CacheMemory(const Params *p)
59 : SimObject(p),
60 dataArray(p->dataArrayBanks, p->dataAccessLatency,
61 p->start_index_bit, p->ruby_system),
62 tagArray(p->tagArrayBanks, p->tagAccessLatency,
63 p->start_index_bit, p->ruby_system)
64{
65 m_cache_size = p->size;
66 m_cache_assoc = p->assoc;
67 m_replacementPolicy_ptr = p->replacement_policy;
68 m_replacementPolicy_ptr->setCache(this);
69 m_start_index_bit = p->start_index_bit;
70 m_is_instruction_only_cache = p->is_icache;
71 m_resource_stalls = p->resourceStalls;
72 m_block_size = p->block_size; // may be 0 at this point. Updated in init()
73}
74
75void
76CacheMemory::init()
77{
78 if (m_block_size == 0) {
79 m_block_size = RubySystem::getBlockSizeBytes();
80 }
81 m_cache_num_sets = (m_cache_size / m_cache_assoc) / m_block_size;
82 assert(m_cache_num_sets > 1);
83 m_cache_num_set_bits = floorLog2(m_cache_num_sets);
84 assert(m_cache_num_set_bits > 0);
85
86 m_cache.resize(m_cache_num_sets,
87 std::vector<AbstractCacheEntry*>(m_cache_assoc, nullptr));
88}
89
90CacheMemory::~CacheMemory()
91{
92 if (m_replacementPolicy_ptr)
93 delete m_replacementPolicy_ptr;
94 for (int i = 0; i < m_cache_num_sets; i++) {
95 for (int j = 0; j < m_cache_assoc; j++) {
96 delete m_cache[i][j];
97 }
98 }
99}
100
101// convert a Address to its location in the cache
102int64_t
103CacheMemory::addressToCacheSet(Addr address) const
104{
105 assert(address == makeLineAddress(address));
106 return bitSelect(address, m_start_index_bit,
107 m_start_index_bit + m_cache_num_set_bits - 1);
108}
109
110// Given a cache index: returns the index of the tag in a set.
111// returns -1 if the tag is not found.
112int
113CacheMemory::findTagInSet(int64_t cacheSet, Addr tag) const
114{
115 assert(tag == makeLineAddress(tag));
116 // search the set for the tags
117 auto it = m_tag_index.find(tag);
118 if (it != m_tag_index.end())
119 if (m_cache[cacheSet][it->second]->m_Permission !=
120 AccessPermission_NotPresent)
121 return it->second;
122 return -1; // Not found
123}
124
125// Given a cache index: returns the index of the tag in a set.
126// returns -1 if the tag is not found.
127int
128CacheMemory::findTagInSetIgnorePermissions(int64_t cacheSet,
129 Addr tag) const
130{
131 assert(tag == makeLineAddress(tag));
132 // search the set for the tags
133 auto it = m_tag_index.find(tag);
134 if (it != m_tag_index.end())
135 return it->second;
136 return -1; // Not found
137}
138
139// Given an unique cache block identifier (idx): return the valid address
140// stored by the cache block. If the block is invalid/notpresent, the
141// function returns the 0 address
142Addr
143CacheMemory::getAddressAtIdx(int idx) const
144{
145 Addr tmp(0);
146
147 int set = idx / m_cache_assoc;
148 assert(set < m_cache_num_sets);
149
150 int way = idx - set * m_cache_assoc;
151 assert (way < m_cache_assoc);
152
153 AbstractCacheEntry* entry = m_cache[set][way];
154 if (entry == NULL ||
155 entry->m_Permission == AccessPermission_Invalid ||
156 entry->m_Permission == AccessPermission_NotPresent) {
157 return tmp;
158 }
159 return entry->m_Address;
160}
161
162bool
163CacheMemory::tryCacheAccess(Addr address, RubyRequestType type,
164 DataBlock*& data_ptr)
165{
166 assert(address == makeLineAddress(address));
167 DPRINTF(RubyCache, "address: %#x\n", address);
168 int64_t cacheSet = addressToCacheSet(address);
169 int loc = findTagInSet(cacheSet, address);
170 if (loc != -1) {
171 // Do we even have a tag match?
172 AbstractCacheEntry* entry = m_cache[cacheSet][loc];
173 m_replacementPolicy_ptr->touch(cacheSet, loc, curTick());
174 data_ptr = &(entry->getDataBlk());
175
176 if (entry->m_Permission == AccessPermission_Read_Write) {
177 return true;
178 }
179 if ((entry->m_Permission == AccessPermission_Read_Only) &&
180 (type == RubyRequestType_LD || type == RubyRequestType_IFETCH)) {
181 return true;
182 }
183 // The line must not be accessible
184 }
185 data_ptr = NULL;
186 return false;
187}
188
189bool
190CacheMemory::testCacheAccess(Addr address, RubyRequestType type,
191 DataBlock*& data_ptr)
192{
193 assert(address == makeLineAddress(address));
194 DPRINTF(RubyCache, "address: %#x\n", address);
195 int64_t cacheSet = addressToCacheSet(address);
196 int loc = findTagInSet(cacheSet, address);
197
198 if (loc != -1) {
199 // Do we even have a tag match?
200 AbstractCacheEntry* entry = m_cache[cacheSet][loc];
201 m_replacementPolicy_ptr->touch(cacheSet, loc, curTick());
202 data_ptr = &(entry->getDataBlk());
203
204 return m_cache[cacheSet][loc]->m_Permission !=
205 AccessPermission_NotPresent;
206 }
207
208 data_ptr = NULL;
209 return false;
210}
211
212// tests to see if an address is present in the cache
213bool
214CacheMemory::isTagPresent(Addr address) const
215{
216 assert(address == makeLineAddress(address));
217 int64_t cacheSet = addressToCacheSet(address);
218 int loc = findTagInSet(cacheSet, address);
219
220 if (loc == -1) {
221 // We didn't find the tag
222 DPRINTF(RubyCache, "No tag match for address: %#x\n", address);
223 return false;
224 }
225 DPRINTF(RubyCache, "address: %#x found\n", address);
226 return true;
227}
228
229// Returns true if there is:
230// a) a tag match on this address or there is
231// b) an unused line in the same cache "way"
232bool
233CacheMemory::cacheAvail(Addr address) const
234{
235 assert(address == makeLineAddress(address));
236
237 int64_t cacheSet = addressToCacheSet(address);
238
239 for (int i = 0; i < m_cache_assoc; i++) {
240 AbstractCacheEntry* entry = m_cache[cacheSet][i];
241 if (entry != NULL) {
242 if (entry->m_Address == address ||
243 entry->m_Permission == AccessPermission_NotPresent) {
244 // Already in the cache or we found an empty entry
245 return true;
246 }
247 } else {
248 return true;
249 }
250 }
251 return false;
252}
253
254AbstractCacheEntry*
255CacheMemory::allocate(Addr address, AbstractCacheEntry *entry, bool touch)
256{
257 assert(address == makeLineAddress(address));
258 assert(!isTagPresent(address));
259 assert(cacheAvail(address));
260 DPRINTF(RubyCache, "address: %#x\n", address);
261
262 // Find the first open slot
263 int64_t cacheSet = addressToCacheSet(address);
264 std::vector<AbstractCacheEntry*> &set = m_cache[cacheSet];
265 for (int i = 0; i < m_cache_assoc; i++) {
266 if (!set[i] || set[i]->m_Permission == AccessPermission_NotPresent) {
267 if (set[i] && (set[i] != entry)) {
268 warn_once("This protocol contains a cache entry handling bug: "
269 "Entries in the cache should never be NotPresent! If\n"
270 "this entry (%#x) is not tracked elsewhere, it will memory "
271 "leak here. Fix your protocol to eliminate these!",
272 address);
273 }
274 set[i] = entry; // Init entry
275 set[i]->m_Address = address;
276 set[i]->m_Permission = AccessPermission_Invalid;
277 DPRINTF(RubyCache, "Allocate clearing lock for addr: %x\n",
278 address);
279 set[i]->m_locked = -1;
280 m_tag_index[address] = i;
281 entry->setSetIndex(cacheSet);
282 entry->setWayIndex(i);
283
284 if (touch) {
285 m_replacementPolicy_ptr->touch(cacheSet, i, curTick());
286 }
287
288 return entry;
289 }
290 }
291 panic("Allocate didn't find an available entry");
292}
293
294void
295CacheMemory::deallocate(Addr address)
296{
297 assert(address == makeLineAddress(address));
298 assert(isTagPresent(address));
299 DPRINTF(RubyCache, "address: %#x\n", address);
300 int64_t cacheSet = addressToCacheSet(address);
301 int loc = findTagInSet(cacheSet, address);
302 if (loc != -1) {
303 delete m_cache[cacheSet][loc];
304 m_cache[cacheSet][loc] = NULL;
305 m_tag_index.erase(address);
306 }
307}
308
309// Returns with the physical address of the conflicting cache line
310Addr
311CacheMemory::cacheProbe(Addr address) const
312{
313 assert(address == makeLineAddress(address));
314 assert(!cacheAvail(address));
315
316 int64_t cacheSet = addressToCacheSet(address);
317 return m_cache[cacheSet][m_replacementPolicy_ptr->getVictim(cacheSet)]->
318 m_Address;
319}
320
321// looks an address up in the cache
322AbstractCacheEntry*
323CacheMemory::lookup(Addr address)
324{
325 assert(address == makeLineAddress(address));
326 int64_t cacheSet = addressToCacheSet(address);
327 int loc = findTagInSet(cacheSet, address);
328 if (loc == -1) return NULL;
329 return m_cache[cacheSet][loc];
330}
331
332// looks an address up in the cache
333const AbstractCacheEntry*
334CacheMemory::lookup(Addr address) const
335{
336 assert(address == makeLineAddress(address));
337 int64_t cacheSet = addressToCacheSet(address);
338 int loc = findTagInSet(cacheSet, address);
339 if (loc == -1) return NULL;
340 return m_cache[cacheSet][loc];
341}
342
343// Sets the most recently used bit for a cache block
344void
345CacheMemory::setMRU(Addr address)
346{
347 int64_t cacheSet = addressToCacheSet(address);
348 int loc = findTagInSet(cacheSet, address);
349
350 if (loc != -1)
351 m_replacementPolicy_ptr->touch(cacheSet, loc, curTick());
352}
353
354void
355CacheMemory::setMRU(const AbstractCacheEntry *e)
356{
357 uint32_t cacheSet = e->getSetIndex();
358 uint32_t loc = e->getWayIndex();
359 m_replacementPolicy_ptr->touch(cacheSet, loc, curTick());
360}
361
362void
363CacheMemory::setMRU(Addr address, int occupancy)
364{
365 int64_t cacheSet = addressToCacheSet(address);
366 int loc = findTagInSet(cacheSet, address);
367
368 if (loc != -1) {
369 if (m_replacementPolicy_ptr->useOccupancy()) {
370 (static_cast<WeightedLRUPolicy*>(m_replacementPolicy_ptr))->
371 touch(cacheSet, loc, curTick(), occupancy);
372 } else {
373 m_replacementPolicy_ptr->
374 touch(cacheSet, loc, curTick());
375 }
376 }
377}
378
379int
380CacheMemory::getReplacementWeight(int64_t set, int64_t loc)
381{
382 assert(set < m_cache_num_sets);
383 assert(loc < m_cache_assoc);
384 int ret = 0;
385 if (m_cache[set][loc] != NULL) {
386 ret = m_cache[set][loc]->getNumValidBlocks();
387 assert(ret >= 0);
388 }
389
390 return ret;
391}
392
393void
394CacheMemory::recordCacheContents(int cntrl, CacheRecorder* tr) const
395{
396 uint64_t warmedUpBlocks = 0;
397 uint64_t totalBlocks M5_VAR_USED = (uint64_t)m_cache_num_sets *
398 (uint64_t)m_cache_assoc;
399
400 for (int i = 0; i < m_cache_num_sets; i++) {
401 for (int j = 0; j < m_cache_assoc; j++) {
402 if (m_cache[i][j] != NULL) {
403 AccessPermission perm = m_cache[i][j]->m_Permission;
404 RubyRequestType request_type = RubyRequestType_NULL;
405 if (perm == AccessPermission_Read_Only) {
406 if (m_is_instruction_only_cache) {
407 request_type = RubyRequestType_IFETCH;
408 } else {
409 request_type = RubyRequestType_LD;
410 }
411 } else if (perm == AccessPermission_Read_Write) {
412 request_type = RubyRequestType_ST;
413 }
414
415 if (request_type != RubyRequestType_NULL) {
416 tr->addRecord(cntrl, m_cache[i][j]->m_Address,
417 0, request_type,
418 m_replacementPolicy_ptr->getLastAccess(i, j),
419 m_cache[i][j]->getDataBlk());
420 warmedUpBlocks++;
421 }
422 }
423 }
424 }
425
426 DPRINTF(RubyCacheTrace, "%s: %lli blocks of %lli total blocks"
427 "recorded %.2f%% \n", name().c_str(), warmedUpBlocks,
428 totalBlocks, (float(warmedUpBlocks) / float(totalBlocks)) * 100.0);
429}
430
431void
432CacheMemory::print(ostream& out) const
433{
434 out << "Cache dump: " << name() << endl;
435 for (int i = 0; i < m_cache_num_sets; i++) {
436 for (int j = 0; j < m_cache_assoc; j++) {
437 if (m_cache[i][j] != NULL) {
438 out << " Index: " << i
439 << " way: " << j
440 << " entry: " << *m_cache[i][j] << endl;
441 } else {
442 out << " Index: " << i
443 << " way: " << j
444 << " entry: NULL" << endl;
445 }
446 }
447 }
448}
449
450void
451CacheMemory::printData(ostream& out) const
452{
453 out << "printData() not supported" << endl;
454}
455
456void
457CacheMemory::setLocked(Addr address, int context)
458{
459 DPRINTF(RubyCache, "Setting Lock for addr: %#x to %d\n", address, context);
460 assert(address == makeLineAddress(address));
461 int64_t cacheSet = addressToCacheSet(address);
462 int loc = findTagInSet(cacheSet, address);
463 assert(loc != -1);
464 m_cache[cacheSet][loc]->setLocked(context);
465}
466
467void
468CacheMemory::clearLocked(Addr address)
469{
470 DPRINTF(RubyCache, "Clear Lock for addr: %#x\n", address);
471 assert(address == makeLineAddress(address));
472 int64_t cacheSet = addressToCacheSet(address);
473 int loc = findTagInSet(cacheSet, address);
474 assert(loc != -1);
475 m_cache[cacheSet][loc]->clearLocked();
476}
477
478bool
479CacheMemory::isLocked(Addr address, int context)
480{
481 assert(address == makeLineAddress(address));
482 int64_t cacheSet = addressToCacheSet(address);
483 int loc = findTagInSet(cacheSet, address);
484 assert(loc != -1);
485 DPRINTF(RubyCache, "Testing Lock for addr: %#llx cur %d con %d\n",
486 address, m_cache[cacheSet][loc]->m_locked, context);
487 return m_cache[cacheSet][loc]->isLocked(context);
488}
489
490void
491CacheMemory::regStats()
492{
493 SimObject::regStats();
494
495 m_demand_hits
496 .name(name() + ".demand_hits")
497 .desc("Number of cache demand hits")
498 ;
499
500 m_demand_misses
501 .name(name() + ".demand_misses")
502 .desc("Number of cache demand misses")
503 ;
504
505 m_demand_accesses
506 .name(name() + ".demand_accesses")
507 .desc("Number of cache demand accesses")
508 ;
509
510 m_demand_accesses = m_demand_hits + m_demand_misses;
511
512 m_sw_prefetches
513 .name(name() + ".total_sw_prefetches")
514 .desc("Number of software prefetches")
515 .flags(Stats::nozero)
516 ;
517
518 m_hw_prefetches
519 .name(name() + ".total_hw_prefetches")
520 .desc("Number of hardware prefetches")
521 .flags(Stats::nozero)
522 ;
523
524 m_prefetches
525 .name(name() + ".total_prefetches")
526 .desc("Number of prefetches")
527 .flags(Stats::nozero)
528 ;
529
530 m_prefetches = m_sw_prefetches + m_hw_prefetches;
531
532 m_accessModeType
533 .init(RubyRequestType_NUM)
534 .name(name() + ".access_mode")
535 .flags(Stats::pdf | Stats::total)
536 ;
537 for (int i = 0; i < RubyAccessMode_NUM; i++) {
538 m_accessModeType
539 .subname(i, RubyAccessMode_to_string(RubyAccessMode(i)))
540 .flags(Stats::nozero)
541 ;
542 }
543
544 numDataArrayReads
545 .name(name() + ".num_data_array_reads")
546 .desc("number of data array reads")
547 .flags(Stats::nozero)
548 ;
549
550 numDataArrayWrites
551 .name(name() + ".num_data_array_writes")
552 .desc("number of data array writes")
553 .flags(Stats::nozero)
554 ;
555
556 numTagArrayReads
557 .name(name() + ".num_tag_array_reads")
558 .desc("number of tag array reads")
559 .flags(Stats::nozero)
560 ;
561
562 numTagArrayWrites
563 .name(name() + ".num_tag_array_writes")
564 .desc("number of tag array writes")
565 .flags(Stats::nozero)
566 ;
567
568 numTagArrayStalls
569 .name(name() + ".num_tag_array_stalls")
570 .desc("number of stalls caused by tag array")
571 .flags(Stats::nozero)
572 ;
573
574 numDataArrayStalls
575 .name(name() + ".num_data_array_stalls")
576 .desc("number of stalls caused by data array")
577 .flags(Stats::nozero)
578 ;
579}
580
581// assumption: SLICC generated files will only call this function
582// once **all** resources are granted
583void
584CacheMemory::recordRequestType(CacheRequestType requestType, Addr addr)
585{
586 DPRINTF(RubyStats, "Recorded statistic: %s\n",
587 CacheRequestType_to_string(requestType));
588 switch(requestType) {
589 case CacheRequestType_DataArrayRead:
590 if (m_resource_stalls)
591 dataArray.reserve(addressToCacheSet(addr));
592 numDataArrayReads++;
593 return;
594 case CacheRequestType_DataArrayWrite:
595 if (m_resource_stalls)
596 dataArray.reserve(addressToCacheSet(addr));
597 numDataArrayWrites++;
598 return;
599 case CacheRequestType_TagArrayRead:
600 if (m_resource_stalls)
601 tagArray.reserve(addressToCacheSet(addr));
602 numTagArrayReads++;
603 return;
604 case CacheRequestType_TagArrayWrite:
605 if (m_resource_stalls)
606 tagArray.reserve(addressToCacheSet(addr));
607 numTagArrayWrites++;
608 return;
609 default:
610 warn("CacheMemory access_type not found: %s",
611 CacheRequestType_to_string(requestType));
612 }
613}
614
615bool
616CacheMemory::checkResourceAvailable(CacheResourceType res, Addr addr)
617{
618 if (!m_resource_stalls) {
619 return true;
620 }
621
622 if (res == CacheResourceType_TagArray) {
623 if (tagArray.tryAccess(addressToCacheSet(addr))) return true;
624 else {
625 DPRINTF(RubyResourceStalls,
626 "Tag array stall on addr %#x in set %d\n",
627 addr, addressToCacheSet(addr));
628 numTagArrayStalls++;
629 return false;
630 }
631 } else if (res == CacheResourceType_DataArray) {
632 if (dataArray.tryAccess(addressToCacheSet(addr))) return true;
633 else {
634 DPRINTF(RubyResourceStalls,
635 "Data array stall on addr %#x in set %d\n",
636 addr, addressToCacheSet(addr));
637 numDataArrayStalls++;
638 return false;
639 }
640 } else {
|