src/arch/x86/pagetable_walker.hh

   1 /*
   2  * Copyright (c) 2007 The Hewlett-Packard Development Company
   3  * All rights reserved.
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
  18  * redistributions in binary form must reproduce the above copyright
  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #ifndef __ARCH_X86_PAGE_TABLE_WALKER_HH__
  39 #define __ARCH_X86_PAGE_TABLE_WALKER_HH__
  40
  41 #include <vector>
  42
  43 #include "arch/x86/pagetable.hh"
  44 #include "arch/x86/tlb.hh"
  45 #include "base/types.hh"
  46 #include "mem/packet.hh"
  47 #include "params/X86PagetableWalker.hh"
  48 #include "sim/clocked_object.hh"
  49 #include "sim/faults.hh"
  50 #include "sim/system.hh"
  51
  52 class ThreadContext;
  53
  54 namespace X86ISA
  55 {
  56     class Walker : public ClockedObject
  57     {
  58       protected:
  59         // Port for accessing memory
  60         class WalkerPort : public RequestPort
  61         {
  62           public:
  63             WalkerPort(const std::string &_name, Walker * _walker) :
  64                   RequestPort(_name, _walker), walker(_walker)
  65             {}
  66
  67           protected:
  68             Walker *walker;
  69
  70             bool recvTimingResp(PacketPtr pkt);
  71             void recvReqRetry();
  72         };
  73
  74         friend class WalkerPort;
  75         WalkerPort port;
  76
  77         // State to track each walk of the page table
  78         class WalkerState
  79         {
  80           friend class Walker;
  81           private:
  82             enum State {
  83                 Ready,
  84                 Waiting,
  85                 // Long mode
  86                 LongPML4, LongPDP, LongPD, LongPTE,
  87                 // PAE legacy mode
  88                 PAEPDP, PAEPD, PAEPTE,
  89                 // Non PAE legacy mode with and without PSE
  90                 PSEPD, PD, PTE
  91             };
  92
  93           protected:
  94             Walker *walker;
  95             ThreadContext *tc;
  96             RequestPtr req;
  97             State state;
  98             State nextState;
  99             int dataSize;
 100             bool enableNX;
 101             unsigned inflight;
 102             TlbEntry entry;
 103             PacketPtr read;
 104             std::vector<PacketPtr> writes;
 105             Fault timingFault;
 106             TLB::Translation * translation;
 107             BaseTLB::Mode mode;
 108             bool functional;
 109             bool timing;
 110             bool retrying;
 111             bool started;
 112             bool squashed;
 113           public:
 114             WalkerState(Walker * _walker, BaseTLB::Translation *_translation,
 115                         const RequestPtr &_req, bool _isFunctional = false) :
 116                 walker(_walker), req(_req), state(Ready),
 117                 nextState(Ready), inflight(0),
 118                 translation(_translation),
 119                 functional(_isFunctional), timing(false),
 120                 retrying(false), started(false), squashed(false)
 121             {
 122             }
 123             void initState(ThreadContext * _tc, BaseTLB::Mode _mode,
 124                            bool _isTiming = false);
 125             Fault startWalk();
 126             Fault startFunctional(Addr &addr, unsigned &logBytes);
 127             bool recvPacket(PacketPtr pkt);
 128             unsigned numInflight() const;
 129             bool isRetrying();
 130             bool wasStarted();
 131             bool isTiming();
 132             void retry();
 133             void squash();
 134             std::string name() const {return walker->name();}
 135
 136           private:
 137             void setupWalk(Addr vaddr);
 138             Fault stepWalk(PacketPtr &write);
 139             void sendPackets();
 140             void endWalk();
 141             Fault pageFault(bool present);
 142         };
 143
 144         friend class WalkerState;
 145         // State for timing and atomic accesses (need multiple per walker in
 146         // the case of multiple outstanding requests in timing mode)
 147         std::list<WalkerState *> currStates;
 148         // State for functional accesses (only need one of these per walker)
 149         WalkerState funcState;
 150
 151         struct WalkerSenderState : public Packet::SenderState
 152         {
 153             WalkerState * senderWalk;
 154             WalkerSenderState(WalkerState * _senderWalk) :
 155                 senderWalk(_senderWalk) {}
 156         };
 157
 158       public:
 159         // Kick off the state machine.
 160         Fault start(ThreadContext * _tc, BaseTLB::Translation *translation,
 161                 const RequestPtr &req, BaseTLB::Mode mode);
 162         Fault startFunctional(ThreadContext * _tc, Addr &addr,
 163                 unsigned &logBytes, BaseTLB::Mode mode);
 164         Port &getPort(const std::string &if_name,
 165                       PortID idx=InvalidPortID) override;
 166
 167       protected:
 168         // The TLB we're supposed to load.
 169         TLB * tlb;
 170         System * sys;
 171         RequestorID requestorId;
 172
 173         // The number of outstanding walks that can be squashed per cycle.
 174         unsigned numSquashable;
 175
 176         // Wrapper for checking for squashes before starting a translation.
 177         void startWalkWrapper();
 178
 179         /**
 180          * Event used to call startWalkWrapper.
 181          **/
 182         EventFunctionWrapper startWalkWrapperEvent;
 183
 184         // Functions for dealing with packets.
 185         bool recvTimingResp(PacketPtr pkt);
 186         void recvReqRetry();
 187         bool sendTiming(WalkerState * sendingState, PacketPtr pkt);
 188
 189       public:
 190
 191         void setTLB(TLB * _tlb)
 192         {
 193             tlb = _tlb;
 194         }
 195
 196         typedef X86PagetableWalkerParams Params;
 197
 198         const Params *
 199         params() const
 200         {
 201             return static_cast<const Params *>(_params);
 202         }
 203
 204         Walker(const Params *params) :
 205             ClockedObject(params), port(name() + ".port", this),
 206             funcState(this, NULL, NULL, true), tlb(NULL), sys(params->system),
 207             requestorId(sys->getRequestorId(this)),
 208             numSquashable(params->num_squash_per_cycle),
 209             startWalkWrapperEvent([this]{ startWalkWrapper(); }, name())
 210         {
 211         }
 212     };
 213 }
 214 #endif // __ARCH_X86_PAGE_TABLE_WALKER_HH__