CPU: Moving towards a more general port across CPU models

This patch performs minimal changes to move the instruction and data
ports from specialised subclasses to the base CPU (to the largest
degree possible). Ultimately it servers to make the CPU(s) have a
well-defined interface to the memory sub-system.

1 files changed, 63 insertions, 0 deletions

diff --git a/src/cpu/base.hh b/src/cpu/base.hh
index 638556deb..5622031f8 100644
--- a/src/cpu/base.hh
+++ b/src/cpu/base.hh
@@ -1,4 +1,16 @@
 /*
+ * Copyright (c) 2011 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) 2002-2005 The Regents of The University of Michigan
  * Copyright (c) 2011 Regents of the University of California
  * All rights reserved.
@@ -95,6 +107,57 @@ class BaseCPU : public MemObject
     // therefore no setCpuId() method is provided
     int _cpuId;
 
+    /**
+     * Define a base class for the CPU ports (instruction and data)
+     * that is refined in the subclasses. This class handles the
+     * common cases, i.e. the functional accesses and the status
+     * changes and address range queries. The default behaviour for
+     * both atomic and timing access is to panic and the corresponding
+     * subclasses have to override these methods.
+     */
+    class CpuPort : public Port
+    {
+      public:
+
+        /**
+         * Create a CPU port with a name and a structural owner.
+         *
+         * @param _name port name including the owner
+         * @param _name structural owner of this port
+         */
+        CpuPort(const std::string& _name, MemObject* _owner) :
+            Port(_name, _owner), snoopRangeSent(false)
+        { }
+
+      protected:
+
+        virtual bool recvTiming(PacketPtr pkt);
+
+        virtual Tick recvAtomic(PacketPtr pkt);
+
+        virtual void recvRetry();
+
+        void recvFunctional(PacketPtr pkt);
+
+        void recvStatusChange(Status status);
+
+        /**
+         * Add CPU ports are master ports and do not respond to any
+         * address ranges. Note that the LSQ snoops for specific ISAs
+         * and thus has to override this method.
+         *
+         * @param resp list of ranges this port responds to
+         * @param snoop indicating if the port snoops or not
+         */
+        virtual void getDeviceAddressRanges(AddrRangeList& resp,
+                                            bool& snoop);
+
+      private:
+
+        bool snoopRangeSent;
+
+    };
+
   public:
     /** Reads this CPU's ID. */
     int cpuId() { return _cpuId; }