1/* 2 * Copyright (c) 2012-2014,2016-2018 ARM Limited 3 * All rights reserved. 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Copyright (c) 2003-2005 The Regents of The University of Michigan 15 * All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions are 19 * met: redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer; 21 * redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution; 24 * neither the name of the copyright holders nor the names of its 25 * contributors may be used to endorse or promote products derived from 26 * this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 39 * 40 * Authors: Erik Hallnor 41 * Ron Dreslinski 42 */ 43 44/** 45 * @file 46 * Declaration of a common base class for cache tagstore objects. 47 */ 48 49#ifndef __MEM_CACHE_TAGS_BASE_HH__ 50#define __MEM_CACHE_TAGS_BASE_HH__ 51 52#include <cassert> 53#include <cstdint> 54#include <functional> 55#include <string> 56 57#include "base/callback.hh" 58#include "base/logging.hh" 59#include "base/statistics.hh" 60#include "base/types.hh" 61#include "mem/cache/cache_blk.hh" 62#include "mem/packet.hh" 63#include "params/BaseTags.hh" 64#include "sim/clocked_object.hh" 65 66class System; 67class IndexingPolicy; 68class ReplaceableEntry; 69 70/** 71 * A common base class of Cache tagstore objects. 72 */ 73class BaseTags : public ClockedObject 74{ 75 protected: 76 /** The block size of the cache. */ 77 const unsigned blkSize; 78 /** Mask out all bits that aren't part of the block offset. */ 79 const Addr blkMask; 80 /** The size of the cache. */ 81 const unsigned size; 82 /** The tag lookup latency of the cache. */ 83 const Cycles lookupLatency; 84 85 /** System we are currently operating in. */ 86 System *system; 87 88 /** Indexing policy */ 89 BaseIndexingPolicy *indexingPolicy; 90 91 /** 92 * The number of tags that need to be touched to meet the warmup 93 * percentage. 94 */ 95 const unsigned warmupBound; 96 /** Marked true when the cache is warmed up. */ 97 bool warmedUp; 98 99 /** the number of blocks in the cache */ 100 const unsigned numBlocks; 101 102 /** The data blocks, 1 per cache block. */ 103 std::unique_ptr<uint8_t[]> dataBlks; 104 105 // Statistics 106 /** 107 * TODO: It would be good if these stats were acquired after warmup. 108 * @addtogroup CacheStatistics 109 * @{ 110 */ 111 112 /** Per cycle average of the number of tags that hold valid data. */ 113 Stats::Average tagsInUse; 114 115 /** The total number of references to a block before it is replaced. */ 116 Stats::Scalar totalRefs; 117 118 /** 119 * The number of reference counts sampled. This is different from 120 * replacements because we sample all the valid blocks when the simulator 121 * exits. 122 */ 123 Stats::Scalar sampledRefs; 124 125 /** 126 * Average number of references to a block before is was replaced. 127 * @todo This should change to an average stat once we have them. 128 */ 129 Stats::Formula avgRefs; 130 131 /** The cycle that the warmup percentage was hit. 0 on failure. */ 132 Stats::Scalar warmupCycle; 133 134 /** Average occupancy of each requestor using the cache */ 135 Stats::AverageVector occupancies; 136 137 /** Average occ % of each requestor using the cache */ 138 Stats::Formula avgOccs; 139 140 /** Occupancy of each context/cpu using the cache */ 141 Stats::Vector occupanciesTaskId; 142 143 /** Occupancy of each context/cpu using the cache */ 144 Stats::Vector2d ageTaskId; 145 146 /** Occ % of each context/cpu using the cache */ 147 Stats::Formula percentOccsTaskId; 148 149 /** Number of tags consulted over all accesses. */ 150 Stats::Scalar tagAccesses; 151 /** Number of data blocks consulted over all accesses. */ 152 Stats::Scalar dataAccesses; 153 154 /** 155 * @} 156 */ 157 158 public: 159 typedef BaseTagsParams Params; 160 BaseTags(const Params *p); 161 162 /** 163 * Destructor. 164 */ 165 virtual ~BaseTags() {} 166 167 /** 168 * Initialize blocks. Must be overriden by every subclass that uses 169 * a block type different from its parent's, as the current Python 170 * code generation does not allow templates. 171 */ 172 virtual void tagsInit() = 0; 173 174 /** 175 * Register local statistics. 176 */ 177 void regStats(); 178 179 /** 180 * Average in the reference count for valid blocks when the simulation 181 * exits. 182 */ 183 void cleanupRefs(); 184 185 /** 186 * Computes stats just prior to dump event 187 */ 188 void computeStats(); 189 190 /** 191 * Print all tags used 192 */ 193 std::string print(); 194 195 /** 196 * Finds the block in the cache without touching it. 197 * 198 * @param addr The address to look for. 199 * @param is_secure True if the target memory space is secure. 200 * @return Pointer to the cache block. 201 */ 202 virtual CacheBlk *findBlock(Addr addr, bool is_secure) const; 203 204 /** 205 * Find a block given set and way. 206 * 207 * @param set The set of the block. 208 * @param way The way of the block. 209 * @return The block. 210 */ 211 virtual ReplaceableEntry* findBlockBySetAndWay(int set, int way) const; 212 213 /** 214 * Align an address to the block size. 215 * @param addr the address to align. 216 * @return The block address. 217 */ 218 Addr blkAlign(Addr addr) const 219 { 220 return addr & ~blkMask; 221 } 222 223 /** 224 * Calculate the block offset of an address. 225 * @param addr the address to get the offset of. 226 * @return the block offset. 227 */ 228 int extractBlkOffset(Addr addr) const 229 { 230 return (addr & blkMask); 231 } 232 233 /** 234 * Limit the allocation for the cache ways. 235 * @param ways The maximum number of ways available for replacement. 236 */ 237 virtual void setWayAllocationMax(int ways) 238 { 239 panic("This tag class does not implement way allocation limit!\n"); 240 } 241 242 /** 243 * Get the way allocation mask limit. 244 * @return The maximum number of ways available for replacement. 245 */ 246 virtual int getWayAllocationMax() const 247 { 248 panic("This tag class does not implement way allocation limit!\n"); 249 return -1; 250 } 251 252 /** 253 * This function updates the tags when a block is invalidated 254 * 255 * @param blk A valid block to invalidate. 256 */ 257 virtual void invalidate(CacheBlk *blk) 258 { 259 assert(blk); 260 assert(blk->isValid()); 261 262 occupancies[blk->srcMasterId]--; 263 totalRefs += blk->refCount; 264 sampledRefs++; 265 266 blk->invalidate(); 267 } 268 269 /** 270 * Find replacement victim based on address. If the address requires 271 * blocks to be evicted, their locations are listed for eviction. If a 272 * conventional cache is being used, the list only contains the victim. 273 * However, if using sector or compressed caches, the victim is one of 274 * the blocks to be evicted, but its location is the only one that will 275 * be assigned to the newly allocated block associated to this address. 276 * @sa insertBlock 277 * 278 * @param addr Address to find a victim for. 279 * @param is_secure True if the target memory space is secure. 280 * @param size Size, in bits, of new block to allocate. 281 * @param evict_blks Cache blocks to be evicted. 282 * @return Cache block to be replaced. 283 */ 284 virtual CacheBlk* findVictim(Addr addr, const bool is_secure, 285 const std::size_t size, 286 std::vector<CacheBlk*>& evict_blks) const = 0; 287 288 /** 289 * Access block and update replacement data. May not succeed, in which case 290 * nullptr is returned. This has all the implications of a cache access and 291 * should only be used as such. Returns the tag lookup latency as a side 292 * effect. 293 * 294 * @param addr The address to find. 295 * @param is_secure True if the target memory space is secure. 296 * @param lat The latency of the tag lookup. 297 * @return Pointer to the cache block if found. 298 */ 299 virtual CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) = 0; 300 301 /** 302 * Generate the tag from the given address. 303 * 304 * @param addr The address to get the tag from. 305 * @return The tag of the address. 306 */ 307 virtual Addr extractTag(const Addr addr) const; 308 309 /** 310 * Insert the new block into the cache and update stats. 311 * 312 * @param pkt Packet holding the address to update 313 * @param blk The block to update. 314 */ 315 virtual void insertBlock(const PacketPtr pkt, CacheBlk *blk); 316 317 /** 318 * Regenerate the block address. 319 * 320 * @param block The block. 321 * @return the block address. 322 */ 323 virtual Addr regenerateBlkAddr(const CacheBlk* blk) const = 0; 324 325 /** 326 * Visit each block in the tags and apply a visitor 327 * 328 * The visitor should be a std::function that takes a cache block 329 * reference as its parameter. 330 * 331 * @param visitor Visitor to call on each block. 332 */ 333 virtual void forEachBlk(std::function<void(CacheBlk &)> visitor) = 0; 334 335 /** 336 * Find if any of the blocks satisfies a condition 337 * 338 * The visitor should be a std::function that takes a cache block 339 * reference as its parameter. The visitor will terminate the 340 * traversal early if the condition is satisfied. 341 * 342 * @param visitor Visitor to call on each block. 343 */ 344 virtual bool anyBlk(std::function<bool(CacheBlk &)> visitor) = 0; 345 346 private: 347 /** 348 * Update the reference stats using data from the input block 349 * 350 * @param blk The input block 351 */ 352 void cleanupRefsVisitor(CacheBlk &blk); 353 354 /** 355 * Update the occupancy and age stats using data from the input block 356 * 357 * @param blk The input block 358 */ 359 void computeStatsVisitor(CacheBlk &blk); 360}; 361 362class BaseTagsCallback : public Callback 363{ 364 BaseTags *tags; 365 public: 366 BaseTagsCallback(BaseTags *t) : tags(t) {} 367 virtual void process() { tags->cleanupRefs(); }; 368}; 369 370class BaseTagsDumpCallback : public Callback 371{ 372 BaseTags *tags; 373 public: 374 BaseTagsDumpCallback(BaseTags *t) : tags(t) {} 375 virtual void process() { tags->computeStats(); }; 376}; 377 378#endif //__MEM_CACHE_TAGS_BASE_HH__ 379