inorder: fix squash bug in branch predictor
[gem5.git] / src / cpu / simple / atomic.cc
index 9f574e8beeaf362b901e16e5ced7ee5d02d423d2..05b4ca3e210bd3118364c498cef8add2ad08bc02 100644 (file)
@@ -32,6 +32,7 @@
 #include "arch/mmaped_ipr.hh"
 #include "arch/utility.hh"
 #include "base/bigint.hh"
+#include "config/the_isa.hh"
 #include "cpu/exetrace.hh"
 #include "cpu/simple/atomic.hh"
 #include "mem/packet.hh"
@@ -43,7 +44,7 @@ using namespace std;
 using namespace TheISA;
 
 AtomicSimpleCPU::TickEvent::TickEvent(AtomicSimpleCPU *c)
-    : Event(&mainEventQueue, CPU_Tick_Pri), cpu(c)
+    : Event(CPU_Tick_Pri), cpu(c)
 {
 }
 
@@ -55,13 +56,13 @@ AtomicSimpleCPU::TickEvent::process()
 }
 
 const char *
-AtomicSimpleCPU::TickEvent::description()
+AtomicSimpleCPU::TickEvent::description() const
 {
     return "AtomicSimpleCPU tick";
 }
 
 Port *
-AtomicSimpleCPU::getPort(const std::string &if_name, int idx)
+AtomicSimpleCPU::getPort(const string &if_name, int idx)
 {
     if (if_name == "dcache_port")
         return &dcachePort;
@@ -80,11 +81,12 @@ AtomicSimpleCPU::init()
 {
     BaseCPU::init();
 #if FULL_SYSTEM
-    for (int i = 0; i < threadContexts.size(); ++i) {
+    ThreadID size = threadContexts.size();
+    for (ThreadID i = 0; i < size; ++i) {
         ThreadContext *tc = threadContexts[i];
 
         // initialize CPU, including PC
-        TheISA::initCPU(tc, tc->readCpuId());
+        TheISA::initCPU(tc, tc->contextId());
     }
 #endif
     if (hasPhysMemPort) {
@@ -93,6 +95,10 @@ AtomicSimpleCPU::init()
         physmemPort.getPeerAddressRanges(pmAddrList, snoop);
         physMemAddr = *pmAddrList.begin();
     }
+    // Atomic doesn't do MT right now, so contextId == threadId
+    ifetch_req.setThreadContext(_cpuId, 0); // Add thread ID if we add MT
+    data_read_req.setThreadContext(_cpuId, 0); // Add thread ID here too
+    data_write_req.setThreadContext(_cpuId, 0); // Add thread ID here too
 }
 
 bool
@@ -144,13 +150,14 @@ AtomicSimpleCPU::DcachePort::setPeer(Port *port)
 #if FULL_SYSTEM
     // Update the ThreadContext's memory ports (Functional/Virtual
     // Ports)
-    cpu->tcBase()->connectMemPorts();
+    cpu->tcBase()->connectMemPorts(cpu->tcBase());
 #endif
 }
 
-AtomicSimpleCPU::AtomicSimpleCPU(Params *p)
-    : BaseSimpleCPU(p), tickEvent(this),
-      width(p->width), simulate_stalls(p->simulate_stalls),
+AtomicSimpleCPU::AtomicSimpleCPU(AtomicSimpleCPUParams *p)
+    : BaseSimpleCPU(p), tickEvent(this), width(p->width), locked(false),
+      simulate_data_stalls(p->simulate_data_stalls),
+      simulate_inst_stalls(p->simulate_inst_stalls),
       icachePort(name() + "-iport", this), dcachePort(name() + "-iport", this),
       physmemPort(name() + "-iport", this), hasPhysMemPort(false)
 {
@@ -159,14 +166,14 @@ AtomicSimpleCPU::AtomicSimpleCPU(Params *p)
     icachePort.snoopRangeSent = false;
     dcachePort.snoopRangeSent = false;
 
-    ifetch_req.setThreadContext(cpuId, 0); // Add thread ID if we add MT
-    data_read_req.setThreadContext(cpuId, 0); // Add thread ID here too
-    data_write_req.setThreadContext(cpuId, 0); // Add thread ID here too
 }
 
 
 AtomicSimpleCPU::~AtomicSimpleCPU()
 {
+    if (tickEvent.scheduled()) {
+        deschedule(tickEvent);
+    }
 }
 
 void
@@ -174,8 +181,7 @@ AtomicSimpleCPU::serialize(ostream &os)
 {
     SimObject::State so_state = SimObject::getState();
     SERIALIZE_ENUM(so_state);
-    Status _status = status();
-    SERIALIZE_ENUM(_status);
+    SERIALIZE_SCALAR(locked);
     BaseSimpleCPU::serialize(os);
     nameOut(os, csprintf("%s.tickEvent", name()));
     tickEvent.serialize(os);
@@ -186,7 +192,7 @@ AtomicSimpleCPU::unserialize(Checkpoint *cp, const string &section)
 {
     SimObject::State so_state;
     UNSERIALIZE_ENUM(so_state);
-    UNSERIALIZE_ENUM(_status);
+    UNSERIALIZE_SCALAR(locked);
     BaseSimpleCPU::unserialize(cp, section);
     tickEvent.unserialize(cp, csprintf("%s.tickEvent", section));
 }
@@ -194,23 +200,23 @@ AtomicSimpleCPU::unserialize(Checkpoint *cp, const string &section)
 void
 AtomicSimpleCPU::resume()
 {
+    if (_status == Idle || _status == SwitchedOut)
+        return;
+
     DPRINTF(SimpleCPU, "Resume\n");
-    if (_status != SwitchedOut && _status != Idle) {
-        assert(system->getMemoryMode() == Enums::atomic);
+    assert(system->getMemoryMode() == Enums::atomic);
 
-        changeState(SimObject::Running);
-        if (thread->status() == ThreadContext::Active) {
-            if (!tickEvent.scheduled()) {
-                tickEvent.schedule(nextCycle());
-            }
-        }
+    changeState(SimObject::Running);
+    if (thread->status() == ThreadContext::Active) {
+        if (!tickEvent.scheduled())
+            schedule(tickEvent, nextCycle());
     }
 }
 
 void
 AtomicSimpleCPU::switchOut()
 {
-    assert(status() == Running || status() == Idle);
+    assert(_status == Running || _status == Idle);
     _status = SwitchedOut;
 
     tickEvent.squash();
@@ -226,11 +232,12 @@ AtomicSimpleCPU::takeOverFrom(BaseCPU *oldCPU)
 
     // if any of this CPU's ThreadContexts are active, mark the CPU as
     // running and schedule its tick event.
-    for (int i = 0; i < threadContexts.size(); ++i) {
+    ThreadID size = threadContexts.size();
+    for (ThreadID i = 0; i < size; ++i) {
         ThreadContext *tc = threadContexts[i];
         if (tc->status() == ThreadContext::Active && _status != Running) {
             _status = Running;
-            tickEvent.schedule(nextCycle());
+            schedule(tickEvent, nextCycle());
             break;
         }
     }
@@ -238,7 +245,9 @@ AtomicSimpleCPU::takeOverFrom(BaseCPU *oldCPU)
         _status = Idle;
     }
     assert(threadContexts.size() == 1);
-    cpuId = tc->readCpuId();
+    ifetch_req.setThreadContext(_cpuId, 0); // Add thread ID if we add MT
+    data_read_req.setThreadContext(_cpuId, 0); // Add thread ID here too
+    data_write_req.setThreadContext(_cpuId, 0); // Add thread ID here too
 }
 
 
@@ -257,7 +266,7 @@ AtomicSimpleCPU::activateContext(int thread_num, int delay)
     numCycles += tickToCycles(thread->lastActivate - thread->lastSuspend);
 
     //Make sure ticks are still on multiples of cycles
-    tickEvent.schedule(nextCycle(curTick + ticks(delay)));
+    schedule(tickEvent, nextCycle(curTick + ticks(delay)));
     _status = Running;
 }
 
@@ -270,12 +279,15 @@ AtomicSimpleCPU::suspendContext(int thread_num)
     assert(thread_num == 0);
     assert(thread);
 
+    if (_status == Idle)
+        return;
+
     assert(_status == Running);
 
     // tick event may not be scheduled if this gets called from inside
     // an instruction's execution, e.g. "quiesce"
     if (tickEvent.scheduled())
-        tickEvent.deschedule();
+        deschedule(tickEvent);
 
     notIdleFraction--;
     _status = Idle;
@@ -294,7 +306,7 @@ AtomicSimpleCPU::read(Addr addr, T &data, unsigned flags)
     }
 
     //The block size of our peer.
-    int blockSize = dcachePort.peerBlockSize();
+    unsigned blockSize = dcachePort.peerBlockSize();
     //The size of the data we're trying to read.
     int dataSize = sizeof(T);
 
@@ -313,12 +325,12 @@ AtomicSimpleCPU::read(Addr addr, T &data, unsigned flags)
         req->setVirt(0, addr, dataSize, flags, thread->readPC());
 
         // translate to physical address
-        Fault fault = thread->translateDataReadReq(req);
+        Fault fault = thread->dtb->translateAtomic(req, tc, BaseTLB::Read);
 
         // Now do the access.
-        if (fault == NoFault) {
+        if (fault == NoFault && !req->getFlags().isSet(Request::NO_ACCESS)) {
             Packet pkt = Packet(req,
-                    req->isLocked() ? MemCmd::LoadLockedReq : MemCmd::ReadReq,
+                    req->isLLSC() ? MemCmd::LoadLockedReq : MemCmd::ReadReq,
                     Packet::Broadcast);
             pkt.dataStatic(dataPtr);
 
@@ -334,7 +346,7 @@ AtomicSimpleCPU::read(Addr addr, T &data, unsigned flags)
 
             assert(!pkt.isError());
 
-            if (req->isLocked()) {
+            if (req->isLLSC()) {
                 TheISA::handleLockedRead(thread, req);
             }
         }
@@ -344,12 +356,25 @@ AtomicSimpleCPU::read(Addr addr, T &data, unsigned flags)
             recordEvent("Uncached Read");
 
         //If there's a fault, return it
-        if (fault != NoFault)
-            return fault;
+        if (fault != NoFault) {
+            if (req->isPrefetch()) {
+                return NoFault;
+            } else {
+                return fault;
+            }
+        }
+
         //If we don't need to access a second cache line, stop now.
         if (secondAddr <= addr)
         {
             data = gtoh(data);
+            if (traceData) {
+                traceData->setData(data);
+            }
+            if (req->isLocked() && fault == NoFault) {
+                assert(!locked);
+                locked = true;
+            }
             return fault;
         }
 
@@ -429,7 +454,7 @@ AtomicSimpleCPU::write(T data, Addr addr, unsigned flags, uint64_t *res)
     }
 
     //The block size of our peer.
-    int blockSize = dcachePort.peerBlockSize();
+    unsigned blockSize = dcachePort.peerBlockSize();
     //The size of the data we're trying to read.
     int dataSize = sizeof(T);
 
@@ -448,14 +473,14 @@ AtomicSimpleCPU::write(T data, Addr addr, unsigned flags, uint64_t *res)
         req->setVirt(0, addr, dataSize, flags, thread->readPC());
 
         // translate to physical address
-        Fault fault = thread->translateDataWriteReq(req);
+        Fault fault = thread->dtb->translateAtomic(req, tc, BaseTLB::Write);
 
         // Now do the access.
         if (fault == NoFault) {
             MemCmd cmd = MemCmd::WriteReq; // default
             bool do_access = true;  // flag to suppress cache access
 
-            if (req->isLocked()) {
+            if (req->isLLSC()) {
                 cmd = MemCmd::StoreCondReq;
                 do_access = TheISA::handleLockedWrite(thread, req);
             } else if (req->isSwap()) {
@@ -466,7 +491,7 @@ AtomicSimpleCPU::write(T data, Addr addr, unsigned flags, uint64_t *res)
                 }
             }
 
-            if (do_access) {
+            if (do_access && !req->getFlags().isSet(Request::NO_ACCESS)) {
                 Packet pkt = Packet(req, cmd, Packet::Broadcast);
                 pkt.dataStatic(dataPtr);
 
@@ -508,7 +533,18 @@ AtomicSimpleCPU::write(T data, Addr addr, unsigned flags, uint64_t *res)
             // If the write needs to have a fault on the access, consider
             // calling changeStatus() and changing it to "bad addr write"
             // or something.
-            return fault;
+            if (traceData) {
+                traceData->setData(gtoh(data));
+            }
+            if (req->isLocked() && fault == NoFault) {
+                assert(locked);
+                locked = false;
+            }
+            if (fault != NoFault && req->isPrefetch()) {
+                return NoFault;
+            } else {
+                return fault;
+            }
         }
 
         /*
@@ -587,39 +623,54 @@ AtomicSimpleCPU::tick()
 {
     DPRINTF(SimpleCPU, "Tick\n");
 
-    Tick latency = ticks(1); // instruction takes one cycle by default
+    Tick latency = 0;
 
-    for (int i = 0; i < width; ++i) {
+    for (int i = 0; i < width || locked; ++i) {
         numCycles++;
 
         if (!curStaticInst || !curStaticInst->isDelayedCommit())
             checkForInterrupts();
 
-        Fault fault = setupFetchRequest(&ifetch_req);
+        checkPcEventQueue();
+
+        Fault fault = NoFault;
+
+        bool fromRom = isRomMicroPC(thread->readMicroPC());
+        if (!fromRom && !curMacroStaticInst) {
+            setupFetchRequest(&ifetch_req);
+            fault = thread->itb->translateAtomic(&ifetch_req, tc,
+                                                 BaseTLB::Execute);
+        }
 
         if (fault == NoFault) {
             Tick icache_latency = 0;
             bool icache_access = false;
             dcache_access = false; // assume no dcache access
 
-            //Fetch more instruction memory if necessary
-            //if(predecoder.needMoreBytes())
-            //{
-                icache_access = true;
-                Packet ifetch_pkt = Packet(&ifetch_req, MemCmd::ReadReq,
-                                           Packet::Broadcast);
-                ifetch_pkt.dataStatic(&inst);
-
-                if (hasPhysMemPort && ifetch_pkt.getAddr() == physMemAddr)
-                    icache_latency = physmemPort.sendAtomic(&ifetch_pkt);
-                else
-                    icache_latency = icachePort.sendAtomic(&ifetch_pkt);
+            if (!fromRom && !curMacroStaticInst) {
+                // This is commented out because the predecoder would act like
+                // a tiny cache otherwise. It wouldn't be flushed when needed
+                // like the I cache. It should be flushed, and when that works
+                // this code should be uncommented.
+                //Fetch more instruction memory if necessary
+                //if(predecoder.needMoreBytes())
+                //{
+                    icache_access = true;
+                    Packet ifetch_pkt = Packet(&ifetch_req, MemCmd::ReadReq,
+                                               Packet::Broadcast);
+                    ifetch_pkt.dataStatic(&inst);
+
+                    if (hasPhysMemPort && ifetch_pkt.getAddr() == physMemAddr)
+                        icache_latency = physmemPort.sendAtomic(&ifetch_pkt);
+                    else
+                        icache_latency = icachePort.sendAtomic(&ifetch_pkt);
 
-                assert(!ifetch_pkt.isError());
+                    assert(!ifetch_pkt.isError());
 
-                // ifetch_req is initialized to read the instruction directly
-                // into the CPU object's inst field.
-            //}
+                    // ifetch_req is initialized to read the instruction directly
+                    // into the CPU object's inst field.
+                //}
+            }
 
             preExecute();
 
@@ -643,16 +694,21 @@ AtomicSimpleCPU::tick()
                         curStaticInst->isFirstMicroop()))
                 instCnt++;
 
-            if (simulate_stalls) {
-                Tick icache_stall =
-                    icache_access ? icache_latency - ticks(1) : 0;
-                Tick dcache_stall =
-                    dcache_access ? dcache_latency - ticks(1) : 0;
-                Tick stall_cycles = (icache_stall + dcache_stall) / ticks(1);
-                if (ticks(stall_cycles) < (icache_stall + dcache_stall))
-                    latency += ticks(stall_cycles+1);
-                else
-                    latency += ticks(stall_cycles);
+            Tick stall_ticks = 0;
+            if (simulate_inst_stalls && icache_access)
+                stall_ticks += icache_latency;
+
+            if (simulate_data_stalls && dcache_access)
+                stall_ticks += dcache_latency;
+
+            if (stall_ticks) {
+                Tick stall_cycles = stall_ticks / ticks(1);
+                Tick aligned_stall_ticks = ticks(stall_cycles);
+
+                if (aligned_stall_ticks < stall_ticks)
+                    aligned_stall_ticks += 1;
+
+                latency += aligned_stall_ticks;
             }
 
         }
@@ -660,8 +716,19 @@ AtomicSimpleCPU::tick()
             advancePC(fault);
     }
 
+    // instruction takes at least one cycle
+    if (latency < ticks(1))
+        latency = ticks(1);
+
     if (_status != Idle)
-        tickEvent.schedule(curTick + latency);
+        schedule(tickEvent, curTick + latency);
+}
+
+
+void
+AtomicSimpleCPU::printAddr(Addr a)
+{
+    dcachePort.printAddr(a);
 }
 
 
@@ -672,38 +739,10 @@ AtomicSimpleCPU::tick()
 AtomicSimpleCPU *
 AtomicSimpleCPUParams::create()
 {
-    AtomicSimpleCPU::Params *params = new AtomicSimpleCPU::Params();
-    params->name = name;
-    params->numberOfThreads = 1;
-    params->max_insts_any_thread = max_insts_any_thread;
-    params->max_insts_all_threads = max_insts_all_threads;
-    params->max_loads_any_thread = max_loads_any_thread;
-    params->max_loads_all_threads = max_loads_all_threads;
-    params->progress_interval = progress_interval;
-    params->deferRegistration = defer_registration;
-    params->phase = phase;
-    params->clock = clock;
-    params->functionTrace = function_trace;
-    params->functionTraceStart = function_trace_start;
-    params->width = width;
-    params->simulate_stalls = simulate_stalls;
-    params->system = system;
-    params->cpu_id = cpu_id;
-    params->tracer = tracer;
-
-    params->itb = itb;
-    params->dtb = dtb;
-#if FULL_SYSTEM
-    params->profile = profile;
-    params->do_quiesce = do_quiesce;
-    params->do_checkpoint_insts = do_checkpoint_insts;
-    params->do_statistics_insts = do_statistics_insts;
-#else
+    numThreads = 1;
+#if !FULL_SYSTEM
     if (workload.size() != 1)
         panic("only one workload allowed");
-    params->process = workload[0];
 #endif
-
-    AtomicSimpleCPU *cpu = new AtomicSimpleCPU(params);
-    return cpu;
+    return new AtomicSimpleCPU(this);
 }