1/* 2 * Copyright (c) 2018 Inria 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: Daniel Carvalho 29 */ 30 31/** 32 * @file 33 * Declaration of a sector tag store. 34 */ 35 36#ifndef __MEM_CACHE_TAGS_SECTOR_TAGS_HH__ 37#define __MEM_CACHE_TAGS_SECTOR_TAGS_HH__ 38 39#include <string> 40#include <vector> 41 42#include "mem/cache/tags/base.hh" 43#include "mem/cache/tags/sector_blk.hh" 44#include "params/SectorTags.hh" 45 46class BaseCache; 47class BaseReplacementPolicy; 48class ReplaceableEntry; 49 50/** 51 * A SectorTags cache tag store. 52 * @sa \ref gem5MemorySystem "gem5 Memory System" 53 * 54 * The SectorTags placement policy divides the cache into s sectors of w 55 * consecutive sectors (ways). Each sector then consists of a number of 56 * sequential cache lines that may or may not be present. 57 */ 58class SectorTags : public BaseTags 59{ 60 protected: 61 /** The allocatable associativity of the cache (alloc mask). */ 62 unsigned allocAssoc; 63 64 /** Whether tags and data are accessed sequentially. */ 65 const bool sequentialAccess; 66 67 /** Replacement policy */ 68 BaseReplacementPolicy *replacementPolicy; 69 70 /** Number of data blocks per sector. */ 71 const unsigned numBlocksPerSector; 72 73 /** The number of sectors in the cache. */ 74 const unsigned numSectors; 75 76 /** The cache blocks. */ 77 std::vector<SectorSubBlk> blks; 78 /** The cache sector blocks. */ 79 std::vector<SectorBlk> secBlks; 80 81 // Organization of an address: 82 // Tag | Placement Location | Sector Offset # | Offset # 83 /** The amount to shift the address to get the sector tag. */ 84 const int sectorShift; 85 86 /** Mask out all bits that aren't part of the sector tag. */ 87 const unsigned sectorMask; 88 89 public: 90 /** Convenience typedef. */ 91 typedef SectorTagsParams Params; 92 93 /** 94 * Construct and initialize this tag store. 95 */ 96 SectorTags(const Params *p); 97 98 /** 99 * Destructor. 100 */ 101 virtual ~SectorTags() {}; 102 103 /**
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104 * Initialize blocks and set the parent cache back pointer.
105 *
106 * @param _cache Pointer to parent cache.
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104 * Initialize blocks as SectorBlk and SectorSubBlk instances. |
105 */
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108 void tagsInit(BaseCache *_cache) override;
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106 void tagsInit() override; |
107 108 /** 109 * This function updates the tags when a block is invalidated but does 110 * not invalidate the block itself. It also updates the replacement data. 111 * 112 * @param blk The block to invalidate. 113 */ 114 void invalidate(CacheBlk *blk) override; 115 116 /** 117 * Access block and update replacement data. May not succeed, in which 118 * case nullptr is returned. This has all the implications of a cache 119 * access and should only be used as such. Returns the tag lookup latency 120 * as a side effect. 121 * 122 * @param addr The address to find. 123 * @param is_secure True if the target memory space is secure. 124 * @param lat The latency of the tag lookup. 125 * @return Pointer to the cache block if found. 126 */ 127 CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) override; 128 129 /** 130 * Insert the new block into the cache and update replacement data. 131 * 132 * @param addr Address of the block. 133 * @param is_secure Whether the block is in secure space or not. 134 * @param src_master_ID The source requestor ID. 135 * @param task_ID The new task ID. 136 * @param blk The block to update. 137 */ 138 void insertBlock(const Addr addr, const bool is_secure, 139 const int src_master_ID, const uint32_t task_ID, 140 CacheBlk *blk) override; 141 142 /** 143 * Finds the given address in the cache, do not update replacement data. 144 * i.e. This is a no-side-effect find of a block. 145 * 146 * @param addr The address to find. 147 * @param is_secure True if the target memory space is secure. 148 * @return Pointer to the cache block if found. 149 */ 150 CacheBlk* findBlock(Addr addr, bool is_secure) const override; 151 152 /** 153 * Find replacement victim based on address. 154 * 155 * @param addr Address to find a victim for. 156 * @param is_secure True if the target memory space is secure. 157 * @param evict_blks Cache blocks to be evicted. 158 * @return Cache block to be replaced. 159 */ 160 CacheBlk* findVictim(Addr addr, const bool is_secure, 161 std::vector<CacheBlk*>& evict_blks) const override; 162 163 /** 164 * Calculate a block's offset in a sector from the address. 165 * 166 * @param addr The address to get the offset from. 167 * @return Offset of the corresponding block within its sector. 168 */ 169 int extractSectorOffset(Addr addr) const; 170 171 /** 172 * Regenerate the block address from the tag and location. 173 * 174 * @param block The block. 175 * @return the block address. 176 */ 177 Addr regenerateBlkAddr(const CacheBlk* blk) const override; 178 179 /** 180 * Visit each sub-block in the tags and apply a visitor. 181 * 182 * The visitor should be a std::function that takes a cache block. 183 * reference as its parameter. 184 * 185 * @param visitor Visitor to call on each block. 186 */ 187 void forEachBlk(std::function<void(CacheBlk &)> visitor) override; 188 189 /** 190 * Find if any of the sub-blocks satisfies a condition. 191 * 192 * The visitor should be a std::function that takes a cache block 193 * reference as its parameter. The visitor will terminate the 194 * traversal early if the condition is satisfied. 195 * 196 * @param visitor Visitor to call on each block. 197 */ 198 bool anyBlk(std::function<bool(CacheBlk &)> visitor) override; 199}; 200 201#endif //__MEM_CACHE_TAGS_SECTOR_TAGS_HH__
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