pagetable_walker.hh revision 10654:e49bf4884c59 
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 * Authors: Gabe Black
38 */
39
40#ifndef __ARCH_X86_PAGE_TABLE_WALKER_HH__
41#define __ARCH_X86_PAGE_TABLE_WALKER_HH__
42
43#include <vector>
44
45#include "arch/x86/pagetable.hh"
46#include "arch/x86/tlb.hh"
47#include "base/types.hh"
48#include "mem/mem_object.hh"
49#include "mem/packet.hh"
50#include "params/X86PagetableWalker.hh"
51#include "sim/faults.hh"
52#include "sim/system.hh"
53
54class ThreadContext;
55
56namespace X86ISA
57{
58    class Walker : public MemObject
59    {
60      protected:
61        // Port for accessing memory
62        class WalkerPort : public MasterPort
63        {
64          public:
65            WalkerPort(const std::string &_name, Walker * _walker) :
66                  MasterPort(_name, _walker), walker(_walker)
67            {}
68
69          protected:
70            Walker *walker;
71
72            bool recvTimingResp(PacketPtr pkt);
73
74            /**
75             * Snooping a coherence request, do nothing.
76             */
77            void recvTimingSnoopReq(PacketPtr pkt) { }
78            Tick recvAtomicSnoop(PacketPtr pkt) { return 0; }
79            void recvFunctionalSnoop(PacketPtr pkt) { }
80            void recvRetry();
81            bool isSnooping() const { return true; }
82        };
83
84        friend class WalkerPort;
85        WalkerPort port;
86
87        // State to track each walk of the page table
88        class WalkerState
89        {
90          friend class Walker;
91          private:
92            enum State {
93                Ready,
94                Waiting,
95                // Long mode
96                LongPML4, LongPDP, LongPD, LongPTE,
97                // PAE legacy mode
98                PAEPDP, PAEPD, PAEPTE,
99                // Non PAE legacy mode with and without PSE
100                PSEPD, PD, PTE
101            };
102
103          protected:
104            Walker *walker;
105            ThreadContext *tc;
106            RequestPtr req;
107            State state;
108            State nextState;
109            int dataSize;
110            bool enableNX;
111            unsigned inflight;
112            TlbEntry entry;
113            PacketPtr read;
114            std::vector<PacketPtr> writes;
115            Fault timingFault;
116            TLB::Translation * translation;
117            BaseTLB::Mode mode;
118            bool functional;
119            bool timing;
120            bool retrying;
121            bool started;
122          public:
123            WalkerState(Walker * _walker, BaseTLB::Translation *_translation,
124                    RequestPtr _req, bool _isFunctional = false) :
125                        walker(_walker), req(_req), state(Ready),
126                        nextState(Ready), inflight(0),
127                        translation(_translation),
128                        functional(_isFunctional), timing(false),
129                        retrying(false), started(false)
130            {
131            }
132            void initState(ThreadContext * _tc, BaseTLB::Mode _mode,
133                           bool _isTiming = false);
134            Fault startWalk();
135            Fault startFunctional(Addr &addr, unsigned &logBytes);
136            bool recvPacket(PacketPtr pkt);
137            bool isRetrying();
138            bool wasStarted();
139            bool isTiming();
140            void retry();
141            std::string name() const {return walker->name();}
142
143          private:
144            void setupWalk(Addr vaddr);
145            Fault stepWalk(PacketPtr &write);
146            void sendPackets();
147            void endWalk();
148            Fault pageFault(bool present);
149        };
150
151        friend class WalkerState;
152        // State for timing and atomic accesses (need multiple per walker in
153        // the case of multiple outstanding requests in timing mode)
154        std::list<WalkerState *> currStates;
155        // State for functional accesses (only need one of these per walker)
156        WalkerState funcState;
157
158        struct WalkerSenderState : public Packet::SenderState
159        {
160            WalkerState * senderWalk;
161            WalkerSenderState(WalkerState * _senderWalk) :
162                senderWalk(_senderWalk) {}
163        };
164
165      public:
166        // Kick off the state machine.
167        Fault start(ThreadContext * _tc, BaseTLB::Translation *translation,
168                RequestPtr req, BaseTLB::Mode mode);
169        Fault startFunctional(ThreadContext * _tc, Addr &addr,
170                unsigned &logBytes, BaseTLB::Mode mode);
171        BaseMasterPort &getMasterPort(const std::string &if_name,
172                                      PortID idx = InvalidPortID);
173
174      protected:
175        // The TLB we're supposed to load.
176        TLB * tlb;
177        System * sys;
178        MasterID masterId;
179
180        // The number of outstanding walks that can be squashed per cycle.
181        unsigned numSquashable;
182
183        // Wrapper for checking for squashes before starting a translation.
184        void startWalkWrapper();
185
186        /**
187         * Event used to call startWalkWrapper.
188         **/
189        EventWrapper<Walker, &Walker::startWalkWrapper> startWalkWrapperEvent;
190
191        // Functions for dealing with packets.
192        bool recvTimingResp(PacketPtr pkt);
193        void recvRetry();
194        bool sendTiming(WalkerState * sendingState, PacketPtr pkt);
195
196      public:
197
198        void setTLB(TLB * _tlb)
199        {
200            tlb = _tlb;
201        }
202
203        typedef X86PagetableWalkerParams Params;
204
205        const Params *
206        params() const
207        {
208            return static_cast<const Params *>(_params);
209        }
210
211        Walker(const Params *params) :
212            MemObject(params), port(name() + ".port", this),
213            funcState(this, NULL, NULL, true), tlb(NULL), sys(params->system),
214            masterId(sys->getMasterId(name())),
215            numSquashable(params->num_squash_per_cycle),
216            startWalkWrapperEvent(this)
217        {
218        }
219    };
220}
221#endif // __ARCH_X86_PAGE_TABLE_WALKER_HH__
222