base: Allow DPRINTF debugging of AssociativeCache (#1514)

The AssociativeCache is used by different caching agents.
This PR will allow to pass the appropriate flag to the cache so that we
can meaningfully debug
its internals. For instance, when used to model a prefetcher table, will
will pass the
HWPrefetch flag; when used to model a TLB, we will pass the TLB flag.

src/base/cache/associative_cache.hh

@@ -81,6 +81,8 @@ class AssociativeCache : public Named
     /** The entries */
     std::vector<Entry> entries;
 
+    const ::gem5::debug::SimpleFlag* debugFlag = nullptr;
+
   private:
 
     void
@@ -120,7 +122,8 @@ class AssociativeCache : public Named
           associativity(associativity_),
           replPolicy(repl_policy),
           indexingPolicy(indexing_policy),
-          entries(num_entries, init_val)
+          entries(num_entries, init_val),
+          debugFlag(nullptr)
     {
         initParams(num_entries, associativity);
     }
@@ -162,6 +165,12 @@ class AssociativeCache : public Named
         initParams(num_entries, associativity);
     }
 
+    void
+    setDebugFlag(const ::gem5::debug::SimpleFlag& flag)
+    {
+        debugFlag = &flag;
+    }
+
     /**
      * Do an access to the entry if it exists.
      * This is required to update the replacement information data.
@@ -223,6 +232,12 @@ class AssociativeCache : public Named
 
         auto victim = static_cast<Entry*>(replPolicy->getVictim(candidates));
 
+        if (debugFlag && debugFlag->tracing() && victim->isValid()) {
+            ::gem5::trace::getDebugLogger()->dprintf_flag(
+                curTick(), name(), debugFlag->name(),
+                "Replacing entry: %s\n", victim->print());
+        }
+
         invalidate(victim);
 
         return victim;
@@ -248,6 +263,12 @@ class AssociativeCache : public Named
     virtual void
     insertEntry(const KeyType &key, Entry *entry)
     {
+        if (debugFlag && debugFlag->tracing()) {
+            ::gem5::trace::getDebugLogger()->dprintf_flag(
+                curTick(), name(), debugFlag->name(),
+                "Inserting entry: %s\n", entry->print());
+        }
+
         entry->insert(key);
         replPolicy->reset(entry->replacementData);
     }