pagetable_walker.hh revision 12749 
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            void recvReqRetry();
74        };
75
76        friend class WalkerPort;
77        WalkerPort port;
78
79        // State to track each walk of the page table
80        class WalkerState
81        {
82          friend class Walker;
83          private:
84            enum State {
85                Ready,
86                Waiting,
87                // Long mode
88                LongPML4, LongPDP, LongPD, LongPTE,
89                // PAE legacy mode
90                PAEPDP, PAEPD, PAEPTE,
91                // Non PAE legacy mode with and without PSE
92                PSEPD, PD, PTE
93            };
94
95          protected:
96            Walker *walker;
97            ThreadContext *tc;
98            RequestPtr req;
99            State state;
100            State nextState;
101            int dataSize;
102            bool enableNX;
103            unsigned inflight;
104            TlbEntry entry;
105            PacketPtr read;
106            std::vector<PacketPtr> writes;
107            Fault timingFault;
108            TLB::Translation * translation;
109            BaseTLB::Mode mode;
110            bool functional;
111            bool timing;
112            bool retrying;
113            bool started;
114          public:
115            WalkerState(Walker * _walker, BaseTLB::Translation *_translation,
116                        const RequestPtr &_req, bool _isFunctional = false) :
117                walker(_walker), req(_req), state(Ready),
118                nextState(Ready), inflight(0),
119                translation(_translation),
120                functional(_isFunctional), timing(false),
121                retrying(false), started(false)
122            {
123            }
124            void initState(ThreadContext * _tc, BaseTLB::Mode _mode,
125                           bool _isTiming = false);
126            Fault startWalk();
127            Fault startFunctional(Addr &addr, unsigned &logBytes);
128            bool recvPacket(PacketPtr pkt);
129            bool isRetrying();
130            bool wasStarted();
131            bool isTiming();
132            void retry();
133            std::string name() const {return walker->name();}
134
135          private:
136            void setupWalk(Addr vaddr);
137            Fault stepWalk(PacketPtr &write);
138            void sendPackets();
139            void endWalk();
140            Fault pageFault(bool present);
141        };
142
143        friend class WalkerState;
144        // State for timing and atomic accesses (need multiple per walker in
145        // the case of multiple outstanding requests in timing mode)
146        std::list<WalkerState *> currStates;
147        // State for functional accesses (only need one of these per walker)
148        WalkerState funcState;
149
150        struct WalkerSenderState : public Packet::SenderState
151        {
152            WalkerState * senderWalk;
153            WalkerSenderState(WalkerState * _senderWalk) :
154                senderWalk(_senderWalk) {}
155        };
156
157      public:
158        // Kick off the state machine.
159        Fault start(ThreadContext * _tc, BaseTLB::Translation *translation,
160                const RequestPtr &req, BaseTLB::Mode mode);
161        Fault startFunctional(ThreadContext * _tc, Addr &addr,
162                unsigned &logBytes, BaseTLB::Mode mode);
163        BaseMasterPort &getMasterPort(const std::string &if_name,
164                                      PortID idx = InvalidPortID);
165
166      protected:
167        // The TLB we're supposed to load.
168        TLB * tlb;
169        System * sys;
170        MasterID masterId;
171
172        // The number of outstanding walks that can be squashed per cycle.
173        unsigned numSquashable;
174
175        // Wrapper for checking for squashes before starting a translation.
176        void startWalkWrapper();
177
178        /**
179         * Event used to call startWalkWrapper.
180         **/
181        EventFunctionWrapper startWalkWrapperEvent;
182
183        // Functions for dealing with packets.
184        bool recvTimingResp(PacketPtr pkt);
185        void recvReqRetry();
186        bool sendTiming(WalkerState * sendingState, PacketPtr pkt);
187
188      public:
189
190        void setTLB(TLB * _tlb)
191        {
192            tlb = _tlb;
193        }
194
195        typedef X86PagetableWalkerParams Params;
196
197        const Params *
198        params() const
199        {
200            return static_cast<const Params *>(_params);
201        }
202
203        Walker(const Params *params) :
204            MemObject(params), port(name() + ".port", this),
205            funcState(this, NULL, NULL, true), tlb(NULL), sys(params->system),
206            masterId(sys->getMasterId(this)),
207            numSquashable(params->num_squash_per_cycle),
208            startWalkWrapperEvent([this]{ startWalkWrapper(); }, name())
209        {
210        }
211    };
212}
213#endif // __ARCH_X86_PAGE_TABLE_WALKER_HH__
214