| /* |
| * Copyright (c) 2012-2014,2016-2019 ARM Limited |
| * All rights reserved. |
| * |
| * The license below extends only to copyright in the software and shall |
| * not be construed as granting a license to any other intellectual |
| * property including but not limited to intellectual property relating |
| * to a hardware implementation of the functionality of the software |
| * licensed hereunder. You may use the software subject to the license |
| * terms below provided that you ensure that this notice is replicated |
| * unmodified and in its entirety in all distributions of the software, |
| * modified or unmodified, in source code or in binary form. |
| * |
| * Copyright (c) 2003-2005 The Regents of The University of Michigan |
| * 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 common base class for cache tagstore objects. |
| */ |
| |
| #ifndef __MEM_CACHE_TAGS_BASE_HH__ |
| #define __MEM_CACHE_TAGS_BASE_HH__ |
| |
| #include <cassert> |
| #include <cstdint> |
| #include <functional> |
| #include <string> |
| |
| #include "base/callback.hh" |
| #include "base/logging.hh" |
| #include "base/statistics.hh" |
| #include "base/types.hh" |
| #include "mem/cache/cache_blk.hh" |
| #include "mem/packet.hh" |
| #include "params/BaseTags.hh" |
| #include "sim/clocked_object.hh" |
| |
| class System; |
| class IndexingPolicy; |
| class ReplaceableEntry; |
| |
| /** |
| * A common base class of Cache tagstore objects. |
| */ |
| class BaseTags : public ClockedObject |
| { |
| protected: |
| /** The block size of the cache. */ |
| const unsigned blkSize; |
| /** Mask out all bits that aren't part of the block offset. */ |
| const Addr blkMask; |
| /** The size of the cache. */ |
| const unsigned size; |
| /** The tag lookup latency of the cache. */ |
| const Cycles lookupLatency; |
| |
| /** System we are currently operating in. */ |
| System *system; |
| |
| /** Indexing policy */ |
| BaseIndexingPolicy *indexingPolicy; |
| |
| /** |
| * The number of tags that need to be touched to meet the warmup |
| * percentage. |
| */ |
| const unsigned warmupBound; |
| /** Marked true when the cache is warmed up. */ |
| bool warmedUp; |
| |
| /** the number of blocks in the cache */ |
| const unsigned numBlocks; |
| |
| /** The data blocks, 1 per cache block. */ |
| std::unique_ptr<uint8_t[]> dataBlks; |
| |
| /** |
| * TODO: It would be good if these stats were acquired after warmup. |
| */ |
| struct BaseTagStats : public Stats::Group |
| { |
| BaseTagStats(BaseTags &tags); |
| |
| void regStats() override; |
| void preDumpStats() override; |
| |
| BaseTags &tags; |
| |
| /** Per tick average of the number of tags that hold valid data. */ |
| Stats::Average tagsInUse; |
| |
| /** The total number of references to a block before it is replaced. */ |
| Stats::Scalar totalRefs; |
| |
| /** |
| * The number of reference counts sampled. This is different |
| * from replacements because we sample all the valid blocks |
| * when the simulator exits. |
| */ |
| Stats::Scalar sampledRefs; |
| |
| /** |
| * Average number of references to a block before is was replaced. |
| * @todo This should change to an average stat once we have them. |
| */ |
| Stats::Formula avgRefs; |
| |
| /** The tick that the warmup percentage was hit. 0 on failure. */ |
| Stats::Scalar warmupTick; |
| |
| /** Average occupancy of each requestor using the cache */ |
| Stats::AverageVector occupancies; |
| |
| /** Average occ % of each requestor using the cache */ |
| Stats::Formula avgOccs; |
| |
| /** Occupancy of each context/cpu using the cache */ |
| Stats::Vector occupanciesTaskId; |
| |
| /** Occupancy of each context/cpu using the cache */ |
| Stats::Vector2d ageTaskId; |
| |
| /** Occ ratio of each context/cpu using the cache */ |
| Stats::Formula ratioOccsTaskId; |
| |
| /** Number of tags consulted over all accesses. */ |
| Stats::Scalar tagAccesses; |
| /** Number of data blocks consulted over all accesses. */ |
| Stats::Scalar dataAccesses; |
| } stats; |
| |
| public: |
| typedef BaseTagsParams Params; |
| BaseTags(const Params &p); |
| |
| /** |
| * Destructor. |
| */ |
| virtual ~BaseTags() {} |
| |
| /** |
| * Initialize blocks. Must be overriden by every subclass that uses |
| * a block type different from its parent's, as the current Python |
| * code generation does not allow templates. |
| */ |
| virtual void tagsInit() = 0; |
| |
| /** |
| * Average in the reference count for valid blocks when the simulation |
| * exits. |
| */ |
| void cleanupRefs(); |
| |
| /** |
| * Computes stats just prior to dump event |
| */ |
| void computeStats(); |
| |
| /** |
| * Print all tags used |
| */ |
| std::string print(); |
| |
| /** |
| * Finds the block in the cache without touching it. |
| * |
| * @param addr The address to look for. |
| * @param is_secure True if the target memory space is secure. |
| * @return Pointer to the cache block. |
| */ |
| virtual CacheBlk *findBlock(Addr addr, bool is_secure) const; |
| |
| /** |
| * Find a block given set and way. |
| * |
| * @param set The set of the block. |
| * @param way The way of the block. |
| * @return The block. |
| */ |
| virtual ReplaceableEntry* findBlockBySetAndWay(int set, int way) const; |
| |
| /** |
| * Align an address to the block size. |
| * @param addr the address to align. |
| * @return The block address. |
| */ |
| Addr blkAlign(Addr addr) const |
| { |
| return addr & ~blkMask; |
| } |
| |
| /** |
| * Calculate the block offset of an address. |
| * @param addr the address to get the offset of. |
| * @return the block offset. |
| */ |
| int extractBlkOffset(Addr addr) const |
| { |
| return (addr & blkMask); |
| } |
| |
| /** |
| * Limit the allocation for the cache ways. |
| * @param ways The maximum number of ways available for replacement. |
| */ |
| virtual void setWayAllocationMax(int ways) |
| { |
| panic("This tag class does not implement way allocation limit!\n"); |
| } |
| |
| /** |
| * Get the way allocation mask limit. |
| * @return The maximum number of ways available for replacement. |
| */ |
| virtual int getWayAllocationMax() const |
| { |
| panic("This tag class does not implement way allocation limit!\n"); |
| return -1; |
| } |
| |
| /** |
| * This function updates the tags when a block is invalidated |
| * |
| * @param blk A valid block to invalidate. |
| */ |
| virtual void invalidate(CacheBlk *blk) |
| { |
| assert(blk); |
| assert(blk->isValid()); |
| |
| stats.occupancies[blk->getSrcRequestorId()]--; |
| stats.totalRefs += blk->getRefCount(); |
| stats.sampledRefs++; |
| |
| blk->invalidate(); |
| } |
| |
| /** |
| * Find replacement victim based on address. If the address requires |
| * blocks to be evicted, their locations are listed for eviction. If a |
| * conventional cache is being used, the list only contains the victim. |
| * However, if using sector or compressed caches, the victim is one of |
| * the blocks to be evicted, but its location is the only one that will |
| * be assigned to the newly allocated block associated to this address. |
| * @sa insertBlock |
| * |
| * @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. |
| */ |
| virtual CacheBlk* findVictim(Addr addr, const bool is_secure, |
| const std::size_t size, |
| std::vector<CacheBlk*>& evict_blks) = 0; |
| |
| /** |
| * 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. |
| */ |
| virtual CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) = 0; |
| |
| /** |
| * Generate the tag from the given address. |
| * |
| * @param addr The address to get the tag from. |
| * @return The tag of the address. |
| */ |
| virtual Addr extractTag(const Addr addr) const; |
| |
| /** |
| * Insert the new block into the cache and update stats. |
| * |
| * @param pkt Packet holding the address to update |
| * @param blk The block to update. |
| */ |
| virtual void insertBlock(const PacketPtr pkt, CacheBlk *blk); |
| |
| /** |
| * Move a block's metadata to another location decided by the replacement |
| * policy. It behaves as a swap, however, since the destination block |
| * should be invalid, the result is a move. |
| * |
| * @param src_blk The source block. |
| * @param dest_blk The destination block. Must be invalid. |
| */ |
| virtual void moveBlock(CacheBlk *src_blk, CacheBlk *dest_blk); |
| |
| /** |
| * Regenerate the block address. |
| * |
| * @param block The block. |
| * @return the block address. |
| */ |
| virtual Addr regenerateBlkAddr(const CacheBlk* blk) const = 0; |
| |
| /** |
| * Visit each 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. |
| */ |
| virtual void forEachBlk(std::function<void(CacheBlk &)> visitor) = 0; |
| |
| /** |
| * Find if any of the 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. |
| */ |
| virtual bool anyBlk(std::function<bool(CacheBlk &)> visitor) = 0; |
| |
| private: |
| /** |
| * Update the reference stats using data from the input block |
| * |
| * @param blk The input block |
| */ |
| void cleanupRefsVisitor(CacheBlk &blk); |
| |
| /** |
| * Update the occupancy and age stats using data from the input block |
| * |
| * @param blk The input block |
| */ |
| void computeStatsVisitor(CacheBlk &blk); |
| }; |
| |
| #endif //__MEM_CACHE_TAGS_BASE_HH__ |