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 /** 104 * Initialize blocks and set the parent cache back pointer. 105 * 106 * @param _cache Pointer to parent cache. 107 */ 108 void tagsInit(BaseCache *_cache) override; 109 110 /** 111 * This function updates the tags when a block is invalidated but does 112 * not invalidate the block itself. It also updates the replacement data. 113 * 114 * @param blk The block to invalidate. 115 */ 116 void invalidate(CacheBlk *blk) override; 117 118 /** 119 * Access block and update replacement data. May not succeed, in which 120 * case nullptr is returned. This has all the implications of a cache
|
121 * access and should only be used as such. Returns the access latency
|
121 * access and should only be used as such. Returns the tag lookup latency |
122 * as a side effect. 123 * 124 * @param addr The address to find. 125 * @param is_secure True if the target memory space is secure.
|
126 * @param lat The access latency.
|
126 * @param lat The latency of the tag lookup. |
127 * @return Pointer to the cache block if found. 128 */ 129 CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) override; 130 131 /** 132 * Insert the new block into the cache and update replacement data. 133 * 134 * @param addr Address of the block. 135 * @param is_secure Whether the block is in secure space or not. 136 * @param src_master_ID The source requestor ID. 137 * @param task_ID The new task ID. 138 * @param blk The block to update. 139 */ 140 void insertBlock(const Addr addr, const bool is_secure, 141 const int src_master_ID, const uint32_t task_ID, 142 CacheBlk *blk) override; 143 144 /** 145 * Finds the given address in the cache, do not update replacement data. 146 * i.e. This is a no-side-effect find of a block. 147 * 148 * @param addr The address to find. 149 * @param is_secure True if the target memory space is secure. 150 * @return Pointer to the cache block if found. 151 */ 152 CacheBlk* findBlock(Addr addr, bool is_secure) const override; 153 154 /** 155 * Find replacement victim based on address. 156 * 157 * @param addr Address to find a victim for. 158 * @param is_secure True if the target memory space is secure. 159 * @param evict_blks Cache blocks to be evicted. 160 * @return Cache block to be replaced. 161 */ 162 CacheBlk* findVictim(Addr addr, const bool is_secure, 163 std::vector<CacheBlk*>& evict_blks) const override; 164 165 /** 166 * Calculate a block's offset in a sector from the address. 167 * 168 * @param addr The address to get the offset from. 169 * @return Offset of the corresponding block within its sector. 170 */ 171 int extractSectorOffset(Addr addr) const; 172 173 /** 174 * Regenerate the block address from the tag and location. 175 * 176 * @param block The block. 177 * @return the block address. 178 */ 179 Addr regenerateBlkAddr(const CacheBlk* blk) const override; 180 181 /** 182 * Visit each sub-block in the tags and apply a visitor. 183 * 184 * The visitor should be a std::function that takes a cache block. 185 * reference as its parameter. 186 * 187 * @param visitor Visitor to call on each block. 188 */ 189 void forEachBlk(std::function<void(CacheBlk &)> visitor) override; 190 191 /** 192 * Find if any of the sub-blocks satisfies a condition. 193 * 194 * The visitor should be a std::function that takes a cache block 195 * reference as its parameter. The visitor will terminate the 196 * traversal early if the condition is satisfied. 197 * 198 * @param visitor Visitor to call on each block. 199 */ 200 bool anyBlk(std::function<bool(CacheBlk &)> visitor) override; 201}; 202 203#endif //__MEM_CACHE_TAGS_SECTOR_TAGS_HH__
|