diff options
Diffstat (limited to 'src/mem/cache/tags/indexing_policies/base.hh')
| -rw-r--r-- | src/mem/cache/tags/indexing_policies/base.hh | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/src/mem/cache/tags/indexing_policies/base.hh b/src/mem/cache/tags/indexing_policies/base.hh new file mode 100644 index 000000000..02c175d1a --- /dev/null +++ b/src/mem/cache/tags/indexing_policies/base.hh @@ -0,0 +1,163 @@ +/* + * Copyright (c) 2018 Inria + * Copyright (c) 2012-2014,2017 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) 2003-2005,2014 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. + * + * Authors: Daniel Carvalho + * Erik Hallnor + */ + +/** + * @file + * Declaration of a common framework for indexing policies. + */ + +#ifndef __MEM_CACHE_INDEXING_POLICIES_BASE_HH__ +#define __MEM_CACHE_INDEXING_POLICIES_BASE_HH__ + +#include <vector> + +#include "params/BaseIndexingPolicy.hh" +#include "sim/sim_object.hh" + +class ReplaceableEntry; + +/** + * A common base class for indexing table locations. Classes that inherit + * from it determine hash functions that should be applied based on the set + * and way. These functions are then applied to re-map the original values. + * @sa \ref gem5MemorySystem "gem5 Memory System" + */ +class BaseIndexingPolicy : public SimObject +{ + protected: + /** + * The associativity. + */ + const unsigned assoc; + + /** + * The number of sets in the cache. + */ + const uint32_t numSets; + + /** + * The amount to shift the address to get the set. + */ + const int setShift; + + /** + * Mask out all bits that aren't part of the set index. + */ + const unsigned setMask; + + /** + * The cache sets. + */ + std::vector<std::vector<ReplaceableEntry*>> sets; + + /** + * The amount to shift the address to get the tag. + */ + const int tagShift; + + public: + /** + * Convenience typedef. + */ + typedef BaseIndexingPolicyParams Params; + + /** + * Construct and initialize this policy. + */ + BaseIndexingPolicy(const Params *p); + + /** + * Destructor. + */ + ~BaseIndexingPolicy() {}; + + /** + * Associate a pointer to an entry to its physical counterpart. + * + * @param entry The entry pointer. + * @param index An unique index for the entry. + */ + void setEntry(ReplaceableEntry* entry, const uint64_t index); + + /** + * Get an entry based on its set and way. All entries must have been set + * already before calling this function. + * + * @param set The set of the desired entry. + * @param way The way of the desired entry. + * @return entry The entry pointer. + */ + ReplaceableEntry* getEntry(const uint32_t set, const uint32_t way) const; + + /** + * Generate the tag from the given address. + * + * @param addr The address to get the tag from. + * @return The tag of the address. + */ + Addr extractTag(const Addr addr) const; + + /** + * Find all possible entries for insertion and replacement of an address. + * Should be called immediately before ReplacementPolicy's findVictim() + * not to break cache resizing. + * + * @param addr The addr to a find possible entries for. + * @return The possible entries. + */ + virtual std::vector<ReplaceableEntry*> getPossibleEntries(const Addr addr) + const = 0; + + /** + * Regenerate an entry's address from its tag and assigned indexing bits. + * + * @param tag The tag bits. + * @param entry The entry. + * @return the entry's original address. + */ + virtual Addr regenerateAddr(const Addr tag, const ReplaceableEntry* entry) + const = 0; +}; + +#endif //__MEM_CACHE_INDEXING_POLICIES_BASE_HH__ |