| /* |
| * Copyright (c) 2018 Inria |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer; |
| * redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution; |
| * neither the name of the copyright holders nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** |
| * @file |
| * Declaration of a sector tag store. |
| */ |
| |
| #ifndef __MEM_CACHE_TAGS_SECTOR_TAGS_HH__ |
| #define __MEM_CACHE_TAGS_SECTOR_TAGS_HH__ |
| |
| #include <cstdint> |
| #include <string> |
| #include <vector> |
| |
| #include "base/statistics.hh" |
| #include "mem/cache/tags/base.hh" |
| #include "mem/cache/tags/sector_blk.hh" |
| #include "mem/packet.hh" |
| #include "params/SectorTags.hh" |
| |
| class BaseReplacementPolicy; |
| class ReplaceableEntry; |
| |
| /** |
| * A SectorTags cache tag store. |
| * @sa \ref gem5MemorySystem "gem5 Memory System" |
| * |
| * The SectorTags placement policy divides the cache into s sectors of w |
| * consecutive sectors (ways). Each sector then consists of a number of |
| * sequential cache lines that may or may not be present. |
| */ |
| class SectorTags : public BaseTags |
| { |
| private: |
| /** The cache blocks. */ |
| std::vector<SectorSubBlk> blks; |
| /** The cache sector blocks. */ |
| std::vector<SectorBlk> secBlks; |
| |
| protected: |
| /** The allocatable associativity of the cache (alloc mask). */ |
| unsigned allocAssoc; |
| |
| /** Whether tags and data are accessed sequentially. */ |
| const bool sequentialAccess; |
| |
| /** Replacement policy */ |
| BaseReplacementPolicy *replacementPolicy; |
| |
| /** Number of data blocks per sector. */ |
| const unsigned numBlocksPerSector; |
| |
| /** The number of sectors in the cache. */ |
| const unsigned numSectors; |
| |
| // Organization of an address: |
| // Tag | Placement Location | Sector Offset # | Offset # |
| /** The amount to shift the address to get the sector tag. */ |
| const int sectorShift; |
| |
| /** Mask out all bits that aren't part of the sector tag. */ |
| const unsigned sectorMask; |
| |
| struct SectorTagsStats : public Stats::Group |
| { |
| const SectorTags& tags; |
| |
| SectorTagsStats(BaseTagStats &base_group, SectorTags& _tags); |
| |
| void regStats() override; |
| |
| /** Number of sub-blocks evicted due to a replacement. */ |
| Stats::Vector evictionsReplacement; |
| } sectorStats; |
| |
| public: |
| /** Convenience typedef. */ |
| typedef SectorTagsParams Params; |
| |
| /** |
| * Construct and initialize this tag store. |
| */ |
| SectorTags(const Params *p); |
| |
| /** |
| * Destructor. |
| */ |
| virtual ~SectorTags() {}; |
| |
| /** |
| * Initialize blocks as SectorBlk and SectorSubBlk instances. |
| */ |
| void tagsInit() override; |
| |
| /** |
| * This function updates the tags when a block is invalidated but does |
| * not invalidate the block itself. It also updates the replacement data. |
| * |
| * @param blk The block to invalidate. |
| */ |
| void invalidate(CacheBlk *blk) override; |
| |
| /** |
| * Access block and update replacement data. May not succeed, in which |
| * case nullptr is returned. This has all the implications of a cache |
| * access and should only be used as such. Returns the tag lookup latency |
| * as a side effect. |
| * |
| * @param addr The address to find. |
| * @param is_secure True if the target memory space is secure. |
| * @param lat The latency of the tag lookup. |
| * @return Pointer to the cache block if found. |
| */ |
| CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) override; |
| |
| /** |
| * Insert the new block into the cache and update replacement data. |
| * |
| * @param pkt Packet holding the address to update |
| * @param blk The block to update. |
| */ |
| void insertBlock(const PacketPtr pkt, CacheBlk *blk) override; |
| |
| /** |
| * Finds the given address in the cache, do not update replacement data. |
| * i.e. This is a no-side-effect find of a block. |
| * |
| * @param addr The address to find. |
| * @param is_secure True if the target memory space is secure. |
| * @return Pointer to the cache block if found. |
| */ |
| CacheBlk* findBlock(Addr addr, bool is_secure) const override; |
| |
| /** |
| * Find replacement victim based on address. |
| * |
| * @param addr Address to find a victim for. |
| * @param is_secure True if the target memory space is secure. |
| * @param size Size, in bits, of new block to allocate. |
| * @param evict_blks Cache blocks to be evicted. |
| * @return Cache block to be replaced. |
| */ |
| CacheBlk* findVictim(Addr addr, const bool is_secure, |
| const std::size_t size, |
| std::vector<CacheBlk*>& evict_blks) override; |
| |
| /** |
| * Calculate a block's offset in a sector from the address. |
| * |
| * @param addr The address to get the offset from. |
| * @return Offset of the corresponding block within its sector. |
| */ |
| int extractSectorOffset(Addr addr) const; |
| |
| /** |
| * Regenerate the block address from the tag and location. |
| * |
| * @param block The block. |
| * @return the block address. |
| */ |
| Addr regenerateBlkAddr(const CacheBlk* blk) const override; |
| |
| /** |
| * Visit each sub-block in the tags and apply a visitor. |
| * |
| * The visitor should be a std::function that takes a cache block. |
| * reference as its parameter. |
| * |
| * @param visitor Visitor to call on each block. |
| */ |
| void forEachBlk(std::function<void(CacheBlk &)> visitor) override; |
| |
| /** |
| * Find if any of the sub-blocks satisfies a condition. |
| * |
| * The visitor should be a std::function that takes a cache block |
| * reference as its parameter. The visitor will terminate the |
| * traversal early if the condition is satisfied. |
| * |
| * @param visitor Visitor to call on each block. |
| */ |
| bool anyBlk(std::function<bool(CacheBlk &)> visitor) override; |
| }; |
| |
| #endif //__MEM_CACHE_TAGS_SECTOR_TAGS_HH__ |