base, mem-cache: Templatize the BaseIndexingPolicy

Change-Id: I4a7a0effd0100371afbd31c51d8ac643049dbdb1
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

src/mem/cache/prefetch/stride.hh

@@ -63,7 +63,6 @@
 namespace gem5
 {
 
-class BaseIndexingPolicy;
 namespace replacement_policy
 {
     class Base;

src/mem/cache/tags/base.hh

@@ -56,6 +56,7 @@
 #include "base/statistics.hh"
 #include "base/types.hh"
 #include "mem/cache/cache_blk.hh"
+#include "mem/cache/tags/indexing_policies/base.hh"
 #include "mem/packet.hh"
 #include "params/BaseTags.hh"
 #include "sim/clocked_object.hh"
@@ -64,7 +65,6 @@ namespace gem5
 {
 
 class System;
-class IndexingPolicy;
 class ReplaceableEntry;
 
 /**

src/mem/cache/tags/indexing_policies/IndexingPolicies.py

@@ -1,3 +1,16 @@
+# -*- mode:python -*-
+# Copyright (c) 2024 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) 2018 Inria
 # All rights reserved.
 #
@@ -32,8 +45,9 @@ from m5.SimObject import SimObject
 class BaseIndexingPolicy(SimObject):
     type = "BaseIndexingPolicy"
     abstract = True
-    cxx_class = "gem5::BaseIndexingPolicy"
+    cxx_class = "gem5::IndexingPolicyTemplate<gem5::AddrTypes>"
     cxx_header = "mem/cache/tags/indexing_policies/base.hh"
+    cxx_template_params = ["class Types"]
 
     # Get the size from the parent (cache)
     size = Param.MemorySize(Parent.size, "capacity in bytes")

src/mem/cache/tags/indexing_policies/SConscript

@@ -30,6 +30,5 @@ Import('*')
 SimObject('IndexingPolicies.py', sim_objects=[
     'BaseIndexingPolicy', 'SetAssociative', 'SkewedAssociative'])
 
-Source('base.cc')
 Source('set_associative.cc')
 Source('skewed_associative.cc')

src/mem/cache/tags/indexing_policies/base.cc

@@ -1,104 +0,0 @@
-/*
- * 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
- * Definitions of a common framework for indexing policies.
- */
-
-#include "mem/cache/tags/indexing_policies/base.hh"
-
-#include <cstdlib>
-
-#include "base/intmath.hh"
-#include "base/logging.hh"
-#include "mem/cache/replacement_policies/replaceable_entry.hh"
-
-namespace gem5
-{
-
-BaseIndexingPolicy::BaseIndexingPolicy(const Params &p)
-    : SimObject(p), assoc(p.assoc),
-      numSets(p.size / (p.entry_size * assoc)),
-      setShift(floorLog2(p.entry_size)), setMask(numSets - 1), sets(numSets),
-      tagShift(setShift + floorLog2(numSets))
-{
-    fatal_if(!isPowerOf2(numSets), "# of sets must be non-zero and a power " \
-             "of 2");
-    fatal_if(assoc <= 0, "associativity must be greater than zero");
-
-    // Make space for the entries
-    for (uint32_t i = 0; i < numSets; ++i) {
-        sets[i].resize(assoc);
-    }
-}
-
-ReplaceableEntry*
-BaseIndexingPolicy::getEntry(const uint32_t set, const uint32_t way) const
-{
-    return sets[set][way];
-}
-
-void
-BaseIndexingPolicy::setEntry(ReplaceableEntry* entry, const uint64_t index)
-{
-    // Calculate set and way from entry index
-    const std::lldiv_t div_result = std::div((long long)index, assoc);
-    const uint32_t set = div_result.quot;
-    const uint32_t way = div_result.rem;
-
-    // Sanity check
-    assert(set < numSets);
-
-    // Assign a free pointer
-    sets[set][way] = entry;
-
-    // Inform the entry its position
-    entry->setPosition(set, way);
-}
-
-Addr
-BaseIndexingPolicy::extractTag(const Addr addr) const
-{
-    return (addr >> tagShift);
-}
-
-} // namespace gem5

src/mem/cache/tags/indexing_policies/base.hh

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2018 Inria
- * Copyright (c) 2012-2014,2017 ARM Limited
+ * Copyright (c) 2012-2014,2017,2024 Arm Limited
  * All rights reserved.
  *
  * The license below extends only to copyright in the software and shall
@@ -49,23 +49,32 @@
 
 #include <vector>
 
+#include "base/intmath.hh"
+#include "base/logging.hh"
+#include "mem/cache/replacement_policies/replaceable_entry.hh"
 #include "params/BaseIndexingPolicy.hh"
 #include "sim/sim_object.hh"
 
 namespace gem5
 {
 
-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"
+ * @tparam Types the Types template parameter shall contain the following type
+ *         traits:
+ *           - KeyType = The key/lookup data type
+ *           - Params = The indexing policy Param type
  */
-class BaseIndexingPolicy : public SimObject
+template <class Types>
+class IndexingPolicyTemplate : public SimObject
 {
   protected:
+    using KeyType = typename Types::KeyType;
+    using Params = typename Types::Params;
+
     /**
      * The associativity.
      */
@@ -97,20 +106,29 @@ class BaseIndexingPolicy : public SimObject
     const int tagShift;
 
   public:
-    /**
-     * Convenience typedef.
-     */
-    typedef BaseIndexingPolicyParams Params;
-
     /**
      * Construct and initialize this policy.
      */
-    BaseIndexingPolicy(const Params &p);
+    IndexingPolicyTemplate(const Params &p)
+      : SimObject(p), assoc(p.assoc),
+        numSets(p.size / (p.entry_size * assoc)),
+        setShift(floorLog2(p.entry_size)), setMask(numSets - 1), sets(numSets),
+        tagShift(setShift + floorLog2(numSets))
+    {
+        fatal_if(!isPowerOf2(numSets), "# of sets must be non-zero and a power " \
+                 "of 2");
+        fatal_if(assoc <= 0, "associativity must be greater than zero");
+
+        // Make space for the entries
+        for (uint32_t i = 0; i < numSets; ++i) {
+            sets[i].resize(assoc);
+        }
+    }
 
     /**
      * Destructor.
      */
-    ~BaseIndexingPolicy() {};
+    ~IndexingPolicyTemplate() {};
 
     /**
      * Associate a pointer to an entry to its physical counterpart.
@@ -118,7 +136,23 @@ class BaseIndexingPolicy : public SimObject
      * @param entry The entry pointer.
      * @param index An unique index for the entry.
      */
-    void setEntry(ReplaceableEntry* entry, const uint64_t index);
+    void
+    setEntry(ReplaceableEntry* entry, const uint64_t index)
+    {
+        // Calculate set and way from entry index
+        const std::lldiv_t div_result = std::div((long long)index, assoc);
+        const uint32_t set = div_result.quot;
+        const uint32_t way = div_result.rem;
+
+        // Sanity check
+        assert(set < numSets);
+
+        // Assign a free pointer
+        sets[set][way] = entry;
+
+        // Inform the entry its position
+        entry->setPosition(set, way);
+    }
 
     /**
      * Get an entry based on its set and way. All entries must have been set
@@ -128,7 +162,11 @@ class BaseIndexingPolicy : public SimObject
      * @param way The way of the desired entry.
      * @return entry The entry pointer.
      */
-    ReplaceableEntry* getEntry(const uint32_t set, const uint32_t way) const;
+    ReplaceableEntry*
+    getEntry(const uint32_t set, const uint32_t way) const
+    {
+        return sets[set][way];
+    }
 
     /**
      * Generate the tag from the given address.
@@ -136,7 +174,12 @@ class BaseIndexingPolicy : public SimObject
      * @param addr The address to get the tag from.
      * @return The tag of the address.
      */
-    virtual Addr extractTag(const Addr addr) const;
+    virtual Addr
+    extractTag(const Addr addr) const
+    {
+        return (addr >> tagShift);
+    }
+
 
     /**
      * Find all possible entries for insertion and replacement of an address.
@@ -146,7 +189,7 @@ class BaseIndexingPolicy : public SimObject
      * @param addr The addr to a find possible entries for.
      * @return The possible entries.
      */
-    virtual std::vector<ReplaceableEntry*> getPossibleEntries(const Addr addr)
+    virtual std::vector<ReplaceableEntry*> getPossibleEntries(const KeyType &key)
                                                                     const = 0;
 
     /**
@@ -156,10 +199,20 @@ class BaseIndexingPolicy : public SimObject
      * @param entry The entry.
      * @return the entry's original address.
      */
-    virtual Addr regenerateAddr(const Addr tag, const ReplaceableEntry* entry)
-                                                                    const = 0;
+    virtual Addr regenerateAddr(const KeyType &key,
+                                const ReplaceableEntry* entry) const = 0;
 };
 
+class AddrTypes
+{
+  public:
+    using KeyType = Addr;
+    using Params = BaseIndexingPolicyParams;
+};
+
+using BaseIndexingPolicy = IndexingPolicyTemplate<AddrTypes>;
+template class IndexingPolicyTemplate<AddrTypes>;
+
 } // namespace gem5
 
 #endif //__MEM_CACHE_INDEXING_POLICIES_BASE_HH__

src/mem/cache/tags/indexing_policies/set_associative.cc

@@ -63,14 +63,14 @@ SetAssociative::extractSet(const Addr addr) const
 }
 
 Addr
-SetAssociative::regenerateAddr(const Addr tag, const ReplaceableEntry* entry)
-                                                                        const
+SetAssociative::regenerateAddr(const Addr &tag,
+                               const ReplaceableEntry* entry) const
 {
     return (tag << tagShift) | (entry->getSet() << setShift);
 }
 
 std::vector<ReplaceableEntry*>
-SetAssociative::getPossibleEntries(const Addr addr) const
+SetAssociative::getPossibleEntries(const Addr &addr) const
 {
     return sets[extractSet(addr)];
 }

src/mem/cache/tags/indexing_policies/set_associative.hh

@@ -115,7 +115,7 @@ class SetAssociative : public BaseIndexingPolicy
      * @param addr The addr to a find possible entries for.
      * @return The possible entries.
      */
-    std::vector<ReplaceableEntry*> getPossibleEntries(const Addr addr) const
+    std::vector<ReplaceableEntry*> getPossibleEntries(const Addr &addr) const
                                                                      override;
 
     /**
@@ -125,8 +125,8 @@ class SetAssociative : public BaseIndexingPolicy
      * @param entry The entry.
      * @return the entry's original addr value.
      */
-    Addr regenerateAddr(const Addr tag, const ReplaceableEntry* entry) const
-                                                                   override;
+    Addr regenerateAddr(const Addr &tag,
+                        const ReplaceableEntry* entry) const override;
 };
 
 } // namespace gem5

src/mem/cache/tags/indexing_policies/skewed_associative.cc

@@ -198,7 +198,7 @@ SkewedAssociative::extractSet(const Addr addr, const uint32_t way) const
 }
 
 Addr
-SkewedAssociative::regenerateAddr(const Addr tag,
+SkewedAssociative::regenerateAddr(const Addr &tag,
                                   const ReplaceableEntry* entry) const
 {
     const Addr addr_set = (tag << (msbShift + 1)) | entry->getSet();
@@ -207,7 +207,7 @@ SkewedAssociative::regenerateAddr(const Addr tag,
 }
 
 std::vector<ReplaceableEntry*>
-SkewedAssociative::getPossibleEntries(const Addr addr) const
+SkewedAssociative::getPossibleEntries(const Addr &addr) const
 {
     std::vector<ReplaceableEntry*> entries;
 

src/mem/cache/tags/indexing_policies/skewed_associative.hh

@@ -160,7 +160,7 @@ class SkewedAssociative : public BaseIndexingPolicy
      * @param addr The addr to a find possible entries for.
      * @return The possible entries.
      */
-    std::vector<ReplaceableEntry*> getPossibleEntries(const Addr addr) const
+    std::vector<ReplaceableEntry*> getPossibleEntries(const Addr &addr) const
                                                                    override;
 
     /**
@@ -171,8 +171,8 @@ class SkewedAssociative : public BaseIndexingPolicy
      * @param entry The entry.
      * @return the entry's address.
      */
-    Addr regenerateAddr(const Addr tag, const ReplaceableEntry* entry) const
-                                                                   override;
+    Addr regenerateAddr(const Addr &tag,
+                        const ReplaceableEntry* entry) const override;
 };
 
 } // namespace gem5