systemc: Provide a utility Port TLM socket wrapper class.

This class should make it easy to attach TLM sockets into the gem5
python Port config mechanism.

Change-Id: I3548c654d56bfc852f3fc98fe6433163b14f7fe3
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/17230
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/systemc/tlm_port_wrapper.hh

@@ -0,0 +1,124 @@
+/*
+ * Copyright 2018 Google, Inc.
+ *
+ * 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: Gabe Black
+ */
+
+#ifndef __SYSTEMC_TLM_PORT_WRAPPER_HH__
+#define __SYSTEMC_TLM_PORT_WRAPPER_HH__
+
+#include "base/logging.hh"
+#include "sim/port.hh"
+#include "systemc/ext/tlm_core/2/sockets/sockets.hh"
+
+namespace sc_gem5
+{
+
+template <unsigned int BUSWIDTH=32,
+          typename TYPES=tlm::tlm_base_protocol_types, int N=1,
+          sc_core::sc_port_policy POL=sc_core::SC_ONE_OR_MORE_BOUND>
+class TlmInitiatorWrapper;
+
+template <unsigned int BUSWIDTH=32,
+          typename TYPES=tlm::tlm_base_protocol_types, int N=1,
+          sc_core::sc_port_policy POL=sc_core::SC_ONE_OR_MORE_BOUND>
+class TlmTargetWrapper;
+
+template <unsigned int BUSWIDTH, typename TYPES, int N,
+          sc_core::sc_port_policy POL>
+class TlmInitiatorWrapper : public ::Port
+{
+  public:
+    typedef tlm::tlm_base_initiator_socket<BUSWIDTH,
+            tlm::tlm_fw_transport_if<TYPES>,
+            tlm::tlm_bw_transport_if<TYPES>, N, POL>
+        InitiatorSocket;
+    typedef typename InitiatorSocket::base_target_socket_type TargetSocket;
+    typedef TlmTargetWrapper<BUSWIDTH, TYPES, N, POL> TargetWrapper;
+
+    InitiatorSocket &initiator() { return _initiator; }
+
+    TlmInitiatorWrapper(
+            InitiatorSocket &i, const std::string &_name, PortID _id) :
+        Port(_name, _id), _initiator(i)
+    {}
+
+    void
+    bind(::Port &peer) override
+    {
+        auto *target = dynamic_cast<TargetWrapper *>(&peer);
+        fatal_if(!target, "Attempt to bind TLM initiator socket %s to "
+                "incompatible port %s.", name(), peer.name());
+
+        initiator().bind(target->target());
+    }
+
+    void
+    unbind() override
+    {
+        panic("TLM sockets can't be unbound.");
+    }
+
+  private:
+    InitiatorSocket &_initiator;
+};
+
+template <unsigned int BUSWIDTH, typename TYPES, int N,
+          sc_core::sc_port_policy POL>
+class TlmTargetWrapper : public ::Port
+{
+  public:
+    typedef tlm::tlm_base_target_socket<BUSWIDTH,
+            tlm::tlm_fw_transport_if<TYPES>,
+            tlm::tlm_bw_transport_if<TYPES>, N, POL>
+        TargetSocket;
+
+    TargetSocket &target() { return _target; }
+
+    TlmTargetWrapper(TargetSocket &t, const std::string &_name, PortID _id) :
+        Port(_name, _id), _target(t)
+    {}
+
+    void
+    bind(::Port &peer) override
+    {
+        // Ignore attempts to bind a target socket. The initiator will
+        // handle it.
+    }
+
+    void
+    unbind() override
+    {
+        panic("TLM sockets can't be unbound.");
+    }
+
+  private:
+    TargetSocket &_target;
+};
+
+} // namespace sc_gem5
+
+#endif  //__SYSTEMC_TLM_PORT_WRAPPER_HH__