pagetable_walker.hh revision 7901:f9b675da608a 
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
53class ThreadContext;
54
55namespace X86ISA
56{
57    class Walker : public MemObject
58    {
59      public:
60        enum State {
61            Ready,
62            Waiting,
63            // Long mode
64            LongPML4, LongPDP, LongPD, LongPTE,
65            // PAE legacy mode
66            PAEPDP, PAEPD, PAEPTE,
67            // Non PAE legacy mode with and without PSE
68            PSEPD, PD, PTE
69        };
70
71        // Act on the current state and determine what to do next. The global
72        // read should be the packet that just came back from a read and write
73        // should be NULL. When the function returns, read is either NULL
74        // if the machine is finished, or points to a packet to initiate
75        // the next read. If any write is required to update an "accessed"
76        // bit, write will point to a packet to do the write. Otherwise it
77        // will be NULL. The return value is whatever fault was incurred
78        // during this stage of the lookup.
79        Fault doNext(PacketPtr &write);
80
81        // Kick off the state machine.
82        Fault start(ThreadContext * _tc, BaseTLB::Translation *translation,
83                RequestPtr req, BaseTLB::Mode mode);
84        // Clean up after the state machine.
85        void
86        stop()
87        {
88            nextState = Ready;
89            delete read->req;
90            delete read;
91            read = NULL;
92        }
93
94      protected:
95
96        /*
97         * State having to do with sending packets.
98         */
99        PacketPtr read;
100        std::vector<PacketPtr> writes;
101
102        // How many memory operations are in flight.
103        unsigned inflight;
104
105        bool retrying;
106
107        /*
108         * The fault, if any, that's waiting to be delivered in timing mode.
109         */
110        Fault timingFault;
111
112        /*
113         * Functions for dealing with packets.
114         */
115        bool recvTiming(PacketPtr pkt);
116        void recvRetry();
117
118        void sendPackets();
119
120        /*
121         * Port for accessing memory
122         */
123        class WalkerPort : public Port
124        {
125          public:
126            WalkerPort(const std::string &_name, Walker * _walker) :
127                  Port(_name, _walker), walker(_walker),
128                  snoopRangeSent(false)
129            {}
130
131          protected:
132            Walker * walker;
133
134            bool snoopRangeSent;
135
136            bool recvTiming(PacketPtr pkt);
137            Tick recvAtomic(PacketPtr pkt);
138            void recvFunctional(PacketPtr pkt);
139            void recvStatusChange(Status status);
140            void recvRetry();
141            void getDeviceAddressRanges(AddrRangeList &resp,
142                    bool &snoop)
143            {
144                resp.clear();
145                snoop = true;
146            }
147        };
148
149        Port *getPort(const std::string &if_name, int idx = -1);
150
151        friend class WalkerPort;
152
153        WalkerPort port;
154
155        // The TLB we're supposed to load.
156        TLB * tlb;
157        System * sys;
158        BaseTLB::Translation * translation;
159
160        /*
161         * State machine state.
162         */
163        ThreadContext * tc;
164        RequestPtr req;
165        State state;
166        State nextState;
167        int size;
168        bool enableNX;
169        BaseTLB::Mode mode;
170        bool user;
171        TlbEntry entry;
172
173        Fault pageFault(bool present);
174
175      public:
176
177        void setTLB(TLB * _tlb)
178        {
179            tlb = _tlb;
180        }
181
182        typedef X86PagetableWalkerParams Params;
183
184        Walker(const Params *params) :
185            MemObject(params),
186            read(NULL), inflight(0), retrying(false),
187            port(name() + ".port", this),
188            tlb(NULL), sys(params->system),
189            tc(NULL), state(Ready), nextState(Ready)
190        {
191        }
192    };
193}
194#endif // __ARCH_X86_PAGE_TABLE_WALKER_HH__
195