base_set_assoc.hh revision 12554
110263Satgutier@umich.edu/* 210941Sdavid.guillen@arm.com * Copyright (c) 2012-2014 ARM Limited 310263Satgutier@umich.edu * All rights reserved. 410263Satgutier@umich.edu * 510263Satgutier@umich.edu * The license below extends only to copyright in the software and shall 610263Satgutier@umich.edu * not be construed as granting a license to any other intellectual 710263Satgutier@umich.edu * property including but not limited to intellectual property relating 810263Satgutier@umich.edu * to a hardware implementation of the functionality of the software 910263Satgutier@umich.edu * licensed hereunder. You may use the software subject to the license 1010263Satgutier@umich.edu * terms below provided that you ensure that this notice is replicated 1110263Satgutier@umich.edu * unmodified and in its entirety in all distributions of the software, 1210263Satgutier@umich.edu * modified or unmodified, in source code or in binary form. 1310263Satgutier@umich.edu * 1410263Satgutier@umich.edu * Copyright (c) 2003-2005,2014 The Regents of The University of Michigan 1510263Satgutier@umich.edu * All rights reserved. 1610263Satgutier@umich.edu * 1710263Satgutier@umich.edu * Redistribution and use in source and binary forms, with or without 1810263Satgutier@umich.edu * modification, are permitted provided that the following conditions are 1910263Satgutier@umich.edu * met: redistributions of source code must retain the above copyright 2010263Satgutier@umich.edu * notice, this list of conditions and the following disclaimer; 2110263Satgutier@umich.edu * redistributions in binary form must reproduce the above copyright 2210263Satgutier@umich.edu * notice, this list of conditions and the following disclaimer in the 2310263Satgutier@umich.edu * documentation and/or other materials provided with the distribution; 2410263Satgutier@umich.edu * neither the name of the copyright holders nor the names of its 2510263Satgutier@umich.edu * contributors may be used to endorse or promote products derived from 2610263Satgutier@umich.edu * this software without specific prior written permission. 2710263Satgutier@umich.edu * 2810263Satgutier@umich.edu * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 2910263Satgutier@umich.edu * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 3010263Satgutier@umich.edu * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 3110263Satgutier@umich.edu * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 3210263Satgutier@umich.edu * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 3310263Satgutier@umich.edu * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 3410263Satgutier@umich.edu * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 3510263Satgutier@umich.edu * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 3610263Satgutier@umich.edu * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 3710263Satgutier@umich.edu * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 3810263Satgutier@umich.edu * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 3910263Satgutier@umich.edu * 4010263Satgutier@umich.edu * Authors: Erik Hallnor 4110263Satgutier@umich.edu */ 4210263Satgutier@umich.edu 4310263Satgutier@umich.edu/** 4410263Satgutier@umich.edu * @file 4510263Satgutier@umich.edu * Declaration of a base set associative tag store. 4610263Satgutier@umich.edu */ 4710263Satgutier@umich.edu 4812492Sodanrc@yahoo.com.br#ifndef __MEM_CACHE_TAGS_BASE_SET_ASSOC_HH__ 4912492Sodanrc@yahoo.com.br#define __MEM_CACHE_TAGS_BASE_SET_ASSOC_HH__ 5010263Satgutier@umich.edu 5110263Satgutier@umich.edu#include <cassert> 5210263Satgutier@umich.edu#include <cstring> 5312548Sodanrc@yahoo.com.br#include <memory> 5412548Sodanrc@yahoo.com.br#include <vector> 5510263Satgutier@umich.edu 5611486Snikos.nikoleris@arm.com#include "mem/cache/base.hh" 5711486Snikos.nikoleris@arm.com#include "mem/cache/blk.hh" 5810263Satgutier@umich.edu#include "mem/cache/tags/base.hh" 5910263Satgutier@umich.edu#include "mem/cache/tags/cacheset.hh" 6010263Satgutier@umich.edu#include "mem/packet.hh" 6110263Satgutier@umich.edu#include "params/BaseSetAssoc.hh" 6210263Satgutier@umich.edu 6310263Satgutier@umich.edu/** 6410263Satgutier@umich.edu * A BaseSetAssoc cache tag store. 6510263Satgutier@umich.edu * @sa \ref gem5MemorySystem "gem5 Memory System" 6610263Satgutier@umich.edu * 6710263Satgutier@umich.edu * The BaseSetAssoc tags provide a base, as well as the functionality 6810263Satgutier@umich.edu * common to any set associative tags. Any derived class must implement 6910263Satgutier@umich.edu * the methods related to the specifics of the actual replacment policy. 7010263Satgutier@umich.edu * These are: 7110263Satgutier@umich.edu * 7210263Satgutier@umich.edu * BlkType* accessBlock(); 7310263Satgutier@umich.edu * BlkType* findVictim(); 7410263Satgutier@umich.edu * void insertBlock(); 7510263Satgutier@umich.edu * void invalidate(); 7610263Satgutier@umich.edu */ 7710263Satgutier@umich.educlass BaseSetAssoc : public BaseTags 7810263Satgutier@umich.edu{ 7910263Satgutier@umich.edu public: 8010263Satgutier@umich.edu /** Typedef the block type used in this tag store. */ 8110263Satgutier@umich.edu typedef CacheBlk BlkType; 8210263Satgutier@umich.edu /** Typedef the set type used in this tag store. */ 8310263Satgutier@umich.edu typedef CacheSet<CacheBlk> SetType; 8410263Satgutier@umich.edu 8510263Satgutier@umich.edu 8610263Satgutier@umich.edu protected: 8710263Satgutier@umich.edu /** The associativity of the cache. */ 8810263Satgutier@umich.edu const unsigned assoc; 8910941Sdavid.guillen@arm.com /** The allocatable associativity of the cache (alloc mask). */ 9010941Sdavid.guillen@arm.com unsigned allocAssoc; 9112548Sodanrc@yahoo.com.br 9212548Sodanrc@yahoo.com.br /** The cache blocks. */ 9312548Sodanrc@yahoo.com.br std::vector<BlkType> blks; 9412548Sodanrc@yahoo.com.br /** The data blocks, 1 per cache block. */ 9512548Sodanrc@yahoo.com.br std::unique_ptr<uint8_t[]> dataBlks; 9612548Sodanrc@yahoo.com.br 9710263Satgutier@umich.edu /** The number of sets in the cache. */ 9810263Satgutier@umich.edu const unsigned numSets; 9912548Sodanrc@yahoo.com.br 10010263Satgutier@umich.edu /** Whether tags and data are accessed sequentially. */ 10110263Satgutier@umich.edu const bool sequentialAccess; 10210263Satgutier@umich.edu 10310263Satgutier@umich.edu /** The cache sets. */ 10412548Sodanrc@yahoo.com.br std::vector<SetType> sets; 10510263Satgutier@umich.edu 10610263Satgutier@umich.edu /** The amount to shift the address to get the set. */ 10710263Satgutier@umich.edu int setShift; 10810263Satgutier@umich.edu /** The amount to shift the address to get the tag. */ 10910263Satgutier@umich.edu int tagShift; 11010263Satgutier@umich.edu /** Mask out all bits that aren't part of the set index. */ 11110263Satgutier@umich.edu unsigned setMask; 11210263Satgutier@umich.edu 11310263Satgutier@umich.edupublic: 11410263Satgutier@umich.edu 11510263Satgutier@umich.edu /** Convenience typedef. */ 11610263Satgutier@umich.edu typedef BaseSetAssocParams Params; 11710263Satgutier@umich.edu 11810263Satgutier@umich.edu /** 11910263Satgutier@umich.edu * Construct and initialize this tag store. 12010263Satgutier@umich.edu */ 12110263Satgutier@umich.edu BaseSetAssoc(const Params *p); 12210263Satgutier@umich.edu 12310263Satgutier@umich.edu /** 12410263Satgutier@umich.edu * Destructor 12510263Satgutier@umich.edu */ 12612548Sodanrc@yahoo.com.br virtual ~BaseSetAssoc() {}; 12710263Satgutier@umich.edu 12810263Satgutier@umich.edu /** 12910941Sdavid.guillen@arm.com * Find the cache block given set and way 13010941Sdavid.guillen@arm.com * @param set The set of the block. 13110941Sdavid.guillen@arm.com * @param way The way of the block. 13210941Sdavid.guillen@arm.com * @return The cache block. 13310941Sdavid.guillen@arm.com */ 13411169Sandreas.hansson@arm.com CacheBlk *findBlockBySetAndWay(int set, int way) const override; 13510941Sdavid.guillen@arm.com 13610941Sdavid.guillen@arm.com /** 13710263Satgutier@umich.edu * Invalidate the given block. 13810263Satgutier@umich.edu * @param blk The block to invalidate. 13910263Satgutier@umich.edu */ 14011169Sandreas.hansson@arm.com void invalidate(CacheBlk *blk) override 14110263Satgutier@umich.edu { 14210263Satgutier@umich.edu assert(blk); 14310263Satgutier@umich.edu assert(blk->isValid()); 14410263Satgutier@umich.edu tagsInUse--; 14510263Satgutier@umich.edu assert(blk->srcMasterId < cache->system->maxMasters()); 14610263Satgutier@umich.edu occupancies[blk->srcMasterId]--; 14710263Satgutier@umich.edu blk->srcMasterId = Request::invldMasterId; 14810263Satgutier@umich.edu blk->task_id = ContextSwitchTaskId::Unknown; 14910263Satgutier@umich.edu blk->tickInserted = curTick(); 15010263Satgutier@umich.edu } 15110263Satgutier@umich.edu 15210263Satgutier@umich.edu /** 15310263Satgutier@umich.edu * Access block and update replacement data. May not succeed, in which case 15411484Snikos.nikoleris@arm.com * nullptr is returned. This has all the implications of a cache 15510263Satgutier@umich.edu * access and should only be used as such. Returns the access latency as a 15610263Satgutier@umich.edu * side effect. 15710263Satgutier@umich.edu * @param addr The address to find. 15810263Satgutier@umich.edu * @param is_secure True if the target memory space is secure. 15910263Satgutier@umich.edu * @param lat The access latency. 16010263Satgutier@umich.edu * @return Pointer to the cache block if found. 16110263Satgutier@umich.edu */ 16211870Snikos.nikoleris@arm.com CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) override 16310263Satgutier@umich.edu { 16410263Satgutier@umich.edu Addr tag = extractTag(addr); 16510263Satgutier@umich.edu int set = extractSet(addr); 16610263Satgutier@umich.edu BlkType *blk = sets[set].findBlk(tag, is_secure); 16710263Satgutier@umich.edu 16810263Satgutier@umich.edu // Access all tags in parallel, hence one in each way. The data side 16910263Satgutier@umich.edu // either accesses all blocks in parallel, or one block sequentially on 17010263Satgutier@umich.edu // a hit. Sequential access with a miss doesn't access data. 17110941Sdavid.guillen@arm.com tagAccesses += allocAssoc; 17210263Satgutier@umich.edu if (sequentialAccess) { 17311484Snikos.nikoleris@arm.com if (blk != nullptr) { 17410263Satgutier@umich.edu dataAccesses += 1; 17510263Satgutier@umich.edu } 17610263Satgutier@umich.edu } else { 17710941Sdavid.guillen@arm.com dataAccesses += allocAssoc; 17810263Satgutier@umich.edu } 17910263Satgutier@umich.edu 18011484Snikos.nikoleris@arm.com if (blk != nullptr) { 18111722Ssophiane.senni@gmail.com // If a cache hit 18211722Ssophiane.senni@gmail.com lat = accessLatency; 18311722Ssophiane.senni@gmail.com // Check if the block to be accessed is available. If not, 18411722Ssophiane.senni@gmail.com // apply the accessLatency on top of block->whenReady. 18511722Ssophiane.senni@gmail.com if (blk->whenReady > curTick() && 18611722Ssophiane.senni@gmail.com cache->ticksToCycles(blk->whenReady - curTick()) > 18711722Ssophiane.senni@gmail.com accessLatency) { 18811722Ssophiane.senni@gmail.com lat = cache->ticksToCycles(blk->whenReady - curTick()) + 18911722Ssophiane.senni@gmail.com accessLatency; 19010263Satgutier@umich.edu } 19110263Satgutier@umich.edu blk->refCount += 1; 19211722Ssophiane.senni@gmail.com } else { 19311722Ssophiane.senni@gmail.com // If a cache miss 19411722Ssophiane.senni@gmail.com lat = lookupLatency; 19510263Satgutier@umich.edu } 19610263Satgutier@umich.edu 19710263Satgutier@umich.edu return blk; 19810263Satgutier@umich.edu } 19910263Satgutier@umich.edu 20010263Satgutier@umich.edu /** 20110263Satgutier@umich.edu * Finds the given address in the cache, do not update replacement data. 20210263Satgutier@umich.edu * i.e. This is a no-side-effect find of a block. 20310263Satgutier@umich.edu * @param addr The address to find. 20410263Satgutier@umich.edu * @param is_secure True if the target memory space is secure. 20510263Satgutier@umich.edu * @param asid The address space ID. 20610263Satgutier@umich.edu * @return Pointer to the cache block if found. 20710263Satgutier@umich.edu */ 20811169Sandreas.hansson@arm.com CacheBlk* findBlock(Addr addr, bool is_secure) const override; 20910263Satgutier@umich.edu 21010263Satgutier@umich.edu /** 21110263Satgutier@umich.edu * Find an invalid block to evict for the address provided. 21210263Satgutier@umich.edu * If there are no invalid blocks, this will return the block 21310263Satgutier@umich.edu * in the least-recently-used position. 21410263Satgutier@umich.edu * @param addr The addr to a find a replacement candidate for. 21510263Satgutier@umich.edu * @return The candidate block. 21610263Satgutier@umich.edu */ 21711169Sandreas.hansson@arm.com CacheBlk* findVictim(Addr addr) override 21810263Satgutier@umich.edu { 21911484Snikos.nikoleris@arm.com BlkType *blk = nullptr; 22010263Satgutier@umich.edu int set = extractSet(addr); 22110263Satgutier@umich.edu 22210263Satgutier@umich.edu // prefer to evict an invalid block 22310941Sdavid.guillen@arm.com for (int i = 0; i < allocAssoc; ++i) { 22410263Satgutier@umich.edu blk = sets[set].blks[i]; 22510941Sdavid.guillen@arm.com if (!blk->isValid()) 22610263Satgutier@umich.edu break; 22710263Satgutier@umich.edu } 22810263Satgutier@umich.edu 22910263Satgutier@umich.edu return blk; 23010263Satgutier@umich.edu } 23110263Satgutier@umich.edu 23210263Satgutier@umich.edu /** 23310263Satgutier@umich.edu * Insert the new block into the cache. 23410263Satgutier@umich.edu * @param pkt Packet holding the address to update 23510263Satgutier@umich.edu * @param blk The block to update. 23610263Satgutier@umich.edu */ 23711169Sandreas.hansson@arm.com void insertBlock(PacketPtr pkt, CacheBlk *blk) override 23810263Satgutier@umich.edu { 23910263Satgutier@umich.edu Addr addr = pkt->getAddr(); 24010263Satgutier@umich.edu MasterID master_id = pkt->req->masterId(); 24110263Satgutier@umich.edu uint32_t task_id = pkt->req->taskId(); 24210274Smitch.hayenga@arm.com 24310263Satgutier@umich.edu if (!blk->isTouched) { 24410263Satgutier@umich.edu tagsInUse++; 24510263Satgutier@umich.edu blk->isTouched = true; 24610263Satgutier@umich.edu if (!warmedUp && tagsInUse.value() >= warmupBound) { 24710263Satgutier@umich.edu warmedUp = true; 24810263Satgutier@umich.edu warmupCycle = curTick(); 24910263Satgutier@umich.edu } 25010263Satgutier@umich.edu } 25110263Satgutier@umich.edu 25210263Satgutier@umich.edu // If we're replacing a block that was previously valid update 25310263Satgutier@umich.edu // stats for it. This can't be done in findBlock() because a 25410263Satgutier@umich.edu // found block might not actually be replaced there if the 25510263Satgutier@umich.edu // coherence protocol says it can't be. 25610263Satgutier@umich.edu if (blk->isValid()) { 25710263Satgutier@umich.edu replacements[0]++; 25810263Satgutier@umich.edu totalRefs += blk->refCount; 25910263Satgutier@umich.edu ++sampledRefs; 26010263Satgutier@umich.edu 26112554Snikos.nikoleris@arm.com invalidate(blk); 26210263Satgutier@umich.edu blk->invalidate(); 26310263Satgutier@umich.edu } 26410263Satgutier@umich.edu 26510263Satgutier@umich.edu blk->isTouched = true; 26610274Smitch.hayenga@arm.com 26710263Satgutier@umich.edu // Set tag for new block. Caller is responsible for setting status. 26810263Satgutier@umich.edu blk->tag = extractTag(addr); 26910263Satgutier@umich.edu 27010263Satgutier@umich.edu // deal with what we are bringing in 27110263Satgutier@umich.edu assert(master_id < cache->system->maxMasters()); 27210263Satgutier@umich.edu occupancies[master_id]++; 27310263Satgutier@umich.edu blk->srcMasterId = master_id; 27410263Satgutier@umich.edu blk->task_id = task_id; 27510263Satgutier@umich.edu blk->tickInserted = curTick(); 27610263Satgutier@umich.edu 27710263Satgutier@umich.edu // We only need to write into one tag and one data block. 27810263Satgutier@umich.edu tagAccesses += 1; 27910263Satgutier@umich.edu dataAccesses += 1; 28010263Satgutier@umich.edu } 28110263Satgutier@umich.edu 28210263Satgutier@umich.edu /** 28310941Sdavid.guillen@arm.com * Limit the allocation for the cache ways. 28410941Sdavid.guillen@arm.com * @param ways The maximum number of ways available for replacement. 28510941Sdavid.guillen@arm.com */ 28611169Sandreas.hansson@arm.com virtual void setWayAllocationMax(int ways) override 28710941Sdavid.guillen@arm.com { 28810941Sdavid.guillen@arm.com fatal_if(ways < 1, "Allocation limit must be greater than zero"); 28910941Sdavid.guillen@arm.com allocAssoc = ways; 29010941Sdavid.guillen@arm.com } 29110941Sdavid.guillen@arm.com 29210941Sdavid.guillen@arm.com /** 29310941Sdavid.guillen@arm.com * Get the way allocation mask limit. 29410941Sdavid.guillen@arm.com * @return The maximum number of ways available for replacement. 29510941Sdavid.guillen@arm.com */ 29611169Sandreas.hansson@arm.com virtual int getWayAllocationMax() const override 29710941Sdavid.guillen@arm.com { 29810941Sdavid.guillen@arm.com return allocAssoc; 29910941Sdavid.guillen@arm.com } 30010941Sdavid.guillen@arm.com 30110941Sdavid.guillen@arm.com /** 30210263Satgutier@umich.edu * Generate the tag from the given address. 30310263Satgutier@umich.edu * @param addr The address to get the tag from. 30410263Satgutier@umich.edu * @return The tag of the address. 30510263Satgutier@umich.edu */ 30611169Sandreas.hansson@arm.com Addr extractTag(Addr addr) const override 30710263Satgutier@umich.edu { 30810263Satgutier@umich.edu return (addr >> tagShift); 30910263Satgutier@umich.edu } 31010263Satgutier@umich.edu 31110263Satgutier@umich.edu /** 31210263Satgutier@umich.edu * Calculate the set index from the address. 31310263Satgutier@umich.edu * @param addr The address to get the set from. 31410263Satgutier@umich.edu * @return The set index of the address. 31510263Satgutier@umich.edu */ 31611169Sandreas.hansson@arm.com int extractSet(Addr addr) const override 31710263Satgutier@umich.edu { 31810263Satgutier@umich.edu return ((addr >> setShift) & setMask); 31910263Satgutier@umich.edu } 32010263Satgutier@umich.edu 32110263Satgutier@umich.edu /** 32210263Satgutier@umich.edu * Regenerate the block address from the tag. 32310263Satgutier@umich.edu * @param tag The tag of the block. 32410263Satgutier@umich.edu * @param set The set of the block. 32510263Satgutier@umich.edu * @return The block address. 32610263Satgutier@umich.edu */ 32711169Sandreas.hansson@arm.com Addr regenerateBlkAddr(Addr tag, unsigned set) const override 32810263Satgutier@umich.edu { 32910263Satgutier@umich.edu return ((tag << tagShift) | ((Addr)set << setShift)); 33010263Satgutier@umich.edu } 33110263Satgutier@umich.edu 33210263Satgutier@umich.edu /** 33310263Satgutier@umich.edu * Called at end of simulation to complete average block reference stats. 33410263Satgutier@umich.edu */ 33511169Sandreas.hansson@arm.com void cleanupRefs() override; 33610263Satgutier@umich.edu 33710263Satgutier@umich.edu /** 33810263Satgutier@umich.edu * Print all tags used 33910263Satgutier@umich.edu */ 34011169Sandreas.hansson@arm.com std::string print() const override; 34110263Satgutier@umich.edu 34210263Satgutier@umich.edu /** 34310263Satgutier@umich.edu * Called prior to dumping stats to compute task occupancy 34410263Satgutier@umich.edu */ 34511169Sandreas.hansson@arm.com void computeStats() override; 34610263Satgutier@umich.edu 34710263Satgutier@umich.edu /** 34810263Satgutier@umich.edu * Visit each block in the tag store and apply a visitor to the 34910263Satgutier@umich.edu * block. 35010263Satgutier@umich.edu * 35110263Satgutier@umich.edu * The visitor should be a function (or object that behaves like a 35210263Satgutier@umich.edu * function) that takes a cache block reference as its parameter 35310263Satgutier@umich.edu * and returns a bool. A visitor can request the traversal to be 35410263Satgutier@umich.edu * stopped by returning false, returning true causes it to be 35510263Satgutier@umich.edu * called for the next block in the tag store. 35610263Satgutier@umich.edu * 35710263Satgutier@umich.edu * \param visitor Visitor to call on each block. 35810263Satgutier@umich.edu */ 35911168Sandreas.hansson@arm.com void forEachBlk(CacheBlkVisitor &visitor) override { 36010263Satgutier@umich.edu for (unsigned i = 0; i < numSets * assoc; ++i) { 36110263Satgutier@umich.edu if (!visitor(blks[i])) 36210263Satgutier@umich.edu return; 36310263Satgutier@umich.edu } 36410263Satgutier@umich.edu } 36510263Satgutier@umich.edu}; 36610263Satgutier@umich.edu 36712492Sodanrc@yahoo.com.br#endif //__MEM_CACHE_TAGS_BASE_SET_ASSOC_HH__ 368