Support for draining, and the new method of switching out. Now switching out happens after the pipeline has been drained, deferring the three way handshake to the normal drain mechanism. The calls of switchOut() and takeOverFrom() both take action immediately.

src/cpu/o3/commit.hh:
src/cpu/o3/commit_impl.hh:
src/cpu/o3/cpu.cc:
src/cpu/o3/cpu.hh:
src/cpu/o3/decode.hh:
src/cpu/o3/decode_impl.hh:
src/cpu/o3/fetch.hh:
src/cpu/o3/fetch_impl.hh:
src/cpu/o3/iew.hh:
src/cpu/o3/iew_impl.hh:
src/cpu/o3/rename.hh:
src/cpu/o3/rename_impl.hh:
    Support for draining, new method of switching out.

--HG--
extra : convert_revision : 05bf8b271ec85b3e2c675c3bed6c42aeba21f465

1 files changed, 52 insertions, 25 deletions

diff --git a/src/cpu/o3/cpu.cc b/src/cpu/o3/cpu.cc
index fb7739db8..5bda57cf8 100644
--- a/src/cpu/o3/cpu.cc
+++ b/src/cpu/o3/cpu.cc
@@ -158,7 +158,7 @@ FullO3CPU<Impl>::FullO3CPU(Params *params)
       physmem(system->physmem),
 #endif // FULL_SYSTEM
       mem(params->mem),
-      switchCount(0),
+      drainCount(0),
       deferRegistration(params->deferRegistration),
       numThreads(number_of_threads)
 {
@@ -713,45 +713,72 @@ FullO3CPU<Impl>::haltContext(int tid)
 }
 
 template <class Impl>
-void
-FullO3CPU<Impl>::switchOut()
+bool
+FullO3CPU<Impl>::drain(Event *drain_event)
 {
-    switchCount = 0;
-    fetch.switchOut();
-    decode.switchOut();
-    rename.switchOut();
-    iew.switchOut();
-    commit.switchOut();
+    drainCount = 0;
+    drainEvent = drain_event;
+    fetch.drain();
+    decode.drain();
+    rename.drain();
+    iew.drain();
+    commit.drain();
 
     // Wake the CPU and record activity so everything can drain out if
     // the CPU is currently idle.
     wakeCPU();
     activityRec.activity();
+
+    return false;
 }
 
 template <class Impl>
 void
-FullO3CPU<Impl>::signalSwitched()
-{
-    if (++switchCount == NumStages) {
-        fetch.doSwitchOut();
-        rename.doSwitchOut();
-        commit.doSwitchOut();
-        instList.clear();
-        while (!removeList.empty()) {
-            removeList.pop();
-        }
+FullO3CPU<Impl>::resume()
+{
+    if (_status == SwitchedOut)
+        return;
+    fetch.resume();
+    decode.resume();
+    rename.resume();
+    iew.resume();
+    commit.resume();
 
-#if USE_CHECKER
-        if (checker)
-            checker->switchOut();
-#endif
+    if (!tickEvent.scheduled())
+        tickEvent.schedule(curTick);
+    _status = Running;
+}
 
+template <class Impl>
+void
+FullO3CPU<Impl>::signalDrained()
+{
+    if (++drainCount == NumStages) {
         if (tickEvent.scheduled())
             tickEvent.squash();
-        _status = SwitchedOut;
+        _status = Drained;
+        drainEvent->process();
     }
-    assert(switchCount <= 5);
+    assert(drainCount <= 5);
+}
+
+template <class Impl>
+void
+FullO3CPU<Impl>::switchOut()
+{
+    fetch.switchOut();
+    rename.switchOut();
+    commit.switchOut();
+    instList.clear();
+    while (!removeList.empty()) {
+        removeList.pop();
+    }
+
+    _status = SwitchedOut;
+#if USE_CHECKER
+    if (checker)
+        checker->switchOut();
+#endif
 }
 
 template <class Impl>