src/arch/x86/pagetable.hh - arm/gem5 - Git at Google

 /*
  * Copyright (c) 2014 Advanced Micro Devices, Inc.
  * Copyright (c) 2007 The Hewlett-Packard Development Company
  * 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.
  *
  * 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: Gabe Black
  */

 #ifndef __ARCH_X86_PAGETABLE_HH__
 #define __ARCH_X86_PAGETABLE_HH__

 #include <iostream>
 #include <string>
 #include <vector>

 #include "base/bitunion.hh"
 #include "base/types.hh"
 #include "base/trie.hh"
 #include "arch/x86/system.hh"
 #include "debug/MMU.hh"

 class Checkpoint;
 class ThreadContext;

 namespace X86ISA
 {
     struct TlbEntry;
 }

 typedef Trie<Addr, X86ISA::TlbEntry> TlbEntryTrie;

 namespace X86ISA
 {
     BitUnion64(VAddr)
         Bitfield<20, 12> longl1;
         Bitfield<29, 21> longl2;
         Bitfield<38, 30> longl3;
         Bitfield<47, 39> longl4;

         Bitfield<20, 12> pael1;
         Bitfield<29, 21> pael2;
         Bitfield<31, 30> pael3;

         Bitfield<21, 12> norml1;
         Bitfield<31, 22> norml2;
     EndBitUnion(VAddr)

     // Unfortunately, the placement of the base field in a page table entry is
     // very erratic and would make a mess here. It might be moved here at some
     // point in the future.
     BitUnion64(PageTableEntry)
         Bitfield<63> nx;
         Bitfield<51, 12> base;
         Bitfield<11, 9> avl;
         Bitfield<8> g;
         Bitfield<7> ps;
         Bitfield<6> d;
         Bitfield<5> a;
         Bitfield<4> pcd;
         Bitfield<3> pwt;
         Bitfield<2> u;
         Bitfield<1> w;
         Bitfield<0> p;
     EndBitUnion(PageTableEntry)


     struct TlbEntry : public Serializable
     {
         // The base of the physical page.
         Addr paddr;

         // The beginning of the virtual page this entry maps.
         Addr vaddr;
         // The size of the page this represents, in address bits.
         unsigned logBytes;

         // Read permission is always available, assuming it isn't blocked by
         // other mechanisms.
         bool writable;
         // Whether this page is accesible without being in supervisor mode.
         bool user;
         // Whether to use write through or write back. M5 ignores this and
         // lets the caches handle the writeback policy.
         //bool pwt;
         // Whether the page is cacheable or not.
         bool uncacheable;
         // Whether or not to kick this page out on a write to CR3.
         bool global;
         // A bit used to form an index into the PAT table.
         bool patBit;
         // Whether or not memory on this page can be executed.
         bool noExec;
         // A sequence number to keep track of LRU.
         uint64_t lruSeq;

         TlbEntryTrie::Handle trieHandle;

         TlbEntry(Addr asn, Addr _vaddr, Addr _paddr,
                  bool uncacheable, bool read_only);
         TlbEntry();

         void
         updateVaddr(Addr new_vaddr)
         {
             vaddr = new_vaddr;
         }

         Addr pageStart()
         {
             return paddr;
         }

         // Return the page size in bytes
         int size()
         {
             return (1 << logBytes);
         }

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

     /** The size of each level of the page table expressed in base 2
      * logarithmic values
      */
     const std::vector<uint8_t> PageTableLayout = {9, 9, 9, 9};

     /* x86 specific PTE flags */
     enum PTEField{
         PTE_NotPresent  = 1,
         PTE_Supervisor  = 2,
         PTE_ReadOnly    = 4,
         PTE_Uncacheable = 8,
     };

     /** Page table operations specific to x86 ISA.
      * Indended to be used as parameter of MultiLevelPageTable.
      */
     class PageTableOps
     {
       public:
         void setPTEFields(PageTableEntry& PTE, uint64_t flags = 0)
         {
             PTE.p   = flags & PTE_NotPresent  ? 0 : 1;
             PTE.pcd = flags & PTE_Uncacheable ? 1 : 0;
             PTE.w   = flags & PTE_ReadOnly    ? 0 : 1;
             PTE.u   = flags & PTE_Supervisor  ? 0 : 1;
         }

         /** returns the page number out of a page table entry */
         Addr getPnum(PageTableEntry PTE)
         {
             return PTE.base;
         }

         bool isUncacheable(const PageTableEntry PTE)
         {
             return PTE.pcd;
         }

         bool isReadOnly(PageTableEntry PTE)
         {
             return !PTE.w;
         }

         /** sets the page number in a page table entry */
         void setPnum(PageTableEntry& PTE, Addr paddr)
         {
             PTE.base = paddr;
         }

         /** returns the offsets to index in every level of a page
          * table, contained in a virtual address
          */
         std::vector<uint64_t> getOffsets(Addr vaddr)
         {
             X86ISA::VAddr addr(vaddr);
             return {addr.longl1, addr.longl2, addr.longl3, addr.longl4};
         }
     };

 }

 #endif
	/*
	* Copyright (c) 2014 Advanced Micro Devices, Inc.
	* Copyright (c) 2007 The Hewlett-Packard Development Company
	* 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.
	*
	* 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: Gabe Black
	*/

	#ifndef __ARCH_X86_PAGETABLE_HH__
	#define __ARCH_X86_PAGETABLE_HH__

	#include <iostream>
	#include <string>
	#include <vector>

	#include "base/bitunion.hh"
	#include "base/types.hh"
	#include "base/trie.hh"
	#include "arch/x86/system.hh"
	#include "debug/MMU.hh"

	class Checkpoint;
	class ThreadContext;

	namespace X86ISA
	{
	struct TlbEntry;
	}

	typedef Trie<Addr, X86ISA::TlbEntry> TlbEntryTrie;

	namespace X86ISA
	{
	BitUnion64(VAddr)
	Bitfield<20, 12> longl1;
	Bitfield<29, 21> longl2;
	Bitfield<38, 30> longl3;
	Bitfield<47, 39> longl4;

	Bitfield<20, 12> pael1;
	Bitfield<29, 21> pael2;
	Bitfield<31, 30> pael3;

	Bitfield<21, 12> norml1;
	Bitfield<31, 22> norml2;
	EndBitUnion(VAddr)

	// Unfortunately, the placement of the base field in a page table entry is
	// very erratic and would make a mess here. It might be moved here at some
	// point in the future.
	BitUnion64(PageTableEntry)
	Bitfield<63> nx;
	Bitfield<51, 12> base;
	Bitfield<11, 9> avl;
	Bitfield<8> g;
	Bitfield<7> ps;
	Bitfield<6> d;
	Bitfield<5> a;
	Bitfield<4> pcd;
	Bitfield<3> pwt;
	Bitfield<2> u;
	Bitfield<1> w;
	Bitfield<0> p;
	EndBitUnion(PageTableEntry)


	struct TlbEntry : public Serializable
	{
	// The base of the physical page.
	Addr paddr;

	// The beginning of the virtual page this entry maps.
	Addr vaddr;
	// The size of the page this represents, in address bits.
	unsigned logBytes;

	// Read permission is always available, assuming it isn't blocked by
	// other mechanisms.
	bool writable;
	// Whether this page is accesible without being in supervisor mode.
	bool user;
	// Whether to use write through or write back. M5 ignores this and
	// lets the caches handle the writeback policy.
	//bool pwt;
	// Whether the page is cacheable or not.
	bool uncacheable;
	// Whether or not to kick this page out on a write to CR3.
	bool global;
	// A bit used to form an index into the PAT table.
	bool patBit;
	// Whether or not memory on this page can be executed.
	bool noExec;
	// A sequence number to keep track of LRU.
	uint64_t lruSeq;

	TlbEntryTrie::Handle trieHandle;

	TlbEntry(Addr asn, Addr _vaddr, Addr _paddr,
	bool uncacheable, bool read_only);
	TlbEntry();

	void
	updateVaddr(Addr new_vaddr)
	{
	vaddr = new_vaddr;
	}

	Addr pageStart()
	{
	return paddr;
	}

	// Return the page size in bytes
	int size()
	{
	return (1 << logBytes);
	}

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

	/** The size of each level of the page table expressed in base 2
	* logarithmic values
	*/
	const std::vector<uint8_t> PageTableLayout = {9, 9, 9, 9};

	/* x86 specific PTE flags */
	enum PTEField{
	PTE_NotPresent = 1,
	PTE_Supervisor = 2,
	PTE_ReadOnly = 4,
	PTE_Uncacheable = 8,
	};

	/** Page table operations specific to x86 ISA.
	* Indended to be used as parameter of MultiLevelPageTable.
	*/
	class PageTableOps
	{
	public:
	void setPTEFields(PageTableEntry& PTE, uint64_t flags = 0)
	{
	PTE.p = flags & PTE_NotPresent ? 0 : 1;
	PTE.pcd = flags & PTE_Uncacheable ? 1 : 0;
	PTE.w = flags & PTE_ReadOnly ? 0 : 1;
	PTE.u = flags & PTE_Supervisor ? 0 : 1;
	}

	/** returns the page number out of a page table entry */
	Addr getPnum(PageTableEntry PTE)
	{
	return PTE.base;
	}

	bool isUncacheable(const PageTableEntry PTE)
	{
	return PTE.pcd;
	}

	bool isReadOnly(PageTableEntry PTE)
	{
	return !PTE.w;
	}

	/** sets the page number in a page table entry */
	void setPnum(PageTableEntry& PTE, Addr paddr)
	{
	PTE.base = paddr;
	}

	/** returns the offsets to index in every level of a page
	* table, contained in a virtual address
	*/
	std::vector<uint64_t> getOffsets(Addr vaddr)
	{
	X86ISA::VAddr addr(vaddr);
	return {addr.longl1, addr.longl2, addr.longl3, addr.longl4};
	}
	};

	}

	#endif