inorder: update pipeline interface for handling finished resource reqs

formerly, to free up bandwidth in a resource, we could just change the pointer in that resource
but at the same time the pipeline stages had visibility to see what happened to a resource request.
Now that we are recycling these requests (to avoid too much dynamic allocation), we can't throw
away the request too early or the pipeline stage gets bad information. Instead, mark when a request
is done with the resource all together and then let the pipeline stage call back to the resource
that it's time to free up the bandwidth for more instructions
*** inteface notes ***
- When an instruction completes and is done in a resource for that cycle, call done()
- When an instruction fails and is done with a resource for that cycle, call done(false)
- When an instruction completes, but isnt finished with a resource, call completed()
- When an instruction fails, but isnt finished with a resource, call completed(false)
* * *
inorder: tlbmiss wakeup bug fix

1 files changed, 16 insertions, 4 deletions

diff --git a/src/cpu/inorder/pipeline_stage.cc b/src/cpu/inorder/pipeline_stage.cc
index 610b6f264..15f143251 100644
--- a/src/cpu/inorder/pipeline_stage.cc
+++ b/src/cpu/inorder/pipeline_stage.cc
@@ -940,7 +940,9 @@ PipelineStage::processInstSchedule(DynInstPtr inst,int &reqs_processed)
             ResReqPtr req = cpu->resPool->request(res_num, inst);
             assert(req->valid);
 
-            if (req->isCompleted()) {
+            bool req_completed = req->isCompleted();
+            bool done_in_pipeline = false;
+            if (req_completed) {
                 DPRINTF(InOrderStage, "[tid:%i]: [sn:%i] request to %s "
                         "completed.\n", tid, inst->seqNum, 
                         cpu->resPool->name(res_num));
@@ -949,11 +951,10 @@ PipelineStage::processInstSchedule(DynInstPtr inst,int &reqs_processed)
 
                 req->stagePasses++;                
 
-                bool done_in_pipeline = inst->finishSkedEntry();
+                done_in_pipeline = inst->finishSkedEntry();
                 if (done_in_pipeline) {
                     DPRINTF(InOrderDynInst, "[tid:%i]: [sn:%i] finished "
                             "in pipeline.\n", tid, inst->seqNum);
-                    break;
                 }
             } else {
                 DPRINTF(InOrderStage, "[tid:%i]: [sn:%i] request to %s failed."
@@ -990,7 +991,18 @@ PipelineStage::processInstSchedule(DynInstPtr inst,int &reqs_processed)
                             "thread due to cache miss.\n");
                     cpu->activateNextReadyContext();
                 }
-                
+            }
+
+            // If this request is no longer needs to take up bandwidth in the
+            // resource, go ahead and free that bandwidth up
+            if (req->doneInResource) {
+                req->freeSlot();
+            }
+
+            // No longer need to process this instruction if the last
+            // request it had wasn't completed or if there is nothing
+            // else for it to do in the pipeline
+            if (done_in_pipeline || !req_completed) {
                 break;
             }