inorder: ready thread wakeup

allow a thread to wakeup and be activated after
it has been in suspended state and another
thread is switched out. Need to give
pipeline stages a "activateThread" function
so that can get to their suspended instruction
when the time is right.

5 files changed, 51 insertions, 3 deletions

diff --git a/src/cpu/inorder/cpu.cc b/src/cpu/inorder/cpu.cc
index ec6bb21ee..501150386 100644
--- a/src/cpu/inorder/cpu.cc
+++ b/src/cpu/inorder/cpu.cc
@@ -674,6 +674,8 @@ InOrderCPU::activateNextReadyThread()
         DPRINTF(InOrderCPU,
                 "Attempting to activate new thread, but No Ready Threads to"
                 "activate.\n");
+        DPRINTF(InOrderCPU,
+                "Unable to switch to next active thread.\n");
     }        
 }
 
@@ -696,7 +698,7 @@ InOrderCPU::activateThread(ThreadID tid)
                 "Ignoring activation of [tid:%i], since [tid:%i] is "
                 "already running.\n", tid, activeThreadId());
         
-        DPRINTF(InOrderCPU,"Placing [tid:%i] ready threads list\n", 
+        DPRINTF(InOrderCPU,"Placing [tid:%i] on ready threads list\n", 
                 tid);        
 
         readyThreads.push_back(tid);
@@ -706,11 +708,21 @@ InOrderCPU::activateThread(ThreadID tid)
                 "Adding [tid:%i] to active threads list.\n", tid);
         activeThreads.push_back(tid);
         
+        activateThreadInPipeline(tid);
+        
         wakeCPU();
     }
 }
 
 void
+InOrderCPU::activateThreadInPipeline(ThreadID tid)
+{
+    for (int stNum=0; stNum < NumStages; stNum++) {
+        pipelineStage[stNum]->activateThread(tid);
+    }    
+}
+
+void
 InOrderCPU::deactivateContext(ThreadID tid, int delay)
 {
     DPRINTF(InOrderCPU,"[tid:%i]: Deactivating ...\n", tid);
diff --git a/src/cpu/inorder/cpu.hh b/src/cpu/inorder/cpu.hh
index 7ac433723..1e514e1ed 100644
--- a/src/cpu/inorder/cpu.hh
+++ b/src/cpu/inorder/cpu.hh
@@ -346,7 +346,8 @@ class InOrderCPU : public BaseCPU
     /** Add Thread to Active Threads List. */
     void activateContext(ThreadID tid, int delay = 0);
     void activateThread(ThreadID tid);
-
+    void activateThreadInPipeline(ThreadID tid);
+    
     /** Add Thread to Active Threads List. */
     void activateNextReadyContext(int delay = 0);
     void activateNextReadyThread();
diff --git a/src/cpu/inorder/pipeline_stage.cc b/src/cpu/inorder/pipeline_stage.cc
index 30a3733b0..ef91f206b 100644
--- a/src/cpu/inorder/pipeline_stage.cc
+++ b/src/cpu/inorder/pipeline_stage.cc
@@ -558,6 +558,28 @@ PipelineStage::updateStatus()
     }
 }
 
+void 
+PipelineStage::activateThread(ThreadID tid)
+{    
+    if (cpu->threadModel == InOrderCPU::SwitchOnCacheMiss) {
+        if (!switchedOutValid[tid]) {
+            DPRINTF(InOrderStage, "[tid:%i] No instruction available in "
+                    "switch out buffer.\n", tid);        
+        } else {
+            DynInstPtr inst = switchedOutBuffer[tid];
+
+            DPRINTF(InOrderStage,"[tid:%i]: Re-Inserting [sn:%lli] PC:%#x into stage skidBuffer %i\n",
+                    tid, inst->seqNum, inst->readPC(), inst->threadNumber);
+
+            skidBuffer[tid].push(inst);            
+
+            switchedOutBuffer[tid] = NULL;
+
+            switchedOutValid[tid] = false;            
+        }        
+    }
+    
+}
 
 
 void
@@ -945,6 +967,11 @@ PipelineStage::processInstSchedule(DynInstPtr inst)
                 if (req->isMemStall() && 
                     cpu->threadModel == InOrderCPU::SwitchOnCacheMiss) {
                     // Save Stalling Instruction
+                    DPRINTF(ThreadModel, "[tid:%i] Detected cache miss.\n", tid);
+
+                    DPRINTF(InOrderStage, "Inserting [tid:%i][sn:%i] into switch out buffer.\n",
+                             tid, inst->seqNum);                    
+
                     switchedOutBuffer[tid] = inst;
                     switchedOutValid[tid] = true;
                     
@@ -956,9 +983,12 @@ PipelineStage::processInstSchedule(DynInstPtr inst)
                     // Switch On Cache Miss
                     //=====================
                     // Suspend Thread at end of cycle
+                    DPRINTF(ThreadModel, "Suspending [tid:%i] due to cache miss.\n", tid);
                     cpu->suspendContext(tid);                    
 
                     // Activate Next Ready Thread at end of cycle
+                    DPRINTF(ThreadModel, "Attempting to activate next ready thread due to"
+                            " cache miss.\n");
                     cpu->activateNextReadyContext();                                                                                               
                 }
                 
diff --git a/src/cpu/inorder/pipeline_stage.hh b/src/cpu/inorder/pipeline_stage.hh
index f10906e4c..dfe1ac7c3 100644
--- a/src/cpu/inorder/pipeline_stage.hh
+++ b/src/cpu/inorder/pipeline_stage.hh
@@ -235,6 +235,8 @@ class PipelineStage
 
 
   public:
+    virtual void activateThread(ThreadID tid);
+    
     /** Squashes if there is a PC-relative branch that was predicted
      * incorrectly. Sends squash information back to fetch.
      */
diff --git a/src/cpu/inorder/resources/cache_unit.cc b/src/cpu/inorder/resources/cache_unit.cc
index 3de5c518a..2cf6c3195 100644
--- a/src/cpu/inorder/resources/cache_unit.cc
+++ b/src/cpu/inorder/resources/cache_unit.cc
@@ -708,9 +708,12 @@ CacheUnit::processCacheCompletion(PacketPtr pkt)
 
         if (cache_req->isMemStall() && 
             cpu->threadModel == InOrderCPU::SwitchOnCacheMiss) {    
-            DPRINTF(InOrderCachePort, "[tid:%u] Waking up from Cache Miss.\n");
+            DPRINTF(InOrderCachePort, "[tid:%u] Waking up from Cache Miss.\n", tid);
             
             cpu->activateContext(tid);            
+            
+            DPRINTF(ThreadModel, "Activating [tid:%i] after return from cache"
+                    "miss.\n", tid);            
         }
         
         // Wake up the CPU (if it went to sleep and was waiting on this