base.hh revision 13217:725b1701b4ee
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 <functional> 54#include <string> 55 56#include "base/callback.hh" 57#include "base/logging.hh" 58#include "base/statistics.hh" 59#include "base/types.hh" 60#include "mem/cache/blk.hh" 61#include "params/BaseTags.hh" 62#include "sim/clocked_object.hh" 63 64class BaseCache; 65class ReplaceableEntry; 66 67/** 68 * A common base class of Cache tagstore objects. 69 */ 70class BaseTags : public ClockedObject 71{ 72 protected: 73 /** The block size of the cache. */ 74 const unsigned blkSize; 75 /** Mask out all bits that aren't part of the block offset. */ 76 const Addr blkMask; 77 /** The size of the cache. */ 78 const unsigned size; 79 /** The tag lookup latency of the cache. */ 80 const Cycles lookupLatency; 81 /** 82 * The total access latency of the cache. This latency 83 * is different depending on the cache access mode 84 * (parallel or sequential) 85 */ 86 const Cycles accessLatency; 87 /** Pointer to the parent cache. */ 88 BaseCache *cache; 89 90 /** 91 * The number of tags that need to be touched to meet the warmup 92 * percentage. 93 */ 94 const unsigned warmupBound; 95 /** Marked true when the cache is warmed up. */ 96 bool warmedUp; 97 98 /** the number of blocks in the cache */ 99 const unsigned numBlocks; 100 101 /** The data blocks, 1 per cache block. */ 102 std::unique_ptr<uint8_t[]> dataBlks; 103 104 // Statistics 105 /** 106 * TODO: It would be good if these stats were acquired after warmup. 107 * @addtogroup CacheStatistics 108 * @{ 109 */ 110 111 /** Per cycle average of the number of tags that hold valid data. */ 112 Stats::Average tagsInUse; 113 114 /** The total number of references to a block before it is replaced. */ 115 Stats::Scalar totalRefs; 116 117 /** 118 * The number of reference counts sampled. This is different from 119 * replacements because we sample all the valid blocks when the simulator 120 * exits. 121 */ 122 Stats::Scalar sampledRefs; 123 124 /** 125 * Average number of references to a block before is was replaced. 126 * @todo This should change to an average stat once we have them. 127 */ 128 Stats::Formula avgRefs; 129 130 /** The cycle that the warmup percentage was hit. 0 on failure. */ 131 Stats::Scalar warmupCycle; 132 133 /** Average occupancy of each requestor using the cache */ 134 Stats::AverageVector occupancies; 135 136 /** Average occ % of each requestor using the cache */ 137 Stats::Formula avgOccs; 138 139 /** Occupancy of each context/cpu using the cache */ 140 Stats::Vector occupanciesTaskId; 141 142 /** Occupancy of each context/cpu using the cache */ 143 Stats::Vector2d ageTaskId; 144 145 /** Occ % of each context/cpu using the cache */ 146 Stats::Formula percentOccsTaskId; 147 148 /** Number of tags consulted over all accesses. */ 149 Stats::Scalar tagAccesses; 150 /** Number of data blocks consulted over all accesses. */ 151 Stats::Scalar dataAccesses; 152 153 /** 154 * @} 155 */ 156 157 /** 158 * Set the parent cache back pointer. 159 * 160 * @param _cache Pointer to parent cache. 161 */ 162 void setCache(BaseCache *_cache); 163 164 /** 165 * Find all possible block locations for insertion and replacement of 166 * an address. Should be called immediately before ReplacementPolicy's 167 * findVictim() not to break cache resizing. 168 * Returns blocks in all ways belonging to the set of the address. 169 * 170 * @param addr The addr to a find possible locations for. 171 * @return The possible locations. 172 */ 173 virtual std::vector<ReplaceableEntry*> getPossibleLocations( 174 const Addr addr) const; 175 176 public: 177 typedef BaseTagsParams Params; 178 BaseTags(const Params *p); 179 180 /** 181 * Destructor. 182 */ 183 virtual ~BaseTags() {} 184 185 /** 186 * Initialize blocks and set the parent cache back pointer. 187 * 188 * @param _cache Pointer to parent cache. 189 */ 190 virtual void init(BaseCache *_cache) = 0; 191 192 /** 193 * Register local statistics. 194 */ 195 void regStats(); 196 197 /** 198 * Average in the reference count for valid blocks when the simulation 199 * exits. 200 */ 201 void cleanupRefs(); 202 203 /** 204 * Computes stats just prior to dump event 205 */ 206 void computeStats(); 207 208 /** 209 * Print all tags used 210 */ 211 std::string print(); 212 213 /** 214 * Finds the block in the cache without touching it. 215 * 216 * @param addr The address to look for. 217 * @param is_secure True if the target memory space is secure. 218 * @return Pointer to the cache block. 219 */ 220 virtual CacheBlk *findBlock(Addr addr, bool is_secure) const; 221 222 /** 223 * Find a block given set and way. 224 * 225 * @param set The set of the block. 226 * @param way The way of the block. 227 * @return The block. 228 */ 229 virtual ReplaceableEntry* findBlockBySetAndWay(int set, int way) const = 0; 230 231 /** 232 * Align an address to the block size. 233 * @param addr the address to align. 234 * @return The block address. 235 */ 236 Addr blkAlign(Addr addr) const 237 { 238 return addr & ~blkMask; 239 } 240 241 /** 242 * Calculate the block offset of an address. 243 * @param addr the address to get the offset of. 244 * @return the block offset. 245 */ 246 int extractBlkOffset(Addr addr) const 247 { 248 return (addr & blkMask); 249 } 250 251 /** 252 * Limit the allocation for the cache ways. 253 * @param ways The maximum number of ways available for replacement. 254 */ 255 virtual void setWayAllocationMax(int ways) 256 { 257 panic("This tag class does not implement way allocation limit!\n"); 258 } 259 260 /** 261 * Get the way allocation mask limit. 262 * @return The maximum number of ways available for replacement. 263 */ 264 virtual int getWayAllocationMax() const 265 { 266 panic("This tag class does not implement way allocation limit!\n"); 267 return -1; 268 } 269 270 /** 271 * This function updates the tags when a block is invalidated 272 * 273 * @param blk A valid block to invalidate. 274 */ 275 virtual void invalidate(CacheBlk *blk) 276 { 277 assert(blk); 278 assert(blk->isValid()); 279 280 occupancies[blk->srcMasterId]--; 281 totalRefs += blk->refCount; 282 sampledRefs++; 283 284 blk->invalidate(); 285 } 286 287 /** 288 * Find replacement victim based on address. If the address requires 289 * blocks to be evicted, their locations are listed for eviction. If a 290 * conventional cache is being used, the list only contains the victim. 291 * However, if using sector or compressed caches, the victim is one of 292 * the blocks to be evicted, but its location is the only one that will 293 * be assigned to the newly allocated block associated to this address. 294 * @sa insertBlock 295 * 296 * @param addr Address to find a victim for. 297 * @param is_secure True if the target memory space is secure. 298 * @param evict_blks Cache blocks to be evicted. 299 * @return Cache block to be replaced. 300 */ 301 virtual CacheBlk* findVictim(Addr addr, const bool is_secure, 302 std::vector<CacheBlk*>& evict_blks) const = 0; 303 304 virtual CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) = 0; 305 306 virtual Addr extractTag(Addr addr) const = 0; 307 308 /** 309 * Insert the new block into the cache and update stats. 310 * 311 * @param addr Address of the block. 312 * @param is_secure Whether the block is in secure space or not. 313 * @param src_master_ID The source requestor ID. 314 * @param task_ID The new task ID. 315 * @param blk The block to update. 316 */ 317 virtual void insertBlock(const Addr addr, const bool is_secure, 318 const int src_master_ID, const uint32_t task_ID, 319 CacheBlk *blk); 320 321 /** 322 * Regenerate the block address. 323 * 324 * @param block The block. 325 * @return the block address. 326 */ 327 virtual Addr regenerateBlkAddr(const CacheBlk* blk) const = 0; 328 329 /** 330 * Visit each block in the tags and apply a visitor 331 * 332 * The visitor should be a std::function that takes a cache block 333 * reference as its parameter. 334 * 335 * @param visitor Visitor to call on each block. 336 */ 337 virtual void forEachBlk(std::function<void(CacheBlk &)> visitor) = 0; 338 339 /** 340 * Find if any of the blocks satisfies a condition 341 * 342 * The visitor should be a std::function that takes a cache block 343 * reference as its parameter. The visitor will terminate the 344 * traversal early if the condition is satisfied. 345 * 346 * @param visitor Visitor to call on each block. 347 */ 348 virtual bool anyBlk(std::function<bool(CacheBlk &)> visitor) = 0; 349 350 private: 351 /** 352 * Update the reference stats using data from the input block 353 * 354 * @param blk The input block 355 */ 356 void cleanupRefsVisitor(CacheBlk &blk); 357 358 /** 359 * Update the occupancy and age stats using data from the input block 360 * 361 * @param blk The input block 362 */ 363 void computeStatsVisitor(CacheBlk &blk); 364}; 365 366class BaseTagsCallback : public Callback 367{ 368 BaseTags *tags; 369 public: 370 BaseTagsCallback(BaseTags *t) : tags(t) {} 371 virtual void process() { tags->cleanupRefs(); }; 372}; 373 374class BaseTagsDumpCallback : public Callback 375{ 376 BaseTags *tags; 377 public: 378 BaseTagsDumpCallback(BaseTags *t) : tags(t) {} 379 virtual void process() { tags->computeStats(); }; 380}; 381 382#endif //__MEM_CACHE_TAGS_BASE_HH__ 383