Enforce the timing cpu ticking at it's clock rate

Add a max time option in seconds and a single system root clock be 1THz

configs/test/fs.py:
    Add a max time option in seconds and a single system root clock be 1THz
src/cpu/simple/timing.cc:
src/cpu/simple/timing.hh:
    Enforce the timing cpu ticking at it's clock rate

--HG--
extra : convert_revision : a1b0de27abde867f9c3da5bec11639e3d82a95f5

2 files changed, 82 insertions, 9 deletions

diff --git a/src/cpu/simple/timing.cc b/src/cpu/simple/timing.cc
index 246bcec05..5c1654f7e 100644
--- a/src/cpu/simple/timing.cc
+++ b/src/cpu/simple/timing.cc
@@ -85,8 +85,16 @@ TimingSimpleCPU::CpuPort::recvStatusChange(Status status)
     panic("TimingSimpleCPU doesn't expect recvStatusChange callback!");
 }
 
+
+void
+TimingSimpleCPU::CpuPort::TickEvent::schedule(Packet *_pkt, Tick t)
+{
+    pkt = _pkt;
+    Event::schedule(t);
+}
+
 TimingSimpleCPU::TimingSimpleCPU(Params *p)
-    : BaseSimpleCPU(p), icachePort(this), dcachePort(this)
+    : BaseSimpleCPU(p), icachePort(this, p->clock), dcachePort(this, p->clock)
 {
     _status = Idle;
     ifetch_pkt = dcache_pkt = NULL;
@@ -462,11 +470,26 @@ TimingSimpleCPU::completeIfetch(Packet *pkt)
     }
 }
 
+void
+TimingSimpleCPU::IcachePort::ITickEvent::process()
+{
+    cpu->completeIfetch(pkt);
+}
 
 bool
 TimingSimpleCPU::IcachePort::recvTiming(Packet *pkt)
 {
-    cpu->completeIfetch(pkt);
+    // These next few lines could be replaced with something faster
+    // who knows what though
+    Tick time = pkt->req->getTime();
+    while (time < curTick)
+        time += lat;
+
+    if (time == curTick)
+        cpu->completeIfetch(pkt);
+    else
+        tickEvent.schedule(pkt, time);
+
     return true;
 }
 
@@ -523,11 +546,25 @@ TimingSimpleCPU::completeDrain()
 bool
 TimingSimpleCPU::DcachePort::recvTiming(Packet *pkt)
 {
-    cpu->completeDataAccess(pkt);
+    Tick time = pkt->req->getTime();
+    while (time < curTick)
+        time += lat;
+
+    if (time == curTick)
+        cpu->completeDataAccess(pkt);
+    else
+        tickEvent.schedule(pkt, time);
+
     return true;
 }
 
 void
+TimingSimpleCPU::DcachePort::DTickEvent::process()
+{
+    cpu->completeDataAccess(pkt);
+}
+
+void
 TimingSimpleCPU::DcachePort::recvRetry()
 {
     // we shouldn't get a retry unless we have a packet that we're
diff --git a/src/cpu/simple/timing.hh b/src/cpu/simple/timing.hh
index ac36e5c99..d03fa4bc0 100644
--- a/src/cpu/simple/timing.hh
+++ b/src/cpu/simple/timing.hh
@@ -74,11 +74,12 @@ class TimingSimpleCPU : public BaseSimpleCPU
     {
       protected:
         TimingSimpleCPU *cpu;
+        Tick lat;
 
       public:
 
-        CpuPort(const std::string &_name, TimingSimpleCPU *_cpu)
-            : Port(_name), cpu(_cpu)
+        CpuPort(const std::string &_name, TimingSimpleCPU *_cpu, Tick _lat)
+            : Port(_name), cpu(_cpu), lat(_lat)
         { }
 
       protected:
@@ -92,14 +93,26 @@ class TimingSimpleCPU : public BaseSimpleCPU
         virtual void getDeviceAddressRanges(AddrRangeList &resp,
             AddrRangeList &snoop)
         { resp.clear(); snoop.clear(); }
+
+        struct TickEvent : public Event
+        {
+            Packet *pkt;
+            TimingSimpleCPU *cpu;
+
+            TickEvent(TimingSimpleCPU *_cpu)
+                :Event(&mainEventQueue), cpu(_cpu) {}
+            const char *description() { return "Timing CPU clock event"; }
+            void schedule(Packet *_pkt, Tick t);
+        };
+
     };
 
     class IcachePort : public CpuPort
     {
       public:
 
-        IcachePort(TimingSimpleCPU *_cpu)
-            : CpuPort(_cpu->name() + "-iport", _cpu)
+        IcachePort(TimingSimpleCPU *_cpu, Tick _lat)
+            : CpuPort(_cpu->name() + "-iport", _cpu, _lat), tickEvent(_cpu)
         { }
 
       protected:
@@ -107,14 +120,26 @@ class TimingSimpleCPU : public BaseSimpleCPU
         virtual bool recvTiming(Packet *pkt);
 
         virtual void recvRetry();
+
+        struct ITickEvent : public TickEvent
+        {
+
+            ITickEvent(TimingSimpleCPU *_cpu)
+                : TickEvent(_cpu) {}
+            void process();
+            const char *description() { return "Timing CPU clock event"; }
+        };
+
+        ITickEvent tickEvent;
+
     };
 
     class DcachePort : public CpuPort
     {
       public:
 
-        DcachePort(TimingSimpleCPU *_cpu)
-            : CpuPort(_cpu->name() + "-dport", _cpu)
+        DcachePort(TimingSimpleCPU *_cpu, Tick _lat)
+            : CpuPort(_cpu->name() + "-dport", _cpu, _lat), tickEvent(_cpu)
         { }
 
       protected:
@@ -122,6 +147,17 @@ class TimingSimpleCPU : public BaseSimpleCPU
         virtual bool recvTiming(Packet *pkt);
 
         virtual void recvRetry();
+
+        struct DTickEvent : public TickEvent
+        {
+            DTickEvent(TimingSimpleCPU *_cpu)
+                : TickEvent(_cpu) {}
+            void process();
+            const char *description() { return "Timing CPU clock event"; }
+        };
+
+        DTickEvent tickEvent;
+
     };
 
     IcachePort icachePort;