cache.hh revision 5875:d82be3235ab4
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.hh" 45#include "mem/cache/blk.hh" 46#include "mem/cache/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 protected: 68 69 class CpuSidePort : public CachePort 70 { 71 public: 72 CpuSidePort(const std::string &_name, 73 Cache<TagStore> *_cache, 74 const std::string &_label, 75 std::vector<Range<Addr> > filterRanges); 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 const std::string &_label, 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 * This cache should allocate a block on a line-sized write miss. 139 */ 140 const bool doFastWrites; 141 142 /** 143 * Notify the prefetcher on every access, not just misses. 144 */ 145 const bool prefetchOnAccess; 146 147 /** 148 * Does all the processing necessary to perform the provided request. 149 * @param pkt The memory request to perform. 150 * @param lat The latency of the access. 151 * @param writebacks List for any writebacks that need to be performed. 152 * @param update True if the replacement data should be updated. 153 * @return Boolean indicating whether the request was satisfied. 154 */ 155 bool access(PacketPtr pkt, BlkType *&blk, 156 int &lat, PacketList &writebacks); 157 158 /** 159 *Handle doing the Compare and Swap function for SPARC. 160 */ 161 void cmpAndSwap(BlkType *blk, PacketPtr pkt); 162 163 /** 164 * Find a block frame for new block at address addr, assuming that 165 * the block is not currently in the cache. Append writebacks if 166 * any to provided packet list. Return free block frame. May 167 * return NULL if there are no replaceable blocks at the moment. 168 */ 169 BlkType *allocateBlock(Addr addr, PacketList &writebacks); 170 171 /** 172 * Populates a cache block and handles all outstanding requests for the 173 * satisfied fill request. This version takes two memory requests. One 174 * contains the fill data, the other is an optional target to satisfy. 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, bool pending_inval); 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, bool pending_inval); 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 *incomingPort, 233 CachePort *otherSidePort); 234 235 /** 236 * Handles a response (cache line fill/write ack) from the bus. 237 * @param pkt The request being responded to. 238 */ 239 void handleResponse(PacketPtr pkt); 240 241 /** 242 * Snoops bus transactions to maintain coherence. 243 * @param pkt The current bus transaction. 244 */ 245 void snoopTiming(PacketPtr pkt); 246 247 /** 248 * Snoop for the provided request in the cache and return the estimated 249 * time of completion. 250 * @param pkt The memory request to snoop 251 * @return The estimated completion time. 252 */ 253 Tick snoopAtomic(PacketPtr pkt); 254 255 /** 256 * Squash all requests associated with specified thread. 257 * intended for use by I-cache. 258 * @param threadNum The thread to squash. 259 */ 260 void squash(int threadNum); 261 262 /** 263 * Generate an appropriate downstream bus request packet for the 264 * given parameters. 265 * @param cpu_pkt The upstream request that needs to be satisfied. 266 * @param blk The block currently in the cache corresponding to 267 * cpu_pkt (NULL if none). 268 * @param needsExclusive Indicates that an exclusive copy is required 269 * even if the request in cpu_pkt doesn't indicate that. 270 * @return A new Packet containing the request, or NULL if the 271 * current request in cpu_pkt should just be forwarded on. 272 */ 273 PacketPtr getBusPacket(PacketPtr cpu_pkt, BlkType *blk, 274 bool needsExclusive); 275 276 /** 277 * Return the next MSHR to service, either a pending miss from the 278 * mshrQueue, a buffered write from the write buffer, or something 279 * from the prefetcher. This function is responsible for 280 * prioritizing among those sources on the fly. 281 */ 282 MSHR *getNextMSHR(); 283 284 /** 285 * Selects an outstanding request to service. Called when the 286 * cache gets granted the downstream bus in timing mode. 287 * @return The request to service, NULL if none found. 288 */ 289 PacketPtr getTimingPacket(); 290 291 /** 292 * Marks a request as in service (sent on the bus). This can have side 293 * effect since storage for no response commands is deallocated once they 294 * are successfully sent. 295 * @param pkt The request that was sent on the bus. 296 */ 297 void markInService(MSHR *mshr); 298 299 /** 300 * Perform the given writeback request. 301 * @param pkt The writeback request. 302 */ 303 void doWriteback(PacketPtr pkt); 304 305 /** 306 * Return whether there are any outstanding misses. 307 */ 308 bool outstandingMisses() const 309 { 310 return mshrQueue.allocated != 0; 311 } 312 313 CacheBlk *findBlock(Addr addr) { 314 return tags->findBlock(addr); 315 } 316 317 bool inCache(Addr addr) { 318 return (tags->findBlock(addr) != 0); 319 } 320 321 bool inMissQueue(Addr addr) { 322 return (mshrQueue.findMatch(addr) != 0); 323 } 324 325 /** 326 * Find next request ready time from among possible sources. 327 */ 328 Tick nextMSHRReadyTime(); 329}; 330 331#endif // __CACHE_HH__ 332