mem: Split the various protocols out of the gem5 master/slave ports.

This makes the protocols easier to see in their entirity, and makes it
easier to add a new type of port which only supports the functional
protocol.

Change-Id: If5d639bef45062f0a23af2ac46f50933e6a8f144
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20228
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

1 files changed, 92 insertions, 0 deletions

diff --git a/src/mem/functional_protocol.hh b/src/mem/functional_protocol.hh
new file mode 100644
index 000000000..443b98032
--- /dev/null
+++ b/src/mem/functional_protocol.hh
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2011-2012,2015,2017 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) 2002-2005 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.
+ *
+ * Authors: Ron Dreslinski
+ *          Andreas Hansson
+ *          William Wang
+ */
+
+#ifndef __MEM_FUNCTIONAL_PROTOCOL_HH__
+#define __MEM_FUNCTIONAL_PROTOCOL_HH__
+
+#include "mem/packet.hh"
+
+class FunctionalResponseProtocol;
+
+class FunctionalRequestProtocol
+{
+    friend class FunctionalResponseProtocol;
+
+  protected:
+    /**
+     * Send a functional request packet, where the data is instantly
+     * updated everywhere in the memory system, without affecting the
+     * current state of any block or moving the block.
+     *
+     * @param pkt Packet to send.
+     */
+    void send(FunctionalResponseProtocol *peer, PacketPtr pkt) const;
+
+    /**
+     * Receive a functional snoop request packet from the peer.
+     */
+    virtual void recvFunctionalSnoop(PacketPtr pkt) = 0;
+};
+
+class FunctionalResponseProtocol
+{
+    friend class FunctionalRequestProtocol;
+
+  protected:
+    /**
+     * Send a functional snoop request packet, where the data is
+     * instantly updated everywhere in the memory system, without
+     * affecting the current state of any block or moving the block.
+     *
+     * @param pkt Snoop packet to send.
+     */
+    void sendSnoop(FunctionalRequestProtocol *peer, PacketPtr pkt) const;
+
+    /**
+     * Receive a functional request packet from the peer.
+     */
+    virtual void recvFunctional(PacketPtr pkt) = 0;
+};
+
+#endif //__MEM_FUNCTIONAL_PROTOCOL_HH__