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/*
* Copyright (c) 2011-2012, 2016-2018, 2020 ARM Limited
* Copyright (c) 2013 Advanced Micro Devices, Inc.
* 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) 2006 The Regents of The University of Michigan
* 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.
*/
#ifndef __CPU_THREAD_CONTEXT_HH__
#define __CPU_THREAD_CONTEXT_HH__
#include <iostream>
#include <string>
#include "arch/generic/htm.hh"
#include "arch/generic/isa.hh"
#include "arch/generic/pcstate.hh"
#include "base/types.hh"
#include "cpu/pc_event.hh"
#include "cpu/reg_class.hh"
namespace gem5
{
// @todo: Figure out a more architecture independent way to obtain the ITB and
// DTB pointers.
class BaseCPU;
class BaseMMU;
class BaseTLB;
class CheckerCPU;
class Checkpoint;
class InstDecoder;
class PortProxy;
class Process;
class System;
class Packet;
using PacketPtr = Packet *;
/**
* ThreadContext is the external interface to all thread state for
* anything outside of the CPU. It provides all accessor methods to
* state that might be needed by external objects, ranging from
* register values to things such as kernel stats. It is an abstract
* base class; the CPU can create its own ThreadContext by
* deriving from it.
*
* The ThreadContext is slightly different than the ExecContext. The
* ThreadContext provides access to an individual thread's state; an
* ExecContext provides ISA access to the CPU (meaning it is
* implicitly multithreaded on SMT systems). Additionally the
* ThreadState is an abstract class that exactly defines the
* interface; the ExecContext is a more implicit interface that must
* be implemented so that the ISA can access whatever state it needs.
*/
class ThreadContext : public PCEventScope
{
protected:
bool useForClone = false;
public:
bool getUseForClone() { return useForClone; }
void setUseForClone(bool new_val) { useForClone = new_val; }
enum Status
{
/// Running. Instructions should be executed only when
/// the context is in this state.
Active,
/// Temporarily inactive. Entered while waiting for
/// synchronization, etc.
Suspended,
/// Trying to exit and waiting for an event to completely exit.
/// Entered when target executes an exit syscall.
Halting,
/// Permanently shut down. Entered when target executes
/// m5exit pseudo-instruction. When all contexts enter
/// this state, the simulation will terminate.
Halted
};
virtual ~ThreadContext() { };
virtual BaseCPU *getCpuPtr() = 0;
virtual int cpuId() const = 0;
virtual uint32_t socketId() const = 0;
virtual int threadId() const = 0;
virtual void setThreadId(int id) = 0;
virtual ContextID contextId() const = 0;
virtual void setContextId(ContextID id) = 0;
virtual BaseMMU *getMMUPtr() = 0;
virtual CheckerCPU *getCheckerCpuPtr() = 0;
virtual BaseISA *getIsaPtr() const = 0;
virtual InstDecoder *getDecoderPtr() = 0;
virtual System *getSystemPtr() = 0;
virtual void sendFunctional(PacketPtr pkt);
virtual Process *getProcessPtr() = 0;
virtual void setProcessPtr(Process *p) = 0;
virtual Status status() const = 0;
virtual void setStatus(Status new_status) = 0;
/// Set the status to Active.
virtual void activate() = 0;
/// Set the status to Suspended.
virtual void suspend() = 0;
/// Set the status to Halted.
virtual void halt() = 0;
/// Quiesce thread context
void quiesce();
/// Quiesce, suspend, and schedule activate at resume
void quiesceTick(Tick resume);
virtual void takeOverFrom(ThreadContext *old_context) = 0;
virtual void regStats(const std::string &name) {};
virtual void scheduleInstCountEvent(Event *event, Tick count) = 0;
virtual void descheduleInstCountEvent(Event *event) = 0;
virtual Tick getCurrentInstCount() = 0;
// Not necessarily the best location for these...
// Having an extra function just to read these is obnoxious
virtual Tick readLastActivate() = 0;
virtual Tick readLastSuspend() = 0;
virtual void copyArchRegs(ThreadContext *tc) = 0;
virtual void clearArchRegs() = 0;
//
// New accessors for new decoder.
//
virtual RegVal getReg(const RegId &reg) const;
virtual void getReg(const RegId &reg, void *val) const = 0;
virtual void *getWritableReg(const RegId &reg) = 0;
virtual void setReg(const RegId &reg, RegVal val);
virtual void setReg(const RegId &reg, const void *val) = 0;
virtual const PCStateBase &pcState() const = 0;
virtual void pcState(const PCStateBase &val) = 0;
void
pcState(Addr addr)
{
std::unique_ptr<PCStateBase> new_pc(getIsaPtr()->newPCState(addr));
pcState(*new_pc);
}
virtual void pcStateNoRecord(const PCStateBase &val) = 0;
virtual RegVal readMiscRegNoEffect(RegIndex misc_reg) const = 0;
virtual RegVal readMiscReg(RegIndex misc_reg) = 0;
virtual void setMiscRegNoEffect(RegIndex misc_reg, RegVal val) = 0;
virtual void setMiscReg(RegIndex misc_reg, RegVal val) = 0;
// Also not necessarily the best location for these two. Hopefully will go
// away once we decide upon where st cond failures goes.
virtual unsigned readStCondFailures() const = 0;
virtual void setStCondFailures(unsigned sc_failures) = 0;
// This function exits the thread context in the CPU and returns
// 1 if the CPU has no more active threads (meaning it's OK to exit);
// Used in syscall-emulation mode when a thread calls the exit syscall.
virtual int exit() { return 1; };
/** function to compare two thread contexts (for debugging) */
static void compare(ThreadContext *one, ThreadContext *two);
// hardware transactional memory
virtual void htmAbortTransaction(uint64_t htm_uid,
HtmFailureFaultCause cause) = 0;
virtual BaseHTMCheckpointPtr& getHtmCheckpointPtr() = 0;
virtual void setHtmCheckpointPtr(BaseHTMCheckpointPtr cpt) = 0;
};
/** @{ */
/**
* Thread context serialization helpers
*
* These helper functions provide a way to the data in a
* ThreadContext. They are provided as separate helper function since
* implementing them as members of the ThreadContext interface would
* be confusing when the ThreadContext is exported via a proxy.
*/
void serialize(const ThreadContext &tc, CheckpointOut &cp);
void unserialize(ThreadContext &tc, CheckpointIn &cp);
/** @} */
/**
* Copy state between thread contexts in preparation for CPU handover.
*
* @note This method modifies the old thread contexts as well as the
* new thread context. The old thread context will have its quiesce
* event descheduled if it is scheduled and its status set to halted.
*
* @param new_tc Destination ThreadContext.
* @param old_tc Source ThreadContext.
*/
void takeOverFrom(ThreadContext &new_tc, ThreadContext &old_tc);
} // namespace gem5
#endif