CacheMemory.cc revision 11793:ef606668d247
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" 33#include "debug/RubyCache.hh" 34#include "debug/RubyCacheTrace.hh" 35#include "debug/RubyResourceStalls.hh" 36#include "debug/RubyStats.hh" 37#include "mem/protocol/AccessPermission.hh" 38#include "mem/ruby/system/RubySystem.hh" 39#include "mem/ruby/system/WeightedLRUPolicy.hh" 40 41using namespace std; 42 43ostream& 44operator<<(ostream& out, const CacheMemory& obj) 45{ 46 obj.print(out); 47 out << flush; 48 return out; 49} 50 51CacheMemory * 52RubyCacheParams::create() 53{ 54 return new CacheMemory(this); 55} 56 57CacheMemory::CacheMemory(const Params *p) 58 : SimObject(p), 59 dataArray(p->dataArrayBanks, p->dataAccessLatency, 60 p->start_index_bit, p->ruby_system), 61 tagArray(p->tagArrayBanks, p->tagAccessLatency, 62 p->start_index_bit, p->ruby_system) 63{ 64 m_cache_size = p->size; 65 m_cache_assoc = p->assoc; 66 m_replacementPolicy_ptr = p->replacement_policy; 67 m_replacementPolicy_ptr->setCache(this); 68 m_start_index_bit = p->start_index_bit; 69 m_is_instruction_only_cache = p->is_icache; 70 m_resource_stalls = p->resourceStalls; 71 m_block_size = p->block_size; // may be 0 at this point. Updated in init() 72} 73 74void 75CacheMemory::init() 76{ 77 if (m_block_size == 0) { 78 m_block_size = RubySystem::getBlockSizeBytes(); 79 } 80 m_cache_num_sets = (m_cache_size / m_cache_assoc) / m_block_size; 81 assert(m_cache_num_sets > 1); 82 m_cache_num_set_bits = floorLog2(m_cache_num_sets); 83 assert(m_cache_num_set_bits > 0); 84 85 m_cache.resize(m_cache_num_sets, 86 std::vector<AbstractCacheEntry*>(m_cache_assoc, nullptr)); 87} 88 89CacheMemory::~CacheMemory() 90{ 91 if (m_replacementPolicy_ptr) 92 delete m_replacementPolicy_ptr; 93 for (int i = 0; i < m_cache_num_sets; i++) { 94 for (int j = 0; j < m_cache_assoc; j++) { 95 delete m_cache[i][j]; 96 } 97 } 98} 99 100// convert a Address to its location in the cache 101int64_t 102CacheMemory::addressToCacheSet(Addr address) const 103{ 104 assert(address == makeLineAddress(address)); 105 return bitSelect(address, m_start_index_bit, 106 m_start_index_bit + m_cache_num_set_bits - 1); 107} 108 109// Given a cache index: returns the index of the tag in a set. 110// returns -1 if the tag is not found. 111int 112CacheMemory::findTagInSet(int64_t cacheSet, Addr tag) const 113{ 114 assert(tag == makeLineAddress(tag)); 115 // search the set for the tags 116 auto it = m_tag_index.find(tag); 117 if (it != m_tag_index.end()) 118 if (m_cache[cacheSet][it->second]->m_Permission != 119 AccessPermission_NotPresent) 120 return it->second; 121 return -1; // Not found 122} 123 124// Given a cache index: returns the index of the tag in a set. 125// returns -1 if the tag is not found. 126int 127CacheMemory::findTagInSetIgnorePermissions(int64_t cacheSet, 128 Addr tag) const 129{ 130 assert(tag == makeLineAddress(tag)); 131 // search the set for the tags 132 auto it = m_tag_index.find(tag); 133 if (it != m_tag_index.end()) 134 return it->second; 135 return -1; // Not found 136} 137 138// Given an unique cache block identifier (idx): return the valid address 139// stored by the cache block. If the block is invalid/notpresent, the 140// function returns the 0 address 141Addr 142CacheMemory::getAddressAtIdx(int idx) const 143{ 144 Addr tmp(0); 145 146 int set = idx / m_cache_assoc; 147 assert(set < m_cache_num_sets); 148 149 int way = idx - set * m_cache_assoc; 150 assert (way < m_cache_assoc); 151 152 AbstractCacheEntry* entry = m_cache[set][way]; 153 if (entry == NULL || 154 entry->m_Permission == AccessPermission_Invalid || 155 entry->m_Permission == AccessPermission_NotPresent) { 156 return tmp; 157 } 158 return entry->m_Address; 159} 160 161bool 162CacheMemory::tryCacheAccess(Addr address, RubyRequestType type, 163 DataBlock*& data_ptr) 164{ 165 assert(address == makeLineAddress(address)); 166 DPRINTF(RubyCache, "address: %#x\n", address); 167 int64_t cacheSet = addressToCacheSet(address); 168 int loc = findTagInSet(cacheSet, address); 169 if (loc != -1) { 170 // Do we even have a tag match? 171 AbstractCacheEntry* entry = m_cache[cacheSet][loc]; 172 m_replacementPolicy_ptr->touch(cacheSet, loc, curTick()); 173 data_ptr = &(entry->getDataBlk()); 174 175 if (entry->m_Permission == AccessPermission_Read_Write) { 176 return true; 177 } 178 if ((entry->m_Permission == AccessPermission_Read_Only) && 179 (type == RubyRequestType_LD || type == RubyRequestType_IFETCH)) { 180 return true; 181 } 182 // The line must not be accessible 183 } 184 data_ptr = NULL; 185 return false; 186} 187 188bool 189CacheMemory::testCacheAccess(Addr address, RubyRequestType type, 190 DataBlock*& data_ptr) 191{ 192 assert(address == makeLineAddress(address)); 193 DPRINTF(RubyCache, "address: %#x\n", address); 194 int64_t cacheSet = addressToCacheSet(address); 195 int loc = findTagInSet(cacheSet, address); 196 197 if (loc != -1) { 198 // Do we even have a tag match? 199 AbstractCacheEntry* entry = m_cache[cacheSet][loc]; 200 m_replacementPolicy_ptr->touch(cacheSet, loc, curTick()); 201 data_ptr = &(entry->getDataBlk()); 202 203 return m_cache[cacheSet][loc]->m_Permission != 204 AccessPermission_NotPresent; 205 } 206 207 data_ptr = NULL; 208 return false; 209} 210 211// tests to see if an address is present in the cache 212bool 213CacheMemory::isTagPresent(Addr address) const 214{ 215 assert(address == makeLineAddress(address)); 216 int64_t cacheSet = addressToCacheSet(address); 217 int loc = findTagInSet(cacheSet, address); 218 219 if (loc == -1) { 220 // We didn't find the tag 221 DPRINTF(RubyCache, "No tag match for address: %#x\n", address); 222 return false; 223 } 224 DPRINTF(RubyCache, "address: %#x found\n", address); 225 return true; 226} 227 228// Returns true if there is: 229// a) a tag match on this address or there is 230// b) an unused line in the same cache "way" 231bool 232CacheMemory::cacheAvail(Addr address) const 233{ 234 assert(address == makeLineAddress(address)); 235 236 int64_t cacheSet = addressToCacheSet(address); 237 238 for (int i = 0; i < m_cache_assoc; i++) { 239 AbstractCacheEntry* entry = m_cache[cacheSet][i]; 240 if (entry != NULL) { 241 if (entry->m_Address == address || 242 entry->m_Permission == AccessPermission_NotPresent) { 243 // Already in the cache or we found an empty entry 244 return true; 245 } 246 } else { 247 return true; 248 } 249 } 250 return false; 251} 252 253AbstractCacheEntry* 254CacheMemory::allocate(Addr address, AbstractCacheEntry *entry, bool touch) 255{ 256 assert(address == makeLineAddress(address)); 257 assert(!isTagPresent(address)); 258 assert(cacheAvail(address)); 259 DPRINTF(RubyCache, "address: %#x\n", address); 260 261 // Find the first open slot 262 int64_t cacheSet = addressToCacheSet(address); 263 std::vector<AbstractCacheEntry*> &set = m_cache[cacheSet]; 264 for (int i = 0; i < m_cache_assoc; i++) { 265 if (!set[i] || set[i]->m_Permission == AccessPermission_NotPresent) { 266 if (set[i] && (set[i] != entry)) { 267 warn_once("This protocol contains a cache entry handling bug: " 268 "Entries in the cache should never be NotPresent! If\n" 269 "this entry (%#x) is not tracked elsewhere, it will memory " 270 "leak here. Fix your protocol to eliminate these!", 271 address); 272 } 273 set[i] = entry; // Init entry 274 set[i]->m_Address = address; 275 set[i]->m_Permission = AccessPermission_Invalid; 276 DPRINTF(RubyCache, "Allocate clearing lock for addr: %x\n", 277 address); 278 set[i]->m_locked = -1; 279 m_tag_index[address] = i; 280 entry->setSetIndex(cacheSet); 281 entry->setWayIndex(i); 282 283 if (touch) { 284 m_replacementPolicy_ptr->touch(cacheSet, i, curTick()); 285 } 286 287 return entry; 288 } 289 } 290 panic("Allocate didn't find an available entry"); 291} 292 293void 294CacheMemory::deallocate(Addr address) 295{ 296 assert(address == makeLineAddress(address)); 297 assert(isTagPresent(address)); 298 DPRINTF(RubyCache, "address: %#x\n", address); 299 int64_t cacheSet = addressToCacheSet(address); 300 int loc = findTagInSet(cacheSet, address); 301 if (loc != -1) { 302 delete m_cache[cacheSet][loc]; 303 m_cache[cacheSet][loc] = NULL; 304 m_tag_index.erase(address); 305 } 306} 307 308// Returns with the physical address of the conflicting cache line 309Addr 310CacheMemory::cacheProbe(Addr address) const 311{ 312 assert(address == makeLineAddress(address)); 313 assert(!cacheAvail(address)); 314 315 int64_t cacheSet = addressToCacheSet(address); 316 return m_cache[cacheSet][m_replacementPolicy_ptr->getVictim(cacheSet)]-> 317 m_Address; 318} 319 320// looks an address up in the cache 321AbstractCacheEntry* 322CacheMemory::lookup(Addr address) 323{ 324 assert(address == makeLineAddress(address)); 325 int64_t cacheSet = addressToCacheSet(address); 326 int loc = findTagInSet(cacheSet, address); 327 if (loc == -1) return NULL; 328 return m_cache[cacheSet][loc]; 329} 330 331// looks an address up in the cache 332const AbstractCacheEntry* 333CacheMemory::lookup(Addr address) const 334{ 335 assert(address == makeLineAddress(address)); 336 int64_t cacheSet = addressToCacheSet(address); 337 int loc = findTagInSet(cacheSet, address); 338 if (loc == -1) return NULL; 339 return m_cache[cacheSet][loc]; 340} 341 342// Sets the most recently used bit for a cache block 343void 344CacheMemory::setMRU(Addr address) 345{ 346 int64_t cacheSet = addressToCacheSet(address); 347 int loc = findTagInSet(cacheSet, address); 348 349 if (loc != -1) 350 m_replacementPolicy_ptr->touch(cacheSet, loc, curTick()); 351} 352 353void 354CacheMemory::setMRU(const AbstractCacheEntry *e) 355{ 356 uint32_t cacheSet = e->getSetIndex(); 357 uint32_t loc = e->getWayIndex(); 358 m_replacementPolicy_ptr->touch(cacheSet, loc, curTick()); 359} 360 361void 362CacheMemory::setMRU(Addr address, int occupancy) 363{ 364 int64_t cacheSet = addressToCacheSet(address); 365 int loc = findTagInSet(cacheSet, address); 366 367 if (loc != -1) { 368 if (m_replacementPolicy_ptr->useOccupancy()) { 369 (static_cast<WeightedLRUPolicy*>(m_replacementPolicy_ptr))-> 370 touch(cacheSet, loc, curTick(), occupancy); 371 } else { 372 m_replacementPolicy_ptr-> 373 touch(cacheSet, loc, curTick()); 374 } 375 } 376} 377 378int 379CacheMemory::getReplacementWeight(int64_t set, int64_t loc) 380{ 381 assert(set < m_cache_num_sets); 382 assert(loc < m_cache_assoc); 383 int ret = 0; 384 if (m_cache[set][loc] != NULL) { 385 ret = m_cache[set][loc]->getNumValidBlocks(); 386 assert(ret >= 0); 387 } 388 389 return ret; 390} 391 392void 393CacheMemory::recordCacheContents(int cntrl, CacheRecorder* tr) const 394{ 395 uint64_t warmedUpBlocks = 0; 396 uint64_t totalBlocks M5_VAR_USED = (uint64_t)m_cache_num_sets * 397 (uint64_t)m_cache_assoc; 398 399 for (int i = 0; i < m_cache_num_sets; i++) { 400 for (int j = 0; j < m_cache_assoc; j++) { 401 if (m_cache[i][j] != NULL) { 402 AccessPermission perm = m_cache[i][j]->m_Permission; 403 RubyRequestType request_type = RubyRequestType_NULL; 404 if (perm == AccessPermission_Read_Only) { 405 if (m_is_instruction_only_cache) { 406 request_type = RubyRequestType_IFETCH; 407 } else { 408 request_type = RubyRequestType_LD; 409 } 410 } else if (perm == AccessPermission_Read_Write) { 411 request_type = RubyRequestType_ST; 412 } 413 414 if (request_type != RubyRequestType_NULL) { 415 tr->addRecord(cntrl, m_cache[i][j]->m_Address, 416 0, request_type, 417 m_replacementPolicy_ptr->getLastAccess(i, j), 418 m_cache[i][j]->getDataBlk()); 419 warmedUpBlocks++; 420 } 421 } 422 } 423 } 424 425 DPRINTF(RubyCacheTrace, "%s: %lli blocks of %lli total blocks" 426 "recorded %.2f%% \n", name().c_str(), warmedUpBlocks, 427 totalBlocks, (float(warmedUpBlocks) / float(totalBlocks)) * 100.0); 428} 429 430void 431CacheMemory::print(ostream& out) const 432{ 433 out << "Cache dump: " << name() << endl; 434 for (int i = 0; i < m_cache_num_sets; i++) { 435 for (int j = 0; j < m_cache_assoc; j++) { 436 if (m_cache[i][j] != NULL) { 437 out << " Index: " << i 438 << " way: " << j 439 << " entry: " << *m_cache[i][j] << endl; 440 } else { 441 out << " Index: " << i 442 << " way: " << j 443 << " entry: NULL" << endl; 444 } 445 } 446 } 447} 448 449void 450CacheMemory::printData(ostream& out) const 451{ 452 out << "printData() not supported" << endl; 453} 454 455void 456CacheMemory::setLocked(Addr address, int context) 457{ 458 DPRINTF(RubyCache, "Setting Lock for addr: %#x to %d\n", address, context); 459 assert(address == makeLineAddress(address)); 460 int64_t cacheSet = addressToCacheSet(address); 461 int loc = findTagInSet(cacheSet, address); 462 assert(loc != -1); 463 m_cache[cacheSet][loc]->setLocked(context); 464} 465 466void 467CacheMemory::clearLocked(Addr address) 468{ 469 DPRINTF(RubyCache, "Clear Lock for addr: %#x\n", address); 470 assert(address == makeLineAddress(address)); 471 int64_t cacheSet = addressToCacheSet(address); 472 int loc = findTagInSet(cacheSet, address); 473 assert(loc != -1); 474 m_cache[cacheSet][loc]->clearLocked(); 475} 476 477bool 478CacheMemory::isLocked(Addr address, int context) 479{ 480 assert(address == makeLineAddress(address)); 481 int64_t cacheSet = addressToCacheSet(address); 482 int loc = findTagInSet(cacheSet, address); 483 assert(loc != -1); 484 DPRINTF(RubyCache, "Testing Lock for addr: %#llx cur %d con %d\n", 485 address, m_cache[cacheSet][loc]->m_locked, context); 486 return m_cache[cacheSet][loc]->isLocked(context); 487} 488 489void 490CacheMemory::regStats() 491{ 492 SimObject::regStats(); 493 494 m_demand_hits 495 .name(name() + ".demand_hits") 496 .desc("Number of cache demand hits") 497 ; 498 499 m_demand_misses 500 .name(name() + ".demand_misses") 501 .desc("Number of cache demand misses") 502 ; 503 504 m_demand_accesses 505 .name(name() + ".demand_accesses") 506 .desc("Number of cache demand accesses") 507 ; 508 509 m_demand_accesses = m_demand_hits + m_demand_misses; 510 511 m_sw_prefetches 512 .name(name() + ".total_sw_prefetches") 513 .desc("Number of software prefetches") 514 .flags(Stats::nozero) 515 ; 516 517 m_hw_prefetches 518 .name(name() + ".total_hw_prefetches") 519 .desc("Number of hardware prefetches") 520 .flags(Stats::nozero) 521 ; 522 523 m_prefetches 524 .name(name() + ".total_prefetches") 525 .desc("Number of prefetches") 526 .flags(Stats::nozero) 527 ; 528 529 m_prefetches = m_sw_prefetches + m_hw_prefetches; 530 531 m_accessModeType 532 .init(RubyRequestType_NUM) 533 .name(name() + ".access_mode") 534 .flags(Stats::pdf | Stats::total) 535 ; 536 for (int i = 0; i < RubyAccessMode_NUM; i++) { 537 m_accessModeType 538 .subname(i, RubyAccessMode_to_string(RubyAccessMode(i))) 539 .flags(Stats::nozero) 540 ; 541 } 542 543 numDataArrayReads 544 .name(name() + ".num_data_array_reads") 545 .desc("number of data array reads") 546 .flags(Stats::nozero) 547 ; 548 549 numDataArrayWrites 550 .name(name() + ".num_data_array_writes") 551 .desc("number of data array writes") 552 .flags(Stats::nozero) 553 ; 554 555 numTagArrayReads 556 .name(name() + ".num_tag_array_reads") 557 .desc("number of tag array reads") 558 .flags(Stats::nozero) 559 ; 560 561 numTagArrayWrites 562 .name(name() + ".num_tag_array_writes") 563 .desc("number of tag array writes") 564 .flags(Stats::nozero) 565 ; 566 567 numTagArrayStalls 568 .name(name() + ".num_tag_array_stalls") 569 .desc("number of stalls caused by tag array") 570 .flags(Stats::nozero) 571 ; 572 573 numDataArrayStalls 574 .name(name() + ".num_data_array_stalls") 575 .desc("number of stalls caused by data array") 576 .flags(Stats::nozero) 577 ; 578} 579 580// assumption: SLICC generated files will only call this function 581// once **all** resources are granted 582void 583CacheMemory::recordRequestType(CacheRequestType requestType, Addr addr) 584{ 585 DPRINTF(RubyStats, "Recorded statistic: %s\n", 586 CacheRequestType_to_string(requestType)); 587 switch(requestType) { 588 case CacheRequestType_DataArrayRead: 589 if (m_resource_stalls) 590 dataArray.reserve(addressToCacheSet(addr)); 591 numDataArrayReads++; 592 return; 593 case CacheRequestType_DataArrayWrite: 594 if (m_resource_stalls) 595 dataArray.reserve(addressToCacheSet(addr)); 596 numDataArrayWrites++; 597 return; 598 case CacheRequestType_TagArrayRead: 599 if (m_resource_stalls) 600 tagArray.reserve(addressToCacheSet(addr)); 601 numTagArrayReads++; 602 return; 603 case CacheRequestType_TagArrayWrite: 604 if (m_resource_stalls) 605 tagArray.reserve(addressToCacheSet(addr)); 606 numTagArrayWrites++; 607 return; 608 default: 609 warn("CacheMemory access_type not found: %s", 610 CacheRequestType_to_string(requestType)); 611 } 612} 613 614bool 615CacheMemory::checkResourceAvailable(CacheResourceType res, Addr addr) 616{ 617 if (!m_resource_stalls) { 618 return true; 619 } 620 621 if (res == CacheResourceType_TagArray) { 622 if (tagArray.tryAccess(addressToCacheSet(addr))) return true; 623 else { 624 DPRINTF(RubyResourceStalls, 625 "Tag array stall on addr %#x in set %d\n", 626 addr, addressToCacheSet(addr)); 627 numTagArrayStalls++; 628 return false; 629 } 630 } else if (res == CacheResourceType_DataArray) { 631 if (dataArray.tryAccess(addressToCacheSet(addr))) return true; 632 else { 633 DPRINTF(RubyResourceStalls, 634 "Data array stall on addr %#x in set %d\n", 635 addr, addressToCacheSet(addr)); 636 numDataArrayStalls++; 637 return false; 638 } 639 } else { 640 assert(false); 641 return true; 642 } 643} 644 645bool 646CacheMemory::isBlockInvalid(int64_t cache_set, int64_t loc) 647{ 648 return (m_cache[cache_set][loc]->m_Permission == AccessPermission_Invalid); 649} 650 651bool 652CacheMemory::isBlockNotBusy(int64_t cache_set, int64_t loc) 653{ 654 return (m_cache[cache_set][loc]->m_Permission != AccessPermission_Busy); 655} 656