gem5/src/cpu/base.hh
Andreas Sandberg 1eec115c31 cpu: Refactor memory system checks
CPUs need to test that the memory system is in the right mode in two
places, when the CPU is initialized (unless it's switched out) and on
a drainResume(). This led to some code duplication in the CPU
models. This changeset introduces the verifyMemoryMode() method which
is called by BaseCPU::init() if the CPU isn't switched out. The
individual CPU models are responsible for calling this method when
resuming from a drain as this code is CPU model specific.
2013-02-15 17:40:08 -05:00

480 lines
14 KiB
C++

/*
* Copyright (c) 2011-2012 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
* Copyright (c) 2011 Regents of the University of California
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Steve Reinhardt
* Nathan Binkert
* Rick Strong
*/
#ifndef __CPU_BASE_HH__
#define __CPU_BASE_HH__
#include <vector>
#include "arch/interrupts.hh"
#include "arch/isa_traits.hh"
#include "arch/microcode_rom.hh"
#include "base/statistics.hh"
#include "config/the_isa.hh"
#include "mem/mem_object.hh"
#include "sim/eventq.hh"
#include "sim/full_system.hh"
#include "sim/insttracer.hh"
struct BaseCPUParams;
class BranchPred;
class CheckerCPU;
class ThreadContext;
class System;
class CPUProgressEvent : public Event
{
protected:
Tick _interval;
Counter lastNumInst;
BaseCPU *cpu;
bool _repeatEvent;
public:
CPUProgressEvent(BaseCPU *_cpu, Tick ival = 0);
void process();
void interval(Tick ival) { _interval = ival; }
Tick interval() { return _interval; }
void repeatEvent(bool repeat) { _repeatEvent = repeat; }
virtual const char *description() const;
};
class BaseCPU : public MemObject
{
protected:
// @todo remove me after debugging with legion done
Tick instCnt;
// every cpu has an id, put it in the base cpu
// Set at initialization, only time a cpuId might change is during a
// takeover (which should be done from within the BaseCPU anyway,
// therefore no setCpuId() method is provided
int _cpuId;
/** instruction side request id that must be placed in all requests */
MasterID _instMasterId;
/** data side request id that must be placed in all requests */
MasterID _dataMasterId;
/** An intrenal representation of a task identifier within gem5. This is
* used so the CPU can add which taskId (which is an internal representation
* of the OS process ID) to each request so components in the memory system
* can track which process IDs are ultimately interacting with them
*/
uint32_t _taskId;
/** The current OS process ID that is executing on this processor. This is
* used to generate a taskId */
uint32_t _pid;
/** Is the CPU switched out or active? */
bool _switchedOut;
/**
* Define a base class for the CPU ports (instruction and data)
* that is refined in the subclasses. This class handles the
* common cases, i.e. the functional accesses and the status
* changes and address range queries. The default behaviour for
* both atomic and timing access is to panic and the corresponding
* subclasses have to override these methods.
*/
class CpuPort : public MasterPort
{
public:
/**
* Create a CPU port with a name and a structural owner.
*
* @param _name port name including the owner
* @param _name structural owner of this port
*/
CpuPort(const std::string& _name, MemObject* _owner) :
MasterPort(_name, _owner)
{ }
protected:
virtual bool recvTimingResp(PacketPtr pkt);
virtual void recvRetry();
virtual void recvFunctionalSnoop(PacketPtr pkt);
};
public:
/**
* Purely virtual method that returns a reference to the data
* port. All subclasses must implement this method.
*
* @return a reference to the data port
*/
virtual CpuPort &getDataPort() = 0;
/**
* Purely virtual method that returns a reference to the instruction
* port. All subclasses must implement this method.
*
* @return a reference to the instruction port
*/
virtual CpuPort &getInstPort() = 0;
/** Reads this CPU's ID. */
int cpuId() { return _cpuId; }
/** Reads this CPU's unique data requestor ID */
MasterID dataMasterId() { return _dataMasterId; }
/** Reads this CPU's unique instruction requestor ID */
MasterID instMasterId() { return _instMasterId; }
/**
* Get a master port on this CPU. All CPUs have a data and
* instruction port, and this method uses getDataPort and
* getInstPort of the subclasses 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
*/
BaseMasterPort &getMasterPort(const std::string &if_name,
PortID idx = InvalidPortID);
/** Get cpu task id */
uint32_t taskId() const { return _taskId; }
/** Set cpu task id */
void taskId(uint32_t id) { _taskId = id; }
uint32_t getPid() const { return _pid; }
void setPid(uint32_t pid) { _pid = pid; }
inline void workItemBegin() { numWorkItemsStarted++; }
inline void workItemEnd() { numWorkItemsCompleted++; }
// @todo remove me after debugging with legion done
Tick instCount() { return instCnt; }
TheISA::MicrocodeRom microcodeRom;
protected:
TheISA::Interrupts *interrupts;
public:
TheISA::Interrupts *
getInterruptController()
{
return interrupts;
}
virtual void wakeup() = 0;
void
postInterrupt(int int_num, int index)
{
interrupts->post(int_num, index);
if (FullSystem)
wakeup();
}
void
clearInterrupt(int int_num, int index)
{
interrupts->clear(int_num, index);
}
void
clearInterrupts()
{
interrupts->clearAll();
}
bool
checkInterrupts(ThreadContext *tc) const
{
return FullSystem && interrupts->checkInterrupts(tc);
}
class ProfileEvent : public Event
{
private:
BaseCPU *cpu;
Tick interval;
public:
ProfileEvent(BaseCPU *cpu, Tick interval);
void process();
};
ProfileEvent *profileEvent;
protected:
std::vector<ThreadContext *> threadContexts;
Trace::InstTracer * tracer;
public:
// Mask to align PCs to MachInst sized boundaries
static const Addr PCMask = ~((Addr)sizeof(TheISA::MachInst) - 1);
/// Provide access to the tracer pointer
Trace::InstTracer * getTracer() { return tracer; }
/// Notify the CPU that the indicated context is now active. The
/// delay parameter indicates the number of ticks to wait before
/// executing (typically 0 or 1).
virtual void activateContext(ThreadID thread_num, Cycles delay) {}
/// Notify the CPU that the indicated context is now suspended.
virtual void suspendContext(ThreadID thread_num) {}
/// Notify the CPU that the indicated context is now deallocated.
virtual void deallocateContext(ThreadID thread_num) {}
/// Notify the CPU that the indicated context is now halted.
virtual void haltContext(ThreadID thread_num) {}
/// Given a Thread Context pointer return the thread num
int findContext(ThreadContext *tc);
/// Given a thread num get tho thread context for it
ThreadContext *getContext(int tn) { return threadContexts[tn]; }
public:
typedef BaseCPUParams Params;
const Params *params() const
{ return reinterpret_cast<const Params *>(_params); }
BaseCPU(Params *params, bool is_checker = false);
virtual ~BaseCPU();
virtual void init();
virtual void startup();
virtual void regStats();
virtual void activateWhenReady(ThreadID tid) {};
void registerThreadContexts();
/**
* Prepare for another CPU to take over execution.
*
* When this method exits, all internal state should have been
* flushed. After the method returns, the simulator calls
* takeOverFrom() on the new CPU with this CPU as its parameter.
*/
virtual void switchOut();
/**
* Load the state of a CPU from the previous CPU object, invoked
* on all new CPUs that are about to be switched in.
*
* A CPU model implementing this method is expected to initialize
* its state from the old CPU and connect its memory (unless they
* are already connected) to the memories connected to the old
* CPU.
*
* @param cpu CPU to initialize read state from.
*/
virtual void takeOverFrom(BaseCPU *cpu);
/**
* Flush all TLBs in the CPU.
*
* This method is mainly used to flush stale translations when
* switching CPUs. It is also exported to the Python world to
* allow it to request a TLB flush after draining the CPU to make
* it easier to compare traces when debugging
* handover/checkpointing.
*/
void flushTLBs();
/**
* Determine if the CPU is switched out.
*
* @return True if the CPU is switched out, false otherwise.
*/
bool switchedOut() const { return _switchedOut; }
/**
* Verify that the system is in a memory mode supported by the
* CPU.
*
* Implementations are expected to query the system for the
* current memory mode and ensure that it is what the CPU model
* expects. If the check fails, the implementation should
* terminate the simulation using fatal().
*/
virtual void verifyMemoryMode() const { };
/**
* Number of threads we're actually simulating (<= SMT_MAX_THREADS).
* This is a constant for the duration of the simulation.
*/
ThreadID numThreads;
/**
* Vector of per-thread instruction-based event queues. Used for
* scheduling events based on number of instructions committed by
* a particular thread.
*/
EventQueue **comInstEventQueue;
/**
* Vector of per-thread load-based event queues. Used for
* scheduling events based on number of loads committed by
*a particular thread.
*/
EventQueue **comLoadEventQueue;
System *system;
/**
* Serialize this object to the given output stream.
*
* @note CPU models should normally overload the serializeThread()
* method instead of the serialize() method as this provides a
* uniform data format for all CPU models and promotes better code
* reuse.
*
* @param os The stream to serialize to.
*/
virtual void serialize(std::ostream &os);
/**
* Reconstruct the state of this object from a checkpoint.
*
* @note CPU models should normally overload the
* unserializeThread() method instead of the unserialize() method
* as this provides a uniform data format for all CPU models and
* promotes better code reuse.
* @param cp The checkpoint use.
* @param section The section name of this object.
*/
virtual void unserialize(Checkpoint *cp, const std::string &section);
/**
* Serialize a single thread.
*
* @param os The stream to serialize to.
* @param tid ID of the current thread.
*/
virtual void serializeThread(std::ostream &os, ThreadID tid) {};
/**
* Unserialize one thread.
*
* @param cp The checkpoint use.
* @param section The section name of this thread.
* @param tid ID of the current thread.
*/
virtual void unserializeThread(Checkpoint *cp, const std::string &section,
ThreadID tid) {};
/**
* Return pointer to CPU's branch predictor (NULL if none).
* @return Branch predictor pointer.
*/
virtual BranchPred *getBranchPred() { return NULL; };
virtual Counter totalInsts() const = 0;
virtual Counter totalOps() const = 0;
// Function tracing
private:
bool functionTracingEnabled;
std::ostream *functionTraceStream;
Addr currentFunctionStart;
Addr currentFunctionEnd;
Tick functionEntryTick;
void enableFunctionTrace();
void traceFunctionsInternal(Addr pc);
private:
static std::vector<BaseCPU *> cpuList; //!< Static global cpu list
public:
void traceFunctions(Addr pc)
{
if (functionTracingEnabled)
traceFunctionsInternal(pc);
}
static int numSimulatedCPUs() { return cpuList.size(); }
static Counter numSimulatedInsts()
{
Counter total = 0;
int size = cpuList.size();
for (int i = 0; i < size; ++i)
total += cpuList[i]->totalInsts();
return total;
}
static Counter numSimulatedOps()
{
Counter total = 0;
int size = cpuList.size();
for (int i = 0; i < size; ++i)
total += cpuList[i]->totalOps();
return total;
}
public:
// Number of CPU cycles simulated
Stats::Scalar numCycles;
Stats::Scalar numWorkItemsStarted;
Stats::Scalar numWorkItemsCompleted;
};
#endif // __CPU_BASE_HH__