systemc: Partially implement the scheduler.

This change implements the "evaluate" part of the delta cycles, and
sketches out a function to run delta cycles and the initialization
phase. The kernel object now schedules an event at time zero which
runs the initialization phase.

Also, some small places which were stubbed out pending a way to check
the currently running process have been filled in now that that's
being tracked.

Change-Id: I6899569eb0195ff1c059fa4e68e90ef162b2f2df
Reviewed-on: https://gem5-review.googlesource.com/11709
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

1 files changed, 113 insertions, 0 deletions

diff --git a/src/systemc/core/list.hh b/src/systemc/core/list.hh
new file mode 100644
index 000000000..65eada27d
--- /dev/null
+++ b/src/systemc/core/list.hh
@@ -0,0 +1,113 @@
+/*
+ * 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_CORE_LIST_HH__
+#define __SYSTEMC_CORE_LIST_HH__
+
+#include <functional>
+
+#include "base/fiber.hh"
+#include "systemc/core/object.hh"
+#include "systemc/ext/core/sc_event.hh"
+#include "systemc/ext/core/sc_module.hh"
+#include "systemc/ext/core/sc_process_handle.hh"
+
+namespace sc_gem5
+{
+
+struct ListNode
+{
+    ListNode() : nextListNode(nullptr), prevListNode(nullptr) {}
+    virtual ~ListNode() {}
+
+    ListNode *nextListNode;
+    ListNode *prevListNode;
+
+    void
+    popListNode()
+    {
+        if (nextListNode)
+            nextListNode->prevListNode = prevListNode;
+        if (prevListNode)
+            prevListNode->nextListNode = nextListNode;
+        nextListNode = nullptr;
+        prevListNode = nullptr;
+    }
+};
+
+template <typename T>
+struct NodeList : public ListNode
+{
+    NodeList()
+    {
+        nextListNode = this;
+        prevListNode = this;
+    }
+
+    void
+    pushFirst(T *t)
+    {
+        // Make sure this node isn't currently in a different list.
+        t->popListNode();
+
+        // The node behind t is whoever used to be first.
+        t->nextListNode = nextListNode;
+        // The node that used to be first is behind t.
+        nextListNode->prevListNode = t;
+
+        // Nobody is in front of t.
+        t->prevListNode = this;
+        // The first node is t.
+        nextListNode = t;
+    }
+
+    void
+    pushLast(T *t)
+    {
+        // Make sure this node isn't currently in a different list.
+        t->popListNode();
+
+        // The node in front of t is whoever used to be last.
+        t->prevListNode = prevListNode;
+        // The node that used to be last is in front of t.
+        prevListNode->nextListNode = t;
+
+        // Nobody is behind t.
+        t->nextListNode = this;
+        // The last node is t.
+        prevListNode = t;
+    }
+
+    T *getNext() { return dynamic_cast<T *>(nextListNode); }
+    bool empty() { return getNext() == nullptr; }
+};
+
+} // namespace sc_gem5
+
+#endif  //__SYSTEMC_CORE_LIST_HH__