base.hh revision 6666:3199397fd905
1/* 2 * Copyright (c) 2003-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Erik Hallnor 29 * Steve Reinhardt 30 * Ron Dreslinski 31 */ 32 33/** 34 * @file 35 * Declares a basic cache interface BaseCache. 36 */ 37 38#ifndef __BASE_CACHE_HH__ 39#define __BASE_CACHE_HH__ 40 41#include <vector> 42#include <string> 43#include <list> 44#include <algorithm> 45 46#include "base/misc.hh" 47#include "base/statistics.hh" 48#include "base/trace.hh" 49#include "base/types.hh" 50#include "mem/cache/mshr_queue.hh" 51#include "mem/mem_object.hh" 52#include "mem/packet.hh" 53#include "mem/tport.hh" 54#include "mem/request.hh" 55#include "params/BaseCache.hh" 56#include "sim/eventq.hh" 57#include "sim/sim_exit.hh" 58 59class MSHR; 60/** 61 * A basic cache interface. Implements some common functions for speed. 62 */ 63class BaseCache : public MemObject 64{ 65 /** 66 * Indexes to enumerate the MSHR queues. 67 */ 68 enum MSHRQueueIndex { 69 MSHRQueue_MSHRs, 70 MSHRQueue_WriteBuffer 71 }; 72 73 /** 74 * Reasons for caches to be blocked. 75 */ 76 enum BlockedCause { 77 Blocked_NoMSHRs = MSHRQueue_MSHRs, 78 Blocked_NoWBBuffers = MSHRQueue_WriteBuffer, 79 Blocked_NoTargets, 80 NUM_BLOCKED_CAUSES 81 }; 82 83 public: 84 /** 85 * Reasons for cache to request a bus. 86 */ 87 enum RequestCause { 88 Request_MSHR = MSHRQueue_MSHRs, 89 Request_WB = MSHRQueue_WriteBuffer, 90 Request_PF, 91 NUM_REQUEST_CAUSES 92 }; 93 94 private: 95 96 class CachePort : public SimpleTimingPort 97 { 98 public: 99 BaseCache *cache; 100 101 protected: 102 CachePort(const std::string &_name, BaseCache *_cache, 103 const std::string &_label); 104 105 virtual void recvStatusChange(Status status); 106 107 virtual unsigned deviceBlockSize() const; 108 109 bool recvRetryCommon(); 110 111 typedef EventWrapper<Port, &Port::sendRetry> 112 SendRetryEvent; 113 114 const std::string label; 115 116 public: 117 void setOtherPort(CachePort *_otherPort) { otherPort = _otherPort; } 118 119 void setBlocked(); 120 121 void clearBlocked(); 122 123 bool checkFunctional(PacketPtr pkt); 124 125 CachePort *otherPort; 126 127 bool blocked; 128 129 bool mustSendRetry; 130 131 void requestBus(RequestCause cause, Tick time) 132 { 133 DPRINTF(CachePort, "Asserting bus request for cause %d\n", cause); 134 if (!waitingOnRetry) { 135 schedSendEvent(time); 136 } 137 } 138 139 void respond(PacketPtr pkt, Tick time) { 140 schedSendTiming(pkt, time); 141 } 142 }; 143 144 public: //Made public so coherence can get at it. 145 CachePort *cpuSidePort; 146 CachePort *memSidePort; 147 148 protected: 149 150 /** Miss status registers */ 151 MSHRQueue mshrQueue; 152 153 /** Write/writeback buffer */ 154 MSHRQueue writeBuffer; 155 156 MSHR *allocateBufferInternal(MSHRQueue *mq, Addr addr, int size, 157 PacketPtr pkt, Tick time, bool requestBus) 158 { 159 MSHR *mshr = mq->allocate(addr, size, pkt, time, order++); 160 161 if (mq->isFull()) { 162 setBlocked((BlockedCause)mq->index); 163 } 164 165 if (requestBus) { 166 requestMemSideBus((RequestCause)mq->index, time); 167 } 168 169 return mshr; 170 } 171 172 void markInServiceInternal(MSHR *mshr) 173 { 174 MSHRQueue *mq = mshr->queue; 175 bool wasFull = mq->isFull(); 176 mq->markInService(mshr); 177 if (wasFull && !mq->isFull()) { 178 clearBlocked((BlockedCause)mq->index); 179 } 180 } 181 182 /** Block size of this cache */ 183 const unsigned blkSize; 184 185 /** 186 * The latency of a hit in this device. 187 */ 188 int hitLatency; 189 190 /** The number of targets for each MSHR. */ 191 const int numTarget; 192 193 /** Do we forward snoops from mem side port through to cpu side port? */ 194 bool forwardSnoops; 195 196 /** 197 * Bit vector of the blocking reasons for the access path. 198 * @sa #BlockedCause 199 */ 200 uint8_t blocked; 201 202 /** Increasing order number assigned to each incoming request. */ 203 uint64_t order; 204 205 /** Stores time the cache blocked for statistics. */ 206 Tick blockedCycle; 207 208 /** Pointer to the MSHR that has no targets. */ 209 MSHR *noTargetMSHR; 210 211 /** The number of misses to trigger an exit event. */ 212 Counter missCount; 213 214 /** The drain event. */ 215 Event *drainEvent; 216 217 /** 218 * The address range to which the cache responds on the CPU side. 219 * Normally this is all possible memory addresses. */ 220 Range<Addr> addrRange; 221 222 public: 223 // Statistics 224 /** 225 * @addtogroup CacheStatistics 226 * @{ 227 */ 228 229 /** Number of hits per thread for each type of command. @sa Packet::Command */ 230 Stats::Vector hits[MemCmd::NUM_MEM_CMDS]; 231 /** Number of hits for demand accesses. */ 232 Stats::Formula demandHits; 233 /** Number of hit for all accesses. */ 234 Stats::Formula overallHits; 235 236 /** Number of misses per thread for each type of command. @sa Packet::Command */ 237 Stats::Vector misses[MemCmd::NUM_MEM_CMDS]; 238 /** Number of misses for demand accesses. */ 239 Stats::Formula demandMisses; 240 /** Number of misses for all accesses. */ 241 Stats::Formula overallMisses; 242 243 /** 244 * Total number of cycles per thread/command spent waiting for a miss. 245 * Used to calculate the average miss latency. 246 */ 247 Stats::Vector missLatency[MemCmd::NUM_MEM_CMDS]; 248 /** Total number of cycles spent waiting for demand misses. */ 249 Stats::Formula demandMissLatency; 250 /** Total number of cycles spent waiting for all misses. */ 251 Stats::Formula overallMissLatency; 252 253 /** The number of accesses per command and thread. */ 254 Stats::Formula accesses[MemCmd::NUM_MEM_CMDS]; 255 /** The number of demand accesses. */ 256 Stats::Formula demandAccesses; 257 /** The number of overall accesses. */ 258 Stats::Formula overallAccesses; 259 260 /** The miss rate per command and thread. */ 261 Stats::Formula missRate[MemCmd::NUM_MEM_CMDS]; 262 /** The miss rate of all demand accesses. */ 263 Stats::Formula demandMissRate; 264 /** The miss rate for all accesses. */ 265 Stats::Formula overallMissRate; 266 267 /** The average miss latency per command and thread. */ 268 Stats::Formula avgMissLatency[MemCmd::NUM_MEM_CMDS]; 269 /** The average miss latency for demand misses. */ 270 Stats::Formula demandAvgMissLatency; 271 /** The average miss latency for all misses. */ 272 Stats::Formula overallAvgMissLatency; 273 274 /** The total number of cycles blocked for each blocked cause. */ 275 Stats::Vector blocked_cycles; 276 /** The number of times this cache blocked for each blocked cause. */ 277 Stats::Vector blocked_causes; 278 279 /** The average number of cycles blocked for each blocked cause. */ 280 Stats::Formula avg_blocked; 281 282 /** The number of fast writes (WH64) performed. */ 283 Stats::Scalar fastWrites; 284 285 /** The number of cache copies performed. */ 286 Stats::Scalar cacheCopies; 287 288 /** Number of blocks written back per thread. */ 289 Stats::Vector writebacks; 290 291 /** Number of misses that hit in the MSHRs per command and thread. */ 292 Stats::Vector mshr_hits[MemCmd::NUM_MEM_CMDS]; 293 /** Demand misses that hit in the MSHRs. */ 294 Stats::Formula demandMshrHits; 295 /** Total number of misses that hit in the MSHRs. */ 296 Stats::Formula overallMshrHits; 297 298 /** Number of misses that miss in the MSHRs, per command and thread. */ 299 Stats::Vector mshr_misses[MemCmd::NUM_MEM_CMDS]; 300 /** Demand misses that miss in the MSHRs. */ 301 Stats::Formula demandMshrMisses; 302 /** Total number of misses that miss in the MSHRs. */ 303 Stats::Formula overallMshrMisses; 304 305 /** Number of misses that miss in the MSHRs, per command and thread. */ 306 Stats::Vector mshr_uncacheable[MemCmd::NUM_MEM_CMDS]; 307 /** Total number of misses that miss in the MSHRs. */ 308 Stats::Formula overallMshrUncacheable; 309 310 /** Total cycle latency of each MSHR miss, per command and thread. */ 311 Stats::Vector mshr_miss_latency[MemCmd::NUM_MEM_CMDS]; 312 /** Total cycle latency of demand MSHR misses. */ 313 Stats::Formula demandMshrMissLatency; 314 /** Total cycle latency of overall MSHR misses. */ 315 Stats::Formula overallMshrMissLatency; 316 317 /** Total cycle latency of each MSHR miss, per command and thread. */ 318 Stats::Vector mshr_uncacheable_lat[MemCmd::NUM_MEM_CMDS]; 319 /** Total cycle latency of overall MSHR misses. */ 320 Stats::Formula overallMshrUncacheableLatency; 321 322 /** The total number of MSHR accesses per command and thread. */ 323 Stats::Formula mshrAccesses[MemCmd::NUM_MEM_CMDS]; 324 /** The total number of demand MSHR accesses. */ 325 Stats::Formula demandMshrAccesses; 326 /** The total number of MSHR accesses. */ 327 Stats::Formula overallMshrAccesses; 328 329 /** The miss rate in the MSHRs pre command and thread. */ 330 Stats::Formula mshrMissRate[MemCmd::NUM_MEM_CMDS]; 331 /** The demand miss rate in the MSHRs. */ 332 Stats::Formula demandMshrMissRate; 333 /** The overall miss rate in the MSHRs. */ 334 Stats::Formula overallMshrMissRate; 335 336 /** The average latency of an MSHR miss, per command and thread. */ 337 Stats::Formula avgMshrMissLatency[MemCmd::NUM_MEM_CMDS]; 338 /** The average latency of a demand MSHR miss. */ 339 Stats::Formula demandAvgMshrMissLatency; 340 /** The average overall latency of an MSHR miss. */ 341 Stats::Formula overallAvgMshrMissLatency; 342 343 /** The average latency of an MSHR miss, per command and thread. */ 344 Stats::Formula avgMshrUncacheableLatency[MemCmd::NUM_MEM_CMDS]; 345 /** The average overall latency of an MSHR miss. */ 346 Stats::Formula overallAvgMshrUncacheableLatency; 347 348 /** The number of times a thread hit its MSHR cap. */ 349 Stats::Vector mshr_cap_events; 350 /** The number of times software prefetches caused the MSHR to block. */ 351 Stats::Vector soft_prefetch_mshr_full; 352 353 Stats::Scalar mshr_no_allocate_misses; 354 355 /** 356 * @} 357 */ 358 359 /** 360 * Register stats for this object. 361 */ 362 virtual void regStats(); 363 364 public: 365 typedef BaseCacheParams Params; 366 BaseCache(const Params *p); 367 ~BaseCache() {} 368 369 virtual void init(); 370 371 /** 372 * Query block size of a cache. 373 * @return The block size 374 */ 375 unsigned 376 getBlockSize() const 377 { 378 return blkSize; 379 } 380 381 382 Addr blockAlign(Addr addr) const { return (addr & ~(Addr(blkSize - 1))); } 383 384 385 const Range<Addr> &getAddrRange() const { return addrRange; } 386 387 MSHR *allocateMissBuffer(PacketPtr pkt, Tick time, bool requestBus) 388 { 389 assert(!pkt->req->isUncacheable()); 390 return allocateBufferInternal(&mshrQueue, 391 blockAlign(pkt->getAddr()), blkSize, 392 pkt, time, requestBus); 393 } 394 395 MSHR *allocateWriteBuffer(PacketPtr pkt, Tick time, bool requestBus) 396 { 397 assert(pkt->isWrite() && !pkt->isRead()); 398 return allocateBufferInternal(&writeBuffer, 399 pkt->getAddr(), pkt->getSize(), 400 pkt, time, requestBus); 401 } 402 403 MSHR *allocateUncachedReadBuffer(PacketPtr pkt, Tick time, bool requestBus) 404 { 405 assert(pkt->req->isUncacheable()); 406 assert(pkt->isRead()); 407 return allocateBufferInternal(&mshrQueue, 408 pkt->getAddr(), pkt->getSize(), 409 pkt, time, requestBus); 410 } 411 412 /** 413 * Returns true if the cache is blocked for accesses. 414 */ 415 bool isBlocked() 416 { 417 return blocked != 0; 418 } 419 420 /** 421 * Marks the access path of the cache as blocked for the given cause. This 422 * also sets the blocked flag in the slave interface. 423 * @param cause The reason for the cache blocking. 424 */ 425 void setBlocked(BlockedCause cause) 426 { 427 uint8_t flag = 1 << cause; 428 if (blocked == 0) { 429 blocked_causes[cause]++; 430 blockedCycle = curTick; 431 cpuSidePort->setBlocked(); 432 } 433 blocked |= flag; 434 DPRINTF(Cache,"Blocking for cause %d, mask=%d\n", cause, blocked); 435 } 436 437 /** 438 * Marks the cache as unblocked for the given cause. This also clears the 439 * blocked flags in the appropriate interfaces. 440 * @param cause The newly unblocked cause. 441 * @warning Calling this function can cause a blocked request on the bus to 442 * access the cache. The cache must be in a state to handle that request. 443 */ 444 void clearBlocked(BlockedCause cause) 445 { 446 uint8_t flag = 1 << cause; 447 blocked &= ~flag; 448 DPRINTF(Cache,"Unblocking for cause %d, mask=%d\n", cause, blocked); 449 if (blocked == 0) { 450 blocked_cycles[cause] += curTick - blockedCycle; 451 cpuSidePort->clearBlocked(); 452 } 453 } 454 455 /** 456 * Request the master bus for the given cause and time. 457 * @param cause The reason for the request. 458 * @param time The time to make the request. 459 */ 460 void requestMemSideBus(RequestCause cause, Tick time) 461 { 462 memSidePort->requestBus(cause, time); 463 } 464 465 /** 466 * Clear the master bus request for the given cause. 467 * @param cause The request reason to clear. 468 */ 469 void deassertMemSideBusRequest(RequestCause cause) 470 { 471 // Obsolete... we no longer signal bus requests explicitly so 472 // we can't deassert them. Leaving this in as a no-op since 473 // the prefetcher calls it to indicate that it no longer wants 474 // to request a prefetch, and someday that might be 475 // interesting again. 476 } 477 478 virtual unsigned int drain(Event *de); 479 480 virtual bool inCache(Addr addr) = 0; 481 482 virtual bool inMissQueue(Addr addr) = 0; 483 484 void incMissCount(PacketPtr pkt) 485 { 486 misses[pkt->cmdToIndex()][0/*pkt->req->threadId()*/]++; 487 488 if (missCount) { 489 --missCount; 490 if (missCount == 0) 491 exitSimLoop("A cache reached the maximum miss count"); 492 } 493 } 494 495}; 496 497#endif //__BASE_CACHE_HH__ 498