diff options
Diffstat (limited to 'src/mem/cache/tags/lru.hh')
| -rw-r--r-- | src/mem/cache/tags/lru.hh | 226 |
1 files changed, 10 insertions, 216 deletions
diff --git a/src/mem/cache/tags/lru.hh b/src/mem/cache/tags/lru.hh index 121bdb292..a034dd6ab 100644 --- a/src/mem/cache/tags/lru.hh +++ b/src/mem/cache/tags/lru.hh @@ -11,7 +11,7 @@ * 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 + * Copyright (c) 2003-2005,2014 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -43,68 +43,21 @@ /** * @file * Declaration of a LRU tag store. + * The LRU tags guarantee that the true least-recently-used way in + * a set will always be evicted. */ #ifndef __MEM_CACHE_TAGS_LRU_HH__ #define __MEM_CACHE_TAGS_LRU_HH__ -#include <cassert> -#include <cstring> -#include <list> - -#include "mem/cache/tags/base.hh" -#include "mem/cache/tags/cacheset.hh" -#include "mem/cache/blk.hh" -#include "mem/packet.hh" +#include "mem/cache/tags/base_set_assoc.hh" #include "params/LRU.hh" -class BaseCache; - - -/** - * A LRU cache tag store. - * @sa \ref gem5MemorySystem "gem5 Memory System" - */ -class LRU : public BaseTags +class LRU : public BaseSetAssoc { public: - /** Typedef the block type used in this tag store. */ - typedef CacheBlk BlkType; - /** Typedef for a list of pointers to the local block class. */ - typedef std::list<BlkType*> BlkList; - /** Typedef the set type used in this tag store. */ - typedef CacheSet<CacheBlk> SetType; - - - protected: - /** The associativity of the cache. */ - const unsigned assoc; - /** The number of sets in the cache. */ - const unsigned numSets; - /** Whether tags and data are accessed sequentially. */ - const bool sequentialAccess; - - /** The cache sets. */ - SetType *sets; - - /** The cache blocks. */ - BlkType *blks; - /** The data blocks, 1 per cache block. */ - uint8_t *dataBlks; - - /** The amount to shift the address to get the set. */ - int setShift; - /** The amount to shift the address to get the tag. */ - int tagShift; - /** Mask out all bits that aren't part of the set index. */ - unsigned setMask; - /** Mask out all bits that aren't part of the block offset. */ - unsigned blkMask; - -public: - /** Convenience typedef. */ - typedef LRUParams Params; + typedef LRUParams Params; /** * Construct and initialize this tag store. @@ -114,172 +67,13 @@ public: /** * Destructor */ - virtual ~LRU(); - - /** - * Return the block size. - * @return the block size. - */ - unsigned - getBlockSize() const - { - return blkSize; - } + ~LRU() {} - /** - * Return the subblock size. In the case of LRU it is always the block - * size. - * @return The block size. - */ - unsigned - getSubBlockSize() const - { - return blkSize; - } - - /** - * Invalidate the given block. - * @param blk The block to invalidate. - */ - void invalidate(BlkType *blk); - - /** - * Access block and update replacement data. May not succeed, in which case - * NULL pointer is returned. This has all the implications of a cache - * access and should only be used as such. Returns the access latency as a side effect. - * @param addr The address to find. - * @param is_secure True if the target memory space is secure. - * @param asid The address space ID. - * @param lat The access latency. - * @return Pointer to the cache block if found. - */ BlkType* accessBlock(Addr addr, bool is_secure, Cycles &lat, int context_src); - - /** - * 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. - * @param asid The address space ID. - * @return Pointer to the cache block if found. - */ - BlkType* findBlock(Addr addr, bool is_secure) const; - - /** - * Find a block to evict for the address provided. - * @param addr The addr to a find a replacement candidate for. - * @return The candidate block. - */ - BlkType* findVictim(Addr addr); - - /** - * Insert the new block into the cache. For LRU this means inserting into - * the MRU position of the set. - * @param pkt Packet holding the address to update - * @param blk The block to update. - */ - void insertBlock(PacketPtr pkt, BlkType *blk); - - /** - * Generate the tag from the given address. - * @param addr The address to get the tag from. - * @return The tag of the address. - */ - Addr extractTag(Addr addr) const - { - return (addr >> tagShift); - } - - /** - * Calculate the set index from the address. - * @param addr The address to get the set from. - * @return The set index of the address. - */ - int extractSet(Addr addr) const - { - return ((addr >> setShift) & setMask); - } - - /** - * Get the block offset from an address. - * @param addr The address to get the offset of. - * @return The block offset. - */ - int extractBlkOffset(Addr addr) const - { - return (addr & blkMask); - } - - /** - * Align an address to the block size. - * @param addr the address to align. - * @return The block address. - */ - Addr blkAlign(Addr addr) const - { - return (addr & ~(Addr)blkMask); - } - - /** - * Regenerate the block address from the tag. - * @param tag The tag of the block. - * @param set The set of the block. - * @return The block address. - */ - Addr regenerateBlkAddr(Addr tag, unsigned set) const - { - return ((tag << tagShift) | ((Addr)set << setShift)); - } - - /** - * Return the hit latency. - * @return the hit latency. - */ - Cycles getHitLatency() const - { - return hitLatency; - } - /** - *iterated through all blocks and clear all locks - *Needed to clear all lock tracking at once - */ - virtual void clearLocks(); - - /** - * Called at end of simulation to complete average block reference stats. - */ - virtual void cleanupRefs(); - - /** - * Print all tags used - */ - virtual std::string print() const; - - /** - * Called prior to dumping stats to compute task occupancy - */ - virtual void computeStats(); - - /** - * Visit each block in the tag store and apply a visitor to the - * block. - * - * The visitor should be a function (or object that behaves like a - * function) that takes a cache block reference as its parameter - * and returns a bool. A visitor can request the traversal to be - * stopped by returning false, returning true causes it to be - * called for the next block in the tag store. - * - * \param visitor Visitor to call on each block. - */ - template <typename V> - void forEachBlk(V &visitor) { - for (unsigned i = 0; i < numSets * assoc; ++i) { - if (!visitor(blks[i])) - return; - } - } + BlkType* findVictim(Addr addr) const; + void insertBlock(PacketPtr pkt, BlkType *blk); + void invalidate(BlkType *blk); }; #endif // __MEM_CACHE_TAGS_LRU_HH__ |