mem-cache: Factor ReplaceableEntry out

ReplaceableEntry is referenced by many classes that do
not necessarily need access to the replacement policies.
Therefore, in order to allow better compilation units,
we factor it out to a new file.

Change-Id: I0823567bf1ca336ffcdf783682ef473e8878d7fd
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13418
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

1 files changed, 99 insertions, 0 deletions

diff --git a/src/mem/cache/replacement_policies/replaceable_entry.hh b/src/mem/cache/replacement_policies/replaceable_entry.hh
new file mode 100644
index 000000000..bf54e2264
--- /dev/null
+++ b/src/mem/cache/replacement_policies/replaceable_entry.hh
@@ -0,0 +1,99 @@
+/**
+ * Copyright (c) 2018 Inria
+ * 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
+ */
+
+#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_REPLACEABLE_ENTRY_HH__
+#define __MEM_CACHE_REPLACEMENT_POLICIES_REPLACEABLE_ENTRY_HH__
+
+#include <cstdint>
+#include <memory>
+
+/**
+ * The replacement data needed by replacement policies. Each replacement policy
+ * should have its own implementation of replacement data.
+ */
+struct ReplacementData {};
+
+/**
+ * A replaceable entry is a basic entry in a 2d table-like structure that needs
+ * to have replacement functionality. This entry is located in a specific row
+ * and column of the table (set and way in cache nomenclature), which are
+ * stored within the entry itself.
+ *
+ * It contains the replacement data pointer, which must be instantiated by the
+ * replacement policy before being used.
+ * @sa Replacement Policies
+ */
+class ReplaceableEntry
+{
+  private:
+    /**
+     * Set to which this entry belongs.
+     */
+    uint32_t _set;
+
+    /**
+     * Way (relative position within the set) to which this entry belongs.
+     */
+    uint32_t _way;
+
+   public:
+     /**
+      * Replacement data associated to this entry.
+      * It must be instantiated by the replacement policy before being used.
+      */
+     std::shared_ptr<ReplacementData> replacementData;
+
+    /**
+     * Set both the set and way. Should be called only once.
+     *
+     * @param set The set of this entry.
+     * @param way The way of this entry.
+     */
+    void setPosition(const uint32_t set, const uint32_t way) {
+        _set = set;
+        _way = way;
+    }
+
+    /**
+     * Get set number.
+     *
+     * @return The set to which this entry belongs.
+     */
+    uint32_t getSet() const { return _set; }
+
+    /**
+     * Get way number.
+     *
+     * @return The way to which this entry belongs.
+     */
+    uint32_t getWay() const { return _way; }
+};
+
+#endif // __MEM_CACHE_REPLACEMENT_POLICIES_REPLACEABLE_ENTRY_HH_