Atomic: Remove the physmem_port and access memory directly

This patch removes the physmem_port from the Atomic CPU and instead
uses the system pointer to access the physmem when using the fastmem
option. The system already keeps track of the physmem and the valid
memory address ranges, and with this patch we merely make use of that
existing functionality. As a result of this change, the overloaded
getMasterPort in the Atomic CPU can be removed, thus unifying the CPUs.

configs/example/fs.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2010-2011 ARM Limited
+# Copyright (c) 2010-2012 ARM Limited
 # All rights reserved.
 #
 # The license below extends only to copyright in the software and shall
@@ -133,9 +133,13 @@ else:
     test_sys.iobridge.slave = test_sys.iobus.master
     test_sys.iobridge.master = test_sys.membus.slave
 
+# Sanity check
+if options.fastmem and (options.caches or options.l2cache):
+    fatal("You cannot use fastmem in combination with caches!")
+
 for i in xrange(np):
     if options.fastmem:
-        test_sys.cpu[i].physmem_port = test_sys.physmem.port
+        test_sys.cpu[i].fastmem = True
     if options.checker:
         test_sys.cpu[i].addCheckerCpu()
 
@@ -160,7 +164,7 @@ if len(bm) == 2:
     drive_sys.cpu.createInterruptController()
     drive_sys.cpu.connectAllPorts(drive_sys.membus)
     if options.fastmem:
-        drive_sys.cpu.physmem_port = drive_sys.physmem.port
+        drive_sys.cpu.fastmem = True
     if options.kernel is not None:
         drive_sys.kernel = binary(options.kernel)
     drive_sys.iobridge = Bridge(delay='50ns', nack_delay='4ns',

configs/example/se.py

@@ -155,11 +155,15 @@ system = System(cpu = [CPUClass(cpu_id=i) for i in xrange(np)],
                 physmem = PhysicalMemory(range=AddrRange("512MB")),
                 membus = Bus(), mem_mode = test_mem_mode)
 
+# Sanity check
+if options.fastmem and (options.caches or options.l2cache):
+    fatal("You cannot use fastmem in combination with caches!")
+
 for i in xrange(np):
     system.cpu[i].workload = multiprocesses[i]
 
     if options.fastmem:
-        system.cpu[0].physmem_port = system.physmem.port
+        system.cpu[0].fastmem = True
 
     if options.checker:
         system.cpu[i].addCheckerCpu()

src/cpu/base.hh

@@ -170,22 +170,16 @@ class BaseCPU : public MemObject
     MasterID instMasterId() { return _instMasterId; }
 
     /**
-     * Get a master port on this MemObject. This method is virtual to allow
+     * Get a master port on this CPU. All CPUs have a data and
-     * the subclasses of the BaseCPU to override it. All CPUs have a
+     * instruction port, and this method uses getDataPort and
-     * data and instruction port, but the Atomic CPU (in its current
+     * getInstPort of the subclasses to resolve the two ports.
-     * form) adds a port directly connected to the memory and has to
-     * override getMasterPort.
-     *
-     * This method uses getDataPort and getInstPort to resolve the two
-     * ports.
      *
      * @param if_name the port name
      * @param idx ignored index
      *
      * @return a reference to the port with the given name
      */
-    virtual MasterPort &getMasterPort(const std::string &if_name,
+    MasterPort &getMasterPort(const std::string &if_name, int idx = -1);
-                                      int idx = -1);
 
 //    Tick currentTick;
     inline Tick frequency() const { return SimClock::Frequency / clock; }

src/cpu/simple/AtomicSimpleCPU.py

@@ -1,3 +1,15 @@
+# Copyright (c) 2012 ARM Limited
+# All rights reserved.
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
 # Copyright (c) 2007 The Regents of The University of Michigan
 # All rights reserved.
 #
@@ -34,4 +46,4 @@ class AtomicSimpleCPU(BaseSimpleCPU):
     width = Param.Int(1, "CPU width")
     simulate_data_stalls = Param.Bool(False, "Simulate dcache stall cycles")
     simulate_inst_stalls = Param.Bool(False, "Simulate icache stall cycles")
-    physmem_port = MasterPort("Physical Memory Port")
+    fastmem = Param.Bool(False, "Access memory directly")

src/cpu/simple/atomic.cc

@@ -1,4 +1,16 @@
 /*
+ * Copyright (c) 2012 ARM Limited
+ * All rights reserved.
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
  * Copyright (c) 2002-2005 The Regents of The University of Michigan
  * All rights reserved.
  *
@@ -39,6 +51,7 @@
 #include "debug/SimpleCPU.hh"
 #include "mem/packet.hh"
 #include "mem/packet_access.hh"
+#include "mem/physical.hh"
 #include "params/AtomicSimpleCPU.hh"
 #include "sim/faults.hh"
 #include "sim/system.hh"
@@ -65,17 +78,6 @@ AtomicSimpleCPU::TickEvent::description() const
     return "AtomicSimpleCPU tick";
 }
 
-MasterPort &
-AtomicSimpleCPU::getMasterPort(const string &if_name, int idx)
-{
-    if (if_name == "physmem_port") {
-        hasPhysMemPort = true;
-        return physmemPort;
-    } else {
-        return BaseCPU::getMasterPort(if_name, idx);
-    }
-}
-
 void
 AtomicSimpleCPU::init()
 {
@@ -93,8 +95,8 @@ AtomicSimpleCPU::init()
         }
     }
 
-    if (hasPhysMemPort) {
+    if (fastmem) {
-        AddrRangeList pmAddrList = physmemPort.getSlavePort().getAddrRanges();
+        AddrRangeList pmAddrList = system->physmem->getAddrRanges();
         physMemAddr = *pmAddrList.begin();
     }
     // Atomic doesn't do MT right now, so contextId == threadId
@@ -108,7 +110,7 @@ AtomicSimpleCPU::AtomicSimpleCPU(AtomicSimpleCPUParams *p)
       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)
+      fastmem(p->fastmem)
 {
     _status = Idle;
 }
@@ -281,8 +283,8 @@ AtomicSimpleCPU::readMem(Addr addr, uint8_t * data,
             if (req->isMmappedIpr())
                 dcache_latency += TheISA::handleIprRead(thread->getTC(), &pkt);
             else {
-                if (hasPhysMemPort && pkt.getAddr() == physMemAddr)
+                if (fastmem && pkt.getAddr() == physMemAddr)
-                    dcache_latency += physmemPort.sendAtomic(&pkt);
+                    dcache_latency += system->physmem->doAtomicAccess(&pkt);
                 else
                     dcache_latency += dcachePort.sendAtomic(&pkt);
             }
@@ -383,8 +385,8 @@ AtomicSimpleCPU::writeMem(uint8_t *data, unsigned size,
                     dcache_latency +=
                         TheISA::handleIprWrite(thread->getTC(), &pkt);
                 } else {
-                    if (hasPhysMemPort && pkt.getAddr() == physMemAddr)
+                    if (fastmem && pkt.getAddr() == physMemAddr)
-                        dcache_latency += physmemPort.sendAtomic(&pkt);
+                        dcache_latency += system->physmem->doAtomicAccess(&pkt);
                     else
                         dcache_latency += dcachePort.sendAtomic(&pkt);
                 }
@@ -479,8 +481,9 @@ AtomicSimpleCPU::tick()
                                                Packet::Broadcast);
                     ifetch_pkt.dataStatic(&inst);
 
-                    if (hasPhysMemPort && ifetch_pkt.getAddr() == physMemAddr)
+                    if (fastmem && ifetch_pkt.getAddr() == physMemAddr)
-                        icache_latency = physmemPort.sendAtomic(&ifetch_pkt);
+                        icache_latency =
+                            system->physmem->doAtomicAccess(&ifetch_pkt);
                     else
                         icache_latency = icachePort.sendAtomic(&ifetch_pkt);
 

src/cpu/simple/atomic.hh

@@ -1,4 +1,16 @@
 /*
+ * Copyright (c) 2012 ARM Limited
+ * All rights reserved.
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
  * Copyright (c) 2002-2005 The Regents of The University of Michigan
  * All rights reserved.
  *
@@ -90,8 +102,7 @@ class AtomicSimpleCPU : public BaseSimpleCPU
     AtomicCPUPort icachePort;
     AtomicCPUPort dcachePort;
 
-    CpuPort physmemPort;
+    bool fastmem;
-    bool hasPhysMemPort;
     Request ifetch_req;
     Request data_read_req;
     Request data_write_req;
@@ -111,13 +122,6 @@ class AtomicSimpleCPU : public BaseSimpleCPU
 
   public:
 
-    /**
-     * Override the getMasterPort of the BaseCPU so that we can
-     * provide the physmemPort, unique to the Atomic CPU.
-     */
-    virtual MasterPort &getMasterPort(const std::string &if_name,
-                                      int idx = -1);
-
     virtual void serialize(std::ostream &os);
     virtual void unserialize(Checkpoint *cp, const std::string &section);
     virtual void resume();