cache.hh revision 4630:5a832c366b22
1/* 2 * Copyright (c) 2002-2005 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 * Dave Greene 30 * Steve Reinhardt 31 * Ron Dreslinski 32 */ 33 34/** 35 * @file 36 * Describes a cache based on template policies. 37 */ 38 39#ifndef __CACHE_HH__ 40#define __CACHE_HH__ 41 42#include "base/compression/base.hh" 43#include "base/misc.hh" // fatal, panic, and warn 44#include "cpu/smt.hh" // SMT_MAX_THREADS 45 46#include "mem/cache/base_cache.hh" 47#include "mem/cache/cache_blk.hh" 48#include "mem/cache/miss/mshr.hh" 49 50#include "sim/eventq.hh" 51 52//Forward decleration 53class BasePrefetcher; 54 55/** 56 * A template-policy based cache. The behavior of the cache can be altered by 57 * supplying different template policies. TagStore handles all tag and data 58 * storage @sa TagStore. Buffering handles all misses and writes/writebacks 59 * @sa MissQueue. Coherence handles all coherence policy details @sa 60 * UniCoherence, SimpleMultiCoherence. 61 */ 62template <class TagStore, class Coherence> 63class Cache : public BaseCache 64{ 65 public: 66 /** Define the type of cache block to use. */ 67 typedef typename TagStore::BlkType BlkType; 68 /** A typedef for a list of BlkType pointers. */ 69 typedef typename TagStore::BlkList BlkList; 70 71 bool prefetchAccess; 72 73 protected: 74 75 class CpuSidePort : public CachePort 76 { 77 public: 78 CpuSidePort(const std::string &_name, 79 Cache<TagStore,Coherence> *_cache); 80 81 // BaseCache::CachePort just has a BaseCache *; this function 82 // lets us get back the type info we lost when we stored the 83 // cache pointer there. 84 Cache<TagStore,Coherence> *myCache() { 85 return static_cast<Cache<TagStore,Coherence> *>(cache); 86 } 87 88 virtual void getDeviceAddressRanges(AddrRangeList &resp, 89 bool &snoop); 90 91 virtual bool recvTiming(PacketPtr pkt); 92 93 virtual Tick recvAtomic(PacketPtr pkt); 94 95 virtual void recvFunctional(PacketPtr pkt); 96 }; 97 98 class MemSidePort : public CachePort 99 { 100 public: 101 MemSidePort(const std::string &_name, 102 Cache<TagStore,Coherence> *_cache); 103 104 // BaseCache::CachePort just has a BaseCache *; this function 105 // lets us get back the type info we lost when we stored the 106 // cache pointer there. 107 Cache<TagStore,Coherence> *myCache() { 108 return static_cast<Cache<TagStore,Coherence> *>(cache); 109 } 110 111 void sendPacket(); 112 113 void processSendEvent(); 114 115 virtual void getDeviceAddressRanges(AddrRangeList &resp, 116 bool &snoop); 117 118 virtual bool recvTiming(PacketPtr pkt); 119 120 virtual void recvRetry(); 121 122 virtual Tick recvAtomic(PacketPtr pkt); 123 124 virtual void recvFunctional(PacketPtr pkt); 125 126 typedef EventWrapper<MemSidePort, &MemSidePort::processSendEvent> 127 SendEvent; 128 }; 129 130 /** Tag and data Storage */ 131 TagStore *tags; 132 133 /** Coherence protocol. */ 134 Coherence *coherence; 135 136 /** Prefetcher */ 137 BasePrefetcher *prefetcher; 138 139 /** 140 * Can this cache should allocate a block on a line-sized write miss. 141 */ 142 const bool doFastWrites; 143 144 const bool prefetchMiss; 145 146 /** 147 * Handle a replacement for the given request. 148 * @param blk A pointer to the block, usually NULL 149 * @param pkt The memory request to satisfy. 150 * @param new_state The new state of the block. 151 * @param writebacks A list to store any generated writebacks. 152 */ 153 BlkType* doReplacement(BlkType *blk, PacketPtr pkt, 154 CacheBlk::State new_state, PacketList &writebacks); 155 156 /** 157 * Does all the processing necessary to perform the provided request. 158 * @param pkt The memory request to perform. 159 * @param lat The latency of the access. 160 * @param writebacks List for any writebacks that need to be performed. 161 * @param update True if the replacement data should be updated. 162 * @return Pointer to the cache block touched by the request. NULL if it 163 * was a miss. 164 */ 165 bool access(PacketPtr pkt, BlkType *&blk, int &lat); 166 167 /** 168 *Handle doing the Compare and Swap function for SPARC. 169 */ 170 void cmpAndSwap(BlkType *blk, PacketPtr pkt); 171 172 /** 173 * Populates a cache block and handles all outstanding requests for the 174 * satisfied fill request. This version takes two memory requests. One 175 * contains the fill data, the other is an optional target to satisfy. 176 * Used for Cache::probe. 177 * @param pkt The memory request with the fill data. 178 * @param blk The cache block if it already exists. 179 * @param writebacks List for any writebacks that need to be performed. 180 * @return Pointer to the new cache block. 181 */ 182 BlkType *handleFill(PacketPtr pkt, BlkType *blk, 183 PacketList &writebacks); 184 185 bool satisfyCpuSideRequest(PacketPtr pkt, BlkType *blk); 186 bool satisfyTarget(MSHR::Target *target, BlkType *blk); 187 bool satisfyMSHR(MSHR *mshr, PacketPtr pkt, BlkType *blk); 188 189 void doTimingSupplyResponse(PacketPtr req_pkt, uint8_t *blk_data); 190 191 /** 192 * Sets the blk to the new state. 193 * @param blk The cache block being snooped. 194 * @param new_state The new coherence state for the block. 195 */ 196 void handleSnoop(PacketPtr ptk, BlkType *blk, bool is_timing); 197 198 /** 199 * Create a writeback request for the given block. 200 * @param blk The block to writeback. 201 * @return The writeback request for the block. 202 */ 203 PacketPtr writebackBlk(BlkType *blk); 204 205 public: 206 207 class Params 208 { 209 public: 210 TagStore *tags; 211 Coherence *coherence; 212 BaseCache::Params baseParams; 213 BasePrefetcher*prefetcher; 214 bool prefetchAccess; 215 const bool doFastWrites; 216 const bool prefetchMiss; 217 218 Params(TagStore *_tags, Coherence *coh, 219 BaseCache::Params params, 220 BasePrefetcher *_prefetcher, 221 bool prefetch_access, int hit_latency, 222 bool do_fast_writes, 223 bool prefetch_miss) 224 : tags(_tags), coherence(coh), 225 baseParams(params), 226 prefetcher(_prefetcher), prefetchAccess(prefetch_access), 227 doFastWrites(do_fast_writes), 228 prefetchMiss(prefetch_miss) 229 { 230 } 231 }; 232 233 /** Instantiates a basic cache object. */ 234 Cache(const std::string &_name, Params ¶ms); 235 236 virtual Port *getPort(const std::string &if_name, int idx = -1); 237 virtual void deletePortRefs(Port *p); 238 239 void regStats(); 240 241 /** 242 * Performs the access specified by the request. 243 * @param pkt The request to perform. 244 * @return The result of the access. 245 */ 246 bool timingAccess(PacketPtr pkt); 247 248 /** 249 * Performs the access specified by the request. 250 * @param pkt The request to perform. 251 * @return The result of the access. 252 */ 253 Tick atomicAccess(PacketPtr pkt); 254 255 /** 256 * Performs the access specified by the request. 257 * @param pkt The request to perform. 258 * @return The result of the access. 259 */ 260 void functionalAccess(PacketPtr pkt, CachePort *otherSidePort); 261 262 /** 263 * Handles a response (cache line fill/write ack) from the bus. 264 * @param pkt The request being responded to. 265 */ 266 void handleResponse(PacketPtr pkt); 267 268 /** 269 * Snoops bus transactions to maintain coherence. 270 * @param pkt The current bus transaction. 271 */ 272 void snoopTiming(PacketPtr pkt); 273 274 /** 275 * Snoop for the provided request in the cache and return the estimated 276 * time of completion. 277 * @param pkt The memory request to snoop 278 * @return The estimated completion time. 279 */ 280 Tick snoopAtomic(PacketPtr pkt); 281 282 /** 283 * Squash all requests associated with specified thread. 284 * intended for use by I-cache. 285 * @param threadNum The thread to squash. 286 */ 287 void squash(int threadNum); 288 289 /** 290 * Selects a outstanding request to service. 291 * @return The request to service, NULL if none found. 292 */ 293 PacketPtr getBusPacket(PacketPtr cpu_pkt, BlkType *blk, 294 bool needsExclusive); 295 MSHR *getNextMSHR(); 296 PacketPtr getTimingPacket(); 297 298 /** 299 * Marks a request as in service (sent on the bus). This can have side 300 * effect since storage for no response commands is deallocated once they 301 * are successfully sent. 302 * @param pkt The request that was sent on the bus. 303 */ 304 void markInService(MSHR *mshr); 305 306 /** 307 * Perform the given writeback request. 308 * @param pkt The writeback request. 309 */ 310 void doWriteback(PacketPtr pkt); 311 312 /** 313 * Return whether there are any outstanding misses. 314 */ 315 bool outstandingMisses() const 316 { 317 return mshrQueue.allocated != 0; 318 } 319 320 CacheBlk *findBlock(Addr addr) { 321 return tags->findBlock(addr); 322 } 323 324 bool inCache(Addr addr) { 325 return (tags->findBlock(addr) != 0); 326 } 327 328 bool inMissQueue(Addr addr) { 329 return (mshrQueue.findMatch(addr) != 0); 330 } 331}; 332 333#endif // __CACHE_HH__ 334