| /* |
| * 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. |
| */ |
| |
| /** |
| * @file |
| * Declaration of a set associative indexing policy. |
| */ |
| |
| #ifndef __MEM_CACHE_INDEXING_POLICIES_SET_ASSOCIATIVE_HH__ |
| #define __MEM_CACHE_INDEXING_POLICIES_SET_ASSOCIATIVE_HH__ |
| |
| #include <vector> |
| |
| #include "mem/cache/tags/indexing_policies/base.hh" |
| #include "params/SetAssociative.hh" |
| |
| namespace gem5 |
| { |
| |
| class ReplaceableEntry; |
| |
| /** |
| * A set associative indexing policy. |
| * @sa \ref gem5MemorySystem "gem5 Memory System" |
| * |
| * The set associative indexing policy has an immutable/identity mapping, so a |
| * value x is always mapped to set x, independent of the way, that is, |
| * Hash(A, 0) = Hash(A, 1) = Hash(A, N-1), where N is the number of ways. |
| * |
| * For example, let's assume address A maps to set 3 on way 0. This policy |
| * makes so that A is also mappable to set 3 on every other way. Visually, the |
| * possible locations of A are, for a table with 4 ways and 8 sets: |
| * Way 0 1 2 3 |
| * Set _ _ _ _ |
| * 0 |_| |_| |_| |_| |
| * 1 |_| |_| |_| |_| |
| * 2 |_| |_| |_| |_| |
| * 3 |X| |X| |X| |X| |
| * 4 |_| |_| |_| |_| |
| * 5 |_| |_| |_| |_| |
| * 6 |_| |_| |_| |_| |
| * 7 |_| |_| |_| |_| |
| */ |
| class SetAssociative : public BaseIndexingPolicy |
| { |
| protected: |
| /** |
| * Apply a hash function to calculate address set. |
| * |
| * @param addr The address to calculate the set for. |
| * @return The set index for given combination of address and way. |
| */ |
| virtual uint32_t extractSet(const Addr addr) const; |
| |
| public: |
| /** |
| * Convenience typedef. |
| */ |
| typedef SetAssociativeParams Params; |
| |
| /** |
| * Construct and initialize this policy. |
| */ |
| SetAssociative(const Params &p); |
| |
| /** |
| * Destructor. |
| */ |
| ~SetAssociative() {}; |
| |
| /** |
| * Find all possible entries for insertion and replacement of an address. |
| * Should be called immediately before ReplacementPolicy's findVictim() |
| * not to break cache resizing. |
| * Returns entries in all ways belonging to the set of the address. |
| * |
| * @param addr The addr to a find possible entries for. |
| * @return The possible entries. |
| */ |
| std::vector<ReplaceableEntry*> getPossibleEntries(const Addr addr) const |
| override; |
| |
| /** |
| * Regenerate an entry's address from its tag and assigned set and way. |
| * |
| * @param tag The tag bits. |
| * @param entry The entry. |
| * @return the entry's original addr value. |
| */ |
| Addr regenerateAddr(const Addr tag, const ReplaceableEntry* entry) const |
| override; |
| }; |
| |
| } // namespace gem5 |
| |
| #endif //__MEM_CACHE_INDEXING_POLICIES_SET_ASSOCIATIVE_HH__ |