src/arch/arm/tlb.hh - public/gem5 - Git at Google

 /*
  * Copyright (c) 2010-2013, 2016, 2018 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) 2001-2005 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.
  *
  * Authors: Ali Saidi
  */

 #ifndef __ARCH_ARM_TLB_HH__
 #define __ARCH_ARM_TLB_HH__


 #include "arch/arm/isa_traits.hh"
 #include "arch/arm/pagetable.hh"
 #include "arch/arm/utility.hh"
 #include "arch/arm/vtophys.hh"
 #include "arch/generic/tlb.hh"
 #include "base/statistics.hh"
 #include "mem/request.hh"
 #include "params/ArmTLB.hh"
 #include "sim/probe/pmu.hh"

 class ThreadContext;

 namespace ArmISA {

 class TableWalker;
 class Stage2LookUp;
 class Stage2MMU;
 class TLB;

 class TlbTestInterface
 {
   public:
     TlbTestInterface() {}
     virtual ~TlbTestInterface() {}

     /**
      * Check if a TLB translation should be forced to fail.
      *
      * @param req Request requiring a translation.
      * @param is_priv Access from a privileged mode (i.e., not EL0)
      * @param mode Access type
      * @param domain Domain type
      */
     virtual Fault translationCheck(const RequestPtr &req, bool is_priv,
                                    BaseTLB::Mode mode,
                                    TlbEntry::DomainType domain) = 0;

     /**
      * Check if a page table walker access should be forced to fail.
      *
      * @param pa Physical address the walker is accessing
      * @param size Walker access size
      * @param va Virtual address that initiated the walk
      * @param is_secure Access from secure state
      * @param is_priv Access from a privileged mode (i.e., not EL0)
      * @param mode Access type
      * @param domain Domain type
      * @param lookup_level Page table walker level
      */
     virtual Fault walkCheck(Addr pa, Addr size, Addr va, bool is_secure,
                             Addr is_priv, BaseTLB::Mode mode,
                             TlbEntry::DomainType domain,
                             LookupLevel lookup_level) = 0;
 };

 class TLB : public BaseTLB
 {
   public:
     enum ArmFlags {
         AlignmentMask = 0x7,

         AlignByte = 0x0,
         AlignHalfWord = 0x1,
         AlignWord = 0x2,
         AlignDoubleWord = 0x3,
         AlignQuadWord = 0x4,
         AlignOctWord = 0x5,

         AllowUnaligned = 0x8,
         // Priv code operating as if it wasn't
         UserMode = 0x10,
         // Because zero otherwise looks like a valid setting and may be used
         // accidentally, this bit must be non-zero to show it was used on
         // purpose.
         MustBeOne = 0x40
     };

     enum ArmTranslationType {
         NormalTran = 0,
         S1CTran = 0x1,
         HypMode = 0x2,
         // Secure code operating as if it wasn't (required by some Address
         // Translate operations)
         S1S2NsTran = 0x4,
         // Address translation instructions (eg AT S1E0R_Xt) need to be handled
         // in special ways during translation because they could need to act
         // like a different EL than the current EL. The following flags are
         // for these instructions
         S1E0Tran = 0x8,
         S1E1Tran = 0x10,
         S1E2Tran = 0x20,
         S1E3Tran = 0x40,
         S12E0Tran = 0x80,
         S12E1Tran = 0x100
     };

     /**
      * Determine the EL to use for the purpose of a translation given
      * a specific translation type. If the translation type doesn't
      * specify an EL, we use the current EL.
      */
     static ExceptionLevel tranTypeEL(CPSR cpsr, ArmTranslationType type);

   protected:
     TlbEntry* table;     // the Page Table
     int size;            // TLB Size
     bool isStage2;       // Indicates this TLB is part of the second stage MMU
     bool stage2Req;      // Indicates whether a stage 2 lookup is also required
     // Indicates whether a stage 2 lookup of the table descriptors is required.
     // Certain address translation instructions will intercept the IPA but the
     // table descriptors still need to be translated by the stage2.
     bool stage2DescReq;
     uint64_t _attr;      // Memory attributes for last accessed TLB entry
     bool directToStage2; // Indicates whether all translation requests should
                          // be routed directly to the stage 2 TLB

     TableWalker *tableWalker;
     TLB *stage2Tlb;
     Stage2MMU *stage2Mmu;

     TlbTestInterface *test;

     // Access Stats
     mutable Stats::Scalar instHits;
     mutable Stats::Scalar instMisses;
     mutable Stats::Scalar readHits;
     mutable Stats::Scalar readMisses;
     mutable Stats::Scalar writeHits;
     mutable Stats::Scalar writeMisses;
     mutable Stats::Scalar inserts;
     mutable Stats::Scalar flushTlb;
     mutable Stats::Scalar flushTlbMva;
     mutable Stats::Scalar flushTlbMvaAsid;
     mutable Stats::Scalar flushTlbAsid;
     mutable Stats::Scalar flushedEntries;
     mutable Stats::Scalar alignFaults;
     mutable Stats::Scalar prefetchFaults;
     mutable Stats::Scalar domainFaults;
     mutable Stats::Scalar permsFaults;

     Stats::Formula readAccesses;
     Stats::Formula writeAccesses;
     Stats::Formula instAccesses;
     Stats::Formula hits;
     Stats::Formula misses;
     Stats::Formula accesses;

     /** PMU probe for TLB refills */
     ProbePoints::PMUUPtr ppRefills;

     int rangeMRU; //On lookup, only move entries ahead when outside rangeMRU

   public:
     TLB(const ArmTLBParams *p);
     TLB(const Params *p, int _size, TableWalker *_walker);

     /** Lookup an entry in the TLB
      * @param vpn virtual address
      * @param asn context id/address space id to use
      * @param vmid The virtual machine ID used for stage 2 translation
      * @param secure if the lookup is secure
      * @param hyp if the lookup is done from hyp mode
      * @param functional if the lookup should modify state
      * @param ignore_asn if on lookup asn should be ignored
      * @return pointer to TLB entry if it exists
      */
     TlbEntry *lookup(Addr vpn, uint16_t asn, uint8_t vmid, bool hyp,
                      bool secure, bool functional,
                      bool ignore_asn, uint8_t target_el);

     virtual ~TLB();

     void takeOverFrom(BaseTLB *otlb) override;

     /// setup all the back pointers
     void init() override;

     void setTestInterface(SimObject *ti);

     TableWalker *getTableWalker() { return tableWalker; }

     void setMMU(Stage2MMU *m, MasterID master_id);

     int getsize() const { return size; }

     void insert(Addr vaddr, TlbEntry &pte);

     Fault getTE(TlbEntry **te, const RequestPtr &req,
                 ThreadContext *tc, Mode mode,
                 Translation *translation, bool timing, bool functional,
                 bool is_secure, ArmTranslationType tranType);

     Fault getResultTe(TlbEntry **te, const RequestPtr &req,
                       ThreadContext *tc, Mode mode,
                       Translation *translation, bool timing,
                       bool functional, TlbEntry *mergeTe);

     Fault checkPermissions(TlbEntry *te, const RequestPtr &req, Mode mode);
     Fault checkPermissions64(TlbEntry *te, const RequestPtr &req, Mode mode,
                              ThreadContext *tc);


     /** Reset the entire TLB
      * @param secure_lookup if the operation affects the secure world
      */
     void flushAllSecurity(bool secure_lookup, uint8_t target_el,
                           bool ignore_el = false);

     /** Remove all entries in the non secure world, depending on whether they
      *  were allocated in hyp mode or not
      * @param hyp if the opperation affects hyp mode
      */
     void flushAllNs(bool hyp, uint8_t target_el, bool ignore_el = false);


     /** Reset the entire TLB. Used for CPU switching to prevent stale
      * translations after multiple switches
      */
     void flushAll() override
     {
         flushAllSecurity(false, 0, true);
         flushAllSecurity(true, 0, true);
     }

     /** Remove any entries that match both a va and asn
      * @param mva virtual address to flush
      * @param asn contextid/asn to flush on match
      * @param secure_lookup if the operation affects the secure world
      */
     void flushMvaAsid(Addr mva, uint64_t asn, bool secure_lookup,
                       uint8_t target_el);

     /** Remove any entries that match the asn
      * @param asn contextid/asn to flush on match
      * @param secure_lookup if the operation affects the secure world
      */
     void flushAsid(uint64_t asn, bool secure_lookup, uint8_t target_el);

     /** Remove all entries that match the va regardless of asn
      * @param mva address to flush from cache
      * @param secure_lookup if the operation affects the secure world
      * @param hyp if the operation affects hyp mode
      */
     void flushMva(Addr mva, bool secure_lookup, bool hyp, uint8_t target_el);

     /**
      * Invalidate all entries in the stage 2 TLB that match the given ipa
      * and the current VMID
      * @param ipa the address to invalidate
      * @param secure_lookup if the operation affects the secure world
      * @param hyp if the operation affects hyp mode
      */
     void flushIpaVmid(Addr ipa, bool secure_lookup, bool hyp, uint8_t target_el);

     Fault trickBoxCheck(const RequestPtr &req, Mode mode,
                         TlbEntry::DomainType domain);

     Fault walkTrickBoxCheck(Addr pa, bool is_secure, Addr va, Addr sz,
                             bool is_exec, bool is_write,
                             TlbEntry::DomainType domain,
                             LookupLevel lookup_level);

     void printTlb() const;

     void demapPage(Addr vaddr, uint64_t asn) override
     {
         // needed for x86 only
         panic("demapPage() is not implemented.\n");
     }

     /**
      * Do a functional lookup on the TLB (for debugging)
      * and don't modify any internal state
      * @param tc thread context to get the context id from
      * @param vaddr virtual address to translate
      * @param pa returned physical address
      * @return if the translation was successful
      */
     bool translateFunctional(ThreadContext *tc, Addr vaddr, Addr &paddr);

     /**
      * Do a functional lookup on the TLB (for checker cpu) that
      * behaves like a normal lookup without modifying any page table state.
      */
     Fault translateFunctional(const RequestPtr &req, ThreadContext *tc,
             Mode mode, ArmTranslationType tranType);
     Fault
     translateFunctional(const RequestPtr &req,
                         ThreadContext *tc, Mode mode) override
     {
         return translateFunctional(req, tc, mode, NormalTran);
     }

     /** Accessor functions for memory attributes for last accessed TLB entry
      */
     void
     setAttr(uint64_t attr)
     {
         _attr = attr;
     }

     uint64_t
     getAttr() const
     {
         return _attr;
     }

     Fault translateFs(const RequestPtr &req, ThreadContext *tc, Mode mode,
             Translation *translation, bool &delay,
             bool timing, ArmTranslationType tranType, bool functional = false);
     Fault translateSe(const RequestPtr &req, ThreadContext *tc, Mode mode,
             Translation *translation, bool &delay, bool timing);
     Fault translateAtomic(const RequestPtr &req, ThreadContext *tc, Mode mode,
             ArmTranslationType tranType);
     Fault
     translateAtomic(const RequestPtr &req,
                     ThreadContext *tc, Mode mode) override
     {
         return translateAtomic(req, tc, mode, NormalTran);
     }
     void translateTiming(
             const RequestPtr &req, ThreadContext *tc,
             Translation *translation, Mode mode,
             ArmTranslationType tranType);
     void
     translateTiming(const RequestPtr &req, ThreadContext *tc,
                     Translation *translation, Mode mode) override
     {
         translateTiming(req, tc, translation, mode, NormalTran);
     }
     Fault translateComplete(const RequestPtr &req, ThreadContext *tc,
             Translation *translation, Mode mode, ArmTranslationType tranType,
             bool callFromS2);
     Fault finalizePhysical(
             const RequestPtr &req,
             ThreadContext *tc, Mode mode) const override;

     void drainResume() override;

     // Checkpointing
     void serialize(CheckpointOut &cp) const override;
     void unserialize(CheckpointIn &cp) override;

     void regStats() override;

     void regProbePoints() override;

     /**
      * Get the table walker master port. This is used for migrating
      * port connections during a CPU takeOverFrom() call. For
      * architectures that do not have a table walker, NULL is
      * returned, hence the use of a pointer rather than a
      * reference. For ARM this method will always return a valid port
      * pointer.
      *
      * @return A pointer to the walker master port
      */
     BaseMasterPort* getMasterPort() override;

     // Caching misc register values here.
     // Writing to misc registers needs to invalidate them.
     // translateFunctional/translateSe/translateFs checks if they are
     // invalid and call updateMiscReg if necessary.
 protected:
     CPSR cpsr;
     bool aarch64;
     ExceptionLevel aarch64EL;
     SCTLR sctlr;
     SCR scr;
     bool isPriv;
     bool isSecure;
     bool isHyp;
     TTBCR ttbcr;
     uint16_t asid;
     uint8_t vmid;
     PRRR prrr;
     NMRR nmrr;
     HCR hcr;
     uint32_t dacr;
     bool miscRegValid;
     ContextID miscRegContext;
     ArmTranslationType curTranType;

     // Cached copies of system-level properties
     bool haveLPAE;
     bool haveVirtualization;
     bool haveLargeAsid64;

     AddrRange m5opRange;

     void updateMiscReg(ThreadContext *tc,
                        ArmTranslationType tranType = NormalTran);

 public:
     const Params *
     params() const
     {
         return dynamic_cast<const Params *>(_params);
     }
     inline void invalidateMiscReg() { miscRegValid = false; }

 private:
     /** Remove any entries that match both a va and asn
      * @param mva virtual address to flush
      * @param asn contextid/asn to flush on match
      * @param secure_lookup if the operation affects the secure world
      * @param hyp if the operation affects hyp mode
      * @param ignore_asn if the flush should ignore the asn
      */
     void _flushMva(Addr mva, uint64_t asn, bool secure_lookup,
                    bool hyp, bool ignore_asn, uint8_t target_el);

     bool checkELMatch(uint8_t target_el, uint8_t tentry_el, bool ignore_el);

   public: /* Testing */
     Fault testTranslation(const RequestPtr &req, Mode mode,
                           TlbEntry::DomainType domain);
     Fault testWalk(Addr pa, Addr size, Addr va, bool is_secure, Mode mode,
                    TlbEntry::DomainType domain,
                    LookupLevel lookup_level);
 };

 template<typename T>
 TLB *
 getITBPtr(T *tc)
 {
     auto tlb = static_cast<TLB *>(tc->getITBPtr());
     assert(tlb);
     return tlb;
 }

 template<typename T>
 TLB *
 getDTBPtr(T *tc)
 {
     auto tlb = static_cast<TLB *>(tc->getDTBPtr());
     assert(tlb);
     return tlb;
 }

 } // namespace ArmISA

 #endif // __ARCH_ARM_TLB_HH__
	/*
	* Copyright (c) 2010-2013, 2016, 2018 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) 2001-2005 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.
	*
	* Authors: Ali Saidi
	*/

	#ifndef __ARCH_ARM_TLB_HH__
	#define __ARCH_ARM_TLB_HH__


	#include "arch/arm/isa_traits.hh"
	#include "arch/arm/pagetable.hh"
	#include "arch/arm/utility.hh"
	#include "arch/arm/vtophys.hh"
	#include "arch/generic/tlb.hh"
	#include "base/statistics.hh"
	#include "mem/request.hh"
	#include "params/ArmTLB.hh"
	#include "sim/probe/pmu.hh"

	class ThreadContext;

	namespace ArmISA {

	class TableWalker;
	class Stage2LookUp;
	class Stage2MMU;
	class TLB;

	class TlbTestInterface
	{
	public:
	TlbTestInterface() {}
	virtual ~TlbTestInterface() {}

	/**
	* Check if a TLB translation should be forced to fail.
	*
	* @param req Request requiring a translation.
	* @param is_priv Access from a privileged mode (i.e., not EL0)
	* @param mode Access type
	* @param domain Domain type
	*/
	virtual Fault translationCheck(const RequestPtr &req, bool is_priv,
	BaseTLB::Mode mode,
	TlbEntry::DomainType domain) = 0;

	/**
	* Check if a page table walker access should be forced to fail.
	*
	* @param pa Physical address the walker is accessing
	* @param size Walker access size
	* @param va Virtual address that initiated the walk
	* @param is_secure Access from secure state
	* @param is_priv Access from a privileged mode (i.e., not EL0)
	* @param mode Access type
	* @param domain Domain type
	* @param lookup_level Page table walker level
	*/
	virtual Fault walkCheck(Addr pa, Addr size, Addr va, bool is_secure,
	Addr is_priv, BaseTLB::Mode mode,
	TlbEntry::DomainType domain,
	LookupLevel lookup_level) = 0;
	};

	class TLB : public BaseTLB
	{
	public:
	enum ArmFlags {
	AlignmentMask = 0x7,

	AlignByte = 0x0,
	AlignHalfWord = 0x1,
	AlignWord = 0x2,
	AlignDoubleWord = 0x3,
	AlignQuadWord = 0x4,
	AlignOctWord = 0x5,

	AllowUnaligned = 0x8,
	// Priv code operating as if it wasn't
	UserMode = 0x10,
	// Because zero otherwise looks like a valid setting and may be used
	// accidentally, this bit must be non-zero to show it was used on
	// purpose.
	MustBeOne = 0x40
	};

	enum ArmTranslationType {
	NormalTran = 0,
	S1CTran = 0x1,
	HypMode = 0x2,
	// Secure code operating as if it wasn't (required by some Address
	// Translate operations)
	S1S2NsTran = 0x4,
	// Address translation instructions (eg AT S1E0R_Xt) need to be handled
	// in special ways during translation because they could need to act
	// like a different EL than the current EL. The following flags are
	// for these instructions
	S1E0Tran = 0x8,
	S1E1Tran = 0x10,
	S1E2Tran = 0x20,
	S1E3Tran = 0x40,
	S12E0Tran = 0x80,
	S12E1Tran = 0x100
	};

	/**
	* Determine the EL to use for the purpose of a translation given
	* a specific translation type. If the translation type doesn't
	* specify an EL, we use the current EL.
	*/
	static ExceptionLevel tranTypeEL(CPSR cpsr, ArmTranslationType type);

	protected:
	TlbEntry* table; // the Page Table
	int size; // TLB Size
	bool isStage2; // Indicates this TLB is part of the second stage MMU
	bool stage2Req; // Indicates whether a stage 2 lookup is also required
	// Indicates whether a stage 2 lookup of the table descriptors is required.
	// Certain address translation instructions will intercept the IPA but the
	// table descriptors still need to be translated by the stage2.
	bool stage2DescReq;
	uint64_t _attr; // Memory attributes for last accessed TLB entry
	bool directToStage2; // Indicates whether all translation requests should
	// be routed directly to the stage 2 TLB

	TableWalker *tableWalker;
	TLB *stage2Tlb;
	Stage2MMU *stage2Mmu;

	TlbTestInterface *test;

	// Access Stats
	mutable Stats::Scalar instHits;
	mutable Stats::Scalar instMisses;
	mutable Stats::Scalar readHits;
	mutable Stats::Scalar readMisses;
	mutable Stats::Scalar writeHits;
	mutable Stats::Scalar writeMisses;
	mutable Stats::Scalar inserts;
	mutable Stats::Scalar flushTlb;
	mutable Stats::Scalar flushTlbMva;
	mutable Stats::Scalar flushTlbMvaAsid;
	mutable Stats::Scalar flushTlbAsid;
	mutable Stats::Scalar flushedEntries;
	mutable Stats::Scalar alignFaults;
	mutable Stats::Scalar prefetchFaults;
	mutable Stats::Scalar domainFaults;
	mutable Stats::Scalar permsFaults;

	Stats::Formula readAccesses;
	Stats::Formula writeAccesses;
	Stats::Formula instAccesses;
	Stats::Formula hits;
	Stats::Formula misses;
	Stats::Formula accesses;

	/** PMU probe for TLB refills */
	ProbePoints::PMUUPtr ppRefills;

	int rangeMRU; //On lookup, only move entries ahead when outside rangeMRU

	public:
	TLB(const ArmTLBParams *p);
	TLB(const Params p, int _size, TableWalker _walker);

	/** Lookup an entry in the TLB
	* @param vpn virtual address
	* @param asn context id/address space id to use
	* @param vmid The virtual machine ID used for stage 2 translation
	* @param secure if the lookup is secure
	* @param hyp if the lookup is done from hyp mode
	* @param functional if the lookup should modify state
	* @param ignore_asn if on lookup asn should be ignored
	* @return pointer to TLB entry if it exists
	*/
	TlbEntry *lookup(Addr vpn, uint16_t asn, uint8_t vmid, bool hyp,
	bool secure, bool functional,
	bool ignore_asn, uint8_t target_el);

	virtual ~TLB();

	void takeOverFrom(BaseTLB *otlb) override;

	/// setup all the back pointers
	void init() override;

	void setTestInterface(SimObject *ti);

	TableWalker *getTableWalker() { return tableWalker; }

	void setMMU(Stage2MMU *m, MasterID master_id);

	int getsize() const { return size; }

	void insert(Addr vaddr, TlbEntry &pte);

	Fault getTE(TlbEntry **te, const RequestPtr &req,
	ThreadContext *tc, Mode mode,
	Translation *translation, bool timing, bool functional,
	bool is_secure, ArmTranslationType tranType);

	Fault getResultTe(TlbEntry **te, const RequestPtr &req,
	ThreadContext *tc, Mode mode,
	Translation *translation, bool timing,
	bool functional, TlbEntry *mergeTe);

	Fault checkPermissions(TlbEntry *te, const RequestPtr &req, Mode mode);
	Fault checkPermissions64(TlbEntry *te, const RequestPtr &req, Mode mode,
	ThreadContext *tc);


	/** Reset the entire TLB
	* @param secure_lookup if the operation affects the secure world
	*/
	void flushAllSecurity(bool secure_lookup, uint8_t target_el,
	bool ignore_el = false);

	/** Remove all entries in the non secure world, depending on whether they
	* were allocated in hyp mode or not
	* @param hyp if the opperation affects hyp mode
	*/
	void flushAllNs(bool hyp, uint8_t target_el, bool ignore_el = false);


	/** Reset the entire TLB. Used for CPU switching to prevent stale
	* translations after multiple switches
	*/
	void flushAll() override
	{
	flushAllSecurity(false, 0, true);
	flushAllSecurity(true, 0, true);
	}

	/** Remove any entries that match both a va and asn
	* @param mva virtual address to flush
	* @param asn contextid/asn to flush on match
	* @param secure_lookup if the operation affects the secure world
	*/
	void flushMvaAsid(Addr mva, uint64_t asn, bool secure_lookup,
	uint8_t target_el);

	/** Remove any entries that match the asn
	* @param asn contextid/asn to flush on match
	* @param secure_lookup if the operation affects the secure world
	*/
	void flushAsid(uint64_t asn, bool secure_lookup, uint8_t target_el);

	/** Remove all entries that match the va regardless of asn
	* @param mva address to flush from cache
	* @param secure_lookup if the operation affects the secure world
	* @param hyp if the operation affects hyp mode
	*/
	void flushMva(Addr mva, bool secure_lookup, bool hyp, uint8_t target_el);

	/**
	* Invalidate all entries in the stage 2 TLB that match the given ipa
	* and the current VMID
	* @param ipa the address to invalidate
	* @param secure_lookup if the operation affects the secure world
	* @param hyp if the operation affects hyp mode
	*/
	void flushIpaVmid(Addr ipa, bool secure_lookup, bool hyp, uint8_t target_el);

	Fault trickBoxCheck(const RequestPtr &req, Mode mode,
	TlbEntry::DomainType domain);

	Fault walkTrickBoxCheck(Addr pa, bool is_secure, Addr va, Addr sz,
	bool is_exec, bool is_write,
	TlbEntry::DomainType domain,
	LookupLevel lookup_level);

	void printTlb() const;

	void demapPage(Addr vaddr, uint64_t asn) override
	{
	// needed for x86 only
	panic("demapPage() is not implemented.\n");
	}

	/**
	* Do a functional lookup on the TLB (for debugging)
	* and don't modify any internal state
	* @param tc thread context to get the context id from
	* @param vaddr virtual address to translate
	* @param pa returned physical address
	* @return if the translation was successful
	*/
	bool translateFunctional(ThreadContext *tc, Addr vaddr, Addr &paddr);

	/**
	* Do a functional lookup on the TLB (for checker cpu) that
	* behaves like a normal lookup without modifying any page table state.
	*/
	Fault translateFunctional(const RequestPtr &req, ThreadContext *tc,
	Mode mode, ArmTranslationType tranType);
	Fault
	translateFunctional(const RequestPtr &req,
	ThreadContext *tc, Mode mode) override
	{
	return translateFunctional(req, tc, mode, NormalTran);
	}

	/** Accessor functions for memory attributes for last accessed TLB entry
	*/
	void
	setAttr(uint64_t attr)
	{
	_attr = attr;
	}

	uint64_t
	getAttr() const
	{
	return _attr;
	}

	Fault translateFs(const RequestPtr &req, ThreadContext *tc, Mode mode,
	Translation *translation, bool &delay,
	bool timing, ArmTranslationType tranType, bool functional = false);
	Fault translateSe(const RequestPtr &req, ThreadContext *tc, Mode mode,
	Translation *translation, bool &delay, bool timing);
	Fault translateAtomic(const RequestPtr &req, ThreadContext *tc, Mode mode,
	ArmTranslationType tranType);
	Fault
	translateAtomic(const RequestPtr &req,
	ThreadContext *tc, Mode mode) override
	{
	return translateAtomic(req, tc, mode, NormalTran);
	}
	void translateTiming(
	const RequestPtr &req, ThreadContext *tc,
	Translation *translation, Mode mode,
	ArmTranslationType tranType);
	void
	translateTiming(const RequestPtr &req, ThreadContext *tc,
	Translation *translation, Mode mode) override
	{
	translateTiming(req, tc, translation, mode, NormalTran);
	}
	Fault translateComplete(const RequestPtr &req, ThreadContext *tc,
	Translation *translation, Mode mode, ArmTranslationType tranType,
	bool callFromS2);
	Fault finalizePhysical(
	const RequestPtr &req,
	ThreadContext *tc, Mode mode) const override;

	void drainResume() override;

	// Checkpointing
	void serialize(CheckpointOut &cp) const override;
	void unserialize(CheckpointIn &cp) override;

	void regStats() override;

	void regProbePoints() override;

	/**
	* Get the table walker master port. This is used for migrating
	* port connections during a CPU takeOverFrom() call. For
	* architectures that do not have a table walker, NULL is
	* returned, hence the use of a pointer rather than a
	* reference. For ARM this method will always return a valid port
	* pointer.
	*
	* @return A pointer to the walker master port
	*/
	BaseMasterPort* getMasterPort() override;

	// Caching misc register values here.
	// Writing to misc registers needs to invalidate them.
	// translateFunctional/translateSe/translateFs checks if they are
	// invalid and call updateMiscReg if necessary.
	protected:
	CPSR cpsr;
	bool aarch64;
	ExceptionLevel aarch64EL;
	SCTLR sctlr;
	SCR scr;
	bool isPriv;
	bool isSecure;
	bool isHyp;
	TTBCR ttbcr;
	uint16_t asid;
	uint8_t vmid;
	PRRR prrr;
	NMRR nmrr;
	HCR hcr;
	uint32_t dacr;
	bool miscRegValid;
	ContextID miscRegContext;
	ArmTranslationType curTranType;

	// Cached copies of system-level properties
	bool haveLPAE;
	bool haveVirtualization;
	bool haveLargeAsid64;

	AddrRange m5opRange;

	void updateMiscReg(ThreadContext *tc,
	ArmTranslationType tranType = NormalTran);

	public:
	const Params *
	params() const
	{
	return dynamic_cast<const Params *>(_params);
	}
	inline void invalidateMiscReg() { miscRegValid = false; }

	private:
	/** Remove any entries that match both a va and asn
	* @param mva virtual address to flush
	* @param asn contextid/asn to flush on match
	* @param secure_lookup if the operation affects the secure world
	* @param hyp if the operation affects hyp mode
	* @param ignore_asn if the flush should ignore the asn
	*/
	void _flushMva(Addr mva, uint64_t asn, bool secure_lookup,
	bool hyp, bool ignore_asn, uint8_t target_el);

	bool checkELMatch(uint8_t target_el, uint8_t tentry_el, bool ignore_el);

	public: /* Testing */
	Fault testTranslation(const RequestPtr &req, Mode mode,
	TlbEntry::DomainType domain);
	Fault testWalk(Addr pa, Addr size, Addr va, bool is_secure, Mode mode,
	TlbEntry::DomainType domain,
	LookupLevel lookup_level);
	};

	template<typename T>
	TLB *
	getITBPtr(T *tc)
	{
	auto tlb = static_cast<TLB *>(tc->getITBPtr());
	assert(tlb);
	return tlb;
	}

	template<typename T>
	TLB *
	getDTBPtr(T *tc)
	{
	auto tlb = static_cast<TLB *>(tc->getDTBPtr());
	assert(tlb);
	return tlb;
	}

	} // namespace ArmISA

	#endif // __ARCH_ARM_TLB_HH__