cache.hh revision 5034:6186ef720dd4
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 std::vector<Range<Addr> > filterRanges); 77 78 // BaseCache::CachePort just has a BaseCache *; this function 79 // lets us get back the type info we lost when we stored the 80 // cache pointer there. 81 Cache<TagStore> *myCache() { 82 return static_cast<Cache<TagStore> *>(cache); 83 } 84 85 virtual void getDeviceAddressRanges(AddrRangeList &resp, 86 bool &snoop); 87 88 virtual bool recvTiming(PacketPtr pkt); 89 90 virtual Tick recvAtomic(PacketPtr pkt); 91 92 virtual void recvFunctional(PacketPtr pkt); 93 }; 94 95 class MemSidePort : public CachePort 96 { 97 public: 98 MemSidePort(const std::string &_name, 99 Cache<TagStore> *_cache, 100 std::vector<Range<Addr> > filterRanges); 101 102 // BaseCache::CachePort just has a BaseCache *; this function 103 // lets us get back the type info we lost when we stored the 104 // cache pointer there. 105 Cache<TagStore> *myCache() { 106 return static_cast<Cache<TagStore> *>(cache); 107 } 108 109 void sendPacket(); 110 111 void processSendEvent(); 112 113 virtual void getDeviceAddressRanges(AddrRangeList &resp, 114 bool &snoop); 115 116 virtual bool recvTiming(PacketPtr pkt); 117 118 virtual void recvRetry(); 119 120 virtual Tick recvAtomic(PacketPtr pkt); 121 122 virtual void recvFunctional(PacketPtr pkt); 123 124 typedef EventWrapper<MemSidePort, &MemSidePort::processSendEvent> 125 SendEvent; 126 }; 127 128 /** Tag and data Storage */ 129 TagStore *tags; 130 131 /** Prefetcher */ 132 BasePrefetcher *prefetcher; 133 134 /** Temporary cache block for occasional transitory use */ 135 BlkType *tempBlock; 136 137 /** 138 * Can this cache should allocate a block on a line-sized write miss. 139 */ 140 const bool doFastWrites; 141 142 const bool prefetchMiss; 143 144 /** 145 * Handle a replacement for the given request. 146 * @param blk A pointer to the block, usually NULL 147 * @param pkt The memory request to satisfy. 148 * @param new_state The new state of the block. 149 * @param writebacks A list to store any generated writebacks. 150 */ 151 BlkType* doReplacement(BlkType *blk, PacketPtr pkt, 152 CacheBlk::State new_state, PacketList &writebacks); 153 154 /** 155 * Does all the processing necessary to perform the provided request. 156 * @param pkt The memory request to perform. 157 * @param lat The latency of the access. 158 * @param writebacks List for any writebacks that need to be performed. 159 * @param update True if the replacement data should be updated. 160 * @return Pointer to the cache block touched by the request. NULL if it 161 * was a miss. 162 */ 163 bool access(PacketPtr pkt, BlkType *&blk, int &lat); 164 165 /** 166 *Handle doing the Compare and Swap function for SPARC. 167 */ 168 void cmpAndSwap(BlkType *blk, PacketPtr pkt); 169 170 /** 171 * Populates a cache block and handles all outstanding requests for the 172 * satisfied fill request. This version takes two memory requests. One 173 * contains the fill data, the other is an optional target to satisfy. 174 * Used for Cache::probe. 175 * @param pkt The memory request with the fill data. 176 * @param blk The cache block if it already exists. 177 * @param writebacks List for any writebacks that need to be performed. 178 * @return Pointer to the new cache block. 179 */ 180 BlkType *handleFill(PacketPtr pkt, BlkType *blk, 181 PacketList &writebacks); 182 183 void satisfyCpuSideRequest(PacketPtr pkt, BlkType *blk); 184 bool satisfyMSHR(MSHR *mshr, PacketPtr pkt, BlkType *blk); 185 186 void doTimingSupplyResponse(PacketPtr req_pkt, uint8_t *blk_data, 187 bool already_copied); 188 189 /** 190 * Sets the blk to the new state. 191 * @param blk The cache block being snooped. 192 * @param new_state The new coherence state for the block. 193 */ 194 void handleSnoop(PacketPtr ptk, BlkType *blk, 195 bool is_timing, bool is_deferred); 196 197 /** 198 * Create a writeback request for the given block. 199 * @param blk The block to writeback. 200 * @return The writeback request for the block. 201 */ 202 PacketPtr writebackBlk(BlkType *blk); 203 204 public: 205 /** Instantiates a basic cache object. */ 206 Cache(const Params *p, TagStore *tags, BasePrefetcher *prefetcher); 207 208 virtual Port *getPort(const std::string &if_name, int idx = -1); 209 virtual void deletePortRefs(Port *p); 210 211 void regStats(); 212 213 /** 214 * Performs the access specified by the request. 215 * @param pkt The request to perform. 216 * @return The result of the access. 217 */ 218 bool timingAccess(PacketPtr pkt); 219 220 /** 221 * Performs the access specified by the request. 222 * @param pkt The request to perform. 223 * @return The result of the access. 224 */ 225 Tick atomicAccess(PacketPtr pkt); 226 227 /** 228 * Performs the access specified by the request. 229 * @param pkt The request to perform. 230 * @return The result of the access. 231 */ 232 void functionalAccess(PacketPtr pkt, CachePort *otherSidePort); 233 234 /** 235 * Handles a response (cache line fill/write ack) from the bus. 236 * @param pkt The request being responded to. 237 */ 238 void handleResponse(PacketPtr pkt); 239 240 /** 241 * Snoops bus transactions to maintain coherence. 242 * @param pkt The current bus transaction. 243 */ 244 void snoopTiming(PacketPtr pkt); 245 246 /** 247 * Snoop for the provided request in the cache and return the estimated 248 * time of completion. 249 * @param pkt The memory request to snoop 250 * @return The estimated completion time. 251 */ 252 Tick snoopAtomic(PacketPtr pkt); 253 254 /** 255 * Squash all requests associated with specified thread. 256 * intended for use by I-cache. 257 * @param threadNum The thread to squash. 258 */ 259 void squash(int threadNum); 260 261 /** 262 * Selects a outstanding request to service. 263 * @return The request to service, NULL if none found. 264 */ 265 PacketPtr getBusPacket(PacketPtr cpu_pkt, BlkType *blk, 266 bool needsExclusive); 267 MSHR *getNextMSHR(); 268 PacketPtr getTimingPacket(); 269 270 /** 271 * Marks a request as in service (sent on the bus). This can have side 272 * effect since storage for no response commands is deallocated once they 273 * are successfully sent. 274 * @param pkt The request that was sent on the bus. 275 */ 276 void markInService(MSHR *mshr); 277 278 /** 279 * Perform the given writeback request. 280 * @param pkt The writeback request. 281 */ 282 void doWriteback(PacketPtr pkt); 283 284 /** 285 * Return whether there are any outstanding misses. 286 */ 287 bool outstandingMisses() const 288 { 289 return mshrQueue.allocated != 0; 290 } 291 292 CacheBlk *findBlock(Addr addr) { 293 return tags->findBlock(addr); 294 } 295 296 bool inCache(Addr addr) { 297 return (tags->findBlock(addr) != 0); 298 } 299 300 bool inMissQueue(Addr addr) { 301 return (mshrQueue.findMatch(addr) != 0); 302 } 303}; 304 305#endif // __CACHE_HH__ 306