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