ruby: Fix RubyPort to properly handle retrys

src/mem/ruby/system/RubyPort.cc

@@ -49,6 +49,8 @@ RubyPort::RubyPort(const Params *p)
     m_request_cnt = 0;
     pio_port = NULL;
     physMemPort = NULL;
+
+    m_usingRubyTester = p->using_ruby_tester;
 }
 
 void
@@ -108,6 +110,7 @@ RubyPort::M5Port::M5Port(const std::string &_name,
 {
     DPRINTF(Ruby, "creating port from ruby sequcner to cpu %s\n", _name);
     ruby_port = _port;
+    _onRetryList = false;
 }
 
 Tick
@@ -256,9 +259,18 @@ RubyPort::M5Port::recvTiming(PacketPtr pkt)
     // Otherwise, we need to delete the senderStatus we just created and return
     // false.
     if (requestStatus == RequestStatus_Issued) {
+        DPRINTF(MemoryAccess, "Request %x issued\n", pkt->getAddr());
         return true;
     }
 
+    //
+    // Unless one is using the ruby tester, record the stalled M5 port for 
+    // later retry when the sequencer becomes free.
+    //
+    if (!ruby_port->m_usingRubyTester) {
+        ruby_port->addToRetryList(this);
+    }
+
     DPRINTF(MemoryAccess,
             "Request for address %#x did not issue because %s\n",
             pkt->getAddr(), RequestStatus_to_string(requestStatus));
@@ -283,6 +295,23 @@ RubyPort::ruby_hit_callback(PacketPtr pkt)
     delete senderState;
 
     port->hitCallback(pkt);
+
+    //
+    // If we had to stall the M5Ports, wake them up because the sequencer
+    // likely has free resources now.
+    //
+    if (waitingOnSequencer) {
+        for (std::list<M5Port*>::iterator i = retryList.begin();
+             i != retryList.end(); ++i) {
+            (*i)->sendRetry();
+            (*i)->onRetryList(false);
+            DPRINTF(MemoryAccess,
+                    "Sequencer may now be free.  SendRetry to port %s\n",
+                    (*i)->name());
+        }
+        retryList.clear();
+        waitingOnSequencer = false;
+    }
 }
 
 void

src/mem/ruby/system/RubyPort.hh

@@ -50,12 +50,19 @@ class RubyPort : public MemObject
     {
       private:
         RubyPort *ruby_port;
+        bool _onRetryList;
 
       public:
         M5Port(const std::string &_name, RubyPort *_port);
         bool sendTiming(PacketPtr pkt);
         void hitCallback(PacketPtr pkt);
         unsigned deviceBlockSize() const;
+        
+        bool onRetryList() 
+        { return _onRetryList; }
+        
+        void onRetryList(bool newVal)
+        { _onRetryList = newVal; }
 
       protected:
         virtual bool recvTiming(PacketPtr pkt);
@@ -118,14 +125,32 @@ class RubyPort : public MemObject
     AbstractController* m_controller;
     MessageBuffer* m_mandatory_q_ptr;
     PioPort* pio_port;
+    bool m_usingRubyTester;
 
   private:
+    void addToRetryList(M5Port * port)
+    {
+        if (!port->onRetryList()) {
+            port->onRetryList(true);
+            retryList.push_back(port);
+            waitingOnSequencer = true;
+        }
+    }
+
     uint16_t m_port_id;
     uint64_t m_request_cnt;
 
     M5Port* physMemPort;
 
     PhysicalMemory* physmem;
+
+    //
+    // Based on similar code in the M5 bus.  Stores pointers to those ports
+    // that should be called when the Sequencer becomes available after a stall.
+    //
+    std::list<M5Port*> retryList;
+
+    bool waitingOnSequencer;
 };
 
 #endif // __MEM_RUBY_SYSTEM_RUBYPORT_HH__

src/mem/ruby/system/Sequencer.cc

@@ -72,7 +72,6 @@ Sequencer::Sequencer(const Params *p)
     m_dataCache_ptr = p->dcache;
     m_max_outstanding_requests = p->max_outstanding_requests;
     m_deadlock_threshold = p->deadlock_threshold;
-    m_usingRubyTester = p->using_ruby_tester;
 
     assert(m_max_outstanding_requests > 0);
     assert(m_deadlock_threshold > 0);

src/mem/ruby/system/Sequencer.hh

@@ -152,8 +152,6 @@ class Sequencer : public RubyPort, public Consumer
     int m_load_waiting_on_store_cycles;
     int m_load_waiting_on_load_cycles;
 
-    bool m_usingRubyTester;
-
     class SequencerWakeupEvent : public Event
     {
       private:

src/mem/ruby/system/Sequencer.py

@@ -39,6 +39,7 @@ class RubyPort(MemObject):
     pio_port = Port("Ruby_pio_port")
     physmem = Param.PhysicalMemory("")
     physMemPort = Port("port to physical memory")
+    using_ruby_tester = Param.Bool(False, "")
 
 class RubySequencer(RubyPort):
     type = 'RubySequencer'
@@ -49,7 +50,6 @@ class RubySequencer(RubyPort):
         "max requests (incl. prefetches) outstanding")
     deadlock_threshold = Param.Int(500000,
         "max outstanding cycles for a request before deadlock/livelock declared")
-    using_ruby_tester = Param.Bool(False, "")
 
 class DMASequencer(RubyPort):
     type = 'DMASequencer'