7 files changed, 106 insertions, 2 deletions

diff --git a/src/arch/mips/utility.cc b/src/arch/mips/utility.cc
index f84819756..ff410bad1 100644
--- a/src/arch/mips/utility.cc
+++ b/src/arch/mips/utility.cc
@@ -241,7 +241,23 @@ initCPU(ThreadContext *tc, int cpuId)
 void
 copyRegs(ThreadContext *src, ThreadContext *dest)
 {
-    panic("Copy Regs Not Implemented Yet\n");
+    // First loop through the integer registers.
+    for (int i = 0; i < NumIntRegs; i++)
+        dest->setIntRegFlat(i, src->readIntRegFlat(i));
+
+    // Then loop through the floating point registers.
+    for (int i = 0; i < NumFloatRegs; i++)
+        dest->setFloatRegFlat(i, src->readFloatRegFlat(i));
+
+    // Would need to add condition-code regs if implemented
+    assert(NumCCRegs == 0);
+
+    // Copy misc. registers
+    for (int i = 0; i < NumMiscRegs; i++)
+        dest->setMiscRegNoEffect(i, src->readMiscRegNoEffect(i));
+
+    // Copy over the PC State
+    dest->pcState(src->pcState());
 }
 
 void
diff --git a/src/cpu/inorder/InOrderCPU.py b/src/cpu/inorder/InOrderCPU.py
index 4caf254c4..920b9cdc1 100644
--- a/src/cpu/inorder/InOrderCPU.py
+++ b/src/cpu/inorder/InOrderCPU.py
@@ -47,6 +47,10 @@ class InOrderCPU(BaseCPU):
     def require_caches(cls):
         return True
 
+    @classmethod
+    def support_take_over(cls):
+        return True
+
     threadModel = Param.ThreadModel('SMT', "Multithreading model (SE-MODE only)")
     
     cachePorts = Param.Unsigned(2, "Cache Ports")
diff --git a/src/cpu/inorder/cpu.cc b/src/cpu/inorder/cpu.cc
index 5a02f94d9..eecbd033e 100644
--- a/src/cpu/inorder/cpu.cc
+++ b/src/cpu/inorder/cpu.cc
@@ -64,6 +64,7 @@
 #include "cpu/simple_thread.hh"
 #include "cpu/thread_context.hh"
 #include "debug/Activity.hh"
+#include "debug/Drain.hh"
 #include "debug/InOrderCPU.hh"
 #include "debug/InOrderCachePort.hh"
 #include "debug/Interrupt.hh"
@@ -1490,6 +1491,67 @@ InOrderCPU::updateContextSwitchStats()
     instsPerSwitch = 0;
 }
 
+
+void
+InOrderCPU::drainResume()
+{
+    setDrainState(Drainable::Running);
+    if (switchedOut())
+        return;
+
+    DPRINTF(Drain, "Resuming...\n");
+    verifyMemoryMode();
+
+    assert(!tickEvent.scheduled());
+
+    // Activate threads and also signal the resource pool to activate
+    // the thread on all resources.
+    _status = Idle;
+    for (ThreadID i = 0; i < thread.size(); i++) {
+        if (thread[i]->status() == ThreadContext::Active) {
+            DPRINTF(Drain, "Activating thread: %i\n", i);
+            activateThread(i);
+            resPool->activateThread(i);
+            _status = Running;
+        }
+    }
+}
+
+void
+InOrderCPU::switchOut()
+{
+    DPRINTF(InOrderCPU, "Switching out\n");
+    BaseCPU::switchOut();
+
+    activityRec.reset();
+
+    _status = SwitchedOut;
+}
+
+void
+InOrderCPU::takeOverFrom(BaseCPU *oldCPU)
+{
+    BaseCPU::takeOverFrom(oldCPU);
+
+    // Call takeOverFrom() on each pipeline stage
+    for (int stNum=0; stNum < NumStages; stNum++) {
+        pipelineStage[stNum]->takeOverFrom();
+    }
+
+    assert(!tickEvent.scheduled());
+
+    // Copy over the current instruction sequence numbers if we are
+    // taking over from another InOrderCPU.
+    InOrderCPU *oldIOCPU = dynamic_cast<InOrderCPU*>(oldCPU);
+    if (oldIOCPU) {
+      for (ThreadID tid = 0; tid < numThreads; tid++)
+        globalSeqNum[tid] = oldIOCPU->globalSeqNum[tid];
+    }
+
+    lastRunningCycle = curCycle();
+    _status = Idle;
+}
+
     
 void
 InOrderCPU::instDone(DynInstPtr inst, ThreadID tid)
diff --git a/src/cpu/inorder/cpu.hh b/src/cpu/inorder/cpu.hh
index 1183f6fc9..0104cb95f 100644
--- a/src/cpu/inorder/cpu.hh
+++ b/src/cpu/inorder/cpu.hh
@@ -866,6 +866,15 @@ class InOrderCPU : public BaseCPU
     Stats::Average instsPerCtxtSwitch;    
     Stats::Scalar numCtxtSwitches;
     
+    /** Resumes execution after a drain. */
+    void drainResume();
+
+    /** Switches out this CPU. */
+    virtual void switchOut();
+
+    /** Takes over from another CPU. */
+    virtual void takeOverFrom(BaseCPU *oldCPU);
+
     /** Update Thread , used for statistic purposes*/
     inline void tickThreadStats();
 
diff --git a/src/cpu/inorder/first_stage.cc b/src/cpu/inorder/first_stage.cc
index 20fd9169f..f59e89410 100644
--- a/src/cpu/inorder/first_stage.cc
+++ b/src/cpu/inorder/first_stage.cc
@@ -277,3 +277,13 @@ FirstStage::roundRobin()
 
     return InvalidThreadID;
 }
+
+void
+FirstStage::takeOverFrom()
+{
+    PipelineStage::takeOverFrom();
+
+    for(ThreadID tid = 0; tid < this->numThreads; tid++) {
+        stageStatus[tid] = Running;
+    }
+}
diff --git a/src/cpu/inorder/first_stage.hh b/src/cpu/inorder/first_stage.hh
index 44ffb9599..ae8b12102 100644
--- a/src/cpu/inorder/first_stage.hh
+++ b/src/cpu/inorder/first_stage.hh
@@ -88,6 +88,9 @@ class FirstStage : public PipelineStage {
 
     /** Return next thread given Round Robin Policy for Thread Fetching */
     ThreadID roundRobin();
+
+    /** Takes over from another CPU's thread. */
+    void takeOverFrom();
 };
 
 #endif // __CPU_INORDER_FIRST_STAGE_HH__
diff --git a/src/cpu/inorder/pipeline_stage.hh b/src/cpu/inorder/pipeline_stage.hh
index 963d96afb..478561a8e 100644
--- a/src/cpu/inorder/pipeline_stage.hh
+++ b/src/cpu/inorder/pipeline_stage.hh
@@ -135,7 +135,7 @@ class PipelineStage
     void switchOut();
 
     /** Takes over from another CPU's thread. */
-    void takeOverFrom();
+    virtual void takeOverFrom();
 
     /** Ticks stage, processing all input signals and executing as many
      *  instructions as possible.