pagetable_walker.hh revision 7087:fb8d5786ff30 
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
52class ThreadContext;
53
54namespace X86ISA
55{
56    class Walker : public MemObject
57    {
58      public:
59        enum State {
60            Ready,
61            Waiting,
62            // Long mode
63            LongPML4, LongPDP, LongPD, LongPTE,
64            // PAE legacy mode
65            PAEPDP, PAEPD, PAEPTE,
66            // Non PAE legacy mode with and without PSE
67            PSEPD, PD, PTE
68        };
69
70        // Act on the current state and determine what to do next. The global
71        // read should be the packet that just came back from a read and write
72        // should be NULL. When the function returns, read is either NULL
73        // if the machine is finished, or points to a packet to initiate
74        // the next read. If any write is required to update an "accessed"
75        // bit, write will point to a packet to do the write. Otherwise it
76        // will be NULL. The return value is whatever fault was incurred
77        // during this stage of the lookup.
78        Fault doNext(PacketPtr &write);
79
80        // Kick off the state machine.
81        Fault start(ThreadContext * _tc, BaseTLB::Translation *translation,
82                RequestPtr req, BaseTLB::Mode mode);
83        // Clean up after the state machine.
84        void
85        stop()
86        {
87            nextState = Ready;
88            delete read->req;
89            delete read;
90            read = NULL;
91        }
92
93      protected:
94
95        /*
96         * State having to do with sending packets.
97         */
98        PacketPtr read;
99        std::vector<PacketPtr> writes;
100
101        // How many memory operations are in flight.
102        unsigned inflight;
103
104        bool retrying;
105
106        /*
107         * The fault, if any, that's waiting to be delivered in timing mode.
108         */
109        Fault timingFault;
110
111        /*
112         * Functions for dealing with packets.
113         */
114        bool recvTiming(PacketPtr pkt);
115        void recvRetry();
116
117        void sendPackets();
118
119        /*
120         * Port for accessing memory
121         */
122        class WalkerPort : public Port
123        {
124          public:
125            WalkerPort(const std::string &_name, Walker * _walker) :
126                  Port(_name, _walker), walker(_walker),
127                  snoopRangeSent(false)
128            {}
129
130          protected:
131            Walker * walker;
132
133            bool snoopRangeSent;
134
135            bool recvTiming(PacketPtr pkt);
136            Tick recvAtomic(PacketPtr pkt);
137            void recvFunctional(PacketPtr pkt);
138            void recvStatusChange(Status status);
139            void recvRetry();
140            void getDeviceAddressRanges(AddrRangeList &resp,
141                    bool &snoop)
142            {
143                resp.clear();
144                snoop = true;
145            }
146        };
147
148        Port *getPort(const std::string &if_name, int idx = -1);
149
150        friend class WalkerPort;
151
152        WalkerPort port;
153
154        // The TLB we're supposed to load.
155        TLB * tlb;
156        System * sys;
157        BaseTLB::Translation * translation;
158
159        /*
160         * State machine state.
161         */
162        ThreadContext * tc;
163        RequestPtr req;
164        State state;
165        State nextState;
166        int size;
167        bool enableNX;
168        BaseTLB::Mode mode;
169        bool user;
170        TlbEntry entry;
171
172        Fault pageFault(bool present);
173
174      public:
175
176        void setTLB(TLB * _tlb)
177        {
178            tlb = _tlb;
179        }
180
181        typedef X86PagetableWalkerParams Params;
182
183        Walker(const Params *params) :
184            MemObject(params),
185            read(NULL), inflight(0), retrying(false),
186            port(name() + ".port", this),
187            tlb(NULL), sys(params->system),
188            tc(NULL), state(Ready), nextState(Ready)
189        {
190        }
191    };
192}
193#endif // __ARCH_X86_PAGE_TABLE_WALKER_HH__
194