cache.hh revision 4672
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/misc.hh" // fatal, panic, and warn 43 44#include "mem/cache/base_cache.hh" 45#include "mem/cache/cache_blk.hh" 46#include "mem/cache/miss/mshr.hh" 47 48#include "sim/eventq.hh" 49 50//Forward decleration 51class BasePrefetcher; 52 53/** 54 * A template-policy based cache. The behavior of the cache can be altered by 55 * supplying different template policies. TagStore handles all tag and data 56 * storage @sa TagStore. 57 */ 58template <class TagStore> 59class Cache : public BaseCache 60{ 61 public: 62 /** Define the type of cache block to use. */ 63 typedef typename TagStore::BlkType BlkType; 64 /** A typedef for a list of BlkType pointers. */ 65 typedef typename TagStore::BlkList BlkList; 66 67 bool prefetchAccess; 68 69 protected: 70 71 class CpuSidePort : public CachePort 72 { 73 public: 74 CpuSidePort(const std::string &_name, 75 Cache<TagStore> *_cache); 76 77 // BaseCache::CachePort just has a BaseCache *; this function 78 // lets us get back the type info we lost when we stored the 79 // cache pointer there. 80 Cache<TagStore> *myCache() { 81 return static_cast<Cache<TagStore> *>(cache); 82 } 83 84 virtual void getDeviceAddressRanges(AddrRangeList &resp, 85 bool &snoop); 86 87 virtual bool recvTiming(PacketPtr pkt); 88 89 virtual Tick recvAtomic(PacketPtr pkt); 90 91 virtual void recvFunctional(PacketPtr pkt); 92 }; 93 94 class MemSidePort : public CachePort 95 { 96 public: 97 MemSidePort(const std::string &_name, 98 Cache<TagStore> *_cache); 99 100 // BaseCache::CachePort just has a BaseCache *; this function 101 // lets us get back the type info we lost when we stored the 102 // cache pointer there. 103 Cache<TagStore> *myCache() { 104 return static_cast<Cache<TagStore> *>(cache); 105 } 106 107 void sendPacket(); 108 109 void processSendEvent(); 110 111 virtual void getDeviceAddressRanges(AddrRangeList &resp, 112 bool &snoop); 113 114 virtual bool recvTiming(PacketPtr pkt); 115 116 virtual void recvRetry(); 117 118 virtual Tick recvAtomic(PacketPtr pkt); 119 120 virtual void recvFunctional(PacketPtr pkt); 121 122 typedef EventWrapper<MemSidePort, &MemSidePort::processSendEvent> 123 SendEvent; 124 }; 125 126 /** Tag and data Storage */ 127 TagStore *tags; 128 129 /** Prefetcher */ 130 BasePrefetcher *prefetcher; 131 132 /** Temporary cache block for occasional transitory use */ 133 BlkType *tempBlock; 134 135 /** 136 * Can this cache should allocate a block on a line-sized write miss. 137 */ 138 const bool doFastWrites; 139 140 const bool prefetchMiss; 141 142 /** 143 * Handle a replacement for the given request. 144 * @param blk A pointer to the block, usually NULL 145 * @param pkt The memory request to satisfy. 146 * @param new_state The new state of the block. 147 * @param writebacks A list to store any generated writebacks. 148 */ 149 BlkType* doReplacement(BlkType *blk, PacketPtr pkt, 150 CacheBlk::State new_state, PacketList &writebacks); 151 152 /** 153 * Does all the processing necessary to perform the provided request. 154 * @param pkt The memory request to perform. 155 * @param lat The latency of the access. 156 * @param writebacks List for any writebacks that need to be performed. 157 * @param update True if the replacement data should be updated. 158 * @return Pointer to the cache block touched by the request. NULL if it 159 * was a miss. 160 */ 161 bool access(PacketPtr pkt, BlkType *&blk, int &lat); 162 163 /** 164 *Handle doing the Compare and Swap function for SPARC. 165 */ 166 void cmpAndSwap(BlkType *blk, PacketPtr pkt); 167 168 /** 169 * Populates a cache block and handles all outstanding requests for the 170 * satisfied fill request. This version takes two memory requests. One 171 * contains the fill data, the other is an optional target to satisfy. 172 * Used for Cache::probe. 173 * @param pkt The memory request with the fill data. 174 * @param blk The cache block if it already exists. 175 * @param writebacks List for any writebacks that need to be performed. 176 * @return Pointer to the new cache block. 177 */ 178 BlkType *handleFill(PacketPtr pkt, BlkType *blk, 179 PacketList &writebacks); 180 181 void satisfyCpuSideRequest(PacketPtr pkt, BlkType *blk); 182 bool satisfyMSHR(MSHR *mshr, PacketPtr pkt, BlkType *blk); 183 184 void doTimingSupplyResponse(PacketPtr req_pkt, uint8_t *blk_data, 185 bool already_copied); 186 187 /** 188 * Sets the blk to the new state. 189 * @param blk The cache block being snooped. 190 * @param new_state The new coherence state for the block. 191 */ 192 void handleSnoop(PacketPtr ptk, BlkType *blk, 193 bool is_timing, bool is_deferred); 194 195 /** 196 * Create a writeback request for the given block. 197 * @param blk The block to writeback. 198 * @return The writeback request for the block. 199 */ 200 PacketPtr writebackBlk(BlkType *blk); 201 202 public: 203 204 class Params 205 { 206 public: 207 TagStore *tags; 208 BaseCache::Params baseParams; 209 BasePrefetcher*prefetcher; 210 bool prefetchAccess; 211 const bool doFastWrites; 212 const bool prefetchMiss; 213 214 Params(TagStore *_tags, 215 BaseCache::Params params, 216 BasePrefetcher *_prefetcher, 217 bool prefetch_access, int hit_latency, 218 bool do_fast_writes, 219 bool prefetch_miss) 220 : tags(_tags), 221 baseParams(params), 222 prefetcher(_prefetcher), prefetchAccess(prefetch_access), 223 doFastWrites(do_fast_writes), 224 prefetchMiss(prefetch_miss) 225 { 226 } 227 }; 228 229 /** Instantiates a basic cache object. */ 230 Cache(const std::string &_name, Params ¶ms); 231 232 virtual Port *getPort(const std::string &if_name, int idx = -1); 233 virtual void deletePortRefs(Port *p); 234 235 void regStats(); 236 237 /** 238 * Performs the access specified by the request. 239 * @param pkt The request to perform. 240 * @return The result of the access. 241 */ 242 bool timingAccess(PacketPtr pkt); 243 244 /** 245 * Performs the access specified by the request. 246 * @param pkt The request to perform. 247 * @return The result of the access. 248 */ 249 Tick atomicAccess(PacketPtr pkt); 250 251 /** 252 * Performs the access specified by the request. 253 * @param pkt The request to perform. 254 * @return The result of the access. 255 */ 256 void functionalAccess(PacketPtr pkt, CachePort *otherSidePort); 257 258 /** 259 * Handles a response (cache line fill/write ack) from the bus. 260 * @param pkt The request being responded to. 261 */ 262 void handleResponse(PacketPtr pkt); 263 264 /** 265 * Snoops bus transactions to maintain coherence. 266 * @param pkt The current bus transaction. 267 */ 268 void snoopTiming(PacketPtr pkt); 269 270 /** 271 * Snoop for the provided request in the cache and return the estimated 272 * time of completion. 273 * @param pkt The memory request to snoop 274 * @return The estimated completion time. 275 */ 276 Tick snoopAtomic(PacketPtr pkt); 277 278 /** 279 * Squash all requests associated with specified thread. 280 * intended for use by I-cache. 281 * @param threadNum The thread to squash. 282 */ 283 void squash(int threadNum); 284 285 /** 286 * Selects a outstanding request to service. 287 * @return The request to service, NULL if none found. 288 */ 289 PacketPtr getBusPacket(PacketPtr cpu_pkt, BlkType *blk, 290 bool needsExclusive); 291 MSHR *getNextMSHR(); 292 PacketPtr getTimingPacket(); 293 294 /** 295 * Marks a request as in service (sent on the bus). This can have side 296 * effect since storage for no response commands is deallocated once they 297 * are successfully sent. 298 * @param pkt The request that was sent on the bus. 299 */ 300 void markInService(MSHR *mshr); 301 302 /** 303 * Perform the given writeback request. 304 * @param pkt The writeback request. 305 */ 306 void doWriteback(PacketPtr pkt); 307 308 /** 309 * Return whether there are any outstanding misses. 310 */ 311 bool outstandingMisses() const 312 { 313 return mshrQueue.allocated != 0; 314 } 315 316 CacheBlk *findBlock(Addr addr) { 317 return tags->findBlock(addr); 318 } 319 320 bool inCache(Addr addr) { 321 return (tags->findBlock(addr) != 0); 322 } 323 324 bool inMissQueue(Addr addr) { 325 return (mshrQueue.findMatch(addr) != 0); 326 } 327}; 328 329#endif // __CACHE_HH__ 330