xbar.hh revision 2982 
1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Ron Dreslinski
29 *          Ali Saidi
30 */
31
32/**
33 * @file
34 * Declaration of a bus object.
35 */
36
37#ifndef __MEM_BUS_HH__
38#define __MEM_BUS_HH__
39
40#include <string>
41#include <list>
42#include <inttypes.h>
43
44#include "base/range.hh"
45#include "mem/mem_object.hh"
46#include "mem/packet.hh"
47#include "mem/port.hh"
48#include "mem/request.hh"
49
50class Bus : public MemObject
51{
52    /** a globally unique id for this bus. */
53    int busId;
54
55    static const int defaultId = -1;
56
57    struct DevMap {
58        int portId;
59        Range<Addr> range;
60    };
61    std::vector<DevMap> portList;
62    AddrRangeList defaultRange;
63
64
65    /** Function called by the port when the bus is recieving a Timing
66      transaction.*/
67    bool recvTiming(Packet *pkt);
68
69    /** Function called by the port when the bus is recieving a Atomic
70      transaction.*/
71    Tick recvAtomic(Packet *pkt);
72
73    /** Function called by the port when the bus is recieving a Functional
74        transaction.*/
75    void recvFunctional(Packet *pkt);
76
77    /** Timing function called by port when it is once again able to process
78     * requests. */
79    void recvRetry(int id);
80
81    /** Function called by the port when the bus is recieving a status change.*/
82    void recvStatusChange(Port::Status status, int id);
83
84    /** Find which port connected to this bus (if any) should be given a packet
85     * with this address.
86     * @param addr Address to find port for.
87     * @param id Id of the port this packet was received from (to prevent
88     *             loops)
89     * @return pointer to port that the packet should be sent out of.
90     */
91    Port *findPort(Addr addr, int id);
92
93    /** Process address range request.
94     * @param resp addresses that we can respond to
95     * @param snoop addresses that we would like to snoop
96     * @param id ide of the busport that made the request.
97     */
98    void addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id);
99
100
101    /** Declaration of the buses port type, one will be instantiated for each
102        of the interfaces connecting to the bus. */
103    class BusPort : public Port
104    {
105        /** A pointer to the bus to which this port belongs. */
106        Bus *bus;
107
108        /** A id to keep track of the intercafe ID this port is connected to. */
109        int id;
110
111      public:
112
113        /** Constructor for the BusPort.*/
114        BusPort(const std::string &_name, Bus *_bus, int _id)
115            : Port(_name), bus(_bus), id(_id)
116        { }
117
118      protected:
119
120        /** When reciving a timing request from the peer port (at id),
121            pass it to the bus. */
122        virtual bool recvTiming(Packet *pkt)
123        { pkt->setSrc(id); return bus->recvTiming(pkt); }
124
125        /** When reciving a Atomic requestfrom the peer port (at id),
126            pass it to the bus. */
127        virtual Tick recvAtomic(Packet *pkt)
128        { pkt->setSrc(id); return bus->recvAtomic(pkt); }
129
130        /** When reciving a Functional requestfrom the peer port (at id),
131            pass it to the bus. */
132        virtual void recvFunctional(Packet *pkt)
133        { pkt->setSrc(id); bus->recvFunctional(pkt); }
134
135        /** When reciving a status changefrom the peer port (at id),
136            pass it to the bus. */
137        virtual void recvStatusChange(Status status)
138        { bus->recvStatusChange(status, id); }
139
140        /** When reciving a retry from the peer port (at id),
141            pass it to the bus. */
142        virtual void recvRetry()
143        { bus->recvRetry(id); }
144
145        // This should return all the 'owned' addresses that are
146        // downstream from this bus, yes?  That is, the union of all
147        // the 'owned' address ranges of all the other interfaces on
148        // this bus...
149        virtual void getDeviceAddressRanges(AddrRangeList &resp,
150                                            AddrRangeList &snoop)
151        { bus->addressRanges(resp, snoop, id); }
152
153        // Hack to make translating port work without changes
154        virtual int deviceBlockSize() { return 32; }
155
156    };
157
158    /** An array of pointers to the peer port interfaces
159        connected to this bus.*/
160    std::vector<Port*> interfaces;
161
162    /** An array of pointers to ports that retry should be called on because the
163     * original send failed for whatever reason.*/
164    std::list<Port*> retryList;
165
166    /** Port that handles requests that don't match any of the interfaces.*/
167    Port *defaultPort;
168
169  public:
170
171    /** A function used to return the port associated with this bus object. */
172    virtual Port *getPort(const std::string &if_name, int idx = -1);
173
174    virtual void init();
175
176    Bus(const std::string &n, int bus_id)
177        : MemObject(n), busId(bus_id), defaultPort(NULL)  {}
178
179};
180
181#endif //__MEM_BUS_HH__
182