cache.hh revision 4671:5d29d3be0f79
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 /** Temporary cache block for occasional transitory use */ 140 BlkType *tempBlock; 141 142 /** 143 * Can this cache should allocate a block on a line-sized write miss. 144 */ 145 const bool doFastWrites; 146 147 const bool prefetchMiss; 148 149 /** 150 * Handle a replacement for the given request. 151 * @param blk A pointer to the block, usually NULL 152 * @param pkt The memory request to satisfy. 153 * @param new_state The new state of the block. 154 * @param writebacks A list to store any generated writebacks. 155 */ 156 BlkType* doReplacement(BlkType *blk, PacketPtr pkt, 157 CacheBlk::State new_state, PacketList &writebacks); 158 159 /** 160 * Does all the processing necessary to perform the provided request. 161 * @param pkt The memory request to perform. 162 * @param lat The latency of the access. 163 * @param writebacks List for any writebacks that need to be performed. 164 * @param update True if the replacement data should be updated. 165 * @return Pointer to the cache block touched by the request. NULL if it 166 * was a miss. 167 */ 168 bool access(PacketPtr pkt, BlkType *&blk, int &lat); 169 170 /** 171 *Handle doing the Compare and Swap function for SPARC. 172 */ 173 void cmpAndSwap(BlkType *blk, PacketPtr pkt); 174 175 /** 176 * Populates a cache block and handles all outstanding requests for the 177 * satisfied fill request. This version takes two memory requests. One 178 * contains the fill data, the other is an optional target to satisfy. 179 * Used for Cache::probe. 180 * @param pkt The memory request with the fill data. 181 * @param blk The cache block if it already exists. 182 * @param writebacks List for any writebacks that need to be performed. 183 * @return Pointer to the new cache block. 184 */ 185 BlkType *handleFill(PacketPtr pkt, BlkType *blk, 186 PacketList &writebacks); 187 188 void satisfyCpuSideRequest(PacketPtr pkt, BlkType *blk); 189 bool satisfyMSHR(MSHR *mshr, PacketPtr pkt, BlkType *blk); 190 191 void doTimingSupplyResponse(PacketPtr req_pkt, uint8_t *blk_data, 192 bool already_copied); 193 194 /** 195 * Sets the blk to the new state. 196 * @param blk The cache block being snooped. 197 * @param new_state The new coherence state for the block. 198 */ 199 void handleSnoop(PacketPtr ptk, BlkType *blk, 200 bool is_timing, bool is_deferred); 201 202 /** 203 * Create a writeback request for the given block. 204 * @param blk The block to writeback. 205 * @return The writeback request for the block. 206 */ 207 PacketPtr writebackBlk(BlkType *blk); 208 209 public: 210 211 class Params 212 { 213 public: 214 TagStore *tags; 215 Coherence *coherence; 216 BaseCache::Params baseParams; 217 BasePrefetcher*prefetcher; 218 bool prefetchAccess; 219 const bool doFastWrites; 220 const bool prefetchMiss; 221 222 Params(TagStore *_tags, Coherence *coh, 223 BaseCache::Params params, 224 BasePrefetcher *_prefetcher, 225 bool prefetch_access, int hit_latency, 226 bool do_fast_writes, 227 bool prefetch_miss) 228 : tags(_tags), coherence(coh), 229 baseParams(params), 230 prefetcher(_prefetcher), prefetchAccess(prefetch_access), 231 doFastWrites(do_fast_writes), 232 prefetchMiss(prefetch_miss) 233 { 234 } 235 }; 236 237 /** Instantiates a basic cache object. */ 238 Cache(const std::string &_name, Params ¶ms); 239 240 virtual Port *getPort(const std::string &if_name, int idx = -1); 241 virtual void deletePortRefs(Port *p); 242 243 void regStats(); 244 245 /** 246 * Performs the access specified by the request. 247 * @param pkt The request to perform. 248 * @return The result of the access. 249 */ 250 bool timingAccess(PacketPtr pkt); 251 252 /** 253 * Performs the access specified by the request. 254 * @param pkt The request to perform. 255 * @return The result of the access. 256 */ 257 Tick atomicAccess(PacketPtr pkt); 258 259 /** 260 * Performs the access specified by the request. 261 * @param pkt The request to perform. 262 * @return The result of the access. 263 */ 264 void functionalAccess(PacketPtr pkt, CachePort *otherSidePort); 265 266 /** 267 * Handles a response (cache line fill/write ack) from the bus. 268 * @param pkt The request being responded to. 269 */ 270 void handleResponse(PacketPtr pkt); 271 272 /** 273 * Snoops bus transactions to maintain coherence. 274 * @param pkt The current bus transaction. 275 */ 276 void snoopTiming(PacketPtr pkt); 277 278 /** 279 * Snoop for the provided request in the cache and return the estimated 280 * time of completion. 281 * @param pkt The memory request to snoop 282 * @return The estimated completion time. 283 */ 284 Tick snoopAtomic(PacketPtr pkt); 285 286 /** 287 * Squash all requests associated with specified thread. 288 * intended for use by I-cache. 289 * @param threadNum The thread to squash. 290 */ 291 void squash(int threadNum); 292 293 /** 294 * Selects a outstanding request to service. 295 * @return The request to service, NULL if none found. 296 */ 297 PacketPtr getBusPacket(PacketPtr cpu_pkt, BlkType *blk, 298 bool needsExclusive); 299 MSHR *getNextMSHR(); 300 PacketPtr getTimingPacket(); 301 302 /** 303 * Marks a request as in service (sent on the bus). This can have side 304 * effect since storage for no response commands is deallocated once they 305 * are successfully sent. 306 * @param pkt The request that was sent on the bus. 307 */ 308 void markInService(MSHR *mshr); 309 310 /** 311 * Perform the given writeback request. 312 * @param pkt The writeback request. 313 */ 314 void doWriteback(PacketPtr pkt); 315 316 /** 317 * Return whether there are any outstanding misses. 318 */ 319 bool outstandingMisses() const 320 { 321 return mshrQueue.allocated != 0; 322 } 323 324 CacheBlk *findBlock(Addr addr) { 325 return tags->findBlock(addr); 326 } 327 328 bool inCache(Addr addr) { 329 return (tags->findBlock(addr) != 0); 330 } 331 332 bool inMissQueue(Addr addr) { 333 return (mshrQueue.findMatch(addr) != 0); 334 } 335}; 336 337#endif // __CACHE_HH__ 338